摘要:

Journal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates - Formerly ARAAS) JAAS Editorial Board" Chairman: L. C. Ebdon (Plymouth, UK) J. Egan (London, UK) M. S. Cresser (Aberdeen, UK) D. L. Miles (Wallingford, UK) B. L. Sharp (Aberdeen, UK) M. Thompson (London, UK) A. M. Ure (Aberdeen, UK) *The JAAS Editorial Board reports to the Analytical Editorial Board, Chairman J. D. R. Thomas (Cardiff, UK) JAAS Advisory Board F. C. Adams (Antwerp, Belgium) R. M. Barnes (Amherst, MA, USA) L. Bezirr (Budapest, Hungary) R. F. Browner (Atlanta, GA, USA) S. Caroli (Rome, Italy) L. de Galan (Delft, The Netherlands) J. 6. Dawson (Leeds, UK) K. Dittrich (Leipzig, GDR) W. Frech (UmeA, Sweden) K. Fuwa ( Tokyo, Japan) A. L. Gray (Guildford, UK) S. Greenfield (Loughborough, UK) G.M. Hieftie (Bloomington, IN, USA) G. Horlick (Edmonton, Canada) 6. V. L'vov (Leningrad, USSR) J. M. Mermet (Villeurbanne, France) N i Zhe-ming (Beijing, China) N. Omenetto (lspra, Italy) E. PIGko (Bratislava, Czechoslovakia) R. E. Sturgeon (Ottawa, Canada) R. Van Grieken (Antwerp, Belgium) A. Walsh,.,K. B. (Victoria, Australia) B. Welz (Uberlingen, FRG) T. S. West (Aberdeen, UK) Atomic Spectrometry Updates Editorial Board Chairman: *M. S. Cresser (Aberdeen, UK) R. M. Barnes (Amherst, MA, USA) N. W. Barnett (Plymouth, UK) *J. Egan (London, UK) *A. A. Brown (Cambridge, UK) J. C. Burridge (Aberdeen, UK) J. B. Dawson (Leeds, UK) J. R. Dean (Norwich, UK) *L. C. Ebdon (Plymouth, UK) H. J. Ellis (Ross-on-Wye, UK) J. Fijalkowski (Warsaw, Poland) D. J . Halls (Glasgow, UK) S.J. Haswell (London, UK) *D. A. Hickman (London, UK) G. M. Hieftje (Bloomington, IN, USA) S. J. Hill (Plymouth, UK) H. Hughes (Anglesey, UK) P. N. Keliher (Villanova, PA, USA) K. Kitagawa (Nagoya, Japan) K. W. Jackson (Saskatoon, Canada) F. J. M. J. Maessen (Amsterdam, The Nether- *J. Marshall (Middlesbrough, UK) *D. L. Miles (Wallingford, UK) J. M. Mermet (Villeurbanne, France) E. Norval (Pretoria, South Africa) I . Novotny (Brno, Czechoslovakia) P. E. Paus (Oslo, Norway) P. R. Poole (Hamilton, New Zealand) T. C. Rains (Washington, DC, USA) J. M. Rooke (Leeds, UK) G. Rossi (lspra, Italy) I. RubeSka (Prague, Czechoslovakia) A. Sanz-Medel (Oviedo, Spain) *B. L. Sharp (Aberdeen, UK) W. Slavin (Norwalk, CT, USA) R. Stephens (Halifax, Canada) J. Stupar (Ljubljana, Yugoslavia) A.Taylor (Guildford, UK) M. Thompson (London, UK) J. F. Tyson (Loughborough, UK) *A. M. Ure.!Aberdeen, UK) B. Welz (Uberlingen, FRG) J. B. Willis (Victoria, Australia) *D. Littlejohn (Glasgow, UK) lands) *Members of the ASU Executive Committee Editor, JAAS: Judith Egan The Royal Society of Chemistry, Burlington House, Piccadilly, London W I V OBN, UK. Telephone 01-734 9864. Telex No. 268001 US Associate Editor, JAAS: Dr. J. M. Harnly US Department of Agriculture, Beltsville Human Nutrition Research Center, BLDG 161, BARC-EAST, Beltsville, MD 20705, USA. Telephone 301-344-2569 Advertisements: Advertisement Department, The Royal Society of Chemistry, Burlington House, Piccadilly, London W I V OBN. Telephone 01-437 8656. Telex No. 268001 Journal ofAnalytical Atomic Spectrometry (JAAS) (ISSN 0267-9477) is published eight times a year b y The Royal Society of Chemistry, Burlington House, London WIVOBN, UK.All orders accompanied with payment should be sent directly to The Royal Society of Chemistry, The Distribution Centre, Blackhorse Road, Letchworth, Herts. SG6 IHN, UK. 1987 Annual subscription rate UK f180.00, Rest of World f202.00, USA $356.00. Air freight and mailing in the USA b y Publications Expediting Inc., 200 Meacham Avenue, Elmont, NY 11003. USA Postmaster: send address changes t o Journal of Analytical Atomic Spectrometry fJAAS), Publications Expediting Inc., 200 Meacham Avenue, Elmont, NY 11003. Second class 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. 0 The Royal Society of Chemistry, 1987. 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. Information for Authors Full details of how to submit material for publication in JAASare 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, short papers, communications and letters concerned with the development and analytical application of atomic spectrometric techniques.The journal is published eight times a year, includes com- prehensive reviews of specific topics of interest to practising atomic spectroscopists and incor- porates the literature reviews which were pre- viously published in Annual Reports on Analy- tical Atomic Spectroscopy (ARAAS). Manuscripts intended for publication must describe original work related to atomic spec- trometric analysis. Papers on all aspects of the subject will be accepted, including fundamental studies, novel instrument developments and practical analytical applications. As well as AAS, AES and AFS, papers will be welcomed on atomic mass spectrometry and X-ray fluoresc- ence/emission spectrometry. Papers describing the measurement of molecular species where these relate to the characterisation 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 parti- cularly welcome. Manuscripts on other subjects of direct interest to atomic spectroscopists, including sample preparation and dissolution and analyte preconcentration procedures, as well as the statistical interpretation and use of atomic spectrometric data will also be accept- able for publication. There is no page charge. The following types of papers will be con- sidered. Full papers, describing original work. Short papers: the criteria for originality are the same as for full papers, but short papers generally report less extensive investigations or are of limited breadth of subject matter.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 Veceipt. 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 parti- cular facet of analytical atomic 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 else- where 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 spac- ing) should be addressed to: Judith Egan, Editor, JAAS The Royal Society of Chemistry, Burlington House, Piccadilly, London WIV OBN, UK Dr. J. M. Harnly US Associate Editor, JAAS US Department of Agriculture, Beltsville Human Nutrition Research Center, BLDG 161, BARC-EAST, Beltsville, MD 20705, USA or All queries relating to the presentation and submission 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 JAASEditorial Board (who may be contacted directly or via the Editorial Office) would welcome comments, suggestions and advice on general policy mat- ters concerning JAAS. Fifty reprints are supplied free of charge.Journal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates - Formerly ARAAS) JAAS Editorial Board* Chairman: L. C. Ebdon (Plymouth, UK) J. Egan (London, UK) M. S . Cresser (Aberdeen, UK) J. M. Mermet (Villeurbanne, France) D. L. Miles (Wallingford, UK) 6. L. Sharp (Aberdeen, UK) M. Thompson (London, UK) A. M. Ure (Aberdeen, UK) *The JAAS Editorial Board reports to the Analytical Editorial Board, Chairman J. D. R. Thomas (Cardiff, UK) JAAS Advisory Board F. C. kdams (Antwerp, Belgium) R.M. Barnes (Amherst, MA, USA) L. Bezur (Budapest, Hungary) R. F. Browner (Atlanta, GA, USA) S. Caroli (Rome, Italy) A. J. Curtius iRio de Janeiro, Brazil) L. de Galan (Delft, The Netherlands) J. B. Dawson (Leeds, UK) K. Dittrich (Leipzig, GDR) W. Frech (Umes, Sweden) K. Fuwa (Tokyo, Japan) A. L. Gray (Guildford, UK) S. Greenfield (Loughborough, UK) G. M. Hieftje (Bloomington, IN, USA) G. Horlick (Edmonton, Canada) B. V. L'vov (Leningrad, USSR) Ni Zhe-ming (Beijing, China) N. Omenetto (lspra, Italy) E. Pl5ko (Bratislava, Czechoslovakia) R. E. Sturgeon (Ottawa, Canada) R. Van Grieken (Antwerp, Belgium) A. Walsh,..K. B. (Victoria, Australia) B. Welz (Uberlingen, FRG) T. S. West (Aberdeen, UK) Atomic Spectrometry Updates Editorial Board Chairman: *M.S. Cresser (Aberdeen, UK) R. M. Barnes (Amherst, MA, USA) N. W. Barnett (Plymouth, UK) *J. Egan (London, UK) *A. A. Brown (Cambridge, UK) J. C. Burridge (Aberdeen, UK) J. 6. Dawson (Leeds, UK) J. R. Dean (Norwich, UK) *L. C. Ebdon (Plymouth, UK) H. J. Ellis (Rozs-on-Wye, UK) J. Fijalkowski (Warsaw, Poland) D. J. Halls (Glasgow, UK) S. J. Haswell (London, UK) *D. A. Hickman (London, UK) G. M. Hieftje (Bloomington, IN, USA) S. J. Hill (Plymouth, UK) H. Hughes (Anglesey, UK) P. N. Keliher (Villanova, PA, USA) K. Kitagawa (Nagoya, Japan) *D. Littlejohn (Glasgow, UK) K. W. Jackson (Saskatoon, Canada) F. J. M. J. Maessen (Amsterdam, The Nether- lands) *J. Marshall (Middlesbrough, UK) E. Meintjies (Pretoria, South Africa) J. M. Mermet (Villeurbanne, France) I. Novotny (Brno, Czechoslovakia) P.E. Paus (Oslo, Norway) P. R. Poole (Hamilton, New Zealand) T. C. Rains (Washington, DC, USA) J. M. Rooke (Leeds, UK) G. Rossi (lspra, Italy) I. RubeSka (Prague, Czechoslovakia) A. Sanz-Medel (Oviedo, Spain) W. Slavin (Norwalk, CT, USA) R. Stephens (Halifax, Canada) J. Stupar (Ljubljana, Yugoslavia) A. Taylor (Guildford, UK) M. Thompson (London, UK) J. F. Tyson (Loughborough, UK) *A. M. Ure.(Aberdeen, UK) 6. Welz (Uberlingen, FRG) J. 6. Willis (Victoria, Australia) *D. L. Miles (Wallingford, UK) *B. L. Sharp (Aberdeen, UK) *Members of the ASU Executive Committee Editor, JAAS: Judith Egan Assistant Editor: Harpal S. Minhas The Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN, UK. Telephone 01-734 9864. Telex No.268001 US Associate Editor, JAAS: Dr. J. M. Harnly US Department of Agriculture, Beltsville Human Nutrition Research Center, BLDG 161, BARC-EAST, Beltsville, MD 20705, USA. Telephone 301 -344-2569 Advertisements: Advertisement Department, The Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN. Telephone 01-437 8656. Telex No. 268001 Journal ofAnalytical Atomic Spectrometry (JAAS) (ISSN 0267-9477) is published eight time a year by The Royal Society of Chemistry, Burlington House, London WlVOBN, UK. All order accompanied with payment should be sent directly to The Royal Society of Chemistry, Thl Distribution Centre, Blackhorse Road, Letchworth, Herts. SG6 1 HN, UK. 1987 Annua subscription rate UK f180.00, Rest of World f202.00, USA $356.00.Air freight and mailing ii the USA by Publications Expediting Inc., 200 Meacham Avenue, Elmont, NY 11003. USA Postmaster: send address changes t o Journal of Analytical Atomic Spectromerr (JAAS), Publications Expediting Inc., 200 Meacham Avenue, Elmont, NY 11003. Second clas: postage paid at Jamaica, NY 11431. All other despatches outside the UK by Bulk Airmai within Europe, Accelerated Surface Post outside Europe. PRINTED IN THE UK. 0 The Royal Society of Chemistry, 1987. All rights reserved. No part of this publication ma) 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 permissior of the publishers. Information for Authors -ulI details of how to submit material for mblication in JAASare given in the Instructions :o Authors in Issue 1.Separate copies are wailable on request. The Journal of Analytical Atomic Spectrometry :JAAS) is an international journal for the publi- :ation of original research papers, short papers, :ommunications and letters concerned with the development and analytical application of atomic spectrometric techniques. The journal is published eight times a year, includes com- prehensive reviews of specific topics of interest to practising atomic spectroscopists and incor- porates the literature reviews which were pre- viously published in Annual Reports on Analy- tical Atomic Spectroscopy (ARAAS). Manuscripts intended for publication must describe original work related to atomic spec- trometric analysis.Papers on all aspects of the subject will be accepted, including fundamental studies, novel instrument developments and practical analytical applications. As well as AAS, AES and AFS, papers will be welcomed on atomic mass spectrometry and X-ray fluoresc- ence/emission spectrometry. Papers describing the measurement of molecular species where these relate to the characterisation 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 le.g., GC-coupled AAS and HPLC - ICP) will be parti- cularly welcome. Manuscripts on other subjects of direct interest to atomic spectroscopists, including sample preparation and dissolution and analyte preconcentration procedures, as well as the statistical interpretation and use of atomic spectrometric data will also be accept- able for publication.There is no page charge. The following types of papers will be con- sidered. Full papers, describing original work. Short papers: the criteria for originality are the same as for full papers, but short papers generally report less extensive investigations or are of limited breadth of subject matter. 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 parti- cular facet of analytical atomic 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 else- where 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 spac- ing) should be addressed to: Judith Egan, Editor, JAAS The Royal Society of Chemistry, Burlington House, Piccadilly, London WIV OBN, UK Dr. J. M. Harnly US Associate Editor, JAAS US Department of Agriculture, Beltsville Human Nutrition Research Center, BLDG 161, BARC-EAST, Beltsville, MD 20705, USA or All queries relating to the presentation and submission 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 JAASEditorial Board (who may be contacted directly or via the Editorial Office) would welcome comments, suggestions and advice on general policy mat- ters concerning JAAS. Fifty reprints are supplied free of charge.

ISSN:0267-9477    

DOI:10.1039/JA98702FX025

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

JASPEZ 2(7) 649-736 167R-210R (1987) October 1987 Journal of Analytical Atomic Spectrometry Including Atomic Spectrometry Updates CONTENTS NEWS AND VIEWS 649 Atomic Spectrometry Viewpoint-James W. McLaren 651 Conference Reports 656 Book Review 657 ASU Highlights-Barry L. Sharp 657 Conferences and Meetings 660 Papers in Future Issues PAPERS 661 681 687 695 699 705 71 1 719 723 729 733 736 Low-pressure Discharges: Fundamental and Applicative Aspects. A Review-Serg io Caroli Measurement of the Practical Resolving Power of Monochromators in Inductively Coupled Plasma Atomic Emission Spectrometry-Jean-Michel Mermet Sample Introduction Studies with a Graphite Rod Electrothermal Vaporiser for Induefively Coupled Plasma Atomic Emission Spectrometry-Susan M. Schmertmann, Stephen E.Long, Richard F. Browner Evaluation of the Grid-type Ne6uliser for the Introduction of High Dissolved Salt and High Solids Content Solutions into the Inductively Coupled Plasma-Timothy Brother- ton, Joseph Caruso Flow Injection Ion-exchange Pre-concentration for the Determination of Aluminium by Atomic Absorption Spectrometry and Inductively Coupled Plasma Atomic Emission Spectrometry-M. R. Pereiro Garcia, M. E. Diaz Garcia, Alfredo Sanz Medel Study of a Microwave-induced Plasma (Surfatron) as a Detector in Capillary-column Gas Chromatography with Reference t o Pesticides-Brigitte Riviere, Jean-Michel Mermet, Daniel Deruaz Study of Resonance and Non-resonance Atomic Fluorescence Transitions in Plasma Spectrometry-Stanley Greenfield, Karl F. M. Malcolm, Maryanne Thomsen Sorption and Atomisation of Metallic Hydrides in a Graphite Furnac-Ralph E.Sturgeon, Scott N. Willie, G. Irwin Sproule, Shier S. Berman Mechanisms of lonisation and Atomisation of Barium in Graphite Furnace Atomic Absorption Spectrometry-Etsu ro Iwamoto, S h uich i Oh ku bo, M ana bu Yamamoto, Taka hi ro K u ma mar u SHORT PAPERS Determination of Barium, Calcium, Iron, Potassium, Magnesium and Sodium in High Purity Niobium Pentoxide by Flame Atomic Absorption Spectrometry-Teresa Joanna C h ru sci hs ka Determination of Yttrium in Zirconia Matrices by Atomic Absorption Spectrometry- Azzeddine Samdi, Jacques Ptiris, Jean-Pierre Deloume, Gerard Duc ERRATUM Atomic Absorption Spectrometric Determination of the Elemental Contamination of Plant Material-Massimo Ottaviani and Paolo Magnatti ATOMIC SPECTROMETRY UPDATE 167R Atomisation and Excitation-Barry L.Sharp, Neil W. Barnett, John C. Burridge, Julian F. Tyson 199R References Typeset and printed by Black Bear Press Limited, Cambridge, EnglandJASPEZ 2(7) 649-736 167R-210R (1987) October 1987 Journal of Analytical Atomic Spectrometry Including Atomic Spectrometry Updates CONTENTS NEWS AND VIEWS 649 Atomic Spectrometry Viewpoint-James W. McLaren 651 Conference Reports 656 Book Review 657 ASU Highlights-Barry L. Sharp 657 Conferences and Meetings 660 Papers in Future Issues PAPERS 661 681 687 695 699 705 71 1 719 723 729 733 736 Low-pressure Discharges: Fundamental and Applicative Aspects. A Review-Serg io Caroli Measurement of the Practical Resolving Power of Monochromators in Inductively Coupled Plasma Atomic Emission Spectrometry-Jean-Michel Mermet Sample Introduction Studies with a Graphite Rod Electrothermal Vaporiser for Induefively Coupled Plasma Atomic Emission Spectrometry-Susan M.Schmertmann, Stephen E. Long, Richard F. Browner Evaluation of the Grid-type Ne6uliser for the Introduction of High Dissolved Salt and High Solids Content Solutions into the Inductively Coupled Plasma-Timothy Brother- ton, Joseph Caruso Flow Injection Ion-exchange Pre-concentration for the Determination of Aluminium by Atomic Absorption Spectrometry and Inductively Coupled Plasma Atomic Emission Spectrometry-M. R. Pereiro Garcia, M. E. Diaz Garcia, Alfredo Sanz Medel Study of a Microwave-induced Plasma (Surfatron) as a Detector in Capillary-column Gas Chromatography with Reference t o Pesticides-Brigitte Riviere, Jean-Michel Mermet, Daniel Deruaz Study of Resonance and Non-resonance Atomic Fluorescence Transitions in Plasma Spectrometry-Stanley Greenfield, Karl F.M. Malcolm, Maryanne Thomsen Sorption and Atomisation of Metallic Hydrides in a Graphite Furnac-Ralph E. Sturgeon, Scott N. Willie, G. Irwin Sproule, Shier S. Berman Mechanisms of lonisation and Atomisation of Barium in Graphite Furnace Atomic Absorption Spectrometry-Etsu ro Iwamoto, S h uich i Oh ku bo, M ana bu Yamamoto, Taka hi ro K u ma mar u SHORT PAPERS Determination of Barium, Calcium, Iron, Potassium, Magnesium and Sodium in High Purity Niobium Pentoxide by Flame Atomic Absorption Spectrometry-Teresa Joanna C h ru sci hs ka Determination of Yttrium in Zirconia Matrices by Atomic Absorption Spectrometry- Azzeddine Samdi, Jacques Ptiris, Jean-Pierre Deloume, Gerard Duc ERRATUM Atomic Absorption Spectrometric Determination of the Elemental Contamination of Plant Material-Massimo Ottaviani and Paolo Magnatti ATOMIC SPECTROMETRY UPDATE 167R Atomisation and Excitation-Barry L. Sharp, Neil W. Barnett, John C. Burridge, Julian F. Tyson 199R References Typeset and printed by Black Bear Press Limited, Cambridge, England

ISSN:0267-9477    

DOI:10.1039/JA98702BX027

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

1988 Winter Conference On Plasma Spectrochemis try San Diego, California, USA January 5 9 , 1988 The 1988 Winter Conference on Plasma Spectrochemistry, fifth in a series of biennial meetings sponsored by the ICP Information Newsletter, will feature developments in plasma spectrochemical analysis by inductively coupled plasma (ICP), d.c. plasma (DCP), microwave plasma (MIP) and glow and hollow-cathode discharge (GDL, HCL) sources. The meeting will convene Monday, January 4 to Saturday, January 9,1988 at the San Diego Princess resort and convention centre in San Diego. Expert short courses at introductory and advanced levels and an exhibition of spectroscopic instrumentation also will be included. ~ Programme and Objectives Symposia organised and chaired by recognised experts will include the following topics: (1) Sample introduction and transport phenomena; (2) Listrumentation and automation, including on-line analysis and remote systems; (3) Excitation mechanisms and plasma characteristics; (4) Interferometry; ( 5 ) Atomic fluorescence; (6) Glow and hollow-cathode discharges; (7) Flow injection analysis; (8) Chromatography and plasma detectors; (9) Plasma source mass spectrometry; (10) Industrial applications of ICP mass spectrometry; and (11) Sample preparation and pre-concentration techniques.Six plenary and 15 invited lectures will be presented. Three afternoon poster sessions will feature applications, automation and new instrumentation. Four panel discussions will address critical development areas. Plenary, invited and submitted papers will be published as the official conference proceedings following the meeting after peer review in Journal of Analytical Atomic Spectrometry , September 1988 issue.Instrument Exhibition A three day exhibition of spectroscopic instrumentation and chemicals , electronics, glassware, publications and software supporting plasma spectroscopy will complement the scheduled sessions. Expert Short Courses Introductory and advanced four-hour short courses will be offered January 2-3 and 9,1988. Designed to provide background and intensive training in popular topics of plasma spectrochemistry, these will cover analytical applications, instrumentation, samples introduction and various techniques (e.g., plasma diagnostics, scientific writing, chemical and physical pre-concentration and applications of isotope dilution and tracers).Registration The conference registration fee includes a copy of the conference proceedings, abstracts, a tee-shirt and conference dinner. The pre-registration fee is $275 until October 16, 1987, after which time it will be $375. On-site registration will be $400. Discounts are provided for students, and no registration fee is required for spouses. Short-course pre-registration fee $75 for each four-hour short course, after October 16 this will be $100. Further details on all aspects of the Conference can be obtained from: Dr. Ramon M. Barnes Department of Chemistry, GRC Towers, University of Massachusetts, Amherst, MA 01003-0035, USA (413) 545-22941988 Winter Conference On Plasma Spectrochemis try San Diego, California, USA January 5 9 , 1988 The 1988 Winter Conference on Plasma Spectrochemistry, fifth in a series of biennial meetings sponsored by the ICP Information Newsletter, will feature developments in plasma spectrochemical analysis by inductively coupled plasma (ICP), d.c.plasma (DCP), microwave plasma (MIP) and glow and hollow-cathode discharge (GDL, HCL) sources. The meeting will convene Monday, January 4 to Saturday, January 9,1988 at the San Diego Princess resort and convention centre in San Diego. Expert short courses at introductory and advanced levels and an exhibition of spectroscopic instrumentation also will be included. ~ Programme and Objectives Symposia organised and chaired by recognised experts will include the following topics: (1) Sample introduction and transport phenomena; (2) Listrumentation and automation, including on-line analysis and remote systems; (3) Excitation mechanisms and plasma characteristics; (4) Interferometry; ( 5 ) Atomic fluorescence; (6) Glow and hollow-cathode discharges; (7) Flow injection analysis; (8) Chromatography and plasma detectors; (9) Plasma source mass spectrometry; (10) Industrial applications of ICP mass spectrometry; and (11) Sample preparation and pre-concentration techniques.Six plenary and 15 invited lectures will be presented. Three afternoon poster sessions will feature applications, automation and new instrumentation. Four panel discussions will address critical development areas. Plenary, invited and submitted papers will be published as the official conference proceedings following the meeting after peer review in Journal of Analytical Atomic Spectrometry , September 1988 issue.Instrument Exhibition A three day exhibition of spectroscopic instrumentation and chemicals , electronics, glassware, publications and software supporting plasma spectroscopy will complement the scheduled sessions. Expert Short Courses Introductory and advanced four-hour short courses will be offered January 2-3 and 9,1988. Designed to provide background and intensive training in popular topics of plasma spectrochemistry, these will cover analytical applications, instrumentation, samples introduction and various techniques (e.g., plasma diagnostics, scientific writing, chemical and physical pre-concentration and applications of isotope dilution and tracers). Registration The conference registration fee includes a copy of the conference proceedings, abstracts, a tee-shirt and conference dinner. The pre-registration fee is $275 until October 16, 1987, after which time it will be $375. On-site registration will be $400. Discounts are provided for students, and no registration fee is required for spouses. Short-course pre-registration fee $75 for each four-hour short course, after October 16 this will be $100. Further details on all aspects of the Conference can be obtained from: Dr. Ramon M. Barnes Department of Chemistry, GRC Towers, University of Massachusetts, Amherst, MA 01003-0035, USA (413) 545-2294

ISSN:0267-9477    

DOI:10.1039/JA98702FP039

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

Ramon M. Barnes, Editor Department of Chemistry GRC Towers University of Massachuse t t 8 Amherst, MA 01003-0035 Tel. (413) 545-2294 0 bjective The lCP lnformation Newsletter is a monthly journal published by the Plasma Research Group at the University of Massachu- setts and is devoted exclusively to the rapid and impartial dissem- ination of news and literature information related to the devel- opment and applications of plasma sources for spectrochemical analysis. Background ICP stands for inductively coupled plasma discharge, which dur- ing the past decade has become the leading spectrochemical excitation source for atomic emission spectroscopy. ICP sources are also applied commercially as an atom and ion cell in atomic fluorescence spectrometry and as an ion source for mass spec- trometry.The popularity of this source and the need to collect in a single literature reference all of the pertinent data on ICP stimulated the publication of ‘the ICP lnformation Newsletter in 1975. Other plasma sources, such as microwave induced plas- mas and direct current plasma jets, have also grown in popularity and are included in the scope of the ICP lnforrnation Newsletter. scope As the only authoritative monthly journal of its type, the ICP lnformation Newsletter is read in more than 40 countries by scientists actively applying or planning to use the ICP or other types of plasma spectroscopy. For the novice in the field, the ICP lnformation Newsletter provides a concise and systema- tic source of information and background material needed for the selection of instrumentation or the development of new meth- odology.Edi todal The ICP Information Newsletter is edited by Dr. Ramon M. Barnes, Professor of Chemistry, University of Massachusetts at Amherst, with the assistance of a 20-member Board of National Correspondents composed of leading plasma spectroscopists. The Board members from around the world report news, view- points, and developments. Dr. Barnes has been conducting plasma research on ICPand other discharges since 1968. He also serves as chairman of the Winter Conferences on Plasma Spectrochemistry. Regular Featurea *Original submitted and invited research articles by ICP and plasma experts. Complete bibliography of all major ICP publications from 1961 to the present. Abstracts of all ICP papers presented at major US and interna- tional meetings.First-hand accounts of ICP developments from na- tions around the world. Special reports on microwave and other plasma progress. Calendar and advanced programs of plasma meetings. Publication of plasma-related patents. Technical translations and reprints of critical foreign- Critical reviews of plasma-related books. language ICP papers. Conference Activities The lCP lnforrnation Newsletter has sponsored five international meetings on developments in atomic plasma spectrochemical analysis since 1980 in San Juan, Orlando, San Diego, Leysin, Switzerland, and Kailua-Kona, HI. Meeting proceedings have ap- peared as Developments in Atomic Plasma Spectrochemical Analy- sis (Wi ley), Plasma Spectrochemistry and Plasma Spectrochemistry II (Pergamon Press) as well as in special issues of Spectrochimica Acta, Part B and Journal of Analytical Atomic Spectrometry.Subscription Information Subscriptions are available for 12 issues on either an annual or volume basis. The first issue of each volume begins in June and the last issue is published in May. For example, Volume 12 runs from June 1986 through May 1987. Back issues beginning with Volume 1, May 1975 are also available. To begin a subscription, complete the attached order form, and submit it with prepayment or purchase in- formation. For additional information please call (41 3) 545-2294 or contact the Editor. Detach and send to: ICP Information Newdetter, Dr. Ramon M. Barnes Department of Chemistry, GRC Towers, University of Massachusetts, Amherst, MA 01 003-0035 Telephone (41 3) 545-2294 Start a subscription for the following issues (complete): [ ] Vofume(s) - (June 198-- May 198-) or [ 1 198- (January-December) I enclose: [ ] prepayment or [ ] purchase order (No.1 or [ ] Send invoice. Current subscription rates are $49 (North America), $69 (Europe, South America), or $75 (Africa, Asia, Indian/Pacific Ocean Areas, Middle East, and USSR). Back issues rates available on request. Circle OO6for further informationJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY For further information about any of the products featured in the advertisements in this issue, please write the appropriate number in one of the boxes below. Postage paid if posted in the British Isles but overseas readers must affix a stamp.OCT'87 READER ENQUIRY SERVICE I 1 PLEASE USE BLOCK CAPITALS LEAVING A SPACE BETWEEN WORDS Valid 12 months iI-I_u_1_1z_l-l I I r - i I I I I 1 i r - m i 7-lTI:m LULI I 1 I 1 -IIITTTI I 1 I I I I I I I I I I I i IIE 4 TOWN L I l I l I I I I - L L m - T m I POST LODE ~- IIlililIiIIl - __ I l l - ; i T 7 7 1 ' 1 I i - i rn TlT I \ I Tn I CTI I I I I m T I I In I I I 1 i I I f 1 1 7 7 i 1 i I I I I I I i / I 2 COMPANY PLEASE GIVE YOUR BUSINESS ADDRESS IF POSSIBLE. IF NOT, PLEASE TICK HERE rJ - _ -_ 3 STREET I I I I T I i I I r i I I I I I I I I -~ 1 1 I 5 COUNTY -_ 6 COUNTRY 7 DEPARTMENT DIVISION l i I I I I I i _- 11-11-1 I i i 1 1 I I 8 YOUR JOB TITLE! POSITION 9 TELEPHONE NO m m m - 1 OFFICE USE ONLY HFC D PROC 0 L U = J FOLD HERE I Postage will be paid by Licensee Do not affix Postage Stamps if posted in Gt. Britain, Channel Islands, N. Ireland or the Isle of Man BUSINESS REPLY SERVICE Licence No. WD 106 Reader Enquiry Service Journal of Analytical Atomic Spectrometry The Royal Society of Chemistry Burlington House, Piccadilly LONDON WIE 6WF England I I t I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I \ I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I

