基于改性硅胶“接枝”聚合法制备高特异性红霉素固相萃取材料及其评价

Preparation and evaluation of erythromycin solidphase extraction materials based on modified silica gel “grafting” polymerization

目的采用硅胶表面分子印迹技术,制备印迹红霉素分子的聚合物材料,将其作为固相萃取介质,对自来水中添加的红霉素(erythromycin,EM)进行了富集纯化处理。方法制备中采用γ-氨丙基三甲氧基硅烷(3-aminopropyltrimethoxysilane,AMPS)作为硅胶(SiO2)改性剂,将功能单体甲基丙烯酸(methacrylic acid,MAA)接枝到AMPS-SiO2表面,形成聚甲基丙烯酸接枝硅胶(polymer methacrylic acid/SiO2,PMAA/SiO2)。最后,加入模板分子红霉素和交联剂乙二醇二甲基丙烯酸酯(2-ethanediol dimethacrylate,EDMA),聚合得到表面包被有红霉素印迹聚合物的硅胶材料(EMMIP-PMAA/SiO2)。通过电镜扫描(scanning electron microscope,SEM)和粒径测定对EM-MIPPMAA/SiO2物理性状进行了表征;通过动、静态吸附和选择性吸附试验研究了PMAA/SiO2和EMMIP-PMAA/SiO2对红霉素的结合性能和分子识别特性。结果 EM-MIP-PMAA/SiO2对红霉素显示了良好的吸附能力,最大吸附量可达104 mg·g-1,吸附约240 min达到吸附平衡;与竞争分子罗红霉素相比,表面印迹聚合物对模板分子红霉素显示了高的选择吸附能力;将其作为固相萃取介质对于生物样品中的分析物具有良好的纯化作用。结论像MIP-PMAA/SiO2这类新的印迹材料将会广泛应用于生物样品的监测分析工作,并且对于环境保护也具有一定实用意义和价值。

Objective To prepare erythromycin-imprinted polymeric material by using silica surface molecularly imprinting method,and to apply the obtained polymer as solid phase extracting agent for the purification of erythromycin（EM） in tap water.Methods γ-Ammonia propyl three methoxyl silicane（AMPS） was employed to graft functional monomer-methacrylic acid（MAA） onto the surface of silica gel,producing the grafted silica gel named PMAA/SiO2.Polymerization was initiated with existence of erythromycin and crosslinker-ethylene glycol dimethacrylate（EDMA）,and silica material covered with EM-imprinted polymeric layer was prepared,which is named as EM-MIP-PMAA/SiO2.The material was characterized by scanning electron microscope（SEM） and particle size analysis.Static binding test,dynamic binding test and selective binding test were applied to investigate the adsorption and recognition merits of the obtained polymers.Results The results showed that the maximum adsorption capacity of the polymer was 104 mg·g-1and the time needed to reach adsorption equilibrium was 240 min.Compared with the competing molecule-chloramphenicol,EM-MIP-PMAA/SiO2 displayed higher recognition ability to the template molecule-EM.Application of EM-MIP-PMAA/SiO2 as solid-phase sorbent exhibited its potential in purification and enrichment of target molecules in biological samples.Conclusions Such new molecularly imprinted materials are expected to play an important role in analysis and monitor of biological samples,and possess practical significance and value in environmental protection.