Catalytic thermometric endpoint indication of chelatometric titrations by means of oxidation reactions of organic compounds with hydrogen peroxide

Abstract

The application of several oxidation reactions with hydrogen peroxide as exothermic indication reactions to catalytic thermometric end-point detection of chelatometric titrations is described. This time the oxidations of resorcinol and catechol, both catalyzed by copper(II), as well as the oxidations of hydroquinone and dimethyl-p-phenylenediamine, both catalyzed by copper(II) and iron(III), have been used as indicator systems. The titrations of EDTA, DCTA and NTA with copper(II) and iron(III), the invers titration of these metals, as well as the determination of a number of metal ions (alkaline earth metals, Cu2+, Ni2+, Co2+, Zn2+, Sn2+, Fe3+, A13+, Cr3+, Sb3+, In3+, Ga3+ and Th4+) by backand substitution titrations have been developed. The ions mentioned can thus be determined in the milligram and in the microgram range with reasonable accuracy. © 1973 Springer-Verlag.