Residual dissipation and dietary risk assessment of mefentrifluconazole enantiomers from tea bushes to consumer products

Abstract

This study systematically investigates the enantioselective degradation of mefentrifluconazole throughout tea growth, processing, and brewing. The limits of quantification for mefentrifluconazole enantiomers were 0.0025 mg/kg in fresh tea leaves, tea, and tea infusion. The half-life of (+)-mefentrifluconazole and (−)-mefentrifluconazole ranged from 1.36–3.17 d and 1.47–3.28 d in spring and summer tea, respectively. Furthermore, the enantiomer fraction of mefentrifluconazole enantiomers in summer tea decreased from 0.51 to 0.32, indicating preferential degradation of (+)-mefentrifluconazole. The total processing factors for (+)-mefentrifluconazole and (−)-mefentrifluconazole in black tea were 3.37–4.50 and 3.18–4.60, respectively, while for green tea, they were 2.69–4.34 and 2.62–4.59, respectively. The total leaching rates of mefentrifluconazole enantiomers were 27.29 %–31.96 % in green tea and 13.71 %–14.79 % in black tea. These findings can guide the rational application of mefentrifluconazole in tea plantations. The chronic and acute risk quotients of mefentrifluconazole were significantly less than 1, suggesting acceptable dietary health risks of mefentrifluconazole in tea. However, the total dietary risk of mefentrifluconazole was 104.73 %, which poses risks to human health.