摘要:

May 1985 ANPRDI 22(5) 125-156 (1985) ISSN 0144-557X Hon. Treasurer Analytical Proceedings Proceedings of The Analytical Division of The Royal Society of Chemistry Analytical Division Officers: D. C. M. Squirrel1 President P. G. W. Cobb Hon. Secretary R. Sawyer Hon. Publicity and Public Relations Officer Dr. J. F. Tyson, Department of Chemistry, Loughborough University of Technology, Loughborough, Leicestershire LE11 3TU Assistant Editor Ms. D. Chevin A. M. Ure *P. C. Weston "Exofficio members Hon. Assistant Secretary D. I. Coomber, O.B.E. Analytical Division Secretary Miss P. E. Hutchinson Editor, The Analyst and Analytical Proceedings P. C. Weston Senior Assistant Editors Mrs. J. Brew, R. A. Young Publication of Analytical Proceedings is the responsibility of the Analytical Editorial Board: *P.M. Maitlis A. C. Moffat J. M. Ottaway (Chairman) L. S. Bark L. C. Ebdon A. G. Fogg B. L. Sharp J. D. R. Thomas All editorial matter should be addressed to The Editor, Analytical Proceedings, The Royal Society of Chemistry, Burlington House, London W1V OBN. Telephone 01 -734 9864. Telex 268001. Analytical Proceedings (ISSN 0144-557x3 is published monthly by The Royal Society of Chemistry, Burlington House, London W1V OBN, England. All orders, accompanied by payment, should be sent to The Royal Society of Chemistry, The Distribution Centre, Blackhorse Road, Letchworth, Herts. SG6 IHN, England. 1985 Annual Subscription price if purchased on its own: UK f63.50, Rest of World f67.00, US $123.00, including air speeded delivery.Air freight and mailing in the USA by Publications Expediting Inc., 200 Meacham Avenue, Elmont, N.Y. 11003. USA Postmaster: Send address changes to: Analytical Proceedings, Publications Expediting Inc., 200 Meacham Avenue, Elmont, N.Y. 11003. Second class postage paid at Jamaica, N.Y. 11431. All other despatches outside the UK by Bulk Airmail within Europe, Accelerated Surface Post outside Europe. PRINTED IN THE UK. @ The Royal Society of Chemistry 1985. 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.Annual Reports on Analytical Atomic Spectroscopy Vol. 13 Edited by K. W. Jackson and L. Ebdon This volume reports on current developments in all branches of analytical atomic emission, absorption and fluorescence spectroscopy with reference to papers published and lectures presented during 1983. Much of the information is in tabular form for ease of reference. Brief Contents: Atomization and Excitation; Instrumentation; Methodology; Applications; Reviews; References; Author and Subject Index. Hardcover 427pp 0 85186 687 5 Price €55.00 ($99.00) ORDERING: RSC Members should send their orders to: The Royal Society of Chemistry, Membership Officer, 30 Russell Square, London WC1 B 5DT. Non-RSC Members should send their orders to: The Royal Society of Chemistry, Distribution Centre, Letchworth, Herts SG6 1HN.The Royal Society of Chemistry Burlingtori House London W1V OBN Molecular Aspects of Toxicology by D. E. Hathway In such a fragmented field as toxicology with so many diverse practices and specialisms, it is hard to gain an idea of continuity. This book attempts to unify the subject of toxicology and should be useful to chemists engaged in molecular biology and workers concerned with toxicology and cancer research in particular, as well as to pharmacologists and specialists in drug development and occupational hygiene and medicine in general. Brief Contents: Part I Toxicity of Foreign Compounds Assessment of Toxic Risk; Structure-Activity Considerations; Measurement of a Carcinogenic Exposure; Part II Relation between Dose and Effect and Time Biological Action; Extension of Simple Theory to Toxicology; Part 111 Metabolism Metabolic Pathways for Industrial Chemicals and Pesticides; Kinetic Considerations; Part IV Pharmacogenetics Species Differences in Metabolism and Tox ic i t y ; Part V Biochemical Lesions Mode of Action Studies; Part VI Chemical Carcinogenesis Importance of Chemical Non-enzymic Reactions In Vivo; Possible Mechanisms of Carcinogenesis and their Biological Significance; Host Factors and Cellular Aspects; Tissue Specificity; Part VII Toxicant Allergy Antigen Formation and lmmunobiological Effects Produced by Foreign Compounds Hardcover 319pp 0 85186 068 0 Price f27.50 ($50.00) RSC Members f19.00 Index of Chemistry Films 1984 Compiled by J.S. Clarke Index of Chemistry Films 1984 consists of a comprehensive list of films, filmstrips, filmloops, videotapes, slides, soundtapes and overhead transparencies dealing with chemistry and related subjects. Each entry includes the following information: Title; Date of publication; Black and white or colour; Sound or silent; Running time; Gauge; Free loan or hire; Brief contents; Film sponsor; Distributor. The contents of this new book are as follows: Notes for Guidance; Subject Categories; Classified Index. Part I Physical Chemistry; Part 2 Inorganic Chemistry; Part 3 Organic Chemistry; Part 4 Energy; Part 5 Biochemical Topics; Part 6 Applied Chemistry; Part 7 Miscellaneous Topics. Alphabetical Index; Appendix 1 : Late Entries to Classified Index; Appendix 2: Items too late for Classified; and Alphabetical Indices; Addresses of Distributors Softcover 480pp 0 85186 499 6 Price f19.00 ($34.00) RSC Members f12.50 ORDERING: RSC Members should send their orders to: The Royal Society of Chemistry, Membership Officer, 30 Russell Square, London WCIB 5DT. Non-RSC Members should send their orders to: The Royal Society of Chemistry, Distribution Centre, Blackhorse Road, Letchworth, Herts SG6 IHN. The Royal Society of Chemistr Burlington House London W1V OBN

ISSN:0144-557X    

DOI:10.1039/AP98522FX017

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

ANPRDI 22(5) 125-156 (1985) May 1985 Analytical Proceedings Proceedings of the Analytical Division of The Royal Society of Chemistry CONTENTS 125 Editorial 125 Annual General Meeting of the Analytical Division 126 Reports of Meetings 126 Analytical Division Distinguished Service Award 128 Analytical Methods Committee: Evaluation of Analytical Instrumentation. Part II. Atomic-absorption Spectrophotometers, Primarily for Use with Electrothermal Atomisers 135 Summaries of Papers 'Short Papers in Pharmaceutical Analysis' 135 'Current Methods in Surfactant Analysis' Health and Safety in the Chemical Laboratory - Where do we go from here? 142 150 Equipment News 152 EEC Directive 153 Conferences and Meetings 154 Publications Received 154 Courses 154 Obituary 155 Analytical Division Diary This publication provides an overview of health and safety developments in the chemical laboratory and workplace, and will provide essential reading for anyone involved in these areas.Brief Contents: Accident and Dangerous Occurrence Statistics in the United Kingdom; Morbidity and Mortality Studies; Economics of Health and Safety Measures; Procedures and Statistics in France; Professional Negligence, Liability and Indemnity; The System in the United States of America; The System in the United Kingdom; The System in the Federal Republic of Germany; Hazards of Handling Chemicals; Hazards of Apparatus, Equipment and Services; Managing People; What Standards Should We Use? Conflict of Safety Interests with Legislation; The Protection of Workers Exposed to Chemicals: the European Community Approach; Recommendations Arising from the Symposium.Special Publication No. 57 Softcover 206pp 0 85186 945 9 Price f 16.50 ($30.00). RSC Members f 12.00 ~ ~~ Ordering: Non-RSC Members should send their orders to: The Royal Society of Chemistry, Distribution Centre, Blackhorse Road, Letchworth, Herts SG6 1 HN, England. RSC Members should send their orders to: The Royal Society of Chemistry, Membership Officer, 30 Russell Square, London WClB 5DT. The Royal Society of Chemistry Burlington House, Piccadilly London W1V OBN Electronically typeset and printed by Heffers Printers Ltd, Cambridge, England ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Chemical i s a monthly current awareness bulletin providing worldwide coverage of recent literature on hazards safe working practicc those working in the and allied industries.CHI issues contain over 200 items drawn from the wor Id's cur rent scientific and technical I itera t ur e - keeping you up to date in your area of interest! CHI references include titles, bibliographic details and FULL ABSTRACTS! CHI is divided into sections to give you quick and easy access to relevant topics! CHI is indexed by Chemical and Subject (cumulated annually) to aid location of specific items - making it the perfect tool for both current awareness and retrospective searching ! / [ J \ 157 AMAJOR SAFETY PUBLICATION! ( 3rd Edition) HAZARDS IN THE CHEMICAL LABORATORY deals with safety measures,; practice and toxic effects:- 0 Health & Safety at Work Act '74 0 Safety Planning 8 Management 0 Fire protection 0 Reactive Chemical Hazards 0 Health Care & First Aid 0 Hazardous Chemicals 0 Precautions against Radiations 0 Chemical Hazards & Toxicology Regarded by many as the most authoritative, comprehensive source of chemical laboratory safety information. For prices, further details and a FREE SAMPLE of CHI contact:- The Royal Society of Chemistry The University Nottinaham NG7 2RD Tel: 0602 50741 1 Telex: 37488 ENGLAND

ISSN:0144-557X    

DOI:10.1039/AP98522BX019

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 125 Annual General Meeting of the Analytical Division The thirteenth Annual General Meeting of the Analytical Division of the Royal Society of Chemistry was held at 6 p.m. on Thursday, April 18th, 1985, at the University, Exeter. The Chair was occu- pied by the President, Mr. P. G. W. Cobb, CChem, FRSC, DGA. The Report of the CounciI for the year ending April, 1985, was presented by the Honorary Secretary and adopted. The Scrutineers, Mr. F. W. Sweeting and Mr. R. H. Toft, reported that no ballot had been required for the officers of the Division and the following would therefore serve for the coming year- President-P. G. W. Cobb, CChem, President-Elect-D. C. M. Squirrell. FRSC, DGA. Immediate Past President- Vice-Presidents-T. B.Pierce and Honorary Treasurer-D. C. M. Honorary Secretary-R. Sawyer. Honorary Assistant Secretary- s. Greenfield. A. Townshend. Squirrell. D. I. Coomber (Programmes Secre- Other Members of Council-The Scrutineers further reported that 632 valid ballot papers had been received and that votes had been cast in the election of Ordinary Members of Council as follows: C. Burgess, 432; D. T. Burns, 419; W. C. Campbell, 367; A. G. Fogg, 417; C. W. Fuller, 376; C. J. Jackson, 334; C. A. tary). Johnson, 434; D. G. Porter, 457; D. Simpson, 461; R. D. Snook, 325. The President declared the following to have been elected Ordinary Members of Council for the ensuing 2 years: C. Burgess, D. T. Burns, W. C. Campbell, A. G. Fogg, C. W. Fuller, C. A. Johnson, D. G. Porter and D.Simpson. B. J. Birch, H. E. Brookes, G. J. Dickes, J. N. Miller (Chairman of the Programmes Committee), E. J. Newrnan, J. M. Ottaway, A. M. Ure and J. Whitehead, having been elected Mem- bers of the Council in 1984, will, by the Rules of the Division, remain Members of the Council for 1985/6. A. F. Fell (Chairman of the Scottish Region), A. J. Harrison (Chairman of the126 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Analytical Methods Committee), J. G. Jones (Chairman of the SAC 86 Executive Committee), P. Morries (Chairman of the North West Region), J. Newham (Chair- man of the North East Region), E. B. Reynolds (Chairman of the Western Region), H. I. Shalgosky (Chairman of the South East Region and the Analytical Abstracts Editorial Committee), P. B . Smith (Chairman of the Midlands Region), G. Svehla (Chairman of the 17th. Northern Ireland Region), J. F. Tyson The Annual General Meeting was held (Honorary Publicity Secretary), [to be during the Symposium in honour of confirmed: C. A. Watson (Chairman of Professor E. Bishop. The seventeenth the Group Liaison and Policy Commit- SAC Gold Medal, the tenth and eleventh tee)] and B. W. Woodget (Chairman of AD Distinguished Service Awards and a the East Anglia Region) will be ex officio special award to Professor Bishop were Members of the Council for 1985/6. The presented at a celebratory dinner follow- Honorary Officers and new Members of ing the AGM, a report on which will be Council will assume their duties on July published in a subsequent issue.

ISSN:0144-557X    

DOI:10.1039/AP985220125b

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

126 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Analytical Division Distinguished Service Award As was reported in the March issue (p. 57), the tenth and eleventh Analytical Division Distinguished Service Awards have been conferred on Mr. P. R. W. Baker and Dr. J. E. Page. Leaving school with Higher School Certif- icate (“‘A’ levels”) in 1941, Peter Baker went to work at the Research Association of British Rubber Manufacturers at Croy- don, where he was laboratory assistant to Dr. Hugo Spiel, working on rubber “extenders.” At the same time he started studying part-time at Woolwich Poly- technic, but after about a year he contrac- ted tuberculosis, necessitating nearly a year’s rest. He wonders whether this was due to “burning the candle at both ends and in the middle,’’ as he was working in a carbon black impregnated atmosphere by day, attending evening classes in an atmo- sphere of chalk dust, and spending his spare time playing in dance bands in smoky dance halls, or sleeping in an ill-ventilated basement on civil defence duty! Recovered, he was advised to take a “cleaner” job nearer home (Croydon being all of 4 miles away!) and joined the Wellcome Research Laboratories at Beckenham, where he spent 2 years in the laboratory of their penicillin plant.When this plant closed in 1946, he transferred to the microanalytical laboratory in the Chemical Research Department, where an interest in small-scale techniques was encouraged by the Senior Microanalyst, Arthur Bennett, one of the “first genera- tion” of English microanalysts. In 1949, having gained the qualifica- tions of ARIC and BSc, he joined the Research and Development Department of the British Oxygen Company, at Mor- den, but after only a year or so was invited to return to the Wellcome Laboratories to take charge of the microanalytical labora- tory, a position he held until his recent retirement.He joined the Society of Public Analysts and Other Analytical Chemists (as it then was) in 1948, and became an active member of the Microchemistry Group, first joining the Committee in 1955. He became Assistant Secretary to Doris Butterworth in 1969, and Secretary in 1971, the position that he still holds. He has served on several sub- committees of the AMC concerned with microchemistry: the Microanalytical Standards and Reagents Sub-committeeANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 (1956-1962 and 1969-1972), the Direct Micro-Determination of Oxygen Sub- committee (1955-1957) and the Ana- lytical Standards Sub-committee (1961- 1976).He also served for a short time as the Divisional representative on the re- convened BSI committee dealing with microchemical apparatus (LBC/1 l), in 1975. (His recollection is that this Com- mittee met twice, and then disbanded itself!) He accepted early retirement in 1984, and claims to have been busier during the last year than for many years past. He doubts if the Wellcome Foundation knew how much it was subsidising his secretarial activities: he didn’t know himself until he retired! Away from the laboratory, his principal hobby is music; he reckons to have played his trumpet (with perhaps more enthu- siasm than skill!) in all possible musical ensembles, from 4-piece dance bands to full orchestras, and, in the course of this activity, to have seen the inside of most mental hospitals within a 20-mile radius! He enjoys playing croquet in the sum- mer, edits his local church magazine, acts as unofficial adviser to the Guide move- ment (his wife being the local Division Commissioner) and admits, like Dr.Diana Simpson, a previous recipient of the award, to being a crossword addict. James E. Page was born in Monmouth- shire and educated at Newport High School, the University College of South Wales and Monmouthshire and Cardiff Technical College, where he obtained BSc (1936) and PhD (1938) degrees of London University. He became an AIC in 1937 and a FIC (now FRSC) in 1942.After a short spell on glass electrode research with the Cambridge Instrument Co. he joined, in 1939, the research staff of Glaxo Laboratories at Greenford, where he was based until retirement in 1980. His work for Glaxo varied widely and, over the years, included the develop- ment and application of polarographic, ion exchange, solvent extraction, crystal- lographic, radioactive isotope and ultra- violet, infrared, NMR and mass spec- trometric methods to problems involving antimonial and thyroid drugs, vitamins, antibiotics and steroids. He has published about 100 papers and, in 1957, was awarded the DSc degree of London Uni- versity. Shortly after joining the Society of Public Analysts and Other Analytical Chemists in 1943, Dr.Page became a founder member of the Microchemical Methods, Physical Methods (now Special Techniques) and Biological Methods Groups. His main interest lay with the Physical Methods Group, of which he became Honorary Secretary (1946-1951), Vice-chairman and Chairman (1953- 1957). It was an exciting time for analy- tical chemistry. New methods, some of which had evolved during secret wartime work, were becoming available and were starting to displace older classical proce- dures. The Physical Methods Group pro- vided an important service by organising educational meetings on the new methods. It is significant that the topics, e.g., electrochemistry, radiochemistry, chromatography, ultraviolet, infrared and NMR spectroscopy, selected for these meetings later became the subjects for new specialist groups, which flourish either inside or outside the Analytical Division. His four terms as a member of Council, namely 1948-1949,1956-1957,1977-1979 and 1980-1982, covered the period of expansion and of transition of the SPAOAC, through the SAC to the Analytical Division of the Chemical 127 Society and then to the Analytical Divi- sion of the RSC.Dr. Page has served on the Analytical Methods Committee (194&1954), The Analyst Publication Committee (1951-1956) and the Abstracts and Indexes (now Secondary Services) Committee (1978-1981), and he is currently a member of the Analytical Abstracts Editorial Committee (from 1964) and of the Analytical Books Com- mittee (from 1984). He represented the Society on the Barker Index of Crystallo- graphy Committee (1948-1969, the Infrared Absorption Data Joint Commit- tee (1951-1955) and the BSI Committee on pH Measurements (since 1951). Dr. Page is active with other scientific societies, and has served, inter alia, on the Editorial Boards of Chemistry and Industry, the Journal of Applied Chemistry and Biotechnology, the Journal of the Science of Food and Agriculture and the Journal of Electroanalytical Chemistry. He is an emeritus member of the Biochemical Society and of the American Chemical Society and is a life member of the Society of Chemical Industry. Although “retired,” he still participates in meetings of the Analytical Division, maintains his interest in activi- ties of the National Trust and of the British Museum Society, and finds time for foreign travel (from China to Peru) and for exploring hidden corners of the English countryside.

