摘要:

Royal Society of Chemistry Analytical Division Atomic Spectroscopy Group Eighth Biennial National Atomic Spectroscopy Symposium 8th BNASS University of East Anglia UK 17-20 July 1996 Plenary Lectunrs Invited Lecturers Call for Papers social Programme Workshop Further Details Dr S J Hill Professor N Furuta Professor F Adam Professor J M Mermet and Professor G Hieftje Dr 0 Donard. Dr S J Parry. Dr S Fainveather-Tait Dr A Ellis Dr A G Howard. Dr J Brenner. Dr J Marshall Dr N J Miller-lhli. Dr S Tanner and Professor D Littlejohn Contributed oral and poster presentations on recent developments in both pure and applied atomic spectroscopy - analytical applications theoretical studies or fundamental advances in AAS AES AFS. inorganic MS and XRF. Three copies of abstracts must be submitted before 28 February 1996.BNASS has an enviable reputation of being a friendly and dynamic meeting. A number of social events including a Symposium Dinner will form an integral part of the meeting. Immediately prior to the 8th BNASS there will be a Short Course on Sample Pre-treatment and Sample Introduction for Atomic Spectroscopy 17 July a.m. 1996. Ms Brenda Holliday. Royal Society of Chemistry Thomas Graham House. Science Park Milton Road Cambridge. CB4 4WF UK. Tel +44 (0)1223 420066; Fax +44 (0)1223 420247; E-mail JAAS @ RSC.ORGCONFERENCE ANNOUNCEMENT 1995 FIRST MEDITERRANEAN BASIN CONFERENCE ON ANALYTICAL CHEMISTRY Cordoba Spain 5-10 November 1995 In order to promote collaboration among analytical scientists of the whole Mediterranean Basin the 1995 First Mediterranean Basin Conference on Analytical Chemistry will provide an adequate forum for reporting and thoroughly discussing the latest research results in basic and instrumental developments in Analytical Chemistry.Other aims of this Conference are - To promote new opportunities for young scientists in the Mediterranean Sea area (particularly for those in the Southern Bank) to attend international meetings in countries of the region to attend training workshops on new analytical techniques to attend short courses on new techniques and trends in Analytical Chemistry and to establish new links for research in/or other countries of the region. - To stimulate the progress of Analytical Chemistry as a whole by solving analytical problems affecting the Mediterranean Area.The program has been designed to attract participants from industry universities and research centers. The program will comprise invited plenary and key-note lecturers contributed oral papers and posters distributed in several Symposia covering the following topics Education of Analytical Chemistry Environmental Analytical Chemistry Agriculture and Food Analysis Geoanalytical Chemistry and Benefitiation of Minerals Biomedical Analysis Archeometry and Art Objects Preservation Quality Assurance and Harmonization of Procedures. A few Short COU~S~S Special Sessions on "hot" topics and an Exhibition of Instrumentation has also been arranged. Invited lecturers who have already confirmed their contribution include M. Valc&rcel I.B. Brenner D. Barcelo S. Caroli A. Laachach. O.X.F. Donnard M. M. Khater H. Muntau J. Albaiges B.Y. Mekla'ti P. Quevauviller etc. CALL FOR PAPERS Titles of submitted oral or poster presentations are solicited with the preliminq registration card by 30 May 1995. Submission of final Conference Abstracts are requested not later than 30 June 1995. SOCIAL ACTMTIES Varied social activities including a visit to Granada are being planned. FURTHER INFORMATION For further information and pre-registration forms please contact Prof. Alfred0 Sanz-Medel (Chairman) Department of Physical and Analytical Chemistry Faculty of Chemistry University of Oviedo C/ Julian Claveria s/n 33006ovied0 SPAIN Phone 3 4 - 8 - 5 1 0 3 4 8 0 o 3 4 - 8 - 5 1 0 3 4 7 4 FAX 3 4 - 8 - 5 103125

ISSN:0267-9477    

DOI:10.1039/JA99510BP016

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Journal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates) JAAS Editorial Board Chairman B. L. Sharp (Loughborough UK) A. T. Ellis (Abingdon UK) J. M. Gordon (Cambridge UK) S. J. Haswell (Hull UK) S. J. Hill (Plymouth UK) R. C. Hutton (Winsford UK) D. Littlejohn (Glasgow UK) J. Marshall (Middlesbrough UK) A. Sanz-Medel (Oviedo Spain) P. D. P. Taylor (Geel Belgium) JAAS Advisory Board F. C. Adams (Antwerp Belgium) R. M. Barnes (Amherst MA USA) L. Bezur (Budapest Hungary) M. W. Blades (Vancouver Canada) R. F. Browner (Atlanta GA USA) J. L. Burguera (Merida Venezuela) S. Caroli (Rome Italy) J. A. Caruso (Cincinnati OH USA) H. M. Crews (Norwich UK) A. J. Curtius (Florianopolis Brazil) J. B. Dawson (Leeds UK) 0. F. X. Donard (Talence France) M. T. C. de Loos-Vollebregt (Delft The Netherlands) L.Ebdon (Plymouth UK) M. S. Epstein (Gaithersburg MD USA) Fang Zhao-lun (Shenyang China) W. Frech (Umes Sweden) A. K. Gilrnutdinov (Uberlingen Germany) G. M. Hieftje (Bloomington IN USA) R. S. Houk (Ames OH USA) R. Klockenkihmper (Dortmund Germany) B. V. L'vov (St. Petersburg Russia) R. K. Marcus (Clemson SC USA) J. M. Mermet (Villeurbanne France) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beving China) J. W. Olesik (Columbus OH USA) N. Omenetto (lspra Italy) C. J. Park (Taejon Korea) P. J. Potts (Milton Keynes UK) R. E. Sturgeon (Ottawa Canada) V. Sychra (Prague Czech Republic) R. Van Grieken (Antwerp Belgium) P. Van Espen (Antwerp Belgium) B. Welz (Uberlingen Germany) Atomic Spectrometry Updates Editorial Board Chairman *A.T. Ellis (Abingdon UK) J. Armstrong (Edinburgh UK) *J. R. Bacon (Aberdeen UK) C. Barnard (Glasgow UK) R. M. Barnes (Amherst MA USA) S. Branch (High Wycombe UK) R. Bye (Oslo Norway) J. Carroll (Middlesbrough UK) M. R. Cave (Keyworth UK) S. Chenery (Keyworth UK) *J. M. Cook (Keyworth UK) *M. S. Cresser (Aberdeen UK) H. M. Crews (Norwich UK) J. S. Crighton (Sunbury-on-Thames UK) *J. B. Dawson (Leeds UK) J. R. Dean (Newcastle upon Tyne UK) *E. H. Evans (Plymouth UK) J. Fazakas (Budapest Hungary) A. Fisher (Plymouth UK) *J. M. Gordon (Cambridge UK) D. J. Halls (Glasgow UK) *S. J. Hill (Plymouth UK) K. W. Jackson (Albany NY USA) R. Jowit t (Middlesbrough UK ) K. Kitagawa (Nagoya Japan) J. Kubova (Bratislava Slovak Republic) *J. Marshall (Middlesbrough UK) H. Matusiewicz (Poznan Poland) A.W. McMahon (Manchester UK) J. M. Mermet (Villeurbanne France) R. G. Michel (Storrs CT USA) *D. L. Miles (Keyworth UK) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beijing China) P. J. Potts (Milton Keynes UK) W. J. Price (Budleigh Salterton UK) C. J. Rademeyer (Pretoria South Africa) A. Sanz-Medel (Oviedo Spain) *B. L. Sharp (Loughborough UK) I. L. Shuttler (Uberlingen Germany) S. T. Sparkes (Taunton UK) R. Stephens (Halifax Canada) J. Stupar (Ljubljana Slovenia) R. E. Sturgeon (Ottawa Canada) *A. Taylor (Guildford UK) G. C. Turk (Gaithersburg MD USA) J. F. Tyson (Amherst MA USA) P. Watkins (London UK) B. Welz (Uberlingen Germany) J. Williams (Egham UK) J. B. Willis (Victoria Australia) *Members of the ASU Executive Committee Editor JAAS Janice M.Gordon The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK. Telephone + 44 (0) 1223 420066. Fax + 44 (0) 1223 420247. E-mail RSC1 @RSC.ORG (Internet) Senior Assistant Editor Brenda Holliday Assistant Editor Ziva Whitelock Editorial Secretary Lesley Turney US Associate Editor JAAS Dr. J. M. Harnly US Department of Agriculture Beltsville Human Nutrition Research Center Beltsville MD 20705 USA. Telephone + 1 301 -504-8569 Asia-Pacific Associate Editor JAAS Prof. N. Furuta Department of Applied Chemistry Faculty of Science and Engineering Chuo University 1-1 3-27 Kasuga Bunkyo-ku Tokyo 11 2 Japan. Telephone 81 -3-381 7-1 906. E-mail nfuruta@apchem.chem.chuo.u.ac.jp F ~ x 81 -3-381 7-1 895. Advertisements Advertisement Department The Royal Society of Chemistry Burlington House Piccadilly London W1 V OBN UK.Telephone + 44 (0) 171 -287 3091. Fax + 44 (0) 171 -494 11 34. Information for Authors Full details of how to submit materials for publi- cation in JAAS are given in the Instructions to Authors in Issue 1. Separate copies are available on request. The Journal of Analytical Atomic Spectrometry (JAAS) is an international journal for the publi- cation of original research papers communi- cations and letters concerned with the development and analytical application of atomic spectrometric techniques. The journal is pub- lished twelve times a year including comprehen- sive reviews of specific topics of interest to practising atomic spectroscopists and incorpor- ates the literature reviews which were previously published in Annual Reports on Analytical Atomic Spectroscopy (ARAAS).Manuscripts intended for publication must describe original work related to atomic spectro- metric analysis. Papers on all aspects of the sub- ject will be accepted including fundamental studies novel instrument developments and prac- tical analytical applications. As well as AAS AES and AFS papers will be welcomed on atomic mass spectrometry X-ray fluorescence/emission spectrometry and secondary emission spec- trometry. Papers describing the measurement of molecular species where these relate to the characterization of sources normally used for the production of atoms or are concerned for example with indirect methods of analysis will also be acceptable for publication.Papers describing the development and applications of hybrid techniques (e.g. GC-coupled AAS and HPLC-ICP) will be particularly welcome. Manuscripts on other subjects of direct interest to atomic spectroscopists including sample prep- aration and dissolution and analyte pre-concen- tration procedures as well as the statistical interpretation and use of atomic spectrometric data will also be acceptable for publication. There is no page charge. The following types of papers will be considered. Full papers describing original work. Communications which must be on an urgent matter and be of obvious scientific importance. Communications receive priority and are usually published within 2-3 months of receipt. They are intended for brief descriptions of work that has progressed to a stage at which it is likely to be valuable to workers faced with similar problems.Reviews which must be a critical evaluation of the existing state of knowledge on a particular facet of analytical spectrometry. Every paper (except Communications) will be submitted to at least two referees by whose advice the Editorial Board of JAAS will be guided as to its acceptance or rejection. Papers that are accepted must not be published elsewhere except by permission. Submission of a manuscript will be regarded as an undertaking that the same material is not being considered for publication by another journal. Manuscripts (three copies typed in double spacing) should be sent to Janice M. Gordon Editor JAAS or Dr. J. M. Harnly US Associate Editor JAAS.All queries relating to the presentation and sub- mission of papers and any correspondence regarding accepted papers and proofs should be directed to the Editor or US Editor (addresses as above). Members of the JAAS Editorial Board (who may be contacted directly or via the Editorial Office) would welcome comments suggestions and advice on general policy matters concerning JAAS. Fifty reprints are supplied free of charge. Journal of Analytical Atomic Spectrometry (JAAS) (ISSN 0267-9477) is published monthly by The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK. All orders accompanied with payment should be sent directly to The Royal Society of Chemistry Turpin Distribution Services Ltd. Blackhorse Road Letchworth Herts.SG6 lHN UK Tel. +44 (0) 1462 672555; Telex 825372 Turpin G; Fax +44 (0) 1462 480947. Turpin Distribution Services Ltd. is wholly owned by The Royal Society of Chemistry. 1995 Annual subscription rate EEA f512.00 USA $941.50 Canada f538.00 (+ GST) Rest of World f538.00. Customers should make payments by cheque in sterling payable on a UK clearing bank or in US dollars payable on a US clearing bank. Air freight and mailing in the USA by Publications Expediting Inc. 200 Meacham Avenue Elmont NY 1 1 003. USA Postmaster send address changes to Journal of Analytical Atomic Spectrometry (JAAS) Publications Expediting Inc. 200 Meacham Avenue Elmont NY 1 1 003. Postage paid at Jamaica NY 11431. All other despatches outside the UK by Bulk Airmail within Europe Accelerated Surface Post outside Europe.PRINTED IN THE UK. @The Royal Society of Chemistry 1995. All rights reserved. No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photographic recording or otherwise without the prior permission of the publishers.Journal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates) JAAS Editorial Board Chairman B. L. Sharp (Loughborough UK) A. T. Ellis (Abingdon UK) J. M. Gordon (Cambridge UK) S. J. Haswell (Hull UK) S. J. Hill (Plymouth UK) R. C. Hutton (Winsford UK) D. Littlejohn (Glasgow UK) J. Marshall (Middlesbrough UK) A. Sanz-Medel (Oviedo Spain) P. D. P. Taylor (Gee/ Belgium) JAAS Advisory Board F. C. Adams (Antwerp Belgium) R.M. Barnes (Amherst MA USA) L. Bezur (Budapest Hungary) M. W. Blades (Vancouver Canada) R. F. Browner (Atlanta GA USA) J. L. Burguera (Merida Venezuela) S. Caroli (Rome Italy) J. A. Caruso (Cincinnati OH USA) H. M. Crews (Norwich UK) A. J. Curtius (Florianopolis Brazil) J. B. Dawson (Leeds UK) M. T. C. de Loos-Vollebregt (Delft The Netherlands) 0. F. X. Donard (Talence France) L. Ebdon (Plymouth UK) M. S. Epstein (Gaithersburg MD USA) Fang Zhao-lun (Shenyang China) W. Frech (UmeA Sweden) A. K. Gilmutdinov (herlingen Germany) G. M. Hieftje (Bloomington IN USA) R. S. Houk (Ames OH USA) R. Klockenkamper (Dortmund Germany) 6. V. L'vov (St. Petersburg Russia) R. K. Marcus (Clemson SC USA) J. M. Mermet (Villeurbanne France) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beuing China) J.W. Olesik (Columbus OH USA) N. Omenetto (Ispra Italy) C. J. Park (Taejon Korea) P. J. Potts (Milton Keynes UK) R. E. Sturgeon (Ottawa Canada) V. Sychra (Prague Czech Republic) P. Van Espen (Antwerp Belgium) R. Van Grjeken (Antwerp Belgium) 6. Welz (Uberlingen Germany) J. Armstrong (Edinburgh UK) *J. R. Bacon (Aberdeen UK) C. Barnard (Glasgow UK) R. M. Barnes (Amherst MA USA) S. Branch (High Wycombe UK) R. Bye (Oslo Norway) J. Carroll (Middlesbrough UK) M. R. Cave (Keyworth UK) S. Chenery (Keyworth UK) *J. M. Cook (Keyworth UK) "M. S. Cresser (Aberdeen UK) H. M. Crews (Nowich UK) J. S. Crighton (Sunbury-on-Thames UK *J. 6. Dawson (feeds UK) J. R. Dean (Newcastle upon Tyne UK) *E. H. Evans (Plymouth UK) J. Fazakas (Budapest Hungary) A. Fisher (Plymouth UK) *J.M. Gordon (Cambridge UK) D. J. Halls (Glasgow UK) *S. J. Hill (Plymouth UK) K. W. Jackson (Albany NY USA) R. Jowitt (Middlesbrough UK) K. Kitagawa (Nagoya Japan) J. Kubova (Bratislava Slovak Republic) Atomic Spectrometry Updates Editorial Board Chairman *A. T. Ellis (Abingdon UK) *J. Marshall (Middlesbrough UK) H. Matusiewicz (Poznan Poland) A. W. McMahon (Manchesler UK) J. M. Mermet (Villeurbanne France) R. G. Michel (Storrs CT USA) *D. L. Miles (Keyworth UK) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beijing China) P. J. Potts (Milton Keynes UK) W. J. Price (Budleigh Salterton UK) C. J. Rademeyer (Pretoria South Africa) A. Sanz-Medel (Oviedo Spain) *B. L. Sharp (foughborough UK) I. L. Shuttler (Uberlingen Germany) S. T. Sparkes (Taunton UK) R. Stephens (Halifax Canada) J.Stupar (Ljubljana Slovenia) R. E. Sturgeon (Ottawa Canada) *A. Taylor (Guildford UK) G. C. Turk (Gaithersburg MD USA) J. F. Tyson (Amherst MA USA) P. Watkins (London UK) 6. Welz (Uberlingen Germany) J. Williams (Egham UK) J. 6. Willis (Victoria Australia) *Members of the ASU Executive Committee Editor JAAS Janice M. Gordon The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK. Telephone +44 (0) 1223 420066. Fax + 44 (0) 1223 420247. E-mail RSCl @RSC.ORG (Internet) Senior Assistant Editor Brenda Holliday Assistant Editor Ziva Whitelock Editorial Secretary Lesley Turney US Associate Editor JAAS Dr. J. M. Harnly US Department of Agriculture Beltsville Human Nutrition Research Center Beltsville MD 20705 USA.Telephone + 1 301 -504-8560 Asia-Pacific Associate Editor JAAS Prof. N. Furuta Department of Applied Chemistry Faculty of Science and Engineering Chuo University 1-1 3-27 Kasuga Bunkyo-ku Tokyo 112 Japan. Telephone 81 -3-381 7-1 906. Fax 81 -3-381 7-1 895. E-mail nfuruta@apchem.chern.chuo.u.ac.ip Advertisements Advertisement Department The Royal Society of Chemistry Burlington House Piccadilly London W1 V OBN UK. Telephone + 44 (0) 171 -287 3091. Fax + 44 (0) 171 -494 1 134. Information for Authors Full details of how to submit materials for publi- cation in JAAS are given in the Instructions to Authors in Issue 1. Separate copies are available on request. The Journal of Analytical Atomic Spectrometry (JAAS) is an international journal for the publi- cation of original research papers communi- cations and letters concerned with the development and analytical application of atomic spectrometric techniques.The journal is pub- lished twelve times a year including comprehen- sive reviews of specific topics of interest to practising atomic spectroscopists and incorpor- ates the literature reviews which were previously published in Annual Reports on Analytical Atomic Spectroscopy (ARAAS). Manuscripts intended for publication must describe original work related to atomic spectro- metric analysis. Papers on all aspects of the sub- ject will be accepted including fundamental studies novel instrument developments and prac- tical analytical applications. As well as AAS AES and AFS papers will be welcomed on atomic mass spectrometry X-ray fluorescence/emission spectrometry and secondary emission spec- trometry.Papers describing the measurement of molecular species where these relate to the characterization of sources normally used for the production of atoms or are concerned for example with indirect methods of analysis will also be acceptable for publication. Papers describing the development and applications of hybrid techniques (e.g. GC-coupled AAS and HPLC-ICP) will be particularly welcome. Manuscripts on other subjects of direct interest to atomic spectroscopists including sample prep- aration and dissolution and analyte pre-concen- tration procedures as well as the statistical interpretation and use of atomic spectrometric data will also be acceptable for publication. There is no page charge.The following types of papers will be considered. Full papers describing original work. Communications which must be on an urgent matter and be of obvious scientific importance. Communications receive priority and are usually published within 2-3 months of receipt. They are intended for brief descriptions of work that has progressed to a stage at which it is likely to be valuable to workers faced with similar problems. Reviews which must be a critical evaluation of the existing state of knowledge on a particular facet of analytical spectrometry. Every paper (except Communications) will be submitted to at least two referees by whose advice the Editorial Board of JAAS will be guided as to its acceptance or rejection. Papers that are accepted must not be published elsewhere except by permission.Submission of a manuscript will be regarded as an undertaking that the same material is not being considered for publication by another journal. Manuscripts (three copies typed in double spacing) should be sent to Janice M. Gordon Editor JAAS or Dr. J. M. Harnly US Associate Editor JAAS. All queries relating to the presentation and sub- mission of papers and any correspondence regarding accepted papers and proofs should be directed to the Editor or US Editor (addresses as above). Members of the JAAS Editorial Board (who may be contacted directly or via the Editorial Office) would welcome comments suggestions and advice on general policy matters concerning JAAS. Fifty reprints are supplied free of charge. Journal of Analytical Atomic Spectrometry (JAAS) (ISSN 0267-9477) is published monthly by The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge C64 4WF UK.All orders accompanied with payment should be sent directly to The Royal Society of Chemistry Turpin Distribution Services Ltd. Blackhorse Road Letchworth Herts. SG6 1 HN UK Tel. +44 (0) 1462 672555; Telex 825372 Turpin G; Fax f44 (0) 1462 480947. Turpin Distribution Services Ltd. is wholly owned by The Royal Society of Chemistry. 1995 Annual subscription rate EEA €51 2.00 USA $941 50 Canada f538.00 (+ GST) Rest of World f538.00. Customers should make payments by cheque in sterling payable on a UK clearing bank or in US dollars payable on a US clearing bank. Air freight and mailing in the USA by Publications Expediting Inc. 200 Meacham Avenue Elmont NY 11003. USA Postmaster send address changes to Journal of Analytical Atomic Spectrometry (JAAS) Publications Expediting Inc. 200 Meacham Avenue Elmont NY 11 003. Postage paid at Jamaica NY 1 1 431. All other despatches outside the UK by Bulk Airmail within Europe Accelerated Surface Post outside Europe. PRINTED IN THE UK. @The Royal Society of Chemistry 1995. All rights reserved. No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photographic recording or otherwise without the prior permission of the publishers.

ISSN:0267-9477    

DOI:10.1039/JA99510FX033

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Journal of Analytical Atomic Spectrometry ' JASPE2 1 O(8) 47N-50N 51 9-562 199R-252R (1 995) CONTENTS NEWS PAGES Historical Corner 47N Diary of Conferences and Courses 47N Future Issues 48N PAPERS Selenium Speciation Using High-performance Liquid Chromatography- Hydride Generation Atomic Fluorescence with On-line Microwave Reduction Les Pitts Andy Fisher Paul Worsfold Steve J. Hill Effect of Acids Modifiers and Chloride on the Atomization of Aluminium in Electrothermal Atomic Absorption Spectrometry Shida Tang Patrick J. Parsons Walter Slavin Mechanisms Controlling Direct Solid Sampling of Silicon from Gold Samples by Electrothermal Atomic Absorption Spectrometry Part 2. Atomization from Aqueous and Solid Samples Garrett N. Brown David L. Styris Michael W. Hinds Electrothermal Atomic Absorption Spectrometric Determination of Molybdenum in Water Human Hair and High-purity Reagents with Flow Injection On-line Coprecipitation Preconcentration Hengwu Chen Shukun Xu Zhaolun Fang Direct Detection of Antimony in Environmental and Biological Samples at Trace Concentrations by Laser-induced Fluorescence in Graphite Furnace with an Intensified Charge Coupled Device Jonas Enger Alexander Marunkov Nikolai Chekalin Ove Axner Determination of Chromium in Biological Tissues by Inductively Coupled Plasma Mass Spectrometry Joseph W.H. Lam James W. McLaren Bradley A. J. Methven Determination of Trace Elements in Fuel Oils by Inductively Coupled Plasma Mass Spectrometry after Acid Mineralization of the Sample in a Microwave Oven Maurizio Bettinelli S. Spezia U.Baroni G. Biuarri CUMULATIVE AUTHOR INDEX ERRATA Determination of Scandium Yttrium and Eight Rare Earth Elements in Silicate Rocks and Six New Geological Reference Materials by Simultaneous Multi- element Electrothermal Atomic Absorption Spectrometry with Zeeman-effect Background Correction Joy G. Sen Gupta Determination of Total Chromium and Chromium(vi) in Animal Feeds by Electrothermal Atomic Absorption Spectrometry M. Elisa Soares M. Lourdes Bastos and Margarida A. Ferreira 51 9 52 1 527 533 539 55 1 555 561 562 562 AT0 M I C S P ECT R 0 M ET RY U P D AT E S Advances in Atomic Absorption and Fluorescence Spectrometry and Related Techniques References 199R 229R 1111 111111111111111111 111111111111 111111 1111 111 111111111 111111111111111111111 111 Typeset printed and bound by The Charlesworth Group Huddersfield England 01 484 51 70777 996 Winter Conference on Plasma Spectrochemistry Fort Lauderdale Florida January 8 - 73 7996 The 1996 Winter Conference on Plasma Spectrochemistry ninth in a series of biennial meetings sponsored by the ICP lnformafion Newsletter features developments in plasma spectrochemical analysis by inductively coupled plasma (ICP) dc plasma (DCP) microwave plasma (MIP) and glow discharge (GDL HCL) sources.The meeting will be held Monday January 8 through Saturday January 13 1996 at the Bonaventure World Conference Center in Fort Lauderdale Florida. Continuing education short courses at introductory and advanced levels will be offered Friday through Sunday January 5 - 7. Spectroscopic instrumentation and accessories will be shown during a three-day exhi bition.Objectives and Program The continued growth in popularity of plasma sources far atomization and excitation in atomic spectroscopy and ionization in mass spectrometry and the need to discuss recent developments of these discharges in spectrochemical analysis stimulated the organization of this meeting. The Conference will bring together international scientists experienced in applications instrumentation and theory in an informal setting to examine recent progress in the field. Approximately 500 participants from 25 countries are expected to attend. Approximately 300 papers describing applications fundamentals and instrumental developments with plasma sources are expected to be presented in lecture and poster sessions by more than 200 authors.Symposia organized and chaired by recognized experts will include the following topics 1) Sample introduction and transport phenomena 2) Flow injection spectrochemical analysis 3) Elemental speciation with plasma/chromatographic techniques 4) Plasma instrumentation including chemometrics expert systems on-line analysis software and remote-system automation 5) Sample preparation treatment and automation 6) Excitation mechanisms and plasma phenomena 7) Spectroscopic standards and reference materials 8) Plasma source mass spectrometry 9) Glow discharge atomic and mass spectrometry 10) Applications of stable isotope analyses and 1 1 ) Laser-assisted plasma spectrometry. Six plenary and 1 8 invited lectures will highlight advances in these areas.Afternoon poster sessions will feature applications automation and new instrumentation. Five panel discussions will address critical development areas in sample introduction instrumentation elemental speciation plasma source mass spectrometry and novel software and hardware directions. Plenary invited and submitted papers will be published in Fall 1996 after peer review as the official Conference proceedings. Schedule of Activities Preliminary Title and 50-Word Abstract Due for Contributed Papers July 3 1995 Exhibitor Booth Reservation and Pre-Registration Deadline September 11,1995 Conference P re- Registration October 13,1995 Hotel Pre-Reservation October 13 1995 Late Pre-Registration Deadline December 8,1995 1996 Winter Conference Short Courses January 5 - 7,1996 1 996 Winter Conference on Plasma Spectrochemistry January 8 - 13,1996 Further Information For further information return this form to 1996 Winter Conference on Plasma Spectrochemistry %/CP Information Newsletter Department of Chemistry Lederle GRC Towers University of Massachusetts Box 34510 Amherst MA 01003-451 0 USA. AUN Dr. Ramon Barnes Conference Chairman Telephone (41 3) 545-2294 Telefax (41 3) 545-4490. 3F R Send further information. R I plan to attend accompanied by R I plan to present a paper (D oral CI poster 0 computer poster). Title 1996 WINTER CONFERENCE ON PLASMA SPECTROCHEMISTRY Name Organization Address City Telephone Title State/Country Telefax Date ZIP/Postal Code EMAIL

ISSN:0267-9477    

DOI:10.1039/JA99510BX035

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

DIARY OF CONFERENCES AND COURSES 1995 8th International Conference on Coal Science September 10-15 Instituto Nacional del Carbbn CSIC Apartado 73 33080 Oviedo Spain Details can be found in J. Anal. At. Spectrom. 1994 9 61N. For further details contact Dr. Juan M. D. Taschn 8th ICCS Scientific Programme Chairman Instituto Nacional del Carbon CSIC Apartado 73 33080 Oviedo Spain. Telephone + 34.8.528.08.00; Fax + 34.8.529.76.62. Sixth Surrey Conference on Plasma Source Spectrometry September 17-20 Jersey UK Details can be found in J. Anal. At. Spectrom. 1995 10 19N. For further details contact Dr. K. Jarvis NERC ICP-MS Facility Centre for Analytical Res. in the Environment (CARE) Imperial College at Silwood Park Buckhurst Road Ascot Berkshire SL5 7TE UK. Telephone +44(0) 344 294517; Fax +44(0) 344 873997.European Workshop in Chemometrics September 17-22 Bristol UK Details can be found in J. Anal. At. Spectrom. 1995 10 24N. For further details contact Mrs. C. Hutcheon School of Chemistry University of Bristol Contock's Close Bristol BS8 lTS UK. Telephone + 44(0) 117-928 7645 ext. 4221; Fax +44-(0)117-925 1295. Federation of Analytical Chemistry and Spectroscopy Societies Conference October 15-20 Cincinnati Ohio USA Details can be found in J. Anal. At. Spectrom. 1995 10 19N. For further information contact Joseph A. Caruso FACSS National Office 198 Thomas Johnson Dr. Suite S-2 Frederick MD 21702 USA. Telephone (301) 694-8122; Fax (301) 694-6860. Short Course COSHH October 31-November 1 Shefield UK Details can be found in J. Anal. At.Spectrom. 1995 10 34N. For further information contact Ms Baldham or Ms Rogers Division of Adult Contiuning Education University of Sheffield 196-198 West Street Sheffield S1 4CT UK. Telephone 0114 2825391; Fax 0114 2768653 First Mediterranean Basin Conference on Analytical Chemistry November 5-10 Chdoba Spain For further details contact Prof. Alfred0 Sanz-Medel Department of Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 47 NPhysical and Analytical Chemistry Faculty of Chemistry. University of Oviedo C/ Julian Claveria no 8. 3006 Oviedo (Spain). Telephone 34/85/ 103474-103485; Fax 34/85/103480. Short Course Environmental Auditing in Manufacturing and Process Industries November 7 Shefield UK Details can be found in J. Anal. At. Spectrom.1995 10 34N. For further information contact Ms Baldham or Ms Rogers Division of Adult Continuing Education University of Sheffield 196-198 West Street Sheffield S1 4CT UK. Telephone 01 14 2825391; Fax 01 14 2768653 Biological Applications of Inorganic Mass Spectrometry November 8-9 Norwich UK Details can be found in J. Anal. At. Spectrom. 1995 10 20N. For further information contact Dr. Fred Mellon Institute of Food Research Norwich Laboratory Norwich Research Park Colney Norwich NR4 7UA UK. Telephone +44(0)1603 255 299 (direct line) +44 (0) 1603 255 000 (switchboard/paging); Fax +44 (0)1603 452578 +44 (0)1603 fred.mellon@BBSRC. AC.UK. 507723; E-MAIL Short Course Safe Storage of Hazardous Substances November 23 Shefield UK Details can be found in J. Anal. At. Spectrom.1995 10 34N. For further information contact Ms Baldham or Ms Rogers Division of Adult Continuing Education University of Sheffiekd 196-198 West Street Sheffield S1 4CT UK. Telephone 01 14 2825391; Fax 01 14 2768653 Short Course Disposal of Hazardous Waste December 5 Shefield UK Details can be found in J. Anal. At. Spectrom. 1995 10 334N. For further information contact Ms Baldham or Ms Rogers Division of Adult Continuing Education University of Sheffield 196-198 West Street Sheffield S1 4CT UK. Telephone 01 14 2825391; Fax 01 14 2768653 International Symposium on Environmental Biomonitoring and Specimen Banking December 17-22 Honolulu Hawaii USA Details can be found in J. Anal. At. Spectrom. 1994 9 59N. For further information contact K. S . Subramanian Environment a1 Health Directorate Health Canada Tunney’s Pasture Ottawa Onfario K1A OL2 Canada (phone 61 3-957-1 874; fax 613-941-4545) or G.‘V. Iyengar Center for Analytical Chemistry Room 235 B 125 National Institute of Standards and Technology Gaithersburg MD 20899 USA (Telephone 301-975-6284; Fax 301-921-9847) oir M. Morita Division of Chemistry and Physics National Institute for Environmental Studies Japan Environmental Agency Yatabe-Machi Tsukuba Ibaraki 305 Japan (Telephone 81-298-51-6111 ext. 260; Fax 81-298-56-4678). 1996 19% Winter Conference on Plasma Spectrochemistry January 8-13 Fort Lauderdale Florida USA Details can be found in J. Anal. At. Spectrom. 1994,9,53N. For further information contact Dr. R. Barnes ICP Information Newsletter Department of Chemistry Lederle GRC Towers University of Massachusetts Box 34510 Amherst MA 01003-4510 USA Telephone (41 3) 545 2294; Telefax (413) 545 4490.International Schools and Conferences on X-Ray Analytical Methods January 18-25 Sydney Australia Details can be found in J. Anal. At. Spectrom. 1994,9,47N. For further information contact AXAA ’96 Secretariat GPO Box 128 Sydney NSW 2001 Australia. Telephone 61 2 262 2277; Fax 61 2 262 2323; Telex AA 176511 TRHOST. Analytica Conference 96 April 23-26 Munich Germany Details can be found in J. Anal. At. Spectrom. 1994,2,69N. For further information contact Messe Miinchen GmbH Messegelande D-80325 Munchen Germany. Telephone + 49 89 51 07-0; Telex 5 212 086 ameg d; Fax +49 89 51 07-177. Eighth Biennial National Atomic Spectroscopy Symposium University of East Anglia Norwich UK For further information contact Dr. S . J. Haswell School of Chemistry University of Hull Hull HU6 7RX UK. Telephone + 44 (0)482-465469; Fax +44 (0)482-466410. July 17-19 48 N Journal of Analytical Atomic Spectrometry August 1995 Vol. 10

ISSN:0267-9477    

DOI:10.1039/JA99510047Nb

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

~ FUTURE ISSUES WILL INCLUDE- Quantitative Depth Profile Analysis by Glow Discharge Optical Emission Spectrometry-Zdenek Weiss Chemical Modifiers for Controlling Interferences in the Atomic Absorption Spectrometric Determination of Cr"' and CrV' and Their Separation- M. A. Kabil Software Development for Atomic Absorption Spectrometry-A Decade of Progress-Zhe-Ming Ni Yan-Zhong Liang Peng-Yuan Yang Determination of Mercury by Electrothermal Atomic Absorption Spectrometry Using Different Chemical Modifiers or Slurry Technique- I. Karadjova Petko B. Mandjukov S. Tsakovsky V. Simeonov John A. Stratis George A. Zachariadis Detection Limits in Zeeman Graphite Furnace Atomic Absorption Spectrometry-Boris 'V. L'vov Leonid K. Polzik Alexander V. Horodin Alexey 0. Dyakov Alexander V.Novichikhin Polyatomic Ions as Internal Standards for Matrix Corrections in Inductively Coupled Plasma Mass Spectrometry- Xiaoshan Chen R. S. Houk Universal Temperature Programmes for Modifier-free Electro t henna1 Atomic Absorption Spectrometry of Trace Elements in Pharmaceuticals- S. Arpadjan Anka Alexandrova Separation and Determination of Sb"' and SbV Species by High-performance Liquid Chromatography with Hydride 48 N Journal of Analytical Atomic Spectrometry August 1995 Vol. 10Generation Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry-Patricia N. Smichowski Yolanda Madrid M. B. De La Calle Guntinas Carmen Camara Basic Investigations on Nanosecond Laser-induced Plasma Emission Kinetics for Quantitative Elemental Microanalysis of High Alloys- Bela Nemet Laszlo Kozma Effect of Laser Parameters and Tooth Type on the Ablation of Trace Metals from Mammalian Teeth-Peter M.Outridge R. Douglas Evans Sensitive Determination of Selenium by Inductively Coupled Plasma Mass Spectrometry with Flow Injection and Hydride Generation in the Presence of Organic Solvents-Riansares Munoz Olivas Christophe R. Quetel Oliver F. X. Donard Measurement of Mercury Methylation in Sediments by Using Enriched Stable Mercury Isotopes Combined with Methylmercury Determination by Gas Chromatography - Inductively Coupled Plasma Mass Spectrometry-Holger Hinteimann R. Douglas Evans Janice Y. Villeneuve Some Figures of Merit of a New Double Focusing Inductively Coupled Plasma Mass Spectrometer-Luc Moens Frank Vanhaecke Jorgen Riondato Richard Dams Evaluation of the Direct Injection Nebulizer in the Coupling of High- performance Liquid Chromatography with Inductively Coupled Plasma Mass Spectrometry- Grace Zooro b Med ha J.Tomiinson Jianshang Wang Joseph A. Caruso Improving Design of a Water Cooled Atom Trap to Increase Sensitivity- David J. Roberts Andrew D. Turner Yann Le Cor Determination of Elevated Levels of Dysprosium in Serum by Electrothermal Atomic Absorption Spectrophotometry-Einar Knutsen Grethe Wibetoe Ivar Martinsen Signal-to-Noise Ratios for Organolead Species in Coupled Gas Chromatography-Atomic Absorption Spectrometry Using Quartz Tube Atomizers-Magnus Johansson Douglas C. Baxter Wolfgang Frech Inductively Coupled Plasma Mass Spectrometric Detection of Lead Compounds Separated by Liquid Chromatograph y-Hueih- Jen Yang Shiuh-Jen Jiang Reduction of Gaseous-phase Interference in Hydride Generation Using Inductively Coupled Plasma Atomic Emission Determination of Selenium in Nickel Alloys and Low- alloy Steels-Torild Wickstrom Walter Lund Ragnar Bye Spectroscopic Method for the Determination of the Electron Temperature in Quasi-thermal Air Discharges-A.M. Gomes J. P. Sarrette Lydie Madon Arnaud Epifanie Determination of Trace Amounts of Thallium in Telluride Thermoelectric Material by Electrothermal Atomic Absorption Spectrometry Testing of Chemical Modifiers-Jitka Sramkova Stan Kotrly Katerina Dolezalova Determination of Total Mercury in Natural Gases Using the Amalgamation Technique and Cold Vapour Atomic Absorption Spectrometry-Wolfgang Frech Douglas C.Baxter Geir Dyvik Bjorn Dybdahl Determination of Antimony by Continuous Hydride Generation Coupled with Non-dispersive Atomic Fluorescence Detection-Alessandro D’Ulivo Leonard0 Lampugnani Giovanna Pellegrini Roberto Zamboni Analytical and Spectroscopic Characterization of Double Resonance Laser-induced Fluorescence of Gold Atoms in a Graphite Furnace and Flame-G. A. Petrucci H. Beissler 0. I. Matveev Paolo Cavalli Nicolo Omenetto COPIES OF CITED ARTICLES The Royal Society of Chemistry Library can usually supply copies of cited articles. For further details contact The Library Royal Society of Chemistry Burlington House Piccadilly London W1V OBN UK. Tel +44 (0) 71-437 8565; fax +44 (0) 71-287 9798; Telecom Gold 84; BUR210; Electronic Mailbox (Internet) LIBRARY@RSC.ORG. If the material is not available from the Society’s Library the staff will be pleased to advise on its availability from other sources.Please note that copies are not available from the RSC at Thomas Graham House Cambridge. Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 49 NGeneration Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry-Patricia N. Smichowski Yolanda Madrid M. B. De La Calle Guntinas Carmen Camara Basic Investigations on Nanosecond Laser-induced Plasma Emission Kinetics for Quantitative Elemental Microanalysis of High Alloys- Bela Nemet Laszlo Kozma Effect of Laser Parameters and Tooth Type on the Ablation of Trace Metals from Mammalian Teeth-Peter M.Outridge R. Douglas Evans Sensitive Determination of Selenium by Inductively Coupled Plasma Mass Spectrometry with Flow Injection and Hydride Generation in the Presence of Organic Solvents-Riansares Munoz Olivas Christophe R. Quetel Oliver F. X. Donard Measurement of Mercury Methylation in Sediments by Using Enriched Stable Mercury Isotopes Combined with Methylmercury Determination by Gas Chromatography - Inductively Coupled Plasma Mass Spectrometry-Holger Hinteimann R. Douglas Evans Janice Y. Villeneuve Some Figures of Merit of a New Double Focusing Inductively Coupled Plasma Mass Spectrometer-Luc Moens Frank Vanhaecke Jorgen Riondato Richard Dams Evaluation of the Direct Injection Nebulizer in the Coupling of High- performance Liquid Chromatography with Inductively Coupled Plasma Mass Spectrometry- Grace Zooro b Med ha J.Tomiinson Jianshang Wang Joseph A. Caruso Improving Design of a Water Cooled Atom Trap to Increase Sensitivity- David J. Roberts Andrew D. Turner Yann Le Cor Determination of Elevated Levels of Dysprosium in Serum by Electrothermal Atomic Absorption Spectrophotometry-Einar Knutsen Grethe Wibetoe Ivar Martinsen Signal-to-Noise Ratios for Organolead Species in Coupled Gas Chromatography-Atomic Absorption Spectrometry Using Quartz Tube Atomizers-Magnus Johansson Douglas C. Baxter Wolfgang Frech Inductively Coupled Plasma Mass Spectrometric Detection of Lead Compounds Separated by Liquid Chromatograph y-Hueih- Jen Yang Shiuh-Jen Jiang Reduction of Gaseous-phase Interference in Hydride Generation Using Inductively Coupled Plasma Atomic Emission Determination of Selenium in Nickel Alloys and Low- alloy Steels-Torild Wickstrom Walter Lund Ragnar Bye Spectroscopic Method for the Determination of the Electron Temperature in Quasi-thermal Air Discharges-A.M. Gomes J. P. Sarrette Lydie Madon Arnaud Epifanie Determination of Trace Amounts of Thallium in Telluride Thermoelectric Material by Electrothermal Atomic Absorption Spectrometry Testing of Chemical Modifiers-Jitka Sramkova Stan Kotrly Katerina Dolezalova Determination of Total Mercury in Natural Gases Using the Amalgamation Technique and Cold Vapour Atomic Absorption Spectrometry-Wolfgang Frech Douglas C. Baxter Geir Dyvik Bjorn Dybdahl Determination of Antimony by Continuous Hydride Generation Coupled with Non-dispersive Atomic Fluorescence Detection-Alessandro D’Ulivo Leonard0 Lampugnani Giovanna Pellegrini Roberto Zamboni Analytical and Spectroscopic Characterization of Double Resonance Laser-induced Fluorescence of Gold Atoms in a Graphite Furnace and Flame-G. A. Petrucci H. Beissler 0. I. Matveev Paolo Cavalli Nicolo Omenetto COPIES OF CITED ARTICLES The Royal Society of Chemistry Library can usually supply copies of cited articles. For further details contact The Library Royal Society of Chemistry Burlington House Piccadilly London W1V OBN UK. Tel +44 (0) 71-437 8565; fax +44 (0) 71-287 9798; Telecom Gold 84; BUR210; Electronic Mailbox (Internet) LIBRARY@RSC.ORG. If the material is not available from the Society’s Library the staff will be pleased to advise on its availability from other sources. Please note that copies are not available from the RSC at Thomas Graham House Cambridge. Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 49 N

