MAY, 1958 THE ANALYST Vol. 83, No. 986 PROCEEDINGS OF THE SOCIETY FOR ANALYTICAL CHEMISTRY ANNUAL GENERAL MEETING THE eighty-fourth Annual General Meeting of the Society was held at 4.30 p.m. on Wednesday, February 26th, 1958, in the meeting room of the Royal Society, Burlington House, London, W.1. The Chair was occupied by the President, Dr. J, H. Hamence, M.Sc., F.R.I.C. The financial statement for the year ending October 31st, 1957, was presented by the Honorary Treasurer and approved, and the Auditors for 1968 were appointed. The Report of the Council for the year ending February, 1958 (see pp. 253-261), was presented by the Honorary Secretarv and adopted. had and had T h i Scrutineek, Mrs. H. I. Fisk and Mr. H. E. Brookes, reported that the following been elected officers for the coming year- President- J.H. Hamence, h1.S~. , Ph.D., F.R.1 .C. Past Presidents serving on the Council-D. W. Kent-Jones, J. R. Nicholls, George Taylor K. A. Williams. Vice-Presidents-N. I,. Allport, R. C. Chirnside and A. A. Smales. Honorary Treasurer-A. J. Amos. Honorary Secretary-R. E. Stuckey. Honorary Assistant Secretary-S. A. Price. Other Members of Council-The Scrutineers further reported that 501 valid ballot papers been received and that votes had been cast in the election of Ordinary Members of Council as follows-J. Haslam, 348; W. T. Elwell, 309; G. W. C. Milner, 308; T: S. West, 305; R. A. Chalmers, 281 ; E. I. Johnson, 247 ; P. ,J. C. Haywood, 224; H. A. Williams, 214; F. C. Hymas, 205; H. C. Smith, 199. The President declared the following to have been elected Ordinary Members of Council for the ensuing two years-R. A.Chalmers, W. T. Elwell, J. Haslam, E. I. Johnson, G. W. C Milner and T. S. West. W. Cule Davies, D. C. Garratt, H. 31. N. H. Irving, E. Q. Laws and J. G. Sherratt, having been elected members of the Council in 1957, will, by the Society’s Articles of Associa- tion, remain members of the Council for 1958. A. N. Leather (Chairman of the North of England Section), Magnus A. Pyke (Chairman of the Scottish Section), S. Dixon (Chairman of the Western Section), R. Belcher (Chairman of the Midlands Section), D. F. Phillips (Chairman of the Microchemistry Group), R. A. C. Isbell (Chairman of the Physical Methods Group) and S. K. Kon (Chairman of the Biological Group) will be ex-oficio members of the Council for 1958.After the business outlined above had been completed, the meeting was opened to visitors, and Sir Hugh Linstead, O.B.E., LL.D., F.P.S., M.P., delivered the Bernard Dyer Memorial Lecture (see pp. 275-283). At the close of the meeting the President presented Sir Hugh with the Bernard Dyer Memorial Medal. JOINT MEETING A JOINT Meeting of the Society and the Southern Region of the Association of Clinical Biochemists was held at 7 p.m. on Wednesday, May 7th, 1958, in the meeting room of the Chemical Society, Burlington House, London, W.1. The Chair was taken by the President of the Society, Dr. J. H. Hamence, MSc., F.R.I.C., who was introduced by Mr. C. F. M. Rose, A.R.I.C., Chairman of the Southern Region of the Association of Clinical Biochemists.The subject of the meeting was “Electrophoresis in Clinical Biochemistry” and the following papers were presented and discussed : “Basic Principles and Main Requirements 2492 50 PROCEEDINGS [Vol. 83 for Satisfactory Electrophoresis,” by Professor Nicholas H. Martin, M.A., B.Sc., B.M., M.R.C.P., F.R.I.C. ; “Paper Electrophoresis of Lipoproteins,” by W. G. Dangerfield, Ph.D. M.R.C.S. , L.R.C.P. ; “The Clinical Applicakion of Electrophoresis,” by A. L. Latner, M.D., M.Sc., M.R.C.P., F.R.I.C. NEW MEMBERS ORDINARY MEMBER Michael George Ashley, F.R.I.C., F.P.S. JUNIOR MEMBERS Philip S. Chen, jun., B.A. (Clark), Ph.D. (Rochester) ; James Murphy; Alan George Sinclair, B.Sc. (Aber.). DEATH William Macro Seaber. WE record with regret the death of NORTH OF ENGLAND SECTION A JOINT Meeting of the Section and the Tees-side Local Section of the Royal Institute of Chemistry was held