Application of HPLC Combined with UPLC–Orbitrap–MS in Chemical Characterization, Quantitative Detection, and Species Authentication of Four Panax-derived Products

Panax species are medicinal plants of high pharmaceutical and economic value. However, the high degree of similarity in their chemical compositions often leads to issues of adulteration and challenges in quality control. This study developed an integrated analytical strategy combining high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography–Orbitrap mass spectrometry (UPLC–Orbitrap–MS) to systematically characterize and differentiate four major Panax species: Panax ginseng (RS), Panax quinquefolius (XYS), Panax notoginseng (SQ), and Panax japonicus (BSQ). The established HPLC method proved robust and reliable, enabling the simultaneous quantification of 13 bioactive compounds, including 11 saponins and 2 polyacetylenes, and demonstrated excellent precision, reproducibility, and accuracy. The approach clearly revealed content variations of major constituents among the different species. Chemical fingerprinting combined with similarity analysis indicated significant interspecies differences. A total of 129 compounds were identified using high-resolution mass spectrometry, covering structure types such as protopanaxadiol-type, protopanaxatriol-type, oleanane-type, ocotillol-type, and C-17 side-chain variant saponins. By elucidating the characteristic fragmentation patterns of representative ginsenosides, this work offered a theoretical foundation for reliable compound identification. The results provided a scientific foundation for quality assessment and species authentication, offering a comprehensive strategy for the standardization of Panax-derived medicinal products.