February, 1983 SUMMARIES OF PAPERS IN THIS ISSUESummaries of Papers in this IssueGlassy Carbon Tubes in Electrothermal Atomisation -Atomic-absorption SpectrometryPreliminary results are presented on the use of glassy carbon tubes of standarddimensions for electrothermal atomisation - atomic-absorption spectrometry.In comparison with pyrolytically coated graphite tubes, the glassy carbontubes show similar limits of detection provided that the same atomisationtemperature can be realised. Glassy carbon tubes promise the followingadvantages : more uniform heating ; resistance against chemical attack ; a life-time of several thousands firings ; and a remarkably constant sensitivity.Keywords : Glassy carbon ; electrothermal atomisation ; atomic-absorptionspectrometryLEO de GALAN, MARGARETHA T.C. de LOOS-VOLLEBREGT andRENS A. M. OOSTERLINGLaboratorium voor Analytische Chemie, Technische Hogeschool, Jaffalaan 9,2628 BX Delft, The Netherlands.Analyst, 1983, 108, 138-144.Intensities of Some Spectral Lines from Hollow-cathode LampsThe relationship between spectral line intensity I and discharge currenti is examined as part of an investigation of low pressure (1-20 Torr) hollow-cathode discharges in neon, for various cathode dimensions. An equation,I = Ai (1 + Ci)/(l + Bi), deduced by balancing likely excitation and de-excitation processes, can be fitted within the limits of experimental accuracy tomeasured I vevs'sus i graphs. Here, A depends on one-stage excitation, C on therelative importance of two- and one-stage excitation, and B on the relativeimportance of collisional and radiative de-excitation.The values of B and Cfor individual lines, and their dependence upon pressure and upon cathodedimensions, together with the possible role of self-absorption, are discussed.Keywords ; Hollow cathodes ; excitatiop processes ; spectral intensity ; neonCHRISTOPHER HOWARD, MARJORIE E. PILLOW and EDWARD B. M.STEERSSchool ofN7 8D8.Applied Physics, The Polytechnic of Northand DONALD W. WARDCathodeon Ltd., Nuffield Road, Cambridge, CB4 1TF.London, Holloway, London,iiiAnalyst, 1983, 108, 145-152iV SUMMARIES OF PAPERS I N THIS ISSUEFlow Injection Sample Introduction Methods forAtomic-absorption SpectrometryFebruary , 1983The essential features of flow injection analysis are described and the use offlow injection methodology for sample introduction for flame atomic-absorp-tion spectrometry is briefly reviewed.A flow injection analogue of thestandard additions method has been devised and applied to the analysis ofchromium in some BCS standard steels. The results showed good agreementwith the certificate values. The use of a concentration gradient formingmixing chamber to provide a novel method of rapid, single-standard cali-bration is described and the results of preliminary experiments with magnesiumshow the method to be viable, The potential usefulness of both methods iscritically evaluated.Keywords : Flow injection ; atomic-absorption spectrometry ; standard additionsmethod ; sample introduction ; concentration gradient generatorJULIAN F.TYSON, JOHN M. H. APPLETON and AHYAR B. IDRISDepartment of Chemistry, Loughborough University of Technology, Loughborough,Leicestershire, LE11 3TU.Analyst, 1983, 108, 153-158.Development Progress in Plasma Source Mass SpectrometryDevelopment work in the application of the inductively coupled plasma toplasma source mass spectrometry is described. Preliminary results obtainedunder continuum (or bulk plasma) sampling conditions are illustrated andcompared with previously published boundary layer sampling work. Thetechnique is now shown to be viable for multi-element analysis of complexsamples.Keywords : Plasma source mass spectrometry ; inductively coupled plasma ;continuum (or bulk plasma) sampling mode ; multi-element trace analysisALAN R.DATEInstitute of Geological Sciences, 64/78 Gray’s Inn Road, London, WClX 8NG.and ALAN L. GRAYDepartment of Chemistry, University of Surrey, Guildford, Surrey, GU2 5XH.Analyst, 1983, 108, 159-165.A Pneumatic Recirculating Nebuliser System for SmallSample VolumesThe nebuliser spray chamber described generates an aerosol, for use with aninductively coupled plasma, on as little as 1 ml of sample solution for over10 min. The nebuliser has direct application to inductively coupled plasmaoptical emission spectroscopic analysis in those instances where economy ofsample solution is important. The performance of the nebuliser spraychamber was tested and it was found that the sensitivity and precision are asgood as those obtained with a conventional nebuliser system.Memory effectsare readily overcome by including a system that allows rapid, thoroughflushing and flooding of the spray chamber.Keywords : Inductively coupled plasma ; optical emission spectrometry ;pneumatic nebuliserPETER HULMSTONAnalytical Chemistry Branch, Chemistry Division, MOD(PE) , Atomic WeaponsResearch Establishment, Aldermaston, Berkshire, RG7 4PR.Analyst, 1983, 108, 166-170February , 1983 SUMMARIES OF PAPERS IN THIS ISSUETrace-metal Determinations in Concentrated ElectrolyteSolutions-a Comparative StudyVThe results presented here are typical of those obtained during an extendedstudy of methods for determining trace amounts of cationic contaminants inthe two most commonly used dry-cell electrolytes (aqueous 7 M solutions ofzinc chloride and potassium hydroxide).The results show that when dilutioneffects are taken into account there is little to choose between inductivelycoupled plasma atomic-emission and flame atomic-absorption spectroscopyas far as.sensitivity is concerned but the precisions of results obtained from adirect reading (simultaneous) inductively coupled plasma spectrophotometerare significantly better than those obtained by flame atomic absorption, andthe time taken to analyse samples for a number of elements is greatly reducedby the simultaneous inductively coupled plasma method.At lower levels, significant reductions in sensitivity of the electrothermalatomic-absorption technique, amounting to 3-4 orders of magnitude in someinstances, are caused by the presence of large excesses of these electrolytes,but where ultimate sensitivity is of less importance than sample throughputthis technique has advantages over electroanalytical techniques.Wheresensitivity, high precision and/or low capital costs are the prime considerationthen electroanalytical techniques have much to offer.Keywords : Direct current plasma ; inductively coupled plasma ; atomic-absorption spectrometry ; trace elements ; electrolyte solutionsPETER R. SKIDMORE and SUSAN S . GREETHAMBritish Ever Ready Company Ltd., Group Technical Centre, St. Ann’s Road,Tottenham, London, N16 3TJ.Analyst, 1983, 108, 171-177.Simultaneous Multi- element Analysis by Carbon FurnaceAtomic-emission SpectrometryThe application of carbon furnace atomic-emission spectrometry (CFAES) tosimultaneous multi-element analysis has been investigated using a direct-reading spectrometer system.A computer-controlled wavelength modulationsystem employing a quartz refractor plate is used to provide automatic back-ground correction in both the single and multi-element modes. Detectionlimits obtained using a three-step square-wave modulation waveform with thissystem are comparable to those previously obtained using the rotating sectormethod of modulation. The linear range of calibration graphs has beenextended to 4-5 orders of magnitude by measurement of emission intensitiesoff the centre of the line profile.The potential of CFAES as a technique forsimultaneous multi-element analysis is demonstrated by the determinationof trace elements in NBS standard reference materials and orange and pine-apple juice samples.Keywords : A tomic-emission spectrometry ; electrothermal atomisation ; simul-taneous multi-element analysis ; wavelength modulation ; fruit juiceJOHN MARSHALL, DAVID LITTLEJOHN and JOHN M. OTTAWAYDepartment of Pure and Applied Chemistry, University of Strathclyde, 285 CathedralStreet, Glasgow, G1 1XL.JAMES M. HARNLYNutrient Composition Laboratory, Beltsville Human Nutrition Centre, US Depart-ment of Agriculture, Beltsville, MD 20705, USA.NANCY J. MILLER-IHLI and THOMAS C. O’HAVERDepartment of Chemistry, University of Maryland, College Park, MD 20742, USA.A ~ z a l y ~ t , 1983, 108, 178-188vi SUMMARIES OF PAPERS IN THIS ISSUEDetermination of Trace Impurities in Sodium Coolant