Monitoring of pyrethroid metabolites in human urine using solid-phase extraction followed by gas chromatography-tandem mass spectrometry

Abstract

A method was developed for the determination of cis-, and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (Cl 2CA), cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid ( cis-Br 2CA cis-, trans), 2-(4-chlorophenyl)-3-methylbutyric acid (2-ClBA), and 3-phenoxybenzoic acid (3-PBA) in human urine. These compounds are major metabolites of commonly used synthetic pyrethroids permethrin, acrinathrin, cypermethrin, fenvelarate, deltamethrin, cyfluthrin and cyhalothrin. The method involves extraction of metabolites using solid-phase extraction, additional liquid–liquid extraction clean-up and derivatization followed by detection and quantification by sensitive gas chromatography-tandem mass spectrometry. 3-(2-methoxyphenoxy) benzoic acid was used as an internal standard. Recoveries of spiked compounds ranged between 92.3 and 113.3%, and 87.4 and 121.1% at fortification levels of 100 and 10 ng ml −1, respectively. The relative standard deviation was lower than 14.6% in all cases. The method was employed to detect and quantify pyrethroid metabolites in the urine of pest control operators and non-occupationally exposed subjects. The concentration of metabolites ranged from 269 pg ml −1 for one of the non-exposed subjects to 2.8 ng ml −1 for one of the exposed pest control operators.