ATOMIC SPECTROMETRY UPDATE Clinical and biological materials, foods and beverages Andrew Taylor,*a Simon Branch,b David J. Halls,c Linda M. W. Owend and Mark Whitee aSupra-Regional Assay Service Trace Element Laboratory, Centre for Clinical Science and Measurement, School of Biological Sciences, University of Surrey, Guildford, Surrey, UK GU2 5XH. E-mail: A.Taylor@surrey.ac.uk bThe Lord Rank Centre, R. H. M. Technology, Lincoln Road, High Wycombe, Buckinghamshire, UK HP12 3QR cTrace Element Unit, Department of Clinical Biochemistry, Glasgow Royal Infirmary University NHS Trust, Castle Street, Glasgow, UK G4 0SF dMinistry of Agriculture, Fisheries and Food, CSL Food Science Laboratory, Norwich Research Park, Colney Lane, Norwich, UK NR4 7UQ eHealth and Safety Laboratory, Health and Safety Executive, Broad Lane, SheYeld, UK S3 7HQ Received 28th January, 1999 Analysis of clinical and biological materials 11.1 General reviews and articles 1.2 Sampling and sample preparation 1.2.1 Sample collection and pretreatment 1.2.2 Solid and slurry sampling 1.2.3 Sample digestion 1.2.4 Preconcentration 1.3 Developments in and applications of multielement techniques 1.3.1 Atomic emission spectrometry with the inductively coupled plasma and the microwave induced plasma 1.3.2 Inductively coupled plasma mass spectrometry and other mass spectrometric techniques 1.3.2.1 Reviews 1.3.2.2 Overcoming interferences in quadrupole ICP-MS (Q-ICP-MS) 1.3.2.3 Multielement determination by Q-ICP-MS 1.3.2.4 Laser ablation ICP-MS 1.3.2.5 Electrothermal vaporization ICP-MS 1.3.2.6 Double focusing magnetic sector ICP-MS 1.3.2.7 Determination of stable isotopes by mass spectrometry 1.3.2.8 Accelerator mass spectrometry 1.3.3 X-ray fluorescence spectrometry 1.3.4 Other multielement techniques and studies 1.4 Developments in single element techniques 1.5 Reference materials and quality assurance 1.6 Hair and nail analysis 1.7 Drugs and pharmaceuticals 1.8 Marine and freshwater biology 1.9 Progress for individual elements 1.9.1 Aluminium 1.9.2 Antimony 1.9.3 Arsenic 1.9.4 Bismuth 1.9.5 Boron 1.9.6 Bromine 1.9.7 Cadmium 1.9.8 Calcium 1.9.9 Chromium 1.9.10 Cobalt *Review co-ordinator, to whom correspondence should be addressed and from whom reprints may be obtained.Analysis of foods and beverages Sampling and sample preparation 1.9.11 Copper and zinc 1.9.12 Gallium 1.9.13 Germanium 1.9.14 Indium 1.9.15 Iodine 1.9.16 Iron 1.9.17 Lanthanides 1.9.18 Lead 1.9.19 Magnesium 1.9.20 Manganese 1.9.21 Mercury 1.9.22 Molybdenum 1.9.23 Nickel 1.9.24 Platinum group metals 1.9.25 Selenium 1.9.26 Silicon 1.9.27 Silver 1.9.28 Sodium and potassium 1.9.29 Strontium 1.9.30 Titanium 1.9.31 Thallium 1.9.32 Tin 1.9.33 Tungsten 1.9.34 Uranides 1.9.35 Vanadium 1.10 Conclusions 22.1 2.1.1 Extraction 2.1.2 Digestion 2.1.3 Preconcentration 2.2 Speciation 2.3 2.4 2.5 Developments in methodology for flame atomic absorption spectrometry Developments in methodology for electrothermal atomic absorption spectrometry Developments in methodology for inductively coupled plasma mass spectrometry 2.6 Progress in individual elements 2.6.1 Arsenic 2.6.2 Iodine 2.6.3 Mercury 2.6.4 Selenium 2.7 Single and multi-element analysis of food 2.7.1 Wine and alcoholic beverages J.Anal. At. Spectrom., 1999, 14, 717-781 7172.7.2 Metal contamination in food 2.8 Dietary intake studies 2.9 Characterization studies 2.10 Reference materials and collaborative trials Table 1 Analysis of clinical and biological materials, foods and beverages References 3T his update presents work published through to October, 1998. Of the developments mentioned in our 1998 review we observed continuing interest in in vivo measurement of lead in bone by XRF, new (or renewed) methods for tissue solubilization and increasing use of high resolution ICP-MS.Application of tungsten coil atomizers were again reported. T his included further use of portable atomic absorption spectrometers but a new area was electrothermal vaporization of analytes into an ICP mass spectrometer. Of new equipment, electrospray mass spectrometry was used by several workers.A resurgence of interest in the metabolism of aluminium was seen and there are reports of lead in plasma being associated with caeruloplasmin, the copper containing protein. Finally, various authors made use of Monte Carlo systems. None, however, have suggested that the chances of winning at roulette are increased. 1 Analysis of clinical and biological materials Advances in the determination of major, trace and ultratrace elements in clinical and biological materials by atomic spectrometric techniques are reviewed for the year ending approximately October, 1998.Table 1 summarizes the publications and relevant conference presentations while the text describes the more important publications and covers themes of current interest. 1.1 General reviews and articles 18 Speciation of clinical and biological materials is discussed in three recent general articles. Cornelis et al.1 give background information about sample preparation and handling, which is critical to maintain the integrity of the species.The need for speciation is discussed by Sanz-Medel2 and analytical strategies to tackle speciation are reviewed. If speciation is to become established in routine laboratories for quality control, environmental protection and regulation, then it must be faster and more reliable, as £obinski et al.3 rightly argue. They described processes developed for microwave leaching and derivatization for alkyl and aryl compounds of Hg, Pb and Sn, reducing preparation time to a few minutes.Separation by GC was possible in under 2 min on an isothermal multicapillary column only 22 cm long; this has the potential of producing a compact accessory for an atomic spectrometer. They presented a solution to the problem of an ICP mass spectrometer not tolerating the high concentrations of methanol used in reversed-phase HPLC. On-line dilution was used and the diluted eluate was passed to a low-consumption DIN.Faster LC is possible by decreasing the particle size and increasing the homogeneity of the packing. They demonstrated a complete separation of cobalamin species in under 2 min by using a 50 mm long column of non-porous C packing of particles of size 1.5±0.17 mm. Schramel4 reviewed modern techniques for trace element analysis and speciation. Recent developments in analysis of trace elements in clinical samples, which have been covered in recent Updates, feature in a review by Taylor.5 Last year's Update6 reviews publications appearing in the year up to about October, 1997.718 J. Anal. At. Spectrom., 1999, 14, 717-781 1.2 Sampling and sample preparation 1.2.1 Sample collection and pretreatment. The risk of infection from viruses can be reduced by lowering the pH of the sample, according to Veillon et al.7 Samples were diluted 1+4 with 0.1 M HNO3 which lowered the pH to about 1.5 without precipitating proteins.Samples could then be transferred safely from the sample handling area to the analytical laboratory for determination of Se by ETAAS. Microwave irradiation can facilitate deproteinization steps, as Bohrer et al.8 demonstrated. More than 99% of the protein in serum was removed after irradiating a 1+1 dilution with 1% m/v TCA. This concentration is 10-fold lower than is conventionally used for deproteinization. They applied the technique in the determination of Al in serum by ETAAS. Precipitates often form in urine samples on standing.Burden et al.9 showed by X-ray microanalysis that this contained mainly Ca and P but also could include some trace metals. To ensure complete dissolution in the determination of Al in urine by ETAAS, they diluted the urine 1+1 with 0.22 M HCl, warmed it to 40 °C and then allowed it to cool to room temperature.Krachler et al.10 compared simple dilution, UV irradiation and microwave digestion with HNO3-H2O2 for determining a range of trace elements in urine by ICP-MS. Simple dilution required a higher dilution ratio to obtain a stable reading than the digested samples but the LODs were comparable and all techniques gave accurate results. Comparison of results on digestion of urine with and without the sediment showed significant diVerences for Pb but not for Cd, Co, Cr, Ni, Sb, Sr and V.1.2.2 Solid and slurry sampling. In two recent applications of direct solid sampling, the high organic content found in most biological samples was removed in a pretreatment step. By using prior dry ashing externally, the resulting ash contains the element at a concentration 10-40-fold higher than in the original material. Applying this to the determination of Se in biological materials, Minami et al.11 used a Pd modifier to prevent volatilization.Selenium in the ash was then determined 3.3 ng g-1 compared to 0.13 mg g-1 for determination in the by solid-sampling ETAAS. The LOD in this case was original material directly. Results on CRMs using simple aqueous solutions for calibration were in good agreement with the certified values. To determine Cd and Pb in biological materials, Okamoto et al.12 used ETV-ICP-AES. The sample, mixed with (NH4)2HPO4, was ground to a fine powder. A portion (10 mg) of the powder, placed in a tungsten boat furnace, was digested in-situ with TMAH at 130-150 °C.After pyrolysis, a vaporization step produced Cd and Pb atoms which were transported into the ICP. Calibration was with CRMs. Although 2% nitric acid was shown by Bermejo-Barrera et al.13 to eYciently extract Ni from slurries of hair in determination by ETAAS, no improvement in results was seen when compared with simple suspension of powdered hair in deionized H2O.Glycerol was added as a stabilizing agent and Mg(NO3)2 was the chemical modifier. However, Meeravali and Kumar14 found that slurries of biological CRMs were not stable for most elements in glycerol but were stable in 5% HNO3, which extracted a high percentage of the elements Cd, Cu, Mn and Pb that they studied. Determination was by transverse heated ETAAS using a programme with no charring stage but a high-temperature drying stage. Although no modi- fier was used, direct aqueous calibration could be used without chemical interference for Cd, Mn and Pb, but for Cu, standard additions calibration was necessary.This was also the element with the lowest extraction (57%) into acid. Calcium-containing pharmaceuticals needed to be ground down to an average particle size of 3 mm to produce satisfactory results in thedetermination of Pb by slurry-sampling ETAAS using a Mo-tube atomizer.15 Thiourea was added to remove interferences and H2, added to the Ar atmosphere, gave increased sensitivity.Matrix-matched standards were used for calibration. Good agreement was found with results obtained after acid digestion. 4 1.2.3 Sample digestion. More applications of alkylamines as solubilizing agents were described. Tao et al.16 found that, when they used TMAH to digest biological tissues for the determination of Hg by FI-CVAAS, the sensitivity for various species of Hg diVered. To convert all forms to inorganic Hg, 0.2% m/v KMnO was added on-line.Dissolution in TMAH was complete in 30 min, allowing a high throughput of samples. Animal tissue CRMs were dissolved in TMAH by Pozebon et al.17 for the determination of a range of trace elements by ETV-ICP-MS. A small mass of sample, 20-100 mg, was mixed with 10-200 ml of 25% m/v TMAH to dissolve. In determination, Pd was added separately as a modifier. Tertiary amines are very suitable for retaining volatile elements such as I for determination as Krushevska et al.18,19 demonstrated.Simultaneous determination of I with other trace elements was then possible by ICP-MS. On-line digestion systems have been developed further. Gra�ber and Berndt20 described a high pressure system using a HPLC pump to supply pressure in a capillary which was resistively heated to 250-350 °C. Residual C was less than 1% after digestion. Previously, systems have been low pressure with microwave heating.Such a system was designed by Huang et al.21 for automated preparation of blood and serum for determination of trace elements by ICP-MS. Samples were pumped with an acid mixture into a Teflon tubing coil in a focused microwave oven. After passing through a cooler, the sample was transferred to an iminodiacetate-based resin column for retention of trace elements, separating them from the main matrix components. The analytes were subsequently eluted for determination. The whole system was controlled by an expert system.However technologically interesting this system is, the application to the determination of Cu, Fe, Ni, Pb and Zn in blood and serum at a rate of 6 samples h-1 does not seem to be progress when more direct and faster approaches are possible. For on-line determination of Hg in slurried samples, Lamble and Hill22 used a carrier stream of 3- and Br- and HCl, mixed the sample with a solution of BrO heated it in a coil in a microwave digestor for complete breakdown of methylmercury to Hg.Determination was by CVAFS. To speciate As in biological materials,23 they separated the species by HPLC, broke down the species to inorganic As by on-line microwave digestion, reduced AsV to AsIII with L-cysteine and then determined As by HGAAS. In the system developed by Burguera et al.24 for urine, the column eluate was directly coupled to HGAAS for determination of AsIII, AsV, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA).Total As was determined in a parallel flow system in which the sample was digested in a microwaveheated coil before determination. The advantage of the Lamble and Hill approach is that species, such as arsenobetaine, that are not reduced to a hydride can be determined, allowing a complete speciation. An alternative to microwave digestion for breakdown of As species to inorganic As is UV photooxidation.Tsalev et al.25 used this on-line after separation by HPLC on an anion-exchange column and prior to determination of As by HGAAS. The sample was mixed with alkaline peroxydisulfate and pumped to a PTFE knotted reactor, where it was irradiated for 93 s. Their system used an 8 W lamp but Ritsema and van Heerde,26 in their method, used a 500 W Hg lamp, adding H2SO4 and H2O2 for oxidation oV-line for 8 h before determining total As by HGAAS.The conditions seem somewhat excessive in view of the results obtained by Tsalev et al.25 A recirculating system for digestion using microwave heating was developed by Perez-Jordan et al.27 A powdered tooth sample mixed with HNO3 in a flask was pumped through PTFE digestion coils in a microwave oven and back to the flask. The flask was cooled in ice and stirred. After 10 min, the digest was analysed for Mg and Sr by FAAS and for Na and K by FAES.Modifications to microwave digestion systems to handle small sample masses have been described. Deaker and Maher28 used two 7 ml screw-topped vials placed within a normal 120 ml vessel. Samples of less than 0.1 g digested with 1 ml HNO3 in a multistage heating programme lasting 49 min gave quantitative recovery of Se from three marine biological CRMs when measured by ETAAS. Vapour-phase digestion with HNO3 in a commercial pressurized microwave digestion system was applied to samples of biological CRMs of weights 0.05-0.1 g in a study by Amarasiriwardena et al.29 Addition of 250 ml of H2O allowed coupling of microwave energy to the sample. Ultrasound was used with good eVect to assist the extraction of Se from biological materials with 4% v/v HNO3 by Mierzwa et al.30 Comparison with results from full digestion and with the certified values of the CRMs showed the eYcacy of the extraction.1.2.4 Preconcentration.The changing pattern of sample enrichment is illustrated by recent publications. Conventional liquid-liquid extraction was used by Bergerow et al.31 in the determination of Au, Pd and Pt in urine by ETAAS. An enrichment of 25-fold was achieved with extraction into MIBK with APDC. Liquid-liquid extractions can be carried out on-line in an FI system but it has been found more convenient to use sorption of the metal chelates on a knotted reactor; these are subsequently eluted. Ivanova et al.32 applied this to the determination of Cu, Mn and Ni in biological materials comparing APDC and 8-hydroxyquinoline as chelating agents. For Cu and Ni, APDC was better, giving enhancement factors o44 and 21, respectively, but could not be used for Mn.This was enriched up to 8-fold with 8-hydroxyquinoline. Developments in supported liquid membrane technology could rekindle interest in on-line liquid-liquid extraction. In their method for Pb in urine, Djane et al.33 used a fixed layer of 40% m/m di- 2-ethylhexylphosphoric acid in kerosene, forming a membrane above which was pumped sample with buVer at pH 3 and below 1 M HNO3.An extraction eYciency of 95%into the HNO3 phase with enrichment factors up to 200 could be attained in 45 min.Work by He et al.34 showed the possibilities with solid-phase microextraction. In determining methylmercury in biological materials, they introduced KBH4 into a GC vial to convert methylmercury to its hydride.A capillary fused-silica fibre, etched with HF, was inserted into the headspace above the sample for 90 min. The fibre was then transferred to a GC column where the methylmercury was desorbed and the Hg eluted from the column detected by AAS. In a study of the use of living organisms for metal speciation, Pe�rez-Corona et al.35 showed that baker's yeast immobilized on silica gel and packed in a PTFE microcolumn could retain both methylmercury and inorganic Hg, the former on the yeast and the latter on the silica.ganic Hg with 0.8 M CN-. Methylmercury could be eluted with 0.02 M HCl and the inor- 1.3 Developments in and applications of multi-element techniques 1.3.1 Atomic emission spectrometry with the inductively coupled plasma and the microwave induced plasma. An evaluation by De Wit and Blust36 of the microconcentric nebulizer 719 J. Anal. At. Spectrom., 1999, 14, 717-781(MCN) in the determination of metals by axial ICP-AES showed that the sample volume could be reduced to a few hundred ml for multielement analysis but the performance was poorer than with a standard concentric glass nebulizer.The eVects were element-dependent but for the MCN the LOD was on average 3.4-fold worse and the eVects of salt on signal stability were more pronounced. Nevertheless, the MCN could tolerate continuous nebulization of solutions containing up to 3.5% salt for several hours without blocking and, in the analysis of digests of biological CRMs, showed results with good accuracy and precision.Speciation studies by Bra�tter et al.37,38 using HPLC coupled on-line to ICP-AES (or ICP-MS) showed that the proteinbinding of trace elements in human milk was significantly diVerent from that in infant milk formulae. In the formulae, the binding pattern depended on the main component (cows' milk or soya milk), the processing and the chemical form of the trace element additive.To compensate for poor absorption, some elements were added at higher concentrations than are found in human milk. For example, Fe was up to 20-fold higher with a very diVerent binding pattern to that of human milk. In a second study from the same Institute,39,40 speciation of Cu, Fe, Sn and Zn in red-cell lysates by SEC-ICP-AES allowed identification of superoxide dismutase (containing Cu and Zn), catalase (Fe), haemoglobin (Fe, S), glutathione peroxidase (Se, S) and carbonic anhydrase (Zn).In healthy infants from birth to 4 months, the superoxide dismutase and catalase increased with age. The mineral composition of bones and similar materials is conveniently determined by ICP-AES. Changes with age in men's and women's calcanei were studied by Tohno et al.41 with both ICP-AES and dual-energy X-ray absorptiometry. Both showed age-dependent decreases in the mineral content for men over the age range 40-98 but not for women.In a second study on the same subjects,42 they looked at the mineralization of femoral arteries. The relative contents of Ca and P started to increase before the age of 60 but Mg only increased after the age of 70. Sulfur showed no significant change.Wollastonite (CaSiO3), a potential bone implant material which readily forms a layer of hydroxyapatite when in contact with body fluids, was analysed by De Aza et al.43 using ICP-AES for Ca and Si and for the impurities introduced in processing.The precision obtained in the determination of Ca and Si was said to be comparable to that achievable by gravimetric procedures. In a study on teeth, Capota et al.44 determined Al, Cd, Cr, Cu, Fe, Pb and Zn after ashing the samples in O prior to digestion with HNO 2 3-H2O2. The suitability of ICP-AES to determine refractory elements is shown in two recent studies.For determination of Ti in blood plasma of patients treated with a Ti-containing anticancer drug, Einha�user et al.45 investigated measurement by ICP-AES with an USN. Even with the preferred dilution of 1+99 with water, an LOD of 1-2 mg l-1 was achieved. Methods were also developed using ETAAS with longitudinal and transverse heating, the latter giving less tailing. The authors preferred ICP-AES as ETAAS suVered more from matrix and memory eVects.Tungsten was determined by ICPAES by Marquet et al.46 in the investigation of acute toxicity in a young soldier in the French artillery. He had drunk a mixture of beer and wine used to rinse a hot gun barrel. Higher than normal concentrations of W were found in his blood, urine, hair and nails. Iohexol, an iodinated radiographic contrast medium, can be used to estimate the glomerular filtration rate by following the elimination of I by XRF from blood plasma after injection.Braselton et al.47 showed that, by using a more sensitive ICPAES method to measure the I, a much lower dose of iohexol could be given. They determined I at the 178.3 nm line on the supernatant after precipitation of proteins from the plasma 720 J. Anal. At. Spectrom., 1999, 14, 717-781 sample with a TCA-based medium. Inter-element correction was necessary for interference by P which was measured at 214.9 nm. 1.3.2 Inductively coupled plasma mass spectrometry and other mass spectrometric techniques. 1.3.2.1 Reviews. Moens48 has reviewed applications of mass spectrometry in the determination of trace elements in biological materials, discussing also stable isotope tracer studies. 1.3.2.2 Overcoming interferences in quadrupole ICP-MS (Q-ICP-MS). Interferences in the determination of trace and ultratrace elements in biological fluids by Q-ICP-MS were discussed by Hsiung et al.49 They advocated the use of internal standards of close mass to correct for non-spectral interferences.Dilution also helped. For multielement analysis, fivefold dilution and four internal standards (Be, Ga, In and Ir) across the entire mass range gave adequate accuracy for most elements with simple external standards, but for Cs and Zn calibration with internal standards was necessary. Accurate results for Cu and Zn in serum and urine could be obtained by measuring the 65Cu and 68Zn isotopes, respectively.Cool plasma conditions can eliminate some polyatomic interferences, as Hedrick50 demonstrated. Addition of O2 as a C scavenger also helped, enabling the determination of 52Cr and 24Mg. A diVerent approach was used by Krushevska et al.51 for 52Cr. To reduce the C and Cl, they optimized acid digestion and then corrected for remaining ArC+ interference at mass 52 mathematically. The same approach was used for V, but Minnich et al.52 preferred cryogenic desolvation to condense Cl as HCl.This allowed the determination of V in urine for occupational monitoring. 1.3.2.3 Multielement determination by Q-ICP-MS. Twentysix major and trace elements in tissues (brain, lung, spleen, kidney, heart and liver) of 21 human fetuses of gestational age 16-22 weeks were determined in a study by Gelinas et al.53 Samples were prepared by microwave digestion. The range of concentrations found was generally much lower and much narrower than in adult tissues.In an assessment of variation within diVerent regions of five brains, no significant diVerence was found for any of the elements. Amyloid plaques in the brains of patients who had Alzheimer's disease were analysed by FI-ICP-MS by Beauchemin and Kisilevsky.54 The plaque cores, isolated by homogenization and gradient ultracentrifugation, were suspended in salt buVer and dissolved in HNO3. Concentrations of Al, Fe and Zn were relatively high in the extra the range 2-20 mg l-1, whereas Cr, Cu, Mn, Ni and Pb concentrations were between 0.2 and 0.8 mg l-1.A study, reported by Lutter et al.,55 used ICP-MS, ICPAES and NAA to determine toxic and essential metals and radionuclides in breast milk from mothers in Kazakhstan. Concentrations found were not abnormal compared with data from other countries and breast-feeding was considered safe. Bra�tter et al.38 used ICP-MS and ICP-AES to detect metals in the speciation of breast and formula milk by HPLC.The protein-binding pattern was very diVerent between breast and formula milk and even within the formulas there were diVerences depending on the main component, its treatment and the form of the inorganic supplement added. Copper and Zn were determined in plasma and urine after 20- and 10-fold dilution, respectively, by Szpunar et al.56 An internal standard, Y, was added and standard additions were used to eliminate matrix eVects.Copper was measured as 65Cu. Flow injection coupled to a DIN allowed determination in samples as small as 1-2 ml. 1.3.2.4 Laser ablation ICP-MS. Laser ablation ICP-MS in combination with gel electrophoresis was investigated jointlyby workers in SheYeld, UK, and Copenhagen, Denmark, for the speciation of trace elements in biological samples.57-59 Nielsen et al.58 separated the proteins in a serum spiked with Co by using two-dimensional electrophoresis.Proteins were identified by a staining technique. Laser ablation ICP-MS produced a map of the distribution of Co from which it was possible to conclude that the Co was associated principally with six major proteins. Further work59 assessed metal binding patterns in therapy with Au and Pt. To allow laser ablation of soft tissues, Ek60 froze samples been more publications and conference presentations on double focusing magnetic sector ICP-MS [or high-resolution to produce a hard surface for ablation.A special cell allowed ICP-MS (HR-ICP-MS)], enabling a better appreciation of its periodic introduction of liquid N2 to keep the sample frozen. potential. In this respect, the most informative are those which Calibration was with frozen standard solutions. Imaging of trace element distribution was possible. 'Fingerprints' of cannabis samples from Western Australia were obtained by Watling61 using laser ablation. Ground samples were pressed into cardboard mounts under high pressure. Ternary plots of ratio per cent.of particular elements measured by laser ablation ICP-MS allowed identification of the source of the cannabis. 1.3.2.5 Electrothermal vaporization ICP-MS. Electrothermal vaporization allows the use of slurries and more concentrated solutions, requires smaller volumes of solution and allows removal of water and matrix components, thus reducing interferences in the determination.Lanthanides are not an obvious candidate for ETV as they are refractory but Buseth et al.62,63 showed that the addition of Freon-23 (CHF3) to the Ar purge gas lowered the vaporization temperature and reduced memory eVects. Absolute LODs were 1-20 fg for all the lanthanides, allowing determination of lanthanides in serum down to LODs of 0.05-1.2 mg l-1. Blood samples from 90-350 ng l-1 for Pr, Nd and Gd but Ce was around 13 mg l-1, 30 healthy volunteers gave mean concentrations in the range possibly because of contamination from sample tubes.Comparison of results on tissue samples analysed by slurry sampling and after digestion showed similar accuracy and precision. Chemical modifiers are as important in ETV-ICP-MS as they are in ETAAS and much of the knowledge has been transferred from that technique. Pozebon et al.17 determined a range of elements in biological SRMs by ETV after treatment with TMAH to form solutions or slurries. Palladium was the chemical modifier for Ag, As, Cd, Co, Cr, Cu, Mn, Ni, Se, Te and V, but for Bi, Sb, Sn and Pb, an iridium-coated tube was used. The use of iridium-coating was examined by these authors in a separate publication.64 For the determination of As, Pb and Se, this allowed the pyrolysis temperature to be increased to 1300 °C.Although more than 100 firings could To monitor workers involved in nuclear fuel reprocessing, be obtained with each coating, gradual loss of sensitivity of Nanni et al.72 used HR-ICP-MS to measure Th and U in about 50% occurred over this lifetime, requiring frequent human urine.Samples were diluted ten-fold with addition of re-sloping of the calibration curve. Reduction of sensitivity matched standards. The LODs (0.26 and 0.01 mg l-1 for Th for Pb was much less significant. Water and urine CRMs were Bi as an internal standard and were measured against matrixanalysed with good accuracy.A novel method for speciation and U, respectively) can be compared to the LODs of 0.5 mg l-1 of Hg in biological tissues using ETV-ICP-MS was described for both elements reported by Schramel et al.73 for determiby Willie et al.65 Samples were solubilized with TMAH. Total above this (mean 8 and 10 mg l-1 for Th and U, respectively), Hg was determined without further treatment. Through the nation by Q-ICP-MS.As concentrations found72 were much addition of iodoacetic acid, acetic acid and sodium thiosulfate, either instrument would seem to have adequate sensitivity. To methylmercury was converted to methylmercury iodide, which measure very low levels of Pu and lanthanides in blood and was driven oV in the drying stage allowing only inorganic Hg urine, Pickford et al.74 used chemical separation methods to to be measured. The method was tested on marine biological preconcentrate samples and to reduce the matrix concen- CRMs.For determination of Hg in urine, Lee et al.66 compared tration. To eliminate interference from C, Pb and Th in the modifiers and found a mixed modifier of Pd, Mg(NO3)2 and determination by HR-ICP-MS, high grade reagents and clean 0.2% v/v HCl to be suitable. Spiking with the isotope 201Hg allowed quantitation by ID. Mercury was determined in NIST SRM 2670 Toxic Metals in Urine and in several samples from normal subjects.The LOD of the method was 0.02 mg l-1. In In a conference presentation, Garbe-Scho�nberg and Sievers75 further work,67 these workers described the determination of Cd and Pb in urine by ID using ETV-ICP-MS. A relatively low volatilization temperature (1000 °C) with 1% HNO3 as chemical modifier allowed separation of the analyte from the 0.005 mg l-1, respectively. major matrix components. The LODs were 0.02 and 1.3.2.6 Double focusing magnetic sector ICP-MS.There have have carried out a direct comparison with Q-ICP-MS. Kishiki et al.68 compared multielement determination of digests of animal tissue CRMs by both techniques. Results on NIST SRM 1577b Bovine Liver by HR-ICP-MS agreed well with certified values, except for P, Pb and V. The poor result for P could be explained by detector saturation. The reasons for low Pb and V results were to be investigated further. Results by Q-ICP-MS were good at high mass, but gave low results for Cd, Cu, Pb and Zn.In a comparison of the determination of the Pt group metals in urine, Krachler et al.69 concluded that Q-ICP-MS with USN was totally inadequate to quantify baseline concentrations but HR-ICP-MS with USN operated in low-resolution mode had adequate sensitivity, although it was still subject to potential interferences from 106Cd and 40Ar66Zn on 106Pd and 206Pb2+, 87Sr16O and 40Ar63Cu on 103Rh. Samples were digested by UV photolysis and diluted 1+19 for analysis.The LODs were 5, 0.6 and 0.5 ng l-1 for Pd, Pt and Rh, respectively, enabling studies to be made on the eVect of release of Pt group metals from catalytic converters in cars on urban children. On 30 young people, median concentrations found were 9.5, 1.0 and 11.7 ng l-1 for Pd, Pt and Rh, respectively. Using a similar method, Begerow et al.70 achieved better LODs in urine, 0.17 and 0.24 ng l-1 for Pd and Pt, respectively.Lower dilution, 4.2-fold, was used. They found higher levels in 21 adults (mean 140 and 1.8 ng l-1 for Pd and Pt, respectively). In a comparative study of ETAAS, Q-ICP-MS and HR-ICP-MS for the determination of Al in serum, Sariego Mun~ iz et al.71 found that lower LODs were possible with the IS techniques (0.35 and 0.85 mg l-1 for HR- and Q-ICP-MS, respectively) than with ETAAS (2 mg l-1). Although there were negligible matrix eVects for serum diluted 1+4 on the Q-ICP-mass spectrometer, matrix eVects were evident with the HR-ICP mass spectrometer even at 1+9 dilution, requiring the use of internal standards (Be and Sc).Even with HR-ICP-MS, most of the serum samples from healthy individuals were below the LOD (i.e., less than 0.35 mg l-1). room conditions were necessary to keep the concentrations of these elements low. In this way, it was possible to determine 244Pu down to 0.1 fg l-1 in urine.claimed that, using HR-ICP-MS, they could determine 721 J. Anal. At. Spectrom., 1999, 14, 717-781accurately major, trace and ultratrace elements in serum and urine using only a small volume of serum diluted by a factor of 20- to 100-fold. An internal standard was added to correct for matrix interference and for drift. Publication is awaited with interest. In order to monitor workers exposed to Cd and other metals, Townsend et al.76 developed a method of determining Cd, Cu, Pb and Zn in urine by HR-ICP-MS.A spectral resolution of 3000 was required to separate Cu and Zn isotopes from interference, but the resolution was dropped to 300 to achieve greater sensitivity in the determination of Cd and Pb. Samples were diluted 1+9, incorporating In as an internal standard. Simple external calibration gave results on urine RMs which were in the accepted range. Comparison of Cd results with those obtained by ETAAS showed good agreement.1.3.2.7 Determination of stable isotopes by mass spectrometry. In a comparison of the measurement of isotope ratios of Mg by electron-impact mass spectrometry (EI-MS) of volatile Mg derivatives with determination by ICP-MS after acid digestion of samples, Batel et al.77 showed that ICP-MS gave better precision (0.19% and 0.38% RSD within- and between-batch, respectively) than EI-MS (1.28% and 2.6%). The method was used to evaluate the bioavailability of a Mg pharmaceutical form in humans.A method developed by Woolard et al.78,79 used double focusing magnetic sector ICP-MS for the determination of all four stable Pb isotopes. Each sample was scanned 300 times and compared with a certified standard that had been isotopically characterized by TIMS. Isotope ratios could be measured to a precision of 0.07-0.22% RSD. Total analysis time was about 5 min. The method was applied to Pb isotope tracer studies in animals and humans.In a further variant of this method,80,81 improved precision (<0.1% RSD) was obtained by using 1200 scans per sample. A comparison of results on blood and dust samples with those obtained by TIMS showed agreement within the propagated s of both methods, but there was a small but significant bias which could not be explained. The method provided an equally precise but less costly and more rapid alternative to determination by TIMS. To interpret strontium isotope ratios in bones as a tool for studying dietary input from discrete geochemical environments, a precision in measurement of at least 0.1% RSD is required. Latkoczy et al.82 showed that, using HR-ICP-MS, they could achieve a precision of about 0.05% RSD.Compared to other more accurate and precise alternatives such as TIMS, the ease of operation and sample preparation together with the short analysis time (10 min) allowed HR-ICP-MS to handle numerous samples at reasonable cost.The technique was used in a study of skeletal remains from a Neolithic settlement in lower Austria. Becker and Dietze83 showed that HR-ICP-MS allowed interferencefree determination of the 39K540K ratio with a precision of 0.7% RSD and showed promising results for the determination of Ca and Mg isotope ratios. 1.3.2.8 Accelerator mass spectrometry. As in previous years, the main clinical application of this technique is to study the metabolism of Al using the isotope 26Al.On the basis of their measurements on human subjects, Kislinger et al.84 developed a model to describe the kinetics of elimination of Al. This model comprised a central compartment (blood and interstitial fluid) feeding three peripheral compartments. Excretion of Al was mainly from the kidneys into urine and, to a lesser extent, via the liver with faeces. In two patients with renal failure, a diVerence in the pattern of excretion was seen in comparison with that for healthy subjects.In rats, Zafar et al.85 found that 26Al accumulated to the greatest extent in bone, followed in order by spleen>kidney=liver>brain. Only 0.97% of the 722 J. Anal. At. Spectrom., 1999, 14, 717-781 dose was absorbed. The absorption of Al from Al-containing vaccine adjuvants was studied by Flarend et al.86 using rabbits. The area under the blood 26Al concentration curve for 28 d showed that three times more Al was absorbed from aluminium phosphate than from aluminium hydroxide.Yumoto et al.87 found that 26Al could cross the blood-brain barrier in rats and was not eliminated over 270 d whereas the 26Al in blood had mainly gone after 75 d. Studies by Barker et al.88 on mice showed that the role of transferrin in transporting Al may be less than originally believed. In rats with low serum transferrin concentrations, uptake of 26Al was similar to that in controls, except in bone. Mice treated with antibodies against the transferrin receptor also showed similar results to controls, except in spleen and muscle.They concluded that transport by citrate and other low-molecular mass complexes was important. The analytical methods used by the Manchester group were described in more detail.89 After pressure digestion of blood, plasma and tissue samples with HNO3, Al carrier was added and the Al isolated by selective precipitation with quinolin-8-ol.Ignition at 800 °C produced Al2O3 which was by AMS. The LOD for 26Al was 10-18 g. mixed with Ag powder for measurement of the 26Al527Al ratio Bone resorption measured with a 41Ca tracer by AMS gave results which were comparable to those obtained with conventional stable isotope measurements.90 Freeman et al. indicated that, in contrast with other Ca isotope tracers, 41Ca could be administered in such a way that a quasi steady state was achieved between the various body pools.Measurement of 36Cl and 129I in teeth and bones can provide information on exposure of individuals to fallout from nuclear weapons tests or emission of radionuclides from nuclear power stations. Cornett et al.91 developed a pyrolysis technique to liberate these elements from teeth and bone for measurement of the isotopes by AMS. Samples from human subjects who had been exposed to weapons fallout had elevated levels of these isotopes.1.3.3 X-ray fluorescence spectrometry. Development of invivo XRF techniques for estimation of heavy metal burden continues, although some evidence from clinical studies suggests that more traditional and simpler measurements of metals in blood and urine are more eVective. The first phase in the development of a faster, more accurate XRF system for invivo measurement of Pb in bone was reported by Niemela and they were able to reliably measure 17 mg Pbg-1 in a bone Grodzins.92 Using a monochromatic, polarized X-ray beam, below 5 mg Pb g-1.Ao et al.93,94 developed a Monte Carlo phantom and expected with further optimization to measure technique for the simulation of in-vivo XRF and applied it to reduce the eVect of Compton scattering by optimizing the source-sample-detector geometry in K-shell XRF and by using a polarized source for L-shell XRF. A Monte Carlo approach was used by Hugtenburg et al.95 to model the measurement of cis-platin uptake by in-vivo XRF.Under optimized conditions, an LOD of 50 mg g-1 was found. Clinical studies of the estimation of Pb burden were reviewed by Rosen.96 Kovala et al.97 studied the eVects of low-level exposure to Pb on neurophysiological functions amongst Pb battery workers. Exposure to Pb was assessed by both in-vivo XRF of Pb in tibial and calcaneal bones and from regular blood Pb measurement. Assessment of peripheral and central nervous system functions showed a correlation with long-term exposure to Pb.Blood Pb history showed a better correlation with the eVects of Pb than the bone measurements. They concluded that a more accurate estimate of health risk from Pb could be obtained from a history of blood Pb measurement. Cadmium in superficial liver tissue and in kidney cortex measured by in-vivo XRF was compared with blood and urine Cd measurements and records of Cd in workplace air levelsfor 30 Ni-Cd battery workers in a study by Boerjesson et al.98 Kidney Cd concentrations were above the LOD (30 mg g-1) for 63% of the workers while 48% had liver Cd concentrations above the LOD for that substrate (3 mg g-1).Kidney Cd correlated significantly with current blood and urine Cd concentrations; liver Cd correlated significantly only with urine Cd concentrations. No correlation was found with the integrated levels of Cd in the workplace air.They concluded that current urine Cd measurements can be used to predict the kidney and liver Cd concentrations. Comparison of data with more traditional measurements featured also in a study by Gerhardsson et al.99 of in-vivo XRF measurement of Cd in kidney and Pb in bone for 22 smelter workers. O'Meara et al.100 examined the possibility of in-vivo XRF measurement of U in bone. A 57Co source (1 mCi) was used The LOD found was 20 mg g-1, which they concluded was with 180° backscatter geometry and a hyperpure Ge detector.not suYcient for use in occupational monitoring. Apart from in-vivo techniques, measurement of previous Pb exposure can be obtained by measurement of Pb in shed teeth or in bones post-mortem. Lead in shed teeth measured by k-shell XRF was compared in children from Beijing, industrial sites in the Urals and urban USA in a study by Bloch et al.101 Calibration was by aqueous solutions of Pb and the signal response of Pb in teeth was divided by two to account for the diVerence in density between teeth and the standard solutions.Bone samples from a late 19th century graveyard in Colorado, USA, analysed for several elements by XRF and ICP-AES, showed Pb concentrations comparable to those found in modern Pb smelter workers.102 In order to overcome the high dead time associated with a high matrix interference in the determination of trace elements in blood plasma by TXRF, Savage and Haswell103 examined the use of chemical modifiers in drying and ashing the sample in order to prevent losses of volatile elements and to modify the matrix.Despite the addition of Ni and Mg nitrates, losses of As and Se were found when using microwave ashing but dead time was reduced to about 20%. However, since microwave ashing took about 20 min, it was more practical to accept a higher dead time (and consequently longer measurement) with simple air drying.The use of Mg(NO3)2 together with APDC was found to be beneficial in improving precision by ensuring even dispersion of the sample on drying. Impressive results were obtained on 16 elements in the Versieck second generation CRM and in a range of samples from the Trace Elements Quality Assurance Scheme, Guildford, UK. Sample volume was only 10 ml and precision was generally better than 8% RSD. Normal concentrations of bromide in human blood were determined by Olszowy et al.104 on 183 random blood samples by WDXRF. Two samples from each donor were mixed to give 16 ml (!) which were put into an Al sample cup to give a depth of 20 mm for irradiation.A range of 2.5-11.7 mg l-1 was found (mean±s: 5.3±1.4 mg l-1). Zaichick105 compared three methods for estimating extracellular water by determination of the corrected bromine space using stable Br and EDXRF measurement of Br in blood, urine and saliva.All approaches gave results which were in agreement with those obtained by use of a conventional 82Br measurement. Fukumoto et al.106 described applications of a newly developed XRF system for element mapping with a spatial resolution of better than 20 mm. Examination of a sliced tissue sample taken at autopsy from a patient with brain calcification revealed high concentrations of Ca, Fe and P on the internal surfaces on capillary vessels.Improvement in data handling enabled Brands et al.107 to produce an element map of 1024 pixels in less than 1 min and thus allowed continuous updating of the map. Imaging of Hg in hair108 and kidney109 using SRXRF enabled workers at the University of Tsukuba, Japan, to study the accumulation of Hg in rats. After endogenous exposure to methylmercury, Hg accumulated in the cortex of the hair while the predominant site after exogenous exposure was the cuticle.1.3.4 Other multielement techniques and studies. Simultaneous ETAAS and FAAS was used by Gottelt et al.110 to determine Cd, Cu, Fe, Mn, Ni, Pb and Zn in liver and kidney samples from cattle taken from 5 areas of Brandenburg, Germany. The data were analysed by multivariant techniques to define the origin of the sample. Data on reference values are always useful, particularly for children. Rukgauer et al.111 reported serum concentrations of Cu, Mn, Se and Zn, measured by ETAAS, for healthy children 20.4 mmol l-1, 25.5 nmol l-1, 0.77 mmol l-1 and 12.6 mmol l-1 in eight age groups. Overall mean concentrations were for Cu, Mn, Se and Zn, respectively.Concentrations of Cu, Fe and Zn in 157 broncho-alveolar lavages before and after centrifugation were measured by Harlyk et al.112 Zinc was measured by FAAS and Fe and Cu by ETAAS using standard additions calibration. Most of the trace elements were in the supernatant.An inverse relationship between Zn and Cu concentrations was apparent. Centeno et al.113 measured essential and toxic trace element levels in human placental tissues by FAAS and ETAAS after microwave digestion. Reference values were established. Some data on Cu concentrations from pregnancies at risk for Menkes disease showed higher values in parenchyma and membrane than those for controls. Values for trace elements in the lung lobes of Japanese urban dwellers were established by Tsuchiyama et al.114 using FAAS and ETAAS.Copper and Zn concentrations showed a smaller inter-individual variation and were not apparently aVected by smoking or occupational exposure. The elements Al, Cd, Cr, Mn, Ni and Pb showed much larger inter-individual variation and were aVected by environmental or occupational exposure. Concentrations of Cd, Cr, Ni and Pb were associated with smoking and exposure to metal-containing dusts at work gave higher concentrations of Al, Cr, Mn and Ni.In a study of Blackfoot disease (a vascular disorder resulting in gangrene of the foot), Horng and Lin115 found concentrations of As, Hg and Pb in urine that were significantly higher than in controls and concentrations of Se and Zn that were lower. Mercury and As were determined by continuous flow CVAAS and HGAAS, Pb and Se by ETAAS and Zn by FAAS. 1.4 Developments in single element techniques Tungsten-coil atomizers are small, relatively low in cost and use low power.They have been used to their best advantage in a portable analyser for Pb in blood developed by workers at Wake Forest University, USA.116 This, powered by a 12 V car battery, used a conventional Pb HCL as the source and a CCD array detector mounted in a laptop computer. Background correction was by near-line correction at the nonabsorbing 280 nm line and the atomizer was purged with 10% H2 in Ar to prevent oxidation.The application of this device Cd in aqueous solution was 3 mg l-1. Precision was about 10% to determine Cd in urine has been published.117 The LOD for RSD. The same group investigated the potential of the W-coil atomizer for ETV-ICP-AES, using the same inexpensive CCD detector for measuring the emission from the plasma.118 The LODs were comparable to those obtained with conventional ETAAS but the advantage was the ability to measure several elements simultaneously.A parallel development119 has been a system for multi-element ETAAS using four EDLs or HCLs and three 45° coarse grating beam combiners. The instrument had been used to measure Cd, Cr, Cu and Pb. Further details of these systems are awaited with interest. In their application 723 J. Anal. At. Spectrom., 1999, 14, 717-7813. Precision was improved by using an alignment by ICP-MS, were statistically equivalent to the best-estimate of the W-coil atomizer, Parsons et al.120 diluted blood samples reliable based on the agreement of two or more laboratories.1+4 with a modifier containing NH4H2PO4, Triton X-100 The atomic abundances of 208Pb, 207Pb and 206Pb, determined and HNO device to guide the micropipette into the atomizer for injection. It was possible to achieve an LOD of 10-20 mg l-1 and results TIMS values. The preparation of serum materials for interlaboratory comparison of selenium measurement was described on blood RMs were encouraging.In an investigation of by Morisi et al.133 Bovine serum was spiked with H SeO3 to chemical modifiers for the determination of Pb in digests of give five pools of serum with Se in the range 26-1202 mg l-1. blood and hair with the W-coil atomizer, Bruhn et al.121 found Unspiked materials suitable for speciation studies were prethat, of NH4H2PO4, (NH4)2HPO4 and Pd, the best accuracy pared by mixing bovine and horse serum with Se concenand precision was obtained with Pd.Sensitivity was improved trations of 25 and 150 mg l-1, respectively. by including a cooldown step prior to atomization. Results on hair and blood CRMs gave results in agreement with the 1.6 Hair and nail analysis certified values. The mean precision was 5.0% RSD and the LOD was 1 mg l-1. For Cd122 and Cr,123 the best modifier was again Pd, which eliminated chemical interferences, reduced the background and increased the lifetime of the tube by 20% in the case of Cd determination.An LOD of 0.05 mg l-1 was found for Cd. Kitigawa et al.124 have modified their vertical column atomizer to allow temperatures above 2400 °C to be maintained. The modifications were: the use of an open column of glassy C rather than a packed column; suspension of the sample cup with a glassy C rod rather than a W wire; a lower graphite electrode assembly to protect the glassy C column when expanding; and the use of a Si controlled rectifier to give higher power outputs.As in previous designs, determination could be made free of background and this was illustrated by the determination of Mn in a bovine liver CRM. The simplicity and reliability of the flame atomizer have encouraged many to explore ways of increasing its sensitivity. The intriguing combination of ETV with FAAS was investigated by Yoo et al.125 A Ta-filament atomizer was used to introduce 10 ml of blood or urine into a flame for the determination of Al, Ca, Cd, K, Na, Pb and Zn.Publication of results by this technique will be of particular interest. Liang and Lin126 used a slotted quartz tube to increase the sensitivity for the determination of Pb in herbal medicines by FAAS. Presputtering the tube with a solution of vanadate produced an orange-red coating and prevented the deposition of sodium salts and C on the surface of the tube, thus prolonging its lifetime.The high sensitivity achievable by laser-excited atomic fluorescence spectrometry with electrothermal atomization has been exploited by Winefordner's group to measure Ge127 and Pt128 in biological samples. A dye laser pumped by a Cu vapour laser gave excitation at 269.13 nm for Ge and 270.24 nm for Pt. The LODs were 1.1 pg for Ge and 50 fg for Pt. For Pt,127 wall atomization was preferred to platform atomization as black body radiation from the platform aVected the reproducibility of the results.Despite a high dilution of blood (1+24) with H2O, interferences were still present and standard additions calibration had to be used, whereas for urine, a dilution of 1+4 removed interferences, allowing calibration with aqueous standards. 