Determination of the Optical Isomers of Insecticidal Pyrethroids by Gas-liquid Chromatography

Abstract

Determination of the optical isomers of insecticidal pyrethroids was carried out by gas-liquid chromatography. Chrysanthemic acid, which was obtained during hydrolysis of the corresponding pyrethroids, was esterifled with d- or l-2-octanol and the diastereoisomer ester derivatives were resolved on a column of Chromosorb W coated with 10% QF–1. All four isomers, d-trans, l-trans, d-cis and l-cis chrysanthemic acids, could be separated. These compounds were not isomerized during hydrolysis, esteriflcation or gasliquid chromatographic operations and their proportions were accurately determined from their peak area ratios.