In this study, a series of zwitterionic phosphorylcholine functionalized monolithic
columns were fabricated via the thermally initiated co-polymerization of 2-methacryloyloxyethyl
phosphorylcholine (MPC) and different hydrophilic crosslinkers, including 1,4-bis(acryloyl)piperazine
(PDA), N,N'-methylenebisacrylamide (MBA) and 2-(methacryloyloxy)ethyl-[N-(2-methacryloyloxy)ethyl]phosphorylcholine
(MMPC). The physicochemical and chromatographic properties of these MPC functionalized
monoliths, including column morphology, pore size distribution, permeability, column
efficiency, retention mechanism and ζ-potential analysis, were systematically compared.
Furthermore, the influence of the crosslinker on the chromatographic performance of
these MPC functionalized monoliths was evaluated. The chromatographic results indicate
that the polarity of MPC functionalized monoliths may be related to the polarity of
the crosslinker, which further affects the column selectivity and efficiency. A particularly
high column efficiency (88,000 plates/m) was obtained on the novel poly(MPC-co-MMPC)
monolith at optimum linear velocity using thiourea as test analyte. Compared to the
poly(MPC-co-MBA) and poly(MPC-co-PDA) monoliths, the poly(MPC-co-MMPC) monolith exhibited
higher separation selectivity for polar analytes, including nucleobases, nucleosides
and benzoic acid derivatives. Moreover, 24 N-glycopeptides could be detected after
enrichment with the poly(MPC-co-MMPC) versus 19 and 10 N-glycopeptides with the poly(MPC-co-MBA)
and poly(MPC-co-PDA) monoliths, and no N-glycopeptide without enrichment. Therefore,
MMPC has a great potential as a new and alternative hydrophilic crosslinker for the
development of zwitterionic polymeric monoliths.