ISSN:0144-557X    

DOI:10.1039/AP985220126b

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

128 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 RSC ANALYTICAL DIVISION A Meeting is being arranged on Burning Topics in Analysis to be held at The Scientific Societies Lecture Theatre, 23 Savile Row, W.l Wednesday, 23rd October, 1985, at 10.30 a.m. The meeting will open with the first L. S. Theobald Lecture which will be given by Professor E. Bishop (University of Exeter) and his subject will be ”FIRE IN FLIGHT” The remainder of the meeting will consist of short papers on the applications of analysis to various aspects of fires, including prevention and safety precautions, detection, determination of causes, insurance matters, etc. Offers of papers for this meeting should be made to Dr. D. I. Coomber, 8 Rowben Close, Totteridge, London N20 8QR. Report by the Analytical Methods Committee Evaluation of Analytical Instrumentation.Part II. Atomic-absorption Spectrophotometers, Primarily for Use with Electrothermal Atomisers Analytical Methods Committee Royal Society of Chemistry, Burlington House, Piccadilly, London W l V OBN A method is provided for comparing the features of atomic-absorption spectrophotometers that have been designed for use with electrothermal atomisers. The Analytical Methods Committee has received and approved the following report from the Instrumental Criteria Sub-Commi ttee. Introduction The following report was compiled by the above Sub- Committee of the AMC, which consisted of Professor s. Greenfield (Chairman), Professor E. Bishop, Mr. N. W. Barnett, Dr. L. Ebdon, Dr. E. J . Newman (from October, 1984), Mr.D. Squirrell, Dr. P. Smith, Mr. A. Westwell (until June, 1984) and the late Professor G. F. Kirkbright (corre- sponding member) with Mr. C. A. Watson as Honorary Secretary. The purchase of analytical instrumentation is an important function of many laboratory managers, who may be called upon to choose between a wide range of competing systems which are not always easily comparable. The objective of the Instrumental Criteria Sub-committee is to tabulate a number of features of analytical instruments which should be con- sidered when making a comparison between various systems. As is explained below, it is possible to then score these features in a rational manner, which allows a scientific comparison to be made between instruments. The over-all object is to assist purchasers in obtaining the best instrument for their analytical requirements.It is also hoped that, to a degree, it will help manufacturers to supply the instrument best suited to their customers’ needs. No attempt has been made to lay down a specification. In fact, the Committee considers that it would be invidious to do so; rather, it has tried to encourage the purchasers to make up their own minds as to the importance of the features that are on offer by manufacturers. This second report of the Sub-committee deals with atomic-absorption spectrophotometers that are primarily intended for use with electrothermal atomisers. Notes on the Use of this Document Column 1. The features of interest. Column 2. What the feature is, and how it can be evaluated. Column 3.The Sub-committee has indicated the relative importance of each feature and expects users to decide on a weighting factor according to their own needs. Column 4. Here the Sub-committee has given reasons for its opinion as to the importance of each feature. Column 5 onwards. It is suggested that scores are given for each feature of each instrument and that these scores are modified by a weighting factor and sub-totals obtained. The addition of the sub-totals will give the final score for each instrument. Notes on scoring 1. (PS) Proportional scoring. It will be assumed, unless otherwise stated, that the scoring of features will be by proportion, e.g., Worst/O to Best/100. 2. (WF) Weighting factor. This will depend on individual requirements. An indication of the Sub-Committee’s opinionANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 129 , of the relative importance of each feature will be indicated by the abbreviations VI (very important), I (important) and NVI (not very important).A scale is chosen for the weighting factoi which allows the user to discriminate according to needs, e.g., x l to x3, or, x 1 to ~ 1 0 . The factor could amount to total exclusion of the instrument. 3. (ST) Sub-total. This is obtained by multiplying PS by WF. I 7 INSTRUMENTAL CRITERIA SUB-COMMITTEE INSTRUMENT EVALUATION FORM Type of Instrument: Atomic-absorption Spectrophotometers for Electrothermal Atomisation Manufacturer: Model No: Feature 1. Hollow-cathode lamp supply ( a ) Method of lamp alignment ( b ) Modulation 2. Atomiser (a) Alignment (b) Electrical contact ( c ) Tube dimen- sions ( d ) Accessibility for sample intro- duction ( e ) Purge gas entry (f) Ease of rever- sion to flame operation (8) Cooling system ( h ) Tube compo- sition and coatings (i) Tube replace- ment and ease of cleaning Definition and/or test procedures and guidance for assessment Two axis adjustment by accessible controls preferred.Type and frequency-score high for electronic modul- ation, non-multiples of mains frequency and also for highest frequency Maximum score for stable, lateral, rotational and vertical adjustment with good accessibility. Score maximum for greatest area of contact compatible with robustness and simple replacement of tube. Score highest for smallest tube with a sample capacity of 25 p1 and with the ability to hold a platform of at least 10 pl sample capacity.Score highest for furnace with ready access. Score maximum for gas entry at end of tube with exit in middle. Maximum score for simplicity of change-over. Score highest for most rapid cooling, with reasonable economy of gas or water. Score maximum for the widest range of materials and coatings available. Score highest for simple dismantling of tube and work- head. - mportance VI I VI VI VI v1 v1 I I I I Reason Alignment of source on optical axis, particularly important for ETA because of the need to match cxactly the beam from the line source and the continuum source if used for background correction. Suppression of mains noise and unwanted d.c. signals, in particular emission from the Eurnace walls.Signal rise time is very short, therefore signal distortion may be considerable if modulation frequency is low. Alignment of furnaces critically affects reproducibility and sensitivity. Consistent low contact resistance ensures reproducible heating cycles and increases lives of tube and furnace. Small tubes heat up rapidly, whereas large tubes simplify sample handling and give longer residence time. This recom- mendation is thought to be a reasonable compromise between Zonflicting requirements. Facilitates manual sample introduction and may allow use of slurries and solid samples. Reduces non-specific absorption and fogging of windows if fitted. Self-explanatory. Increases speed of analysis and improves reproducibility of operating conditions and analytical results.Some coatings, e.g., pyrolytic, increase sensitivity for some elements and reduces certain interferences. Regular cleaning is required to prevent contamination of tubes and furnace structure. Score PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST -130 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Feature 2A. Atomiser power (a) Maximum temperature supply (6) Maximum heating rates ( c ) Stabilisation (d) Capacity 3. Monochromator - optics ( a ) Temperature stability (6) Background correction. (See NOTE I) ( c ) Focal length and f number (d) Slits (e) Grating cf> Wavelength ( i ) Readout precision Definition and/or test procedures and guidance for assessment Score maximum for highest temperature attainable.Score maximum for fastest temperature rise time attainable. Score maximum for temperature feed-back system which operates over widest range of temperatures. Optical sensors are rapid and reliable at higher temper- atures. Thermocouple and resistance thermometer based systems are useful when close temperature control is important at lower temper- atures. However, these devices suffer from problems of fragility and contact reproducibility. Voltage feed-back control is less effective than the above systems. Score maximum for highest power rating compatible with acceptable size and ability to operate from available power supply. A h / T change in wavelength per degree. The smaller this value the better is the stability. Score maximum for efficient simultaneous background correction for the maximum number of elements.Additional score for ease of replacement of source if used. Score maximum for long focal length and highfnumber. Score maximum for contin- uously variable slits, intermediate for stepwise adjustment, minimum for fixed dits. Additional score for kight adjustment facility. Modified Czerny - Turner mount generally preferred to Ebert or Littrow as stray light characteristics are better. Maximum score for blaze angle nearest wave- lengths of maximum interest. Four-figure digital readout preferred. [mportana VI VI VI I VI VI I I I I Reason Higher temperature facilitates the determination of refractory elements. Higher temperature rise rates increase sensitivity for some elements and minimise matrix interference. Reproducible temperatures are essential for accurate and reproducible results.Convenience and ability to heat furnace to the maximum temperature rapidly and reproducibly . Elimination of instrumental drift, particularly important with long sample runs using an autosampler. Obligatory for ETA due to high non-atomic absorption. Compatibility of optical beam and furnace tube dimensions, so as to avoid excessive loss of source radiation and prevention of furnace wall emission from reaching the detector. Full control of slit adjustment allows spectral discrimination and control of luminous flux. Suitable blaze angle required to ensure adequate source radiation throughout range of interest. The useful working range is approx- imately from 2/3 to 3 times the blaze wavelength, the fall in efficiency being particularly sharp at short wavelengths.Ease of re-setting instrument. Scon PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST -130 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Feature 2A. Atomiser power (a) Maximum temperature supply (6) Maximum heating rates ( c ) Stabilisation (d) Capacity 3. Monochromator - optics ( a ) Temperature stability (6) Background correction. (See NOTE I) ( c ) Focal length and f number (d) Slits (e) Grating cf> Wavelength ( i ) Readout precision Definition and/or test procedures and guidance for assessment Score maximum for highest temperature attainable. Score maximum for fastest temperature rise time attainable. Score maximum for temperature feed-back system which operates over widest range of temperatures.Optical sensors are rapid and reliable at higher temper- atures. Thermocouple and resistance thermometer based systems are useful when close temperature control is important at lower temper- atures. However, these devices suffer from problems of fragility and contact reproducibility. Voltage feed-back control is less effective than the above systems. Score maximum for highest power rating compatible with acceptable size and ability to operate from available power supply. A h / T change in wavelength per degree. The smaller this value the better is the stability. Score maximum for efficient simultaneous background correction for the maximum number of elements. Additional score for ease of replacement of source if used.Score maximum for long focal length and highfnumber. Score maximum for contin- uously variable slits, intermediate for stepwise adjustment, minimum for fixed dits. Additional score for kight adjustment facility. Modified Czerny - Turner mount generally preferred to Ebert or Littrow as stray light characteristics are better. Maximum score for blaze angle nearest wave- lengths of maximum interest. Four-figure digital readout preferred. [mportana VI VI VI I VI VI I I I I Reason Higher temperature facilitates the determination of refractory elements. Higher temperature rise rates increase sensitivity for some elements and minimise matrix interference. Reproducible temperatures are essential for accurate and reproducible results. Convenience and ability to heat furnace to the maximum temperature rapidly and reproducibly .Elimination of instrumental drift, particularly important with long sample runs using an autosampler. Obligatory for ETA due to high non-atomic absorption. Compatibility of optical beam and furnace tube dimensions, so as to avoid excessive loss of source radiation and prevention of furnace wall emission from reaching the detector. Full control of slit adjustment allows spectral discrimination and control of luminous flux. Suitable blaze angle required to ensure adequate source radiation throughout range of interest. The useful working range is approx- imately from 2/3 to 3 times the blaze wavelength, the fall in efficiency being particularly sharp at short wavelengths. Ease of re-setting instrument. Scon PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST -ANALYTICAL PROCEEDINGS.MAY 1985, VOL 22 132 Feature ~~ ~ ~ _ _ _ 8. Output ( a ) Readout types (b) Interface (c) Curve fitting software 9. Programming of operational parameters ( a ) Stages in operational cycle (b) Ramplstep (c) Sequence control ( d ) Fail safe/manua override provision ( e ) Programme sequence storage (f) Operational 10. Sample handling system ( a ) Sample intro- duction (b) Number of samples and standards (c) Facilities for sample and standard manipu- lation and treat- ment Definition and/or test procedures and guidance for assessment Score maximum for avail- ability of analogue, digital, printer and graphic outputs. Score maximum for suitable standard interface, e.g., RS232, IEEE, BCD or ASCII.Score maximum for avail- ability of statistically valid procedures. Number of independently programmable heating cycles- minimum requirement “dry,” “ash,” “atomise” and “clean.” Score extra for additional division of “ash” and “dry” stages. Number and range of heating rates available for each stage of operational cycle. Score maximum for greatest versatility. Can be microprocessor or electromechanical. The Eormer, although more expensive, is to be preferred. Score accordingly. Score maximum for sensors to detect failure of cooling water, furnace temperature werrun and inert gas flow, together with provision for manual override of any Dperation. Score maximum for maximum number of programmes that :an be automatically retrieved.Score maximum for full read- Iut of temperature - time iequence. Score maximum for fully automated sample handling system. Score maximum for sample turntable that allows maximum number of samples to be run with unattended operation, without degradation of calibration functions. Score maximum for most versatile programme(s) for standard dilution/additions, matrix modification, replica- tion and rinsing. Importance VI I I VI I VI VI I VI VI I I Reason Digital readout and printer are particularly suitable for quality control applications and measurement of small signals. Analogue and graphic outputs are beneficial for measuring transient peaks and developing methods and procedures. To maximise compatibility with available printers or computers. “Least Squares” hyperbolic or polynomial fitting enables the use of moderately curved calibration functions without significant loss of precision.The four basic stages are essential; for more complex matrices, ability to vary drying and ashing stages in steps may greatly reduce matrix effects. Ability to vary heating rate within each stage may enable an interfering matrix to be removed without loss of analyte. Reproducible control of operating sequence, after setting up, is essential. Microprocessor controlled instruments may not require “ramp” facilities, as each step can be sub-divided according to the user’s needs. Instrument protection. Convenience of operation. Essential to check operational 3arameters and for development If analytical procedures. Automatic sample introduction improves precision and speed and may reduce interferences and improve accuracy.Speed, convenience and accuracy. Allows more flexible automation and more efficient operation. Score PS WF ST PS WF ST PS WF ST - PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST - PS WF ST PS WF ST PS WF STANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Feature ( d ) Range of sample sizes ( e ) Control system 11. Over-all performance ( a ) Base line stability (see NOTE: 11, I11 and IV) ( b ) Tube life (c) Figures of merit (i) Precision (ii) Sensitivity (slope of calibration curve) Definition and/or test xocedures and guidance [or assessment Scorie maximum for widest range of sample size without undue loss of precision, bearing in mind furnace zapacity. Score maximum if linked to microcomputer that controls Furnace operation.With the furnace in position allow 30 min for spectrometer to warm up then take readings at 2-min intervals for 1 h. Take a further 30 readings at 2-min intervals, each after injecting 10 pl of 1 % sodium chloride solution using the following pro- gramme: 10 s dry at 100 “C, 30 s ash at 800 “C and 2 s atomise at 3000 “C, followed with 4-s clean at maximum temperature and 70 s for cooling. Calculate standard deviations, check for drift and score accordingly. Set up the instrument according to the manufact- urer’s recommendations for the analysis of lead. Use 1 % sodium chloride as the matrix and include a 4 s clean at maximum temperature. Repeat this analysis until either the signal undergoes a marked reduction, the precision degrades or the tube fails completely.Score maximum for the largest number of cycles before unacceptable degradation of precision, accuracy or tube occurs. Use a blank and concen- trations of test elements to give nominal absorbance of 0,0.005,0.01,0.02,0.05, 0.1,0.2,0.5 and 2.0 based on the manufacturer’s sensitivity data, assuming that a linear relationship exists. Measure each solution at least six times, using scale expansion for readings below 0.1. Solutions of 0.01 and 0.2 should be measured at suitable intervals to obtain 30 replicates from which the precision data can be obtained. Calculate standard deviation and score maximum for lowest. Calculate slope of line and score maximum for highest slope. ~~~ mportance NVI I VI I VI VI Flexibility and convenience.[mproves degree of automation. Replication combined with online statistics can ensure analysis IS performed to preset confidence limits. Affects accuracy and precision. This is particularly important if unattended automatic operation is envisaged. The first series of measurements evaluates electronic stability while the subsequent measurements test the ability of the furnace to clear a matrix successfully without “fogging” any optical surfaces. Affects ability of instrument to be left for long periods of unattended operation. May have considerable bearing on instrument running costs. Self explanatory. Self explanatory. kore PS WF ST - PS WF ST PS WF ST PS WF ST PS WF ST PS WF ST134 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Feature (iii) Linear rang€ ( i v ) Detection limit ( v ) Curve correction 12.Value for money Points per sf Definition and/or test procedures and guidance for assessment Calculate from calibration curve. Score highest for widest linear range. Calculate the concentration of solution that gives rise to a signal equal to twice the standard deviation of the reagent blank, measured at or near the limit of detection. Score maximum for lowest. Use the curve correction facility to linearise the calibration function and analyse a solution with a known concentration and a nominal absorbance of 1.2-1.5. Score maximum for the most accurate result. Sum of previous sub-totals divided by the purchase price of the instrument. Subject to proportional scoring and weighting factor as for previous features. Include ST in grand total.[mportance VI VI I I NOTES [I] The efficiency of most background correction systems depends on the availability of equal time constants in both channels of the amplifier and the ability to match the source image in both size and intensity for both channels. Conventional background correction is effec- tive for most situations but is unable to deal with a structured background. Alternative systems, such as Zeeman or Smith - Hieftje, which have recently become available, are thought to be better in this respect and do not require a separate source. However, at the time of publication of this document, the sub-committee is not in a position to evaluate such systems fully. A test for the efficiency can be made by evaluating the effect of a 1000-fold excess concentration of aluminium (as the chloride) on the analysis of a suitable concentration of arsenic at 193.7 nm.This is most easily performed using a direct graphics output, but satisfactory evaluation can be made using a conventional output if the analysis is repeated in the absence and presence of aluminium. Measurements can be made using a high speed recorder, but should normally be obtained as a digital readout from the instrument and printer. In either instance the “peak retrieval” facility should-be used and both peak height and peak areas should be recorded. [11] Reason Self explanatory. Self explanatory. Self explanatory. Simple instruments are often good value for money, whereas those with many refinements are often costly. Score PS WF ST PS WF ST PS WF ST ium of totals PS WF ST sub- Srand total [111] Choice of test matrix. The user can employ any matrix of interest; possibilities include seawater, urine, blood, aluminium chloride and plant material. However, the Sub-committee suggests that convenience may lead to the choice of something more generally available, such as 1-5% sodium chloride solution for most tests. Choice of test element. The user can employ any element(s) thought to be of importance. Some possibili- ties are: Arsenic at 193.7 nm-Evaluates performance at far ultraviolet end of instrument range. Makes considerable demands on background correction facilities if a matrix such as aluminium chloride is used. Lead at 21 7.0 or 283.3 nm-Commonly analysed ele- ment, which is relatively volatile and which may be incompletely resolved from an inorganic matrix. Cadmium at 228.3 nm-The element can be deter- mined with high sensitivity but can be difficult to measure in the presence of even simple matrices such as sodium chloride. Chromium at 357.9 nm-Element with primary analy- tical line near end of the background correction range for deuterium arc lamp systems.

