November, 1979 THE ANALYST ixindustrial svstem - m - ~- - ~- ~For 14 years DlGlCO has installed advanced scientific and industrial computers across allfive continents - yes even in the U.S.A.! Installations vary from 'micros' to large'megaminis' all absolutely program and data compatible with a full range of peripheralsand instrument interfaces.Single and multi terminal systemsProcess control 0 Networking0 Medical instrumentationData loggingMathematical simulationGeophysics instrumentationFront end processing0 Multi terminal Basic systems0 Remote terminal emulationIntelligent terminals0 Teaching systemsHigh level or low level languages, interpreters or compilers, fully commissioned ornqked' systems, number crunchers, data loggers, factory controllers or just dataprocessors - test our products against any competition and measure the result forourself.Furthermore they are designed and manufactured right here in Britain - so that you cantalk to the people who actually make the hardware and solve the problems face to face.start small Tick an of the above applications,forwardlit to us and we'll send you an indepth installation dossier free of charge.Digico LimitedWedgwood Way, Stevenage, Herts , England SG1 4PYTelephone Stevenage (0438) 4381 Telex 825508Northern Area OfficeNorth Eastern Chambers, Station Parade, HarrogateTelephone (0423) 501447 Telex 57648 X SUMMARIES OF PAPERS I N THIS ISSUEDetermination of Mercaptoacetic Acid in Hair Waving andDepilatory ProductsNovember, 1979Identification of mercaptoacetic acid in hair waving and depilatory productscontaining other mercapto acids is possible by using thin-layer chromato-However, gas-chromatographic methods are to be preferred for accurate,quantitative determination.Four gas-chromatographic methods are pro-posed ; the first and the second involve derivatisation of the mercaptoaceticacid with diazomethane to the methyl ester, methyl thioether derivative.In the third method, the mercaptoacetic acid is converted into its methyl estergraphy.by use of fi-toluenesulphonic-acid.chromatography of underivatised mercaptoacetic acid.The last method involves the- directKeywords : Mercaptoacetic acid ; hai;v waving products ; depilatory products ;gas - liquid chromatographyN. GOETZ, P.GATAUD and P. BOR:EL'Oreal Research Laboratories, 1 Avenue cle Saint-Germain , 93601 Aulnay-sous-Bois,France.Analyst, 1979, 104, 1062-1069.Determination of Small Amounts of Nickel in Organic Matter byAtomic-absorptnon SpectrometryReport prepared by the Metallic Impurities in Organic MatterSub-committeeThe method for the determination of nickel in organic matter is based onthe atomic-absorption procedure already shown to be applicable to the deter-mination of lead; both nickel and lead can therefore be determined on thesame analytical sample. Organic mattter is destroyed by wet oxidation inthe presence of sulphuric acid. After dilution, the nickel (and lead) arerecovered from the aqueous acid solution by extraction of the complexesformed with ammonium tetramethylenedithiocarbamate complexes into 4-methylpentan-2-one. The nickel content is determined by aspirating theextract into an air - acetylene flame,, measuring the atomic absorption at232.0 nm and comparing the resulting signal with a calibration graph preparedby submitting standard nickel solutions to an identical procedure.It isstressed that practice in sample prepa,ration must be thorough before resultscan be reliable.Keywords : Nickel determination ; wet oxidation ; ammonium tetramethylene-dithiocarbamate ; atomic-absorption spectrometryANALYTICAL METHODS COMMITTEEThe Chemical Society, Burlington House, London, WlV OBN.Analyst, 1979, 104, 1070-1074November, 1979 THE ANALYST xi~~ ~ I TREATISE ON ANALYTICAL CHEMISTRY voi.2 Part 1:__Theory and Practice 2nd Ed.I edited by I.M. Kolthoff, University of Minnesotaand P.J. Elving, University of MichiganA complete and definitive source of information for all analytical chemists, designed tostimulate fundamental research in pure and a plied analytical chemistr . Coverage includesaspects of classical and modern analytical clemistry, and the scientiic and instrumentalfundamentals of analytical methods.0471 05510 7 approx. 