JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 87 R ATOMIC SPECTROMETRY UPDATE-CLINICAL AND BIOLOGICAL MATERIALS FOOD AND BEVERAGES Andrew Taylor* Supra-Regional Assay Service Metals Reference Laboratory Robens Institute of Industrial and Environmental Health and Safety University of Surrey Guildford Surrey UK GU2 5XH Simon Branch The Lord Rank Research Centre R. H. M. Research and Engineering Lincoln Road High Wycombe Buckinghamshire UK HP12 3QR Helen M. Crews Ministry of Agriculture Fisheries and Food CSL Food Science Laboratory Norwich Research Park Colney Lane Norwich UK NR4 7UQ David J. Halls Trace Element Unit Institute of Biochemistry Royal Infirmary Castle Street Glasgow UK G4 OSF Mark White Research and Laboratory Services Division Health and Safety Executive Broad Lane Sheffield UK S3 7UQ Summary of Contents 1 Analysis of Clinical and Biological Materials 1.1.1.2. 1.3. 1.4. 1.5. 1.6. 1.7. 1.8. 1.9. General Reviews Sampling and Sample Preparation Developments in Multi-element Analysis 1.3.1. 1.3.2. 1.3.3. X-ray fluorescence spectrometry 1.3.4. 1.3.5. Imaging techniques Developments in Single Element Techniques Reference Materials and Quality Assessment Hair Analysis Marine Biology Drugs and Pharmaceuticals 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. Cadmium 1.9.7. Calcium 1.9.8. Chromium 1.9.9. Cobalt 1.9.1 0. Copper 1.9.1 1. Fluorine 1.9.1 2. Gadolinium 1.9.1 3. Germanium 1.9.14. Gold 1.9.1 5. Iodine 1.9.16. Iron 1.9.1 7. Lithium 1.9.18.Lead 1.9.1 9. Magnesium 1.9.20. Manganese 1.9.21. Mercury 1.9.22. Molybdenum 1.9.23. Nickel 1.9.24. Platinum 1.9.25. Selenium 1.9.26. Silicon 1.9.27. Silver 1.9.28. Strontium 1.9.29. Thallium 1.9.30. Tin Inductively coupled and direct current plasma atomic emission spectrometry Inductively coupled plasma mass spectrometry and other mass spectrometric techniques Other multi-element techniques and studies88 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 2.1. 2.2. 2.3. 2.4. 2.5. 2.6. 2.7. 2.8. 2.9. 1.9.31. Uranides 1.9.32. Vanadium 1.9.33. Zinc Table 1. Summary of Analysis of Clinical and Biological Materials 2 Analysis of Foods and Beverages Sampling and Sample Preparation 2.1.1. Direct determination of analytes 2.1.2. Preconcentration 2.1.3.Digestion 2.1.4. Direct solids and slurry sampling Developments in Vapour Generation Techniques Speciation Studies Developments in Methodology for Electrothermal Atomic Absorption Spectrometry Developments in Methodology for Plasma Atomic Emission Spectrometry Developments in Methodology for Inductively Coupled Plasma Mass Spectrometry Applications of X-Ray Fluorescence spectrometry Single and Multi-element Analysis of Foods Characterization Studies 2.1 0. Reference Materials and Collaborative Trials Table 2. Summary of Analyses of Foods and Beverages We are delighted to welcome a new member to our review group; Mark White has a formidable practical background in occupational medicine and the addition of his experience has been greatly appreciated. The publications and conference reports included in the ninth Atomic Spectrometry Update-Clinical and Biological Materials Foods and Beverages are from abstracts 93C/910 through to 94/61 4 which have been listed in the Journal of Analytical Atomic Spectrometry throughout the last year.In the eighth review (J. Anal. At. Spectrom. 1993 8 79R-136R) we noted the growing use of sample enrichment often accomplished on-line to the measurement technique. This trend continues to be evident in more recent work. Two other activities to which attention can be drawn are methods for the determination of metals in solid materials either in situ to provide ultrastructural information or for multi-element analyses other than with plasma-mass spectrometric techniques and measurements of metal chelates by GC-MS.This latter procedure is not an ‘atomic’ analysis and some thought will have to be given by the Editorial Board as to future inclusion in the journal. For the moment however it is timely to ensure that interested readers are aware of this important development. In the tables the arrangement of entries ‘Element Various’ has been improved. Entries are now grouped by matrix so that similar applications appear together. In Table 1 the groups are Serum plasma and blood; Urine; Other biological fluids; Soft tissues; Bone and other hard tissues; Hair and nails; and Biological materials and RMs. In Table 2 the groups are CRMs; Foods; and Beverages. 1. ANALYSIS OF CLINICAL AND BIOLOGICAL MATERIALS David J. Halls Andrew Taylor and Mark White This review covers recent developments in atomic spectro- metric techniques for the analysis of clinical and biological materials. Table 1 summarizes published and conference papers produced within the review year.1.1. General Reviews According to Tolg (93/2816) in a review entitled ‘The role of trace elements for life from the point of view of an analytical chemist’ the challenge for the analytical chemist in helping to understand the ambivalent nature (i.e. toxic versus essential) of many elements is to develop methods that determine the minimal absolute quantities of trace elements in the most precise and accurate way. Growing concentrations of certain elements such as mercury and platinum (from car catalytic converters) are now found in the biosphere. Tolg saw the most promising methods for the near future as laser spectroscopy TXRF and MS of the elements (e.g.ICP-MS and GDMS). A review by Delves (93/1140) dealt with preparation of clinical samples and foodstuffs for accurate determination by FAAS ETAAS and ICP-MS. Measures to reduce interferences in ETAAS were illustrated by methods developed in the author’s laboratory. A comprehensive review on speciation using chromatography coupIed with ICP-AES and ICP-MS by Hill et ul. (93/3219) covered many applications to clinical and biological samples. 1.2. Sampling and Sample Preparation Increased use of vacutainers for blood collection in hospitals has caused a number of problems for the trace metals analyst. Crick and Flegal (93/2117) found that the special vacutainer tube for trace element studies (B-D 6527) released ten times as much Pb as a tube for general biochemistry (B-D 6488) and that the amount of Pb increased by about 40% over a 7 d period.Plain vacutainer tubes without anticoagulant for trace elements (B-D code not recorded) were reported by Villalba et al. (94/550) to be satisfactory for Pb as well as Cu Co Fe Mn and Zn. However an inspection of the data shows contamination levels which would be a problem in the measure- ment of the low concentrations of Mn Co and Pb present in normal serum. They found that the tubes were unsuitable for Al. In these reviewers’ experience all vacutainers made of glass are unsuitable for sample collection for the determination of some elements including Al and Mn. The research to establish collection and storage procedures for the Italian study on reference values has been published by Minoia et al.(93/4105). Collection of blood through a PTFE cannula was recommended for the determination of Al Ba Cd Co Cr Mn Mo Ni Sb W V and Zn. Anticoagulants contaminated samples for Co Cr and Mn but were satisfactory for Rb Se and Zn. No significant losses of trace elements were found for samples stored at -220°C for 1 month. There has been further development of on-line microwaveJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 1 CLINICAL AND BIOLOGICAL MATERIALS 89 R Tech niq u e; atomization; analyte form* AA;ETA;L ~ Reference 93/C 1063 941227 Element Matrix Ag Plasma Sample treatment/comments An individual who used excessive amounts of a silver-ointment to treat leg ulcers developed symptoms of argyria and had a high plasma Ag concentration Samples were heated with HNO and H202 in closed vessels and then evaporated.The residues were dissolved in 5 ml 1 mol 1-' HNO and diluted to 50 ml with 0.5% NH4SCN. 1 p1 was injected into a molybdenum atomizer and Ar-H (24:l) was used as the purge gas Possible interferences from other elements in serum and dialysis fluids were investigated with tube wall platform and probe atomization. No interferences were found with the probe but platform atomization gave better sensitivity and was recommended. However carbonaceous residues accumulated with serum samples but this was eliminated by an 0 ashing step Sections of brain were digested with HNO in a sealed container.Solutions were diluted with a K,Cr,O ( 1 mg ml- ') solution which was shown to eliminate interference from alkali alkaline-earth metals and P 1 ml was diluted with 4 ml KCI solution for the sequential determination of Al Cu and Zn. The procedure had acceptable sensitivity and linear ranges. Results of the few specimens analysed compared favourably with AAS techniques Serum proteins were separated by size-exclusion chromatography and the Al associated with different fractions was measured. When subjects with high concentrations of A1 in the serum were given desferrioxamine the distribution among proteins was altered with a greater proportion in an albindin fraction Techniques were reviewed for the measurement of A1 in clinical samples together with approaches to quality assurance.ETAAS was covered in depth and the current standards of proficiency were described Specimens from subjects with exposure to Al welding fumes had high concentrations which persisted for several years after cessation of the exposure Factors such as ageing were seen to affect the concentration of A1 and F in hair (in Japanese) Different procedures were examined and best results were obtained when the sample was diluted with 0.1 mol 1- HNO and Mg(N03)2 was used as chemical modifier 26A1 was used for studies of absorption and renal excretion of Al in human subjects Increased concentrations of Al and Fe were seen in the melanin-containing cells in the substantia nigra of subjects with Parkinson's disease ionized elements was investigated. A procedure for analysis of undiluted samples was presented Practical aspects of sample collection cleanliness etc.were given A1 and Fe were fed to snails in a study to determine if metabolism of Al resembles that of Fe Specimens were collected at an A1 foundry and an AIF manufacturing site. Airborne Al concentrations correlated with urinary levels. Foundry workers had higher urinary Al concentrations than those from the AIF plant Clearance of A1 from blood following a single injection into the portal or systemic circulation was measured to determine uptake by the liver gangliosides The effect of instrumental conditions Ca and easily Vitamin D prevented AI-induced alterations in brain Liver milk AA;ETA;L A1 Serum dialysis fluid water AA;ETA;L 93/1025 Al Brain AA;ETA;L AE;IC P L 9311026 9311058 A1 Serum Al Serum proteins AA;ETA;L 9311059 Al Serum dialysis fluids water biological tissues A A;ETA; L AE;F NZO-CZH2;L MS;ICP;L AA;ETA;L XRF;-;S AA;ETA;L MS;-;S L M MA;-$ A E; I C P;L AA;ETA;L A A; ETA; L A A;ETA; L A A; ETA; L 93/1060 Blood urine bone 9311 116 93/1800 9312185 Al Al Al Hair Serum Al Al Biological materials Brain 9312537 93/29 19 A1 Serum 93/c3000 A1 Al A1 Pharmaceuticals Blood biological tissues Serum urine 9313 156 93/35 1 1 9313675 A1 A1 Blood bile Brain 9314043 9314074 A E;ICP; L LMMA;-;S90 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) Element Al Technique; atomization; analyte form* AA;ETA;L Reference Sample treatment/comments Matrix Skin serum High concentrations of A1 were determined in sub- cutaneous nodules which can develop at sites of vaccination against diphtheria/tetanus/pertussis/ poliomyelitis The mean lymphocyte A1 concentrations in normal subjects and in patients on haemodialysis were 18.4 and 23.8 pg g consumption of Al in tea occupational monitoring were discussed dialysis concentrates 1 + 35 with a diluent to give final concentrations of HNO and Sc of 0.16% m/v and 50 pg I-' respectively.For ETAAS samples were diluted 1 + 4 with Mg(NO,),-Triton X-100 (serum) or Mg(NO,) (dialysis solutions). Standard additions calibration was used graphite furnace with 5 p1 chemical modifier (0.1 YO Triton X-100 in 0.25% HNO ) and 9 pl H,O. Calibration was by a standard additions procedure Serum specimens were diluted 1 + 1 with HzO Microwave bomb digestion was used to prepare solid materials.The solutions were diluted and In was included as an internal standard. The effects of N added to the coolant auxiliary and nebulizer gas flows on C1-based interferences were studied and best results were obtained with 4.5% N in the nebulizer gas flow As was introduced by HG interference associated with 40Ar3sCl was removed by optimization of operating conditions Small fragments of individual hairs were analysed with ETV used for sample introduction Enhancement of the signal by carbon compounds in the specimen was investigated Samples placed as a thin film on a quartz reflector were prepared for TXRF by microwave heating. The usefulness of chemical modifiers to minimize loss of volatile elements was studied range of methods for separation and measurement of As species.Sample preparation is the analytical area with most problems HNO and 50 pg V,05 in a digestion bomb inside a microwave oven. The cooled digest was diluted to 25 ml with H,O. A further 25 ml of 1.5% HCl were added and 10 ml of this solution taken for analysis. Recoveries were 96- 100% Isobaric fractionation to remove the 40Ar3sC1 interference on "As is not accurate. A new method based on the 1603sCl to 40Ar3sCI ratio was presented and results were in close agreement with those obtained by ETAAS Organoarsenic species did not react to form the hydride and therefore exposure to inorganic As could be monitored. Calibration by standard additions was essential for accurate results Eight As compounds were separated by anion- and cation-exchange HPLC which also removed the ArCl' interference As was introduced to the ICP by HG.An interference from Ni was overcome by coprecipitation of As with La(OH) (in Korean) ingestion of arsenious acid were diluted > 500-fold with 0.02 mol I - ' HNO (in Japanese) Inorganic As and its metabolites were separated from organoarsenic compounds of dietary origin with disposable cation-exchange columns and the two fractions analysed 93/41 13 protein respectively Plasma concentrations were measured after Practical aspects of sample collection and analysis for Samples for ICP-MS were diluted serum 1 +4 0.5 ml serum + 1.0 ml H20 6 p1 taken into the 93/c 135 1 931C1437 93/C 1508 93/C 1 6 1 5 This review commissioned by IUPAC examined a 9312565 Powdered sample 200 mg was heated with 2.5 ml An FI system was used with untreated urine.Specimens collected from a case of suicide by A1 Lymphocytes AA;ETA;L 93/41 15 941105 941176 9416 10 AA;ETA;L A A;ETA;L AE;ICP;L A1 A1 A1 Plasma Urine plasma Serum dialysis fluids MS; 1CP;L AA;ETA;L 9416 1 1 A A;ETA; L A1 Serum A1 As Serum Biological materials A A;ETA; L MS;ICP;L 9416 12 9311022 As Biological fluids MS;ICP;L Hair Blood urine Serum urine MS;ICP;S M S;ICP; L X R Fi-; S As As As Biological materials As As Fish AA;H y;L 9312682 M S;ICP; L 931293 1 As Urine A A; H y ; L 9313084 Urine As M S;IC P;L AE;ICP;L MS;ICPL AA; ETA;L 9313224 9313262 9 313 5 12 94137% As As As As Urine Hair Blood gastric contents UrineJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) 91 R Technique; atomization; Element Matrix analyte form* As Urine AE;ICP; L Sample treatmentlcomments HPLC resolution was enhanced by use of vesicles as the mobile phase. Didodecyldimethylammonium bromide (DDAB) vesicles pumped through a C,8 column modified by DDAB solution rapidly separated four As species. The eluent was coupled to an HG device for greater sensitivity Urine 10 ml was diluted with 30 ml of 0.04 mol I-' HNO and 1 ml of 1% w/v SnCI2.2H,O added. To 5.5 ml serum 0.5 ml of 1.7 mol of I - ' CH3C02H and 1 ml of the SnCl reagent were added. Samples were added to columns of Dowex-1x8 and the As and Se were eluted for measurement with Ga as internal standard. The use of cation-exchange columns eliminated spectral interferences in the plasma.Best results were obtained with the resin in the nitrate and acetate forms for urine and serum respectively by HPLC with ICP-MS as the detector boron neutron capture therapy was reviewed Metabolites of Au antiarthritic drugs were separated Subcellular distribution of B in cancer patients after A case of Bi toxicity was described A Xe arc lamp and photodiode array detector were used to construct an AA spectrometer for SIMAAC. This new instrument provided low detection limits. Ca and Cd were determined to test the system with Bi as an internal standard Alkaloids (amylocaine papaverine and bromhexine hydrochloride) were measured indirectly as complexes with Bi14- and CO(SCN),~- extracted from aqueous solution into 1,2-dichloroethane Stable isotopes of Br Ce and I were administered as tracers in studies of extracellular fluid volume red cell volume and other kinetic parameters Residual carbon which remained after decomposition of specimens by high-pressure ashing or microwave heating was measured at the C I 193.091 nm line [ l-'3C]leucine as substrate Muscle protein synthesis was measured with See Bi ref.931C1467 Optimal conditions for collection storage and transport of specimens for the measurement of ionized Ca were given in an International Federation of Clinical Chemistry Report Hypercalcaemia induced the calcification of aortic tissue with Ca-P salts laid down in the aortic wall and the eventual formation of hydroxyapatite crystals with pneumonia-induced respiratory failure (in Chinese) and calcification in heart valves was demonstrated in a multichannel system for accurate simultaneous measurement of Cd and Pb organic material and to form the less volatile oxide species HN03 (in Chinese) desorbed with HCI.The detection limit was 0.22 ng ml - ' (in Chinese) Intra- and extra-cellular Ca was measured in children A close relationship between mechanical stress NH,H2P0 was employed as the chemical modifier O2 ashing was utilized to improve destruction of Samples were diluted with (NH,),HPO and 1 O/O Cd was concentrated on sulfhydryl cotton and See Bi ref. 931C1467 Solid sorbent columns containing DDC were used for on-line preconcentration and removal of constituents of the matrix. Methods to improve efficiency with Cu-Fe rich biological samples were developed Reference 941596 As Urine serum M S;I C P;L 9416 13 Au B Urine Biological tissues MS;ICP;L MS;-;S 931 143 7 9312293 Bi Bi Plasma Urine M S;I C P; L AA;ETA;L 931C1066 931C 1467 9313398 Bi Alkaloid drugs AA;F;L 9312873 9312048 Br C Blood Biological materials XRF;-;S AE;IC P; L C Muscle MS;-;L 93/29 18 931C1467 9312683 Ca Ca Urine Blood plasma serum AA;ETA;L .. _ _ - 7 9313524 PIXE;-;S AA;F;L Ca Aorta serum 9313565 Plasma. red cells AA;F N20-CzH2;L Ca 9314030 Ca Heart valves AA;F;L XRF;-$ 9311 134 Cd Blood serum A A; ETA; L A A;ETA;L 9311 136 Cd Blood 9311 145 9311 147 Urine Urine A A;ETA;L AA;F;L Cd Cd 93/C 1467 93/c 1524 Urine Urine A A; E TA; L AA;F;L Cd Cd92 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 1 (continued) Technique; atomization; analyte form* Sample treatmentlcomments Reference Element Matrix Cd Urine AAETA;L Graphite probe atomization with deuterium 9312081 background correction was used to measure Cd in urine after 1 + 3 dilution with H,O and without the use of chemical modifiers.The procedure was recommended for monitoring occupational exposure to Cd Sample was passed through an ASV flow cell for deposition of analyte with separation from interfering components and concentration when stripped from the electrode. The ICP-MS was coupled to the ASV flow cell to form a single on-line sample preparation and detection system evaporated and the residue was dissolved in H20 and Fe"' added. An FI system was then used for on-line reduction with ascorbic acid and coprecipitation of the analyte on a hexahydroazepinium hexahydroazepine-l- carbodithioate-Fe" complex.The precipitate was dissolved in IBMK for analysis by FAAS. Enhancement in sensitivity was more than Tissues were digested with acids the solution was 40-fold With 0.03 mol 1-' HN03 as the chemical modifier very good recovery precision and detection limits were obtained using an electrographite tube Tissue homogenates at pH 8.6 were heated at 60 "C for 5 min centrifuged and the supernatants were filtered. The filtrates were run through an ion- exchange column to separate metallothionein isoforms. Cd was measured in the eluates to determine the metallothionein Cd in samples digested by microwave heating was complexed and extracted with 1,5-bis(di-2-pyridylmethylene) thiocarbonohydrazide in IBMK.The detection limit was 0.1 ng ml-' HPLC. The eluent was thermosprayed with 0 and the sample atomized in the resulting flame. The atomic vapour was carried into a T-shaped tube in the optical beam. See also Cd ref. 9313240 Samples were placed in the furnace on a graphite boat. Results reflected pollution in the area where the tobacco was grown A thermospray interface was developed to couple eluate from an HPLC column or FI system to an AA spectrometer nebulizer. The interface was compatible with a range of HPLC mobile phases and improved detection limits. See Cd ref. 9312897 '%Cd was added to specimens for internal standardization. Samples were then digested with HN03-H20 and the Cd complexed with lithium bis(trifluoroethy1)dithiocarbamate for separation by GC with MS for detection Heating conditions sample volume and matrix composition were examined and a graphite platform method proposed which involved aqueous standards for calibration Digested tissue samples or diluted urine specimens were loaded onto an FI manifold to mix with 0.05% diethylammonium-NN-DDC.The complexes formed were pumped and extracted onto a column of RP-C18 sorbent and eluted into the nebulizer with methanol. The sample rate was 85 h-' and a 20-fold enrichment factor was achieved Digested samples were applied to a simple open tungsten-coil furnace and resistance-heating was controlled by a four-step programmable power Cd-metallothionein species were separated by supply MS;ICPL 9312090 Cd Urine Biological tissues AA;F;L 9312121 Cd Cd Urine A A; ETA; L 9312673 Cd Kidney liver AA;ETA;L 9312684 Cd Urine biological tissues AE;ICP;L 9312720 Cd Biological materials AA;F;L 9312897 AA;ETA;L AA;F;L Cd Cd Tobacco Biological materials 9313 109 9313240 Cd Urine MS;-;L 9313597 Cd Cd Urine Biological materials A A; ETA; L AA;F;L 9313953 941267 Biological materials A A; ETA;L Cd 94/28 5JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) 93 R Technique; atomization; analyte form* Element Matrix Sample treatmentlcomments Goat tissues were digested with HNO and H2S04 and the residues dissolved in H20. Citrate was added to the solutions the pH adjusted to 2.5 and the Cd extracted into 5% Aliquat 336 in IBMK. The pH of the aqueous layer was adjusted to 6.8 and Zn was extracted into 5% Aliquat 336 in xylene.The Cd was back-extracted into 0.1 mol 1-’ HClO On-line preconcentration and a slotted quartz tube atom trap increased sensitivity for analysis. The detection limit was 0.14 pg 1-’ Fluids were deproteinized by addition of HNO and matrix-matched calibration solutions were prepared See Br ref. 9312873 See Cd ref. 9312121 An internal standard 62Ni was added to the sample and lithium bis( trifluoroeth yl )dit hiocarbamate chelates formed for GC Amylocaine papaverine and bromhexine HCl were measured indirectly as complexes with Bi14- and Co(SCN),’- extracted from aqueous solution into 1,2-dichloroethane Powdered samples were ashed in a muffle furnace to reduce the mass and increase the analyte concentration by 5- to 50-fold maintained with normal blood glucose but increased insulin levels Washed hair was immersed in HNO for several h H20 and an emulsifying agent were added to stabilize the colloidal form and the Cr.The suspension was analysed on a graphite platform coated with La (in Chinese) Plasma Cr concentrations fell when volunteers were See Al ref. 9312185 The effects of an oral glucose load on Cr metabolism were investigated Sample preparation instrumental parameters and interferences were discussed in a review article After dry ashing the samples were dissolved for analysis. Mg(NO,) was added as a chemical modifier See Al ref. 93/1058 Families of patients with Wilson’s disease were studied by various investigative approaches including measurement of total liver Cu in biopsy specimens and uptake of the stable isotope 65Cu major trauma were likely to develop hypocupraemia.However hypozincaemia was seen in both groups of patients Concentrations changed with the age of salmon raised in pens. Use of a CuO algicide in the pens did not affect the Cu content of the samples Further detail of the 65Cu oral uptake test given in ref. Cu 931C1062 SR-XRF analysis was used to determine the surface concentration of Cu Se and Zn in kidneys from men aged 22,44 and 61 y. See Cu ref. 9312864. (in Japanese) In a continuous on-line system a slurry of the sample in HN0,-H202 ( 1 + 1) was transferred through a microwave oven for 2-4 min and then to the nebulizer Patients with severe burn injury but not those with See Cd ref. 93/2090 Lower concentrations of Cu Se and Zn were found in kidney tumour compared with normal tissue using SR-XRF (in Japanese) See Cd ref.93/3240 Ten new RMs were characterized with ID for Cali brat ion Reference 9414 1 4 941428 94/56 1 9312873 931212 1 9312423 9313398 9313940 93/C 1064 9312171 9312185 9 313 9 74 9314024 9314027 9 31 1058 93/c1062 93/C 1065 9311 102 931C1338 9311 7 14 9312082 9312090 9312864 9313240 93/3544 Cd Biological tissues AA;F;L Cd Blood AA;F;L Cd Seminal fluid AA;ETA;L Ce c o c o Blood Biological tissues Urine XRF;-;S MS;-;L AA;F;L c o Alkaloid drugs AA;F;L c o Biological materials A A;ETA;S Cr Plasma AA;ETA;L Cr AA;ETA;L Hair Cr Cr Serum Plasma urine A A;ETA;L A A; ETA;L Biological materials A A; ETA; L Cr Cr Biological materials AA;ETA;L cu c u Serum Liver A E;IC P;L MS;ICP;L AA;F;L cu Serum c u Fish muscle liver AA;-;- XRF;-;S cu cu Serum Kidney MS;ICP;L XRF;-;S AA;F air-C2H2;S1 c u Biological tissues c u c u Urine Kidney MS;ICPL XRF;-;S cu c u Biologcal materials Biological materials AA;F;L M S;IC P;L94 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) Technique; atomization; analyte form* Sample treatmentJcomments Reference Element Matrix cu Biological materials AA;F;L Samples were efficiently digested with very small 9313942 volumes of acid in a microwave oven. The vessels were continuously rotated to give uniform exposure to the microwaves. Digested samples were analysed with an FI system Saliva and serum samples were deproteinized and urines were centrifuged. Addition of a Schiff base Cu [ 2-benzoylpyridine thiosemicarbazone] formed a complex with thiocyanate which was extracted at pH 5.2-9.0 into isopentyl acetate.The organic layer was removed for AAS in this indirect method for the measurement of thiocyanate dog mouse and rat. Cu distributions were different in the various species Concentrations were higher in a group of lead workers compared with normal subjects Results obtained by colorimetric methods and by AAS were compared Methanolic 0.05% Nafion I17 was dried on tungsten wire coiled in a 3 mm disc. The coil was immersed in a Cu solution dried and placed into a graphite cup for ETA of the Cu. The coil was then immersed in the Cu solution to which arginine had been added. The difference in absorbance was proportional to the concentration of arginine and provided an indirect method for measurement of this amino acid Total Cu and Cu-binding proteins were measured in See Cd ref.941267 941267 Changes in the Cu and Zn concentrations in the 941452 amnion chorion and placenta throughout the course of the pregnancy were followed See Al ref. 9311 800 9311 800 Lettering on a tablet was scraped off and dissolved in 93/c 1439 HNO + HF for the measurement of Fe in a study to determine the amount of ink transferred onto tablets during manufacture Fe species associated with tissue proteins were separated by HPLC coupled to ICP-MS for detection preparations was assessed with 54Fe used as a tracer and isotope measurements achieved with 9 312 3 22 Bioavailability of Fe from pharmaceutical 9312550 FAB-MS See Al ref. 9312919 9312919 "Fe and 58Fe were administered to subjects in a 9312932 study to determine absorption of non-haem Fe in pregnant women See Al ref.931351 1 Post mortem tissue specimens were digested with 931351 1 9313598 HNO for the measurement of Fe. Co was also determined and the results used to calculate the carboxyhaemoglobin content of tissues in forensic cases where the usual methodology is inappropriate association with prostatic diseases were determined Mutation forms of the enzyme had no activity and virtually no Fe Dissolution with HNO digestion in HN0,-HClO and dry ashing were compared as preparative procedures. Poor precision and low recoveries were obtained and Fe appeared to be lost as silicate and phosphate precipitates. Best results were achieved with the acid digestion A Gd complex used for magnetic resonance imaging was also used to measure permeability of the blood-brain barrier Uptake into and distribution of Gd in the brain was determined after administration of Gd-containing drugs (in Japanese) Some changes in Fe and Mg concentrations in Fe associated with 5-lipoxygenase was measured.9313963 cu Serum urine saliva AA;F;L cu Serum AA;-;L 9314098 9314 1 16 94/82 941230 AA;F;L AA;F;L A A; ETA; L c u cu cu Plasma Serum Pharmaceuticals AA;F;L A E; DC P; L cu cu Biological materials Placental tissues XRF;-;S A E;I C P; L F Fe Hair Pharmaceutical tablets M S;ICP;L Fe Biological tissues Biological materials MS;-;S Fe LM MA;-;S MS;ICP;L Fe Fe Brain Erythrocytes Blood biological tissues Biological tissues A A ;ETA; L AA;F;L Fe Fe 93/41 14 941 1 30 941168 Fe Fe Fe Serum prostatic tissue Bacterial enzymes Biological materials AA;-; - AA;ETA;L AA;F;L A E;I C P; L A E; IC P; L 93/33 1 1 94/454 Gd Gd Plasma tissues Blood brainJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 95 R Technique at om i n t i o ti analyte form* Element G e Hair Matrix Sample treatment comments Reference AF:HG;L Hair w;is ivashed and dissolved in HNOJ H,PO 93 7151 ( 9 1 ). 