Determination of pyrethroid, organophosphate and organochlorine pesticides in water by headspace solid-phase microextraction

Simultaneous determination of pyrethroid, organophosphate (OP) and organochlorine (OC) pesticides in water was achieved with headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-electron-capture detection (GC-ECD). The parameters affecting HS-SPME of pesticides from water were optimized, including extraction temperature, sample and headspace volumes, and sodium chloride amounts. The effects of desorption temperature, desorption time, and position of the fibre in the GC inlet were also investigated. Extraction temperature was the most important factor affecting the recoveries of analytes, and the optimized temperature was 96°C. The addition of salt did not increase extraction efficiencies of the pesticides from the water. The optimized desorption conditions in the GC were as follows: desorption time of 10 min; desorption temperature of 260°C; and a 2 cm position of the fibre in the inlet. The method detection limits were in the low-ng/L level with a linearity range of 50–1000 ng/L for the OCs, 50–5000 ng/L for the OP, and 50–20 000 ng/L for the pyrethroids. These data demonstrated that HS-SPME is a sensitive method for the determination of pyrethroid, OC, and OP pesticides in water.