Electrokinetic flow through packed capillary columns

This paper is a theoretical study of electroosmotic flow through various mo del packings to understand the mechanisms of capillary electrochromatograph y (CEC) and to take full advantage of CEC. Two different equations for elec troosmotic flow velocity are described and compared with each other through two- and three-dimensional figures. The optimal channel diameter in the co mmon ionic strength range is determined. The importance of ionic strength a nd packing microstructure is further verified. The properties of various pa cking beets are compared and an "ideal" packing, with parallel flow channel s and minimum tortuosity, is suggested. The reasons that CEC has not achiev ed the predicted separation efficiency are pointed out. This study sheds li ght on approaches to achieve the high separation efficiency and selectivity available by CEC. (C) 1999 John Wiley & Sons, Inc.