ISSN:0144-557X    

DOI:10.1039/AP9852200128

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 135 Short Papers in Pharmaceutical Analysis ~ ~~~ The following are summaries of five of the papers presented at a Meeting of the Joint Pharmaceutical Analysis Group held on October 18th, 1984, in the Pharmaceutical Society of Great Britain, London S.E. 1. The Separation of Fluphenazine Derivatives by Gradient Elution HPLC 1. Charles and M. L. Robinson International Development Laboratory, E. R. Squib6 & Sons, Moreton, Wirral, L46 7Q W Fluphenazine (I) and its more lipophilic derivatives, fluphew azine enanthate (11) and fluphenazine decanoate (111), are used in the treatment of schizophrenia. Previous HPLC work has concentrated on the development of isocratic elution methods on reversed-phase columns for the separation of fluphenazine from its oxidation products,' or fluphenazine decanoate from its oxidation products ,1 or fluphenazine decanoate from other fluphenazine esters.* We were interested in developing a single HPLC method which could be used to separate these com- pounds, and ultimately be used for the quantitation of each component in complex mixtures.( I ) R = H (11) R = COCeH13 (111) R = COCgH1g (IV) R = COC17H35 Fig. 1. Fluphenazine and some derivatives In practice, the analysis time required for an isocratic elution method with good peak separation was so long that the peaks for the late-eluting components [e.g., long-chain esters such as fluphenazine stearate (IV)] were unacceptably broadened. Attention was therefore turned towards a gradient elution method. Experimental A SpectraPhysics SP 8100 programmable delivery system was used in association with an SP 8440 ultraviolet - visible detector and an SP 4200 computing integrator. The HPLC column chosen for the method was a C8 reversed-phase cartridge (8 mm i.d.) used in a Waters Z-module; this readily available commercial column has a bonded phase of shorter chain length than the usual CI8 reversed phase, but longer chain length than the Hypersil - SAS or Partisil- TMS used previously for iso- cratic methods.1.2 The detection wavelength was 260 nm, the maximum for the phenothiazine chromophore provided that the sulphur atom is not oxidised (with sulphur oxidation the absorption maximum shifts to a longer wavelength, although detection at 260 nm is still possible).A flow-rate of 3 ml min-1 was used throughout.Three compounds were chosen as marker points for the chromatographic separation. Fluphenaz- ine (I) was required to appear near the beginning of the run, fluphenazine decanoate (111) was chosen to be approximately at the mid-point of the run, and fluphenazine stearate (IV) acted as an end of run marker. The mobile phases were adapted from those used in the isocratic methods.1.2 Phase A consisted of a 2 : 2 : 1 mix of acetonitrile - methanol - aqueous (1%) ammonium carbonate. Phase B was a 10 : 10 : 1 mix of the same components. Several linear gradients were tried, in which the eluent composition was changed smoothly from 100% A to 100% B over a set time period ( e . g . , 10-15 min) and then held steadily at 100% B until the fluphenazine stearate had been eluted.Good spacing of the marker peaks was immediately achieved; however, when further fluphenazine esters such as myristate, oleate and linoleate were included in the run it was soon apparent that more time was required between the decanoate and stearate ester peaks for adequate peak spacing. A simple modification of the gradient, involving a run to 80% B (20% A) over 10min and then a shallow incline to 100% B at 20min, accommodated the three extra esters easily. The enanthate ester (11) and the two mono-N-oxides of fluphenazine decan- oate were also included, and these eluted with good separation between the fluphenazine and fluphenazine decanoate peaks, making a total of nine compounds separated in a single run. This method was successfully applied to extracts from samples of degraded fluphenazine decanoate in sesame oil formula- tions. However, several modifications were required in order to accommodate more fluphenazine related compounds.To retard the fluphenazine peak and allow more room for the early eluting fluphenazine oxide peaks, the initial mobile phase A was adjusted to 3 : 3 : 2 acetonitrile - methanol - aqueous (1%) ammonium carbonate and the gradient was modified to deliver 100% A for several minutes after the start of the run. Introduction of fluphenazine palmitate gave a problem, involving co-elution of the palmitate and oleate esters, but this was overcome by extending the run time to 35min and adopting a shallow, multi-step gradient. The final peaks were still sharp and base-line drift remained negligible. Fluphenaz- ine dodecanoate was also included in the run, eluting as expected between the decanoate and myristate esters.The sulphoxide of fluphenazine was also incorporated and eluted ahead of fluphenazine as predicted. Two further compounds, fluphenazine octanoate and fluphenazine decanoate di-N- oxide, unfortunately co-eluted just ahead of the decanoate mono-N-oxides. They were successfully separated by allowing a longer period of 100% mobile phase A after the start of the run, thus retaining all compounds for a longer period on the column. Some resultant peak broadening was corrected by gradient steepening, and a final separation of fourteen compounds was achieved (see Fig. 2) using a 4-stage gradient.136 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 5 1 0 Fig. 2.HPLC of 14 fluphenazine related compounds (retention times in minutes). Peaks are: 1, fluphenazine sulphoxide (3.09); 2, fluphenazine (5.05); 3, fluphenazine enanthate (12.55); 4, fluphenazine decanoate di-N-oxide (14.09); 5, fluphenazine octanoate (15.56); 6 and 7, fluphenazine decanoate mono-N-oxides (16.39 and 18.05); 8, fluphenazine decanoate (20.46); 9, fluphenazine dodecanoate (24.29); 10, fluphenazine myristate (28.87); 11, fluphenazine linoleate (31.08); 12, fluphenazine palmitate (34.21); 13, fluphenazine oleate (34.98); 14, fluphenazine stearate (39.83). The run time is now close to 40min but base-line drift is The prospects appear good for developing this method, both to accommodate further compounds as required and to allow quantitative measurements.309. ’ References and the later peaks are not 1. Heyes, W. F., Salmon, J. R., and Marlow, W.,]. Chromatogr., 1980, 194,416. 2. Heyes, W. F., and Salmon, .I. R., J . Chromatogr., 1978, 156,ANALYTICAL PROCEEDINGS, MAY 1985. VOL 22 137 radioactivity was eliminated in the urine. The extraction characteristics indicate that this is not unchanged reserpine. Seventy-seven per cent. of the administered radioactivity was eliminated in the faeces in 7 d. ~~~~~ ~ ~ Table 1. Cross-reactivities of reserpine radioimmunoassay Compound Reserpine Methyl reserpate Reserpic acid Rescinnamine S yringosingopine Deserpidine Methoserpidine Corynanthine Y ohimbine Trimethoxybenzoic acid Serotonin analogues in the reserpine Cross-reaction, % 100 178 117 68 49 33 15 <0.005 <0.001 <0.0002 <0.0002 The percentage cross-reaction is expressed as (xly) x 100, where x is the mass of reserpine and y the mass of cross-reacting compound required to produce 50% inhibition of the binding of [3H]methyl reserpate by the antiserum. Discussion Levy et a1.2 and Loeffler and Schran3 reported the develop- ment of specific radioimmunoassays for reserpine.The appli- cation of these methods was limited by the sensitivity of the assays. This paper describes the development of a quick and sensitive radioimmunoassay for the detection of the adminis- tration of therapeutic doses of reserpine to a horse. The three methods of analysis of plasma and urine following reserpine administration all indicate the presence of reserpine in plasma at low levels for a considerable time following its intramuscular injection.There is no detectable excretion of unchanged reserpine in urine, the predominant elimination route for reserpine in the horse being faecal. References 1. 2. 3. Sams, R., Anal. Lett., 1978, B11, 697. Levy, A., Kawashima, K., and Spector, S., Life Sci., 1976, 19, 1421. Loeffler, L. J., and Schran, H. F., J. Pharm. Sci., 1979, 68, 1433.138 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 This concept is automated further using the Du Pont Prep I sample preparation unit which processes disposable columns in a centrifugal rotor that is capable of rotating in both directions. Samples are loaded on to the columns and as they are rotated in one direction they are automatically washed with solvent to remove the biological matrix.The rotor then reverses direc- tion, re-aligning the column over a sample collection tube. The desired analyte is then eluted from the column using a second eluent, delivered as the rotor is spinning. The sample in solution can then be analysed by HPLC or reduced to dryness and concentrated prior to analysis. Pre-column Enrichment This technique also utilises solid-phase extraction, but the small column of a chemically bonded stationary phase is mounted in the HPLC system, e . g . , in the loop of the high pressure injection valve (Fig. 1). The sample is introduced on to the loop column via the injection port and washed with washing solvent to remove the biological matrix. The loop column is then re-introduced into the analytical mobile phase stream and the sample back flushed on to the analytical column.This technique has been used for the assay of the CJ-blocker nadolol in urine.5 The urine sample (0.5ml) is loaded on to a Lichoprep Si60 ODS column mounted in the loop of the injector. The loop column is flushed with water to remove endogenous material, and the valve then turned to the load position. This introduces the loop column to the mobile phase stream and the enriched nadolol sample is back-flushed on to the analytical column. Pump I Analytical column Valve Load position Injection port Loop column Pump Analytical column Injection port Loop column Fig. 1. Single pre-column enrichment The loading of samples can be further automated by the use of two injection valves, each containing an enrichment column6 (Fig.2). The two pre-columns are loaded alternately by direct injection of the biological sample and then purged with buffer - water to remove the biological matrix from the pre-column. While one pre-column is loaded and flushed with water, the second pre-column, which should be loaded one cycle before, is switched into the eluent stream of a second pump, which delivers the chromatographic eluent and initiates back-flushing of the enriched material to the analytical column. At the same time, the other column is switched back into the buffer - water stream of the first pump for reconditioning. The valves may be controlled by a periodically programmed time function, which allows continuous fully automated HPLC without any manual handling of the biological sample.There are several points to note with this type of automated sample analysis. No loss in analytical performance is found as a consequence of the essentially plug-like injection of the drugs from the back- flushed column. If the clean-up column is changed regularly the analytical column can be used for many thousands of injections without serious deterioration in its efficiency. Drug recoveries in excess of %YO, and often up to loo%, can be observed with low coefficients of variation.5.7 Pre-col 1 Pump A (washi Pump ‘ B (elute) Fig. 2. Fully automated alternating pre-column enrichment HPLC Autosampling and Data Collection Several commercial HPLC autosamplers are available, which are suitable for biological samples.The major considerations are that an autosampler must be able to handle small volumes and be reliable. Biological sample preparation often produces a small volume of sample (perhaps lOOpl), the majority of which is to be injected (say 80yl). Accurate filling of a loop injector is therefore essential, as is reliability, as many biological samples are unique for a particular time ( e . g . , tissue biopsy during surgery). For complete automation, a data capture and storage system is required, be it a computing integrator, laboratory data station or mini-computer. This allows re-integration of stored data, which is important in biological sample analysis where each sample is unique and there is more likelihood of unexpected peaks in the chromato- gram peculiar to an individual sample.The automation of biological sample analysis using HPLC has much potential and each application should be considered in its own right. Totally automated HPLC analysis with both high sample throughput and precision is now a reality for the analysis of even the most complex biological samples. 1. 2. 3. 4. 5. 6. 7. References Clarke, G. S., and Robinson, M. L., J . Clin. Hosp. Pharrn., 1983, 8, 373. Saraswat, L. D., Holdiness, M. R., and Justice, J. B. J. Chrornatogr. Biomed. Appl., 1981,222, 353. Cross, A. J., Life Sci., 1981, 28, 499. Hupe, D., and Peters, K., Paper presented at International Symposium on Laboratory Robotics, Boston, Massachusetts, 1984. Clarke, G. S., Liu, L. K., and Robinson, M. L., “Methodology Surveys,” Volume 14, Plenum, New York, in the press.Roth, W., Beschke, K., Jauch, R., Zimmer, A., and Koss, F. W., Chrornatogr., Biomed. Appl., 1981, 222, 13. Karger, B. L., Giese, R. W., and Snyder, L. R., Trends Anal. Chem., 1983,2, 106.ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 139 Ultraviolet Spectrophotometric Determination of Gentamicin A. Palmer Royal Devon and Exeter Hospital (Won ford), Barrack Road, Exeter Csiba,’ in a paper describing the determination of aminoglyco- side antibiotics via dihydrolutidine derivatives, was the first to publish the use of the pyridine derivative synthesis (Hantzsch reaction) for the assay of aminoglycoside antibiotics by ultraviolet spectrophotometry. In the same year Csiba2 also utilised the fluorescent properties of the products from the Hantzsch reaction to determine amikacin, kanamycin, neo- mycin, sisomycin and tobramycin in biological fluids.Following this Gupta et al.3 used the Hantzsch reaction as a stability indicator for the aforementioned antibiotics in phar- maceutical dosage forms. Several totally different methods of analysis are available for the determination of gentamicin: these include high-pressure liquid chromatography (HPLC), enzyme mediated immuno- assay (EMIT), fluorescence immunoassay (FIA) , radio- immunoassay (RIA) and microbiological methods. However, by adapting the Hantzsch reaction, gentamicin can also be determined via the dihydrolutidine derivatives using ultraviolet spectrophotometry . Experimental Reagents Acetylacetone, formaldehyde, acetic acid, boric acid, phos- phoric acid, sodium hydroxide.Samples Four separate batches of gentamicin were obtained from three different suppliers: GMS-llRM, 8515 (both Tillets, potencies 592.9 pg mg-1 and 619.6 pg mg-1, respectively), 304.223 (Nicholas, potency 614.5 pg mg-1) and 101-002 (Roussel, potency 619.0 pg mg-1). The condensation reaction proceeds under acidic conditions; for this reason a buffer 0 . 2 ~ in each of acetic, boric and phosphoric acids is used, with the pH being adjusted to pH 2.6 by use of 1 M sodium hydroxide solution. This buffer is stable for at least 30 d. The derivatisation reagent consists of 0.8 ml of acetylace- tone, 1.7 ml of 36% formaldehyde and 10 ml of the buffer, the total volume being brought to 30ml with water; this reagent should be prepared daily. The reagent was then mixed in a 1 : 1 ratio with the gentamicin solution and placed in a boiling water bath for 25min, cooled to room temperature, diluted to acquire an appropriate strength solution and the absorbance measured against a blank at 356 nm.The blank was prepared in the same manner as above, except that water was substituted for the sample or standard. The reaction set up is between the primary or secondary amine sections of the aminoglycoside and the hydroxyl group of the enol form of acetylacetone, formaldehyde reacting with the keto form. With the loss of several water molecules from the primary amine reaction and an ROH from the action of the secondary, the result is an aminoglycoside derivative of dihydrolutidine that absorbs in the ultraviolet. Results and Discussion The results (Table 1) indicate that the reaction does obey the Beer - Lambert law up to a maximum concentration of 20 pg ml-1, giving an A;& of approximately 18 000.Above this concentration (20pgml-1) the assay can be performed by comparing the absorbance value of the test solution with that of a standard of the same strength. Samples or standards of about 20 mg ml-1 starting strength appeared to be too strong for the derivatisation reagent and required appropriate dilution before proceeding with the Table 1. Calibration showing compliance with the Beer - Lambert law. Plotting A against C gives slope q~ = 18 417 Concentration of standard (C), yg ml-1 Absorption ( A ) 50 0.616 40 0.552 30 0.470 20 0.373 15 0.272 10 0.183 5 0.092 assay. Table 2 gives a direct comparison of results between sterile and non-sterile samples; this also includes results obtained by EMIT and microbiological techniques as well as the theoretical concentration of each sample (based on potency).As can be seen, the results are varied but there are no significant trends. However, the ultraviolet assay has a coefficient of variation, based on ten readings, of 1.6%; this is as good as the coefficient of variation obtained for EMIT (1.8%) and considerably better than that for the microbiolog- ical method (6.2%), indicating that the method is suitable for the quantitation of gentamicin. Table 2. Assay results from various methods. Where appropriate, solutions were diluted to achieve a suitable concentration for analysis Concen tration/mg/ml- 1 Sterile Non-sterile Sterile Non-sterile Sterile Non-sterile Sterile Non-sterile Theoretical Ultraviolet EMIT 5.929 6.1 6.1 5.929 6.5 5.5 6.196 6.3 5.6 6.196 6.3 5.4 6.145 6.1 5.0 6.145 6.2 6.7 6.190 5.9 6.1 6.190 5.9 5.6 Micro- biological 6.5 8.3 6.0 5.6 6.4 6.8 7.3 12.0 This method, although giving a quantitative result for gentamicin, does not give any indication about the C-complex proportions that are present in the sample.However, limits have now been set4 for the concentration of each individual C-complex; therefore, HPLC is the only method which can supply information about this. So, for pharmaceutical dosage forms, this ultraviolet assay would have to be used in conjunction with HPLC analysis. Thanks are due to Messrs. Nicholas, Roussel and Tillotts for providing samples of gentamicin sulphate, Exeter Public Health Laboratory for microbiological assay results and Mrs.L. Bower for guidance with the EMIT assay. References 1. Csiba, A., Magy. Kem. Foly., 1979, 85, 166; Chem. Abstr., 1979,91, 35139h. 2. Csiba, A., J . Pharm. Pharmacol., 1979, 31, 115. 3. Das Gupta, V., Stewart, K. R., and Gunter, J. M., J . Pharm. Sci., 1983, 72, 1470. 4. “British Pharmacopoeia 1980: Addendum 1983,” HM Stationery Office, London, 1983.140 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Development and Validation of an HPLC Assay Method for the Simultaneous Determination of Beclomethasone Dipropionate, Beclomethasone 17=Monopropionate, Beclomethasone 21 -Monopropionate and Beclomethasone in Beclomethasone Dipropionate Drug Substance M.Mulholland and D. R. Rudd Analytical Research Department, Glaxo Group Research Ltd., Ware, Hertfordshire, SG 12 ODJ An HPLC assay method for beclomethasone dipropionate (BDP) drug substance and its principal degradation products (beclomethasone 17-monopropionate, beclomethasone 21- monopropionate and beclomethasone) has been developed and validated. This method achieves base-line resolution between each of these components and has an over-all run time of approximately 5 min. It has been satisfactorily validated to the current requirements of the Analytical Research Depart- ment (Glaxo Group Research Ltd., Ware). Introduction The stability evaluation of beclomethasone dipropionate (BDP) drug substance requires the determination of BDP itself and of its principal degradation products (beclomethasone 17-monopropionate, beclomethasone 21-monopropionate and beclomethasone).Methods hitherto available possess signifi- cant limitations (e.g., do not fully separate the monopropion- ates or have excessively long run times). Thus, the aim of the work described in this communication was to develop a new assay method which achieved base-line resolution of all four components within an over-all run time of less than 10 rnin and which, in particular, gave good chromatographic performance (good peak shape, etc.). Experimental and Results Reversed-phase high-performance liquid chromatography was chosen as the most promising technique for further method development. Certain parameters (column temperature, ambient; sensitivity, 0.05 aufs; detection wavelength, 239 nm) were held constant during the development exercise, which involved optimisation of the stationary phase material and the column length, the flow-rate and the mobile phase composi- tion, using the Simplex method' in order to achieve the best separation of the components of interest.Each chromatographic system was evaluated by calculating the resolution factor (Rf), based on an arbitrarily-defined mathematical expression of the form where R1 = R, for the monopropionates, R2 = R, for BDP and beclomethasone 21-monopropionate and R, (the resolution between each pair of peaks) is given by Rf = (50R1) + R2 R,=0.25 N ( a - 1) - J [ 1 L] where N = the number of theoretical plates, (x = the solvent selectivity (the ratio of capacity factors) and k' = the mean of both capacity factors.Note that the resolution between the monopropionates was weighted by a factor of 50, this being considered a particularly important aspect of the desired chromatographic system. Three chromatographic columns were evaluated using vari- ous mobile phases (incorporating acetonitrile, propan-2-01, methanol and water, chosen to give the required range of selectivity2). The optimum mobiIe phase composition and flow-rate were established for each column. From these, the chromatographic conditions as defined in the method presen- ted below were found to satisfy the aims of the method development. Column: 20 cm x 5 mm i.d. Spherisorb Nitrile 5 pm Mobile phase: Acetonitrile (HPLC grade) - distilled water (40 + 60 V/V) Flow-rate: 2.0ml min-1 Temperature : Ambient Detection : UV, 239nm Sensitivity: 0.5 a.u.f.s.(typically) Measurement: Typical retention times: Beclomethasone 2.0 rnin Injection volume: 5 vl (loop) Peak area by data processor Beclomethasone 17-monopropionate 2.5 rnin Beclomethasone 21-monopropionate 2.8 rnin Beclomethasone dipropionate 3.5 rnin The method was then validated according to procedures currently adopted within our laboratories and the following features of the method were established. Firstly, the chromato- graphic system gives good specificity for BDP, both monopro- pionates and beclomethasone. Base-line resolution is achieved between all four components within an over-all run time of 5 min. Secondly, all four components have linear detector responses within the range 50-100% of the concentrations proposed for use in the method.Thirdly, repeated injection of an individual calibration solution gave an RSD of about 0.5% of ten determinations. Repeated preparation of calibration solutions gave an RSD of about 0.5% for the response factors obtained from ten such solutions. Fourthly, recovery of the degradation products from the drug substance is good in view of the low absolute concentrations present, usually 90-110% of the level added to the BDP ('<0.5% rnlrn). Fifthly, as an arbitrarily-defined criterion, the lowest level of quantification was taken to be that concentration of solution which gave an RSD of less than 10% when injected 5 times. These concentra- tions (in terms of BDP) were found to be: beclometha- sone, 0.025%; beclomethasone 17-monopropionate, 0.05% ; beclomethasone 21-monopropionate, 0.025%.Sixthly, the method demonstrated little or no analyst dependence during application, with good recovery data and over-all reproducibility being obtained (typical RSD of 0.43% when two analysts each carried out five determinations on the same batch of BDP drug substance). Discussion Some discussion of the method development strategy is felt to be necessary. Initial investigations revealed the need for a stationary phase capable of making a major contribution to the selectivity of the chromatographic system. This resulted in the choice of 5 pm Spherisorb Nitrile as the stationary phase. Application of the Simplex method of optimisation was found to be successful, although relatively time-consuming and probably unnecessarily pedantic in the present situation.ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 141 However, the value of this systematic approach to method development was evident and it could prove extremely effective inamorecomplexor unusualsituation.Conclusions An HPLC assay method for the simultaneous determination of BDP, both monopropionates and beclomethasone, has been developed and successfully validated. This method gives good peak shape, has an over-all run time of approximately 5min and gives base-line resolution between each of the four components. Moreover, it is felt that the general chromatographic conditions employed in this method may readily be extended to the determination of BDP (and related impurities of synthesis and degradation products) in formulated presentations.References 1. Berridge, J. C., and Last, P. E., “Automated Analysis-the Expanding Choice,” “Workshop A: Interactive Analytical Method Development by Microcomputer,” Meeting organised by the Royal SocietyofChemistry, Stirling University, 1981. Snyder, L. R., and Kirkland, J . J., “Introduction to Modern LiquidChromatography,”Second Edition, John Wiley,Toronto, Canada, 1979,~. 246. 2. ROYAL SOCIETY OF CHEMISTRY: ANALYTICAL DIVISION THE INTEGRATED APPROACH TO LABORATORY AUTOMATION A review of analytical instrumentation, robotics, laboratory information management systems and laboratory staffing and design to be held at The Dormy Hotel, Ferndown, Dorset October, 23rd-25th 1985 This two-day residential seminar, organised by the Automatic Methods Group, will allow practising analysts and managers and directors responsible for laboratory operations to gain an in-depth appreciation of the impact of the computer revolution on the future of analytical chemistry. Over the past decade the role of the laboratory as a provider of information has not changed substantially. The means of controlling instruments, acquiring data and presenting information has been radically transformed as a result of the reduction in size and cost and of the increasing reliability of computer hardware in concert with computer software developments. The seminar will commence by reviewing analytical instrumentation, examining current technology and likely future developments. Improved control of instruments and networking has allowed substantial progress towards improving data quality but highlighted sample preparation and presentation as one of the remaining major sources of variability. The role that robotics will play in addressing these deficiencies will be reviewed. The intelligence of these systems can be exploited through “standard” interfaces by larger computers responsible for laboratory information mangement systems communicating information via corporate networks. The combined impact of these developments is likely to lead to a radical change in approach to laboratory staffing and design. For further information on this meeting contact Dr. C. J. Jackson, Health and Safety Executive, Occupational Hygiene Laboratory, 403 Edgware Road, London NW2 6LN.

