JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 79R ATOMIC SPECTROMETRY UPDATE-CLINICAL AND BIOLOGICAL MATERIALS FOODS AND BEVERAGES Andrew Taylor* Supra-Regional Assay Service Metals Reference Laboratory Robens Institute of Industrial and Environmental Health and Safety University of Surrey Guildford Surrey UK GU2 5XH Simon Branch The Lord Rank Research Centre R. H. M. Research and Engineering Lincoln Road High Wycombe Buckinghamshire UK HP12 3QR Helen M. Crews Ministry of Agriculture Fisheries and Food Food Safety Directorate Food Science Laboratory Colney Lane Norwich UK NR4 7UQ David J. Halls Trace Element Unit Institute of Biochemistry Royal Infirmary Castle Street Glasgow UK G4 OSF Summary of Contents 1 Analysis of Clinical and Biological Materials 1.1. General Reviews and Comments 1.2.Sampling and Sample Preparation 1.3. Novel Techniques 1.4. Reference Materials Quality Control and Inter-laboratory Trials 1.5. Analysis of Body Fluids 1.5.1. Aluminium 1.5.2. Antimony 1.5.3. Arsenic 1.5.4. Barium 1.5.5. Bismuth 1.5.6. Boron 1.5.7. Bromine 1.5.8. Cadmium 1.5.9. Calcium 1.5.1 0. Chromium 1.5.1 1. Cobalt 1.5.1 2. Copper 1 3.1 3. Indium 1.5.14. Iron 1.5.1 5. Lithium 1.5.16. Lead 1.5.1 7. Magnesium 1.5.1 8. Manganese 1.5.1 9. Mercury 1.5.20. Molybdenum 1.5.21. Nickel 1.5.22. Platinum 1.5.23. Selenium 1.5.24. Silicon 1.5.25. Silver 1.5.26. Sulfur 1.5.27. Tellurium 1.5.28. Thallium 1.5.29. Tin 1.5.30. Titanium 1.5.31. Uranides 1.5.32. Vanadium 1.5.33. Zinc 1.5.34. Multi-element determinations and studies 1.6.1. Soft tissues 1.6.2.Brain 1.6.3. Bones and teeth 1.6.4. Stones 1.6.5. Hair 1.6. Analysis of Tissues * Review Co-ordinator to whom correspondence should be addressed.80R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 1.7. Marine Biology 1.8. Pharmaceuticals 1.9. Conclusions Table 1. Summary of Analyses of Clinical and Biological Materials 2 Analysis of Foods and Beverages 2.1 Sampling and Sample Preparation 2.1 .l. Direct determination of analytes 2.2 2.3 2.4 2.5 2.6 2.7 2 2.1.2. Preconcentration 2.1.3. Digestion 2.1.4. Slurry sampling Developments in Hydride Generation Techniques ). Speciation Studies . Developments in Methodology for Electrothermal Atomic Absorption Spectrometry . Developments in Methodology for Plasma Emission Spectrometry Developments in Methodology for Inductively Coupled Plasma Mass Spectrometry .Single and Multi-element Analyses of Foods 2.8.1. Aluminium 2.8.2. Mercury 2.8.3. Selenium 2.8.4. Vanadium .8. Progress on the Determination of Some Individual Elements 2.9. Characterization Studies 2.1 0. Reference Materials and Collaborative Trials Table 2. Summary of Analyses of Foods and Beverages The references included in this the eighth ASU under the heading of Clinical and Biological Materials Foods and Beverages are from 92/C339 to 93/C909. As noted last year there is now an increasing range of multi-element techniques being used and while important ICP-MS does not dominate as it once was suspected that it would. This year has seen a growth in the use of stable isotopes with measurements generally made by ICP-MS.However a particular development has been with accelerator MS for the determination of 26AI. This has provided for the first time a tracer for Al metabolism experiments. A symposium on speciation in biological analysis provided the stimulus to much new work particularly with As and Hg and many of the papers from the meeting are included in this review. Several of these and other papers made use of FI techniques a development which was enhanced by a new commercial FI system for AAS. Procedures for preconcentration either separate from or linked to the FI technique featured in a number of reports. Aluminium no longer stands out as the single element of greatest interest. As already seen there are many entries for As and Hg but the main features are the increased number of Se papers and the larger overall number of elements which have been covered.1. ANALYSIS OF CLINICAL AND BIOLOGICAL MATERIALS David J. Halls and Andrew Taylor Over the years there has been a continuing trend towards multi-element techniques and multi-element studies. Tech- niques such as ICP-MS XRF and PIXE are now well established. In the light of these developments this Update on Clinical and Biological Materials follows a somewhat different format to Updates on this subject in previous years. Sections on reviews sample preparation novel methods and reference materials remain as before but discussion on methods and studies is classified according to sample type body fluids sub-divided according to element; tissues sub-divided into soft tissues brain bone and teeth; stones and hair; marine biology and pharmaceuticals.The section on body fluids is sub-divided according to element. Table 1 lists details of papers and conference reports covered in this review year. 1.1. General Reviews and Comments Several relevant reviews were given at the XXVII-CSI Post- Symposium on Speciation of Elements in Environmental and Biological Sciences in Loen Norway 1991 and most were published later in The Analyst. Van Loon and Barefoot (9214099) presented an overview on analytical methods for speciation focusing on extraction techniques electrochemical methods coupled techniques flow injec- tion and on the elements most frequently studied. Nieboer (92/C802) dealt especially with speciation for toxicology in particular the different toxic effects of Cr and Ni com- pounds.The need for speciation and a discussion of some of the problems in speciation were covered by Behne (92/C800 9214097). He discussed the use of enzyme activities to measure metalloenzymes and immunoassay techniques for particular protein species. The reasons for the current interest in PIXE were discussed in a review by Johannsen (92/4089). Accelerators for PIXE could be relatively small. Old accelerators were being devoted full time to PIXE analysis and new systems were being built. The advantages of PIXE were high sensitivity versatility and multi-element capacity and in addition by combining with a microbeam technique element mapping could be carried out. A further review appeared on analysis of biological samples by PIXE written by Maenhaut (92/2156).The current status of element mapping using synchrotron X-ray microscopy was reviewed by Jones et a1. (92/2539) with reference to their own work at Brookhaven National Laboratory. The use of radionuclide XRF in clinical medicine was reviewed by Havranek et al. (9214003). Applications in haematology oncology and metal toxicology were described. Applications of accelerator mass spectrometry as a sensi- tive detector for radio-isotopically labelled molecules in the biomedical field were reviewed by Felton et al. (92/1139).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 81R Table 1 CLINICAL AND BIOLOGICAL MATERIALS Technique; atomization; analyte form* Sample treatmentlcomments AA;ETA:L Concentrations of Ag were measured in skin and other tissues of burned patients treated with silver sulfadiazine cream Accelerator MS was shown to be an extremely sensitive technique for the measurement of the rare isotope 26A1.The isotope was used for biological tracer studies. Samples were digested with HNO and ignited at 800 "C to produce A10- 27Al carrier was added and a pellet formed which was used for generation of the ion beam in a Ca sputter source concentrations of Cu and Zn was studied more sensitive than histochemical analysis for the detection of Al in exposed rats tracer to investigate Al kinetics in rats accelerator MS to identify carrier proteins in blood and uptake by cells Accelerator MS to measure 26A1 was used to study Al metabolism. Rapid uptake of Al into cerebral tissue was found Aluminium excretion in the rat was investigated with a 26A1 tracer measured by accelerator MS Distribution of A1 in cerebral cortex and forebrain from control subjects and patients with chronic renal failure was determined with 0.I Yo vlv Triton X- 100 the resolution between Al and Si secondary ions for SIMS analysis 1 +9 with H 2 0 (in Chinese) chemical modifier with K2Cr20 effectively removed the interference A1 concentrations in serum and urine increased when subjects with chronic renal failure commenced treatment with Sucralfate Complexes between A1 and noradrenaline dopamine and adenosine 5'-triphosphate were separated by SEC with a 6% hexamine-1% NH4Cl eluent. Al in the collected fractions was determined by AES A high background signal is present at the 396.15 nm wavelength.Performance at 237.33 nm was investigated as an alternative and reported to be acceptable for use in monitoring patients with chronic renal failure. Specimens were diluted with 0.05% Triton X-100 (in Serbo-Croat) The bioavailability of Al from three formulations of Al(OH) was investigated (in Portugese) MS-;S The effect of exposure to Al dust on the Accumulation of A1 in rats was studied. LMMS was 26A1 measured by accelerator MS was used as a Measurements of 26A1:27A1 ratios were made by Samples and aqueous standards were diluted 1 + 1 Preparative procedures were investigated to improve In a very simple procedure samples were diluted P compounds interfere with the atomization of Al. A Element Matrix Ag Blood urine tissues Reference 92/29 1 5 A1 Biological samples 92x62 1 A1 A1 Serum tissues Bone AA;ETA;L LMMS;-;S 921C674 921C868 A1 A1 Biological samples Blood.cells 9211 140 9211 141 A1 Biological tissues MS;-;S 9211476 921 1494 921232 I A1 A1 Biological samples Brain A1 A1 Serum Brain tissue AA;ETA;L MS;-;S 9212665 9212816 9213 180 92lC3705 A1 A1 Serum Brain AA;ETA;L AA;ETA;L Serum urine AA;ETA;L 921C3762 A1 A1 Neurotransmitters AE;ICP;L 9213834 A1 Serum. urine AE;ICP;L 92lC4257 A1 A1 A1 Serum Blood urine Neurotransmitters AA;ETA;L 9214216 921448 1 931c35 AE;ICP;L AA;ETA;L Formation of complexes between Al and brain neurotransmitters was investigated. Separation of complexes was achieved by SEC and reversed- phase HPLC Very low levels of A1 were concentrated onto Chelex- 100 resin at pH 6.5.The metal was eluted into a small volume of 1 mol I-' HN03 (in French) Tissues were digested with HNO,. A fast temperature programme was developed with no pyrolysis step and no chemical modifier. A bone digest solution was applied to coat the L'vov platform A1 Haemodialysis solutions Al Bone tissues 931454 931535 AA;ETA;L AA;ETA;L82R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 ~~ ~~ Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* A1 Water AA;ETA;L As Urine MS;ICP;G As Urine AA;Hy;L As Urine As Urine As As As As As As As As As Urine Urine Biological samples Urine Urine Urine hair Biological tissues Urine Biological samples AA;Hy;L AA;Hy;L AA;Hy;L AA; ETA;L MS;ICP;L AA;H y;L AE;ICP;L AA;H y;L AA;ETA;L AA;Hy;L MS;ICP;L AA;H y ; L Reference 931578 921C347 92lC452 9212258 9212635 9212726 92/29 14 Sample treatmentlcomments The benzyldimethyltetradecylammonium ion was formed from 100 ml water and collected on a PTFE filter.This was eluted with C2H50H-DMF and the A1 measured Several As species were separated by ion-exchange chromatography coupled to on-line HG for sample introduction. Marked differences in sensitivity between the As species was noted As3+ AsS+ dimethylarsinic and monomethylarsonic acids were separated by HPLC within 4 min. Dietary intakes influenced the concentrations of dimethylarsinic acid Measurement of As was described. The design of a FI system for HGAAS was described with optimization of the various components and the reagent concentrations.The importance of digestion and calibration procedures was indicated ice-acetone for 20 min. The supernatant was separated evaporated and the residue resuspended in H20. The As species were taken into phenol diluted with C2H50H and back- extracted into HzO. Extracts were evaporated dissolved in CH30H and separated by HPLC with on-line detection by HGAAS persulfate were evaluated. Good recoveries were obtained with a range of As compounds but arsenobetaine and arsenocholine (from fish) could only be completely recovered when Pd-S208 was used systems metabolites in urine. Increased excretion of total As was found after consumption of seafoods. The dietary As species arsenobetaine was shown to be unstable under certain conditions and may be converted into hydride generating compounds during storagelcooking.The work was also described in a Conference Report (ref. 92lC8 19) As3+ As5+ dimethylarsinic and monomethylarsonic acids were separated by HPLC within 4 min. Dietary intakes influenced the concentrations of dimethylarsinic acid. See As ref. 92lC452 IJrine was treated with HCI and then with KI. The As11* formed was extracted into CHC13 and then into 0.005 mol I-* K2Cr20,. A Pd chemical modifier was added. Hair was dissolved in a small volume of HN03 Three preparation procedures i.e. HN03-HC10 HNO3-HC1O4-H2SO Mg(N03)2 dry ashing were adopted to evaluate three systems for HG. The MHS- 10 the VGA-76 and the FIAS-200 hydride generators were studied and the recommended method (based on recovery precision speed of analysis) was MB(NO~)~ dry ashing with the Ion chromatography was used to remove C1- and suppress the ArCI+ interference on the measurement of As.The procedure also separated As"' AsY dimethylarsinic asid and methylarsonic acid Three methods for sample decomposition were compared for a range of As compounds. High blank values were obtained with dry ashing and acid digestion decomposition of arsenobetaine was incomplete with acid digestion. Best results were obtained with a commercial asher which used a mixture of 02-O3 and NO 5 ml urine+ 50 ml C2H50H were cooled in dry Chemical modifiers Ni and Pd with and without 17 As species were separated with three HPLC HPLC with FI-AAS detection was used to separate As FI AS-200 931409 931C906 92x3597 92/4 106 92146 18 93/c43 931c 194JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 83R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix B Biological samples B B B Plasma Urine faeces Tissues Technique; atomization; analyte form* MS;-;- MS;ICP;L MS;I CP;L AE;ICP;L B Body fluids and tissues AA;ETA;L MS;-;S XRF;-;S AE;ICP;L Ba Bone XRF-;S Ba Urine AA;ETA;L Bi Blood urine tissues AA;Hy;L Bi Serum blood AA;ETA;L Bi Serum urine AA;ETA;L Br Serum MS;ICP;L Br Plasma C Bone Ca Bone Ca Blood urine Ca Blood urine faeces Ca Gallstones Ca Biological samples Ca Bone Ca Skin muscle Ca Vascular tissue MS;ICP;L MS;-;S MS;-;- MS;-;- MS;-;- XRF-;S AA;-;- PIXEi-;- Sample treatmentlcomments Samples were subject to neutron activation to generate 4He and 3He from B and Li respectively. These isotopes were then measured by MS without problems associated with contamination Total B and loB:l1B isotope ratios were determined.The sample was fused with Na2C03 and the B collected by ion exchange on Amberlite IRA-743. B was eluted with 1% HN03 and the solution taken to a direct injection nebulizer. B in human plasma was at 24 pg 1-I Broccoli grown in a medium enriched with *OB was fed to animals in a study of B metabolism Tissue specimens were digested with HCI04 and H202. Biodistribution of B was determined in samples from patients receiving neutron capture therapy Atomization was improved by the inclusion of a Ca-Mg chemical modifier. The effects of the modifier were investigated by surface analysis by SIMS and SEM with EDXRF Ba and Pb were measured in archeological samples.Ba concentrations were 15-97 pg g-I Measurement of Ba in urine from occupationally exposed subjects was described Samples were digested with HN03. The residues were dissolved in 6 mol I-' HCI diluted in H 2 0 and taken for HG Pt modifier was included. Recovery and precision were measured An initial protein precipitation step was included. A Pd chemical modifier was used. The detection limit was 0.9 nmol I-' and good recovery was obtained mol I-' HN03 containing In as an internal standard. A result of 47.2 pg g-I was obtained with an RM. Interference from S was negligible Samples were diluted 5- or 10-fold with 0.14 Plasma Br and lipids were measured Accelerator MS was used to measure I4C in collagen and osteocalcin in modem and prehistoric bone to check results of dating studies.Large discordances were found to the metal and then to the hydride for detection and measurement of W a with a gas-ionization detector in an accelerator mass spectrometer Isotopically enriched Ca tracers were administered orally and intravenously in a study of intestinal Ca absorption. T a W a and 40Ca were measured by TIMS TIMS was used to measure Ca stable isotopes in studies of human Ca metabolism EDXRF was used to give structural and compositional data Ionized Ca was adsorbed onto a microcolumn of cation-exchange resin washed and eluted with HN03 directly into an AA spectrometer There was a non-uniform distribution of Ca and Pb. The distributions of Ca and Sr were similar Experimental tissue injuries were examined at different times after the wounds were induced.It was shown that results obtained post mortern could be used to determine the time of an injury Ca in samples of normal and hypertensive rats was examined Ca was extracted as CaO from the samples reduced Reference 921 I247 92/25 I3 921C3449 9214458 93x7 921 1 884 9212259 9212438 9213 169 931848 9211257 9314 15 9211 126 9211 29 1 9211 503 921 I 507 9212 158 9213 165 92/42 7 8 9214340 921442 184R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Cd Biological materials AA;ETA;L Sample treatmentlcomments A. graphite probe was used to provide isothermal conditions for atomization.Mg(N03)2 and Pd(N03)2 were added if necessary and aqueous calibration solutions were employed Reference 921C79 1 Cd Small intestine AA;-;- . . -- Cd Tissues 9 Cd Tissues Cd Liver kidney Cd Kidney Cd Liver Cd Biological tissues Cd Bone Cd Lung kidney liver Cd Red cells Cd Biological samples Cd Urine -;-;L AA; ETA$ AA;F;L AA; ETA;S AA;F;L AA;ETA;L Tissues were digested with HN03. Distribution of Cd was studied together with metallothionein and the effect of the route of administration on binding of Cd was investigated measurement of Cd in biological and environmental specimens R.apid solubilization was achieved by heating with HN03 and addition of C2HSOH to prevent coalescence of lipids. Other methods for sample preparation yielded similar results calibration material.Results were comparable to those obtained after sample digestion with HN03-HC104 (in Japanese) R.eview of methods for sample preparation and Samples were analysed directly with a CRM as 92lC865 921 1483 9211655 9211 9 14 A. cylinder of tissue was removed from the kidney 92lC 1 960 with a Ti tube. Cortex was separated dried and digested with HN03 for determination of Cd. The levels were compared with those determined in kidney halves to establish a relationship between cortex- and total-kidney concentrations. This allowed the simpler sub-sampling procedure to be used for a project with analysis of 8000 sheep kidney specimens Three approaches to solid sample analysis were investigated; platform boat-Zeeman-effect background correction solid-sample platform-D2 background correction graphite probe-D background correction. Results were compared with those obtained by FAAS and ETAAS after acid digestion Samples were digested with HN03 and H202 and the residues were dissolved in 1 mol 1-I HN03.Cd was determined in a Pt-tube atomizer in the presence of air. The atomizer offered stability in air and a long usable life. Performance was equal to that of graphite atomizers MS;ICP;L C:d and Pb were measured in a range of Ca-rich matrices by four different laboratories. All samples were heated at 425 "C for 24 h and the residues dissolved in HN03 and filtered if necessary. Reasonable agreements between the laboratories were obtained AA;F,air-C2Hz;L AA; ETA;L 92/20 I 3 9212490 9212602 9212836 Tissues from rats with chronic exposure to cigarette smoke were digested with acid and the Cd contents measured In vitro uptake of Cd by red cells was measured in the presence of HC03- and other compounds which influence membrane activity 92/28 5 5 AA;ETA;L Specimens were prepared in 0.14 mol I-' HN03 or as 92IC35 70 digests in 0.25 mol 1-l HClO,.The acidic solutions were atomized from a tungsten-coil atomizer mounted within a flow-through cell aligned to the optical path. Unlike a graphite tube the tungsten-coil atomizer was not affected by acid digests L'vov platform atomization profiles for aqueous Cd and different urine specimens were examined. There was complete separation of background from analyte peak 92lC36 54 AA;ETA;LJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 85R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Cd Blood faeces Cd Blood urine tissues Cd Tissues Cd Blood Cd Urine Cd Tissues.urine Cd Biological samples Cd Urine c1 Liver co Blood serum c o Tissues c o Serum co Synovial fluid blood co Tissues AA;ETA;L AA;F;L AA;FL XRF;-;S AA;ETA;L AA;ETA;L AE;ICP;L AA;ETA;L AA; ETA;L AA;ETA;L AA;ETA; L AE;ICP;L Technique; atomization; Element Matrix analyte form* Sample treatmentlcomments Cd Urine blood AA;ETA;L Cd and Pb were atomized from a L'vov platform coated with (NH4)2M004.4H20. Blood was diluted with NH4H,P04-Triton X- 1 00-HN03 urine with NH4H2P04-HN03. Standard additions calibration was not necessary for the urine assay and matrix matched calibration was suitable for both blood and urine Blood (0.3 ml) was mixed with 0.5 ml of 0.8 mol I-' HN03 to effect deproteinization prior to ETAAS.Dried faecal samples were ashed at 470 "C and dissolved in 1 mol I-' HNO for FAAS coprecipitation of Cd with an ammonium hexahydroazepine- 1 -dithiocarboxylate-Fe complex followed by dissolution of the precipitate in IBMK and introduction to the nebulizer determination of Cd (3-t 1) and the residue diluted to 5 mi with 1% HN03. Cd in this solution was atomized from a L'vov platform previously soaked with (NH4)2S04 (in Chinese) Graphite probe atomization was used to separate the analyte and background signals in specimens with high salt concentrations extracted into IBMK containing 1,5-bis(di-2- pyridylmethy1ene)dithiocarbonohydrazide. Details of the use of this new complexing agent which allows a 30 1 aqueous:organic ratio were described costs surface for homogeneous sample distribution fast heating rate long-term stability were described A tantalum-foil lining was placed into the graphite tube.The chemical modifier used contained HN03-(NH4)*HP04 (in Chinese) Powdered sample was loaded into a graphite cup positioned in an Ar atmosphere. An r.f. discharge produced an Ar plasma and caused the cup to heat with vaporization of the sample into the plasma The on-line method involved FI which provided A Si(Li) detector improved the sensitivity for i n vivo 1 ml blood was heated with 1 ml HN03-HC104 Cd in urine specimens and digested tissues was AA;ETA;L The features of a tungsten-coil atomizer i.e. low AA;ETA;L AE;r.f. plasma$ Co was measured in different blood fractions Samples were solubilized overnight in HNO3-HC1O4 and then heated to effect digestion.The residue was heated with HCI to reduce Sew to Sew and the pH adjusted to 4-5. Co and Se were measured in the same sample after chelation with APDC and extraction into IBMK Effects of potential diluents were investigated. HCl and HCIO suppressed absorbance and inorganic salts also affected peak appearance. Best results were obtained with 0.1 mol I-' HN03 or 10 pg Pd in 0.01 mol 1-' HN03 digested with acid or simply diluted with Triton X- 100. Concentrations were 2-3-fold increased in samples from a patient who experienced a tissue reaction against an artificial knee joint Samples were digested with HN03-HC104 and Co Mn and Ni were collected onto activated charcoal in the presence of 8-hydroxyquinoline and cupferron.The metals were desorbed and taken for measurement by ICP-AES. A 300-fold enrichment was accomplished Similar results were obtained when samples were Reference 9213865 9214058 921C4155 9214279 9214666 93x74 931C78 931C 16 1 9315 13 921457 1 92lC874 9212 155 921266 1 9212858 92lC338486R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; analyte form* Sample treatmentlcomments Reference 92lC4 I 5 5 Element Matrix c o Blood urine tissues AA;FL The on-line method involved F1 which provided coprecipitation of Co with a ammonium hexahydroazepine- 1 -dithiocarbox ylate-Fe complex followed by dissolution of the precipitate in IBMK and introduction to the nebulizer A system with tungsten-halogen background correction was used A high result was obtained with a 10-fold diluted NIST SRM Serum lJrine samples were treated with Fe3+ taken to pH 9 and heated at 100 "C for 30 min.Samples were filtered the precipitate dissolved in 2 mol I-' HNO and digested with H,O,; Cr3+ was measured in this solution. Total Cr was determined in urine specimens after digestion with HNO and reduction of Cld+ to Cr3+ with Na2S0 (in Chinese) IMeasurement of Cr in samples from occupationally exposed subjects was described Urine was diluted 1 + 1 with 2% vlv HNO,-O.OOl% vlv Triton X- 100. Zeeman-effect background correction was applied and steps to exclude contamination were described 4 3 is used as a dietary marker in metabolic studies.The effect of the mineral composition of the diet and digestion procedures on analytical performance was studied. Loss of Cr during digestion was reported AA;ETA;L MS;ICP;L AA;-;L !See Co ref. 9212858 Diurnal variations in concentration were studied I ml of blood was heated with 1 ml HNO3-HCIO4 (3+ 1) and the residue diluted to 5 ml with 1% HNO,. Cr in this solution was atomized from a L'vov platform previously soaked with NH,N03 (in Chinese) '4cidified samples were measured with Mg(NO,) as chemical modifier ,4 mini-autoclave was used for the simple safe digestion of human lenses with HN03-H2S04 'Homogenized liver was adjusted to 1 mol 1-I HCl shaken for 30 min and centrifuged. The supernatant was diluted as required with H20 and aspirated to take readings with background correction. Aqueous standards were used for calibration See Al ref.921C674 Powdered material was dissolved and sample solution placed into a graphite cup introduced into a modified plasma torch (in Japanese) Powdered specimens (2 g) were immersed overnight in 20 mi HCI0,-HCl (1:5) heated to evaporate almost to dryness and diluted to 25 ml with H 2 0 (in Chinese) Cu turnover was studied in Cu-replete and -deficient mice by measurements of 65Cu:63Cu ratios .4n acceptable result was obtained with a 10-fold diluted NIST SRM Serum 15 mg hair were dissolved at 90 "C in 5% tetramethylammonium hydroxide and diluted with 0.2% Triton X-100 (in Chinese) (Cu metabolism was studied in subjects who received a Zn-deficient diet by measurement of V u by TIMS "Cu concentrations were determined by TIMS in a long term study where animals were fed stable isotope enriched diets atomizer.Calibration with a CRM was preferred to the use of aqueous standards Biopsy samples were placed into a cup-in-tube 921C689 921 1484 921 19 12 Cr Cr Cr Biological materials Serum Urine Blood plasma red cells Urine AA;ETA;L AA;ETA;L 9212260 9212639 Cr Cr 9212724 Cr Faeces AA;ETA;L AA;ETA;L AA;ETA;L 9212858 92lC4 588a 9214666 Cr Cr Cr Synovial fluid blood Plasma urine Blood Cr Cr c u Urine Lenses Liver AA;ETA;L AA;ETA;L AA;FL 931C 143 931674 921C5 15 AA;ETA;L AE;ICP;L 921C674 921 1 166 c u c u Serum tissues Biological samples c u Kidney stones AA;FL 921 1380 Plasma liver Serum Hair MS;ICP;L MS;ICP;L AA;ETA;L 921 1403 921 1484 9212255 CU c u c u Biological fluids MSi-i- 9212694 c u 9212850 c u Liver muscle MS;-;- c u Liver AA; E TA;S 9212857JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 87R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Sample treatmentlcomments Reference c u Biological samples AA;F air-C2H2;L Buffered 1 -phenyl-3-pyridyl-2-thiourea was added to 921C364 I c u Liver AA;FL In c u Serum c u Tobacco c u Cerebrospinal fluid c u Liver c u Kidney c u Hair Fe Red blood cells Fe Blood Fe Cerebrospinal fluid Fe Serum urine Fe Bone marrow Fe Blood Fe Biological samples AA;-;- AA;F air-C,H,;L AE;DCP;L AA;ETA;L MS;ICP;L M S;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L MS;ICP;L AA;F air-C2H2;L samples and the Cu complex adsorbed onto microcrystalline naphthalene.The complex was dried and dissolved in DMF a rapid procedure a 5-fold homogenate was prepared in H 2 0 adjusted to 1 mol I-' HCI shaken and centrifuged. The supernatant was aspirated into the flame with background correction employed. Calibration was with aqueous standards and accurate results were achieved with an RM 9213843 9214095 9214420 921457 1 9214586 Sulfate was measured indirectly by formation of a [Cu(neo~uproin),]~(S0,2-) complex and extraction into IBMK. The LOD 3.2 nglrnl-' was superior to that of other techniques and the procedure was free from interferences. Sulfate concentrations in specimens from patients with jaundice and diabetes were higher than in normal subjects. The work was also described in a Conference Report (ref.921C456) A precipitate formed between Cuz+ and nicotine at pH 7.0-9.6 was collected by centrifugation washed with 25% CzHsOH and dissolved in 6 mol I-' HN03. The solution was diluted with H 2 0 and the Cu measured by FAAS for indirect determination of nicotine Levels of Cu in specimens from patients with Parkinson's disease were measured. Matrix interferences were reported to be less than with ETAAS 921C4 16 1 See CI ref. 9214571 Results obtained by a photoacoustic spectrometric procedure were compared with those given by AAS container intravenous routes respectively for 3 d. Two weeks later the 57Fe:56Fe and 58Fe:56Fe ratios were measured to determine the intestinal absorption of Fe Conditions for the measurement of 57Fe and V e with excellent precision were obtained.Samples with Fe at 10 ppm and above were diluted with buffer Mg(N03) was added as modifier and calibration standards were prepared in 10 mmol I-' I+N03- 1 15 mmol I-' NaCI. Concentrations were below 100 pg I-' in healthy children and were increased in those with viral meningitis Serum diluted with HC1-Triton X- 100 was applied to a tube previously impregnated with xylene. In an alternative procedure samples were deproteinized by addition of TCA-ascorbic acid. Fe in urine was extracted with APDC into IBMK or CHCl correlations with histochemical assessments were obtained intestinal absorption of Fe were measured using ETV of the specimens Preconcentration was effected by passage of dilute solution through a column containing 1,2- dihydroxybenzene-3,5-disulfonic acid and benzyldimethyltetradecylammonium chloride. The Fe was eluted with DMF and measured by FAAS Digestion with HN03-H202 in closed PTFE 57Fe and 58Fe were given to subjects by oral and Non-haem and ferritin Fe were measured.Good 57Fe and s8Fe administered to subjects to measure 931841 92lC340 92/C405 9212664 92/4060 92/43 3 7 9214603 92146 I688R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Fe Body fluids Fe Bone tissues Fe Liver Ge Tissues Hg Urine blood Hg Medicines Hair Hg Tissues Hg Hair Hg Biological tissues Hg Hair Hi3 Blood Hg Liver Hg Brain Hi3 Urine blood Biological tissues Hair urine Technique; atomization; analyte form* MS;ICP;L AA;ETA;L AE;ICP;L AA;ETA;L MS;ICP;L AA;F air-C2H2;L AA;FL AA; CV; L AA;CV;L AA;CV;L AA;ETA;L AA;CV;L AA;ETA;L AA;CV;L AA;CV;L AF;GC;G AF;CV;L Sample treatmentlcomments Spectral interferences encountered with biological samples were removed by use of principal components analysis.Chemical separation andlor manipulation of instrumental conditions were unnecessary See Al ref. 931535 Non-haem Fe was measured with Y added as internal After acid digestion the residues were taken into 7 standard mol I-' HCl the Ge was extracted into CCl and back extracted into H 2 0 (in Japanese) pathogens) were diluted to 10 ml with (NH,)2H2EDTA-NH4H2P04-NaOH-Triton X- 1 00 solution. Tetramethylammonium hydroxide 1 00 pl of 25% vlv solution was included for blood specimens.A T1 internal standard 40 pl of 1 pg ml-' was added and matrix-matched standards were used for calibration. Washout times between samples were less than 2 min Korean medicines were heated with HN03-H2S04 (1 + I ) and then with HN03-HClO (3+ 1). The Hg contents of three medicines were 1.5 3.2 and 55.5% With a 'seamed quartz tube' held above the burner the analytical sensitivity was 30 times better than with a conventional aspiration system. The detection limit was 0.01 pg ml-I concentrated by lyophilization. A commercial Hg analyser was used which includes ashing of the samples in O2 and formation of Hg amalgam. Distribution patterns obtained with this approach were in agreement with those of isotope studies Total and inorganic Hg were measured in hair from pregnant Faroese women.Higher concentrations associated with consumption of whale meat were found compared with other populations volatilization and distillation were used to separate organomercury compounds Total Hg and methylmercury concentrations increased in accordance with the amount of fish in the diet HN03-H2S04. Digestion was complete and there was no loss of Hg (in French) Hg and Se species were separated by ultrafiltration-chromatography. Measurement was by AAS with Pd chemical modifier Concentrations of Hg were measured in areas of the brain in developing rats who were exposed to methylmercury before birth Urine specimens were heated at 80 "C for 15 min with HN03-KMn04-H202. Samples of blood were diluted with an anti-foam agent and H20. These solutions were transferred to an FI manifold for addition of NaBH and generation of the Hg vapour A sensitive and accurate method for measurement of methylmercury was developed.The methylmercury was extracted with H2S04 and converted into the volatile methylmercury iodide by iodoacetic acid. The methylmercury iodide was headspace-injected for GC with an AF detector Specimens were digested with HN03 in a sealed PTFE vessel and diluted with H20. An FI system mixed the solution with SnCl to produce atomic Hg Sample 300 pl and 300 pl 2% mlv Virkon (to kill Protein fractions were separated by SEC and Techniques such as ion exchange extraction Blood was heated at 60 "C for 15 min with Reference 9214709 931535 931672 93174 1 921C366 921C503 921C5 16 921C86 1 921C873 9212908 9212980 921308 1 921309 1 9213161 921C3530 921C3603 9213950JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 89R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Hg Biological tissues Technique; atomization; analyte form* AA;CV;L Hs Blood AE;MIP;G Hg Blood plasma urine Hg Urine Hg Blood Hg Urine Hg Blood Hg Tissues Hg Blood urine Hg Biological tissue Hg Tissues Hg Biological samples Hg Blood urine In Urine K Serum K Cardiac muscle Li Biological samples AA;CV;L AA;CV;L AA;ETA;L AA;CV;L AE;MI P;G AA;CV;L AA;CV;L AA;CV;L AA;CV;L AA;CV;L A E; I C P; L AA; ET A; L AE;F;L XRF-;S MSi-i- Sample treatment/comments Different specimen types