Lovely Yeasmin, Shawn A. MacDougall, B. Wagner
May 20, 2009
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0
Influential Citations
17
Citations
Journal
Journal of Photochemistry and Photobiology A-chemistry
Abstract
Abstract Azinphos-methyl (AZM) is a widely used organophosphate insecticide and acaricide, with demonstrated negative impacts on the environment. Upon absorption of UV-A radiation, this molecule undergoes photolysis to the highly fluorescent compound N-methylanthranilic acid, which undergoes subsequent photolysis to photochemically stable products. The identity of N-methylanthranilic acid as the highly fluorescent photochemical intermediate was determined by fluorescence spectroscopy, and the identity of benzazimide as the major final photoproduct was determined by 1 H NMR spectroscopy and high performance liquid chromatography. A detailed UV-A photolysis mechanism is proposed, involving two pathways, the major one leading to benzazimide as the stable photoproduct, and the other to N-methylanthranilic acid as an intermediate and aniline as a final stable photoproduct. This photolysis has implications for fluorescence-based trace analysis of this pesticide, as controlled UV exposure results in significant fluorescence enhancement of AZM in solution via formation of the highly fluorescent intermediate N-methylanthranilic acid. It also has importance in the environmental fate of this pesticide, as the UV-A in sunlight is found to decompose an aqueous solution of this pesticide over the course of a single day.