Enantioseparation of chiral acids and bases on a clindamycin phosphate-modified zirconia monolith by capillary electrochromatography

Porous zirconia monolith modified with clindamycin phosphate (CLIP-ZM) was used as chiral stationary phase (CSP) to separate a set of six acidic and basic chiral compounds in capillary electrochromatography (CEC). Resolutions and chiral selectivity factors of the chiral compounds were measured in ACN/MeOH mobile phases of varying compositions of MeOH and ammonium acetate as the electrolyte. In contrast to the CE separations where only chiral separations of acidic compounds were achieved enantiomers of both acidic and basic compounds were separated with acidic compounds better resolved than basic ones by CEC on the CLIP-ZM CSP. Best chiral separations of the chiral compounds were obtained with an eluent containing 10 mM ammonium acetate and 35 vol.% methanol. (C) 2012 Elsevier B.V. All rights reserved.