Estimation of residues of carbofuran and its metabolites in sugarcane and soil by derivatization with 1-fluoro-2,4-dinitrobenzene and gas chromatography with nitrogen-phosphorus detection

Residues of carbofuran and its metabolites were studied in sugarcane plants and soil after application at 1 and 2 kg/ha, The residues of carbofuran an d its metabolites were extracted by refluxing with 0.25N HCl, partitioned i nto dichloromethane, and cleaned up on acidic alumina. The respective 7-phe nols of carbofuran, 3-keto-carbofuran, and 3-hydroxycarbofuran were destroy ed by treatment with eerie ammonium sulfate, and the residues were derivati zed with 1-fluoro-2,4-dinitrobenzene. The derivatives were estimated by gas chromatography with nitrogen-phosphorus detection. The concentration of 3- hydroxycarbofuran in sugarcane plants remained higher and persisted longer than that of the parent compound. Carbofuran-derived residues were not dete cted in cane juice. Soil samples were found to contain only carbofuran, whi ch declined at a very fast rate that followed a first-order kinetics rate o f reaction.