ISSN:0144-557X    

DOI:10.1039/AP99128FX005

出版商:RSC    

年代:1991

数据来源: RSC

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ANPRDI 28(2) 33-56 (1991) Proceedings of the Analytical Division of The Royal Society of Chemistry 33 Reports of Meetings 34 Analytical Viewpoint 34 'Analytical Chemistry of Complex Matrices' by W. Franklin Smyth 37 SUMMARIES OF PAPERS 37 Research and Development Topics in Analytical Chemistry 37 38 40 41 43 44 'Development of an Automated High-performance Liquid Chromatography System for the Determination of Trace Metals in Concentrated Brines' by Howard W. Handley, Philip Jones, Les Ebdon and Neil W. Barnett 'Applications of Chemiluminescence to Clinical, Forensic and Pharmaceutical Analysis' by A. R. J. Andrews 'Magnesium as a Modifier for the Determination of Barium by Flame Atomic Emission Spectrometry' by Mohammad Jerrow, lain L. Marr and Malcolm S. Cresser 'High-performance Liquid Chromatographic Determination of Some Trace Metal Ions Using a Novel Column Switching Technique' by Eva Ryan and Mary Meaney 'Separation of Urinary Organic Acids by High-performance Liquid Chromatography' by R. G. Anderson and N. V. Fox 'Investigation of In Situ Concentration of Hydride Forming Elements in a Graphite Furnace Atomiser' by Muhammad Mansha Chaudhry, Allan M. Ure, Brian G. Cooksey, David Littlejohn and David J. Halls 47 Equipment News 49 Analytical Division Distinguished Service Award (Rules) 49 SAC Silver Medal (Rules) 50 Chair for Analytical Chemist 51 Conferences and Meetings 52 Courses 54 Analytical Division Diary Typeset and printed by Black Bear Press Limited, Cambridge, England Analytical Proceedings CONTENTS February 1991

ISSN:0144-557X    

DOI:10.1039/AP99128BX007

出版商:RSC    

年代:1991

数据来源: RSC

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ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 33 Reports of Meetin,gs Scottish Region The fifty-sixth Annual General Meeting of the Region was held at 7 p.m. on Friday, November 2nd, 1990, at the Uni- versity of Strathclyde, Glasgow. The Chair was taken by the Chairman of the Region, Mr. A. D. Ruthven. The follow- ing office bearers were elected for the forthcoming year: Chairman-Mr. A. D. Ruthven. Vice-Chairman-Professor D. Littlejohn. Honorary Secretary-Mr. E. C. Smith, ICI Fine Chemicals Manu- facturing Organisation, Earls Road, Grangemouth FK3 8XG. Honorary Treasurer-Dr. J. M. Warren. Honorary Assistant Secretary-Mr. M. F. Godfray. Members of Committee-Mr. R. I. Aylott, Mr. M. J. Durey, Dr. H. H. J. Girault, Dr. A. Hursthouse, Dr. A. R. Morrison and Mr. P. J. Stevens (ex officio).Dr. J. E. Whitley was re-appoin- ted as Honorary Auditor. Molecular Spectroscopy Group The fourth Annual General Meeting of the Group was held at 1.40 p.m. on Wednesday, November 7th, 1990, at the Zoological Society Lecture Rooms, Regents Park, London. The Chair was taken by the Chairman of the Group, Mr. A. M. C. Davies. The following office bearers were elected for the forthcoming year: Chairman-Dr. R. A. Spragg. Vice- Chairman-Professor P. J . Worsfold. Honorary Secretary-Dr. D. L. Andrews, School of Chemical Sciences, University of East Anglia, Norwich NR4 7JT. Honorary Treasurer-Mr. J . M. Chalmers. Members of Committee-Dr. I . Cancheteux, Dr. A. M. Chippendale, Dr. F. H. Cottee, Mr. A. M. C. Davies (ex officio), Mr. J. Gilbert and Mr. F. W.Sweeting. Dr. J. D. Green and Dr. J. Marshall were appointed as Honorary Auditors. Radiochemical Methods Group The twenty-fourth Annual General Meet- ing of the Group was held at 2 p.m. on Wednesday, November 14th, 1990, at the Winfrith Technology Centre, Dorchester, Dorset. The Chair was taken by the Chairman of the Group, Mr. A. Lally. The following office bearers were elected for the forthcoming year: Chairman-Dr. J. Troke. Vice-Chairman-Mr. A. Lally. Honorary Secretary-Dr. P. Warwick, Department of Chemistry, University of Technology, Loughborough, Leicester- shire LE11 3TU. Honorary Treasurer- Dr. A. J. Palmer. Members of Committee -Dr. R. C. Carpenter, Mr. M. A. Crook, Dr. A. Gethin, Dr. R. Grieve, Dr. K. Leonard, Dr. P. Robb and Dr. A. R. Ware (co-opted).Mr. G. Farmer and Dr. D. J. Spring were re-appointed as Honorary Auditors. Chromatography and Electrophoresis Group The twenty-sixth Annual General Meet- ing of the Group was held at 2.15 p.m. on Tuesday, November 20th, 1990, at Glaxo Group Research, Greenford. The Chair was taken by the Chairman of the Group, Dr. F. K. Butcher. The following office bearers were elected for the forthcoming year: Chairman-Dr. F. K. Butcher. Vice-Chairman-Dr. S. Laing. Honorary Secretary and Treasurer-Dr . D. Simp- son, Analysis For Industry, Factories 2/3, Bosworth House, High Street, Thorpe-le- Soken, Essex C016 OAA. Members of Committee-Dr. R. J. Flanagan, Dr. P. J. Houghton (ex officio), Mr. N. G. McTaggart (co-opted), Dr. D. Perrett, Dr. H. Read and Dr. R. M. Smith. Mr. L. R.F. J. Fernandes was re-appoin- ted as Honorary Auditor. The financial statement for the year ending July 1990 showed that income exceeded expenditure by 22949, thus increasing the balance in the current account to f3107; the deposit account balance stood at f4457. Biological Methods Group The forty-sixth Annual General Meeting of the Group was held at 6 p.m. on Thursday, November 22nd, 1990, at The Royal Society of Chemistry, Burlington House, London W1. The Chair was taken by the Secretary of the Group, Mr. A. J. Crooks. The following office bearers were elected for the forthcoming year: Chair- man-Dr. Rosemary Pask-Hughes. Vice- Chairman-Dr. M. Easton. Honorary Secretary-Mr. A. J. Crooks, Biologics Division, PHLS Centre for Applied Microbiology and Research, Porton Down, Salisbury, Wiltshire SP1 3PH.Honorary Treasurer-Dr. A. H. Thomas. Members of Committee-Dr. J. A. Car- ney, Mr. D. Hossack, Dr. J. Little, Dr. P. Patel, Mr. G. A. Sabey (ex officio), Dr. L. Singleton and Dr. S. Tendler. Dr. J. H. Hamence and Mr. J. A. Holgate were re-appointed as Honorary Auditors. The financial statement for the year ending July, 1990, showed that expendi- ture exceeded income by f2396, thus reducing the balance in the current account to E310, after transfer of 51438 from the deposit account; the deposit account balance stood at &83. Atomic Spectroscopy Group The twenty-sixth Annual General Meet- ing of the Group was held at 1.45 p.m. on Wednesday, November 21st, 1990, at the National Physical Laboratory, Tedding- ton. The Chair was taken by the Chair- man of the Group, Professor M.s. Cresser. The following office bearers were elected for the forthcoming year: Chairman-Dr. J . Marshall. Vice-Chair- man-Dr. B. Sharp. Honorary Secretary -Dr. J. R. Dean, Department of Chem- ical and Life Sciences, Newcastle upon Tyne Polytechnic, Ellison Building, New- castle upon Tyne NE1 8ST. Honorary Treasurer-Dr. D. A. Hickman. Honor- ary Assistant Secretary-Mr. C. A. Wat- son. Members of Committee-Dr. M. Cave, Professor M. S. Cresser (ex offi- cio), Dr. J. Crighton, Ms. J. Egan (co- opted), Dr. S. J. Hill (co-opted), Profes- sor D. Littlejohn and Dr. M. Thomsen. Mr. P. Sadler and Mr. T. Catterick were re-appointed as Honorary Auditors. Micro & Chemical Methods Group The forty-seventh Annual General Meet- ing of the Group was held at 6 p.m. on Wednesday, November 28th, 1990, at the London School of Economics.The Chair was taken by the Chairman of the Group, Mr. M. J. Graham. The following office bearers were elected for the forthcoming year: Chairman-Dr. M. A. Russell. Vice- Chairman-Mr. M. J. Graham. Honorary Secretary-Miss L. Dixon, CMB Packaging Technology PLC, Denchworth Road, Wantage, Oxford- shire OX12 9BP. Honorary Treasurer: Mr. M. R. Cottrell. Honorary Assistant Secretary-Mr. P. R. W. Baker. Members of Committee-Mrs. D. Butterworth (co- opted), Mr. A. Fassam, Dr. E. D. Mor- gan, Dr. D. Kealey, Mr. G. M. Powell, Mr. B. T. Saunderson, Mr. D. J. Thom- son and Mr. C. A. Watson (co-opted). Mr. H. I. Shalgosky and Professor D. W. Wilson were re-appointed as Honorary Auditors. The financial statement for the year ending July, 1990, showed that expendi- ture exceeded income by &419, thus reducing the balance in the current account to f605; the deposit account balance stood at f2326. A presentation by the President of the Division, Professor J. D. R. Thomas, was made to Mr. Baker, who was retiring after 20 years as Honorary Secretary of the Group.

