Hydrodynamic modulation applications to electroanalysis and diffusion coefficient measurement with a commercial disk rotator.

The frequency response of sinusoidal hydrodynamic modulation at a rotating disk electrode has been applied to the determination of the diffusion coefficient (D) of oxygen in an aqueous electrolyte. Previous theory established that this response is dependent only on the frequency of modulation/frequency of rotation ratio and on the Schmidt number, kinematic viscosity/D. The method does not require knowing the number of electrons transferred or the concentration of electroactive species.