Residue distribution and risk assessment of bifenazate and its metabolite in garlic plant

Abstract

The dissipation, conversion and risk assessment of bifenazate and bifenazate-diazene in garlic plant were studied by a modified QuEChERS method coupled with UHPLC-MS/MS for the first time. Bifenazate dissipated rapidly in garlic chive and serpent garlic with the half-lives of 3.0-3.9 days and 6.1-6.9 days, respectively. Bifenazate residue on garlic (<0.01 mg/kg) was significantly lower than the other two matrices in the whole growing period, which meant residues in the above-ground part were not transferred to the garlic. Furthermore, garlic chive had higher residues than serpent garlic due to the differences in morphological characteristics. Bifenazate-diazene was easier to convert to bifenazate, with the conversion rates of 93%, 16% and 32% in garlic, serpent garlic and garlic chive extracts, respectively. Additionally, the dietary intake risk for bifenazate was acceptable with RQ_chronic < 100% according to the international and national assessments.

Keywords: Bifenazate; Bifenazate (PubChem CID:176879); Conversion; Metabolite; Residue distribution; Risk assessment; acetonitrile (PubChem CID: 6342); ammonium acetate (PubChem CID: 517165); ascorbic acid (PubChem CID: 54670067); bifenazate-diazene (PubChem CID: 69250380); formic acid (PubChem CID: 284); methanol (PubChem CID: 887).