Yang C, El Rassi Z
Department of Chemistry, Oklahoma State University, Stillwater 74078-3071, USA.
Electrophoresis. 1998 Oct;19(13):2278-84. doi: 10.1002/elps.1150191305.
Fused-silica capillary columns having cationic surfactant moieties (CSM) covalently attached to the capillary inner walls were introduced for the separation of proteins by capillary zone electrophoresis (CZE). The CSM capillary coating proved to be useful in the separation of basic and acidic proteins when modified hydroxypropylcellulose (HPC), namely epoxybutane-HPC (EBHPC), was adsorbed to the primary CSM coating, yielding a hybrid coating (i.e., coating consisting of a covalently bound ligand and an adsorbed ligand). The EBHPC layer rendered the capillary surface highly hydrophilic, thus permitting the separation of basic proteins with relatively high plate counts. Also, the CSM coating was useful for the separation of acidic proteins when the capillary wall had, in addition, a negatively charged polymer adsorbed to the surface, e.g., hyaluronic acid. In general, neutral and charged polymeric compounds could be readily adsorbed by the CSM coating, thus altering the zeta potential of the capillary and diminishing solute adsorption to the capillary surface. In other words, the sign of the zeta potential of the capillary surface could be tailored to be of the same sign as the charge of the analytes. Under these conditions, little or no solute-wall interaction could be observed due to electrostatic repulsion. Although the capillary surface was charged, the presence of adsorbed polymer suppressed or, in most cases, even eliminated the electroosmotic flow (EOF).
引入了内壁共价连接有阳离子表面活性剂部分（CSM）的熔融石英毛细管柱，用于通过毛细管区带电泳（CZE）分离蛋白质。当将改性羟丙基纤维素（HPC），即环氧丁烷 - HPC（EBHPC）吸附到初级CSM涂层上时，CSM毛细管涂层被证明可用于分离碱性和酸性蛋白质，从而产生一种混合涂层（即由共价结合的配体和吸附的配体组成的涂层）。EBHPC层使毛细管表面具有高度亲水性，因此能够以相对较高的塔板数分离碱性蛋白质。此外，当毛细管内壁表面还吸附有带负电荷的聚合物（例如透明质酸）时，CSM涂层可用于分离酸性蛋白质。一般来说，中性和带电的聚合物化合物很容易被CSM涂层吸附，从而改变毛细管的zeta电位并减少溶质在毛细管表面的吸附。换句话说，毛细管表面zeta电位的符号可以调整为与分析物电荷的符号相同。在这些条件下，由于静电排斥，几乎观察不到溶质与管壁的相互作用。尽管毛细管表面带电，但吸附聚合物的存在抑制了电渗流（EOF），在大多数情况下甚至消除了电渗流。
