Residue monitoring and dietary risk evaluation of fungicide propiconazole in leafy vegetables under greenhouse conditions

Abstract

Residue monitoring of propiconazole (PCZ) in three leafy vegetables (cabbage, shallot, and spinach) was conducted under multitrial greenhouse conditions. The key objective of this study was to understand the fate of the applied fungicide in these vegetables. In addition, the associated health risk of PCZ in leafy vegetables was assessed through dietary risk assessment. Commercial grade propiconazole (22% suspension concentrate) was administered thrice based on the OECD fungicide application interval guideline. The plant samples were extracted using a slightly modified QuEChERS technique and analyzed using gas chromatography-tandem mass spectrometry. The average propiconazole recovery was between 84.5 % and 117.6 %, with a coefficient of variance of <5%. The dissipation of PCZ residue in cabbage, shallot, and spinach after 14 days was 96%, 90%, and 99% respectively, with half-lives of <5 days. Meanwhile, dietary risk assessments using the risk quotient (RQ) of PCZ residues in the studied vegetables were significantly <100 (RQ < 100). Thus, the population groups considered in this study were not at a substantial risk from consuming leafy vegetables sprayed with propiconazole in accordance with critical good agricultural practices.