Optimizing the determination of organochlorine pesticides using solid phase microextraction

In this paper we studied operating parameters to determine the optimal conditions for separation and concentration of organochlorine pesticides in aqueous samples using solid phase microextraction coupled with gas chromatography – mass spectrometry. Several parameters affecting extraction, viz. extraction mode, incubation time and temperature, stirring speed, extraction time, desorption time, bake out time and temperature, vial penetration were investigated. In our experiments we used polydimethylsiloxane 100 µm fibers at the extraction temperature of 85 °C for 10 minutes and desorption temperature of 250 °C for 3 minutes. Under these optimal conditions, the proposed solid phase microextraction method provided good linearity in the ranges of 0.5-1000 ng/mL organochlorine pesticides. The recoveries of pesticides in water samples exceeded 85%.