DIRECT CERIMETRIC DETERMINATION OF TELLURIUM(IV)

A direct cerimetric determination of tellurium(IV) is reported. The de termination can be accomplished either in hot 1-5 M sulphuric or 1-2 M nitric acid medium in the presence of ruthenium(III) as catalyst. Dir ect self-indicating end point titration can be carried out with standa rd solutions of ammonium cerium(IV) sulphate and ammonium cerium(IV) n itrate as oxidants in the sulphuric and nitric acid media, respectivel y. The method is also extended to the analysis of tellurium(VI)-tellur ium(IV) mixtures.