关键词: 银, 罗丹明B, 催化褪色反应, 动力学分析法, 催化光度法

Abstract: In the presence of α,α'-bipyridyl as activator, the reaction between rhodamine Band potassium peroxydisulphate can be catalyzed by silver(Ⅰ) in acetic acid buffer solution (pH 4.9) with the result of decoloration of rhodamine B.The catalytic reaction is pseudo-zero-order in reactant and the apparent activation energy of catalytic reaction is found to be 37.66kJ/mol.A new catalytic spectrophotometry for determination of ultra-trace silver has been developed.The range of determination is 0.38-35 ng/25 mLsilver and the precision is 3.8%obtained from 11 standard solutions each of which contains 20 ng silver.The method has been applied to the determination of trace silver in ores.

Key words: Silver, Rhodamine B, Catalytic decoloration reaction, Kinetic analysis, Catalytic spectrophotometry