1.5 Reference materials and quality assurance An overview by Byrialsen et al.129 of trends in quality assurance in the determination of metals in clinical samples highlighted the introduction of the concepts of traceability and uncertainty.Haraguchi et al.130 reported on an interlaboratory comparison of results in the determination of 11 elements in human plasma. Of these elements, most variation was seen in the results obtained for Se by various techniques. The trace element concentrations and Pb isotope composition in NIST SRM 1400 Bone Ash were measured by quadrupole and magnetic sector ICP-MS (4 laboratories) and TIMS (2 laboratories) in a study reported by Hinners et al.131,132 Results for 42 analytes were listed, 26 of which were considered to be 724 J.Anal. At. Spectrom., 1999, 14, 717-781 Kruse-Jarres134 has stressed the limitations of hair analysis, indicating that hair acts as a kind of ion-exchanger with small superficial holes and fissures operating as ports of entry. Thus hair contains elements both of exogenous and endogenous origin, which cannot be diVerentiated by prior sample pretreatment.Imprecision in determination of hair samples of nearly identical origin is 30% or more. He concludes that hair analysis is unsuitable for the detection of clinically relevant deficiencies of essential trace elements and only has a limited role in assessment of exposure to heavy metals. Evidence for this can be seen in the study by Ali et al.135 on hair levels of Ca, Cr, Cu, Fe, Mn, Ni, Pb and Zn in malnourished and healthy children in Bangladesh.Despite the lack of nourishment, concentrations in the hair of those children showed no significant diVerence from the results for the healthy children. Measurements were made by PIXE after grinding the hair and forming a pellet. However, there are always reports of positive findings from studies involving hair analysis for the essential elements. Hussein et al.136 reported that hair Zn concentrations in Egyptian pre-school children corresponded to the children's growth rate, nutritional and socio-economic status.The average dietary intake of Zn was 3.8 and 3.6 mg for boys and below 70 mg g-1, their normal cut-oV value. For men with girls, respectively, and 13% of the children had a hair Zn alopecia, Jin et al.137 found hair Mn and Zn concentrations lower than those for healthy men but Cu concentrations were higher. Both of the latter two studies used FAAS for measurement. In an analysis of data on hair, sweat and serum Cr concentrations measured by ETAAS in their laboratory from 40 872 patients over the years, Davies et al.138 found that these measurements were significantly inversely related to age and that hair, sweat and serum measurements correlated well with each other.This apparent decrease in Cr status with age was discussed in terms of increased incidence of diabetes mellitus and heart disease with age. In a study of 13 members of the Italian expedition to the Antarctica, Caroli et al.139 measured, by ICP-AES, concentrations of Ca, Cu, Fe, Mg and Zn in hair samples taken before departure and on return.While Ca 21.7 mg g-1 before to 11.9 mg g-1 after. Increases were seen and Fe showed no changes, Mg dropped from a mean of for Cu (13.6-16.2 mg g-1) and Zn (174-217 mg g-1). The authors concluded that the changes were a result of stress, irritability and anxiety and could be corrected for by a change of diet. In view of the comments by Kruse-Jarres (see above), the wisdom of recommending diet changes based only on changes in hair concentration seems questionable. The relatively high Sb concentrations in the hair of infants, which appeared to support a hypothesis that sudden infant death syndrome (or 'cot death') was a result of SbH3 generated by bacteria from Sb in fire-retardants in mattresses, is discussed with other investigations in section 1.9.2.Yun and Li140 described their work in establishing values for the rare earth elements in the Chinese CRM, GBW09101 Human Hair, by ICP-MS.Dry ashing and microwave digestion were shown to be suitable methods for sample preparation.The results of analysis of vegetable CRMs and spiked samples showed accuracy which was confirmed by comparison with data from other laboratories. The concentrations found were generally more than 10 times the LOQ of the method. Further results have appeared from the ongoing Seychelles study of prenatal methylmercury exposure from a high fish hair mercury concentrations of the mothers was 5.8 mg g-1 diet on developmental milestones in children.141 The median measured by AAS.No association was found between the ages at which the children walked and talked and the mother's hair Hg concentration. High hair Hg concentrations were also found in a study of mothers and infants from the Amazon basin, Brazil.142 Total mercury was determined by CVAAS after alkaline digestion.The median hair Hg concentration was 14.1 mg g-1 in non-Indian mothers and 8.30 mg g-1 in Indian mothers. A statistically significant correlation between mother's and her infant's hair was only found for non-Indians, whereas a correlation between length of breast feeding and the infant's hair Hg concentration was only significant for Indians. 1.7 Drugs and pharmaceuticals Identification of the source of drugs by their trace element fingerprint is not a new idea, but the use of laser-ablation ICP-MS to provide this information is novel.Watling61 showed that this oVered a quick, convenient and relatively contamination-free method.Ground cannabis was pressed into a pellet and irradiated with an Nd5YAG laser. Ratios between the signals from the elements obviated the variability between diVerent ablation events and were conveniently presented as ternary ratio per cent discriminant diagrams expressing the relationship between three particular elements.The technique had been used to identify the source of cannabis in Australia from the relationship of the element patterns to the geological environment. Indirect methods of determination of pharmaceuticals through complexing with metal ions continue to be developed. Issa and Mohamed143 determined antazoline, hydralazine, amiloride and thiamine hydrochlorides and quinine sulfate after formation of insoluble ion-association complexes with [Cd(SCN)4]2- or [Zn(SCN)4]2-.The excess Cd or Zn was determined by FAAS or DCP-AES. El-Brashy and Al-Ghannam144 used the reaction with FeII or HgII to determine histidine by FAAS. A method for the determination of cinnarazine in pharmaceutical preparations by FAAS after com- 4]2- was shown by Hassan et al.145 plexation with [Co(SCN) to give results in good agreement with results obtained by molecular spectrophotometry and potentiometry.Interferences in the determination of Bi in prescription medicines by HGAAS were successfully overcome by masking with a solution of thiourea (0.2% m/v) and KI (10% m/v) in a method developed by Cadore et al.146 The same method could be used for determination of Bi in urine to follow the kinetics of excretion of Bi. The mineral composition (Ca, Cr, Mg, Mn and Zn) of 3 multi-vitamin and mineral tablets was determined by ICPAES after microwave digestion by Krampitz and Barnes.147 When open-vessel digestion with HNO -HCl was used, low results were obtained.New regulations in California, USA, require Pb exposure to be limited to 0.5 mg per day. High intake of Ca supplements taken, for example, for osteoporosis can result in this being exceeded and, as a consequence, there has been interest in measuring Pb concentrations in Ca supplements. As an LOD of below 0.5 mg g-1 has been stipulated, ICP-MS has been the method of choice.148-150 Sharma et al.150 used high pressure digestion with HNO3, while Bakowska149 found it suYcient to dissolve the pills (calcium carbonate or calcium chelates) in 3 concentrated HNO and then dilute with de-ionized water.Highest Pb concentrations (8-28 mg g-1) were found in supplements from natural sources (dolomite or bone meal ).150 Isotope ratios were also explored as a way of identifying the source of the product.1.8 Marine and freshwater biology 4 Moreton and Delves151 found that in the presence of NH4OH and (NH4)2H2EDTA, wash-out times in the determination of mercury by ICP-MS with conventional nebulization were reduced to less than 3 min. Applying this to the determination of Hg in fish, they digested fish tissue with HNO3 at room temperature for 24 h. The digests were made alkaline by careful addition of 6 M NH4OH and then diluted further with NH OH-(NH4)2H2EDTA solution.Levels of Hg in fish from the Tapagos valley, Brazil, were in the range 0.009-2.58 mg kg-1 (wet mass), and from this and from results on blood and urine Hg concentrations of the inhabitants, it was concluded that the levels of Hg in fish were a more general health problem than just for the gold miners who were directly involved in the use of Hg. Total Hg could be determined by FI-CVAAS at a rate of 100 measurements h-1 with a method developed by Tao et al.16 Samples were digested with TMAH for 30 min. Organic Hg was converted to inorganic Hg by 0.1 mg l-1.The method was validated on marine biological addition of 0.2% KMnO4 in the FI system. The LOD was CRMs. Organic Hg in fish was determined by Scerbo and Barghigiani152 after extraction with toluene. The Hg in the extract was back-extracted with cysteine solution and the Hg determined on an automatic Hg analyser, the AMA 254, which uses controlled pyrolysis and amalgamation to collect Hg for subsequent determination by AAS.More complete information is obtained by a GC separation technique, as demonstrated by Gerbersmann et al.153 They used a rapid microwaveassisted dissolution technique with TMAH. Two approaches were then used for analysis by GC-AES. In the first, derivatives formed by ethylation with sodium tetraethylborate were extracted into hexane and injected into a cooled injection system.In the second, hydrides were generated with NaBH4 and introduced with a purge-and-trap injector. Both CRM but the former gave the lower LOD (3.0 pg g-1 versus approaches gave satisfactory results on a freeze-dried tuna 12.5 pg g-1). Haraguchi's review in Japanese154 covers methods for the 4 determination of organotins in environmental and biological samples and deals with the eVects on the human endocrine system of consumption of food contaminated with these compounds.Rapid one-step extraction and derivatization of organotins from fish tissue was developed by Schmitt et al.155 In this, 0.1-0.2 g of tissue was microwaved at 40W power with acetic acid, nonane and NaBH solution for 3 min. The organic phase was analysed by GC-AES after cleanup on an alumina column. The method, validated on a fish tissue CRM, was applied to the analysis of mussels and sea-urchin eggs. Abnormal arsenic concentrations were found in fish from 4 3 Lake Usonko, a naturally acidified lake in Japan, by Takatsu and Uchiumi.156 The fish tissues were digested with HNO -HClO and the As determined by HG-ICP-AES. The accumulation of As, concentrated mainly in the eye tissues of the fish, was thought to be related to the high As and low P content of the lake water.Trace amounts of vanadyl porphyrin in marine mussels were determined by Rivaro and Frache157 using HPLC with ICP-AE and UV detection.It was possible to detect this compound in mussels accumulating high concentrations of V from their environment. A method for the determination of Cd in mussels was developed by Enriquez-Dominguez et al.158 After microwave digestion with HNO3, the Cd was collected at pH 4.5 725 J. Anal. At. Spectrom., 1999, 14, 717-781on a column of poly(aminophosphonic acid) resin in an FI system. Elution with 0.5 M HCl into a flame AA spectrometer allowed the determination of Cd down to an LOD of 0.56 mg l-1.Forty samples h-1 could be analysed in this way. The preparation and certification of Plaice and Shrimp RMs by the National Food Agency, Denmark, was described by Larsen et al.159 Total trace elements were determined by ETAAS, CVAAS, ICP-MS and ID-ICP-MS. Certified values were established for As, Cd and Hg in the Shrimp RM and As, Hg and Se in the Plaice RM. Indicative values for arsenobetaine amd tetramethylarsonium ion were found by cation-exchange HPLC coupled to ICP-MS as detector. The eVects of pollution from a disused Ni mine and smelter on fish in the river Otra, South Norway, were investigated by Brotheridge et al.160 The liver and muscle of brown trout, sampled from several sites along the river, were digested with HNO3 and Co, Cu, Ni and Zn determined by AAS and/or AES. Concentrations were highest nearest the mine and gradually decreased down river.1.9 Progress for individual elements 1.9.1 Aluminium.Several diVerent approaches have been The use of AMS for measurement of 26Al in biological samples continues to be well represented. King et al.89 described sample preparation methods for the determination of 26Al in a variety of clinical samples by AMS. Following addition of 27Al carrier, blood and soft tissues were acid digested and Al selectively extracted with quinolin-8-ol. The complex was ignited in air to form Al2O3.Urine Al was precipitated with phosphate, extracted with acetylacetone and back extracted into HNO for ignition with air to form Al The method gave an absolute 3 LOD of 10-18 g. Kislinger 2O3. et al.84 studied Al biokinetics in renal failure patients by AMS, following administration of a 26Al tracer, and developed a pharmacokinetic model to describe the experimental data. They observed that Al was mainly excreted from plasma citrate into urine and from plasma transferrin into faeces via the liver.They also noted that the size of two peripheral Al compartments were diVerent in renal failure patients compared with controls. Barker and colleagues88 used AMS to study the 4, followed by solid phase extrac- role of transferrin in Al uptake and distribution in hypo- 3 taken to overcome matrix interference on the determination of Al in serum by ETAAS. Chen et al.161 used microwave digestion with HNO -HClO tion with 1% quinolin-8-ol on an XAD chromatographic transferrinaemic mice and mice treated with antibodies to the column.The bound AlIII was eluted with 1 M HCl and determined by ETAAS. An LOD of 0.3 mg l-1 could be achieved if transferrin receptor. They observed that non-transferrin mediated Al transport occurred in many tissues and concluded careful attention was paid to determination of the analytical that transport by citrate and low molecular mass complexes blank.Bu and Sun162 used a molybdenum coated tube and a may be important. Uptake of Al was greatest in bone and K2Cr2O7-Triton X-100 chemical modifier for the direct deter- least in spleen and brain. Yumoto et al.87 used AMS to mination of Al in serum of cancer patients. An absolute LOD of 21 pg was reported. The graphite tube was pre-coated by injection and atomization of 50 ml of a 10% ammonium molybdate solution. A sample deproteinization procedure by microwave digestion with 1% TCA was described by Bohrer et al.8 Low acid concentrations produced complete protein reduction with minimal dilution (1+1 v/v).The deproteinization method gave results in good agreement with a direct Kisters et al.166 used AAS to determine Al levels in lymphodilution method, but sample deproteinization allowed a simpler and faster temperature programme to be used without matrix interferences. Burden et al.9 investigated optimum collection and sample preparation procedures for the determination of Al and other trace elements in urine samples by ICP-AES.They noted that precipitated salts could contain Al and, therefore, these were redissolved for accurate quantitation of Al. Satisfactory results were obtained by standard additions or matrix matched calibration but aqueous calibration was inappropriate. Muniz and colleagues71 described a comprehensive evaluation of ICP-MS and ETAAS methods for the determination of Al in serum.They obtained better LODs with HR-ICP-MS (0.35 mg l-1) and Q-ICP-MS (0.85 mg l-1) compared with ETAAS (2 mg l-1). Matrix eVects were overcome by simple dilution (1+4 v/v) with H2O for Q-ICP-MS, but were still evident at a 1+9 dilution with the high resolution instrument. These were corrected for with Be and Sc internal standards. Analysis of serum samples from healthy subjects showed that HR-ICP-MS was necessary for the determination of Al levels as they were at or below the LOD of 0.35 mg l-1.The same research group163 also coupled FPLC with HR-ICP-MS to study the speciation of Al in human serum from unexposed individuals and uremic patients. Serum proteins were separated by anion exchange chromatography with a CH3COONH4 gradient at pH 7.4. The results indicated that transferrin was the only significant Al binding protein in uremic serum. The combination of HPLC with oV-line ETAAS was used by Roellin et al.164,165 to study Al binding to serum proteins.726 J. Anal. At. Spectrom., 1999, 14, 717-781 Serum was ultrafiltered and chromatographed by diVerent size exclusion techniques, using a phosphate-NaCl mobile phase. Both high and low molecular mass complexes were identified. The authors applied the method to the analysis of serum from occupationally exposed workers and observed that increased Al exposure was associated with an increase in the high molecular mass fraction.investigate Al uptake and accumulation in rat brains, five days following injection of 26Al. A considerable amount was measured in the brain and the levels remained constant for over 270 d. Blood Al levels, however, fell significantly after 75 d. The authors considered the data supported the hypothesis of Al accumulation in the brain being a causative agent for Alzheimer's disease. cytes from dialysis patients. T lymphocytes were separated by rosetting with sheep red blood cells.Intracellular Al concentrations were increased in B lymphocytes of dialysis patients (2.92 versus 1.44 mg g-1 protein) but not in T lymphocytes (2.24 versus 2.18 mg g-1 protein). Golub et al.167 measured Al in tissues of guinea pig fetuses by ETAAS in a study examining the distribution of Al in the central nervous system during development. They noted that Al distribution did not follow that of essential cations.1.9.2 Antimony. A sensitive ETAAS method, using a transversely heated furnace with STPF conditions and longitudinal Zeeman eVect background correction, was presented by of mg l-1 levels of Sb in tap water, serum and whole blood. Subramanian et al.168 for the quantitative determination The use of a Pd-Mg(NO3)2 chemical modifier eliminated the need for standard additions calibration and an LOD of 2.6 mg l-1 was reported. The method was evaluated by analysis of leachate tap water from plumbing systems containing Sn-Sb soldering and determination of Sb in blood samples taken from rats given Sb supplemented drinking water.A coupled HPLC-ICP-MS method was described by Koch et al.169 for the determination of Sb species in biological samples. Both ion exchange and ion pairing techniques were used to separate SbIV, SbV, trimethylantimony dichloride and phenylstibonic acid. The hypothesis that sudden infant death syndrome ('cot death') was a result of SbH3 generated by bacteria from Sb in fire retardants in mattresses was supposedly supported by high hair Sb levels.This hypothesis, publicized3-H2O2. The low LODs for connected to a quartz cell in an air-C2H2 flame. Limits of by a British TV programme 'The Cook Report' led to an extensive investigation by an expert committee appointed by the UK Government. In a large scale study, commissioned by the committee and reported by Keenan et al.,170 the concentrations of Sb in umbilical cord and matched infant hair samples were determined by HG-AFS, following closed vessel microwave digestion with HNO the methods (1 ng g-1 for cord and 3 ng g-1 for hair) enabled Sb to be quantified in 90% of both sample types.Mean and median Sb values of 27.7 and 9 ng g-1 were determined in cord blood whilst for hair the mean and median values were 826 and 300 ng g-1, respectively. Concentration distributions were heavily skewed in both sample types.The investigators found no correlation between cord Sb and hair Sb in matched samples. They considered the likely origin of the Sb to be environmental via food, airborne dust and water. 1.9.3 Arsenic. There has been a wealth of publications on 2 to the nebulizer gas flow or the addition of ethanol to were determined by HPLC-ICP-MS, using an anion exchange the determination of As in biological materials in this review period.Although it is recognized that As speciation is very important for monitoring occupational and environmental exposure, methods for the determination of total As continue to be reported. Pozeban et al.64 found Ir to be a suitable chemical modifier for the determination of As, Se and Pb in urine by ETV-ICP-MS, allowing pyrolysis temperatures up to 1300 °C. The modifier was injected and atomized before the sample to form an Ir coating, as this removed contamination from the modifier and lowered blank signals.Amarasiriwardena et al.171 compared diVerent interference correction methods for the determination of As in urine by solution nebulization ICP-MS. The authors claimed that accurate determination of As could be achieved by the addition of 3% N the samples, using Te as an internal standard. The methods were evaluated by analysis of NIST SRM 2670 (toxic elements in urine). The majority of clinical studies, however, have described methods for the speciation of As in order to distinguish metabolites of inorganic As from less toxic dietary forms.Benramdane et al.172 selectively extracted toxic As species from dietary As prior to analysis by ETAAS. Optimum extraction was achieved by reduction with KI-Na hypophosphite to form 'iodide arsines', which were extracted into toluene and back extracted into NaOH. Recoveries of 100% were reported with an LOQ of 7 mg l-1.Guo et al.173 observed low recoveries of toxicologically relevant As species in urine when KI-ascorbic acid was used as a pre-reductant for FI-HGAAS. They obtained optimum recoveries for AsIII, AsV, dimethylarsinic acid (DMA) and monomethyarsonic acid 4 (MMA) following reaction of diluted urine with 1% cysteine in 0.03 M-1 HCl. A high NaBH concentration (0.5%) and longer residence times in the HG system eliminated residual kinetic eVects in the formation of hydrides from the diVerent As species.Sperling et al.25,174 examined in depth diVerent chromatographic and HG conditions for the determination of As species 1.9.4 Bismuth. A HGAAS method for the determination of in urine by HPLC-HGAAS. The influence of stationary and Bi in plasma was developed by Shen et al.183 to monitor mobile phases, conditions for complexation and design of gas- plasma Bi concentrations in a patient administered a Bi liquid separator were evaluated.The authors found that containing anti-ulcer compound. Heparinized plasma was optimum separation was achieved on a strong anion exchange digested with HNO -HClO4, evaporated to near dryness and column with a phosphate buVer. On line photo-oxidation with redissolved in HCl for hydride generation. Standard additions K2S2O8-NaOH oxidized all As species to AsV for HG. calibration was used for quantitation and the LOD was Burguera et al.24 described an on-line FI-HGAAS method for 1 mg l-1.The authors compared the HG method with an the separation and determination of AsIII, AsV, DMA and extraction method and obtained comparable results but with MMA in urine from occupationally exposed workers. improved analytical precision. Cadore and colleagues146 also Separation was achieved on a combined anion-cation described a HGAAS method for the determination of Bi in exchange column. Arsenite was not retained on the column both urine and prescription medicines.In their approach and MMA, AsV and DMA were eluted with 0.006 M TCA, samples were acid digested and potential interferences from 0.2 M TCA and 5 M NH4OH, respectively. The eluted fractions metal ions were overcome by the addition of a thiourea-KI were reacted with 15% KI-5% ascorbic acid and 1% NaBH4. Ng and colleagues175 developed an HGAAS method with cold trapping for the determination of As metabolites in urine from exposed workers.The hydride trapping system consisted of two water traps and a chromatographic column of 10% polyphenyl ether on 100-200 mesh Chromosorb, and was detection for the species were 1, 1.3 and 3 ng for AsIII+AsV, DMA and MMA, respectively. The authors observed an increased excretion of AsIII+AsV in exposed workers and hypothesized that methylation of inorganic As was compromised. Ma et al.176,177 described a fast HPLC method for separating As species in urine with detection by HGAFS.Fast separation was achieved by ion-pair chromatography on a short column, giving baseline separation of four As species in minutes. The method was validated by analysis of CRMs and was used to study the eVect of dietary As intake on urinary As excretion. The authors found that arsenosugars in seaweed were metabolized to DMA. Speciation methods have been applied to studies of As metabolism in various study populations. Zhang et al.178 measured As species in serum from groups of uraemic patients.Low molecular weight species were quantified by ion exchange chromatography-HGAAS, whilst high molecular weight species were separated by SEC or aYnity chromatography, digested and quantified oV-line by HGAAS. All groups of uraemic patients had increased serum As levels compared with controls and the major As species were identified as DMA and arsenobetaine. Only inorganic As species were bound to proteins.Kavanagh and colleagues179 reported findings of a pilot study of urine As species in residents from a heavily As contaminated area of the United Kingdom. Arsenic species column with a phosphate mobile phase coupled to a high pressure nebulizer. They found an increased excretion of total As and an increase in the percentage of inorganic As, indicating chronic exposure to inorganic As. Del Razo et al.180 also found a significant increase in inorganic As species, with a corresponding decrease in methylated species, in the urine of adults chronically exposed to As in drinking water.The group used HPLC-HGAAS for determination of As species. They noted that individuals with cutaneous signs of arsenicism had significantly higher levels of MMA and inorganic As and hypothesized that chronic exposure to As led to a decrease in methylating capacity. Hsueh et al.181 determined As species in urine from exposed populations drinking As contaminated water, using HPLC-HGAAS.They observed that individuals a cumulative As exposure>20 mg l-1 year-1 had an increased with elevated proportions of MMA in their urine (>27%) and multivariate odds ratio of 20.9 for developing skin cancer. In a study of potential biomarkers for cardiovascular disease, Jensen et al.182 found increased levels of glycosylated Hb in As exposed workers which was associated with an increase in systolic blood pressure.3 727 J. Anal. At. Spectrom., 1999, 14, 717-781masking solution. Improved sensitivity and precision were achieved with a low residence volume gas-liquid separator, which was treated with HF and chlorodimethylsilane to eliminate reactive sites on the glass surface, giving an LOD of 0.3 mg l-1 and analytical precision of 4.7% RSD. 1.9.5 Boron. In a comprehensive review containing 175 references, Sah and Brown184 examined the advantages and disadvantages of diVerent analytical methods for the quantitative determination of B in biological samples.Whilst spectrophotometric methods, based on colorimetry or fluorimetry, were most commonly used, they were noted to suVer from numerous interferences and to have low analytical sensitivity and poor precision. Amongst nuclear methods, only alpha spectrometry was considered to be of practical use. The development of ICP-MS methods overcame many of the drawbacks of spectrophotometric methods and oVered the advantage of B isotope measurements for both biological tracer studies and isotope fingerprinting.The authors considered ICP-MS to be the method of choice for accurate B determination in biological matrices. A simple automated method, which the authors Anderson and Tschirgi185 described as benign-by-design, was developed for the determination of B in microsamples of biological tissue. The acid digestion of 100-400 mg tissue samples minimized waste and eliminated the need for toxic reagents previously used for B determinations. The method was exhaustively evaluated by more than 250 determinations of B in a variety of CRMs and recoveries between 82% and 104% were reported. Price et al.186 described a high temperature alkali ashing sample preparation procedure for the determination of B in whole blood by ICP-AES.The method was used to study blood B levels in pregnant rats administered B throughout gestation.The researchers observed that blood B was positively correlated with both maternal dietary B and with embryo/fetal toxicity. They reported a no observed adverse eVect level of 10 mg kg-1 d-1 for developmental toxicity. 1.9.6 Bromine. Using WD-XRF, Olszowy et al.187 determined a reference interval for bromide in human blood. Blood samples were dispensed to a depth of 20 mm into aluminium sample cups, with a Mylar film base, which were placed in the spectrometer for quantitation of Br.Correction for matrix diVerences between samples and aqueous calibration standards centration of 5.3 mg l-1 and a reference interval of was made using the Compton scatter line. A mean Br con- 2.5-11.7 mg l-1 was determined. The authors noted that blood Br levels tended to be higher in older people and women. Zaicheck105 used EDXRF to determine Br in diVerent body fluids in order to estimate the extracellular water space.Volunteers were given an oral dose of 14 mg kg-1 stable Br as an NaBr solution. Blood, urine and saliva samples were collected 6 h and 243 h after administration and the Br concentration determined by XRF, using a 109Cd source and 25 mm2 Si(Li) detector. The method gave results that were in good agreement with a conventional 82Br measurement method. 1.9.7 Cadmium. The eVectiveness of diVerent chemical modifiers for the determination of Cd in acid digested hair and blood samples by ETAAS, using a tungsten coil atomizer, was examined by Bruhn et al.122 Optimum performance was obtained with a Pd modifier, which both reduced background interferences and improved atomizer lifetime.Several groups have described diVerent sample introduction procedures for the quantitative determination of Cd in biological matrices by ICP-MS. Goenaga Infante and colleagues188 compared an FI-ICP-MS method with in-situ trapping ETAAS for the determination of Cd in urine at baseline levels.Both methods were based on the vesicle assisted HG procedure 728 J. Anal. At. Spectrom., 1999, 14, 717-781 3 previously described by this group.189 Simple dilution 1+1 v/v with H2O minimized contamination risks. Aqueous calibration gave satisfactory results and the use of an antifoam agent for HG enabled a throughput of 20 h-1 for the FI-ICP-MS method. Absolute limits of detection were 7 pg and 14 pg for ICP-MS and ETAAS, respectively, and both methods were validated by analysis of a urine CRM. In the study described by de Boer et al.190 for the direct determination of Cd in urine by ICP-MS, various approaches to overcome or correct for matrix interferences were investigated.The eVect of nonspectral interferences from NaCl were corrected for by internal standardization with Rh and the use of a correction equation, calculated from a series of recovery experiments. Sample dilution 1+9 v/v with 1% HNO and measurement at the 114Cd mass were found to give satisfactory results for CRMs.A particularly sensitive FAAS method for the determination3 of urine Cd species separated by HPLC was described by Chang et al.191 A novel thermospray nebulizer design produced a 104 fold improvement in sensitivity over conventional flame nebulization. An LOD of 3-7 ng l-1 was reported for a 100 ml urine sample chromatographed on a 5 cm C8 column, using 2O as the mobile phase at a flow rate of 2.5 ml min-1. Lee Het al.67 developed an ETV-ID-ICP-MS method for the direct determination of both Cd and Pb in urine.A 1% HNO solution was used as a chemical modifier and a low vaporization temperature of 1000 °C employed to separate the analytes from matrix components. Isotope ratios were calculated from peak area measurements of each isotope. The ID method was evaluated by analysis of NIST SRM 2670, freeze dried urine, and comparison with standard additions calibration.Detection limits of 0.02 mg l-1 and 0.005 mg l-1 were reported for Cd and Pb, respectively. In an eVort to better understand the bioavailability of dietary Cd, Langford et al.192,193 developed a coupled SEC-ICP-MS method to characterize Cd species in human ileostomy fluid. Ileostomy patients were given a porridge meal spiked with 106Cd and ileostomy fluid collections were made at various times over a 24 h period.The samples were ultracentrifuged and separated by SEC with ICP-MS detection of the 106Cd and 111Cd isotopes together with Cu, Pb and Zn. Both Cd isotopes eluted in a single peak corresponding to a molecular weight of 15 kDa. The Cd peak was also associated with Zn but not Cu or Pb. The portable battery powered tungsten coil AA spectrometer described in the previous Clinical update6 was used by However, the reported LOD of 3 mg l-1 is considered by this Batchelor et al.194 to determine Cd in urine, soil and tap water.reviewer to be insuYciently sensitive to monitor low-level currently reported to be well below 1 mg l-1. A detailed environmental exposure as 'normal' levels of Cd in urine are investigation of Cd exposures in battery workers was reported by Boerjesson et al.98 in which in-vivo measurements of liver and kidney Cd by XRF were compared with Cd in blood and urine and cumulative air Cd measurements. Several correlations were observed, most notably, kidney Cd with urine Cd (r=0.70), liver Cd with urine Cd (r=0.58) and kidney Cd with blood Cd (r=0.49). No correlation between cumulative air Cd exposure and kidney or liver Cd were observed.The authors considered that uncertainties in both the estimates of individual cumulative exposures and in the in-vivo measurements may have contributed to the lack of correlation. Finally, an ETAAS method was developed by Bermejo- Barrera et al.195 for the determination of ultra-trace levels of Cd in cocaine and heroin samples.A 0.2% (NH4)2HPO4 was found to be the optimum chemical modifier and standard additions calibration was necessary to overcome matrix interferences. Cadmium levels in cocaine ranged from 5-45.6 mg kg-1 and in heroin ranged from 10-192 mg kg-1. The authors considered the measurement of Cd in both drugsto be one of several parameters which could help elucidate the geographical provenance of the illicit drugs. 1.9.8 Calcium.The high sensitivity of AMS to 41Ca was used by Freeman et al.90 to study the kinetics of Ca in the human. The authors considered that a 41Ca tracer could be administered to achieve a quasi-steady-state situation, and thus bone resorption could be quantitatively measured directly. They tested the hypothesis by comparison with a conventional stable isotope study and obtained good agreement between the methods.To study the role of Ca in the pathogenesis of pre-eclampsia, Kisters et al.196 determined plasma and erythrocyte membrane Ca levels in healthy pregnant and pre-eclamptic women by AAS. A decrease in plasma Ca levels (1.98 versus 2.43 mM) and corresponding increase in membrane Ca content (1.21 versus 0.73 mM) was found in pre-eclamptic women, from which the authors concluded that the condition was associated with a disturbed Ca homeostasis.1.9.9 Chromium. The quantitative determination of Cr in biological matrices by ICP-MS is aVected by interferences on the most abundant isotope 52Cr by the polyatomic species 40Ar12C and 35Cl16OH and interference from 54Fe on 53Cr and 54Cr. The severity of these interferences normally precludes the determination of Cr in blood and urine by ICP-MS, using conventional pneumatic nebulization. In the method described by Gupta and Barnes,197 sample introduction by ETV was used to minimize interferences from the organic matrix.Replacement of the graphite furnace with a tungsten filament removed the interference from 40Ar12C. In a second paper, the same research group51 described a high pressure vapour phase acid digestion procedure, using specially designed microvessels, for the determination of Cr and V in biological matrices by ICP-MS with pneumatic nebulization. The digestion procedure markedly reduced C and Cl polyatomic interferences and the remaining 40Ar12C interference on 52Cr was corrected mathematically. The method was verified by analysis of biological SRMs.Chromium in biological samples is normally determined by ETAAS. With great improvements in ETAAS instrumentation and the recognition and elimination of contamination sources over past decades, the levels of Cr determined in healthy populations have declined markedly. In a recent survey of the Italian population, Apostoli et al.198 reported a reference value of Cr in urine of 0.08 mg l-1 (non-detected-0.24 mg l-1).Measurements were made at three laboratories using similar methodologies and a between laboratory standard deviation of 0.049 mg l-1 was reported. Using multiple regression analysis to study confounding factors, only geographic location and gender were found to have any influence on urine Cr levels. Interestingly, populations residing at coastal locations had the lowest levels.Davies et al.138 reported age related decreases in hair, sweat and serum Cr levels in a study of over 40 000 patients, using ETAAS to determine Cr in all sample matrices. Correlations were found between hair Cr, sweat Cr and serum Cr, leading the authors to consider both hair and sweat to be suitable additional matrices for assessing Cr status. The authors discussed the implication of the age-related decline in Cr on the development of several age-related diseases.In a review of TOF-LMMS, Hachimi et al.199 critically evaluated the potential of the technique for the speciation of Cr and Ni in biological specimens, such as macrophages. 1.9.10 Cobalt. A novel crossed immunoelectrophoresis-LAICP-MS method was developed by Neilsen et al.58 for the identification and quantitation of Co binding proteins in human serum. Serum, enriched with Co, was electrophoresed in two dimensions on an agarose gel.Cobalt associated with proteins was quantified in the gel by LA-ICP-MS and the main binding proteins identified by comparison with Coomassie Blue stained gels. The main Co binding proteins were identified as albumin, a-2 macroglobulin, a-1 and b-1 lipoproteins and haptoglobin. Owing to present limitations in the sensitivity, the authors considered the technique to be most appropriate for clinical studies of metallodrugs containing Au and Pt.1.9.11 Copper and zinc. Two groups evaluated methods to minimize matrix interferences on the determination of Cu and Zn in biological fluids by ICP-MS. Szpunar et al.56 compared cross-flow and FI-direct injection nebulization for introduction of serum and urine samples diluted with 0.05% HNO3. Results obtained for CRMs agreed well with the certified values. In the study by Hsiung et al.49 simple dilution and calibration with an internal standard was found to be satisfactory to minimize polyatomic interferences on the determination of Cu and Zn in urine and serum. Accurate results for CRMs were obtained with measurements of 65Cu and 68Zn isotopes.Kondo et al.200 described a TXRF method for the quantitative determination of Cu and Zn in small (mg) biopsies of bladder cancer tissue. Measurements were made using 11 keV X-rays and calibration was by standard additions. Levels of Cu were significantly lower in carcinoma tissue compared with healthy tissue, whereas Zn levels remained relatively unchanged.The authors concluded the method was suYciently sensitive to monitor time-dependent changes in trace element levels in developing carcinomas. A computer controlled electrodialysis unit was designed by Jacobus et al.201 and coupled to an FI-AAS system for the determination of Cu in multi-vitamin and mineral tablets. The dialysis unit separated and preconcentrated soluble CuII ions from tablet suspensions with an eYciency of 94%, which was a marked improvement on earlier passive dialysis designs.An LOD of 1.4 mg l-1 was reported with a sampling frequency of 14 h-1. HuVer et al.202 compared a microwave digestion procedure with conventional hotplate wet digestion for the determination of Zn in isolated erythrocytes by AAS. The group also described a sample preparation method for the quantitative determination of 70Zn in erythrocytes by ICP-MS which involved solvent extraction with diisopropyl ether and ion exchange chromatography.In a study of trace elements in broncheolar lavage, Harlyk et al.112 used ETAAS to determine Cu and Fe, and FAAS to determine Zn concentrations. External calibration was satisfactory for Zn but quantitative determination of Cu and Fe required standard additions calibration. For all three elements, highest concentrations were determined in the supernatant after ultracentrifugation.High levels of Cu in the lavage fluid were associated with low Zn levels and vice versa. Bibi et al.203 determined Cu levels in electrophoresed protein fractions of serum from healthy and rheumatoid arthritis patients, using AAS. They observed that Cu binding to a-2-globulin was higher in arthritis suVerers but binding to albumin was similar in both healthy and diseased groups. They proposed that the method may be used in diagnosis of the condition.Hallfrisch et al.204 described the results of a study of plasma Cu and Zn levels in healthy, well nourished, American adults which demonstrated the 'antagonism' between the elements. At high levels of Cu intake, a 'quadratic' decline in Zn was observed in both men and women, which was overcome by increasing vitamin C intake. A closer correlation between caeruloplasmin and plasma Cu was observed in younger people than the elderly. A study of Cu levels in human placental tissue, using ETAAS with Zeeman eVect background correction, led Centeno et al.113 to propose that measurement of placental Cu may be a useful marker for the diagnosis of Menkes disease.Artacho et al.205 determined Zn in serum from insti- Zn concentration of 10.49 mmol l-1. The authors found no tutionalized elderly subjects, using ETAAS, and found a mean 729 J. Anal. At. Spectrom., 1999, 14, 717-781significant influence of gender on serum Zn levels and no statistical correlation between serum Zn and dietary Zn intake, indicating that serum Zn may not be a suitable index of Zn status in the elderly.Krivorucho et al.206 determined plasma and erythrocyte levels of Zn, and plasma Cu levels, in iron deficient pregnant women by AAS, to examine the influence of these elements on the progress and outcome of parturition. They found that by giving a Zn supplement as well as standard antianaemic treatment in the third trimester, problems at parturition were reduced and proposed that blood Zn and Cu be monitored to prevent possible obstetric complications.An interesting application of TXRF for the quantitative determination of Zn in alleged bee and snake venom samples was described by Blumelhuber et al.207 Combining the spectroscopic data obtained by FT-IR with the quantitative measurement of Zn in the samples enabled the researchers to identify the sources of the diVerent venoms.1.9.12 Gallium. With continuing advances in ICP-MS instrumentation, methods are being developed for a wider range of ultra-trace elements using the technique. Okazaki et al.208 developed an ICP-MS method for the determination of Ga in serum. They observed that a polyatomic interference from 37Cl16O2 on 69Ga was particularly significant at 1+9 v/v dilutions of serum. To overcome this and the observed matrix suppression from NaCl, measurements were made at the 71Ga mass using Co as an internal standard. 