The formulae needed for computations on buffered systems are given. Using these formulae, a computer program was evaluated and calculations were correlated with the results of some experiments. The possibility of the simultaneous separation of cations depends on the differences between the effective mobilities, which can be affected by the choice of pH, counter-ion and solvent. The qualitative simultaneous separation of cations was studied in eight electrolyte systems using methanol and water as solvents. In each system, simultaneous separations of 7–10 cations were possible, which could be increased by combining electrolyte systems.