Dissipation, Residues and Dietary Risk Assessment of Fluxapyroxad and Trifloxystrobin in Chilli Peppers

Investigating residues of fluxapyroxad and trifloxystrobin in chilli peppers is essential for food safety. In accordance with Good Agricultural Practice (GAP), supervised field trials were conducted to systematically evaluate the residue behavior and dietary exposure risks of these fungicides in chilli peppers. A validated method combining QuEChERS sample preparation with ultra-high-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) was developed to simultaneously quantify fluxapyroxad, trifloxystrobin, and their metabolites in chilli peppers. The method provided satisfactory recoveries of 92–101% with relative standard deviations (RSDs) below 6%, and the limit of quantification (LOQ) was 0.01 mg/kg for both analytes. Field-trial results showed both fungicides dissipated rapidly in peppers, following first-order kinetics with half-lives of 2.4–5.2 days for fluxapyroxad and 1.8–4.6 days for trifloxystrobin. The terminal residues of fluxapyroxad and trifloxystrobin ranged from <0.010 to 0.23 mg/kg and from 0.014 to 0.49 mg/kg, respectively. The chronic risk quotients of fluxapyroxad and trifloxystrobin were 92.57–92.61% and 13.27–13.30% of their respective acceptable daily intake (ADI), indicating that the dietary risks were acceptable. This study provides residue data and scientific evidence to support establishing and revising maximum residue limits (MRLs) for fluxapyroxad and trifloxystrobin in chilli peppers, as well as the safe use of both fungicides in China.