Lab and analysis
Karl Fischer titration (water content)
Definition
A specific titration method for measuring water content, from percentage levels down to parts per million.
Karl Fischer titration reacts water with iodine in a defined reagent system. Volumetric KF suits higher water levels and coulometric KF measures very low levels in dry solvents and APIs.
Unlike loss on drying, KF measures water only, not other volatiles, so it is the preferred method when water content matters, such as for hygroscopic materials and anhydrous solvents.