ISSN:0144-557X    

DOI:10.1039/AP9912800033

出版商:RSC    

年代:1991

数据来源: RSC

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34 ANALYTICAL PROCEEDINGS, FEBRUARY 1991. VOL 28 Ana lyt ica I View point The following is a member of a continuing series of articles providing either a personal view of part of one discipline in analytical chemistry (its present state, where it may be leading, etc.), or a philosophical look at a topic of relevance to chemists in general or analytical chemists in particular. These contributions need not have been the subject of papers at Analytical Division Meetings. Persons wishing to provide an article for publication in this series are invited to contact the editor of Analytical Proceedings, who will be pleased to receive manuscripts or to discuss outline ideas with prospective authors. Analytical Chemistry of Complex Matrices W. Franklin Smyth* Chemistry Department, University of Zambia, P.O.Box 32379, Lusaka, Zambia The analytical chemistry of complex matrices introduces students to ‘real world’ problem solving once they have become familiar with the theory and practice of the wide range of analytical methods and techniques that are currently available. ‘Real world’ problem solving is concerned with the identifica- tion and determination of a wide range of chemical species in samples of the atmosphere, factory air, natural waters, industrial effluents, drinking water, plants, soils, minerals, foods, industrial products, biological materials, etc. While text-books are readily available on the theory and practice of analytical methods and techniques, as outlined by Locke and Grossman,’ there is a distinct lack of educational literature dedicated to the evaluation and solution of such analytical problems. It is to that end that this article has been written and it is based on the author’s experience in teaching analytical chemistry to final year undergraduate and postgraduate students in universities in the United Kingdom, Denmark, Ireland, Finland, Israel and Zambia.Unit Processes All analytical problems, from the moment they become apparent to their final solution, can be subdivided according to eight unit processes. These are: 1, definition of the problem; 2, choice of the method; 3, obtaining a representative sample and its measurement; 4, preliminary treatment of sample; 5 , separation of analytes from interferences and from each other; 6, measurement; 7, statistical assessment of measurements; and 8, solution of the problem.A course on the analytical chemistry of complex matrices should ideally start with in-depth treatment of each of these unit processes. The first unit process, i.e., definition of the problem, is invariably the identification and/or determination of one or several chemical species in a particular matrix. It is useful at this stage to refer to the sample mass classification and constituent content classification given in the IUPAC article by Sandell and West.2 Some topical analytical problems that the author has referred to in his teaching programmes are given in Table 1. * Present address: Department of Applied Physical Sciences. University of Ulster, Coleraine, Co. Londonderry BT52 ISA, North- ern Ireland. Table 1 Analyte(s) to be identified and/or determined Some topical analytical problems Matrix 1 Nitrogen oxides 2 Isocyanates 3 Organoarsenic compounds 4 Heavy metal ions 5 Fluoride 6 Phenols 7 Boron 8 Cobalt 9 Iron 10 Lactose 11 Nickel 12 Procaine penicillin 13 VitaminC 14 Flurazepam and metabolites Atmosphere Factory air River water Sea-water Drinking water Industrial effluent Plant Soil Mineral Milk Steel Pharmaceutical raw material Pharmaceutical formulation Blood Note that in Table 1, a selection of inorganic, organic and organometallic analytes are chosen to be identified and/or determined in a variety of complex matrices.As will be illustrated later in the text, these analytes can be measured by application of a range of chemical and instrumental techniques of analysis.The choice of the method is obviously dependent on the availability of analytical methodology and instrumentation in the laboratory that has to solve the problem. The necessity for a literature search should be emphasized so that the analytical scientist can acquaint himself with alternative analytical methods of which he is not aware or may have forgotten. Given the resources of a well equipped instrumental laboratory, there are, in reality, alternative ways of solving a particular problem, e . g . , fluoride is ideally measured by the fluoride ion-selective electrode but can also be determined with at least comparable selectivity by ion chromatography and also by argentimetric precipitation titration and by fluoride quenching of the fluorescence of the aluminium complex of Alizarin Garnet R.Although this latter method would not have the selectivity of the first two, its limit of detection, if required in the solution of the analytical problem, is considerably lower, at 1 ppb. It is instructive to use such method comparison for the other analytical problems outlined in Table 1. Once the analytical scientist has decided on the chosen method, it should be tested to see if it conforms to the necessary accuracy, precision,ANALYTICAL PROCEEDINGS, FEBRUARY 1991. VOL 28 35 concentration range, limit of detection, selectivity, time per sample, cost per sample, etc. It should be noted that the literature contains different definitions for analytical para- meters, such as the limit of detection, so that when these parameters are quoted with reference to the solution of a particular analytical problem, mention should be made as to their exact definition in each instance.Useful additional reading material on the limit of detection can be found in references 3 and 4. The unit process of obtaining a representative sample and its measurement can be conveniently discussed in terms of sampling gaseous, liquid and solid materials. Gaseous materials are composed of gases and aerosol/particulate material and these are sampled in different ways, e.g., gases in air are sampled by drawing a known volume of air through an absorbing solution prior to measurement or by adsorption on activated carbon or a porous polymer prior to desorption and measurement. Publications emanating from the Health and Safety Executive, UK, on the determination of organic contaminant concentrations in workplace atmospheres provide useful material for teaching purposes, e.g., reference 5 .Liquid materials, such as those from the aqueous environment, are representatively sampled in rigorously cleaned collecting vessels, noting temperature, time, place, flow rate, etc. The pitfalls that can occur in these sampling operations should be pointed out, e.g., the occurrence of zinc in certain plastic collecting vessels can lead to an inaccurate determination of this same element in water samples. Solid materials such as bulk iron ore can be sampled by selection and withdrawal of valid gross samples of the population and then reduction of the gross sample(s) to a laboratory sample suitable for the application of the analytical method or technique.Reference to this and other sampling strategies is to be found in the article by Kratochvil and Taylor.6 Preliminary treatment of sample refers to procedures after sampling and prior to the unit processes of separation and determination. For example, immediate derivatization of a labile molecule, such as an isocyanate, in a sample taken from a workplace atmosphere,s storage, preservation and transport of water samples obtained in the field, treatment of a blood sample to yield plasma and serum and their storage prior to measurement, acid digestion of inorganic solids prior to, say, atomic absorption spectrometric determination, and dry and wet ashing of organic and biological materials to destroy organic matter prior to trace metal analysis.Under the heading of separation of analytes from interfer- ences and from each other, traditional separation methods such as masking, precipitation and solvent extraction are worthy of discussion. For example, precipitation can be used in trace analysis by co-precipitation of trace metals with the precipitation of a major metallic constituent in the sample, as illustrated by 8-hydroxyquinoline, tannic acid and thioanilide giving complete recovery of Co, Ni, Mo, Sn, Pb, Zn, Cr, V, Ti, Be and Ge in a matrix of Al2O3 with spectrographic and chemical errors of <lo% for 2-100 vg amounts of these elements in plants and soils.7 Solvent extraction has an important role in separating organic analytes from interfering biological material in blood samples, for example, prior to application of a chromatographic technique, and trace metals can be separated and concentrated from water samples by solvent extraction of neutrally charged metal chelates into isobutyl methyl ketone solvent prior to atomic absorption spectrometric determination.Chromatographic separation of organic and organometallic analytes by such techniques as thin-layer, gas-liquid and high-performance liquid chromato- graphy merits lengthy discussion in the unit process of separation. Topical applications of these techniques to organic analysis can be found in most modern text-books in analytical chemistry. Some texts are devoted exclusively to applications, in which chromatographic techniques figure predominantly as methods of choice, e.g., in the analysis of organic micropollutants such as phenols in water.8 The unit process of measurement involves application of the numerous chemical and instrumental techniques of analysis no doubt covered in an early course in analytical chemistry.These techniques should be classified according to whether they be chemical, spectroscopic, electrochemical, thermal, biological or miscellaneous. Statistical assessment of measurements involves removal of insignificant data (Q-test), calculation of the mean (X), standard deviation (S) and relative standard deviation (S/X X loo), application of t-factor to calculate confidence intervals, comparison of precisions of two replicate sets of data by the F-test and comparison of means of two replicate sets of data by the t-test.The final unit process of calculation of result, and hence solution of the problem involves, for quantitative analysis, conversion of the mean measurement to concentra- tion of the analyte by the use of a calibration graph, internal standard or standard additions method. Analytical parameters used in identification are many and varied, e.g., retention time, half-wave potential, wavelength of absorption, etc. Some Topical Analytical Problems A course on the analytical chemistry of complex matrices could therefore consider each of the problems presented in Table 1 and detail its solution by reference to the constituent unit processes of choice of method, sampling, pre-treatment of sample and so on. In order to assist someone who might teach such a course to final year and postgraduate students of analytical chemistry, Table 2 lists the analytical techniques recommended for discussion in the solution of these problems, together with viable alternative techniques.Further reference may be made to the literature, where indicated. Such a lecture course should be complemented by relevant course work in the form of practicals, where possible, and worked examples. Practical experiments on problems such as numbers 7,8,9,10,11 and 13 should be possible in laboratories lacking modern instrumentation providing certain standards and reagents are available. Worked examples based on these ‘real world’ analytical problems can be designed by the lecturer and such an example is given below for problem no.8, i.e., the colorimetric determination of cobalt in soil after chelation with the 1- nitroso-2-naphthol reagent. ’Soils derived from granitic sources are often low in cobalt and this can affect the health of grazing animals, e.g., pining in sheep. Hence, the determination of cobalt at ppm concentrations in soil samples is of significant agricultural importance. Consider the following spectrophotometric method for cobalt determination and answer the ques- tions at the end. Five grams of a soil sample were heated for 16 h at 500°C in a platinum crucible. The residue was taken up in 100 ml of concentrated HCI. A 20 ml aliquot of this solution was solvent extracted with 40 ml of diethyl ether in a 100 ml separating funnel. The aqueous layer was then sepa- rated from the diethyl ether layer and the former evapor- ated to almost dryness on a water-bath.Concentrated HCI (0.5 ml) plus 6 drops of concentrated HN03 were then added and this was made up to 15 ml with distilled water, followed by boiling for 2 min. After cooling, 2 ml of a 0.1 % solution of l-nitroso-2-naphthol plus 2 g of CH3COONa were added and the solution was heated to 70°C. Next, 5 drops of phenolphthalein were added and then 10% KOH until the colour changed to pink. A further 3 drops of phenolphthalein were added and sufficient 0.5 mol dm-3 HCI to destroy the pink colour. The solution was then boiled for 2 min, cooled and diluted to 50 ml. The absorbance of this solution was then measured by using a cell with a path length of 4 cm. Its concentration was36 ANALYTICAL PROCEEDINGS, FEBRUARY 1991.VOL 28 Table 2 Analytical techniques used in the solution of topical analytical problems Analyte Matrix 1 Nitrogen Atmosphere oxides 2 Isocyanates Factory air 3 Organoarsenic River water compounds 4 Heavy metal ions Sea-water 5 Fluoride Drinking water 6 Phenols Industrial 7 Boron Plants effluents 8 Cobalt Soil 9 Iron Mineral 10 Lactose Milk 11 Nickel Steel 12 Procaine Pharmaceutical penicillin G raw material 13 VitaminC Pharmaceutical formulation 14 Flurazepam Blood and metabolites Technique Chemiluminescence of NO2*, product of reaction of NO and O3 High-performance liquid chromatography with UV or electrochemical detection5 Determination of inorganic and organic anions of arsenic by ion chromatography- hydride generation-atomic absorption spectrometry9 Anodic stripping voltammetryl Ion-selective electrode measurement" Gas chromatography with flame ionization or electron capture detection13 Colorimetry after use of boron-azomethine H reagent14 Colorimetry after use of 1-nitroso-2-naphthol reagent15 Titrimetric determination of FeIl with KMn04 or K2Cr20716 Reduction of CuI1 to Cul which reduces phosphomolybdic acid to a blue complex with A,,, = 630 nm Gravimetric determination with dimethylglyoximel8 Identification by infrared spectroscopy19 Titration with I2 or KBr03*0 Solvent extraction and differential-pulse polarograph y22 Alternative technique Colorimetry at 550 nm of the product of the reaction of NO? with sulphanilic acid followed by reaction of the resulting diazo derivative with N-( 1-naphthy1)ethylenediamine in aqueous CH3COOH Gas-liquid chromatography Determination of total As by atomic absorption spectrometry10 after NaBH4 reduction to AsH3 Atomic absorption spectrometry" Ion chromatography; fluoride quenching of the fluorescence of the A1 complex of Alizarin Garnet R Colorimetry; 13 high-performance liquid chromatography13 Colorimetry after use of 1,l'-imino- dianthraquinone reagent14 Cathodic stripping voltammetry of cobalt- dimethylglyoxime chelate11 Atomic absorption spectrometry Derivatization + gas-liquid chromatography with flame ionization detection" Polarography ; atomic absorption spectrometry Functional group analysis of the primary aromatic amine group19 High-performance liquid chromatography21 High-performance liquid chromatography23 determined by comparison with standards prepared as follows.A 0.434 g amount of CoCI2-6H20 was dissolved in 1 I of distilled water and 100 ml of this solution were diluted to 1 I with distilled water: 0.5, 1,2 and 3 ml of this solution were then taken and each treated as above from "Concentrated HCI (0.5 ml) + 6 drops of concentrated HN03 were then added and this . . .". The measured absorbances of these standard solutions were found to be 0.15, 0.23, 0.40 and 0.56 and the absorbance of the unknown 0.20. Answer the following questions. (a) Why was the soil sample heated at 500°C? ( b ) Why was the solvent extraction with diethyl ether performed? (c) What structure of chelate would you expect to be formed with cobalt and would you expect any other trace metal ions to interfere in the over-all analytical method? ( d ) Why use a cell of path length 4 cm? (e) What is the concentration of cobalt in the original sample in mg kg-1 (relative atomic mass of cobalt is 58.94, relative molecular mass of CoCI2.6H20 237.93)? ( f ) Design an analytical method based on atomic absorp- tion spectrophotometry at 240.7 nm for the determina- tion of cobalt in the same soil sample.How does the proposed AA method compare with the spectropho- tometric method using 1-nitroso-2-naphthol in terms of limit of detection, selectivity of determination, time per sample and cost per sample?' References 1 2 3 Locke, D. C . , and Grossman, W. E . L., Anal. Chem., 1987,59, 829A. Sandell, E. B . , and West, T. S., Pure Appl. Chem., 1979, 51, 43.ACS Committee on Environmental Improvement and Subcom- 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 mittee on Environmental Analytical Chemistry, Anal. Chem., 1980.52, 2242. Analytical Methods Committee, Analyst, 1987, 112, 199. Purnell, C. J.. Bagon, D. A., and Warwick, C. J.. in Analytical Techniques in Environmental Chemistry 2 , cd. Albaiges, J., Pergamon, Oxford, 1982, p. 203. Kratochvil, B., and Taylor, J. K.. Anal. Chem., 1981.53,924A. Mitchell, R. L . , and Scott, R. O., Spectrochim. Acta. 1948, 3, 367. Analysis of Organic Micropollutants in Water, eds. Bjorscth, A . , and Angeletti. G.. Reidel, Dordrecht. 1982. Ricci, G. R., Shepard, L. S., Colovos, G., and Hester, N. E., Anal. Chem., 1981, 53, 610. Robbins, W. B., and Caruso, J. A., Anal. Chem., 1979, 51, 889A. Gustavsson. I . , Acta Univ. Upsaliens., 1983, 701. Evans, A . , Potentiometry and Ion Selective Electrodes, Wiley, Chichester. 1987, p. 210. Analysis of Organic Micropollutants in Water, eds. Bjorseth, A . , and Angeletti, G., Reidel, Dordrecht, 1982, p. 286. Byrne, E., Chemical Analysis of Agricultural Materials, An Foras Taluntais, Dublin, 1978, p. 78. Byrne, E., Chemical Analysis of Agricultural Materials, An Foras Taluntais. Dublin, 1978, p. 114. Skoog, D . A . , and West, D. M., Fundamentals of Analytical Chemistry, CBS College Publishing, HRW International Edi- tion, 4th edn., 1982, pp. 757, 763. Macrae. R., J . Food Technol., 1980, 15, 93. Skoog, D. A.. and West, D. M., Fundamentals of Analytical Chemistry, CBS College Publishing, HRW International Edi- tion, 4th edn., 1982, p. 736. British Pharmacopoeia, HM Stationery Office, London, 1980, p. 368. Skoog, D. A.. and West. D. M., Fundamentals of Analytical Chemisrry, CBS College Publishing, HRW International Edi- tion, 4th edn., 1982, p. 774. Amin. M.. and Reusch, J., Analyst, 1987, 112, 989. Smyth. W. F., and Groves, J . A., Anal. Chim. Acta, 1981,123, 175. Dadgar, D., Smyth, W. F., and Hojabri, H., Anal. Chim. Acta, 1983, 147, 381.

