September, 19731 THE ANALYST ixCLASSIFIED ADVERTISEMENTSThe rate f o r classified advertisements i s 35p a line (or s$weequivalent of a line) with an extra charge of l o p for theuse of a Rox Number. Semi-displayed classifiedadvertisements aye f;4 for szngle-column inch.Copy for classified advertisements required not later thaRthe 18th of the month preceding date of Publication whichis on the 16th 01 each month. Advertasements should beaddressed to J Arthur Cook 9 Lloyd Square, London,W C l X 9BA. ‘Tel.: 01-837 k31.5WANTEDLiterature on mctnllurgical analysis, 19th arid early 20th century,particularly iron and steel. W. Is. Clark?, 1 A1cestc.r Roxl, Stiidlcy,Warks. D80 7AN.Senior ControlAnalystA vacancy has arisen ir? the Analytical ControlLaboratory of Geigy Pharmaceuticals for theposition of Senior Control Analyst.The scope of the position embraces the dailycontrol of all Analytical matters emanating fromthe entire Control Section of the AnalyticalLaboratory. Reportability will be directly to theHead of the Analytical Department andresponsibility will be fQr the most effectiveprofessional use of four sections of theLaboratory, each separately controlled a tGraduate, or equivalent, level, assessing qualityof raw materials, bulk and finished goods againstapproved specifications and for specialinstrumentational analysis.Basic product scopeis a comprehensive range of excipients andactive ingredients, together with compoundedPharmaceutical dosage forms.The requirements are for a mature, well-qualifiedGraduate, probably of a chemical orpharmaceutical discipline, who has been exposedto a wide range of pharmaceutical analyticaltechniques, probable age range 25/35.Thecandidate will have several years‘ experience inthe Pharmaceutical Analytical area, with a desireto exploit potential for further career advancement,particularly in a more administrative direction.Attractive conditions of service, which includean excellent contributory pension scheme, areconsistent with the international reputation ofthe Company and assistance will be given withrelocation expenses where appropriate.Please apply in writing giving brief details of your age, qualifications and experience to:The Personnel Manager, GEIGY PHARMACEUTICALS, Hurdsfield Industrial Estate, Macclesfield S K l O 2LYPlease mentionI THE ANALYSTwhen replying to advertisementsBINDINGHave your back numbers of The Analystbound in the standard binding case.Send the parts and the appropriateindex(es) together with a remittancefor f2.40 to :HEFFER’S PRINTERS LIMITEDCAMBRIDGE, ENGLANSUMMARIES OF PAPERS I N THIS ISSUE [September, 1973The Determination of VoIatile Metal Chelates by Using aMicrowave- excited Emissive DetectorA microwave-excited emissive detector operated a t atmospheric pressurehas been used in conjunction with gas chromatography in order to achievethe separation and determination of various metal chelates of acetylacetoneand trifluoroacetylacetone.The operating parameters have been optimisedand the limits of detection and degrees of selectivity evaluated.The proposedmethod is both selective and very sensitive and can also confirm the presenceof a particular metal.R. M. DAGNALL,Biochemistry Division, Huntingdon Research Centre, Huntingdon, PE18 6ES.T. S. WEST and P. WHITEHEADChemistry Department, Imperial College of Science and Technology, London,SW7 2AY.Analyst, 1973, 98, 647-654.The Determination of Trace Amounts of Barium in CalciumCarbonate by Atomic-absorption SpectrophotometryBarium present a t the 1 to 20 p.p.m. level in calcium carbonate isseparated from the calcium matrix by co-precipitation on a lead sulphatecarrier. The lead sulphate - barium sulphate precipitate is dissolved in anammoniacal solution of ethylenediaminetetraacetic acid disodium salt andthe barium in the resulting solution is determined by atomic-absorptionspectrophotometry by using a nitrous oxide - acetylene flame and the atomicline a t 553.6 nm.The method ovcrcomcs interferences