In parametric pumping pH becomes a strong parameter If a complexing agent of medium strength is added. Apart from binary systems also ternary metal mixtures can be separated. The separation of ternary systems with one metal component forming stable complexes (copper) and two other metals forming less stable complexes (nickel, zinc, cadmium) develops like that of a binary system. The process leads to a concentration of copper in one solution and the generation of an almost copper-free mixture of the two other metals in the Ether solution. The separation can be enhanced by means of a second step. In systems with two divalent and one trivalent kind of metals a separation of at least one divalent metal from the trivalent one is achieved.