Discrimination of Fructus forsythiae According to Geographical Origin with Near-infared Spectroscopy

Abstract

In this paper, near-infrared spectroscopy (NIRS) combined with discriminant analysis was used as a qualitative tool to distinguish Fructus forsythiae from different geographical origins by collecting and analysing the NIR spectra in the range of 12000-4000cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> . NIR spectra were analyzed by two methods: clustering analysis and discriminant analysis. In the former, the second derivative and Norris smoothing were utilized together to correct the scattering effect and eliminate the baseline shift in the range 4092--8008 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> in order to achieve a reliable classification on Fructus forsythiae from different geographical origins. The latter method was used to establish a discriminant analysis model which can be used to identify the geographical origin of Fructus forsythiae. The result shows that the correct rate of the internal cross-validation identification is 96.99%. By the model, 12 samples were analyzed, and the prognostications of their geographical origins are exact on the whole. It's indicated that NIR along with the chemo metrics methods provides a simple and accurate way in rapid dertimination of herbal medicines from different geographical origins.