Fluorometric Analysis Of Chinese Medicine Huhuanglian And Shegan By Aluminum Ion Sensitized Fluorescence

Fluorescence spectra of vanillic acid in Chinese herbal medicine Rhizoma picrorhizae (RP, Huhuanglian in Chinese) and Belamcanda chinensis (BC, Shegan in Chinese) were studied in this thesis, influences of experimental conditions on fluorescence spectra were investigated to establish the best conditions for fluorescent reactions of vanillic acid and BC. A solution fluorometric method and a thin-layer fluorescence scanning method were established for the analysis of vanillic acid in RP, and three-dimensional fluorescence spectra of RP and BC were investigated to establish a 3D fluorescence identification method for RP and BC crude drugs.Three parts were included in this thesis:1. Fluorescence spectra of vanillic acid, an active component of Chinese herbal medicine RP, were studied. It was found that solution acidity had great effect on the fluorescence of vanillic acid. Ionization constant of vanillic acid was determined to be pK_a = 9.11 by pH-absorbance method. Fluorescence of vanillic acid was very week. Addition of aluminum ion into vanillic acid solution can notably enhance the fluorescence. Using L-Trp as a reference, fluorescence quantum yield of Al(III)-vanillic acid system at maximum excitation wavelength 264 nm was measured to be 0.14.2. Fluorescence spectra of RP methonal extraction and the fluorescence sensitizing effect of aluminum ion on RP were studied. A new solution fluorometric method and a thin-layer fluorescence scanning method were established for the determination of vanillic acid in a RP sample. Using the two methods, vanillic acid in a RP sample were determined to be 0.449%and 0.482%, respectively. Besides, 3D fluorescence spectra of RP crude drug and its counterfeit drugs were also investigated, and thereby a 3D fluorescence method for identification of RP drugs was established.3. The native fluorescence of BC extraction was very week, but addition of AlCl3 into BC solution can observably enhance the fluorescence. Fluorescence properties of AlCl3-BC system were studied, and the optimal experimental conditions for sensitization fluorescence were explored. Three-dimensional fluorescence spectra of BC crude drug and its counterfeit drugs were investigated, and a 3D fluorescence method for identification BC drugs was then established.