2-(四氮唑偶氮)-5-二乙氨基苯甲酸指示剂络合滴定法测定钴  

DETERMINATION OF COBALT BY COMPLEXOMETRIC TITRATION USING 2-(TETRAZOLYLAZO)-5-DIETHYLAMINO BENZOIC ACID AS THE INDICATOR

作　　者：郑典慧[1] 梁华定[1] 葛昌华[1] 潘富友[1] 

机构地区：[1]台州学院化学系,台州317000

出　　处：《化学分析计量》2005年第1期26-28,共3页Chemical Analysis And Meterage

摘　　要：探讨 2 (四氮唑偶氮 ) 5 二乙氨基苯甲酸 (TTZDBA)作为络合滴定钴的指示剂的分析性能。在pH值为 7.0的NH3 ·H2 O -NH4Ac缓冲溶液中 ,加入 5滴TTZDBA作指示剂 ,用EDTA标准溶液进行滴定 ,滴定终点溶液的颜色变化敏锐 ,由紫红色变为亮橙色。将该方法用于试剂和钴基合金样品中钴的测定 ,测定结果与标准值相符 ,RSD(n =6 )为 0 .38%～ 1.5 2 %。Analytical behavior of 2 (tetrazolylazo) 5 diethylamino benzoic acid(TTZDBA) as the indicator in determination of cobalt by complexometric titration was investigated. The result shows that the titration end point of cobalt with EDTA standard soultion as titrant was found to be sharp in the buffer solution of NH 3 · H 2 O-NH 4 Ac (pH=7.0) containing five drops TTZDBA solution. The end point occurs when the solution colour changes from purple red to bright orange, the end point is sensitive. The method was applied to the determination of cobalt in reagent and cobalt base alloy, the results are consistent with the reference value and RSD is 0.38%～1.52%( n =6).

关 键 词：氨基苯甲酸 指示剂 RSD 测定结果 EDTA标准溶液 络合滴定法 试剂 分析性能 滴定终点 缓冲溶液 

分 类 号：O655[理学—分析化学] O657[理学—化学]