Publisher Summary Limiting-current density refers to the maximum rate at 100% current efficiency, at which a particular electrode reaction can proceed in the steady state. This rate is determined by the composition and transport properties of the electrolytic solution and by the hydrodynamic condition at the electrode surface. It has been observed that in many cases mass transfer is not the sole cause of unsteady-state limiting currents, observed when a fast current ramp is imposed on an elongated electrode. Major conditions for valid measurement and interpretation of limiting currents include reaction characterized by slow surface kinetics, progress of the electrode position reaction, use of low concentrations of the reacting ionic species in free convection studies. This chapter outlines the underlying principles, discusses the conditions of validity, and highlights some selected applications and basic features of the limiting-current phenomenon. The chapter also illustrates a synopsis of electrochemical mass-transfer theory, to the extent required for analysis of limiting-current conditions. Various complicating factors—migration effects, the choice of appropriate diffusivity values, unsteady-state conditions, current distribution below and at the limiting current, and the effect of formation of rough metallic deposits—in the interpretation of limiting-current measurements are considered.

Mass-Transfer Measurements by the Limiting-Current Technique

Hydrodynamic modulation using vibrating electrodes: Application to electroanalysis

Vibrating wire electrodes—I. Literature review, design and evaluation

Modifications of palladium electrode surfaces produced by periodic potential treatments

The combination of a novel electrode design and a new experimental approach to coulometry permits the analysis of microliter amounts of samples without prior calibration. The technique has been applied to the determination of lead in whole blood standards. The time for one analysis is 4min and the relative precision approximately 5%. The mass detection limit for cadmium is 3 fmol, the lowest mass detection limit hitherto reported for any electroanalytical technique. The measurements are based on the principle of constant current stripping potentiometry. Amalgamated analytes are re-oxidized by a Combination of an applied constant current and spontaneous chemical oxidation. Equations making it possible to apply Coulomb's law are presented.

G. F. Paús

Papers

Ionic mass transfer at horizontals disc electrodes under longitudinal vibration

An experimental study of ionic mass transfer at horizontal ring-disc electrode under longitudinal vibration