Determination of Ca2+ ions with a selective electrode (potentiometry)
How it works
The membrane of the electrode contains a reagent that almost selectively complexes calcium ions (ionophore). This is often referred to as BBTP.
When the membrane comes into contact with an aqueous solution containing Ca2+ ions, a potential difference arises at the solution-membrane interface.
![Illustration of the solution - membrane interface. The Ca2+ ions pass from the solution to be analyzed to the PVC + complexing member and vice versa.](/resources/images/fiches/aliments/analyse-eau/en/eau25bis.png)