[Study on the identification of standard and false Gancao by Fourier transform infrared spectroscopy]

Standard Gancao (Glycyrrhiza uralensis Fisch) and false Ciguogancao (Glycyrrhiza pallidiflata Batal) were identified fast, nondestructively by Fourier transform infrared spectroscopy (FTIR) combined with derivative spectra and two-dimensional correlation spectroscopy (2D) in the present article. The result shows that although the two kinds of Gancao belong to one genus, there are some certain differences in their chemical components that are reflected in the IR spectra, but with some similarity and dissimilarity in the IR spectra. The two kinds of Gancao are quite different from each other in second derivative spectra and 2D spectra. Based on the differences reflected in the IR and 2D IR, the standard gancao can be identified from the false easily and clearly. The result also proved that there is a relationship between the IR spectra and the chemical components of the herbs. This method is fast, accurate and nondestructive, and the wastage of sample is less. The fast, accurate property of 2D spectroscopy makes it a powerful and new approach to evaluating medicinal herbs impersonally.