ISSN:0267-9477    

DOI:10.1039/JA98702BP041

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 167R ATOMIC SPECTROMETRY UPDATE-ATOMISATION AND Barry L. Sharp* Macaula y Land Use Research Institute, Craigiebuckler, Aberdeen AB9 2QJ, UK Neil W. Barnett Department of Environmental Sciences, Plymouth Polytechnic, Drake Circus, Plymouth, Devon PL4 8AA, UK John C. Burridge Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen A69 ZQJ, UK Julian F. Tyson Department of Chemistry, University of Technology, Loughborough, Leicestershire LE 1 1 3TU, UK EXCITATION Summary of Contents 1 Arcs, Sparks, Lasers and Low-pressure Discharges 1.1. Arcs 1.2. Sparks 1.3. Lasers 1.4. Low-pressure Discharges 1.4.1, Glow discharge lamps 1.4.2. Hollow-cathode discharges 1.4.3. Other sources 2 Plasmas 2.1. Inductively Coupled Plasmas 2.1 .I.Plasma characteristics 2.1.2. Sample introduction 2.1.3. Flow injection and chromatography 2.1.4. Chemometrics 2.1.5. Instrumentation 2.1.6. Inductively coupled plasma mass spectrometry (ICP-MS) 2.1.7. Inductively coupled plasma atomic fluorescence spectrometry 2.2. Microwave-excited Plasmas 2.2.1. Fundamental studies 2.2.2. Instrumentation 2.2.3. Sample introduction 2.2.4. Chromatography 2.3. Direct Current Plasmas 3 Flames 3.1, Fundamental Studies 3.2. Interference Studies 3.3. Instrumentation 3.4. Chemometrics 3.5. Sample Introduction 3.5.1. Nebulisers and spray chambers 3.5.2. Atom-trapping techniques 3.5.3. Flow injection techniques 3.5.4. Chromatographic detection 3.6.1. Laser-excited atomic fluorescence spectrometry (LAFS) 3.6.2. Laser-enhanced ionisation (LEI) 3.6.3.Other studies 3.6. Applications of Lasers 4 Electrothermal Atomisation 4.1, Atomiser Design 4.2. Atomisation Surface 4.3. Sample Introduction 4.4. Fundamental Processes 4.5. Interference Studies 4.6. Developments in Technique 5 Chemical Vapour Generation 5.1. Hydride Generation 5.2. Mercury and Other Elements c P-, FS 1 * Review Topic Co-ordinator, to whom correspondence should be addressed.168R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 This, the second annual review on atomisation and excitation, continues our policy of offering a regular distillation of the literature on analytical atomic spectrometry with the aim of highlighting those developments which have, or potentially will make, a significant contribution to our understanding of the fundamental processes.By reporting material from both conference presentations and published papers, it is hoped to provide readers with the most up-to-date information possible. At the same time, the accumulation of these reviews together with information published in the Annual Reports on Analytical Atomic Spectroscopy provides a unique historical record of developments in this field. Further reviews covering atomisation and excitation processes and related topics may be found in the following references: 86/1813, 86/1960, 86/1961, 86/1962, 87/23, 87/108, 87/109, 87/663, 87/666. A major biennial review of emission spectrometry, by Keliher et al. (86/1961), has been published within the period of this ASU. Although the 1984-1985 material reviewed has already been considered (in ARAAS, 1985, 14 and JAAS, 1986, 1), their complementary viewpoint is strongly recommended to all spectrochemists.A total of nearly 700 references was cited, about one-third of them dealing with excitation sources. Two theoretical developments will also arouse widespread interest and perhaps even some controversy. On the one hand, Scheeline (860819) has discussed some implications of the apparent relation between the number of lines of a given intensity and their intensity relative to the most intense spectrum lines. On the other hand, Thelin and Yngstrom (87/287) and Thelin (87/365) have presented evidence for a new formula for spectral line intensities. Both of these topics are complex and require a careful study of the detailed publications.1.1. Arcs Apart from a short review of .arcs as radiation sources by Fijalkowski (87/664), with 39 references, and a conference discussion by Pavlovic (871C1140) of recent research with arcs, the only topic of general theoretical interest noted was a discussion by Portuondo et al. (87/C1024) of the criteria to be used for the selection of internal standards. They investigated the behaviour of 32 atomic line combinations, using Al, Cu, Fe and Mg as analytical elements and In, Ni and Pd as reference elements. They concluded that their observations could be satisfactorily explained by a theoretical model. The versatility of arc methods for trace element analysis has again been demonstrated by the variety of the reports noted in this review period.Most of these reports were concerned with biological or with geological samples. However, Wang and Zhou (86/2021) successfully applied a low-current arc with silver chloride as carrier to determine Cu, Fe, Mo, Ni and Si as trace impurities in a magnesium - yttrium alloy. Biological materials studied included human hair (86/1798), rat brain tissue (87/C1031) and liver, ovary and muscle of crab (86/1683). The authors of this last report, which noted inter alia that abnormal reproductive function was accompanied by an elevated Cd level in the liver, concluded that the colour of the liver of female crabs was a sufficient discriminator between healthy and unhealthy animals. Sic gloria AES! Reports dealing with geological samples included several that may be noted without comment (87/7, 87/685, 871944, 87/C1027, 87/C1030) and one, by Barton (87/393), that is a useful reminder that visual comparisons of photographically recor- ded spectra can yield good analytical results.By the u_se of gallium oxide as carrier, he obtained detection limits of ca. 0.1 p.p.m. for Ag, Bi and Sn, ca. 1 p.p.m. for Cd, Cu, Pb and Zn, 5 p.p.rn. for Sb and 20 p.p.rn. for As in stream sediments and in the non-magnetic fraction of their heavy mineral concen- trates. An unusual and geochemically very interesting applica- tion of d.c. arc AES was the determination of trace elements, including Au, in liquid inclusion samples in quartz by Tan and Shen (87/1296). They obtained the samples by thermal cracking and ultrasonic collection on a carbon disc.Their measurement technique gave detection limits in the range 0.1-10 ng. Arc methods often include a pre-concentration procedure to enhance their sensitivity and the techniques noted in this review year have been typical. Matrix removal, for example, was used to determine trace impurities in lead telluride (87/269) and in germanium oxide (87/609). Sorption processes were also reported: for the determination of Ag, Cu and Pd in aqueous solutions, using a glycerol methacrylate gel having SHgroups (86/1745); for Cd, Ga and Pb in waste waters, using mercaptoacetoxycellulose (87/337); and for the platinum group metals in ultrabasic rocks, using activated carbon after conversion into sulphides with thiourea (871605). Detection limits for all of these procedures was of the order of 0.01 p.p.m.Selective coprecipitation, using 8-hydroxyquinoline, was applied to the determination of A1 in soil extracts (86/1887). No remarkable advances in arc techniques were noted among recent reports. Gilbert and co-workers have described automated devices for the analysis of viscous fluids, such as lubricating oils. The first used a 2.5 mm diameter filament made from braided graphite fibres (86/C1518), and the second employed a multiple graphite rotrode (86/C1520, 87/CS58) to introduce samples to the arc plasma. The combination of a microarc atomiser with a helium capillary arc was shown to be a simple and effective means for analysing microlitre volumes by AES (86/C1600). The small size and easy operation at atmospheric pressure were cited as attractive features of the source.The use of light guides to couple several emission sources to a single spectrometer (87/426) and the resurrection of Harvey’s semi-quantitative method for spectrographic analysis (87/C1025), some 40 years after his book was published, are not expected to excite many spectrochemists. Linear charge-coupled photodiode arrays are not yet widely used for metal analysis. The report by Suranov et al. (86/1701) on the use of such an array in an automated apparatus for the analysis of nickel-based alloys and high-purity manganese, will not encourage other workers, who may well find errors of up to 10% to be unacceptably high. Despite a long history of detailed investigations into the effects of the alkali metals, alkaline earths, halides and sulphur on the analytical performance of arcs, “new” observa- tions are reported every year.Unfortunately, the reviewer of this year’s reports on buffers and matrix effects was unable to identify any new conclusions having a general validity. Interest in most of the reports is therefore likely to be restricted to analysts faced with problems specifically similar to those described. For this reason, attention is simply drawn to the materials studied: Cu, Ni, Ti and V in coke (86‘1723); graphite and yttrium oxide (86/1878); Mo, Ti, W and Zr in nickel oxide (87/394); Mo in alumina (87/631); synthetic human brain ash (87/957); REEs in carbon (87/99) and in steelJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 169R (87/604). Other buffedmatrix reports described a radiation intensity enhancement obtained with Cd or Zn added at 150 mg g-1 (86/1713), a decreasing trend of line intensity in the series of sodium halide buffers from the fluoride to the iodide (87/927), and the possible use of the concept of an effective matrix ionisation potential for geological samples (87/1197).Reactions of REEs with Co, Cu, Mo, Ni, Ta or Ti electrodes were also discussed (87/C1026, 87/C1029). 1.2. Sparks Several general discussions concerning the multi-element analysis of metals by AES have appeared in the past year. In a review with 37 references, Strasheim (87/671) dealt mainly with spark and d.c. arc techniques, while Morozov et al. (87/418), in a Russian report with 47 references, reviewed the topic of automated systems of analysis for metals and alloys.In order to counter the latent view that a high-voltage spark is an undesirable emission source, Cousins et al. (87/C814) used temporally and spatially resolved signals to demonstrate that sparks contain much better information than is generally appreciated. Unfortunately, unless customers show a keen interest in more sophisticated measurements, and are pre- pared to pay for them, they are unlikely to become widely available. Setting-up and calibration procedures tend to be instrument orientated. Nevertheless, the report by the Standards Asso- ciation of Australia (87/1176), which contains recommenda- tions for calibration and standardisation procedures, as well as for checking optical alignment and spectral line profiling, should prove to be of wide interest.Two general assessments of analytical performance based on round-robin tests have been reported. The first, by Haftka and Mannweiler (86/1825), was concerned with the determination of trace elements in pure aluminium; in the second, Aubrey and Monroe (87/606), discussed results of general steel analysis. The evaluation of the aluminium analyses disclosed consider- able differences in performance among the group of 36 co-operating laboratories. Reports noted in the past year reflect a steady evolution of analytical procedures and no advances have appeared that could be classed as “quantum leaps.” Further evidence has been provided, for instance, that portable emission spec- trometers are very valuable for quality control in steel production (87/93).The role of the counter electrode in the analysis of copper was discussed by Piatek (87/C1033) who concluded that a carbon rod of 6 mm diameter was better than any other counter-electrode of 3, 6 or 10 mm diameter made from cadmium, carbon, copper, magnesium, silver or zinc. A comparison of flat and dimple samples (see JAAS, 1986, 1 , 123R) has been reported in detail by Strasheim and Bohmer (87/129) for the analysis of low-alloy steels. Spark microanaly- sis is still attracting some limited attention (87/C769,87/C794), but probably deserves more. Aerosol generation has been used for the continuous analysis of molten steel (87/1213) and for coal fly ash (87/C720), in both instances employing excitation sources separated from the sampling process. Aerosols obtained by the spark ablation of metals have been discussed by two groups of researchers.Lovik et al. (87/C816) were concerned with the condensation of analyte within the spark plasma, and with the effect this has on the over-all analytical performance. They used LAFS to probe the pathways of the analyte from atomic species to condensed particulates and observed that the particulates were at least indirectly linked to the spark sampling processes. Raeymaekers et al. (87/C1048), on the other hand, investigated the size, shape and composition of individual particles. An important observation was that particles generated by the spark ablation of a super-eutectic aluminium - silicon alloy under an Ar atmosphere showed a significant elemental redistribution, whereas vacuum sparked particles did not.1.3. Lasers This year there are only a few laser topics that are appropriate to this section of the review. Other aspects are considered elsewhere, especially in section 3.6. Apart from the paper by Kunze (86/1656), in which the problem of making experi- mental checks on LTE in discharges is discussed, the other reports are all concerned with practical analytical problems rather than with the underlying processes. Kunze proposed, on theoretical grounds, that laser-induced fluorescence pro- vided a much simpler method for checking LTE than did the conventional method which entails a knowledge of transition probabilities and plasma temperature. Provided that energy levels can be saturated by strong pumping, the relative change of intensity of only one emission line and a knowledge of the electron temperature are the only parameters needed to check for LTE.An experimental confirmation of Kunze’s proposal is obviously needed. Dorofeev (87/975) has discussed how the selectivity and sensitivity of AES, AAS and AFS can all be improved by the use of high-power tunable lasers. Laser microprobes used for analysis are now generally used in conjunction with other forms of excitation. The reports by Rudnevskii et al. (86/2023), who used a d.c. arc to analyse laser-ablated material deposited on graphite discs, and by Georgieva et al. (87/C1004), who passed laser-ablated material into an ICP torch, are typical of such analyses. Direct laser microprobe AES, however, was found by Marczewski and Mierzwa (87/C1003) to agree well with XRF analyses for Pb, Sn and Zn in a study of ancient bronze and jewellery.Mass anaIysis using a time-of flight spectrometer has also been shown to be a versatile way of examining material ablated by a laser (87/C1147). Lasers can be very effectively combined with low-pressure discharges. Pate1 and Winefordner (87/124), for instance, used a frequency-doubled laser to excite non-resonance fluores- cence of the In 303.94-nm line, the atomisation being performed in a GDL with either a copper or a graphite cathode. A detection limit of about 10 ng in a lo-@ sample was achieved. The interesting use of a laser to monitor a chemical vapour deposition (CVD) process was reported by Tong and Shaw (87/36).Direct current glow discharge decomposition of 10% silane in helium was used to prepare thin films of hydrogenated amorphous silicon. The presence of a transient molecular intermediate (SiH) was monitored by means of an optogalvanic technique. Their procedure effectively com- plements other spectrometric methods for studying CVD plasmas. A new imaging system was reported by Huie and Yeung (87/653) for obtaining spatially and temporally resolved AA profiles of transient events. They used an acousto-optic beam deflector to scan a laser probe beam repeatedly in one dimension across the region of interest. They studied atom formation in a laser-generated plume above a sodium tung- state surface. Earlier related work has been published by the same authors (86/1398).1.4. Low-pressure Discharges 1.4.1. Glow discharge lamps Glow discharge lamp spectrometry (GDLS) has now matured into a widely accepted technique, especially for the analysis of metals. The comprehensive review of the state-of-the-art of GDLS given by Broekaert (87K1323, JAAS, 1987, 2, 537), was therefore timely. VandenBussche and Thijssen (87/C1395) have also evaluated GDLS, commenting on the increased linearity of working curves compared with those in other AES techniques and on the reduction in the range of different calibration curves needed to cover widely different matrices. More narrowly, in a review with 48 references, Pavlovic (86/1681) has compared GDLs and HCLs as excita- tion sources for the automatic analysis of metals. Using data170R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 obtained with geological samples, a type of material with notoriously variable matrices, Brenner (87/C1394) concluded that GDLS was preferable to slurry-injection ICP-AES because the latter was more affected by the mineralogy of the samples. Lamp characterisation still attracts some research and lasers, used either to excite fluorescence or to enhance ionisation, play an important part in such studies. Laser- excited AFS, for example, was used by Pate1 and Winefordner (86/C1495) to examine GDL characteristics and the same workers used this technique to identify Cu2, CuO and Pb2 species in sputtered vapours (87/512). On the other hand, laser-enhanced ionisation, in conjunction with quadrupole MS, was used by Hess and Harrison (87/58) to gain new insights into GDL discharge processes, the high selectivity of the MS detector being seen by these authors as its most valuable feature.Charge transfer excitation for the Cu I1 224.7-nm line has now been demonstrated by Fielding and Steers (87/C152) in an Ar - Cu system, following earlier work with Ne - Cu systems. Effects of an external magnetic field on the sampling and radiative properties of an abnormal glow discharge have also been recently investigated by other workers (87/C797). Some very interesting results were repor- ted by Piepmeier and co-workers (871C798, 87/C799) who used AFS and AAS to study the effect of agas jet impinging on the sample surface in a GDL. A dramatic increase of sputtering rate was obtained which enhanced the atomic absorption by a factor of 40.A full description of their device is eagerly awaited. Instrument manufacturers have continued to advocate GDL-MS (87/C189, 87/C824, 87/C1396) as an analytical technique with a very wide dynamic range, and that is not seriously subject to matrix effects. There has been a conspicu- ous lack of research reported by independent users of this system. The application of AES still seems to be preferred, for instance, for metal analysis as in the studies of sputtering of silver-copper alloys (87/55) and to determine W in iron - tungsten binary alloys (87/1446). The usefulness of GDL-AES for complex alloyed steels, especially if a “sum to 100%” procedure is applied, has also been described by an instrument manufacturer (86/C1504). A single calibration curve for each of 22 elements, including C, Cr, Mo, Ni and V was claimed to be satisfactory.The value of GDLS for surface analysis and for depth profiling has again been demonstrated in a number of reports. Coated steels, for example, were examined by Goulter et al. (861C1496) and their data indicated that the GDL mechanism was predominantly non-thermal. They made the important point that the data aquisition system must satisfy constraints imposed both by the speed of analysis and by the required depth resolution. Good computer graphic display was essen- tial if the data were to be fully utilised. Depth profiling of Ni- and Zn-coated steels by GDLS was found by Iwai et al. (8711244) to yield results that agreed well with those obtained by AAS.Theoretical considerations underlying quantitative surface analysis were discussed by Bengston and Lundholm (87/C1397) and also by Channessian et al. (87/C1398). A report that has considerable significance for the analysis of samples prepared by pelleting powders has appeared. In it, Mai and Scholze (87/619) discuss the pronounced diffusional transport towards the surface that can occur along structural short-circuits between grains. Material from the bulk of a sample can thus have a marked effect on the sputtered surface. 1.4.2. Hollow-cathode discharges The analytical characteristics of HCLs have been investigated so exhaustively in recent years that this topic is apparently now generating very little novel research activity. The review by Caroli (87/589), with 44 references, as well as a conference discussion by the same worker (87/C1145), clearly demon- strate why these low-pressure excitation sources have proved to be so beneficial for AAS, AES and AFS.Fundamental studies have been limited to the discussion by Steers and Zendehnam (87/C193) of the modelling of one-step and two-step excitation processes in the positive column of Ar, Ne and Ar - Ne discharges. The hollow-cathode plume configuration (see JAAS, 1986, 1,124R) continues to be explored only by the original group of researchers. King and Harrison (871C800) have compared it with a coaxial cathode discharge as an ion-source for MS. Although the plume showed a better energy discrimination between sputtered species and molecular interferents, the coaxial discharge gave the better sensitivity.Marcus and Harrison (86/C1498, 86/1821, 87/C796) have given further examples of the usefulness of the plume discharge for elemental determinations, e.g., for Co and Mo in automobile exhaust catalysts. The normally configured HCL, generally in a demountable form, has been applied to a variety of analytical problems, ranging from the microanalysis of renal tissue samples for Ca, K and Na (87/C770) to the analysis of REE solutions (87/C1054). Comparisons of Ar or He as fill-gas (87iC1056) and of d.c. or h.f. excitation (87/C1057) have been made. On the basis of an internal standardisation procedure, involving a summation to 100°/~, De Marco et al. (87/131) claimed to determine Cu and Zn in brass, and Cr, Fe and Ni in stainless steel with an accuracy comparable to that obtainable with an ICP.1.4.3. Other sources The reports noted this year have been mainly concerned with the vaporisation of thin metal films or with metastable energy levels in gases. Only three other topics merit attention. Firstly, the ring discharge used by Wrembel to determine Hg, mentioned in last year’s review (see JAAS, l986,1,125R), has been described in full (87/76) and its application to matrices such as water and air, from which Hg can be pre-concentrated by, e.g., freeze-drying, electro-deposition or amalgamation on gold, has been discussed (87/C981). Secondly, molecular absorption spectrometry (MAS) , using gaseous monohalides (for instance AlX, InX, GaX) generated in an electrothermal graphite furnace, has been proposed as a sensitive method for determining trace levels of the halogens (87/C1142) as an alternative to the use of their emission resonance lines, for which relatively high excitation energies are required.Thirdly, the theta-pinch studies by Scheeline and co-workers (86/1822,86/1823,87/C753) have again confirmed the need for time-resolved measurements to remove the limitations imposed by the high background emission from plasmas generated in such sources. Of these three techniques, only the ring discharge seems at present likely to find any general application. Over the years, the electrical vaporisation of thin metalfilms has generated a large number of interesting research papers, but these have unfortunately not yet led to any general adoption of the technique for routine analysis.Information published in the past year will not alter this situation. For instance, Goldberg and co-workers (86/C1503, 87E7.54, 87/1259, 87/1260) reported that imploding films with an axial current (a zeta-pinch) produced such a poor SBR that normal AES measurements are inadequate, and that further time- resolved studies of the post-discharge environment were needed. Elsewhere, Sacks, Albers and their associates recently explored the effects of a magnetic field on the plasma formed by a vaporised metal film (86/1665, 87/118, 87/C755). Spatial drifts attributed to the E X B interaction were found to influence the analyte - substrate interaction as well as the SBR. Profound effects on the radiative properties of the transient discharge were obtained with field strengths of only a few kilogauss.Metastable energy levels in gases have played several distinct roles in the reports covered by this review period. On the oneJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 171R hand, the well known transfer of energy from a metastable level to excite atomic emission for elemental analysis has again been described. Thus, active nitrogen was used by Takayama et al. (86/1921) to investigate anion interferences in the determination of Cd, Hg and Zn vaporised from a tantalum boat, while Michel and McCaffrey (87/C556) compared the AE sensitivity of spectra excited by active nitrogen with continuum-light source AF, employing samples vaporised from a carbon furnace. They reported much better sensitivity by AE than by AF.Also with an analytical objective, the afterglow region of an atmospheric pressure helium discharge has been developed as a GC detector for halogens and other non-metals (86/1870, 87/C801). This required close coupling of the discharge and the spectrometer so that lines in the vacuum UV could be used. On the other hand, two interesting papers have been published which are not concerned with elemental analysis. In the first, the chemical reactivity of active nitrogen was applied by Wittman and Mitchell (86/ 1835) to the removal of hydrocarbons from nitrogen. The combination of an oxygen-scavenging resin, a cold trap and a microwave discharge reduced the carbon level in the nitrogen from 20 to 0.4 p.p.m. In the second paper, an air afterglow containing defined concentrations of NO and O(3P) was used by Coxon and Roychowdhury (86/1837) to calibrate a german- ium detector at 1270 nm for determining the absolute concentration of metastable 0 2 ( a ’ A ) .Their experiments estab- lished a linear dependence of emission at 1270 nm on the number density of metastable 02(a’A) molecules. This finding will enable these metastable molecules to be determined in a number of chemical reactions in a simpler way than hitherto. 2. PLASMAS 2.1. Inductively Coupled Plasmas The inductively coupled plasma with both optical and mass spectrometric detection has continued to attract a large research and development effort from analytical scientists. There has been steady progress on understanding the fun- damental discharge processes , but sample introduction, che- mometrics and coupling with separation techniques have been the growth areas.The air plasma is increasingly being used in the process control environment and Ar - N2 cooled plasmas have been reported to offer the best over-all analytical performance. Inductively coupled plasma mass spectrometry continues to enjoy the status of the technique most used to impress the uninitiated. In contrast, the solid advances made in atomic fluorescence detection using the dual plasma technique have not yet attracted a wide user base. 2.1.1. Plasma characteristics Thermodynamic and gas dynamic studies of plasmas provide a macroscopic view of plasma operation and are particularly appropriate for elucidating particle vaporisation (87/C220), energy balance (87/C1143) and transport mechanisms.Tang and Trassy (86/2012) have now published their findings on the role of water in determining axial temperature distribution and concluded that the temperature in the pre-heating zone is controlled by the vaporisation of water, but the subsequent rise in temperature is governed by the higher energy require- ments of the dissociation process. The resultant release of H atoms, which have a thermal conductivity ten times higher than those of Ar, then dominates the transfer of energy to the analyte. This was demonstrated by comparison of excitation temperatures with and without desolvation and with the addition of gaseous H2. Browner and Long (87/595) compared vertical spatial emission profiles for atom and ion lines derived from electrothermal and nebulisation sample introduction. The results support the work of Tang and Trassy, showing a substantial (10 mm) upward shift in the profile when the analyte was introduced as a liquid aerosol.On this theme, a stochastic model for analyte desolvation/dissociation and excitation has been discussed by Li and Dowling (87/C782). The use of sinusoidally modulated power input and pulse- interrupted excitation provide diagnostic tools for studying energy transport in the plasma. Using the former technique, Hieftje and co-workers (86K1506, 8611836) found that the maximum excitation temperature correlated with the peak of the power waveform whereas species number density peaked at the trough of the power waveform.In each instance, there was a delay between the maximum and minimum in the waveform and in the observed effect which was independent of species and frequency, but dependent on observation height, indicating a link to the rate of vertical transport. Apparently in contradiction to this, Olesik et al. (87/C694, 87/C780) observed a more rapid emission response from Ca I than from Ca 11. Compared with the millisecond delay times observed for analyte species responses, Farnsworth (86/1782, 87/C776) noted Ar emission decay times of 150-185 ps from a decaying plasma. Excitation mechanisms in the ICP have been extensively studied and each year there are signs that agreement on the important processes is emerging; however this consensus remains elusive. Such difficulties might be anticipated for a source as complex as the ICP, but they are greatly exacerbated by variations in the equipment (87/1469) and operating conditions used by different research groups.The move towards a “standard torch” for fundamental studies, as reported last year (JAAS, 1986, 1, 134R) must therefore be enthusiastically anticipated. Hasegawa and Haraguchi (87/1) have applied the collisional - radiative model, including radia- tion trapping and transport phenomena, to the analytical Ar TCP. The model yielded “close to LTE” population densities as previously discussed by Blades (86/1896) with the over- population of the lower states of Ar, caused by spontaneous emission, being partially offset by radiation trapping. Trans- port effects in the normal analytical zone were considered to be insignificant, but not in the region about 5 mm above the load coil where there is a large inflow of electrons and ions by ambipolar diffusion, which reduces Ar+ density causing the plasma to be in a state of net recombination.Lovett (86/C1500) suggested that the off-axis peaking of analyte ionic emission in this region, and perhaps within the coil region, could be accounted for by recombination - cascading of doubly ionised analyte atoms created in the channel boundary. He further suggested that the higher ground-state ionic popula- tion observed in the channel axis is derived from radiative excitation, from the plasma core, of neutral Ar to Ar metastable and pseudo-metastable states and subsequent Penning ionisation of the analyte atoms.These analyte ions are then largely conserved until they enter the analytical zone where the electron density is much higher. Blades and co-workers (86/C1509, 87/617, 87/C774) determined level172R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 populations of Fe I and Fe I1 and, using Boltzmann - Saha plots, demonstrated the over-population of low lying analyte atomic states, an equilibrium between the high level atomic states and ground ionic state and a compensating under- population of the higher ionic states. These workers attributed these observations to the existence of a collisional - recombi- nation equilibrium with the electrons (i.e., partial LTE model) and concluded that spontaneous emission is sufficient to account for the excess populations of the low lying atomic states.It was not considered that the curvature of the Boltzmann plots was evidence for charge-transfer excitation which is the interpretation advocated by Mermet and co- workers (87/598, 87/C1151 , 87/C1370, 87/C1371 , 87/C1372) and Tang et al. (87/C1370). These workers used gas sheathing of the sample aerosol flow to control the charge transfer process independently of the excitation potential. Rayson and Hieftje (87/596) have now published the results of their steady-state approach (see JAAS, 1986, 1, 126R) to the evaiuation of plasma excitation mechanisms and have pro- vided further evidence for an electron dominated equilibrium by showing that Ca atomic emission appears to occur primarily through three-body and radiative Ca+ recombination and excitation of Ca+ through direct electron impact.Identifying a direct benefit to the analyst of these kinds of studies is not always easy, but it has been suggested (87/959,87/C1326) that they could lead to simulated spectra being produced to supplement the experimental spectral atlases currently avail- able. The mechanism of easily ionisable element (EIE) interfer- ences in the ICP remains unclear. Koirtyohaan et al. (86/1895, see also 87/C777) have now published their findings on EIE effects low in the plasma. They noted that emission enhance- ments for specific transitions correlated with published electron impact cross-sections and attributed the effect to local increases in electron density coupled with assisted ambipolar diffusion from the plasma annulus.The particularly high impact cross-sections of EIE transitions for low-energy electrons was also noted by Tang et al. (87/C1372). An atomic fluorescence study of ground state Ca I and Ca I1 revealed that the influence of EIEs was minimised by conditions favouring high electron density in the central channel, i.e., low injector flow and higher power (87/133). The spatial and parametric variations of the interference effect were considered too complex to be adequately accounted for by a single mechan- ism. Plasma diagnostics, for the purpose of this review, is considered to encompass work primarily aimed at establishing new methodologies for determining plasma parameters, for example, the measurement of temperature and electron density.Houk (87/2) has commented upon the difficulties of making excitation temperature measurements in the absence of accurate transition probabilities (see also 86/1656). A method was therefore proposed in which the temperature of a reference source is first determined and then the test source substituted and temperatures determined on a relative basis. Such relative temperatures might prove useful in spatial and parametric studies, where absolute accuracy is not essential. Methods for calculating electron Stark widths of atomic lines have been evaluated by Marasinghe and Lovett (87/115). Whilst the four methods considered provided estimates to the same order of magnitude, the best was found to depend on the properties of the excited state. A computerised system for obtaining Abel-corrected Stark profiles of the HP line has been described by Walters et al.(87/65). The use of a water- cooled sampling probe for studying VUV radiation from the plasma has again been reported (87/C781, 87/C791, see also JAAS, 1986, 1, 127R). The Ar resonance lines at 104.8 and 106.6 nm were observed and found to be self-absorbed which the authors took as evidence for the occurrence of radiation trapping. Calculation of AFS curves of growth has indicated that the point where departure from linearity occurs may be used to estimate absolute number densities without know- ledge of the optical and geometric parameters (871C830). Similarly, Ar metastable number densities have been deter- mined from growth curves produced by continuum-source AAS yielding values of 2.3 X 1010-7.4 X 1011 cm-3 (87/1472).Gillson and Horlick (87/121) preferred conventional line- source AA for determining the distribution of ground-state atoms and ions of Ca, Cd and Mg. The data indicated the presence of large populations of ground-state ions for all these elements even at powers below 1 kW. A description of the sample pair modulation technique for studying molecular fragmentation in the plasma, first reported last year (JAAS, 1986, 1, 127R), has now been published (86/1626). Fourier transform spectroscopy (FTS) has proved to be a powerful tool for plasma diagnostics (87/C151 , 87/C1328), but its high cost and the so-called multiplex disadvantage has limited its application for analytical studies. The current state of FTS has been reviewed by Miyazaki (87/510) and by Faires (87/667).Progress continues to be reported in the design of instruments of moderate resolving power (106) appropriate for analytical application, but a packaged system has yet to appear on the market. For example, Routh et al. (87/C559, 86/C1523 , 86/C1552, 87/C560, 87/C1336) have discussed the influence of optical , mechanical , transform processing and source-noise characteristics on performance and have given analytical data for their prototype spectrometer (see also 87/C149, 87/C1349). A commercially available Fourier trans- form spectrometer , incorporating dynamic alignment capabil- ity, normally used for IR spectroscopy, has been shown to have the necessary stability and optical quality for UV application (86/C1510).The Achilles heel of FTS for analy- tical application is the multiplex disadvantage, the name given to the process by which temporal fluctuations (noise) in strong spectral features are transformed to spectral components (side bands) and base-line noise in the wavelength domain. Marra and Horlick (871648) studied noise processes and concluded that at low concentrations, the limiting factor is background photon noise whereas source flicker limits the attainable SNR at high analyte concentrations, a similar situation to that found in dispersive spectrometry. A study of the effects of matrix elements on detection limits for Ni showed increases of 122- and 5-fold for 1000 pg ml-1 solutions of Ca and Al, respectively (86/1792). The multiplex disadvantage can be reduced by band pass limitation or reduction in the source noise (871C792).In this connection, Snook (87/C153) and Davies (87K175) have continued their studies of axial viewing and laminar flow torches and by combining the two have claimed substantial reductions in noise power. A medium- resolution (0.25 cm-l) Fourier transform spectrometer has been used to characterise the red and near-IR emission spectra of Br, C, C1, N, 0 and S (87/32). The construction of three-dimensional intensity distributions from two-dimensional integrated intensities has convention- ally relied upon the use of Abel transformation; however, it is well known that noise and source asymmetry adversely affect the accuracy. For these reasons, Hieftje and co-workers (86/C1513,86/C1514,87/C789) have investigated the potential of computerised tomography (CT) for spatial mapping.Because of the large number of angular projections required to construct the image, the plasma was mounted on a Z-theta translation stage and data collected with a silicon intensified target (SIT) vidicon detector. As expected, the data produced were similar to those obtained by Abel transformation for the axi-symmetric ICP, but CT showed advantages for asym- metric atom reservoirs. The same group have described a more conventional imaging data acquisition system based on an SIT detector coupled to an IBM-PC running the ASYST scientific software package (86K1512). Laser diagnostics (see also section 3.5) continue to play an important part in studying plasma processes and the multiplic- ity of techniques is reflected in the host of new acronyms thatJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. OCTOBER 1987, VOL.2 173R have invaded the literature. Omenetto et af. (86/1791) combined two laser beams spatially and temporally in the plasma to ionise and excite ionic fluorescence (double-reso- nance ionic fluorescence) and commented on the high spectral selectivity of this two-step process. A modification of this technique was used by the same group to study ion - electron recombination rates in the ICP. The recombination time constant for Sr was found to be 15.5 ps indicating an absence of fast ion chemical processes. The addition of an EIE increased the rate of recombination and the time constant was found to be proportional to the ion to atom ratio.The authors concluded that changes in the number density of the low- energy electrons were more significant in influencing the rate of recombination than the total electron density. Studies of the use of Thompson scattering for the direct measurement of electron temperatures and densities in the plasma have continued (86/1897,87/C786) and an improved instrument has been described that permits the simultaneous measurement of the scattered spectrum which removes the uncertainties associated with temporal fluctuations in the plasma and pulse-to-pulse variations in the laser power (86/C1507, 87/ C779). Turk and Watters (86/1891) used the double-probe technique to detect the laser-induced ionisation of Ca, Fe, Mn and Na, but found that the sensitivity was insufficient for analytical applications.Laser-excited fluorescence is most commonly used for mapping ground-state atom and ion profiles in the plasma and recently published data confirms the peaking of ground-state densities on the axis, accompanied by off-axis peaks in the emission profile, particularly at low viewing heights (86/1604). A similar study by Gillson and Horlick (87/1468) illustrated the prevalence of ground-state species throughout the plasma and clearly demonstrated the reduction in the atomic population close to the load coil and its reappearance in the recombination zones higher in the plasma. Reports of the operation of ICPs at pressures other than atmospheric, first noted last year ( J A A S , 1986,1, 126R), have now been published. As previously indicated, low pressures facilitate plasma operation with gases of high ionisation potential, e .g . , He, and thereby provide improved excitation for the halogens (86/1863). It has been noted that the observed excitation temperature increases with pressure, and as might be expected, there is a gradual shift towards LTE (86/1396). Tomasik and Zyrnicki (86/1776) reported the operation and spectral characterisation of mixed gas plasmas (Ar, CH4, C2H2 and N2) running at 5-10 Torr. The development of ICP-MS has promoted interest in the afterglow plasma formed when the tail-flame is sampled into a region of low pressure (0.7 Torr). Houk and Lim (87/1262) noted that the back- ground spectrum was composed principally of OH and NO bands, the H(3 line and Ar I lines primarily at wavelengths above 650 nm.The analyte spectra were similar to those obtained from a normal ICP (i.e., a predominance of ion lines) as were the effects of the addition of Na. The operation of ICPs in gases other than argon continues to be studied and the all-air plasma appears to be the one most likely to find routine application because of its cheapness for continuous operation. Meyer (87/514) has reviewed the characteristics of air plasmas emphasising the superior sample decomposition properties, and the reduction in torch wear and easier impedance matching compared with N2 plasmas ( J A A S , 1986, 1, 127R). Detection limits, however, were found to be 1-30 times poorer than for the Ar ICP with the best relative performance being obtained for lines with excitation poten- tials of less than 8 eV (87K1429).The potential of the air plasma for process-stream monitoring is evident and a commercial instrument, running on compressed air, has been introduced for this purpose (86/C1573). An air plasma has been used for the direct determination of airborne pollutants, notably particulate Be (87K1379). Alternative plasma confi- gurations, e.g., a needle-shaped plasma, were also investi- gated, but ultimately the best results were obtained with a conventional Ar plasma using air for the injector gas, but with Ar sheathing of the injector flow (87/C1378). The incorpora- tion of foreign gases, or the complete substitution of Ar, in the outer flow is quite common, but the conclusion that the presence of Ar is necessary for high sensitivity, reported last year (JAAS, 1986, 1, 127R), is supported by data from Choat and Horlick (87/626, 87/627, 87/628, 87/C1427).They investi- gated various admixtures of Ar with N2, O2 and He and found that a 10% N2 coolant provided over-all best performance. The effect of the N2 was to lower the optimum observation height, to increase analyte emission intensities and the ion-to-atom line intensity ratio, and to improve the SNR leading to improved detection limits. Pointers to the origins of these improvements were obtained from spatially resolved electron density measurements which showed that the reduc- tion in plasma size caused by the foreign gas was accompanied by a 30% increase in the electron density (87/629). The superior analytical performance of the Ar - N2 cooled plasma has also been demonstrated by Brenner (87/C888, see also 87/C1376) who obtained both improved detection limits and a reduction of interferences due to the presence of EIEs.A study of the spectra emitted from Ar-N2 cooled plasmas revealed that the most useful lines were generally those having wavelengths greater than 300 nm (87/33). The authors of this paper found, contrary to Brenner, that the interference from EIEs in their Ar - N2 plasma were higher than those obtained in an all Ar plasma. Montaser and co-workers (86/1606, 87/464, see also 87/C835 , 87/C1428) have now published their studies of an analytical He plasma, but the consumption of 8 1 min-1 He to improve halogen detection limits in the ICP might not suit every laboratory budget.The origins of molecular spectra emitted from a He ICP have been discussed (87/C832, 871C833). Spectral characterisation of the inductively coupled plasma provides essential information for line selection and the prediction of spectral interferences. Boumans and Vrakking (87/1465) determined the widths, shapes and hyperfine structure of 350 lines from 65 elements. The data were used to predict detection limits for instruments of differing band width and to establish objective criteria for line selection. The use of simulated spectra for line selection, referred to earlier, has been demonstrated by the generation of the Fe spectrum in the wavelength region from 360 to 381 nm (86/C1515). The simulation included the optical transfer function of the spectrometer in both the intensity and wavelength domains.High-resolution spectra of Pu between 200 and 700 nm have been obtained using a 1.5-m spectrometer (87/125, 87/1170). The hyperfine splittings were sufficient to permit the determi- nation of isotopic components. Recently published spectral data include near IR lines for Br, C, C1, F, H, I, N, 0 and S (86/C1561,86/1834), the VUV spectrum between 160 and 200 nm (86/1947), the Ni spectrum in the range 200-300 nm and lines suitable for geological analysis (87/1318). 2.1.2. Sample introduction The multitude of reports received each year describing new and improved techniques for sample introduction amply demonstrate that the inventive spirit is alive and well amongst ICP users. If an analytical problem cannot be solved with the standard ICP technique then a modification to the sample introduction procedure is often the simplest route to a satisfactory answer.Sample introduction for atomic spec- trometry in general has been reviewed by Sneddon (87/670), and Barnes and co-workers (86/C1493) have discussed sample introduction for the ICP with particular emphasis on methods for handling small sample volumes, e.g., electrothermal vaporisation (ETV) and recycling nebulisation systems. Car- penter and Ebdon (87/931) used the simplex procedure to optimise sample introduction configurations and found an advantage for larger injector tube diameters, 2 mm being174R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 selected for compromise multi-element analysis.Reports including work of general relevance to this subject area may be found in the following references (86/1660,86/1634,87/968, 87/1443). The vast majority of routine analyses performed with ICPs employ pneumatic nebulisation for sample introduction and as yet there is no alternative that appears ready to replace it. Parametric studies on nebulisation systems identify the rela- tionships between performance and operating conditions. A critical determinant of performance is the droplet size and Browner and Long (86/C1528) have determined primary and tertiary droplet sizes using laser particle sizing and have shown how these influence vertical spatial profiles in the plasma. Similarly, Routh (87/27) reported droplet-size distributions for various nebuliser - spray chamber combinations noting that the chamber is the principal component determining the nature of the aerosol reaching the plasma and that nebuliser selection is necessarily determined by the type of sample.Another comparison of direct and indirect methods for determining transport efficiencies has been reported. It was concluded, as expected, that analyte transport efficiency is best determined by direct methods such as aerosol collection, and that the total transport efficiency may be determined by either indirect or direct methods such as using a silica-gel trap (87/79). A comparison of nebulisers (concentric, cross-flow , frit, V-groove and ultrasonic) operating below 0.8 1 min-1 showed that the ultrasonic nebuliser gave the best perfor- mance, but was difficult to operate on a routine basis (86/2015).The frit nebuliser suffered from gradual clogging, even with pre-filtered solutions, and the concentric nebuliser did not yield a sufficiently high aerosol flux. The V-groove was therefore considered to offer the best compromise perfor- mance, although as is often the case with Babington-type devices, the efficiency was poor (less than 1% total). The previously described direct injection micro-nebuliser (JAAS, 1986, 1, 129R) has been compared with a cross-flow and an ultrasonic nebuliser for application with flow injection (86/ 1607). The relative detection limits using 30-pl samples injected into a 200 pl min-1 carrier stream were equivalent to 200-p1 injections into a cross-flow or 500-pl injections into an ultrasonic nebuliser, and the absolute detection limits were of similar magnitude to those reported for ETV-ICP-AES.The search for the ideal nebuliser continues and of the newer designs, the “thermospray” has attracted most atten- tion during this review period. Koropchak and Winn (86/ C1526, 87/599) obtained optimum performance when operat- ing a thermospray at 145 “C for a flow-rate of 1 ml min-1. They found that to take full advantage of the improved aerosol generation, a heated spray chamber and desolvation were necessary. Detection limits were improved by an order of magnitude, but the precision was somewhat poorer (3%) than that achieved by pneumatic devices. A conference report by the same workers indicated that they have determined droplet sizes for the thermospray, but no data were given in the abstract (87/C702, see also 87/1467).Support for the use of desolvation in conjunction with the thermospray was given by Vermeiren and Taylor (87/C1361) who also investigated stability criteria. An obvious application for high-efficiency nebulisation systems is for HPLC detection, and Elgersma and Maessen (87/1227) described a low-consumption thermospray for aspiration rates of 0.12 ml min-1. Relative detection limits were similar to conventional nebulisation, but at a 15-fold lower aspiration rate. A thermospray has also been employed for HPLC interfacing with organic solvents (87/C847). Closely related to the thermospray technique is the extraction of the analyte into a supercritical fluid, e.g., liquid CO2, and to employ the phase change to drive the nebulisation process.A device incorporating this concept has been described by Olesik and co-workers (86/C1524, 87/C718). The frit nebuliser has provided the highest transport efficiency of the pneumatic designs (87/C1009), but has proved to be prone to clogging of the frit pores. A new design, the grid nebuliser, employs a 100-mesh platinum gauze instead of a frit and appears to offer some of the advantages of the frit without its sensitivity to matrix components (87/C553). The practical realisation of the device uses two grids, one placed 2 mm in front of the other, which improves both the efficiency and the aerosol stability. The total transport efficiency (silica-gel trap method) determined for a sample flow-rate of 0.9 ml min-1 and a gas flow of 0.85 1 min-l was 4.7% compared with 2.9% for a conventional cross-flow nebuliser.Applications of this device included its use for high salt content solutions, i.e., sea water (87/C846), and with organic solvents for HPLC interfacing (87/C845). The grid nebuliser has characteristics similar to a Babington nebuliser, but at present only the V-groove type has found applications for use with slurries. Habiz and Brenner (86/ C1569) investigated the use of the slurry technique for mineralogical samples, but found it to be constrained by a need for prior knowledge of the textural, mineralogical and chemical nature of the sample. More favourable results have been obtained by Ebdon and co-workers (87/C162, 87/C163, 87/C539) who reported data for a wide variety of sample types based on aqueous calibration.These workers noted the importance of correct optimisation and of reducing particle size to 8 pm or less. A Babington nebuliser, incorporating a sample pre-heater, has been used for the direct determination of metals in lubricating oils (86/1463). Ultrasonic nebulisers have been shown to be superior to other types in terms of sensitivity, but poor stability, larger sample wash-out times and the need for desolvation has limited their application for routine analysis. Once again in this review year there were reports of improved devices, but it seems probable that they will only find application where extra sensitivity is essential. For example, Fassel and Bear (87/961) described a device with improved drive circuitry, incorporat- ing an etched PTFE surface for the active face.Detection limits were improved by 5- to 50-fold, but matrix interferences and wash-out times were inferior to conventional nebulisation sample introduction, and care was needed to avoid interfer- ences in the desolvation stage. Similar studies have been reported by other workers (861C1527, 87/C552, 87/C722, 87/C1217). The improved sample decomposition characteris- tics of the air ICP were used to advantage by Meyer (87lC1377) who employed a total consumption (without desolvation) ultrasonic nebuliser for sample introduction and achieved detection limits comparable to those obtained with Ar plasmas. Spray-chamber design remains an art rather than a science and thus the results of empirical design studies regularly appear in the literature.The simplest method of reducing sample consumption is to recirculate the deposited aerosol to the nebuliser and at least one such system is available commercially. Zicai and Barnes (87/633) have published their studies of a recirculating system employing a glass concentric nebuliser. It provided good sensitivity and precision, but longer term drift occurred through evaporation of the aerosol. Pre-saturating the Ar with water vapour was found to be an effective means of reducing this and of reducing matrix effects (871965). A recirculating nebuliser - chamber system has been used in the determination of soluble A1 in silicon steels (87/1438). Various spray-chamber geometries have been compared on the basis of transport efficiency, background equivalent concentration, emission stability, detection limit, equilibra- tion time and memory effect.From these results, Dale and Buchanan (8611893) found that a 180-ml cylinder with a central tangential inlet and symmetrical axial aerosol take-off tubes provided best over-all performance. Legere and Burgener (86/C1529) studied the effects of spray-chamber geometry by the simple expedient of modifying the chamber shape and volume with paraffin wax. They noted that it wasJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. OCTOBER 1987, VOL. 2 175R possible to reduce memory effects, but only at the expense of less than optimum noise performance. A miniature cyclonic spray chamber has been described which it was claimed offers shorter wash-out times, improved SNRs and reduced drift compared with conventional designs (86/1627).Organic solvents are routinely used for determinations carried out by ICP-AES and the techniques employed for handling them are now well known. Maessen and Balke (87/24, 87/C1358) have now published the results of their studies of controlling the plasma solvent loading using a cooled spray chamber. They noted that whereas the plasma solvent load is determined by the saturated vapour pressure of the solvent, the distribution between the liquid and vapour phases is controlled by the evaporation factor. Magyar et al. (87/64) employed both aerosol drying and 02-feeding and noted a synergistic enhancement in the sensitivity. A principal effect of adding O2 was to reduce background radiation levels in the plasma to those obtained with aqueous samples.Dittrich and Niebergall (87/256, 87/1314) observed that chlorinated solvents produced suppressions of the emission intensities of Ge, Pb and Sn and suggested that this was due to the formation of the metal chlorides. A study of the selection of organic solvents for ICP-AES produced the expected result that solvents of low volatility such as decane, pseudo-cumene, xylene, dodecane and a petroleum fraction (b.pt. 150-200 “C) are preferred. Volatile solvents can be handled by the methods described previously and/or by a reduction in the aspiration rate (to 0.1 ml min -1 or less), but Nygaard et al. (86/C1559, 87/C717, 87/1272) have described a new auto- tuning r.f. generator which has a greater tolerance to changes in the solvent loading. The direct injection of gases or vapours into the ICP avoids the inefficiencies of nebulisation and consequently offers improved detection limits.For example, a low-pressure plasma has been coupled with a small volume (1 ml) gas sampling valve and used for the determination of deuterium, H2 and N2 admixtures (87/C137). Silicon impurity in trimethylgallium has been determined by mixing it with Ar in an exponential dilution flask prior to injection into the plasma (87/59). The determination of dissolved organic carbon (DOC) in water has been achieved by conversion into CO2 in a CuO reactor and measurement of the C atomic emission. A detection limit of 0.3 mg 1-1 DOC was reported (86/1675). Hydride generation is the favoured method for improving the sensitivities for As, Pb, Se and Te (87/C1359).The temporal signal profile of a hydride generator has been modelled by Wang and Barnes (87/632) who noted that the optimum carrier gas flow-rate reflected a balance between maximising the hydride flux and the operating requirements of the plasma. The volume of the gas - liquid separator was also found to be critical with smaller volumes leading to higher signals. Continuous hydride generation has been used for process stream monitoring (86/ClS21), and an “off-line” single-pulse hydride generator has been described for the analysis of small sample volumes (100 pl) (871C1360). The capability of the ICP for tolerating the direct injection of solids, usually from fluidised bed devices, has been known for many years.However, for the reasons given last year, the technique has not become widely used. Development work nevertheless continues and de Silva and Guevremont (871624, 87/625) reported studies on the determination of several elements in silica, silica-immobilised 8-hydroxyquinoline and Chelex-100 resin. Internal standards were used to help control some of the variables and these appear to be essential for direct solids analysis (860785, 87/100). Allen and Coleman (87lC699) have described a new approach to solid sampling which uses two plasmas in tandem, run from a single generator. Hopefully segregation of the sampling and excita- tion stages in this manner may result in a reduction of matrix effects. Electrothermal vaporisation ( E TV) sample introduction is becoming the established technique for the analysis of small sample volumes and where improved detection limits are required. The maturity of this approach is reflected in the appearance of two reviews during the past year covering instrumental developments and current performance capabil- ity (87/416, 87/515, 87/1252).Following the work of Snook et al. (JAAS, 1986,1, 130R), Kantor (87/C1123) has considered the factors influencing the condensation and coagulation of atomic vapours. It was shown that low concentration atomic vapours do not nucleate sufficiently and that the addition of a matrix is necessary to improve analyte transport to the plasma. A simple means of producing the “carrier aerosol” is by the pyrolysis of hydrocarbon or halocarbon vapours introduced into the furnace.Conference reports from Schmertmann et al. (86/C1492) and Buckley and Boss (86/C1578) indicate that work is in progress to study the effect of matrix composition and particle-size effects on transport efficiency. There have been relatively few descriptions of electrothermal devices for ICP-AES, but Matusiewicz et al. (87/522) modified a commer- cial graphite furnace atomiser to accommodate customised cuvettes, while Ohls and Butsch described a graphite crucible mounted between carbon electrodes for sample introduction into low-power Ar (87/231) and high-power Ar - Nz plasmas (87/232). There has been a further report (JAAS, 1986, 1, 130R) of the use of time gating to reduce matrix interferences (86/1779), and a commercial instrument has been introduced that allows the acquisition of simultaneous, multi-element, time-resolved signals (87K1363).The problem of rapid background correction has been addressed by the incorpora- tion of a rotating refractor plate into a spectrometer which permitted the line and background signals to be sampled 20 times per second (86K1490). Applications of ETV-ICP-AES have included the analysis of particulate matter collected on air filters (86/1805), the determination of Cd and Zn in metallic samples (87/258) and of trace elements in nickel- based alloys (87/C165). There have been no significant developments in direct sample insertion devices (DSID) and for the reasons given last year, ETV is favoured in most applications. However, for volatile elements DSIDs work well (87/41, 87/C1365) and there have been further developments (86/1992,87/600) of the equipment first described by Horlick and co-workers.Spark sampling produces a fine aerosol well suited for introduction into the ICP. The direct sampling of molten metals has been reported for use in the steel-making process. Ono et al. (86/C1491) described the transport of an aerosol, produced from molten steel, through a 4 mm i.d. tube over a distance of 40 m €or introduction into an ICP. Silicon was determined down to a level of 0.003% and at 0.21% Si the RSD was 0.7%. Similarly, major, minor and trace elements have been determined directly in molten lead and lead - tin solders (86/C1533). Spark sampling is normally used in conjunction with multi-channel spectrometers which facilitate internal standardisation.Prell and Koirtyohaan (87/C815) used a sequential spectrometer and with 5-s integration times achieved precisions of 5% for single-day operation; intensity ratios for Cr, Cu, Fe, Mg, Mn and Ni with A1 as the internal standard yielded a precision of 1 70. Further reports of spark sampling may be found in the following references: 87/C1362, 87/C1364 and 87/1445. Laser ablation (see section 2.1.5.) for sample introduction has received little attention during this review period, but two reports of note shared a common theme in that powdered samples were handled by briquetting prior to ablation. In one (87/435), iron oxide and furnace dust specimens were pressed into discs prior to sampling, and in the other (87/937) mineral powders were fused with ammonium fluoride and ammonium sulphate to reduce the effects of particle structure.2.1.3. Flow injection and chromatography There have been no significant developments in the applica-176R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 tion of flow injection for ICP-AES during the past year, but two reports noted previously (JAAS, 1986, 1, 131R) as conference presentations have now been published (8611671, 87/339). The application of the ICP as a detector for high-perfor- mance liquid chromatography is limited by the inefficiency of the nebulisation process in transporting eluted analyte to the plasma. To circumvent this problem, Nisamaneepong and Caruso (86/1751) have suggested the use of an electrothermal vaporiser as the transport interface. A carbon-cup device was used to vaporise collected fractions and although this system does not enjoy the convenience of an on-line detector, it does offer excellent sensitivity.The system was demonstrated by the determination of tetraphenyl- and hexaphenyl-dilead for which the absolute detection limits were 0.8 and 0.3 ng Pb, respectively. Denton et al. (86/C1482) have suggested that the range of application of HPLC - ICP-AES might be extended by simultaneous multi-element analysis using array detectors. An on-line cold vapour generation procedure has been applied in conjunction with HPLC to the separation and determination of inorganic and organic compounds of Hg (86/1645). It was noted that the polypropylene nebuliser - spray chamber system showed a significant memory effect with Hg and that this was removed by the use of a glass hydride generation chamber.On-line hydride generation has been coupled with ion chromatography in order to separate and determine SeIV and SeVI with detection limits of 1.6 and 2.5 ng ml-1, respectively. Applications of LC - ICP-AES have included the determination of CrI" and CrVI in water samples (86/1949), the determination of As compounds in biological materials (87/13) and the identification of silicones in anti- foaming agents, car polish and cosmetics (87/407). The ICP might be considered a rather expensive detector for GC when there are less costly alternatives such as the MIP, nevertheless GC-ICP-AES has been used for the determination of organometallic compounds including those of Se (87/88). 