The photocatalytic degradation of a sulfonylurea herbicide, cinosulfuron, has been studied in TiO 2 aqueous suspensions. A first order kinetic law was found. The influence of the initial concentration of cinosulfuron and of the initial radiant flux on the kinetics were evaluated. The identification of the intermediate products was based on high performance liquid chromatography coupled with mass spectrometry analyses (HPLC-MS). The mineralization of cinosulfuron was traced using ion chromatography and total organic carbon (TOC) measurements. These results indicate that the photocatalytic degradation of cinosulfuron leads to CO 2, NO 3 - and SO 4 2- as final products, and in addition cyanuric acid (C 3H 3O 3N 3), confirming previous results on triazinic ring-containing compounds.
Keywords: Photocatalysis, TiO 2, Sulfonylurea, Cinosulfuron, Pesticide