Photodegradation of the benzothiostrobin in solution and on soil and glass surface

The photolytic characteristics of benzothiostrobin were investigated in solution and on soil and glass surface. The main influence factors such as initial concentration, organic solvent and the aqueous environmental substances, including NO₂^-, NO₃^-, Fe²⁺, Fe³⁺, H₂O₂ and turbidity were investigated. Three photodegradation products of benzothiostrobin were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The photodegradation rates of benzothiostrobin increased with decreasing initial concentration of benzothiostrobin. The degradation rates of benzothiostrobin in different organic solvent showed the following order: n-hexane > methanol > acetonitrile > acetone. The photodegradation of benzothiostrobin was promoted by Fe³⁺, NO₂^- and H₂O₂, and were inhibited by Fe²⁺ and turbidity. The presence of NO₃^- had no effect on photodegradation. Benzothiostrobin was photodegraded at a slower rate on soil surface and glass surface compared to its photolysis in aqueous solution. The presumed photodegradation pathway was proposed to be the cleavage of the thioether bond in benzothiostrobin.