Short communicationBridged polysilsesquioxane-based wide-bore monolithic capillary columns for hydrophilic interaction chromatography

- Silica-based monolithic capillary columns (0.32 mm × 150 mm) were prepared.
- Columns were evaluated in HILIC mode.
- Separation of nucleobases, nucleosides, and 2-deoxynucleosides was achieved.
- HILIC separation of native and labeled carbohydrates is presented.

The synthesis and characterization of large-bore silica-based monolithic capillary columns (0.32 mm × 150 mm) are presented. Columns were prepared by acidic hydrolysis of a mixture containing tetramethoxysilane (TMOS) and 1,2-bis(trimethoxysilyl)ethane (BTME) in different molar ratios in the presence of polyethylene glycol and urea. The monoliths were modified by zwitterionic monomer [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide via 3-(trimethoxysilyl)propyl methacrylate. Prepared stationary phases were evaluated by scanning electron microscopy and chromatographic separation of nucleobases and their derivatives in the HILIC mode. The best chromatographic results were obtained with the column prepared from the reaction mixture containing BTME and TMOS in a 1:4 molar ratio. The permeability of such column reached 1.68 × 10−14 m2 and the efficiency, expressed as a height equivalent of the theoretical plate, did not exceed 10.5 μm for the tested compounds. The columns were successfully applied to HILIC separation of native and labeled oligosaccharides and glycans released from bovine ribonuclease B and human immunoglobulin G.