30?4 H,O was added and boiled to reduce the volume. This was mixed with a small amount of 0 s in Ii,SO boiled and an aliquot taken for HC; (in Chinese) Effects of acids and other elements (Ca. CI. K. Mg. Na) on the Ge signal was examined. HNO did not influence the intensity (in J a pa nese) IBMK and dissolved in DMF.The graphite tube was inipregnated with ammonium molybdate and NaOH was used as a chemical modifier (in Chinese) HG sample introduction was employed. Digestion procedures to avoid losses by volatilization. acid e k t s on reduction to the hydride and inter- element interferences were all investigatcd 0.1 g was heated with 2 ml of HNO in a scaled PTFE container in a microwave oven and the solution diluted as required with 2"h nitric acid. For IC'P-MS an internal standard. TI. was included and the diluent contained 0.1"h Triton X-100 air correlated with the number of amalgam restorations in the mouth CuSO and KBr- H,SO solutions were added to samples and the organomercury compounds were extractcd into C,H,. The organomercury species were separated by capillary G C and heated in a stainless-steel pyrolyscr to form the elemental Hg (in Chinese) oxidation and the Hg determined with an FI procedure Inorganic and organic Hg species were ethylated and then separated by GC.The derivatives were decomposed to HgO for measurement by CVAFS. Improvements to a previously described technique were presented See As. ref. 93!C 16 15 Diluted urine samples were chromatographed to A Ge -phenylfluorone complex was extracted into Measured concentrations of Hg in urine and exhaled KMnO HISO was used for off-line sample 9 3 c I 540 93 ( ' I 544 separate H g and Pb species. The column eluate was connected to a direct injection nebulizer for rncasuremcnt of the metals by ICP-MS Samples were mixed with an HCI EDTA-cystcine diluent. centrifuged and the supernatant filtered through ii frit ended screening column Samples were placed into the furnace on a platinum boat. Results reflected pollution in the area where the tobacco was grown Hair heated with HNO,- HCIO was further oxidized with KMnO and HNO,.Excess oxidizing agent was removed by hydroxylamine HCI and the Hg2 ' reduced with SnCI (in Chinese) reaction chamber. The trap was ;I quartz tube with gold-coated sand. fig vapour collected on the trap was desorhed by heating resistance wire coiled around the tube. Preparation and orientation of the trap influenced the shape of the absorbance signal. A detection limit of less than 1 pg was reported Methylmercury i n the eluate from a GC was measured by AAS with a laboratory-built i n tcrfiice A manifold was constructed for automated on-line transport of solution through a microwave oven and then to a reaction accessory for formation of H g vapour and measurement.Good recoveries for five Hg compounds were obtained. The system \vas also described in refs. 93 '37 17 and 93 27 1 X An amalgam trap was fitted to the exit of the CV Gc Serum. biological tissues M S;I C 1'; L 93 2301 Ginseng AA ETA;L 93 3947 Ge I rg Ginseng Fish muscle A E:IC P; L 94,179 93 100s M S I C P; L AF;CV;I tlg Blood. urine. exhaled air Biological m ;i t eria I s AA;CV:L AA -:L 93 1'12 93.1236 Hg Hg Urine Biological samples A A:CV L AF:CV:L H g Hg Serum urine Urine XRF;- -:S MS;ICP;L 93 C1615 93.1943 1-1 g 14 g H g Blood. urine Tobacco Hair MS;IC P:L AA:ETA:L AF:CV;L 93 '2426 93 3109 93 3134 Hg Hair A F;CV;L 93 3329 Hg tlg Biological tissues Urine AA:GC;G AA:CV:L 93 3641 93 392496 R Table 1 (continued) JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Technique; atomization; analyte form* Matrix Sample treatment/comments Reference Total and inorganic Hg were measured in blood of 9314037 dentists and non-dentists to determine if methylation of Hg vapour occurs. The organomercury concentrations were similar in both groups although total Hg levels were higher in the dentists Instrumental features were investigated to develop a sensitive method for measurement of methylmercury by headspace GC with MIP for detection. A Beenakker type cavity with an Ar plasma and measurement of A F provided the lowest detection limit 12.5 ml urine + 1 ml of 1 mg ml-' Pd and 0.15 ml HNO was diluted to 25 ml with H,O.20 p1 was injected into the graphite furnace and the detection limit was 0.26 ng (in Chinese) An FI system was developed which provided efficient vaporization and was very sensitive. On-line and off-line procedures for oxidation of organomercury compounds were described Tissues (0.25 g) were solubilized by heating at 60 "C with4mlof10g1-'NaCl-2mlof 1Ogl-' cysteine-2 ml of 450 g 1-' NaOH. Methylmercury was photoxidized in an aliquot for measurement of total Hg by acidification with 6 mol I - ' HC1-potassium persulfate. A second aliquot was untreated to determine inorganic Hg. Solutions were reacted with NaBH for formation of the Hg vapour in a continuous flow manifold Methylmercury was separated by HPLC from other Hg species and presented to the ICP via an ultrasonic nebulizer Hg in digested samples was reacted with 1,5-bis(di-2- pyridy1)methylene thiocarbanohydrazide. The complex thus formed was extracted into IBMK and mixed with SnCI in DMF.Hg vapour was transferred to the ICP as the final step of this completely automated FI system fixed embedded thyroid tissue sections were defined effects but suppression due to Na K and urea required standard additions calibration for accurate results (in Japanese) Conditions for SIMS measurement of lzSI and 1291 in Diluent containing 0.1 O/O NH40H prevented memory See Br 9312873 I and five iodo amino acids in enzymic digests of thyroglobulin were separated by HPLC. ICP-MS provided detection of 35-130 pg as I Intracellular K+:Na+ ratios were used to provide information on the physiological condition of bacterial populations Concentrations were measured in specimens from healthy men living in six counties and variation in normal levels was found among these groups Myocardial and skeletal muscle specimens were solubilized in HNO mononuclear blood cells were separated by density gradient centrifugation.Samples were then diluted 200-fold with 15 mmol I-' LiCl with H,O. There was no matrix effect and readings were taken with background correction. The assay was sufficiently sensitive to measure Li in specimens from subjects who were not receiving therapeutic Li. The normal concentrations (mean & SD pg 1-') were 1.17 + 11.7 in urine AnID technique was described. A 6Li tracer was added to the sample dried and extracted with HCl.The extract was treated with H,Oz and rapidly chromatographed on paper to remove interfering species before analysis Serum samples were diluted 2 + 5 and urine 1 + 1 0.47 in serum and 29.3 Element Hg Blood AA;CV;L Biological materials AE;MIP;G AF;MIP;G 94170 Urine Urine Kidney liver brain A A;ETA;L AA;CV;L A A;CV;L 941 1 50 941225 941422 Biological tissues biological MS;ICP;L fluids 941575 941519 Biological materials AE;ICP;L Thyroid Serum urine MS;-;S MS;ICP;L 9312292 9312300 I I Blood Thyroglobulin XRF;-;S MS;ICP;L 9312873 9313435 K Bacterial cells LMMS;-;S 9312434 AE;F;L K Serum 9313507 K Muscle. blood cells AE;F;L 941379 Li Serum urine AE;F air-C,H,;L 9311038 Li Plasma urine M S;-; S 9312296JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) 97 R Technique; atomization; analyte form* Element Matrix Sample treatmen t/comments Reference 9313232 A graphite microboat with a layer of tantalum foil was inserted into a graphite cuvette. Samples were pipetted onto the foil and the cuvette heated to effect atomization. Sensitivity was better with the foil compared with an ordinary boat ID-TIMS was described. Specimens were first digested with HN0,-H,O and the Li separated from the residue by cation-exchange chromatography Samples were dry ashed with 1% H2S0 as an ashing aid to prevent losses of volatile Li. Effects of other ions were studied. The method was suitable for monitoring patients receiving lithium therapy Biopsy specimens were lyophilized and the protein digested with Pepsin A.The supernatant obtained by centrifugation was diluted with LaCl solution and the Mg determined concentrations were found after high-intensity exercise. These may have been consequences of changes in plasma volume Certification procedure for two BCR RMs by 9313448 9314017 93/21 15 Small increases in the plasma and red cell Mg See Fe ref. 93/41 14 Myocardial and skeletal muscle specimens were solubilized in HNO,; mononuclear blood cells were separated by density gradient centrifugation. Samples were then diluted 40-fold with 5 g I - ' LaCl brain from patients with Parkinson's disease compared with normal brains (in Japanese) Lower Mg concentrations were found in areas of the See Cu ref. 93/2082 Powdered samples were analysed from a molybdenum furnace with Ar-H used as the purge gas.Interferences were removed by addition of thiourea and aqueous solutions were employed for calibration Pd-hydroxylammonium hydrochloride as chemical modifiers was investigated. Octanol was included together with modifier for pipetting milk specimens from two French cities; 38f20 pg per 24 h sample 25 & 10 pg 1-' 21 &9 pg per g creatinine The effectiveness of Pd-Mg( NO,) and 9 3/C 1 636 Urinary concentrations were the same in subjects See Cu ref. 9313544 Sodium bis( trifluoroethy1)dithiocarbamate complexes See K ref. 9312434 Samples digested in a closed vessel with of Mo isotopes were determined by GC-MS HN0,-H202 were evaporated almost to dryness and redissolved in 1 mol I-' HCl. The evaporation and dissolution steps were repeated. 1 pl solution was injected into a molybdenum capillary tube (250 x 1.22 mm i.d.) which served for atomization separation and detection for sequential vapour elution analysis.The Na vapour was separated from Al Ca Cu Mo and Zn vapours 200 mg sample was heated with 4 ml HNO and 2 ml HCI in a digestion bomb within a microwave oven. Solutions were further heated to reduce the volume to 0.5 ml and remove HNO and the pH was adjusted to 3.6. 10 ml of glycine-HCI buffer and 2 ml of 1 moll-' NaClO were added and the volume made to 250 ml. 125 ml was placed in a separating funnel and the Ni extracted into 15 ml of 0.05% 1,5-bis(di-2-pyridylmethylene) thiocarbonohydraxine in butan-1-01. The organic phase was taken for the determination of Ni at 341.4 nm Heparinized blood samples were diluted with H20 (in Japanese) Li Renal tubular fluid AA;ETA;L Li Serum MS;-;S Li Blood urine saliva AA;F;L Myocardial biopsies AA;F air-C,H,;L Plasma red cells AA;F;L 9313323 Serum prostatic tissue Muscle blood cells 93/41 14 941379 Brain AA;-;- 941466 AA;F air-C2H2;S1 A A;ETA;SI 9312082 9313938 Mn Mn Biological tissues Biological materials Mo Serum urine milk A A;ETA;L MS;ICP;L 9312355 Mo Urine Mo Mo Biological materials Biological materials MS;ICP;L MS;GC;L 9313544 9313776 9312434 9313230 Na Na Bacterial cells Biological materials LMMS;-;S AA;ETA;L Biological materials AE;ICP;L 9311034 Ni 9311 146 Ni Blood AA;ETA;L98 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) Technique; atomization; analyte form* Element Matrix Ni Biological tissues Ni Biological materials Ni Serum urine Sample treatmentlcomments Reference AA;F;L See Cd ref.9312121 A A; ETA$ See Co ref. 9313940 MS;ICP;L 200 pl of serum were heated at 95 "C for 4 h with 300 pl HNOJ and the volume made to 2 ml with H20 and Rh internal standard. Principal components analysis was used to correct for spectral overlap from CaO + and CaOH + . Oxalic acid was added to urine samples to remove Ca by precipitation of the Ca oxalate containing 1,5-bis [ phenyl-( 2-pyridy1)methylenel- thiocarbonohydrazide. A high (37) aqueous:organic ratio could be used to effect large enhancement of concentration African quality assessment scheme was presented Ni in the sample was extracted into IBMK Performance of participants in a South See Cd ref.9311 134 See Cd ref. 9311 136 Dermal absorption of 204Pb was investigated. There was good agreement between the techniques at concentrations of < 1 pg I temperature were analysed with Pd-HNO chemical modification Radiation exposures associated with Io9Cd XRF instruments used for in uivo bone Pb determinations were measured Tibia Pb concentrations in a cohort with occupational Pb exposure were remeasured 5 years after an earlier investigation Vacutainer blood collection tubes were tested for Pb contamination. Tubes of different types were incubated with H20 for up to 7 d. The special trace element tubes showed higher contamination than in the chemistry and haematology tubes 50 ml of urine and 2 ml of 10% Bi(NO,) was adjusted to pH 8.9 and 10 ml of ethanol were added.The precipitate was recovered by centrifugation dissolved in 4 ml of HCl and diluted to 10 ml with H,O (in Chinese) was described tissues and environmental materials to determine sources of exposure Biopsy samples dissolved in HNO at room Certification of a Pb in a blood SRM using ID-MS Pb isotope ratios were measured in blood body See Cd ref. 9313109 Atomization of Pb was studied with Pd-citrate or NH,H,PO,-Mg( NO,),-citrate solutions as chemical modifiers. A recommended method with Pd-citrate was developed See Cd ref. 9313240 Radiation exposure doses for the non-invasive determination of Pb in bone were calculated on the basis of revised recommendations Application of XRF to in uiuo determination of Pb in bone was reviewed In uivo methods for assessment of the body burdens of metals (NAA for Cd and XRF for Pb) were discussed In a comparison study a combination of 6 pg of Pd and 15 pg of Mg was found to be the most effective chemical modifier for use with diluted samples.Different optimal heating conditions were determined for each sample type Umbilical blood Pb concentrations were measured in babies from a district of Germany. Factors associated with the concentrations were age of mother season lead water pipes vicinity of roads. Concentrations were independent of rurallcity location or parental occupation (in German) 9312121 9313940 94/565 Ni Urine AE;ICP;L 94/60 1 Pb Blood . . -- 931C989 AA;ETA;L AA;ETA;L M S;ICP;L MS;TI;S 9311 134 9311 136 93JC1339 Pb Pb Pb Blood serum Blood Sweat urine 93/C 1548 Pb Bone A A;ETA;L XRF;-;S 9311 769 Pb Bone Bone XRF;-;S 9311860 Pb Pb Water blood AA;ETA;L 93/21 17 Pb Urine AA;F;L 9312148 M S; I C P; L M S; I C P; L Blood Blood tissues Pb Pb 93JC3016 93/c3041 Pb Pb Tobacco Serum urine blood A A;ETA;L AA;ETA;L 9313109 9313233 Pb Pb Biological materials Bone AA;F;L XRF;-;S 9313240 9313 8 74 Pb Pb Bone Bone X R F;-;S XRF;-;S 9313896 9313897 Pb Blood urine milk A A; ETA;L 9313955 Pb Blood AA;ETA;L 93/41 28JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 1 (continued) 99 R Technique; atomization; analyte form* Element Matrix Sample treatmentlcomments Reference 941284 Pb Biological materials AA;ETA;L In an automated system powdered samples suspended in 0.4% Triton X-100 and diluted with HCl-HNO were pumped through a PTFE coil in a microwave oven.The digested samples were de-gassed and an aliquot transferred to the graphite furnace NH,H,P04-0.5% m/v Triton X-100-0.2% HNO and 12 pI portions pipetted onto a L'vov platform within a transversely heated atomizer Samples were diluted 1 +9 with 0.2% m/v See Cd ref. 941561 Samples were diluted 1 + 3 with H,O and the Pb was atomized from a graphite probe. Accurate results were obtained without chemical modifiers and with aqueous calibration solutions Dry ashing with or without 0 plasma as an ashing aid followed by dithizone extraction and measurement by AAS gave unreliable results with poor recovery of added Pt. No such problems were evident with wet ashing procedures. There were no interferences from Ca or Mg (in German) Good sensitivity of ICP-MS allowed measurement of total and free Pt after dilution of samples Microwave bomb digestion was used to prepare solid materials.The solutions were diluted and In was included as an internal standard. The effects of N2 added to the coolant auxiliary and nebulizer gas flows on C1-based interferences were studied and best results were obtained with 4.5% N in the nebulizer gas flow Spectral interferences caused by CaCl and MgCl were reduced by inclusion of a suitable chemical modifier (PdCI or HgCI,) and an optimal ashing temperature Supernatants prepared following TCA precipitation were incubated at 70 "C for 10 min with HCI (in Chinese) technique (in Chinese) carefully investigated and controlled in a study which determined the variation of Se in different parts of the heart See As ref.931C1508 See As ref. 93lC1615 Radioisotope-induced XRF was used to determine Few interferences were observed in this sensitive Each step of the acid digestion procedure was the distribution and excretion of selenate or selenite in mice using '%e See Cu ref. 9311714 Three lyophilized blood specimens were analysed at 39 laboratories using seven different techniques to establish their Se concentrations and allow the use of these specimens as CRMs Newly designed continuous flow system for HG was used to minimize CI interference. Sample preparation gave a final solution with either 3.8 or 7.2 mol 1-' HCl. Cu interference was eliminated by inclusion of 0.2 mol I - ' NaI in the NaBH solution (3.8 mol 1-' method) or by maintaining the high (7.2 mol I-') concentration of HCl Samples wet ashed with HNO or HN03-HC104 were heated with 6 rnol l-.' HCl to form Se'" (in Japanese) Three derivatizing agents were investigated for GC of Se and 4-trifluoromethyl-o-phenylaminediamine was best with good precision and no memory effects. '%e was used for ID standardization See Cu ref.9312864 Measurement of 76Se 77Se and *'Se using HG for sample introduction was investigated to determine parameters for use of Se-enriched samples in tracer studies Pb Blood A A,ETA;L 941321 Pb Pb Seminal fluid Urine AA;ETA;L A A;ETA;L 941561 94 f583 Pt Biological tissues AA;ETA;L 9311092 9312297 9311022 Pt Se Plasma Biological materials M S; ICP; L IC P; M S;L 9311 027 Se Biological fluids A A; ETA; L 931 1238 Se Serum AA;HG;L 9311283 93/C 1436 Se Se Serum Heart tissue AF; H G; L A A;ETA;L 93/C 1 508 93/C 1 6 1 5 9311 712 Se Se Se Blood urine Serum urine Biological materials M S;I C P;L XRF;-;S XRF;-;S XRF;-;S .. 9 9311714 9311 771 Se Se Kidney Blood 9312 154 Se Biological materials M S;IC P; L Se Biological materials A A; H y; L 9312195 9312321 Se Urine MS;-;L 9312864 93/29 1 7 Se Se Kidney Biological materials XRF;-;S MS;ICP;LlOOR Table 1 (continued) JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Technique; atomization; Element Matrix analyte form* Se Urine AA;ETA;L Sample treatment/comments Reference 9313353 Samples were digested and HG was effected. The vapour was transferred by an Ar stream and adsorbed onto a heated Pd-coated graphite tube.Rapid heating caused atomization of the Se. Good recoveries were obtained with added selenomethioneine and selenocysteine. The detection limit was 20 pg See Cu ref. 9313544 '%e was added to specimens as the internal standard for capillary GC separation with MS detection Tissue samples were digested and the Se extracted into organic solvent for radioisotope induced XRF Optimal conditions for sample preparation and HG were evaluated (in Portuguese) Se was determined with Pd as the chemical modifier. Specimens from patients with Graves' disease had low concentrations of Se compared with healthy subjects Thermostabilizing effects of Ni(N03)2 and Pd( N03)2 on Se species in urine were investigated. The optimal amount of Ni and other conditions necessary to eliminate the effects of urine components on atomization of Se were also ascertained See As ref.941613 A chemical modifier which contained Ca( NO,)2 increased absorbance by 30% and gave comparable results to an established DCP-AE procedure. The appearance of Ca-Si structures within the furnace was investigated by SEM with EDXRF Urine was aspirated without any treatment. An artificial urine matrix was necessary for the preparation of calibration solutions. Results from ten individuals were 1.8-51.6 mg I-' and were associated with vegetable intake 0.5 ml serum + 1.5 ml 1% v/v HN03 Samples were diluted 1 + 9 and 1 + 3 with H20 for AAS and AES respectively. Aqueous calibration was used for AAS and standard additions for AES. Concentrations of Si in uraemic specimens were 893+3OO pg I-' Zeeman-effect background correction was used to develop and validate a method for samples diluted 20-fold with 2% HNO,.Concentrations in plasma and urine of normal subjects were 12.7-40.0 and 3.2-78.2 pg 1 - ' respectively (in French) A '19Sn spike solution was added before digestion in a closed vessel microwave heater (in Japanese) Samples were diluted for ICP-MS. Results agreed well with those obtained by ETAAS with Pd as chemical modifier. The ICP-MS detection limit was 10-fold lower than that of ETAAS. Microwave bomb digestion was used to prepare solid materials. The solutions were diluted and In was included as an internal standard. The effects of N added to the coolant auxiliary and nebulizer gas flows on C1-based interferences were studied and best results were obtained with 4.5% N in the nebulizer gas flow Tissues were dry ashed and the residues dissolved in HN0,-HClO,.Urine specimens were digested with HN0,-HCIO,. V in the samples was chelated with 8-hydroxyquinoline and cupferron and adsorbed onto activated carbon graphite platform a detection limit of 16 pg was obtained from a transversely heated furnace. The detection limit of V in urine was 0.3 pg I-' 5 p1 of sample were injected into the furnace dried and heated to 2825 K for atomization. Two dye lasers were aligned to irradiate the atoms and measure AF via the double resonance-excitation detection scheme. The detection limit was 10 pg 9312299 931C1486 9311022 93/C 1632 With 60 pl of untreated urine pipetted onto a Biological materials Serum red cells urine MS;ICP;L MS;-;L 9313544 9313605 Se Se 9313819 Se Biological tissues XRF;-;- AA;HG;L 9411 8 1 Se Serum AA;ETA;L 941549 Se Plasma AA;ETA;L 941584 Se Urine 9416 13 9311042 Se Si Urine serum Plasma protein M S;ICP;L AA;ETA;L AE;DCPL Si Urine AE;DCP;L 9311096 Si Si Serum Serum AE;DCP;L AA;ETA;L AE;ICP;L 9416 1 1 9416 12 Plasma urine A A;ETA; L 94/68 Sr Biological materials Urine serum blood MS;ICP;L Sn T1 MS;ICP;L AA;ETA;L V Biological materials 1CP;M S; L AA;ETA;SI V Urine biological tissues A A;ETA; L 9313082 v Urine V Blood serum LEAF;ETA;L 941555JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 101 R Table 1 (continued) Technique; atomization; analyte form* Element Matrix Sample treatment/comments Reference Zn Serum A E;IC P; L Zn Serum AA;F;L Zn Plasma blood cells AA;F;L See Al ref.9311058 9311058 See Cu ref.931C1065 93/C 1065 A method to measure Zn with an FI system was 9311 182 See Cu ref. 9311714 9311714 Zn in digested samples was extracted into CCI as a 9312059 complex with APDC and re-extracted into 1.2 mol I - ' HNO for measurement. The 70Zn:"Zn ratios were determined in studies of intestinal absorption in pre-term infants using foods enriched with "Zn A previously described method was modified to reduce CI in the assayed solution and thereby avoid interference on the measurement of "Zn in more than 120 subjects using FAB-MS to measure the stable isotopes was accomplished by centrifugation to separate non- protein bound Zn. The ultrafilterable Zn concentrations were 0.46 to 84 pmol I - ' (4 to 56% of the total Zn) See Cu ref.9312864 Conditions for efficient use of an open-focused presented Intestinal absorption and excretion of Zn was assessed Ultrafiltration through a cellulose acetate membrane microwave digestion system were explored with the aim of achieving <0.05% residual C and recovery of Zn of > 95% A colorimetric method and FAAS were compared. A positive bias was observed with the colorimetric assay Specimens from mice with the lethal milk mutation indicated that the defect in this condition was the production of Zn-deficient milk 9313778 9314042 See Cu ref. 9314116 Results obtained by colorimetric methods and by AAS were compared Samples were diluted 20-fold with water and readings were compared against those given by matrix- matched calibration solutions.The Ar gas flow was maintained during atomization to reduce sensitivity and avoid large dilution of sample 93/41 16 94/82 941377 See Cd ref 941414 See Cu ref. 941452 Zn Kidney X R F;-; S Zn Blood urine faeces MS;ICP;L Zn Zn Zn Serum liver Biological materials Breast milk MS;ICP;L MS;-;S AA;ETA;L 9312 132 9312504 9312714 Zn Zn Kidney Milk total parenteral nutrition medium biological tissues XRF;-;S AE;ICP;L 9312864 931c2999 Zn Zn AA;F;L AA;-;- Serum Blood milk biological tissues Zn Zn Plasma Serum AA;F;L AA;F;L Zn Serum AA;ETA;L Zn Biological tissues Zn Placental tissues AA; F; L AEDCPL 9414 14 941452 MULTI-ELEMENT ANALYSIS Serum plasma and blood Urine and blood samples were diluted 1 +9 with 0.1% Triton X-100 for determination of Cd by AAS.Other elements were determined in urine faeces and tissues. Faeces were digested with HNO and analysed by ICP-AES tissues were dried and compressed into pellets for PIXE Specimens were diluted 1 + 1 with H20 and deposited onto a graphite probe. No matrix interference was found and accurate results were obtained with aqueous calibration solutions (Cd Co Cr Mn Ni Pb) Concentrations of Cr Mg Mo and Zn in serum were lower in diabetics compared with their controls urinary Zn was increased (in Chinese) Measurement of Ca K Mg and Na in platelets was proposed as a more appropriate index of intra- cellular concentration than serum or leucocyte levels Trace elements in blood were excited for EDXRF by a radioactive source. This paper is also published in 9311653 ICP-AES was used for the determination of reference values for a large number of elements in liver kidney lung milk hair and serum from normal adult subjects Umbilical cord blood was collected and the plasma removed for measurement of Ca Mg and Zn by FAAS.Cu was determined by ETAAS. The study investigated relationships of these parameters to gestational age and growth 93/c994 Various (15) Urine blood faeces biological tissues AA;ETA;L AE;ICP;L PIXE;-;S Various (6) Urine blood A A;ETA;L 93/1016 Various (4) Serum urine AE;ICP;L 9311 109 9311 197 Various (4) Platelets AA;F;L AE;F;L Various Blood XRF;-S 9311 767 9312050 Various (23) Serum milk hair biological AE;ICP;L tissues Various (4) Plasma erythrocytes AA;F;L AA;ETA;L 93/2116102 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) Element Various ( 5 ) Various Various (6) Various (4) Technique; atomization; Matrix analyte form* Sample treatment/commen ts Reference Kidney red cells plasma AE;ICP;L Accumulation of As and interactions between As and 931329 1 other elements were investigated in rats fed As for up to 15 weeks (As Cd Cu Ni Pb) into the blood circulation in experiments to track blood movements within tissues. Samples were analysed by WDXRF and SR-EDXRF solutions and the use of chemical modifiers were described (Al Cd Co Cr Mn Pb) chemical modifier. Accumulation of residues in the tube required peak area measurements to be made (Cr Mn Ni Pb) As part of a project to determine reference values for trace elements requirements to prevent contamination or losses during sample collection and storage were ascertained 1 ml of sample heated with acid was prepared in 4.8 mol 1-' HCI.The solution was taken for nebulization and for HG (in Chinese) Approaches to the measurement of trace elements in serum and other samples were reviewed (B Mo Sn Zn) Blood XRF;-;S Microspheres loaded with heavy metals were injected 93/3818 Serum AA;ETA;L Calibration with aqueous- and albumin-based 9313935 Blood A A; ETA; L Undiluted blood was analysed with Pd added as a 9313939 . . -- Various (14) Blood 3 Various (30) Serum A E; I C P; L Various (4) Serum biological materials MS;ICP;L MULTI-ELEMENT ANALYSIS Urine Various ( 15) Urine blood faeces biological tissues Various (6) Urine blood Various (4) Serum urine Various ( 5 ) Urine Various (8) Biological fluids Various ( 5 ) Urine Various (4) Urine Various ( 5 ) Urine AA;ETA;L AEICPL PIX E;-; S A A;ETA; L A E; I C P; L AE;ICP;L A A; HG; L A A;CV;L A A; H G;L AA;CV;L AA;F;L A E;ICP;L MULTI-ELEMENT ANALYSIS Other biological fluids Various Milk AE;I CP; L Various (23) Serum milk hair biological AE;ICP;L tissues 9314 105 941402 94/59 1 93/C994 931101 6 Urine and blood samples were diluted 1 +9 with 0.1% Triton X-100 for measurement of Cd by AAS. Other elements were determined in urine faeces and tissues.Faeces were digested with HN03 and analysed by ICP-AES tissues were dried and compressed into pellets for PIXE deposited onto a graphite probe. No matrix interference was found and accurate results were obtained with aqueous calibration solutions (Cd Co Cr Mn Ni Pb) Concentrations of Cr Mg Mo and Zn in serum were lower in diabetics compared with their controls urinary Zn was increased (in Chinese) Improvements in stability and memory problems were evident with new ultrasonic nebulizers (Al Ba Cd Cu Mn) A manifold was constructed for automated on-line transport of solution through a microwave oven and then to a reaction accessory for HG or formation of Hg vapour and measurement.Further details are given in Hg ref. 9313924 and Various ref. 93/2718 (As Bi Hg Pb Sb Se Sn Te) Different oxidation solutions were described for the elements measured. The sample was mixed with the appropriate solution and then pumped via the manifold described in Various ref. 9312717 (As Bi Specimens were diluted 1 + 1 with H 2 0 and 9311 109 93JC1448 93/27 17 Hg Pb Sn) extended when samples were introduced by FI (Au Cd Cu Zn) 100 ml of urine at pH 1 mixed with 0.5 g of charcoal were boiled for 5 min cooled filtered and taken to pH 3.APDC was added and the chelates extracted into 125 ml of IBMK. The organic solution was evaporated the residue digested with HN0,-H20 and made up to 10 ml for analysis (Cd Co Cu Ni Pb) Usable lifetime of the slotted quartz tube was 93/27 18 9313086 9313206 Metal contents of milk from humans guinea pigs cows and horses were compared ICP-AES was used for the determination of reference values for a large number of elements in liver kidney lung milk hair and serum from normal adult subjects 9311 129 9312050JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 103 R Table 1 (continued) Technique; atomization; Element Matrix analyte form* Various ( 1 1 ) Biological materials M S;ICP;L Various (4) Semen seminal plasma AA;-;L Various ( 12) Milk Various (7) Nitric acid water Various (8) Milk MULTI-ELEMENT ANALYSIS Soft tissues Various ( 15) Urine blood faeces biological tissues A E;IC P;L AA;ETA;L AA;F air-C2H2;L A A; ETA; L A E;ICP; L AA;ETA;L AE;ICP;L PIX Ei-; S Various Kidney XRF;-;S Various (13) Liver Various Biological tissues Various (4) Kidney X R F;-$ Various (23) Serum milk hair biological AE;ICP;L tissues Various Biological tissues MS;ICP;-- Various ( 5 ) Biological tissues Various Biological tissues Various Biological tissues Various (6) Liver Various Brain Various (4) Liver Various ( 5 ) Kidney red cells plasma Various (4) Eye lens MS;ICP;L XRF;-;S LMMS;--;S MS;ICPL AE;ICP;L XRF;-;S A A;ETA;L A E;IC P;L AA;F;L AA;ETA;L Sample treatment/comments Reference Liquid samples were diluted in an FI system to 9312298 reduce the salt content to below 0.1% (in Japanese) Concentrations of Cd Pb and Zn in semen were similar to those in seminal plasma but Se levels were higher in semen compared with seminal plasma.Correlations were noted between semen