The standard electrochemical cell for ion-transfer voltammetry (Figure ) requires 5-10 mL of each phase as the interface must be positioned between the pairs of counter electrodes and capillaries. The cell can be used to test ion transfer for a series of solutions with different concentrations of one component, e.g. anion, by adding successive volumes to the top aqueous phase and gentle mixing. However, this approach is not recommended because it can lead to the formation of an emulsion. The improper mixing could generate errors as the mass transport to the interface is quite slow. Modification of the bottom organic phase between experiments is also very troublesome.