A novel enantioseparation method for amlodipine by high performance capillary electrophoresis with capacitively coupled contactless conductivity detection(C4D) using binary chiral selectors was developed.The enantiomers of amlodipine were baseline separated in 20 min with an uncoated fused silica capillary(50 μm i.d.×45 cm,leff=40 cm) under the following optimum conditions:18 mmol/L citric acid+6 mmol/L NH3?H2O+12 mg/L hydroxypropyl methyl cellulose(HPMC)+35 mmol/L hydroxypropyl-β-cyclodextrin(HP-β-CD)as background electrolyte,separation voltage:+15 kV,injection voltage:13 kV,injection time:10 s.The calibration curve of the enantiomers showed a good linearity in the range of 2.0-40 mg/L with correlation coefficient more than 0.995.The detection limit of the enantiomers was 0.5 mg/L.Effects of several factors on resolutions,such as composition of running buffer,pH value,separation voltage and injection method,were investigated.The efficacy of the HP-β-CD and HPMC were discussed.The results indicated that the proposed method was simple,low cost,rapid and reproducible,and was successfully applied to monitor the enantiomers of amlodipine in the commercial amlodipine tablets and levoamlodipine tablets. |