Two Multidimensional Chromatography/High-Resolution Mass Spectrometry Approaches Enabling the In-Depth Metabolite Characterization Simultaneously from Three <i>Glycyrrhiza</i> Species: Method Development, Comparison, and Integration
Meiyu Liu, Yuying Zhao, Xiaohang Li, Xiaohang Li, Tingting Zhang, Xiaoyan Xu, Meiting Jiang, Xiaoxuan Tian, Peng Zhang, Hong‐Hua Wu, Xiumei Gao, Xue Li, Xue Li, Hongda Wang, Wenzhi Yang
Abstract
Two offline multidimensional chromatography/high-resolution mass spectrometry systems (method 1: fractionation and online two-dimensional liquid chromatography, 2D-LC; method 2: fractionation and offline 2D-LC) were established to characterize the metabolites simultaneously from three Glycyrrhiza species. Ion exchange chromatography in the first-dimensional ( 1 D) separation was well fractionated between the acidic (mainly triterpenoids) and weakly acidic components (flavonoids). These obtained subsamples got sophisticated separation by the second ( 2 D) and third dimension ( 3 D) of chromatography either by online reversed-phase chromatography × reversed-phase chromatography (RPC × RPC) or offline hydrophilic interaction chromatography × RPC (HILIC × RPC). Orthogonality for the 2 D/ 3 D separations reached 0.73 for method 1 and 0.81 for method 2, respectively. We could characterize 1097 compounds from three Glycyrrhiza species based on an in-house library and 33 reference standards, involving 618 by method 1 and 668 by method 2, respectively. They exhibited a differentiated performance and complementarity in identifying the multiple subclasses of Glycyrrhiza components.