ISSN:0003-2654    

DOI:10.1039/AN95883FX017

出版商:RSC    

年代:1958

数据来源: RSC

ISSN:0003-2654    

DOI:10.1039/AN95883BX019

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

... THE ANALYST 111Hupkin and Williams Ltd.have been noted, for many ‘years,for theirrangeofOrpic ‘,Reagen~ for the detection ordetermination of metals, andthe Company is publishing, La series of MOW (’,p p h r dating to these rc-agents.0The fillowing illonogrophr are walloblejre on reqms:-NO. 29 GTHORIN’-Reagent fur Thorium.NO. 30 GDITHIZONE’-Reagent for LeadNO. 31 <22’-DIQUINOLYL’-Reagent for Coppcr.NO. 32NO. 33cDITHIZONE’-Reagent for Mercury, Zinc, Cadmium and 8ismuth.‘NITROSO-R-SALT’-Reag~”t for Cobalt and Iron.I’I.C\IOU~ Monographs in the series have already been issued in collective form, under thctitle “Organic Reagents for Metals, and Other Reagent Monographs”, Volume I . Copies ofthis publication are still available at I q/- nett, post free.and full details will be sent on request.HOPKIN & WILLIAMS LimitedC H A D W E L L H E A T H . E S S E X . E N G L A N DBranches in LONDON ’ MANCHESTER ’ GLASCOW Agenb throughout the U.K. and all o w the Worldiv THE ANALYSTEl!iAlii .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... ..........Now available: Vitamin FreeCasein HydrolysateThe above is added to our range,which includes :m Bacteriological Peptone m -tone m Acid Hydrolysed Casein m Bacteriological Gelatin m Corn Meal Extract m soya Peptone m Potato ExtractBacteriological Yeast ExtractDetails on request tram Division of OX0 Ltd.Thames House, London, EMCentral 9781.................... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .................... .........THE ANALYSTB.T.L. Sintered Glasswarefor filtrationB.T.L. Sintered Glassware is resistant to all reagents excepthydrofluoric acid and strong alkalis. Grades from pore Sizes 00 to 4give a complete range from rough filtration of coarse precipitatesto the “bright” filtration of the finest precipitates such as barium sulphate.Grade 5 filters, specially made and conforming to B.S. 1752-1952,are increasingly replacing ceramic filters for bacteriological work.B.T.L.Sintered Glass Filters are being used by Glaxo Laharatories Ltd.,in the manufacture of poliomyelitis vaccine and influenza virus vaccine.A full list of the range will be sent on request.V complete laboratory serviceW e are exhibiting at ACHEMA 58-STAND D3. HALL 6BAIRD 81 TATLOCK (LONDON) LTD., CHADWELL HEATH, ESSEX, ENGLANDBranches in London. Manehesrer ond Glassow. Ageirls throughour U.K. and 011 over !he world.T*s;BT.zvi THE ANALYSTL a b o r a t o ry apparatusJMC platinum apparatus and electrodes for chemicaland electrochemical analysis are available as standardor special designs for every application. Behindtheir production lie both sound theoreticalconsiderations and wide practical experience of theemployment of platinum apparatus and of users’requirements.Johnson MattheyJOHNSON, MATTHEY & CO..LIMITED, HATTON GARDEN, LONDON, E.C.lTelephone: Holborn 6989. Vimria Street. Birminghom. 1. Telephone: Centml 800.175-79 Eyre Street. Shcffield, I . Telephone: 2921THE ANALYST viiBariumCacsiumCalciumCopperIronLithiumMagnesiumMa"ga"eSePotassiumStrontiumAn important advancein flame photometry553.6 10.0852. I 2.0422.7 0.2324.8 I .o385.9 2.0670.8 0.02285.2 I .o403.3 0.2768.0 0. I460.7 0. I -UNICAMSP. 900SPECTROPHOTOMETERPOWERFULCorrect optical design provides accurate wavelength selectionover the range 250-1020 m p The high light-gathering power ofthe silica prism monochromator coupled with sensitive detectorsand a powerid amplitier give the SP.900 great poleniialiiies asa research tool and exlmml the ran@ of ilq applixtionc nn theroutine laboralow.The table shows the limits ofdetectability of various elementsin normal operating conditions.These results were obtained fromroutine production tests and donot necessarily indicate the ulti-mate performance of which theSP.900 iscapable. The results offurther tests will be published asthey become available.Theservices ofthe Unicam Appli-cations Laboratory are freelyavailable to investigate the suit-ability of the SP.900 to anyanalytical problem.A fully descriptive leaflet willgladly be sent on request.Local demonstrations are nowbeingarrangcd.Pleaselet usknowif you would like to have details.UNICAM INSTRUMENTSFAST.A sensitive direct reading galvanometer, operation on smallsample volumes, rapid setting-up p r o c e d u r d l are importanttime-saving features. The Flame Spectrophotometer is easilyconverted to a recording instrument with automatic wave-length scan.CONVENIENTCompact layout, logical disposition of controls, simple andquick-to-clean sampling system-these are some of the featuresthat distinguish the SP. 900 as a simple, convenient all-mainsinstrument, well-suited to the unskilled operatorviii THE ANALYSTThe potentialities of“Quickfit” Spherical GroundGlass JointsSpherical joints give you flexibility.They can always be separated readily.In conjunction with conical jointsthey discount rigidity incertain assemblies.Being groundto a peak standard of perfection they canbe used under the same conditionsto give the same high efficiencyof result as “Quickfit” Conical Joints.All particulars on request... - -Ib00 - ..05. nk a5TELEP Stone481H0NTHE ANALYST ixScveral hundred isoropically labelled compounds are now produced iegularly athmcrsham. They include an unrivalled range of materials needed for tracer worktn biology. pharmacology. medical diagnosis and therapy, and in many technicalapplicarinnsofchcmicalproducts-pesticides,u.eedkillers, hormoncr.andthc1ike.Most of there substances can be supplied from stock-or in rhc case ofshorr-lived sotoper, at rcasonablc notice--and their spccific activity and chemicilpurity are generally the highest available today.Somc exampler from our current production are:Compounds of Thmpentone-Sji, sodium saltPharmacologicalInterest: Cyrteamine-S j 1Sulphanilamidr, and other sulphonamides-Sj I6~Mercaptopurine~S jPhenoth;&e-SjDi-iiopropyl Ruorophosphonate-Pj 2TcrraiodnohenolDhthalcinI I 2 I4-lodoantfpyrine:In 5 1lodinarrd oils and fats-h j Ihlcrsalyl-HgmjSodium rtibogluconarc-Sbi ':1,,Agents: Sodium di-iroamyl rulphoruccinate-Sj $Sodium lavioylmcrhyltauridc-SjSodium lauryl sulphaie-SjiSurface-active Potassium ethvl xanthare-SIX THE ANALYST 4 ExternaladjustmentsLMicrobalance sensitivity and poise adjustments are mademuch easier by means of the new aluminium wing-nuts,operated ~xrerna/(v.This means that micro-balances can be keptat optimum performance quickly and simply.A detail, perhapsbut it is the sum of details like thisthat makes Oertling the choice of so many chemists.Plus, of course, the unique, nation-wide “after-sales” service forinspection, maintenance and repair by works-trained craftsmen.Write for full information to: L. Oertling, Ltd., St. Mary Cray,Kent, or ring Orpington 25771.b e t t e r weighing THE ANALYST xiPye for Chemical Instruments mPye scientific instruments are craftsman built,designed to meet the needs of research and industry;they are made to exacting standards giving utmostprecision and reliability.Our range of instrumentation covers electronicinstruments, electrical test gear, potentiometers,measuring microscopes, resistance bridges, chemicalinstruments-pH meters, conductivity meters-in fact,240 Merent items are listed in our main catalogue.Why not write for OUT latest edition: we shall be verypleased to assist you in your requirements andinstrument problems.GAS LIQUID CHROMATOGRAPHYEQUIPMENTCmdogue Number I1880A completely new instrument has been developedwhich is capable of high resolution and extremesensitivity.By means of the low noise Pye d.camplifier, connected between the katharometer bridgeand the recorder, the overall sensitivity of the systemis improved by as much as forty times. nUnder favourable conditions one microgram of a component in one millilitre ofcarrier gas gives full scale deflection.Switches are provided to change the sensitivity during a run by factors of 2,5 and 10over a wide range to a maximum sensitivity of 12.5 microvolts full scale on thepotentiometric recorder.Good temperature and pressure control ensures stability atsuch high sensitivity.In the range 50-250°C the katharometer temperature is controlled to within 0.05”C andthe column within 0.5”C. By a simple switching arrangement the temperature of eitherthe column or the katharometer may be indicated on the recorder in two ranges 50-150°Cor 150-250°C.AUTOMATIC TITRATIONEQUIPMENTThe Pye Automatic Titrator has beendesigned to combine wirh a variety of pH,millivolt and conductivity measuring insuu-ments for quick and accurate routinetitrations. This equipment will operate awide range of reagent adding devices andgive accurate control of dosing. Titrationreproducibility 1 drop.The illustration shows the AutomaticTitrator being used in conjunction wirhthe latest Pye pH meter/miUivoltmeter-the “Master”.W. G. PYE & CO., LTD.,GRANTA WORKS, NEWMARKET ROAD, CAMBRIDGE.Telephone: Combridge 54411. Telumrns: We. Cornbridlexii THE ANALYSTthe outstanding purities ofPOTASSIUM NITRATE A.R.KNOT no1 w, 101 I 1~ ~ ~~~ACTUAL BATCH ANALYSIS(Not merely maximum impurity valuer)Batch No 75401n!OChlmdc (CO Ow050.envy Metals (Pb) Ow02""dale (10,) No reactionIron (Fe) OM)O06°.Nitrite (NO,) No reacmnReaction (10"" solumn) p H 7 0Phosphate (PO.) O w o 4 , "This is the analysis of aJudactan reagent. And, as withevery other reagent in the seriesit is the actual batch analysis-it is one of several of whichwe are especially proud.1t

ISSN:0003-2654    

DOI:10.1039/AN95883FP073

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

...THE ANALYST XlllSPECTROSCOPISTPI’LICATIOSS are invited for the newly created postSpectroscopist in the Analytical Division of the ResearchOrganisation for Smith & liephew Associated CompaniesLtd. The Group manufactures surgical dressings, adhesivebandages, industrial adhesive tapes, plastic films and cosmetic,toilet and ethical pharmaceutical preparations. The workwhich is progressive in character will include the applicationof infra-red and ultra-violet spectroscopy to the investiga-tion of problems connected with the Company’s researchand development programme. Minimum qualifications area second class Honours degree in chemistry or GraduateMembership of the Royal Institute of Chemistry. Previousexperience is not essential as the necessary training will hegiven but an enthusiastic approach to the subject is important.Salary will he according to age and qualifications, hut theCompany’s main interest will he in those applications frompersons under 30 years of age.Write, giving full detailsof qualifications, experience and salary required to: TechnicalSecretary, Smith & Nephew Research Ltd., Hunsdon Labora-tories, Ware, Herts.D.S.1.R. National Physical Laboratory, Teddington,Middlesex. reouires a I’hvsicist or Metallurrist with rooddegree and p;efe;ably soin; research experience in g-raycrystallography or solid state physics. Salaries: ScientificOfficer CG35-{1,110; Senior Scientific Officer ~l,lYO-~l,410.Women-slightly less. Forms from M.L.X.S., Technical andScientific Register (I<), 26 King Street, London, S.W.l,quoting F.2G1;XA.CHEMIST is required, mainly for special work in theALahoratories of a London Brewery, A University degreeor the equivalent qualification of the Royal Institute ofChemistry is necessary, together with good experience infoodstuffs or beverages. The man appointed would herequired in the first place to gain a knowledge of the pro-cedures in the Control Laboratories of the Conipany.Agepreferably about 30. The initial salary will be in keepingwith qualifications and experience, and a non-contributorypension scheme is in operation. Applications should givefull details and he addressed to Chief Chemist, Box No. 3965,The Analyst, 4 7 Gresham Street, London, E.C.2.Closing date 28th May, 1Y58.UALITY COXTROL CHEMIST.Beechani Foodsmints, Morton Garden Peas, etc., require a Chemist in theirCentral Quality Control Laboratory to work on the main-tenance of quality standards, new specifications and newniethods for their range of products. Applicants must hequalified chemists (B.Sc./A.R.I.C.), aged 27-35 years, withindustrial experience preferably in food analysis. This is asenior appointment carrying non-contributory pension, freelife insurance and profit participation. Applications, quotingreference C.C., should he addressed to the Personnel Manager,Beecharn Foods Limited, Beechani House, Great West Road,Brentford, Middx.EXPFRIENCED CHEMIST required for, analytical andtesting work connected with problems In printing andpacking industries.Salary on scale Ll,l50-L1,600 accordingto qualifications and experience. Please quote PR/A.Graduate Physicist or prospective 1958 Graduate for researchon interaction of a porous material (paper] and a solid/liquidsystem (ink). Experience of fluid flow advantageous, hutprincipal qualification is genuine interest in frindamentalscience. Salary on scale LG50-L1,150 according to qualifica-tions and experience. Please quote PR/PR. Both appoint-ments F.S.S.U. Five-day week. Application forms fromSecretary, PATRA, Randalls Road, Leatherhead, Surrey.EPUTY CHIEF ANALYST required by well knownDcommercial organisation with Laboratories in NorthLondon. ‘She problems are concerned mainly with food andpharmaceuticals hut also cover a wide range of other pro-ducts.The prospects are good and there is a non-contributorypension scheme. Write giving age, qualifications anddetails of experience to Box No. 3966, The Analyst,47 Gresham Street, London, E.C.2.Q . Limited, manufacturers of Lucozade, Iiihena, Murray-LOUGHBOROUGH COLLEGE OF TECHNOLOGYResidential (One-week) Course in Practical Radiochemistry.The above Course will be held this year from July 14th toJuly 19th. Further particulars may he obtained on appli-cation to the Registrar, Loughhorough College of Technology.Leicestershire.GJ.AXO LABORATORIES LTD.have vacancies for TECHNICIANS in theAnalytiral Laboratory of their factory atUlverston in the Lake District.The work entails the application of generalanalytical techniques to antibiotics and finechemicals.Candidates must have had comparableexperience preferably in the pharniaceuticalor chemical industry and will be expected tohave attained H.N.C.standard in chemistryor Inter. BSc. exemption.A starting salary in the range of €623-E700 per annnni is visualised. There areliberal conditions of employment, includinga pension scheme and the opportunity toshare in the profitability of the Company.Assistance to obtain housing will he given toapplicants who are married and have children.Applications should he addressed to:The Personnel Officer,Glaxo Laboratories Ltd.,Ulverston, Lancashire.CHEMISTrequired by English Electric,Accrington, Lancashire forthe analysis of steel, non-ferrous and ceramic materials.Candidates should be ofdegree or A.R.I.C.standardwith about two years’ experi-ence in this type of work.A rented house would beavailable if required.Please write with full detailsto Dept. C.P.S., 336/7, Strand,W.C.2, quoting Ref. A 114D.HEFFER’S OF CAMBRIDGEpublish from time to time catalogues andlists of books on various subiects, andannouncements of individual new booksof special importance. Let us add yourname t o our mailing list.W. HEFFER & SONS LIMITED3 & 4 PETTY CURY. CAMBRIDGxiv THE ANALYSTANALYTICAL CHEMISTI.P. Cheniicals Ltd.. Oldburv have a vacancy for anB.Analytical Rrsearch Chemist to take charge of a labara-tory engaged on the investigation af analytical problemsassociated with the Plastics Industry with particular referenceto thermosetting resins.The work will involve the use ofmodem techniques including spectroscopy and gas-chroina-tography together with the investigation of new methods ofanalysis. A.R.I.C. or equivalent qnalification is eisential andprevious industrial experience is desirable. Preferred age30-35 years. The conipanv offers good conditions of einploy-nient and a generous Peniion and Life Insurance Scheme.Applications giving full details should be made in writing to:Personnel Manager, B.I.P. Chemicals Ltd.,Oldbury, Birminghain.CONSULTING CHEMISTSOF INTERNATIONAL REPCTErequir?UALIFIED ANALYSTS for their laboratories in Lon-Qdon. Hons. H S ~ . Cheni. or A.R.I.C. essential. Exper-ience in analysis of drugs, pharmaceutical products or finechemicals desirable. Corninrncing salary f i a o - ~ 9 0 0 perannuin. Hours 9-5.30, five-day week. Wzte giving fulldrtails of cducation qualifications cxpcrirncv and age toBOX NO. 3967 The'Anaiyst, 47 drcsnam Street, London,E.C.2.H E F F E R ' SOF CAMBRIDGEare always glad t o buySCI E NTI FICJOURNALSespecially complete sets andruns ofTHE ANALYSTalso scientific and technicallibraries, early books, bookson the history of science,etc.W. HEFFER & SONSLimitedPetty Cury, CambridgeEnglandPROCEEDINGSOF THECONGRESS ONMODERNANALYTICALCHEMISTRYIN INDUSTRYheld atThe University of St. AndrewsJune 24th'to June 28th. 1957organised byThe Scottish Section ofThe Society of AnalyticalChemistry ---244 pp, cloth.$2 2s net2-c-Published byHEFFER - CAMBRIDG

ISSN:0003-2654    

DOI:10.1039/AN95883BP083

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

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.

