title: Enantioresolution of basic pharmaceuticals using cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral stationary phase and polar organic mobile phases.
abstract: A polysaccharide-based chiral stationary phase (Sepapak-4), with cellulose tris(4-chloro-3-methylphenylcarbamate) as chiral selector, has been investigated in liquid chromatography (LC). Its enantioresolution power was evaluated towards 13 basic amino-drugs with widely different structures and polarities, using polar organic mobile phases. After preliminary experiments, acetonitrile was selected as the main mobile phase component, to which a low concentration of diethylamine (0.1%) was systematically added in order to obtain efficient and symmetrical peaks. Different organic solvents were first added in small proportions (5-10%) to acetonitrile to modulate analyte retention. Polar organic modifiers were found to decrease retention and enantioresolution while hexane had the opposite effect, indicating normal-phase behaviour under these conditions. The addition of an organic acid (formic, acetic or trifluoroacetic acid) was found to strongly influence the retention of the basic amino drugs in these nonaqueous systems. The nature and proportion of the acidic additive in the mobile phase had also deep impact on enantioresolution. Therefore, the studied compounds could be subdivided in three groups in respect to the acidic additive used. All analytes could be enantioseparated in relatively short analysis times (10-20 min) using these LC conditions.
authors: Department of Analytical Pharmaceutical Chemistry, Institute of Pharmacy, University of Liège, CHU, B 36, B-4000 Liège 1, Belgium.
authors: Katina S S
authors: KS
authors: Dossou
authors: Patrice
authors: P
authors: Chiap
authors: Bezhan
authors: B
authors: Chankvetadze
authors: Anne-Catherine
authors: AC
authors: Servais
authors: Marianne
authors: M
authors: Fillet
authors: Jacques
authors: J
authors: Crommen
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002482:Cellulose / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D004048:Diethylamines / Q000737:chemistry; D005561:Formates / Q000737:chemistry; D015394:Molecular Structure; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D014269:Trifluoroacetic Acid / Q000737:chemistry
chemical_list: D004048:Diethylamines; D005561:Formates; D012997:Solvents; C030544:formic acid; D002482:Cellulose; C034281:diethylamine; D014269:Trifluoroacetic Acid; D019342:Acetic Acid