Branched polyethyleneimine‐bonded tentacle‐type polymer stationary phase for peptides and proteins separations by open‐tubular capillary electrochromatography

Abstract

A novel tentacle-type polymer stationary phase covalently modified with branched polyethyleneimine (PEI) was developed for peptides and proteins separations by open-tubular CEC (OT-CEC). The preparation procedure included the silanization of capillary inner wall, in situ graft polymerization and PEI functionalization. A wrinkly polymer surface of multitudinous steric amine groups was evenly formed on the capillary inner wall, and anodic EOF could be gained within a wide pH range of 2.5-7.5. The electroosmotic mobility was examined for its dependence on pH as well as PEI concentrations. Good repeatability was gained with RSD for the migration time of EOF marker within 4.8% and satisfactory chemical stability was validated. Due to the existence of amine groups on the surface of tentacle-type polymer stationary phase, the silanol effect that occurs between the positively charged biomolecules and the silanols of the capillary column was greatly suppressed. Compared with a monolayer-coating capillary, seven enkephalin-related peptides were well resolved on the PEI-bonded column with high efficiencies. Favorable separations of peptides and proteins with high column efficiencies were obtained in 144,000-189,000 and 97,000-170,000 plates/m. Branched PEI-bonded tentacle-type polymer stationary phase has been proven to afford satisfactory retention and resolution of peptides and proteins.

Carboxyl modified magnetic nanoparticles coated open tubular column for capillary electrochromatographic separation of biomolecules

“…The as-prepared OT columns were successfully applied for separation of amino acids, dipeptides and proteins based on the electrophoretic and chromatographic mechanisms. In comparison with other OT columns which aimed at separation of proteins [3,8,[42][43][44][45][46], the procedure for preparation of PDDA@Fe 3 O 4 -COOH MNPs coated OT column was simpler and milder. The Fe 3 O 4 -COOH MNPs coating containing abundant carboxyl groups and Lewis acid sites effectively improved the separation selectivity and restrained the adsorption of proteins on the capillary wall.…”

Synthesis and characterization of new generation open tubular silica capillaries for liquid chromatography

“…Further progress in the development of sol-gel-derived, silica-based layers was achieved by Colón et al with the usage of monomer mixtures like TEOS and C 8 -TEOS for pressure-driven reversed phase OTLC [20][21][22] and OT electrochromatography [23,24]. In the last few years, intensified research on porous layer open tubular (PLOT) columns with polystyrene [25][26][27][28][29][30] and polyacrylate [31][32][33][34][35] based polymeric stationary phases shows the ongoing trend towards miniaturization in LC and renewed interest in open tubular technology. Publications describing the deposition of silica layers in capillaries have become rare, but unmodified silicon dioxide surfaces employed in a chip [36,37] and in single [38] and multipath [39] capillaries have been used to generate enormous efficiencies of up to 1,000,000 theoretical plates in a reasonable time.…”

Polyethyleneimine-grafted boronate affinity materials for selective enrichment of cis -diol-containing compounds

“…Due to a high density of Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/talanta amino groups, PEI polymers can supply a large number of active binding sites for grafting, which can greatly increase the amount of functional ligands in the chemical modification of a polymer surface [19], known as brushes or tentacles. Moreover, PEI significantly improved the hydrophilicity of bonded materials facilitating applications [20] in the separation and detection of biological samples, particularly reducing nonspecific adsorption significantly.…”