DETERMINATION OF VALENCE STATES OF IRON IN GLASS AND OF URANIUM IN CALCIUM FLUORIDE SINGLE CRYSTALS

The instantaneous oxidation of macro and semi-micro amounts of iron(II) in various types of glasses, of iron(II) in magnesium oxide, and of semi-micro quantities of uranium(III) or uranium(IV) in calcium fluoride single crystals, by excess of cerium(IV) present in the solvent system, followed by back-titration with iron(II) ammonium sulfate, is the basis for a simple, accurate method which, furthermore, obviates the need for an inert atmosphere. Formal oxidation potentials of the Ce(IV)/ Ce(III) couple and the Fe(III)/Fe(II) couple in the hydrofluoric-sulfuric acid glass-dissolving mixture were estimated. © 1969.