Detection of Ilicis rotundae Cortex Decoction Pieces Using Raman Spectroscopy Fingerprints

Abstract

Ilicis rotundae Cortex (IRC, also called Jiubiying) is a traditional Chinese medicine, factors such as the origin and growing environments will affect its quality and content of active ingredients. Therefore, it is necessary to realize rapid detection to better implement quality control. Raman spectroscopy has been commonly used to identify molecules and analyse biological compounds in Fingerprints. In this study, four commercial samples from different origins were collected, Raman spectra of four samples were established by confocal Raman microscopy at 785 nm, and the positions and attribution of spectral peaks were determined. The similarity of spectra were analyzed by MATLAB software, and the first and second derivative were transformed to establish the characteristic fingerprints. In the results, all the samples showed common characteristic peaks near 448, 481, 565, 868, 944 and 1088 cm−1, showing the spectral characteristics of carbohydrates and glycosidic bonds. The correlation coefficient of the characteristic peaks of the samples were between 0.9745 and 0.9951, and the consistency coefficient were between 0.9782 and 0.9944. The peak shapes of the first derivative of spectrum were significantly different among the range of 180–340, 460–540, 700–860 and 1010–1100 cm−1, and the peak shapes of the second derivative of spectrum were significantly different among the range of 180–340, 500–540 and 760–860 cm−1. In conclusion, the first and second derivative of Raman spectra for samples from four different sources were significantly different, indicating the Raman fingerprint was successfully established, which can be used as a basis for rapid identification of IRC decoction pieces which lays a foundation for the further identification of decoction pieces from different origins.