Simultaneous determination of 60 pesticides in water using solid-phase microextraction and gas chromatography mass spectrometry

A new method for the simultaneous determination of 60 pesticides by solid-phase microextraction and gas chromatography-mass spectrometry is presented. The analyte mixture contains representatives from each of the organonitrogen, organochlorine and organophosphorus classes. Both polyacrylate- and polydimethylsiloxane-coated fibres are used to extract the analytes directly from the samples over the concentration range 0.1-100 mu g l(-1). The performances of the two types of coating were compared. The limits of detection with both coatings mere determined to be at the ng l(-1) to sub-ng l(-1) levels, depending on the selectivity of the coating for an analyte. The method was applied to the analysis of samples obtained from the Russian and Canadian Arctic. A contaminated groundwater sample and a contaminated soil sample, both containing metolachlor, were analysed by the proposed method and the results were found to be comparable to those obtained by a liquid-liquid extraction method. Orange juice was spiked with the 60 pesticides and their recoveries were determined.