Possible resolution gain in enantioseparations afforded by core-shell particle technology.
Whether columns packed with core-shell particles may outperform those packed with fully porous particles for chiral separations is controversial. The potential advantages of such columns are investigated from a theoretical viewpoint. The height equivalent to a theoretical plate (HETP) associated to the slow adsorption-desorption process typical of chiral chromatography was derived from the Laplace transform of the general rate model of chromatography for core-shell particles. The relationship between the resolution factor and the core-to-particle diameter ratio is predicted at constant selectivity. The calculations are based on a complete set of actual kinetic parameters (longitudinal diffusion, eddy dispersion, intra-particle diffusivity, and adsorption-desorption constant) measured for a reference column packed with Lux Cellulose-1 fully porous particles. If we compare columns packed with the best procedure available in either case, the results demonstrate that those packed with core-shell particles may outperform to a degree those packed with fully porous particles. The minimum reduced HETP could decrease from 2.0 to 1.7. The maximum relative gain in resolution is about 10%, which is not negligible for critical enantioselective-separations. This gain is observed only if the packing uniformity of the core-shell particles is achieved.
Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600, USA.
Fabrice
F
Gritti
Department of Chemistry, University of Tennessee, Knoxville, TN 37996-1600, USA. Electronic address: guiochon@utk.edu.
Georges
G
Guiochon
D000327:Adsorption; D002482:Cellulose / Q000737:chemistry; D002853:Chromatography, Liquid / Q000295:instrumentation* / Q000592:standards*; D004058:Diffusion; D008962:Models, Theoretical; D010316:Particle Size; D016062:Porosity
D002482:Cellulose
Chiral chromatography; Core–shell particles; Mass transfer mechanism; Resolution factor; Slow adsorption–desorption kinetics