Amperometry

Amperometry can be distinguished from voltammetry by the parameter being controlled (electrode potential E) and the parameter being measured (electrode current I which is usually a function of time – see chronoamperometry). In a non-stirred solution, a diffusion-limited current is usually measured, which is propor-tional to the concentration of an electroactive analyte. The current is usually faradaic and the applied potential is usually constant. The integral of current with time is the electric charge, which may be related to the amount of substance reacted by Faraday’s laws of electrolysis. The amperometric method provides the ability to distinguish selectively between a number of electroactive species in solution by judicious selection of the applied potential and/or choice of electrode material.