ISSN:0003-2654    

DOI:10.1039/AN9588300249

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

May, 19581 PROCEEDINGS 253 Annual Report of the Council: February, 1958 THE past year has been one of progress, and of consolidation for the many activities of the Society. This concentration of the Society’s activities at 14 Belgrave Square has been most beneficial, and the Council wishes to record its thanks to the Society of Chemical Industry for the help that it has given. It is a pleasure to record the increasing activities of the Sections and Groups of the Society. The Conference of Honorary Secretaries has become an annual event and is of particular importance in arranging joint meetings between Groups and Sections. During the past year no fewer than six such joint meetings have been held, at Birmingham, Exeter, Cheltenham and Newport, as well as meetings in London. Two other meetings are worthy of comment, one held in March, 1957, jointly with the Fine Chemicals Group of the Society of Chemical Industry, the other in November, 1957, when Dr.Plibil visited this country from Prague and addressed an audience of over 300 at the Royal Institution. The report of the Scottish Section, given under a separate heading, contains a detailed account of the St. Andrews Congress held in June, 1957, but it is appropriate to refer to it here. There were nearly 300 registrations, including 30 from overseas, and many applications had to be refused owing to over-subscription. The Congress was particularly successful and its organisation was an outstanding achievement on the part of the Scottish Section. The Congress Proceedings will shortly be published.All concerned are to be congratulated. The Midlands Section has also continued its many activities during the past year. It has, jn addition, been extremely active, together with the Microchemistry Group, in its preparations for the Symposiuin on Microchemistry to be held in Birmingham in August, 1958. The patronage of the International Union of Pure and Applied Chemistry has been granted to this Symposium and the Council wishes it every success. The activities of the Analytical Methods Committee are summarised separately, but it can be recorded that substantial progress has been made during the year. In particulu the work of the Trade Effluents Joint Committee has been completed and it is intended that the It has also seen the completion of the first full year in the new headquarters.254 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 [Vol.83 final booklet will be published in the Spring. The rapid progress achieved in this field is especially commendable. The Committee is fortunate in having Mr. Justice Lloyd- Jacob as Chairman of the Analytical Methods Trust, and it owes much to his direction of its financial affairs and to his lively interest in the progress of work. A successful three-year trial period has been completed-an achievement that would not have been possible without the very generous help during this period from the many subscribers to the Trust Fund. Its future work will, however, depend on an assured income and, in order to secure this, the Trustees are to appeal to Industry for the continuation of the subscriptions to the Trust Fund.Once again the Chemical Council has made a substantial grant towards the cost of publication of the Society’s journals. It is hoped in the future that the Society will be able to meet its own expenses of publication, but in the meantime it is with considerable gratitude that this grant is acknowledged. Council records with pleasure the award of the O.B.E. to Mr. B. A. Ellis, Mr. A. Glover and Mr. R. S. Haskew. During the year the Meldola Medal of the Royal Institute of Chemistry was awarded to Dr. T. S. West. Dr. R. Belcher has been elected Chairman of the Analytical Section of the International Union of Pure and Applied Chemistry. Dr. K. A. Williams was appointed as one of the British Delegates to the Paris Conference of the International Union.The Society now has 1900 members, an increase of 30 over the membership of a year ago. It is notable that this advance has occurred in spite of the recent increase in the annual subscription. The number of applications for membership continues to increase ; during the year 1957, 122 new applicants were admitted to membership as compared with 117 and 108 for 1956 and 1955, respectively. LONG MEMBERSHIP-The congratulations and good wishes of the Council are extended t o S. Dixon and F. W. Edwards, who have completed 40 years of membership. DEATI-Is-The Council regrets to have to record the deaths of the following members- K. L. Barnard L. H. Lampitt F. Pugh Lord Clinton (Honorary Member) H. Lee J. W. Skirvin A. P. Davson A. J.C. Lickorish W. B. Walker J. Gray G. Roche Lynch W. H. Woodcock A. Harvey A. E. Parkes D. A. Yoxall S. G. Kendrick ORDINARY MEETINGS-Six ordinary rrteetings of the Society were held during the year and the following papers were read and discussed- April, 1957, in London, organised by the Physical Methods Group, on Fluorimetry: “The Spectrometry of Fluorescence.” “Some Experiments with Spectrofluorimeters and Filter Fluorimeters.” “Spectrofluorimetry.” “A Direct-reading Fluorimeter.” By E. J. Bowen, M.,4., DSc., F.R.S. By C. A. Parker, BSc., Ph.D., F.R.I.C. By Professor R. T. Williams, DSc., P1i.D. By L. 13realey, BSc., and R. E. Ross, A.M.Brit.1.K.E. May, 1957, in London, organised by the Biological Methods Group, on the Estimation of Antibiotic Residues in Food: “Antibiotics and the Public Health.” “The Determination of Antibiotics in Milk with Special Reference to Penicillin.” By N.J. Berridge, “The Determination of Antibiotic Residues in the Tissues and Body Fluids of Animals.” By By J. M. Ross, M.B., Ch.B., D.P.H., D.Obst.R.C.0.G. B.Sc., Ph.D. J. H. Taylor, Ph.D., M.R.C.V.S. October, 1957, in London: “The Analysis of ‘Ferrites’ by Means of EDTA.” “The Determination of Mercury by Direct Distillation in its Compounds and Preparations.” “A System for the Determination of Certain Trace Metals in Crops.” “Some Applications of X-ray Spectrography . By D. G. Timms, B.Sc., A.R.I.C. By H. E. Brookes, B.Sc., F.R.I.C., and I,. E. Solomon, BSc. By W. D. Duffield. By H. I. Shalgosky, B.Sc., A.R.I.C. November, 1957, in London: “Recent Developments in Chelatometry.” By Dr.Rudolf Pgibil.May, 19581 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 255 December, 1957, in London, discussion on Standardisation opened by: R. C. Chirnside, F.R.I.C. L. S. Theobald, M.Sc., A.R.C.S., F.R.I.C. J. Haslam, D.Sc., F.R.I.C. G. Ingram, A.R.I.C. (In illr. Theobald’s absence through illness, his contri- bution was read by Mr. Chirnside.) February, 1958, in London, organised by the Microchemistry Group : “Applications of the Conway Diffusion Technique to the Analysis of Radioactive Materials for “The Use of Long-chain Quaternary Amine Salts in the Solvent Extraction of Metal Ions.” By Trace Impurities.” R. Powell, A.R.I.C. By J. K. Foreman, BSc., A.R.I.C. JOINT MEETING-AS mentioned above, the Society held a Joint Meeting with the Fine The By H.M. N. H. Irving, Chemicals Group of the Society of Chemical Industry in March, 1957, in London. following paper was presented and discussed- “Organic Reagents in Inorganic Analysis: Some Recent Developments.’’ M.A., D.Phil., D.Sc., F.R.I.C., L.R.A.M. NORTH OF ENGLAND SECTION-The membership of the Section, at 391, shows no signifi- cant change. A questionnaire was circulated in the early part of the year to ascertain members’ views with regard to future activities of the Section. This gave encouraging results and it is hoped that action being taken with these in mind will bear fruit in the coming year. During the year, six meetings have been held, including the traditional Summer Meeting. Attendances at these were up to average.The following papers were read and discussed- January, 1957, in Manchester : March, 1957, in Liverpool: May, 1957, in Llandudno: October, 1957, in Manchester : November, 1957, in Widnes : “Recent Advances in the Analysis of Fertilisers.” By H. N. Wilson, F.R.I.C. “The Composition of Exhaust Gases.” By A. Pitton, D.Sc., M.1.Chem.E. “Some Chemical Features of the Composition of Fruit Juices.” By V. L. S. Charley, B.Sc., Ph.D. Discussion Meeting on “The Analysis of Trade Effluents,” opened by J. G. Sherratt, B.Sc., F.R.I.C. “Ion-exchange Chromatography Applied to Closely-related Organic Compounds” and “Trace- element Determinations with the Aid of Ion-exchange Membranes.” By D. Logie, B.Sc. December, 1957, in Liverpool : “Present Trends in the Analysis of Feedingstuffs.” By H.Pritchard, M.Sc., F.R.I.C. SCOTTISH SECTION-The outstanding event of the past year was the St. Andrews Congress on Modern Analytical Chemistry in Industry held in June. Normal activities of the Section were not neglected, however, a full programme of meetings being arranged. In addition to the twenty-second Annual General Meeting held in Glasgow, at which various alterations to the Section Rules were passed for submission to Council for approval, four scientific meetings were held, two each in Glasgow and Edinburgh. As a member of the Federation of Chemical Societies in Glasgow, the Section was represented at the Ramsay Chemical Dinner. An innovation was the introduction of a discussion meeting into the programme, and for the first time a meeting has been held jointly with the Department of Chemistry of the University of Edinburgh, Dr.Pfibil’s lecture and demonstration being ideal for this occasion. The death of Mr. A. Dargie, one of the founder-members of the Scottish Section, is recorded with regret. The following papers have been presented and discussed- The total membership of the Section is now 122. Glasgow, February, 1957 : “Some Recent Developments in Analytical Chemistry.” By R. Belcher, Ph.D., D.Sc., F.R.I.C., F. 1nst.F.256 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 [Vol. 83 Edinburgh, March, 1957 : “Some Aspects of the Estimation of Uronic acid in Carbohydrate Material.” “The Routine Semi-micro Determination of Molecular Weights.” By D. &I. W. Anderson, By J. Brooks, M.A., A.R.I.C., B.Sc., Ph.D., A.R.I.C.and A. F. Williams, B.Sc., F.K.I.C. St. Andrews, June, 1957: “Analytical Chemistry in Industry.” “Analytical Research in the Department of Scientific and Industrial Research in Relation to “Modern Analytical Methods in the Iron and Steel Industry.” “Steelworks Analysis by Spectrographic ]Methods.” “Chemical Problems in the Electrical Industry : The Contribution of Analysis as a Research Service.” “The Application of Physical Methods of Analysis in the Gas Industry.” By A. B. Densham, “The Work of the Department of the Govcrnment Chemist.” By G. M. Bennett, C.B., B.A., Yh.D., “Analytical Developments in a Pharmaceutical Laboratory.” By D. C. Garratt, D.Sc., Ph.D., “Analysis and Food.” “Recent Progress in Separating Substances of High Molecular Weight.” “Emission Spectroscopy in Industrial Aiialysis.” “Analysis in Medical Research.” “The Analyst and Infra-red Spectroscopy.” “Modern Analytical Chemistry in Relation to the Plastics Industry.” By J.Haslam, D.Sc., F.K.I.C. “Modern Analytical Chemistry and the Rarer Metals.” By A. R. Powell, F.I.M., F.R.I.C., F.R.S. “Analytical Research in the Nobel Division of Imperial Chemical Industries.” By A. F. Williams, B.Sc., F.R.I.C. “Process Analytical Control: The Problems of Manpower, Productivity and Automation.” By B. W. Bradford, B.Sc., Ph.D., A.R.C.S., D.I.C., F.R.T.C., and D. L. Nicholson, B.A. “New Analytical Reagents and their Applications in Industrial Plant-control Operations.” By Professor G. F. Smith, 1’h.D. “The Use of Radioactive and Stable Isotopes in Industrial Analytical Problems.” By A.A. Smales, B.Sc., F.R.I.C., and D. J . Ferrett, M.A., D.Phi1. “An Approach to Automatic Analytical Measurements.” “Polarography.” By G. C. Barker, M.A., Ph.D., G. W. C. Milner, M.Sc., A.Inst.P., F.R.I.C., and H. I. Shalgosky, BSc., A.R.I.C. “The Application of Gas Chromatography in the Petroleum Industry.” By Dr.-Ir, A. I. 31. Keulemans. By J . Craik, M.A., B.Sc., Ph.D. Industry.” By G. R. Davies, B.Sc., M.Sc., Ph.D. By B. Bagshawe, A.Met. By D. Manterfield, F.I.M. By R. C. Chirnside, F.K.I.C. M.A., M.Inst.Gas E., and G. Gough, B.A. M.A., Sc.D., F.R.I.C., F.R.S. F. R. I.C. By E. H. Hughes, D.Sc., F.R.I.C. By R. L. 11.1. Synge, B.A., Ph.D. , F.R.S., Nobel Laureate. By M. Milbourn, B.Sc., A.R.C.S., F.1nst.P. By A. T. James, B.Sc., Ph.D.By A. E. Martin, D.Sc., Ph.D. By D. A. Patient, B.Sc., A. 1nst.P. “The Geochemical Approach D.Sc., F.G.S., 1J.K.S.E. to Prospect:ing for Minerals.” By Professor C. F. Davidson, O.B.E., Glasgow, October, 1957 : Discussion Meeting on “The Estimation of Additives to Bread and Flour,” opened by J. Sword, M.A., B.Sc., Ph.D., F.R.I.C., A. N. Harrow, A.H.-W.C., P.R.I.C., and H. C. Moir, H.Sc., F.R.I.C. Edinburgh, November, 1957, Joint Meeting : “A Xew Line in the Development of Metal Indicators.” By Dr. Rudolf PPibil. WESTERN SECTioN-The membership of the Section is 85. The meetings have all been very well supported with an average attendance of about 40 members and lively discussions have followed the lectures. The Summer Meeting was very successful and was the first joint meeting held with another Section.The results were promising, and it has been decided to hold further meetings of a similar character. The policy of joint meetings with other chartered bodies has been maintained in outlying areas, the results proving very satisfactory. The following papers have been presented and discussed- Plymouth, January, 1957 : “Silicosis.” By Prokssor E. J. King, K A . , Ph.D., D.Sc., F.R.I.C. Bristol, February, 1957 : “The Oxygen Demand of Trade Effluent: with Respect to River Pollution.” By C. J. Regan, B.Sc., F.R.I.C. Swansea, March, 1957 : €7.13. I. c. “Some Recent Developments in Metalliirgical Analysis.” By G. W. C. Milner, MI.%., A.Inst.P.,May, 19581 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 257 Cheltenham, May, 1957, jointly with the Midlands Section : “Recent Advances in the Analysis of Plastics.” “The Analysis of Titanium, Zirconium and their Alloys.” “The Analysis of the Rarer Elements of Group 111.” By J.Haslam, D.Sc., F.R.I.C. By W. T. Elwell, F.R.I.C. By A. R. Powell, F.I.M., F.R.I.C., F.R.S. Exeter, September, 1957, jointly with the Microchemistry Group, on Some Applications of Microchemistry : “Applications to Paints and Pigments.” “Applications to Soils and Fertilisers.” Iliscussion on “The Use and Abuse of Microchemistry,” opened by C. L. Wilson, D.Sc., Ph.D., By C. Whalley, B.Sc., F.R.I.C. By B. M. Dougall, M.Sc., F.G.S., A.R.I.C. F.R.I.C., and S. Bance, B.Sc., A.K.I.C. Newport, October, 1957, jointly with the Physical Methods Group: “Atoniic Absorption Spectroscopy.” “Recording Flame Photometry.” By 4 .C. Menzies, M.A., D.Sc. By L. Brealey, B.Sc. Rristol, November, 1957, jointly with the Association of Public Analysts : “Instrumentation in Radioactive Analysis.” “The Effects of Radiation on Living Cells.” “Radioactivity in Sea Foods and Waters.” By G. V. James, M.B.E., M.Sc., P1i.D.. F.R.I.C., “Radioactivity and its Detection in Effluents.” By E. Minshall, M.Sc., F.R.I.C. By H. F. Freundlich, M.A. P. A. I. W. E . By R. €3. Burns, B.Sc., F.R.I.C. Salisbury, November, 1957 : Newport, December, 1967 : “Current Practice in Chemical Pathology.” By I. MacIntyre, M.B., B.S. “Inorganic Chromatography.” By F. H. Pollard, B.Sc., Ph.D. MIDLANDS SECTION-The membership of the Section is 316, an increase of 9 during the year.During 1957, 12 ordinary meetings have been held; of these, two were held jointly with the Birmingham and Midlands Section of the Royal Institute of Chemistry, one with the Microchemistry Group and one with the Physical Methods Group. A two-day meeting in Cheltenham was held jointly with the Western Section. The average attendance at meetings was 45. The following papers were presented and discussed- Birmingham, January, 1957 : “The Analytical Chemistry oi Some Newer Insecticides and Herbicides.” By K. Gardner, B.Sc., F.R.I.C. Nottingham, January, 1957 : “Some Contradictions and Discrepancies Concerning a Classical Method of Analysis.” By R. Birmingham, February, 1957, jointly with the Physical Methods Group, on High Frequency Belcher, Ph.D., D.Sc., F.R.I.C., F.1nst.F.Tit rat ions : “Instrumentation.” By J. Allen, A.R.I.C. “Applications.” By E. S. Lane, B.Sc., Ph.D., F.R.I.C. Birmingham, March, 1957 : Nottingham, March, 1957 : Birmingham, April, 1957 : Birmingham, May, 1957, jointly with the Microchemistry Group, on The Microdetermination By W. I. Stephen, B.Sc., Ph.D., “Thermo-gravimetric Analysis.” By Professor C. Duvsl. “The Analysis of Complex Sulphur Compounds.” By C. E. Kendall, BSc., A.R.I.C. “The Analytical Chemistry of Beryllium.” By E. Booth. of Functional Groups : “Some Developments in the Analysis of Functional Groups.” “The Determination of X-Methyl Groups.’ “The Determination of Equivalents.” “Titrations in Non-aqueous Media on the Sub-micro Scale.” A.R.I.C. By M. K. Bhatty, M.Sc., A.R.I.C. By T.S. West, Ph.D., A.R.I.C. By T. S. West, Ph.D., A.R.I.C.258 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 [Vol. 83 Cheltenham, May, 1957, jointly with the Western Section : Birmingham, September, 1957 : Details of the papers read a t this meeting are given in the report on the Western Section. “The Determination of Some Inorganic Substances in Trade Effluents.” By N. T. Wilkinson, F.R.I.C. Birmingham, October, 1957 : Nottingham, October, 1957 : Birmingham, November, 1957 : Nottingham, December, 1957 : “hTon-aqueous Titrations.” Birmingham, December, 1957 : “Analytical Methods in Clinical Biochemistry.” By H. Varley, M.Sc., F.R. I.C. “The Analytical Chemistry of Morphine Poisoning.” By A. S. Curry, M.A., Ph.D. “A New Line in the Development of Metal Indicators. By Dr.Rudolf Hibil. By H. H. Tinley. “The Analytical Chemistry of Copper and its Alloys.” By H. J. G. Challis, F.R.I.C., A.I.M. MICROCHEMISTRY GROUP-The membership of the Group is now 618, an increase of 41 in the past year. During 1957 three ordinary meetings of the Group were held: in London (a meeting of the Society organised by the Group) ; in Birmingham (together with the Midlands Section) and in Exeter (together with the Western Section). London, Micro-volumetric Analysis : B.Sc., Ph.D., A.R.I.C.) “Apparatus and Technique.” “Primary Standards.” “End-point Location.” By D. W. Wilson, MSc., F.R.I.C. By R. Belcher, P h .D., D.Sc., F.R.I.C., F.1nst.F. (Read by J. H. Thompson, By E. Bishop, B.Sc., A.R.T.C., A.R.I.C. Birmingham : The Microdetermination of Functional Groups : Exeter : Some Applications of Microchernistry : The papers presented a t this meeting are detailed in the report on the Midlands Seccion The papers presented a t this meeting are detailed in the report on the Western Section.Six informal discussion meetings have been held, five in London and one in Exeter. The following topics were discussed- Review of Previous Topics. “The Microdetermination of Halogens,” introduced by F. Oliver and R. Goulden, A.R. I.C. “The Microdetermination of Functional Groups,” introduced by W. I. Stephen, B.Sc., Ph.D., “The Use and Abuse of Microchemistry,’ introduced by C. I,. Wilson, D.Sc., Ph.D., F.R.I.C., and “British Standards in Microchemistry,” introduced by C. Meredith and G. Ingram, A.R.I.C. “The Weighing and Measuring of Small Quantities,” introduced by G.F. Hodsman, B.Sc., Ph.D., (Jointly with the Biological Methods Group.) A.R.I.C., and G. Ingram, A.R.I.C. S. Hance, B.Sc., A.R.I.C. (At Exeter.) A.Inst.P., and R. Goulden, A.R.I.C. PHYSICAL METHODS GROUP-The me:mbership of the Group is now 657, an increase of 30 since the last Annual Report. During the past year the Group has held four Ordinary Meetings and also organised the April meeting of the Society. Two of the Group meetings were held in London and one each in Birmingham and Newport. The Birmingham meeting was held jointly with the ?Midlands Section and the Newport Meeting jointly with the Western Section. The meetings had an average attendance of over 45 members and visitors. Following the Annual General Meeting on November 2Sth, 1956, W.Klyne, M.A., B.Sc., Ph.D., delivered a lecture entitled, “Optical Rotations in the Study of Organic Structures,” and J. Evans described briefly and demoristrated a prototype model of a commercial photo- electric polarimeter. The following papers were read and discussed at other ordinary meetings of the Group- High Frequency Titrations-Birmingham, February, 1957 : Details of the papers read a t this meeting arc given in the report on the Midlands Section.May, 19581 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 259 Electrochemistry-London, May, 1957 : “Coulometric Titrations with an Integrated-current Source.” “Pulse Polarography.” By L. E. Smythe, M.Sc., Ph.D., A.R.I.C., F.R.A.C.I. (Read by G. W. C. Milner, M.Sc., A.Inst.P., F.R.I.C.) By A.W. Gardner, BSc. Flame Photometry-Newport, October, 1957 : Details of the papers read a t this meeting are given in the report on the Western Section. BIOLOGICAL METHODS GROUP-& present the membership of the Group is 293, an During the year the Committee has arranged two meetings In addition increase of 21 since last year. for the presentation of papers, one of which was on behalf of the parent Society. four Discussion Meetings have been held, together with a laboratory visit. November, 1956, London : January, 1957, London : Discussion on “Biological Assays in the Analytical Laboratory,” introduced by K. L. Smith, M.P.S. Discussion on “The Relationship Between Statistics and Microbiological Assay,” introduced by J. P. R. Toothill, B.Sc., A.R.I.C. March, 1957, London : Discussion on “The Experimental Assessment of Tranquillisers,” introduced by A.Spinks, B.A., B.Sc., Ph.D., D.I.C. April, 1957, London : “Experience in the Microbiological Assay of Vitamins and Amino Acids by Large-plate Methods.” “Quantitative Analysis of Immunologically Specific Substances in Agar-gel Plates.” By J. G. Fein- By D. F. Harris and J. S. Simpson, F.I.M.L.T. berg, B.Sc., D.V.M., 1LI.Sc. May, 1957, London, on Estimation of Antibiotic Residues in Food: Details of the papers read at this meeting are given in the report on the Ordinary Meetings of the Society. October, 1957, London : Discussion on “Biological Standards,” introduced by J. W. Lightbown, M.Sc., Dip.Bact., F.P.S. ANALYTICAL METHons COMMITTEE-The work carried out by the Committee, Joint Committees and their Sub-committees and Panels during the year shows that last year’s progress has been maintained and there has been a steady output of recommended methods of analysis.Two technical Reports were published by the Analytical Methods Committee, namely, the report of the Essential Oils Sub-Committee on the Determination of Linalol, in May, and the report of the Pesticides Residues in Foodstuffs Sub-committee on the Determination of Total Organic Chlorine in Solvent Extracts of Vegetable Material, in June. The A.B.C.M. - S.A.C. Joint Committee on Methods of Analysis of Trade Effluents has had a very active year and has now completed its programme of work. As was the practice last year, the methods were published in The Andysf as soon as they were approved, and these occupied a total of 64 pages as compared with 32 pages last year, All the methods have now been assembled and will be published as a complete booklet this Spring.Difficulties were encountered in finding a method for silver in effluents that would be applicable for determining amounts of the order of 0.01 p.p.m. It was considered that the problem was worthy of further investigation and accordingly a grant by the Analytical Methods Trust has been made available to Dr. H. M. N. H. Irving to direct a short-term programme of research. The four working Panels of the Joint Committee with the Pharmaceutical Society on Methods of Assay of Crude Drugs have continued with collaborative experimental work during the year, and a fifth Panel was appointed to investigate methods of assay of Lonchocarpus and Derris.In the work of the Analytical Methods Committee itself, the Trace Elements in Fertilisers and Feeding-stuffs Sub-committee has been reconstituted under the Chairmanship of Mr. C. J. Regan and is carrying out some collaborative trials of methods before final recommenda- tions are made. Other Sub-Committees are continuing their investigations : the Metallic260 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 [Vol. 83 Impurities in Organic Matter Sub-Committee and the Vitamin-E Panel are each preparing final reports. Arrangements have been made with the Ministry of Agriculture, Fisheries and Food and the Association of British Insecticide Manufacturers to carry out collaborative experimental work on methods for determining residues of pesticides on foodstuffs; methods for BHC and DDT are to receive immediate attention.A full Report of the Analytical Methods Committee covering the years 1965, 1950 and 1957 (i.e., the first 3-year period since the Committee’s reorganisation) is being prepared and will be published separately. Xr. I‘. T. Gorsuch, the Society’s first Research Scholar, has continued his work at I-Iarwell under the able direction of Illr. A. A. Srnales. The work has entailed the application of radiochemistry, using radioactive tracers; as well as gamma spectrometry after neutron activation, (a) to the specific problem of defining the losses that can occur during the prepara- tion of organic materials for trace-element analysis, investigating the causes of these losses and determining the optimum conditions for their elimination, and (b) to the various individual problems that have confronted the Metallic Impurities in Organic Matter Sub-committee in its work.LIAISON COMhfITTEE-\ve record with pleasure that Dr. K. A. Williams was elected during During the year the following appointments were made- Mr. S. A. Price, Chemical Divisional Council. Dr. S. G. Burgess, Methods of Test fcir Surface Active Agents. Mr. P. J. C. Haywood, Standards for Pentachlorophenol, Determination of Tar Acids in Dr. H. Liebmann, Standardisation of Optical Cells and Colour Filters. the year to the General Council of the British Standards Institution. R.§.I. Committees: Disinfectant Fluids. Joint Library Committee, Chemical Society : Dr.J, G. A. Griffiths was again appointed the Society’s representative. Mr. R. C. Chirnside and Dr. J. Haslani represented the Society a t the Eleventh Chemists’ British Iron and Steel Research Association : Conference of the Methods of Analysis Committee (Metallurgy, General Division). Parliamentary and Scientific Comniittee : Mr. G. Taylor continued to represent the Society. Dr. J. Haslain and Mr. C. Whalley. The Council of the Society thanks all its representatives for the work they have carried out in the various Committees and at varied meetings during the year. HONORARY TREASURER’S REPORT-The accounts for the year ending October 31st, 1957, amply justify the decision of the Council to increase members’ subscriptions and the prices of the Society’s publications to outside subscribers.Despite the expense of moving into the new headquarters and of increasing the reserve for the decennial index, the deficit on each of the publication accounts before the receipt of the grant from the Chemical Council was re- duced by over ,@OO. Furthermore, even in the absence of a grant from the Chemical Council, the over-all deficit would have been little over L1000 compared with a deficit of nearly E4000 in the absence of a grant in the previous year. No doubt because we had thus attempted to put our house in order and because the sum we asked for was not great the Chemical Council met our request in full, and we are most grateful for this generous response to our appeal. Enabled thus to balance our publications account, we have in place of an over-all deficit a surplus of income over expenditure.This, however, is no reason for complacency. We cannot count on continued aid from the Chemical Council and indeed it is our desire to become self-supporting. We have made a move in this direction, but faced as we are already with increased costs for staff and for printing and Royal Institute. of Chemistry, Summer School Organising Committee :May, 19581 ANNUAL REPORT OF THE COUNCIL: FEBRUARY, 1958 261 distribution and with requests for enlarged journals, we may be forced to increase again the cost of our publications to outside subscribers. THE ANALYsT-The 1957 volume contained 840 pages, compared with 732 in 1956. The numbers of papers and notes published in 1957 were 93 and 52, respectively, against 93 and 30 in 1956.One paper was a Review Paper. When allowance is made for all matter other than papers and notes, and the Review Paper is excluded, the average length of a paper or a note is 4.7 pages. This is a fifth of a page greater than the average for 1956, which was itself the same as the 1954 figure. It seems necessary to repeat the warning given last year that it is essential to keep papers to the smallest possible size unless the publication of analytical knowledge is to suffer. A revised “Notice to Authors” intended to procure a reduction of the length of manuscripts has been issued during the year. Besides the usual items, summaries of 8 papers presented at meetings but not being published in full in any journal were published in the Proceedings of the Society, one summary being in effect a short Review Paper.The Recommended Methods for the Analysis of Trade Effluents prepared by the Joint A.B.C.M. - S.A.C. Committee and published during the year occupied 642 pages. Ten issues of the Bulletin were distributed with The Analyst during the year, one of them being a special issue containing the programme of the Congress on Modern Analytical Chemistry in Industry at St. Andrews, organised by the Scottish Section. Mr. N. C. Francis resigned the post of Assistant Editor at the end of October, 1957, and Mr. P. W. Shallis was appointed in his place. Mr. B. Harris has joined the editorial staff to fill the vacancy. The number printed of each issue, 6400, appears to be adequate to meet demands and to leave a small stock of single parts available for purchase as back numbers, and for the first time in many years this number has not been increased. The total increase in the previous two years was 1100. ANALYTICAL ABSTRACTS-Analytical Abstracts again showed an increase in size in 1957 as is shown by the following figures- 17ear Pages Abstracts 1954 392 3190 1955 468 3556 1956 542 3820 1957 568 4223 The number of abstracts has increased in a greater proportion than the number of pages owing to the policy of reducing the length of the less important abstracts. The rate of payment to abstractors has been increased. Mr. C. H. R. Gentry joined the Abstracts Committee in June, 1957. The number of copies printed per month was 7000 from January to September inclusive. This was reduced to 6600 from October to December inclusive, but has again been raised to 7100 for January, 1958. CHEMICAL comcrL-The increase in the price of The Analyst to outside subscribers greatly reduced the deficit in the Society’s accounts. It was necessary, however, for the Society to apply to the Chemical Council for El700 and Q050 in order to balance the accounts, respectively, of The APzalyst and Analytical Abstracts. These amounts were paid in full, and the thanks of the Society are tendered to the Chemical Council for this grant. CONFERENCE OF HONORARY SECRETARIES-Another successful meeting of the Honorary Secretaries of the Sections and Groups of the Society was held on May 22nd, 1957. These meetings are of value to all concerned and enable the President and Honorary Officers to discuss freely with the Honorary Secretaries all matters related to the organisation and future of the Society. J. HAMENCE, President. R. E. STUCKEY, Honorary Secretary.

