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ANALYSIS AND FATE OF ENANTIOMERS OF PESTICIDES AND OTHER ENVIRONMENTAL POLLUTANTS
Garrison, A W. AND J J. Ellington. ANALYSIS AND FATE OF ENANTIOMERS OF PESTICIDES AND OTHER ENVIRONMENTAL POLLUTANTS. Presented at 221st American Chemical Society National Meeting, San Diego, CA, April 1-5, 2001.
Extend existing model technologies to accommodate the full range of transport, fate and food chain contamination pathways, and their biogeographical variants, present in agricultural landscapes and watersheds. Assemble the range of datasets needed to execute risk assessments with appropriate geographic specificity in support of pesticide safety evaluations. Develop software integration technologies, user interfaces, and reporting capabilities for direct application to the EPA risk assessment paradigm in a statistical and probabilistic decision framework.
Up to 25% of pesticides and other environmental pollutants are chiral and exist as sets of mirror image isomers, or enantiomers, that usually differ in their microbiological transformation rates and toxicities. To provide for more accurate risk assessment of these chiral pollutants it is, therefore, important to determine the relative biotransformation rates of their enantiomers so as to predict their persistence and occurrences in the environment and to estimate their relative toxicities. These studies require enantiomer separation techniques based on chiral chemistry. We have adapted and applied such separation techniques using high pressure liquid chromatography, gas chromatography and capillary electrophoresis. Examples will be shown of the separation of the enantiomers of organophosphorus, organochlorine, imidazolinone, phenoxyacid and other classes of pesticides, as well as of PCBs and other environmental pollutants. In addition, applications of these separation techniques to determine the environmental occurrences of enantiomers and the enantioselectivity of microbial transformation of chiral pollutants will be discussed.
Record Details:Record Type: DOCUMENT (PRESENTATION/ABSTRACT)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL EXPOSURE RESEARCH LABORATORY
ECOSYSTEMS RESEARCH DIVISION
PROCESSES & MODELING BRANCH