Fourier Transform-Infrared Spectroscopy (FTIR)

MEE has FTIR systems for both large and microscopic samples.

Fourier Transform-Infrared Spectroscopy (FTIR) is an analytical technique used to identify organic (and in some cases inorganic) materials. This technique measures the absorption of infrared radiation by the sample material versus wavelength. The infrared absorption bands identify molecular components and structures.

When a material is irradiated with infrared radiation, absorbed IR radiation usually excites molecules into a higher vibrational state. The wavelength of light absorbed by a particular molecule is a function of the energy difference between the at-rest and excited vibrational states. The wavelengths that are absorbed by the sample are characteristic of its molecular structure.

The FTIR spectrometer uses an interferometer to modulate the wavelength from a broadband infrared source. A detector measures the intensity of transmitted or reflected light as a function of its wavelength. The signal obtained from the detector is an interferogram, which must be analyzed with a computer using Fourier transforms to obtain a single-beam infrared spectrum. The FTIR spectra are usually presented as plots of intensity versus wavenumber (in cm-1). Wavenumber is the reciprocal of the wavelength. The intensity can be plotted as the percentage of light transmittance or absorbance at each wavenumber.

Thermo Scientific Nicolet iS50 FTIR Spectrometer
Thermo Scientific Nicolet iN10 FT-IR Microscope

Typical Applications

  • Identification of foreign materials
    • Particulates
    • Fibers
    • Residues
  • Identification of bulk material compounds
  • Identification of constituents in multilayered materials
  • Quantitation of silicone, esters, etc., as contamination on various materials

Contact us to discuss which evaluation method is best suited to solve your materials-related problems. Or visit our Handbook of Analytical Methods for Materials (HAMM) for more in-depth explanations and typical applications of the analytical methods used for the characterization and evaluation of materials and products.