Thermogravimetric Analysis (TGA) of materials is commonly used to provide information on the weight loss as a sample is heated or held isothermally. Pharmaceutical materials often show weight losses associated with the loss of solvent/ water, desolvation or decomposition of the sample. This information is then used to assess the purity and stability of the material and its suitability for use. The TGA gives a quantitative measure of mass lost from the sample, but it does not provide information on the nature of the products that are lost from the sample, and this information is often required for complete characterisation.
Coupling a mass spectrometer (MS) to a TGA allows evolved gases to be analysed and identified giving this additional valuable information.
Evolved gas analysis - a high sensitivity study of a solvent of recrystallisation in a pharmaceutical