2.1.4.Chemometrics The most widely used optimisation procedure is that based on the simplex algorithm. A comparison of simplex procedures has resulted in a new development of the super-modified simplex which it is claimed offers both improved speed and accuracy (86/1728). Simplex optimisation has been used to overcome a matrix effect from variable concomitant levels (0-70%) of acetic acid in the determination of Cr, Cu, Fe, Mn, Mo, Ni and Zr (87/127). Davidowski (87/CS48) has suggested an alternative, the Fletcher - Powell directed search algorithm for automatic instrument optimisation, while Yao (87/276) used an orthogonal experimental procedure to establish optimum conditions for anal ysing environmental water samples.Calibration, like many other aspects of quantitative spec- trometry, is being influenced by the availability of low-cost computing power. Last year, reference was made (JAAS, 1986, 1, 132R) to the plotting of spectral and intensity data of several elements in multi-variate (hyperspace) co-ordinates. There has been a further report on this technique demonstrat- ing the preparation of multi-dimensional working curves and the use of pattern recognition and factor analysis for qualita- tive analysis (86/1471). Returning from hyperspace to Earth co-ordinates, Hashimoto et al. (864708) described the use of simulated spectra coupled with pattern recognition for the determination of REEs. The non-constant variance of ICP calibration data poses problems when least-squares regression procedures are used to fit curves to the data, particularly over wide calibration ranges, Many workers employ logarithmic transformation of the data to reduce this problem, but Watters (87/C711) has described a procedure for modelling the variance to enable appropriate weighting of the fitting procedure.The necessity of weighting was the subject of comment by Taylor and Schutyser (87/1258) who compared results from weighted and unweighted calibrations. Internal standardisation should not be necessary for a stable source such as the ICP, but imperfections in the instrumenta- tion, sample delivery system, and effects caused by high levels of concomitant matrix can be overcome by judicious applica- tion of this technique. A review of the use and misuse of internal standardisation has been presented by Moore (871 516).The generalised internal-reference method previously described (JAAS, 1986, 1, 132R), has been applied by Lorber et al. (87/43) to the analysis of metallurgical samples. Single-point calibrations were used and precisions in the range 0.1-0.?1~/0 were obtained. The parameter related internal standardisation (PRISM) method described by Thompson and Ramsey (JAAS, l986,1,132R) has been the subject of further discussion (86/C2036, 87/C155). Considering the origins of matrix effects, these authors noted that there was a strong correlation between the degree of interference and the excitation potential of the analyte line and contended that this was consistent with a cooling of the plasma by the matrix (87/488, 87691).They have also described an automated on-line dilution device for interactive matrix matching to reduce both matrix and spectral interferences (87/C219). Sedcale and Pritchard (87/72) examined matrix interactions in the presence of calcium, potassium, sodium silicate, poly- maleic acid and DTPA. Subsequently, using up to six internal standard elements, they compensated for the effects of these matrices using either direct internal standardisation or correc- tions based on the analysis of covariance (87173). The application of internal standardisation to the analysis of geological materials has been discussed by de Silva (87/C885), and to the analysis of metallic samples by Ohls and Loepp (864698). The characterisation of noise sources in the ICP is an essential first step to their reduction and ultimately to the improvement of detection limits (871C200).The effect of integration time and time interval between measurements on the precision attained with three different nebulisers was investigated by McGeorge and Salin (86/1730). They found that a short-term precision of 1% was obtainable with integration times as short as 0.1 s and that 0.4% precision was achievable under favourable circumstances. The interval between integrations was, however, found to be more important in controlling the working precision and it was therefore concluded that fast chamber wash-out times and rapid sample changeover should be used to reduce the period between calibration and measurement. A sensor and gas flow control valve have been coupled to provide mass-flow control in the nebuliser and sample sheathing flows on a sample introduction system of the type first described by Mermet et al.(Mermet, J. M., Trassy, C., and Ripoche, P., in Barnes, R. M., Editor, "Developments in Atomic Plasma Spectro- chemical Analysis," Heyden, Philadelphia, 1981, pp. 245- 250). This provided a stability of 5% for 34 elements determined during a period of one day (87/28). The identification and quantification of spectral interfer- ences in the ICP has been greatly advanced by the continuing work of Boumans and Vrakking. During this review period they have attempted to provide a basis for the comparison of detection limits obtained on different equipment (86/186S). They concluded that differences could be attributed to three factors: differences between the sources, the resolving power of the spectrometers and the noise characteristics of the systems.In quantifying these differences, they used previously obtained results for the RSD of the background signal and a newly established relationship which showed a linear depen- dence of the ratio of the SBRs at high and medium resolution on the inverse ratio of the effective line widths. In addition to the spectral data reported in section 2.1.1. (87/C1320, 87/1465), results were also presented on spectral interferences caused by OH bands (8611864); 100 prominent Iines wereJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 177R studied and of these, seven were found to suffer very serious interference and 18 to suffer serious interference with optical band widths of 5 and/or 15 pm.An empirical technique for correcting spectral interferences, based on determining the line-width ratio from experimental data, has been described by Farwell and Kagel (87/1256). 2.1.5. Instrumentation General instrumentation for ICP-AES is dealt with com- prehensively in the ASU review on “Instr~mentation,’~ (JAAS, 1987,2,79R). The reports discussed in this section are included because they contain information of relevance to the theme atomisation and excitation. An exception to this, but worthy of note, is the report by the Analytical Methods Committee (Analytical Division, Royal Society of Chemistry) which provides detailed criteria for the selection of poly- chromators for use in TCP-AES (86/1980). Torch design and generator frequency are inseparable variables as has been demonstrated recently by Michaud- Poussel and Mermet (86/2016).Using generators of 27,40,56, 64 and 102 MHz they found that the higher the frequency the lower the gas consumption for a given torch geometry. The most critical factor in torch design was found to be the outer gas inlet area which controls the gas velocity, but it was noted that torch dimensions became less critical as the operating frequency was increased. A lower gas flow limit of 3 1 min-1 was found to be necessary to stabilise a toroidal plasma in Ar regardless of the particular frequency - torch combination used. A demountable torch was described in which the outer gas inlets were independent of the outer tube, facilitating its replacement.These findings were supported by Rezaaiyaan and Hieftje (86/1732) who found no particular advantages of using a miniature torch (13 mm) in terms of gas flow or power input, and noted a slightly inferior performance with respect to vaporisation interferences. Nevertheless, a commercial version of a mini-torch has been introduced and there will no doubt be numerous reports of its application (86/1809, 87/C224, 87/C1350). The performance of a very high fre- quency 148-MHz plasma has been compared with that of a conventional 27-MHz plasma (87/116). It was found that Fe I excitation temperatures were 1 ..%times lower and electron densities 5-times lower than at 27 MHz. This led to reduced line and background intensities and a shift away from ionic emission. Inter-element interferences were reported to be the same as those in the 27 MHz ICP.Burton and Blades (86/1840) compared excitation conditions in a conventional and a high-efficiency (MAK) torch. They found that the high-efficiency torch , unlike the conventional torch, produced high on-axis excitation temperatures in the normal analytical zone necessitating the use of lower observation heights. This was attributed to improved mixing between the annular plasma and the gas in the aerosol channel. de Galan and co-workers have continued their work on low-flow externally cooled plasmas and have reviewed the recent developments (87/590). Analytical data for an air-cooled ICP running at 1 1 min-1 and 600-900 W input power have been presented (86/1605).Detection power was similar to that of conventional devices and plasmas could be sustained at powers down to 400 W, but higher powers were required for excitation of lines below 250 nm, for the introduction of organic solvents and the use of hydride generation. A study of torch materials revealed that silicon nitride and boron nitride were satisfactory in terms of their thermal properties and r.f. transparency, but both were prone to oxidation at temperatures of 1600 K (871 C1351). The characteristics of the laminar flow torch, men- tioned in section 2.1.2. have been studied by Davies and Snook (87/521). Noise power spectra revealed that the discrete components (100-400 Hz range) , normally observed in conventional torches and attributed to plasma rotation, were indeed absent in this design. Electron densities were found to be lower than in a conventional torch, but ionisation temperatures were similar and improvements in detection power of one order of magnitude over those obtained with a conventional torch were obtained. The technique of using a sheath gas around the aerosol - gas mixture in the injector has been shown to be useful in providing superior excitation conditions for the alkali metals leading to improvements in detection power of up to 20-fold (87/C1402).2.1.6. Inductively coupled plasma mass spectrometry (ICP- The rapid growth and development of TCP-MS has continued and this is reflected in the increasing numbers of papers appearing in journals such as JAAS. One estimate is that approximately 80 commercial systems have now been installed (87/C861).The progress and achievements of ICP-MS have been reviewed by Gray (86/1608, 87/665) and an introductory review has been presented by Taylor (87/1436). The occurrence of oxide species and doubly charged ions is known to be strongly influenced by the design of the ion-extraction interface. Some early designs were found to produce a small arc-like discharge between the plasma and the sampling orifice. This so-called “pinch-effect” has been investigated by Douglas and French (87/70) who attributed its origin to a capacitive coupling of the r.f. voltage on the coil to the bulk plasma. Using a centre earth tap on the load coil, the r.f. voltage drop across the coil was reduced and the discharge removed.This resulted in a slight increase in the oxide levels produced, but a substantial reduction in the numbers of doubly charged ions, in the spread of ion energies and in degradation of the sampling orifice. A subsequent study of ion kinetic energies showed that these are of the order of 2 eV, increasing with ion mass and consistent with a temperature of 5000 K (87/1249). Inductively coupled plasma mass spectrometry systems have usually been configured with generators running at 27 MHz, but for optical detection there is an increasing move towards higher frequencies (40-50 MHz) and these are now being investigated for MS detection although detailed data are not yet available (861C1488, 87/C1341). Similarly, and inevitably, gases other than Ar are being investigated, for example Ar - Nz (outer flow) (87/C1329) and He (87/C1339).There have been several reports of optimisation of ICP-MS systems, but it is clear that there is not yet agreement on the kind of operating conditions required to meet particular criteria, e.g., sensitivity, reduction of oxide and/or doubly charged species, reduction in matrix effects and/or the effects of EIEs. The parameters to be considered are those determin- ing plasma performance, i. e., sample introduction rate, gas flows and power, the sampling depth and, additionally, parameters affecting the quadrupole and ion optics, e.g., ion-lens voltages. It is generally agreed that the power and injector flow-rate are the most critical plasma parameters. Horlick et al. (87/106) have now published their findings on the effects of univariate changes in operating parameters on analyte ion signals.For the purpose of these investigations, elements were grouped according to their characteristic physico-chemical behaviour. After power and injector flow- rate, a moderate dependence on the auxiliary flow was noted, but remarkably the ion count rate was found to be indepen- dent of the sampling depth in the range 17-20 mm from the load coil. Long and Brown (87/642), using a different instrument, obtained data generally consistent with those of Horlick et al. (87/106), but an important difference was that optimising the ion count signal also minimised the signal from oxide and doubly charged ions thus providing a more universally applicable set of operating parameters.The optimum sampling depth obviously depends on other parameters, but whereas Horlick et al. (87006) found that it had little effect on ion count rate, Hutton et al. (86/C1489, 87/C825) considered it to be a critical parameter, particularly M S )178R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 in relation to matrix effects and advocated sampling close to the load coil for their reduction. Alternatively, for the determination of REEs, Doherty and Vander Voet (86/1670) employed the characteristic vertical emission profile of Y to position the sampling orifice in the normal analytical zone as used for optical detection. Lichte et al. (87/C1337) studied ion extraction lens voltages with respect to matrix effects. They noted that these are normally optimised for transport of the common ions found in the central channel (Ar, Ar+, ArH+, H+, H20+, Of and OH+).The presence of heavier ions, e.g., Baf , caused severe interference effects and this was attributed to space charging caused by the heavy, slow moving particles. Adjustment of the applied voltages minimised the effect, but at the expense of sensitivity. The mass dependent nature of matrix effects was also noted by other workers (86K1483, 86/C1499, 87/C740). Ultimately, the optimisation of systems with interacting parameters requires a multivariate technique and thus Taylor has applied simplex optimisation to the analysis of ground waters by ICP-MS (861C1474). Interferences in ICP-MS may be classified as for ICP-AES into “spectral” and matrix interferences, but it must be emphasised that whilst the former are less severe than in ICP-AES, the latter are considered to be more severe in ICP-MS.However, the absolute levels are dependent on the operating parameters (as discussed above) and therefore results obtained with a particular system would not necessarily be obtained with others. Referring first to spectral interfer- ences, extensive tables of oxide, hydroxide, doubly charged ion and background features have been published by Horlick and co-workers (87/29, 87/30). Similarly, McLeod et al. (87/67) have reported on metal oxide interferences observed in the analysis of nickel-based alloys. The ratio of MO+/M+ was found to be of the order of 0.2%. For the most refractory oxides, e.g., CeO and L a o , Boorn et al.(87/C1386) reported MO+/M+ ratios of 1%. The occurrence of polyatomic ions, derived from the solvent, has prompted the development of sample introduc- tion techniques which either use the solid material directly, or remove the solvent. Thus there have been reports of the use of electrothermal vaporisation devices. Park and Hall (87/C811) described a graphite platform vaporiser for the determination of Mo and W in geological materials. Freon gas (2 ml min-1) was injected around the platform to prevent carbide formation and improve the volatility of these refractory elements. Another report from these workers described the determina- tion of T1 in geological materials at levels down to 0.1 pg g-1 (87/C902). A Re- or C-filament vaporiser has been applied to the analysis of environmental and biological samples (87/ C870).A tungsten-wire loop has been used in the direct insertion mode and some impressive distilled water detection limits obtained, viz. Ag 0.02, As 0.5, Cd 0.05, Cu 0.027, Li 0.075, Mn 0.09 and Pb 0.03 ng ml-1 (87/105). The use of laser ablation for sample introduction has been pioneered by Gray who has described calibration procedures based on the use of SRMs and synthetic mineral standards (87/C813, 87/C1338). Arrowsmith et al. (87/C826) compared C02 and Nd : YAG laser sampling. The latter was preferred because of its improved spatial resolution (100 pm), high peak power (enabling the sampling of refractory materials) and the ability to operate at a repetition frequency of 10 Hz which provided a quasi-continuous signal for mass spectrum scan- ning.Detection limits of 10 ng g-1 directly in the solid are obtainable by this technique. An alternative to laser ablation for conducting materials is arc nebulisation. Jiang and Houk (87/60, 87/C810) described the use of an intermittent arc, with the metallic sample as the cathode. Detection limits in the solid were at the yg g-1 level with linearity extending to 0.1 % m/m, and precisions and accuracy were of the order of 5%. Liquid nebulisation for sample introduction has received little attention in relation to ICP-MS during this review period. Browner (87K1324) has outlined the various stages of liquid sample introduction and with Faske (86/C1487) de- scribed the use of a monodisperse aerosol generator for introducing samples from LC and FI into the plasma. A report from Fulford et al.(86/C1483) suggested that a high-pressure cross-flow nebuliser (MAK) provided measurable improve- ments in precision over a conventional concentric device. The technique of adding O2 to the injector flow when introducing organic solutions to the plasma has been shown to work equally as well for mass spectrometric as for optical detection (86/C1476, 87/C188). The analytical performance of ICP-MS has been well documented, but this year particular attention has been given to the limiting factors. Gray (87166) concluded that at masses below 80 u, the detection power is limited by the analytical blank and by peak coincidences with polyatomic ions formed in the plasma. At higher masses, the detection power is limited by the attainable SNR of both lines and background.The inadequacy of normal analytical-reagent grade solvents for controlling the blank at low levels has been emphasised by Hutton et al. (87/C1381). A comparison of ICP-MS and ICP-AES for determinations in complex matrices concluded that for elements above mass 80 ICP-MS has substantially superior powers of detection. In the lower mass range, some elements such as Co have excellent sensitivity whereas others such as Ca, Cu, Fe and Ni suffer from interference and are best determined by AES. Recent applications of ICP-MS include the speciation of trace metals in foodstuffs following separa- tion by HPLC (87/C1393), the determination of halides (87/C1392) and other non-metallic elements by negative ion detection (87/C741), the determination of trace elements in geological samples (87/68) and the isotopic determination of Fe in human faeces (87/15).Isotope ratio and isotope dilution analyses have no counter- parts in the emission technique and therefore ICP practition- ers are having to acquire established wisdom from techniques such as thermal ionisation mass spectrometry. Isotope ratios can currently be determined with a precision of ca. 0.1% (871C164, 87/C1385), but the mode of measurement appears to be important. Douglas and Quan (86/C1485) found that peak hopping was preferable to mass scanning and that for a given total measurement time, a large number of repeat samples with short dwell times was preferable to a smaller number of repeats with long dwell times.It seems probable that this arises from the non-stationary nature of the statistical population being sampled. Comparing calibration methods, McLaren et al. (86/C1971) commented that external calibra- tion with a standard curve, though convenient, is the most prone to error, particularly when the sample composition is different to that of the standard. The standard additions and isotope dilution techniques overcome this problem, but inaccuracies still arise through the occurrence of spectral interferences. The application of isotope dilution to the characterisation of reference materials has been discussed by Paulsen (86/C1475). 2.1.7. Inductively coupled plasma atomic fluorescence spec- trometry (ICP-A FS) Atomic fluorescence has always held great promise for analytical spectrometry, but its application has been ham- pered by the lack of a universal source of high intensity, high stability and narrow band width.The use of a second ICP as advocated by Greenfield partially solves this problem and it remains to be seen whether the spectral selectivity of the technique is a sufficient advantage to promote its commercial development. Recent developments have been described and these show improvements in sensitivity over the emission technique for non-refractory elements, but poorer sensitivity for refractory elements (86/1603, 87/286,87/460). A source of carbon atoms in the atomiser plasma, e.g., propane gas, was shown to be essential to provide a reducing environment toJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 179R prevent the formation of oxide species. The use of organic additives was discussed in a separate publication (87/613) in which it was shown that for W, an ethanolic solution provided a two-fold improvement in sensitivity compared with the use of a hydrocarbon gas. The mechanism of the reduction process has been investigated by Bolton and Long (87/C778). The high spectral selectivity of the ICP-AFS technique has been demonstrated by the determination of Zn in a copper alloy which has emission lines at 213.856 (Zn) and 213.851 (Cu) nm (87/C135). Non-resonance fluorescence has also been advo- cated for overcoming spectral interferences (87/C178). Wine- fordner and co-workers (86/C1497, 86/1881) have been the other principal proponents of the dual plasma AFS technique, but their system differs from that of Greenfield and Thomsen in that a conventional, 1500 W, Ar plasma is used as the source rather than a high-powered, large diameter plasma.For the determination of major sample components, the resonance monochromator technique was proposed in which the sample is introduced into the source plasma and used to excite fluorescence in the atomiser plasma. Studies of the power dependence of absorption, emission and fluorescence signals in an extended sleeve torch produced some unexpected results (87/637). For non-refractory elements the fluorescence inten- sity decreased with increasing power, and as might be expected increased for refractory elements. However, ano- malous behaviour was observed for the alkaline earth ele- ments which displayed double maxima which were attributed to the occurrence of chemical equilibria with the dissociation products of HzO.The extended sleeve torch was also used for laser-excited fluorescence, but showed a considerably larger interference from EIEs than a conventional torch (87/919). An excimer pumped dye laser was used for the determination of precious and refractory metals (86/1875). Leong et al. (87/1199) have now published a description of their use of stimulated Raman scattering of tunable dye laser radiation for the excitation of spectral transitions in the UV. The flow-rates used in atomiser plasmas for AFS are often quite different to those used for emission and the relatively high injector flow of 2 1 min-1 was found to provide improved nebulisation performance with a concentric nebuliser em- ploying a close-in impact bead (871C1354).The similarity to a conventional AA nebuliser - impact bead system is evident. The tandem plasma has been proposed as an atomiser forAFS, but it will have to show some significant advantages to warrant the extra complexity (87lC828). 2.2. Microwave-excited Plasmas 2.2.1. Fundamental studies Various types of microwave plasma have been characterised using both spectroscopic and physical techniques. Brown et al. (86/C1591, 86/C1598, 87/C787) determined electron density (n,) by examination of the shape and width of the H(3 line at 486.133 nm together with the series limit approach utilising He lines in the Balmer series. They concluded that the line-shape method gave the most accurate results compared with the line width or series limit methods which produced over-estimates of n,.The work of this group on spectroscopic temperature measurement and laminar flow torch design was reviewed last year (see JAAS, 1986, 1,134R); these studies have now been published (87/34, 87/652, 86/1917). Diamy et al. (87/113) measured electron temperature (T,) and n,, using double probes, on a reduced pressure (0.5-10 Torr) discharge operating at 320 W. They studied the production of oxygen metastable species [0(5S)] as a function of discharge pressure, and oxygen and helium metastable [He(%)] concentrations. These were determined by AAS measurements at 777.196 nm for 0 and 388.865 nm for He. Selby et al. (86lC1596) employed a two-dimensional imaging system and SIT vidicon detector to study the spatial emission characteristics of a surfatron-sustained plasma.They used this device to make a comparative study of the surfatron and Beenakker cavities and found that the former exhibited superior performance with regard to analyte emission and inter-element effects. Atomic and ionic emission intensities for various metallic species directly nebulised into He and Ar plasmas (300-600 W) have been measured (87/C793). The effects of EIEs were observed in both these sources. Pak and Koirtyohaan (87/ C706) carried out studies on atomisation and excitation processes for non-metals in a moderate power (500 W) He MIP using direct nebulisation. Their observations included EIE interferences together with radial and axial temperature profiles of annular and non-annular discharges.Burns and Boss (86/C1601) reported on the actual quantity of power that is coupled into the discharge for transformation into plasma excitation energy and on the use of high dielectric probes to achieve efficient coupling at low forward power (10-50 W). The significance of the work requires some emphasis as all too often quoted power levels are no more than a reading on a meter, which does not directly measure the power dissipated in the plasma (see also 87/71). Analytical figures of merit for air and nitrogen microwave plasmas have been presented (87/654) using pneumatic nebulisation and power levels of 300-500 W. Interference from molecular emission and EIEs was found to be significant in both plasmas.It would seem unlikely that this type of spectrochemical source offers a serious challenge to the ICP. Xenon lamps filled at pressures of from 0.9 to 5.0 atm were excited in a surfatron cavity at powers up to 300 W (86/1944). The spectral and noise characteristics were compared with those of a commercial 150-W high pressure xenon arc. The latter had a better continuum-to-line ratio. Nevertheless, the absence of electrodes and improved SNR of the microwave sources were considered to be of potential value for conti- nuum-source AAS. The utilisation of Fourier transform spectrometers to characterise the near infrared (NIR) spectral emission from non-metals in a He MIP has resulted in two extremely useful reports (87/646, 87/647). These two studies have demon- strated the utility of the MIP for multi-element analysis of non-metals provided that suitable sample introduction systems can be developed.Both papers provided a spectral atlas for the MIP in this spectral region plus data for mechanistic studies. 2.2.2. Instrumentation Over the past year interest has been shown in the utilisation of microwave-supported discharges as atom cells for AFS. Lysakowski et al. (86/C1501, 86/C1502) evaluated Ar, He, N2 and N2 - Ar plasmas operating at atmospheric pressure for LAFS. They also developed an improved system of coupling microwave power to N2 or N2- Ar sources used for LAFS (86/C1539). Pre-atomisation was achieved with a micro-arc (Hieftje, G. M., ARAAS, 1979,9, ref. 1732). The same group have studied the relative merits of continuum versus line source MIP-AFS (87/C829) using a low-power MIP with pneumatic nebulisation and desolvation.A surfatron plasma has also been evaluated as an AFS atom cell (87/C831). A review, in Polish with 134 references, covering the areas of microwave plasma instrumentation and sample introduc- tion has been published (86/1860). 2.2.3. Sample introduction Nebulisation into low-power MIPS supported in TMolo cavities has again been reported (87/356, 87/C1008, 87/C1125, 871 C1127, 87/C1356). There are, however, underlying problems with this form of sample introduction, namely poor atomisa- tion and excessive water vapour loading in the plasma which degrades signal intensities and erodes discharge tubes. Stahl and Timmins (87/C1356) observed that water vapour was not180R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 totally eliminated after desolvation and hence that the achievable detection capability was inferior to that of alterna- tive sample introduction techniques. Ng and Shen (87/356) reported the direct nebulisation of aqueous standards and diluted synthetic sea water samples into an Ar MIP sustained in an alumina tube. These workers claimed favourable comparability of detection limits for In, Mn, Pb and Sr with ICP-AES. However, none of the wavelengths they employed would normally be used for ICP-AES because of their low sensitivity, thus the comparison was invalid. It was noteworthy that all these lines were at wavelengths above 360 nm, which was a result of using a glass focusing lens on the spectrometer.Michlewicz and Carnahan (87/C721 , 87/1268) investigated pneumatic and ultrasonic nebulisation with and without desolvation into a moderate power He MIP for the determina- tion of Br, C1 and I in aqueous solution. This publication is an extension of their previously reported work (Michlewicz, K. G., and Carnahan, J. W., Anal. Chem., 1985, 57, 1092). The ultrasonic nebuliser with desolvation gave the best analytical figures of merit. However, with this system the observed interference effects were more pronounced. It is worth reiterating that the attendant problems of nebulisation into any type of MIP are such that these plasmas are more readily usable as spectrochemical sources when the analytes are introduced in the vapour phase.Electrothermal vaporkation into microwave-excited dis- charges has been around for about a quarter of a century (see Mavrodineau, R., and Hughes, R. C., Spectrochim. Acta, 1963,19,1309). Only recently have there been studies carried out to understand more fully this form of sample introduction. The interferences of EIEs on analyte emission from ETV-MIP have been investigated by Matousek et al. (87/120). They concluded that enhancement or depression was both analyte and spectrally dependent. They also felt that it was not possible to provide a simple explanation of their observations because of the convolution of processes occurring at the vaporisation, transportation, atomisation and excitation stages. This group have examined the utility of a graphite electrothermal vaporiser for the MIP determination of C1, I, P and S (87/1319).They reported that the slope of the log-log calibrations for C1 and I were significantly greater than unity (1.38 and 1.57, respectively). After determining that the slopes had not resulted from an instrumental artifact they postulated that for the MIP a complicated relationship between concentration and analyte emission exists. Other workers (87/1295) determining I with a tantalum electrother- mal vaporiser did not observe this effect. Matousek et al. (8711319) suggested that these increased slopes may provide improved precision for a given concentration. Metallic vap- orisers have been used for the metalloid elements (87/C209) and these devices do not introduce carbon into the plasma which can result in spectral interference from molecular species such as C2, CO, CN and CH (87/1319).A technique akin to ETV is evolved-gas analysis or pyrolysis. In this method, solid or liquid samples are thermally degraded under a controlled temperature and atmosphere and the resultant vapours are transported to the plasma for spectroscopic examination. Solid samples, as either particu- lates or as a coating on a silica capillary, have been introduced into a reduced pressure MIP maintained within an Evenson quarter wave cavity (86/C1597). The resultant emission was monitored with a polychromator to estimate the elemental composition of the solid. The elements determined were C, Cl, H, P and Si. Kimura et al. (87/953) observed molecular emission from the N2 second positive band head at 337.13 nm and the CO 5B band head at 307.99 nm by exciting eluent from an O2 plasma asher in order to determine the N content of organic samples. Bauer (861C1602) pyrolysed various carbo- nate minerals and the decomposition of particular carbonates was monitored by sweeping the evolved carbon dioxide into a He MIP.The measurement of C emission in relation to pyrolysis temperature provided a means of speciating trace levels of carbonates in geological samples. Pyrolytic or chemical degradation of solid samples promises to be an important tool for those working with MIP especially in the area of low level non-metal determinations. There has been a small renaissance in the use of cold vapour mercury generation into MIPs (86/1624, 8611692, 86/1934, 87/917).All but one of these reports (86/3934) employed amalgamation prior to evaporation of Hg into the plasma. Absolute detection limits were in the range 1.6 X 10-11 to 1.0 x 10-13 g which translated into relative detection limits in the sub-nanogram per litre range. It is interesting to reflect that there have been relatively few reports on this topic since the original work of Lichte and Skogerboe (see ARAAS, 1972,2, 21). The work by Watling (see ARAAS, 1975,5, 120) realised a most impressive detection limit of 10-17 g, which more recent workers have not approached by closer than four orders of magnitude. Another chemical vapour generation method which has been overlooked since its introduction by Alder et al. (see ARAAS, 1980, 10, ref.1712 and 1981, 11, ref. 536) is the liberation of the halogens or their hydrides from aqueous solution. Reports have appeared on the generation of Br2 (8611638), HBr and HC1 (871381). The latter work used a continuous flow generation system coupled to a 500-W He MIP. Considering that the analytical capability of the MIP for non-metals is well established, it seems incongruous that only five publications have appeared concerning this technique. The use of the MIP for gas analysis has been known for many years (see for example Broida, H. P., and Moyer, K. W., J . Opt. Soc. Am., 1952, 42, 37) but some applications reported this year are worthy of mention. McKenna et al. (87/612) used a low-pressure He MIP to analyse gas mixtures used in deep-sea diving by monitoring emission lines in the NIR.They found that the reduced pressure system was superior to an atmospheric pressure He MIP. Direct gas analysis has also been employed to determine volatile lead species in engine exhaust gases (87/1187). 2.2.4. Chromatography The use of MIPs for GC detection is well established and a detailed discussion can be obtained from recent reviews (87/90, 871518, 871673). The only reports included here, therefore, are those which were considered to cover novel developments rather than applications. Selby et al. (86/C1593) have investigated the use of the surfatron plasma as a chromatographic detector and com- pared its performance with that of the TMolo cavity. The surfatron has also been evaluated in conjunction with super- critical fluid chromatography (87/C707).The work reviewed last year (see JAAS, 1986,1, S/C263, 86/C1242) which used a Fourier transform spectrometer for the simultaneous determi- nation of Br, C, C1, F, H, N, 0 and S has now been published by Pivonka et al. (86/1988). Pyrolytic sample introduction, discussed in section 2.2.3, has also been used in conjunction with GC - MIP for empirical formula determinations of polyolefins and silicone polymers (87/C170). A detailed study of the production of vapourphase primary standards for organometallic compounds , for GC - MIP use, was the subject of a conference presentation by Greenway (87/C171). Michlewicz and Carnahan (87/C695) have described the nebulisation of LC eluent into a moderate power He MIP for the selective detection of halides.2.3. Direct Current Plasmas The relatively simple instrumentation and ease of operation of DCPs, in comparison with other plasma sources used for AES, are features that have continued to encourage the application of DCPs to a wide range of analyticalproblems. Some of those recently reported have been concerned with only one analyte, for instance with Be in biological tissues, fluids and rocksJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 181R (87/392), with B in tetraarylborates (8711501) and with P in steels or Cu alloys (86/1923). In this last study, it was necessary to use the P lines at 214.914 and 253.565 nm in steels and Cu alloys, respectively, to overcome spectral interferences from Fe and Cu. The multi-element capability of DCP-AES, however, was better exploited by the determination of Au, Ir, Pd, Pt, Rh and Ru in “sweep” samples after collection on copper(1) sulphide (86/1622), of Dy, Eu and Gd in uranium products (87111), and of various trace elements in bismuth germanate crystals (87/C1419), for which a detection limit of 0.2 p.p.m.was obtained for Cu and Cr. The versatility of DCP-AES stems from its ability to accept samples as liquids, solids or gases, and this topic was briefly discussed by Sparkes and Ebdon (86/1987). There has been a continued interest in the introduction of solids as slurries, a technique shown to be applicable to agricultural materials (871C196) and which has provided an improved method for detecting bone fragments in meat products (86/1990). Enhan- ced atomisation efficiency resulting from the addition of an EIE such as Li to the sample has been reported (87/C197) and the effect was attributed to an increased collisional temperat- ure in the DCP.A device for the laser ablation of solids into the DCP has been described by Mitchell et al. (861’1841). Linear calibration for Cu in steel, over the range 0.04-0.5%, was obtained using four NBS SRMs, but the method lacked the precision needed to compete with traditional methods of metal analysis. Sample introduction by electrothermal atomisa- tion appears to be potentially useful for small samples, as indicated by the analysis of Au-loaded algal cells (86/1903) and of aqueous Al, Cu and Mn solutions (86/1918). Brief reports on hydride generation for As (87/C214) and on the use of a “maximum dissolved solids nebuliser” (871C1353) were also noted.In common with all emission sources, the DCP is subject to matrix and interference effects and this received comment in the references noted above. A detailed interference study was reported by Smolander and Kauppinen (87/643) who investi- gated the determination of AsV in aqueous solution. They studied the effects of eight common acids and 12 cations on the As line at 193.696 nm, using an echelle monochromator with a resolution of 0.003 nm. The acids HOAc and HF caused strong modifications to the background spectrum and increased sensitivity the most, while HC1 and HN03 had the least effect. Precision was poor below an As” concentration of 0.75 pg ml-1, which limited the usefulness of the direct method. However, DCP-AES without hydride generation permits the simultaneous determination of other elements and could therefore be useful in some circumstances. A high- calcium matrix was observed by Qiu (871527) to enhance the intensities of some lines, but not of Mo, Se and V, and to have no effect on the axial distribution of temperature.In a comparison of sources for the determination of REEs in yttrium oxide, after dissolution in HCI, Daskalova et al. (87/C1006) noted that background intensity was greater in the ICP than in the DCP. Ion-chromatography (IC) was shown by Epler et al. (871C719) to be an effective technique for overcoming spectral interferences. In their case, an on-line chromatographic separation with a cation separator column was used to free the P line at 213.618 nm from interference by the Cu line at 213.598 nm, thus permitting the determination of P in phosphorised copper.The IC - DCP combination has also been used to determine As, P and Se (86/C1579). The speciation and structure elucidation of transition metal com- plexes, described by De Menna and Marasco (86/C1574), was another example of the capabilities of the IC - DCP combination. Good results have also been reported for determining methylmercury in fish by GC - DCP, using an inexpensive, home-made separation column (87/C563). One group of workers has reported three different ways in which laser-excited AFS can be used in conjunction with a DCP. In the first case, Hendrick et al. (86/1866) used a three-electrode DCP as an atom cell and although they obtained linear dynamic ranges of up to four orders of magnitude, they found that the detection limits for Ba, Ca, Fe, Na and V were poorer than could be obtained by AFS with ICP or flame sources.They attributed this to the high plasma background, scatter of droplets and the inefficiency of the sample introduction process. In the second case, a two- electrode DCP was used as the exciting line source for FAAS (86/1888). Instability of the DCP was held to be responsible for the poor RSD of about 10%. The final paper reported the use of laser-excited AFS (LAFS) as a diagnostic tool to study enhancement effects caused by EIEs in the DCP (87/89). Resonance fluorescence at the Ca 422.7-nm line, with and without added Ba, was used to study spatial atom-density profiles.They concluded that enhancement proceeds by modifying the rates of power distribution among the various plasma zones. The only detailed study of fundamental plasma processes reported was that by Miller and Zander (871123) who investigated the thermal pinch effect in the Ar DCP. They showed that the pinch can explain many of the formerly puzzling operational and spectroscopic features that dis- tinguish the DCP from a free-burning arc. Effects of an alternating magnetic field on analyte transport (861C1525) and of organic gases such as C2H2 and C3Hs on molecular formation reactions (861C1538) were discussed in conference presentations. General practical topics have not been widely reported. Closed-vessel microwave dissolution of steel was shown to be effective (86/1781), but this technique is not new and its use is not specific for DCPs.A further model has been suggested as the basis for fitting non-linear calibration graphs which may result from self-absorption (87/C712). The model assumed that a hot region, from which emitted light intensity was proportional to analyte concentration, was surrounded by a cool region in which the concentration of absorbing atoms was also proportional to the analyte concentration. The multiple- electrode configuration for DCPs discussed by Piepmeier et al. (87K757) was mentioned in this ASU last year (see JAAS, 1986,l 122R). Finally, the use of principal components factor analysis has been applied to the selection and evaluation of internal standard elements (8711257).3. FLAMES In recent years flame cells for analytical atomic spectroscopy have not undergone any revolutionary changes. Schrenk (86/1664) echoes this opinion in a useful condensed history of flame excitation sources which traces their development and application from the time of Georgius Agricola (1556) to the present day. This article is a must for all students of analytical atomic spectroscopy. 3.1. Fundamental Studies Lanauze and Winefordner (87/119) have reported the first use of photoacoustic spectroscopy (PAS) for elemental analysis in flames. They used an excimer-pulsed dye laser to excite atoms in an air - C2H2 flame. Photothermal signals were retrieved using a condenser microphone, box-car integrator, oscillo-182R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY7 OCTOBER 1987, VOL.2 scope and chart recorder. The only limit of detection given was 780 ng (3111-3 for Na. The authors felt that PAS in flames offered no advancement over the presently available spectro- scopic techniques for either elemental analysis or flame diagnostics because of its poor sensitivity and selectivity. The characterisation of flame processes such as soot nuclea- tion by photon correlation spectroscopy (86/1658), the quenching rate of the Na 3P level using sub-nanosecond time-resolved fluorescence (86/1661) and the spatial distribu- tions of various flame radical species by laser-induced Raman or two photon excited molecular fluorescence measurements (86/C1519, 86/1655, 86/1657) have been reported. These studies provided increased knowledge about the measurement and understanding of combustion processes and flame spectro- chemistry, but have not provided any immediate benefits for the practising flame spectroscopist.Takada (87/635) studied the effect of flame temperature on the relative atomisation efficiency of various elements. This was achieved using a heated spray chamber to increase the water vapour loading in the flame and therefore lower the flame temperature. Flame temperatures were measured using a zirconium oxide plate insert and an optical pyrometer. The author concluded that atomisation efficiency was strongly dependent on the flame temperature and on the dissociation energy of analyte species formed in the flame. Hieftje et al. (87/C220) have developed theoretical models of particle vaporisation in flames and plasmas which agree with experimental data.Childers and Hieftje (87/1255) conducted morphological examinations on solute particles collected on a variety of surfaces at different positions in a laminar air - C2H2 flame. The investigations revealed structural changes in the solute particles which were related to the mechanisms of desolvation and vaporisation. Electrostatic aerosol modulation (EAM) has been utilised to measure flame gas rise velocities, which were related to analyte residence times. 3.2. Interference Studies Skogerboe and Butcher (86/1610) used dual matched nebu- lisers which allowed the introduction of K as the analyte and Cs as the concomitant in separate or the same droplets. They re-examined the enhancement of the K absorption signal in the presence of varying molar ratios of Cs.Their results showed that with both systems the enhancement reached a maximum at the same Cs to K molar ratio. However, the magnitude of the enhancement was significantly greater when K and Cs were introduced in the same droplet. This was attributed to improved aerosol transport, a conclusion which they suppor- ted with measurements of droplet size distributions. Kantor (8611727) has published a study on the volatilisation effects of Al, La and Sr salts on the determination of Ca by FAAS. He found that Lac13 and SrC12 act as releasing agents for Ca by preferentially promoting the evolution of CaC12 vapour rather than the formation of a thermally stable calcium aluminate. Mostafa and Kabil (86/1890) characterised and eliminated various cationic interferences on the FAAS determination of Pt by the continuous titration addition of n-butylamine.They proposed that the releasing effect resulted from the formation of a volatile Pt - amine complex. Hydrazine and nigrosin have been evaluated with FAES with a view to improving desolva- tion and atomisation efficiencies (87/428). The latter additive completely eliminated the interference of phosphate on Ca. Improvements were observed with both reagents and this was thought to have resulted from enhanced vaporisation. Read- ers interested in the study of interferences and releasing agents should also consult references 86/1703, 86/1767, 8611831, 8716 and 87/C190. Lakatos and Lakatos (87/C1081) presented a detailed study on the interference eflects of high-viscosity polymers on the determination of trace elements by FAAS or FAES.Their work was concerned with partially hydrolysed poly- acrylamides and they found that the matrix problems could be eliminated in strongly acidic media with the addition of multivalent cations or an oxidant, the latter being preferred for routine analysis as the suppression was independent of polymer type. Zhang et al. (87/265) studied the effects of various cationic surfactants on the FAAS signal for Cr. They concluded that formation of an ion pair between the surfactant and Crz072- ion, which was more easily atomised than an oxide species, gave rise to the greater signal. Readers interested in the application of emulsions and surfactants should consult references 86/1879, 86/2032, 87/1086 and 87/1214.Canals et al. (87/947) investigated the effect of F- ions on the flame molecular emission of boron species in methanolic solutions. They found that increased F- levels decreased emission from the B species in the flame due to the formation of methoxy fluoroboric esters which were thought to have lower volatility than methoxyboric esters. Omenetto and Winefordner (86/1181) have published an excellent and very practical review on methods of correction and elimination of scattering interferences observed in FAFS. 3.3. Instrumentation Krupa and co-workers (86/C1563, 87/645, 87/965, 8711261) have reported a novel flashback resistant laminar flow burner capable of sustaining flames using various fuel and oxidant mixtures.The authors claimed that this burner could be applied to all forms of analytical flame spectroscopy and combustion diagnostics. Measured temperatures for various flames ranged from 1190 to 3470°C and the designers have offered to supply detailed drawings upon request. Another development in burner design was the tandem flame which consists of a pair of needle burners directed towards either end of a 5- or 10-cm long conventional AAS slot flame. Signal enhancement (86/C1534), interference studies (86/C1556) and metal oxide dissociation (87/C700) were discussed. Advan- tages from this type of atom cell were thought to have resulted from the redirection of diffused analyte atoms from the outer edges of the primary flame back towards the absorption zone plus the secondary atomisation of refractory species by the new fuel supply.While there were no major advances reported for conti- nuum-source AAS over the past year, two informative review articles on the topic of instrumentation have appeared (87/57, 87/110). A cylindrical (“see through”) HCL, where the atom population within the cathode is modulated by pulsing the lamp power supply has been used for selective line modulation (871C795). This resulted in higher modulation frequencies and a less complex optical system. Second derivative wavelength modulation has been evaluated with FAES and FAFS to improve the SNR (86/1876). When applied to the analysis of copper alloy, the attainable detection limits did not reflect the improvement in SNR. A DCP was used as a line source for FAFS (8611888) which showed it to be free from large scattering interferences due to the relatively low spectral line intensity.Further interest has been shown in the use of Smith - Hieftje background correction with FAAS (86/C1557, 87/C562, 87/C734) for trace element determinations in gas turbine fuels. In a continuing series of papers on the precision of FAAS, Steglich et al. (86/1783) reported a comparison between double- and single-beam instrumentation. Superior reproducibility was achieved with the latter due to the higher noise level of the double-beam instrument. 3.4. Chemometrics In parallel with last year’s review on this topic, a number of reports appeared concerned with calibration curve fitting and calibration practices. O’Haver and Kindervater (86/C1568,JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 183R 86/1820, 871C713) have developed a method for producing extended linear calibration graphs for continuum-source FAAS. The principle involved ensemble averaging of the transmission profile of the analytical line and fitting it to a computer model that takes account of inherent line shape, background intensity, instrumental broadening and stray light. This produced what the authors defined as an intrinsic absorbance or the absorbance which would have been observed in the absence of instrumental effects. A plot of intrinsic absorbance versus analyte concentration (Mg) gave a linear calibration over four orders of magnitude. Bysouth and Tyson have reported the results of an extensive survey on calibration techniques used in FAAS (871C184).These workers have also suggested novel alternative methods of calibration based on flow injection (FI) (87/C185, 87/C541, 87/C708, 87/932) and peak-width measurement for extended calibration ranges (871389). Further information on the suitability of commercial curve fitting algorithms has appeared (86/1654,86/1889). Montiel and Welte (87/386) have reviewed the principles and limitations of the method of standard additions with respect to FAAS. Liu and Li (87/5) have described the use of non-linear standard additions with various mathematical functions to characterise the relation- ship between absorbance and concentration. Improvements in detection limits for FAAS have been achieved with ensemble summation of signals obtained using liquid microsample injection (86/1817).Buell(87/964) claimed that the detection limits for 69 elements with repetitive optical scanning in the derivative mode for FAES were the best reported to date. Kushita (87/378) reported an improvement in the conven- tional method for determining the isotopic composition of Li by the use of ultimate absorbance ratios derived by extrapola- tion of the calibration curve. 