Identification of geographical origins of raw American ginseng and tablets based on stable isotope ratios.

American ginseng (Panax quinquefolius) is a medicine food homology plant, whose origin determines the medicinal and economical values. Therefore, a reliable method for the determination of its geographical origin must be established. An accurate, common and stable method to identify geographical origins of raw American ginseng and tablets was established by isotope ratio mass spectrometry (IRMS). 53 samples from 5 origins were collected and analyzed for isotope ratios of the elements C, H, O and N. The result showed that δ(2)H, δ(18)O and δ(15)N values were different among each geographical origin. The δ(2)H, δ(18)O and δ(15)N values were also used to establish discrimination model of geographical origin. According to verification test, the discrimination model of geographical origin was accurate and stable. The δ(2)H, δ(18)O and δ15N values were also found no significant difference between raw American ginseng and its tablet, so the discrimination model of geographical origin could also be used to discriminate the geographical origin of American ginseng tablet. In conclusion, the δ(2) H, δ(18) O and δ(15) N values can be used to discriminate the geographical origin of raw American ginseng and its tablet.