parameters and Cd and Se concentrations (Cd Pb Se Zn) Differences in trace element composition were determined in milk samples from guinea pigs cattle horses and humans. See also 9311 129 examined to assess whether their contents would become contaminated. Only A1 was found to be added to the test solutions from these tubes (Al Co Cu Fe Mn Pb Zn) Closed microwave digestions with HNO and HNO + either HF H202 or HClO were evaluated.Best results were achieved with HNO,-H,O and with HN0,-HCIO (B Cd Cu Fe Mn P Pb Zn) 9313470 Plain evacuated blood collection tubes were 941434 941550 941603 Urine and blood samples were diluted 1 +9 with 0.1 YO Triton X-100 for measurement of Cd by AAS. Other elements were determined in urine faeces and tissues. Faeces were digested with HNO and analysed by ICP-AES tissues were dried and compressed into pellets for PIXE Thin sections of normal and cancerous tissue were examined by SR induced X-ray emission. Ratios between elements not absolute concentrations were measured obtained (in Chinese) techniques for localization of elements in tissue on trace elements in the kidney were investigated (Cu Hg Se Zn) (in Japanese) ICP-AES was used for the determination of reference values for a large number of elements in liver kidney lung milk hair and serum from normal adult subjects Analysis of human tissue specimens is discussed with reference to needs for measurements sample collection preparation and reporting of results.Analytical procedures are discussed and the importance of ICP-MS for multi-element analysis is emphasised digestion of liver lung spleen and kidney samples from 14 subjects (Ba Bi Th TI U ) Techniques for the localization of elements in tissue sections in toxicological studies were reviewed Normal levels of elements in 11 tissues of rat were determined Simple dissolution method with HNO and filtration to remove undigested lipid gave accurate results with a CRM (Ca Cu Fe Mn Mo Zn) A mapping spectrometer with resolution of <20 pm was developed and used for the investigation of a subject with brain calcification (Japanese) 44 specimens were analysed to provide normal concentrations of Cr Mn Ni and Pb Accumulation of As and interactions between As and other elements were investigated in rats fed As for up to 15 weeks (As Cd Cu Ni Pb) Cataractous and clear lenses were digested in acid.Concentrations of Ca Cu and Zn were increased while K was decreased in the abnormal samples (Ca Cu K Zn) Low LODs good precision and accuracy were This review compared SIMS analysis with other Effects of exposure to organomercury compounds A closed PTFE microwave system was used for 93JC994 9311 668 931 1 690 931171 1 9311 861 9312050 9312270 9312449 9312696 9312899 9313085 9313 168 9313290 931329 1 93/33 16104R Table 1 (continued) JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Element Matrix Various (7) Biological tissues Technique; atomization; analyte form* A A;ETA,L Various (4) Skin AA;ETA;L Sample treatrnentJcomments Reference An FI-HG system was used to separate the analytes from the matrix and trap the hydride vapour on a Pd-coated graphite platform. The method was applied for the measurement of Sn in several samples (As Bi Ge Sb Se Sn Te) Changes in the trace element composition of skin occurred after irradiation (Cd Cr Cu Zn) 9313964 941450 MULTI-ELEMENT ANALYSIS Bone and other hard tissues Various (21) Oyster shell AE;ICP; L Various (4) Dentine XRF;-;S Various Gallstones Various (14) Bone MULTI-ELEMENT ANALYSIS Hair nails Various (69) Cashmere wool Various (23) Serum milk hair biological tissues Various (6) Hair Various (12) Hair Various (10) Hair biological materials X R F;-; S M S;I C P;L MS;ICP;L AE;IC P; L AA;F;L XRF;-;S MS;ICPL MULTI-ELEMENT ANALYSIS Biological materials RMs Various Biological materials M S;IC P; L Various (38) Ear wax AE;IC P;L . .Various Biological materials 9 Various Biological materials A E; I C P; L Various Biological materials XRF;-;S Various Biological materials XR F;-;S MS;ICP;L Various Biological materials Various (8) Medicinal plants Various Biological materials MS;-;S X R F;-$ XRF;-;S AA; ETA$ AA;ETA;SI Trace elements CaCO and amino acids were measured in oyster shell Changes to the composition of dentine on the surface of teeth induced by brushing were examined by EDXRF and other techniques (Ca F Mg P) (in Japanese) Measurements were used to assist in the classification of stones (in Chinese) Vertebral bone samples were digested in a closed PTFE microwave system and analysed after addition of an internal standard using the semi- quantitative mode Oils were removed by rigorous washing and dissolved in HNOJ in a closed vessel microwave system.The calibration procedure was impractical for routine use. Only Ca and Mg concentrations correlated with yield of cashmere ICP-AES was used for the determination of reference values for a large number of elements in liver kidney lung milk hair and serum from normal adult subjects Better recoveries were obtained when samples were prepared by dry ashing than with an acid digestion procedure (Ca Cu Fe Mg Mn Zn) (in Chinese) Differences in trace element concentrations were seen between black and white hair between male and female subjects and with age Venetian fishermen other samples were analysed for a range of elements to investigate the technique Concentrations of A1 were measured in hair of 9311280 9311 71 3 9311742 9 312 3 04 9311 078 9 3 /20 50 9312149 9312738 9312966 Interferences associated with Na + were investigated and reduced by adjustments to the nebulizer flow rate Analysis of ear wax was proposed as a non-invasive technique for monitoring exposure to metals Procedures for sample preparation were described for a range of sample types and analytes and recommended methods were given fluid extraction prior to microwave digestion with HNO in closed containers analysis were described a quartz carrier for TXRF or nebulized for ICP-MS.With one element added for internal standardization results obtained with CRMs were reported to be good-to-satisfactory metal distributions to target organs storage and elimination in situations of environmental contamination Trace elements in medicines were dependent on the plant species from which they were prepared (Br Cu Fe Ni Pb Rb Sr Zn) (in Czech) The requirements advantages and limitations of solid and slurry analyses were presented. (Also given in 9312200) 9311047 9311 118 9311 140 Fats were removed from specimens by supercritical 93/c 1545 Advantages of TXRF for multi-element and surface After digestion with HNO specimens were dried on 93jC 1613 9311652 Invertebrates and fish were studied to determine 9311799 9311804 9311944JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) 105R Element Matrix Technique; atomization; analyte form* Sample treatment/comments Various Biological materials Various Biological materials Various Biological materials Various (4) Biological materials Various (10) Hair biological materials Various Biological materials Various ( 7 ) Biological materials Various (6) Biological materials Various Biological materials Various ( 15) Ginsengs Various ( 5 ) Biological RMs Various (16) Biological RMs Various (6) Biological materials Various Biological tissues MS;ICP;L MSi-i- M S;-;S AE;DC P;L M S; IC P;L M S;ICP;S AE;ICPL AE;ICP;S AE;ICP;L M S;I CP; L AA;F;L AA;ETA;L AA;ETA;L AEICPL AE;ICP;L MS;ICP;L Various Biological materials MS;ICP;S Dried samples were mixed in a tungsten ball-mill and the powder pressed into an XRF cup to form a 32 mm disc.The disc was placed into a laser ablation cell constructed for vaporization of specimen and transfer of the ions into the ICP the preparation of biological RMs four laboratories and the results compared with those given by several other techniques. Accuracy of solids analysis was influenced by the number of replicates and quality of the RM used for calibration (Cd Cu Pb Zn) This review describes the separation of organometallic compounds by either extraction techniques or by GC or HPLC with ICP-MS used for quantification Applications of stable isotopes as tracers in medicine and research were described Technique and applications of accelerator MS were reviewed Using a factorial design the optimum conditions for microwave digestion in an 80 ml vessel were investigated.The conditions studied were sample mass type and amount of acid microwave power and time. 0.25 g of powdered sample with 6 ml of HN03 + 3 ml of HCI at 90% power (600 W = maximum power) for 15 min were the preferred conditions (Ca Cu Fe Zn) Venetian fishermen other samples were analysed for a range of elements to investigate the technique Work with an LA device for sample introduction for ICP-MS and FANES was presented A commercial automated column preconcentration system using EDTrA-cellulose provided for 7-fold improvement in detection limits (Cr Cu Fe Mn Ni v Zn) An acid mixture with HN0,-HC10,-HCI-HF was used to digest samples by microwave heating in closed PTFE vessels.Residues were diluted and 100 pl aliquots taken for discrete nebulization into the flame (Ca Cu Fe Mg Mn Zn) Recent developments in equipment and applications of HPLC and GLC with ICP-AES or ICP-MS for detection were comprehensively reviewed Various ginsengs were digested with HN03-HC10 and the trace element composition determined (in Chinese) A series of candidate RMs were digested with HNO for trace element measurements by various techniques (Cd Cr Cu Pb Zn) A series of RMs were used to validate methods which were to be used for analysis of brain tissue Spectral interferences were considered and a procedure developed to separate analytes from interfering ions.An on-line column containing an ion-exchange resin with iminodiacetate groups was used in an FI system to retain analytes which were then eluted into the ICP with 3 mol I - ' HNO . Samples were initially digested with HNOJ and H20z (Cd Cu Mn Pb V Zn) Slurry of powdered specimen was transported by FI manifold to a reaction chamber within a microwave oven. HNOJ was added automatically the chamber sealed and the contents heated. This FI system was suitable for measurements using various atomic spectrometric devices Approaches to the measurement of trace elements in serum and other samples were reviewed (B Mo Sn Zn) Various Biological tissues blood A A; ETA;S Various (4) Biological materials AA;ETA;S Composition of six potential RMs was determined by Solid sampling analysis was used for quality control in Concentrations of A1 were measured in hair of AA;F air-C,H,;L LC and SFC as techniques for separation of metal species coupled with ICP-MS for detection were discussed in this review (As Cr Hg Pb Sn) Various (4) Serum biological materials MS;ICP;L Various ( 5 ) Biological materials M S;ICP;L Reference 931209 1 9312 189 9312 190 9312254 93/23 13 9312480 9312719 9312966 93/c3034 9313114 9313 143 93/32 19 9313535 9413 5 94/38 941577 941578 94/59 1 941592106R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Table 1 (continued) Element Matrix INDIRECT ANALYSIS Alkaloid Pharmaceuticals drugs Arginine Pharmaceuticals Cocaine Pharmaceuticals Thiocyanate Serum urine saliva Technique; atomization; analyte form* Sample treatment/comments AA;F;L AA;ETA;L AA;F;L AA;F;L Alkaloids (amylocaine papaverine and bromhexine HCI) were measured indirectly as complexes with BiI,- and CO(SCN),~- extracted from aqueous solution into 1,2-dichloroethane Methanolic 0.05% Nafion 117 was dried on tungsten wire coiled in a 3 mm disc.The coil was immersed in a Cu solution dried and placed into a graphite cup for ETA of the Cu. The coil was then immersed in the Cu solution to which arginine had been added. The difference in absorbance was proportional to the concentration of arginine and provided an indirect method for measurement of this amino acid Co(SCN),*- Fe(SCN)63- or Ni(SCN),*- were extracted in a continuous automated system for the indirect determination of the drug.BiI,- provided the best sensitivity Saliva and serum samples were deproteinized and urines were centrifuged. Addition of a Schiff base Cu [ 2-benzoylpyridine t hiosemicarbazone] formed a complex with thiocyanate which was extracted at pH 5.2-9.0 into isopentyl acetate. The organic layer was removed for determination of Cu Complexes formed between cocaine and Bi14- Reference 9313398 941230 9313920 9313963 *Hy indicates hydride and S L G and S1 signify solid liquid gaseous or elsewhere. slurry sample introduction respectively. Other abbreviatios are listed digestion of slurried samples. Carbonell et al. (93/2082) mixed the sample with a 1 + 1 mixture of HNO and H202 in an FI system.The solution was passed continuously through a PTFE coil in a microwave oven. Four minutes heating was sufficient to extract all Cu and Mn from the solid in all samples studied but digestion was not complete. After heating the digest was cooled and passed through an injection port from which an aliquot of the digest could be injected into a flame AA spectrometer. Determination of Cu and Mn in NIST SRM Tomato Leaves gave results that were in good agreement with certified values. In their method for the determination of Pb in biological materials by ETAAS Burguera and Burguera (94/284) passed samples slurried with 0.4% v/v Triton X-100 and mixed with 0.5 mol 1-' HCl-0.5 mol 1-' HNO through a long coil in a microwave oven to achieve digestion. Gases were extracted when passed through a gas diffusion cell connected to a vacuum pump.An aliquot of the effluent was automatically injected into a graphite furnace Pd modifier was added and the furnace programme initiated. The totally enclosed system gave low and reproducible blanks and results on blood and animal tissue CRMs gave good agreement with the certified values. However there were problems with botan- ical CRMs. Whereas Burguera and Burguera used continuous flow through the oven using a long coil to achieve sufficient time for digestion Gluodenis and Tyson (94/578) developed a stopped flow system for digestion of slurries with HNO in a microwave oven at pressures up to 400 lb in-2. The system was evaluated with cocoa powder and IAEA Horse Kidney CRM. Interesting though the developments in on-line digestion are for solid samples there seems to be little practical point in the added complexity.Samples need to be slurried and as Miller-Ihli in particular has demonstrated over many years excellent results can be obtained on biological samples by direct analysis of slurries by FAAS ETAAS and ICP-AES. Recent contributions from Miller-Ihli describe a systematic approach for establishing optimal conditions for slurry analysis by ETAAS in a wide range of materials (93/22OO) and a review of the technique comparing it with direct solid-sampling ETAAS (93/1944). Perhaps a more convincing application of on-line digestion in an FI system is for cases when prior digestion of liquids is necessary e.g.blood or urine for the determination of Hg by CVAAS or for the determination of As Sb Se etc. by HGAAS. This has been studied by Tsalev et al. (93/2717 93/2718). The sample was passed through a coil of PTFE tubing which together with a ballast-load coil was heated in a focused microwave oven. By winding the reaction coil so that it passed in and out of the microwave field reaction time was increased to 46 s with only 6.3 s effective heating time. Temperatures reached 50-90 "C. The most successful oxidation mixtures for use with this system were those containing bromate-bromide and peroxodisulfate. This approach was particularly successful for the determination of Bi and Hg in urine but unresolved problems were found for the determination of As Pb and Sn.Dissolution of samples by bomb digestion using microwave heating continues to attract attention. Mohd et al. (93/2719) developed a factorial design approach to optimize dissolution with respect to amount of sample type and amount of acid microwave power and time of dissolution. The results for Lobster Hepatopancreas CRM TORT-1 [National Research Council of Canada (NRCC)] and NIST SRM 1575 Pine Needles led to a procedure based on a 0.25 g sample digested with 6 ml of HCl + 6 ml of HNO + 3 ml of HF at 90% microwave power for 15 min. Many workers use dissolution with HNO alone but this does not completely oxidize the fats. Barnes et al. (93/C1545) examined the possibility of extracting fats by supercritical fluid extraction prior to micro- wave dissolution.Digestion with HNO alone was found by Mingorance et al. (94/603) to give low results for Fe when the Si02 content of the samples was high. Subsequent treatment with HF on a hot-plate overcame the problem. For materials with a high fat content (e.g. milk products) digestion with HN03-H202 or HN03-HC10 was advocated. Micro- sampling FA AS coupled with small volume microwave-assisted digestion allowed Kojima et al. (93/3143) to determine Ca,JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 107R Cu Fe Mg Mn and Zn in a number of CRMs. The sample was digested with HN0,-HC104-HC1-HF in a capped Teflon PFA vial placed inside a PTFE vessel containing 1 mol 1-' NaOH. After dilution of the digest loop1 portions were nebulized into the flame for determination of the elements.Small volume digestion was also used by Burguera et al. (93/3942) for preparation of biological samples for determi- nation of Cu Fe and Zn by FI-AAS. Inductively coupled plasma AES was applied by Krushevska et al. (93/2048) to determine residual carbon after digestion of biological materials. Concentrations were highest in microwave digestion in closed vessels (93/2049 93/C2999) but were reduced with increased pressure. A high-pressure digestion in a quartz vessel using HNO alone gave very low residual carbon as did more conventional approaches using dry ashing at 500 "C and wet digestion with HN0,-H2S0,-H202 (with hot-plate or focused microwave heating j. All approaches gave complete recovery for zinc in milk and the residual carbon did not affect the measurement by ICP-AES.Conoentional digestion need not be as time-consuming as is commonly imagined. For bovine liver Asp and Lund (93/3085) tried various hot-plate procedures and room temperature digestion. They recommended a simple procedure based on heating with HNO for 1-2 h followed by filtration of undis- solved material. Good results were obtained for Cd Cu Fe Mn Mo and Zn in bovine liver CRMs after determination by ICP-AES. The difficulty of getting Fe into solution was emphas- ized in a study by Beran (94/168) on biological RMs. Low results were obtained with wet digestion with dilute HNO ( 1 + 1) and after dry ashing and dissolution in dilute HNO (1 +2j. Best results were obtained after wet ashing with The results of an inter-laboratory study to evaluate direct solid sampling ETAAS were described by Schauenberg and Weigert (93/2190).Six biological RMs were analysed and the results compared with those obtained by other techniques such as FAAS ICP-AES ICP-MS and ETAAS. These workers concluded that the accuracy of the solid-sampling technique was influenced by the number of replicates measured and the type and quality of the RM used for calibration. Luecker et al. (93/2189) applied solid-sampling ETAAS to quality control in the production of animal tissue RMs. Some interesting applications of on-line preconcentration have been developed. Welz and his research group (93/C1524 93/2121 94/267) used dithiocarbamates with solid sorbent extraction followed by elution with organic solvents to achieve greater sensitivity. Thus Cd in urine was determined by FAAS after on-line extraction with NaDDC (93/C2154) and Cd and Cu were determined in digests of biological RMs using precon- centration by diethylammonium diethyldithiocarbamate col- lection on a sorbent and elution with methanol directly into the nebulizer of a flame AA spectrometer (94/267).A sampling frequency of 85 h-' was achieved. The same system could be used for enhancement by coprecipitation allowing increases in sensitivity of up to 50-fold. This allowed the determination of Cd Co and Ni in digests of plant and animal tissues by adding Fe and coprecipitating the trace elements with the iron@ jhex- ah ydroazepinium hexah ydroazepine- 1 -car bodi thioate complex (93/2121). The precipitate was dissolved in IBMK for determi- nation of the elements by FAAS.Detection limits were 0.15 1.3 and 1.5 pg 1-' for Cd Co and Ni respectively. Schramel et al. (93/3114) reported a more than 7-fold improvement in detection limit for determination by ICP-AES by application of a Knapp automated preconcentration system. Determin- ation of Hg by ICP-AES down to a concentration of 2 pg 1-' was made possible by an on-line FI preconcentration procedure described by Canada Rudner et al. (94/579). Samples were mixed on-line with the complexing reagent 1,5-bis(di-2-pyridyl- methy1ene)thiocarbonohydrazide and extracted into IBMK. The organic phase was separated mixed with SnCl in DMF and passed directly to the nebulizer. The precision of the HN03-HC104. method was 3.3% RSD at 250 pg 1-'.The method was applied to the determination of Hg in animal tissue CRMs with good results. A further interesting application of enzymes in separation has been explored by de la Calle-Guntinas et al. (94/585). Fructose-6-phosphate kinase selectively separates Sb"' from Sb". The enzyme was immobilized on controlled-pore glass and packed in a glass microcolumn. Antimony(II1) retained by the column was eluted with 3% v/v lactic acid and determined by ETAAS. Five-fold enrichment was achieved. A knowledge-based computer system for the selection of a method for dissolution of drugs prior to the determination of elements by AAS was developed by Penninckx et al. (94/374). Of the three type of decision-based software evaluated the most satisfactory was one developed with a hypertext language.1.3. Developments in Multi-element Analysis 1.3.1. Inductively coupled and direct current plasma atomic emission spectrometry The possibilities of ICP-AES in the analysis of clinical and biological materials is well-illustrated by a recent article by Caroli et al. (93/2050). This reviews the work of this Italian group in the establishment of reference values for hair kidney liver lungs milk and serum which has featured in previous Updates. Methods were simple exploiting the advantages of ICP-AES-a multi-element capacity a wide dynamic range and relative freedom from matrix interferences. Most of the work was involved in developing reliable contamination-free procedures for collecting samples and dissolution of solid samples. Developments in ultrasonic nebulization have allowed lower detection limits and recent improvements have been described at conferences. Shkolnik et al.(93/C1448) showed the improve- ments in stability and the reduction in memory effects of the new Varian ultrasonic nebulizer. Application to the analysis of urine was demonstrated. Brenner (93/C3000) applied an ultra- sonic nebulizer to the determination of A1 in serum without sample dilution allowing LODs of less than 1 pg 1-' to be attained. Aluminium can be satisfactorily determined in serum with conventional nebulization as was shown by Chappuis et al. (93/1058) who determined Al Cu and Zn in serum with a sequential spectrometer using the 396.15,324.75 and 213.86 nm lines respectively. Samples were diluted 1 +4 with a KC1 solution.Detection limits were 0.12 0.020 and 0.11 pmol 1-' for Al Cu and Zn respectively. Zhang et al. (94/402) deter- mined 24 elements in serum by ICP-AES with conventional nebulization and HG. The serum was digested with acid and diluted 5-fold for measurement. Matrix-matched standards were used. Lopez-Artiguez et al. (93/3206 94/601) determined Cd Co Cu Ni and Pb in urine by ICP-AES after extracting their APDC complexes into IBMK evaporating to dryness and digesting the residue with HN03-H202. Detection limits ranged from 3.5 pg I-' (Cd) to 6.3 pg 1-' (Ni). Extraction of Ni into butan-1-01 with the reagent 1,5-bis(di-2-pyridylmethyl- ene) thiocarbonohydrazide allowed Vereda Alonso et al. (93/1034) to improve the sensitivity sufficiently for the determi- nation of Ni in a range of biological and environmental CRMs after bomb digestion with microwave heating.A ratio of the volume of aqueous to organic phase of up to 8 + 1 could be used; because of the solubility of butan-1-01 in water the actual phase ratio after shaking was about 32+ 1. The LOD thus improved to 0.2 pg I-' making the method suitable for the determination of Ni in urine and digests of tissue samples. Comparison of the concentrations of Ca K Mg Na and P in milk of guinea pigs cattle horses and man was made by Anderson (93/1129 j after measurement by ICP-AES. Calcium concentrations decreased in the order guinea pigs > cattle >108 R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 horses > humans each about half the concentration of its predecessor in the series.Potassium was the most abundant element in the milk of all except the guinea pig. 1.3.2. Inductively-coupled plasma mass spectrometry and other mass spectrometric techniques An excellent introduction to the problems of analysis of trace elements in biological samples by ICP-MS is given in the published version of a lecture by Vandecasteele et al. (94/591). This Belgian group has done pioneering work on the appli- cation of ICP-MS to the determination of trace and ultra- trace elements in serum particularly with the objective of establishing reliable reference ranges for the more difficult elements and to characterize the second-generation Versieck serum RM. To avoid clogging the fine orifices in the spec- trometer samples were diluted 1 + 4 with 0.14 mol 1-' HN03.Suppression of signal by matrix components was overcome by the use of an internal standard chosen to have a similar mass to the analyte. For most elements careful choice of the analyte isotope to be measured allowed isobaric and polyatomic interferences to be overcome. With these steps accurate results were obtained on serum RMs and on B and Li in food and bovine liver RMs analysed after microwave-heated pressure digestion with HN03. For readers of Japanese Haraguchi (93/2300) has surveyed the problems of the determination of trace elements in serum particularly by ICP-MS and has emphasized the difference between reference values in the literature and in use by different hospitals and research insti- tutes. He recommended that in Japan this problem should be examined and solved by a working committee. There remain many problems due to interferences in ICP-MS particularly from polyatomic species in the determi- nation of As and Se.Goosens et al. (94/613) used anion- exchange on a Dowex 1x8 column in nitrate form to retain chloride from sea-water and urine samples. For serum the column in acetate form was preferable. The technique was also suitable for the removal of interferences from S in the determi- nation of Cu and Zn in serum (J. Anal. At. Spectrum. 1992 7 1167). Hydride generation can also be used to separate the As from chloride as Walcerz et al. (93/C1351) demonstrated. This gave a 10-fold increase in sensitivity as well as eradicating the 40Ar35C1 signal. Kershisnik et al. (93/2931) found that the signals for 16035Cl and 40Ar35C1 were proportional over a wide range of chloride concentrations and used this as a basis for correcting the "As line measurement.Accurate results for the determination of As in urine were demonstrated by comparison of results with those obtained by ETAAS. A further alternative approach is to reduce the polyatomic interferences by introduc- tion of other gases into the plasma. Hill et al. (93/1022) carried out a simplex optimization of N addition to an Ar plasma in the removal of chloride-based interferences. While addition of N to the auxiliary gas had little effect addition to the coolant or nebulizer gas was successful in removing the ArC1' inter- ference. Best results were obtained when 4.5% N2 was added to the nebulizer gas.The system was tested with a range of CRMs including dogfish liver. Addition of methane to the nebulizer gas gave similar effects (J. Anal. At. Spectrom. 1992 7 1157). Safety measures to handle a combustible gas intro- duced extra complications compared with the use of N2 but LODs were better for As Se and V. Carbon compounds enhance the signal for As and Se in ICP-MS. Wallace (93/C1508) examined this effect in detail in particular with reference to blood and urine. For other elements removal of interferences by on-line pre- treatment of the samples has been studied. Pretty et al. (93/2090) designed an on-line ASV flow cell to deposit Cd and Cu from diluted urine onto a mercury-coated carbon electrode. The elements were then stripped into 0.1 mol I-' HN03.Flow was then initiated to pump the solution into the ICP mass spectrometer. This is an extreme example of overkill in solving the interference problem of one complicated technique by adding on another complicated technique in order to carry out determinations which are more easily carried out by less expensive techniques. A far more practical system for eliminat- ing interferences was developed by Ebdon et al. (94/577). Trace elements were isolated on a chelating microcolumn (2 cm) filled with an iminodiacetate-based resin. Matrix components passed straight through. The column was set up in an FI system which allowed the analytes to be eluted from the column into the ICP mass spectrometer. The system was tested on a range of food and biological CRMs after pressure digestion with HN03-H202 and buffering to pH 5.3 with ammonium acetate buffer.The method gave acceptable results for Cd Cu Pb V and Zn but was unsuccessful for Cr despite several modifications. For the CRM TORT-1 (Lobster Hepatopancreas) the Cu and Zn concentrations were high enough to exceed the capacity of the column leading to low results. Correct results were obtained when the sample was diluted further. Multi-element applications of ICP-MS continue to be demon- strated. Kushida et al. (93/2298) determined 11 elements in total parenteral nutrition fluids and elemental diets by ICP-MS. Because of the high solids concentration samples were introduced by FI. The determination of Al Cu Cd Fe Mg Mn and Zn in digests of human tissues taken at autopsy was described by Lyon and Fell (93/2270) and the results were compared with results obtained by FAAS or ETAAS.Using Bland and Altman plots significant bias was evident only for Fe and Zn. In elderly subjects increased Fe and Zn concen- trations were found in the liver but Se concentrations in the tissues (measured by molecular fluorescence spectrometry) were slightly lower than in younger controls in agreement with a difference in plasma Se concentrations found. Tissue samples from patients on renal dialysis showed increased A1 and Cr concentrations. Shiraishi and McInroy (93/2449) determined Ba Bi TI Th and U in the liver lung spleen and kidney of 14 American males by ICP-MS. Results on NIST SRMs Bovine Liver and Tomato Leaves gave relatively good agree- ment with certified values.In a further study (93/2304) these workers determined using internal standardization 14 elements in the vertebrae of the same men. Gelinas et al. (93/2899) determined a range of elements in rat tissues (bone brain erythrocyte heart kidney cortex and medulla liver lung muscle and plasma) by ICP-MS. The correlation between elements and tissues was elucidated with the help of principal components analysis. Cerebrospinal fluid from patients with various disorders was analysed for 20 elements by Gooddy et al. (93/2406 93/3774) after prior digestion of the sample. Hair samples from fishermen in the region around Venice Italy were analysed for potentially toxic elements by Bortoli et al. (93/2966) using ICP-MS. The technique was validated by analysing some BCR CRMs and by comparison of As Cu Pb and Zn results with those obtained by AAS.Three reports detail application of laser ablation in analysis of biological samples by ICP-MS. Hoffmann et al. (93/C3034) used a commercial system and optimized the conditions for best ablation. Similar studies were carried out by Denoyer (J. Anal. At. Spectrom. 