were lyophilized and digested in an ice bath for 1 week with H2S04-HN03-HC104-KMn0,-H202 complexed with DDC extracted into toluene and a butylating Grignard reagent added to form dialkylmercury derivatives.These were separated by capillary GC with MIP-AE detection. The work was also described in a Conference Report (ref. 92lC872) digestion with an increased sample volume. Good recovery was obtained and the detection limit was 5 nmol I-' NaOH solution and 10% ascorbic acid were added (in Russian) The pH was adjusted and the Hg complexed with DDC. The complex was extracted into toluene for measurement with Pd chemical modifier. The work was also described in a Conference Report (ref. 921C754) An FI manifold mixed the sample with SnC12 for the generation of Hg vapour. Improved sensitivity was provided by a gold trap and desorption by radiative heating diethyldithiocarbamate complexes into toluene.The extracted Hg species were butylated to allow separation by GC with an MIP-AE detector Tissue homogenate was mixed with H2S0,-NaBr and the methylmercury extracted into CHC13. The organic layer was mixed with HN03 in DMF prior to addition of NaBH to generate Hg vapour. The aqueous phase was taken for the measurement of inorganic Hg. Total Hg was determined in the homogenate after acid digestion Acid digestion procedures in closed vessels were investigated Use of the FIAS-200 FI system was described. The recommended procedure was modified by addition of hydroxylamine sulfate to the SnCI2 which gave improved sensitivity and precision In an extensive investigation of a continuous flow system it was shown that Hg was not released from methylmercury by the usual reductants but that effective digestion would achieve the breakdown.Atomization was suppressed by the presence of cysteine Methylmercury was separated by volatilization with GC and ion-exchange separation and CVAAS. Stability studies indicated that losses occur under certain conditions from some sample types Samples were diluted in an NH3 buffer and reduced by addition of NaBH which generated Hg vapour for transfer into the torch by the flow of Ar Measurement of In in urine from occupationally exposed subjects was described Results determined by ion chromatography with an ion-sensitive field effect transistor detector were in close agreement with those given by FAES A cryofixation procedure was used to preserve tissue composition.Sections were then lyophilized and embedded for analysis. Reduced Mg was found in tissue from animals subjected to heat stress Hg was released from protein by addition of HCI HN03 and HCIO ( 1 + 5) were used for overnight Samples were acidified with H2S04 and then 40% The sample was diluted with HCI to release the Hg. Urine was oxidized with solid KMnO and H2S04. Hg species were extracted as the See B ref. 9211247 Reference 9214 103 9214105 9214389 92/44 I0 9214652 93/C64 93lClOl 931C 105 93lC118 93/C 198 93167 1 931704 93181 1 921226 1 9211771 9212849 921 124790R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; analyte form* MS;ICP;L Sample treatment/comments A simple diluent with Be added as internal standard was used.Normal levels were 0.22-0.97 pg 1-' The method was accurate and precise and the detection limit was 0.02 mmol I-' Faeces were digested with acid in a study to measure 25Mg and 26Mg tracers See Ca ref. 92/4340 Cells were harvested on a discontinuous Percoll gradient. The cells were dried and dissolved in HCIOd-H2S04 See Cu ref. 92/C5 15 A new platform design was described which allowed for minimal conductivity heating. Multiple injections were introduced to improve sensitivity See Cu ref. 921 1380 Specimens were diluted 1 + 1 with a solution of Triton X-100 and NaEDTA standard additions or matrix-matched calibration was necessary and Zeeman-effect background correction was employed. Concentrations were not related to age or sex and the mean concentration was 10.8 nmol I-' Mn concentrations were measured in samples from patients with neoplasia See Co ref.92/C3384 Investigations of methodological variation were A range of chemical modifiers (Mg(NO,) BaF described HNO Pd-Mg(N03) Pd-hydroxylamine) were examined for use with serum specimens diluted with 0.2% Triton X-100. The Mg(NO,) and BaF were the preferred modifiers The sample was dissolved with acid and Mo extracted as the 5,5'-methylenedisalicylohydroxamic acid into IBMK. A detection limit of 0.03 pg m1-I was determined See Co ref. 92/2858 This review presents advantages and limitations of techniques suitable for measurement of Mo Results determined by ion chromatography with an ion-sensitive field effect transistor detector were in close agreement with those given by FAES 15-fold preconcentration was obtained by formation of a Ni complex at pH 3 with 1,5-bis(di-2- pyridylmethy1ene)thiocarbonohydrazide and extraction into IBMK exposed subjects was described Measurement of Ni in blood from occupationally See Co ref.92/C3384 The on-line method involved FI which provided coprecipitation of Ni with an ammonium hexahydroazepine- 1 -dithiocarboxylate-Fe complex followed by dissolution of the precipitate in IBMK and introduction to the nebulizer Biological samples were heated with HNO and H202 the residues dissolved in pH 9 buffer and the Ni extracted as the dimethylglyoxime complex into IBMK. Normal concentrations and levels in workers with occupational exposure were determined (in Czech) See Fe ref.9214709 Samples were diluted 20-fold with 1 mol 1-I HNO heated at 120 "C for 1 h and the Pb measured Pb macromolecules in serum and erythrocytes were separated by SEC. These components were measured in specimens from cases of childhood lead poisoning Reference 92/1287 92/1872 9212895 92/4340 93/4 1 3 92/C5 15 92/C748 92/ 1 380 92/ 1839 Matrix Serum Element Li Li Mg Mg Mi3 Mn Mn Mn Mn AE;F;L Urine Serum urine faeces MS;ICP;L Skin muscle Mononuclear leucocytes Liver Urine AA;F;L AA;ETA;L &dney stones Serum AA;F;L AA;ETA;L Mn Cerebrospinal fluid AA;ETA;L 92/ 1885 A E; I CP; L AA;ETA;L 92/3384 92/4640 Mn Tissues Mn Blood AA;ETA;L 92/20 1 5 Mo Serum 9212487 Mo Pharmaceuticals Mo Mo Synovial fluid blood Biological materials AA;ETA;L AA;ETA;L AE;FL AE;ICP;L 92/285 8 92/3238 92/1771 Na Serum Liver.urine AE;ICP;L 92/20 14 Ni Ni Ni Ni Blood Tissues Blood urine tissues AA;ETA;L 92/2262 92/C3 384 92/C4 1 5 5 AE;ICP;L AA;F;L Ni Urine blood tissues AA;-$ 92/4463 Ni Biological fluids Pb Serum MS;ICP;L AA;ETA;L 92/4709 92/C702 MS; 1CP;L 92lC863 Pb Blood componentsJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 91R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; analyte form* MS;ICP;L Element Matrix Pb Serum red cells Sample treatmentlcomments haemolysates from human and rat blood were separated by SEC. The LOD was 0.15 pg 1 - I An acceptable result was obtained with 10-fold diluted NIST SRM Serum Bi was used as an internal standard in a study of Pb mobilization by cisplatin Rapid solubilization was achieved by heating with HN03 and addition of C2H50H to prevent coalescence of lipids.Other methods for sample preparation were compared and gave similar results except for dry ashing which gave low values Ba and Pb were measured in archeological samples. Pb concentrations were less than 168 pg g-' Normal Pb concentrations in sweat and saliva were 1.5- 13 and 2.5- 10 pg 1-I respectively. See also Pb ref. 9212069 Tetramethyllead trimethyllead dimethyllead and inorganic Pb were separated by extraction with IBMK. These metabolites were measured in urine after experimental exposure to tetramethyllead (in Japanese) Pb protein components in serum and red cell See Cd ref. 92/2013 Reference 9211225 Pb Serum Pb LJrine Pb Tissues MS;ICP;L 921 1484 921 1 502 92/1655 MS;GD;L -;-;L Pb Bone XRF;-;S Pb Sweat saliva blood urine AA;ETA;L 921 1884 9211 908 Pb Urine AA;F;L 921 1909 Pb Liver Pb Sweat blood urine AA;ETA;S AA;F:L AA;ETA;L 92/20 1 3 9212069 Increased concentrations were measured in specimens from subjects with occupational exposure to Pb.See also Pb ref. 921 1908 applied to a graphite probe. Results were obtained without use of chemical modifiers and with aqueous calibration standards in Triton X- 100 matrices. Results determined by FAAS for CaC03 (but not for bone) were three times greater than values given by other techniques reflector the organic material destroyed in a low- temperature asher and the residue subjected to TXRF filter-paper and placed into a Delves' cup system. The cup was moved towards the flame to ignite the filter-paper and after the smoke had dissipated it was positioned directly into the flame Isotope ratio measurements were used to determine sources of exposure to Pb in children Samples diluted 10-fold with 0.1% Triton X-100 were analysed with NH4H2P04-Mg(N03)2 chemical modifier.Standard additions or matrix-matched calibration was employed Blood diluted 2+ 1 with HN03 was heated in a PTFE micro-pressure vessel. The digest solution was aspirated into a flame with a slotted quartz tube. The detection limit was 0.33 pmol 1-* (in Spanish) Pd-citric acid-HN03 was investigated. Higher ash and atomization temperatures were possible and O2 ashing eliminated the accumulation of residues Blood diluted 10-fold with 0.05% Triton X-100 was Cd and Pb were measured in a range of Ca-rich A 2 pl drop of blood was dried on a quartz glass a in discs were punched from blood spotted onto The effectiveness of a chemical modifier with 92x35 77 See Cd ref.9213865 9213865 See Cd ref. 9214058 9214058 Pb Blood AA;ETA;L 9212529 Pb Bone MS;ICP;L AA;F air-C2H2;L AA;ETA;L 92/2602 Pb Blood XRF-;S 921218 1 Pb Blood AA;ETA;S 9212834 Pb Blood Pb Blood MS;ICP;L AA;ETA;L 9212982 92/31 16 Pb Blood AA;F;L 9213 15 1 Pb Blood serum urine AA;ETA;L Pb Urine blood Pb Blood faeces AA;ETA;L AA;ETA;L AA;F;L AA;-;L Pb Blood Homogeneity stability and general properties of quality assessment specimens prepared by different agencies were compared. The work was also described in a Conference Report (ref. There was a significant correlation between age and 9214096 921~568) Pb concentrations in teeth specimens collected from subjects aged 14-60 years Pb Teeth AA;ETA;L 921427492R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 ~ ~~~ Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Pb Bone Pb Blood Pb Blood urine Pb Blood Pb Blood Pb Urine Pb Biological tissues Pb Biological samples Pb Blood Pb Hair Pt Urine Pt Urine Pt Biological fluids and tissues Pt Cerebrospinal fluid Pt Plasma urine Pt Plasma urine tissues Pt Body fluids and tissues Pt Serum cerebrospinal fluid Pt Plasma ultrafiltrate Pu Urine Ru Kidney Sb Urine Technique; atomization; analyte form* XRF;-;S AA;ETA;L AA;FL AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA; L AA;ETA;L MS;GC;L MS;GD;L AA; ETA;L AA; ETA;L AA;ETA;L AA;ETA;L MS;ICP;L MS;ICP;L AA;ETA;L MS;ICP;L AA;ETA;L AA; ETA;L Sample treatmentlcomments See Ca ref.9214278 Ellood was treated with HN03 centrifuged and the supernatant taken for the measurement (in Chinese) morpho1ino)ethanesulfonic acid buffer and the Pb extracted with APDC into IBMK for FAAS. Samples assayed by ETAAS were mixed ( 1 ml) with 0.1 ml of 1% Ni(N03)2 and 0.5 mol 1-1 HN03. Pb in blood was measured by ETAAS after precipitation of protein with HN03 (in Japanese) lJrine was adjusted to pH 5 with 2-(N- See Mn ref. 9214640 1 ml blood was heated with 1 ml HN03-HC104 (3+ 1) and the residue diluted to 5 ml with 1% HN03. Pb in this solution was atomized from a L'vov platform previously soaked with (NHJ3P04 (in Chinese) See Cd ref.93lC74 An automated on-line FI system was described which digested the sample (a slurry of powder in Triton X- 100) and introduced a measured aliquot into the graphite furnace See Cd ref. 93lC 16 1 Dried blood spots were punched from filter-paper and the Pb extracted into 1.25% (NH4)2HP04-0.5% Triton X-100 solution which was taken for analysis with Zeeman-effect background correction. Within-batch precision at 0.36 pmol 1-l was 19%. The method was used for determination of Pb in blood from newborn infants See Cu ref. 931841 Pt chelate with lithium bis(trifluoroethy1)dithiocarb- amate was sampled via capillary column GC. ID analysis was performed with addition of 192Pto the samples Wi was used as an internal standard in a study of Pb mobilization by cisplatin Plasma ultrafiltrate was diluted with 0.25% Triton X- 100 tissues were digested with HNO (in Chinese) F't concentrations were measured in samples from patients with neoplasia Samples were diluted 1 + 1 + 3 with Pt standard solution and 0.25% Triton X-100-IYo HN03 (in Chinese) A solution of HN03-HC104-H2S04 (24 + 24 + 1) was used to dilute urine and digest other specimen types.Pt concentrations derived by administration of a new antineoplastic agent were determined by ETAAS after extraction with APDC and IBMK A plan to use the high sensitivity of ICP-MS to study the long-term metabolism of Pt was presented Samples were diluted and acidified with HN03. A detection limit of 0.4 pg 1-1 was achieved Good sensitivity and precision were reported Samples were introduced into the ICP by ETV in a study to determine concentrations of Pu in occupationally exposed subjects Samples were solubilized in 25% tetramethylammonium hydroxide (in Japanese) IJrine at pH < 1 was heated with HCl to reduce SbV to Sb"'.Cupferron was added to form an Sb complex with extraction into IBMK. The detection limit was 0.6 pg 1-' and normal concentrations were less than 1.3 pg 1-1 Reference 9214278 921443 1 9214499 9214640 9214666 93lC74 93lC135 93lC161 931406 93/84 I 9211356 921 1 502 921 1 792 9211885 9212254 9214384 9214707 9214733 93lC 192 93lC30 931710 93lC47JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VQL. 8 93R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Se Hair Se Serum Se Biological materials Se Blood Se Plasma Se Tissues Se Blood Se Biological fluids Se Tissues Se Body fluids Se Blood Se Hair Se Liver Se Urine serum Technique; atomization; analyte form* AE;hollow cathode; L s MS;ICP;L AA;Hy;L AA;ETA;L AA;ETA;L AA;Hy;L AF;laser;L AA;Hy;L AA;ETA;L AA;ETA;L AA; H y ;L AA;ETA;L AA;ETA;L AF;Hy;L Se Blood urine hair AA;Hy;L Se Blood breast milk urine MS;GC;L faeces Se Biological samples Se Hair Se Eye tissue Se Serum AF;Hy;L AE;hollow cathode - AA;ETA;L AA;ETA;L Sample treatmentlcomments Hair was washed and then digested with HN03 or cooled with liquid N2 and ground to a powder. Solutions were dried on and powders were distributed onto the wall of an A1 cathode cup Samples were introduced by ETV the detection limit was 2 ng ml-' FI was used for sample introduction An Ir-Mg chemical modifier was pre-injected onto the L'vov platform.Zeeman-effect background correction and 0 ashing were included in the procedure (in French) Plasma concentrations in children aged 8-1 2 months were higher in those fed cow's milk than those given milk formula (39 and 31 pg ]-I respectively) A digestion procedure modified by inclusion of HCI gave improved recovery. Selenomethionine spiked into samples behaved more like endogenous Se than did inorganic Se Use of LEAFS for trace element measurements was discussed. Pd(N03) was added to the blood Advantages of FI-HGAAS were presented See Co ref. 92/21 55 Influence of chemical modifiers on the signals given by inorganic and organic Se compounds was investigated in simple solutions as a preliminary step to a study of the analysis of body fluids.Optimium results were obtained when the modifier produced a refractory oxide and no thermostable carbide; would convert the analyte into a single form and would trap the analyte within the modifier residue. Use of a mixture of Pd(N03) and Mg(N03) with considerably more of the latter than is usual e.g. 10 pg+2 mg was proposed See As ref. 9212635 See .4s ref. 9212980 See Hg ref. 9213091 Effectiveness of digestion accomplished with HBr and Br was monitored by differential pulse polarography. All the organoselenium compounds tested were converted into Sew with quantitative recovery Specimens were digested with HN03 and HC104 the residue dissolved in HCI and taken for HG (in Chinese) Samples were digested with HNO3-HC1O4-HzO2 and excess HN03 removed with HC02H.HCI was added to reduce Sew the Sew was chelated with 4- trifluoromethyi-o-phenylenediamine and extracted into CHC13. A stable isotope tracer was added at the start of the procedure and the Se ions were separated and detected by GC-MS. The method was used to study absorption and retention of Se in lactating women Sew for HG with an FI system. Detection limits of 10- 100 pg were obtained digested with HN03 or powdered at liquid N2 temperature. Ionization interference was observed owing to high concentrations of Ca in the samples Concentrations of 0.23-0.41 pg g-I were measured in cornea iris lens and retina Sample was diluted 1 +4 with a solution containing 0.1% Rh(N03)2-0.250/o Triton X-100 (in Japanese) HBr-Br converted seienomethionine and Sew into Hair washed with diethyl ether-acetone was either Reference 921C649 921 146 1 921 1652 921 1 722 921 1 768 921 1769 9212085 9212 106 9212 155 9212622 9212635 9212980 921309 1 92x36 3 5 9213938 9214098 921C4250 92x4255 9214448 921454394R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Se Blood urine Se Blood hair Se Serum plasma Se Biological fluids Se Se Se Se Se Si Si Si Si Serum Serum Tissues Serum Serum Serum breast milk Brain tissue Blood Body fluids and tissues Sn Tisues Sn Tissues Sr Cerebrospinal fluid Sr Bone Te Urine Te Plasma Te Urine Technique; atomization; analyte foim* AA;ETA;L AF;Hy;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETAL AA,ETA;L AA;ETA;L AA ETA; L AE;ICP;L MS;-;S AA;ETA;L AA,ETA;L MS;-;S XRF-;S AE;ICP;L AA;ETA;L A.A;ETA;L AA;ETA;L XRF;-;S AA ; H y ; L Reference 921465 1 Sample treatmentlcomments Interferences were studied as a function of the efficiency of atomization of P.The effects of Ni and Pd on the atomization profiles were investigated. Interferences were minimized when P atomization was enhanced or significantly delayed Sample was heated with HN03-HC104 (4+ 1) and the residue diluted with HzO. The solution was heated with HCl and K13H4 for HG (in Chinese) Samples were diluted 3-fold with H20 and the Se atomized from a L'vov platform with Pd chemical modifier. Calibration standards were prepared in a solution which contained albumin P043- Ca NaCl Pd and Triton X-100 With a Ni chemical modifier the trimethylselenonium species atomized in the same way as selenite.When a Pd modifier was used the response with trimethylselenonium was reduced by 50% Concentrations of Se were determined in specimens from patients with liver cancer (in Japanese) Title and abstract are identical to Se ref. 931738 but the paper is in English Tissue specimens from rats fed different doses of Se were digested with HN03-HClO (in Japanese) Concentrations of Se were determined in specimens from patients with liver disease and gastrointestinal cancer (in Japanese) patients with myocardial infarction 8.8-10.8 and 5.4-7.3 pmol l-' respectively (in Japanese) Low concentrations were found in samples from Normal serum and breast milk concentrations were See Al ref. 9212876 Sensitivity was improved with a tungsten-coated graphite tube and 50 pg ml-I Ca chemical modifier chemical modifier.The effects of the modifier were investigated by surface analysis by SIMS and SEM with EDXRF. The work was further described in a second paper at the same Conference remove interferences. The method was said to be rapid accurate and sensitive organs were determined (in Japanese) patients with neoplasia Atomization was improved by the inclusion of a Ca Ascorbic acid was added to wet-ashed samples to Sn concentrations in a large number of different Sr concentrations were measured in samples from See Ca ref. 9214278 Urine specimens were digested with HNO3-HC1O4 and evaporated to dryness. The residue was dissolved in HCl and heated to dryness to reduce TeV1 to TeN.Samples were dissolved in 6 mol 1-l HCl for HG. Recovery was reported to be 90-95% and normal concentrations were 0.02-1.63 pg 1-I investigated Plasma samples were digested with acid and Te extracted into IBMK. Total Te was determined by ETAAS or the solvent was deposited onto high-purity graphite backings to measure isotope ratios by SIMS 50 ml of urine were heated with HN03-HClO and evaporated to dryness. The residue was dissolved in 1 ml HCl evaporated and redissolved in 7 mol 1-l HCl. This solution was analysed by HGAAS or mixed with IBMK and the organic layer taken for ETAAS. A lower detection limit was given by HGAAS and the normal levels of Te in urine wcre 0.02-1.63 pg 11' AA;ETA;L MS;-;L Use of stable isotopes for kinetic studies was AA;Hy;L 92lC3 560 AA;ETA;L 9214675 93lC70 93lC75 93/738 931743 931745 931746 93lC870 9211 879 9212876 92lC4 157 93lC7 93lC72 9212833 931749 9211 885 9214278 9212479 9212653JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 95R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Te Urine AA;Hy;L Sample treatmentlcomments Reference 931740 After digestion with HN03-HC104 the Te was reduced by HCI to TeIV and the solution analysed by HG (in Japanese) Liver from a Thorotrast patient was ashed heated to a cake with HNO3-HCIO4 and NH4HS04 and dissolved in aqua regia See Th ref. 9214480. Normal tissue concentrations were determined. Results were lower than those previously reported Samples diluted 1 + I + 1 with 0.1 5% Triton X- 100 and Ti standard in 0.06 mol I-' HN03 were atomized from a pyrolitic graphite coated graphite tube.The detection limit was 2.1 1 ng m1-I. Increased concentrations were found in specimens from patients with loose hip replacements Urine samples were digested with HN03 and H202. The residues were dissolved in 30% HC1 before extraction into diisobutylketone. A Pd-ascorbate-Triton X- 100 chemical modifier was added Solid samples were heated in a graphite furnace for LEAFS with a N,-laser pumped dye laser Samples were diluted 10-fold. Chemical modifier was added to provide 6 pg Pd and 100 pg (NH4)2N03. Aqueous standards were suitable for analysis of blood but standard additions calibration was required for urine 9214480 921448 1 92lC3 744 See Th ref.9214481 With an LOD of 35 ng l-l the procedure was suitable for monitoring occupational exposure but not for the determination of normal levels A complex between V02+ and monothio-B-diketo liquid chelating exchanger was formed and extracted into CHCI A detection limit of 0.1 pg I-' was achieved by chelation of V with cupferron and extraction into IBMK 921448 1 92/47 I 1 92lC8 7 5 9212434 See Pb ref. 921C3577 V in urine digested with HN03 and HC104 was 92lC3 5 77 9214359 extracted as the APDC complex into CH3CC13 (in Chinese) Bone dissolved in HN03 was diluted with H20 and then with a solution which contained Pd-citric acid and Triton X-100. Specimens from patients with chronic renal failure had high concentrations of v Concentrations of Zn in blood urine and tissues were reduced by feeding rats a Zn-deficient diet See Cu ref.921C5 15 See Al ref. 921C674 See Cu ref. 9211 380 Preparation procedures were compared 1 + 99 931C3 18 dilution with 0.1 % Triton X- 100; digestion with HNO,; and dilution with Triton X-100. The first method was the most efficient (in French) 1.03 ppm respectively Normal values for colostrom and transitional milk were 45-3 18 and 30-1 46 pmol 1-I A sample of bloodstained filter-paper was placed into a tube with 3 ml 10% HCI allowed to stand for 24 h with occasional gentle shaking and the extract taken for FAAS. A dry ashing procedure was also described Zn concentrations in tears and serum were 1.537 and Samples were diluted 1 +99 with 0.1% Triton X-100. Plasma was diluted I + 4 with 20% mlv TCA Th Liver MS; 1CP;L Th Tissues MS;ICP;L Ti Serum AA;ETA;L T1 Urine AA;ETA;L 9212436 T1 Liver T1 Blood urine AF;ETA;S AA;ETA;L 9212555 9314 14 U U Tissues Plasma urine MS;ICP;L MS;ICP;L V Urine AA;ETA;L V Urine AA:ETA;L V V Blood serum urine Urine AA;ETA;L AA;ETA;L V Bone AA;ETA;L Zn Biological tissues and fluids 92lC495 AE;ICP;- 92/C5 15 921C674 921 1 380 92/1871 Zn Zn Zn Zn Liver Serum tissues Kidney stones Breast milk AA;FL AA;ETA;L AA;FL AA;ETA;L 921 1888 9212620 Zn Zn Tears serum Breast milk AA;-;L AA;ETA;L Zn Bloodspots AA; F; L 9212648 Zn Plasma AA;F;L 921266596R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Zn Breast milk Technique; atomization; analyte form* AE;ICP;L Zn Plasma urine faeces MS;ICP;L Zn Zn Zn Zn Zn Zn Zn Zn Tissue proteins Hair Skin muscle Hair Liver Pancreatic tissue Biological samples Serum Various Serum Various Serum Various (7) Biological fluids Various (4) Blood Various (6) Biological samples Various (7) Serum Various (1 0) Drugs Various (4) Blood liver Various (6) Blood red cells serum MS;ICP;L AA;-;L MS;ICP;L MS;ICP;L MS; 1CP;L AA; ETA; L MS;ICP;L MS;ICP;L AAi-i- AA;FL Sample treatmentlcomments Effectiveness of decomposition methods was assessed by measurement of residual C.Improved results were obtained by increase in pressure or by addition of H2S04 and HzOZ The ratios of 70Zn:68Zn in samples from pre-term infants were established. Specimens were decomposed and extracted into CCI with APDC. The CCI4 was evaporated under a small volume of 0.1 mol 1-' HN03 Zn compounds associated with tissue proteins were separated by SEC or by HPLC and the stable isotopes measured by ICP-MS Washed hair was dried heated to 190 "C and ground to a powder to prepare a sample disc 5 mg of beard sample was prepared in a tube MS;ICP;L XRF;-;S AA;-;- See Ca ref.9214340 AA;F;L designed to minimize contamination. Pulse aspiration of 80 pl into the flame was effected (in Japanese) AE;r.f. p1asma;S AA;ETA;L See C1 ref. 9214571 Pancreatic islets were separated from tissue partially digested with collagenase. The material was sonicated and heated at 90 "C with 1 mol 1-* HN03. Results were compared with visual histochemical assessments provided by a Zn- binding fluorescent dye Zn isotopes were determined after separation from the sample matrix by extraction of the DDC complex into CC14 and back extraction into HNO (lidocaine dicaine procaine) and Zn(CSN),+ and extracted into 1,2-dichlorethane.The Zn was measured as an indirect method to determine the concentration of anaesthetic in serum (in Chinese) The effect of nebulizer gas flow rate on signal size was measured Detection limits interferences accuracy and precision were investigated with RMs Use of stable isotopes for tracer studies was discussed. The requirement for precision of 0.1 % or less was noted and this was achieved for most elements studied but not for Li (Ag Cu Fe Li Ion pairs were formed between anaesthetics Mg Pb zn) Higher gas temperatures were reported with Pd as a chemical modifier. Matrix-matched and aqueous calibration curves were similar except for Mn (Cu Mn Ni Pb) nebulization is subject to many interferences.Sample introduction by ETV was reported to remove most of them (Co Cr Fe Ni V Zn) Spectral interferences caused by C1- and other anions were eliminated by use of Dowex-1 resin. The procedure was used to analyse the second generation serum RM (As Co Cr Cu Mn Ni Zn) Concentrations of As Ca Cu Fe Hg Mg K Mn Na and Zn were measured in 100 drugs to determine metal contamination Metals were co-precipitated with iron([[)-hexamethylenedithiocarbamate and the precipitate redissolved and transported to the flame in a stream of IBMK. Sensitivity was increased 50-70-fold (Cd Co Fe Zn) Methods for measurement of metals in specimens from chronic renal failure patients and control Analysis of biological samples using pneumatic On-line preconcentration by FI was developed.AA;ETA;L Reference 92x335 7 92x3410 9214 104 92lC4 170 9214340 9214435 921457 I 9 2lC4 5 8 8c 93lC368 9315 12 92lC382 92lC404 92lC439 92lC45 1 92lC472 92lC473 92lC493 92/C500 92x5 I3 subjects were presented (Al Cu Fe Pb V Zn)JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 97R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Various Biological samples AA;FL AE;ICP;L Various (30) Hair serum Various ( 10) Biological samples Various Biological samples Various (7) Serum Various (7) Liver Various Blood Various (9) Serum Various Blood serum Various Serum Various (5) Tissues Various (9) Soft tissues bone Various ( 10) Biological samples AE;ICP;L AE;ICP;L AA;ETA;L S AA; ETA;L AA;ETA; L AE;ICP;L AA;ETA;L MS;ICP;L AA;ETA;L MS;ICP;S AA;-;- AE;ICP;L AE;ICP;L Sample treatmentkomments A new PTFE digestion bomb which gave a moderate vapour pressure with HN03-H202 and microwave heating was used.Digestion was complete within 3-6 min and results for RMs were close to the expected concentrations Hair dissolved in acid and serum specimens were diluted with 4.8 mol I-' HCl. Matrix-matched standards were prepared An oxine-cellulose microcolumn was used for on-line preconcentration. Enrichment factors of 8.2- 1 3.5 were achieved with 5 ml load volumes. Factors which influenced performance were investigated Chemical dissolution or direct solid sampling procedures were employed.Similar results and performance characteristics were obtained Experiments showed that for some analytes there were differences in effectiveness of chemical modifiers when added to aqueous compared with protein-containing solutions. These workers recommend dilution with 0.1 mol 1-I HNO and the addition of Mg(N03)2 for A1 and Cr of H3P04 for Cd and Pb and of H3P0,+Ca for Co and Mn Digestion procedures were compared and heating with HN03-HCI04 was selected. A number of chemical modifiers and other analytical parameters were investigated (Cu Fe Mn Pb Se Ti Zn) Concentrations of metals in blood specimens of welders were determined Work to characterize a 'second-generation' RM was extended to include more elements most at concentrations of less that 2 pg 1-1 (B Ba Bi Cd Cs Li Mo Pb Sn) Metals were co-precipitated with iron(i1)-hexamethylenedithiocarbamate and the precipitate redissolved and transported to the furnace in a stream of IBMK.A 20-fold enhancement in sensitivity was obtained by electrophoretic procedures were measured by laser ablation ICP-MS. Pre-prepared electrophoretograms of known composition were used for calibration Tissue concentrations were measured after dry ashing. Levels were determined after exposure to toxic agents and to toxic materials together with a Japanese medicine claimed to protect the liver (Ca Cu Fe Mg Zn) Bone was digested with HN03-HC104 other tissues with HN03-HC104-H2S04. Solutions were aspirated with a Hildebrand grid nebulizer which was used with high uptake and shorter wash-out times; extensive wash to prevent clogging; and matrix-matched standard solutions (Ca Cu Fe K Mg Mn Na P Zn) A slurry of powdered RM in H 2 0 and acid (HCI or HNO or HN0,-HCI or HN03-H202) was pumped into a coiled PTFE tube and placed into a microwave oven to be heated for 2 min.Results were compared with the certified values and with those obtained after conventional acid digestion open vessel microwave digestion and 32 min microwave digestion in the coiled tube system. Analyses were precise but accuracy was variable (Al Ba Ca Cd Cu Fe Mg Mn Pb Zn) On-line preconcentration by FI was developed. Elementslisotopes in biological compounds separated Reference 92lC580 92lC654 92lC65 5 92lC685 92lC687 92lC690 92lC70 1 92lC707 92lC7 36 92lC827 92lC866 921937 92194798R JOURNAL OF A.NALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.$ Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Various Biological samples MS;-;S Various (1 7) Bone Various (9) Urine AE;ICP;L MS;ICP;L Various (24) Biological samples MS;ICP;SI Various (5) Faeces urine plasma MS;-;- Various (25) Serum whole blood Various ( 18) Liver Various Biological samples Various Biological tissues Various Tissues Various (4) Serum Various (4) Serum Various (5) Bone Various (24) Breast milk Various Urinary stones Various (8) Medicinal plants Various ( 13) Serum whole blood Various (4) Tissues Various Hair Various (5) Biological samples MS;ICP;L MS;ICP;L MS;ICP;L MS;-;S -;-;S AA;-;L AA;F;L XRF;-;S AA;-;L AE;ICP;L PIXEi-;- XRF-;S AA;-;L AE;ICP;L AA;-;L AE;F;L AE;ICP;L XRFi-i- AE;ICP;L 9211434 9211501 9211 5 1 8 9211554 921 1702 Sample treatmentlcomments Reference 921 I 139 921 1362 Applications of accelerator MS; binding of carcinogens to DNA sensitive tracer studies studies of the targeting of drugs etc.were described Samples were ashed at 500 "C and digested with An FI manifold was prepared for on-line standard 9211 153 9211 243 HNO3-HF-HCIO4 additions immediately prior to nebulization. The rate of sample analysis was thereby increased Powdered samples were ground and suspended in 1% Triton X-100 Stable isotopes were administered to subjects to determine intestinal absorption and endogenous excretion rates. Isotope ratios were measured in samples by automated TIMS (Ca Cu Fe Mg Zn) 0.5 ml serum + 0.5 ml HN03 or 0.5 ml blood + 1.0 ml HN03 were heated at approximately 95 "C for 3 h in a 30 ml screw-cap vial.These solutions were diluted to 5 ml with H 2 0 containing Rh internal standard. Saliva was diluted 1 +4 with 1% vlv HN03. Rapid (5 min) measurements of large numbers of elements were achieved with the 'semi-quantitative' analysis mode. The advantages and limitations of this approach were given Results obtained by NAA and ICP-MS were in relatively good agreement Materials digested with HN03 were determined (in German) A review of the use of SIMS Ion microprobe analysis was applied to thick biological specimens. The ratios of the peaks to background intensities provided a simple approximation to the certified concentrations and it was predicted that good accuracy would be possible with the aid of organic standards Increased concentrations of Cu with lower levels of Se and Zn were found in patients with certain diseases of the liver (Cu Mn Se Zn) A variable volume injector was used to introduce samples into an FI system (Ca K Mg Na) Using SR-XRF Fe Ga Sr and Zn were localized in bone of subjects treated with a Ga compound Samples of breast milk from mothers in six countries were analysed.Differences were shown between actual and recommended daily intakes for many elements Correlations between certain pairs of elements were seen Plants were dried ground and pressed into pellets (Br Cu Fe Ni Pb Rb Sr Zn) (in Czech) Evacuated blood collection tubes designed for trace element specimens were tested.Except for trace amounts of Pb no elution of metals was found under normal conditions of use Digestion methods and analytical techniques were examined. The preferred procedure was to digest with HN03 and measure the elements by ICP- AES but very low recoveries were obtained for some element-tissue combinations (Dy Eu Y Yb) (in Japanese) 9211276 921 140 1 Approximately 200 specimens were analysed Digestion with HN03-HC104-H2S04 gave better results for As than did HN03 in a closed pressure vessel. Interferences from Cu and Ni were eliminated by use of a mixed NaBH,-KI reductant. A continuous flow system for HG without a gas-liquid separator was devised for introduction of sample into the ICP (As Bi Sb Se Sn) 921 1 772 9211773 921 1 823 9211 824 9211 825 921 1 830 9211 838 921 1 842 921 1859 9212003JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 99R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; analyte form* Element Matrix Various Biological samples Sample treatmentlcomments Reference 9212029 M S; Resonance ionization;S Applications of sputter initiated- and laser atomization-RIMS were reviewed. These included determination of trace element concentrations spatial distribution of U in bone localization of stable isotopes in DNA Trace element concentrations were determined in specimens from normal and cancerous tissue The perturbation of distribution of metals by the administration of Rb was investigated. (Ca Fe K Rb Zn) Various Colonic mucosal biopsies Various (5) Blood liver kidney 9212038 9212042 A review of sample preparation and analytical procedures An instrument for micro-probe SR-XRF was built with sensitivity to detect fg amounts of analyte Various well-established procedures for acid digestion were compared (in Chinese) ICP-AES was evaluated and found to be a rapid economical procedure for measurement of urinary electrolytes (Ca K Mg Na) introduction and separation-enrichment techniques A general protocol for simultaneous determination of most of the elements of biological interest was presented Examples were given of microvolume sample A review of SR-XRF microscopy Prostatic and mammary cells were examined.Even with short time intervals between sampling and freezing some movement of elements appeared to occur between cell compartments It was proposed that dried ground materials can contain ‘nuggets’ with high analyte contents.These would produce inaccurate results if included in the sample taken for the analysis CRMs can be used for calibration in solid sampling AAS. This review gives a list of appropriate CRMs and their composition to assist in the choice of a suitable RM Human tissue samples and powdered RMs with an In internal standard were heated with HN03 in sealed containers. Results obtained by ICP-MS were within the certified limits. Drift was reasonably well controlled by the internal standard. Good agreements were obtained between AAS and ICP-MS Principles and potential applications of LMMS in dental science were reviewed together with a study of metallic particles found in mucosal tissue Samples were analysed by ID-SSMS (in Chinese) Washing procedures were compared (in Chinese) 0.1-10 rng were placed on a graphite platform and rapidly heated by three IR lamps an air stream transported the smoke to the flame.Results for CRMs were in good agreement with the certified values (Cd Cu Pb Zn) Concentrations were measured in maternal and foetal cord blood. There was no influence associated with maternal parity or foetal sex. Normal values were reported (As Cd Hg Pb) measured. Au In and Pd had poor solubility but other metals were released into the media with associated cytotoxicity (Ag Au Cd Cu Ga In Ni Pd Zn) Interferences in FAB-SIMS analysis associated with metal hydrides were eliminated by careful and consistent technical work and expertise with MS Release of metals from dental casting alloys was 9212 156 9212392 9212426 9212464 Various Biological samples Various Biological samples Various Biological tissues Various (4) Urine PIXE;-;- XRF;-;S AE;ICP;L AE;ICP;L AA;FL 9212498 Various Biological samples AE;ICP;L MS;ICP;L Various (33) Biological tissues MS;ICP;L 921252 1 Various Biological tissues Various Freeze-dried biopsy tissue 9212 5 3 9 9212540 XRF;-;S XRF-;S Various Pulverized tissue 9212549 AA;ETA;S 9212550 Various CRMs AA;ETA;S Various ( 12) Tissue samples M S;ICP; L AA;FL AA;ETA;L 9212608 9212696 Various Oral mucosal tissue LMMS;-;S Various (25) Ginseng samples Various Hair Various (4) Biological tissues MS;SS;- AE;ICP;L AA;F;S 92127 15 9212120 9212838 Various (4) Blood Various (9) Tissue culture medium AA;ETA;L AA;FL 9212844 92/289 1 9212896 Various (1 0) Biological samples MS;-;-1 OOR JOURNAL OF A.NALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Various Various Various Various Various Various (8) Various (7) Various Various (7) Serum Biological samples Biological fluids Biological samples Riological samples Biological fluids Tissues Tissue specimens Serum Various Biological samples Various (4) Biological tissues Various (5) Biological samples Various (14) Tissues breast milk serum Various (4) Urine Various Biological samples Various (5) Biological samples Various (5) Plasma blood Various (8) Otoliths Various (4) Urine Various Biological samples Various Serum plasma urine Various (6) Pharmaceutical products Technique; atomization; analyte form* MS;ICP; L AA;ETA;L AE;ICP;L AA;ETA;L AE;ICP;L AA;ETA;S AA;ETA;L XRF;-;- LMMS;-;S AA;ETA;L XRF;-;S AE;ICP;L AE;ICP;L MS;ICP;L .. -- I AA;ETA;L AA;ETA;L AE;ICP;L AA;ETA;L . . -- I MS;ICP;L AE;ICP;L Sample treatmentlcomments A procedure to dry the diluted specimen reduced the interference associated with H 2 0 loading of the plasma. An ashing step eliminated polyatomic ion interferences A number of materials were tested for their potential use in on-line preconcentrationlseparation methods A review of methods and the use of L'vov platform A review of recent developments SIMAAC determinations of solid samples placed into a graphite cup were described Analytical sensitivities were increased by use of Pd Pt or Rh chemical modifiers (Al As Bi Cu Li Ni Pb Se) Tissue distribution of metals was measured following exposure to automobile exhaust.The animals were normal controls and those given supplements of Cu Fe and Zn (Br Cu Fe K Pb Rb Zn) Measurement of the distribution of elements within cellular or subcellular structures was possible Diluents and chemical modifiers were used as appropriate. Deproteinization and multi-loading (20 p1 x 5) were adopted for measurement of Co Cr Mo and Ni with acceptable precision except for Co Procedures for sample preparation were considered and a number of analytical techniques were compared with AAS SR-XRF was used to study the spatial relationships between elements in tissues (Cu Hg Se Zn) (in Japanese) Sensitivity was increased by the use of an ultrasonic nebulizer (As Cr Mo Se Sn) Reference values for trace elements were determined in specimens collected from normal individuals Actinides were separated by column chromatography from other elements in high concentration (Am NP pu U) Factors that are critical to sample collection analysis and the interpretation of results were set forth The effectiveness of alkaline Ni and Pt as chemical modifiers was investigated.A nickel-aminino compound was used for Ge with basic lithium chloroplatinic acid for other elements (As Ge Sb Se Te) Measurement of metal to monitor the effectiveness of chelation therapy was described (Al Cu Fe Pb Zn) Bone sample was dissolved in HNO and the solution taken for measurement of metals by AES.Calibration solutions were prepared to contain similar concentrations of CaCO (Ca K Mg Mn Na P S Sr) Urine was diluted 1 + 1 with H20 and a Pd chemical modifier was employed with standard additions for calibration (Cd Cr Ni Pb) prepared CRMs from NIES electrophoresis with a direct interface to the ICP mass spectrometer column. Alkaline earth alkali metals and anions were not retained while the transition metals were concentrated on the column which was coupled to the ICP spectrometer (Ba Ca K Na Mg Sr) This report described existing and some newly Species separation was accomplished by capillary Test solutions were passed through a chelation Reference 92/29 12 9212984 9213087 9213088 9213089 9213090 9213 I60 9213237 9213243 9213253 9213273 92lC33 12 92lC3403 92lC3420 92lC3505 92lC352 I 92lC3 5 5 7 92lC3572 92lC3 5 80 92lC3608 92lC3690 92lC3 77 3JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 l Q l R Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Technique; atomization; Element Matrix analyte form* Various (4) Biological samples AA;FL Various Biological samples Various (4) Hair AA;ETA;Sl AA;FL AA;ETA;L Various Blood tissues XRF-;- Various Biological samples PIXEi-;- . . -- Various Biological samples > Various Biological samples Various ( 16) Tissues Various (8) Hair Various (5) Biological fluids Various (5) Blood Various Hair Various (1 5) Lung tissue Various (7) Breast milk Various (1 1) Cocaine heroin Various (1 8) Hair Various (4) Lenses Various (5) Biological samples Various ( 5 ) Tissues Various ( 5 ) Tissues Various (4) Bone Various (4) Serum Various (7) Urine XRF;-;S XRF-iS -a_- 1 AE;ICP;L AA;ETA;L AE;ICP;L AE;ICP;L AE;ICP;L AA;F,L AA;ETA:L AA;ETA;L AE;ICP;L AE;ICP;L AA;ETA;L AE;ICP;L AA;ETA;L Sample treatmentlcomments slurry samples with HN03 was developed.The digested material was pumped directly to the AA nebulizer (Ca Fe Mg Zn) An FI system for on-line microwave digestion of Details of analyses of slurry samples were reviewed Ashed hair was dissolved in 0.2% HNQ. Cu Fe and Zn were measured by FAAS Cr by ETAAS (in Chinese) This review of the application of XRF to clinical problems focused on sample preparation Typical applications of PIXE analysis were given. The work was also described in a Conference Report (ref. 921C704) Methods for separation of trace element compounds were discussed with emphasis on sampling storage and sample preparation.The work was also described in a Conference Report (ref. 921C450) Methodological developments for elemental speciation during 1986- 1990 were presented Powdered material was pressed into a pellet Measurements were taken along the length of hair samples collected from women during childbirth to detect changes during pregnancy (Al Br Ca C1 Cu Mg Br S) The organization of an Italian interlaboratory quality assessment scheme was described (Al Cd Cu Pb Zn) interlaboratory quality assessment scheme was discussed (Al Cd Cu Pb Zn) Performance of Italian laboratories in an Quality control for hair analysis was described Normal concentrations of metals in different zones of the lung were determined in residents of an urban industrial area in Italy HN03 in a study to determine reference values in Italian residents (Al Ba Cu Fe Mg Mn Zn) Element contents of the drugs were measured to try and identify their geographic origins.Preliminary data indicated that this 'fingerprinting' was a viable approach Specimens were analysed in a study to determine reference values in Italian residents Cataractous lenses contained increased concentrations of Ca Cu and Zn and lower levels of K compared with normal lenses Didodecyldimethylammonium hydroxide was used for solubilization of tissues and as the chemical modifier in ETAAS (Co Cu Mn Mo Ni) Alterations in the concentrations of trace elements were determined after exposure to Hg2+ or methylmercury (Ca Cu Hg Mn Zn) Essential elements were measured in ten tissues after digestion with HNO and HCIOl in sealed PTFE vessels ( Ca Cu Fe Mg Zn) (in Japanese) Outer and inner sections of ancient skeletal samples were analysed.High concentrations of Cd Pb and Zn were taken to indicate post mortcm contamination. Concentrations in samples of inner bone were similar to those reported for other ancient humans and were much lower than in modem man (Ag Cd Pb Zn) Samples were treated with HNOS-HCIO (Ca Mg Na P) (in Japanese) The study involved SIMAAC with standard additions for calibration (Cd Co Cr Cu Mn Ni Pb) (in Japanese) Milk specimens were lyophilized and digested with Reference 9213828 9213900 9213942 9214003 9214089 9214097 9214099 9 2 x 4 175 9 2 x 4 1 78 92lC4222 921C4223 921C4224 921C4245 921c4247 921C4248 92lC4249 92lC425 1 9214283 9214289 9214326 9214329 92/4407 9214446102R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Matrix Various (7) Urine Various (2 1 ) Saliva Various ( I 6) Serum Various (4) Serum Various (5) Serum cerebrospinal fluid Various (30) Clinical and biological Various (4) Hair samples Various Pharmaceuticals Various ( 14) Hair Various Biological RMs Various Blood urine Various (4) Urine Various (1 3) Bone Various Biological samples Various (6) Blood bone dialysis fluid Various ( 1 1) Cocaine heroin Various ( I 1) Penicillin G Various (4) Urine Various Biological fluids tissues Various Biological fluids tissues Various (7) Serum Technique; atomization; analyte form* AA;ETA;L XRF;-;- AE;ICP;L AA;F;L AA;F;L AA;ETA;L AA; Hy;L .. -- 3 AAi-i- AE;ICP;L AE;ICP;L . . I_._ 7 TXRF-;S AA;ETA; L AE;ICP;L MS;ICP;L MS;ICP;L AA;ETA;L AE;ICP;L AE;ICP;L AA;ETA;L AA;F;L AA;Hy;L AA;CV;L AA;ETA;L AA;ETA;L Sample treatmentlcomments ’The normal concentrations in 334 specimens were measured by SIMAAC (Ca Co Cr Cu Mn Ni Pb) (in Japanese) specimens of saliva showed a diurnal variation (in Russian) determined in 4 17 specimens from subjects aged 7-20 years (in Chinese) Concentrations were determined in maternal- and cord-blood samples (Ca Cu Mg Zn) (in Chinese) !Specimens were collected and analysed from patients with tumours of the brain (Cd Cu Mn Se Zn) (in Chinese) ‘The 1992 ASU review of the determination of elements in Clinical and Biological Materials ]Lower concentrations of Mg and Zn were found in samples from children with learning disabilities (Cu Mg Pb zn) 26 Chinese drugs were washed powdered and dried.These materials were heated with HN03 and HC104 evaporated to dryness and the residue dissolved in 8% HCI (in Chinese) Hair was soaked in a detergent washed with H 2 0 and dried. Samples were then immersed overnight in HN03-HC104 (3 + 5) heated to near dryness and diluted with H20 (in Chinese) An update of biological and environmental RMs with sample codes and addresses of suppliers ]Background scatter was reduced by in situ microwave ashing and inclusion of chemical modifiers ]Detection limits determined from measurements with solvent blanks were compared with those prepared from true sample matrix blanks.Sample blank detection limits were approximately 1.5 times greater than solvent blank detection limits Bone was dissolved in acid. Matrix interferences were investigated and matrix-matched calibration standards were used 1:nterferences associated with anions Na etc. were removed by on-line chromatography using a chelating resin with iminodiacetate functional groups at pH 5.3. Analytes were retained while interferents were eluted to waste ‘Trace elements were measured in specimens from patients with chronic renal failure (Al Cu Fe Pb v Zn) concentrations of trace elements. Cocaines were digested in acid while heroins were dry ashed (Al Ba Cd Cr Cu Fe Mg Mn Ni Pb Zn) A V-groove nebulizer was used to allow sampling of concentrated solutions. Matrix matched buffered solutions were used for calibration (Cd Co Cr Cu Fe Mn Mo Ni Pb Ti Zn) The urine was diluted I + 1 and injected with PdClz for simultaneous multi-element analysis (Cd Cr Ni Pb) ]Methods to measure elements of clinical interest by FAAS HGAAS and CVAAS were given in this chapter Methods to measure elements of clinical interest by ETAAS were given in this chapter Concentrations of trace elements were measured in samples from patients with lung cancer (Al Cr Mg Mn Pb Se Zn) (in Japanese) Concentrations of some elements in unstimulated IVormal concentrations of trace elements were The drugs were characterized on the basis of the Reference 9214447 92145 18 9214544 9214545 9214560 9214562 9214 5 8 8c 9214665 92/46 7 7 9214702 93lC25 93/c49 93lC5 1 93lC59 93lC 149 931479 931530 931563 93163 1 931632 931737JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 103R ~~~~~~~~ ~ Table 1 CLINICAL AND BIOLOGICAL MATERIALS-continued Element Various (10) Various ( I 1) Various (1 2) Various (1 3) Various Matrix Bile Technique; atomization; analyte form* AE;ICP;L Bile and biliary stones AE;ICP;L Pharmaceuticals AA;ETA;L MS;ICP;L Seminal fluid AA;-;- Teeth INDIRECT ANALYSES- Sulfate Serum Nicotine Tobacco Anaesthetics Serum AE;ICP;L AA;F;L Sample treatmentlcomments Reference 93f739 Concentrations of Ca Cu Fe K Mg Mn Na P Sr and Zn were determined in specimens from patients with different types of hepatobiliary disorders (in Japanese) See Various ref. 931739 (in Japanese) Concentrations of elements in 90 antihypertensive 931742 931747 931748 93x893 drugs were determined (in Japanese) Possible relationships between trace elements and infertility were investigated (in Japanese) A cation-exchange resin was used to reduce the content of Ca and P 9214095 AA;-;- Sulfate was measured indirectly by formation of a [Cu(neocuproin)2]z(S04z-) complex and extraction into IBMK.The LOD 3.2 ng mi-' was superior to that of other techniques and the procedure was free from interferences. Sulfate concentrations in specimens from patients with jaundice and diabetes were higher than in normal subjects. The work was also described in a Conference Report (ref. 92lC456) See Cu ref. 92lC4 16 1 AA;F air-C,H,;L 92lC4 16 1 AA;-;L See Zn ref.9315 12 9315 12 *Hy indicates hydride and S L G and SI signify solid liquid gaseous or slurry sample introduction respectively. Other abbreviations are listed elsewhere. The sensitivity and small sample requirement were particu- larly advantageous allowing measurement of not only inorganic species such as 41Ca in bone absorption and 26A1 in neurotoxicity but also organic molecules through label- ling with 14C. An overview of a series of studies on measurement of reference values for trace elements in biological materials by ICP-AES was given by Caroli et al. (92/C3403). Materials studied were human lung kidney liver hair breast milk and serum. Many of these studies were discussed in detail in last year's Update (92/4562). Barnes (92/3088) reviewed the use of ICP-AES and ICP-MS for trace element determi- nations in the biomedical field. The application of ETV or direct vaporization to analysis of biological materials by ICP-AES or MIP-AES was reviewed by Matusiewicz (92/42 84).Two chapters in a recent book provide an excellent intro- duction to the application of AAS to the determination of trace elements in clinical samples. The first by Taylor (93/631) covers FAAS and HGAAS and gives detailed methods for the determination of As Au Bi Ca Cd Cu Fe K Li Mg Na Pb Sb Se and Zn in serum and urine. The second by Delves and Shuttler (93/632) on ETAAS deals with interferences sample preparation and the use of modifiers. The determination of individual elements is reviewed covering practical problems and their solution. Applications involving the use of stabilized temperature platform furnace (STPF) conditions for determining metals in biological fluids were reviewed by Subramanian (92/3087). 1.2.Sampling and Sample Preparation Special evacuated blood collection tubes produced by the Sherwood Medical Company for trace element determina- tion were evaluated by Moyer et al. (92/1838). The tubes tested with three pools of human serum were shown to be acceptably free of contamination except for Al. Mn and Pb. The increase in serum A1 concentration was small and only occurred after 24 h when in contact with the rubber stopper; blood would not remain in the tube in normal practice for that length of time. Perhaps the most interesting recent development in sample dissolution is on-line microwave-heated digestion.Samples as slurries are digested with acid in an FI system. One of the problems is how to control the build-up of pressure. Haswell and Barclay (92/3838) overcame this by using a back-pressure regulator and by cooling the liquid flow after the heating stage. They analysed a number of biological RMs including NIST SRM Bovine Liver for Ca Fe Mg and Zn using on-line digestion with 5% v/v HN03. Total analysis time was 1-2 min per sample. Karanassios et al. (92/947) used a stopped-flow system in which the sample slurry was mixed with an acid mixture and pumped into a coil in a microwave oven. The flow was stopped the inlet and outlet sealed with valves and the coil heated for 2 min. The digest was then pumped out and analysed by ICP-AES. Results on CRMs were compared with certified values and with results obtained by conventional hot-plate digestion and open vessel digestion with microwave heating.Precise and in many instances quantitative digestions were pro- duced by this technique. Burguera and Burguera (93/C 135) developed a computer-controlled system for the determina- tion of Pb in biological materials by FI-ETAAS. Homo- geneity of the slurry was maintained by ultrasonic agitation and digestion occurred in a coil in a microwave oven followed by a degasification device to remove bubbles. Aliquots of the digest were automatically injected into an electrothermal atomizer with separate addition of modifier. The total analysis time was 3 min including the furnace programme time. The efficiency of wet digestion has been followed in two studies.In a study by Matusiewicz et al. (93/841) hair was chosen as the model material for digestion with HN03-H202 in closed PTFE bombs with either thermal or104R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 microwave heating. Residual C was determined by coulo- metry after combustion in an O2 stream. In all cases examined decomposition remained incomplete even though the experimental parameters were varied. In their study Krushevska et al. (921C3357) measured C by ICP- AES at the 193.1 nm line. Results were in good agreement with measurements of C by a spectrophotometric proce- dure. Skimmed formula and breast milk were subjected to dry ashing high-pressure digestion with conventional heat- ing and three commercial microwave-heated digestion procedures.In the wet digestion procedures they evaluated HNO alone HN03-H202 and HN03-H2S04. In all cases Zn recovery was close to 100% but residual C was less when increased pressure was used and when H202 or H2S04 was added. Whether this is important for atomic spectrometric techniques such as ICP-AES or AAS seems unlikely as demonstrated by the results obtained by Luterotti et a!. (9213843). They determined Cu Mn and Zn in rat liver by homogenizing the material with five times the weight of H20 adjusting the $IC1 concentration to 1 mol l-* shaking for 30 min and centrifuging the resulting mixture. Determi- nation was by FAAS on the supernatant using aqueous standards for calibration. Good results were obtained with this technique on NIST SRM Bovine Liver.Heltai et al. (921C580) described their own design of a PTFE bomb which allowed the vapour pressure to be maintained at a moderate level. Using this device several biological RMs were digested for 6 min with HN03-H202. Analysis of the digests for a range of elements by FAAS and ICP-AES showed agreement within 1-5% of the accepted values. Applications of slurry sampling to the analysis of biologi- cal materials by AAS or AES were reviewed by de Benzo et al. (9213900). Mochizuki et al. (921 1276) applied slurry sampling to analysis by ICP-MS. Using slurries in 1% v1v Triton X- 100 good results were obtained for 24 elements in NIST SRMs Bovine Liver and Rice Flour. However results on NIST SRM Pine Needles were lower than the certified values for many elements.Samples were wet-milled for 30 min in a micronizing mill but the workers believed that this did not break down the fibrous pine needles sufficiently. The use of RMs in solid sampling ETAAS for quality control and calibration was reviewed by Herber (92125 50). A proposal was made that biological RMs should be classified on the basis of their inorganic matrix content. Simultaneous multi-element determination of solid biologi- cal samples by ETAAS was described by Atsuya (9213089). A miniature cup atomizer was used. Solid sampling ETAAS was used by Luecker et al. (9212013) in quality control in the production of Bovine Liver RMs. Comparison of results with a method based on wet digestion followed by determi- nation by ETAAS showed that solid sampling ETAAS was an adequate method for quality control.Unless a sample is homogeneous solid sampling ETAAS can give erroneous results. The occurrence of rare particles of high analyte content leading to a skewed distribution of analytical results was modelled statistically by Kurfurst (9212549). Analysis of biological materials by ICP-MS frequently requires prior separation to remove anions such as chloride phosphate and sulfate which can give rise to isobaric interferences. Fisher et al. (931C59) used an on-line system with a column of a chelating resin to retain trace elements while the anions were eluted to waste. A change in pH allowed the trace elements to be eluted into the nebulizer of the ICP. An anion-exchange resin (Dowex-1) was used by Goossens et al.(921C473) in their separation procedure for ICP-MS which they tested with several RMs including the Versieck 'second generation' serum RM. Fundamental studies of separation of trace elements on a range of commercial resins for analysis of biological samples by ICP- AES and ETAAS were made by Pietra et al. (9212984) using radiotracers. There have been some interesting developments in on- line preconcentration of trace elements for determination by FAAS (921C500 921C4155) and ETAAS (921C736). Using an FI system trace elements were coprecipitated with iron hexahydroazepine- 1 -dithiocarboxylate collected in a reactor made of knotted PTFE tubing and eluted with IBMK. Sensitivity increases of 20-70-fold were achieved with removal of much of the matrix. The determination of Cd Co Ni and Pb in plant leaves bovine liver and whole blood was possible by FAAS after preconcentration with good precision (1.5-3% RSD) and accuracy as demon- strated by the analysis of CRMs.Schramel et ad. (921C655) described the performance of a commercial on-line precon- centration system using a quinolin-8-01-cellulose micro- column for determination of trace elements in biological samples by ICP-AES. Better detection limits were achieved and sensitivity increases of up to 13.5-fold were found. Accuracy tested on a number of CRMs was satisfactory except for Cr and Fe. For determination of Co Mn and Ni in tissue digests by ICP-AES Yaman and Yaman (921C3384) developed a preconcentration procedure by chelation with quinolin-8-01 and cupferron. The complexes were collected on activated C and then desorbed allowing enrichment factors up to 300-fold with an RSD of l-8%.Mahan et al. (921C755) showed how algal cells could be immobilized on silica gel particles and used in a column for preconcentration of Cd Cu Pb and Zn. Another possibility was to use a metallothionein isolated from yeast cells. This coupled to agarose gel formed a column which would selectively bind Cu as CuI. To elute the Cu an oxidizing agent was used to convert the Cul to Cu". 1.3. Novel Techniques Work on the application of metal atomizers in ETAAS continues. Ohta et al. (9212490) described a Pt tube atomizer and its application to the determination of Cd in NIST SRMs of biological origin. The atomizer which could be used in air with a lifetime of more than 1000 cycles had excellent sensitivity (LOD for Cd 0.09 pg).Results on the SRMs agreed with the certified values. Similarly applica- tion of the low-cost tungsten-coil atomizer to the determi- nation of Cd in digests of various biological RMs (921C3570) gave results within the certified ranges even though the digests were in HC104 normally an interfering anion in ETAAS. A mixture of 90% Ar- 10% H2 was used as purge gas. Studies on the mechanism of atom formation suggested that Cd atoms were formed by dissociation of CdO and Pb atoms by hydrogen reduction of PbO (931C161). The signals for Pb were modified by the presence of NaCl and the precision of measurement improved as the heating rate was varied to improve the temporal resolution of the Pb signal and background signal (931C162).An r.$ discharge lamp for determination of trace elements in solid samples by AES was developed by Kitigawa and Katoh (9214571). Samples as powder or solutions were inserted into a graphite cup electrode. When a discharge was passed the sample was vaporized atomized and excited. The system was applied to the determination of C1 Cu and Zn in NIST SRM Bovine Liver. A hydride generation system for ICP-AES developed by Schrarnel and Xu (9212003) dispensed with the conven- tional gas-liquid separator. The system was applied to the sequential determination of As Bi Sb Se and Sn in biological materials after digestion giving results on a range of CRMs in agreement with the certified values. A mixed reductant of NaBH and KI eliminated interference from Cu and Ni.An FI system for HGAAS was evaluated and optimized by Welz and Schubert-Jacobs (921263 5). BecauseJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 105R of the small volumes used the characteristic mass values for the FI system were 16- to 57-fold better than for a batch system although the characteristic concentration values were similar. Interferences were less severe with the FI system. Application to the determination of As in urine and Se in blood and urine was demonstrated. An FI method for carrying out on-line standard additions allowed fast determination of toxic elements in urine by ICP-MS. Weiderin et al. (92/1243) injected 500 pl of sample solution into the flowing stream and sequentially injected 50 pl of various standard solutions through a second injection valve in a second stream.The two flows were merged and nebulized into the ICP. Ming-Zhao et al. (92/C352 1) studied suitable modifiers for the determination of the metalloids As Ge Sb Se and Te by ETAAS. Lithium chloroplatinate was found to be a more effective modifier for As Sb Se and Te than most commonly used modifiers including Pd. The best modifier for Ge was an aminonickel complex. Prior separation of the elements was carried out either by HG and trapping in an aqueous solution of Br2 solvent extraction or solid-phase extraction with treated cotton. Ni et al. (92/3090) preferred modifiers based on Pd Pt or Rh and gave details of their methods developed for As Bi Cu Ni Pb and Se in urine A1 and Li in whole blood and serum and Ni in some biological RMs.A combination of neutron activation (NA) and the high precision of MS gave the technique of neutron activation mass spectrometry (NAMS) which workers at NIST (92/1274) applied to the determination of B and Li in various biological matrices. The technique had very high sensitivity and contamination after irradiation was irrele- vant as only the activated products were determined. Applications of RIMS to biomedical analysis were de- scribed by Arlinghaus et al. (92/2029). By using sputtering or LA techniques it was possible to localize with very good spatial resolution the measurement of concentrations down to sub-ppb levels for example in studies of natural U in bone and in sequencing stable isotope labelled DNA.1.4. Reference Materials Quality Control and Inter-labora- tory Trials Roelandts (92/4702) published a further update on a compilation of available CRMs. Developments at NIES described by Okamota and Morita (92/C3608) resulted in a freeze-dried Human Serum CRM which was certified by results from at least three different analytical techniques. As an outcome of their programme on metal speciation a freeze-dried Fish Tissue CRM was produced certified for organotin compounds and a Human Hair CRM which will be certified for organomercury is under preparation. The National Research Council of Canada has an active programme in this area and developments were outlined by McLaren (92/C822). Their successes include the certifica- tion of four biological tissues for organomercury and speciation of As in Dogfish Muscle CRM.New Bovine Kidney and Bovine Liver RMs were produced in Czecho- slovakia (93/C896). Measurements of Pb in these materials and the corresponding BCR materials by ETAAS showed that whereas it was possible to determine Pb in liver digests by simple aqueous calibration digests of kidney and bovine muscle showed more interference and required calibration by standard additions. Details of the Italian interlaboratory quality assurance scheme run by the Istituto Superiore di Sanita in Rome were given in two presentations (92/C4222 921C4223). Initially set up in 1983 for blood Cd and Pb determinations the scheme was extended to serum A1 in 1985 and serum Zn and Cu determinations in 1987. Common internal quality control materials were distributed to all participating laboratories.Improvements over the years were noted for performance in the determination of blood Cd and Pb and serum Al. Changes in the standard of determination of serum Cu and Zn were not apparent because many of the laboratories were already performing satisfactorily and because the period of monitoring was shorter. Six blood Pb quality control materials (AM1 B701-5) from the Danish National Institute of Occupational Health were evaluated in an interlaboratory comparison against existing CRMs and commercial quality control materials (92/C568 92/4096). The 12 laboratories using methods based on ETAAS and ASV were pre-selected from a previous interlaboratory evaluation. The calculated stan- dard deviation of results on the AM1 materials was similar to that for the BCR CRMs and results for the BCR CRMs agreed well with the certified values produced by the BCR in 1985.Internal quality control data from those labora- tories that used commercial quality control material or CRMs suggested no change in value over a period of 5-6 years. A statistical protocol for evaluating methods using AAS was proposed by Christensen et al. (92/4640). The protocol produced estimates of the uncertainty of the result sys- tematic errors and the limit of quantification based on the relative mean square error. It was applied to methods for the determination of Mn and Pb in blood. 1.5. Analysis of Body Fluids 1.5.1. Aluminium The use of 26Al as a tracer has aroused recent interest. Barker et al.