ISSN:0144-557X    

DOI:10.1039/AP9912800034

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 37 Research and Development Topics in Analytical Chemistry The following are summaries of six of the papers presented at a Meeting of the Analytical Division held on July 16th-I7th, 1990, in ICI C and P Ltd., Runcorn, Cheshire. Summaries of seven other papers presented at the meeting appeared in the January issue (p. 8). Development of an Automated High-performance Liquid Chromatography System for the Determination of Trace Metals in Concentrated Brines Howard W. Handley, Philip Jones and Les Ebdon Plymouth Analytical Chemistry Research Unit, Department of Environmental Sciences, Polytechnic South West, Drake Circus, Plymouth PL4 8AA Neil W. Barnett ICI Chemicals and Polymers Ltd., Runcorn, Cheshire WA7 4QD Saturated brines are an important feedstock for several industrial processes, the chlor-alkali industry being one exam- ple.In recent years, new technology in the chlor-alkali industry has led to a shift away from mercury and diaphragm cells, towards membrane cells.' In order to achieve economic lifetimes of the membranes, trace metal levels in the feed brines need to be maintained at the low ng ml-1 level. In order to lower trace metal concentrations to acceptable levels the feed brines are passed through ion-exchange clean-up columns prior to being electrolysed in the cells. Acceptable levels for the alkaline earths, which are of particular interest, are less than 50 ng ml-1 for magnesium and calcium and less than 500 ng ml-1 for strontium and barium. For process control purposes it is necessary to monitor the efficiency of these clean-up columns.High-performance liquid chromatography (HPLC) lends itself well to on-line automation, as it is intrinsically safe, robust, has low maintenance costs and is relatively inexpen- sive, all of which are critical in the choice of a process monitor. Pre-concentration and Matrix Removal With the need to determine very low analyte concentrations in a highly concentrated matrix (30% m/v NaCl), work has centred mainly on pre-concentration-matrix elimination procedures. Chelating ion-exchange columns have been used extensively for sea-water analysis'.3 and for saturated brine analysis.l.5 Most of these reports are, however, concerned with off-line pre-concentration procedures followed by determina- tion by atomic spectrometry.When such a column is to be connected on-line with an HPLC system, various constraints are placed on the choice of the chelating exchanger used, for example: compatibility with solvents used in conventional ion chromatography; stability across a wide pH range; stability to high back-pressure; and, to some extent, particle size. With these constraints in mind, a pre-concentration-matrix elimina- tion column based on a dynamically coated chelating exchange resin was prepared. The chelating dye, Xylenol Orange (Sigma, Poole, Dorset, UK), was dynamically coated on to the anion-exchange resin, Dowex 1-X8 (BDH, Poole, Dorset, UK). The immobilization of the dye on the resin was achieved by stirring a slurry of the resin (3 g) in a 40% methanol solution (25 ml) with 100 mg of Xylenol Orange for 48 h at 50 "C.The immobilization is thought to proceed via a combination of several processes. Firstly, strong ionic interaction between the -SO3- group of the chelating dye and the tertiary ammonium group of the resin; secondly, non-polar-non-polar attraction between the benzene rings of the dye and the phenolic rings of the resin backbone; and finally, physical trapping of the dye within the pores of the resin beads. 2.6 x 1 0 - ~ A . u . I 40 30 20 10 0 Tim e/m in Fig. 1 Chromatogram showing three consecutive injections of 30% brine, followed by a calibration point, showing peaks for 1, magne- sium; 2, calcium; 3, strontium; and 4, barium. A.U. = arbitrary units Brine Analysis Using this pre-concentration column, 10 ml aliquots of saturated brine were pumped through the column at a flow rate of 2.5 ml min-1.The residual sodium chloride was washed from the column dead volume and connecting tubing with a 5 ml aliquot of dilute (2.5 x 10-3 mol dm-3) sodium hydroxide solution, prior to the retained trace metals being back-flushed on to the analytical column with a mobile phase of 0.2 mol dm-3 lactic acid-0.15 mol dm-3 ethylenediamine at pH 2.8. By using this mobile phase in conjunction with a strong cation-exchange column, the chromatography of the four alkaline earths was complete within 10 min. Detection was based on a system previously developed in these laboratories6 using inverse spectrophotometry. As the metals eluted from38 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 c L 5 I 0 s 2 1 1 I I I 1 I I 0 8 88 168 248 328 408 488 568 Time/rnin Fig.2 Variation of concentration of magnesium with time the analytical column they were mixed with a post-column reagent in a zero dead volume T-piece. Calmagite (2.5 x 10-4 mol dm-3)-MgEDTA (2.5 x mol dm-3) was used as a post-column reagent. The eluting metals displaced magnesium from the EDTA complex; this liberated magnesium which then complexed with the Calmagite, causing a decrease in absor- bance at the absorbance maximum of the dye which was monitared spectrophotometrically at 610 nm. The pH depen- dence of the uptake of the metals from the brine was studied. Optimum recoveries were found in the pH range 10-1 1. As the pH of the feed brines eluting from the clean-up columns was 10.8, no further sample pre-treatment was necessary.Linear calibrations were obtained for each of the metals studied in the concentration range of interest (0-200 ng ml-1). By using this methodology, the determination of the alkaline earths at the low ng ml-1 level in saturated brines was possible. 40 I I c I CD 5. - . p 30 0 C .- 4- 2 c. 20 C 0 u 8 88 168 248 328 408 488 568 Timefmin Fig. 3 Variation of concentration of calcium with time On-line Monitoring In order to test the suitability of the methodology and instrumentation as an on-line monitor of feed brines, the system was taken to a fully automated chlorine plant. Brine was continuously sampled from the outlet of the clean-up columns. By using this system, it was possible to analyse five brine samples per hour in addition to obtaining a calibration point.A section of the chromatogram obtained during the on-line trial is shown in Fig. 1. The system ran for a total of 36 h 100 r 1 m v) - 2 75 Y- c .g 50 h 4- 9, 25 0 0 I I I I I I I 8 88 168 248 328 408 488 568 Fig. 4 Time/min Variation of concentration of strontium with time before time restraints forced the termination of the trial. Data for a 10 h period are shown in Figs. 2-5. The calibration points are omitted for clarity. It can be seen that the levels of the four metals are all within the specified range. Conclusion The determination of the alkaline earths at the low ng ml-' level in saturated brines was achieved using chelating ion- exchange pre-concentration coupled to ion chromatography. The methodology was used successfully to monitor, on-line, feed brines used in the chlor-alkali industry.5. 1 30/ u" 101 I I I I I 8 88 168 248 328 408 488 Fig. 5 Ti m e/m i n Variation of concentration of barium with time The financial support of the SERC and ICI Chemicals and Polymers Ltd., under the CASE scheme for H. W. H., is gratefully acknowledged. References 1 2 3 4 5 6 Brooks, W. N., Chem. Br., 1986, 1095. Sturgeon, R. E., Berman, S. S., Willie, S. N., and Desculriers, J. A. H., Anal. Chem., 1981, 53, 2337. Sturgeon, R. E., Berman, S. S., and Willie, S. N., Tafunta, 1982, 29, 167. Kehr, P. F., Jones, J. S., Fritz, D. A., Harrington. D. E., and Bramstedt. W. R., At. Spectrosc., 1985, 6, 128. Wada. H., Asakura. K., Rattaiah, G. U., and Nakagawa, G.. Anal. Chim. Actu, 1988, 214, 439.Jones, P., Hobbs, P. J., and Ebdon, L.. Analyst, 1984,109,703. Applications of Chemiluminescence to Clinical, Forensic and Pharmaceutical Analysis A. R. J. Andrews School of Chemistry, The University, Hull HU6 7RX Chemiluminescence (CL) is the emission of light from an electronically excited species produced during the course of a chemical reaction.' This can be represented by the following equations: A+B-P* P" - P + hvANALYTICAL PROCEEDINGS. FEBRUARY 1991, VOL 28 39 where A and B are the starting reactants, P* is the electronic- ally excited species and P the same species in the ground state. The advent of modern microelectronics has meant that the analytical use of CL has grown appreciably over the last 10 years due both to its high selectivity and great sensitivity.2 This paper highlights some applications of CL in the fields of clinical, forensic and pharmaceutical analysis.Clinical A major application of CL in the clinical field has been for immunoassays. The use of CL reagents as replacements for radiolabels is an ever growing field as CL offers a similar limit of detection (LOD) to the use of radiolabels without any of the associated hazards. This subject has been well documented elsewhere and will not be covered here. A variety of other uses for CL in the clinical field have been developed. These vary from simple flow injection (FI) pro- cedures to specific liquid chromatographic (LC) analyses. The advent of FI has been one of the reasons for the increasing applications of CL. In the clinical field the uses range from simple screening methods3 to the determination of biological reductants.4-5 The suppression of CL has also been used to determine a- and L-amino acids.68 The novel CL reaction between catecholamines and acidic permanganate has also been proposed as a means of measurement.9 A more complicated FI system utilizing ion-pair extraction was devised for steroid sulphates.10 There has also been a series of papers on the determination of biological constituents (proteins) by various methods, the latest of which uses a zeolite column.'' Liquid chromatographic separation and CL detection is not as common as FI-CL owing to the general incompatibility of optimum CL conditions with optimum mobile phase require- ments for LC.However, it has been used to determine polyamines in plasma with both the luminol and peroxyoxalate reactions. 12.13 The peroxyoxalate reaction has also been used to determine both steroids and amino acids after derivatization and LC separation.14-17 The pre-column labelling of a-keto acids with 4,5-diaminophthalhydrazide has also been util- ized.18 Forensic Chemiluminescence would seem to be an ideal detection technique for forensic analyses. However, its selectivity is often a disadvantage and only a few applications have been proposed. One is the visualization of blood stainslg-20 and uses a simple luminol-hydrogen peroxide solution hand-sprayed over the area of interest. The subsequent emission can then be photographed and used as evidence. Patterns which would otherwise rely on a verbal description, or remain hidden, can thus be visualized and photographed.The other application is the determination of morphine in blood and urine samples after LC,21 based on the oxidation of morphine in an acidic mobile phase by permanganate, after polymer column separation. Pharmaceutical The determination of drugs is required not only in forensic and hospital laboratories or for pharmacokinetic information but also in the quality control laboratory. Drug tablets must conform to rigorous specifications and strict quality control is needed to ensure that these specifications are met. The use of FI-CL as a simple means of drug detection has been applied to a number of drugs including the benzodiaze- pine loprazolam , ? 2 3 morphine24 and a related opiate, bupre- norphine hydrochloride.25 Tetracycline, an antibiotic,26 and acetaminophen, an analgesic,2' have also been determined by CL.The detection of morphine and loprazolam used perman- ganate as an oxidant to generate CL, whereas tetracycline was detected by its CL reaction with bromine and acetaminophen by the reduction of cerium(1v). Conclusions The application of CL to the clinical, forensic and pharmaceut- ical fields has only just begun. Most of the papers referenced here have been published within the last 10 years, many within the last 5 years. Even in such a short time a diverse range of species can already be determined in matrices ranging from simple aqueous solutions to complex biological samples. Table 1 summarizes the analytes determined, limit of detection and Table 1 Some analytes, methods of CL generation and limits of detection (LOD) Analyte CL system Ascorbic acid Lucigenin-H202 Glucose Lucigenin-H202 Amino acid Luminol-H202 Amino acid Amino acid Amino acid Aspartic acid Steroid Steroid Protein Amines Amines Arnines Amines Keto acid Morphine Morphine Loprazolam Buprenorphine Tetracycline Acetaminophen Luminol-H202 Oxalate ester Oxalate ester Luminol-H202 Lucigenin-H202 Oxalate ester Phenanthroline-H2O2 Luminol-H202 Oxalate ester Permanganate Oxalate ester Luminol-H202 Permanganate Permanganate Permanganate Permanganate Bromine Cerium( IV) LOD Reference 0.17 mg 1-1 50 prnol 5 x 10-8 moll-' 4 pmol 2 fmol 0.2 fmol 2.7 ng 0.5 pmol 100pgmlkl pmol 0.8 fmol 7 pmol 5 pmol 4 fmol 50 ng 163 ng 0.5 pmol 1.6 nmol 70 ng mi-' 1 ng 0.7 Pg 4 5 5 8 16 17 7 10 14 11 12 15 9 13 18 24 21 23 25 26 27 the .method of CL generation. With the growing realization that CL offers a cheap, easy and reliable means of measure- ment, further research should yield many more CL reactions and hence methods of analysis for other species of interest.1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 References Luminescence Applications, ed. Goldberg, M. C., American Chemical Society, Washington, DC, 1989. Townshend, A., Analyst, 1990, 115, 495. Nakagama, T., Yarnada, M., and Suzuki, S., Anal. Chim. Ada, 1989, 217, 371. Veazey, R. L., and Nieman, T. A., Anal. Chem., 1979, 51, 2092. Maeda, M., and Tsuji, A.. Anal. Sci., 1986, 2, 183. Lowery, S. N., Carr, P. W., and Seitz, W. R., Anal. Lett., 1977, 10, 931.Hara, T., Toriyama, M., Ebuchi, T., and Imaki, M., Chem. Lett.. 1985, 3, 341. Macdonald, A., and Nieman, T. A., Anal. Chem., 1985, 57, 936. Ikkai, H., Nakagama, T., Yamada, M., and Hobo, T., Bull. Chem. SOC. Jpn, 1989,62, 1660. Maeda, M., and Tsuki, A., Analyst, 1985, 110, 665. Hara, T., Tsukagoshi, K., and Kurita, Y., Bull. Chem. SOC. Jpn, 1989, 62, 1501. Fagerstrorn. R., Sepponen, P., and Janne, J., Clin. Chim. Acta, 1984.143,45. Kamei, S., Ohkubo, A., Saito, S., andTakagi, S., Anal. Chem., 1989, 61, 1921. Kozial, T., Grayeski, M. L., and Weinberger, R., J . Chromat- ogr., 1984. 317, 355. Mellbin, G., and Smith, 6. E. F., J. Chromafogr., 1984, 312, 203. Miyaguchi, K., Honda, K., and Imai, K., J . Chromatogr., 1984, 303, 173. Miyaguchi, K., Honda, K., and Imai, K., J .Chromatogr., 1984, 316, 501.40 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 18 19 20 21 22 Ishida, J., Yamaguchi, M., Nakahara, T., and Nakamura, M., Anal. Chim. Acta, 1990, 231, 1. Lytle, L. T., and Hedgecock, D. G., J. Forensic Sci., 1978, 23, 550. Zweidinger, R. A., Lytle, L. T., and Pitt, C. G., J . Forensic Sci., 1973, 18, 296. Abbott, R. W., Townshend, A., and Gill, R., Analyst, 1987, 112,397. Andrews, A. R. J., and Townshend, A., Anal. Proc., 1989,26, 368. 23 Andrews, A. R. J., and Townshend, A., Anal. Chim. Acta, 1989, 227, 65. 24 Abbott, R. W., Townshend, A., and Gill, R., Analyst. 1986, 111, 635. 25 Alwarthan, A. A.. and Townshend, A., Anal. Chim. Acta, 1986, 185,329. 