1992,7 1187) and Ward et al. (93/2091). Denoyer used a SCIEX laser sampler but Ward et al. built their own system with a ruby laser. The SRMs evaluated were dried and pressed into discs. By using a repetition rate of 1 laser pulse per second Ward et al. attained a steady response for optimization studies. Calibration was made with Bowen's Kale RM and results were compared with and without internal standardization.The method as so far developed was described as semi-quantitative; results for 26 elements were mainly within a factor of 2 of the certified values and many results were much closer. The ease of sample preparation and the reduction of some polyatomic interferences as a result of the 'dry' plasma were seen as advantages. Results in Denoyer's study gave similar accuracy but a wider range of SRMs were coveredJOURNAL O F ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 109 R including NIST SRM Oyster Tissue. Calibration was made with a US Geological Survey Soil CRM. Internal standardiz- ation improved accuracy to within 20-40%. Precision was in the range 8-14% RSD. The potential of LC and SFC when combined with ICP-MS for speciation of trace elements is well illustrated in an overview by Vela and Caruso (94/592). With SFC it is possible to separate thermally labile non-volatile and high relative mol- ecular mass compounds not easily separated by GC and with the advantage of shorter analysis times than with LC.Interfacing to ICP-MS is more elaborate than with LC. Application to biological samples is covered also in a review by Lespes et al. (93/2254) in French. This deals with GC separation in addition to LC separation. Details of recent publications on particular elements are covered in section 1.9 but the subjects covered illustrate the potential of the combi- nation of LC with ICP-MS; speciation of iodoamino acids in bovine thyroglobulin (94/3435) As in urine (93/3224) Hg in dogfish muscle and contact lens solutions (94/575) and Fe in liver heart and hepatocyte cultures (93/2322). Huang and Jiang (94/575) used ultrasonic nebulization in their study on Hg.This gave LODs 10-fold better than with a conventional nebulizer but was comparable to LC-cold vapour generation-ICP-MS. Campbell et al. (93/1OO5) have warned that the signal for Hg in ICP-MS is dependent on the chemical species present. They found lower results for total Hg in a candidate BCR CRM Cod Muscle when direct calibration with internal standardization was used compared with results obtained by ICP-MS with standard additions calibration and by CVAAS. In all cases the sample was digested with HN03 in a microwave-heated digestion bomb. This apparently is insufficient to decompose methylmercury and they believed that because of the high ionization potential of Hg ionization was relatively low (about 38%) and was affected by the species of Hg in the plasma.Stable isotopes have proved particularly useful in studies of human metabolism and determination by ICP-MS has further promoted this science. The absorption of non-haem Fe in women was studied by Barrett et al. (93/2932) using the stable isotopes 57Fe and 58Fe and determination by ICP-MS. Absorption ranged from 10 to 34% and was related to the Fe stores of the subject. Hansen et al. (93/2550) used ',Fe and determination by FAB-MS to measure the bioavailability of Fe in pharmaceutical preparations. Studies on Zn are of particular relevance but the determination of the isotopes by ICP-MS has particular problems. Two recent publications offer improvements on the original method by Serfass et al.(Anal. Chim. Acta 1986 188 73). Patterson et al. (91/2132) modified the matrix of the final solution from HC1 to HN03 to avoid interference by C1 in the detection of 70Zn. The same problem was solved by Amarisiriwardena et al. (93/2059) using extraction with APDC into CCl,. Back-extraction however gave a small C1 signal from dissolved CCl so that they preferred to evaporate to dryness and re-dissolve the residue in HN03. The method was applied to blood urine faeces and diet. In a study on over 120 human subjects using FAB-MS and stable isotopes Fennessey er al. (93/2504) found an average absorption for Zn of 73% and an average time for passage of Zn through the gastro-intestinal tract of 4.7 d. Methods for the determination of Se stable isotopes developed by Buckley et al. (93/2917) used HG and ICP-MS for three enriched isotopes 76Se 77Se and 82Se and a reference isotope 78Se.For studies on the genetically-inherited Wilson's disease Lyon et al. (93/C1062 93/C1338) used 65Cu and measurements by ICP-MS to study the oral uptake of Cu. Differences were shown between normal subjects and patients with the disease as a result of which the technique was found to be useful in the studies of kindred within affected families. Dale et al. (93/C1339) compared ICP-MS and TIMS for measuring absorption of 204Pb applied to the skin. Good agreement was found between the techniques in the analysis of sweat and urine. The isotopic composition of natural Pb depends on the geological age of the parent ore.This fact has allowed Delves (93/C3041) to ascertain the source of Pb exposure from the isotope ratios in body fluids and tissues. In general the 206Pb:207Pb ratio in body tissues in the UK is 1.13+0.01 but exposure to Pb in drinking water in parts of Scotland raises the ratio to 1.18; Pb from soils in villages in Derbyshire increases it to 1.17 and Pb from exhaust fumes in inner cities reduces it to 1.07. Applications of ICP-MS to single element determinations in body fluids and tissues include Ge (93/2302) Hg (93/2426) I (93/2301) Li (93/2296 93/3771) Mo (93/2355) Ni (94/565) Pb (93/3777) Pt (93/2297 93/3770) REEs (93/2303) and Th (93/2235). These are dealt with in more detail in section 1.9. The current status of accelerator mass spectrometry including its application to medicine and biology was reviewed by Imamura et al.(93/2480). The application of the technique to measure absorption of A1 in humans using the isotope 26A1 was demonstrated by Barker et al. (93/2537). Absorption of A1 in the gastrointestinal tract was estimated at 1 %. Preparation of volatile compounds of elements allows deter- mination by GC-MS. Aggarwal et al. (93/2321) compared various reagents for the production of volatile Se compounds in the determination of Se in urine. The best was 4-trifluoromethyl- 1,2-phenylenediamine. Using 76Se as internal standard in isotope dilution precisions of 1-7% RSD were attained at the 10 ng level. Accuracy was demonstrated by determination of Se in the NIST SRM Freeze-dried Urine.For the determination of Co in urine (93/2423) Aggarwal et al. used lithium bis( trifluoroethy1)dithiocarbamate as a chelating agent with 62Ni as an internal standard producing a method capable of measuring down to 1 pg 1-' and showing good agreement in results when compared with ETAAS. The reagent sodium bis( trifluoroethy1)dithiocarbamate was used by Soltani-Neshan et al. (93/3776) to form Mo chelates to quantify Mo isotope ratios by GC-MS for availability studies. The LOD was 50 ng. Reaction of Pb at room temperature with sodium tetraethylborate was used by Feldman et al. (93/2424) to determine Pb in water by isotope dilution GC-MS. The LOD was 0.3 pg 1 - I and precisions were 4.2% RSD within batch and 8.7% RSD between batch over the concentration range 20-50 pg 1- '.The method was considered applicable also to biological samples. 1.3.3. X-ruypuorescence spectrometry The estimation of body burden of Pb by in uiuo measurement of lead in bone by XRF has aroused much interest (93/3897 98/3896,93/1860,93/3874). Chettle et al. (93/1860) re-measured tibia Pb concentrations in a group of men that they had studied 5 years previously. Over the 5 years improvements in technique had been made which led to better precision. Results confirmed the relationship between tibia Pb concentration and cumulative blood Pb concentration. Most workers in this field irradiate with a '"Cd source and measure back-scattered K-radiation (93/3896) which gives a lower effective dose. Todd et al. (93/1769) measured the dose at several points on the leg with systems at two research centres finding general agreement in dose levels.Slatkin et al. (93/3874) however calculated the effective dose when using L-radiation and reported that the doses were previously overestimated by a factor of about 2. The usefulness of the L-line for bone Pb estimation was critically assessed by Priess and Tariq (93/1766). Instruments designed especially for clinical applications have been built. Fukumoto et al. (93/3168) developed an XRF element-mapping spectrometer for biological samples The spatial resolution was >20 pm and two large area Si(Li) detectors placed close to the sample gave good sensitivity. The instrument was used to study a slice of brain taken at autopsy from a patient with brain calcification. An automated XRF system for medical applications was described by110R JOURNAL O F ANAL,YTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Kaufman et a!. (93/2873). Using stable isotopes applications such as measurement of extracellular fluid volume red cell volume and glomerular filtration rate were developed. The application of radioisotope-excited XRF to the determi- nation of trace elements in blood samples with minimum pre- treatment was described by Gresits et al. (93/1653). A non- radioactive method of measuring blood flow was developed by Mori et al. (93/3818). Microspheres loaded with heavy elements were monitored by WDXRF or SRXRF and used to measure regional blood flow in the heart and other organs. Total reflection XRF offers the advantage of high sensitivity giving pg detection limits for most elements (93/C1613). Savage and Haswell (93/C1615) used microwave heating to dry ash biological samples such as serum and urine directly onto the quartz reflectors.For the volatile elements As Hg and Se chemical modifiers were added to allow higher ashing tempera- tures in order to reduce scattered background radiation. The use of a single element as internal standard to allow multi- element analysis of biological CRMs by TXRF and ICP-MS was described by Giinther et al. (93/1652). The results by TXRF were classed as good to satisfactory whereas ICP-MS results were only within an order of magnitude of the certi- fied value. Matrix effects in the determination of 13 elements in animal liver by XRF were corrected by using scattered radiation as internal standard in a method developed by Li et al.(93/1691). The Rh Ka Compton scattered radiation was used for Br Cu Mo Rb and Zn; scattered background at 0.1876nm for Ca Fe and Mn; and the Rh La line Rayleigh scattered radiation for K Mg Na P and S. 1.3.4. Other multi-element techniques and studies Fernando et al. (93/C1467) developed a continuum source AA spectrometer with photodiode array detector and applied it to the simultaneous determination of Ca and Cd in urine with Bi as an internal standard. The LOD of the system was claimed to be better than previous continuum source instruments such that the LOD for Cd (0.01 pg 1 - I ) was the same as that obtainable with a line source. A weak absorption line (227.5 nm) was selected for Ca to measure the relatively high concentrations present in urine.Direct simultaneous determi- nation of Cr Ni Mn and Pb in blood was achieved by Hirano et al. (93/3939) using a Hitachi multi-element AA spectrometer. Interference was minimized by rapid heating platform atomiz- ation and chemical modification with Pd. Ammonium dihydro- gen phosphate was used as modifier by Imai et al. (93/1134) in the simultaneous determination of Cd and Pb in blood by ETAAS. Mean normal concentrations of Cd and Pb in the serum of normal subjects were found to be 0.28k0.11 and 3.3f 1.0 pg 1-' respectively. A method for determining the concentrations of Ca K Mg and Na in human platelets was outlined by Touyz and Milne (93/1197). After isolation the platelets were repeatedly washed and then lysed.Calcium and Mg in the lysate were determined by FAAS and K and Na by FAES. Mean concentrations measured for Ca K Mg and Na were 1.8 k0.5 4.5 & 1.5 2.3 f 0.6 and 1.5 f 0.6 pmol per 1 O6 cells respectively. Normal concentrations of Cr Mn Ni and Pb in human liver were established by Bona et al. (93/3290) using ETAAS after acid digestion. Samples taken at autopsy from 44 cases of sudden traumatic death gave mean concentrations of 2.49 5.08 1.81 and 4.43 pg g-' for Cr Mn Ni and Pb respectively. Positive correlations were found between Cr and Mn concen- trations and Cr and Ni concentrations. Cataractous human eye lenses were found by Gordiano et al. (93/3316) to have significantly higher Ca Cu and Zn concen- trations and lower K concentrations than normal healthy lenses.Samples were acid digested and the elements determined by FAAS and ETAAS. Using AAS for measurement Noack-Fueller et al. (93/3470) studied the Cd Pb Se and Zn concentrations in the semen and seminal plasma of men not occupationally exposed to those elements. Whereas Cd Pb and Zn concentrations were not significantly different in semen and seminal plasma Se concen- trations were significantly higher in semen than in seminal plasma. A significant positive correlation was found between sperm concentrations and semen selenium concentrations. Studies on the transport storage and elimination of the elements Al Ti and V using hamsters as models showed that V was rapidly excreted in urine with no apparent storage Ti was not excreted in urine but stored in kidney liver and spleen and A1 was excreted in urine with a small amount stored in the liver and spleen (93/3706).1.3.5. Imaging techniques Two reviews have appeared. The application of microprobe analysis to toxicology using electrons X-rays protons ions or a laser beam as probes was reviewed by Hoehling et al. (93/2696). Linton et al. (93/1711) compared SIMS with other microprobe techniques for imaging. Advantages of SIMS were said to be high sensitivity high depth resolution isotope specificity and possibilities for 3-dimensional imaging. Current limitations of difficulties in quantification and lateral resolution were likely to be overcome by recent developments. Imaging techniques have led to important discoveries in human disease. Using LMMS Good et al.(93/2919) examined melanin-containing neurons of the substantiu nigra in patients with Parkinson's disease. Aluminium and Fe were found to significantly accumulate in the patients compared with controls and these elements were believed to account for the selective degeneration of these neurons in Parkinson's disease. Homma et al. (93/2864) using SRXRF imaging found that concen- trations of Cu Se and Zn in kidney tumour tissue were lower than in adjacent healthy tissue. Copper and Zn concentrations seemed to be correlated in both healthy and tumour tissue; this they ascribed to the metalloenzyme Cu-Zn superoxide dismutase. In a further study on healthy kidneys (93/1714) Cu Se and Zn concentrations were found to be higher in the cortex than in the medulla. Mercury was found to accumulate more in the cortex than in the medulla in rats exposed to organo-mercury (93/1861) and its concentration was found to be highly correlated with the Cu Se and Zn concentrations.The detection of thyroid exchangeable I by SIMS was studied by Briancon et al. (93/2292). Two radioactive isotopes "'I and 1291 were tested. For in uivo animal studies injection of '''1 gave no detectable SIMS signal but 1291 gave suitable measure- ments on the thyroid. For human studies this was unsuitable because of its long half-life. Human thyroid tissue was incu- bated in v i m with 12'1 to detect exchangeable I. Chassard-Bouchard et al. (93/1799 93/2614) described the application of image processing by SIMS and EPMA to ecotoxicology. In trout exposed to A1 from acid rain A1 was found to accumulate as the phosphate in the gill and kidney a process which is well known. However high intracellular A1 concentrations were found in brain heart and bone and nervous tissue destruction was observed where there were high deposits of A1 (93/1799).In marine organisms Al rare earth elements (La Tm) and radionuclides (U Pu and Am) were shown to accumulate in the digestive gland and the exoskeleton. Application of LMMS to microbiology was described by Seydel et al. (93/2434). Information on Na:K ratios within bacteria was considered to be of particular relevance. 1.4. Developments in Single Element Techniques The use of a graphite probe in ETAAS offers advantages of reduction in interferences and appears to offer advantages in the analysis of body fluids as Ajayi et al. (93/1016) demon- strated.Atomization temperatures of 2400-2750 "C were used to minimize interferences. The elements Cd Cr Co Mn NiJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 l l l R and Pb were determined directly in urine RMs and Cd and Pb in a blood RM with good agreement with assigned concen- trations. The disadvantage of probe atomization is a reduction in sensitivity compared with wall or platform atomization and as a result Ajayi et al. found poorer precision at low levels making the methods only really suitable for the higher concen- trations found in occupational exposure. A group at the University of Oviedo in Spain also examined the suitability of probe atomization for clinical fluids in a collaborative project with Unicam Analytical Systems. The advantages of probe atomization for interference-free determination of Cd (93/2801) and Pb (94/583) in urine were confirmed.For Pb using either wall or platform atomization graphs of aqueous calibration and standard additions to a urine sample were clearly not parallel but they were when probe atomization was used. For Cd recovery seemed to depend on atomization temperature and contrary to the findings of Ajayi et al. (93/1016) this group found that the best recovery was achieved at an atomiz- ation temperature of 2050°C. Limits of detection for both Cd and Pb were 0.3 pg 1-'. Accuracy was demonstrated by com- parison with an alternative ETAAS method for Pb and for Cd by comparison with results in the Trace Elements Quality Assessment Scheme.However for the determination of A1 in waters dialysis fluids and serum (93/1025) platform atomiz- ation was preferred to probe atomization. Probe atomization gave poorer LODs and there were practical difficulties with serum in eliminating carbonaceous residues. Xu et al. (93/3086) found that by using FI sample introduc- tion the lifetime of the slotted quartz tube in FAAS could be improved by a factor of 5-6 when aggressive samples such as urine were introduced. For a range of elements enhancement of sensitivity by a factor of 3-5.5 compared with conventional nebulization was achieved with precision in the range 1-2% RSD. For Cd Cu and Pb in urine recoveries in the range 100-102°h were found. With the object of obtaining sensitivity sufficient for the determination of V in serum and blood Sjostrom et al.(94/555) improved laser-excited atomic fluorescence spectrometry with a side-heated integrated contact graphite tube furnace for atom- ization. Double resonance excitation in the visible region was used and detection was in the UV region with a solar-blind photomultiplier. This improved the LOD from a previously published value of 1.7 ng-10 pg unfortunately limited by con- tamination in the graphite material. This made further examin- ation of the concentrations in real samples impractical. Without contamination it was estimated that the LOD would have been 2-3 pg. There have been interesting developments in thermospray nebulizers. Larsen and Blais (93/3240) designed one that would easily fit on a conventional nebulizer in a flame AA spec- trometer. Both the quartz sample introduction line and the air supplying the nebulizer were heated in order to keep the nebulizer warm thus preventing loss of heat as the superheated fluid flowed through it.With FI sample introduction LODs for Cd Cu and Pb were 1.9,8.5 and 27 ng respectively 6-7-fold better than that achievable with normal FI-FAAS. An appli- cation with the thermospray nebulizer as a direct interface for HPLC separation of Cd-metallothioneins was demonstrated. In a further development High et al. (93/2897) described a thermospray micro-atomizer particularly suited as an HPLC detector. Previous designs had used the organic solvent from the column as the fuel but in this design H was the fuel and 0 the oxidant giving it the versatility to be used with aqueous mobile phases.A T-tube in the light path increased the residence time of the combustion products in the light beam. The LOD for the system was 27-fold lower than that obtained with the version described above using a conventional flame. The disadvantage of both systems was devitrification of the quartz components by sodium. Modifications to the materials used were planned. An indirect method for the determination of thiocyanate was described by Chatteraj and Das (93/3963). Reaction with the complex of Cu with 2-benzoylpyridine thiosemicarbazone gave a complex ion-pair which was extracted into isopentyl acetate and Cu was determined in the solvent phase by FAAS. The method said to be free from most interferences was applied to deproteinized saliva and serum and to urine. 1.5.Reference Materials and Quality Assessment The South African quality assessment scheme for blood Cd and Pb run by the National Centre for Occupational Health in Johannesburg was described by Rollin and Theodorou (93/C989). The objective of this scheme set up in 1979 was principally to assess the accuracy and reliability of Pb determi- nation in local laboratories. Good performance in this scheme has become a requirement for the accreditation of laboratories measuring blood Pb in terms of the South African lead exposure regulations. Vocke et al. (93/C3016) certified a new certijed reference muteriul NIST SRM Lead in Blood (955a) using isotope dilution ICP-MS. The new SRM was seen to have particular relevance in view of the increase in screening of blood Pb concentrations of children in the USA.A new candidate RM from NIST for marine biology pilot whale liver tissue was analysed for 39 trace elements and methylmercury using instru- mental NAA voltammetry and CVAAS (94/36). New Czech candidate RMs bovine muscle bovine kidney bovine blood rye flour and wheat flour were analysed for Cd Cu Cr Pb and Zn by ETAAS ICP-AES and square-wave voltammetry following pressure digestion with HNO (94/35). Existing CRMs were also analysed to ensure the accuracy of the procedure. Buckley and Ihnat (93/3544) determined Cu Mo and Se in ten new RMs from Canada including bovine liver powder. Copper and Mo were determined by ID-ICP-MS using measurement of the ratios 65Cu:63Cu and 97Mo:1mM~ after spiking with 65Cu and 97Mo and digestion with HNO,.For Se the sample was spiked with 82Se and after digestion Se was separated as the hydride by reaction with NaBH for measurement of the 82Se:78Se ratio by ICP-MS. Comparison of results with those from other analytical procedures indicated no significant bias. Lithium in two BCR candidate lyophilized serum CRMs was determined by Lamberty and De Bievre (93/3448) using ID-TIMS. Values obtained 0.517k 0.006 and 0.987+0.014 mmol 1-1 compared favourably with the values proposed for certification. The subject of reference methods in clinical chemistry was discussed in two publications. Buettner (93/2174) reviewed the importance of reference methods in improving the accuracy of routine methods and in establishing world-wide comparability of methods in clinical chemistry.Colinet from the EC Community Bureau of Reference (93/2175) described an inter- laboratory study involving six European laboratories developing a reference method for progesterone in serum using ID-MS. Although trace elements were not covered in these publications there is no doubt that this subject will appear in the future. 1.6. Hair Analysis Studies on the relutionship between trace element concentrations in hair and clinical condition continue to reveal snippets of information but fail to offer a convincing reason for hair analysis. A study of the Ca Fe and Zn concentrations in the hair of athletes by Qian et al. (93/2009) showed that changes in Fe concentration were related to exercise and this was seen as a further indication of sport being one of the causes of Fe deficiency in athletes.Measurements were made by SRXRF at 1.5 mm intervals along the length of the hair. Yaman and Kokcam (93/C1637) found that epileptic patients had higher Mg and lower Zn concentrations in the hair than controls. Comparison of trace element concentrations in the hair of people served by two different water supplies (93/2747) showed112R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 that although the water concentrations of Cu and Sr differed by factors of 10 and 240 respectively only for Sr was there an indication of an increase in the hair Sr concentration (mean values for two groups were 10.0 and 16.8 pg g- ’ respectively). The mean hair Cu concentration in the area with the higher Cu concentration in the water was actually lower (8.2 com- pared with 10.0 pg g-’).Measurements were made by XRF. A study by Fuse (94/498) using determination by ICP-AES of 21 elements in the hair of patients with atopic dermatitis showed no significant difference in concentration from controls. However the ratios Ca:Pb Zn:Cu Zn:Mn Zn:Pb and Zn:Cd were found to be higher in the patient group than in the control group. An extensive study by Watanabe et al. (93/2738) using XRF showed that factors such as sex age and hair colour were important. Fluorine concentrations were higher in males than in females and some elements increased with age e.g. concentrations of F in females. Eight elements showed higher concentrations in black hair than in white hair. A study from the same group on elderly patients with dementia (93/1800) similarly showed an increase in hair F concentration with age corresponding to an increase in serum F concen- tration but the A1 concentration in hair decreased. High Zn concentrations were found in the hair of the Asmat population of Indonesia in a study by Calliari et ul.(93/2817) using EDXRF. Most of the methods in this review year contain little that is novel but there has been some development in solid sampling. Koons (93/C1437) used ETV of segments of hair with detection by AAS or ICP-MS. These techniques were used in forensic science to distinguish between chronic and acute exposure in arsenic poisoning and as a multi-element ‘fingerprint’ to charac- terize hairs found at the scene of a crime. Liu et al.(93/2171) determined Cr in hair by partial digestion with HNO and addition of a surfactant to form a slurry of the residue which was injected onto an La-coated platform in a graphite furnace for measurements by ETAAS. Chen and Huang (93/2149) found that dry ashing at 500°C gave better results for the determination of Ca Cu Fe Mg Mn and Zn in hair by FAAS than wet-ashing with HN03-HC10,. Other tech- niques that have appeared include the determination of As in hair by HG-ICP-AES (93/3262) Hg by non-dispersive AFS after reduction with SnC12( 93/3134) and Ge by HG-AFS (93/2 1 5 1 ). 1.7. Marine Biology The active ingredient of one of the algicides used in the pens offarmed salmon is based on CuO. Peterson et al.