(92/1141 92/C621) used accelerator MS as a sensitive method to measure the isotope 26A1 free from interference from the isotope 2aMg. Calibration was made by using pellets of a known 26Al:27Al ratio. Samples needed to be digested with HNQ and then dried and ignited at 800 "C to obtain the oxides. Quantitative addition of the carrier 27Al was made and the 26Al:27Al ratio measured from which the 26A1 concentration in the sample could be derived. Aluminium uptake in a human subject was measured in this way (Lancet 1991 137 1345). Blood samples were taken 6 12 and 18 h after ingestion of 26A1 in sodium citrate solution. The highest plasma 26A1 concentration was found in the 6 h sample mainly bound to transferrin (80%) and albumin (10%). About 1% of A1 was estimated to have been absorbed.Meirav et al. (92/ 1 140 92/ 1494) employed the same technique to study A1 kinetics in the rat. About 75% of the intravenous injection of 26A1 was excreted in the urine in the first 24 h and this only increased to 80% after three weeks. Serum A1 concentrations are frequently used as a guide to exposure and except in patients with renal failure the results can be misleading. This is shown in the study of Rollin et al. (92/C674) on rabbits exposed to A1 dust for 5 months. This study was set up as a result of previous work on foundry workers exposed to A1 dust who showed only a slight increase in serum A1 but significant changes in serum Cu and Zn. The rabbits also showed only a slight elevation in serum Al measured by ETAAS but concentrations in the main organs were significantly elevated especially in the brain where concentrations were nearly two and a half times those in controls.Copper and Zn concentrations increased in some organs. In view of these findings it may be incorrect to conclude from the study of Haines et al. (92/2665) that A1 is not involved in brain dysfunction. Their study failed to show any significant difference in serum A1 concentration in patients with and without cognitive impairment. Methods published for the determi- nation of A1 in serum show little that is new. For determination by ETAAS simple dilution with a dilute solution of Triton X-100 (92/2665 92/4276) or distilled106R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 water alone (9213 180) is adequate as has been shown many times before.Deloncle and Clanet (93/454) preconcentrated A1 in water used for haemodialysis by passing it through a Chelex 100 column at pH 6.5. The A1 was eluted with 1 mol 1-1 HN03 for measurement by AAS. Direct determination was carried out by Bermejo-Barrera et al. (93/480) by ETAAS using a modifier of Pd with Mg(N03)2. 1.5.2. Antimony Smith and White (931C47) determined Sb in urine by ETAAS after extraction with cupferron. The urine samples were first heated with HCl to reduce SbV to SblI1 before extraction with cupferron into IBMK. Aliquots of the solvent layer were injected onto a L'vov platform in the graphite furnace. The LOD was 0.6 pg near to the concentrations they found in non-exposed individuals (~0.6-1.3 pg 1-l). The method was used to measure urine Sb concentrations from workers exposed to Sb.1.5.3. Arsenic The determination of total As in urine by HGAAS is now well understood and has appeared as a recommended method of the German Science Foundation (92/2258). Determination by ETAAS is not so well understood but Nixon et al. (92/2914) produced a method with well- demonstrated accuracy. Platform atomization with Zee- man-effect background correction was used and compari- son was made between a Ni modifier and a mixed Pd-K2S208 modifier. Both gave complete recoveries of As from Asr1' AsV dimethylarsinic acid (DMA) monomethyl- arsonic acid (MMA) and o-arsinilic acid but only the Pd modifier gave complete recoveries of As from arsenobetaine and arsenocholine. Calibration was by matrix-matched standards. Should we measure total As in urine? Assessment of exposure to As is complicated by the fact that people who eat fish excrete arsenobetaine and arsenocholine in their urine.These organoarsenic compounds present in seafood are considered to be non-toxic and relatively stable. However the work of Miirer et al. (9214106) demonstrated that some degradation of arsenobetaine and arsenocholine could take place perhaps during storage or cooking of the seafood. Flow injection HGAAS was used without prior digestion a technique which does not detect arsenobetaine or arsenocholine. After eating fish or mussels four volun- teers showed an increase of up to 5-fold in measured As in urine. It was shown that solutions of arsenobetaine and arsenocholine in water showed some decomposition on exposure to daylight or treatment with H202 and could therefore be the source of increased As in urine found in this study.Most interest in recent years has been in the complete speciation of As in urine combining liquid chromatography with atomic spectrometric detection. Direct detection by ICP-MS can suffer from isobaric interference from C1- which forms ArCl+. Sheppard et al. (93/409) improved their former method for As speciation [see last year's review (92/4562) or original paper (9 1/583)] so that C1- ions eluted at a different time to the As species. By changing from the phthalic acid eluant used in their previous method to a carbonate buffer at pH 7.5 with the addition of a small amount of ethanol all As species were resolved including MMA and DMA which had co-eluted in the former procedure.A better separation was achieved by Roehl and Alforque (92/C3447) who using anion-exchange chromato- graphy coupled with ICP-MS achieved an LOD of 1-5 pg 1-l for all As species. When on-line HG was introduced before the detector the sensitivity improved by a factor of up to 50. However arsenobetaine was not then detected and the sensitivity depended strongly on the species. Similar conclusions were reached by Miirer et al. (921C8 19 92/4106) in their separation of the As species in urine by anion exchange. Direct coupling of the eluant to ICP-AES would give complete speciation but was not sufficiently sensitive for normal concentrations. On-line FI-HGAAS was about 35-fold more sensitive but could not detect arsenobetaine or arsenocholine.On-line HGAAS was used by Hakala and Pyy (921C452 9214618) to detect species separated by ion-pair chromatography on a cl8 reversed- phase column using tetrabutylammonium ion in phosphate buffer as the ion-pairing agent. Determination of the species As1IX AsV MMA and DMA was possible for the urine of persons occupationally exposed to As but the system was not sensitive enough for urine from subjects unexposed to As. Interestingly although AsIII AsV and MMA concentrations correlated well with exposure DMA concentrations did not and they might have resulted from seafood consumption. The species derived from seafood consumption arsenobetaine arsenocholine and tetra- methylarsonium cations were determined by Momplaisir et al.(92/2726) in urine by extraction and preconcentra- tion followed by separation on a cyanopropyl bonded- phase HPLC column with a mobile phase of MeOH-Et20- HOAc and detection by HGAAS. Although complete speciation is important for a real understanding of the processes of As metabolism it could be argued that for assessment of occupational exposure what is needed is a measurement o,f total As excluding arsenobetaine and arsenocholine. Halls (93/C43) adapted a previously published method (Anal. Chim. Acta 1975 79 93) in which As"' AsV MMA and DMA reacted with KI in 6 mol 1-l HCl to form halide complexes which could be extracted into CHC13. After back-extraction into 0.005 mol 1-1 K2Cr207 the As was determined by ETAAS using Pd as a modifier. 1.5.4.Barium Schaller (92/2259) described an approved method for the determination of Ba in urine by ETAAS for the assessment of occupational exposure. 1.5.5. Bismuth The use of Bi salts for treating peptic ulcers is becoming widespread as are fears for the toxic effects of this treatment. Methods for measuring Bi in serum and urine are therefore becoming very relevant. In this review year methods using ETAAS and HGAAS feature. Dean et al. (931848) deproteinized serum with HN03 and determined Bi in the supernatant by ETAAS with a modifier of Pd Triton X- 100 and NH~NOJ. The Pd allowed the ashing temperature to be increased from 700 to 1030 "C. Urine samples were diluted with H20 and treated with the modifier. Platinum was the modifier used by Slikkerveer et al. (9213 169) in their method for whole blood and serum.They found it necessary to extract the Bi from the matrix with APDC into IBMK to avoid spectral and vapour-phase interferences. The extract was dried and the residue dissolved in the modifier solution of Pt. They found that blood samples needed to be collected in glass tubes and stored at -20 "C. To determine Bi in a range of biological materials including serum urine and bile by HGAAS Wan and Froomes (92/2438) digested samples in HN03 took the sample to dryness and redissolved in dilute HC1. On reduction with NaBH the hydrides were produced and swept with a flow of N2 into the atomization cell. The LOD was 0.14 pg l-l superior to that obtained with theJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 107R ETAAS procedures above.No significant interference was found. 1.5.6. Boron Little is known about the role of B in human nutrition. Recent studies using ICP-MS have laid the foundation for stable isotope studies. Boron concentrations in blood plasma and CRMs were determined by Smith et al. (92/25 13) with direct injection nebulization. Samples were fused with Na2C03 and the B separated by ion exchange before determination. Isotope ratios could be determined with a precision of 0.4-1.5% RSD. The B concentration of pooled human plasma was 24 pg 1-l. Yanderpool and Johnson (921C3449) developed methodology to study ab- sorption and excretion of B in rats. The diet contained loB either as boric acid or in broccoli grown hydroponically with loB as the main source of B.Urine and faeces were collected freeze dried and digested with microwave heat- ing. Both total B and isotope ratios were determined by ICP-MS with Be as internal standard. Surprisingly re- tention of 1°B from broccoli was low but high from boric acid. Determination of B in clinical materials by ETAAS is difficult as B is poorly atomized. Littlejohn et al. (931C7) found that it was improved by a Ca-Mg modifier. 1.5.7. Bromine A study by Vandecasteele et al. on the measurement of Br in serum by ICP-MS was published (92/1257). Serum was diluted 1 f 4 or 1 + 9 with 0.14 mol 1-I HN03 containing indium as an internal standard. To avoid overlap with the 40AfloAr peak 79Br and 81Br were measured with the width of the peak at 5% of maximum reduced to 0.61 u. Results obtained by using the two isotopes gave results which agreed well with each other. For the Versieck second generation serum RM values of 47.2+ 1.2 and 47.4a 1.7 pg g-l were obtained using 79Br and 81Br respectively.These results agreed well with those obtained by NAA and PIXE. Corrigan et al. (93/4 15) applied their method using ICP- MS to ascertain whether there was any relationship between plasma Br concentrations and lipid profrles in elderly patients. High density lipoprotein (HDL) cholesterol very low density lipoprotein (VLDL) cholesterol and triglyceride concentrations in plasma were inversely correlated with plasma Br Concentrations. They concluded that a com- pound in plasma containing Br was of importance in lipid metabolism. 1.5.8. Cadmium A variety of methods have been used in recent reports to overcome the interference of the matrix in the deterrnina- tion of Cd in urine by ETAAS.Chen and Zhu (931513) adopted a familiar approach of using an (NH4)2HP04-HN03 modifier. A tantalum-foil lining was inserted into the graphite tube to extend its lifetime. Probe atomization was adopted by Gayon and Sanz-Medel (931C74) to allow determination without a modifier. De Benzo et al. (92/C3654) applied selective volatilization from a L'vov platform to separate the Cd and background peaks with the intention of calibration with aqueous standards. This approach and others involving the addition of modifiers had been tried by DHaese et al. (9213865) who found they did not give the required accuracy and preci- sion. They found that the major problem of inadequate correction of the high background by the deuterium-arc system could be overcome by coating the L'vov platform with molybdenum.The use of a NH4H2P04-HN03 modi- fier eliminated the problem of multiple peaks. Even so aqueous standards could not be used for calibration and matrix matching was adopted. An alternative approach is to determine Cd in urine by ICP-AES. The technique requires samples to be preconcen- trated to give adequate sensitivity. Espinosa Almendro et al. (931C78) used the chelating agent 1,5-bis(dipyridyI- methylene) thiocarbonohydrazide to extract Cd from urine directly into IBMK and obtained an LOD of 0.1 pg 1-l. For the determination of Cd in blood D'Haese et al. (9213865) adopted the same treatment as they used for urine (described above).Samples were diluted 1 + 4.8 with the modifier and the Cd determined after calibrating with standards of Cd in blood. Results on the BCR Bovine Blood CRMs showed good agreement with the certified values. Results obtained on a spectrometer with deuterium-arc background correction were compared with those obtained on an instrument with Zeeman-effect background correc- tion. The good agreement between the two sets of results showed that the treatment they had adopted satisfactorily overcame background interference. Vahter et al. (9214058) described the methods they used in a study of personal exposure to Cd. Diet breath-zone air blood and faeces were collected from a group of female non- smokers. Blood samples were deproteinized with HN03 and determined by ETAAS. Faecal samples were dry-ashed and the residue dissolved in 1 moll-' HN03 for analysis by FAAS.The amount in faeces was considered to be a useful indicator of total ingested Cd. Diet was the main source of Cd. 1.5.9. Calcium Stable Ca isotopes measured by TIMS were used in two studies of human Ca metabolism. Price et at. (92/1503) followed the kinetics of Ca absorption over 24 h in volunteers given 44Ca and natural Ca orally and 42Ca intravenously. Similar studies were made by Yergey et al. (921 1507). In both studies precision of measurement was around 1% RSD. A method for the measurement of ionized Ca using a microcolumn of cation-exchange resin and FAAS was developed by Hewavitharana et al. (9213165). At a high electrolyte concentration (provided by 0.75 mol 1-1 NaN03) the Ca sorbed on the column was proportional to the free Ca in solution.The Ca on the column was eluted with HN03 directly into an AA spectrometer. The method was consi- dered promising for measurement of ionized Ca in biological systems. 1.5.10. Chromium Methods for the determination of Cr in whole blood plasma and erythrocytes by ETAAS were described by Lewalter et al. (92/2260) in a general review concerned with assessment of occupational exposure. The method described by Paschal and Bailey (9212639) for the determination of Cr in urine by ETAAS is little different from others in the literature. Samples were diluted 1 + 1 with 2% v/v HN03-0.001% m/v Triton X-100 and measured using atomization from a pyrolytic graphite coated graphite tube with background correction by the Zeeman-effect and calibration with simple aqueous stan- dards.The LOD was 0.5 pg 1-*. Da Silva et al. (931C143) used Mg(N03)2 as modifier but no advantage was stated. Chen et al. (921 19 12) preconcentrated the Cr by coprecipi- tation with Fe at pH 9.0. Only Crnl is precipitated in this way allowing speciation to be performed. To obtain total Cr the samples were digested with HN03 and then treated with Na2S03 to reduce Crw to CrI". Mean normal urine Cr Concentrations were quoted as 8.6 pg 1-l with 5.6 pg 1-l as C F . These values seem too high. Most workers find mean108R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VQL. 8 normal urinary Cr concentrations to be around 1 pg 1-I or less. The study of Da Silva et al.(93/C 143) showed a strong correlation between urinary Cr concentration in workers and the concentration of Crw in the air of nine chrome plating plants in Sao Paulo Brazil. Interestingly 60% of the workers in hard chrome plating plants had perforation of the nasal septum one of the signs of more advanced Cr toxicity. Although most studies relate to its toxicity others continue the search for the role of chromium as an essential element. Morris et al. (92/C4588a) using determination by ETAAS found that plasma Cr concentrations in nine volunteers were approximately constant during sleep (mean f SD 0.35 f 0.02 pg 1-*) but declined after breakfast reaching a minimum of 0.23 f 0.15 pg 1-l immediately after lunch. Plasma Cr concentrations were inversely correlated to plasma insulin concentrations (r= -0.35). 1.5.1 1.Cobalt Interferences in the determination of Co in serum by ETAAS were studied by Bulska et al. (92/266 1). Chlorides phosphates and sulfates decreased signals. Magnesium hydrogen phosphate and Pd were succesful modifiers. Dilution with 0.1 mol 1 - I HN03 using the Ca and Po4’- naturally present in serum as a modifier was a promising approach. 1.5.12. Copper Copper absorption in five young men on a diet low in zinc was studied by Taylor et al. (9212694) using the stable isotope T u as a tracer and measurements by TIMS. Their measurements revealed that the absorption of Cu was unaffected by zinc deprivation or zinc repletion. The plasma Cu concentration however fell during zinc depri- vation despite consistently positive Cu balances.Ting et al. (92/1403) studied Cu absorption and excretion in the mouse and rat using measurements by ICP-MS. The stable isotope T u was introduced into the drinking water. Isotope ratios were measured with a precision of better than 1.0% in blood plasma and liver. The increased concentrations of Cu in the cerebrospinal fluid of patients with Parkinson’s disease were measured by DCP-AES by Belliveau et al. (92/4420). A comparison of the relative magnitude of matrix interferences in this technique was made with those in ETAAS. 1.5.13. Indium The determination of In in urine by ETAAS was described by Bertram and Mueller (92/2261) in a review for assess- ment of occupational exposure. 1.5.14. Iron Inductively coupled plasma MS was used by Whittaker et al.(92/C340 92K405 9214603) to measure Fe isotope ratios in whole blood in order to measure absorption from diet. The stable isotope 57Fe was administered to subjects orally and 58Fe was injected intravenously. The ratios 57Fe:56Fe and 58Fe:56Fe had to be measured with a precision better than 0.9% RSD in order to get adequate precision in the estimation of Fe absorption. The final precisions achieved were 0.22 and 0.47% respectively. The high Fe concentrations in whole blood allowed conventional sample introduction by nebulizer and thus gave greater precision than previous measurements which had attempted to determine Fe isotope ratios in serum by ETV-ICP-MS. To determine Fe in serum by ETAAS Komarek et al. (9214060) diluted samples 40- or 20-fold with 0.01 moll-’ HCl in 0.1 Oh v/v Triton X- 100.Prior deproteinization with TCA allowed non-haemoglobin Fe to be determined. Urine Fe was first extracted with APDC into IBMK and 20 pl of the organic phase were injected into the furnace. Precision values quoted were 0.6% for serum with an Fe concentra- tion of 1.80 mg 1-l and 5.0% for 40 pg 1-I of Fe in urine. Iron in children’s cerebrospinal fluid was measured by Gruener et al. (92/2664) using ETAAS with Mg(N03)2 as a modifier and matrix-matched calibration. Patients with viral meningitis had higher Fe transferrin and ferritin concentrations in their cerebrospinal fluid than healthy children of the same age. 1.5.15. Lithium The work of Vanhoe et al. (92/1287) on the determination of Li in serum by ICP-MS was published.Samples were diluted with dilute HN03 and beryllium added as internal standard Several biological RMs were analysed to test the accuracy of the method. In healthy individuals measured serum Li concentrations ranged from 0.22 to 0.97 pg 1-I. 1.5.16. Lead For mass screening of blood Pb concentrations in children two laboratories (92/2834 93/406) adopted sampling blood by fingerprick and spotting the blood onto filter-paper. The dried spots could then easily be mailed to the laboratory for analysis. This is not a new idea but is seen as effective for mass screening particularly for neonates as the technique is already widely used for detecting inborn errors of meta- bolism. These dried blood spots are apparently stable for at least six months (92/2834).Verebey et al. (92/2834) punched the blood spots out of the paper and determined Pb in them by Delves’ cup AAS. The cup was first pushed near the flame so that the heat ignited the paper. Within a few seconds the paper was burnt off and the cup was then inserted in the flame for measurement of Pb. The time of analysis 15 s illustrates the speed of the Delves’ cup approach. The average RSD was 8.3%. As the method could only measure down to 40 pg l-l it was only suitable for screening for Pb poisoning. The technique using ETAAS adopted by Wang and Demster (931406) was more time-consuming but allowed measurement of normal concentrations. Lead from the punched-out blood spots was extracted by vortex mixing with a solution of 1.25% m/v (NH4)2HP04-0.50/o v/v Triton X-100 for 30 min and determined by atomization from a platform with background correction using the Zeeman effect.The method was calibrated with RMs spotted onto paper and treated in the same way. For 425 newborns in the area centred on Toronto Canada the meanf SD blood Pb was 0.19 f 0.13 pmol l-l. The LOD however was 0.05 pmol 1-l and the precision at 0.12 pmol 1-I was poor at 45% RSD. At just above their defined toxicity level of 0.50 pmol l-l the precision only improved to 20%. The poor precision was ascribed to the variability of absorption on the filter-paper. With the use of a slotted tube atom trap FAAS can be used for determination of higher than normal blood Pb concentrations as Alonso-Fernandez et al. (9213 15 1) de- monstrated. Samples were digested with HN03 in a PTFE microbomb. The LOD was 0.33 pmol 1-l and the RSD at measurable values was 9.5%.Results correlated well with results by a method based on ETAAS. Probe atomization in ETAAS used by Vasconcelos et al. (9212529) to determine Pb in blood was reported to give results free of interference allowing aqueous calibration. Samples were simply diluted 10-fold with 0.05% Triton X- 100. A paper by D’Haese et al. (92/3865) entitled ‘Elimina- tion of Matrix and Spectral Interferences in the measure- ment of lead ... in Blood.. . ’ reported a final methodJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 109R which used matrix-matched calibration curves; surely this implies that matrix interferences were not eliminated. The use of a NH,H2PO4-HNO3-Triton X- 100 modifier over- came the problem of double peaks for Pb in blood but overcorrection by the deuterium-arc background correction system was still seen.Coating the L'vov platform with molybdenum and modifications to the furnace programme removed this. Comparison of results with those obtained on an instrument with Zeeman-effect background correction confirmed the absence of problems due to correction of background. The accuracy of the method was confirmed by good results in the Trace Element Quality Assurance Scheme run by the University of Surrey Guildford UK. Total reflection XRF was applied by Ayala et al. (92/2781) to the determination of Pb in blood. A small volume (2 pl) was pipetted onto quartz glass dried and ashed with a low temperature oxygen plasma asher before X-ray irradiation. The LOD was 40 pg 1-l for a measure- ment time of 1000 s.The speciation of Pb in blood was studied by Gercken and Barnes (92/C863 92/1225) using a combination of SEC and ICP-MS. In human serum Pb was mainly attached to caeruloplasmin but in red cell haemolysate the major fraction was found at 250 ku with minor fractions associated with haemoglobin and carbonic anhydrase. Yamamura and Arai (92/1909) studied the speciation of Pb in urine after exposure to tetramethyllead. Tetramethyl- lead trimethyllead dimethyllead and inorganic Pb were selectively extracted into IBMK and the Pb determined by FAAS. Recovery of each of the species was 98-99%. A study on rabbits showed that one day after they were injected with tetramethyllead 67% of the Pb excreted was present as dimethyllead but this decreased and the proportion of trimethyllead in the urine increased to 73% after seven days.Omokhodion and co-workers (92/ 1908 9212069) evalu- ated the use of sweat Pb measurements for measuring Pb exposure in the tropics. Sweat blood urine and saliva were collected from 24 healthy subjects and the Pb concentration measured by AAS. Mean sweat Pb concentration was 5.2 pg 1-l compared with a mean blood Pb concentration of 86.2 pg 1-I. Saliva Pb concentrations (mean 4.8 pg 1-l) correlated poorly with blood Pb concentrations but sweat Pb levels correlated reasonably well (r= 0.72). In workers in a battery manufacturing plant sweat Pb levels ranged from 72 to 256 pg 1-l (compared with blood Pb concentrations of 130-360 pg 1-I).However contamination of the sweat from dust on the skin was found to be a problem in the application of this measurement. In an assessment of personal exposure to Pb under normal environmental conditions Vahter et al. (92/4058) mea- sured Pb in breathing-zone air (by collecting particulates on air filters) in blood in diet and in faeces. Air filters were digested with HN03-HC104 and blood samples were deproteinized with 0.8 mol 1-l €€NO3 for measurement by ETAAS. Diet and faeces were dry-ashed and the residue dissolved in dilute HN03 for measurements by ETAAS and FAAS respectively. It was found that the main source of exposure to Pb was diet (average 26 pg per day) and that faecal Pb excretion was a useful guide to total ingested Pb.1.5.17. Magnesium The straightforward way in which ICP-MS can be used for stable isotope measurement of Mg absorption in humans was demonstrated by Cary et al. (92/2895). Recoveries from solutions spiked with 2sMg and 26Mg were similar for Mg standards in 1% HN03 and for diluted serum urine and wet-ashed faecal digests in 1% HN03. With stabilization of the Ar flow with a mass controller a precision of measure- ment of 0.5% RSD was reached. Nozue et al. (93/4 1 3) determined Mg in mononuclear cells by FAAS after separation from blood on a discontinuous Percoll density gradient. The method developed was claimed to be simpler and more precise than previous methods. 1.5.18. Manganese For the difficult determination of normal Mn concentra- tions in serum ( t 1 . 5 pg l-l) Neve and Leclerq (92/1839) diluted samples 1 + 1 with 8Yo v/v Triton X-100-5% m/v EDTA for measurement by ETAAS using a pyrolytic graphite coated graphite tube.No advantage was found from using platform atomization. Calibration was by standard additions or matrix-matched standards. Blood samples were collected through PTFE cannulae to prevent contamination from stainless-steel needles. For 3 1 healthy adults a mean f SD of 10.8 +- 3.0 nmol 1-I was obtained for serum Mn concentration. Mullins et al. (92/C748) evaluated a new commercial forked platform and graphite tube in ETAAS for the determination of Mn in urine. Multiple injections were used to concentrate the sample to give an LOD of 0.3 pg 1-1 in urine. The range of concentrations found in samples from normal subjects was from (0.3 to 1.6 pg 1-I.1.5.19. Mercury Moreton and Delves (92/C366) described the determina- tion of Hg in urine and whole blood by ICP-MS. Samples were diluted 35-fold with a solution containing (NH,)2H2EDTA-NH4H2P04-NH40H-Triton X-1 00 and tellurium as internal standard and measured against ma- trix-matched standards. A small amount of a disinfectant was added to all diluted samples to destroy human pathogens. The sample treatment helped to reduce sample wash-out time to less than 2 min. Signals from 199-202 u were summed enabling an LOD of 1 pg 1-l to be reached with a linear range up to at least 1000 pg 1 - I . Reproducibil- ity was around 8.5% RSD. The determination of total Hg in whole blood by ETAAS was described by Emteborg et al. (92/C754,92/4652). After treatment with dilute HCl to break Hg-protein thiol bonds the Hg was extracted into toluene with NaDDC.Back extraction of the Hg into a dilute HC1 phase overcame problems of high background absorbance found when the organic phase was measured directly. Palladium was used as the modifier. The same group (92/C872 9214105 93/Cl01) studied the speciation of Hg in blood by capillary GC on a non-polar DB1 column with an MIP-AE detector. The Hg species were extracted as their complexes with NaDDC into toluene and butylated with a Grignard reagent. The butylation step overcame problems associated with previous procedures using separation as halides. Calibration was made with blood standards spiked with inorganic Hg and methylmercury. For 60 persons not occupationally exposed to Hg most of the Hg in their blood was present as methylmercury (6.42k4.06 pg 1-l; meankSD) and a smaller amount as inorganic Hg (1.37 -+ 0.96 pg 1-I; mean f SD) Recent developments include FI procedures for the determination of Hg by CV'S.Both Burguera et al. (92/C3530) and Tyson and co-workers (93/C64 93/C99) carried out prior oxidation of urine with KMnO off-line. The former group also analysed blood samples directly after dilution with an antifoaming agent and water. The samples were injected into a flowing stream of water which was mixed with 4 mol 1-l HN03 and 0.3% m/v NaBH,. The evolved Hg was separated in a gas-liquid separator and passed to a quartz cell in an AA spectrometer for measure-110R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 ment. The LOD was 0.1 pg 1-I. The procedure of Tyson et al. (93/C64 93/C99) was similar but included a gold gauze trap to give additional sensitivity. An important stage in the determination of Hg by CVAAS is the preliminary digestion of samples without loss of Hg. Livardjani et al. (921308 1) optimized the conditions for digestion of blood. Complete mineralization was achieved with a mixture of HNO and H2S04 after heating at 60 "C for 10- 15 min. Bomb digestion was examined by Sanchez et al. (93/C118). For microwave heating samples were digested with HN03 or H2S04-H202 for 90 s whereas for conventional heating digestion was carried out with HN03 and/or HC104 at 125 "C for 4 h. Recoveries were 95+5Oh and 98+5% for conventional and microwave heating respectively and accuracy was further demon- strated by a correct result for NIST SRM Albacore Tuna.Vesterberg (92/4389) described recent modifications that had been made to a well-tried CVMS method used for the determination of Hg in blood plasma and urine. An LOD of 5 nmol l-* was achieved in all matrices. The RSD within and between batch was for blood 4.7 and 9.5% respectively at 20 nmol l-I and for urine 1.8 and 5.2% respectively at 57 nmol l-I. The unusual but apparently effective determination of Hg in blood and urine by ICP-AES was described by Buneaux et al. (93/811). Mercury generated in a continuous flow system with dilution in an ammonia buffer and reduction with NaBH was collected in a reactor and then introduced into the ICP not through the nebulizer but through the Ar supply.Prior digestion of samples was not necessary. 1.5.20. Molybdenum The difficulties of determining Mo in biological materials was stressed in a recent review (92/3238). The refractory nature of Mo makes determination by ETAAS difficult. Bermejo-Barrera et al. (92/20 1 5 ) studied a range of modifi- ers for determination of Mo in human serum. Magnesium nitrate and BaF were found to be the best modifiers. Palladium-based modifiers did not remove matrix effects. 1.5.2 1. Nickel A proposed recommended method for the determination by ETAAS of Ni in the blood of persons occupationally exposed to Ni was presented by Angerer and Heinrich- Ramm (9212262). Many workers find it necessary to include a solvent extraction step to increase sensitivity for the determination of Ni.The obvious chelating agent is dimethylglyoxime as was used by Senft et al. (9214463) for the determination of Ni in urine serum hair and fingernails. Samples were digested with HN03-H202 and the dimethylglyoxime com- plex extracted into IBMK for measurement of Ni by ETAAS. They used the method for the analysis of samples from workers at a plant producing Ni compounds and from a control group. Vereda Alonso et al. (92/2014) explored the use of the reagent 1,5-bis(di-2-pyridylmethylene) thio- carbonohydrazide. Extraction of the Ni complex at pH 3 was followed by determination by ICP-AES. The overall LOD was 0.5 pg i - I . The method was applied to the determination of Ni in urine and tissue digests. 