2-(5-氯-2-吡啶偶氮)-5-二乙基氨基酚作指示剂络合滴定连续测定铜和锌

2-(5-chloro-2-pyridylazo)-5-diethylaminophenol as complexometric titration indicator for the continuous determination of copper and zinc

在pH5．5的HAc—NaAc缓冲溶液中，以2-（5-氯-2-吡啶偶氮）-5-二乙基氨基酚（5-Cl-DEPAP）为指示荆，EDTA标准溶液滴定铜、锌，滴定终点颜色变化敏锐，准确度较高，铜和锌量各在0～25mg范围内与EDTA消耗量成正比，铜、锌质量比在1：10～10：1范围内相互无影响。方法用于合成样品中铜、锌的连续测定。结果满意。

An accurate and selective method for the continuous determination of copper and zinc with 2-（5- chloro-2-pyridylazo）-5-diethylaminophenol（5- Cl-DEPAP）as complexometric titration indicator and EDTA as titrant is described in the medium of acetic acid - sodium acetate at pH 5.5. The end points for copper and zinc are sharp. The amounts of copper and zinc are directly proportional to the volume of EDTA solution consumed in the range of 0- 25 mg,and copper and zinc do not interfere with each other in the mass ratio of 1：10 - 10：1 .The method has been used for the determination of copper and zinc in synthetic samples with satisfactory results.