磁性混合模式限进萃取介质的创制及其在血浆中苯氧羧酸类除草剂自由溶解态快速分析中的应用

Phenoxy acid pesticides are one kind of the most widely used herbicides, and it has been shown that this kind of herbicides has a certain toxicity on humans and animals. For correct assessment of bioavailability and toxicity of phenoxy acid herbicides in vivo, analysis of their freely dissolved concentrations and pesticide-serum protein interactions are of great significance. Negligible depletion solid-phase microextraction (nd-SPME) is the most commonly used method for analysis of freely dissolved concentrations in biological and environmental samples. However, nd-SPME also has some disadvantages, such as long extraction equilibrium time, matrix interferences from proteins and other macromolecules, low extraction efficiencies for charged analytes, and expensive and easily damaged extraction fiber. To solve those problems, the present study introduces magnetic solid phase extraction (MSPE) technology to study freely dissolved pesticide and pesticide-serum protein interactions. We plan to prepare and characterize a novel magnetic mixed-mode restricted-access extraction medium, and the adsorption performance for phenoxy acid herbicides will be evaluated to study the adsorption behavior of this kind of pesticides on the prepared separation medium. Then pesticide-serum protein interactions will be studied. At last, the magnetic mixed-mode restricted-access extraction medium will be used as an adsorbent of MSPE to achieve quick and easy analysis of freely dissolved concentrations of phenoxy acid herbicides. The present study not only presents new ideas for the study of freely dissolved pesticide and pesticide-serum protein interactions, but also can provide technical support for assessment of the bioavailability and toxicity of pesticide in vivo.

苯氧羧酸类农药是应用最广泛的除草剂之一，已有研究表明其对人和动物具有一定的毒性，为了正确评价该类农药在体内的生物有效性和毒性，分析其在血浆中自由溶解态及其与血清蛋白的相互作用具有重要意义。微损耗固相微萃取是分析生物和环境样品中自由溶解态浓度最常用的方法，然而其存在萃取平衡时间较长、蛋白等大分子基质干扰、带电化合物萃取效率低、萃取纤维价格昂贵且容易损坏等问题。为解决上述问题，本项目拟将磁性固相萃取引入到农药自由溶解态和农药-蛋白相互作用研究中，从磁性限进混合模式萃取介质的制备，进而表征其物理化学性质，并对其吸附农药性能进行评价，研究其对该类农药的吸附行为，探明农药与蛋白之间的相互作用，最后将其用作磁性固相萃取吸附剂实现快速简单地检测血浆中苯氧羧酸类除草剂自由溶解态浓度。本项目的实施不但为研究农药自由溶解态及其与血清蛋白相互作用提供了新方法，还能为评估农药在体内的生物有效性和毒性提供技术支撑。

苯氧羧酸类农药是应用最广泛的除草剂之一，已有研究表明其对人和动物具有一定的毒性，为了正确评价该类农药在环境以及对人体的危害性，分析其在环境水中的浓度分布及其与人血清蛋白的相互作用具有重要意义。本项目采用物理混合、水热法等手段合成了多种功能化的吸附剂，包括磁性的氨基多壁碳纳米管、磁性辛基氨基键合介孔硅胶微球、氨基官能化的金属有机骨架材料等，并对其结构进行了表征。苯氧乙酸类农药是一种疏水的羧酸类分析物，因此这些吸附剂可通过疏水弱阴离子交换作用选择性地萃取样品中的苯氧乙酸类农药。考察了吸附剂与苯氧乙酸类农药及人血清蛋白的相互作用，磁性辛基氨基键合硅胶微球和氨基官能化的金属有机骨架材料的微孔和介孔结构可通过尺寸排阻作用有效地排斥蛋白等大分子；同时，系统研究了氨基官能化的金属有机骨架材料与农药相互作用的萃取热力学和动力学，为研究苯氧乙酸类农药的自由态提供了很好的基础。为了达到高的萃取效率和检测灵敏度，详细优化了样品前处理和分离检测条件。最后，结合新型磁性固相萃取、注射泵辅助分散固相萃取等样品前处理技术及液相色谱-串联质谱分离检测，建立了环境水样中苯氧乙酸类农药的快速、灵敏、简便的分离分析新方法。本项目的实施为苯氧乙酸类农药的吸附剂的设计合成提供了新方法，为研究农药自由溶解态及其与血清蛋白相互作用提供了基础，基本完成了预期研究目标。