5-Br-PADAP〔学名2-(5-溴-2-吡啶偶氮)-5-二乙氨基苯酚〕光度法测定Cu(Ⅱ)已有报导。但一价铜与该试剂的显色反应尚未见有人研究。我们发现有阴离子表面活性剂存在时,在微酸性溶液中,5-Br-PADAP是Cu(Ⅰ)的灵敏显色剂,反应的灵敏度较高,选择性和稳定性较好,可用掩蔽剂消除Fe(Ⅲ)、Co(Ⅱ)、Ni(Ⅱ)、Zn(Ⅱ)等离子的干扰。 (一)主要试剂和仪器 Spectrophotometric determination of Cu (Ⅱ) with 5-Br-PADAP [2- (5-bromo-2-pyridylazo) -5-diethylaminophenol] has been reported. However, there has been no research on the color reaction of monovalent copper with this reagent. We found that in the presence of anionic surfactant, 5-Br-PADAP is a sensitive reagent of Cu (Ⅰ) in slightly acidic solution. The reaction has high sensitivity, good selectivity and stability and can be eliminated by masking agent Interferences of Fe (Ⅲ), Co (Ⅱ), Ni (Ⅱ) and Zn (Ⅱ) plasmas. (A) of the major reagents and equipment