Standard Operating Procedure (SOP) for Operation and Calibration of Melting Point Apparatus used for analysis / identification of starting materials (Raw Material – API & Excipient) in Quality Control Laboratory.
Operation and Calibration of Melting Point Apparatus
1.0 PURPOSE:
- The purpose of this SOP is to describe the procedure for operation, calibration and maintenance of Melting Point Apparatus.
2.0 SCOPE:
- This SOP is applicable to the following Melting point apparatus at Quality Control Department in pharmaceutical for Make : Polmon and Model MP-96.
3.0 REFERENCES – SOP FOR MELTING POINT APPARATUS:
- Operation Manual supplied by the manufacturer
- SOP for Maintenance of Laboratory Instruments
- SOP for Preparation of internal and external (Third Party) Calibration schedule and calibration practices
4.0 RESPONSIBILITY – SOP FOR MELTING POINT APPARATUS:
- Analyst shall be responsible for:
- To operate the instrument as per the SOP.
- Calibrate the instrument as per the SOP.
- To carry out the documentation as per the SOP.
- Quality Control Head or Designee shall be responsible for :
- To approve the calibration of instrument verifying against SOP.
- To provide training to all the concerned persons before implementing the SOP.
- Execute the out of calibration in case of calibration failure and in case of breakdown, intimate to Quality Head.
- To ensure the operation and calibration of the instrument is carried out as per the SOP.
- To ensure proper documentation as per the SOP.
- Quality Assurance shall be responsible for:
- To ensure the implementation of the system as per the SOP.
5.0 PROCEDURE – MELTING POINT APPARATUS:
- General Procedure for handling of Melting Point Apparatus
- Follow the SOP on Instrument/Equipment usage log book, for the entry of usage of the instrument.
- In case of any maintenance of instrument, follow SOP on Maintenance of Laboratory Instrument.
- Maintain the third party calibration schedule and the internal calibration schedule for the instrument as per SOP, Preparation of internal and external (Third Party) calibration schedule and calibration practices.
- Operational procedure
- Check the calibration status of the instrument.
- Switch ON power supply by switching on the main supply and switch provided on backside of the instrument.
- Press the “FUNCTION” Key to set initial temperature. The “INI TEMP” LED blinks and parameter is displayed in the display.
- Use “↑ ” or “ ↓ “ keys to set the initial temperature.
- Set the initial temperature to 10°C below the expected melting point and the initial temperature should be (15 – 25 )°C above the bath temperature to overcome undershoot or overshoot of temperature, the maximum melting range for the operation of the instrument is 350°C.
- Press the “FUNCTION” key to set “°C/min”, “°C/min” LED blinks and the parameter is displayed in the display.
- Use “↑” or “↓” keys to set the rate of heating.
- Press “FUNCTION” key. The bath temperature is displayed.
- Press “START” key. The “INI TEMP” and “°C/min” LED blinks one after another displaying the corresponding setting with an interval of 2.5 sec.
NOTE: Be sure about the settings (initial temperature and °C/min) as they cannot be viewed or changed while heating process is ON.
- Press “START” key. The oil bath temperature is raised to the initial During this period “INI TEMP” LED glows continuously and “HEATER” LED glows continuously or blinks.
- Insert the capillaries in the bath.
- Press “FUNCTION” key to start Rate of heating (i.e. °C/min). During this period “°C/min” LED glows continuously and “HEATER” LED blinks.
- Watch the sample through magnifying lens.
- Press “STORE” key at the beginning of Melting point, “T1” LED glows continuously indicating that initial melting temperature is stored.
- Press “STORE” key again to store final melting point. “T2” LED glows continuously indicating that final melting point temperature is stored.
- To view initial and final melting point temperatures press “STORE” key to view initial melting point temperature, “T1” blinks to indicate that the displayed temperature is initial melting point.
- Press “STORE” key again to view final melting point temperature, “T2” LED blinks to indicate that the displayed temperature is final melting point
- Calibration Procedure of Melting Point Apparatus
- Calibrate by using Melting Point reference standard.
- Calibration Frequency: Monthly ± 3 days.
- The four Melting Point standards Vanillin, Caffeine, Acetanilide and Sulfanilamide shall be used.
- Reduce the reference standard to very fine powder.
- Treat the reference standards as given below:
- Vanillin: Do not dry.
- Caffeine: Dry portion over silica gel for 16 hours.
- Sulfanilamide: Dry portion over silica gel for 16 hours.
- Acetanilide: Dry portion over silica gel for 16 hours.
- Charge the capillary, one end of which is sealed with sufficient quantity of reference standard to form a column in the bottom of the tube 2.5 mm to 3.5 mm height when packed down as closely as possible by moderate tapping on a solid surface. Surface. (There should not be gap in the column).
- Heat the block until the temperature is about 10°C below the expected melting point and continue heating at a rate of temperature increase of about 1° C per minute.
- Insert the capillary tube in the melting point apparatus when the temperature is about 5° C below the lower limit of the expected melting range and continue heating until melting is complete.
- Follow the above steps given in the procedure part.
- Note the melting point of the reference substance.
- Record the same in the calibration record.
6.0 ANNEXURES – MELTING POINT APPARATUS:
Annexure -1 : Format for Calibration Record of Melting Point Apparatus
| Instrument Name | Melting Point Apparatus | ||
| Instrument Code | Make/Model | ||
| Location | Calibration frequency | Monthly ± 3 days | |
| Calibration Date | Next Calibration due on |
Procedure
- Reduce the standard to very fine powder or as recommended on the label of respective reference standard.
- Treat the reference standards accordingly.
- Charge the capillary, one end of which is sealed with sufficient quantity of reference standard to form a column in the bottom of the tube 2.5 mm to 3.5 mm height when packed down as closely as possible by moderate tapping on a solid surface. (There should not be gap in the column.)
- Heat the block until the temperature is about 10° C below the expected melting point and continue heating at a rate of temperature increase of about 1° C per minute.
- Insert the capillary tube in the melting point apparatus when the temperature is about 5°C below the lower limit of the expected melting range and continue heating until melting is complete.
- Record the temperature at which the last particle passes into the liquid phase.
- Remove the capillary tubes care fully and dispose it off after cooling.
Observation Table:
| Sr.No. | Melting Point Standard | Calibration Standard No. | Observed Melting Range | Limit |
| 1 | Vanillin | 81°C to 83°C | ||
| 2 | Acetanilide | 112°C to 115°C | ||
| 3 | Sulfanilamide | 163°C to166°C | ||
| 4 | caffeine | 235°C to 239°C |
Remarks : The instrument is calibrated & qualified / Out of calibration & not qualified for use.
| Calibration : Scheduled / Not scheduled ( Reason : ______________________ |
Annexure -2 : Format for Calibration Status label
| CALIBRATION STATUS |
| Instrument : ___________________________ ___________ Code : ___________________ Model: ______________________ Frequency______________________________________________ Done on : ____________________________ Due on :____________ Status : Instrument found satisfactory for analytical use Done By : __________________________ Checked By : __________ Date : ___________________________ Date : ________________ |