26 Alwarthan, A. A., and Townshend, A., Anal. Chim. Acta, 1988, 205, 261.27 Koukli, I. I., Calokerinos. A. C., and Hadjiioannou, T. P., Analyst, 1989, 114, 711. Magnesium as Modifier for the Determination of Barium by Flame Atomic Emission Spectrometry Mohammad Jerrow, lain L. Marr and Malcolm S. Cresser Chemistry Department, The University, Old Aberdeen, Aberdeen AB9 2UE Barium is a problem in North Sea oil technology, both for oil production engineers and for analytical chemists. One of the ways of increasing the productivity of an oil reservoir is to pump water down into the rock formation to maintain the hydrostatic pressure and hence to force the oil to the surface. In the North Sea fields, sea-water is the obvious choice; however, there is an obvious incompatibility between sea-water and formation water owing to the high sulphate levels in the former and the often high barium (and also strontium and calcium levels) in the latter (Table 1).When these two waters mix barium sulphate will precipitate, forming a scale and blocking either the pores of the reservoir formation or the well itself, in either instance causing loss of a well. The precipitation is dealt with by the addition of scale inhibitors; however, correct and economic dosage of these chemicals depends on a knowledge of the levels of barium and sulphate in the produced water. Table 1 Composition of sea-water and a typical formation water. All values in mg 1-1. Data taken from reference 1 Formation water Ion Na+ K+ Ca2+ Mg*+ Sr2+ Ba2+ Fe3 + c1- SO42- Sea-water 11 000 760 475 1 440 7 0.05 - 19 900 2 725 UK field 40 500 580 5 700 900 - - 70 74 000 650 Brent field 9 600 170 260 65 39 73 14 400 33 - Levels of barium in formation water may lie in the range 1-500 ppm, with corresponding calcium levels of 100-5000 ppm.Levels such as these are best determined by atomic spectrometry, but both absorption and emission flame tech- niques are known to suffer serious interferences from calcium, arising from the presence of CaOH molecular species in the flame.2 The interference may be diminished by working in a reducing flame, and preferably in a hot dinitrogen oxide - acetylene flame, to reduce the proportion of calcium present as CaOH, and by using a narrow slit-width to cut down molecular background emission for atomic emission measurements. The even higher temperatures of argon plasmas reduce further the interference from oxide species3; however, there are still problems with high levels of calcium, and of course ionic rather than atomic species of barium will predominate.Recent work on the determination of barium by DCP has demonstrated that the addition of magnesium to samples and standards alike can largely eliminate the interference of calcium on the determination of barium.4 It is shown here that the addition of magnesium is also beneficial in the determina- tion of barium in well waters by flame emission spectrometry. Experimental Instrumentation A Philips SP 9 atomic absorption spectrometer with a dinitrogen oxide burner head, running in the emission mode, was used. Reagents Calcium carbonate (Aristar grade) was used to prepare a 12 000 mg 1-1 calcium solution by dissolving it in the minimum amount of hydrochloric acid. No barium line emission could be detected with the Spectraspan I11 DCP spectrometer when a 10000 mg I-' solution prepared from this salt was aspirated, indicating a barium content of less than 5 ppm m/m in the original salt.Sodium chloride and magnesium sulphate heptahydrate (AnalaR grade) were used to prepare 15 000 mg 1-1 sodium and 15 000 mg 1-1 magnesium solutions, respectively. Samples, and standards for calibration, were spiked to contain 3000 mg 1-1 sodium and 5000 mg 1-1 magnesium above the levels naturally present. t I 0 1000 2000 3000 4000 5000 [Nal/mg I-' Fig. 1 dinitrogen oxide-acetylene flame. Ba/Na 553.6 nm Effect of sodium on the barium emission in a reducing Calibration Barium standards contained 0.5, 1, 2, 4, 8 and 10 mg 1-1 of barium.The calibration over this range was linear.ANALYTICAL PROCEEDINGS. FEBRUARY 1991, VOL 28 41 Discussion The major cation in both sea- and formation waters is sodium: this is an effective ionization suppressant for atomic emission and absorption spectrometry. In routine practice in our laboratory, samples of produced water are diluted 1 + 10 with a 3000 mg 1-1 sodium solution as ionization buffer (which will tolerate much higher concentrations of sodium as this level is safely on the working plateau), for analysis by flame atomic absorption. This approach is also applicable to the flame emission determination, and greatly enhances the sensitivity (Fig. I). The principal interference from calcium, caused by the band emission from the CaOH species, is fairly serious for the typical levels of the two elements found in well waters, even at the higher temperatures of the dinitrogen oxide - acetylene flame (curve 1 in Fig.2). However, when magnesium is present at 5000 mg 1 - 1 , the barium signal is enhanced yet again, and is no longer affected by up to 1000 mg 1-1 of calcium (curve 2, Fig. 2). This clearly makes the determination of barium both sensitive (good signals with low noise levels were obtained for 1 ppm) and interference-free under these conditions. I 1 I I I 0 1000 2000 3000 4000 5000 [Cal/pg ml-l Fig. 2 Effect of calcium on the barium emission in a reducing dinitrogen oxide-acetylene flame. +, Ba/Ca; 0, Ba/Ca, Na; and X, Ba/Ca, Na, Mg That the method is satisfactory was demonstrated by checking the recoveries from 10 mg 1 - 1 of barium spiked into several different well waters.These results, and those obtained also by atomic absorption and by DCP, are summarised in Table 2. The calculated limits of detection are 0.05 pprn by emission, 0.5 pprn by atomic absorption and 0.2 ppm by DCP. It is noteworthy that recoveries by both flame emission and flame absorption are high when magnesium is not added, although in the DC plasma the effect is hardly noticeable at the rather low calcium concentrations in these samples. It could be that there is an additional ionization suppression effect caused by the magnesium, similar to that observed by Cresser and Bandas for additional alkali metals. The interference from molecular emission from calcium species is clearly still present at high calcium levels (>lo00 mg 1-1 in the solution aspirated into the flame).The possibility of magnesium competing with the calcium for oxide ions in the reducing dinitrogen oxide - acetylene flame should be con- sidered as an explanation for the elimination of the interfer- ence for lower calcium levels; however, the difference in the stabilities of the oxides is not very great and this explanation does not seem very likely. The acetylene flow-rate remains critical when magnesium is added-a balance must be sought between having a reducing flame to produce more atoms rather than oxide species, and a hot flame to give more excited atoms. Table 2 Recoveries for well waters spiked with 10 ng 1-1 barium with and without the addition of 3000 mg 1-1 sodium and 5000 mg 1-I magnesium, expressed as % Content DCP* FAAS? FAESS (mg1-l) ~ NoMg Mg NoMg Mg NoMg Mg A 18 264 89 89 105 99 99 100 B 48 160 86 95 112 102 92 100 C 40 187 98 104 110 92 103 97 D 13 286 96 96 110 101 102 100 E 41 249 94 97 111 105 100 100 Sample Ba Ca added added added added added added * DCP = Direct current plasma atomic emission spectrometry. t FAAS = Flame atomic absorption spectrometry.$ FAES = Flame atomic emission spectrometry. It is interesting that in their classic paper, Capacho-Delgado and Sprague6 stated that in the dinitrogen oxide - acetylene flame the calcium molecular absorption interference in the determination of barium at 554 nm was eliminated: our experience is that high levels of calcium certainly do interfere in both the absorption and the emission modes.However, the addition of magnesium does, for most practical purposes, eliminate the interference from calcium, and this procedure, using flame atomic emission spectrometry, can be recommen- ded for the routine analysis of oilwell waters, as it gives a better limit of detection than atomic absorption and tolerates all the major components in these samples. The Iraqi Ministry of Higher Education is thanked for the award of a study grant to M. J. References Ogden, P. H., Chemicals in the Oil Industry, Royal Society of Chemistry, London, 1983. Welz, B . , Atomic Absorption Spectrometry, Vcrlag Chemie, Weinheim, 2nd edn.. 1985. p. 273. Montaser, A., and Golightly, D. W.. Inductively Coupled Plasmas in Analytical Atomic Spectrometry, Verlag Chemie, Weinheim, 1987.Jerrow, M., Marr, I. L., and Cresser, M. S., Analyst, 1991, 116, 141. Cresser, M. S . , and Banda, R., unpublished results. Capacho-Delgado, L., and Sprague, S . , At. Absorpt. Newsl., 1965, 4, 363. High-performance Liquid Chromatographic Determination of Some Trace Metal Ions Using a Novel Column Switching Technique Eva Ryan and Mary Meaney School of Chemical Sciences, Dublin City University, Dublin 9, Ireland Multi-dimensional column chromatography (now widely technique has been applied in thin-layer Chromatography' and known as column switching) is a powerful technique for the gas chromatography2 for many years and more recently in separation of multi-component samples.Fractions from one high-performance liquid chromatography (HPLC) .3 Column chromatographic column are selectively transferred on to one switching offers the chromatographer improved sample or more secondary columns for further separation. This throughput, separation effciency and, if a pre-column is used42 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 for concentration purposes, an increased loading on to the chromatographic system. Our objective in using column switching is primarily to achieve a desired separation in a minimum analysis time. Complementary to this aim is the need for both sample clean-up and trace enrichment prior to separation. Direct injection of biological fluids into a pre-column system for HPLC quantification of trace metal ions has been investigated.Plasma, the chosen biological fluid, is a difficult matrix for direct injection on to an HPLC column because of the high relative molecular mass lipids present. Hence extensive clean- up is required, a problem which should be easily resolved using the column switching technique. Experimental Initial experiments involved trace metal determination using a reversed-phase HPLC system first proposed by Mooney et al. 4 Efficient separation of Cr111, Zn", CuI11 and Fell1 was achieved and limits of detection (LODs) of 500 ppb were obtained. We extended the technique to include separation of A1111 and Co". Comparable LODs were obtained. The metal ions were pre-complexed prior to injection using 8-hydroxyquinoline. This ligand forms neutral chelates with several divalent and trivalent metal cations.Metal standards in the range 5-0.5 pprn were prepared by serial dilution of a SpectrosoL 1000 pprn stock solution. The standards were then mixed with 1 x 10-2 mol dm-3 8-hydroxyquinoline (an excess) to ensure complete complexation. The mobile phase required for separation contained acetonitrile (made 1 X 10-2 mol dm-3 in 8-hydroxy- quinoline) and 0.02 mol dm-3 acetate buffer (pH 6.0, made 0.2 mol dm-3 in potassium nitrate) (50 + 50). The analytical column used for separation was an LC 18 DB reversed-phase column ( 5 pm) supplied by Supelco. Results and Discussion Pre-column Selection Stage 1 in the set-up of the switching system involved selection of a suitable pre-column which would retain the metal ions when injected as their tbhydroxyquinolinate complexes.A short stainless-steel pre-column (10 x 2 mm i.d.) was chosen as the concentration column. Nucleosil CI8 showed the most favourable retention characteristics and was therefore chosen as the pre-column packing. Drain I / I \ I__ To detector Eluent Fig. 1 Column switching assembly Solvent Compatibility The next stage was to find two compatible eluents of different eluotropic strength;S one to concentrate the sample on the pre-column and the second to elute the components of interest off the pre-column and on to the analytical column. The 8-hydroxyquinoline-containing mobile phase (already de- scribed) was found to be suitable for the elution of the metal complexes from the pre-column on to the analytical column. This is designated mobile phase B.Mobile phase A had to have poor elution capability on the pre-column in order to ensure maximum concentration of the sample. The pre-column packing used was reversed-phase CI8 (5 pm); hence the solvent of least eluotrophic strength is water. However, water does not fulfil the compatibility requirement as it is miscible to only a very poor extent with mobile phase B (50% aqueous content). Various mobile phase compositions with increasing organic content were investigated: acetonitrile-water (90 + 10) was eventually chosen as it is miscible with the eluent and its elution power in the pre-column is very poor and therefore allows maximum concentration. The choice of solvents was very important to our LC system as even slight incompatibility could result in a slug of solvent travelling down the analytical column partially carrying sample components which may cause band spreading.It is also possible that the solutes of interest could precipitate under poor compatibility conditions. Instrurnentatioflechnique The instrument arrangement incorporating a six-port switching valve is shown in Fig. 1. A back-flushing technique is used to transfer the sample fraction from the pre-column on to the analytical column. In this mode, when a plasma or metal standard is introduced via the injection port, it is swept on to the concentration column by a water-acetonitrile (90 + 10) mixture by pump A and selective retention of the ligand-bound metals occurs. Endogenous plasma components are eluted to waste. Meanwhile the eluent is passed by pump B through the analytical column thus maintaining this column in a state of constant equilibrium.Valve actuation causes the eluent to flow in a back-flush mode through the concentration column from which the retained metals are desorbed and swept on to the analytical column for separation. Boundary Conditions In order to determine the boundary conditions that could be used for application and desorption of the metal ions on the pre-column, the breakthrough volumes of the first and last eluting metals were measured. The Cu11-8-hydroxyquinolinate complex elutes first with the Fell1 complex eluting last (Fig. 2). 12 6 0 tlmin Fig. 2 HPLC separation of Cull, A1111 and Fell* as their 8-hydroxy- quinolinate complexes using the column switching pre-concentration technique By varying the flow of mobile phase A the wash volumes were determined, i .e . , the volume of solvent A with which it is possible to wash the pre-column without causing elution of the retained analytes due to the washing effect of the solvent. It was found that these conditions were best guaranteed if the eluotrophic strength of mobile phase A was as low as possible [i.e., water-acetonitrile (90 + lo)]. Optimum wash volumes of 4.5 and 0.45 ml, respectively, for injected 5 pprn Fe"1 and Allll standards were obtained. A 2 pprn Cull standard had anANALYTICAL PROCEEDINGS. FEBRUARY 1991. VOL 28 43 optimum wash volume of 0.75 ml. The re-equilibration volume required by the pre-column after elution with the eluent was 0.5 ml of mobile phase A.0 1 2 3 4 5 Concentration (ppm) Fig. 3 Calibration graphs for Cu", All11 and Fe"' using the switching technique. Note the increase in sensitivity compared with a direct injection technique. ('sw' Indicates the use of the column switching technique and 'anal' that of the direct injection technique on to the analytical column) Loading The problem of mass loadability was also addressed with respect to: (1) pre-column loadability and its effect on trace enrichment; and (2) the effect of high loads on the efficiency of chromatographic separation. It was found that the loadability of the FeffG3-hydroxyquinolinate complex was far greater than that of either the AlIII- or CuIkomplex. A 900 pl volume of 5 ppm Fe"1 could be loaded before the enrichment efficiency of the pre-column decreased.A 250 pl volume each of A1111 and CuII could be loaded without loss of efficiency. Conclusions In this study it was our aim to use pre-column switching for both sensitivity and selectivity enhancement. Calibration data obtained (Fig. 3) indicate the increase in sensitivity of the technique for trace metal ion determination. Obviously selec- tivity has improved; injection of spiked plasma samples caused selective retention of the ligand-bound metals on the pre- column while endogenous plasma constituents were eluted to waste. Low levels of variability in the analysis were possible even in the absence of an internal standard because of the inherent reproducibility of the switching technique, particu- larly when compared with liquid-liquid extractions which are often multi-step and subject to artefact introduction.Detection of the metal complexes was achieved using a spectrophotometric detector operated at 400 nm. Limits of detection of the order of 50-100 ppb of Fe"1 and Cu" were obtained. Limits of detection of 10-50 ppb of A1111 were possible. References Randerath, K . , Thin Layer Chromatography, Academic Press, New York, 1965, pp. 51-53. Huber. J. F. K., Kenndler, E., Nyiry. W., and Oreans, M., 13th International Symposium on Chromatography, June 30th-July 4th, Cannes, France, 1980. Kriz, J., Adamcova, E., and Vodicka, L., Chromatographia, 1990, 29,7. Mooney, J. P.. Meaney, M., Smyth, M. R., Leonard, R. G., and Wallace, G. G., Analyst, 1987, 112, 1555. Goewie, C. E., and Hogendoorn, E.A., J. Chromaiogr., 1987, 410, 211. Separation of Urinary Organic Acids by High-performance Liquid Chromatography R. G. Anderson and N. V. Fox School of Applied Sciences, Wolverhampton Polytechnic, Wolverhampton WV? ISB The detection of increased levels of urinary organic acids is important in the clinical diagnosis of many metabolic disorders in neonates, which, if left untreated, might result in physical or mental retardation, or even death. Recent work has indicated that a link might exist between raised urinary organic acid levels and cot death.' The separation and identification of these organic acids in urine is therefore of considerable clinical importance. In the past this analysis has been carried out either by gas chromato- graphy (GC) or more recently by gas chromatography-mass spectrometry.' In either instance, however, the procedure is complex and time consuming owing to the need to produce volatile derivatives (esters) of the acids for GC.Moreover, GC-MS is not a technique at present widely available in clinical laboratories. High-performance liquid chromatography (HPLC) has also been used to detect these acids.3 The favoured conditions involve the use of ion-moderated partition chromatography in which the separation takes place on a sulphonated poly- styrene-divinylbenzene cation-exchange column with an acidic aqueous mobile phase. The mechanism is believed to be essentially a combination of ionic exclusion and a reversed- phase separation involving the backbone of the ion-exchange resin, with the sulphonic acid groups subtly modifying the separation.4 The acids generally elute in order of increasing pK, value.The purpose of this study was to examine this separation with a view to optimizing the conditions and evaluating the reliability of retention data alone as a means of identifying the individual acids. Table 