1.5.22. Platinum Several different approaches to the determination of Pt have been developed using mass spectrometric techniques.Evetts et al. (92/1502) used GDMS with bismuth as an internal standard to measure urine Pb and Pt concentra- tions in their study on the mobilization of Pb by the drug Cis-platin in cancer patients receiving chemotherapy. Small amounts of the Pb stored in the body were apparently displaced by the Pt complex. Isotope dilution GC-MS was applied by Aggarwal et al. (92/1536) to the determination of Pt in urine. The Pt was complexed with lithium bis(tri- fluoroethy1)dithiocarbamate to form a volatile complex that was enriched with 19,Pt. After separation on a DB-1 fused silica capillary column quantification was performed by use of MS with selected-ion monitoring.A precision of l0h RSD was obtained for about 10 ng of Pt. For the determination of Pt in serum and cerebrospinal fluid Casetta et al. (9214733) diluted samples 1 + 19 for measure- ment by ICP-MS. The LOD corresponded to 0.4 pg 1-' in the sample. Precision was better than 2% RSD. Chen and coworkers (9211 792,932254) used ETAAS for the determination of Pt in plasma urine plasma ultra- filtrate and tissues. Plasma and ultrafiltrate were diluted 1 + 3 and 1 + 1 respectively with 0.25% v/v Triton X- 1O0-lo/o v/v HNO,; urine was diluted 1 + 3 with H20. The LOD was 5 pg I-'. The object of the study of Ikeuchi et al. (92/4384) was to be able to measure a new Pt-based drug cis-diammine(glycolato)platinum in pharmacokinetic studies. Blood and tissues were first wet ashed with HN03-HC104-H2S04.Platinum was extracted from the digests or from acidified urine with APDC into IBMK and determined in the solvent layer by ETAAS. Detection limits were 50 pg I-' in plasma and 100 pg I-' in urine. This is apparently a more complex procedure than other direct methods in the literature [as for example from Chen's group above (9211792 92/2554)] with no increase in sensitivity from using the solvent extraction step. 1.5.23. Selenium The determination of Se in plasma and whole blood by XRF spectrometry was reviewed by Robberecht et al. (92/4286); normal values obtained by this technique were compared with values obtained by other techniques. Most procedures for HG determination of Se in blood and urine use prior digestion with a mixture of acids e.g.HC104-HN03 as used by Shen (9213938). D'Ulivo et al. (921C3635) demonstrated a simpler digestion with HBr-Br2. Tests on organoselenium compounds showed that the most resistant form the trimethylselenonium ion was completely broken down after a 90 min digestion. Subse- quent determination was by AFS. The excellent sensitivity obtained by laser-excited elec- trothermal AFS for Se was demonstrated by Heitmann et al. (92/2085). With Pd as a chemical modifier for blood an LOD of 8 ng I-' was achieved. Electrothermal vaporization was used by Hulmston et al. (92/1461) in the determination of Se in serum by ICP-MS. Chemical modifiers as in ETAAS prevented volatilization of Se at lower temperatures. However with an LOD of 2 pg l-' there appears to be no advantage over determina- tion by ETAAS.In E T A S overcorrection of background absorbance can still occur even when Zeeman-effect background correction is used as Radziuk and Thomassen showed (92/465 I). The key to removal of interference seems to be the type and amount of modifier. For the determination of Se in urine with Pd as modifier for example increasing the amount of Pd used resulted in an increasing delay and a reduced amount of P atomized and hence removal of overcorrec- tion. Addition of 300-500 pg of Pd per injection was recommended. Nickel as a modifier was effective in reducing background absorbance from urine and increasing the P atom concentration but at amounts greater than 250 pg spikes were seen on the peak profile. The effect of a range of modifiers Al Ca Eu La Mg Ni and Pd on different forms of Se including selenomethionine and trimethylselenonium iodide was studied by Docekalova etJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 l l l R al. (9212622). All were effective as modifiers and would produce a similar response if sufficient excess of the modifier was added. A mixture of Pd and Mg(N03)2 with a considerably larger amount of the latter than usual was proposed as the most efficient modifier. The greater difficulty of stabilizing Se as the trimethylselenonium ion shown in this work was confirmed by Laborda et al. (931C75). Although the use of Ni as a modifier was effective in obtaining a similar response from Se as selenite and trimethylselenonium the use of Pd even with prior pre- reduction gave for trimethylselenonium about 50% of the response obtained for selenite. Other members of the platinum metals Rh (9214543) and Ir-Mg (92/1722) have been used successfully as modifiers.The latter was used in the determination of Se in whole blood in which an oxygen ashing step prevented the formation of carbonaceous residues. Gardiner et al. (931C70) used Pd as a modifier in the determination of Se in plasma using platform atomiza- tion deuterium-arc background correction and calibration with standards containing 0.1% v/v Triton X-100 and physiological concentrations of albumin phosphate cal- cium and sodium chloride. A similar method described by Forrer et al. (92/2900) was used for the determination of serum Se concentrations in various animal species includ- ing man.Carnivores had the highest serum Se concentra- tions (e.g. cats 3.60-10.09 pmol 1-l) and ruminants the lowest (e.g. cattle 0.10-0.82 pmol 1-l). Methods for the determination of Se in ocular tissues and fluids by ETAAS were developed by McGahan and Grimes (9214448). The mean Se concentration in aqueous humour was 8 pg l-l lower than that in plasma a fact which was ascribed to the lower protein concentration to which Se is bound. Concentrations in the cornea iris lens and retina ranged from 0.23 to 0.41 pg g-' wet mass. The higher absorption of Se as selenomethionine than as selenite was confirmed in a study by Moser-Veillon et al. (921C801 9214098) on lactating and non-lactating women. Using 74Se and 76Se to tag selenomethionine and selenite respectively in the diet they collected milk urine faeces and blood samples from the women and analysed them for natural Se 74Se and 76Se by IDMS.Samples were digested with HNO3-H3PO4-HzO2 and the Sew reduced to SeIV with HCl. After chelation with 4-trifluoromethyl-o-phenylenedi- amine the Se was extracted into CHC13 and injected into a gas chromatograph coupled to a mass spectrometer. The absorption and retention of Se from selenomethionine did not seem to be altered by lactation. Cow's milk was shown by Gropper et al. (9211768) to be a better source of Se for infants than infant formula. The mean plasma Se concen- tration of infants fed cow's milk (39 pg 1-l) was greater than that of the group fed with infant formula (31 pg 1-l) which related to the difference in daily dietary input (34 and 22 pg of Se respectively).Studies have shown lower Se concentrations in various disease states. A significant difference in serum Se concen- trations between elderly patients after myocardial infarc- tion (34 k 12 pg 1 - I ) and healthy controls (45 2 9 pg 1-l) of the same age led Adameckova et al. (931C870) to suggest that Se depletion was a risk factor for myocardial infarc- tion. The mean serum Se of patients with hepatocellular carcinoma (92.2 pg 1-l) was lower than that of controls (1 24 pg 1-l). The Se levels measured by ETAAS were positively correlated to concentrations of albumin total protein and haemoglobin (931738 931743). Patients with liver cirrhosis and gastrointestinal cancer also were shown to have lower Se levels than controls (931746).1.5.24. Silicon Inductively coupled plasma AES is probably the most straightforward technique for measuring Si. It was used by Tanaka et al. (92/1879) to determine Si concentrations in the serum of mothers and in their breast milk in the postpartum period. Little change in serum Si was seen (geometric mean about 9.8 pmol 1-I one week and 8.2 pmol I-' one month after delivery) and breast milk concentrations remained similar (corresponding figures 6.4 and 6.2 pmol l-l respectively). Determination by ETMS is more difficult. Holden et al. (931C7 931C72) found that Ca was a suitable modifier for the determination of Si in biological fluids and tissues. Studies using SEM on the surface of the platform helped to elucidate the mechanism of atom formation and the effect of the modifier. The value of the Ca modifier was confirmed in the work of Lin et al.(921C4157). In addition tungsten- coated tubes gave greater sensitivity and precision than pyrolytic graphite coated graphite tubes. The technique was used to determine Si in blood of 3 1 3 healthy adults giving a range of 2.16-8.52 mg 1-l. 1 S.25. Silver To measure Ag in the blood urine and tissues of burns patients who had been treated with silver sulfadiazine cream Wan et al. (92/2915) developed methods using ETAAS. Ammonium nitrate was used as modifier and calibration was performed with standards containing bovine serum albumin Na K C1 and HC03-. In subjects without medical or industrial exposure to Ag plasma Ag concentra- tions were t 2 . 3 pg l-l mean urinary excretion was 2 pg per day and in both kidney and liver mean concentrations were 0.5 pg g-l.In treated bums patients the plasma Ag concentration could reach 310 pg 1-l and urinary Ag excretion reached a maximum of 400 pg per day. 1.5.26. Surfur To determine sulfate in serum indirectly Chatteraj and Das (921C456 92/4095) formed an ion-association complex in neutral medium with the sulfate copper and neocuproine which was extracted into IBMK and the copper in the extract was measured by FAAS. The extraction in the presence of a polar material methanol achieved an efficiency of more than 98%. The LOD was 3.2 pg 1 - l ' better than that achievable by ion chromatography. Sulfate con- centrations in jaundiced patients (50.3-62.5 mg 1-I; n=6) and diabetic patients (83.5-155.6 mg 1-I; n=6) were higher than those in healthy subjects (35.4-43.3 mg 1-l; n=6).1.5.27. Tellurium Kobayashi and Imaizumi (921C3560) compared determina- tion of Te in urine by HGAAS and ETAAS. A urine sample (50 ml) was digested with HNO3-HC1O4 evaporated to dryness and redissolved in 7 moll-' HC1. Direct determina- tion by ETAAS gave low recoveries and inadequate sensitivity. Solvent extraction into IBMK gave improved sensitivity and correct recoveries. Best sensitivity was obtained by HGAAS. This latter method has been pub- lished in some detail (9212479). In urine samples from unexposed subjects concentrations of Te ranged from 0.02 to 1.63 pg 1-l. The method of Kron et al. (92/2653) for the determina- tion of Te in blood by ETAAS was based on the same principle i.e.wet digestion with HN03 followed by reduction to Tew and extraction into IBMK. Calibration was by standard additions. In order to measure stable isotopes by SIMS the extraction technique was again used but the Te was back-extracted into distilled water the water evaporated off and the residue redissolved in 0.5 mol 1 - I KOH. Small aliquots were deposited onto graphite discs for determination by SIMS. Studies on rabbits of the112R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 kinetics of administered Te showed that results by stable isotope measurement using SIMS were in good agreement with results obtained with radioactive tracers using gamma- ray spectrometry for measurement. 1.5.28. Thallium To determine T1 in urine by ETAAS Collett and Jones (92/2436) digested urine with HN03-H202 and evaporated the digest to near dryness.The residue was redissolved in 30% v/v HC1 and extracted into di-isobutylketone. Tube wall atomization was used with the addition of reduced Pd as modifier. The LOD was 0.2 pg 1-l. The effectiveness of Pd as a modifier for the determination of T1 in blood and urine by ETAAS was examined by Yang and Smeyers- Verbeke (93/414). A mixture of Pd with NH4N03 was more effective in removing chloride interference than Pd with Mg(N03)2 and allowed T1 to be determined directly in blood diluted 1 +9 with calibration with aqueous stan- dards. For urine however calibration by standard addi- tions was necessary. 1.5.29. Tin Direct determination of Sn in blood and tissue digests by ETAAS was described by Itami et al.(92/2833) with an LOD of 2 pg 1 - I . Interferences were suppressed by the addition of ascorbic acid. 1.5.30. Titanium In order to study Ti concentrations in the serum of patients who had total hip replacement using Ti alloy components Skipor et al. (92/C3744) developed an ETAAS method. They found that in order to get good precision attention was required to reduce carryover ash build-up and graphite tube and ring deterioration. The sample was atomized from the wall of a pyrolytic graphite coated graphite tube and calibration was by matrix-matched standards. The detec- tion limit was 2 pg 1-' and the mean recovery 101O/o. The mean serum Ti concentration in patients with loose prostheses (1 1.9 pg 1-l) was higher than in patients with stable prostheses (4.8 pg 1-I).1.5.3 1. Uranides The use of ZCP-MS to measure the uranides in the urine of workers in the nuclear industry has been explored at a number of centres. At Oak Ridge National Laboratory USA the uranides were collected on a column sequentially eluted and measured using ETV to obtain sufficient sensitivity (92K3420). Similarly at Harwell Laboratory UK (93/C30) ETV was used to obtain a detection limit below 0.1 ng 1-I for Pu. Ultrasonic nebulization was tried by Wyse et al. (93/C307); this gave the precision of conventional nebulization but with LODs 10-50-fold bet- ter. Allain et al. (92/4711) determined U in plasma and urine down to 35 ng 1-* by conventional nebulization for assessment of occupational exposure. 1.5.32.Vanadium Arbouine and Smith (92/2434) determined V in urine by ETAAS after chelation with cupferron and extraction into IBMK. The detection limit was 0.1 pg 1-l. In unexposed controls urine V concentrations were less than the LOD but in foundry workers producing a ferrovanadium alloy and cleaners of oil-fired boilers mean concentrations were 3.6 and 0.7 pg l-l respectively. The method of Chen et al. (92/4359) also using ETAAS specified prior digestion with HN03-HC104 followed by extraction with APDC into CHC13. 1.5.33. Zinc 'To determine the stable isotopes of Zn in biological samples by isotope dilution ICP-MS for tracer studies Patterson et d. (93/C368) separated the Zn from the matrix by extrac- tion with diammonium diethyldithiocarbamate into CHC13 to avoid polyatomic-ion interferences.The Zn was back- extracted into dilute HN03. A similar approach was reported by Amarasiriwardena et al. (92/C34 10) using APDC as a chelating agent. They found that small amounts (of the solvent CC14 would dissolve in the dilute HN03 giving interference from C1 species. To remove the residual CC14 the solution was evaporated to dryness. Their methods intended for studies on pre-term infants encom- passed blood urine faeces and food. The solvent extraction procedure was found to be unnecessary for the faecal samples. Both the above groups reported precisions better than 1% for the determination of the isotope ratio. Blood spots (50 pl) on filter-paper were studied by Fan et al. (92/2648) as a way of collecting samples for blood Zn determination by FAAS. After drying the blood stain was cut out.Direct extraction of the Zn with 10% HC1 for 24 h was found to be simpler than dry ashing. A sample stored for six months showed no change in measured Zn concen- tration. Precision was in the range 3.5-6.0%. A method for the determination of Zn in human milk by ETAAS was reported by Arnaud et al. (92/ 187 1 92/2620). Samples were diluted 1 + 99 with 0.1% Triton X-1 00 and determined against aqueous Zn standards similarly diluted. The analytical recovery increased with greater dilution but so also did the imprecision. The dilution ratio chosen was a practical optimum. Better LODs were obtained with un- coated graphite tubes than with pyrolytic graphite coated graphite tubes. Results by this direct method were shown to be in good agreement with those obtained after wet digestion (92/187 1).1 .5.34. Multi-element determinations and studies Reports from Japan detail applications of simultaneous multi-element ETAAS. Kobayashi and Imaizumi (92K3580 931563) determined Cd Cr Ni and Bb in urine using Pd as a modifier. Samples were simply diluted 1 + 1 with distilled water and calibration was by standard additions. Ono (92/4446 92/4447) developed a method for the determination of Cd Co Cr Cu Mn Ni and Pb in urine using calibration with standard additions. The method was applied to the measurement of those elements in 334 urine samples from persons not occupationally exposed to these elements. Mean results expressed as a ratio to creatinine ranged from 0.440 pg g-l of creatinine for Cr in urines from males to 22.6 1 pg g-l of creatinine for Cu in the urine of females.To determine Cr Co Mo and Ni in serum workers at Hitachi (92/3243) deproteinized the serum and increased sensitivity by injection of five aliquots of 20 pl into the graphite tube. Calibration by aqueous standards gave acceptable accuracy. For determination of A1 and Mn samples were similarly deproteinized and a single injection of 10 pl was made. Samples were diluted 4- fold for Se determination. For Al Mn and Se standard additions calibration was used and for all elements the modifier was Pd. A rapid survey method for profiling trace elements in serum whole blood and saliva using semi-quantitative ICP- MS was developed by Vaughan et al. (92/1434). Samples of serum and whole blood were digested with HN03. Saliva samples were simply diluted 5-fold in 1Yo v/v HN03.Rhodium was added as an internal standard. ThirteenJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 113R elements in serum and 15 in blood could be consistently and reliably measured with a precision of around 20% RSD. Interferences for As Se and V were serious and so results for these elements were ignored. Results for Cr Fe and Ti needed to be interpreted with caution. Elements considered reliable included B Cu Fe Li Mg Rb Sr and Zn. Further details are available of the work by the Ghent group on determination of normal ultra-trace elements in human serum by ICP-MS (921C707 9212912). Values were ob- tained for B Ba Bi Cd Cs Li Mo Sn and Pb in the Versieck ‘second generation’ serum RM.All concentrations were less than 2 pg 1-l except B (about 20 pg 1-l) and Pb (about 4 pg 1-l). At these low concentrations special care had to paid to the stability of the blank signal and to the linearity of calibration at the lower concentration range. Park et al. (9211484) determined Cr Cu and Pb in NIST SRM Human Serum by ICP-MS after dilution of the sample 1 0-fold with H20. Calibration by isotope dilution for Cu and Pb and by standard additions for Cr Cu and Pb was used to evaluate results which were within the certified range. Shuttleworth (921C827) demonstrated the possibility of coupling LA-ICP-MS with electrophoresis for the study of separated blood serum. Direct elemental and isotope analysis of the species on the electrophoretogram could be made and elemental maps could be built up with the help of special computer software.As a further development in the application of FI to the determination of Ca K Mg and Na in serum by AAS Burguera et al. (9211773) described the use of a variable volume injector. The accuracy of injection of the device was demonstrated by injecting various volumes of standard solution into the flowing stream. Morisi et al. (92/2464) determined Ca K Mg and Na by ICP-AES in 24 h urine samples from nine-year old children and compared the results with those by FAAS. Agreement was generally good although results for both Ca and Na were statistically significantly different but still acceptable. To determine Cr Co and Mo in the synovialfluid of a patient with an artificial knee joint of cobalt alloy which had caused serious tissue reaction Lugowski et al.(9212858) developed methods using ETAAS. For Co and Mo three different methods of preparation were compared simple dilution with Triton X- 100 solution; microwave- assisted digestion; and conventional HN03-HC104 diges- tion. Results by the three approaches were comparable. The patient had elevated levels of Co Cr and Mo in both synovial fluid and blood. In a study of trace elements in the semen of infertile men Shinohara et al. (931748) measured 13 elements in 110 samples by AAS fluorimetry or colorimetry. In addition they measured sperm concentration motility (To) and abnormal morphology (O/O) in order to discover whether these factors were correlated to trace element concentra- tions.Only Se the concentration of which in spermatozoa was highly correlated to sperm concentration seemed to have an important role. In a study of serum Cu Mn Se and Zn concentrations measured by AAS in patients with chronic liver diseases Takikawa (9211 772) found lower than normal Se concentra- tions. Serum Zn was also low in patients with hepatocellular carcinoma and liver cirrhosis and serum Cu was higher than normal. Differences in Mn levels were not noteworthy. Inductively-coupled plasma AES was used by Koshinaga et al. (931739) to determine essential element concentrations in gallbladder and hepatic bile of patients with hepatobili- ary disorders. Of the many observations Cu was considered to play a role in the formation of black pigment stones as the concentration of Cu in gallbladder bile was higher than normal in the stone formers whether liver cirrhosis was present or not.In an extensive study of 21 elements in human saliva measured by XRF and NAA Zaichik and Bagirov (92145 1 7) found considerable diurnal variation requiring the time of day to be strictly defined. Neither age sex nor season influenced the element concentration except for Hg which was shown to increase in concentration in saliva with age. Parr et al. (9211824) described the results of their international collaboration on the determination of minor and trace elements in human milk from mothers in Guatemala Hungary Nigeria The Philippines Sweden and Zaire. Techniques used included AAS ICP-AES NAA colorimetry and potentiometry with ion-selective elec- trodes.The results on the Filipino milk stood out as having higher concentrations of trace elements such as As Cr and Pb than the other milk samples. They found that for all countries the actual daily intake of elements significantly exceeded the current dietary recommendations for three- month old babies and they called for a reassessment of dietary requirements particularly for Ca Cr Cu F Fe Mg Mn Mo P and Zn. Further work has been carried out by Caroli et al. (921C4247) on their assessment of reference values for the milk of urban mothers. Analysis was by ICP- AES after digestion of the samples. In a further study of trace element concentrations in cerebrospinal fluid (CSF) measured by ETAAS El-Yazigi et al. (9211887) produced data for Mn Pt and Sr in the CSF of patients with brain neoplasms leukaemia lym- phoma and controls.Manganese concentrations were lower in the CSF of leukemic patients whereas Pt levels were lower in the CSF of patients with brain tumours leukaemia and lymphoma. No difference in Sr concentra- tions amongst the groups were seen. Jiang et al. (9214560) also studied trace elements (Cd Cu and Mn) in the CSF of patients with brain tumours and measured in addition the serum concentrations of Cd Cu Mn Se and Zn by FAAS ETAAS or HGAAS. For patients with malignant brain tumours serum and CSF Cu concentrations were higher than in the other groups. Using all the data they prepared a set of discrimination function equations which could predict malignant and benign tumours with an accuracy of 8 1 %.An automated system for determination of stable isotopes of Ca Cu Fe Mg and Zn by TIMS using double ID was described by Turnlund et al. (9211401). Use of a multiple collector improved precision allowing measurement of isotope ratios with 0.1 To RSD and improved the speed of analysis. The system was applied to analysis of faecal urine and plasma samples following infusion and feeding of stable isotopes of Cu Fe and Zn. In a study of trace elements in patients with renal failure on haemodialysis Romero et al. (931C149) found higher than normal concentrations of Al Cu and V in whole blood. Blood samples were diluted with Triton X- 100 solution before analysis by ETAAS. Bone concentrations of Al Fe and V were also significantly increased.Iron concentrations in whole blood however were lower than normal. Whole blood concentrations of trace elements were seen as more meaningful than their concentrations in serum (92/C5 13). In a further study (92/C3557) they monitored the removal of Al Cu Fe Pb and Zn on treatment of patients on haemodialysis with the chelating agent desferrioxamine. Copper and Zn concentrations in blood were unaffected by the treatment but A1 and Pb increased. An increase in Fe was seen only in a patient with an acute haemosiderosis. Zhou et al. (92/4545) found that for mothers at deliv- ery cord blood concentrations of Ca Mg and Zn were higher than in the mother’s blood but Cu was lower. Measurements were by AAS. The high demand for Ca by the foetus was shown by the fact that the infant’s serum Ca always remained over 2.0 mmol 1-l even when the mother114R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 showed depletion with serum Ca concentrations of less than 2.0 mmol 1-l. 1.6. Analysis of Tissues 1.6.1. Soft tissues Imaging of elements can give important information on their distribution and the relationship to the tissue struc- ture. The suitability of LMMS for localization of toxic elements was discussed by Schmidt et al. (9213237 92/44 19); alterations of the tissue as a result of the localized presence of the toxic element could be easily seen. The absolute amount that could be detected by this technique was 1 x 10-19 g. Synchrotron radiation XRF can also be used for imaging. Van Langevelde and Vis (9212392) described the construction of the synchrotron microprobe at Daresbury UK capable of analysing at the ppm or sub- ppm level with a lateral resolution of 10 x 1 5 pm2.Compari- son with ion accelerators for the analysis of biological samples and RMs showed that the X-ray source gave better LODs for elements of high atomic mass and less damage to the sample. Applications of imaging by SRXRF were demonstrated by Nakai et al. (92/3273) for Cu Hg Se and Zn in human and animal tissues. Studies were made of rodents given organomercury compounds. Strong positive correlation of the Hg distribution with the distribution of the other elements suggested some interaction between Hg and the metalloenzyme system. The application of SIMS to imaging of metals in biological tissues was reviewed by Hallegot et al.(9211556). The effect of K deficiency on cardiac muscle was studied using X-ray microanalysis (92/2849). Samples of rat heart muscle were freeze-dried either in a vacuum or by a new technique using liquid propane as a cryodehydration medium. Both techniques were shown to give comparable results in retention of elements. A K concentration of 80 mmol 1-1 was found in the myocytes of rats under stress compared to 120 mmol 1-I in unstressed animals. Particle-induced X-ray emission spectrometry was applied by Tanaka et al. (9212042) to a study of Ca Fe K Rb and Zn in rats injected with Rb. Concentrations of Rb increased in blood liver and kidneys 7-8 d after injection but little change was seen for other elements. The possibility of using the peak-to-background ratio in PIXE and ion-microprobe analysis to quantify minor elements in thick biological specimens was examined by Koyama-Ito (92/1702).It was considered useful as a simple approximate method of quantification. The suitability of ZCP-MS for the multi-element analysis of tissue samples was demonstrated by Lyon et al. (92/2608). Accuracy was shown by analysis of NIST SRM Bovine Liver IAEA Kidney CRM and IAEA Animal Muscle CRM in which results on 23 out of 24 determina- tions agreed with the certified values. In addition real tissue samples taken at autopsy were analysed for Al Cd Cu Fe Mg Mn and Zn. Results compared well with those obtained by FAAS and ETAAS. A similar study by Schmit et al. (92/252 1) examined the accuracy of analysis of NIST SRM Bovine Liver by ICP-MS and assessed recovery from fish muscle tissue spiked with 11 elements.On living patients the soft tissue that is most likely to be sampled as part of a clinical diagnosis is liver as a needle biopsy. Although the samples are very small analysis can give valuable information on trace element disorders. Aadland et al. (92/2857) developed a solid sampling method to determine Cu by the cup-in-tube technique in ETAAS at the less sensitive 222.6 nm line. Addition of Pd-Mg(NO& as modifier delayed atomization making the appearance time of Cu in the biopsy samples aqueous standards and NIST SRM Bovine Liver similar. Calibra- tion with solid liver CRMs was found to be better than calibration with aqueous standards. Inductively-coupled plasma AES and ETAAS were applied by Baucells et al.(92/C690) to the determination of Cu Fe Mn Pb Se Ti and Xn in liver biopsies after digestion with HN03-HC104 using conventional or microwave heating. To determine Cu Mn and Zn in rat liver samples Luterotti et al. (92/C515 92/3843) developed a simple extraction technique in which the sample was homogenized with water and the elements extracted with HCl. Non-haem Fe in supernatant and coagulum fractions of liver was determined by Yokoi et al. (93/672) using ICP-AES with a Y internal standard. The analysis of needle biopsies from other tissues by XRF was described by Tvedt et al. (9212540). Samples were freeze dried before sectioning but evidence was found that some redistribution of the more mobile elements had occurred during the preparation time.The method was applied to the elemental analysis of prostatic and mammary epithelial cells. Buoso et al. (9212038) examined biopsies of colonic mucosa taken at endoscopy in patients with cancer of the colon and control subjects. Concentrations of trace elements especially Se and Zn were measured by NAA and PIXE. Cataractous human lenses were found by Giordano et al. (92/C4251) to have higher than normal Ca Cu and Zn concentrations and lower than normal K concentrations. Measurements were by FAAS and ETAAS after acid digestion. A procedure for determining Cr in the lens was developed by Pineau et al. (931674). The samples were digested with HN03-H2S04 in a mini-autoclave and Cr measured by ETAAS. Cataractous lenses had a mean Cr concentration of 0.205 pg g-' dry mass compared to 0.345 pg g-l in normal lenses.Alimonti et al. (92/C4245) described a study on trace element concentrations in human lungs from 13 non- smokers who formerly lived in Terni Italy. Fifteen ele- ments in five separate regions of the lung were determined by ICP-AES or ETAAS. Comparison with a previous study on former citizens of Rome showed statistically significant differences for B Co Cr Cu and Mg. The Hildebrand grid nebulizer was investigated by Hight and Rader (92/937) for the analysis of elements in H2S04 digests of rodent soft tissues by ICP-AES as a replacement for the conventional crossflow nebulizer which gave prob- lems with blockage. Nebulizer wash-out time was reduced by rinsing at high uptake rate with the solution to be analysed.Precision of determination ranged from 0.5 to 2.9% RSD. Taylor et a!. (92/4588a) described a method for quantify- ing pancreatic islets by staining with the Zn-binding fluorescent dye N-6-methoxyquinolyl-p-toluenesulfon- amide and then determining Zn after digestion by ETAAS. Vehicle exhaust fumes caused changes in essential element concentrations in a study of mice (92/3 160). Using EDXRF the highest concentration of Pb was found in the lungs of the mice but concentrations of Pb in the liver and kidney were also high. In all organs Fe concentrations increased whereas in liver Cu and Zn concentrations decreased. Supplementation of the diet of the mice with Fe or Zn resulted in less accumulation of Pb. Iron produced a more significant effect than Zn.The determination of total As in tissues by HGAAS requires attention to the decomposition stage to ensure complete breakdown of organoarsenic compounds. Sza- kova et al. (93/C906) compared dry ashing with Mg(N03)*-Mg0 wet digestion with HN03-H202-H2S04 and dry ashing in a commercial system with 02 O3 and NO,. The last gave blanks an order of magnitude lower than the first two methods. Wet digestion did not decompose completely the arsenobetaine in BCR Mussel Tissue CRM. 'The commercial system was the only system suitable for all CRMs studied.JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 115R Aluminium and Fe were determined in bone and soft tissues by Lian (93K319 93/535) using ETAAS with a rapid programme. No modifier or pyrolysis step was necessary.Samples were digested with HN03 for 3-4 h at 90 "C. When a new platform and graphite tube were used the tissue digests gave an enhanced signal for A1 but this interference disappeared as the platform and tube aged. Consistent results could be obtained by pre-treating the platform with a bone digest solution; aqueous standards could then be used for calibration. In order to determine boron in tissues of patients treated with complex B compounds for neutron capture therapy Tamat et al. (9214458) developed a method based on ICP- AES. Samples were digested with HC104-H202 for 1 h at 75 "C. Complete recovery of B in complex B cluster com- pounds was achieved. Germanium and tin concentrations in tissues were deter- mined by ETAAS in studies by Chiba et al.(93/741 93/749). To determine Ge (93/741) tissues were wet ashed taken to dryness and redissolved in 7 mol 1-l HCl from which the Ge was extracted into CC14. After back extraction into H20 the Ge was determined by ETAAS. The LOD was 0.05 ng and the recovery ranged from 78 to 104% depending on the organ. The method was applied to determine Ge in the organs of a patient who prior to death had ingested GeO for 1-2 years. The highest concentration of Ge was found in the spleen hair and nail. Use of hair and nail monitoring for Ge exposure was recommended. In the study on Sn (93/749) the highest Sn concentrations in human males was in the testes and appeared to increase with age whereas in females it was highest in the liver. The pattern was similar in mice but in dogs the Sn concentra- tion in the testes was very low and the highest concentration was in the liver.Lead and cadmium in tissues of farm animals were determined by Zima et al. (92/ 1655) using AAS. Particular attention was paid to a rapid digestion procedure. Samples were solubilized with concentrated HN03 at elevated temperatures and ethanol was added to prevent flocculation of lipids as the sample cooled. Results by this method agreed with those by more extensive wet digestion and by bomb digestion. A major study of Cd in the kidneys of the cattle population of South Australia demanded a simple and rapid method. Koh and Bansemer (921C1960) sub- sampled the kidneys with a titanium tube to take core samples from which the cortex and medulla were separated by use of a titanium knife.All subsequent operations drying at 80 "C dissolution in HN03 and dilution were carried out in the same glass tube prior to measurement by FAAS. The method allowed 100 samples to be processed in four days (8000 kidneys were analysed over 3 years). Calcium deficiency enhances Cd accumulation in the central nervous system according to Murphy et al. (92/4292). Even greater increases were seen in liver and kidney Cd concentrations. Measurements were by AAS with Zeeman-effect background correction. Determination of mercury in tissues presents special problems. In a study of factors in the determination of total Hg by CVAAS Scheuhammer and Bond (931671) found that with SnC12 as a reductant methylmercury was not reduced. To obtain complete Hg determination digestion with HN03-H2S04-HC1 was necessary. Liver homogenate then gave recoveries of greater than 85% when spiked with either inorganic Hg or methylmercury.Addition of L-cysteine resulted in depression of the Hg signal and its use with acidic reduction was not recommended. A method for determination of methylmercury was described by Lansens et al. (92K3603). The methylmercury was cleaved from the biological tissue with H2S04 and converted into the iodide form with iodoacetic acid. This volatile form was injected from the headspace into a GC and detected either by MIP- AES or by AFS. The AF detector gave 20 times the sensitivity of the MIP detector giving an LOD of 20 ng 1-' for a solution or 1 ng g-* in biological tissues when a mass of 50 mg of tissue were taken.Exposure of rats to methylmercury and inorganic mercury resulted in changes in the essential element concentrations in tissues according to a study by Muto et al. (9214289) using determination by ICP-AES. In the group exposed to HgC12 increases in Cu in the liver and kidney and Mn in the brain were found whereas in the group exposed to methylmercury chloride changes in Ca and Zn in the brain were observed. Recovery of Se from tissues in acid digestion for HGAAS improved by about 3-4% when a small volume of HCl was added to the digestion mixture (92/1769). This was shown by radiotracer experiments to prevent slight losses as the sample was taken to dryness. Hydride generation AAS was used in a study (93/745) on Se distribution in various tissues of rats and the effect of Se concentration in the diet.Highest Se concentration was found in the liver and lowest in the brain. Liver and kidney Se concentrations were positively correlated with dietary Se. Speciation of Se and Hg compounds in a dolphin liver by ultrafiltration and various chromatographic procedures was described by Matsumoto (92/3Q9 1). The elements were determined in the fractions by ETAAS with a Pd modifier. One of the compounds found was water soluble had amino groups and a molar Hg:Se ratio of 1. Extraction of Se with APDC into IBMK was used by Brown and Zeringue (92/2155) in the determination of Se in digests of biological tissues and foodstuffs by ETAAS. Thallium was determined directly in solid samples of bovine liver by laser-excited AFS in an electrothermal atomizer.The LOD was 100 fg and the calibration was linear up to 50 pg. In NIST SRM Bovine Liver the T1 concentration measured was 0.059 pg g-' with an RSD of 12.5%. The rare earth elements Dy Eu Y and Yb were determined in tissue samples by Nakamura et al. (9211 842). Comparison of AAS FAES and ICP-AES showed that the most sensitive and reliable technique was ICP-AES. Diges- tion with HN03 alone was preferable to digestion with H2S04-HN03 as precipitation of CaSO was avoided. Concentrations of uranium and thorium in soft tissues were measured by Igarashi et al. (92/4481) using ICP-MS. Results for normal levels were lower than others previously reported. They also reported determination of Th in the liver of a patient exposed to Th (92/4480). The liver was ashed and then treated with HN03-HC104.The residue was mixed with NH4HS04 as a flux and heated to 250 "C. The mixture was then dissolved in aqua regia-HN03 and Th determined by ICP-MS. The results agreed with those obtained by gamma spectrometry. 