[Photolysis kinetics of propisochlor in water]

Propisochlor in water was irradiated at room temperature by a 400 W high pressure mercury lamp and sunlight, respectively. Influence of light and initiative concentration of propisochlor on the photolysis were studied. The results showed that under the irradiation of sunlight the photolysis fitted first order kinetics with only 5.5% degradation after one hour's irradiation in the quartz tube, that was a slow rate; while under the irradiation of high pressure mercury lamp the photolysis can be described by a double-chamber model, in which the degradation rate can reach 80.9% after 1 h. The higher the initiative concentration of propisochlor was, the slower the photolysis rate became, and the photolysis of propisochlor was influenced by the increasing photo-products. The six main photodegradation products were identified using GC-MS method. The aromatic ring was proved to be intact during the process. And the photolysis mechanism was then assumed on the basis of the photo-products detected.