Calibration of Refractometer, Purpose :
Calibration of Refractometer, The purpose of this SOP is to describe the operation, calibration and cleaning of Refractometer (Model: Rudolph J257) used for the determination of the refractive index of raw materials in the quality control laboratory at XX Pharmaceuticals Ltd.
Calibration of Refractometer, Scope :
This procedure is applicable to the Refractometer (Model: Rudolph J257), installed in the quality control laboratory of XX Pharmaceuticals Limited.
Definitions/Abbreviation:
[][]Standard Operating Procedure (SOP): A written authorized procedure, which gives instructions for performing operations.
[][]QC: Quality Control.
[][]Refractive index: The refractive index of a medium with reference to air is equal to the ratio of the sine of the angle of incidence of a beam of light in the air to the sign of the angle of refraction of the refracted beam in the given medium.
Responsibilities:
The roles and responsibility is as follows:
Officer/Executive/Sr. Executive, Quality Control
[][]To ensure that this procedure is followed.
[][]To maintain the records properly as per SOP.
Manager, Quality Control
[][]To ensure that this procedure is kept up to date.
[][]To confirm that the SOP is technically sound and reflects the required working practices.
[][]Arrange training on the SOP to all concerned personnel.
[][]To ensure implementation of the SOP after training.
[][]Schedule calibration of the instrument at the defined intervals.
Head of Quality Assurance
[][]Approval of the SOP.
[][]To ensure overall implementation of the SOP.
Procedure:
Precaution(s):
[][]Clean off samples with water and then with methanol or a suitable solvent as soon as the measurement is completed in a way to avoid possible scratching in the prism.
[][]Do not use the strong solvents such as N,N- Dimethylformamide or N,N-Dimethylacetamide, Cresol, Phenols and other tar acids.
[][]Never use any hard or metallic objects on the prism surface (where the sample to be measured is placed) as scratches quickly spoil the definition of the borderline.
[][]Disconnect the power supply before moving or cleaning of the instrument.
[][]When not in use, keep the instrument in a safe place.
[][]Prior to use, user must ensure that equipment is calibrated.
Operating procedure
[][]Check the machine is calibrated.
[][]Plug the instruments into an acceptable power source.
[][]Turn the instrument ON.
[][]Wait about 30 minutes to warm up the Refractometer.
[][]Carefully clean the polished surface of the fixed prism with water and then with methanol and dry before applying a sample.
[][]Place a few drops of sample on the polished face of the lower Measuring prism.
[][]Lower the sample cover.
[][]Select the option “measure when stable”.
[][]Press the “Read” button to obtain the sample reading.
[][]Take print out of the result.
[][]Record the operation in the logbook.
Calibration with Purified water, Carbon Tetra chloride and Toluene:
[][]Plug the instruments into an acceptable power source.
[][]Turn the instrument ON.
[][]Wait about 30 minutes to warm up the Refractometer.
[][]Carefully clean the polished surface of the fixed prism with water and then with methanol and dry before applying a sample.
[][]Determine the refractive index of the purified water, Toluene and Carbon Tetrachloride at 20°C.
[][]Place a few drops of sample on the polished face of the lower Measuring prism.
[][]Lower the sample cover.
[][]Select the option “measure when stable”.
[][]Press the “Read” button to obtain the sample reading.
[][]Take print out of the result.
[][]Compile the result & take approval for the calibration information sheet (Annexure-I).
[][]Affix the label “CALIBRATED” on the instrument if all test results are satisfactory.
[][]If the equipment found out of calibration limit affix “UNDER Maintenance” label and inform the respective supplier.
[][]Calibration frequency: Once in a year.
Cleaning procedure:
[][]After completion of the testing switch off the instrument and switch off the mains.
[][]Clean the prism surface with purified water or alcohol or xylene or a solvent which will remove sample residue.
[][]Finally clean with purified water.
[][]Wipe it with tissue paper.
Annexure:
Annexure-I: Calibration Information Sheet for Refractometer with Water, Carbon Tetrachloride and Toluene
Annexure-II: Logbook for Refractometer