Calibration Procedure of Auto Titrator (Metrohm)
Make: Metrohm , Model: 905 Titrando
A. Calibration of i-Ecotrode plus and i-Solvotrode electrodes of Auto Titrator:
1. Requirements for Calibration:
- Digital temperature indicator ID No.:_________ Valid upto:___________
- Buffer pH 4.01, ID No.: ______________, Valid up to : ___________
- Buffer pH 7.00, ID No.: ______________, Valid up to : ___________
- Buffer pH 9.00, ID No.: ______________, Valid up to : ___________
- Electrode : i-Ecotrode plus and i-Solvotrode.
2. Procedure:
2.1 i-Ecotrode electrode:
- Insure the instrument is ready for use.
- Adjust the temperature of buffer solution 25.0°C +/- 2.0°C
- Select the method and load the method parameters on 905 Titrando.
- Start the calibration by click on “Start” icon, then one dialog box shall be appear and ask for temperature at which calibration shall be perform.
- Enter the required temperature and kept the electrode in the 4.01 buffer solution.
- Instrument will be automatically display the measured value and ask for next buffer solution.
- Kept the second buffer solution, i.e. 7.00 and follow the same procedure for third buffer solution, i.e. 9.00.
- After completion of above measurement report shall be display automatically.
- Take a printout of the displayed report and compare the results again the acceptance criteria as per table – 1.
2.2 i-Solvotrode electrode :
- Insure the instrument is ready for use.
- Adjust the temperature of buffer solution 25.0°C +/- 2.0°C.
- Select the method and load the method parameters on 905 Titrando.
- Start the calibration by click on “Start” icon, then one dialog box shall be appear and ask for temperature at which calibration shall be perform..
- Enter the required temperature and kept the electrode in the 4.01 buffer solution.
- Instrument will be automatically display the measured value and ask for next buffer solution. Kept the second buffer solution, i.e. 7.00.
- After completion of above measurement report shall be display automatically.
- Take a printout of the displayed report and calculate the mV difference between pH 4.01 and 7.00 (absolute difference).
- Compare the results again the acceptance criteria as per Observation table.
Observation Table :
B. Burette calibration of Auto Titrator:
1. Requirements for Calibration :
- Digital temperature indicator ID No. __________ Valid up to_________
- Milli- Q water : ________________
- Analytical Balance ID No.__________ Valid up to _________
2. Procedure:
- Ensure the instrument is ready for use.
- Burette calibration shall be carry out 1mL, 5mL and 10mL dispensing in triplicate for 10mL burette and 1mL, 10mL and 20mL dispensing in triplicate for 20mL burette
- Take Milli-Q water in the bottle and maintain about 25°C +/- 0.5°C temperature of Milli Q water during the calibration Use Open dosing tube (As per below figure) during burette calibrations
- Fix the inlet of the tube in bottle, to prepare the burette click on “Manual” icon from main screen following screen shall appear.
- Select “Dosing device” then click on “Prepare” then click on “Start” icon.
- To dispense the required volume click on “Manual” icon, from main screen following screen shall be appear.
- Select “Dosing device” then click on “Add fixed volume”. “Fill rate” modify the parameters as per requirement.
- “Dossing rate” and “Filling rate” shall be modify as per requirement.
- Enter the sufficient required volume in “volume” as 1.0 mL.
- Please Keep the dispensing tube outlet in previously weighed glass flask .
- Click on “Start” icon to start the dispensing water (Milli-Q) in flask.
- Please Follow the above procedure points 2.9 to 2.11 by entering the volume 5mL and 10mL for 10mL burette and 1.0 mL, 10.0 mL and 20.0 mL for 20.0 mL glass burette .
- Calculate the “Actual volume” dispense by means of burette, “Difference” and “Absolute error” as per below calculation formula.
- Record the observations and calculate the results then compare the results for its compliance against acceptance criteria in record log.
- Results should be Submitted in the calibration template to designated person for checking.
Acceptance criteria of mean Absolute error : NMT +/- 30µL
Calculation:
Actual Volume of Water:
- Wt. of water / 0.99602 = ——————- / 0.99602 =______________mL
Where,
0.99602 : Density of water at 25°C
Difference:
- |Set volume- Actual volume| = __________ – __________ = _________mL
- Absolute error:
- Difference x 1000 = ___________ x 1000 = ______________µL
Remarks : Satisfactory/ Not Satisfactory
Date of Calibration:
Note:
As per cGMP and cGDP documents should be online filled and should be checked and performed by Qualified Persons only.
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