Viable and rapid determination of organochlorine pesticides in water

Abstract

Vortex-assisted liquid-liquid microextraction (VALLME) procedure was developed for the determination of different organochlorine pesticides (OCPs) in water samples by GC-MS. After the determination of the most suitable extraction solvent and rotational speed of the vortex, parameters such as vortex extraction time, solvent volume, ionic strength of the sample were optimized by using a 23 factorial experimental design. The optimized extraction conditions for 5 mL water sample were as follows: extraction solvent, bromoform; solvent volume, 50 μL; vortex extraction time, 2 min at 3000 rpm with no ionic strength adjustment, centrifugation 5 min at 4000 rpm. Limits of detection (LODs) and quantification (LOQs) were in the range of 0.011-0.052 and 0.037- 0.173 μg/L, respectively. Mean recoveries of OCPs from fortified water samples are 96% for three different fortification levels between 0.1 and 5 μg/L and relative standard deviations of the recoveries are below 6%. The performance of the developed method was compared with traditional liquid-liquid extraction on real water samples including tap water, well water, surface (lake and stream) water, municipal wastewater, and treated municipal wastewater and comparable extraction efficiencies were obtained. The proposed VALLME procedure requires small volumes of solvent and water sample. It is viable, rapid, and easy to use for the determination of OCPs in water samples by using GC-MS. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.