3.5. Sample Introduction 3.5.1. Nebulisers and spray chambers A description of the improved pneumatic nebuliser described by Sturman last year has now been published (86/1871). Stupar (87K1087) presented a paper on the use of a dual-nebuliser system for FAAS which consisted of a Babing- ton and a conventional nebuliser.With this configuration the author claimed that the use of ionisation suppressants or releasing agents was not required. O’Grady et al. (86/1676) have published further work on nebuliser suction (see also ARAAS, 1984,14,32). In this study signals from the pressure transducer and the FAAS signal were fed into a microcomputer to obtain real-time indication and correction of the drift in aspiration rate. However, it was found that this continuous correction technique gave poor precision due to changes in aerosol characteristics. These workers have now published their study on impaction devices in spray chambers (86/2011). Ham and Willis (86/1913) produced an extensive study on this subject,which is the fourth part of their series on atomisation problems in FAAS. The authors concluded that the most effective way to reduce volatilisation interferences is to limit the particle size and that this is best accomplished by impaction on a plane surface.This always resulted in a decrease in signal, although the SNR remained essentially unchanged. For several well known interferences, limiting droplet diameters were quoted for the air - C2H2 flame. Willis (87/922) subsequently published a critical review of the use of aerosols in flame spectrometry in which he assessed the merits of nebuliser systems in terms of three criteria, viz.: (i) nebulisation efficiency, (ii) drop size distribution and (iii) fluctuation of the analytical signal. A critical evaluation of the techniques used to measure the above criteria was also given. Prudnikov and Shapkina (8611729) have investigated the nebulisation effects of solvent vaporisa- tion and element redistribution for various fractions of the aerosol. Other workers (86/1775) found that the distance between the nebuliser capillary tip and the impact bead was critical for high dissolved solids application. Skogerboe and Freeland published a comprehensive study on the experimen- tal characterisation of aerosol production (86/1910, 8611911).A third paper discussed the effects of solution composition on the physical characteristics of aerosols (86/1912). Examination of solid particles produced by flash evaporation of droplets revealed that they tended to be hollow spheres some of which contained other spheres. 3.5.2. Atom-trapping techniques Huang and Luo (87/104, 87/1449) studied the effect of several instrumental parameters including flame stoicheiometry col- lection time and tube material on the determination of Cd and Pb.They reported characteristic concentrations of 5.4 X 10-5 and 7.2 x 10-4 p.p.m., respectively, which were two orders of magnitude superior to those obtained by normal FAAS. Their application of the technique to a broad range of matrices emphasised its utility. Other reports included the determina- tion of Cd in CaC12 soil extracts (86/1854). 3.5.3. Flow injection techniques In a review, R6iiEka (87/669) noted that of the 800 papers published on FI, 70% used spectroscopic detection and within that group the fastest growing areas were FAAS and ICP-AES. Other workers have also reviewed the subject (86/1680, 86/1880, 87/1251) (see also JAAS, 1986, 1, 139R).The above articles emphasised the need for greater fun- damental understanding of FI - FAAS from which improved instrumentation and methodology would evolve. Appleton and Tyson (86/1867) have studied the influence of detector response on FI - FAAS and found that it contributed appre- ciably to observed signal characteristics. In the same paper, they developed a semi-empirical model of nebuliser perfor- mance to aid in the characterisation of the actual system. While exact numerical agreement between observed and predicted results was not obtained, the usefulness of modell- ing techniques was illustrated. Harnly and Beecher (86/1915) measured SNRs for FI-FAAS at reduced sample flow-rates and constant nebuliser gas flow-rates and compared the results with conventional FAAS.The lower sample flow-rates gave improved nebulisation efficiencies by factors of 4-12. Peak area SNRs were superior to peak height SNRs for FI, but never exceeded those of conventional FAAS. Reports of ion-exchange FI - FAAS have again appeared for the determination of metal - fulvic acid complexes (861C1549) and Cd in biological samples (86/2204). Gallego and co- workers have used FI - FAAS for the indirect determination of anions in solution. Continuous liquid - liquid extraction with a CUT - neocuprine complex for nitritehitrate was reported (86/1950). They also fabricated a continuous precipitation FI manifold for the determination of oxalate, chloride and hydroxide with limited success (87K192).3.5.4. Chromatographic detection During the past review year, no novel configurations for interfacing either GC or LC instrumentation to FAAS have been developed. A review on the subject of coupling GC to atomic spectroscopy has been published (87/673). Detection by FAAS has been reported for indirect ion- exchange chromatography (86/C1532) where a Li eluent was monitored for the exchange of monovalent cations and Mg eluent for divalent cations. Although offering a simplified method of detection, both the sensitivity and selectivity are less than those achieved by conventional techniques. Hill et al. (86/1649) have published their critical appraisal of interfaces184R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 for HPLC - FAAS. Wu and Robinson (86/1755) continued their work with ultrasonic nebulisers as interfaces for HPLC (see also JAAS, 1986, 1, 140R) and have reported the direct determination of Zn and Mg in body fluids.Those interested in further applications of HPLC - FAAS should consult the following references: 86/1847, 86/C2038, 87/C198, 87/693 and 87/9SO. 3.6. Applications of Lasers The period covered by this review has not seen an increase in the use of lasers. There has been, however, an increase in the use of atom cells other than flames and, in particular, the use of the electrothermal atomiser for atom production for laser-excited atomic fluorescence spectrometry (LAFS). Flames continue to be used as atom sources for laser-enhanced ionisation (LEI) studies, though the advantage of the ICP for laser-induced ionic fluorescence spectrometry, because of reduced quenching of the excited levels, has been noted (8~1791).The first reports of laser-excited coherent forward scattering have appeared, though one group (8711223) were not encouraged by the initial results. Several conference presentations have provided an over- view of the use of lasers for spectrochemical analysis (87/ C1330, 86/C1479, 87/C1218, 87/C1327, 87/C144). These included excitation of molecular fluorescence and the study of solute particle vaporisation as well as diagnostic studies in plasmas and flames. The possibility of using laser-excited molecular fluorescence has been described (87/C144) for the determination of non-metals via the formation of stable diatomic molecules in an electrothermal atomiser.There have been a small number of reports of the use of laser-based techniques for the analysis of real samples, but there are some formidable problems to be surmounted before such techniques move out of the research laboratory into general analytical laboratories. These problems involve those inherent in the laser itself (Hieftje, G. M., JAAS, 1986, 1,4) as well as practical difficulties due to most laboratories’ stringent codes of practice for safe operation of lasers. On the other hand, the unsurpassed spectral selectivity and high radiant flux of laser sources ensure a bright future for laser-based techniques. Also of interest is the use of laser ablation for solid sampling, mainly for ICP-AES (see section 2.1.2) and ICP-MS (see section 2.1.6).3.6.1. Laser-excited atomic fluorescence spectrometry (LA FS) An ideal atom cell for AFS would produce only ground-state atoms with no mechanisms for quenching the excited states. It is therefore not surprising that there has been more interest recently in LAFS with electrothermal atomisation than with flames. Michel et al. (87/C809) described an electrothermal atomiser modified by drilling holes through the graphite contact rings and furnace tube perpendicular to the AA optical axis. This allowed measurements to be made in the transverse mode (laser beam directed through the drilled holes) or in the axial mode (laser beam directed along the AA optical axis). Detection limits for Co, In, Pb and T1 were reported to be 0.5, 0.08, 0.007 and 0.1 pg, respectively.Atomiser design has also been discussed by Dittrich (87/523) who described modifications to two commercially available atomisers (Beckman 1268 and Perkin-Elmer HGA-500-EA3 types). Interferences in the determination of Pb were found to be reduced compared with those obtained when a home-made rod atomiser was used. The relative performance of AAS and LAFS in the determination of Cu, Ir, Pb, Pd, Rh, TI and V has been reported (87/C1052). A comprehensive comparison of various atomisers and atmospheres has been made (87/1203). This study involved various combinations of a graphite rod, a graphite cup, a tantalum-foil liner and tantalum carbide and pyrolytic graphite coating. Hydrogen - argon and Ar atmos- pheres were employed at both normal and reduced pressures.Detection limits for Al, Cu, In, Li, Mn, Pb, Pt and Sn were found to be in the pg to sub-pg range with linear working ranges varying from three to seven orders of magnitude. A nitrogen-pumped dye laser was used by Japanese workers (87/1212) to excite Pb fluorescence from a carbon-cup atomiser. In addition to a PMT detection system, a vidicon system was used to measure the fluorescence spectrum. A detection limit of 28 fg was claimed. The number of elements capable of being determined by ICP-LAFS has increased with the demonstration of AF signals from Ag, Au, Hf, Ir, Nb, Pd, Pt, Ru and Ta (864875). Detection limits in the range 1.3-58 ng ml-1 were found with linear dynamic ranges of four orders of magnitude (except for Au and Hf). Disappointingly the detection limits were poorer than those of FAAS for Ag and Au, and comparable to those for ICP-AES.The use of a tunable dye laser to study Zeeman-effect background correction for ETA- LA FS has been reported (87/C222,87/C808). Atomic fluorescence line profiles for Co, In, Pb and T1 were obtained with a resolution of 0.5 pm. Curvature of the calibration curves with and without Zeeman- effect background correction (ZBC) was explained by broadening of the fluorescence and Zeeman component profiles at high concentrations (100 p.p.m.). Detection limits for these elements with and I without background correction were also reported (87/C807). Linear dynamic ranges of five to six orders of magnitude were obtained. Bol’shov et al. have measured Co and Cu in plant materials and soil extracts (87/260) and Co in high-purity tin, vegetation and quartz (87/C1122, 87/126).In this latter study, the use of a reduced pressure atomiser (10-2 Torr) was shown to be beneficial in reducing matrix interferences although it pro- duced significantly poorer (by a factor of 100) detection limits than atmospheric pressure atomisation. All three sample materials were analysed directly by introducing 10-mg samples into the furnace. One of the attractive features of the use of a laser to excite atomic fluorescence is the possibility of saturating the excited state. In principle, under saturation conditions, the fluores- cence intensity is independent of changes in laser intensity, and of quenching processes. As the fluorescence intensity is a maximum under saturation conditions, the best SNR should be obtained.Alkemade (86/1993) has provided both a review and a tutorial discussion of the use of saturation curves in analysis and diagnostic studies. He concluded, however, that for analytical work any problems should be overcome by the use of carefully selected standards and attention to the reproducibility of the atomisation, excitation and observation conditions. The paper is thus mainly of interest for the cautionary words concerning their use for diagnostic studies. These included, for example, the methods described for determining the absolute line intensities emitted from He or Ne discharge plasmas (87/651) and for flame studies using a single-shot method (86/1662). Factors affecting detection limits for d.c. plasma LAFS have been studied (864866). Values for Ba, Ca, Fe, Na and V were found to be in the range 3-72 ng ml-1 with linear dynamic ranges of four orders of magnitude for Ba and Ca. The suggested limiting factors were the high plasma background, scatter from sample droplets and inefficiency of the sample introduction process. 3.6.2. Laser-enhanced ionisation ( L E I ) There are still very few reports of the application of LEI to the analysis of real samples. A review, in Chinese, (8711195) citing 38 references, covered principles, instrumentation and appli- cations to trace analysis. A discussion of the relative merits of LAFS and LEI utilising both single and double resonance steps has been presented (87/672). It was concluded that the best sensitivity should be obtained from double resonanceJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 185R ionic fluorescence in an ICP. Laser-excited AFS and LEI have also been compared (87/C804) with respect to signal measure- ment techniques. A Cu-vapour pumped dye-laser system was used and signal processing involved either modulation of the pulsed-laser output with subtraction of noise, or band width limitation to reject high-frequency noise which allowed amplification of the signal only. Simultaneous fluorescence and ionisation measurements both in flames and in plasmas have been reported (87/C802, 871C803). The advantages of such a combination lie in the possibilities for the identification of the excitation - ionisation processes occurring, as well as for following the time decay of a particular ion.A two-step excitation - ionisation mechanism of Sr was studied by monitoring the fluorescence signal resulting from the first excitation step, which decreases as the second step is tuned to resonance with a higher energy level. Thus “fluorescence dip spectroscopy” is the continuous moni- toring of this fluorescence while scanning the second transition step. The simultaneous monitoring of the ionisation signal was shown to provide information about the state reached by the second step, and about the strength of the transition. Strontium ions were excited at 421.552 nm and ionic fluores- cence observed at 407.771 nm. Two distinct decay modes were noticed, a fast decay (58-ns time constant) was attributed to ion chemistry whereas a slow decay (57-ps time constant) was attributed to ion - electron recombinations.These conclusions were reached after perturbing the system by the addition of caesium to increase the electron partial pressure. The complex LEI spectrum of Sr in an air - C2H2 flame has been studied (86/1611) and the occurrence of two-photon absorption when only one laser is used was reported. The estimated radiant flux at the beam waist varied from 20 to 100 MW cm-2. This raises the problem of spectral interference when analysing real samples because of the large number of multiphoton excitations which might occur. The processes of LEI (transitions to Rydberg states close to the ionisation limit) and photoionisation (transitions to continuum states) have been compared (87/513) for Li, Na and TI and similarly it was concluded that for real samples a significant increase in background noise will be obtained if the sample contains high concentrations of easily photoionised elements and short- wavelength light is used.The choice of transition has been discussed (87/C806) in terms of the transition probability, the matrix components and their non-resonance ionisation prob- ability, and the flame background ionisation magnitude. The superior performance of the two-step resonance excitation process in terms of selectivity has been clearly demonstrated. In the determination of Mg in sodium (87/387), spectral interference was decreased by a factor of 1300 over the one-step process without loss of sensitivity. Detection limits for 39 elements by flame LEI spectroscopy have now been reported (87/C1331) of which 23 are at or below 200 pg ml-1 and 10 below 50 pg ml-1.This presentation also included a description of LEI detection for liquid chromatography providing possibly the first report of the use of the flame ionisation detector in HPLC. A stepwise excitation of Zn (87/1265) yielded detection limits down to 1 ng ml-1. The determination of Cs, K, Na and Rb in water, high-purity alkali metals and their salts and polymeric organosilicon compounds, using an instrument described previously (ARAAS, 1983, 13, ref. 1002), has been reported (87/1484). In addition to conventional nebulisation, two other sample introduction techniques were used. These involved thermal evaporation of material placed directly on to the detector cathode and evaporation from an electrically heated W loop in the flame.Apart from flames, a variety of atomisation devices have been employed. Good precision and a wide linear dynamic range (five orders of magnitude) were reported (87/1266) for ETA. Laser-enhanced ionisation was used for diagnostic monitoring of SiH in a glow discharge for chemical vapour deposition (87/36). Plasma sources included a He micro-arc (86/1706) in which Na was determined with a detection limit of 3 ng, and an Ar ICP (8611891) in which single-photon, two-photon and stepwise modes of excitation were used. Poor analytical sensitivity was obtained, but such techniques are useful for diagnostic studies. The possible analytical applications of the double-resonance ionic fluorescence mentioned above have been studied for Ba, Ca, Mg and Sr (86/1791).Both a flame and an ICP atom source were used with the ICP proving superior and giving detection limits of 1, 0.007, 0.05 and 1 ng ml-1, respectively. These values were obtained by monitoring at a wavelength different from that of the second transition. Such a process should be referred to as “double-resonance non-resonance ionic fluorescence” but “two-step non-resonance ionic fluores- cence” is preferred. The non-resonance mode of detection avoids problems arising from scattering of the second laser light. 3.6.3. Other studies The use of a laser source for coherent forward scattering (CFS) spectrometry has been reported (86/C1558, 87/1223). These studies exploited the Voigt effect, i.e., the rotation of the plane of the polarisation of the light at the resonance wavelength when the atoms are located in a transverse magnetic field (the use of a longitudinal magnetic field gives rise to the Faraday effect).Both flames and electrothermal atomisers were used (see also section 4.6) and the advantages of laser sources over hollow-cathode or Xe-arc lamps in terms of intensity (the CFS signal is proportional to source intensity) and coherence were discussed. The determination of Be in beryllium-copper alloys by laser-induced breakdown spectrometry (LIBS) has been repor- ted (87/35, 871’481). A Q-switched Nd: YAG laser was operated at 80-90 mJ pulse-1 at a 10-Hz repetition rate and the instantaneous irradiance on the surface was calculated to be about 4 X 108 W cm-2.A detection limit of 2 p.p.m. was estimated and the excitation temperature was determined from Boltzmann plots of Cu I and Cu I1 to be about 13 850 K at 1 ps into the plasma lifetime, assuming LTE. Factors affecting the analysis of steels by LIBS have been studied (87/480) including lens-to-sample distance, laser-pulse energy (Q- switched Nd : YAG) and position of the imaging lens. Calibra- tions for Cr, Mn and Si were given together with an evaluation of accuracy and precision. Two reports of LIBS of aqueous solutions have appeared (87/C557, 87/C756), both using a Nd : YAG laser. The first of these studies used an echelle spectrometer and the sample was contained within filter-paper or cotton-wool. Laser power was 600-700 mJ pulse-’ at a 2-Hz repetition rate.The plasma characteristics were compared with those of a DCP. Emission intensities indicated a temperature of 40000 K and detection limits of about 100 p.p.m. were obtained. Ceramic and glass samples were also studied, with similar detection limits for Cu, Mn, Ni and Sr in the solid as were obtained in solution. The use of an acousto-optic beam deflector has been reported (87/653) for obtaining spatially and temporally resolved AA profiles of transient events. The technique was demonstrated in a study of atom formation in a laser- generated plume from a sodium tungstate surface. Similar information can be obtained from cross-beam polarisation with a pulsed dye laser (87/955). Sodium in an air - C2H2 flame was monitored. Also of interest for flame diagnostics was a report of trace gas detection by laser intra-cavity photothermal spectroscopy (86/1663).Laser-excited luminescence for the direct qualitative and quantitative analysis of scheelite ores has been reported (87/C1399).186R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 4. ELECTROTHERMAL ATOMISATION A survey of the developments in ETA provides a good example of the nature of modern analytical chemistry. Not only are developments taking place in instrumentation, such as furnace designs, use of platforms and background correc- tion methods, but a greater understanding of the chemistry occurring in such atomisers is being sought. This latter aspect provides a considerable challenge for the research analyst as the basic instrumentation only yields a limited amount of information.In essence, these are: (i) how the absorbance (of a known atomic species or unknown molecular species) varies with time. and (ii) rather inaccurate relationship between the temperature of the atomiser and time. As is often the case when complex systems are investigated, many of the experimental approaches are based on the strategy of perturb- ing the system in a known way and following how the measurable performance parameters change. Although many research groups around the world are actively investigating all aspects of ETA, there is a growing concensus that atomisation into an isothermal region is desirable and that, for the analysis of real samples, a reliable background correction system is needed.Some of the leading workers in the field have summarised recent developments (8611471, 86/1908, 86/2005, 87/C221,87/C724,87/C1154) and have speculated on the role of emission techniques, the possibilities of simultaneous multi-element determinations and of absolute analyses. Much of the work reviewed here is motivated by the desire to reduce interferences when real samples are analysed and thus the sub-divisions of this report are somewhat arbitrary. 4.1. Atomiser Design Various atomiser designs have been proposed for achieving isothermal atomisation conditions. One approach is to use a contoured tube (87022, 87/424). The first of these reports described a variety of tube designs and discussed the difficul- ties of making reliable temperature measurements along the length of the tube wall and of measuring gas temperatures.The authors required this to obtain experimental data against which to test the results of model calculations. Six elements, in order of decreasing volatility (Pb, Sn, Cu, Al, V and Mo), were studied in eight commonly occurring matrices, nitric, phosphoric, sulphuric and hydrochloric acids (500 pg ml-1 of the anion) and calcium, magnesium, potassium and sodium nitrates (500 pg ml-1 of the cation). The use of a contoured tube, machined to give a 2O-pl capacity recess in the inner surface at the tube centre, has produced improved precision and sensitivity for the determinations of B and U (87/423). A side-heated graphite cuvette with integrated contacts (87/370) to provide spatial homogeneity of isothermal condi- tions has been described. It was found that with non-volatile elements, lower atomisation temperatures could be used than with a Massmann furnace while reducing problems associated with signal tailing, condensation and memory effects.The use of a L’vov platform gave a further improvement in perfor- mance. A graphite-cloth ribbon placed inside a conventional graph- ite furnace was found to both enhance the sensitivity and reduce heavy metal interferences in the determination of As (87/288). This was attributed to condensation of As on the ribbon due to the temperature lag during the drying and ashing stages and to the formation of interlamellar compounds of As with graphite. The ribbon, made from poly- (acrylonitrile), was cut into pieces 1.5 x 25 x 0.3 mm (mass about 5 mg) which were placed longitudinally inside the graphite tube.The best results were obtained with a pyrolytic graphite coated tube and a nitric acid matrix. Rettberg and Holcombe have now published (87/117) their work on the second suface atomiser discussed previously (see JAAS, 1986, 1, 144R), and details of the modified furnace (Varian GTA-95) with gas-cooled tantalum insert were given. After sample introduction and drying in the conventional manner, the temperature was slowly ramped (15-30 s) to a value in excess of the vaporisation temperature of the analyte. During this time the analyte is “transferred” on to the tantalum surface. The furnace temperature was then raised to the final atomisation temperature and then the coolant gas flow to the insert shut off.The work aimed to avoid the use of matrix modifiers and it was demonstrated that, in the determination of Al, Ca, Pb, Sn and T1 in halide and sulphate matrices, matrix to analyte ratios of 104 could be tolerated. Furnace lifetimes of several hundred firings were obtained. The same workers have also investigated the possibility of using their system for the direct analysis of solids including fly ash, river sediment and citrus leaf reference materials (86/2027). Using peak-height measurement and calibration with aqueous standards, recoveries varied from 81 to 127%. The work on probe atomisation by the Strathclyde group has been collected and reviewed (8611647, 87/318, 87/C187). The important design features discussed included: shape and dimensions, material of construction and the direction of entry into the atomiser (either through the tube wall, so-called “front entry,” or in the open tube end, so-called “end entry”).Both “flat” and “tubular probes” were described and evalu- ated. In a detailed study of the latter (87/616), it was reported that better precision was obtained due to the better confine- ment of the sample solution within the tube and reduction in high-temperature diffusional losses. As the characteristic masses for volatile elements are similar for the two configura- tions, the large sample volume capacity of the tube probe (40 pl) should lead to lower detection limits. However, its greater thermal mass appears to lead to poorer detection limits for involatile elements as indicated by sensitivity reductions of three- and four-fold for V and Cr, respectively.The probes were made of pyrolytic graphite and had lifetimes compatible with normal atomiser tube lifetimes. The use of a W probe has also been reported and accurate results were obtained for the determination of Mn in urine (87/1182). The use of the probe as a mechanistic tool has been pro- posed (871C822). In this study, the interference of copper, magnesium, sodium and zinc chlorides and perchloric acid on the formation of Ag, Ga, Mn and Pb atoms was studied by following both atomic and molecular absorptions (e.g., such as those due to Ga, GaCl and GaO). Vapour-phase tempera- tures were calculated by the two-line absorption method using Ga, Ni and Pb as the thermometric species. 4.2.Atomisation Surface There have been several comparisons of the various carbon surfaces from which samples are atomised presented during the period of this review. Many of these have reported on the findings of Welz’s research group, which together with the late Professor Ottaway’s group has been particularly active in this field. The former reported a comparison of uncoated poly- crystalline tubes, pyrolytic graphite coated tubes (both of standard construction), tubes with a thicker pyrolytic graphite layer, glassy carbon tubes and totally pyrolytic graphite tubes (all of experimental design), together with L’vov platforms made of totally pyrolytic graphite (86/C1547,87/C1160). They found that the standard pyrolytic graphite coated tubes with a L’vov platform had long lifetimes and good analytical perfor- mance, even with aggressive matrices, for volatile and medium-volatile elements.Higher sensitivity for refractory elements (Mo, Ti, V) was obtained from wall atomisation. The use of the thicker pyrolytic graphite coating extended the tube lifetime from about 300 to 600 firings. The glassy carbon tubes were found to be resistant to aggressive matrices andJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 187R long lived provided a temperature of 2600 "C was not exceeded. Above this temperature very rapid degradation of the tube occurred. It was concluded that the thicker coated tube was more suitable for routine analysis than the glassy carbon tube. Studies of atomisation surfaces using a scanning electron microscope have been reported (87/130, 87/364).Over the lifetime of a pyrolytic platform in a polycrystalline tube (1000 firings at 2650 "C for non-corrosive matrices, 500 firings for a corrosive matrix), substantial deposition of graphite on the platform was observed. Although this provided a second coating, no problems with intercalation were encountered. For carbide-forming elements, it was observed that the sensitivity depended on the quality of the pyrolytic graphite coating of the tube into which the platforms were inserted. The second of these two reports (87/364) contains a review (26 references) of morphological studies of atomiser surfaces. When peak shapes and appearance times were compared (87/391), it was found that uncoated tubes showed shifts in peak maxima,peak broadening and higher atomisation tem- peratures compared with coated tubes.These shifts were interpreted as an adhesion of metal atoms to active sites on the carbon surfaces. For certain refractory elements such adhe- sion could be identified with chemical reaction. The conclu- sion of the previously mentioned studies, namely that the best atomisation efficiency is always obtained in a pyrolytically coated tube (regardless of atomisation mechanism), was confirmed. There is not, as yet, universal agreement concerning such findings. It has been reported that the combination of a pyrolytic graphite coated tube and glassy carbon platform could be the best compromise (871413). Differences in the atomisation characteristics of Ni in a variety of tubes have been observed (87/C1116).Pyrolytic graphite, uncoated and tantalum-foil lined tubes were compared for the determination of Be in rocks (87/524). It was reported that all three performed satisfactorily with negligible matrix effects, though sufficient interferences from 13 metal ions on Be at the 3 p.p.b. level were encountered to rank the tubes in order of decreasing interference levels as pyrolytic graphite coated > uncoated > tantalum-foil lined. A comparison of uncoated, pyrocoated and totally pyrolytic graphite tubes has been made (86/1614). Lead, Mn and V were used as the test elements, though the effect of different matrices was not evaluated. The tube performance characteris- tics were based on the total atomisation firings, on the total length of time of all heating stages, on the weight loss (expressed as mg s-1 of atomisation lifetime), on change in measured tem- perature during tube lifetime and on the sensitivity for the three test elements.The totally pyrolytic graphite tubes were found to be more durable than the other types of tube, but this was a function of thickness of the tube wall.. A tube with wall thickness 720 pm lasted longer than one of 400 pm. The totally pyrolytic graphite tubes gave equivalent sensitivity for Mn, increased sensitivity for V and slightly poorer sensitivity for Pb compared with the other tube types, but the signal magnitude was more consistent throughout the tube lifetime. The tantalum-coated tube was found to give the poorest sensitivity. The authors considered it probable that totally pyrolytic tubes would eventually become available for a range of atomiser designs. There has been considerable interest in the evaluation of the performance of totally pyrolytic graphite tubes.In one study (87/C203), it was found that for refractory elements and matrices such as perchloric acid or iron(II1) chloride, the analytically useful lifetime was considerably shorter than the physical lifetime. The surface with which the atoms came into contact after volatilisation had a greater influence on the observed signal than the surface from which the element was originally vaporised. The poor performance of totally pyroly- tic graphite tubes with perchloric acid matrices has been confirmed (87/C223). This study also found that although the characteristic mass for the totally pyrolytic tubes in terms of peak area was about the same as that of the pyrocoated tubes, the values were only half in terms of peak height.To some extent this latter finding has been contradicted by Brown and Lee (871419). A comparison of electrographite (normal material), pyrocoated and totally pyrolytic graphite tubes on the basis of peak profiles and appearance times of volatile (Cd, Pb), medium-volatile (Al, Cr, Mn) and refractory elements (Mo, Pt, Ti, V) showed improved sensitivity for the medium-volatile and refractory elements. This was thought to be due to the increased heating rate of the totally pyrolytic graphite tubes. Together with the reduced appearance times, the net effect was increased tube lifetimes as shorter atomisa- tion times were possible.For the determination of lanthanoid elements (Dy, Er, Eu, Gd, Ho, Lu, Nd, Pr, Sm, Tb, Tm and Yb) a tantalum surface was found to be superior to a tantalum carbide surface (87/103) for Tb, whereas for Eu and Sm no beneficial effect was observed. A variety of mutual interference effects in 1% hydrochloric and nitric acid media were studied and it was found that Eu, Sm, Tb and Yb could be determined directly, Dy, Er and Ho by the method of standard additions and Gd, Lu and Tb only with very poor accuracy. Aluminium in serum has been determined (87/1486) by the combination of low-temperature plasma ashing and atomisa- tion from a "molybdenum treated pyrocuvette. " Standard additions were used to determine A1 at the ng ml-1 level.A variety of carbide coatings have been investigated for the determination of Eu, Sc, Tb and Yb (87/C201) and a variety of enhancement effects observed. For Sc and Tb, pyrolytic graphite coated tubes were better than any of the carbide coated tubes (particularly tungsten and zirconium carbide coated tubes which completely suppressed the signals). A detailed study of carbide surfaces using scanning electron microscopy (SEM) and X-ray diffraction (XRD) has been made (86/2014). Coatings were prepared by placing the tubes in the liquid chlorides (MoC15, TiC14 or WCl6) under reduced pressure followed by a 24-h soak in water to hydrolyse the chloride to the hydroxide, heating for 20 min at 120 "C and 10 s at 500 "C, to produce the oxide, and finally at 300 and 1800 "C to produce the carbide.X-ray diffraction confirmed the formation of the carbide, but also indicated the presence of oxide on the titanium- and tungsten-treated surfaces and of multiple carbide species on molybdenum- and tungsten- treated tubes. Small particles of a discrete carbide phase were found by SEM on the titanium-treated surfaces. The tubes so prepared were found to last longer than conventional graphite tubes and gave better sensitivities for the carbide-forming elements and, in general, to be similar to carbide-coated tubes produced by other procedures. It was suggested that the main effect of the carbide was to reduce the tube porosity. A thorium-treated L'vov platform (soaked in 10% thorium nitrate solution) was compared with a pyrocoated platform for the determination of A1 (86/1919).The "thorium coating" reduced peak broadening and increased the maximum ashing temperature by 300 "C. Peak-area precision and sensitivity were comparable, and satisfactory performance was still observed after 500 firings at 2450 "C. The mechanism of the improved performance was not discussed in detail, but the initial suggestion was that as thorium oxide is more refractory than magnesium oxide (magnesium nitrate has been shown to be an effective modifier for aluminium), a thorium modified platform should show a similar behaviour. For the determina- tion of Si in human serum, pyrolytic graphite coated and molybdenum carbide coated tubes were suitable (87/97). Tantalum- and tungsten-treated tubes were found to be less so.In contrast, another report (87/477) found tantalum carbide tubes to be best in comparison with uncoated and pyrocoated tubes. A Russian paper (86/1790) reported methods for determining As and Sb with satisfactory perfor-188R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 mance characteristics which prevented interactions between As and graphite by coating the tubes with Nb205 or Ta205. A comparison of metal furnaces (molybdenum, tantalum and tungsten) with graphite and the corresponding metal carbide coated carbon surfaces has been made (871465). Copper and Fe were used as test elements and it was found that atomisation of Cu occurred at lower temperatures with the metal furnaces, regardless of the anion (chloride, nitrate, perchlorate or sulphate). With Fe, the lowest atomisation temperature was obtained with a tungsten furnace.Ther- modynamic calculations showed that no oxide would form (from O2 in the Ar-sheath gas) on the tungsten surface whereas oxide formation would be expected on tantalum surfaces. Studies of the performance of tungsten atomisers and developments in the WETA system of Sychra continue to be reported (87/C140, 87/C1156). A variety of atomisation techniques with this device have been proposed including rapid heating, tungsten platform, the autoplatform effect (obtained by differential heating of a specially designed furnace) and the use of a resistively heated tungsten loop as a sample carrier. The use of a tungsten furnace for the determination of several elements in high-purity gallium has been described (87/1206).Detection limits for impurity elements were in the range 1-10 p.p.b. A comparison of pyrolytic graphite, zirconium-coated graphite and tungsten-coated graphite tubes has been repor- ted in the Chinese literature (8611744). The metal-coated tubes were found to be superior in the determination of A1 as they prevented the formation of both carbide, cyanide and nitride. 4.3. Sample Introduction There has been continued and growing interest in the determination of elements in solid samples without a dissolu- tion stage. This avoids the risks of contamination or loss associated with dissolution, but is not without problems as dif- ficulties with representative sub-sampling, enhanced vapour- phase interferences and other matrix effects are more severe.These problems and others were discussed in a comprehen- sive review by Langmyhr and Wibetoe (86/1725) containing 458 references. A recent edition of Fresenius 2. Anal. Chem. [ 1985, 322(7)] contains several papers concerned with solid sampling. The use of Zeeman-effect background correction (ZBC) was described (86/1784) for the determination of 0.2-10 mg kg-1 of Hg in fish, meat and grain. The same element was determined in compost, earthworms and mush- rooms (86/1794) by a similar procedure. Protein-rich samples were finely pulverised and covered with a layer of powdered carbon. Down to 0.1 mg kg-1 could be determined using a maximum sample mass of 2 mg and an atomisation tempera- ture of 1700 "C. In a short review (86/1812), the determination of a variety of analyte elements and sample types were discussed.As might be expected, sampling errors were found to be smaller for smaller particles and an even distribution of the element. For dusts, ores, metals, blood, body organs and plants, coefficients of variation of 5-10% at the 1 mg kg-1 level and 1&30% at the pg kg-1 level were obtained. Sample masses varied from 0.03 to 10 mg. A comparison of conventional sample preparation and direct determination was made for the determination of Cd in placenta (86/1758). Although comparable accuracy was obtained, the direct method exhibited poorer precision but was the preferred method due to its greater speed and relative freedom from contamination. The direct analysis of fresh sea food for Cd, H g and Pb has been found suitable for product quality control (86/1764)..A throughput of 120-150 samples per day was possible and ZBC was used. It was observed that in the analysis of canned sea food, migration into the liquid phase or adsorption on the can wall could be ignored. Satisfactory results were also reported (86/1765) for the direct determina- tion of Cd, Pb and Zn in fresh and freeze-dried pig liver. This was attributed to the near-uniform distribution of the ele- ments in the sample material. The RSD values using ZBC were: Cd, 7-10°/0; Pb, 5-16%; and Zn, 3-5%. The use of L'vov platforms has been briefly reviewed (86/1862) and a possible method for reducing interference effects by means of a modified L'vov platform reported. The use of a covered platform to reduce radiative heating of the sample was shown to reduce matrix effects for the determination of Pb in sodium sulphate.Platforms were used in a study of sample inho- mogeneity problems (86/1924). The use of relative homogeneity factors were discussed and illustrated for the analysis of CRM orchard leaves. The homogeneity of several RMs was found to be good enough to obtain precisions of about 1% for a sample mass of 100 mg. For situations in which a lower mass is taken (for example the determination of Hg in city waste incineration ash) a knowledge of the homogeneity factor is useful in devising a suitable method. The graphite cup in furnace atorniser has been used for both liquid and solid samples. For liquids (87/427) it was found that the cup behaved as a superior type of platform giving increased sensitivity (for Cd and Cu), longer lifetime and reduced interference.An organic solvent (IBMK) was found to give increased sensitivity for Cu and Fe. For the determina- tion of Mn in various biological reference materials (including NBS oyster tissue), a detection limit of 0.1 ng was reported with a working range of up to 17.5 mg kg-1 (86/1904). After drying (100 "C for 1 min) and ashing (500 "C for 2 min) atomisation at 2500 "C for 10 s was used. A matrix modifier (palladium) has been used (87/C868) in the determination of Se in biological materials. Possible loss mechanisms such as the volatility of organoselenium compounds and the incom- plete dissociation of hydrogen selenide or selenium monoxide were discussed.A comparison of graphite, pyrocoated graph- ite and glassy carbon cups has been presented (87/C1113). Two reports of the application of the graphite boat in furnace atomiser described the analysis of real samples. In the first of these (86/1717), A1 was determined in blood plasma by a method which required neither dilution nor matrix modifica- tion. The boat and tube were coated with vitrified carbon. The level of A1 in a healthy person was found to be in the range 22-56 pg 1-1 whereas haemodialysis patients had values ranging from 232 to 630 pg 1-1. In the second study (86/1803), various metals (Cu, Cr, Ni and Pb) were determined in extruded polyethylene with no chemical pre-treatment. Finally, Cd, Cu and Hg were determined (ZBC was used) in the suspended matter in lake water (86/1925).The introduction of solid material as either a suspension or a slurry would seem to be one approach to overcoming some of the difficulties associated with the direct analysis of solids. Jackson's group at the University of Saskatchewan has been active in this area. Their work aims to provide a better understanding of how the sample matrix influences the release of the analyte elements into the gas phase. In studies of the determination of Pb in soils (86/C1977) a model system of Pb - alumina has been used (86/C1976, 87/C840, 87/630). To model absorbed Pb, alumina was slurried in a lead solution before introduction into the furnace, whereas Pb trapped within particles was modelled by the addition of Pb in aluminium nitrate solution.The best furnace configuration for determining Pb (identical absorbance - time profiles for both types of Pb) was obtained by using a graphite platform in a pyrocoated furnace. Wall atomisation was unsuitable for analytical use (but might possibly be applied for kinetic and thermodynamic studies) as the difference in absorbance profiles and appearance times was considerable. The study has been extended to other metals in soils (87/C161, 87/C865) and to the use of matrix modifiers to off-set the effects of high levels of organic matter in some soils. Preliminary results forJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 189R the efficacy of magnesium, lanthanum, palladium and phosp- hate have been presented (87/C866). Other workers also used platform atomisation (87/1204) for the determination of Cd and Pb in plant materials, sediments and lyophilised animal tissue.A dispersion of powdered sample, glycerine, methanol, nitric acid and matrix modifier was found to be stable for up to 1 h permitting introduction via the auto- sampler. For the determination of Cd in dried foods, ashing in the presence of O2 was used to avoid a build up of carbonaceous residue in the tube (87/1184). Calibration by the standard additions method gave results in good agreement with those obtained with wet- and dry-ashing procedures. For the determination of Cu in dried milk powder (at the 6 mg kg-1 level) by either AAS or AES (86/1721), probe atomisation was used with a dispersion of the sample material. However, for the determination of Pb in spinach (86/1648), a stable slurry was prepared in Viscalex HV30 (a thickening agent consisting of acrylic acid polymers).Wall atomisation was used after ashing in the presence of O2 in the furnace. Levels down to 0.05 mg kg-1 could be determined. Extensions of the method to other similar analytical problems, including Cu in cabbage and pine needles, Pb in liver, tomato leaves, oyster tissue and spinach, Cd in sprouts and Cd, Cu, Mn, Pb and Zn in a synthetic protein have been reported (87/C186). However, simply stirring with dilute HN03 followed by injection of a 20-1-1.1 sample of the resultant slurry gave satisfactory results for the determination of Cd and Pb in similar matrices (86K1974). The success of the procedure was ascribed to the extraction of most of the analyte element into the liquid phase of the slurry.Coal has been analysed for As, Cd, Sb and Se by slurry atomisation with Smith-Hieftje background correction (87/C195). Partial wet oxidation fol- lowed by slurry atomisation has been successfully applied (87/297) to the determination of Cd and Pb in the concentra- tion range 1-50 mg kg-1 in biological materials. However, only partial success was achieved with the simpler procedure of suspending the fully ground material in water (87/C218). The combination of an aerosol deposition carbon furnace atomiser and a simultaneous multi-element, continuum- source, atomic absorption spectrometer (871689) was used for the determination of nine elements in water and fruit juices. The deposition temperature was 120 -fr 20 “C and the atomisation temperature was chosen with due regard to the least volatile element of interest.The same aerosol deposition system has also been used for slurry deposition (86/1851). Food samples were slurried in water and analysed for Cd, Cr, Cu, Mn and Ni. The method was preferred to a wet ashing (HN03 + HC104, 2 + 1) procedure. A nebulisation device for aerosol generation for flames and furnaces has been construc- ted (86/1775). The device had been used to introduce calibration standards in a procedure in which an impaction technique was used to collect the sample, but has now been coupled with a desolvation unit (87138). This was used for the determination of Cu, Mn and Se. Some difficulties were encountered in producing a dry aerosol.It was thought that a wet aerosol spread out and penetrated the tube giving a different response to that obtained with the deposition of a dry aerosol on the surface. A porous graphite probe has been used to collect air particulates (86/C1978). Analysis was performed by inserting the probe into a pre-heated graphite furnace. Recoveries of 91-107% were obtained for Al, As, Cd, Cu, Fe, Mn, Ni and Pb in CRM urban particulate matter. The potential for application in real-time pollution monitoring was suggested. The direct collection of respirable size metal containing aerosols on either the tube wall or platform has been suggested (87/C854) as an alternative to collection on filters followed by a conventional transfer and work-up procedure. A similar idea (86/2017) coupled “impaction” collection with electrostatic precipitation.A negatively charged tungsten needle was placed axially in a graphite cuvette which was electrically grounded. The capture efficiency was better than 98%. It was found that gaseous species such as Hg or AsH3 were less efficiently captured than solid or liquid particles. A dry aerosol has been generated from solid samples (metals and oxides) by the use of laser ablation (87/C1002) and transported to a graphite furnace. Trace levels of Ag, Cd, Fe, Mn, Ni, Pb and Zn were determined. No further details were available, but further reports are awaited with interest as laser ablation shows considerable promise as a solid-sampling technique for the ICP (see section 2.1.2). Several workers have reported the introduction of the analyte element as a vapour into an electrothermal atomiser.Sturgeon et al. have continued their work on hydride trapping, and have reported the determination of Se (86/1922) and As and Se (87/433). The strategy was to convert the analyte element into the volatile hydride in the conventional manner and to deposit the element in the graphite furnace held at a temperature of 600 “C. The normal analytical cycle of furnace operation was then completed. For the determination of Se in marine sediments, tissues and sea water a detection limit of 1.4 pg g-1 was obtained. For As in the same matrices, an absolute detection limit of 30 pg was obtained. The corresponding value for Se was 70 pg. Extension of the technique for other elements, Pb and Sn (87/C818) and Hg, Pb, Sb and Sn (871C1157) has been reported.A comparison of a quartz tube and a graphite tube atomiser for the direct decomposition of BiH3 has been reported (87/C987). The same group have described a graphite paper atomiser for decomposition of hydrides. A sheet of graphite paper (EKL, Berlin, GDR), 0.1 mm thick, was rolled up to produce a cylinder 92 mm long and 9 mm in diameter. Contact was made via brass electrodes with graphite liners and collapse of the tube was prevented by the insertion of graphite rings. The atomiser was used for the determination of As, Sb, Se and Te in a variety of hydride forming element matrices (86/1639). The paper atomiser produced a detection limit of between 0.1 and 0.5 ng, up to 1000 times better than the silica tube atomiser (see JAAS, 1986, 1, 152R).For an atomisation temperature of 2000 “C, the tube lifetime was 70-100 firings. The major source of interference was found to be the formation of vapour phase diatomic molecules (86/1640). The use of matrix modifiers with this system (Cu2+ to reduce interferences from Se and Te and EDTA to reduce the effect of Bi) has also been described (87/434). The decomposition of BiH3 on a graphite tube has been studied to elucidate kinetic parameters of the reaction (87/369) that was used as a pre-concentration step. Also reported in the Russian literature was the use of chloride generation for the determination of Si in high-purity indium. A detection limit of 100 ng 8-1 was obtained (86/1886). A method for the determination of tetraalkyllead and ionic alkyllead species by the separation of the propylation deriva- tives by GLC with AAS detection has been described (86/1629).A heated silica tube atomiser was used. 4.4. Fundamental Processes The elucidation of atomisation mechanisms still provides a considerable challenge, and a large amount of experimental work has been directed towards achieving a better under- standing of such processes. It is obvious that atomisation is a complex sequence of physical and chemical processes, pos- sibly occurring in parallel as well as sequentially, which depends on the nature of: ( a ) the surfaces involved, ( b ) the sample, ( c ) the matrix, ( d ) vapour phase composition, (e) the heating rate and (f) the temperature distribution, to name some of the factors which have been investigated.The recent literature has been reviewed (87/921) with particular reference to the information obtainable from absorbance - time (temperature) profiles such as Arrhenius activation energy parameters and the role of oxygen partial190R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 pressure. The latter has been the subject of several studies (86/C1543, 86/1828, 86/C1965) and has been reviewed in the Chinese literature (87/585). The presence of 0.5% 0 2 in theAr purge gas was found to decrease the characteristic mass for Mn by about 20% (86/C1543). The original sensitivity was restored after removal of O2 from the gas flow. Factors affecting the instantaneous partial pressure of oxygen inside the furnace have been studied and it was suggested (86/1828) that the most important were the initial amount of 0 2 and the heating rate.The origins of O2 within the furnace have also been discussed (87/1464) and included surface oxide, sample and Ar impurities. The role of carbon monoxide has also been investigated (87/520). The amount of CO was affected by the addition of an NaN03 matrix. As CO levels will be important in controlling atom formation in reactions which proceed via an oxide decomposition, variation of the CO partial pressure was used as a diagnostic tool. In agreement with theoretical calcula- tions, the appearance of Bi, Cr and Pb atoms were affected by CO levels, whereas Ag and Cu atomisation was not. The effect of thermal pre-treatment and graphite surface on absorbance signals have been reported (87/C879).The role of O2 in the atomisation of Pb has been discussed in detail (87/429). In addition to vapour reactions, O2 modified the graphite surface resulting in the binding of Pb to surface functional groups. Oxygen is also chemisorbed. Studies of temperature profiles and temperature measurements have been comprehensively reviewed (87/461), by Rademeyer and Human. The role of the shape of the furnace in governing temperature distributions has been evaluated (87/122), with particular comment on the difficulty of measuring gas phase temperatures. For volatile elements, it has been pointed out (86/1613) that their residence time is controlled by expansion when wall atomisation at high heating rates and high atomisation temperatures is used.Thus the sensitivities for such elements are improved by removing temperature grad- ients and by using “isothermal” atomisation devices (such as platforms or probes). Temperature gradients in a tungsten furnace have also been studied (87/960). Matching the analyte atomisation to the ideal entry time to the furnace temperature profile (i.e., when the gas expansion has ceased and the extent of the isothermal zone is maximum) has been discussed with specific reference to the use of a platform (87/C842). The literature concerning the effect of gas-phase composition has been briefly reviewed (87/361) in Spanish, as has the effect of 0 2 and tube size on the dimerisation of Se (87/78). It was concluded that dimerisation is favoured by atomisation at the tube wall.Several papers have described methods by which informa- tion concerning atomisation mechanisms may be obtained. Absorbance and temperature values were simultaneously monitored to provide data from which to calculate possible mechanisms (86/1705). Selenium determination has been studied by using 75Se to monitor losses during thermal pre-treatment (87/111, 87/C1102). X-ray diffraction has been used to identify intermediate species in the formation of Mo atoms from ammonium molybdate solution (87/431). A more detailed study used scanning electron micrography, XRF and Auger electron spectroscopy (87/615). Three Mo oxides (MoO2, Moo3 and Mo4OI1) were observed to form at relatively low temperatures (below 1500 K). When pyrolytic graphite or electrographite was used, Mo, MoC and Mo2C were all found.It was concluded that loss of Mo could be avoided during the ashing stage (up to 2100 K) if an electrographite surface was used. A major limitation to this work, pointed out by the authors, is that amounts of “sample” about 105-times larger than would be taken for analytical purposes were used. Thus the observations may not be translatable into analytical situations in which, possibly, matrix components would be in excess. Molybdenum atomisa- tion was studied along with certain other elements by XRD, electron microscopy and molecular absorption (87/430). It was concluded that the atomisation pathway involved formation of carbides, formation of volatile sub-oxides, thermal decompo- sition of oxides and vaporisation of the metal.The atomisation of Ge was also discussed in detail and preliminary results for Ag, Au, Cr, Cu and V were given. Results for the effect of interfering elements have also been presented (87/C836). Styris’ group have continued to use mass spectrometry to study the formation of vapour phase species (86/C1966, 87/463, 87/C890, 87/C837). Two modes of operation were used, one using furnaces heated in vacuo and the other using a furnace at atmospheric pressure. In a study of the atomisation of A1 when no modifier was present, aluminium dicarbide and the lower oxide were observed concurrently with the appear- ance of Al. In the presence of magnesium as a modifier, the same species were observed at higher temperatures. It was suggested that condensed phase dissociation of A1203 is responsible for the atomisation and that the magnesium oxide was reduced by adsorbed Al.The atomisation of Se and the role of nickel as a matrix modifier has been studied (87/463). The results indicated that the primary loss mechanism at low temperatures was from the thermal dissociation of selenium dicarbide and that secondary mechanisms are the vaporisation of the dimer and of oxides. Nickel nitrate was observed to inhibit the formation of all of these species. A time-gated Schlieren system has been devised for observ- ing the transport of the analyte during the course of atomisation (87K839). The system consisted of a two-lens Schlieren configuration and a pulsed dye laser tunable near the resonance wavelength of the analyte, together with a modified 35-mm camera to record the image.For a single firing of the furnace, the system produces a series of photographs. The refractive index gradients so studied should provide information about the rate of mass transport and thus identify situations where this is controlled by analyte surface interaction. The same research group has also studied the form of the sample on the atomisation surface (87/C1159). Silver and Au were observed to be present as “micro-droplets” weakly adsorbed on the surface, whereas Cu was found to be dispersed and to show moderately strong interactions with the graphite. Mass spectrometry has also been used in a study of the atomisation of Pb under vacuum (10-1 Torr) (87/C843). In the “absence” of the gas phase, it was considered that surface reactions could be investigated. Results showed the release of CO and C02 along with atomic Pb, suggesting strong interaction with the graphite and the formation of a surface bound species. In order to overcome certain atom-loss reactions, the vapour phase has been modified by the deliberate addition of gases.It was shown that the addition of a small volume (50-300 pl) of a C12 - N2 mixture (1 + 5 ) during the atomisation step aided the volatilisation of Cr and V carbides (87/1470). The use of a tantalum-foil lining in conjunction with the addition of H2 to the purge gas (5% in Ar) improved the liner lifetime, thouph sensitivity (for Eu) was not significantly changed (87/12L8). The use of H2 (10% in Ar) was shown to be beneficial in the determination of Bi in river sediment (87/1473).No pre-concentration was used and the concentra- tion range was 1-5 mg kg-1. There have been several reports of the use of models for atomisation and comparison of the results predicted with those obtained in practice. Of course, agreement does not neces- sarily mean that the model is correct. In a study of Au, Bi and Pb atomisation at atmospheric pressure and in vacuo (10-9 Torr) activation energies calcu- lated from the leading edge of the absorbance - temperature plot were in agreement with a model that assumed the analyte to be present on the graphite surface in the form of microparticles as opposed to a monolayer (871930). Nakamu- ra’s group have modelled both the temperature profile of the atomiser (871620) and the formation of atoms (87/592,JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 191R 8711290). In the first of these studies, a tungsten-ribbon atomiser was used and a power balance model employed which calculated the power supplied to the atomiser and the power lost by convection in the sheath gas. The calculated temperatures agreed with those measured with a pyrometer (k 15 K at 1000-2000 K). Atom formation above the atomiser was modelled by a simple Arrhenius-type expression and agreed well with experimental results for Ag, Cu and Fe. A modelling approach to the investigation of the source of variations in absorbance characteristics has been described (87/C823). The accompanying experimental work aimed to elucidate the effect of changes in temperature function, activation energy, sample position and matrix on the absorb- ance charactersitics and to compare the results with the results of modelled perturbations.A variety of peak parameters were used as indicators of the absorbance characteristics (86K1546). These inlcuded peak height, area and several time-based parameters (appearance, peak maximum, decay to 1/2, lle, lle2 of maximum and end). A low-frequency noise component was identified and it was suggested that this might be due to the drying process. Monte Carlo simulation has been used to model atom generation and diffusion within the furnace (86/C1545, 87/C821). When compared with experimental results for Au and Cu, contrasting behaviours for the two elements were found. The results for Cu could be interpreted as the generation of atoms preceded by the dispersion of Cu across the surface in a sub-monolayer distribution.Thus the main interaction energies governing release of Cu are those between Cu and carbon. For Au however it appeared that the atomisation was from “droplets” or islands of the metal, i.e., the main interaction energy was between Au and Au rather than Au and carbon. Evidence was also obtained that the presence of furnace atmosphere permitted the dispersion of Cu across the surface. The effect of changing the heating rate and axial temperature distribu- tion have also been modelled. Silver was found to behave in a manner similar to Au (86/C1588), and the applicability of the Langmuir diffusion model to the vaporisation from spherical droplets has also been reported (87/C841).The temperature rise of a capacitive-discharge heated graphite furnace and the gas phase has been modelled (86/1678). Heat loss mechanisms by conduction via the electrode contacts and radiation were considered for the furnace and conduction was the only mechanism of gas heating that was considered. The results were compared with experimental results obtained from a pyrometer and a two-line AA method (86/1679). The effect of O2 on the appearance temperatures of ten elements was modelled by thermodynamic equilibrium calculations for the gas phase (871594). Five elements, Ag, Cu, Mg, Mn and Ni, showed no change with increasing O2 content (0.005-1 .OO/O VIV) and this was interpreted as being due to the absence of thermodynamic equilibrium in the gas phase.The other elements, Al, Ba, Pb, Si and Sn, all showed a significant change in appearance temperature with O2 content and good agreement with predicted behaviour was obtained for Pb, Si and Sn. The atomisation of Sn has been modelled by thermodynamic calculations (871C1078) which took account of both temperature and gas composition effects. The effect of the repeated collisions of analyte atoms with the tube wall before leaving the absorption volume has been studied by Welz (87/C838) using a model developed by Musil and RubeSka (Musil, J., and RubeSka, I . , Analyst, 1982,107, 588). The differences observed between absorbance signals in glassy carbon, pyrolytic and electrographite tubes were ascribed to different interactions between metal atoms and the various graphite surfaces.Several reports have appeared from Russian groups con- cerning the results of modelling studies (86/1731, 871C1112, 87/C1155). The first of these attempted to identify various limiting stages in the atomisation process for 15 elements by comparison of experimental activation energies with the heats of evaporation or sublimation of the elements and the dissociation energies of the monoxides. The second report used a model which accounts for diffusion under concentra- tion and thermal gradients, convective gas expansion and the dimensions of the atomiser. The model also accounts for the temperature dependence of the diffusion coefficients. The third study concentrated on Cu and used calculations of all reasonable reaction products between Cu, C, H, 0, Ar and C1 as a basis of predicting the optimum conditions for the determination of Cu.Calculations of the characteristic mass of 40 elements were compared with experimental values by L’vov et al. (87/958). Stabilised temperature platform furnace (STPF) conditions were employed for the majority of elements and the model considered vapour diffusion from the tube centre towards the ends under temporal and spatial isothermal conditions. Reasonable agreement was obtained for 30 of the elements atomised under STPF conditions but discrepancies were observed for elements atomised off the tube wall. These included Ca, Mo, V and Yb (factor of two) and Ba, Er, Eu, Si, Sr and Ti (factors of three to ten). The discrepancies were accounted for by the formation of stable gaseous carbides and monocyanides.Overall, it was concluded that the results supported the possibility of the development of absolute (i.e., standardless) methods of analysis based on the STPF tech- nique. 4.5. Interference Studies Much of the published work on ETA-AAS is concerned with obtaining accurate analyses and thus with the reduction of, or compensation for, interference effects. Many of the reports reviewed in sections 4.1, 4.2 and 4.3 (atomiser design, atomisation surface and sample introduction) describe work motivated by the desire to eliminate a variety of interferences. This section is mainly concerned with background correction and matrix modification techniques. Several studies report on the use of combined techniques to remove interferences.As a result of high-temperature equilibrium calculations Frech et al. (86/1669) concluded that many interference effects originate in reactions which occur at relatively low temper- atures. The effect of CuC12 and NaCl on the atomisation of several elements from a L’vov platform was studied to devise optimum conditions for their determination in the presence of chlorine. For the majority of elements studied (Al, As, Au, Be, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb and Sn), suitable modifiers and temperature programmes were established which removed the C1 interference. Such conditions were not obtained for Ag, or for Bi, Se and Te (loss during pre- treatment). The same authors have reviewed approaches for reducing interference effects, particularly those arising from sulphate and chloride matrices (86/1815).Slavin has reviewed the stabilised temperature platform furnace approach in combination with Zeeman background correction (ZBC) and provided some information on matrix modifiers and characteristic masses (86/1471). Aspects of the STPF - ZBC approach have been reported on several occa- sions (87/C731, 87/C819, 87/C1162) by the same group. Mechanisms of interference effects as elucidated by the techniques of XRD, SEM and Auger electron spectrometry have been discussed (87/C1161). This report also compared results with those obtained with dual-cavity platforms and probes. The use of the standard additions method for compensating for interference effects has been critically evaluated by Welz (86/C2035, 87/1254) who pointed out that the method only compensates for those effects which cause a change in slope of the calibration and that in order to give accurate results, the added analyte must behave in the same way as the sample analyte.It was concluded that a more reliable approach to obtaining accurate analyses was to eliminate the causes of the interference effects.192R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 The delayed atomisation cuvette is one such approach (86/1920). In combination with an aerosol sampling device, a variety of trace elements in an NBS natural water reference material were accurately determined. A useful tool for investigating the mechanism of interference effects is the dual-cavity platform. This allows spatial separation of analyte and matrix and thus distinction between condensed- and vapour-phase interferences.This device has been used to study the interference of Cu(N03)2 on Mn (86/C1963), and of CuC12 (86/1669) on Ag (mainly vapour phase) and Bi (mainly condensed phase). Halide interferences have also been studied by following the molecular absorbancies of the monohalides of alkali and alkaline earth elements, A1 and In (86/1612). It was found that temporal overlap of the atomisa- tion profiles of these last two elements with the corresponding monofluoride absorption profiles was not observed, indicating that the formation of such molecules is not a pure vapour- phase reaction. The use of Sr(NO& as a matrix modifier for In was demonstrated. The use of background-correction techniques continues to be evaluated and several comparisons of different techniques have been made.The importance of appropriate signal processing techniques for use in conjunction with ZBC have been discussed (86/1615). The need for rapid measurement and integration facilities were stressed. A Japanese report has compared all three commercially available techniques (87/ 918). The suitability of the Smith - Hieftje method (temporary self-reversal of the HCL output by application of a high- current pulse) for the determination of Cr in solid Ga-As semiconductor material, has been demonstrated (86/1650). Calibration against aqueous standards was used. Japanese workers have also evaluated the Smith - Hieftje system for its effect on the sensitivity for 26 elements (87/1310).This technique and ZBC successfully corrected for the overlap of Sb and Mn lines with the Ni analytical line at 231.0 nm. A comparison between the deuterium-arc lamp (continuum) method of background correction and ZBC has been reported (86/C1594, 87/46). In the latter study, the deuterium-arc method was found to be unsatisfactory for the determination of As, Cd and Se in samples of marine biological tissue. Calibration against acidified standard solutions was possible for Cd and Se under STPF conditions, but not for As. The Smith - Hieftje system and ZBC have been compared for the determination of Cd (86/1914), and of Cd, Cu and Pb in a sodium chloride matrix (86/C1565). Both systems were found, according to the latter report, to reduce the Cd sensitivity by about 17%.Problems with the anomalous Zeeman splitting of Cr were also discussed. A Smith - Hieftje type system has also been described in the Chinese literature (87/471). The possibility of over-correction errors arising with the use of the deuterium-arc method when a structured background is present has been reviewed (86/1909) and a comprehensive listing of potential problem situations provided for 40 ele- ments. A detailed study of the effects of Co, Mn or Ni on 30 elements (53 lines) when ZBC was used has been made (86/1787). It was found that when the magnetic field was on, a u-component of a Co line overlapped the emission profile of B (249.7), Hg (253.7) and Au (267.6 nm). Over-correction errors for Hg and Au were obtained.The effect on Hg could be removed by optimising the furnace programme, but for the determination of Au, the alternative line at 242.8 nm was recommended. In a follow-up study (Part 3 in the series), a further 18 cases of such over-compensation were found, but only three of these occurred at the recommended wavelength for the analyte, namely at 459.4 nm for Eu in the presence of V or Cs, at the 247.6-nm Pd line in the presence of Pb and at the 265.9-nm Pt line in the presence of Eu (87/1474). Over- compensation with the ZBC system has also been observed when structured molecular bands fall within the emission profile of the analyte element lamp (87/634). An example of the interference of the PO bands on Cd at 326.1 nm was given. The implication for the use of the normal matrix modifier for Cd (ammonium phosphate and magnesium nitrate) was discussed.The role of stray light in the performance of Smith - Hieftje and Zeeman-correction systems has been evaluated (87/132). It was concluded that errors could arise if the stray light occurred close to the absorption line of the analyte, but this was unlikely to cause a problem unless a background absorbance of two is encountered with a level of unabsorbed stray light greater than 0.01%. Problems with the temporal mis-match between measure- ment of the total signal and the background signal, which causes errors with rapidly changing signals, have been pointed out (86/C1564, 87/C730) and a method for overcoming this error has been proposed by Harnly and Holcombe (87/C145, 87/C886, 874196).This method is based on interpolation between the background absorption data points which bracket the analyte absorption by a linear or quadratic function. Depending on the number of points taken (2, 3 or 4) for the quadratic function, the errors are proportional to the appro- priate derivative (2nd, 3rd or 4th). Thus background correc- tion errors can be predicted accurately by superimposing a plot of the correct derivative of the background signal on the analytical signal. Errors arising from misalignment of the deuterium and hollow-cathode lamp beams can be minimised by using a simple alignment jig (86/1704). An evaluation of matrix modifiers for the determination of Ag, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Se in a variety of health and environmental materials (87/C853) has been undertaken. The effect of various instrumental operating parameters and signal measurement strategies were evalu- ated.There has been considerable interest in the determina- tion of Se, particularly in biological materials. It was found (87/111, 87/C817) that Ni was effective in stabilising SeIV and SeVI in the presence of NaCl and Na2S04, but with the addition of an organic matrix (glucose) the stabilising effect was lost. This study used 75Se to monitor loss of the element. Mass spectrometry has also been used (86/C1548) to study the action of Ni as a matrix modifier. This report also considered that atomic Fe did not produce a spectral interference. Oxygen plays a dual role in that it can cause a spectral interference by the formation of iron oxide as well as absorbing (via the Schumann - Runge band system) at the Se 196.09-nm resonance line (87/3). It was observed that O2 was produced during the decomposition of oxyanion salts of elements added as matrix modifiers.Among other matrix modifiers used were palladium (86/1468, 86/C1516, 86/1715, 86/1882,87/383, 87/C746,87/C820,87/C880,87/1275); pallad- ium with nickel (86/C1542) and with magnesium (871C751, 87/1222); nickel salts both alone (86/C1587, 86/1672) and in combination with other elements (86/1790, 86/1938, 87/437); lanthanum (87/C204, 87/1224, 87/1457); iridium (86/1749); magnesium salts (86/1631, 86/1845);, phosphates (86/1628, 86/1984, 87/410); and thiourea (86/1726). The various purposes for which alternative gases may be used have been discussed (87/C142).These included the addition of 0 2 during the ashing step, of CH4 during the atomisation of refractory elements and of Freon during the cleaning stage to reduce memory effects and increase tube lifetime. Two groups have found the addition of H2 to be beneficial in the determination of Pb in bovine liver and soil (87/329) and brown algae (87/396). In the first of these studies, an Ar - H2 mixture was used as purge gas with low temperature atomisation (950 "C), whereas in the second, H2 was used instead of Ar during the drying and charring steps. A procedure for the determination of Sn in rocks which uses several approaches to eliminating interferences has been described (86/1617). The Sn was extracted into an organic solvent which does not contain chlorine [heptane and amyl acetate (2 + 1) was used] as the chloro-N-benzoyl-l phenyl- hydroxylamine or 8-hydroxyquinolol complex, ascorbic acidJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 193R as a modifier was added and atomisation was from a platform into a tungsten carbide coated tube. A deuterium-arc back- ground corrector was used. A procedure for the determination of As using hydride generation to separate As from the sample matrix following trapping in a solution containing ammonium cerium(1V) nitrate and potassium iodide has been described (871C210). The cerium was found to be an effective matrix modifier. 4.6. Developments in Technique Faster analysis times have been achieved by the omission of the ashing stage when this plays no role in reducing interferences or background absorption (86/C2037).Methods were devel- oped for the determination of Cd and Pb in blood, Cu in urine and A1 in dialysate fluids with cycle times of about 60 s. For the determination of Pb in plant digests, platform atomisation was used with ammonium dihydrogen phosphate as modifier. The cycle time was 72 s. Detection limits for 14 elements in the presence of 50 pg of copper have been determined, with ZBC, by the method of ensemble summation (87/1304). To avoid distortion of absorbance and temperature signals by the measurement system, a commercially available spectrometer has been modified to allow the direct measurement of the PMT output by a computer and the use of a pyrometer with small capacitance (86/1777).The isotopic composition of lead samples containing *04Pb, 206Pb, 207Pb and 2*gPb has been measured by the total absorbance for the 283.3-nm line with a continuum-source spectrometer (87/385). The experimental values agreed well with values calculated from thermodynamic data on the saturated vapour pressure of Pb. The sample size was about 1 mg. A comparison of background correction using the Zeeman effect with the magnet in the longitudinal position rather than the “normal” transverse position has been made (87/C1119), but no details of performance were given. Further details of the wavelength modulated continuum- source spectrometer for AA and emission, based on a high intensity Xe-arc lamp source and an echelle spectrometer, have been reported (87/C147, 87/C732, 871C1144).The performance of the background correction system has been compared with that of deuterium-arc and Zeeman systems. The use of the instrument for the determination of trace elements in biological samples has been described (871C898). A variety of spectroscopic modes were utilised. The prospects for 100% atomisation of all the analyte elements, despite the matrix composition, has been discussed (87/C895) and the possibility of constructing an absolute spectrometer assessed. Continuum-source atomic absorption also provides a capabil- ity for simultaneous multi-element determinations. The scope of the instrument has again been stressed (86/C1975) in terms of the wide dynamic range, excellent background correction and low detection limits and its use in a rapid-survey mode as well as high-accuracy mode described (87/347). In the first mode, the aim is to identify whether an element is a trace contaminant or a major component.Thus accuracy of It 100% is perfectly satisfactory for this purpose. The high-accuracy mode was used for determining trace elements in bovine serum, with RSD values of 18-50%, when some concentra- tions were close to or at the detection limit. Two methods for extending the normal working range upwards have been described, The first of these was based on a Zeeman system in which measurements were made at three different field strengths, zero, maximum and an intermediate value (87/621). The useful dynamic range was extended by a factor of ten. A similar factor was obtained by the second method (87/367), which is based on measurement of the peak width rather than peak height.This approach is analogous to that employed for extended range calibrations in flame AAS using a peak-width FI method (see Tyson, J. F., Analyst, 1984, 109, 319). Several groups of workers have evaluated the analytical possibilities of coherent forward scattering (CFS) spectrometry (also known as magneto-optical rotation). The use of a laser light source has been employed by Winefordner’s group (86/C1558, 87/1223). The results do not appear particularly encouraging as far as detection limits are concerned. However, the opposite conclusion is reached by Hieftje’s group (86/C1544) and the possibilities of background correc- tion with the system are discussed. Real analytical applications have been described by Hirokawa et al.(87/1209, 87/1461) using a system with a continuum light source. In the first of these, Ag was determined in lead and Cu, Pb, Sn and Zn in steel, copper and tin and Cd was determined in zinc, lead and tin. A normal acid dissolution procedure was used, but for the tin samples the matrix was removed as SnBr4. In the second study, the possibility of enhancing the sensitivity for Yb (as a typical rare earth element) was investigated by increasing the radiation intensity. Dawson’s group (87/C150) have described a system which used a pulsed HCL source and a segmented rod atomiser. Only preliminary results for the determination of Cu were reported. Background correction was calculated from the intensity of radiation transmitted when the axes of the polarisers were parallel (in normal operation, the polarisers are crossed).Debus et al. (87/432) commented on the multi-element possibilities of CFS spec- trometry with a continuum source and drew attention to the satisfactory detection limits for many elements. Background correction by modulation of the degree of polarisation was used in the determination of Cd in human blood. There is a continuing interest in the analytical capabilities of atomic emission spectrometry with an electrothermal atomiser. A constant-temperature furnace has been combined with an echelle monochromator fitted with a quartz refractor plate for wavelength modulated background correction (87/371). This instrument was used to determine trace elements in NBS reference materials and detection limits for 16 elements were measured.Developments in this type of instrumentation have continued with the construction and evaluation of a low- resolution monochromator based instrument (86/1892). The same method of background correction was used. Detection limits for probe atomisation and totally pyrolytic graphite tubes for Cd, Cr, Cu, Mn and Pb were a factor of 4-13 poorer than those obtained with a similar atomisation system and echelle spectrometer. The low-resolution instrument was successfully used for the determination of Cr in urine (86/1796). A second version of the instrument using a different manufacturet’s atomiser and monochromator has also been described (87/C728). Atomic emission spectrometry is just one of the modes of measurement possible with the so-called furnace atomic non-thermal excitation spectrometry (FANES) system, in which the furnace is used as the cathode in a hollow-cathode discharge lamp.Dittrich’s group have compared FANES, ETA and LAFS (86/1739) for the determination of Ga. The LAFS method had the best detection limit of 10 pg, FANES 20 pg and ETA-AAS 45 pg. Conference presentations from this group have described the determination of trace rare earths by FANES and FINES (ionic emission) (87/C1058), the determi- nation of 99Tc by FANES (87/C1059) using both carbon and tungsten atomisers, further details of this atomiser (87/C1060) and a comparison of molecular non-thermal excitation spec- trometry (MONES) with FANES, LAFS and laser-excited molecular fluorescence spectrometry (LAMOFS) (87/C1163, 87/C1322).The molecular spectrometries were applied to the determination of non-metals. Falk et al. (86/1916) have reported on developments in the FANES technique for trace metal analysis. Typical detection limits were quoted as being at the pg per 50 vl level. Details of their system have been194R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 given (87/623) and the operating parameters listed for the determination of Cu, Fe and Ni in grass, maize and standard orchard leaves by direct analysis of the solid material. Further developments have also been reported in a series of conference presentations (87/C726, 87/C892) including the simultaneous determination of Al, Co, Cr, Ciu, Fe and Ni in simple matrices (H20, HN03 and HCl) (87/C1061), a description of a FANES - echelle spectrometer instrument (87/C1063) and a general review of ETA sources (87/C1165) showing the application of FANES to fundamental studies of the evaporation and dissociation processes.This group have also compared ETA-AAS, LAFS and FANES (871C1321) and reported, in conjunction with the Strathclyde group, a method for the determination of Cd in blood (86/1642). This study illustrated the advantage of FANES over ETA-AAS in that, although the method of standard additions was necessary, a 100-fold greater tolerance of chloride matrix was obtained compared with ETA-AAS. The detection limit in deproteinised blood was 0.2 pg 1-1 and in distilled water, 0.04 pg 1-1. The fundamental characteristics of the technique have also been discussed (87/C148,87/425). Initial attempts to measure changes in the electron partial pressure from the HP line profile at 486.13 nm were only partly successful.Also of relevance to this section are AFS with a tungsten- coil atorniser (87/1485), Zeeman-corrected AFS (87/1198), isotope differentiation (63Cu and 65Cu) by a variety of atomic spectroscopic techniques (86/C1586), two new commercially available spectrometers (86/C1531, 861C1540) and a descrip- tion of various applications of lasers, including the vaporisa- tion of solid material for transport into an electrothermal atomiser (87/C144). Values of the collisional shifts in the resonance line wavelengths of Al, Ca, Cd, Cr, Cu, Ga, In, Mg and Sr in Ar, He and N2 atmospheres at 140 kPa pressure have been measured (87/357). In Ar and N2, all lines showed a similar red shift (apart from In in N2 which showed no shift).In He, all lines showed a blue shift apart from Sr which was red shifted. Temperatures of from 1500 to 2200 K were used. 5. CHEMICAL VAPOUR GENERATION In keeping with the historical flavour of last year's introduc- tion, a matter of fact needs to be emphasised. In almost every paper on hydride generation for analytical atomic spec- trometry, where authors have cited earlier workers in the field, Holak is credited with the first report (see Anal. Chem., 1969,41,1712). In fact the work of Erdey et al. utilised hydride generation with d.c. arc AES some 14 years earlier (see Erdey, L., Gegus, E., and Kocsis, E., Acta Chim.Hung., 1955,7,343). Of the 100 relevant reports received in the past review year most were concerned with applications and are not included here, but will appear under the particular ASU topic heading. Work cited here was related to studies on fundamental chemical or spectroscopic processes together with novel approaches to chemical vapour generation or the instrumentation employed. 5.1. Hydride Generation The chemistry of hydride generation has been studied by a number of groups. Fujita and Takada (86/2033) measured thermodynamic and kinetic stabilities of AsH3 and SbH3. They found that AsH3 and SbH3 were stable at temperatures up to 40 "C whereas BiH3 was both thermally and kinetically unstable at 25 "C. In practical terms this work may lead to improvement in the detection limit for Bi if workers take account of this data with respect to generator design.Brovka et al. (87/369) determined the rate constants for the thermal decomposition of BiH3 on a graphite surface at 273,285 and 297 K. Agterdenbos and Bay (87/421) found that within 10 ms of the injection of NaBH4, the reductant was spent and therefore the production of the hydrides was much faster. The evolution of the hydrides from solution required a longer time. These workers believed that the interference of heavy metal ions resulted from their catalytic effect on the decomposition of NaBH4 before it could react with the analyte. Rodriguez et al. (87K208) reported the enhancement of the rate and efficiency of PbH4 generation in the presence of Co, Mn and Ni.Continuing interest was shown in the mechanisms of hydride atomisation. Agterdenbos and co-workers (87/75, 87/78) published detailed studies on the generation and atomisation of H2Se. They discussed the effects of H2 and 0 2 levels and the role played by the cuvette wall. Reducing the cuvette diameter at low carrier gas flow-rates lowered the Se absorption which was attributed to the dimerisation of Se to Se2 catalysed by the quartz surface. The same group have reported (87/636) on atomisation reactions of AsH3 using thermodynamic and spectroscopic considerations; they proposed the following atomisation reaction 4AsH3 + 302 + 4As + 6Hz0 They also found evidence for dimerisation of As at the tube walls. Welz and Schubert-Jacobs (87/C202, 87/928, 87/C989) employed controlled evolution of various hydrides and various other gases into a heated quartz tube to investigate further the role of the H radical.They found that without H radicals, hydrides thermally decomposed giving rise to only partial atomisation and analyte adsorption on the tube walls. Wang et al. (87/949) examined AsH3 atomisation in a 19-cm cell (A1203). Dittrich and Mandry (86/1639, 86/1640, 87/319) have now published their studies on interferences in the generation and atomisation of hydrides (see also JAAS, 1986, 1, 152R). These workers spectroscopically identified the presence of AsSb as a vapour phase interferent on the determination of As in the presence of Sb (87/434). Studies appeared on the design of atomisation tubes. Yang and Guo (87/275) introduced hydrides into a closed-end silica tube with a longitudinal slot on the top which supported an Ar-H2 entrained air flame in the light path.The authors claimed that significant reductions in vapour-phase interfer- ences could be achieved with this configuration. Tsunoda et al. (87/374) examined various flame-in-tube atomisers and repor- ted a detection limit of 4.7 X 10-11 g for a tube of 50 cm length and 1 mm diameter. Chemical interferences on the generation of hydrides has received some attention over the past year. Welz and Schubert-Jacobs (86/1930) published the fourth part of the work on the mechanisms of interferences caused by the transition metals. In this paper they discussed the influence of acid and NaBH4 concentrations. Bye (87139) reported the use of various oxidants to counter the effect of NiII on H2Se generation and found that Fe"' was the most effective.He has also published a theoretical discussion which suggested that bivalent cations react with NaBH4 to form borides which in turn react with H2Se prior to evolution (87/292). We hope that this idea will be substantiated with some experimental evidence. Other papers on interference studies have also appeared (87/597, 87/1498) and a review has been presented by Guo and Li (87/8). Sturgeon et al. (86/1922,87/266,87/433,87/C818) have used the in situ adsorption - pre-concentration of gaseous hydrides within a graphite tube atomiser for the determination of As, Pb, Se and Sn in environmental and biological samples.JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 195R Pre-concentration of AsH3 in CeIV iodide solutions (87/C210) and iodine based solutions (87/441) with GFAAS determina- tion of the concentrate were reported to give picogram detection limits.The generation of SnH4 (87/12) and BiH3 (871C230) from non-aqueous media after liquid pre-concen- tration of the analyte was reported. A number of reports on hydride generation for atomic fluorescence spectroscopy were received this year (86/1793, 86/1928,86/2006). Rigin (860928) described the generation of the hydrides of As, Bi, Ge, Pb, Sb, Se, Sn and Te from a single sample in the presence of coinage and platinum group metals. The hydrides were trapped on Chromosorb 102 at 253 K and successively eluted into He at 1800 K for detection by non-dispersive AFS.Dedina (87/420) has now published his work on optimisation of hydride generation (see JAAS, 1986, 1, 121R). Pyen et al. (86/1839) used a fixed-size simplex to optimise a commercial hydride generator for the simultaneous determination of As, Se and Sb by ICP-AES. A mathematical model for continuous hydride generation ICP-AES was reported by Wang and Barnes (87/632). Anderson et al. (87/675) utilised continuous hydride generation for the selective reduction of different arsenic species. A number of reports have also appeared on flow injection or suction flow hydride generation (86/C1570, 86/1633, 86/1718, 8611780). 5.2. Mercury and Other Elements Nakamura and Namiki (8611770, 87/306) used MnOz and KMn04 coated glass beads to trap atmospheric Hg prior to elution and ETA-AAS.Sychra and co-workers (87/C999) designed and built a commercial instrument for trace Hg determinations on either solid or liquid samples. Two novel chemical generations were reported over the past year. Kuznetsov et al. (86/1886) determined Si in high-purity indium by evolution of SiC14. The reaction was carried out with CuClz at 470 "C for 7 min. The SiC14 was swept into a graphite furnace to give a 20-detection limit of 0.06 pg g-1 in the solid. Motojima et al. (87/377) used CeIV to produce Ru04 from Ru"* solutions, thus improving the FAAS sensitivity by a factor of 60 because of the increased volatility of the analyte in the spray chamber. There has been revived interest in the generation of methoxy boric ester for the determination of B by FAAS (86/1470) and ICP-AES (871291) (see also Siemer, D.D., Anal. Chem., 1982, 54, 1321). LOCATION OF REFERENCES The full references cited in this Update have been published as follows: 86/1461-86/1834, J . Anal. At. Spectrom., 1986, 1(5), 155R-168R. 86/1835-86/2039, J . Anal. At. Spectrom., 1986, 1(6), 193R-200R. 87/1-87/395, J. Anal. At. Spectrom., 1987, 2(1), 29R42R. 87/396-871637, J . Anal. At. Spectrom., 1987, 2(3), 69R-77R. 87/638-87/1169, J . Anal. At. Spectrom., 1987, 2(4), 115R-131R. 87/1170-87/1503, J . Anal. At. Spectrom., 1987, 2(5), 155R-166R. Abbreviated forms of the literature references quoted (excluding those to Conference proceedings) are given below for the convenience of readers. The full references, names and addresses of 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 8611396. Spectrochim. Acta, Part B, 1985, 40, 1227. 8611398. Spectrochim. Acta, Part B, 1985, 40, 1255. 8611463. Spectro- chim. Acta, Part B, 1985,40, 1447.8611468. Bull. Chem. SOC. Jpn., 1985, 58, 3259. 8611470. At. Spectrosc., 1985, 6 , 152. 8611471. At. Spectrosc., 1985, 6 , 157. 86/1603. Spectrochim. Acta, Part B, 1985,40, 1369. 8611604. Spectrochim. Acta, Part B, 1985, 40, 1379. 8611605. Spectrochirn. Acta, Part B , 1985, 40, 1457. 8611606. Spectrochim. Acta, Part B, 1985,40, 1467. 8611607. Spectrochim. Acta, Part B, 1985, 40, 1495. 8611608. Spectrochim. Acta, Part B, 1985, 40, 1525. 8611610. Spectro- chim.Acfa, Part B, 1985, 40, 1631. 8611611. Spectrochirn. Acta, Part B , 1985,40,1637.86/1612. Spectrochim. Acta, Part B, 1985, 40, 1651. 8611613. Spectrochim. Acta, Part B, 1985, 40, 1663. 8611614. Spectrochim. Acta, Part B, 1985, 40, 1677. 8611615. Spectrochim. Acta, Part B, 1985, 40, 1689. 86/1617. Anal. Chim. Acta, 1985, 177, 129. 8611622. Talanta, 1986,33, 75. 8611624. Anal. Chem., 1986, 58, 544. 8611626. Anal. Chem., 1986, 58, 642. 8611627. Anal. Chem., 1986, 58, 654. 8611628. Anal. Chem., 1986, 58, 656. 8611629. Anal. Chem., 1986, 58, 658. 8611631. Analyst, 1986, 111, 19. 8611633. Analyst, 1986, 111, 171. 8611634. Analyst, 1986, 111, 221. 8611638. Analyst, 1986, 111, 265. 8611639. Analyst, 1986, 111, 269. 8611640. Analyst, 1986, 111, 277. 8611642. Analyst, 1986, 111, 285.86/1645. Analyst, 1986, 111, 345. 8611647. Anal. Proc., 1985, 22, 371. 8611648. Anal. Proc., 1985, 22, 376. 86/1649. Anal. Proc., 1986, 23, 6. 8611650. Anal. Proc., 1986,23,8. 8611654. Anal. Proc., 1986,23,21. 8611655. Appl. Opt., 1985, 24, 4509. 8611656. Appl. Opt., 1986, 25, 13. 8611657. Appl. Opt., 1986,25,276. 8611658. Appl. Opt., 1986, 25, 291. 8611660. Appl. Opt., 1986, 25, 649. 8611661. Appl. Opt., 1986, 25, 740. 8611662. Appl. Opt., 1986, 25, 744. 8611663. Appl. Opt., 1986,25,749. 8611664. Appl. Spectrosc., 1986,40, xix. 8611665. Appl. Spectrosc., 1986,40,60.86/1669. Can. J . Spectrosc., 1985,30, 123. 8611670. Can. J . Spectrosc., 1985, 30, 135. 8611671. Can. J . Spectrosc., 1985, 30, 144. 8611672. Can. J . Spectrosc. , 1985, 30, 154. 8611675. Fresenius Z .Anal. Chem., 1985,322, 439. 8611676. Analyst, 1985,110, 431. 8611678. Anal. Chim. Acta, 1985, 176, 1. 8611679. Anal. Chim. Acta, 1985, 176, 17. 8611680. Analyst, 1985,110,419.86l1681. Vestn. Slov. Kern. Drus., 1985, 32, 283. 8611683. Huanjin Wuran Yu Fangzhi, 1985, 7(2), 33. 8611692. Jilin Dame Ziran Kexue Xuebao, 1985, (2), 90. 8611698. Fresenius 2. Anal. Chem., 1985, 322, 371. 8611701. Zh. Prikl. Spectrosk., 1985, 43, 377. 8611703. Guangpuxue Yu Guangpu Fenxi, 1985, 5(5), 47. 8611704. Anal. Chim. Acta, 1985, 175, 319. 8611705. Guangpuxue Yu Guangpu Fenxi, 1985, 5(5), 13. 8611706. Spectrosc. Lett., 1985, 18, 679. 8611707. Chem. Anal. (Warsaw), 1985, 30(1), 55. 8611708. Bunseki Kagaku, 1985, 34, 600. 8611713. Frese- nius Z . Anal. Chem., 1985, 322, 383. 8611715.Anal. Chim. Acta, 1985, 173, 315. 8611717. Zh. Anal. Khim., 1985, 40, 2152. 8611718. Anal. Sci., 1985, 1, 417. 8611721. Mikrochim.196R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 Acta, 1985, 1, 333. 8611723. Fresenius Z. Anal. Chem., 1985, 322, 551. 8611725. Prog. Anal. A t . Spectrosc., 1985, 8, 193. 8611726. Anal. Chim. Acta, 1985,173,321.8611727. ATOMKI Kozl., 1985, 27, 340. 8611728. Anal. Chim. Acta, 1985, 175, 231. 8611729. Anal. Chim. Acta, 1985, 175, 329. 8611730. Appl. Spectrosc., 1985, 39, 989. 8611731. Zh. Anal. Khim., 1985, 40, 1930. 8611732. Anal. Chim. Acta, 1985, 173, 63. 8611739. ATOMKI Kozl., 1985, 27, 361. 8611744. Guang- puxue Y u Guangpu Fenxi, 1985,5(5), 52. 8611745. Zh. Anal. Khim., 1985,40, 1978. 8611749.Fenxi Huaxue, 1985,13,858. 8611751. J . Chromatogr. Sci., 1985, 23, 465. 8611755. Spec- trosc. Lett., 1986, 19, 61. 8611758. Fresenius Z. Anal, Chem., 1985, 322, 743. 8611764. Fresenius Z. Anal. Chem., 1985,322,673.8611765. Fresenius Z. Anal. Chem., 1985, 322, 721. 8611767. Riv. Stn. Sper. Vetro (Murano, Italy), 1985, 15, 179. 8611770. Bunseki Kagaku, 1986,35,27.86/1775. Spectrosc. Lett., 1985,18,815. 8611776. Spectrosc. Lett., 1986, 19, 179. 8611777. Bunseki Kagaku, 1985,34, 682. 8611779. Anal. Chem., 1986, 58,366. 8611780. Anal. Chem., 1986, 58, 502. 8611781. Anal. Chem., 1986, 58, 511. 8611782. Appl. Spectrosc., 1985, 39, 1078. 8611783. Fresenius Z. Anal. Chem., 1985, 322, 555. 8611784. Fresenius Z. Anal. Chem., 1985, 322, 657. 8611785. Guangpuxue Y u Guangpu Fenxi, 1985, 5(5), 36.8611787. Anal. Chim. Acta, 1985, 176, 33. 8611790. Zh. Anal. Khim., 1985,40, 2173. 8611791. Spectrochim. Acta, Part B , 1985, 40, 1411. 8611792. Spectrochim. Acta, Part B , 1985, 40, 1473. 8611793,"Anal. Sci.", 1985, 1,291. 8611794. Fresenius Z. Anal. Chem., 1985,322, 704. 8611796. J. Anal. At. Spectrom., 1986, 1,35.86/1798. Wuhan Daxue Xuebao, Ziran Kexueban, 1985, (Anal. Chem. Spec. Ed.), 67. 8611803. Fresenius 2. Anal. Chem., 1985, 322, 713. 8611805. Anal. Chem., 1986, 58, 785. 8611809. Spectroscopy (Springfield, Oreg.), 1986, 1, 30. 8611812. Fresenius Z. Anal. Chem., 1985, 322, 654. 8611813. ACS Symp. Ser., 1986, 297(Chromatogr. Sep. Chem.), 137. 8611815. Prog. Anal. A t . Spectrosc., 1985, 8, 257. 8611817. Fresenius Z. Anal. Chem., 1985, 322, 563.8611819. Anal. Chem., 1986, 58, 802. 8611820. J. Anal. At. Spectrom., 1986, 1, 89. 8611821. Anal. Chem., 1986, 58, 797. 8611822. Anal. Chem., 1986, 58, 932. 8611823. Anal. Chem., 1986, 58, 923. 8611828. Fresenius Z. Anal. Chem., 1985, 322, 567. 8611831. Chem. Listy, 1985, 79, 1295. 8611834. Anal. Chem., 1986, 58, 790. 8611835. Appl. Spectrosc., 1986, 40, 156. 8611836. Appl. Spectrosc., 1986, 40, 181. 8611837. Appl. Spectrosc., 1986,40, 203. 8611839. Appl. Spectrosc., 1986,40, 246. 8611840. Appl. Spectrosc., 1986, 40, 265. 8611841. Appl. Spectrosc., 1986, 40, 274. 8611845. At. Spectrosc., 1986, 7(1), 1. 8611847. Anal. Biochem., 1986, 153, 305. 8611851. Lebensm.-Biotechnol., 1985, (2), 54. 8611854. J. Anal. At. Spectrom., 1986,1, 19. 8611860. Mater.Elektron., 1985, (1), 7. 8611862. Fresenius Z. Anal. Chem., 1985, 322, 660. 8611863. Appl. Spectrosc., 1985, 39, 930. 8611864. Spectrochim. Acta, Part B , 1985, 40, 1423. 8611865. Spectrochim. Acta, Part B , 1985, 40, 1437. 8611866. Spectrosc. Lett., 1986, 19, 141. 8611867. J. Anal. At. Spectrom., 1986, 1, 63. 8611870. Spectrochim. Acta, Part B 1985,40,1573.86/1871. J . Anal. A t . Spectrom., 1986, 1, 55. 8611875. Appl. Spectrosc., 1985, 39, 1042. 8611876. Spectrosc. Lett., 1985, 18, 781. 8611878. Zh. Anal. Khim., 1985, 40, 2191. 8611879. Anal. Sci., 1985, 1, 151. 8611880. Anal. Sci., 1985, 1, 169. 8611881. Spectrochim. Acta, Part B , 1985,40, 1485. 8611882. Anal. Sci., 1985,1,257.86/1886. Zh. Anal. Khim., 1986, 41, 80. 8611887. J. Anal. At. Spectrom., 1986, 1, 41.8611888. J. Anal. At. Spectrom., 1986, 1, 45. 8611889. J. Anal. At. Spectrom., 1986, 1, 85. 8611890. Can. J. Chem., 1986, 64, 119. 8611891. Anal. Chem., 1985, 57, 1979. 8611892. J. Anal. A t . Spectrom., 1986, 1,29. 8611893. J. Anal. At. Spectrom., 1986, 1, 59. 8611895. Spectrochim. Acta, Part B , 1985, 40, 1401. 8611896. Spectrochim. Acta, Part B , 1985, 40, 1539. 8611897. Spectrochim. Acta, Part B, 1985, 40, 1387. 8611903. Spectrosc. Lett., 1986, 19(2), 101. 8611904. Bunseki Kagaku, 1986,35(2), 122.8611908. Anal. Proc., 1985,22,382. 8611909. At. Spectrosc., 1986, 7(1), 9. 8611910, Appl. Spectrosc., 1985,39, 916. 8611911. Appl. Spectrosc., 1985,39, 920. 8611912. Appl. Spectrosc., 1985, 39, 925. 8611913. Spectrochim. Acta, Part B , 1985, 40, 1607. 8611914.Labor Praxis, 1985,9,1336.86/1915. J . Anal. At. Spectrom., 1986, 1, 75,8611916. High-Purity Mater. Sci. Technol., Int. Symp., 6th, 1985, Proc. 2, 77. 8611917. Appl. Spectrosc., 1985, 39, 935. 8611918. Anal. Chem., 1986,58 1264. 8611919. Anal. Chem., 1986,58,1143. 8611920. Spectroscopy (Springfield, Oreg.), 1986, 1, 39. 8611921. Bunseki Kagaku, 1985, 34, 781. 8611922. Anal. Chem., 1986, 58, 1140. 8611923. Finn. Chem. Lett., 1985, ( 5 ) , 186. 8611924. Fresenius Z. Anl. Chem., 1985, 322, 687. 8611925. Fresenius Z. Anal. Chem. ., 1985, 322, 728. 8611928. Zh. Anal. Khim., 1986, 41, 46. 86J1930. J. Anal. At. Spectrom., 1986, I , 23. 8611934. Chem. Express, 1986, 1, 149. 8611938. Anal. Chem., 1986, 58, 1272. 8611944. Appl. Spec- trosc., 1986,40,379. 8611947. Appl.Spectrosc., 1985,39,968. 8611949. Anal. Sci., 1985, 1, 157. 8611950. Fresenius Z. Anal. Chem., 1986, 323,50. 8611960. Anal. Chem., 1986,58, 124R. 8611961. Anal. Chem., 1986, 58, 335R. 8611962. Chem. Br., 1986, 22, 123. 8611980. Anal. Proc., 1986, 23, 109. 8611984. Analyst, 1986,111,651. 8611987. ICP Inf. Newsl., 1986,12(1), 1. 8611988. Appl. Spectrosc., 1986, 40, 291. 8611990. Appl. Spectrosc., 1986,40, 351. 8611992. Appl. Spectrosc., 1986,40, 386. 8611993. Spectrochim. Acta, Part B , 1985,40,1331.86/2005. Chem. Br., 1986,22,119.86/2006. Wutan Y u Huutan, 1985,9, 250. 8612011. J. Anal. At. Spectrom., 1986, 1, 51. 8612012. Spectrochim. Acta, Part B , 1986, 41, 143. 8612014. Appl. Spectrosc., 1986, 40, 4. 8612015. Spectrochim. Acta, Part B , 1986, 41, 49. 8612016.Spectrochim. Acta, Part B , 1986, 41, 125. 8612017. Spectrochim. Acta, Part B , 1986, 41, 257. 8612021. Fenxi Huaxue, 1985, 13, 879. 8612027. Anal. Chem., 1986, 58, 1462. 8612032. Talanta, 1986, 33, 279. 8612023. Zh. Prikl. Spektrosk., 1986, 44, 140. 8711. Spectrochim. Acta, Part B , 1985, 40, 1505. 8712. Spectrochim. Acta. Part B , 1985, 40, 1517. 8713. Can. J. Spectrosc., 1986, 31, 6. 8715. Fenxi Huaxue, 1986, 14, 110. 8716. Fenxi Huaxue, 1986, 14, 119. 8717. Fenxi Huaxue, 1986, 14, 132. 8718. Fenxi Huaxue, 1986, 14, 151. 8719. Talanta, 1986, 33, 358. 87111. Talanta, 1986, 33, 445. 87112. Talanta, 1986, 33, 458. 87113. Anal. Chem., 1986, 58, 1340. 87115. Anal. Chem., 1986, 58, 1334. 87/19. Int. J. Environ. Anal. Chem., 1986, 24, 267. 87/23. Anal. Chem., 1986, 58, 697A.87/24, Spectrochim. Acta, Part B , 1986, 41, 3. 87/27. Spectrochim. Acta, Part B , 1986, 41, 39. 87/28. Spectrochim. Acta, Part B, 1986, 41, 115. 87/29. Appl. Spectrosc., 1986, 40, 434. 87/30. Appl. Spectrosc., 1986, 40, 445. 87132. Appl. Spectrosc., 1986, 40, 464. 87/33, Appl. Spectrosc., 1986, 40, 473. 87/34. Appl. Spectrosc., 1986, 40, 477. 87/35. Appl. Spectrosc., 1986, 40, 491. 87136. Appl. Spectrosc., 1986, 40, 494. 87/38. Appl. Spectrosc., 1986, 40, 567. 87139. Analyst, 1986,111, 111. 87141. Spectrochim. Acta, Part B , 1986,41,63. 87143. Spectrochim. Acta, Part B , 1986, 41, 105. 87146. J. Anal. At. Spectrom., 1986, 1, 119. 87155. Anal. Chem., 1986, 58, 1112. 87/58. Anal. Chem., 1986, 58, 1696. 87/59. Anal. Chem., 1986, 58, 1734. 87/60, Anal. Chem., 1986, 58, 1739.87164. Spectrochim. Acta, Part B , 1986, 41, 27. 87165. Spectrochim. Acta, Part B, 1986,41, 133. 87166. Spectrochim. Acta, Part B. 1986,41, 151. 87167. Spectrochim. Acta, Part B , 1986, 41, 169. 87/68. Spectrochim. Acta, Part B , 1986,41,175. 87170. Spectrochim. Acta, Part B , 1986, 41, 197. 87/71. Spectrochim. Acta, Part B , 1986,41,205. 87172. Spectrochim. Acta, Purt B, 1986,41,217. 87173. Spectrochim. Acta, Part B , 1986, 41, 227. 87/75. Spectrochim. Acta, Part B , 1986,41,275. 87/76 Spectrochim. Acta, Part B, 1986, 41,247. 87/78. Spectrochim. Acta, Part B, 1986,41,283.87/79. Spectrochim. Acta, Part B , 1986,41.291. 87/88. J. Chromatogr., 1986, 351, 465. 87/89. Spectrochim.JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 197R Acta, Part B , 1986, 41, 335.87/90. Analusis, 1986, 14, 107. 87193. Stahl Eisen, 1986, 106, 167. 87/97. Scr. Fac. Sci. Nat. Univ. Purkynianae Brun., 1985, 15, 491. 87199. Guangpuxue Yu Guangpu Fenxi, 1985, 5(3), 23. 871100. Guangpuxue Yu Guangpu Fenxi, 1985, 5(3), 55. 871103. Rep. - MINTEK, 1985, M231, 21 pp. 871104. Fenxi Huaxue, 1986, 14, 198, 871105. Anal. Chem., 1986, 58, 975. 871106. Spectrochim. Acta, Part B , 1985, 40, 1555. 871108. Anal. Chim. Acta, 1986, 180, 69. 871109. Anal. Chim. Acta, 1986, 180, 163. 871110. Anal. Chim. Acta, 1986, 180, 357. 871111. Anal. Chim. Acta, 1986, 180, 373. 871113. Spectrochim. Acta, Part B , 1986,41,317.87/115. Spectrochim. Acta, Part B , 1986,41,349.871116. Spectrochim. Acta, Part B , 1986, 41, 361. 871117. Spectrochim.Acta, Part B , 1986, 41, 377. 871118. Spectrochim. Acta, Part B , 1986,41, 391. 871119. Spectrochim. Acta, Part B, 1986,41,407.87/120. Spectrochim. Acta, Part B, 1986,41,415.87/121. Spectrochim. Acta, Part B , 1986, 41, 431. 871122. Spectrochim. Acta, Part B , 1986, 41, 439. 871123. Spectrochim. Acta, Part B , 1986,41,453. 871124. Spectrochim. Acta, Part B , 1986,41,469.871125. Spectrochim. Acta, Part B , 1986,41,475.87/126. Spectrochim. Acta, Part B , 1986, 41, 487. 871127. Spectrochim. Acta, Part B, 1986, 41, 503. 871129. Spectrochim. Acta, Part B , 1986,41, 547. 871130. Spectrochim. Acta, Part B , 1986,41,567.87/131. Spectrochim. Acta, Part B , 1986,41,591.871132. Spectrochim. Acta, Part B , 1986, 41, 597. 871133. Spectrochim. Acta, Part B , 1986, 41, 619.871231. ICP Inf. Newslett., 1986,12, 177.871232. ICP Inf. Newslett., 1986, 12, 170. 871256. Wiss. Z . - Karl-Marx-Univ. Leipzig, Math.-Naturwiss. Reihe, 1986,35,70.87/258. Guang- puxue Yu Guangpu Fenxi, 1985, 5(3), 49. 871260. Zh. Anal. Khim., 1986, 41, 402. 871265. Guangpuxue Yu Guangpu Fenxi, 1985, 5(3), 16. 871266. J. Anal. At. Spectrom., 1986, 1, 115. 871269. Zavod. Lab., 1986, 52(4), 9. 871275. Guangpuxue Yu Guangpu Fenxi, 1986, 6, 38. 871276. Guangpuxue Yu Guangpu Fenxi, 1986, 6, 46. 871286. Guangpuxue Yu Guangpu Fenxi, 1986,6,1.87/287. Spectrochim. Acta, Part B , 1986, 41, 403. 871288. Talanta, 1986,33,577. 871292. Talanta, 1986, 33, 705. 871297. At. Spectrosc., 1986, 7(2), 49. 871306. Bunseki Kagaku, 1986, 35, 499. 871318. Fresenius Z . Anal. Chem., 1986, 323, 742.871319. Wiss. Z . - Karl-Marx-Univ. Leipzig, Math. -Naturwiss. Reihe, 1986, 35, 82. 871329. J. Anal. At. Spectrom., 1986, 1, 131. 871337. Guangpuxue Yu Guangpu Fenxi, 1985, 5 ( 5 ) , 66. 871339. Anal. Chim. Acta, 1986, 179, 487. 871347. Fresenius Z . Anal. Chem., 1986, 323, 759. 871356. Anal. Chem., 1986, 58, 2084. 871357. Zh. Prikl. Spektrosk., 1986,44, 728. 871361. Rev. Cubana Quim., 1985, 1(3), 73. 871364. Fresenius Z . Anal. Chem., 1986, 323, 681. 871365. Analyst, 1986, 111, 419. 871367. Anal. Sci., 1986, 2, 109. 871369. Uzb. Khim. Zh., 1986, ( l ) , 25. 871370. Anal. Chem., 1986, 58, 1973. 871371. J. Anal. At. Spectrom., 1986, 1,105. 871374. Anal. Sci., 1986,2(2), 119.871377, Anal. Chim. Acta, 1986, 183, 217. 871378. Anal. Chim. Acta, 1986, 183, 225.871383. Can. J. Spectrosc., 1986, 31(2), 35. 871385. Zh. Prikl. Spektrosk., 1986, 44, 670. 871386. J. Anal. At. Spec- trom., 1986, 1, 149. 871387. Phys. Scr., 1986,33,429. 871389. Anal. Chim. Acta, 1986, 179, 481. 871391. Fresenius Z . Anal. Chem., 1986, 323, 703. 871392. Finn. Chem. Lett., 1985, (6), 246. 871393. J. Geochern. Explor., 1986, 25, 367. 871394. Zh. Anal. Khim., 1986, 41, 805. 871396. Fresenius Z. Anal. Chem., 1986, 323, 737. 871407. Eisei Kagaku, 1985,31,391. 871410. Anal. Chim. Acta, 1986, 181, 187. 871413. Freiberg. Forschungsh. A , 1986, 730, 130. 871416. J. Anal. At. Spectrorn., 1986, 1, 171. 871418. Zavod. Lab., 1986, 52(6), 20. 871419. Fresenius Z. Anal. Chem., 1986, 323, 697. 871420. Fresenius Z. Anal. Chem., 1986, 323, 771. 871421. Fresenius Z.Anal. Chem., 1986, 323, 783. 871423. Anal. Chim. Acta, 1986, 181, 169. 871424. Fresenius Z. Anal, Chem., 1986,323,754. 871425. Fresenius Z . Anal. Chem., 1986, 323, 762. 871426. Stahl Eisen, 1986, 106, 575. 871427. Bunseki Kagaku, 1986, 35, 530. 871428. Anal. Chim. Acta, 1986, 181,195. 871429. Fresenius Z. Anal. Chem. 1986, 323, 689. 871430. Fresenius Z . Anal. Chem., 1986, 323, 726.871431. Fresenius 2. Anal. Chem., 1986,323,730.871432. Fresenius Z . Anal. Chem., 1986,323,767.871433. Fresenius Z. Anal. Chem., 1986, 323, 788. 871434. Fresenius Z. Anal. Chem., 1986, 323, 793. 871435. Comm. Eur. Communities, [Rep.] EUR, 1986, EUR 10141, 51 pp. 871437. Bunseki Kagaku, 1986, 35, 553. 871441. At. Spectrosc., 1986,7(3), 69.871460. Guangpuxue Yu Guangpu Fenxi, 1986, 6(1), 1. 871461. Prog. Anal. Spectrosc., 1986, 9, 167. 871463. Fresenius Z . Anal. Chem., 1986, 323, 710. 871464. Anal. Chem., 1986, 58, 2342. 871465. Bunseki Kagaku, 1986, 35, 548. 871471. Fenxi Huaxue, 1986,14,265. 871477. Anal. Chim. Acta, 1986, 182, 231. 871480. Proc. SPIE-Int. SOC. Opt. Eng., 1986, 644(Remote Sens.), 7. 871481. Proc. SPIE-Int. SOC. Opt. Eng., 1986, 644(Remote Sens.), 13. 871488. Analyst, 1985, 110, 1413. 871510. Bunseki, 1986, (6), 407.871512. Appl. Spectrosc., 1986,40,667.871513. Phys. Scr., 1986, 34, 18. 871514. Spectroscopy (Springfield, Oreg.), 1986, 1(8), 18. 871515. TrAC, Trends Anal. Chem. (Pers. Ed.), 1986, 5 ( 5 ) , 3 10. 871516. ChemSA, 1986, 12(4), 115. 871518. LP Spec.: Chromatogr., Spektrosk., 1986, 188. 871520. Fresenius 2. Anal. Chem., 1986, 323, 716. 871521. J. Anal. At. Spectrom., 1986, 1, 195. 871522. J. Anal. At. Spectrom., 1986, 1,203. 871523. J. Anal. At. Spectrom., 1986, 1, 237. 871524. Fenxi Huaxue, 1986, 14, 273. 871527. Fenxi Huaxue, 1986, 14, 288. 871585. Guangpuxue Yu Guangpu Fenxi, 1986, 6(3), 33. 871589. Fresenius Z . Anal. Chem., 1986, 324, 442. 871590. Fresenius Z . Anal. Chem., 1986,324,472.871591. J. Anal. At. Spectrom., 1986, 1, 185. 871592. J. Anal. At. Spectrom., 1986, 1, 227. 871594. Fresenius Z . Anal. Chem., 1986, 324, 448. 871595. Spectrochim. Acta, Part B , 1986, 41, 639. 871596. Spectrochim. Acta, Part B , 1986,41,683.87/597. Spectrochim. Acta, Part B , 1986,41,713.871598. Spectrochim. Acta, Part B , 1986, 41, 725. 871599. Anal. Chem., 1986, 58, 2558. 871600. Spectrochim. Acta, Part B , 1986, 41, 699. 871604. Zavod. Lab., 1986, 52(6), 29. 871605. Zavod. Lab., 1986, 52(6), 32. 871606. Steel Founders Res. J . , 1986, 14,31. 871609. Zh. Anal. Khim., 1986, 41, 1173. 871612. Spectrochim. Acta, Part B , 1986, 41, 669. 871615. Spectrochim. Acta, Part B , 1986, 41, 651. 871616. Spectrochim. Acta, Part B , 1986,41,751. 871617. Spectrochim. Acta, Part B , 1986,41,761.871619. Spectrochim. Acta, Part B , 1986,41,797.87/620. Spectrochim. Acta, Part B , 1986, 41, 817. 871621. Spectrochim. Acta, Part B, 1986, 41, 825. 871623. Spectrochim. Acta, Part B , 1986,41,853. 871624. Spectrochim. Acta, Part B , 1986,41,865.871625. Spectrochim. Acta, Part B , 1986, 41, 875. 871626. Spectrochim. Acta, Part B , 1986, 41, 889. 871627. Spectrochim. Acta, Part B , 1986,41,907.87/628. Spectrochim. Acta, Part B , 1986,41,925.87/629. Spectrochim. Acta, Part B , 1986, 41, 935. 871630. Spectrochim. Acta, Part B, 1986, 41, 947. 871631. Spectrochim. Acta, Part B , 1986,41,959. 871632. Spectrochim. Acta, Part B , 1986,41,967.871633. Spectrochim. Acta, Part B , 1986,41,979.87/634. Spectrochim. Acta, Part B , 1986, 41, 991. 871635. Spectrochim. Acta, Part B , 1986, 41, 999.871636. Spectrochim. Acta, Part B , 1986,41,1007.87/637. Spectrochim. Acta, Part B , 1986, 41, 1015. 871642. Analyst, 1986,111,901.871643. Analyst, 1986,111,1029.87l645. Appl. Spectrosc., 1986, 40, 729. 871646. Appl. Spectrosc., 1986, 40, 759. 871647. Appl. Spectrosc., 1986, 40, 766. 871648. Appl. Spectrosc., 1986, 40, 804. 871651. Appl. Spectrosc., 1986, 40, 841. 871652. Appl. Spectrosc., 1986, 40, 857. 871653. Appl. Spectrosc., 1986, 40, 863. 871654. Appl. Spectrosc., 1986, 40, 877.871663. Fresenius Z. Anal. Chem., 1986,324,511. 871664. Fresenius Z . Anal. Chem., 1986,324,519.871665, Fresenius Z. Anal. Chem., 1986, 324, 561. 871666. Anal. Chem., 1986, 58, 1139A. 871667. Anal. Chem., 1986, 58, 1023A. 871669. Fresenius Z. Anal. Chem., 1986, 324, 745. 871670. Spectro- scopy (Springfield, Oreg.), 1986,1(9), 34.871671. Fresenius Z. Anal. Chem., 1986, 324, 793. 871672. Fresenius Z. Anal.198R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 Chem., 1986, 324, 683. 871673. Analyst, 1986,111, 1113.871675.Analyst, 1986,111, 1143. 871685. Yankuang Ceshi, 1986,5(1), 22.871689. J . Anal. At. Spectrom., 1986, 1, 287. 871693. Fukuoka Joshi Diagaku Kaseigakubu Kiyo, 1986, 17, 11. 871917. Kokuritsu Kogai Kenkyusho Kenkyu Hokoku, 1986, 100, 3. 871918. Bunseki, 1986, (8), 547. 871919. Anal. Chim. Acta, 1986, 184, 299. 871921. Fresenius 2. Anal. Chem., 1986, 324, 807. 871922. Fresenius Z. Anal. Chem., 1986, 324, 846. 871927. Zh. Prikl. Spektrosk., 1986, 45, 280. 871928. Fresenius 2. Anal. Chem., 1986, 324, 832. 871930. J. Anal. At. Spectrom., 1986, 1, 359. 871931. J. Anal. At. Spectrom., 1986, 1, 265. 871932. J. Anal. At. Spectrom., 1986, 1, 273. 871937. Yankuang Ceshi, 1986, 5(1), 1. 871944. Yankuang Ceshi, 1986, 5(1), 63. 871947. J. Anal. At. Spectrom., 1986, 1, 277. 871949. Anal. Chim. Acta, 1986, 184, 213. 871950. At. Spectrosc., 1986, 7(4), 89. 871953. Bunseki Kagaku, 1986,35, 609. 871955. Appl. Opt., 1986,25, 3242. 871957. Spectrochim. Acta, Part B, 1986 41, 1025. 871958. Spectrochim. Acta, Part B , 1986, 41, 1043. 871959. Spectrochim. Acta, Part B , 1986, 41, 1063. 871960. Spectro- chim. Acta, Part B , 1986,41, 1075.871961. Spectrochim. Acta, Part B , 1986 41, 1089. 871964. Spectrochim. Acta, Part B , 1986, 41, 1139. 871965. Spectrochim. Acta, Part B , 1986, 41, 1151. 871968. S. Afr. J. Chem., 1986, 39(1), 1. 871975. Zh. Anal. Khim., 1986, 41,411. 8711170. ICP I f . Newsl., 1986,7,467. 8711176. Australian Standard 2883, 1986, 7, 14pp.. 8711182. Spectrosc. Lett., 1986, 19, 791. 8711184. J. Anal. At. Spectrom., 1986, 1, 297. 8711 187. Can. J . Spectrosc., 1986, 31(4), 95.8711195. Guangpuxue Yu Guanpu Fenxi, 1986,6(4), 56. 8711196. Anal. Chem., 1986, 58,2606. 8711197. Zh. Anal. Khim., 1986,41, 1361. 8711198. J . Anal. At. Spectrom., 1986, 1, 355. 8711199. Anal. Chem., 1986, 58, 2594. 8711203. Anal. Chem., 1986,58,2598.8711204. Anal. Chem., 1986,58,2614. 8711206. Bunseki Kagaku, 1986, 35, 685. 8711209. Bunseki Kagaku, 1986,35, 701. 8711212. Kokuritsu Kogai Kenkyusho Kenkyu Hokoku, 1986, 100,21. 8711213. Steel Res., 1986,57, 427.8711214. Guangpuxue Yu Guangpu Fenxi, 1986,6(4), 41. 8711222. Spectrochim. Acta, Part B , 1986, 41, 1157. 8711223. Spectrochim. Acta, Part B , 1986, 41, 1167. 8711224. Spectrochim. Acta, Part B , 1986, 41, 1175. 8711227. Spectrochim. Acta, Part B , 1986, 41, 1217. 8711228. Can. J. Spectrosc., 1986, 31(4), 77. 8711244. Tetsu to Hagane, 1986, 72, 1759. 8711249. Appl. Spectrosc., 1986, 40, 971. 8711251. Fenxi Huaxue, 1986, 14, 549. 8711252. Chem. Inz. Chem., 1986, 16, 75 . 8711254. Fresenius 2. Anal. Chem., 1986, 325, 95. 8711255. Appl. Spectrosc., 1986, 40, 939. 8711256. Appl. Spectrosc., 1986, 40, 944. 8711257. Appl. Spectrosc., 1986,40,949. 8711258. Spectrochim. Acta, Part B , 1986,41,1055.8711259. Anal. Chem., 1986,58,3108.8711260. Anal. Chem., 1986,58,3115. 8711261. Anal. Chem., 1986,58, 3263. 8711262. Anal. Chem., 1986, 58, 3244. 8711265. Anal. Chem., 1986, 58, 3095. 8711266. Appl. Spectrosc., 1986, 40, 968. 8711268. Anal. Chem., 1986, 58, 3122. 8711272. Appl. Spectrosc. , 1986,40, 1074.8711275. Spectroscopy (Springfield, Oreg.), 1986, 1(10), 49. 8711290. Bunseki Kagaku, 1986, 35, 824. 8711295. J. Anal. At. Spectrom., 1986, 1, 337. 8711296. Guangpuxue Yu Guangpu Fenxi, 1986, 6(4), 30. 8711304. Fresenius Z . Anal. Chem., 1986, 325, 255. 8711310. Bunko Kenkyu, 1986, 35, 42. 8711314. Wiss. Z. Karl-Marx-Univ. Leipzig, Math. -Naturwiss. Reihe, 1986, 35, 70. 8711318. ICP Inf. Newsl., 1986, 12, 243. 8711319. Talanta, 1986, 33, 875. 8711436. Spectroscopy (Springfield Oreg.), 1986, 1(11), 20. 8711438. Guangpuxue Yu Guangpu Fenxi, 1986, 6, 53. 8711443. Bunseki Kagaku, 1986, 35, 651. 8711445. Bunseki Kagaku, 1986, 35, 662. 8711446. Bunseki Kagaku, 1986, 35, 668. 8711449. Fenxi Huaxue, 1986, 14, 593. 8711457. At. Spectrosc., 1986, 7, 155. 8711461. Fresenius 2. Anal. Chem., 1986, 325, 396. 8711464. Spectrochim. Acta, Part B , 1986,41,1225.8711465. Spectrochim. Acta, Part B , 1986, 41, 1235. 8711467. Spectrochim. Acta, Part B , 1986, 41, 1287. 8711468. Spectrochim. Acta, Part B , 1986, 41, 1299. 8711469. Spectrochim. Acta, Part B , 1986, 41, 1323. 8711470. Spectrochim. Acta, Part B , 1986, 41, 1347. 8711472. Spectrochim. Acta, Part B , 1986, 41, 1367. 8711473. Anal. Chim. Acta, 1986,186, 147. 8711474. Anal. Chim. Acta, 1986, 186, 155. 8711484. Talanta, 1987, 34, 191. 8711485. Talanta, 1987, 34, 197. 8711486. Hua Hsueh, 1986, 44(3), 90. 8711498. Fresenius 2. Anal. Chem. 1986, 325, 171. 8711501. Appl. Spectrosc., 1986, 40, 1073.

