Novel method for the determination of five carbamate pesticides in water samples by dispersive liquid-liquid microextraction combined with high performance liquid chromatography

A novel method for the determination of five carbamate pesticides (metolcarb, carbofuran, carbaryl, isoprocard and diethofencard) in water samples was developed by dispersive liquid-liquid microextraction (DLLME) coupled with high performance liquid chromatography-diode array detector (HPLC-DAD). Some experimental parameters that influence the extraction efficiency were studied and optimized to obtain the best extraction results. Under the optimum conditions for the method, the calibration curve was linear in the concentration range from 5 to 1000 ng mL(-1) for all the five carbamate pesticides, with the correlation coefficients (r(2)) varying from 0.9984 to 0.9994. Good enrichment factors were achieved ranging from 80 to 177-fold, depending on the compound. The limits of detection (LODs) (S/N = 3) were ranged from 0.1 to 0.5 ng mL(-1). The method has been successfully applied to the analysis of the pesticide residues in environmental water samples. (C) 2008 Zhi Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.