Evaluation of dispersive liquid-liquid microextraction coupled with gas chromatography-microelectron capture detection (GC-µECD) for the determination of organochlorine pesticides in water samples.

The extraction efficiency of a dispersive liquid-liquid microextraction (DLLME) method coupled with gas chromatography-microelectron capture detection (GC-µECD) for the simultaneous determination of 20 organochlorine pesticides (OCPs) in water samples was evaluated. The optimum conditions of DLLME for OCP measurement in water sample were determined with 10 µL of carbon tetrachloride (CCl(4)) and 1.5 mL of acetone as the extraction and dispersive solvents, respectively, all measurements were conducted under room temperature without the addition of salt. OCPs were extracted with good recoveries (60.35 - 107.89%) by the proposed method, except for heptachlor and aldrin due to the specific physico-chemical properties of these chemicals. Quantitative analysis showed that the relative standard deviations (RSDs) were below 9% and rather wider linear ranges (LRs) of 0.1 - 50 µg/L were obtained. The limits of detection (LODs) were in the range of 0.21 - 11.65 ng/L and no significant matrix effects were observed. Obtained results demonstrated that DLLME coupled with GC-µECD was rapid, convenient and efficient for OCP analysis in water samples.