Residue behavior and risk assessment of pyraclostrobin and tebuconazole in peppers under different growing conditions

Abstract

This study evaluates the residue behavior and risks of pyraclostrobin and tebuconazole in peppers. An analytical method for the simultaneous determination of the concentration of these fungicides in peppers was developed using ultra-high performance liquid chromatography-triple quadrupole mass spectrometry. Pepper samples were extracted with acetonitrile and cleaned with primary secondary amine and graphitized carbon black. The average recoveries of pyraclostrobin and tebuconazole under three fortification levels were 86.7-101.4% and 81.7-104.4%, with relative standard deviations of 4.0-7.2% and 3.8-10.9%, respectively. The limit of quantification of both fungicides in peppers was 0.01 mg/kg. The terminal residue trial of 30% pyraclostrobin and tebuconazole suspension concentrate was investigated for samples cultivated in open fields and greenhouses. The results showed that the terminal residues of pyraclostrobin and tebuconazole in peppers were lower than the maximum residue limits established by GB 2763-2021 (0.5 mg/kg for pyraclostrobin and 2 mg/kg for tebuconazole). The results of a statistical t-test indicated that there was no significant difference between samples grown in open fields and greenhouses. According to the international estimate of short-term intake (IESTI) calculation model, provided by the Joint FAO/WHO Meeting on Pesticide Residues, the acute dietary exposure risk of both fungicides in peppers was acceptable for the general population, with an IESTI of 0-3% and 0-5% of the acute reference dose for pyraclostrobin and tebuconazole, respectively.

Keywords: Peppers; Pyraclostrobin; Residue; Risk assessment; Tebuconazole.