Melting Point Determinations: Mel Temp Operation

Turn the Mel-Temp on and then adjust the heating rate with the heating control.

Higher settings on the heating control dial produce more rapid heating.

Insert the packed capillary into the sample slot.

It is possible to insert up to 3 sample capillaries side by side into the Mel-Temp sample slot at the same time. When measuring several melting points simultaneously be sure to attach small flags to the tops of the capillaries to avoid mixing them up!

Determine a preliminary melting point temperature.

This may not always be necessary since you may know the approximate melting point temperature. But if you don't, why waste precious time going slowly. Instead, adjust the heating control dial so that the temperature increases by approximately 10-20 degrees C per minute. The dial should be in the 40-60 range. Record the approximate melting point temperature range you observe.

Using a freshly packed capillary tube, carefully determine the melting point of the second sample.

Using the heat control dial, quickly heat the sample to within approximately 20 degrees of the melting point you determined in the preceding step. Now reduce the heat setting so that the temperature changes by no more than 2 degrees per minute. Be aware that changes to the heat control dial do not instantaneously affect the temperature. With practice you will be able to anticipate just when to reduce the dial setting for the best results.