Abstract
The use of organophosphorus compounds with high toxicity, a group of poplar agrochemicals, is now prohibited. Therefore, large amount of these compounds are still stored in agricultural farms. It is known that organophosphorus insecticides are decomposed by alkali, but its kinetic study has not been reported yet. In this paper we report the kinetics of the decomposition of five organophosphorus insecticides. The rates for three were found to be first-order with suspect to alkali and organophosphorus compound respectively, while the rates for the other two were too fast to be quantitatively determined under the applied condition. Second-order rate constants were determined at different temperatures. Reaction rates were found to depend on their structures. Decomposition products identified by GC-MS were all nontoxic substances. Thus, alkali decomposition was found to be an efficient method to decompose organophosphorus insecticides.
