Abstract:

【Objective】 In order to provide a theoretical and practical basis for application of radiation technology in controlling pesticide in food, the irradiation degradation effect and radiolysis products toxicity of chlorpyrifos and cypermethrin were studied. 【Method】 By irradiating chlorpyrifos and cypermethrin water-solution at the doses of 2, 4, 6, 8, and 12 kGy, the irradiation degradation effect was studied. 【Result】 The chlorpyrifos degradation rate was 98% at the dose of 4 kGy; the cypermethrin degradation rate was 84% at the dose of 12 kGy. Four main radiolysis products of chlorpyrifos and two main radiolysis products of cypermethrin were determined by using gas chromatography tandem mass spectrometry (GC/MS) analysis method. 【Conclusion】 Chlorpyrifos and cypermethrin in aqueous solution can be removed by irradiation. One of the radiolysis products of chlorpyrifos is similar to the degradation products of environmental water. The toxicity of sulfotepp is a little higher than chlorpyrifos. One of the radiolysis products of cypermethrin is its synthetical midbody. One of the radiolysis products of cypermethrin is phenoxy-benzaidehyde which is the same with the degradation products of catabolic enzymes, and its toxicity is lower than cypermethrin. The toxicity of phenoxy-benzacetonitril is lower than cypermethrin , too.

Key words: chlorpyrifos, cypermethrin, irradiation, radiolysis products, toxicity