Origin identification of Ginkgo biloba leaves based on laser-induced breakdown spectroscopy (LIBS)

Abstract As a traditional Chinese medicine, Ginkgo biloba leaves have been used in treatments on several diseases for many centuries. The constituents of Ginkgo biloba leaves such as flavonol glycosides and terpene trilactones are active substances associated with the treatment effect. There is not subspecies of Ginkgo biloba so that the constituents of the leaves are mainly related to the geographical origins. In order to trace the geographical origins of Ginkgo biloba, the LIBS technology can be used to measure the spectra of the Ginkgo biloba leaves. However, the spectra of Ginkgo biloba leaves from different origins are very similar so that it is hard to identify them. In this work, three multivariate statistical methods, PCA, LDA and SVM were used to analyze the spectra. The Ginkgo biloba leaves were collected from 8 different locations in Xi'an City, China. The spectra were pre-treated by PCA firstly. Then, the LDA and SVM were adopted to process the data furthermore. When the first 30 principal components (PCs) determined by PCA were used as new input variables, a very good recognition effect was gotten by both LDA and SVM models. The accuracies of origin identification can be up to 97.50% and 96.25% for LDA and SVM, respectively. The result demonstrates that LIBS technology can be used to trace the geographical origins of Ginkgo biloba accurately with the help of multivariate statistical methods.