CALIBRATION OF ACCURACY, PRECISION, LINEARITY AND SYSTEM SUITABILITY OF TOC ANALYZER

• PROCEDURE:

• Preparation of 250 ppb Sucrose Standard solution:
• Clean the glassware used for the preparation of standard solution (250ppb) and rinse them 2-3 times with low organic carbon water.
• Weigh dried sucrose approx. 0.118 +/- 0.0001g and record the value.
• Verify the water used for solution preparation contains less than 100 ppb TC and IC.
• Dilute the weighed sucrose with 1000 ml of TOC water and cover the flask with stopper.
• Calculate the carbon concentration of stock solution as below:

Conc. of Stock (ppb) = Weight of sucrose (g) X Carbon content X 1000000

Carbon content (approx.) = 0.421 (actual theoretical value of assay as per manufacture of sucrose)

• Pipette 5 ml of stock solution and dilute it in to the 1000 ml flask.
• Calculate the final concentration of dilute solution as below:

Conc. Of dilute standard (ppm)= Conc. Of stock (ppm) X Dilution factor (0.05)

• Preparation of 500 ppb Sucrose solution:
• Clean the glassware used for the preparation of Sucrose standard solution (500 ppb) and rinse them 2-3 times with low organic carbon water.
• Pipette 10 ml of stock solution and dilute to 1000 ml with low TOC water.
• Calculate the final concentration of dilute solution as below:

Conc. Of dilute Standard (ppm) = Conc. Of Stock (ppm) X Dilution factor (0.01)

• Preparation of 750 ppb Sucrose Standard solution:
• Clean the glassware used for the preparation of Sucrose standard solution (750 ppb) and rinse them 2-3 times with low organic carbon water.
• Pipette 15 ml of stock solution and dilute to 1000 ml with low TOC water.
• Calculate the final concentration of dilute solution as below:

Conc. Of dilute Standard (ppm) = Conc. Of Stock (ppm) X Dilution factor (0.015)

• Procedure for preparation of 500 ppb as 1,4 Benzoquinone Standard:
• Clean the glassware used for the preparation of 1, 4 Benzoquinone Standard solution (500 ppb) and rinse them 2-3 times with low organic carbon water.
• Weigh 0.075 g (approx.) of Benzoquinone and record the value.
• Verify the water used for solution preparation contains less than 100 ppb TC and IC.
• Dilute the weighed Benzoquinone into 1000 ml volumetric flask and make up with low TOC water and cover the flask with stopper.
• Calculate the carbon concentration of stock solution as below:

Conc. Of stock (ppb) = Weight of Benzoquinone (g) X Carbon content X 1000000

• Pipette 10 ml of stock solution and dilute to 1000 ml with low TOC water.
• Calculate the final concentration of dilute solution as below:

Conc. Of dilute Standard (ppm) = Conc. Of Stock (ppm) X Dilution factor (0.01)

• CALIBRATION PROCEDURE:
• The TOC analyzer calibration of system suitability testing shall be carried out at a frequency of every six months.
• The calibration of Accuracy and Linearity shall be performed once in a year.
• The calibration of precision shall be performed once in a year.
• The calibration of accuracy and precision, Linearity and system suitability testing shall be carried out by QC persons and accordingly the results shall be reviewed by the Head – QC.
• Record the Calibration of Accuracy, precision, Linearity and system suitability testing details in the respective Format.
• Acceptance Criteria:
• An error of ± 7 % of the TOC is acceptable for TOC accuracy.
• An error of ± 3 % of the TOC is acceptable for TOC precision.
• Correlation Coefficient (R2) greater than or equal to 0.96 are acceptable (R2≥0.96) for TOC Linearity.
• System suitability should have the response efficiency between 85 % to 115 %.

• ANNEXURES: 

Annexure-I
Calibration Record for TOC Analyzer

Annexure-II
System suitability Record for TOC Analyzer