孔雀石绿磁性印迹聚合物的制备及其分离应用研究

Preparation of malachite green magnetic molecularly imprinted polymers and its application in separation

以Fe3O4作为磁性载体包覆二氧化硅,并通过表面修饰引入碳碳双键,然后采用分子印迹技术,以孔雀石绿为模板分子,α-甲基丙烯酸和4-乙烯基吡啶作为双功能单体,乙二醇二甲基丙烯酸脂为交联剂,通过偶氮二异丁腈引发制备孔雀石绿的磁性印迹聚合物(MMIPs)并对单体和模板分子比例进行优化;分别采用红外光谱(FTIR)、振动样品磁强计(VSM)和透射电子显微镜(TEM)等仪器分析手段,对MMIPs的物理性质及结构进行表征;采用平衡吸附、动力学吸附和选择性吸附实验考察了材料对孔雀石绿的特异性识别能力;运用Scatchard分析,模拟得出磁性印迹聚合物具有两类不同的结合位点,其解离常数分别为1.469 mg/L和8.518 mg/L,对孔雀石绿的最大表观吸附量分别为2.97 mg/g和6.02 mg/g;将该材料应用在鱼肉样品中孔雀石绿及其代谢物隐色孔雀石绿的分离富集,经过对提取液的磁性固相萃取,在低浓度下(2,5,10μg/kg),孔雀石绿和隐色孔雀石绿的样品加标回收率都在合理范围内。

The magnetic molecularly imprinted polymers （MMIPs） were prepared using malachite green（MG） as template molecule, methacrylie acid and 4-vinyl pyridine as co-monomers, ethylene dimethacrylate as crosslinker and Fe3 04 as magnetic carrier with necessary surface modification. The resultant MMIPs were characterized by Fourier transform infrared spectrometry, vibrating sample magnetometer and transmission electron microscope. Series of adsorption equilibriums with Scatchard analysis, adsorption kinetics experiment and selective adsorption experiment were adopted to evaluatethe absorption capability of MMIPs. Scatchard analysis revealed that there were two kinds of binding sites in the obtained MMIPs with the dissociation constants of 1. 469 mg/L and 8. 518 rag/L, and the apparent maximum adsorption capacities of 2.97 mg/g and 6. 02 mg/g. Furthermore, as a magnetic solid-phase extraction adsorbent for the extraction of MG and its residues in spiked fish sample of different standard level, the result showed that the MMIPs could separate and enrich the trace amounts of MG and its residueswith the recovery and RSD in an acceptable range.