Differentiation and authentication of Panax ginseng, Panax quinquefolius, and ginseng products by using HPLC/MS

An LC/MS-based method is established for the differentiation and authentica tion of specimens and commercial samples of Panax ginseng (Oriental ginseng ) and Panax quinquefolius (American ginseng). This method is based on the s eparation of ginsenosides present in the ginseng methanolic extracts using high-performance liquid chromatography (HPLC), followed by detection with e lectrospray mass spectrometry. Differentiation of ginsenosides is achieved through simultaneous detection of intact ginsenoside molecular ions and the ions of their characteristic thermal degradation products. An important pa rameter used for differentiating P. ginseng and P. quinquefolius is the pre sence of ginsenoside Rf and 24(R)-pseudoginsenoside F-11 in the RICs of Ori ental and American ginsengs, respectively. It is important to stress that g insenoside Rf and 24(R)-pseudoginsenoside F-11, which possess the same mole cular weight and were found to have similar retention times under most LC c onditions, can be unambiguously distinguished in the present HPLC/ MS metho d. The method developed is robust, reliable, reproducible, and highly sensi tive down to the nanogram level.