Stability constants of minor actinides and lanthanides with dithiocarbamate

Miyashita, Sunao; Kitatsuji, Yoshihiro  ; Kimura, Takaumi 

The stability constants of trivalent minor actinides (An; Am and Cm) and lanthanides (Ln; Eu) with Ammonium pyrrolidinedithiocarbamate (APDC) in aqueous solution were investigated. The stability constants were obtained by back-extraction technique using di(2-ethylhexyl)phosphoric acid (HDEHP) as follows. Aqueous phase was acetic buffer solution from 0.02 to 0.10 mol/cm containing various concentrations of APDC. Organic phase was toluene or benzene solution containing HDEHP and trace amounts of the extracted radionuclide such as Am or Cm. Eqvolumes of the aqueous phase and the organic phase were mixed in vial and were shaken 30 minutes at 298 . The results show that minor actinides strongly interacted with dithiocarbamate. From those results, the obtained stability constants (, = 1, 2) for Am are log(Am) = 2.5 0.3, log(Am) = 4.3 0.2 at 298 .