紫花地丁与长萼堇菜的傅里叶变换红外光谱鉴别

Identification of Viola yedoensis Makino and Viola inconspicua by FT-IR

应用傅里叶变换红外光谱法对紫花地丁与长萼堇菜的提取物及不同萃取部位进行结构分析及鉴别研究。紫花地丁与长萼堇菜的提取物的一维红外谱图显示两者均具有芳香类物质,挥发性物质及糖苷类物质。两者不同萃取部位的二阶导数谱差异较为明显,尤其在970~800 cm^(-1)范围内的自动峰数量和峰强的差别明显。在石油醚萃取部位的二阶导数谱图中,紫花地丁出现了5个自动峰,而长萼堇菜有7个自动峰,且峰强大于紫花地丁;在氯仿萃取部位的二阶导数谱图中,长萼堇菜出现了6个自动峰,而紫花地丁则出现4个自动峰,二者峰强差别较小;在乙酸乙酯萃取部位的二阶导数谱图中,紫花地丁出现了6个自动峰,而长萼堇菜出现了4个自动峰。同时在乙酸乙酯萃取部位的二阶导数红外谱图中紫花地丁最强峰的出峰位置在1 467 cm^(-1)处,而长萼堇菜最强峰出峰位置在1 384 cm^(-1)处,可以将二者区分开。研究表明,一维红外光谱与二阶导数分析方法相结合,能够实现紫花地丁与长萼堇菜的区分鉴别,该法准确可靠,为紫花地丁及其他混淆品的鉴别提供新思路和新方法。

The different extracts and of Viola yedoensis Makino and Viola inconspicua were analyzed and identified by Fourier transform infrared spectroscopy（ FT-IR）. One-dimensional infrared spectrum showed that the extracts of Viola yedoensis Makino and Viola inconspicua contained the aromatics,volatile substances and glycosides,with not significant differences from each other. However, different extraction sites of the two medicinal materials in second derivation spectrum were obviously different,especially the number of automatic peaks and peak intensity in the range of 970-800 cm^-1. Viola yedoensis Makino displayed 5 automatic peaks,6 automatic peaks and 6 automatic peaks,while Viola inconspicua displayed 7 automatic peaks,4 peaks,4 peaks in the second derivation spectrum of petroleum ether extraction site,chloroform extraction site and the ethyl acetate extraction site. In addition,the peak position of the strongest peak in the second derivative of the ethyl acetate extraction site was 1 467 cm^-1,while the strongest peak of the Viola inconspicua was at 1 384 cm^-1,so the two medicinal materials can be distinguished by the strongest peak position of ethyl acetate extraction site in second derivation spectrum. Studies demonstrated that one-dimensional infrared spectroscopy combined with the second-order derivative analysis could achieve the accurate identification between Viola yedoensis Makino and Viola inconspicua. This research provides new ideas and new methods for the identification of Viola and other adulterants.