Development and Evaluation of Capillary Electrophoresis Based on Coordination Interaction

In nonaqueous capillary electrophoresis (CE), the electrostatic interactions between additives and analytes can offer additional separation mechanism. Similarly, the dynamic coordination interactions between metal ions and analytes can also be possible of providing separation selectivity. In this work, a new CE mode with applying coordination interaction as separation motivity was developed and it was defined as coordination interaction capillary electrophoresis (CICE). The CICE method was established by using seven arylamides as model compounds and Cu2+, Ni2+, Zn2+ as additives of running medium. The effect of operating conditions such as pH value, nature of metal ion, concentration, and separation voltage were investigated. The conditions of running medium for the separation of arylamides were optimized as 3 mM Cu2+ and 0.1% (v/v) acetic acid in water. The quantitative reliability of CICE, as given by linear range of concentration, correlation coefficient and detection limit, was presented. The potential application of CICE in analysis of real sample was validated by separation of degenerative o-phenylenediamine sample. In addition, good separation results of four sulfonamide compounds were obtained with CICE, demonstrating the great possibilities of CICE as a new, selective, and efficient CE separation mode.