ANALYSIS OF CHLORIMURON ETHYL AND TRIBENURON METHYL IN CROPS BY HPLC WITH A PHOTODIODE-ARRAY DETECTOR

An analytical method for determination of sulfonylurea herbicides, chl orimuron ethyl (CE) and tribenuron methyl (TM), in crops by HPLC was d eveloped. The sample was homogenized with acetone followed by extracti on with ethyl acetate, and the extract was evaporated. The residue was defatted by acetonitrile-n-hexane partitioning for soybean, peanut an d corn grits. The residue was cleaned up with a Florisil column and a Bond Elut(R) SAX cartrigde column. CE and TM were separated on an HPLC column (Inertsil ODS-2) using acetonitrile-water-phosphoric acid (50: 50:0.01) as the mobile phase. These compounds were detected at 240 nm. The mean recoveries of these compounds added to crops at the level of 0.1 ppm were 59 similar to 84% (CE) and 54 similar to 79%, except for peanut (TM). The detection limits of CE and TM in crops were 0.01 ppm .