Extraction of polonium from aqueous α-hydroxyisobutyric acid solutions using dioctyl sulphide, Cyanex 272, Cyanex 301 or Cyanex 302 in toluene

A study of the extraction of polonium. from aqueous solutions containing alpha -hydroxyisobutyric acid (alpha -HIBA) was performed with four different extractants, di-n-octyl sulphide (DOS), Cyanex 272, Cyanex 301 and Cyanex 302, dissolved in toluene. The extracted complex for DOS at low alpha -HIBA concentrations is most likely PoO(alpha -HIB)(2)(.)2DOS, while at higher alpha -HIBA concentrations there seems to be a solvating effect implicating an extracted complex of the type PoO(alpha -HIB)(2)(alpha -HIBA)(2)(.)2DOS. For the extraction of polonium. with Cyanex 272 the results are inconclusive. The extracted complex is either PoOA(2) or PoO(alpha -HIB)(2)(.)2HA. For extraction with Cyanex 301 or Cyanex 302 the major extracted species does not contain any alpha -HIBA molecules. The neutral species in both cases is PoOA(2), extracted at low extractant concentrations, while at higher extractant concentrations a complex of the type PoOA(2)(.)xHA is extracted. The extraction of polonium increases in the order Cyanex 272 < DOS < Cyanex 302 < Cyanex 301.