1.9.13 Germanium.A very sensitive LEAFS method for the direct determination of Ge in water and blood samples was developed by Aucelio et al.,127 in which a graphite furnace and L'vov platform were used to improve the eYciency of sample atomization. A number of chemical modifiers were evaluated. Optimum results were achieved with a Cu vapour laser for excitation and fluorescence detection at either 275.45 nm or 326.95 nm.The authors noted that the major source of background noise arose from black body radiation from the graphite furnace. Standard additions calibration was necessary for complex sample matrices containing high concentrations of Cl and an absolute LOD of 1 pg for Ge in whole blood was reported. 1.9.14 Indium. Imai et al.209 used Ni(NO3)2 as a chemical modifier for the determination of In in human milk and infant formula by ETAAS with Zeeman eVect background correction.Both sample types were diluted 1+1 v/v with 2% Triton X-100 and 10 ml volumes injected into the furnace with an equal volume of 5 g l-1 Ni in 1 M HNO the two matrices were 2.5 mg l-1 for milk and 2 mg l-1 for 3. Detection limits for In in infant formula. 1.9.15 Iodine. The eYcacy of a water soluble tertiary amine solution for the quantitative determination of total I in biological samples by ICP-MS was investigated by Gelinas et al.18,210,211 Two diVerent sample pretreatments were examined: simple dispersion into a 10% solution of the tertiary amine matrix or combustion with O2 in a closed or flow through system and collection of the residue into a 5% solution of the tertiary amines.The presence of low levels of I in the amine matrix solution restricted the limit of determination to 10 ng g-1, but use of the solution enabled the simultaneous determination of several other elements of toxicological significance.Good agreement with the certified value for I in six biological CRMs was obtained with the combustion method. Wardley and colleagues212 developed a rapid ICP-MS method, using standard additions calibration, to determine I in urine. An LOD of 0.38 nmol l-1 and precision of 15% at the 3 mmol l-1 level were reported. No age or gender diVerences were observed and the authors identified the potential of the 730 J. Anal. At. Spectrom., 1999, 14, 717-781 method for the diVerential diagnosis of thyroid dysfunction. Nixon et al.213 described a simple method for the determination of I in serum, whole blood and urine by ICP-MS, which was fully compliant with Good Laboratory Practice (GLP).Samples were diluted with 1% TMAH and matrix suppression eVects compensated for with Rh as internal standard. The method was used to establish reference values for a healthy population. The reference values determined were 33-81 mg l-1 for serum, 35-91 mg l-1 for blood and 100-450 mg l-1 for urine.Zaichick and Zaichick214 used both XRF and INAA to study the age dynamics of intrathyroid I. Both concentration and total I content of the thyroid were determined in necropsy samples from 90 subjects aged between 2 and 87. A mean thyroid I concentration of 345 mg g-1 was determined for healthy individuals aged 26-65, whilst significantly higher concentrations were found in both the young and elderly populations.The authors considered that the range of I values observed was suYciently wide to explain the sensitivity of diVerent populations to excesses or deficiencies in I intake. The determination of I by ICP-AES was used by Braselton et al.47 to monitor the plasma clearance of the radiographic contrast agent Iohexol. Samples were deproteinized with TCA- hydroxyamine and centrifuged. The supernatant was directly nebulized without decantation.To correct for interference from P at the 178.276 nm I measurement line, measurement of P was also made at the 214.914 nm line. The researchers found that for domestic pets an iodine dose of 300 mg kg-1, with blood sampling at 3-7 h, was satisfactory for accurate determination of the glomerular filtration rate. Determination of 129I and I isotope ratios in teeth and bones by AMS was made by Cornett et al.91 to assess their suitability as a dosimetric record of exposure to high neutron fluxes and as a method to determine the age of bone samples covering the period 15 million-75 million years before present.Sample treatment involved removal of contaminating soft tissue residue by a beetle colony, after which the samples were dried, ground and pyrolysed to extract 129I. Elevated levels of 129I were determined in samples exposed to fall out from nuclear weapons testing. 1.9.16 Iron. In a very interesting investigation of the chemical interactions between asbestos fibres and cultured lung cells, Seal et al.215 used electron spectroscopy, AAS and ESR to study the behaviour of chrysotile silicates in selected cultures of lung cells.The study findings led the authors to hypothesise that Fe species associated with the asbestos silicates are drawn into the cells where they may generate toxic oxygen species through Fenton-type reactions. Menendez-Fraga and colleagues216 used ETAAS to determine total and ultrafilterable Al and Fe in serum from dialysis patients administered desferrioxamine (DFO).Samples were simply diluted with ultra-pure water for both analytes and aqueous calibration was satisfactory for accurate quantitation. The researchers found that DFO administration 1 h before dialysis increased the ultrafilterable fraction of Al and Fe to 75% of the total, but this value declined to 38% 1 h after infusion. Determination of 54Fe and 57Fe isotopes in serum by ICP-MS with conventional nebulization are severely aVected both by polyatomic interferences from 40Ar14N and 40Ar16OH and by reduced nebulization eYciency caused by high serum protein concentrations.To reduce these interferences, Varnes217 developed a method in which serum samples were deproteinized and introduced into the ICP by ultrasonic nebulization Ar flow rates, an LOD of 1 mg l-1 was reported for both with membrane desolvation.With optimized RF power and Fe isotopes.3 3 1.9.17 Lanthanides. Buseth et al.63,62 developed an ETVICP-MS method in order to achieve the necessary detection limits for quantitative determination of lanthanide elements in various biological matrices. Comparable results were obtained for microwave digested samples and undigested slurried samples. The injection of H2O2 into the graphite furnace prevented the build-up of carbonaceous residue from undigested samples and trifluoromethane was found to be an eVective chemical modifier both for lowering the vaporization temperature and reducing memory eVects.Absolute LODs were in the range 1-20 fg for all lanthanides. Using the method the researchers found detectable levels of all lanthanides in human plasma from 30 healthy volunteers and in liver samples from unexposed rats. To determine La in urine quantitatively, Vicente et al.218 developed a complicated FI-ICP-AES method with oV-line chelation and preconcentration of the analyte.Lanthanum was extracted from 1 l of urine by chelation with quinolin-8-ol into CHCl and back extracted into H2O. The solution was reacted again with ethanolic quinolin-8-ol, preconcentrated onto an Amberlite ion exchange column and LOD of 0.09 ng ml-1 and recoveries of 98-101% were eluted with HNO directly into the nebulizer of the ICP. An reported. 1.9.18 Lead. There continues to be considerable interest in the development of low cost portable instruments for blood Pb analysis.A review of past, present and future developments of low cost tungsten filament atomization spectrometers for the determination of trace elements in biological matrices was presented by Parsons and Slavin.219 The authors focused on the problems in determining Pb in blood using such instruments. The same authors and colleagues120 evaluated a new tungsten filament atomizer for the direct determination of Pb in blood.Blood samples were diluted 1+4 v/v with an NH4H2PO4-HNO3-Triton X-100 chemical modifier and 15 ml volumes were deposited on the filament with a micropipette guided by an alignment device to ensure reproducible deposition. With power controlled heating, detection limits of 1-2 mg l-1 were reported with a precision that satisfied US Centre for Disease Control requirements. Bruhn et al.121 critically evaluated diVerent chemical modifiers for the determination of Pb in acid digests of blood and hair by ETAAS with a non-enclosed tungsten coil atomizer.More accurate and precise results for blood and hair CRMs were obtained with a Pd chemical modifier compared with phosphate modifiers. Djane et al.33 described an interesting approach to sample clean up and pre-concentration for the determination of Pb in urine by ETAAS or FAAS. Lead ions were extracted by proton gradient mass transfer across a supported liquid membrane of 40% di-2-ethylhexylphosphoric acid in kerosene into 1 M HNO and 6 mg l-1 were reported for ETAAS and FAAS, respectively.3. Extraction eYciency was 95% and LODs of 0.1 The method was validated by comparison with results obtained by direct ICP-MS. The method, however, is unlikely to be considered for routine analysis owing to analysis times of up to 45 min per sample. This review period has seen an enormous increase in studies to determine isotope ratios of trace elements in biological samples.A large proportion of the work has focused on Pb isotope measurements. Gwizada et al.80 described a double focusing magnetic sector ICP-MS method for the accurate determination of Pb isotope ratios in biological samples. Samples were digested with acid and spiked with Bi as internal standard. The method gave a measurement precision of<0.1% for 206Pb5204Pb, 207Pb5206Pb and 208Pb5206Pb ratios. Accuracy of the method was validated by comparison with a reference TIMS method.The authors used the method to identify and distinguish household Pb sources leading to elevated blood Pb levels in children. Amarasiriwardena et al.220 determined blood Pb levels and isotope ratios in Ecuadorian children from an area of high Pb use. Blood Pb levels in children exposed to emissions from lead pottery glazing were markedly elevated (43 mg dl-1) and the isotope ratio closely matched that found in soil samples collected close to the kilns.Hall and Zhu221,505 used HPLC coupled to ultrasonic nebulization ICP-MS to study isotope ratios of Pb associated with plasma proteins. Plasma samples were collected from patients who ingested soil samples with a modified Pb isotope ratio in order to study the kinetic parameters of plasma Pb binding. Ingested Pb was initially associated with albumin but transferred to caeruloplasmin, competing with Cu for the binding sites.Hinners et al.131,132 reported results of an inter-laboratory comparison of MS methods for the measurement of Pb isotope ratios in NIST SRM 1400 (bone ash). Lead isotope measurement by TIMS agreed to within 0.09% of previously certified values. Measurement of Pb isotope abundances by ICP-MS diVered by less than 0.17% with the values determined by TIMS. Wooland and colleagues79 used magnetic sector ICP-MS for rapid and precise measurement of Pb isotope ratios in biological materials.Their method measured Pb at six isotope masses, using 209Bi as internal standard, with a total measurement time of 5 min. The method was evaluated by analysis of NIST of 0.013 mg kg-1 and measurement precision for isotope ratios SRMs. Recoveries of 96-101% were reported, with an LOD of 0.07-0.22% RSD. Finally, Franklin et al.222 sequentially administered stable Pb isotopes to monkeys in order to investigate changes in blood Pb during pregnancy.Blood and bone Pb isotope ratios were determined by TIMS. The authors observed that bone Pb mobilization increased in late pregnancy and that there was substantial transplacental transfer of Pb. They estimated that between 7 and 39% of fetal skeletal Pb originated from the maternal skeleton. A 1997 American legal proposition relating to Pb contami- 3 3 nation of calcium supplements included a requirement for monitoring of Pb contamination by ICP-MS.This has resulted in several reports of methods developed for such monitoring. Bakowska149 described the determination of Pb in more than 20 types of calcium supplement by ICP-MS. Samples (0.1 g) were simply dissolved in HNO and diluted 1+49 v/v with H2O. Results were reported to reflect the amount of Pb contamination corresponding to a Ca dose at the recommended daily amount. Ahson et al.15 described an ETAAS method for the direct determination of Pb in calcium supplements using a molybdenum atomizer and thiourea as a chemical modifier.Sample slurries were prepared by ultrasonic agitation. Satisfactory results were obtained with calibration standards prepared in a CaCO solution and the analytical precision improved with smaller particle size. Results obtained from slurry samples agreed well with results from digested samples. Sharma and Barnes150 measured Pb in calcium supplements by ICP-MS following acid digestion under high temperature and pressure.Calibration standards were prepared in CaCO3 and the method was validated by analysis of animal bone SRM. Lead levels in natural supplements ranged from 8-28 mg g-1 Ca, whilst refined supplements had much lower levels (1-2 mg g-1 Ca). Zerwekh and Pak223 used ETAAS to measure bone Pb in osteoporosis patients given calcium supplements. The results suggested to the authors that Ca citrate supplementation did not pose a Pb intoxication risk. Rosen96 presented a review of L-XRF methods used to estimate bone Pb levels in adults and children from lead contaminated suburbs.Tantari et al.224 used XRF to measure finger bone Pb levels in occupationally exposed workers. Elevated bone Pb levels were observed even though blood Pb levels indicated very low Pb exposure. Ao et al.94 described a Monte Carlo statistical approach for correction of interference 731 J.Anal. At. Spectrom., 1999, 14, 717-781from Compton scatter in the in-vivo determination of Pb by L-XRF. 1.9.19 Magnesium. A review of current methodologies used 3 in clinical chemistry laboratories for the determination of Mg was presented by Ryan and Barbour.225 The article described the analytical precision that could be achieved by the diVerent techniques and highlighted the generally poor performance of laboratories in external quality assessment programmes.The article also discussed the relevance of methods for the determination of intracellular Mg. Pruvost et al.77 compared electronic impact mass spectrometry (EI-MS) and ICP-MS for the determination of Mg isotope ratios, using various statistical approaches to evaluate the correlation between methods. Improved precision<0.4% was obtained for Mg isotope ratios by ICP-MS compared with precisions of 1.3-2.6% for EI-MS.The ICP-MS method was used to diVerentiate exogenous and endogenous Mg, enabling the bioavailability of exogenous Mg from pharmaceutical preparations to be determined. Godlewska-Zylkiewicz et al.226 combined LC with ETAAS to determine Mg-protein species in human serum. Proteins were separated on an ion-exchange column and detected with a diode-array system. The authors observed that a CH COONa mobile phase stabilized Mg-protein complexes. The Mg concentration in the collected fractions was determined by ETAAS and the main Mg binding proteins were identified as albumin and globulin fractions.Several groups have studied Mg status in diVerent pathological conditions. Starobrat-Hermelin et al.227 investigated the value of Mg supplementation for children with attention deficient hyperactivity disorder (ADHD). Children with recognised ADHD and Mg deficiency, confirmed through determination of serum and hair Mg by AAS, responded positively to Mg supplementation over 6 months.Magnesium supplementation led to reduced hyperactivity and increased hair Mg levels. Rob et al.228 used AAS to monitor serum Mg levels in patients undergoing plasma exchange with albumin based substitutes. Plasma exchange led to a negative Mg balance and hypomagnesemia. Yoshida et al.229 determined Mg levels in bone and ligament samples from rats given an unbalanced mineral diet mimicking that found in amyotrophic lateral sclerosis (ALS) foci, and also in ligament and bone samples from cases of calcification of spinal ligaments (CSL).In both cases the Mg levels were significantly lower than controls indicating that low dietary intake of Mg may be a contributory factor for CSL and ALS. 1.9.20 Manganese. The determination of Mn by FI-ETAAS was used by Lang et al.230 as an indirect method for the quantitative determination of vitamin B6 in pharmaceutical preparations.Solubilized samples were reacted on-line with MnO2 at pH 4.5 and the reaction solution transferred to the atomizer of the AAS for determination of Mn. Recoveries of 98-102% were achieved for both tablets and injection solutions, but interferences from thiamine and riboflavin were identified. An ETAAS method for the determination of Mn in hair was described by Zhou and Ge,231 in which the acid digested hair was introduced into the furnace using a laboratory made probe system.An IR source was used to dry the 5 ml sample before introduction into the furnace followed by ashing at 300 °C and atomization at 2400 °C. The authors observed no interferences from other elements nor any memory eVect from the probe. An LOD of 11.7 pg was found. 1.9.21 Mercury. A variety of sample pretreatment procedures have been described for the determination of total Hg in biological matrices by atomic spectroscopic methods. Lamble and Hill22 developed an on-line microwave digestion procedure for the determination of total Hg in solid biological 732 J.Anal. At. Spectrom., 1999, 14, 717-781 3 3 samples by CVAFS. Slurried samples were mixed with HCl and KBr-KBrO and reacted in a PTFE coil within the microwave digester. Reduced HgII was subsequently reacted on-line with SnCl2 and the released Hg determined by AFS. The method was validated by analysis of several CRMs. Fernando et al.232 also developed a CVAFS method to determine Hg in blood and tissues of rats exposed to Hg.Their sample preparation also involved acid digestion with HNO3-H2SO4 followed by reduction with KBr- KBrO -hydroxylamine hydrochloride and reaction with SnCl2. Adeloju et al.233 observed that addition of H2SO4 prior to or following wet digestion of biological samples produced a significant improvement in sensitivity for the determination of Hg by CVAAS. A simple direct method for the determination of Hg in 4 urine, blood and digested tissues by ICP-MS was described by Moreton and Delves.151 Memory eVects from Hg were which complexed the Hg.Detection limits were 0.13 mg l-1 minimized by diluting samples with (NH4)2H2 EDTA in NH3, and 0.27 mg l-1 for blood and urine, respectively. The method was validated by analysis of CRMs and participation in external quality assessment schemes. The method was used to determine levels of Hg in blood and urine samples collected from Brazilian gold mine workers.All but one of the workers had blood and urine Hg levels above the 95% value for for UK industrial workers (19 mg l-1) and 17% of workers unexposed subjects, 55% had blood levels above the 95% value ance value (20 mmol mol-1 of creatinine). More importantly, had urine Hg levels above the UK occupational health guidsubjects living in a fishing village 100 km from the mine had significantly higher blood Hg levels than the mine workers, which the authors presumed to be related to fish consumption.As hepatitis and HIV were prevalent among the study subjects, a novel disinfection procedure was developed in which samples were pre-diluted with a virucide. Blood proteins were precipitated by the virucide and were redissolved with TMAH. In the ICP-MS method described by Mickley and Amato,234 samples were introduced into the plasma by electrothermal vaporization.Samples were combusted in a minitube furnace at 950 °C using an O2-Ar stream and cobalt oxide-alumina catalyst. The method was evaluated by analysing hair CRM IAEA-086 and an LOD of 19 pg was reported for this matrix. Lee et al.76 described an ETV-ID-ICP-MS method for the determination of Hg in urine. A mixed Pd-Mg(NO3)2-HCl chemical modifier gave optimum sensitivity for Hg, with an LOD of 0.02 mg l-1 being found. Analysis of CRM NIST 2670 toxic elements in freeze dried urine gave good agreement with the certified value.Rudner et al.235 described a novel separation and preconcentration treatment for the determination of Hg in biological samples by ICP-AES. Mercury was concentrated on a column containing a methylsalicylate chelating resin coupled to an FI manifold. Synthesis of the resin was reported to be faster and simpler than previously prepared chelating resins and the authors comprehensively evaluated factors aVecting the preconcentration step.Complexed Hg was eluted with thiourea and reacted on line with NaBH4 to generate Hg vapour. The method gave acceptable results for a variety of CRMs. Tao et al.16 solubilized samples of marine biological SRMs with TMAH for the determination of total Hg by FI-CVAAS. On-line addition of KMnO was necessary to obtain full recovery of both inorganic and organic Hg species. Various approaches have also been taken for the speciation of Hg.Perez-Corona and colleagues236 evaluated immobilized yeast cells on silica gel micro-columns for preconcentration and speciation of Hg. Inorganic Hg was retained by the silica support whilst methylmercury bound to the immobilized cells. for methyl Hg and 0.8 M CN- for HgII. Concentration factors Speciation was achieved by sequential elution with 0.02 M HCl of 15 and 100 were reported for organic and inorganic Hg,respectively. Gerbersmann et al.153 evaluated two derivatization-injection procedures for speciation of Hg in fish samples by GC-MIP-AES.In the first, microwave digested samples were derivatized by ethylation, extracted with hexane and injected, using a cooled injection system, for GC separation. In the second, the sample was reacted with NaBH4, followed by purge and trap injection onto the GC column. Wasik et al.76 described a method for speciation of Hg in biological samples by ICP-MS in which methyl and ethyl species were separated by purge and trap cryofocusing and chromatography at ambient temperatures.Optimization of Ar gas flows minimized peak broadening on the column. The authors noted that sensitivity and speed of analysis were limited by the acquisition rate of the quadrupole mass spectrometer. Willie et al.65 described a rapid method for the determination of total and inorganic Hg in biological samples by ETV-ICP-MS, following simple dissolution with TMAH.For determination of total Hg, injected sample was dried and atomized into the plasma. For inorganic Hg, an iodoacetic acid-acetic acid- thiosulfate chemical modifier was injected with the sample to form volatile methylmercury iodide. This was removed in the sample drying step, leaving only inorganic Hg to be quantified. The method was validated by analysis of marine tissue CRMs. In the clinical setting, Haswell et al.237 described CVAAS and ICP-MS methods for the determination of Hg in hair which were developed to support studies on transplacental transfer of Hg.The authors developed a small volume microwave digestion procedure to cope with the small quantities of hair from new-born babies. Barregard et al.238 used ELISA to determine levels of antinuclear auto-antibodies and immune complexes in Hg-exposed battery workers. Blood, plasma and urine Hg levels were determined by CVAAS. The authors found no associations between antibodies or complexes and any of the Hg exposure indices and no increased prevalence of abnormal antibody titres was observed.Barbosa et al.142 measured hair Hg levels as an indicator of Hg body burden in the indigenous population of the Amazon Basin. Samples were alkali digested and Hg determined by CVAAS. Hair Hg levels in non-Indian women ranged from 0.8-94.7 mg g-1, and in Indian women ranged from 0.8-13.3 mg g-1. A significant correlation between maternal hair Hg and hair Hg of breastfeeding infants was only observed in the non-Indian population.Segmented hair analysis indicated a 20% decrease in Hg body burden during pregnancy, which suggested significant placental transfer. 1.9.22 Molybdenum. As part of a European-wide project, Iversen and colleagues239 used ICP-MS to determine urine Mo levels in a healthy Danish population. Measurements were made at both 95Mo and 98Mo masses and no significant diVerences were observed between the levels determined at the two masses.The LOD for the method was 0.2 mg l-1 and a precision of 8.6% RSD was reported. Both uncorrected and creatinine corrected data were log normally distributed and a 95% parametric reference interval of 10-124 mg l-1 was calculated. There was no influence of gender or age on urine Mo concentrations. Of the many dietary factors examined, only butter consumption showed any significant correlation with urine Mo concentrations.An ETAAS method was developed by Haywood et al.240 to determine Mo accumulation in organs of sheep administered ammonium tetrathiomolybdate (TTM), a treatment for chronic Cu poisoning. They observed that Mo was widely distributed and accumulated in many organs including the brain and pituitary, and hypothesised that TTM treatment may redistribute excess liver Cu to the brain. 1.9.23 Nickel. An ETAAS method with slurry sampling for the determination of Ni in human scalp hair was described by Bermejo-Barrera et al.13 Washed hair was pulverized in a ball mill and the powder vigorously shaken with H2O to produce a slurry. The aqueous slurry was mixed with Mg(NO3)2, as a chemical modifier, and glycerol, and a 20 ml aliquot injected into the furnace.The method gave an LOD of 273 mg kg-1 and recoveries of NiII were 93-108%. The authors reported that matrix interferences caused less than a 5% suppression of the Ni absorbance signal.The method was evaluated by analysis of several hair CRMs and good agreement with certified values was found. In a study of the pulmonary damage in mice caused by combustion products from Ni coated polycarbonate, Larsen et al.241 used AAS to measure the Ni content of the ash following decomposition of the plastic. The findings led the authors to hypothesize that Ni lost through pyrolysis could account for the increased toxic eVects on pulmonary tissue through the formation of toxic Ni species.1.9.24 Platinum group metals. There is growing interest in the measurement of noble metals in relation to environmental contamination from automobile emissions. Very sensitive methods are required, however, to determine physiological levels of noble metals in biological fluids in the monitoring of environmental exposure. In the method developed by Begerow et al.70 for the determination of Pd and Pt in urine, measurements were made by double focusing magnetic sector ICP-MS.By using UV photolysis for decomposition of the organic matrix, very low reagent blank values were obtained and lowest detection limits were achieved operating the instrument in the low resolution mode. Practical LODs of 0.17 ng l-1 for Pd and 0.24 ng l-1 for Pt were found, but they were not for Pd and Pt in unexposed populations were 140 ng l-1 and improved with HR nickel cones.The reported reference values 1.8 ng l-1, respectively. A similar high resolution ICP-MS method was also developed by Krachler et al.69 for the determination of Pt group metals in urine. Low reagent blank values were again obtained using UV photolysis for sample digestion and sensitivity was improved further by using ultrasonic nebulization for sample introduction. The authors noted that interference on 106Pd from 106Cd and 40Ar66Zn, and on 103Rh by 206Pb2+ and 40Ar63Cu could not be disregarded at reported LODs were 0.25 ng l-1 for Pd and 0.03 ng l-1 for Pt the levels of interest. With a dilution factor of 1+20 v/v, and Rh.The authors found a mean urine Pt level of 1 ng l-1 in youngsters from urban and suburban areas of Rome. They also considered that Q-ICP-MS with ultrasonic nebulization had inadequate sensitivity for the quantitative determination of baseline levels of noble metals in urine.Sample introduction by ETV was used by Cairns and White242 for the determination of Pt in urine in order to monitor workers exposed to the element through the handling of cytotoxic drugs. In a comprehensive study of Pt levels in urban road dust, soils and biological fluids from environmentally and occupationally exposed populations, Farago et al.243 determined concentrations of Pt in blood and urine by ICP-MS. Measurable levels of Pt were reported in both occupationally and environmentally exposed groups. The authors noted that Pt levels in road dust were well correlated with traYc intensity but there was no correlation between Pt and Pb, suggesting that traYc emissions cannot be identified with certainty as the primary source of Pt.An ETA-LEAFS method was described by Aucelio and colleagues128 for the determination of Pt in biological samples. The authors thoroughly investigated furnace conditions to obtain optimum signal to noise ratios and obtained an absolute LOD of 50 fg.Analytical recoveries of 100-108% were reported for a range of biological matrices. The quantitative measurement of Pt in biological samples from patients undergoing chemotherapy with Pt drugs can usually be achieved with ETAAS. A comprehensive review, 733 J. Anal. At. Spectrom., 1999, 14, 717-7813. An LOD of leagues254 used N2 rather than Ar as the plasma gas for the with 177 references, of the clinical pharmacokinetics of carboplatin was presented by DuVull et al.244 The authors discussed methods of analysis and the development of models to describe the relationship between drug dose, toxicity and response.Milacic et al.245 described a simple ETAAS method for the determination of Pt in tissue biopsies in which 0.1 g samples were digested at 37 °C with HNO 3 mg l-1 was reported and aqueous calibration gave satisfactory results. Several papers in this review period again describe spectroscopic methods to study the pharmacokinetics of Pt based drugs for establishing appropriate administration regimes. Peng et al.246 measured free plasma Pt by ETAAS and Pt-DNA adducts by ELISA in a study of the relationship between adduct formation and pharmacokinetics of carboplatin and cisplatin.A weak correlation was found between adduct formation and the area under the unbound drug curve (AUC) several hours after infusion, but the relationship was lost beyond 24 h after infusion.Carboplatin formed lower levels of reactive adducts despite a much higher AUC for this drug. The authors concluded that interaction of the drug with the target was determined both by pharmacokinetic and cellular factors. Tokuhashi et al.246 used AAS to measure total and free Pt in plasma and urine in a study of the pharmacokinetics of cisplatin in children. Urinary excretion of Pt was only 27% after 48 h, leading the authors to hypothesise that other clearance pathways were important.They also concluded that dosing based on body surface area was inappropriate for children. 1.9.25 Selenium. In this review period, Se has replaced Pb as the element generating most scientific interest. Much of the work has arisen through interest and some concern over the Se status of many populations. A comprehensive evaluation of atomization techniques and chemical modifiers for the determination of total Se in human serum by ETAAS was undertaken by Gayon et al.247 Optimum performance was achieved with platform atomization.Satisfactory results were obtained with aqueous calibration standards if a 2CO3 Pd-Mg(NO3)2 chemical modifier was used, whereas the use as electrolyte. Selenium was measured at m/z 77 and 78. In a of Ni or Ni-Mg(NO3)2 necessitated matrix matched calibration standards. Cabon and Le Bihan248 examined the atomization behaviour of Se in the presence of high salt matrices.They noted that with a high SO42- content, Sr with rapidly taken up by erythrocytes and reduced to selenide. The Pd proved to be a better chemical modifier than Pd alone for selenide reappeared in the plasma bound to albumin and stabilizing Se species. In the method developed by Chen gradually disappeared again to be incorporated into et al.,249 serum samples were simply mixed with an selenoprotein-P and GSHPx.A robust method, using micro- HNO3-Triton X-100 chemical modifier by ultrasonic slurry bore ion exchange chromatography coupled to ETAAS was sampling for ETAAS analysis using STPF conditions. described by Emteborg et al.262 to determine Se species in Ultrasonication of the sample led to improved homogeneity biological materials. Four inorganic and organic species were and stabilization of Se in the diluted sample. Tyson et al.250 separated within six minutes.A Pd-Mg(NO3)2 chemical modidetermined total Se in human urine by FI-HG-ETAAS follow- fier was found to thermally stabilize all Se species up to ing digestion and reduction of organoselenium species by acid 1000 °C and LODs of 2.8-4.1 mg l-1 were reported. The refluxing with HBr-KBrO3. Following reduction, excess Br method was evaluated by analysing biological CRMs spiked was removed by addition of hydroxyammonium chloride. The with diVerent Se species. digest was diluted with 10% HCl and injected into a stream Various groups have determined Se in biological matrices of 0.2% NaBH4-10% HCl.Hydrides were trapped on an iridium coated graphite tube for determination by ETAAS. Recoveries >95% were reported from samples spiked with typical organoselenium compounds. Several groups have described ICP-MS methods for the determination of Se in body fluids. Sieniawska et al.251 described a simple 1+15 v/v dilution procedure for the determination of Se in blood and plasma.The diluent contained 1% butanol to overcome interferences from Ar adducts on 78Se. The method gave an LOD of 0.02 mmol l-1 and was validated by demonstration of excellent performance in two international quality assessment programmes. This same group252 and also the group of Nichol et al.253 combined aYnity chromatography with ICP-MS to quantify selenopro- 734 J. Anal. At. Spectrom., 1999, 14, 717-781 teins in human serum.Two independent aYnity columns were used to separate selenoprotein-P, glutathione peroxidase (GSHPx) and albumin. Analysis of two reference sera found the distribution of Se to be 53 and 54% with selenoprotein-P, 21 and 29% with GSHPx, and 27% and 13% with albumin. To overcome polyatomic interferences, Furuta and coldetermination of Se by ID-MIP-MS. The authors measured Se in NIES 4, human serum SRM, using an enriched 78Se spike solution and determining the 78Se580Se ratio with a precision better than 1% RSD.Jimenez et al.255 used ethylation derivatization with NaB(C2H5)4 to volatilize selectively selenoaminoacids for on-line determination by ICP-MS. Selenium alkyl derivatives were preconcentrated by cryogenic trapping or solid phase adsorption for determination of Se at ng l-1 levels. Finally, in this section, Turner et al.256 described a method for the determination of Se in serum by ETV-ICP-MS.By selecting appropriate furnace programmes, the authors eliminated interferences from 81BrH on 82Se and gave an LOD of <0.1 ng g-1. 40Ar37Cl on 77Se. The improved transport eYciency of ETV An overview of methods developed for speciation of Se in biological samples was presented by Behne et al.257 Cooney and colleagues258 presented the results of their studies on the separation and identification of Se metabolites using HPLCICP-MS. Using diVerent chromatographic techniques, they speciated seven inorganic and organic Se species in human urine, of which only one was tentatively identified as selenomethionine.Uden et al.259 developed methods employing derivatization and headspace GC with MIP-AES or ion pair chromatography with ICP-MS to study Se speciation in biological samples. They applied the methods to the determination of Se species in nutritional supplements. Michalke and Schramel260 used capillary zone electrophoresis and isoelectric focusing to separate Se species in human serum and milk for determination by ICP-MS.Six organic and inorganic species were separated on an uncoated capillary for electrophoresis and a coated capillary for isoelectric focusing using Na very elegant study, Suzuki et al.261 used HPLC-ICP-MS to study the metabolism of Se in rats administered enriched Se isotopes. The authors observed that administered selenite was to establish reference values for Se in the general populations of diVerent countries.However, there appears to be no standardization or consensus on the most appropriate biological indicators of Se status. Veillon et al.7 reported that infection risks from viruses could be overcome by simple pre-dilution with 0.1 M HNO3 for the determination of Se in serum by ETAAS. Diluted samples were mixed with an Ni-Mg(NO3)2 chemical modifier for quantitation of Se. The acid concentration was suYciently low to prevent protein precipitation whilst still inactivating viruses.Meissner and Hohne263 used ETAAS to establish Se reference values of 0.68-1.52 mmol l-1 for blood and 0.85-1.85 mmol l-1 for serum in the population of the Dresden area of Germany, which they considered to indicate marginal Se deficiency for this population. A serumSe reference interval of 60-106 mg l-1 (0.75-1.34 mmol l-1) was reported by Torra et al.264 for a healthy Northern Spanish (<45 mg l-1).Dhindsa et al.265 found a mean plasma Se level population. No subjects showed excessive Se deficiency of 91.8 mg l-1 (53-131 mg l-1) in the Sikh population of Sydney, Australia. They considered that the Se status was adequate even though a vegetarian diet was common. The establishment of reliable reference values depends on the adequacy of the analytical method and satisfactory performance, demonstrated by analysis of control materials.Morisi et al.133 presented results of an inter-laboratory study of the determination of Se in serum control materials spiked with inorganic Se. Russo266 examined the relationship between Se status and the incidence of colorectal cancer, using ETAAS to determine plasma Se levels. Mean plasma Se levels in cancer patients and controls were 107 and 120 mg l-1, respectively, and statistical analysis indicated that individuals with the highest quartile of plasma Se levels had 0.24 times the risk for colorectal adenoma compared with individuals in the lowest quartile. The authors hypothesised that Se may be a useful chemopreventative agent for colorectal neoplasia.1.9.26 Silicon. The use of silicone implants in cosmetic 2O. A 10 ml aliquot of the diluted both Mg and Sr. In the study of Tanaka et al.277 Sr levels in surgery continues to stimulate studies on the determination of Si in biological matrices. A review examining the toxicity of organic and inorganic Si compounds in humans was produced by Lugowski et al.267 Topics included the measurement of total Si in blood and other body fluids and methods for speciation of Si.A need for reliable CRMs was highlighted. Several methods for the determination of total Si in biological fluids and tissues by ETAAS have been described in this review period. A method for the direct determination of Si in urine was described by Kobayashi et al.268,269 in which urine was diluted 1+499 v/v with H sample was injected into the furnace with an equal volume of a 5% Ni solution as chemical modifier, ashed at 1600 °C and atomized at 3000 °C.The method was evaluated by comparison with an ICP-AES method. The method was also used for the determination of Si in blood.268 Blood was diluted 1+19 v/v with 1% Triton X-100 and injected with the Ni chemical modifier. An LOD of 0.7 mg l-1 was reported for Si in blood but recoveries were only around 70%.For the determination of Si in serum and acid digested breast tissue, Leung and Edmond270 diluted samples 1+3 v/v with a complex chemical modifier solution containing LaO, CaCl2, (NH4 )2HPO4, EDTA, EtOH and Triton X-100. An ashing temperature of 1400 °C and atomization temperature of 2700 °C with gas stop were found to give optimum absorbance signals. The method was used to establish reference intervals for Si samples obtained from women with silicone breast implants.Lykissa et al.271 described the results of a series of studies investigating the release of Pt and low molecular weight silicones from breast implants. The release of silicones from intact implants into lipid rich oil media, aqueous tissue culture media and emulsions of the two was investigated. Silicon released into the media was quantified by GC with detection by either AES or MS. Platinum release was quantified by ICP-MS.Leakage of silicones was greatest when the surrounding medium was lipidrich and leakage levels of up to 10 mg d-1 were observed at 37 °C. Platinum leakage levels of up to 20 mg d-1 were also recorded. The observations led the authors to conclude that leakage of both elements from breast implants could lead to significant accumulation in lipid-rich tissues. 1.9.27 Silver. A sample treatment involving digestion with H2SO4, reaction with 30% KI-2% ascorbic acid and extraction into IBMK was developed by Luo et al.272 for the determination of Ag in whole blood by ETAAS.Optimized ashing and atomization temperatures were found to be 500 °C and 2300 °C, respectively, and calibration was linear up to 100 mg l-1. Analytical recoveries ranged from 89 to 110% with a method precision of 4.8-13% RSD. The method was also used to determine Ag in serum and urine. Lech273 described an FAAS method for the quantitative determination of Ag in post-mortem samples from a fatal case of Ag poisoning.Tissues were digested with HNO3-H2SO4 and analysed by FAAS using an air-C2H2 flame. The highest concentrations of Ag were found in the spleen, heart and lungs. The authors hypothesised that diVerential tissue aYnities for Ag may be associated with the levels of Ag binding proteins in the basement membrane of each tissue. 1.9.28 Sodium and potassium. Both Zoppi and colleagues274 and Ziebig et al.275 discussed factors responsible for the observed diVerences in the determination of Na and K in sera by diVerent analytical techniques.In the first, serum osmolality was identified as the main factor for diVerent values of Na and K determined by ion specific electrodes and flame photometry. In the second, higher values for both Na and K were determined by direct potentiometry compared to flame photometry for samples with high protein concentrations. In a study on the eVect of dietary Na on biochemical markers of bone metabolism in young women, Ginty et al.276 determined urine Na and K by flame photometry and urine Ca and Mg by AAS.The researchers identified an Na induced calciuria in Na sensitive women, but observed that the calciuria was not associated with increased bone resorption or turnover. 1.9.29 Strontium. Two studies described the determination3 of Sr in teeth by AAS. In the method used by Perez-Jordan et al.,27 teeth samples were powdered and digested with HNO in a closed-flow microwave system for 10 min for analysis of enamel and dentin were compared in both healthy and diseased teeth.The authors found that in sound teeth, Sr levels were not aVected by gender or degree of dental disease. On the other hand, in carious teeth, Sr levels in enamel increased with the degree of decay. The authors hypothesised that Sr may act synergistically with other trace elements in cariostatic activity. The levels of Sr in human hair were determined by Zhang et al.278 using FAAS.Hair was digested with HNO3-H2O2 and the digest mixed with a 20% surfactant solution for nebulization into an air-C2H2 flame. Interference from Al required the use of standard additions calibration for accurate quantitation. The addition of surfactant to the sample solution gave a 55% enhancement of Sr absorbance. A HR-ICP-MS method was described by Latkoczy et al.82 for the determination of Sr isotope ratios in prehistoric human bone samples, in which optimized operating parameters including correction for mass bias and dead time were investigated.When the instrument was fitted with a microconcentric nebulizer and installed in a pressurized ultraclean room with temperature control, 87Sr586Sr isotope ratios could be determined with a precision better than 0.035% RSD. Such high precision was needed for accurate interpretation of paleoanthropological specimens.The authors used the method to analyse several 7000 yr old human skeleton samples from lower Austria in order to confirm the provenance of the individuals. 