Abstract
The distribution ratios of copper(II) ion between an aqueous solution containing mixtures of Cu(NO3)2-HNO3-KNO3, at various pH and the organic phase containing bathocuproine(L) in 1,2-dichloroethane were measured. From the variation in the absorption spectra, it was found that the ligand is distributed between both phases by forming HL+ in the aqueous phase and HLX in the organic phase, respectively, in the range of pH from about 1 to 5.5. The extractability of copper(II)-complex, CuL2(NO3)2, decreases rapidly with the decrease in pH value of the aqueous solution. As a result, it became clear that the effect of hydrogen ion on the distribution ratio can be utilized for the concentration and separation of copper(II) ion through a liquid membrane between both aqueous phases of Cu(NO3)2 at different pH.
