PHOTOCHEMICAL DEGRADATION OF PARATHION IN AQUEOUS-SOLUTIONS

The photodegradation of O,O'-diethyl O-4-nitrophenyl phosphorothioate (common name parathion or ethyl parathion) in aqueous solutions has been studied by using u.v. radiation at different pH values. According to the experimental results it was observed that the dark reactions were negligible and the reaction rate increased as the pH increased. Finally, assuming a simple mechanism for the parathion photodegradation at initial times, the quantum yield (molecules degraded/photon absorbed) in the wavelength of parathion absorption was determined.