ISSN:0267-9477    

DOI:10.1039/JA987020167R

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 199R ATOMIC SPECTROMETRY UPDATE REFERENCES The address given in a reference is that of the first named author and is not necessarily the same for any co-author. 8711504. 8711505. 8711506. 8711507. 8711508. 8711509. 8711510. 87/15 11. 8711512. 87/1513. 8711514. 8711 5 15. 87/15 16. Voncken, J. H. L., Vriend, S. P., Kocken, J. W. M., Jansen, J. B. H., Determination of beryllium and its distribution in rocks of the Sn - W granite of Regoufe, Northern Portugal, Chem. Geol., 1986,56,93. (Inst. Earth Sci., Dept. Geochem., 3508 TA Utrecht, The Nether- lands). Hall, G. E. M., Vaive, J. E., Ballantyne, S. B., Field and laboratory procedures for determining gold in natural waters: relative merits of pre-concentration with activated charcoal, J.Geochem. Explor. , 1986,26, 191. (Geological Surv. Can., 601 Booth St., Ottawa, Ontario K1A OE8, Canada). Victor, A. H., Accurate determination of cobalt in South African primary and secondary geochemical reference materials by cation-exchange chromatography and atomic absorption spectrometry, Geostand. Newsl., 1986, 10, 13. (Natl. Chem. Res. Lab., CSIR, PO Box 395, Pretoria 0001, South Africa). Anderson, J., Victor, A. H., Determination of cobalt in South African primary and secondary reference samples by ion-exchange chromatography and electrothermal atomic absorption spec tropho tome try, Geostand. Newsl. , 1986,10,27. (Natl. Chem. Res. Lab. , CSIR, PO Box 395, Pretoria 0001 South Africa). Terashima, S., Determination of arsenic and antimony in eighty-five geochemical reference samples by automated hydride generation and electrothermal atomic absorption spectrometry, Geostand.Newsl., 1986, 10, 127. (Geol. Surv. Japan, 1-1-3 Higashi, Yatabe, Tsukuba, Ibaraki 305, Japan). Roelandts, I., Michel, G., Sequential inductively coupled plasma determination of some rare earth elements in five French geostandards, Geostand. Newsl., 1986, 10, 135. (Geology, Petrology and Geochemistry, Univ. Liege, B 4000 Sart-Tilman, Liege 1, Belgium). Kontas, E., Niskavaara, H., Virtasalo, J., Flameless atomic absorption determination of gold and palladium in geological reference samples, Geostand. Newsl., 1986,10, 169. (Geochem. Dept., Geol. Surv. Finland, PO Box 77, SF-96101 Rovaniemi, Finland). Toyoda, K., Haraguchi, H., Rare earth elements in six new GSJ standard rock samples as determined by inductively coupled plasma atomic emission spectrometry, Geostand.Newsl., 1986, 10, 173. (Dept. Chem., Fac. Sci., Univ. Tokyo, Bunkyo-ku, Tokyo 113, Japan). Flanagan, F. J., Reference samples in geology and geochemistry, Geostand. Newsl. , 1986,10,191. (US Geol. Surv., Reston, USA). Bysouth, S. R., Tyson, J. F., On-line sample and standard manipulation for flame atomic absorption spectrometry, Anal. Proc., 1986,23,412. (Dept. Chem., Univ. Technol., Loughborough, Leicestershire LEll 3TU, UK). Sparkes, S., Ebdon, L., Slurry atomisation for agricultural samples by plasma emission spectrometry, Anal. Proc., 1986, 23, 410. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth? Devon PL4 8AA, UK). Norman, P., Ebdon, L., Computer-controlled optimisa- tion of an inductively coupled plasma, Anal.Proc., 1986, 23,420. (Dept. Environ. Sci. , Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Egila, J. N., Littlejohn, D., Ottaway, J. M., Xiao-quan, S., Clinical applications of electrothermal atomic absorption spectrometry with Zeeman-effect background correction, Anal. Proc., 1986,23,426. (Dept. Pure and Appl. Chem., Univ. Strathclyde, 295 Cathedral St., Glasgow G1 lXL, UK). 871 871 871 517. 518. 519. 8711520. 8711521. 8711522. 8711523. 8711524. 8711525, 8711526. 8711527. 8711528. Cook, S. W., Littlejohn, D., Ottaway, J. M., Fell, G. S., Low resolution monochromator system for electrothermal atomic emission spectrometry with computer controlled background correction, Anal.Proc., 1986,23,429. (Dept. Pure and Appl. Chem., Univ. Strathclyde, 295 Cathedral St., Glasgow G1 lXL, UK). Al-Sowdani, K. H., Candoluminescence spectrometry with a vidicon detector, Anal. Proc., 1986, 23, 432. (Chem. Dept., Univ. Hull, Hull HU6 7RX, UK). Allenby, P., A user’s view of inductively coupled plasma mass spectrometry in routine analysis, Anal. Proc., 1987, 24, 12. (Tech. Dept., British Nuclear Fuels plc, Spring- fields Works, Salwick, Preston, Lancashire PR4 0x4, UK). Analytical Methods Committee, Report by the Analytical Methods Committee. Evaluation of analytical instrumen- tation. Part IV. Monochromators for use in emission spectrometry with ICP sources, Anal. Proc., 1987, 24, 3. (Royal Society of Chemistry, Burlington House, Piccad- illy, London W1V OBN, UK).Fulford, J. E., Gale, B. C., Trace element analysis by inductively coupled plasma mass spectrometry, Anal. Proc., 1987, 24, 10. (SCIEX, 55 Glen Cameron Rd., Thornhill, Ontario L3T 1P2, Canada). Berry, T., Macleod, K. C., Inductively coupled plasma atomic emission spectrometry (ICP-AES) source housed in a glove box for alpha-active material containment, Anal. Proc., 1987, 24, 18. (United Kingdom Atomic Energy Authority (Northern Division), Dounreay Nuclear Power Development Establishment, Thurso, Caithness KW14 7TZ, UK). Ahmed, R., *Stoeppler, M., Decomposition and stability studies of methylmercury in water using cold vapour atomic absorption spectrometry, Analyst, 1986,111,1371. (Inst. Appl. Phys. Chem., Chem.Dept., Nuclear Research Centre, Julich (KFA), PO Box 1913, D-5170 Julich, FRG). de la Guardia, M., Salvador, A., Bayarri, P., Farre, R., Rapid atomic spectrometric determination of sodium, potassium, calcium and magnesium in powdered milk by direct dispersion, Analyst, 1986, 111, 1375. (Dept. Quim. Anal., Facultad de Quimicas, Burjasot, Valencia, Spain). Ebdon, L., Hill, S. J., Ward, R. W., Directly coupled chromatography - atomic spectroscopy. Part 2. Directly coupled liquid chromatography - atomic spectroscopy. A review, Analyst, 1987, 112, 1. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Valkirs, A. O., Seligman, P. F., Olson, G. J., Brinckman, F. E., Matthias, C. L., Bellama, J. M., Di- and tributyltin species in marine and estuarine waters.Inter-laboratory comparison of two ultratrace analytical methods employ- ing hydride generation and atomic absorption or flame photometric detection, Analyst, 1987, 112, 17. (Marine Environment Branch, Naval Ocean Systems Center, San Diego, CA 92152, USA). Bettinelli, M., Baroni, U., Pastorelli, N., Determination of scandium in coal fly ash and geological materials by graphite furnace atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry, Analyst, 1987,112,23. (Central Laboratory, ENEL-DCO, Via Nino Bixio 39, 29100 Piacenza, Italy). Halls, D. J., Mohl, C., Stoeppler, M., Application of rapid furnace programmes in atomic absorption spectrometry to the determination of lead, chromium and copper in digests of plant materials, Analyst, 1987, 112, 185.(Trace Metals Unit, Dept. Biochem., Royal Infirmary, Glasgow G4 OSF, UK) .200R 8711529. 8711 5 30. 8711531. 8711532. 8711533. 8711534. 8711535. 8711536. 871 1537. 8711538. 8711539. 8711540. 8711541. 8711 542. 871 1543. 8711544. JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 Mohammed, D. A., Determination of chromium by electrothermal atomisation atomic absorption spec- trometry, Analyst, 1987, 112, 209. (Iraqi Atomic Energy Commission, PO Box 765, Twuaitha, Baghdad, Iraq). Ishiguro, Y., Goto, K., Kobayashi, Y., Nakashima, R., Shibata, S., Determination of trace amounts of lanthanum in animal tissues, especially in teeth and bones, Nagoya Kogyo Gijutsu Shikensho Hokoku, 1986,35(3), 97. (Gov.Ind. Res. Inst., Nagoya 462, Japan). Filippelli, M., Determination of trace amounts of organic and inorganic mercury in biological materials by graphite furnace atomic absorption spectrometry and organic mer- cury speciation by gas chromatography, Anal. Chem., 1987, 59, 116. (Lab. Chim. Ig. Profil., 1-19100 La Spezia, Italy). Arai, F., Determination of triethyllead, diethyllead and inorganic lead in urine by atomic absorption spectrometry, Ind. Health, 1986, 24, 139. (Sch. Med., St. Marianna Univ., Kawasaki 213, Japan). Lowenstein, F. W., Stanton, M. F., Serum magnesium levels in the United States, J. Am. Coll. Nutr., 1986, 5 , 399. (Nutr. Consult., Silver Spring, MD 20906, USA). Habashi, F., Zailaf, M., Awadalla, F. T., Determination of the total lanthanides in phosphate rock, Fresenius 2.Anal. Chem., 1986, 325, 479. (Dept. Min. Metall., Lava1 Univ., Quebec City, PQ, G1K 7P4, Canada). Kozynda, Yu. A., Kritsuk, I. N., Effectiveness of the X-ray spectral method during prospecting for ore deposits, Razved. Okhr. Nedr., 1986, (lo), 20. (LGI, USSR). Beckwith, P. M., Mullins, R. L., Coleman, D. M., Analysis of eastern coal fly ash using separated sampling and excitation atomic emission spectrometry, Anal. Chem., 1987, 59, 163. (Detroit Edison Co., Detroit, MI 48210, USA). Pettine, M., Liberatori, A., Mastroianni, D., Determina- tion of selenium in different oxidation states, Metodi Anal. Acque, 1986, 6(2), 16. (1st. Ric. Acque, CNR, Rome, Italy). Yang, X., Yang, Y., Determination of trace elements in groundwater with inductively coupled plasma atomic emission spectrographic analysis, Xiangtan Daxue Ziran Kexue Xuebao, 1986, (l), 118.(Xiangtan Univ., China). McElnay, J. C., D’Arcy, P. F., Aluminium content of infusion and irrigation fluids, Int. J . Pharm., 1986,33,261. (Med. Biol. Cent., Queen’s Univ. Belfast, Belfast BT9 7BL, UK). Hickman, D. A., Rooke, J. M., Thompson, M., Atomic Spectrometry Update-minerals and refractories, J . Anal. At. Spectrom., 1986, 1, 169R. (Metropolitan Police Forensic Sci. Lab., 109 Lambeth Rd., London SE1 7LP, UK). Dean, J. R., Snook, R. D., A study of the formation of atoms and dry aerosols above a graphite rod sample introduction device used for inductively coupled plasma atomic emission spectrometry, J . Anal. At. Spectrom., 1986, 1, 461. (Dept. Chem., Imperial Coll.Sci. Technol., London SW7, UK). White, J. S., Scheeline, A., Sampling and excitation of refractory solids with a theta pinch discharge designed as an atomic emission source, Anal. Chem., 1987, 59, 305. (Sch. Chem. Sci., Univ. Illinois, Urbana, IL 61801, USA). Martinez-Jimenez, P., Gallego, M., Valcarcel, M., Analy- tical potential of continuous precipitation in flow injection atomic absorption configurations, Anal. Chem., 1987, 59, 69. (Fac. Sci., Univ. Cordoba, Cordoba, Spain). Ramsey, J. M., Whitten, W. B., Degenerate four-wave mixing as a spectrochemical analysis technique, Anal. Chem., 1987,59,167. (Oak Ridge Natl. Lab., Oak Ridge, TN 37831, USA). 8711545. 8711 546. 8711547. 8711548. 8711549. 8711 550. 8711551. 8711552. 8711553. 8711554.871 871 555. 556. 8711 557. Davis, L. A., Winefordner, J. D., Evaluation of a Voigt effect coherent forward scattering atomic spectrometer, Anal. Chem., 1987,59,309. (Dept. Chem., Univ. Florida, Gainesville, FL 3261 1, USA). Hashitani, H., Yoshida, H., Adachi, T., Izawa, K., Wet oxidation decomposition of graphite for determination of impurity elements, Bunseki Kagaku, 1986, 35, 911. (Fac. Sci., Shimane Univ., Matsue 690, Japan). Hashitani, H., Yoshida, H., Izawa, K., Adachi, T., Analytical studies on impurity elements in nuclear-grade graphite, Bunseki Kagaku, 1986, 35, 920. (Fac. Sci., Shimane Univ., Matsue 690. Japan). Bol’shov, M. A., Dashin, S. A., Zybin, A. V., Koloshnikov, V. G., Maiorov, I. A., Smirenkina, I. I., Direct determina- tion of trace amounts of cobalt in high-purity tin by laser atomic fluorescence spectrometry with electrothermal atomisation in vacuum, Zh.Anal. Khim., 1986,41, 1862. (State Sci. Res. Des. Inst. Rare Met. Ind., Moscow, USSR). Galinier, C., Bouhlel, S., Reynier, B., Determination of barium and strontium by atomic absorption in aqueous solutions with [Sr] [Ba] ratios ranging from 0.04 to 15000, Analusis, 1986, 14, 466. (Lab. Mineral. Cristallogr., 31062 Toulouse, France). Curtius, A. J., Schlemmer, G., Welz, B., Determination of phosphorus by graphite furnace atomic absorption spec- trometry. Part 1. Determination in the absence of a modifier, J . Anal. At. Spectrom., 1986, 1, 421. (Dept. Appl. Res., Bodenseewerk Perkin-Elmer und Co. GmbH, D-7770 Uberlingen, FRG). Kuroda, R., Nakano, T., Miura, Y., Oguma, K., Determi- nation of trace amounts of nickel and cobalt in silicate rocks by graphite furnace atomic absorption spectrometry: elimination of matrix effects with an ammonium fluoride modifier, J .Anal. At. Spectrom., 1986, 1,429. (Fac. Eng., Univ. Chiba, Chiba, Japan). Branch, C. H., Hutchison, D., Rapid screening method for the determination of platinum and palladium in geological materials by batch ion-exchange chromatography and graphite furnace atomic absorption spectrometry, J. Anal. At. Spectrom., 1986,1,433. (British Geol. Surv., 64 Gray’s Inn Rd., London WClX 8NG, UK). Carnrick, G. R., Lumas, B. K., Barnett, W. B., Analyses of solid samples by graphite furnace atomic absorption spectrometry using Zeeman background correction, J . Anal.At. Spectrom., 1986, 1, 443. (Perkin-Elmer Corp., 901 Ethan Allen Hwy., Ridgefield, CT 06877, USA). Hoenig, M., Dehairs, F., De Kersabiec, A. M., Effects of ageing of pyrolytically coated tubes on the determination of refractory elements by electrothermal atomisation atomic absorption spectrometry, J . A n d . At. Spectrom., 1986, 1, 449. (Inst. Chem. Res., Minist. Agric., 1980 Tervuren, Belgium). Nakahara, T., Wasa, T., Determination of tin by non- dispersive atomic fluorescence spectrometry coupled with a hydride generation technique, J . Anal. At. Spectrom., 1986, 1, 473. (Coll. Eng., Univ. Osaka Prefect., Osaka 591, Japan). Macdonald, L. R., O’Haver, T. C., Ottaway, B. J., Ottaway, J. M., Background atomic absorption in graphite furnace atomic absorption spectrometry, J .Anal. At. Spectrom., 1986, 1, 485. (Dept. Pure Appl. Chem., Univ. Strathclyde, 295 Cathedral St., Glasgow G1 lXL, UK). Hiraide, M., Tschoepel, P., Toelg, G., Separation of trace elements from high-purity metals by simultaneous elec- trolytic dissolution and electrode position of the matrix on a mercury cathode. Part 1. Determination of aluminium in iron by electrothermal atomic absorption spectrometry, Anal. Chim. Acta, 1986, 186,261. (Max-Planck-Inst. Met. Res., D-4600 Dortmund 1, FRG).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 201R 8711558. 8711559. 8711560. 8711561. 871 1562. 8711563. 8711 564. 8711565. 87/1566. 8711567, 87/1568. 8711569. 8711570. 8711571. 8711572. Simeonova, S., Bekjarov, G., Futekov, L., Flame AAS determination of selenium and tellurium in copper concen- trates, Fresenius Z.Anal. Chem., 1986, 325, 478. (Cent. Res. Lab., Plovdiv Univ., BG-4000 Plovdiv, Bulgaria). D’Ulivo, A., Papoff, P., Simultaneous detection of alkyl- selenide, alkyllead and alkyltin compounds by gas chro- matography using a multi-channel non-dispersive atomic fluorescence spectrometric detector and a miniature flame as the atomiser, J . Anal. At. Spectrom., 1986, 1, 479. (1st. Chim. Anal. Strum., Univ. Pisa, 56100 Pisa, Italy). Sandel, B. R., Broadfoot, A. L., Statistical performance of the intensified charged coupled device, Appl. Opt., 1986, 25, 4135. (Univ. Arizona, Lunar and Planetary Lab., Tucson, Arizona 85721, USA). Doering, C. R., Harvey, P. M., Optimal signal-to-noise in digital phase lock amplifiers, Appl.Opt., 1987, 26, 633. (Los Alamos Natl. Lab., Center for Nonlinear Studies, Los Alamos, NM 78712, USA). Burba, P., Willmer, P. G., Determination (AAS, ICP- AES) of aluminium, molybdenum, titanium, uranium and vanadium in natural waters after pre-concentration by means of iron(II1)- or indium(II1)-loaded cellulose, Vom Wasser, 1986, 66, 33. (Inst. Spektrochem., D-4600 Dort- mund 1, FRG). Chappuis, P., Paolaggi, F., Hontchoye, P., Rousselet, F., Clarification on a method for separating cells in whole blood, Clin. Chem., 1986, 32, 2116. (Lab. de Biochim. Appliquie, Fac. Sci. Pharmaceutiques et Biol., 4, avenu6 de l’observatoire, 75006 Paris, France). Julshamn, K., Andersen, K. J., Vik, H., Determination of silver in biological samples using Zeeman graphite furnace atomic absorption spectrometry, Acta Pharmacol.Toxi- col., Suppl., 1986, 59, 613. (Inst. Nutr., Univ. Bergen, Bergen, Norway). Famme, P. B., Riisgaard, H. U., New method for studying mercury accumulation in marine food chains, Dan. Kemi, 1986, 67(&7), 188. (Biol. Inst., Odense Univ., Odense, Denmark). Paschal, D. C., Bailey, G. G., Determination of thallium in urine with Zeeman effect graphite furnace atomic absorp- tion, J. Anal. Toxicof., 1986, 10, 252. (Div. Environ. Health Lab. Sci., Cent. Environ. Health, Atlanta, GA 30333, USA). Wills, M. R., Sunderman, F. W., Savory, J., Methods for the estimation of serum magnesium in clinical labora- tories, Magnesium, 1986, 5 , 317. (Dept. Pathol., Univ. Virginia, Charlottesville, VA 22908, USA).Elin, R. J., Hook, G., Hosseini, J. M., Comparison of two methods for determination of magnesium concentration of mononuclear blood cells, Magnesium, 1986, 5 , 301. (Clin. Pathol. Dept., Natl. Inst. Health, Bethesda, MD 20892, USA). Alvarez, G. H., Capar, S. G., Determination of tin in foods by hydride generation - atomic absorption spec- trometry, Anal. Chem., 1987, 59, 530. (Div. Contam. Chem., Food and Drug Adm., Washington, DC 20204, USA). Martinez-Tarazona, R., Cardin, J. M., The indirect determination of chlorine in coal by atomic absorption spectrophotometry, Fuel, 1986, 65, 1705. (Inst. Nac. Carbon Deriv., CSIC, Oviedo, Spain). Filkova, L., Joger, J., Determination of ultratrace coneen- trations of nickel tetracarbonyl in air, Chem. Listy, 1986, 80, 1207.(Inst. Hyg. Epidemiol.. 100 42 Prague, Czecko- slovakia). Speer, R., Hoffmann, P., Lieser, K. H., Problems in measuring water samples of different salt content by ICP-AES, Fresenius 2. And. Chem., 1986, 325, 558. (Fachbereich Anorg. Chem. Kernchem., Tech. Hochsch. Darmstadt, D-6100 Darmstadt, FRG). 8711.573. 8711574. 8711575. 8711 576. 8711577. 8711578. 871 1579. 8711580. 8711581. 8711 582. 871 871 871 583. 584. 585. 8711 586. 8711587. 8711588. Adachi, A., Kobayashi, T., Determination of total phos- phorus and orthophosphate in water by atomic absorption spectrometry, Eisei Kagaku, 1986,32,39. (Kobe Women’s Coll. Pharm., Kobe 658, Japan). Risby, T. H., Atomic spectrometric analysis, Chem. Anal. ( N . Y . ) , 1986, 85, 179. (Sch. Hyg. Public Health, Johns Hopkins Univ., Baltimore, MD, USA).Smith, J. B., Ahuja, S., Impurity analysis of excipients, Chem. Anal. ( N . Y . ) , 1986, 85, 217. (Pharm. Div., Ciba-Geigy Corp., Suffern, NY, USA). Sanchez de Rojas, M. I., De Luxan, M. P., Frias, M., Inductively coupled plasma emission spectrometry, Muter. Constr. (Madrid), 1986, 36, 31. (CSIC, Spain). Stoeppler, M., Recent methodological progress in cad- mium determination, Int. J. Environ. Anal. Chem., 1986, 27, 231. (Inst. Appl. Phys. Chem., (KFA) Jiilich, D-5170 Jiilich, FRG) . Atnashev, Yu. B., Korepanov, V. E., Muzgin, V. N., Analytical signal distortion in electrothermal atomic absorption spectrometry, Zh. Prikl. Spektrosk., 1986, 45, 737. (USSR). Komori, K., Igarashi, S., Yotsuyanagi, T., A simple and rapid concentration method for trace amounts of nicke- I(II), copper(I1) and cadmium(I1) with a polysaccharide “chitin” and maleonitriledithiolate ion, Bunseki Kagaku, 1986,35, 890.(Dept. Appl. Chem., Tohoku Univ., Sendai 980, Japan). Liao, Z., Jiang, Z., Chen, H., Chemical pre-concentration and ICP-AES (inductively coupled plasma atomic emis- sion spectrometry) determination of trace amounts of non-rare earth metals in high-purity yttrium oxide, Xiyou Jinshu, 1986, 5 , 219. (Dept. Chem., Wuhan Univ., Wuhan, China). Musaick, K., Jackwerth, E., The interference of the AAS determination of traces of platinum by copper and and by other heavy metal ions, Fresenius 2. Anal. Chem., 1986, 325, 175. (Fak. Chem., Ruhr-Univ. Bochum, D-4630 Bochum 1, FRG). Matsusaki, K., Yoshino, T., Removal of chloride interfer- ence in the determination of thallium by AAS with a graphite furnace, Bunseki Kagaku, 1986, 35, 931.(Tech. Coll., Yamaguchi Univ., Ube 755, Japan). Ise, K., Flame photometric determination of rhenium in molybdenum refinery dust, Bunseki Kagaku, 1986, 35, T107. (Natl. Res. Inst. Pollut. Resourc., Yatabe 305, Japan). Nakamura, S., Kubota, M., Effect of anions and acids on signal absorbance in electrothermal atomic absorption spectrometry, Bunseki Kagaku, 1986, 35, 844. (Natl. Chem. Lab. Ind., Yatabe 305, Japan). Etoh, M., Irokawa, H., Determination of platinum metals in catalysts by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using an internal standard, Bun- seki Kagaku, 1986, 35, 849. (Ichikawa Lab., Nippon Engelhard Ltd., Ichikawa 272, Japan).Scherer, V., Hirschfeld, D., Determination of trace-ele- ment contents in tungsten metal using atomic spectrome- tric methods, Erzmetall, 1986, 39, 251. (Osram GmbH, D-8000 Munich, FRG). Matusiewicz, H., Determination of dissolved alkali and alkaline earth elements in rock salt and brine by atomic emission spectrometry with a nitrous oxide - ace‘ylene flame, Spectroscopy (Springfield, Oreg.), 1986, 1 (12), 32. (Dept. Anal. Chem., Tech. Univ. Poznan, 60-965 Poznan, Poland). Katz, S. A., Salem, H., Comparison of spectrophotometric methods for the determination of hexavalent chromium in whetlerite, Spectroscopy (Springfield, O r e g . ) , 1986,1(12), 35. (Rutgers, State Univ., Camden, NJ 08102, USA).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 202R 87/1589. 87/1590. 87/1591. 8711592. 87/1593. Chen, Y., Hu, Z., Jia, X., Atomic absorption spectro- metric determination of trace arsenic in MOS grade hydro- chloric acid after extraction with ammonium di-sec-butyl- dithiophosphate, Huaxue Shiji, 1986, 8, 310. (Dept. Chem., East China Norm. Univ., Shanghai, China). Ebdon, L., Lechotycki, A., The determination of lead in environmental samples by slurry atomisation graphite furnace atomic absorption spectrophotometry using mat- rix modification, Microchem. I., 1986, 34, 340. (Dept. Environ. Sci., Plymouth Polytech., Plymouth, Devon PL4 8AA, UK). Bullock, D. G., Smith, N. J., Whitehead, T. P., External quality assessment of assays of lead in blood, Clin. Chem., 1986, 32, 1884.(Wolfson Research Laboratories, Queen Elizabeth Medical Centre, Birmingham B15 2TH, UK). Speich, M., Chappuis, P., Robinet, N., Gelot, S., Arnaud, P., Nguyen, V. G., Nicolas, G., Rousselet, F., Se, Zn, Mg, Ca, K, cholesterol and creatine kinase concentrations in men during the 12 days after an acute myocardial infarction, Clin. Chem., 1987, 33, 21. (Lab. Biochim. Pharm. Fac. Pharm., 1 Rue Gaston Veil, 44035 Nantes Cedex, France). Bourdon, S., Houze, P., Bourdon, R., Quantification of desferrioxamine in blood plasma by inductively coupled plasma atomic emission spectrometry, Clin. Chem., 1987, 33, 132. (Dept. Anal. Chem., Rene Descartes Univ., Paris, France). Papers 87/C1594871C1686 were presented at the 1987 Pittsburgh Conference and Exposition on Analytical Chemistry and Applied Spectroscopy, Atlantic City, NJ, USA, 9th-13th March, 1987.87/C1594. Roehl, R., Indirect detection of halogens by ICP-AES in the UV - visible, (California Public Health Foundation, 2151 Berkeley Way, Berkeley, CA 94704, USA). 871C1595. Wolnik, K. A., Gaston, C. M., Fricke, F. L., Analysis of glass in tampering incidents by ICP-OES, (Elemental Analysis Research Centre, US Food and Drug Adminis- tration, 1141 Central Parkway, Cincinnati, OH 45202, USA). 87/C1596. Wirsz, D. F., Blades, M. W., Jones, S., Qualitative and quantitative analysis using an inductively coupled plasma photodiode array spectrometer-single line versus multi- line detection, (Dept. Chem., Univ. British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Y6, Canada). 87/C1597. Houk, R.S., Lim, H. B., Lafreniere, B. R., Fassel, V. A,, Spectral characteristics of a discharge extracted from an inductively coupled plasma, (Ames Laboratory-US DOE and Dept. Chem., Iowa State Univ., Ames, IA 50011, USA). 871C1598. Burton, L. L., Heisz, G. G., Blades, M. W., Computer simulation of spectral interferences in ICP-OES, a promis- ing application of ICP fundamental studies, (Dept. Chem., Univ. British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Y6, Canada). 871C1599. Gallimore, D., Bentley, G. E., Wangen, L., Peterson, E. J., Parsons, M. L., Quintana, M., The use of factor analysis to study elemental covariance in the inductively coupled plasma, (Los Alamos Natl. Lab., CLS-1, MS G740, Los Alamos, NM 87545, USA). 87/C1600. Babis, J. S., Kinsey, W. J., An improved direct current plasma source, (Applied Research Laboratories, 3080 Enterprise Ave., Brea, CA 92621, USA).87/C1601. Lovell, A. P., Del Mar, P., Bentley, G. E., Determination of impurities in plutonium by direct current plasma emission spectroscopy, (Los Alamos Natl. Lab., CLS-1, MS G740, Los Alamos, NM 87545, USA). 87/C1602. Bernhard, A. E., Scuitto, Thomas J., Scuitto, Theodore J., Mickle, T. E., Piepmeier, E. H., Kim, H. J., High precision, large dynamic range atomic absorption analysis system using direct solids sputtering atomisation, (Analyte Corporation, 611 Southeast L St., Grants Pass, OR 97526, USA). 87/C1603. Buckley, B. T., Boss, C. B., Gentry, J. S., Modulated DCP: a tool for determination of plasma excitation mechanisms, (Dept. Chem., North Carolina State Univ., Box 8204 Raleigh, NC 27695-8204, USA).87/C1604. Katz, S. A., Strohben, W. E., Toxic elements in coloured gift wrap paper, (Dept. Chem., Rutgers Univ., Camden, NJ 08102, USA). 87/C1605. Kim, H. J., Piepmeier, E. H., Bernhard, A. E., Fundamen- tal studies of a high efficiency sputtering system for atomic spectroscopy, (Dept. Chem., Oregon State Univ., Corval- lis, OR 97331, USA). 87/C1606. Morselli, L., Carrelli, R., Errani, E., Gallorini, M., Rizzio, E., Heavy metals determinations in dry and wet meteoric deposition, (1st. Tech. Chimiche Speciali, V. le Risorgimento No. 4,40136 Bologna, Italy). 871C1607. Bolton, J. S., Long, G. L., Diagnostic studies of refractory slurries in the ICP, (Dept. Chem., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061, USA).87/C1608. Moore, J., Frary, B., Brodie, K., Shrader, D. E., An intelligent use of graphite furnace features to simplify the analysis of samples with complex matrices, (Varian Tech- tron Pty Ltd., 679 Springvale Rd., Mulgrave, Victoria 3 170, Australia). 87/C1609. Golloch, A., Brockmann, A., KUSS, H.-M., Simultaneous multi-element atomic absorption spectrometry by mean of a fibre optic, (Univ. Duisburg, Postfach 101629, D 4100 Duisburg, FRG). 87/C1610. Haswell, S. J., The development of slurry methods in atomic absorption spectrometry, (Sch. Chem., Thames Polytech., Wellington St., London SE18 6PF, UK). 87/C1611. Vollkopf, U., Baasner, J., Grobenski, Z., Elimination of drift in AAS, (Bodenseewerk Perkin-Elmer & Co. GmbH, PO Box 1120, D-7770 Uberlingen, FRG).87/C1612. Bradley, H. E., Fibre optics modularises ICP spec- trometer, (Spectro Inc., 160 Authority Drive, Fitchburg, MA 01420, USA). 871C1613. Horlick, G., Lepla, K., Measurement characteristics and capabilities of a new PDA linear image sensor for ICP-AES, (Dept. Chem., Univ. Alberta, Edmonton, Alberta T6G 2G2, Canada). 871C1614. DeVries, J., Lazure, R. E., Phillips, R. W., McGeorge, S. W ., Data processing techniques for multi-element ICP spectra produced using the Plasmarray spectrometer system, (PRA International Inc., 45 Meg Drive, London, Ontario N6E 2V2, Canada). 87/C1615. Horlick, G., Todd, B., King, G., A Fourier transform spectrometer system for ICP-AES, (Dept. Chem., Univ. Alberta, Edmonton, Alberta T6G 2G2, Canada). 87lC1616.Smith, S. B., Jr., Brown, R. M., Schleicher, R. G., Sainz, M. A,, Chemometrics and the commercial instrument: resolution of spectral interferences by computation, (Thermo Jarrell-Ash, 590 Lincoln St., Waltham, MA 02254, USA). 87/C1617. Blades, M. W., Burton, L. L., Caughlin, B. L., Walker, Z., Excitation in the inductively coupled plasma- evidence for a partial-LTE model, (Dept. Chem., Univ. British Columbia, 2036 Main Mall, Vancouver, BC V6T 1Y6, Canada). 87/C1618. Nygaard, D. D., Stux, R. L., Sotera, J. J., Background 87/C 871C correction on a polychromator ICP using a new software package, (Thermo Jarrell-Ash, 590 Lincoln St., Waltham, MA 02254, USA). 619. McGeorge, S. W., Moak, H. W., Falconer, J. B., Method development strategies for a flexible simultaneous multi- element spectrometer system based on photodiode array detection, (PRA International Inc., 45 Meg Drive, Lon- don, Ontario N6E 2V2, Canada).620. Olesik, J. W., Bradley, K. R., Williamsen, E., Den, S.-J., Excitation and relaxation processes in the inductively coupled plasma studied by power modulation, (Dept. Chem., Venable and Kenan Lab. 045A, Univ. North Carolina, Chapel Hill, NC 27514, USA).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 203R 87lC1621. 87lC1622. 871C1623. 87lC1624. 871C1625. 87/C1626. 871C1627. 871C1628. 871C1629. 871C1630. 87lC1631. 87lC1632. 87lC1633. 87lC1634. 871C1635. 87lC1636. Genna, J. L., Petit, J. M., The direct analysis of aluminium and alumina by spark nebulisation - ICP emission spectro- scopy, (Aluminium Co.of America, Alcoa Technical Center, Alcoa Center, PA 15069, USA). Pivonka, D. E., King, E. E., Fry, R. C., Sample pair modulation studies of organic molecular fragmentation in high powered microwave and inductively coupled plasmas, (Dept. Chem. , Willard Hall, Manhattan, KS 66506, USA). Yamamoto, Y., Yamamoto, M., Yasuda, M., Hydride generation atomic absorption spectrometry coupled with flow injection analysis for lead and tin, (Fukui Inst. Technol., Gakuen, Fukui 910, Japan). McCurdy, D. L., Fietkau, R., Clark, R. E., Wichman, M. D., Fry, R. C., Slurry atomisation ICP and DCP emission direct analysis of everything from solid biological tissues to refractory inorganic materials, (Dept. Chem., Willard Hall, Kansas State Univ., Manhattan, KS 66506, USA). Bradley, K.R., Olesik, J. W., Spatially and temporally resolved measurement of electron number densities in an ICP using a two-dimensional detector, (Dept. Chem., Venable and Kenan Lab. 045A, Univ. North Carolina, Chapel Hill, NC 27514, USA). Tikkanen, M. W., Goulter, J. E., Performance assessment of continuous flow hydride generation coupled to a low flow, low power sequential ICP spectrometer, (Applied Research Laboratories, Inc., 9545 Wentworth St., PO Box 129, Sunland, CA 91040, USA). Den, S.-J., Olesik, J. W., Supercritical fluid sample introduction for ICP spectrometry, (Dept. Chem. , Ven- able and Kenan Lab. 045A, Univ. North Carolina, Chapel Hill, NC 27514, USA). Genna, J. L., Predebon, R. E., Ruschak, M. L., Strobel, J. J., A generalised analytical method using microwave oven dissolution and ICP atomic emission spectroscopy, (Alu- minum Co.of America, Alcoa Technical Center, Alcoa Center, PA 15069, USA). Hurwitz, J. K., Pealstrom, K. C., A flexible computer program for d.c. plasma and optical emission spectro- metric analysis, (109 Leslie Rd., Monroeville, PA 15146, USA). McCreary, T. W., Yoon, R.-H., Long, G. L., Effect of organic gases on emission signals from slurries in the DCP, (Dept. Chem., Virginia Polytech. Inst. and State Univ., Blacksburg, VA 24061, USA). Monnig, C. A., Marshall, K. A., Gebhart, B. D., Hieftje, G. M., Three-dimensional imaging of spectroscopic sources by tomographic reconstruction, (Dept. Chem., Indiana Univ., Bloomington, IN 47405-4001, USA), Karanassios, V., Horlick, G., The instrument metaphor concept and its application to ICP-AES instrumentation, (Dept.Chem., Univ. Alberta, Edmonton, Alberta T6G 2G2, Canada). Marshall, K. A., Hieftje, G. M., The use of Thomson and Rayleigh scattering for simultaneous measurement of kinetic and electron temperatures in analytical plasmas, (Dept. Chem., Indiana Univ., Bloomington, IN 47405- 4001, USA). Tatro, M. E., Direct STPF AAS analyses of serum aluminium using aqueous standards, (SPECTRA, At. Spectrosc. and Chromatogr. Specialists, PO Box 352, Pomtpon Lakes, NJ 07422, USA). Urasa, I. T., Ferede, F., The use of d.c. plasma as element selective detector for ion chromatographic determination of trace element species, (Dept. Chem., Hampton Univ., Hampton, VA 23668, USA). Vien, S. H., Page, R., Fry, R. C., Interference mechanisms and masking techniques for the analytical hydride pre- concentration (arsenic, selenium, etc.), (Dept. Chem., Willard Hall, Kansas State Univ., Manhattan, KS 66506, USA).87/C1637. 87lC1638. 871C1639. 871C1640. 871C1641. 87lC1642. 871C1643. 871C1644. 871C1645. 871C1646. 87lC1647. 87/C 1648. 87/C1649. 87/C1650. 87lC1651. 87lC1652. 87K1653. Supp, G. R., The analysis of zinc and bismuth in organic accelerators for natural and synthetic rubbers by atomic absorption spectrometry, (R. T. Vanderbilt Co., E. Norwalk, CT 06855, USA). Hassett, D. J., Hassett, D. F., An extraction procedure for the determination of trace levels of molybdenum by atomic absorption, (Univ. North Dakota, Engineering Experi- ment Station, Box 8103, Grand Forks, ND 58202, USA).Kane, J. S., Dorrzapf, A. F., Jr., Application of SIMAAC analysis to specific geochemical problems, (US Geol. Surv. Mail Stop 923, Reston, VA 22092, USA). Droessler, M. S., Holcombe, J. A., The vaporisation of selenium and nickel following solution deposition on a graphite surface, (Dept. Chem., Univ. Texas at Austin, Austin, TX 78712, USA). Fietkau, R., Venkatesan, P., Clark, R. E., Fry, R. C., Slurry atomisation flame and graphite furnace atomic absorption direct analysis of whole, solid tissue samples, (Dept. Chem., Willard Hall, Kansas State Univ., Manhat- tan, KS 66506, USA). Ueda, J., Miyanaga, K., Rains, T. C., Flameless atomic absorption spectrometric determination of tin after copre- cipitation with hafnium hyroxide, (Fac. Education, Kana- zawa Univ., Marunouchi, Kanazawa 920, Japan).Stec, R. J., Koirtyohann, S. R., Taylor, H. E., Reverse osmosis pre-concentrator for graphite furnace atomic absorption spectroscopy, (Dept. Chem., Univ. Missouri, Columbia, MO 65211, USA). Miyama, T., Fukui, I., In-depth analysis of surface treated steel sheets by glow discharge lamp emission spec- trometry, (Shimadzu Corp., 1 Nishinokyo-Kuwabaracho, Nakagyo-ku, Kyoto 604, Japan). Carnrick, G. R., Giddings, R. C., Slavin, W., Barnett, W. B., Determination of barium using graphite furnace atomic absorption, (Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT 06859-0906, USA). Voth-Beach, L. M., Graphite furnace AA: reduced interferences with palladium - H2 matrix modification, (Varian Instrument Group, AA Resource Center, 205 W.Touhy Ave., Park Ridge, IL 60068, USA). Aryamanya-Mugisha, H., Green, R. B., Williams, R., The microarc as an excitation source for atomic emission spectroscopy, (Dept. Chem., Ohio Univ., Athens, OH 45701, USA). Rettberg, T. M., Holcombe, J. A., Direct solids analysis by GFA: metallurgical samples, (Dept. Chem., Univ. Texas at Austin, Austin, TX 78712, USA). Tatro, M. E., Development of flame AAS and ICP methods for the analyses of Al, Na and Si in zeolites, (SPECTRA, At. Spectrosc. and Chromatogr. Specialists, PO Box 352, Pompton Lakes, NJ 07442, USA). Klunder, G. L., Boss, C. B., Study of cobalt(II1) com- plexes using uniform isolated droplet introduction in flame AAS, (Dept. Chem., North Carolina State Univ., Box 8204, Raleigh, NC 27695-8204, USA). Anderson, D.G., Weiss, A. D., Boss, C. B., Optimisation of tandem flame spectrometry for the analysis of metals, (Dept. Chem., North Carolina State Univ., Box 8204, Raleigh, NC 27695-8204, USA). Routh, M. W., Athanasopoulos, N., Chapple, G. E., Liddell, P. R., The application of a new furnace atomic absorption system to environmental analysis, (Applied Research Laboratories Inc., 9545 Wentworth St., Sun- land, CA 91040, USA). Attiyat, A. S., Effect of non-aqueous solvents on chemical analysis by atomic absorption spectrophotometry , (Chem. Dept., Yarmouk Univ., Irbid, Jordan).204R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 87/C1654. Slavin, W., Carnrick, G. R., Manning, D. C., Characteris- tic mass values for graphite furnace AAS, (Perkin-Elmer Corp., 901 Ethan Allen Hwy., Ridgefield, CT 06877, USA).87/C1655. McNally, J., Holcombe, J. A., Vaporisation mechanisms from metal microdroplets and electrothermal atomisers, (Dept. Chem., Univ. Texas at Austin, Austin, TX 78712, USA). 87/C1656. Adnan, A., Gilbert, T. R., Hildebrand, K. J., Evaluation of a dual grid nebuliser for spectrochemical analysis with the inductively coupled plasma, (Dept. Chem., North- eastern Univ., Boston, MA 02115, USA). 87/C1657. Dulude, G. R., Pfeil, D. L., Sotera, J. J., A critical look at the method of standard additions in furnace AAS, (Thermo Jarrell-Ash, 590 Lincoln St., Waltham, MA 02254, USA). 87/C1658. Vollkopf, U., Baasner, J., Grobenski, Z., Water analysis by automated AAS, (Bodenseewerk Perkin-Elmer & Co. GmbH, PO Box 1120, D-7770 Uberlingen, FRG).87/C1659. Ward, G. K., The evolution of ICP AA technology and analytical methodologies for inorganic analysis of environ- mental samples, (US Environ. Protection Agency Office of Emergency and Remedial Response (WH-548A), 401 M St., SW, Washington, DC 20460, USA). 87/C1660. Gallimore, D., Bentley, G. E., Wangen, L., Quintana, M., Salit, M. L., Evaluation of a multi-element simplex procedure for a large (up to 42 elements) ICP-AES system, (Los Alamos Natl. Lab., CLS-1, MS G740, Los Alamos, NM 87545, USA). 