Concentration profiles of electrochemically generated species are simulated in a channel flow cell containing two electrodes, where a species produced upstream at the generator electrode is detected downstream by the collector electrode. The model is extended for simulation of the currents produced at each electrode when a homogeneous reaction takes place involving the species produced at the generator. For specific cell dimensions and homogeneous mechanism there is a maximum rate constant for the homogeneous reaction that can be measured using the double electrode system, which is a function of the flow rate, the cell geometry and the relative concentrations of the species initially present. The results presented function as a guide to selecting suitable cell geometries and experimental parameters in order to measure homogeneous kinetics using the double channel electrode. (C) 2004 Elsevier B.V. All rights reserved.