Determination of Bensulfuron Methyl in Rice and Crayfish by Liquid Chromatography with a Column- and Eluant-Switching System and UV Detection

Abstract

Abstract Bensulfuron methyl (an active ingredient of Londax herbicide) was determined in rice and crayfish by liquid chromatography with column switching (LCCS), using a simple extraction and cleanup scheme. After bensulfuron methyl was extracted from sample with methylene chloride, the extract was concentrated, cleaned up, and reconstituted into acetonitrile–water (1+1, v/v). The extract was further cleaned up chromatographically, and then bensulfuron methyl was quantitatively determined by reversed-phase LC using a column- and eluantswitching system and UV detection at 254 nm. Bensulfuron methyl was recovered at 90 ± 8% over a range of 0.008 to 1.0 ppm from fortified samples of polished rice, rice grain, rice straw, rice hull, rice bran, aspirated grain fractions, and crayfish. Method quantitation limits were 0.008 ppm for polished rice and rice grain; 0.02 ppm for rice hull, rice bran, aspirated grain fractions, and crayfish; and0.05 ppm for rice straw.