Determination of Sulfonylurea Herbicides in Food Crops by Matrix Solid-Phase Dispersion Extraction Coupled with High-Performance Liquid Chromatography

A simple and sensitive method was developed for the determination of four sulfonylurea herbicides (metsulfuron-methyl, chlorsulfuron, chlorotoluron, and bensulfuron-methyl) using matrix solid-phase dispersion (MSPD) extraction followed by high-performance liquid chromatography. The experimental conditions for the MSPD extraction, such as type and amount of dispersant, the ratio of dispersant to sample, type and volume of washing and elution solvent were evaluated and optimized. Under the optimal conditions, the calibration curves for the sulfonylurea herbicides had good linear relationships (r > 0.997) in the concentration range of 0.2-10 mu g g(-1), and the limits of detection were in the range of 0.02-0.07 mu g g(-1). The recoveries of the sulfonylurea herbicides at two fortification levels were between 62.0 and 102.6 % with the relative standard deviations less than 6.92 %. The methodology was successfully applied to the analysis of four sulfonylurea herbicides in food crops.