(93/1102) determined Cu in the dorsal muscle and liver of salmon in treated and untreated pens by XRF and AAS. No statistical difference was found in Cu concentrations between the two groups. With increasing size of fish the Cu concentration increased in the liver and decreased in the dorsal muscle. The mineral and trace element composition of oyster shells was studied by Zhao et al. (93/1280). The CaC0 content determined by EDTA titration ranged from 88.7 to 96.1%. The other elements were determined semiquantitatively by The concentrations of Cd in various types of cephalopod mussels from the Ionian Sea off Sicily were measured by Cicero et al. (94/184) using ETAAS with Zeeman background correc- tion. Concentrations measured (39-1 37 pg kg-’) indicated that the dietary intake of Cd from this source was acceptable.1.8. Drugs and Pharmaceuticals The lack of requirement for detailed testing for metal impurities in pharmaceutical products is surprising and helps to explain the general lack of interest in the measurement of trace elements in pharmaceutical preparations. Steele and Petty (93/C1438) described the prescribed test for heavy metals in the US Pliar-rmcopueia; this irivolves detection of the precipitation of metal sulfides by H2S. They developed a test based on ICP- ICP-AES. AES which required a much smaller amount of sample was less susceptible to interferences and provided quantitative information on elements such as Be and Cr which would not show up with the sulfide test. Johannsen et al. (93/3775) examined the elemental profile of ‘pharmaceutical’ tablets especially those sold as health supplements.Their results obtained by ICP-MS showed that some contained half the stated amount of element (e.g. Se) and some contained elements which were not listed such as Al Cd Hg Pb and Sr. Procedures based on ETAAS for the determination of A1 in pharmaceutical products were described by Ericson (93/3156). Great attention was paid to minimization of contamination in preparation of reagents and samples. In order to quantify the amount of ink used in printing the company name on a drug Dunn et al. (93/C1439) used the measurement of Fe by ICP- AES. The ink used was based on an iron oxide pigment. All the printing from one tablet was scraped off and dissolved in a HN03-HF mixture. A blank was prepared by scraping off a similar amount of material from an unprinted surface of the same tablet.An extensive study of Chinese drugs by Mossbauer spec- troscopy XRD and AAS was reported by Li (93/4021). The results allowed a classification on the basis of the inorganic components. Yao et al. (93/3535) determined 15 elements in ginsengs by ETAAS and FAAS. Hydride generation ICP-AES was used by Kim et al. (94/179) to determine Ge in ginseng. Wet digestion with HN0,-HC104-H2S04 gave complete digestion without loss of Ge. Interelement interferences were overcome by extraction of Ge from 9 mol 1-’ HCl into CC14 from which it was back-extracted into water. Cadmium Pb and Hg concentrations in tobacco were deter- mined by Pesch et al. (93/3109) using solid-sampling ETAAS.Boats made of platinum were used for the determination of Hg and graphite boats for the determination of Cd and Pb. In their study of 50 brands of cigarettes from two western and two eastern European countries they found that the concen- trations reflected local pollution in the growing areas. Indirect methods for the determination of alkaloids using FAAS for quantification were developed by a group at the University of Cordoba Spain (93/3398,93/3920). A continuous liquid-liquid extraction system separated the alkaloids as ion- pairs with metal-containing anions such as Co( SCN)2- into 1,2-dichloroethane. The metals were then determined in the organic solvent phase. For cocaine (93/3920) the method was most sensitive when BiI,- was used and most selective with Fe( SCN) -.For amylocaine papaverine and bromhexine hydrochloride (93/3398) Bi14- and CO(SCN),~- were used. 1.9. Progress for Individual Elements 1.9.1. Aluminium Two reviews on the determination of A1 in biological materials have been published. Approaches to sample preparation and methods of analysis for A1 in serum and plasma were reviewed by Taylor and Walker (93/1060) whilst Brenner (93/C3000) reviewed the capabilities of ICP-AES for the determination of A1 in biological materials. In this latter review the use of direct aspiration of serum by USN was examined in depth. Procedures for minimizing contamination in the determination of pharmaceuticals for A1 by ETAAS were described by Ericson (93/3 156). A detailed comparison of platform wall and probe ETAAS methods for the determination of A1 in clinical Juids was undertaken by Gayon et al.(93/1025). Platform atomization using STPF conditions was selected as the best method for the analysis of serum and dialysis fluids. Dilution of samples 1 + 1 with Triton-X100 and aqueous calibration was found to be sufficient for accurate analysis. Potassium dichromate was found by Xu et al. (93/1026) to be an effective modifier for the determination of A1 in human brain tissue. A K,Cr,O concen- tration of 1 mg ml-’ in the HNO digest solution eliminated interferences from alkaline earths and P. Concentrations of A1JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 113R in brain tissue were 6.2-9.8 pg g-'. Trentini et al. (94/610) compared ICP-MS and ETAAS methods for the determination of A1 in dialysis solution and serum from hemodialysis patients. For analysis by ICP-MS samples were diluted 1 + 4 with HNO (0.16% final concentration). For ETAAS samples were diluted 1 + 4 with Mg(NO,) .Triton X-100 was added to the modifier solution for analysis of serum samples. In the clinical setting interest in A1 toxicity has focused on the kinetics of A1 and the accumulation of A1 in renal dialysis patients. Baker et al. (93/2537) developed an extremely sensitive AMS method for the determination of 26A1 in biological fluids following administration of the tracer to human volunteers. A detection limit of 3.8 x lo-'* for 26A1 was achieved. The method was used to study gastrointestinal uptake and renal excretion of A1 over a 3 month period.To investigate the absorption of A1 following portal or systemic administration of Al Xu et al. (93/4043) measured blood and bile A1 concentrations over an 8 h period. Their results suggested that previously reported values for 'oral' bioavailability underestimated A1 absorption. The A1 concentration in lymphocytes of patients on regular hemodialysis was determined by Kisters et al. (93/4115) using ETAAS. As lymphocyte volume could not be accurately calcu- lated the lymphocyte A1 concentration was referred to lympho- cyte protein. Lymphocyte A1 concentrations in patients on dialysis were 23.8 pg g protein as compared with 18.4 pg g-' protein for controls. Following administration of A1 to uremic rats Vukicevic et al. (93/4074) measured A1 in various regions of the brain by ICP-AES. They found that co-administration of 24,25-dihydroxyvitamin D restricted accumulation of A1 within perivascular astrocytes of the blood brain barrier.An active role for A1 in the skin reaction following vaccination against diphtheria/tetanus/pertussis/ poliomyelitis was demonstrated by Pineau et al. (93/4113). In a rabbit model concentrations of A1 in subcutaneous nodules occuring at the injection site were determined by a sensitive ETAAS method. The results indicated a foreign body reaction to A1 as the underlying mechanism. There has been marked interest in occupational exposure to A1 during this review year. The problems encountered in biological monitoring of occupational exposure were discussed by Schlatter et al.(94/176). The determination of A1 in plasma and urine by ETAAS was described and the kinetic parameters of A1 were investigated in order to develop criteria for biological monitoring. The uptake and excretion of A1 in workers exposed to different A1 compounds was investigated by Drabloes et al. (93/3675). Serum and urine A1 concentrations were determined by ETAAS. A significant correlation between weekly average air A1 levels and weekly average urinary A1 was found for individual workers. On a group basis urinary A1 excretion was lower in workers exposed to AlF compared with workers exposed to Al,O even at higher A1 exposures. Using ETAAS Elinder et af. (93,4116) determined A1 in blood urine and bone biopsy samples from welders with long term exposure to Al. Urinary excretion in two welders was ten times the level found in non-exposed individuals and remained high years after exposure ceased. Blood and bone A1 levels were also elevated.The authors concluded that long term exposure to A1 lead to accumulation of the metal in the body. The binding of A1 to proteins in sera from A1 workers was investigated by Favarato et al. (93/1059). Proteins were separated by SEC and the A1 concentration of the fractions was determined by ETAAS. Normally the albumin/transferrin fraction was the main A1 carrier but desferroxamine treatment led to an increased binding of A1 to a fraction termed albindin. Tea drinkers will be interested to note that Drewitt et al. (94/105) found no increase in plasma A1 following ingestion of 1.6 mg of A1 from tea.The authors considered that tea drinking did not contribute to the body burden of Al. 1.9.2. Antimony Fructose-6-phosphate kinase immobilized on glass beads and packed in a glass microcolumn was used by Calle-Guntinas et al. (94/585) for the speciation of Sb"' and Sb". Antimony(r1r) bound selectively to the enzyme and was eluted with 3% lactic acid. The eluted Sb"' was determined directly by ETAAS. A 5- fold enrichment and recovery values of 75 & 5% were achieved for Sb"' in deionized tap and sea water. The immobilized enzyme retained its activity for at least 200 analyses. 1.9.3. Arsenic Appreciation of the value of As speciation for evaluating As exposure has stimulated the development of methods for determining inorganic and organic As compounds in urine and other biological matrices.Recent developments in quanti- tative methods for the determination of As species have been reviewed by Ni (93/C3047) and the IUPAC Commission on Microchemical Techniques (93/2565). Sample preparation was identified as the main source of analytical problems. Separation by anion- and cation-exhange HPLC followed by on-line ICP-MS detection allowed Larsen et al. (93/3224) to quantitat- ively determine eight As species in urine. Oxidation of As"' to As" during chromatography was prevented by the addition of ascorbic acid and interference by the polyatomic species 40Ar35C1 was eliminated by the chromatographic separation of C1- from the analyte. Calibration was by standard additions. The use of didodecyldimethylammonium bromide ( DDAB) vesicles as the mobile phase gave Liu et al.(94/596) enhanced separation of inorganic As and As metabolites in human urine by reversed-phase HPLC. Detection of As by HG-ICP-AES was also enhanced by the presence of DDAB. Rapid separation of As species from urine was achieved with disposable cation- exchange cartridges by Nixon and Moyer (94/378) prior to analysis by ETAAS. Murer et al. (93/3084) comprehensively evaluated a direct FI-HGAAS method for As in urine for the biological monitoring of occupational exposure. Standard additions calibration was necessary for acceptable performance at low urine As concentrations. The detection limit (2.9 pg 1-') was sufficiently low to discriminate non-exposed and low- exposed individuals. A number of different analytical approaches for the determi- nation of total As in biological tissues and fluids have also been described during this review period.Poluyanov (93/4108) extracted As with a-methyl-cyclohex-A3enecarboxylic acid for determination by ETAAS. Tanaka et al. (93/3572) diluted whole blood with 0.02 mol I-' HNO for the measurement of As by ICP-MS. Digestion with nitric acid in a microwave oven dilution with HC1 and analysis with HGAAS was the technique used by Navarro et al. (93/2682) to determine As in fish. Accurate determination of As by ICP-MS can be severely affected by interferences from the polyatomic species 40Ar35C1. Various approaches for overcoming this interference have been published. Walcerz et al. (93/C1351) eliminated the 40Ar35C1 signal and obtained a 10-fold increase in the As signal by hydride generation.Removal of C1- from the sample by anion- exchange chromatography was the approach taken by Goosen et al. (94/613). A Dionex 1x8 column was used in the NO3- form to remove C1- from urine and acetate form to remove C1- from serum. Isobaric fractionation to remove the 40Ar35C1 interference was shown by Kershisnik et al. (93/2391) to be inaccurate for urinary As determination. They recommended a proportionality method based on the 16035C1:40Ar35C1 ratio which gave improved accuracy as demonstrated by comparison with analysis by ETAAS. 1.9.4. Bismuth Stewart and Lyon (93/C1066) used ICP-MS to monitor plasma Bi concentrations in a case of Bi poisoning. This analytical technique was considered to be particularly well suited to the investigation of cases of iatrogenic toxicity.Eisman et al. (93/3398) used the measurement of Bi and Co by AAS to indirectly determine the alkaloids amylocaine papaverine and114R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 bromhexine hydrochloride. Ion pairs formed between the alkaloids and the inorganic complexes Bi1,- and Co( SCN)42- were extracted with 1,Zdichloroethane. Both Bi and Co in the organic phase were measured by FAAS. The method could accurately measure the alkaloids over the concentration range 0.5-175 pg ml-'. 1.9.5. Boron The use of B in neutron capture therapy for cancer has led to methods being developed for the determination of B in clinical materials. Bennett et al. (92/2293) evaluated the technique of secondary ion MS for determining the uptake and intracellular localization of B.1.9.6. Cadmium Methods for the determination of Cd by ETAAS often employ a chemical modijer to stabilize the analyte. A comparison of organic and inorganic chemical modifiers for Cd determination was made by Komarek et al. (93/2673). A method using 0.03 mol l-.' HNO as modifier was described giving a limit of detection of 45 ng I-' and recoveries of 97-101 % with standard addition calibration. Two ETAAS methods for the direct determination of Cd in urine with minimal sample treatment have been described. In the method described by Gayon et al. (93/2081) probe atomization with deuterium background cor- rection was used to separate the Cd signal from the high background. No sample pre-treatment other than a 1+3 aqueous dilution or chemical modification was necessary.By careful selection of heating parameters and sample volume Fraile et al. (93/3953) determined Cd in urine directly by ETAAS using STPF conditions. Accurate results were obtained for three urine CRMs. For both methods satisfactory results were obtained with aqueous standards calibration. The analysis of Cd in biological CRMs was used by Gine et al. (94/285) to evaluate the performance of a simple low-cost tungsten open- coil furnace for ETAAS. Digested samples were introduced manually into the furnace which was heated with a programm- able power supply. Integrated absorbance measurements were made. Simultaneous determination of Cd and Cu in urine was carried out by Fernando et al.(93/C1467) with a newly designed continuum source AA spectrometer. The detection limit achieved for Cd on the new instrument was 0.01 pg 1-' which was an order of magnitude lower than previously reported for continuum source AA instruments. A stable isotope ID-GC-MS method using lo6Cd as internal standard was described by Aggarwal et al. (93/3597) for the determi- nation of Cd in urine. Cd was chelated from an HN03-H202 digest with lithium bis( trifluoroethy1)dithiocarbamate for GC separation. The addition of an internal standard was necessary to minimize memory effects. Preconcentration is normally required for the quantitative determination of Cd in biological samples by FAAS and ICP- AES. Cadmium was concentrated from urine with sulfhydryl cotton desorbed with HCl and measured by FAAS in a method developed by Wen et al.(93/1147). Xu et al. (94/267) described a FI ex traction preconcentration procedure for the determination of Cd and Cu by FAAS. Acid-digested tissue or urine was diluted with HN03 and extracted with diethylam- monium diethyldithiocarbamate on-line on a RP-C18 micro- column. The Cd chelate was eluted with methanol directly into the nebulizer of the spectrometer. A 20-fold enrichment factor for Cd and Cu was achieved. A significant enhancement in sensitivity was achieved by High et al. (93/2897) through the use of a thermospray-microatomizer interface for FI and HPLC coupled FAAS. The interface pyrolysed organic inter- ferences and gave an LOD for Cd two orders of magnitude lower than conventional FAAS.Liquid anion-exchange extrac- tion with 5% Aliquant 336 in IBMK and back-extraction into HC104 was used by Bandyopadhyay and Das (94/414) to preconcentrate Cd from acid digests of biological tissues for FAAS determination. To monitor occupational Cd exposure Karakaya e f al. (94/428) developed a FAAS method for the determination of Cd in blood. A 20-fold increase in sensitivity over conventional solution nebulization was achieved with column preconcen- tration and a slotted quartz tube atom trap. Almendro et al. (93/2720) extracted Cd from microwave-digested biological RMs with 175-bis(di-2-pyridylmethylene) thiocarbonohydrazide into IBMK for ICP-AES determination. The effects of pH chelation concentration and ionic strength on extraction efficiency were evaluated.An HPLC-ETAAS method was developed by Sun et al. (93/2684) for the determination of dietary-induced Cd-metallothioneins in rabbit liver and kidney. Homogenized tissue was heated at 60°C and centrifuged. The filtered supernatant was applied to a DEAE anion-exchange column to separate metallothionein isoforms. Cadmium was measured in the eluate to identify and quantify metallothionein. 1.9.7. Calcium The determination of Ca by FAAS with Zeeman background correction was described by Merrer et al. (93/3459). Analysis was automated with a commercially available LIM system. A FAAS method using an N,O-C,H2 flame was employed by Cai et al. (93/3563) for the determination of intracellular and extracellular Ca in infantile pneumonia complicated by respir- atory failure.Erythrocyte Ca was significantly increased and plasma Ca decreased in this condition. Calcification of heart tissue has been examined by two groups. Bernacca et al. (93/4030) measured deposition of Ca and surface deposition of Ca in bovine pericardium by FAAS and XRF respectively. Mineralization of the aortic wall in hypercalcaemic rabbits was examined by Rokita et al. (93/3524). Freeze-dried tissue was analysed by PIXE and AAS for elemental composition. A 20% elevation of serum total Ca induced calcification of the aortic wall. 1.9.8. Chromium The elusive role of Cr in glucose horneostusis continues to be investigated. Morris et al. (93/C1064) used a hyperinsulinaemic clamp technique to investigate the response of plasma Cr to elevated insulin concentrations of 90-130 pU m1-I.Plasma Cr levels fell rapidly from a fasting mean of 8.4 nmol 1-' to 3 nmol 1- following insulin infusion and remained depressed throughout the infusion. The same group measured plasma and urine Cr concentrations by ETAAS following oral glucose challenge (93/3974). A significant inverse relationship between plasma Cr and insulin was observed which was not explained by increased urinary excretion of Cr. The authors suggested that the fall in plasma Cr might be associated with changes in the uptake of Cr by insulin sensitive tissues. Procedures for the determination of Cr in biological materials by AAS have been reviewed by Rubio et al. (93/4024). The review considered sample pre- trea tmen t instrument param- eters and interference effects for both FAAS and ETAAS.Various sample preparation methods for the determination of Cr and A1 by ETAAS were compared by Bulska et al. (93/2185). Optimum results were achieved using dilution in 0.1 mol 1-' HNO and addition of 0.2 g 1-' Mg as Mg(NO,) for chemical modification. Magnesium nitrate chemical modification was also applied by Miller-Ihli and Greene (93/4027) to the deter- mination of Cr in foods and biological materials. Quantitative analysis was achieved with STPF conditions and direct cali- bration against aqueous standards. 1.9.9. Cobalt A coupled GC-MS method was developed by Aggarwal et al. (93/2423) for the determination of Co in urine. Stable enriched 62Ni was added to samples as an internal standard. Cobalt and Ni were chelated with lithium bis( trifluoroethyl) dithiocar-JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 115R bamate and detected by selective ion monitoring.Good agree- ment was obtained between values determined by the GC-MS method and by ETAAS. The method was sufficiently sensitive to measure urinary Co concentrations down to 1 pg l-'* and was accurate over a 100 fold dynamic range. 1.9.10. Copper A large proportion of the articles in this year's review of Cu are concerned with the metabolism of Cu in health and disease. A number of different instrumentation techniques have been applied to the determination of Cu in tissues and body fluids. The determination of total Cu and Zn by AAS was used by Sutomo et al. (94/451) to evaluate the effect of moderately elevated Zn intake on Cu metabolism in the mouse.Copper concentrations in human brain tumor tissue were determined by Yoshida et al. (93/4022) also by AAS. Results showed that Cu concentrations were elevated in diseased tissue and were correlated with the malignancy of the tumor. Honey et a!. (94/452) monitored the distribution of Cu in human placenta and foetal membranes during gestation. Tissue Cu measure- ments were made by DCP-AES. Lyon et al. (93/C1338 93/C1062) measured stable Cu isotope ratios in serum by ICP-MS to investigate oral uptake and Cu metabolism in humans. Gel filtration of serum followed by acid precipitation of the eluted protein was necessary to overcome interferences by NaAr' and SO,H+on the 63Cu and 65Cu masses respect- ively. Both dialysis and gel filtration followed by AAS were employed by Montasser et al.(93/4098) to compare serum Cu binding components in different mammalian species. They considered that for some species transcuprein and complexes of low relative molecular mass were the main Cu transport proteins rather than ceruloplasmin and albumin. In the occupational setting Vasikaran et al. (93/4116) assessed the Cu status of lead workers through the measure- ment of serum Cu by FAAS. The significantly elevated levels of Cu and ceruloplasmin were considered to be due to concomi- tant uptake of Pb and Cu through inhalation. Liu et al. (94/545) determined Cu in urine directly by FAAS with Zeeman background correction. A range of linearity of 5-100 pg 1-' and an LOD of 5 pg I-' were reported. 1.9.1 1. Fluorine A novel approach to the determination of total F in biological fluids was reported by Cob0 et al.(94/162) which involved the measurement of the AlF radical formed in a graphite tube after in situ oxygen ashing of untreated samples. Absorbance of the AlF radical was measured at 227.45 nm. Reasonable precision (5-10%) and an LOD of 14 pg I-' was achieved. 1.9.12. Gadolinium Gadolinium compounds were employed as tracers by two groups to study blood bruin barrier permeability. Kenney et al. (93/3311) took sequential measurements of plasma Gd-diethyl- enetriaminepentaacetic acid (Gd-DTPA) by ICP-AES and sequential magnetic resonance images of tissue to estimate blood-tissue transport coefficients (Ki) in rat tumor models. Unakami et al. (94/454) studied arachidonate induced lesions of the blood brain barrier in rats through measurement of serum and brain tissue Gd by ICP-AES after administration of Gd containing drugs.1.9.1 3. Germanium Optimum conditions for the determination of Ge in herbal plant material by ETAAS were examined by Cheng et al. (93/3947). Greatest sensitivity was obtained when Ge was chelated with phenylfluorone extracted into IBMK and N N - dimethylformamide and analysed by ETAAS using NH40H as a chemical modifier. Germanium in human hair was deter- mined by HGAFS in a method described by Gong et al. (93/2151). Washed hair (0.5-2 g) was digested by heating with HN0,-H3P04 (9 1). The digest was boiled firstly with 30% H202 then with a small quantity of 0 s in H2S04 and diluted to 10ml. A 2ml aliquot of the final solution was taken for analysis.The concentration of Ge in various tissues was determined by Nakai et al. ( 93/2302) using ICP-MS. They investigated the effect of high concentrations of salts (NaCl KCl CaCI,) and acids on the intensity of the Ge signal and found that HNO was most appropriate for digestion of tissue samples. 1.9.14. Gold Methods for the determination of Au in biological fluids continue to be developed both to monitor theraputic adminis- trations of Au containing antiarthritic drugs and to study their metabolism. Zhao et ul. (93/2437) determined Au based drugs and their metabolites in the urine of arthritis patients using reversed-phase ion-pair chromatography with tetrabutylam- monium chloride as the ion pair agent and ICP-MS for on-line detection.Chromatographic conditions were evaluated for several Au-containing compounds. Recovery of gold containing species in urine was greater than 90%. A dicyanogold(1) anion was measured in the urine of several patients. 1.9.15. Iodine Yoshina and Morita (93/2301) applied ICP-MS to the determi- nation of I in biological fluids. By using standard additions calibration to overcome matrix effects I could be determined with a precision of 3-4%. No memory effect was observed when samples were diluted with NH40H. High-performance liquid chromatography coupled with on-line detection with ICP-MS was employed by Kikuo and Tadashi (93/3435) for the speciation of I and iodo amino acid components in enzymic digests of thyroglobulin. The method was reported to be ten times more sensitive than conventional methods using stable isotopes.1.9.16. Iron Growing interest in the application of ICP-MS to the determi- nation of trace elements in biological matrices is reflected in studies employing this technique for the measurement of Fe in human tissue and biological fluids. The attractiveness of the technique lies in its sensitivity wide dynamic range and capability to measure stable isotopes thereby eliminating the need for radioisotope tracer studies. Stuhne-Sekalec et al. (93/2322) used ICP-MS for the on-line isotope specific determi- nation of Fe-protein complexes separated by liquid chromatog- raphy. They investigated the distribution of Fe-protein species in human and rat tissue following administration of 57Fe. The ferritin-hemosiderin ratio in liver and heart tissue was shown to be an indicator of Fe loading.The administration of 57Fe and 58Fe isotopes and subsequent measurement of changes in the 57Fe:56Fe and "Fe?Fe ratios in erythrocytes by ICP-MS was the approach taken by Barrett et al. (93/2932) to determine absorption of non-haeme Fe in pregnant women. Hansen et al. (93/2550) described a procedure to assess Fe bioavailability from pharmaceutical preparations with 54Fe as a tracer and isotope ratio measurements made by FAB-MS. Iron tablets enriched with 54Fe were administered to subjects and Fe utilization was evaluated from changes in the 54Fe:56Fe ratio in erythrocytes. Figures for Fe bioavailability were comparable with those obtained by radioisotope tracer studies. Various digestion procedures for the determination of Fe in biological materials were compared by Beran (94/168).Dissolution of RMs with HN03 digestion with HN03-HC104 and dry ashing all gave low recoveries of Fe which appeared to be lost as insoluble silicates and phosphates. Acid digestion procedures gave the best results. The relationship between Fe and Mg levels in normal and pathological prostatic tissue was studied by Picurrelli et al. (93/4114). Iron and Mg concen-116R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 trations in serum and prostatic tissue were determined by AAS. Significant changes in the tissue concentrations of the two elements were found in different disease states. 1.9.17. Lithium The potential value of Li as a marker of Nu re-absorption in the renal proximal tubule has prompted the development of methods to determine endogenous Li concentrations in body fluids.Do1 et al. (93/1038) explored the feasibility of using FAES to determine Li concentrations in human serum and urine. No significant matrix effects were observed but back- ground correction by derivative spectroscopy was necessary. Normal Li concentrations were 1.17k0.47 pg 1-' in serum and 29.3+ 11.7 pg 1-' in urine. A sensitive method for the determination of Li in nanolitre volumes of tubular fluid by ETAAS was developed by Boer et al. (93/3232). A 4-fold improvement in sensitivity was achieved by using a tantalum foil lined graphite microboat in the atomization step. Calibration standards were prepared in 0.3 mmol-' NH4N03-0.75 mmol - ' TCA and no background correction was necessary.Wang et al. (93/4017) investigated the influence of other ions on the determination of Li in human blood saliva and urine by FAAS. Samples were dry ashed with 1% H2S04 as an ashing aid to prevent losses of Li. To determine Li in lyophilized serum BCR reference mate- rials for certification Lamberty et al. (93/3448) developed an ID-TIMS procedure. Reconstituted serum samples were spiked with previously characterized 6Li tracer and digested with a HN03-H202 mixture. Lithium was separated on a cation- exchange column and eluted with 0.3 moll-' HCl for analysis. An ID-MS method was also described by Fleishman et al. (93/2296) for the determination of endogenous Li in plasma and urine to study Li clearance in hypertensive and kidney transplant patients.An 6Li tracer was added to the sample which was dried and extracted with 0.1 mol-' HCl. The extract was treated with 30% H202 and chromatographed on paper to separate Li from interfering elements. 1.9.18. Lead Method development for the determination of Pb in blood and other biological matrices continues apace. The findings of a study of the effects of two chemical modijiers on Pb atomiz- ation under STPF conditions led Granadillo et al. (93/3233) to develop a method using a 0.5 mg 1-' Pd-0.2% citric acid modifier. The method was validated by determining Pb in a wide range of biological RMs and was used to establish levels of Pb in blood and urine of healthy Venezuelan adults. A Pd-Mg(N03)2 modifier was proposed by Penninckx et al.(93/3955). They found the combination of Pd and Mg(N03)2 to be more effective than either Mg(N0,)2 alone or NH4H2P04 for the direct determination of Pb in diluted blood urine and milk with aqueous calibration. Different heating programmes were developed for each sample type. Digestion with HNO was found by Kargosha and Shivapoor (93/C1622) to be the most effective pre-treatment for the determination of Pb in serum by ETAAS with a rapid (40s) ramp heating programme. To suppress volatilization of Pb and improve destruction of the organic matrix Wang et a/. (93/1136) introduced a 20 s oxygen ashing step into their ETAAS method for Pb in blood and food samples. Electrothermal and flame AAS methods for the determi- nation of Pb in urine have appeared. Gayon et al.(94/583) determined Pb in urine directly by ETAAS with probe atomiz- ation and deuterium background correction. No pre-treatment other than dilution with water or chemical modification was necessary and accurate results were obtained with aqueous calibration. Both Liu et al. (94/543) and Yao and Du (93/2148) extracted Pb from urine by coprecipitation with Bi( for determination by FAAS. In both methods the Pb precipitate was dissolved in HC1 for analysis. Speciation of alkyllead compounds in urine was studied by Shum et al. (931943) using microbore column LC-ICP-MS. Alkyllead compounds were separated as ion pairs by reversed-phase chromatography and measured by direct injection nebulization into the ICP. Lead in seminal fluid was determined by ETAAS in a sensitive method described by Jurasovic and Telisman (94/561).Samples were deproteinized with HNO and measurements were made using STPF conditions and Zeeman background correction. Standard additions calibration was necessary for accurate results. Normal values for Pb in seminal fluid were 8.6 (4.2-16.6) pg 1-'. An automated on-line FI-ETAAS system incorporating microwave digestion was designed by Burguera and Burguera (94/284) for the determination of Pb in biological materials. Powdered samples of CRMs were suspended in 0.4% Triton X-100 and mineralized with HCl-HNO in a PTFE coil. Precise volumes of the digest were transferred to the furnace by air displacement. Subramanian et al. (93/C1548) described a contamination free sampling technique and ETAAS method for Pb in bone biopsy samples.Bone samples digested in HNO were analysed with Pd chemical modification and STPF conditions. The application of XRF to in uiuo measurement of Pb in bone has received considerable attention. In oiuo XRF methods were reviewed by Todd et al. (93/3896) who considered '"Cd XRF to be the most appropriate technique in view of the lower LODs achieved and lower effective radiation doses. They determined the radiation doses received by children and adults for an in oiuo measurement of tibia Pb by two '09Cd K-line XRF systems (93/1769). The utility of L-line XRF for bone Pb measurements was critically evaluated by Preiss and Tariq (93/1766). Radiation exposure doses to children and adults from L-line XRF measurements of tibia1 Pb were re-calculated by Slatkin et al.