C/N/H/O stable isotope analysis for determining the geographical origin of American ginseng (Panax quinquefolius)

Abstract

A total of 44 root samples of American ginseng (Panax quinquefolius) originating from five different geographical areas (America = 6, Canada = 10, Beijing = 8, Jilin = 8, and Shandong = 12) were collected from specialty wholesalers in China. The C/N/H/O stable isotope ratios were determined using an elemental analyzer coupled with a stable isotope ratio mass spectrometer. Our results revealed that a single variable was unable to clearly discriminate between the various geographical origins of American ginseng, whereas the combination of δ18O and δ15N and the combination of δ13C, δ15N, and δ18O provided useful information for the identification of American ginseng from the five regions. Moreover, the application of different multivariate statistical approaches, including the one-way analysis of variance and linear discriminant analysis (LDA), to further explore the ability of C/N/H/O stable isotopes for determining the geographical origins of American ginseng identified a significant difference (P < 0.05) in the stable isotope ratios from different regions, and high recognition (90.9 %) and satisfactory predictive ability (86.4 %) were achieved with the LDA. The present findings suggest that the C/N/H/O stable isotopes can be potentially applied in the authentication of different geographical origins of American ginseng.