Simultaneous separation of cations and anions in capillary electrophoresis

• We provide a contemporary guide to concurrent capillary electrophoresis (CE).
• We describe the simultaneous separation of anions and cations in CE.
• We evaluate the benefits and the drawbacks of the different approaches to CE.
• We specify the instrumental requirements of different approaches to CE.
• Dual capillary electrophoresis is a promising method to be used in the future.

With capillary electrophoresis, it is desirable to have simultaneous determination of cations and anions, which avoids costs and time spent on separate analyses, so concurrent approaches to separation gained popularity in recent years. We review the different strategies employed for the simultaneous separation and determination of cations and anions, including the use of complexing agents, micelles, two injectors, dual detectors, or two capillaries. We give an overview of the methods reported to date, and their benefits and drawbacks, and we evaluate the instrumental requirements of the different approaches.