1 Mean retention times of organic acids separated isocratically with 0.008 mol dm-3 sulphuric acid as eluent Mean Standard retention time/ deviation/ Acid min min n Oxalic 5.90 0.10 9 Citric 7.20 0.10 10 Maleic 7.30 0.19 5 2-Ketoglutaric 7.55 0.13 9 Pyruvic 8.55 0.06 7 Ascorbic 8.60 0.30 8 2-Ketobutyric 8.85 0.10 10 Methylmalonic 9.35 0.36 8 Ketoisovaleric 9.55 0.12 9 Succinic 10.45 0.11 7 Lactic 11.10 0.17 5 Uric 15.15 0.14 8 Adipic 19.85 0.29 6 Hippuric 47.65 0.95 7 3-Phenylpropionic* 103.50 2.95 12 * Internal standard.44 ANALYTICAL PROCEEDINGS.FEBRUARY 1991, VOL 28 The initial conditions involved separation on a Bio-Rad 300 X 7.8 mm i.d. Aminex HPX87H cation-exchange column using 0.008 mol dm-3 sulphuric acid as eluent at a flow rate of 0.8 ml min-1 at room temperature. Detection was by UV at 210 nm. Each acid was injected separately as a 2 p.1 aliquot of 0.01 mol dm-3 concentration. Table 1 shows the means and standard deviations of these retention times. It can be seen from these results, which are typical of those of other workers,5 that not all the acids are well resolved from each other and that the late acids elute with unacceptably long retention times. Attempts were therefore made to improve on these standard separation conditions.Firstly, the sulphuric acid concentration was varied from 0.001 to 0.08 rnol dm-3. However, no statistically significant variations in retention times were noted. Therefore, acetonitrile was added to the eluent at concentrations of 10, 15 and 20%. This had the effect of reducing the retention times of all the acids such that they eluted within about 40 min. However, the resolution of the early eluting acids had deteriorated. Therefore, a gradient elution system was investigated. The conditions adopted are given in Table 2. Table 2 Conditions for HPLC separation Eluent composition Elapsed time/ 0.008 rnol dm-3 Acetonitrile &I3 100 0 13-25 100-80 0-20 25-45 80 20 Table 3 shows the retention times thus obtained and standard deviations for triplicate determinations.The results indicate a considerable saving in total analysis time, together with a significant improvement in the resolution of the early eluting acids. Attempts were made to improve the reproducibility of the retention times by operating the column under conditions of min sulphuric acid (% j (Yo 1 Table 3 Separation of the acids under gradient elution conditions Mean Standard retention time/ deviation/ Acid min min Oxalic 6.16 0.03 Citric 7.17 0.03 2- Ke tog1 utaric 7.78 0.03 Maleic 8.10 0.01 Ascorbic 8.60 0.02 Ketoisovaleric 9.60 0.25 Succinic 10.25 0.24 Lactic 10.65 0.27 Uric 13.20 0.09 Hippuric 33.33 0.70 3-Phenylpropionic 43.41 1.70 Pyruvic 8.55 0.02 2-Ketobut yric 9.70 0.02 Methylmalonic 9.90 0.15 Adipic 14.35 0.35 controlled temperature. When the column temperature was set at 25"C, the standard deviations for the retention times of oxalic, methylmalonic and adipic acids were all significantly reduced, thus improving the reliability of their identification. It is to be assumed that a similar improvement would be found for all the other acids.Increasing the column temperature to 45 "C had the effect of improving the resolution of some of the early eluting acids by changing the selectivity of the separation. In particular, methylmalonic acid eluted before ketoisovaleric acid. References 1 Green, A.. BI-. J . Hosp. Med.. 1989,41,427. 2 Tanaka, K., Hine, D. G., West-Dull, A., and Lynn, T. B., Cfin. Clzem., 1980, 26, 1839. 3 Bennett, M. J . , and Brady, C. E . , Clin. Chem., 1984, 30, 542.4 Jupille, T., Gray, M., and Black, B., Am. Lab.. 1981. 8. 80. 5 Rumsby. G.. and Belloque, J., Cfin. Chim. Acta, 1987, 163,171. Investigation of ln Situ Concentration of Hydride Forming Elements in a Graphite Furnace Atomiser Muhammad Mansha Chaudhry, Allan M. Ure, Brian G. Cooksey and David Littlejohn" David J. Halls Trace Element Unit, Institute of Biochemistry, Royal Infirmary, Castle Street, Glasgow G4 OSF , Department of Pure and Applied Chemistry, University of Strathclyde, Cathedral Street, Glasgow G? ?XL It has been demonstratedl-3 that gaseous hydrides can be collected on the surface of a graphite furnace atomiser to improve detection limits in the atomic absorption spectrometry (AAS) determination of elements such as arsenic, bismuth, germanium, antimony and selenium. Deposition of the hydrides occurs at a lower temperature and the efficiency of collection is enhanced if a palladium solution is injected into the tube and reduced to form palladium metal before introduc- tion of the hydride gases. In most studies, a manual procedure is used whereby the hydride is transferred into the atomiser tube via a glass capillary which is positioned in the central injection hole.In this work, automation of the procedure has been attempted using a commercially available attachment designed for graphite furnace probe atomisation. The useful- ness of the method in analysis has been tested by determination * Author to whom correspondence should be addressed. of arsenic and germanium in sea water and arsenic in a urine reference material and in ultrapure hydrochloric acid.Experimental A Philips SP9 graphite furnace, PU9095 video furnace pro- grammer, PU9090 data graphics module and SP9 atomic absorption spectrometer were used. For some studies a probe attachment was used with the SP9 atomiser to introduce the hydride transfer capillary tube horizontally into a pyrolytic graphite coated tube. However, most measurements were made with the tube mounted in the normal position in the SP9 furnace. Prior to hydride generation, samples were acidified by addition of Aristar hydrochloric acid at concentrations of between 0.5 and 3 rnol 1-1 depending on the element in question. The hydrochloric acid intermediate stock solution (6 rnol 1-1) was purified by addition of 1% (m/v) NaBH4 asANALYTICAL PROCEEDINGS, FEBRUARY 1991.VOL 28 45 described previously2 to reduce the reagent blank concentra- tion. The NaRH4 solutions were prepared fresh each day by dissolving the required mass of reagent in water and cooling in ice until used. A 200 mg 1-1 solution of palladium as palladium nitrate was prepared by dilution of a palladium solution supplied by Johnson Matthey. In the procedure adopted, 50 pl of palladium solution (200 mg I - I ) , equivalent to 10 pg of Pd", was injected into the furnace and dried for 30 s at 150°C. The temperature of the tube was then raised to 800°C for 15 s to reduce the Pd*+ to PdO. Hydride vapours were generated in the usual way in a 50 ml flask containing 0.2-10 ml of sample solution acidified to 0.5-3 mol I- 1 with purified HCI.The production of hydride was initiated by addition of 1 ml of NaBH4 solution (0.5-2% m/v) to the acidified sample solution. The vapours were swept from the reaction vessel by a nitrogen gas flow through a silica glass capillary inserted in the sample introduction hole of the atomiser tube. A transfer time of 75 s was normally used. The temperature of the graphite tube during deposition was varied depending on the element to be determined. After hydride deposition, the capillary was taken out of the tube and the atomiser heated to 2600°C at 2000°C s-1 (zero ramp) under gas stop conditions to generate the atomic absorption signal. Three modes of injecting the palladium solution and hydride vapour into the tube were investigated (Fig. 1). Method ( a ) involved manual injection of the palladium solution through a hole at the top of the tube, followed by vertical injection of the hydride vapour through the glass capillary placed in the same hole.Method ( 6 ) used a two-hole tube. The palladium solution was injected by the autosampler into the SP9 graphite tube through a hole cut at 45" from vertical (the normal orientation for this atomiser). The hydride vapour was then introduced by manual vertical injection via the capillary positioned in a second hole at the top of the tube. Method ( c ) also involved a two-hole tube and used the SP9 autoprobe assembly to automate the injection of the hydride vapour into the tube. The palladium solution was injected via the autosampler, as in method (6). The assembly normally used for graphite probe atomisation was modified to allow the glass capillary to be moved horizonally in and out of the tube through a second hole cut 45" below the normal injection hole.With this procedure the angle between the deposition of palladium and hydride injection was about 90 ". Sample Preparation The samples analysed were Clyde Estuary sea-water (stored in polyethylene bottles), Memory Spec hydrochloric acid (Micro- Image Technology Ltd., Derby) and Lanonorm Metalle 1 synthetic urine standard (Behring Institute, Marburg, Ger- many). The sea-water and hydrochloric acid were analysed directly. The reconstituted, synthetic urine standard was digested as follows. A 1 ml volume of urine was placed in a PTFE cup in a steel digestion bomb along with 2 ml of concentrated HN03 and 1 ml of concentrated HCIOJ (Aristar grade) and digested at 120-130°C for 3 h in an oven.The sample was cooled, the HN03/HC104 evaporated to near dryness on a hot-plate and the residue diluted to 10 ml with 3 mol I-' purified HCI prior to generation of the hydride. The blank was prepared in an identical way. Results and Discussion The addition of 10 pg of palladium to the atomiser tube enhanced considerably the analyte collection efficiency and caused decomposition of the hydride to occur at much lower temperatures than those observed without the addition of palladium. The efficiency of arsenic deposition did not change over a range of temperatures between 200 and 900°C when 10 pg of palladium were added to the tube. In contrast, an optimum deposition temperature of 700 "C was observed in the absence of palladium and the AAS signal sensitivity and precision were considerably poorer than for deposition with palladium.The presence of palladium allowed deposition of germanium to proceed at tube temperatures between 200 and 900"C, although double AAS peaks were observed below 400 "C. These observations are similar to those reported elsewhere'J and support the suggestion that Pd causes catalytic decomposition of the hydride vapours, which allows the use of lower deposition temperatures and enhances the analyte collection efficiency .4 The injection procedures described above and in Fig. 1 were assessed by comparing the AAS signals obtained for german- ium when GeH4 vapour was decomposed in the graphite tube.The germanium signals obtained with method (6) were 40-50% smaller than those obtained with method (a). As a similar result was obtained for the signals for aqueous germanium solutions injected and atomised in the one and two-hole tubes, it was assumed that the poorer sensitivity was due to increased diffusional loss of germanium atoms in method ( b ) . The germanium signals obtained with method (c) were 5&70% smaller than with method (a), partly caused by the effects of increased diffusional loss of germanium atoms through the extra hole during atomisation, and partly because of the poorer germanium collection efficiency that occurred when the hydride flow was not passed directly on to the palladium deposit. As the catalytic effect of palladium on hydride decomposition is a surface phenomenon, it is not surprising that optimum collection of germanium was achieved under conditions which maximised the interaction of the H yd ri de Ilh Graphite tube Pd deposit w Hydride Pd Hvdride - motor Fig.1 Operational modes for introduction of Pd and hydride into the graphite furnace: ( a ) , manual, vertical Pd injection and manual introduction of hydride; ( b ) , autosampler injection of Pd and manual introduction of hydride; ( c ) , automatic introduction of both Pd and hydride injected vapour with the pa!ladium deposit. In all further studies, method (a) was employed for injection and decomposi- tion of the hydride vapours. The effects of various ions known to cause interference effects in hydride generation procedures were investigated. No reduction in the AAS signal of arsenic (0.2 or 0.4 ng in 5 ml) was observed when the sample solution contained up to 10 mg 1 - 1 of nickel(I1) or iron(III), or up to 100 mg 1-1 of iron(I1).When copper(I1) was present at a concentration between 0.1 and 10 mg 1-1 the AAS signal for arsenic was reduced by up to 60%. However, at concentrations greater than 10 mg 1-1 of copper(II), a precipitate was observed in the reaction vessel and only a 10-20% reduction in the arsenic AAS signal was46 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 observed. The effects of nickel(I1) and iron(I1) on arsenic are similar to those reported previously by Welz and Schubert- Jacobs.5 The results obtained for the samples mentioned previously are given in Table 1.Interferences were negligible in the determination of arsenic and germanium in sea-water and consequently satisfactory results were obtained by direct use of aqueous calibration standard solutions. A HCI concentration of 3 moll-1 was used to determine arsenic in sea-water. At this concentration, efficient generation of arsine was obtained for both arsenic(II1) and arsenic(V). The other two samples were analysed by standard additions. In the determination of arsenic in the urine, a slight suppressive interference was caused by the perchloric acid used in the digestion procedure. Table 1 Analysis of samples by hydride-ETAAS Concentratiodyg 1 - 1 Element Sample Determined Reference As Memory Spec 0.15 f 0.02 As Lanonorm 1 19.9 f 0.9 19.7 f 2.7 As Clyde estuary 1.90 f 0.14 Ge Clyde estuary 3.033 ? 0.001 Hydrochloric acid Synthetic urine sea-water sea-water Conclusions This work has confirmed the conclusions of other workers that the deposition of small amounts of palladium can greatly enhance the efficiency of hydride decomposition and analyte collection in a graphite furnace atomiser.The collection efficiency and the precision of AAS signals are improved if the hydride gases are injected directly on to the palladium deposit. It is likely that under these conditions, more efficient adsorp- tion of the hydride and hydrogen gases on the palladium is achieved. Application of the graphite tube collection procedure to the analysis of a variety of samples has confirmed the value of this approach in the determination of pg 1-1 levels of arsenic and germanium. As reported elsewhere,G the purity of the HCI and NaBH4 reagents is the major limitation to the use of this method in ultra-trace analysis.In this work, an attempt was made to purify the HCI prior to use and the concentration of NaBHj was minimised to reduce the AAS signals obtained from the reagent blank. In the interference studies and sample analysis, acceptable blank concentrations of arsenic were achieved by using 0.5-1% m/v NaBH4. References 1 Sturgeon, R. E . . Willie, S. N.. and Berman, S. S . . J . Anal. At. Spectrom., 1986, 1, 115. 2 Zhang, L., Ni, Z.-m., and Shan, X.-q., Spectrochim. Acta, Part B . 1989, 44, 339. 3 Zhang. L . , Ni, Z.-m., and Shan, X.-q., Spectrochim. Acta, Part B . 1989, 44, 751. 4 Sturgeon, R. E., Willie, S. N., Sproule, G. I., Robinson, P. T., and Berman. S. S., Spectrochim. Acta, Part B , 1989,44, 667. 5 Welz, B., and Schubert-Jacobs, M., J . Anal. At. Spectrom., 1986, 1, 23. 6 Doidge. P. S., Sturman, B. T., and Rettberg, T. M., J . Anal. At. Spectrom., 1989,4,251. ROYAL SOCIETY OF CHEMISTRY/ROYAL MICROSCOPICAL SOCIETY EXTENDING YOUR VISION-WHY NOT USE A MICROSCOPE? April 16th, 1991, London Tucked away in the corner of many chemical laboratories is a weird, complex artifact of glass and metal called a 'microscope'. This instrument is capable of achieving the most startling transformation of any object presented to it, not only making it appear much larger than it really is but also, more importantly, revealing in the most wonderful detail its intimate organization. Yet most staff, trained or not, have forgotten that it is there, or what it can do for them. This meeting is intended to give to chemists (and others!) a flavour of what using a microscope might do for them; to microscopists it will, hopefully, extend their feeling for the wide range of chemical information that might be obtained with their favourite instrument. This meeting will cover a wide range of practical topics, presented by lecturers who are acknowledged experts in their field. Dr. Walter McCrone (an Honorary Fellow of the Royal Microscopical Society) is well known to members of that society. Mr. E. Braxton Reynolds is a public analyst of great experience. Mr. Don Clark has expertise in obtaining infrared spectra from very small samples. Appropriately enough, the first session after lunch will commence with Dr. Olga Flint surveying applications of microscopy to food science. Her paper is followed by that of Dr. Terry Threlfall, a chemist with many years' experience in the chemical and pharmaceutical industries. Professor George Gray was instrumental in introducing the range of electro-optic liquid crystals which have made displays such as those used in watches a reality. Dr. John Lock, a forensic scientist is, of course, always concerned with obtaining the maximum amount of information from infinitesimally small samples. The meeting is to be held at the Institute of Child Health, Guilford Street, London. The registration fee will be f25 for Members of the RSC and the RMS or f35 for non-members. Enquiries should be addressed to Miss L. Dixon, CMB Packaging Technology plc, Denchworth Road, Wantage, Oxfordshire OX12 9BP.