ISSN:0003-2654    

DOI:10.1039/AN9588300253

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

262 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 [Vol. 83 Report of the Analytical Methods Committee 1957 EACH of the two preceding annual Reports of the Analytical Methods Committee of the Society for Analytical Chemistry covered the work of one year. This present Report, however, reviews the three years that have elapsed since the Committee was reorganised as a self-supporting unit of the Society. ’This over-all account of the Committee’s work is given because many of the subscribers to the Trust Fund, who so generously responded to the Society’s appeal at the end of 1954, initially promised donations for three years to establish the Committee’s work. GENERAL REVIEW In the early part of 1957 the Committee was very sorry to lose, through resignation, Dr. J. K. Nicholls and Mr.N. L. Allport, both of whom had been valued members for many years, and the opportunity is taken here to thank them for all their help. The Committee was glad to welcome in June Mr. E. Q. Laws and Mr. C. Whalley as their successors. PROGRESS OF WORK- Originally the secretarial work of the Committee itself and each of its sub-committees and panels was undertaken voluntarily by one of the members, all of whom had full-time duties in their own spheres of work. Not only had it become necessary to relieve members of the onus of this secretarial work, but it became increasingly difficult to extend the field of investigation and a central paid secretariat became essential. This led to the Appeal to Industry to put the Committee on a sound financial basis. The present arrangement of having a small technical secretariat office within the Society’s offices has been much appreciated by committee members and has facilitated co-ordination and enabled quicker progress to be made.Further, because the office also acts in an editorial capacity, the time between the completion of the collaborative work of a committee and the publication of its reports has been greatly reduced. These advantages have been well demonstrated by the rapid progress of work by the Joint Committee on Methods for the Analysis of Trade Effluents set up by the Society and the Association of British Chemical Manufacturers in 1954. In view of Industry’s need for recommended methods, the priority given to this work has maintained a steady output and ensured that the methods appeared in print as soon as possible after they were approved.The effort has been well rewarded, since tlhe Joint Committee with its four working panels completed its entire programme (much of it entailing collaborative experimental work) by the end of 1957 and has published in The Analyst no less than 46 methods since the beginning of 1956. These, together with the remaining 6 methods just completed, are being collected and will be published in the Spring of 1958 as a complete volume of some 150 pages. The Analytical Methods Committee itself has published 3 reports of original collaborative work carried out by its sub-committees-one of these, “The Estimation of Vitamin B,,,” was published in The Aua2yst in 1956 and the other two, “The Determination of Linalol in Essential Oils” and “The Determination of Small Amounts of Total Organic Chlorine in Solvent Extracts of Vegetable Material,” iin 1957.In other sub-committees, collaborative experimental work is still in progress, but lit is expected that the results of some of this will be ready for publication in 1958. The arrangement for investigating analytical problems by collaboration between two or more organisations, as exemplified by the work on the analysis of trade effluents, proved to be so satisfactory that another Joint Committee, this time with the Pharmaceutical Society, was set up in March, 1956, to prepare standard methods of assay of crude drugs and kindred materials, such as those that are used widely in commerce, but for which there are no standard or official methods at present in force.This Joint Committee immediately appointed four working panels to investigate chemical methods for digitalis, capsicum (capsaicin content), anthraquinone drugs and rauwolfia, respectively. A fifth panel, to investi- gate methods for the assay of lonchocarpiis and derris, was appointed in July, 1957. All five panels are actively engaged in experimental work and it is interesting to note that eachNay, 19583 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 263 panel has, from the first, turned its attention to a thorough study of the active ingredients of the crude drugs. Further evidence of the value of joint investigations by several organisations has been the recent agreement by the Society (represented by the Analytical Methods Committee) to collaborate with the Association of British Insecticide Manufacturers and with the Scientific Sub-committee on Poisonous Substances used in Agriculture and Food Storage of the Ministry of Agriculture, Fisheries and Food to test methods of analysis for pesticides residues in foodstuffs.In this investigation, the secretarial work is to be undertaken by the Ministry and ad hoc working panels are to be appointed when methods are considered ready for collaborative trial. More detailed accounts of the work of the various Joint Committees, sub-corninittees and panels are given later in this Report. ANALYTICAL METHODS TRUST- The Committee is fortunate in having Mr. Justice Lloyd-Jacob as Chairman of the Analytical Methods Trust; it owes much to his direction of its financial affairs and to his lively interest in the progress of work.A successful 3-year trial period has been completed-an achievement that would not have been possible without the very generous help during this period from the many sub- scribers to the Trust Fund. Its future work will, however, depend on an assured income; in order to secure this, the Trustees are to appeal to Industry for the continuation of the subscriptions to the Trust Fund. RESEARCH GRANTS- In the past, the work of a committee frequently suffered because members found it impossible to investigate problems fully, since the amount of work involved would have required concentrated research. It was hoped, therefore, that the Trust Fund formed by subscriptions received as a result of the Appeal to Industry in 1954 would be large enough to allow some money to be set aside for research purposes after the secretariat’s expenses had been met.It was most gratifying that the response was such that the first grant could be made a few months after the Com- mittee was established on its new basis, with the result that a Research Scholar was appointed to carry out full-time work for a period of 2 years on a problem frequently encountered by analysts-namely, the causes of losses or accretions of some metals during the destruction of organic matter. Again, at the end of 1957, it was possible to make a second grant to permit full-time research on the investigation of a problem that had arisen in the course of the work of the Joint Committee engaged in devising methods of analysis of trade effluents.In addition to making these specific grants for research, it has been possible to help in the work of the Joint Committee that is investigating methods of assay of crude drugs by the purchase of special materials. As the work of the various committees continues to expand, it is envisaged that further grants for research will be made in the near future. Research scholarship-Mr. T. T. Gorsuch, the Society’s first Research Scholar, was appointed at the beginning of 1956 to work at the Atomic Energy Research Establishment, Harwell, mder the direction of Mr. A. A. Smales, and the Society is grateful to the Director of that Establishment for the facilities afforded there. The research is nearing completion and an account will shortly be published; it is also expected that the results will be of sufficient general interest to be the subject of a paper for presentation at one of the Society’s meetings.The research work has entailed the application of radiochemistry, by means of radioactive tracers as well as gamma spectrometry after neutron activation, (a) to the specific problem of defining the losses that can occur during the preparation of organic materials for trace- element analysis, investigating the causes of these losses and determining the optimum conditions for their elimination, and (6) to the various individual problems that have confronted the Metallic Impurities in Organic Matter Sub-committee in its work. Research on methods for the determination of traces of silver-The grant made recently by the Trustees is being used for research, under the direction of Dr.H. M. N. H. Irving[Vol. 83 at Oxford, to devise a method for the deterniination of traces of silver in the presence of organic matter. This arose from the work of the Joint Committee on Methods for the Analysis of Trade Effluents, which indicated that, in the event of accidental contamination of rivers by silver, a method should be available for determining amounts down to 0-01 parts per million. It was envisaged that the work would take about 6 months. INCOME AND EXPENDITURE- The audited statement of accounts (see Appendix I) for the financial year ending October 31st, 1957, shows an expenditure of L4774. This figure includes expenses in con- nection with the Research Scholarship (the grant of A600 for research on silver analysis was not approved until after the end of the financial year) and shows an increase of A1419 over last year’s figure.The income from donations for 1957 amounted to A5900 received from 49 subscribers -about L450 less than was received in 1956. Of the organisations that supported the original appeal in 1954, 17 per cent. entered into 7-year Deeds of Covenant and 33 per cent, promised annual donations for a period of 3 years; the remaining 50 per cent. of the subscribers preferred to consider the matter from year to year. In view of the uncertain income derived in this way, the Trustees considered that it would be prudent to build up a reserve during the 3 years whilst the Committee established itself so that the various sub-committees and panels could be assured of the continuance of their work.For this reason, although the Committee’s work has expanded steadily, a reasonable economy has been observed diiring this time and the secretariat staff of three has not been increased. However, after the initial period in which considerable work has been undertaken, as can be seen from the report that follows, the potential value of the Committee’s work to Industry has become apparent and an ever-increasing programme of work must be expected. This can only be done with an assured income. It is hoped that the support given by Industry will continue so that this more ambitious programme can be undertaken with confidence. 264 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 REPORTS OF SUB-COMMITTEES OF THE ANALYTICAL METHODS COMMITTEE ESSENTIAL OILS SUB-COMMITTEE CONSTITUTIOX- G.W. Ferguson, B.Sc., Ph.D., F.R.I.C. A. J. M. Bailey, B.Sc., F.P.S., F.R.I.C. D. Holness, R.A. H. T. Islip, B.Sc., F.R.I.C. P. McGregor, B.Sc., A.H.-W.C., F.R.I.C. J. H. Seager, M.Sc., F.R.I.C. G. E. Smith, B.Sc., F.R.I.C. B. D. Sully, B.Sc., Ph.D., A.R.C.S., F.R.I.C. (Chairman) Analytical and ConsulEing Chemist W. J . Bush & Co. Ltd. Unilever Ltd., Central Perfumevy Department TroFical Products Institute Department of the Government Chemist Yardley G. Co. Ltd. Staffoord Allen & Sons Ltd. A . Boake, Roberts & Co. Ltd. PROGRESS OF WORK- When the Analytical Methods Commit tee was reorganised in 1955, some sub-committees were automatically dissolved and subsequently reconstituted because the scope of work had been broadened.The original Essential Oils Sub-committee, however, continued in being until the report of their collaborative work on methods for the determination of linalol had been completed. This report was eventually published in The Amlyst in May, 1957. The Sub-committee was reorganised in February, 1957, under the Chairmanship of Dr. G. W. Ferguson. One meeting has since been held, and it was considered that the future programme of work would depend somewhat on requests for collaboration from the corre- sponding technical committee of the British Standards Institution. MEAT PRODUCTS SUB-COMMITTEE CONSTITUTION- S. M. Herschdoerfer, Ph.D., F.R.I.C. S. Back, B.Sc., F.R.I.C.(Chairman) T. Wall & Sons Ltd. Crosse & Btackwell Ltd.May, 1958] REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 265 British Food Manufacturing Industries Research 0x0 Ltd. Department of the Government Chemist 0x0 Ltd. Miss E. &I. Chatt, B.Sc., F.R.I.C. C. D. Essex, A.M.Inst.B.E., F.R.I.C. J. R. Fraser, B.Sc., A.C.G.F.C., F.R.I.C. H. G. Kees, B.Sc., Ph.D., A.R.C.S., D.I.C., Association F. R. I .C. H. Amphlett Williams, Ph.D., A.C.G.F.C., Public Aizalyst F. R. I .C. TERMS OF REFERENCE-'' (a) The determination of the meat content of products containing meat; (b) the determination of the constituents of meat and meat products. Nom-The term 'meat products' to include hydrolysed protein and, if found necessary, fish pastes." PROGRESS OF WORK- The previous Sub-Committee, under the name of the Meat Extracts Sub-Committee, was dissolved in 1855 and reconstituted with extended terms of reference and a title indicative of its wider scope.Collaborative experimental work is being undertaken with particular reference to review- ing the values of the factors for nitrogen for various types of meat, since some dissatisfaction of existing values has frequently been expressed. The need for establishing values within closer limits than hitherto is directly associated with new legislation under the Food and Drugs Act, in which the meat content of sausages and meat pies might be stipulated; in this event reliable tests for compliance with the ,4ct would be necessary. In addition, methods for the determination of starch are under review during the collaborative tests.METALLIC IMPURITIES IN ORGANIC MATTER SUB-COMMITTEE CONSTITUTION- T. McLachlan, D.C.M., A.C.G.F.C., M.I.Biol., Public Analyst L. Brealey, BSc. Boots Pure Drug Co. Ltd. J. C. Gage, R.Sc., Ph.D., F.R.1.C.t Imperial Chemical Industries Ltd. (Industrial Hygiene Laboratories) C. L. Hinton, F.R.I.C. British Food Manufacturing Industries Research A ssociation E. I. Johnson, M.Sc., F.R.I.C. Department of the Government Chemist 'CV. C. Johnson, M.B.E., F.R.I.C. Hopkin & Williams Ltd. I. MacIntyre, M.B., Ch.B. University of London (Post-Graduate Medical R. F. Milton, B.Sc., Ph.D., M.I.Biol., F.K.I.C. Analytical and Consulting Biochemist G. Taylor, O.B.E., F.R.I.C." Public Analyst, Oficial Agricultural Analyst and G.E. Willis, B.Sc., Ph.D., A.R.I.C. Imperial Chemical Industries Ltd. (Dyestufis F.R. I.C. (Chairman) School) Consulting Chemist Dizlision) * Resigned-November, 1957. t Elected-December, 1957. TERMS OF REFERENCE-"TO investigate the determination of small quantities of metals in organic matter." PROGRESS OF WORK- In the course of its work on the methods for both arsenic and lead, the Sub-Committee came to the conclusion that one of the chief reasons for variation in experimental results could be attributed to the losses or retention occurring during the destruction of organic matter. Accordingly it was decided that the reports on the trace metals should be confined to the method of determination of the element with only general reference to the preliminary treatment.Methods for the destruction of organic matter in general, with recommendations for appropriate procedure in particular cases, should be dealt with in a separate report, which is now under consideration. The Sub-Committee came to the conclusion that the use of perchloric acid in the pre- liminary treatment of the sample should be encouraged and it has prepared a note for publication as a guide to the precautions that should be taken and the conditions under which perchloric acid may be used with safety.266 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 [Vol. 83 Investigations into the molydenum-blue method for the determination of arsenic are now in the final stage; after preliminary collaborative tests with simple solutions of arsenic, a series of tests on samples containing organic matter has been carried out and the results compared with those obtained by radiochemical methods at Harwell.A report on the work and on the method is in preparation. Experimental work on the revised method for lead has been completed and it is hoped that the final report will be approved shortly. The recommended methods for the determination of arsenic, lead and copper that were originally published as Analytical Methods Committee Reports have been reviewed by the Sub-committee; that for arsenic (Gutzeit method) has been revised and approved for publication; those for copper and lead were considered to be out of date. The Sub-committee has been greatly assisted by the fundamental research done by Mr. Gorsuch at Harwell under the direction of Mr.Smales and is grateful to them also for their ready co-operation in helping to solve ad hoc problems in the course of the Sub- Committee’s work. DIRECT MICRO-DETERMINATION OF OXYGEN CONSTITUTION- D. W. Wilson, M.Sc., F.R.I.C. G. C. Ackroyd, B.Sc., A.R.I.C. P. R. W. Baker, B.Sc., A.R.I.C. Miss B. B. Bauminger, Ph.D., A.I.R.I., F.R.1 .C. W. T. Chambers, B.Sc., Ph.D., A.R.I.C. A. F. Colson, B.Sc., Ph.D., F.R.I.C. (C hairman) Miss M. Corner, B.Sc., F.R.I.C. R. R. Gordon, Ph.D. G. Ingram, A.R.I.C. F. J. McMurray F. H. Oliver H. J. Warlow C. Whalley, B.Sc., F.R.I.C. I N ORGANIC MATTER SUB-COMMITTEE Sir John Cass College (Department of Chemistry) D.S. I.R., Fuel Research Station Wellcome Research Laboratories Dunlop Research Centre British Rubber Producers’ Research Association Imperial Chemical Industries Ltd.(Alkali D.S.I.R., Chemical Research Labovatory National Coal Board, Central Research Estab- Courtaulds Ltd. Wellcome Chemical Works Parke, Davis & Co. Ltd. D.S.I.R., Fuel Research Station Lapovte Chemicals Ltd. Division) lishment TERMS OF REFERENCE-“TO investigate the Unterzaucher method, and its modifications, for the micro-determination of oxygen.’’ PROGRESS OF WORK- The Sub-committee is nearing the end of its second series of collaborative tests in which, as a result of the preliminary investigation of differences of technique during the first series, the experiments have beeLl designed with the object of reducing the “blank” values and of isolating possible sources of error. Because of the multiplicity of small modifications in technique that have been adopted from time to time by various laboratories, this second series of tests is very lengthy, but it is hoped that it will be possible to formulate a more closely defined technique as a result.TRACE ELEMENTS IN FERTILISERS AND CONSTITUTION- C. J. Regan, BSc., F.R.I.C. S. M. Boden, B.Sc., A.R.I.C. L. Brealey, BSc. S. G. Burgess, B.Sc., Ph.D., F.Inst.Pet., J. H. Hamence, M.Sc., Ph.D., F.R.I.C. R. l?. Milton, BSc., Ph.D., M.I.Biol., F.R.I.C. R. L. Mitchell, BSc., Ph.D., F.R.S.E., F.R.I.C. J. B. E. Patterson, M.Sc., F.R.I.C. (Chairman) N.Inst.S.P., F.R.I.C. FEEDING-STUFFS SUB-COMMITTEE Formerly Chemist-in-Chief, Loadon. County Council Ministry of Agriculture, Fisheries and Food, National Agricultural A dvisovy Service Boots Pure Drug Co.Lld. London County Council Public Analyst, Oficial Agricaltural Analyst and Consulting Chemist Analytical and Consulting Biochemist Macaulay Institute f o r Soil Research (Department of S9ectrochemistry) Ministry of Agriculture, Fishevies and Food, National Agricultural Advisory ServiceMay, 19581 REPORT O F THE ANALYTICAL METHODS COMMITTEE, 1957 267 TERMS OF REFERENCE-“TO devise appropriate methods of analysis (to be recommended for inclusion in the Regulations under the Fertilisers and Feeding Stuffs Act, 1926) for the determination of boron, cobalt, copper, fluorine, iodine, iron, magnesium, manganese, molybdenum, selenium and zinc, which can be expected to be present in fertilisers and. feeding stuffs.” PROGRESS OF W~ORK- The original Sub-committee was not dissolved immediately after the reorganisation of the Analytical Methods Committee because it was hoped that it would be possible to proceed with the programme of work, although members were finding it increasingly difficult to devote sufficient time to the amount of research that was involved. It was apparent that some of the methods that were being investigated by the Joint Committee on Methods for the Analysis of Trade Effluents might be applicable for fertilisers and feeding stuffs and it was decided to wait until these were published.Accordingly, after the appearance of these methods, during the past few months, the position was reviewed by the Analytical Methods Committee with the result that in September, 1957, the Sub- committee was reconstituted under the Chairmanship of Mr.C. J. Regan. Since then 3 meetings have been held and considerable progress has already been made; collaborative experimental work is being carried out to check the suitability of selected published methods (including a number of those recommended for trade effluents) and to make any modifications that may be necessary. VITAMINS The original Vitamins Sub-committee was dissolved at the time when the Analytical Methods Committee was reorganised, but the Panel on Vitamin E continues its investigations. Vitamin-E CONSTITUTIOX- A. L. Bacharach, MA., F.R.I.C. J. Green, B.Sc., Ph.D., F.R.I.C. V. H. Booth, Ph.D. I;. Brown, M.Sc., PI.1.D. A. R. Moss, B.Sc., Ph.D. H. N. Ridyard, B.Sc., A.K.C., F.R.I.C. P. W. Russell Eggitt, B.Sc., Ph.D., R.R.I.C. C.A. Shacklady, B.Sc., A.R.I.C. P. Stross, B.Sc. G. Walley, B.Sc., F.R.I.C. R. J. Ward, B.Sc., S.R.I.C. E. C. Wood, B.Sc., Ph.D., A.R.C.S., F.R.I.C. P. Harris, Ph.D.