High performance liquid chromatographic method for residue determination of sulfosulfuron

A method was developed for sulfosulfuron [(1-(2-ethylsulfonylimidazo [1,2-a] pyridin-3-ylsulfonyl)-3-(4,6-dimethoxy pyrimidin-2yl)] and its three major metabolites by HPLC utilizing photodiode array detector. The method makes use of Lichrosphere RP-8 column and acetonitrile:water:orthophosphoric acid (80:20:0.1 v/v/v) as mobile phase at a flow rate of 1 ml min(-1). Using these condition sulfosulfuron, and compounds II, III and IV were resolved with distinct Rt of 2.088, 2.216, 2.302 and 2.476 minutes, respectively. Sulfosulfuron residues were analysed in soil, wheat grain and straw samples by extracting with a mixture of acetonitrile and 2 M ammonium carbonate (100 ml, 9:1, v/v) using horizontal shaker for soil and Soxhlet apparatus for wheat grain and straw samples. The extracts were cleaned up by partitioning with dichloromethane in case of soil and hexane followed by dichloromethane for plant samples. The percent recovery ranged between 71 to 75.2 for soil and 70.8 to 74.7 for plant samples. The limit of determination of sulfosulfuron was 0.25 microg g(-1).