Analytical Method for Pyrethroid Metabolites in Urine of the Non-Occupationally Exposed Population by Gas Chromatography/Mass Spectrometry.

Abstract Pyrethroids are widely being used as household insecticides or mothproof repellents. An analytical method is described for determination of urinary metabolites as biomarkers for monitoring exposure to the pyrethroids. In total, 11 urinary metabolites, 3-(2-carboxyprop-1-enyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylic acid, 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid, 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid, 4-fluoro-3-phenoxybenzoic acid, 4-methoxymethyl-2,3,5,6-tetrafluorobenzly alcohol, 2-methyl-3-phenylbenzoic acid, 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol, 3-phenoxybenzoic acid, 2,3,5,6-tetrafluorobenzoic acid and 2,2,3,3-tetramethylcyclopropanecarboxylic acid, were enzymatically hydrolyzed and extracted with toluene. After transformation to their tert-butyldimethylsilyl or trimethylsilyl derivatives, they were analyzed by gas chromatography/mass spectrometry in electron impact ionization mode. The calibration curves for the metabolite were linear over the concentration range of 0-30 μg/L in urine. They could be determined accurately and precisely (detection limits: 0.01-0.12 μg/L, quantification limits: 0.04-0.41 μg/L). The urine samples collected could be stored for up to 1 month at -20°C in a freezer. The proposed method was applied to determine urine samples from several health volunteers. The method was considered to be available for monitoring pyrethroid exposure in the general population.