Geographical origin discriminant of Panax japonicus based on stable isotope ratios analysis / 中草药

Objective: The isotopic ratios of light elements (C/N/H/O) in Panax japonicus from six producing areas were determined with isotope ratio mass spectrometry.Methods: Three methods, including linear discrimination (LD), gaussian kernel support vector machine (SVM), and the back-propagation learning algorithm of pattern recognition based on neural network toolbox (BPN) were employed to establish a model for P. japonicus geographical origin discrimination. Results: The results showed that stable isotope carbon (δ 13C) had obvious regional characteristics, which will be used to effectively distinguish the origin of P. japonicus. The methods of LD and BPN could classify the geographical origin of P. japonicus from six producing areas, both of which showed that the accuracy rates were 100% using training dataset. Conclusion: Therefore, the stable isotope technique combined with LD and BPN method can effectively trace the origin of P. japonicus.

Geographical origin discriminant of Polygoni Multiflori Radix based on stable isotope ratios and elemental analysis / 中国中药杂志

The seventy samples of Polygoni Multiflori Radix were collected from three producing areas: Bozhou, Anhui province, Jingmen, Hubei province and Xichang, Sichuan province. Three stable isotope ratios and contents of 44 elements in the Polygoni Multiflori Radix samples were determined by EA-IR-MS and HR-ICP-MS. Three data mining methods，including partial least square discriminant analysis (PLS-DA), fisher linear discriminant analysis (FLDA) and decision tree CHAID were employed to establish a model for geographical origin discrimination．The study results showed that the stable isotope ratios expressed significant difference followed with the different producing areas, and will be used to discern the samples from different producing areas, effectively. Combined with the data of elemental analysis, the accuracy rates of model can be further improved. All the three methods showed the accuracy rates of external sample were over 90% using training dataset. These results confirmed that stable isotope ratios and multi-elemental analysis combined with chemometric method was effectiv in geographical tracing of Polygoni Multiflori Radix．The analysis method has great potential and prospect in geographical origin discriminant of Chinese medicinal materials, and provids a new study method to identify origin information of Chinese medicinal materials.

Geographical origin discriminant of Dendrobium officinale based on stable isotope ratios / 中国中药杂志

The isotopic ratios of strontium isotope (Sr) and light elements (C/H/O/N) in Dendrobium officinale from different producing areas (Shaoguan, Guangdong; Yulin, Guangxi; Shibing, Guizhou; Wenshan, Yunnan and Zhejiang province) were determined with thermal ionization mass spectrometry (TI-MS) and isotope ratio mass spectrometry (IRMS)．The differences of the stable isotope ratios in D. officinale were obtained by the variance analysis and the correlation analysis, and pattern recognition techniques with principal component analysis (PCA) was used to classify the geographical origins of D. officinale from different producing areas．The isotopic ratios of strontium isotope can be used to identified D. officinale in Zhejiang province, and the isotopic ratios of light elements showed the difference followed with the different producing areas. For δD and δ¹⁸ O in samples, maybe influenced by the environment effect. A positive correlation was found between δD and δ ¹⁸O.The principal component analysis was used to discern the samples of D. officinale from different producing areas based on detection technology of stable isotope ratios.These results revealed that it was possible and feasible to classify the geographical origin of D. officinale by the method of determination of isotopes,and provided a new method to identificate origin information of Chinese medicinal materials.