Hyphenated Techniques (Evolved Gas Analysis - EGA)
By coupling a Thermobalance (TG, TGA), Simultaneous Thermal Analyzer (STA, TGA-DSC) or Dilatometer (DIL) with a Quadrupole Mass Spectrometer (QMS), it is possible to detect and identify evolved gases in exact time correlation with TGA or STA signals.
The Combination with an FT-IR (Fourier Transform Infrared Spectrometer) has become an absolute must, especially in the polymer-producing, chemical and pharmaceutical industries.
The GC (gas chromatograph) separates gas mixtures based on the differences in component distribution between a stationary phase (e.g., inner coating of a capillary) and a mobile phase (e.g., He). The purge gas rapidly carries away gas components with a low affinity for the stationary phase. Gases with a high affinity for the stationary phase will follow with a significant time delay (“retention time”).