* (Chairmarz) (Honorary Technical Secvetary) Panel Consulti pig Chemist Vitamins Ltd. i?Wedical Research Council, Dun% hrutritional Laboratory Foot-azd-Mouth Disease Research Institute Roche Products Ltd. Research A ssociation of Byitisla Flour Millers Sfiillers Ltcl. J . Bibby & Sons Ltd. Bvitish Drug Houses Ltd. Unilever Ltd. Medical Research Council, Dunn Nutritional PLiblic A ~ a l y s t aqzd Consulting Chenzist Distillation Products Industries, Rochester, New Labovatory York, U.S.A. * Corresponding member. TERMS OF REFERENCE (OF ADVISORY PANEL)--I ‘To survey the methods already proposed for the estimation of Vitamin E and to recommend to the [Vitamins] Sub-committee a standard method or methods.” PROGRESS OF WORK- During the year the Panel has been engaged in working out the manipulative details of a procedure for the differential micro-analysis of tocopherols in natural oils and in complex samples, such as poultry meals.The method involves a paper-chromatographic separation of the tocopherols, after puri- fication, followed by their individual assay by a modification of the Emmerie-Engel colorimetric method. Although a considerable amount of manipulative skill is required, the Panel is of the opinion that the method has many advantages; it is hoped that the final recommendations will be published soon as a Report.268 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 [Vol.83 REPORT OF THE A.B.C.M. - S A C . ,JOINT COMMITTEE ON METHODS FOR THE ANALYSIS OF TRADE EFFLUENTS MAIN COMMITTEE CONSTITUTION- Representing the Associatio.lz of B v t i s h Chemical Manufacturers- H. N. Wilson, F.R.I.C.* Imperial Chemical Industuies Ltd. (Billingham J. G. Maltby, B.Sc., F.R.I.C.* Distillers Co. Ltd. F. G. Broughall, B.Sc., F.R.T.C. Midland T a r Distillers Lid. D. C. Garratt, Ph.D., D.Sc., F.R.I.C. Boots Pure Drug Co. Ltd. I. S. Wilson, M.Sc., Ph.D., A.R.I.C. Monsanto Chemicals Ltd. Representing the Society f o r ,4 nalyticul Chemistry- J. H. Hamence, M.Sc., Ph.D., F.R.I.C.8 Public Analyst, Oficial Agriczcltural Analyst and L. Klein, 1\9.Sc., Ph.D., M.Inst.S.P., F.R.I.C. Mersey River Board C.J. Regan, B.Sc., F.R.I.C. Formerly Chemist-in-Chief, London County J. G. Sherratt, BSc., F.R.I.C. Public Analyst and Consulting Analytical Chemist N. T. Wilson, F. K.I. C. Imperial Chemical Industries Ltd. (Alkali I<. A. Williams, B.Sc., Ph.D., A.Inst.P., M Inst.Pet , ( C h airman) Division) (Secretary) Consulting Chemist Council Division) Analytical and Consulting Chemist F.R.I.C. J. S. Evans Miss C. H. Tinker, B.Sc. , Ph.D., A.R.I.C." * Members of the Publications Sub-committee, to which J . B. Attrill, M.A., F.R.I.C., Editor of The Analyst, has been co-opted. TERMS OF REFERENCE-"TO devise and recommend methods of analysis as applied to trade effluents, specifying in each case their applicability and limitations, but not the interpretation of the results of such tests as would be used to decide on the quality of an effluent." PANEL 1 : ORGANIC MATTER-GEKERAL CONSTITUTION- Federation of British Indwtries Secretary to the Analytical Methods Committee C.J. Regan, B.Sc., F.K.I.C. G. S. Clements, A.R.C.S., F.R.I.C. W. M. Cameron, M.Inst.S.P., F.R.I.C. (Chairman) (Secretary) 'CV. T. Lockett, M.Sc. T. B. Moore, B.Sc. A. E. J. Pettet, B.A. I. S. Wilson, M.Sc., Ph.D., A.R.I.C. Miss C. H. Tinker, B.Sc., Ph.D., A.R.I.C. Formerly Chemist-in-Chief, London County Public Health Department, London County M a i n Drainage Department, Middlesex County Formerly of the M a i n Drainage Department, North Thames Gas Board D.S.I.R., Water Pollution Research Laboratory Monsanto Chemicals Ltd. Secretary to the Analytical Methods Committee COM'PZCZ'I Council Council Middlesex County Coumil PANEL 2 : METALLIC CONTAMINANTS CONSTITUTION- N.T. Wilkinson, F.R.I.C. R. Belcher, Ph.D., DSc., F.Inst.F., F.R.I.C. D. C. Garratt, Ph.D., D.Sc., F.R.I.C. J. H. Hamence, M.Sc., Ph.D., F.R.I.C. J. G. Sherratt, B.Sc., F.R.I.C. Miss C. H. Tinker, B.Sc., Ph.D., A.R.I.C. (Chairman) (Secretary) Imperial Chemical Industries Ltd. (Alkali University of Birmingham (Department of Boots Pure Drug Co. Ltd. Public Analyst, Oficial Agricultural Analyst and Public Analyst and Consulting Analytical Chemist Secretary to the Analytical Methods Committee Division) Chemistry) Consulting Chemist PANEL 3 : NON-ME:TALLIC CONTAMINANTS CONSTITUTION- F. G. Broughall, B.Sc., F.R.I.C. Midland Tar Distillers Ltd. (Chairman)May, 19581 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 269 Public Analyst and Oficial Agricultural Analyst; South Essex Waterworks Co.Wallace E Tiernan Ltd. W. G. Carey, F.R.I.C. G. U. Houghton, M.Sc., Ph.D., F.R.I.C. E. A. W. Whitlock, B.Sc., A.R.I.C. Consultant (Deputy: J. F. Malpas, B.Sc., A.R.I.C.) PANEL 4: PHYSICAL TESTS CONSTITUTION- J. G. Sherratt. BSc., F.R.I.C. L. Klein, M.Sc., Ph.D., M.Inst.S.P., F.H.I.C. G. A. Vaughan, F.R.I.C. K. A. Williams, B.Sc., Ph.D., A.1nst.P. Miss C . H. Tinker, B.Sc., Ph.D., A.R.I.C. Public Analyst and Consulting Analytical Chemist Mersey River Board Coal T a r Research Association Analytical and Consulting Chemist Secretary to the Analytical Methods Committee (Chairman) M.Inst.Pet., F.R.I.C. (Secretary) PROGRESS OF WORK- With the passing of the Rivers (Prevention of Pollution) Act in 1951 it became obvious that there should be accepted methods of analysis available in the event of dispute arising as to the composition of trade effluents.The Federation of British Industries Legislation Committee, therefore, asked the Association of British Chemical Manufacturers to investigate the position and to take the necessary steps to implement the work of approving or devising suitable methods of analysis. The result of the investigation was the formation of this Joint Committee of the Associa- tion and the Society for Analytical Chemistry, with the terms of reference quoted above, and the first meeting was held in March, 1954. In view of the urgent need for recommended methods it was decided that they should be published individually in The Analyst as soon as they were deemed satisfactory, rather than waiting until a complete collection had been made.Since this procedure would produce a haphazard collection of methods, it was also decided that they should subsequently be arranged and published as an integrated volume. Because the existing literature on the analysis of trade effluents was found to be scant, the Joint Committee’s task proved to be more arduous than had at first been envisaged and, although the majority of methods that have been recommended are based on existing ones, it was usually found necessary to make modifications to take into account the possibility of interference by a number of substances under very varying conditions. Consequently, it was imperative that before such modified methods could be finally recommended, they should be subjected to check tests by panel members.Some methods, on the other hand, had to be specially devised with a good deal of attendant experimental work. It is gratifying to report that, after just over 3& years of unremitting and intensive work by its four panels, the Joint Committee’s programme was completed at the end of 1957’. Practically all of the methods have been published in The AnaZyst since January, 1956. The remaining six methods have only just been completed and approved and are being included directly in the book, publication of which is expected before the end of April, 1958. They will, however, also appear in The Analyst. Mention has already been made in the General Review section of this Report of the research that is proceeding under the direction of Dr.Irving to devise a method that is sensitive enough for determining minute traces of silver in the presence of organic matter. It was considered advisable to include a method for silver because of its extreme toxicity to fish, although it is very unlikely that it will be a common contaminant in view of its economic value. Because many laboratories have to undertake the analysis of sewage effluents as well as trade wastes, cognisance has been taken of the methods recommended by the Ministry of Housing and Local Government in their publication “Methods of Chemical Analysis as Applied to Sewage and Sewage Effluents’’ (Second Edition, 1956) and, where possible, similar methods (modified as necessary to cover the special requirements for trade effluents) have been recommended.This need for uniformity is especially desirable where empirical methods are used and permission was, therefore, obtained from H.M. Stationery Office for reproduction in full of the methods for the determination of biochemical oxygen demand and of dissolved oxygen.270 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 REPORT OF THE P.S. - S.A.C. JOINT COMMITTEE ON METHODS OF ASSAY OF CRUDE DRUGS [Vol. 83 WAIN COMMITTEE CONSTITUTION- Representing the Pharmaceutical Society of Gveat Britain- K. R. Capper, Ph.D., B.Pharm., F.P.S., D.I.C. R. Higson, F.P.S. W. Mitchell, BSc., Ph.D., F.R.I.C. R. E. Stuckey, Ph.D., DSc., F.P.S., F.R.I.C.Representing the Society for Analytical Chemzstry- C. A. Johnson, BSc., B.Pharm., F.P.S., A.R.I.C. H. C. Macfarlane, A.R.T.C.S., F.R.I.C. D. Watt, F.P.S. D. C. Garratt, Ph.D., D.Sc., F.R.I.C. Representing the Tropical Products Institute-- A. J. Feuell, BSc., Ph.D., A.R.I.C. Pharmaceutical Society of Great Britain Ministry of Health, Supplies Division Staflord Allen & Sons Ltd. British Brug Houses Ltd. Boots Pure Drug Co. Ltd. Analytical and Consulting Chemist T. & H. Smith Ltd. Chairman of the Analytical Methods Committee (Chairman) (ex oficio) Tropical Products Institute Miss C. H. Tinker, BSc., Ph.D., A.R.I.C. (Secretary) TERMS OF REFERENCE--“TO prepare standard methods of assay of crude drugs and kindred materials.” PROGRESS OF WORK- As mentioned in the General Review section of this Report, this Joint Committee of the Pharmaceutical Society and the Society for Analytical Chemistry was set up in March, 1956.Five working panels have been appointed so far, and the progress of their work is reported individually below. Other panels will be appointed from time to time, when urgent problems present themselves. CONSTITUTION- PANEL 1 : Digitalis j!”~Z4?‘ea-CHEMICAL METHOD Professor H. Brindle, MSc., F.P.S., F.R.I.C. G. E. Foster, BSc., Ph.D., F.R.I.C. G. J. Rigby, MSc., Dip-Bact. J. M. Rowson, MSc., Ph.D., F.P.S. K. L. Smith, M.P.S. Professor J. P. Todd, Ph.D., F.P.S., F.R.I.C. Miss A. M. Parry, BSc. Emeritus Professor of Pharmacy, Univevsity of Weilcome Chemical Works University of Manchester (Department of Phar- Pharmaceutical Society of Great Britain Boots Pure Drug Co.Ltd. Royal College of Science aPzd Technology, Glasgow (School of Pharmacy) (Chairman) Manchester macy 1 (Secretary) TERMS OF REFERENCE-“TO investigate chemical methods for the assay of digitalis and its preparations and to attempt to correlate them with the biological method of assay.” PROGRESS OF WORK- As a preliminary to its work the Panel is comparing the figures for potency of the drug as obtained by standard biological methods with those obtained by chemical methods for the determination of the total active glycosides to find out whether any correlation exists. Collaborative tests have been carried out on two samples of digitalis leaf, one being a “good” leaf and the other a “poor” leaf (as determined by biological assay).Determinations of the glycoside content by several chemical methods have yielded good agreement between laboratories, but so far these show no correlation with the biological assay. As it appears that several glycosides are responsible for the total activity of the drug, and others are inactive, methods involving chromatographic separation and estimation of the total primary glycosides are now being studied. It is by no means certain that existing biological methods give a true indication of the potency of the leaf and it is hoped to arrange for information on this point to be obtained from clinical tests, and by comparison of different methods of biological assay.May, 19581 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 271 The Panel is most grateful to Messrs.F. Hoffmann - La Roche & Co. Ltd. A.G. for a gift of 10 g of pure digitoxin to be used as a reference standard a t a later stage in the work. CONSTITUTION- PANEL 2 : CAPSICUM-CAPSAICIN CONTENT H. B. Heath, M.B.E., B.Pharm., F.P.S. E. A. Elsbury, F.R.I.C. C . A, MacDonald, B.Sc., F.R.I.C. G. R. A. Short, F.P.S. D. 0. Singleton, B.Sc. Miss A. M. Parry, B.Sc. Staflord Allen & Sons Ltd. Parke, Davis G. Go. Ltd. Evans Biological Institute W . J . Bush & Co. Ltd. Beecham Maclean Ltd. (Chairman) Miss B. M. Luckett w. J . ~ u ~ h tj, co. Lta. (Secretary) TERMS OF REFERENCE-~TO investigate methods of assay of capsicum and capsicum products with particular reference to the determination of the capsaicin content .” PROGRESS OF WORK- Several published methods have been critically examined and after an appreciable amount of collaborative work considerable progress has been made towards the establishment of a satisfactory method of determining the capsaicin content of chillies and also of oleoresins prepared from them.This consists in two alternative procedures for the isolation of capsaicin, one chromatographic and the other by alkali extraction, after which the capsaicin content is calculated directly from the extinction value. A confirmatory colorimetric method has, after considerable modification, also been found to be acceptable. It had been hoped that this method would give results sufficiently accurate to quote an extinction value for the coloured capsaicin complex, but this has not proved to be so and it is, therefore, necessary to prepare a standard absorption curve at the same time as the test.The possibility of finding an alternative synthetic standard to avoid constant handling of capsaicin is still under consideration. Future work will be concerned with the application of the methods to paprika, tinctures and other preparations containing capsaicin. CONSTITUTION- PANEL 3 : ANTHRAQUINONE DRUGS J. M. Rowson, M.Sc., Ph.D., F.P.S. J . W. Fairbairn, B.Sc., Ph.D., F.P.S., F.L.S. Pharmaceutical Society of Great Britain University of London, School of Pharmacy (Chairman) F.R.I.C. C. W. H. A. Johnson, B.Sc., B.Pharm., F.P.S., A.R.I.C. Mitchell, B.Sc., Ph.D., F.R.I.C. A. Ryan, B.Sc., F.R.I.C. Boots Pure Drug Go. Ltd. Stafford Allen tj, Sons Ltd. Westminster Laboratories Ltd.Allen G. Hanburys Ltd. W. Smith, B.Sc., F.R.I.C. Miss A. M. Parry, B.Sc. (Secretary) TERMS OF REFERENCE-“TO investigate methods for estimating the purgative activity of drugs and preparations of drugs containing anthraquinone derivatives with a view to recommending standard methods of assay.” PROGRESS OF WORK- Collaborative work is being carried out on samples of both Alexandrian and Tinnevelly senna pod and a comparison is being made between the sennosides content found by chemical methods and the activity determined by biological assay. PANEL 4: RAUWOLFIA CONSTITUTION- C. A. Johnson, B.Sc., B.Pharm., F.P.S., A.R.I.C. T. Davies, B.Sc., A.R.I.C. F. G. Farrell, B.Pharm., M.P.S., A.R.I.C. J. J. Lewis, M.Sc., F.P.S. A. W. Peacock, B.Pharm., F.P.S. Miss A.M. Parry, B.Sc. Boots Pure Drug Co. Ltd. CIBA Laboratories Ltd. Pharmaceutical Society of Great Britain University of Glasgow (Department of Materia Riker Laboratories Ltd. (Chairman) Medica and Therapeutics) (Secretary)272 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 [Vol. 83 TERMS OF REFERENCE-"TO investigate methods of assay for rauwolfia and its preparations with particular regard to the content of reserpine and related alkaloids." PROGRESS OF WORK- The main problems confronting the Panel in formulating a suitable assay procedure are the considerable number of alkaloids present in rauwolfia as well as the large number of species of rauwolfia in which distribution of the alkaloids varies. The first year's work has been devoted to the study of RauuoZJia serpentina, which is one of the major commercial sources and for which there is a method published in the B.P.Codex, 1954. It has been decided to seek to establish a method indicating the com- mercial value of the sample as a source of reserpine, rather than to devise a method that would show correlation with the biological activity of the whole root. Two approaches to the problem have so far been considered, both of which are based on published methods. Good progress is being made in the investigations on one of these, a colorimetric method, which it is hoped may prove suitable for recommendation while investigations into a more specific and fundamental method continue. Preliminary exploratory work on the ultra-violet absorption characteristics of reserpine and rescinnamine and of the acids produced as decomposition products showed the second method to be basically unsound because of the rapid deterioration of one of the acids when exposed to light.The cause of this deterioration is now being studied and it is hoped that valuable information may emerge regarding the mechanics of the reaction. The Panel is grateful to Messrs. CIBA Laboratories Ltd. and Messrs. Riker Laboratories Ltd. for generous gifts of samples of pure alkaloids and of RauwoZjia serpentina for use in the Panel's work. PANEL 5 : LONCHOCARPUS AND DERRIS CONSTITUTION- R. F. Phipers, BSc., Ph.D. R. Buckley, B.Sc., A.R.I.C. J. A. Dawson, B.Sc., A.R. I.C. W. E. Drinkwater, F.R.I.C. R. V. Foster, M.Sc., A.R.I.C. S. C. Jolly, B.Pharm., B.Sc., F.P.S., A.R.I.C.J. T. Martin, B.Sc., D.Sc., F.R.I.C. D. V. Richmond, B.Sc. (Chairman) W. M. Seaber, B.Sc., F.R.I.C. F. H. Tresadern Miss A. M. Parry, B.Sc. (Secretary) The Cooper Technical Bureau Plant Protection Ltd. Tropical Products Institute Boots Pure Drug Co. Ltd. The Cooper Technical Bureau Pharmaceutical Society of Great Britain University of Bristol (Long Ashton Research University of Bristol (Long Ashton Research Salamon & Seaber Stafford Allen & Sons Ltd. Station) Station) TERMS OF REFERENCE-"TO investigate methods of assay of derris, lonchocarpus and their preparations, with particular reference to the determination of their rotenone content ," PROGRESS OF WORK- At the Panel's first meeting in July, 1957, it was agreed that, although methods exist for use in trade transactions in derris and lonchocarpus, the agreement between different analysts' results is unsatisfactory.No collaborative work had been done on the latter, which is now the main material of commerce and there is a need for a reference method for determining the true rotenone content of the sample. Collaborative work on gravimetric methods for the determination of rotenone has begun.May, 19581 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 -- L11,768 -_I 273 Current Account . . . . 4493 - 142 In Hand .. .. .. - 11,493 L9861 L11,768 - APPENDIX I THE SOCIETY FOR ANALYTICAL CHEMISTRY ANALYTICAL METHODS TRUST ACCOUNTS FOR THE YEAR ENDED OCTOBER 3 1 s ~ , 1957 Income and Expenditure Account for the Y e a r Ended October 31st.1957 1956 L L 630 2274 81 168 62 26 21 83 3345 - 525 2634 ,56504 - , 5 L Rent, Light, Heat and Telephone . . . . 289 Salaries . . .. . . 2630 Office Equipment . . 487 Printing and Stationery 184 Travelling Expenses . . 20 Expenses of Meetings . . 107 Audit Fee . . . . 21 Postage and Petty Ex- penses . . . . . . 78 Scholarship Grant . . 958 Excess of Income over Expenditure for the year ended October 31st, 1957, transferred to Accumulated Fund 1164 L5938 - 3816 __I 1956 , 5 L 150 6344 6494 __ 7 2 1 10 - - ,56504 - Accumulated Fund 1956 1956 jt: Legal Expenses in connection with 93 formation of the Trust . . .. Balance carried to Balance Sheet . . 10,854 L - 9690 l9783 - L10,854 - L L Subscriptions from In- dustry as a result of Appeal : Received in 1955 for 1957... . . . 150 Received during 1957 5750 - 5900 Interest from Invest- ments : Received gross . . 7 Received net . . 2 Income Tax re- coverable . . .. 1 - 10 28 Bank Deposit Interest . . ,55938 - L 4 6779 Balance a t October 31st, 1956 . . 9690 Analytical Chemistry Research Balance a t October 31st, 1955 3 70 transferred . . .. .. Excess of Income over Expenditure for the year ended October 31st, 2634 1957 . . . . . . . . 1164 Fund- - ,59783 - L 10,854 I L9861 -[Vol. 83 274 REPORT OF THE ANALYTICAL METHODS COMMITTEE, 1957 Report of the Auditovs to the Trustees of The Society for Analytical Chemistry Analytical Methods Trust Fund We have examined the above Balance Sheet which in our opinion gives a true and fair view of the state of affairs of the Trust a t 31st October, 1957. 10 New Court, Lincoln’s Inn, LONDON, W.C.2. 4th March, 1958. (Signed) RIDLEY, HESLOP & SAIKER, Chartered Accountants, Auditors. Schedule of Investments at October 31st, 1957 Market Income Value Received Nominal Amount cost 31.10.57 Gross Ceylon Government 3:y0 Stock, 1959 . . . . 100 61 79 3 3+y0 Conversion Stock . . .. .. .. 100 83 63 4 3&y0 War Stock . . .. .. .. . . 100 100 61 3 L244 k203 L l O _____ --- - --- APPENDIX I1 SUBSCRIBERS TO THE TRUST FUND DURING 1957 Albright & Wilson Ltd. The Associated Ethyl Company Ltd. Bakelite Ltd. Baker Perkins Ltd. J. Bibby & Sons Ltd. A. Boake, Roberts & Co. Ltd. Boots Pure Drug Co. Ltd. Borax Consolidated Ltd. The British Aluminium Co. Ltd. The British Arkady Co. Ltd. British Celanese Ltd. The British Drug Houses Ltd. British Glues & Chemicals Ltd. Brotherton & Co. Ltd. Cadbury Brothers Ltd. Central Electricity Authority The Distillers Company Ltd. Dunlop Research Centre Esso Development Co. Ltd. Ferranti Ltd. Fisons Ltd. Glaxo Laboratories Ltd. Arthur Guinness, Son & Co. (Park Royal) Ltd. H. J. Heinz Ltd. Hopkin & Williams Ltd. Huntley & Palmers Ltd. Imperial Chemical Industries Ltd. Laporte Chemicals Ltd. J. Lyons & Co. Ltd. Macfarlane, Lang & Co. Ltd. John Mackintosh & Sons Ltd. Marmite Ltd. May & Baker Ltd. The Metal Box Company Ltd. The Millers’ Mutual Association Monsanto Chemicals Ltd. 0x0 Ltd. Peek, Frean & Co. Ltd. Procea Products Ltd. Reckitt & Colman Ltd. Research Laboratories, General Electric Co. Rowntree & Co. Ltd. “Shell” Research Ltd. Stafford Allen & Sons, Ltd. John & E. Sturge Ltd. Tate & Lyle Ltd. Unilever Ltd. Vitamins Ltd. Weston Research Laboratories Ltd. (formerly Allied Bakeries Research Laboratories Ltd.) Ltd.

