A sensitive and specific liquid chromatography mass spectrometry method for simultaneous determination of berberine, palmatine, coptisine, epiberberine and jatrorrhizine from Coptidis Rhizoma in rat plasma. - Yu,S.; Pang,X.Y.; Deng,Y.X.; Liu,L.; Liang,Y.; Liu,X.D.; Xie,L.; Wang,G.J.; Wang,X.T. (Int J Mass Spectrom, 2007)