ISSN:0144-557X    

DOI:10.1039/AP9852200135

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

142 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Current Methods in Surfactant Analysis The following are summaries of three of the papers presented at a Joint Meeting of the South East Region and the Microchemical Methods and Special Techniques Groups held on December 6th, 1984, in Kings College, London W.C.2. Some Aspects of Surfactant Analysis W. A. Straw 5 Cheynies Court, 76 Arundel Way, Highcliffe, Christchurch, Dorset BH23 5DX The Analytical Problem Growth in the field of analytical chemistry has been so rapid that it has been difficult to assimilate. Siggia’s broad survey’ admirably indicates the composition and inter-relationships of that field. He points out that in practice, most problems fall into distinct types: hence the need for clearly establishing the relationship between different analytical approaches and their usefulness relative to the type of analytical problem under consideration.In the present context, excellent literature reviews are available,*,3 together with comprehensive texts with emphasis on analysis,&7 quality controls and surfactant biodegradation .9 The value of instrumental techniques is being increasingly recognised, as revealed by Llenado. 10 Isolation A broad spectrum of the requirements for surfactant analysis might range from quality control during manufacture to the measurement of trace amounts in environmental samples; inevitably, some form of pre-extraction will be required. Hitherto, adequate isolation of the surfactant from commercial products in emulsion form was usually achieved by the addition of electrolyte, by centrifugation or simply by the application of heat to destabilise the emulsion.Aqueous based products were usually saturated with potassium sulphate and extracted with butan-1-01. Non-aqueous based products were frequently dissolved or dispersed in 50% ethanol and the non-surface- active matter extracted with low boiling range petroleum spirit. Dry products could be effectively extracted with dry methanol if one wished to avoid a more lengthy extraction with ethanol, followed by another with chloroform. Turning to the separation of components in isolated material, ion-exchange procedures are now well documented11 and appear to be consistently reliable. Obviously, the selection of appropriate resins is important, and in a multi-stage operation, where ampholytes are involved, some form of pH control will be required.In spite of the difficulties experienced by earlier workers in the chromatographic analysis of highly polar, water-soluble surface-active materials, reversed-phase partition on paper impregnated with cetyl (hexadecyl) alcohol acting as the stationary phase allowed resolution of the ClTC18 homologues of n-alkyl sulphates applied from ethanol as a 1% solution. The mobile phase consisted of aqueous ethanol (50-80°/0) saturated with cetyl alcohol. Following a development period of 10-24 h, the paper was dried, immersed in copper(I1) acetate solution and sprayed with Rhodamine 6GB; detergents with spots appearing crimson on a pink background under ultraviolet illumination were thus charac- terised in terms of their RF values.12 Similar procedures revealed six well defined components in proprietary “Teepol ,” and four distinct components in commercial cetylpyridinium chloride, detected with bromocresol green solution.13 Characterisation of Isolated Material Systematic schemes for the qualitative analysis of unknown surfactants, as developed some 30 years ago, depended largely on group identification tests after preliminary Lassaigne sodium fusion to establish the presence or absence of nitrogen, sulphur and phosphorus.14 Typically, one might have distin- guished between anionic sulphonates and sulphates, the former giving precipitates with copper(I1). Alkyl sulphates characteristically yielded ketones on oxidation with acid dichromate, which were recognisable by their odour and by the production of well defined derivatives with 2,4- dinitrophenylhydrazine. Ethoxylates and propoxylates yielded acetaldehyde and propionaldehyde, respectively, when pyro- lysed in the presence of glacial phosphoric acid, a simple colour reaction with sodium nitrosopentacyanoferrate(II1) and mor- pholine being used to detect the volatile aldehydes.Alkylaryl polyether sulphates were readily distinguishable from alkylaryl sulphonates, as the former decolorised aqueous potassium permanganate . The earliest tests for ionic type carried out on aqueous solutions, relied on “ion-association,” i. e., the mutual interac- tion of oppositely charged species, revealed as a turbidity, or by the extraction of a coloured complex with carbon tetra- chloride, chloroform or 1,2-dichloroethane (the “dye transfer” tests).Traditionally, methylene blue (CI 52015) as a zinc-free salt, and sulphonphthalein indicators, e.g., bromophenol blue, seem to have found favour in this connection. Incidentally, Hartley15 first noticed the effects of surfactants on pH indicators, bromophenol blue being changed from purple to pure blue by quaternary ammonium compounds even though the pH of the system was unchanged. The effect occurring at, above or near the c.m.c. can take the form of a colour change, a change in fluorescence, or both, and is similarly shown with Pinacyanol and Rhodamine 6G. Thus we have, in the formal procedure in BS 3762,16 five reagents in a preferred sequence, which are used to establish the ionic character of a 1% aqueous solution of surface-active material adjusted to pH 7k0.5.The surfactant needs to have been recovered from the composite formulated product by ethanol extraction, and freed from soap by dissolution in water, followed by acidification and extraction with light petroleum. Some variants of this scheme are possible, one being designed to recognise ampholytic materials,17 utilising a “reversed pH” approach with suitably buffered methylene blue and bromophenol blue as shown in Table 1. Also, Smith18 has recommended testing to discover whether the substance under investigation will discharge the colour produced with a known surfactant of opposite charge and an appropriate reagent. Thus, to test for an anionic surfactant, an aqueous, alkaline solution of bromophenol blue together with a trace of a cationic surfactant is shaken with chloroform.The sample is then added, and the mixture shaken again. To test for aANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 143 Table 1. Qualitative tests on surfactants for ionic type (adapted from BS 3762: 1964)” Ionic Response Reagent type system Colour Methylene blue pH 4 An CHCl, Blue Bromophenol blue pH 9.2 Cat CHCI3 Blue Ba2+ - phosphomolybdic acid Non Aq Green - Ammonium cobaltothiocyanate Non CHC13 Blue Methylene blue pH 9.2 Bromophenol blue pH 2 yellow ( .1) } Ampho1 CHC13 [ !%ow cationic surfactant, the material is added to acidified methy- lene blue with a trace addition of sodium dodecylbenzenesul- phonate, plus chloroform. A compound which discharges the colour of the chloroform layer in both anionic and cationic tests is an ampholytic surfactant.Other reagents succesfully incor- porated include substituted phenanthridinium and carbocyan- ine derivatives, or organometallic cations derived from 2,2’- bipyridyl or 1,lO-phenanthroline for anionics, and Disulphine Blue VN (CI Acid Blue l ) , methyl orange, and picrate, triiodide, permanganate and perchlorate anions for cationics. Quantitative Analysis Early methods relied on the gravimetric determination of sulphate after hydrolysis of, for example, sulphated oils in boiling, dilute mineral acid. Sulphonated products were more resistant to hydrolysis, and so required more drastic conditions (such as refluxing in orthophosphoric acid at 215 “C). Alkyl- benzene sulphonates were found to yield alkyl phenols on alkali fusion at about 350 “C, which, on bromination, could be determined by using an iodimetric titration procedure for determining the excess bromine in the system.The gravimetric determination of ethoxylated alkyl phenols as their insoluble barium - phosphomolybdic acid “oxonium” complexes, was proposed in 194919 for use in ICI Dyestuffs Division labora- tories at Blackley . Pitter20 has developed a spectrophotometric finish in an analogous system involving ionic calcium, phospho- tungstic acid, concentrated sulphuric acid and hydroquinone, the reddish-purple colour produced satisfactorily obeying the Lambert - Beer laws. The cobaltothiocyanate methods for ethoxylates are well established, using chloroform or benzene as extraction sol- vents, but it is of interest to note the wide variation in composition of reagents proposed by different workers, as set out in Table 2.21-27 The main limitations are interference from cationics, when precipitation may occur, and an inherent insensitivity of the methods towards components of low degrees of ethoxylation.Sodergren28 has successfully used segmented flow col- Table 2. Aqueous ammonium cobaltothiocyanate reagent: composi- tions (g 1-1) Workers Gnamm2’ Wurzschmitt22 Van der Hoeve23 Brown and Hayes24 Kurata25 Be1I26 Long man27 Milwidsky and Gabriels and BS 3762 : 196416 Ammonium Cobalt nitrate thiocyanate hexahydrate 347 174 174 1.4 2.8 28 200 30 620 280 174 2 522 28 30 * * Ammonium thiocyanate is replaced by ammonium chloride (143 g) and potassium thiocyanate (256 g).orimetry (the “Technicon” system) for an automated version of the Longwell and Maniece methylene blue procedure29 for determining anionic surfactants in water, results from manual and automated methods correlating well. Recently, Taguchi and Got030 have proposed the highly coloured bis[2-(2- pyridylazo)-5-diethylaminophenolato]-cobalt(III) ion as a new counter ion for use in the extraction and spectrophotometric determination of traces of colourless ions in water. When applied to the determination of sulphated and sulphonated anionic surfactants, Beer’s law is obeyed over a wide range and the detection limit is approximately 0.2 pg; the method is claimed to be more sensitive than the methylene blue procedure. Wang and Ross31 studied the colorimetric determi- nation of anionic surfactants in water by an Azure A (CI 52005) method, the blue complex being soluble in chloroform with Amax.at 623 nm. Investigating the analysis of C12 and C17 alkyl sulphates with Azure A, Steveninck and Remersma32 found that chloroform extracts the Azure A complex of both species, whereas monochlorobenzene preferentially extracts that of the C17 - Azure A complex. In addition, the Azure A method was found to be much less sensitive to interferences from other anions. Tris( 1,lO-phenanthroline) - iron(I1) (ferroin) has been extensively investigated as an organometallic ion-pairing spe- cies,33 along with a number of related structures, for monitor- ing short-chain surfactants in river and waste waters. Wang and Panzardi,34 seeking to introduce a modified two-phase titration method for the rapid analysis of anionic surfactants in environmental water quality control, have recommended the use of Azure A as a primary indicator, noting an enhanced rate of phase separation with this indicator compared with methylene blue, followed by methyl orange for accurate detection of the end point.Results are expressed as mg 1-1 of Azure A active substances (AAAS). The accuracy and precision attainable in the Azure A methods have not, as yet, been fully investigated. Thus, the two-phase titration procedure35 using as mixed indicator dimidium bromide and Disulphine Blue VS (Acid Blue 1, CI 42045), originally introduced by Holness and Stone36 for qualitative purposes, is regarded very favourably for the quantitative analysis of anionic surfactants, having been thoroughly investigated by Reid and co-workers37 and adopted as an I S 0 method.38 A theoretical treatment of two-phase titration methodology has been published.39 More recently, Li and Rose@ have favoured a different solvent phase, viz., chloroform - 1- nitropropane (2:3 VIV), and a multiple-extraction technique, claiming that better stoicheiometry is thereby achieved when surfactants with less than C12-alkyl moieties are involved.Tsubouchi and Tanaka41 have developed a method for the determination of non-ionic surfactants by two-phase titration, after extraction with 1,2-dichloroethane in the presence of sodium hydroxide and sodium tetraphenylborate. Titration with standard cationic reagent (zephiramine, 2 X M) ensues at pH 9, in the presence of a hydrophobic indicator, Victoria Blue B (CI 44045), up to the end-point shown by a colour change (blue to red) in the organic phase.The method is also applicable when, in addition, a concentration of <1 X 10-4 M of anionic surfactant is present in the sample solution. Similarly, ethoxylates forming “oxonium” ion pairs in aqueous solution with sodium ions and chromophoric picrate anions are extractable into an organic phase, for example, 1,2- dichloroethane, whence determination of the absorbance at 378 nm leads to a satisfactory analysis of typical commercially available nonylphenol ethoxylates in waste water at levels of <1 mg 1-1 with relatively few interferences.42 It is claimed that this method is about eight times more sensitive than one based on a classical cobaltothiocyanate system.Extension of this concept has led to the adoption of potassium picrate as a reagent when investigating systems containing monodisperse and polydisperse ethoxylates, the latter being returned as potassium picrate active substances (PPAS), referred to a suitable standard.43144 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Infrared and Ultraviolet Spectroscopy With a trend towards the increasing diversity of chemical structures within the anionic, cationic and non-ionic types and the dual character of ampholytes at extreme pH values, earlier schemes of identification may be considered to become restrictive. Thus, increasing use has been made of spectro- scopic methods.44 Where an ultraviolet absorbable species is present, spectrophotometry in the 220-300 nm range is a fairly obvious and rewarding choice -45 With regard to infrared spectroscopy, whilst specific absorptions have been utilised, for example, in the characterisation of “active matter” retrieved from formulated detergents either through finger- printing in the 7-11 pm (1500-900 cm-1) range or via search procedures with the aid of a databank,46 spectrograms are occasionally difficult to interpret, the products concerned lacking fundamental groups that give rise to highly distinctive spectra.This is particularly noticeable with alkyltrimethyl- ammonium ions and ethoxylated long-chain alcohols. In particular, the waxy nature of the latter renders the production of bromide discs difficult, and the spectral bands lack