Characterization and evaluation of magnesia-zirconia supports for normal-phase liquid chromatography

A new packing based on a magnesia-zirconia composite was synthesized as rig id microparticles (4-6 mu m) by a sol-gel process. The magnesia-zirconia co mposite exhibits a larger specific surface area, larger specific pare volum e, better pore connectivity and more uniform pore size distribution than pu re zirconia prepared under the same conditions. The chromatographic perform ance of magnesia-zirconia and zirconia packings in normal-phase HPLC was ev aluated using binary mobile phases (dichloromethane/cyclohexane, chloroform /cyclohexane and isopropanol/cyclohexane) and acidic, neutral and basic com pounds as solutes. The efficiency of columns packed with the magnesia-zirco nia composite was higher than that of zirconia.