1.6.2. Brain To determine A1 in diflerent areas of brain Xu et al. (92/C3705) used ETAAS. Potassium dichromate was found to be an effective modifier to minimize phosphate interfer- ence giving results on a range of CRMs which were in good agreement with the certified values. The method was applied to the brains from patients with Alzheimer's disease and to control brains taken at post mortem. A more direct technique is imaging with SIMS. However Oakley et al. (92/2876) issued a note of caution about their studies on the distribution of A1 and Si in the brain.Commonly used substrates introduced artifacts into the ion image making it impossible to distinguish the true origin of the A1 and Si secondary ions. Preparation procedures for substrates free of this effect have therefore been investigated. Their results on the distribution of A1 in the brains of patients formerly on dialysis were reported (921232 1).116R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 The incorporation of A1 in brain was studied by Kobay- ashi et al. (92/1476) through the use of 26A1 as a tracer and measurements by accelerator MS. When 26A1 was injected into rats a considerable amount of 26Al was detected in the cerebrum 5-35 d after injection. Wang and Barnard (92/3834 93/C35) studied in vitro the complexes of A1 with neurotransmitters found in the brain.Speciation was carried out by SEC with identifica- tion by ICP-AES determination of A1 and P and UV spectrophotometry of chelates. Accumulation of methylmercury in the brains of young developing rats was studied by Braghiroli et al. (92/3161) using pressure digestion of the samples and determination by CVAAS. The exposure to methylmercury occurred in the pre-natal period. The Hg was distributed throughout all six brain areas examined but at different concentrations. By the 60th day of life methylmercury concentrations had fallen to almost those found in controls. 1.6.3. Bones and teeth The high inorganic content of bones and teeth (mainly Ca and P) causes problems in some techniques when determi- nation of trace elements is carried out.For analysis of teeth digests by ICP-AES Laznicka et al. (931C893) evaluated ion-exchange separation and solvent extraction of the Ca with quinolin-8-01. Hight and Rader (921937) found that the Hildebrand grid nebulizer could be used for direct analysis of bone digests provided there was extensive rinsing between samples to avoid clogging the torch injector tip and matrix-matched standards were used for calibra- tion. Direct analysis was also carried out by Jin et al. (92/1153) using ICP-AES. Seventeen elements were deter- mined on digests prepared with HN03 HF and HC104. X- ray fluorescence spectrometry has the advantages of mini- mal sample pre-treatment and element mapping which Bockman et al. (92/1823) demonstrated.They used an SR source to determine Cu Fe Sr and Zn and in addition to measure Ga a therapeutic agent claimed to inhibit Ca loss from bone. The Ga was shown to accumulate in the metabolically active region and to lead to changes in the Fe and Zn concentration. Lead accumulation in a population in northern Israel was assessed through measurement of Pb in root dentine of teeth by ETAAS (92/4274). Lead concentration was found to increase with age. The distribution of Pb in bone mapped by Jones et al. (92/4278) using SR-XRF varied with the bone structure. The Pb to Ca ratio was found to be non-uniform in the bulk material of the bone. Lead and Ba were measured by Huang et al. (92/1884) in archaelogical bones from Sweden using XRF. Lead concentrations in the 16 bones ranged up to 168 pg g-' whereas Ba concentra- tions were in the range 15-97 pg g-l.In a study of ancient bones from North American Indians Ericson et al. (92/4329) found levels of Cd about 50 times lower than those found today. The bones dating from about 1400 AD were analysed for Ag Cd Pb and Zn by ETAAS. Results indicated that the outer part of the bone had been contaminated with Cd Pb and Zn after death. Lead calcium ratios on uncontaminated bone were 8.4 -t 4.4 x signifi- cantly lower than those from modern adults in the UK and USA (210-35Ox lo-'). A rapid method for the determination of A1 and Fe in bone was developed by Lian (93lC319 931535). The pyrolysis step in the heating cycle could be omitted reducing the cycle time to less than 1 min.No modifier was necessary but it was important to condition the L'vov platform initially by repeatedly heating the tube with a bone digest solution. Bone samples were digested with HN03. Vanadium in the bone of patients on haemodialysis was determined by Romero et al. (93/C3 18) using ETAAS with a modifier of Pd HN03 and Triton X-100. Samples were digested with HN03 at high pressure. For patients on dialysis the mean bone V concentration was 2.9 1- 0.7 pg g-l compared with 1.4 -t 0.3 pg g-l for controls. Van Dieljen-Visser et al. (92/4337) found that the quantitative determination of bone marrow Fe could be of value in the diagnosis and investigation of disorders of Fe metabolism. Non-haem Fe determined by ETAAS on bone marrow aspirates correlated well with a cytological assess- ment.The between-batch RSD of the AA spectrometric method was 9.0%. Ferritin Fe also determined by ETAAS rose with increasing total Fe content until saturation of ferritin was reached at about 3 g of ferritin per kg of protein. Applications of LMMS in dental science were reviewed by IRechmann et al. (9212696). The technique was found to be especially useful in the investigation of metallic particles incorporated in the oral mucosa. Wataha et al. (92/2891) using FAAS studied the release of elements from ten dental casting alloys into cell culture media. Dissolution of Ag Cd Cu Ga Ni and Zn was seen but not of Au In and Pd. The dissolution was highly dependent on the type of alloy imaking the prediction of release behaviour complex. 1 h.4.Stones Using PIXE and nuclear reaction analysis Saint and Dyson (92/1825) were able to study the composition of urinary calculi using point by point analysis along a section of the stone. They discovered correlations between several pairs of elements. The technique allowed a picture to be built up of the variation in composition within the structure. A new iimaging technique described by Kaufman et al. (92/2 158) combined backscattered electron imaging to localize Ca and windowless EDXRF microanalysis to give compositional information. They were able to identify calcium salts in gallstones from 106 patients. Dissolution techniques nor- mally only give the total composition as for example in the study of Yuan and Zhang (92/1380) who measured Cu Mn and Zn by FAAS after digestion of the urinary calculi with HC10,-HCl.Inductively coupled plasma AES gives the advantage of simultaneous multi-element analysis as seen in the work of Koshinaga et al. (93/742) who measured 11 elements in gallstones. Black pigment stones contained ?more metals than calcium bilirubinate stones. Measure- iments of elements in bile fluid were also made to assess changes related to the stone formation. Black pigment stones were associated with increased secretion of Cu from the liver and increased concentrations of Ca Cu Mg P and Sr in the gall bladder. 1.6.5. Hair Very small samples of beard shavings (5 mg) were analysed by Kobayashi et al. (9214435) for Zn by FAAS using pulse nebulization of 80 pl of the digested sample. Using this technique samples taken from men every day for 10 d showed very little fluctuation in Zn concentration.The Zn Concentration in the head hair of neonates was similar to that of adults. The method was considered suitable for regular monitoring of the Zn status of patients on total parenteral nutrition. Wang et al. (92/C4 170) determined Zn in hair by XRF directly on a pellet of compressed pulverized hair. Dissolution of hair in 5% tetramethylammonium hydroxide for 1-1.5 h allowed Li et al. (92/2255) to determine Cu in hair by ETAAS. Sample digests were diluted with 0.2% v/v Triton X- 100 prior to measurement. Szilvassy-Vamos and co-workers (921C649 92/C425 5) applied their hollow cathode AE spectrographic method to the determination of Se in hair. Detection limits were lower when samples were digested with HN03 and liquid insertedJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 117R into the cathode than when powdered hair was analysed directly. Atomic fluorescence spectrometry gave Liang et al. (92/4675) an LOD of 1.5 pg 1-1 when HG was used. Samples were digested with HN03-HC104. Shen (9213938) digested hair samples similarly but determined Se by HGAAS. Inductively coupled plasma AES continues to prove itself as a suitable technique for multi-element hair analysis. Dong et al. (92/C654) determined 14 elements in hair in 1 00-fold diluted hair digests by both conventional nebuliza- tion and hydride generation. Another Chinese study (92/2720) recorded the analysis of 464 hair samples by ICP- AES and the effects of various washing treatments.No information on the value of these measurements was given in the abstracts. Some studies have shown changes in concentration of various elements in hair. Using XRF with conventional and SR excitation Wu et al. (921C4178) showed that for pregnant women hair Ca concentration decreased during pregnancy and increased after delivery Cl concentration increased during pregnancy but Al Br Cu Mg Pb and S showed no obvious change. The experiments were carried out by measuring the composition along the length of the hair relating the position to the time of deposition. Arumainayagam et al. (9214588b) measured by AAS the Cu Mg Pb and Zn concentrations in the hair of Malaysian children. A group with learning disabilities had significantly lower Mg and Zn concentrations than those with normal ability.Bozsai's study (921C4224) showed a correlation between hair arsenic concentrations and the concentration of As in well water in a region of Hungary where the natural water As concentration was between 50 and 200 pg 1 - I . The highest hair concentrations were found amongst 3-6 year old children. To achieve adequate sensitivity in the deter- mination of As in hair by ETAAS Halls (931C43) kept the volume of digest small. About 10 mg of hair were dissolved in 100 pl of HN03 the solution evaporated to dryness and the residue redissolved in 100 p1 of 1% v/v HN03. Palladium was used as modifier. In two recent studies hair Hg concentrations of people in coastal communities were studied. Cernichiari et al. (92/C873) studied mothers from the Faroe Islands.The higher Hg concentrations were shown to be related to regular pilot whale meat consumption. The median concen- tration of the whole group of 1052 samples was 4.5 pg g-l with 12.7Oh above 10 pg g-l. For some of the samples with the highest hair Hg speciation measurements showed a mean of 1 1% of the Hg as the inorganic form. The study of Bortoli et al. (9212980) showed that among fishermen and their families on the Italian North Adriatic coast Hg methylmercury and Se concentrations in the hair increased with increasing consumption of fish. Selenium was deter- mined by Zeeman-effect ETAAS and Hg by the same technique or CVAAS. Methylmercury was determined by GC with an electron capture detector. Using non-dispersive AFS Suo et al.(93/702) could measure Hg in hair and nails with LODs of 0.25 and 0.20 ng g-l respectively 1.7. Marine Biology One of the most important trace element determinations in fish (and the subject of most of the papers in this section) is Hg especially methylmercury. An important consideration is the stability of samples a problem studied by Horvat and Byrne (931704). Their preliminary findings showed that fresh and dried fish CRMs were stable with time and unaffected by alternate thawing and freezing (up to six cycles). Shellfish however showed some loss on thermal cycling. Losses of up to 30% methylmercury were found for mussels stored deep frozen. Gamma radiation showed losses for hake only; other species of fish and shellfish were unaffected. More detailed studies on this were promised.A further paper by Horvat (92/2908) detailed the determina- tion of methylmercury in fish CRMs. Various isolation techniques to separate organic Hg were tried and Hg was determined by CVAAS or by GC with an electron capture detector. The different approaches (ion exchange extrac- tion volatilization distillation) showed good agreement. The determination by GC allowed both methyl- and ethylmercury to be separately determined which was important for some CRMs with a measurable ethylmercury content. Lansens et al. (92/2909) used headspace GC with an MIP-AE spectrometer as a detector to determine methylmercury in fish. Within the headspace vial the methylmercury was cleaved from the tissue with H2S04 and converted into the iodide form by reaction with iodoacetic acid.Levels found in North Sea cod ranged from 0.13 to 0.63 pg g-' with a mean of 0.33 pg g-I whereas total Hg measured by CVAAS ranged from 0.19 to 0.90 pg g-l (mean = 0.40 pg g-l). Resende et al. (93/C105) converted methylmercury into the bromide to extract it into CHC13 for determination by CVAAS. The ingenious part of their method was to carry out the reduction in the organic phase by adding 50% HN03 in DMF and 2% NaBH in DMF. Inorganic Hg could be determined in the aqueous phase after the methylmercury was extracted. Total Hg deter- mined after acid digestion of the fish gave results in agreement with the sum of the inorganic and organic Hg. De Vargas and Romero (92/4103) studied total Hg concentrations in fish shrimps and mussels from Lake Maracaibo Venezuela.Samples were ground lyophilized and wet digested with a mixture of H2S04 HN03 HC104 KMn04 and H202 for about a week. Mercury was deter- mined by CVAAS using NaBH as a reducing agent. A further study from the same university (931C118) examined alternative ways of mineralization of fish for Hg determina- tion. It was shown that high pressure digestion with HN03-HC104 for 4 h at 125 "C using conventional heat- ing or with HN03-H2S04-H202 for 90 s using micro- wave heating gave excellent precision and a value for the NIST SRM Albacore Tuna of 1.10 f 0.0 1 pg g-' just outside the certified range (0.95 1- 0.10 pg g-l). According to Morita and Edmonds (92/C3572) trace elements in3sh ear bones otoliths are considered to reflect the living environment of the fish.They determined these elements by ICP-AES and ICP-MS after dissolution of the sample in HN03. Calibration was performed with standards matrix matched with an equivalent concentration of Ca. 1.8. Pharmaceuticals To discover whether the trace element composition of addictive drugs (cocaine and heroin) could be useful in identifying the source Violante et al. (92K4248 931479) analysed by ICP-AES a number of drugs confiscated by the Italian Police. Cocaines were digested in acid but heroins had to be dry-ashed before dissolution in acid. They concluded that their results supported the use of a trace element 'fingerprint' to identify the source of the drugs. Heitkemper et al. (921C3773) used the same principle to identify counterfeit pharmaceutical products.To achieve greater sensitivity the transition elements were collected on an on-line chelation column and then eluted with dilute HN03 for determination by ICP-AES. The problem of sensitivity in determination of trace elements in drugs at the ng g-' level was overcome by Niebergall and Wennrich (93/530) in their method for Penicillin G by making a very concentrated solution and introducing the solution with a V-groove nebulizer. Matrix- matched standards prepared from high-purity Penicillin G were used for calibration. Kushida et af. (931747) used both118R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 ETAAS and ICP-MS to determine 12 elements in 90 brands of drugs used for treating hypertension. The elements included the essential elements Ca Cr Cu Fe Mg Mn Si and Zn and the toxic elements Al Cd Pb and Ti.Drugs prepared from herbs or plants are in use in many parts of the world especially China and the question arises whether any of their beneficial action could be related to their mineral content. Ginseng was analysed by Sui and Wang (9212715) using ID-SSMS for 25 elements. Lin (921C493) analysed 100 samples of Taiwanese traditional medicines by AAS while Zhau et al. (9214665) used ICP- AES to determine elements in 26 Chinese drugs after wet digestion with HN03-HC104. X-ray fluorescence spectro- metry enabled Havranek et al. (921 1830) to measure Br Cu Fe Ni Pb Rb Sr and Zn in six medicinal plant drugs. Samples were simply ground and pressed into pellets. Solvent extraction procedures have been developed for particular applications.Lei et al. (9315 12) determined traces of the anaesthetics lidocaine dicaine and procaine in serum by extracting them as their ion-pair complexes with Zn(SCN)42- into 1,2-dichioroethane and then measur- ing the Zn by FAAS. A selective extraction for the determination of Mo in pharmaceuticals by FAAS was developed by Sanchez et al. (9212487). The element was extracted as its complex with 5,5’-methylenedisalicylo- hydroxamic acid into IBMK. A further reaction with thiocyanate and Snn transferred the Mo to a MoSCN- complex. The LOD 30 pg l-l does not seem to be adequate for the small concentrations of Mo likely to be found in pharmaceutical preparations. Malvankar et al. (9212588) extracted Cu and Zn from pharmaceuticals in salicylate solution into Aliquat 336 dissolved in toluene.The elements in the organic phase could be determined spectrophotome- trically by reaction with 1 -(2-pyridylazo)-2-naphthol or by stripping the metals into an aqueous phase for determination by FAAS. A between-laboratory comparison of various techniques (ASV ICP-MS FAAS and ETAAS) for the determination of Cd and Pb in calcium supplements was described by Bourgoin et al. (9212602). Included in the series of samples were laboratory grade CaCO and IAEA CRM Animal Bone. These workers concluded that the measurements of Cd and Pb by FAAS with Zeeman-effect background correction were not significantly different from the levels obtained using other techniques and because of the speed of the determination should be adopted by quality control laboratories.This is a surprising conclusion when one observes that the tabulated results show that FAAS gave a result for Pb in IAEA Animal Bone outside the certified range a high result for Pb in CaC03 powder and on calcium supplements results which agreed with the mean in only two out of three samples. The excellent agreement between the other three techniques is noteworthy. 1.9. Conclusions A notable feature of this year’s Update is the number of reports describing on-line sample preparation procedures which allow benefits to be gained from automation of the whole process normally in an FI system. On-line preconcentration allowed sensitivity enhancement in FAAS (92/C500 92/C4155) ETAAS (92/C473,93/C59) and ICP- AES (921C655 921C3773).Calibration by standard addi- tions could be made on-line with FI for ICP-MS allowing a fast throughput of samples (921 1243). Interferences in ICP- MS could be removed by simple pre-treatment on an on- line microcolumn (921C473 93/C59). Lastly there have been developments in on-line microwave-heated digestion of samples (92/C3 15 921947 9213838). Interesting though this latter development is the problem is that the samples need to be finely ground and made into a slurry to be sampled and to pass through the FI system. If the final analytical technique is AAS ICP-AES or ICP-MS why not analyse the slurry directly? The first developments have taken place in application of the 26A1 isotope to study the metabolism of A1 (921C621 92/ 1 140 92/ 1 14 1 921 1476 92/ 1494).Previously studies had used Ga as a marker for A1 and had assumed the behaviour would be similar. The availability of the 26A1 isotope should help to achieve a better understanding of the metabolism of A1 in humans and animals. Measurement so far requires the use of accelerator MS which will limit studies to just a few centres. Recent developments in multi-element techniques allow information to be obtained on a wide range of elements in a very short period of time. Consideration has therefore been given to the use of trace element profiles as a ‘Jingerprint’ for identifying the source of drugs of abuse (921C4248 93/749) and counterfeit pharmaceutical products (92/C3 7 73). Many of the methods featured in these Updates are over- complex but on paper they apear to be more scientific and perhaps require more space in their description.The use of advanced instrumentation also demands respect. The simpler methods tend to get lost amongst all this high technology yet in simplicity there also can be true genius. To determine Cd in kidney would you use ETAAS with a mixed modifier and Zeeman-effect background correction ICP-MS with prior separation of anions or ICP-AES and would you prepare samples by pressure digestion with microwave heating or use solid or slurry sampling? Could your system handle 100 raw samples in 4 days? Koh and Bansemer (921C1960) were faced with the problem of analysing 8000 kidneys from cattle over 3 years. They investigated sub-sampling of the kidney to obtain a smaller mass representative of the whole.The final procedure was to take a core sample with a titanium tube. The cortex samples were weighed into a 10 ml glass tube in which all subsequent operations were carried out. Samples were dried partially digested with HN03 diluted to 10 ml and the Cd determined by FAAS which is sufficiently sensitive for this determination. This is not high technology but a simple elegant and very cost-effective solution to a difficult problem. 2. ANALYSIS OF FOOD AND BEVERAGES Simon Branch and Helen M. Crews A summary of the published and conference papers covered in this review is given in Table 2. This year has seen a large number of publications from Spanish workers. There has been a decrease in the number of papers dealing specifically with A1 and V but there appears to be an upsurge of interest in Se.There are no separate sections on developments in FAAS or dietary intake studies this year. 2.1. Sampling and Sample Preparation 2. Direct determination of analytes Zinc in human milk samples was measured by ETAAS after the samples had been diluted ( 1 + 99) with 0.1 O/o Triton X- 100 (92/2620). An earlier publication by the same group (9211871) had reported that this direct method was theJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 119R Table 2 FOODS AND BEVERAGES Element Matrix A1 Drinking water Technique; atomization; analyte form* AA;ETA;L As Mussel oyster tissue AA;ETA;L As Beer AA;ETA;Sl As Foodstuffs AA;H y;L As Foods AA;Hy;L As Seafood As As As As As As Be Ca AA;Hy;L Drinking water AE;ICPL Mineral and curative waters AA;Hy;L Foods XRF-;S Vegetarian food supplements MS;ICP;L Club soda wine MSICP;L CRMs AE;ICP;L Milk AA;ETA;L Milk AA;FL Ca Cereals Ca CRMs Ca Foods Ca Flour Cd Mineral and tap waters AE;X-ray microprobe,S AE;ICP;Sl AA;F air-C,H,;L AA;FL AA;FL Sample treatmentlcomments Preconcentration was achieved using Chromazurol B on a PTFE membrane filter Two digestion procedures were compared one was based on dry mineralization the other on microwave-oven digestion in closed PTFE reactors.The former took 2-3 d per sample the latter 20 min Arsenic was determined by direct injection of slurries of sample ash. Zeeman-effect ETAAS was used to overcome the high sample background. The methodology had a characteristic mass of 35 pg As (30+ 1 + 5) reduced and determined separately using continuous HGAAS.The LODs were 3 ng g-' for As and 5 ng g-' for Se Samples were acid digested then Asm and AsV (the latter after reduction to Asm) were extracted into CHC13 back extracted into the aqueous phase and determined by HGAAS tetramethylarsonium cations were determined by HPLC-thermochemical HGAAS following MeOH extraction and a clean-up procedure. Recoveries of greater than 83% were reported Inorganic species were determined following on-line anion-exchange preconcentration. The procedure allowed determinations at the low ng ml-* level As Hg and Se were determined by HGAAS in an FI system. The LODs for As Hg and Se were 0.3 0.1 and 0.6 pg l-' respectively (in German) was found to correspond almost exclusively with seafood at a mean level of 2.1 pg g-' (dry mass) HPLC-ICP-MS was used to speciate As in kelp.N2 addition was used to minimize possible polyatomic interferences As was syeciated using coupled HPLC-ICP-MS. The use of an He-Ar plasma improved sensitivity but also led to increases in the ArCl+ interference Aqua regia-HC10 or HN03-HC104-HF in pressure bombs at 180 "C were used to effect total dissolution (in Chinese) Be in milk was preconcentrated with a liquid chelating exchanger prior to analysis by ETAAS. Highest levels (17.8 ng ml-1 ) were found in rural cows milk Sample treatment involved either wet ashing with HN03-H2S04 (2 + 1) or protein precipitation with TCA. Both approaches gave similar results (in Spanish) sections or powdered samples. The implication of the results for calibration strategies was discussed Ca Mg and Mn were determined in leaves by sieving to t 7 4 pm and suspending in HN03 solution followed by analysis using ICP-AES The effect of A1 and P OR Ca determinations was studied. Under certain conditions La and Sr were reported to eliminate the potential interference (in Japanese) assess the efficiency of mixing systems carbamate) resin; 5 ml of 8 moll 1-I HN03 were used as the eluent.No interference from other ions in the sample was reported. LODs were 0.03 and 0.34 pg 1-1 for Cd and Pb respectively Samples were digested in HN03-HC104-H2S04 Arsenobetaine arsenocholine and 525 foods were analysed for the presence of As. It Ca and K were determined in tissue embedded Statistical analysis of Ca and Fe results were used to Cd and Pb were preconcentrated on poly(dithio- Reference 931578 9214 12 921C49 1 921950 9212 5 2 7 9212 5 36 9212726 921C3362 921401 1 9214033 931C58 931409 931680 92/43 7 7 9211 8 14 921 1905 9212642 9213249 931C66 92194 1120R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 2 FOODS AND BEVERAGES-continued Element Matrix Cd Asparagus Technique; atomization; analyte form* AA;-;- Cd Beef kidney AA;F;L Cd Wheat flour AA;ETA;SI Cd Calcium supplements MS;ICP;- AA;F;- AA; ETA;- ASV;-;- AA;ETA;Sl Cd Mussel Cd Animal tissues Cd Cd Cd Cd c1 c o c u c u c u c u Diets Vegetables Beverages Vegetable foods Flours Feedstuffs biological tissues Edible oils Palm oil Liver paste Fish c u Edible oils cu Mussel c u Cocoa powder AA;ETA;L AA;ETA;L AA;FL AA;-;- AA;ETA;L AA;ETA;L WDXRF;-;S AA;ETA;L AA;FL AA;-;L AA;FL AA;-;- AA;F;L AA;ETA;Sl AA;F;Sl Sample treatment/comments Cd and Pb were determined in fresh and canned asparagus to estimate their contribution to daily intake of Cd and Pb in Spain Results of a survey of 8000 cattle kidneys from South Australia were reported.Emphasis was placed on sample preparation methods Platform ETAAS was used to measure Cd and Pb concentrations in wheat flour (in Chinese) Four different techniques were used to analyse Ca- rich matrices. Cd levels of 3.59 pg g-' were found in one brand of Ca supplement. Results for Cd and Pb were discussed in detail Platform ETAAS was used to measure Cd Cu and Pb levels in suspensions of mussel. For Cd and Pb NH4H2P04 was used as chemical modifier (in Chinese) ]For Cd and Pb tissue homogenate was dry ashed dissolved in HNO and analysed by ETAAS.For Hg the homogenate was refluxed for 12 h in a mixture of HN0,-H2S04 mixed with 30% H202 and analysed by CVAAS. The LODS were 1 pg kg-' for Cd and 10 pg kg-' for Hg and Pb Cd and Pb were determined in breathing zone air diet and faeces of Swedish female non-smokers. Faecal Cd and Pb concentrations were found to be good indicators of the level of ingestion carbon allowed preconcentration of Cd and Pb from vegetable digests Application of a low cost tungsten-coil atomizer to the determination of Cd Ni and Pb in beverages was described. LODs were 0.6 12 and 23 pg for Cd Ni and Pb respectively molecular species in plants was investigated (in German) C1 P and S were determined in commercial wheat barley maize rice field bean and soybean flours.Total analysis time per sample was t 2 0 min A chelation-extraction method using APDC and IBMK was described. The method allowed determination of Co and Se in the same sample FI-FAAS used to measure Cu and Fe in edible oils using an on-line standard additions method. Pre- treatment and dilution were not required By means of a 20 kHz ultrasonic probe Cu and Fe were extracted from palm oil into aqueous solution. Sample preparation time was less than 10 min Accurate analyses of Cu Fe and Mg were obtained following digestion of liver paste (500 mg) in a 750 W microwave oven. Digestion took 1 min levels in fish and fish lipid and protein content following a survey of Cu Se and Zn levels in fish from Lake Tanganyika Publication of the conference paper reported for Cu ref.92lC524 See Cd ref. 92121 14 Cu and Fe were determined by FI on-line microwave oven digestion FAAS. Prior to injection into the FI digestion system samples were slurried in 10% (Oxine and cupferron immobilized on activated The association of heavy metals with tissues and No correlation was found between trace element HNO Reference 921 1 776 921 1960 92/25 7 3 9212602 92/27 14 9214040 9214058 93lC 128 93lC 1 65 931447 9212066 9212 155 92lC424 921 1666 9211725 92/2070 9212609 92/27 14 9214636JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 121R Table 2 FOODS AND BEVERAGES-continued Element Matrix F Human diets F Tap water Fe Edible oils Fe Palm oil Fe Liver paste Fe Fruit juice wine Fe Fe Fe Fe Hg Technique; atomization; analyte form* AA;ETA;L Molecular absorption; ETA;L AA;FL AA;-;L AA;FL AA;F;L Canned foods AA;-;L Beer AA;FL Edible oils Cocoa powder Fish Seafood Crops AA;F;L AA;F;SI AA;CV;L AA;CV;L AA;CV;L Tea drinking water AA;CV;L Mineral and curative waters AA;CV;L Mussel offal AA;CV;L Tuna AA;CV;L Hg Fish Hg Cod muscle I Foods K Cereals La Foodstuffs water Mg Liver paste Mg CRMs Mn CRMs Mo Foodstuffs Na Foodstuffs AA;F;L AE;ICP;SI AE;ICP;SI AE;ICP;SI AA;-;L Reference 9212528 92lC524 9211 666 921 1 722 9212008 9212435 9212437 9212609 9214636 921408 92lC852 9212729 Sample treatmentlcomments molecular aluminium monofluoride following microdiffusion.The absorbent solution was AI3+ +SrZ+. Total F was determined by ETAAS following sample combustion in an oxygen flask.A platinum HCL was used to excite AIF molecules at 227.45 nm in a graphite furnace. An LOD of 100 pg was reported. Significant interferences from Na+ and C1-were observed Labile ionic F was determined indirectly as 92lC 3 76 5 See Cu ref. 92lC524 See Cu ref. 9211666 See Cu ref. 9211 722 HPLC was used to separate Fe species prior to detection by either FAAS or an electrochemical detector. LODs were 5 ng Fe for FAAS and 1 ng Fen for electrochemical detection following digestion in HN03 encountered in FAAS analysis of beer Fellr and Snlv were determined in canned foods FI overcame problems of burner head clogging often See Cu ref. 9212609 See Cu ref. 9214636 The drying and HN03 digestion of fish tissue using a microwave oven for the determination of Hg and Se were studied.The results were comparable to or better than traditional methods were analysed by CVAAS prepare samples prior to CVAAS. LOD was 195 pg ml-1 determination of Hg. LOD was 98 pg ml-1 (in Chinese) Organs and tissues from a variety of fish and shellfish Closed vessel microwave dissolution was used to An absorption cell was constructed for the See As ref. 921401 1 See Cd ref. 9214040 Digestion procedures based on either convection or microwave oven heating were reported. Sample dissolution without losses of Hg by volatilization or adsorption was possible. LOD was 53 ng 1-* AA;CV;L MS;ICP;L A study of Hg in Brazilian tinned fish was reported Evidence to support a theory that the Hg species in standards and digests influenced the performance of ICP-MS was reported enmeshed in a PTFE membrane was combined with oxidation to improve the LOD for I by ICP- AES.LODs for I- and 103- were 0.75 and 31 ng ml-l respectively AE;ICP;L Preconcentration by an anion-exchange resin AE;X-ray AA;ETA;L See Ca ref. 921 1905 The graphite tube was lined with tungsten foil giving concomitant improvement in sensitivity and reduction in memory effects. An LOD of 7.85 ng was reported See Cu ref. 921 1725 See Ca ref. 9212642 See Ca ref. 9212642 ETV-ICP-AES was used to determine Mo following fluorination with PTFE. At 202.030 nm an LOD of 0.7 ng ml-1 was possible Na content of a range of low-Na meals was measured. Whole portions were blended and then digested in a microwave oven microprobe;S 9213055 921401 1 9214040 93lC118 93lC 12 1 93x342 9212396 9211905 9213842 9211725 9212642 9212642 92/26 1 5 9212894122R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 Table 2 FOODS AND BEVERAGES-continued Technique; atomization; analyte form* Sample treatmentlcomments AA;F,air-C2H2; L IrJa was measured at 432.7 nm as part of an indirect Element Matrix Na Gourmet powder Reference 9214673 method of determining glutamic acid in gourmet powder. Recoveries were 92- 109% (in Chinese) 1% was extracted into IBMK (0.2%) and determined at 352.454 nm using ICP-AES. LOD was 0.5 ng ml-l chelation-extraction using the APDC-IBMK method. Ni found in the fats was presumed to have arisen from the catalysts used in fat hydrogenat ion 1% was measured by AAS following complexation with EDTA.EOD was 0.1 mg kg-I !See Cd ref. 931C165 Two indirect procedures were described for Ni was determined in a range of fats following determining phytic acid. One method involved separation of the phytic acid using ion-exchange chromatography the other involved separation by precipitation with FeC13. Good agreement with certified values was found for CRMs !Sample preparation involved injecting 50 pl of oil onto a filter-paper raised on four wax legs and allowing the paper to dry. P was then determined using XRF (in Chinese) See Cd ref. 921941 ,Pb was determined by ETAAS at 283.3 nm following in situ concentration of Pb hydride on a zirconium-coated graphite tube. The LOD was 242 Pg Pb contamination in canned pineapple was traced to welded and soldered joints in the cans.Canning led to concentrations 200 x higher than natural levels Pb was monitored in 32 common species of Spanish fish. Concentrations were in the range 15.8-303.3 ng g-I muscle See Cd ref. 9211776 Solder was identified as the major source of Pb in drinking water at an urban campus. Sediment also contributed to the Pb levels See Cd ref. 9212573 See Cd ref 9212602 Ni Cabbage liver Ni Edible fats AE;ICP;L AA;F;L 92/20 14 9213222 Ni Foods beverages AA;-;L 9214287 Ni Beverages P Cereals AA;ETA,L AE;ICPL 931C165 921C3383 P Vegetable oils XRF;-;S 9213946 Pb Pb Mineral and tap water Tap water AA,F;L AA,ETA;L 92/94 1 92/95 1 Pb Pineapple MS;-;E 9211288 Pb Fish AA;ETA;L 921 1708 Pb Pb Asparagus Drinking water 9211 776 9211821 Pb Pb Wheat flour Calcium supplements AA,ETA,Sl MSiICP- M,F;- M,ETA;- ASV,-;- AA;ETA;L 9212 5 73 9212602 Pb Plant tissue Two digestion techniques were evaluated HN03-N202-HF gave incomplete digestion but accurate results and H2S04-HN03-HC104 gave low results in some cases due to the formation of the mixed precipitate (Pb,Ba)SO,.These workers recommended that H2S04 never be used for the digestion of plant tissue if Pb is the intended analyte described. 24 ng ml-I of Pb could be determined in red and white wines Calcined sample was suspended in aqueous solution containing 0.1% vlv Triton X-100 and 0.1% mlv ammonium phosphate. The suspension was then analysed by platform ETAAS. A 0.4% suspension yielded a detection limit of 0.2 pg g-l The optimization of Pb hydride generation was See Cd ref. 9212714 Two preparation methods were outlined.The first involved direct aspiration of an oil-water emulsion the second involved chelation- extraction with EDTA. The LODs were 0.12 and 0.08 pg g-1 Migration of Pb from Pb crystal decanters was studied 9212603 Pb Pb Wine Paprika AA;Hy;L AA,ETA;Sl 9212605 9212682 Pb Pb Mussel Frying oils AA;ETA,S AE;DCP;L 92/27 14 92/2828 Pb Alcoholic beverages AA,ETA,L 9212842JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 123R Table 2 FOODS AND BEVERAGES-continued Pb Pb Pb Sb Se Se Se Se Se Se Se Se Se Alcoholic beverages Vegetables Beverages Drinking water AA;ETA;L AA;ETA;L AA;Hy;L AA;-;- Fish Foods total diets AA;Hy;L AA;ETA;L E a s Infant formula milk AA;Hy;L AA;ETA;L Biological tissues AA;Hy;L Fish Foods Foods Foods AA;-;- AA;ETA;L AA;Hy;L AA;ETA;L Technique; atomization; Element Matrix analyte form* Sample treatmentlcomments Pb Fruit and vegetables XRF-;S Pb and Sn concentrations were determined in 525 food samples.The highest levels correlated with canned foods andlor biological uptake Pb Muscle offal AA;ETA;L See Cd ref. 9214040 Pb Wine AA;ETA; L Wine samples were analysed straight from the bottle by platform Zeeman-effect ETAAS. NH3-H3P04 was used as chemical modifier (in German) AA;CV;L Pb Foods AA;ETA;L See Cd ref. 9214058 Pb Beer AA; ETA;L Pb levels in nine European beers were in the range 3- 14.8 pg L-I (in Spanish) Pb Beverages AA; ETA; L Pb was determined by direct ETAAS. NH4H2P04 was the chosen chemical modifier. The LOD was 0.82 ng ml-1 (in Chinese) digested with HN03 and Pb extracted with a combination of APDC DDC and IBMK (in Chinese) Pb Eggs AA;ETA;L A procedure based on HN03-H202 microwave digestion was described for measuring Pb in egg whites and yolks.Pb was determined at 283.3 nm using Zeeman-effect ETAAS with Mg(N03)2-NH4H2P04 as chemical modifier Pb Alcoholic beverages AA;-;L Samples were preconcentrated by evaporation The results of a survey were presented See Cd ref. 93lC 128 See Cd ref. 93lC165 Sample treatment and optimum operating conditions for determining Sb using a laboratory-made HG device were described. An LOD of 0.347 ng ml-L was attained See Hg ref. 921408 Samples were digested overnight in HN03 (1 6 mol l-l) diluted to 25 ml with water and analysed directly by Zeeman-effect ETAAS using 0.75% Ptw + 0.25% Mg(N03)2 as chemical modifier Four different wet digestion procedures for determining Se in eggs by HGAAS were presented Preliminary results of a dietary survey demonstrated that infants fed cows milk had significantly higher intake of Se than infants fed infant formula.This was reflected in plasma Se concentrations Modifications to the existing AOAC method for Se in biological tissues were described See Cu ref. 9212070 See Co ref. 9212 1 55 See As ref. 9212527 Se was determined by ETAAS after sequential dry ashing HN03 digestion and coprecipitation with Pd which also acted as chemical modifier. Absolute LODs were in the range 8-53 ng depending on the matrix Levels of Se in Finnish foods were found to have increased since 1984 when all multi-nutrient fertilizers began to be supplemented with sodium selenate.The major contributors in the diet were meat and cereals socioeconomic groups was surveyed using Zeeman-effect ETAAS. One group were found to receive less than the safe daily level Se in the diets of two different Turkish See As ref. 92lC3361 See As ref. 921401 1 Se in milk was speciated using stable isotope tracers A mixed Ba(N03)2-Mg(N03)2-Pd(N03)2 modifier overcame sulfate interference during the determination of Se in mineral waters. Several mechanisms for the interference and its subsequent attenuation were postulated Se Foods AA;ETA;L Se Foods AA;ETA;L Se Drinking water MS;ICP;L Se Mineral and curative waters AA;Hy;L Se Mineral waters AA;ETA;L . . -- Se Milk 7 3 Reference 9214032 9214040 9214045 9214058 9214263 9214502 921456 1 9214734 93lC44 93lC128 93lC165 9214430 921408 92lC566 92lC58 1 921 1768 921 1769 9212070 9212 155 9212527 9212663 9212725 9212889 92lC336 1 92/40 1 1 9214098 9214565124R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 2 FOODS AND BEVERAGES-continued Element Matrix se Foods Technique; atomization; analyte form* AA,ETA,L Se Chicken eggs AA;ETA;L Se CRMs AE;ICP;L Sn Marine foodstuffs AA;-;L Sn Fruit and vegetables Sn Fish Sn Foodstuffs Ti Plant materials V Foods V Waters V Foods Zn Human milk Zn Fish Zn Human milk Zn Biological materials Zn Foodstuffs Zn Vegetables Various ( 13) Biological CRMs Various (1 0) Canned foods Various Drinking water Various (6) CRMs Various ( 9 ) Animal tissue cattle feed milk XRF;-;S MS;ICP;L AA;Hy;L AA,ETA,SI AA;FL AA;ETA;S,L AA;FL AA;ETA;L AA;-;- AA;ETA;L AE;ICP;L MS;ICP;L MS;ICP;L Reference 92146 12 Sample treatmentlcomments A combination of 0.75% PtN and 0.25% Mg(N03)* as chemical modifier was found to allow interference-free determination of Se in foods and total diets A microwave preparation procedure for determining Se in egg whites and yolks was described (in Chinese) See As ref.931680 Organotins were extracted from enzymatically digested marine produce using either dithizone or tropolone. LODs for tetramethyl- and tetraethyltin were 0.8 and 0.7 ng g-I (as Sn) respectively See Pb ref. 9214032 Isotope dilution ICP-MS was used to determine trace Optimum conditions for the FI-HGAAS levels of Sn in a fish RM determination of Sn were described.The LOD was 0.08 pg 1 - I plant materials was described in detail. The procedure included a mild calcination to prevent damage to the pyrolytic cuvettes. For a 5% suspension the LOD was 0.03 pg g-I (2+ I ) pH adjusted mixed with oxine and activated carbon as an enrichment step separated re-digested in HN03 and analysed using FAAS preconcentration of Vv using activated carbon as the collector (in Japanese) A slurry ETAAS procedure for determining Ti in Samples were ashed then digested in HN03-HC104 92lC504 A method was described for the separation and 921 1 880 Publication of the conference presentation 92/C504 Three methods for determining Zn in human milk were described. A direct method using dilution ( 1 + 99) of milk in Triton X- 100 was found to be the most efficient (in French) 92146 15 9211871 9212070 9212620 See Cu ref.9212070 A method for determining Zn in human milk was described. The method yielded an LOD of 0.052 pmol I-' sample preparation were compared based on Zn recovery and residual C determined by ICP-AES. The analytical wavelengths were 193.09 1 and 2 13.856 nm for C and Zn respectively 70Zn:68Zn ratios were determined in blood urine and faeces from human pre-term babies using ICP-MS. The ratios were also determined in the babies food Dry ashing and wet dissolution procedures for milk 92lC3 3 5 7 AA;ETA;L Slee Cd ref. 931447 MS;ICP;L Two digestion procedures avoiding the use of H$04 were devised to allow analysis of five new CRMs. LODs for the elements were in the range 0.1-60 ng g-' canned fruit and pork elements in KMn04 intended for use in drinking AE;ICP;L AE;ICP;- Ten elements were determined in 24 varieties of A.number of techniques were used to determine toxic AA;ETA;- AA;Hy;- water treatment AA;F air-C,H,;SI Samples were charred above a Bunsen burner then ashed for 30 min in a 750 W microwave oven. After cooling the ash was slurried with HN03-H20 and aspirated into the flame (Ca Fe K Mg Mn zn) analytical scheme based on microwave oven digestion followed by analysis with ICP-MS (As Cd Co Cu Fe Mg Mn Pb Zn) The presentation described a rapid and simple 9214669 931680 9212492 9214032 9214703 931426 9214569 9213410 931447 92lC390 92lC492 92lC530 921082 92lC709JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 125R Table 2 FOODS AND BEVERAGES-continued Element Matrix Technique; atomization; analyte form* Various (9) Biological tissues foodware AE;ICP;L Various CRMs Various (1 8) CRMs Various Milk powder Various (5) Shellfish Various (4) Peas Various (24) Human milk Various (7) Wine Various (4) Mushrooms Various (33) Biological tissues Various Nuts orange juice Various (4) Wines Various Citrus juices Various (10) Foodstuffs Various ( 10) Grapefruit juice Various (1 5) Orange juice Various (7) Waters AE;ICP;L MS;ICP;L NAAi-i- XRF;-;S AA;F;L AA;-;- AA;-;L AE;ICP;L Colorimetry; Electrochemistry; NAA;-;L -;L -;L AE;ICP;L AA;-;- MS;ICP;L AE;ICP;L AA;-;L AA;-;L AE;F;L AE;ICP;L XRF;-;S AE;ICP;L AA;F;L AE;ICP;L AA;ETA;L Sample treatmentlcomments The Hildebrand grid nebulizer (HGN) was used in conjunction with ICP-AES to measure elemental concentrations in digests of biological tissues and in solutions leached from foodware using acetic acid.The HGN performed well if operating parameters were optimized for each solution. Strategies to overcome specific problems were outlined (Ca Cu Fe K Mg Mn Na P Zn) The characteristics and problems of a prototype stopped-flow microwave oven wet digestion system were described. Precise and often quantitative results were obtained using a digestion time of 2 min MS for analysing biological materials were reviewed Samples were analysed as pressed pellets and irradiated for 1000 s. The fundamental parameters method was used to determine results which in most cases yielded LODs of approximately 1 p g g-' Microwave digestion was compared with conventional wet and dry ashing methods.Lower recoveries were observed for dry ashing (Cd Cr Cu Pb Zn) Changes in the mineral content of peas at four levels of maturity during commercial canning procedures were investigated (Cu Fe Mg Zn) milk in six different countries were reported. The findings pointed to a need to reassess the dietary requirements of young infants for a range of minor and trace elements The advantages and disadvantages of NAA and ICP- The results of an exhaustive study of human whole Reference 921937 921947 9211501 921 1726 9211 765 921 1774 921 I824 921207 1 921252 1 92/26 18 9212645 1 + 3 dilution of wine with water allowed the rapid determination of seven elements using an ICP- AES fitted with a Babington-type nebulizer (B Ca Cu Fe K Na Zn) Accumulation of heavy metals in the vicinity of a lead smelter was found to vary with species of mushroom (Cd Cu Hg Pb) Quasi-simultaneous determination of many of the elements present in biological tissues was reported Multivariate statistical analysis of elemental data was used to identify the geographical origin of a number of foodstuffs dilutions was used for wine analysis (Ca K Mg Na) grapefruit juice was investigated 190 fruit grain and vegetable products by multi-element XRF (Ca C1 Cu Fe K Mg Mn p s Zn) 92lC 1 946 FI equipped with a dialysis unit for large on-line The chelation of minerals by pectin in orange and The concentration of ten elements was determined in The leaching of minerals from ceramic ware into acetic acid and grapefruit juice was investigated (Al B Ca Cd Ce Co Mg Na Pb Zn,) (in Japanese) statistical analysis using a neural network of the elemental composition ETAAS was coupled to a continuous flow hydride generator equipped with a preconcentration column.LODs were in the lower ng 1-l range (As Bi Cd Cr Pb Sb Se) Country of origin of orange juices was identified by 92lC3307 92lC3664 9212 72 7 921284 1 9213248126R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 Table 2 FOODS AND BEVERAGES-continued Element Various Various (4) Various Various (8) Various Various Various ( 12) Various (9) Various Various (66) Various (6) Various(6) Various (5) Various (4) Various Various (6) Various (6) Matrix Potable water Milk powder Proteins Water Mussel Vegetables Mushrooms Milk powder Clinical and biological Food contact packaging samples foods Biological materials foodstuffs Drinking water Tap water Drinking water Cereals tea leaves Tea leaves Vegetables Technique; atomization; analyte form* MS;ICP;L AA;ETA;L MS;ICP;L AA;F air-C,H,;L XRF-;S AEi-i- AA;-;- AE;d.c.arc;- AE;F;- AA;F;- . . -- 9 . . -- 9 MS;ICP;L MS;ICP;L AE;FL AA;F;L AA;ETA;L AA;-;L AA;ETA;L AE;ICP;S AE; I C P; L AA;F air-C2H2 s1 AE;F;Sl Sample treatmentlcomments A method to characterize water by principal The results of a study of seven methods of milk component analysis of ICP-MS data was described powder digestion were reported (Cd Cu Pb Zn) (in Chinese) Coupled SEC-ICP-MS was used to separate and isolate labelled protein species in chicken meat On-line preconcentration was achieved using a chelating resin (Cd Co Cr Cu Mn Ni Pb Zn) A multi-element procedure was developed that used geochemical standards diluted in cellulose as calibration standards vegetables were monitored bioaccumulation by mushrooms was studied Metal contents of pesticides and pesticide-treated Mineral migration from soil and subsequent Raw and commercial milk were differentiated on the basis of principal component analysis of the elemental components of the two milk types (Cd Cr Cu Fe Mn Mo Ni Pb Zn) The 199 1 - 1992 ASU review of clinical biological and food sample analysis Semi-quantitative analysis of ten materials intended for food packaging was performed by ICP-MS Interfering anions such as Po43- S042- and C1- were removed on line from sample digests using a 2 x 0.2 cm column packed with an iminodiacetate chelating resin (Cd Cu Mn Pb V Zn) Amongst a number of metals assayed in Venezuelan tap water Al Fe and I( were found to exceed USA and Venezuelan upper limits for drinking water (Al Ca Fe Mg K Na) Preconcentration factors of 1 5-24-fold were achieved using on line FI with a weak acid resin (Cd Cr Cu Fe Mn) following coupling FI with HG to ETAAS (As Bi Sb Se) induction coil to allow powdered sample introduction (in Chinese) Samples were ashed at 500 "C digested with HC1 and H,02 and rare earths extracted using a solution containing benzene and l-phenyl-3-methyl-4- benzoyl-5-pyrazolone and pentan-2-01 (in Chinese) furnace for 45 min then slurried in HN03 (Ca Fe LODs were improved by an order of magnitude Two enclosed electrodes were fitted above the Samples were dry ashed in a microwave mume K Mg Mn Zn) Reference 92lC3757 9213940 9214 104 92lC4 162 9 2 x 4 179 92lC4236 92lC4243 9214338 9214562 93lC54 93lC59 93lC 129 93/C 136 93lC 1 52 931675 931701 931770 *Hy indicates hydride and S L G and SI signify solid liquid gaseous or slurry sample introduction respectively. Other abbreviations are listed elsewhere.more efficient method when compared with wet ashing with HNOJ prior to dilution. The accuracy of this direct method was ascertained using standard additions and NIST SRM 1549 Non-Fat Milk Powder. The LOD was found to be 0.052 pmol 1-l. Normal values for colostrum and transitional milk varied from 45 to 3 18 and from 30 to 146 pmol l-l respectively. European beers were analysed directly for Pb using ETAAS (92/4263). The sensitivity of the method was 0.67 pg 1-' and the detection limit was 0.7 pg 1-l.The recovery of added Pb was Ioo.7°/o. The Pb concentrations were below the legal maximum with values ranging from 3.0 to 14.8 pg I-'. Iron in beer (92/2437) was measured directly using FI with FAAS. This procedure minimized clogging of the burner head with proteins and dissolved solids from the beer. Lead in frying oils (92/2828) was determined by aspirat- ing an oil-water emulsion directly into the plasma of a DCP-AE spectrometer. A second method involved extrac- tion of Pb into an aqueous EDTA phase prior to measure- ment. The LOD for the emulsion method was 0.12 and for the extraction method 0.08 pug g-!. The presence of heavy metals in edible oils has a negative effect on the oxidative stability of the oils.Carbonell et al. (92/2609) developed a direct method for determining Cu and Fe in edible oils using unrefined oil samples and FI with standard additions. Measurement was by FAAS. A sample preparation time ofJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 127R less than 10 min was achieved by Saleh et al. 92/1666 using an ultrasonic extraction procedure for the determina- tion of Cu and Fe in palm oil. The acidic aqueous phase was separated from the organic phase after ultrasonic agitation by filtering through filter-paper. The metals in the aqueous phase were measured by FAAS. Recoveries of approxi- mately 98% were obtained for added (4 ppm) Cu and Fe.When compared with an American Oil Chemists Society (AOCS) standard dry ashing method the ultrasonic tech- nique gave RSDs of less than 5% compared with up to 37% for the ashing method. Direct analysis of red and white wines was not possible by ICP-AES unless the wines were diluted 4-fold with water (92/C1946). Direct aspiration of the wines resulted in extinction of the plasma under the operating conditions used in this work. Data for B Ca Cu Fe K Na and Zn were obtained with lowest concentrations found for Cu in both red and white wine 0.04-0.16 mg l-l and highest values for K in red wine 950-1 5 15 mg 1-l. 2.1.2. Preconcentration Cadmium and Pb have been measured in mineral and tap waters by FAAS after preconcentration using a poly(dithi0- carbamate) resin (92/941). Results were not reported for saline waters.Detection limits were 0.03 and 0.34 pg 1-l for Cd and Pb respectively. Bhattacharyya et al. (9214377) reported the use of a liquid chelating exchanger for preconcentration of Be from a variety of milk samples prior to measurement by ETAAS. Buffalo cow human and spray-dried milk samples were analysed. Beryllium concen- trations ranged from 4.04 ppb in human milk to 22.87 ppb in rural buffalo milk. On-line ion exchange and preconcentration were used to determine Sn in canned foods (93/429). Measurement was by HGAAS. In order to modify the sample matrix and to achieve optimized and reproducible conditions for hydride generation the analyte was first converted into the chloros- tannate complex which was separated and concentrated on a strongly basic anion exchanger.The analyte was eluted with HNO,. The procedure resulted in an enrichment factor of 3.5 with an LOD of 0.08 pg 1-l at a sampling frequency of 72 per hour. Potential interferents such as Ni Co and Zn could at a Sn level of 10 pg l-* be tolerated at an excess of 1000 x without impairing the assay while a 100- to 1000- fold excess of CulI decreased the signal by 10-1 5%. Three conference presentations discussed on-line precon- centration for water samples. Manabe (92/C3362) deter- mined As and Se using ICP-AES after preconcentration with an anion-exchange system. Flame AAS was used to measure Cd Co Cr Cu Mn Ni Pb and Zn following concentration on a resin (92/C4162) and Cd Crw Cu FelI1 and MnlI after on-line preconcentration with a weak-acid resin (931C136).2.1.3. Digestion Lead in plant tissues was measured by ETAAS after digestion with either HN03-HC104-H2S04 or HN03- H20,-HF(92/2603). The latter mixture although leading to incomplete digestion gave values for the 13 tissues studied that were in good agreement with certified or indicative values. The former acid mixture which had proved successful for determining Cd in these samples produced Pb results that were too low for some matrices because of the formation of a mixed precipitate (Pb,Ba)S04. Barbera et al. (92/4267) determined Cd and Pb in vegetables by FAAS after digestion with HN03 and chelation and extraction with APDC and IBMK. Cobalt and Se were measured in feedstuffs and biological tissues after chelation with EDTA and extraction into IBMK (92/2155).Both analytes were determined in the same extract by ETAAS but Co was measured first as the chemical modifier used in the Se measurements interfered with the determination of Co. Trace levels of REE (Ce Dy Eu La Sm and Y) were simultaneously determined by ICP- AES in organic extracts of tea leaves (93/701). The samples were ashed and digested with HCl and H202 then extracted with a solution containing C6H6-PMBP ( 1 -phenyl-3-me- thyl-4-benzoyl-5-pyrazolone) and pentan-2-01. A combina- tion of tetramethylammonium hydroxide (TMAH) and EDTA was used to leach the major and minor constituents from botanical samples prior to determination by ICP-AES (931436). Most of the results were in agreement with certified or reported values for some CRMs of botanical origin except for low recoveries of A1 and Fe.The interference caused by A1 and P on the determina- tion of Ca in food samples by FAAS was overcome by addition of 1.0% La or 0.3-0.6% Sr (92/3249). This treatment was applied to the analysis of mushrooms peanut shells tea leaves eggplant and leaves and bulbs of water hyacinth. In a presentation at the 1992 Winter Conference on Plasma Spectrochemistry Krushevska et al. (92/C3357) reported the results of a comparison of sample decomposi- tion procedures for the determination of Zn in biological samples by ICP-AES. The comparison of procedures for the decomposition of skimmed formula and breast milks was based on Zn recoveries and residual C after digestion. Both dry ashing and wet ashing (including high pressure bombs and three microwave heated systems) procedures were investigated.Whilst Zn recoveries ranged from 96 to 1 OO% the amount of residual C varied with the type of digestion used the type of apparatus and the conditions employed for a particular procedure. For example the destruction of organic matter can be improved by addition of H2S04 and H202 and by increasing the pressure of the digestion. It would be very interesting to see the full data set published. The number of publications reporting the use of rni- crowave digestion procedures for food samples has increased. The determination of Hg by CVAAS and Se by HGAAS after drying and digesting fish tissue using a microwave system was compared with determinations made after freeze drying the tissue and open vessel digestion (92/408). The microwave digestion system using concentrated HNO was reported to be more efficient than the open system.There was no significant difference in the two drying methods as judged by the values for the water content of the fish tissue and the measured Hg and Se concentrations (consistent with a 95% confidence level). Navarro et al. used microwave dissolution prior to the measurement of Hg in fish from the Spanish Mediterranean coast by CVAAS (931437). Results from the analysis of a CRM agreed with certified values. The LOD was 0.195 ng ml-* and Hg concentrations in the fish samples ranged from 0.033 to 1.21 1 pg 1-l. The same group has measured Hg (by CVAAS) in fruit and vegetable crops following microwave dissolution (92/2729).Results for 5 1 crops ranged from 0.005 to 0.21 5 pg g-I of Hg. Another group of Spanish workers (92/C4 12) compared dry mineralization of canned mussel products with mi- crowave oven digestion of these samples for As analysis. Moisture contents were determined either by drying in a conventional oven for 24 h or in a microwave oven for 8 min. Differences between the two methods were of the order of 20.7%. Arsenic was measured by graphite plat- form in furnace Zeeman-effect AAS. Whilst the LOD precision and accuracy were similar for the two methods microwave digestion with HNO and H202 reduced sample treatment time from 2-3 d using dry mineralization to 20 min. The results of wet ashing in a microwave oven were128R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 compared with data from dry ashing in a muffle furnace (92/1775). Samples of citrus juices or synthetic multi- element mixtures were digested by both procedures and the diluted digests analysed by ICP-AES. For the multi-element mixture results from both procedures differed by less than 10% from the results for an undigested but diluted solution. For grapefruit juices there were differences of less than 10% between the two methods. Orange juice samples showed greater losses for Na (16%) Si (1 3%) and Sn ( 1 1%) with the dry ashing technique. Oles and Graham (92/2068) compared a mixed acid hot-plate digestion with a mixed acid microwave heating method. The microwave technique gave clear digests within 30-45 min compared with 8-12 h for the hot- plate digestion.The digests were measured by FAAS for Ca Cu Fe K Mg Mn Na and Zn. Precision for the microwave digests was equal to or better than for the hot-plate digests. Recoveries of added analytes from several food matrices gave no indication of effects resulting from incomplete digestion of the samples. It might be argued that an aqueous spike added prior to digestion is not the best way of ascertaining if all of the endogenous analyte has been released. However Oles and Graham reported that clear digests were obtained and that values for NIST SRMs compared favourably with the certified values. In addition to the above publications microwave dissolu- tion of samples has been described for the determination of Pb by ETAAS in fish (92/1708) and egg white and egg yolk (92/4734).Flame AAS has been used after microwave dissolution of samples to determine Cu Fe and Mg in liver paste samples (9211 725); Cd Cr Cu Pb and Zn in shellfish (9211765); Na in frozen dinners (92/2894) and Cu Fe and Zn in mussels (93/801). Microwave digestion has also been used with slurries of samples. Development in this area are described in the next section. 2.1.4. Slurry sampling A prototype system for stopped-flow microwave assisted digestions has been developed by Karanassios et al. (92/947). The system consists of a peristaltic pump two high-pressure valves a commercially available microwave oven that contains a coiled perfluorinated alkoxy-PTFE digestion tube assembly a pressure gauge and a tempera- ture transducer. The power to the oven is adjustable over nine steps from a low setting (approximately 72 W) to a high or full power setting (approximately 720 W).A sample plug consisting of a water slurry of a powdered botanical or biological reference sample in an acid mixture was pumped into the coil. Sample flow was stopped the coiled tube sealed by valves and the microwave power applied for 2 min to digest the sample. Samples were then collected and measured by ICP-AES. In this preliminary study elemental recoveries were sample-type and digestion-time dependent. Precise and in many cases quantitative digestions were achieved using a net digestion time of 2 rnin. Gluodenis and Tyson (92/4636) have published the first of a proposed series of papers on the potential ofFIsystems for directly coupling on-line digestions with A S .They report the analysis of a slurry of cocoa powder in 10% HN03. The slurry was injected into a double FI manifold incorporating a resistively heated oven and digested under stopped-flow high-pressure conditions. Gas-liquid separa- tion was effected by a two-stage de-pressurization system. Copper and Fe were measured by FI-FAAS. The cocoa powder was also digested using a closed vessel microwave system and an open-vessel hot-plate method. These digests were also measured by FAAS. The results for the stopped- flow slurry determinations for Cu and Fe were 44 * 19 and 144k 10 mg kg-l respectively. These figures were com- pared to the values for Cu and Fe for the microwave digests 5022 and 1 8 0 ~ 10 mg kg-l; and the values for the hot-plate method 52A2 and 180k mg kg-l respectively.The large uncertainty on the Cu figure for the slurried samples was thought to be due to the greater dilution employed for this sample bringing it close to the LOD for FAAS. The value for Fe for the slurried sample was the same as that for the other two methods when calculated using standard additions and was probably low because of incomplete digestion. The proposed procedure produced clear samples and increased sample throughput whilst decreasing sample and reagent consumption and reducing contamination. Arsenic was determined in beer samples at ng g-l levels following dry ashing of the samples and then suspension of the ash in FINO3 (92/950). The resultant slurry was measured by ETAAS with Zeeman-effect correction after direct injection of the slurry onto a L'vov platform.The As was atomized under STPF conditions with the addition of a nickel-ascorbic acid chemical modifier. The technique enhanced sensitivity by a factor of 2.5 giving an RSD of 4.5% for six independent analyses of a beer sample containing 8.5 ng g-l of As. Results for beer samples were comparable to those obtained by HGAAS. Vegetable samples were also subject to dry ashing in a microwave muMe furnace prior to analysis by FAAS and FAES (93/770). The ashes were suspended in HN03 and the slurry either introduced directly into an air-C2H2 flame for Fe Mn and Zn determinations or injected into a double channel FI manifold for the determination of Ca K and Mg. Results for CRMs were in agreement with certified values. Carrion et al.(9212642) reported analysis of plant tissue following nebulization of a suspension of powdered sample using a V-groove nebulizer for measurement by ICP-AES. The samples were also subject to a wet ashing procedure and the results compared with those from the slurry analyses. There was good agreement between the two methods. Ground fruit was suspended in Triton X-100 solution and the slurries measured by FI-FAAS by Burguera et al. (93/483). Relative standard deviations of 1 .O-2.0% were obtained for the measurement of Ca K Mg and Na in tropical fruits. Three NIST SRMs were dispersed in 1% Triton X- 100 by grinding with a planetary micronizing mill (92/1276). The resulting slurries were analysed by ICP-MS without any further treatment.The LOD precision and accuracy were determined for three NIST SRMs Bovine - . Liver Rice Flour and Pine Needles. The LODs ranged from 0.0001 pg g-* for U to 0.52 pg g-l for Zn. Acceptable accuracy and precision were obtained for most of the certified elements in NIST SRMs Bovine Liver and Rice Flour even for volatile elements such as As Br and Se. Relatively poor accuracy was obtained for Pine Needles. Two papers describe the use of slurries to analyse plant materials by ETAAS. Lead in commercial paprika samples (92/2682) and Ti in paprika lettuce spinach and pea samples (9214569) were determined after ashing at 350 "C then suspending the ash in 0.1 Yo v/v Triton X-1 00 and 0.1 % m/v ammonium phosphate for Pb determinations and in water containing 0.03% hexametaphosphate for Ti determi- nations. In both cases calibration was with aqueous stan- dards.The results for Pb agreed with those obtained by dry ashing and dissolution in acid. It was noted that particle size has a considerable effect on the procedure with the chemical modifier for Pb analyses being less effective on larger particles. Data obtained for Ti were in good agree- ment with those obtained by an acid dissolution procedure. Similarly good agreement was found for Cd Cu and Pb ETAAS results from solid sampling of mussel standards when compared with data from acid digestion of these samples (92/27 14).JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 129R 2.2. Developments in Hydride Generation Techniques A HGAAS method was developed for monitoring As in seafood products (931440). Arsenic was determined in mussel products using HGAAS STPF Zeeman-effect AAS and ICP-AES.Whilst ICP-AES was found to be the most convenient technique it was not suitable for samples with As levels below 0.1 mg g-l. For such samples the HGAAS method was chosen with an LOD of 0.017 ,ug g-* and an RSD of 3%. Alvarez and Capar (92/2527) described a continuous HGAAS method for As and Se in foods. Food samples were mineralized by boiling in a mixture of HN03-HC104- H2S04 (30+ 1 + 5); Sew was reduced by adding H20 and HCl. Solutions were diluted and Se was determined in one portion. The remaining solution was used for the determi- nation of As. Potassium iodide was added to reduce AsV to A P the solution allowed to stand for at least 10 min and then the As measured.The reductant used to generate the hydrides was NaBH (4%) in KOH (0.5%). The LODs were 5 ng g-l of food for Se and 3 ng g-l for As. Arsenic and Se were determined (93/680) in mussel and shrimp SRMs by HG with ICP-AES. Samples were digested with either aqua regia-HC10 or HN03-HC104-HF in pressure bombs which were heated overnight at 180 "C for 3 h. Results agreed with the recommended values for the SRMs. Antimony in drinking waters was measured following reduction of Sbv to StJrr with KI-ascorbic acid (9214430). The hydride was generated by NaBH in a laboratory-built device and then atomized in a flame-heated silica tube. The LOD was 0.347 ng ml-l with RSDs of 4.08% for the instrument and 7.74% for the overall method.Accuracy was determined by recovery assays and showed the method to be useful for determining Sb at levels normally present in drinking water. Two publications report the determination of Pb by HG. Cacho et a1.