ISSN:0003-2654    

DOI:10.1039/AN9588300262

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

May, 19581 LINSTEAD SCIENCE AND POLITICS 275 The Fifth Bernard Dyer Memorial Lecture Science and Politics BY SIR HUGH LINSTEAD, O.B.E., LL.D., F.P.S., M.P. (Deliveyed after the Annuat General Meeting of the Society, February 26th, 1958) To be asked to give the fifth Bernard Dyer Memorial Lecture is an honour I greatly appreciate. The purpose of the lecture is primarily to do honour to the memory of the life and work of Bernard Dyer, one of the founders of this Society. As the years pass the number of those who knew him will become smaller and there will be fewer additions to be made to the known details of his life. It is therefore fortunate that in the first lecture Sir John Russell recorded so living a picture of him, from which he emerges as one of the great individualists of the period when chemistry in this country was taking shape as an organised profession.Such links as I can claim with him are through the Pharmaceutical Society, where he studied in the laboratory that had once been Hofman’s, and through the City of London School. Here, incredibly, he was taught chemistry in 1871 by the same Isaac Scarf who taught me in 1914, forty-three years later. I met him personally once only, but he remains in my memory as a twin figure with that other individualist of the same epoch, Henry Armstrong. The two main interests in my life have been pharmacy and politics and I have chosen as the title of this lecture “Science and Politics.” I want in it to discuss the relation between those two disciplines and, if I can, to define the place that the scientist has to fill in politics.It will be useful first of all to look at examples of the sort of scientific problems that impinge most closely on politics. These are problems about which the scientist is equipped to speak authoritatively and yet he often finds that his answer is not the final one. If one were to list those likely to have the most profound effect upon humanity during the next century they would fall into two rough groups. There are the old biological problems that have been with mankind throughout its struggling history-the relation between populations and foodstuffs; the preservation of natural resources ; the conservation and utilisation of water supplies. And then there are those more recent challenges that at present outstrip our ability to regulate them-nuclear fission; penetration into outer space; and all that is implied in the term “brain-washing.” Each one of these, the old and the new, represents a field in which science and politics are inextricably mixed and to which both scientist and politician have contributions to make, although differing both in form and in content.In reviewing these problems the scientist’s approach is simple and direct. The politician’s, for valid reasons that will appear in due course, hesitating, fumbling, circumambulant. I speak here of the politician in a parlia- mentary democracy. The scientist’s method in inductive: here are the facts, where do they lead me? But they are fundamentally different in so far as there always intrudes into the political approach the incalculable element of the reactions of human beings.One or two examples will illustrate this. Sir Harold Hartley, in the first Graham Clark Memorial Lecture before the Institution of Civil Engineers in May, 1955, thus sums up the achievement of the Tennessee Valley scheme with its 27 dams and reservoirs controlling a river basin of 40,000 square miles: “The reservoirs provide 11$ million acre-feet of storage for flood control at the beginning of the flood season and have saved an immense amount of flood damage each year. Six million acres of rich bottomland is protected in this way. The replanting of the slopes has stopped soil erosion, has made the muddy streams clear again and delayed the silting of the reservoirs. T.V.A. brought new life into a depressed area and did much to raise its standard of living.” This is an objective scientific assessment of the benefits that have (almost literally) flowed from this great federal project.That was what the scientists promised and what they gave to the community. Yet what were the political reactions that it provoked? Opposition from the outset that was none the less fierce because at that period of agonising depression in the American economy it had to be under cover. And opposition subsequently There are fewer such men to-day and we are the poorer. The politician proceeds deductively: there is the goal, how do I get to i t ?276 LINSTEAD : SCIENCE AND POLITICS [Vol. 83 with the objective that there should never again be such a dynamic use of combined national resources unless indeed the country were to be driven to initiate public works by reason of a comparable slump to that of 1830.Why this political opposition to a great economic achievement? It was not simply that private vested interests moved in again once the emergency was past. Opposition to Roosevelt’s New Deal was based upon deep conviction. If we remove the same problem to another comparable area, the Danube Basin, we find F. A. Hayek in “The Road to Serfdom” maintaining that “one cannot create a kind of Tennessee Valley Authority for the Danube Basin without thereby determining beforehand for many years to come the relative rate of progress of the different ra.ces inhabiting this area, or without subordinating all their individual aspirations or wishes to this task.. . . Though there are no doubt many people who honestly believe that if they were allowed to handle the job they would be able to settle all these problems justly and impartially, and who would be genuinely surprised to find suspicion and hatred turning against them, they would probably be the first to apply force when those whom they mean to benefit prove recalcitrant, and to show themselves quite ruthless in coercing people in what is presumed to be their own interests.” You may feel that a Macedonian or Bulgarian peasant would willingly sacrifice some modicum of such liberty as poverty allots to him in return for a plenteous supply of water and power. You may feel that the choice in such cases often lies between collective action and no action at all and that Hayek’s arguments have no roots in reality.Nevertheless, they represent political ideals deeply andl sincerely held. They have no relevance to the scientific balance sheet of schemes such a s the T.V.A. or the Danube Basin: that balance is measured in gallons and kilowatts. But a politician can ignore ideals such as Hayek’s only at his peril. A neat example of the interplay of politics and scientific irrigation schemes is mentioned in “Report of the Royal Commission on East Africa” (Cmd. 9475 of 1955). The Com- mission point out that “throughout East Africa the lack of discovered or developed water supplies is a major factor in preventing tlhe use of otherwise productive resources.” They recognise that some part of the limited finance of the governments of the East African territories should be devoted to meeting this basic need.What could be more straight- forwardly obvious than that this money should be used on schemes selected by the Govern- ment for priority? But the Commission warn against such utilisation of government water- development agencies operating at or below cost. Experience in Kenya has shown that once government shows itself prepared to move into this field and offer its services on what are in effect subsidised terms, numbers of farmers forthwith postpone embarking on water development privately and wait for their turn in the government scheme. The result is likely to be that the amount of water development may prove to be less than if the government had never moved in at all ! .. . But perhaps this is not politics but simply human nature ! The reverse process-politics driving science-is vividly illustrated in Israel. The Proclamation setting up the new State of Israel in 1948 declared that Israel “will be open to the immigration of Jews from all countries of their dispersion.” No Jew who reached Israel could be turned away, and since mid-1948 nearly 900,000 Jewish immigrants have been received. The total population, Jews, non-Jews and immigrants, at the end of 1956 was about 1,800,000. So in ten years the population had doubled. Politically, that meant that every natural resource of the country had to be developed vigorously. Scientifically, that largely meant the development of water resources. From Dan to Beersheba the country is green.From Beersheba to Eilath on the Red Sea there is brown desert, the Negev. You fly south from Tel-Aviv over a landscape of the moon. Through this the Israelis have driven a monumental motor road and at rare intervals in this barren desolation groups of bungalo.ws can be picked out, each with its minute miracle of green where the desert is being compelled to flower. Israel’s irrigated area has increased from 300,000 dunams in 194849 to 1,000,000 in 1955-56. These achievements are spectacular, and one cannot but observe the almost complete absence of similar initiative by Egypt in Sinai and the Gaza strip and by Jordan along her long frontier with Israel. As I have said, political necessity has forced irrigation on Israel. But even there politics has at the same time compelled a truncated scheme.There can be no region where a comprehensive water con- servation scheme would be more rewarding than in the whole of this part of the Middle East. It should include Lebanon and Syria in the north, Israel and Jordan in the centre and Egypt (A dunam is a quarter of an acre.)May, 19581 LINSTEAD : SCIENCE AND POLITICS 277 and Saudi Arabia in the south. But one has no sooner named the countries concerned than politics rears its head. The feud between Arab and Jew is paralleled only by that between Muslim and Hindu, and makes any large scale co-operative enterprise a matter of immense difficulty even were the atmosphere not darkened by the aftermath of the Sinai campaign. These examples could be multiplied many times to show how politics blunts the edge of science.Take another of these fundamental biological problems where science and politics interlock-the reactions between population and food supply. The name linked with the first discussion of this problem in our own country and our own times is, of course, that of the Rev. Thomas Robert Malthus, curate of Albury in Surrey, who, in 1798, published his “Essay on the Principle of Population.” He argued that population would soon increase beyond the means of subsistence and that checks on this increase are necessary. The essay aroused a storm of controversy and, in his second edition in 1803, Malthus modified some of his conclusions. The problem remains a cardinal one in Africa and in Asia to-day. There are still some who accept the Malthusian doctrine.But the better view seems now to be that an increase in population provides by its own labour the food and other resources it needs. It is a problem of fundamental importance for the European settlers in Africa. They are, of course, fearful of the consequences of a steady increase of the African population and this fear evidently coloured their evidence to the Royal Commission to which I have already referred, evidence that seems to have been based on the belief that the Africans were increasing at an annual rate of 2 per cent. and would double their numbers in thirty-five years. To what was essentially a political approach the Commission opposed a scientific one. They undertook a statistical examination of the available census figures and reported that “apprehensions concerning an unduly rapid rate of population growth are not supported by the statistical material available; there is no evidence that the African population as a whole is increasing at an annual rate of 2 per cent.; [although] there has been an upward movement in the rate of natural increase.” But although science speaks here with an authoritative voice and has figures on its side, no politician would be so simple as to imagine that that disposes of the affair.The fear of the European that he will some day be drowned in a sea of Africans is too deeply planted to be eradicated by statistics, however authoritative. As examples of ways in which politics and science may interact, I have chosen two -conservation of water and the relation between population and food-where science may claim to be on the side of the angels, wherever that may leave politics.I want by way of contrast to take an example where science, unless it shows high responsibility, can all too easily serve the devil. It is what we to-day crudely call “brain-washing,” and it takes us back to Pavlov and his dogs. Pavlov knew that when a hungry dog saw food it would salivate. A bell was rung at the same time as he fed his dogs and he found, after many repetitions, that they would salivate at the sound of the bell even in the absence of food. From this Pavlov developed the theory of the conditioned reflex, which explains learning as the building up in the individual of a jig-saw of conditioned reflexes each one based on a different stimulus.It is this process, recognised for half a century and mildly applied in such persuasive operations as advertising, that has now been conscripted into the service of Soviet Russia. Dr. Joost Meerloo, formerly Chief of the Psychological Department of the Dutch armed forces and now of Columbia University, New York, describes two institutions, part of the Moscow Academy of Science, that are dedicated to the political application of the Pavlov theory. He says, “They are under orders to emphasise the purely mechanical aspects of Pavlov’s findings. Such a theoretical view can reduce all human emotions to a simple, mechanistic system of conditioned reflexes. Both organisations are control agencies dealing with research problems and the scientists who work on them explore the ways in which man can theoretically be conditioned and trained as animals are.” Now it so happens that in this current month, Express, a French weekly, has been publishing (January 31st, February 6th and February 13th) an account of the experiences of a Hungarian, Lajos Ruff, aged 26, during his “brain-washing” by the political police in Buda-Pest for six weeks until he was released during the abortive revolution of October, 1956.It reads like a fairy story and Ruff may be the only witness available to testify to its truth. ,4nd yet I have a firm feeling that his tale is in the main true. The headquarters of the political police in Buda-Pest, Andrassy-utca 60, had an unsavoury reputation when I was278 LINSTEAD SCIENCE AND POLITICS [Vol. 83 there in 1947.I can remember also all too well an unhappy woman who came to see me at the Bristol Hotel with a tale of the condition in which she found her husband when she was allowed to visit him. There was again the experience of the father of a Hungarian friend of mine now in England, who was frequently visited by the political police at all hours of the day or night, taken away to the commandatura and detained there, ostensibly for interrogation but in fact to break his spirit. I had the privilege of spending a full day with him at Esztergom and I subsequently read the verbatim account of his trial. The Mindszenty who gave evidence at the trial was no longer the Mindszenty of Esztergom. And so I am prepared to believe the substance of what Ruff has to say. This, remember, is not the Arabian Nights.It is Europe in 1956. He was confined in a comfortable cell, which he soon began to visualise as “the magic room,” where one was free from all responsibility for decisions of any kind. Here he was first conditioned to mistrust himself. He was put to sleep. When he was woken up a kindly doctor would accuse him of attempted suicide. He would deny it only to find a cut artery bandaged up and blood on the floor. Or he would be accused of trying to strangle himself. A scarf would be found in his bed and his neck would be severely bruised. Then he was conditioned to believe that he could never escape. A ray of light was projected into his cell. But wherever he stood or sat or lay it crept slowly towards him. Finally after some days he was convinced he could not escape it and so he flung himself into it, only to find it harmless and to sink into an exhausted sleep. He was given perpetual cinema shows so that finally the frontiers between the real and the imaginary lost their significance.“I cut myself off from real life,” he says, “I had no decisions to make. I had no need to think. . . .” Even when the door of his cell was left open, he had no desire to escape. It was at this stage that he began to reveal the names of friends. It had ceased to be a matter of any reality or meaning to him that they existed or what might happen to them as the result of his disclosures. One final quotation- “To the extent that I lost confidence in myself, my confidence in the doctor increased. . . . I was not far from the state in which one is said to say no matter what to a tribunal which seems to you unreal so that you can get back more quickly to the sole reality that matters, the safe world of the magic room.” Well, there it is: civilisation in the year of Our Lord 1956.Scientists may say hard things at times about politicians. Let them reflect with some humility on this prostitution of science by scientists as well as by politicians. I want to take briefly one other example of a field where politics and science interlock all too closely. There is no need to go over the familiar arguments in detail-the immense potential benefits to mankind and the immense dangers. What is of interest for our argument is that you have here a fundamental scientific discovery that has been hurled into the political arena and become the centre of acute controversy.Members of Parliament are willy-nilly having to equip themselves with all the vocabulary of atomic science and the Prime Minister is rapidly qualifying himself for a senior teaching post in a university department of nucleatr physics. It is right that there should be this intense concern. What, however, is less laudable is the manner in which scientific facts have become twisted and distorted to provide material for purely party debates. We know that there are dangers from radioactive fall-out. We do not know accurately what those dangers may be. In such circumstances it is surely not for responsible persons to exaggerate those dangers without information and to alarm the community by partisan statements.What is needed is the fullest information from the most reliable sources to enable some judgment to be formed of how far the danger extends and what are the risks we are running. That course was eventually followed and atn almost historic report on the hazards of radio- active fall-out was brought out by a committee of the Medical Research Council under the chairmanship of Sir Harold Himsworth. But not before h a m had been done by the irresponsible use of partial and distorted information for political purposes. I am not concerned to-night to defend or attack the two-party system as it has developed in this country. It has much to be said in its favour. Many of my French friends-some of them ex- perienced members of the Assemblke Nationale-speak enviously of the strength that the system And then there is Cardinal Mindszenty. He was told to keep away from it as it would damage him.That is the field of nuclear energy.May, 19581 LINSTEAD : SCIENCE AND POLITICS 279 ensures for the government of the day. And I am certainly no advocate of a multi-party system nor of that will-o’-the-wisp a national government of coalition. But I must acknow- ledge that with its many advantages the two-party system has one grave disadvantage. According to it, the duty of the Government is to govern and the duty of the Opposition is to oppose. And that latter duty can be in some circumstances interpreted to justify the use of alrnost any means to embarrass or discredit the Government. Both the parties are open equally to this criticism.At times when feeling is running high it is all too easy for partisanship to outrun discretion and responsibility. It is such occasions-perhaps they occur too often-that get politics and the politician a bad name, particularly when it is possible to compare side by side the reactions to the same problem among scientists and among politicians. Yet, broadly speaking, I am here to defend the politician in spite of actions that may from time to time appear to be indefensible in his behaviour or his decisions. Politics, in its parliamentary context, has been defined as “the infinite adventure of governing men.” A French professor to whom I shall refer again, Gustav Le Bon, once wrote that governing men is a very difficult matter and that the most a statesman can hope to achieve is “not to be too much governed by them.” Be that as it may, someone must attempt to govern and in a parliamentary democracy this implies the consent of the governed and therefore that he who governs shall conform to the only conditions-however distasteful to him-that may permit him to do so. Before the United States could be brought into the second World War, the President had slowly to