Fourier Transform Infrared (FTIR) Spectrometer

Brand/Model: Mattson Research 1

 

In infrared spectroscopy, IR radiation is passed through a sample. Some of the infrared radiation is absorbed by the sample and some of it is passed through (transmitted).

An infrared spectrum represents a fingerprint of a sample with absorption peaks which correspond to the frequencies of vibrations between the bonds of the atoms making up the material.

The resulting spectrum represents the molecular absorption and transmission, creating a molecular fingerprint of the sample. Because each different material is a unique combination of atoms, no two compounds produce the exact same infrared spectrum.

This makes infrared spectroscopy useful for several types of analysis.

Therefore, infrared spectroscopy can result in a positive identification (qualitative analysis) of every different kind of material. In addition, the size of the peaks in the spectrum is a direct indication of the amount of material present.

The FTIR spectrometer simultaneously collects high spectral resolution data over 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.

 

What information can FTIR provide?

  • identify unknown materials: types of chemical bonds (functional groups) in molecules
  • determine the quality or consistency of a sample
  • determine the amount of components in a mixture
  • applied to the analysis of solids, liquids, liquid and solids in solution, and gasses

 

Infrared Spectroscopy:

If sample absorbs infrared radiation, the variations of sample transmittance with frequency of radiation are recorded as an infrared absorption spectrum. The infrared spectrum contains basic information about the composition and structure of a compound. Organic compounds, for example, may contains groups such as -OH, -NH2, -CH3, -CO, -CN, -C-O-C-, -COOH, -CS, etc. These groups have characteristic absorption frequencies in the infrared which are usually relatively unaffected by the reminder of the molecule. An unknown compound, therefore, can be characterized by observing the presence of the absorption frequencies associated with such groups. Spectra-structure correlation charts provide a key to the location of characteristic absorption bands for most of the common functional groups.