Fast determination of β-endosulfan, α-hexachlorocyclohexane and pentachlorobenzene in the river water from northeast of China

A magnetic solid-phase extraction method for the preconcentration of three organochlorine pesticides (OCPs) from water samples has been proposed, based on magnetic phosphatidylcholine (MPC) as adsorbents. The extraction procedure was carried out in a single step by stirring the mixture of MPC and water samples. Subsequently, the MPC was collected by an external magnetic field without additional centrifugation or filtration. The analytes were desorbed from the MPC and finally analysed by gas chromatography–tandem mass spectrometry. The influence of various parameters on OCPs recoveries was studied. Results show that phosphatidylcholine amount and extraction time were critical in enhancing extraction performance, and the presence of humic acid was shown to significantly reduce the extraction efficiency. The limits of detection obtained were in the range of 0.1–0.15 ng L⁻¹. Recoveries of spiked water samples ranged from 76.2% to 101.5% with relative standard deviations varying from 3.8% to 7.7%. The proposed method was employed for analysis of pentachlorobenzene, α-hexachlorocyclohexane and β-endosulfan in the surface water from two rivers in northeast China.