[Application of FTIR spectroscopy to the identification of Glycyrrhiza uralensis Fisch].

Fourier transform infrared spectroscopy with a spectra range of 4 000-400 cm(-1) was used to identify fifty nine samples of wild or cultivated Glycyrrhiza uralensis Fisch. from six different places around China. The 1D spectra and their second derivative spectra of herbal samples, the corresponding extract samples and two marker compounds (glycyrrhizic acid and liquiritin) were compared. The wide peak in 1 100-1 000 cm(-1) was used to identify the components of polysaccharide; the peak at 1 318 cm(-1) mainly belonged to calcium oxalate; the peaks at 1 745 and 1 386 cm(-1) were used to assess the content of glycyrrhizic acid; the peaks at 1 612 and 1 512 cm(-1) were the characteristic peaks of liquiritin. The intensity of characteristic peaks can represent the content of corresponding compound. The horizontal and vertical comparisons of all herbal samples showed that the characteristic peaks of wild samples were strong, and all wild samples had the similar quality; the characteristic peaks of cultivated samples were weaker than those of the wilds; the ages of glycyrrhiza had great effect on the quality of samples.