STUDIES ON THE PHOTOLYTICAL BEHAVIOR OF BROMOFENOXIM IN THE ATMOSPHERE

Photodecomposition of the herbicide bromofenoxim was studied in aqueou s solution, solid state and in aerosol form. Zn all cases, bromoxynil and 2,4-dinitrophenol are the degradation products. Photodecomposition rate in solution is strongly dependent on the pH with a minimum at pH 8-10 and increasing at lower and higher pH values. Hydrolysis at pH 1 2 in darkness also yields 2,4-dinitrophenol and bromoxynil as products , while hydrolysis in acidic medium has not been observed to occur in absence of light. Photodecomposition of solid bromofenoxim deposited o n an inert surface is also studied and linked to the irradiation time. A system for generation of test aerosols is described. Dry and drople t aerosols are collected, extracted and analyzed after different times of irradiation in order to study the possible photolytical behaviour of bromofenoxim in the atmosphere.