Coulometric Karl Fischer titration with a diaphragm-free cell: Cell design and applications

Coulometric Karl Fischer titration is a useful technique for wide-range water determination, from the percentage level down to trace amounts at the ppm level. Coulometric Karl Fischer titration cells having a current generator with a ceramic diaphragm, separating the anodic and the cathodic compartment, as well as diaphragm-free cells, are commercially available. From an applicative point of view, a diaphragm-free cell for Karl Fischer coulometry is favourable because of its ease-of-use.We have found that improving the design of the diaphragm-free cell may contribute towards its application down to low water amounts. In this contribution, we will illustrate our recent work on optimising a diaphragm-free Karl Fischer cell for application over a wide water determination range, from the percentage level down to trace amounts at the ppm level.