[en] The fraction of exchange has been reported for a heterogeneous isotopic exchange system between cesium-134 ions in solution and cesium triphenylcyanoborate precipitate. A number of variables such as aging of the precipitate, mode of preparation and exchange media were studied aiming at radiochemical separation of cesium from its active solution

[en] Thorium(IV) and uranium(VI) chelate complexes with PAN, PAR, TAN and TAR have been studied in absolute ethanol. The uranyl ion forms complexes with PAN, PAR, TAN and TAR in the metal to ligand molar ratio of 1:1. Thorium(IV) forms complexes with PAR, TAR and TAN in the molar ratio of 1:2. In case of Th(IV)-PAN complexes the molar ratio is 1:2.4. The stability constants for all the above complexes have been worked out using the mole ratio method. The kinetics of aquation of Th(IV)-PAN complexes indicate that PAN acts as a tridentate ligand. (author)

[en] A spectrophotometric method for the estimation of thorium(IV) with 1-(2-pyridylazo)-2-naphthol, PAN, in 40% v/v ethanol-water mixture is described. A good correlation is found between the absorbance and Th(IV) concentration at pH = 2 and pH = 3, in solutions of ionic strength = 1.0 (NaClO⁴). The effects of varying Th(IV) and PAN concentrations and pH are discussed. The ratio of Th(IV):PAN in the complex, at pH = 3 is 1:1, whereas at pH = 2 it is probably 1:2. The complexes appear to be relatively unstable. (author)

[en] The uptake of Cs-137 is reported for two main techniques, namely, precipitation, in situ, with the insoluble zinc hexacyanocobaltate (III), and using preformed precipitates. Various parameters have been studied such as the initial ratio of the reacting components, K₃ [Co (CN)₆] and ZnSO₄ acidity, cesium concentration, exchange time and the amount and aging of the zinc hexacyanocobaltate (III) precipitate. An uptake of 100% is achieved using different preformed precipitates for cesium concentration up to 10-³M. The inorganic exchanger, KZn (Co(CN)₆) 3.5 H₂O, has been prepared. An uptake of 99.9% of Cs-137 is achieved by batch equilibration, where V/m=100, for cesium concentration up to 10^-3M