at 8 p.m.on Friday, March 28th, 1958, at the William Newton School, Junction Road, Stockton-on-Tees. The #Chair was taken by the Chairman of the North of England Section, Mr. A. N. Leather, B.Sc., F.R.I.C., at the invitation of Mr. H. N. Wilson, F.R.I.C., Chairman of the Tees-side Local Section. The following paper was presented and discussed : “Residues in Foods Deriving from Processing Hygiene and Manufacturing Aids,” by J. B. M. Coppock, B.Sc., Ph.D., F.R.I.C., and R. A. Knight, B.Sc., F.R.I.C. SCOTTISH SECTION AN Ordinary Meeting of the Section was held at 6.50 p.m. on Monday, March 24th, 1958, in the Royal College of Science and Technology, 204 George Street, Glasgow, C.l.The Chair was taken by the Chairman of the !Section, Dr. Magnus Pyke, F.R.I.C., F.R.S.E. Following an introductory talk by him, a film on “Polarography” was shown by Dr. J. Masek of the Czechoslovak Polarographic Research Institute, Prague. WESTERN SECTION THE Section participated in a meeting of the South-Western Counties Section of the Royal Institute of Chemistry held at 5.30 p.m. on Friday, February 21st, 1958, in the Technical College, Plymouth. The Chair was taken by the Vice-chairman of the South-Western Counties Section, Mr. T. W. Parker, F.R.I.C. A lecture on “New Techniques in Qualitative Analysis” was given by D. W. Wilson, M.Sc., F.R.I.C. MIDLANDS SECTION AN Ordinary Meeting of the Section was held at 6.30 p.m.on Thursday, March 20th, 1958, in the Mason Theatre, The University, Edmund Street, Birmingham, 3. The Chair was taken by the Chairman of the Section, Ilr. R. Belcher, F.R.I.C., F.1nst.F. A discussion on “The Determination of Toxic Substances in the Atmosphere” was opened by J. C. Gage, B.Sc., Ph.D., F.R.I.C. MICROCH EMISTRY GROUP THE fourteenth London Discussion Meeting of the Group was held at 6.30 p.m. on Wednesday, March 19th, 1958, in the restaurant room of “The Feathers,’’ Tudor Street, London, E.C.4. The Chair was taken by the Honorary Secretary of the Group, Mr. D. W. Wilson, M.Sc., F.R.I.C. A discussion on “The Microdetermination of Carbon, Hydrogen and Nitrogen in the Presence of Interfering Elements” was opened by G. Ingram, A.R.I.C.May, 19581 PROCEEDINGS 251 BIOLOGICAL METHODS GROUP A DEMONSTRATION Meeting of the Group was held at 6.30 p.m.on Wednesday, March 26th, 1958, in the Physiology Laboratory, University College, Gower Street, London, W.C.l. The Chair was taken by the Chairman of the Group, Dr. S. K. Kon, F.R.I.C. Apparatus and techniques used in plate assays- Joy Stephens and Pat Whitmore. (a) Semi-automatic plate punching machine ; (b) large-plate levelling screws ; (c) a nomogram for 2 : 1 and 4 : 1 dose-ratio plate assays (3Iiyamura)- J. S. Simpson. Automatic press-button filling machine delivering 1 to 5 ml-P. L. Gibbon. Device for speeding up turbidity readings using a Spekker absorptiometer-P. L. Gibbon. Apparatus for photographing plates-D. Lawson. Comparison of agar gel for assay media-W.H. Pierce. Membrane filtration-W. H. Pierce. The use of large plates in routine bacteriological methods-A. H. Sexton. The assay of choline by disc plate-E. C. Barton-Wright. The assay of diastase by large-plate methods-R. E. Duncombe. The assay of synergistin components of the antibiotic El29 complex-Christine J. Bessell. Estimation of the activity of drugs against Leishmania donovani-Kathleen R. Heath and Jean Fisher. Microbiological assay of mercury compounds-R. E. Duncombe. Microbiological assay of mixtures of streptomycin and dihydrostreptomycin- J. P. Jefferies and The standardisation of freeze-dried B.C.G. vaccine-Pauline Farmer, J. Dudley and P. W. Muggleton. Vitamin B,, antagonists-W. F. J. Cuthbertson and H. F. Pegler. Automatically controlled isolated-organ bath- J.L. Mongar. Automatic apparatus for controlling infusions during digitalis assays-L. Hall and K. L. Smith. Antidiuretic assay-S. E. Dicker. Assessment of anti-inflammatory drugs-G . F. Somers. Simple methods for testing analgesic drugs--(;. F. Somers. Automatic