ENVR 24 |
| Michael Fricke, Sean Conklin, Santha Ketavarapu Yathavakilla, Patricia Creed, Carol Schwegel, and John Creed. |
| Recently, sulfur analogs of well known arsenicals have been identified, generating a need for stable species-specific standards. This presentation will focus on the identification and characterization of a novel species, monomethylthioarsonic acid (MMTA), in carrots. A standard of MMTA was synthesized by reacting monomethylarsonic acid (MMA) with H2S. High-resolution ESI-MS/MS indicates that MMTA is produced. While MMTA appears to be stable in solution, attempts at crystallization have resulted in degradation of MMTA to MMA. Using IC-ICP-MS, MMTA was identified in carrot samples as indicated by chromatographic co-elution with the synthesized standard. However, confirmation by IC-ESI-MS/MS has been hampered by sensitivity issues. The origin of MMTA in carrots will be discussed considering the likely sulfur-oxygen exchange with MMA in sulfidic, reducing environments and/or previous use of methylarsine sulfide (CH3AsS)x as a fungicide. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. |
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Occurrence, Chemistry, Toxicity and Remediation of Arsenic
1:30 PM-4:50 PM, Sunday, 26 March 2006 Georgia World Congress Center -- B218, Oral
Division of Environmental Chemistry |