Stable neutral double hydrophilic block copolymer capillary coating for capillary electrophoretic separations

Area of Science:

• Analytical Chemistry
• Materials Science
• Polymer Chemistry

Background:

• Electroosmotic flow (EOF) in capillaries can complicate separations.
• Developing stable, neutral coatings is crucial for reproducible analytical results.
• Dynamic coatings offer advantages in preparation and regeneration.

Purpose of the Study:

• To develop a neutral, dynamic coating for suppressing electroosmotic flow.
• To evaluate the stability and performance of the coating for analyte separation.
• To demonstrate the coating's utility in biological and protein analysis.

Main Methods:

• Synthesis of a quaternized diblock copolymer: poly(N-methyl-2-vinylpyridinium iodide-block-ethylene oxide).
• Application of the copolymer as a dynamic coating on capillary walls.
• Measurement of electroosmotic flow and coating stability across a pH range (4.0-10.5).
• Separation of analytes including beta-blockers, basic proteins, and lipoproteins.

Main Results:

• The copolymer coating effectively created a neutral capillary surface with ultralow electroosmotic flow (+2.0 ± 4.5 × 10(-10) m(2)/Vs).
• The coating demonstrated high stability over 8 days and across a pH range of 4.0-10.5.
• Successful separation of diverse analytes, including proteins and lipoproteins, was achieved.
• The coating exhibited simple preparation, fast regeneration, and automation capabilities.

Conclusions:

• Quaternized diblock copolymers provide an effective neutral, dynamic coating for suppressing electroosmotic flow.
• The developed coating is stable, easy to prepare and regenerate, and suitable for various separation applications.
• This technology holds significant potential for protein analysis and biological interaction studies under physiological conditions.