Collect. Czech. Chem. Commun. 1985, 50, 2840-2852

Dynamic sorption of Cr3+ on strongly acidic cation exchangers and separation of Cr(VI), Cr3+ and cations interfering with the spectrophotometric determination of chromium

Jan Pancl

The J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 121 38 Prague 2


The dynamic sorption of Cr3+ on two strongly acidic cation exchangers, viz. the microreticular Ionenaustauscher I and the macroreticular Amberlyst 15, is studied by measuring the breakthrough curves for the hexaquochromium(III) ions, products of their partial hydrolysis, and mixtures of Cr3+ with Co2+, Cr2+, and Ni2+ ions, hence, ions interfering with the spectrophotometric determination of chromium. Analysis of the breakthrough curves made it possible to find the experimental conditions for the quantitative separation of Cr(VI) from Cr3+ and for the separation of chromium from the interfering cations. A procedure for the determination of Cr(VI), Cr3+ and total chromium in the presence of the interfering ions is based on the oxidation of Cr3+ with hydrogen peroxide, reduction of Cr(VI) with hydroxylammonium chloride, separation of Cr(VI) on a strongly acidic cation exchanger, and spectrophotometric determination of Cr3+ with DCTA.