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 Biology, Genetics and Breeding of Special Economic Animals and Plants, Ministry of Agriculture and Rural Affairs, Hangzhou 310008, China.
Sci Total Environ. 2023 Jun 15;877:162876. doi: 10.1016/j.scitotenv.2023.162876. Epub 2023 Mar 17.
The metabolites of pesticides usually require rational risk assessment. In the present study, the metabolites of tolfenpyrad (TFP) in tea plants were identified using UPLC-QToF/MS analysis, and the transfer of TFP and its metabolites from tea bushes to consumption was studied for a comprehensive risk assessment. Four metabolites, PT-CA, PT-OH, OH-T-CA, and CA-T-CA, were identified, and PT-CA and PT-OH were detected along with dissipation of the parent TFP under field conditions. During processing, 3.11-50.00 % of TFP was further eliminated. Both PT-CA and PT-OH presented a downward trend (7.97-57.89 %) during green tea processing but an upward trend (34.48-124.17 %) during black tea manufacturing. The leaching rate (LR) of PT-CA (63.04-101.03 %) from dry tea to infusion was much higher than that of TFP (3.06-6.14 %). As PT-OH was no longer detected in tea infusions after 1 d of TFP application, TFP and PT-CA were taken into account in the comprehensive risk assessment. The risk quotient (RQ) assessment indicated a negligible health risk, but PT-CA posed a greater potential risk than TFP to tea consumers. Therefore, this study provides guidance for rational TFP application and suggests the sum of TFP and PT-CA residues as the maximum residual limit (MRL) in tea.
农药代谢物通常需要进行合理的风险评估。在本研究中，采用 UPLC-QToF/MS 分析鉴定了哒螨灵（TFP）在茶树中的代谢物，并研究了 TFP 及其代谢物从茶树向消费转移的情况，以进行综合风险评估。鉴定出 4 种代谢物，PT-CA、PT-OH、OH-T-CA 和 CA-T-CA，在田间条件下，除了母体 TFP 的消解外，还检测到了 PT-CA 和 PT-OH。在加工过程中，TFP 进一步消除了 3.11-50.00%。PT-CA 和 PT-OH 在绿茶加工过程中均呈下降趋势（7.97-57.89%），但在红茶制造过程中呈上升趋势（34.48-124.17%）。PT-CA（63.04-101.03%）从干茶到浸出液的浸出率（LR）远高于 TFP（3.06-6.14%）。由于在 TFP 施用后 1 天茶浸出液中不再检测到 PT-OH，因此在综合风险评估中考虑了 TFP 和 PT-CA。风险商数（RQ）评估表明，健康风险可以忽略不计，但与 TFP 相比，PT-CA 对茶消费者构成了更大的潜在风险。因此，本研究为合理应用 TFP 提供了指导，并建议将 TFP 和 PT-CA 残留量之和作为茶叶中的最大残留限量（MRL）。