from a FastBreeder Reactor by Inductively Coupled Plasma Atomic-emissionSpectrometryFebruary , 1983Trace impurities in samples of the liquid sodium coolant from the DounreayFast Reactor are determined by inductively coupled plasma (ICP) atomic-emission spectrometry of vacuum distillation residues.A 72-channel vacuumspectrometer with a l-kW argon plasma source, fed by a coaxial capillarynebuliser, simultaneously measures 59 elements with a precision varying from(1% at concentrations 20 times the detection limit to 30% a t detectionlevels. The ICP torch box is enclosed in a fume-cupboard fitted with afiltered extract system to allow safe handing of the radioactive solutions.Comparisons of some results have been made with spark-source mass spectro-metry, d .c.arc emission spectrography, neutron-activation analysis andatomic-absorption spectrometry.Keywords : Liquid sodium ; sodium distillation ; inductively coupled plasma ;atomic-emission spectrometry ; impurity determinationTHOMAS BERRY, KENNETH C. MACLEOD, ALISTAIR C. CHRISTIEand JAMES A. CUNNINGHAMUnited Kingdom Atomic Energy Authority (Northern Division) , Dounreay NuclearPower Development Establishment, Thurso, Caithness, KW14 7TZ.Analyst, 1983, 108, 189-195.Determination of Trace Elements in Biological Materials Using aHollow-cathode Discharge: Comparative Study of Matrix EffectsAn emission source that does not appear to be significantly prone to matrixeffects is the hollow-cathode discharge.In order to elucidate its effectivepotential a number of elements (aluminium, arsenic, calcium, copper, galliumand zinc) were determined in the presence of various compounds (ortho-phosphoric acid, sodium nitrate and potassium nitrate) over a wide range ofconcentrations and internal ratios. The same elements were determined inliquid samples resulting from mineralisation of biological materials (kidney,liver, brain and blood of mice). The results showed that the hollow-cathodeemission source is affected by this type of interference to a lesser extentthan atomic-absorption spectrometry and arc-emission spectrography.Keywords : Hollow-cathode discharge ; emission spectroscopy ; atomic-absorp-tion spectrometry ; matrix effectsSERGIO CAROLI, ORESTE SENOFONTE and PIETRO DELLE FEMMINEIstituto Superiore di Sanith, 299 Viale Regina Elena, 00161 Rome, Italy.Analyst, 1983, 108, 196-203February, 1983 SUMMARIES OF PAPERS IN THIS ISSUEA Critical Comparative Study of Atomic- spectrometric Methods(Atomic Absorption, Atomic Emission and Inductively CoupledPlasma Emission) for the Determination of Strontium inBiological MaterialsviiAs part of a general research plan, aimed at establishing tolerable doses ofstrontium and its distribution in selected soft tissues of rats and hamsterstreated with stable strontium, a comparative study on the analytical per-formance of flame atomic absorption, flame atomic emission and inductivelycoupled plasma (ICP) emission for biological strontium assays, especially inblood serum, has been carried out.Optimum conditions for the variousmethods were established and analytical performance characteristics wereevaluated for each method in terms of limits of detection, dynamic range,selectivity and precision attainable using the same basic instrument (thePerkin-Elmer ICP/5000),ICP emission spectrometry appeared to be the best method as it provides asensitivity of about 100 times better than the next most sensitive method, alinear calibration graph over five orders of magnitude, good precision in realsample analysis and virtual absence of spectral or chemical interferences(although nebulisation and transport effects have to be allowed for) fromthose elements and organic matrices common in biological materials.Adinitrogen oxide - acetylene flame, in the presence of a sodium contentapproximating the blood sodium content, increases sensitivity and selectivitywhen compared with an air - acetylene flame, flame emission being aboutfour times more sensitive than flame atomic absorption for both flames.Results for the determination of strontium in blood serum, brain and liverof rats and hamsters treated with stable strontium are also reported.Keywords : Strontium determination ; biological materials ; jlame atomic-absorption spectrometry ; flame atomic-emission spectrometry ; inductivelycoupled plasma emission spectrometryALFRED0 SANZ-MEDEL and ROSA RODRIGUEZ ROZADepartment of Analytical Chemistry, Faculty of Chemistry, University of Oviedo,Oviedo, Spain.and CONCHITA PEREZ-CONDEDepartment of Analytical Chemistry, Faculty of Chemistry, Universidad Com-plutense, Madrid, Spain.Analyst, 1983, 108, 204-212.Investigations on Atomisation Mechanisms of Volatile Hydride-forming Elements in a Heated Quartz Cell. Part 1.Gas-phaseand Surface Effects; Decomposition and Atomisation of ArsineThe atomisation of gaseous hydrides in a heated quartz cell is not caused bya thermal decomposition but by collision with free hydrogen radicals. Theseradicals are formed in a reaction with oxygen a t temperatures above 600 “C.In a “clean” environment, the concentration of radicals is well above theequilibrium concentration because their formation is a much faster processthan their recombination.Several materials, however, can catalyse radicalrecombination and therefore have a depressing effect on the observed signal.In the absence of hydrogen, arsine is not atomised but thermally decomposed,probably with the formation of As, and As,.Keywords : A tomic-absorption spectrometry ; hydvide generation technique ;atomisation mechanisms ; arsine atomisation and decomposition ; hydrogenradicalsBERNHARD WELZ and MARIANNE MELCHERDepartment of Applied Research, Bodenseewerk Perkin-Elmer & Co. GmbH,D-7770 ftlberlingen, Federal Republic of Germany.Analyst, 1983, 108, 21 3-224... Vlll SUMMARIES OF PAPERS IN THIS ISSUEA New Design of Graphite Furnace for Rapid Cycle ElectrothermalAtomisation - Atomic-absorption SpectrometryFebruary, 1983The design and performance of a new furnace developed for electrothermalatomisation - atomic-absorption spectrometry is described.The furnaceconsists of a segmented graphite rod. Sample solutions may be atomiseddirectly from the rod without prior drying and pyrolysis, with the resultthat the time interval between sample injections is reduced to <30 s. Theperformance of the segmented-rod atomiser with direct sample atomisationwas investigated for the determination of silver, gold, aluminium, bismuth,cadmium, chromium, copper, mercury, manganese, lead, vanadium and zincin complex matrices containing salts and organic material.In all instancessensitivities comparable to those associated with conventional furnacesystems were achieved. The coefficient of variation ranged from 4.0% forcadmium in 0.1 M nitric acid to 9% for gold in 1% sodium chloride solution.Keywords : A tomic-absorption spectrometry ; electyothermal atomisation ; seg-mented graphite rod ; direct atomisationMOHAMMAD-HOSSEIN BAHREYNI-TOOSI and JOHN B. DAWSONDepartment of Medical Physics, General Infirmary, Leeds, LS1 3EX.Analyst, 1983, 108, 225-234.Determination of Lead in Blood by Flame Atomic-fluorescenceSpectrometryA simple, rapid method is described for the determination of lead in blood.Dilution 1 + 4 with Triton X is the only sample preparation required andmeasurements are carried out using a purpose-built atomic-fluorescencespectrometer with a nitrogen-separated air - acetylene flame. The prepara-tion and operation of the lead electrodeless discharge lamps used as theexcitation source have been optimised by a ten-factor Simplex procedure. Adetection limit of 6 pg 1-l has been achieved for lead in aqueous solution. Nosignificant chemical interferences were observed from the major constituentsof the blood matrix and a second continuum source is used to achieve auto-matic background correction for scattered radiation. Aqueous lead standardsare used for calibration. Accuracy was established by satisfactory comparisonwith values reported for quality control blood samples.Keywords : Flame atomic-fluorescence spectrometry ; lead determination ; bloodanalysis ; electrodeless discharge lampsPREM R. STHAPIT and JOHN M. OTTAWAYDepartment of Pure and Applied Chemistry, University of Strathclyde, CathedralStreet, Glasgow, G1 1XL.and GORDON S. FELLDepartment or' Clinical Biochemistry, Royal Infirmary, Glasgow, G4 OSF.. - . - ^ - - ~ - - --- ^.