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SPECIATION OF ARSENIC IN BIOLOGICAL MATRICES BY AUTOMATED HG-AAS WITH MULTIPLE MICROFLAME QUARTZ TUBE ATOMIZER (MULTIATOMIZER)
Citation:
HERNANDEZ-ZAVALA, A., T. MATOUSEK, Z. DROBNA, O. VALENZUELA, L. M. DEL RAZO, B. ADAIR, J. DEDINA, D. J. THOMAS, AND M. STYBLO. SPECIATION OF ARSENIC IN BIOLOGICAL MATRICES BY AUTOMATED HG-AAS WITH MULTIPLE MICROFLAME QUARTZ TUBE ATOMIZER (MULTIATOMIZER). Presented at Society of Toxicology Annual Meeting, Charlotte, NC, March 25 - 29, 2007.
Description:
Analyses of arsenic (As) species in body fluids and tissues of individuals chronically exposed to inorganic arsenic (iAs) provide essential information about the exposure level and pattern of iAs metabolism. This information facilitates the risk assessment of disorders associated with iAs exposures. We have previously described an oxidation state-specific analysis of As species in biological matrices by hydride-generation atomic absorption spectrometry (HG-AAS), using a cryo-trap for preconcentration and separation of arsines. In order to improve performance and detection limits of the method, we have recently automated the cryotrapping and HG step and replaced a conventional flame-in-tube atomizer with a newly developed multiatomizer. Arsines from As(III)-species are generated in a mixture of 0.75M Tris-HCl (pH 6) and 1% sodium borohydride. For generation of arsines from As(V)-species, samples are pretreated with 2% L-cysteine. The analytical performance of this system was characterized using cultured cells and tissues of mice exposed to iAs. Detection limits have improved significantly reaching 12 pg for iAs, 17 pg for MAs, and 13 pg for DMAs in cell lysates. Recoveries were between 92-98%. The redesigned system was used for As speciation in exfoliated bladder cells isolated from 21 individuals exposed to iAs in drinking water. All samples contained iAs, MAs and DMAs; however, the amounts and proportions of these arsenicals varied among donors and did not correlate with As levels in urine. The sum of As species in cells ranged from 4 to 18 ng. Analysis of As species in small samples from human tissues targeted by iAs exposure may provide an effective tool for risk analysis of diseases associated with this exposure. (This abstract does not reflect US EPA policy.)