FLUORIDE-SENSITIVE ELECTRODE

摘要

The invention concerns a fluoride-sensitive electrode and the use of said electrode for measuring the fluoride content of water, in particular fluoridated drinking water. A fluoride- sensitive electrode of the invention with a lower cross-sensitivity for hydroxyl ions than known electrodes and which allows more accurate measurement of the fluoride conten t in water with a high pH in particular at low fluoride ion concentrations without the need fo r supplementing the sample water with conditioning additives has a tubular electrode shaft, a lanthanum fluoride crystal which closes one end of the electrode shaft, an internal electrolyte sealed between the lanthanum fluoride crystal and a closure in the electrode shaft, and a conta ct wire that dips into the internal electrolyte, wherein the internal electrolyte has a pH of .gtoreq. 9.0 and a fluoride concentration of .gtoreq. 0.1 M.