LimsPulse
Titration & electrochemistry

Karl Fischer Titrator (Coulometric)

Measures very small amounts of water by generating iodine electrically inside the cell and counting the charge needed to react with all the water. Suited to trace water, from ppm levels up to about 1–5%.

  • Pharmaceutical
  • Biotech
  • Chemicals
  • Petrochemicals
  • Electronics / batteries
Illustration of Karl Fischer Titrator (Coulometric)
Follow your site SOP
This is a typical operating sequence for learning. Your instrument model and approved SOP take precedence.
STAGE 1

Before you start

  1. 1Check the instrument is within its calibration due date.
  2. 2Check the anolyte (and catholyte, if used) is within its capacity and not discoloured.
  3. 3Check the molecular sieve in the drying tubes and the condition of the septum.
  4. 4Prepare dry syringes and needles for liquid samples.
  • KF reagents contain methanol or other toxic solvents: handle them in a fume hood with gloves and eye protection.
STAGE 2

Conditioning and drift

  1. 1Start conditioning and let the instrument dry the anolyte.
  2. 2Wait until the drift is low and stable (commonly below about 10 µg/min, or the limit in your SOP).
  3. 3Record the drift before the first determination.
  • A rising drift after fresh reagent is filled usually means a leak or wet glassware. Do not start samples until it is stable.
STAGE 3

System check

  1. 1Inject a certified water standard (for example 1.0 mg/g or 0.1 mg/g) by weight and check the recovery against the certificate.
  2. 2Run the check at the frequency in your SOP, usually daily or before each series.
STAGE 4

Sample analysis

  1. 1Rinse the syringe with sample, draw up the sample and weigh the filled syringe.
  2. 2Inject through the septum below the liquid surface without touching the electrodes, then reweigh the syringe.
  3. 3Enter the injected mass and start the determination.
  4. 4Choose a sample size that contains roughly 100 µg to 5 mg of water for good precision.
  5. 5Run replicates as required by the method.
  • Do not inject more water than the reagent can handle; check the remaining capacity in the software.
  • Wipe the needle tip before injecting so no external moisture is introduced.
STAGE 5

Shutdown

  1. 1Leave the cell in standby so it stays dry, or empty and clean it as per SOP if it will not be used for a long time.
  2. 2Dispose of spent reagent in the labelled KF waste container.
  3. 3Complete the instrument usage log.
In LimsPulse · Calibration Management

Keep every KF titrator (coulometric) in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

See how