Fluorescence Properties And Analytical Methods Of Scutellarin And Liquiritin

In this thesis, fluorescence properties of scutellarin(SL) and liquiritin, active ingredients of traditional Chinese medicine(TCM), are studied. A spectrophotometric method is utilized for the determination of SL in Breviscapine Injection. A thin-layer absorption scanning method is proposed for the determination of liquiritin in TCM materials Glycyrrhizae Radix et Rhizoma(Liquorice, Gancao in Chinese). The feasibility of using three dimensional fluorescence spectra coupled with second-order calibration method for determination of scutellarin in TCM Breviscapine Injection and liquiritin in TCM materials Gancao is investigated.In addition, absorption spectra of hesperidin, naringin and SL are studied, and a new method, p H-spectral resolution method based on alternating trilinear decomposition algorithm(ATLD), is proposed for determination of dissociation constant of organic weak acid.Three parts are included in the thesis:1. Fluorescence property and analytical method of SL are studied. The fluorescence of SL aqueous solution is very weak. Addition of borax and CTAB into the SL solution can enhance the fluorescence. The fluorescence excitation and emission wavelengths of the ternary system are 360 nm and 467 nm, respectively. Using quinine sulfate as a reference,fluorescence quantum yield of the ternary system is measured to be 0.014. The feasibility of using three dimensional fluorescence spectra coupled with second-order calibration method for determination of scutellarin in TCM Breviscapine Injection is investigated. Using a spectrophotometric method for the determination, an average results of standard curve method and standard addition method is obtained to be 4.02 mg·m L-1.2. Fluorescence property and analytical method of liquiritin are studied. Under weak acid condition, fluorescence excitation and emission wavelengths of liquiritin are 275 nm and 389 nm, respectively. Using L-tryptophan as a reference, fluorescence quantum yield of a liquiritin solution with p H 5.27 is measured to be 0.0038.Under weak alkaline condition, fluorescence excitation and emission wavelengths of liquiritin are 332 nm and 373 nm, respectively. Usingquinine sulfate as a reference, fluorescence quantum yield of a liquiritin solution with p H 9.80 is measured to be 0.0076. The feasibility of using three dimensional fluorescence spectra coupled with second-order calibration method for determination of liquiritin in TCM materials Gancao is investigated. A thin-layer absorption scanning method is established for the detection, and the content of liquiritin in a Gancao referenee crude herb sample is detected to be 2.76%.3. Absorption spectra of hesperidin 、 naringin and SL are studied. A p H-spectral resolution method is proposed for the determination of dissociation constant of organic weak acid. Dissociation constant of hesperidin is determined to be p Ka = 9.70; dissociation constants of naringin are determined to be p Ka1 = 8.80 and p Ka2 = 10.30; dissociation constants of SL are determined to be p Ka1 = 6.84, p Ka2 = 8.66 and p Ka3 = 11.45.