SOP FOR OPERATION & CALIBRATION OF MELTING POINT APPARATUS

1. OBJECTIVE:

1. To lay down the procedure for Operation & Calibration of Melting Point Apparatus.

2. SCOPE: 

1. This procedure is applicable for the Operation & Calibration of Melting Point Apparatus.

3. RESPONSIBILITY:

1. Quality Control Officer / Executive are responsible to follow procedure as per the procedure mentioned in this SOP. 

2. QC Head is responsible for implementation and compliance of the procedure as per this SOP.

4. ABBREVIATIONS

1. SOP    :    Standard Operating Procedure

2. QC    :    Quality Control

5. PROCEDURE: 

1. Procedure For Operation

1. Ensure that the working bench and instrument is clean.

2. Connect the instrument to the mains power.

3. Switch on the instrument.

4. Procedure for date entry

1. Press ‘DATE’ change the date and press ‘ENTER’.

5. Procedure for Program entry.

1. Press ‘ENTER’ then press ‘PROG’ (PROG 1 -20) write program no. and name of the program, press ‘ENTER’.

6. To Delete the Program.

1. Press ‘ENTER’ press ‘PROG’ delete program no. and press ‘ENTER’.

7. Press Function key to set initial temperature.

8. The “INT TEMP” led blinks

1. Set initial temperature.

2. Set the initial temperature by using ↑ or ↓ keys. Set the initial temperature to 10ºC     below the actual melting temperature.

3. Press function key to set ºC/min and set the rate of heating using ↑ or ↓ keys. Again press functions key.

9. Press start key, “INT TEMP” and “0C/min.” LED blinks one after another with an interval of 2.5 sec.

10. Again press starts key to start heating process.

11. The “INT TEMP” LED glows continuously and “HEATER” led blinks continuously.

12. Introduce sample in the capillary tubes such that a 3mm packed column is made.

13. After attaining the initial set temperature of the bath, below the expected melting temperature, insert the capillaries in the bath having sample.

14. Press the function key to start rate of heating. °C/min led glows.

15. Watch the sample through magnifying lens.

16. Press “START” key at the beginning of melting point, “T1” LED glows continuously indicating the initial melting temperature (i.e. T1) is stored.

17. Press “START” key again to store final melting point, LED glows continuously indicating that final melting point temperature is stored.

18. To view initial & final melting point temperature

1. Press “Melting Range Key” key → “T1” blinks and displayed the initial melting point temperature.

2. Press “Melting Range Key” key → “T2” blinks and displayed the final melting point temperature.

3. Press “STORE” key → displayed Temperature in the bath temperature.

19. Record the melting range of the sample as T1 and T2, for melting point record T2.

20. Remove the capillary from the instrument.

21. Switch off the instrument.

2. Procedure For Calibration

1. Operate the instrument as per the SOP for operation of melting point apparatus.

2. Introduce Diphenylamine, Vanillin, sulfanilamide and caffeine in the 3-3 capillary tubes each such that a 3 mm packed column is made.

3. Set the initial temperature by using ↑ or ↓ keys. Set the initial temperature to 10°C below the actual melting temperature of the sample as per table-1. 

4. Note down the temperature at which the sample is melted. 

5. Continue the heating rapidly to increase temperature.

6. Remove the capillary tube after each test.

Table-1

Sample	Melting Point Range
Vanillin	81°C to 83°C
Benzoic Acid	121°C to 123°C
Caffeine	235°C to 238°C

7. Calibration Frequency – Quarterly Put a calibration tag after calibration.

8. If the instrument is out of calibration, tag the instrument with label 

                

9. Inform to the service engineer after rectification. Calibrate the instrument after rectification.

6. ANNEXURES/REFERENCES :

1. Annexure I: Quarterly Calibration of Melting Point Apparatus.