Operation and Calibration of Autotitrator & K F Titrator

1. Objective

To lay down a procedure for operation and calibration of Autotitrator & KF Titrator. It is used for quantitative determination of assay of raw materials and water by titremetric method.

• Scope

This SOP is applicable for operation and calibration of Autotitrator & K F Titrator (Make: Lab India)in Quality Control Laboratory.  

• Responsibility

QC Chemist / Officer : Follow the procedure and maintain record as applicable.   

• Accountability

Head Quality Control  : System Compliance

• Procedure:  
  • Ensure that equipment is clean.
  • Check the calibration due date.
  • The equipment is used as KF Titrator & as well as Autotitrator (Aqueous & Non aqueous).
  • Set the equipment as required.
  • Operation:
    • Switch on the main electrical point. Switch on switches of Auto Titrator, magnetic stirrer. Auto Titrator screen displays Neutralization 1) Y 2) N, Simultaneously rinse magnetic stirrer, vessel with dry methanol, add 30 ml of methanol in this.
    • Press 2) N Press 2) for function press 2) for function, press 3) for priming Type volume for priming let 3000µl etc. Take out dispenser from holder and press enter. Wait for priming when It  is over fix the dispenser in magnetic stirrer vessel.
    • Press reset, on and adjust the speed of magnetic stirrer. Then press 1) for neutralization. When it is over, it will display result and print simultaneously if printer attached.
    • Now press rest, press 2) N, press 7) run. Then type method no. for determine KF concentration simultaneously add a drop of water (40 mg) in magnetic stirrer vessels press enter, press 1) Run, type idenfication No. e.g. Water etc. press enter, type weight in mg, press enter. Wait. It displays result and then print.
    • Determination of Water in sample: Press escape, press 7 for new run, type identification No. let folic acid 101, press enter. Simultaneously weigh the sample and add in magnetic stirrer vessel. Type the weight of sample and press enter. When determination of water is over result will be displayed on the screen and print automatically. Off the magnetic stirrer. After print out press reset, put out the dispenser and put it in holder. Clean the accessories which require cleaning, and switch off the instrument.
    • To change the KF assembly and replace with aqueous and non aqueous titration Assembly and vice versa: Pressreset, press 2) function, press burette Press 1) for changing assembly. To remove the burette assemblies now remove the screw. Display burette factor, press enter.
  • Operating Procedure of Auto Titrator (Potentiometer):
    • Switch on the main switch and instrument switch, vortex mixer and connect the Accessories LCD of auto titrator displays by blinking various functions after sometime stable with display 1) develop method 2) function.
    • Press 2) function, press 3) for priming, add volume let 5000 µl press enter wait for priming.
    • For sample analysis, press 4) run, 2) for new method no. Identification no. of sample press enter, type weight of sample, press 1) Run, when analysis is complete it displays result on the screen and print automatically. After print out press reset, put out the dispenser and put in the holder. Clean the accessories which require cleaning, and switch off the instrument.
  • Method Development and Changing normality:
    • To change normality / constant / threshold in method:

Develop method (1) Enter                              Full method (2) – Enter

Add/edit method (1) Enter                              method No. – select method

Edit ½ (1) Enter                                              Sample Name – Enter

Titrant name Enter                                        Measurement type – Enter (Potentiometer)

Titrant type Enter (select)                               titration mode – Enter (equilibrium)

Pre dispense criteria – Omv Enter                Pre dispense volume- 80 % E.P volume

Pre dispense dose – 500/100 µl                      Predispense interval – 10 second

Stirrer time -60 seconds                                 Initial dose – 100-200 µl

Equilibrium Factor- 6                                     Volume limit – 120% E.P volume

• To change normality / threshhold / constant, select reprocess (2) threshold  If change required, Enter new value, otherwise proceed; calculate by, Enter normality code  ENTER, conc. / normality for blank 8 , Molarity 12,and % assay 13.
  • Enter the activity in Annexure.
  • Water Factor: Find out the water factor of KF against water every time prior to analyze the sample once in a day and record the entry in instrument log book.
    • Quarterly Calibration:
    • Operate the equipment.
    • Replace the titrant holding bottle with methanol; prime all the three burettes one by one twice with 20000 µl methanol. Then replace methanol bottle with purified water. Prime for twice or thrice time, press 2) function, 3) for priming add volume i.e. 500 µl (0.5 ml) collect the water in the previously weighed volumetric flask, weight it then note the water weight and calculate the volume according to formula =A/0.99602. Where A= volume dispense by burette in grams where 0.99602 is weight per ml of purified water at 25°C, B= measure wt. of water in gram. Repeat the same procedure for 1000 µl (1 ml), 2000 µl (2 ml), 5000 µl (5 ml) and 10000 µl (10 ml) the variation should be within ±2.0%. If the burette does not meet the requirement, paste the out of calibration sticker on the burette. Follow the same procedure for all burettes.
    • Calibration procedure for Karl Fischer (KF) Assembly:
      • Primary Standardization:

For Factor: Weighaccurately 150 mg of Sodium Tartrate & transfer it in to magnetic stirrer vessel, start the stirrer and run the method. Result will be displayed and print automatically. Run the sample in triplicate and calculate the %RSD and it shall not be more than 1.0%.

• Secondary Standardization:

For Moisture Content: Weighaccurately 150 mg of Sodium Tartrate & transfer it in to magnetic stirrer vessel, start the stirrer and run the method. Result will be displayed and print automatically. Run the sample in triplicate and calculate the %RSD and it shall not be more than 1.0%.

• Calibration Procedure of Auto Titrator (Potentiometer) Assembly:
  • Standardization and calibration of electrode:
    • Operate the instrument.
    • Press 2) for function press1) for standardization / calibration Enter password.
    • Remove the  pH electrode from its storage buffer and rinse it with distilled water.
    • Clean the electrode with tissue paper and put the electrode in 7.0 pH buffer.
    • When milli volt get stable, press enter.
    • Now displays require Buffer of pH 0-6.5, remove the pH electrode from 7.0 pH buffer and rinse it with distilled water. Dry the electrode with tissue paper and put the electrode in 4.0and type 4.0 and press enter. When milli volt get stable, press enter.
    • Now displays require Buffer of 7.5-14, remove the pH electrode from 4.0 pH buffer and rinse it with distilled water. Dry the electrode with tissue paper and put the electrode in 10.0 pH and type 10.0, press enter. When milli volt get stable, press enter.         
    • Now the LCD displays calibration over. If the electrode is not working properly the electrode faulty displays on the screen.
    • Enter the details in Annexure.
  • Prepare the calibration tag and affix it on the equipment.
  • Enclose the old calibration tag with the record and don’t throw it.  
  • If the variation is not within the specified tolerance limits:
    • Label the equipment with a tag, “OUT OF CALIBRATION”.
    • Inform the Department Head.
    • Do not use equipment until all errors are rectified. After rectification, again calibrate the equipment & record the observation.
    • Frequency: 3 Months ± 3 days.
• Annexure (S)

NA

• Reference (S)

Manufacturer manual

In-house

• Glossary           

SOP                :  Standard Operating Procedure

QC                  :  Quality Control

QA                   :  Quality Assurance

KF                 :   Karl-Fisher

ml                    :   milliliter

°C                    :   degree Celsius

• Revision History

Rev. No.	Details of changes	Reason for change