Quinaldinic Acid as a Micro-reagent

TLDR: In this article, a method for the micro-estimation of zinc by means of quinaldinic acid in the presence of copper, silver or mercury individually, or in the case of both silver and mercury, is described.

Abstract: A method for the micro-estimation of zinc by means of quinaldinic acid in the presence of copper, silver or mercury individually, or in the presence of both silver and mercury, is described. It depends upon the use of thiourea for masking the reaction of copper, mercury and silver ions with which it forms stable complexes in acid solution. In the case, where copper is present, a previous addition of sodium bisulphite is necessary to reduce the cupric to cuprous ion. Zinc is precipitated as usual in acetic acid solution by the addition of sodium quinaldinate.