title: Simultaneous extraction and determination of various pesticides in environmental waters.
abstract: A simple and rapid method was developed for the simultaneous analysis of nine different pesticides in water samples by gas chromatography with mass spectrometry. A number of parameters that may affect the recovery of pesticides, such as the type of solid-phase extraction cartridge, eluting solvent in single or combination and their volumes, and water pH value were investigated. It showed that three solid-phase extraction cartridges (Strata-X, Oasis HLB, and ENVI-18) produced the greatest recovery while ethyl acetate/dichloromethane/acetone (45:10:45, 12 mL) followed by dichloromethane (6 mL) was efficient in eluting target pesticides from solid-phase extraction cartridges. Different water pH values (4-9) did not show a significant effect on the pesticides recovery. The optimized method was verified by performing spiking experiments with a series of concentrations (0.002-10 μg/L) in waters, with good linearity, recovery, and reproducibility for most compounds. The limit of detection and limit of quantification of this optimized method were 0.01-2.01 and 0.02-6.71 ng/L, respectively, much lower than the European Union environmental quality standard for the pesticides (0.1 μg/L) in waters. The proposed method was further validated by participation in an interlaboratory trial. It was then subsequently applied to river waters from north-east Scotland, UK, for the determination of the target pesticides.
authors.affiliation: The James Hutton Institute, Craigiebuckler, Aberdeen, UK.
authors.forename: Zulin
authors.initials: Z
authors.lastname: Zhang
authors.forename: Thibault
authors.initials: T
authors.lastname: Lefebvre
authors.forename: Christine
authors.initials: C
authors.lastname: Kerr
authors.forename: Mark
authors.initials: M
authors.lastname: Osprey
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D010575:Pesticides / Q000032:analysis*; D052616:Solid Phase Extraction; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D010575:Pesticides; D014874:Water Pollutants, Chemical
keywords: Extraction; Gas chromatography with mass spectrometry; Pesticides; Scotland; Water