Reversed‐Phase Liquid Chromatographic Method for Analysis of Endosulfan and Its Major Metabolites

A high performance liquid chromatographic (HPLC) method suitable for the analysis of endosulfan and its metabolites in water and soil is described. Endosulfan is a contact and stomach insecticide, which is extremely toxic to fish, birds, and mammals. This method utilizes a µBondapak C18 reversed‐phase column and acetonitrile:water (70:30 v/v) or methanol:water (70:30 v/v) as a mobile phase. The maximum absorbance spectrum was obtained at 214 nm. Both mobile phases resolved the endosulfan isomers and their metabolites well (resolution R S > 1.5). Acetonitrile recovered α‐endosulfan (106 and 90%) and β‐endosulfan (103 and 80%), while methanol extracted α‐endosulfan (91 and 81%) and β‐endosulfan (72 and 56%) from water and soil slurry, respectively. Recovery of endosulfan sulfate, endosulfan diol, and endosulfan ether with acetonitrile was 99, 90, and 101% in water and 91, 81, and 90% in a soil slurry, respectively. The method has high selectivity towards the major metabolites of endosulfan. The method was optimized in extraction and chromatographic detection by HPLC.