Abstract: Butyl Rhodamine B was oxidized by hydroxyl radical rapidly and decolorized in dilute sulfuric acid medium.The change in absorbance , corresponding to color intensity change of Butyl Rhodamine B can be determined at 558 nm, so the amount of ·OH produced can be determined indirectly. Extractives of vegetable might eliminate hydroxyl radical in solution and further dereases the decline of absorbarce of solution.Based on above-mentioned principle, a new method was developed to determine the eliminating ratio of...