An electrochemical extraction method comprises establishing a cell of the form working electrode: flowing aqueous electrolyte solution: second electrode. The working electrode includes an ion exchange material and the second electrode may include ion exchange material. D.C. potential is applied to the cell to adsorb ions onto the working electrode and cell polarity is subsequently reversed to elute the adsorbed ions.The cell is separated by a cell divider, e.g. in the form of an ion selective membrane, into first and second electrolyte compartments and the solution is passed through the compartment adjacent the working electrode to effect adsorption and, where the second electrode includes ion exchange material, solution is passed through the compartment adjacent the second electrode to effect desorption.