9
6.3 Sample Preparation
For accurate melting point determinations the substance being tested should be in a dry and uniformly
powdered form. Coarse crystalline and non-homogeneous samples should be crushed into a fine
powder using a pestle and mortar before the substance is introduced into a capillary tube.
Each capillary tube in a melting point determination should be prepared in the same way. The open
end of a capillary tube is pressed gently into a small amount of powdered substance until the capillary
contains sufficient material to form a compact layer of 2-4 mm in height. The powder is then forced
to the bottom of the tube by repeatedly tapping the bottom of the capillary against a hard surface.
Excessive amounts of sample in the capillary tubes will result in inaccurate melting point
determinations.
The
MP-800D
can accommodate up to three sample capillaries. For accurate melting point
determinations it is recommended that three samples of the same material are prepared in the same
way and analysed at the same time. The average of the three capillaries can then be reported as the
melting point.
7. Operation
7.1 Power up
❖
Connect the mains power cable to the instrument and the plug to the mains power supply.
❖
Turn on the power to the instrument using the mains On/Off switch. The instrument will power
up.
Power up screen
