THE ION TRANSFER FROM AQUEOUS(W), FORMAMIDE(FA) OR W-FA MIXTURES TO ORGANIC SOLUTION STUDIED BY POLAROGRAPHY AT THE ELECTROLYTE SOLUTION DROPPING ELECTRODE

Formamide or aqueous-formamide mixture is introduced for the ion transfer voltammetry at a liquid/liquid interface as one phase in place of the aqueous phase. The transfer of I- BF4-, ClO4- and CH3(CH2)(n)(CH3)(3)N+ (n >= 1) was investigated at the interface of aqueous, forrnamide or the aqueous-formamide mixtures and 2-nitro-m-xylene. The transfer of these ions was confirmed to be polarographically reversible. The relations are discussed between the standard Gibbs transfer free energy, Delta G degrees(tr), of these ions and the nature of the transferring ions or the properties of solvents based on the half-wave potentials in the polarograms. The Delta G degrees (tr) of small anions from formamide to nitroxylene are smaller than those from aqueous. The effect of the addition of CH2 in CH3(CH2)(n)(CH3)(3)N+ on Delta G degrees(tr) from formamide to rtitroxylene is smaller than that from aqueous.