Fourier transform infrared (FTIR) is a type of infrared (IR) spectroscopy that has been in existence for several decades now as a valuable tool to interrogate samples of unknown composition. FTIR is one of the most heavily used optical spectroscopy techniques by scientists in academia, government, and the industrial sector. Infrared spectroscopy takes advantage of the fact that atom-to-atom bonds vibrate at specific frequencies.
When energy, comprised of multiple frequencies (such as that from an infrared source), is introduced to these molecular vibrations, an absorption of that infrared energy occurs at that same molecular vibrational frequency. Plotting the intensity of the absorbance across a range of frequencies, yields an infrared spectrum. Furthermore, bonds of different types (e.g., double, triple) and different atoms (e.g, C–O, C–H, C–N, etc.) each have specific vibrational frequencies.
The specificity of these vibrational frequencies can be thought of as a fingerprint of the atom-to-atom bonds that make up a given molecule. This fingerprint then makes it possible to identify molecules or compounds in a mixture and likewise can detect the making and breaking of chemical bonds that occur in a reaction.
Learn more about FTIR spectroscopy.
