Fourier-Transform Infrared (FTIR) Spectroscopy

FTIR stands for Fourier-Transform Infrared, the preferred method of infrared spectroscopy. 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). The resulting 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. Because each different material is a unique combination of atoms, no two compounds produce the exact same infrared spectrum. 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. With modern software algorithms, infrared is an excellent tool for quantitative analysis.

Infrared spectroscopy is useful for several types of analysis, including for:

• Identification of unknown materials
• Determination of the quality or consistency of a sample
• Quantification of components of interest or additives or contaminants in a mixture
• Kinetic information through the growth or decay of infrared absorptions