2-（5-氯-2-吡啶偶氮）-5-二乙基氨基酚作络合滴定指示剂测定锌

Determination of Zinc by Complexometric Titration with 2-(5-Chloro-2-Pyridylazo)-5-Diethylaminophenol Indicator

摘要: 对2-（5-氯-2-吡啶偶氨）-5-二乙基氨基酚（5-Cl-DEPAP）作锌的络合滴定指示剂进行了实验。在pH5．5的HAc—NaAc介质中，以5-Cl-DEPAP作指示剂，EDTA标准溶液滴定锌，溶液颜色由紫红色变为亮黄色，终点变化敏锐，易于观察，锌量在0-25mg与EDTA消耗量成正比。方法用于化学试剂和铝合金中锌的测定，5次测定的RSD小于0．1％。结果表明，5-Cl-DEPAP符合络合滴定对指示剂的基本要求，扩大了该试剂的应用范围。

Abstract: An accurate and selective method for the determination of zinc by complexometric titration was developed.In the medium of acetic acid-sodium acetate(pH=5.5) and with 2-(5-chloro-2-pyridylazo)-5-diethylaminophenol(5-Cl-DEPAP) as indicator,the amount of zin