用巯基乙酸作解蔽剂选择性络合测定铜

Selective Comp lexometric Determination of Copper with Thioglycollic Acid as Demasking Agent

本文描述了一种用巯基乙酸作解蔽剂选择性络合测定铜的方法。加入过量EDTA到铜试液中,其剩余部分用锌溶液于pH=5-6返滴定至二甲酚橙终点。然后加入巯基乙酸解蔽Cu(Ⅱ)—EDTA络合物,释放出的EDTA再同上滴定之。各种阳离子的干扰加以了研究,本法可用于测定各种试样中的铜量。

A method is described for selective complexometric determination of copper( Ⅱ ),thioglycollic acid being used as demasking agent. To a given sample solution containing coppper , eicess of EDTA is added and the surplus is back-titrated at PH 5-6 With zinc solution to xylenol orange end point. Thioglycollic acidis then added to demask the copper-EDTA complex and the liberated EDTA is again titrated as above . The interference of various cations has been studied, and the method may be employed to determine copper content in a variety of samples.