When using a copper working electrode to study the diffusion of Cu( II) ions it is necessary to polish the electrode between experiments to maintain a smooth surface. To eliminate the required polishing, a platinum working electrode can be used. The copper layer established on the electrode surface during experimentation can be removed between experiments by anodic stripping. When using a platinum disk working electrode, the most reliable method of analysis involves double potential step chrono- amperometry method as opposed to voltammetry. By applying this method diffusion coefficients for Cu( II) ions in sulphuric acid - aqueous and methanesulfonic acid ( HMSA) methanol solutions were determined.