Operation & Calibration of Melting Point Apparatus

SOP

1.0 WHAT

This document details the procedure for the Operation of Melting Point Apparatus

2.0 WHY

It is the policy of the written procedure will be followed for the Operation of Melting Point Apparatus and its use monitored in order to ensure that the operation is carried uniformly by any of the analyst so as to avoid any deviation from the procedure.

3.0 WHEN

This procedure is to be applied at the time of Operation of Melting Point Apparatus

4.0 RESPONSIBILITY

Persons along with their responsibilities are given below:

S. No	Designation	Responsibility
01	Analyst	To prepare the SOP and follow the SOP.
02	Section In Charge	To ensure implementation of SOP.
03	QA In Charge	To ensure implementation of SOP.

5.0 PROCEDURE

5.1 OPERATION

5.1.1 Powder the sample as fine as possible.

5.1.2 Dry it at a temperature if specified in the individual monograph.

5.1.3 Heat the bath until the temperature is about 10 below the expected melting temperature.

5.1.4 Continue the heating and note the temperature at which the column of the sample

collapse definitely against the side of the tube at any point, when melting may be considered to have

begun and note also the temperature at which the sample becomes liquid throughout as seen by the

formation of a definite meniscus.

5.1.5 Record the reading of Melting point.

5.1.6 After observation remove the capillaries/ sample column from oil bath.

5.1.7 After completing the test switch off the instrument properly.

5.2 CLEANING

5.2.1 Clean the instrument with Clean Cloth

5.2.2 Remove the Silicon Oil frequently

5.3 Precaution:

5.3.1 Keep the instrument clean and Dust free.

5.3.2 Do not go to the over limit of temperature as prescribed.

5.3.2 All the knobs are very delicate and should be handled carefully.

6.0 CALIBRATION

6.1 PROCEDURE

6.1.1 Melting point apparatus is calibrated by taking the melting points of vanillin, acetanilide,

sulphanilamide and caffeine anhydrous.

6.1.2 Using the standard calibrated thermometer the temperatures at which the materials start

melting, & at which they completely melt, are read and recorded.

6.1.3 The melting points of these materials should fall within the given limits; then the instrument is

calibrated.

S. No.	SUBSTANCE	LIMITS
1.	Vanillin	81 to 83 Deg. C
2.	Acetanilide	114 to 116 Deg. C
3.	Sulphanilamide	164.5 to 166.5 Deg. C
4.	Anhydrous Caffeine	234 to 237 Deg.C