Total Decomposition, Malonic Acid

Sample

Malonic acid

Application

Inactive ingredient

Conditions

Measuring cells: DSC820 or TGA850

Pan: Aluminum 100 µl, with pierced lid

Sample preparation: As received, no preparation

DSC measurement: Heating from 30 °C to 300 °C at 20 K/min

TGA measurement: Heating from 30 °C to 300 °C at 20 K/min, blank curve corrected

Atmosphere: Nitrogen, DSC: 50 cm³/min, TGA: 80 cm³/min

Interpretation

After melting at about 137 °C, the substance decomposes to acetic acid vapor in an endothermic process with the liberation of CO₂. This can be seen in the TGA curve as a 100 per cent weight loss as well as in the DSC curve as an endothermic decomposition peak. The displacement of the baseline is a result of the change of mass and is not caused by a change in the specific heat capacity (c_p)

Evaluation

Conclusion

Decomposition can be detected with DSC and TGA by a heat change or a loss of weight. Further investigation of the decomposition products requires the use of combination techniques such as TG-MS or TG-FTIR.

_{Total Decomposition, Malonic Acid | Thermal Analysis Application No. HB846 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals}