Quantitative and qualitative precision improvements by effective mobility-scale data transformation in capillary...

Area of Science:

• Analytical Chemistry
• Separation Science

Background:

• Capillary electrophoresis (CE) data is typically presented on a time scale, which can be affected by variations in electroosmotic flow (EOF).
• Comparing electropherograms across different experimental conditions or over time can be challenging due to potential instability in EOF.

Purpose of the Study:

• To develop a robust data representation for capillary electrophoresis (CE) analysis.
• To enhance both qualitative and quantitative aspects of CE by transforming the time-based x-axis to an effective mobility scale.

Main Methods:

• Transforming the time-based x-axis of electropherograms into an effective mobility scale (μeff-scale).
• Utilizing the electroosmotic flow (EOF) peak or an internal standard of known effective mobility for scaling.
• Analyzing detection signals against effective mobility instead of time.

Main Results:

• The effective mobility scale provides a more accurate representation of velocity-based electrophoretic separation.
• Electropherograms on the μeff-scale allow for direct comparison, independent of column length and voltage.
• Improved peak area reproducibility and precision in quantitative analysis were observed compared to the time-scale integration.

Conclusions:

• The proposed effective mobility scale offers a simple and robust method for improved qualitative and quantitative CE analysis.
• This data representation is particularly valuable for tracking peaks in real samples and comparing runs from different experimental setups.
• The μeff-scale enhances the reliability and comparability of capillary electrophoresis data.