SOP for Operation and Calibration of Karl Fischer Apparatus

To lay down the procedure for the operation and calibration of the Karl Fischer Apparatus for better and error-free use.

This procedure is applicable for Karl Fischer Apparatus installed in Quality Control Department at XYZ Limited.

Execution: Chemist and above – QC department.
Checking: Asst. Manager and above – QC department

Karl Fischer titration shall be carried out in three stages.

To neutralize blank moisture from methanol
  • Neutralize the blank moisture from methanol and confirm the end point 3-4 times and observe the final reading, which should be about 0.1ml. This indicates that the instrument has stabilized and is ready for standardization of KF reagent.

Factor Determination
  • Factor of KF reagent shall be determined by using water.
  • KF Factor shall be determined three times and the average of the three values shall be obtained. KF factor shall be considered valid if % RSD for the three determinations is less than 1.0%.
  • KF factor shall be determined before use and the records maintained as per Annexure-1.
  • KF factor should be between 4.0mg/ml to 7.0mg/ml otherwise discard the KF reagent.
  • KF factor shall be determined as follows

Determination of Water content.
  • Select the sample size as per the following table or otherwise mention in the specific monograph.
  • Enter the sample quantity and calculate the moisture content by using the following formula

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Frequency: Once in 3 months
  • Operate the instrument as described above in the operation procedure.

Accuracy of Instrument
  • Carry out titration as per 1st stage and neutralized the blank moisture from methanol
  • Add water and note down the KF reagent reading.
  • Repeat the procedure three times and record the results in Annexure-2

Accuracy of the Dispensing Pump
  • Fill the dispenser with the purified water and remove all the air bubbles.
  • Take the weight of the empty 10ml volumetric flask (W1).
  • Connect the outlet of the dispenser to a 10ml empty volumetric flask
  • Press the “CLEAR” key, and the instrument is now ready for validation of volume displacement. Press “ENTER” for Validation
  • Enter volume 10ml and press ENTER.
  • Take the weight of the volumetric flask with water (W2) and calculate the dispensed volume as below
  • Repeat the procedure three times and record the results in Annexure-2.


SOP : Standard Operating Procedure
Q.C Quality control
% Percentage
RSD Relative standard Deviation
ml Milliliter

Annexure No. – 1 - Karl Fischer Factor Determination Record
Annexure No. – 2 - Calibration Record of Karl Fischer Apparatus


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