Simultaneous determination of five metal ions by on-line complexion combined with micelle to solvent stacking in capillary electrophoresis

A direct on-line complexion combined with micelle to solvent stacking method was proposed for simultaneous determination of metal ions by capillary electrophoresis coupled diode array detector. During the experiment, a plug of complexing agent was first injected to the inlet of capillary, followed by introducing the micelle-bound metal ions. Then the metal ions produced a micelle-to-solvent stacking effect and interacted with the complexing agent under a positive voltage. Continued application of voltage, the analytes were effectively focused and separated in the capillary zone electrophoresis . Repeatability was ranged from 1.89% to 1.94% for the migration time. The detection limits were 2.66–27.9 ng mL -1 for Ni 2+ , Co 2+ , Cu 2+ , Hg 2+ and Cd 2+ . Furthermore, the developed method showed a great potential for the determination of metal ions in the crayfish, beebread and Dendrobium officinale samples.