Improvement of the upper limit of the ISE Nernstian response by tuned galvanostatic polarization

•Anodic polarization is used for improving the upper detection limit of ISE.•Polarization vs. current dependence obeys the Ohm’s law.•For a Cd2+ISE used as a model system the obtained upper detection limit is 1.0 M.•Simple algorithm allows for the analytical application of the approach.

Galvanostatic polarization with a tuned anodic current density is successfully applied for the improvement of the upper detection limit (UDL) of a Cd2+-selective electrode with PVC membrane containing neutral ionophore N,N,N′,N′-tetradodecyl-3,6-dioxaoctanedithioamide (ETH 5435). The UDL of the anodically polarized electrode is 1.0 M CdCl2 whereas the traditional zero-current UDL is 0.05 M. The polarization regularities obey the Ohm’s law, and this makes the basis for the algorithm of the optimization of the polarizing current density for a given Cd2+ concentration and for the analytical application of the electrode.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide