A three-phase junction system is one of the most commonly used configurations for studying ion transfer processes. For this reason, we performed experiments in this well-known system to verify if DMFc oxidation can be accompanied by the transfer of a highly hydrophilic anion (SO4 2-,F -) across the phase boundary facilitated by the added ionophore. One of the characteristic effects of ion transfer studies in a three-phase junction system is a linear correlation between the logarithm of the concentration of ions in the aqueous phase and the peak potential with the slope of 59 mV per decade for one-electron redox reactions (Eq 3).