磁性MFe2O4@FILs泡腾萃取体系的构筑、相关机理及在水体极性污染物分析中的应用

Utilization of magnetic ionic liquids in microextraction methods mainly focuses on their hydrophilic/hydrophobic extraction performance. However, it is less involved in use of their special functions and related mechanisms. Our previous investigations demonstrated that ionic liquids with cyclohexamine phenyl borate could form ring structure with polar chemicals (PCs), yielding strongly fluorescence-enhancing effect. With regret, it remains unclear for the detailed mechanism on the above fluorescence-sensitizing phenomenon and the functional changes due to magnetization. Based on these considerations, this proposal aims to perform the following researches: (1) A series of fluorescence-enhancing ionic liquids (FILs) will be synthesized and characterized by means of IR, NMR and MS data. The effects of structural changes in FILs on fluorescent behaviors of PCs will be elucidated by a series of theories such as twisted charge transfer and special solvent action; (2) FILs are integrated with magnetic microsphere to construct magnetic ionic liquids (MFe2O4@FILs) for the sake of convenient separation and collection in microextraction procedures under field conditions. In order to realize the molecular design regulation and prediction of FILs, many kinds of theories and model equations will be utilized to clarify the changes in extraction performance for PCs and the related molecular mechanisms from magnetization of ionic liquids; and (3) MFe2O4@FILs is utilized in effervescence-based system to realize effervescent tablet microextraction and sensitive fluorescence determination of trace PCs. In microextraction procedures, CO2 resulting from acidic and alkaline reaction is used as dispersive power source. As a result, the newly developed microextraction method can satisfy the technological requirements for the determination of trace polar pollutants, which are difficult in their pretreatment and analyses by means of routine methods. At the same time, we will realize the convenient and multi-functional deep application of ionic liquids in the field of microextraction.

磁性化离子液体在微萃取中的应用主要涉及其亲/疏水萃取效能，而对其特殊功能化的利用及相关机理少有涉及。我们前期工作证实苯基硼酸环己胺类离子液体能与多种极性化合物（PCs）形成环状结构，导致强荧光增敏效应的发生，但其内在机制及磁性化后的功能变化尚不明晰。为此，本项目拟制备系列取代基的荧光增敏离子液体（FILs），探索其结构变化对PCs所产生的荧光调控，综合运用荧光探针和特殊溶剂效应等理论，解释FILs的强荧光增敏机理；将其与磁性微球结合，构筑磁性化MFe2O4@FILs，便于野外萃取后的分离和收集；利用多种理论和模型阐明磁性化后的萃取效能变化及分子机理，实现FILs萃取效应的分子设计调控和预测；应用于泡腾体系，利用酸碱反应产生的CO2作为分散动力源，构建适合于水体PCs前处理的泡腾片剂微萃取和灵敏荧光分析，满足野外难分析极性污染物检测的技术需求，实现离子液体在微萃取领域的方便和多功能深度应用。

根据国基项目（21876125）的合同要求，本项目主要任务是开发各种磁性荧光离子液体，并将其应用于开发磁性泡腾片剂，制备各种具高吸附效能，对部分污染物具有荧光增敏或猝灭效应的特异功能化离子液体泡腾片，应用于水体中污染物的灵敏荧光分析。经过4年的研究，获得如下成果：（1）以1-萘甲酸钠为前驱体合成了双阳性荧光离子液体，用于检测环境水体中的4-硝基苯酚，具有高荧光灵敏度和良好选择性；（2）制备了溴代双阳性离子液体作为提取剂，铁酸镍作为吸附和回收剂，利用泡腾反应的强力分散作用，开发了基于双阳性离子液体的磁性泡腾片剂微萃取技术；（3）合成了季铵盐类聚合物离子液体，将其用于泡腾片剂前驱体，开发了泡腾分散微萃取技术；（4）合成了高效磁性复合纳米材料吸附剂，采用泡腾辅助磁固相萃取，对水果样品中的有机磷农药进行萃取和预浓缩；（5）开发了三种核壳型磁性共价有机骨架材料（MCOFs），将MCOFs作为磁分离剂和独立的吸附剂用于泡腾反应增强微萃取技术中，构建了液体基质样品中内分泌干扰物的萃取和富集技术；（6）合成了限域离子液体-共价有机框架复合材料（MCOF@IL），将其作为吸附剂构建磁固相分散微萃取技术，应用于食用油中多环芳烃的分析检测。项目的预期目标：发表SCI论文6-10篇，其中IF>5.0的SCI论文2篇以上；申请国家专利1-2项；培养硕士研究生3-5名。完成情况：经过4年的研究，共发表论文17篇，其中SCI论文16篇，其中IF>5.0的SCI论文8篇，中文论文1篇，主持人均为第一或通讯作者。获批授权发明专利6项，培养硕士研究生10名。故项目的所有预期目标均已超额完成。所开发各种磁性泡腾片产品在长三角地区的多家检测公司实验室得到初步应用，为今后的推广奠定了一定的理论和实践基础。