Gas chromatographic enantiomer separation of agrochemicals and polychlorinated biphenyls (PCBs) using modified cyclodextrins

Abstract

Abstract The enantiomers of the polychlorinated polycyclic xenobiotics heptachlor, cis ‐ and trans ‐chlordane, cis ‐ and trans ‐heptachlorepoxide, oxychlordane, and bromocyclen have been resolved by gas chromatography with selectively substituted cyclodextrins. The order of elution of these compounds and of α‐hexachlorocyclohexane (α‐HCH) was determined by comparison with enantiomerically enriched reference compounds obtained by preparative enantioselective gas chromatography. A separation of the eight stereoisomers of the pyrethroid insecticide allethrin into seven peaks was achieved. Both trans ‐diastereomers were separated into their enantiomers and the order of elution could be determined by comparison with commercially available ( S )‐bioallethrin and trans ‐bioallethrin. Also one cis ‐diastereomer was separated, wheras the other cis ‐isomer could not be resolved. In addition 15 out of 19 stable atropisomeric polychlorinated biphenyls with 5, 6 and 7 chlorine substituents, some chiral organophosphorus pesticides, including acephate and malaoxon and the herbicide bromoacil were separated.