Journal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates) JAAS Editorial Board* Chairman B. L. Sharp (Loughborough UK) J. Egan (Cambridge UK) D. A. Hickman (London UK) J. Marshall (Middlesbrough UK) J. M. Mermet (Villeurbanne France) D. L. Miles (Keyworth UK) R. D. Snook (Manchester UK) *The JAAS Editorial Board reports to the Analytical Editorial Board Chairman A. G. Fogg (Loughborough UK) JAAS Advisory Board F. C. Adams (Antwerp Belgium) R. M. Barnes (Amherst MA USA) L. Bezur (Budapest Hungary) R. F. Browner (Arlanta GA USA) S . Caroli (Rome Italy) A. J. Curtius (Rio de Janeiro Brazil) L. de Galan (Vlaardingen The Netherlands) J. B. Dawson (Leeds UK) K. Dittrich (Leipzig Germany) W . Frech (UmeB Sweden) K. Fuwa (Tokyo Japan) A. L. Gray (Egham UK) S.Greenfield (Loughborough UK) G. M. Hieftje (BlUOmingtOn IN USA) G. Horlick (Edmonton Canada) B. V. L'vov (Leningrad USSR) Ni Zhe-ming (Beijing China) N. Omenetto (lspra Italy) T. C . Rains (Charleston SC USA) 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 "D L J Armstrong (Dumfries UK) J R Bacon (Aberdeen UK) C Barnard (Glasgow UK) R M Barnes (Amherst MA USA) S Branch (High Wycombe UK) R Bye (Oslo Norway) J Carroll (Middlesbrough UK) M R Cave (Keyworth UK) "J M Cook (Keyworth UK) "M S Cresser (Aberdeen UK) H M Crews(Norwich UK) J S Crighton (Sunbury-on-Thames UK) J R Dean (Newcastle upon Tyne UK) "J B Dawson (Leeds UK) "J Egan (Cambridge UK) "A T Ellis (Oxford UK) J Fazakas (Bucharest Romania) D J Halls (Glasgow UK) "D A Hickman (London UK) "S J Hill (Plymouth UK) K W Jackson (Albany NY USA) R Jowitt (Middlesbrough UK) K Kitagawa (Nagoya Japan) J Kubova (Bratislava Czechoslovakia) "D Littlejohn (Glasgow UK) "J Marshall (Middlesbrough UK) Miles (Keyworth UK) H.Matusiewicz (Poznan Poland) J. M. Mermet (Wlleurbanne France) R. G. Michel (Storrs CT USA) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beijing China) P. R. Poole (Hamilton New Zealand W. J. Price (Ashburton UK) C. J. Rademeyer (Pretoria South Africa) M . H. Ramsey (London UK) A. Sanz-Medel (Oviedo Spain) "B. L. Sharp (Loughborough UK) I. L. Shuttler (Uberlingen FRG) S. T. Sparkes (Plymouth UK) R. Stephens (Halifax Canada) J.Stupar (Ljubljana Yugoslavia) R . E. Sturgeon (Ottawa Canada) A. P. Thorne (London UK) G. C. Turk (Gaithersburg MD USA) J. F. Tyson (Amherst MA USA) "A. M. Ure (Aberdeen UK) S. J. Walton (Crawley UK) P. Watkins (London UK) B. Welz (Uberlingen FRG) J. Williams (fgham UK) J. B. Willis (Victoria Australia) "A. Taylor (Guildford UK) "Members of the ASU Executive Committee Editor JAAS Judith Egan The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK Telex No 81 8293 Fax 0223 423623 Assistant Editors Brenda Holliday €ditorial Secretary Monique Warner US Associate Editor JAAS Dr J. M Harnly US Department of Agriculture Beltsville Human Nutriton Research Center Beltsville MD 20705 USA Telephone 301 -344-2569 Telephone 0223 420066 BLDG 161 BARC-EAST Paula O'Riordan Sheryl Whitewood Advertisements Advertisement Department The Royal Society of Chemistry Burlington House Piccadilly London WIV OBN UK Telephone 071-437 8656.Fax 071-437 8883 Information for Authors Full details of how to submit materials for publica- tion in JAAS are given in the Instructions to Authors in Issue 1 Separate copies are available on request The Journal of Analytical Atomic Spectrometry (JAAS) is an international journal for the publica- tion of original research papers communications and letters concerned with the development and analytical application of atomic spectrometric techniques The journal is published eight times a year including comprehensive reviews of specific topics of interest to practising atomic spectrosco- pists and incorporates the literature reviews which were previously published in Annual Reports on Analytical Atomic Spectroscopy (ARAAS) Manuscripts intended for publication must de- scribe original work related to atomic spectromet- ric analysis Papers on all aspects of the subject will be accepted including fundamental studies novel instrument developments and practical ana- lytical applications As well as AAS AES and AFS papers will be welcomed on atomic mass spectro- metry and X-ray fluorescence/emission spectro- metry Papers describing the measurement of molecular species where these relate to the char- acterization of sources normally used for the pro- duction of atoms or are concerned for example with indirect methods of analysis will also be ac- ceptable for publication Papers describing the de- velopment and applications of hybrid techniques (e g GC-coupled AAS and HPLC-ICP) w\\\ be par- ticularly welcome Manuscripts on other subjects of direct interest to atomic spectroscopists in- cluding sample preparation and dissolution and analyte pre-concentration procedures as well as the statistical interpretation and use of atomic spectrometric data will also be acceptable for pub- lication