POSTER: Evaluation of core-shell stationary phases in capillary electrochromatography for their potential to separate chiral pharmaceutical compounds.

Stationary phases with core-shell particles are merely used in high performance liquid chromatography (HPLC). There are many advantages of core-shell materials compared to porous particles, such as a shorter diffusion path-length which results in a lower contribution of the mass transfer (the C-term in the van Deemter equation). Another important advantage is the more uniform particle-size distribution, resulting in a lower longitudinal diffusion (the B-term in the van Deemter equation). These advantages result in higher column efficiencies and faster elution times.
Capillary electrochromatography (CEC) is a hybrid technique of capillary electrophoresis (CE) and HPLC. It combines the selectivity of HPLC and the high separation efficiency of CE, in addition to low sample and solvent consumptions. The goal of this study is to compare separations of pharmaceutical enantiomers in CEC using two types of chiral stationary phases (CSPs); one with totally porous particles and the other with core-shell particles.
In this study we compare results on a porous commercially available CSP with two core-shell CSPs (coated with 5 and 10% (W/W) chiral selector) and in house made alternatives of the porous CSPs.
The setup of this study is to separate 20 chiral pharmaceutical compounds (10 basic, 5 acidic and 5 neutral compounds) on each CSP. To separate the acidic compounds we use a more acidic buffer. In addition, van Deemter curves will be generated by applying different voltages between 3-30kV.
We expect that the 10% (and then the 5%) core-shell CSPs can generate better performances and higher selectivities compared with their porous counterparts without any loss of resolutions or efficiencies.