An experimental study on four kinds of Chinese herbal medicines containing alkaloids using fluorescence microscope and microspectrometer

In order to find a useful method for uniting the identification and quality evaluation of Chinese herbal medicine, the techniques of fluorescence microscopy and microspectrometer were firstly applied to authenticate four kinds of herbal medicines, Caulis Sinomenii, Rhizoma Coptidis, Radix Sophorae Tonkinensis and Rhizoma Menispermi, as well as to measure the distribution of alkaloids in their cross-sections. The results showed that the fluorescence microscopic characteristics and the fluorescence emission spectra of the same tissues from the four kinds of Chinese herbal medicine were different, for example, the cortex of Radix Sophorae Tonkinensis emitted blue fluorescence instead of the yellow of Rhizoma Coptidis observed with emission filter of long-pass 397 nm, which could be effective to identify them. Furthermore, alkaloids, as active components of the above herbal medicines, were distributed in each part of herbal tissue but their fluorescence intensities in different parts of tissue were different. The results indicated that fluorescence microscope combined with microspectrometer could be a helpful method for identification and quality evaluation of Chinese herbal medicine.