Citation:

CONKLIN, S., B. ADAIR, P. A. CREED, JOHN T. CREED, M. F. HUGHES, AND D. J. THOMAS. COMPARISON OF THE URINARY METABOLITES OF RATS, MICE, AND HUMANS AFTER ORAL ARSENIC EXPOSURE FOCUSING ON THIOARSENICALS. Presented at American Chemical Society Meeting, Chicago, IL, March 25 - 29, 2007.

Impact/Purpose:

To develop an arsenic speciation protocol for the analysis of dietary components and composite diets in order to provide a more accurate assessment of human exposure to arsenicals.

Description:

Urinary metabolites of arsenic are useful as biomarkers of exposure because ingested arsenic is excreted primarily in urine1. Complete urinary arsenic speciation can provide insight into possible metabolic pathways as well as potential exposure sources. The pattern of excreted metabolites depends upon which arsenicals are ingested. For example, both arsenosugars and inorganic arsenic generate dimethylarsinate (DMA) as a major urinary metabolite. For arsenosugars, this involves cleavage of As-C bonds, while for inorganic arsenic, As-C bonds are formed. In comparison, other arsenicals such as arsenobetaine and arsenocholine are excreted unchanged in urine. The recent finding of sulfur analogs of some arsenic oxides indicates that comprehensive urinary speciation has not yet been achieved. These sulfur analogs pose a unique analytical challenge because of the possible solution-phase interconversion between the oxygen and sulfur containing metabolites. The observed distribution between the two forms may be influenced by sample preparation and handling because of this equilibrium. It is with this in mind that a series of urine samples from rats, mice and humans have been analyzed specifically for the thiolated arsenicals dimethylthioarsinic acid (DMTA) and trimethylarsine sulfide (TMAS). The results are compiled here as an overview of the thio-arsenicals detected in urine (other arsenicals such as DMA and arsenate (As(V)) were detected, but are not included in this presentation).

Record Details: