Navigation menu

Determination of fluoride ions using a selective electrode (potentiometry)

Constitution of the electrode

The crystalline electrodes selective to fluoride ions F- are made up of:

  • A sealed membrane at the bottom of a plastic tube. This membrane is made of a thin layer of lanthanum fluoride monocrystal doped with europium fluoride (II) to enhance its conductivity.
  • An internal reference electrode consisting of a silver wire coated with silver chloride (AgCl).
  • An internal solution of KCl and KF.
Profile diagram of the electrode. The Ag / AgCl reference electrode is immersed in a filling solution (KCl and KF). The membrane at the base is not in direct contact with the electrode.
Next page
Previous page