咪唑啉酮类除草剂在水生微宇宙系统中对映选择性环境行为和毒性效应

在对映水平上开展手性农药的生态毒理和环境行为研究对指导其合理使用和安全评价具有重要意义。前期研究发现咪唑啉酮类除草剂在土壤中残留期较长、移动性强，易污染水体环境，给水生生态环境和人类健康带来重大威胁。鉴于此，本项目在前期基础上，以大量使用的三种咪唑啉酮类农药为研究对象，研究供试农药不同对映体对非靶标水生生物的毒性效应；明确其在藻-溞-鱼食物链传递过程中选择性生物富集和降解行为；利用LC-QTOF-MS及UPLC-MS-MS等分析供试药剂不同对映体在水生微宇宙中沉积物、水体、生物体不同分配相的含量、相对比值、分布、代谢和降解行为的时间变化动态过程；建立多介质Ⅳ逸度模型，结合数学模型初步揭示不同对映体选择性归宿行为规律。研究结果不仅揭示供试农药不同对映体在水生微宇宙环境中的行为归趋内在机制和毒性效应，且为该类手性农药在水生生态系统中的风险评估和污染控制提供基础数据和理论依据。

Investigation of ecotoxicity and behaviors of chiral pesticide with enantioselective methods are great significance to provide a basis for its scientific use and evaluation. Previous research on imidazolinone herbicides has shown that these pesticides may pose a high risk to human health and the aquatic environment safety because of their high persistence and strong mobility in soils. Hence, three typical extensive used imidazolinone herbicides were selected in this study and their enantiomers were employed to evaluate enantioselective toxicity to non-target aquatic organisms. A program was put forward to explore enantioselective bioaccumulation of the herbicides in the algae-daphnia-fish food chain. The bioaccumulation, distribution, biotransformation and degradation dynamics of these imidazolinone herbicides in aquatic microcosm will be evaluated by using chiral LC-QTOF-MS and UPLC-MS-MS methods. Based on an established level IV fugacity model, it will be simulated the distribution and fate of these herbicides in aquatic microcosm. The enantioselective behaviors of these herbicides in aquatic microcosm will be elucidated. The results will provide useful data for food and environmental risk assessment of chiral imidazolinone herbicides.