Rapid Authentication of Dendrobium officinale by Near-Infrared Reflectance Spectroscopy and Chemometrics

Abstract

Near-infrared spectroscopy coupled to chemometrics was used to develop a method to discriminate D. officinale, a high value herbal medicine, from non-D. officinale. Thirty-eight samples were analyzed with high performance liquid chromatography (HPLC) as a reference method. The near-infrared spectra were collected in reflectance mode. Spectral data were then processed by pretreatment methods and two chemometric classification techniques, principal component analysis (PCA) and hierarchical cluster analysis (HCA). Principal component analysis of near-infrared spectra and HPLC data revealed significant variation in D. officinale from other Dendrobium species. Moreover, a dendrogram based on hierarchical cluster analysis of the first derivative near-infrared spectra showed a chemical relationship among the samples. These results also approximately confirmed the results obtained by principal component analysis. In general, the results show that coupling of near-infrared spectroscopy to chemometric techniques is a valuable tool for rapid, inexpensive, and non-invasive authentication of D. officinale.

Keywords:

• Dendrobium officinale
• Hierarchical cluster analysis (HCA)
• High performance liquid chromatography (HPLC)
• Near-infrared (NIR) spectroscopy
• Principal component analysis (PCA)