Ultrahigh-voltage capillary zone electrophoresis.

Area of Science:

• Analytical Chemistry
• Separation Science
• Biochemistry

Background:

• Capillary electrophoresis (CE) is a powerful separation technique.
• Enhancing separation power in CE is crucial for complex sample analysis.
• Limitations exist in achievable separation efficiency with conventional voltage limits.

Purpose of the Study:

• To demonstrate the feasibility of extending applied potential in capillary electrophoresis.
• To increase the separation power of capillary electrophoresis systems.
• To investigate the impact of ultrahigh voltages on CE performance.

Main Methods:

• Modification of a commercial 30-kV power supply to achieve up to 120 kV.
• Development of a unique electrical shielding system to prevent discharge.
• Electrophoretic separation of peptide standards and protein digests.

Main Results:

• Achieved theoretical plate counts ranging from 2.7 to 6.1 million for peptides at 120 kV.
• Demonstrated a linear increase in theoretical plates with applied voltage.
• Observed resolution increasing with the square root of applied voltage, consistent with theory.

Conclusions:

• Ultrahigh-voltage capillary electrophoresis significantly enhances separation efficiency.
• The developed system overcomes breakdown issues associated with high voltages.
• This approach offers a pathway to dramatically improve CE separation power for complex mixtures.