Detoxification of azinophos methyl using gamma radiation mediated advance oxidation process and investigation of degradation products by HPLC and GC-MS

Abstract

Abstract Gamma radiolytic degradation of azinophos-methyl was studied in water and methanol separately, using 60Co as a radiation source under varied experimental conditions. Solution of azinophos-methyl was prepared in pure methanol at concentration of 50 μg ml−1, irradiated at gamma dose of 1 to 7 kGy and high performance liquid chromatography (HPLC) coupled with diode array detector was used to monitor the extent of degradation along with numbers of degradation products. At dose of 7 kGy ≥ 99% of azinophos-methyl was degraded. The degradation occurred by interaction of CH3O. and H. radicals generated by the radiolysis of high purity methanol while in water by .OH radical. The degradation in water was increased by 30% than in methanol due the high oxidation potential of .OH while keeping the gamma ray dose constant at 3 kGy. The generated degradation products were identified using GC-MS and their possible transformation pathways are proposed. It is suggested that use of ionization radiations can be an effective and efficient tool for the removal of organophosphate pesticides in waste water.