ISSN:0144-557X    

DOI:10.1039/AP9912800037

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, FEBRUARY 1991. VOL 28 47 Equipment News Atomic Absorption Spectrometer The 4100 ZL is a totally automated multi-element analysis system with full computer control of all components: spectrometer, furnace, autosampler and optional accessories. Its unique trans- verse heated graphite tube design with an integrated L’vov platform provides a uni- form temperature profile over the entire tube length. The combination of uniform tube temperatures, exceptionally rapid heating and integrated L’vov platform provides significant time saving, simpli- fied method development and improved accuracy and measurement reliability. The 4100 ZL is the first atomic absorption spectrometer using the longitudinal Zee- man-effect background correction. Bodenseewerk Perkin-Elmer GmbH, Abt.S-SW-Postfach 101164, D-7770 Uberlingen/Bodensee, Germany. Software for Near Infrared Spectroscopy New software brings together near infrared spectroscopy and Fourier trans- form to provide a unique system that eliminates the need for laboratory sample preparation. The InfraAlyzer FT soft- ware consists of four powerful, easy to operate modules: the data base, data analysis, basic application and graphics modules. A significant feature is the provision of a fibre optics probe which can be placed directly in the sample sack or container, thus removing sample prepara- tion procedures. The rapid Fourier trans- form system has been purpose designed for near infrared applications and offers a scan time of approximately 5 s, including FFT and reference scan. Bran and Luebbe (GB) Ltd., Scald- well Road, Brixworth, Northampton NN6 9UD. Spectrum Analyser The newly launched Hewlett-Packard spectrum analyser is available for hire.Using a revolutionary new digital sweep, the HP3588A is claimed to conduct nar- row band frequency sweeps 400 times faster than any other instrument. As a result, a single sweep which previously could take an entire day can now be conducted in 2 min. Covering frequencies between 10 Hz and 150 MHz, the HP3588A provides, in swept spectrum mode, the performance and features of traditional swept tuned analysers, with the addition of digital filters to provide improved frequency resolution to only 1.14 Hz. Narrow band zoom mode uses an implementation of fast Fourier transform to provide the fastest possible measure- ments with even better levels of resolu- tion.Also featured is built-in autocalibra- tion to compensate signal amplitude for absolute temperature and frequency response errors. As a result, amplitude accuracies of better than k0.4 dB are obtained. Livingston Hire, Livingston House, 2-6 Queens Road, Teddington, Middlesex TWll OLB. Software for Chromatography New software allows integration of chro- matography results directly with Peakpro chromatography software with Lab Manager LIMS. Results can be extracted, reviewed and automatically posted to the Lab Manager LIMS database without exiting the LIMS software. The use of the new software in conjunction with Peakpro and Lab Manager eliminates the need for manual entry of chromatographic results into the database. Beckman, Progress Road, Sands Indus- trial Estate, High Wycombe, Bucking- hamshire.Two-dimensional Chromatography Plates Multi-K Dual-Phase TLC Plates offer the convenience of using both normal and reversed-phase techniques on the same plate. Samples can be developed success- ively in two dimensions without the use of separate preparation steps or transfer from one plate to another. Most popular is the Multi-K CS5 type, comprising a 3 cm band of KC18 bonded phase silica abutting a 17 cm normal phase silica gel area. The Type SCS, on the other hand, has a contiguous 3 cm silica gel strip on a KC18 RPTLC plate. The former is useful for samples contaminated with lipophilic material, the latter for the removal of polar hydrophilic contaminants.A Multi- K researcher pack is available, providing a layer selection for determining the best methodology for complex separations. Whatman Scientific Ltd., Springfield Mill, Maidstone, Kent ME14 2LE. DNA Sequencing Kit Perkin Elmer Cetus has introduced a DNA sequencing kit based on Amplitaq (R) Polymerase. It contains all the reagents for sequencing except radio- labelled dATP and electrophoresis reagents and provides for a reaction time of approximately 10 min. An additional kit using 7-deaza dGTP based termination mixes is available for use with the main kit. Also offered is cloned Amplitaq enzyme at an optimum concentration for sequencing applications. Perkin Elmer Ltd., Maxwell Road, Beaconsfield, Buckinghamshire HP9 1QA. pH Meter No bigger than a standard size test-tube, the Champ pH tester offers pH readings across the full 0-14 pH range.It is easy to use: simply switch on and dip in sample for an accurate reading. A double-junc- tion electrode is incorporated. Also featured are a battery life of 1000 h and a pocket clip. The Champ costs f22.25 and comes with a 6 month parts and labour warranty. Hanna Instruments Ltd., Happy Valley Industrial Park, Primrose Hill, Kings Langley, Hertfordshire WD4 8HZ. Conductivity Meter Cell Radiometer have developed a cell, the CDC304T, for use with their laboratory conductivity meter. This cell has a built-in temperature sensor, so that both conduc- tivity and temperature can be measured simultaneously and any temperature cor- rections necessary are made automatic- ally by the meter.Radiometer Ltd., The Manor, Manor Royal, Crawley, West Sussex RH1O 2PY. Refractometer The GPRll-37X refractometer is a de- velopment of the GPRll-37. The new instrument retains the advantages of wide range (1.32-1.70 RI), simplicity of use, choice of four scales [refractive index, sugar per cent. (BRIX), temperature corrected BRIX and a user program- mable scale] and a watertight base unit. It reads to 0.00005 RI units or 0.05% sugar content. Index Instruments Ltd., Bury Road Industrial Estate, Ramsey, Huntingdon PE19 1NA. Field Testing Products for Environmental Analysis Chlor-n-Oil and Chlor-D-Tect are screen- ing kits for electrical insulating fluids and for soil testing. Chlor-n-Oil is a kit con- taining everything necessary to perform the procedure on-site in less than 5 min and is of most interest to the electrical industry.Chlor-n-Soil is a similar kit for determining the presence of PCBs in soil at the SO ppm level. Simple to use, the kit takes only 10 min to perform the test. Panda Environmental Supplies Ltd., Weybridge, Surrey KT13 9UT. On-line Gas Purity Analyser The Model 402R monitors the purity of gases by measuring hydrocarbon contami- nation levels. Using the makers’ flame ionisation detector, it is ideal for monitor- ing the purity of a number of gases, such as oxygen, nitrogen, hydrogen and argon.48 ANALYTICAL PROCEEDINGS. FEBRUARY 1991. VOL 28 It offers easy and convenient mounting in standard 19-in instrument racks. Teledyne Analytical Instruments, The Harlequin Centre, Southall Lane, Southall, Middlesex UB2 5NH.Outgassing Testing Service An outgassing testing service to ASTM- E-595 and NASA SP-R-0022A is offered with the guarantee of a 14 days turn around from receipt of samples. Samples of a minimum 2 g are subject to a vacuum 10-6 Torr, under which conditions low relative molecular mass materials outgas; Dunlop Adhesives o a test report details the total mass loss (TML), collected volatile condensible materials (CVCMs) and the amount of water vapour recoveredhetained (WVR). Further, a qualitative evaluation of the physical appearance and coverage percentage of CVCMs is provided, all in confidence. Dunlop Adhesives, Chester Road, Birmingham B35 7AL. On-line TOC Analyser The Shimadzu On-Line measurement system comprises the recently introduced TOC 5000 intelligent total organic carbon analyser coupled with the CSM-500 on- line sampler.The TOC 5000 has a detec- tion range between 4 ppb and 400 ppm. The new system includes a number of advanced features including automatic calibration and fully programmable oper- ation. Dyson Instruments Ltd., Hetton Lyons Industrial Estate, Hetton, Houghton le Spring, Tyne and Wear DH5 ORH. Gas Analyser Targeting applications in hazardous waste and soil gas monitoring, Livingston Hire offer the HNU HW-101 for rental. Fea- turing a moisture resistant ion chamber and a pump to draw samples from a radius of over 50 ft, the new instrument is based on the PI-101 photoionisation detector. It features interchangeable probes with 11.7, 10.2 and 9.5 eV lamps. As the instrument is not sensitive to methane, non-methane hydrocarbons in the atmos- phere can be measured directly.The instrument is portable. Livingston Hire, Livingston House, 2-6 Queens Road, Teddington, Middlesex TWll OLB. Calibration Gases Bedfont has been appointed exclusive distributor for Intermar gas products. utgassing equipment Intermar provides a range of high-purity gases and special gas mixtures for a wide range of applications including calibration of breathalysers, explosimeters and toxi- meters. The range includes leak detection standards, LPGs, natural gases and many others. Bedfont Technical Instruments Ltd., Bedfont House, Holywell Lane, Upchurch, Sittingbourne, Kent ME9 7HN. Scales The high capacity PM scales, namely the PM30-K, the PM34-K DeltaRange and the PM30000-K, now have a weighing capacity of 32 kg.They feature built-in calibration which can be initiated by a keystroke and which runs automatically, thanks to a built-in motor. Mettler-Toledo AG, CH-8606 Greifensee, Switzerland. Microfiltration Device Filter Slides, each consisting of a 7 cm glass microfibre (GFK) filter circle ultrasonically welded into a rigid poly- carbonate frame to expose a filtration area of 38 cm2, can be handled by laboratory robots, even when wet, with- out the filter being touched. They can be dried at 105 "C and sterilised by autoclav- ing at 121 "C. Each filter holder is individually numbered with both a serial number and a barcode. Filter Slides are packed in boxes of 100. Whatman Scientific Ltd., Springfield Mill, Maidstone, Kent ME14 2LE.Fume Cupboards Subject to aerodynamic considerations, fume cupboards can be made to exact dimensions requested by customers. Outer casings are of fire-retardant 18 mm marine plywood, offering strength and reliability as well as effective protection against any explosion of substances han- dled within the cupboard's inner cham- ber. A total of 10 cupboards have been supplied to the University of St. Andrews Department of Chemistry for use in four areas of research: the study of enzymes, the synthesis of drugs, the development of polymers and the preparation of extremely high-purity gaseous com- pounds. Holliduy, Fielding Hocking fume cupboardsANALYTICAL PROCEEDINGS, FEBRUARY 1991. VOL 28 49 Holliday, Fielding Hocking Ltd., Shan- non Street, Leeds LS9 8SS. Particle Size Analyser The latest addition to the makers’ Micro- trac Series 9200 particle size analysers is a compact (4 x 6 x 15 in) ultrafine particle analyser that measures particles from 0.005 to 3 pm with exceptional speed, ease and reliability.A dramatically shor- tened optical path tolerates a wide range of sample concentrations, giving oper- ators more leeway when preparing samples. This innovative sensing tech- nique also produces more robust measurements with much higher signal to noise ratios, resulting in substantially more accurate and repeatable submicron particle sizing. The Microtrac Series 9200 provides a comprehensive modular system for measuring all materials ranging from 0.005 to 700 pm. Leeds and Northrup Ltd., Wharfdale Road, Tyseley, Birmingham B11 2DJ. On-line Distillation Capability for Continuous Flow Analytical System The TrAAcs 800 range of continuous flow analytical systems for environmental analysis has been extended to include on-line distillation capabilities. The de- velopment of a heating bath allows the benefits of TrAAcs 800 to be applied to methods requiring distillation, providing automatic on-line analysis of phenols, free and complex cyanides and other compounds. Bran and Luebbe (GB) Ltd., Scald- well Road, Brixworth, Northampton NN6 9UD. Literature The Hitachi Newsletter features items on microscopy, including one on the U-6000 visible region spectrophotometer, which brings a successful marriage of spec- trometry and microscopy. There is a competition to devise a name for the Newsletter. Hitachi Scientific Instruments, Nissei Sangyo Co. Ltd., Hogwood Industrial Estate, Finchampstead, Wokingham RG114QQ. A brochure gives details of SW511 and SW521 bottle top dispensers, several models of which are available. Camlab Ltd., Nuffield Road, Cambridge CB4 ITH. Camlab Product Information, September 1990, covers a range of topics, including electrodes for pH meters, products for TLC, a digital micropipette and several others. Camlab Ltd., Nuffield Road, Cambridge CB4 1TH.

ISSN:0144-557X    

DOI:10.1039/AP9912800047

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, FEBRUARY 1991. VOL 28 49 SAC Silver Medal Nominations are invited for the award of the SAC Silver Medal, which is for the encouragement of young scientists work- ing in any field covering the practice and teaching of analytical chemistry. The award is accompanied by a cash prize and is normally made annually to the candi- date who, in the opinion of the AD Council, has made the greatest contribu- tion and whose work has made the most significant impact on any branch of ana- lytical chemistry. In addition, the future promise of the candidate is taken into consideration. It is hoped to provide an opportunity for the successful candidate to deliver a lecture to the Division on a suitable occasion subsequent to the presentation of the Medal. The rules are as follows: 1.The award of the Silver Medal will normally be considered annually by the Honours Committee, acting on behalf of the Council of the Division, but an award may not be made if it is considered that the work of no candi- date reaches the required standard. 2. Candidates must be British subjects of 35 years of age or under at January 1st in the year in which the award is made. Evidence of age will be required. 3. The merits of the candidate’s work may be brought to the notice of the Council by any person (being a mem- ber of the Analytical Division of the Royal Society of Chemistry) who desires to recommend the candidate by letter addressed to The President, Analytical Division, The Royal Society of Chemistry. The letter should be accompanied by a short statement of the candidate’s career (date of birth, education and experience, degrees and other qualifi- cations, special awards, etc., with dates, and any other relevant informa- tion) and a list of titles of, and refer- ences to, papers or other works pub- lished by the candidate, independently or jointly. The 10 publications con- sidered most significant to the award50 ANALYTICAL PROCEEDINGS.FEBRUARY 1991, VOL 28 should be highlighted and reprints of the three most important papers sub- mitted with the nomination. 5 . 4. The award will be made on an over-all assessment of the candidate’s contri- bution, the impact of hidher work and 6. hidher future promise in any field covered by the principles, teaching and practice of the analytical sciences.No 7. restriction is placed as to where the work is conducted. The committee assessing the applica- tions shall be at liberty to call any candidate for interview. The successful candidate will receive a sum of money in addition to the Medal. The decision of the Council shall be final. 8. Any alteration to these rules shall be subject to the approval of the Council. Recommendations for the next award should be made to The President, Ana- lytical Division, The Royal Society of Chemistry, Burlington House, London, W1V OBN, by March 28th, 1991. Chair for Analytical Chemist We are pleased to report that Dr. J. D. R. Thomas of the University of Wales College of Cardiff (President of the Analytical Division and the former Chairman of the Analytical Editorial Board of the Royal Society of Chemistry) has been appointed to a Personal Chair in the School of Chemistry and Applied Chemistry.ROYAL SOCIETY OF CHEMISTRY: ANALYTICAL DIVISION The Annual Meeting on RESEARCH AND DEVELOPMENT TOPICS IN ANALYTICAL CHEMISTRY will be held at Aberdeen University on July 9th and loth, 1991 The 1991 Meeting will be the twenty-eighth in the series. Papers and poster presentations are invited describing work carried out by postgraduate research students in universities and colleges and by young research workers in industrial and other establishments. Oral contributions are to be presented by the student or his industrial counterpart in 20-minute lectures. The number of oral contributions is limited in order to balance the over-all programme. Titles of oral papers or posters with the name(s) of the author(s) and a summary of 100-150 words should be sent by February 28th, 1991, to the Secretary, Analytical Division, The Royal Society of Chemistry, Burlington House, Piccadilly, London WIV OBN. A limited number of bursaries will be available to the presenters.

