Photodegradation of chlorothalonil on cabbage leaves

In this study, the photolysis of chlorothalonil on cabbage was investigated. The water extracts of the green and purple cabbage were used to investigate the effect of two cabbage leaves on the photolysis of chlorothalonil and the photodegradation of chlorothalonil under artificial light. The results showed that the photodegradation half-lifes of chlorothalonil in aqueous solution were 80.58 min and 70.71 min in the presence of the water extracts of green and purple cabbage leaves under the irradiation of xenon lamp. The degradation rates were increased by 7.17 times and 8.71 times respectively compared to those in the absence of the water extracts of two cabbage leaves. Chlorothalonil underwent photo-oxidation, photoredox, and photocatalytic hydrolysis reactions in the presence of two cabbage leaves water extract. The degradation of chlorothalonil on the leaves of two kinds of cabbages was in accordance with the first-order kinetic with the half-lives of 12.68 h and 11.25 h under UV lamp, respectively. The photolysis rate of chlorothalonil was higher on the traumatic cabbage leaves than that on the untraumatic cabbage leaves. The results could provide reference for the scientific use of chlorothalonil and its food safety risk assessment.