Development and Validation of a HPLC-UV Method for Simultaneous Determination of Five Sulfonylurea Herbicide Residues in Groundnut Oil Followed by Matrix Solid-Phase Dispersion

A simple, sensitive, and inexpensive method was developed using matrix solid-phase dispersion (MSPD), together with high performance liquid chromatographic method for determination of sulfonylurea herbicide residues (nicosulfuron, pyrazosulfuron ethyl, metsulfuron methyl, chlorsulfuron and azimsulfuron) in groundnut oil. The evaluated parameters included the type and amount of sorbent (silica gel, C 18 and florisil) and the nature of eluent (ethyl acetate, dichloromethane, and acetonitrile). The best results were obtained using 1.0 g of groundnut oil sample, 1.0 g of C 18 as sorbent, and 20 mL of ethyl acetate-dichloromethane (1 : 1, (v/v)). The method was validated using groundnut oil samples spiked with sulfonylurea herbicides at different concentration levels (0.05 and 0.5 g/mL). Average recoveries (using each concentration six replicates) ranged 90–97%, with relative standard deviations less than 3%, the concentration of calibration solutions was in the range 0.01–2.0 g/mL and limits of detection (LOD) as well as limits of quantification (LOQ) were 0.01 g/mL and 0.05 g/mL, respectively.