Determination of cyanide ion in cyano-complexes

Abstract

A method is described for the determination of the CN^– ion in a variety of cyano-complexes. The method is based upon mixing and grinding the sample with flowers of sulphur and potassium chloride in the ratio of 1:2:2; the addition of potassium carbonate is also essential with cyano-acid complexes. After mixing, a micro-amount is fused in a test-tube at about 300 °C for 2 minutes and the tube is then broken in a few millilitres of water. In this way the CN^– ion is converted quantitatively into CNS^–, which is determined colorimetrically. The average recovery is 98·54 per cent.