Comparison of the thermodynamic properties of particulate and monolithic columns of molecularly imprinted copolymers
Comparison of the thermodynamic properties of particulate and monolithic columns of molecularly imprinted copolymers
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DOI：
10.1021/ac0401218
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发表时间：
2005-01-01
影响因子：
7.4
通讯作者：
Guiochon, G
中科院分区：
文献类型：
--
作者：
Kim, HJ;Guiochon, G
多种聚合技术可用于制备分子印迹共聚物（MIPs），以通过HPLC分离对映体。不幸的是，缺乏热力学和动力学数据表征的印迹聚合物制备这些不同的技术阻止了一个最适合于特定应用的合理选择。研究并比较了两种不同方法制备的Fmoc-L-色氨酸分子印迹聚合物的热力学性质。第一种是原位聚合方法，得到整体柱（整体MIPs），第二种是传统的方法，得到散装MIPs。这两种不同的分子印迹聚合物的热力学性质的检查表明，三种类型的结合位点共存于其表面上。最高能量位点仅吸附印迹分子或模板。大多数的中间能量网站吸附的模板和它的对极，虽然他们中的一部分可能只吸附模板。最后，最低能量的网站提供非选择性的相互作用的模板和它的对映体。在非印迹共聚物上，只有两种类型的位点。高能量位点的能量略低于MIP的中间位点，而低能量位点的性质接近MIP上最低能量位点的性质。整体MIP具有比本体MIP更少的非选择性位点。然而，制备整体式MIPs所需的极性致孔剂对对对映体分离产生负面影响。
A variety of polymerization techniques can be used to prepare molecularly imprinted copolymers (MIPs) for the purpose of the separation of enantiomers by HPLC. Unfortunately, the lack of thermodynamic and kinetic data characterizing the imprinted polymers prepared by these different techniques prevents the rational choice of the one most suited for a specific application. We investigated and compared the thermodynamic properties of copolymers imprinted for Fmoc-L-tryptophan and prepared by two different methods. The first was an in situ polymerization method that gives monolithic columns (monolithic MIPs), the second, a traditional method giving bulk MIPs. Examination of the thermodynamic properties on these two different MIPs showed that three types of binding sites coexist on their surface. The highest energy sites adsorb only the imprinted molecule or template. Most of the intermediate energy sites adsorb both the template and its antipode, although part of them may adsorb only the template. Finally, the lowest energy sites provide nonselective interactions of both the template and its antipode. On the nonimprinted copolymer, there are only two types of sites. The high-energy sites have a slightly lower energy that the intermediate sites of the MIPs, and the low-energy sites have properties close to those of the lowest energy sites on the MIPs. The monolithic MIPs have fewer nonselective sites than the bulk MIPs. However, the polar porogen that is needed to prepare the monolithic MIPs negatively affects the enantiomeric separation.