770 pages In Press approx. $62.45/f 28.65FOUNDATIONS OF CHEMICAL ANALYSISby 0. Budevsky, Faculty of Pharmacy, Academy of Medicine, Sofia, BulgariaThis concise yet comprehensive introduction makes plain the theory of chemical analysis bymeans of a new and unusual teaching approach.By reinforcing chemical explanations withnumerous raphs, Dr. Budevsky presents a visual overview of equilibria, and particularly intitrimetry, %ereby showing the behaviour of chemical species i n solution, as seen from theevidence of the equilibrium constant as a measure of reaction. The treatment of acid-baseequilibria i s highly original and detailed, and has special significance for acid-base titrimetryin non-aqueous media, and facilitates calculation of titration curves.These new and simple methods in teaching will help the reader’s understanding o f topicspresented. Numerous worked examples in practical analysis are an additional bonus towardscomprehension, and valuable chemical data are tabulated i n Appendixes I-Vli.(EllisHorwood Series in Analytical Chemistry; Editors: Dr. R.A. Chalmers, and Dr. Mary Masson,University of Aberdeen)085312 113 3 372 pages September 1979 $45.25/f18.50Published by Ellis Horwood itd., Chichester, and distributed by lohn Wiley & Sons Ltd.INTRODUCTION TO MODERN LIQUIDCHROMATOGRAPHY 2nd Ed.by L.R. Snyder, Technicon lnstrurnents Corporation;and J.J. Kirkland, €.I. du Pont de Nemours & Co.A completely rewritten edition that incorporates the latest developments in the practicalapplication of liquid chromatograpy. It covers the basics of LC, the six methods and theirapplications, and various specialized areas, and provides material for in-depthcomprehension of how HPLC i s performed, what the necessary materials are, and possibleapplications.0471 03822 9 approx. 848 pages In Press approx.$39.25/f18.00ORGANICS ANALYSIS USING GASCHROMATOGRAPHY/MASS SPECTRQMETRYby W.L. Budde and J.W. Eichelberger, Environmental Monitoring and Support Laboratory,US Environmental Protection Agency, CincinattiA practical guide for scientists, managers, and technicians who perform or contract toperform analyses of organic pollutants in water, air, sediment, or fatty tissue samples. Itemphasizes quality control and the versatility of the powerful gas chromatography/massspectrometry technique.Published by Ann Arbor Science Inc., and distributed by john Wiley & Sons Ltd.0250 40318 8 270 pages October 1979 $22.00/€11~ 3xii SUMMARIES OF PAPERS IN THIS ISSUEMicrobiological Assay of Avoparcin in AnimalFeeds and Pre-mixesNovember, 1979Report prepared by the Antibiotics in Animal Feedingstuff sSub-Committee.A microbiological method for the determination of avoparcin in animal feeds(10-20 mg kg-l; lowest limit of determination 2 mg kg-l) and pre-mixes(20 g kg-l) is described.The method has been submitted to collaborativestudy by a UK Committee and six other EEC Member States, and gave meanrecoveries of 92.8, 104.2 and 101.8%, with standard deviations 17.6, 14.0and 14.6% absolute from chick mash, pig meal and pre-mix, respectively. Inthe method, the sample is extracted with a mixture of acetone, water andhydrochloric