ISSN:0267-9477    

DOI:10.1039/JA995100048N

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Atomic Spectrometry Update- Advances in Atomic Absorption and Fluorescence Spectrometry and Related Techniques STEVE J. HILL* Department of Environmental Sciences University of Plymouth Plymouth Devon UK PL4 8AA JOHN B. DAWSON Department of Instrumentation and Analytical Science UMIST P.O. Box 88 Manchester UK MK60 1 QD W. JOHN PRICE Ellenmoor East Budleigh Budleigh Salterton Devon UK EX9 7DQ IAN L. SHUTTLER Bodenseewerk Perkin-Elmer GmbH Postfach 101 761 0-88647 Uberlingen Germany JULIAN F. TYSON Department of Chemistry University of Massachusetts Box 3451 0 Amherst M A 01 003-451 0 USA SUMMARY OF CONTENTS 1. Atomic Absorption Spectrometry 1.1. Flame Atomizers 1.1.1. Fundamental studies 1.1.2. Interference studies 1.1.3. Sample introduction 1.1.3.1. Discrete procedures 1.1.3.2.Atom-trapping techniques 1.1.3.3. Sample introduction by flow injection 1.1.3.4. Solid sample introduction 1.1.3.5. Thermospray introduction 1.1.3.6. High-pressure nebulization 1.1.4. Sample pre-treatment 1.1.5. Chromatographic detection 1.1.6. Plasma atomizers 1.2. Electrothermal Atomizers 1.2.1. 1.2.1.1. Graphite atomizers 1.2.1.2. Metal atomizers and metallic coatings 1.2.2. Sample introduction 1.2.2.1. Slurry sampling 1.2.2.2. Solid sampling 1.2.2.3. Gas sampling 1.2.2.4. Coupled techniques and preconcentration 1.2.2.5. Electrodeposition 1.2.3. Fundamental processes 1.2.4. Interferences 1.2.4.1. Spectral interferences 1.2.4.2. Chemical modifiers-general Atomizer design and surface modification This review follows on from last year’s review (J. Anal.At. Spectrom. 1994 9 213R) and describes the developments in atomic absorption and atomic fluorescence spectrometry since that time. Included in this review are fundamental processes and instrumentation in the areas of atomic absorption and atomic fluorescence spectrometry together with advances in related techniques such as atomic magneto-optical rotation spectrometry and laser-enhanced ionization. The review of ‘Atomic Emission Spectrometry’ may be found in JAAS Volume 10 Issue 4. With respect to section 1.2 Electrothermal Atomizers some changes have been “Review Coordinator to whom correspondence should be addressed. Atomic Spectrometry Update 1.2.4.3. Chemical modifiers-palladium 1.2.4.4. Other chemical modifiers 1.2.5. Developments in technique 1.3. Chemical Vapour Generation 1.3.1.Hydride generation 1.3.1.1. General studies of fundamentals techniques and 1.3.1.2. Determination of individual elements instrumentation 1.3.2. 1.3.3. 1.4. 1.4.1. 1.4.2. 1.4.3. 1.5. 1.5.1. 1.5.2. 1.5.3. 2. 2.1. 2.2. 2.3. 3. Mercury by cold vapour generation Volatile organo-metallic compound generation and metal vapour separation Spectrometers Light sources Continuum source and simultaneous multi-element AAS Background correction in AAS Instrument Control and Data Processing Instrument control Data processing Chemome t rics Atomic Fluorescence Spectrometry Discharge Lamp-excited Atomic Fluorescence Laser-excited Atomic Fluorescence Studies of Flames Plasmas and Atomic Vapours Using Laser-induced Fluorescence Laser Enhanced Ionization implemented.The larger sections have been divided into sub- sections to allow easier and quicker access to material covering a specific area. Much of the work previously reported under section 1.2.5 Developments in technique was being duplicated in section 1.4 Spectrometers. In the present Update a more rigorous division of the subject matter bas been applied in an attempt to reduce the size of the Electrothermal Atomizers section which in the opinion of the Update authors was becoming rather long. Consequently some work that was previously discussed under section 1.2.5 will now be found under sections 1.4 and 1.5. The full references names and addresses of authors can be readily found from the Atomic Spectrometry Updates References in the relevant issue of JAAS. However as an additional service to readers an abbreviated form of each reference quoted (except for those of Journal of Analytical Atomic Spectrometry August 1995 Vol.10 199 RConference Abstracts) is given at the end of the review. Comments as to these changes and possible improvements for future reviews are welcomed by the review coordinator. carbon black to remove the interference of aluminium on the determination of Mg in a Mg-A1 alloy but found that the procedure was ineffective in the cases of Ba Ca and Sr. The effects of a number of other organic additives have been 1. ATOMIC ABSORPTION SPECTROMETRY 1.1. Flame Atomizers The material published during this review period is very similar to that of the previous year (see J. Anal. At. Spectrom. 1994 9,213R) in that the amount of published work of a fundamental nature was relatively small in comparison with that describing particular determinations and novel aspect of sample pretreat- ment.If the sample pretreatment was directly coupled to the instrument then the work has been included in section 1.1.3. if the pretreatment was not directly coupled then the paper is included in section 1.1.4. only if the work contains some feature that could be exploited in an on-line situation. 1.1.1. Fundamental studies The imaging of OH (by LIF) and the study of temperature distributions (from Rayleigh scattering) in turbulent diffusion flames were described (94/3279) by Kelman and Masri. A laminar flow air-CH flame was used for calibration purposes. The fuels studied were compressed natural gas (CNG) a mixture of CNG and hydrogen and a mixture of hydrogen and argon.These latter two mixtures were chosen because their Rayleigh cross section is close to that of air (used in all cases as the oxidant). The authors validated the results of their study by showing that good agreement was obtained between measured values and calculated values for the model (air-CH,) flame system. This flame was also the object of a study of CO and temperature distributions (94/2240). A tuneable diode laser (output between 2090 and 2160cm-’) was used as the light source for absorbance and wavelength modulation (second derivative) studies. Good agreement with the results of previous studies based on LIF and quartz microprobe MS experiments was obtained. Useful data concerning the production of CO the agent largely responsible for loss of life in the ceiling layers of room fires was provided. 1.1.2.Interference studies Further work on the interference of aluminium on the alkaline earth elements in the air-C,H flame has been reported by Welz and Lueke (94/2399 94/3349). The phenomenon under investigation is the restoration of the analyte signal (to a value approaching that obtained in the absence of aluminium) as the aluminium concentration is increased beyond that needed to produce a signal suppression. In the first of these studies (94/2399) the effect of aluminium nitrate and chloride on Ca Mg and Sr was investigated and it was concluded that the influence of the chloride was less pronounced because the analyte chloride must be converted to the oxide before it reacts with the aluminium oxide.Any compound that delays the formation of oxide will alleviate the depressing effect of alu- minium and when higher concentrations of aluminium (as chloride) are introduced the larger particles produced isolate the analyte atoms from the oxygen in the flame owing to the production of a hydrogen chloride atmosphere. The effect of caesium chloride addition a further release from the depressive effect of aluminium was interpreted as supporting the proposed mechanism. In the second study (94/2399) the effect of a h - minium on Ba and Sr was reported. The roles of the releasing agents lanthanum EDTA and quinolin-8-01 were investigated and it was found that although lanthanum and ETDA were effective in the N20-C2H2 flame quinolin-8-01 was the best for both analytes.None of the releasing agents was effective in the cooler air-C,H flame. Japanese workers (95/124) used studied. Brilliant green was shown (95/38) to act a a releasing agent in the determination of Rh. The interferences of a number of anions and cations in the determination of Au have been quantified (94/3244) and a number of possible releasing agents evaluated. The most effective releasing agent was triethanolam- ine which was also used in the froth flotation preconcentration and separation of Au from spiked natural water samples. An overview of the role ofsurfactant-based ordered media in analytical atomic spectrometry has been provided by Sanz- Medel et al. (94/3036). This paper briefly describes some of the recent results on the use of surfactants to improve the sample introduction characteristics of FAAS from which the authors concluded that ‘much more work is needed to unveil such mechanisms of surfactant signal enhancement or surfac- tant interference elimination in flames’.Disappointingly it was also concluded that ‘trial and error techniques are mandatory’. The use of surfactants to form oil-in-water emulsions as a means of introducing non-aqueous samples was also discussed. A study (94/2203) of the effect of acetone ethanol ethylene glycol glycerol and 1,4-dioxane on the signals for Ca Cd Cu and Fe provides a good example of this trial and error approach. Changes in signal intensity as a function of density surface tension and viscosity in accordance with an empirical equation derived by Greenfield et al.(Anal. Chim. Acta 1976 84 67) were found. For Cd Cu and Fe signal enhancements of up to 1.8-times were obtained with 40% ethanol solutions. For Ca none of the solvents produced much of an enhancement or a depression. The effects were slightly more pronounced for introduction into a plasma spectrometer. Chinese workers (95/291) have studied the effects of a number of surfactants on the signal for Yb. Sodium hexylsulfonate and sodium laurylsul- fonate were found to be helpful in overcoming interferences from some concomitants. In a study of the sequential extraction oftrace elementsfrom soils according to standard protocols it was found that the presence of ammonium acetate gave high results in the determi- nation of Cd Cr and Ni (95/119).It was suggested that matrix matching be used in this case. For multiplicative interferences in the analysis of poultry feed use of the method of standard additions was advocated (95/412). 1.1.3. Sample introduction Work discussed in the previous section on the use of organic additives is relevant to this section as are some of the studies described later in section 1.1.4. in which an organic solvent was nebulized directly into the flame. Apart from the small amount of work on high pressure nebulization and thermo- spray devices (see sections 1.1.3.5. and 1.1.3.6.) which seems to be at a lower level of activity than for the previous review period (see J. Anal. At. Spectrom. 1994 9 213R) most of the research reported in the literature has been concerned with the application of commercially available pneumatic nebulizers.Chinese workers described (94/3052) a vertically mounted nebulizer which used gravity to discriminate between the larger droplets and those small enough to be entrained into the surrounding gas stream. 1.1.3.1. Discrete procedures. Conceptually there is only a small difference between the use of FI sample introduction and the use of a discrete micro-sampling system. A system which could be considered to be either was described by Xu and Fang (94/C3378) in that the sample was transported by air and introduced into the nebulizer via hydrodynamic injec- tion. The system was used for the determination of Cu in serum at a rate of about 100 h-’ with a total sample consump- 200R Journal of Analytical Atomic Spectrometry August 1995 Vol.10tion of 800 pl for triplicate injections. The same matrix has been analysed by other Chinese workers (94/2625). Calcium Cu and Mg were determined at ppm concentrations with precisions between 2 and 6% RSD. The technique has also been applied (95/402) to the determination of these analytes and Zn in whole blood. The direct nebulization of organic solvents that would extinguish the flame under normal circumstances has been described (95/304). Eight chelating agents were used in con- junction with three chlorinated solvents (dichloromethane chloroform and carbon tetrachloride). Volumes injected ranged from 20 to 50 p.1 and both the air-C2H and N20-C2H flames were used. The best performance was obtained for Ag Cd Pb and Zn but acceptable results were also found for Co Cu Fe Mg Mn and Ni.For the air-C2H2 flame there was a depen- dence of signal shape on the element that correlated with both the ash/atomize behaviour in a graphite furnace atomizer and the metal-oxygen bond strength. The height of the initial transient signal to the steady-state signal depended on the effect of flame temperature on the degree of atomization which in turn was reflected in the ease of atomization of the metal from an oxide precursor. The authors have also described (95/55) some further applications of the procedure in the analyses of biological botanical and silicaceous materials following microwave digestion. An adjustable volume (10-100 p l ) sampling device has been described by Russian workers (95/174) and Chinese workers have combined discrete sampling with a stainless steel slotted tube atom retarder for the determination of Cd Pb and Zn in atmospheric particulates (94/C3414).The increased sensitivity available allowed sample collection times to be reduced from 10 to 2 h. 1.1.3.2. Atom-trapping techniques. Despite the sustained efforts of a number of Chinese research groups there would appear to be few significant improvements in slotted tube atom retarder (STAR) performance since the original work by Watling (Anal. Chim. Acta 1977 94 181; and 1978 97 395). Further work on metallurgical analyses (94/3336) by Thorburn Burns et al. has demonstrated the improved precision that is possible with a STAR. Tin was accurately determined in a number of alloys at concentrations ranging from 0.7 to 9.8 % m/m with precisions ranging from 0.2 to 1.4 YO RSD which was 2-3 times better than that obtained with conventional nebulization. A sensitivity enhancement of a factor of 2 was obtained and it was observed that the presence of copper ( 1000 ppm) decreased the interferences from antimony arsenic bismuth chromium lead manganese nickel and zinc.As might be expected for easily atomized elements prelimi- nary results (94/3296) for the introduction of organometullic compounds in IBMK have demonstrated that enhancement effects due to the organic solvent are also observed with the STAR. Sensitivity increases of factors of 11 6 and 9 were obtained for Ag Cu and Pb respectively. No improvement was obtained for Fe and Ni which was interpreted as being due to the poorer degree of atomization in the cooler gases within the quartz tube.Chinese workers have used a STAR in the determination of Cu in rice (95/391) and a combined STAR and atom trap (94/1360) for the determination of Ag Au Cu Pb and Zn. Sensitivity enhancements by factors of 62 106 28 83 and 77 were obtained respectively. The device was used in the accurate determination of Ag and Cu in standard oyster samples. A stainless steel STAR has been used (94/C3414) in a procedure for the determination of Cd Pb and Zn in atmospheric particulates which also used discrete nebulization (see section 1.1.3.1 .). 1.1.3.3. Sample introduction by flow injection. As has now been the pattern for several years much of the novel work on the development of methods with flame AAS detection involves FI.Flow injection techniques with a variety of spectrometric detectors have been reviewed (95/5) and recent developments in the particular application for chemical vapour generation AAS surveyed (94/C3383). Welz and Sperling reviewed the FI atomic spectrometry combination (FIAS) under the title of 'the ultimate approach to automation in analytical atomic spectroscopy' (95/152). In addition to the usual examples of microsampling preconcentration and matrix removal a pro- cess analysis application was described in which the Bi concen- tration in the acid cleaning solution applied to aircraft engine blades was automatically monitored. Provided full automation is not needed the hardware needed to implement an FI sample introduction system can be very inexpensive indeed.The use of low cost components (home made injection valve and aquarium pump) was shown (94/3015) to give adequate performance for the determination of Ca K and Na by FAES. At the other end of the cost scale a new high pressure nebulizer device (see section 1.1.3.6.) with potential for use in LC applications has been evaluated in the FI mode (Todoli et a!. Spectrochim Acta Part B 1993 48 1461 ). Several applications which exploited the microsampling characteristics of FI have been described. Calcium has been determined along with phosphate in serum (95/399) and Hg measured in blood saliva and urine (94/1838). In the latter procedure an off-line microwave digestion was used. A pro- cedure involving on-line microwave digestion for the determi- nation of Cu and Zn in whole blood was developed (94/2228) in which the patient was connected directly into the FI manifold.After mixing with an anticoagulant and acid the sample passed through a microwave oven and after degassing introduced into the nebulizer of a flame spectrometer. On-line microwave digestion has also been applied (94/3034) in the determination of Cu Mn Pb and Zn in a variety of solid matrices including vegetables and sewage sludge. The samples were slurried (20 mg ml-') in concentrated nitric acid and 1 0 0 ~ 1 portions of slurry injected and merged with the same volume of 30% hydrogen peroxide solution. After passage through the 650 W oven the solution was delivered to a specially designed vessel which allowed evolved gases to escape and the nebulizer to aspirate solution at the optimum rate.Accurate results were obtained apart from low recoveries of Zn from sewage sludge. Flow injection slurry nebulization has been applied for a variety of determinations including Ca Fe Mg Mn and Zn in vegetables (94/3287) Ca Fe and Mg in materials with a high silica content (94/3035) and Fe and Mn in cement (94/3330). In the first of these studies (94/3287) Tyson's reversed FI standard additions method was used as well as calibration against aqueous standards. A sample volume of 150 pl was injected into a carrier flowing at 1.8 ml min-'. Air compensation was used. For the final study (94/3330) volumes of up to 200 pl were injected into a carrier stream flowing at 4ml min-'.No air compensation was used. All three studies employed a high dispersion manifold consisting of a single well-stirred mixing tank for the dilution of off- range concentrations. A method for dealing with the high dissolved solids arising from metal and rock samples has been devised (94/2623) in which gelatin was added to the sample solution. Detection limits of 20 and long g-' were obtained for Ag and Cu respectively. Highly concentrated sample solutions were delib- erately prepared for the determination of Pb in paint chips by FI-FAAS (94/C1938) so as to achieve a lower limit of detection in the solid by avoiding the dilution necessary to avoid clogging of the nebulizer and burner when conventional nebulization is employed. A number of flow-based systems for sample dilution and calibration have been described (94/2254 94/2922 95/305 95/451).In the first of these (94/2254) a small volume (down Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 201 Rto 0.7 pl) was introduced into the loop of the injection valve by controlled rotation of the stepper-motor driven peristaltic pump head. On switching the valve to the inject position this small volume was then washed out into a knotted tubular reactor to give dilution factors up to 1330 (with a precision of 2% RSD). The power of the procedure was demonstrated by the accurate determination of Mg in an aluminium reference alloy at a concentration of 7.17% m/m. A similar approach (95/305) has been used with a voltage controlled peristaltic pump.The same pump was used both to aspirate sample solution into the loop of the injection valve and to deliver the carrier stream to the spectrometer. With the valve in the fill position and a low applied voltage a small volume (down to 1.5 pl) was drawn into the loop. The valve was switched to the inject position and the voltage ramped linearly up to a suitable value for introduction to the spectrometer. A T-piece located in front of the nebulizer allowed compensation by a diluent so as to keep the flow into the nebulizer constant. Dilution factors up to 2000 were obtained with precisions for peak area measurements of between 0.6 and 2.3% RSD. Results of experiments designed to test the hypothesis that the problems associated with poor repeatability of small volumes metered by peristaltic pumps can only be solved by the use of combinations of pump rate and metering times such that the product is an integer multiple of the period of the rollers' pulse showed that this idea had some merit.A variable injection volume device for the implementation of the standard additions method has been described by Brazilian workers (94/3112). The use of a dialysis membrane as a method of sub-sampling is well known and further evidence of the practical use of this method for the analysis of clinical samples has been provided (95/451). Dialysis and stream splitting were used to bring the amount of Ca and Na in serum samples introduced into the spectrometer into the working range. A full description of the use of discontinuous flow (DF) sample handling and calibration for FAAS has now appeared (94/2922).Three methods of DF implemented by a commer- cially available device were described. In the first the standard solution was delivered from a cam-driven piston pump and merged with diluent which was aspirated from a reservoir by the suction provided by a peristaltic pump running at constant speed downstream of the confluence point. The standard and diluent solutions were merged at flow rates which produced four standards (0 30 71 and 100% of the standard concen- tration). In the second method the manifold was modified so that the method of standard additions could be implemented by the introduction of sample solution from an open reservoir downstream of the standard-diluent confluence point but upstream of the peristaltic pump. This method was not tested in the presence of an interferent but for a 10 ppm Ca standard a bias of about 2% was found.In the third method a system of three cam-driven piston pumps was used to generate a linear concentration gradient between a low and a high standard. Sample was introduced via a fourth cam-driven pump. Solution was withdrawn from the manifold upstream of the merging point of the two standard streams at a flow rate equal to that at which the high standard was added. Efficient mixing was provided by a vibrating reed mixer (see Sperling et al. Anal. Chem. 1991 63 151). For the replicate determination of 10 ppm Ca using standards of 2 and 20 ppm the bias and precision were both 0.5%. Methods 2 and 3 took about 30 s to implement and eliminated the effects of instru- mental drift as the system was constantly recalibrated for each sample. As in previous review periods there is still considerable activity in the development of on-line solid-phase extraction (SPE) procedures.Several papers have been concerned with the Cr"'/Crv1 speciation problem (94/1605 94/C1937 94/C3489). Some evaluative comments on the method of Sperling et al. (Anal. Chem. 1992 64 3103) have been made (94/C1937). In this procedure alumina was used as the solid phase extractant whose charge was controlled by the pH of the buffer carrier stream. The procedure was found to be very sensitive to this pH and thus control of the buffer capacity of the carrier and eluent (and a knowledge of that of the sample) were shown to be important.Interferences from iron sulfate and phosphate were found to be greater than originally reported. It was confirmed that the method was useful for determinations down to 10 ppb of either Cr species in relatively clean water samples of low ionic strength. An HPLC procedure (see section 1.1.5.) has been described for the same analysis (94/3280). In this procedure CrV' could be preconcentrated by changing the composition of the carrier with respect to the tetrabutylammonium acetate concentration. The eluent was a 60/40 (YO v/v) methanol-water solution. The limit of detection for CrV' in drinking water was 0.5 ppb. Workers at Strathclyde have investigated the use of a number of solid phases for this analysis (94/C3489). It was found that Muromac A-1 and quinolin-8-01 immobilized on controlled pore glass (CPG) would preconcentrate Cr"' but not Crvl whereas the Dow resins XFS-415 and XFS-43084 retained CrV' but not Cr"'.A procedure in which the CrV1 was reduced by hydroxylamine prior to retention on Muromac A-1 or on quinolin-8-01 on CPG was applied to the analysis of a number of estuarine and coastal waters. Covalently bound chelating agents have been used in a number of other studies (94/C1940,94/2188,94/3123,94/3156). A DETATA chelating agent bound to fibrous cellulose was used (94/C1940) to preconcentrate Cd by factors of between 50 and 100 while still retaining a throughput of 20 h-'. Fang and Dong determined the same analyte in urine (94/3156) with a procedure involving retention by quinolin-8-01 immobilized on CPG.An enrichment factor of 30 a sampling rate of 60 h-l and a detection limit of 0.3 ppb were obtained. Cysteine immobilized on CPG was used (94/2188) to preconcentrate Cd Cu Co Hg Pb and Zn. Improvements in detection limits by factors ranging from 500 to 2000 were obtained. Acids of various concentrations were used to elute the analytes with the exception of Hg for which thiourea had to be added to the eluent. The effects of the pH of the solution prior to loading and of high concentrations of potentially interfering cations were evaluated. The columns had useful lifetimes of at least 336 h. Gold has been preconcentrated (94/3123) on Cellex-T (cellulose powder with quaternary amine functional groups) followed by elution with 300 pl of 0.1 mol 1-l thiourea in 0.1 mol 1-l HCl solution.Several experimental variables were studied including possible interference effects. It was found that Pt" and Pd" as well as the common ionic constituents of natural waters did not interfere. This paper is an excellent source of information on previous efforts to preconcentrate Au by SPE procedures. A number of sorbent extraction procedures have been described (94/1644 94/3 106 94/3289 94/C3408 95/192) in which the analyte is derivatized as an uncharged chelate complex which is then retained on a non-polar stationary phase. In a high pressure procedure (94/1644) 10 elements were retained as their APDC complexes on a C-18 material followed by elution with methanolic nitric acid (0.01 mol 1-l). The method was applied to the analysis of aluminium and drinking water.A low pressure version of very similar chemistry has been applied (94/3289) to the determination of Cd Cu and Pb in ash soils and sediments. The complexing agent used was either diethylammonium-N,N-diethyldithiocarbamate or ammonium diethyldithiophosphate and elution was with methanol. A number of experimental variables were studied including the effects of pH reagent concentration use of masking agents nature of the eluent and the flow rates for loading and elution. Accurate analyses of some reference 202 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10materials were obtained with the exception of the determi- nation of Cd in the presence of high concentrations of iron. Valcarcel et al. (94/3106) determined Cd by retention of the dithizone complex on activated carbon followed by elution with IBMK.This protocol resulted from a comprehensive study of the possibilities of other chelating agents and eluting solvents as well as a number of experimental variables and a survey of published work on the SPE-FIAS determination of Cd. Preconcentration factors of between 40 and 130 were obtained with a detection limit between 0.3 and 1.3 ppb. The procedure was used to determine Cd accurately in a city waste incineration ash and in some biological reference materials. The same analysis was performed (94/C3408) by retention of the Cd-DDC complex on the interior walls of a PTFE knotted tubular reactor followed by elution with IBMK. About 80% of the analyte was retained at a loading flow rate of 5.2 ml min-'.The interferences from copper and iron were overcome by the addition of thiourea and ascorbic acid-1,lO-phenanthroline respectively. An enhancement factor of 66 and a detection limit of 0.1 ppb were obtained. In the determination of Co in oriental tobacco leaves and an artificial ocean water (95/192) the analyte was retained on Brockmann activity I acid alumina as the 1-nitroso-2-naphthol- 3,6-disulfonate with elution by dilute sodium hydroxide solution. A variety of experimental parameters were studied as well as possible interference effects from other metals. A 97% recovery of 1 ppb from the water sample was obtained. A detection limit of 0.44 ppb was obtained for a 20 min loading time. Alumina has also been used for the retention of As in water samples (94/C3388).Unlike most procedures for the determination of As the method required oxidation of the As"' to AsV. The loading flow rate was 16ml min-' with elution by 8 mol 1-' HC1 at 8 ml min-'. An enrichment factor of 48 was obtained. Some preliminary results on the possibilities of fibrous alumina for the determination of Pb in waters have been reported (95/194) by workers in a laboratory with extensive experience of using powdered alumina. It was found that the new material performed as well as the powder giving a detection limit of 0.7 ppb for a 15 ml sample. The sample was loaded at pH 8 (0.1 mol I-' ammonia) and eluted at pH 0 (1 mol 1-' nitric acid). There is also an interest in the use of immobilized mico- organisms for SPE (94/2878,94/2967).The yeast Saccharomyces cereuisiae immobilized on CPG has been used to preconcen- trate Cd Cu Fe Pb and Zn (94/2878). Again a variety of experimental variables were studied. Under optimized con- ditions enhancement factors of as high as 2000 (for Zn) were obtained. It proved difficult to remove Fe from the material and an eluent consisting of 0.5 mol 1-' perchloric and nitric acids was used. Despite this the lifetime was reported as 400 h provided microbial growth was prevented by storage at 4°C when not in use. Detection limits for all the analytes were below 1 ppb and Cd and Cu were accurately determined in a sediment reference material (BCR 144) with the aid of the standard additions method of calibration. The properties of two immobilized algae (Chlamydonomous reinhartii and Selenestrum capricornutum) for the preconcentration of Ag Cr"' Crv' and Cu have been investigated (94/2967).The algae were immobilized on silanized CPG and the study followed the protocols of previous work (see Elmahadi and Greenway J . Anal. At. Spectrom. 1991,6 643). The two algae were found to have significantly different retention characteristics for Cr"' and Crvl and this was exploited as a method of Cr speciation. The selectivity of each column was controlled by the pH as Chlamydonomous reinhartii preferentially retained CrV' from pH 4.0 phosphate buffer and Selenestrum capricornutum prefe- rentially retained Cr"' from pH 8.5 tris buffer. Chromium(Ix1) was eluted with a solution of thiourea in 0.1 rnol I-' perchloric acid and Crv~ with 0.1 mol 1-' sodium hydroxide solution.There is still a low level of interest in the use of FI liquid- liquid extraction (LLE) procedures directly coupled to FAAS though it is not clear what advantage such a system would have over an appropriately designed SPE system for the same analysis. Nonetheless Chinese workers have reported (95/241) a method for the determination of Mn in hair water and herbal medicine based on extraction with APDC into IBMK. A detection limit of 70 ppb was obtained. A detailed study of the FI extraction of Au and Cu as thiocyanates into IBMK has been described (94/1650). The flow rates were 12.6ml min-' and 0.42 ml min-' for the sample and IBMK respect- ively and segmentation was achieved at a three-way connector with an angle of 120" between each channel.The phase separator was an asymmetric hour-glass shaped glass vessel with an upper chamber volume of 1 ml and a lower chamber volume of 10ml. The mixed phases were introduced at the narrow neck between the chambers. The dimensions of the constriction between the chambers were not given. Detection limits of 2 ppb and 1 ppb for Au and Cu were obtained and the method was used for the accurate determination of these elements in some standard ore samples. In a separate publi- cation (95/220) the same system was used for the determi- nation of Cd in ores down to a detection limit of 0.5 ppb by extraction of the biphenylenebisazoaminoazo-benzene complex into IBMK. A mixed solvent (toluene-xylene 1 4) has been used (94/2250) for the extraction of Cu as the complex with 5,7-dibromo-quinolin-8-01. A T-shaped segmentor was used and phase separation was achieved with a PTFE membrane separator.The detection limit was 0.44 ppb for a preconcen- tration factor of 16 and a throughput of 180 h-'. Yet another system (95/283) for the determination of Ag in geological samples based on extraction with diphenylthiourea into IBMK had a detection limit of 0.54 ppb and a throughput of 30 h-'. A further contribution (94/1821) in the series of indirect methods developed by Valcarcel's group described the determination of amylocaine and bromhexine at concen- trations between 3 and 120ppm by the extraction of the reineckates into 1,2-dichloroethane and determination of the Cr in the organic phase. Kuban has reviewed the use of continuous precipitation techniques in FI analysis (94/2049).A total of 75 references were cited covering applications for FAAS UV-visible spectro- photometry and potentiometry. It was concluded that precipi- tation/dissolution techniques were simple rapid precise and easy to automate requiring lower sample volumes and leading to reduced reagent consumption (in other words all the usual advantages of the FI format). It was observed that crystalline precipitates were harder to handle than gelatinous or curdy material because the former tended to block the filter media and also required longer induction periods necessitating the use of longer reaction coils and/or stopped flow procedures. As the neutral metal complexes used in sorbent extraction procedures (see earlier) are insoluble in water the same reagents can be used in methods of preconcentration and matrix isolation based on precipitation or coprecipitation.Fang and coworkers have described methods for the determination of Ag in geological materials (95/334) and for the determination of Cd Co and Ni in biological materials (95/398). In the former study the Ag was collected by co-precipitation with the iron salt of diethyldithiocarbamate in the presence of 1,lO-phenanthroline and retention of the precipitate on the walls of a knotted tubular reactor without a filter. The precipi- tate was dissolved in IBMK and a detection limit of 0.5 ppb was obtained with an enhancement factor of 26 and a through- put of 62 h-'. A very similar procedure was used in the second study (95/398) with the exception that the analytes were coprecipitated with the APDC complex of iron.Detection limits of 0.3 1 and 3 ppb for Cd Co and Ni respectively were obtained. A cylindrical stainless-steel filter was used (94/2982) Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 203 Rfor the collection of Ni as the 1-nitroso-2-naphthol salt for the analysis of silicate rocks. The sensitivity was considerably increased by precipitation in the presence of hydrogen peroxide and the iron interference was masked with Tiron. The precipi- tate was dissolved in ethanol. A 50-fold preconcentration was obtained from a 10 ml sample with a throughput of 15-20 h-'. Several indirect FI precipitation methods have been described. In a procedure (94/2204) very similar to that based on liquid- liquid extraction (LLE) (see J.Anal. At. Spectrom. 1994 9 213R) papaverine strychnine and cocaine were determined by precipitation with Dragendorff's reagent (Bi14-) The pro- cedure was based on the decrease in the bismuth signal obtained on the introduction of the sample. A number of experimental variables were examined and the final procedure developed applied to the determination of papaverine in a number of pharmaceutical preparations. An indirect method (94/3063) for the determination of cyanide and thiocyanate based on the precipitation and redissolution of the silver salts has been developed by Esmadi et al. and workers in Taiwan have determined sulfate (94/3058) by monitoring the change in the signal due to barium. Also of relevance to this section are the considerable number of papers describing the use of FI techniques for the implemen- tation of a chemical vapour generation procedure (see sec- tion 1.3.) and in conjunction with ETAAS (see section 1.2.2.4.) 1.1.3.4.Solid sample introduction. Further evidence from Spain of the usefulness of the introduction of slurries by FI has been provided (94/3034,94/3035,94/3287). No other work on solid sampling has been reported during this review period. Workers at Murcia (94/3287) have devised a procedure for the determination of Ca Fe Mg Mn and Zn in vegetables. After drying and ashing the residue was ground and for the determination of Fe Mn and Zn was suspended with the aid of ultrasonication in a 10% glycerol 1% hydrochloric acid solution to give a slurry concentration of not more than 1% m/v.For the determination of Ca and Mg the ash was suspended in a 1% hydrochloric acid 1% lanthanum and 0.02% Triton X-100 solution. For the determination of the former group of elements a 150 p1 sample was injected into a water carrier. The concentrations of Ca and Mg were too high for direct introduction and an on-line dilution procedure using a single well-stirred mixing chamber was used (see Lopez Garcia et al. J. Anal. A t . Spectrom. 1992 7 1291). A similar procedure (9413035) was used by these workers for the determi- nation of Ca Fe and Mg in samples with a high silica content (such as diatomaceous earth). Slurries were prepared by grind- ing in an agate ball mill followed by suspension in a 2% hydrochloric acid 1% hydrofluoric acid solution at a concen- tration appropriate for the element.The particle size distri- bution of the ground sample showed that 90% of the particles were below 11 pm in size. The maximum slurry concentration was 1% m/v. Accurate analyses of some geological reference materials were obtained. Workers at Valencia (94/3330) have determined Fe and Mg in cement by a procedure in which the analytes were leached from the solid by sonication in an hydrochloric-nitric acid solution prior to injection into the FI manifold. For the determination of Fe an on-line dilution was effected by a high dispersion manifold containing a single well-stirred mixing chamber. The initial slurry concentration was 0.2% m/v. The same researchers have also developed (94/3034) an on-line microwave digestion procedure for leaching Cu Mn Pb and Zn from vegetables powdered dietary products and sewage sludges A 100 p1 portion of slurry (0.2% in concentrated nitric acid) was injected into a water carrier and merged with a 30% vjv hydrogen peroxide solution in a merging zones manifold. After passage through 100 cm of tubing in a microwave oven the solution was aspirated into the spectrometer by nebulizer suction from a cooled interface cup which allowed the evolved gases to escape.Apart from the determination of Zn in a sewage sludge sample accurate results were obtained. 1.1.3.5. Thermospray introduction. The silica T-tube micro- atomizer device described for HPLC applications in the pre- vious update (see J.Anal. A t . Spectrom. 1994 9 213R) has now been used (95/303) for the determination of Hg Pb and Zn as well as the Cd reported previously. The HPLC effluent was vaporized by a thermospray into an 02-H2 diffusion flame maintained in a heated combustion chamber. A number of operating parameters were optimized and it was found that the optimum conditions for all four elements were similar. Only the Hg response depended on the composition of the mobile phase that for methanol being 6-times greater than that for water. 1.1.3.6. High-pressure nebulization. Berndt and coworkers continue to publish applications of the hydraulic high pressure nebulizer (HHPN) device (94/1605 94,4644 9413280 95,418). In this device the solution is nebulized by pumping at about 2.5 ml min-' through a 20 pm nozzle.This requires a pressure of about 17 MPa and results in nebulization efficiencies of up to 50% with consequent improvements in sensitivity. The system is also more tolerant of high dissolved solids than conventional nebulization. Procedures for the determination of Cr"' and CrV1 incorporating on-line separation with an HPLC column and preconcentration of CrV' were described (94/3280). A very similar experimental set-up was also used for the preconcentration of a number of trace elements from aluminium and in drinking water samples (94/1644). For the aluminium matrix the metals were retained as their APDC complexes on a C-18 solid phase extractant. Detection limits for Au Bi Cd Co Cu Fe Ni Pb T1 and Zn ranged from 0.1 to 1 pg g-'. For trace elements in drinking water (including aluminium) the metals were retained as their quinolin-8-01 complexes.The eluent was methanol in both cases. Improvements in detection limits compared with those for conventional nebulization of between 1 and 2 orders of magni- tude were obtained. The HHPN has also been used as an interface for coupling size-exclusion chromatography with FAAS detection (95/118). The possibilities of the instrumen- tation were demonstrated by the chromatography of ferritin cytochrome C metallothionein and cyanocobalamin with element specific detection. The system was able to handle aqueous solutions as mobile phases with ionic strengths up to 0.1 mol 1-'. The system requires enough pressure from the pump so that after the pressure drop due to the column there is enough pressure to drive the nebulizer.Even at a flow rate of 0.5 ml min-' the nebulization efficiency was sufficent for detection limits of between 5 and 15ng in a 5011 sample volume. A second paper in the series (see J. Anal. At. Spectrom. 1994 9 213R) describing the performance of the single-bore high pressure nebulizer (SBHPN) has been published (Todoli et al. Spectrochim Acta Part B 1993 48 1461). The performance of the device with discrete introduction (200 pl) was studied. Five solvents (water methanol ethanol 2-propanol and 1-butanol) were used as both solvent for the analyte solution (20 ppm Mg) and for the carrier. Two configurations were used; a vertical downward mounting with a Scott-spray chamber and a horizontal mounting with the AA spectrometer's standard spray chamber.As might be expected from the work of Berndt on the HHPN the device performs satisfactorily at low flow rates and with high concentrations of dissolved solids thereby showing potential as an interfacing device for HPLC. As for the previous work the performance of the SBHPN was com- pared with that of a standard Meinhard nebulizer rather than that of a conventional AA nebulizer. The concentration of the 204R Journal of Analytical Atomic Spectrometry August 194'5 Vol. 10test solution used strongly suggests that the SBHPN has significantly poorer sensitivity than a conventional nebulizer. 1.1.4. Sample pre-treatment Although many publications which feature AAS and other atomic spectrometry techniques appear in the original litera- ture because of some novel aspect of the sample pre-treatment procedure only a relatively small number are surveyed in this section. Papers in which the novelty resides in the particular combination of analyte(s) and matrix are not considered relevant to this update.Details of this kind of work may be found in the relevant subject-based updates. The material included in this section has both some novelty about the pre- treatment chemistry and the potential for adaptation to an on-line format. Chinese workers (94/2298) described a co-precipitation pre- concentration procedure for the determination of Cd Cu and Pb in water samples by precipitation of the hydroxides with magnesium hydroxide and re-dissolution in nitric acid. Detection limits of 4 5 and 17 ppb respectively were obtained.For the preconcentration of Cu Fe and Pb from dialysis solutions (94/1665) the APDC complexes were retained on an Amberlite XAD-4 column (60-80 mesh) at 10-15 ml min-'. The analytes were eluted with 1 moll-' nitric acid in acetone. In the determination of Cu Fe and Zn in powdered milk (95/349) the analytes were retained from 6mol 1-' hydro- chloric acid solution as the chloro complexes on an anion exchange column and eluted with dilute acid. Retention on a column of cotton macerated for 24 h with 4 mol 1-' hydro- chloric acid formed the basis of a method for the determination of Cd Cu and Pb (94/1624). River sea and bog water have been analysed (94/2266) for 15 elements collected simul- taneously with trie th ylene tetraminepentaacetate functionali ties immobilized on cellulose.The system had distribution coefficients in the range 104-105ml g-' (pH3-8) and fast exchange kinetics so that even with contact times of less than 1 s collection efficiencies of 88-99.5% were obtained. A column containing silanized diatomite modified with dioctyl tin dichloride was used in the speciation of As in potable and waste waters (94/3329). At pH 2.5-3.5 AdV) was retained whereas As"' was not. Arsenic' was eluted with 2mol 1-1 hydrochloric acid solution. It was found that columns with sorbed AsV could be stored for at least a week without any change thus allowing field sampling with elution and determi- nation in the laboratory at a later time. Polyether foam was used (95/286) to retain Ag and Au from cyanide solutions followed by elution with thiourea solution.A similar procedure using polyurethane foam has been developed (94/3 175) for the determination of Ag Au Cd and T1 in mineral samples. After dissolution in acid the addition of potassium iodide solution and ascorbic acid 50ml of the sample solution was shaken with 200 mg of the foam loaded with IBMK. After separation the metals were eluted with 10 ml of 0.1 mol 1-' hydrochloric acid containing 2% thiourea. The detection limits were 4 40 8 and 85 ng MI-' respectively. Preconcentration in a liquid membrane has been applied (95/135) in the determination of Zn in beverages. The sample was mixed with P507-N,05-liquid paraffin-n-heptane (5 + 3 + 6 + 86) acetate buffer at pH 4.7 and centrifuged after adjusting the ionic strength with sodium chloride solution.The inner phase was de-emulsified by application of a high voltage static electric spark (3000 V for 10 min) diluted and sprayed into an air-C,H flame. The detection limit was 6 ppb. A jotation procedure for the separation of Cu as the sulfide with oleic acid has been devised (95/39). The method was relatively free from interferences from concomitant ions and ionic strength effects. An indirect method for the determination of fluoride has been developed for the analysis of workplace air and waste water (94/2275). The sample solution was passed through a column containing granular lead zirconate-titanate and the leached lead determined at 670.8 nm. Fluoride concentrations between 20 and 20mg 1-' were determined with precisions around 9% RSD.The Pd content of a catalyst has been determined by electrolytic collection on a copper cathode followed by insertion of the cathode into an air-C,H flame (94/2294). 1.1.5. Chromatographic detection As something of a contrast to the previous review period when most of the publications featured GC methods this year's review period is concerned mainly with LC methods. Several overviews of both techniques have appeared concerned with coupling to a variety of spectroscopic techniques including atomic spectrometry (95/126) the use of element specific detection in GC (95/41) the use of micellar or vesicular mobile phases (94/3036) and the use of GC techniques for the determination of organolead compounds (95/1). A variety of coupling devices have been described ranging from the simple connection of the HPLC effluent to the nebulizer of a flame spectrometer with a short length of heat shrink tubing (94/2985) to a thermospray pyrolysis chamber flame-in-tube atomizer (95/303).As described earlier (sec- tion 1.1.3.6.) the operations of two high pressure nebulizer devices have been described (Todoli et al. Spectrochim Acta Part B 1993 48 1461 94/1605 95/118). Only the potential of the device described in the first of these papers was postulated as a result of studies of the FI behaviour of the system with organic solvents. Several size-exclusion chromatographic appli- cations (95/118) were used to illustrate the performance of the hydraulic high pressure nebulizer. Biologically derived species of Co Cu Fe and Zn were determined.The device was also used (94/3280) in the ion-pair chromatographic separation of Cr"' and Cr". A 5 cm column containing 5 pm C-18 packing was used with tetrabutylammonium phosphate-phosphoric acid as the eluent. A pump capable of producing 40 MPa was used which provided enough pressure after the column to drive the nebulizer (about 17 MPa is required for a flow rate of 2.5 ml min-I). Detection limits of 30 and 20 ppb for Cr"' and Crvl respectively were obtained. Gel permeation separation of free and bound species of Ag Cd Cu and Zn in lobster digestive gland extracts followed by either flame or graphite furnace detection has been described (95/98). However with an elution rate of 15 ml min-' the separation was surely not directly coupled to the spectrometer.The thermospray device (95/303) discussed earlier in section 1.1.3.5. was also used for detection following gel permeation separation of metal species from aquatic organisms. In this case Cd Cu and Zn metallo- thioneins from a fresh water mollusc were the target analytes. Post-column chemical vapour generation has been implemented in the determination of As species following LC separation (94/2926 94/3036). In the first of these procedures (94/2926) the species were separated on a Hamilton PRP-X 100 column (with an upstream Waters IC-H anionic cartridge when the cationic species arsenobetaine and arsenocholine were to be determined) by elution with a solution of sodium dihydrogen phosphate and disodium hydrogen phosphate. The eluent was merged with 5% m/v potassium persulfate in 2.5% m/v sodium hydroxide solution (for the cationic species only) and passed through 1.5m of 0.5mm id tubing in a 700 W domestic microwave oven.After cooling in an ice-bath the effluent was merged successively with hydrochloric acid and tetrahydraborate solution before entering a Philips V-tube gas- liquid separator. For a 100 pl injection volume detection limits of between 0.3 and 0.9 ng for the two cationic species and four anionic species (arsenite arsenate dimethylarsinate mono- methylarsonate) were obtained. A vesicular mobile phase has Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 205Rbeen used to separate the anionic species (94/3036) with post- column chemical vapour generation of the volatile derivative directly from the organized medium.Studies of the GC separation of lead alkyls with detection by AAS with a quartz tube atomizer (95/13) and of the tin species liberated as pyrolysis products from solid samples including PVC (94/C1951) have been described. 1.1.6. Plasma atomizers An ultrasonic nebulizer has been used (94/3304) for sample introduction into an MIP as a source for AAS (see J. Anal. At. Spectrom. 1994,9,213R). The resulting aerosol was desolvated with a heating tube and a combination of water-cooled con- denser and concentrated sulfuric acid desiccator. The atom source replaced the burner in a conventional FAA spec- trometer. The characteristic concentration for 12 elements under optimized conditions ranged from 1 (Ag Zn and Cd) to 30 ppb (Ni).Interference effects due to stable compound formation and ionization suppression similar to those of the air-C,H2 flame were observed and the authors concluded that MIP-AAS is similar to FAAS in terms of sensitivity and operating cost. Some fundamental studies on an rf glow discharge atomizer have been reported (94/2216). It was found that for sputtering from oxygen-free Cu the GD plume was constricted by an increase in the argon pressure. It was concluded that the GD source was stable enough to allow sequential AA determinations and depth profiling of metal alloys. Chinese workers have reported on the determination of Cd Cr Cu Fe Mg and Mn by sputtering from a graphite cathode into a glow discharge atomizer operated in a transient mode (94/1628). Marcus (94/2057) has surveyed the use of glow discharge sources for AA and AF.1.2. Electrothermal Atomizers There have been few major developments within the field of electrothermal atomizers during the period covered by this review. With respect to instrumentation the commercial intro- duction of a new simultaneous multi-element ETAAS instru- ment is a major development and is discussed in sections 1.2.5 and 1.4 of this Update. Recently a product overview of ETAAS appeared in Analytical Chemistry (Anal. Chem. 1995,67 51A). Although fairly non-technical it does neatly summarize the development of ETAAS instrumentation in a few pages and concludes that ‘with ETAAS you get a mature technique for a modest investment’. Even though ETAAS is considered a mature technique both the previous Update (94/3317) and the biennial review by Jackson and Mahmood (Anal.Chem. 1994 66,252R) indicated that the technique is still a thriving research area and that there are fresh opinions and ideas appearing in the literature. However apart from these publications there appear to have been no other major reviews published in the field of ETAAS recently. In an inter-laboratory comparison of instruments for the determination of elements in acid digestates of solids Kimbrough and Wakakuwa (Analyst 1994,119,383) appeared to suggest that for environmental analysis ETAAS is no longer a viable technique compared with ICP-AES and even hydride generation AAS is obsolete. However close reading of this paper reveals that at high concentrations ICP-AES is the preferred technique whereas at low concentrations and when matrix interferences are suspected ETAAS is preferred.These conclusions were based on a consideration of the determination of As Cd Mo Se and TI in five soil samples with concen- trations ranging from 5000 to 5 mg kg-’ well above concen- trations that would be considered appropriate for ETAAS. In addition no information was given as to the quality control procedures adopted by the laboratories that produced data for this study which would provide the reassurance that the laboratories were in control before submitting results to the study. For those who have an interest in both the efficiency of detection and efficiency of measurement in atomic spectrometry the paper from Winefordner et al. (see J.Anal. At. Spectrom. 1994 9 131) is recommended reading. This paper discussed how these figures of merit affect the limit of detection and limit of guarantee of purity. The 18 concluding paragraphs concisely assessed every major elemental analytical technique with respect to efficiency of detection and measurement. The possibilities of each technique what should theoretically be achievable and how all the techniques relate to each other were admirably presented. This paper is essential reading for every atomic spectroscopist who has an ‘axe to grind‘ or who holds exaggerated views about the capabilities of his/her own particular technique. 1.2.1. Atomizer design and surface modijication 1.2.1.1. Graphite atomizers. A few reports have been pro- duced during this Update period though generally these were on variations to commercially available atomizer designs rather than anything radically new.Katskov et al. (94/2950 94/2595) discussed the use of Massmann-style graphite tube atomizers containing a graphite Jilter. Within a conventional pyrolytic graphite coated electrographite tube was positioned a tubular graphite insert around which was wrapped 50 mm of graphite thread. The sample was pipetted into the cavity between the tube wall and the tubular insert. When vaporized the atomic vapour diffused through the walls of the filter into the light path of the spectrometer. The performance of the graphite filter atomizer was assessed by measurements with Al Bi Cd and Cu and Bi Cd and Pb in the presence of NaCl and CuC1 matrices.The advantages of such a design were an increase in signal magnitude of the order of 1.6-2.8-fo1dy the ability to increase the sample volume to 100 pl and at the same time reduce the drying period for such a volume to 15s and attainment of a lower level of spectral background and chemi- cal interferences without the need for chemical modification. The graphite filter atomizer was successfully applied to the determination Cd and Pb in whole blood and steel. However some anomalous results discussed in the paper indicated that memory effects were a problem and that the technique needs to be refined. In further work concerning high-temperature metal-uapour elution Kitagawa et al. (95/324) developed an electrothermal atomizer which consisted of a long glassy carbon tube packed with activated charcoal. Solid samples of biological materials were inserted into the atomizer which was maintained at a constant temperature of 2280°C and the atomic vapours of Cu Mg and Mn passed through the activated charcoal with a stream of argon into the light beam of the spectrometer.The advantage of this was the absence of any background absorp- tion and isothermal operation. Streck et al. (94/C3451) considered the use of integrated contact cuvettes (ICC) with either no platform a forked platform or a ring platform for use in a transverse heated graphite atomizer. The system was applied to the determination of Pb in urine and Cr and Se in serum. No indication was given as to which type of ICC-platform combination was employed for these determinations.Wall platform and probe atomization were compared by Cimadevilla et al. (94/2401) for the determination of Cr in biological fluids with and without the use of a mixed chemical modifier of calcium and magnesium nitrates. The best con- ditions were found to be atomization from the wall of pyrolytic graphite coated electrographite tubes and use of the chemical modifier for only water and serum samples. Detection limits 206R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10for peak absorbance measurements were 0.04 0.22 and 0.05 pg 1-1 in water serum and urine respectively. 1.2.1.2. Metal atomizers and metallic coatings. Perez and Sanz-Medel(94/2400) examined the use of the carbide-forming elements molybdenum tantalum tungsten and zirconium for the treatment of pyrolytic graphite platforms and graphite tubes for the determination of Si in biological fluids to prevent the formation of silicon carbide.Tungsten was found to give the best results with a detection limit (3s) of 3.5 pg 1-' and a precision of 2% (n= 10) at a concentration of 90 pg 1-' and with the procedure described it was not found necessary to use any chemical modifiers. Tungsten-metal platforms and atomizers continue to receive attention. Silva et al. (94/3245) used a tungsten coil for the determination of Ba in waters. A purge gas of 10% v/v hydrogen in argon was found to be essential for the atomization of Ba providing a source of hydrogen for the reduction of Ba containing oxygen species. No atomization of Ba was observed when pure argon was used as the purge gas.The lifetime of the tungsten coil depended upon the acidity of the solutions analysed and the presence of organic compounds in the sample matrix. In 0.014mol 1-l nitric acid the lifetime was found to be 400 firings. For sample volumes of 10 pl the interference from Ca above 10 ng was minimized by the use of EDTA and the system was found to tolerate 8000 ng of K lo00 ng of Mg 6000 ng of Na and 10 ng of Sr. An absolute detection limit of 2 pg and a characteristic mass of 3.6 pg were obtained from peak absorbance measurements. Good agreement was found between tungsten coil ETAAS and ICP-AES for a series of water samples. A similar tungsten-coil deoice was used by Barth and Krivan (94/3023) in conjunction with ICP-AES for the determination of Al Cr Fe Mg Mn Ni and Ti in aqueous suspensions of silicon dioxide powder.For the determination of Li in molybdenum oxide Docekal and Krivan (94/3139) used slurry sampling and a transverse heated tungsten atomizer (WETA-82); further details are given in section 1.2.2. A tung- sten-metal atomizer was used by Minamisawa et al. (95/200) for the determination of Cu preconcentrated onto chitin. Chinese workers (94/2281) described the use of a tungsten probe for the determination of Sn in drinking and mineral water. Yizai et al. (94/3104) used a tungsten-foil platform inside a pyrolytic graphite coated electrographite tube in conjunction with a palladium and tartaric acid mixed chemical modifier for the determination of Cd in sea water and a variety of biological and environmental RMs by standardless analysis.These workers reported that the lifetime of the tungsten foil platform 200-300 firings was longer than that of tantalum foil which they used previously. Oimatsu et al. (94/2565) used a tantalum carbide coated graphite atomizer in conjunction with slurry sampling to deter- mine Sn in titanium dioxide. A tantalum platform within a transverse heated graphite atomizer was used by Skroce et al. (95/245) to determine La. This gave better sensitivity than atomization from a pyrolytic graphite surface. The detection limit (3s) was 40 pg 1-1 with a characteristic mass of 220 pg for integrated absorbance measurements. For a recommended method for the determination of A1 in serum French workers (Ann. Biol. Clin. 1992 50 577) some- what surprisingly preferred tantalum coated graphite tubes to graphite tubes.This was claimed to be due to the fact that poor quality graphite tubes can seriously affect the measure- ments. Giordano et al. (95/435) compared the use of either pyrolytic graphite platforms or titanium coated graphite tubes for the determination of Sn in tricyclohexyltin hydroxide; both performed well. Ohta et al. (94/2299) have continued their work on the use of molybdenum-tube atomizers in this case for the determination of K in biological materials. After digestion sample volumes of 1 p1 were taken into the 25 mm long 2 mm i. d. molybdenum foil tube atomizer. A detection limit of 0.12 ng was reported equivalent to 0.12 mg 1-' which appears rather high compared with flame emission measurements for this element.Ammonium molybdate impregnated graphite tubes were used by Lin et al. (94/C3379) for the determination of Ge in herbs plants and sediments. After addition of ammonium molybdate to the 0.3 mol 1-l nitric acid sample solutions the Ge was extracted as the germanomolybdate into butanol. Ammonium molybdate impregnated graphite tubes enhanced the sensitivity. Only limited work on zirconium atomizers has been reported. Yan et al. (94/C3371 95/252) used a zirconium-coated tube for mechanistic studies on the atomization of In and the atomiz- ation of Sn (94/331,94/C3371). This work is discussed in more detail in section 1.2.3. 1.2.2. Sample introduction 1.2.2.1. Slurry sampling. Every other year the numbers of papers and conference reports concerning solid and/or slurry sampling with ETAAS are given a boost by the publication of the papers from the Solid Sampling Symposium held in Germany (Fresenius' J.Anal. Chem. 1993 346). Kurfurst (94/1638) discussed the information that can be obtained from imprecise solid sampling data if these represent the heterogen- eity of the analyte in the sample. In an effort to demonstrate the reliability of slurry sampling Miller-Ihli (94/C1943) dis- cussed a current international collaborative study. The first phase focused on the determination of Cr and Pb in sediment materials. No doubt the results from such a study will go a long way to improving the reputation of slurry sampling ETAAS as a routine analytical procedure. Dobrowolski and Mierzwa (94/2580) considered some of the analytical problems associated with slurry sampling for the determination of trace elements in plant materials.They compared the effects of slurry composition and mechanical and ultrasonic slurry preparation. The use of 5% nitric acid as a solvent and ultrasonic mixing improved the stability of the slurries. Results for CRMs indicated that the slurry method was accurate and comparable to a conventional wet-ashing procedure. The conference report from Miller-Ihli considering the influence of slurry preparation on accuracy was discussed last year (see J. Anal. At. Spectrom. l994,9,213R) and has now been published (95/300). Ultrasonic slurry sampling was applied by Bendicho and Sancho (94/2886) to the determination of Se in wheat flour.A mixed chemical modifier of palladium and magnesium nitrates was used along with a transverse heated atomizer. Good agreement with the certified value for NIST SRM 1567a Wheat Flour was obtained and recoveries on five commercial wheat flour samples were in the range 92-96% with a calibration established against aqueous solutions. The repeatability of the method was 8.2% with a 5% m/v slurry (n= 10) and the detection limit (3s) was 0.06 pg g-'. The method overcame the need for acid digestion or ashing of the samples with the attendant risk of loss of Se. Krivan's research group from the University of Ulm con- tinued their investigations into the suitability of slurry sampling for the determination of trace elements in refractory materials. From this group Hauptkorn et a!.(94/2955) applied slurry sampling into a transverse heated atomizer equipped with an automated ultrasonic mixing accessory to the determination of Si in titanium dioxide and zirconium dioxide powders. Calcium nitrate was found to be the best chemical modifier because with magnesium nitrate (generally recommended for Si) poor signals were obtained from the titanium dioxide matrix. The retention of calcium and zirconium in the atomizer was examined with the aid of 47Ca and 97Zr as radiotracers. Even though the retention of zirconium increased linearly with the number of determinations this did not have any effect on the Si signal and up to 300 firings could be achieved before Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 207 Rany signal degradation occurred.Calibration was performed by the methods of analyte additions using aqueous standards. The limits of detection (3s) were 7 and 2pg g-' in titanium and zirconium dioxide respectively. Good agreement with results from d.c. AES slurry ICP-AES and ICP-AES after sample digestion was obtained. However comparison of the results obtained allowed an estimation of the heterogeneity from the ETAAS results due to the larger standard deviations found. Hauptkorn and Krivan (94/3363) determined Si in boron nitride by slurry sampling with a magnesium nitrate chemical modifier. Calibration was established either by the method of analyte additions or with a calibration curve prepared from aqueous solutions. For the determination of 20 pg g-' of Si the RSDs were 8.3 and 10.5% for the method of analyte additions or a calibration curve respectively.The detection limit (3s) was 3 pg g-' and good agreement was obtained with results from XRF spectrometry. Docekal and Krivan (94/3 139) have continued their work on slurry sampling for the determination of various elements in molybdenum oxide (see J. Anal. At. Spectrom. 1994 9 213R). In previous work poor detection limits were obtained for Li. This has now been improved by the use of a transverse heated tungsten atomizer (WETA-82) and the detection limit (3s) was improved to 2 ng g-' compared with 40 ng g-' for a graphite atomizer. These same workers (94/1612) described a procedure to remove the molybdenum matrix from a graphite atomizer after such analyses using a purge gas of CF4 after the atomizer clean-out step.The procedure described restored the signals for Co Cr Cu Fe Mg Mn and Ni to their original values and extended the analytical lifetime of the graphite tube to 200-300 firings. Oimatsu et al. (94/2565) used a tantalum carbide coated graphite atomizer in conjunction with slurry sampling to determine Sn in titanium dioxide. The powdered sample (0.5 g) was mixed ultrasonically with 2.5 ml of 0.1% m/v sodium hexametaphosphate and diluted to 50ml with water. After shaking for 30 min aliquots of the slurry were taken for analysis along with lop1 of 20% m/v ascorbic acid as the chemical modifier. A detection limit of 0.15 ng was reported (though no indication was given of the sample volume) and the method was claimed to eliminate most of the interferences from the matrix and produced results in agreement with those obtained by hydride generation AAS or ICP-MS after acid digestion.Lopez Garcia et al. (94/3286) have continued their work on slurry sampling ETAAS for the determination of Cd Mn and Zn in high silica content diatomaceous earth. The same procedure as that described previously (see J. Anal. At. Spectrom. l994,9,213R) was employed. Good agreement with results obtained by acid dissolution of the samples was found but the precision was improved by slurry sampling. For 0.1 pgg-' of Cd 36pg g-' of Mn and 9 pg g-' of Zn precisions (n=7) of 7.8 2.8 and 3.3% RSD were obtained respectively. Chinese workers (95/457) determined Pb in soil by suspending the powdered sample after passage through an 180-mesh sieve in 0.2% agar solution.Russian workers (95/445) determined Cd and Pb in soil suspensions after ultrasonic mixing with 1% v/v nitric acid. The determination of Pb in marine sediments by Bermejo-Barrera et al. and discussed last year (see J. Anal. At. Spectrom. 1994 9 213R) has now been published (94/2956). These workers (94/C3465) applied a similar procedure for the determination of As"' and AsV species in marine sediment by slurry sampling ETAAS. The As'" was determined by a prior extraction method using NaDDC and 4-methylpentan-2-one before injection into the graphite atomizer using palladium as the chemical modifier. The AsV was determined by difference from the total As determined by slurry sampling and As"'. The precision and accuracy of the method were studied using PACS-1 (Marine Sediment) RM.To avoid the time-consuming digestion pro- cedure for the determination of As in plant materials Kukier et al. (95/373) examined the use of automated slurry sampling into a transverse heated graphite atomizer. The results were in agreement with those from hydride generation after a nitric acid-perchloric acid digestion. These workers concluded that this illustrated that a slurry sampling ETAAS procedure could eliminate the time and labour involved in the plant digestion step. For the determination of Cu in glass samples Morita et al. (94/2563) mixed 1-30 mg samples of powdered glass with 5 ml of 10% glycerine solution and applied ultrasonic agitation for 30 s. From this homogeneous suspension 10 pl aliquots were taken into the graphite atomizer along with 10 pl of 5% m/v ammonium fluoride as the chemical modifier.The precision (n=6) for 11.5 pg g-' of Cu was 2.4%. Chinese workers (94/3096) developed a magnetic auto- stirrer which was designed to be mounted on the sample tray of a Perkin-Elmer AS-40 autosampler. The system was applied to the analysis of plant food coal fly ash and geological samples. An underwater spark system was applied by Bendicho (94/3339) to produce colloidal suspensions from electrolytic iron samples for the determination of Cr Cu and Mn impurit- ies. The system was operated at 75 W for 30-60 min and the amount of sample dispersed found by weighing the rods before and after the spark procedure. The colloidal suspension was analysed by ETAAS. The procedure was evaluated by examin- ation of NIST SRM 665 Electrolytic Iron and results in agreement with the certified values were obtained.Japanese workers (94/3306) determined Pd by adsorption onto an anion-exchange resin containing an immobilized sulfonic acid derivative of dithizone at pH 1-10 for 1-15 min. The Pd-containing resin was suspended in water and the suspension injected into the graphite atomizer. The detection limit for Pd" was 5 pg 1-' and the procedure was applied to the determination of Pd" in natural waters. The use of micro-organisms to preconcentrate elements fol- lowed by slurry sampling of the residue has been examined by Robles et al. for the determination of Au (94/2189) Be (94/3247 94/C3498) and Cd (94/C3436). Preconcentration with Escherichia coli or Pseudomonas putida either living (batch) or dead (immobilization) was examined.The optimum procedure for all elements appeared to be batch preconcentration with E . coli at a pH of 6-9 followed by centrifugation and suspension of the bacterial mass in 3.5 moll-' nitric acid and introduction of the slurry into a graphite atomizer equipped with a platform. For 0.1 pg 1-' of Au and 10 pg 1-' of Be the precisions (n=9) were 7 and 3% respectively and detection limits (3s) of 0.004 and 0.05 pg 1-' were found respectively. For Cd a detection limit (3s) of 0.04 pg 1-' was found. For Au and Be little interference from major and minor elements of environ- mental interest was found. In spite of this the method appears to have little advantage over other procedures as the precon- centration is subject to so many variables such as pH solution volume to bacterial mass ratio the bacterial mass used in preconcentration and interferences by elements such as Ag Ca and Fe.For the determination of B in cell suspensions Papaspytou et al. (94/3026) used magnetic stirring of the cell suspensions in the autosampler cups. To prevent clogging of the autosampler injection capillary a slightly larger capillary was employed. This method was an improvement over other procedures because it eliminated a time-consuming digestion procedure and any risk of losing B. The method was developed in conjunction with studies concerned with boron neutron capture therapy for tumour treatment. Calibration for B was by the method of analyte additions using boric acid solutions and the between-batch precision (n = 6) for 0.57 pg mg-' of protein was found to be 5.7%.The limit of detection (3s) was 208R Journal of Analytical Atomic Spectrometry August 1995 Vol. 100.05 mg 1-' of cell suspension. This compared well with the detection limits achieved by DCP-AES and ICP-AES. 1.2.2.2. Solid sampling. In another example of turning one of the disadvantages of solid sampling into an advantage Pauwels et al. (94/1631) determined the homogeneity of Cd in four polyethylene CRMs with nominal Cd concentrations in the range 40-400 mg kg-' with solid sampling ETAAS. From each of the four CRMs 60 analyses were performed with sample masses ranging from 60 to 250pg. Leuker et al. (94/258 1 94/2582) applied solid sampling Zeeman ETAAS to assess the distribution of Cd and Pb in mallard (94/2581) and equine (94/2582) livers. With respect to the mallard livers Cd in the concentration range 0.09-2.4 ng g-' was found to have an increased degree of heterogeneity though for Pb the variance due to heterogeneity was distinctly lower than the residual experimental error.For equine livers the analysis of variance showed a negligibly low influence of heterogeneity on the results. In both papers the importance of a proper sampling strategy for solid sampling procedures was emphasized. In general these workers recommended the analysis of at least six microsamples from different parts of a liver in order to reduce the influence of minor heterogeneity. Using such a strategy results by solid sampling agreed well with those obtained by conventional sample decomposition procedures after sample homogenization. The application of solid sampling to the determination of Si in gold discussed last year (see J.Anal. At. Spectrom. 