Determination of Pyrethroid Residues in Water by Solid Phase Extraction-Gas Chromatography-Mass Spectrometry

A solid-phase extraction-gas chromatography-mass spectrometry (SPE-GC/MS) method was developed for the determination of pyrethroid pesticide residues in water samples. The sample preparation involved enrichment using a C18 solid-phase extraction disc, followed by elution with a mixture of petroleum ether and ethyl acetate (95:5, v/v). The separation was carried out on a DB-5MS capillary column, with qualitative analysis performed using full scan mode and quantitative analysis conducted via selective ion monitoring (SIM). The method demonstrated excellent performance, successfully separating and quantifying six pyrethroid pesticides in water. The average recoveries ranged from 79.137% to 103.14%, with relative standard deviations between 5.166% and 13.12%. The limits of detection were as low as 0.0016–0.0055 μg/L when the sample was diluted 2500 times. Compared to the national standard method outlined in the 2001 edition of the "Sanitary Standard for Drinking Water," this method uses less organic solvent, offers higher sample extraction capacity, and significantly improves sensitivity and accuracy. It meets both Chinese and European Union standards for pyrethroid pesticide residue levels in water, making it a reliable and efficient analytical tool for environmental monitoring.

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