Distribution coefficients of polonium between 5% TOPO in toluene and aqueous hydrochloric and nitric acids

The distribution coefficients (D) of polonium between 5% TOPO in toluene and aqueous hydrochloric and nitric acids have been studied. Results show that: (1) D values are ranged from 61.3 to 331 when the acidities vary from 0.10 to 10.0 M HCl, which means that Po can be well extracted by 5% TOPO in toluene in wide range of HCl acidities, (2) in the acidities of 0.010-10.0 M HNO3 the D values are much lower, there exists a maximum D value (2.46) at 1 M HNO3, and at the acidities of 6 M HNO3 and above only a negligible amount of Po (less than or equal to 1.5%) can be extracted by 5% TOPO in toluene. The later fact provides an opportunity to separate Po from uranium effectively in the process of liquid-liquid extraction and column extraction chromatography of TOPO. (C) 2004 Elsevier Ltd. All rights reserved.