Gas chromatographic analysis of pesticides in water with off-line solid phase extraction

A new solid phase extraction method has been developed to measure pesticide concentrations in water. The sample is extracted using polymer–divinylstyrene extraction columns and eluted with ethyl acetate and injected in capillary gas chromatographic columns connected to various detectors. Due to the very simple extraction procedure this method has a short analysis time. The limit of quantification (LOQ) was from 0.05 to 0.1 μg/l depending on the pesticides to be analysed. The mean of the recoveries for the method was 85%. The method was compared with liquid–liquid extraction (LLE) in a study monitoring pesticide residues in natural waters of Sweden.