In the initial step we have tested tetramethylammonium chloride (TMA) as a model ionophore. Figure shows the results of TMA ion transfer (25-250 µM) across the water/DCE interface measured using the cyclic voltammetry and differential pulse voltammetry techniques. Results obtained in the miniaturized setup were comparable to the ones from the standard cell. The ion transfer potential was the same for TMA in both cells. The transfer current was ten times lower due to the smaller interface area. The increase of the ion transfer current is linearly proportional to the TMA concentration in the aqueous solution (R 2 CV = 0.95, R 2 DPV = 0.98). Similar relation was observed for ion transfer across the liquid/liquid interface studied with the DPV technique.