Comparative performance of capillary columns made with totally porous and core–shell particles coated with a polysaccharide-based chiral selector in nano-liquid chromatography and capillary electrochromatography

In this study two types of silica particles, one fully porous and the other superficial porous (core–shell or fused-core) were modified with a polysaccharide-type chiral selector and evaluated for the separation of enantiomers in nano-liquid chromatography (nano-LC) and capillary electrochromatography (CEC). The major goal of this project was to critically evaluate the contribution of the “flow through particles” to enhancing peak efficiency in CEC compared to nano-LC. The better performance of fused-core silica particles compared with silica particles of comparable size but having through pores questions the previous assumption that “flow through particles” is the major contributor to enhancing peak efficiencies observed in CEC. In addition, based on the results of this study it is suggested that contrary to previous reports on core–shell particles behaving poorly in narrow bore columns, these materials are quite suitable for CEC, at least in capillary columns of 100 μm I.D.