摘要
The methods of fuzzy cluster and curve-fitting combined with FTIR were used to determine the origins of Herba Abri cantoniensis and Herba Abri mollis. The spectra of Herba Abri cantoniensis and Herba Abri mollis are similar, both with typi-cal spectral shapes. The two spectra can be divided into 3 parts: the 1st is 3 500-2 800 cm~(-1) , containing stretching hands of -OH, N-H, and CH_2; the 2nd is 1 800-800 cm~(-1), containing stretching hands of ester carbonyl group and indican C-O(H), vibrational bands of C-C and benzene ring; The 3rd is 800-400 cm~(-1), containing skeletal vibration and scissoring vibration of molecular. The recorded FTIR spectral data were processed by 9-point-smoothing, 1st derivative, SNV and fuzzy cluster analy-sis sequentially. The fuzzy cluster analysis was carried out by similarity or dissimilarity matrix, and two matrices are computed with Manhattan and Euclidean distance. The results indicated that the optimization used Manhattan and dissimilarity matrix, and 5 origins of Herba Abri cantoniensis were perfectly discriminated, but 2 origins of Herba Abri mollis were mixed and identified from the other 3 origins. So the characterized bands at 1 034 cm~(-1) of the average 1-D spectra of Herba Abri cantoniensis and Herba Abri mollis were fitted combining 2nd derivative for further distinguishing their spectral characteristic. The results of curve-fitting showed that the bands of wild HerbaAbri cantoniensis and the other origin ones were decomposed to 11 and 9 com-ponent bands respectively, but the bands of Shanglin and the other origins Herba Abri mollis were decomposed to 9 and 8 com-ponent bands dissimilarly, and the locations and normalized densities of these component hands were different. From this, to-gether with the results of fuzzy cluster analysis, it is concluded that the combination of two methods may identify the origins of Herba Abri cantoniensis and Herba Abri mollis availably.
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单位广西科学院