## 1 Introduction  
Ginseng herbs, the roots and rhizomes of the _Panax_ species (_Araliaceae_), are valuable traditional herbs that have a thousand years of medical history and are well-known worldwide as herbal medicines and food to enhance body strength, prevent exhaustion, and improve immunity [1]. _Panax_ species are the important medicinal resources in the world because of their significant medicinal value, and are distributed in more than 35 countries, particularly America, South Korea, Japan, and China. With their popularity all over the world, the attention that _Panax_ has received has increased significantly [2; 3; 4; 5]. These herbs contain complex chemical constituents. Ginensoides are the characteristic and principal components and have been used as an important index in quality assessment and control. The skeleton of aglycones reveals dammarane tetracyclic triterpenapoidal saponins and oleanane pentacyclic triterpenapoidal saponins (oleanolic acid-type ginensosides, OAs) in natural ginensides. Furthermore, dammarane tetracyclic triterpenapoidal saponins can be divided into protopanaxatiol-type ginsengosides (PPTs) and protopanaxadiol-type ginsengosides (PPDs) according to the study of dammarane structures [6]. Although numerous analytical approaches have been applied for the qualitative and quantitative analysis of ginseng, including UV, IR, TLC, HPLC, and UPLC, the analysis of ginseng is still a great challenge because of the diversity, similarity, and complexity of their chemical structures [1]. In recent years, some advanced analytical techniques have been rapidly developed for the quality assessment and control of traditional herbs. Q-Exactive Orbitrap High-Resolution Mass Spectrometry (Q-Exactive/HRMS) is a recently developed technique with extremely high resolution, sensitivity, and mass accuracy. It exhibits a stronger power for the scanning and identification of complex compounds than normal mass spectrometry [7]. LC-HRMS is now a well-established technique for the qualitative analysis of chemical compounds in metabolomic studies, and has seen significant progress in recent years [1]. Combining UHPLC with Q-Exactive/HRMS has been increasingly used to screen and identify complex compounds in herbs and food products [8; 9]. Furthermore, high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) is also a powerful tool for complex composition analysis for the quantitation and screening of specific chemicals in foods and plants [10; 11; 12; 13]. The MS detector can provide information on molecular formula and fragmentation ions. Moreover, the multiple reaction monitoring (MRM) mode is highly specific and sensitive; it is useful for quantifying complex compounds in natural products [14]. Previous studies show that more than 10 species of the genus _Panax_ are available around the world. Among them, _Panax ginseng_, _Panax quinquefulus_, and _Panax notoginseng_ are the most recognized species and have been subjected to extensive study [15; 16]. The other Panax species are less known. _Panax japonicus_ (PJ), _Panax japonicus_ var. major (PM), and _Panax zingiberensis_ (PZ) are three different ginseng herbs with similar bioactivities; they grow in the mid- and low-latitude areas in the Northern hemisphere [17; 18]. Similar to other Panax species, they contain a high amount of various chemical constituents, such as saponins, polysaccharides, amino acids and microelements, which are believed to contribute to their multiple bioactivities and restorative functions. PJ is widely used as a traditional medicine in China and Japan and has been recorded in the Chinese Pharmacopoeia and the Japanese Pharmacopoeia [17; 19; 20]. PM, which is thought to be a variety of PJ, has also been recorded in the Chinese Pharmacopoeia [18]. PZ is widely used for strengthening the immune response and providing cardiovascular protection in folk medicines of China and Myanmar [21].