Abstract
An analytical method was developed for determining the four optical isomers of a new synthetic pyrethroidal insecticide, α-cyano-3-phenoxy-benzyl 2-(4-chlorophenyl)isovalerate (Fenvalerate, S-5602). The cyano group in S-5602 molecule was converted into l-menthyloxy-carbonyl group by heating S-5602 with l-menthol and hydrochloric acid. The obtained diastereoisomer derivative (l-menthyl ester deriv.) was chromatographed on a μPorasil column (4mm i.d.×0.3m) using a solvent system of hexane-ethyl acetate (500+7, v/v) as a mobile phase, and the four isomers of S-5602 were separated from one another within 20min. The compositions of S-5602 isomers were determined from their peak areas.