ripen public opinion over two years.One of the major factors in the failure of the Suez operation was the impossibility, for security reasons, of taking any preliminary steps at all to prepare public opinion in this country for such drastic action by our forces. Instead of being prepared, the public was stunned. There may be the clearest of reasons for some line of action that can be demonstrated scientifically and yet it may be politically entirely un- realistic.The economic advantages of a union between the two parts of Ireland are no doubt very great. Yet he would be a brave man who would dare even to suggest at a public meeting in Ballymena or Portrush that they might conceivably be worth discussion. I do not doubt that it can be persuasively shown that Israel is not a viable economic unit. But I have equally no doubt that nothing short of physical extinction will prevent that country from developing and improving its living standards steadily. There it is not mathematics that provides the answer. The politician must, of course, use science. But ultimately his decisions are taken by that sixth sense, Ze sens du $.possible, the sum of all the factors, material, human and moral that bear on a situation. To underline the cardinal necessity of always carrying the people with you in any major political change may suggest that a Member of Parliament should be merely the delegate of his electors.But this ought never to be so. Edmund Burke stated memorably the relationship between a Member of Parliament and his constituents in his speech to the electors of Bristol after the declaration of the poll on November 3rd, 1774. “Certainly, gentlemen,” he said, “it ought to be the happiness and glory of a repre- sentative to live in the strictest union, the closest correspondence, and the most unreserved communication with his constituents. Their wishes ought to have great weight with him; their opinions high respect ; their business unremitted attention.. . . But his unbiased opinion, his mature judgment, his enlightened conscience, he ought not to sacrifice to you, or to any set of men living. These he does not derive from your pleasure; no, nor from the Law and the constitution. They are a trust from Providence, for the abuse of which he is deeply answerable. Your representative owes you, not his industry alone, but his judgment; and he betrays, instead of serving you, if he sacrifices it to your opinion.” Nevertheless, the greatest and most independent of statesmen is never a completely free agent to do precisely what he believes should be done at the time when he believes it should be done. He must temper his actions by regarding the state of public opinion.Roosevelt knew it ; Baldwin found it out ; it was tragically brought home to Sir Anthony Eden. Gustav Le Bon, to whom I have referred, wrote a t the end of the last century a remarkable book, which is too little known. It is available in English as “The Crowd.” By reference mainly to French examples, he attempts an analysis of the motives and ways of behaviour of men and women when they lose their identities as the result of becoming, however temporarily, members of a crowd. “There is He must “carry the people with him.” Politics is not mathematics. It is will power. He called it “La Psychologie des Foules.”280 LINSTEAD : SCIENCE AND POLITICS [Vol. 83 nothing so queer as folk” and Le Bon lays bare the peculiar queerness of folk in the mass.Writing more than sixty years ago, he draws attention to the destruction of the religious, political and social beliefs in which all the elements of our civilisation are rooted. “The ideas of the past,” he says, “although hall‘ destroyed, being still very powerful, and the ideas which are to replace them being still in process of formation, the modern age represents a period of transition and anarchy. . . . The entry of the popular classes into political life- that is to say, in reality, their progressive transformation into governing classes-is one of the most striking characteristics of our epoch of transition.” Then, by way of an analysis of the characteristics of what he calls a psychological crowd -a crowd in which the individual has come to surrender his personality-he explains the effect on politics and government of this shift in the balance of power from the traditional governing classes to the new governing classes.From this Le Bon demonstrates that crowds are not to be influenced by reasoning. They think in images and are specially impressed by the marvellous. Among their charac- teristics he notes impulsiveness, irritability and the absence of judgment and of the critical spirit. This being the condition of human beings when they are assembled in the particular kind of crowd that we recognise as a nation or other political community, he goes on to show that the art of governing them cannot be based primarily on appealing to their reason. For good or for bad, says Le Bon, crowds are led by affirmation without proof, by repetition and by contagion.“To know the art of impressing the imagination of crowds is to know at the same time the art of governing them.” “All the great statesmen of every age and every country, including the most absolut e despots, have regarded the popular imagination as the basis of their power, and they have never attempted to govern in opposition to it. ‘It was by becoming a Catholic,’ said Napoleon to the Council of State, ‘that I terminated the Vend6en war, by becoming an Ultramontane that I won over the Italian priests, and had I to govern a nation of Jews I would rebuild Solomon’s temple’.” And a final quotation : “A knowledge of the psychology of crowds,” says Le Bon, “is to-day the last resource of the statesman who wishes, not to govern theim-that is becoming a very difficult matter-but at any rate not to be too much governed by them.” The developments studied by Le Bon were reviewed in 1927 by another Frenchman, Julien Benda, in a book he called “La Trahison des CZercs”-“Betrayed by the Intellectuals,” we might translate it.It was a book that did not attain fame until it was reprinted in 1947 at the end of the second World War. Benda’s conclusion-that humanity had been let down by those who should have been its intellectual saviours-seemed to have been tragically reinforced by the behaviour of many of the leaders of French thought during 1939 and 1940 and especially during the German occupation. In his book Benda proclaimed the duty of the intellectuals in every community to be to defend eternal and objective values-reason, for example, and justice. Surveying the development of humainity from the same viewpoint as Le Bon, Benda suggests that there was a time when human beings could be regarded as forming two groups.There was the mass of the people held together by such forces as membership of the same country or of the same class. And there was the small intellectual class or corporation, which understood and opposed the inadequacy and parochialism of such a limited conception of human association. These latter were the teachers, the artists, the philosophers who were seeking to discover the soul of Europe, something that would rise above nationality. Among other means to their ends they were developing a universal language-Latin-and standards of thought and behaviour based upon thle teachings of the Greeks and of Christ.Benda considered that by the time he was writing this corporation of the 6lite had sold out to the masses. It no longer opposed their purely realistic and material ideas. Indeed, it had taken them over and glorified them. “To-day,” he says, “the game is over. The layman has won. . . . Indeed, all humanity has become lay, including the intellectuals.” By “lay” he means materialistic and it is this surrender to the whims of the masses that leads him to accuse the intellectuals of trahison-treachery, betrayal. It is the writers-especially the journalists-who come under Benda’s lash. The scientist escapes. He escapes largely because he has so far been uncommitted. But the scientist has all the same been increasingly sensitive to his lack of authority in the political application of his discoveries and there is an increasing demand among scientists that they shall have an effective voice in the practical conduct of political affairs.They are, in fact, poised for the decisive move from the objective field of science to the subjective field of politics. AndMay, 19581 LINSTEAD : SCIENCE AND POLITICS 281 I want to-night to raise at least one voice against what may well be a tragic decision if it were acted upon by any large group of scientists. In to-day’s world-a world of propaganda, cold war, mass hypnotism by broadcasting and by newspapers with vast circulations-truth is too easily a casualty. If humanity is to be deprived of objective standards because the scientist has come down from his uncommitted heights to take sides in the party-political battle, then humanity will be immeasurably the poorer. To say that the scientist should stand aloof from the party-political contest is not to exclude him from politics in its fullest and best sense.He has political duties of the first importance that no one else can perform. The first is to ensure that his discoveries are clearly presented to the public. There is an eager audience waiting to be informed about the significance of scientific developments. There is an immense diversity of means whereby these things can be brought to the eyes and ears of the men, women and children who want to know about them. But just because these means are so potent and so pervasive there is a great responsibility upon those who control them and use them to ensure that, so far as is humanly possible, they are used in the service only of truth as that is understood by science.This responsibility rests with particular weight on the shoulders of some individuals. The scientific correspondents of great newspapers, those who have the direction of scientific programmes on the radio, those who teach science in schools and universities, cannot escape from it. A special duty rests upon some of our scientific bodies both in specialised fields and generally. The British Association for the Advancement of Science has for long recog- nised the need in this field and has recently studied ways by which, at its annual meetings and otherwise, it can disseminate still more widely a knowledge of the contributions science is making to human progress. It grows harder as science expands and deepens.It faces the peculiar difficulty that the mass of people, as Le Bon so clearly showed, are neither able to follow a reasoned argument nor wish to do so. They think in images and are at the mercy of someone who can put persuasively and vividly his story to them. This, then, emphasises the need for, and the heavy responsibility of, scientists who are willing to assume the r6le of interpreters of science to the public. They can influence public opinion for good or for bad by a single broadcast or a single newspaper article. To achieve their purpose they must present what they have to say in vivid images and stir the emotions.And yet in selecting their examples and in planning the emphasis of their argument they must regulate themselves by the coldest objective standards. To interpret science to the public is in such circumstances an undertaking of the highest trust and responsibility, worthy of the attention of the finest scientific brains we have. Within this large field of making science understandable by the public is a narrower field, and the need for it to be adequately filled has been most vividly brought home to me during a now long experience of politics. The politician, and I include the statesman and all who have the direction and decision in affairs of government, is frequently faced with problems the solution to which depends upon an assessment of abstruse scientific facts or probabilities.As we know, the politician is rarely himself equipped to undertake this assessment. For example, what minister is there who from his own knowledge of atomic science or of biology can provide the current answers of science to the questions provoked by the threat of the hydrogen bomb? He must turn to some authoritative scientific source of information. It must not only be reliable, it must be shorn of the suspicion of party-political affiliation. WRere is he to find it, particularly if science has so involved itself with party politics that individual scientists have aligned themselves with political parties and their opinions have thereby become-rightly or wrongly-suspect and liable to be discounted accordingly? Just as historically the political bishop came to be treated with reserve, so, too, the political scientist handicaps himself and renders less effective his services both to politics and to science.An historic example of the force with which a completely objective case can be presented for a scientific purpose is Sir Henry Dale’s letter to The Times on August 8th, 1945, a few days after the first atom bomb had been dropped. He discusses the claims of scientific freedom as opposed to the secrecy imposed by considerations of security. “This achievement [nuclear fission],” wrote Sir Henry, “at all stages, has been the greatest of war secrets, kept with a magnificent loyalty. The scientists concerned will remain loyal to that duty, guarding closely whatever has still to be kept secret till the war with Japan Far from it.The interpretation of science to laymen is no easy task. Where is he to find i t ?282 LINSTEAD : SCIENCE AND POLITICS [Vol. 83 is finished. Then, I believe, they will wish to be done with it forever. We have tolerated much, and would tolerate anything, to ensure the victory for freedom; but when the victory is won we shall want the freedom.” Another example, on a different plane, but in its own way intensely stimulating, is the paper read by Sir Charles Goodeve before the South Wales Institute of Engineers at their Centenary Meeting on October 29th, 1967. He called it “The Development of Britain’s Physical and Geographical Advantages.” He shows how unevenly Britain has developed her advantages and how in fields where there is little or no direct competition the utilisation of our coal and water, for example, we have lagged seriously behind others.He shows a clear appreciation of how politics can bedevil the application of science to improving our affairs. “We are slow,” he says, “to apply modern knowledge because to do this means change and change means hurting a few and benefitting others, generally many others. Those who are about to be hurt scream loudly ; those who will benefit keep quiet for fear that they become a target for the screams of the first group. Change leads to opposition and as 2 consequence a large part of our scientific effort remains unused.” But this does not prevent him from advocating the remedy that, as a scientist surveying our problems objectively against the background of intense scientific development everywhere, he regards as essential-capital investment in modernising industry and its services. And he does this boldly, although recognising that “the vast majority of people will vote for subsidised housing, free medicines, old age pensions, etc., without being conscious of the consequences.This country needs investment more than anything else, but this can only be achieved at the expense of current consumption, the curbing of which is apparently politically impossible.” I am personally not prepared to believe that even this need be politically impossible if science will only tell the community persuasively and clearly what science knows, and I have put these two examples to you to emphasise the sort of r81e that science can fill and that the country badly needs science to fulfil. A most effective instrument for developing an association between politics and science on a non-party and objective basis is the Parliamentary and Scientific Committee.This consists of some two hundred members of both Houses of Parliament and of all parties, together with representatives of a large number of professional scientific bodies. It forms a bridge between science and politics, enabling members of Parliament to listen to the views of experts on scientific problems that have a bearing on the country’s development and enabling scientists to make contact through the members of Parliament with ministers and others who are responsible for the counkry’s educational, scientific and economic progress.Let me now try to sum up the argument to which you have listened so patiently. I have been urging that in politics as it is generally understood, that is the rough and tumble of the party-political arena, there is really no appropriate place for the scientist. I am urging him to be the referee, not the player. There can be no socialist physics nor conservative biology: life peerages may remove even heredity from the Upper Chamber. But in the full field of politics, embracing the whole life of the community, the scientist has a part to play of still almost unsuspected importance. He must be not only the discoverer of new things, but also the interpreter of them. He has not only the right, he has the duty to offer advice according to the highest standards of scientific objectivity.All too often the scientist writes off the politician as someone before whom scientific pearls are cast in vain because he is too concerned with what is popular to busy himself with what is right. In so far as that is true, it underlines this duty that lies on the scientist to interpret his beliefs to those who have the practical duty of applying scientific discoveries to daily affairs. And in so far as it is true that, as a condition of governing at all, the politician must carry the man in the street with him, then the second imperative duty for the scientist who would exercise authority in public affairs is the selling of his discoveries and all they mean to the public. He will have no difficulty in attracting a crowd once he sets up his stall. They are hungry to buy.His problem will arise because so often what he has to sell is so much less than they ask. Science has given to the man in the street so many miracles that he has become insatiable. And he will not believe the scientist who may modestly protest that he does not know, that only time will show or that experiments are inconclusive. Never- theless, the responsibility is squarely on the scientist’s shoulders to help out the politician by revealing to the man in the street the meaning of new discoveries, their limitations and, above all, their more uncomfortable, unpopular or even disastrous implications. And allMay, 19581 LINSTEAD SCIENCE AND POLITICS 283 that must be done in the passionate images which alone will attract and hold attention, yet must at the same time be illuminated solely by the cold, objective light of scientific truth.Much of what I have been saying is well summed up in a private note written by Lord Halsbury, which he has kindly said I may quote to you- “The responsibilities of scientists for the moral consequences of their work must be shared with the community. Any discovery can be put to good or evil use. It does not appear to me that scientists can do more as scientists than explain as clearly as possible to the rest of the community where the possibilities for evil latent in any of their discoveries really lie. The issue is, therefore, whether they do this effectively or ineffectively. I believe scientists would do this more effectively if they could speak on political issues with more authority. I believe this authority would come best from the exercise of a self-denying ordinance in political matters, namely by dissociating themselves from any political party whatever and behaving as public servants are expected to behave.” He goes on to say that this is by no means a negligible request to make of them, since many have sincere and strongly held views. But the things they lose are more than com- pensated for by the contribution that they make to the moral store of humanity. Sir Henry Dale said at the end of the letter from which I have quoted, “The true spirit of science working in freedom, seeking the truth only and fearing only falsehood and concealment, offers its lofty and austere contribution to manJs moral equipment, which the world cannot afford to lose or to diminish.” Julien Benda challenges the scientist as much as any other of the intellectuals. He reminds us that there are certain fundamental standards and truths, represented in the field with which we are more particularly concerned by the objectivity of science, which are in grave danger in this present age. He maintains that it is the duty of the intellectual to protect those standards at all costs. And he then goes further and asserts that if he is to perform that duty the intellectual must keep himself clear of the compromises and tempta- tions of the world of politics. Only so, he asserts, can the truths which so quickly become casualties in the buffetings of everyday existence be kept untarnished. Though the intel- lectual himself may be crucified, says Benda, yet his words will haunt the memory of men: that is to say, the truths will go marching on until at length they prevail.

ISSN:0003-2654    

DOI:10.1039/AN9588300275

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

May, 19581 LINSTEAD SCIENCE AND POLITICS 283 The Spectrophotometric Determination of Parathion and p-Nitrophenol BY ELSA H JELT AND ANNA-LIISA RIUKULA (Institute of Forensic Medicine, University of Helsinki, Helsinki, Finland) Equal amounts of sample are heated in aqueous alkaline and in alkaline benzene solutions. In benzene solution, no hydrolysis of parathion occurs. The products are extracted with a (1 + 4) mixture of benzene and acetone, which dissolves both parathion and p-nitrophenol. The absorption of these solutions is measured over the wavelength range of 400 to 430 mp. In this region p-nitrophenol has a well defined absorption peak and parathion shows no absorption. The absorption of the unhydrolysed solution measures the background absorption from absorbing substances other than parathion.By subtracting this background absorption from that of the hydrolysed sample, the absorption of fi-nitrophenol formed by hydrolysis of parathion is measured. The ultra-violet spectrum of the sample in 94 per cent. ethanol is also measured, and $-nitrophenol is identified before and after hydrolysis by paper-ckromatographic methods. PARATHION (diethyl P-nitrophenyl phosphorothionate) is a commonly used insecticide. It is volatile in steam, sparingly soluble in water and soluble in most organic solvents, e g . , benzenef and light petroleum.2 When parathion is heated with alkali it is hydrolysed and the products include P-nitrophenol. The analytical methods for the identification and determination of parathion include paper-chromatographic method^^,^^^; methods based on the reactions of the aromatic nitro group6~7~* y 9 ; the spectrophotometric determination of parathion5sf0,1f s12,13; and, above all, methods based on the determination of p - n i t r ~ p h e n o l .~ ~ ~ ~ , ~ ~ ~ 918,19920284 H JELT AND MUKULA: THE SPECTROPHOTOMETRIC DETERMINATION [Vol. 83 1x1 some of the methods in which the identification and determination of parathion is based on the measurement of the absorption of parathion itself and that of p-nitrophenol after hydrolysis, the results are erroneous. For example, some commercial preparations of para- thion contain impurities, such as P-nitrophenol and emulsifying agents, which cause background absorption and thus affect the accuracy of the determinati0n.l ,11 These impurities must either be removed or compensation must be made for the background absorption caused by them.We have observed that the alkali salts of p-nitrophenol can be extracted from strong alkaline solutions with a mixture of benzene and acetone, and that the presence of benzene prevents hydrolysis of parathion. These facts, as well as the characteristic absorption in the ultra-violet region exhibited by parathion in ethanolic solution, and by P-nitrophenol in alkaline benzene - acetone solution in the visible region, make possible the determination of both P-nitrophenol and parathion, and also the measurement of the amount of background absorption in the visible region. The absorption spectra of e-nitrophenol and parathion are shown in Fig. 1. Wavelength, mp Fig.1. Absorption spectra: curve A, parathion in 94 per cent. ethanol; curve B, P-nitrophenol in 94 per cent. ethanol; curve C, P-nitrophenol in alkaline benzene - acetone solution It can be seen that both p-nitrophenol and parathion have absorption peaks in the ultra- violet region. In the visible region, p-nitrophenol has a well defined peak, whereas parathion shows no absorption. Beer’s law is obeyed over the concentration range used. The wave- length ranges used were from 235 to 320 mp and from 400 to 430 mp. In 94 per cent. ethanol the absorption peak of parathion occurs at 274mp, and that of P-nitrophenol at 315 mp. The absorption peak of P-nitrophenol in alkaline benzene - acetone solution varies between 408 and 422 mp, depending on the alkalinity of the solution.The principle of our method is as follows. The sample is extracted with an organic solvent, and three aliquots of equal size are each evaporated to dryness under reduced pressure. Benzene is added to another before the hydrolysis with alkali and both the reaction products are extracted with benzene - acetone mixture (1 + 4 by volume). The third residue is dissolved in 94 per cent. ethanol. The three solutions thus obtained are designated A , B and C. The optical densities of solutions A and B are measured at 420 mp against a blank solution identical with the test solution except that the sample has been omitted. The optical density of solution C is measured at 280mp against 94 per cent. ethanol. In the calculation, the following designations are used- A = the solution obtained after hydrolysis with alkali, B = the solution obtained after treatment with benzene and hydrolysis with alkali, C = the unhydrolysed ethanolic solution, One residue is hydrolysed with alkali.= parathion,May, 19583 OF PARATHION AND P-NITROPHENOL = P-nitrophenol, = extraneous absorbing materials, E = molar extinction coefficient, and c = molar concentration. 286 It is assumed that the initial sample contains parathion, p-nitrophenol and extraneous According to Beer's law, we have the following equations-- materials that also absorb in the same regions. At wavelength 420 mp, E, = AEP + EN + AEx . . . . . . * * (1) and E, = BEP + EN + BEz. . . . . . . . . ( 2 ) .. . . * - (3) At wavelength 280 mp, E, = EP + EN + Ex. (in which AEP = the optical-density contribution of parathion in solution A ) , ..A s no hydrolysis occurs when parathion is heated with alkali in the presence of benzene, and as parathion shows no absorption-at 420 mp, then- Ep = Ep = 0. Provided that the background absorption at 420 mp caused by extraneous materials amounts to the same value in both solution A and solution B, then- AEx = BEx* Subtraction of equation (2) from equation (1) gives- As 1 mole of P-nitrophenol is formed from 1 mole of parathion, then according to E, - E B = ,E~-+No. . . . . . . - - (4) Beer's law- cp = EA - (at wavelength 420 mp). . . .. * - (5) EN From equations (l), (2) and (ti), we can obtain the amount of p-nitrophenol formed on hydrolysis. This gives the true amount of P-nitrophenol, as the interfering absorbance due to extraneous materials is eliminated.On the other hand, if p-nitrophenol is the only substance present that absorbs at 420 mp, its concentration before hydrolysis is given by the equation-- . . .. * * (6) . . . . E B CN =- EN The concentrations of both parathion and p-nitrophenol are thus found and, as the molar extinction coefficients of both substances are known, the optical-density values at 280mp can be calculated. If the sum of these calculated values is equal to the optical density of the unhydrolysed solution C, then parathion and p-nitrophenol only are present in the sample, and their identification is confirmed both qualitatively and quantitatively. Even in the presence of extraneous absorbing materials, the amount of P-nitrophenol formed on hydrolysis can be reliably ascertained. EXPERIMEKTAL APPARATUS- All spectrophotometric measurements were made with a Beckman DU spectrophotometer with use of 1-cm silica and Corex cells.Hydrolysis of the parathion was effected in a special separating funnel constructed for this purpose and shown in Fig. 2. The extraction of the sample, the subsequent evaporation of the extract to dryness under reduced pressure, the hydrolysis in a closed system and the extraction of the hydrolysed product were performed in this vessel. REAGENTS- Parathion-This was further purified by dissolution in benzene and washing the benzene solution with dilute alkali, acid and water. The residue after evaporation of the benzene was dried in a vacuum-desiccator; it had dz!",C = 1.262,6 and n : O C = 1.5369.The molar extinction coefficient of parathion in 94 per cent. ethanol measured at 280 mp is 9426, which, for a concentration of 1 pg per ml, is 0.032.286 H JELT AND MUKULA: THE SPECTROPHOTOMETRIC DETERMINATION [Vol. 8 After recrystdlisation , the melting-poin was 112" C. The molar extinction coefficient in 94 per cent. ethanol measured at 280 m, is 4210, which, for a concentration of 1 ,ug per ml, is 0.030. p-Nitrophenol--The Merck product was used. Fig. 2. Reaction vessel for the hydrolysis All other reagents used were of recognised analytical grade. Pure parathion was kindly supplied by the Institut fur Gerichtliche Medizin an de of parathion Medizienischen Akademie Dusseldorf. PRELIMINARY EXPERIMENTS- Preliminary experiments for the spectrophotometric determination of p-nitrophenol i i alkaline benzene - acetone solution were performed, and the hydrolysis of parathion in alkalin solution was investigated both in the pres'ence and absence of benzene.The spectrophotometric detemination of p-nitrophenol in alkaline benzene - acetone solutio:, (1 + 4 by voZztwze)-To study the extraction of p-nitrophenol from a quantitative standpoint the following experiments were performed-- (i) $-Nitrophenol was dissolved in 5 or 10 rnl of alkaline benzene - acetone solution This was prepared by saturating the (1 + 4) mixture of benzene and acetone wit1 3.5 N potassium hydroxide. (ii) p-Nitrophenol was dissolved in 2ml of 3.5N potassium hydroxide and extractec from this solution with 10, 20 or three 10-ml portions of benzene - acetone mixture The solutions were diluted with alkaline benzene - acetone solution to a suitable volume clarified with acetone in the volumetric ratio 4 to 1, and the optical densities were measure( at 420mp.The results are shown in Table I. TABLE I EXTRACTION OF p-NITROPHENOL FROM POTASSIUM HYDROXIDE SOLUTION WITH BENZENE - ACETONE SOLUTION (1 + 4) Weight of p-nitrophenol in 3.6 N potassium hydroxide solution, pg 8 20 20 80 80 80 100 200 400 400 400 Concentration of p-nitro- phenol in final solution, Pg Per 0.64 1-60 3.20 6-40 3.20 1.28 8-00 6.40 6.40 6.40 6-40 Optical density a t 420 mp s&zz-= (4 (ii) - 0.106 0.265 - 0.536 - - 1.057 - 0-530 - 0.212 - 1.340 - 1.053" - 1*040* - 1.064 I 1.066 * The alkali lilyer w2s yellowish. Volume of benzene - acetone (1 + 4) used for extraction in experiment (ii), ml 10 - - 10 20 3 x 10 10 10 10 20 3 x 10 Extinction coefficient for 1 pg of p-nitrophenol per ml 0-166 0.166 0.168 0.165 0.166 0.166 0.168 0.165 0.163 0.166 0.167May, 19581 OF PARATHION AND P-NITROPHENOL 287 The results in Table I show that 100 pg of p-nitrophenol in 2 ml of 3.5 N potassium hydroxide are extracted quantitatively with 10 ml of benzene - acetone solution and amounts as high as 400 pg can be extracted quantitatively with 20 ml of benzene - acetone. Further, it can be seen that the absorption of P-nitrophenol in alkaline benzene - acetone solution obeys Beer's law over the concentration range of 0.64 to 8.0 pg per ml at 420 mp.Hydrolysis of ~a~athion-Ketelaar~~ states that the hydrolysis of parathion with alkali is a bimolecular reaction; the half-time at 15" C with N alkali is 32 minutes.Big$ reports that, when parathion is heated with ethanolic potassium hydroxide for 3 hours in sealed ampoules, the yield of p-nitrophenol is 87 per cent. In our work the hydrolysis was carried out by heating parathion with 3.5 N potassium hydroxide at 100" C in the reaction vessel shown in Fig. 2. To determine the percentage hydrolysis, different amounts of parathion were hydrolysed and the p-nitrophenol formed was determined as described previously. The results are given in Table 11. TABLE I1 HYDROLYSIS OF PARATHION IN 3.5 N POTASSIUM HYDROXIDE AT 100°C FOR 2 HOURS Amount of parathion present, tLg 40 41 60 80 82 82 120 123 160 Weight of p-nitrophenol found, CLg 18.2 18.0 27.4 35-2 36.3 37.5 52.8 55-2 71.4 Calculated amount of parathion, tLg 38.1 37.8 57.4 73.7 76.0 78.5 110.6 115.6 149.5 Hydrolysis, 95.3 94.9 95.6 92.1 92.7 95.7 92.2 94.0 93.4 % It can be seen that the hydrolysis varied between 92.1 and 95.7 per cent.The mean value, 93.7 per cent., is the same as that reported by Ketelaar. Hydrolysis of payathion in the presence of benxene-It was observed that benzene prevents the hydrolysis of parathion by alkali. Experiments were therefore made in which parathion was allowed to stand in benzene and was then boiled with strong alkali. In other experiments, parathion was allowed to stand in alkaline acetone solution both with and without the addition of benzene. Some of these benzene solutions were shaken with 2 ml of 3-5 N potassium hydroxide and the mixtures were kept at room temperature for 24 hours, with intermittent shaking.The other solutions were boiled under reflux with 2 ml of 3.5 N potassium hydroxide for 2 hours. The phases were separated and the benzene layer was washed with dilute acid and with water. One millilitre of the washed benzene solution was removed by pipette and evaporated to dryness under reduced pressure at 50" C. The residue after evaporation was dissolved in 94 per cent. ethanol and the optical density of the solution was measured at 280 mp. The results Different amounts of parathion in 2 ml of benzene were treated with alkali. are shown in Table 111.- TABLE I11 HYDROLYSIS OF PARATHION IN BENZENE WITH Amount recovered after 24 hours a t room of parathion, temperature, p g per 2 ml Initial concentration pg per 2 ml 80 79.1 120 118.6 160 159.7 2000 - 3.5 N POTASSIUM HYDROXIDE Amount recovered after 2 hours a t 100" C, pg per 2 ml 78.4 119-3 160.3 2001.1 From Table I11 it can be seen that no hydrolysis occurs when benzene is used as the In benzene, parathion can be heated with strong alkali, treated with dilute acid solvent.and with water, and freed from the organic solvent without any loss.288 H JELT AND MUKULA: THE SPECTROPHOTOMETRIC DETERMINATION [VOl. 83 In other experiments, different amounts of parathion were dissolved in 8 ml of acetone, and in 10 ml of the (1 + 4) benzene - acetone mixture. The solutions were shaken with 2ml of 3 6 N potassium hydroxide for 1 minute and set aside at room temperature for different lengths of time.The reaction times were 1, 3 and 24 hours. Two millilitres of benzene were then added to the solutions containing acetone as the solvent, and the solutions were shaken again. After separation of the phases, the benzene - acetone layer was prepared for spectrophotometric measurement as described under “Procedure.” The results are shown in Table IV. TABLE 1v HYDROLYSIS OF PARATHION IN ALKALINE SOLUTIONS OF ACETONE AND BENZENE: - ACETONE (1 + 4) Concentration Reaction of parathion, time, iug Per ml hours 1 40 1 4 1 80 With acetone as solvent- -- amount of Iptical density p-nitrophenol a t 420 mp formed, pg 0.006 0.0 0.022 1.7 0.117 8.8 0-016 0.0 0.047 3.5 0.22 1 16.7 With benzene - acetone solution (1 + 4) as solvent- amount of optical density fi-nitrophenol a t 420 mp formed, pg 0.002 0.0 0.007 0.0 0.051 3-63 0-004 0.0 0.007 0.0 0.109 8.2 A f \ The results in Table IV show that, in alkaline acetone solution, parathion is appreciably hydrolysed during the first 3 hours, and mobe than 40 per cent.is hydrolysed in 24 hours. In the presence of benzene, however, hydrolysis is retarded. No absorption due to p-nitrophenol can be detected after 3 hours and only about 20 per cent. of parathion is hydrolysed in 24 hours. The optical density of parathion together with the optical density due to extraneous materials can therefore be measured with0u.t interference from the hydrolysis, provided that the reaction time does not exceed 3 hours. METHOD PROCEDURE- Hydrolysis of pavathion-Parathion is dissolved in an organic solvent and an aliquot containing from 20 to 200 pg is transferred by pipette to the reaction vessel.The solution is evaporated to dryness under reduced pressure at 50” C. Two millilitres of 3.5 N potas- sium hydroxide are added to the residue, the stopper is fastened with a rubber band and the vessel is placed in a boiling-water bath. After 30 seconds, the stopcock is closed and heating is continued for 2 hours. After cooling, 5 to 20 ml (V,) of benzene - acetone solution (1 + 4) are added, the mixture is shaken for 1 minute and then set aside for 10 minutes, after which the alkali layer is removed, Four millilitres of the benzene - acetone layer are removed by pipette and mixed with 1 ml of pure acetone. This solution is used for the spectro- photometric determination.The optical density of this solution, which is designated solution A , remains unchanged for at least 24 hours. Determination of p-nitrophenol and the background absorption-An aliquot of equal size to that used for the hydrolysis is placed bsy pipette in the reaction vessel and evaporated to dryness. From 1 to 4 ml of benzene are added to the residue, and then 2 ml of 3.5 N potassium hydroxide, A reflux condenser is attached to the vessel and the solution is heated under reflux in a water bath for 2 hours. After it has cooled, the solution is shaken with 4 to 16ml of acetone, and the layers are separated. Four millilitres of the benzene- acetone layer are removed by pipette and. diluted with 1 ml of acetone.This solution is used for the spectrophotometric determination. The optical density of this solution, which is designated solution B, remains unchanged for 3 hours. PreParation of the blank solution-Ten millilitres of benzene - acetone solution (1 + 4) are shaken with 2 ml of 3.5 N potassium hydroxide. The layers are separated and 4 ml of the benzene - acetone layer are removed by pipette and diluted with 1 ml of acetone. This is the blank solution. Its optical density remains unchanged for at least 24 hours.May, 1958] OF PARATHION AND p-NITROPHENOL 289 Preparation of the control solution-An aliquot of equal size to that used for the hydrolysis is evaporated to dryness. The residue is dissolved in 5 to 20 ml (V,) of 94 per cent. ethanol. This is solution C.Measurement of optical density-The optical densities of solutions A and B are measured against the blank solution at 420 mp. This gives the values of E, and E, in equations (1) and (a), p. 285. The optical density of solution C is measured at 280 mp against 94 per cent. ethanol. This gives the value for E, in equation (3). Pa9er-chromatographic detection of p-nitrophenol-The hydrolysed and unhydrolysed solutions are chromatographed. By using the ascending-solvent technique with a (1 + 1) mixture of isobutyl and isoamyl alcohols saturated with ammonia as solvent; the RF value for p-nitrophenol is 0.48. The chromatograms are allowed to develop at 23" C for 18 hours. The spots are detected by spraying with ammonia or alkali. CALCULATIONS- To calculate the results, the constants for a concentration of 1 pg per ml are as follows- For P-nitrophenol in solutions A and B at 420 mp, eN = 0.166.For p-nitrophenol in ethanol at 280mp, E~ = 0.0303. For parathion in ethanol at 280 mp, ep = 0.0324. The percentage hydrolysis is 93.7, and the molecular weights of parathion and +nitro- Hence the concentration of parathion is given by- If V , is the volume of benzene - acetone solution, and V , the volume of ethanol used, phenol are 291.3 and 139.1, respectively. cp = 2-23 x concentration of p-nitrophenol in solution A . then, by applying equation (5), the amount of parathion per aliquot is given by- The corresponding optical density measured at 280 mp is- 16.8 x V l x ( E A - EB) pg. V Ep = 0.545 x -2 x (EA - E,). v2 From equation (6)- Weight of P-nitrophenol per aliquot = 7.54 x V , x E, pg.The corresponding optical density measured at 280 mp is given by- V If the sum of the calculated values for EP and E N is equal to Ec (all measured at 280 mp), If this sum is smaller E N = 0.227 x 2 x E,. v 2 the amounts of both parathion and p-nitrophenol are confirmed. than E,, the amount of P-nitrophenol formed on hydrolysis can be determined. RESULTS Prepared mixtures of parathion and fi-nitrophenol and some commercial preparations were analysed. The results of four such analyses calculated in micrograms per millilitre are given below. (i) A solution containing 80 pg of parathion and 21-9 pg of p-nitrophenol in 1 ml of benzene was prepared. The presence of fi-nitrophenol was detected, both before and after hydrolysis , by paper-chromatographic techniques.EA was 0-768 and EB was 0-286, therefore EA - E, was 0.482. The amount of +-nitro- phenol found was 21.6 pg, for which, at 280 mp, E N = 0.065. The amount of parathion found was 80.9 pg, for which, at 280 mp, EP = 0.263. It was found that, at 280 mp, Ec = 0-336. From these results it can be concluded that the sample contains 80.9pg of parathion and 21-6 pg of p-nitrophenol. (ii) A commercial powder contains about 20 per cent. of parathion, according to specification. An extract containing 200 pg of the sample in 1 ml of benzene was prepared. The paper-chromatographic study showed that, before hydrolysis, no fi-nitrophenol was present, but after hydrolysis a positive result was obtained. In each analysis both V , and V , were 10ml. Ep + E N z= 0.328.290 HJELT AND MUKULA [Vol.83 EA was 0.284 and E, was 0.001, therefore EA - E, was 0.283. No p-nitrophenol was found, and the amount of parathion found was 47.5 pg, for which, at 280 mp, EP = 0.154. It was found that, at 280 mp, E, = 0.15'7. From these results it can be concluded that the sample contains about 23.7 per cent. of parathion. (iii) A commercial fluid contains about 35 per cent. of parathion, according to speci- fication. An extract containing 133.9 pg of the sample in 1 ml of benzene was prepared. The paper-chromatographic study showed the presence of (P-nitrophenol both before and after hydrolysis. EA was 0.263 and E, was 0.036, therefore EA - EB was 0.227. The amount of p-nitro- phenol found was 2-7 pg, for which, at 280 mp, EN = 0.008, and the amount of parathion found was 38.2 pg, for which E, = 0.124. It was found that Ec = 0.161.From these results it can be concluded that the sample contains about 28.5 per cent. of parathion, not more than 2.0 per cent. of P-nitrophenol and extraneous absorbing materials. (iv) A commercial fluid contains 33.5 per cent. of parathion, according to specification. An extract containing 126-9 pg of the sample in 1 ml of benzene was prepared. The paper- chromatographic study showed the presence of P-nitrophenol both before and after hydrolysis. E, was 0.346 and E, was 0.092, therefore E, - EB was 0.254. The amount of $-nitro- phenol found was 6.9 pg, for which, at 280 mp, EN = 0.021. The amount of parathion found was 42-7 pg, for which E, = 0.138.It was found that Ec = 0.235. From these results it can be concluded that the sample contains about 33.6 per cent. of parathion, not more than 5.4 per cent. of (P-nitrophenol and extraneous absorbing materials. Ep + E N = 0.154 + 0 = 0.154. Ep + EN = 0.132. Ep + EN = 0.159. CONCLUSIONS By using the proposed method the p-nitrophenol formed on hydrolysis of parathion can be determined. The background absorption does not interfere with the determination, as it can be measured separately. The method is applicable to the determination of parathion in commercial preparations. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. REFERENCES Biggs, A. I., Analyst, 1965, 80, 279. Edwards, F. I., jun., and Hall, S. A., U.S. Patent 2,606,279 (July 29th, 1952); Chem. Abstr., Metcalf, R. L., and March, R. B., Science, 1953, 117, 527. Cook, J. W., J . Ass. 08. Agric. Chem., 1954, 37, 987. Fiori, A., Nature, 1956, 178, 423 Averell, P. R., and Norris, M. V., Anal. Chem., 1948, 20, 753. O'Keeffe, K., and Averell, P. R., Ibid., 1951, 23, 1167. Yamamura, J., and Niwase, T., Kagaku to, Sbsa [Science and Crime Detection], 1954, 7, 195; Chem. Paulus, W., Mallach, H. J., and Janitzki, U., Arzneimittel-Forsch., 1955, 5, 241. Sokol, F., Chem. Zvesti, 1953, 7 , 429. Derkosch, J., Jansch, H., Leutner, R., arid Mayer, F. X., Monatsh. Chem., 1954, 85, 684. Kotakemori, M., Ann. Re$. Takamine Lab., 1954, 6, 146; Chem. Abstr., 1955, 49, 16307~. Schmidt, G., Arch. ToxicoE., 1955, 15, 361. Eicken, S. V., Angew. Chem., 1954, 66, 551. Pfeil, E., and Goldbach, H. J., Klin. Woclzschr., 1953, 31, 1011. Jachimovicz, T., &err. Chem.-Ztg, 1954, 55, 190. Briegleb, G., and Angerer, G., Angew. Chem., 1952, 64, 685. Schroeder, W. A., Wilcox, P. E., Trueblood, K. N., and Dekker, A. 0.' Anal. Chem., 1951, 23, Ketelaar, J. A. A., Rec. Trav. Chim. PaysBas, 1950, 69, 649. Buckley, R., and Colthurst, J. P., Analyst, 1954, 79, 285. 1952,46, 10525~. Abstr., 1955, 49, 76301. 1746. Received May 31st, 1967

