Cr(III) + phenanthroline complexes were Prepared under different pH and concentration conditions. The presence of hydroxylated species in solution was detected by studying the transference of the complexes through the water-1,2-dichloroethane interface. Voltammetric analysis, which includes variation of I-p and E(p) with pH and concentration and the calculation of the Gibbs energies of transference, enabled the species transferred to be identified. The advantages of this method over visible and UV spectroscopy are also discussed.