Mutual Separation of Actinides from Middle Lanthanides by the Combination of Two Neutral Donors, N,N,N′,N′-Tetraoctyl-3,6-dioxaoctanediamide and N,N,N′,N′-Tetraethyldiglycolamide

The separation of Am and Cm from Sm, Eu, and Gd was examined by the combination of new extractant, DOODA (N,N,N′,N′-tetraoctyl-3,6-dioxaoctanediamide) and masking agent, TEDGA (N,N,N′,N′-tetraethyldiglycolamide). DOODA extracts light lanthanides with high D values into the organic phase, while TEDGA shows strong complexing ability with middle and heavy lanthanides in the aqueous phase. Americium and Cm behave as light lanthanides in this extraction system, therefore Am and Cm show high separation from middle lanthanides. The separation factors for D(Am)/D(Sm), D(Am)/D(Eu), and D(Am)/D(Gd) are 14.4, 40, and 111, respectively, for 0.3 M DOODA/n-dodecane and 10 mM TEDGA/5 M HNO3. The high separation of Am and Cm from these lanthanides, having high neutron cross section, can be seen in HNO3–n-dodecane in the absence of metal-salt.