Low-density extraction solvent-based solvent terminated dispersive liquid-liquid microextraction combined with gas chromatography-tandem mass spectrometry for the determination of carbamate pesticides in water samples

A simple and fast method of low-density extraction solvent-based solvent terminated dispersive liquid-liquid microextraction (ST-DLLME) was developed for the highly sensitive determination of carbamate pesticides in the water samples by gas chromatography-tandem mass spectrometry (GC-MSMS) After dispersing, the obtained emulsion cleared into two phases quickly whets an aliquot of acetonitrile was Introduced as a chemical demulsifier into the aqueous bulk Therefore, the developed procedure does not need centrifugation to achieve phase separation. It was convenient for the usage of low-density extraction solvents in DLLME Under the optimized conditions, the limits of detection for all target carbamate pesticides were in range of 0 001-0 50 ng mL(-1) and the precisions were in the range of 23-6 8% (RSDs. 2 ng mL(-1), n=5) The proposed method has been successfully applied to the analysis of real water samples and good spiked recoveries over the range of 94 5-104% were obtained. (C) 2009 Elsevier B V All rights reserved