Fluorescence Enhancement And Fluorometric Analysis Of Myricetin,morin And Silybin

In this thesis,the fluorescence enhancement reaction of flavonols,myricetin and morin,and dihydroflavonol compound silibinin,are studied.Based on this,fluorometric methods for the determination of myricetin in XianChiShePuTao ZongHuangTong HanPian?XCS?and in Moyeam,as well as silybin in Silybinin Capsules,are developed.Three parts are included in this thesis:1.Fluorescence enhancement reaction of myricetin is studied.The fluorescence of myricetin is very weak,but the fluorescence is enhanced when ZrOCl₂ is added into the myricetin solution.The excitation wavelengths(?_ex)are 275 nm and 465 nm,emission wavelength(?_em)is 545 nm.The optimum condition of fluorescence enhancement reaction is investigated.The fluorescence quantum yield of myricetin is measured to be 0.045.Based on the fluorescence enhancement reaction of myricetin,a fluorometric method and a three-dimensional fluorescence coupled with second-order correction method are developed for the determination of myricetin in XCS and in Tengcha samples.The content of myricetin in XCS is 2.77%,and the myricetin content in Moyeam is 0.229%.UV spectrophotometry and high performance liquid chromatography are used to verify the fluorescence method.The results show that the fluorometric method has good selectivity,high sensitivity and reliable results.It can be used as a method for the analysis of myricetin in medicine.2.Fluorescence enhancement reaction of morin is studied.The fluorescence of morin is very weak,but the fluorescence can be enhanced when ZrOCl₂ is added into the morin solution.The excitation wavelengths(?_ex)are 275 nm and 445 nm,emission wavelength(?_em)is 530 nm.The optimum condition of fluorescence enhancement reaction is investigated,and the fluorescence quantum yield of morin is measured to be 0.079.3.The fluorescence enhancement reaction of silybin is studied.Silybin has none fluorescence,but when MgAc₂ is added into the morin solution,fluorescence is produced with excitation wavelengths?_exx of 315 nm and 440 nm,and emission wavelength?_emm of 510 nm.The fluorescence intensity increases when NaOH is added.The fluorescence quantum yield of silybin is measured to be 0.016.Based on the sensitized fluorescence,a new fluorometricmethod for the determination of silybin in Silybinin Capsules is established.Using the new method,the content of silybin in Silybinin Capsules is determined to be 14.5%.The result is verified by an UV spectrophotometric method,and show that the new method has good selectivity,high sensitivity and reliable results.