Separation of β-receptor blockers and analogs by Capillary Liquid Chromatography (CLC) and Pressurized Capillary Electrochromatography (pCEC) using a vancomycin chiral stationary phase column

Enantiomeric separation of chiral pharmaceuticals was carried out by means of in capillary liquid chromatography (CLC) and pressurized capillary electrochromatography (pCEC) using a vancomycin chiral stationary phase (CSP). A 100 μm I.D. fused-silica capillary was packed with 5 μm diameter silica particles modified with vancomycin. Enantiomeric resolution of fifteen β-receptor blockers and analogs was studied by polar organic CLC mode and reversed-phase pCEC mode using mobile phases containing methanol-isopropanol-acetic acid-triethylamine and TEAA buffer-methanol, respectively. Several factors affecting chiral separation were investigated in both CLC and pCEC mode. Good enantiomeric resolution was achieved by CLC mode for propranolol, celiprolol, esmolol, bisoprolol, atenolol, metoprolol and carteolol using methanol-isopropanol-acetic acid-triethylamine (70 : 30 : 0.05 : 0.05, v/v/v/v) as mobile phase and for clenbuterol, bambuterol, terbutaline, and salbutamol using methanol-isopropanol-acetic acid-triethylamine (50 : 50 : 0.05 : 005 or 50 : 50: 0.025 : 0.05, v/v/v/v) as mobile phase. The baseline was achieved by pCEC mode for the separation of esmolol, bisoprolol, atenolol, metoprolol, carteolol in the mobile phase containing MeOH-0.05%TEAA (pH 7.0) (90 : 10, v/v) (–10 kV), and that of propranolol and celiprolol in the mobile phase containing MeOH-0.025%TEAA (pH 7.0) (90 : 10, v/v)(–10 kV). Comparative enantioseparations performed in polar organic CLC and reversed phase pCEC mode revealed significant difference.