acid, and the antibiotic activity of the clarified extract is deter-mined by measuring the diffusion of avoparcin in an agar medium inoculatedwith Bacillus subtilis.Keywords ; Avoparcin assay ; antibiotics ; animal feeds ; microbiological assayANALYTICAL METHODS COMMITTEEThe Chemical Society, Burlington House, London, W1V OBN.Analyst, 1979, 104, 1075-1082.Fast and Simple Polarographic Method for the Determination of Freeand Total Sulphur Dioxide in Wines and Other Common BeveragesShovt PaperKeywords : Direct-pulse polarography ; sulphur dioxide determination ; wineanalysisP.BRUNO, M. CASELLI, A. DI FANO and A. TRAIN1Istituto di Chimica Analitica dell'Universit2, Via Amendola 173, 70126, Bari, Italy.Analyst, 1979, 104, 1083-1087.Direct Differential-pulse Polarographic Determination of Mixturesof Food Colouring Matters, Chocolate Brown HT,Tartrazine and Green SShort PaperKeywords : Food colouring matters ; diffevential-pulse Polarography ; ChocolateBrown H T ; tartrazine; Green SA.G. FOGG and K. S . YO0Chemistry Department, Loughborough IJniversity of Technology, Loughborough,Leicestershire, LEll 3TU.Analyst, 1979, 104, 1087-1090November, 1979 THE ANALYST xiii* Same day despatch on all orders receivedbefore 3 p.m. * 7-day repair service. * Hire service for seminars etc.SEND NOW FOR BROCHUREPRESTONS TIMER DIVISIONCapitol House, Churchgate, Bolton, Lancs BL1 lLYReg in England No 541349 Tel 27035 Telex 63221F l e a s e send me your literature on timers I for industry and sport, without obligation.I Name__p-p- ~ ~ - ~ - -~I PositionI Company--------w--II 1II TA/Hb , ' AddressI- ___-I ~-; PRESTONS TIMER DIVISION ;I POST TO:- PRESTONS TIMER DIVISION, .! Capitol House, Churchgate, Bolton, Lancs.BL11LY. ,'IIIII Address mI II ILimm-mmmmm=m-m=m= Jr i i i i = w m i m = m = i = m =II I enclose f 1 NameTo: May & Baker Ltd (Wail-planner Offer)Essex House, Station Road, Upminster, Essex RM14 2JTPlease send wall-planners (1980/81) at f l eachpostal orderlcheque payable t o May& Baker Ltd I(please print clearly) LA160xiv SUMMARIES OF PAPERS I N THIS ISSUE3- (2'- Thiazolylazo)-2,6-Diaminotoluene as a Selective and SensitiveReagent for the Spectrophotometric Determination of PalladiumNovember, 1979Short PapevKeywovds 3- (2 '-Thiazolylazo) -2,6-diaminotoluene veagent ; palladium deter-mination ; spectvophotometvyF.GARCIA MONTELONGO, V. GONZALEZ DIAZ and C. R. TALL0Department of Analytical Chemistry, University of La Laguna, Tenerife, CanaryIslands.Analyst, 1979, 104, 1091-1094.GONZ~LEZRapid Spectrophotornetric Method for the Determinationof Arsenic(II1) in Borate GlassesShovt PapevKeywovds : Arsenic( 111) detevmination ; spectvophotometvy ; borate glassesSARYOO PRASAD SINGH, R,4M PYARE, GUR PRASAD and P. NATI-IDepa.rtment of Ceramic Engineering, Institute of Technology, Banaras HinduUniversity, Varanasj-22 1005, India.Analyst, 1979, 104, 1094-1097.An Improvement in the Determination of Available Lysinein Carbohydrate-rich SamplesCommunicationKeywords : Lysine detevmination ; cavbohydrate-rich samples ; 2,4,6-tvini-tvobenzenesulphonic acidR. J. HALL and K. HENDERSONMinistry of Agriculture, Fisheries and Food, Agricultural Development and AdvisoryService, Analytical Chemistry Department, Government Buildings, Kenton Bar,Newcastle upon Tyne, NE1 2YA.Analyst, 1979, 104, 1097-1 100.Calibration of Proposed Wet- combustion Procedure withDry- combustion Method for the Determination of TotalCarbon in SoilsComunuTaicationKeywords : Chromic acid digestion; soil ovganic cavbon determination ; dvycombustionR. C. DALALDepartment of Soil Science, Waite Agricultural Research Institute, Glen Osmond,South Australia 5064.Analyst, 1979, 184, 1100-1101