API-ionspray Tandem Mass Spectrometric Analysis of Protopine and Oxyberberine Alkaloids

API-ionspray MS and MS/MS techniques were utilized to characterize the structures of seven alkaloids, consisting of six protopine and oxyberberine alkaloids, which were isolated, identified, and derivatized previously from the roots of a variety of Thalictrum sp. (Ranunculaceae) and Coptis sp. (Ranunculaceae), based on the TLC, UV, IR, NMR and El- & CI-MS data. In this study, apparent protonated molecular (MH + ), MNa + , dimeric MH + and dimeric MNa + ions for the tertiary alkaloids, and molecular ion (M + ) for the quaternary alkaloids in the Q1 Scan MS spectra, and the product ions in the MS/MS spectra of MH + and M+ were acquired for structural elucidation of the studied alkaloids each in nanogram quantities.