Rapid Differentiation of Asian and American Ginseng by Differential Ion Mobility Spectrometry-Tandem Mass Spectrometry Using Stepwise Modulation of Gas Modifier Concentration

• Published in: Journal of the American Society for Mass Spectrometry Vol. 30; no. 11; p. 2212
• Main Authors: Wu, Ri, Chen, Xiangfeng, Wu, Wei-Jing, Wang, Ze, Wong, Y-L Elaine, Hung, Y-L Winnie, Wong, H-T, Yang, Minli, Zhang, Feng, Chan, T-W Dominic
• Format: Journal Article
• Language: English
• Published: United States 01.11.2019
• Subjects: Tandem mass spectrometry; Collision-induced dissociation; Differential ion mobility spectrometry; Isomeric ginsenosides

This study reports a rapid and robust method for the differentiation of Asian and American ginseng samples based on differential ion mobility spectrometry-tandem mass spectrometry (DMS-MS/MS). Groups of bioactive ginsenoside/pseudo-ginsenoside isomers, including Rf/Rg /F , Rb /Rb /Rc, and Rd/Re, in the ginseng extracts were sequentially separated using DMS with stepwise changes in the gas modifier concentration prior to MS analysis. The identities of the spatially separated ginsenoside/pseudo-ginsenoside isomers were confirmed by their characteristic compensation voltages at specific modifier loading and MS/MS product ions. As expected, Asian ginseng samples contained some Rf and an insignificant amount of F , whereas American ginseng samples had a high level of F but no Rf. The origin of the whole and sliced ginseng could further be confirmed using the quantitative ratios of three sets of ginsenoside markers, namely, Rg /Re, Rb /Rg , and Rb /Rc. Based on our results, new benchmark ratios of Rg /Re < 0.15, Rb /Rg  > 2.15, and Rb /Rc < 0.26 were proposed for American ginseng (as opposed to Asian ginseng).