SOP on Operation And Calibration Of Karl Fischer Apparatus

Aim: To provide Procedure on Operation And Calibration Of Karl Fischer Apparatus.
Objective: This standard operating procedure explains how to use and calibrate the Karl Fischer apparatus.
Responsibility: Chemist/Executive Q.C. for following this procedure.
Accountability: The Manager of Quality Control is accountable for overall compliance with this SOP.

SOP on Operation And Calibration Of Karl Fischer Apparatus

Procedure: Cleaning

  • After finishing the analysis, empty the KF reagent from the titration flask into the KF waste bottle. Clean the flask by rinsing it with methanol.
  • Wipe the electrode with tissue paper to keep it clean.
  • If needed, use Isopropyl alcohol to clean the outer surface of the instrument. Dry it with tissue paper.
  • Whenever necessary, replace the ‘self-indicating’ coarse silica.
  • If the color of the silica gel changes from blue to pink, regenerate it by heating it in the oven until it turns blue again.
  • Once the KF apparatus is cleaned, document the details in the instrument logbook according to the current SOP version.

Related SOP: SOP for Analysis and Release of Packing Materials


Determining Water Content (Not Easy Soluble Substances):

  • Set the time to 30 seconds.
  • Press ‘Reset’, ‘Run’, and F3 for pre-titration.
  • After, you’ll see a result.
  • Press F3 and input the sample ID.
  • Add sample to the vessel.
  • Input sample weight, then press F3 twice.
  • The machine will print the water content.
  • Sample Size: Choose a sample with 5.00 to 10.00 mg of water.


  • For liquid samples, inject a bit more.
  • Keep syringes and needles clean and dry.
  • Test samples with the lowest moisture first.
  • If moisture is unknown, adjust the sample size.
  • Rinse syringes before using.


  • Neutralize water in methanol.
  • Add 100 mg of sodium tartrate dihydrate.
  • Do titration and record volume.
  • Repeat three times and find the average.
  • The standard value is 6.0.


  • Once a month.

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