Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China.
Tea Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou 310008, China; Key Laboratory of Tea Quality and Safety Control, Ministry of Agriculture and Rural Affairs, Hangzhou 310008, China.
Food Res Int. 2024 Sep;192:114679. doi: 10.1016/j.foodres.2024.114679. Epub 2024 Jul 5.
Studies on nitenpyram determination and behavior within tea remain limited despite its widespread use as a neonicotinoid. An organic-saving analytical approach tailored for the detection of nitenpyram in tea was established. Nitenpyram was extracted by boiling water and cleaned up by Cleanert PCX solid-phase. The average recoveries were 75.1-94.5 %, with relative standard deviations (RSDs) of 0.7-8.6 % for saving 34.5-88.6 % organic solvent. The limits of quantification (LOQs) were 0.002 mg·kg in fresh tea shoots, 0.005 mg·kg in made tea, and 0.001 mg·L in tea brew, satisfying the current minimum Maximum Residue Limit (MRL). Nitenpyram dissipated rapidly with half-lives of 1.2-1.4 days at the recommended dosage (27 g a.i. ha) in two locations. Remarkably, 20-110 % of nitenpyram was leached out from made tea in different brewing modes. This work provides insights into nitenpyram's rational application in tea cultivation and offers considerations to institutions tasked with unestablished MRLs in tea.
尽管尼丁吡蚜酮作为新烟碱类杀虫剂被广泛使用，但关于其在茶叶中的测定和行为的研究仍然有限。本研究建立了一种针对茶叶中尼丁吡蚜酮检测的有机试剂节省型分析方法。茶叶中的尼丁吡蚜酮采用沸水提取，Cleanert PCX 固相萃取净化，平均回收率为 75.1%-94.5%，相对标准偏差（RSD）为 0.7%-8.6%，节省 34.5%-88.6%的有机溶剂。在新鲜茶芽、成品茶和茶泡液中的定量限（LOQ）分别为 0.002mg·kg、0.005mg·kg 和 0.001mg·L，满足当前最低最大残留限量（MRL）的要求。在推荐剂量（27 g a.i. ha）下，该药剂在两个地点的半衰期为 1.2-1.4 天，迅速消解。值得注意的是，不同冲泡模式下，成品茶中尼丁吡蚜酮的浸出率为 20%-110%。本研究为茶叶中尼丁吡蚜酮的合理使用提供了参考，并为尚未制定 MRL 的机构提供了考虑因素。
