[Study on IR fingerprint spectra of Alpinia oxyphylla Miq]

Fourier transform infrared spectrum has been developed for application in the quality control of traditional Chinese medicine, and two new indexes, including common peak ratio and variant peak ratio, were applied, and their values were calculated by means of the sequential analysis for eight kinds of essence oil of Alpinia oxyphylla Miq from different cultural areas (Hainan, Guangxi and Guangdong), in which each sample's IR fingerprint spectra were set up and the common peak ratio and variant peak ratio sequences were arranged in the order of size in comparison with other samples. It can be seen that Alpinia oxyphylla samples from Guangxi, Hainan and Guangdong provinces could be successfully revealed directly by the common peak ratio and variant peak ratio sequences. In comparison with their conventional IR spectra, the primary difference in Alpinia oxyphylla is the intensity of characteristic peaks at 1 710 and 1 666 cm(-1). Considering the spectral range of 400-4 000 cm(-1), the common peak ratio of the spectra between Hainan and Guangdong was 62%, while the common peak ratio between Hainan and Guangxi was 52%. But the mix common peak ratio of the spectra in Hainan is 66%. The fingerprint characters of IR can not only identify the main chemical constituents in medicinal materials, but also compare the components differences among the similar samples. The analytical method is an rapid, effective, fast and advanced to evaluate the production area for pharmaceutical market.