Calcium ion-selective electrodes under galvanostatic current control

Ion-selective electrodes (ISEs) are in many respects ideal sensors for use in the analysis of industrial and environmental samples. Thus, in recent years, the advantages that they offer have led to their adoption in a wide range of applications. Ion-selective electrodes offer several significant advantages over other techniques in the field. These are: insensitivity to sample color, viscosity or suspended solids, rapid response to changes in determinant concentration, and possible use in a very wide concentration range. A further advantage of analytical method involving ISE is that they are relatively simple, and cheap to develop, set up and run. One of the possibilities to improve the detection limit of ISE is to control the ion transport through the ion-selective membrane with a galvanostatic current. Passing nanoampere-level direct currents across the membrane can control ion fluxes through the membrane, which can obscure the determination at low concentration level.