Investigation of Induced Peak Phenomenon in Capillary Electrophoresis with Electrochemiluminescence Detection

Induced peak phenomenon in capillary zone electrophoresis with electrochemiluminescence detection for chiral separation of racemic phenylalanine mixture employing sulfated‐β‐cyclodextrin as chiral selector and acetonitrile as organic additive in the separation buffer was observed. Various experimental parameters influencing the intensity and the position of the induced peak were systematically investigated to find out the truth of the induced peak. Based on the experimental evidence, a reasonable mechanism involved in the formation of the induced peak was proposed. We found out the induced peak resulted from physical interactions between the components in the separation buffer and the injected sample during the electromigration process rather than chemical complexation interactions. Furthermore, suggestions to avoid the appearance of induced peak in capillary zone electrophoresis with electrochemiluminescence detection for chiral separations were presented.