Determination of Antioxidant Activity of Chinese Herbs by Fluorometry with Benzoic Acid-Fenton System

A fluorescence product was formed between benzoic acid and hydroxyl free radical produced by Fenton system.Antioxidant can effectively eliminate hydroxyl free radical and reduce the amounts of fluorescence product,and then the intensity of fluorescence of the products in solution will be decreased.Based on this principle,a system for screening antioxidant was established.The method was applied to determine the antioxidant activity of some Chinese herbs.When the concentration of Chinese herbs was 0.4 mg(dry weight)/mL,the results showed that scavenging rate of the root of Kudzu vine,Evodia rutaecarpa and the rhizome of Chinese goldthread were 53.17%,58.58% and 67.80%,respectively.