2－（3，5－二氯－2－吡啶偶氮）－5－二甲氨基苯胺作为铜的络合滴定指示剂的研究

Studies on 2-（3，5-Dichloro-2-Pyridylazo）- 5-Dimethlaminoaniline as lndicator for Copper in Complexometric Titration

研究了２－（３－５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺作为钢的络合滴定新指示剂。结果表明，试剂能在ｐＨ３．０～６．５时以ＥＤＴＡ滴定铜，终点由紫色突变为黄色（铜量多时为绿色）。终点变化敏锐，准确度高，比ＰＡＮ、ＰＡＲ等优越。该法可用于矿石中铜的测定。

2-（3，5-dichloro-2-pyridylazo）-5-dimethylaminoaniline（3,5-diCl-PADMA）as a newindicator for copper in complexometric titration is invastigated.The result shows that the end-point ofthe titration of copper with the reagent is found to be much sharper at pH 4.0.The reagent is highlysensitive. Many common metals do not interfere except Zn,Pb and Ni.The method has been used for the determination of copper in ores.