Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China.
Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
J Sci Food Agric. 2022 Aug 15;102(10):3983-3993. doi: 10.1002/jsfa.11746. Epub 2022 Jan 25.
Tea is one of the most popular drinks in the world. The growth of tea plant is inseparable from the control of pesticides on diseases and pests. Pyriproxyfen is used as a pesticide substitute to control insect pests in tea gardens, but little is known about its residue degradation. Here, we performed an integrative study of the degradation and metabolism of pyriproxyfen from the tea garden to the cup.
The dissipation half-life of pyriproxyfen during tea growth was 2.74 days, and five metabolites PYPAC, PYPA, DPH-Pyr, 5''-OH-Pyr, and 4'-OH-Pyr were generated. The total processing factors for pyriproxyfen in green tea and black tea were 2.41-2.83 and 2.77-3.70, respectively. The residues of pyriproxyfen and its metabolites were affected by different processing steps. The total leaching rates of pyriproxyfen from green tea and black tea into their infusions were 9.8-12.3% and 5.3-13.8%, respectively. The leaching rates of the five metabolites were higher than that of pyriproxyfen and increased the intake risk.
To ensure safe consumption, the recommended maximum residue limit value of pyriproxyfen in tea can be set to 5 mg kg and the pre-harvest interval can be set to 5 days. © 2022 Society of Chemical Industry.
茶是世界上最受欢迎的饮品之一。茶树的生长离不开对病虫害的农药控制。吡丙醚被用作茶园防治虫害的农药替代品，但关于其残留降解的研究甚少。在这里，我们对吡丙醚从茶园到茶杯的降解和代谢进行了综合研究。
吡丙醚在茶叶生长过程中的消解半衰期为 2.74 天，生成了五种代谢物 PYPAC、PYPA、DPH-Pyr、5''-OH-Pyr 和 4'-OH-Pyr。绿茶和红茶中吡丙醚的总加工因子分别为 2.41-2.83 和 2.77-3.70。吡丙醚及其代谢物的残留受不同加工步骤的影响。吡丙醚从绿茶和红茶及其浸出液中的总浸出率分别为 9.8-12.3%和 5.3-13.8%。五种代谢物的浸出率高于吡丙醚，增加了摄入风险。
为确保安全消费，可将吡丙醚在茶中的最大残留限量设定为 5 mg/kg，施药至收获间隔设定为 5 天。 © 2022 英国化学学会。
