Rapid Analysis of Fructus forsythiae by Near-infrared Spectroscopy

Abstract

In this paper, Near-infrared spectroscopy (NIRS) was introduced into the field of Chinese herbal medicines and a rapid analytical method which can not only differentiate the two species of Fructus forsythiae, QingQiao (QQ) and LaoQiao (LQ), but also determine the contents of Phillyrin, Forsythoside A and Moisture in Fructus forsythia was established. The total content of volatile oil in Fructus forsythia was used as an important parameter for discrimination of QQ and LQ. Two lignans components, Phillyrin and Forsythoside A were analyzed successively by high-performance liquid chromatography (HPLC). Scattering effect and baseline shift in the NIR spectra were corrected by several pre-processing methods. By using discriminant analysis, a model which can be used to identify the species of Fructus forsythiae was established and samples were separated successfully into two different clusters corresponding to QQ and LQ. Finally, partial least squares (PLS) regression was used to build the correlation model. The results showed that the correlation coefficients of the calibration models are R = 0.959 for the Moisture, R = 0.957 for Phillyrin and R = 0.960 for Forsythoside A. The outcome showed that NIRS can provide a simple and accurate way in the quality control of Chinese herbal medicine (CHM).