procedure for operation and maintain the Veego make Karl Fischer Apparatus

I.    PURPOSE:
      To provide a procedure for operation and maintain the Veego make Karl Fischer Apparatus.

 II.   SCOPE:
      The procedure is applicable to the Veego make Karl Fischer Apparatus used for analytical purpose in the Quality Control laboratory, 
III.   RESPONSIBILITY:
       It is the responsibility of the Quality Control personnel involved in the operation of  Karl Fischer apparatus to follow the procedure as mentioned in this Standard Operating Procedure. 
IV.    DOCUMENT REFERENCES:
       Sop’s    : Core procedure: Calibration of Equipment
       Form     : Standardization of Karl Fischer solution

V.    OPERATION:
1.0      PRELIMINARY CHECK:

1.1        Check that the instrument and surroundings are clean, if not, clean with a soft cloth duster.

2.0     BASIC OPERATION: 

2. 1      Switch on the instrument
2.2    Check whether the silicagel in the guard tube is blue in colour before filling theburet. If   it is red in colour, change the silicagel.

2.3.    Check whether the silicagel in the buret vent guard tube is blue in colour.  If it is red in  color, change the silicagel.
2.4    Apply silica grease at glass joints
2.5.    Block the pinhole at rubber bellow and press the rubber bellow for filling the buret.
2.6.    Rotate the stopcock half open position
2.7.    Rotate the stirrer knob between 5 to 7
2.8.    Check the delay switch knob.  It should be at 30 seconds.  If not, adjust it to 30 seconds.
2.9.    Press the start button
2.10.    After completion of titration, a siren will be heard.  After the siren is heard, press stop button.
3.0    Sample Weighing for water content determination : 
3.1    Tare the butter paper and weigh the required amount of sample for which water content by K.F is to be estimated (W1).
3.2    Transfer the sample care fully into the vessel.
3.3    Re weigh the butter paper determine , take a print (W2) .
3.4    Weight to be considered for the calculation is W2-W1.

VI.    STANDARDISATION:
KF solution standardisation: In each shift
            K.F reagent commercially available in two types.

1.1    Single solution of   K.F.  Reagent: 
1.2       Take required quantity of K.F.reagent and transfer into the reservoir of the KF apparatus directly.

1.3    Proceed for the factor determination.  

1.4.      Set of A and B solution of K.F.  Reagent :     
1.5    Transfer half of the required quantity of reagent A in a clean and dry reservoir.
1.6    Add same amount of reagent B to the reagent A.         
1.7    Shake well and fix the reservoir in apparatus. 
1.8    Procedure for the KF factor determination.
1.9    Fill the buret with the K.F. reagent with the help of the rubber bellow
1.10    Take about 25 ml of methanol into the titration vessel. Switch on the instrument.  
1.11    Rotate the stopcock to half open position and press the start button.   
1.12    Stop the button when the sound of siren is heard. 
1.13    Note down the buret reading  (I). 
1.1.4    Tare the butter paper and weigh 0.1-0.2 grams  of  disodium tartarate sample (W1).
1.1.5    Transfer care fully into the vessel.
1.1.6    Re weigh the butter paper determine , take a print (W2) .
1.1.7    Weight to be considered for the calculation is W2-W1.
1.15    Switch on the   start   button.  
1.16    Stop the button when the sound of siren is heard. 
1.17    Note down the buret reading  (F).
1.18    Calculate the factor of the K.F. solution with the following equation.

Note: Conduct two trials as mentioned above, If the difference between the two trials is less than  0.05 average the two results and use the average value as factor. If not, conduct two more trials.
VII    CALIBRATION   Schedule: Once in three months

1. Accuracy

1.0    Fill the burette with the K.F. reagent with the help of the rubber bellow
1.1     Take about 30 ml of methanol into the titration vessel. Switch on the instrument.  
1.2    Rotate the stopcock to half open position and press the start button.   
1.3    Stop the button when the sound of siren is heard. 
1.4    Note down the buret reading  (I). 
1.5    Transfer accurately about 0.2 gram of the disodium tartarate into the titration vessel (W).  
1.6    Switch on the start button.  
1.7    Stop the button when the sound of siren is heard. 
1.8    Note down the buret reading  (F).
1.9    Calculate the water content of the test sample by the following formula.

 20.  Carry out the above for 5 times and calculate the %RSD.        
        
Acceptance criteria: The water content should be 14.86 to 16.46%
                       The %RSD should be less than 2.0%.
            
  
           2.0   Linearity 
2.1    Fill the burette with the K.F. reagent with the help of the rubber bellow
2.2    Take about 30 ml of methanol into the titration vessel. Switch on the instrument.  
2.3    Rotate the stopcock to half open position and press the start button.   
2.4    Stop the button when the sound of siren is heard. 
2.5    Note down the buret reading  (I). 
2.6    Transfer accurately about 0.1 gram of the disodium tartarate into the titration vessel (W).  
2.7    Switch on the start button.  
2.8    Stop the button when the sound of siren is heard. 
2.9    Note down the buret reading  (F).
2.10    Take the values of first trial of accuracy for 0.2 grams weight of DST.
2.11    Repeat the above operation with 0.3 grams of DST.
Acceptance criteria: The correlation coefficient should not be less than 0.995.

Karl fischer, silicagel, stopcock, titration, buret reading