There is no page charge The following types of papers will be consid- ered full papers describing original work Communications which must be on an urgent matter and be of obvious scientific importance Communications receive priority and are usually published within 2-3 months of receipt They are intended for brief descriptions of work that has progressed to a stage at which it is likely to be valuable to workers faced with similar problems Reviews which must be a critical evaluation of the existing state of knowledge on a particular facet of analytical 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 elsewhere except by permission Submission of a manu- script will be regarded as an undertaking that the same material is not being considered for publica- tion by another journal Manuscripts (three copies typed in double spacing) should be sent to Judith Egan Editor JAAS or Dr J M Harnly US Associate Editor JAAS All queries relating to the presentation and sub- mission of papers and any correspondence re- garding accepted papers and proofs should be directed to the Editor or US Editor (addresses as above) Members of the JAAS Editorial Board (who may be contacted directly or via the Editorial Office) would welcome comments suggestions and advice on general policy matters concerning JAA S Fifty reprints are supplied free of charge Journal of Analytical Atomic Spectrometry (JAAS) (ISSN 0267-9477) is published eight times a year by The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK All orders accompanied with payment should be sent directly to The Royal Society of Chemistry Turpin Tractions Ltd Blackhorse Road Letchworth Herts SG6 1 HN UK Tel +44 (0) 462 672555 Telex 825372 Turpin G Fax +44 (0) 462 480947 Turpin Transactions Ltd is wholly owned by Thd Royal Society of Chemistry 1991 Annual subscription rate EC f309 00 USA $728 00 Rest of World €355 00 Customers should make payments by cheque in sterling payable on a UK clearing bank or in US dollars payable on a US clearing bank Air freight and mailing in the USA by Publications Expediting Inc 200 Meacham Avenue Elmont NY 11003 USA Postmaster send address changes to Journal of Analyrical Atomic Spectrometry (JAAS) Publications Expediting Inc 200 Meacham Avenue Elmont NY 11 003 Second class postage paid a t 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 1991 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 publishersJournal of Analytical Atomic Spectrometry (Including Atomic Spectrometry Updates) JAAS Editorial Board* Chairman B L Sharp (Loughborough UK) J.Egan (Cambridge UK) D A. Hickman (London UK) J. Marshall (Middlesbrough UK) J. M. Mermet (Wleurbanne France) D. L. Miles (Keyworth UK) R. D. Snook (Manchester UK) *The JAAS Editorial Board reports to the Analytical Editorial Board Chairman A. G. Fogg (Loughborough UK) JAAS Advisory Board F C Adams (Antwerp Belgium) R M Barnes (Amherst MA USA) G M Hieftje (Bloomington IN USA) L Bezur (Budapest Hungary) G Horlick (Edmonton Canada) R F Browner (Atlanta GA USA) S Caroli (Rome Italy) A J Curtius (Rio de Janeiro Brazid L de Galan (Vlaardingen The Netherlands) J B Dawson (Leeds UK) R E Sturgeon (Ottawa Canada) K Dittrich (Leipzig Germany) W Frech (Umed Sweden) K Fuwa (Tokyo Japan) A L Gray (Egham UK) S Greenfield (Loughborough UK) B V L'vov (Leningrad USSR) Ni Zhe-ming (Belling China) N Omenetto (lspra Italy) T C Rains (Charleston SC USA) 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 "D L J Armstrong (Dumfries UK) J R Bacon (Aberdeen UK) C Barnard (Glasgow UK) R M Barnes (Amherst MA USA) S Branch (High Wycombe UK) R Bye (Oslo Norway) J Carroll (Middlesbrough UK) M R Cave (Keyworth UK) *J M Cook (Keyworth UK) "M S Cresser (Aberdeen UK) H M Crews (Norwich UK) J S Crighton (Sunbury-on-Thames UK) J R Dean (Newcastle upon Tyne UK) *J B Dawson (Leeds UKI *J Egan (Cambridge UK) "A T Ellis (Oxford UK) J Fazakas (Bucharest Romania) D J Halls (Glasgow UK) *D A Hickman (London UK) "S J Hill (Plymouth UK) K W Jackson (Albany NY USA) R Jowitt (Middlesbrough UK) K Kitagawa (Nagoya Japan) J Kubova (Bratislava Czechoslovakia) "D Littlejohn (Glasgow UK) "J Marshall (Middlesbrough UK) Miles (Keyworth UK) H.Matusiewicz (Poznan Poland J. M. Mermet (Villeurbanne France) R. G. Michel (Storrs CT USA) T. Nakahara (Osaka Japan) Ni Zhe-ming (Beijing China) P.R. Poole (Hamilton New Zealand W. J. Price (Ashburton UK) C. J. Rademeyer (Pretoria South Africa) M. H. Ramsey (London UK) A. Sanz-Medel (Oviedo Spain) "B. L. Sharp (Loughborough UK) I. L. Shuttler (Uberlingen FRG) S. T. Sparkes (Plymouth UK) R. Stephens (Halifax Canada) J. Stupar (Ljubljana Yugoskwia) R. E. Sturgeon (Ottawa Canada) A. P. Thorne (London UK) G. C. Turk (Gaithersburg MD USA) J. F. Tyson (Amherst MA USA) *A. M . Ure (Aberdeen UK) S . J. Walton (Crawley UK) P. Watkins (London UK) B. Welz (Uberlmgen FRG). J. Williams (Egham UK) J. B. Willis (Victoria Australia) *A. Taylor (Guildford UK) *Members of the ASU Executive Committee Editor JAAS Judith Egan The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF UK Telex No 818293 Fax 0223 423623 Beltsville MD 20705 USA Assistant Editors Brenda Holliday Editorial Secretary Monique Warner US Associate Editor JAAS Dr J M Harnly US Department of Agriculture Beltsville Human Nutriton Research Center Telephone 0223 420066 BLDG 161 BARC-EAST Telephone 301 -344-2569 Paula O'Riordan Sheryl Whitewood Advertisements Advertisement Department The Royal Society of Chemistry Burlington House Piccadilly London W I V OBN UK. Telephone 071-437 8656.Fax 071-437 8883 Information for Authors Full details of how to submit materials for publica- tion in JAAS are given in the Instructions to Authors in Issue 1. Separate copies are available on request. The Journal of Analytical Atomic Spectrometry (JAAS) is an international journal for the publica- tion of original research papers communications and letters concerned with the development and analytical application of atomic spectrometric techniques The journal is published eight times a year including comprehensive reviews of specific topics of interest to practising atomic spectrosco- pists and incorporates the literature reviews which were previously published in Annual Reports on Analytical Atomic Spectroscopy (ARAAS) Manuscripts intended for publication must de- scribe original work related to atomic spectromet- ric analysis Papers on all aspects of the subject will be accepted including fundamental studies novel instrument developments and practical ana- lytical applications As well as AAS.AES and AFS papers will be welcomed on atomic mass spec- trometry and X-ray fluorescence/emission spec- trometry Papers describing the measurement of molecular species where these relate to the char- acterization of sources normally used for the pro- duction of atoms or are concerned for example with indirect methods of analysls will also be ac- ceptable for publication Papers describing the de- velopment and applications of hybrid techniques (e g GC-coupled AAS and HPLC-ICP) will be par- ticularly welcome Manuscripts on other subjects of direct interest to atomic spectroscopists in- cluding sample preparation and dissolution and analyte pre-concentration procedures as well as the statistical interpretation and use of atomic spectrometric data will also be acceptable for pub- lication There is no page charge The following types of papers will be consid- ered full papers describing original work Communicabons which must be on an urgent matter and be of obvious scientific importance Communications receive priority and are usually published within 2-3 months of receipt They are intended for brief descriptions of work that has -progressed to a stage at which it is likely to be valuable to workers faced with similar problems Reviews which must be a critical evaluation of the existing state of knowledge on a particular facet of analytical 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 elsewhere except by permission Submission of a manu- script will be regarded as an undertaking that the same material is not being considered for publica- tion by another journal Manuscripts (three copies typed in double spacing) should be sent tb Judith Egan Editor JAAS or Dr J M Harnly US Associate Editor JAAS All queries relating to the presentation and sub- mission of papers and any correspondence re- garding accepted papers and proofs should be directed to the Editor or IJS Editor (addresses as above) Members of the JAAS Editorial Board (who may be contacted directly or via the Editorial Office) would welcome comments suggestions and advice on general policy matters concerning JAAS Fifty reprints are supplied free of charge.Journal of Analytical Atomic Spectrometry IJAAS) (ISSN 0267-9477) is published eight times a year by The Royal Society of Chemistry Thomas Graham House Science Park Milton Road Cambridge CB4 4WF.UK. All orders accompanied with payment should be sent directly to The Royal Society of Chemistry Turpin Tractions Ltd. Blackhorse Road Letchworth Herts. SG6 1 HN UK Tel. +44 (0) 462 672555; Telex 825372 Turpin G; Fax +44 (0) 462 480947. Turpin Transactions Ltd. is wholly owned by The Royal Society of Chemistry. 1991 Annual subscription rate EC f309.00 USA $728.00 Rest of World f355.00. Customers should make payments by cheque in sterling payable on a UK clearing bank or in US dollars payable on a US clearing bank. Air freight and mailing in the USA by Publications Expediting Inc. 200 Meacham Avenue Elmont NY 11 003. USA Postmaster send address changes to Journal of Analytical Atomic Spectrometry IJAASI Publications Expediting Inc. 200 Meacham Avenue Elmont NY 11 003. 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 1991. All rights reserved. No pact 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 permissiori of the publishers.