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EXTRACTION AND DETERMINATION OF ARSENICALS FOUND IN FISH TISSUE
Citation:
McKiernan, J. W., C A. Brockhoff, J T. Creed, J. A. Caruso, I. Chamberlain, AND R. M. Lorenzana. EXTRACTION AND DETERMINATION OF ARSENICALS FOUND IN FISH TISSUE. Presented at 1998 Pittsburgh Conference, New Orleans, LA, March 1-5, 1998.
Description:
Arsenic in Drinking Water is regulated under the Safe Drinking Water Act. The maximum contaminant level (MCL) for arsenic is currently 50ppb. The USEPA is currently under a court order to revise the arsenic regulation by the year 2000. One aspect which requires some consideration in revising this regulation is the relative source contribution profile for arsenic from a variety of exposure sources. The two major sources of exposure from arsenic are dietary ingestion and drinking water consumption. The arsenic in drinking water is predominately inorganic arsenic while dietary foods such as seafood have a larger percentage of organically bound arsenic such as arsenobetaine. Inorganic arsenics (As III and As V) are classified as carcinogens while arsenobetaine is considerably less toxic. For this reason, analytical procedures are required which differentiate between arsenobetaine and the inorganic arsenic present in seafood. Within the FDA market basket studies, seafood is consistently found to contain elevated concentrations of "total" arsenic. Without species specific information, the actual toxicity of the total arsenic is not known. For this reason, seafood is a target food group. Therefore analytical methods are needed to determine the percentage of inorganic arsenic within seafood before an accurate assessment can be determined for this dietary compound
This presentation will utilize a mass balance approach for the evaluation of the extraction efficiencies of sonication vs. an accelerated solvent extraction (ASE) approach. A total arsenic concentration will be determined for the seafood sample as a whole and subsequent fractionation of the arsenicals between the solvent and residual solids will be evaluated using a total arsenic determination. The distribution of arsenicals in the solvent fraction will then be speciated to determine the concentration of inorganic arsenic within the seafood sample using ion chromatography inductively coupled plasma mass spectrometry (IC-ICP-MS). The results of the mass balance evaluation of the extraction procedures and the initial distribution of the arsenicals within the solvent phase will be the focus of this presentation.