iv SUMMARIES OF PAPERS I N THIS ISSUE November, 1979Summaries of Papers in this IssueDirect Analysis of Solids by Atomic -absorption SpectrophotometryA ReviewSummary of ContentsIntroductionPrevious literatureInstrumentsAtomisation methodsAtomisation in flame cellsAtomisation of undispersed powdersAtomisation of powders suspended in solid dispersing agentsAtomisation of powders suspended in liquid dispersing agentsAtomisation of powders sampled by arcing or sparking and suspendedAtomisation in tube or crucible cells, and in cells in the form of a T, invertedAtomisation from rod, strip or braid cellsAtomisation from an electrically heated rod or a closed tube placed in aAtomisation in d.c. or a.c. arcsAtomisation by cathodic sputteringAtomisation by laser or discharge lampsOther atomisation methodsConclusionin gaseous dispersing agentsT or +flameAtomisation of air- and water-suspended solidsReactions in atomisation cellsThermochemistryKineticsInterferencesSamples, sampling, sampling errors anti sample preparationStandards, standardisation and techniques of measurementAccuracy and precisionTime of analysisContamination controlApplicationsAppendixConclusionReferencesKeywovds : Review ; solids analysis ; atomic-absovption spectvophotometryF. J.LANGMYHRDepartment of Chemistry, University of Oslo, Oslo 3, Norway.Analyst, 1979, 104, 993-1016Vi SUMMARIES OF PAPERS I N THIS ISSUEDetermination of Lead, Bismuth, Zinc, Silver and Antimony inSteel and Nickel-base Alloys by Atomic-absorption SpectrometryUsing Direct Atomisation of Solid Samples in a Graphite FurnaceNovember, 1979A fast and simple method of determining lead, bismuth, zinc, silver andantimony in steel and nickel-base alloys has been developed using unmodifiedcommercial atomic-absorption equipment. The method is based on thedirect atomisation of solid metal samples in a graphite furnace.The samplescan weigh between 1 and 20 mg, but test results are influenced by the shapeof the samples. Calibration graphs havebeen drawn using steel samples with known contents. Practical contentranges, e.g., lead 0.03-150 pgg-l and bismuth 0.03-6 pgg-l, and lowdetection limits, down to 0.02 pg 8-1, have been obtained by selecting suitablelines of analysis. The relative standard deviation (1s) is approximately 6%of the content of all elements investigated throughout the stated range ofcontent.The time required for analysis is short, being about 6min for aduplicate determination.The matrix effects are very slight.Keywords ; Direct analysis of solid samples ; lead, bismuth, zinc, silver andantimony detevmination ; steel and nickel-base analysis ; atomic-absorptionspectrometry ; graphite furnaceSVENERIK BACKMAN and RUNE W. KARLSSONSandvik AB, 45-TMK, Fack, S-811 00 Sandviken, Sweden.Analyst, 1979, 104, 1017-1029.Extraction of Nanogram Amounts of Cadmium and Other Metals fromAqueous Solution Using HexamethyleneammoniumHexamethylenedithiocarbamate as the Chelating AgentA group of metals can be extracted from aqueous solution by using hexa-methyleneammonium hexamethylenedi thiocarbamate as the chelating agentand a mixture of 2,4-dimethylpentan-3-one and xylene as the organic phase.A description is given of a procedure fclr the determination of microgram andnanogram amounts of the nine metals silver, bismuth, cadmium, copper, nickel,lead, thallium and zinc in aqueous solution.The influence of a high content of iron and copper on the extraction isdescribed.Keywords A tomic-absorption spectvometry ; metal extraction ; nanogvamamounts of metals ; dithiocarbamate ch,elationA.DORNEMANN and H. KLEISTBayer AG, TVerk Gerdingen, AC-F Untersuchungslaboratorium, D 4150 Krefeld 11,FRG.Analyst, 1979, 104, 1030-1036November, 1979 SUMMARIES OF PAPERS I N THIS ISSUEDetermination of Microgram Amounts of Precious Metals UsingX-ray Fluorescence SpectrometryMicrogram amounts of noble metals were localised with ammonium sulphideon filter absorbent pads and in cellulose pellets for spectrometer counting.The Ka, lines of ruthenium, rhodium and palladium (tungsten tube) and theLcc, lines of osmium, iridium, platinum and gold (molybdenum tube) wereemployed in conjunction with a lithium fluoride (200) analysing crystal.Atthe 95% confidence level, detection limits of 1.0 pg (ruthenium, rhodium andpalladium) and 0.6 p g (osmium, iridium, platinum and gold) were observed for thepellet technique, with values of 0.6 and 0.2 pg, respectively, for the absorbent-pad method.The average coefficient of variation for the determination of10 p g of the seven metals studied was 6.5% for both sample presentations.No inter-elemental matrix interferences were observed among the noblemetals themselves. However, the presence of more than 200 pg of nickel orcopper reduced the slopes of the calibration graph by a constant factor of10% for the lighter metals, and amounts of more than 400 pg of the basemetals reduced the slopes by 20% for the heavier members. Good agree-ment was found between the X-ray fluorescence procedures and standardatomic-absorption methods in analysis of ore concentrates.Keywords : X-ray fluorescence spectrometvy ; precious metals ; absorbent-padtechnique ; cellulose-pellet techniquePAUL R. OUMO and EVERT NIEBOERDepartment of Chemistry, Laurentian University, Sudbury, Ontario, P3E 2C6,Canada.Analyst, 1979, 104, 1037-1049.viiX-ray Fluorescence Determination of Platinum and Palladiumin Platinum Concentrates Using a Solution TechniqueAn X-ray fluorescence solution technique for the determination of platinumand palladium in platinum-bearing material is described.Ruthenium hasto be removed prior to the measurement of the platinum and palladium.Mercury and thorium are used as internal standards. The method is preciseand is more rapid than the gravimetric method normally used.Keywords : X-ray fluorescence spectrometry ; platinum determination ;palladium determination ; mevcury and thorium internal standards ; platinumconcentrates2. CRUICKSHANK and H.C. MUNROJohannesburg Consolidated Investment Company Limited, Minerals ProcessingResearch Laboratory, P.O. Box 13017, Knights, Transvaal 1413, South Africa.Analyst, 1979, 104, 1060-1054.Determination of Iron(I1) in Rock, Soil and ClayA rapid and direct method for the determination of iron(I1) in silicates isdescribed. Redox processes frequently occurring during decomposition aresuppressed satisfactorily by limiting the reaction time to 10 s while main-taining the temperature a t 60-65 "C. Reproducible decomposition tempera-tures are achieved by mixing concentrated sulphuric and hydrofluoric acids(1 + 3 V / V ) in the reaction vessel. The coloured iron (11) - 1,lO-phenanthrolinecomplex is used in the spectrophotometric determination of the twovalency states of iron, iron(I1) directly and iron(II1) by difference aftersubsequent reduction by hydroquinone. Mean results of duplicates of theUSGS geological standards G-2, AGV-1 and BCR-1 are within 0.1% andthose for DTS-1 and PCC-1 within 0.3% of the quoted average valuesfor iron(I1) oxide.Keywords Iron(II) detevmination ; silicates ; hydrojZuoric acid decomposition ;spectrophotometryL. Th. BEGHEIJNDepartment of Soil Science and Geology, Agricultural University T47ageningen,P.O. Box 37, 6700 AA Wageningen, The Netherlands.Analyst, 1979, 104, 1055-1061