Electroneutral silica-based hybrid monolith for hydrophilic interaction capillary electrochromatography

Area of Science:

• Chromatography
• Materials Science
• Electrochemistry

Background:

• Developing robust stationary phases is crucial for advanced separation techniques.
• Hydrophilic interaction chromatography (HILIC) offers unique selectivity for polar compounds.
• Capillary electrochromatography (CEC) combines chromatographic separation with electroosmotic flow (EOF).

Purpose of the Study:

• To develop a novel, electroneutral, polar silica-based hybrid monolith.
• To evaluate its performance in hydrophilic interaction capillary electrochromatography (HI-CEC).
• To assess its separation capabilities for diverse analytes.

Main Methods:

• In situ copolymerization of 2-hydroxyethylmethacrylate (HEMA) and polyhedral oligomeric silsesquioxane methacryl substituted (POSS-MA).
• Fabrication of a silica-based hybrid monolith.
• Performance evaluation using HI-CEC with various neutral and charged analytes.
• Morphological characterization of the monolith.

Main Results:

• The hybrid monolith exhibited good mechanical stability and permeability.
• A significant cathodal EOF was observed despite the absence of ionizable groups.
• Successful separation of neutral (amides, phenols) and charged (nucleic acid bases, nucleosides, enkephalins) analytes.
• High separation efficiencies achieved, up to 145,000 plates/m for alkaloids and 75,000 plates/m for enkephalins.

Conclusions:

• The developed silica-based hybrid monolith is suitable for HI-CEC applications.
• The material offers effective separation of a wide range of analytes.
• This novel monolith provides a promising platform for advanced chromatographic separations.