The photodegradation of the herbicide pendimethalin in methanol-water system with riboflavin as sensitizer was studied under sunlight. The sensitized degradation was much higher (57.62%) than that without riboflavin (10.87%). The GC-MS analysis established the formation of seven photoproducts of which three, namely 3,5-dinitro-4-(1-ethylpropylamino)-benzene-1,2-dimethanol, 5-methyl-6-hydroxymethyl-7-nitro-benzimidazole and 5-methyl-7-nitroso-1-(1-ethylpropyl)-benzimidazole-6-aldehyde were new.
Pendimethalin, riboflavin, photodegradation, sunlight
