Program Three
Tuesday, May 20, 1997

Analytical Methods Kansa C/D



M.F. Maples, S. Kapila, and D. Armstrong, Department of Chemistry and Center for Environmental Science and Technology, 142 Schrenk Hall, University of Missouri-Rolla, Rolla, MO 65409-0010 A large number of aquatic monitoring programs are carried out to evaluate pesticide contamination of the aquatic environment. Among the tools used in monitoring campaigns are passive abiotic sampling devices which simulate the accumulation of lipophilic pesticides by aquatic organisms. In published reports on the suitability of such devices, a significant factor has been overlooked.

This factor relates to the inherent chiral selectivity of living organisms. This is an important criterion, since a number of synthetic pesticides possess one or more stereogenic centers resulting in two or more enantiomers. Often only one of the enantiomers possesses the desired biochemical properties, while others may produce deleterious effects. The magnitude of the problem is unknown, and no regulations concerning the enantiomeric purity of pesticides are in place.

The present study monitors the enantioselectivity of pesticide residues in aquatic organisms and compares it to the non-selective accumulation in the abiotic samples. The initial experiments have been carried out with chlordane because it is the most prevalent chlorinated hydrocarbon contaminant in Missouri's natural water bodies. The major constituent of technical chlordane, the octachloro dicyclopentadiene, has four enantiomeric forms and is a good model compound for investigating enantioselectivity.

Enantiospecific monitoring was achieved with a two-dimensional gas chromatograph system. In this system, conventional (achiral) separations are carried out, then the peaks of interest are heart cut to a chiral selective column. The tandem system permitted unambiguous identification of chiral selective residues at sub parts per billion levels.

Key words: aquatic organisms, pesticide residues, enantioselectivity, chiral selective residues.

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Tuesday, May 20, 1997

Metals Kansa A

Remediation of Munitions Compounds Kansa B

Analytical Methods Kansa C/D

General Topics Kansa B

Wednesday, May 21, 1997

Metals Kansa A

Zero-Valent Metals Kansa A

Remediation Kansa A

Vegetation-based Remediation Kansa B

Partnerships & Innovative Technologies Kansa C/D

Nonaqueous Phase Liquids Kansa C/D

Thursday, May 22, 1997

Biofilms & Barriers Kansa A

Bioremediation Kansa B

Partnerships & Technology Innovations Kansa C/D

Remediation Kansa C/D


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