that occur in the atoiiiic-absorpti~)nspectropl-iotometric determination of barium in the presence of calcium.F.J. BAN0John & E. Sturge Limited, Lifford Chemical Works, Kings Norton, Birmingham,B30 3JW.Analyst, 1973, 98, 655-658.Spectrophotometric and Chelatometric Determination of Iron(II1)with 3- Hydroxypyridine-2- thiol3-Hydroxypyridine-2-thiol can be satisfactorily used in the spectroplioto-metric and chelatometric determination of iron(lT1). With the prescribedmethods the determination can be made over a wide pH range withoutinterference from many anions and cations. Structures are suggested forthe complexes formed.MOHAN KATYALSt.Stephen’s College, Delhi-7, India.Miss VEENA KUSHWAHA and R. P. SINGHDepartment of Chemistry, Delhi University, Delhi-7, India.Analyst, 1973, 98, 659-662.Assay of Micro-scale Amounts of Hydroperoxide and of Iodinein Aqueous Non-ionic Surfactant Solutions by aSpectrophotometric MethodAn iodimetric - ultraviolet spectrophotometric method has been developedfor the quantitative determination of trace concentrations of hydroperoxide(down to Itinvolves a simple extrapolation procedure based on the kinetics of iodinefading in these systems. This method was also applicable to macro-scaleamounts when the classical titrimetric method could not be used.Hydrogenperoxide and hydroperoxides of some polyethylene glycols, in the presence, of Cetomacrogol 1000, gave reproducible results that were in good agreementwith the results obtained by use of the titrimetric method.E. AZAZ, M. DONBROW and R. HAMBURGERPharmacy Department, School of Pharmacy, Hebrew Tlniversity of Jerusalem,Jerusalem, P.O.B. 12065, Israel.M) in the presence of etheric non-ionic surface-active agents.Analyst, 1973, 98, 663-672xii SUMMARIES OF PAPERS I N THIS ISSUEObservations on the Use of 2,4,6-Trinitrobenzenesulphonic Acidfor the Determination of Available Lysine in AnimalProtein ConcentratesThe determination of available lysine in proteins by their reactions with2,4,6-trinitrobenzenesulphonic acid has been examined in relation to thepreparation of the sample, the conditions of the reaction, the hydrolysis of thetrinitrophenylated protein and the effects of other amino-acids and relatedcompounds.From these observations a revised method is proposed for therapid routine screening of animal protein concentrates used in animal feeds.With the use of DL-lysine as a standard instead of etrinitrophenyllysine andwith a simplified hydrolysis procedure, the technique is suitable for examiningcomparatively large numbers of samples. Interference by other amino com-pounds is slight, except that by cadaverine, hydroxylysine and ornithine.Results are given for the levels of available lysine in a range of animalproteins, which compare closely with values obtained by the Carpenterprocedure in which l-fluoro-2,4-dinitrobenzene is used.R.J. HALL, N. TRINDER and D. I. GIVENSMinistry of Agriculture, Fisheries and Food ; Agricultural, Development and AdvisoryService, Government Buildings, Kenton Bar, Newcastle upon Tyne, NE1 2YA.Analyst, 1973, 98, 673-686.'[September, 1973Quantitative Determination of the Enantiomeric Purity ofSynthetic PyrethroidsPart I. The Chrysanthemic Acid MoietyClirysanthemic acid is liberated by hydrolysis of the pyrcthroid underbasic conditions and is made to react with (+)-cc-methylbenzylamine via theacid chloride. Complete separation of diastereoisomeric amides derived fromthe (+) and (-) forms of both cis- and tvans-chrysanthemic acids can beobtained by gas chromatography on a 50-m x 0-25-mm glass capillarycolumn coated with FFAP (free fatty acid phase).No racemisation or kineticresolution takes place during the reaction sequences. The method is suitablefor the analysis of bioresmethrin, bioallethrin, tetraniethrin and otherinsecticidal chrysanthemates.F. E. RICKETTThe Cooper Technical Bureau, Uerkhamsted, Hertfordshire.Analyst, 1973, 98, 687-691.Carbon Tetrachloride as a Possible Source of Interference DuringFumigant Residue AnalysisThe contamination of acetone with an impurity corresponding to carbontctrachloride on two different gas-chromatographic columns is described. 1 thas been shown that this contamination could be caused by carbon tetra-chloride in the laboratory atmosphere, which possibly arises from the useof aerosol propellent cans for spraying thin-layer chromatograms.P.B. BAKER, J. E. FARROW and R. A. HOODLESSDepartment of Trade and Industry, Laboratory of the Government Chemist, CornwallHouse, Stamford Street, London, SE1 9NQ.Analyst, 1973, 98, 692-693.The Use of a Laser for Cutting Bone SamplesPrior to Chemical AnalysisShort PapevJ. S. HISLOP and A. PARKER,4nalytical Sciences Division, Atomic Energy Research Establishment, Harwell,Ridcot, Berkshire,Analyst, 1973, 98, 694September, 19731 THE ANALYST xiiiTR AC E ELEMEN TAN ALY S I SP RO BLEMS?Activation Analysis could be the answer. Thistechnique offers the advantages of high sensitivityand specificity, good accuracy and precision, even atsub-p.p.m.concentrations. A bulk analysis isobtained, often non-destructively. The maindlsadvantage (the need for a nuclear reactor) can beovercome by making use of the Activation AnalysisService provided by the Universities Research Reactor,If you would I ike to discuss your particular problem,or would like to receive further details, please contact:Dr. G. R. Gilmore (Activation Analyst),Activation Analysis Service,Universities Research Reactor,Risley,Nr. Warrington,Lancs.Phone: Warr. 32680,33114BUREAU OF ANALYSEDSAMPLES LTD.announce the issue of the followingNEW SAMPLESChemical StandardsNo. 384 Hycomax I11 PermanentMagnet Alloy (34% Co,4% Ti, 1% Nb)No. 388 Zircon (66% ZrO,, 33% SO2)Spectroscopic StandardsNos.66 1-665 High Phosphorus Engin-eering Irons containingincrements of C, Si, Mn, Sand PFor further details please write to :-NEWHAM HALL, NEWBY,MIDDLESBROUGH, TEESSIDE, ENGLANDTS8 9EAor Telephone 0642 37216SPECIALIST ABSTRACTJOURNALSpublished bySCIENCE AND TECHNOLOGY AGENCYAtomic Absorption and FlameEmission Spectroscopy AbstractsVol. 5, 1973, bimonthly €30X-Ray Fluorescence SpectrometryAbstractsVol. 4, 1973, quarterly €28Thin-Layer Chromatography AbstractsVol. 3, 1973, bimonthly €28Gas Chromatography-MassSpectrometry AbstractsVol. 4, 1973, quarterly €37Nuclear Magnetic ResonanceSpectrometry AbstractsVol. 3, 1973, bimonthly €30Laser-Raman Spectroscopy AbstractsVol. 2, 1973, quarterly €30X-Ray Diffraction AbstractsVol.1-2,1973, quarterly €30Neutron Activation Analysis AbstractsVol. 2 3 , 1973, quarterly €30Electron Microscopy AbstractsVol. 1, 1973, quarterly €30Liquid Chromatography AbstractsVol. 1, 1973, quarterly €30Electron Spin Resonance SpectroscopyAbstractsVol. 1 , 1973, quarterly €30Sample copies on request from:SCIENCE AND TECHNOLOGY AGENCY,3 HARRINGTON ROAD,SOUTH KENSINGTON,LONDON, SW7 3ES01-584 808xiv THE ANALYST [September, 1973- ---- - - - -melting point determinedWhen accurate thermometric measurements are required, it is necessaryto calibrate thermometers or other thermal analysis instruments usingreference temperatures.Reference temperatures are usually the solid-liquid transition temperaturesof some organic substances of high purity.Thermometric standards are those substances which not only have meltingtemperatures perfectly known from the literature, but which guarantee becauseof their very high degree of purity, a consistent agreement with the meltingtemperature stated. Using the most advanced techniques of purification suchas zone melting, Carlo Etba has made available to scientists the followingproducts which can be regarded as primary thermometric standards:+Solid-liquid transition temperaturep-NITROTOLUENE 51.54 "CNAPHTHALENE 80.27PHENANTHRENE 99.90BENZOIC ACID 122.35DIPHENYLACETIC ACID 148.00ANlSlC ACID 182.98CHLOROANTHRAQUINONE 209.03CARBAZOLE 245.34ANTHRAQUINONE 284.59All products are available in 2 g. vials.CCARLO ERBA DlVlSlONE CHIMICA I VIA CARL0 IMBONATI 24 I 20159 MILAN