(93/3874) on the basis of a recommended reduction of the tissue weighting factor for bone surface. Using an established XRF technique Chettle et al. (93/1860) took repeated measurements of tibia Pb in a group of occupationally exposed workers. The relationship between tibia Pb and cumu- lative blood Pb in this longitudinal study was entirely consist- ent with that previously found in cross-sectional studies. Concern over low level Pb toxicity continues to stimulate studies on environmental sources of Pb exposure. Stable isotope ratio studies using ICP-MS have been used by Delves (93/C3041) to identify specific sources of Pb exposure. The imprecision of the technique ( ~ 0 . 5 % ) is sufficient to detect changes in the 206Pb:207Pb ratio from environmental exposures.Significant deviations from the normal 206Pb:207Pb ratio were observed as a result of increased uptake of Pb from drinking water soils and petrol. Dale et al. (93/C1339) compared ICP-MS and TIMS for measurement of stable Pb ratios in sweat and urine samples in a study of skin absorption of Pb. Excellent agreement was obtained between the two methods and the results demonstrated the utility of ICP-MS for measur- ing Pb iotope ratios at very low concentrations. Umbilical cord blood Pb concentrations were measured in babies from a district of Germany by Meyer et al. (93/4128). Factors infuencing the concentration of Pb were birth weight mother's age proximity of home to main roads and lead water pipes. The concentration of Pb was not influenced by parental occupation or daily exposure to traffic. Blood Pb concen- trations in the general population of Tarragona Province were determined by Schumacher et al.(93/4103). The blood Pb concentration was significantly correlated with age smoking and drinking habits. 1.9.19. Magnesium Changes in plasma and erythrocyte Mg levels after intense exercise were monitored by Cordova (93/3323) using FAAS. Small increases in both plasma and erythrocyte Mg were observed which may have been a consequence of changes in plasma volume. An FAAS micromethod for the determinationJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 117R of Mg in myocardial biopsies was developed by Millane et al. (93/2115). Lyophilized tissue was digested with pepsin A and centrifuged.The supernatant was mixed with LaC1 and ana- lysed by FAAS with an air-acetylene flame. For the determi- nation of Mg in muscle tissue by FAAS Reinhart et ul. (94/379) hydrolysed the tissue with concentrated HNO at 80 "C. The digest was diluted 40-fold with 5 g 1-' LaCl 1.9.20. Manganese Various analytical approaches have been applied to the direct determination of Mn in biological materials by ETAAS. Ronchi et al. (93/2697 93/2698) determined Mn in serum and urine using ETAAS with Zeeman effect background correction. Pretreatment of both serum and urine samples was a 1+1 dilution with 0.2% Mg( for chemical modification. Linear calibration up to 5 mg 1-' was achieved for both biological matrices. Ohta et al. (93/3938) utilized an Mo tube atomizer for the determination of Mn in several biological materials.Optimum atomization characteristics were achieved with a purge gas of Ar and H2 and interferences were eliminated by the addition of thiourea to the samples. For the direct determi- nation of Mn in ground waters by ETAAS Wu et al. (93/3970) coated the graphite tube with a mixture of La and Zr. This pre-treatment significantly improved analytical sensitivity and stability and prolonged the lifetime of the graphite tube. 1.9.21. Mercury Much of the method development in the determination of Hg in biological materials has been directed at selective methods for Hg speciation studies. Shum et al. (93/1943) separated five cationic Hg species by microbore column LC-ICP-MS. The Hg species were chromatographed as ion pairs on a reversed- phase column and the eluent introduced into the plasma by direct injection nebulization.Memory effects which are a significant problem for Hg determinations were reduced and an order of magnitude improvement in the LOD was obtained with this method of nebulization. In an improved GC-AFS method described by Lian et al. (93/C1544) inorganic and organic Hg species were ethylated preconcentrated onto Carbotrap and desorbed onto a GC column cooled in liquid N2. The species were separated by isothermal GC and decom- posed at 800 "C for quantification by CVAF. Inorganic and organic Hg in kidney liver and brain tissues were determined by Atallah et al. (94/422) using continuous flow CVAAS. Tissues were solubilized at 60 "C with NaC1-L-cysteine-NaOH and injected into the continuous flow system for reaction with SnCl,.Methylmercury was photo-oxidized by on-line acidifi- cation with 6 mol 1-' HCl and potassium persulphate. A comparative study of MIP-AES and CVAFS as detectors for head-space GC determination of organomercury in biological samples was undertaken by Lansens et a!. (94/70). A Beenakker-type cavity with an Ar plasma gave best sensitivity for MIP detection. However much better LODs were obtained with detection by CVAFS which was also cheaper and easier to manipulate. An FI system for on-line microwave digestion of liquid samples and detection by amalgamation CVAAS was developed and evaluated by Welz et al. (93/3924). Urine samples were diluted stabilized with K2Cr207-HN03 and mixed with a bromination agent.Good recoveries of five Hg species were obtained from CRMs. The determination of organomercury by GC-ETAAS was reviewed by Harms (93/3641). Improved quantification of Hg was achieved with a laboratory -buil t interface. A sensitive method for the determination of total Hg in urine by ETAAS was described by Zhou and She (94/150). Urine samples were treated with 1 ml of 1 mgml-' Pd and 0.15 ml of 16 moll-' HNO and diluted 1 + 1 with HNO,. Measurements were made with Zeeman-effect background correction. The detection limit was 0.26 ng. Hanna and Tyson (93/C1540) determined total Hg in urine and water by FI-CVAAS. An oxidation step with solid KMn0,-H2S0 was employed to reduce organomercury to the inorganic state. A rapid single stage gold amalgamation technique with CVAAS detection was developed by Liang and Bloom (93/3229) and compared with the standard dual amalgamation methods currently employed for low level Hg measurements.Comparable results were achieved by paying particular atten- tion to the orientation of the trap and using peak area measurements. A detection limit of less than 1 pg was obtained with the single-stage method and anlaysis time was reduced by a factor of 5. The results of an interlaboratory exercise to certify the Hg content of BCR RM 422 Cod Muscle led Campbell et al. (993/1005) to investigate the interference effects from chemical species on Hg determination by ICP-MS. They concluded that the chemical species of Hg in the sample and standards influenced the results obtained by this technique.Concerns over exposure to Hg from dental amalgams has prompted two studies. Thomassen et af. (93/1212) measured Hg in blood urine and breath of 147 individuals with dental restoration using CVAAS. Both urine and breath Hg concen- trations showed a correlation with the amount of dental restoration with amalgam. Factors affecting blood Hg concen- trations in dentists were examined by Chang et al. (93/4037); blood Hg concentrations were measured by CVAAS. A signifi- cant increase in total and inorganic Hg was found in practicing dentists compared with controls. Hovever there was no evi- dence of transformation of inorganic Hg into more toxic organic forms. 1.9.22 Molybdenum An evaluation of different chemical modifiers for the determi- nation of Mo in biological fluids by ETAAS was undertaken by Barrera et al.(93/C1638). With Pd-Mg(NO,) or Pd-hydroxylamine hydrochloride as chemical modifiers the optimum analytical conditions were a three-stage temperature programme with low-temperature ashing (600 "C) and atomiz- ation at 2700°C. The addition of Triton X-100 to serum and urine was necessary to overcome sample introduction prob- lems. The urinary elimination of Mo in healthy subjects was measured by Allain et al. (93/2355) using ICP-MS. Mean urinary Mo concentrations of 21 15 mg g-'creatinine were found in two separate groups. Measurements made at the three main Mo isotopes gave similar results. For isotope ratio and bioavailability studies of Mo Soltain-Nesham (93/3776) described a chelate GC-MS method using sodium bis(triflu0- roethy1)dithiocarbamate as the chelating agent.A detection limit of 50 ng and a precision < 1 YO were reported. 1.9.23. Nickel For the determination of ultratrace metals in biological matrices by ICP-AES liquid-liquid extraction is often necessary to achieve the required analytical sensitivity and reduce matrix interferences. This approach was adopted by Alonso et af. (93/1034) for the determination of Ni in various biological RMs including human urine. Following microwave digestion Ni was extracted with 1,5-bis(di-2-pyridylmethylene)thio- carbonohydrazide into organic solvent (butanol or IBMK). Using IBMK as the organic phase a concentration factor of >30 was achieved. An LOD of 0.3 mg 1-' was quoted and calibration was linear over three orders of magnitude.Xu et al. (94/565) determined Ni in serum and urine directly by ICP-MS. For analysis of Ni in serum polyatomic interferences were corrected for by internal standardization with Rh and principal components analysis. Serum Ni concentrations down to 0.5 mg 1-' were accurately measured. For urinary Ni measure- ments samples were diluted and Ca was quantitatively precipi- tated with oxalic acid. The methods were used in studies of oral Ni absorption using enriched stable isotopes. The authors suggested the use of enriched isotopes might overcome some of the contamination problems encountered with naturally118R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 abundant Ni. Li et al. (93/1146) developed a direct method for the determination of Ni in whole blood by ETAAS in which samples were treated with heparin and diluted with H,O.1.9.24. Platinum Studies by Bader et al. (93/1092) showed that dry ashing was unsatisfactory for the quantitative determination of Pt in animal tissues by AAS. Improved accuracy was achieved with wet ashing at normal or elevated pressures followed by dithi- zone extraction. Matrix effects were small and the recovery of Pt was greater than 90% in the presence of high concentrations of Mg and Ca. Both Toothill et al. (93/3770) and Allain et al. (93/2297) evaluated ICP-MS for the determination of Pt in biological materials. In the first of these studies ICP-MS was used to measure Pt in tissues following administration of Pt- containing drugs. Sensitivity of the method was comparable with NAA and better than ETAAS.The second group also considered ICP-MS to be the most sensitive and best suited method for the measurement of both 'free' and total plasma Pt from patients treated with Pt-containing drugs. The detection limit for this ICP-MS method was reported to be 0.5 mg I-'. 1.9.25. Selenium There have been further developments in ETAAS hydride generation MS and XRF methodologies for the determination of Se in biological matrices. Determination of Se by ETAAS is prone to chemical and spectral interferences by matrix compo- nents. The effect of MgCI and CaCI on the atomization of Se was investigated by Aller and Olalla (93/1027). Interferences were reduced by chemical modification with Pd or Hg optimiz- ation of ashing temperature and Smith-Hieftje background correction.The effectiveness of Ni and Pd as chemical modifiers for the determination of Se species in human urine was evaluated by Laborda er a/. (94/584). The interference effects from urine components were minimized by diluting samples 1 + 4 with H,O adding 100 pl of Ni and introducing a cool- down step between ashing and atomization. For Se in whole blood Janssen (94/197) chose a Cu-Pd modifier to stabilize Se after in situ air ashing. Tummalapalli et al. (93/C1436) thoroughly examined sample digestion procedures furnace parameters and modifiers for the determination of Se in bovine heart tissue by ETA AS. Aqueous standards and standard additions calibration were also compared. Hydride generation techniques for Se have been coupled to a range of detection systems.In a method described by Ni et al. (93/3353) H,Se generated from acid-digested urine was adsorbed onto a heated Pd-coated graphite tube for quantifi- cation of Se by ETAAS. A detection limit of 2pg 1 - ' and recoveries of 92-98 YO were reported. Few interferences and high sensitivity were found by Tan and Zhao (93/1283) with a HG-nondispersive AFS method for Se in serum. A newly designed continuous flow HG system which minimized C1 interferences was developed by Buckley et al. (93/2154) for Se determination by ICP-MS. Two alternative sample pre-treat- ments gave final solutions containing 3.8 or 7.2 nmol I - ' HCl. Copper interferences were eliminated by adding 0.2 mol I - ' NaI to the NaBH solution or maintaining a high HCI concentration. Both procedures gave accurate results for a variety of biological RMs.The importance of high concen- trations of HCI for complete reduction of Se"' to Se'" and hydride generation were re-emphasized by Tamari et al. (93/2195) and Mattos et a!. (94/181) the latter group preferring dry ashing with Mg(NO,) for digestion of serum. Two GC- M S methods for the determination of Se in human body fluids have been described. Three derivatizing agents were compared by Aggarwal et al. (93/2321) for the analysis of Se in urine using ID-GCMS with 76Se as internal standard. No memory effect and greater precision were obtained with 4-trifluoromethyl-o-phenylenediamine. The met hod was vali- dated by analysing the urine reference material NIST SRM 2670. Stable enriched 76Se was also used as the internal standard for the determination of Se in blood and urine by capillary GC-MS by Ducros and Favier (93/3605).Organic solvent extraction of Se from digested animal tissue signifi- cantly reduced Br and As interferences on the determination of Se by RI-XRF in a simplified method developed by Tariq and Preiss (93/3189). The method was applied to a study of selenite and selenate distribution and elimination in mice (93/1712). Initial selenate excretion was greater than that of selenite and followed first order kinetics. Analytical methods for Se have been applied to studies of Se status in various disease states. Using ETAAS with Pd chemical modification Reglinski et al. (94/549) found patients with Graves' disease to have much lower plasma Se levels (630k 160 nmol I - ' ) than healthy individuals (119Ok 180 nmol I - ' ) .Sample deproteinization with TCA and HG-AAS was the technique applied by Cai er a/. (93/1238) to determine serum Se levels in cancer patients. Lower serum Se levels were found compared with healthy individuals. Beker et a!. (93/3981) found a significant difference in the serum Se levels between boys and girls in urban regions of Yugoslavia. 1.9.26. Silicon The performance of ETAAS and ICP-AES for the determi- nation of Si in serum of uraemic patients was evaluated by Wrobel et al. (94/6 12). To avoid contamination risks all analyses were performed in a clean room with a laminar flow air supply. Aqueous calibration was satisfactory for ETAAS but standard additions was required for ICP-AES.A DCP-AES method for Si in urine was described by Belliveau et al. (93/1096) in which urine was aspirated directly into the plasma. As matrix inter- ferences could not be eliminated by the addition of an ioniz- ation suppressor calibration standards prepared in an artificial urine matrix were necessary. Urine Si concentrations for ten randomly selected individuals ranged from 1.8 to 51.6 mg 1 - ' and were related to vegetable intake. Fahal et al. (94/611) also used DCP-AES to determine serum Si levels in patients on haemodialysis treatment. Serum Si was elevated in comparison with healthy individuals and showed a significant positive correlation with serum Al. A Ca( NO3) chemical modifier improved analytical sensitivity for the determination of Si in protein solutions by ETAAS in a method developed by Holden et al.(93/1042). 1.9.27. Silver For the determination of Ag in milk and bovine liver RMs by ETAAS Ohta et al. (94/227) used a molybdenum tube atom- izer. To prevent oxidation of the atomizer the Ar purge gas was mixed with H,. Digestion of samples with HN0,-H,02 and dilution with 0.5% NH,SCN as chemical modifier elimin- ated interferences from several major elements. a detection limit of 3.7 fg of injected Ag was reported. 1.9.28. Strontium A method for the determination of Sr in plasma and urine by ETAAS with Zeeman-effect background correction was devel- oped by Chaumard and Autissier (94/68) in which samples were diluted 20-fold with 2% HNO,. Analysis of samples from healthy subjects gave plasma Sr concentrations of 12.7-40 mg I - ' and urine concentrations of 3.2-78 mg I-'.1.9.29. Thallium A comparison of ICP-MS and Zeeman-eflect ETAAS for the determination of TI in biological fluids was made by Kershinik et al. (93/C1487). For the ETAAS procedure Pd was used as a chemical modifier. A detection limit of 1 mg I - ' was achieved. The detection limit for the ICP-MS method was 0.1 mg I - ' in diluted samples. A correlation of 0.999 betweenJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 119R the two techniques was found for the analysis of biological samples containing physiological concentrations of T1. 1.9.30. Tin Total Sn in NIES fish tissue and other biological RMs was determined by ID-ICP-MS in a method described by Okamoto (93/2299). After addition of a l18Sn spike solution samples were digested with HNO by microwave heating and the to an FI system enabled Li et ul.(93/3964) to separate Sn from complex matrices. The hydride was trapped onto a Pd coated L'vov platform and Sn atomized using STPF conditions. A detection limit of 7 ng for a 10 ml sample was achieved. The method was validated by analysing several RMs including NIST bovine liver. Using ETAAS Nakazaki and Shiroishi (93/1260) determined total Sn concentrations in whole blood and blood fractions from healthy individuals. 1 18sn . '"Sn ratio was measured. Hydride generation coupled 1.9.3 1. Uranides The suitability of ICP-MS for the determination of rare earth elements in biological samples was discussed in a general article by Kishi and Suzuki (93/2303).Shiraishi et al. (93/2449) described an ICP-MS method for the determination of Th and U in human tissues. Samples were digested in a PTFE-coated microwave digestion system. The accuracy of the method was demonstrated by analysing NIST bovine liver and tomato leaves SRMs. For the determination of Th in biological samples Yasuhiko et al. (93/2335) used ID-ICP-MS. The method could detect 1 ng of Th with reasonable precision when ','Th was used as the isotope tracer. 1.9.32. Vanadium Methods for the determination of V in biological samples by ETAAS often employ chelation and solvent extraction to minimize interferences and achieve the necessary sensitivity. For the determination of V in urine and animal tissues Yaman and Grucer (93/C1632) used chelation and absorption onto activated charcoal.Ashed samples were dissolved in HN03-HC10,. The V was chelated with 8-hydroxyquinoline and cupferron adsorbed onto activated carbon and determined by ETAAS. A direct ETAAS method for the determination of V in urine was described by Shuttler (93/3082). A spectrometer with a transversely-heated atomizer and longitudinal Zeeman- effect background correction was used for the determinations. The method had a limit of detection of 0.3 mg 1-' in undiluted urine which could be lowered further by using a repeated injection facility. A transversely-heated atomizer was also used by Sjostrom et a/. (94/555) to determine V in blood by LEAFS. Vanadium could be determined at picogram levels. Contamination from V in the graphite tubes was the limiting factor for the determination of V in normal blood samples.1.9.33. Zinc The development of MS techniques to measure stable Zn isotope ratios has enabled Zn absorption studies to be carried out in children and pregnant women. Amarasiriwaradena et a/. (93/2059) optimized sample pre-treatment for ICP-MS deter- mination of 70Zn:68Zn isotope ratios in body fluids and excreta from pre-term infants fed "Zn-enriched foods. Zinc in digested samples was extracted into CC14 with APDC and back- extracted into 1.2 mol I-' HNO for measurement. Complete evaporation of CCI was necessary to eliminate C1 interferences. Absorption and excretion of zinc was studied by Fennessy et al. (93/2504) in more than 120 subjects using FAB-MS to measure the stable isotopes. Isotope ratio measurements could be obtained from 1-5 mg samples with a precision of <2%.Average Zn absorption in a fasting state was 73%. Patterson et a/. (93/2132) modified a previously described method (Serfass et a/. A n d . Chim. Acta. 1986 188 73) by substituting HN03 for HCl in the final solution to remove the C1 interference on the measurement of "Zn . This modified method gave a limit of detection of 0.06 mg Zn. An automated micromethod for the determination of Zn in whole blood plasma and red cells by FI-AAS was developed by Burguera and Burguera (93/1182). Sampling rates of 120 30 and 20 measurements h - ' could be achieved for whole blood plasma and red cells respectively. D'Haese et a/. (94/377) determined Zn in serum directly by ETAAS with wall atomiz- ation and Zeeman-effect background correction.Ultrapure water was the only reagent used to dilute samples. Argon gas flow was maintained during atomization to attenuate sensi- tivity. An interlaboratory comparison of FAAS and colori- metric methods for serum Zn was conducted by Arnaud et a/. (93/3778). Linearity precision and correlation between the methods was acceptable but the colorimetric method gave a significant positive bias. A study to clarify the effect of smoking on maternal and foetal Zn status was undertaken by Kuhnert et a/. (93/3973). Zinc measurements were made by AAS. The results suggested that foetal Zn intake is normally related to maternal Zn status but is altered in pregnancies complicated by smoking. The non-protein fraction of Zn in human milk was determined by Arnaud and Favier (93/2714) by ultrafiltration through a cellulose acetate membrane and analysis of the ultrafiltrate by ETAAS.Ultrafilterable Zn values ranged from 0.46-84 mmol 1-'. Ackland et a/. (93/4042) measured by AAS Zn concentrations in the milk and stomach contents of pups from mice with the lethal milk mutation. The low levels of Zn indicated that the defect in this condition was the production of Zn-deficient milk. 1.10. Conclusions Fig. 1 shows the distribution of techniques used in the publi- cations covered by this review; it was compiled from the data in Table 1. Although AAS techniques still predominate it is interesting that publications using mass spectrometric tech- niques are now as common as those using ETAAS (or other ETA techniques). Flame AAS holds a respectable 14.9%.The most noticeable feature of the publications in this year's review is the large number of papers with the word 'on-line' in the title. This continues a trend noted in last year's review in which many of the formal publications covered this year first appeared as conference presentations. Part of the reason for this trend is the current fascination for using microwave heating for on-line digestion. For solids samples have to be slurried to be pumped through the system (93/2082 94/284 94/578). It is difficult to see why on-line digestion of slurries should be necessary when direct slurry sampling has been so well developed (93/1944). On-line microwave digestion of liquid samples for determination by CVAAS or HGAAS seems a more promising development (93/27 17 93/27 18 93/3924) as does photo-oxidation for Hg determination (94/422).A further important development is the use of FI sample pre- concentration procedures to enhance the sensitivity of FAAS (93/C1524 93/2121 94/267) and ICP-AES (93/3114 94/579). Inductively coupled plasma MS suffers from interferences for many of the elements that are of clinical interest. A logical development is the use of on-line procedures to remove interfer- ing species (93/2090 93/3224). Speciation was an early candi- date for the use of on-line techniques and is exemplified by recent applications (93/3084 93/3224). Much of the work has resulted from the continuing development of FI and the more recent introduction of commercial systems specifically for atomic spectrometry has accelerated the development of appli- cations.It will be interesting to see how this develops in the future. Is ear wax the clinical sample of the future for studies of occupational and environmental exposure (93/1118)? Watch this space!120R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 ICP-MS and other MS XRF FAES (1.1%) AS and E l HGAAS (2 ,s (14.9%) 'A-AFS (27 .8%) '.OYo) ICP-AES DCP-AES and MIP-AES (12.7%) CVAAS and CVAFS (2.8%) Fig. 1 Pie-chart showing the frequency of use of techniques in the publications covered by this review. 2. ANALYSIS OF FOODS AND BEVERAGES Simon Branch A summary of the published and conference papers covered in this review is given in Table 2. In comparison with last year's review (94/739) there is a smaller number of publications which address topics related to A1 and Se.There is still considerable interest in improving procedures for sample prep- aration and introduction. In addition there are more papers from Third World countries which report the levels of trace elements in foods and diets. 2.1. Sampling and Sample Preparation A review of procedures for sample preparation and handling by Delves (93/1140) states that ideally sample preparation con- verts the matrix to a form which during analysis minimizes any dependency of analyte response on variations in sample composition without either loss of endogenous analyte or accidental contamination. There are obvious practical limi- tations to achieving this ideal. However when contamination is to be minimized then simple and where possible direct determination of the analyte is recommended. If the sample matrix is a problem and more complex procedures are required care needs to be taken so that for example the digestion of diets for the determination of Hg or Se does not cause loss of these analytes by volatilization.In preparing samples for analysis blenders are frequently used for homogenization of matrices. Razagui et al. (94/104) washed blenders with a hot (80+ 5 "C) EDTA-citric acid solution before using them to homogenize samples of breakfast meals. Significant increases were observed in the levels of Cd Cr Cu Fe and Zn in samples homogenized in untreated blenders. 2.1.1. Direct determination of analytes The direct determination of Pb in cola beverages has been described (93/4074).Here 'direct' refers to the analysis of samples by ETAAS after extraction with La-HNO solution. The LOD was 9.77 ng ml-'. A quick method for the determi- nation of Pb in fruit juices was reported by Mirchi and Popadicova (93/1223). They hydrolysed orange juice samples with HNO for 5 min at 70°C followed by centrifugation for 30 min and analysis of the supernatant. The sensitivity was quoted as 0.016 mg 1-'. A French paper by Gruny (93/3483) reported the determi- nation of Pb in wine and alcoholic media using an autoprobe system with ETAAS. The LOD for this direct sampling method and Helen Crews was 1 pg I-' and there was linearity in the range 0-50 pg 1-' of Pb. Aluminium and Pb were measured in port wine by ETAAS (93/3396).To minimize contamination port samples containing a deposit were filtered and the filtrates were diluted with 0.2% m/v HNO (1 +24 and 1 +9 for A1 and Pb respectively). Standards were not matrix matched but an Mg-Pd chemical modifier was added and for Pb determi- nation a Triton X-100 solution was added to samples and standards. The LODs for samples of port wine prior to dilution were 40 pg 1-' for A1 and 19 pg 1-' for Pb. The direct determination of trace elements in low alcohol fermented beverages by ICP-AES after a 10-fold dilution with 5% HCl mixed with an appropriate amount of Sc as internal standard has been reported (93/2241). For Ba Ca Cu Fe Mg Mn Ni Si Sr and Zn the RSDs ( n = 10) ranged from 0.6 to 5.3% with recoveries of 95-1 10%.The results agreed with those obtained after samples had been wet or dry ashed. Interferences caused by Ca Cu Mg and Mn were tabulated and correction coefficients given. Bottled drinking water was measured by ETAAS for Al As Cd and Pb (94/128). The water samples were acidified with 1% HNO for As Cd and Pb determination. A chemical modifier 25% HN0,-0.5% NH,H,PO was added for Cd and Pb determinations. Arsenic was determined after addition of a modifier solution containing 80 pg ml-' Ni" 1 mgml-' Fe"' and 800 pg ml-' Cu" in 40% HNO,; the next day 15 mg ml-' Ba" was added and the solution was analysed. Aluminium was determined in HN03-20% citric acid in the presence of 100 pg ml-' Pd. An analytical procedure has been developed for the direct determination of Cu in butter (94/64).Samples (1 g) were readily dissolved in a butylamine-H,O mixture (85 + 15) after cleaning the butylamine on activated alumina columns to remove contaminating metals. Portions (30 pl) of the sample solution were analysed by ETAAS. 