How do I ensure my Karl Fischer cell is dry?

One of the top contributors to wet titration cells is old silica beads and o-rings.

When using a volumetric Karl Fischer Titrator (such as the HI933), it is paramount that you start and end your titration with a dry titration cell. Fresh solvent, new o-rings, new or regenerated silica beads, and Karl Fischer grade solvents are all ways to keep the cell dry (you are creating a closed system). To help dry out the cell:

  1. Use a vacuum pump to empty the titration cell.
  2. Refill the titration cell with fresh Karl Fischer grade solvent to the minimum fill line.
  3. Carefully, without jostling the connections, lift the titration cell and give it a gentle swirl.
    1. This gentle swirling will catch extraneous moisture from the sides of the titration cell.
  4. Place the cell back on the titrator.
  5. If the solvent in the titration cell isn't yellow, manually add around 1 mL of fresh titrant into the titration cell (use the burette menu to do this).
  6. Start pre-titration - the cell should take less than 30 minutes to come to complete dryness.