Citation:

FRICKE, M., A. ACKERMAN, P. A. CREED, C. A. SCHWEGEL, AND JOHN T. CREED. IDENTIFICATION OF DIMETHYLTHIOARSINIC ACID BY ICP-MS AND IC-ESI-MS/MS IN RICE SAMPLES. Presented at 2005 Winter Conference on Plasma Spectrochemistry, Budapest, HUNGARY, January 30 - February 03, 2005.

Impact/Purpose:

The goal is to develop an extraction protocol that mimics the human digestive tract and then to use it to assess the bioavailable fraction of arsenic from complex dietary mixtures such as a daily composite -- to move current methods toward a better human physiologically-based exposure estimate method which approximates the "true" bioavailability of arsenic within an environmental or dietary matrix.

Description:

Recently, sulfur analogs of well known arsenicals have been identified in biological and dietary matrices. In this presentation, the detection and identification of dimethylthioarsinic acid (DMTA) will be reported in rice samples after an enzymatic extraction. The enzymatic extraction is a synthetic two stage extraction; the first simulates the stomach and the second stage simulates the environment of the small intestine. The DMTA confirmation includes the co-elution of a DMTA standard and the DMTA in the rice extracts using two chromatographic separations and ICP-MS detection. In addition, the structure of this arsenical was confirmed using IC-ESI-MS/MS with a molecular ion of m/z 153 and fragment ions of m/z 138, 123, 105 (negative mode). Preliminary information will be provided with respect to the production of a standard and the stability of that standard in chromatographic mobile phase eluents. This identification of DMTA in rice and the report by other researchers of DMTA in sheep wool and urine may indicate a more widespread occurrence in nature.

Record Details: