Collect. Czech. Chem. Commun. 1980, 45, 54-79

The reactions of gallium, indium and thallium with 2-(2-pyridylazo)-1-naphthol-4-sulphonic acid and their spectrophotometric determination

Petr Voznica, Josef Havel and Lumír Sommer

Department of Analytical Chemistry, Purkyně University, 611 37 Brno


The complex equilibria of gallium, indium and thallium(III) with analytically important 2-(2-pyridylazo)-1-naphthol-4-sulphonate were studied spectrophotometrically using graphical analysis of the absorbance curves and minimization procedures for the absorbance data using the SPEKTFOT program on the Tesla 200 computer. The study yielded a complete picture of the reaction mechanism of these elements with heterocyclic azodyes. Optimum conditions for the spectrophotometric determination of gallium, indium and thallium using this reagent were found.