definition and are poorly resolved, necessitating modifications to the preparative routine.A specific, quantitative procedure has been developed and successfully applied to the determination of trace amounts of alkylbenzene sulphonates in water supplies and effluents.47 The surface-active species are adsorbed on to activated carbon, desorbed in alkaline benzene - methanol (1+1 VlV), treated with hydrochloric acid to hydrolyse interfering organic sul- phates and phosphates, extracted with petroleum spirit to remove other organic matter and finally extracted into chloroform from which an amine ion-pair complex is isolated by using 1-methylheptylamine. The complex is dissolved in carbon tetrachloride or in carbon disulphide and, after scanning, absorptions are measured near 9.6 pm (1042 cm-1) and 9.9 pm (1010 cm-1).Calibration graphs are required for each laboratory using the entire procedure on suitable refer- encc material. Practically 100% recovery is obtained. A similar technique is available for the determination of biologically “hard” and total active-matter contents,48 the biologically “soft” content being determined by difference. Foam Fractionation and Solvent Sublation Techniques Two of the attractive features of adsorptive bubble separation techniques are their effectiveness in the concentration range that is too dilute for the successful use of most other techniques, and their ease of operation. Thus, foam fractiona- tion can be used for separating surface-active species from aqueous solution, and molecular and ion-flotation for the separation of non-surface-active species such as strontium, lead and cyanides that can be made to associate with various surfactants.There are other non-foaming separation methods, such as bubble fractionation and solvent sublation, where adsorption effects at interfaces are again the basis for concen- tration, but the adsorbed material is removed in another liquid that is immiscible with the bulk solution.49 Wickboldso recommended ethyl acetate in this connection, in the concen- tration of anionic surfactant in surface and potable waters. Because foam separation techniques can concentrate from solutions that are as dilute as 10-10 M in surfactant, their application as concentration techniques seems assured; their high degree of selectivity also suggests that they can also be used as separative techniques.51 Investigating the selectivity of cationic surfactants in the foam separation of anions from aqueous solution, Grieves et aZ.52 noted the incidence of “competitive ion-pairing” involving charge, degree of hydra- tion and structural considerations, when high chloride ion concentration suppressed the availability of the surface-active cation so that few surfactant-containing ion-pairs were formed; the yield of surfactant in the collapsed foam was therefore small when using cetyldimethylbenzylammonium chloride at about 10-5-10-4 M levels, and the recovery of the oxyanions of chromium, molybdenum and tungsten assured.Chromatography (TLC, GLC and HPLC) Thin-layer Chromatography (TLC) Dragendorff‘s reagent (bismuth oxynitrate and potassium iodide in glacial acetic acid) has been used extensively in the analysis of non-ionic detergents and polyglycols as a spray reagent, the colours produced being somewhat dependent on the relative molecular masses of the materials involved,53.54 in biodegradation studies55 and in the Wickbold - Longman procedure,56 in which the resulting precipitate is filtered off and dissolved in ammonium tartrate, whence bismuth is determined by EDTA titration. Gas - Liquid Chromatography (GLC) Fatty alcohols, fatty alcohol ethoxylates and fatty acids are often isolated by acid hydrolysis from formulated products. A wealth of new information, qualitative and quantitative, may be revealed when such isolated “active matter” is subjected to examination by GLC, provided that adequate volatilisation occurs.Fatty alcohols are directly amenable to chromato- graphic analysis, whereas their ethoxylated counterparts are rendered more volatile by silylation with N-(trimethylsilyl) acetamide. The composition of fatty acid mixtures can be determined by examination of their methyl esters derived via diazomethane or the less hazardous reagent, N-methyl-N- nitroso-p-toluenesulphonamide . High-performance Liquid Chromatography (HPLC) Whilst the foregoing rationale is adequate for the quantitative separation of mixtures and homologous series of organic materials, more recent applications of HPLC allow quantita- tive separations to be effected on less volatile materials. For example, various surfactants were separated into their indi- vidual homologues, regardless of their ionic properties, by Nakamura and Morikawa.57 Ion-sensing Electrodes for Surfactants In recent years, considerable interest has been shown in ion-exchange electrodes that are sensitive to ionic surfactants; some of the first electrodes developed used nitrobenzene in which was dissolved an ion-pair complex of an alkylpyridinium alkylsulphate or an alkyltrimethylammonium tetraphenylbor- ate.Thus, for measuring dodecyltrimethylammonium ions down to 10-6 M an electrode can be prepared from dodecyl- trimethylammonium tetraphenylborate; the cation can be measured either directly or potentiometrically using sodium tetraphenylborate as titrant.58 Anionic dodecyl sulphate, tetrapropylenebenzenesulphonate and dioctylsulphosuccinate can be measured down to 10-5, 5 x 10-6 and 1 0 - 6 ~ , respectively, and up to close to the c.m.c. of each species.59 Mixtures of all three may also be determined by potentiometric titration by using a dodecylsulphate electrode for end-point detection. A modified formulation of ion-exchanger incorpo- rated hexadecylpyridinium dodecylsulphate in 1,2-dichloro- benzene” and was used in c.m.c.studies. Such an electrode measured dodecylsulphate ion concentration down to M, in the pH range 4-10. Tetradecylsulphate and hexadecylsulphate ions caused interference. Other techniques suitable for the preparation of surfactant electrodes have been reviewed by Moody and Thomas,61 whilst the widening field for their industrial application has been surveyed by Birch and Cock- croft .62 Reagent Specifications The ever increasing need for a deeper understanding of chemical processes involving surfactants and their closer control, whether for technical, economic or ecological reasons, M,the limit of Nernstian response being 3 XANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 145 ~~ Table 3.Purity specifications for available electrophoresis grades of sodium dodecylsulphate Melting point/”C C12 assay, min. % Free fatty alcohol, max. Yo Chloride as C1, max. % Phosphate as PO,, max. O/O Copper as Cu, max. O/O Iron as Fe, max. 70 Lead as Pb, max. O/O Absorbance 220-350 nm on 1% aq. soln (max.) Absorbance 280 nm on 3% aq. soh (max.) Absorbance 220-250 nm on 3% aq. soh (max.) Electro pure Specially Electrophoresis # 3945* purified # 17473t purityt 204-207 99 99.5 99 0.2 0.2 0.01 0.005 0.01 0.0001 0.0001 0.0002 “ AnalaR” biochemical$ 99 0.02 0.0001 o.oO01 0.0001 0.0002 0.1 0.025 0.1 0.1 * Polyscience Ltd., Northampton.t Biorad Laboratories Inc., Richmond, California. $ BDH Chemicals Ltd., Poole. means that authentic reference standards for use in analysis should be readily available. Reference standards are by no means new, and the evolution of national and international programmes for certification have been reviewed by Cox.63 Within the European Community, the Bureau Communau- taire de Reference (BCR) in Brussels has established liaison with the pharmaceutical field in which coordination is on the basis of the European Pharmacopoeia with its own office for reference materials.64 Perhaps eventually surfactants will receive similar consideration, particularly when the needs have been adequately identified, defined and assessed.In the meantime, acceptable reference materials would seem to include sodium bis(2-ethylhexyl)sulphosuccinate and sodium dodecyl sulphate (anionics) , benzethonium chloride (Hyamine 1622, Rohm and Haas, p-tertoctylphenoxyethoxyethyl- dimethylbenzylammonium chloride monohydrate) (cationic), and isooctylphenoxypolyethoxyethanol (Triton X-100, Rohm and Haas, scintillation grade) (non-ionic). Recently, electrophoresis reagent grade sodium dodecyl sulphate has been offered commercially (Table 3). Aiming for significantly reduced levels of ultraviolet absorbing impurities, free fatty acids and chlorides, the manufacturers claim to thus minimise the incidence of electrophoretic anomalies and side reactions, particularly in biochemical analysis.Within the European Colour Fastness Establishment (ECE), a consortium representing colour fastness test interests in Western Europe, agreement has been reached on the composition of a reference detergent (to be known as ECE Reference Detergent, otherwise described as Colour Fastness Test Detergent 77) representative of domestic detergents available in Europe, except that it does not contain sodium perborate. This follows from proposals in the UK to adopt, as British Standards, washing tests in which the use of a reference detergent and sodium perborate are mandatory, following the acceptance in principle, by I S 0 in 1977, of a new series of tests for determining colour fastness to washing.65.66 References 1.2. 3. 4. Siggia, S., “Survey of Analytical Chemistry,” McGraw-Hill, New York, 1968. Llenado, R. A,, and Neubecker, T. A., Anal. Chem., 1983,55, 93R. Longman, G. F., Talanta, 1975, 22, 621. Rosen, M. J., and Goldsmith, H. A., “Systematic Analysis of Surface-active Agents,” Second Edition, Wiley-Interscience, London, 1972. Hummel, D., “Identification and Analysis of Surface-active Agents,” Translated by Wulkow, E. A., Wiley, New York, 1964. 5 . 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. 36. 37. 38. Schick, M. J., Editor, “Nonionic Surfactants,” Arnold, Lon- don, 1967. Cross, J ., Editor, “Anionic Surfactants-Chemical Analysis,” Dekker, New York, 1977. Milwidsky, B. M., and Gabriel, D. M., “Detergent Analysis, ” Godwin, London, 1982. Swisher, R. D., “Surfactant Biodegradation,” Dekker, New York, 1970. Llenado, R. A., and Jamieson, R. A., Anal. Chem., 1981,53, 174R. Longman, G. F., “The Analysis of Detergents and Detergent Products,” Wiley-Interscience, London, 1975, Chapter 5. Franks, F., Nature, 1955, 176, 693. Franks, F., Analyst, 1956, 81, 390. Van der Hoeve, J. A., Recl. Trav. Chim. Pays-Bas Belg., 1948, 67, 649. Hartley, G. S., Trans. Faraday SOC., 1934, 30, 444. BS 3762: 1964. “Methods of Sampling and Testing Detergents,” Part 2, Section A. Straw, W. A., “Laboratory Notes for Characterisation and Analysis,” Undergraduate School of Studies in Colour Chemistry and Colour Technology, University of Bradford, Bradford, 1979.Smith, W. B., J . SOC. Cosmetic Chem., 1963, 14, 513. Oliver, J . , and Preston, C., Nature, 1949, 164, 242. Pitter, P., Chem I d . , 1966, 1217. Gnamm, H., “Die Losungs-u. Weichmachungsmittel,” Wis- senschlaftliche Verlag, Stuttgart, 1941. Wurzschmitt, B., Z . Anal. Chem., 1950, 130, 105. Van der Hoeve, J. A., J . SOC. Dyers Col., 1954, 70, 145. Brown, E. G., and Hayes, T. J., Analyst, 1955, 80, 755. Kurata, M., J . Japan Oil Chem. SOC., 1955, 4, 293. Bell, M., “Surface-active Agents,” Glovers Chemicals, Leeds, 1966. Longman, G. F., “Analysis of Detergents and Detergent Products,” Wiley-Interscience, London, 1975, p. 347. Sodergren, A., Analyst, 1966, 91, 113. Longwell, J., and Maniece, W.D., Analyst, 1955, 80, 167. Taguchi, S., and Goto, K., Talanta, 1980, 27, 289. Wang, L. K., and Ross, R. G., Int. J . Environ. Anal. Chem., 1976,4, 285. Steveninck, J. V., and Riemersma, J. C., Anal. Chem., 1966, 38, 1250. Waters, J . , and Taylor, C. G., in Cross, J., Editor, “Anionic Surfactants-Chemical Analysis,” Dekker, New York, 1977, Chapter 5. Wang, L. K., and Panzardi, P. J., Anal. Chem., 1975,47,1472. Herring, D. E., Lab. Pract., 1962, 11, 113. Holness, H., and Stone, W. R., Analyst, 1957, 82, 166. Reid, V. W., Longman, G. F., and Heinerth, E . , Tenside, 1967, 4, 292; 1968, 5 , 90. I S 0 2271 : 1972. “Determination of Anionic-active Matter- Direct Two-phase Titration Procedure.”146 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49.50. 51. 52. 53. Han, K. W., Tenside, 1966, 3,265. Li, Z., and Rosen, M. J., Anal. Chem., 1981, 53, 1516. Tsubouchi, M., and Tanaka, Y., Talanta, 1984, 31, 633. Favretto, L., and Tunis, F. , Analyst, 1976, 101,198. Favretto, L., Stancher, B., and Tunis, F., Analyst, 1979, 104, 241. Cross, J. T., Analyst, 1965, 90, 315. Reid, V. W., Alston, T., and Young, B. W., Analyst, 1955,80, 682. Sadtler Research Labs Inc., “Sadtler Standard Spectra,” Heyden, London, 1970 to date. Sallee, E. M., Fairing, J . D., Hess, R. W., House, R., Maxwell, P. M., Melpolder, F. W., Middleton, F. M., Ross, J . , Woelfel, W. C., and Weaver, P. J., Anal. Chem., 1956, 28, 1822. Ogden, C. P., Webster, H. L., and Halliday, J., Analyst, 1961, 86, 22. Lemlich, R., Editor, “Adsorptive Bubble Separation Tech- niques,” Academic Press, New York, 1972.Wickbold, R., Tenside, 1973, 10, 180. Somasundaran, P., Sep. Science, 1975, 10, 93. Grieves, R. B., Charewicz, W., and The, P. J . W., Sep. Science, 1975, 10, 77. Ginn, M. E., Church, C. L., and Harris, J . C., Anal. Chem., 1961, 33, 143. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Patterson, S. J. , Hunt, E. C., and Tucker, K. B. E., in Shallis, P. W., Editor, “Proceedings of the SAC Conference, Notting- ham, 1965,” Heffer, Cambridge, 1965, p. 339. Ministry of Technology, “Report of the Government Chemist, 1965,” HM Stationefl Office, London, 1966, p. 107. Longman, G. F., “The Analysis of Detergents and Detergent Products,” Wiley-Interscience, London, 1975, p.513. Nakamura, K., and Morikawa, Y., J. Am. Oil Chem. SOC., 1982,59, 64. Gavach, C., and Seta, P., Anal. Chim. Acta, 1970, 50, 407. Gavach, C., and Bertrand, C., Anal. Chim. Acta, 1971, 55, 385. Birch, B. J., and Clarke, D. E., Anal. Chim. Acta, 1973, 67, 387. Moody, G. J., and Thomas, J . D. R., Lab. Pract., 1978, 27, 285. Birch, B. J., and Cockcroft, R. N., Ion-select. Electrode Rev., 1981, 3, 1. Cox, J. D., Chem. Znd., 1975, 420. Lauer, K. F., Chem. Ind., 1975,421. BS1006: C06: 1981. “Colour Fastness to Domestic and Commercial Laundering”. Dawson, P. R., J . SOC. Dyers Col., 1981, 97, 184.ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 147 agents requires the use of the HPIC-AS7 anion-exchange column. The eluent used is nitric acid, which has a strong affinity for the exchange sites and is able to displace the multivalent ions.Conductivity is not a suitable means of detection for these ions in a nitric acid matrix. The detection method used involves post-column derivatisation with iron(II1) perchlorate followed by ultraviolet - visible detection at 330 nm. The same column, using a lower concentration, can be used for analysis of the polyphosphonates. For the weakly acidic anions, such as borate - perborate, carbonate and silicate, the most suitable method of analysis involves exclusion chromatography. By using the exclusion column, coupled again with chemical suppression, components such as perborate and carbonate can be detected and quanti- fied in a formulated surfactant matrix. The silicate ion is again separated on the exclusion column, but is detected by post-column derivatisation and ultraviolet - visible measure- ment.The derivatisation agent used is sodium molybdate and there is no interference from phosphate species, as would occur without separation. Analysis of Surface Active Organics (Anionic and Cationic Surfactants) Analysis of hydrophobic species, such as surface active agents, requires the use of the technique known as mobile phase ion chromatography or MPIC. This technique is closely allied to ion pairing chromatography. Various mechanisms have been proposed by Horvath et aZ.3 and Huber, Liao and Ki~singer.~ The mechanism which best fits the practical findings in MPIC has been proposed by Biddigmeyer and P ~ h l . ~ The resins used in MPIC are neutral macroporous styrene divinyl benzene beads.The retention process is dominated by the nature of the interface between the (hydrophobic) station- ary and (hydrophilic) mobile phases. At the liquid - solid interface between the two phases there exists a high surface tension. Because of this high surface tension the resin surface has an affinity for mobile phase components which reduce surface tension. These include: non ionics with high dipoles (e.g., polar organic solvents); ionic surfactants (e.g., alkyl sulphonates and quaternary ammonium compounds); and ionic surfactant counter ions. In MPIC surface active cations and organic modifier (e.g., acetonitrile) compete for the resin surface. If the MPIC system is being used for the analysis of non-surface active anions, these remain in the outer electronic layer. Where surface active anions are present they will be included in the inner region of the electronic double layer.Selectivity is based on the hydrophobic nature of the surfactant. The greater the hydrophobic character of the molecule, the longer the retention time. The introduction of organic solvents or modifiers into the system provides competition for the resin surface, resulting in the displacement of some ion pair reagent and hence a reduction in retention time. In practice the following par- ameters are used to control retention time and selectivity: the type of pairing agent; the concentration of the pairing reagent; the type of organic modifier used; the concentration of the organic modifier; the pH and the temperature of the liquid phase.The control of these parameters is discussed in Dionex Technical Note 12.6 After separation the surfactants can be detected by suppressed conductivity, ultraviolet - visible or electrochem- ical detectors. In certain instances it is advantageous to use two detectors in series. This will be illustrated in later examples. With linear alkyl sulphonates, separation can be achieved by using progressively larger ion pair reagents, with correspond- ingly higher levels of organic modifier. For example, 10 mM ammonia solution with 10% acetonitrile, or 2 mM tetrapropyl- ammonium hydroxide solution with 20% acetonitrile, or 2 mM tetrabutylammonium hydroxide solution with 28% acetonitrile will all provide a separation. For the higher relative molecular mass alkylbenzene sulpho- nates resolution is not base line; separation into progressively increasing chain lengths with further resolution to show the branch chain derivatives is possible.In general, the alkyl sulphates are more hydrophobic and therefore show longer retention than the alkyl sulphonates. Ion chromatography is a valuable technique in the analysis of surfactants and surfactant-based systems. When sulphosuccinic acid and its octyl esters are separated a step-gradient eluent is used, 2 mM tetrabutylammonium hydroxide with 35% aceto- nitrile for the acid plus monoester changing to 2 mM tetrabutyl- ammonium hydroxide with 70% acetonitrile for the diester. A low level of sodium carbonate improves the peak shape in this example. Use of the combination of suppressed conductivity with ultraviolet - visible measurement can show that there is no aromatic character in a surfactant such as an alkyl sulphonate.All of the examples so far have involved the analysis of anionic surfactants. However, by using ion pair reagents such as hydrochloric or perchloric acid and hexane- or octanesul- phonic acid, amines and particularly quaternary ammonium compounds can be analysed. Also, ions such as tetrabutyl- ammonium, dialkyldimethylammonium, imidazolinium and alkyldimethylbenzylammonium have all been successfully separated on the MPIC system. 1. 2. 3. 4. 5. 6. References Small, H., Stevens, T. S., and Bauman, W. C., “Novel Ion Exchange Chromatographic Methods Using a Conductimetric Detector,” Dow Corporation, Midland, MI, USA, 1972.Dixon, J. P., “Modern Methods in Organic Microanalysis,” pp. 18-22. Horvath, C., Melander, W., Molnar, I., and Molnar, P., Anal. Chem., 1977, 49,2295. Kraak, J. C., Jonker, K. M., and Huber, J . F. K., 1. Chromatogr., 1977, 142, 671. Pohl, C., “MPIC Theory and Separation,” Dionex Corporation, Sunnyvale, CA, USA, 1982. Dionex Corporation, Technical Note 12R, Sunnyvale, CA, USA, 1982.148 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 reversal of nuclear magnetic moments. Every nucleus with a spin possesses a magnetic moment, and nearly all elements in the periodic table have a nucleus with a spin. The major advantage of NMR in surfactant analysis is the quantitative information that the technique provides on the molecular structure of the sample,’ and hence NMR can be used for both compound identification and quantification. Analytical methods can therefore be developed without standards, or single analyses may be performed without prohibitive back- ground research costs.The major nuclei studied in suifactant analysis are hydrogen (IH), carbon (13C) and phosphorus (31P). 1H NMR is the longest established nucleus and collections of surfactant lH NMR spectra are available.2.3 More recently 13C NMR has played a larger role in both the identification of unknowns and quantitative analysis. No collection of 13C NMR spectra of surfactants is available at present. Typical examples of the use of 13C NMR are the identification of isomers in oxoalcohol ethoxylates,4 and the analysis of the products of alkene sulphonation .5 Quantitative Analysis Using 13C NMR Amines and quaternary salts are important in the production of fabric softeners.The primary method of analysis of amines is potentiometric titration: a 1H NMR method6 can also give the ratio of primary, secondary and tertiary amines. Quantitative 13C NMR expands the information obtained by resolving the different types of secondary and tertiary amine present.’ The quantitative nature of NMR also avoids the need to use arbitrary relative molecular masses when analysing unknown samples. Analysis of quaternary ammonium salts is particularly difficult by techniques such as LC, whereas quantitative 13C NMR provides a rapid, non-destructive analysis8 of mixtures of salts. The identification of unknown compounds is aided by the use of substituent chemical shift parameters for tetraalkyl- ammonium ions,g which allows the estimation of chemical shifts in postulated structures.Linear alkylbenzene sulphonates are very common surfac- tants, prepared by the sulphonation of an alkylbenzene. The distribution of phenyl groups on the alkyl chain can be measured by quantitative 13C NMR10.11 for both the alkylben- zene and the product sulphonate. The NMR method is an improvement on the current chromatographic methods,12 as the NMR method resolves and identifies all of the isomers; Fig. 1 shows a typical 13C NMR spectrum. 1H NMR can be used to measure the average size of the alkyl group. Solids NMR of Surfactants High resolution NMR of solids using cross polarisation (CP) and magic angle spinning (MAS) is possible on commercially available equipment; nuclei such as 13C, 27Al, 21Si and 31P can be studied using equipment not much more complex than a standard FTNMR spectrometer. A major problem with CP/MAS NMR is quantitation of the spectra.13 A good example of the use of solids NMR for surfactants is the examination of phosphate species in the solid state.14 L t5 I 100 6, p.p.m.0 Fig. 1. A 50-MHz 13C NMR spectrum of a commercial linear dodecyl benzenesulphonate. The alkyl carbon (Y to the phenyl group in each isomer is marked with the number of that isomer, except peak 6’, which is (Y to the substitution (peak 6’ is used to split the intensity of peak 5 + 6) Fig. 2 shows the 31P MAS spectrum of a detergent powder examined in a pulse and collect experiment.A significant amount of the signal intensity resides in the spinning sidebands, which complicates the analysis. Sideband suppression experi- ments can be used, but these lose the intensity that is in the sidebands, therefore 2-D solids NMR or factor analysis15 must be used in order to obtain the intensity for each species. Fast Atom Bombardment Mass Spectrometry Many surfactant molecules are not amenable to electron ionisation (EI) or chemical ionisation (CI) mass spectrometry without the use of derivatisation to make the sample volatile. Fast atom bombardment (FAB) ionisation16J7 is a recently introduced technique, which allows the direct examination of I I , , I I I 1 1 1 1 , 1 1 1 1 1 1 1 1 1 1 1 100 0 -100 6, p.p.m. Fig. 2. A 31P solids NMR spectrum of the phosphates in a commercial low foam washing powder.(Shifts referenced to H3P04)ANALYTICAL PROCEEDINGS, MAY 1985. VOL 22 149 involatile compounds, including salts. Also, thermally labile compounds can be successfully ionised. The exact mechanism by which FAB ionises the sample is still a subject of debate, but the over-all picture is simple. An atom beam (commonly xenon atoms) is directed at the surface of the sample, which is held in an involatile matrix. Ionisation then takes place by a momentum transfer related mechanism. The involatile matrix plays an important part in the ionisation process, replenishing the surface damaged by ionisation. Without the matrix FAB spectra are short lived. The choice of matrix materials is large,18 typical examples being glycerol and thioglycerol.The sample must be soluble in the matrix. The FAB ionisation process gives rise to both positive-ion and negative-ion spectra, without any changes to atom beam conditions. Examples of the use of FABMS in the analysis of anionic surfactants19 are the measurement of the homologue distribu- tion in the alkyl groups of alkyl sulphates, sulphonates and alkylbenzene sulphonates, and the measurement of both the alkyl group homologue distribution and the distribution of the number of ethoxylate units in alkyl ether sulphates. Other examples are analysis of cationic quaternary amines2O and the distribution of the number of ethoxylate (or propoxylate) units in alcohol ethoxylates (or propoxylates). A number of features of FABMS require care when interpreting results; matrix effects play a major part in the ionisation process and suppression of the spectra of some components is possible.FABMS spectra can show variable fragmentation patterns. Quantitation of FAB spectra is best performed by using heavy isotope labelled internal standards. I wish to acknowledge the help of Dr. J. Scrivens (ICI plc) in the preparation of the FABMS part of this work. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15, 16. 17. 18. 19. 20 * References “Proton and Carbon-13 NMR Spectroscopy,” Abraham, R. J . , and Loftus, P., Heyden, London, 1978. Konig, H., in Cross, J . , Editor, “Anionic Surfactants- Chemical Analysis,” Marcel Dekker, New York, 1977. “Surface Active Agents, 60 MHz Proton NMR,” Sadtler Standard Spectra, Philadelphia, PA, USA, 1975.Auf der Heyde, Von W., Tenside, 1981, 18, 265. Bayer, J. L., Canselier, J. P., and Costro, V., J. Am. Oil Chem. SOC., 1982,59,458. Mozayeni, F., Appl. Spectrosc., 1979,33, 520. Mozayeni, F., Plank, C., and Gray, L., Appl. Spectrosc., 1984, 38, 518. Fairchild, E. H . , J . Am. Oil. Chem. SOC., 1982, 59, 305. Hart, D . J . , and Ford, W. T., J. Org. Chem., 1974,39, 363. El-Emary, M., and Morgan, L. O., J. Am. Oil Chem. SOC., 1978, 55, 593. Wainai, T., Kanemoto, H., and Mashimo, K., Bunseki Kagaku, 1983,37, T123. Campbell, W., Personal Communication. Packer, K. J . , Harris, R. K., Kenwright, A. M., and Snape, C. E., Fuel, 1983, 62, 999. Grimmer, A . R., and Haubenreisser, U . , Chem. Phys. Lett., 1983, 99, 487. Korms, D. W., and Waugh, J. S., Anal. Chem., 1983,55,633. Barber, M., Bordoli, R. S., Sedgwick, R. D., andTyler, A . N., Chem. Commun., 1981, 325. Barber, M., Bordoli, R. S., Elliott, G. J . , Sedgwick, D., and Tyler, A . N., Anal. Chem., 1982, 54, 645A. Gomer, J . L., Paper presented at 13th BMSS Conference, Warwick, 1983. Lyon, P. A . , Stebbings, W. L., Crow, F. W., Tomer, K. B . , Lippstren, D . L., and Cross, M. L., Anal. Chem., 1984,56,8. Cotter, R. J . , Hansen, G . , and Jones, T. R.,Anal. Chim. Acta, 1982, 136, 135. ROYAL SOCIETY OF CHEMISTRY: ANALYTICAL DIVISION A Meeting has been arranged on THE AUTOMATED ANALYSIS OF IONS IN SOLUTION to be held at The University, York on Wednesday 25th to Friday 27th September, 1985 This symposium, which is being organised jointly by the Automatic Methods Group and the North East Region of the Analytical Division of the Royal Society of Chemistry, will consider the application of a wide range of automated analytical techniques (both wet chemical and chromatographic) to the analysis of ions in solution. The symposium will start with lunch on Wednesday, September 25th, and finish with lunch on Friday, September 27th. Sessions on spectrophotometric, electroanalytical, conventional chromatographic and combination chromat- ographic methods have been organised and will be introduced by noted Keynote Speakers. An exhibition of appropriate analytical instrumentation is being organised. A varied social programme has been arranged for each evening of the symposium and will include visits to the National Railway Museum and the Viking Museum. The registration fee, which will also cover light refreshments, lunch and the evening social programme, is f60for RSC members, €90 for non-members and €30 for retired members or students. Accommodation will be available in the University Halls of Residence, and an additional fee will be charged for overnight accommodation, dinner and breakfast. Further information can be obtained from Dr. CIive Jackson, Health and Safety Executive, 403 Edgware Road, London NW2 6LN.

