虚拟模板分子印迹微球的制备及其对水中微囊藻毒素的吸附性能

Preparation of analog-molecularly imprinted microspheres and their adsorbent performance for microcystin in aqueous solution

本文以L-精氨酸为模板、丙烯酰胺(AM)为单体,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂以及偶氮二异丁腈(AIBN)为引发剂,采用沉淀聚合法制备了微囊藻毒素分子印迹聚合物.采用量子化学密度泛函理论(DFT)模拟计算以确定模板分子(L-精氨酸)与功能单体(AM)的印迹比例,通过扫描电镜和红外吸收光谱对分子印迹聚合物微球进行表征,并利用平衡吸附实验考察了印迹微球对微囊藻毒素的吸附性能.结果表明,本虚拟模板法制备的印迹微球对MC-LR的吸附符合Langmuir模型,线性拟合得出MIPs的线性回归方程为Ce/Q=3.026×10-4+0.125(r=0.991),由此推导出对MC-LR的最大表观吸附量为80.3μg·g^(-1).实验还表明,印迹聚合物对MC-LR和MC-RR的吸附比非印迹聚合物具有更好的选择性,MIPs对MC-LR的初始吸附速率为58.8μg·g^(-1)·min^(-1),大于非印迹聚合物的初始吸附速率19.6μg·g^(-1)·min^(-1),具有选择性富集水体中MC-LR和MC-RR等微囊藻毒素的应用前景.

Molecularly imprinted polymers for microcystins were synthesized by precipitation polymerization method using L-arginine as the template,acrylamide（ AM） as monomer,N,N＇-Methylenebisacrylamide as crosslinker and azodiisobutyronitrile as initiator. The imprinting ratio of L-arginine and acrylamide（ AM） was calculated based on the Density Functional Theory（ DFT）method,and the resulting composites were characterized by scanning electron microscopy（ SEM）and Fourier transform infrared（ FT-IR） analysis. The selectivity of the MIPs for the adsorption of microcystin-LR was demonstrated by equilibrium adsorption experiments. Results showed that the adsorption isotherms of analog-molecularly imprinted microspheres to MC-LR can be described by the Langmuir adsorption model,and the linear regression equation was fitted as Ce/ Q = 3. 026 × 10^（-4）＋0.125（ r = 0.991）,and the apparent maximum adsorption capacity for MC-LR was 80.3 μg·g^（-1）. It was proved that the MIPs had better molecular fragment recognition ability for MC-LR and MC-RR than for of NIPs. The imprinted microspheres showed rapid adsorption dynamic process because theinitial adsorption rate of MIPs and NIPs to MC-LR were 58.8,19.6 μg·g^（-1）·min^（-1）,respectively. This polymers can be used for selective extraction of [arginine]-microcystins in water using solid phase extraction method in future.