Dissipation, Residue, and Dietary Risk Assessment of Bifenthrin, Bifenazate, and Its Metabolite Bifenazate-Diazene in Apples Based on Deterministic and Probabilistic Methods.

A rapid, sensitive, and effective multiresidue analytical method was established to investigate the degradation rate and final residues of bifenthrin, bifenazate, and its metabolite bifenazate-diazene in apples, and the dietary risk of consumers was evaluated. The residues of bifenthrin, bifenazate, and bifenazate-diazene in apple samples from 12 different apple-producing areas of China were determined by high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS). The average recoveries of the three compounds in apples were 88.4-104.6%, and the relative standard deviations (RSDs) were 1.3-10.5%. The limit of quantification (LOQ) for each compound was 0.01 mg/kg. Although the degradation half-lives of bifenthrin, bifenazate, and bifenazate-diazene were 17.8-28.9, 4.3-7.8, and 5.0-5.8 days, under good agricultural practice (GAP) conditions, the final residues of bifenthrin, bifenazate, and the sum of bifenazate and its metabolite bifenazate-diazene in apples were <0.01-0.049, < 0.01-0.027, and <0.02-0.056 mg/kg, respectively, which were lower than the maximum residue limit (MRL) in China. By comparing the deterministic model with the probabilistic model, the results of the probabilistic model at the P95 level (12.91-48.9% for bifenthrin, 17.48-52.01% for bifenazate including its metabolite) were selected as reasonable assessment criteria for chronic dietary risk, and the acute risk was at the P99.9 level (3.00-15.59% for bifenthrin). Although the exposure risk calculated by both the deterministic model and the probabilistic model was less than 100%, the risk to children is significantly higher than that of the general population. This suggests that in future research and policy making, we should pay more attention to the risk of vulnerable groups such as children.