Chiral Pesticides and Polychlorinated Biphenyl Congeners in Environmental Samples, Analysis of
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Garrison, A. W. 2006. Chiral Pesticides and Polychlorinated Biphenyl Congeners in Environmental Samples, Analysis of. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Over 25% of pesticides and other toxic organic pollutants are chiral, as are 19 of the 209 polychlorinated biphenyl (PCB) congeners; that is, they exist as two mirror image species called enantiomers (PCB enantiomers are called atropisomers). The enantiomers of a chiral compound have identical physical and abiotic chemical properties, but usually differ in biological properties such as microbial degradation, uptake and transport across membranes, metabolism rate, and toxicity. Chirality in the environment has become recognized as an important phenomenon since the mid-1980s, and related research has centered on the need to understand the environmental fate and effects of pesticides and PCBs. This article provides a brief background on chiral chemistry in general and the importance of chirality in the drug industry, followed by a summary of examples of the enantioselectivity of pesticide and PCB occurrences and degradation in the environment as gleaned from the scientific literature. The main emphasis is on the analysis of these compounds, with the primary focus on chiral separations. Chiral separations are generally performed by gas chromatography (GC) or high-performance liquid chromatography (HPLC) using chiral columns, or, to a lesser extent, by capillary electrophoresis (CE) using cyclodextrin (CD) or other chiral selectors in the run buffer. Summaries of these three separation methods are provided, with figures giving examples of pesticide and PCB enantiomeric separations. Finally, to show the usefulness of these separation methods, applications to several environmental chemistry problems involving chiral pesticides and PCBs are described and illustrated.