Henan Key Laboratory of Tea Plant Comprehensive Utilization in South Henan, College of Tea Science, Xinyang Agriculture and Forestry University, Xinyang, China.
Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, Hangzhou, China.
J Sci Food Agric. 2021 Aug 15;101(10):4134-4141. doi: 10.1002/jsfa.11049. Epub 2021 Jan 13.
Chlorpyrifos (CPF) is a broad-spectrum organophosphorus pesticide widely used to control tea geometrid (Ectropis oblique) and tea green leafhoppers (Empoasca pirisuga Matsumura) in tea trees. The major metabolite of CPF in water, plants, and animals is 3,5,6-trichloro-2-pyridinol, which is more toxic than CPF. However, the dissipation pattern of CPF in tea is unknown.
An optimized QuEChERS sample preparation method combined with ultra-performance liquid chromatography-tandem mass spectrometry was applied to determine the residues of chlorpyrifos and its metabolite in tea during tea planting and green tea processing. During tea planting, the sum of chlorpyrifos and its metabolite dissipated rapidly with a half-life of 1.93 days for tea shoots. The residues of chlorpyrifos and its metabolite in made green tea were 96.89 and 35.88 μg kg on the seventh day. The values for processing factors of chlorpyrifos and its metabolite were all less than 1, showing that each green tea manufacturing step was responsible for the reduction. The transfer rates of chlorpyrifos and its metabolite from made green tea to its infusion were 0.68-4.62% and 62.93-71.79%, respectively.
The risk of chlorpyrifos was negligible to human health based on the hazard quotient, which was 7.4%. This study provides information relevant to the reasonable application of chlorpyrifos in tea planting and is potentially helpful for tea exporting and importing countries to establish harmonized maximum residue limits. © 2020 Society of Chemical Industry.
毒死蜱（CPF）是一种广谱有机磷农药，广泛用于防治茶树茶尺蠖和茶绿叶蝉。CPF 在水、植物和动物中的主要代谢物是 3,5,6-三氯-2-吡啶醇，其毒性比 CPF 更强。然而，CPF 在茶中的消解模式尚不清楚。
采用优化的 QuEChERS 样品前处理方法结合超高效液相色谱-串联质谱法，测定了茶园种植和绿茶加工过程中 CPF 及其代谢物在茶叶中的残留。在茶园种植过程中，CPF 及其代谢物的残留量迅速下降，茶芽的半衰期为 1.93 天。加工第七天，制成绿茶中 CPF 和其代谢物的残留量分别为 96.89 和 35.88μg/kg。CPF 和其代谢物的加工因子均小于 1，表明每个绿茶加工步骤都起到了降低残留的作用。CPF 和其代谢物从制成绿茶到其浸出液的转移率分别为 0.68-4.62%和 62.93-71.79%。
根据危害商数，CPF 对人体健康的风险可以忽略不计，为 7.4%。本研究为合理应用 CPF 于茶园种植提供了相关信息，可能有助于茶叶出口国和进口国建立协调一致的最大残留限量。© 2020 英国化学学会。
