1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸作指示剂络合滴定连续测定铜和锌

1－(5 －Bromo -2 -pyridylazo )-2 -naphthol -6 -sulphonic Acid as Complexometric Titration Indicator for Continuous Determination of Copper and Zinc

对５－Ｂｒ－ＰＡＮ－Ｓ作指示剂络合滴定连续测定铜和锌进行了研究。在 ｐＨ ６．０的乙酸－乙酸钠介质中，以５－Ｂｒ－ＰＡＮ－Ｓ作指示剂，ＥＤＴＡ为滴定剂连续测定铜和锌，滴定终点颜色变化敏锐，准确度高，铜和锌量各在０～２０ｍｇ范围内与ＥＤＴＡ用量成正比，铜、锌比例在１：１０－１０：１范围内相互无影响。方法用于合金中铜、锌的连续测定，结果满意。

An accurate and selective method for the continuous determination of copper and zinc with l-(5-bromo-2-pyridylazo ) -2-naphthol-6- sulphonic acid (5 - Br- PAN- S ) as the complexometric titration indicator is described in the medium of acetic acid-sodium acetate at pH 6.0. The end points for both copper and zinc are sharp. The amounts of copper and zice are directly proportional to EDTA solution consumed in the range of 0 - 20 mg, and do not interfere with each other in foe concentration range of 1: 10-10: 1. The methed has ben used for the continuous determination of copper and zinc in alloys with satisfactory results.