Capillary electrophoresis (CE) has rapidly gained great interests among researchers in many different fields. One of these areas is the separation of small ions such as inorganic cations[1-9], anions[10-16], and low Mr organic molecules[17-20]. However, as the separation of ions by CE is depended on the difference in electrophoretic mobilities of the ions, and this difference for some of them are very small. Thus, a background electrolyte (BGE) system must be selected to modify the mobilities of the analyte ions, e.g., the actual mobilities of some alkali, alkaline earth metal and ammonium cations are very similar[21].