ISSN:0144-557X    

DOI:10.1039/AP9852200142

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

150 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Equipment News Spectrophotometers The Ultrospec I1 is an ultraviolet - visible single-beam instrument which offers all the major features of its predecessor, the Ultrospec, but has completely redesigned electronic circuitry and a new optical system, giving it a greater photometric range. The absorbance values are linear to 3.0 AU, the stray light performance is better, the response faster and the stabil- ity good; it takes less than 1 s to give a stable reading from a sample. Among its features is peak check facility; with a simple key operation Ultrospec I1 will search around the chosen wavelength to confirm the precise point of maximum absorbance or minimum transmission for any samples. A range of software, for functions such as wavelength scanning and reaction rate monitoring, is available for use with Apple and Hewlett-Packard microcomputers.Another instrument, the Novaspec, is a simple visible spectro- photometer suitable for the teaching lab- oratory. It offers automatic wavelength calibration at switch-on and microproces- sor controlled selection of correct filter combinations. A text-book and wall chart illustrating the principles of spectropho- tometry are also available. LKB Biochrom, Cambridge. Infrared Analyser The PSA 402 process infrared analyser is a single-beam, dual-wavelength instru- ment with a solid-state detector. It offers high tolerance to sample contamination, insensitivity to shock and vibration and long-term calibration stability. Optional function boards include four level alarms, auto zero, dual range and isolated 4-20 mA output signal. A digital direct reading meter, comprehensive self diagnostics capability and lineariser are standard features, and options include pressure and temperature compensation for sam- ple variations.Applications include measurement of carbon dioxide, carbon monoxide, water and hydrocarbons from low p.p.m. to per cent. levels. The PSA 402 has CEGB approval for continuous measurement of carbon dioxide in air. Servomex Ltd., Crowborough, Sussex TN6 3DU. Spectrum Analyser Rental The Tektronix 494P instrument has been introduced on rental terms. It provides an input frequency range from 10 kHz to 325 GHz, a minimum resolution band width of 30 Hz plus counter accuracy tuning and an internal microwave signal counter.Tuning accuracy is +45 Hz up to 7 GHz and no more than k480 Hz at the full 325 GHz. The 494P provides complete inter- activity over the IEEE 488 interface bus Tektronix 494P spectrum analyser plus direct plot facility. Also available is the Tektronix OF152 portable optical fibre cable tester, a time domain reflec- tometer for 1300 nm multi-mode cables. It is capable of 1 m resolution at a range of 60 km. Cable breaks can be measured through a maximum of 35 dB of cable loss and splices detected to kO.l dB through 12.5 dB of one-way cable loss. The instrument is portable. Rental Electronics, 7 Arkwright Road, Reading, Berkshire RG2 0LU. Spectrophotometer Software Two software packages, GRAPHICS and KINETICS, are available for the makers’ Lambda 7 double-beam ultraviolet - visible spectrophotometer with pre- monochromator.With the GRAPHICS soft- ware spectra can be stored in up to six different memory files, each of which can be addressed independently for automatic viewing on the screen or copying to the printer - plotter. Spectra can be added or subtracted, and multiplication factors can be applied for comparison of data. Deri- vative spectra from stored absorbance or transmittance data can also be calculated. A cursor is used to display wavelength and photometric values, and small por- tions of a spectrum can be expanded to full scale. By using the enzyme kinetics facility, lag times, number of data points and intervals between data points (which can be as small as 0.01 min) can be selected. An enzyme factor allows units of enzyme activity to be calculated.The software calculates the delta absorbance value. Standard deviation of the data points from a straight line is included as well as a linearity factor based on the slope of the reaction. An update kit is available to upgrade existing Lambda 7 instruments. Perkin-Elmer Ltd., Post Office Lane, Beaconsfield, Buckinghamshire HP9 1QA. Scintillation Cocktails Two new cocktails have been added to the Scintran range. Fluoran-HV has been developed to accommodate a diverse range of aqueous and non-aqueous sam- ples. Cocktail EX is xylene based and is suitable for aqueous and non-aqueous samples; it complements the existing range of Cocktails 0, T and W. BDH Chemicals Ltd., Broom Road, Poole, Dorset . Thermal Desorber - Autosampler for Gas Chroma tograp h y The TDAS 5000, for use with the makers’ Mega and 4000 Series gas chromato- graphs, allows the fully automatic desorb- ing of sample materials trapped in Tenax filled sample tubes, and their subsequent injection and GC analysis.The basic equipment will accept 30 sample tubes for sequential analysis; a 50-sample option is also available. The TDAS 5000 will oper- ate equally well with glass or fused silica colums or, if required, with packed col- umns. It is also available for interface with the makers’ HEC 960 laboratory com- puter. Erba Science (UK) Ltd., HeadlandsANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 15 1 Trading Estate, Swindon, Wiltshire SN2 6JQ. Chromatograph Graphics A new graphics option for the makers' chromatograph control module (CCM) and Model 301 computing integrator allows simultaneous plotting of two chan- nels of integration on the visual display in real time.Chromatograms can be dis- played in condensed or expanded modes. Gradient profiles can also be displayed in real time together with the chromato- gram. When a re-plot is performed the user can zoom on a portion of the chromatogram and then step through an enlarged view of the chromatogram. Single or groups of peaks can be selected and integrated. Screen editing features include line, point and block drawing routines. Peaks of interest can be manu- ally named or marked. The screen image can be fed to the printer - plotter and/or stored on a floppy disc. Multi-task facili- ties allow graphic plotting to be under- taken in background mode while the user is, for example, running a BASIC program or editing files in foreground. Laboratory Data Control (UK) Ltd., Milton Roy House, High Street, Stone, Staffordshire ST15 8AR.Column Inlet Liners for Gas Chromatography The glass PureCol liner, when inserted into the inlet of a glass GC column, will trap non-volatiles, and when it is contami- nated the liner can easily be replaced. Two sizes are available: the larger fits 4 mm i.d. glass columns that have 7 cm of straight tubing at the inlet end; the smaller fits 2 mm i.d. glass columns with chamfered inlets and 7 cm of straight tubing at the inlet end. Supelchem (R. B. Radley and Co. Ltd.), London Road, Sawbridgeworth, Hertfordshire CM21 9JH. Ion Chromatography System A new system featuring the conducto- Monitor I11 conductivity detector rou- tinely delivers low p.p.b.detection of common anions and cations. Totally modular, the system includes a Rheodyne sample injection valve and all necessary plumbing for ease of setting up. A wide zero suppression range (k 100% of range) is featured, electronically suppressing the background conductivity of eluent buf- fers. The cell temperature is actively controlled for base-line stability. Flow- rates range from 0 to 10 ml min-1, the sensitivity range is 0.1 yS-10 ms and high/low pressure limits are settable with automatic pump shutdown. The system can be operated manually or automatic- ally. Laboratory Data Control (UK) Ltd., Milton Roy House, High Street, Stone, Staffordshire ST15 8AR.Columns for Ion Chromatography The Hamilton PRP-X100 is a resin-based anion column which can be used exclu- sively in the non-suppressed mode and with up to 100% organic modifier. There is virtually no restraint on the columm eluent range (pH 1-13). The column can be used for the rapid analysis of a wide range of anions, including fluoride, bro- mide, chloride, cyanide, nitrite, sulphate and phosphate, and it can separate borate and silicate. The column is available in three sizes: 100, 150 and 250 mm. V. A. Howe and Co. Ltd., 12-14 St. Ann's Crescent, London SW18 2LS. Solvents for HPLC The HiPerSolv range of solvents consists of sixteen high purity solvents available in 2.5- and 1.0-1 packs. BDH Chemicals Ltd., Broom Road, Poole, Dorset. Columns for HPLC The Supelcosil 3.3 cm x 4.6 mm, 3 ym silica fast columns have been designed for separations requiring only moderate col- umn efficiency (4000 plates or less).They are especially useful for running rapid gradient analyses during method develop- ment. Supelchem UK (R. B. Radley and Co. Ltd.), London Road, Sawbridgeworth, Hertfordshire CM21 9JH. Elemental Analyser The CHN rapid analyser has been further developed. It is microprocessor- controlled and is not restricted to opera- tions in the micro range of sample sizes; sample masses can be as high as 200 mg, with the advantage that inhomogeneous samples can be examined. An automatic sample magazine allows up to 49 samples to be pre-loaded. Analyses take as little as 10 min each. A dedicated microprocessor and interface, together with a standard program, allow the unit to be operated overnight, providing a print-out of sample details including sample numbers, masses, measured values and percentage composition.Lower detection limits are 10-3 mg absolute for nitrogen, 5 x 10-4 mg for carbon and 10-4 mg for hydrogen. Heraeus Equipment Ltd., Unit 9, Wates Way, Brentwood, Essex CM15 9TB. Helium Leak Detector The HLT 100 portable helium leak detec- tor is expressly designed to locate leaks in vacuum lines, individual components or fully assembled systems. An air-cooled turbo-molecular pumping system makes the unit ready for use in 3 min. Liquid nitrogen is not required. The unit features automatic sequence control and 11 sensi- tivity ranges. It is capable of detecting and measuring leaks from the very coarse to the very fine (around 10-10 mbar 1 s-1).Balzers High Vacuum Ltd., North- bridge Road, Berkhamsted, Hertford- shire HP4 1EN. Multi-point Sampling System for Carbon Dioxide Measurement The MPS is based on the APBA 200E series of instruments. Using infrared absorptiometry the APBA 200E monitors the carbon dioxide concentration con- stantly, whilst the MPS unit automatically sequences through the sample points, a maximum of ten of which can be accom- modated in each unit. The measurement ranges available are CL2000 p.p.m., CL3000 p.p.m., 0-1% and 0-5'/0 C02. Features include separate alarm levels for individual sample points, adjustable dwell times from 30 to 90 s, 4-20 mA propor- tional output for continuous control pur- poses, RS 423 interface, aerosol contain- ers for easy calibration of the analyser and low maintenance requirement.Horiba Instruments Ltd., 5 Harrowden Road, Brackmills, Northampton NN4 OEB . pH Meter When the CG 832 microprocessor pH meter is switched on it indicates whether the last measurement was in pH, mV or "C and automatically sets to this function. All calibration data for the pH electrode are stored in the memory and retained for years. The instrument registers which buffer solutions were used last time and indicates the corresponding buffer values. Temperature tables for 14 buffer solu- tions are held in store. Settings cannot be altered inadvertently. A pH combination electrode with integral temperature probe facilitates measurements. Schott-Gerate GmbH, Hattenberg- strasse 10, D-6500 Maintz, West Ger- many.Electrodes A new conductivity cell, CDC364, is designed to fit Radiometer electrodes stand and sampler assemblies including El80 Anglepoise, VM'A80 and SAC8O. The latter makes it possible to perform fully automatic conductivity measure- ments with the CDM83 conductivity meter on up to 20 samples. The Radi- ometer copper Selectrode, F1112Cu, has been improved by the use of a PTFE body; the new construction incorporates a pressure-filled CuSe crystal, which avoids the use of an adhesive. A new antimony electrode has been launched; it has a PTFE body construction, which is highly sensitive to pH changes and can be used in environments unsuitable for glass elec- trodes. V. A. Howe and Co. Ltd., 12-14 St. Ann's Crescent, London SW18 2LS.pH Meters A range of Buch and Holm instruments consisting of a process controller, a con- ductivity controller and an LED pH meter152 is available. The pH and conductivity controllers are compact modules. Maxi- mum and minimum levels can be set by thumbwheel switches. In the on - off mode the modules can operate all types of motor driven pumps or solenoid valves. A pulse-frequency mode can be used with electromagnetic feed pumps. Automatic temperature compensation is incorpor- ated. The JK9100 bench LCD pH meter is powered by a 9-V battery or an optional 9 V mains adapter. Suitable for measuring redox or conductivity, the instrument has a resolution of 0.01 pH or 1 mV. Features include a hold switch which fixes a reading for 30 s, manual temperature compensa- tion and slope control.Northern Technical and Chemical Ser- vices, 331 East Prescot Road, Liverpool L14 2DD. Particle Size Analysis for Dry Powders The 2600D and 2600HSD analysers can now be equipped with a dry powder feeder accessory, which disperses the powder and presents it to the analyser in its dry form. Particles in the size range 0.5-300 ym can be measured; with low- ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 blood platelet count. It has a throughput of nearly 80 samples h-1. The S880 with. CASH (Coulter Automatic Sample Handling) can be supplied to any labora- tory using pierceable collection tubes. The provision of a fan-fold printer allows sample results to be printed as soon as they are available. With the Haematology AccuComp the S880 will give a five- element quality control programme that is able to check the many factors influencing the results obtained from a blood speci- men.In addition, the AccuComp pro- vides the facility to print or store results with full patient identification for review at any time. Coulter Electronics Ltd., Northwell Drive, Luton, Bedfordshire LU3 3RH. Balances Three precision balances, the EB60, EB300 and EB3000, offer capacities of 60 g, 300 g and 3000 g with 20 mg, 0.1 g and 1 g resolution, respectively. A rechargeable battery option is available, giving eight hours’ continuous operation. Another option is an RS232C serial inter- face. The display offers gram or ounce Malvern Instruments 26000 particle size analyser density materials the upper limit may be considerably higher.A typical measure- ment takes only 10 s and requires 1-5 cm3 of sample. Malvern Instruments Ltd. , Spring Lane South, Malvern, Worcestershire WR14 1AQ. Haematology Analyser The Counter Model S880 is a fully auto- mated instrument offering an 8-parameter profile including a whole readings and a full range tare facility is available. A new ticket printer has also been introduced. Easily interfaced with the makers’ entire range of Electroscole balances, it is a calculator-sized thermal printer, which can print mass or quantity with the sequential number and total, maximum, minimum, average and stan- dard deviation of a series of weighings. Salter Industrial Measurement Ltd., George Street, West Bromwich, West Midlands B70 6AD. Rotary Shaker The model TR table-top shaker devel- oped by Infors AG features a silent electromagnetic drive, consisting of three coils energised in turn to rotate the table.The latter is mounted on three eccentric bearings, which, apart from the flywheel, are the only moving parts. In conjunction with the appropriate Infors hoods and trays the rotary shaker can be used as an incubator shaker. F. T. Scientific Instruments Ltd., Station Road, Bredon, Tewkesbury, Gloucestershire GL20 2HH. Coupling System for Glass Apparatus A flexible screwthread adapter coupling has been developed for the makers’ SVS system. Designed to join two glass threads together, the coupling allows a certain degree of misalignment. The couplings are suitable for long-term use up to 180 “C and temperatures up to 200 “C are permis- sible for short periods.Four sizes are available: GL 14, 18, 25 and 32. Schott Glass Ltd., Drummond Road, Astonfields Industrial Estate, Stafford ST16 3EL. Literature A catalogue describes the Yellow Springs Instruments range of conductivity instrumentation and calibration acces- sories. Five meters are described, from the push-button Model 34 to the well established S-C-T Meter Model 33. Six standard conductivity cells, a platinising instrument, calibrator solutions and a set of seven close tolerance calibration resis- tors are also described. Clandon Scientific Ltd., Lysons Ave- nue, Ash Vale, Aldershot, Hampshire. “How to Get Started in Gas Chromato- graphy,” a 12-page guide, shows what is needed to install a packed or capillary column gas chromatograph, what is needed to maintain operation and how to plumb carrier and combustion gas lines and regulate gas flow. Other literature discussing operation and maintenance in more depth is also provided. Supelchem (R. B. Radley and Co. Ltd. ,), London Road, Sawbridgeworth, Hertfordshire CM21 9JH. A brochure gives details of the llOOA oxygen analyser, which has recently been granted BASEEFA approval (ExN I1 T5). Servomex Ltd., Crowborough, Sussex TN6 3DU.ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 153 groups and additives which may be used ties. Anyone wishing to see the MAFF culture, Fisheries and Food, Great in feeding stuffs before January 3, 1985. circulation or the Directive itself should Westminster House, Horseferry Road, They therefore circulated the relevant contact Mrs. E. Owen, Ministry of Agri- London SWlP 2AE. parts of the Directive to interested par-