1994 9 213R) has now been published (94/2953). Hinds and Kogan (94/2953) compared solid sampling ETAAS with aqueous calibration solution-based ETAAS and ICP-AES procedures with matrix matched calibration solutions and spark ablation ICP-AES. The first three procedures gave comparable results though solid sampling ETAAS was more error prone. However detection limits were of the order of 3 pg g-' for all the four procedures. While spark ablation ICP-AES is somewhat more sensitive and convenient the absence of gold reference mate- rials for calibration which up till recently have not been available limits its use.Russian workers (94/3 147) applied solid sampling ETAAS to the determination of Al Bi Cd Co Cu Fe Mn Pb Si and Sn in high-purity tantalum pentoxide. The direct solid introduction for the determination of Ag Cd Cu and V in fly ash using pressure regulated ETAAS discussed previously (see J. Anal. At. Spectrom. 1993 8 197R) has now been published (94/2579). Calibration for Cd and Cu was against a calibration curve established with aqueous solutions though for V the method of analyte additions had to be used owing to analyte expulsion by the fly-ash matrix. The pro- cedures were verified by analysis of NIST SRM 1633a Coal Fly Ash and good agreement was obtained with the certified values.1.2.2.3. Gas sampling. Though not directly concerned with solid or slurry sampling work continues in a few groups on the direct sampling of air into a graphite atomizer for the purposes of assessing airborne contamination due to particu- late matter. Sneddon (92/C3369) discussed the use of a single- stage impacter connected to a graphite atomizer. The air or atmosphere was pulled through the atomizer by vacuum and collected directly on the graphite surface. Sampling for several minutes followed by the analysis stage of a few minutes allowed a near real-time determination of metals in air. This was applied to the determination of Cd Cu Hg and Pb in a laboratory atmosphere. Similarly Liidke et al. (94/3 105) drew air through the wall of a porous graphite tube to collect particulates on the inner surface.This tube was then used as the graphite electrothermal atomizer in furnace atomization non-thermal excitation spectrometry (FANES). Allied with the use of an Cchelle polychromator simultaneous multi-element determinations were possible. Detection limits ranged from 0.1 to 1 ng m-3 for Ca Cd Cr Cu Fe Ni Pb and Sr. Flow rates through the graphite tubes ranged from 140 to 200dm3 h-' and air volumes of between 1.1 andl.5 m3 were sampled. Given that Ni had the worse detection limit a minimum sampling time of 2 h was required to achieve a reliable determination at eight times the detection limit. There was satisfactory agree- ment with results obtained previously by established methods. Baaske et al. (94/3246) described a novel procedure for the determination of trace amounts of Fe in gaseous hydrogen chloride with a modified ETAAS instrument.Pyrolytic graphite coated electrographite tubes designed for use with a probe atomizer were employed. This allowed a gas sample to be injected into the atomizer via the probe slot in the tube using a graphite capillary attached to a gas-tight syringe. Gas sample volumes of 0.1 ml were injected into the atomizer with no internal gas flowing at a temperature of 1100°C followed immediately by atomization at 2300°C. The use of integrated absorbance measurements allowed calibration by means of standards prepared in hydrochloric acid purified by sub-boiling distillation. A detection limit (3s) of 0.7 ngml-' was found and the Fe content of hydrogen chloride calculated to be 50.1 ng ml-' with a precision of 4% ( n = 6 ) .1.2.2.4. Coupled techniques and preconcentration. For the coupling of FI techniques to ETAAS the group of Welz and Sperling have been very active. These workers have applied automatic on-line column preconcentration and separation to ETAAS (94/1636) for the determination of Cd and Pb in high- purity reagents. Following retention on a microcolumn con- taining 9 pl of solid sorbent and the introduction of air to remove the wash solution the analytes were eluted quantitat- ively with 80 pl of methanol. The total eluate volume was transferred into the graphite atomizer which was pre-heated to 80°C using a flow rate of 0.08 ml min-' which allowed the partial evaporation of the solvent during eluate introduction.The enrichment factors were 62 and 64 for Cd and Pb respectively compared with the direct introduction of 30 pl of an aqueous solution. The sample throughput was 13 h-' for a sample loading time of 60 s and the detection limits (3s) were 0.7 and 4.5 ng 1-' for Cd and Pb respectively. The precision of the procedure in the optimum working range was approximately 3% (n = 6 ) . A number of high-purity and analyt- ical-grade reagents were analysed and recoveries were of the order of 97-104%. Wang et al. (94/3073) described the determination of ultra- trace amounts of Cd and Cu in sea-water with FI microcolumn preconcentration coupled with ETAAS. These workers used a manual flow injection procedure followed by collection of 80 pl of ethanol eluate into an autosampler cup from which it was loaded into the furnace in two 40 pl aliquots. It was claimed that a new type of C18 column loaded with NaDDC was used to extract Cd and Cu from sea-water as DDC chelates however the procedure seems very similar to that employed by Sperling et al.(J. Anal. At. Spectrom. 1991,6,295). Although the procedure required only small volumes of sea-water 400 and 600 pl for Cd and Cu respectively compared with 3000 pl taken by Sperling et al. lower preconcentration factors of 10- and 15-fold for Cd and Cu respectively were found. Detection limits (3s) for the preconcentration from aqueous solutions were 0.004 and 0.024 pg 1-' for Cd and Cu respectively. Results for the determination of Cd and Cu in CASS-2 Nearshore Sea Water RM showed no significant difference between the certified values and experimental results.Liu and Huang (94/1616) also determined Cd and Cu in sea-water by automatic on-line preconcentration in the autosampler capil- lary tip. A silica gel CI8 microcolumn was mounted near the tip of the autosampler capillary. The preconcentration pro- cedure was performed by using the pumps of the autosampler Journal of Analytical Atomic Spectrometry August 1995 VoE. 10 209 R(a Perkin-Elmer AS-40) and a four-way valve controlled by a programmable controller. The chelating agent APDC was added to the sample solutions and only 0.2-2ml of sample were required to determine Cd and Cu in sea-water. Detection limits were found to be 1.26 and 6.5ng I-' for Cd and Cu respectively.Heng-bin et al. (94/2 198) applied %-atomizer trapping' within a graphite atomizer coated with palladium to determine As in fractions eluted from a Dionex CASl bifunctional column to determine various As-containing species in lake and river water. From 0.1 ml samples and using a mobile phase of 5 mmol 1-l ammonium dihydrogen phosphate at pH 5.8 the first 2 ml of eluate were discarded and then 40 fractions of ten drops each were collected and analysed. Recoveries were >96% and detection limits for the different species ranged from 1.6 to 1.9 pg 1-' Other Chinese workers (94/2411) applied 'in-atomizer trapping' with an FI chemical vapour generator coupled to an electrothermal graphite atomizer to determine Hg in environmental samples. For the determination of Se in fruit juices Arruda et al.(94/2981) applied an automatic FI method coupled with ETAAS. The flow manifold used which was coupled to the autosampler cup enabled dilution of the slurry addition of a chemical modifier and the determination of Se in the filtered liquid phase. In fruit and tomato juices diluted ten-fold Se was successfully determined using the method of analyte additions with a detection limit (3s) of 5 pg I-'. Kuo et al. (94/2697) increased the sample loading within a graphite atomizer by automatically pipetting and drying nine multiple 90 p1 aliquots of the samples for the determination of Co Cr Cu Fe Mn and Ni. Detection limits were 9 8 4 6 3 and 9 ng 1-' for Co Cr Cu Fe Mn and Ni respectively. While these are certainly impressive detection limits this performance was achieved at the cost of 21.8 min being required for a single measurement.The use of a hydraulic high-pressure nebulizer sample intro- duction system for ETAAS was discussed previously (see J. Anal. At. Spectrom. 1992 7 215R) but has now been published by Berndt and Schaldach (94/2215). The samples were introduced into an aerosol deposition module equipped with a hydraulic high-pressure nebulizer whereby the aerosol was deposited within the graphite atomizer tube maintained at a temperature of 140 "C. Using such a high-pressure system the efficiency of aerosol transport was increased with maximum aerosol yields of the order of 60%. As a high-pressure flow system is required for this type of nebulization on-line matrix separation and preconcentration procedures directly linked to ETAAS are possible.The technique was applied to the determi- nation of Au Co Cu and Pb complexed with APDC within an aluminium chloride matrix. Detection limits of 0.019 0.17 0.021 and 0.05 pg g-' were obtained for Au Co Cu and Pb respectively. Chinese workers (95/282) also appear to have examined pneumatic nebulization for sample introduction for ETAAS though few details were given in the abstract. 1.2.2.5. Electrodeposition. There is still a low level of interest in the use of electrodeposition for separation of analytes from appropriate matrix solutions. Matousek and Powell (94/3037) described a procedure whereby a 50 pl sample volume was pipetted into the V-shaped well of a pyrolytic graphite platform. The solution was electrolysed at an uncontrolled potential of 4-6 V with the platform as the cathode and a platinum wire of 0.5 mm diameter positioned 0.63 mm from the platform as the anode.The rate of removal of Pb from the solution was monitored by withdrawing pl samples and analysed using differential pulse anodic-stripping voltammetry. After removal of deposited Pb with 3% v/v nitric acid and drying the platform was ready for the next sample. Complete deposition of the Pb was achieved in 4 min at 6 V for concentrations of Pb of up to 500yg 1-'. This rapid rate of deposition was considered to be due to the convective stirring caused by gas evolution. A single platform could be used for up to 50 electrolyses. Sadly even from the original paper it is difficult to work out exactly what is going on in this process.Presumably the platform is present within the atomizer after electrodeposition the matrix containing solution must be removed from within the atomizer leaving the electrodeposited Pb on the platform. If the Pb is then determined by atomiz- ation why is it necessary to remove the Pb by washing the platform? These workers appear to have developed a fully automated system for loading the samples electrolysis electro- lyte removal washing and pre-treatment of the deposit prior to ETAAS (94/3037) and for which a patent has been applied (94/3083). The other worker active in the field of electrodeposition is Beinrohr (see J. Anal. At. Spectrom. 1992 7 215R and 1994 9 213R) who has taken a different approach to developing a flow-through electrolytic cell.In the most recent work Beinrohr et al. (94/1643) determined Pt in tobacco beans slag and dust samples after a digestion procedure. Platinum from the sample solutions was deposited at -0.9 to 1.2 V uersus an SCE in a flow-through system incorporating a three-electrode flow-through cell with a graphite counter and Ag-AgC1 refer- ence electrodes. The working electrode was reticulated vitreous carbon packed into a pyrolytic graphite coated electrographite tube. The reticulated vitreous carbon filled the tube and had a hole bored through to allow the light beam to pass through the tube for ETAAS measurements. During the preconcen- tration step this hole was plugged with a glass rod. After electrodeposition the tube was washed and placed into the atomizer and an atomization temperature of 2700 "C applied.For a 2 g sample digested and diluted to 25 ml and with 5 ml taken for electrodeposition the detection limit was found to be 1 ng g-'. Samples containing Fe"' required reduction with ascorbic acid before the deposition step. The results obtained with this procedure agreed with those obtained by a micro- column preconcentration procedure followed by ETAAS. However it has to be said that this cannot be the fastest procedure ever developed and remains a manual procedure. Pannier et al. (94/1690) developed a method to determine butyltin species by ion chromatography linked on-line with ETAAS. Few details were given as to how this was achieved though mono- di- and tributyltin could be determined in a single experiment with detection limits of 0.5 1.1 and 0.8 ng of Sn respectively.Koelbl et al. (95/101) discussed the use of computerized data treatment for an HPLC-ETAAS system for the identification and quantification of trace element compounds. This is needed as the quantification of the dis- continuous signals from an ETAAS instrument defining a chromatography band is difficult. 1.2.3. Fundamental processes Judging by the absolute lack of reports considering A1 'spikes' and the reduction ofoxides by carbides (ROC) theory it would appear that the ROC theory or mechanism has been discarded. However that does not mean that A1 'spikes' have been forgotten! The main participants in the discussion now have new theories to account for the phenomenon. L'vov (95/244) commented that the condensation scheme developed by himself in conjunction with Frech (see J. Anal.At. Spectrom. 1994 9 213R) can be applied to interpret the observations of Gilmutdinov et al. (J. Anal. At. Spectrom. 1992 7 675) and Chakrabarti et al. (Anal. Chem. 1993 65 716) in particular the doughnut structure of the cloud produced by evaporation of pg amounts of A1203. L'vov considered that the doughnut phenomenon correlated well with the condensation concept and that condensation of either metallic A1 or A1203 is 2 t 0 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10occurring at the cooler tube ends and also around the tube injection hole. L’vov questioned whether the partial pressure of oxygen in the tube is comparable to that of A1,O which is necessary for the reaction to A1203 to proceed hence it would appear that condensation of metallic particles is favoured.A series of papers has appeared from Gilmutdinov’s group concerned with the application of shadow spectral Jilming to investigate the non-steady-state structure of atomic and mol- ecular absorbing layers in ETAAS. These reports concerned the atomization of Cd Hg and Zn (94/3040); Cu Fe and Mn (94/3146); Ga and In (95/255); Bi Ge and T1(95/256); and A1 (95/260). While these are all in Russian it is hoped that English translations appear soon. It is clear that shadow spectral filming and the work of Gilmutdinov’s group has had a major impact on our understanding of what is happening inside a graphite electrothermal atomizer. While it is still not fully understood there is a better appreciation of the atomic and molecular distributions than there was 4-5 years ago in at least that they are complex and often element specific. The cross-sectional distribution of Cd Hg and Zn (94/3040) under interrupted gas flow conditions at the atomization stage showed a weak inhomogeneity with a maximum near the sample in the atomizer and the structure appeared to be mainly conditioned by physical factors.The longitudinal non- uniformity of the absorbing layer in the graphite atomizer could be increased by gas expulsion from the dosing hole. For Cd and Zn an anisotropic distribution and a cascade mechan- ism in their transport was observed. In the case of Cu Fe and Mn (94/3146) these were atomized from a graphite platform in a pyrolytic graphite coated electrographite tube.The shadow spectral filming results indicated a significant non-uniformity of the absorbing layer which was attributed to adsorption of the atoms on the furnace walls the diffusion transfer processes and non-uniformity of the distribution of the sample residue. The results for the atomization of Ga and In (95/255) showed a non-uniform distribution with respect to both the cross- sectional and longitudinal sections of the atomizer. The com- pounds were localized in the central part of the atomizer over the platform and disappeared at the hotter walls. The absorp- tion bands observed with maxima at 255 and 295nm upon the atomization of gallium and indium nitrates were assigned to gaseous Ga,O and In,O respectively.The distribution of free In and Ga atoms differs from that of their compounds. These enter the gas phase not from the platform but from the upper wall of the atomizer (inverse atomization). This is due to sample evaporation as M 2 0 molecules which are dissociated or reduced to metal atoms on the hotter graphite walls of the atomizer. In the case of atomization of Ga and In the effects of chemical reactions between the vapour and the walls of the atomizer on the formation of absorbing layers are stronger than that of diffusion and convective mass-transfer processes which are common to all of the elements. Atom propagation from the centre to the ends of the atomizer proceeds through the cascade mechanism because of the atomizers relatively low rate of heating and strong longitudinal non-homogeneous temperature distribution.The differences in the atomic and molecular distributions were examined for the atomization of Si Ge and TI (95/256) by shadow spectralfilming with the sample deposited either on the atomizer wall or platform. With deposition on the atomizer wall the atomic distribution decreases near the wall with platform atomization the effect of inverse atomization is seen atoms enter the gas phase not from the platform but from the opposite atomizer wall. The nitrates of Bi Ge and T1 evaporate as volatile sub-oxides which are reduced on the graphite atomizer wall and re-enter the atomizer gas phase as free atoms. Atoms diffusing within the atomizer volume are deposited on the colder platform and re-enter the atomizer gas phase as the platform warms up.Thus the atomic and molecu- lar vapour densities of these elements increase and decrease in the furnace cross-section when absorbing layers of these elements are formed. Atom propagation from the centre of the atomizer to its ends proceeds progressively by the cascade mechanism as a result of the non-isothermal temperature distribution within the atomizer. The structure of the absorp- tion layer becomes uniform at the end of sample evaporation. In the final report covered in this Update period Gilmutdinov et al. (95/260) turned their attention once more to study of the atomization of A1 by shadow spectralJilming. Aluminium was injected as the nitrate sulfate or metal. The structures of the atomic and molecular layers were significantly inhomogeneous with respect to both the atomizer cross- and longitudinal-sections.Free atoms were found to be localized near the atomizer walls and under the platform. By contrast the A1 compounds were located along the axis of the central part of the atomizer and found to disappear near the walls. The absorption band with a peak at 255 nm was assigned to gaseous A120 molecules. The structural heterogeneity of the atomic layer and of the molecular layer of A1 sub-oxides are caused by oxidation reactions between A1 compounds and oxygen and by the reduction of gaseous oxides on the graphite walls of the atomizer. During atomization of pg amounts of A1 in the gas phase inside the graphite atomizer a cloud of finely divided A1203 forms as a result of vapour oxidation with air entering the atomizer through the injection hole.It would appear that reactions involving oxygen-containing molecules have a major effect on the atomization of Al. The use of cross-beam sampling with ETV-MS to investigate the decomposition of metallic nitrates to oxides was discussed last year (see J. Anal. At. Spectrom. 1994 9 213R) and has now been published (94/2949). It is clear that the nature of the surface from which atomiz- ation takes place has a major effect on the atomization process. Up to now most workers have concentrated on the gas phase though these investigations have resulted in a general recog- nition of surfaces as principal players in the atomization processes but few have actually examined the surfaces involved. This is not because the surface was being ignored but more a case of the severe difficulties in trying to investigate the surface under the conditions present in an electrothermal atomizer.Styris et al. (94/C3420) discussed some of the experimental approaches that can be used and presented recent work on the elucidation of electrothermal atomizer mechanisms by applying extended X-ray absorption fine structure spec- troscopy in particular to the selenium-palladium mixture. Results were compared with MS data. Chinese workers (94/1825) described a model which accounted for the dissi- pation process of the atomic vapour and for the interaction between the elements determined and the wall of the graphite atomizer tube. Katskov et al. (94/2932) reviewed the results obtained with a two-step atomizer and a scanning spectrometer to investigate the processes of sample evaporation and atomization in ETAAS.The apparatus consisted of a tube furnace held at a constant temperature which was used for vapour decomposition. Sample vapours enter the furnace from a vaporizer situated next to the furnace via a very low stream of carrier gas or by diffusion. To enable a stationary absorbing layer to be formed within the furnace the vaporizer temperature was controlled by means of an automatic system using the analytical signal feedback for determining the vapour flux. Absorption was measured by one of two spectral channels of a spectrometer at a set wavelength. The other channel scanned the spectrum over a range of wavelengths. The evaporation characteristics of Ag Au Bi Cd Co Cu Ga Ge Pb Sn Te T1 and Zn in the presence of halide and oxygen containing atmospheres and Ag Bi Cd Ga In Mn Pb Sb Sn Te T1 and Zn in both inert and oxygen containing atmospheres were presented.An Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 21 1 Rexplanation of the results obtained based on Langmuir's theory of evaporation was developed for the experimental conditions of ETAAS. The paper is recommended reading as it presents an alternative experimental approach and contains a great deal of information. The conference report from Tittarelli et al. and discussed last year (see J. Anal. At. Spectrom. 1994 9 213R) concerning the vaporization of Ge and Si as molecular species within electrothermal atomizers has now been published (94/2952).Chinese workers (95/202) investigated the atomization of Ge from a graphite probe surface as germanium fluoride and sodium germanate using XRD X-ray photoelectron and Auger electron spectrometry. The following mechanism for the forma- tion of Ge atoms was proposed. Both GeF and Na3Ge03 decompose first to GeO and then to GeO followed by thermal dissociation of GeO to form free atoms of Ge at a temperature greater than or equal to 2400 K. The decomposition route from GeO to GeO tends to agree with that found by Doidge and McAllister (see J. Anal. At. Spectrom. 1994 9 213R) who used ETV-MS and thermochemical equilibrium calculations which was discussed last year. Wiltshire et al. (95/321) investigated the atomization of B from a total pyrolytic graphite tube coated with either tungsten carbide or lanthanum carbide.These coatings increased the optimum pyrolysis temperature of B from 850 to >22OO"C. Addition of a calcium-magnesium chemical modifier increased the pyrolysis temperature to 1200 "C whereas a titanium- ascorbic acid modifier had no significant effect. The low- temperature loss of B without a chemical modifier was investigated using dynamic SIMS which confirmed that vapor- ization of B species occurs above 900°C. Atomic emission signals were obtained at < 800 "C by hollow-cathode FANES. Molecular dissociation and excitation of B atoms apparently occurred through a one-step collisional process. The results suggested that the atomization of B in ETAAS was likely to occur through molecular dissociation rather than solely by sublimation of B.The chemical modifiers probably prevented low-temperature dissociative desorption of B,O occurring at active carbon sites and so increased the optimum pyrolysis temperature to >85O"C. The poor detection limit for B in ETAAS was due to the inefficient thermal dissociation of the B-containing species (probably oxides and carbides) produced by dissociative desorption of B203. In addition once formed B atoms apparently undergo a series of condensation-vaporiz- ation steps which caused a persistent plateau in the tail of the AA signal and resulted in severe memory effects. Doner and Akman (94/2933) investigated the effect of cobalt chloride on the atomization of Zn with the use of dual cavity graphite platforms to allow differentiation between gas-phase and condensed-phase interferences.When the analyte and interferent were separated on the dual cavity platform con- densed-phase interferences disappeared whereas gas-phase interferences continued to affect the sensitivity of the analyte. From this study the dominant interference mechanism appeared to be the formation of volatile zinc chloride upon reaction between the analyte and interferent at low tempera- tures which was expelled from the atomizer by the gaseous hydrogen chloride generated in large amounts during the thermal hydrolysis of cobalt chloride hexahydrate. In addition a condensed-phase gas-phase reaction between the gaseous hydrogen chloride and the analyte could also cause the forma- tion of zinc chloride.Although gas-phase reactions and/or expulsion mechanisms would seem plausible their effects did not seem to be very pronounced. Russian workers (94/2277) reviewed (55 refs.) the problems of mathematical simulation of electrothermal atomization in AAS. They proposed a method for an equilibrium thermo- dynamic simulation based on dividing a non-equilibrium dynamic system into successive local quasi-equilibrium zones. The method was applied to the description of the pyrolysis and atomization of more than 40 elements in graphite tube and tungsten spiral atomizers. Zheng (95/277) determined the atomization eficiency of the Hitachi GA-3 atomizer for Ag Cd Cr Ge and In by a method based on the measurement of residence time of analyte atoms peak absorbance and integrated absorbance.The atomization efficiencies for Ag and Cd appeared to be stable at low temperatures whereas those for Cr Ge and In reached a stable value at higher temperatures. For In the efficiency was increased in the presence of palladium and the ammonium salt of EDTA as chemical modifiers. The method proposed by Yan et al. and discussed last year (see J. Anal. At. Spectrom. 1994,9 213R) for the determination of the kinetic order and activation energy from a single absorbance profile has been applied by Ni and Yan (94/C3371) to the atomization of In Pb and Sn and in detail by Yan et a!. (95/252) to the atomization of In and by Quan et al. (95/331) to the atomization of Sn. A calculation based on x-order kinetics and the Arrhenius equation was given which leads to a function of absorbance temperature and time and which allows activation energy and order of the atomization pro- cess(es) to be found from the linear plot(s).For both the atomization of In (95/252) and Sn (95/331) the influence of the atomizer surface and a palladium chemical modifier was considered. The atomization mechanism of In seemed to be identical for the pyrolytic graphite coated and uncoated electro- graphite tubes and the rate-limiting step for the atomization changes from 1st-order kinetics at lower temperatures to nearly 3rd-order at higher temperatures. These workers suggested that the In moves from a dispersed state to agglomerates with increasing temperature. However for the zirconium-treated tubes the atomization of In is controlled by a single mechanism with a kinetic order of approximately 2/3 and an activation energy of 186+ 13 kJ mol-l.It was suggested that this is due to relatively weak indium-zirconium interactions and the release of In from the sphere of molten In metal on the zirconium surface. In the presence of a palladium chemical modifier based on the observed 1st-order kinetics and an activation energy of 421 & 27 kJ mol- ' a simple mechanism was proposed in that the In was released from a solid solution of In and palladium on the pyrolytic graphite surface. For the atomization of Sn (95/331) results from a pyrolytic graphite coated electrographite tube gave two linear regions corresponding to kinetic orders and activation energies of 1.10 and 450 kJ mol-' at lower temperatures and 0.47 and 210 kJ mol-' at higher ones respectively. It was proposed that carbon reduction of SnO,(l) to Sn(g) was the rate-determining step at low temperatures.At higher temperatures the rate- determining step was Sn,(g) to Sn(g). Zirconium-coated graph- ite gave a single line corresponding to an order of 0.99 and an E of 429 kJ mo1-'. Similar values to those obtained in the low-temperature region for the pyrolytic graphite coated sur- face but with a lower appearance temperature for the Sn signal indicated a different mechanism. It was proposed that zir- conium effectively prevented the formation of gaseous SnO,. A palladium-coated graphite surface also gave a single line with an order of 1.07 and an E of 838kJ mol-' and an elevated appearance temperature indicating a strong inter- action between the analyte and palladium. It was suggested that palladium promotes the reduction of SnO or SnO to Sn which also forms a solid solution in palladium.From a practical point of view improved sensitivity with zirconium- and palladium-coated graphite tubes was found. Similar results were also obtained for the atomization of In and Pb (94/C3371) and in addition the mode of sample deposition did not influence the atomization mechanism for Pb. With either hydride vapour or aqueous solution methods of sample intro- 212 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10duction the same mechanism in either zirconium- or palladium- coated graphite tubes was found. Chinese workers (94/2407 95/56) have studied the role of the n-component in Zeeman-effect AAS paying particular atten- tion to the interrelation between the n-component and polar- izer in transverse magnetic field modulation Zeeman-effect AAS.The calculated and experimental values for the relative sensitivity coefficient for 32 elements and 34 lines in the absence of a polarizer were also presented. 1.2.4. Interferences A review appeared in Russian (94/2594) containing 217 refs. covering the last five years on the use of chemical modifiers for the determination of trace impurities in complex samples by ETAAS. The role of chemical modifiers in the analytical process as well as the chemical modifier influence on all elements in the sample and the use of different chemical modifiers for analyses were broken down into the following groups of sample types geological medical biological technological ecological and pure materials and chemicals.1.2.4.1. Spectral interferences. The conference reports on the effects of chemical and spectral interferences in the determi- nation of Zn in sea-water and spectral interference on the Pb 283.3 nm line in Zeeman-effect AAS and discussed last year (see J. Anal. At. Spectrom. 1994 9 213R) have now been published (94/2957 and 94/2964 respectively). Aller (94/3288) has examined the roll-over effect with Smith- Hieftje background correction for an Au HCL at 242.8 267.6 and 274.8 nm. Hardly surprisingly this worker comes to the same conclusions as those of de Loos Vollebregt and de Galan in their study of roll-over effects published in Spectrochim. Acta Part B 1986 41 597.The roll-over effect was affected mainly by the relative sensitivity and stray light level. It was found that the stray light produced in the HCL was different for each wavelength range and its level during the low current pulse was modified by the presence of vanadium and copper in the atomizer. Chinese workers (94/3048 95/224) examined the nature and source of the background absorption of samarium (94/3048) and europium (95/224) matrices. For samarium the back- ground absorption can be reduced by using nitrate salts. With a europium matrix there is one peak for EuC1 which arises from the evaporation of EuCl,. Two peaks were observed in the background absorption due to Eu(NO,),. The first peak arose from NO and the second from Eu20,.These workers found that the background interferences could be decreased or eliminated by the choice of an appropriate signal measure- ment time optimum pyrolysis temperature and the use of chemical modifiers though no indication was given as to which were used. 1.2.4.2. Chemical modijiers-general. Workers at Strath- Clyde have continued their investigations into the effectiveness of various chemical modifiers by the use of ion chrornato- graphy. Belazi and Littlejohn (94/C3482) examined the effects of ammonium dihydrogen orthophosphate ammonium nitrate nitric acid and ascorbic acid on the removal of chloride and sulfate from sea-water deposits in a graphite atomizer. Without a chemical modifier sodium chloride was vaporized at a temperature of 800-1000 "C and sulfate was lost at 1000 "C.When equimolar amounts of the chemical modifiers were added to 10 p1 of two-fold diluted sea-water chloride was vaporized at temperatures < 800 "C except with ascorbic acid. Up to 5% m/v ascorbic acid had no effect on the vaporization of chloride. With nitric acid chloride was almost totally removed at a pyrolysis temperature of 200°C. Addition of ammonium nitrate removed some chloride at 200"C but the remainder was not vaporized until 1000 "C. Ammonium dihydrogen orthophosphate allowed almost complete removal of chloride at 500-600 "C. The decomposition of sulfate was not affected significantly by the presence of these modifiers with the exception of ammonium dihydrogen orthophosphate which reduced the vaporization temperature from 1000 to 700°C.These results tended to confirm with direct experimen- tal evidence what others had suggested and it is clear that many of the reactions between interfering matrix components and the chemical modifier take place at lower temperatures than previously thought possible. The role of ascorbic acid is one that many find confusing. Some workers have found the use of ascorbic acid to be of benefit while others have found that it has no beneficial effect whatsoever. Rock (94/C3453) considered the use of hydroxylamine hydrochloride as a reducing agent instead of ascorbic acid. The advantage of using hydroxylamine hydrochloride is that it can be mixed with the palladium solution unlike ascorbic acid which causes precipi- tation of palladium.A more consistent performance with reduced palladium was claimed though during the presentation it became clear that wall atomization and peak absorbance measurements were being used for assessment purposes. Workers from Hitachi (94/3311 94/3334) have continued their studies into the use of alloy phase diagrams in an attempt to elucidate the role ofchemical modijiers and the atomization process. Using the two-line method of establishing the tempera- ture within a graphite tube atomizer these workers (94/3311) investigated the effective vapour temperature for Se in the presence of palladium or rhodium. In the presence of these metals the effective vapour temperature was increased by 400°C and this effect was attributed to the formation of intermetallic compounds with palladium or rhodium resulting in the activity coefficients of Se becoming < 1 thus raising the atomization temperature.The effective vapour temperature of Se atomized from the platform was 200 "C higher than atomiz- ation from the tube wall. A urine matrix was used to investigate excitation interferences and the presence of an oxidizing agent increased the effective atomic vapour temperature of Se to >8OOO"C. It is difficult however to understand how the vapour-phase temperature can be so much higher than the atomizer. This interference could be reduced by increasing the amount of palladium or rhodium or by the addition of a reducing agent. Similarly these workers (94/3334) assessed the role of Ag Au Cd Cu Mg Pd Pt and Sb as chemical modifiers for Pb and Sn.The effective temperature profiles of the analytes were obtained in the presence of various modifiers and the phase diagrams for the alloys formed constructed. When the activity coefficient of the analyte was < 1 intermet- allic compounds were formed and the atomization was shifted to higher temperatures. Atomization was not changed if the chemical modifiers formed alloys with Pb that had a melting- point lower than the pyrolysis temperature and the initial atomization temperature for Pb. For chemical modifier salts such as those containing magnesium which were neither reduced to metal nor formed alloys with the analyte during ashing and atomization the role involved suppression of vaporization of metal halides with higher vapour pressure. 1.2.4.3. Chemical modijiers-palladium.Once again with respect to chemical modijiers palladium is the reagent that has attracted most attention in the period covered by this Update. It seems that various groups are looking in more detail at how palladium functions and also how applicable palladium either alone or in conjunction with other reagents is for stabilizing elements such as As and Se when present in different inorganic and organo-forms. This work has significant relevance to speciation studies. Matsumoto (94/2547) discussed the use of palladium as a chemical modifier for Group 3 and 6 elements in a review containing 42 refs. The use of MS to elucidate the Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 213Rvaporization and atomization processes of As and Se in the presence of palladium was also discussed.The work of Qiao et al. (94/3346) concerning the mechanism of action of palladium in reducing chloride interferences was discussed in detail last year (see J. Anal. At. Spectrom. 1994 9 213R). In contrast to this study and many others over the years which have shown how effective palladium is as a chemical modifier in overcoming chloride interferences Pszonicki and Essed (94/3155,95/216) claimed that palladium is only a suitable chemical modifier in aqueous nitric acid (95/216). They found that the interference effect of chloride on Pb depended upon the properties of the chlorides present and on the solution in which the sample was dissolved. With a large excess of chloride especially in dilute hydrochloric acid the palladium was converted into an unstable chloride which was responsible for some losses of Pb during the pyrolysis step.However in subsequent work the same workers (94/3155) found that the addition of magnesium nitrate eliminated the losses of Pb during the pyrolysis step and overcame the chloride interference problems. Not surprisingly this is the same result as was found by most other workers with this chemical modifier combination and which has been in the literature for the last six years. Liang and Ni (94/3364) considered the release mechanisms of Ag Co Mn and T1 with a palladium chemical modifier. For Co and Mn no change in the activation energies was observed by the presence of pal- ladium. The activation energy was decreased for Ag and increased for T1 when palladium was present.They found that the palladium stabilizing effect was more pronounced for the relatively volatile elements which can be stabilized to a higher tolerable pyrolysis temperature owing to the formation of a relatively strong palladium-analyte interaction. The relatively weak interaction between palladium and Co or Mn accounts for the similar activation energies obtained both in the absence and presence of palladium. Johannessen et al. (94/2186) compared a series of chemical modijiers i.e. nickel nitrate magnesium nitrate copper nitrate copper nitrate mixed with magnesium nitrate palladium nitrate and palladium nitrate mixed with magnesium nitrate for their effectiveness in stabilizing selenite selenate seleno- methionine and trimethylselenonium. None of the examined chemical modifiers stabilized all the different Se species to the same extent.In aqueous solutions addition of 2.7 pg of pal- ladium or 7.5 pg of palladium plus 5 pg of magnesium nitrate stabilized selenite selenate and selenomethionine equally though the signal response for trimethylselenonium was only 55% using palladium and 85% with palladium and magnesium nitrate. Various chemical modifier combinations and mixtures were applied to the determination of Se in serum and urine. The recommended chemical modifier combination was that of 7.5 pg of palladium plus 5 pg of magnesium nitrate which gave results that were in good agreement with the certified values for Se in NIST SRM 2670 Freeze-Dried Urine and a serum RM though these are known to be spiked with selenate.This chemical modifier was considered to be the best of those investigated despite the impaired sensitivity towards trimeth y lselenonium. Sneddon and Farah (95/23) found that a combined chemical modif er of palladium and magnesium nitrates allowed compro- mise pyrolysis temperatures to be used for the simultaneous determination of As Cd Pb and Se. However no details were given of the instrumentation used in this study. For the determination of Co in serum (95/153) palladium nitrate was used as the chemical modifier. Chinese workers (94/1785) found that a combined nickel nitrate and palladium nitrate mixture was the optimum chemical modifier for the determi- nation of Se in drinking water. Zhixia et al. (94/2202) used palladium as a chemical modifier for the determination of Si in low-alloy steels.Sensitivity was improved by the use of palladium. For the determination of Sn in serum (95/33) palladium and ascorbic acid were compared as chemical modifiers. The optimum chemical modifier was palladium and XRD measurements of pyrolysed residues indicated the pres- ence of Pd3Sn2. For the determination of trimethylselenonium in urine samples Tsunoda et al. (95/438) applied a palladium chemical modifier after solvent extraction of the trimethyl- selonium as an ion pair with tetrakis( 4-fluorophenyl) borate. Fenbutatin oxide in fruit (95/456) was determined indirectly by extraction with ethanol and subsequent determination of the Sn with the use of palladium chloride as a chemical modifier.Sachsenberg et al. (94/1611) applied a mixed chemical modifier of ammonium oxalate and tetraamminepalladium(n) chloride to overcome the interferences in the determination of trace elements in sea water. For Mn and Pb this chemical modifier combination allowed direct determinations but for Cd only ammonium oxalate could be used. These workers examined the geometry of the micro-distribution of palladium on the palladium-conditioned graphite platform to investigate the possible stabilizing effects of palladium on the analytes that was observed with the different chemical modifiers. Fractal characteristics of the palladium elemental distributions were ascertained by SEM and energy dispersive X-ray spectrometer image box counting analysis. These investigations indicated differences in the structure of palladium deposits on the platform.It was felt that these variations in the palladium geometry affected the analytes to a certain extent. The increasing importance of determining organotin com- pounds in potable water supplies means that several workers have turned their attention to the optimum chemical modifiers for the determination of Sn in organic extracts. Previous recommendations for this determination relied upon coating of the graphite tube with refractory elements to prevent interaction with Sn even though this is a time-consuming and non-reproducible technique. Li et al. (95/32) considered the effect of oxygen atoms in the solvent and ligand by examining the sensitivity for Sn for tetrabutyltin tributyltin chloride dibutyltin diacetate and dibutyltin dilaurate in the presence of toluene ethyl acetate or tributyl phosphate.As a chemical modifier PdC12(CH3CH)2 was employed. The results showed that the presence of tributyl phosphate and oxygen in the organotin compound enhanced the sensitivity for Sn. Dadfarnia et al. (94/2210) applied a 4-methylpentan-2-one solution of palladium as chemical modifier for the determi- nation of Sn in toluene-extractable organotin compounds from sewage effluents and a complex simulated effluent. 1.2.4.4. Other chemical modifiers. Although palladium with or without another reagent appears to be the chemical modifier of first choice there are situations and elements where pal- ladium is not the optimum choice for a chemical modifier. In these situations a mixed metal chemical modifier could be more appropriate. Dahl et al.(94/2209) investigated the effectiveness of metal chemical modifiers for the determination of Sb in aqueous samples blood and urine. A radiotracer technique was used to investigate the effectiveness of the thermal stabiliz- ation. A purge gas of hydrogen was introduced only during the pyrolysis step. After pyrolysis the activity of lz5Sb was counted and compared with that of control samples which had been allowed to dry in air at room temperature. The best results were obtained with a chemical modifier solution con- taining 0.025% m/v each of Pd Pt Rh and Ru in 1% m/v ascorbic acid. Applying this chemical modifier mixture pyrol- ysis temperatures up to 1200 "C gave quantitative recoveries of Sb with an overall RSD of 3.2% (n=20).Matsusaki et al. (95/210) found that a mixture of aluminium and cobalt nitrates proved useful as a chemical modifier for the determination of Ge. An increase in sensitivity of 40-fold 214R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10over that found in the absence of the mixture of metal nitrates was claimed. For the removal of chloride interferences in the determination of Ge a mixture of ammonium acetate with these metal nitrates was suitable as a chemical modifier because chloride formation of aluminium was masked by acetate and the volatile ammonium chloride formed could be easily removed from the atomizer. The tolerable concentration of co- existing chlorides was approximately ten-fold or more greater than in the absence of ammonium acetate.The sulfate inter- ference could also be removed by the addition of a mixture of ascorbic acid and ammonium EDTA with cobalt and alu- minium nitrates. The tolerable concentration of co-existing sulfates was also 200-fold greater than in the absence of these reagents. Chinese workers (95/83) compared the chemical modification capabilities of nickel and calcium nitrates for the determination of Ge in plasma and urine. Unfortunately it is not clear from the abstract which chemical modifier they found to be the most effective however these workers have developed a method and have finished the determination of Ge in the preclinical animals and are about to start experiments with 132Ge. Several different metals have been examined as chemical modijiersfor Au by Thomaidis et al.(94/C3502). Only Eu Pd and Rh increased the thermal stabilization of Au to 900-1000°C. These workers also examined the stability of Au solutions in the autosampler cups and found that the Au solutions were only stable in the presence of 0.25 g I-' of ammonium thiocyanate or 0.5 g 1-l of ascorbic acid. Biological and geological samples were analysed. Botelho et al. (95/322) compared diferent chemical modijiers atomization surfaces and potential interferences for the determi- nation ofB. Calcium as chloride and nitrate nickel as chloride and nitrate magnesium yttrium and lanthanum all as chlorides were compared. From a consideration of the pyrolysis tempera- ture and sensitivity calcium chloride was considered to be the best.Ammonium hydrogen phosphate and manganese and iron chlorides all showed severe signal depression though sodium and magnesium chlorides had little effect. Severe memory effects were observed which required the measurement of a blank solution after each sample. No advantages were found for the use of alternative atomization surfaces such as tungsten carbide or tantalum foil and atomization from the wall of a pyrolytic graphite coated electrographite tube was preferred. The recommendation of a calcium chemical modifier for B agrees with the results of Wiltshire et al. (95/321) who found a mixed calcium-magnesium chemical modifier to be the best and whose work was discussed earlier (see section 1.2.3). For the determination of Bi in kidney liver brain and bone platinum was employed as the chemical modifier (94/1047).The samples were digested and calibration was established in matrix matched solutions from digested tissues obtained from unex- posed animals. Magnesium nitrate was used as the chemical modifier for the determination of Mo in serum (95/450) and a detection limit of 0.3 pg 1-' was found. Vanadium and vanadium plus molybdenum chemical modijiers were applied by Manzoori and Saleemi (94/2934) in the determination of Cr in serum and lake water samples with high salinity. These workers examined several other chemical modifiers suggested in the literature for Cr but found that ammonium vanadate (20 pg of vanadium) was the most effec- tive for this study with improved recoveries and longer tube lifetimes when the chemical modifier was employed.The detec- tion limit (3s) was found to be 0.2 pg 1-'. However the results were all based on peak absorbance measurements and with wall atomization. Koshino and Narukawa (94/3000) investigated the elimin- ation of the sodium nitrate-borate matrix interference on the determination of Mn in geological samples. Chemical modifiers of magnesium nitrate nickel nitrate and palladium nitrate were examined and for this particular matrix interference (0.45 mol 1-' sodium nitrate and 0.05 mol 1-l boric acid) which produced an 80% reduction in the integrated absorbance signal for Mn. A nickel nitrate chemical modifier was found to give the best sensitivity and smallest background signal. Zu and Li (94/2412 94/2888 95/235) examined the inter- ference eflects of calcium chloride on the determination of Mn.A chemical modifier of nitric acid shifted the Mn signal to a higher temperature increased the sensitivity and improved the signal shape. The interferences by magnesium strontium and barium chlorides were found to be similar to calcium chloride. He (94/3323) applied lanthanum as a chemical modifier to the determination of Sc in titanium and iron ores. Lin et al. (94/2410) determined Sn in blood with potassium nitrate as the chemical modifier. Japanese workers (95/437) used a mixed chemical modifier of nickel phosphoric and ascorbic acids for the determination of Sn in whole blood and found a detection limit of 2.5 pg I-'. Indian workers (94/3018 95/333) investi- gated the chemical modification of Sn with silver gold zirconium molybdenum and tungsten from powder X-ray diffraction (94/3018) and ETAAS measurements (95/333).The carbide-forming chemical modifiers (molybdenum tungsten and zirconium) shifted the Sn signals to lower atomization times. Palladium was found to be the best of the non carbide- forming chemical modifiers (gold palladium and silver) giving increased atomization times the best sensitivity and to be the most efficient in preventing losses of Sn. This was attributed to the formation of SnPd as an intermediate. Chinese workers recommended ascorbic acid as a chemical modifier for the determination of Ru (94/2889) in water. A detection limit of 0.27 pg 1-' was found. Yet another group of workers (94/1667) have decided to investigate the role of the chemical rnodiJier for the determination of Pb in whole blood.Not surprisingly these workers found exactly the same results as everybody else and recommended diammonium hydrogen phosphate. They also compared the use of this reagent in conjunction with palladium chloride and found worse precisions with this combination of 3.1-9.1 YO in the concentration range 31-624 mg 1-' compared with 2.2-6.3% with diammonium hydrogen phosphate. Indian workers (95/43) suggested the use of bismuth nitrate as a chemical modifier for the determination of Pb in fish tissue. These workers claimed that the detection limit of 0.9 pg 1-l obtained with bismuth nitrate was better than that found when using a palladium nitrate chemical modifier. However no further details were available to allow further assessment of this work.Russian workers (95/163) proposed a new class of chemical modifiers aminopolyphosphonic acids for the deter- mination of Pb in copper chloride copper-based alloys fresh water sediments and blood plasma. These chemical modifiers were claimed to allow a 10- to 100-fold improvement in the detection limit though quite how this was achieved is not at all clear from the abstract. Huang (94/2211) examined a variety of chemical modijiers for the determination of Si in bone and other tissues. A mixed chemical modifier of lanthanum nitrate and calcium chloride was used. Ammonium dihydrogen phosphate was added to sample digests to eliminate the interferences arising from the soft tissue samples (brain kidney liver spleen and heart).This mixture was not able to overcome the interferences arising from the bone digests and for these samples the mixed lantha- num and calcium chemical modifier plus the addition of disodium hydrogen tartrate was successfully applied although wall atomization was used. Concentrations of Si in the sample digests were determined against a calibration curve established with aqueous Si solutions diluted with the same chemical modifier mixture and integrated absorbance measurements. A characteristic mass of 37 pg and detection limits (3s n = 10) of Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 215R0.9 and 0.14 pg g-' wet mass for bone and soft tissue respectively were found with recoveries of the order of 100%. Volynsky et al.(95/190) examined the use of organic chemical modijers such as ascorbic acid and glucose under STPF conditions with thermal and elemental techniques. Ascorbic acid did not affect the integrated absorbance values for Pb and Sn but increased that for Ga by 1.37-fold. The appearance times for all three elements increased in the presence of ascorbic acid. It was found that the ascorbic acid melt wets Ga and Pb oxides better than the glucose melt. Electron microscope studies showed that after drying and pyrolysis at 500°C of a solution containing ascorbic acid Ga and Pb only 14 and 7% of the corresponding metal was retained on the surface of the carbon residue. For glucose the values were 30 and 25% respectively. These workers proposed that the increase in appearance time in the presence of ascorbic acid was a result of diffusion from the carbon residue at the atomization stage.Indian workers (95/327) employed ascorbic acid as the chemi- cal modifier for the determination of T1 in nickel-based alloys after a microwave digestion procedure with sulfuric nitric and hydrofluoric acids with a continuum source background cor- rected ETAAS system. They found that the use of STPF conditions improved the absorbance signal and the precision of the measurements (2-10% without a platform and 0.2-3% with a platform) and that the sulfuric and ascorbic acids overcame matrix interferences. The detection limit (3s) was 1.0 pg 1-' and good agreement with certified values was obtained for a range of nickel-based RMs. Pergantis et al. (95/345) applied simplex optimization to establish the optimum experimental conditions for the determi- nation of As in a marine RM.Four experimental variables were considered pyrolysis temperature; atomization tempera- ture; chemical modifier concentration; and atomization ramp times. These workers found that this approach provided a pow- erful means of rapidly improving the experimental conditions used. Excellent recoveries of As were obtained when the optimum conditions established by the simplex process were used to determine As in standard solutions of arsenobetaine arsenocholine and tetramethylarsonium iodide. 1.2.5. Developments in technique Material presented in a thought provoking lecture at the XXVIII CSI Post-Symposium on Graphite Atomizer Techniques in Analytical Spectroscopy in 1993 and discussed last year (see J.Anal. At. Spectrom. 1994 9 213R) has now been published by Gilmutdinov et al. (94/2979) in the form of a full paper. The work discussed the signal obtainedfrom ETA systems in terms of the number of absorbing atoms as well as their spatial distribution in the atomizer volume. The results obtained showed that cross-sectional distribution of both radiant intensity and the analyte can be highly non-uniform within the atomizer. This results in the fact that the absorbance measured by a PMT-based detection system is dependent not only on the number of free atoms but also on their gradients and the gradient of the radiation beam. To obtain an analytical signal that would be independent of these non-uniformities spatially resolved detection is necessary.To achieve this a solid-state detector should be used. The absorbance recorded by such a system depends only on the number of absorbing atoms. Such a system would have the advantage of both spatially resolved detection and the fact that these spatially resolved absorbances could then be integrated. In principle the absorbance should be integrated not only over time but also with respect to the monochromator slit and this should be used as a measure of analyte concentration in the sample. This would provide more analytical information and improved linearity for AA measurements. In the previous Update the publication of this work was awaited with interest and the full paper lives up to the expectations of the conference report.Harnly (94/C3468) has continued the work on simultaneous multi-element E TAAS with an investigation into the well-known problem of atomizing different elements under identical conditions. The effect of furnace parameters on simultaneous multi-element measurements was examined in a commercially available transverse heated graphite atomizer (THGA). The sensitivities and S/N ratios for Cd Cu Cr Pb and V selected to provide a representative range of atomization temperatures were characterized as a function of atomization temperature with the use of a mixed palladium and magnesium nitrates chemical modifier and with normal or end-capped THGA tubes to restrict analyte loss. Using a normal open tube without chemical modifier and an atomization temperature of 2500"C the minimum for an acceptable V signal produced sensitivity losses ranging from 9 to 28% for the other four elements.The loss of Cd Cu and Pb was caused by a strong convection component though with end-capped tubes losses without a chemical modifier were less strongly influenced by convection. With a chemical modifier losses from end-capped tubes were controlled mainly by diffusion. Simultaneous multi-element detection has again been receiving attention particularly with the release of a new commercial simultaneous multi-element ETAAS system from Perkin- Elmer. The search for such a technique was compared with the 'search for the Holy Grail' by Shuttler et al. (94/C3430). The system uses multiple lamps as line sources an Cchelle polychromator with a solid-state detector and a THGA with longitudinal Zeeman-effect background correction.Similar detection limits were obtained with the instrument running in either single- or multi-element mode with up to six elements being determined simultaneously. Smith and Harnly (94/C3467) examined the use of a double atomizer for ETAAS. The double atomizer consisted of an integrated contact furnace (ICF) located directly above a graphite cup. The cup was placed 3 mm below the ICF and hence was not in contact and the ICF had a hole drilled in the bottom to admit the gases from the cup. Both the cup and ICF had separate power supplies and were operated indepen- dently and mounted in a modified vacuum cross that permitted operation at low 0.1333 Pa and high pressures 10.133 x lo5 Pa. It was found that when the ICF was at a constant temperature the vapour evolved from the cup was drawn into the inlet hole of the ICF.The sensitivity for Cd was found to be greater than that for an HGA-500 equipped with a platform when using a cup and ICF temperatures of 200 and 1000"C respectively. Parameters such as inlet hole size spacing between the cup and the ICF and the respective temperatures were examined. Further work on furnace atomization plasma excitation spec- trometry (FAPES) has been reported by Hettipathirana and Blades (94/2178). The interference effects of sodium chloride and sodium nitrate were discussed and further details are given in the Atomic Emission Update. The emission intensity in the rf plasma was decreased for both Ag and Pb signals in the presence of both salts.These workers also suggested that both salts acted as carriers resulting in early atomization of both Ag and Pb. In an attempt to produce multiple line sources for ETAAS Wichems et al. (94/C2020) suggested the use of an ICP to replace the HCLs. Solutions of the elements to be determined were aspirated into the ICP and the resulting emission focused through a graphite atomizer (or flame) followed by a mono- chromator and detected with a linear photodiode array. While this could overcome the problems associated with using a continuum source it does seem a rather elaborate way of producing a multiple line source. A few reports appear every year on the use of an electrother- 21 6 R Journal of Analytical Atomic Spectrometry August 199.5 Vol.10ma1 atomizer for molecular absorption measurements. Chinese workers (95/80) determined S by volatilization as Ins in a pyrolytic graphite tube. A Be HCL was used to measure the Ins absorption band at 234.5 nm and this method improved the S/N ratio compared with the use of a continuum source. Satisfactory results were claimed for the determination of S however more details were not available. With respect to absolute analysis Chinese workers are the most active. The current trend appears to be one of establishing both the stability of the atomization efficiency with respect to temperature and the stability of the characteristic mass over time. Ensuring that these are stable both in different sample types and over time are important issues for the ability to achieve absolute analysis.Zheng et al. (94/1272 94/3049) considered the factors that influenced the characteristic masses (mo) for Ag Cd Cry Gay Ge and In over a temperature range of 1800-2600 K. The experimental results showed that the mo values appeared to be stable to better than 10-15%. The influences of atomization temperature on the atomization efficiency [defined as ratio of mo(calc)/m,(exp)] were studied using wall platform and V-shaped boat atomization. For Ag and Cd the atomization efficiency did not change significantly when either platform or V-shaped boat atomization was used. However for Cr Gay Ge and In the atomization efficiency was found to increase with the increase in atomization temperature although values of 20-50% were observed. The use of a chemical modifier such as palladium or nickel increased the efficiency values.Further work from the same research group (94/2892) investigated the day-to-day stability of mo obtained from one instrument. For the determination of As Cd Co Cry Cu Mn Ni and Pb in sea-water and As in toys the results showed that the characteristic mass values obtained by different workers from different samples and on different days were generally stable. Ma et al. (94/1625 95/82) discussed the determination of Cr (94/1625) and Cd (95/82) in environmental samples by absolute analysis. In both instances the use of a chemical modifier dilute ammonia solution for Cr and palla- dium and ascorbic acid for Cd were necessary to overcome interferences. Subject matter previously discussed under this category in previous Updates such as linearization are now found under section 1.5.The desire to increase the sample throughput of ETAAS systems is an issue that concerns many. Halls (95/307) has been one of the more active workers in this area and has developed an interface device that enables an older Perkin- Elmer AS1 autosampler to be started before the HGA-400 furnace programme has ended. This allowed a reduction in the total cycle time of 10-15 s without any degradation in analytical perfomance. Shrader et al. (94/C1946) discussed the use of new hardware and software which allows the use of fast furnace time-temperature program. Minimum program times and hot injection were employed to produce a two-fold improvement in productivity. 1.3. Chemical Vapour Generation Developments in chemical vapour generation have once again been directed at improving analytical sensitivity and accuracy and to give additional information notably speciation.Im- provements in vapour generation are not only of benefit in AAS but also in AES AFS and MS therefore where appro- priate experiences in vapour generation in the range of spectro- scopies will be recorded in this section of the ‘Updates’. No single outstanding development or strong general trend has been identified since the last ASU review (J. Anal. At. Spectrom. 1994 9 213R) and publications once again reflect repetition consolidation and modest developments in technique and understanding. Most relate to specific applications rather than to general methodology. 1.3.1.Hydride generation Though a significant number of workers continue to discover the benefits of FI-HG the technique has in fact become firmly established as regular practice in many laboratories. Overcoming interferences in HG continues to exercise many workers. It has been argued (Stockwell P. Analysis Europa 1994 Dec. 41) that the simplest way of overcoming inter- ferences is to dilute the sample and that AFS provides the greater sensitivity required to compensate for increased dilution. This view has some support in the fact that there has been a modest increase in the number of reports on the determination of As Sb and Se by HG-AFS. 1.3.1.1. General studies of fundamentals techniques and instrumentation. Interferences are an ever present potential problem in hydride generation methods of analysis and much effort continues to be spent on their identification and elimin- ation.An investigation of the interfering eflects of cadmium and zinc on the determination of As Bi Hg Sb Se Sn and Te found that the effect of cadmium was greater than that of zinc (94/2587). A procedure was developed that overcame these interferences except that Te could not be determined when cadmium was present. The mutual interferences of As Sb and Se along with the effect of bismuth tellurium and tin on the determination of the these elements have been studied by means of a twin channel HG flow system (94/1639). It was found that the interactions of As Sb Se and Sn on each other were similar and occurred in the gas phase. Bismuth and tellurium also interfered in the liquid phase.Antimony and As could also interfere spectrocopically in the wavelength range 190-235 nm owing to absorption by their molecular bands. Alkaline mode’ operation has been claimed to reduce inter- ferences by Group 10 and 1 1 elements and to have the potential for speciation analysis of hydride forming elements deriving from differences in the stability of species in different pH media (94/C1913). In this mode of operation acid is mixed with an alkaline solution of the sample containing NaBH to generate the hydride. The technique was evaluated using FI-HG-ICP and gave sensitivities for As Bi Ge Pb Sb Se Sn and Te comparable with those of the traditional method. Vapour generation of a oolatile species of Cd by reacting an aqueous solution of the buffered sample with NaBEt is a very sensitive technique when used with AFS detection. This tech- nique is also applicable to Pb.Thompson (94/C3432) has reported detection limits of 5 ng 1-1 Cd and 150ng 1-1 Pb. Generation of volatile species of Cd and Zn using NaBH in an FI system has also been reported (94/C3384). The addition of an organic reagent greatly enhanced sensitivity and with AFS detection achieved detection limits of 8 ng I-’ Cd and 8 pg 1-1 Zn. Surfactant-based ordered media are of increasing interest in analytical atomic spectrometry. A volatile Cd species has been readily formed in cationic vesicles by reaction with with NaBH (94/3036). This Cd species increased the detect- ability of Cd by ICP-AES by a factor of 5. A 2-fold improve- ment in the ICP-AES sensitivity of As and Pb was also noted.The publication also reviewed the general applications and benefits of surfactant-based ordered media in analytical atomic spectrometry. In HG or CV techniques loss ofsensitivity and blockage of transfer lines due to excessive moisture carried to the atom cell or lodged in the lines is not uncommon. Sundin and Tyson (94/C1939) have described a system whereby water was removed by passing a dry sheath gas around the outside of a hygroscopic Nafion membrane transfer line. The Nafion dryer removed water at the rate of 1.7 to 4.9 mg min-’ depending upon operating conditions. There was a slight loss in sensitivity Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 21 7 Rin the determination of As and Hg due to the larger internal volume of the drier.Two types of gas-liquid separators have been examined with the aid of radiotracers (95/112). The techniques studied were the 'classical' separation by gravity and that based on diffusion through a permeable tube. The As species studied were As"' AsV' monomethylarsenic acid and dimethylarsenic acid. Yield and response were investigated as a function of experimental variables. It was concluded that only the classical method with a cold trap was satisfactory. The latter approach was the basis of an automated procedure where electromagnetic relays and timers were used to control the hydride feed to an electrically heated quartz tube atomizer The construction and application of a laboratory-made double input hydride generator has been reported (94/3100). Recoveries of 98.4-103.0% for As and 97.2-108.0% for Sn in steel were achieved. A review of the development state-of-the- art and future trends in FI-HG-AAS from the point of view of automation has been published by Tao and Fang (94/2066).( 94/c 3 3 7 5 ) . 1.3.1.2. Determination of individual elements. In this section of the 'Update' some references will be made to papers where several elements have been studied. In such cases the reference will be presented once only in the paragraph relating to the element that is first alphabetically. Antimony and As are frequently determined in the same matrix. L-Cysteine first introduced by Brindle (Anal. Chem. 1992 64 667) has been comprehensively studied as a reducing and releasing agent for Sb and As by Welz and Sucmanova using FI-HG-AAS (94/3002 94/3003).Under optimized conditions the detection limits were 0.05 pg 1-' Sb and 0.01 pg 1-' As with linear calibration graphs up to 10 pg 1-' Sb and 5 pg 1-' As. The method was developed for the determination of Sb and As in copper and steel. The tolerance limits (<lo% interference) in the determination of Sb were 250 mg 1-' nickel and 500 mg 1-' copper in the determination of As the limits were 200mg 1-' nickel and >lOOOmg I-' copper. In addition to As and Sb Jiao and Lin (94/2710) have determined Bi in geological samples. Using a dual channel instrument with AFS detection As and Sb were determined simultaneously. Bismuth was determined separately but by the same procedure.Detection limits were As 0.79 pg 1-'; Bi 0.46 pg 1-l and Sb 0.29 pg 1-'. Selenium was another element determined in combination with Sb (95/199). In this work tetrahydroborate ( H I ) was bound to an anion-exchange resin. Antimony was reduced to Sb"' with 0.1 mol I-' KI and Se to Se" with 6 moll-' HC1 and heating. Transition elements were not separated from the sample. In the analysis of SRMs results were within certified values. A significant step in the determination of As in workplace air based on HG-AAS has been the validation of a proposed international standard method (94/2923). Particulate As com- pounds were collected on a filter followed by acid digestion. Analysis was by both continuous flow and flow injection HG. For the determination of As in orange juice (94/3170) and in milk (95/419) Cervera and co-workers used ashing aids in a carefully controlled dry ashing procedure.The detection limit of the method was 0.1 ng g-' As in the beverage. The accuracy of the method was checked using tomato leaf and powdered milk standards and found to be within 5% of the certified values. Arsenic was determined in landJill waste waters con- taining high levels of copper (10 g 1-') iron (0.2 g 1-') lead (0.2 g 1-') and nickel (0.2 g 1-') by means of pre-reduction of Cu" to Cu' with hydroxylammonium chloride and a KI-ascorbic acid reagent to reduce AsV to As"' and to precipi- tate CuI and PbI (94/1642). A detection limit of 1 pg 1-' As was achieved. An FI stop-flow-HG technique was used to determine As in tap water and soil extracts (94/2891).The sample solution in 4mol 1-' HCl was merged in a knotted reactor and stored in a sampling loop for 40 s to complete reduction to AsV prior to injection. The detection limit was 0.1 pg 1-' As. Cysteine added to urine has been reported to overcome the problem of the pH dependence of the HG sensitivities of As species (95/191). In the presence of cysteine the optimum condition for the determination of all the As species was in the same pH range. A single As species could be used for calibration and for the determination of total As. Increasingly interest is being directed at the species themselves as well as total As. Such information may be obtained either by selective chemical pre-treatment or by chromatography. A comprehensive chemical pre-treatment procedure for the deter- mination of As"' AsV monomethylarsenic and dimethylarsenic in urine has been described by Hanna et al.