EGA
What Is EGA (Evolved Gas Analysis)?
EGA (Evolved Gas Analysis) is an analytical approach that identifies and tracks gases released from a material as it is heated. EGA is most commonly performed by coupling a thermal technique (typically TGA or a furnace heating program) with a gas-identification detector such as FTIR and/or MS—so you can learn what is coming off, when it comes off, and how much (qualitative or semi-quantitative, project-dependent).
EGA is especially useful for understanding decomposition mechanisms, residual volatiles, outgassing behavior, and thermal stability in polymers, organics, formulated products, and many inorganic systems (project-dependent).
Key advantages
Identifies outgassing species vs temperature/time
Reveals decomposition steps and likely mechanisms
Strong for contamination / residue investigations and process troubleshooting
Complements TGA weight-loss data with chemical identity
What EGA Is Used For
EGA is commonly used to:
Identify residual solvents, moisture, and low-boiling volatiles
Study polymer decomposition and differentiate multi-step degradation
Evaluate additives and formulation components (plasticizers, stabilizers, binders—project-dependent)
Investigate odor/outgassing in plastics, coatings, adhesives, and packaging (project-dependent)
Troubleshoot bubbles, voids, blisters, foaming, or haze caused by gas generation
Support process optimization (drying, curing, bake-out, thermal treatment windows)
Compare good vs bad lots to determine “what changed?”
Why EGA (vs. TGA Alone)?
TGA tells you how much mass is lost as temperature changes—but not necessarily what caused that loss. EGA adds chemical identity, which helps you:
Distinguish water vs solvent vs decomposition products
Separate additive loss from backbone breakdown
Identify unexpected contaminants or process residues
Produce more defensible root-cause conclusions for failures and drift
Common EGA Configurations (Project-Dependent)
TGA-FTIR: excellent for many organic functional groups and condensable species; intuitive interpretation for organics.
TGA-MS: high sensitivity for low-level gases and lighter species; useful when FTIR bands overlap or when sensitivity is critical.
TGA-GC/MS (or thermal desorption GC/MS): best when you need GC separation + MS identification for complex mixtures of evolved species.
We select the most efficient approach based on matrix, target compounds, and temperature range.
Sample Types We Support
EGA is applicable to many materials (project-dependent), including:
Polymers & plastics: pellets, films, molded parts
Elastomers & foams
Adhesives, sealants, and resins
Coatings, inks, and cured films
Battery and electronic materials: binders, separators, coatings (project-dependent)
Powders and composites (handling and safety dependent)
Unknown residues/deposits suspected to outgas or decompose on heating
Best practice: include a reference/control sample for comparisons.
Typical Workflows
Outgassing / Residual Volatiles Check
Best for: bake-out issues, odor, bubbles, storage instability
Heat program designed around your process window
Identify evolved species vs temperature
Summarize likely sources: moisture, solvent, monomer, additive, decomposition
Thermal Decomposition Mechanism Study
Best for: material selection, stability benchmarking
Correlate weight-loss steps (TGA) with evolved gas identity (EGA)
Interpret multi-step breakdown and key temperature thresholds
Comparative Investigation (“What Changed?”)
Best for: supplier change, aging, failures
Run the same program on reference vs suspect
Highlight new/stronger evolved species and shifted onset temperatures
Provide practical conclusions and next-step recommendations
What You Receive
EGA results showing evolved species vs temperature/time (spectra and trend plots, scope-dependent)
TGA context (mass loss and derivative curves) when coupled
Identified species list (confidence notes, project-dependent)
A clear summary answering:
What is evolving
When it evolves
How it differs vs reference
What it likely implies for your process or failure mode
Sample Submission Guidelines
Please provide
Sample description and your goal (outgassing, decomposition, comparison, odor, process troubleshooting)
Expected temperature exposure in use/process (drying, curing, reflow, bake-out, etc.)
Any suspected volatiles (solvents, monomers, additives) and required detection focus
SDS and hazards (especially for unknowns, energetic materials, or powders)
Reference/control sample whenever possible
Typical sample amounts
Solids: often tens of mg (more is helpful for repeats and confirmatory runs)
Films/coatings: several small pieces (clean, representative)
Packaging tips
Seal samples promptly to preserve volatiles
Avoid contamination (gloves, clean containers)
Label reference vs suspect and note storage history
FAQs
Can EGA identify the exact compound name?
Often it can identify functional groups or likely species (especially with MS/GC-MS coupling). Exact identification depends on complexity, overlap, and available reference data (project-dependent).
Is EGA quantitative?
EGA is commonly qualitative or semi-quantitative. If you need absolute quantitation of a specific volatile, targeted GC or GC-MS methods may be recommended.
What’s the difference between EGA and thermal desorption GC-MS?
Both study volatiles released by heating. EGA (TGA-FTIR/MS) emphasizes continuous gas evolution vs temperature, while TD-GC/MS emphasizes separated compound identification with GC.
Is the test destructive?
Yes—the analyzed portion is heated and consumed/altered during analysis.
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