Nitrogenous synergists induced potentiometric response to metal ions with polymeric liquid membranes containing thenoyltrifluoroacetone as an ionophore.

The effects of nitrogenous synergists on the potentiometric responses to divalent transition metal ions were investigated concerning polymeric liquid membranes containing thenoyltrifluoroacetone (Htta) as an ionophore. The tested synergists were pyridine (py) and 4,4'-dioctyl-2,2'-bipyridyl (C8bpy). The potentiometric responses to metal ions, such as Cd2+, Co2+, Ni2+ and Zn2+, were induced by adding the synergists into the liquid membrane systems. The coexistence of Htta and a synergist was necessary for generating the membrane potential. The tta- anion adsorbed at the liquid membrane/solution interface and the complex formation between the synergist and a given metal ion appeared to participate in preferential uptake of metal ions.