Evolved Gas Analysis (EGA)

Evolved Gas Analysis (EGA) is an analysis technique that determines the nature and amount of volatile product or products evolved from a sample subjected to a controlled temperature program. Vapors released from the sample due to processes such as evaporation, decomposition o r outgassing of inclusions during thermal treatment are immediately transferred through an interface, to the evolved gas analysis (EGA) system. The EGA system can utilize a variety of  instrumentation such as Fourier Transform Infrared spectroscopy (FTIR), Mass Spectrometry (MS) or combination of MS with gas chromatography (GC-MS). Simultaneous thermal analysis using techniques such as  TGA (thermogravimetry) or DSC (differential scanning calorimetry), can also be done, coupled with a fast Quadrupole Mass Spectrometer (QMS). This enables identification of the evolved gas components and real time correlation with the other thermal analysis parameters. In case directly coupled EGA systems are not available, then, the evolved gasses can suitably be captured, for example, in an adsorbent followed by thermal desorption for off-line analysis.

EGA is widely used for polymer/plastics samples that contain a variety of additives, such as flame retardants, fillers, plasticizers, coloring matters, and antioxidants. The EGA technique has also been applied to other materials including chemical, pharmaceuticals, biomass, and various organic and inorganic compounds.

Video 01: Versatile options with Evolved Gas Analysis (EGA)

Common Uses of Evolved Gas Analysis (EGA)

• Compositional and mass balance analysis
• Aging and decomposition processes
• Desorption behavior
• Study of evaporation and volatilization processes

 Advantages of Evolved Gas Analysis (EGA)

• Compositional, mass balance and calorimetric information can be measured real-time.  
• Low sample quantity.
• Wide heating temperature range and variety of materials can be analyzed
• Qualitative and quantitative analysis possible

Limitations of Evolved Gas Analysis (EGA)

• Samples must be vacuum compatible
• Complicated for unstable materials
• Mostly used for lower molecular weight gasses/vapors.

 Industrial Applications of Evolved Gas Analysis (EGA)

• Plastics, Polymers, Rubber
• Coatings and Adhesives
• Pharmaceuticals
• Chemicals
• Semiconductors
• Petroleum
• Food
• Biomass
• Environmental