Colorimetric titration of vanadium with alkaline ferricyanide

The gradual disappearance of the yellow colour of ferricyanide with the addition of vanadyl ions in alkaline medium has been made the basis of the quantitative determination of both vanadium and ferricyanide. The colorimetric titrations were carried out with the aid of a Hilger Spekker Absorptiometer with a blue filter having maximum transmission in the range of 450–500 mμ. It is shown that the accuracy of the results compares favourably with those obtained by other standard procedures.