(92/2605) reported the determination of Pb in both red and white wines. The influence of some character- istic wine components; CH3CH20H tartaric acid and SOz on the efficiency of Pb HG were investigated. Changing from an aqueous to an ethanolic medium decreased efficiency markedly but above a concentration of 5% CH3CH20H the efficiency varied very little. Tartaric acid affected the Pb HG efficiency to a lesser extent than CH3CH20H whilst SO2 at concentrations normally found in wine had no effect. Optimum signal was obtained by increasing the NaBH concentration from 7% (for aqueous samples) to 2 1 Yo for wine samples.The LOD for Pb was 24 ng g-l in the wines. A 6-fold enhancement in sensitivity was achieved by the in situ concentration of PbH2 on a zironium-coated graphite tube compared with the use of a pyrolitic graphite coated tube (92/95 1). A laboratory-built hydride generator was used. Hydride generation was ac- complished in a continuous mode in a mixing cell by using two channels of a peristaltic pump to deliver the sample and NaBH4 solutions. Silicone rubber tubing was used to connect the outlet of the hydride generator to a quartz tube. The tip of the quartz tube was inserted into the sample introduction port of the graphite tube and held in contact with the opposite interior wall. The hydride generated was stripped from the solution by an Ar gas stream and was absorbed on the inside wall of the zirconium coated graphite tube.Lead measurement was by ETAAS. The absolute LOD was 242 pg. The RSD for ten measurements of 3 ng of Pb was 2%. The method was applied successfully to the measurement of Pb in some RMs and a tap water sample. In a conference presentation (93/C152) the use of FI coupled to HGAAS to improve detection limits was reported. A commercially available graphite furnace auto- sampler was coupled directly to an FI system to distribute generated hydrides for trapping onto a pre-heated graphite surface. The efficiency of trapping and atomization was almost identical for coated and uncoated tubes if small sample volumes were taken. If larger volumes of several millilitres were used the trapping efficiency of the different surfaces was found to depend strongly on sample volumes but not on the analyte concentration in the sample.Recoveries of close to 100% were found and depending upon the sample volume the relative LODs could be lowered by about an order of magnitude. Results for As Bi Sb and Se in drinking waters were in good agreement with expected values. 2.3. Speciation Studies Extraction methods originally developed for alkyllead determination were used to efficiently extract methyl- and tetraalkytin compounds from marine food products with no or few modifications (92/2492). Alkyltins were complexed with with either diphenylthiocarbazone or tropolone from enzymatically hydrolysed samples. Tetraalkytins were ex- tracted with hexane.Butyl or methyl derivatives of the alkytins were made by Grignard reaction for analysis by GC-AAS. Recovered butyltin levels in contaminated foods increased after enzyme hydrolysis. Many of the consumer marine food items examined contained ng g-l levels of butyltin compounds. The predominance of tributyltin indicated contamination of the marine food supply by commercial usage of the compound in antifouling paint formulations. No tetraalkyltin compounds were detected. The LODs for tetramethyltin and tetraethyltin were 0.8 and 0.7 ng g-l (as Sn) respectively. Arsenobetaine arsenocholine and tetramethylarsonium cations were determined in seafoods and human urine by HPLC-thermochemical HGAAS (9212726). Arsonium compounds were detected in edible marine tissues (lobster tail muscle peeled and de-veined shrimp cod fillet and cod- liver oil) after homogenized tissue (5- 10 g) or an equivalent mass of freeze-dried powder was extracted with CH30H and the extracts combined and flash evaporated. For human urine analysis 5 mi of urine were diluted with 50 ml of CH3CH20H held in a dry ice-acetone bath for 20 min and the supernatant separated by centrifugation and flash evaporated.Residues from either sample type were re- suspended in H20 filtered through an anion exchanger and acidified. The arsonium analytes were partitioned into liquefied phenol which was diluted with CH3CH20H and back extracted with H20. The combined aqueous extracts were evaporated re-dissolved in CH30H concentrated to 1 ml and separated on a cyanopropyl bonded-phase column with a mobile phase of CH30H-CH3CHz0H-CH3COOH (80+ 19 + 1) containing 0.12% triethylamine and 0.200 g 1-I picrylsulfonic acid.Analytes were detected on line by HGAAS. Recoveries from tissue that had been spiked with 0.1-2.8 pg of cation per gram of fresh mass were 83Oh or greater from each of the sample types. Holak and Specchio (92/2636) described simplified methods for the determina- tion of total As AsIII and AsV in foods by HGAAS. The sample preparation involved solubilization of total As by digestion with H2S04 HNO and HC104. Arsenic(Ir1) was extracted from the sample into CHC13 as chloride and then back extracted into the aqueous phase. After reduction with hydrazine sulfate and HBr to AslI1 AsV was similarly extracted.The method was applied to samples of lobster apple sauce mixed vegetable juice canned tuna scallops and squid. No As was detected in the mixed vegetable juice. Only apple sauce contained As"' (0.08 pg g-l). None of the samples contained detectable AsV. Recoveries of added As ranged from 95 to 10 1 O/o for total As 8 1 to 97% for As"' and 72 to 88% for AsV. Four As compounds were separated and detected by single- co 1 um n ion chroma tograph y with I CP-MS detect ion130R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 (93/409). The isobaric interference from ArC1+ was reduced by chromatographically resolving the chloride from the negatively charged As species. The effectiveness of the technique was demonstrated by the analysis of three chloride-containing matrices urine club soda and wine.Urine is used as an indicator of exposure to As and the soda and wine were chosen a possible vehicles for poisons. The LODs obtained for As in wine were 0.16 ng for As"' 0.26 ng for AsV 0.073 ng for dimethylarsinic acid (DMA) and 0.18 ng for monomethylarsonic acid (MMA). Sensitiv- ity was further improved by using an He-Ar mixed gas ICP as the ionization source but the intensity of the ArCl+ interference was also increased. For club soda the LODs using this type of plasma were 0.063 ng for AsIII 0.037 ng for AsV 0.032 ng for DMA and 0.080 ng for MMA. The LODs for urine and wine were similar. Gel permeation chromatography has been used to investi- gate the speciation of Cd and Zn in commercial vegetable foods with detection by ETAAS (93/447) and the speciation of 12 elements (Br Ca C1 Cu Fe K Mn P Rb S Sr and Zn) in lamb's lettuce and cauliflower with detection by TXRF (92/2780).A combined detection system for HPLC was reported for the study of the speciation of Fe in fruit juice and wine (92/2008). An electrochemical detector was used for FeI1 detection and on-line FAAS for total Fe. The LODs for each technique were 1 ng for Fe"' and 5 ng for total Fe respectively. The predominant species found in apple juice were iron(m) malate and citrate and in white wine iron@) and iron(m) tartrates. 2.4. Developments in Methodology for Electrothermal Atomic Absorption Spectrometry The determination of La by ETAAS is often problematic because of poor sensitivity and memory effects attributed to carbide formation resulting from interaction between La and the C from the atomizer.The use of a graphite tube lined with tungsten foil for the determination of La in food and water samples has been reported (92/3842). The lining was prepared from a rectangular strip of tungsten foil of 99.967% purity and formed by winding the strip around a glass rod with a diameter slightly less than that of the graphite tube. The lining was inserted into the centre of a new pyrolytic graphite coated graphite tube and a metal rod placed into the tube and firmly rolled inside it to attach the tungsten lining to the inside wall of the graphite tube. To prevent the foil from distorting on heating the tube was treated by pre-heating it over a programmed temperature range from 50 to 2500 "C.This was followed by a series of blank firings using the temperature programme for the measurement of La. The lifetime of the tungsten atomizer was about 130 firings. No memory effect for La was found with the use of this atomizer and the RSD ranged from 5.9 to 9.9%. Accuracy was determined by the recovery of standard additions of La to samples. Recoveries ranged from 73 to 103% and the LOD was 7.85 x g. Results for samples were in good agreement with those obtained by In a conference presentation Bruhn et al. (93/C165) described a low-cost tungsten coil atomizer (LCTA) for use as an inexpensive ETAAS alternative to supplement flame instruments. The LCTA was optimized using a laboratory- built electromechanical three step power unit with a temperature-time programme consisting of a drying a mineralization and a vaporization/atomization step.Cad- mium Ni and Pb were measured in water samples and beverages. The LOD for Cd was 0.6 pg; for Ni 12 pg; and for Pb 23 pg. Within-day reproducibility of measurements (expressed as the RSD) ranged from 2.7 to 7.5% and between-day from 4.9 to 7.9%. Results for NIST SRM 1643c Water were in good agreement with the certified values. ICP-AES. The addition of Ba to a Pd(NO,),-Mg(NO,) chemical modifier allowed Se to be determined free of interference from sulfate by ETAAS (92/4565). The recovery of 1 ng of Se which had been added to various mineral and medicinal waters with high sulfate content ranged from 89 to 99%. When no Ba was added to the modifier the recoveries ranged from 83 to 98%.The Se content of all the waters was less than 3 pg 1-l. Ultratrace levels of Ge were measured in mineral water and some Chinese health foods such as ginseng and royal jelly by Zeeman-effect ETAAS with Pd as chemical modifier (93/693). The ashing temperature was raised to 1400 "C to remove interferents with a significant improvement in sensitivity. The possibility of simultaneous determination of Cd Fe Mn and Pb in drinking water by Zeeman-effect ETAAS was described (92/2094). 2.5. Developments in Methodology for Plasma Emission Spectrometry Dolan et a1.(92/2396) described the use of preconcentration combined with on-line oxidation to improve the AE LOD for ICPs formed in Ar and He. Current LODs for ICP-AES are not adequate for determining I in most foods.The process was automated with FI. Two forms of I were studied I- and 103-. The preconcentration medium was a mem- brane disc containing the AG 1 -X8 anion-exchange resin within a polypropylene housing. Using test solutions preconcentration was coupled with on-line oxidation of I- to I2 to enhance analyte transport to the plasma. The combined technique improved the LOD of I as I- and 103- in aqueous solution by a factor of 207 (0.75 ng ml-l) and 15 (3 1 ng ml-l) respectively. Improvement factors for on-line oxidation of I- were 33 and 100 respectively for Ar and He plasmas. Further improvement could be made if a suitable digestion procedure was developed. Molybdenum was determined in various types of food by slurry sampling fluorination-ETV-ICP-AES using PTFE as the fluorinating agent (92/26 15).Slurries were prepared from dry charred samples with the addition of varying amounts of PTFE depending upon the sample (pollen spinach or garlic). Milk powder and wheat flour slurries were also prepared without drying and charring the samples. Molybdenum was added so that the slurries contained 0 10 30 and 100 pg 1-l of added Mo. After optimizing the ICP conditions the pneumatic nebulizer was replaced by an ETV system. A 10 pl volume of slurry was deposited into the furnace and drying and ashing steps initiated. After ashing was complete the injection hole of the furnace was sealed with a graphite rod and the sample vaporized. The desolvated vaporized sample was carried into the plasma by the Ar carrier gas. Calibration was by standard solutions of Mo containing PTFE.Recoveries of added Mo ranged from 92 to 105%. Results for NIST SRMs 1567 Wheat Flour 1568 Rice Flour and 1577 Bovine Liver were in good agreement with certified values. The use of PTFE as a fluorinating agent was found to enhance the sensitivity for the determination of Mo by ETV-ICP-AES and also eliminated memory effects. Other workers (92/1866) have reported that K might be determined more accurately by ICP spectrometry if stan- dard additions are used for solution concentrations of about 20 pg ml-l. For samples containing 1-5 pg ml-l of K measurement using 10 pg ml-1 of Na as the standard for optimizing the position of the analytical line in the plasma gave results with good recoveries at a wavelength of 766.49 nm.The sensitivity of ICP-AES for Ni measurements was improved by extraction of the Ni in biological samples by 1,s - bis(di-2-pyridylmethylene)thiocarbonohydrazide (92/20 14). The use of this extraction agent enabled determi- nation of Ni concentrations 15 times lower than thoseJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 131R determined by a non-extractive procedure. A novel method for the determination of phytic acid was reported (921C3383). The phytic acid was first separated and concentrated by ion-exchange chromatography followed by quantitative determination as P by ICP-AES. 2.6. Developments in Methodology for Inductively Coupled Plasma Mass Spectrometry Schmit et al. (921252 1) have described a general method for the quasi-simultaneous determination of most of the ele- ments present in biological materials by ICP-MS.Sample pre-treatment consisted of microwave dissolution followed by an appropriate dilution. Rhodium was used as the internal standard. The accuracy of the measurements was assessed by the multi-element analysis of NIST SRM 1577a Bovine Liver. Of the 18 elements measured 14 were within the certified values. The four elements which differed were Al Cu Hg and T1. For Cu and T1 the error was very small. For A1 and Hg the errors were thought to be due to contamination and a certified value below the LOD of the method respectively. The sensitivity of the method was assessed by measuring the recovery of elements added to fish muscle tissue. Five determinations were made for each element in the multi-element determination mode.The results for the spike recoveries showed that the elements fell into five groups with regard to sensitivity the lowest spike recoveries of 0.124 k 0.002 ng ml-1 were obtained for Ag Co Cr Li Mn Mo Sb Sr T1 VandY; for As Ba Cd Hg Pb Sn Zr and U 0.24 1 A 0.008 ng ml-1 was recovered; for B Cu Ni Rb Se Ti and W 0.487~0.015 ng ml-* was recovered; for A1 and Zn 0.97 k 0.06 ng ml-1 was recovered and in the final group 9.93 k 0.76 ng ml-1 were recovered for Bi Fe Sc Si and I. Other workers have used the semi-quantitative mode of analysis (92/288 1). The manufacturer claims that this mode of analysis (as opposed to the fully quantitative mode) can give results with a relative error of 30% or less. It was found that correcting the Saha-factors in the database using standard solutions gave semi-quantititative data for NIST SRMs 1577a 1566 and 1643b which differed from certified values by a relative error of 10%. A conference presentation (931C54) reported data for 66 elements measured using the semi-quantitative mode.A formalized scheme for assessing the quality of data from the analysis of food contact paper and board samples was devised. The LODs for the analyses based on five standard deviations of the blank ranged from 0.02 to 486 mg kg-l with over 90% of the elements having LODs below 10 mg kg-'. In another conference presentation (921C709) the multi- element analysis of cattle feed animal tissues and milk by ICP-MS after microwave dissolution was reported. Arsenic Cd Co Cu Fe Mg Mn Pb and Zn were measured in these samples following the importation of contaminated cattle feed into the UK.This work has subsequently been published (Food Add. Contam. 1992 9 365). Evidence that the form of Hg present in samples and standards can influence its determination by ICP-MS was presented (921C342). During an inter-laboratory study to determine Hg in cod muscle the results obtained by ICP- MS were lower than those obtained by CVAFS. Samples had been digested by a closed vessel microwave digestion procedure in both cases. Good agreement between the techniques was obtained if standard additions and isotope dilution techniques were used but only when the analyte additions were made prior to a cold HN03 overnight digestion stage. The group at the University of Plymouth gave two conference presentations reporting the use of chromato- graphy coupled to ICP-MS.The As content and its specia- tion in algal supplements for vegetarian and vegan diets were determined (931C58). A strong anion-exchange resin was employed to retain any chloride in the matrix which might interfere with the As measurements. A two-stage eluent system separated out the As species. The addition of N2 to the Ar plasma was also reported to reduce the chloride interference. The second presentation (931C59) reported the use of a chelating resin with iminodiacetate functional groups for retaining analytes of interest in food and biological materials (Cd Cu Mn Pb V and Zn) whilst potential interferents such as C1- Sod2- and Na+ are eluted to waste.The analytes can then be eluted and detected by ICP-MS. Owen et al. (9214 104) investigated the feasibility of multi- element and multi-isotope determinations by ICP-MS with on-line chromatographic separation of protein matrices. Size-exclusion chromatography was used to separate a known mixture of proteins and the behaviour of associated elements was monitored. Reversed-phase chromatography was used to separate Zn-containing species in chicken meat that had been intrinsically and extrinsically labelled with stable isotopes of Zn. The ratio for the intrinsic label agreed with that obtained by other workers using TIMS. Time- resolved software permitted rapid multi-element and multi- isotope data acquisition thus reducing the number of chromatographic runs required.It was concluded that further improvements in the software would add to the advantages that this technique offers. The 70Zn:68Zn ratio was measured in food blood faeces and urine following digestion and extraction of the samples (92/C34 10). The samples were obtained from pre-term babies. Under optimized conditions the 'OZn 68Zn ratio was determined for most samples with better than 1% precision. 2.7. Single and Multi-element Analyses of Foods Several papers report the migration of elements from cookware and glassware. The use of iron skillets for cooking apple sauce and spaghetti sauce was found to increase the Fe content of these foods when compared with the use of non-iron utensils (92/2843). Low levels of Cd and Pb measured by FAAS were released from ceramic ware into 4% acetic acid and grapefruit juice (92/3248).More than 0.1 ppm of Al B Ca Co Mg Na and Zn were detected by ICP-AES. The migration of Pb from lead crystal glassware into alcoholic beverages has been measured by ETAAS (9212842 93/C44 931C48). Some samples exceeded the maximum permitted Pb levels. For eight new decanters used to store whisky for 110 days the Pb content of the whisky originally assessed as containing less than 10 pg 1-I rose in the lowest instance to 20 pg - I but in the highest to 1300 pg 1-1 (93lC44). Factors affecting the Pb concentrations in drinking water on an American university campus were investigated (9211 82 1). The US Environmental Protection Agency is proposing a Pb standard for drinking water of 10 pg I-'. Water samples were collected from the supply mains distribution lines and drinking water fixtures in 14 build- ings that were up to 80 years old.Despite their age most fixtures delivered water with less than 50 pg 1-1 of Pb. Solder appeared to be the major source of Pb in drinking water although sediment in water contributed to the variability in Pb concentrations between and within build- ings. Cubillan et al. (931C129) reported the determination of A1 (by ETAAS) Ca Fe and Mg (by FAAS) and K and Na (by FAES) in Venezuelan drinking water. Aluminium was found to exceed both the upper concentration permit- ted by the Venezuelan Water Administration (=0.300 mg 1 - I ) and by international water standards (<0.100 mg 1-I) Values for Fe and K exceeded the USA upper132R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 values for these elements. The remaining elements were within the normal ranges established for these elements in the USA. Twenty- four elements were determined in human milk from Guatemala Hungary Nigeria The Philippines Sudan and Zaire (92/1824). A variety of techniques were used including AAS ICP-AES and NAA. Among the trace elements concentrations observed for As Cd Co Cr Cu F Fe Mn Mo Ni Pb Sb Se and V were higher in Filipino milk than from milk samples from the other countries. For all of the countries the environment appears to play a major role in determining the concentration of F I Hg Mn Pb and Se in human milk. The nutritional status of the mother as reflected by her socio-economic status does not appear to influence significantly the breast milk concentrations of minor and trace elements. It is important to note that significant differences were found between the actual daily intakes of elements from breast milk by 3 month old babies in this study and the current dietary recommendations made by for example the World Health Organisation and the US National Academy of Sciences.Similarly a study of Cr (measured by ETAAS) in Spanish human milk cow’s milk and infant formulae (93/673) found that the daily intake for Spanish neonates was lower than the recommended dietary allowances for this element. In Russia (92/1892) Pb and Sn in infant food conformed to recommended tolerances and the levels of A1 and Fe corresponded to national and the Food and Agriculture Organization’s requirements.The concentration of elements in canned foods continues to be of interest. Publications by Spanish workers reported the effects of canning peas on their mineral content (92/1774 93/835); the Cd and Pb content of fresh and canned asparagus (92/ 1776) and the role of processing and packaging in the contamination of foods by metals was reviewed (92/4262). Iron and Sn were measured in Chinese canned foods (92/2435) and Pb was determined in fresh and canned pineapple by ID-MS (92/1288). In the latter publication the sources of Pb were identified by their isotopic signatures. Pineapple in soldered cans contained Pb 60-80% of which came from the solder. Lead concentra- tions in fruit in welded cans were approximately 2.5 times lower than in soldered cans but up to 80 times greater than were found in fresh pineapple.Concentrations of trace elements have been reported for a variety of fresh fruit and vegetables. Mushrooms grown in the vicinity of a lead smelter in central Bohemia in Czechoslovakia (92/207 1 ) were found to contain elevated levels of Cd Cu Hg and Pb for samples collected 6 km or less from the source. Kiwifruits were found to be a good source of Fe and K (92/ 18 15). The Ca and Na content of fruits and vegetables (92/426 1) and the influence of environmental contamina- tion on the heavy metal content of vegetables (92/2848) were determined by Spanish workers. Energy dispersive XRF was used as a rapid method for the measurement of trace elements in milk powder (9211 726). The LODs were close to 1 ppm for most of the trace elements determined.Good agreement was found between the measured and expected results for IAEA SRMs. Chlorine P and S were measured in flours of wheat barley maize rice field beans and soybean by wavelength disper- sive XRF (92/2066). The method was found to be rapid accurate and precise and suitable for routine analysis. Nielson et al. (9212841) used multi-element XRF to measure Ca C1 Cu Fe K Mg Mn P S and Zn in 190 samples of 72 fruits vegetables and grain products. Accu- racy was validated using NIST SRMs and separate AAS measurements. Variations in short-term analytical preci- sion and sample heterogeneity gave RSDs of 4 and 4.7% respectively. The same technique was used by this group to measure As in the seafood fraction of fast foods (92/4033).Total As contents in single servings of seafoods may account completely for the average US As intake if one serving is consumed every two to ten days. A third publication by Nielson et al. (92/4032) reported the use of non-destructive XRF to screen for elevated Pb and Sn levels in fruit and vegetables. 2.8. Progress on the Determination of Some Individual Elements 2.8.1. Aluminium Compared with the previous year’s review there are fewer publications dealing specifically with Al. The following reports all concern beverages. Three papers report data for A1 in beer using ETAAS (92/2829 92/2830 93/C873). In the latter report the use of aluminium barrels for the storage of beverages in particular beer and flavoured soda waters was investigated.Aluminium was measured in Turkish tea samples by ETAAS (93/C 15 1) and in tap water following concentration onto a PTFE membrane (93/578). 2.8.2. Mercury As for Al the number of publications reporting total Hg data has decreased this year. Two published papers (92/3055 9315 10) and three conference presentations (92/C852 93/C118 93/C12 1) all report optimization of digestion conditions for CVAAS determination of Hg. 2.8.3. Selenium Selenium was determined in blood and food samples by ETV-ICP-MS (92/1461). An LOD of 2 ng ml-l was obtained for sample sizes of 10-50 p1 with a sample throughput of one every 5 min. Dabeka and McKenzie (92/2663) used ETAAS to measure the Se content of 22 types of food. The samples were measured after sequential digestion with HN03 dry ashing and coprecipitation with Pd.Palladium was used as a carrier and chemical modifier during the analysis. For a 1 g sample mass the LOD of the method was 18 ng g-l. The use of a combined wet digestion and dry ashing procedure was found to be a more effective use of the analyst’s time compared with the time required for complete wet digestions with H2S04. Ekholm et al. (9212725) have continued with their investigation of the effect of the Finnish policy of adding Na2Se04 to multi-nutrient fertilizers in order the raise to Se content of Finnish foods. In all cases the Se supplementa- tion of fertilizers increased the Se levels in domestic agricultural produce. The highest contents were in kidney liver and roe and the lowest in some fruits and berries.Cereals meat dairy products eggs and fish respectively contributed 26 29 20 10 and 9% of the total dietary Se intake. Another group of Finnish workers have reported the determination of Se in diets and foods by ETAAS without the use of solvent extraction (92146 12). They found that the use of a mixed Pt-Mg chemical modifier overcame ob- served interferences and resulted in the best stabilizing effect. The Se content of Turkish diets was determined using Zeeman-effect ETAAS (92/2889). Samples were collected from two different socio-economic (rural and urban) groups of the population digested with HN03 and H202 and analysed using Ni as a chemical modifier. The Se intakes for the rural group were lower than the range for a safe and adequate intake whilst the urban group’s intake was just within the range.Selenium in selected RMs and fish tissue was determined by HGAAS (92/1769). Radiotracer experi- ments indicated that the addition of a small volume of HC1 to the wet digestion mixture reduced slight losses of Se asJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL. 8 133R the tissues went to dryness before ashing. Selenium spiked as selenomethionine behaved more like Se in the RMs than did the inorganic Se spike. The speciation of Se in breast milk and blood was investigated using stable isotope tracers and detection by GC-MS with isotope dilution analysis (92/4098). All the women studied retained more Se from selenomethione than from selenite but lactating women retained more Se from selenite than non-lactating women.This suggested that milk losses of Se might be partially compensated for by enhanced retention of selenite. Two reports from China describe the detemination of Se in eggs. Zeeman-effect ETAAS was used to develop a method for analysing the egg white and yolk separately (9214669). The method consisted of digestion with HN03-H202 in a microwave oven. The second report (92/C581) compared four digestion methods for use with HGAAS. Methods which involved wet ashing with either HN03-HC104 or HN03-(NH4)2S204 mixtures and pres- sure bomb digestion with HN03 gave good recoveries and RSDs of less than 10%. Wet digestion with HN03-H2S04 did not decompose the organic material completely and gave low results. 2.8.4. Vanadium Vanadium(4 in tap water was measured after separation and concentration of the V ions using oxine (quinolin-8-04 and activated carbon as a collector (921 1880).Detection was by ETAAS. A preconcentration system that enabled a 300- fold enrichment of Vv to be achieved was described for use with FAAS (921461 5). Again oxine and activated carbon were used in the enrichment step. Linear calibration was achieved over the concentration range 10-120 ppb. The RSD was found to be 3% for a V concentration of 100 ppb. The procedure was applied to the determination of Vv in some vegetable samples. Spinach contained the highest (2.0 ppm dry mass) concentration of Vv. 2.9. Characterization Studies Determining the country of origin of various imported commodities and assessing the authenticity of food pro- ducts are both areas to which increased attention is being paid.Schwartz and Hecking (92/2618) reported the deter- mination of geographic origin of orange juice pistachio and macadamia nuts. Samples were analysed by ICP-AES (for B Ba Ca Cu Mg Mn P and Zn) and by FAAS (for K and Rb). Multivariate analysis of the trace element composition and mathematical models were used to predict geographic origins. The accuracy of these models was assessed using re- substitution and cross-validation analysis for the orange juice and macadamia nut samples and by the calibration set-prediction set method for the pistachio nut samples. Perfect prediction results were achieved for pistachio nut samples; i.e. the 33 samples were correctly assigned to one of the following places of origin Afghanistan California Iran Sicily or Turkey.For the orange juice and macademia nut samples re-substitution analysis indicated prediction accuracies of 96 and 98% respectively while cross - validation results indicated 88 and 78% respectively. Principle component analysis was used to differentiate between raw and commercial milk (92/4338) and to characterize potable waters (921C3757). The latter report used data acquired by ICP-MS. Data acquired for 15 elements in orange juices by ICP-AES (92/C3307) was used in a computerized recognition programme to identify the country of origin. By upgrading the system so that the programme has ‘learning ability’ the success rate for predicting the growing region of the oranges was increased and sample test prediction was very fast.Honey samples were measured by FAAS for nine elements (931C126). It is known that natural honey is rich in K and its concentration could help discriminate natural honey from adulterated honey. 2.10. Reference Materials and Collaborative Trials Roetlands (9214702) has reviewed and gives details of the information available about biological and environmental RMs. Isotope dilution-ICP-MS has been used to determine the total Sn levels in a proposed NIS SRM Fish for use in speciation studies of total Sn tributyltin and triphenytin (9214703). Five new RMs wheat flour potato powder carrot flakes animal muscle and high density protein were anlysed with NIST SRM 1577 Bovine Liver by ICP-MS (921C390). The LODs for elements measured by a multi- element procedure ranged from 0.1 to 60 ng g-l.134R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1993 VOL.8 LOCATION OF REFERENCES The full list of references cited in this Update have been published as follows 92lC339-921425 J. Anal. At. Spectrom. 1992 7( l) 53R-66R. 92lC426-9211447 J. Anal. At. Spectrom. 1992 7(3) 1 19R-154R. 9211448-9212589 J. Anal. At. Spectrom. 1992 7(4) 173R-213R. 9212590-92lC3494 J. Anal. At. Spectrom. 1992 7(5) 247R-277R. 92lC3495-9214073 J. Anal. At. Spectrom. 1992 7(6) 329R-348R. 9214074-9214734 J. Anal. At. Spectrom. 1992 7(8) 389R-411R. 93lCl-93lC997 J. Anal. At. Spectronz. 1993 8( l) 45R-77R. Abbreviated forms of the literature references quoted (excluding those to Conference Proceedings) are given on the following pages for the convenience of the readers.The full references names and addresses of the authors and details of the Conference presentations can be found in the appropriate issues of JAAS cited above. Abbreviated List of References Cited in Update Analyst 1991 116 957. 921409. Analyst 1991 116 965. 921413. J. Anal. At. Spectrorn. 199 1,6 385.921414. J. Anal. At. Spectrom. 1991 6 389. 921415. J. Anal. At. Spectrom. 1991 6 393. Analyst 1991 116 1013. 921941. Analyst 1991 116 1033. 921947. J. Anal. At. Spectrom. 1991 6 457. 921950. J. Anal. 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Scanning Microsc. 1990,4 853. 9212160. Second. Ion Mass Spectrom. SIMS 7 Proc. Int. Conf. 7th 1989 (Pub. 1990) 503. 9212254. Guang- puxue Yu Guangpu Fenxi 1991 ll(2) 48. 9212255. Guangpuxue Yu Guangpu Fenxi 199 1 11( 2) 52. 9212258. Anal. Hazard. Subst. Biol. Mater. 1991 3 63. 9212259. Anal. Hazard. Subst. Biol. Mater. 1991 3 81. 9212260. Anal. Hazard. Subst. Biol. Mater. 1991 3 109. 9212261. Anal. Hazard. Subst. Bio. Mater. 1991 3 171. 9212262. Anal. Hazard. Subst. Biol. Mater. 1991 3 193. 9212321. Second. Ion Mass Spectrom. SIMS 7 Proc. Int. Con 7th 1989 (Pub. 1990) 323. 9212392. Anal. Chem. 1991 63 2253. 9212396. Anal. Chem. 199 1 63 2539. 9212416. Fenxi Huaxue 199 1 19 443. 9212426.Fenxi Huaxue 1991 19 605. 9212434. At. Spectrosc. 1991 12 54. 9212435. At. Spectrosc. 1991 12 59. 9212436. At. Spec- trosc. 1991 12 69. 9212437. At. Spectrosc. 1991 12 74. 9212438. At. Spectrosc. 199 1 12 77.9212464. Spectroscopy (Eugene Oreg.) 1990 5(8) 31 36. 9212479. Anal. Sci. 1991 7 447. 9212487. 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