Étude polarographique du niobium dans les mélanges eau – fluorure d'hydrogène

Abstract

Solubilization in hydrogen fluoride is required for the analysis of some minerals. A method of analysis directly applicable to water – hydrogen fluoride mixtures was worked out.However, in 50% hydrofluoric acid niobium is soluble as [Formula: see text] complex, which can be reduced with a polarographic electrode at a potential of −0.880 V vs. E.C.S. For concentrations lower than 45% in HF, the niobium complex is hydrated and exists as a non-reducible ion [Formula: see text].