Pirkle-type chiral stationary phases for ultra-high performance ultra-fast enantioseparations

During the last decade, column manufacturers have put much effort into the design and preparation of materials (e.g., sub-2 micron fully porous and core-shell particles) suitable for highly efficient and fast separations in ultra high-performance liquid chromatography (UHPLC). It is a matter of fact that this advancement has so far only partially touched the field of chiral liquid chromatography. This delay has been essentially due to the lack of understanding of mass transfer processes in chiral chromatography, on the one hand, and to practical difficulties in the preparation of small chiral particles. Recently, Pirkle-type chiral stationary phases (CSPs) have been prepared by using both sub-2 micron fully porous and 2.6 micron core-shell silica particles as base materials. This report describes the employment of these CSPs to achieve not only very high performance but also ultrafast (less than one second) chiral separations in different chromatographic modes.