麻黄生物碱中一对光学异构体在薄层色谱原位的表面增强拉曼光谱研究

应用表面增强技术(SERS)将薄层色谱(TLC)与傅里叶变换拉曼光谱(FT-Raman)联用，在薄层色谱分离斑点原位，获得中草药麻黄中麻黄生物碱衍生物中一对关于手性碳的光学异构体：去甲基麻黄碱，去甲基伪麻黄碱指纹光谱的新方法。研究表明，在薄层色谱原位仅16 μg的样品，就可获得以上分子的主要特征谱带;并且光学异构体的光谱特征明显不同，在银溶胶微粒表面增强作用下去甲基麻黄碱、去甲基伪麻黄碱分子中与苯环相关的波数为1 004，1 605 cm-1振动获最大增强。从而阐明了应用TLC-SERS联用技术，可有效地对中草药主要化学成分中光学异构体进行高灵敏度分离与指纹鉴定。

TLC-FT-SERS Study on a Pair of Optic Isomers in Ephedra

A new method for analyzing the ingredients of a pair of optic isomers in ephedra, nor-ephedrine and nor-pseudo-ephedrine, using hyphenated high-efficiency thin layer chromatography (TLC) and surface-enhanced Raman spectroscopy (SERS) techniques, is reported. The results show that the characteristic spectral bands of nor-ephedrine and nor-pseudo-ephedrine can be obtained from the TLC spot with 8 microg sample of about 2.0 mm in diameter. The difference between the SERS and solid spectra was found. Spectral bands at 1004 cm(-1) and 1605 cm(-1) were found greatly enhanced. Molecule was absorbed in surface silver sol by pi electrons in ring. Under similar experimental conditions the spectral information of Levo-nor-ephedrine ramifications TLC-SERS is rich with strong credibility, whereas dextral-nor-ephedrine ramifications show a relatively strong fluorescence backdrop with less spectral information and weak credibility. The effective combination of TLC and SERS can be used to analyse the chemical ingredients with high sensitivity.