A micellar electrokinetic capillary chromatography (MECC) method for the se
paration of three active components, imperatorin (IM), isoimperatorin (IO)
and scopoletin (SC), in Angelica dahurica Benth and its preparation was dev
eloped. The optimum separation fur these analytes was achieved using 10 mM
berate, 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)
x 75 mum I.D. fused-silica capillary. The linear calibration range was 12.0
-800.0 mug ml(-1) for IM, 10.0-850.0 mug ml(-1) for IO and 3.5-600.0 mug 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 metho
d established in this paper. (C) 2001 Elsevier Science B.V. All rights rese