Studies on Analytical Methods for Trace Elements in Metals by Using Radioactive Isotope. V : Determination of Hafnium in Zirconium by Means of Isotope Dilution Method

A method for the determination of hafnium in zirconium metal was studied. Hafnium was enriched from hydrochloric acid solution of zirconium sample with four steps of thiocyanate-hexone extraction-stripping method. After the several steps of extraction, pure hafnium fraction was obtained by passing the solution through the cation exchanger resin column, and eluting with the mixture of 0.45 M nitric acid and 0.095 M citric acid as an eluent. Combining the isotope dilution method and the above mentioned method, hafnium which existed from 0.025 to 0.1 per cent in zirconium was determined.