87/C1661. Kinsey, W. J., Oelke, B. D., A comparison of AA, DCP-AES and ICP-AES for the analysis of water and waste, (Applied Research Laboratories Inc., Brea, CA 87/C1662. Mann, D. L., Analysis of boron in contaminated shrimp by inductively coupled argon plasma spectrophotometry, (McCrone Environ.Services Inc., 200 Oakbrook Business Center, 5500 Oakbrook Parkway, Norcross, GA 30093, USA). 87/C1663. Condit, D. A,, Smeggil, J. G., Ward, I. W., Huneke, J. C., The determination of indigenous sulphur in nickel-based superalloys by glow disharge mass spectrometry, (United Technologies Res. Center, Mail Stop 94, East Hartford, CT 06108, USA). 87/C1664. Satzger, R. D., Fricke, F. L., Caruso, J. A., A comparison of microwave induced and inductively coupled plasma sources for elemental mass spectrometric determinations, (Elemental Anal. Res. Center, Food and Drug Adminis- tration, 1141 Central Parkway, Cincinnati, OH 45202, USA). 87/C1665. Vickers, G. H., Wilson, D. A., Hieftje, G.M., Pressure and temperature effects in inductively coupled plasma mass spectrometry, (Dept.Chem., Indiana Univ., Blooming- ton, IN 47405-4001, USA). 87K1666. Vickers, G. H., Wilson, D. A., Hieftje, G. M., Alternative ion sources for plasma source mass spectrometry, (Dept. Chem., Indiana Univ., Bloomington, IN 47405-4001, USA). 87/C1667. Houk, R. S., Jiang, S.-J., Rowan, J. T., Instrumental improvements in inductively coupled plasma mass spec- trometry, (Ames Lab.-USDOE and Dept. Chem., Iowa State Univ., Ames, IA 50011, USA). 87/C1668. Anderau, C., Pruszkowski, E., Yates, D. A., Performance of a molded high-solids nebuliser, (Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT 0659-0906, USA). 87/C1669. Brown, P. G., Caruso, J. A,, Satzger, R. D., Fricke, F. L., Helium microwave induced plasma mass spectrometry for the positive ion analysis of non-metals, (Dept.Chem., Univ. Cincinnati, Cincinnati, OH 45221, USA). 87/C1670. Ethier, R. L., An automated apparatus for the rapid sodium peroxide fusion of metallurgical samples for ICP-AES analysis, (Inco Ltd., Central Process Technol- ogy, Copper Cliff, Ontario POM 1N0, Canada). 92621-6209, USA). 87/C1671. Fredeen, K. J., Pruszkowski, E., Yates, D. A., Using the ICP for analysis of semiconductor processing chemicals, (Perkin-Elmer Corp., 761 Main Ave., Norwalk, CT 871C1672. Hitch, G. L., Hackman, J. R., Wichman, M. D., Determi- nation of trace lead in calcined inorganic pigments by DCP emission spectroscopy, (The Shepherd Color Company, 4585 Dues Drive, Cincinnati, OH 45246, USA). 87/C1673. Demers, D.R., Improved detection limits in ICP atomic fluorescence spectrometry using a high efficiency pneu- matic nebuliser and aerosol desolvation, (Baird Corp., 125 Middlesex Turnpike, Bedford, MA 01730, USA). 87/C1674. Williamsen, E. J., Olesik, J. W., Fundamental and applied studies of matrix effects and precision in ICP spec- trometry, (Dept. Chem., Venable and Kenan Lab. 045A, Univ. North Carolina, Chapel Hill, NC 27514, USA). 87/C1675. Houk, R. S., Inductively coupled plasma mass spec- trometry: an overview, (Ames Lab.-USDOE and Dept. Chem., Iowa State Univ., Ames, IA 50011, USA). 87/C1676. Gray, A. L., Origins, principles and performance of ICP-MS, (Dept. Chem., Univ. Surrey, Guildford, Surrey GU2 5XH, UK). 87/C1677. Horlick, G., Tan, S. H., Vaughan, M. A., Lam, J., Matrix effects and interferences in inductively coupled plasma mass spectrometry, (Dept.Chem., Univ. Alberta, Edmonton, Alberta T6G 2G2, Canada). 87/C1678. McLaren, J. W., Beauchemin, D., Berman, S. S., ICP-MS analysis of marine reference materials, (Anal. Chem. Section, Chem. Div., Natl. Res. Council of Canada, Ottawa K1A OR9, Canada). 87/C1679. Meddings, B., Ng, R., Some practical applications of an ICP-MS instrument, (Sherritt Gordon Mines Ltd., Research Centre, Fort Saskatchewan, Alberta T8L 2P2, Canada). 87/C1680. Condit, D. A., Gerstung, C. H., Cowher, M. E., Shuskus, A. J., Direct gas analysis of transportable metal organic contaminants by ICP-AES, (United Technologies Res. Cent., E. Hartford, CT 06108, USA). 87/C1681. Vozzella, P. A., The determination of yttrium in complex alloys using microwave dissolution and ICP-AES, (United Technologies Res.Cent., E. Hartford, CT 06108, USA). 87/C1682. Soman, R., Gilbert, T. R., A miniature electrothermal 06859-0906, USA). 87/C 87/C vaporisation cell featuring a NbC-coated heating element for plasma emission spectroscopy, (Dept. Chem., North- eastern Univ., Boston, MA 02115, USA). 683. Gilbert, T. R., Sandoval, J. E., Evaluation of the ashing rotrode as an excitation source of the spectroscopic determination of trace elements in oils, (Dept. Chem., Northeastern Univ., Boston, MA 02115, USA). 684. Hieftje, G. M., Bright, F. V., Galante, L. J., Pearce, M. J., Rezaaiyaan, R., Selby, M., A surfatron for all seasons, (Dept. Chem., Indiana Univ., Bloomington, IN 47405, USA).87/C1685. Luffer, D. R., David, P. A., Selby, M., Galante, L. J., Hieftje, G. M., Novotny, M., Surface-wave-sustained microwave-induced plasma as a detector for capillary supercritical fluid chromatography, (Dept. Chem., Indiana Univ., Bloomington, IN 47405, USA). 87/C1686. Montaser, A., Chan, S.-K., Koppenaal, D. W., An 871 871 atmospheric pressure helium inductively coupled plasma as an ion source for mass spectrometry, (Dept. Chem., George Washington Univ., Washington, DC 20052, USA). Zorn, H., Stiefel, Th., Porcher, H., Clinical and analytical follow up of 25 persons exposed accidentally to beryllium, Toxicol. Environ. Chem., 1986, 12, 163. (Univ. Stuttgart, Stuttgart, FRG). Lepsi, P., Horakova, L., Maskova, H., Determination of zinc in plasma, serum and urine by atomic absorption spectrophotometry, Prac.Lek., 1986,38,355. (Inst. Hyg. Epidemiol., Prague, Czechoslovakia). 687. 688.JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, 8711689. 8711690. 8711691. 8711692. 8711693. 8711694. 8711695. 8711696. 8711697. 8711698. 8711699. 8711700. 8711701. Van Schoor, O., Claes, I., Deelstra, H., Chromium content of European wines, Belg. J. Food Chern. Biotechnol., 1986,41,59. (Dept. Farm. Sci., Univ. Antwerp, Antwerp, Belgium). Kotani, T., Determination of lead in straw, chaff and upolished rice by graphite cup furnace AAS with addition of phosphoric acid as a matrix modifier, Bunseki Kagaku, 1986, 35, 880. (Tsuruoka Tech. Coll., Tsuruoka 997, Japan). De Ruig, W. G., Atomic absorption spectrometric deter- mination of calcium, copper, iron, magnesium, man- ganese, potassium, sodium and zinc in animal feeding stuffs: interlaboratory collaborative studies, J. Assoc.Off. Anal. Chem., 1986, 69, 1009. (State Inst. Qual. Control Agric. Prod., Wageningen, The Netherlands). Seong Lee, B., Yoshimura, E., Tanaka, Y., Saitoh, J . , Yamazaki, S., Toda, S., Combination of wet charring and dry ashing suitable for the determination of trace metals in oily foodstuffs by graphite furnace AAS, Bunseki Kagaku, 1986,35, T120. (Dept. Agric. Chem., Univ. Tokyo, Tokyo 113, Japan). Uden, P. C., Slatkavitz, K. J., Barnes, R. M., Deming, R. L., Empirical and molecular formula determination by gas chromatography - microwave-induced plasma atomic emission spectrometry, Anal. Chim. Acta, 1986, 180, 401.(Dept. Chem., Univ. Massachusetts, Amherst, MA 01003, USA). Sweileh, J. A., Lucyk, D., Kratochvil, B., Cantwell, F. F., Specificity of the ion exchange - atomic absorption method for free copper(I1) species determination in natural waters, Anal. Chem., 1987,59, 586. (Dept. Chem., Univ. Alberta, Edmonton, Alberta T6G 2G2, Canada). Verlinden, J., Gijbels, R., Adams, F., Applications of spark-source mass spectrometry in the analysis of semicon- ductor materials. A review, J. Anal. At. Spectrorn., 1986, 1, 411. (Dept. Chem., Univ. Antwerp (UIA), B-2610 Wilrij k , Belgium). Simonsen, K. W., Nielsen, B., Jensen, A., Andersen, J. R., Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spec- trometry, J. Anal. At.Spectrom., 1986, 1, 453. (Dept. Chem. AD, Royal Danish Sch. Pharm., 2 Universitetspar- ken, DK-2100 Copenhagen, Denmark). Capitan, F., “Gazquez, D., Sanchez, M., Capitan-Vallvey, L. F., Determination of iron by atomic absorption spectrometry after synergistic extraction of the iron(II1) - 5,5‘-methylenedisalicylohydroxamate - tributyl phosphate complex, J. Anal. At. Spectrom., 1986, 1, 457. (Dept. Anal. Chem., Fac. Sci., Univ. Granada, Granada, Spain). Potts, P. J., Webb, P. C., Watson, J. S., Silicate rock analysis by energy-dispersive X-ray fluorescence using a cobalt anode X-ray tube. Part I. Optimisation of excitation conditions for chromium, vanadium, barium and the major elements, J. Anal. At. Spectrorn., 1986, 1, 467. (Dept. Earth Sci., Open Univ. , Walton Hall, Milton Keynes, Bedfordshire MK7 6AA, UK).Gray, A. L., Houk, R. S., Williams, J. G., Langmuir probe potential measurements in the plasma and their correla- tion with mass spectral characteristics in inductively coupled plasma mass spectrometry, J. Anal. At. Spec- trorn., 1987, 2, 13. (Dept. Chem., Univ. Surrey, Guild- ford, Surrey GU2 5XH, UK). Webb, B. D., Denton, M. B., Effect of torch size on a 148-MHz inductively coupled plasma, J. Anal. At. Spec- trorn., 1987,2,21. (Dept. Chem., Fac. Natural Sci., Univ. Arizona, Tucson, A 2 84721, USA). Davies, J., Snook, R. D., Studies of a low-noise laminar flow torch for inductively coupled plasma atomic emission spectrometry. Part 2. Noise power studies and interference effects, J . Anal. At. Spectrorn., 1987, 2, 27.(Trace Analysis Lab., Dept. Chem., Imperial College of Sci. and Technol., London SW7 2AY, UK). 8711 702. 8711703. 8711 704. 8711705. 8711706. 8711707. 8711708. 87/1709. 87/17 10. 871171 1. 87/1712. 8711713. 8711714. VOL. 2 205R Ramsey, M. H., Thompson, M., Walton, S. J., Self-matrix effects as a cause of calibration curvature in inductively coupled plasma atomic emission spectrometry, J. Anal. At. Spectrom., 1987,2,33. (Appl. Geochem. Res. Group, Dept. Geol., Imperial College of Sci. and Technol., London SW7 2BP, UK). Ebdon, L., Wilkinson, J. R., Direct atomic spectrometric analysis by slurry atomisation. Part 1. Optimisation of whole coal analysis by inductively coupled plasma atomic emission spectrometry, J . Anal. At. Spectrom., 1987,2,39. (Dept. Environ.Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Voth-Beach, L. M., Shrader, D. E., Investigations of a reduced palladium chemical modifier for graphite furnace atomic absorption spectrometry, J . Anal. At. Spectrorn., 1987, 2, 45. (Varian Instrument Group, AA Resource Center, 205 W. Touhy Ave., Park Ridge, IL 60068, USA). Torsi, G., Palmisano, F., Spray deposition versus single- drop deposition for calibration of an electrostatic accumu- lation furnace for electrothermal atomisation atomic absorption spectrometry, J . Anal. At. Spectrom., 1987, 2, 51. (Via G. Amendola, 173-70126 Bari, Italy). Aznarez, J., Vidal, J. C., Carnicer, R., Atomic absorption spectrometric determination of lead in gasolines by gener- ation of its covalent hydride, J.Anal. At. Spectrom., 1987, 2, 55. (Dept. Anal. Chem., Fac. Sci., Univ. Zaragoza, Zaragoza, Spain). Demers, Y., Gagne, J.-M., Pianarosa, P., Population distribution of atomic uranium in the afterglow of a pulsed hollow-cathode discharge, J . Anal. At. Spectrom., 1987,2, 59. (Lab. Optique et de Spectrosc., Dept. Genie Physique, Ecole Polytech., Case Postale 6079, Succursale “A”, Montreal H3C 3A7, Canada). Dittrich, K., Stark, H.-J., Laser-excited atomic fluores- cence spectrometry as a practical analytical method. Part 2. Evaluation of a graphite tube atomiser for the determi- nation of trace amounts of indium, gallium, aluminium, vanadium and iridium by LAFS, J . Anal. At. Spectrorn., 1987, 2, 63. (Sektion Chem., Karl-Marx-Univ., WB Analytik, Talstr. 35 DDR-7010, Leipzig, GDR).Potts, P. J., Webb, P. C., Watson, J. S., Wright, D. W., Silicate rock analysis by energy-dispersive X-ray fluores- cence using a cobalt anode X-ray tube. Part 2. Practical application and routine performance in the determination of chromium, vanadium and barium, J . Anal. At. Spec- trom., 1987,2,67. (Dept. Earth Sci., Open Univ., Walton Hall, Milton Keynes, Buckinghamshire MK7 6AA, UK). Borowski, K. J., Tham, F. S., Preiss, I. L., KPIKa intensity ratios for rare earth compounds using radioiso- tope induced X-ray fluorescence, J. Anal. At. Spectrorn., 1987, 2, 73. (Dept. Chem., Rensselaer Polytech. Inst., Troy, NY 12180, USA). Belarra, M. A., Anzano, J. M., Gallarta, F., Castillo, J. R., Determination of metals in poly(viny1 chloride) by atomic absorption spectrometry.Part 2. Determination of lead and magnesium in samples of poly(viny1 chloride) with a high content of alkaline earths, J. Anal. At. Spectrorn., 1987, 2, 77. (Dept. Anal. Chem., Sci. Fac., Univ. Zaragoza, Zaragoza, Spain). Gray, A. L., Williams, J. G., Oxide and doubly charged ion response of a commercial inductively coupled plasma mass spectrometry instrument, J. Anal. At. Spectrorn., 1987, 2, 81. (Dept. Chem., Univ. Surrey, Guildford, Surrey GU2 5XH, UK). Ebdon, L., Cresser, M. S., McLeod, C. W., Atomic Spectrometry Update-environmental analysis, J. Anal. At. Spectrorn., 1987, 2, 1R. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). de Galan, L., A physicist’s view on current questions in atomic spectrometry, J .Anal. At. Spectrom. , 1987, 2, 89. (Lab. voor Anal. Chem.,TechnischeUniv. Delft, deVries van Heystplantsoen 2, 2628 RZ Delft, The Netherlands).206R 8711715. 87/1716. 8711717. 87/17 18. 871 171 9. 8711720. 8711721. 8711722. 8711723. 8711724. 8711725. 8711726. JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 L’vov, B. V., Recent advances in the theory of atomisation in graphite furnace atomic absorption spectrometry: the oxygen - carbon alternative, J. Anal. At. Spectrom. , 1987, 2 , 95. (Dept. Anal. Chem., Polytech. Inst., Leningrad 195251, USSR). Harnly, J. M., Holcombe, J. A., Mathematical correction of systematic temporal background-correction errors for graphite furnace atomic absorption spectrometry, J. Anal. At. Spectrom., 1987, 2, 105.(US Dept. Agric., ARS Beltsville Human Nutrition Res. Cent. , Nutrient Compo- sition Lab., Beltsville, MD 20705, USA). Curtius, A. J., Schlemmer, G., Welz, B., Determination of phosphorus by graphite furnace atomic absorption spec- trometry. Part 2. Comparison of different modifiers, J. Anal. At. Spectrom., 1987, 2, 115. (Dept. Appl. Res., Bodenseewerk Perkin-Elmer & Co. GmbH, D-7770 Uberlingen, FRG). Karwowska, R., Jackson, K. W., Atomisation characteris- tics of lead determined in alumina matrices by slurry - electrothermal atomisation atomic absorption spec- trometry, J. Anal. At. Spectrom., 1987, 2, 125. (Dept. Chem., Univ. Saskatchewan, Saskatoon, Saskatchewan S7N OWO, Canada). Ebdon, L., Parry, H. G. M., Direct atomic spectrometric analysis by slurry atomisation.Part 2. Elimination of interferences in the determination of arsenic in whole coal by electrothermal atomisation atomic absorption spec- trometry, J. Anal. At. Spectrom., 1987, 2, 131. (Dept. Environ. Sci. , Plymouth Polytech. , Drake Circus, Ply- mouth, Devon PL4 8AA, UK). Tsalev, D. L., Mandjukov, P. B., Stratis, J. A,, Elec- trothermal atomisation atomic absorption spectrometric determination of inorganic and methylated arsenic after pre-concentration by hydride generation and trapping the hydrides in a cerium(1V) - iodide absorbing solution, J . Anal. At. Spectrom., 1987, 2, 135. (Fac. Chem., Univ. Sofia, Sofia 1126, Bulgaria). Shand, C. A., Ure, A. M., Graphite furnace atomic absorption spectrometric determination of selenium in plant materials following combustion in a stream of oxygen, J.Anal. At. Spectrom., 1987, 2 , 143. (The Macaulay Inst. for Soil Res. , Craigiebuckler, Aberdeen AB9 2QJ, UK). Saeed, K., Direct electrothermal atomisation atomic absorption spectrometric determination of selenium in whole blood and serum with continuum-source back- ground correction, J. Anal. At. Spectrom., 1987, 2, 151. (Collett-Marwell Hauge Ltd. , Pharma Division, PO Box 205 N-1371 Asker, Norway). Bonilla, M., Rodriguez, L., Camara, C., Determination of lead in biological materials by atomic absorption spec- trometry sensitised with hydride generation, J . Anal. At. Spectrom. , 1987, 2, 157. (Dept. Quim. Anal., Fac. Cienc. Quim., Univ. Complutense de Madrid, 28040 Madrid, Spain). Bermejo-Barrera, P., Bermejo-Martinez, F., Cocho de Juan, J.A., Determination of vanadium in urine by electrothermal atomisation atomic absorption spec- trometry, J . Anal. At. Spectrom., 1987, 2 , 163. (Dept. Anal. Chem. , Fac. Chem. , Univ. Santiago de Compostela, Santiago de Compostela, Spain). Brajter, K., Monawska, K., Determination of gold in the presence of platinum and palladium by electrothermal atomisation atomic absorption spectrometry, J. Anal. At. Spectrom. , 1987, 2, 167. (Dept. Chem. , Univ. Warsaw, Pasteura 1, 02-093 Warsaw, Poland). Shuttler, I. L., Delves, H. T., Between-batch variability of thermal characteristics of commercially available L’vov platform graphite tube atomisers and analytical accuracy in electrothermal atomisation atomic absorption spec- trometry, J.Anal. At. Spectrom., 1987, 2, 171. (Trace Element Unit, Univ. Chem. Pathol. and Human Metabol- ism, Univ. Southampton, Southampton Gen. Hosp. , Southampton SO9 4XY, UK). 87/1727. 8711728. 8711729. 8711730. 8711731. 8711732. 8711733. 8711734. 8711735. 8711736. 8711737. 87J1738. 8711739. Sanz-Medel, A., Rodriguez Roza, R., Gonzalez Alonso, R., Nova1 Vallina, A., Cannata, J., Atomic spectrometric methods (atomic absorption and inductively coupled plasma atomic emission) for the determination of alumi- nium at the part per billion level in biological fluids, J. Anal. At. Spectrom., 1987, 2 , 177. (Dept. Quim. Anal., Fac. Quim., Univ. Oviedo, Ovideo, Spain). Thompson, M., Ramsey, M. H., Coles, B. J., Du, C. M., Correction of matrix effects in inductively coupled plasma atomic emission spectrometry by interactive power adjust- ment, J.Anal. At. Spectrom., 1987, 2, 185. (Appl. Geochem. Res. Group, Dept. Geol. , Imperial College Sci. and Technol., London SW7 2BP, UK). Hall, G. E. M., Park, C. J., Pelchat, J. C., Determination of tungsten and molybdenum at low levels in geological materials by inductively coupled plasma mass spec- trometry, J. Anal. At. Spectrom., 1987, 2, 189. (Geol. Surv. Canada, 601 Booth St., Ottawa, Ontario K1A OE8, Canada). Boampong, C., “Brindle, I. D., Ponzoni, C. M. C., Determination of arsenic by hydride generation in the d.c. plasma atomic emission spectrometer-determination of arsenic(II1) and arsenic(V) as total arsenic, J . Anal. At. Spectrom., 1987, 2, 197. (Chem. Dept., Brock Univ., St. Catharines, Ontario L2S 3A1 , Canada). Brown, A.A,, Roberts, D. J., Kahokola, K. V., Methods for improving the sensitivity in flame atomic absorption spectrometry, J. Anal. At. Spectrom., 1987, 2, 201. (Pye Unicam, York St., Cambridge CB1 2PX, UK). Ebdon, L., Hill, S. J., Jones, P., Interface system for directly coupled high-performance liquid chromatography - flame atomic absorption spectrometry, J. Anal. At. Spectrom. , 1987, 2 , 205. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Martinez Jimenez, P., Gallego, M., Valcarcel, M., Indirect atomic absorption determination of chloride by continuous precipitation of silver chloride in a flow injection system, J. Anal. At. Spectrom., 1987, 2, 211. (Dept. Anal. Chem., Fac. Sci., Univ.Cordoba, Cbrdoba, Spain). Bysouth, S. R., Tyson, J. F., Flow manifold for automated on-line dilution of standards for flame atomic absorption spectrometry and its use in a null measurement method, 1. Anal. At. Spectrom., 1987, 2 , 217. (Dept. Chem., Univ. Technol., Loughborough, Leicester LEll 3TU, UK). Garcia, I. L., O’Grady, C., *Cresser, M. S., Pneumatic nebulisers-poor pumps and inferior sub-samplers, J. Anal. At. Spectrom. , 1987, 2 , 221. (Dept. Soil Sci., Univ. Aberdeen, Old Aberdeen AB9 2UE, UK). Thorne, A. P., High-resolution Fourier transform atomic spectrometry, J. Anal. At. Spectrom., 1987, 2, 227. (Blackett Lab. , Imperial College Sci. and Technol., London SW7 2BZ, UK). Dawson, J. B., Duflield, R. J., Kersey, A. D., Hajizadeh- Saffar, M., Fisher, G.W., Atomic magneto-optical rotation spectroscopy (AMORS) using a rotating polariser and a segmented graphite rod atomiser, J . Anal. At. Spectrom., 1987, 2, 233. (Dept. Med. Phys., General Infirmary, Leeds LS1 3EX, UK). Steers, E. B. M., Fielding, R. J., Charge-transfer excita- tion processes in the Grimm lamp, J. Anal. At. Spectrom. , 1987, 2 , 239. (Dept. Electronic and Commun. Eng. and Appl. Phys., Polytech. North London, Holloway, London N7 8DB, UK). Warren, P. L., Farges, O., Horton, M., Humber, J., Role of energy dispersive X-ray fluorescence spectrometry in process analysis of plastic materials, J. Anal. At. Spec- trom., 1987, 2 , 245. (Petrochem. and Plastics Div., Imperial Chemical Industries plc, PO Box No. 90, Wilton, Middlesbrough, Cleveland TS6 8JE, UK).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 207R 8711740, 8711741. 8711742. 8711743. 871 1 744. 8711745. 8711746. 8711747. 8711748. 8711749. 871 1750. 8711751, Lewin, K., Walsh, J. N., *Miles, D. L., Determination of dissolved sulphide in groundwaters by inductively coupled plasma atomic emission spectrometry, J. Anal. At. Spec- trom., 1987, 2, 249. (Hydrogeol. Res. Group, British Geol. Surv., Wallingford, Oxfordshire OX10 8BB, UK). Timmins, K. J., Excitation of gallium, indium, selenium, tellurium, arsenic and antimony in a helium microwave- induced plasma, J. Anal. At. Spectrom., 1987, 2, 251. (Directorate of Quality AssuranceITech. Support, Materials Centre, Royal Arsenal East, Woolwich, London SE18 6TD, UK). Bustos, A., Sanchez-Rojas, F., Bosch Ojeda, C., Garcia de Torres, A., Can0 Pavon, J.M., Use of 1,5-bis(di-2- pyridylmethy1ene)thiocarbonohydrazide as an extracting reagent for the determination of some transition metal ions by atomic absorption spectrometry, J. Anal. At. Spec- trom., 1987, 2, 253. (Dept. Anal. Chem., Fac. Sci., Univ. Mglaga, 29071 MAlaga, Spain). Andersen, J. R., Graphite furnace atomic absorption spectrometric screening method for the determination of aluminium in haemodialysis concentrates, J. Anal. At. Spectrom., 1987, 2, 257. (Royal Danish Sch. Pharm., Dept. Chem. AD, 2 Universitetsparken, DK-2100 Copen- hagen, Denmark). Mitchell, M. C., Berrow, M. L., Shand, C. A., Direct determination of cobalt in acetic acid extracts of soils by graphite furnace atomic absorption spectrometry, J.Anal. At. Spectrom., 1987,2,261. (Macaulay Inst. for Soil Res., Craigiebuckler, Aberdeen AB9 2QJ, UK). Barbera, R., Irles, J., Farre, R., Elimination of iron interference and use of APDC and NaDDC as chelating agents in the determination of Co in foods by AAS, At. Spectrosc., 1986,7,151. (Dept. Food Chem., Toxicol. and Anal. Chem., Fac. Pharm., Univ. Valencia, 46010-Valen- cia, Spain). Stock, D. J., The indirect determination of sulphate in pulp-mill effluents by AAS, At. Spectrosc., 1987, 8, 1. (Crown Forest Industries Ltd., PO Box 2000, Campbell River, British Columbia V9W 5C9, Canada). Subramanian, K. S., Determination of Pb in blood: comparison of two GFAAS methods, At. Spectrosc., 1987, 8, 7. (Environ. Health Directorate, Health and Welfare Canada, Tunney’s Pasture, Ottawa, Ontario K1A OL2, Canada). Stafilov, T., Todorovski, T., Determination of Au in arsenic antimony ore by flameless AAS, At.Spectrosc., 1987, 8, 12. (Inst. of Mining and Metallurgy, Mining and Ironworks, “Skopje,” PO Box 454, 91000 Skopje, Yugos- lavia). Lust, A., An atomic spectroscopy bibliography for July- December, 1986, At. Spectrosc., 1987, 8, 15. (Perkin- Elmer Corp., 761 Main Ave., Norwalk, CT 06859-0906, USA). Eckerlin, R. H., Hoult, D. W., Carnrick, G. R., Se determination in animal whole blood using stabilised temperature platform furnace and Zeeman background correction, At. Spectrosc., 1987, 8, 64. (Toxicol. Lab., New York State Coll. of Veterinary Medicine, Cornell Univ., Ithica, NY 14850, USA). Rios, C., Valero, H., Sanchez, T., Li determination in plasma and erythrocytes using furnace AAS, At.Spec- trosc., 1987, 8, 67. (Inst. Nacional de Neurolagy Neuroci- rugia Secretaria de Salud, Insurgentes sur 3877, Mexico 22, DF, Mexico). Papers 871C1752-871C1757 were presented at the Atomic Spectrometry Updates Symposium, Thames Polytechnic, Woolwich, London, UK, 8th April, 1987. 871C1752. Rossi, G., An overview of the activities of the spectroscopy sector at the Joint Research Centre of ISPRA, (Chem. Div., JRC Establishment of Ispra, Italy). 87lC 1753. 87lC1754. 87lC1755. 87lC1756. 87lC1757 8711758. 8711759. 8711760. 8711761. 8711762. 8711763. 8711764. 8711765. 8711 766. Haswell, S. J., “Trace element speciation”: does it work in theory?, (Sch. Chem., Thames Polytech., Wellington St., Woolwich, London SE18 6PF, UK).Sparkes, S. T., Long, S. E., Speciation of organic compounds of radionuclides by HPLC - ICP-MS, (Envi- ron. Med. Sci. Div. B551, Harwell Lab., Didcot, Oxford- shire OX11 ORA, UK). Stephens, R., Fields, photons and elemental analysis, (Dept. Chem., Dalhousie Univ., Halifax, Nova Scotia B3H 453, Canada). Fielden, P. R., Chromatographic separation and detection methods for speciation studies, (Dept. Instrumentation and Anal. Sci., UMIST, PO Box 88, Manchester M60 lQD, UK). Hill, S. J., Ebdon, L., Bancroft, K. C. C., O’Neill, P., The speciation of arsenic in environmental and food samples, (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Szefer, P., Szefer, K., Some metals and their possible sources in rainwater of the southern Baltic coast, 1976 and 1978-1980, Sci.Total Environ., 1986,57,79. (Dept. Anal. Chem., Med. Acad., PL 80-416 Gdansk, Poland). Date, A. R., Hutchison, D., Determination of rare earth elements in geological samples by inductively coupled plasma source mass spectrometry, J. Anal. At. Spectrom., 1987, 2, 269. (British Geol. Surv., 64 Gray’s Inn Rd., London WClX 8NG, UK). McLaren, J. W., Beauchemin, D., Berman, S. S., Deter- mination of trace metals in marine sediments by induc- tively coupled plasma mass spectrometry, J . Anal. At. Spectrom., 1987, 2, 277. (Div. Chem., Natl. Res. Counc. Canada, Ottawa K1A OR9, Canada). Houk, R. S., Schoer, J. K., Crain, J. S., Plasma potential measurements for inductively coupled plasma mass spec- trometry with a centre-tapped load coil, J.Anal. At. Spectrom., 1987, 2 , 283. (Ames Lab.-USDOE and Dept. Chem., Iowa State Univ., Ames, IA 50011, USA). Dedina, J., *Frech, W., Lindberg, I., Lundberg, E., Cedergren, A., Determination of selenium by graphite furnace atomic absorption spectrometry. Part 1. Interac- tion between selenium and carbon, J . Anal. At. Spectrom., 1987, 2, 287. (Dept. Anal. Chem., Univ. Umel, S-901 87 Umeb, Sweden). Egila, J., *Littlejohn, D., Ottaway, J. M., Xiao-quan, S., Comparison of interferences and matrix modifiers in the determination of gold by electrothermal atomisation atomic absorption spectrometry with Zeeman-effect back- ground correction, J . Anal. At. Spectrom., 1987, 2, 293. (Dept. Pure and Appl. Chem., Univ. Strathclyde, 295 Cathedral Street, Glasgow G1 lXL, UK).Xiao-quan, S., Egila, J., *Littlejohn, D., Ottaway, J. M., Direct determination of gold in whole blood and plasma by electrothermal atomisation atomic absorption using Zee- man-effect background correction and matrix modifica- tions, J . Anal. At. Spectrom., 1987, 2, 299. (Dept. Pure and Appl. Chem., Univ. Strathclyde, 295 Cathedral St., Glasgow G1 1x2, UK). Halls, D. J., Black, M. M., Fell, G. S., Ottaway, J. M., Direct determination of cadmium in urine by electrother- mal atomisation atomic absorption spectrometry, J . Anal. At. Spectrom., 1987, 2, 305. (Trace Metals Unit, Dept. Biochem., Glasgow Royal Infirmary, Castle St., Glasgow G4 OSF, UK). Curtius, A. J., Schlemmer, G., *Welz, B., Determination of phosphorus by graphite furnace atomic absorption spectrometry.Part 3. Analysis of biological reference materials, J. Anal. At. Spectrom., 1987, 2 , 311. (Dept. Appl. Res., Bodenseewerk Perkin-Elmer & Co. GmbH. D-7770 Uberlingen, FRG).208R 8711767. 8711768. 8711769. 8711770. 8711771. 8711 772. 8711773. 8711774. 8711775. 8711 776. 8711777. 8711778. 87/1779. 8711 780. JOURNAL OF ANALYTICAL Ebdon, L., Evans, E. H., Determination of copper in biological microsamples by direct solid sampling graphite furnace atomic absorption spectrometry, J. Anal. At. Spectrom., 1987, 2, 317. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Plymouth, Devon PL4 8AA, UK). Kamata, E., Nakashima, R., Furukawa, M., Determina- tion of trace amounts of thorium and uranium in coal ash by inductively coupled plasma atomic emission spec- trometry after extraction with 2-thenoyltrifluoroacetone and back-extraction with dilute nitric acid, J .Anal. At. Spectrom., 1987, 2, 321. (Government Ind. Res. Inst., Nagoya, 1-1 Hirate-cho, Kita-ku, Nagoya 462, Japan). Ebdon, L., Wilkinson, J. R., Direct atomic spectrometric analysis by slurry atomisation. Part 3. Whole coal analysis by inductively coupled plasma atomic emission spec- trometry, J . Anal. At. Spectrom., 1987, 2, 325. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Ply- mouth, Devon PL4 8AA, UK). KoScielniak, P., Preparation of solutions for the standard additions method in flame atomic absorption spec- trometry, J. Anal. At. Spectrom., 1987, 2, 329. (Dept. Anal. Chem., Jagiellonian Univ., ul.Karasia 3, 30-060 Krakdw , Poland). El-Defrawy, M. M., Khalifa, M. E., *Abdallah, A. M., Akl, M. A., Removal of phosphate and silicate interfer- ences in the determination of magnesium, calcium and strontium by atomic absorption spectrometry, J. Anal. At. Spectrom., 1987, 2, 333. (Dept. Chem., Fac. Sci., Univ. Mansoura, PO Box 30, Mansoura, Egypt). Evmiridis, N. P., Townshend, A., Determination of sulphur compounds by fully automated molecular emission cavity analysis, J. Anal. At. Spectrom., 1987, 2, 339. (Chem. Dept., Univ. Hull, Hull HU6 7RX, UK). Brown, A. A., Halls, D. J., Taylor, A., Atomic Spec- trometry Update-clinical and biological materials, foods and beverages, J. Anal. At. Spectrom., 1987,2,43R. (Pye Unicam Ltd., York St., Cambridge CB1 2PX, UK).Denton, M. B., Concepts for improved automated labora- tory productivity, Analyst, 1987, 112, 347. (Dept. Chem., Univ. Arizona, Tucson, AZ 85721, USA). L’vov, B. V., Recent advances in the theory of atomisation in graphite furnace atomic absorption spectrometry: the oxygen - carbon alternative, Analyst, 1987, 112, 355. (Dept. Anal. Chem., Polytech. Inst., Leningrad 195251, USSR). Tolg, G., Extreme trace analysis of the elements-the state of the art today and tomorrow, Analyst, 1987, 112, 365. (Inst. fur Spektrochem. und angewandte Spektrosk. in Dortmund und Lab. of Reinststoffanalytik des Max- Planck-Institutes fur Metalforschung in Stuttgart , Bunsen- Kirchhoff.-Str. 11113, D-4600 Dortmund 1, FRG). Ripley, B. D., Thompson, M., Regression techniques for the detection of analytical bias, Analyst, 1987, 112, 377.(Dept. Math., Univ. Strathclyde, Glasgow G1 lXH, UK). Ebdon, L., Hill, S. J., Jones, P., Application of directly coupled flame atomic absorption spectrometry - fast protein liquid chromatography to the determination of protein-bound metals, Analyst, 1987, 112, 437. (Dept. Environ. Sci., Plymouth Polytech., Drake Circus, Ply- mouth, Devon PL4 8AA, UK). Beary, E. S., Brletic, K. A., Paulsen, P. J., Moody, J. R., A comparison of isotope dilution mass spectrometric methods for the assay of copper in copper ore reference materials, Analyst, 1987, 112, 441. (Cent. Anal. Chem., Natl. Bur. Stand., Gaithersburg, MD 20899, USA). Brackenbury, K. F. G., Jones, L., *Koch, K. R., Poly- urethane foams as sorbents for noble metals.Selective pre-concentration of small amounts of platinum from hydrochloric acid containing tin(I1) chloride followed by flame atomic absorption analysis, Analyst, 1987, 112,459. (Dept. Anal. Sci., Univ. Cape Town, Private Bag, Rondebosch 7700, South Africa). 8711781. 8711782. 8711783. 8711784. 8711785. 8711 786. 8711787. 8711788. 8711789. 8711790. 87/1791. 8711792. 8711793. 8711794, ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 Hirayama, K., Leyden, D. E., Determination of trace amounts of vanadium(1V) and -(V) in water by energy- dispersive X-ray fluorescence spectrometry combined with pre-concentration and separation, Anal. Chim. Acta, 1986, 188, 1. (Dept. Chern., Colorado State Univ., Fort Collins, CO 80523, USA). LaBrecque, J. J., Rosales, P. A., Mejias, G., Simultaneous determination of lanthanides by radioisotope X-ray flu- orescence spectrometry based on characteristic K-radia- tion, Anal.Chim. Acta, 1986, 188, 9. (Instituto Venezol- ano de Investigaciones, Cientificas (IVIC), Apartado 1827, Caracas 1020-A, Venezuela). Christensen, L. H., Drabaek, I., Energy-dispersive X-ray fluorescence spectrometry of industrial paint samples, Anal. Chim. Acta, 1986,188,15. (Isotope Div., Ris@ Natl. Lab., DK-4000 Roskilde, Denmark). Mantler, M., X-ray fluorescence analysis of multiple-layer films, Anal. Chim. Acta, 1986, 188, 25. (IBM Res. Lab. San Jose, San Jose, CA 95193, USA). Rachetti, A., Wegscheider, W., A fundamental parameters approach including scattered radiation for mono-energet- ically excited samples in energy-dispersive X-ray fluores- cence spectrometry, Anal.Chim. Acta, 1986, 188, 37. (Inst. Anal. Chem., Mikro- und Radiochem., Tech Univ. Graz, Technikerstrasse 4, A-8010 Graz, Austria). Gilfrich, J. V., Multi-layered structures as dispersing devices in X-ray spectrometry, Anal. Chim. Acta, 1986, 188, 51. (Naval Res. Lab., Washington, DC 20375-5000, USA). Wegscheider, W., Ellis, A. T., Goldbach, K., Leyden, D. E., Mahan, K. I., Use of sensitivity as a function of fluorescent X-ray energy in energy-dispersive X-ray spec- trometry, Anal. Chim. Acta, 1986, 188, 59. (Inst. Anal. Chem., Micro- and Radiochem., Tech. Univ. Graz, Technikerstrasse 4, Graz A-8010, Austria). Salvador, V. L. R., Imakuma, K., Determination of trace metals in nuclear-grade uranium dioxide by X-ray fluores- cence spectrometry, Anal.Chim. Acta, 1986, 188, 67. (Comissiio Nacl. de Energia Nuclear, Inst. de Pesquisas Energeticas e Nucleares, Caixa Postal 11049, Sdo Paulo, SP, Brad). Ward, T. J., Armstrong, D. W., Czech, B. P., Koszuk, J. F., Bartsch, R. A., Effect of crown-ether surfactants on flame atomic absorption and flame emission signals of some monovalent cations, Anal. Chim. Acta, 1986, 188, 301. (Dept. Chem. and Biochem., Texas Tech Univ., Lubbock, TX 79406, USA). Nyarku, S. K., Delmage, M., Szturm, K., Determination of selected trace metals in scallops by flame atomic absorption spectrometry after removal of sodium on hydrated antimony pentoxide, Anal. Chim. Acta, 1986, 188, 307. (Chem. Dept., Brandon Univ., Brandon, Manitoba R7A 6A9, Canada). Hemens, C. M., *Elson, C. M., Determination of micro- gram amounts of arsenic in geological materials and waters by wavelength-dispersive X-ray fluorescence spec- trometry, Anal. Chim. Acta, 1986, 188, 311. (Dept. Chem., Saint Mary’s Univ., Halifax, Nova Scotia B3H 3C3, Canada). Legret, M., Divet, L., Determination de l’etain dans les sediments et les boues de stations d’epuration par spec- trometrie d’absorption atomique avec generation d’hy- drures, Anal. Chim. Acta, 1986, 189, 313. (Laboratoire Central des Ponts et Chausskes, B.P. 19, 44340 Bougue- nais, France). Sanz-Medel, A., Analytical spectroscopy in Spain, Eur. Spectrosc. News, 1987,70,25. (Dept. Anal. Chem., Univ. Oviedo, Oviedo, Spain). Waiters, P. E., Nieuwoudt, G., The determination of transition probabilities of argon spectral lines with a 27.12-MHz ICP, S. Afr. J. Phys., 1986, 9, 131. (Dept. Phys., Univ. Stellenbosch, Stellenbosch 7600, South Africa).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 209R 87/1795. 87/1796. 87/1797. 87/1798. Moenke-Blankenburg, L., Laser micro analysis, Prog. Anal. Spectrosc., 1986, 9, 335. (Dept. Chem., Martin- Luther-Univ., GDR 4050 HalleISaale, GDR). 87/1799. O’Haver, T. C., Messman, J. D., Continuum source atomic absorption spectrometry, Prog. Anal. Spectrosc., 1986, 9, 483. (Dept. Chem. Biochem., Univ. Maryland, College Park, MD 20742, USA). 87/1800. Nakamura, S., Kubota, M., Effects of alkali and alkaline earth salts on signal absorbance in electrothermal AAS, Bunseki Kagaku, 1986, 35, 961. (Natl. Chem. Lab. Ind., Yatabe, Japan). 87/1801. Vieira, P. A,, He, Z., Chan, S. K., Montaser, A., Evaluation of recycling cyclone spray chambers for ICP- AES, Appl. Spectrosc., 1986, 40, 1141. (Dept. Chem., George Washington Univ., Washington, DC 20052, USA). 87/1802. Mikhailova, M., Angelova, Ts., Direct atomic absorption spectrometric determination of molybdenum in fluoride solutions containing titanium, tantalum, tungsten and nickel, Khim. Znd. (Sofia), 1986,58,261. (Inst. Metalloke- ram. Sofia, Bulgaria). Albers, D., Sacks, R., Direct atomic emission determina- tion of some trace metals in solid powder samples with a magnetically tailored capacitive discharge plasma, Anal. Chem., 1987, 59, 593. (Dept. Chem., Univ. Michigan, Ann Arbor, MI 48109, USA). Xu, L., Rao, Z., Determination of boron in soils by sequential scanning ICP-AES using side line indexing method, Fresenius 2. Anal. Chem., 1986, 325, 534. (Shanghai Inst. Metall., Acad. Sin., Shanghai 200050, China). Ma, Y., Cheng, J., Comparative study on several tubular atomisers for determination of cobalt with graphite fur- nace atomic absorption spectrometry, Fenxi Huaxue, 1986, 14, 746. (Inst. Environ. Chem., Acad. Sin., China).

