The Solvent Extraction of Ruthenium with 8-Hydroxyquinoline

Abstract

Abstract The solvent extraction behavior of ruthenium(IV) with 8-hydroxyquinoline has been investigated in detail using ruthenium-106 as a tracer. The complex formation in the aqueous phase is fairly slow and is the limiting step in the procedure, but it can be enhanced by heating. Complete extraction is attainable with n-butanol, benzene and other organic solvents after 8-hydroxyquinolate has been formed by one hour’s heating at 60°C with the excess reagent in an aqueous acetate medium of pH 4∼6. n-Propanol, especially when combined with n-butanol, is an efficient extraction solvent. The presence of ammonium salts, organic acids or their salts causes interference. 8-Hydroxyquinolate, once formed, remains extractable even at very low pH values. The stripping of ruthenium from the benzene extract is accomplished by contact with concentrated hydrochloric acid. This solvent extraction is applicable to the colorimetric determination of minute amounts of ruthenium and to the isolation of ruthenium activities in mixed fission products.