1.9.30 Titanium. A comparative study of ICP-AES and ETAAS methods for the determination of Ti in human plasma was made by Einhauser et al.,45 in order to determine Ti concentrations in plasma of patients administered the Ti containing anticancer drug Budotitane.For measurement by ICP-AES, dilution of serum 1+99 v/v with H2O and sample introduction by ultrasonic nebulization gave satisfactory 735 J. Anal. At. Spectrom., 1999, 14, 717-781results with no evidence of matrix interferences. The determination of Ti by ETAAS, however, was more problematic. A complex furnace programme was required to minimize matrix interference eVects and to reduce carbide formation. Memory eVects were observed with both longitudinally and transversely heated furnaces, due to the refractory nature of the element.The authors concluded that ICP-AES was better suited than ETAAS for the determination of plasma Ti in cases of therapeutic drug monitoring. 1.9.31 Thallium. Fleischer279 described an ETAAS method with Zeeman eVect background correction for the direct determination of Tl in urine from occupationally exposed workers. Urine was injected directly onto the platform of a pyrolytically coated graphite tube together with a tetraamine-Pd(NO fier.Standard additions calibration was necessary for accurate quantitation of Tl. 1.9.32 Tin. Saeki et al.280 described a microwave digestion 3 of ICP-MS for the quantitative measurement of uranides in biological matrices. Two groups have described ICP-MS methods for the determination of U in urine in order to monitor exposed workers. The study by Schramel et al.73,282 described a rapid, sensitive method in which urine samples were sequentially acidified with HNO and HCl for determination by ICP-MS with pneumatic nebulization.To compensate for matrix suppression and nebulization eVects due to variations in urine density, viscosity and mineral content, internal standardization with Ir was necessary. Satisfactory results were obtained with calibration standards prepared in 3.5% HNO3-1.5% HCl but more accurate quantitation at very 3)2-Mg(NO3)2-NH4NO3 chemical modilow levels was achieved with standard additions calibration.The method was equally suitable for the determination of U and Th in urine with LODs of 0.5 ng l-1 reported for each element. The method was evaluated by comparison with results obtained by alpha-spectrometry. In the ICP-MS method developed by Caddia and Iversen,283 for U in urine, sample introduction was also by pneumatic nebulization following dilution of urine samples 1+19 v/v with 1% HNO3.Standard additions calibration with Ir as internal standard was again necessary to correct for adverse matrix eVects. An LOD of 0.32 ng l-1 and precision of 2-4% RSD were reported. Analysis of samples from non-occupationally exposed individuals gave median urine U levels of 13.5 ng l-1 for males and 17.6 ng l-1 for females. The authors emphasised that careful control of blank contamination was essential to achieve suYciently low detection limits.A HR-ICP-MS method was used by Nanni and colleagues72 to determine U and Th in urine of exposed workers from a U processing plant. Organic matrix was partially removed by drying the urine samples at 70-80 °C and dissolving the residue in 1% HNO3. The authors investigated the eVect of matrix suppression and observed that signal suppression became significant at dilution factors less than 10. Optimum results were obtained with matrix matched Detection limits of 0.01 mg l-1 for U and 0.26 mg l-1 for Th calibration standards and internal standardization with Bi.were reported. procedure, using HNO3, for the determination of total Sn in biological materials by ICP-MS. With a 100 mg sample, digested and diluted to 10 ml, an LOD of 10 ng g-1 could be achieved. Good agreement with certified values was obtained for three biological CRMs. Interferences on the quantitation of Sn were noted when HCl was used in the digestion mixture.Microwave digestion procedures were also described by Schmitt and colleagues155 for the speciation analysis of organotin compounds in marine biological materials by GC-AES. One- and two-stage sample preparation procedures were examined. In the one-stage process, lyophilized tissues were digested with CH COOH-nonane-Na ethylborate. In the two stage process, tissue samples were first digested with TMAH, acidified to pH 5, and extracted into nonane-ethylborate.Organic supernatants from both procedures were chromatographed on a DB-210 column with diethyl ether as eluent and Sn quantified by AES. Both procedures were validated by analysis of NIES Fish tissue CRM, which has certified values for tributyl- and triphenyltin species. Detection limits for tributyltin and triphenyltin were 2-10 and 20-40 ng g-1, respectively. Martin et al.281 described a method combining HG, cryogenic trapping and GC separation with AAS detection of Sn for the determination of low molecular weight organotin compounds in brain tissue of rats exposed to trimethyltin.The method was suYciently sensitive to determine levels of Sn below 0.2 ng in tissue from exposed animals. The method was subsequently used to measure Sn in human brain tissue showing evidence of Alzheimers disease. No low molecular weight organotin species were detected in these samples. A review of AAS, GC and LC methods for the determination of organotins in biological and environmental samples was presented by Horiguchi.154 The author also reviewed the eVects of organotin compounds on the human body, paying particular attention to their role in endocrine disruption.1.9.33 Tungsten. A simple method for the quantitative deter- 3 at 60 °C for 12 h. Tungsten was measured mination of W in biological fluids, hair and nails by ICP-AES was described by Marquet et al.46 in order to monitor a bizarre case of severe acute W intoxication, in which a quantity of wine and beer that had been rinsed in a hot gun barrel was consumed by a military recruit. Hair and nail samples were digested in HNO at 207.91 nm with the 193.03 C line as reference and using Ar as nebulizer, sheath and coolant gas.Initial blood and urine W levels, following hospital admission, were determined to be 5 mg l-1 and 101 mg l-1, respectively, and were confirmed by ICP-MS. Elevated W levels were also found in hair and nails.736 J. Anal. At. Spectrom., 1999, 14, 717-781 Blood levels remained elevated (>5 mg l-1) after 6 courses of haemodialysis over 13 days. 1.9.34 Uranides. There has been growing interest in the use 3 An ICP-MS method with sample introduction using a microconcentric nebulizer was described by Pietrzak and Kaplan284 for the quantitative determination of Pu in an artificial urine reference material. Plutonium isotopes were extracted from the urine matrix by co-precipitation and acid digestion, followed by anion exchange chromatography.All procedures were performed in a clean room. The absolute LOD for the method was reported to be 1-2 fg for 239Pu, which was comparable with the fission track analysis method currently used for accurate quantitation of Pu. 1.9.35 Vanadium. To overcome polyatomic interferences on the determination of V in urine by ICP-MS, Minnich et al.52 designed a cryogenic desolvation system, which was coupled to an ultrasonic nebulizer.Cryogenic desolvation markedly reduced the 35Cl16O interference on V by reducing the amount of Cl and O reaching the plasma through condensation of HCl and removal of water vapour. Matrix suppression was also corrected for by internal standardization with Sc. The method was found to be satisfactory for rapid screening of urine samples from occupationally exposed workers in order to assess the degree of exposure. 1.10 Conclusions Speciation features prominently in this review.Elements featured in previous Updates, such as As, Hg and Sn, are still important but other elements have been actively studied,notably Se (section 1.9.25). Three articles dealt with general aspects of speciation, giving advice on sample preparation,1 analytical strategies2 and improving reliability and speed of analysis.3 In this last, £obinski et al.reason that, for speciation to be part of the normal output of a routine laboratory and therefore capable of being included in environmental and occupational legislation, methods need to be faster than those developed previously to make them commercially viable. Moreover, they need to be more reliable, thus reducing the standard of competence required of the analyst carrying out the determination. They envisaged that the sample preparation and chromatographic separation steps should form a compact accessory for an atomic spectrometer.Their example of replacing a commercial gas chromatograph with an isothermal multicapillary column 22 cm long illustrates this point clearly. Work on microwave-assisted sample preparation by their group3,155 and others153 has reduced preparation times to a few minutes. Many of the on-line speciation systems using FI technology seem to be approaching the goals outlined above. The introduction of UV photolysis, for example by Tsalev et al.,25 seems to have simplified on-line systems for the speciation of As.It is obvious from the publications that more laboratories now have double focusing magnetic sector ICP-MS (also called HR-ICP-MS). In multielement analysis, this technique seems capable of accurately measuring the clinically important elements, Cu and Zn, in biological samples68 which suVer from interference when determined by Q-ICP-MS.In low resolution mode, the technique oVers impressive sensitivity, which has been exploited well in the determination of physiological concentrations of the Pt group metals in urine.69,70 This is becoming a topical subject as evidence grows for the release of these elements into the environment from catalytic converters in cars (see section 1.9.24). An important advantage of HR-ICP-MS is the high precision with which isotope ratios can be measured, oVering an easier and more rapid alternative to TIMS.79,81-83 This was confirmed in an inter-laboratory comparison of the determination of Pb isotope abundance in a Bone Ash SRM in which results by ICP-MS were statistically equivalent to those obtained by TIMS.132 There have been interesting developments in the use of tungsten-coil atomizers (see section 1.4).Conference presentations on the application to ETV-ICP-MS118 and in multielement ETAAS119 are intriguing. As manual injection is generally used with these atomizers precision is not good, and this reminds this writer (DJH) of the early days of ETAAS before autosamplers were available.Parsons et al.120 used an alignment guide to improve precision and Bruhn et al.121-123 have demonstrated the importance of the modifier in achieving accuracy and precision. It is apparent that the best modifier is not necessarily that which is best for a graphite furnace. 2 Analysis of foods and beverages This review follows on from last year's,6 and covers work published during the year ended October 1998, describing the analysis of foods and beverages by atomic spectrometric techniques.It includes papers and some conference abstracts which present novel work and significant developments in instrumental and analytical techniques, and their applications. Table 1 complements the text with summaries of these publications. 2.1 Sampling and sample preparation 2.1.1 Extraction.Comparisons of diVerent extraction methods were described by three groups. Ali et al.285 compared the eYciencies of three methods (wet digestion, CHCl3 extraction and TCA extraction) in extracting Ca, Cr, Cu, Mg, Mn, 3 Pb and Zn from buValo milk for measurement by AAS. Elements such as Cu and Mn were not detected in samples prepared with TCA, which gave optimum extraction for Ca, Cr, Ni, Pb and Zn. The best results for Cu and Mn required initial digestion in HNO followed by removal of organic residues in CHCl3.A conference presentation by Ponce de Leon et al.286 compared preparation methods for trace element analysis of herbal medicinal teas by ICP-MS or ICP-AES. They used a slurry technique with samples prepared by infusion or microwave digestion, discussing the advantages and limitations of each technique and noting the trace element content of herbal medicines from diVerent regions which are claimed to have the same curative properties.It is to be hoped that this work will be published in full. Two procedures for leaching trace elements from food 3, packaging paper boards are currently proposed by the European Commission: (i ) immersion in distilled water for 24 h at 23 °C (extraction test); and (ii ) immersion in 3% v/v acetic acid for 24 h at 40 °C (migration test). Conti287 used both methods and AAS to measure the levels of Cd, Cr, Hg and Pb in 15 samples of paper boards used for packaging pasta and cereal products.It was found that most of the samples contained trace element levels higher than the limits specified by the European Commission and that the diVerence in results for the two extraction methods were considerable. The author recommended use of the more drastic migration test when a higher degree of food packaging safety is required. A simple procedure was developed by El Azouzi and co-workers288 for the room temperature leaching of trace elements from mussel samples with a solution of 1.6 M HNO 1.2 M HCl and 0.1 M H2O2.The method involved the use of a sonication time of 120 min with determination by FAAS and ETAAS. The leaching of Cs and Sc were poor, Cd, Co, Cr, Rb and Se were partially leached and quantitative recovery was achieved for Ca, Cu, Fe, K, Mg, Mn, Na, V and Zn. The results obtained by the leaching procedure were evaluated by comparison with those obtained by ICP-MS and AAS following microwave-assisted digestion and also by solid sample analysis by NAA.The method gave LODs of 0.081, 0.012, 0.059, 0.002 and 0.007 mg ml-1 for Ca, Cu, Fe, Mg and Zn, respectively, and 0.342 mg ml-1 for Mn. Recovery from spiked samples ranged from 92 to 109%, with relative errors <9% for analysis of a certified mussel tissue. Ozdemir and Gucer289 described a photodecomposition method for preparing tea infusions for trace element analysis by FAAS.The dissolved organic substances such as polyphenols and alkaloids present analytical problems, particularly tannic acid, which can cause an apparent increase in Fe and Mn concentrations. It was reported that the total dissolved organic substances were completely destroyed by a UV-H2O2 decomposition technique. Two decomposition methods were compared for the determination of Al, Ca, Cu, Fe, K, Mg, Mn, Na and Zn and a lower standard deviation was reported for the UV-H2O2 decomposition. Sample preparation techniques by dry ashing for As, Cu, Fe and Pb determination in sugar were reported by Leblebici and Volkan.290 White sugar samples were dry ashed with either H2SO4 or Mg(NO3)2 prior to measurement of As by HGAAS and Cu, Fe and Pb by FAAS.Very little diVerence in recoveries (ranging from 87.6-97.4%) was noted between the two methods for any of the elements measured.This review year saw increasing interest in the development of methods to solubilize tissues with TMAH and tertiary amines. Two methods are described here for multi-element determination, and techniques specific to the analysis of I are considered in section 2.6.2. Pozebon et al.17 proposed a method for preparing solid biological samples for analysis by ETV-ICP-MS. A solution or slurry was formed by mixing 20-100 mg sample with 10-200 ml of a 25%m/v TMAH solution.Complete dissolution 737 J. Anal. At. Spectrom., 1999, 14, 717-781was obtained for animal tissues, and slurries for plant and whole egg powder. The slurries were stirred manually during measurement after every three readings, and good results were obtained for four CRMs using external calibration and, in some cases, analyte additions method, for Ag, As, Co, Cu, Mn, Ni, Se, Te and V.However, Cd and Cr could not be measured in the bovine muscle sample owing to matrix eVects and spectral interferences, respectively.Krushevska et al. used a conference presentation to discuss the advantages of the addition of tertiary amine mixtures in the analysis of food and biological samples by ICP-MS and ICP-AES.19 They summarized the techniques developed and described applications for the accurate ICP-AES determination of low levels of Si in food, the sensitive and reliablemeasurement by ICP-MS of As and Se in milk and food, the determination of major and trace elements in powdered, skimmed and whole milk, and the ICP-MS analysis of I in food and biological samples.A commercial tertiary amine reagent, CFA-C, neutralized the eVect of HF used for sample digestion, and helped to prevent it attacking Si-containing parts of the ICP system during Si analysis. This eVect was applied to ICP-MS analysis of biological samples which had been microwave-digested in HNO3-H2O2-HF mixtures.Signal enhancement was noted for trating Pb2+ from tap and sea-water for analysis by ICP-AES As and Se. They also reported that CFA-C dissociated casein micelles in milk and stabilized the liquid phase cations, an eVect which had not been observed in the presence of other alkaline solutions such as ammonia or NaOH. This had enabled the establishment of a direct method for measurement in milk of Ca, K, Mg, Na, P and Zn by ICP-AES and Al, Ba, Cu, I, Mn, Mo, Pb, Rb, Sb, Se and Zn by ICP-MS.2.1.2 Digestion. A new high temperature/pressure flow system for sample digestion was described in a conference abstract20 for on-line digestion of biological samples with measurement with ICP-AES. Digestion temperature and pressure were significantly increased by the use of special HPLC and GC materials such as Teflon-lined tubing, glass-lined tubing, quartz capillaries with thick walls and Pt/Ir capillaries. A HPLC pump permitted a working pressure up to 40MPa and the capillaries could be heated to give digestion temperatures in the range 250-350 °C.Insertion of a restrictor with high flow resistance at the end of the capillary created a quasi-closed system within which a liquid could be heated to much higher temperatures than its atmospheric boiling-point without generating any vapour. The degree of sample destruction was characterized by residual C content after digestion, which was measured by ICP-AES as less than 1%.First results for sample digestion were presented, the applicability of diVerent tube materials discussed and the feasibility of on-line determination of trace elements by ICP-AES after digestion evaluated. The authors believe that the system has great potential for this and other detection methods, and the publication of this preliminary work and follow-up studies will be welcome, particularly with details of sample sizes used, LODs achieved and system hygiene.3-H2O2-HF for the determination of total for measuring Pb in water by FAAS. Samples (30 ml ) were 3 2O2. Excess HF 3BO3. Matrix eVects from Ca, K, Mg, segmented with IBMK. The tetrabutylammonium iodoplumb- 3 4 3 Digestion methods for the measurement of Al in foods have been described by two groups. Sun et al.291 used microwave digestion with HNO Al in seafood and meat by ICP-AES. Lyophilized samples were first digested with HNO and HF in closed vessels with an additional digestion in open vessels with H was removed with H Na and HNO were investigated, together with possible spectral interferences. Variations in microwave power and the amount of HF used were reported.Analysis of CRMs and recoveries of spikes (95.2-97.6%) were used to demonstrate the reliability of the technique. Twelve samples of meat and seafood were analysed and the results compared with those obtained following hot plate digestion with HNO -HClO and with HNO3-H2O2 microwave digestions.It was reported that tap water, rain water and sea-water were 94-100%. the digestion without addition of HF was incomplete for the 738 J. Anal. At. Spectrom., 1999, 14, 717-781 determination of total Al. A group in Poland used hot concentrated HNO3-H2SO4-HClO4 (1+1+1, details given) in a two-stage reaction to decompose portions (0.1-100 g) of various homogenized foods.292 After evaporation of the acids, the residues were dissolved in 1 ml of 50% HCl and diluted with H2O.This solution was filtered and treated with 1 ml 6 M acetic acid, neutralized with 700 ml 6 M ammonia and adjusted to pH 6.1-6.2 with 5 ml acetic acid-ammonia buVer. The solution was extracted with 2 ml of 0.3% NaDDC in CHCl3 and 5 ml CHCl3. The aqueous phase was extracted with 5 ml of 2% quinolin-8-ol in CHCl3 and the Al-oxine complex was measured by spectrophotometry at 385 nm.The recovered 309.3 nm. Detection limits of 2.5 mg per sample and 6 mg ml-1 complex in a 4% KCl matrix was measured by FAAS at were reported for spectrophotometry and FAAS, respectively, and the Al contents of a range of foods were tabulated. 2.1.3 Preconcentration. Techniques for the preconcentration of trace elements in water were described by five groups. A novel Pb2+ ion exchange resin, based on a Pb2+ ion templated polymer, was used by Bae et al.293 for removing and preconcenmolecularly imprinted for Pb2+ by creating polymers with or a simple colorimetric assay.The ion exchange resin was cavities lined with complexing ligands arranged to match the size of Pb2+. The Pb2+ resin consisted of Pb-vinylbenzoate charge, co-ordination number, co-ordination geometry and complex and divinylbenzene in styrene using chemical initiation by azobisisobutyronitrile. Details of the synthesis and characterization of the templated resin have been presented the recovery of Pb2+ measured by ICP-AES when using the previously by this group, and the current publication compared templated resin with three other ion exchange resins (Chelex-100, thiol-based Duolite GT-73 and a proprietary NASA polyacrylic acid resin).Samples preconcentrated on cations, and this resin was the most selective for Pb2+ of all the templated ion exchange resin contained almost no other those tested, giving an LOD of 1.0 ppb.The authors proposed that the templated resin is suitable for a field-ready test kit for the determination of Pb2+ in environmental samples when used with colorimetric analysis. Anezaki et al.294 adjusted 150 ml of H2O to pH 2 with 6 M HCl, then mixed it successively with 4 ml of anion exchange resin suspension, 1.5 ml 20 nM APDC and 1.5 ml 3 M NaClO4. The mixture was adjusted to pH 6 with 2 ml of 1 M ammonium acetate-1 M NaOH (1+1), stirred for 10 min then filtered under vacuum.The filter was placed in a beaker with 1 ml 0.1 M HCl containing 100 mg Pd and the beaker was sealed with film and irradiated ultrasonically for 1 min. An aliquot of the suspension was analysed Pb, respectively. Detection limits were 0.17 ng l-1 for Cd with by ETAAS with detection at 228.8 and 283.3 nm for Cd and recoveries of 98.3-100%, and 5.7 ng l-1 for Pb with recoveries of 99.3-99.6%, and interference eVects were tabulated. Tao and Fang295 described a dual stage preconcentration system using FI on-line ion exchange followed by solvent extraction pumped through a 1 ml column of Amberlite IRA 728 resin for 1 min.The pump was stopped and a second pump eluted the Pb with 1 M tetrabutylammonium bromide, which was ate ion pair was extracted into this solvent in a 30 cm reaction coil. A 50 ml portion of the extract was retained in a holding coil while excess solvent and aqueous solution were run to waste.Each extract was neutralized with NH3, mixed with 25 ml 1 M ammonium acetate buVer and diluted to 250 ml for analysis by FAAS at 283.3 nm. The enrichment factor was 550, and the LOD was 0.3 mg l-1. Recoveries of Pb added to A conference report296 described in considerable detail a, method for the preconcentration of impurities in high purity and drinking water for measurement by ICP-AES and ETAAS. The impurities (Al, Ag, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Na, Hg, K, Mg, Mn, Mo, Ni, Pb, Si, Sn, Te, Ti, V, W, Zn) were co-precipitated with 8,8¾-diquinolyldisulfide (the oxidation product of 8-mercaptoquinoline) the precipitate separated on nuclear filters, followed by calcination and analysis of the concentrate. A method of electroconcentration was developed to measure trace elements in the suspended particle fraction of the water.The method consisted of capturing particles on an electrode in a constant electrical field.It was found that Fe, K, Mg and Mn were the main elements associated with the particle fraction although their contribution to the total concentration in water was <0.5%. The group reported that Si was the major impurity in the water samples, with high concentrations of Ba, Ca, Fe, Mg, Na and Zn in drinking water and concentrations of heavy metal impurities<1×10-8 mass%. Trace enrichment on an activated carbon column of Cd, Cu, Ni and Pb in drinking water was reported by Soylak et al.297 Drinking water (500 ml ) was adjusted to pH 6, mixed with 0.5 M 1-(2-pyridylazo)- 2-naphthol and, after 10 min, was applied to a column packed with 0.5 g activated carbon.The analytes were eluted with 10 ml 2 M HCl in acetone, the eluate evaporated to near dryness then diluted to 5 ml with 2 M HCl. This solution was limits were 12, 25, 59 and 43 ng l-1 for Cd, Cu, Ni and Pb, analysed by FAAS using an air-C2H2 flame.The detection respectively, with recoveries in the range 96-102%. Yaman and co-workers continued their work on trace 3 element preconcentration on activated carbon reported in previous years' Atomic Spectrometry Updates6 (refs. 244 and 245). Yaman and Gucer298 modified a previous method for the measurement of Al in animal milk and fruit juices by FAAS. The samples were wet ashed and quinolin-8-ol (oxine) and cupferron were used as complexing reagents for adsorption of the Al complexes on activated carbon.It was found that simultaneous enrichment of Al and Pb was achieved and both elements were measured by FAAS. Yaman also described the determination of Ni in vegetables by AAS following preconcentration by mixing with oxine or cupferron and activated carbon.299 A Chinese group used FAAS to measure Pb in soft drinks after preconcentration by coprecipitation.300 The sample (100 ml ) was neutralized, shaken with 2 ml 15% Mg(NO3)2 and 2 ml 20% NaOH for 1 min and stored for 1 h.The resulting precipitate was centrifuged, the supernatant discarded and the residue dissolved in HNO and diluted to 10 ml with H2O. Using the method of standard additions, plexation with ETDA to form negatively charged metal-EDTA recoveries of Pb were 90.5-112% with an RSD of 1.2-7.6%. 3 Two groups described flow injection preconcentration systems. Ivanova et al.301 developed a rapid and selective FI on-line sorption separation and preconcentration procedure for the determination of Bi in cod muscle, lake and river sediment by ETAAS.The diethyldithiophosphate complex of Bi was formed in 0.5-4% (v/v) HNO and adsorbed onto the inner walls of a PTFE knotted reactor. The complex was eluted with 30% (v/v) HCl and the eluate directly introduced into a pyrolytically-coated graphite tube without a pre-heating step. The ETAAS measurement of the concentrated analyte was carried out at the same time as the preconcentration cycle for the next sample.The enrichment factor was 74 and a detection limit of 3 ng l-1 was achieved with a sampling frequency of 28 h-1. The RSD was 3.4% for 0.1 mg l-1 (n=9) lake sediment and river sediment CRMs. A value of 14 ng g-1 and results were in good agreement with certified values for was found for BCR 422 (cod muscle). Enriquez-Dominguez et al.158 described their work on a FI preconcentration system with a chelating resin for the determination of trace and ultratrace amounts of Cd in mussels by FAAS.The metal was preconcentrated on a minicolumn packed with poly(aminophosphonic acid) resin and eluted with dilute HCl directly into the nebulizer-burner system of an FAAS. A preconcentration factor of 16-47, equivalent to a 3.4-10 ml sample, was in the sample was 0.56 mg l-1 for a sample volume of 3.4 ml achieved by using a time-based technique. The detection limit of Cd in the range 1-20 mg l-1.Chemical and flow variables and an RSD of 1.4-6.6% was obtained for diVerent amounts were studied and the system was found to be essentially unaVected by interferences. Good results were obtained for a CRM and the method was applied to the analysis of mussels from estuaries in part of Spain. 2.2 Speciation As in previous years, trace element speciation in a wide range of matrices has continued to attract considerable eVort.In a review with 41 references,302 Crews emphasised that studies on the speciation of trace elements in foods are required to better understand how the absorption and bioavailability of elements can be reduced for toxic elements, and improved for nutrients, and to validate existing risk assessment procedures for toxic elements. It was also pointed out that the methodology for speciation studies is still in the research and development stage, with few CRMs or standard procedures.Csikkel- Szolnok and Kiss303 investigated the Ca and Mg content of wheat, oats and barley and the uptake of these elements. Total Ca and Mg were measured by AAS following microwave digestion in HNO3. Uptake was apparently defined as the solubility of Ca and Mg following incubation at 37 °C for 1 h in both distilled H2O and in synthetic gastric juice (0.1 M HCl and pepsin). However, this reviewer considers that, since inorganic element absorption occurs mainly in the small intestine and not the stomach, it is unlikely that solubility of these elements under gastric conditions can be taken as an indicator of uptake, particularly if the authors intended uptake to indicate bioavailability of Ca and Mg from these foods.Total Ca in diVerent cereal products was approximately 10% of total Mg content, and it was reported that Ca solubility is lower than Mg solubility since Ca complexes are more stable.Not surprisingly, it was found that the solubility of Mg was 3-8 fold higher in HCl-pepsin than in distilled H2O. A conference presentation by Barnett and Horlick304 described the ability of ES-MS to diVerentiate between common valence states of Fe and V, and to measure metals traditionally regarded as 'problem elements' in ICP-MS, including Ca, Fe and Hg. Metal cations were determined following comcomplexes. This method had the added advantage of eliminating the oxide interferences between REEs commonly observed in ICP-MS.The authors used ES-MS to measure Ca levels in drinking water, a commercial Ca supplement and milk, and reported that results agreed well with those obtained by FAES. 3 Three groups have been working on the determination of Cr species in water and dairy products. Sahayam et al.305 measured CrVI in potable waters after selective separation of CrIII using ZnO.Water (250 ml ) was passed through a column containing 2 g of ZnO prepared by calcination of zinc nitrate; 2 ml HNO and 1 ml H2O2 were added to the eluate and the solution was evaporated to approximately 5 ml on a sand- ETAAS. The LOD for CrVI was 0.01 ng ml-1. The amount of bath. The residue was diluted to 10 ml and analysed by CrIII was calculated from the total Cr and CrVI values. A Slovakian group measured Cr in dairy products after preconcentration of CrIII on activated alumina at pH 7 in a flow system coupled online to an AAS instrument.306 Total Cr was determined after electrochemical reduction of chromate ions to CrIII, and both reduction and sorption were carried out in a combined cell containing a porous electrode made of glassy carbon particles coated with gold, a layer of the sorbent and 739 J.Anal. At. Spectrom., 1999, 14, 717-7812 the counter electrode in series. Lameiras et al.307 measured nedithiocarbamate in a medium buVered at pH 4.5 and total Cr and CrVI in UHT milk. Hexavalent Cr was separated extracted into hexane, then derivatized into volatile triin a procedure in which the proteins were precipitated and the phenylstibine, by Grignard reaction with phenylmagnesium supernatant was passed through a Chromabond NH column, bromide.A cool injection programmed temperature vaporizafter which CrVI was eluted with HNO3. Total Cr was deter- ation injector was used, and factors aVecting the extraction mined directly in the milk following addition of a surfactant and a Pd-Mg mixture as the chemical modifier, and both total Cr and CrVI were measured by ETAAS.Detection limits were 0.2 mg l-1 for total Cr and 0.15 mg l-1 for CrVI. Both procedures were validated by the standard additions method and recoveries were higher than 93%. Interference studies were undertaken using a simulated milk matrix to which total Cr and hexavalent Cr were added.The simulated milk was then separated and analysed by the procedures described and absorbance readings were interpolated on the calibration graph. It was concluded that there were no noticeable interferences from the principal constituents of total milk. Methods for the speciation of organotin were reported by 18 three groups. A Japanese team proposed a simple method for determining tributyltin (TBT) and triphenyltin (TPT) in hatchery fish.308 Extracts from the fish were concentrated and purified on an SPE column cartridge containing divinylbenzene-hydrophilic methacrylate copolymer.The sample was hydrolysed with a KOH-ethanol solution and the TBT and TPT compounds were extracted with petroleum ether. The petroleum ether was evaporated and the residue extracted in 50% ethanol solution and loaded onto the SPE cartridge. The column was washed with 10% methanol and the TBT and TPT eluted with HCl-methanol (1+9), then extracted with a hexane-cyclohexane mixture (1+1).After hydrogenation, derivatives of the extract were analysed by GC-quadrupole-MS. The LOD in the samples was estimated as 0.05 mg g-1 for TBT and 0.1 mg g-1 for TPT. Schmitt et al.155 described one- and two-stage procedures for the preparation of biological materials for speciation analysis of organotin compounds by GC-AES and GC-FPD. For the onestage procedure, 0.1-0.2 g of lyophilized material was microwave-digested at 40W power for 3 min at 130 °C with 5 ml acetic acid, 1 ml nonane and 3 ml 2% sodium tetraethylborate.The organic supernatant was analysed by GC-AES or GC-FPD after clean-up on alumina with diethyl ether as the eluent. For the two-stage procedure, the sample was microwave-digested at 50-60 W power for 3 min with 5 ml 25% TMAH. The solution was diluted to 15 ml with H2O, adjusted to pH 5 with acetic acid and extracted with 1 ml 2% sodium tetraethylborate and 1 ml nonane for 5 min.The organic phase was separated and analysed for Sn species. A DB-210 column was used with AES detection and an HP-1 column with FPD. Both methods were validated by analysing a reference fish tissue. Detection limits were 2-10 and 20-40 ng g-1 for AES and FPD, respectively. The one-stage method was applied to the analysis of mussels and sea urchin eggs. A conference report309 described the development of an LC method for the separation of dibutyltin (DBT), TBT, diphenyltin (DPT) and TPT, which is compatible with both ICP-MS and atmospheric pressure ionization (API )-MS.The chromatographic system comprised a Kromasil-100 5 mm C column and a mobile phase of 0.05% triethylamine in acetonitrile-acetic acid-H2O (65+10+25) at a flow rate of 0.2 ml min-1. The system was reported to be compatible with both ICP-MS, which oVers superior sensitivity, and API-MS, which provides intact molecular ion information on the organotin compounds.The development work was carried out on fish tissue and sediment CRMs. Two papers reported advances in the speciation of Sb. A method was described for the selective determination of SbIII in the presence of SbV in spiked tap water by GC-quartz furnace-AAS following derivatization with triphenylmagnesium bromide.310 Trivalent Sb was complexed with pyrrolidi- 740 J. Anal. At. Spectrom., 1999, 14, 717-781 and derivatization conditions, the operating conditions for the quartz furnace and the injector were all optimized.Zhang et al.311 used a miniaturized HPLC column coupled to HGAAS for the speciation of inorganic SbIII and SbV species in spiked water samples. The two Sb species were separated by using 50 mM tartrate solution at pH 5.5 as eluent, and the retention times were 0.5 and 2.8 min for SbV and SbIII, respectively. The hydrides were generated with 3% NaBH4 and 1.8 M HCl solutions.The detection limits achieved were 1.0 and 2.0 mg l-1 for SbV and SbIII, respectively. The author emphasises that to the EU drinking and surface water limits (10 mg l-1), but these LODs are adequate for screening samples with respect are not suYciently sensitive to measure real levels in natural waters. It was also noted that there is as yet no suitable CRM available. Bra�tter and co-workers have used speciation as an analytical aid in trace element research in infant nutrition.38 They studied the binding pattern of trace elements in formula milk as compared with breast milk and the relationship between trace elements in breast milk and maternal dietary intake. Protein separation by HPLC was coupled on line with ICP-MS or ICP-AES for simultaneous speciation to investigate the binding forms of the nutritional elements Ca, Co, Cu, Fe, I, K, Mg, Mn, Mo, P, S, Se and Zn, as well as the heavy metals Cd and Pb.Size exclusion chromatography minimized interactions between the labile metal protein complexes and the column material. It was reported that the binding pattern of trace elements in infant formulae was significantly diVerent from that in breast milk, and was dependent on whether its major component was cows milk or soy, its processing and the chemical form of the added compounds. An investigation of breast milk samples from diVerent regions of the world showed comparable elution profiles and, for Mo and Se, a dependence on the regional maternal dietary intake.Interestingly, the group found significant changes in the Zn-binding pattern as a function of the Se content of breast milk, and citrate was found to decrease with increasing maternal dietary Se intake. It was also noted that formula-fed infants received much higher levels of Fe than breast-fed babies, and the binding forms of Fe were very diVerent in the two milks, which poses an interesting question as tohe relative bioavailability of Fe in these foods which hopefully will be addressed in the near future.Several applications of HPLC separation with detection by ICP-MS and ICP-AES have been reported in conference presentations. It is to be hoped that these contributions to a developing area of research will be published in full. Bantan et al.312 used anion exchange FPLC-ICP-AES for speciation of negatively charged low molecular weight organic complexes of Al.Separations were carried out on a Mono-Q strong anion exchange FPLC column over a wide pH range (3-11) using linear gradient elution (0-100% 4 M NaNO3). Characteristic retention times were 5.5 min for Al-citrate, 6.0 min for Al-oxalate and 2 min for Al-EDTA. The separated Al species were determined in 0.5 ml eluate fractions by ICP-AES. Kos and Hudnik313 described a procedure for the isolation and determination of Cd species in endive grown in Cd-enriched nutrient solution.The Cd species were extracted from the endive with Tris-HCl-phenylmethylsulfonyl fluoride. The clear supernatant was passed down a Sephadex G-50 column which was coupled to ETAAS for on-line Cd measurement. Two fractions were obtained, the first one of which was identified as Cd bound to a high molecular weight protein. The authors suggested that the second Cd fraction consisted of ionic Cdand Cd bound to polypeptides, and discussed some approaches for the examination of this fraction.It is to be hoped that these approaches will be published. Yasui Akemi described a laboratory-built interface for ICP-AES to increase the transfer eYciency of sample solutions.314 The interface, consisting of a thermospray nebulizer, spray chamber and condenser, was used in conjunction with HPLC columns, Shodex IC I-524A and Tosoh G3000SWx1 for the separation of P compounds and Fe compounds, respectively.The P compounds were a mixture of polyphosphonic acids and phytic acid (IP6) hydrolysate with HCl, and ferritin, hemoglobin and iron(II) sulfate were used for the Fe separation. The sensitivity of the ICP-AES using the interface was increased by up to 30 times compared with a conventional concentric nebulizer. Szpunar and colleagues315 used a rapid SEC-ICP-MS method requiring minimal sample preparation to study Pb speciation in 20 wine samples.They reported that Pb was not present in the mineral form, used for assessment of toxicity, but was mostly associated with a biomolecular species (ca. 10 kDa), identified as the dimer of a pectic polysaccharide, rhamnogalacturonan II. Other minor Pb complexes in the range 500-3000 Da were not identified. In a conference presentation Szpunar316 described two separation techniques, SEC and reversed phase chromatography (RPC), for studying protein-bound metals based on the coupling of HPLC with ICP-MS.The tolerance of neuroblastoma cells to Al was studied with SEC-ICP-MS. Two Al-containing low molecular weight (6-8 kDa) compounds were identified in the cytoplasm of neuroblastoma cell cultures which accounted for all the Al in sample. Another application of SEC-ICP-MS investigated the binding of metals by wine proteins, polysaccharides and smaller molecules. Examples of Cd, Cu and Zn associated with metallothioneins were shown, and the bi-dimensional SEC-RPC-HPLCICP-MS speciation analysis of metallothioneins was discussed.Finally, Magnuson et al.317 coupled capillary electrophoresis (CE) to HG-ICP-MS with on-line reduction (OLR) for the determination of four arsenicals and two Se species. Selenate (SeVI) was reduced on-line to SeIV by mixing the CE eZuent with concentrated HCl. A microporous PTFE tube was used as a gas-liquid separator to eliminate the 40Ar37Cl and 40Ar35Cl interferences from 77Se and 75As, respectively.Detection limits for SeIV and SeVI for conventional pressure injection were 10 and 24 pg, respectively. The direction of the electroosmotic flow during CE could be reversed with hydrodynamic pressure, thus allowing increased freedom of buVer choice. The authors reported that dual detection of CE-speciated As and Se compounds had been demonstrated, but emphasised that further investigation was necessary to verify the use of the CE-OLR-HG-ICP-MS system for simultaneous determination of As, Se and other hydride forming species.It is anticipated that the coming year will produce more applications of CE coupled to atomic spectrometry detectors for elemental speciation. 2.3 Developments in methodology for flame atomic absorption spectrometry A method was described for the direct determination of Fe and Zn in cows' milk by FAAS with a high performance nebulizer.318 Samples of whole milk, non-fat milk and whey were analysed without chemical treatment, using a nebulizer comprising a tantalum capillary and ceramic impact bead positioned to optimize nebulization eYciency.Increased sensitivities were reported for both Fe and Zn, with LODs of 0.024 and 0.007 mg ml-1, respectively. The accuracy of the procedure was studied by analysis of non-fat milk CRMs and the method was applied to ten cows' milk samples.Zhang et al.319 reported a method for the determination of Cd by derivative FAAS with a modified water-cooled stainless-steel atom trapping tube in an air-C2H2 flame. The laboratory-made derivative measurement system and atom-trapping equipment, previously described, gave a detection limit and sensitivity improved by FAAS. The LOD (3s) for Cd was 0.02 mg l-1, with a recovery two and three orders of magnitude over those of conventional range of 85.9-114%.The method was applied to measurement of Cd in vegetable samples. 3 Three groups reported FI analysis systems coupled to FAAS. Shuai et al.320 described on-line determination of Pb in rice flour and bee chrysalis (honeycomb?). The sample was digested to dryness with HCl-HNO3, the residue taken up in 1 ml of HNO and diluted to 25 ml with H2O. An aliquot was mixed with 2 ml HCl (1+1), H2O added to 10 ml, plus 5 ml 200 g l-1 KI and made up to 25 ml with H2O.A 7 ml portion was injected into the FI equipment for on-line extraction in a coil with 250 ml of IBMK, followed by separation in a phase separator (diagram shown). The extract was transferred in an sampling frequency was 45 runs h-1 and the LOD was H2O carrier stream for Pb measurement by FAAS. The 2.8 ng ml-1, with RSD (n=11) of 2.5%. Xu and Chen321 dissolved 10 g of cooking salt in 100 ml of 1% HCl. Following further dilution, 150 ml was injected into an FI system (diagram given) in a water carrier before nebulization into the slotted tube atom trap for FAAS determination of Ag, Au, Cd, Co, Cu, Fe, Mn, Ni, Pb, Pd, Sb and Zn.The system was optimized with PTFE tubing (17 cm×0.5 mm id) for linking the sampling valve and nebulizer, and the distance between the slotted tube and 5 cm burner was 3 mm. Sensitivity was enhanced 1.2-3.3-fold compared with conventional FAAS, and the usable lifetime of the slotted tube also increased. The method was applied to water samples, with a sampling frequency of 240 runs h-1, and recoveries for Cd, Cu, Mn and Pb were 90-110% by the standard additions method.A sequential injection (SI ) system was coupled with FAAS for the determination of Ca and Mg in mineral water.322 The SI system comprised a 6-position valve, 3-way solenoid valve and a peristaltic pump fitted with 1.6 mm id PVC tubing. The holding coil was constructed with PTFE tubes (0.8 mm id×200 cm length) coiled on a rod with 1.5 cm od.The FAAS detector was connected to one of the ports of the 6-position valve through a polyacryl confluence device. Small volumes of sample (ml ) were injected into the holding coil between two slugs of 100 mM La. The flow was then reversed and the coil contents were introduced into the air-C2H2 flame. It was reported that interferences were eliminated when La solution frequency was >110 h-1 and reproducibility was better than was injected before and after each sample.The sampling 3%. The method was applied to 15 samples of mineral water and results were compared with conventional AAS analysis. 