(94/1729). Recoveries of added As compounds ranged from 95-112% and detection limits were between 0.1 and 0.2 pg 1-' As in the solution injected into the FI system. Ion exchange chromatogra- phy was used to separate As species in urine mineralized with HN03-H2S04-H202 prior to determination by FI-HG-AAS (95/414). Recoveries of added As species were in the range 8543%. The method could be applied to urine samples relating to arsenic exposure. Arsenic species in lake and river waters have been separated by ion chromatography without pre-treatment and in one instance (94/1626) the column output was coupled directly to an HG-AAS system to give detection limits of 0.2-0.8 pg I-' As.In another report fractions were collected and a thermal decomposition procedure prior to NaBH reduction (94/2198) was used; the hydrides were then trapped on a palladium-coated graphite tube prior to ETAAS determination. Detection limits were of the order of 2 pg 1-' As in the injected sample. Two directly coupled LC-HG systems have been described which incorporate on-line oxidation. Photo-oxidation by low power UV irradiation in conjunction with persulfate has been shown to be effective for a wide range of arsenic species (94/1609). Detection limits were typically 50 pg As corresponding to 0.3 pg 1-' As. Anion-exchange HPLC was coupled via on-line thermo-oxidation to an HG-AA spectrometer for the determination of As species in environ- mental samples (94/1640).The thermo-reactor consisted of a loop of PTFE tubing dipped in a powdered graphite oven heated to 140°C. Samples and persulfate were run together into the reactor. Recoveries were ~ 1 0 0 % and the detection limit was < 1 ng As. An automated FI system for the interference free determination of As and Se in serum and urine has been described (94/3167). The sample with digestion reagent was passed through a coil in a microwave apparatus prior to injection into the HCl carrier stream for reaction with NaBH and subsequent detection by AAS. A continuous frow HG system has been applied to the determination of As and Se in highly mineralized water (94/2925). Atomization was in either a heated silica tube or graphite furnace.Significant matrix effects were found only with high concentrations of magnesium sodium and sulfate. The lowest detection limits (0.02 pg 1-l As) were obtained with in-atomizer preconcentration in the graphite furnace. Methods for the determination of Bi Ge In and Pb have been studied by several groups of workers. A complex sample treatment procedure was used for the determination of Bi in geochemical samples (94/3319). The hydride was generated and trapped in an 12-KI solution prior to reaction with Rhodamine B and spectrophotometric measurement. The influence of O2 and H2 in the electrically heated quartz tube on the absorption signal of Ge has been studied (95/165). The atomization of GeH was attributed to collision with hydrogen free radicals while a reduction in signal resulted from the formation of GeO.The mechanisms of hydride generation and atomization of In in the quartz tube have been studied by Liao and Li (94/3320). Under optimized conditions a peak height sensitivity of 0.007 pg was obtained. For the determination of 21 8 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10Pb by HG a series of 22 chelating agents were tested for the generation of plumbane (94/3030). The preferred reagent was 1-( 2-pyridylazo)-2-napthol-6-sulfonic acid (PAN-S) which gave injection of a 3% solution of NaBH in DMF. The detection limit was 8.1 pg 1-' Sn. a sensitivity of 1.3 pg 1-' using a 5 ml sample. Lead and Sn in food have been determined by dry ashing the sample followed by dissolution of the ash and adsorption of the analyte elements onto sulfhydryl cotton from which they were desorbed for hydride generation with KBH and atomization in an air-C2H2 flame (94/C3387).Detection limits were 48 pg 1-l Pb and 50 pg 1-' Sn. Methods including HG for the determination of Se have been the subject of a review in Chinese (95/12). A method using FI-HG-AAS for the determination of Se in blood had a throughput of 120 samples h-' and an LOD of 0.06 pg I-' (95/396). Several reports have been devoted to sample prep- aration prior to HG. Four microwave methods for the digestion of fish tissue have been compared (95/344). The preferred method employed HN03-H2S0,-H,02 digestion with potass- ium hexacyanoferrate(II1) as a masking agent to eliminate interferences. The detection limit was 0.03 pg g-' Se dry mass using a 100mg sample; there was good agreement (within 3.5%) with a mussel tissue reference material.For the determi- nation of Se in pure copper following dissolution of the sample the copper was removed by precipitation the hydride generated with NaBH from the filtrate and the Se determined by AFS to give a detection limit of 0.04 pg 1-' Se (94/2712). Inorganic Se (Se" and total Se) in drinking water has been determined by preconcentration and separation on Dowex 1x8 prior to HG-AAS (95/253). Total Se was determined using permanga- nate digestion and anion-exchange preconcentration. The efect of matrices reducing conditions and interferences on the measurement of total Se and SeIV in environmental materials has been investigated by Blackwell et al.(94/C3462). Conditions affecting the reduction of Sew to Se" the effective- ness of the partial digestion of soils sediments and plant materials with Mg( N03)2 + HN03 and of the total digestion using HF + HNO + HClO were also examined. In-situ concen- tration of Se and Te by trapping the hydrides in a graphite atomizer coated with silver has been examined (94/2185). The trapping temperatures were 200-400 "C for Se and 200-800 "C for Te. The atomization of the Se and Te trapped on the silver surface occurred at 1800°C compared with >2000°C from palladium. Interferences in the speciation of organotin have been studied extensively by Martin and co-workers (94/3292 95/302). The method employed HG cryogenic trapping selective volatiliz- ation followed by quartz furnace AAS.A harbour sediment was characterized in order to identify the agents that could interfere in the speciation. Organic pollutants did not interfere; inorganic elements produced severe problems. A masking agent (L- cysteine) overcame most problems. Several sample pre- treatment procedures have been compared for the determination of butyltin compounds in shellfish (95/338). Digestion with 0.083 mol 1-' HC1 in 16.7% methanol with sonication for 1 h was preferred. The method used HG cryogenic trapping selective volatilization and quartz furnace AAS The detection limit was 2-3 ng g-' Sn wet tissue. For the ultra-trace determi- nation of Sn (94/C3377) the element was first extracted from a 2 moll-' HCl solution onto a strongly basic anion exchanger D-201 following elution of Sn with 0.05mol I-' HNO the hydride was generated and trapped in a palladium-coated graphite tube preheated to 300°C then atomized at 2300°C.A throughput of 25 samples h-' with an LOD of 0.05 pg 1-' Sn was achieved. The determination of Sn in rigid PVC necessitated the generation of the hydride from a sample dissolved in an organic solvent (hot N,N'-dimethylformamide DMF) (94/2249). The sample solution was mixed with H2S04 in DMF and formamide in the hydride generator prior to the 1.3.2. Mercury by cold uapour generation The determination of mercury continues to be the most fre- quently reported analysis by vapour generation techniques. In this section of the 'Update' (1.3) there are as many reports of Hg determination as there are of all other elements combined.In some 15% of the Hg determinations AFS was used as the measurement technique. Most of the papers reviewed here relate to development of techniques for specific analytical applications. These papers have been selected to be representa- tive of techniques available and to encourage their wider use. Full accounts of the determination of Hg in particular sample types will be found in other 'Updates'. A review of Hg determination in China has been prepared by Li and Chen (95/23 1). Refinements of instrumentation and techniques continue to be made. Two on-line digestion CVAFS systems which achieve the sensitivity of a laboratory unit with minimum servicing and reagent consumption have been described (94/C2033 94/C3469). The interference of iodides when tin@) chloride is used as the reducing agent in the CV generation of Hg can be eliminated by the addition of chromium(11).It has now been reported that the addition of an excess of iodide to such a system improves reproducibility and detection limit by stabiliz- ing the Hg (94/3041)! An intermittent second peak observed by Scott (94/1806) in the CVAAS determination of Hg was attributed to HC1 gas. This effect was overcome by adsorption of the HCl gas onto glass wool. Interferences in the efficiency of trapping of CV-generated Hg on an iridium-coated graphite surface were avoided by an additional heating step to clean the furnace following each Hg determination (95/250). Workers in the University of Oviedo (94/2200) investigating the potential of organized assemblies (micelles and vesicles) have recommended on-line drying of the Hg vapour.When the cationic surfactant didodecyldimethylammonium bromide (DDAB) and a membrane drier tube were used detection limits were improved 3-fold over the conventional aqueous technique. The effect of surfactant media on Hg CV generation in both FI and continuousJEow modes has been investigated by Gutierrez and Camara (94/3027). Different mechanisms appeared to be involved in the two flow modes. The best results were obtained in the continuous mode with sodium dioctylsulfosuccinate (SDSS) which gave a 50% increase in sensitivity over a conventional aqueous system with reduced noise level and improved signal stability. The same group of workers have also reported that the micellar media tetradecyl- trimethylammonium bromide (TTAB) and SDSS also reduces inter$erences by arsenic (III and v) cadmium copper lead nickel and selenium on the continuous flow CV determination of Hg (94/3360).Speciation of inorganic Hg" and methylmer- cury has been facilitated by the use of vesicle mediated HPLC coupled to CVAAS (95/325). The vesicular mobile phase was DDAB in acetate buffer containing 5% v/v of modifier methyl cyanide (acetonitrile) and 0.005% v/v 2-mercaptoethanol. The stationary phase was a C18 bonded silica column. The system has been applied to spiked sea-water and urine. Recoveries were 91-103% with detection limits of 0.1-0.2 pg 1-' Hg after off-line preconcentration of aqueous samples. Aqueous-phase ethylation of Hg species with NaBEt has proved to be advantageous in the speciation of Hg in environ- mental samples.In one application the Hg compounds were extracted from sediments by distillation followed by ethylation precollection on a Carbotrap isothermal GC and detection by AFS (94/1615). The distillation approach avoided the matrix effects in the ethylation stage which can arise from alkali digestion. Recoveries were 95 4% and the LOD was Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 219R0.001 ng 1-1 MeHg as Hg. Other workers (95/369) who digested biological materials in methanolic KOH solution prior to ethyl- ation with NaBEt trapping and GC separation do not appear to have noticed any interference and achieved an LOD of 0.3 ng g-' MeHg. Refinement of the GC operating conditions in a Hg speciation system using the ethylation step eliminated the need for a liquid nitrogen cooled trap and avoided some of the thermal decomposition that had occurred during desorp- tion (95/254).The LOD for MeHg was 0.6 pg; up to 80 samples could be analysed in 8 h. High pressure liquid chroma- tography has been used to separate organomercury compounds (94/1689). The separated compounds were converted to Hg(0) in a continuous-flow system by an oxidizing solution (peroxo- disulfate and Cu" in dilute H2S04) followed by a reducing solution (alkaline SnC1,) both of optimized composition. The elemental Hg generated was swept into an AF spectrometer with argon. The determination of total Hg in whole blood by FI-CVAAS has been reported by Guo and Baasner (94/3142).Two oxi- dation stages were employed firstly a KBr-KBrO solution in a microwave heated knotted digestion coil was used followed when cool by a solution of KMn0 and finally Hg" was reduced to Hg(0) with NaBH in NaOH solution. Recovery of Hg was 96-100% and the LOD was 1 pg 1-l Hg in whole blood. The same workers developed a method for the determi- nation of Hg in urine (94/1610). The procedure was similar to that used for whole blood but was operated at room tempera- ture throughout without microwave heating. The LOD was 0.1 pg 1-' Hg. Other workers (94/1767) determining Hg in urine noted that SnC1 reduction leads to greater sensitivity than NaBH but careful sample decomposition was necessary if organomercury was to be measured. Tahan et al.(94/2187) used Purr digestion bombs heated either by convection or microwaves for acid decomposition of whole blood urine and tissue. There was no significant difference in the results from the two heating methods. Convection was slow (12 h) but could handle large numbers of samples microwave digestion required only 70 s per sample. The LOD was 6.6ng g-' Hg in the solid sample. The accuracy of the method was verified with NIST SRMs. Four methods of acid digestion of tissue prior to CVAAS determination of Hg viz ( i ) HN03 ( i i ) HN03-H2S04 ( i i i ) HN03-HC104 and (iu) HN03-H202 have been compared by Adeloju et al. (94/3130). Recovery of added Hg was nearly quantitative in all instances but that of MeHg was best with method ( i i ) . For the determination of total Hg in scalp hair dissolution of the sample with HN03 under pressure prior to CV generation of Hg has been used (94/2965). The Hg vapour was collected on a Au-Pt grid and de-amalgamated at 700°C into the AA spectrometer.The LOD was 0.13 ng Hg. An accuracy of 2.5% in the analysis of several biological and environmental CRMs and SRMs was achieved. Speciation of Hg in human hair has been effected by means of the selective leaching of MeHg with HCl (94/2928). The results agreed with those obtained by solvent extraction methods. Continuous flow and FI techniques achieve typical LODs for Hg of 10-50ng 1-' in aqueous samples (94/C2035 94/C2036). However levels of Hg in natural waters may be as low as 0.2 ng 1-' (94/C3458) hence means of improving sensi- tivity have been developed.A sorption method using the chelat- ing ion exchanger Spheron Thiol (ST) has been used for the preconcentration of Hg (95/306). Both organic and inorganic Hg were adsorbed directly from aqueous samples (1 1) onto the ion exchanger (0.1 g). The ST was separated by filtration and placed in a sample boat. The Hg was released thermally followed by trapping in an amalgamator prior to final thermal release into the absorption cell. These preconcentration pro- cedures gave an effective lo4 increase in sensitivity with an LOD of 0.2ng 1-' Hg in the original sample. Though the procedure just described does not use CV generation of Hg it has been presented here to draw attention to the possibility of high sensitivity Hg determination by alternative methods.Several reports describe methods using amalgamation to improve the sensitivity of CV Hg analysis with detection by AAS or AFS (94/C2032 94/C2035 94/C2036). Fully auto- mated CV-amalgamation/atomization systems have been developed which have both reduced blank values and lowered detection limits to 0.07 ng 1-' Hg (94/3285 94/C3458). The exploitation of such low detection limits is critically dependent upon the elimination of contamination and reagent blanks. 1.3.3. Volatile organo-metallic compound generation and metal vapour separation Traces of Co Fe and Ni in pure water have been determined by conversion to their carbonyls followed by atomization in a microwave-induced plasma and detection by AFS (94/3134). The sample was mixed with thiourea and tris( hydroxymethy1)amin- omethane in a carbonylator at 50°C and NaBH in NaOH solution added.Pure CO was passed through the carbonylator and the generated carbonyl swept through drying tubes into a cold trap (- 60 "C). After 20 min collection the trap was heated at 15 "C min- up to 50 "C. The released carbonyls were passed through the microwave plasma atomizer of an AF spec- trometer. Detection limits were 20 5 and 3 pg for Co Fe and Ni respectively. Metal vapour elution analysis has been applied to the separa- tion of Ag Cu Fe Mn and Nu prior to detection of the atomic vapours by AAS (94/2258). The sample was injected into a molybdenum tube (25 cm long 1.12 mm id) 7 cm of which was packed with tungsten powder. Following drying and pyrolysis of the sample the tube was heated to 1820°C and a gas flow of Ar-H initiated.Silver Mn and Na were successfully detected with retention times of 7.7 2.1 and 12.6 s and LODs of l.Opg 34pg and 25 pg respectively. The metal vapour elution technique was applied by Ohta et al. (94/3128) to the determination of Zn in aluminium metal. The Zn vapour was separated from Al Cu Fe Mg Si and Ti at a column temperature of 1650 K. The LOD was 12pg and the results were in agreement with those obtained by a spectrometric method and certified values. 1.4. Spectrometers A little bit of the early history of atomic absorption spec- trometry has been filled out by Willis (94/2245) who was working close to Walsh in the early 1950s. Apparently Walsh with a background of spectrochemical emission and IR absorp- tion began to wonder in 1952 why atomic spectra were always measured in emission while molecular spectra were studied in absorption.So promising were the experiments which he then initiated that the following year CSIRO filed a patent appli- cation for an AA spectrometer and in March 1954 the technique was demonstrated at an exhibition in Melbourne Australia. Walsh's classic paper (Spectrochim. Acta. 1955 7 108) soon appeared. This led several 'alert minds' to try the method for some trace elements and Mg in plant materials. This was the so-called 'do-it-yourself' period. It was only after Willis had demonstrated that calcium could advantageously be measured in blood serum ('one of the most difficult projects I could have undertaken') that a major manufacturer was interested in taking out a licence to manufacture.In the forty years to the present day the lowering ofdetection limits in A A and in AE has been a challenge to workers in many fields from environmental and clinical chemists to instru- ment designers and academics. Two papers from Winefordner's group on theoretical and practical limits in atomic methods (Spectrochim. Acta Part B 1993 48 757 94/2899 given also as a plenary lecture at the York CSI July 1993) showed how 220 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10limits of detection depended not only upon spectral selectivity and background noise but also on other analytical figures of merit such as efficiency of detection and efficiency of measure- ment. These relationships were discussed in detail as well as their significance to single atom detection.Advice on lowering detection limits in AAS was also offered by Gadsby (94/1849) although the methods recommended use of EDLs rather than HCLs where these are applicable; elimin- ating background; and selection of appropriate matrix modi- fiers must all be well known to alert minds of the present time. A new type of Doppler-free spectroscopy was heralded in a paper from Japan (95/111). Optical heterodyne detection was applied to the Doppler-shifted backward light scattering caused by the inhomogeneity of Rb atoms velocity-selected by a single-mode diode laser. It would seem however that consider- able development will be required before this principle can be used to reduce line-broadening in AA sources.1.4.1. Light sources Hollow cathode lamps boosted glow discharges electrode-free HF discharges and diode lasers have all been the subject of reports this year. Characteristics of HCLs in the pulsed current mode at low and high powers have been examined by Prudnikov and Shapkina (95/182). It appears that higher frequency pulsing at low power improves accuracy and sensitivity in FAAS particu- larly for Cu determinations in rock. The selection of power supply conditions for HCLs for use with Smith-Hieftje back- ground correction was investigated by Chinese workers (95/66) and recommendations for some 24 elements were tabulated. In a review with 72 references of boosted glow discharges for atomic spectroscopy including their use as primary sources in AAS Leis and Steers (94/3366) described the different types of such sources now known and illustrated their fundamental properties with specific examples.The review is particularly valuable because the amount of work published in this field is limited. Boosting can be achieved with an auxiliary discharge a magnetic field or by structural modifications. Lines of special analytical interest are often greatly increased in intensity though other modifications to the spectra may be complex. Analytical applications and limitations for each type of source were outlined. A series of patents concerning discharge lamps for A A was filed in Russia in 1992 and 1993. An electrode-free HF discharge lamp using a quartz-glass bulb filled with an inert gas was the subject of one of these (94/3082).It seems that some line background ratios may be improved by using ‘transition glass’ as the bulb material. Spectral gas discharge lamps were covered by two further patents (94/3081,95/123). However the descrip- tions of the lamps appear to be quite complicated and their operation equally so. No indications of possible analytical performance were given. Niemax and co-workers continued with their investigations into the application of diode lasers to AAS. Schnurer-Patschan et al. (94/2201) reported on the improved detection limits obtained in single-element ETAAS measurements by applying wavelength modulation techniques. The use of wavelength modulation reduced the influence of various sources of noise on the absorption signal. These workers found that the low absorbances that can be handled by modulation techniques allowed laser AAS measurements of either weak transitions from ground states or strong transitions from thermally popu- lated excited states to compete readily with traditional AAS measurements from atomic ground states. The laser radiation was detected with either a photodiode or photo-multiplier. For La and Rb measurements were made by absorption of the fundamental diode laser radiation at 670.95 and 780.03 nm from excited and ground states respectively whereas A1 was measured by deep blue light at 396.15 nm produced from the second harmonic generation of diode laser radiation in a lithium iodate crystal.Detection limits (3s) based on the total noise were found to be 0.1 ng ml-’ 7.5 ng ml-I and 1 pg ml-’ for Al La and Rb respectively.1.4.2. Continuum source and simultaneous multi-element AAS Although the principles of continuum source and of multi- element AAS are most usually combined in one instrument an interesting ‘inverse polychromator’ approach has been described by Kitagawa et a!. (95/30). The idea is not new of course more than 25 years ago Mavrodineanu and Hughes (Appl. Opt. 1968 7 1281) constructed a double polychromator system arranged back-to-back so that resonance radiation from a number of sources placed around the focal curve of one polychromator were combined into a single beam to pass through the sample then re-dispersed in the second polychrom- ator. Kitagawa (95/30) used the first polychromator but dis- pensed with the second by modulating the sources at different frequencies then detecting with a single PMT.Individual signals were then discriminated by means of fast Fourier transformation. Analytical performances were evaluated for simultaneous measurement of 10 elements in test solutions and in real samples. A technical breakthrough of considerable interest is described in detail by Shuttler et al. (94/C3430). This is the SIMAA 6000 from Perkin-Elmer the first simultaneous multi- element electrothermal atomic absorption system to be com- mercially available. Up to six elements can be measured using four single or multi-element line sources. The system also incorporates a stabilized temperature platform furnace longi- tudinal Zeeman-effect background correction and an echelle optical system with a custom-made solid state detector array.There are claimed to be no sacrifices in sensitivity or accuracy as compared with a single-element system. Radiation from the sources is combined in a tetrahedral prism before passing through the THGA. The monolithic detector incorporates diodes located at the line positions of the 38 most important AA elements and includes a number of secondary lines. The instrument is fully controlled from a PC using a Windows- based software package which includes analytical quality control protocols. The alternative approach to multi-element AA i.e. a con- tinuum source followed by polychromator and photodiode array detection has received more attention in several groups. Smith et al. (94/2184) evaluated such a system equipped with an electrothermal atomizer getting accurate results for a number of different SRMs.The polychromator was an echelle spectrometer with easily interchangeable PMT and LPDA cartridges. It was claimed that detection limits for a number of common elements were similar with both PMT and LPDA detection. Analytically however the latter was more useful as integration of the signal across the line profile increased the linear range of the calibration curves. This point was made again by Smith this time working with Harnly (94/C1942). The graphite furnace used in the later work was capable of operation both under vacuum and at pressures up to 10 atmospheres. Atomization at elevated pressures produced a significant increase in sensitivity for a number of elements though it also caused line broadening and a shift in the absorption profile.The absorbance as measured by the CSAAS/LPDA detection system was not affected by such shifts and therefore represents an advantage over line source AAS. This work is also reported in ref. 94/C3467 (see Section 1.2.5.). Harnly and co-workers continue to explore the application of xenon arc continuum source lamps to simultaneous multi- element E TAAS. The conference presentation concerning the use of pulsed continuum sources and discussed last year (see Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 221 RJ. Anal. At. Spectrom. 1994 9 213R) has now been published (94/2948). A series of 300 and 500 W xenon arc lamps normally operated at 20 and 35 A respectively were pulsed as high as 300 W (0.5 ms pulse 3.75% duty cycle) to achieve higher intensities in combination with linear photodiode array detec- tion.Comparing dc and normal ac operation the 500 W lamp was in general a factor of 1.5 times more intense except below 210 nm where the 300 W lamp was more intense. Pulsing at high current provided a significant increase in the integrated signal from the LPDA and resulted in a factor of up to 80 times improvement in the detection limit for a new lamp. However pulsing at 200 A did induce failure of both the 300 and 500 W lamps after 10 h of operation the equivalent of about 200 atomizations. While reducing the pulse current increased the lamp lifetime there were less significant improve- ments in the detection limits. After 50 h of operation at 100 A the performance of a 300 W lamp was comparable to dc operation.In view of these findings the authors conclude that an improved lamp design is necessary before pulsing of xenon short arc lamps will be economically attractive for CSAAS instruments. Also from Harnley's group (94/C3468) came investigations on the eflects of furnace parameters on simultaneous multi- element AA measurements using THGAs. Using Pd-Mg (NO,) as matrix modifier it was established that at an atomization temperature of 2500 "C the minimum atomization temperature for V losses of Cd Cu Cr and Pb ranged from 3-34% depending on the tube arrangement (see also Section 1.2.5.). Of the two papers from Sneddon's group in Los Angeles USA the first (94/1649) was on a simultaneous theme. It described the optimization using a variable size simplex pro- cedure of the overall response of a simultaneous multi-element flame AAS.Seven instrumental parameters were subjected to the procedure for measurement of Cu Fe Mn and Zn. Although the selected conditions were necessarily a compro- mise it was found that sensitivity was in no case reduced by a factor of more than two. The second paper (94/3072) is a review with 50 references of the development performance and application of multi-element AAS covering multi- element HCLs continuum sources multichannel systems etc. 1.4.3. Background correction in AAS Further investigations into the subject of linearization ofanalyt- ical curues obtained by Zeeman-effect background corrected ETAAS have been published during the period covered by this update.A number of these were discussed in the previous Update as conference reports (see J. Anal. At. Spectrom. 1994 9,213R). L'vov et al. (94/3029) have automated their procedure whereby the dip formed in the absorbance at the pulse maxi- mum after roll-over can be corrected for. Previously the correction procedure had to be applied after operator evalu- ation of the absorption signal. A fully automated correction procedure has now been implemented. Written in BASIC the peak is first subjected to Savitzky-Golay smoothing and then searched for local maxima at a minimum height and spatial separation. The program then chooses the two largest maxima as representing the peaks on either side of the peak dip and then applies the corrections.The program was applied to the determination of Bi in the presence of a palladium chemical modifier and Ag and Cd. However problems were encountered with peaks for which a dip was barely discernible near the region where the dip first occurs. The workers proposed that this could be overcome either by repeating the determination with a smaller sample size or improving the algorithm. The work of L'vov et al. regarding the calculation of photometric error and discussed in the previous Update (see J . Anal. At. Spectrom. l994,9,213R) has now been published (Spectrochim. Acta Part B 1994 49 1609). The workers conclude that the contribution of the photometric error to the total error of analyte mass determined for moderate and large signals is insignificant and consequently the dip restoration method provides approximately the same error in mass measurement for both pre- and post- roll-over absorbance signals.They believe that the proposed theoretical approach to the evalu- ation of precision and detection limits may be considered as a new step in the development of absolute or standardless analysis as to date only parameters such as the characteristic mass and curvature of the analytical curves have been theoretically considered. Another group active in investigating the algorithm devel- oped by L'vov and co-workers for linearization of Zeeman- eflect ETAAS analytical curues is that based at the University of Connecticut. The conference report from Slavin et al. discussed last year has now been published (see J . Anal.At. Spectrom. 1994 9 213R). Su et al. (94/3070) applied the linearization approach developed by L'vov and co-workers to assess the eflect of stray light on the characteristic mass in Zeeman-effect ETAAS. The characteristic mass (mo) effective stray light (a) Zeeman-roll-over absorbance (A,) and the Zeeman-effect sensitivity ratio (R) were studied systematically as a function of lamp current and slit-width. The characteristic mass was found to be directly related to the effective stray light and the Zeeman sensitivity ratio while the Zeeman-effect roll-over absorbance was a quantitative measure of the effective stray light. By taking a and R into account a stable character- istic mass value 'm0 the 'corrected characteristic mass' was obtained. Without correction for these parameters the RSDs for measured m values were 26,20 8 and 19% for Ag Cr Cu and T1 respectively for a wide range of lamp currents and/or slit-widths.After correction for these parameters the corrected characteristic mass values were more stable with RSDs of only 7% for Ag and 4% for Cu Cr and T1. Yuzefovsky et al. (Spectrochim. Acta Part B 1994 49 1643) have refined the L'vov algorithm to include Newton's method of successive approximations to approach a solution to the theoretical expression of L'vov' and co-workers. The L'vov algorithm to linearize analytical curves is based on three parameters namely the roll-over absorbance (Ar) the limiting absorbance (Alh) and the Zeeman sensitivity ratio (R) but does not have an exact mathematical solution; rather a simplifying assumption is made that the Zeeman sensitivity ratio has a unity value and this makes it possible to linearize the analytical curves.This work introduced an additional parameter the sensitivity ratio at the rollover point (R') which was found using Newton's method and considered in the algorithm along with the roll-over absorbance. The extended algorithm and that of L'vov and co-workers were compared with analytical curves generated for Ag Bi Cu Mn and T1. For elements with relatively high R values (approximately 0.6 or greater) such as Ag Bi Mn and T1 the linearized parts of the analytical curves were practically the same for both models. The discrep- ancy in the values of the corrected characteristic mass for the linearized part of the analytical curve for both models for a large variety of experimental conditions remained within several per cent after taking the actual value of R into account in the case of the extended model or without it where R= 1 for the L'vov model. For Cu with a relatively low R value (< 0.9 the extended method improved the experimental characteristic mass value by 23% compared with the L'vov model.However it is clear from the conclusions that a major problem with the linearization models namely the accurate and reproducible measurement of the various parameters at the roll-over point may be aided by the application of the extended algorithm since the R value generally differs from 222R Journal of Analytical Atomic Spectrometry August 1995 Vol. 10unity and varies with analyte concentration for almost all elements.de Loos-Vollebregt et al. (94/2051) discussed the extension of the dynamic range that can be obtained by applying a 3-jield ac Zeeman-efect. Up to now it has generally been considered that the application of the 3-field Zeeman-effect would extend analytical curves by factor of 10. This study is the first to investigate thoroughly the use of this technique by using a commercially available transverse heated graphite atomizer with longitudinal Zeeman-effect modified to allow 3-field measurements and assessing a variety of representative elements with respect to analytical importance and Zeeman- effect splitting. At best the 3-field Zeeman-effect offers a 5-fold extension of the dynamic range. The slope of the 3-field analytical curve can also be selected by adjusting the intermedi- ate field strength. However acceptable precision of the meas- ured analyte concentrations over the increased concentration range was obtained only when the slope of the 3-field curve was reduced by a factor of about 2-3 in comparison with the corresponding 2-field Zeeman-effect analytical curves.These workers concluded that the extension of the dynamic range of the analytical curve was obtained only at the cost of less precision for the measured analyte. A new contributor to the field of extending the analytical dynamic range was Harnly (94/C3452) who provided a timely theoretical consideration of calibration for Zeeman-effect back- ground corrected ETAAS applying either normal linearized or 3-field methods.Computer modelling was applied to com- pare the working ranges and relative concentration errors (inverse of the S/N ratio) for all three methods. For peak absorbance measurements all three methods had approxi- mately the same relative errors although the 3-field method offered a slight advantage when the most sensitive analytical curve approached a maximum absorbance. For integrated absorbance measurements the linearized method was found in theory to extend the analytical curve by at least 1.5 orders of magnitude compared with the other two methods. However it is clear that this study from a theoretical consideration of the errors obtained from generating the signals and the correc- tion procedures which will limit how far the procedures can be applied does not find the large increases in dynamic range that have been previously claimed by the proponents of the linearization procedure.It is to be hoped that this material will eventually be published and contribute to the debate about the viability of linearizing analytical curves. In further considering the theoretical aspects of Zeeman- effect AAS instruments and the effects of various instrumental parameters on the linearity of analytica2 curves Voigtman et al. (Spectrochim. Acta Part B 1994 49 1629) have modelled a transverse Zeeman-effect background corrected ETAAS spec- trometer using a polychromatic optical calculus simulation software program. The behaviour of the analytical curves in the presence of three different types of stray light was modelled. Similar ‘modelled’ curves to those found by experiment were obtained.From the initial results it seems most likely that the major source of stray light in real Zeeman-effect measurements is due to the polychromaticity of the light source even when the light source is relatively narrow in spectral bandwidth. The workers intend to examine with the aid of this model how a sound theoretical basis can be established for roll-over dip correction and linearization algorithms. Stephens (94/3 103) described a field-on-source design for Zeeman-effect background correction. Although conventional Zeeman-effect background correction systems use magnetic fields applied around the atomizer this has the disadvantage that the magnet must be big enough to produce a suitably strong field in the area containing the atomizer. In this work the magnet size on the specially designed source was reduced and so mounted that a stable dc discharge could be maintained.As the magnetic fields were essentially parallel to the optical axis over the discharge region the longitudinal Zeeman-effect (no n component and circularly polarized 0 components) was observed. In order to use this configuration with the steady field of the bar magnet a photoelastic modulator was placed in the optical path to allow selective modulation of the intensity difference between the 0 and 0- components. The system was tested with Cu and found to function with satisfactory background correction capabilities. However the occurrence of spectral interferences due to line background could be a problem in such a system.It was concluded that the need for a specially designed source is a significant disadvantage but that this could be overcome as the size of the magnet used in this study is sufficiently small that the whole assembly includ- ing the magnet can fit inside the envelope of a conventional hollow cathode lamp. A conference paper from Dulude et al. of Jarrell Ash (94/C 1948) reports further investigations of the Smith-Hieftje technique which aim at the elimination of potential dc emission interference. Methods of temporal averaging of the dc radiation before and after signal measurement were evaluated. The results were incorporated into a modified system for measuring Pb and Cd in blood and the analytical performance was discussed.Background correction in a frequency-modulated simul- taneous AAS described by Lehnert et al. (94/1633) relates to a specific instrument. Radiation from three HCLs and a deuterium lamp was combined using fibre optics passed through the flame atomizer then separated with fibre optics and interference filters. Modulation demodulation and signal selection were achieved with lock-in amplifiers. The inclusion of the deuterium lamp in this simple system apparently resulted in an efficient multi-element method applicable to the analysis of complex matrices and represents an interesting alternative to known instrumentation. A graphite furnace AAS with a ‘dual option background correction facility’ was presented as a conference paper from AT1 Unicam (94/C3479). No one single system they believe provides the unique solution for every analysis though what options are made available was not clear from the abstract.In contrast an inexpensive portable AAS using ‘near-line’ back- ground correction by monitoring two closely lying wave- lengths from the same lamp (94/C2019) has been successfully used for measuring Pb in blood at the ppb level. 1.5. Instrument Control and Data Processing 1.5.1. Instrument control ‘News on fundamental reference data’ is the title of a review with 12 references (94/3140) of recent publications on this aspect of atomic spectroscopy. Rapid repetitive scanning of spectrometer pass wavelengths using a rotating 10mm quartz cube is described by McNeill et al (94/2544). The width of scan achieved was much larger than the spectrometer bandpass.Scanning frequencies greater than 300 Hz were possible. The output waveform was computer processed and displayed using software written in TURBO PASCAL. Designing AA instrument control software that works would seem to be a desirable and basic objective of any reputable instrument manufacturer and a joint paper on this subject from Perkin-Elmer and Cognetics Corporations (94/C1936) discusses the problems that a team designing user interfaces needs to solve in order to assure convincing performance. To deal with the complexity of those problems the team members need very diverse skills including chemistry graphics cognitive psychology communications and computer programming and the ability to interpret requirements voiced at customers’ group discussions and training courses or suggested by experience of Journal of Analytical Atomic Spectrometry August 1995 Vol.10 223Rprevious versions of software and instrumentation. This is an iterative process the result of which in this particular instance is an effective Windows-based system which has better capabili- ties yet is easier to use than earlier systems because of the emphasis on ‘usability engineering’ in its design. 1.5.2. Data processing All the papers in this section originated in China. Two happily were published in English language journals. The first of these claimed that a computer program of general applicability AAS-TOOLS (94/3102) facilitates ( i ) fitting and filtering of analytical data; ( i i ) on-line data collection in a specific analysis; ( i i i ) determination of kinetic parameters for a specific element; and (iv) theoretical simulation of an AAS signal based on an exponentially modified Gaussian function.It was used in conjunction with a PE 4000 AAS with deuterium-lamp back- ground correction and an HGA 400. The work aimed to present integrated software for on-line data collection and processing and to provide algorithms that are concise and as widely valid as possible. Analysis without calibration curves for the measurement of In using ETAAS was the subject of the second paper (95/270). The characteristic mass values for furnace wall platform and boat were compared at 1600-2400 “C. Satisfactory results were claimed for In in standard and geological reference materials. A third Chinese paper (this time not available in English 95/280) described an experimentally designed simplex optimiz- ation method which was claimed to be simpler more reliable and more accurate than the common orthogonal experimental design. The method was recommended when there were many factors to be considered and especially when there were significant cross effects between them.As so often happens with abstracts from Chinese papers no detail is available and so it is difficult to see in what way there can be an improvement over the simplex systems now commonly used by western researchers. 1.5.3. Chemometrics Chemometrics is the application of advanced statistical and mathematical techniques to the field of analytical chemistry. Inexpensive but powerful microcomputers will become it is said in an American environmental review (95/120) a standard part of the coming generation of analytical instruments.Sophisticated pattern recognition algorithms can be incorpor- ated into such instruments liberating them from the laboratory and turning them into ‘smart analysers’ for a variety of chemical identification quantification control and alarm tasks. Various types of on-line and in situ instrumentation were quoted. Although AAS and AFS specifically were absent from the list they could well have been included because as it is suggested these developments will permit better control and in particular a closer degree of monitoring of potential sources of pollution by enforcement agencies and the like. A conference paper from Varian (94/C1935) described new generation automated real time quality control software for the validation of data in AAS.Thirteen tests each with its own selectable limits could be programmed. Practical appli- cations to both flame and furnace atomization methods were discussed. The concept of self-monitoring systems based on the extended Kalman filter has been applied to ETAAS by Wienke et al. from Nijmegen (94/2044). The method was based upon on-line state estimation by the Kalman filter extended by quality control sampling. Advantages of the proposed method over conventional approaches were that it performed simul- taneous calibration and recalibration detection and correction of drift and detection and repair of outliers. It also required only a minimal number of QC samples for parameter updating as compared with the existing Kalman filter algorithm.An analytical procedure with ETAAS was validated after exhaustive testing. From Penninckx et al. in Brussels (94/C3434) come details of a ‘knowledge-based‘ computer system which assists vali- dation of AAS methods by detection of matrix interferences. The method was based on comparison of the slopes of standard additions and aqueous standard calibrations. As in practice these slopes are evaluated from a limited number of experi- ments there is always some probability that a significant difference may not be detected. In the system described this probability was shown to be acceptably small. The method was run using Windows software. 2. ATOMIC FLUORESCENCE SPECTROMETRY Each year a limited number of reports incorporating AFS are received for inclusion in this section of ‘Updates’ however the technique has not achieved the widespread acceptance enjoyed by its rival spectroscopic techniques despite 30 years of elo- quent advocacy by its supporters.It is therefore reasonable to conclude that it is unlikely that the technique will ever become widely used. There are however some analyses e.g. determi- nation of hydride forming elements in environmental samples for which AFS is well suited. Reviews of AFS analyses have been published by Stockwell and Corns (94/2684) and Guo (94/2627). Commercial AFS detectors suitable for the determination of As Hg and Se species when separated by chromatography have also been described (94/C203 1). 2.1.Discharge Lamp-excited Atomic Fluorescence Several methods of atomizing samples for AFS analysis have been examined. The simplest approach was that used for the determination of Hg in sediments (94/C3490). A small sample was heated in a quartz tube and the released Hg trapped prior to its rapid release into the AF detector. The method proved to be simple reliable and accurate. A most comprehensive review of the use of the ICP in AFS has been prepared by Greenfield (94/2969 94/C3426). Three systems were con- sidered; the ICP as ( 1) light source (2) atomizer (3) light source and atomizer. The advantages and limitations of these systems were fully examined and compared with those of AAS and AES. The author concludes that there is a place for ICP-AFS but it is unlikely to be generally exploited until commercial systems are established as viable.In the meantime in-house combinations of ICP and atomizer systems may be used to further define the benefits of ICP-AFS. A microwave plasma torch has been evaluated as an atomizer ofAg As Cd Fe Hg Mg Mn Pb and Zn for AFS determination (94/1622,94/3044). The detection limits for Cd and Zn were 0.26 and 1.2 pg l-l respectively. A spiral tungsten atomizer has been constructed for the determination of trace impurities in micro-volume liquid samples (94/2106). The LODs for Ag Bi Cd Cu Mn Pb and Zn ranged from 1 ng 1-’ to pg 1-’ in 2 p1 samples. The glow discharge (GD) has been shown to be a useful atom source for the direct sputtering of solid samples for AFS (94/3271). A xenon arc lamp and xenon flash-lamp were used as excitation sources and gave an improved S/B ratio for GD-AFS compared with GD-AES.The S/B was further improved by pulse operation of both the GD and the flash- lamp; the pulsing of the latter being delayed by 3 ms after completion of the GD pulse. 2.2. Laser-excited Atomic Fluorescence Lasers are used in atomic spectroscopy not only as excitation sources in AFS but also to atomize and ionize the analyte and as a diagnostic tool to probe atom vapours. Two reviews have examined these broader aspects of laser usage (94/2060 224 R Journal of Analytical Atomic Spectrometry August 1995 Vol. 1094/2068) while a third (95/147) has considered the potential uses of a new generation of semi-conductor diode lasers in atomic and molecular spectroscopy.As in all atomic spectroscopies the production of the atomic uapour for AFS is a key step in achieving sensitive and accur- ate analysis and consequently stimulates research activity. Electrothermal atomizers are currently popular devices for use with LEAFS. The operation of a graphite furnace at reduced pressure ( x 100 mTorr) for the determination of Co P Pt and Te in solid samples (nickel alloys and glass) has been investi- gated by Lonardo et al. (94/C1949). Though interferences were reduced and peak shape improved there was a decrease in sensitiuity of 2 orders of magnitude which was attributed to the use of low pressure. Other workers have developed an electrothermal atomizer in which the sample uapour remains in the atomizer for up to 10 min thereby facilitating the sequential determination of Fe Ni and Co (94/3092).A capacitive dis- charge heatedfurnace has been investigated as an atomizer for the determination of T1 (94/1853). An LOD of 5 fg of T1 was obtained with a laser repetition rate of 500Hz and peak integration time of 80 ms. Using this system TI was determined in NIST biological samples at levels of 1-2 orders of magnitude below those obtained with ETAAS with a precision of 8-20%. A laser system has been developed for the ETAFS determi- nation of As and Se in blood samples (94/2951). The system which generated radiation in the VUV region consisted of two dye lasers pumped by a Nd:YAG laser the output radiations were frequency doubled by a non-linear optical KDP crystal and sum frequency mixed by a BBO crystal.The LODs were 54 fg As and 15 fg Se using 10 p1 aliquots. Graphite furnace AFS has been demonstrated to be suitable for the determi- nation of trace elements in sea-water and polar ice. Lead was determined directly in sea-water without separation concen- tration or the addition of a chemical modifier (94/2931). The practical detection limit was 3 fg of Pb. Cobalt in sea-water required preconcentration (95/311). A bonded silica column with octadecyl functional groups (CIS) was used and gave a concen- tration factor of 12.5; the detection limit in ocean water RMs was 1.0 ng 1-’. Detection limits lower than those of other analytical methods have been reported by Daskin et al. (94/3039) for the determination of Si in high purity indium when the solid sample was atomized in a planar magnetron discharge.Laser excited molecular Juorescence has been used by Michel and co-workers to determine C1(94/2960) and F (95/312). For the determination of C1 mixed solutions of indium and C1 in an elemental ratio between 100 and 1OOO 1 were placed on a L‘vov platform in the furnace. Indium monochloride was believed to be formed at the vaporization stage. Fluorescence was excited at 267.21 nm and detected at 269 nm to give an LOD of 1Opg C1. In the determination of F an earlier study by Butcher et al. (J. Anal At. Spectrom. 1991 6 9) found that barium when added to excess magnesium promoted the forma- tion of magnesium monofluoride and enhanced the sensitivity 100-fold. The purpose of the present work (95/312) was to elucidate the mechanism of the barium enhancement.Theoretical and experimental observations suggested that barium changed the mechanism of MgF formation by forming BaF as the first stage of the reaction during the heating process to be followed at a higher temperature by the appearance of Mg from the thermal decomposition of MgO and of F from BaF,. 2.3. Studies of Flames Plasmas and Atomic Vapours using Laser-induced Fluorescence A technique for obtaining a temporally resolved two-line NO temperature image of a complex combustion-related flow field has been described (94/2992). The temperature measurements were obtained with two lasers and two intensified cameras with a two-line ratio of planar laser-induced fluorescence from NO seeded either in the fuel jet or in both the jet and cross flow.Factors affecting the accuracy of the measurement were studied in depth. The OH density in an atmospheric air furnace has been studied by means of LIF of the OH radical (94/2994). The measured OH density was found to agree well with the computed OH chemical equilibrium density over a temperature range of 1500-1850K. The system could be used for the calibration of OH measurements. A computer controlled time-resolued laser-induced breakdown spectrometer has been used by Nemet et al. (95/148) to measure the plasma emission and fluorescence of ores metals and alloys. A review of the properties ofthe hollow cathode discharge as revealed by LIF and high-resolution spectra has been published (95/87). Previously undetected spectral lines were found spontaneous emission branching ratios were measured and other fundamental atomic processes studied.Omenetto (94/2062) has reviewed the use ofLIF and LEI as tools for the study of atomic and molecular reseruoirs. Although each technique has in itself many attractive analytical and diagnostic capabilities their interaction results not only in better understanding of the dynamics of the excited states but also provides new spectroscopic information and fundamental parameters of the system under investigation. High resolution spectroscopy of Rb atoms with a line-width-narrowed diode laser at 780.1 nm was used to study hyperfine spectra and magnetic field effects (94/2065). It was found that the hyperfine spectra were very sensitive to the geomagnetic field.3. LASER ENHANCED IONIZATION Two-step LEI is believed to be more sensitive and selective than one-step LEI. Su and Lin (94/2983) have examined that proposition both theoretically and experimentally. The optim- ization of a two-step system is complex as it is multifactorial. A simple theoretical model was developed to assist in the optimization process. They concluded that any enhancement of sensitivity in the two-step system was critically dependent upon second laser intensity the transition probability of the second step excitation collisional ionization rates and the transition line width. The step-wise resonant 3-photon ionization spectrum ofthe neutral Z r atom using three separately tuneable pulsed visible dye lasers has been used by Page et al. (94/2061) to probe the lifetimes of even parity levels.They found the direct ionization cross section to be <1O-”cm2 and lifetimes of the order of 10-100 ns. The analytical applications of LEI have been reviewed by Letokhov (95/40) with particular reference to trace element determination. Trace amounts of Lu (0.1 pg g-’) in geological samples have been determined by two-step laser excitation (94/2191). The sample was vaporized from a graphite crucible under vacuum. By extrapolation of the calibration curve measurements down to 0.1 ng of Lu were claimed to be possible. Epler et al. (94/2394) have combined LC and LEI to give a very sensitive method for the measurement of organolead species. The LC stage separates interferents from analytes and the great sensitivity of LEI facilitates the determination of the latter in dilute solutions after flame atomization.The method was applied to NIST SRM 1566a Oyster Tissue. A new laser ion source has been developed with a cavity made of high purity pyrolytically coated graphite (94/2678). The source achieved a 14% ionization efficiency in the trace analysis of Tc an efficient path for the resonance ionization of Sn and the determination of actinides in environmental trace analysis. Actinides have also been determined by resonance ionization following electrolytic deposition onto a rhenium substrate and thermal release (94/2723). Surface contamination of silicon by Nu was measured by laser ablation of the surface followed by LEI (95/273). The technique was applied to the Journal of Analytical Atomic Spectrometry August 1995 Vol.10 225 Rdetermination of the Na impurity flux in the edge region of a tokamak plasma by collecting Na on silicon plates placed in that zone of the plasma. The high sensitivity of LEI facilitated the analysis of single discharges. The desorbtion of H molecules from clean and sulfur-covered polycrystalline nickel was stud- ied by Pozgainer (95/158) using one-step LEI. The experiments revealed a strong rotational cooling of the desorbing molecules while the vibrational energy was similar to that of the ther- malized beam. LOCATION OF REFERENCES The full list of references cited in this Update have been published as follows 94/961-94/1264 J. Anal. At. Spectrom. 1994,9( 4) 135R-146R. 94/1265-94/1830 J. Anal. At. Spectrom.1994 9( 5) 149R-169R. 94/1831-94/2175 J. Anal. At. Spectrom. 1994,9(6) 189R-200R. 94/2176-94/2412 J. Anal. At. Spectrom. 1994,9( 7) 203R-212R. 94/2413-94/2867 J. Anal. At. Spectrom. 1994 9( 8) 249R-265R. 94/2868-94/2994 J. Anal. At. Spectrom. 1994,9( lo) 307R-312R. 94/2995-94/3279 J. Anal. At. Spectrom. 1994,9( 1 l) 307R-318R. 94/328&-94/C3502 J. Anal. At. Spectrom. 1994,9( 12) 357R-364R. 95/1-95/182 J. Anal. At. Spe,ctrom. 1995 10( l ) 1R-60R. 95/183-95/469 J. Anal. At. Spectrom 1995 10( 2) 49R-59R. Abbreviated forms of the literature references quoted (excluding those to Conference Proceedings) are given on the following pages for the convenience of the readers. The full references names and addresses of the authors and details of the Conference presentations can be found in the appropriate issues of JAAS cited above. Abbreviated List of References Cited in Update 9411047 Clin.Chem. (Washington DC) 1993,39,800.94/1272 Appl. Spectrosc. 1993,47 1222.9411360 Carbon 1993,31,273. 9411605 Anal. Chem. 1993 65 2590. 9411609 Anal. Chem. 1993 65 3098. 9411610 Anal. Chim. Acta 1993 278 189. 9411611 Anal. Chim. Acta 1993 279,241.9411612 Anal. Chim. Acta 1993 279 253. 9411615 Anal. Chim. Acta 1993,281 135. 9411616 Anal. Chim. Acta 1993 281 185. 9411622 Fenxi Huaxue 1993 21 610. 9411624 Fenxi Huaxue 1993 21 740. 9411625 Fenxi Huaxue 1993,21 745. 9411626 Fenxi Huaxue 1993 21 761. 9411628 Fenxi Huaxue 1993 21 825. 9411631 Fresenius’ J. Anal. Chem. 1993 345 475. 9411633 Fresenius’ J. Anal. Chem. 1993 346 392. 9411636 Fresenius’ J.Anal. Chem. 1993,346 550.9411639 Fresenius’ J. Anal. Chem. 1993 346 622. 9411640 Fresenius’ J. Anal. Chem. 1993 346 643. 9411642 Fresenius’ J. Anal. Chem. 1993 346 683. 9411643 Fresenius’ J. Anal. Chem. 1993 346 689. 9411644 Fresenius’ J. Anal. Chem. 1993 346 711. 9411649 Talanta 1993 40 879. 9411650 Talanta 1993 40 1077. 9411665 Anal. Lett. 1993 26 1997. 9411667 Anal. Sci. Technol. 1992 5 349. 9411689 Appl. Organomet. Chem. 1993 7 173. 9411690 Appl. Organomet. Chem. 1993 7 213. 9411729 Clin. Chem. (Washington D.C.) 1993,39,1662.94/1767 GIT Fachz. Lab. 1993,37,411.94/1785 Huanjing Baohu (Taipei) 1992 15 29. 9411806 J. Anal. Toxicol. 1993 17 196. 9411821 J. Pharm. Biomed. Anal. 1993 11,301.94/1825 Jilin Daxue Ziran Kexue Xuebao 1992,3,85. 9411838 Laboratoriumsmedizin 1992 16 419.941 1849 Muter. World 1933 1 397. 9411853 Microchem. J. 1993 47 363. 9412044 Anal. Chem. 1994,66,841.94/2049 Fresenius’ J. Anal. Chem. 1993,346,873.9412051 Spectrochim. Acta Part B 1993 48,1505.9412057 Glow Discharge Spectrosc. 1993,67.94/2060 Hwahak Sekye 1993 33 658. 9412061 Inst. Phys. Conf. Ser. 1992 128 63. 9412062 Inst. Phys. Con$ Ser. 1992 128 151. 9412065 Jpn. J. Appl. Phys. Part 1 1993 32 3291. 9412066 Lab. Rob. Autom. 1993 5 299. 9412068 Lebensm.- Biotechnol 1993,10,125.94/2106 Prib. Tekh. Eksp. 1993,2,120.94/2178 J. Anal. At. Spectrom. 1993 8 955. 9412184 J. Anal. At. Spectrom. 1993 8 989. 9412185 J. Anal. At. Spectrom. 1993 8 995. 9412186 J. Anal. At. Spectrom. 1993 8 999. 9412187 J. Anal. At. Spectrom. 1993 8 1005. 9412188 J. Anal.At. Spectrom. 1993 8 1011. 9412189 J. Anal. At. Spectrom. 1993 8 1015. 9412191 J. Anal. At. Spectrom. 1993,8 1029.9412198 J. Anal. At. Spectrom. 1993 8 1085. 9412200 J. Anal. At. Spectrom. 1993 8 1097. 9412201 J. Anal. At. Spectrom. 1993 8 1103. 9412202 J. Anal. At. Spectrom. 1993,8 1109.94/2203 J. Anal. At. Spectrom. 1993 8 1113. 9412204 J. Anal. At. Spectrom. 1993 8 1117. 9412209 J. Anal. At. Spectrom. 1994 9 1.9412210 J. Anal. At. Spectrom. 1994,9 7.9412211 J. Anal. At. Spectrom. 1994,9 11.9412215 J. Anal. At. Spectrom. 1994 9,39.94/2216 J. Anal. At. Spectrom. 1994,9,45. 9412240 Appl. Optics 1993 32 6082. 9412245 Clin. Chem. 1993 39 155. 9412249 At. Spectrosc. 1993 14 95. 9412250 At. Spectrosc. 1993 14 99. 9412254 Anal. Chem. 1993 65 1682. 9412258 Analyst (London) 1993,118 1031.9412266 Fresenius’ J. Anal. Chem. 1993,346,414. 9412275 Zh. Anal. Khim. 1993,48,648. 9412277 Zh. Anal. Khim. 1993 48 774. 9412281 Fenxi Ceshi Xuebao 1993 12 64. 9412294 J. Chromatogr. 1993 641 337. 9412298 Lihua Jianyan Huaxue Fence 1993 29 179. 9412299 Microchem. J. 1993 48 184. 9412394 J. Anal. At. Spectrom. 1994 9 79. 9412399 J. Anal. At. Spectrom. 1994 9 105. 9412400 J. Anal. At. Spectrom. 1994 9 111. 9412401 J. Anal. At. Spectrom. 1994,9 117.9412407 Fenxi Ceshi Xuebao 1993 12 5. 9412410 Fenxi Shiyanshi 1993 12 ( 5 ) 51. 9412411 Guangpuxue Yu Guangpu Fenxi 1993 13 110. 9412412 Guangpuxue Yu Guangpu Fenxi 1993 13 85. 9412544 Anal. Proc. (London) 1993,30,401.94/2547 Anal. Sci. 1993,9,447. 9412563 Bunseki Kagaku 1993 42 551. 9412565 Bunseki Kagaku 1993,42,599.94/2579 Fresenius’ J.Anal. Chem. 1993 346 1047. 9412580 Fresenius’ J. Anal. Chem. 1993 346 1058. 9412581 Fresenius ’ J. Anal. Chem. 1993 346 1062. 9412582 Fresenius’ J. Anal. Chem. 1993 346 1068. 9412587 Fresenius’ J. Anal. Chem. 1993 347 303. 9412594 Zh. Anal. Khim. 1993 48 1254. 9412595 Zh. Anal. Khim. 1993 48 1345. 9412623 Fenxi Shiyanshi 1993,12(4) 19.9412625 Fenxi Shiyanshi 1993 12(4) 63. 9412627 Fenxi Shiyanshi 1993 12(4) 92. 9412670 Inst. Phys. Conf. Ser. 1992 128 255. 9412678 Inst. Phys. Con$ Ser. 1992,128 313.9412684 J. Autom. Chem. 1993,15(3) 79. 226R Journal of Analytical Atomic Spectrometry August 1995 Vol. 1094/2697 J. Radioanal. Nucl. Chem. 1993 172 117. 94/2710 Lihua Jianyan Huaxue Fence 1993 29 265. 94/2712 Lihua Jianyan Huaxue Fence 1993 29 280. 94/2723 Muter.Res. SOC. Symp. Proc. 1992 260 157. 94/2878 Anal. Chem. 1994 66 1462. 94/2886 At. Spectrosc. 1993 14 187. 94/2888 Guangpuxue yu Guangpufenxi 1993,13(6) 100.94/2889 Lihua Jianyan Huaxue Fence 1994 30(1) 15. 94/2891 Fenxi Shiyanshi 1994 13(2) 20. 94/2892 Fenxi Ceshi Xuebao 1994 13( l) 49. 94/2899 J. Anal. At. Spectrom. 1994,9 131.94/2922 J. Anal. At. Spectrom. 1994 9 267. 94/2923 J. Anal. At. Spectrom. 1994 9 273. 9412925 J . Anal. At. Spectrom. 1994 9 285. 94/2926 J. Anal. At. Spectrom. 1994 9 291. 94/2928 J. Anal. At. Spectrom. 1994 9 303. 94/2931 J. Anal. At. Spectrom. 1994 9 315. 94/2932 J. Anal. At. Spectrom. 1994 9 321. 94/2933 J. Anal. At. Spectrom. 1994 9 333. 94/2934 J. Anal. At. Spectrom. 1994 9 337. 94/2948 J. Anal.At. Spectrom. 1994 9 419. 9412949 J. Anal. At. Spectrom. 1994 9 427. 94/2950 J. Anal. At. Spectrom. 1994 9 431. 94/2951 J. Anal. At. Spectrom. 1994 9 437. 94/2952 J. Anal. At. Spectrom. 1994 9 443. 94/2953 J. Anal. At. Spectrom. 1994 9 451. 94/2955 J. Anal. At. Spectrom. 1994 9 463. 94/2956 J. Anal. At. Spectrom. 1994 9 469. 94/2957 J. Anal. At. Spectrom. 1994 9 477. 94/2960 J. Anal. At. Spectrom. 1994 9 501. 94/2964 J. Anal. At. Spectrom. 1994 9 531. 94/2965 J. Anal. At. Spectrom. 1994 9 535. 94/2967 J. Anal. At. Spectrom. 1994 9 547. 94/2969 J. Anal. At. Spectrom. 1994 9 565. 94/2979 J. Anal. At. Spectrom. 1994 9 643. 94/2981 J. Anal. At. Spectrom. 1994 9 657. 94/2982 J. Anal. At. Spectrom. 1994,9,663. 94/2983 Appl. Spectrosc. 1994,48,241. 94/2985 Appl. Spectrosc.1994 48 273. 94/2992 Appl. Opt. 1993 32 7532. 94/2994 Appl. Opt. 1994 33 1115. 94/3000 Analyst 1993 118 1027. 94/3002 Analyst 1993 118 1417. 94/3003 Analyst 1993 118 1425. 94/3015 Fresenius’ J. Anal. Chem. 1993 346( 10-11) 882. 94/3018 Fresenius’ J . Anal. Chem. 1993 346( 10-1 l) 461. 94/3023 J. Anal. At. Spectrom. 1994 9 773. 94/3026 J. Anal. At. Spectrom. 1994 9 791. 94/3027 Spectrochim. Acta Part B 1993 48 1551. 94/3029 Spectrochim. Acta Part B 1993,48( 13) 1625.94/3030 Talanta 1993 40 1147. 94/3034 Talanta 1993 40(11) 1609. 94/3035 Talanta 1993 40( 1 l) 1677. 94/3036 Talanta 1993 40( 1 l) 1759. 94/3037 Talanta 1993 40( 12) 1829. 94/3039 Zh. Anal. Khim. 1993,48(4) 715.94/3040 Zh. Anal. Khim. 1993,48(5) 813. 94/3041 Anal. Sci. 1993 9(6) 859. 94/3044 Chin.Chem. Lett. 1993 4(7) 615. 94/3048 Fenxi Shiyanshi 1993 12(5) 47. 94/3049 Gaodeng Xuexiao Huaxue Xuebao 1993 14(7) 937. 94/3052 Guangdong Gongxueyuan Xuebao Ziran Kexueban 1991 8(4) 27. 94/3058 Inst. Phys. Conf. Ser. 1992 1218( Resonance Ionization Spectroscopy 1992) 225. 94/3070 Microchem. J. 1993 48(3) 278. 94/3072 Microchem. J. 1993 48(3) 318. 94/3073 Microchem. J. 1993 48(3) 326. 94/3081 U.S.S.R. SU 1,737,561 (Cl. HOlJ61/02) 30 May 1992 Appl. 4,813,072 12 Apr 1990. 94/3082 U.S.S.R. SU 1,737,565 (Cl. H01J65/04) 30 May 1992 Appl. 4,814,974 17 Apr 1990. 94/3083 PCTInt. Appl. WO 93 17,321 (Cl. GOlN1/34) 02 Sep 1993 AU Appl. 92/1,069 25 Feb 1992; 31 pp. 94/3092 Vysokochist Veshchestva 1993 (6) 114. 94/3100 Yejin Fenxi 1993 13(4) 55. 94/3102 J. Anal. At. Spectrom.1994 9 669. 94/3103 J. Anal. At. Spectrom. 1994 9 675. 94/3104 J. Anal. At. Spectrom. 1994 9 679. 94/3105 J. Anal. At. Spectrom. 1994 9 685. 94/3106 J. Anal. At. Spectrom. 1994 9 691. 94/3112 J. Anal. At. Spectrom. 1994 9 727. 94/3123 J. Anal. At. Spectrom. 1994 9 801. 94/3128 Anal. Chim. Acta 1994 285 53. 94/3130 Anal. Chim. Acta 1994 285 359. 94/3134 Anal. Chim. Acta 1993 283(2) 895. 94/3139 Spectrochim. Acta Part B 1993 48( 13) 1645. 9413140 Spectrochim. Acta Part B 1993 48(13) 1651. 94/3142 Talanta 1993 40(12) 1927. 94/3146 Zh. Anal. Khirn. 1993 48(12) 1906. 94/3147 Zh. Anal. Khim. 1993 48(12) 2012. 94/3155 Chem. Anal. (Warsaw) 1993 38(6) 771. 94/3156 Fenxi Shiyanshi 1993 12(6) 55. 94/3167 Labor Praxis 1993 117(4) 44. 94/3170 Microchem. J. 1994 49( l) 20.94/3175 Yankuang Ceshi 1993 12(2) 85.94/3244 J.Anal. At. Spectrom. 1994,9 857.94/3245 J. Anal. At. Spectrom. 1994 9 861. 94/3246 J. Anal. At. Spectrom. 1994 9 867. 94/3247 J. Anal. At. Spectrom. 1994 9 871. 94/3271 J. Anal. At. Spectrom. 1994 9 1039. 94/3279 Appl. Opt. 1994 33 18 3992. 94/3280 Anal. Chem. 1 Oct 1993 65(19) 2590. 94/3285 Anal. Chim. Acta 5 Oct 1993 282( l) 109. 94/3286 Anal. Chim. Acta 15 Nov 1993 283( l) 167. 94/3287 Anal. Chim. Acta 15 Nov 1993 283(1) 393. 9413288 Anal. Chim. Acta 30 Dec 1993 284(2) 361. 94/3289 Anal. Chim. Acta 20 Jan 1994,285( l) 33.94/3292 Anal. Chim. Acta 28 Feb 1994,286( 3) 343.94/3296 Anal. Proc. Mar 1994 31(3) 89. 94/3304 Appl. Spectrosc. Nov 1993 47(11) 1871. 94/3306 Bunseki Kagaku Nov 1993 42( 1 l) T147. 94/3311 Bunseki Kagaku Feb 1994 43(2) 105. 94/3317 J. Anal. At. Spectrom. Aug l994,9,213R 94/3319 Fenxi Huaxue Oct 1993 21(10) 1239. 94/3320 Fenxi Huaxue Jan 1994 22(1) 19. 94/3326 Fresenius’ J. Anal. Chem. Sep-Oct 1993 347(3-4) 82. 94/3329 Fresenius’ J. Anal. Chem. Nov 1993 347(8-9) 320-323. 94/3330 Fresenius’ J. Anal. Chem. Nov 1993 347( 8-9) 356-360. 94/3334 Fresenius’ J. Anal. Chem. 1994 348(3) 195. 94/3336 Fresenius’ J. Anal. Chem. 1994 348(3) 248. 94/3339 Fresenius‘ J. Anal. Chem. Feb 1994 348(5-6) 353. 94/3346 Spectrochim. Acta Part B 18 Oct 1993 48(12) 1495. 94/3349 Spectrochim. Acta Part B 20 Dec 1993 48( 14) 1703. 94/3360 Spectrochim. Acta Part B 25 Feb 1994 49(2) 163. 94/3363 Spectrochim. Acta Part B Mar 1994,49(3) 221. 94/3364 Spectrochim. Acta Part B Mar 1994 49(3) 229. 94/3366 Spectrochim. Acta Part B Mar 1994,49( 3) 289.95/1 Anal. Chim. Acta 1994 286 381. 9515 Fenxi Shiyanshi 1993 12 97. 95/12 Guangpuxue Yu Gangpu Fenxi 1993 13(4) 103. 95/13 Guangpuxue Yu Guangpu Fenxi 1994 14(1) 99. 95/23 Spectrosc. Lett. 1994 27 257. 95/30 Anal. Sci. 1993 9 663. 95/32 Anal. Sci. 1993 9 707. 95/33 Anal. Sci. 1993 9 723. 95/38 Asian J. Chem. 1993 5 1047. 95/39 Asian J. Chem. 1993 5 1078. 95/40 Ber. Bunsen.-Ges. Phys. Chem. 1993 97 1512. 95/41 Analusis 1994,22 37. 95/43 Bull. Chem. SOC. Jpn. 1993 66 2233. 95/55 Dojin News 1993 66 3. 95/56 Fenxi Ceshi Xuebao 1993,12 1. 95/66 Fenxi Shiyanshi 1994,13( l) 90. 95/80 Guangpuxue Yu Guangpu Fenxi 1993 13(1) 121. 95/82 Guangpuxue Yu Guangpu Fenxi 1993 13(3) 51. 95/83 Guangpuxue Yu Guangpu Fenxi 1993 13(3) 57. 95/87 Guangpuxue Yu Guangpu Fenxi 1993. 13(4) 23. 95/101 J. Autom. Chem. 1993 15 37. 951111 Jpn. J. Appl. Phys. Part 1 1993 32 5717. 95/112 J. Radioanal. Nucl. Chem. 1993 174 133. 95/118 Int. J. Enuiron. Anal. Chem. 1993 52 195. 95/119 Int. J. Environ. Anal. Chem. 1993 51 219. 95/120 Int. SAMPE Environ. Cons. 1991 l(Environment in the 1990’s A Global Concern) 290. 95/123 U.S.S.R. SU 2,804,597 (CI. GO1 J3/2O) 23 Mar 1993 Appl. 4,891,880 1993 ( l l ) 226. 95/124 Keikinzoku 1993 43 353. 95/126 LaborPraxis 1993 17( 8 ) 12. 95/135 Lihua Jianyan Huaxue Fence 1994 30(1) 26. 95/147 Proc. SPIE-Int. SOC. Opt. Eng. 1992,1711,197.95/148 Proc. SPIE-Int. SOC. Opt. Eng. 1993 1983 977. 95/152 Pure Appl. Chem. 1993 65 2465. 95/153 Quim. Anal. (Barcelona) 1993,12,30.95/158 Surf. Sci. 1994,307-309,344.95/163 Ukr. Khim. Zh. (Russ. Ed.) 1993 59 618. 95/165 Yankuang Ceshi 1993 12(2) 101. 95/174 Zavod. Lab. 1993,59 25. 95/182 Zh. Prikl. Spektrosk. 1993,58 560. 95/190 Anal. Chim. Acta 1993 284 367.95/191 Anal. Chim. Acta 1994,285,277.95/192 Anal. Chim. Acta 1994 287 247. 95/194 Anal. Proc. 1994 31 61. 95/199 Bunseki Kagaku 1994,43,169.95/200 Bunseki Kagaku 1993 42 767. 95/202 Fenxi Huaxue 1993 21 1258. 95/210 Anal. Sci. 1994 10 281. 95/216 Chem. Anal. (Warsaw) 1993 38,759.95/220 Diqiu Kexue 1993,18,810.95/224 Fenxi Ceshi Xuebao 1993 12(4) 32. 95/231 Guangpuxue Yu Guangpu Fenxi 1993 13 121. 95/235 Guangpuxue Yu Guangpu Fenxi 1993 13(5) 85. 95/241 Guangpuxue Yu Guangpu Fenxi 1994 14( l) 91,42.95/244 Spectrochim. Acta Part B 1993,48 1633. 95/245 Spectrochim. Acta Part B 1993 48 1639. 95/250 Spectrochim. Acta Part B 1993 48 1719. 95/252 Talanta 1993 40 1839. 95/253 Talanta 1994 41 67. 95/254 Talanta 1994 41 371. 95/255 Zh. Anal. Khim. 1994 49 150. 95/256 Zh. Anal. Khim. 1994 49 157. 95/260 Zh. Anal. Khim. 1994 Journal of Analytical Atomic Spectrometry August 2 995 Vol. 10 227 R49 361. 95/270 Mikrochim. Acta 1994 112 237. 95/273 Opt. Eng. (Bellingham Wash.) 1993 32 2487. 951277 Spectrosc. Lett. 1994 27 353. 95/280 Xibei Daxue Xuebao Ziran Kexueban 1993 23 109. 95/282 Yankuang Ceshi 1993 12( l ) 6. 95/283 Yankuang Ceshi 1993 12(1) 14. 951286 Yankuang Ceshi 1993 12(1) 57. 951291 Zhongguo Xitu Xuebao 1992 10 183. 951300 J. Anal. At. Spectrom. 1994 9 1129. 95/302 J. Anal. At. Spectrom. 1994 9 1143. 95/303 J. Anal. At. Spectrom. 1994 9 1153. 95/304 J. Anal. At. Spectrom. 1994 9 1161. 95/305 J. Anal. At. Spectrom. 1994 9 1167. 95/306 J. Anal. At. Spectrom. 1994 9 1173. 95/307 J. Anal. At. Spectrom. 1994 9 1177. 95/311 J. Anal. At. Spectrom. 1994 9 1195. 95/312 J. Anal. At. Spectrom. 1994 9 1203. 95/321 J. Anal. At. Spectrom. 1994 9 1255. 95/322 J Anal. At. Spectrom. 1994 9 1263. 951324 J. Anal. At. Spectrom. 1994 9 1273. 951325 J. Anal. At. Spectrom. 1994 9 1279. 95/327 J. Anal. At. Spectrom. 1994 9 1289. 95/331 Can. J. Appl. Spectrosc. 1994 39(2) 54. 951333 Can. J. Appl. Spectrosc. 1994 39(3) 61. 951334 Anal. Chim. Acta 1994 294 185. 95/338 Anal Chim. Acta 1994 287 17. 951344 Talanta 1994 41 195. 951345 Talanta 1994 41 205. 951349 Anal. Lett. 1994 27 411. 95/369 Clin. Chem. (Washington D.C.) 1994 40 602. 95/373 Commun. Soil Sci. Plant Anal. 1994 25 1149. 95/391 Guangpuxue Yu Guangpu Fenxi 1993 13(4) 97 92. 95/396 Guangpuxue Yu Guangpu Fenxi 1993 13(5) 103. 95/398 Guangpuxue Yu Guangpu Fenxi 1994 14(1) 85 98. 95/399 Guangpuxue Yu Guangpu Fenxi 1994,14( 1). 95.95/402 Hebei Daxue Xuebao Ziran Kexueban 1993,13(2) 34.951412 J. AOAC Int. 1993 76 1400. 95/414 J. AOAC Int. 1994 77 441. 951419 J. Dairy Res. 1994 61 83. 95/435 Microchem. J. 1994 49 69. 951437 Microchem. J. 1994 49 275. 951438 Microchem. J. 1994 49 282. 951445 Pochuouedenie 1993 (8) 118. 951450 Quim. Anal. (Barcelona) 1992 11 35. 95/451 Quim. Anal. (Barcelona) 1992 11 55. 95/456 Sendai-shi Eisei Kenkyushoho 1992 (Pub. 1993) 22 226. 95/457 Shanghai Huanjing Kexue 1993 12( l) 31. 228 R Journal of Analytical Atomic Spectrometry August 199.5 Vol. 10

