The enantioselective environmental behavior and toxicological effects of pyriproxyfen in soil

We synthesized nine pyriproxyfen (PYR) metabolites and developed a chiral residual analysis method for PYR with its metabolites in five soils using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Soil degradation research showed that higher organic matter content and bigger soil particle size were conducive to the degradation of PYR and metabolites. Metabolite A 4'-OH-PYR was mainly found in five soils. PYR and metabolite A performed enantioselective degradation in soil with half-lives ranging from 2.11 d to 9.69 d and 2.80 d to 13.30 d, respectively. The activity of dehydrogenase, sucrase was inhibited and catalase activity was promoted under the disturbance of PYR. Urease was more sensitive to PYR with uncertain influences. Most soil enzymes were not restored to their initial active state after 120 d. The toxicity of metabolites to earthworms was greater than that of the parent compound PYR. This study provides the basic degradation and toxicity data of chiral pesticide PYR and its main metabolites in soil ecosystem, which is of great significance for guiding safe use and comprehensive evaluation of PYR on environmental risk.