2.4 Developments in methodology for electrothermal atomic absorption spectrometry Applications of ETAAS with a transversely heated graphite atomiser (THGA) were described in two papers. Subramanian et al.168 developed a procedure for determining low levels of Sb (mg l-1) in water and blood.The method was based on the concept of STPF atomization by using a THGA furnace, longitudinal Zeeman-eVect background correction and matrix modification with Pd(NO3)2-Mg(NO3)2-HNO3. The method did not require the use of standard additions and the LOD (3s of the blank) was 2.6 mg l-1. The THGA-AAS method was reported to be simple, fast and contamination-free because the entire sampling operation was carried out in the same tube.The direct determination of Pb by ETAAS with endcapped THGA was described by a Brazilian group.323 Sweet fruit-flavoured powder drinks, honeys and syrups were analysed without sample digestion and without air-ashing during the pyrolysis step. Samples (4 g) were completely dissolved in 741 J. Anal. At. Spectrom., 1999, 14, 717-7812% lactalbumin. The LODs were 400, 26, 20 and 280 pg, respectively, and results were presented for nine samples of diVerent milk types.2 H2O, acidified and the volume made up to 50 ml to give a of 3%, 6% and 15% H2O2, 1% HNO3, 0.1% phosphate and sugar content of 8%. Aliquots of these solutions (20 ml ) with 10 ml of chemical modifier solution were delivered directly into the end-capped THGA atomizer. For sugar content higher than 8.0%, a build-up of carbonaceous residue inside the Finally, Bettencourt da Silva et al.327 validated the unceratomizer was observed and tube lifetime was reduced (100 tainty evaluation for the determination of metals in solid firings at 16% sugar, compared to 240-260 firings at 8% samples by ETAAS.Lettuce leaves were dried at 60 °C and sugar). Several matrix modifiers were tested and their eVect 200 mg of the dried material was microwave digested with on sample throughput and recovery investigated. The modifier HNO3. Concentrations of Mn in the digests were determined selected [0.05% (m/v) Pd+0.03% (m/v) Mg(NO3)2] increased by ETAAS using a Pd-Mg chemical modifier and D backsample throughput by a factor of 2 and gave recoveries of 90.2-106% with an RSD <5.9%.The LOD of 7.0 ng g-1 Pb ground correction. Assuming 100% digestion eYciency and following the recommendations given in the Eurachem guide attained the Food Chemical Codex recommendation for the ('Quantifying uncertainty in analytical measurement', Version maximum allowed Pb concentration in sugar samples. Imai 6), total analytical uncertainty and uncertainties associated et al.324 examined the eVect of coating a pyrolytically coated with each experimental operation were evaluated.A repeatgraphite furnace with hafnium, niobium, tungsten and zir- 0.82 mg kg-1 lettuce (9 degrees of freedom) against an esti- conium on the injectable sample volume in order to enhance ability test revealed a method uncertainty for Mn of the sensitivity of Pb determinations. Treatment with W was mated uncertainty of 0.73 mg kg-1 lettuce (57 500 degrees of found to give high precision (RSD <3%) for a 100 ml injection freedom) with 95% confidence.Analytical accuracy was of sample solution and good linearity was observed between assessed using spinach leaves treated by a similar method. integrated absorbance and sample volume in the range 0-100 ml. Using a Pd modifier enhanced precision (RSD<2%) 2.5 Developments in methodology for inductively coupled and stability of the integrated absorbance (RSD <2.5%) for plasma mass spectrometry up to 250 firings.The calculated detection limit and characteristic mass (sensitivity) were 0.02 mg l-1 and 12 pg, respectively, for a 100 ml injection with Pd modifier at the optimum ashing temperature of 1400 °C. An interference study was performed and the method was applied to water samples. Chemical modifiers were studied by two groups. A Japanese The popularity of ICP-MS for a wide range of applications has continued during the past year, but the majority of contributions to the literature on this topic has unfortunately appeared as conference presentations, and it is to be hoped that detailed papers will be forthcoming.A conference report by Robb328 described ICP-MS as an invaluable tool for the measurement of trace elements in food. An overview of a wellestablished approach to determination of total element concentrations in food was presented together with the measures required to ensure production of quality multi-element data. The key issues of data handling and results presentation were group investigated the eVect of Ni(NO3)2 as a matrix modifier on the determination by ETAAS of low levels of In in infant formulae and human milk.209 Twice-concentrated samples (400 ml ) were diluted with 200 ml of 4% (w/v) Triton X-100 and 200 ml of H2O.A 10 ml portion of the diluted sample was 5000 mg l-1 Ni in 1 M HNO was injected and the sample was injected into the furnace and dried. After cooling, 10 ml of 3 3 Excellent linearity, stability, spike recovery and detection limits were reported.Information on Pb intake from Ca supplements atomized. Detection limits were 2 and 2.5 mg l-1, with mean emphasised and examples of complex data sets given, with results from several types of investigation. Baxter et al.329 In recoveries of 97.2% and 95.4% in infant formulae and breast milk, respectively.The RSD was 2% at the 50 mg l-1 investigated long term accuracy and precision of multi-element measurements by ICP-MS. Their conference presentation dealt level. Karadjova et al.325 proposed a simple and fast procedure with the behaviour of CRMs measured over two years during for the direct ETAAS determination of Al, Cd, Cr, Cu, Fe, large multi-element surveys (29-36 elements determined in test Mn, Ni and Pb in olive oil.A universal modifer, N,N- samples) of total diet samples, health foods, fish, and snack hexamethylenedithiocarbamic acid hexamethyleneammonium and convenience foods. It was reported that achievable accusalt (HMDC-HMA), was used which had two functions: racy and precision during multi-element measurements varied isoformation of diVerent chemical species of metals present in with element and with concentration. Data were presented olive oil and their thermal stabilization during the pretreatment from analyses by a VG PlasmaQuad 2+ Turbo and a Perkinstep.Various organic solvents (diethyl ether, IBMK, xylene, Elmer Elan 6000. heptane and 1,4-dioxane) were studied as solvents for olive oil Two conference presentations described the determination dilution. It was reported that 1,4-dioxane was the most suitable of Pb by ICP-MS in calcium dietary supplement pills in since it improved the decomposition of triglycerides during to Pb in Ca supplements to 0.5 mg d-1.Sharma et al.150 the pre-treatment step so that aqueous standard solutions response to California Proposition 65 which limits exposure could be used for calibration. Uncoated graphite tubes with described the diYculty in measuring trace metals in Ca-rich platforms were selected as atomizers for the determination of matrices such as over-the-counter Ca supplements, which are Cd, Cu, Fe, Mn and Pb, and pyrolytic graphite coated tubes either derived from natural inorganic CaCO sources such as with grooves were most suitable for Al, Cr and Ni. The paper dolomite, oyster shell, bonemeal, or Ca chelated to organic presents instrumental parameters optimized according to pre- matrices such as gluconate or lactate.Total Pb and Pb isotope treatment and atomization curves, obtained in the presence of ratios were measured in nine supplements by ICP-MS followthe olive oil matrix and with HMDC-HMA as modifier.The method permitted the determination of 0.1 mg g-1 Fe, ing high pressure/temperature acid digestion. Matrix matched 0.05 mg g-1 Ni, 0.02 mg g-1 Al, Cu, Cr and Pb, and 0.01 mg g-1 Pb calibration standards were prepared in high purity CaCO3, and satisfactory recoveries were reported for Ca in an animal Cd and Mn with RSDs of 8-10% for all analytes in this bone SRM. Supplements containing natural Ca sources had concentration range. Vinas et al.326 established optimum con- 8-28 mg Pb per gramme of calcium whilst chelated or refined ditions for the determination of Al, Cr, Mn and Mo in cows' Ca supplements contained 1-2 mg Pb per gramme of calcium.milk, human milk and infant formulae by ETAAS following Source identification by Pb isotope ratios was investigated. A dilution in suspension media specific to each element. Dried similar procedure was proposed by Bakowska149 involving formula milk was dispersed in 25 ml of an aqueous-20% acid digestion followed by ICP-MS analysis against standards C2H5OH suspension medium whilst liquid samples were and a standard blank prepared in CaCO3 of known Pb value.diluted as necessary. For the determination of Al, Cr, Mn and Mo, the suspension media also contained various combinations 742 J. Anal. At. Spectrom., 1999, 14, 717-781was reported. Almeida and Gine�330 described the determination of Pb in vegetables by ID-ETV-ICP-MS. Sample introduction by vaporization from metallic, rather than graphite, surfaces was proposed to replace pneumatic nebulization.Direct nebulization was used to optimize Pb isotope ratio signals for aqueous standards by ICP-MS prior to installation of a tungsten coil (TC)-ETV furnace. The TC was mounted inside a glass chamber which was connected directly to the plasma torch using a tube (7 mm id×750 mm long). A gas mixture of 95% Ar-5% H2 transported the vaporized sample at 1.5 l min-1 to the plasma.It was reported that digested biological samples in a strongly acid medium damaged the tungsten coil, and that best precision was obtained by measuring isotope ratios. The most accurate quantification of Pb by TC-ETV was therefore obtained by ID. It was unclear whether the disadvantages and complexity of using TC-ETV, as opposed to direct nebulization, were really outweighed by the possibility of using minimal volumes (20 ml ) of a very concentrated digest solution, particularly for an RSD of 1-2.5% 100 mg l-1 Pb solution.obtained for 208Pb5207Pb isotope ratios measured in a 2O. The resulting solution was adjusted to pH 0-0.5 with Mestek.334 The sample (25 ml ) was acidified, heated to expel 2, cooled and treated with 1 ml of 0.0005% Y as internal 3, 500 ng Re added as internal standard, known additions were 100-106%, with an RSD of 3.2%. Using A method was reported for measuring ultra-trace elements by coupling IC to ICP-MS.Cao et al.331 described an involved procedure for measuring very low levels of REEs in tea. Samples (0.2-0.3 g) were microwave digested in capped vessels with a mixture of HNO3, H2O2, HClO4 and HF using a threestage programme, repeated three times. After cooling, the digests were washed into Teflon beakers and the solutions from two samples were combined, evaporated to near-dryness and the residue taken up in 1 ml of HNO3 and a few drops of HNaOH for chromatographic separation.The sample solution was then loaded onto a glass column packed with cation exchange resin and the alkaline metal elements were washed out with 1.75 M HCl, followed by the alkaline earth elements in 2 M HNO3. After rinsing the column with H2O and 5 M HNO3, the REEs were eluted with 5 M HNO3 (30 ml ), the fraction collected and evaporated to near dryness. The residue was dissolved in HNO and diluted to 25 ml with H2O prior to analysis by ICP-MS.as polyatomic BaO+ and BaOH+ interference with Eu. It was reported that the method eliminated matrix eVects, such Detection limits were between 0.0039 and 0.0003 ng ml-1 for REEs in solution, with spike recoveries from 90-105% and precision <9% RSD. Two conference reports were used to present work on trace element determinations by quadrupole (Q)- and high resolution (HR)-ICP-MS. Kishiki et al.68 measured 25 elements in an animal tissue SRM by a combination of conventional and HR-ICP-MS.Samples were prepared by microwavepowered digestion in high purity HNO3. It was reported that following reduction to the trivalent state with KI-ascorbic results obtained by HR-ICP-MS agreed well with certified values for all elements except P, Pb and V. Results for Al were lower than the indicative value, probably due to incomplete solubilization. A detector saturation problem was reported for P, and a high background was noted for Ni due to the Ni sampling cone.More detailed investigation for Pb and V was considered necessary. There was some discussion of preliminary work on interferences, both for Q-ICP-MS and HR-ICP-MS. Stu�rup and Larsen described methods for the determination of As, Cd, Cr, Cu, Hg, Ni, Pb, Se and Sn in mussels using either Q-ICP-MS or HR-ICP-MS.332 It was reported that throughput was faster with the Q-ICP-MS since the quadrupole could be scanned faster than the magnet of the HR-ICP-MS instrument.However, HR-ICP-MS showed better signal to noise ratios and therefore had better LODs. The report described the diYculties of measuring As, Cr, Cu, Ni and Se by Q-ICP-MS due to interferences by polyatomic ions. Using HR-ICP-MS, it was possible to resolve the analytical peaks with a resolution setting of 4000 for Cr, Cu, Ni and Se, and 10 000 for As. The results obtained for these elements were in good agreement with certified values of a mussel tissue SRM.It was also possible to identify the polyatomic interferences originating from the sample matrix, and this information could be used to set up correction equations for the Q-ICP-MS. The authors concluded that the most accurate and precise results were obtained by HR-ICP-MS but that the data were obtained at a considerably higher cost, since the instrumentation is more expensive and the sample throughput is lower.Publication of this work in full will make a valuable contribution to the literature on the relatively new technique of HR-ICP-MS. 2.6 Progress in individual elements 2 4 4 2.6.1 Arsenic. Methods for the determination of total As were described by two groups. Madrid et al.333 characterized AFS in conjunction with FI-HG for measurement of As in untreated samples of beer and wine. Several parameters were evaluated for each sample type, including HCl and NaBH4 concentrations and Ar and H flow rates.Optimum conditions were selected as 6 M HCl and 0.5% NaBH for beer and 6 M HCl and 1% NaBH for wine. Three mineralization techniques were tested, and comparison of results for untreated and mineralized samples showed no significant diVerence at the 95% confidence level. It was reported that the method was levels of 2 mg l-1 in wine. A method for determination of As fast, accurate and sensitive and could be used to quantify As in high-saline mineral waters by ICP-MS was described by CO standard and 2 ml CH3OH, then diluted to 50 ml. It was from 40Ar35Cl+ by up to 70%, and the remaining interference reported that the inclusion of CH3OH reduced the interference was corrected for on the basis of the signal ratio of 35Cl+ to 40Ar35Cl+, which was constant over the range 0.4-1 g l-1 Cl.An LOD of 30 ng As l-1 was achieved and recoveries of a calibration graph and the method of standard additions, concentrations of As in a mineral water sample were 1.50 and 1.44 mg l-1, respectively, compared with 4.2 mg l-1 when no correction was applied.Techniques for the separation of arsenite (AsIII) and arsenate (AsV) were reported by three groups. Pozebon et al.335 used an FI procedure for the separation and preconcentration of inorganic As based on complexation with ammonium diethyl dithiophosphate (DDTP) and sorption on a C18 bonded silica gel mini-column. Total As in water samples, a CRM and synthetic mixtures of AsIII and AsV was determined by ETAAS the As3+-DDTP complex was stripped from the solution and acid.Sample aliquots were loaded onto the mini-column and retained on the column, whilst other ions and AsV which did not form complexes were discarded. When 6 ml sample had been loaded onto the column, As3+-DDTP was eluted directly into an autosampler cup (120 ml ), and 0.1% Pd(NO3)2 added as a chemical modifier for measurement by ETAAS.The concentration of AsV was determined by diVerence. Good recoveries of spike were reported (97-108%), and total As concentration was in agreement with the certified value for the SRM. Preconcentration time was 120 s, and 20 samples h-1 could be processed. The LOD for AsIII was 0.15 mg l-1. An analytical method for the determination of AsIII and AsV in natural drinking ws was reported in a conference presentation.336 Solid phase extraction cartridges were used as a low pressure column for separation, with HGAAS and HGAFS for As detection.The best results were obtained using an anion exchange cartridge and 20 mM phosphate buVer at pH 7, 743 J. Anal. At. Spectrom., 1999, 14, 717-781and cation-exchange columns, with mobile phases of phosphate buVer of pH 6 and 10 mM HCl, respectively. The anionexchange column separated AsIII, DMA MMAand AsV, whilst AB and tetramethylarsonium (TETRA) ion were separated on the cation-exchange column, with trimethylarsine oxide (TMAO) and arsenocholine (AC) co-eluting. The As species were oxidized with K reduced to hydrides with NaBH4. The hydrides were carried in Ar to a drying unit and detected at 193.7 nm by AFS.The 2S2O8 with 254 nm radiation, then 2O LOD was 0.5 ng ml-1. For simultaneous GC separation, samples (100 ml ) were reduced with NaBH4 at pH 6, the AsH3 from AsIII trapped on a short column of Chromosorb W AW-DMCS cooled with liquid N2, and thermally desorbed 2 with a step gradient of 5 mM Na2B4O7 (pH 9) for elution of Samples for HPLC analysis were applied separately to anion AsIII and 0.1 M NaHCO AsIII and AsV as low as 2 mg ml-1 were separated within 3 (pH 9) for AsV.Concentrations of 1.2 min, and no interferences were observed from Cd, Cu, Ni or Pb at these concentrations. Higher levels of FeIII aVected AsV detection.Helgesen and Larsen337 investigated the bioavailability and speciation of As in carrots grown in uncontaminated plots and soil contaminated with As and Cu. The As species were extracted from the soil for 1 h by gently shaking dried samples in a 1 mM Ca(NO3)2 solution, centrifugation and separation of the supernatant. A CH3OH-H (1+9) solution was used to extract As from dried carrots with gentle microwave heating. Using a referenced method, extracts were injected onto an anion exchange column and eluted isocratically in 45 mM ammonium carbonate+H O-CH3OH for separate AFS analysis.Calibration graphs were linear up (97+3) solution at pH 10.3 directly into an ICP-mass spectrometer. Although the system was characterized by injecting aqueous standards of MMA, DMA, AsIII and AsV, only AsIII and AsV were detected in the samples. The soil-to-carrot uptake rate (bioavailability) was reported and dietary intakes from the carrots assessed.An interesting conference presentation by Heitkemper et al.338 reported that most of the As in carrots exposed to an organic arsenical defoliant (dimethylarsinic acid) was not inorganic AsIII or AsV. Both IC-ICP-MS and HPLC-ES-MS were used for the identification and quantitation of the major As species found. Results were obtained for total and speciated As, which were compared with those obtained for control samples. Full publication of this work will be a welcome addition to the literature.Lamble and Hill23 described the development of a method capable of the separation of As species by on-line HPLC prior to their on-line decomposition by microwave digestion, pre-reduction with Lcysteine and analysis by HGAAS. Full speciation of AB, MMA, DMA and total As (AsIII+AsV) was achieved in biological samples. to 10 ng in a 100 ml sample, with an LOD of 0.25 ng. The same team used a conference presentation to describe As speciation in wine and urine using HPLC-AFS.343 A novel interface between HPLC and AFS was proposed which comprised photooxidation in the presence of persulfate of the HPLC eZuent followed by HG of the decomposed As compounds.Hydride-forming compounds only (AsIII, AsV, MMAA, DMAA) were detected without on-line decomposition, but UV-decomposition permitted measurement of nonhydride-forming compounds (AB, AC, TETRA, TMAO). Determination of As compounds by ion-pair chromatography was described by van Elteren and Slejkovec.344 Samples were injected onto a cation-exchange column, with 5 mM 3-carboxy- 4-hydroxybenzenesulfonic acid at pH 1.9 as mobile phase, photochemical oxidation with 4% potassium persulfate in 3% NaOH and an 8 W 254 nm UV lamp.Hydride generation was performed in a PTFE mixing coil with 4 mM HCl, 1.5% NaBH4 in 0.1% NaOH, and As detection was by AFS. The method was used to investigate the eVect of food treatment processes (boiling, microwave heating, c-radiation and dry heating) on the stability of As compounds.Partial decomposition was observed for c radiation and dry heating, but it was reported that no health hazards were expected. Two groups reported work on inorganic and organic As compounds in mushrooms. Larsen et al.339 investigated As species in an edible mushroom, Laccaria amethystina, collected from contaminated and uncontaminated locations.The As Finally, Pergantis et al. reported the characterization of species were extracted from the samples using focused micro- arsenosugars by FAB-tandem-MS.345 Arsenosugars are of wave digestion and separated and detected by anion and cation particular interest because they are present in relatively high exchange HPLC with As detection by ICP-MS. Total As concentrations were 23 and 77 mg g-1 (dry weight) in mushconcentrations in seaweed food products, and their biochemisrooms from two uncontaminated sites and 1420 mg g-1 in the try requires further investigation.FAB was used for the eYcient generation of gas-phase ions of the various arsenocontaminated sample. The total As comprised 68-74% DMA, sugar compounds, and these were used to provide structural 0.3-2.9% methylarsonic acid, 0.6-2.0% trimethylarsine oxide, information for characterization of an arsenosugar present in 0.1-6.1% arsenic acid, and the unextractable fraction of As partially purified algal extract.ranged between 15 and 32%. It was reported that mushrooms or their bacteria were able to biosynthesise DMA from arsinic 2.6.2 Iodine. There has been an upsurge in activity this year acid in the soil, and AB, trimethylarsine oxide and other in developing methods for the determination of I. Fecher unidentified As species were detected for the first time in et al.346 described the measurement of I in food samples by Laccaria amethystina.This agrees with work originally ICP-MS after alkaline extraction. A 1 ml volume of TMAH reported in last year's ASU340 (ref. 275), and further described was added to the sample (200-500 mg dry+5 ml H2O, or this year in a conference presentation,341 which reported the 2-3 g wet sample). The sample vessel was closed gas-tight and finding of AB, previously only found in marine biota, in three heated in a dry oven at 90 °C for 3 h. The cooled sample was fungus species.This group extracted Laccaria amethystea and diluted to 25 ml with H2O and any undissolved particles three other wild-growing mushrooms into boiling bi-distilled removed by centrifugation and/or filtration (0.45 mm) to avoid H2O and determined the As compounds by HPLC-ETAAS blocking the nebulizer. After addition of Te as the internal and HPLC-ICP-MS. The mobile phase for HPLC-ETAAS standard, the solution was measured directly or following was 0.003 M potassium hydrogenphthalate solution saturated further dilution.The LOD (9s of the blank) was 30 ng g-1 with Ni(OH)2, and 0.03 M sodium dihydrogenphosphate at for a 100 mg dry sample mass. The method was applied to a pH 6 was used for ICP-MS detection. It was reported that 97% of the As in Laccaria amethystea was present as DMA with 3% as AsIII, with various distributions of diVerent As species in other mushrooms. Two papers and a conference presentation described 4 3 round-robin test on two dietetic child nutrition food samples artificially enriched with I.It was reported that all the I present was extracted completely by the TMAH digestion, and the results compared favourably with those obtained by TMAH-ID, GC, HNO -HClO decomposition and photometric techniques. The TMAH procedure was adopted as a German reference method for determination of I in dietetic foods. Radlinger and Heumann347 compared results for I methods for As speciation with detection by AFS.Slejkovec and van Elteren342 developed a dual As speciation system combining LC and purge and trap GC separation with AFS. 744 J. Anal. At. Spectrom., 1999, 14, 717-781measured by ID-ICP-MS in SRMs (three milk powders and bovine liver) following TMAH digestion (3 h at 90 °C) with those obtained following microwave digestion in HNO3-H2SO4. All digests were diluted with 25 ml H2O for acetic acid-sodium acetate, H2O and 10 g l-1 sodium tetrameasurement of the 127I5129I ratio.The detection limit was reported as 8 ng g-1 for a 0.8 g sample with RSD of 0.6-2.8% ethylborate in 20 g l-1 KOH, and the generated ethylmethylfor 0.1-5 mg g-1 I. Ge�linas et al.210 measured total I in mercury was adsorbed onto a 1.5 cm Tenax trap using N The Tenax tube was connected to a GC system, and the nutritional and biological samples by ICP-MS. The samples ethylmethylmercury was desorbed by heating at 220-250 °C were combusted in a stream of O2, and the combustion for determination on a 15% OV-3 column linked to a 3% products collected in a 5% water-soluble tertiary amine solu- OV-3 guard column with He as the carrier gas and Hg tion.Good agreement with certified I values was obtained for detection by AFS. The LOD was 0.5 pg Hg. six CRMs, although low-level I contamination was present in An interesting paper by Moreton and Delves described a the blank.It was reported that the method was also suitable for the analysis of other trace elements, including Cd, Co, Cu, Mn, Ni, Rb, Pb and Zn. In a conference presentation, Petersen and Larsen348 pro- 3 posed an acid-digestion method for preparing samples for I analysis by ICP-MS, which would overcome the problems of memory and losses during wet ashing caused by the volatility of I species. The sample was placed in a Teflon liner with during which time ashing occurred and I- was oxidized to HNO and HClO4, then pressure-digested for 4 h at 160 °C, in control blood and control urine, and blank samples were prepared by the same method.Samples of fish were cut into 3-. After dilution with H2O, the sample was analysed by small pieces, to which internal standard (Tl ) and concentrated ICP-MS and I as I+ was measured at m/z 127. It was reported IO that blanks were contaminated with I from the Teflon liners, which required rigorous cleaning with TMAH and monitoring prior to analysis to ensure low LODs (5 ng g-1 fresh weight).The LOD was improved by 50% by adding 3% CH3OH to the analyte solutions and increasing the plasma power to 1200 W, due to signal enhancement by introduction of C into the ICP. Calibration was by standard additions to overcome matrix eVects, and the method was applied to measuring I in milk, milk products and fish. 2.6.3 Mercury. As noted in previous years, most of the activity on Hg analysis in this review year has been concentrated on developing methods for the measurement of total Hg.Manzoori et al.349 described a technique for the determination of Hg by CVAAS after preconcentration with dithizone immobilized on surfactant-coated alumina. Both inorganic and methymercury cations were adsorbed from aqueous solution onto a column packed with dithizone immobilized on sodium docecylsulfate coated alumina beads. The trapped Hg was back-extracted into the aqueous phase with 1 M HBr and determined by CVAAS following reduction with NaBH4.Methylmercury and HgII cations were completely recovered from water, with a preconcentration factor of 100. Venthe and Boewe350 reported improved detection limits for Hg determination by conventional HG-ETAAS. Platinum group metals, particularly Ir, can bind metal hydrides and an Ir-coated graphite tube was used to concentrate hydrides of Hg prior to atomization and measurement by ETAAS.The method was also applied to As, Bi, Sb and Se, and LODs of 0.03-0.08 mg l-1 were reported as about one order of magnitude lower than by conventional HGAAS. An automatic mercury analyser (AMA-254) was used for the determination of organic Hg in fish samples.152 Samples were extracted with toluene and then treated with cysteine solution (1% L-cysteinium chloride in 12.5% anhydrous sodium sulfate, 0.775% sodium acetate).After shaking and centrifugation, the solution was analysed by the AMA-254: the solutions were heated and the decomposition products were passed through an amalgamator which collected Hg0. The amalgamator was then heated and the Hg released for measurement by AAS. The instrumental LOD was 0.01 ng Hg, and it was reported that good reproducibility and recovery for CRMs were achieved, especially if a re-extraction step was performed. Methylmercury was measured in fish, shellfish and environmental samples by GC-AFS after aqueous phase ethylation.351 The sample was decomposed in ethanolic KOH at 70 °C, cooled and mixed with concentrated HCl and H2O.Methylmercury was converted to ethylmethylmercury by treating the solution with 2 M2. simple direct technique for determination of total Hg in blood, urine and fish tissue by ICP-MS.151 The method included a novel disinfection procedure for urine and blood by the addition of a virucidal agent, Virkon, to each sample.Since Virkon precipitated blood proteins, subsequent dissolution with TMAH was necessary for these samples. To each solution was then added a sequence of diluents, with mixing between each one. Matrix matched calibration standards were prepared 3 HNO3 were added. After 24 h, appropriate diluents were added to the clear solutions, neutralized with aqueous NH3 and diluted with H2O for measurement by ICP-MS.Wash solutions were optimized and wash-out times were <130 s for Hg concentrations of30 mg l-1. The wash solution for blood and urine was dilute NH -NH4H2PO4 containing EDTA and Triton X-100. The best wash for the fish tissue digests was an aqueous solution of 0.1% (v/v) Triton X-100. Extensive IQC data were reported, and the LODs were 0.13 mg l-1 for Hg in blood, 0.27 mg l-1 for urine, and 0.004 mg g-1 for Hg in fish. The method did not discriminate between inorganic and organic Hg.Two groups used microwave-assisted digestion and GC-AES to determine methylmercury and HgII species in fish. Pereiro et al.352 described a simple and rapid procedure for simultaneous determination of methylmercury and HgII in fish SRMs. Samples were subjected to a rapid (2.5 min) microwaveassisted solubilization in TMAH, followed by simultaneous quantitative ethylation-extraction of the Hg species into hexane and flash isothermal separation using a multi-capillary regular column (100 cm) or minicolumn (22 cm).Using the minicolumn avoided the need for a chromatographic oven, which was replaced by a small thermally insulated compartment, maintained at a constant temperature, and coupled directly to the MIP-AES detector. No dilution of the GC sensitivity. Detection limits for dry mass were 20 ng g-1 (Hg), eluent with make-up gas was necessary to achieve optimum and 80 ng g-1 (methylmercury and HgII).Gerbersmann et al.153 used a similar approach using GC-MIP-AES with focused microwave-assisted sample digestion, but compared two diVerent derivatization/injection procedures. In the first method ethylation was carried out with sodium tetraethylborate, with extraction into hexane and injection via a cooled system. The second method involved hydride generation with NaBH4 and purge-and-trap injection, which was reported to be a new and little investigated technique for the speciation analysis of Hg.It was found that both methods were suitable for measuring Hg in fish samples, and further work was proposed to develop a combined microwave-assisted digestion/ purge-and-trap instrument which could be used for the simple determination of volatile species in solid samples. 2.6.4 Selenium. Most publications in this review year concentrated on techniques for Se speciation. Two papers, however, investigated methods for measuring total Se.Deaker and Maher28 described a digestion procedure for determination of 745 J. Anal. At. Spectrom., 1999, 14, 717-7812 was added 1 ml CuSO4 (15 g l-1 Cu), 40 mg Te and 15 ml SnCl -hydroxylamine hydrochloride (reducing agent). When a precipitate formed, it was filtered oV and the filter and solid were air dried for 1 h, placed on the instrument support and covered with a PTFE disc for XRF measurement of the Se Ka line (2h=31.87°).Background correction was by measuring 2h=31°. The LOD was 0.2 mg Se, withean recovery of 96%, and results were comparable with those obtained by AAS. Two conference presentations by Crews discussed the use total Se in small samples of fish tissue. Freeze-dried samples (<0.1 g) and HNO3 (1 ml ) were placed in 7 ml screw-top Teflon vessels which were then sealed into larger pressure vessels and microwave heated at 600W for 2 min, 0 W for 2 min and 450 W for 45 min.Digests were diluted and measured with a matrix modifier by ETAAS. Complete recovery of total Se from six SRMs was reported, and the procedure resulted in complete recovery of five Se species which were added to marine tissues (selenite, selenate, selenomethionine, selenocystine, selenocystamine). Added trimethylselenonium was not fully recovered (90-101%). Benefits of this method included increased sample throughput, reduced loss of volatile material, and low dilutions. A Chinese group measured total In a very detailed paper, Emteborg et al.359 presented a Se in pork spare ribs and vegetables by XRF.353 Sample (5 g) speciation method based on microbore ion-exchange chromawas digested overnight with 10 ml HNO3-H2SO4, then heated tography coupled to ICP-AES via DIN or coupled to ETAAS.for 4 h at 60 °C. The cooled digest was diluted to 50 ml with Selenomethionine, selenite, selenate, selenocystine and trime- H2O, boiled for 1 h and filtered if necessary.To the filtrate thylselenonium were separated using two diVerent metal-free microbore anion exchange columns. The chromatographic eluate was nebulized into the plasma at a flow rate of 80 ml min-1, and selenomethionine, selenite, selenate and selenocystine were separated within 15 min. Selenocystine was completely retained on the column and was eluted with a plug of dilute HNO3. It was reported that on-line enrichment of selenocystine was quantitative.Selenomethionine and trimethylselenonium co-eluted on the solvent front, and a second mobile phase. Detection limits were between 20 and 38 ng ml-1 column was used to resolve these species without changing the for the five Se species. Four diVerent extraction methods and clean-up procedures were investigated for preparing the sample matrix (CRM 402 white clover grown on Se-enriched soil ), and all stages of the work were checked by ETAAS analysis.of stable isotopes in speciation and bioavailability studies. The measurement of Se isotope ratios in enriched cod was described with a comparison between results from ICP-MS and GC-MS.354 Codfish had been intrinsically labelled with 74Se from two slightly diVerent sources in terms of isotopic abundance. This complicated the mathematical calculation of 80Se following ICP-MS measurements since this isotope cannot be determined because of the isobaric overlap from 40Ar40Ar.Following derivatization using phenylenediamine, 80Se was measured by GC-MS and found to have a fractional abundance of 0.4408, compared to the value calculated from ICP-MS data of 0.4417. Total Se in the sample was 135.6 mg kg-1, with recovery of approximately 100% by ICP-MS, compared with 62-64% from the GC-MS method. The second conference report355 discussed methods for intrinsically labelling foods such as fish, wheat, yeast and garlic, and Se speciation studies on these foods using enzyme extracts and chromatography coupled to ICP-MS.The measurement of blood plasma and urine by HG-ICP-MS was described. Human volunteers were fed Se as supplements to their diet and exchangeable body pool sizes were investigated. It was reported that the observed kinetic diVerences in behaviour of ingested forms of Se indicated that the forms were metabolized diVerently. It is hoped that this work will be published in detail.Speciation of Se compounds by HPLC coupled to ES-MS or ICP-MS was discussed in three conference reports. Larsen356 acknowledged the eYciency, sensitivity and selectivity of coupling HPLC to ICP-MS for Se speciation, but pointed out that identification of separated species depends on relating HPLC retention times with those of available standard substances, and unknown organometallic molecules could not be identified. It was proposed that ES-MS could be used for the detection of molecular ions after their separation by HPLC, and that the combination of ES-MS and ICP-MS holds great potential for speciation analysis.Momplaisir et al.357 described a method based on the separation of organoselenium compounds by HPLC with on-line detection by ES-MS. The organoselenium compounds (including selenocysteine, methyl selenocysteine, allyl selenocysteine, propyl selenocysteine, selenomethionine, selenoethionine, selenocystamine, selenoniumcholine and trimethylselenonium ion) were separated on a C18 or cyanopropyl whilst almost all the laboratory-extracted oils had very low bonded phase column, and under optimum conditions could be detected in the sub-nanogram range.The method was 746 J. Anal. At. Spectrom., 1999, 14, 717-781 applied to a Se-enriched food supplement and a urine SRM spiked with three organoselenium compounds. Plants and nutritional supplements enriched with Se were investigated by HPLC-ICP-MS.358 An ion pair chromatographic method with ICP-MS detection for the separation of selenoamino acid standards potentially present in real samples was presented. Ten selenoamino acid standards could be separated, including cis-trans isomers of Se-1-propenyl-diselenocysteine and selenoxides.Qualitative and quantitative results from the analysis of extracts of Se-enriched yeast-based nutritional supplements and Se-enriched allium vegetables were presented and discussed.2.7 Single and multi-element analysis of food 2 Trace elements were measured in edible oils and fats by four groups. A group at the US Food and Drug Administration reported a method for measuring Cu, Ni and Pb in edible oils by ICP-AES and ETAAS following atmospheric pressure microwave digestion.360 Method detection limits for all elements were equal to or less than 50 ng g-1 with ICP-AES and 30 ng g-1 with ETAAS.Spike and recovery experiments 100 ng g-1 level in soybean oil for Cu, Ni and Pb were between were carried out with corn and soybean oil. Recoveries at the 90 and 106% by ICP-AES, and between 89 and 106% by ETAAS. For corn oil they were in the range 93-103% for ICP-AES and 90-117% for ETAAS. Day-to-day reproducibility was demonstrated by repeat analyses of two spiked canola oils. A method was developed by van Dalen to measure P and S in edible oils and fats by WDXRF.361 The samples were measured in disposable liquid cells after solidification with 15% stearic acid to obtain a stable measurement, and results by WDXRF were compared with data obtained by ETAAS for P, and with an O combustion method for S.The LOD was 2 mg kg-1 for both P and S and the long-term precisions were 3% and 5%, respectively. It was reported that the method was also suitable for the analysis of lecithins. De Leonardis et al.362 measured Cu and Fe in 47 samples of virgin olive oil by AAS in order to evaluate their eVect on oxidative processes.Oil samples were obtained from local mills or extracted in the laboratory from various oil cultivars, and one part of each sample was analysed immediately whilst the other was stored in a sealed glass container in a cool, dark room for one year. Levels of Fe in the mill-produced oils were higher than those produced in the laboratory, although there was less diVerence in Cu levels between the two groups.After one year's storage, the mill-produced oils were highly oxidized, levels of peroxides. Giaccio et al.363 used AAS to investigate a range of elements which may act as catalysts to olive oiloxidation. The content of Co, Cr, Cu, Fe, Mn, Ni and Zn was measured in five varieties of olives harvested at various stages of ripening. The metal levels were found to be variable and there was no clear correlation to literature values for metals in virgin olive oil. 3, Multielement analysis of fruit and vegetables was reported by four groups. Thi Huynh et al.364 measured REEs in rice by both ICP-MS and INAA.Samples for analysis by ICP-MS 2.7.1 Wine and alcoholic beverages. Interest continued in were digested by microwave heating successively with HNO the elemental analysis of wine and alcoholic beverages. H2O2 and HF, and the residue was taken up in H2O. Internal Cabrera-Vique373 measured Pt in wine by ETAAS.Samples of standardization was with Be, In and Re. Two reports by Penuela et al.365,366 investigated the mineral content of frozen 3-H2O2 or dry mineralization (details given). and boiled spinach. Concentrations of Ca, Cu, Fe, K, Mg, Mn, Na and Zn were measured by AAS in three fresh samples of spinach. Each sample was then frozen using a laboratory procedure similar to an industrial process and the samples were stored frozen and studied over four consecutive months.Slight changes were noted in the mineral content throughout the storage period, and some metals increased in the last month of storage. It was reported that there was little diVerence between the mineral content of raw and boiled spinach since the trace elements were not leached into the cooking liquid. Bruggeman and Kumpulainen367 carried out a five-year study on mineral elements in various bread grains, flours and baked breads.They measured Ca, Cd, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Se and Zn by AAS, and reported that individual element concentrations in grains showed only minimal year to year variations. The eVects of freezing and long-term storage on the trace element content of papaya were investigated by a Spanish group.368 Fruit samples from female and hermaphrodite flowers were analysed fresh, frozen and stored frozen for periods up to 1 year, and the elements measured by FAAS were Ca, Cu, Fe, K, Mg, Mn, Na and Zn.It was reported that K was the major element in both types of fruit, and the Na content was found to be diVerent from literature values. The freezing and storage process mainly aVected Zn concentrations in both fruit types, K in female fruits and Na, Mg and Mn in hermaphrodite fruits. Few methods for single element analysis were reported during the review year. Sun et al.369 described a method for determining B in plants and plant-derived foods by ultrasonic nebulization-ICP-AES.Samples were ashed at 550 °C for 4 h, the ash dissolved in 5% mannitol-1 M HNO3, boiled gently and filtered when cool. The resulting solution was introduced into the ICP via an ultrasonic nebulizer for determination of B at 249.773 nm. The method was validated with two SRMs, and results agreed with the certified values. The LOD was 0.5 mg l-1 and recoveries ranged from 93-106%. Plessi et al.370 measured Al by ETAAS and Zn by FAAS in powdered infant formulae and infant food following acid digestion with microwave heating.The LOD for Al was 0.44 ng ml-1. Beverages based on tea gave the highest Al levels, whilst soy-based infant formulae had higher concentrations (7 and 7.8 mg g-1) than milk-based formulae (3-3.5 mg g-1). Formulae based on hydrolysed vegetable protein contained Al levels of 13 and 17 mg g-1. Concentrations of Zn were more variable, but only one sample had a level below the recommended minimum of 13 mg g-1.The results were discussed in the paper. Two groups reported their studies on Ti. A German group used ICP-AES to measure the Ti levels in a range of foods and beverages.371 They reported that on average plants had lower levels than animal-based foods, although some plants showed signs of Ti accumulation. However, since the biological function and environmental distribution of Ti were unclear, the authors admitted that the nutritional and health signifi- cance of the data presented was uncertain. The feasibility of using Ti as a food contact material was the subject of an investigation by Feliciani et al.372 Acetic acid and acetic brine were used as aggressive food simulants to study the behaviour of stainless steel and Ti during exposure times and temperatures to mimic both long- and short-term exposure.Migration of Cr, Mo, Ni and Ti was monitored by measuring concentrations in simulants by ETAAS, and Fe was determined by FAAS.It was concluded that Ti could be regarded as a candidate food-grade material. red, white and rose� wines were prepared by either microwave digestion in HNO Analysis of Pt was at 265.9 nm with deuterium arc background correction. Matrix interferences were due to combinations of elements rather than specific ions, and the two sample preparation methods gave similar results. The LOD was 100 pg Pt, and recoveries ranged from 92.5-102% with RSDs of 7.5-10%.The method was recommended for routine analysis and quality controls of wine and similar beverages. Levels of Pt in French wines were found to be generally the same as those reported for Italian wines. The same group described the determination of Cr in French wine and grapes by ETAAS.374 Chromium was measured directly in wine and in acid-digested wine and grape samples, and no diVerence was reported between the direct and mineralization procedures.The detection limit was 1.8 pg of Cr with mean recovery of 99.3%. The Cr content of 79 wines and 12 varieties of grape was reported and the contribution to dietary intake was discussed. McKinnon and Scollary375 investigated the suitability of ultrafiltration for examining the distribution of metals in diVerent particle size fractions of wine. Bottled wine samples were shaken, filtered through a 0.45 mm cellulose acetate membrane filter and ultrafiltered through Amicon disc membranes with molecular weight cut oVs in the range 100 000-1000.Ultrafiltrate portions were analysed for Al by ETAAS, for Cu and Fe by FAAS, for Pb by stripping potentiometry, and K and Na by flame photometry. Results were interpreted in terms of interactions with potential binding agent. Schwedt et al.376 compared the results of seven diVerent methods for measuring Cu in wine.Detailed analytical procedures were described for Cu trace analysis by FAAS, ETAAS, ICP-AES, a catalytic procedure with 3-hydroxybenzaldehydrazine, urease inhibition with ammonium determination, direct potentiometry with Cu selective electrodes, and inverse diVerential-pulse polarography. The methods were also applied to water and soil leachate samples. Chmilenko and Baklanova377 described a method for de-gassing sparkling wines by ultrasound for AAS determination of metal impurities.Samples of champagne (25 ml ) were agitated at 18 kHz and 1 Wcm-2 for 2 min, then 3 W cm-2 for 2 min, for