Photodegradation of Napropamide in Aqueous Methanol under UV Light and Sunlight

Abstract

Photolysis of napropamide is reported under UV light (λmax ≥ 290 nm) and sunlight (λmax ≥ 250 nm). The rate of photodegradation of napropamide in aqueous methanol (10 µg mL–1) followed the first-order kinetics under UV (T½=1.09h.) and sunlight (7.72h.). On photolysis in aqueous methanol, it furnished four photoproducts (F1 , F2 , F3 and F4 ) of which F1 was a common photolysis product isolated from both sunlight and UV light. Photoproducts F2 and F3 were generated from UV irradiated solution and only F4 from sunlight irradiated solution. The plausible mechanism of photo transformation involved oxidation, dimerization, hydrolysis as well as nucleophilic displacement reactions.