丁基罗丹明B-Fe^(2+)-H_2O_2体系荧光法测定茶叶的抗氧化活性

Determination of Antioxidant Activity in Several Kinds of Tea by Fluorimetry with Butyl RhB-Fe^(2+)-H_(2)O_(2) System

丁基罗丹明B本身能产生特征荧光,其激发波长和发射波长分别为560nm和582nm。在酸性介质中,Fe2+-H2O2体系产生的羟自由基可以迅速氧化丁基罗丹明B使其荧光猝灭,而茶叶的水提取物可以部分清除溶液中的羟自由基,从而使其荧光猝灭程度减弱。据此建立了一种测定茶叶抗氧化性的新方法。

Butyl RhB can produce its characteristic fluorescence with its excitation and emission wavelength at 560 nm and 582 nm, respectively. Butyl RhB is rapidly oxidized by hydroxyl radical and fluorescence is quenching. Extractives of teas may eliminate hydroxyl radical in solution. Then，quenching level of fluorescence of solution will be lowered. Based on this principle,a new method is developed to determine eliminating ratio of tea for hydroxyl radical. The antioxidative activity of 7 kinds of teas is determined.