Rapid fabrication of zwitterionic sulfobetaine vinylimidazole-based monoliths via photoinitiated copolymerization for hydrophilic interaction chromatography

Zwitterionic sulfobetaine-based monolithic stationary phases have attracted increasing attention for their use in hydrophilic interaction chromatography. In this study, a novel hydrophilic polymeric monolith was fabricated through photo-initiated copolymerization of 3-(3-vinyl-1-imidazolio)-1-propanesulfonate (SBVI) with pentaerythritol triacrylate using methanol and tetrahydrofuran as the porogenic system. Notably, the duration for the preparation of this novel monolith was as little as 5 min, which was significantly shorter than that required for previously reported sulfobetaine-based monoliths prepared via conventional thermally initiated copolymerization. Moreover, these monoliths showed good morphology, permeability, porosity (62.4%), mechanical strength (over 15 MPa), column efficiency (51,230 plates/m), and reproducibility (relative standard deviations for all analytes were lower than 4.6%). Mechanistic studies indicated that strong hydrophilic and negative electrostatic interactions might be responsible for the retention of polar analytes on the zwitterionic SBVI-based monolith. In particular, the resulting monolith exhibited good anti-protein adhesion ability and low nonspecific protein adsorption. These excellent features seem to favor its application in bioanalysis. Therefore, the novel zwitterionic sulfobetaine-based monolith was successfully employed for the highly selective separation of small bioactive compounds and the efficient enrichment of N-glycopeptides from complex samples. In this study, we prepared a novel zwitterionic sulfobetaine-based monolith with good performance and developed a simpler and faster method for preparation of zwitterionic monoliths.