| Operation and Calibration Procedure for Karl Fischer Titrimeters (Microprocessor) |
1.0 OBJECTIVE To lay down a procedure for Operation and Calibration Procedure for Karl Fischer Titrimeters (Microprocessor). 2.0 SCOPE This Procedure is applicable for Operation and Calibration Procedure for Karl Fischer Titrimeters (Microprocessor) in Quality Control department. 3.0 RESPONSIBILITY QC – Officer/ Sr. Officer /Executive/Sr. Executive and above. 4.0 ACCOUNTABILITY Head-QC 5.0 PROCEDURE(Operation and Calibration Procedure for Karl Fischer) 5.1 Ensure that the instrument is clean and free from dust. 5.2 Ensure that the KF reagent fill in the KF bottle and methanol fill in titration vessel are sufficient quantity. The operator should be wear gloves in hands when handle the K.F. reagent. 5.3 Ensure that the connection of the Titrator to mains supply are connected, and then mains switch ‘ON’. 5.4 Speeds of magnetic stirrer adjust by given symbol “↑↓” in apparatus by sliding in the titration vessel. Adjust the speed of the magnetic stirrer such that the wired ends of the electrode sensor should not be touching the stirrer. 5.5 After end drain off the titration vessel and dip the electrode in anhydrous methanol, switch off the instrument switch off the mains. 5.6 Titrimeters (Microprocessor)-key function: (Operation and Calibration Procedure for Karl Fischer) 5.6.1 MENU: Pressing this key any time shall interrupt the ongoing process and take the control to the main menu. 5.6.2 ESC: This key is used to return to previous step. 5.6.3 ENT : This key is used to accept any given operation. 5.6.4 CLEAR : This key is used to clear the reading while calibrating for titer/factor of K.F solution 5.6.5 PRINT : This key is used to print result data. 5.6.6 INC : This key is used to toggle the unit on the display between ppm and meq/L during analysis. This key is operable only in the “General” mode of operation. 5.6.7 DEC : This key is used to recalibrate a previously calibrated setup. 5.6.8 0-9 : These keys have 2 functions: • Used to enter numeric values • Used to select menus 5.6.9 ↑(UP): This key is used to increase the speed of the stirrer. A long beep indicates the maximum speed limit of the stirrer. 5.6.10 ↓ (DN): This key is used to decrease the speed of stirrer. A long beep indicates the minimum speed limit of the stirrer. 5.7 OPERATION: (Operation and Calibration Procedure for Karl Fischer) 5.7.1 Titrate: This option is used to determine the titration (sample test) parameters. 5.7.2 Neutral: This option is used to neutralize the methanol. At the end of titration, the display shows the quantity of the K.F. reagent added to neutralize the methanol & two times of 25µl water. 5.7.3 Calibration: This is used for the calibration of Titer(dispenser)/Factor. The titer/factor can be determined by using one of the following options available: • CAL by 25: To calibrate with 25µl of purified water. • CAL by H2O: To calibrate with known weight of purified water. • DST: To calibrate with Disodium Tartrate. 5.7.4 Misc. Set: This option is used for performing the miscellaneous functions like setting of clock, setting of Extraction time, clear and various printing options. 5.8 Neutral: Select the neutralize mode by pressing numeric key ‘2’. The titration begins. 5.8.1 At the end of titration, the display shows the quantity of K.F. Reagent added to neutralize the methanol. This reading is not required as it includes the volume of reagent used for removing the air in the delivery tube and keeps it filled with K.F. reagent. 5.8.2 Now the instrument is ready for further titrations and sample testing or calibration of K.F. reagent as the methanol is now totally moisture free. 5.9 CALIBRATION: (Operation and Calibration Procedure for Karl Fischer) 5.9.1 Cal-25: 5.9.1.1 Select the calibration mode by pressing numeric key ‘3’. 5.9.1.2 This mode is used to find the factor/titer of K.F. reagent by using 25µl of Purified water.1µl of water is considered to weight 1mg. 5.9.1.3 Make sure that the methanol in the titration vessel is moisture free. 5.9.1.4 Fill the 25µl auto pipette with purified water and add to the moisture free methanol. 