Hydrophilic Interaction Chromatographic Evaluation of Zwitterionic Polymer Grafted Silica Gel Via Multiple Binding Sites

Abstract

A new zwitterionic polymer grafted silica stationary phase, Sil-PZIC, was prepared by bonding polyethylene maleic anhydride molecules on the surface of silica via multiple binding sites, followed ammonolysis of maleic anhydride by nucleophilic substitution reaction with ethylenediamine. The stationary phase was characterized by solid-state NMR, zeta potential analysis and elemental analysis. Using nucleosides and nucleobases as molecular probes, the variation of retention time and separation ability of these model compounds were investigated by varying the chromatographic conditions such as the components of mobile phase, salt concentration, and pH. The results indicated that the retention of the new stationary phase was consistent with hydrophilic partitioning mechanism along with multiple interactions including electrostatic and hydrogen bonding interactions. In addition, saccharides and Amadori compounds were also well separated in Sil-PZIC. All the results indicated the prepared column Sil-PZIC had potential application in polar compound separation.

Keywords: Hydrophilic interaction chromatographyStationary phaseZwitterionic polymerRetention mechanisms