2.1.2. Preconcentration In a conference presentation (93/C1583) Hodge and Laing described the use of ion exchange with ICP-MS to measure 226Ra in water samples. This method was investigated as an alternative to concentration and separation of the analyte from the samples and measurement of the daughter product (radon) by scintillation counting. This latter procedure could take 2-3 weeks with a counting time of 8 h. In contrast the use ofJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 2 FOODS AND BEVERAGES 121 R Element Matrix Technique; atomization; analyte form* A1 Beverages water AA;F;L A1 Beer A1 Port wine A A;ETA;L A A;ETA; L .. - - A1 Diets milk powder 3 A1 Tap water As Fish As Mussel As Vegetables As Foods As Foods. water C Milk C Apple cider vinegar C Honey Ca Water M S;IC P; L A A;ETA; L A A; H y; L A A; ETA; L A A;H y; L AA;ETA;L AA;CV;L AF;CV;L A A; H y; L MS;-;L AE;ICP;L MS;-;L MS;-;L AA;F;L Cd Foods AA;ETA;- Cd Codfish powder milk A A;ETA;S powder Cd Rice AA;F;L Cd Soy sauce AA;F;L Cd Mussel AA;ETA;L Cd Waters AA;Vapour generation;L AF;Vapour generation;L Sample treatmentlcomments A1 was determined in water tea-leaf digest tea and coffee infusions by on-line FI-FAAS. Determinations could be performed down to 75 ng ml-. Results of a collaborative study were reported.The LODs and determination were 3.4 and 6.5 pg I - ' respectively A1 and Pb were determined using an STPF after 1 +24 and 1 + 9 dilution respectively. This procedure gave LODs in the undiluted sample of 40 pg 1-' A1 and 19 pg I - ' Pb determination in food were reportedly in poor agreement; 1 1 out of 24 laboratories reported difficulties. Best results were obtained by those laboratories using wet ashing in conjunction with ETAAS dialysis solutions and tap water by ICP-MS and ETAAS was similar Lyophilized fish was microwave digested with HNO using V 2 0 as catalyst. The LOD was 0.146 pg I - ' Use of graphite cloth ribbon inside ETAAS tubes was discussed. To obtain good reproducibility it was essential to fix the position of the cloth inside the tube Samples were digested using HNO and V,O as catalyst in a microwave bomb.LODs were approximately 0.02 pg g - ' As was determined using pyrolytically coated graphite tubes and platforms. The wavelength of analysis was 193.7 nm. The effects of cooking on levels of As in beef poultry and fish were reported Methods used for the speciation of organometallic compounds of As Hg and Pb were described Results of an IUPAC collaborative study of A1 Quality of results obtained during the analysis of Residual C was determined to assess the effectiveness of dissolution procedures. The C I 193.091 nm line Sc I1 424.683 nm line (as reference) and Myers-Tracy signal compensation were used. Optimum working conditions were found to yield an LOD of 2.4 mg dm- and RSD of 2% Application of stable C isotope ratio analysis to the detection of corn-derived acetic acid in apple cider vinegar was described.The method was based on natural variations in the 13C:'zC ratio adulteration. Of 160 samples analysed 79 were identified as adulterated Ca and Mg were coprecipitated with Zr(OH) the precipitate filtered off and dissolved in the presence of La (0.25 mg mi-' with respect to the sample) and analysed by FAAS absorption and suppressed the volatilization of the analyte during ashing due to the formation of the oxide described. The sample powder was spiked with standard lyophilized homogenized and analysed For the determination of Cd and Ni it was found that room temperature treatment with HNO and H202 gave similar results to those achieved with more extreme conditions e.g.pressurized digestion 1 -( 2-pyridylazo)-2-naphthol-Ni" and analysed by FAAS with micro-injection sampling. The LOD was 1.05 ng ml-' at pH 10 (in Chinese) Cd concentrations in a number of species of Sicilian mussels were determined and found to lie in the range 39- 137 pg kg-' (in Italian) Vapour generation of Cd using sodium tetraethylborate was performed using a conventional continuous flow reactor. The LOD using AF was 20 ng 1-' C isotope ratios were used to investigate honey Addition of 0.5 I min-' O2 reduced background Method using solid sampling Zeeman ETAAS was Cd was coprecipitated from soy sauce using Reference 9313256 9313303 9313396 9314125 9416 10 9312682 9313937 941129 941425 941480 9312048 9312954 9312996 9312191 9311 136 9312 188 9313 194 9313952 941 184 94/582122R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 2 (continued) Element Cd c o Cr Cr Cr c u c u Matrix Tea Mineral water Mineral waters Water Foods Salmon Cocoa powder Technique; atomization; analyte form* A E;I CP;L AE;ICPL AA;ETA;L AA;F;L A A; ETA; L AA;F;L c u Artichokes diets tomato AA;F,air-C2H2;Sl leaves cu Salt water cu Foods c u Margarine c u Butter AA;F:L AA;ETA;L AA;-;L A A;ETA; L c u Chewing gum vegetables AA;F;L Eu Foods A A;ETA; L Fe Cocoa powder AA;F;L Fe Foods AA;ETA;L Fe Chewing gum vegetables AA;F;L Fe Infant diets AA;-;- Garlic ginseng water A A;ETA;L Ge Sample treatment/comments Continuous flow HG was studied as a means of gaseous Cd introduction to ICP-AES.Didodecyldimethylammonium bromide vesicles were used to improve the generation of Cd species using NaBH as reducing agent.The LOD was 1 ngml-' Preconcentration factors of 100 were achieved by using ion exchange prior to ICP-AES Cr"' was chelated with 0.1 mol I-' 8-hydroxyquinoline in CH,OH extracted into IBMK and determined by ETAAS. For total Cr using the hot injection method of preconcentration and Mg(N03)2 as chemical modifier an LOD of 39 ng I-' for a 100 pl injection was achieved On-line preconcentration FI-FAAS with an activated alumina column was used to speciate Cr"' and Cr"'. The LODs were 1.0 and 0.8 pg I - ' for Cr"' and Cr" respectively Samples were dry ashed in a muffle furnace then analysed by ETAAS using Mg( NO,) as chemical modifier. The LOD was 0.28 pg I-' for a 20 11 injection CuO active ingredient of an algicide was not found at elevated levels in salmon farmed in pens treated with the algicide Cocoa powder was slurried in 10% HN03 injected into a double FI manifold merged with a stream of concentrated HNO and digested under stopped flow conditions in a resistively heated oven incorporated into the FI manifold. Various adaptations of the design were discussed Samples were digested on-line by microwave then transported to the AA spectrometer as slurries.A 1 + 1 mixture of concentrated HN0,-H202 was used both for digestion and transport. Using the method more than 15 samples h-' could be analysed Cu was desorbed from the cotton using an HCI-HNO mixture (in Chinese) Cu Fe and Sn were digested using a novel dissolution device.The H20 produced during digestion was removed using reflux. Digestion times and volumes of oxidizing acid were minimized cycles the first with 5 ml of HNO the second with 30% H202 (in Italian) solution of purified butylamine cooled and a 30 p1 aliquot analysed by ETAAS. A relatively high LOD of 5 pg g-' was quoted (in French) their Cu Fe and Mg complexes following extraction and then purification and separation by partition chromatography (in Japanese) Eu La and Yb were determined by ETAAS using a tungsten-lined furnace. The LODs were 37.8 pg 7.85 ng and 4.04 pg for Eu La and Yb respectively. Interferences were reportedly negligible (in Chinese) Xanthate cotton was used to preconcentrate Cu. The The sample (1 g) was microwave digested using two Butter (1 g) was melted homogenized with an 85% Chlorophyll and chlorophyllin were determined as See Cu ref.93/C 1586 See Cu ref. 9313080 See Cu ref. 941190 The authors of the study suggested that the increase in daily Fe intake obtained by cooking foods in Fe utensils would satisfy the Fe requirements of infants Ge hydride was generated using an FI system and transferred to a Pd-coated furnace tube preheated to 400 "C. The sample was then atomized at 2500 "C. The LOD was 4-30 ng I-' depending on the concentration of HCI used. Strategies to overcome interferences were discussed Reference 941602 941161 93/C1634 9312896 9314027 9311 102 93/C1586 9 3/208 2 9312150 9313080 9313688 94/64 941 190 9313179 93jC1586 9313080 941 190 94/502 9313227JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 123R Table 2 (continued) Tec hniq ue; atomization; Element Matrix analyte form* Sample treatment/comments Reference 9311005 9311 199 9311239 9312 163 9312677 9313436 9313986 941286 94/423 941480 HE Cod MS; 1CP;L Collaborative exercise indicated that results obtained by ICP-MS were influenced by the chemical species of Hg present. ICP-MS results were approximately half the value obtained by CVAFS using the same sample preparation protocol Japanese) with an HCl-NaCI solution and reduced to elemental Hg by NaBH prior to determination by CVAFS. The LOD was 5.15 pg 1-' (in Chinese) Hg was determined in drinking water using ICP-MS and a direct injection nebulizer Standard method for analysing Hg in water and waste water was collaboratively tested (in German) Samples were digested using methanolic KOH derivatized with NaB(C,H,) cryogenically trapped and then separated by GC.The LODs were 4 pg of Hg for methylmercury and 75 pg of Hg for labile Hg" Hg was speciated in 229 samples representing 15 fish and several invertebrate species. In all the samples >95% of the Hg was present as methylmercury Methylmercury was extracted as the bromide from fish samples using CHCI and determined using CVAAS. No matrix effects were observed. The LOD was 25 ng of Hg as CH,Hg' Samples were wet digested by K,Cr,O in the presence of dilute H,SO,. An air condenser was used to reflux vapours released during boiling of the mixture. Good recoveries were reported AF;CV;L A A;CV;L AF;CV;L Method for digesting fish samples was described (in Hg was concentrated on xanthate cotton desorbed See As ref. 941480 Hg Fish HE Water Hg Water Hg Water Hg Fish M S;IC P; L AA;CV;L AA;-;L Fish marine invertebrates AF;CV;L Fish A A;CV; L Baby foods seafood AA;CV;L Foods water A A;CV;L AF;CV;L A A;H y; L MS;-;L Fruit vegetables AA;CV;L A method with an LOD of 0.1 pg kg-' was described (in Japanese) I vapour introduction was used to determine lz9I in contaminated vegetables.The approximate LOD was 1.4 ng kg-' fresh mass of vegetable '''1 was determined in UK rivers using ion exchange with XRF to estimate yield See Eu ref. 9313 179 See Ca ref. 9312191 See Cu ref. 941190 Mo was determined in rice using CaCl as chemical modifier. La-coated tubes were used and the wavelength of analysis was 313.3 nm.The LOD was 0.76 ng ml- ' (in Chinese) See Co ref. 941 16 1 See Cd ref. 9313194 See Cu ref. 9313688 Samples were digested in HN0,-HCI0,-HF ( 8 + 1 + 2) to dryness the residue redissolved in dilute HNO and diluted to 50 ml with H,O. A mixed Ca-Pd chemical modifier was used (in Chinese) Organolead species were extracted from enzymically digested samples using dithizone. Following derivatization using a Grignard reagent the species were separated and detected by GC-AAS. The LODs were 0.07-0.2 ng g - ' of Pb Samples were hydrolysed in HNO centrifuged and Pb determined in the supernatant using AAS at 217 nm. The sensitivity was quoted as 0.016 mg I - ' (in Czech) Pb was determined using Pd-Mg( NO,) as chemical modifier. Two ashing steps were required to completely mineralize the slurries. The LOD was 0.6 pg 1-' were extracted and derivatized using a Grignard reagent.The sample solutions (25 mm3) were injected onto the column and the solvent removed using an He purge. This preconcentration protocol yielded an LOD of 0.1 ng I - ' of Pb Dithiocarbamate complexes of ionic organolead species 94J5 19 9311008 931171 7 9313 179 9312 19 1 941 190 931401 5 941161 93/3 194 9313688 9312239 9311 139 223 630 9312069 Vegetables M S;I C P; L I Drinking water X R F ;-;- - La Mg Mg Mo Foods A A; ETA; L Water AA;F;L Chewing gum vegetables AA;F;L Rice A A;ETA; L Mo Ni Ni P Mineral water AE;ICP;L Rice AA;F;L Mussels tea leaves Margarine AA;-;L A A; ETA; L Pb Seafood AA;-;L Pb Orange juice Pb Mussel A A ;-; L AA;ETA;Sl 9 3 i 93/c Pb Water AE;M IP; L124R Table 2 (continued) JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 Element Pb Water Matrix Technique; atomization; analyte form* Sample treatment/comments Pb CRMs water AA;ETA;L Pb Wine AA;ETA;L Pb Cattle feed milk MS;ICPL Pb Rice flour and wheat flour AA;ETA;Sl Pb Water MS;ICP;L Pb Foodstuffs A A;ETA; L Pb Wine AA;ETA;L Pb Foods water Pb Soft drinks Ra Drinking water Sb Mushrooms Se Diets Si Mineral water Sn Foodstuffs V Foods V Foods Yb Foods Zn Milk Zn Zn Liver milk powder Human milk MS;-;L Samples were spiked with stable ,%Pb standards ethylated the derivatives extracted by heptane and detected and quantified by GC-MS. The LOD was 0.3 ng g - ' modification by Pd and citric acid. The LOD was 0.1 pg I - ' for a 10 p1 injection Method using STPF ETAAS was developed using Samples were analysed using an autoprobe.No sample preparation was required. The LOD was 1 pg 1 (in French) Analytical protocols and quality control procedures used during a food contamination crisis were described Flour samples were boiled in a water-bath to give stable suspensions containing 2% m/v of the sample. The LOD was 1.8 ng ml-' (in Chinese) Pb was determined by external calibration using 'O'Bi as internal standard. The principal sources of Pb in tap water were copper pipe or solder Combination of 6 pg of Pd and 15 pg of Mg(NO,) was proposed as chemical modifier for Pb determinations. This combination gave a wide linear Calibration range Wine was diluted ( 1 +4) with a modifier solution containing 0.25% HNO 0.25% NH,H,PO and 0.0125% Mg(N03)2.Standards were matrix matched for ethanol content. The LOD was 6.2 pg 1 - ' See As ref. 941480 A A;CV;L AF;CV;L AA;H y;L MS;-;L AE;ICPL M S;I C P L AA;H y; L A A; ETA; L A A;ETA;L AA;ETA;L A A;ETA; L AA;F;L AA;ETA;L A E; I C P L MS;ICP;L A A; ETA; L Plumbane was generated using continuous flow HG-ICP-AES with a K,Cr,O,-lactic acid medium. The LOD was 2 ng ml - ' 226Ra was determined by ion-exchange ICP-MS. The described method gave an LOD of 1 pg 1- ' and recoveries of 97 f4% negatively correlated with Ag As Cd Hg Ni and Pb concentrations. It was proposed that this was due to competition for the same available chelating ligands in the fungi Samples were digested by HNO in a PTFE bomb a few drops of H202 added and the solution diluted to 5 ml.The resulting solution was analysed at 196 nm using Zeeman-effect ETAAS and Ni" as chemical modifier. The LOD was 10.5 ng ml-.' A Ca-based chemical modifier and tungsten-coated tubes were used (in Chinese) See Cu ref. 9313080 Foods were digested in a microwave oven using Sb concentration in 14 species of mushroom was HNO,. NH,OH was added to the digest and V determined using Ca as chemical modifier and STPF ETAAS with pyrolytic graphite coated graphite tubes (in Chinese) disalicylohydroxamic acid complex with a 0.5 mol I - tributyl phosphate solution in IBMK. The LOD of the method described was 19 ng ml-' V was extracted as the V( V)-5,5'-methylene- See Eu ref. 9313 179 Dry ashing and wet dissolution methods for the decomposition of milk samples were compared based on Zn recovery and residual C concentration. Without an ashing aid Zn losses were observed during dry ashing at high temperatures materials using ID-ICP-MS.The LOD was 0.06 pg of Zn investigated as part of a study of the ultrafiltration step during the determination of non-protein bound Zn in human milk Zn stable isotopes were determined in biological Zn contamination and Zn membrane binding were Reference 9312424 9313233 9313483 9313542 9313564 93/36 17 9313955 94/25 1 941480 941597 93/C1583 941532 9212889 941465 9313080 9311242 941345 9313 179 9312049 9312 132 93/27 14JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Table 2 (continued) 125R Element Matrix Technique; atomization; analyte form* Zn Brine common salt water AA;-;L Zn Beer wort A A;ETA;L Sample treatment/comments Ultrasound was used to decompose Zn organic compounds present in the samples (in Russian) Results of a collaborative study of Zn determination in beer and wort were described. The LODs were 3.5 and 5.3 pg 1-' for beer and wort respectively Reference 9313296 941427 MULTI-ELEMENT ANALYSIS Certified Reference Materials Various CRMs; rice flour citrus leaves dogfish liver sea- water Various (6) CRMs Various (45) CRMs; milk powder pepperbush tea leaves Various (29) CRMs Various CRMs; bovine kidney and ( 5 ) muscle rye flour wheat (8) flour Various CRMs M S;IC P; L AA;ETA;S,Sl MS;ICP;S AA;ETA,F;- AA;ETA;L AE;ICP;L Square wave voltamet ry;-;L AA;ETA;L AA;F;L AE;ICP;L MULTI-ELEMENT ANALYSIS Foods .. -_- Various Foods 1 Various Foods MSiICPi- (66) Various Vegetable oil ( 5 ) Various Foods Various Ginseng Various Fat-rich foods AA;ETA;L M S;I CP; L Various Animal feed fertilizers M S;IC P; L Various Foods MS;ICP;- Various Meat (8) AA;-;L Addition of N to the nebulizer or coolant gases was shown to attenuate a number of polyatomic interferences including ArCI' ClO+ MO' and ArO'.Simplex optimization was used to optimize the spectrometer operating conditions Solid and slurry sampling for ETAAS were investigated. The best agreement with reference values was obtained using the slurry technique (Ag Cu Fe Mn Pb Zn) introduction. Calibration was achieved based on individual element sensitivities derived from matrix matched standards. Fairly good agreement with the reference values was observed Preparation and homogeneity characterization of ten CRMs were described Samples were pressure digested with HNO in PTFE ( 180 "C) and quartz (280 "C) vessels.Excellent results were reported (Cd Cr Cu Pb Zn) Four closed-vessel microwave digestion procedures were investigated. The methods involved either wet digestion with HNO alone or in conjunction with HF H,02 or HCIO,. Each of the methods gave acceptable results (B Cd Cu Fe Mn P Pb Zn) Laser ablation was applied to solid sample Review with 23 references of sample preparation Various applications of ICP-MS in food analysis were procedures for a number of matrices discussed including isotope ratio analysis in micronutrient absorption studies and semi- quantitative analysis for investigating migration of chemicals from food packaging tetrahydrofuran) were introduced into the furnace tube by means of an aerosol deposition system.The elements were determined simultaneously using multi-element ETAAS (Cd Cu Pb Sb TI) from food samples prior to closed-vessel microwave digestion with HNO Water or oil samples ( the latter diluted in Supercritical fluid extraction was used to extract fat Ginseng plant was profiled for a number of elements Three microwave dissolution procedures were investigated. The most promising involved pressurized dissolution in PTFE-lined vessels. Heavy metals were determined in foods containing up to 98% fat Microwave dissolution plus ICP-MS were used to determine a range of trace metals ICP-MS and NAA were compared for the analysis of 50 foods. ICP-MS offered the greater sensitivity for the widest range of elements but suffered from blank problems when low LODs were required in solids Samples were ashed at 500-550 :'C using Mg(NO3) as ashing aid.The ash was dissolved in HCl and analysed using AAS (Cd Co Cu Fe Mn Ni Pb Zn) 9311022 93fC1369 93/27 13 94/34 9413 5 941603 9311 140 93fCl366 93/c 1434 93/C1545 93/1708 9312 184 9312201 9312439 9313 180126R Table 2 (continued) JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 Element Various Rice Various (4) Soybean Matrix Various (15) Ginseng Various (8) Foods orange juice Various ( 11 ) Foods Various Foods Various( 8) Foods Various (6) Rice tea wheat Various (4) Peanut oil MULTI-ELEMENT ANALYSIS Beverages Va rio us Orange juice Various Water Various (10) Low alcohol beverages Various (7) Water Various Cork stoppers ( 5 ) Various Foods orange juice (8) Various Milk ( 1 5 ) Technique; atomization; analyte form* Sample treatment/comments XRF;-;S A A;ETA,F;L AE;ICP;L AE;ICP;L AA;-;L A A;ETA; L AE;F;L A E;I C P;L Samples were soaked in 65% HNO digested in HN0,-HC104 (3 + 1 ) and redissolved in 50% HCl.Portions (10 pl) were placed on a tungsten vaporization coil situated in an Ar purged chamber. The coil was used to dry and vaporize the sample. LODs varied from 0.03 ng (for Mg) to 2.5 ng (for Nd) Samples were dried milled and homogenized prior to analysis. A similar preparation was used for synthetic standards prepared from cellulose impregnated with the analyte elements. The LODs were 5 2 5 and 2 pg g-' for Cu Fe Mn and Zn respectively (Cu Fe Mn Zn) Samples were digested with HNO or HN03-HC104 (in Chinese) ICP-AES was used in conjunction with in-beam neutron capture prompt gamma-ray activation analysis.Losses of B during digestion were investigated (B Ca Cd C1 H K Na S) Optimum conditions for the determination of 11 elements by ICP-AES were established (in Chinese) Four methods of dry ashing were investigated. The best results were obtained using wet ashing with far-IR as the heat source Laboratory blenders were identified as a significant source of contamination in food analysis. A chemical clean-up e.g. with 2% EDTA-2% citric acid at 85 "C was recommended before use (Ca Cd Cr Cu Fe Mg Pb Zn) Synthetic standards were prepared by mixing starch with the analyte elements.Samples and standards needed to be mixed with powdered graphite (2 + 3) prior to analysis (Ba Co Cu Fe Pb Zn) (In Chinese) Contamination of peanut oil with Cu Fe Pb and Sn from factory processing was shown to accelerate oxidation. The valence state had a significant effect on the induction of lipid peroxidation (Cu Fe Pb Sn) (in Chinese) AE;ICP,S AE; I CP; L AE;ICP;L A E;IC P; L AA;F;L AA;ETA;L A E;ICP;L AA;-;L Artificial neural networks were used to analyse ICP- AES data in order to detect adulteration of orange juices Ultrasonic nebulization allowed the determination of a range of elements at detection limits down to 2.5 pg I - ' (for Cd). Long-term stability in runs of up to 18 h was achieved Samples were diluted ( 1 +9) in 5% HCl mixed with Sc internal standard and analysed using ICP-AES.The results agreed with those obtained by dry ashing and wet digestion (in Chinese) (Ba Ca Cu Fe Mg Mn Ni Si Sr Zn) Water (250 ml) was adjusted to pH 5.5 to 6.5 and mixed with a 0.05% acetone solution of 5-( 2'-carbomethoxypheny1)azo-8-quinolinol. IBMK was added and the solution shaken prior to FAAS analysis of the organic layer. LODs ranged from 0.07 to 0.38 pg 1-' (Co Cr Cu Fe Mo Ni Pb) The corks were digested in PTFE apparatus using HN0,-HCl-HF evaporated to dryness re-dissolved in HNO and analysed by ETAAS using an STPF and suitable chemical modifiers (Al Cd Cu Fe Pb) ICP-AES was used in conjunction with in-beam neutron capture prompt gamma-ray activation analysis. Losses of B during digestion were investigated (B Ca Cd C1 H K Na S) Trace element concentrations in milks from Egyptian animals were related to environmental factors such as site grazing plants and soil contamination Reference 9313242 93/3487 93/3535 9313614 9313705 9313937 94/ 104 9411 15 941544 931C 1374 9312208 9312241 9313 103 9313239 9313614 9314025JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 127R Table 2 (continued) Technique; atomization; Element Matrix analyte form* Sample treatment/comments Reference Various ( 5 ) Human milk Various (6) Rice tea wheat Various ( 12) Water Various (7) Water Various (5) Evaporated milk infant formulas XRF;-;S 94/23 1 AA;F;L 941346 A E; IC P; L Variation in concentrations of five major elements 9314082 during the first 5 months of lactation was investigated.The concentrations decreased over the period studied (Ca K Mg Na P) with the analyte elements.Samples and standards needed to be mixed with powdered graphite (2 + 3 ) prior to analysis (Ba Co Cu Fe Pb Zn) (In Chinese) The analyte elements were coprecipitated using Al(OH) filtered through a 0.4 pm pore membrane dried at 70°C and analysed by EDXRF. The method was not suitable for sea- water analysis Application of poly(chlorotrifluoroethy1ene) resin trace metal preconcentration was described. Metals were complexed with either 8-quinolinol Bismuthiol I1 or 5-sulfonic acid then collected on a column packed with the resin. The metal complexes were eluted directly into the nebulizer of an AA spectrometer (Ag Cd Cu Fe Mg Ni Zn) added to 2 g of sample in a polystyrene test tube.The tubes were capped and heated at 55 "C for 6-18 h. The digests were diluted to 10 ml with water and analysed. The LODs were 21 43 6 63 and 73 ng g - ' for Al Cu Mn Mo and Sn respectively (Al Cu Mn Mo Sn) AE;ICP,S Synthetic standards were prepared by mixing starch 9411 15 20% citric acid (0.5 ml) and HNO ( 3 ml) were AA;ETA;L 941423 *Hy indicates hydride and S L G and SI signify solid liquid gaseous or slurry sample introduction respectively. Other abbreviations are listed elsewhere. ICP-MS with ion exchange reduced the analysis time to 3 min and the method met the required LOD of 1 pg 1-'. On-line preconcentration with FA AS was described by Welz et al. (93/C1524). The use of DDC for complexation with solid sorbent extraction was straightforward for water samples but wine samples needed to be digested with acid prior to com- plexation of Pb.Trace Cu in water and salt samples was measured by FAAS after concentration on xanthate cotton (93/2150). For salt a 4 g sample was boiled in H,O the mixture was filtered and the precipitate washed with hot H20. The filtrate was diluted to 100 ml (H,O) and a 50 ml portion mixed with 1 drop of concentrated HNO and 0.2 g of xanthate cotton. The mixture was stirred for 5 min the cotton was collected and the Cu desorbed with 1 ml HC1-0.5 ml HNO by boiling for 5 min. The cooled solution was diluted to 10 ml prior to determination of Cu. Calcium and Mg in tap water and environmental waters were coprecipitated with Zr and determined by FAAS (93/2191). Recoveries were better than those obtained using direct atomization of the samples.Heavy metals were determined in drinking and bore well waters containing 2-500 pg 1-' of the metals using FAAS (93/3103). Preconcentration using chelation (0.05% acetone solution of 5-( 2-methoxycarbonylphenylazoquinolin-8-01) and solvent ex- traction with IBMK was achieved for Co Cr Cu Fe Mo Ni and Pb. Aluminium was added prior to the chelation phase to remove the interference from on the extraction of Pb and from Po,,- on the extraction of Mo. Recoveries were generally better than 95%. The LODs were 0.07-0.38 pg 1-' and a 30-fold preconcentration was obtained using the chosen aqueous to organic phase ratio. Other workers (94/346) have used PCTFE [poly(chlorotrifluoroethylene)] resin to adsorb complexes of trace metals from tap waters.The retention capacity of the resin was greater for quinolin-8-01 and bis- muthiol I1 complexes than for 8-hydroxyquinoline-5-sulfonic acid complexes. By judicious use of pH and appropriate eluants a column method using 1 g of resin was developed for direct introduction of the organic eluates into a nebulizer for measurement by FAAS of Ag Cd Cu Fe Mn Ni and Zn. Cobalt Mo and V were determined in Austriun mineral waters by I CP-AES after ion-exchange separation and preconcentration (94/161). The samples were acidified with concentrated HCl and the elements adsorbed as thiocyanate complexes and then eluted with HC10,-HCl. Recoveries for the three analytes were about 99% at a concentration of 1 pg 1-' and an enrichment factor of 100 was achieved. Two publications report the use of preconcentration with FAAS.for the analysis offood samples.Cadmium was determined in soy sauce after coprecipitation with 1-( 2-pyridylazo)-2- naphthol-Ni" (93/3952). The LOD of the proposed method was 1.05 x lo- pg ml-' at pH 10. Good reproducibility and accuracy was reported with no interferences. Bagur et al. (94/345) used 5,5'-methylenedisalicylohydroxamic acid to selec- tively extract Vv from foods and petroleum crudes. When the 0rganic:aqueous phase ratio was 0.2 the LOD was 0.019 pgml-'; when the ratio was 0.05 the LOD was 0.006 pg m1-l. The RSDs were 1.5 to 3%. 2.1.3. Digestion In two papers by Chmilenko and Baklanov ultrasonic radiation was used as a digestion aid for the determination of Fe and Zn (FAAS) and Cd Cu and Pb (ETAAS) in dairy products (93/3201) and for Zn (FAAS) in water brine and common salt (93/3296).Samples were digested with HNO or HN0,-HCI under ultrasonic radiation at 22 kHz for 2 min. For FAAS digests were diluted prior to determination. For ETAAS the digests were mixed with NH,NO solution then diluted before determination of the metals. Chung and Tsai (93/3080) described a simple digester equipped with a reflux tube packed with glass beads to help condense acid vapour and to separate water vapour from decomposition gases. Experimental results from the digestion of canned guava drink coffee milk pow-128R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 dered milk canned mushrooms lychees and herbal jelly showed that 30% HzOz (9ml) or 65% HNO (5ml) was enough to complete the digestion of liquid samples (10 ml) or solid samples (10 8).For determination by ETAAS after heating the digests were diluted with 2% HNO for Cu and Fe and with 1 % oxalic acid for Sn. Recoveries were 95-104% with RSDs of 3.3-3.5%. There was no contamination during digestion because the system is almost completely closed. Several papers report compurisons of digestion procedures. Vollrath et a/. (93/3245) compared dissolution procedures for the determination of Cd and Pb in plastics. The analysis of plastics which may be in contact with foods is an area of increasing interest to the analyst and so this publication is included here. A variety of plastics were digested using either an oxygen flask combustion (OFC) or a microwave digestion procedure. These two methods were compared with a conven- tional wet ashing method.Measurements obtained by FAAS were verified using inverse voltammetry. Both the OFC method and the microwave digestion were rapid and cost effective dissolution procedures. Four closed microwave digestion procedures were evaluated for use with biological samples when determining B Cd Cu Fe Mn P Pb and Zn by ICP-AES FAAS or ETAAS (94/603). In addition the results from microwave methods were com- pared with data obtained from dry and wet ashing methods. A total of 18 RMs were tested. Two of the microwave methods were for botanical materials the difference being that one method included a hot-plate digestion with HF. The other two microwave methods were for milk total diet and mussel and had different power and time settings (which also varied within each method depending upon the type of microwave oven being used).The results provided quantitative recoveries for most elements with precisions of )3-15% RSD. However digestion with HNO alone was not sufficient for samples containing Si02 and/or fat. Iron content was low in samples containing SiOz but the post-microwave treatment with HF overcame this problem. For samples containing fat accurate and precise results were obtained using HN0,-H202 and Microwave procedures for ,fat-rich foods were compared by Dunemann and Meinerling (93/2184). Foods with up to 98% fat were studied. A pressurized dissolution technique in PTFE- lined vessels was the most promising. Margarine (1 g) was digested using microwave heating with HNO (5 ml) using a maximum of 50% power over 40 min followed by the addition of H20 (2 ml and re-heating at a maximum of 70% power over 27 min for the determination of Cu and Ni (93/3688).Mean values for Cu (12.3% RSD) and Ni (2.01% RSD) in margarine were approximately 200 and 80 ppb respectively. Japanese workers (93/3937) have reported that wet ashing with far-IR heating was superior to heating in a commercial microwave oven and better than conventional wet and dry ashing methods for digestion of food materials. Two papers by Krushevska et a!. report the results of measurements by ICP-AES after various decomposition pro- cedures. The residual C content (RCC) was used to evaluate the effectiveness of decomposition procedures and the determi- nation of the RCC is detailed in reference 93/2048.Optimum working conditions were found with an LOD of 2.4mg 1-' and 2% RSD. In the second paper (93/2049) the determination of Zn in milk by ICP-AES is described following high-pressure ashing digestion in a programmable ashing furnace and dis- solution in three commercial microwave digestion systems (open microwave low pressure and medium pressure dissolu- tion). The RCC varied and could be reduced by optimizing digestion parameters. However the presence of C did not affect Zn determinations and any one of the dissolution procedures studied could be employed. 