Research output: Contribution to journal › Article › peer-review
The bulk resistance of ionophore-based ion-selective electrodes (ISEs) is studied by means of chronopotentiometry and electrochemical impedance using Ca 2+-ISEs with PVC membranes containing ETH 1001 as a model system. It is shown that the membrane bulk resistance is roughly the same within the range of CaCl 2 concentrations from 0.3 to 10 −3 M, and increases significantly when the concentration is decreased to 10 −4 and 10 −5 M, although the potentiometric response of the ISEs is Nernstian in all these solutions. This increase of the resistance when 10 −3 M CaCl 2 is further deleted is larger than the decrease of the resistance when CaCl 2 is replaced with Ca(SCN) 2 and Ca(ClO 4) 2. The results suggest that the non-constancy of the ISE bulk resistance is not caused by co-extraction of CaCl 2 and therefore is not in conflict with the Nernstian behavior of the IESs potentials. The effect is tentatively ascribed to the regularities of water uptake by ISE membranes.
| Original language | English |
|---|---|
| Pages (from-to) | 458-465 |
| Number of pages | 8 |
| Journal | Electrochimica Acta |
| Volume | 259 |
| DOIs | |
| State | Published - 1 Jan 2018 |
ID: 24072737