Contributions to the complexometric determination of cation mixtures: Simultaneous titration of iron(iii) and aluminium in the presence of ammonium thiocyanate as indicator

With thiocyanate as indicator iron(III) and aluminium(III) can be titrated simultaneously if [Fe⁺³]/[Al⁺³] ? $\text{1}\text{4}$; iron(III) is titrated directly with EDTA, and aluminium(III) is determined by back-titration of the excess of EDTA with cobalt nitrate solution in an acetone-water medium.