Identification and determination of active components in Angelica dahurica Benth and its medicinal preparation by capillary electrophoresis

A micellar electrokinetic capillary chromatography (MECC) method for the separation of three active components, imperatorin (IM), isoimperatorin (IO) and scopoletin (SC), in Angelica dahurica Benth and its preparation was developed. The optimum separation for these analytes was achieved using 10 mM borate, 20 mM SDS and 10%(v/v) acetonitrile, with applied voltage of 22 kV. All experiments were performed using a 50.0 cm (42.5 cm effective length)×75 μm I.D. fused-silica capillary. The linear calibration range was 12.0–800.0 μg ml−1 for IM, 10.0–850.0 μg ml−1 for IO and 3.5–600.0 μg ml−1 for SC. The recoveries of three constituents were from 91.3 to 108.7%. Also, the dissociation constant (pKa) of SC was determined by the CE method established in this paper.