ISSN:0003-2654    

DOI:10.1039/AN9588300283

出版商:RSC    

年代:1958

数据来源: RSC

摘要:

May, 19581 WAGER 29 1 The Determination of Ethanol and Acetaldehyde in Plant Tissue by Low-temperature Diffusion BY HAROLD G. WAGER (Low Temperature Station for Research in Biochemistry and Biophysics, University of Cambridge and Department of Scientific and Industria2 Research, Downing Street, Cambridge) A method for the determination of ethanol and acetaldehyde is proposed, based on the transfer of volatile substances from frozen tissue to aqueous sulphuric acid by evaporation and diffusion. The determination is easy to carry out, but the diffusion requires a long time. The material is maintained at a low temperature and the method, therefore, is theoretically preferable to a distillation method. The amount of acetaldehyde volatilised from peas is shown to be much greater when it is distilled in steam than when it is volatilised at a low temperature. ETHANOL and acetaldehyde have been separated from plant tissue by steam-distillation.1 When the total amount of acetaldehyde and ethanol is small, either by reason of a very low concentration or because of the small size of sample available, the loss during normal steam-distillation is serious, with the result that a procedure has to be adopted in which any uncondensed vapour of ethanol or acetaldehyde is trapped.Besides this practical difficulty, all distillation methods have the disadvantage that the tissue is heated for relatively long periods, during which volatile interfering compounds may be produced (perhaps even ethanol or acetaldehyde). It was found, for instance, that repeated distillations of the same sample of peas in water gave a slow but continuing production of volatile substances, see Table IV, p.295, and an extract of potatoes under acid conditions gave rise to large amounts of volatile material.2 Separation of ethanol from blood or urine by volatilisation at about room temperature has been proposed by Widmark,3 Winnick4 and CavettJ5 but, if applied to plant material, it is likely to be open to the same objections as the distillation method and the preparation of sub-samples of vegetable tissue, suitable for the method, presents great difficulty. In view of these difficulties, the theoretically much sounder alternative of volatilising the ethanol from the material in the frozen state was considered. In practice, frozen peas were held over sulphuric acid in a sealed container at a low temperature.Water and other volatile substances evaporated from the frozen tissue and diffused to the sulphuric acid with about the same time of half-transfer. At a low temperature, i.e., -20" C, there should be little risk of production or destruction in the material of either ethanol or acetaldehyde and both should be stable in the sulphuric acid. Unfortunately, at -20" C the time required for transfer of ethanol to the sulphuric acid was unreasonably long and a temperature of -12" C was used instead. Even at this temperature 70 to 100 days were required for complete transfer of the ethanol from 20 to 40g of whole peas. Movement of volatile substances from the peas was relatively rapid at first, but, as the outer layers dried, an additional resistance to diffusion arose and the rate slowed down progressively.The water content of much of the pea was low for most of this 100-day period, so that side reactions were presumably considerably reduced compared with frozen wet material stored at -12" C. EXPERIMENTAL DETERMINATION OF ETHANOL AND ACETALDEHYDE- The reducing value of the absorbed volatile substances was determined iodimetrically by the amount of chromic acid required to oxidise them in aqueous 50 per cent. sulphuric acid at 100" C, as described by Kozelka and Hine.'j The reducing value equivalent to the acetaldehyde is subtracted and the residual reducing value has been treated as ethanol. Acetaldehyde was determined by a modification of the colorimetric method proposed by Barker and Sumrner~on,~ in which acetaldehyde in diluted sulphuric acid (6 + 1 v/v) is treated with $-hydroxydiphenyl.The changes introduced are (a) the mixture of acetalde- hyde and copper sulphate with diluted sulphuric acid (6 + 1 v/v) is cooled in iced water, (b) double the amount of P-hydroxydiphenyl reagent is used, and (c) the reaction is allowed292 WAGER THE DETERMINATION OF ETHANOL AND ACETALDEHYDE [VOl. 83 to proceed at 20" C for 30 minutes. Batches of sulphuric acid tested were found to be liable to have a low and variable negative blank value for acetaldehyde and, to overcome this, acetaldehyde was added to all the acid used until a small positive blank value was obtained. SEPARATION OF VOLATILE SUBSTANCES BY DISTILLATION- A distillation method was designed, in.which peas in water, Le., at their natural pH of about 6.5, were distilled at 100" C for 30 minutes. Loss of acetaldehyde and of ethanol from the collecting end was prevented by the use of a scrubber of aqueous 50 per cent. sulphuric acid followed by one of diluted sulphuric acid (6 + 1 v/v). Distillation of 40 mg of ethanol from pure solutions gave a mean recovery of 99.6 per cent. (range of 7 tests, 99.2 to 100.0 per cent.) and of 200 pg of acetaldehyde gave a mean recovery of 98.6 per cent. (range of 8 tests, 97.7 to 102-6 per cent.). Replicate samples of pea powder also gave good agreement. SEPARATION OF VOLATILE SUBSTANCES BY DIFFUSION- The chemical methods used in this work require the ethanol to be dissolved in aqueous 50 per cent.sulphuric acid and the acetaldehyde in sulphuric acid diluted exactly (6 + 1 v/v). To obtain the maximum concentration of the ethanol for subsequent determination, it should be volatilised into the least volume of sulphuric acid that will give a concentration of just above 50 per cent. at the end of the diffusion. Ethanol is quantitatively absorbed by acid of this or higher concentration. First, during the transfer of acetaldehyde to sulphuric <acid of high concentration there is always some destruction of the acetaldehyde, and there is a further continuing slow loss on standing. This loss was greatest in pure sulphuric acid and less when the acid was diluted with water; with aqueous 70 per cent. sulphuric acid it was small and with 50 per cent.could not be detected. Secondly, there is a significant concentration of free acetaldehyde in 50 per cent. sulphuric acid, which decreases as the concentration of acid is raised and in 85 per cent. sul- phuric acid is insignificant. This free acetaldehyde sets up a vapour pressure in the gas phase and, in consequence, absorption by 50 per cent. sulphuric acid is incomplete. As a compromise between these opposing requirements, the highest concentration of sulphuric acid used was 66 per cent. and this fell to about 50 per cent. by uptake of water during the diffusion. In this way destruction of acetaldehyde was avoided, but absorption was incom- plete. These concentrations resulted in the use of a large volume of sulphuric acid with consequent dilution of the ethanol.If ethanol alone is being determined, it is best to use sufficient pure sulphuric acid to end the diffusion with a concentration of 50 per cent. Determinations are carried out in a crystallising dish that has a rim ground to make a good fit with a thick glass plate that serves as a lid. There is a small hole in the lid that is sealed with a glass slide. A sealing compound, such as Vaseline, that hardens at -12" C is put round the rim of the dish and the calculated amount of 66 per cent. v/v sulphuric acid is added by weighing. A small glass tripod supporting a wire tray to contain the peas is next put in and the whole is cooled to --12" C. Then, as rapidly as possible, the dish is brought out of the cold chamber, the peas, at -20" C, are transferred to the tray, the lid, still at room temperature (to soften the sealing compound), is put on and weighted down and the whole is returned to -12" C.The hard sealing compound and the weight are to prevent leaks arising from changes in barometric pressure during the diffusion. For peas, the transfer of acetaldehyde and ethanol is sensibly complete within 70 to 100 days, but other material might require a shorter time. At the end of this period the dish is warmed to room tem- perature, the peas and tripod are rapidly removed, the lid is replaced and the acid is made to exactly 50 per cent. v/v by the addition of water through the hole in the lid until the correct weight is attained. After mixing, an aliquot of the acid is withdrawn through the hole in the lid and added to sufficient pure sulphuric acid to make the concentration exactly (6 + 1).Acetaldehyde is determined on this solution and ethanol on a sub-sample of the main bulk of the sulphuric acid. Loss of acetaldehyde from the diffusion chamber, which is relatively rapid, must be guarded against during these manipulations As a check on the completeness of transfer, the peas may be replaced at -12" C over fresh acid. This is best done in a smaller dish, as only a small volume of 50 per cent. sulphuric acid is required since the peas are dry. The quantitative absorption of acetaldehyde is difficult for two reasons.May, 19581 I X PLANT TISSUE BY LOW-TEMPERATURE DIFFUSION 293 Results of two experiments in which dilute aqueous solutions of acetaldehyde and of ethanol were determined after transfer to sulphuric acid either by direct dilution (controls) or by diffusion are given in Table I.The accuracy of the determination of ethanol by diffusion is clearly high and similar to that with the distillation apparatus. A comparison of the two methods was made on 5-g portions of a bulk sample of ground frozen peas. The results of replicate determinations by steam-distillation for 30 minutes were 8.9, 8.9, 9.2 and 9.4mg and by diffusion at -12" C for 30 days were 8.6, 8.6, 9.15 and 9.4 mg, which shows that both methods gave similar values for the ethanol content of peas. RESULTS AND DISCUSSION TABLE I RECOVERY OF PURE ETHANOL AND ACETALDEHYDE BY DIFFUSION Diffusion was carried out for 5 days at 20" C Ethanol found in controls by direct dilution, Mean, mg mg 39.3 39.4 39.3 } 39.33 Ace talde - hyde found Ethanol in controls found by Re- by direct diffusion,* Mean, covery, dilution, Mean, mg mg % CLg Pg Ei } 216 39.4 ) 39.4 100.2 39.4 39.4 215 Acetalde- hyde found by Re- diffusion, t Mean, covery, Clg CLg % % } 204 94.9 208 * Determined by volatilising 5 ml of water containing 40 mg of ethanol into 15 ml of 66 per cent.t Determined by volatilising 5 ml of water containing about 200 pg of acetaldehyde into 95 ml of Each value is the mean of two determinations. sulphuric acid. 52.6 per cent. sulphuric acid. Each value is the mean of three determinations. The recovery of acetaldehyde from pure solutions, about 95 per cent. (see Table I), is not as good as with the distillation apparatus because of the incomplete absorption of acetalde- hyde by 50 per cent.sulphuric acid. At 20" C there is in the gas phase a concentration of about 0.5 per cent. of that in the sulphuric acid, and, since the gas volume is large compared with that of the acid, the loss due to this cause is appreciable. The diffusion vessel has first to be opened to remove the material, and then allowed to re-equilibrate, with a double loss of acetaldehyde (about 3 to 4 per cent. each time when the ratio of volume of acid to gas phase is about 1 to 7). The recovery by this method, therefore, is not complete, but the loss results from a known physical cause and its size can be reasonably accurately assessed, whereas in other methods unknown chemical factors may result in large apparent errors (see below).TABLE I1 TRANSFER OF ETHANOL AND ACETALDEHYDE 'FROM ABOUT 30 TO 40g OF FROZEN WHOLE PEAS INTO ABOUT 100 ml OF 66 PER CENT. SWLPHURIC ACID AT -12" C Ethanol found Ethanol found Acetaldehyde found Acetaldehyde found in experiment 1, in experiment 2, in experiment 1, in experiment 2, Period, mg per 100 g mg per 100 g Pg Per 100 g Pg Per 100 g days fresh weight fresh weight fresh weight fresh weight 9.7.52 0 to 30 30 to 50 50 to 70 70 to 97 22.7.53 0 to 52 52 to 85 85 to 105 105 to 135 21.7.52 0 to 50 50 to 73 42.9 9.2 3.1 1.2 138 15.7 1.5 1.3 166 0.5 251 23.2 2.1 1.6 217 16.3 2.3 1.1 211 0-2 1390 510 330 30 2560 780 270 10 1470 20 2240 590 60 10 1990 680 360 50 4020 30 The amounts of ethanol and acetaldehyde transferred in successive periods at -12" C are shown for several experiments in Table 11.No reason is known for the variation in rate of transfer of ethanol in different experiments-it might have been an expression of the294 WAGER : THE DETERMINATION OF ETHANOL AND ACETALDEHYDE [Vol. 83 permeability of the testa of the peas or of the form of the ice crystals in the frozen pea, which would affect the porosity of the dry tissue. There was clearly only a very small continuing production of either volatile substance, but this, unfortunately, cannot be used as proof that there was no production in the earlier stages, since the material is wet in one case and dry in the other. In many of the experiments, as in the first two quoted, the pro- portion of the total acetaldehyde volatilisecl in the second period (sometimes in the third also) was higher than the corresponding proportion of ethanol, which suggests that there was some degree of binding of acetaldehyde t o a non-volatile component of the system.How- ever, it was always possible to continue diffusion until the transfer of acetaldehyde became negligibly small. The rate of migration of volatile substances is obviously much influenced by the length of the diffusion path and therefore the distance from the peas to the acid surface should be as short as possible. The volume of acid required depends only on the volume of water to be transferred; therefore the size of the sample, and with it the crystallising dish and volume of acid, can be altered over a very wide range with no change in over-all accuracy. There seems to be no reason why it should not be done on a micro scale if required-the difficulty would be to get the sample of frozen material into the apparatus without loss of volatile substances, which, when the tissue is at -20" C, may be present in relatively high concentration in the unfrozen phase of the tissue.The acetaldehyde content found in similar samples of peas when determined by the distillation method in 1951 and 1955 was markedly higher than that found from 1952 to 1954 by the diffusion method (see Table 111). The size of this difference between the two methods clearly depends on the condition of the pea, being least in mature and most in wilted old peas. Changes in acetaldehyde content, induced by experimental conditions, were similar in magni- tude when determined by either method, which suggests that an excess production of acetaldehyde occurs during the distillation procedure that is dependent on the condition of the peas.Evidence of such production was sought by repeatedly distilling the same sample of peas (see Table IV). TABLE I11 ACETALDEHYDE CONTENT OF COMPARABLE RANGES OF SAMPLES OF PEAS IN Steam-distillation was carried out for 30 minutes and diffusion was carried out at -12" C for periods of between 50 and 106 days Acetaldehyde Acetaldehyde DIFFERENT SEASONS found by steam-distillation in- found by diffusion in- I A \ 7 7 A wilted wilted wilted wilted mature mature old mature mature old peas, old peas, peas, peas, peas, old peas, peas, peas, l e p e r %Per %Per /%Pel- KPe' !%Per MPer CLbOper Season weight weight weight weight Season weight weight weight weight 100 g fresh 100 g fresh 200 g fresh 100 g fresh 100 g fresh 100 g fresh 100 g fresh 100 g fresh - 1951 630 410 1772 2400 2952 400 20 700 520 550 1762 1450 410 60 660 850 420 - - 460 I 400 520 _ _ - - - - - 480 480 - - - - - - - - _- 1955 2180 330 ___ - 1953 - 100 460 90 - - - 430 80 - 160 - - - - 380 110 - 520 - - 230 I - 1954 420 -- 390 110 Mean 740 370 1770 1900 Mean 440 60 490 100 In the sample of peas with a high content of ethanol (sample B) all but 3 per cent.of the ethanol was distilled over in the first 30 minutes, and a greater proportion of acetaldehyde, being more volatile, should have been removed by a similar period of distillation. In fact, successive distillations liberated large amounts of acetaldehyde, which must have been produced during the distillation.In the first distillate there should be all the free acetaldehyde together with some from the same source a!; that liberated in subsequent distillations. The amount of this "non-free" acetaldehyde is difficult to assess, but the results in Table IV suggest that it was probably not less than 200 pg in the mature peas tested and 150 pg inMay, 19581 I N PLANT TISSUE BY LOW-TEMPERATURE DIFFUSION 295 the old peas. Such an excess of “non-free” acetaldehyde is, for mature peas, comparable with the mean difference between the results by diffusion and distillation (see Table 111), but for old peas it is lower (this may be because the old peas used were very low in acetalde- hyde). It is clear that the values for the acetaldehyde content of peas obtained by the distillation method have a large and variable error and therefore the lower values obtained by diffusion become more probable.TABLE IV ETHANOL AND ACETALDEHYDE GIVEN OFF DURING SUCCESSIVE STEAM-DISTILLATIONS FOR 30 MINUTES OF THE SAME SAMPLE OF PEAS Distillation No. 1 2 3 4 5 6* Acetaldehyde driven off from mature peas, fresh weight 1180 145 106 76 66 246 tG Per 100 g Acetaldehyde driven off from old peas, fresh weight 229 98 61 47 54 261 Pg Per 100 g Ethanol driven off from sample A (aerobic), Distillation mg per 100 g No. fresh weight 1 37.2 2 13.9 3 8-1 4 - Ethanol driven off from sample B (anaerobic), mg per 100 g fresh weight 17.2 6.9 3.4 553 * Sample heated under reflux a t 100” C for 2 hours and then steam-distilled for 30 minutes.The compound broken down during the distillation is not likely to have been a normal acetaldehyde addition compound, as such a compound would probably have a higher vapour pressure of acetaldehyde than occurred in tests in the diffusion apparatus-by the final period of diffusion there was less than 1 to 2 pg of free acetaldehyde in the whole system with a volume of 1100 ml of air and 100 ml of sulphuric acid. The two methods gave values for the ethanol content of peas that agreed when portions of a bulk sample were compared or when similar samples were tested by a different method in successive seasons. Repeated distillation of the same sample of peas showed that there was a small and decreasing production of volatile reducing material, which seems to be independent of the total ethanol content of the peas, and as such is only serious at low ethanol concentrations, In complex systems, such as living tissue, it is seldom possible to determine the content of reactants in the living state.Results are nearly always based on the content found in dead material and this may differ from that in the living material, depending both on the method of killing and the method of extraction, since even after death some of the wide range of compounds present may interact, especially if heated. Differences between tissue killed at a high and a low temperature, for instance, have been shown to exist by Isherwood and Niavis8 in the determination of keto acids in plant material. In the work described in this paper, the excess of acetaldehyde appears to arise as a result of heat treatment subsequent to the death of the tissue, i.e., it is probably non-enzymic in origin. On general grounds, a method of killing and extraction carried out at a low temperature, when reaction rates are slow, is to be preferred to one that involves heating, and such a method has a greater intrinsic probability of giving an estimate of the compounds present during life. The work described in this paper was carried out as part of the programme of the Food Investigation Organisation of the Department of Scientific and Industrial Research. The experimental part of the investigation was carried out by Mr. J. R. Howe. 1. 2. 3. 4. 5. 6. 7. 8. REFERENCES Fidler, J. C., Biochem. J., 1934, 28, 1107. Barker, J., J . Exp. Bot., 1951, 2, 238. Widmark, E. M. P., Biochem. Z., 1922, 131, 473. Winnick, T., Ind. Eng. Cham., Anal. E d . , 1942, 14, 523. Cavett, J. W., J . Lab. Clin. Med., 1938, 23, 543. Kozelka, F. L., and Hine, C. H., I n d . Eng. Chem., Anal. Ed., 1941, 13, 905. Barker, S. B., and Summerson, W. H., J . Biol. Chew., 1941, 138, 534. Tsherwood, F. A., and Niavis, C. A., Biochem. J., 1956, 64, 549. First received October 25th, 1956 Amended, Januavy 27th’ 1958

ISSN:0003-2654    

DOI:10.1039/AN9588300291

出版商:RSC    

年代:1958

数据来源: RSC