A magnetic field perpendicular to the surface of a plane electrode creates convective effects that are analyzed through stationary and dynamic investigations. These effects are enhanced when the species involved is paramagnetic. The magnetic force that acts on the gradient of the electroactive species is highlighted. The diffusion limiting current can be expressed as a function of the induced velocity gradient. By modulation of the magnetic field, a magnetohydrodynamic transfer function can be obtained that allows the diffusion limiting current dependence on both the gradient concentration species and the magnetic field amplitude to be confirmed. (C) 2004 Elsevier B.V. All rights reserved.