Abstract: Electroanalysis of an electroactive, and especially ionized, species, in trace form, in a liquid sample, is by potentiometry with coulometric stripping (elution), and is by employing a working electrode in electrical contact with the sample. A practically exhaustive electrolysis, or a practically exhaustive complexing with adsorption, of the electroactive species, a main coulometric stripping and at least two poststripping cycles including a post-electrolysis step and a poststripping step are performed in succession. By a particular choice of the operating parameters and of the measured parameters it is possible to determine automatically the equivalent mean chemical current, for example for oxidation, competing with the current applied to the working electrode, during the stripping stage. This is done directly from the liquid sample which is being analyzed. As a result, the required concentration of the species is determined without previous calibration.