measurement of Cu (>0.1 ppm), Fe and Zn by FAAS. Treated samples were mixed with Pb(NO3)2-NH4NO3 matrix modifier for determination of Cd, Cu and Pb by ETAAS. An alternative method involved ultrasonic decomposition of 100 ml samples with 20 ml of H2O2. Cations were then extracted with DDC into IBMK for analysis by FAAS or ETAAS.Mercury was determined by CVAAS. The method was reported to be quicker than existing standard methods and gave comparable results. Considerable activity was directed to the measurement of Pb in wine. Kaufmann378 used Pb measurements from 7000 wine samples to identify possible sources of Pb contamination. Using a previously described method which avoids sample preparation, Pb was measured by ETAAS with a Pd modifier. It was reported that atmospheric pollution-related contamination was not responsible for elevated Pb concentrations.The presence or absence of an Sn-Pb capsule (cap covering cork) and its state of corrosion had a very minor influence on Pb levels. A reported positive correlation was confirmed between wine age and Pb concentration, although further 747 J. Anal. At. Spectrom., 1999, 14, 717-781statistical analysis indicated that the most significant contribu- determination of Hg in food, including conditions for GC ting factors were vintage and wine colour.It was concluded measurement of organomercury compounds. that the main contamination source was brass, and brass pipes Metal contaminant levels in peanuts were investigated by and taps were always found in wineries known for elevated two groups. Yankov et al.387 used AES to study the uptake Pb levels. The authors indicated that there has been a continu- and localization of Cd, Cu, Pb and Zn in peanuts produced ing and significant reduction in Pb levels in wine during the in an industrially polluted region of Bulgaria.They reported past seven years. Liu and Jiang379 discussed the eVect of that Cu, Pb andn accumulated selectively in the underground matrix, hydride generation and ion interference during determi- parts of the plant, whilst Cd was concentrated in the seed in nation of Pb in wine by HG-AFS. High sensitivity and selectivity were reported, with a detection limit of 0.2 ng ml-1.concentrations exceeding the legal limits, and concluded that heavy metals enter the peanut plants either through the root Chinese white wine was directly sampled for measurement of system or as an aerosol through leaves and stems. Cadmium Pb by ETAAS.380 Ashing was carried out at 600 °C for 10 s, levels in Australian peanut products were investigated by and atomization at 2000 °C for 4 s, with background correction Tinggi.388 Samples of peanut butter, raw, roasted and crushed using a deuterium lamp.The matrix was eliminated by washing peanuts from various commercial producers and local markets the sampler nozzle with C2H5OH. Using the method of were pre-digested in a microwave system prior to dry ashing standard additions, recovery of Pb was 90-108%, with RSD of 1-3.7%, and the detection limit was 31 pg. 2O and a reagent plug of the disinfection of drinking water. However, a disinfection Two publications described the elemental determination in beer by AAS.Fernandes et al.381 developed a method for measuring high levels of Ca, K, Mg and Na by FES and AAS. Two manifolds were designed to carry out substantial dilutions required to bring samples within linear concentration ranges. Samples were diluted on-line with H LaIII solution (1% 0.6 M HCl, 0.12 ml ). The methods were reported to give good agreement with results obtained by manual dilution, with a sample throughput of 120-200 samples h-1, and a significant reduction in consumption of expensive LaIII reagent.Fernandes and Rangel382 described an FI system for determination of Cu in beer by AAS using the method of standard additions. A manifold, based on the 'merging zone technique', was used to prevent the burner from clogging. Results obtained using five standard additions were comparable with those from a reference method, the LOD was 5 mg l-1, and the sampling rate was about 30 samples h-1.2H5OH. A bromide ions were separated and identified in an aqueous The sampling rate was increased to 75 h-1 by using only two standard additions, but results were less precise and accurate. An FI manifold was coupled with ICP-MS for the measurement of 27Al, 75As, 138Ba, 114Cd, 53Cr, 63Cu, 55Mn, 208Pb, 88Sr, 238U and 64Zn in vodka and brandy.383 Small volumes of C2H5OH-H2O solutions (10-40%) were injected into the plasma via the FI manifold.It was observed that this caused a change in ionization conditions, and the incident power was increased to 1.6 kW. Transient signal behaviour was studied for the 11 elements by increasing the C2H5OH content in the samples, and it was noted that the most aVected elements were As, Pb, U and Zn. There was no correlation between ionization potential and signal change in the presence of C rapid method was described by the US Bureau of Alcohol, Tobacco and Firearms for the determination of Cu in malt beverages without preconcentration.384 Samples containing up to 7% alcohol by volume were diluted five-fold with deionized water and analysed directly by ETAAS, with NH4H2PO4 as the matrix modifier.The LOD was 5 mg l-1 in the malt beverages and analytical results were verified by standard additions and spike recoveries (95-108%, RSD <10%). Copper levels between 22 and 86 mg l-1 were measured in 20 US drinks, with levels of 26-79 mg l-1 determined in 12 imported malt beverages.2.7.2 Metal contamination in food. Increasing awareness of food quality issues and proposed legislation setting limits on levels of toxic elements in food have resulted in a flurry of work to determine metal contaminants in a range of foodstuVs. Two reviews appeared during the review year on methods for the determination of Cd, Hg and Pb in foods. Janin and Schnitzer385 discussed ashing, AES, AAS, ICP-MS and other procedures, with 22 references.Boisset386 presented 29 references and discussed spectrometry and other methods for the 748 J. Anal. At. Spectrom., 1999, 14, 717-781 to 0.031 mg kg-1, were lower than the maximum permitted for Cd analysis by ETAAS. Mean values, ranging from 0.013 0.05 mg kg-1. concentration for Cd in peanuts in Australia, currently set at Two conference presentations and three papers described the determination of bromate in drinking water. Ozonation has been successfully used as an alternative to chlorination for by-product (DBP) of the ozonation of bromide-containing source water is bromate, a potential carcinogen for which the WHO has established guidelines levels in ozonated water.Creed and BrockhoV389 reported that IC-ICP-MS had excellent sensitivity and selectivity as a separation and detection system, whilst allowing the use of ID analysis. The method LOD for direct analysis of bromate was 0.3 mg l-1.Argonbased spectral interferences on mass 81 were discussed and matrix-based interferences which were chromatographically resolved from bromate were tentatively associated with phosphate and sulfate. The chromatographic resolution of bromate from other brominated DBPs was described, and results obtained by ID and direct analysis in water samples were compared. Cooney and Browner390 also used IC-ICP-MS to measure trace levels of bromate in drinking water, but reported that, since the positive mode ionization eYciency of Br was fairly poor, larger than normal chromatographic injections were necessary to obtain a measurable signal when using conventional nebulizers and lower liquid flow rates.The development of an oscillating capillary nebulizer in their laboratory resulted in an increase in transport eYciency when using lower flow rates, thereby eliminating column concentration techniques and large injection volumes.Bromate and solution at a concentration of 10 mg l-1 each using IC-ICP-MS in the positive ion mode, and the LOD was 2 mg l-1. However, further investigation was required to overcome co-elution of bromate with bromoacetates, and to reduce the LOD to submg l-1 levels. Nowak and Seubert described a method in both English391 and German392 for the ultra-trace determination of bromate in drinking waters by microbore column IC coupled on-line with ICP-MS.Water samples (0.885 ml ) were injected onto a column packed with a self-made high capacity, high performance anion exchanger [5 mm poly(styrenedivinylbenzene)-DMEA]. Adsorbed ions were eluted with 4NO3 at pH 6 containing 20 mg l-1 Sr as internal 60 mM NH standard. The eluate was nebulized directly into an ICP-MS instrument for detection of 79Br. A clear separation was achieved between bromate and other bromine species, such as bromide and bromoacetic acid.The LOD was 50-65 ng l-1 in samples with an RSD of 5% at a bromate concentration of 500 ng l-1, and no sample pretreatment such as matrix elimination or trace enrichment was required. Each complete analysis took between 10 and 15 min, depending on the bromide content of the sample. Elwaer et al.393 developed a method for measuring bromate in drinking waters using FI-ICP-MS.They identified a need to improve method sensitivity substantially in view of EC, US EPA and WHO recommendations for a maximum contaminant level of 10 mg l-1 of bromate in drinking water.An FI system with a microcolumn packed with a strong anion exchanger was interfaced to an ICP mass spectrometer to carry out on-line separation of bromate and bromide in drinking water samples. The eluent and carrier was 50 mM malonic acid and good separation of bromate and bromide was reported. The presentation included aspects of method development, including operating parameters and the eVect of other co-existing ions on analyte recovery and discussed a survey of bromate in process and mineral waters. There was continued interest in monitoring the levels of toxic elements in infant foods and breast milk.Lutter et al. carried out a survey of toxic metals and radionuclides in Kazakhstani breast milk.55 The data presented were from a larger study designed to provide a scientific basis for the development of a national infant feeding policy.Sample collection procedures were described in detail; two independent analytical techniques (ICP-MS and NAA) were used to verify the results, and good agreement was found between the two methods. The major elements Fe and Zn were measured by ICP-AES and 137Cs by a Ge detector. Median concentrations of toxic elements were within the range reported for other countries, and 137Cs was not detected in any samples. All the essential trace elements, major minerals and electrolytes were within reference values, and as a result of the study the Ministry of Health for Kazakhstan is promoting breast feeding.Baum and Shannon394 used AAS to measure the concentration of Pb in home-prepared reconstituted infant formula. Forty concentrations above the current action level of 15 mg l-1 infants were evaluated and two of the 40 samples had Pb required by the US Environmental Protection Agency for safe water.These samples contained 17 and 70 mg l-1 and were prepared with cold tap water from houses >20 years old. It was concluded that the use of infant formulae requiring reconstitution may present an inadvertent Pb hazard to young infants. Salvato395 investigated Cd levels in samples of liver, meat, fish, rice and cocoa powder and in infant foods containing these ingredients. Samples were either acid-digested or ashed and Cd was determined by ETAAS with tube and L'vov platform. The highest Cd levels, found in liver, exceeded the limit of 0.09 mg kg-1, whilst Cd was not detected in meat and fish.Concentrations in rice and cocoa powder were in line with the safety limits of 0.1 and 0.3 mg kg-1, respectively, and Cd levels in baby foods were largely within acceptable tolerances. Two papers by Danev et al. investigated residues of environmental contaminants in meat and other foods. Cadmium levels were measured by ETAAS in beef from animals grazed close to lead and zinc smelter plants in Macedonia.396 Samples of muscle, liver and kidney from 14 animals were analysed, and results showed that 29% of muscle samples, 86% of liver samples and 100% of kidney samples were contaminated above the limits set by the national regulations. In a separate paper,397 the same team reported that levels of both Cd and Pb were above the current legal standards in a range of animal tissues (cattle, sheep, goats, wild birds) and foods (sheep cheese, eggs, honey) due to contamination from smelters.A Polish group398 studied the pollution contamination of flour by Al, Cd, Four papers discussed dietary intakes of Cd and Pb. Oral Cu, Mn, Mo and Zn. Zinc was measured by FAAS and the Cd exposure of adults in Germany was discussed by Mu� ller other elements by ETAAS, following mineralization in et al.406 using market basket calculations. Representative foods HNO3+HClO4 (4+1).A wheat flour CRM was used to from 11 categories were purchased in 1988 (864 individual validate precision and accuracy of the data, and the method was applied to samples of potato, rye, corn and two wheat flours. The Pb content of edible wild mushrooms was used as an indicator of environmental contamination in north-west Spain.399 Levels of Pb were measured by ETAAS in 95 samples of 13 species, and the average Pb concentration of the samples was 1 ppm dry weight.Contamination due to traYc pollution was particularly obvious in the species Coprinus comatus, which had the highest Pb concentration (10.43 ppm) in samples collected in a city centre, and it was reported that this species could be considered as an indicator of Pb contamination. Angelova et al.400,401 used AAS to measure Cd, Cu, Pb and Zn in grapes (skins, pulp, seeds and stalks) harvested from two regions with diVering degrees of heavy metal pollution.Most of the heavy metals were concentrated in the stalks, and least in the pulp. Significant diVerences in amounts of the heavy metals were noted for skins and stalks from the two regions, but not the pulp and seeds. Cyhexatin (tricyclohexyltin hydroxide) is a non-systemic acaricide used to control the motile stages of a wide range of phytophagous mites, particularly in fruit. Anderson et al.402 used ICP-MS as an initial screen for total Sn levels to indicate the possible presence of pesticide residues in apples, pears and below 0.06 mg kg-1, equivalent to the study's target reporting kiwi fruit.Background levels of Sn in these fruit were normally limit for cyhexatin of 0.2 mg kg-1. A total of 72 samples were screened, of which three apple samples contained Sn at >0.06 mg kg-1, and were re-analysed by GC-MS as a con- firmatory method for cyhexatin. It was reported that the ICP-MS preliminary screen reduced the number of samples requiring analysis by GC-MS, with a cost saving in staV hours of approximately 30%.This screening method could potentially be applied to other organometallic pesticide residues. 2.8 Dietary intake studies There has been much interest during the past year in studying dietary intakes of minerals and particularly the toxic elements. Tripathi et al.403 investigated As intake by the adult population of Bombay City, using HGAAS to measure As in air, duplicate diets and body fluids.The LOD was 0.02 ppb and SRMs were used to assess data reliability. It was reported that dietary intake was the major contributor to total As intake, and that a mean blood As concentration of 1 mg dl-1. The daily intake the turnover time in blood was approximately 33 d, based on of As by the adult population of Bombay was much lower than the WHO recommended value of 140 mg. Daily dietary Rb intake in Belgium was evaluated by duplicate portion sampling.404 Samples were digested in a microwave oven and Rb was measured by AAS.It was reported that the mean daily intake (2.2±0.3 mg) was similar to levels in most other countries. However, it is unclear whether Rb is an essential element for humans, so the intake level could not be assessed with respect to a recommended range for safe and adequate dietary intake. Llobet et al.405 used ICP-MS to estimate dietary intake as part of a survey of environmental pollution and human exposure to metals in Tarragona, Spain.Food items from 11 food groups were analysed for As, Be, Cd, Cr, Hg, Mn, Ni, Pb, Sn, Tl and V, and it was found that Be, Tl and V were below the detection limit for all food groups. Dietary intakes of the remaining metals were established by a total diet study, and results agreed well with literature values from recent surveys in diVerent countries. It was reported that dietary intakes of As, Cd, Hg and Pb should not present a health hazard for the population of the Tarragona area.samples of 94 foods) and 1991 (642 samples of 105 foods), and prepared for cooking but left raw. Samples were dried, dry-ashed at 450 °C and the ash taken up in 2% HCl. Cadmium was measured by ETAAS using a boric acid modifier method (referenced ), which gave an LOD of 0.08 mg l-1 and a mean Cd concentration of 33.3 mg kg-1 dry weight. The average 749 J.Anal. At. Spectrom., 1999, 14, 717-7813 daily intake of Cd was reported to be 10-14 mg, which represents 16-19% of the provisional tolerable weekly intake (PTWI), and there was no diVerence between Cd intake in 1988 and 1991. There was no toxicological risk from orally ingested Cd. Kim et al.407 investigated the Cd exposure level from traditional food in the North-West Territories of Canada. A risk assessment was based on 24 h dietary recalls, traditional food use frequency and Cd levels measured in acid digests of about 30 species of wildlife and plants by FAAS and ETAAS.The range of Cd concentrations was between 0 and 1869 mg per 100 g, with lowest levels in fruits and the highest in caribou and moose oVal. Average Cd intakes were estimated to be no greater than 9% of the WHO PTWI (400-500 mg), although further clarification was necessary regarding health implications for frequent consumers of caribou and moose.Tahvonen408 investigated dietary intakes of Cd and Pb from beverages in Finland. The Cd and Pb contents of carbonated beverages, juices, beers and wines were quantified by ETAAS using Zeeman background correction, peak height mode and the method of standard additions. Wines we diluted with 10% HNO and other beverages were digested in concentrated 3. The highest level of Cd (2 mg l-1) was found in a HNO Pb concentration was 34 mg l-1 in imported red wines.It was domestic red wine made from raspberry, and the highest mean concluded that beverages contributed a negligible amount of Cd and Pb to the average Finnish diet, although beverages accounted for about a fifth of the total Pb intake. Mustafa et al.409 measured 11 elements by AAS in 20 diVerent species of vegetables commonly consumed in Bangladesh. They reported that concentrations of Cd and Pb were below the tolerable limit recommended by FAO/WHO and did not pose any health risk for consumers.Results of the other elements were also discussed. Dietary intakes of essential elements and micronutrients have also been considered. The eVect of energy restriction on the mineral content of diabetic diets was investigated by a Japanese group.410 Diabetic diets (1200 kcal and 1840 kcal ) oVered in a hospital were analysed by AAS to quantify Ca, Cu, Fe, K, Mg, Mn, Na and Zn. It was reported that the Fe level in 1840 kcal diets was 6.60±1.44 mg d-1, which is much lower than the recommended value.The Cu, Mg and Zn levels were also low. All elements measured were even lower in the 1200 kcal diet, and it was reported that these results were considered to be characteristic features of low-energy diets. Biego et al.411 measured the mineral contents of diVerent kinds of milk and estimated dietary intake in infants from birth to three months. Levels of Al, Ba, Cd, Cr, Cu, Mg, Mo, Ni, Pb, Sn and Zn were measured by ICP-MS following microwave digestion in acid of six milks (cow's milk-based formula, breast milk, soya milk, bottled milk, dried milk and evaporated milk). Soya milk contained the highest levels of Al, Ba, Cu, Mg, Mo and Ni, and except for Ni in soya milk, the dietary intakes of minerals were below or close to those recommended by the FAO/WHO.Daily dietary Fe intake in Belgium was evaluated by Van Cauwenbergh et al.412 using duplicate portion sampling. Samples were heated in a microwave oven and Fe was measured by AAS.The adult Fe intake (11.3 mg d-1) was above the recommended daily allowance of 10 mg d-1 for adult males, but below the value of 15 mg d-1 for adult women. Two papers reported dietary intake of Mo, an essential micronutrient for which the physiological requirement in adults is approximately 25 mg d-1. Holzinger et al.413 investigated the Mo intake of adults in Germany and Mexico by means of duplicate portion analysis using ICP-AES.Results showed that the Mo intake had increased from 1988 to 1996, and diVered for German adults depending on location and the kind of diet, with vegetarian women consuming 179 mg d-1, compared with 89 mg d-1 by women on mixed diets. There was a significant diVerence in Mo consumption between 750 J. Anal. At. Spectrom., 1999, 14, 717-781 German and Mexican adults, with Mexican women consuming on average 162 mg d-1, whilst Mexican men consumed 208 mg d-1 compared with 100 mg d-1 for German men.It intake, with no risk of exceeding the toxic dose of 150 mg kg-1 was concluded that Mo requirements were met by normal body weight. Daily dietary Mo intake in Belgium was studied by Van Cauwenbergh et al.414 Duplicate portion samples of meals, drinks and between meal snacks were collected during seven consecutive 24 h periods from four locations. The meals were cut up, inedible portions discarded and the remainder homogenized. Portions were freeze-dried and acid digested in a microwave oven prior to analysis by AAS with a Pd-Mg(NO3)2 matrix modifier.The dry weight LOD was 0.3 ppb and accurate results were obtained for two CRMs. The results were compared with other published data. 2.9 Characterization studies Characterization of wines according to their trace element composition was investigated by four groups. Baxter et al.415 reported a method for determining the authenticity of wines from England and Spain.Wine samples were diluted 1+1 with dilute HNO3 containing In as internal standard. Portions were injected into a carrier stream of 0.5% HNO3 containing In and 5% C2H5OH for ICP-MS analysis. Detection limits were 10-100 ppt, recoveries were 100±25%, and accuracy was tested by measuring CRMs. The data set (48 trace element concentrations in 112 wines) was subjected to discriminant analysis.Spanish wines were classified into their regions of origin, and English and Spanish white wines were diVerentiated from each other by their trace element profiles. When red and rose� wines were included in the Spanish set, English and Spanish wines were diVerentiated with 95% accuracy. Greenough et al.416 investigated the relationship between wine composition, vineyard and wine colour by elemental fingerprinting using ICP-MS. Thirty-three elements were measured in 17 white and 10 red wines from Canadian wineries.It was reported that wines from grapes from the same vineyard tend to be most similar, regardless of vintage, grape variety or processing winery, implying that the element fingerprints were derived soil signatures. Discriminant analysis indicated that combinations of approximately six elements from several geochemical groups could accurately classify the wines according to vineyard.Twenty-six elements (Al, As, B, Ba, Ca, Ce, Co, Cr, Cu, Fe, Ga, La, Mg, Mn, Mo, Ni, P, Pb, S, Sb, Sn, Sr, Ti, U, V, and Zn) correlated strongly with vineyard of origin, although the limited number of wines available for this study required that further work be done to confirm these conclusions. A Brazilian group attempted to characterize wines from Argentina, Brazil and Uruguay according to their mineral composition.417 A total of 31 wines were analysed by AAS, FES and colorimetry, and the results were interpreted by PCA.It was reported that the elements which demonstrated the highest discriminant eVect were Fe, K, Li, Mg, Mn, Na, P and Rb, and it possible to identify wines from each country. Sun et al.418 used ICP-AES to measure Al, B, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Rb, Sr, V, and Zn in samples of 17 wines from six regions. Results were analysed by a three-layer artificial neural network (ANN) model with background propagation of error, and compared with those obtained by cluster analysis, PCA, the Bayes discrimination method and the Fischer discrimination method.An ANN method gave 100% accurate classification of wine samples on a regional basis, and was considered to be more accurate than the other procedures. Multivariate characterization of wine vinegars from southern Spain was described by Guerrero et al.419 Forty wine vinegars were analysed for mineral content using FAAS for Ca, Cu, Fe, Mg, Mn and Zn, FES for K and Na, and HGAAS for As.Several pattern recognition techniques wereapplied to the data, and the best discriminant elements were Fe, Mg, Mn and Na. The samples were successfully divided into two groups (slow and quick vinegars) according to the rate of their fermentation. 25H2 ratios at the methyl and methylene sites of OYcial Methods to include soy-based, whey-based and enteral formulae. Four groups studied the characterization of other beverages according to their trace element content.Martý�n et al.420 measured 11 metals (Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr and Zn) by ICP-AES (conditions given) to study 41 samples of arabica and robusta green coVee varieties. Cluster analysis and PCA were applied to the results, and it was reported that significant diVerences were found in the metallic content of the two varieties. The largest diVerences were found in levels of Cu, Mn and P and these were used to characterize the coVee varieties, with Cu and P higher in robusta, and Mn higher in arabica coVee.A preliminary study to classify tea by geographical origin was undertaken by Marcos et al.421 Fifteen types of tea from ten diVerent countries were digested in HNO3, and the trace element content measured by ICP-AES (Al, Ba, Ca, Cu, Fe, Li, Mg, Mn, Sr, Ti and Zn) and ICP-MS (Cd, Co, Cr, Cs, Hg, La, Li, Nd, Ni, Pb, Pr, Rb, Se, Sn, Ti, V and Zr).The data obtained were analysed by UNSCRAMBLE, a chemometrics package incorporatPCA, and the results indicated that a distinction could be made between African and Asian and between Chinese and Asian teas. The authenticity of Brazilian orange juice was determined by isotopic analysis.422 Samples of authentic orange juice were analysed by site-specific natural isotopic fractionation nuclear magnetic resonance (SNIF-NMR) to determine D C2H5OH produced by fermentation of the orange juice.Stable isotope ratio mass spectrometry (SIRMS) was used to determine the ratio of 13C512C in the C2H5OH and the ratio of 18O516O in the citrus juice water. The mean ratios for the authentic samples were used to determine whether sugar had been added or retail samples had been diluted with tap water. 2.10 Reference materials and collaborative trials An interlaboratory study of an ETAAS method for the determination of Pb in wine was conducted by Brereton et al.423 Seventeen laboratories from France, the United States and the United Kingdom took part in the study, using a variety of ETAAS instruments.The method incorporated a novel matrixmatching procedure to minimize matrix eVects between Table 1 Analysis of clinical and biological materials, foods and beverages Matrix Element Tissues Ag Ag Ag Biological materials Blood, serum, urine Wheat Al Serum Al Serum Al Technique; atomization; analyte form* AA;F;L AA;F;L AA;ETA;L -;-;- AA;ETA;L AA;ETA;L Sample treatment/comments Very high concentrations were found in specimens from an unusual case of fatal Ag poisoning.Samples were digested with HNO and H2SO4 Ag was extracted from sample solutions with 3,6-dithiaoctane (8-2S). A single drop nebulization technique was employed for atomization Samples were heated with H2SO4, diluted with H2O and then KI-20% ascorbic acid was added.This mixture was extracted with IBMK and the organic layer used for measurement of Ag (in Chinese) 26Al was used to study cellular transport of Al. The authors concluded that diVerent transport mechanisms were present in those wheat varieties that exhibited Al toxicity compared with those that did not Distribution of Al in serum of occupationally exposed subjects was investigated by three techniques: SEC using a Sephadex G-100 SF column; HPLC with an SEC TSK G 4000 SW column; ultrafiltration with a 10 000 cut oV Centricon membrane 0.5 ml serum, 0.5 ml HNO and 0.2 ml HClO were sealed in PTFE vials and subjected to microwave heating.After evaporation, the residue was dissolved in 0.1 M HCl, and the analyte preconcentrated by addition to an ion exchange column. The eluted Al was transferred to the graphite furnace 2 samples and standards. Good agreement was reported between (24-279 mg l-1) obtained by ICP-MS, and the method was results obtained from participants and target values recommended for use for oYcial purposes.Venkatesh424 described a collaborative study intended to extend the variety of reference materials certified for I. Three diVerent mineralization methods were developed to measure total I by ICP-MS in biological and nutritional materials. A mixture of water soluble tertiary amines was used as the matrix solution for two O combustion methods and a simple extraction at room temperature.Results for the two combustion methods agreed well for concentrations >0.1 mg kg-1. The amine extraction method gave the most precise and accurate results for the mixed diet, milk powder and infant formula samples, but recoveries were low for most of the biological materials owing to incomplete extraction and solubilization of I. The ICP-MS data were compared with NAA results. A collaborative study organised by the US Food and Drink Administration was reported by Cook425 to test modifications to AOAC OYcial Methods.Eight laboratories participated in a study of OYcial Method 985.35 for the analysis of Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn by AAS in ready-to-feed milk-based infant formula and pet foods, and seven laboratories tested OYcial Method 986.24 for the measurement of P in milk-based infant formula by a spectrophotometric method. The samples analysed included soy-based and whey-based infant formulae and a casein-based enteral formula.On the basis of the results, which were tabulated in detail, it was decided to extend the Shrimp and plaice reference materials produced by the Danish National Food Agency were characterized for trace elements and two As species.235 The materials were prepared by dissection, drying, milling and sieving to collect particles less than 150 mm in size. Total trace element concentrations were determined by ETAAS, CVAAS, ICP-MS and ID-ICP-MS.Arsenobetaine (AB) and tetramethylarsonium (TETRA) ion were determined by cation exchange HPLC coupled with ICP-MS or with ion spray MS-MS for verifi- cation. Following rigorous statistical analysis of the analytical data, it was decided to assign certified values for As, Cd and Hg in the shrimp, and As, Hg and Se in the plaice. Indicative values were given for Cr, Pb and Se in the shrimp material, and AB and TETRA ion in both RMs.Ref. 273 3 426 272 427 164 428 4 3 751 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Serum Al Serum Al Serum Al Al Serum, amniotic fluid, tissues Serum transferrin Al Canned soft drinks Al Fruit juice Al Lymphocytes Al Tea, coVee Al Al Wild mushrooms, cultivated mushrooms Fruit juice, milk Al Al Infant formula, infant food Seafood, meat Al Serum Al Al Blood, plasma, tissues Serum Al Blood, tissues Al Al Blood, urine, tissues Urine Al Urine Al Blood, urine Al Tissues Al Brain Al Hair Al Hair Al Al Dialysis concentrates Tea Al 752 J.Anal. At. Spectrom., 1999, 14, 717-781 AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA; HPLC AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;F;L AA;F;L AA; ETA;L AE;ICP;L MS;ICP;L MS;-;S MS;ICP;LC MS;-;S MS;-;S AA;ETA;L AE;ICP;L MS;-;S MS;-;S SIMS; -;S AA;F, N2O-C2H2; L AE;F, 2O-C2H2;L N AA;ETA;L AE;ICP;SEC 8 Serum proteins were precipitated by the combined eVects of 1% TCA and microwave radiation.The deproteinized, low acidity solution was analysed with a simple fast heating programme. There were no matrix 162 0.5 ml serum and 0.5 ml 0.5% Triton X-100 was mixed with 1 ml 0.1 mg ml-1 interferences K2Cr2O7. The sample was atomized from tube previously treated with 50 ml 216 10% ammonium molybdate (in Chinese) Al, as aluminoxamine, was separated from other species in the serum ultrafiltrate by HPLC The results revealed transplacental passage of Al after cutaneous administration 429 to pregnant mice Binding of Al to transferrin in the presence of diVerent amounts of Fe was studied 430 431 432 The eVect of can lining defects on Al concentrations in carbonated drinks was investigated using ETAAS with a L'vov platform and Mg(NO3)2 as modifier.Levels were some 20-fold higher in the defective cans Various acids were discussed with respect to the analysis of trace (nanogram) levels in juices and fruit syrups. A closed PTFE bomb in conjunction with 166 433 HNO3-H2O2 was proposed (in Polish) Al was measured in B and T-lymphocytes from subjects on haemodialysis to investigate the immunosuppression which features in Al toxicity Sample was dried at 105 °C, ashed at 450 °C and then dissolved in HCl prior to 3)2 as chemical modifier.The LOD 434 measurement using ETAAS with Mg(NO was 26 pg A large number of mushroom species were assayed for their Al content. The authors concluded mushrooms do not contribute to human Al intake 298 370 Al and Pb were simultaneously preconcentrated on activated C after complexing with cupferron Samples were microwave digested with 3 ml of 70% HNO3 as the digestion acid. With closed vessels and a 3-step programme digestion was achieved in 9 min. Al was determined by ETAAS, Zn by FAAS.The highest Al levels were found 291 in products based on hydrolysed vegetable protein Lyophilized sample was digested in closed vessels with HNO3-HF, then in open 2O2. Excess HF was removed using H3BO3. Matrix eVects and 71 vessels with H spectral interferences were assessed. HF was shown to be essential for complete recovery of Al Samples were diluted with H2O for Q-ICP-MS and double-focusing sector field ICP-MS.Interferences were removed by using Be and Sc as internal 89 standards Al from a digestion solution was precipitated with 8-hydroxyquinoline. This complex was heated to 800 °C to form Al2O3. Al in urine was precipitated with Na3PO4, complexed with acetyl acetone and Al2O3 similarly formed. The Al 163 2O3, mixed with Ag powder, was taken for AMS Proteins were separated by Fast Protein LC on a MonoQ (HR5/5) anion exchange column and the Al measured in the eluent by Q-ICP-MS and double-focusing ICP-MS.In unspiked samples, Al was bound only to transferrin Al metabolism was studied in rats. 26Al administered by oral gavage was 85 86 determined by AMS Al adjuvents, included in vaccines, were labelled with 26Al and the absorption was measured. Al was measured by AMS Rabbits loaded with Al were used to assess the eYcacy of oral chelating agents. 4359 Possible alternatives to i.v. desferrioxamine were identified It was shown that trace elements may be lost from specimens by precipitation.Methods to ensure re-dissolution were given. Standard additions calibration was necessary to achieve accurate results 26Al was measured by AMS in specimens from volunteers who had received 84 88 experimental doses in biokinetic investigations 26Al was measured by AMS in specimens from mice to investigate tissue distribution and uptake mechanisms 26Al was measured by AMS in specimens from rats to investigate uptake and 87 accumulation in the brain as a mechanism of Alzheimer's disease The hair was ashed and discs formed for irradiation 436 437 Washed hair was digested with HNO and H2O2 and diluted with H2O.The flame conditions were optimized; the 3 LODs were 0.25 and 0.07 mg ml-1 for AAS and AES, respectively (in Chinese) 438 Al was separated from the high salt content of the samples by 5-fold repetitive passage through a 50 mm3 column of 100-200 mesh H+ form of Chelex-100.The Al was then eluted for measurement and the LOD was 0.2 mg l-1 Al species in tea infusions were separated on a Sephadex 12HR10/30 column 440 with spectrometric detection. Al in the infusion was determined by ICP-AES. The same species were found in teas of diVerent originsTable 1 (Continued) As As Biological specimens Human milk, cow's milk Urine As Calcium carbonate As Urine As Urine As Urine As Urine As Urine As Urine As Urine As Waters As Urine As As Grain, cereal products Wine, urine As Drinking water As Drinking water As Mushrooms As As Biological and Food CRMs Foods As Beer, wine As Potable water As Water, urine As Seaweed As -;-;- AA;-;L AA;Hy;FI AA;Hy;L AA;Hy;L AA;Hy;L AA;ETA;L AA;Hy;L A test was devised to evaluate body load of As by administering the chelating agent 2,3-dimercaptopropane-1-sulfonic acid and measuring AsIII, MMA and DMA in urine collected for 2 h AA;Hy;L As species were separated by ion-exchange chromatography.Specimens from subjects living in areas with naturally high drinking water As concentrations were examined AA;Hy;HPLC Specimens were collected from subjects with skin cancer and who lived in an area with high concentrations of As in drinking water. AsIII, AsV, MMA and DMA were determined AsIII, MMA and DMA were separated on a 10% polyphenyl ether GC column which was part of a system which included a series of low temperature traps to collect H2O vapour released from the reaction vessel.Atomization occurred in a heated quartz tube. Samples were from subjects with occupational exposure and from rats administered As compounds AA;Hy;HPLC An FI system was elaborated which included HPLC separation of As species, UV photooxidation with 4% K2S2O3 in 1 M NaOH in a knotted reactor and continuous HG AA;Hy;FIA An FI manifold which included UV photo-oxidation to breakdown organoarsenic compounds, including arsenobetaine, was used. The LOD was 0.1 mg l-1 Inorganic As species were determined by complexation between AsIII and diethyl dithiophosphate, preconcentration onto a C autosampler cup and quantitation by ETAAS with a Pd modifier.Total As was determined directly by ETAAS and AsV obtained by diVerence AA;ETA;L AE;ICP;L AF;Hy;HPLC AA;Hy;L AA;Hy;L AF; Hy;HPLC AF;Hy;HPLC AA;Hy;L AA;Hy;HPLC On-line HPLC-microwave digestion-HGAAS was proposed for speciating As without the need to invest in more expensive instruments The eVect of various food treatments-boiling, microwaving, irradiation, etc.,- on As compounds was investigated.In some cases degradation was observed, but no health risks were thought to be present AF;Hy;L AF; Hy;L Hy;-; HPLC MS;-;- A review of methods for analysis and speciation 441 442 Total As was determined in the breast milk of 35 lactating women and were 4.219±0.079 and 4.932±0.38 mg l-1 in breast and cow's milk, respectively milk from 36 cows.All samples originated in Izmir, Turkey. The levels 24 443 As species were separated using Dowex 50W-8X-AG1 X8 ion-exchange column. The eluted species were reduced downstream by 15% KI-5% ascorbic acid and then by 1% NaBH4. AsIII, AsV, MMA and DMA were measured. A second stream of the FI manifold carried unseparated sample through a microwave oven for digestion, reduction and measurement of total As Arsenic in CaCO3 used in food products was analysed by dissolving the sample in a minimum volume of H2O then digesting with concentrated HCl.At 193.7 nm the LOD was 0.6 ng ml-1 (in Chinese) 173 Samples were diluted 1+9 and incubated for 1 h with 1% cysteine in 0.03 M HCl. A commercial FI system was then used to measure AsIII, AsV, MMA rates, 4 etc., were optimized and the LOD was 1 mg l-1 and DMA.Conditions of NaBH concentration, acid concentrations, flow 444 180 181 175 25 26 335 18 172 445 3minicolumn, elution into an HCl, KI and sodium hypophosphite were added to urine to form 'iodide arsines' of AsIII, MMA and DMA, which were extracted into toluene and back extracted with 1 mM NaOH. As from dietary sources was not measured Samples were microwave digested using HNO -HCl-HClO4. Hg was also 343 446 336 342 determined (in Chinese) A novel HPLC-HGAFS system was described in which photo-oxidation in the presence of persulfate was used to decompose As species in the column eluent, allowing both reducible and non-reducible species to be determined 3 multivariate calibration functions were employed-classical least squares, inverse least squares and Kalman filtering-but no significant diVerences were observed for recoveries of AsIII, AsV, MMA or DMA Anion exchange and reverse phase solid phase extraction cartridges were used at concentrations above 2 mg l-1 interfered in the AsV analysis as low pressure chromatography columns for separating AsIII and AsV.FeIII A dual system composed of (a) HPLC followed by photo-oxidation at 254 nm, then HGAFS in tandem with (b) HG-cryogenic trapping/thermal desorption- AFS gave results similar to HPLC-ICP-MS for 8 As species. LODs were of the order of 0.5 ng ml-1 23 217 333 447 Operating parameters for FI-HGAFS on untreated samples were described in a conference presentation. Results compared favourably with mineralization procedures and allowed 2 mg l-1 to be determined in wine LODs of 10 and 20 ng g-1 were obtained for As and Se, respectively 174 UV photolysis coupled to HGAAS allowed the measurement of a range of species at LODs of approximately 5 mg l-1.Operating parameters for HPLCHGAAS were also reported FAB-MS was used to characterize arsenosugars 345 753 J.Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Drinking water As As Drinking water, urine and citrus leaf RMs Mushrooms As Urine As Urine As As Animal feed additives Carrots As Carrots As Fish, shellfish As Urine As Urine As Urine As Urine As Urine As Urine As Serum As As Blood, urine, tissues Chinese medicines As As Chinese herbal medicines B Biological tissues B SRMs B Tissues B Blood Beverages, foods Ba Tissues Ba Cod muscle Bi 754 J. Anal.At. Spectrom., 1999, 14, 717-781 MS;ICP;CE MS;ICP;HPLC Using microbore reverse phase ion-pairing HPLC-ICP-MS absolute LODs in MS;ICP;HPLC As species in 4 types of wild mushroom were determined using HPLC coupled AA;ETA; to the above named techniques. Inorganic arsenic and DMA were the main HPLC forms found MS;ICP;HPLC Increased concentrations of As species were found in urine specimens from subjects living in an area with old mines MS;ICP;ETV Urine was pipetted into an Ir-coated graphite tube.The analytes were vaporized into the ICP and the concentrations calculated by standard additions MS;ICP;HPLC An unusual As speciation study in that the species studied were the phenylarsonic acids added to poultry feed as growth promoters. It was necessary to use microbore HPLC to separate the additives from naturally occurring species present.The technique was proposed as a tool for investigating metabolites and degradation products MS;ICP;HPLC In contrast to the report in ref. 337, HPLC-ICP-MS studies of carrots found to MS;ICP;L MS;ICP;L AE;ICP;L MS;ICP;L MS;- ;HPLC AF;-;HPLC MS;ICP;HPLC of seaweed products AF;Hy;HPLC AF;Hy;HPLC AF;Hy;HPLC AA;Hy;L AF;Hy;L AF;Hy;L AE;ICP;HG -;-;- AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L XRF;-;S AA;ETA;L 317 Coupled CE-HG-ICP-MS was used to speciate AsIII, AsV, MMA, DMA, SeIV and SeVI.A microporous PTFE tube was used as a gas-liquid separator to eliminate interferences from 40Ar37Cl+ and 40Ar35Cl+. A compromise was necessary between complete reduction of SeIV and achieving optimum CE peak shape 448 the fg range were achieved for As and Sn species. Using the same separation approach coupled to ES-MS-MS up to 10 As species could be separated. The selectivity of this method allowed co-eluting As species to be measured 341 179 64 449 338 contain 0.6-0.8 mg g-1 As revealed the species present were not inorganic in nature.The source of the As was believed to have been DMA used to treat the crop growing in the field prior to the planting of carrots 337 An interesting study of As uptake from experimental plots containing diVerent soils artificially contaminated with As was reported. Carrots did not grow in soil with As concentrations above 400 mg g-1, but did grow in soils containing up to 338 mg g-1, although with reduced growth as As concentration increased.Only inorganic As species were detected in the carrots 450 171 A conference report described the application of open focused microwave preparation for extracting As species. Great care in selection of power and exposure time was required to prevent change of species 2 to the Ar plasma, or the addition of C2H5OH and Te internal 451 452 176 177 Addition of N standard to samples, gave accurate, precise results Structural information concerning As species was obtained using HPLC-MS with electrospray ionization Eleven As and four Se species were separated and determined after consumption Metabolism of As found in drinking water and seafoods was investigated.An on-line microwave heating arrangement, prior to HG and AFS, was used New, short HPLC columns made possible the rapid separation of AsIII, AsV, MMA and DMA with LODs of 1 ng ml-1 Various columns and conditions were investigated to develop a procedure for 453 178 the separation of As species present in urine following ingestion of arsenosugars in seaweed As binding proteins and As species in uraemic sera were separated by SEC, ionexchange or aYnity chromatography.Eluted fractions were digested prior to measurement of As. DMA concentrations were increased in specimens from patients receiving dialysis The hydride was formed after acid digestion (in Chinese) 454 455 3 456 Samples were digested with HNO and HClO4.Thiourea and ascorbate were added followed by 5% HCl. The solutions were sampled into an FI manifold for HG. The LOD was 0.1 ng ml-1 (in Chinese) Leaves, etc., were boiled in H2O, cooled, acidified with HCl and mixed with KI solution. An FI manifold was used to cause reduction with NaBH4 (in Chinese) 184 369 A number of analytical methods were reviewed.It was concluded that ICP-MS is the method of choice Samples were ashed, the ash dissolved in 5% mannitol-1 M HNO3, boiled gently and allowed to cool. The resulting solution was directly aspirated, yielding an LOD of 0.5 mg l-1 185 186 457 100-400 mg samples were prepared with an automated microdigestion procedure. An LOD of 0.01 mg ml-1 was reported After high temperature alkaline ashing, samples from animals fed boric acid throughout pregnancy were analysed A detailed survey, conducted in 1988, 1992 and 1996, of Ba intake in 16 test populations in Germany and Mexico was reported.One of the German groups was vegetarian and this group consumed twice as much Ba as the others. However, no adverse health eVects were predicted (in German) 458 301 Gunshot residues were analysed in frozen tissue specimens to help demonstrate entry wounds and shooting distances Diethyldithiophosphate complexes of Bi were formed in 0.5-4% HNO3 and adsorbed onto the walls of a knotted PTFE reactor.The complex was then eluted using 30% HCl directly into the cuvette of an ETAA spectrometer. During the ETAAS determination the next preconcentration step occurred. The LOD was 3 ng g-1 for 60 s loadingTable 1 (Continued) Plasma Bi Urine, medicines Bi Br Drinking and mineral water Water Br Water Br Drinking water Br Br Blood, plasma, urine, saliva Blood Br Plasma, urine CCa Plasma, cell membranes Cereals Ca Mineral water Ca Maize flour Ca Biological samples Ca Bone Ca Beverages Cd Blood, foods Cd Foods Cd Drinking water Cd Infant foods Cd Oranges Cd Peanut products Cd Tap water Cd Tea Cd Cd Traditional Canadian foods AA;Hy;L AA;Hy;FI the residue for HG and the LOD was 13mg l-1 (in Chinese) After digestion with acid an FI manifold was used to generate BiH3.Interferences were masked by addition of thiourea-KI.The LOD was 320 pg ml-1 MS;ICP;HPLC 2 very similar papers from the same co-workers reporting the use of microbore MS;ICP;HPLC Bromate was determined in ozonated drinking water using ID and direct HPLCICP-MS, yielding an LOD of 0.3 mg l-1. The ID procedure was compromised MS;ICP;HPLC A further paper on using HPLC-ICP-MS to speciate BrO3- in water that had by interference from the 40Ar dimer on mass 81 MS;ICP;L XRF;-;S XRF;-;L MS;-;S AA;-;- AA;-;L AA;F;L AA;F, air-C2H2;Sl MS;ICP;L MS;-;S AA;ETA;L AA;ETA;L MS;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L 183 Plasma samples were digested with HNO and HClO4. 