Solvent extraction and extraction chromatographic separation of Am3+ and Eu3+ from nitrate medium using Cyanex® 301

The separation behavior of trivalent actinides and lanthanides from aqueous nitrate medium has been investigated using purified commercial Cyanex (R) 301 [bis(2,4,4-trimethylpentyl)dithiophosphinic acid] in toluene by solvent extraction as well as by extraction chromatography. The separation studies were carried out using Am3+ and Eu3+ as the representative actinide and lanthanide ion, respectively. The stoichiometry of the extracted species as determined by the slope-analysis method was Am(A)(3) and Eu(A)(2)(NO3), when HA (Cyanex 301) concentration was < 0.3 M At a higher extractant concentration, the stoichiometry of the extracted Eu complex was Eu(A)(3). Extraction chromatographic studies were carried out in the presence of several complexing agents that tend to influence the separation factor (D-Am/D-Eu) values. The solvent extraction and extraction chromatographic studies have yielded separation-factor values of 4900 and 526, respectively.