Ratnayake C K, Regnier F E
PerSeptive Biosystems Inc., Framingham, MA 01701, USA.
J Chromatogr A. 1996 Aug 30;743(1):15-23. doi: 10.1016/0021-9673(96)00355-x.
A silica-based, polyacrylate ion-exchange stationary phase has been prepared using Ce(IV) as the initiator. Analysis of the physical properties of the polymeric layer separated from the silica surface indicates that the polymeric coating is cross linked to some extent. The polymerization carried out at different concentrations of Ce(IV) demonstrated that the effective surface area can be increased by lowering the Ce(IV) concentration at higher monomer concentrations of the reaction mixture. These materials are quite reproducible and of high electrostatic binding capacity; 1.485 mumol/m2. The electrostatic binding capacity of a non-polymeric stationary phase reached the theoretical limit for a monolayer (0.16 mumol/m2). However, the covalent binding capacity of the same stationary phase was only 50% of the electrostatic binding capacity. The same trend was observed in all the polymeric stationary phases tested. This shows that the mechanism of protein binding in polymeric and conventional stationary phases is similar, and multilayer electrostatic binding is highly unlikely in these sorbents examined. Z numbers revealed that the contact area of the protein is independent of the polymeric character of the stationary phase and therefore, the increased loading of these polymeric stationary phases is due to the increased surface area.
以铈（IV）为引发剂制备了一种基于二氧化硅的聚丙烯酸酯离子交换固定相。对从二氧化硅表面分离出的聚合物层的物理性质分析表明，聚合物涂层在一定程度上发生了交联。在不同浓度的铈（IV）下进行的聚合反应表明，在反应混合物中单体浓度较高时，降低铈（IV）浓度可增加有效表面积。这些材料具有良好的重现性和高静电结合容量，为1.485 μmol/m²。非聚合固定相的静电结合容量达到了单层的理论极限（0.16 μmol/m²）。然而，同一固定相的共价结合容量仅为静电结合容量的50%。在所有测试的聚合物固定相中均观察到相同的趋势。这表明聚合物固定相和传统固定相中蛋白质结合的机制相似，在这些所研究的吸附剂中极不可能发生多层静电结合。Z值表明蛋白质的接触面积与固定相的聚合物特性无关，因此，这些聚合物固定相负载量的增加是由于表面积的增加。
