[Simultaneous determination of ten sulfonylurea herbicide residues in soybeans by high performance liquid...

A reversed-phase high performance liquid chromatographic (RP-HPLC) method has been developed for the simultaneous determination of ten sulfonylurea herbicide (oxasulfuron, thifensulfuron-methyl, metsulfuron-methyl, triasulfuron, chlorsulfuron, bensulfuron-methyl, prosulfuron, pyrazosulfuron-methyl, chlorimuron-ethyl and primisufuron-methyl) residues in soybeans. Sulfonylurea herbicides were extracted with acetonitrile, followed by hexane partitioning. After the extract was cleaned up with a Florisil column, sulfonylurea herbicides were analyzed by HPLC-photo diode array detector (DAD) and quantified by external standard method. The pre-treatment method of the samples and the chromatographic conditions of the analysis were critically examined. The linear ranges of 10 sulfonylureas were 0.1 - 10.0 mg/L, and the correlation coefficients were 0.999 6 - 0.999 7. The average recoveries of ten sulfonylurea herbicides in spiked soybeans ranged from 69.8% to 100.7%, and the relative standard deviations were between 1.89% and 10.43%. The limit of detection was 20 microg/kg. The results have indicated that the method developed is easier, faster, and has better purification effect. It has also demonstrated that this multiresidue analytical method can meet the requirements for the simultaneous determination of many sulfonylurea herbicides in import and export inspection for soybeans.