Effects Of Photolysis Of Chlorothalonil By Vitamin C In Aqueous Solution

In this paper we has established a comprehensive testing methods of chlorothalonil and its possible metabolite,4-hydroxy chlorothalonil and isophthalonitrile.we also studied the influence of the degradation rate of chlorothalonil and the output of 4-hydroxy chlorothalonil by high pressure mercury lamp and sunlight light with vitamin C. the stability of vitamin C itself as well as the change of concentration of vitamin C by chlorothalonil in aqueous,which provides a reference basis for Artificial degradation of chlorothalonil.degradation rate of chlorothalonil is different when added certain concentration of vitamin C under different light sources. Sunlight degradation rate is greater than the rate of degradation under high pressure mercury lamp illumination. The half-life of chlorothalonil in the control group was 100.43min on sunlight,and the half-life at high pressure mercury lamp was I65min This is because the sun is much bigger than light intensity of high pressure mercury lamp light intensity.Under different light sources, the photosensitive promoting of vitamin C in aqueous become larger when its concentration increased, the photosensitive promoting of vitamin C for chlorothalonil under high pressure mercury lamp illumination is larger than which under high sun illumination. When added to an aqueous solution of chlorothalonil 0.5mg/L of 0.1 mg/L of vitamin C, the photosensitive promoting of vitamin C for chlorothalonil was 27.9% under the sun light, which was 65.7% under illumination of mercury. When the concentration of vitamin C was 2.5mg./L, the Sensitization rate was 282.35% Under solar illumination and Under high pressure mercury lamp illumination its sensitization rate it reached 396.39%.The concentration of vitamin C is depressed in the process of photolysis of chlorothalonil, this shows that Chlorothalonil also had a role in vitamin C While in the reaction. Chlorothalonil and vitamin C in an aqueous solution is performed simultaneously and interacting. Although vitamin C can promote the rapid degradation of chlorothalonil in aqueous solution, it did not prevent the metabolism of chlorothalonil generates 4-hydroxy chlorothalonil generation, Nor had an effect in the light degradation of 4-hydroxy chlorothaloni...