Differential Scanning Calorimetry (DSC) is the most widely used thermal analysis technique. A well-established application is the purity determination of organic substances. The method is based on the van’t Hoff law of melting point depression of eutectic systems. Purities between 90 and 100 mol% can be reliably determined.
Purity determination is used in the chemical and pharmaceutical industries and also for additives in the food and plastics industries.
In this Webinar, we will discuss the basic principles of DSC purity determination and present some interesting applications.
DSC purity analysis of substances in drugs or foodstuffs is an important issue. In general, substances with significant amounts of impurity may produce unexpected reactions, lose their efficiency, or create toxic compounds. In the worst case, even just a few percent of an impurity could be toxic or even lethal.
According to the International Union of Pure and Applied Chemistry,
“A sample is sufficiently pure when the amount of each of the impurities which may interfere with the specific purpose for which the sample is required is so low that their combined effect is negligible within the desired limits of accuracy”.
The amount and nature of impurities in a substance is usually expressed as a percentage or in mole percent.
Purity determination by DSC is based on the thermodynamics of an ideal eutectic system. This can be shown in the form of a phase diagram, explained in this webinar. Many mixtures of organic substances exhibit this type of behavior.