STANDARD OPERATING PROCEDURE Title: CALIBRATION OF MELTING POINT APPARATUS

1. PURPOSE

It is established for the calibration of Melting Point Apparatus.
2. SCOPE
It is applicable to Quality Control Department.
3. RESPONSIBILITY:
1. Quality Control Manager
2. Assistant Manager Quality Control
4. PROCEDUR
Calibration is done with 6 USP reference standards.
Sulphanilamide USP, Sulphapyridine USP, Vanilin USP, Acetophenitidine acetanilide USP and caffeine USP, If the melting points are with in the declared range instrument is O.K. If the melting points are out of the range call the service engineer for calibration.
Calibration of the melting point is done after 6 months.
Sulphanilamide USP 164.9-165.9oC
Sulphapyridine USP 192.7-1930oC
Vanilin USP 81.6-82.0oC
Acetophenitidine USP 134.6-135.5oC
Acetanilide USP 114.4-115.6oC
Caffeine USP 234.0-239.0oC
a) Use a thermometer graduated at not more than 0.5oC intervals provided with immersion mark the range of the thermometer should be 300oC.
b) Capillary tubes of alkali free hard glass, colored at one end with a wall thickness of 0.10-0.15mm and of internal diameter 0.9 to 1.1mm.
c) Dry a small quantity of the finely powdered substance below the melting point at a pressure of 1.5 to 2.5 kpa over anhydrous silica gel for 24 hours.
d) Transfer a sufficient portion to a dry capillary tube to form a compact column 4 to 6 mm in height.When the temperature reaches 10oC below the lowest figure of the range for which substance been examined ,regulate the rise of temperature to about 1oC per minute when this rate has been achieved and the temperature is 5oC below the lowest figure of the range. Insert the capillary tube, the melting range are those points of temperature within which the solid melts.