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 Ni2+, Co2+, Cu2+, Hg2+ and Cd2+. Furthermore, the developed method showed a great potential for the determination of metal ions in the crayfish, beebread and Dendrobium officinale samples. [Display omitted] •MSS combined with on-line complexion method was presented.•The proposed method was used for the determination of metal ions.•The method was sensitive, efficient, easy-operating and environment-friendly.•The method was applied to the analysis of real samples.