Effect of pH on the Persistence Behavior of Flubendiamide in Water-A Laboratory Study

摘要

The persistence behavior of flubendiamide in water at pH 4, 7 and 9.2 was studied under laboratory-simulated condition. The initial levels of flubendiamide at pH 4, 7 and 9.2 were found to be 0.88,0.93 and 0.93 μg ml~(-1) and 1.84,1.85 and 1.91 μg ml~(-1) at the spiking levels of 1 and 2 μg ml~(-1) respectively. The dissipation of flubendiamide followed first-order kinetics irrespective of pH and application dose. The half-life values (T ) were found to vary from 107.5 to 111.5 d for pH 4, 81.36 to 83.60 d for pH 7 and 115.78 to 125.42 d for pH 9.2. The persistence of flubendiamide was in the order of pH 9.2 > pH 4 > pH 7. Desiodo flubendiamide could not be detected at any pH and thereby indicates that the flubendiamide molecule is hydrolytically stable.