Synthesis and evaluation of an aromatic polymer-coated zirconia for reversed-phase liquid chromatography

We synthesized a novel aromatic polymer-coated zirconia-based RPLC stationary phase by chemical adsorption of a copolymer of chloromethylstyrene and diethoxymethylvinylsilane onto zirconia (CMS/VMS-ZrO₂). Characterization of the pore structure of the support by nitrogen porosimetry and inverse size-exclusion chromatography indicates that CMS/VMS-ZrO₂ maintains the well-defined pore structure of the base material. Flow studies show that CMS/VMS-ZrO₂ has good mass transfer characteristics. The reversed-phase retention characteristics of the new support are comparable to those of conventional silica-bonded phases. We have also evaluated the mechanical, thermal, and pH stability of CMS/VMS-ZrO₂. The results show that CMS/VMS- ZrO₂ is stable over a very wide range of pH (pH = 1-13) and at temperatures as high as 160 °C. Chromatographic separations of some low molecular weight aromatic analytes on CMS/VMS-ZrO₂ and octadecyl-bonded silica phases indicate that there are some subtle but significant differences in the chromatographic selectivity of these two types of phases.