Nonaqueous titrimetric determination of ultramicro amounts of zinc, cadmium, and magnesium with EDTA-type chelating agents using metallochromic indicators

Abstract

A nonaqueous titrimetric method in formamide and dimethyl sulfoxide, for the determination of zinc, cadmium, and magnesium with some amino polycarboxilic acids (EDTA, NTA, DCTA, and HEDTA) using PAN or Eriochrome black T as metallochromic indicator, was developed. These titrations were applied for the rapid determination of ultramicro amounts of magnesium and zinc in water-insoluble magnesium, i.e., zinc stearates. From 1 to 12 μg of metals in a 0.5-ml sample can be titrated with the error of ±0.7% and a standard deviation up to 0.6%. © 1969.