Influence of pH on persistence and dissipation of clofentezine, a tetrazine acaricide in water

摘要

Clofentezine is an environment friendly and integrated pest management (IPM) compatible pesticide. It is an acaricide that is used in plant protection products for the control of spider mites on a wide range of crops. It acts primarily as an ovicide, but has some activity against early motile stages of mites. In the present research, dissipation behavior of Clofentezine in acidic, neutral and alkaline water was studied. Double distilled buffered water of pH 4.0, 7.0 and 9.2 (200 ml) was spiked at two treatment doses at 1.0 and 2.00 µg/ml. Samples were withdrawn at different time intervals and extracted with a mixture of hexane/dichloromethane and analyzed by high pressure liquid chromatography (HPLC). The results of the study indicated that degradation of Clofentezine in water is highly pH dependent. Clofentezine undergoes a base catalyzed hydrolysis resulting in lowest persistence in alkaline water and highest in acidic water. The half-life values were in the range of 0.53 to 60 days.