Origin traceability of Cordyceps sinensis based on trace elements and stable isotope fingerprints

Cordyceps sinensis is a kind of valuable Chinese herbal medicine, and its quality and price depend on the place of origin. Building a traceability system for Cordyceps sinensis products is an effective way to protect Cordyceps sinensis geographical indication products and consumers. In this study, concentrations of 45 trace elements and stable C, N, and Pb isotopes were used to distinguish Cordyceps sinensis samples from different habitats and different varieties (natural and artificial). The results showed that there were significant differences in the isotope compositions of N and Pb and trace elements contents in the Cordyceps sinensis samples from different sources. Stepwise discriminant analysis was used to select effective traceability indicators, and three discriminant models were successfully established. A combination of Co, Sr, Cu, Tl, and Zr indexes was selected to distinguish the naturally grown samples from the artificially cultivated ones, with an overall cross-validation correctness rate of 90.0 %; while a combination of As, Cu, Rb, Tl, W, and Zr indexes was adopted to distinguish the naturally grown samples from different regions, with a corresponding 100.0 % overall cross-validation correctness rate. To simultaneously distinguish samples between natural and artificial and between different regions, a combination of As, Cu, Rb, Tl, U, W, and delta 15N indexes was employed, with an overall cross-validation correctness rate of 89.3 %.