ISSN:0267-9477    

DOI:10.1039/JA995100199R

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

9512276 9512277 9512278 9512279 9512280 9512281 9512282 9 5/22 8 3 9 512284 9512285 9512286 9512287 9512288 9512289 9512290 Ghazi A. M. Lead in archaeological samples an isotopic study by ICP-MS. Appl. Geochem. 1994 9 627. (Dept. Geol. Univ. Nebraska-Lincoln Lincoln NE 68588 USA). Kir’yanov G. I. Titov V. V. Inductively coupled plasma mass spectrometry of inorganic trace impurities in high-purity water. At. Energ. 1994 77 134. (VNIITFA Russia). Cairns W. R. L. Ebdon L. Hill S. J. Development of an HPLC-ICP-MS method for the determination of platinum species from new anti-tumour drugs. Anal. Proc. (London) 1994 31 295. (Dept. Environ. Sci. Univ. Plymouth Devon UK PL4 8AA). Denoyer E. R. Optimization of transient signal measurements in ICP-MS. At. Spectrosc. 1994 15 7. (Perkin-Elmer Corp.Norwalk CT 06859-0215 USA). Kallio E. Experiences in the (ICP-MS) analysis of geological and environmental samples. Kern.-Kemi 1994 21 120. (Kemian Lab. Geol. Tutkimuskeskus Espoo Finland). Selby M. Approaches to interference-free elemental analysis with ICP-MS. At. Spectrosc. 1994 15 27. (Centre Instrum. and Develop. Chem. Queensland Univ. Technol. Brisbane 4001 Australia). Kittel N. E. V. D. Seuvert A. Wuensch G. Analysis for trace metals in high-purity refractory metals with matrix separation. An. Quim. 1994 90 116. (Inst. Anorg. Chem. Univ. Hannover 30167 Hannover Germany). Paul M. Analysis of solid samples by laser sampling ICP-MS. At. Spectrosc. 1994 15 21. (ICP-MS Dept. Bodenseewerk Perkin-Elmer GmbH D-88647 Uberlingen Germany). Nowinski P.Hodge V. Evaluation of ICP- MSImicrowave oven preparation for the rapid analysis of ore samples for gold and the platinum-group metals. At. Spectrosc. 1994 15 109. (Reynolds Elec. and Eng. Co. Inc. Las Vegas NV 89193 USA). Durrant S. F. Feasibility of improvement in analytical performance in laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) by addition of nitrogen to the argon plasma. Fresenius’ J. Anal. Chem. 1994 349 768. (Dept. Chem. Univ. Surrey Surrey UK GU2 5XH). Richter S. Ott U. Begemann F. Multiple ion counting in isotope abundance mass spectrometry. Int. J. Mass Spectrom. Ion Processes 1994 136 91. (Max-Planck- Inst. fur Chem. (Otto-Hahn Inst.) D-55020 Mainz Germany). Merritt D. A. Hayes J. M. Nitrogen isotopic analyses by isotope-ratio-monitoring gas chromatography/mass spectrometry.J. Am. SOC. Mass Spectrom. 1994 5 387. (Depts. Chem. and Geol. Sci. Indiana Univ. Bloomington IN 47405-1403 USA). Greb U. Rottmann L. Interference-free trace element analysis by inductively coupled plasma mass spec- trometry (ICP-MS). LaborPraxis 1994 18 42. (Finnigan MAT GmbH D-28197 Bremen Germany). Stefanova V. Kmetov V. Futekov L. Pulse techniques for sample introduction in the inductively-coupled- plasma mass spectrometry. Anal. Lab. 1993 2 159. (Dept. Chem. Univ. Plovdiv 4000 Plovdiv Bulgaria). Valkiers S. Schaefer F. Becker M. Wouters L. De Bievre P. Near-absolute gas (isotope) mass spec- trometry Isotope abundances (and atomic weight) 951229 1 9512292 9512293 9512294 9512295 9512296 9512297 9512298 9512299 9512300 9 51230 1 9512302 determinations of sulfur.Process Technol. Proc. 1994 11 945. (Inst. Ref. Mater. and Measure. Comm. Eur. Commun.-JRC B-2440 Geel Belgium). Valkiers S. Schaefer F. De Bievre P. Near-absolute gas (isotope) mass spectrometry Isotope abundance (and atomic weight) determinations of neon krypton xenon and argon. Process Technol. Proc. 1994 11 965. (Inst. Ref. Mater. and Measure. Comm. Eur. Commun.- JRC B-2440 Geel Belgium). Naohara J. Satou A. Kawasaki N. OOnishi S. Yamashita E. Ishii T. Shige Y. Determination of trace elements in environmental sample by ICP-MS. (2) Analysis of trace elements in biological reference materials (NIES tea leaves) using ICP-MS. Okayama Rika Daigaku Kiyo A 1993 29 139. (Environ. Resour. Res. Centre Okayama Univ.Sci. Okayama 700 Japan). Moore J. A. Elsahlli T. Measurement of composition of thin films obtained by sputtering using radioisotope excited X-ray fluorescence. X-Ray Spectrom. 1994 23 155. (Dept. Phys. Brock Univ. St. Catharines Ontario Canada L2S 3A1). Lankosz M. Pella P. A. Analytical algorithm for correction of edge effects in X-ray microfluorescence analysis of geological samples. X-Ray Spectrom. 1994 23 169. (Fac. Phys. and Nucl. Tech. Univ. Mining and Metall. al. Mickiewicza 30 Krakow Poland). Faulkner R. G. Morgan T. S. Little E. A. Analytical electron microscopy of thin segregated layers. X-Ray Spectrom. 1994 23 195. (Inst. Polymer Technol. and Mater. Eng. Loughborough Univ. Technol. Loughborough Leics. UK LE11 3TU). Wang F. C.-Y. Submicrometer phase chemical composi- tion analysis with an electron probe microanalyzer.X - Ray Spectrom. 1994 23 203. (Anal. Sci. Lab. Michigan Div. The Dow Chem. Co. Midland MI 48667 USA). Mann K. S. Singh N. Mittal R. Sood B. S. Allawadhi K. L. Ll La Lp and Ly X-ray production cross-sections in elements 57 5 2 S 92 by 8-50keV photons. X-Ray Spectrom. 1994 23 208. (Nucl. Sci. Labs. Phys. Dept. Punjabi Univ. Patiala- 147002 Punjab India). Morse M. A. Chlorine determination in photographic developer solutions using wavelength-dispersive X-ray fluorescence. X-Ray Spectrom. 1994 23 218. (Anal. Technol. Div. Build. 49 Eastman Kodak Co. Rochester NY 14652-3712 USA). Pavlinsky G. V. Dukhanin A. Y. Calculation of photo- and Auger electron contribution to X-ray fluorescence excitation of elements with low atomic number.X-Ray Spectrom. 1994 23 221. (Inst. Appl. Phys. State Univ. Gagarina St. 20 664003 Irkutsk Russia). Stoev K. N. Study on journal distribution of publi- cations in the field of X-ray fluorescence analysis. X-Ray Spectrom. 1994 23 229. (Environ. Canada Environmental Technol. Center 3439 River Rd. Ottawa Ontario Canada K1A OH3). Acharya B. S. Sakthivel R. Electronic structure and L X-ray emission spectra of molybdenum carbide boride nitride silicide and silicocarbide. X-Ray Spectrom. 1994 23 236. (Reg. Res. Lab. Bhubaneswar-751013 India). Pires Valente A. L. Uden P. C. Comparison of a combined helium-argon plasma with pure helium plasmas for gas chromatography with atomic emission detection. Analyst (Cambridge UK) 1995 120 419. (Dept.Chem. Lederle Grad. Res. Tower A Univ. Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 229R9512303 9512304 9512305 9512306 9512307 9512308 9512309 9512310 951231 1 9512312 95/23 13 9512314 9512315 230 R Massachusetts Box 34510 Amherst MA 01003-4510 USA). Matni G. Azani R. Van Calsteren M. R. Bissonnette M. C. Blais J. S. Determination of free selenomethion- ine in nutritional supplements by high-performance liquid chromatography coupled with thermochemical hydride generation atomic absorption spectrometry. Analyst (Cambridge UK) 1995 120 395. (Macdonald Campus Dept. Food Sci. and Agric. Chem. McGill Univ. 21 11 1 Lakeshore Rd. Ste-Anne-de-Bellevue Quebec Canada H9X 3V9). Karel J. Oestman C. Haakan C. Bemgaard A. Colmsjoe A. Instrument-induced effects in the analysis of polycyclic aromatic compounds by capillary gas chromatography with atomic emission detecton (GC-AED). J.High Resolut. Chromatogr. 1994,17 135. (Dept. Anal. Chem. Natl. Inst. Occup. Health S-171 84 Solna Sweden). Okujeni C. D. Funtua I. I. Geochemical and gamma spectrometric analysis of ores and host rocks of the Kanawa uranium occurrence in NE Nigeria. J. Radioanal. Nucl. Chem. 1994 178 375. (Dept. Geol. Ahmadu Bello Univ. Zaria Nigeria). Solano G. Katz S. A Holzbecher J. Chatt A. Attempt to prepare and characterize a soil reference material for Cr(V1) and Cr(II1). J. Radioanal. Nucl. Chem. 1994 179 173. (Dept. Chem. Rutgers Univ. Camden NJ 08102-1205 USA). Van Elteren J. T. Das H. A. Deligny C. L. Agterdenbos J. Bax D. Arsenic speciation in aqueous samples using a selective As(III)/As( V) precon- centration in combination with an automatable cryotrapping hydride generation procedure for mono- methylarsonic acid and dimethylarsinic acid.J. Radioanal. Nucl. Chem. 1994. 179 21 1. (Netherlands Energy Res. Found. 1755 ZG Petten Netherlands). Fisher G. F. Bennett L. G. I. Quantitative filter debris analysis (QFDA) as a means of monitoring wear in oil- lubricated systems. J. Radioanal. Nucl. Chem. 1994 180 121. (Dept. Chem. Chem. Eng. R. Mil. Coll. Canada Kingston Ontario Canada). Frontasyeva M. V. Nazarov V. M. Steinnes E. Moss as monitor of heavy metal deposition comparison of different multi-element analytical techniques. J. Radioanal. Nucl. Chem. 1994 181 363. (Jt. Inst. Nucl. Res. Frank Lab.Neutron Phys. Dubna 141980 Russia). Zheng Y. Guo C. Duan Y. Yang W. Use of partial least-squares method for correction of spectral inter- ference in flame atomic absorption spectrometry. Jilin Daxue Ziran Kexue Xuebao 1994,1,119. (Dept. Chem. Jilin Univ. Changchun 130023 China). Uemoto M. Koshimura H. Matrix interferences in (ICP) atomic emission spectrometry. Determination of trace precious metals in precious metals. Kenkyu Hokoku-Tokyo-toritsu Kogyo Gijutsu Senta 1994 23 81. (Tokyo Metrop. Ind. Technol. Center Tokyo 115 Japan). Iwasaki K. Glow discharge mass spectrometry. Kinzoku 1994,64,4. (Kanagawa High-Technol. Found. Kawasaki 2 13 Japan). Suda T. Kimura Y. Preconcentration of aluminium- 8-quinolinol complex with an ion exchange resin XAD-2. Ibaraki Kogyo Koto Senmon Gakko Kenkyu Zho 1994,29 51.(Ibaraki Natl Coll. Technol. Katsuta 312 Japan). Fujii T. Surface ionization mass spectrometry. Determination of suspended particulate matters. Kinzoku 1994 64 11. (Environ. Chem. Div. Natl. Inst. Environ. Stud Tsukuba 305 Japan). Sakakibara T. Cleanliness evaluation of environment and materials of semiconductor production process by 9512316 95/23 17 95/23 18 95/23 19 9512320 9512321 9512322 9 5/23 2 3 9512324 9 5/23 2 5 9512326 9512327 9512328 9512329 9512330 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 inductively coupled mass spectrometry (ICP-MS). Kuki Seijo 1994 32 47. (Sumika Chem. Anal. Serv. Ltd. Sodegaura 299-02 Japan). Wess J. Singer R. Reference spectrometer for simul- taneous ICP-AES (inductively coupled plasma atomic emission spectroscopy) measurements.LaborPraxis 1994,18,48. (Instrum. S.A. GmbH D-85630 Grasbrunn Germany). Fodor A. Papp L. New combined electrothermal atomization-hollow cathode excitation source. 11. Further development and analytical examination of the method. Magy. Kem. Foly. 1994,100,119. (Anal. Tansz. Babes-Bolyai Tudomanyegy. 3400 Cluj-Napoca Romania). Dass C. Mass spectrometry. Instrumentation and techniques. Mass Spectrom. 1994 2 1. (Dept. Neruol. Univ. Tennessee-Memphis Memphis TN 38163 USA). Ramakumar K. L. Rao R. M. Gnaoayyan L. Jain H. C. Simultaneous isotopic analysis of uranium and plutonium by thermal ionization mass spectrometry coupled to a variable multicollection detection system. Int. J. Mass Spectrom. Ion Processes 1994 134 183.(Fuel Chem. Div. Bhabha Atomic Res. Centre Bombay 400 085 India). Kobayashi T. Study of ultra-trace analysis by graphite furnace atomic absorption spectrometry. Materia 1994 33 313. (Natl. Res. Inst. Met. Tokyo 153 Japan). Fujimoto K. Matsumura Y. Ultra-trace analysis and determination limit by inductively coupled plasma atomic emission spectroscopy (ICP-AES). Materia 1994 33 319. (Anal. Mater. Sci. Res. Center Kawasaki Steel Corp. Chiba 260 Japan). Mochizuki T. Laser ablation for direct analysis of solid samples by inductively coupled plasma mass spec- trometry. Materia 1994 33 325. (Appl. Technol. Res. Center NKK Corp. Kawasaki 210 Japan). Kubota M. Inductively coupled plasma mass spec- trometry using sample introduction technique of solu- tion.Muteria 1994 33 330. (Matl. Inst. Mater. Chem. Res. Tsukuba 305 Japan). Schnoes M. L. Harris T. D. Pearton S. J. Di Giuseppe M. A. Bhat R. Cox H. M. Reliable impurity identification in InP. Muter. Res. SOC. Symp. Proc. 1994 325 113. (AT & T Bell Lab. Murray Hill NJ 07974 USA). Boehm H. Optimization and control of thermochemical processes by a glow discharge spectrometer. Metal1 (Heidelberg) 1994 48 472. (Spectrosc. Div. Leco Instrum. GmbH D-85551 Kirchheim Germany). Browning N. D. Pennycook S. J. Atomic resolution spectroscopy for the microanalysis of materials. Microbeam Anal. 1993 2 81. (Solid State Div. Oak Ridge Natl. Lab. Oak Ridge TN 37831-6030 USA). Nakahara T. Wasa T. Hydride generation inductively coupled plasma atomic emission spectrometry for the determination of germanium in iron meteorites.Microchem. J. 1994 49 202. (Dept. Appl. Chem. Univ. Osaka Prefect. Sakai 593 Japan). Chikuma M. Aoki H. Preconcentration atomic absorption spectrophotometric determination of trace lead( 11) by hydride generation combined with an absorbent water suspension sampling technique. Microchem. J. 1994,49 368. (Osaka Univ. Pharm. Sci. Matsubara 580 Japan). Jaganathan J. Aggarwal I. Separation of iron cobalt nickel and copper from aluminium fluoride and their determination by graphite furnace atomic absorption spectrometry. Microchem. J. 1994 50 44. (Opt. Sci. Div. Nav. Res. Lab. Washington DC 20375-5338 USA). Luge S. Broekaert J. A. C. Use of optical emission spectrometry with microwave induced plasma (MIP)9512331 9512332 9512333 9512334 9512335 95/23 36 9512337 9512338 9512339 9512340 9512341 9512342 9512343 9512344 discharges in a surfatron combined to different types of hydride generation for the determination of arsenic.Mikrochim. Acta 1994 113 277. (Dept. Chem. Univ. Dortmund D-44221 Dortmund Germany). Mohammed B. Ure A. M. Littlejohn D. Study of the complexation chemistry and speciation of thallium for online preconcentration with immobilized quinolin-8- 01. Mikrochim. Acta 1994 113 325. (Dept. Pure Appl. Chem. Univ. Strathclyde Glasgow UK G1 1XL). Schramel P. Haw S. Iodine determination in biologi- cal materials by ICP-MS. Mikrochim. Acta 1994 116 205. (GSF-Res. Cent. Environ. Health Inst. Ecological Chem. Oberschleissheim Germany). Haldimann M. Zimmeli B. Hydride ICP-MS determi- nation of selenium in wheat based on isotope dilution.Mitt. Geb. Lebensmittelunters. Hyg. 1994 85 11 1. (Abt. Lebensmittelwiss. Bundesamt Gesundheitswes. CH-3000 Bern Switzerland). Kobayashi T. Hasegawa SA. Yoshioka T. Hasegawa R. Optimization of measuring condition for the analysis of trace elements in iron and steels by GF-AAS. Nippon Kinzoku Gakkaishi 1994 58 789. (Natl. Res. Inst. Metals Tokyo Japan). Auger G. Mittig W. Lepine-Szily A. Fifield L. K. Bajard M. Baron E. Bibet D. Bricault P. Casandjian J. M. et al. Cyclotron as a high resolution mass spectrometer for fast secondary ions. Nucl. Znstrum. Methods Phys. Res. Sect. A 1994 350 235. (GANIL BP 5027 14021 Caen France). Kulkarni M. J. Argekar A. A. Thulasidas S. K. Dhawale B. A. Rajeswari B.Adya V. C. Purohit P. J. Neelam G. Bangia T. R. et al. Trace metal assay of uranium silicide fuel. Nucl. Technol. 1994 106 326. (Radiochem. Div. Bhabha At. Res. Centre Bombay 400 085 India). Dudnikov S. Y. Kartasheva M. A. Source of inductively coupled plasma (Lych-2000) for emission spectral analysis. Opt. Zh. 1994 5 53. (NIIOP Russia). Ricci M. P. Merritt D. A. Freeman I(. H. Hayes J. M. Acquisition and processing of data for isotope- ratio-monitoring mass spectrometry. Org. Geochem. 1994 21 561. (Depts. Geol. Sci. and Chem. Indiana Univ. Bloomington IN 47405 USA). Merritt D. A. Brand W. A. Hayes J. M. Isotope- ratio-monitoring gas chromatography-mass spec- trometry methods for isotopic calibration. Org. Geochem. 1994 21 573. (Dept. Chem. Indiana Univ. Bloomington IN 47405 USA).Brand W. A. Tegtmeyer A. R. Hilkert A. Compound- s ecific isotope analysis extending toward 1sN/'4N and 1'O/160. Org. Geochem. 1994,21 585. (Finnigan MAT 2800 Bremen Germany). Robe W. E. Griffiths H. Sleep D. Quarmby C. Nitrogen partitioning and assimilation methods for the extraction separation and mass spectrometric analysis of nitrate amino acid and soluble protein pools from individual plants following "N labelling. Plant Cell Environ. 1994 17 1073. (Dept. Agric. & Environ. Sci. Univ. Newcastle-upon-Tyne UK NE1 7RU). Buravlev Y. M. Zamaraev V. P. Cherniavskaya N. V. Basic features in the application of glow discharge for diagnostics of surfaces of iron-based alloys. Pouerkhnost 1994 3 96. (Donetsk. Gos. Univ. Russia). Buravlev Y. M. Ivanitsyn N.P. Miloslavskii A. G. Gorbatenko A. C. Tkachenko G. V. Chernyavskaya N. V. Chamber for atomic emission spectral studies of materials in a controlled atmosphere. Prib. Tekh. Eksp. 1994 1 197. (Russia). Berzins L. V. Using laser absorption spectroscopy to monitor composition and physical properties of metal vapours. Proc. SPIE-lnt. SOC. Opt. Eng. 1994 2068 28. (Lawrence Livermore Natl. Lab. Livemore CA 94550 USA). 9512345 9512346 9512347 9512348 95 f2349 9512350 951235 1 95/23 52 951235 3 9512354 9512355 9512356 95/23 57 951235 8 9512359 Zigler A. Managadze G. Wallace T. Short R. Shanny R. Mobile spectroscopic analysis system. Proc. SPIE-Znt. SOC. Opt. Eng. 1994 2093 322. (ARC0 Power Technol. Inc. Washington DC 20037 USA). Northington D. J. Hovanec B. M.Reich K. Arsenic in groundwater by ICPMS and hydride generation- ICPMS. Proc.-Water Qual. Technol. Conf. 1993 PT.2 1213. (West Coast Anal. Serv. Inc. Santa Fe Springs CA 90670 USA). Gouveia M. A. Prudencio M. I. Barros J. S. Morgado I. Cabral J. M. P. Elemental concentration data for USGS geochemical exploration reference materials GXR-1 to GXR-4 and GXR-6. J. Radioanal. Nucl. Chem. 1994 179 165. (Dept. Quim. ICEN Sacavem 2865 Portugal). Guseva L. I. Tikjomirova G. S. Simultaneous determi- nation of natural and artificial actinides in environment media using ion exchangers and solutions of mineral acids. Radiokhimiya 1994 36 5 1. (Russia). Wei H. Yang P.-y. Wang X.-r. Yang C.4 Su Y.-x. Huang B.4. Microsecond pulsed glow discharge time- of-flight mass spectrometer. Rapid Commun.Mass Spectrom. 1994 8 590. (Dept. Chem. Xiamen Univ. Xiamen 361005 China). Danet A. F. Pisoschi A. Cheregi M. Coupling of flow-injection analysis with atomic absorption spec- trometry. Determination of nickel copper iron and cobalt. Rev. Chim. (Bucharest) 1994 45 135. (Fac. Chim. Univ. Bucuresti Bucharest Romania). Oyama T. Ishii T. Takeuchi K. Particle formation by C02 laser-induced breakdown. (111). Formation of Mo and MoS2 fine powders from Mo(CO),. Reza Kenkyu 1994 22 2. (Inst. Phys. Chem. Res. Wako 351-01 Japan). Bucurescu D. Cata-Danil G. Cata-Dad I. Ivascu M. Petrache C. M. Ur C. A. Stroe L. Recoil mass spectrometer of the Institute of Atomic Physics and the questions that can be addressed by using low-energy secondary beams. Rom. Rep. Phys. 1993,45,8 1.(Heavy Ion Phys. Dept. Inst. At. Phys. Bucharest Romania). Stamm C. Chemical analysis with the inductively coupled plasma. SLZ Schweiz. Lab.-Z. 1994 51 174. (Switzerland). Feng Y. Barratt R. S. Digestion of dust samples in a microwave oven. Sci. Total Enuiron. 1994 143 157. (Fac. Technol. Open Univ. Milton Keynes UK MK7 6AA). Wang Q. Quantitative analysis of platinum and palladium in carbon monoxide combustion improver by spectroscopy. Shiyou Huagong 1994 23 187. (Anal. Test Centre Shandong Jinan 250014 China). Faugeron C. Gill R. Gerdei T. Extension of the measurable range by automation of burner rotation in atomic absorption. Spectra Anal. 1993,22,33. (PHIRA 77600 Bussy St. Georges France). Casabianca H. Seiller I. Bigois M. Use of supercritical fluid extraction (SFE) and gas chromatography with an atomic-emission detector (GC-AED) for determi- nation of substituted phenolic compounds.Spectra Anal. 1993 22 31. (Serv. Cent. Anal. CNRS 69390 Vernaison France). Baudoin J. L. Chevrier M. Herman B. Passetemps R. Hunault P. Surface analysis of conductive and nonconductive materials by glow-discharge spec- trometry. Spectra Anal. 1993 22 47. (Renault S.A. Dir. des Etud. Mater. Serv. 0851 92109 Boulougne France). Smith C. M. M. Hardy J. M. Sensitivities and detection limits for graphite furnace atomic absorption spectrometry using a continuum source and linear photodiode array detection. Spectrochim. Acta Part B 1994 49 387. (Beltsville Human Nutr. Res. Centre Beltsville MD 20705 USA). Journal of Analytical 4tomic Spectrometry August 1995 Vol.10 231 R9512360 9512361 9512362 9512363 9512364 9 512365 9 512 366 9 5/23 67 9512368 9512369 9512370 9512371 9512372 9512373 9512374 9512375 232 R Parvinen P. Lajunen L. H. J. Wieczorek-Ciurowa K. Measurements of the SO2 molecular absorption in the graphite furnace for the possible determination of sulfur. Spectrosc. Lett. 1994 27 727. (Dept. Chem. Univ. Oulu SF-90570 Oulu Finland). Ristoiu D. Ursu D. Lupsa N. Gligan N. Istomin V. G. Isotope analysis of Mars gaseous components. Stud. Univ. Babes-Bolyai Phys. 1991 36 31. (Dept. Phys. Univ. “Babes-Bloyai” 3400 Cluj-Napoca Romania). De Bievre P. Isotope-dilution mass spectrometry (IDMS). Tech. Instrum. Anal. Chem. 1994 15 169. (Inst. Ref. Mater. and Measure. JRC B-2440 Geel Belgium).Baranov S. V. Zemskova 1. A. Maltsev N. E. Use of atomic-absorption analyzer Spektr 5-1 in plants. Tsuetn. Met. (Moscow) 1993 12 65. (A0 “Soyuztsvetmet- avtomatika” Russia). Zayakina S. B. Damen F. I. Yudelevich I. G. Potential of capacitatively-coupled plasma for atomic-emission spectral analysis. Vysokochist. Veshchestua 1994 1 120. (Russia). Zolotovitskaya E. S. Glushkova L. V. Panova E. I. Ramakaeva R. F. Shtitel’man Z. V. Blank A. B. Determination of impurities in the starting substances for production of HTSC materials. Vysokochist. Veshchestua 1994 2 138. (Inst. Monokrist Kharkov Ukraine). Chen J. Determination of trace magnesium in zir- conium and its alloys by flame atomic absorption spectrophotometric method. Xiyou Jinshu Cailiao Yu Gongcheng 1992 21 71.(Northwest Inst. Nonferrous Met. Res. Baoji China). Wu Q.-x. Application of ICP-AES in nonferrous metals. Xiyou Jinshu Cailiao Yu Gongcheng 1992 21 1. (Northwest Inst. Nonferrous Met. Res. Baoji 721014 China). Guo X.-w. Yuan Y. Su Z.-x. Flow injection online preconcentration with rhodanine chelating fibre for the determination of trace gold in geological samples by flame AAS. Yankuang Ceshi 1993 12 241. (Northwest Res. Inst. Geol. CNNC Wan 710054 China). Dong D.-f. Ye D.-m. Zhao J.-h. Zhang H.q. Jin Q.-h. Determination of Fe and A1 by microwave plasma torch atomic emission spectrometry. Yankuang Ceshi 1994 13 41. (Hebei Coll. Geol. Shijiazhuang 050031 China). Zhang HA. Guo J.-y. Determination of selenium and tellurium in copper ores by atomic fluorescence spec- trometry.Yankuang Ceshi 1993 12 287. (Int. Geol. Exp. Anhui Hefei 230001 China). Li B. Determination of impurities in pure lanthanum oxide by inductively-coupled plasma emission spec- trometry. Yankuang Ceshi 1994 13 20. (Inst. Rock Miner. Anal. Minist. Geol. Miner. Resour. Beijing 100037 China). Yin M. Li B. Matrix-induced polyatomic ion inter- ferences in inductively coupled plasma mass spectro- metric analysis of high purity rare earth oxides. Yankuang Ceshi 1994 13 81. (Inst. Rock Miner. Anal. Minist. Geol. Miner. Resour. Beijing 100037 China). Zhang X.4. Determination of other rare earth impurit- ies in 15 individual pure rare earth oxides by controlled atmosphere spectrochemical method. Youkuangye 1993 12 260. (Beijing Res. Inst. Chem. Eng. Metall.CNNC 101 149 China). Xu X.-l. Zhang Y. Determination of trace W and Mo in uranium ore by chemical reaction AES. Youkuangye 1993 12 247. (Beijing Res. Inst. Chem. Eng. Metall. CNNC 101 149 China). Liu HA. Jiang D.-x. Sun G. Zhang R.-j. Yang Z. Detection and identification of the AMS-I4C particles 9512376 95/23 77 9 5/23 7 8 9512379 9512380 9512381 9512382 9512383 9512384 9512385 9512386 9512387 9512388 9512389 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 with ionization chamber telescope. Yuanzineng Kexue Jishu 1994 28 178. (Dept. Tech. Phys. Peking Univ. Beijing 100871 China). Steiner G.-D. MAXIM-novel plasma spectrometer. Zavod. Lab. 1994 60 56. (ARL Fizion Instrum. Switzerland). Semenova N. V. Morosanova E. I. Pletnev I. V. Zolotov Y. A. Sorption cartridges noncovalently modi- fied by 8-hydroxyquinoline for separation concen- tration and atomic-absorption determination of cadmium and lead.Zh. Anal. Khim. 1994 49 477. (Lomonosov Moscow State Univ. Moscow 119899 Russia). Zolotovitskaya E. S. Potapova V. G. Druzenko T. V. Philippovich I. I. Blank A. B. Determination of the stoichiometric composition of complex oxides by flame spectrometric methods. Zh. Anal. Khim. 1994 49 518. (Inst. Single Crystals Kharkov 310001 Ukraine) . Apanasenko V. V. Reznik A. M. Smirnov G. Bukin V. I. Flame atomic emission and absorption determi- nation of alkali metals gallium and aluminium in extracts involving phenol reagents. Zh. Anal. Khim. 1994 49 591. (Lomonosov Inst. Fine Chem. Technol. Moscow 117571 Russia). Morosanova E.I. Pletnev I. V. Solov’ev V. Y. Semenova N. V. Zolotov Y. A. Exchange sorption as a method for increasing selectivity of extraction and determination of copper and iron(1n). Zh. Anal. Khim. 1994 49 676. (Moscow State Univ. Moscow Russia). Simonova L. V. Ozhegov P. I. Karyakin A. V. Use of an inert atomosphere (argon) for atomic emission determination of platinum metals. Zh. Anal. Khim. 1994,49,708. (Vernadskii Inst. Geochem. Anal. Chem. Moscow Russia). Shen L.-s. Luo Y.4. New way to correct background interference in ICP-AES using adaptive filter. Zhongguo Kexue Jishu Dame Xuebao 1992,23,481. (Dept. Radio Electron. China Univ. Sci. Technol. Hefei 230026 China). Shen LA. Yang S. Adaptive correction of ICP-AES spectral overlap interferences. Zhongguo Kexue Jishu Daxue Xuebao 1994 24 79.(Radio Electron. Dept. China Univ. Sci. Technol. Hefei China). Zhang Q.-x. Huang X.-l. Fan S.q. Determination of molybdenum in multi-metal samples by air-acetylene flame atomic absorption spectrophotometry. Zhongnan Kuangye Xueyuan 1994 25 171. (Dept. Miner. Eng. Cent. South Univ. Technol. Changsha 410083 China). Zhukov S. P. Troshin B. I. Chernenko A. A. Analytical features of an atomic-emission spectrometer of laser plasma when detecting carbon admixture in silicon. Zh. Prikl. Spektrosk. 1993 59 216. (Inst. Poluprovodn Novosibirsk Russia). Astashenko S. G. Gridnev N. S. Ignatov B. I. Nepokoychitskiy A. G. Spectral monitoring of metallic- coating thickness. Zh. Prikl. Spektrosk. 1993 59 333. (Inst. Prikl. Opt. Minsk Belarus). Drobyshev A.I. Turkin Y. I. Yakimova N. M. Application of an atomic-emission spectroscopy method for estimating stoichiometric relations of elements in high-temperature superconducting materials based on Bi-Sr-Ca-Cu-0. Zh. Prikl. Spektrosk. 1994 60 7. (NIIKhim. St. Petersburg Univ. St. Petersburg 198904 Russia). Xu Z.-g. Xiong Y.-f. Xu D.-r. Study on slotted tube atom trapping technique. Zhejiang Daxue Xeubao Ziran Kexueban 1993 27 542. (Cent. Anal. Test. Zhejiang Univ. Hangzhou China). Peter S. Pintaske R. Reinhold B. Richter F. Hecht G. Determination of ion energy distribution in glow discharges. Thin Films Proc. Jt. 4th Znt. Symp. Trends9512390 951239 1 9512392 9512393 9 5/23 94 9512395 9512396 9512397 9512398 9512399 New Appl. Thin Films 11th Conf. High Vac. Interfaces Thin Films.Edited by Hecht G.; Richter F; Hahn J.. DGM Informationsges. Oberursel Germany 1993. Burguera M. Burguera J. L. Rondon C. Rivas C. Carrero P. Gallignani M. Brunetto M. R. In uiuo sample uptake and on-line measurements of cobalt in whole blood by microwave-assisted mineralization and flow injection electrothermal atomic absorption spec- trometry. J. Anal. At. Spectrom. 1995 10 343. (IVAIQUIM (Andean Inst. Chem. Res.) Fac. Sci. Univ. Los Andes P.O. Box 542 Merida 5101-A Venezuela). Smith M. M. White M. A. Wilson H. K. Determination of antimony in urine by solvent extrac- tion and electrothermal atomization atomic absorption spectrometry for the biological monitoring of occu- pational exposure. J. Anal. At. Spectrom. 1995 10 349. (Biomed. Sci. Group Health and Safety Lab.Health and Safety Executive Broad Lane Sheffield UK S3 7HQ). Chakraborty R. Das A. K. Cervera M. L. De La Guardia M. Determination of chromium by electrother- mal atomic absorption spectrometry after rapid micro- wave-assisted digestion of sediment and botanical samples. J. Anal. At. Spectrom. 1995 10 353. (Dpto. Quim. Anal. Univ. Valencia Dr. Moliner 50 46100 Burjassot Valencia Spain). Zhang Y.-F. Zhang K. Fang Z. Wang Y.-Z. Determination of trace amounts of aluminium in high-purity tin by electrothermal atomic absorption spectrometry. J. Anal. At. Spectrom. 1995 10 359. (Imp./Exp. Comm. Inspec. Bureau of Yunnan Kunming 650034 China). Inoue Y. Kawabata K. Suzuki Y. Speciation of organotin compounds using inductively coupled plasma mass spectrometry with micellar liquid chromatogra- phy.J. Anal. At. Spectrom. 1995 10 363. (Div. R & D Yokogawa Anal. Systems Inc. 11-19 Nakacho 2-chome Musashino-shi Tokyo 180 Japan). Paschal D. C. Caldwell K. L. Ting B. G. Determination of lead in whole blood using inductively coupled argon plasma mass spectrometry with isotope dilution. J. Anal. At. Spectrom. 1995 10 367. (Div. Environ. Health Lab. Sci. Natl. Center Environ. Health Centers for Disease Control and Prevention Public Health Service US Dept. Health and Human Services Atlanta GA 30333 USA). Seubert A. Petzold G. McLaren J. W. Synthesis and application of an inert type of 8-hydroxyquinoline- based chelating ion exchanger for sea-water analysis using on-line inductively coupled plasma mass spec- trometry detection.J Anal. At. Spectrom. 1995 10 371. (Inst. Anorg. Chem. Univ. Hannover Callinstr. 9 D-30167 Hannover Germany). Garcia Alonso J. I. Sena F. Arbore P. Betti M. Koch L. Determination of fission products and actinides in spent nuclear fuels by isotope dilution ion chromatog- raphy inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 1995,10 381. (Eur. Comm. JRC Inst. Transuranium Elements Postfach 2340 76125 Karlsruhe Germany). Tayloe P. D. P. De Bievre P. Walder A. J. Entwistle A. Validation of the analytical linearity and mass discrimination correction model exhibited by a multiple collector inductively coupled plasma mass spectrometer by means of a set of synthetic uranium isotope mixtures. J. Anal. At. Spectrom. 1995 10 395. (Inst.Ref. Mater. and Measurements Comm. European Comm. JRC Retieseweg B-2440 Geel Belgium). McCrindle R. I. Rademeyer C. J. Excitation tempera- ture and analytical parameters for an ethanol loaded inductively coupled plasma atomic emission spec- trometer. J. Anal. At. Spectrom. 1995 10 399. (Dept. Chem. and Phys. Technikon Pretoria Private Bag X680 Pretoria 0001 South Africa). 187-90. 95/2400 9 51240 1 9512402 9512403 9512404 9512405 9512406 9512407 95/2408 9512409 9512410 951241 1 95/2412 951241 3 Journal of Analytical Uggerud H. Lund W. Use of thiourea in the determination of arsenic antimony bismuth selenium and tellurium by hydride generation inductively coupled plasma atomic emission spectrometry. J. Anal. At. Spectrom. 1995 10 405. (Dept. Chem. Univ. Oslo P.O. Box 1033 N-0315 Oslo Norway).Hill S. J. Pitts L. Worsfold P. Investigation into the kinetics of selenium(v1) reduction using hydride gener- ation atomic fluorescence detection. J. Anal. At. Spectrom. 1995 10 409. (Dept. Environ. Sci. Univ. Plymouth Drake Circus Plymouth UK PL4 8AA). Tetens V. Kristensen N. B. Calder A. G. Measurement of 13C enrichment of plasma lactate by gas chromatogra- phylisotope ratio mass spectrometry. Anal. Chem. 1995 67 858. (Dept. Animal Physiol. and Biochem. Natl. Inst. Animal Sci. Tjele DK-8830 Denmark). Tanaka T. Kubota T. Kawaguchi H. Effects of the discharge-gas flow rate on the relative sensitivity factors in glow-discharge mass spectrometry with a Grimm- type ion source. Anal. Sci. 1994 10 895. (Dept. Mater. Sci. Eng. Nagoya Univ Nagoya 464-01 Japan).Li X. S. Liu Y. F. Shi J. Y. Wang X. Y. Liu K. X. Guo Z. Y. Li K. Chen C. E. Yuan S. X. Genotoxicity of nicotine studied by accelerator mass spectrometry. Chin. Chem. Lett. 1994 5 1043. (Dept. Tech. Phys. Peking Univ. Beijing 100871 China). Giessmann U. Greb U. High resolution ICP-MS-a new concept for elemental mass spectrometry. Fresenius’ J. Anal. Chem. 1994 350 186. (Finnigan MAT GmbH D-28197 Bremen Germany). Dulski P. Interferences of oxide hydroxide and chloride analyte species in the determination of rare earth elements in geological samples by inductively coupled plasma mass spectrometry. Fresenius ’ J. Anal. Chem. 1994 350 194. (GeoForschungsZentrum (GFZ) Potsdam D-14473 Pottsdam Germany). Rottmann L. Heumann K. G. Development of an online isotope dilution technique with HPLCIICP-MS for the accurate determination of elemental species.Fresenius’ J . Anal. Chem. 1994 350 221. (Inst. Anorg. Chem. Univ. Regensburg D-93040 Regensburg Germany). Luedke C. Hoffmann E. Skole J. Comparative studies on metal determination in airborne particulates by LA-ICP-MS and furnace atomization non-thermal excitation spectrometry. Fresenius’ J. Anal. Chem. 1994 350,272. (Lab. Spektrosk. Methoden Umweltanal. Inst. Spektrochem. angewandte Spektrosk. D-12489 Berlin Germany). Richner P. Evans D. Wahrenberger C. Volker D. Applications of laser ablation and electrothermal vapor- ization as sample introduction techniques for ICP-MS. Fresenius’ J. Anal. Chem. 1994 350 235. (Swiss Fed. Labs. Mater. Testing Res. CH-8600 Duebendorf Switzerland).De Bievre P. Stable isotope dilution an essential tool in metrology. Fresenius’ J. Anal. Chem. 1994 350 277. (Inst. Ref. Mater. and Measure. Comm. Eur. Commun. B-2440 Geel Belgium). Chang T. L. Qian Q.-Y. Zhao M.-T. Wang J. Absolute isotopic composition of europium. Int. J. Mass Spectrom. Ion Processes 1994 139 95. (Dept. Chem. Peking Univ. Beijing 100871 China). Aggarwal S. K. Saxena M. K. Shah P. M. Kumar S. Jairaman U. Jain H. C. Studies on the evaporation and ionization behaviour of uranium and plutonium in thermal ionization mass spectrometry. Int. J. Mass Spectrom. Ion Processes 1994 139 111. (Fuel Chem. Div. Bhabha At. Res. Centre Trombay Bombay 400 India). Goodman K. J. Brenna J. T. High-precision gas chromatography-combustion isotope ratio mass spec- 4tomic Spectrometry August 1995 Vol.10 233 R951241 4 9512415 951241 6 9512417 9512418 9512419 9512420 951242 1 9 512422 9 512423 9512424 9512425 9512426 234 R trometry at low signal levels. J. Chromatogr. A 1995 689 63. (Div. Nutr. Sci. Cornell Univ. Ithaca NY 14853 USA). Shinohara A. Chiba M. Inaba Y. Analysis of trace elements in biological materials by microwave-induced plasma mass spectrometry. Nippon Eiseigaku Zasshi 1994 49 924. (Sch. Med. Juntendo Univ. Tokyo 113 Japan). Jakubowski N. Stuewer D. Recent progress in plasma mass spectrometry. Spec. PubL-R. SOC. Chem. 1994 154 121. (Inst. Spektrochem. Angew. Spektrosk. D-44013 Dortmund Germany). Stetzenbach K. J. Amano M. Kreamer D. K. Hodge V. F. Testing the limits of ICP-MS determination of trace elements in groundwater at the part-per-trillion level. Ground Water 1994 32 976.(Harry Reid Centre Environ. Stud. Univ. Nevada-Las Vegas Las Vegas Nakamura T. Shikano K. Sakamoto T. 14C dates by accelerator mass spectrometry relating to the latest change of channels of Kiso River at around Minokamo and Seki Gifu Prefecture central Japan. Chikyu Kugaku (Chigaku Dantai Kenkyukai ) 1994 48 497. (Dating Mater. Res. Centre Nagoya Univ. Nagoya 464-01 Japan). Gobeil C. Johnson W. K. MacDonald R. W. Wong C. S. Sources and burden of lead in St. Lawrence Estuary sediments isotopic evidence. Environ. Sci. Technol. 1995 29 193. (Minist. des Ptches et des OcC Inst. Maurice-Lamontagne C.P. 1000 Mont-Joli Quebec Canada G5H 324). Spooner N. Rieley G. Collister J.W. Lander M. Cranwell P. A Maxwell J. R. Stable carbon isotopic correlation of individual biolipids in aquatic organisms and a lake bottom sediment. Org. Geochem. 1994 21 823. (Org. Geochem. Unit Sch. Chem. Univ. Bristol Bristol UK BS8 1TS). O'Malley V. P. Abrajano Jr. T. A. Hellou J. Determination of the 13C/'2C ratios of individual PAH from environmental samples can PAH sources be apportioned? Org. Geochem. 1994,21,809. (Dept. Earth Sci. Memorial Univ. Newfoundland St. John's Newfoundland Canada A1B 3x5). Ishiwatari R. Uzaki M. Yamada K. Carbon isotope composition of individual n-alkanes in recent sediments. Org. Geochem. 1994 21 801. (Dept. Chem. Fac. Sci. Tokyo Metropolitan Univ. Hachioji Tokyo 192-03 Japan). Mycke B. Hall K. Leplat P. Carbon isotopic composition of individual hydrocarbons and associated gases evolved from micro-scale sealed vessel (MSSV) pyrolysis of high molecular weight organic material.Org. Geochem. 1994 21 787. (Fina Explor. and Prod. Fina Res. S.A. Zone Industrielle C 7181 Seneffe (Feluy) Belgium). Bjorcry M. Hall P. B. Moe R. P. Variation in the isotopic composition of single components in the C,-C2 fraction of oils and condensates. Org. Geochem. 1994,21,761. (Geolab Nor P.O. Box 5740 Fossegrenda 7002 Trondheim Norway). Wilhelms A. Larter S. R. Hall K. Comparative study of the stable carbon isotopic composition of crude oil alkanes and associated crude oil asphaltene pyrolysate alkanes. Org. Geochem. 1994 21 751. (Dept. Geol. Univ. Oslo P.O. Box 1047 0316 Oslo-3 Norway). Clayton C. J. Bjorcry M.Effect of maturity on 13C/12C ratios of individual compounds in North Sea oils. Org. Geochern. 1994 21 737. (BP Res. Centre Chertsey Rd. Sunbury-on-Thames UK TW16 7LN). Eglinton T. I. Carbon isotcpic evidence for the origin of macromolecular aliphatic structures in kerogen. Org. Geochem. 1994 21 721. (Dept. Mar. Chem. and NV 89154-4009 USA). 9512427 9512428 9512429 9512430 951243 1 9 512432 9512433 9512434 9512435 9 51243 6 9 51243 7 9 51243 8 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 Geochem. Woods Hole Oceanogr. Inst. Woods Hole MA 02543 USA). Schoell M. Simoneit B. R. T. Wang T.-G. Organic geochemistry and coal petrology of Tertiary brown coal in the Zhoujing mine Bake Basin South China - 4. Biomarker sources inferred from stable carbon isotope compositions of individual compounds.Org. Geochem. 1994 21 713. (Chevron Petrol. Technol. Co. 1300 Beach Blvd. La Habra CA 90631 USA). Boreham C. J. Summons R. E. Roksandic Z. Dowling L. M. Hutton A. C. Chemical molecular and isotopic differentiation of organic facies in the Tertiary lacustrine Duaringa oil shale deposit Queensland Australia. Org. Geochem. 1994 21 685. (Onshore Sedimentary and Petroleum Geol. Branch Australian Geol. Surv. Org. G.P.O. Box 378 Canberra ACT 2601 Australia). Schoell M. Hwang R. J. Carlson R. M. K. Welton J. E. Carbon isotopic composition of individual biomar- kers in gilsonites (Utah). Org. Geochem. 1994 21 673. (Chevron Petroleum Technol. Co. 1300 Beach Blvd. La Habra CA 90633 USA). Ruble T. E. Bakel A. J. Philp R. P. Compound specific isotopic variability in Uinta Basin native bitumens paleoenvironmental implications. Org.Geochem. 1994 21 661. (Sch. Geol. and Geophys. Univ. Oklahoma Norman OK 73019 USA). Collister J. W. Lichtfouse E. Hieshima G. Hayes J. M. Partial resolution of sources of n-alkanes in the saline portion of the Parachute Creek Member Green River Formation (Piceance Creek Basin Colorado). Org. Geochem. 1994,21,645. (Biogeochem. Lab. Depts. Geol. Sci. and Chem. Indiana Univ. Geol. Building Bloomington IN 47405 USA). Freeman K. H. Wakeham S. G. Hayes J. M. Predictive isotopic biogeochemistry hydrocarbons from anoxic marine basins. Org. Geochem. 1994 21 629. (Dept. Geosci. Pennsylvania State Univ. State College PA 16802 USA). Collister J. W. Rieley G. Stern B. Eglinton G.Fry B. Compound-specific 613C analyses of leaf lipids from plants with differing carbon dioxide metabolisms. Org. Geochem. 1994,21,619. (Org. Chem. Unit Sch. Chem. and Biochem. Centre Univ. Bristol Bristol UK BS8 1TS). Abrajano T. A. Jr. Mur hy D. E. Fang J. Comet acids of marine mytilids with and without bacterial symbionts. Org. Geochem. 1994 21 611. (Dept. Earth Sci. Memorial Univ. Newfoundland St. John's Newfoundland Canada A1B 3x5). Silfer J. A Qian Y. Macko S. A. Engel M. H. Stable carbon isotope compositions of individual amino acid enantiomers in mollusc shell by GC-C-IRMS. Org. Geochem. 1994,21,603. (Sch. Geol. and Geophys. Energy Center Univ. Oklahoma 100 E. Boyd St. Norman OK 73019 USA). Bakel A. J. Ostrom P. H. Ostrom N. E. Carbon isotopic analysis of individual n-alkanes evaluation of accuracy and application to marine particulate organic material.Org. Geochem. 1994 21 595. (Dept. Geosci. Argonne Natl. Lab. Argonne IL 60439 USA). Inoue H. Y. Mook W. G. Equilibrium and kinetic nitrogen and oxygen isotope fractionations between dissolved and gaseous N,O. Chem. Geol. (Isot. Geosci. Sect.) 1994 113 135. (Center for Isotope Res. Univ. Groningen Nijenborgh 4 NL-9747 Groningen Netherlands). Bird M. I. Quade J. Chivas A. R. Fifield L. K. Allan G. L. Head M. J. Carbon isotope composition of organic matter occluded in iron nodules. Chem. Geol. (Isot. Geosci. Sect.) 1994 114 269. (Res. Sch. Earth Sci. Australian Natl. Univ. Canberra A.C.T. 0200 Australia). P. Brooks J. M. 13C/ l! C ratios in individual fatty9512439 95/2440 9512441 9512442 9512443 9 512444 9512445 9512446 9512447 9512448 9512449 9512450 Eisenhauser A.Spielhagen R. F. Frank M. Hentzscbel G. Mangini A. Kubik P. W. Dittrich- Hannen B. Bilien T. "Be records of sediment cores from high northern latitudes implications for environ- mental and climatic changes. Earth Planet. Sci. Lett. 1994 124 171. (Heidelberger Akad. Wissenschaften Im Neuenheimer Feld 366 69 120 Heidelberg Germany). Horn M. Heumann K. G. Comparison of heavy metal analyses in hydrofluoric acid used in microelectronic industry by ICP-MS and thermal ionization isotope dilution mass spectrometry. Fresenius' J. Anal. Chem. 1994 350 286. (Siemens AG Regensburg Wernerwerkstr. 2 D-93049 Regensburg Germany). Pritzkow W. Riebe G. Tamberg T. Determination of minor element concentrations in reference materials.First results obtained with total evaporation and integrating IDA-TIMS measurements. Fresenius ' J. Anal. Chem. 1994 350 298. (Bundesanstalt fur Mater. und -prufung (BAM) Unter den Wichen 87 D-12200 Berlin Germany). Jochum K. P. Jenner G. Trace element analysis of Geological Survey of Japan silicate reference materials comparison of SSMS with ICP-MS data and a critical discussion of compiled values. Fresenius' J. Anal. Chem. 1994 350 3 10. (Max-Planck-Inst. Chem. Postfach 3060 D-55020 Mainz Germany). Kouzes R. T. Fourier transform ion cyclotron resonance versus time of flight for precision mass measurements. Hyperfine Interact. 1993 81 123. (Pacific Northwest Lab. MS K1-87 P.O. Box 999 Richland WA 99352 USA).Wouters J. M. Tu X. L. Zhou X. G. Vieira D. J. Seifert H. L. Lobner K. E. G. Zhou Z. Y. Lind V. G. Butler G. W. Weight of the matter mass measure- ments of exotic neutron-rich nuclei. Inst. Phys. Con5 Ser. 1993 132 25. (Isotope and Nucl. Chem. Div. Los Alamos Natl. Lab. Los Alamos NM 87545 USA). Sharma K. S. Unger P. Dyck G. R. Barber R. C. Hagberg E. Hykawy J. G. Koslowsky V. T. Hardy J. C. Schmeing H. Savard G. Perry W. Watson M. Direct mass deteminations of neutron deficient nuclei close to '%n. Inst. Phys. Conf. Ser. 1993 132 31. (Dept. Phys. Univ. Manitoba Winnipeg Manitoba Canada R3T 2N2). Kouzes R. T. Fourier transform ion cyclotron resonance precision atomic mass measurement limits. Inst. Phys. Conf. Ser. 1993 132 65. (Pacific Northwest Lab.MS K1-87 P.O. Box 999 Richland WA 99352 USA). Hykawy J. G. Barber R. C. Sharma K. S. Nxumalo J. N. Dyck G. R. Sidky M. S. Unger P. P. Peters R. Lander C. A. Duckworth H. E. Recent neutrino- physics related mass measurements at the University of Manitoba. Inst. Phys. Conf. Ser. 1993 132 73. (Phys. Dept. Univ. Manitoba Winnipeg Manitoba Canada R3T 2N2). Dale L. S. Stauber J. L. Farrell 0. P. Florence T. M. Gulson B. L. Comparative study of ICP-MS and TIMS for measuring skin absorption of lead. Applications of plasma source mass spectrometry IZ. Royal Society of Chemistry Thomas Graham House Science Park Cambridge UK CB4 4WF 1993. 124. Hotchkis M. A. C. Fink D. Jacobsen G. E. Lawson E. M. Shying M. Smith A. M. Tuniz C. Barbetti M. Grave P. Quan H. M. Head J. 14C analyses at the ANTARES AMS Centre dating the log coffins of northwest Thailand. Nucl.Znstrum. Methods Phys. Res. Sect. By 1994 92 27. (Australian Nucl. Sci. and Technol. Org. Private Mail Bag 1 Menai N.S.W. 2234 Australia). Sie S. H. Leaney F. Gillespie R. Suter G. F. Ryan C. G. Radiocarbon measurements at the CSIRO AMS facility. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 35. (Heavy Ion Anal. Fac. CSIRO Div. 951245 1 9512452 9512453 9512454 9 51245 5 9512456 9512457 9512458 9512459 9512460 951246 1 9512462 9512463 Journal of Analytical Explor. and Mining P.O. Box 136 North Ryde N.S.W. 21 13 Australia). Bronk Ramsey C. Hedges R. E. M. Carbon dioxide sputter source development at Oxford. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 100. (Oxford Radiocarbon Accelerator Unit Res.Lab. Archaeol. and History of Art Univ. Oxford 6 Keble Rd. Oxford UK OX1 345). Currie L. A. Optimal estimation of uncertainty intervals for accelerator and decay counting. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 188. (Natl. Inst. Stand. Technol. Gaithersburg MD 20899 USA). Niklaus T. R. Bonani G. Suter M. Wolfli W. Systematic investigation of uncertainties in radiocarbon dating due to fluctuations in the calibration curve. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 194. (Inst. Particle Phys. ETH-Honggerberg CH-8093 Zurich Switzerland). Zhao X.-L. Nadeau M.-J. Garwan M. A. Kilius L. R. Litherland A. E. Radium actinides and their molecular negative ions from a caesium sputter ion source. Nucl. Instrum. Methods Phys. Res. Sect.B 1994 92 258. (IsoTrace Lab. Dept. Phys. Univ. Toronto 60 St. George St. Toronto Ontario Canada M5S 1A7). Nadeau M. J. Litherland A. E. Garwan M. A Zhao X.-L. Electric dissociation of negative ions-11. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 265. (IsoTrace Lab. Univ. Toronto Toronto Ontario Canada M5S 1A7). Spindler K. Iceman's last weeks. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 274. (Forschungsinst. Alpine Vorzeit Univ. Innsbruck A-6020 Innsbruck Austria). Prinoth-Fornwagner R. Niklaus T. R. Man in the ice results from radiocarbon dating. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 282. (Forschungsinst. Alpine Vorzeit Univ. Innsbruck A-6020 Innsbruck Austria). Lal D. Jull A. J. T. Studies of cosmogenic in situ 14C0 and 14C02 produced in terrestrial and extraterres- trial samples experimental procedures and applications.Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 291. (Geol. Res. Div. Scripps Inst. Oceanogr. La Jolla Reedy R. C. Nishiizumi K. Lal D. Arnold J. R. Englert P. A. J. Klein J. Middleton R. Jull A. J. T. Donahue D. J. Simulations of terrestrial in-situ cosmog- enic-nuclide production. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 297. (Space Sci. and Technol. Div. MS-D436 Los Alamos Natl. Lab. Los Alamos NM 87545 USA). Dep L. Elmore D. Lipschutz M. Vogt S. Phillips F. M. Zreda M. Depth dependence of cosmogenic neutron-capture-produced 36Cl in a terrestrial rock. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 301. (Dept. Phys. Purdue Univ. West Lafayette IN 47907 USA).Jull A. J. T. Lifton N. Phillips W. M. Quade J. Studies of the production rate of cosmic-ray produced 14C in rock surfaces. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 308. (Dept. Geosci. NSF Arizona AMS Fac. Univ. Arizona Tucson AZ 85721 USA). Stone J. Allan G. L. Fified L. K. Evans J. M. Chivas A. R. Limestone erosion measurements with cosmogenic chlorine-36 in calcite - preliminary results from Australia. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 311. (Res. Sch. Earth Sci. Australian Natl. Univ. Canberra A.C.T. 0200 Australia). Strack E. Heisinger B. Dockhorn B. Hartmann F. J. Korschinek G. Nolte E. Morteani G. Petitjean C. Neumaier S. Determination of erosion rates with cosmogenic 26A1. Nucl. Znstrum. Methods Phys. Res. CA 92093-0220 USA). Atomic Spectrometry August 1995 Vol.10 235 R9512464 9512465 9512466 9512467 9512468 9512469 9512470 951247 1 9512472 9 51247 3 9512474 9512475 236 R Sect. B 1994,92 317. (Fac. Phys. Tech. Univ. Munich D-85747 Garching Germany). Dep L. Elmore D. Fabryka-Martin J. Masarik J. Reedy R. C. Production rate systematics of in-situ- produced cosmogenic nuclides in terrestrial rocks Monte Carlo approach of investigating 35Cl(n,y)36Cl. Nucl. Instrum. Methods Phys. Res. Sect. By 1994 92 321. (Dept. Phys. Purdue Univ. West Lafayette IN 47907 USA). Jull A. J. T. Lal D. Donahue D. J. Mayewski P. Lorius C. Raynaud D. Petit J. R. Measurements of cosmic-ray-produced 14C in firn and ice from antarctica. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 326. (NSF Arizona Accelerator Mass Spectrom.Fac. Univ. Arizona Tucson AZ 85721 USA). van Roijen J. J. Bintanja R. van der Borg K. van den Broeke M. R. de Jong A. F. M. Oerlemans J. Dry extraction of 14C02 and 14C0 from Antarctic ice. Nucl. Znstrum. Methods Phys. Res. Sect. By 1994 92 331. (Dept. Subatomic Phys. Univ. Utrecht P.O. Box 80.000 3508 TA Utrecht Netherlands). Reedy R. C. Tuniz C. Fink D. Report on the workshop on production rates of terrestrial in-situ- produced cosmogenic nuclides. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 335. (Astrophys. and Radiation Measurements Group Los Alamos Natl. Lab. Mail Stop D436 Los Alamos NM 87545 USA). Knies D. L. Elmore D. Sharma P. Vogt S. Li R. Lipschutz M. E. Petty G. Farrell J. Monaghan M. C. Fritz S. Agee E. 'Be "Be and 36Cl in precipitation.Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 340. (Dept. Phys. Purdue Univ. West Lafayette IN 47907 USA). Hainsworth L. J. Mignerey A. C. Helz G. R. Sharma P. Kubik P. W. Modern chlorine-36 deposition in southern Maryland USA. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994,92,345. (Dept. Chem. and Biochem. Univ. Maryland College Park MD 20742 USA). Boaretto E. Berkovits D. Delmas R. Johnson R. R. Kaufman A. Magaritz M. Paul M. Pourchet M. Measurements of anthropogenic radionuclides in environmental samples. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 350. (Racah Inst. Phys. Hebrew Univ. Jerusalem 91904 Israel). Monaghan M. C. Elmore D. Garden variety "Be in soils on hill slopes. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 357. (Dept.Earth and Atmos. Sci. Dept. Phys. Purdue Univ. West Lafayette IN 47907 USA). Middleton R. Klein J. Dezfouly-Arjomandy B. Albrecht A. Xue S. Herzog G. F. Gregory J. "Be in bauxite and commercial aluminium. Nucl. Znstrum. Methods Phys. Res. Sect. By 1994,92,362. (Dept. Phys. Univ. Pennsylvania Philadelphia PA 19104 USA). Milton G. M. Andrews H. R. Causey S. E. Chant L. A. Cornett R. J. Davies W. G. Greiner B. F. Koslowsky V. T. Imahori Y. Kramer S. J. McKay J. W. Milton J. C. D. Chlorine-36 dispersion in the Chalk River area. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 376. (AECL Res. Chalk River Lab. Chalk River Ontario Canada KOJ 1JO). Fehn U. Moran J. E. Tang R. T. D. Rao U. Dating and tracing of fluids using 1291 and 36Cl results from geothermal fluids oil field brines and formation waters.Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 380. (Dept. Geol. Sci. and Nucl. Structure Res. Lab. Univ. Rochester Rochester NY 14627 USA). Gascoyne M. Sharma P. Kubik P. W. Origin of groundwater salinity in the Lac du Bonnet granite southeastern Manitoba from 36Cl measurements. Nucl. Znstrum. Methods Phys. Rcs. Sect. By 1994 92 389. (Appl. Geosci. Branch AECL Res. Pinawa Manitoba Canada ROE 1LO). 9512476 9512477 9512478 9512479 9512480 951248 1 9 51248 2 9 51248 3 9512484 9 51248 5 9512486 9512487 9512488 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 Kilius L. R. Rucklidge J. C. Soto C. Dispersal of I2'I from the Columbia River estuary. Nucl. Instrum. Methods Phys. Res. Sect. By 1994 92 393. (IsoTrace Lab.Univ. Toronto Toronto Canada). Vogt S. Elmore D. Fritz S. J. 36Cl in shallow perched aquifers from central Indiana. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 398. (Dept. Chem. Purdue Univ. West Lafayette IN 47907 USA). Currie L. A. Klouda G. A. Klinedinst D. B. Sheffield A. E. Jull A. J. T. Donahue D. J. Connolly M. V. Fossil- and bio-mass combustion C- 14 for source identification chemical tracer development and model validation. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994,92,404. (Natl. Inst. Stand. Technol. Gaithersburg MD 20899 USA). Eisma R. van der Borg K. de Jong A. F. M. Kieskamp W. M. Veltkamp A. C. Measurements of the 14C content of atmospheric methane in The Netherlands to determine the regional emissions of 14CH4. Nucl. Znstrum. Methods Phys.Res. Sect. B 1994 92 410. (Netherlands Energy Res. Foundation ECN P.O. Box 1 1755 ZG Petten Netherlands). Rucklidge J. Kilius L. Fuge R. 1291 in moss down- wind from the Sellafield nuclear fuel reprocessing plant. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 417. (IsoTrace Lab. Univ. Toronto Toronto Canada M5S 1A7). Kalish J. M. Investigating global change and fish biology with fish otolith radiocarbon. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 421. (Div. Bot. and Zool. Australian Natl. Univ. Canberra A.C.T. 0200 Australia). Jones G. A. Gagnon A. R. von Reden K. F. McNichol A. P. Schneider R. J. High-precision AMS radiocarbon measurements of central Arctic Ocean sea waters. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 426. (Natl. Ocean Sci. Accelerator Mass Spectrom.Facility Woods Hole Oceanogr. Inst. Woods Hole MA 02543 USA). Gislefoss J. S. Nydal R. Donahue D. J. Jull A. J. T. Toolin L. T. Tracer studies of 14C in the Nordic Seas by AMS measurements. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994,92,431. (Radiol. Dating Lab. Norwegian Inst. Technol. N-7034 Trondheim NTH Norway) . Yiou F. Raisbeck G. M. Zhou Z. Q. Kilius L. R. 12'1 from nuclear fuel reprocessing; potential as an oceanographic tracer. Nucl. Znstrum. Methods Phys. Res. Sect. By 1994 92 436. (Centre Spectrom. Nucl. et Spectrom. Masse IN2P3-CNRS Bltiment 108 9 1405 Campus Orsay France). Milton J. C. D. Andrews H. R. Chant L. A. Cornett R. J. J. Davies W. G. Greiner B. F. Imahori Y. Koslowsky V. T. McKay J. W. Milton G. M. 36Cl in the Laurentian Great Lakes basin.Nucl. Znstrum. Methods Phys. Res. Sect. By 1994,92,440. (AECL Res. Chalk River Lab. Chalk River Ontario Canada KOJ 1PO). Fink D. Walton J. Hotchkis M. A. C. Jacobsen G. E. Lawson E. M. Smith A. M. Tuniz C. Wilcox D. First 26A1 analyses at the ANTARES AMS Centre uptake via oral ingestion of 26A1 in rats. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 473. (ANSTO PMB 1 Menai 2234 N.S.W. Australia). Hohl C. Gerisch P. Korschinek G. Nolte E. Ittel T. H. Medical application of 26A1. Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 478. (Fac. Phys. Tech. Univ. Munich D-85747 Garching Germany). Johnson R. R. Berkovits D. Boaretto E. Gelbart Z. Ghelberg S. Meirav O. Paul M. Prior J. Sossi V. Venczel E. Calcium resorption from bone in a human studied by 41Ca tracing.Nucl. Znstrum. Methods Phys. Res. Sect. B 1994 92 483. (Racah Inst. Phys. Hebrew Univ. Jerusalem 91904 Israel).9512489 9 512490 951249 1 9512492 9512493 9512494 9512495 9512496 9512497 9512498 9512499 9512500 95 f2501 Southon J. R. Bishop M. S. Kost G. J. 41Ca as a tracer for calcium uptake and deposition in heart tissue during ischemia and reperfusion. Nucl. Instrum. Methods Phys. Res. Sect. B 1994 92 489. (Center for AMS L-397 Lawrence Livermore Natl. Lab. Livermore CA Welten K. C. Lindner L. van der Borg K. Alderliesten C. van Roijen J. J. de Jong A. F. M. Schultz L. AMS measurements of “Be and 26A1 for studying shielding effects in meteorites. Nucl. Instrum. Methods Phys. Res. Sect. By 1994 92 500. (Dept. Subatomic Phys. Univ.Utrecht P.O. Box 80.000,3508 TA Utrecht Netherlands). Cresswell R. G. Beukens R. P. Rucklidge J. C. Miura Y. Distinguishing spallogenic from non- spallogenic carbon in chondrites using gas and tempera- ture separations. Nucl. Instrum. Methods Phys. Res. Sect. By 1994 92 505. (Dept. Geol. Univ. Toronto Toronto Ontario Canada M5S 3Bl). Sisterson J. M. Jull A. J. T. Beverding A. Koehler A. M. Castaneda C. Vincent J. Donahue D. J. Englert P. A. J. Gans C. Young J. Reedy R. C. Proton production cross sections for I4C from silicon and oxygen implications for cosmic-ray studies. Nucl. Instrum. Methods Phys. Res. Sect. By 1994 92 510. (Harvard Cyclotron Lab. Harvard Univ. Cambridge MA 02138 USA). Araujo M. F. Alves L. C. Cabral J. M. P. Comparison of energy-dispersive XRF and PIXE in the analysis of ancient gold coins.Nucl. Instrum. Methods Phys. Res. Sect. B 1993 75 450. (Dept. Quim. Inst. Ciencias e Eng. Nucl. LNETI 2685 Sacavem Portugal). Vis R. D. Comparison between the use ofMeV ion beams and synchrotron radiation for element analysis. Nucl. Instrum. Methods Phys. Res. Sect. B 1993 75 547. (Fac. Phys. and Astron. Vrije Univ. Amsterdam Netherlands). Sutton S. R. Rivers M. L. Bajt S. Jones K. W. Synchrotron X-ray fluorescence micro-probe analysis with bending magnets and insertion devices. Nucl. Instrum. Methods Phys. Res. Sect. By 1993 75 553. (Dept. Geophys. Sci. and Consortium for Adv. Radiat. Sources Univ. Chicago Chicago IL 60637 USA). Yang G.-y. Xu D.-x. Flame atomic absorption spectro- photometric determination of copper zinc and iron in human erythrocyte membranes.Guangpuxue Yu Guangpu Fenxi 1994 14(2) 91. (Dept. Instrum. Anal. Zhenjiang Med. Coll. 2 12001 Zhenjiang China). Cai Q.-x. Dai J. Zhou Y.-c. Determination of calcium in rat’s cardiac muscle by AAS. Guangpuxue Yu Guangpu Fenxi 1994 14(2) 101. (Shanghai Inst. Org. Chem. Acad. Sin. 200032 Shanghai China). Dong Y.-g. Su Z.-w. Shen H.-j. Shen Z.-w. Sheng Y.-m. Determination of trace germanium by flame atomic absorption spectrophotometry. Guangpuxue Yu Guangpu Fenxi 1994,14( 2) 109. (Changzhou Sanitation and Anti-epidemic Station Changzhou China). Chen H.-w. Qi W.-b. Hydride-generation methods for determination of lead. Guangpuxue Yu Guangpu Fenxi 1994 14(2) 113. (Dept. Chem. Hangzhou Univ. 310028 Hangzhou China). Sun P.-h.Study on reducing the detection limit of trace rare earth metals in X-ray fluorescence spectrometry. Guangpuxue Yu Guangpu Fenxi 1994 14(2) 121. (Res. Inst. Geol. Miner. Resour. China Natl. Non-Ferrous Met. Ind. Corp. 541004 Guilin China). Burns D. T. Chimpalee N. Harriott M. Applications of a slotted tube atom trap and flame atomic absorption spectrophotometry determination of antimony in copper-based alloys. Fresenius’ J. Anal. Chem. 1994 349 527. (Dept. Anal. Chem. Queen’s Univ. Belfast Belfast UK BT9 5AG). 94551-9900 USA). 9512502 9512503 9512504 9512505 9512506 9512507 9512508 95/2509 9512510 95/25 11 9512512 95/25 13 9512514 95/25 15 Burns D. T. Chimpalee N. Harriott M. Application of a slotted tube atom trap and flame atomic absorption spectrometry determination of tin in copper-based alloys after hydride generation.Fresenius’ J. Anal. Chem. 1994 349 530. (Dept. Anal. Chem. Queen’s Univ. Belfast Belfast UK BT9 5AG). Ashino T. Makabe K. Takada K. Determination of elements in lithium potassium niobate and lithium niobate containing vanadium by ICP-AES. Fresenius’ J. Anal. Chem. 1994 349 772. (Inst. Mater. Res. Tohoku Univ. Miyagi 980-77 Japan). Florian K. Fischer W. Nickel H. Direct solid-sample analysis of silicon carbide powders by dc glow discharge and dc-arc emission spectroscopy. Fresenius’ J. Anal. Chem. 1994 349 174. (Inst. Mater. Energy Systems Res. Centre Julich GmbH 52425 Julich Germany). Reichl B. M. Eisl M. M. Boehmig S. D. Biedermann A. Stori H. Investigation of the segregation on an iron - 3.5 at% silicon bicrystal with AES and STM.Fresenius’ J. Anal. Chem. 1994 349 196. (Inst. Allegemeine Phys. Tech. Univ. Wien 1040 Vienna Austria). Nolte J. Moenke-Blankenburg L. Schumann T. Laser solid sampling for a solid-state detector ICP emission spectrometer. Fresenius’ J. Anal. Chem. 1994 349 131. (Bodenseewerk Perkin-Elmer GmbH 88647 Uberlingen Germany). Chang X.-j. Luo X.-y. Su Z.-x. Zhan G.-y. Gao W.-y. Efficiency of a new poly(acry1amidrazone- hydrazide lacmoid) chelating fibre for pre-concentrating and separating traces of chromium gallium indium and titanium from solutions. Determination by ICP- OES. Fresenius’ J. Anal. Chem. 1994 349 438. (Dept. Chem. Lanzhou Univ. Lanzhou 730000 China). Rodriguez D. Fernandez P. Perez Conde C. Gutierrez A. Camara C. Determination of lead in natural waters using flow injection with online precon- centration and flame AAS detection.Fresenius’ J. Anal. Chem. 1994,349,442. (Dept. Quim. Anal. Fac. Ciencias Quim. Univ. Complutense 28040 Madrid Spain). Liche H. Electron holography for analysis of atomic structures. Fresenius’ J. Anal. Chem. 1994 349 63. (Inst. Angew. Phys. Univ. Tubingen 72076 Tubingen Germany). Broekaert J. A. C. Lathen C. Brandt R. Pilger C. Pollmann D. Tschopel P. Tolg G. Use of plasma atomic spectrometric methods for the analysis of ceramic powders. Fresenius’ J. Anal. Chem. 1994 349 20. (Dept. Chem. Univ. Dortmund 44221 Dortmund Germany). Golloch A. Seidel T. Sliding-spark spectroscopy - a new excitation source for generating atomic emission spectra for analysis.Fresenius’ J. Anal. Chem. 1994 349 32. (Dept. Instrum. Anal. Chem. Univ. Duisburg 47048 Duisburg Germany). Bezsudnov I. V. Atomic absorption spectrophotometers of SOLAAR series with quality certificate IS0 9000. Zauod. Lab. 1994 60 61. (Russia). Zhu LA. Liu H.-m. Zhang J.-l. Li Z.4 Hu Z.-y. ICP-AES determination of trace selenium in steels and heat-resisting alloys. Lihua Jianyan Huaxue Fence 1994 30 171. (Inst. Iron and Steel Eng. Daye Steelworks Huangshi City 435001 China). Zhang J.-k. Zhou Y.4 Luo X.-y. Jin P. FIA-AAS determination of potassium sodium calcium mag- nesium and iron in fluorescent screen glass. Lihua Jianyan Huaxue Fence 1994 30 144. (Dept. Chem. East China Univ. Chem. Technol. Shanghai 200237 China). Li L. Huang G.-q. Graphite furnace AAS determi- nation of traces of chromium(u1) and chromium(rv) after its separation by flotation-coprecipitation with Journal of Analytical Atomic Spectrometry August 1995 Vol.10 237R9512516 9512517 95/25 18 9512519 9512520 9512521 9512522 9 512 5 23 9512524 9512525 9 512 526 9512527 9512528 9512529 238 R ferric hydroxide. Lihua Jianyan Huaxue Fence 1994 30 160. (Environ. Lab. Dept. Chem. Sichuan Univ. Chengdu 610064 China). Maitani T. Xing D. R. Ikeda C. Goda Y. Takeda M. Yoshihira K. Application of ICP atomic emission spectrometry with ultrasonic nebulizer to screen for carmine - determination of aluminium in canned cherries. Shokuhin Eiseigaku Zasshi 1994 35 201. (Natl. Inst. Health Sci. Setagaya-ku Tokyo 158 Japan). Issa Y. M. Ibrahim H. Shoukry A. F. Mohamed S. K.Analytical utility of direct coupled plasma atomic emission spectrometry for the indirect determination of papaverine hydrochloride in pharmaceutical prep- arations. Microchem. J. 1994 50 68. (Chem. Dept. Cairo Univ. Giza Egypt). Chattopadhyay P. Mistry M. Direct flame atomic absorption spectrophotometric determination of major oxides in rock samples of diverse composition using matrix buffer. Microchem. J. 1994 50 78. (Reg. Res. Lab. Bhubaneswar 751013 Orissa India). Greenfield S. Anni Mirabiles. ICP Inf. Newsl. 1994 20 179. (Loughborough Univ. Technol. Loughborough Leics UK LEll 3TU). Broekaert J. A. C. Ideas on twenty years of development in spectrochemical analysis. ICP Inj. Newsl. 1994 20 3. (Dept. Chem. Univ. Dortmund 44221 Dortmund Germany). Kawaguchi H.Twenty years in plasma spectroscopy. ICP Inf. Newsl. 1994 20 184. (Dept. Mater. Sci. and Eng. Nagoya Univ. Nagoya 464-01 Japan). Shrader D. Multi-tasking atomic absorption spec- trometer. Int. Lab. 1994 24 10. (Varian Optical Spectrosc. Instrum Wood Dale IL 60191 USA). Holynska B. Ptasinski J. Wegrzynek D. Software for fundamental-parameter method in energy-dispersive X-ray fluorescence analysis of intermediate-thickness samples. Appl. Radiat. Isot. 1994 45 409. (Fac. Phys. and Nucl. Tech. Univ. Mining and Metall. 30059 Krakow Poland). Hurley P. W. Automatic sample handling systems for X-ray and optical emission spectrometry. Spectrosc. Eur. 1994 6(3) 8. (Philips Anal. X-ray bv 7602 EA Almelo Netherlands). Davidson C. M. Thomas R. P. McVey S. E. Perala R. Littlejohn D.Ure A. M. Evaluation of a sequential extraction procedure for the speciation of heavy metals in sediments. Anal. Chim. Acta 1994 291 277. (Dept. Pure and Appl. Chem. Univ. Strathclyde Glasgow UKG1 1XL). Nimmo M. Fones G. Application of adsorptive cathodic-stripping voltammetry for the determination of copper cadmium nickel and cobalt in atmospheric samples. Anal. Chim. Acta 1994 291 321. (Dept. Environ. Sci. Univ. Plymouth Plymouth UK PL4 8AA). Feng Y.4 Cao J.-p. Simultaneous determination of arsenic(v) and arsenic (ID) in water by inductively coupled plasma atomic emission spectrometry using reduction of arsenic(v) by L-cysteine and a small co-centric hydride generator without a gas-liquid separator. Anal. Chim. Acta 1994,293,211. (Phys. and Chem. Test Centre of Jiangsu Province Nanjing 210002 China).Vinas P. Campillo N. Lopez Garcia I. Hernandez Cordoba M. Slurry atomization of vegetables for the electrothermal atomic absorption-spectrometric analy- sis of lead and cadmium. Food Chem. 1994 50 317. (Dept. Anal. Chem. Univ. Murcia 30071 Murcia Spain). Takatera K. Osaki N. Yamaguchi H. Watanabe T. HPLC-ICP mass spectrometric study of the selenium incorporation into cyanobacterial metallothionein 9512530 9512531 9512532 9 51253 3 9 5/25 34 9 51253 5 9 5/25 36 9 512537 9512538 9512539 9512540 9 51254 1 9512542 9512543 9512544 9512545 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 induced under heavy-metal stress. Anal. Sci. 1994 10 567. (Inst. Ind. Sci. Univ. Tokyo Tokyo 106 Japan). Olesik J. W. Kinzer J.A. Harkleroad B. Inductively coupled plasma optical emission spectrometry using nebulizers with widely different sample consumption rates. Anal. Chem. 1994 66 2022. (Lab. Plasma Spectrochem. Laser Spectrosc. and Mass Spectrom. Dept. Geol. Sci. Ohio State Univ. Columbus OH 43210 USA). Fagioli F. Locatelli C. Landi S. Torsi G. Canas de Moreno F. Lead and cadmium determination in dialysis fluids by atomic absorption spectrometry and differen- tial pulse anodic-stripping voltammetry. Ann. Chim. (Rome) 1994 84 19. (Dept. Chem. Univ. Ferrara 44100 Ferrara Italy). Saouter E. Analyses of organic and inorganic mercury by atomic fluorescence spectrometry using a semiautom- atic analytical system. Anal. Chem. 1994 66 2031. (Center Environ. Diagn. and Bioremediation Univ.West Florida Gulf Breeze FL 32561 USA). Gurvich Y. M. XRF technology for advanced applications. Int. Lab. 1994 24(6) 20. (Fisons Instrum./Kevex Stanford Valencia CA 9 1355 USA). Moffett J. Development of a universal flame atomizer for AAS. Int. Lab. 1994 24(6) 27. (Varian Australia Pty Ltd. Mulgrave Vic. 3 170 Australia). Piorek S. Principles and applications of man-portable X-ray fluorescence spectrometry. TrAC Trends Anal. Chem. (Pers. Ed.) 1994 13 281. (Res. and Technol. Dev. Metorex Inc. Langhorne PA 19047 USA). Fidler R. Schoener A. By-pass for the sampling bottleneck. Analysis Europa 1994 1 39. (CEM Corp. Matthews NC USA). Shuttler I. Schulze H. Multi-element ETAAS becomes a reality. Analysis Europa 1994,1,44. (Atom. Spectrom. Marketing Group Bodenseewerk Perkin-Elmer GmbH Uberlingen Germany). Wagner M.Danzer K. Rapid classification of alloyed steel by means of optical emission spectroscopy and a supervised learning procedure. Talanta 1994 41 1137. (Dept. Inorg. and Anal. Chem. Friedrich Schiller Univ. 07743 Jena Germany). Borszeki J. Halmos P. Gegus E. Karpati P. Application of pressurized sample preparation methods for the analysis of steels and copper alloys. Talanta 1994 41 1089. (Dept. Anal. Chem. Univ. Veszprem 8201 Veszprem Hungary). Horvath Z. Lasztity A. Varga I. Meszaros E. Molnar A. Determination of trace metals and speciation of chromium ions in atmospheric precipitation by ICP- AES and GFAAS. Talanta 1994 41 1165. (Dept. Anal. Chem. Univ. Veszprem 8201 Veszprem Hungary). Fleming J. W. Reference materials - bringing order out of chaos report of a CHEMAC open meeting.Anal. Proc. (London) 1994 31 249. KUSS H.-M. Bossmann D. Miiller M. Silicon determi- nation in steel by ICP-MS. At. Spectrosc. 1994 15 148. (Dept. Anal. Chem. Univ. Duisburg 47048 Duisburg Germany). Barnett W. B. Porter M. K. Kreitzberg C. Designing instrument control software that works. At. Spectrosc. 1994 15 156. (Perkin-Elmer Corp Norwalk CT 06859 USA). Liang L. Danilchik P. Huang Z. Elimination of dependence on experimental conditions in the determi- nation of selenium in water sediment coal and biological samples by hydride generation. At. Spectrosc. 1994 15 151. (Brooks Rand Ltd. Seattle WA 98107 USA). Gluodenis Jr. T. J. Yates D. A. Grosser Z. A. Determination of metals in TCLP extracts using RCRA9512546 9512547 9512548 9512549 95/2550 9512551 9512552 9512553 9512554 9 5/25 55 95/25 56 9512557 9 5/25 5 8 9512559 ICP method 6010.At. Spectrosc. 1994,15,164. (Perkin- Elmer Corp Norwalk CT 06859-0219 USA). Liu M. Y. Determination of sodium in heavy oil by flame atomic absorption and emission methods. Guangpuxue Yu Guangpu Fenxi 1994,14,87. (Res. Inst. Petroleum Refining Factory 050032 Shijiazhuang China). Firestone 0. Direct graphite furnace atomic absorption method for determination of lead in edible oils and 1994 77 951. (Div. Pesticides and Ind. Chem. US Food and Drug Admin. Washington DC 20204 USA). Mindak W. R. Determination of lead in table wines by graphite furnace atomic absorption spectrometry. J. AOAC Int. 1994 77 1023. (Elemental Res.Branch US Food and Drug Admin. Washington DC 20204 USA). Okino A. Ishizuka H. Hirayama I. Nomura Y. Shimada R. Diagnostic measurements of spectral characteristics of a helium ICP with use of an enhanced- vortex-flow torch. Bunseki Kagaku 1994 43 685. (Res. Lab. Nucl. Reactors Tokyo Inst. Technol. Meguro Tokyo 152 Japan). Harada Y. Kurata N. Furuno G. Determination of impurities in sialon by ICP-AES. Bunseki Kagaku 1994 43 649. (Mechanics and Electron. Res. Inst. Fukuoka Ind. Technol. Centre Kitayushu Fukuoka 807 Japan). Esmadi F. T. Attiyat A. D. Indirect determination of carbonate dichromate and oxalate by atomic absorp- tion spectrometry in a flow system using an online preconcentration technique. Anal. Sci. 1994 10 687. (Chem. Dept. Yarmouk Univ. Irbid Jordan).Bannon D. I. Murashchik C. Zapf C. R. Farfel M. R. Chisolm J. J. Jr. Graphite furnace atomic absorp- tion spectroscopic measurement of blood lead in matrix- matched standards. Clin. Chem. (' Winston-Salem N. C . ) 1994 40 1730. (Trace Metals Lab. Kennedy Krieger Inst. Baltimore MD 21213 USA). Sneddon J. Excimer-laser-ablated plasma for direct atomic emission spectrometry of solids. Spectroscopy (Eugene Oreg.) 1994 9 34. (Dept. Chem. McNeese State Univ. Lake Charles LA 70609 USA). Kane J. S. Role of refernece materials in atomic spectroscopy. Spectroscopy (Eugene Oreg.) 1994 9 18. (Natl. Inst. Stand. Technol. Gaithersburg MD 20899 USA). Clement A. Brechet C. Geoffroy M. ICP spectrometry and ultrasonic nebulization. Analusis 1994 22 31 1. (Unite Anal. Minerale INRA-CRF 54280 Seichamps France).Palaniappan R. Ashok K. T. Ram Raj S. K. Improved indirect flameless atomic-absorption spectrophoto- metric method for the determination of palladium in carbenicillin. Pharmazie 1994 49 288. (Elico Private Ltd. Hyderabad 500 018 India). Goodings J. M. Hassanali C. S. Patterson P. M. Chow C. New flame-ion mass spectrometer chemi- ionization of lanthanum observed in hydrogen-oxygen- argon flames. Int. J. Mass Spectrom. Ion Processes 1994 132 83. (Dept. Chem. & Centre Res. Earth & Space Sci. York Univ. North York Ontario Canada M3J 1P3). Drake E. N. Hain T. D. Palladium(11) magnesium(II) and barium(I1) nitrate combinations for matrix modifi- cation in electrothermal atomic absorption measure- ment of total selenium in human urine.Anal. Biochem. 1994 220 336. (Dept. Chem. Angelo State Univ. San Angelo TX 76909 USA). Ruisanchez I. Rius A. Larrechi M. S. Callao M. P. Rius F. X. Automatic simultaneous determination of calcium and magnesium in natural waters with no f2 t s . _ _ r ~ ~ ~ ~ a r y _ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ J..-*4&!,G -&Az+. 9512560 9512561 9512562 9512563 9 512564 9512565 9 5/2 5 66 9512567 95/2568 9512569 9512570 9512571 9512572 9 512 57 3 Journal of Analytical interference separation. Chemom. Intell. Lab. Syst. 1994 24 55. (Dept. Chem. Univ. Rovira Virgili Tarragona 43005 Tarragona Spain). Wyse E. J. Fisher D. R. Radionuclide bioassay by inductively coupled plasma mass spectrometry (ICP-MS). Radiat. Prot. Dosim. 1994 55 199. (Pacific Northwest Lab. Richland WA 99352 USA).Hoffmann E. Leudke C. Scholze H. Stephanowitz H. Analytical investigations of tree rings by laser 253. (Lab. Spektrosk. Methoden Urnweltanal. Inst. Spektrochem. angewandte Spektrosk. D-12489 Berlin Germany). Crews H. M. Ducros V. Eagles J. Mellon F. A. Kastenmayer P. Luten J. B. McGaw B. A. Mass spectrometric methods for studying nutrient mineral and trace element absorption and metabolism in humans using stable isotopes. A review. Analyst (London) 1994 119 2491. (Minist. Agric. Fisheries and Food CSL Food Sci. Lab. Colney Norwich UK NR4 7UQ). Waidmann E. Emons H. Duerbeck H. W. Trace determination of T1 Cu Pb Cd and Zn in specimens of the limnic environment using isotope dilution mass spectrometry with thermal ionization. Fresenius' J. Anal. Chem.1994,350,293. (Inst. Appl. Phys. Chem. Res. Centre Julich D-52425 Julich Germany). Hunter K. Ion detection in ICP-mass spectrometry using active film multipliers. At. Spectrosc. 1994 15 17. (ETP Scientific Inc. Auburn MA 01501 USA). Blake E. Raynor M. W. Cornell D. Determination of organotin compounds by capillary supercritical fluid chromatography with inductively coupled plasma mass spectrometric detection. J . Chromatogr. A 1994 683 223. (Dept. Chem. and Appl. Chem. Univ. Natal King George V Ave. Durban 4001 South Africa). Blake E. Raynor M. W. Cornell D. Combined SFC- ICP-MS. A solution for organometal speciation in environmental samples. Am. Lab. (Shelton Conn.) 1994 26 46. (Dept. Chem. and Appl. Chem. Univ. Natal Durban 4001 South Africa). Stoffel J. J.Waker J. F. Kelley J. M. Bond L. A. Kiddy R. A. Brauer F. P. Environmental monitoring of Hanford nuclear facility effluents by thermal ioniz- ation mass spectrometry. Appl. Spectrosc. 1994 48 1326. (Pacific Northwest Lab. Richland WA 99352 USA). Blades M. W. Atomic mass spectrometry. Appl. Spectrosc. 1994 48 12A. (Dept. Chem. Univ. British Columbia Vancouver British Columbia Canada B6T Dadfarnia S. McLeod C. W. On-line trace enrichment and determination of uranium in waters by flow injection inductively coupled plasma mass spectrometry. Appl. Spectrosc. 1994 48 1331. (School Sci. Sheffield Hallam Univ. Sheffield UK S1 1WB). Takatera K. Osaki N. Yamaguchi H. Watanabe T. Characterization and quantitation of metallothionein isoforms induced in a cyanobacterium using reversed- phase HPLC-ICP mass spectrometry.Anal. Sci. 1994 10,907. (Inst. Ind. Sci. Univ. Tokyo Tokyo 106 Japan). Cromwell E. F. Arrowsmith P. Semi-quantitative analysis with laser ablation inductively coupled plasma mass spectrometry. Anal. Chem. 1995,67 131. (Storage Systems Div. IBM San Jose CA 95193 USA). Popp B. N. Sansone F. J. Rust T. M. Merritt D. A. Determination of concentration and carbon isotopic composition of dissolved methane in sediments and near-shore waters. Anal. Chem. 1995 67 405. (Sch. Ocean and Earth Sci. and Technol. Univ. Hawaii Honolulu HI 96822 USA). Olesik J. W. Kinzer J. A. Olesik S. V. Capillary electrophoresis inductively coupled plasma spec- 2 b l a t i ~ ~ ~ ~ ~ ~ M ~ - F ~ ~ ~ ~ - __ 1Z1). Atomic Spectrometry August 1995 VoZ. 10 239 R9512574 9512575 9 512576 9512577 9512578 9512579 9512580 9512581 9 5/25 82 951258 3 9 512584 9 5/25 8 5 9512586 9 51258 7 240 R trometry for rapid elemental speciation.Anal. Chem. 1995 67 1. (Dept. Geol. Sci. Ohio State Univ. Columbus OH 43210 USA). Abrams S. A. Wen J.-p. O’Brien K. O. Stuff J. E. Liang L. K. Application of magnetic sector thermal ionization mass spectrometry to studies of erythrocyte iron incorporation in small children. Biol. Mass Spectrom. 1994 23 771. (USDA/ARS Children’s Nutr. Res. Center Baylor Coll. Med. and Texas Children’s Hosp. Houston TX 77030 USA). Takaku Y. Masuda K. Kobayashi T. Shimamura T. Determination of arsenic in natural and tap waters by ICP-MS. Bunseki Kagaku 1994 4323 897. (Marubun Corp. Tokyo 136 Japan). Kokelj F.Daris F. Lutmann A. Braida N. Flego R. Nickel chromium and cobalt in toilet soaps analyzed by inductively coupled plasma mass spectrometry. Contact Dermatitis 1994 31 270. (Inst. Dermatol. Univ. Trieste 34139 Trieste Italy). Walker V. R. Sutton R. A. L. Meirav O. Sossi V. Johnson R. Klein J. Fink D. Middleton R. Tissue disposition of 26aluminium in rats measured by acceler- ator mass spectrometry. Clin. Invest. Med. 1994 17 420. (Dept. Med. Univ. British Columbia Vancouver British Columbia Canada). Liao Z.-m. Zhang J.-s. Wu L.-h. Determination of gadolinium and uranium in Gd203-U02 pellets using isotope dilution mass spectrometry. Hedongli Gongcheng 1994 15 351. (Nucl. Power Inst. China Chengdu 610005 China). Xiao Y. K. Liu W. G. Zhou Y. M. Precise measurement of the isotopic composition of cerium and its atomic weight.Int. J. Mass Spectrom. Ion Processes 1994 136 181. (Qinghai Inst. Salt Lakes Acad. Sin. Xining 810008 China). Myers D. P. Li G. Yang P. Hieftje G. M. Inductively coupled plasma-time-of-flight mass spec- trometer for elemental analysis. Part I optimization and characteristics. J. Am. SOC. Muss Spectrom. 1994 5 1008. (Dept. Chem. Indiana Univ. Bloomingon IN USA). Douglas Y. M. Duckworth C. Cable P. R. Marcus K. R. Effects of target gas in collision-induced dis- sociation using a double quadrupole mass spectrometer and radiofrequency glow discharge. J. Am. SOC. Mass Spectrom. 1994 5 845. (Dept. Chem. Clemson Univ. Clemson SC USA). Stoffel J. J. Briant J. K. Simons D. S. Particulate isotopic standard of uranium and plutonium in an aluminosilicate matrix.J. Am. SOC. Mass Spectrom. 1994 5 852. (Pacific Northwest Lab. Richland WA USA). Imakita T. Horii H. Kawamura T. Narita K. Determination of trace amounts of bismuth in iron and steel by inductively coupled plasma-mass spectrometry with sample introduction by electrothermal vaporiz- ation. Proc. Chem. Conf. 1992 44th 44. (Japan). KUSS H.-M. ICP-mass spectrometry - the new gener- ation of analytical methods for rapid multi-element trace analyses. Proc. Chem. Conf. 1992,44th 19. (Univ. Duisburg Germany). Rosamilia J. M. Gas analysis at sub-ppb levels by inductively coupled plasma double focusing mass spectrometry. Proc.-Electrochem. SOC. 1994 94 397. (AT&T Bell Lab. Murray Hill NJ 07974 USA). Ketata K. Pouilloux I.Lebailly J. Ketata M. Debrie R. SIMS comparative analysis of metallic impurity on silicon surface. Proc.-Electrochem. SOC. 1993,93 123. (La3I/LCIA INSA Rouen 76131 Mont- Saint-Aignan France). Rosamilia J. M. Analysis of elemental impurities below a part-per-billion in semiconductor process gases. 95/25 88 9512589 9512590 9512591 9512592 95/2593 9512594 9512595 9 5/25 9 6 9512597 9512598 9512599 9512600 95/2601 9512602 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 Proc.-Inst. Environ. Sci. 1994 Mth 156. (AT&T Bell Lab. Murray Hill NJ 07974 USA). Valkiers S. De Bievre P. Near-absolute (isotope) mass spectrometry isotope abundances (and atomic weight) determinations of nitrogen and oxygen. Process Technol. Proc. 1994 11 953. (Inst. Ref. Mater.and Measure. Comm. Eur. Commun.-JRC B-2440 Geel Belgium). Mauersberger K. Morton J. Schueler B. Anderson S. Mass spectrometric investigations of ozone isotopes. Los Alamos Natl. Lab. [Rep.] LA (U. S.) LA-12522-C 1993 111. (USA). Sargent M. Webb K. Instrumental aspects of induc- tively coupled plasma mass spectrometry. Spectrosc. Eur. 1994 5 21. (Lab. Govern. Chem. Teddington UK TWl1 OLY). Habfast K. Lane H.-J. Magnetic sector mass spec- trometer with very high abundance sensitivity. Los Alamos Natl. Lab. [Rep.] LA (U. S.) LA-12522-C 1993 75. (USA). Tanner S. D. Douglas D. J. French J. B. Gas and ion dynamics of a three-aperture vacuum interface for inductively coupled plasma mass spectrometry. Appl. Spectrosc. 1994 48 1373. (SCIEX Thornhill Ontario Canada L3T 1P2). Tanner S.D. Cousins L. M. Douglas D. J. Reduction of space charge effects using a three-aperture gas dynamic vacuum interface for inductively coupled plasma mass spectrometry. Appl. Spectrosc. 1994 48 1367. (SCIEX Thornhill Ontario Canada L3T 1P2). Wang S. Brown R. Gray D. J. Application of laser ablation-ICP-MS to the spatially resolved micro- analysis of biological tissue. Appl. Spectrosc. 1994 48 1321. (Elemental Research Inc. North Vancouver British Columbia Canada V7M 1A5). Fudge R. Palmer T. J. Pearce N. J. G. Perkins W. T. ICP-MS techniques. Environ. Test. Anal. 1994 3 28. (Inst. Earth Studies Univ. Coll. North Wales Aberystwyth UK). Saumer M. Gantner E. Reinhardt J. Schoof S. Ache H. J. Determination of stable molybdenum isotopes by thermionic mass spectrometry for tracer studies of molybdenum plant metabolism.Plant Soil 1994 163 225. (Inst. Radiochem. Kernforschungs- zentrum Karlsruhe GmbH 76021 Karlsruhe Germany). Graham S. M. Robert R. V. D. Analysis of high- purity noble metals and their salts by ICP-MS. Talanta 1994,41 1369. (Mintek Randburg 2125 South Africa). Noller B. N. Woods P. H. Milne F. J. Identification of contaminants in mine site waste waters by ICP-MS. Publ. Australas. Inst. Min. Metall. 1994 5 495. (Operations Branch Environ. Div. Northern Territory Dept. of Mines and Energy Darwin NT 0801 Australia). Dams R. RNAA as compared to ICP-MS for the analysis of normal human serum. Biol. Trace Elem. Res. 1994 43 539. (Inst. Nucl. Sci. Univ. Ghent B-9000 Ghent Belgium). Chiba M. Shinohara A. Saiki M.Inaba Y. Comparative study of methods for determining lantha- nide elements in biological materials by using NAA HPLC postcolumn reaction and ICP-MS. Biol. Trace Elem. Res. 1994 43 561. (Juntendo Univ. Sch. Med. Tokyo 113 Japan). Ito T. Mikami Y. Kozono S. Odawara 0. Glow discharge mass spectrometry for solid insulator mate- rials. Jpn. Kokai Tokkyo Koho JP 06,258,286 [94,258,286] (Cl. GOlN27/62) 16 Sep 1994 Appl. 93146,883 08 Mar 1993; 5pp. (Showa Denko Kk Japan). De Bievre P. Perrin R. E. Why higher abundance sensitivities on commercial mass spectrometers?. Los9512603 9512604 9512605 9512606 9512607 9 512608 9512609 9512610 951261 1 9512612 95/26 13 9512614 9512615 9512616 95/26 17 Alamos Natl. Lab. [Rep.] LA (U. S.) LA-12522-CY 1993 5. (Central Bur.Nucl. Measure. Comm. Eur. Commun. B-2440 Geel Belgium). Schroeder N. C. Rokop D. J. Wolfsberg K. Negative- ion mass spectrometry of technetium. Los Alamos Natl. Lab. [Rep.] LA (U. S.) LA-12522-C 1993,165. (USA). Green L. W. TIMS and RIMS applications in the nuclear industry. Los Alamos Natl. Lab. [Rep.] LA Westgate J. A Perkins W. T. Fuge R. Pearce N. J. G. Wintle A. G. Trace-element analysis of volcanic glass shards by laser ablation inductively coupled plasma mass spectrometry application to tephrochron- ological studies. Appl. Geochem. 1994 9 323. (Dept. Geol. Univ. Toronto Toronto Ontario Canada M5S 3B1). Jiang S.-s. Jiang S. Guo H. Du S.-b. Yang B.-f. Huang Q. Li C.-f. Wang P.-y. Determination of 36Cl in the natural samples by accelerator mass spectrometry.Fenxi Ceshi Xuebao 1994 13 13. (China Inst. At. Energy Beijing 102413 China). Warren A. R. Allen L. A. Pang. H.-M. Houk R. S. Janghorbani M. Simultaneous measurement of ion ratios by inductively coupled plasma mass spectrometry with a twin-quadrupole instrument. Appl. Spectrosc. 1994 48 1360. (Ames Lab. Iowa State Univ. Ames IA 50011 USA). Agnes G. R. Stewart 1. I. Horlick G. Elemental speciation measurements with electrospray mass spec- trometry as assessment. Appl. Spectrosc. 1994 48 1347. (Dept. Chem. Univ. Alberta Edmonton Alberta Canada T6G 2G2). Haggarty P. Franklin M. F. Fuller M. F. McGaw B. A. Milne E. Duncan G. Christie S. L. Smith J. S. Validation of the doubly-labelled water method in growing pigs. Am. J. Physiol. 1994,267 R1574. (Rowett Res. Inst. Bucksburn Aberdeen UK AB2 9SB).Park K. S. Uh H. Principles and applications of accelerator mass spectrometry. Anal. Sci. Techno!. 1994 7 69A. (Hankuk Zawon Yunkaso South Korea). Takahashi T. Takaku Y. Masuda K. Shimamura T. Multi-elemental semi-quantitative analyses of sus- pended particulate matter by glow discharge MS. Bunseki Kagaku 1994,43,1083. (Appl. Team Marubun Corp. Tokyo 136 Japan). Potter D. ICP-MS instrument for the modern labora- tory. Am. Lab. (Shelton Conn.) 1994 26 35. (Hewlett Packard Co. Wilmington DE 19808 USA). Irnai N. Yamamoto M. Direct analysis of laminated dolomite and zircon by laser ablation inductively coupled plasma mass spectrometry. Microchem. J. 1994 50 281. (Geol. Survey Japan Ibaraki 305 Japan). Wiedemann B. Bethge K. Schuetze W.Lambert U. Pahlke S. Reinhold T. Weinert B. Flade T. Radiofrequency spark source mass spectrometry analy- sis of oxygen in undoped silicon crystals and of carbon in undoped and carbon-doped gallium arsenide crystals. Fresenius’ J. Anal. Chem. 1994 350 319. (Inst. Kernph y s D- 6048 6 Frankfurt Germany). Becker S. Hirner A. V. Coupling of inductively coupled plasma mass spectrometry (ICP-MS) with electrothermal vaporization (ETV). Fresenius’ J. Anal. Chem. 1994 350 260. (Inst. Environ. Anal. Chem. Univ. Essen D-45 117 Essen Germany). Raith A Hutton R. C. Quantitation methods using laser ablation ICP-MS. Part 1 Analysis of powders. Fresenius’ J. Anal. Chem. 1994 350 242. (Fisons Instruments Elemental Analysis Cheshire UK CW7 3BX). Venzago C. Weigert M. Application of the glow discharge mass spectrometry (GDMS) for the multi- (U.S.) LA-12522-C 1993 53.(USA). 9512618 9512619 9512620 9512621 9512622 9512623 9512624 9512625 9512626 9512627 9512628 9512629 9512630 9512631 element trace and ultra-trace analysis of sputtering targets. Fresenius’ J. Anal. Chem. 1994,350 303. (Corp. Res. Functions Degussa AG D-63457 Hanau Germany). Garbe-Schoenberg C.-D. McMurty G. M. In-situ micro-analysis of platinum and rare earths in ferro- manganese crusts by laser ablation-ICP-MS (LA-ICP-MS). Fresenius J. Anal. Chem. 1994 350 264. (Geo1.-Paloaontol. Inst. Univ. Kiel D-24118 Kiel Germany). Scholze H. Stephanowitz H. Hoffmann E. Skole J. Element analysis of inhomogeneous samples by laser ablation ICP mass spectrometry. Fresenius’ J. Anal. Chem.1994 350 247 (Inst. Spektrochem. u. Angew. Spektrosk. (ISAS) D- 12489 Berlin Germany). Seubert A. Online coupling between chromatography and inductively coupled plasma mass spectrometry - a current assessment. Fresenius ‘ J. Anal. Chem. 1994 350,210. (Inst. Anorg. Chem. Univ. Hannover D-30167 Hannover Germany). Turteltaub K. W. Vogel J. S. Felton J. S. Gledhill B. L. Davis J. C. Method for detection of long-lived radioisotopes in small biochemical samples. U.S. US Appl. 553,080 13 Jul 1990; 14pp. (Reagents of the Univ. California). Chikuma M. Aoki H. Tanaka T. Tanaka H. Determination of trace tellurium by graphite furnace atomic absorption spectrometry combined with separa- tion and preconcentration using a tellurium(rv)-selective chelate forming resin. Biomed.Res. Trace Elem. 1993 4 53. (Div. Anal. Chem. Univ. Pharm. Sci. Osaka Japan). Ohta K. Yokoyama M. Itoh S.-i. Kaneco S. Mizuno T. Determination of aluminium in biological materials by electrothermal atomic absorption spectrometry with a tungsten tube atomizer. Anal. Chim. Acta 1994 291 115. (Dept. Chem. Mater. Fac. of Eng. Mie Univ. TSU Mie Japan). Halbach S. Determination of mercury released from dental amalgam. Ger. DE 4,323,072 (Cl. G01N33/20) 21 Jul 1994 Appl. 10 Jul 1993; 3 pp. (Forschungs- zentrum fur Umwelt und Gesundheit GmbH). Leyssac P. P. Christensen P. Comparison between endogenous and exogenous lithium clearance in the anaesthetized rat. Acta Physiol. Scand. 1994 151 173. (Dept. Med. Physiol. Univ. Copenhagen Denmark). Schlager K. J. Instrumentation for plant health and growth.Adu. Space Res. 1994 14 227. (Biotronics Technol. Inc Waukesha WI 53186 USA). Lopez-Molinero A. Gascon J. Determination of sel- enium in soil by continuous hydride generation- inductively coupled plasma atomic emission spec- trometry. Afinidad 1994 51 291. (Fac. Sci. Univ. Zaragoza Zaragoza Spain). Pig-Deu M. Lamuela-Raventos R. M. Buxaderas S. Torre-Boronat C. Determination of copper and iron in must comparison of wet and dry ashing. Am. J. Enol. Vitic. 1994 45 25. (Fac. Pharm. Univ. Barcelona Barcelona 08028 Spain). Vargas E. J. Shoho A. R. Linder M. C. Copper transport in the Nagase analbuminaemic rat. Am. J. Physiol. 1994 267 G259. (Dept. Chem. California State Univ. Fullerton CA 92634 USA). Kaminska O. Pawlicki K. Assessment of activity of chosen marker enzymes in the stomach of pregnant female rats as dependent on the degree of cadmium accumulation.Ann. Acad. ed. Silesiensis 1992 26 65. (Katedra Nauk Biol. Akad. Wychow Fiz. w Katowicach 40-065 Katowice Poland). Lindstriim P. Olsson P. Malmqvist J. Pettersson J. Lemmen P. Werner B. Sjoberg S. O h A. Carlsson 5,366,721 (Cl. 424-1.11; A61K43/00) 22 NOV 1994 US Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 241 R95/2632 9512633 9512634 9512635 9512636 9512637 9512638 9512639 9512640 9512641 9512642 9512643 242 R J. New carborane-based compounds for boron neutron capture therapy binding and toxicity of NAC-1 DAC-1 and B-Et-11-OMe in cultured human glioma and mouse melanoma cells.. Anti-Cancer Drugs 1994 5 43. (Dep. Radiat.Sci. Uppsala Univ. S-751 21 Uppsala Sweden). Favretto L. Vijnovic D. Campisi B. Chemometric studies on minor and trace elements in cow’s milk. Anal. Chim. Acta 1994 293 295. (Dipt. Econom. e Merceol. Risor. Nat. Prod. Univ. Trieste Trieste Italy). Halonen P. Hyvariaen M. Kauppi M. Emission related and repeated monitoring of element concen- trations in the epiphytic lichen Hypogymnia physodes in a coastal area W Finland. Ann. But. Fenn. 1993 30 251. (Dept. Bot. Univ. Oulu FIN-90570 Oulu Finland). Reis B. F. Gine M. F. Zagatto E. A. G. Lima J. L. F. C. Lapa R. A. Multicommutation in flow analysis. Part 1. Binary sampling concepts instrumentation and spectrophotometric determination of iron in plant digests. Anal. Chim. Acta 1994 293 129. (Centro Energia Nucl. Agric.Univ. Sao Paulo Box 96 13418-260 Piracicaba SPY Brazil). Siles Cordero M. T. Garcia de Torres A. Cano Pavon J. M. Solvent extraction of cadmium as a previous step for its determination in biological samples by induc- tively coupled plasma atomic emission spectrometry. Anal. Lett. 1994 27 1689. (Fac. Sci. Univ. Malaga Malaga 29071 Spain). Leclerc F. Deruaz D. Bander A Brazier J. L. Limit of detection of I3C using an atomic emission detector (MIP) coupled to gas chromatography. Anal. Lett. 1994 27 1325. (Lab. Etudes Anal. Cinet. Med. Inst. Sci. Pharm. Biol. 69373 Lyon France). Tummalapalli C. M. Williams J. C. Stern T. N. Micro analytical method for the determination of selenium in bovine heart tissue using Zeeman graphite furnace atomic absorption spectrophotometry.Anal. Lett. 1994 27 2091. (Dept. Chem. Memphis State Univ. Memphis TN USA). Granadillo V. A. de Machado L. P. Romero R. A. Determination of total chromium in whole blood blood components bone and urine by fast furnace program electrothermal atomization AAS and using neither analyte isoformation nor background correction. Anal. Chem. 1994 66 3624. (Fac. Exp. Ciencias Univ. Zulia Maracaibo Venezuela). Thienpont L. M. Van Nuwenborg J. E. Stoeckl D. Ion chromatography as potential reference method- ology for the determination of total calcium and magnesium in human serum. Anal. Chem. 1994 66 2404. (Lab. Anal. Chem. Univ. Ghent B-9000 Ghent Belgi um). Yousfi I. Bermond A. Application of differential pulse anodic stripping voltammetry for analysis of soil samples in a barium perchlorate medium.Analusis 1994 22 343. (Lab. Chim. Anal. Inst. Natl. Agronom. Paris-Grignon 7523 1 Paris France). Hoedg M. Dheere 0. Fast programmes in electrother- mal atomic absorption spectrometry. Validation of trace element analysis in plants. Analusis 1994 22 135. (Inst. Rech. Chim. Minist. Agric. B-3080 Tervuren Belgium). Lan W. G. Wong M. K. Chen N. Sin Y. M. Orthogonal array design as a chemometric method for the optimization of analytical procedures. Part 2. Four- level design and its application in microwave dissolution of biological samples. Analyst (London) 1994 119 1669. (Dept. Chem. Natl. Univ. Singapore Singapore 051 1 Singapore). Arruda M. A. Z. Quintela M. J. Gallego M. Valcarcel M. Direct analysis of milk for aluminium using electrothermal atomic absorption spectrometry.9512644 9512645 9512646 9512647 9512648 9512649 9512650 9512651 9512652 9 5/26 5 3 9512654 9512655 9 5/26 5 6 Journal of Analytical Atomic Spectrometry August 199f’ Vol. 10 Analyst (London) 1994 119 1695. (Fac. Sci. Univ. Cordoba Cordoba E-14004 Spain). Lan W. G. Wong M. K. Chen N. Sin Y. M. Orthogonal array design as a chemometric method for the optimization of analytical procedures. Part 1. Two- level design and its application in microwave dissolution of biological samples. Analyst (London) 1994 119 1659. (Dept. Chem. Natl. Univ. Singapore Singapore 051 1 Singapore). Baldwin S. Deaker M. Maher W. Low-volume microwave digestion of marine biological tissues for the measurement of trace elements. Analyst (London) 1994 119 1701.(Fac. Appl. Sci. Univ. Canberra Belconnen 2616 Australia). Dorn S. B. Frame E. M. S. Development of a high-performance liquid chromatographic-inductively coupled plasma method for speciation and quantifi- cation of silicones from silanols to polysiloxanes. Analyst (London) 1994 119 1687. (GE Corporate Research Development Schenectady NY 12301 USA). Amarasiriwardena D. Krushevska A Argentine M. Barnes R. M. Vapour-phase acid digestion of micro samples of biological material in a high-temperature high-pressure asher for inductively coupled plasma atomic emission spectrometry. Analyst (London) 1994 119 1017. (Sch. Nat. Sci. Hampshire Coll. Amherst MA 01002 USA). Cullen W. R. Harrison L. G. Li H. Hewitt G. Bioaccumulation and excretion of arsenic compounds by a marine unicellular alga Polyphysa peniculus. Appl.Organomet. Chem. 1994 8 313. (Dept. Chem. Univ. British Columbia Vancouver British Columbia Canada V6T 1Z1). Cullen W. R. Li H. Hewitt G. Reimer K. J. Zalunardo N. Identification of extracellular arsenical metabolites in the growth medium of the microorgan- isms Apiotrichum humicola and Scopulariopsis brev- icaulis. Appl. Organomet. Chem. 1994 8 303. (Dept. Chem. Univ. British Columbia Vancouver British Columbia Canada V6T 1Z1). Hart R. A. Kallio P. T. Bailey J. E. Effect of biosynthetic manipulation of heme on insolubility of Vitreoscilla hemoglobin in Escherichia coli. Appl. Enuiron. Microbiol. 1994 60 2431. (Div. Chem. Chem. Eng. California Inst. Technol. Pasadena CA 9 1125 USA). Carbonell G. Tarazona J.V. Toxicokinetics of copper in rainbow trout (Oncorhynchus mykiss). Aquat. Toxicol. 1994 29 213. (Div. Environ. Toxicol. Centro Invest. Sanidad Animal CISA-INIA ES-28 130 Valdeolmos Madrid Spain). Taufer I. Tauferova J. Design of evaluation of assays of trace elements in a fossil bone. Archaeometry 1994 36 93. (Univ. Chem. Technol. Pardubice 53210 Czech Republic). Pollard A. M. Hatcher H. Chemical analysis of oriental ceramic body compositions Part 1. Wares from north China. Archaeometry 1994 36 41. (Res. Lab. Archaeol. and Hist. Art. Univ. Oxford Oxford UK OX1 345). Guitart R. To-Figueras J. Mateo R. Bertolero A Cerradelo S. Martinez-Vilalta A. Lead poisoning in waterfowl from the Ebro Delta Spain calculation of lead exposure thresholds for mallards. Arch. Enuiron.Contam. Toxicol. 1994 27 289. (Lab. Vet. Toxicol. Autonomous Univ. Barcelona Bellaterra 08193 Spain). Liu X.-y. Lin Y. Jiang M.-j. Wu W.-z. Ni G.-h. Determination of six trace elements in serum of diabetes child by ICP-AES. Beijing Gongye Dame Xuebao 1993 19 91. (Dept. Chem. Environ. Eng. Beijing Polytech. Univ. Beijing China). Elsenhams B. Kolb K. Schumann K. Forth W. Longitudinal distribution of cadmium zinc copper,9 5/26 5 7 9512658 9512659 9512660 9512661 9512662 9512663 9512664 9512665 9512666 9512667 9512668 9 512669 iron and metallothionein in the small-intestinal mucosa of rats after administration of cadmium chloride. Biol. Trace Elem. Res. 1994 41 31. (Walther Straub Inst. Pharm. Toxicol. Ludwig-Maximillians Univ. Miinchen D-80336 Muchen Germany).Giles L. Smiciklas-Wright H. Fosmire G. Derr J. Variations in plasma zinc in older men and women. Biol. Trace Elem. Res. 1994 41 235. (Nutr. Dept. Pennsylvania State Univ. University Park PA Sahin G. Varol I. Temizer A Benli K. Demirdamar R. Duru S. Determination of aluminium levels in the kidney liver and brain of mice treated with aluminium hydroxide. Biol. Trace Elem. Res. 1994 41 129. (Dept. Pharm. Toxicol. Hacettepe Univ. Ankara Turkey). Gibello A. Ferrer E. Martin M. Garrido-Pertierra A. 3,4-Dihydroxyphenylacetate 2,3-dioxygenase from Klebsiella pneumoniae a Mg2+ -containing dioxygenase involved in aromatic catabolism. Biochem. J. 1994 30 145. (Fac. Vet. Univ. Complutense Madrid 28040 Spain). Yoshioka M. Narai N. Shinkai A. Tokuda T. Saito K. Shioya M.Tokoro N. Kono Y. Analyses of metal ions in spider venoms in relation to the insecticidal activity of clavamine. Biol. Pharm. Bull. 1994 17 472. (Fac. Pharm. Sci. Setsunan Univ. Hirakata 573-01 Japan). Shinohara A. Chiba M. Inaba Y. Effects of adminis- atration of rare earth elements on concentrations of essential elements in organs of mice. Biomed. Res. Trace Elem. 1993 4 115. (Dept. Hyg. Juntendo Univ. Sch. Med. Japan). Tanaka T. Masuda H. Trace element concentrations in human permanent teeth by dental disease. Biomed. Res. Trace Elem. 1993 4 213. (Dept. Surg. Kyushu Dent. Coll. Japan). Sakurai H. Kamada H. Satoh H. Nakajima K. Kimura M. Odaki N. Kawano K. Hagino T. Distribution of bio-trace elements and induction of copper-metallothionein in the liver of LEC rats. Biomed.Res. Trace Elem. 1993 4 145. (Dept. Anal. Chem. Kyoto Pharm. Univ. Kyoto 607 Japan). Tsunoda T. Watanabe M. Takahashi O. Kubono K. Tsukada Y. Nakazato H. Tomita H. Measurement of the zinc level in leukocytes. Biomed. Res. Trace Elem. 1993 4 55. (SRL Inc. Japan). Takahashi Y. Hasegawa J. Organ distribution of mercury released from dental amalgam. Biomed. Res. Trace Elem. 1993 4 119. (Sch. Dent. Aichi-Gakuin Univ. Japan). Yamamoto K. Isegawa J. Terashima K. Sato M. Kobayashi H. Sando K. Nezu R. Takagi Y. Okada A. Selenium determination of plasma in patients receiving long-term home parenteral nutrition and enteral nutrition by hydrogen generated atomic absorp- tion spectrometry. Biomed. Res. Trace Elem. 1993 4 189. (Res. Lab. Roussel Morishita Co. Ltd.Yasug 520-23 Japan). Morita A. Kimura M. Itokawa Y. Effect of age and sex on trace elements in mice. Biomed. Res. Trace Elem. 1993 4 199. (Grad. Sch. Med. Kyoto Univ. Kyoto Japan). Hirano Y. Nakamyra H. Yonetani A. Yasuda K. Direct determination of trace elements by using multi- loading technique in graphite furnace atomic absorption spectrometry. Biomed. Res. Trace Elem. 1993 4 51. (Instrum. Div. Hitachi Ltd. Japan). Ikeuchi I. Fujisaka I. Suzuki Y. Fujimotot K. Kitagawa T. HPLCIICP-AES method for the simul- taneous determination of cis-diammine (glycolato) plati- num and its metabolite in urine. Biomed. Res. Truce Elem. 1993 4 49. (Shionogi Res. Lab. Shionogi and Co. Ltd. Japan). 16802-6504 USA). 9512670 9512671 9512672 9512673 9512674 9512675 9512676 95/2677 9512678 9512679 9512680 951268 1 9512682 9512683 95/2684 Journal of Analytical Suzuki S.Ogawa Y. Concentration of elements in the organs of rats by ICP-AES. Biomed. Res. Trace Elem. 1993 4 197. (Biol. Saf. Centre Natl. Inst. Hyg. Sci. Japan). Casez J.-P. Miihlbauer R. C. Lippuner K. Kelly T. Fleisch H. Jaeger P. Dual-energy X-ray absorptiome- try for measuring total bone mineral content in the rat study of accuracy and precision. Bone Miner. 1994 26 61. (Policlinic Med. Bern Switzerland). Ma J. Verweij J. Kolker H. J. van Ingen H. E. Stoter G. Schellens J. H. M. Pharmacokinetic- dynamic relationship of cisplatin in uitro simulation of an iv bolus and 3 h and 20 h infusion. Br. J. Cancer 1994 69 858. (Dr. Daniel den Hoed Klin. Rotterdam Cancer Inst. 3008 AE Rotterdam Netherlands).Flalndysz J. Kotecka W. Manganese copper zinc and iron content of fruits cultivated in the province of Gdansk and Elblag. Bromatol. Chem. Toksykol. 1993 26 171. (Wydzialu Chem. Univ. Gdansk Gdansk Poland). Falandysz J. Kotecka W. Manganese copper zinc and iron content of apples. Bromatol. Chem. Toksykol. 1993 26 289. (Wydzialu Chem. Univ. Gdansk Gdansk Poland). Falandysz J. Kotecka W. Manganese copper zinc and iron content of nuts almonds raisins and cacao. Bromatol. Chem. Toksykol. 1993 26 285. (Wydzialu Chem. Univ. Gdansk Gdansk Poland). Falandysz J. Kotecka W. Manganese copper zinc and iron content of tea infusions of different strength. Bromatol. Chem. Toksykol. 1993 26 165. (Wydzialu Chem. Univ. Gdansk Gdansk Poland). Ivanova E. H. Soil analysis.Atomic absorption spectro- metric determination of the toxic pollutants arsenic thallium and cadmium. Bulg. Chem. Commun. 1993,26 104. (Inst. Gen. Inorg. Chem. 11 13 Sofia Bulgaria). Golow A. A. Laryea J. N. Levels of iron silver zinc and lead in oranges and avocados from two gold-rich towns compared with levels in an adjacent gold- deficient town. Bull. Environ. Contam. Toxicol. 1994 53 332. (Dept. Chem. Univ. Sci. and Technol. Kumasi Ghana). Kashuba-Hockenberry L. A. DeWalle D. R. Dendrochemical response to soil liming in scarlet oak. Can. J. For. Res. 1994 24 564. (Environ. Resour. Res. Inst. and Sch. Forest Resour. Pennsylvania State Univ. University Park PA 16802 USA). Mandolfino M. Cimino G. Scuteri A Cordi R. Romano L. Some aspects of zinc transport across eel (Anguilla anguilla) red blood cell membranes.Cell Biol. Znt. 1994 18 279. (Inst. Gen. Physiol. Univ. Messina Italy). Riccardi R. Riccardi A. Lasorella A. Di ROCCO C. Carelli G. Tornesello A. Servidei T. Iavarone A. Mastrangelo R. Clinical pharmacokinetics of carbopla- tin in children. Cancer Chemother. Pharmucol. 