LIQUID-CHROMATOGRAPHIC ELECTROSPRAY MASS-SPECTROMETRIC ANALYSIS OF COPTIDIS RHIZOMA

Seven protoberberine alkaloids from Coptidis Rhizoma were separated on a Cosmosil 5C18-MS column (5 mu m, 250x4.6 mm I.D.) using ammonium ac etate buffer (isocratic) or ammonium acetate-sodium dodecyl sulfate bu ffer (gradient) with UV and electrospray ionization mass spectrometric (ESI-MS) detection. Selected-ion monitoring was used to resolve the c ompounds in an overlapped peak and collision-induced dissociation reac tion was used to obtain structural infomation of individual components . By use of this LC-UV-ESI-MS method, these protoberberine alkaloids ( berberine, palmatine, coptisine, epiberberine, jatrorrhizine, columbam ine and berberastine) in a crude extract of Coptidis Rhizoma can be ea sily separated and identified within 50 min.