Chiral analysis of organochlorine pesticides in Alabama soils

The enantiomeric composition of organochlorine (OC) pesticide residues was investigated in 32 agricultural and 3 cemetery soils from Alabama. The enan tiomeric signatures were similar to those from other soils in US and Canada . The enantiomer fractions (EFs) of o,p'-DDT showed great variability, rang ing from 0.41 to 0.57 while the EFs of chlordanes and chlordane metabolites were less variable and differed in general significantly from racemic. Ena ntioselective depletion of (+)trans-chlordane, (-)cis-chlordane, the first eluting enantiomer of MC5, and enrichment of (+)heptachlor-exo-epoxide and (+)oxychlordane was found in a large majority of the samples with detectabl e residues. The enantiomeric composition of alpha -hexachlorocyclohexane wa s racemic or close to racemic. (C) 2001 Elsevier Science Ltd. All rights re served.