Photodegradation of bensulfuron methyl, ( methyl-alfa-4,6-dimethoxypyrimidin-2-carbamoylsulfamoyl)-o-toluate ester) was carried out in aqueous solution under UV light. The rate of photolysis followed a first order kinetic. The main metabolites in distilled were tentatively idenified with a Diode Array Detector (DAD) and mass spectometry (MS) as (4,6-dimethoxy-2-pyrimidinyl)urea (1), methyl-alfa-4,6-dimethoxy-2-pyrimidinyl)amino-o-toluate 4) and alfa-sulfamoyl-o-toluic acid (2) that cyclises to 2-mthylsulfonylbenzoic acid imine (3). A mechanism which accounts for the formation of photoproducts is propose
