Determination of hydroxyl radical by capillary electrophoresis and studies on hydroxyl radical scavenging activities of Chinese herbs.
High-performance capillary electrophoresis (CE) with electrochemical detection (ED) was employed to determine hydroxyl radicals in the Fenton reaction. Hydroxyl radicals can react with salicylic acid to produce 2,3-dihydroxy benzoic acid and 2,5-dihydroxy benzoic acid, which can be analyzed by CE-ED. Based on this principle, hydroxyl radicals were determined indirectly. In a 20 mmol/L phosphate running buffer (pH 7.4), 2,3-dihydroxy benzoic acid and 2,5-dihydroxy benzoic acid would elute simultaneously from the capillary within 6 min. As the working electrode, a 300 microm diameter carbon-disk electrode exhibits good responses at +0.60 V (vs. SCE) for the two analytes. Peak currents of the two analytes are additive. Excellent linearity was obtained in the concentration range from 1.0x10(-3) mol/L to 5.0x10(-6) mol/L for 2,3-dihydroxy benzoic acid. The detection limit (S/N=3) was 2.0x10(-6) mol/L. This method was successfully applied for studying hydroxyl radical scavenging activities of Chinese herbs. It is testified that Apocynum Venetum L., Jinkgo bibola L., Morus alba L. and Rhododendron dauricum L. have strong hydroxyl radical scavenging activities.
Cao
Yuhua
Y
School of Chemical and Material Engineering, Southern Yangtze University, 214036, Wuxi, P. R. China.
Chu
Qingcui
Q
Ye
Jiannong
J
D004365:Drugs, Chinese Herbal / Q000032:analysis* / Q000737:chemistry* / Q000145:classification; D004563:Electrochemistry / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods*; D016166:Free Radical Scavengers / Q000032:analysis* / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000032:analysis* / Q000737:chemistry*
D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D017665:Hydroxyl Radical