Collect. Czech. Chem. Commun. 1983, 48, 464-470

Spectrophotometric determination of zinc with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol

Juan Cacho and Cristina Nerin

Department of Analytical Chemistry, University of Zaragoza, Zaragoza, Spain


The reaction of Zn(II) with 5-methyl-1,3,4-thiadiazolyl-(2-azo-1)-2-naphthol (MTDAN) and extraction of the complex formed in chloroform is studied. The optimum pH range for the extraction and formation of the complex is 10-11.2 and Beer's law is obeyed in the interval of 0-2 ppm of Zn(II) in the organic phase. The molar absorptivity is 5.9 . 104 l mol-1 cm-1 at 568 nm. The stoichiometry of the complex corresponds to the type ML2. Some interferences are studied and an easy way is given to eliminate them. The results are compared with those corresponding to TAN. The reaction is applied to the analysis of synthetic samples of bronzes with satisfactory results.