Florpyrauxifen-Benzyl in Paddy Field Environment : Its Residue Analysis, Dissipation Dynamics, Storage Stability, Dietary Risk Assessment and Decontamination

Florpyrauxifen-benzyl is a new herbicide developed to control troublesome weeds in rice production. An efficient QuEChERS method coupled with UPLC-QTOF-MS/MS technology was developed and validated for determination of florpyrauxifen-benzyl residues in paddy field environment. The field trials were conducted in 2021 to monitor florpyrauxifen-benzyl dissipation in Jiangxi, China. The dissipation dynamics of florpyrauxifen-benzyl followed first-order kinetics. The half-lives of florpyrauxifen-benzyl in paddy water, paddy soil and rice straw were less than 3 days. Degradation rates of florpyrauxifen-benzyl in paddy field samples were 23.84 ~ 33.75% after 7 weeks when stored at -20 °C. The chronic dietary risk assessment results showed that residues in brown rice do not seem to pose any dietary risk to the Chinese consumers. The residues of florpyrauxifen-benzyl were removed from brown rice using simple decontamination methods. These results will contribute to guide the practical application of florpyrauxifen-benzyl and minimize the environmental risks associated with its global use