ISSN:0144-557X    

DOI:10.1039/AP991280049b

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 51 Conferences and Meetings First International Congress on Volatile Organic Compounds March 4-8, 1991, Maastricht, The Nether- lands The first international congress on Volatile Organic Compounds (VIC’s) will be held in the MECC Conference Centre, Maastricht. It will be hosted by an organizing committee consisting of Dutch Government Officials and representatives from several branches of Dutch industries. VOCs are a large group of (chemical) compounds that are being used in a wide range of products and production pro- cesses. The emissions of VOCs constitute an increasing threat to human health and to the global environment. During the last few years increasingly more research has been done by universities and industries to find ways to reduce these emissions.However, research and the implementation of measures can only be effective if this is done in an international context. Therefore it is import- ant that knowledge is shared and that an in- ternational information network is being created. The Maastricht VOC congress will pro- vide the necessary international forum where this information exchange can happen. For the first time a large group of international experts on the scientific economic, policy, so- cial and health related aspects of VOCs will meet in one congress. The expected 400-600 participants will be addressed by a number of keynote and parallel speakers from Austria, Czechoslovakia, France, Germany, Italy, The Netherlands, Soviet Union, Sweden, Switzer- land, United Kingdom and United States.More information is available from VOC Congress Organising Committee, mr. Ruud van Zeijl, c/o Consultium, Emmapark 1, 2595 ES The Hague, The Netherlands. The Chemical Safety of Food March 27,1991, Chorleywood Food Safety is currently attracting a lot of interest from customers, the Government and the Media alike. The conference aims to pro- vide an overview of the present situation by reviewing the areas giving rise to most con- cern and considering what can be done to improve the position. It will be held at the Flour Milling and Baking Research Associ- ation. Topics for discussion will include natural toxins, agrochemical residues and contamina- tion from environmental sources. The relative importance of these will be con- sidered, with reference to any existing legis- lative controls and monitoring.Further details can be obtained from Angela Lonergan, FMBRA, Chorleywood, Hertfordshire WD3 5SH. Alternative Plasma Sources March 28,1991, Plymouth This meeting, which is sponsored by Atomic Spectrometry Updates and the Atomic Spec- troscopy Group of the Royal Society of Chemistry, will be held in Polytechnic South West. The last two decades have seen plasmas become widely established as spectral, atom and ion sources in analytical spectroscopy. Much attention has focused on the inductive- ly coupled plasma (ICP). However, several alternative plasma sources, including the microwave induced plasma (MIP), direct cur- rent plasma (DCP), laser-produced plasmas and glow discharge type sources, Lave been developed and successfully applied in several areas.This meeting provides an international perspective on current research in this im- portant area of atomic spectroscopy. The speakers will include: Professor R.M.Barnes (University of Massachusetts, USA), ‘Alternative Plasma Sources, ICP and MIP Discharges’; Professor J.-M. Mermet (University Claud Bernard, Lyon, France), ‘Laser-produced Plasmas: Research Toys or Routine Analysis Tools?’; Dr. M. Thompson (Birkbeck College, University of London), ‘ICP-The Formative Years’; Dr. J.R. Dean (Newcastle-upon-Tyne Polytechnic),‘Samp- ling Strategies for a Gas-Jet Enhanced Sput- tering Device’; Dr. J.A. Armstrong (Solway River Purification Board, Dumfries), ‘Envi- ronmental Analysis by DCP’; Dr. B. Fairman (University of Oviedo, Spain), ‘Sample Intro- duction Phenomenon Using DCP’ ; Professor D.Littlejohn (University of Strathclyde), ‘An Analytical Assessment of FANES for Trace Element Determination’. For further information contact Dr. S . Hill, Department of Environmental Sciences, Polytechnic South West, Drake Circus, Ply- mouth PL4 8AA. Edinburgh Science Festival April 1-1 4,1991, Edinburgh The following lectures may be of interest to chemists: ‘Exploding Custard and Other Easy Experiments’, by Ian Russell; ‘Fun and Games with Liquid Air’, by David Nicholls; ‘Strike a Light’, by John Emsley; ‘On Being a Bit Green’, by John Emsley; ‘New Win- dows Into the Human Brain’, by Herman Ba- chelard; ‘Oscillating Reaction and Brain Stimulation of Scientific Imagery’, by Paolo Manzelli; ‘Chemists are Going Green’ by S.Roberts; ‘Catalytic Antibodies’ by Michael Blackbum; ‘Drug Abuse in Sport - the Ath- lete’s Doctor’s Perspective’, by Elizabeth McSwann; ‘Drugs in Sport’, by David Cowan; Panel Discussion on Drugs in Sport with Drs. McSwan and Cowan together with Professor P.F. Radford and Professor M.B.T. Lambert. For further information on the Festival and a full programme contact Edinburgh Science Festival Ltd., 20 Torphichen Street, Edinburgh EH3 8JB. Fifth Annual European Symposium on Good Clinical Practice In Europe April 18-19,1991, Barcelona, Spain The Topics which will be covered at this two- day event include: GCP-an update on EC Directives; a comparison of GCP guidelines across the EC; supranational auditing of GCP compliance; adapting standard opera- ting procedures to EC guidelines; cross rec- ognition of ethics committees; GCP in the US; financial implications of GCP; economic consequences of GCP in drug development.For further information please contact Hi- lary Pendall, Bath House (3rd Floor), 56 Hol- born Viaduct, London EClA 2EX. Environmental Issues: Their Likely Im- pact on the Metals Processing and User In- dustries May 15-1 7, 1991, Amsterdam, The Nether- lands Concern over the effect of metallurgical pro- cessing operations on both the health of oper- atives and the local population, and on the environment in a global context, is resulting in the enactment of legislation which will have a profound influence in this decade on how the metals industry conducts its oper- ations.Some 40 papers have been accepted for presentation at the BNF-Fulmer 8th Inter- national Conference to be held in Amster- dam. These papers will inform delegates on the technology which is either developed or under development, and which will enable companies to operate both profitably and sat- isfactorily whilst complying with present or impending legislation. Each session will open with a keynote address given by a lead- ing expert in the particular area. The conference will be based at the Crest Hotel, Amsterdam, with a concurrent session on one of the days in the adjacent Novotel Hotel. Papers on the following subjects will be presented: Overview, Legislation, Envi- ronmental Databases and Environmental Au- diting, Metal Processing and Recovery, Measurement and Treatment of Effluents and Emissions, Foundries and Energy Conserva- tion.There will be several social events and a programme for accompanying persons. For a copy of the full conference pro- gramme and registration form, please contact Margaret S wadling, Conference Organizer, BNF-Fulmer, Wantage Business Park, Want- age, Oxfordshire OX12 9BJ. Biotechnology in the Clean Water Indus- tries May 22,1991, London A one day Symposium jointly organised by the SCI Environmental Biotechnology Group and the Institution of Chemical Engineers Water Subject Group will be held in 14/15 Belgrave Square. The papers given will be:52 ‘Biological Denitrification for Potable Water Treatment’, Dr. T. Hall (WRc Processes, Swindon); ‘Biological Nitrate Removal from Groundwater by S ulphur-Limes tone Deni tri- fication’, Dr.ir. J.P. van der Hoek and ir. J.W.N.M. Kappelhof (KIWA, The Nether- lands); ‘The Mechanism and Application of Fungal Biosorption to Colour Removal from Raw Waters’, Dr. C.J. Banks and Dr. M. Par- kinson (Simon Environmental Technology Centre, UMIST); ‘The Use of ELISAs for the Detection and Measurement of Pollutants in Water’, Dr. G. Wynne Aherne (University of Surrey); ‘The Use of Biosensors for Pollutant Detection in Clean Waters’, Dr. A. Wheatley (Biotechnology Centre, Cranfield Institute of Technology); ‘Biotechnology for the Remo- val of Volatile Organics from Drinking Water’ Dr. H. Chase (University of Cam- bridge); ‘Full-scale Application of Biological Methods for Removal of Organics from Groundwater-the US Experience’, (Ground- water Technology Inc.).For futher information contact the Society of Chemical Industry, 14/15 Belgrave Square, London SWlX 8PS. Environmental Protection and Man May 29-31,1991, Kyzyl, Tuva, USSR At this 3rd Republican Conference there will be the following sections: Section 1, ‘The protection of bowels of the earth, soils and landscapes,’; Section 2, ‘The state and per- spectives of development and protection of flora and fauna’; Section 3, ‘The environment and human health’; Section 4, ’The nature of water resources: physical characteristics, chemical and biological compositions and balneological characteristics’; Section 5 , ’Ecological education in universities and in the community’; Section 6, ’The preservation of cultural heritage of ethnic groups inhabit- ing Tuvinian region’; Section 7, ‘Experiment “Ubsu-Nur” (problems and perspectives)’.For futher information contact Dr. K.D. Arakchaa, Tura Complex Department, USSR Academy of Sciences, Siberian Division, 667000 Kyzyl, USSR. Chemically Modified Surfaces Symposium July 31-August 2,1991, Chadds Ford, Penn- sylvania, USA The conference will be held at the Chadds Ford Ramada Inn in Chadds Ford, PA. It will feature speakers from a variety of chemical disciplines dealing with the investigation of ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 chemically modified surfaces. Session topics will include: geometric considerations in sur- face modification, modification of polymer surfaces, chemical modification of mem- branes, surface characterisation and industrial applications of surface modification.Rooms will be available at the Chadds Ford Ramada Inn, Routes 202, and 1, Glen Mills, PA. The single and double occupancy rate will be $58.00 and $68.00 per day. Papers are solicited on the session topics outlined above. Persons interested in presen- ting a paper should submit a 200 to 250 word abstract no later than March 15, 1991. A pos- ter session will be available for papers which are not scheduled for one of the sessions. Authors will be requested to submit a camera-ready manuscript of their presenta- tion. Separate instructions will be supplied to the authors regarding manuscript preparation. Please mail abstracts and address en- quiries to: Dr. Horacio A. Mottola, Depart- ment of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA.Flow Analysis V August 21-24,1991, Kumamoto, Japan The Fifth International Conference on Flow Analysis, organised by The Japanese Associ- ation for Flow Injection Analysis, a division of The Japan Society for Analytical Chem- istry, will be held in Kumamoto. The scope of the conference will be similar to that of Flow Analysis conferences held in Amster- dam (1979), Lund (1982), Birmingham (1985) and Las Vegas (1988). Current re- search on all aspects of continuous flow ana- lysis will be covered, including: instrumentation for flow injection analysis and for continuous segmented and unseg- mented flow analysis, and approaches to total automation; new detector systems and hybrid systems; Theory of flow analysis; Applica- tions in industrial, environmental and clinical analysis.The following lecturers have been invited to speak: Professor G.D. Christian (University of Washington, USA); Professor Z. Fang (Institute of Applied Ecology, Aca- demica Sinica, China); Professor E.H. Han- sen (Technical University of Denmark, Denmark); Professor N. Ishibashi (Kyushu University, Japan); Professor G. Johanasson (University of Lund, Sweden); Professor T. Kawashima (Tsukuba University, Japan); Professor W.E. van der Linden (Twente University of Technology, The Netherlands); Professor K. Toth (Technical University, Hungary); Professor J.F. Tyson (University of Massachusetts, USA); Professor M. Valcarcel (University of Cordoba, Spain). Abstracts of papers and posters submitted for presentation must be sent to Mr.Yoshio Nishikawa, Ainek Co., Nishaharucho 3-1-5- 107, Hakataku, Fukuoka 816, Japan, before March 3 1, 199 1. Contributed papers consist of oral and poster presentations. The first choice of the mode (oral or poster) presenta- tion should be made by an author when the abstract is submitted. 1st World Congress of Cellular and Mole- cular Biology September, 1-7,1991, Paris, France This 1st World Congress of Cellular and Molecular Biology, organized by the editors of the journal Cellular and Molecular Biol- ogy will include about 40 symposia concern- ing the most promising themes in the field of cellular and molecular biology. All information concerning the full pro- gramme, the registration, the fee, the lodg- ings, the deadline for the abstracts, the full papers (on floppy disks), travel by air or train and social events will be given on request by: Mrs. Leila Orbecchi, Director CERT, 63, Av- enue Parmentier, 75 01 1, Paris, France. Clean Air at Work September 9-13,1991, Luxembourg The Commission of the European Com- munities is planning in conjunction with the Royal Society of Chemistry (UK) and in col- laboration with the UK Health and Safety Ex- ecutive, a symposium on occupational health hygiene in the context of European initia- tives. The symposium will consider the im- plications of European Directives, European standardisation, new trends in measurement methodology, and initiatives on quality assur- ance. It will have a supporting programme of poster sessions and a manufacturers’ exhibi- tion. The first circular (containing the prelimi- nary programme, the registration form, a call for posters and information for the manufac- turers’ exhibition was issued in January, 1991, can be obtained from Mr. D. Nicolay, Commission of the European Communities, Batiment Jean Monnet, Office B4/87, L-2920 Luxembourg.

ISSN:0144-557X    

DOI:10.1039/AP9912800051

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

52 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 Courses Bio-Fouling and Bio-Corrosion March 21 -22,1991, Leeds The course will be held at The University of Leeds. For further information and applica- tion forms please contact Mrs. Emma Col- lins, Department of Continuing Professional Education, Continuing Education Building, Springfield Mount, Leeds LS2 9NG. Food, Water and Environment Analysis April 9-1 2,1991, Reading The Association of Public Analysts offers a four day residential training course in the analysis and examination of food, water, and environmental materials. The course will be held at the University of Reading and is open to analysts and other scientific personnelANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 53 working in industry, trade or enforcement sectors.Topics included in the 1991 course cover practical microscopy and practical water microbiology, certificate and report writing (with particular emphasis on the new certificate specified for the Food Safety Act 1990), and lectures 011 food law in the 1990s, toxicological aspects of food, water treatment and analysis, water pollution, air quality and analysis of consumer goods. Whilst this course is of special interest to those conside- ring the Mastership in Chemical Analysis (MChemA) examination, the material will appeal to many other analysts wishing to broaden their understanding of these subjects. Further information on this course, which costs an inclusive &365 per person, may be obtained from Mr. N. Harrison, APA Training Committee Chairman, County Analyst’s La- boratory, Fillingate, Wanlip, Leicester LE7 8 PF.Control of Electrical Hazards in the Work- place April 23-25,1991t Loughhorough Now the Electricity at Work Regulations have been in force for a year employers are recognising the need to employ competent persons with a good knowledge of the regula- tions and compliance strategies. A course will be held by Tom Thompson, an inde- pendent consultant, and Edwin Hooper, for- mer Chief Safety Officer for the Electricity Council. It will inform delegates of the ha- zards of electricity in a wide variety of situ- ations and the legal requirements for electrical safety in their own workplaces. For further details please contact: Ms. Sandy Mann, Centre for Extension Studies, University of Technology, Loughborough, Leicestershire LEI 1 3TU.Safety Aspects of Laser Use May 1-2,1991, Loughhorough The University Training Group at Loughbo- rough University of Technology is organising a health and safety course entitled ‘Safety As- pects of Laser Use’. The course will be held at the University and will focus on the British Standard BS7192: 1989 which makes recom- mendations to manufacturers and users of laser products. Hazards of laser use and their control will be described and the course will include practical demonstrations and group exercises. Further details are available from Joyce Motyka, University Training Group, Univer- sity of Technology, Loughborough, Leices- tershire, LE11 3TU. Shandon Hypercarb Users Workshop May 7, I991, Manchester The fourth workshop on the Applications of Hypercarb, Shandon HPLC’s unique family of porous graphitised carbon columns, will be held at the Staff House, Conference Centre, University of Manchester Institute of Science and Technology, Sackville Street, Manches- ter.Dr. Brian Clark of the University of Bradford will give a paper on the applications of Hypercarb in stability indicating assays for drugs; while Mike Harding of Kraft General Foods, Banbury, will discuss using Hyper- carb for the analysis of instant coffee for Maillard reaction compounds. Other spea- kers will discuss their experiences using Hypercarb for similar analyses of drugs and foodstuffs. All users and potential users of Hypercarb columns will be welcome to at- tend the workshop. Enquiries should be addressed to Dr.Bul- vinder Kaur, Shandon Scientific-HPLC Di- vision (tel. 0928-56661 1). AOCS 1991 Educational Programs The Amercan Oil Chemist’s Society will sponsor four short courses which will be held immediately preceding the 1991 AOCS An- nual Meeting and Exhibition in Chicago, Illi- nois, from May 9-1 1. Two courses will be held at the Indian Lakes Resort in Bloomingdale, Illinois. One is a two-day course on ‘Environmental Con- cerns in Fats and Oils Processing’ and the other is a two-day course on ‘HPLC of Li- pids’. The remaining two courses will be held at the Oak Brooks Hotel in Oak Brook, Illi- nois. The first course, ‘Methods to Assess Oil Quality and Stability’ will run for two and a half days while the other is a two-day course on ‘Physical Chemistry of Fats and Oils with Application to Product Development.’ For more information about any of these courses contact the AOCS Education Depart- ment, P.O.Box 3489, Champaign, IL 61821, USA. Molecular Graphics and Modelling Train- ing Course June 30-July 4,1991, York This will be an intensive four-day course with ‘hands-on’ training. For details contact Mrs. Jean Scott, Short Course Secretary, De- partment of Chemistry, University of York, York YO1 5DD or Dr. David Goodall, Conti- nuing Education Officer, Department of Chemistry, University of York, York, YO1 5DD. Analytical Chemistry Short Courses Summer, 1991, Loughhorough The following Short Courses will be or- ganised by the Department of Chemistry of the University of Technology during the Summer vacation this year.Radioisotope Techniques, July 1-5, 1991; Statistics for Analytical Chemistry, July 2-5, 1991; High- Performance Liquid Chromatography, July 8-12, 199 1 ; Principles of Polymer Science, September 1-6, 1991; Electronics for the Scientist, September 9-1 1, 1991. Second para = Further details are available from Mrs. S. Maddison, Department of Chemistry, Loughborough University of Technology, Loughborough, Leicestershire LEI 1 3TU. Second European Summer School in Radi- ological Protection July 8-12,1991t Cambridge This week-long residential summer school in the attractive environment of Jesus College, Cambridge, will provide a comprehensive re- view and update of the concepts and practice of radiological protection. Recent develop- ments in the understanding and assessment of radiation effects will be discussed and the im- plications of the changes in the recommenda- tions of the International Commission on Radiological Protection will be considered.Delegates will be addressed by an experi- enced, authoritative panel, including speakers from MRC Radiobiology Unit, Health and Safety Executive, Nuclear Electric, British Nuclear Fuels, Directorate of Fisheries Re- search and Professor John Lakey. For further information please contact Liz Hide, IBC Technical Services Ltd., Bath House (3rd Floor), 56 Holborn Viaduct, Lon- don EC 1 A 2EX. Molecular Recognition: Redesigning Pro- teins as Chemical Reagents September 2 4 , 1 9 9 1 , Bristol This new intensive course covers recent de- velopments which now enable the redesign of protein structures which specifically interact with small biologically active molecules.It is aimed at chemists and biochemists in in- dustry who wish to become familiar with the possibilities these new advances offer. The course will include: Molecular Modelling; Characterisation of Proteins (e.g., X-ray and NMR); Purification and Isolation of Proteins; Redesign and Applications. The course will be a mixture of lectures, case studies, demon- strations and practical classes. It will be taught by a team of internationally recog- nised scientists from both universities and in- dustry. The course fee &890 includes accommodation, meals, conference dinner, tuition fee and course notes. The numbers for this course are restricted to 25 so early registration is advised. For details, please write to Dr. David Hill, University of Bristol, Department of Conti- nuing Education, Wills Memorial Building, Queen’s Road, Bristol, BS8 IHR. Workshop in Liquid Scintillation Counting September 9-13,1991, Loughhorough The Royal Society of Chemistry’s Radio- chemical Methods Group is organising a Workshop in Liquid Scintillation Counting. The Workshop will be held at Loughborough University of Technology. For further details or an application form please contact Dr. Peter Warwick, Nuclear Chemistry Laboratories, Loughborough University of Technology, Loughborough, Leicestershire LEI 1 3TU.