scanner of labelled chromatograms-F. P. W. Winteringham. The following pieces of apparatus were demonstrated- J. S. Simpson. SUMMARIES OF PAPERS PRESENTED AT MEETINGS OF THE SoCrErY ’I‘m following are summaries of the papers presented at the Ordinary Meeting of the Society organised by the Microchemistry Group on Friday, February 7th, 1958, in London. A first report appeared in The Analyst, 1958, 83, 65. The papers were: “Applications of the Conway Diffusion Technique to the Analysis of Radioactive Materials for Trace Impurities,” by J.K. Foreman, B.Sc., A.R.I.C. ; “The Use of Long-chain Quaternary Amine Salts in the Solvent Extraction of Metal Ions,” by R. Powell, A.R.I.C. APPLICATIONS OF THE CONWAY DIFFUSION TECHNIQUE TO THE ANALYSIS OF RADIOACTIVE MATERIALS FOR TRACE IMPURITIES MR. J. K. FOREMAN described work carried out in the U.K.A.E.A. laboratories at Windscale utilising the Conway diffusion technique for determining trace amounts of certain non-metallic elements in plutonium. This technique, in which the trace element was liberated as a volatile compound, had a number of features that favoured its use for the analysis of radioactive materials. In particular, (i) the diffusion units were compact, and a number of analyses could be performed simultaneously in a small glove box, (ii) the diffusion unit was a closed system and the spread of radioactive contamination was effectively localised, (iii) little operator attention was required and (iv) the effect of variables associated with a particular analysis could be readily and quickly established by experiment, and could usually be supported by simple theoretical considerations of the dependence of the rate of absorption of the volatile compound upon the dimensions of the apparatus and the volume of solution from which it was liberated.The absorption time could be reduced to a minimum by forming the volatile compound in the minimum volume of solution and by using high concentrations of ionic components to “salt-out” the volatile compound. Specific applications described were the determinations of chemically combined nitrogen, chlorine and sulphur in plutonium.Nitrogen was liberated as ammonia from the outer compartment of the Conway unit by 6 N sodium hydroxide after dissolution of the metal in hydrochloric acid. The252 PROCEEDINGS [Vol. 83 ammonia was collected in hydrochloric acid in the inner compartment, and the deter- mination was initially completed absorptiometrically by using the blue colour formed on the addition of sodium phenate, sodium hypochlorite and a trace of a manganous salt. This method was time-consuming, and in addition the sodium phenate was un- stable; therefore an alternative finish, b;sed on the titration of the excess of acid remhining after absorption of the ammonia, was substituted.Sulphuric acid, 0-01 N , incorporating the indicator (methyl red), was used as absorbent, and 0.01 hi sodium hydroxide as the titrant. The precipitate of plutonium hydroxide formed at the ammonia-liberation stage was shown not to occlude ammonia. The preparation of pure plutonium nitride (Brown, F., Ockenden, H. M., and Welch, G. A., J . Chem. SOC., 1955,4196) has permitted a rigid evaluation of the method. For the determination of chlorinle the plutonium was dissolved in 5 N sulphuric acid and the chlorine liberated by addition of a sulphuric acid - potassium permanganate oxidising mixture (which must be prepared in a bath of solid carbon dioxide to minimise its chlorine blank). After absorption in sodium hydroxide and conversion of hypo- chlorite to chloride, the latter was determined potentiometrically with silver nitrate, using a silver - silver amalgam electrode pair.This titration, at the microgram level, worked most satisfactorily in small volumes; 0.5 ml could be conveniently titrated in a platinum fluorimeter capsule, a change in potential of 40 to 50 mV occurring at the end-point. The hydrogen sulphide liberated on dissolution of the