Investigation On Determination Methods Of Phenols In Chinese Traditional Medicine By HPLC-ECD

The phenol compound, included phenolic acids and flavonoids, is a kind of biological and pharmacological activity compound. In this thesis, phenolic acids and flavonoids in Chinese traditional medicine and herb were detected by high performance liquid chromatography-diode array detector-electrochemical detector (HPLC - DAD - ECD). Additionally, enhancive sensitivity by additive mobile phase and off-line pre-column derivation were combined with HPLC-ECD or HPLC-ECD-DAD to detect phenols compound. The present studies hold very important significances in both quality control of Chinese traditional medicine and broadening the application range of HPLC. This thesis consists of four chapters, and he author's works are as follows:1. An HPLC-ECD-DAD method for simultaneous separation and determination of the contents of chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid and apigenin in Lonicera japonica Thunb, Rosa rugosa Thunb, Chrysanthemum indicum L and Carthamus tinctorius L was established. The experimental results indicated that all calibration curves showed good linearity (r≥0.9992) and the average recoveries of five compounds ranged from 96.0% to 102.2% (RSD<2.9%). Compared with HPLC-DAD, HPLC-ECD is more sensitive for determination of electrochemical active compounds. Moreover, compared with HPLC-DAD or HPLC-ECD, HPLC-ECD-DAD is a rapid, simple and sensitive determination method for multi-components with electroactivity and non-electroactivity.2. An HPLC-ECD-DAD method for simultaneous determination of the contents of podophyllotoxin, kaempferol and quercetin in Dysosma pleiantha (Hance) Woods was established. The experimental results indicated that the average recoveries of three compounds ranged from 96.1% to 98.3% with RSDs of 0.6-2.2%. The proposed method is simple and shows good reproducibility, which is suitable for the determination of the contents of podophyllotoxin, kaempferol and quercetin in Dysosma pleiantha (Hance) Woods.An HPLC method for simultaneous determination of the contents of vanillic acid, chlorogenic acid, rutin, matrine and oxymatrine in Fufangshiwei capsules was established. The standard curve method was employed for quantification. The experimental results indicated that the average recoveries of five compounds ranged from 97.5% to 103.8% with RSDs of 0.6-2.8%. The study can provide a scientific basis for the quality control of Fufangshiwei capsules.An HPLC-ECD-DAD method for simultaneous determination of the contents of caffeic acid, baicalin and luteolin in Xinqin granules was established. The baicalin was detected by HPLC-DAD, and both the caffeic acid and the luteolin were detected by HPLC-EAD. The experimental results indicated that the average recoveries of three compounds ranged from 96.5% to 104.4% with RSDs of 2.1-3.9%.3. Using tetraethylammonium bromide as sensitizer, a new HPLC-ECD method for determination of naringenin in two Chinese herbs was established. The experimental results indicated that the linear range of naringenin was 4.10-1.54×10²Î¼g·mL^-1 (r=0.9971). The recovery was 95.1-102.7% (RSD<3.0%). Compared with HPLC-DAD, the new method is more sensitive.4. A new method of HPLC-ECD-DAD using off-line pre-column reaction for the investigation of radical scavenging capacity of gallic acid, ellagic acid and quercetin was established. Moreover, the method was used to investigate radical scavenging capacity of Euphorbiae humifusae. The recoveries of three compounds ranged from 96.8% to 104.7% (RSD<2.8%). The method can be used to identify the components which possessed antioxidation of the Chinese herb.