ISSN:0144-557X    

DOI:10.1039/AP9912800052

出版商:RSC    

年代:1991

数据来源: RSC

摘要:

54 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 Analytical Division Diary FEBRUARY Wednesday, 27th, 12 noon: Lancaster North West Region: Annual General Meeting; 7 p.m. Accreditation-Necessity or Nuisance. Although analytical laboratories clearly need good quality assurance procedures, do they need to go through the formality of accreditation by an outside body or is this just a bureaucratic paper chase adding little in reality to a laboratory’s performance? Even if accreditation is thought helpful, or even just expedient, what accreditation? How should we decide between BS 7570 and NAMAS? This meeting hopes to present people’s experiences of accreditation and allow ample time for discussion. What BS 5750 accreditation has to offer. What NAMAS accreditation has to offer. Experiences of those who have attempted accreditation.Round table discussion. The University, Lancaster. Registration is necessary. Cost &25 to RSC members, f45 to non-members and El0 to retired members and students. Contact: Dr. C. J. Peacock, Chemical Analysis Service, School of Physics and Materials, The University, Lancas- ter LA1 4YA. (Tel. 0524-65201, Ex. 3366). Wednesday, 27th, 6.30 p.m.: London Micro & Chemical Methods Group and South East Region. COSHH-One Year On. It is expected that the discussion will centre round the impact of COSHH regulations on working practices in the analytical laboratory. Discussion introduced by P. Wusteman. Room A506, London School of Economics, Houghton There are no registration formalities. Contact: Miss L. Dixon, Metal Box Group Technology, Denchworth Road, Wantage, Oxfordshire OX12 9BH.(Tel. 081-840-0999, Ex. 2019). Street, London WC2. Thursday and Friday, 28th and March 1st: Teddington South East Region, jointly with the South East Region of the Industrial Division and in conjunction with the Laboratory of the Government Chemist. The Chemistry of Wood Preservation. Thursday, 28th- Treatment Processes Introduction and Overview: ‘Biological Aspects, Nature of Pests and Threats’, by David J. Dickinson. ‘History, Development Uses, Advantage and Future Trends’, by Mike Connell. ‘Diffusion Treatment of Wood-An American Perspective’, by Lonnie H. Williams. ‘Diffusion Treatment (Solids)’, by William N. Beauford. Treatment Mechanisms ‘Organic Solvent Preservatives: Application and Composition’, by E.Austin Hilditch. ‘Wood/Chemical Interactions and Effect on Performance’, by Alan F. Preston and Lehong Jin. ‘Water-based Fixed Preservatives’, by David G. Anderson. ‘Strategies for the Future’, by John Butcher. Friday 1st- Reaction and Analysis ‘Creosote Treatment’, by W. D. Betts. ‘PCP and the Environment: Analysis and Residues’ (speaker from ‘Developing QC Procedures and Standards for Diffusible Preserva- ‘Tributyltin Compounds’ (speaker from Germany to be confirmed). ‘Analysis of Wood Preservatives: BS Specifications’, by Reg J. Ecology and Control ‘Biocides and Their Assessment in Wood Preservation’, by Anthony F. Bravery. ‘Progress Towards European Standards in Wood Preservation’, by Frank W. Brookes. ‘The Market for Chemical Products in the Building and Civil Engineering Industries’, by Chris R.Coggins. ‘Preservation of Ancient Timber’, by Mark Jones. Government Science Park, Queens Road, Teddington, Middlesex. Registration is necessary. Cost to RSC members f90, non-members 2135 and students and retired members f45. Contact: Mr. S. S. Langer, The Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN. (Tel. France to be confirmed). tives’, by Edward L. Docks. Order. 071-437-8656). MARCH Friday, lst, 10 a.m.: Cardiff Analytical Division: Annual General Meeting; 4.45 p.m. Gas and Headspace Vapour Analysers. The Symposium will be concerned with recent developments in the design of devices for monitoring gases and vapours in workplaces, of headspace vapour analysis-as in the control of fermenta- tion processes, and for determining gas components in the clinical and biomedical field-including food products.‘Competitive Adsorption on to Coated Surface Acoustic Wave Sensors’, by J. F. Alder. ‘Piezoelectric Devices Based on Quartz Crystals Coated with Cyclic Organic Materials Facilitate the Detection of Organic Vapours’. by G. J. Moody. ‘Use of Ion Mobility Spectrometry for the Detection and Analysis of Vapours’, by P. Watts. ‘Solid State Gas Sensors: Prospects for Selectivity’. by D. E. Williams. ‘Gas Monitoring Based on Phthalocyanines and Related Materials’, by C. L. Honeybourne. ‘Fuel Cell Sensor Design for Carbon Monoxide and Methanol Using Platinum Single Crystals’, by G. A. Attard. ‘Developments in Membrane-covered Gas Sensors for Oxygen and Other Gases in Relation to the Clinical and Biomedical Field’, by C.E. W. Hahn. ‘Use of Platinum-based Fuel Cells for Ethanol Analysis’, by W. J. Criddle. ‘Odour Detection Using Sensor Arrays’, by K. C. Persaud. School of Chemistry and Applied Chemistry, University of Wales College of Cardiff, Cardiff. Registration is necessary. Cost 545 to RSC members, &80 to non-members and El5 to student and retired members; accommodation and the Symposium Dinner are extra. Contact: Miss P. E. Hutchinson, Analytical Division, The Royal Society of Chemistry, Burlington House, Piccadilly, London W1V OBN. (Tel. 071-437-8656). [continued on p . 551ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 55 Analytical Division Diary, continued March. continued March 20th- Microelectrode and Amperometric Sensors. Biosensors.Ion Selective Electrode and Potentiometric Sensors. Practical Laboratory. Department of Chemistry, The University, West Mains Road, Edinburgh. Registration is necessary. Cost &75 for RSC members, 295 for non-members and $40 for bona fide students. Contact: Dr. H. H. Girault or Miss Rhonda Greig, Depart- ment of Chemistry, The University, West Mains Road, Edinburgh EH9 355. (Tel. 031-650-4744 or 031-650-4724; Fax 031-662-4054). Tuesday, 5th: Birmingham Midlands Region. Schools Lecture: ‘Chemical Analysis of Food’. Speaker: C. H. S. Hitchcock. The University, Birmingham. Contact: Dr. R. M. Smith, Department of Chemistry, University of Technology, Loughborough, Leicestershire LE11 3TU. (Tel. 0509-222563).Wednesday, 6th, 9.30 a.m.: Wolverhampton Midlands Region and Chemometrics Group. What Can Chemometrics Do For You? ‘Robust Statistics: What Are They and Why Are They Useful?’ by ‘Exploring Your Data and What To Do If You Don’t Know the ‘Using Statistical Tools to Design Effective Experiments’, by John ‘Looking for Patterns in Your Data and Data Simplification’, by Workshops, Poster Papers and Exhibition. Topics of parallel ‘Modelling and Data Analysis with Mathcad’, by Mike Adams. ‘Exploratory and Graphical Statistics with Stata’, by John M. ‘Using Statgraphics PC’. The Polytechnic, Wolverhampton. Registration is necessary. Cost &25 for RSC members, $35 for non-members, and f10 for students, retired or non-employed members. Contact: Dr. M. Adams, School of Applied Sciences, Wolverhampton Polytechnic, Wulfruna Street, Wolver- hampton WV1 1SB.(Tel. 0902-313001). Mike Thompson. Distribution or If It Isn’t Normal’, by John M. Thompson. Mendham. Ken Burton. workshops include: Thompson. Friday, 8th: Stevenage East Anglia Region, jointly with the Environment Group of Dioxins, PCBs and Related Compounds-An Update. Warren Spring Laboratory, Stevenage. Contact: Mr. P. R. Brawn, Unilever Research, Colworth Laboratory, Sharnbrook, Bedfordshire MK44 1LQ. (Tel. the Industrial Division. 0234-22201 1). Tuesday and Wednesday, 19th and 20th: Edinburgh Scottish Region and Electroanalytical Group, jointly with the Electroanalysis. A two day course introducing modern electrochemical methods of analysis, comprising lectures and practical experiments.The lecture course is aimed at giving a general introduction to electrochemistry and an overview of electroanalytical techniques. The laboratory course will provide access to six different types of experi- ments. The course is supported by leading instrument manufacturers to ensure that laboratory teaching is per- formed with state of the art equipment. The course is suitable for anyone working in analytical science and no particular knowledge of electrochemistry is required. March 19th- Fundamentals of Electrochemistry. Polarography and Stripping Voltammetry. Practical Laboratory. Exhibition of Equipment with Sherry Reception. University of Edinburgh. Wednesday, 20th, 10.45 a.m.: Norwich Molecular Spectroscopy Group and East Anglia Region. The Potential of Laser Excitation Spectroscopy.‘Introduction to Laser Excitation Spectroscopy’, by D. L. Andrews. ‘General Aspects of Laser Instrumentation’, by M. R. S. ‘Laser Electronic Spectroscopy of Large Molecules’, by J. M. ‘Laser-Induced Fluorescence’, by J. Pfab. ‘Multiphoton Absorption Spectroscopy’, by M. N. R. Ashfold. ‘Laser Mass Spectrometry’, by K. W. D. Ledingham. ‘Ultrafast Spectroscopy’, by G. S. Beddard. Link Suite, University of East Anglia, Nonvich. Registration is necessary. Cost 236 to RSC/MSG members, &50 to non-members and $15 to student, retired or unwaged members. Contact: Dr. D. L. Andrews, School of Chemical Sciences, University of East Anglia, Nonvich NR4 7TJ. McCoustra. Hollas . Thursday, 21st: London Joint Pharmaceutical Analysis Group : Annual General Pharmaceutical Analysis-Past, Present and Future.Royal Pharmaceutical Society of GB, 1 Lambeth High Street, London SW1. Registration is necessary. Contact: Mr. B. R. Matthews, Medicines Control Agency, Market Towers, 1 Nine Elms Lane, London SW8 5NQ. (Tel . 07 1-720-2 188, Ex. 3228). Meeting. Monday, 25th: Loughborough Particle Characterisation Group, jointly with the Aerosol Particle Shape: Its Definition and Measurement. University of Technology, Loughborough. Contact: Mr. M. K. Till, SXT, Building B9T2, AWE Aldermaston, Reading, Berkshire RG7 4PR. (Tel. 0734- 814111). Society. Thursday, 28th, 9.30 a.m.: Plymouth Atomic Spectroscopy Group and Western Region, jointly with the Atomic Spectrometry Updates Executive Com- mittee. Alternative Plasma Sources.The last two decades have seen plasmas become widely established as spectral, atom and ion sources in analytical spectroscopy. Much attention has focused on the inductively coupled plasma (ICP). However, [continued on p . 56156 ANALYTICAL PROCEEDINGS, FEBRUARY 1991, VOL 28 Analytical Division Diary, continued March, continued several alternative plasma sources, including the microwave induced plasma (MIP), direct current plasma (DCP), laser-produced plasmas and glow discharge type sources, have been developed and successfully applied in several areas. This meeting provides an international perspective on current research in this important area of atomic spec- trometry. ‘Alternative Plasma Sources: ICP and MIP Discharges’, by R . M. Barnes. ‘Sampling Strategies for a Gas-jet Enhanced Sputtering Device’, by J .R. Dean, S. J. O’Gram, M. Rae and J . Marshall. ‘An Analytical Assessment of FANES for Trace Element Determi- nation’, by D. Littlejohn. ‘Environmental Analysis by DCP’, by J . A. Armstrong. ‘ICP-The Formative Years’, by M. Thompson. ‘Laser-produced Plasmas: Research Toys or Routine Analysis ‘Sample Introduction Phenomenon Using DCP’. by B. Fairman and Polytechnic South West, Plymouth. Registration is necessary. Cost f35 for RSC members, f45 for non-members and 220 for students and retired members. Contact: Dr. S. J. Hill, Department of Environmental Sciences, Polytechnic South West, Drake Circus, Plymouth, Devon PL4 8AA. (Tel. 0752-233012). Tools?’ by J.-M. Mermet. S. Hill. APRIL Thursday, 4th: Glasgow Scottish Region, jointly with the Glasgow and West of .Scotland Section of the RSC and the Andersonian Recent Developments and Applications in Liquid Scintillation Counting. University of Strathclyde, Glasgow. Contact: Mr. E. C. Smith, ICI FMCO, Earls Road, Chemical Society. Grangemouth FK3 8XG. (Tel. 0324-494891). Monday to Friday, 8th to 12th: London RSC 150th Anniversary Congress. Analytical Division Achievements and New Directions in Analytical Chemistry: Luminescence and Optical Sensors. Tuesday, April 9th- Theophilus Redwood Lecture: ‘Impulses of Light Coming and Going Endlessly-Molecular Fluorescence and Luminescence Methods in Analytical Chemistry’, by J. N. Miller. Symposium on : Molecular Fluorescence ‘Early Studies of Luminescence: Contributions of Robert Boyle’, by D. Thorburn Burns.‘High Resolution Luminescence Spectroscopy as an Analytical Tool’, by N. H. Velthorst. ‘Enhanced Photoluminescence in Flowing Systems: From Micellar Media to Oprosensing’, by A. Sanz-Medel. Optical Sensors ‘From Fluorescent Probes to Optical Sensors’, by 0. S. Wolfbeis. ‘Bioluminescent Sensors’, by P. R. Coulet. ‘Optical Sensors’, by R. Narayanaswamy. Robert Boyle Lecture: ‘A Microscopic Abstract of Electron Transfer for Metallo-proteins and Enzymes at the Electrode-Solution Interface: Theoretical and Applied Aspects’, by A. M. Bond. Wednesday, April 10th- Atomic Fluorescence ‘Inductively Coupled Plasmas as Sources and Atomisers in Atomic ‘Laser-induced AFS’. speaker to be announced. Chemiluminescence ‘Chemiluminescence Detection in Liquid Chromatography’, by P.J. ‘Chemiluminescence and Bioluminescence in Immunoassays and Timc-resolved Lanthanide(II1) Electroluminescence and its Analy- Fluorescence Detection ‘Computer Aided Fluorescence Detection in Liquid Chromato- graphy’, by A. F. Fcll. ‘Laser Fluorimetric Detection in Capillary Electrophoresis’, by M. J. Sepaniak. Immunotechniques ‘Optical Immunoassays and Immunosensors’, by N. J. Seare. ‘Multianalyte Detection Based on Fluoroimmunoassay Devices’, by R. Ekins. Joint Divisional Reception at the Royal Institution to include an Address on ‘The Genius of Faraday’, by J. M. Thomas. A further Symposium organised jointly by the Electrochemistry Group of the Faraday Division and the Elecrroanalytical Group of the Analytical Division will also be held during the Congress, entitled: Fluorescence Spectrometry’, by S.Greenfield. Worsfold. Other Ligand-binder Assays’, by G. H. G . Thorpe. tical Feasibility’, by K. Haapakka. New Electrochemical Sensors. Tuesday, April 9th- l’heophilus Redwood Lecture. ‘Selectivity in Solid Statc Sensors’, by D. J . Williams. ‘High Temperature Electrochemical Sensors’, by W. L. Worrell. ‘Semiconductor Sensors for Workplace Monitoring’. by P. T. ‘Semiconductor Gas Sensors Revisited’, by G. S. V. Coles. ‘Surface Science Studies in Relation to Gas Sensors’, by D. Kohl. ‘Recent Advances in Applied Electrochemical Gas Sensors’, by P. J. Robert Boyle Lecture. Workshop and Poster Session. Wednesday, April 10th- ‘Nanotechnology and Sensing on the Molecular Scale’, by W. ‘New Solid State Potentiometric Sensors’, by M. Kleitz. ‘Ion Selective Electrodes’, by A. K. Covington. ‘Design and Synthesis of Artificial Receptors for Sensor Use’, by ‘Ion Selective Electrode Studies of New Organic Molecule Sensors’, ‘Control of Transport Through Lipid Membranes’. by U. J . Krull. ‘Non-Faradaic Electrochemical Sensors: Principles and Practice’, by ‘Electrochemical Sensors’, by J. Janata. Thursday, April 11th- ‘The Design of Polypyrrole Gas Sensors’, by J. M. Slater. ‘Applications of Electropolymerised Films in Electrochemical Sen- sors’, by P. N. Bartlett. ‘Enzyme Entrapment in Conducting Polymers: Applications in Ampcrometric Biosensors’. by C . R. Lowe, B. F. Yon Hin, D. C. Cullen. S. E. Evans and R . S . Sethi. ‘Enzyme Electrodes’, by H. A. 0. Hill. ‘Disposable Singlet Use Sensors’, by M. J . Green. ‘Applications of Amperometric Biosensors’, by A. P. F. Turner. ‘Progress Towards the Development of an Implantable Glucose Sensor’. by G . S. Wilson. ‘Sensors for Fermentation, Neurophysiology and Clinical Medi- cine’, by W. J. Albery. Registration is necessary. Cost f74.75 to members, .El15 to non-members and f23 to student, retired and unemployed members. Contact: Dr. J. F. Gibson, The Royal Society of Chemistry, Burlington House, Piccadilly, London WlV OBN. (Tel. Walsh. Iredale. Gopal. J. C. Lockhart. by J . D. R. Thomas. D. B. Kell. 071-437-8656).

ISSN:0144-557X    

DOI:10.1039/AP9912800054

出版商:RSC    

年代:1991

数据来源: RSC