Synergetic adsorption of copper(II) mixed ligand complexes onto the SEP-PAK C18 column

The synergetic adsorption onto SEP-PAK C18 column for copper(II) mixed ligand complexes with the mixture of ligands 2-thenoyltrifluoroacetone (TTA), tri-n-butylphosphate (TBP) and 8-hydroxyquinoline (oxine)-TBP was investigated as a model of the possible adsorption processes occurring in natural water environments. Measurements were performed in 0.55 M NaCl solution with constant concentrations of ligands and Cu(II) ions, and constant pH of 6. The remaining concentrations of dissolved Cu(II) after passing through the column and eluted concentrations of Cu(II) ions from the column with 0.1 M hydrochloric acid, were determined by the standard addition method at pH = 2, using differential pulse anodic stripping voltammetry (DPASV). Synergetic adsorption effects onto the column in the case of the Cu-TTA-TBP mixed ligand complex were observed giving 80% retention of Cu(II) on the column material. However, no synergetic adsorption was observed with the mixture of oxine-TBP ligands.