2.1.4. Direct solids and slurry sampling A good review of direct solids and slurry analysis using ETAAS has been published by Miller-Ihli (93/1944).The two methods HNO,-HClO,. were defined as follows direct solids analysis - the solid is placed directly in the furnace; slurry analysis - the sample is prepared as a slurry or suspension. The review compares the two methods and concludes that regardless of the approach chosen a systematic approach to sample homogeneity cali- bration and furnace optimization is essential. Hofmann et czl. (93/2188) have described a new approach to calibration for solid sampling with Zeeman E TAAS. They used two milk powder CRMs as the standards for Cd determinations in other different CRMs. The results were good and another experiment using lyophilized codfish powder spiked with different amounts of Cd was used to investigate the use of standard additions in order to make calibration independent of the CRM.The results obtained by iteration indicated that calibration for solid sampling could be independent of the standard matrix. In contrast Vinas et a/. (93/3543) found that aqueous standards with FAAS for slurried sumples (3% m/v) of flours from grains and legumes gave results which agreed with those obtained by conventional dry ashing followed by dissolution in acid. The slurry method was found to be a rapid procedure for the determination of Ca Fe Mg and Zn in flours. Similarly Pb in wheat and rice flour suspensions (2% m/v) was deter- mined by ETAAS (95/3564). 2.2. Developments in Vapour Generation Techniques Ebdon et al. (94/582) described three general categories into which existing methods for vapour generation fall.These are the generation of gaseous covalent hydrides (HG) the forma- tion of volatile chelates and miscellaneous techniques. In this review year four papers have described the use of CVAASfor the determination oftotal Hg. Cold vapour generation with AF has been used to analyse Hg in waters after preconcentration of the Hg on xanthate cotton (93/1239). An LOD of 5.15 pg 1-' was quoted with an RSD of 3.1% ( n = l l ) for Hg concentrations of around 0.5 pg 1-'. Methods for total Hg in fish (93/1199) and in seafood and other protein-rich products (94/424) have been reported. Taneka et a/. (93/1199) have also published an improved method for Hg for use with fruit and vegetables (94,619) which gave an LOD in the samples of 0.1 ppb. Microwave digestion with V,O and HNO was used by Navarro and colleagues for As determinution in fish (93/2682) and uegetahles (94/129) b y HGAAS.The LOD for fish was 0.146 pg g-' and for vegetables about 0.02 pg g-I. An auto- mated HGAAS system was used with HPLC for the determi- nation of As compounds in algae mussels and sea-water (93/1141). In a very thorough paper Tao and Fang (93/3227) have described the development of a methodfor truce and ultra-trace levels ofGe using FI-HGAAS. Germanium may be of consider- able interest in food and water samples owing to its potential function in the retardation of human ageing and inhibition of growth of cancer cells (Pang et a/. Yaowu Fenxi Zhuzhi 1990 10,300). Current methods were not considered sensitive enough for the determination of Ge in biological samples (a character- istic concentration range of 0.4-2pg 1-' was quoted for ETAAS using a 20 p1 injection).The use of an FI system coupled to a gas-liquid separator and Pd-coated graphite furnace enabled LODs for Ge of 0.004 pg 1 - ' (in 0.15 mol 1- ' HCl) and 0.03 pg 1-' (in 3 mol 1-' HC1) to be obtained. The method was used to determine Ge in garlic tap water (both analysed using 0.15 mol 1 - ' HCI) and ginseng (analysed using 3 mol 1-' HC1). The concentrations were 0.010 and 0.037 pg 1- ' for two tap water samples 0.0024 pg g- ' for garlic and 0.015 0.020 and 0.051 pg g-' for three ginseng samples; RSDs were 2-2.5%. Tamari et ul. (93/2195) determined Se in biologicul SRMs by HGAAS. Samples were wet ashed with HNO or HN03-HC10,. Selenium(v1) was reduced to Se'" by boilingJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 129R the sample with 6 mol 1-' HCl. The results obtained agreed well with those from fluorimetric analyses and NAA. The generation of volatile Cd species to enable the determi- nation of low levels of this element in aqueous samples has been described in two publications. Ebdon et al. (94/582) developed a continuouspow method for generution of Cd vapour bused upon the formation of volutile diethylcadmium using a water soluble derivatizing reagent sodium-tetraethylborate(rl1). Using a prototype AF detection system an LOD of 0.023 ng ml-' was obtained. Cadmium was measured in three drink- ing waters by both ETAAS and VGAFS and none was detected. The ability to determine very low levels of Cd in these waters has particular significance.As the authors noted the World Health Organization recommends and the European Community directs that Cd levels in potable water should be 65 ng ml-'. The water supply industry in the UK has a general requirement to determine species at one tenth of the maximum permissible level i.e. for Cd 0.5 ng ml-'. A different approach was used by Sanz-Medel et al. (94/602). They used the addition of surfuctant-organized media to an uqueous NuBH medium to form volutile Cd species. They described surfactant organized media as organized molecular assemblies (micelles and vesicles). These have been shown to alter chemical equilibria reaction rates and other important chemical features owing to their capacity to create a micro- environment for reactions at the molecular level.The authors found that didodecyldimethylammonium bromide (DDAB) favoured the generation of volatile Cd species from aqueous solutions at room temperature. Their proposed method using ICP-AES with DDAB and NaBH gave an LOD of 1 ng ml-' and was used successfully to determine Cd in tea infusions. Sanz-Medel et al. (94/597) have also investigated the deter- mination of low levels of Pb in soft drinks and some environ- mental samples using continuous pow plumbune generation with ZCP-AES. They found that a mixed oxidant system of K,Cr,O and lactic acid gave improved sensitivity (LOD 2 ng ml-') and precision (1.3% RSD) and a low interference level for the determination of Pb by HG-ICP-AES. 2.3. Speciation Studies Vela and Caruso (94/592) reviewed the potential of LC with ZCP-MS for truce metul speciation.Campbell et al. published their work on the influence of chemical species on the determi- nation of Hg using ICP-MS (93/1005). This work was described in last year's review as a conference presentation (( 92/C342). The speciation of Hg infish sumples was studied by selectively extracting organomercury compounds with an organic solvent and determining Hg by CVAAS through direct reduction in the organic solvent (94/286). Methylmercury was extracted as Br- (added as KBr) using CHCl,. Inorganic Hg was deter- mined directly in the residual aqueous phase using NaBH as reductant; the high level of Br- prevented the use of SnCl,. Total Hg was determined after digestion with HNO,-H,SO followed by reduction with SnCl,.Good agreement was found between the sum of the organic and inorganic concentrations and the measured total Hg content. The LOD for the total analytical procedure was 25 ng Hg (as CH,Hg+) per gram of wet sample. Two papers report the use of cryogenic GC for the determination of Hg species in fish samples with AAS (93/3436) and in edible fish and marine invertebrate tissues using AFS (93/3986). The latter publication concluded that for all the samples studied virtually all of the Hg (>95%) was present as methylmercury and that previous reports of lower values must have been biased by variation in the analytical techniques and in sample homogeneity. Gas chromatography was also used to determine organolead species in tap water (93/2069).Speciation of As Hg Pb and Sn compounds in fish samples has been described by Waldock (94/480). Total Hg was meas- ured using CVAAS. Organomercury was determined after extraction with toluene and back-extraction into a cysteine solution. Tin species were converted to hydride derivatives and measured by GC with FPD. Hydride generation AAS was used for As determinations whilst tri- and tetra-alkyllead species were extracted into KI and hexane and determined The organic and total P b in selected fresh and canned seafood products was determined (93/1139). Di- and tri-methyllead and di-and tri-ethyllead were extracted with diphenylthiocarbazone from enzymically hydrolysed samples. Derivatives were formed by Grignard reaction prior to GC-AAS. Tetraalkyllead was extracted from the hydrolysates with hexane.Total Pb was determined by reductive coprecipitation with Pd in the pres- ence of ascorbic acid after digestion with HN0,-HClO,. The LODs for the organolead and total Pb methods were 0.07-0.2 and 3-19 ng Pb g-' respectively. Arnaud and Favier (93/2714) used ultrajiltration to determine the non-protein-bound Zn fraction in human milk. The ultrafiltr- ation membranes had nominal molecular mass cut-offs of <30000 Da. Contamination can be a serious problem in Zn nutrition studies. In this study the ultrafiltration apparatus was washed with EDTA (dipotassium salt) prior to use. Zinc was determined by ETAAS and the LOD was 26.4 nmol 1-'. The upper linear range was 4pmol 1-'. The amount of non- protein-bound Zn varied from 4 to 56% of the Zn in whole human milk.One conference presentation (93/C1634) and one publication (93/2896) reported the separution of Cr"' and Cr"' in mineral waters and natural waters respectively. For natural waters FI with on-line preconcentration was used prior to determination by FAAS. Chelation and extraction with 8-hydroxyquinoline and IBMK was used for Cr"' in mineral waters with determi- nation by ETAAS. by GC-MS. 2.4. Developments in Methodology for Electrothermal Atomic Absorption Spectrometry Tu (94/154; in Chinese) has reviewed the use of direct sampling techniques with ETAAS and discussed the problems encoun- tered in the application of this technique in food analysis. The simultaneous determination of trace metals by GFAAS was discussed in a conference presentation (93/C1434).Cadmium and Pb were determined simultaneously in vegetable oil. The organic sample was diluted in tetrahydrofuran and was then deposited into the graphite tube by an aerosol deposition system. This presentation also referred to the need for low LODs for the determination of Cu Pb Sb and Th in drinking water because of the tightening of federal and state regulations for these elements in potable water in the US. Lead was determined in Venezuelan drinking water environ- mental and clinical samples using Pd as an analytical isoforrner (93/3233). The authors have used the term analytical isoformer instead of the traditional term chemical modifier because the former describes the process actually being accomplished by the modifier namely analyte isoformation.It also implies the physical and chemical actions that the modifier performs on the analyte or matrix under study. The behaviour of a Pd-citric acid solution as an isoformer for Pb was compared with that of an NH,H,PO,-Mg(NO,) using an STPF. No differences were found in the effectiveness of the two mixtures. The Pb level in drinking water was found to be <0.1 pg 1-' which was the LOD for the method. Penninckx et al. (93/3955) used a combined Pd-Mg(NO,) modifier for determining Pb in foodstuffs and biological materials. They were able to perform direct determinations on diluted milk urine and blood using this modifier. Microwave digestion was used for potato samples. However the pyrolysis temperature was still depen- dent on the matrix and the authors recommended that it should be determined for each sample type. Palladium and Mg(NO,) were used with ETAAS for the determination of Pb in mussel tissue (93/C1630).An LOD of 0.6 pg 1-' was quoted. A Pd-Ca chemical modifier was used for determining130R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 P in tea leaves (93/2239). Miller-Ihli and Greene (93/4027) used Mg(N03)2 with platform atomization and peak area calibration for the measurement of Cr in food samples and other biological materials. The LOD was 5.6 pg or 0.28 pg 1-’ for a 20 p1 injection. The chemical migration of trace elements and other sub- stances from materials in contact with foodstuffs is an area of increasing interest. The use of cork stoppers for sealing liquid containers is widespread and Soares et ul.(93/3239) have determined Al Cd Cu Fe and Pb in granulated cork. Copper and Fe contribute to the instability of some alcoholic beverages and the other elements are toxic. They used diferent chemical rnodijiers depending on the unalyte. For A1 and Fe Mg(N03)2 was used; Pd-Mg(NO,) modifier was used for Pb and NH,H2P0 was used with Cd. No modifier was employed with Cu because the atomization temperature was high enough to allow pyrolysis of the organic matter without loss of analyte. The cork was digested in HN0,-HCI-HF. The mixture was evaporated to dryness and the residue taken up in HNO and diluted for determination of the metals. The method was evaluated by measuring the recoveries of standard additions of the analytes.The proposed method was considered satisfac- tory for the routine analysis of cork with LODs of 1.5 0.4 0.6 0.8 and 1.1 pg 1-’ for Al Cd Cu Fe and Pb respectively. A method for determining the amount of minerals leaching into drinking water from rubber stoppers in drinking water bottles has also been described (93/1181). Wine was analysed for Pb (94/251) after 1 + 4 dilution with a chemical modifier containing HN03-NH4H2P04- Mg( Aqueous standards were matrix matched with the wine for ethanol content. The LOD was 6.2pg 1-‘ Pb. Cadmium and Pb were determined in foods and blood using addition of 0 during the ashing stage (93/1136). This reduced background absorption and suppressed the volatilization of the target atoms during ashing by formation of the oxides. Arsenic has been determined in mussel tissue and in total diet composites (93/3934 and 94/425 respectively). A graphite cloth ribbon was fixed inside graphite pyrolysis tubes for the determi- nation of As in mussel.In earlier work the ribbon had not been fixed and this had led to poor reproducibility. Total diet samples were digested with HN03 and then ashed with MgO. Arsenic was coprecipitated with APDC with Cu and Fe as carriers. Total As was determined using plateau-type pyrolyt- ically coated graphite tubes with pyrolytic graphite platforms. The use of coated or lined graphite furnace tubes has been reported for the determination of different elements in various foods. Europium La and Yb were measured in rice wheat corn tea milk powder and vegetable samples using a graphite furnace lined with tungsten foil (93/3179).Interferences were negligible and LODs for 20 pl injections were 37.8 pg for Eu 7.85 ng for La and 4.04 ng for Yb. A Ca-based chemical modifier and a tungsten-coated graphite tube were used with Zeeman ETAAS for Si determination in mineral waters (94/465). Results were similar to those obtained by molyb- denum blue colorimetry. Graphite tubes coated with La and CaCl as chemical modifier were used by Yang (93/4015) in the determination of Mo in rice. Totally pyrolytic lanthanum coated tubes were used in preference to uncoated pyrolytic uncoated and pyrolytic lanthanum coated tubes. 2.5. Developments in Methodology for Plasma Atomic Emission Spectrometry Trace amounts of REEs and other elements in rice have been measured by ZCP-AES with sample introduction by tungsten coil ETV (93/3242).Samples were digested with HN0,-HC104 evaporated to dryness and the residue was taken up in aqueous (50%) HCl. Portions (10 pl) of the digests were dropped onto a tungsten coil inside a 1 ml glass vaporiz- ation chamber and purged with Ar. The coil was heated at low temperature to evaporate the solvent and then the tempera- ture was raised to transport the sample into the ICP. The influence of various operating parameters was investigated and under optimal conditions the LODs for eight REEs and for Co Cr Cu Fe Mg Mn and Ni were of the order of 10-9-10-11 g with RSDs of <6%. Ye and Lin (94/115) have developed a powder introduction ZCP arc system for the simultaneous determination of Ba Co Cu Fe Pb and Zn in rice flour tea leaves and wheat flour.Synthetic standards made from starch were used for calibration. To obtain good accuracy both standards and samples needed to be mixed with graphite powder (2+3). The RSDs were analyte dependent and ranged from 5 to 14%. Ultrasonic nebulization has been used with ICP-AES for water analysis (93/2208 93/C1448) and its applicability to the analysis of foods investigated (93/C1580). It is expected that ultrasonic nebulization will become increasingly used and this reviewer looks forward to more publications in the coming year. 2.6. Developments in Methodology for Inductively Coupled Plasma Mass Spectrometry Powell et al. (93/2163) have described the use of a direct injection nebulizer (DIN) for the determination of Hg in drinking water.The LOD was similar to that obtained with conventional nebulization but use of a DIN drastically reduced memory effects. Several papers report the use of ICP-MS for multi-element determinations; however the number of publications is still disappointingly small considering the potential of the tech- nique. In a comparison of NAA with ICP-MS Fardy and Warner (93/2439) analysed 50 different food types and a mixed human diet RM. They concluded that whilst NAA was time consuming and inconvenient for many applications and could not match the superior sensitivity of ICP-MS for a wider range of trace elements it did not suffer from blank problems when low LODs were required for trace concentrations in solid samples. Durrant (93/2713) used LA-ICP-MS for solid sample introduction in the analysis of CRMs including NIST No.7 Tea Leaves and IAEA CRM All Milk Powder.Two papers report the multi-element analysis of animal feed and tissues (93/3542 93/3786). Isotope dilution analysis (IDA) has been used in the determi- nation of Cu Mo and Se during the characterization of ten new CRMs (93/3544). Copper and Mo were determined after sample digestion with HNO,; the element contents were calcu- lated from the 65Cu 63Cu and 97Mo ImMo ratios respectively following spiking with 65Cu and 97Mo. After spiking with 82Se and acid digestion Se was separated from the matrices as the selenide using NaBH .The 82Se:78Se ratio was used for IDA calculations. Comparison of the results with those from other methods indicated no analytical bias.Hall and Murphy (93/3617) compared various Pb isotope ratios in tap water with those in plumbing materials to identify the source of Pb contamination. In most waters the Pb came from copper pipes or solder. Zinc isotope ratios were deter- mined in milk powder bovine serum and bovine liver RMs (93/2132). 2.7. Applications of X-ray Fluorescence Spectrometry Gunther et al. (93/1652) compared the multi-element analysis of two biological RMs by TXRF with analysis using semi- quantitutiue ZCP-MS which is recommended mainly for screen- ing purposes. The RMs were NIST SRM 1570 Spinach and NIES CRM No.6 Mussel. Only one internal standard was used for each technique. Depending upon the analyte the results for TXRF were described as ‘good to satisfactory’ whilst the results for semi-quantitative ICP-MS were reported to be ‘at least in the order of magnitude of the certified values’ to fitting ‘very well’.The authors commented that TXRF wasJOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL. 9 131 R suitable for fast multi-element analysis because it needs no special calibration specimens. Micronutrients in soybeans were determined by XRF (93/3489). Synthetic standards were prepared with cellulose as the matrix into which the analytes were incorporated prior to compaction. The results obtained for Fe Mn and Zn were compared with those obtained by AAS and the results for Cu with those from NAA. Agreement was good for Cu Mn and Zn and acceptable for Fe. The LODs were 5,2 5 and 2 pg g - ' for Cu Fe Mn and Zn respectively.2.8. Single and Multi-element Analysis of Foods Kalavska (93/3941) has discussed the optimization and unifi- cation of methods for water analysis. For the routine determi- nation of Cd Cu Mn Pb T1 and Zn ASV was as suitable as AAS methods. However in samples where the free and total metal concentrations differ significantly ASV was not the best method. Other workers have determined Pb in tap water using IDA with GC-MS (93/2424) and Cu in Spanish drinking water (93/3265). Anderson has compared the mineral (93/1129) and trace element (94/434) content of milk from four species including human milk using ICP-AES. Total concentrations and ratios between elements varied with analyte and species. For example Ca was least concentrated in human milk and most concen- trated in milk from guinea pigs.The Ca:P ratio in the latter was 1.66:l whilst in human milk it was 2.07:l. In a third publication (93/4082) Anderson has investigated the variations in major minerals found in human milk during the first five months of lactation. Samples were analysed for Ca K Mg Na and P using ICP-AES. There was considerable and signifi- cant variation amongst individuals and this should be borne in mind when balancing the dietary needs of the offspring. Dabeka and McKenzie (94/423) used ETAAS to measure total Al Cu Mn Mo and Sn in 191 Cunadian infant formulae and euaporated milks. All the samples (2 g) were digested with HN0,-citric acid for 6-18 h at 55 "C. Standards were prepared in a similar mixture without digestion. Palladium was used as a chemical modifier for A1 and Sn determinations.The mean LODs for the method were 0.021 0.043 0.006 0.063 and 0.073 pg g-' for Al Cu Mn Mo and Sn respectively. Common baby foods sold in Japan were analysed for 17 elements by ICP-AES (93/1211). The Fe content of Brazilian infant diets cooked in iron or aluminium utensils was studied (94/502). The increase in Fe from using iron utensils was 6- to 39-fold greater than in diets cooked in A1 utensils. The change if any in A1 content was not mentioned. The increase in Fe was estimated to be sufficient to satisfy the dietary Fe requirements of nursing infants. Feeding patterns and Cu and Zn nutrition were investigated by Yang et al. (93/4124) in Chinese infants. Copper and Zn in ingested milk samples was measured by FAAS.The daily intake of Zn was higher in bottle-fed infants but their Cu intake was lower than for breast-fed infants. Serum Cu and Zn levels from both groups showed no correlation with dietary intakes. Powdered cows milk imported into Bangladesh was analysed by AAS (93/4002). Concentrations were determined by com- parison with the IAEA RM A-11 Milk Powder. In almost all cases the levels of Ca K Mg and Na were much higher than the maximum limits recommended by international legislation for infant nutritional requirements and prevention of physical disorders. Copper Se and Zn concentrations have also been reported for milk from cows and goats in Burundi Africa (93/3690). Major minor and trace elements in the milk of some Egyptian animals were determined by Rashed (93/4025); the concentrations were related to soil contamination grazing plants and site.Aluminium in drinking water and beuerages was determined following on-line cation exchange with coupled FI-FAAS (93/3256). The method was applied to local water tea leaf digests and tea and coffee infusions. Quantitative data were obtained for A1 levels down to 75 ng ml-' with typical RSDs of 1-2%. 2.9. Characterization Studies A conference presentation discussed the use of ICP-AES and artzficial neural networks (ANNs) in the study of the origin and authenticity of orange juice (93/C1374). The problems to which ANNs are best applied are those which do not have precise computational answers but which require 'pattern recognition' or 'fuzzy logic'. This approach has been the subject of an extensive project by the Florida Department of Citrus for some years.An earlier pattern recognition package- ARTHUR - was used to look at the distribution of B Cu Mn and Zn in bean plants in Brazil (94/182). Manganese and Zn were determined by AAS B and Cu by colorimetry. Principal components graphs showed a separation of samples for the wet and dry growing seasons with the exception of leaf samples which have micronutrients transported to them inde- pendent of the growing season. Stable C isotope analysis has been used for the quality assessment of honey (93/2909 93/2996) and for the detection of corn-derived acetic acid in apple cider vinegar (93/2954). The latter method based on differences in the natural 13C:12C ratio was the subject of a collaborative study and the results indicated that as little as 10% added corn vinegar can be detected in cider vinegar.The technique involved the combus- tion of samples at 500°C in sealed glass tubes over CuO. The purified C 0 2 was analysed by stable isotope ratio MS (SIRMS) and results were compared with those of the Pee Dee belemnite limestone (PDB) standard for 13C I2C ratio. Pure cider vin- egars yield 613C results near -25 ppm while corn vinegar yields results near - 10 ppm. On the basis of published data for the natural variability of cider vinegar 13C 12C ratios it was recommended that samples yielding results more positive than -22.0 ppm be classified as not pure cider vinegar using this method. The method has been adopted as a first official action by AOAC International.2.10. Reference Materials and Collaborative Trials In an IUPAC collaborative survey of analytical performance (93/4125) 11 out of 24 laboratories had major problems with the quality of their method for A1 determination in food matrices. The samples were spiked milk powder and duplicate 24 h diets. The best results were obtained by participants using wet digestion in conjunction with ETAAS. In comparison in a co-operatioe experiment to determine Cd in a rice powder (93/3295) only two out of 40 reported values were rejected (at the 2.5% level of significance). A variety of methods was used and the average value for the remaining 38 results was 0.052 pg g-' (RSD= 16.6%). Acid digestion with AAS (nine laboratories) provided an average value of 0.049 pg g- (RSD = 22.2%) whilst acid digestion with ICP-AES (eight laboratories) gave an average value of 0.051 pg g-' (RSD = 15.9%).Three papers describe the production of RMs. An unpolished rice flour RM consisting of low medium and high concen- trations of Cd is being prepared by NIES Japan (93/2699). It has certified values for 13 elements and reference values for 9 others. The preparation and homogeneity testing of ten agricul- tural food RMs has been completed by Ihnat et al. (94/34). Twenty-nine elements have been tested in bovine muscle powder corn starch hard spring wheat flour soft winter wheat flour whole milk powder wheat gluten corn bran durum wheat flour whole egg powder and microcrystalline cellulose. Finally Curdova et al. (94/35) described quality control with CRMs for trace element determination in candidate RMs.132R JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY APRIL 1994 VOL.9 LOCATION OF REFERENCES The full list of references cited in this Update have been published as follows 93/998-93/C1354 J. Anal. At. Spectrom. 1993 8( 3). 137R-149R. 93/C1355-93/2093 J. Anal. Ar. Spectrom. 1993 8(4) 169R-194R. 9312094-9312710 J. Anal. At. Spectrom. 1993 8( 5 1 239R-262R. 931271 1-93/3353 J. Anal. At. Spectrom. 1993 8( 7 1 31 3R-336R. 9313354-9314131 J. Anal. At. Spectrom. 1993,8( 81 377R-404R. 94/1-94/614 J. Anal. At. Spectrom. 1994 9( 1 ) 1 R-23R. 941615-94/960 J. Anal. Ar. Sprctrom.. 1994 9(2) 73R-85R. Abbreviated forms of the literature references quoted (excluding those to Conference Proceedings) are given on the following pages for the convenience of the readers.The full references names and addresses of the authors and details of the Conference presentations can be found in the appropriate issues of JAAS cited above. Abbreviated List of References Cited in Update 9311005 J . Anal. At. Spectrom. 1992 7 617. 9311008 J . Anal. At. Spectrom. 1992 7 635. 9311016 J. Anal. At. Spectrom. 1992 7 689. 93/1022 J. Anal. At. Spectrom. 1992 7 719. 93/1025 J . Anal. At. Spectrom. 1992 7 743. 93/1026 J. Anal. At. Spectrom. 1992. 7 749. 93/1027 J. Anal. At. Spectrom. 1992,7,753.93/ 1034 Analyst 1992 117 1 157.93/ 1038 Analyst 1992 117 1373. 93/1042 Anal. Proc. 1992 29 260. 93/1047 Anal. Proc. 1992 29 279. 93/1058 Clin. Chim. Acta 1992 206 155. 9311059 Clin. Chim.Acta 1992 207 41. 93/1060 Ann. Clin. Biochem. 1992 29 377. 93/1078 At. Spectrosc. 1991 12 235. 93/1092 Agribiol. Res. 1991 44 212. 93/1096 Ann. Clin. Lab. Sci. 1991 21 328. 93/1102 Aquaculture 1991 99 105. 93/1109 Beijing Shifan Daxue Xuebao Ziran Kexueban 1991 27 217. 93/1110 Bioresour. Technol. 1992,40 73.9311116 Br. J . lnd. Med. 1991 48 735. 93/1118 Bull. Enuiron. Contam. Toxicol. 1992 48 481. 93/1119 Cunye Kexue 1991 17 118. 93/ 1 129 Comp. Biochem. Ph ysiol. A Comp. Physiol. 199 1 100A 1045. 93/1134 Eisei Kugaku 1991 37 401. 93/1136 Environ. Monit. Assess. 1991 19 27. 93/1139 Food Addit. Contam. 1991 8 477. 9311140 Food Chem. 1992 43 277. 93/1141 Forschungszent. Julich Ber. 1991 Juel 2512 186. 93/1145 Gongye Weisheng Yu Zhiyebing 1991 17 99. 93/1146 Gongye Weisheng Yu Zhiyebing 1991 17 169.93/1147 Gongye Weisheng Yu Zhiyebing 1991 17 172.93/1148 Gongye Weisheng Yu Zhiyebing 1991 17 230.9311181 Lab. Anim. Sci. 1991,41,233.93/1182 Lab. Rob. Autom. 1991,3 119. 93/1196 Methods Enzymol. 199 1 205 (Metallobiochem. Pt. 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