ISSN:0144-557X    

DOI:10.1039/AP9852200150

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 153 Conferences and Meetings Evaluation of Occupational Gas and Dust Hazards June 20-21, 1984, London This seminar, which is to be organised by Sira, will be held at the Zoological Society of London, London, N.W.l. For details of the seminar contact the Conference Unit, Sira Ltd., South Hill, Chislehurst, Kent BR7 5EH. Gordon Research Conference August 12-16, 1985, New Hampton, NH, USA The analytical conference of the Gordon Research Conferences will be held at New Hampton School. The subject on August 12 will be The Hyphenated Methods and Microprobe and Imaging Analysis; August 13, Advances in Analytical Nuclear Magnetic Resonance and Mathematical Separation of Mixtures; August 14, Optimisation of Analytical Methods and Data Bases and Analytical Chemistry; August 15, Sensors in Analy- tical Chemistry and Process Analytical Chemistry; and August 16, Remote and In-situ Analysis.For further information contact Dr. Alexander M. Cruickshank, Gordon Research Conferences, Gordon Research Center, University of Rhode Island, Kingston, Rhode Island, USA. 14th X-ray Spectrometry Conference September 9-13, 1985, Durham A five-day conference on X-ray spec- trometry is being organised by Philips Analytical. To be held at Durham Univer- sity, the event aims to provide a forum for the interchange of ideas and experiences in X-ray spectrometry and associated topics. The subjects to be covered include advances in instrumentation for X-ray spectrometry and applications of the tech- nique, methods for sample preparation and presentation, qualitative and semi- quantitative analysis, data handling tech- niques and X-ray fluorescence as a stan- dard method.There will be a workshop and syndicate session on comparative techniques, and for the first time there will be a poster session giving all delegates the opportunity to-present a paper. The conference, the 14th in the series and the fifth at Durham, is being organ- ised by Philips Analytical in conjunction with the University’s Department of Geological Sciences. Accommodation will be at University College and many of the non-technical activities will take place at Durham Castle, which is part of the college. Potential contributors to the event should notify the Conference Secre- tary of their subject and include a 50-100 word synopsis.Further details -are available from Ms. Margaret Courtney, Conference Secre- tary, Philips Analytical Department, Pye Unicam Ltd., York Street, Cambridge CB12PX. Particle Size Analysis Conference (PSA 85) September 16-19, 1984, Bradford The Fifth Particle Size Analysis Confer- ence to be held under the auspices of the Analytical Division of the Royal Society of Chemistry will be held at the University of Bradford. The Conference will be concerned with measurement of the par- ticle size distribution of powders, suspen- sions and aerosols, the determination of surface area, particle shape and pore size distribution, and will cover ancillary tech- niques such as sampling, dispersion and particle density measurement together with the application of particle character- isation techniques to industrial problems.The plenary lectures will be Dr. N. G. Stanley-Wood, Dr. T. Allen, Professor E. Heidenreich, Dr. M. Martin and Pro- fessor B. Scarlett. For further information and registra- tion forms please contact Dr. N. G. Stanley-Wood, School of Powder Tech- nology, University of Bradford, Brad- ford, West Yorkshire BD7 1DP. FACSS ’85 September 29-October 4, 1985, Philadel- phia, PA, USA The Federation of Analytical Chemistry and Spectroscopy Societies will hold its twelfth FACSS meeting in Philadelphia. The Program Committee is pleased to announce that it is now accepting titles for the meeting. Poster sessions and oral presentations are planned in all areas of analytical chemistry and spectroscopy including: Atomic Spectroscopy [AAS (flame and furnace), fluorescence, ICP and DCP]; Vibrational Spectroscopy (infrared/NIR, Raman) ; Chromato- graphy (liquid, SEC, gas, thin-layer, ion exchange); NMR Spectroscopy; Mass Spectrometry; Process Analytical; Clinical - Pharmacology; Computer Aided Chemistry; Chemometrics; New Analytical Techniques; Environmental Analysis; Thermal Analysis; Surface Analysis; Electrochemistry; Forensic Chemistry; X-ray Analysis; Particle Size Analysis; UV - Visible Spectroscopy; Fluorescence Spectroscopy; Flow Injec- tion Analysis; Microscopy; Robotics; General.For further information write to the FACSS XI1 Program Chairman, Dr. Matthew S. Klee, Smith Kline and French Laboratories, 709 Swedeland Road, L25, Swedeland, PA 19479, USA. Monitoring in Industry November 12-13, 1985, Antwerp, Bel- gium An international symposium on the above subject is to be organised by the Safety Commission of the Technological Insti- tute of the Royal Society of Flemish Engineers.Among the papers presented will be: “Occupational Exposure Limits ,” by R. L. Zielhuis; “Occupational Ex- posure Limit Values,” by R. Grosjean; “Monitoring-General Aspects,” by J. T. Sanderson; “Monitoring Strategy,” by E. Drope; “Biological Monitoring,” by R. Lauwerys; “Personal Monitoring Tech- niques,” by R. K. Schmidt; “Special Techniques,” by K. Hellwig; “Specific Monitoring Techniques for Dust,” by J. P. de Worm; “Monitoring of Noise and Vibrations,” by C. Bot; “Monitoring of Dusts,” by B. Preat; “Monitoring in Chemical Industry,” by H. M.Widmer. For further information contact Ms. R. Peys, Technologisch Instituut-K.VIV, Jan van Rijswijcklaan 58, 2018- Antwerpen, Belgium. The Eastern Analytical Symposium November 19-22, 1985, New York, USA The 1985 EAS will again be held at the New York Penta Hotel. As was the case in 1984, technical sessions will be held on all four days of the meeting, with the exposi- tion again running for 34 days. Based upon the success of the 1983 and 1984 poster sessions, it is planned to expand these at the 1985 EAS and to create a special award for Best Poster. With the Pittsburgh Conference having been in154 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 New Orleans in February, the EAS will be the largest meeting dedicated to the Analytical Sciences on the East Coast to be held in 1985. As such, it is anticipated that even this past year’s record attend- ance will once again be surpassed. For further details contact Dr. S. David Klein, EAS Publicity, Merck and Co. Inc., P.O. Box 2000/R80L-106, Rahway, NJ 07065, USA. I11 World Congress of the World Feder- ation of Associations of Clinical Toxicol- ogy and Poison Control Centres and XI1 International Congress of the European Association of Poison Control Centres (EAPCC) August 27-30, 1986, Brussels, Belgium This joint congress will be held at the Brussels Congress Centre. The main top- ics of the congress will be: Toxicokinetics and Pharmacokinetics in Clinical Toxicol- ogy; New Investigation Techniques; Immunotoxicology - Immunotherapy; Paediatric Toxicology; New Solvents; Medical Aspects of Environmental Pollu- tion; Standardisation and Criteria for Data of Poison Control Centres; Ethics, Deontology and Responsibility of Poison Control Centres. Further information can be obtained from the administrative secretariat, SDR Associated, Rue Vialin XIIII, 17a, B-1050, Brussels, Belgium.

ISSN:0144-557X    

DOI:10.1039/AP9852200153

出版商:RSC    

年代:1985

数据来源: RSC

摘要:

154 ANALYTICAL PROCEEDINGS, MAY 1985, VOL 22 Courses Statistical Workshops for Scientists, Tech- nologists and Engineers 1985 Statistics for Industry will be holding courses at various locations throughout 1985. The venues will be the Bloomsbury Crest Hotel, London, W.C.l., The Cairn Hotel, Harrogate, The Queen’s Hotel, Eastbourne, The University of Surrey, Guildford, The University of Warwick, Coventry, and the University of York. The courses include “Introduction and Significance Testing,” “Statistics in Research and Development ,” “Statistics in Quality Assurance,” “Statistics for Analytical Chemists” and “Design for Experiments. ” Details are available from Angela Boddy, Statistics for Industry (UK) Ltd., 14 Kirkgate, Knaresborough, North Yorkshire, HG5 8AD. Sira Courses 1985 The Conference Unit of Sira will be organising the following courses in 1985.May 21-22 and November 26-27, “Optical Engineering 11,” Chislehurst ; June 11-13 and November 5-7, “Safety of Electrical Equipment in Potentially Explosive Atmospheres,” Bromley ; June 26 and November 20, “Classification of Hazardous Areas Containing Potentially Explosive Atmospheres,’’ London; July 3-4 and October 23-24, “Introduction to Military Thermal Imaging,” Chislehurst; September 10-11, “Optical Engineering I,” Chislehurst; September 17-19, “Fibre Optics for Instrumentation: Basics, Sen- sors and Systems,” Manchester; Septem- ber 23-24, “Microprocessor Familiarisa- tion,” Bromley; September 27, “Indus- trial Applications of Expert Systems,” London; October 14-16, “Testing Com- plete Thermal Imaging Systems and Asso- ciated Optical Materials and Com- ponen ts ,” Chislehurst .For further information contact the Conference Unit, Sira Ltd., South Hill, Chislehurst, Kent BR7 5EH. Infrared Summer School at Cambridge July 29-August 2,1985, Cambridge A five-day residential school at Cam- bridge, aimed at providing participants with a comprehensive understanding of the theory and the application of infrared spectrophotometry , has been organised by Pye Unicam. The course is to take place from July 29 to August 2, with accommodation at Queen’s College, and has been designed to provide chemists with instruction in modern instrumental techniques, including data processing, spectral interpretation and the latest sam- ple handling methods. Practical work will be carried out at Pye Unicam. A sound organic chemistry background is required, together with an understand- ing of infrared spectroscopy, for partici- pants to gain maximum benefit. Experts will be on hand to advise on specific sampling, interpretation and application problems. Guest speakers will include Dr. A. J. Baker of the University of Glasgow, Dr. D. B. Powell of the University of East Anglia, Dr. C. J. Timmons of the Univer- sity of Nottingham and Mr. P. Carter of FBC Ltd. A fee of f425 plus VAT includes five nights’ accommodation, meals, tuition and course material. For further informa- tion please contact Mrs. R. Fullerton at Pye Unicam.

ISSN:0144-557X    

DOI:10.1039/AP985220154b

出版商:RSC    

年代:1985

数据来源: RSC