Qualitative and quantitative aspects of time-, charge-, and mobility-based electropherograms.

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) relies on high-voltage power supplies to control analyte migration velocity.
• Controlling voltage or current impacts electropherogram quality, affecting analyte identification and quantification.
• Traditional electropherograms record detector signal versus time, neglecting charge and mobility domains.

Purpose of the Study:

• To evaluate two approaches for controlling electrophoretic migration: voltage-controlled and current-controlled modes.
• To assess the impact of these control modes on time-, charge-, and mobility-based electropherograms.
• To determine the optimal strategy for enhancing analyte identification and quantification in CE.

Main Methods:

• Utilized mathematical modeling and experimental results to analyze electrophoretic migration control.
• Compared voltage-controlled and current-controlled modes in capillary electrophoresis.
• Investigated the generation and utility of time-, charge-, and mobility-based electropherograms.

Main Results:

• Current-controlled mode demonstrated superiority over voltage-controlled mode for CE separations.
• Monitoring electrophoretic current is crucial for improving analyte identification and quantification, especially when current control is not feasible.
• Consistent current monitoring facilitates the implementation of charge-based electropherograms and mobility spectra.

Conclusions:

• Charge-based electropherograms offer more reproducible peak positions and robust peak areas compared to time-based electropherograms.
• Mobility spectra provide enhanced information about analyte mobility and can be used for quantitation with high plate numbers (>10^3).
• Current-controlled mode and monitoring electrophoretic current are key strategies for optimizing capillary electrophoresis performance.