The spectrophotometric determination of zirconium in mild and low alloy steels

Abstract

The coloured complex that is formed between zirconium, Eriochrome cyanine R and polycyclic ketoamine has been studied and applied in the spectrophotometric determination of zirconium in mild steel at concentrations ranging from 0 to 0·1 per cent. with an estimated precision of ±0·003 per cent. of zirconium. By preliminary separation of zirconium with phenylarsonic acid, other elements that form complexes with Eriochrome cyanine R and polycyclic ketoamine are partially or totally removed. Provision is also made for the removal of elements that co-precipitate or adsorb zirconium in acidic solution, thus extending the method to include more complex steels. Titanium in amounts greater than 0·02 per cent. interferes. The main advantages of the method are that residual iron can be effectively masked without any loss in stability of the complex and that the molar absorptivity of the analytical complex is high.