Determination of Carbamate Insecticides in Water, Fruit, and Vegetables by Ultrasound-ssisted Dispersive Liquid-Liquid Microextraction and High Performance Liquid Chromatography

Simple dispersive liquid-liquid microextraction using a low-density solvent coupled with high-performance liquid chromatography was developed for the preconcentration and determination of methomyl, aldicarb, carbofuran, carbaryl, isoprocarb, and methiocarb. Separations were performed on a C18 column using gradient elution by methanol and 0.1% (v/v) acetic acid at 1.0mL min(-1) with ultraviolet detection at 270nm. The separation of the six carbamate insecticides was achieved within 14min. Parameters affecting the efficiency, including the types and volumes of extraction and dispersive solvents, sonication time, and electrolyte addition were optimized. The reported procedure is rapid, simple, and employs standard glassware without centrifugation. Under the optimum conditions, the calibration curves were linear from 5 to 10000 mu g L-1. The enrichment factors were up to 58 and the limits of detection were between 2 and 80 mu g L-1. Intra-day and inter-day precision values were determined to be less than 1.5% and 9.0% for retention time and peak area. The method was employed for the determination of carbamates in water, fruit, and vegetables.