A new method for obtaining radiochemically pure67Cu from highly active fission product solutions is described. The method is based on the solvent extraction of the Cu(II)-diethyldithiocarbamate
complex in n-butyl acetate in the presence of hold-back carriers for Ni, Co, Mn, Mo, rare earths, Cd, Te and Sb, and subsequent
purification steps involving scavengings for Ag, Ba, Sr and Fe followed by an anion-exchange purification step for decontamination
from Te. Copper is finally extracted as the α-benzoin oxime complex in which form it is mounted and counted. The method has
several advantages over other methods in that decontamination is very high and it is sufficiently fast considering the stringent
radiochemical purity achieved. The67Cu separated by this procedure from a one-day-old mixture of fission products arising from 1010 fissions was found to be completely free of any contamination.