Chronoamperometry and pulse voltammetry of uncharged species at microelectrodes in the presence of a very low amount of supporting electrolyte

Normal pulse voltammetric waves obtained under conditions of substantial deficiency of supporting electrolyte may have heights identical to those recorded in the presence of an excess of supporting electrolyte. This is due to fast accumulation of ions in the microelectrode neighbourhood. Even such a small amount of electroinactive ions as that which may be adsorbed at the microelectrode surface can significantly speed up the formation of an “excess electrolyte zone”, and correspondingly can lower the total resistance between the electrodes. Solutions of oxygen and ferrocene, and undiluted methanol were taken for the normal pulse and chronoamperometric experiments. The discussion of the experimental results was supported by digital simulation.