Development of method for analysis of four sulfonylurea pesticides, rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl, chlorimuron-ethyl residues by high-performance liquid chromatography with diode-array detection

The method for residue analysis of four sulfonylurea pesticides, rimsulfuron, ethametsulfuron-methyl, tribenuron- methyl and chlorimuron-ethyl was examined and analyzed by HPLC with ODS column (250 mm×4.6 mm, 5 μm diameter particle size) which was maintained at 35°C. Mobile phase consisted of solvent A (20 mM KH ₂PO ₄, pH 2.5) and solvent B (acetonitrile). Isocratic elution of the column with 45% solvent A and 55% solvent B at a flow rate of 1 mL/min resulted in retention times of 5.92, 6.54, 9.28, and 14.35 min for rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl, and chlorimuron-ethyl, respectively. All injection volumes were 20 μL. The limit of quantitation was 0.02, 0.01, 0.001, and 0.004 mg/kg for rimsulfuron, ethametsulfuron-methyl, tribenuron-methyl, and chlorimuron-ethyl, respectively. Recovery rate test was performed with three farm products, rice, apple and soybean. Four sulfonylurea pesticides were spiked at concentrations of 0.05, 0.1 and 0.5 mg/kg. The recovery rates were ranged from 86.12% to 116.26% and the standard deviations of all experiments were within 10%.