Sop for Operation and Calibration of Karl Fischer titrator
This Document describes (Standard Operating procedure) Sop for Operation and Calibration of Karl Fischer titrator
Sop for Operation, cleaning and Calibration of Karl Fischer titrator .
I. Purpose & Scope:
- The Purpose of this SOP is to lay down the procedure to lay down a procedure for Operation, Cleaning & Calibration of Karl Fischer titrator.
- This procedure is applicable for Operation, cleaning & Calibration of Karl Fischer titrator used in Quality Control Department
II. Responsibilities:
- All Quality Control personnel’s shall be responsible to follow and implement this SOP.
III : Introduction and Procedural Part :
IV) GENERAL CLEANING :
- Clean the Machine with a clean dry cloth every day. Occasionally wet cloth dipped in dilute soap solution may be used.
- Precautions has to be taken to clean the instrument immediately with dry cloth to remove the moisture.
V) SAFETY AND PRECAUTIONS :
- Clean the electrode and store it as per electrode requirement.
- Remove the solutions from burette and tubing after completion of titration.
- Always follows procedure given for connecting and removing burette assembly if not it may break the burette.
VI) BASIC OPERATION:
- Switch on the main power switch and switch on the power switch provided on the rear side of the instrument and connect the electrode and printer to the instrument.
1) Connecting and Removing Burette Assembly:
Press Fill key before connecting and removing burette assembly. Check valve pin position, it should be straight. Adjust piston before connecting burette assembly. Place assembly on mechanism and push towards front side gently. Press ‘FILL’ key and check piston up and down movements. If it is ok then assembly is connected properly.
2) Rinsing and Filling Burette:
- After connecting the burette assembly, rinse the burette by the titrant as follows.
- Keep the reagent bottle on the burette assembly and Put the filling tube in solution and dispense tube in waste beaker. (To avoid the wastage of solution keep the tip of the dispense tube in reagent bottle.)
- Select rinsing function through ‘Aux Function’ key and press ‘GO’ key.
- Same way filling of the burette can be done or pressing ‘FILL’ key can fill burette. After filling the burette instrument is ready for titration.
3) Performing the Karl-Fischer Titration:
- Connect the KF Electrode cable and stirrer cable to the titrator and Select the KF method by pressing the method key.
- Select magnetic stirrer from ‘Aux. Function’ key.
- Connect KF burette assembly and rinse the burette with KF reagent.
- Finding out the titer value / factor of KF reagents.(Titer mode).
- Select titer mode by pressing Mode key and then press Enter key.
- Take about 70 ml specially dried methanol for KF titration in titration vessel and put the stirring paddle in it.
- Fix the Silica Gel containing Moisture Trap to the vessel.
- Dip the dosing tube and KF electrode in to the titration vessel and adjust the speed of the stirrer to get the stable and fast stirring.
- Press AUX. FUNCTION key & enter all parameter like DATE, TIME etc and Press MODE key and select mode then, press GO key, titrator will go for Blank runt till End Point is reached The End Point mV will be displayed on the display. Once the End point is reached the titrator will go in Drift.
- Introduce 30 µl of water in titration vessel titration will start.
- Take average of 2 titer values and feed it in sample mode.
- Finding out the water content of the sample. ( sample mode/Blank mode) Select sample mode either using mode key or after completing the titration in the Titer mode, titrator will directly switch over the sample mode.
- Press enter key when titrator is in drift mode and feed the parameters.
- Take the weight of the sample and add it into the vessel.
- At the end of the titration titrator will ask for the holder weight, feed the holder weight press enter key. Display will show ‘REPORT / ENTER / CLEAR’.
- Press REPORT key and press ENTER key, printing of report starts.
- Press CLEAR key, Display—SPECTRALAB KARL FISCHER.
- Rinse the burette and tubing with methanol after completion of titration.
VII) CALIBRATION OF KARL FISCHER TITRATOR :
1) Calibration by Disodium Tartarate :
- Select sample mode either using mode key or after completing the titration in the titer mode, titrator will directly switch over the sample mode and Press enter key when titrator is in drift mode and feed the parameters.
- Take the accurately about 200 mg of Disodium Tartrate into titration vessel and close the titration vessel immediately with stopper during calibration of Karl Fischer titrator.
- Feed weight in g with the help of numerical keys of key board and press “ENTER”.