5.9.1.5 Press ‘ENT’ key, the display shows ‘waiting’ for extraction time and then titration beings. 5.9.1.6 When the end point is reached, add 25µl of water again and press ‘ENT’ key. The titration starts again. 5.9.1.7 Repeat the above steps 2-3 times to calculate the average of titer / factor. 5.9.1.8 If any particular reading is erratic, discard it by pressing ‘DEC’ key. It does not affect the repeated average value. 5.9.1.9 After 2-3 titration press the ‘ENT’. The display shows the calculated and average titer/ factor value. 5.9.1.10 Press ‘ESC’ key to exit from this mode 5.9.1.11 Titer =mg. of sample added/reading in ml. 5.9.2 Cal by H2O: 5.9.2.1 This mode of calibration is used to find the factor/titer of K.F. reagent using known weight of purified water. 5.9.2.2 After 2-3 titrations, press ‘ENT’ key display shows the calculated and average titer/factor value. 5.9.2.3 Press ‘ESC’ key to exit from this mode. 5.9.3 DST: 5.9.3.1 This mode is used to find the factor/titer of K.F. reagent using known weight of Di-sodium Tartrate Dehydrate. 5.9.3.2 Weight about 100-150 mg of the compound. 5.9.3.3 Make sure that the methanol in the titration vessel is moisture free. 5.9.3.4 Enter the amount of weight to be added in the titration vessel in ‘gms’ using numeric keys. 5.9.3.5 Add the same amount of Di-sodium Tartrate Dihydrate in the titration vessel and press ‘ENT’ key. 5.9.3.6 The titration begins after ‘extraction time’ and waits for end time. 5.9.3.7 Repeat the above step 2-3 times to calculate the average of the titer/factor. 5.9.3.8 If any particular reading is erratic, discard it by pressing ‘DEC’ key. It does not affect the repeated average value. 5.9.3.9 After 2-3 titrations, press the ‘ENT’ key. The display shows the calculated and average titer/factor value. 5.9.3.10 Press ‘ESC’ key to exit from this mode. Mg of sample added X 0.1556 Titer/factor =-------------------------------------------- KF reagent used5.10 Dispenser: 5.10.1 In this mode of operation, the volume of K.F. reagent passes through the motorized dispenser can be calibrated 5.10.2 Connect one end of the connecting tube to 10 ml burette and the other end of the tube connecting to the motorized dispenser. 5.10.3 Take 10 ml of K.F reagent in the burette. 5.10.4 Press ‘ENT’ key, the K.F. reagent starts coming out of the burette into the beaker. 5.10.5 When exact 10 ml of K.F. reagent has come out from the burette, press ‘ENT’ key. The display shows ‘Calibration Done’. 5.11 Titrate: 5.11.1 This mode is used to determine the moisture in the sample. 5.11.2 Make sure that the methanol in the titration vessel is moisture free. 5.11.3 Weight the required amount of sample to be added. 5.11.4 Select the type of sample i.e. solid or liquid. 5.11.5 Add the weighted sample into the titration vessel and press ‘ENT’ key. 5.11.6 When all moisture is neutralizing, the instrument confirms the end point with a beep 5.11.7 After the end point reached the display shows: Reagent used(ml): XX.XX PPM: XXXXXX %: XX.XX Mg H2O: XX.XXX 5.12 Acceptance criteria: 5.12.1 K.F. Water factor RSD should not more than 2.0%. 5.12.2 Di-sodium tartrate Dihydrate water should be between 15.36% to 15.98% and % RSD NMT 2.0%. 5.12.3 Calibration records should be maintained in the format as mentioned in XXX. 5.13 Water Factor Determination: 5.13.1 Note: After neutralization, first determine water factor before any sample analysis for use each sample analysis calculation. 5.13.2 Water Factor determination records should be maintained in the format as mentioned in XXX. 5.14 Calibration Frequency: After six months from Di-Sodium tartrate dehydrate Factor. 8.0 ABBREVIATIONS SOP -Standard Operating Procedure No. -Number QA -Quality Assurance QC -Quality control K.F -Karl Fischer DST -Disodium Tartrate µl -Micro liter mg -Milli gram NMT -Not more than RSD -Relative standard Deviation |