Mettler Toledo has launched a new online resource for chemical industry laboratories that focuses on features and benefits of the company’s technology solutions and includes a free downloadable tips and tricks booklet.
Melting Point Determination is a common task in chemical laboratories to test the purity and characteristics of substances. The melting point is defined as the temperature at which a solid becomes a liquid at standard atmospheric pressure. While the measurement principle is straightforward, there are quite a few things that can simplify operator work and ensure better results. Below are a few tips and tricks that will greatly improve melting point determination.
Among the tips and tricks detailed in the new resource:
- Make sure the heating rate is at 1°C per minute; most measuring errors come from too high heating rates. Tip to save time: If testing an unknown sample with a high melting point, it is suggested to run a pre-test with higher heating rates, to get a rough idea of the melting point.
- Be sure to grind the sample to a very fine powder and pack it into the capillary without leaving air pockets. Too large pieces and loose packing will result in inefficient heat transfer – and faulty results.
- Do not overfill or underfill the capillary tube to avoid wrong results. The ideal filling height of the capillary tubes is normally specified by the producer of your instrument. Too large samples will result in a too wide or too high MP range; too small samples might make it impossible to observe the MP range. Mettler Toledo has developed a simple mechanism to always check if capillary tubes are filled properly.
To learn other techniques, operators can visit www.mt.com/ChemLab.