应用红外光谱法鉴别肉苁蓉及其混淆品草苁蓉和锁阳

采用傅里叶变换红外光谱法结合二维相关分析技术分别对药用植物肉苁蓉及其混淆品草苁蓉、锁阳进行了鉴别研究.结果表明,三者的红外光谱图表现出了一定的差异性:肉苁蓉在1 730和931 cm-1有吸收峰,草苁蓉在1 510,1 375,1 266 cm-1处存在吸收峰,锁阳的最高峰位于1 614cm-1处.在二阶导数谱图上三者差异更加明显:肉苁蓉在1 453,1 336,931,892 cm-1处都有较强的吸收峰.其中931 cm-1处的吸收峰较尖锐,强度也最强;草从蓉的最强峰位于1 509 cm-1,并且1 633和1 161 cm-1处的吸收峰明显变宽,强度也变大;锁阳在1 682cm-1处有较尖锐的吸收峰,1 605 cm-1附近的吸收峰强度也较大.二维红外谱图不但差别明显,而且直观.三者提取物的红外光谱同样存在显著差异.应用该方法能够实现肉苁蓉药材与混淆品的快速、准确鉴别.

Identification of Cistanche Deserticola from Boschniakla Rossica and Cynomorium Songaricum Using FTIR and Two-Dimensional Correlation IR Spectroscopy

In the present paper, Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D-IR) was used for the identification of Cistanche deserticola from its adulterants, Boschniakla rossica and Cynomorium songaricum. The results showed that these IR spectra showed their different macro-fingerprint feathers: the charactersistic peaks for Cistanche deserticola were located at ～1 730 and 931 cm-1. While absorption peaks at ～1 510, 1 375 and 1 266 cm-1 were only found in Boschniakla rossica. And the strongest peak of Cynomorium songaricum was at 1 614 cm-1. Differences were more obvious in the second derivative IR spectra: the intensities of the four peaks of Cistanche deserticola at ～1 453, 1 336, 931, and 892 cm-1 were strong, among which the peak at ～931 cm-1 was sharp and the strongest in intensity. There was the strongest peak at ～1 509 cm-1 for Boschniakla rossica. In addition, the shape of peaks at ～1 633 and 1 161 cm-1 was wider and the intensities were stronger. While the shape of peak at ～1 682 cm-1 was sharp, and also the intensity of peak at 1 605 cm-1 was stronger. According to the features of the IR spectra of each kind, a quick and accurate method based on FTIR for the identification of Cistanche deserticola was established.