Anion-exchange separation of iron,cobalt and nickel

From 90% acetone-10% 6 M hydrochloric acid medium, cobalt and nickel are strongly adsorbed on the anion-exchange resin Dowex I-X8; iron is not adsorbed and can thus be separated from cobalt and nickel. Cobalt and nickel are then separated by elution with 70% acetone-30% 2 M hydrochloric acid; nickel is eluted before cobalt. The method can be applied to the determination of nickel and cobalt in materials with high iron content such as steels ; compleximetric titrations are used for the final step.