关键词: 解毒酶;甲基对硫磷;降解;动力学;降解产物

Abstract:

To identify the degradation effect on pesticide of detoxifying enzyme produced by pseudomonas alcaligenes, the degradation of methyl parathion by detoxifying enzyme in aqueous solution and on vegetable was studied and the degradation products were also analyzed using gas chromatography-mass spectrometry (GC-MS) method. The results showed that the detoxifying enzyme could effectively degrade methyl parathion, and the higher the enzyme concentration was, the better the degradation of methyl parathion was. The degradation rate of methyl parathion could reach 81.7% after methyl parathion with the initial concentration of 0.3 mg/L in aqueous solution treated with 320 mg/L enzyme for 90 min. And the degradation rate of methyl parathion could reach 58.5% after the commensurate enzyme was applied to methyl parathion with the initial concentration of 0.5 mg/kg in vegetable samples 60 min later. Furthermore, the 4-nitrophenol was identified as the degradation product of methyl parathion by GC-MS. In addition, the degradation of methyl parathion fitted the first-order kinetic model well (R2>0.84), which provided theoretical basis for its application in practice.

Key words: detoxifying enzyme, methyl parathion, degradation, kinetics, degradation product