ISSN:0267-9477    

DOI:10.1039/JA987020199R

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

210R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 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. a.c. AA AAS AE AES AF AFS APDC ASV CMP CRM cw d.c. DCP DMF DNA EDL EDTA ETA FAAS FAES FAFS FI GC GDL HCL h.f. HPLC IBMK ED-XRF alternating current atomic absorption atomic absorption spectrometry atomic emission atomic emission spectrometry atomic fluorescence atomic fluorescence spectrometry ammonium pyrrolidinedithiocarbamate (ammonium tetramethylenedithio- carbamate) anodic-stripping voltammetry capacitively coupled microwave plasma certified reference material continuous wave direct current d.c.plasma N, N-dimet h ylformamide deoxyribonucleic acid electrodeless discharge lamp ethylenediaminetetraacetic acid energy dispersive X-ray fluorescence electrothermal atomisation flame AAS flame AES flame AFS flow injection gas chromatography glow discharge lamp hollow-cathode lamp high-frequency high-performance liquid chromatography isobutyl methyl ketone (4-methylpentan- 2-one) ICP IR LC LTE MECA MIP MS NAA NaDDC NTA OES PMT p.p.b. p.p.m. PTFE r.f. REE RM RSD SBR SEM SNR SSMS TCA TLC TOP0 u.h.f. uv VDU vuv WD-XRF XRF inductively coupled plasma infrared liquid chromatography local thermal equilibrium molecular emission cavity analysis microwave-induced plasma mass spectrometry neutron activation analysis sodium diethyldithiocarbamate nitrilotriacetic acid optical emission spectrometry photomultiplier tube parts per billion parts per million polytetrafluoroethylene radiofrequency rare earth element reference material relative standard deviation signal to background ratio scanning electron microscopy signal to noise ratio spark-source mass spectrometry trichloroacetic acid thin-layer chromatography trioctylphosphine oxide ultra-high-frequency ultraviolet visual display unit vacuum ultraviolet wavelength dispersive X-ray fluorescence X-ray fluorescence

ISSN:0267-9477    

DOI:10.1039/JA987020210R

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

649 Atomic Spectrometry Viewpoint James W. McLaren Division of Chemistry, National Research Council of Canada, Ottawa KIA OR9, Canada During the Post-CSI Symposium on ICP-MS at Muskoka Sands (28th-30th June, 1987) Judith Egan (Editor) talked to Jim McLaren about his involvement with ICP-MS and the meeting at Muskoka. Could you tell us something about where you studied and how you came to work at NRC (National Research Council) in 0 tta w a ? I did a Bachelor’s degree in Chemistry and a Master’s degree in Inorganic Che- mistry at the University of Toronto. I then went to Queen’s University in Kingston, Ontario, to do a PhD in Analytical Chemistry. My F’hD project involved the determination of trace metals is suspen- ded particulate matter collected from Lake Ontario. My PhD supervisor was Professor Wally Breck and I finished my PhD in 1976.During the time that I was at Queen’s I met Dr. Shier Berman, the current Head of the Analytical Chemistry Section of the National Research Council, who was at Queen’s as a visiting lecturer. It was Shier who invited me to apply for a position as a Research Associate at the National Research Council. I went to NRC immediately after finishing my PhD, that was in October of 1976, and approximately a year and a half later I joined the permanent staff of the National Research Council, Analytical Chemistry Section, as a Research Officer. Would you give us a brief uutline of what exactly the NRC is, for example how it is funded, how it functions and the main areas of research that it is concerned with? The National Research Council is the principal research and development agency of the Federal Government of Canada.It has approximately 3000 employees, about a half to two-thirds of whom are situated in Ottawa. The part of the Chemistry Division in which I work is located at the so called Montreal Road campus, the largest concentration of NRC laboratories anywhere in the country. The funding for the National Research Coun- cil comes from the Federal Treasury, through the Ministry of State for Science and Technology. There is a very wide range of research activities at the NRC. There are divisions of physics, chemistry, biology, electrical engineering, mechan- ical engineering, etc. Even within the Chemistry Division, which presently con- sists of approximately 170 staff, there is a very wide range of research activities.The Chemistry Division consists of 12 research groups, one of which is the Analytical Chemistry Section. At the moment our section has 19 staff members, that is scientists and technicians, with three major areas of activity. First of all, we provide a comprehensive analytical ser- vice facility in support of the wide variety of research projects ongoing in the Che- mistry Division and in other NRC Divi- sions. For about the last 10 years we have also been involved in a programme called the Marine Analytical Chemistry Stan- dards Programme, which was set up at the request of the oceanographic community in Canada to try to improve the quality of marine analytical data. The third area where we have been active over the years, is fundamental research and development in inorganic trace analysis, especially in applications development.It was because of our expertise in inorganic trace analysis that we became involved in the Marine Analytical Chemistry Standards Pro- gramme. One aspect of this programme has been the production of a series of marine reference materials with reliable values for inorganic trace constituents and that has provided us with a convenient and often a very challenging vehicle for applications development for a variety of techniques for inorganic trace analysis. What are your own research interests? My own expertise initially was in the area of inductively coupled plasma atomic emission spectrometry. My first project when I joined the Council was to build a custom ICP spectrometer consisting of a Plasma Therm ICP source and an echelle grating spectrometer.For the last three years though, I have devoted almost all of my rmearch efforts to inductively coupled plasma mass spectrometry, since the installation of one of the first commer- cially available SCIEX ELAN ICP-MS systems in May, 1984. You have obviously been involved with ICP-MS from the early stages. How did this come about? My first awareness or involvement in the field of plasma mass spectrometry came early in 1980. I received a telephone call from Don Douglas at SCIEX, whom I didn’t know at the time. He wanted to borrow my ultrasonic nebuliser. He had heard me giving a talk at a meeting in Toronto the previous fall, where I dis- cussed the use of an ultrasonic nebuliser for some ICP emission work.Unbeknown to me Don was at that time working on a microwave induced plasma - mass spec- trometer combination which involved the use of an ultrasonic nebuliser. Just at the wrong moment his ultrasonic nebuliser broke down and he needed to borrow one. So he called me, and this was when I first became aware of activities at SCIEX. I was fascinated with the idea of using plasma sources in combination with mass spectrometry, and I have followed devel- opments, especially at SCIEX, very closely since that time. One of the reasons, in fact the major reason, why we were able to acquire our ICP-MS instrumentation so early was that there was a major Federal Government pro- gramme to assist a Canadian corporation to bring a new type of instrumentation to market, and in order for a company to receive funding under this programme the equipment developed had to be of interest to a certain number of Federal Govern- ment laboratories.So sometime in 1982 SCIEX submitted a proposal to the Source Development Fund, as it was called, and the approval of the funding which they requested was contingent upon a certain amount of enthusiasm by key Federal Government laboratories. This was an ideal opportunity both for SCIEX and for me to become involved in a fairly close collaboration and the happy consequence of this for me was that I was able to get special financial assistance in getting an ICP mass spectrometer installed in the Chemistry Division of NRC at a very early stage. How have things progressed since the early days? During the first two years or so, we divided our time roughly equally between applications development, particularly for marine samples, and basic research on the operating characteristics of the650 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 ELAN. We worked very closely with SCIEX, providing them with feedback of our impressions of the performance of the instrument, which was substantially altered and improved by several major modifications during that period. Now it’s been a year-and-a-half since the last modification, so the emphasis has turned increasingly to applications. The first ICP-MS application we pub- lished was the determination of several trace metals in the coastal sea water reference material CASS-1 (Anal.Chem., 1985). That work involved a prior separation and pre-concentration of the metals, but since then we have developed methods for the direct determination of trace metals in solutions of marine sedi- ments and biological tissues. During the past year, we’ve worked on certification of a number of new marine reference materials, including a harbour sediment, two biological tissues and a fresh water sample from the St. Lawrence River. What other areas or developments are you currently involved in? Another interesting area that we are just beginning to get into involves analysis of high-purity materials. We are probably one of the few laboratories in the world outside of VG Isotopes which have both a glow discharge source mass spectrometer, namely the VG 9000 and also the ICP mass spectrometer, in this case the SCIEX ELAN.So one of the areas that we are just getting into now is how we might possibly use the two instruments in combination to work on the analysis of high-purity materials. There is no ques- tion that at the present time a solid sampling method such as glow discharge mass spectrometry can easily out-perform ICP-MS when it comes to detection power for solid samples. The big question mark with glow discharge mass spectrometry is how to achieve an accurate calibration for materials for which no standards exist at present. One approach which we are exploring at the moment is the use of ICP-MS, particularly isotope dilution ICP-MS, to produce reference materials that could be used as calibration standards for glow discharge mass spectrometry.Very recently, we have begun some studies on HPLC - ICP-MS as a means of investigating trace metal speciation in natural waters. You seem to have had a hectic few years, which have also involved a fair amount of travel. I know you have just been to Australia; perhaps you could tell us some- thing about your trip? I certainly have found the last three years extremely exciting, extremely rewarding, probably the best three years of my career at NRC in terms of stimulating experi- ments, stimulating meetings I have atten- ded, and also plenty of very pleasant opportunities for travel to far away places. I guess my most recent and one of the most pleasant experiences I have had in the last regard was my three-week trip to Australia, in April.The primary reason for my trip was to present two lectures at the Ninth Australian Symposium on Analytical Chemistry, which was held this year in Sydney, during the last week of April. My visit was sponsored by the Royal Australian Chemical Institute and one of the nice things about going to Australia is that, since it is rather geo- graphically isolated, invited speakers to a major international meeting such as this are normally also encouraged to travel elsewhere in the country to give lectures to the local sections of the Royal Austral- ian Chemical Institute. This certainly worked to my advantage both in terms of allowing me to make contacts elsewhere in the country and also to explore some of the many touristic possibilities of Aus- tralia.I started my visit in North Queens- land. In fact, most of the first week didn’t involve any work at all! I did give one lecture at the James Cook University of North Queensland in Townsville, and visited some marine research facilities, but most of the rest of the week was devoted to snorkelling on the Great Bar- rier Reef and windsurfing on Dunk Island, which was extremely pleasant but didn’t have much to do with science. During the second week though I did do some real work. I travelled to Darwin in the Northern Territory where I gave a lecture to the Northern Territory local section of the RACI and I also had a very interesting one-day visit to a uranium mine and processing facility in Arnhem Land, about 300 km east of Darwin. During the latter part of that second week I visited Perth, where I gave a lecture at the Curtin University of Technology and another lecture at the CSIRO Division of Ground Water Chemistry. As I men- tioned earlier, the final week of my three-week trip to Australia was spent in Sydney attending the Ninth Australian Symposium on Analytical Chemistry.I found the Australians to be wonderful hosts. The interest level in ICP-MS is extremely high; at the present time there is only a single ICP-MS instrument in Australia, but there is a very high degree of interest in the technique. You sound as if you were very impressed by Australia both from the work point of view and as a great place to visit and relax. Well. . . , just let me say that in a place like Dunk Island, one has the opportunity to appreciate natural beauty in many forms! I can highly recommend it to any spectro- scopist who needs to unwind a little.The atmosphere is very conducive to hedon- ism-the weather, the scenery, the variety of recreational activities available (swimming, sailing, windsurfing, water skiing, tennis, squash, etc.). When you add to that the warmth and charm of the Australians, it’s hard to imagine a more pleasant place for a vacation. Seeing the Great Barrier Reef was another highlight of my trip. Even though I’d heard and read a lot about it, the diversity and beauty of the coral and the reef fish was exhilarating. You, along with Chris Riddle, have done an excellent job organising this sympo- sium. How did you come to be involved? The idea of organising this symposium on ICP-MS at Muskoka Sands arose from two separate sources.We had a workshop on ICP-MS in Toronto in the fall of 1985, organised by Chris Riddle. It was more or less agreed at the time of the Toronto workshop that we would try to hold another meeting approximately two years later. However, in the intervening time I was also approached by the 25th CSI Organising Committee with the idea of organising either a pre- or post-CSI Sym- posium on ICP-MS. So when next I talked with Chris I suggested that perhaps we should put these two ideas together and have an ICP-MS Symposium in conjunc- tion with the CSI. As far as choosing the location, I thought that it would be especially attractive to our international visitors to see a different part of the country outside of the obviously urban Toronto setting.So Chris set about to canvas several potentially suitable loca- tions. We agreed that Muskoka Sands was the best possible location for a meeting such as this, in as much as it was reason- ably close to Toronto and offered a beautiful physical setting and an atmos- phere quite different from downtown Toronto. We are now half-way through the meeting. How do you view its success or otherwise so far and what were your main objectives when planning the meeting? Barring some disaster which may befall us between now and the end of the meeting I think that it is fair to say that Muskoka Sands has been an unqualified success. First of all, we have really been over- whelmed with attendants; we took as many people as we could-we had 115 registrations.The people attending the meetings probably represent something like at least 30 different ICP-MS user groups. We had a series of invited lectures by six people who have been prominent in the pioneering work in ICP-MS. All the rest of the papers were in poster format. We have just been looking at the posters this afternoon, and I think its remarkable to see the quality and complexity of the work that is being accomplished by people who in many cases have had their instru- ments for not much more than 2 years. Socially the meeting has been a great success, I think. I hoped that by having the meeting at a resort we would have a less formal atmosphere than one normallyJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 65 1 gets at the CSI.We have been blessed with good weather for the social events and this has certainly fostered a feeling of cameraderie among the people who are attending that I think is going to make the free exchange of information quite a bit easier for some people than it has been in the past. When we were planning the Muskoka Sands Symposium we knew that it would be following the CSI, and that there would probably be a substantial number of ICP-MS papers at the CSI, so we needed to make Muskoka Sands dif- ferent. I encouraged the invited speakers to save their most recent results, or their most controversial results, for Muskoka Sands and I certainly was not disap- pointed. All of us who attended most if not all of the lectures on ICP-MS at the CSI felt, I think, that we got something quite different and in some ways more exciting from the six invited lectures this morning than we got at the CSI.We deliberately left a lot of time in the programme for informal conversation and small group discussions. The majority of the people at this meeting are specialists already. They already have considerable experience with ICP-MS and we hoped this would be an ideal opportunity for a very large number of these people to discuss the details of what they are doing rather than the generalities that one feels obliged to present in a lecture to a more general audience. Do you anticipate another symposium in the near future? I guess it’s already assumed that we will probably have another ICP-MS sympo- sium of some description approximately two years from now, although exactly what form it will take I cannot say at the moment.It is obvious that the use of the technique is expanding rapidly and cer- tainly in the present location we could not accommodate a much larger meeting than we have at the moment. We actually had to turn people away because we did not have an adequate number of rooms in the resort and it’s clear that if an even larger number of people want to attend a meet- ing two years down the road we will need a larger location unless we severely res- trict registration. In a way, if it were possible to do so, I would like to keep the meeting at this size. First of all, it’s nice to be able to occupy totally the resort, it is nice to get a resort in a relatively isolated location so that people are not distracted, they don’t wander off to various restaur- ants all over the city for example. I think that there is an informal atmosphere that is a natural consequence of having a meeting in a resort location that encour- ages discussion and perhaps a more free exchange of opinions and ideas than would occur in a more formal setting. So in a way I’d like to see something like this meeting, not much bigger, occur in two years time. But whether that will be possible or easy if ICP-MS and the use of ICP-MS continues to expand as quickly as it has in the last two years, its difficult to know. Thank you for sparing the time during these busy few days to talk to me. I have certainly found the Symposium interesting and useful, as I am sure everyone else has. W e are very aware of how interest in ICP- MS is increasing so rapidly and hence we are planning to have an “ICP-MS issue” of JAAS in February 1988, contain- ing submitted papers from this Symposium and from the Workshop in Guildford next week.

ISSN:0267-9477    

DOI:10.1039/JA9870200649

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 65 1 Conference Reports XXV Colloquium Spectroscopicum Internationale: 21 st-26th June, 1987, Toronto, Ontario, Canada To many analytical spectroscopists (the laureates A. L. Schawlow and G. Herz- general response to this arrangement was author included), the CSI is the most berg. Thereafter, the various sessions very favourable. eagerly awaited of all conferences. In were generally headed by keynote lec- The traditional CSI structure with ses- terms of scientific content and interna- tures of only 30 minutes duration. The sions throughout Monday, Tuesday, tional flavour the XXV CSI certainly matched its recent predecessors, but there were also a few disappointments. Repor- tedly, attendance was significantly lower than the organisers had predicted, and there seemed to be an unusually large proportion of cancelled papers.Of 407 scheduled presentations, I counted about 90 cancellations. All contributions were oral ( i e . , there were no posters), and so cancellations were more noticeable. Some sessions were reduced to less than 50% of their scheduled length. Those are my only negative comments. The Confer- ence Center at the Hilton Harbour Castle Hotel was well appointed, distances between lecture rooms were mostly short, and the air conditioning effectively com- batted the hot weather which accompan- ied the conference. The organisers put together a programme that broke away from tradition in several ways. The usual string of plenary lectures, in which super- stars give mostly an overview of their specialist areas, was replaced by two Hilton Harbour Castle Hotel and Conference Center on the shores of Lake Ontario, outstanding presentations by Nobel from the top of the CN Tower652 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL.2 Thursday and Friday was maintained. Heading Monday’s programme was Professor Schawlow’s Plenary presenta- tion “Frontiers of Laser Spectroscopy.” Dr. Herzberg’s Plenary lecture, entitled “Molecular Spectroscopy and Astro- nomy,” was on Thursday morning. In both lectures, delegates received a fasci- nating overview that extended beyond the usual analytical chemist’s horizons of spectroscopy. During the week, sessions of interest to atomic spectroscopists were DCP- and MIP-AES, ICP-MS, sample preparation and standards, discharge mechanisms, signal processing and data treatment, sample introduction, optical systems and detection devices, spark, arc and glow discharges, laser spectroscopy, X-ray spectrometry and chromatographic detectors.On most days between five and seven of these sessions ran in parallel. This forced many people to race from room to room, but distances were short and good timekeeping by session chair- men helped the arrangement to work fairly well. In spite of the low attendance at the conference, most of those scientists un- dertaking significant original research in ETA-AAS were present (though obvi- ously there were some notable excep- tions). The ETA-AAS lecture stream was one of the biggest (about 38 papers presented).The extra attraction of the graphite furnace Post-CSI XXV Sympo- sium doubtless influenced many people’s decision to go to Canada. The over-all quality of ETA-AAS papers was high. Fundamental atomisation studies in graphite furnaces predominated, and there were two invited lectures in this area. J. A. Holcombe described how computer modelling with Monte Carlo simulations can predict the dependence of analytical signal on furnace geometry. Further information on the role of oxygen in the graphite furnace, and in particular its reaction with carbon, was provided by R. E. Sturgeon. He measured the partial pressure of CO spectroscopically. From these, and other fundamental contribu- tions, we can take heart that this meeting will have brought us a little closer to really understanding the chemistry of elec- trothermal atomisation.However, the most recurrent theme must have been the quest for isothermality. This was highligh- ted in E. Lundberg’s keynote presenta- tion where the performance improve- ments provided by spatial and temporal isothermality were emphasised. Further evidence for this was provided by M. T. C. de Loos-Vollebregt. The importance attached to temporal isothermality was also seen in several papers on improved matrix modifiers (palladium continues to be in vogue). Improved furnaces provid- ing spatial and temporal near-isothermal conditions will hopefully be available in the future, and they should show signifi- ETA-AAS, FAAS, AFS, ICP-AES, Delegates enjoying the barbecuelpicnic at Fort York cant performance improvements.How- ever, it is this author’s opinion that their well defined temperature characteristics will also enable more rapid advances in fundamental work, leading to an increased understanding of graphite fur- nace chemistry. Predictably, ICP-AES had the most papers with about 60 presentations (although about half of these were in other sessions such as sample introduc- tion). Keynote presentations on fun- damental studies were given by M. W. Blades and P. E. Walters. The former showed how the development of spectral simulation software can be useful for wavelength selection. There was strong emphasis on the direct analysis of solids, introduced either by the nebulisation of slurries or on a probe (seven papers). L. Ebdon gave an overview of some of his recent successful applications of slurry nebulisation.Sample introduction was also discussed by B. L. Huang, who described some recent advances in the hydride generation technique. Applica- tions in the area of human health and environmental protection were given by S. Caroli. The other invited paper (Z. Zhang) presented a study of the effect of viewing height in the plasma on matrix effects. Most submitted papers were about evenly divided between fundamen- tal studies and applications. Several of the instrumentation papers, particularly from G. Horlick’s group, described Fourier transform systems. There were two invited papers on ICP-MS. Recent research on improving the analytical capabilities and basic understanding of this technique was described by R.S. Houk. Included were attenuation of interfering polyatomic ions by collision processes, liquid chromatography for removing metal oxide interferents and metal speciation, improved sample intro- duction and the fundamental causes of ionisation interference. The other key- note presentation was on applications of ICP-MS in marine analytical chemistry by J. W. McLaren. The analysis of marine reference samples produced by the National Research Council of Canada was described. The methods of isotope dilu- tion and internal standardisation were used. In total, there were 27 papers on ICP-MS, and most were about interfer- ence studies and applications. As this technique gains maturity, there is now interest in alternate sample introduction techniques (one paper on laser ablation and one on electrothermal atomisation).The areas described above comprised most of the programme, but there was also interest in laser spectroscopy, espe- cially laser excited atomic fluorescence where “femtogram” has become a buzz- word. The exciting capabilities of this technique were presented by R. G. Michel, who showed the excellent sensi- tivity which can be achieved. Unfortu- nately, instrument cost continues to be a major deterrent. Flame AAS was not much in evidence, suggesting it is now “played out.’, (However, wasn’t that said about ETA-AAS a few years ago?). No report of a CSI would be complete without reference to the social pro- gramme. The organisers had the unenvi- able task of following the Amsterdam and Garmisch meetings, but they did so suc- cessfully.Most people seem to have more vivid memories of the social than the scientific programme at CSI meetings, and the Toronto meeting is unlikely to be an exception. Monday’s visit to the Ontario Science Center, with its unique working models, showed that science canJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 653 be fun after all. However, the most memorable event may have been Tuesday evening when delegates consumed seem- ingly limitless amounts of alcoholic ref- reshment 1800 ft up Toronto’s CN Tower. The banquet (Thursday) was less formal than usual, taking the form of a barbecue/ picnic at historic Fort York. The tours organised for the Wednesday free day were to Niagara Falls, Canada’s Wonder- land (an amusement park where Eric Lundberg bought a hat-more about that later), the Toronto Zoo and the Stratford Festival.Many delegates who remained for the post-CSI symposia had a second free day on Saturday. Several, including the author, took advantage of this to enjoy the many moods of Lake Ontario. A local boatowner was foolhardy enough to rent out two 25-ft sailboats to a mostly inexperienced and naive crew. Initially the Lake was in its most benevolent mood, and it remained so until we were a good distance from the land. In my boat, everything went well until Eric Lund- berg’s hat blew off. Then the lake assumed a malevolent mood with a thun- derstorm and winds that broke our jib halyard, but fortuitously propelled us in the right direction (i.e., back towards the shore). I believe the other boat fared better, but they had the advantage of a veteran sailor in Jim Holcombe.The successful organisation of the XXV CSI was a joint effort between Canada and the US. However, credit for the success of the meeting should extend to the participants from all countries who showed that international barriers do not exist in the scientific world. That is what the CSI is all about. Now we must eagerly await the XXVI CSI in Bulgaria. Kenneth W. Jackson University of Sas katche wan, Saskatoon, Canada ICP-MS Post-CSI XXV Symposium: 28th-30th June, 1987, Muskoka Sands, Gravenhurst, Canada There was undoubtedly a sense of opti- mism in the air at this Post-CSI sympo- sium, sponsored by The Spectroscopy Society of Canada, and held at a pictur- esque conference centre located on the shores of Lake Muskoka.Even the initial prospect of going on a lake cruise by bus did not appear to affect the excogitation of the participants. However, we eventu- ally found ourselves on board RMS Seg- wun enjoying a Sunday evening dinner in the sun, courtesy of Perkin-Elmer SCIEX. A great deal of mixing was achieved. The symposium itself, which was “sold out” having attracted over 100 partici- pants, was split into three distinct parts. Monday morning brought us six invited lectures by scientists at the forefront in the development of ICP-MS. Gary Hor- lick (University of Alberta) provided an overview of the effect of operating parameters such as nebuliser flow-rate, power and sampling depth on analyte response in ICP-MS. The concept of “parameter families ,” increasingly encountered in ICP-MS lectures, was used to illustrate trends in results drawn from a wide ranging and systematic study of optimisation.Alan Gray (University of Surrey) reported on recent developments at Surrey, interspersing technical discus- sion with enlightening comments on the problems of laboratory and information management using ICP-MS. Amongst the various topics reviewed were the selection of compromise parameter settings and the measurement of plasma potential and its’ correlation with ion energies. George Vickers (Indiana University) described the characteristics of an ICP-MS system with a vertical geometry and commented on the benefits of water cooling the spray chamber and the effects of generator frequency in detection limits and back- ground spectral features.Don Douglas (SCIEX) presented details of a study of the effect of salt deposition on the sampling orifice by monitoring the interface pressure as a function of time. Other interference effects were found to depend variously on Chris Riddle und Jim McLuren (centre) relaxing with delegates at the Boat House at Lake Muskoka mass, ICP conditions and ion optics parameters. It was concluded that the addition of a matrix changes the total ion current and alters the focal properties, thus affecting analyte response. Sam Houk (Iowa State University) also con- sidered interference effects in light and heavy matrices, and illustrated these for different skimmer geometries and cylinder potentials. Looking to the future, some of the advantages of the Daly detector were discussed, and some specu- lation was offered on the design of mass spectrometers for ICP-MS, particularly in regard to resolution. Jean-Michel Mer- met (University Claude Bernard) des- cribed an investigation of the levels of oxides observed in ICP-MS, and con- cluded that the problem was one of dissociation rather than recombination.It was suggested that the use of a sheath gas to improve energy transfer and hence dissociation was beneficial, but shifted zones in the plasma towards the injector. A poster session was organised for the afternoon, and 23 contributions were presented including applications in clin- ical, geological, nuclear, agricultural and environmental areas. Whilst the invited lecturers set the tone of the meeting, in terms of the current state of the art, the poster session allowed participants to engage in informal discussion of the prac- tical details of the technique, in a way which was sadly lacking at the main CSI meeting.The exchange of ideas and opinions continued well into the evening, receiving sustenance from a lakeside bar- becue sponsored by VG Isotopes. The final session on Tuesday morning consisted of chaired discussion groups on: Calibration Strategies for ICP-MS (J. McLaren), Fundamentals of Fluid Dynamics (B. French) and Isotope Ratio Measurements (D. Douglas). After- wards, the invited lecturers formed a panel to answer questions submitted by participants. In view of the many con- troversies surrounding ICP-MS in recent654 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY7 OCTOBER 1987, VOL.2 years, there was surprising unanimity on research. The clear message from this Chris Riddle, who were warmly thanked the panel regarding the performance of meeting was that the technique (rather at the close. Submitted papers from the current commercially available equip- than a particular denomination of instru- meeting will be published in the February ment. Developments in the technique will ment) is proven, and it is up to practition- 1988 issue of JAAS. come from a more detailed understanding ers to continue to demonstrate the fact. John Marshall of processes occurring in the ion optics, The success of the meeting owed a great ICI Wilton Materials Centre and is undoubtedly an area for future deal to the efforts of Jim McLaren and Middlesbrough, UK Graphite Furnace Post-CSI XXV Symposium: 28th June-2nd July, 1987, Huntsville, Ontario, Canada This small symposium (about 60 atten- dees) consisted largely of graphite furnace “enthusiasts.” The mix of 24 formal invited presentations, three less formal panel discussions and informal social inter- actions provided an excellent forum for the interchange of experiences and ideas. Such was the quality of the papers that this author was tempted to review every one of them.However, in the interest of brevity attempts will be made instead to identify the most important themes. To me, the strongest theme was the importance of controlled furnace heating characteristics, which is doubtless the major factor in making graphite furnace AAS a reliable analytical technique. The necessity for temporal near-isothermality was emphasised by W, Slavin, who illus- trated the reproducibility of characteristic mass values afforded by the stabilised temperature platform furnace technique.This is now sufficient for characteristic masses to be used as parameters for testing the performance of furnaces. Fur- nace designs providing spatial near- isothermality were then shown by W. Frech to provide significant performance improvements over current commercial systems. In evaluating a mathematical model to represent the temporal shape of absorbance signals, B. Welz examined both temporal and spatial temperature non-uniformity . As expected at a meeting such as this, many of the papers were of a fundamental nature.They included studies of atomisa- tion efficiency (C. Rademeyer and H. Falk), sources of noise in ETA-AAS (J. Harnly), the role of released oxidants in atomisation processes (R. Sturgeon), pre- atomisation mechanisms (G. Rayson) and the influence of pressure on absorbance (R. Lovett). The spatial distribution of atoms in the furnace tube was examined by J. Holcombe, who used a time-gated Schlieren technique. Systematically changing operating parameters (e.g., temperature) was shown by W. Wend1 to be a useful means of investigating the chemistry of electrothermal atomisation. The excellent characteristics of palla- dium as a matrix modifier were the subject of several papers. Studies on release mechanisms of analytes in the presence of palladium were presented by T.Rettburg and D. Styris. The latter showed, through mass spectrometric stu- dies, that extremely complex chemical interactions may occur when palladium is used to modify selenium. The direct analysis of solids attracted a lot of interest, papers being presented by U. Kurfurst, N. Miller-Ihli and K. Jack- son. This was then the subject of a very lively evening panel discussion when the relative merits of directly weighing solids into the furnace and pipetting them as slurries were heatedly debated (aided no doubt by the complimentary beverages provided by the organisers). Alternative graphite furnace tech- niques such as FANES and laser-excited AFS continue to attract attention, and several of these were discussed by K. Dittrich. Other noteworthy presentations included a discussion of Zeeman AAS (M.de Loos-Vollebregt), the combined use of a furnace and flame for volatilisa- tion studies (T. Kantor), computerised signal processing (H. Berndt), automated standard additions (J. Sotcra), jet-en- hanced cathodic sputtering (E. Piepmeier and C. Chakrabarti) and graphite probe atomisation (A. Brown). The participants’ dedication to science was severely tested by the location of this meeting, a resort hotel in a beautiful part of northern Ontario. Many were the temptations to sneak out early and lan- guish on the lake. The analytical spectros- copists’ amazing affinity for water (see the CSI report in this issue) was again seen with numerous swimming, sailing and windsurfing escapades. Any serious accidents were averted by the activities of the rescue boat which brought a number of aspirant windsurfers back from the far reaches of the lake (no names mentioned, but see below).Candid photographs were obtained by the Editor of JAAS, who will sell the negatives if the price is right. Scientifically, this symposium was excellent, and there should be no doubt in the minds of any of the attendees that research in ETA-AAS is active and thriv- ing. Meetings such as this one are highly instrumental in bringing the technique further into maturity. Special thanks are due to Jim Holcombe and Ralph Sturgeon for its organisation. It was indeed fortu- nate that their organisational skills far outweighed their windsurfing abilities. Kenneth W. Jackson University of Saskatchewan, Saskatoon, Canada 2nd Surrey Conference on Plasma Source Mass Spectrometry: 6th-8th July, 1987, University of Surrey, Guildford, UK For the second time, the Department of Chemistry, University of Surrey, hosted the conference on Plasma Source Mass Spectrometry.Over 80 delegates atten- ded, approximately one quarter of whom came from outside the UK. Those who attended included both users and poten- tial users of inductively coupled plasma mass spectrometry (ICP-MS) . Accommo- dation was provided in the University halls of residence and most participants stayed on site. Dr. Alan Gray opened the conference. After welcoming delegates to Surrey, Dr. Gray passed on greetings to the confer- ence from Dr. Alan Date, who sadly was too ill to attend. [The latest news is that Alan Date is making steady progress and is feeling much better.Editor.] The scientific programme covered three broad areas of interest: applications of ICP-MS, ICP-MS basics-a short course, and developments in plasma source mass spectrometry. Additionally, a poster session was arranged for the latter part of the meeting. The format for oral presentations consisted of both invited and contributed papers. The first invited paper was given by G. Price-Russ (Lawrence Livermore National Laboratory, CA, USA) who reviewed the progress made by himself and co-workers in evaluating and improv- ing the techniques of ICP-MS. In par- ticular he referred to the determination of uranium isotopes and the hardware and software factors which improve or limit the precision of isotope ratio measure- ments.Contributed papers were presen- ted dealing with a wide range of applica- tions: the measurement of total lead in blood and the use of isotope ratioJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 655 measurements (where better than 1% precision was needed and achieved) to determine the source of blood lead (H. T. Delves, Southampton General Hospital, UK); studies of cadmium and arsenic speciation in foodstuffs using chromato- graphic techniques directly coupled to ICP-MS (H. M. Crews, MAFF, Norwich, UK) and the theory and application of isotope dilution analysis for the deter- mination of rhenium and platinum in catalysts (A. A. van Heuzen, Shell Research, Amsterdam, The Nether- lands). Papers by P. S. Ridout (Institute of Oceanographic Sciences, Wormley , UK), A.S. Clarkson (British Nuclear Fuels, Preston, UK) and C. T. Tye (VG Elemental, Winsford, UK) described the use of ICP-MS in the multi-element analy- sis of marine animals to obtain base-line data for use in coastal pollution studies, the measurement of uranic materials for impurities and the analysis of high dissol- ved solids samples, respectively. In an invited paper, N. T. Ward (University of Surrey, UK) compared neutron activa- tion analysis with ICP-MS and highlighted the high sensitivity, fast data acquisition and linear dynamic range of ICP-MS. The short course in ICP-MS basics comprised four 45-minute presentations by experts in various fields. An excellent review of the use of plasmas as sources for mass spectrometry was given by J.M. Mermet (Universite Claude Bernard- Lyon, France). The theory behind plasma potential and its practical manifestations were discussed by A. L. Gray (University of Surrey, UK) whilst C. Smith (VG Masslab, Winsford, UK) elucidated some of the mysteries of the quadrupole mass analyser. Finally, considerations for data acquisition and processing were presen- ted by G. Price-Russ. As an ICP-MS user, I found these presentations very informa- tive. Feedback from other participants, both users and non-users, indicated that the “short course” was well received. Various aspects of the design and oper- ation of plasma source mass spectromet- ers were discussed by speakers in the second half of the meeting. The causes of matrix effects in ICP-MS were described by A.Boorn (Perkin-Elmer SCIEX, Thornhill, Canada). Work had been car- ried out with an ELAN ICP-MS in which the matrix effects were strongly influen- ced by ion optics settings. One explana- tion involved space charge effects, a theory supported by computer simulation studies of ion trajectories. J. M. Mermet’s invited lecture dealt with the influence of ICP design and operation (with particular reference to an ICP-MS prototype deve- loped at the Lyon laboratory in conjunc- tion with the NERMAG company) on the formation of some molecular species in ICP-MS. The reduction of polyatomic ions by optimising spray chamber design (water cooled), cone/skimmer configura- tion and mass flow control was described by J. G. Williams (University of Surrey, UK).The advantages and disadvantages of helium source plasmas for MS were described and developments with a VG PlasmaQuad using a microwave induced helium plasma (P. G. Brown, University of Cincinnati, USA) or a helium ICP (D. W. Koppenaal, University of Texas, USA) were reported. J. G. Gordon (VG Elemental, Winsford, UK) presented data from laser ablation ICP-MS studies. Nineteen posters were displayed during the poster session covering a range of topics including pre-concentration of rare earth elements from geological materials by ion exchange and sample dissolution using microwave digestion bombs prior to ICP-MS (K. E. Jarvis, University of Surrey, UK); the determination of uran- ium and thorium in semiconductor materials (H. Oguro, Matsushita Tech- noresearch, Osaka, Japan) and the measurement of elements in standard rock samples by ICP-MS (T.Ilirata, University of Tokyo and T. Kagaya, Maru burn, Tokyo , Japan). On the first evening of the conference, VG Isotopes hosted an evening “seminar.” This was well attended and much appreciated as the weather was extremely hot and humid. The entire conference was accompanied by very warm weather and thanks must go to Kym Jarvis and John Williams for rapidly supplying iced drinks during tea and coffee breaks. They obviously saw the looks of dismay on the faces of the delegates at registration when only tea and coffee were available. Overall, the conference was a success and provided a useful forum for discus- sion particularly as it followed closely on the heels of the XXV CSI held in Toronto and the Post-CSI ICP-MS Symposium at Muskoka Sands.Some delegates had attended these conferences and a sum- mary of the Muskoka Sands Symposium was provided by J. M. Mermet. Lastly it remains to thank Alan Gray, Kym Jarvis and John Williams for organising the conference. Helen Crews Ministry of Agriculture, Fisheries and Food, Food Science Division, Norwich, UK Spectroscopy Across the Spectrum : Analytical Applications of Spectroscopy, 12th-15th July 1987, Norwich, UK This meeting, held at the University of East Anglia in the historic City of Nor- wich, was jointly organised by the Koyal Society of Chemistry - Analytical Division (East Anglia Region, Atomic Spectro- scopy and Automatic Methods Groups). The meeting was organised to incorporate the first International Committee for Near-Infrared Spectroscopy, the concep- tion of which has been described else- where (Analytical Proceedings, 1987, 24, 133); it also saw the inauguration of the Molecular Spectroscopy Group, under the chairmanship of Professor Alan Townshend. The meeting was arranged into three broad subject areas, combined tech- niques, Fourier transform spectroscopy and data analysis, each of which was represented by well known speakers in the field of atomic spectroscopy. Keynote lectures were presented by Professor Les Ebdon on “Combined High-performance Liquid Chromatography - Atomic Spec- troscopy for Trace Metal Speciation,” Dr. Anne Thorne on “Fourier Transform Atomic Spectroscopy” and Dr. Julian Tyson on “Conventional Calibration Strategies for Flame AAS and some Unconventional Alternatives.” After lunch, delegates were free to wander around the exhibition (24 exhibi- tion stands covering a range of manufac- turers and a book publisher) and poster sessions. The afternoon sessions were divided into parallel sessions, Monday afternoon featuring Atomic Spectro- scopy. Four speakers, Dr. Alistair Brown, Dr. David Littlejohn, Phil Nor- man and Dr. Maryanne Thomsen, gave a balanced programme on sampling, analy- sis and techniques for elemental analysis. Although the meeting was not specific- ally an atomic spectroscopy meeting, interested delegates could avail them- selves of all present and future aspects of “Spectroscopy Across the Spectrum.” John R. Dean Research Fellow, Plymouth Polytechnic at MAFF, Food Science Laboratory, Norwich, UK

ISSN:0267-9477    

DOI:10.1039/JA9870200651

出版商:RSC    

年代:1987

数据来源: RSC

摘要:

656 JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY, OCTOBER 1987, VOL. 2 Book Review Inductively Coupled Plasma Emission Spectroscopy. Part 1: Methodology, Instrumentation, and Performance. Edited by P. W. J. M. Boumans. Pp. xiv + 584, Chemical Analysis, Volume 90. Wiley-Interscience. 1987. Price 271.75. ISBN 0 471 09686 5. With several hundred inductively coupled plasma (ICP) emission spectrometers in regular use in a wide variety of analytical applications throughout the world, there is an obvious demand for a definitive text on this popular technique for elemental analysis. P. W. J. M. Boumans, one of the greatest experts in the field has set him- self, with the aid of other leading practi- tioners, the task of fulfilling this demand. Since the original project for a single volume has expanded into a two-volume treatise, judgement must be suspended as to whether he has succeeded in his task, but this first volume can at least be described as very promising.The extent of Boumans’ personal con- tribution can be assessed by noting that of the nine chapters in this volume, five were written by the Editor himself [Introduc- tion to Atomic Emission Spectrometry (AES), Plasma Sources other than ICPs, ICPs, Basic Concepts and Characteristics of ICP-AES and Line Selection and Spec- tral Interferences]. Boumans also co- authored chapters on torches (with G. M. Hieftje) and sample introduction (with J. A. C. Broekaert). The other two chapters, on “Spectrometers” and “Detection and Measurement,” were written by J. W. Olesik, and H. Bubert and W.-D. Hagenah, respectively.The chapters Boumans has written reflect his authoritative grasp of the field. While readers may wish to argue with the weight offered to some aspects, e.g., the contri- bution of Greenfield to the evolution of ICP-AES as an analytical technique, or the benefits of rigorous optimisation strategies for ICP-AES, they will wel- come the refreshingly critical approach. These chapters show a level of expertise which on their own would justify purchase of the book. The introduction to AES is scholarly yet helpful, glimpses can be seen of the author’s original background in d.c. arc emission. Perhaps the review of other sources will be of less value to the practitioner, including as it does a number of historical curiosities. Chapter 3 intro- duces ICPs in a clear descriptive manner and includes a helpful review of reviews.The chapter on basic concepts and charac- teristics will be a boon to many new users with a wealth of advice based on fun- damental concepts. The review of torch developments will be meaningful for all readers. Given the tremendous interest in sample introduction for ICP-AES, the sixth chapter could usefully have been expanded and possibly updated to give a more critical survey of what is admittedly one of the more lively areas of current research. The treatment of spectral inter- ferences is once again soundly based on theoretical concepts and will be of imme- diate practical value. The chapters on instrumentation complete the volume adequately, although it may yet be the authors will regret not having included more on Fourier transform approaches.In summary this is an excellent volume, which can be strongly recommended to those who are interested in ICP-AES as a practical analytical tool or as a research area. Having read Part 1, this reviewer eagerly awaits Part 2. Les Ebdon Plymouth Polytechnic, UK Edited by L . Edition . Bretherick Safety Consultant m’ Hazards in the Chemical Laboratory has become established -A as an essential handbook of safe6 practices, measures and toxic effects for laboratories handling dangerous chemicals. Since the last edition was Dublished in 1981 there have been \ many changes in legishion, regulations, precautionary safety methods and toxicity assessments which warrant publication of this new 4th edition. In addition coverage has been expanded to include material relating to legislation and safety practices in the USA. Protective PVC Binding 618pp Price f 29.50 ($54.00) ISBN 0 85186 489 9 RSC Members Price f 18.00 ORDERING RSC Members should send their orders to: The Royal / . ROYAL Society of Chemistry, Membership Manager, 30 Russell Square, SOCIETY OF London WClB 5DT, UK. Non-RSC Members should send their orders ff 8 CHEMlSTRY +$ FJ;nFl;ion to: The Royal Society of Chemistry, Distribution Centre, Blackhorse Road, Letchworth, Herts SG6 lHN, UK.

ISSN:0267-9477    

DOI:10.1039/JA9870200656

出版商:RSC    

年代:1987

数据来源: RSC