Photodegradation of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea in different media and toxicity of its reaction products

The photodegradation of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl) urea in simu lated air, methanol, dioxane, hexane, and water, with a xenon lamp as light source, was studied. The rate constants and half-lives of this compound in various media under nitrogen or oxygen were determined. The photoreaction products were analyzed with HPLC-UV, CC-MS, and direct probe MS and found t o have some differences in different cases. With P-32 postlabeling DNA addu ct formation experiments, one of the main products, 2-chorobenzamide, was f ound to be able to form a DNA adduct.