Determination of 12 pesticide metabolites in human urine by liquid chromatography-tandem mass spectrometry

Abstract

BackgroundPesticides like organophosphorus and pyrethroids are extensively utilized, and associated potential human health risks arising from multi-route exposure, including environmental sources and dietary intake, cannot be overlooked. Conducting human exposure studies using pesticide exposure biomarkers is essential for an objective evaluation of human pesticide exposure levels. ObjectiveTo develop a rapid and precise liquid chromatography-tandem mass spectrometry method for the detection of 12 pesticide metabolites in urine, including 5 metabolites of organophosphorus pesticide, 4 metabolites of pyrethroid pesticide, 2 metabolites of herbicides, and 1 metabolite of insecticide. MethodsAfter overnight enzymatic hydrolysis, urine samples were subjected to extraction and purification using Oasis HLB 96-well solid-phase extraction. Subsequently, the samples were analyzed by liquid chromatography-tandem mass spectrometry and quantified using the isotope internal standard method. The developed method was employed to analyze 143 urine samples from a general population to assess its effectiveness and to evaluate pesticide exposure levels. ResultsAll 12 target compounds exhibited good linear ranges, with their correlation coefficients of calibration curves exceeding 0.999. The limits of detection (LOD) ranged from 0.02 to 0.19 μg·L−1, while the limits of quantitation (LOQ) ranged from 0.06 to 0.27 μg·L−1. The recoveries at three spiked levels ranged from 84% to 112%, and the inter- and intra- day precisions of targeted analystes were 0.43%-9.6% and 1.6%-9.7% respectively. Using this method, 143 urine samples from residents in Jiangsu region were analyzed, and 11 pesticides were detected except N,N-diethyl-m-toluamide (DEET). ConclusionThe established method of solid-phase extraction combined with liquid chromatography-tandem mass spectrometry has the characteristics of low detection limit, good repeatability, and high throughput, which is suitable for quantitative detection of selected 12 pesticides in large batches of human urine samples, and provides technical support for pesticide internal exposure monitoring and health risk assessment.

Keywords

• pesticide metabolite
• liquid chromatography-tandem mass spectrometry
• urine
• human biomonitoring
• internal exposure