Analysis of mixtures of citric and oxalic acids based on their oxidation with potassium permanganate and manganese(III) sulfate

A determination of mixtures of citric and oxalic acids has been developed based on quantitative oxidation of the two substances with excess potassium permanganate to carbon dioxide and water and on quantitative oxidation of oxalic acid to carbon dioxide and water and of citric acid to carbon dioxide and formic acid with excess manganese(III) sulfate. The content of the two substances in mixtures can be calculated from the different consumption in these two oxidimetric determinations; a single standard solution of potassium permanganate can also be used for the preparation of manganese(III) sulfate.