The influence of the conditioning procedure on potentiometric characteristics of solid contact calcium-selective electrodes in nanomolar concentration solutions

A solid contact calcium-selective electrode with a poly(pyrrole) intermediate layer doped with the calcium ion-complexing ligand Tiron was successfully constructed and examined towards the possibility of lowering the detection limit. Two calcium ionophores, ETH 1001 and ETH 129, were compared. A variety of different shapes of potentiometric responses can be obtained in a controlled manner by applying an appropriate conditioning procedure. The lifetime of the investigated electrodes was longer than 1 year. The modified poly(pyrrole) solid contact electrode was compared with the coated wire type. An inductively coupled plasma mass spectrometry with laser ablation analysis (LA ICP MS) was used to confirm the transmembrane ion fluxes.