10% HCl was added to 146 391, 392 species was reported. The LOD at m/z 79 was 50-65 ng l-1 (in German) column HPLC-ICP-MS to determine bromate. No interference from other Br 389 390 been disinfected with ozone.A novel device, the oscillating capillary, was used to overcome the need for injecting large sample volumes. The LOD was 393 2 mg l-1 and separation of BrO3- and Br- was achieved within 3 min 3- and Br- were determined by FI-ICP-MS using a microcolumn packed 105 BrOwith an anion exchanger. Malonic acid was used as carrier and eluent NaBr was given to human volunteers in experiments to estimate extracellular water 16 ml blood was placed into an aluminium cup to a depth of 20 mm.The 104 459 concentration of Br in specimens of normal blood was 2.5-11.7 mg l-1 AMS was used to provide very sensitive measurements of 14C, to follow the metabolism of labelled drugs Ca concentration changes during pregnancy were studied. Perturbed Ca homeost- 196 asis was observed in pre-eclampsia Ca and Mg were determined in wheat, barley and oats. Bioavailability of the 303 322 Ca and Mg were determined by FI-FAAS at LODs of 0.03 mg l-1 for both elements was assessed using a synthetic gastric digest elements.The sampling rate was 110 h-1. Lanthanum solution was injected before and after each sample to remove interferences 460 Powdered maize (0.1 g) was suspended in 0.15% agar and a 5 ml aliquot then mixed with 0.8 ml 0.1% agar-2 ml of 5% La3+ solution. An appropriate Ca standard was added, the solution diluted to 50 ml and Ca determined using standard additions. At 422.7 nm the LOD was 0.12 mg ml-1 (in Chinese) 83 90 Samples were dissolved in acid and analytes separated from the matrix by liquid- liquid extraction.Isotope ratio measurements were achieved with doublefocusing sector field ICP-MS Bone biopsy specimens were examined by AMS, using 41Ca to investigate the kinetics of bone resorption The results of a comprehensive study of Cd and Pb in Finnish beverages-beer, 408 461 carbonated drinks, juices, wines-was reported. The samples studied were found to make a negligible contribution to the diet To compare the performance of the named techniques, 418 samples of diet homogenate and blood were collected from Chinese and Japanese women and analysed.The ICP-MS results were 10-20% lower for Pb in blood and diet and Cd in blood than the ETAAS results, although equivalent results could be obtained following an unexplained mathematical correction 406 462 German Cd intake was calculated from market basket studies in the period 1988 to 1991 20 ml of sample was introduced into the autosampler without use of a modifier solution.No ash step was used to increase the rapidity of analysis. Using Zeeman-eVect ETAAS, Cd and Pb were measured at 228.8 and 283.3 nm yielding LODs of 0.05 and 0.8 mg l-1, respectively (in Chinese) 395 463 3 388 294 4. Following Samples were either mineralized with oxidizing acids or ashed at 500 °C prior to analysis using ETAAS with a L'vov platform.Neither baby foods nor selected raw materials gave cause for concern Samples were dried, ground, digested using HNO -HClO4, diluted to 25 ml with H2O and 10 ml taken for analysis by ETAAS at 228.8 nm. The LOD was 0.02 ng ml-1 (in Chinese) Levels of Cd were found to be between 0.013 and 0.031 mg kg -1 in a range of products purchased in Brisbane, Australia Water (150 ml ) was adjusted to pH 2 then mixed successively with 4 ml anion exchange suspension, 1.5 ml 20 nM APDC and 1.5 ml 3 M NaClO adjustment to pH 6 the solution was filtered.The filter was placed in a beaker, 1 ml of 0.1 M HCl containing 100 mg Pd applied to the filter and the beaker ultrasonically irradiated for 1 min; 20 ml of the suspension were taken for ETAAS. The LODs were 0.17 and 5.7 ng l-1 for Cd and Pb, respectively 464 Sample was charred, ashed at 550 °C, decomposed using HNO -HClO cooled, diluted in 0.5% HNO3, mixed with 0.2 mg l-1 PdCl 3 2-0.2 mg l-1 4, 4+1, 407 Mg(NO3)2 and Cd measured using platform ETAAS (in Chinese) Cd exposure from traditional foods, e.g., moose, caribou, was evaluated.Highest levels were found in liver and kidney of the named animals. The relatively high consumption of these organs could pose health eVects for a sub-group of the population studied 755 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Endive Cd Milk powder Cd Mussels Cd Vegetables Cd Urine Cd Hair, blood Cd Urine Urine, blood, hair Cd Cd Plasma, urine Cd Urine Cd Biological samples Cd Food Cd Urine Cd Urine Cd Cd Urine, faeces, intestinal fluid Liver, kidney Cd Kidney Cocaine, heroin Cd Cd Pharmaceuticals Cd Teeth, bones Cl Serum proteins Co Cinnarizine Co Preserved foods Co Milk products Cr 756 J.Anal. At. Spectrom., 1999, 14, 717-781 AA;ETA;LC AA;ETA;Sl AA;F, air-C2H2;L AA;F, air-C2H2;L AA;F;HPLC AA;ETA;L AA;ETA;L AA;CV;L AA;-;L AA;ETA;HG MS;ICP; FI-HG AE;ICP;ETV AF;Hy;L MS;ICP;L MS;ICP;ETV MS;ICP;SEC XRF;-;S XRF;-;S AA;ETA;L AA;F;L AE;DCP;L MS;-;S MS;ICP;LA AA;-;- AA;ETA;L AA;-;L 313 Endive was grown in Cd-enriched nutrient solutions.Following harvesting and extraction Cd species were determined using gel filtration LC coupled to ETAAS via a flow through cell. The results were used in an evaluation of the biochemical pathways that confer heavy metal tolerance on certain 465 4H2PO4, which also acted 158 Sample was suspended in a 1 mg ml-1 solution of NH plants as chemical modifier.Good recoveries were obtained for both Cd and Pb (in Chinese) An FI-FAAS system utilizing preconcentration on a minicolumn packed with poly(aminophosphonic acid) was described. Elution with concentrations of HCl above 0.5 M reduced recovery. Using smallest possible elution volumes resulted in an LOD of 0.56 mg l-1 319 191 122 A water-cooled stainless steel atom trap gave an LOD of 0.02 mg l-1 for a 1 min collection time.A laboratory made derivative measurement system was connected to the AA spectrometer A thermospray nebulizer to connect the HPLC column to the flame was designed and evaluated. It was reported that the sensitivity, at 3.7 pg ml-1, was 104 better than with conventional FAAS A tungsten coil atomizer was used to measure Cd after HNO3 digestion in a microwave oven.Because of vapour-phase interferences phosphate-based modifiers were not successful and 15 mg l-1 Pd solution was used Another description of a portable instrument with a tungsten coil atomizer 117 466 467 188 Samples were in thiourea, Ni, or thiourea-Ni-based media. An FI arrangement mixed the sample with 0.23 M HCl and then with NaBH4. The resultant vapour was fed to a heated quartz tube for atomization Metallothionein proteins were separated and quantified using covalent aYnity chromatography with thiol-disulfide interchange gels and AAS 2O: the hydride was trapped in the 12 Vesicular HG was utilized with urine and H graphite furnace for ETA giving an LOD of 10 ng l-1; the FI system had an LOD of 7 pg with a 50 ml sample 4)2HPO4 and 10 mg added to 2 468 0.2 M H2SO4.A portion was then treated with 30g l-1 KBH4 containing 5 Dried samples were powdered together with (NH a tungsten cuvette superimposed on a tungsten boat furnace. 80 ml TMAH was added and the cuvette heated to 130-150 °C. The temperature was further increased in stages to pyrolyse, ash and vaporize. The atomic vapour was transferred to the ICP in a stream of Ar and H The sample was low temperature ashed, the residue evaporated using H2SO4 and then ashed again at 600 °C. The residue was then shaken with 25 ml 0.2 M 2SO4, 5 ml of 0.5 g l-1 dithizone in CCl4 and diluted to 50 ml with further Hg l-1 KOH and analysed by AFS.The LOD was 0.12 mg l-1 190 3 67 3 Samples were analysed following 1+9 dilution with 1% HNO containing Rh as internal standard. Correction factors and instrumental conditions were established to minimize NaCl eVects 1% HNO was used as the chemical modifier in the ID measurement of Cd and Pb in SRMs and fresh urine specimens Porridge prepared from wheat intrinsically labelled with 106Cd was fed to infants 193 98 99 195 3 and adults in Cd balance studies In vivo measurements of liver and kidney provided LODs of 30 and 3 mg g-1, respectively.Results correlated poorly with individual Cd exposure estimates Accumulation in the kidney of smelter workers was monitored Solutions were prepared by dissolution in HNO and dilution with H2O. in cocaine and heroin at 5-45.6 and 10.2-192 mg kg-1, respectively (NH 143 4)2HPO4 was added to a concentration of 0.2% m/v.Cd was measured Solutions of drug compounds or extracts from pharmaceutical preparations were mixed with either [Cd(SCN)4]2- or [Zn(SCN)4]2- at optimized pH and then filtered. The Cd or Zn was measured in the filtrate to calculate the amount of metal taken for the formation of the insoluble ion associate. This provided an indirect determination of the drug concentration 91 58 145 A pyrolytic technique was developed and shown not to introduce contamination.Isotopes of Cl and I were extracted for measurement of 36Cl and 129I by AMS. Results were used to show exposure to radionuclides Proteins were separated by immunoelectrophoresis on agarose gels. The distribution of Co among the proteins was shown by LA-ICP-MS Powdered pharmaceutical preparations were dissolved in C2H5OH, diluted with HCl, filtered and treated with Co tetrathiocyanite solution. The complex was extracted with nitrobenzene and Co measured in the organic phase for the indirect determination of cinnarizine 469 306 Co, Cr and Ni were determined at 242.5, 357.9 and 232 nm, respectively, using ETAAS with pyrolytically coated tubes and a L'vov platform.A fast temperature programme obviated the requirement for an ashing stage Cr was determined by AAS after on-line preconcentration of CrIII on an activated column of alumina. The Cr was determined after electrochemical reduction of CrVI to CrIII.The original CrIII in the sample was also determined (in Slovakian)Table 1 (Continued) Blood Cr Foods Cr Grapes, wine Potable water Cr Cr Preserved foods UHT milk Cr Cr Urine Cr Urine Cr Hair, sweat, serum Cr Semen Cr Cr Biological specimens White asparagus Cr White asparagus Cr Cr Cr Biological specimens Body fluids and tissues Cr Biological materials Tissues Cr Green vegetables Foods Cu Cu Virgin olive oil Cu Cu Cu Serum proteins Plasma, urine Malt beverages Cu Water, wine Cu Plasma, urine Cu Urine Semen Amniotic fluid Cu Cu Cu Cu Biological specimens Tissues Tissues Cu Cu Cancer tissues Cu AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;F, air-C2H2;L AA;F, air-C2H2;L MS;ICP;L MS;ICP;L MS;ICP;ETV LMMS;-;S AA;-;- AA;-;- AA;-;L AA;-;- AA;-;L AA;ETA;L AA;F;L AA;ETA;L AE;ICP;L MS;ICP;L Samples were diluted 20- and 10-fold in 0.05% HNO3 for plasma and urine, respectively. 89Y was added as internal standard. 1-2 ml samples were taken using an FI-DIN AA;ETA;L See Cr, ref. 472 AA;ETA;L See Cr, ref. 473 MS;ICP;HPLC Metal binding proteins were separated by SEC. Caeruloplasmin was shown to AA;ETA;FI AA;F;L AA;F;L XRF;-;S 470 471 3-H2SO4 (6+1) and digested overnight. HNO3 Contamination from three types of venepuncture needles was assessed and found to be absent or negligible.The analytical method used had an LOD of 0.3 mg l-1 Samples were mixed with HNO was added dropwise and refluxed until the appearance of white fumes. The digests were diluted to final volume with H2O. The LODs were 1.1 and 1 mg kg-1 for Mn and Cr, respectively, based on 2 g of sample in a final 374 305 volume of 20 ml The Cr content of 79 wines and 12 grape varieties was determined Water, 250 ml, was passed through a 1.5×0.1 cm column containing 2 g ZnO which retained the CrIII. HNO3-H2O2, 2+1, was added to the eluate and the solution evaporated to 5 ml on a sand-bath.Following dilution to 10 ml Cr and CrVI were determined by ETAAS. The LOD was 0.01 ng ml-1 for CrVI. 469 307 2 CrIII was determined by diVerence See Co, ref. 469 CrVI was determined by protein precipitation and then elution through an NH 3. Without the precipitation step recoveries were less than 25%.The highest level found was 1.2 mg l-1 column using HNO 472 198 Specimens from subjects with occupational exposure were acid digested with microwave heating Reference concentrations in Italian subjects were determined. The LOD was 0.05 mg l-1 and results were from none detected to 0.24 mg l-1 Age-related concentration decreases in specimens from more than 40 000 subjects 138 473 3 at 85 °C, diluted with H2O and analysed.were reported The semen was heated with HNO Concentrations were not related to sperm quality 123 474 Various chemical modifiers were investigated for the measurement of Cr in acid digested materials, using a tungsten coil atomizer. Pd was the most eVective Dried, homogenized sample was sequentially ashed, dissolved in H2O-65% HNO3-30% HCl, 2+1+1, evaporated to dryness, the residue ashed at 460 °C and the resulting ash redissolved in the acid mixture. At 357.9 and 232 nm 475 the LODs were 0.04 and 0.6 mg g-1, respectively The same research group as in ref. 474 reported the eVect of freezing and storage on Cr and Ni distribution. Statistically significant diVerences were found for Ni levels Carbon-based species which interfere with the measurement of 52Cr and 24Mg 50 51 were removed when a cool Ar-ICP was used Ways to reduce polyatomic interferences were developed. Vapour-phase acid The ArC+ eVect on 52Cr was corrected mathematically.Accurate results were digestion limited contamination and interferences associated with C and Cl. 197 obtained with CRMs A Mo or W metal filament was used for ETV to avoid the introduction of C and the formation of C-containing polyatomic interferences Various Cr species were identified in tissue sections with mm resolution. Samples 199 476 477 were irradiated at 266 nm and the species were detected by TOF-MS Cu and Zn in vegetables commonly consumed in Ghana were determined Human diets from 12 locations in Austria were measured for their Cu and Ni content (in German) The influence of Cu and Fe on oxidation of 47 oil samples was evaluated 362 (in Italian) The distribution of Cu among serum proteins was determined See Cd, ref. 467 203 467 384 Samples were diluted 5-fold and analysed directly using ETAAS with NH as the chemical modifier. The LOD was 5 mg l-1. The maximum level found 4H2PO4 376 was 86 mg l-1 The above techniques and potentiometry, diVerential-pulse polarography and catalytic procedures were compared for determining Cu (in German) 56 472 473 478 32 be a major carrier for Pb An FI manifold was constructed which included a 'knotted reactor' for the adsorption of an APDC chelate. With a 30 s sampling time the preconcentration step produced a 44-fold enhancement factor and an LOD of 6 ng l-1 The samples were from a case of fatal Ag poisoning.See Ag, ref. 273 Samples from sheep with perturbed Cu status were digested with HNO 273 240 3 4 and HClO Biopsy materials were analysed by TRXRF (in Japanese) 200 757 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Vitamin tablets Cu Serum Cows milk FF ee Serum Fe Lung cells Fe Fe Histidine preparations Virgin olive oil Biological samples FF ee Serum Ga Blood Ge Hair Hg Hg Fruit, vegetables, cellulose Fish Hg Hg Deer liver and heart Fish, hair Hg Tap water Hg Hair Hg Hg Grain, cereal products Hair Hg Hg Biological specimens Biological samples Hg Hg Blood, plasma, urine Tissues Hg Hg Histidine preparations Fish Hg Yeast cells Hg Hg Urine, plasma, serum 758 J.Anal. At. Spectrom., 1999, 14, 717-781 AA;F;L AA;ETA;L AA;F;L MS;ICP;L AA;-;-; AA;-;L AA;-;L AA;ETA;L MS;ICP;L AF;ETA;L AA;-;- AA;-;L AA;-;L AA;CV;L AA;CV;L AE;ICP;L AA;CV;L AA;CV;L AE;ICP;L MS;ICP;ETV AA;CV;L AA;CV;L AA;CV;L AA;CV;FI AA;-;L AA;CV;L AA;CV;L AA;ETA;GC 201 A suspension of tablets in H2O was sampled with an FI system which included an electrodialyser to remove suspended solids.The system was linked to an AA spectrometer for measurement of the Cu See Al, ref. 216 Fe and Zn determinations using a high performance nebulizer were compared 216 318 217 to those of a standard nebulizer with glass impact bead. LODs were 0.024 and 0.002 mg ml-1 for Fe and Zn, respectively, for the former nebulizer and 0.044 and 0.011 mg ml-1 for the latter.The Cu and Zn distribution in cows milk was also reported Results for measurement of 54Fe and 57Fe were improved when protein was removed, membrane desolvation was employed and sample was introduced 215 144 by an ultrasonic nebulizer Asbestos silicates were included with cultured cells in an investigation of the mechanisms of cell damage.Changes of Fe and Mg concentrations were observed TLC was used to remove interferents. The extract was then reacted with FeIII. Filtrate and precipitate were separated and the Fe measured in both fractions 362 124 to calculate the histidine concentration in the original specimen See Cu, ref. 362 Further work with the glassy C column atomizer, giving no background absorbance, was reported Specimens were diluted 1000- to 10-fold. 37Cl16O caused interference on 67Ga. 208 2 127 141 Measurement on 71Ga was preferred, therefore (in Japanese) A LEAF system with a copper vapour laser was used. An LOD of 1.0 pg was reported Prenatal exposure to methylmercury from fish diets was assessed by analysis of maternal hair. The exposure to methylmercury did not influence the age at 479 480 The eVect of Ca, Cu, Mg and Zn ions and pH on the adsorption of Hg2+ by which infants began to walk or talk cellulose and other materials was investigated. The presence of the ions increased adsorption.The results were compared with those for various food products and cellulose dietary fibre. In all cases the adsorption was higher than that for cellulose alone (in Polish) The level of Hg in various fish species and monthly variations in the levels were reported The holding time for total Hg in the above tissues was calculated using EPA 481 482 method 245.6 A multi-vessel system for determination of Hg by CVAAS and ICP-AES 349 142 Hg2+ and methylmercury were adsorbed onto a column packed with dithizone was developed immobilized onto sodium dodecylsulphate coated alumina.The trapped Hg was then back extracted into aqueous solution using 1 M HBr Samples from mothers and infants living in the Amazon region were digested using alkaline conditions See As, ref. 445 445 234 The sample was placed into a minitube furnace and heated to 950 °C in a stream of O LOD was 19 pg 233 4 483 2-Ar.The gas flow transferred the volatilized Hg to the ICP-MS. The Samples were heated at 90 °C with acids and then KMnO4 added. Oxalic acid was added to neutralize KMnO for CVAAS. Sensitivity was increased by the presence of H2SO4 A microwave heating system was used to digest specimens. Hg vapour was formed in a commercial accessory and preconcentrated by gold amalgamation.The final measurement was made after thermal desorption Markers of the immune response to Hg, seen in some individuals, did not 238 16 144 152 correlate with Hg in body fluids Following solubilization with TMAH an FI arrangement was set up in which reduction 4 and vaporization of the Hg. An LOD of 0.1 4mg l-1 was reported KMnO was used to cleave the C-Hg bond. NaBH was then added for TLC was used to remove interferents.The extract was then reacted with FeIII. Filtrate and precipitate were separated and the Hg measured in both fractions to calculate the histidine concentration in the original specimen Organomercury species were extracted using toluene and the extract treated with a 1% cysteinium chloride solution. After shaking and centrifugation the cysteine solution was analysed using a commercial Hg analyser. The LOD was 0.01 ng Hg 35 Yeast cells were immobilized onto silica gel and the powder assembled into a column which was incorporated into an FI manifold for separation of Hg species and generation of atomic vapour 484 Methylmercury and dimethylmercury were extracted into benzene and xylene, respectively.The extracts were injected onto a 3% Carbowax 20M on Chromosorb W/AW DMSC (60-80 mesh) column with a temperature rise from 60 to 160 °C. Ar carrier gas carried the eluent to the atomizer for atomization and measurement at 700 °C.The LOD was 0.2 ng (in Chinese)Table 1 (Continued) Biological samples Hg Hg Chinese herbal medicines Biological samples Hg Fish Hg Fish RMs Hg Hg Fish, shellfish, human hair Hg Biological specimens Hg Biological specimens Urine Hg Blood, urine, fish Hg Biological samples Hg Hg Biological fluids, tissues Chinese medicines Hg Hair Hg Kidney cells Hg Serum I Foods II Foods I Food CRMs II Nutritional and biological CRMs Nutritional and biological CRMs I Plasma, serum, blood, urine AA;Hy;GC AE;ICP;CV AE;ICP; FI-CV AE;MIP;GC AE;MIP;L AF;-;GC MS;ICP;GC MS;ICP;ETV MS;ICP;ETV MS;ICP;L AF;CV;L AF;CV;L AF;CV;L XRF;-;S XRF;-;S AE;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L NAA;-; - MS;ICP;L 485 3 4 KBH was added to the sample to give the hydride form of CH HgCl.The hydride was collected in a fused silica fibre, part of a laboratory made solid phase extraction unit.After collection the fibre was transferred to the GC column and the hydride thermally desorbed. The LOD was 26 ng See As, ref. 456 456 235 4 153 A column containing silica gel functionalized with methylthiosalicylate was included in an FI manifold for separation and preconcentration of the Hg, which was eluted with thiourea and reduced with NaBH Following microwave assisted digestion samples were either ethylated using Na tetraethylborate, extracted into hexane and injected into a GC-MIP-AES or treated with NaBH and analysed using purge and trap GC-MIP-AES, yielding LODs of 3 and 12.54 pg g-1, respectively 349 351 2O. Methylmercury was ethylated and the 486 Rapid microwave digestion using TMAH was followed by ethylation, extraction of Hg species into hexane and flash isothermal separation Sample was decomposed using methanolic KOH at 70 °C, cooled and mixed with concentrated HCl and H resulting species, ethylmethylmercury(II) adsorbed onto a Tenax tube which was then connected to a GC and desorption eVected by heating to 220-250 °C.The LOD was 0.5 pg. Interfering metal ions were removed by EDTA (in Chinese) Organomercury species in the sample were collected at -80 °C and heated for rapid injection onto a multi-capillary GC column. The separated species/ isotopes were measured by ICP-MS with an LOD of 15 pg 65 66 TMAH was used to solubilize tissues. A portion, with iodoacetate, sodium thiosulfate and acetic acid, was dried and heated.At this point methylmercury iodide was volatilized, leaving only the inorganic Hg. Total Hg concentrations were given when this treatment was omitted For this ID analysis a modifier with Pd, Mg(NO3)2 and 2% HCl was found to give best results. Accurate results with an SRM were obtained and the LOD was 0.02 ng ml-1 151 By complexing Hg with (NH4)2H2EDTA in the presence of NH3 it was possible to achieve wash out times of <130 s for concentrations above 30 mg l-1.A novel disinfection procedure for blood and urine using Virkon, a virucide, was also reported. Excellent QC results were detailed. The application of the method to various Hg studies were described 22 232 3 455 3 An on-line microwave digestion system was described for heating the sample with potassium bromide-bromate to oxidize methylmercury.The HgII was reduced by SnCl2 50 mg samples were digested with HNO and H2SO4 in heated sealed containers, reduced with SnCl2 and the Hg determined Samples were digested with HNO and HClO4. Thiourea and ascorbate were added followed by 5% HCl. The solutions were sampled into an FI manifold for vapour generation. The LOD was 0.02 ng ml-1 (in Chinese) 108 109 Cross-sectional analysis using SR-XRF showed that Hg accumulated in the inner cortex following absorption, and on the cuticle if there was exogenous exposure, to methylmercury. The profile along the hair length could also be determined Structural changes were observed in apoptopic proximal tubular cells of HgCl2- treated animals.Accumulation of Hg was evident in the altered cells, suggesting a relationship between apoptosis and Hg 47 346, 487 Serum proteins were precipitated and removed by centrifugation. The supernatant was aspirated to measure iohexol indirectly as I A conference report and then full paper on extraction of I using TMAH at 90 °C.For complete extraction from all the matrices studied it was necessary to have a sample particle size of <300 mm. The LOD was 30 ng g-1 348 3 and good agreement was obtained in comparison with conventional digestion procedures 0.5 g of sample was weighed into a PTFE liner, HNO -HClO4, 3.5+1.5 added and the insert placed inside a steel bomb at 160 °C for 4 h.Rigorous cleaning with TMAH was necessary to overcome blank problems 347 Sample, 129IO3- spiked solution and H2O2 were heated with TMAH in a closed PTFE vessel at 90 °C for 3 h, or the sample plus spike were digested using Q-ICP-MS, yielding an LOD of 8 ng g-1 H2SO4-HNO3 in a microwave. The 127I5129I ratio was measured using a 210 2 424 The samples were combusted in a stream of O and the products collected in a 5% H2O-tertiary amine solution. The same system was proposed for other elements A conference report related to the work described in ref. 210. The results obtained by the method described were compared with those obtained by NAA. Low recoveries were reported for biological CRMs due to incomplete extraction of I 213 1% TMAH was used as diluent and Rh was included for internal standardization 759 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Urine Urine III Tissues, biological fluids Tissues I Teeth, bones Thyroid tissue IIIn Breast milk, infant formula Serum K Tissues Biological samples Urine KKLa Mg Leucocytes, erythrocytes Cereals Clinical samples Mg Mg Mineral water Plasma, red cells Mg Mg Mg Serum, red cells, hair Lung cells Serum Mg Mg Bone Mg Mg Mg Platelets, plasma, red cells Biological specimens Plasma, urine Mg Mg Mn Biological samples Biological specimens Foods Hair Mn Mn Pharmaceuticals Mn Tea leaves, tea Mn Liver Mn Wine Mn Tea leaves, tea Mn Foods, beverages Mo Tissues Mo Foods, beverages Mo 760 J.Anal. At. Spectrom., 1999, 14, 717-781 MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;-;S XRF;-;S AA;ETA;L AE;F;L AA;F;L MS;ICP;L AE;ICP;FI AA;-;- AA;-;L AA;F;L AA;F;L AA;F;L AA;F;L AA;-;- AA;ETA;L AE;ICP;L AE;DCP;L MS;ICP;L MS;ICP;L MS;ICP;L AA;ETA;FI AA;ETA;L AA;ETA;L AA;F;L AA;F;L AA;ETA;L AE;ICP;L AA;F;L AA;-;L AA;ETA;L AE;ICP;L 212 488 solution containing 129I.The LOD was 3 Standard additions calibration was employed and recoveries of 101-113% were obtained. The LOD was given as 0.000 38 mmol l-1 Samples were diluted with an NH 0.02 mmol l-1 A mixture of water-soluble tertiary amines at pH 8 was used for sample 18 211 2 dissolution. This mixture, sold as CFA-SC, allowed simultaneous measurement of I and other elements To avoid loss of volatile I, samples were oxidized in a stream of O and the products collected in a 5% tertiary amine solution (CFA-C).This solution was used for ICP-MS and measurement of I. Other elements could be 91 214 209 determined at the same time See Cl, ref. 91 Age-related changes in concentration and total amount of I in the thyroid were determined Ni(NO3)2 was applied as chemical modifier in the Zeeman-eVect ETAAS determination of In in breast milk and infant formula; at 325.6 nm the LODs were 2 and 2.5 mg l-1, respectively.The samples, 400 ml, were diluted with 200 ml 4% Triton X-100-200 ml H2O, injected into the furnace, dried and 10 ml 274 of 5000 mg l-1 Ni solution added Measurements using ion selective electrodes were compared with results given by flame photometry The samples were from a case of fatal Ag poisoning. See Ag, ref. 273 273 83 218 3 See Ca, ref. 83 La in 1.0 l of urine was extracted at pH 9 into 100 ml quinolin-8-ol in CHCl 2O at pH 4.5.This solution was readjusted to pH 9, 3 and back-extracted into H ethanolic quinolin-8-ol was added and pumped through an ion exchange column. The retained La was eluted with HNO into the ICP with an LOD of 0.09 ng ml-1 Cells were obtained by centrifugation and then lysed for measurement of Mg. 489 303 225 Concentrations were higher with heparinized compared with defibrinated blood See Ca, ref. 303 Methods for measurement of Mg in clinical specimens were comprehensively reviewed See Ca, ref. 322 Samples were from healthy subjects, patients with steatosis and those with 322 490 227 alcoholic liver cirrhosis Mg supplements were given to hyperactive, Mg-deficient children. Hair Mg concentrations increased and the hyperactivity decreased See Fe, ref. 215 Samples diluted with pH 7.4 buVer were added to a TSK-gel DEAE-5PW ion 215 226 229 exchange column.Mg species were eluted and the fractions analysed oV-line by ETAAS. Mg was associated with albumin and globulin proteins Results from an experimental study of variations of dietary Al, Ca and Mg were reported (in Japanese) Platelet Mg concentrations were low in diabetic compared with control subjects 491 See Cr, ref. 50 50 77 83 32 Mineralized samples were analysed in a study using stable isotopes to evaluate absorption and bioavailability See Ca, ref. 83 An FI manifold was constructed which included a 'knotted reactor' for the adsorption of a quinolin-8-ol chelate. With a 30 s sampling time the preconcentration step produced an 8-fold enhancement factor and an LOD of 29 ng l-1 471 231 3 See Cr, ref. 471 After digestion with HNO and H2O2 and evaporation to dryness the residue 3. 5ml were placed onto a graphite probe for 230 was taken into 1% HNO atomization within the furnace.The LOD was 11.69 pg (in Chinese) An FI system was prepared for mixing specimen solutions with MnO2 at pH 4-5. The excess Mn was directed to the AA spectrometer for the indirect determi- 492 493 nation of vitamin B6 (in Chinese) Mn was speciated using ion exchange chromatography and FAAS. Full experimental details were given and Mn bioavailability discussed Modifications to the vertical glassy carbon atomizer were described: an open tubular column was used; the sample cup was held by a glassy C rod; a lower graphite electrode was included; an Si-controlled rectifier supplied an increased 494 Mn and Pb were determined at LODs of 0.4 and 5.5 mg l-1, respectively output rating (in Japanese) 492 414 (in Chinese) Mn was speciated using ion exchange chromatography and FAAS.Full experimental details were given and Mn bioavailability discussed Daily dietary intake of Mo in Belgium was estimated by duplicate portion sampling.Portions were freeze-dried and sub-samples digested using 240 4 3 413 HNO3-H2O-H2O2 in a microwave oven Tissues from sheep given ammonium tetrathiomolybdate to treat Cu toxicity were prepared by digestion with HNO and HClO Daily dietary intake in Mexico and Germany was estimated using duplicate portion sampling. Levels were estimated in 14 groups of adults in 1988, 1992 and 1996. Intake increased considerably over the duration of the studyTable 1 (Continued) Mo Mo Na Ni Ni Ni Ni Ni Ni Ni Ni Ni Ni Ni Ni PPPb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Pb Foods Urine Serum Chicken organs and tissues Foods, faeces, urine Green vegetables Vegetables Foods Preserved foods Sterilized milk Hair Biological specimens White asparagus White asparagus Tissues Edible oils and fats Edible fats and oils Blood Beverages Blood, foods Drinking water Infant formula Powdered drinks, honey, syrups Tap water Water White wine Wild mushrooms Wine Wine Milk powder Drinks Fruit juice, milk Rice flour Water Water AE;ICP;L MS;ICP;L AE;F;L AA;-;- AA;-;- AA;-;- AA;-;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;Sl AA;ETA;FI AA;F, air-C2H2;L AA;F, air-C2H2;L LMMS;-;S XRF;-;- AA;ETA;L AA;-;- AA;ETA;L AA;ETA;L MS;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;Sl AA;F, air-C2H2;L AA;F;L AA;F;L AA;F;L AE;ICP;L 495 239 Mo in tar-contaminated soil and fruit and vegetables grown on the soil was determined.Diet evaluation indicated no risk was posed to human health (in German) 95Mo and 98Mo were measured in urine samples diluted 1+9 with 2% HNO3. A positive correlation with butter consumption was noted See K, ref. 274 The eVect of supplementing chicken diet with NiSO ·7H 274 496 4 2O, up to toxic levels, on Ni and Zn concentrations in a wide range of organs was investigated.Ni increased in all organs, whilst Zn showed more variable behaviour (in German) 497 476 299 Ni content in 7-day diets, faeces and urine was measured for 14 volunteers from Saxony. Most dietary Ni was eliminated in the faeces, but there was a positive Ni balance. The daily intakes were several times higher than daily allowances See Cu, ref. 477 Ni was preconcentrated using activated C following ashing and decomposition 3-H2O2 (2+1). Various experimental parameters were evaluated with HNO Ni was determined in 8 types of food. The LOD was 1.6 mg l-1 (in Chinese) 498 469 499 13 See Co, ref. 469 44 brands from 32 Spanish provinces were surveyed. The average Ni content was 60.7 ± 35.3 mg kg-1 (in Spanish) 0.1 g hair powdered in a zirconia ball mill was suspended in 25 ml H2O and 32 stabilized by addition of glycerol.Mg(NO3)2 was used as chemical modifier An FI manifold was constructed which included a 'knotted reactor' for the adsorption of an APDC chelate. With a 30 s sampling time the preconcentration step produced a 21-fold enhancement factor and an LOD of 7.6 ng l-1 See Cr, ref. 474 474 See Cr, ref. 475 475 199 361 500 See Cr, ref. 199 Samples were solidified with 15% stearic acid and WDXRF measurement performed in disposable liquid cells.The LOD was 2 mg kg-1 for both P and S 3-30% H2O2, 4+2, and digested using Sample, 0.5 g, was mixed with 65% HNO microwave heating. The wavelength of measurement was 213.6 nm (in Czech) Specimens from infants living in urban and rural areas of Chile were analysed See Cd, ref. 408 See Cd, ref. 461 501 408 461 462 394 323 See Cd, ref. 462 A study of the practice of infant formula reconstitution revealed that 2 of the 40 samples analysed contained Pb concentrations above approved safe levels.The samples were found to have been reconstituted using tap water drawn from houses with plumbing over 20 yr old Samples were dissolved in H2O, acidified using 0.2% HNO3 and injected into an 3)2 were 294 324 end-capped transversely heated cuvette. Carbon build-up was minimized by using two pyrolysis steps, 600 and 1000 °C. 5 mg Pd+3 mg Mg(NO used as modifier See Cd, ref. 294 Refractory elements-Hf, Nb, W, Zr-were used to treat the surface of a pyrolytically coated graphite furnace.Treatment with W allowed injection 380 399 volumes up to 100 ml, yielding an LOD of 0.02 mg l-1 Pb was measured in Chinese white wine at an LOD of 31 pg (in Chinese) 95 samples of 13 wild species in Northern Spain were analysed. Average levels were 1 mg kg-1 dry weight, with a maximum of 10.43 mg kg-1 17 laboratories participated in an international collaborative study of an ETAAS 423 378 determination for Pb in wine.The method, incorporating a novel matrixmatching procedure, gave good agreement between participants An exhaustive study of the source of elevated Pb levels in wine was reported. Analysis of 7000 wines showed that neither atmospheric pollution nor the tin-lead covering of the neck were responsible. The vintage and wine colour most strongly correlated with the elevated levels and inspection of the wineries 465 300 giving these levels always revealed the presence of brass tubes and faucets See Cd, ref. 465 100 ml samples were neutralized, shaken with 15% Mg(NO3)2-20% NaOH, 1+1, left for 1 h, centrifuged and the precipitate dissolved in HNO3 and diluted to 10 ml with H2O.Recoveries were in the range 90.5-112% (in Chinese) 298 320 See Al, ref. 298 Flour was digested using HCl-HNO3, diluted with a solution containing 200 g l-1 KI and injected into an FI system incorporating on-line extraction using IBMK.The LOD was 2.8 ng ml-1 (in Chinese) Samples were acidified, neutralized and pH adjusted to 5.5 using 1 M ammonium 295 293 acetate buVer. They were then pumped through a column containing Amberlite resin. The Pb was then eluted using 1 M tetrabutylammonium bromide and the resulting complex extracted in IBMK in a 30 cm reaction coil. The preconcentration factor was 550 and the LOD 0.3 mg l-1 A novel ion-exchange resin based on 'cavities' designed to exactly fit the charge, co-ordination number, geometry and size of Pb2+ was described.It was claimed to be almost interference free 761 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Blood Pb Calcium pills Pb Pb Calcium pills and supplements Maple syrup Pb Vegetables, SRMs Pb Wine Pb Hair, blood Pb Blood Pb Blood Pb Blood Blood Blood Pb Pb Pb Blood Pb Urine Pb Urine Pb Urine Urine Amniotic fluid Plasma Pb Pb Pb Pb Plasma proteins Pb Blood, tissues Pb Bone Pb Pb Blood, bone, tissues Biological samples Herbal medicines Pb Pb Ca drugs Pb Pb Antacids, dietary supplements Bone Pb Biological RMs Pb Tissues Bone Pb Pb Tissues Bone Pb Pb 762 J.Anal. At. Spectrom., 1999, 14, 717-781 MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L MS;ICP;L MS;ICP;L MS;ICP;L AA;F;L AA;ETA;L MS;ICP;L AA;Hy;FI MS;ICP;ETV See Cd, ref. 67 MS;ICP;ETV See As, ref. 64 MS;ICP;HPLC See Cu, ref. 478 MS;ICP;HPLC Distribution of Pb among caeruloplasmin and other plasma proteins was determined by SEC. See also Pb, ref. 478 MS;ICP;HPLC Samples were collected from subjects who ingested contaminated soil. Plasma MS;-;- AA;ETA;L MS;ICP;L AE;ICP;S AA;F;L AA;ETA;Sl MS;ICP;L MS;-;S MS;ICP;L LMMS;-;S XRF;-;S XRF;-;S XRF;-;S 220 149 Samples were from Ecuadorian children living in areas with intensive occupational use of Pb.The isotope ratios in blood matched those of contaminated soils A method was described for determining Pb in calcium pills and antacids. The method was required in response to legal proceedings in January 1997 when 10 companies were reportedly sued for not warning consumers about allegedly high levels of Pb in their supplements 150 3 at 230 °C and 1770 psi. Matrix matched 3 502 Pb concentration and isotope ratios were measured in 9 brands of Ca supplement following digestion in 2 ml of HNO standards using high purity CaCO were employed.Moderate levels were found in samples originating from oyster shell Samples were digested in a microwave using HNO3 as acid. 8 brands of commercial syrup contained levels in the range 18-367 ng g-1 A tungsten coil was placed within a glass chamber which was connected directly 330 and transported at 1.5 l min-1 by a 95% Ar-5% H flow.Quantification was to the plasma torch via a 750 mm tube. Sample was vaporized from the coil 2 315 achieved using isotope dilution procedures. For 208Pb5207Pb the precision was 1-2.5% SEC-ICP-MS was used to speciate Pb in wine. A study carried out on 20 wines suggested that no free Pb was present in wine. 40-95% of Pb was complexed with rhamnogalacturon II and the remainder with other unidentified species A comparison of three chemical modifiers used with a tungsten coil atomizer 121 was reported.Pd(NO3)2 gave results that were more precise and accurate than did (NH4)2HPO4 or NH4H2PO4. The LOD was 1 mg l-1 Recent work to improve the sensitivity and accuracy of measurements using 219 116 tungsten filament atomizer were reported Another report of a small portable AA spectrometer based on a tungsten coil atomizer A further presentation of a portable tungsten coil atomiser AA spectrometer Blood specimens were digested with microwave heating. 208Pb was measured 120 503 80 81 33 Samples were digested in acid and analysed by ICP magnetic sector-MS Pb isotope ratios were measured with good accuracy and precision using double focusing magnetic sector ICP-MS Sample enrichment was achieved with a supported liquid membrane. The membrane solution was 40% m/m di-2-ethylhexylphosphoric acid in kerosene 504 from which the Pb was back extracted into 1 M HNO3.Enrichment factors of up to 200 were obtained with extraction times of 0.5-4 h. This allowed LODs of 0.1 and 6 mg l-1 for ETAAS and FAAS, respectively. Results compared well with those obtained by ICP-MS An FI-HG manifold, which used a ferricyanide oxidizing agent, was reported. The sample was led to a heated quartz tube atomizer and the LOD was 80 ppt 67 64 478 221 505 222 223 3 volume of H proteins were separated by ion exchange chromatography and SEC.Most of the lead was associated with caeruloplasmin TIMS was used to measure 204Pb, 206Pb and 207Pb in a study to monitor movements of Pb between tissues during pregnancy. A monkey model was used for this investigation 5-20 mg ashed bone was dissolved in 5% HNO and diluted with an equal 2O 78 12 126 3 Magnetic sector ICP-MS was used for precise measurement of Pb isotopes in specimens collected in studies of the eVectiveness of chelation treatment See Cd, ref. 12 1 g sample was ashed at 450 °C and further digested with HNO and HClO4. The residue was taken into 2% HNO and aspirated into a vanadium-coated slotted quartz tube. The LOD was 8.37 3 mg l-1 Ca drugs were ground to produce particle sizes of around 3 mm. Suspensions of 15 the powders were atomized from a molybdenum tube with thiourea chemical modifier. H2 added to the Ar increased the analytical sensitivity Acid dissolution was the only preparation required 148 Pb isotopes in SRM 1400 Bone ash were measured by TIMS 131, 132 79 Pb isotopes, at concentrations of 1-10 ppb, were determined by magnetic sector MS for isotope tracer studies. 209Bi was the internal standard and the LOD was reported as 0.013 ppb total Pb See Cr, ref. 199 In vivo determination of Pb in the finger bones of persons with occupational 199 224 exposure was reported. The LOD was 25-30 mg kg-1 458 97 See Ba, ref. 458 Neurophysiological studies were undertaken in subjects with occupational Pb exposure. Results were evaluated in association with long-term exposure as given by in vivo determination of Pb concentrations in tibial and calcaneal boneTable 1 (Continued) Bone Pb Bone Pb Bone Pb Teeth Pb Finger bone Urine Pb Pd Urine Pd Blood Pt Pt Plasma ultrafiltrate Plasma Pt Tissues Pt Plasma, tissues Pt Wine Pt Blood, urine Pt Urine Urine Tissues Pt Pt Pt Urine, blood Pt Anti-cancer drugs Pt Lipids, emulsions Pt Pt Tissue, in vivo Blood, urine Pu Urine Pu Foods Rb Serum REE Blood, urine Plasma, tissues REE REE Tissues Rh SRh Sb Sb Urine Edible oils and fats Red cells, serum Water, red blood cells, serum Water Sb Tap water Sb XRF;-;S XRF;-;S XRF;-;S XRF;-;S XRF;-;S MS;ICP;L MS;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L MS;ICP;L MS;ICP;L MS;ICP;L AA;ETA;L AF;ETA;L laser and a detection limit of 50 fg was achieved MS;ICP;HPLC Inactive species in Pt anti-cancer drugs were separated and identified.A sensitive analysis was established with an LOD of 40-50 ng l-1 Leakage of Pt and silicones (measured by GC-MS) from breast implants into MS;ICP;L XRF;-;S MS;ICP;L MS;ICP;L AA;-;L MS;ICP;L MS;ICP;L MS;ICP;ETV AE;ICP;L MS;ICP;L XRF;-;- AA;ETA;L AA;ETA;L AA;Hy;HPLC SbIII and SbV were determined at LODs of 2 and 1 mg l-1, respectively, using was reported for all 3 sample types AA;quartz furnace;GC 96 92 Clinical application of in vivo bone Pb measurement in children and other nonoccupationally exposed groups was discussed Preliminary evaluation of a new XRF system, using bone phantoms, were reported.The results predict that a lower LOD, using less excitation energy, should be possible Tibial Pb was measured in vivo.Instrumental features were optimized using the 94 101 Monte Carlo code Children's teeth were irradiated and the X-ray spectra recorded. An aqueous calibration material was used and results were expressed as mg Pbg-1 per accumulated year. Data from China, Russia and the USA were compared Accumulation in bone was determined in smelter workers A UV photolysis procedure was the only preparation required. Concentrations 99 70 69 in untreated subjects were 32.7-219.7 ng l-1 and the LOD was 0.17 ng l-1 UV irradiated specimens were analysed.Q-ICP-MS and magnetic sector field ICP-MS were compared and superior results were found using ultrasonic nebulization high resolution ICP-MS The pharmacokinetics of total and unbound Pt species were investigated in 244 506 patients treated with carboplatin, to relate treatment response to dose A study of the maximum tolerated dose, toxicity, pharmacokinetics and pharmacodynamics of an orally administered drug, JM216, was reported The relationship between Pt pharmacokinetics and the formation of Pt-DNA 246 245 adducts was investigated in children treated with Pt Tumour tissue, 0.1 g, and 1 ml HNO were heated at 37 °C for 2 d.Pt was measured using aqueous standards and 3 the LOD was 3 mg l-1 A new cisplatin formulation with microcrystals suspended in oil was administered 507 373 243 to animals.The pharmacokinetics, therapeutic eVects and toxicity compared favourably with the aqueous drug (in Japanese) Various wines were microwave digested with HNO3-H2O2 or dry ashed then analysed using ETAAS. At 265.9 nm the LOD was 100 pg Blood was digested with HNO and the residue dissolved in H2O. HCl and a 3 solution with Triton X-100 and Tl internal standard were added. The solution was equivalent to a ten-fold dilution of the original specimen. Urine samples were similarly digested, redissolved in HNO3 and diluted to the original sample See Pd, ref 70.Normal levels were 0.48-7.7 ng l-1 and the LOD was 0.24 ng l-1 volume with H2O. Au was added as internal standard 69 70 508 See Pd, ref. 69 Uptake of Pt into cervical and endometrial cancer tissue was determined. Specimens were removed at surgery, one hour after i.v. administration of cisplatin Pt atoms were excited by radiation from a high repetition rate copper vapour 128 509 271 diVerent media was investigated.Pt leaked into lipid-rich tissues at a rate of 20-25 mg d-1 per 250 g implant A programme for the EGS4 Monte-Carlo system was prepared for in vivo 95 74 estimation of Pt uptake. The minimum detectable concentration was 50 ppm Analytes were preconcentrated by a chemical separation step. High purity reagents were used to limit potential interferences. The LOD was reported to be 0.0001 fg ml-1 The Pu isotopes were precipitated and the organic matrix destroyed by wet 284 404 ashing. After ion exchange chromatography a microconcentric nebulizer was used for sample introduction The daily Rb intake in Belgium was evaluated by duplicate portion sampling.The mean intake was 2.2±0.3 mg d-1 Specimens were digested in acid and the REEs preconcentrated using chelating 510 74 62, 63 resin See Pu, ref. 74 Lanthanides were measured. Samples were prepared by microwave digestion, or injected as slurries or solutions.H2O2 was included in the diluent to prevent build-up of ash while trifluoromethane lowered the vaporization temperature Distribution of Rh, following i.p. administration of rhodium propionate to mice, 511 was investigated See Pd, ref. 69 See P, ref. 361 3)2-Mg(NO3)2 was used as chemical modifier. The LOD was 2.3 mg l-1 69 361 168 168 Pd(NO Sb was determined using an STPF in a Zeeman-eVect ETAA spectrometer.The chemical modifier was Pd(NO3)2-Mg(NO3)2-HNO3. An LOD of 2.6 mg l-1 311 HPLC-HGAAS. A miniaturized column, 2 cm×0.4 mm id, was used in conjunction with 50 mM tartrate mobile phase. The LODs were deemed not sensitive enough for measuring real samples 310 SbIII was extracted into hexane after complexing with pyrrolidinedithiocarbamate, then derivatized to triphenylstibine using phenylmagnesium bromide and measured using capillary GC-AAS 763 J. Anal.At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Body fluids, tissues Sb Sb Biological specimens Blood, hair Sb Tissues Body fluids Tissues, fluids Serum Sb Se Se Se Se Blood, plasma, urine, hair Beverages Se Se Marine tissue SRMs Serum Se Serum Se Serum Se Serum Se Serum Se Plasma Se Blood, tissues Se Nutrition liquids Se Edible mushrooms Se Foods Se Human milk Se Human milk Se Biological CRMs Se Se Se Potable water Food supplements, urine Amino acids Se Cod Se Se Foods, plasma, urine 764 J.Anal. At. Spectrom., 1999, 14, 717-781 MS;ICP;L Body fluids were diluted 1+14 with H2O. Tissues were digested with HNO3, either with microwave heating or in open quartz vessels. In was added as internal standard. Accurate results were achieved with various CRMs. LODs were 0.01 mg l-1 and 0.7-0.8 ng g-1 MS;ICP;HPLC Methods to separate at least four Sb species were developed AF;Hy;L XRF;-;S -;-;- -;-;- ;-;- AA;-;- AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L AA;Hy;L NAA; -;- AA;Hy;L AA;Hy;L AA;Hy;L 1.15 and 10.4 ng ml-1, respectively Se content of human milk from 20 volunteers and Se intake of breast fed infants was determined at 1, 2 and 3 months postpartum.There was a slight decline as lactation advanced AE;ICP;HPLC Anion exchange HPLC-ICP-AES was used to speciate selenomethionine, SeIV, AF;Hy;L MS;-;L MS;ICP;L MS;ICP;L MS;ICP;HG 512 169 170 Samples for analysis were prepared by microwave digestion.The LODs were 3 ng g-1 (hair) and 1 ng g-1 (blood) 458 257 513 133 See Ba, ref. 458 A review of the clinical importance of Se species was presented A review of procedures for the determination of Se species RMs containing added inorganic Se were prepared for use as control specimens in speciation studies Specimens from children with phenylketonuria, aged 4.5-15 y, were analysed 514 515 (in German) Sample-Triton X-100, 1+1, was loaded into the autosampler and Pd(NO3)2 added. 20 ml aliquots were injected into the furnace. At 196 nm the LOD was 8 ngml-1 (in Chinese) Sample, <0.1 g, and HNO 28 3, were placed into 7 ml digestion vessels placed inside larger vessels and microwave digested. Total and Se species gave quantitative 516 recoveries, particularly if a multistage microwave programme was used Normal serum Se concentrations of subjects living in Barcelona were established.The range of results, 60-106 mg l-1, indicated adequate Se intake Wall, platform and probe atomization techniques were compared together with 247 an investigation of various chemical modifiers. Platform atomization was recommended. Cu or Pd, alone or with Mg, gave good results and allowed aqueous calibration. The LOD was 10 mg l-1 0.1 M HNO was added to serum, to a pH of 1.5, and left for 24 h to inactivate 7 3 517 2 249 potentially hazardous viruses A standard additions calibration procedure was used with addition of Cu or Pd chemical modifier.Accurate results were demonstrated using D background correction 200 ml sample was added to 800 ml diluent, 0.2% HNO3 in 0.5% Triton X-100. 266 The solutions were mixed ultrasonically using a slurry sampling system Patients with colorectal adenoma had lower plasma Se concentrations than controls.A protective eVect of Se was proposed A new Se agent, selol, was administered to rats. The tissue distribution and 518 519 pharmacokinetics were determined SeIV was measured using HG interfaced to an ETAA spectrometer. The hydrides were trapped in a Pd-coated graphite cuvette at 700 °C. SeVI was determined following reduction. Total Se was measured following sample dissolution with 520 A survey of 12 species revealed very high levels, up to 367 mg kg-1 dry weight, K2S2O8 in a boiling water bath.The LOD was 36 pg Se in one species from Italy and a related species from the Pacific Northwest 521 522 USA. Toxicological consequences were discussed Se was determined in >100 samples of convenience and vegetarian foods. Mushrooms, fish, oVal and some chicken dishes contained the highest levels 3-H2O2, Human milk, 2 ml, or blood, 0.5 ml, was digested with HNO 1.5+0.23 ml, in a microwave oven.The resulting solution was heated at 140 °C for 2-3 h to reduce the volume to 1 ml. HCl, 2 ml, was then added, the volume adjusted to 10 ml and the solution heated at 100 °C for 10 min. Se was measured using FI-HGAAS at 196 nm. The LODs for milk and blood were 523 359 447 357 SeVI, selenocystine and trimethylselonium. 3 diVerent microcolumns were evaluated and a DIN utilized with the ICP-AE spectrometer. LODs were in the range 20-38 ng ml-1 See As, ref. 447 9 organic Se species were separated by HPLC-ES-MS, using either a C18 or a cyanopropyl bonded column. The LODs were sub ng g-1 255 An on-line procedure using sodium tetraethylborate was used to obtain the ethyl derivatives of selenocysteine and selenomethionine. These were then trapped to preconcentrate the species before being eluted into an ICP-mass spectrometer. It was possible to determine the species at ppt levels in selenoamino acids from enzymatic systems 80Se was measured by GC-MS following derivatization using phenylenediamine 354 355 to overcome problems encountered with isobaric interferences in ICP-MS.However when the 2 methods were compared for total Se recovery it was found GC-MS only gave 62-64% whilst ICP-MS gave 100% Volunteers were fed diVerent levels of Se and exchangeable body pool sizes investigated. Plasma and urine were analysed using HG-ICP-MS. Volunteers were also fed cod or yeast enriched with 82Se.The results indicated diVerent metabolic pathways for diVerent speciesTable 1 (Continued) Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Se Si Si Si Si Nutritional supplements, plants Drinking water Foods Infant formula Plasma Blood, plasma Plasma, blood Plasma, serum Serum Serum, breast milk Serum proteins Serum Grain, human hair Pork spare ribs, vegetables Urine Urine Urine Urine Biological specimens Biological specimens Medicines Biological specimens Blood, urine, tissues Urine Biological specimens Serum, tissue Urine, blood Urine Hair MS;ICP;HPLC 10 selenoamino acids were separated using ion pair HPLC-ICP-MS, including the cis-trans isomers of Se-propen-1-yl-DL-selenocysteine. Quantitative results were obtained for enriched yeast and vegetables See As, ref. 317 Cation and anion exchange HPLC-ICP-MS were used to speciate Se in enriched MS;ICP;L MS;ICP;L MS;-;L MS;ICP;L MS;ICP;L of 49±11.55 mg l-1 0.5 ml plasma was heated in 2 ml HNO standard was added and the Se determined. Se concentrations of Sikhs living in Australia were measured MS;ICP;HPLC Selenite enriched with a stable Se isotope was injected into rats and the MS;ICP;L MS;ICP;L MS;ICP;ETV MS;ICP;L MS;ICP;LC MS;MIP;HG XRF;-;S AF;Hy;L NAA;-;S XRF;-;S AA;ETA;HG AA;ETA; FI-HG solution was taken for FI-HG with trapping of H2Se in a graphite furnace coated with In MS;ICP;HPLC A number of columns and conditions were explored and at least seven Se species MS;ICP;ETV AA;ETA;S AA;ETA;IC AA;ETA;L Samples contained 150-250 ppb Se MS;ICP;HPLC Microwave heating with HNO was used for measurement of total Se.Standard additions calibration was necessary to allow for variable final acid concentration.Various extraction procedures were used prior to separation of Se AF;Hy;L AF;-; HPLC MS;ICP;HPLC AE;MIP;GC AA;ETA;L AA;ETA;L AA;ETA;L SIMS;-;S 358 317 356 yeast. Acid or enzymic hydrolysis was required to recover the Se, with solvent based extraction giving recoveries of less than 20%. ES-MS was used to elucidate information about the structure of the species Analysis of 24 commercial brands using HG-ICP-MS revealed mean Se levels 365 265 3 at 100 °C for 1 h.An In internal 261 251 253 subsequent metabolism and incorporation into proteins was monitored A 1+15 dilution with 1% butanol eVectively eliminated polyatomic interferences. Accurate results were obtained with RMs A 1+10 dilution with 0.5% butanol allowed interference-free measurement of 82Se with an LOD of 0.05 mg l-1. Se concentrations in at least four separated 256 2 species were measured Se was separated from sources of interference by ETV and by addition of N 3 to the ICP 260 and CHF Capillary zone electrophoresis and isoelectric focusing were applied to the separation of selenium species Selenoprotein P, glutathione peroxidase and albumin were separated by aYnity 252 254 524 chromatography and the distribution of Se among these proteins determined in two RMs Following addition of 78Se internal standard and digestion with acids, the hydride was formed for introduction into an N2-MIP Water, soil, grain and human hair were analysed as part of a study of Se balance in China and Sri Lanka.The hair and grain samples demonstrated a systematic bias for the HGAFS results when compared to the other 2 techniques Sample was digested in a closed vessel overnight using HNO 353 2O, boiled for 3-H2SO4 and then heated to 60 °C for 4 h. The digest was diluted to 50 ml with H 1 h, filtered and 1 ml CuSO4, 40mg Te and 15 ml SnCl2-hydroxylamine hydrochloride added.The precipitate was filtered oV, dried and taken for analysis by XRF. The LOD was 0.2 mg (in Chinese) Focused microwave digestion was included in an on-line FI system. Not all 504 250 1 ml urine was heated with HBr and KBrO3 at 150 °C for 2 h. Excess Br- was species were converted to SeIV removed by addition of hydroxylammonium chloride and 10% HCl. The 258 64 11 were separated See As, ref. 64 0.1-1.0 mg powdered sample and 10 ml Pd modifier solution were placed into a graphite cup.Alternatively, to increase sensitivity, 0.2-0.4 g and 5 ml modifier were dried and heated at 600 oC for 30 min; the ash was then taken into the graphite cup. The ashing achieved a 10-40 fold preconcentration with an 262 LOD of 10 ng g-1 Se speciation was accomplished by IC using a microbore anion exchange column. The flow rate was 80 ml min-1 and 20 ml fractions were collected automatically into cups on an autosampler.These solutions were injected, together with Pd-Mg(NO 525 3)2 which stabilized all Se species Ni(NO3)2, 100 mg Ni, modifier was used in a comparison of ETAAS and ASV. 526 3 species. Extracts were further treated with a tertiary amine, CFA-C See As, ref. 454 454 See As, ref. 452 452 259 270 Volatile organoselenium species were separated by capillary GC with MIPAES detection Serum or digested breast tissue were diluted with a modifier containing lanthanum 2, NH4H2PO4, EDTA, C2H5COOH, and Triton X-100 268 oxide, CaCl Samples were diluted; urine 1+350 in H 10 ml were injected with 10 ml Ni, 0.5 mg ml-1 in 2% HCl. Recoveries were 2O, blood 1+19 in 1% Triton X-100.less than 90% and LODs were 0.07 mg l-1 and 0.7 mg l-1 for urine and blood, 269 2O were injected into the atomizer with Ni chemical respectively Samples diluted 1+500 in H modifier. The LOD was 0.7 mg l-1 See Al, ref. 436 436 765 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Sn Biological specimens Brain Sn Sn Sn Mussels, sea urchin eggs Biological materials Hatchery fish Sn Sn Drinking water, urine and citrus leaf RMs Fish tissue RMs Sn Fruit Sn Sr Tooth enamel, dentine Foods Sr Hair Sr Bone Sr Urine Th Urine Th Beverages, foods Ti Plasma Ti Urine Tl Urine Urine UU Urine Bone UU Urine VVW Biological fluids and tissues Blood, urine, nails, hair Clinical specimens Chicken organs Zn Zn and tissues Foods Zn Zn Zn Green vegetables Serum, spleen, thymus Plasma, urine Foods Zn Zn Serum Zn 766 J.Anal. At. Spectrom., 1999, 14, 717-781 -;-;- AA;Hy;GC AE;-;L MS;ICP;L MS;-;L MS;ICP;L MS;ICP;L MS;ICP;L AA;-;- AA;F;L AA;F;L MS;ICP;L MS;ICP;L MS;ICP;L AE;ICP;L AE;ICP;L AA;ETA;L AA;ETA;L AA;ETA;L MS;ICP;L MS;ICP;L XRF;-;S MS;ICP;L MS;ICP;L AE;ICP;L -;-;- AA;-;- AA;-;- AA;-;- AA;-;- AA;-;L AA;ETA;L AA;F;L AA;ETA;L A review of the eVects of organotins and their measurement (in Japanese) 154 281 Trimethyltin was determined using a system involving HG, cryogenic trapping, GC separation and detection by AAS.Organotins could be measured when 155 TBT and triphenyltin were determined at LODs of 2-10 and 20-40 ng g-1 using the total Sn taken was as little as 0.2 ng GC-AES and GC-FPD, respectively 100 mg samples were digested with HNO 280 3 (in Japanese) 308 Samples were hydrolysed using KOH-C2H5OH, then TBT and triphenyltin extracted using petroleum ether.The ether was evaporated and the residual extract mixed with 50% ethanol and placed in a solid phase extraction cartridge. The column was washed with 10% methanol and the species eluted using HCl-CH3OH, 1+9. The species were then extracted from the eluate using hexane-cyclohexane, 1+1, hydrogenated and analysed using GC-MS (in Japanese) See As, ref. 448 448 309 402 An HPLC separation of TBT, DBT, di- and triphenyltin, compatible with both ICP-MS and atmospheric pressure ionization-MS, was developed. The latter technique conferred the benefit of providing molecular ion information ICP-MS was used as an initial screen of fruit samples for Sn levels in excess of 0.06 mg kg-1. Samples containing above this level were re-analysed using GC-MS to identify the presence of the pesticide cyhexatin.Using ICP-MS saved a considerable amount of staV time and it was proposed other organometallic pesticides could be screened in this way Sr concentrations were related to tooth type and to stage of caries 277 527 3 Samples were dry ashed at 600 °C, dissolved in 20 ml 5% HNO containing 0.2% KCl and 1% La(NO 278 3 2O2 was mixed with an emulsifier for FAAS. 3)3 and analysed using FAAS at 460.7 nm (in Chinese) Hair digested with HNO and H Sensitivity was improved 55% by addition of the emulsifier (in Chinese) 82 87Sr586Sr ratios were measured by high resolution ICP-MS.Operating parameters were experimentally optimized and corrections for dead time and mass bias were made to achieve a precision of less than 0.03%. Remains from 7000 year old skeletons were investigated HNO and HCl were added with Ir internal standard. Samples from workers 73 3 72 3 371 45 For AES the sample was diluted 1+99 with H with occupational exposure and from controls were analysed Urine was evaporated to dryness at 70-80 °C and the residue dissolved in 1% HNO for determination of Th and U.The LODs were 0.26 and 0.01 mg l-1, respectively Ti was determined in a wide range of foods from Germany in 1988 and 1992. There was evidence of Ti accumulation in some vegetables (in German) 2O. Complex heating programmes 279 3)2 were added as chemical modifiers to were required and memory eVects were noted for the ETAAS methods Tetraamine, Pd nitrate and Mg(NO untreated urine in a procedure to analyse specimens from subjects with 73 283 72 100 occupational exposure to Tl See Th, ref. 73 Dilution of specimens 1+19 in 1% HNO with an Ir internal standard allowed an LOD of 0.32 ng l 3 -1. The mean concentration in non-exposed subjects was 16.1 ng l-1 See Th, ref. 72 Plaster of Paris phantoms with U concentrations of 0-100 mg g-1 were used for calibration.The LOD of 20 mg g-1 was inadequate for occupational monitor- 52 Interference from ClO+ was overcome by cryogenic desolvation to remove Cl- ing by in vivo measurement as condensed HCl. Sc was added as the internal standard See Cr, ref. 51 51 46 Hair and nails were heated at 60 °C for 12 h with HNO3. High concentrations were found in specimens from a subject with suspected poisoning Techniques to detect Zn deficiency were discussed See Ni, ref. 496 528 496 529 11 German test populations totalling 80 men and 80 women were evaluated with respect to Zn intake. InsuYcient dietary intake was observed for 12% of women and 8% of men (in German) See Cu, ref. 476 Concentration changes, associated with aging in rats, were demonstrated 476 530 See Cd, ref. 467 Samples, 100-200 mg, were digested with 30% HNO 467 531 3, 2 ml, for 10 min. The solution was then diluted to 10 ml. Alternatively 20 g of sample was subjected 205 to a 2-stage enzymatic digestion There was no correlation between serum concentrations and dietary intakes of Zn in elderly Spanish institutionalized subjectsTable 1 (Continued) Cows milk Foods Zn Zn Zn Infant formula, infant food Urine Semen Plasma, urine Zn Zn Zn Zn Amniotic fluid Red cells Zn Pharmaceuticals Zn Zn Zn Various Snake and bee venom Cancer tissue Biological and clinical samples, beverages, foods Various Various Various Clinical specimens Clinical samples Clinical fluids, tissues Potatoes Serum, liver Various (16) Various Plasma Herbs, spices Wheat Various (11) Various (8) Various (13) Brown Trout Various (4) Chinese teas Diabetic diets Various (12) Various Hazelnuts Various (9) Nuts, edible seeds Various (4) Olives Various (6) Orange juice Various Spinach Various (8) Various (5) Various Biological samples, foods, waters Milk, infant formula (4) Olive oil Various (8) Serum Various (4) AA;F;L AA;F, air-C2H2;L AA;F;L AA;ETA;L AA;F;L MS;-;L See Cr, ref. 472 AA;F;L See Cr, ref. 473 MS;ICP;L See Cu, ref. 56 MS;ICP;HPLC See Cu, ref. 478 Equal volumes of sample and HNO were taken to 185 °C and 185 psi. The AA;F;L AE;DCP;L XRF;-;S XRF;-;S -;-;- -;-;- -;-;- -;-;- -;-;- -;-;- -;-;- AA;-:- AA;-;- AA;-;L AA;-;L AA;-;L AA;-;L AA;-;L AA;-;L AA;-;L AA;-;L AA;ETA;L AA;ETA;L AA;ETA;L AA;ETA;L 318 532 See Fe, ref. 318 Dietary intake in Egyptian urban populations was determined. Phytate was also determined in order to assess impact on Zn bioavailability See Al, ref. 370 370 472 473 56 478 202 3 solution was evaporated to dryness and dissolved in 6 M HCl. Further purification by extraction with diisopropyl ether and ion exchange chromatography was undertaken See Cd, ref. 143 143 207 Determination of the Zn concentration was one of various investigations used to identify suspicious solutions See Cu, ref. 200 The 1997 ASU 200 5335 1291 A review of recent developments for trace element analysis This review examines protocols to achieve high quality results An introduction to procedures for sample preparation, speciation and measurement of trace elements in clinical specimens A neural network, incorporating a database containing 1000 samples was used 5344 to determine geographic origin Methods for sample preparation and analysis were described.Interferences in ICP-MS were listed and applications of coupled techniques were given (in German) A summary of interlaboratory surveys with comparisons of analytical techniques 130 535 536 (Ca, Cu, Fe, K, Mg, Na, P, Pb, Se, Sr, Zn) (in Japanese) Levels of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn in samples imported into Poland were measured. Concentrations were found to be permissible (in Polish) Elemental profiles were used to assess species, origin and variety of wheat following analysis by both ion chromatography and AAS Ni pollution from a disused Norwegian smelter and mine was investigated by 160 determining Co, Cu, Ni and Zn in fish samples.Although the levels found were concluded not to pose a threat to human health, severe physiological aVects were reported in the fish collected from one of the sampling sites The eVect of diVerent production processes on elemental levels was investigated 537 410 538 The trace element profile of diabetic meals served in a Japanese hospital were evaluated.Low energy meals, 1200 kcal, were found to contain Cu, Fe, Mg, and Zn levels below recommended daily intakes (in Japanese) A range of nutritional parameters in 6 varieties of Tarragona hazelnuts were measured.Of the elements determined, only K showed significant variation 539 between varieties (Ca, Cr, Cu, Fe, K, Mg, Mn, Na, Zn) A survey of a wide range of samples-peanuts, pistachios, almonds, hazelnuts, etc.-found Cd, Cu and Zn in blue poppy and sunflower seeds and Zn in pumpkin seeds to exceed permissible levels. Pb was acceptable in all samples (in Polish) The content of Co, Cr, Cu, Fe, Mn, Ni and Zn were determined in 5 olive 540 541 varieties at diVerent stages of ripening. The metals were selected as they are believed to be catalysts in the oxidation of olive oil The combination of Ba, Rb, K and isotopic data allowed the geographical origin of samples from Brazil, Florida and Israel to be correctly assigned A Spanish group reported on the levels of Ca, Cu, Fe, K, Mg, Mn, Na and Zn in spinach.The 2 papers reported on commercial and then experimental 365, 366 samples. Over a 4-month period of storage the authors reported that both sample sets showed some evidence of increases towards the end of this time for some elements (in Spanish) An Ir-coated tube was used to trap and enrich hydrides of As, Bi, Hg, Sb and 350 Se, yielding LODs in the range 0.03-0.08 mg l-1 (in German) Powdered samples were suspended in a medium containing 1% HNO 326 3-20% ethanol and varying levels of H2O2.Liquid samples were diluted with the suspension medium. The resulting solution was introduced in the ETAA 325 spectrometer and measurement conducted against aqueous standards, containing 2% lactoalbumin in the case of Mo (Al, Cr, Mn, Mo) Samples were dissolved in 1,4-dioxane with the addition of N,N-hexamethylenedithiocarbamic acid hexamethyleammonium salt as a universal modifier for Al, Cd, Cr, Cu, Fe, Mn, Ni and Pb.Aqueous standards could be used for 111 calibration Reference ranges for healthy children at diVerent ages were established (Cu, Mn, Se, Zn) (in German) 767 J.Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Sparkling wine Various (6) Waters Various (28) Beer Various (4) Clams, mussels Various (10) Confectionery Various (8) Dairy products Various (4) Mango juice Various (6) Mineral water Mussel CRM Various (4) Various (16) Papaya Various (8) Sugars Various (4) Teas Various (9) Vegetables Waters, salt Various (11) Various (12) Wine Various Wine vinegar's Various (9) Various (7) Human hair CRM, Dogfish liver and muscle CRMs Foods Various Beverages, foods Various Cactus juice CoVee Various (27) Various (11) Various (4) Dog fish muscle and lobster SRMs Herbal medicines Various (16) 768 J.Anal. At. Spectrom., 1999, 14, 717-781 AA;ETA;L AA;F, air-C2H2;L AA;CV;L AA;ETA;L AE;ICP;L AA;F;L AE;F;L AA;F, air-C2H2;L AA;CV;L AA;ETA;L AA;F, air-C2H2;L AA;F;L AA;F, air-C2H2;L AA;F, air-C2H2;L AA;F, air-C2H2;L AA;ETA;L MS;ICP;L NAA;-;- AA;F;L AA;F, air-C2H2;L AA;Hy;L AA;F;L AA;F;L AA;F, air-C2H2;L AA;F, air-C2H2;L AE;F;L AA;F, air-C2H2;L AE;F;L AA;Hy;L AA;F, air-C2H2;Sl AE;glow discharge;S,L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L 377 296 To avoid losses associated with eVervescence when de-gassing sparkling wines a method based on ultrasonic agitation was developed.The method gave comparable results to and oVered practical advantages over reference methods (Cd, Cu, Fe, Hg, Pb, Zn) A wide range of elements were determined in high purity and drinking waters following preconcentration by distillation, using a vacuum apparatus constructed from high purity silica and co-precipitation with 8,8¾ diquinyldisulfide. A round robin procedure was used to validate the method 381 A dual manifold FI system for simultaneous determination of Ca, Mg (by performed on-line dilution and addition of La3+, greatly reducing the con- FAAS), K and Na (by flame photometry) was developed.The system 542 sumption of this reagent Pollution in the Po river, Italy, was assessed by measuring Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb and Zn in local shellfish samples 543 544 Cu, Fe, Mg, Mn and Zn were determined directly on aqueous solutions of the sample, Cd, Pb and Ni following chelation and extraction using APDC-IBMK (in Polish) A closed vessel microwave method for determining Ca, K, Mg and Na in cheeses, caseinates and skimmed milk was described.Standard additions 545 calibration was required to achieve optimum accuracy 10 ml juice+5 ml HNO was heated to 105 °C for 45 min. Following filtration 3 the samples were diluted to 25 ml with H2O and Ca, Cr, Fe, K, Na and Zn determined at 422.7, 357.9, 248.3, 766.5, 589 and 213.8 nm, respectively.The 546 procedure was also proposed for the analysis of urine and milk Measurements were made at 589, 766.5, 422.7 and 285.2 nm for Na, K, Ca and Mg, respectively Samples were sonicated for 120 min in a solution of 1.6 M HNO 288 3-12 M HCl-0.1 M H2O2. FAAS or ETAAS was used to determine elements leached into the solution. Results were confirmed using ICP-MS and NAA. Quantitative leaching was obtained for 9 elements 368 Levels of K, Mg, Mn and Zn were found to be aVected by variations in freezing process and storage conditions.Na levels were not in agreement with those reported by other authors (Ca, Cu, Fe, K, Mg, Mn, Na, Zn) (in Spanish) Sample preparation procedures for determining As, Cu, Fe and Pb were described 290 289 Infusions were prepared and treated using UV decomposition in the presence of H2O2. Decomposition was necessary to remove tannic acid which gave elevated 409 321 levels for Fe and Mn (Al, Ca, Cu, Fe, K, Mg, Mn, Na, Zn) Elemental concentrations in 20 species of vegetable from Bangladesh were determined (Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Zn) Samples were diluted in 1% HCl, then injected into an FI-FAAS system incorporating a STAT. The signal enhancement over conventional FAAS was 417 1.2-3.3-fold (in Chinese) The geographical origin of 31 wines from Argentina, Brazil and Uruguay was correctly assigned using elemental data and PCA 419 Forty wine vinegars from Southern Spain were analysed for their As, Ca, Cu, Fe, K, Mn, Na and Zn content.Pattern recognition allowed quick and slow processed vinegar's to be distinguished 547 Hair was cleaned and powdered in a zirconia mill. Portions, 0.1 g, were dispersed in H2O and diluted to 25 ml. Samples, 0.25 or 0.5 ml, were treated with HNO3 to give a concentration of 1% and the slurry diluted to 5 or 10 ml. The solution was stirred ultrasonically prior to aspiration into the FAA spectrometer (Ca, Cu, Fe, K, Mg, Na, Zn) Four sample introduction procedures were evaluated: glow discharge itself, direct 548 insertion, electrothermal vaporization, and electrospray.Direct insertion was good for some elements, but precision was poor. The other techniques oVered better precision, but were more time consuming as sample preparation was required A method was described for confirming compliance with the US Nutrition Labelling Act (1990).Sample dissolution was achieved using microwave 549, 550 551 420 digestion Variation in juice trace element and pigment content at diVerent stages of ripening was measured (in Chinese) 41 samples of green coVee belonging to the varieties arabica and robusta were analysed by ICP-AES and the samples characterized using PCA and cluster analysis (Ba, Ca, Cu, Fe, K, Mg, Mn, Na, P, Sr, Zn) As, Cd, Pb and Se were determined following on-line preconcentration 552 350 Sixteen elements were determined at LODs in the range 0.1-5 ng ml-1 following wet acid digestion using HNO and H2O2 (in Chinese) 3Table 1 (Continued) Various Human breast milk, infant formula Milk powder SRMs Various (11) Various Milk powder SRMs Multivitamin Various tablets Saline solutions, Food CRMs Various (18) Serum, red cells Wine Various (5) Various (15) Wine Various (25) Wheat Various (8) Biological CRMs Various (11) Various Biological materials, foods Various Drinking water, calcium supplements, milk Food SRMs Various (13) Various Foods, wine, neuroblastoma cells Various Various Herbal medicinal teas Human hair and wheat flour RMs Milks Various (11) Mussel SRM Various (9) Various Plant derived foods Rice Various (REE) Rice flour RM Various (4) AE;ICP;L MS;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;ICP;L AE;laser;S MS;ICP;L,Sl MS;ICP;L AE;ICP;L MS;ICP;L MS;-;L AE;F;L MS;ICP;L MS;ICP;L MS;ICP;L,Sl AE;ICP;L,Sl MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L NAA; -;- MS;ICP;L 38 The paper reported studies to investigate the binding pattern of trace elements in formulas compared with breast milk and the relationship between trace elements in breast milk and in maternal dietary intake.SEC-ICP-AES or SEC-ICP-Ms was used to speciate elements of nutritional significance.Considerable diVerences in binding forms of elements, e.g., Fe, were found in the 2 fluids 553 Aqueous solutions were prepared containing Sc as internal standard and analysed directly using an axially viewed ICP-AE spectrometer. Addition of Cs as ionization buVer was necessary (Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr, Zn) An almost identical presentation to ref. 553 was given 554 147 3 Samples were digested using HNO -HCl, 1+1.Subsequent analysis by an open vessel procedure gave levels 40% below label claims.Use of microwave digestion gave results in compliance with the label 36 An axial spectrometer equipped with a microconcentric nebulizer was compared with a concentric glass nebulizer. The analytical performance of the latter was generally better, although the scale was element dependent. Increased salt concentration aVected the stability and sensitivity of the MCN to a greater extent 40 418 Trace elements and enzymes were measured in blood of healthy infants at intervals from birth to four months of age (Ca, Cu, Mg, P, S) (in German) 17 wines from 6 regions were analysed by ICP-AES and the data interrogated using an artificial neural network. Perfect classification was achieved, better than other multivariate procedures such as PCA, Fischer discrimination and Bayes discrimination 555 Wine, must and lees were digested using HCl-HNO3, 4+1, in a microwave oven.The role of the elements determined in vine growth and wine character was discussed (in French) 556 A novel spectrometer was described. A 5 ns pulse from a Nd5YAG laser was focused onto the sample and the resulting radiation carried via an optical fibre to an e�chelle spectrometer fitted with a CCD camera. It was claimed that 60 elements could be determined simultaneously with LODs of a few mg kg-1 over the spectral range 180-750 nm (Al, Ca, Fe, K, Mg, Mn, P, Si) (in German) 17 Sample, 20-100 mg, was mixed with 25% m/v TMAH, 10-200 ml.Complete dissolution was achieved for animal tissues, slurries obtained from other samples. Electrothermal vaporization was used for sample introduction. Cr and Cd could not be determined in bovine muscle due to spectral interference and matrix eVects, respectively 19 This conference paper described numerous benefits of employing tertiary amine mixtures in dissolution media, e.g.: 1, neutralizing HF, thus preventing attack on the Si containing parts of the ICP and allowing low level determination of Si; 2, signal enhancement for As and Se, applied in the determination of these elements in diets and breast milk; 3, avoiding acid dissolution in the determination of I 304 68 316, 557 Negative-ion ESMS was used to determine metal cations as EDTA complexes.It was possible to differentiate between common valence states of Fe and V. Oxide interference in determination of REEs was overcome HR-ICP-MS was used following HNO3 dissolution in a microwave oven. Generally good results were obtained, although problems of incomplete dissolution, detector saturation and high background were reported The application of ICP-MS coupled to reversed phase or SEC-HPLC was discussed in 2 conference presentations. One application was the study of tolerance of neuroblastoma cells to Al, with 2 Al-containing low MW species identified, one of which increased in concentration when cultures were exposed to Al. Other applications included the binding of metals by wine proteins and polysaccharides and the speciation of glycoprotein-bound Se in immunologically active plants 286 140Three preparation techniques were compared-slurry nebulization, microwave digestion and simple infusion The merits of dry ashing, microwave and open vessel acid digestion for the 0.0003-0.0039 ng cm-3and RSD <10% for most elements determination of REE was discussed. The LODs were in the range 411 332 The concentration of Al, Ba, Cd, Cr, Cu, Mg, Mo, Ni, Pb, Sn and Zn were determined in cows' milk based formula, breast, soya, dried, bottled and evaporated milk. Except for Ni in the soya milk, levels were close to recommended values The performance of Q-ICP-MS and HR-ICP-MS was compared for the determination of As, Cd, Cr, Cu, Hg, Ni, Pb, Se and Sn following dissolution of the 3-H2O2 in a microwave oven.Perhaps unsurprisingly, those 558 sample using HNO elements traditionally suVering from polyatomic interferences gave more accurate and precise data using the high-resolution instrument Samples were microwave digested using H2O-HNO3, 1+3, and a stepped 364 heating programme. The detection limits were <2.2 pg g-1 REE were determined following sequential microwave digestion using HNO3, H2O2 and then HF 559 Samples were digested in a microwave oven and analysed using ID-ICP-MS (Cd, Cu, Pb, Zn) 769 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Serum, bone Various Serum, urine Various Tea Various (28) Teas Various (REE) Water Various Wine Various (33) Wine Various Brain, vegetables Various Various Vegetables, Chinese tea Blood Urine, blood Various (5) Various Blood Various (5) Blood cells Blood, serum Various (4) Various (5) Urine, serum Various Urine Various (5) Urine, blood Various (6) Urine Various (9) Urine Various Urine Serum Various (4) Various (4) Serum proteins Various (9) Serum Various (8) Various Serum proteins, DNA Metallothionein Various (4) Various (5) Various (6)Cerebrospinal fluid Cerebrospinal fluid 770 J. Anal. At. Spectrom., 1999, 14, 717-781 MS;ICP;L MS;ICP;L MS;ICP;L AE;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L MS;ICP;L XRF;-;S XRF;-;S, LMS;ICP;L AA;F;L AA;F;ETV AA;F;L AA;ETA;L MS;ICP;L MS;ICP;L AA;F;L AA;ETA;L AA;Hy;L AA;CV;L AA;ETA;L MS;ICP;L MS;ICP;ETV MS;ICP;L -;-;L MS;ICP;LC MS;ICP;LA MS;ICP;LC AA;F;HPLC Isoforms of metallothionein were separated by SEC or ion exchange HPLC and a quartz T-tube interface linked the eluent to the AA detector (Ag, Cd, Cu, Zn) MS;ICP;HPLCA combined ion exchange chromatography and SEC procedure was developed to investigate binding of elements to proteins (Ca, Cu, Fe, Pb, Zn) Specimens from premature infants were analysed (Ca, Cu, Pb, Rb, Sr, Zn) MS;ICP;L 560 75 Concentrations of trace elements in normal and uraemic sera were measured by HR-ICP-MS The high resolution of a sector field mass spectrometer was used to eliminate spectral interferences.Samples were acidified and diluted 20-100-fold and an internal standard added Elemental analysis in conjunction with PCA was able to discriminate between 421, 561, 562 3 331 African and Asian and between Chinese and other Asian teas. A total of 15 teas from 10 countries were analysed following digestion using HNO3, 0.4 ml Sample, 0.2-0.3 g, was weighed into a PTFE insert and 3 ml HNO H2O2, 0.2 ml HClO4 and 0.2 ml HF added.The vessel was capped and the sample digested via a microwave-heating programme. After cooling the inserts were removed, the contents washed into PTFE beakers using 1 ml HNO3, evaporated to near dryness and adjusted to pH 0-0.5 using NaOH. A cation exchange column was then used to separate REE from the matrix, the former being determined using ICP-MS with Re as internal standard 563 416 The molar response curves for both a quadrupole and a sector ICP-mass spectrometer were calculated using a series of internal standard elements. The results were used in conjunction with correction factors for ionization eYciency to improve the accuracy of semi-quantitative analyses 17 white and 13 red wines from 13 wineries in the Okanagan valley, Canada, were analysed. A total of 25 elements correlated strongly with the vineyard of origin.The wine element fingerprints were deemed soil signatures that survived metabolic and winery influences 415 106 FI-ICP-MS was used to analyse 112 wines from Spain and England The region of origin of the Spanish wines was given unequivocally. It was also possible to diVerentiate Spanish and English white wines with 100% accuracy A new XRF spectrometer, capable of spatial mapping at a resolution better than 20 mm, was described. Autopsy samples showing brain calcification and leaves from plants exposed to acid rain and X-ray radiation were among the examples cited (in Japanese) 439 564 Samples were separated into a cytosol and pellet fraction by ultracentrifugation and the binding of metals to high and low molecular weight proteins investigated (in German) 10 ml capillary blood was diluted with 100 ml 0.05%Triton-100 and the full amount aspirated via the nebulizer (Ca, Cu, Fe, Mg, Zn) (in Chinese) 10 ml sample was placed onto a tantalum filament from which ETV into the 125 565 40 ml blood and 1.5 ml 5 g l-1 Triton X-100-5 g l-1 Na flame occurred 2EDTA for measurement of Cu and Zn. The solution was diluted a further five-fold for determination 566 Mg(NO of Ca, Fe and Mg (in Chinese) Cell types were isolated by density centrifugation, digested and analysed with 3)2-Pd-H2O2 as the chemical modifier (Cr, Cu, Se, Zn) 21 An automated preparative system was developed with a microwave digester and an iminodiacetate-based resin column for separation of analytes from the matrix elements. Analysis rate was 6 samples h-1 (Cu, Fe, Ni, Pb, Zn) ICP-MS for measurement of trace elements in clinical specimens was reviewed 49 115 with emphasis on ways to eliminate interferences Specimens from patients with Blackfoot disease were digested for analysis.As, Hg and Pb concentrations were increased, Se and Zn were reduced, compared with normal controls (As, Hg, Pb, Se, Zn) 567 10 Application of a controlled voltage caused electrolytic movement of analytes from the sample into the Pd-coated furnace. Residual sample, which contains the components responsible for interferences, was removed and the furnace heated for atomization (Cd, Co, Cr, Mn, Ni, Pb) A comparison of H2O dilution, UV irradiation and HNO3-H2O2 digestion, prior to measurement by Q-ICP-MS or magnetic sector field ICP-MS, was 568 reported (Cd, Co, Cr, Ni, Pb, Rb, Sb, Se, V) Advantages of ETV, of small sample volume and reduced interferences, were discussed in the context of monitoring occupational exposures After a series of investigations a sample dilution of 1+9 with In as internal 76 569 570 standard gave acceptable results for HR-ICP-MS (Cd, Cu, Pb, Zn) Conditions were optimized for separation of metalloproteins by SEC with element specific detectors. The preferred column material was Asahipak, a vinyl alcohol copolymer (Ca, Fe, Na, Zn) Serum proteins were separated on Mono Q HR 5/5 anion exchange Fast Protein LC, and the associated metals were detected by coupled double focusing 59 ICP-MS (Al, Cr, Cu, Fe, Mn, Se, Sn, Sr, Zn) Proteins were separated by gel electrophoretic techniques and the trace elements detected by LA-ICP-MS (Au, Cd, Cu, Fe, Hg, Pb, Pt, Zn)Binding of metals to proteins and DNA was investigated 571 572 573 574Table 1 (Continued) Ileostomy fluid Various (5) Intestinal fluids Body fluids Various (8) Various (11) Various (42) Hair, blood, red cells Biological tissues Various Bone Bone substitutes Various (58) Various (24) Teeth Teeth Various (4) Various (7) Fetal tissues Various (26) Placental tissues Various Neural tissues Amyloid plaques Lung Various (6) Various (8) Various (8) Liver Various Tissues Various Tissues Various (10) Tissues Various Tissues Various (10) Various Various Various Biological materials Biological specimens Biological materials Various Biological materials Biological materials Various (4) Various Biological specimens Various Various Biological specimens Biological specimens Hair Various Hair Various (4) Hair Hair Various (7) Various (5) Various Pharmaceutical preparations MS;ICP;SEC AE;ICP;L AA;Hy;L AA;ETA;L MS;ICP;L MS;ICP;L MS;ICP;L AA;Hy;L AA;CV;L AE;ICP;L AA;F;L AE;F;L AE;ICP;L MS;ICP;L AA;F;L AA;ETA;L AA;ETA;L AE;ICP;L MS;ICP;L AA;F;L AA;ETA;L the lung were determined and the eVects of smoking, sex and occupational exposure were investigated (Al, Cd, Cr, Cu, Mn, Ni, Pb, Zn) MS;ICP;HPLCProteins from a liver extract were separated and the attached metals determined MS;ICP;L MS;ICP;L MS;ICP;LA AE;ICP;L MS;-;- -;-;- MS;-;- AA;ETA;L AE;ICP;L AA;ETA;Sl MS;ICP; capillary electrophoresis AE;ETA;HG AE;ICP;ETV -;-;- AA;F;L AE;MIP;L AE;ICP;L -;-;- 192 575 Fluid collected from ileostomy patients following ingestion of a meal spiked with 106Cd was centrifuged and the Cd species separated by SEC. ICP-MS was used to measure 106Cd, 111Cd, 63Cu, 57Fe, 206Pb and 66Zn Binding of elements to tea polyphenols was investigated in an in vitro, ultrafiltration study assessing bioavailability (Ca, Cu, Fe, Mg, Mn, K, Na, Zn) 576 577 On-line solid phase extraction and other recent developments were reviewed (Al, As, Co, Cr, Fe, Mn, Mo, Ni, Se, V, Zn) (in German) 0.2 g sample and 3 ml HNO3 were heated at 115 °C for 30 min. Good recovery of volatile elements was observed and large numbers of specimens were readily prepared Equipment and conditions for the microwave digestion of small samples were 578 132 43 discussed Laboratories collaborated in providing data to add to the usefulness of SRM 1400 Bone Ash. See also Pb, ref. 132 Wollastonite (CaSiO3) preparations were heated in acid (conditions were optimized for diVerent analytes and procedures) 27 3 44Powdered tooth material was dispersed in HNO and then pumped through a coiled PTFE tube in a microwave oven (K, Mg, Na, Sr) 2O2 and ashed at 450 oC under O2. The 3 (Al, Cd, Washed teeth were soaked in 5% H residues were powdered and 0.5 g digested in 10 ml 50% v/v HNO Cr, Cu, Fe, Pb, Zn) 53 Samples collected from 21 human fetuses aged 16-22 weeks were digested with acid using microwave heating. Particular attention was given to contamination control and to demonstration of accuracy and precision. Concentrations increased with fetal age and were lower than in adult tissues Dried specimens were microwave digested and analysed to determine normal 113 167 54 values Tissue concentration changes during uterine and infant development were monitored following maternal exposure to Al (Al, Ca, Fe, Mg, Mn, Zn) Amyloid plaques were extracted using an FI system from brain preparations taken from patients with Alzheimer's disease (Al, Cr, Cu, Fe, Mn, Ni, Pb, Zn) Tissues from urban dwellers were analysed. Concentrations in diVerent parts of 114 579 580 3 in 20 ml vessels using by ICP-MS 50-100 mg samples were digested in 700 ml HNO microwave heating. Residues were diluted with H2O to reduce the acid content 581 3 Samples were heated with HNO and then with H2O2. These solutions were diluted and analysed. Procedures to compensate for interferences were 60 29 3 described (As, Ca, Cl, Co, Cr, Hg, Ni, Se, V, Zn) Soft tissues were placed into a special cell into which liquid N2 was added. The laser beam was then focused onto the surface of the frozen, solid specimen A device for vapour phase HNO digestion of 50-100 mg specimens was used and microwave heating was successfully used to achieve decomposition (Al, As, Ca, Cd, Cu, Fe, Mn, Mo, Pb, Zn) Applications of ICP-MS, TIMS and AMS were reviewed 48 582 Methods for decomposition of specimens prior to analysis were reviewed (in Czech) A bibliography of publications involving applications of MS 583 584 Dry ashing and wet digestion methods for sample decomposition were reviewed in detail. Enzyme catalysed and UV photolysis methods were also discussed (in Czech) Dried, powdered specimens were suspended in 5% HNO 14 3.The slurry was analysed using very rapid heating programmes and results were in agreement 585 with expected values Cd, Cu, Mn, Pb Capillary electrophoresis was used to speciate nl volumes of specimen. Interfaces to link the output to the ICP were discussed FANES, with solid phase preconcentration steps and HG, was reviewed 586 A tungsten coil atomizer vaporised samples into the ICP 118 134 137 3 Trace element concentrations in hair were shown to be subject to external influences and not to correlate with blood or tissue content Hair from men with alopecia was digested with HNO -HClO4. Concentrations of Mn and Zn were lower, Cu was increased and Fe was unaltered compared with control samples (in Chinese) Data from samples from Chinese schizophrenic patients were reported (Co, Cu, 587 139 588 Fe, K, Mg, Mn, Na) Acid-assisted microwave digested samples were analysed as part of a study of influences of Antarctic conditions on human health (Ca, Cu, Fe, Mg, Zn) Various atomic spectroscopy techniques suitable for pharmaceutical research were discussed 771 J. Anal. At. Spectrom., 1999, 14, 717-781Table 1 (Continued) Dialysis fluid Various (7) Cocaine, heroin Cannabis Various (4) Various Chinese herbal medicine Various (4) Various Drugs, biological specimens Bone Plasma Tooth enamel Various (12) Various (16) Various (4) Hair Various (8) Tissue slices Various *Hy indicates hydride and S, L, G and Sl signify solid, liquid, gaseous or slurry sample introduction, respectively. Other abbreviations are listed elsewhere. 3 References