乙氧酰胺苯甲酯表面分子印迹聚合物的制备与吸附特性

Preparation and Characterization of Surface Molecularly Imprinted Polymers for Selective Adsorption of Ethopabate

合成功能单体N,O-双异丁烯酰乙醇胺(N,O-bismethacryloyl ethanolamine,NOBE),采用表面分子印迹技术,以硅胶为载体,乙二醇二甲基丙烯酸酯(ethylene glycol dimethacrylate,EGDMA)为交联剂,制备乙氧酰胺苯甲酯(ethopabate,ETP)分子印迹聚合物(molecularly imprinted polymers,MIPs)。采用正交试验方法,对ETPNOBE物质的量比、ETP-EGDMA物质的量比和致孔剂种类3个因素进行考察,结果表明:3个影响因素主次顺序为致孔剂种类>ETP-NOBE物质的量比>ETP-EGDMA物质的量比;当致孔剂为乙腈、ETP-NOBE-EGDMA的物质的量比为1:2:20时,所制备的ETP-MIPs印迹效果最佳。Scatchard模型研究发现存在两类结合位点,高亲和位点与低亲和位点的平衡离解常数K_d和最大表观结合量Q_(max)分别为K_(d1)=1.608μg/mL,Q_(max1)=1.101μg/mg;K_(d2)=0.109μg/mL,Q_(max2)=0.172μg/mg。

The novel functional monomer N,O-bismethacryloyl ethanolamme（NOBE） was synthesized and used to prepare molecularly imprinted polymers（ETP-MIPs） for adsorbing ethopabate by surface molecular imprinting technique using silica gel as the support matrix and ethylene glycol dimethacrylate（EGDMA） as the crosslmkmg agent.Three polymerization conditions including molar ratio of template to functional monomer,molar ratio of template to crosslmkmg agent and porogen type were optimized using an orthogonal array design.The type of porogen was the most important factor,followed by the ratio of template to functional monomer and ratio of template to crosslmkmg agent.The best imprinting efficiency was observed for molecularly imprinted polymers with a molar ratio of ETP to NOBE to EGDMA of 1：2：20 using acetomtnle as the porogen.The Scatchard analysis indicated that there were two classes of binding sites in ETP-MIPs;the equilibrium dissociation constant（Kd） and apparent maximum binding capacity（Qmax） for the high affinity sites and low affinity sites were calculated as follows：Kd1=l.608 μg/mL,Qmax1=1.101 μg/mg;and Kd2=0.109 μg/mL,Qmax2=0.172 μg/mg,respectively.