Study on the Identification ofRadix Bupleurifrom Its Unofficial Varieties Based on Discrete Wavelet Transformation Feature Extraction of ATR-FTIR Spectroscopy Combined with Probability Neural Network

The attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) was employed to acquire the infrared spectra ofRadix Bupleuriand its unofficial varieties: the root ofBupleurum smithiiWolff and the root ofBupleurum bicauleHelm. The infrared spectra and spectra of Fourier self-deconvolution (FSD), discrete wavelet transform (DWT), and probability neural network (PNN) of these species were analyzed. By the method of FSD, there were conspicuous differences of the infrared absorption peak intensity of different types betweenRadix Bupleuriand its unofficial varieties. But it is hard to tell the differences between the root ofBupleurum smithiiWolff and the root ofBupleurum bicaule. The differences could be shown more clearly when the DWT was used. The research result shows that by the DWT technology it is easier to identifyRadix Bupleurifrom its unofficial varieties the root ofBupleurum smithiiWolff and the root ofBupleurum bicaule.