Nonaqueous capillary electrophoresis using a titania-coated capillary

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Ordered mesoporous titania films offer unique surface properties.
• Capillary electrophoresis (CE) is a powerful separation technique.
• Nonaqueous solvents present challenges and opportunities in CE.

Purpose of the Study:

• To develop and characterize a titania-coated capillary for nonaqueous CE.
• To investigate the electroosmotic flow (EOF) properties of the coated capillary in various nonaqueous media.
• To evaluate the separation efficiency of alkaloids using the titania-coated capillary.

Main Methods:

• Sol-gel technique for coating capillary with ordered mesoporous titania.
• Investigation of EOF in methanol, formamide, N,N'-dimethylformamide, and methanol-acetonitrile mixtures.
• Nonaqueous capillary electrophoresis (NACE) for alkaloid separation.

Main Results:

• The titania-coated capillary demonstrated distinct EOF behavior dependent on solvent composition, apparent pH (pH*), and electrolytes.
• Effective separation of alkaloids was achieved in the positively charged titania-coated capillary under nonaqueous conditions.
• Comparison showed improved separation with the coated capillary versus uncoated under optimal nonaqueous conditions.

Conclusions:

• Ordered mesoporous titania coatings can significantly influence EOF in nonaqueous capillary electrophoresis.
• The developed titania-coated capillary is a promising tool for nonaqueous separation of alkaloids.
• This approach offers a new avenue for optimizing NACE performance.