Comparative study on the infrared fingerprint of nitraria tangutorum bobr.based on the methods of sequential analysis of dual-indexes and cluster analysis

The method of sequential analysis of dual-indexes and cluster analysis were utilized to investigate the infrared fingerprints of 7 plant species of the genus Nitraria L.Using common peak ratio index and variant peak ratio index,based on IR fingerprint of Nitraria L.from different regions,common peak ratio and variant peak ratio of 7 samples were calculated respectively to set up a new method called dual-index sequence analysis for distinguishing samples from different regions.The result showed that the compositions of G3 and G6 were the most similar,and the similarity was 57.89,in different plant samples. The similarity between G3 and G5 was 52.63,the similarity among G1,G7 and other samples were the lowest.On the whole,FTIR combined with cluster analysis or sequential analysis of dual-indexes provided an effective way to identify the regions of Nitraria tangutorum Bobr.rapidly and simply,For the difference between different regions of different varieties of white provided a practical and reliable method.