Simultaneous determination of nine pyrethroids in indoor insecticide products by capillary gas chromatography.

A gas chromatographic method was developed for simultaneous determination of nine pyrethroids (permethrin, transallethrin, beta-cypermethrin, prallethrin, tetramethrin, transfluthrin, cyphenothrin, phenothrin, imiprothrin) in indoor insecticide products using dibutyl phthalate and iso-octyl phthalate as two internal standards. Parameters affecting the extraction and separation efficiency were investigated. Good linear fit curves were obtained in a range of 0.4-900mg/l with correlation coefficients >0.999. The proposed method was successfully applied for the determination of pyrethroids in mosquito coils and two aerosol products. The recovery of transallethrin in mosquito coils at three spiked levels was 96.8% with relative standard deviation less than 2.7%. The recoveries of transallethrin, tetramethrin, permethrin and cyphenothrin in aerosol products were 97.2%, 96.4%, 94.3%, 94.6% with RSD less than 2.3%, 2.8%, 3.1%, 2.9%, respectively.