SOP for Operation and Calibration of Karl Fischer Apparatus

OBJECTIVE

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

SCOPE

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

RESPONSIBILITY

Execution: Chemist and above – QC department.

Checking: Asst. Manager and above – QC department

OPERATIONAL PROCEDURE

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 endpoint 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

• The 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 mentioned in the specific monograph.

• Enter the sample quantity and calculate the moisture content by using the following formula

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CALIBRATION PROCEDURE

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 neutralize 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.

REFERENCE

Nil.

ABBREVIATION

SOP: Standard Operating Procedure

Q.C: Quality control

% : Percentage

RSD: Relative standard Deviation

ml: Milliliter

ANNEXURE

Annexure No. – 1 - Karl Fischer Factor Determination Record

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

REVISION HISTORY

Nil

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