基于离子液体的水相印迹材料构建及其对痕量抗生素类PPCPs的识别应用

The synthesized molecularly imprinted polymers with general functional monomers showed high special recognization performance, but the selectivity was poor in aqueous media because the interaction beteween the template and monomer could be disturbed by water molecule. Therefore, it is very essential to develop a new special monomer to prepare molecularly imprinted polymers which could recognize target molecules effectively in aqueous media. The aim of this work was to prepare a series of special ionic liquids with functional groups, which were used as functional monomer to prepare pharmaceuticals and personal care products surface molecularly imprinted polymers in aqueous system. The microstructure and morphology of polymers were characterized. The specific adsorption performance of the molecularly imprinted polymers was tested by the adsorption isotherms, kinetic curve, and selective adsorption experiments. The inherent relationship between the material structure and adsorption performance is also discussed, and the adsorption mechanism will be analyzed from the study of chemical structure of ionic liquids, binding site, and the interaction of π-π, ion dipole and hydrogen bonding between template and functional monomer. Based on these results, the prepared surface imprinted polymers were used as solid phase extractant, and the parameters such as the binding capacity, elution solvent, and its regeneration and recyclability were investigated to value the performance of selective separation. Thereafter, new methods for rapid separation and determination of trace level of pollutants will be established based on MIP-SPE coupled with chromatography determinations. It is significant to provide the basic data for resolving the application of imprinted polymers in aqueous samples.

常规功能单体制备的印迹材料在有机相具有特异识别能力，但在水相中因极性水分子的干扰而难以发挥优势，因此，开发新型功能单体，以此构建在水相目标靶向精准的印迹材料是十分必要的。本项目利用离子液体强极性、结构可设计、不挥发的特点，拟合成若干种新型离子液体功能单体，借助于π-π、离子偶极等抗极性分子干扰的强作用力，制备对水相抗生素类PPCPs具有高效识别能力的表面印迹聚合物；通过对聚合物稳定性及选择性识别能力等参数的考察，分析离子液体功能单体的功能性基团与目标物的结合方式，认识材料结构与吸附性能之间的关系，阐明聚合物在水相中的选择性识别机理；在此基础上，制作固相萃取微分离柱，通过考察其吸附容量、稳定性及再生性等参数，建立水相中痕量抗生素类PPCPs的分子印迹-固相萃取-色谱分析检测体系。该研究为解决分子印迹材料在水相的应用提供基础研究数据和理论支撑，对复杂样品的前处理具有重要的学术和实际意义。

本项目通过开发、设计合成新型的离子液体功能单体，分别以水、甲醇-水、乙醇等强极性溶剂为介质，研发了9种对强极性或水相介质中抗生素类PPCPs具有高效识别能力的印迹聚合物新材料。分析了不同功能基团、不同类型的离子液体、抗生素类型、萃取温度等对印迹聚合物材料的微观结构、理化性质和选择性吸附性能的影响规律，考察了离子液体印迹聚合物材料对目标污染物的选择识别能力、吸附容量、吸附热力学等参数，提出了可能的选择性识别机理。研究结果表明，离子液体印迹聚合物材料对强极性环境中目标物具有优良的选择性吸附能力，可以有效识别强极性及富水介质中痕量磺胺类、酚类、喹诺酮类、大环内酯类和β-内酰胺类抗生素，选择性印迹因子达1.44-30.9，最大吸附容量在8.6-30.41 mg g-1之间，对复杂环境中痕量磺胺类、酚类、喹诺酮类、大环内酯类和β-内酰胺抗生素的回收率达83%以上，显著优于传统分子印迹材料在强极性介质的吸附性能；制备的材料传质速度较快，在30-100 min即可达到吸附平衡；吸附机理以氢键、π-π键以及静电等非共价键形式为主；不同类型和不同官能团的离子液体功能单体对印迹材料在水相中的选择性吸附能力影响不同，可以通过调控离子液体功能单体类型，改善印迹聚合物材料的水相识别性能；所制备的离子液体印迹聚合物材料具有较好的亲水性和稳定性，不仅极大减少了高毒性有机溶剂的使用，同时也显著提高印迹材料在富水介质中的特异识别能力，且便于再生循环使用，为水相体系中痕量抗生素类PPCPs的高效分离分析提供技术支撑和科学依据。