Aerobic Aquatic Metabolism of Fenitrothion and Its Oxon Analog in Water-Sediment Systems
Rika KODAKA, Terumi SUGANO, Toshiyuki KATAGI and Yoshiyuki TAKIMOTO
J. Pestic. Sci.
27, 235-241 (2002)
The aerobic aquatic metabolism of fenitrothion and its oxon was studied in French lake and Japanese pond water-sediment to estimate their behavior in the natural aquatic environment. The effect of aeration on the metabolic profiles of fenitrothion was examined by either passing air over the surface or gently bubbling the water phase. Almost the same metabolic profiles were obtained under both conditions but the partition profiles of radioactivity between the aqueous and sediment phases differed slightly. There was no significant difference in the metabolism of fenitrothion between French and Japanese sediments. Fenitrothion mainly underwent cleavage of the P-O-aryl linkage to form the corresponding phenol and reduction of the nitro group followed by the subsequent acetylation of the amino group. The oxidative desulfuration of fenitrothion to form the oxon was a minor route. The increase in phenol and 14CO2 with less reductive transformation under the bubbling of water with air was likely to originate at least in part from less anaerobicity. The oxon derivative of fenitrothion rapidly underwent cleavage of the P-O-aryl linkage to form the phenol in the water-sediment system.
