Potential and current limitations of superficially porous silica as a carrier for polysaccharide-based chiral selectors in separation of enantiomers in high-performance liquid chromatography.

In this study superficially porous silica particles with a nominal pore size of 450 Å and average particle size of 2.6 micrometers was compared to fully porous silica particles with nominal particle size 3 micrometers and nominal pore size 1000 A as carriers for a polysaccharide based chiral selector for the separation of enantiomers in high-performance liquid chromatography. In addition, the effects of chiral selector loading onto the silica support and of column internal dimeter in the case of both, superficially porous and totally porous silica, as well as of the pore size of superficially porous silica on column performance were studied. The dependence of plate height on mobile phase flow rate was also studied and attempts were made for shortening analysis time. The baseline separation of enantiomers of some chiral sulfoxides was obtained within 2.0-4.5 s.