Fourier Transform Infrared Spectroscopy (FTIR)
| Category |
Chemical/Explosives |
| Type |
Analytical |
| Ease of Use |
 |
| Determination Capability |
 |
How it works
FTIR is an excellent tool for identification of unknown chemicals. As infrared energy is passed through or bounced off of a chemical, the bonds of the chemical absorb specific wavelengths of the infrared spectrum unique to that chemical. Wavelengths that are not absorbed (transmitted) pass through to the detector. A pattern, or spectrum, is created based on the absorbance pattern and compared to a database (library) for identification.
Advances such as Attenuated Total Reflection (ATR) sampling, which eliminates sample prep, have simplified FTIR such that it has become standard equipment for advanced CBRNE response. FTIR is commonly used to identify unknown liquids and solids. ATR sampling requires direct contact with the sample to perform the analysis.
Limitations
As with any technique, there are some limitations with FTIR. Mixtures are a challenge since the overlapping spectra prevent a clean library match unless the mixture is in the library already (e.g. coffee creamer).