Exchange properties of collidinium tungstoarsenate

A new heteropolyacid salt exchanger was prepared by replacing ammonium ion in ammonium 12-tungstoarsenate by a larger tertiary base cation, 2,4,6-collidinium ion, which is found to be more stable in water, acids and neutral salt solutions than other heteropolyacid salt exchangers. Ksub(d) values for a number of metal cations were determined in acidic media at pH 3-4 and in 1 M nitric acid. The exchanger, unlike other heteropolyacid salts (which are mainly so far used for separation and determination of Cs+ and Rb+) shows high selectivity to ZrO2+ ions in 1 M nitric acid media and can, therefore, be used in the separation of radioactive zirconium in fission products. A large number of other separations of Th4+, Tl+, Fe3+ and La3+ are possible. Separations of La3+, from Ce3+, Y3+, In3+ and Ba2+ which are of great radioanalytical importance are achieved on the column of the exchanger. (author)