metal in hydrochloric acid was absorbed in filter- paper impregnated with lead acetate solution. The brown stain formed was compared with stains produced by known amounts of sulphur. For sulphur, a simple visual-comparison method was devised. THE USE OF LONG-CHAIN QUATERNARY AMMONIUM SALTS I N THE SOLVENT EXTRACTION OF METAL IONS MR. R. POWELL said that, in recent years, use had been made of the long-chain amines and quaternary amines for the solvent extraction of certain anionic species, e g ., the acid salts of many metals. Moore and his co-workers at ORNL had been particularly active in this field and had drawn attention to the similarity existing between this type of solvent extraction and separations with anion-exchange resins. The positively charged cations, NR,+, combined with the negatively charged anions, q., MnO,- or FeC1,3-, the resulting neutral com- pound being soluble in inert solvents !such as benzene or chloroform. By suitable choice of acid medium many useful separations could be effected. The principle had been applied to1 the separation and determination of plutonium in solutions of neutron-irradiated uranium.Normally such solutions contained a large excess of uranium and were highly radioactive. Operations had to be conducted behind shielding and the determination presented a difficult problem for the analyst. I t was possible to determine the plutonium by counting the alpha particles emitted, but correc- tions had to be applied for other alpha emitters present, and it was necessary to know the isotopic composition of the plutonium before the count could be converted into a weight of metal. A more specific non-radiclmetric method was therefore sought. Quadrivalent plutonium in nitric acid of concentrations greater than 7 M formed the acid complex Pu(NO,),"-. This could be retained on anion-exchange resins to separate it from uranium and most of the fission products, which do not form nitrate complexes in 7 M nitric acid.Recovery of the plutonium, however, was not quantitative. It could also be extracted into a number of solvents such as ethers, ketones and alkyl phosphates. Such extractions were not sufficiently selective for analytical application. The long-chain quaternary ammonium salts were then examined for this purpose and were found to be extremely useful. The compounds were not available as pure reagents, but a variety was available in the form of industrial detergents. The nitrates of these compounds were insoluble in water, but were highly soluble in benzene or chloroform. A I per cent. solution of the nitrate in benzene or chloroform was shaken with a nitric acid solution of quadrivalent plutonium. The plutonium was usually transferred quantitatively to the organic layer. The principle involved was simple.May, 19581 PROCEEDINGS 253 The most successful compound tested was Hyamine 1622, a Rohm and Haas product, st at ed to be P-diisobut ylphenoxyet hox yet h yldime t h ylbenzylammonium chloride- c1- /\ / \ CH, CR, The partition coefficient for plutoniumIV from 5 M nitric acid into benzene containing 1 per cent. of the nitrate was 200, the corresponding figure for uranium being 0.05. The beta-gamma activity of the extract showed a decrease of more than lo4, permitting the extract to be handled without heavy shielding, Because of the very selective nature of the extraction it was possible to complete the determination by a less selective, though simple, colorimetric procedure. Thoronol [the sodium salt of 1 -(o-arsonophenylazo)-2-naphthol-3 : 6-disulphonic acid] was a useful reagent for many quadrivalent metals. I t was water soluble, but the acid could be ex- tracted into benzene in the presence of a long-chain amine such as Hyamine 1622. The solution of plutonium in benzene was therefore combined with a solution of thoroiiol in the same solvent, in the presence of alcohol, and the resulting colour was measured on a Spekker absorptiometer. The limit of detection was about 1 pg of plutonium.