Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

Extraction of Eu³⁺ and Ce³⁺ microamounts from 0.1-0.4M perchloric acid by the nitrobenzene solution of dicarbolide H⁺[Co(C₂B₉H₁₁)₂]^- in the presence of polyethylene glycols (M_r = 200, 300, 400) has been studied. The equilibrium data and the typical maxima on the dependence of the metal distribution ratio on the total analytical concentration of polyethylene glycol in the system can be explained assuming that the species ML³⁺_org, ML³⁺_2org, ML³⁺_3org, MLH²⁺_-1org, and HL⁺_org (where M³⁺ = Eu³⁺, Ce³⁺; L = polyethylene glycol) are extracted into the organic phase. The values of extraction and equilibrium constants in the organic phase were determined and the effect of the polyethylene glycol molecular weight on the equilibrium constants and on the abundances of individual species in the organic phase is discussed. It has been found that the addition of polyethylene glycol to the acid - nitrobezene - dicarbolide system increases the values of the separation factors α_Ce/Eu.