Abstract
The transport of Au(III) and 19 other metal ions through a tributyl phosphate (TBP)-decalin membrane supported on a microporous polytetrafluoroethylene sheet was studied in order to establish a procedure for removing Au(III) ions from acid solutions of a gold target irradiated by high-energy heavy ions, leaving a multitracer solution in a carrier-and salt-free state. Distilled water was used as a stripping agent. A feed solution of 3mol dm-3 HCl gave the highest transport rate in the 0.1-8mol dm-3 HCl range. The transport of carrier-free radioisotopes of Sc, Fe, Zr, Nb, Te, and Hf was observed for 8mol dm-3 HCl and that of Fe, Zr, Nb, and Te for 5 and 6mol dm-3 HCl, while their transport was not detected for 0.1 and 1mol dm-3 HCl feed solutions and was small with 3mol dm-3 HCl. The 3mol dm-3 HCl solution is considered to be the best feed solution for preparing a multitracer from an Au target, because of the large transport rate of Au(III) and the negligible transport of other elements. The transport rates of Au(III) ions from 0.2-2mol dm-3 HNO3 solutions are smaller than those from 1-6mol dm-3 HCl. On the basis of these observations, a practical procedure was established for preparing a multitracer solution from a heavy-ion-irradiated Au target.
