Determination,residue analysis,dietary risk assessment,and processing of flupyradifurone and its metabolites in pepper under field conditions using LC–MS/MS

An effective method based on LC–MS/MS was established to determine the concentrations of flupyradifurone, difluoroacetic acid, and 6-chloronicotinic acid in pepper. On the basis of this method, the dissipation, processing factor, and dietary risk of flupyradifurone in pepper were investigated. The results show that the half-life of flupyradifurone in peppers was 2.6–3.8 days. The terminal residual concentration of flupyradifurone in the supervised trials was not higher than the maximum residue limit (MRL) for pepper in the Codex Alimentarius Commission (CAC) (0.9 mg kg⁻¹) with the highest residual values of 0.53 mg kg⁻¹. The national estimated daily intake of flupyradifurone was 0.00094 mg kg⁻¹, based on the dietary structure of Chinese consumers and the terminal residues under field conditions. The risk quotient for flupyradifurone was 0.012, which was significantly < 1. The processing factor of flupyradifurone in dried pepper was 10.9–14.2, which indicated that drying increased the residual amounts of flupyradifurone in dried pepper, but the residual concentration was still lower than its MRL of 9 mg kg⁻¹ established by CAC.