本文研究了在酸性条件下,用二苯硫腙(H_2D_2)的四氯化碳溶液萃取Cu(Ⅱ)时,2,2’-联吡啶(dipy)活化Cu(Ⅱ)催化H_2D_2氧化褪色反应的机理;测定反应前后有机相H_2D_2的吸光度(620nm)的改变,建立了测定痕量铜的新方法检出限为10~(-9)g/ml,测定范围为1.25×~(-9)10-1.0×10~(-7)g/ml.可应用于水样、高纯试剂中痕量铜的测定,方法可靠,结果令人满意. In this paper, the oxidative fading of H2O2 catalyzed by 2,2’-dipyridyl (Cu2 +) catalyzed by 2,2’-bipyridyl (dipy) was studied under acidic conditions when Cu (Ⅱ) was extracted by carbon tetrachloride solution of diphenylthia hydrazone The detection limit of the new method for the determination of trace copper was 10 -9 g / ml and the determination range was 1.25 × -9 -1.0 × 10 ~ (-7) g / ml. It can be used in the determination of trace copper in water sample and high purity reagent. The method is reliable and the result is satisfactory.