Evolved Gas Analysis - FTIR (EGA)

EGA Evolved Gas Analysis FTIR

Evolved Gas Analysis - FTIR (EGA)

The Fourier transform infrared spectroscopy (FTIR) is a technique which is used to obtain an infrared spectrum of absorption, emission, photoconductivity or Raman scattering of a solid, liquid or gas. An FTIR spectrometer simultaneously collects spectral data in a wide spectral range. This confers a significant advantage over a dispersive spectrometer which measures intensity over a narrow range of wavelengths at a time. FTIR has made dispersive infrared spectrometers all but obsolete, opening up new applications of infrared spectroscopy.

The combination of a Linseis Thermal Analyzer with a FTIR is especially interesting in fields such as polymers, chemical and pharmaceutical industry. The coupling is more than the sum of the separate parts. Benefits come from the LINSEIS coupling knowledge and integrated hard- and software concept. For interpretation different libraries are available.

Possible Couplings:

Thermobalance + FTIR Spectrometer in the temperature range from -170°C up to 1750°C

  • L81/I-FTIR Thermo balance + FTIR Spectrometer
  • L81/II-FTIR Thermo balance + FTIR Spectrometer
  • STA PT 1600-FTIR Thermo balance + FTIR Spectrometer
  • STA PT 1000-FTIR Thermo balance + FTIR Spectrometer

Thermo balance with coupling to Nicolet FTIR spectrometer. The coupling is made with a heated capillary.


  • Research balance (different models) with TG or simultaneous TG/DSC or TG/DTA measurement.
  • High precision ThermoFisher Nicolet FTIR spectrometer (different model available).
  • Temperature range -170°C up to + 1750°C Three separate heating zones, at capillary, at TG protection tube and at FTIR measuring cell.
  • Carrier gas with wide range of flow rates. Especially developed JLF-detector with long optical pass length.


Both manufacturers Linseis and ThermoFisher Nicolet are some of the leading companies in their specialized fields. This cooperation guarantees outstanding performance for the combined system.

  • Transfer line is temperature controlled up to a maximum of 250°C.
  • Fast response time through short transfer line.
  • FTIR detector with very high sensitivity and with different wave numbers available.

The following applications can be measured: Outgasing components of burned material (paints etc.) Determination of blenders and additives. Absorption and Desorption processes. Analysis of rubbers and plastics.

    Wave numbers: 7500 cm-1 … 370 cm-1
    Resolution: 1 cm-1
    Heating: Transfer line and adapter
    Material transfer line:  PTFE (exchangeable)
    Couplings: DIL, TMA, STA, TGA, DTA, DSC

      Introduction and application

      Cement is an inorganic, non-metallic material. Together with water it hardens and afterwards it stays also hard under water. Portland cement consists of limestone, clay and/or sand. The additives gypsum, anhydrite etc. influence the setting time of the cement. Impurities in the raw cement cause negative influence on the quality of the cement.

      Analysis using thermogravimetry and FTIR

      The additives can be identified and quantified with thermal analysis. The first step shows the evolved water from the CaSO4 di-hydrate to CaSO4 half-hydrate. The second step is the conversion of the CaSO4 half-hydrate to the CaSO4 anhydrite. The evolved water can also be verified by FTIR analysis. Between 600°C and 750°C the carbonates decomposed so CO2 evolves. The shoulder in the CO2 trace of the FTIR signal is the decomposition of MgCO3.


        The Pulse-Analysis injects a exactly predetermined amount of liquid or gas into the Thermobalance (TGA) or Simultaneous Thermal Analyzer (STA). This enhances the measurement possibilities significantly: the MS or FTIR can now be calibrated. Out gassings can be quantified precisely with this method.