1994 33 477. (Div. Pediatr. Oncol. Cathol. Univ. 1-00168 Rome Italy). Stewart D. J. Dulberg C. Molepo J. M. Mikhael N. Z. Montpetit V. A. J. Redmond M. D. Goel R. Factors affecting human autopsy kidney-cortex and kidney-medulla platinum concentrations after cisplatin administration. Cancer Chemother. Pharmacol. 1994 34 14. (Ottawa Reg. Cancer Centre Ontario Cancer Treat. and Res. Found. Ottawa Ontario Canada K1Y 4K7). Johansson C. G. Aluminium determination in beer using graphite furnace atomic absorption spectrophoto- metry.Cerueza Malta 1994 31 57 (EBC Spain). Mo S.-j. Song J.-y. Lin 2.-x. Tong Y.-w. Study of the background absorption of slurry algae in graphite furnace atomic absorption spectrometry. Chem. Res. Atomic Spectrometry August 1995 Vol. 10 243 R9512685 9 5/26 8 6 9512687 9512688 9512689 9512690 9512691 9512692 9512693 9512694 9512695 9512696 9512697 9512698 244 R Chin. Univ. 1993 9 256. (Dept. Chem. South China Normal Univ. Guangzhou 510631 China). Araujo A. N. Jun S. Lima J. L. F. C. Simultaneous biparametric determination of total calcium and potass- ium in biological fluids by flow injection analysis - use of Powell’s method in the system optimization. Chem. Res. Chin. Univ.1994 10 5. (Fac. Pharm. Univ. Porto Oporto 4000 Portugal). Scarano G. Morelli E. Voltammetric study of copper- ion binding to the cell surface of the marine alga Phaeodactylum tricornutum. Chem. Speciation Bioauailability 1993 5 129. (Consiglio Nazionale delle Ric. Inst. Biophys. 26-56127 Pisa Italy). Min B. K. Park J. D. Hong Y. P. Chang I. W. Contents of nickel chromium and cadmium in indoor air of dental laboratory and in blood of dental technicians. Chungang Uidaechi 1993 18 387. (Coll. Med. Chung-Ang Univ. Seoul 156-756 South Korea). Sampson M. Ruddel M. Elin R. J. Lithium determi- nations evaluated in eight analysers. Clin. Chem. (Winston-Salem N. C . ) 1994 40 869. (Clin. Pathol. Dept. Warren Grant Magnuson Clin. Centre Bethesda MD 20892 USA). Puchades R.Llopis A. Raigon M. D. Peris-Tortajada M. Maquieria A. Simplified method for the extraction and analysis of available nitrogen phosphorus and potassium in soils. Commun. Soil Sci. Plant Anal. 1994 25 2543. (Dept. Chem. Polytech. Univ. Valencia Valencia 46071 Spain). Fridlund S. Littlefield S. Rivers J. Use of modified microwave digestion/dissolution for the quantitative determination of aluminium silicon and iron in biological materials by inductively coupled plasma spectrometry. Commun. Soil Sci. Plant Anal. 1994 25 933. (Div. Agric. Nat. Resour. Anal. Lab. Univ. California Davis CA 95616 USA). Macrae R. Petracco M. Illy E. Trace metal profiles of green coffees. Colloq. Sci. Znt. Cafe [C. R . ] 1993 15th 650. (Analytica Eastwood Walkington Beverley UK HU17 8RP).Young J.-T. Spectroscopic characterization of interphases between polymers and metal substrates. Diss. Abstr. Int. By 1994 55 446. (Univ. Cincinnati Cincinnati OH USA). Moharram M. A Ibrahim J. M. Hegazy A Hussin A. A. Moharram A. A. Spectroscopic study of organic and inorganic constituents of malignant bladder’s tissues. Delta J. Sci. 1992 16( 3) 45. (Spectrosc. Dept. Natl. Res. Centre Dokki Egypt). Arellano J. B. Baron M. Chueca A Lachica M. Determination of copper in different chloroplast prep- arations. Dev. Plant Soil Sci. 1993 53 25. (Estac. Exp. Zaidin CSIC Granada 18008 Spain). Van Steveninck R. F. M. Babare A. Fernando D. R. Van Steveninck M. E. Binding of zinc in root cells of crop plants by phytic acid. Deu. Plant Soil Sci. 1993 54 775. (Sch. Agric.La Trobe Univ. Bundoora 3083 Australia). Linkerhaegner M. Stan H. J. Residue behaviour of vinclozolin and dichlofluanid fungicides on strawberries. Dtsch. Lebensm.-Rundsch. 1993 89 143. (Inst. Lebensmittelchem. Tech. Univ. Berlin W- lo00 Berlin 65 Germany). Szakmary E. Ungvary G. Naray M. Tatrai E. Szeberenyi S. Morvai V. Effect of cobalt on the prenatal development of mouse rat and rabbit. Egeszsegtudomany 1994 38 126. (Orszagos Munka-es Uzemegeszsegugyi Intezet. Semmelweis Orvostudo- manyi Egyetem 11 Budapest Hungary). Jagner D. Renman L. Wang Y.d. Determination of lead in microlitre amounts of whole blood by stripping potentiometry. Electroanalysis ( N . Y.) 1994 6 285. 95/2699 9512700 9512701 9512702 9512703 9512704 9512705 9512706 9512707 9512708 9512709 9512710 951271 1 95/27 12 Journal of Analytical Atomic Spectrometry August 1995’ Vol.10 (Dept. Anal. Mar. Chem. Univ. Goteborg S-412 96 Goteborg Sweden). Bihoreau N. Pin S. de Kersabiec A.-M. Vidot F. Fontaine-Aupart M.-P. Copper-atom identification in the active and inactive forms of plasma-derived FVIII and recombinant FVIII-AII. Eur. J. Biochem. 1994 222 41. (Centre Natl. Transf. Sanguine Inst. Mer. Les Ulis France). Saur P. M. M. Zielmann S. Roth A. Frank. L. Warneke G. Ensink F.-B. M. Radke A. Comparison of the determination of magnesium by methylthymol blue spectrophotometry and atomic absorption spectrophotometry. Eur. J. Clin. Chem. Clin. Biochem. 1994 32 539. (Zentrum Anaesthesiol. Rettungs- Intensivmed. Georg August Univ. Gottingen Germany). Le S. X. C. Cullen W. R.Reimer K. J. Speciation of arsenic compounds in some marine organisms. Environ. Sci. Technol. 1994 28 1598. (Dept. Chem. Univ. British Columbia Vancouver British Columbia Canada V6T 1Z1). Zhang Y. F. Itai K. Sakurai S. Tsunoda H. Distribution of arsenic in the brain of mice administered As,O,. Enuiron. Sci. (Tokyo) 1992 1 191. (Sch. Med. Iwate Med. Univ. Morioka Japan). Yuan Q.-h. Microsampling-successive determination of trace elements in forage grass by flame atomic absorp- tion spectrophotometry. Fenxi Ceshi Xuebao 1993 12(6) 60. (Ningxia Anal. and Test Centre 750021 China). Lin J.-m. Zhuang Z. Yang P.-y. Yuan D.-x. Yan X.-m. Huang B.4. Multi-element speciation analysis of aqueous tea leaching solution by FIA-ICP/AES. Fenxi Ceshi Xuebao 1993 12(6) 49.(Dept. Chem. Xiamen Univ. Xiamen 361005 China). Moreno-Rojas R. Pozo-Lora R. Zurera-Cosano G. Amaro-Lopez M. A. Calcium magnesium manganese sodium and potassium variations in Manchego-type cheese during ripening. Food Chem. 1994 50 373. (Dept. Food Hyg. Technol. Univ. Cordoba Cordoba 14005 Spain). Zurera-Cosano G. Moreno-Rojas R. Amaro-Lopez M. Effect of processing on contents and relationships of mineral elements of milk. Food Chem. 1994 51 75. (Dept. Food Hyg. Technol. Univ. Cordoba Cordoba 14005 Spain). Pauwels J. Lamberty A. De Bievre P. Grobecker K.H. Bauspiess C. Certified reference materials for the determination of cadmium in polyethylene. Fresenius’ J. Anal. Chem. 1994 349 409. (Inst. Ref. Mater. Measure. B-2440 Geel Belgium). Lange-Hew K. Dunemann L.Schwedt G. Properties and binding forms of cadmium and nickel in protein extracts from bean seeds (Phaseolus uulgaris I,.). Fresenius’ J. Anal. Chem. 1994,349,460. (Bodenseewerk Perkin-Elmer GmbH D-40549 Dusseldorf Germany). Evans S. Kraehenbuehl U. Boron analysis in biological material microwave digestion procedure and determi- nation by different methods. Fresenius ’ J. Anal. Chem. 1994 349 454. (Inst. Anorg. Anal. Phys. Chem. Univ. Berne CH-3000 Berne Switzerland). Lin L.q. Potassium concentration in bone of Beljing residents. Fushe Fanghu 1994 14 50. (Beijing Public Health Anti-Epidemic Inst. 10013 China). Lin W.-y. He Y.-z. Luo J.-h. Lin K. Huang L.-j. Huang W.-q. Wu K.-g. Mo C.-z. Determination of silicon in blood by optical temperature control Zeeman GFAAS.Guangpuxue Yu Guangpu Fenxi 1994 14( 3) 93. (Guangxi Instrum. Anal. Res. Center Nanning 530022 China). Golow A. A. Concentration of some heavy metals in Dioscorea alata (Linn) yam Musa paradisiaca (Linn)9512713 9512714 9512715 9512716 95/2717 95/27 18 9512719 9512720 9512721 9512722 9512723 9512724 9512725 9512726 plantain and Manihot utilissima (Pohl) cassava in three markets in Kumasi City of Ghana. Ghana J. Chem. 1993 1 365. (Dept. Chem. Univ. Sci. Technol. Kumasi Ghana). Oshima H. Kondo F. Analysis of heavy metals (inorganic substances - lead cadmium etc.). Gekkan Fudo Kemikaru 1994 10 100. (Aichi Prefect. Inst. Public Health Nagoya 462 Japan). Tietz U. Ocker H. D. Bruggemann J. Pesticides and heavy metals in German cereals. Getreide Mehl Brot 1993 47 1.(Inst. Getreideverarb. GmbH 0-1505 Bergholz-Rehbruecke Germany). Stafilov T. Rizova V. Determination of lead in cereals by electrothermal atomic absorption spectrometry. Glas. Hem. Tehnol. Maked. 1992 11 37. (Fac. Sci. Sv. Kiril i Metodij Univ. 91000 Skopje Yugoslavia). Reichelt L. Kluge I. Plant analysis by induct- ively coupled plasma atomic emission spectroscopy Bodenkd./Forschungslab. Forstl. Forschungsanst. Eberswalde eV D-16227 Eberswalde Germany). Majeed S. Y. Curlik J. Background levels of trace elements in the soils of Zitny Ostrov Slovakia. Geol. Carpathica-Clays 1993 2 107. (Fac. Sci. Comenius Univ. Bratislava 842 15 Slovakia). Chiang Y. H. Kim K. S. Yeob Y. S. Kang H. S. Cho I. H. Bae E. K. Influence of different UV dose on metatarsus mineral contents in broiler chicks.Hanguk Ch’uksan Hakhoechi 1994 36 154. (Coll. Agric. Kyungpook Natl. Univ. South Korea). Park W.-H. Studies on inorganic components of Korean wild edible mushrooms. Trace mineral ele- ments of Armillariella mellea Hygrophorus russula Armillariella tabescens Lepista nuda and Lepista sor- deda Hygrocybe conica. Hanguk Kyunhakhoechi 1993 21 273. (Dept. Environ. Eng. Seoul Natl. Polytech. Univ. Seoul 139-743 South Korea). McCarty J. D. Carter S. P. Fletcher M. J. Reape M. J. Study of lithium absorption by users of spas treated with lithium ion. Hum. Exp. Toxicol. 1994 13 315. (FMC Corp. Princeton NJ 08543 USA). de Sousa M. Reimao R. Lacerda R. Hugo P. Kaufmann S. H. E. Porto G. Iron overload in p2- microglobulin-deficient mice. Immunol. Lett.1994 39 105. (Mol. Pathol. Immunol. Salazar Inst. Biomed. Sci. Oporto 4000 Portugal). Hartounian H. Sandler S. I. Kaler E. W. Aqueous two-phase systems. 1. Salt partitioning. Ind. Eng. Chem. Res. 1994 33 2288. (Center Mol. and Eng. Thermodynamics Univ. Delaware Newark DE 19716 USA). Pelus E. Arnaud J. Ducros V. Faure H. Favier A. Roussel A. M. Trace element (Cu Zn Fey Mn Se) intakes of a group of French men using the duplicate diet technique. Int. J. Food Sci. Nutr. 1994 45 63. (Lab. Biochem. CHUG 38043 Grenoble France). Latorre M. J. Garcia-Jares C. Medina B. Herrero C. Pattern recognition analysis applied to classification of wines from Galicia (northwestern Spain) with certified brand of origin. J. Agric. Food Chem. 1994 42 1451. (Dept. Quim. Anal. Nutr. Bromatol.Fac. Ciencias Lugo Lug0 27002 Spain). Yang Q. Penninckx W. Smeyers-Verbeke J. Closed- vessel microwave acid digestion of foodstuffs and trace aluminium determination by graphite furnace atomic absorption spectrometry. J. Agric. Food Chem. 1994 42 1948. (Pharm. Inst. Vrije Univ. Brussels 1090 Brussels Belgium). Madigan D. McMurrough I. Smyth M. R. Determination of oxalate in beer and beer sediments using ion chromatography. J. Am. SOC. Brew. Chem. 1994,52 134. (Guiness Brewing Worldwide Res. Centre Dublin Ireland). (ICP-AES). GIT Fachz. Lab. 1994 38 778. (Abt. 9512727 9512728 9512729 9512730 9512731 9512732 9 512 73 3 9 512 7 3 4 9512735 9512736 951273 7 9512738 9 5/27 3 9 95/2740 Rodriguez T. Mineral losses in hot water- and micro- wave-blanched green and dry white beans.J. Agric. Univ. P. R. 1993 77 129. (Res. Assoc. Lab. Food Technol. Puerto Rico). Sawhney B. L. Nugbee G. J. Stilwell D. E. Leachability of heavy metals from growth media containing source-separated municipal solid waste com- post. J. Enuiron. Qual. 1994 23 718. (Dept. Soil and Water Connecticut Agric. Exp. Stn. New Haven CT 06504 USA). Francis D. R. Bennett K. A. Additional data on mercury accumulation in northern Michigan river otters. J. Freshwater Ecol. 1994 9 1. (Center Great Lakes Aquat. Sci. Univ. Michigan Ann Arbor MI Powell S. R. Wapnir R. A. Adventitious redox-active metals in Krebs-Henseleit buffer can contribute to Langendorff heart experimental results. J. Mol. Cell. Cardiol. 1994 26 769. (Dept. Surg. Pediatr. North Shore Univ. Hosp. Manhasset NY USA).Wilkinson R. E. Duncan R. R. Berry C. Verapamil influence on mineral nutrient content of sorghum root tips. J. Plant Nutr. 1994 17 1551. (Dept. Crop and Soil Sci. Griffin GA 30223-1797 USA). Sadiq M. Hussain G. Effect of chelate fertilizers on dry matter and metallic composition of bean plants in a pot experiment. J. Plant Nutr. 1994 17 1477. (Res. Inst. King Fahd Univ. Petroleum and Miner. Dhahran Saudi Arabia). Wilkinson R. E. Duncan R. R. Acid-soil stress influence on mineral-ion contents of sorghum leaves and juvenile panicles. J. Plant Nutr. 1994 17 1309. (Dept. Crop and Soil Sci. Univ. Georgia Griffin GA 30223 USA). Amorusi P. Lessard D. Bansal S. K. Selinger K. Yacobi A. Tonelli A. P. Analysis of enloplatin by liquid chromatography and of platinum by atomic absorption spectrometry in various biological fluids.J. Pharm. Biomed. Anal. 1994,12 1023. (Dept. Bioanal. Support American Cyanamid Co. Pearl River NY 10965 USA). Arnaud J. Prual A. Preziosi P. Favier A. Hercberg S. Selenium determination in human milk in Niger influence of maternal status. J. Trace Elem. Electrolytes Health Dis. 1993 7 199. (Cent. Hosp. Reg. Univ. Grenoble 38043 Grenoble 9 France). Tiran B. Tiran A. Rossipal E. Lorenz 0. Simple decomposition procedure for determination of selenium in whole blood serum and urine by hydride generation atomic absorption spectroscopy. J. Trace Elem. Electrolytes Health Dis. 1993 7 211. (Inst. Med. Biochem. Karl Franzens Univ. Graz A-8010 Harrachgasse Austria). Ogoshi K. Yanagi S. Moriyama T. Arachi H.Accumulation of aluminium in cancers of the liver stomach duodenum and mammary glands of rats. J. Trace Elem. Electrolytes Health Dis. 1994 8 27. (Dept. Public Health Nara Med. Univ. Kashihara 634 Japan). Lu X.- Wang J.-f. Xiao W.-b. Changes of Na+ K’ Gas" and Mg2+ in serum of aconitine-induced arrhythmic rats. Junshi Yixue Kexueyuan Yuankan 1994 18 102. (Inst. Pharmacol. Toxicol. Acad. Mil. Med. Sci. China). Ebato K. Nakamura H. Elements content in private human hair (zinc magnesium). Kenkyu Nenpo-Tokyo- toritsu Eisei Kenkyusho 1993 44 195. (Tokyo Metrop. Res. Lab. Public Health Tokyo 169 Japan). Boer P. Braam B. Fransen R. Boer W. H. Koomans H. A. Reliable atomic absorption analysis of sodium and potassium in rat renal tubular fluid. Kidney Int. 1994 45 1211.(Dept. Nephrol. and Hypertens. Univ. Hosp. Utrecht Utrecht Netherlands). 48 109-2099 USA). Journal of Analytical 4tomic Spectrometry August 1995 Vol. 10 245R9512741 9512742 9512743 9512744 9512745 9512746 9512747 9512748 9512749 9512750 9512751 9 5/27 52 9512753 9512 754 246 R Burguera M. Burguera J. L. Online automated determination of titanium dioxide in soaps by flow injection graphite furnace atomic absorption spectro- photometry. Lab. Rob. Autom. 1993 5 277. (Fac. Sci. Univ. Los Andes Merida 5101 Venezuela). Schwedt G. Petri J. Elimination of matrix effects by UV photolysis. LaborPraxis 1993 16 1223. (Inst. Anorg. Anal. Chem. Tech. Univ. Clausthal W-3392 Clausthal-Zellerfeld Germany). Rinkis G. Osvalde A. Ramane H. Kunicka T. Way of using the atomic absorption method in determining Pb Cd Co and Ni contents in biological samples.Latu. Zinat. Akad. Vestis By 1993 10 49. (Biol. Inst. LZA Salaspili LV-2169 Latvia). Winnefeld K. Klinger G. Dawczynski H. Treff E. Hein S. Antioxidant status of woman receiving contra- ceptives. Luboratoriumsmedizin 1993 17 577. (Klin. Chir. Friedrich-Schiller-Univ. D-07740 Jena Germany). Saito N. Kooishi Y. Abbu G. Alteration of erythrocyte magnesium by the increment of plasma aldosterone concentration in human subjects. Maguneshumu (Kyoto) 1993 12 155. (Dept. Geriatr. Kochi Med. Univ. Kochi 783 Japan). de Santa Maria L. C. Soga K. Shiono T. Polymerization of olefins with the TiC1,/Si02 catalyst system modified with MgC1,. Macromol. Chem. Phys. 1994,195,2591. (Inst. Ciencias Escola Fed.Engenharia 37500-000 Itajuba Brazil). O’Keefe M. J. Rigsbee J. M. Plasma polymerization of fluorocarbon thin films on glass and metal substrates. Muter. Res. SOC. Symp. Proc. 1993 304 179. (Solid State Electron. Dir. Wright-Patterson AFB OH Tasaka Y. Horasawa N. Takahashi S. Uematsu T. Hasegawa T. Biological evaluation of dental metals - toxic effect of metal cations. Matsumoto Shigaku 1994 20 64. (Dept. Dental Technol. Matsumoto Dental Coll. Japan). Hylland K. Kaland T. Andersen T. Subcellar Cd accumulation and Cd-binding proteins in the netted dog whelk Nassarius retisulatus L.. Mar. Enuiron. Res. 1994 38 169. (Dept. Biol. Univ. Oslo N-0316 Oslo Norway). Tomera J. F. Lilford K. Kukulka S. P. Friend K. D. Harakal C. Divalent cations in hypertension with implications to heart disease calcium cadmium inter- actions.Methods Find. Exp. Clin. Pharmacol. 1994 16 97. (Harv. Med. Sch. and Clin. Pharmacol. Lab. Mass. Gen. Hosp. and Shriners Burns Inst. Boston MA USA). Arefi F. Tatoulian M. Andre V. Amouroux J. Lorang G. Aluminium metallization of polypropylene films pretreated by a nitrogen or ammonia non- equilibrium plasma. Study of the interface and adhesion measurements. Met. Plast. 1992,3,243. (ENSCP Univ. Paris VI 75231 Paris France). Hashemi F. Leppard G. G. Kushner D. J. Copper resistance in Anabaena uariabilis effects of phosphate nutrition and polyphosphate bodies. Microb. Ecol. 1994 27 159. (Dept. Bot. Univ. Toronto Toronto Ontario Canada M5S 3B2). Chao C. C. K. Decreased accumulation as a mechanism of resistance to cis-diamminedichloroplatinum(r1) in cervix carcinoma HeLa cells relation to DNA repair.Mol. Pharmacol. 1994 45 1137. (Dept. Biochem. Chang Gung Med. Coll. Taoyuan 33332 Taiwan). Singh R. S. Singh R. P. Singh J. Singh R. P. Singh R. P. Status of heavy metals (Cd Pb and Cr) in milk of cow and buffalo exposed to polluted environment. Modell. Meas. Control C 1992 33(3) 43. (Cent. Res. Lab. Udai Pratap Auton. Coll. Varanasi India). 45433-6543 USA). 95/27 5 5 9512756 9 5/27 5 7 9 5/27 5 8 9512759 9512760 9512761 9512762 9512763 9512764 9512765 9512766 9512767 9512768 9512769 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 Singh R. S. Singh R. P. Influence of polluted aquatic environment on content of Cd Pb and Cr of buffalo milk. Modell. Meas. Control C 1993 36(1) 51.(Cent. Res. Lab. Udai Pratap Auton. Coll. Varanasi India). Nakajima H. Yagihashi O. Kashima Y. Ishikawa H. Kitano S. Kimoto I. Tomioka E. Mano M. Takeuchi S. Effects of ascorbic acid on trace element metabolism in the choroid-retina of streptozotocin- induced diabetic guinea pigs. Nippon Ganka Gakkai Zasshi 1993 97 340. (Sch. Med. Nihon Univ. Japan). Singh A. K. Liu H. Y. Lee S. T. Atomic absorption spectrophotometric measurement of intracellular arsen- ite in arsenite-resistant Leishmania. Mol. Biochem. Parasitol. 1994,66 161. (Div. Infect. Dis. Inst. Biomed. Sci. Acad. Sin. Taipei 11 529 Taiwan). Syed A. M. Qadiruddin M. Detection and estimation of essential trace elements in tea (Thea sinensis) by ICP-AES and FAAS methods. Pak. J. Sci. Ind.Res. 1993 36 325. (PCSIR Lab. Complex Karachi 75280 Pakistan). Adeyeye E. I. Trace heavy metal distribution in the fish Ilisha africana organs and tissue. 11. Chromium zinc copper iron and cobalt. Pak. J. Sci. Ind. Res. 1993,36 333. (Dept. Chem. Fed. Univ. Technol. Akure P.M.B. 704 Nigeria). Pal S. Misra S. K. Organotin copolymers for self polishing antifouling paints (SPCs). Paintindia 1993 43(10) 19. (Res. Dev. Lab. Shalimar Paints Ltd. Howrah India). Chen T.-B. Application of NaHC0,DTPA extractant-ICP spectrometry technique in soil test for availability of nutrients and heavy metals. Pedosphere 1993 3 377. (Inst. Geogr. Acad. Sci. Beijing 100101 China). Colak N. Gumgum B. Determination of iron by ICP- AES in stereoregular poly (propylene oxide) prepared by Pruitt-Baggett catalyst.Polym. Plast. Technol. Eng. 1994 33 105. (Fac. Arts Sci. Univ. Dicle Diyarbakir 21280 Turkey). Mehta B. H. Bachewar M. S. Effect of polluted water on chemical constituents of Colocasia esculenta. Pollut. Res. 1994 13 11. (Dept. Chem. Univ. Bombay Vidyanagri Bombay 400 098 India). Jedrzejczak R. Szteke B. Arsenic and heavy metals levels in preserved vegetable and vegetable-meat food produced in Poland. Pol. J. Food Nutr. Sci. 1993 2(3) 33. (Dept. Food Anal. Inst. Biotechnol. the Agric. and Food Ind. 02-532 Warsaw Poland). Ladyzhenskaya E. P. Frolova I. K. Effect of abscisic acid on the calcium content in the microsomal fraction of potato tuber cells. Prikl. Biokhim. Mikrobiol. 1994 30 279. (Bach Inst. Biochem. Moscow Russia). Winkler W. Buhl F.Use of XRFS AAS and polargraphic methods for determination of trace non- ionic surfactants. Przem. Chem. 1994 73 182. (Inst. Chem. Univ. Slaskiego Katowice Poland). Schechter I. Wisbrun R. Niessner R. Schroder H. Kompa K. L. Real time detection of hazardous elements in sand and soils. Proc. SPIE-Int. SOC. Opt. Eng. 1994 2092 174. (Inst. Hydrochem. Tech. Univ. Munich D-81377 Munich Germany). Lima N. Benedito S. Bezerra C. W. B. Polastro L. R. Campos P. Nascimento R. F. Furuya S. M. B. Franco D. W. Copper in Brazilian sugarcane spirits quantitation and control. Quim. Nova 1994 17 220. (Inst. Fis. Quim. Sao Carlos USP 13560-970 San Carlos Brazil). Perez P. J. M. Sanz-Medel A. Cobalt determination in serum of patients with chronic renal failure by ETAAS using palladium as matrix modifier.Quim. Anal. (Barcelona) 1993 12 30. (Dept. Phys. Anal. Chem. Univ. Oviedo Oviedo 33006 Spain).9512770 9512771 9512772 95/2773 9512774 9512775 9512776 9 5/27 77 9512778 9512779 9512780 951278 1 9512782 9512783 Carbonell G. Ramos C. Tarazona J. V. Copper distribution in different protein fractions in rainbow trout experimentally poisoned with copper sulfate Rev. Toxicol. 1994 11 23. (CISA INIA Valdeolmos 28130 Spain). Javier F. Lopez G.-E. Internal quality control in the analysis of lead in blood by graphite furnace atomic absorption spectrometry. Reu. Toxicol. 1993 10 133. (Cent. Nac. Nuevas Tecnol. Inst. Nac. Segur. Hig. Trab. Madrid 28027 Spain). Battista T. Di. Cichelli A. Solinas M. Angerosa F. Multivariate statistical analysis for the determination of metals in virgin olive oils obtained by different extraction systems.Riu. ltal. Sostanze Grasse 1993 70 541. (Dip. METODI Quant. Univ. G DAnnunzio Pescara Italy). Huang S.-m. He B.4. One-step preparation of poly- mer-supported colloidal palladium catalysts and their catalytic properties. I. Synthesis and characterization. React. Polym. 1994 23 1. (Inst. Polymer Chem. Nankai Univ. Tianjin 300071 China). Donoghue D. J. Hairston H. Bartholomew M. J. Wagner D. D. Arsenic residues in chicken eggs from laying hens administered feed containing arsanilic acid and roxarsone. Residues Vet. Drugs Food Proc. EuroResidue Conf. 2nd 1993 1 276. (Div. Anim. Res. Cent. Vet. Med. Food and Drug Admin. Beltsville MD 20705 USA). Shelley B. Determination of cadmium microadditives in food products.Prakt. SertiJ 1992 14102. (Russia). Hosoda K. Omae K. Onodera M. Oda K. Sakurai H. Comparison of matrix modifiers for simple determi- nation of cadmium in blood and urine by graphite furnace atomic absorption spectrophotometry. Sangyo Igaku 1994 36 102. (Sch. Med. Keio Univ. Tokyo 160 Japan). Cabrera C. Ortega E. Gallego C. Lopez M. C. Lorenzo M. L. Aseosio C. Cadmium concentration in farmlands in southern Spain possible sources of contamination. Sci. Total Enuiron. 1994 153 261. (Dept. Nutr. Bromatol. Granada E-18014 Spain). Bordin G. McCourt J. Rodriguez A. Trace metals in the marine bivalve Macoma balthica in the Westerschelde estuary The Netherlands. Part 2 Intracellular partitioning of copper cadmium zinc and iron-variations of the cytoplasmic metal concen- trations in natural and in in uitro contaminated clams.Sci. Total Enuiron. 1994 151 113. (Comm. Eur. Commun. Joint Res. Centre I.R.M.M. Steenweg op Retie 2440 Geel Belgium). Kniewald G. Kozar S. Brajkovic D. Bagi C. Branica M. Trace metal levels in fossil human bone from the Bezdanjaca necropolis in Croatia. Sci. Total Enuiron. 1994 151 71. (Center for Mar. Res. Rudjer Boskovic Inst. Univ. Zagreb POB 1016 Zagreb 41001 Croatia). Zhang Z.q. Xi Y.-y. Han X.-h. Li Y.-b. Study of trace element content in a magistral and its six Chinese crude drugs and their efficacy. Shanxi Daxue Xuebao Ziran Kexueban 1994 17 228. (Hospital Shanxi Univ. Taiyuan China). Fang J.-h. Yu M.-h. Yang X.-f. Zhu X.-x. Determination of serum trace chromium with graphite atomic absorption spectroscopy.Shanghai Yike Daxue Xuebao 1994 21( l) 51. (Huashan Hosp. Shanghai Med. Univ. Shanghai China). Yasumoto M. Imai Y. Iwami O. Watanabe T. Ikeda M. Shimbo S. Dietary intake of cadmium and lead. Part 1. Determination of cadmium and lead in diet by atomic absorption spectrometry. Kyoto Joshi Daigaku Shokurnotsu Gakkaishi 1993 48 1. (Kyoto Women’s Univ. Tokyo Japan). Ikebe K. Nishimune T. Sueki K. Behaviour of several elements in foods. VII. Contents of 17 metal elements 9 512 7 8 4 9512785 9 5/27 8 6 9512787 9512788 95/2789 9512790 951279 1 9512792 9512793 9512794 9512795 9512796 9512797 in food determined by inductively coupled plasma atomic emission spectrometry. Meat and meat products. Shokuhin Eiseigaku Zasshi 1994 35 323.(Osaka Prefect. Inst. Public Health Osaka 537 Japan). Khairallah Y. Khonsari-Arefi F. Amouroux J. Decomposition of gaseous dielectrics (CF SF,) by a non-equilibrium plasma. Mechanisms kinetics mass spectrometric studies and interactions with polymeric targets. Pure Appl. Chem. 1994 66 1353. (Lab. Reacteurs Chim. en Phase Plasma Univ. Paris VI 7523 1 Paris France). Schrier L. C. Manahan S. E. Overview of xenobiotic analysis. Determination of Cd Hg and Pb in human matrixes by atomic absorption spectroscopy. Spectroscopy (Eugene Oreg.) 1994 9( 2) 24. (ABC Instrum. Columbia MO 65202 USA). Yasumoto M. Imai Y. Kawamura S. Kimura K. Yamamoto K. Iwami O. Watanabe T. Ikeda M. Shimbo S. Dietary intake of cadmium and lead. Part 2. Dietary intake of cadmium and lead among Japanese population.Kyoto Joshi Daigaku Shokumotsu Gakkaishi 1993 48 8. (Kyoto Women’s Univ. Kyoto Japan). Xing B. Dudas M. J. Division S-9-soil mineralogy. Characterization of clay minerals in white clay soils. People’s Republic of China. Soil Sci. SOC. Am. J. 1995 58 1253. (Dept. Soil Sci. Univ. Alberta Edmonton Alberta Canada T6G 2E3). Su Y.d. Zhao W.-m. Gu Z.-c. Indirect determination of the pesticide malathion by atomic absorption spectrophotometry. Tongji Dame Xuebao Ziran Kuxueban 1994 22 127. (Dept. Chem. Tongji Univ. Shanghai 200092 China). Bassari A. Study of the trace element concentrations of Thunnus thynnus Thunnun obesus and Katsuwonus pelamis by means of ICP-AES. Toxicol. Enuiron. Chem. 1994 44 123. (Cekmece Nucl. Res. Cent. Istanbul Turkey).Egemen A Tatar N. Blood cadmium levels in smokers and non-smokers. Turk. J. Med. Sci. 1993 17 227. (Fac. Med. Hacettepe Univ. Ankara Turkey). Cai X.-n. Shen G.-p. Use of flame atomic absorption spectroscopic method for determination of cadmium content in rubber products. Xiangjiao Gongye 1993 40 291. (Shanghai Inst. Nucl. Res. Shanghai 201800 China). Oh S. J. Oh Y. T. Yoon W. Y. Park S. B. Determination of selenium in dried yeast preparations. Yakche Hakhoechi 1994,24( l) 29. (Seoul Metrop. Gov. Inst. Health and Environ. South Korea). Boppel B. Diehl J. F. Arsenic lead and cadmium in home-made preserves of fruits and vegetables from former decades. Part 1. Cherries since the 1911 harvest year. 2. Lebensm. Unters. Forsch. 1993 197 570. (Inst. Ernaehrungsphysiol.Bundesforschungsanst. Ernaehr. D-76131 Karlsruhe Germany). Petrovic Trstenjak Z. Mandic M. L. Grgic J. Grgic Z. Ash and chromium levels of honey. 2. Lebensm. Unters. Forsch. 1994 198 36. (Fac. Food Technol Osijek HR-54000 Croatia). Hajslova J. Holadova K. Kocourek V. Poustka J. Cuhra P. Raverdino V. Determination of PCBs in fatty tissues by several detection techniques. 2. Lebensm. Unters. Forsch. 1993 197 262. (Dept. Food Chem. Anal. Univ. Chem. Technol. Prague 16628 Czech Republic). Shi MA. Lu G.-w. Li L. Ar Y.-y. Zeng A.-h. Nan H. Changes of essential trace elements contents in mouse brain tissue following acute and repeated exposure to hypoxia. Zhonggue Bingli Shengli Zazhi 1993 9 426. (Dept. Neurobiol. Capital Inst. Med. Beijing 100054 China). Zhang X.-g.Wu Y.-p. Cbai Y. Assay of carboplatin in human plasma by atomic absorption spectrometry. Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 247 R9512798 9512799 9512800 95/2801 9512802 9512803 9512804 9512805 9512806 9512807 9512808 Zhongguo Yaoxue Zazhi 1994 29 111. (Dept. Pharm. China-Japan Fri'endship Hosp. Beijing 100029 China). Cheng P. L. Wang H. Guoo S. Zinc status in uremic patients with or without hemodialysis. Zhonghua Minguo Yingyang Xuehui Zazhi 1994 19 151. (Nutr. Dept. Tri-Serv. Mil Hosp. Taipei Taiwan). Abdullin I. F. Budnikov G. K. Badretdinova G. Z. Coulometric preparation of reference solutions of metals in organic solvents for atomic absorption analysis of petroleums and petroleum products. Zh. Anal. Khim. 1994 49 639. (Ul'yanov-Lenin Kazan State Univ.Tatarstan 420008 Russia). Bacic G. Ratkovic S. Atomic absorption spectroscopy and proton NMR study of manganese efflux from maize roots. Zb. Matice Srp. Prir. Nauke 1993 84 35. (Fac. Sci. Univ. Belgrade 11010 Belgrade Yugoslavia). Farmer J. G. Sugden C. L. MacKenzie A. B. Moody G. H. Fulton M. Isotopic ratios of lead in human teeth and sources of exposure in Edinburgh. Enuiron. Technol. 1994,15,593. (Dept. Chem. Univ. Edinburgh West Mains Rd. Edinburgh UK EH9 355). Taylor A. Briggs R. J. Cevik C. Findings of an external quality assessment scheme for determining aluminium in dialysis fluids and water. Clin. Chem. ( Winston-Salem N. C . ) 1994,40,1517. (Trace Elements Lab. Robens Inst. Health and Safety Univ. Surrey Guildford UK GU2 5XH).Powell S. R. Hall D. Autio L. Wapnir R. A. Teichberg S. Tortolani A. J. Zinc improves postisch- emic recovery of isolated rat hearts through inhbition of oxidative stress. Am. J. Physiol. 1994 266 H2497. (Dept. Surg. North Shore Univ. Hospital Manhasset NY 11030 USA). Standards Australia Methods for the analysis of iron and steel. Part 38 Determination of vanadium con- tent - flame atomic absorption spectrometric method. Australian Standard AS/NZS 1050.38:1994 [IS0 9647:1989] 1994 pp. 16. (1 The Crescent Homebush NSW 2140 Australia). Standards Australia Analysis of urine for trace elements. Part 2 Determination of copper cadmium and lead - flame atomic absorption spectrometric method. Australian Standard AS 4205.2 - 1994 1994 pp. 16. (1 The Crescent Homebush NSW 2140 Australia).Standards Australia Methods for the analysis of iron and steel. Part 39 Determination of chromium con- tent - flame atomic absorption spectrometric method. Australian Standard AS/NZS 1050.39 1994 [ I S 0 10138:1991] 1994 p. 20. (1 The Crescent Homebush NSW 2140 Australia). Standards Australia Methods for the analysis of iron and steel. Part 20 Determination of magnesium content - flame atomic absorption spectrometric method. Australian Standard AS/NZS 1050.20 1994 1994 pp. 12. (1 The Crescent Homebush NSW 2140 Australia). British Standards Institution Sampling and analysis of nickel ferronickel and nickel alloys. Part 15 Method for the determination of titanium in nickel alloys by 9512812 9512813 95/28 14 9512815 9512816 9512817 9512818 95/28 19 9 512 8 20 9512821 9512822 in blood.Anal. Lett. 1994 27 2647. (Inst. Chem. Univ. Warsaw Branch Bialystok Bialystok Poland). Patwardhan A. B. Kulkarni V. T. Radhakrishnan K. Ramanujam A. Page A. G. Determination of uranium-233 by inductively coupled argon plasma atomic emission spectrometry. Anal. Lett. 1994 27 2377. (Fuel Reprocessing Div. Bhabha Atomic Res. Centre Bombay 400 085 India). Jansen E. Lighting a torch for the oil in your engine. Analysis Europa 1994 23. (Kuwait Petroleum Res. and Technol. Netherlands). Gulmini M. Ostacoli G. Zelano V. Torazzo A. Comparison between microwave and conventional heating procedures in Tessier's extractions of calcium copper iron and manganese in a lagoon sediment. Analyst (London) 1994 119 2075. (Dipt. Chim. Anal. Univ. Torino 10125 Turin Italy).Grazia del Monte Tamba M. Falciani R. Dorado Lopez T. Gomez Coedo A. One-step microwave digestion procedures for the determination of alu- minium in steels and iron ores by inductively coupled plasma atomic emission spectrometry. Analyst (London) 1994 119 208 1. (Centro Sviluppo Materiali Rome Italy). Gray A. L. Plasma source for mass analysis. Anal. Proc. (London) 1994 31 369. (Applied Res. Lab. Ltd. Luton Beds. UK LU4 8PU). Poupon J. Chappuis P. Rousselet F. Deraed C. Determination of aluminium in biological media by a simple method using inductively coupled plasma emis- sion spectrometry. Analusis 1994,22,360. (Lab. Central Biochim. Hopital Lariboisiere 75010 Paris France). Livardjani F. Heimburger R. Lugnier A. A Jaeger A. Determination of mercury in urine by cold vapour atomic absorption spectrometry.Analusis 1994 22 365. (Centre Anti-Poisons Pavillon Pasteur CHU 67000 Strasbourg France). Bolshov M. A. Boutron C. F. Determination of heavy metals in polar snow and ice by laser-excited atomic fluorescence spectrometry. Analusis 1994 22 M44. (Lab. Glaciol. Geophys. Environ. CNRS 38402 Saint- Martin-&Heres France). Harnly J. M. Evaluation of calibration methods for Zeeman graphite furnace atomic absorption spec- trometry using computer modelling. Appl. Spectrosc. 1994 48 1156. (ARS USDA Beltsville Human Nutr. Res. Centre Beltsville MA 20705 USA). Luo F.-g. Hou X.d. Determination of sub-ppb levels of thallium in natural water by STPF AAS after preconcentration using polyurethane plastic foam column.At. Spectrosc. 1994 15 216. (Chengdu Rock and Mineral Testing Central Lab. Min. Geol. and Mineral Resources Chengdu Sichuan 610081 China). Liu X.-z. Xu S.-k. Fang Z.4. Determination of trace amounts of lead in biological materials by flow-injection hydride-generation AAS with sensitivity enhancements using nitroso-R salt. At. Spectrosc. 1994 15,229. (Flow Injection Anal. Res. Centre Inst. Appl. Ecol. Shenyang 110015 China). diantipyrylmethane molecular absorption spectrometry. British Standard BS 6783:Part 15:1994[Iso 9512823 Piso S. de Boer J. L. M. A priori calculation of 11433:1993] 1994 pp. 12. (Linford Wood Milton instrumental detection limits in graphite-furnace atomic absorption spectrometry. At. Spectrosc. 1994 15 220. (RIVM 3720 BA Bilthoven Netherlands).Keynes UK MK14 6LE). Lachance G. Claisse F. Quantitative X-ray fluores- Ostronova M. M. Methods for the analysis of sorbent concentrate in graphite furnace AAS. At. Spectrosc. and Sons Ltd. Chichester W. Sussex UK 1994. 0 471 1994. 15. 245. (Vernadskii Inst. Geochem. and Anal. 95167 6 pp. 428. 9512809 cence analysis. Theory and applications. John Wiley 95/28" Sedykh E* Ma Tatsy YU. G-9 Ishmiyarova G. R.9 9512810 Wilson R. H. Spectroscopic techniques for food analysis. VCH Publishers Inc. New York NY USA 1994. 1 56081 037 8. 256. Ward N. I. Determination of trace amounts of cobalt Chem. 1'17334 Moscow Russia). Iyer C. S. P. Rao T. P. Kartikeyan T. Damodaran A. D. Determination of ultra-trace levels of molyb- 95/2811 Godlewska B. Hulanicki A. Abou-Shakra F.R. denum in sea water using flow-injection online precon- centration and flame AAS. At. Spectrosc. 1994 15 234. 9512825 248R Journal of Analytical Atomic Spectrometry August 1995 Vol. 109 512 8 26 9512827 9512828 9512829 9512830 9512831 9512832 9 5/28 3 3 9512834 9 51283 5 9512836 9512837 9512838 9512839 9512840 (Centre Mar. Anal. Ref. and Stand. Reg. Res. Lab. Trivandrum 695 019 India). Aceto M. Abollino O. Sarzanini C. Mentasti E. Mariconti F. Determination of aluminium in highly saline samples by electrothermal AAS after matrix removal. At. Spectrosc. 1994 15 237. (Dept. Anal. Chem. Univ. Turin 10125 Turin Italy). Bhattacharyya S. S. Electrothermal AAS determination of silver in coal fly ash. At. Spectrosc. 1994 15 242. (Dept. Chem. Univ. Burdwan Burdwan 713 104 India).Chernyakhovskiy V. Chernyakhovskaya S. Cirillo A. Fast graphite furnace technique with microwave sample preparation for lead determination in dust wipe and air filter samples. At. Spectrosc. 1994 15 250. (Adv. Environ. Control Staten Island NY 103 12 USA). Nolte J. ICP-OES analysis of waste waters and sludges. At. Spectrosc. 1994 15 223. (Bodenseewerk Perkin- Elmer GmbH 88647 Uberlingen Germany). Zehr B. D. Determination of boron chromium iron and silicon in nickel alloy. At. Spectrosc. 1994 15 213. (Guthrie Foundation Sayre PA 18840 USA). Sako N. Tanake H. Toyoda M. Naka J. Kuramoto K. Determination of trace metals on a silicon wafer by acid dissolution and graphite furnace AAS. Bunseki Kagaku 1994 43 771. (Dev. Centre Mitsubishi Kasei Corp.Kurosaki Kitakyushu Fukuoka 806 Japan). Hirano Y. Yasuda K. Hirokawa K. Unexpected increases of atomic vapour temperature in graphite furnace AAS. Bunseki Kagaku 1994,43,813. (Instrum. Div. Hitachi Ltd. Katsuta Ibaraki 312 Japan). Watanabe K. Demura K. Fluorimetric determination of copper(I1) by its catalysis of the oxidation of 1,lO-phenanthroline with hydrogen peroxide. Bunseki E(Bgd4 1994 43 809 ( F a S c i and Teshnd ScL Univ. Tokyo Noda Chiba 278 Japan). Yu H.-f. Wang A,-x. Xu S.-s. Yang G.-q. Determination of copper cobalt and nickel in alkali salts by liquid membrane enrichment - flame atomic absorption spectrophotometry. Fenxi Huaxue 1994,22 973. (Dept. Chem. Changchun Normal Coll. Changchun 130032 China). Du N.-I. Wang G.4 Li Y. Atomic absorption spectrophotometric determination of micro-amounts of antimony using trioctylmethylammonium chloride as the extracting agent.Fenxi Huaxue 1994 22 945. (Dept. Chem. Heilongjiang Univ. Harbin 150080 China). Jia C.-g. Dai S.-g. Ma J.-q. Gao X. Transient signal collecting and processing software for the coupling of HPLC with ICP-AES and its applications. Fenxi Huaxue 1994 22 865. (Dept. Environ. Sci. Nankai Univ. Tianjin 300071 China). Wei Q. Du B. Du Z.-h. Determination of ferrocene in gasoline by micro-emulsion sampling - flame atomic absorption spectrometry. Fenxi Huaxue 1994 22 971. (Dept. Appl. Chem. Shandong Inst. Building Materials Jinan 250022 China). Beinrohr E. Csemi P. Manova A. Daurov J. Absolute analysis of trace metals through galvanostatic stripping chronopotentiometry with signal accumu- lation.Fresenius’ J. Anal. Chem. 1994 349 625. (Dept. Anal. Chem. Slovak Tech. Univ. 812 37 Bratislava Slovakia). Hofmann C. Pauwels J. Vandecasteele C. Use of solid sampling Zeeman atomic absorption spectrometry (SS-ZAAS) for certification purposes. Fresenius ’ J. Anal. Chem. 1994 349 779. (Joint Res. Centre Inst. Ref. Mater. and Measure. Comm. Eur. Commun. 2440 Geel Belgium). Bombach G. Bombach K. Klemm W. Speciation of mercury in soils and sediments by thermal evaporation 9512841 9512842 9512843 9512844 9512845 9512846 9512847 9512848 95 f2849 9512850 9512851 9512852 and cold vapour atomic absorption. Fresenius’ J. Anal. Chem. 1994 350 18. (Inst. Miner. Geochem. and Ore Deposits Freiburg Univ. Mining and Technol. 09596 Freiberg Germany).Stein K. Schwedt G. Speciation of chromium in the waste water from a tannery. Fresenius’ J. Anal. Chem. 1994 350 38. (Inst. Anorg. and Anal. Chem. Tech. Univ. Clausthal 38670 Clausthal-Zellerfeld Germany). Ruede T. R. Puchelt H. Development of an automated technique for the speciation of arsenic using flow- injection hydride-generation atomic absorption spec- trometry (FI-HG-AAS). Fresenius’ J . Anal. Chem. 1994 350 44. (Inst. Petrogr. and Geochem. Karlsruhe Univ. 76128 Karlsruhe Germany). Bombach G. Pierra A Klemm W. Arsenic in contaminated soil and river sediment. Fresenius’ J. Anal. Chem. 1994 350 49. (Inst. Miner. Geochem. and Ore Deposits Freiberg Univ. Mining and Technol. 09596 Freiberg Germany). Ballin U. Kruse R. Ruessel H.-A. Determination of total arsenic and speciation of arseno-betaine in marine fish by means of reaction - headspace gas chromatog- raphy utilizing flame-ionization detection and element specific spectrometric detection.Fresenius’ J. Anal. Chem. 1994 350 54. (Stattliches Vet. Fische und Fischwaren 27472 Cuxhaven Germany). Cornejo N. Afailal A. Garcia F. Palacios M. Determination of zinc in ammoniacal ore leaching solutions by X-ray fluorescence spectrometry using a radioactive source. Fresenius ’ J. Anal. Chem. 1994,350 122. (Centro Nac. Invest. Metal. CENIM 28040 Madrid Spain). Lieser K. H. Flakowski M. Hoffmann P. Determination of trace elements in small water samples by totd r&wtion X-ray fluoresmb~(TXRF) and by neutron activation analysis (NAA). Fresenius’ J. Anal. Chem. 1994 350 135. (Fachbereich Chem.Eduard Zintl. Inst. Tech. Hochsch. 64289 Darmstadt Germany). Szmyd E. Baranowska I. Elimination of interferences from copper lead silver gold platinum palladium and selenium in the determination of mercury by CVAAS using sodium tetrahydroborate(rn) reduction in copper concentrates. Fresenius’ J. Anal. Chem. 1994 350 178. (Inst. Non-Ferrous Metals Dept. Anal. and Gen. Chem. Silesian Tech. Univ. 44-101 Gliwice Poland). Bruno P. Caselli M. Curri M. L. Favia P. Lamendola R. Mangone A. Traini A Laganara C. XPS ICP and DPASV analysis of mediaeval pottery - statistical multivariate treatment of data. Fresenius’ J. Anal. Chem. 1994,350 168. (Dipt. Chim. Univ. Bari 70126 Bari Italy). Bautista M. A. Perez Sirvent C. Lopez Garcia I. Hernandez Cordoba M.Flow-injection flame atomic absorption spectrometry for slurry atomization deter- mination of manganese lead zinc calcium magnesium iron sodium and potassium in cements. Fresenius’ J. Anal. Chem. 1994 350 359. (Dept. Agric. Chem. Fac. Chem. Univ. Murcia 30071 Murcia Spain). Danzer K. Venth K. Multisignal calibration in spark- and ICP-OES. Fresenius ’ J. Anal. Chem. 1994 350 339. (Chem. and Geosci. Fac. Dept. Inorg. and Anal. Chem. Friedrich Schiller Univ. 07743 Jena Germany). Delgado-Morales W. Mohan M. S. Zingaro R. A. Analysis and removal of arsenic from natural gas using potassium peroxydisulfate and polysulfide adsorbents. Int. J. Enoiron. Anal. Chem. 1994 54 203. (Dept. Chem. Texas A & M Univ. College Station TX Harrison W. W. Glow discharge - from a distance.ICP Inf. Newsl. 1994 20 495. (Dept. Chem. Univ. Florida Gainesville FL 3261 1 USA). 77843-3255 USA). Journal of Analytical ’ 4tomic Spectrometry August 1995 Vol. 10 249 R9512853 9512854 95/28 55 9 5/28 5 6 9512857 9512858 9 5/28 59 9512860 9512861 9512862 9 5/28 6 3 9512864 9512865 9512866 9512867 95/2868 250 R Marcus R. K. Glow discharge spectroscopies - a ten- year retrospective. ICP Inf. Newsl. 1994,20,496. (Dept. Chem. Clemson Univ. SC 29634-1905 USA). Gine M. F. Reis B. F. Krug F. J. Jacintho A. O. Bergamin H. Zagatto E. A. G. Flow-injection plasma spectrometry. ICP Inf. Newsl. 1994 20 413. (Centro Energia Nucl. Agric. Univ. Sao Paulo 13400-970 Piracicaba Sao Paulo Brazil). Al-Ammar A. Improved internal reference method for inductively coupled plasma atomic emission spec- trometry.ICP Inf. Newsl. 1994 20 335. (Chem. Dept. Baghdad Univ. Baghdad Iraq). Shaw P. Is inductively coupled plasma mass spec- trometry a specialist tool? Int. Labmate 1994 19 25. (ICP-MS Prod. Varian Optical Spectroscopy Instruments Warrington UK). Ombata J. M. Barry E. F. Determination of (methyl- cyclopentadieny1)manganesetricarbonyl in gasoline by capillary gas chromatography with alternating current plasma-emission detection. J. Chromatogr. A 1994 678 319. (Dept. Chem. Univ. Massachusetts Lowell Lowell MA 01854 USA). Grahek Z. Eskinja I. Cerjan S. Kvastek K. Lulic S. Separation of strontium from calcium by means of anion exchanger and alcoholic solution of nitric acid. J. Radioanal. Nucl. Chem. 1994 182 401. (Rudjer Boskovic Inst.Zagreb Croatia). Miller-Ihli N. J. Graphite furnace atomic absorption method for the determination of lead in sugars and syrups. J. AOAC Int. 1994 77 1288. (US Dept. Agric. Nutrient Composition Lab. BHNRC Beltsville MD 20705 USA). Yee H. Y. Nelson J. D. Jackson B. Measurement of lead in blood by graphite furnace atomic absorption spectrometry. J. Anal. Toxicol. 1994 18 415. (Detroit Med. Center Univ. Lab. Detroit MI 48201 USA). Wang G.-m. Chen B. Indirect determination of iodide by flame atomic absorption spectrometry based on neocuproine/copper(II)/iodide reaction. Lihua Jianyan Huaxue Fence 1994,30,270. (Centre Chem. Anal. East China Inst. Metallurgy Ma’anshan 243002 China). Huang G.q. Qian S.-h. Liu C.-w. Atom-trapping AAS determination of silver. Lihua Jianyan Huaxue Fence 1994,30,278.(Dept. Environ. Sci. Wuhan Univ. Wuhan 430072 China). Wu S.-p. Chen C.-j. Headspace hydride-generation flame AAS determination of antimony in copper concentrates. Lihua Jianyan Huaxue Fence 1994 30 268. (Anhui Import and Export Commodity Inspection Bureau Hefei 230061 China). Xu B. Mai A,-q. Spectrophotometric determination of zinc in copper ores and copper metals. Lihua Jianyan Huaxue Fence 1994,30,235. (Hubei Teachers’ Coll. Huangshi 435002 China). Yang J.4. Atomic absorption spectrophotometric deter- mination of trace bismuth in nickel-base alloys. Lihua Jianyan Huaxue Fence 1994 30 242. (Centre Chem. Lab. Baoding Chem. Fibre Plant Hebei 071055 China). Cai Y.-Q. Ni Q.-f. Flame emission determination of high contents of barium in aluminium-silicon-bariu- m-iron alloys.Lihua Jianyan Huaxue Fence 1994 30 227. (Shanghai Electric Bulb Factory Shanghai 200042 China). Liu S.-p. Atomic absorption spectrophotometric deter- mination of tin in tungsten ores. Lihua Jianyan Huaxue Fence 1994,30,241. (Chem. Lab. Guangdong Ore-Washing Plant Shaoguan 512026 China). Luo H.-q Liu S.-p. Status of the spectrophotometry and atomic absorption spectrophotometry of thallium. Lihua Jianyan Huaxue Fence 1994 30 244. (Dept. Chem. Southwest Teachers’ Univ. Chongqing 630715 China). 9512869 9512870 9512871 9 512 8 72 9512873 9512874 9512875 9512876 9 512 8 77 9512878 9512879 9512880 9512881 9512882 9512883 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 Gegus E. Optical atomic spectrometric methods of analysis.Magy. Kern. Foly. 1994 100 327. (MTA Veszpremi Anal. Kem. Tanszeki Kutatocsoportja 8201 Veszprem Hungary). Pesklak W. C. Piepmeier E. H. Laser-induced non- resonance atomic fluorescence in an analytical laser micro-probe plume. Microchem. J. 1994,50,253. (Dept. Chem. Oregon State Univ. Corvallis OR 97331 USA). Burakov V. S. Isaevich A. V. Misakov P. Ya. Raikov S. N. Intracavity laser spectrometer with electrothermal sample atomization for trace elements analyses. Microchem. J. 1994 50 365. (Inst. Mol. and At. Phys. Acad. Sci. Belarus Minsk 220072 Belarus). Radziemski L. J. Review of selected analytical appli- cations of laser plasmas and laser ablation 1987-1994. Microchem. J. 1994 50 218. (Phys. Dept. Washington State Univ. Pullman WA 99164-2814 USA).Thiem T. L. Wolf P. J. Analysis of National Institute of Standards and Technology ore and United States Geological Survey samples by inductively coupled plasma spectroscopyflaser-induced breakdown spec- troscopy. Microchem. J. 1994 50 244. (Dept. Chem. US Air Force Acad. Colorado Springs CO 80840 USA). Nekab M. Heitz C. Lagarde G. Amokrane A. Comparative methods for determination of rare earths in geological and mineral samples. J. Radioanal. Nucl. Chem. 1994 182 247. (Univ. Sci. Technol. Houari Boumelene El-Alia Algeria). Ebel H. Mantler M. Svagera R. Kaitna R. Investigation of thin films by soft X-ray fluorescence and by total-electron-yield measurements. Surf. Interface Anal. 1994 22 602. (Inst. Angew. Tech. Phys. Tech. Univ. Wien 1040 Wien Austria). Feng Y.Barratt R. S. Lead and cadmium composition in indoor dust. Sci. Total Enuiron. 1994 152 261. (Environ. Eng. Subject Group Fac. Technol. Open Univ. Milton Keynes UK MK7 6AA). Mauchien P. Andre N. Chaleard C. Geertsen C. Lacour J. L. Coupled laser ablation atomic spec- trometry for the elemental analysis of solids. Spectra 2000 [Deux Mille] 1994 180 33. (Lab. Spectrosc. Laser Anal. Centre Etudes Saclay 91 191 Gif-sur- Yvette France). Tatro M. E. Camp L. C. Christenberry R. K. Analysis of arsenic lead selenium and thallium in solid waste using a simultaneous trace analyser ICP. Spectroscopy (Eugene Oreg.) 1994 9(7) 36. (Spectra Inc. McAfee NJ 07428 USA). Blades M. W. Weir D. G. Fundamental studies of the inductively coupled plasma. Spectroscopy (Eugene Oreg.) 1994 9(8) 14. (Dept.Chem. Univ. British Columbia British Columbia Canada). Ball D. W. Spectroscopist’s tools. I. Absorption and emission spectrometers. Spectroscopy (Eugene Oreg.) 1994 9(7) 18. (Dept. Chem. Cleveland State Univ. Cleveland OH 44115 USA). Miller G. R. Thiourea stabilization of silver ion solutions against precipitation by light and chloride ion for atomic absorption analysis. Spectroscopy (Eugene Oreg.) 1994 9(8) 36. (Natl. Chem. Lab. Ephrata WA Winnett W. K. Murphy M. P. Novel sample introduc- tion technique for combustion total organic carbon analysis in aqueous materials. Talanta 1994 41 1627. (Dow Chemical USA Freeport TX 77541 USA). Panesar K. S. Singh 0. V. Tandon S. N. Liquid- liquid extraction and reversed-phase chromatographic behaviour of some 3d metal ions using bis- (2,4,4-trimethylpenty1)dithiophosphinic acid (Cyanex 301).Talanta 1994 41 1341. (Dept. Chem. Univ. Roorkee Roorkee India). 98823-1765 USA).95/2884 Saraswati R. Watters R. L. Jr. Determination of arsenic and selenium in spinach and tomato leaves reference materials using flow injection and atomic absorption spectrometry. TaIanta 1994 41 1785. (Inorg. Anal. Res. Div. Chem. Sci. and Technol. Lab. Natl. Inst. Stand. Technol. Gaithersburg MD 20899 USA). 95/2885 Apanasenko V. V. Reznik A. M. Smirnov A. G. Bukin V. I. Flame atomic emission and absorption determination of alkali metals gallium and aluminium in extracts involving phenol reagents. Zh. Anal. Khim. 1994 49 590. (Lomonosov Inst. Fine Chem. Technol. Moscow 117571 Russia). 95/2886 Smagunov A. V. Molchanova E. I. Pospelov A. L. Ustinova V.I. Study of the effect of steel microstructures on the intensities of X-ray fluorescence spectrum. Zh. Anal. Khim. 1994,49,623. (Irkutsk State Univ. 664033 Irkutsk 33 Russia). 95/2887 Zaksas B. I. Koryakin A. B. Labusov V. A. Popov V. I. Ryazantseva P. P. Shelpakova I. R. Multichannel analyser of atomic emission spectra. Zauod. Lab. 1994 60(9) 20. (Inst. Inorg. Chem. Siberian Sect. Russian Acad. Sci. Novosibirsk Russia). Gorlova M. N. Skorskaya 0. L. Atomic absorption determination of high concentrations of elements in alloying additions and some materials for metallurgical production. Zauod. Lab. 1994 60(9) 28. (All Russian Inst. Light Alloys Moscow Russia). Evdokimova E. V. Solov’eva M. Kb. Telegin G. F. Determination of mercury content in natural waters by the nonflame atomic absorption method using a mercury hybrid HS-3 system.Zauod. Lab. 1994 60( 8) 26. (Inst. Technol. Problems Microelectronics and Especially Pure Mater. Russian Acad. Sci. Chernogolovna Moscow Russia). 95/2890 Busev S. A. Dukhova L. A. Kalinichev A. I. Kryuchkova 0. V. Gas cell for an atomic absorption spectrophotometer. Zauod. Lab. 1994 60(9) 19. (Inst. Phys. Chem. Russian Acad. Sci. Moscow Russia). Izbash 0. A. Danitin E. S. Karpov Yu. A. Shiryaeva 0. A. Pletneva T. V. Atomic absorption determination of selenium in biological objects. Zauod. Lab. 1994 60(8) 22. (State Sci. Res. and Project Planning Inst. Rare Metal Ind. Moscow Russia). 95/2888 95/2889 95/2891 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 251 R

ISSN:0267-9477    

DOI:10.1039/JA995100229R

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Glossary of Abbreviations Whenever suitable elements may be referred to by their chemical symbols and compounds by their formulae. The following abbreviations are used extensively in the Atomic Spectrometry Updates. ac AA AAS AE AES A F AFS AOAC APDC ASV BCR CCP CMP CRM cv cw dc DCP DDC DMF DNA ECD EDL EDTA EDXRF EI E EPMA ETA ETAAS ETV EXAFS FAAS FAB FAES FAFS FANES FAPES FI FPD FT FTMS GC GD GDL GDMS Ge ( Li ) HCL hf HG HPGe HPLC IAEA IBMK ICP ICP-MS alternating current atomic absorption atomic absorption spectrometry atomic emission atomic emission spectrometry atomic fluorescence atomic fluorescence spectrometry Association of Official Analytical Chemists ammonium pyrrolidinedithiocarbamate anodic-stripping voltammetry Community Bureau of Reference capacitively coupled plasma capacitively coupled microwave plasma certified reference material cold vapour continuous wave direct current d.c.plasma dieth yldithiocarbamate N N-dimethylformamide deoxyribonucleic acid electron capture detection electrodeless discharge lamp ethylenediaminetetraacetic acid energy dispersive X-ray fluorescence easily ionizable element electron probe microanalysis electrothermal atomization electrothermal atomic absorption spectrometry electrothermal vaporization extended X-ray absorption fine structure flame AAS fast atom bombardment flame AES flame AFS furnace atomic non-thermal excitation spectrometry furnace atomization plasma excitation spectrometry flow injection flame photometric detector Fourier transform Fourier transform mass spectrometry gas chromatography glow discharge glow discharge lamp glow discharge mass spectrometry lithium-drifted germanium hollow cathode lamp high frequency hydride generation high-purity germanium high-performance liquid chromatography International Atomic Energy Agency isobutyl methyl ketone (4-methylpentan-2-one) inductively coupled plasma inductively coupled plasma mass spectrometry (ammonium pyrrolidin- 1-yl dithioformate) spectroscopy ID IR IUPAC LA LC LEAFS LEI LMMS LOD LTE MECA MIP MS NAA NaDDC NIES NIST NTA OES PIGE PIXE PMT PPb PPm PTFE QC rf REE(s) RIMS RM RSD SEC SEM SFC Si(Li) SIMAAC SIMS SIN SR SRM SSMS STPF TCA TIMS TLC TMAH TOP0 TXRF uhf uv VDU vuv WDXRF XRF SIB isotope dilution infrared International Union of Pure and Applied Chemistry laser ablation liquid chromatography laser-excited atomic fluorescence spectrometry laser-enhanced ionization laser-microprobe mass spectrometry limit of detection local thermal equilibrium molecular emission cavity analysis microwave-induced plasma mass spectrometry neutron activation analysis sodium diethyldithiocarbamate National Institute for Environmental Studies National Institute of Standards and Technology nitrilotriacetic acid optical emission spectrometry particle-induced gamma-ray emission particle-induced X-ray emission photomultiplier tube parts per billion parts per million polytetrafluoroethylene quality control radio frequency rare earth element(s) resonance ionization mass spectrometry reference material relative standard deviation signal to background ratio size-exclusion chromatography scanning electron microscopy supercritical fluid chromatography lithium-drifted silicon simultaneous multi-element analysis with a continuum source secondary ion mass spectrometry signal to noise ratio synchrotron radiation Standard Reference Material spark source mass spectrometry stabilized temperature platform furnace trichloroacetic acid thermal ionization mass spectrometry thin-layer chromatography tetramethylammonium hydroxide trioctylphosphine oxide total reflection X-ray fluorescence ultra-high frequency ultraviolet visual display unit vacuum ultraviolet wavelength dispersive X-ray fluorescence X-ray fluorescence 252R Journal of Analytical Atomic Spectrometry August 1995 Vol.10

ISSN:0267-9477    

DOI:10.1039/JA995100252R

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Selenium Speciation Using High- performance Liquid Chromatography - Hydride Generation Atomic Fluorescence with On-line Microwave Reduction LES PITTS ANDY FISHER PAUL WORSFOLD AND STEVE J. HILL* Department of Environmental Science University of Plymouth Drake Circus Plymouth UK PL4 8AA This paper describes an on-line method for the determination of inorganic selenium species in aqueous samples. Separation of the species is achieved using high-performance liquid chromatography after which the analyte is acidified before flowing through an on-line microwave system. This latter stage leaves the selenium (iv) unaltered but transforms selenium(vi) to selenium (iv) and thus converts it into a suitable oxidation state to undergo hydride generation. The selenium hydride is then determined using an atomic fluorescence detector.The method was validated by the analysis of a standard reference material (NIST SRM 1643c Trace Elements in H,O). Keywords Selenium speciation; microwave reduction; high- performance liquid chromatography; hydride generation; atomic fluorescence spectrometry An increased understanding of the various pathways that elements follow in biological environmental and medical sys- tems has resulted in the requirement that not only should these elements be determined in ever smaller quantities but also individual species should be quantitatively determined in the original sample matrix. A number of oxidation states exist for selenium; inorganic species as +6 and +4 organic species as +4 and +2 elemental selenium as 0 and selenium hydride showing a -2 state.Whilst selenium is an essential element for mammalian life it is also extremely toxic.'V2 In man and most other mammals the +4 species is more toxic than the +6.3 Thus there is a need for speciation techniques capable of unequiv- ically determining such species at low levels. Trace amounts of selenium in aqueous media are generally determined by generating the hydride from the sample fol- lowed by measurement using quartz furnace atomic absorption spectrometry (QFAAS). Since only the +4 moiety is able to generate the hydride if speciation data is required the sample has first to be analysed without pre-treatment which provides the selenium(1v) concentration then treated by heating with 6 mol 1-' hydrochloric acid which reduces any selenium(v1) to selenium(1v).The analysis is performed again to give a total figure for inorganic selenium present in the sample. The concentration of selenium(v1) is then calculated by subtracting one value from the other. This method suffers the obvious disadvantage that any error which occurs in either measure- ment will automatically affect the result for the other. In earlier work,4 we employed microwave reduction in an automated on-line technique for selenium speciation. Although this approach enabled any selenium(1v) to be determined directly it still relied upon a difference calculation to provide the concentration of any selenium(v1) present in the sample. However this system has now been further developed to include a chromatographic separation of the species prior to individual * To whom correspondence should be addressed.Journal of Analytical Atomic Spectrometry measurement. Thus the problems of indirect determination of selenium(v1) by difference have been overcome. A number of other workers have used HPLC to separate selenium ~pecies,~*~ but in general have relied upon inductively coupled plasma mass spectrometry (ICP-MS) instruments to provide the means of detection. Whilst ICP-MS is a very powerful technique for most elements when used for the determination of selenium it can suffer from several interference effects that impose severe limitations upon its use. These include isobaric interferences (e.g. 40Ar40Ar 38Ar38Ar 38Ar40Ar 40Ar36Ar and 40Ar37C1). The total natural abundance of sel- enium is split over six isotopes and this in conjunction with the high ionization energy of selenium limits the sensitivity. By coupling to an atomic fluorescence detector which offers excellent sensitivity for selenium better detection limits than those previously reported in the literature have been obtained for both selenium(1v) and selenium(vI). EXPERIMENTAL Reagents Solutions of sodium tetrahydroborate 1.3% m/v (98% Aldrich Gillingham Dorset UK) in 0.1 mol 1-' sodium hydroxide (ACS grade Aldrich) were prepared daily.Hydrochloric acid 7 mol I-' (Analar Merck Poole Dorset UK) was prepared as required. Stock solutions 100 mg l-' of sodium selenite and sodium selenate (99% Aldrich) were prepared and 5 ng ml-I working strength solutions were pre- pared as required and kept in polythene bottles whilst in use. Fresh working strength solutions were prepared hourly so as to avoid any possible losses.Solutions of potassium sulfate 25 and 100 mmol I-' (Fluka Gillingham Dorset UK) were used as the mobile phase. Apparatus A schematic diagram of the system is shown in Fig. 1. Samples were introduced via a switching valve (Rheodyne type 7125 Anachem Luton UK) to a 5 cm x 4.6 mm high-capacity anion- exchange column (BAX-10 Benson Reno NA USA). The pump used was a Model 6000A (Waters Associates Milford MA USA). The eluent then passed through a heating coil contained in the microwave unit (Microdigest 301 Prolabo Paris France) and through reaction and cooling coils to a gas-liquid separator (PS Analytical Orpington Kent UK). Details of the coils are given in a previous p~blication.~ The selenium hydride was then purged into a fluorescence detector (Excalibur PS Analytical).A hydride generator (10.004 PS Analytical) was used as a pump for the hydrochloric acid and sodium tetrahydroborate and also uia the software (Touchstone PS Analytical) to provide timing for various operations. Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 51 9Switching Reaction Cooling valve HPLC colum Microwave coil coil I 4 0 Eluent 1 - . Eluent 2 Drier tube .= Sample . loop * i Peak area 775.7% s Peak height 38.40% fluorescence . . . . . . . . . . . . . . . . .... - ... . . a Mixina valve ' I ! - .......... U ~;go" purge Gas-liquid separator Table 1 Optimized conditions HPLC Sample loop Sample pH Mobile phase 1 Mobile phase 2 Mobile phase switching HPLC flow rate Microwave power Hydride generation Reductant flow rate HC1 flow rate Argon purge flow rate Argon drier flow rate Primary lamp current Boost lamp current Gain Detector 1 ml 7 25 mmol 1-' K2S04 pH 5 100 mmol 1-' K2S04 pH 5 200 s 2.0 ml min-' 20% continuous 4 ml min-' 8 ml min-' 350 ml min-' 1OOO ml min-' 25 mA 25 mA looox 10 Fig.1 System block diagram Table 2 Analysis of a mixed selenium standard (5 ng ml-' Se'" and Se'") ~ ~~ ~~ - Peak area/s Analysis SeIv SeV' 100 200 300 400 500 600 Time/s Fig.2 Chromatogram of 5 ngml-' mixed standard under optim- ized conditions Procedure The first part of this study involved optimizing the chromato- graphic system to achieve base-line separation of the analyte species.In order to achieve this the system was set up as shown in Fig. 1 and a number of different mobile phases were evaluated with a mixed standard containing 5 ng ml-I of selenium as both selenite and selenate. Initially low concen- trations (100 mmol 1-') of phthalate were used. This provided a good separation but the system suffered from the formation of phthalic acid crystals when the eluent stream met the hydrochloric acid which in time led to a blocking of the system. Potassium sulfate was then used as the mobile phase. This provided excellent separations when using a step concen- tration gradient i.e. 25 mmol 1-1 at pH 5 for the first 200 s and then switching to 100mmol 1-' at a similar pH for the remainder of the run. A number of different sample pHs were also evaluated between pH 5-7 with no discernable differences occuring in peak shape or peak area.The optimized chromato- graphic conditions and microwave and detector parameters are given in Table 1. Details of the optimization of the micro- wave are given in an earlier p~blication.~ RESULTS AND DISCUSSION Once baseline separation of the inorganic selenium species had been achieved and the operating conditions optimized five identical injections of the mixed standard were made and the peak areas measured. The results are shown in Table 2. As can be seen the precision offered by the system is in the order of 1.5 and 2.0% RSD for selenite and selenate respectively. The limits of detection were then determined for selenium(1v) and selenium(v1) and were found to be 0.2 and 0.3 ng ml-' respectively.1 2 3 4 5 Mean S,-1 LOD (3 x S " - d 761 776 770 76 1 788 771.2 s 11.34 s 0.22 ng ml-' 249 238 249 247 241 244.8 s 5.02 s 0.31 ng ml-I Finally a Standard Reference Material (NIST SRM 1643c Trace Elements in HzO) was analysed and found to contain 10.6 ng ml-' of selenium(1v) and 2.8 ng ml-' of selenium(vI) giving a total selenium concentration of 13.4 ng ml-I (certified value 12.7 k0.7 ng ml- '). No reference material is currently available with certified values for individual selenium species. This technique therefore enables the direct determination of sub-ng ml- ' levels of selenium(1v) and selenium(w). Higher concentrations of selenium(1v) can lead to an elevated baseline although this can be overcome by dilution. Work is now continuing to extend this methodology to organoselenium species. The authors would like to thank the Engineering and Physical Research Council and PS Analytical for the provision of a CASE Studentship to L.P. They would also like to thank Prolabo for the loan of the microwave unit. REFERENCES McKenzie H. A. and Smythe L. E. Quantative Trace Analysis of Biological Materials Elsevier Amsterdam 1988 487. Dubois F. and Belleville F. Pathol. Biol. 1988 36 1017. Thienes C. and Haley T. J. Clinical Toxicology Lea and Febiger 1972 208. Pitts L. Worsfold P. and Hill S. J. Analyst 1994 119 2785. Crews H. presented at the ASU-ASG Meeting Bristol UK March 30 1995. Laborda F. Chakraborti D. Mir J. M. and Castillo J. R. J . Anal. At. Spectrom. 1993 8 643. Paper 510231 7C Received April 11 1995 Accepted April 20 1995 520 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10

ISSN:0267-9477    

DOI:10.1039/JA9951000519

出版商:RSC    

年代:1995

数据来源: RSC

摘要:

Effect of Acids Modifiers and Chloride on the Atomization of Aluminium in Electrothermal Atomic Absorption Spectrometry Journal of Analytical Atomic Spectrometry SHIDA TANG Department of Environmental Health and Toxicology School of Public Health State University of New York at Albany Albany N Y 12201 USA PATRICK J. PARSONS* Wadsworth Center New York State Department of Health PO Box 509 Albany N Y 12201 -0509 USA and Department of Environmental Health and Toxicology School of Public Health State University of New York at Albany Albany N Y12201 USA WALTER SLAVIN Bonaire Technologies Box 1089 Ridgejeld CT06877 USA The effect of HNO HCI and H2S04 as well as various modifiers Mg ( Pd ( Ca ( N03)2 and N)14H2P04 on the atomization of aluminium from a L'vov platform in electrothermal atomic absorption spectrometry was investigated.No interference was observed on the integrated absorbance of A1 from any acid studied. The m observed for 10 pg 1- ' (200 pg) A1 aqueous solution prepared by diluting a commercial A1 stock solution with doubly deionized water was much poorer than expected owing to a failure to transfer A1 to the furnace it could be corrected by adding as little as 0.25% v/v of a mineral acid. The expected m for A1 was unaffected by modifiers such as Mg(N03)2 Pd(N03)2 Ca(NO,) and NH.,H2P04. Addition of either calcium magnesium or palladium nitrates produced a sharper absorbance peak and A1 was delayed in appearance. Either Ca( NO& or Mg( can stabilize A1 during pyrolysis allowing a very high (> 1700 "C) thermal pretreatment temperature to be used.However multiple atomization peaks were observed when using Mg(NO,),. The multiple peaks became more troublesome as the tube aged. Calcium nitrate recommended as a better modifier for those samples (e.g. bone) in which Ca is a large component of the matrix. A serious interference from chloride salts varied with chloride concentration pH and pyrolysis temperature. This is 'suppressive' interference from chloride was overcome by using Ca(N03)2 as a modifier in HNO and a pyrolysis temperature in excess of 1400 "C. Keywords. Aluminium; mineral acid; modifier; chloride interference; electrothermal atomic absorption spectrometry Aluminium is the most abundant metal in the lithosphere and is widely used for various purposes. In its hydroxide form Al(OH) it is used as a gastric antacid.As the sulfate A1,(S04)3 it is used as a deflocculant in domestic water treatment. During the 1970s it was discovered that patients on long-term hemodialysis developed a progressively fatal neurological condition later called dialysis dementia,' that was subsequently associated with exposure to A1 from the water supply used with dialysis equipment. This neurologic condition is now clearly attributed to an increased A1 body burden specifically bioaccumulation of A1 in brain bone and other tissues.' Because of this there has been much interest in * To whom correspondence should be addressed. measuring A1 in serum/plasma and in other fluids and tissues to develop understanding of the association and for biological monitoring purposes.The added possibility that A1 may be an aetiological factor in Alzheimer's Disease is another reason for the increased interest in the biological significance of this element.2-7 In fact occupational exposure to A1 has long been associated with neurobehavioural toxicity.' Development of an accurate and precise analytical method for the determination of A1 in biological tissues is fundamental to understanding its biological role. There are many analytical techniques for the determination of Al.9 From practical con- siderations of the required sensitivity sample size throughput contamination control and cost electrothermal atomization atomic absorption spectrometry (ETAAS) is the method of choice at least for biological materials." However there are still significant problems with the determination of A1 by ETAAS as evidenced by numerous publications documenting difficulties with various modifiers and acid media.Various methods for A1 in biological matrices have proposed Mg (NO,) ' ' *I2 NH4N0,,13 K,Cr,O7,l4 NH315 and NH4H2PO4l6 as the optimum modifier for this analysis by ETAAS. Different acid media have also been proposed includ- ing HNO3,l7 H2S0415*'8 and H3P04.19 In this paper we report the effect of several acids including HN03 HCl and H2S04 on A1 atomization and try to resolve some of the confusing and conflicting reports in the literature. In addition we report the effect of several modifiers proposed for Al including Mg(N03)2 Ca(NO,) Pd(NO,) and NH4H2P04 on the atomization of A1 from a solid pyrolytic L'vov platform.Chloride interference was also studied because C1 is a major constituent of most biological tissues and fluids. The primary aim of our work is to identify the best modifier and acid medium for the determination of A1 in serum bone and other biological samples by ETAAS. A detailed description of the final analytical method for measuring A1 in serum bone and other biological matrices will be presented elsewhere. EXPERIMENTAL Instrumentation All A1 measurements were carried out on a Model 25100 atomic absorption spectrometer (Perkin-Elmer Norwalk CT USA) equipped with an HGA-600 graphite furnace and a transverse Zeeman-effect background correction system. Pyrolytic graphite coated graphite tubes with a pre-installed forked-platform (P-E PN B0505057) made of solid pyrolytic Journal of Analytical Atomic Spectrometry August 1995 Vol.10 521graphite were used throughout the study. A Model AS-60 autosampler was used to deposit 2Opl samples onto the platform. The PE Z 5 100 was interfaced to a personal computer running Perkin-Elmer's proprietary software (version 6.0). Background and corrected absorbance peak data were extracted from the *.dat files using a customized program (peak.exe ver. 2.01) provided by Perkin-Elmer. ASCII files containing these data were transferred to an Apple Macintosh personal computer and imported into a graphical plotting package (Deltagraph Pro). Using this procedure peak profiles could be faithfully replotted from the original AA data col- lected and superimposed to reveal important details The 25100 conditions for A1 are given in Table 1 and the HGA-600 furnace programme in Table 2.The analytical wavelength selected for this study was the line at 309.3 nm. This line is about 20% more sensitive (mo= 11 pg) than the 396.2 nm line (mo = 14 pg) but is limited by a shorter linear dynamic range.20 It may be preferable to use the more sensitive 309.3 nm line for ultra-trace analytical work (e.g. to establish normal A1 concentrations in bone brain or other biological materials). However many applications (e.g. routine serum Al) are better conducted with the 396.2 nm line which has a greater linear dynamic range. The choice of analytical wavelength here did not affect the experiments conducted for the purposes of this study. Materials and Reagents Because glass contains small amounts of Al which could be a significant source of contamination for ultratrace work poly- propylene containers were used in this study.Owing to the ubiquitous nature of A1 in the laboratory environment all pipette tips autosampler cups and polypropylene containers were soaked in 2% v/v nitric acid for 24 h and rinsed thoroughly with doubly de-ionized (DI) water (Milli-Q system Millipore Corporation Bedford MA USA). Acid-washed materials were air-dried under dust-free conditions in an in-house constructed drying box. A working stock solution (100 pg 1-l Al) was prepared by serial dilution of a lo00 mg 1-l A1 standard solution (Aldrich Chemical Company Milwaukee WI USA) with DI water. Ultrapure-grade concentrated HN03 HCl and H2S04 were used (Baker Instranalyzed J.T. Baker Phillipsburg NJ USA) along with sub-boiling distilled HNO [National Institute of Standards and Technology (NIST) Gaithersburg MD USA]. Modifiers were prepared Table 1 Instrument conditions Instrument Furnace Autosampler Background correction Light source Wavelength Spectral bandwidth Measurement mode Graphite tube Injection volume Internal gas flow Perkin-Elmer Model Zeeman 25100 PC HGA 600 Transverse ac Zeeman Aluminium hollow cathode lamp 25 mA 309.3 nm 0.7 nm Peak area absorbance 5.0 s integration Pyrolytic graphite coated graphite tube with solid pyrolytic forked platform 20 p1 AS-60 Argon 300 ml min-' Table 2 HGA-600 graphite furnace condition Dry Pyrolysis Atomization Clean TemperaturePC 230 1200 2500* 2600 Ramp/s 10 5 0 1 Hold/s 50 30 5 10 Argon gas flow rate/ml min-' 300 300 0 300 by dissolving ultrapure reagents (Puratronic Johnson Matthey Royston UK) in 1% HN03.pH Measurements Two sets of A1 solutions were prepared at pH values ranging approximately from 0.5 to 7.0 by titration with HN03 or NaOH. The pH of each solution was measured using a pH meter with a combination glass electrode (DIGI-SENSE Cole Palmer Instrument Company Chicago IL USA). RESULTS AND DISCUSSION Acids Solutions containing A1 at 10 pg 1-l (200 pg) were prepared by diluting the stock solution (100 pg 1-I) with unacidified DI water and mineral acids including HN03 HCl and H2S04. The solutions were analysed for A1 by ETAAS and the integrated absorbances (Ai) recorded at different acid concen- trations (0-8%).We did not investigate HC104 owing to its hazardous nature. The atomization of 200pg A1 from an unacidified solution resulted in sensitivity poorer than expected (mo = 19 pg expected mo= 10 pg). We found that acidification with as little as 0.25% v/v of any common mineral acid was sufficient to recover the expected mo. We found no interference from either HNO or HC1 up to the maximum concentration studied 8% v/v. This disagrees with an earlier report where an interference from HCl and HNO was explained by formation of gaseous AlC13 molecules during pyrolysis and formation of stable A~N(s).~' Matsusaki et a1.22 also failed to observe any inter- ference from HCl. It is likely that in the case of hydrochloric acid Cl is removed during pyrolysis as gaseous hydrogen chloride.Our observation that unacidified aqueous A1 solutions of relatively low concentrations (10 pg I-') gave poorer sensitivity than expected led us to consider pH as a factor in the determination of Al. Aqueous solutions containing either 200 or 600pg A1 at various pH levels were prepared by titration with either HN03 or NaOH. Each solution was analysed for A1 by ETAAS and the Ai data collected. Fig. 1 shows how pH affects A1 integrated absorbance. All analytical measurements were carried out in triplicate with blank correction and the error bars represent the range of Ai values obtained. As the pH of a 200 or 600 pg A1 solution approaches neutral the A1 integrated absorbance decreases. This is probably due to precipitation of A1 as insoluble aluminum hydroxide Al(OH) .The measured pH of aqueous 200 and 600pg A1 solutions diluted with unacidified water were approximately 5.6 and 5.1 respectively. However the pH is difficult to estimate in these essentially unbuffered solutions. The lower pH i.e. more acidic nature of the 600pg solution can be explained by the larger 0.31 * Atomization temperature of 2400°C was used for the study with Ca. Fig. 1 Effect of pH on (0) 200 pg A1 and (0) 600 pg A1 522 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10aliquot of acidified stock transferred during the dilution. The more acidic 600pg solution would also explain the better m achieved than with the 200pg solution without further acidification. The chemistry of A1 in aqueous solution is highly pH dependent in that A1 solubility decreases from pH 3.0-5.0 reaches a minimum between pH 5.5 and 6.0 and increases as the pH increases further to 7.0.At very low pH A13+ is present almost entirely as the hydrated cationic complex [A1(H20)6]3'. As the pH approaches 5.0 the hydrated cationic complex undergoes base hydrolysis to form several aquahyd- roxy species and precipitates as Al(OH),(s) at pH 6.0. Thus conceivably A1 precipitation does occur to some extent in unacidified solutions and this may be the reason for the observed poor sensitivity. Possibly the poorer sensitivity may also be due to some adsorption of A1 aquahydroxy species on the vessel wall at pH 5.0-6.0. We confirmed that the poor sensitivity observed with A1 solutions at pH approaching neutral is caused by a failure to transfer A1 into the furnace.A solution containing a known amount of A1 (200 pg) in 1% HNO (pH M 1.2) was analysed for A1 in the presence of various aliquots of 0.25 moll-' NaOH injected separately by the autosampler onto the plat- form. No change in the integrated absorbance of A1 was observed although the pH of the mixture on the platform changed from 1.2 to 12.4. Thus it would appear that reports of sensitivity 'enhancement' due to acidification are only observed for A1 solutions with relatively high pH values (pH > 5.0) where a failure to transfer A1 to the furnace occurred due to precipitation of Al(OH) or adsorption of hydrolysed species on the vessel wall. 0 Modifiers Atomization curves for 200 pg A1 in 1% HNO with different modifiers were obtained by varying the atomization tempera- ture while keeping the pyrolysis temperature constant at 1200 "C [Fig.2(a)]. Having established the optimum atomiz- ation temperature for each modifier we then obtained corre- sponding pyrolysis curves [Fig. 2(b)]. The small difference in Ai of Fig. 2(b) is caused by differences in atomization tempera- ture and different tubes used. All analytical samples were prepared in 1% HNO to eliminate the pH effect described above. Using the optimized furnace parameters obtained from the data in Fig. 2 we compared the performance of Mg(N03) with Ca(NO,) as modifiers for A1 in ETAAS. Atomization profiles for 200pg A1 in the presence of various amounts of Mg(N03)2 and Ca(NO,) in new and aged tubes are shown in Fig.3. .\;\'\a 1 -A- No modifier 1 I I I Magnesium nitrate Magnesium nitrate has been the most widely used modifier for A1 determinations by ETAAS. It was first proposed for determi- nation of A1 over a decade ago.l1*l2 In that paper," it was reported that different amounts of Mg(N03) had no effect on A1 integrated absorbance and we have confirmed this obser- vation with the forked platform. Aluminium was also stabilized by Mg(N03) during pyrolysis up to temperatures of M 1900 "C [Fig. 2(h)] and the appearance of A1 in absorption was delayed. The peak absorbance was subs tantially increased as the amount of Mg deposited on the platform was increased up to 50 pg [Fig. 3(a)]. The integrated absorbance remained largely unchanged (mean Ai = 0.077 f 0.002). However as the mass of Mg deposited on the platform approached 50 pg the atomization peak split into two components.This became more troublesome as the tube/platform aged even with pre- viously recommended amounts of 50 pg Mg(N03) ( M 8 pg Mg) on the platform." Multiple atomization peaks of A1 I . I /% -E+.. Pd +- NH H PO -A- No modifier a .p 0 4 2 . . 4 E5 d.; s o . 2 1700 1900 2100 2300 2500 2700 a Fig.2 Atomization (a) and pyrolysis (b) curves for 200pg A1 with 50 pg Mg(N03)2 (0) 10 pg Ca as Ca(N03)2 (O) 15 pg Pd as Pd(N03) (0) and 125 pg H,PO,- (+ ) and without any modifier (A). For the atomization curves in (a) a fixed pyrolysis temperature of 1200°C was used; for the pyrolysis study in (b) an atomization temperature of 2500 "C was used except for Ca where 2400 "C was used increased in complexity as the amount of Mg(N03)2 was increased as shown in Fig.3(b) with a moderately aged tube of approximately 200 firings. Manning et ~ 1 . ' ~ also reported multiple atomization peaks for A1 but only in the presence of MgCl,. Although such problems make peak absorbance measurements quite unre- liable changes in Ai are of course much smaller. This kind of problem is a good example of why peak area or integrated absorbance is preferable to peak height absorbance measure- ment in ETAAS. In the case of A1 with Mg(N0,)2 modifier even using integrated absorbance measurements within-run precision is a little worse (RSD=2.2% n=120) than that obtained with Ca(N0,)2 modifier (RSD= 1.4% n= 120) with an aged tube of 100 firings. Moreover the multiple atomization peak problem cannot be overcome by increasing pyrolysis temperatures or by the addition of a cool-down step before atomization. Calcium nitrate The 'enhancement' effect of Ca(N03) on A1 absorbance reported in the l i t e r a t ~ r e ~ ~ - ~ ~ is most likely due to use of peak height measurements rather than integrated absorbance.In agreement with Manning et we also found no enhance- ment of A1 on integrated absorbance from Ca(NO,),. The pyrolysis curve for A1 in the presence of Ca(NO,) in Fig. 2(b) shows that Ca(NO,) stabilizes A1 during pyrolysis up to a temperature of about 1700°C. An interesting feature of the atomization curve for A1 in the presence of Ca(N03)2 [Fig. 2(a)] is the significantly lower temperature required to atomize Al with Ca( NO3) compared with other situations.The optimum atomization temperature with Ca(NO,) is some 200°C less than that required with either Mg(N03) or other modifiers. Like Mg the use of Ca altered the A1 atomization Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 52350 c19 0.47 0.2 - 0- Mg-new tube ( d ) Ca-aged tube 10 c19 d 0 1 2 3 4 :S Mg-aged tube 0.2 4 0 1 2 3 4 5 Ca-new tube Time/s Fig. 3 Atomization profiles for 200 pg A1 with different amounts of Mg or Ca modifier in new and aged (200 firings) tubes profile with delayed appearance time and increased peak absorbances. As the amount of Mg(NO,) was increased the A1 peak appearance time was delayed [Fig. 3(a)]. But as Ca(N03) was increased the appearance time of the A1 peak remained constant [Fig.3(c)]. In an aged tube with Ca(N0,)2 the A1 atomization peaks obtained were still symmetric and sharp [Fig. 3(d)] although not as sharp as with a new tube. The A1 appearance time as with new tubes was also delayed but independent of the amount of Ca deposited on the platform. The conclusion based on these results is that Ca as Ca(N0,)2 is a good modifier for the determination of A1 by ETAAS especially in bone or other biological samples that have relatively high Ca content. Addition of Ca(N03) as a modifier to the standards is necessary to ensure that A1 atomization will be similar to that in bone samples. Liang2' avoided adding a modifier directly to A1 standards but had to pretreat the L'vov platform with bone digestate several times prior to calibration. The memory effect from depositing a Ca-rich matrix on the platform resulted in an absorption profile that was very similar to bone samples.We also observed a memory effect from Ca when studying the modification effects on Al. However the memory effect from Ca gradually disappeared after several firings. Thus we found it preferable to add Ca(NO,) as a modifier to A1 standards and ensure identical atomization behaviour with samples. Palladium nitrate Palladium nitrate mixed with magnesium nitrate has been proposed as a universal modifier28 and this approach has been applied for the determination of more than 20 elements by ETAAS.,' In this work however we investigated palladium nitrate alone as a modifier for the determination of A1 by ETAAS. Pyrolysis and atomization curves for A1 in the presence of Pd are shown in Fig.2(a)-(b). We found that using Pd(N03) modifier provided no stabilization for A1 during pyrolysis [Fig. 2(b)]. However Pd did delay the A1 appearance time and increased the peak absorbance but integrated absorbances remained unchanged (data not shown). As with Mg(N03)2 the appearance time was increasingly delayed with increasing mass of Pd(N03) deposited on the platform. However we observed multiple A1 atomization peaks with Pd(N03)2 too especially with aged tubes. Thus we could find no advantage in using Pd(N03) as a modifier for Al. Ammonium dihydrogen phosphate In an early study Garmestani et aL3' observed an enhancement effect for A1 using K2HP04. However since they used peak absorbance measurements the reported enhancement was probably due to changes in atomization profile.Manning et ~ 1 . ' ~ found no effect on A1 absorbance from up to 200 pg Na2HP04 when a tungsten wire atomizer was used. Radunovic et ~ 1 . ' ~ used NH4H2P04 as a modifier for determining A1 in various biological samples using similar equipment. Those authors claimed NH4H2P04 was preferable to Mg(NO,) for measuring A1 in bone and sera because the former permits pyrolysis temperatures of up to 1400°C without any loss and because the ammonium salt facilitates chloride removal from NaCl as volatile NH4Cl. However we found Ca(NO,) preferable to NH4H2P04 for determination of Al especially in those matrices which are either Ca-rich and/or contain Cl (discussed below). We found that using NH4H2P04 produced a similar pyrolysis curve to the situation without any modifier [Fig.2(a)] and did not change the A1 peak absorbance (data not shown) as did Ca( NO,) and Mg( NO3) (Fig. 3). 524 Journal of Analytical Atomic Spectrometry August 1995 Vol. 10Chloride Interference Interferences from chloride on A1 absorbance have been well documented and widely r e p ~ r t e d . " - ~ ~ * ~ ~ A suppressive effect from chloride on A1 is generally attributed to the loss of A1 during pyrolysis because of the volatile nature of AlCl (subli- mation point 177.8 "C). Matsusaki et ~ 1 . ~ ~ investigated chloride interference on Al and observed different levels of absorbance suppression by several chloride salts. They also reported that adding HNO eliminated the suppression effects of both NaCl and KCl but a similar effect from CaCl could only be eliminated by adding ( NH4)4EDTA. Using new pyrolytic graphite coated graphite tubes with a L'vov platform and small (< 50 pg) amounts of CaCl Slavin et aL3' were unable to replicate the suppressive effect of CaC1 reported by Matsusaki.The interference from CaCl was found to increase with tube age and it was suggested that this could have been caused by erosion of the pyrolytic coating. It was concluded that in aged tubes a large proportion of the CaCl matrix is still present during atomization and then causes typical vapour-phase interferences between A1 and C1. The interference from chloride in the determination of A1 was studied using CaCl and NaCl as sources of chloride. We found no interference on 200 pg of A1 from small (<20 pg) amounts of CaCl but an interference from CaCl was observed when the amount of CaCl was greater than 20pg using a pyrolysis temperature of 1200 "C.This interference worsened with increasing amount of CaCl deposited on the platform. The pyrolysis characteristics of 200 pg A1 in the presence of 330 pg (6 pmol C1-) CaCl at different concentrations of HNO are shown in Fig. 4(a). The interference on the integrated absorbance of A1 from CaCl is clearly evident at pyrolysis temperatures of <1400°C. However it is interesting to see that the interference disappears at pyrolysis temperatures above 1400 "C until the temperatures exceed 1700 "C when A1 is lost. This result suggests that the CaCl interference with A1 is due to formation of a stable molecular species containing A1 during the atomization rather then the pyrolysis step.If A1 were lost as AlCl during pyrolysis the interference would be expected to be more serious at higher pyrolysis temperatures (> 1400 "C). But the experimental results are just the opposite. That means that large amounts of C1 must still be available during the atomization step if pyrolysis temperatures of <1400"C are used and this results in the vapour-phase interferences between A1 and Cl. Reason(s) for the remaining large amounts of C1 after pyrolysis at temperatures of < 1400°C might be that chloride was left on the platform as undecomposed salt(s) because of the low pyrolysis temperature used or some Cl was trapped at the cold ends of the tube.What is really happening requires further studies. Our experiments also show that this inter- ference can be reduced by increasing HNO concentrations to 5% v/v at pyrolysis temperatures of < 1400 "C [Fig. 4(a)]. This observation supports the suggestion that the CaCl interference is due to inefficient removal of C1 during pyrolysis because of the low pyrolysis temperatures (< 1400 "C) used. If C1 is trapped at the cold ends of the tube increase of HNO concentration would be expected to have no effect on the interference produced by C1. Increasing the HNO concentration helps to remove Cl most likely as volatile HCl gas during the pyrolysis step since the Cl interference is removed. Thus the interference from CaCl can be eliminated by employing a high HNO concentration (5% in this case) or by keeping the pyrolysis temperature between 1400-1700 "C.We investigated the Cl interference further using higher concentrations of NaCl. Pyrolysis curves for 400pg A1 in the presence of 585 pg NaCl(l0 p o l C1-) with 1% HNO 10% HNO and 10% HNO,+ 10 pg Ca as Ca(N03) are shown in 0. e Q) 0 c 800 1200 1600 2000 0.054 * 10% HN03 I I 8' . . \ o ! c G c $ m l 200 600 1000 1400 1800 I 2200 1 I I ndicated tern pe rat u re/' C Fig. 4 Pyrolysis curves for A1 showing interferences from two chloride salts (a) 200 pg A1 plus 330 pg CaC1 (6.0 pmol 1-' C1-) in 1% and 5% HN03; and (b) 400 pg A1 plus 585 pg NaCl(l0 pmol 1-I C1-) in 1% and 10% HN03 and 10% HN03 plus 1Opg Ca as Ca(NO,),. Atomization temperature = 2400 "C Fig. 4(b). A similar but more pronounced suppressive effect on A1 is observed from NaCl compared with CaCl,.Furthermore this interference is only partially reduced by increasing the HNO concentration to 10%. Increasing the HNO concen- tration does not eliminate C1 interference completely in this case because without a modifier such as Ca which can stabilize A1 as in the case of CaCl some A1 is lost at pyrolysis temperatures > 1400 "C [Fig. 2(b)]. However a complete recovery is possible by using 1Opg Ca as Ca(N03)2 with 10% HNO,. This agrees well with the CaCl results in that Cl interference is due to formation of a stable molecular species containing A1 during atomization because of inefficient removal of Cl during pyrolysis. This conclusion is also supported in part by the atomic and background absorption profiles of 400 pg A1 in the presence of 585 pg NaCl shown in Fig.5. A large background absorbance signal (Ai = 0.429) but very small atomic absorbance signal (Ai = 0.004) is observed when a pyrolysis temperature of 800°C is used (Fig. 5). The back- ground absorbance signal is greatly reduced (94.4%) by raising the pyrolysis temperature to 1400 "C (Fig. 5) and the atomic absorbance signal is greatly recovered (Ai = 0.103) at the same time. CONCLUSIONS In this study we investigated the effect of mineral acids modifiers and chloride interference on the determination of A1 by ETAAS using forked platforms. Poorer than expected sensitivity or characteristic mass (mo) for A1 solutions of low pg 1-' concentrations was observed if the solutions were prepared by serial dilution of a commercial A1 stock solution with DI water.This is most likely caused by a failure to transfer A1 to the furnace owing to precipitation of A1 as Al(OH) or adsorption of hydrolysis species on the vessel wall at pH>5. Acidification of aqueous A1 solutions with any mineral acid studied results in a recovery of the expected mo Journal of Analytical Atomic Spectrometry August 1995 Vol. 10 525( a 1 o'61 BK (A = 0.429) 0*4i ' Pyrolysis at 800 "C \ \ I I 1 \ 0.2 i AA (4 = 0.004) ,' 1 2 3 I y \ Pyrolysisat 1400°C 0.1 1 BK (Ai = 0.024)/ \ 0 1 2 3 Time/s Fig. 5 Atomization and background absorption profiles for 400 pg A1 in 1% HNOJ plus 585 pg NaCl (10 pnol I-' Cl-) at a pyrolysis temperature of 800-1400 "C for A1 by ETAAS.Discrepancies in the literature reported for effect of acids on A1 can be explained by use of standards of different pH values. Reported enhancement effects due to modifiers may also be due to acidification of their aqueous solution since modifier solutions are generally prepared in dilute acid. We recommend using a 1% HN03 acid medium for standards and samples (if possible) in the determination of A1 by ETAAS. Integrated absorbance of A1 was unaffected by using either Ca(N03)2 Pd(N03)2 Mg(N03)2 or NH4H2P04 as modifiers in 1% HN03. Many A1 interference problems have been reported in the early literature which are now understood to be the result of using peak height absorbance to quantitate the A1 signal. This work shows the sensitivity of the peak shape (thus peak height absorbance) to the matrix composition.Most of the modifiers evaluated here result in increased peak height absorbance because the peak width at half height is smaller i.e. the peaks are sharper but the integrated absorbance remains unchanged. As the integrated absorbance is a better indicator of the extent of free atom formation it is almost always preferable in quantification instead of peak height absorbance. The aluminium atomization profile suffers from multiple peaks with the most widely used modifier Mg(N03)2 especially in aged tubes. Our results support Ca as a modifier preferable to Mg for the determination of A1 in samples rich in Ca such as bone and many other biological matrices. A substantial interference from chloride on A1 was found to depend upon Cl concentration HN03 concentration and pyrolysis temperature.Our results have shown that this inter- ference is caused by loss of A1 during atomization rather than during pyrolysis. After pyrolysis at temperatures of < 1400 "C large amounts of Cl remain owing to undecomposed chloride salt@) on the platform or trapping of some C1 at the cold ends of the tube. The chloride interference was effectively eliminated by using Ca(N03) as modifier in HN03 and a pyrolysis temperature 1400-1700 "C. We are grateful to Glen Carnrick of Perkin-Elmer for helpful discussions and John McCaffrey of Perkin-Elmer for providing the computer program for extracting the atomization data from peak files. REFERENCES 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Alfrey A.C. LeGendre G. R. and Kaehny W. D. N. Engl. J. Med. 1976 294 184. Crapper D. R. Krishnan S. S. and Quittkat S. Brain 1976 99 67. Perl D. P. Pendlebury W. W. and Munoz-Garcia D. in Proceedings of the First International Symposium on Geochemistry and Health ed. Thornton I. Science Reviews Northwood UK McLachlan D. R. Neurobiol. Aging 1986 7 525. Katzman R. N. Engl. J. Med. 1986 314 964. McLachlan D. R. Lukiw W. J. and Kruck T. P. Can. J. Neurol. Sci. 1989 16 490. Eichhorn G. L. Exp. Gerontol. 1993 28 493. McLaughlin A. T. G. Kazantzis G. King E. Teare O. Porter R. J. and Owen R. Brit. J. I d . Med. 1962 19 253. Savory J. and Wills M. R. Kidney. Int. Suppl. 1986 18 S24. Cedergren A. and Frech W. Pure Appl. Chem. 1987 59,221. Slavin W.Carnrick G. R. and Manning D. C. Anal. Chem. 1982 54 621. Manning D. C. Slavin W. and Carnrick G. R. Spectrochim. Acta Part B 1982 37 331. Smeyers-Verbeke J. and Verbeelen D. Anal. Chem. 1988,60,380. Shan X. Luan S. and Ni Z. J. Anal. At. Spectrom. 1988 3 99. Gitelman H. J. and Alderman F. R. Clin. Chem. 1989,35/7,1517. Radunovic A. Bradbury M. W. B. and Delves H. T. Analyst (Cambridge U K ) 1993 118 533. Oster O. Clin. Chim. Acta 1981 114 53. Toda W. Lux J. and Van Loon J. C. Anal. Lett. 1980 13 1105. Craney C. L. Swartout K. Smith F. W. I. and West C. D. Anal. Chem. 1986 58 656. Manning D. C. and Slavin W. At. Spectrom. 1986 7 123. Persson J-A. Frech W. and Cedergren A. Anal. Chim. Acta,. 1977 92 95. Matsusaki K. Yoshino T. and Yamamoto Y. Tulanta 1979 26 377. Martin R. B. in Aluminium and Renal Failure eds. De Broe M. E. and Coburn J. W. Kluwer Academic Publishers Thompson K. C. Godden R. G. and Thomerson D. R. Anal. Chim. Acta 1975 74 289. Dolinsek F. Stupar J. and Spenko M. Analyst (Cambridge UK) 1975 100 884. Liang L. D'Haese P. C. Lamberts L. V. and De Broe M. Clin. Chem. 1991 37 461. Liang L. Spectrochim. Acta Part B 1992 47 239. Schlemmer G. and Welz B. Spectrochim. Acta Part B 1986 41 1157. Welz B. Schlemmer G. and Mudakavi J. R. J. Anal. At. Spectrom. 1992 7 1257. Garmestani K. Blotcky A. J. and Rack E. P. Anal. Chem. 1978 50 144. Slavin W. Manning D. C. and Carnrick G. R. Anal. Chem. 1981 53 1504. 1985 pp. 227-235. 1990 pp. 7-26. Paper 410 7 3 0 7 J Received November 11 1994 Accepted April 11 1995 526 Journal of Analytical Atomic Spectrometry August 1995 .Vol. 10

ISSN:0267-9477    

DOI:10.1039/JA9951000521

出版商:RSC    

年代:1995

数据来源: RSC