Studies on Fragmentation of Potassium Glycyrrhizates and Sodium Glycyrrhizates by Electrospray Ion Trap Mass Spectrometry

The fragmentation of potassium and sodium glycyrrhizates was studied by electrospray ion trap mass spectrometry(ESI ITMS). The results indicated that all of the mono , di and tri potassium or sodium glycyrrhizates gave abundant quasi molecular ion M+H + in their (+) ESI ITMS spectra. The daughter ions of losing one glucuronate moiety from the quasi molecular ion and the daughter ion of diglucuronate moiety were exhibited in their ESI MS 2 spectra. All above daughter ions in the MS 2 spectra contained the same number of corresponding metal ions with the parent ion. Therefore, the ESI ion trap mass spectrometry is a useful technique to distinguish mono , di and tri potassium or sodium glycyrrhizates. In addition, quasi molecular ions of mono and tri potassium or sodium glycyrrhizates were displayed in the ESI MS spectra of di potassium or di sodium glycyrrhizate. This indicated the intermolecular exchange of the metal ions in water solutions of the glycyrrhizate disalts.