- At the end of the titration titrator will ask for the holder weight, feed the holder weight press enter key. Display will show ‘REPORT / ENTER / CLEAR’. Press REPORT key and press ENTER key, printing of report starts. Press CLEAR key, Display— SPECTRALAB KARL FISCHER.
- Repeat the operation again for second determination.
- The water content of Disodium Tartrate should be about 15.66% w/w.
- The Acceptance criteria for the water content of Disodium Tartrate shall be ± 2 %.
- Discard used reagent and preserve the electrode in methanol.
- Switch off the instrument and record all observations in calibration record as per Annexure I.
- Titer determination print-outs shall be filed in the separate file after putting signature and date of analyst and reviewer during calibration of Karl Fischer titrator.
If any discrepancy observed during operating and calibration of Karl Fischer titrator instrument report to QC Manager & notify the defect to Maintenance Manager to rectify the defect. Affix ‘Under Maintenance Label’ on the instrument.
2) Calibration of burette Dosing:
- Set the drift value of the dosing at minimum through the knob given in front of the instrument.
- Start the dosing by pressing the Dose Button on the front panel of the instrument for 10 ml and 20 ml separately.
- Collect the dispensed volume in a empty beaker. Determine the dispensed volume in ml as follows.
- Dispensed Volume = (Wt. of the beaker + Water) – Wt. of beaker
3) Determination of Density of water:
Take a 10 ml of water by using pipette (grade A) and weigh on analytical balance. Determine the density of water by using following formula.
Weight of water (gm)
Density of water = ——————————— X 0.997
Water taken (ml)
- Calculate the relative error % as follows :
Volume on Display (ml) – Dispensed Volume (ml)
= ——————————————————————– X 100
Volume on Display (ml)
The relative error should not be more than + 0.5%.
- Record the observation in the calibration record as per the Annexure II.
- Electrode sensitivity shall be performed by outside calibration agency on yearly basis.
- Calibration of Karl Fischer titrator Frequency: Once in Month and after each maintains job.
VIII) ANNEXURE:
Annexure I : RECORD OF INSTRUMENT CALIBRATION OF KARL FISCHER TITRATOR
Annexure II : RECORD OF INSTRUMENT CALIBRATION OF KARL FISCHER TITRATOR
ANNEXURE-I
RECORD OF INSTRUMENT CALIBRATION OF KARL FISCHER TITRATOR
| Name of Instrument : Karl-Fischer Titrator | Date of Calibration : |
| Make : | Model : |
| Department: Quality Control | Instrument ID No : |
| Frequency : | |
Calibration of Karl Fischer Titrator :
- A) Cleanliness of the Instrument:
Observation: Clean / Not Clean Date:
Corrective action in the case of non-compliance: Sign:
- Any other maintenance:
Observation: Required / Not required Date:
Corrective action in case of non-compliance: Sign:
| Sr.
No. |
Date | Weight of Sodium Tartarate (mg) | Factor of KF reagent (mg/ml) | Water Content of Disodium Tartarate
|
Average
(%w/w) |
Acceptance Criteria
± 2 % (15.35 – 15.97% w/w) |
| 1 | ||||||
| 2 |
B)
Remark: The instrument is calibrated and Complies / does not comply with the acceptance criteria.
Calibrated By: Checked By: Head QC
Date : Date : Date :
ANNEXURE-II
RECORD OF INSTRUMENT CALIBRATION OF KARL FISCHER TITRATOR
BURETTE DOSING
| Name of Instrument : Karl-Fischer Titrator | Make: |
| Model: | Instrument ID No : |
| Department: Quality Control | Date of Calibration: |
| Frequency : | |
Calibration of burette Dosing:
- A) Cleanliness of the Instrument:
Observation: Clean / Not Clean Date:
Corrective action in the case of non-compliance: Sign:
- Any other maintenance:
Observation: Required / Not required Date:
Corrective action in case of non-compliance: Sign:
- B) Burette Calibration:
Weight of water (gm)
Density of water (d) = ——————————— X 0.997 = ————– X 0.997 = ______
Water taken (ml)
| Burette No. | Dosing Volume | Volume on display (X) | Tare Weight of beaker in gm. (a) | Weight of beaker with water in gm. (b) | Dispensed Volume in ml (Y)
_(b-a)_ 0.997 |
Relative Error
(NMT+ 0.5 %) X – Y ———-x100 X |
| 10 ml | ||||||
| 20 ml | ||||||
| 10 ml | ||||||
| 20 ml |
Calibrated By : Checked By :
Date : Date :
