【摘要】 本文报道了新显色剂5－（4＇－溴－2＇－羧基苯偶氮）罗丹宁的合成及在水溶液中的离解常数Ka1和Ka2。研究了该显色剂与铜（Ⅱ）的显色反应，在弱酸性时，试剂与铜（Ⅱ）形成摩尔比2：1的络合物。摩尔吸光系数为8．9×104L·mol－1·cm－1。当铜的浓度在0～2．7mg／L的范围内符合比耳定律。用分光光度法测定了合金中铜的含量。更多还原

【Abstract】 The synthesis of a color reagent 5-(4’ -bromc-2’ -carboxyphenylazo ) rhodanine was described. The dissociation constants of the reagent Ka1 and Ka2 are given. The color re action of the reagent with Cu(Ⅱ ) is studied. The molar ratio of Cu(Ⅱ ) to the reagent is 1: 2. The Beer’ s law is obeyed in the range of 0~ 2. 7 mg/L for Cu (Ⅱ ) with of 8. 9× 104L· mol -1. cm -1. The method has been applied to the determination ot copper in alloy sample with satisfactory results.更多还原