Fourier Transform Infrared Spectroscopy (FTIR): Precisely identify your materials, formulations and contaminants
FTIR (Fourier Transform Infrared) spectroscopy is a powerful spectroscopic analysis method for identifying organic and inorganic compounds based on their infrared absorption spectra. Widely used in the materials, packaging, cosmetics, food, and chemical industries, FTIR spectroscopy offers rapid, non-destructive, and highly specific analysis of solids, liquids, and gases.
What is FTIR spectroscopy?
Fourier transform infrared (FTIR) spectroscopy relies on the absorption of infrared radiation by molecules in a sample. Each chemical bond has a specific vibrational frequency; when exposed to IR light, it absorbs certain characteristic wavelengths.
The FTIR instrument records an interferogram (raw signal from the Michelson interferometer), which is then transformed into an IR spectrum by Fourier transform . This spectrum constitutes a unique chemical fingerprint allowing rapid and reliable identification of the materials or substances present.
How FTIR spectroscopy works
An FTIR spectrometer generally operates according to the following scheme:
- Infrared source : emits broad radiation in the IR range (usually between 4000 and 400 cm⁻¹).
- Michelson interferometer : modulates the IR signal to generate an interferogram.
- Sample : Radiation passes through or is reflected by the sample (transmission, reflection or ATR mode).
- Detector : Records the signal absorbed at different wavelengths.
- Fourier Transform : Converts the time signal into an IR spectrum.
Technical characteristics of FTIR spectroscopy
- Rapid analysis : results obtained in seconds to minutes
- Non-destructive method , without complex sample preparation
- Compatibility with different analysis modes :
- Transmission : thin or pellet samples
- Reflection (DRIFTS, specular reflection) : surfaces or powders
- ATR (Attenuated Total Reflectance) : solid, liquid, pasty samples without preparation
- spectral range : 4000 to 400 cm⁻¹
- Qualitative and semi-quantitative
- Related standards : ISO 21461, ISO 10640, ASTM E1252, ICH Q2(R1), REACH, CLP
For which matrices?
FTIR spectroscopy is compatible with a wide variety of matrices, both organic and inorganic, in all physical states:
Main industrial applications
LC-MS and LC-MS/MS are widely used in R&D, method validation, quality control and regulatory compliance , particularly in the following sectors:
Léa Géréec
Technical and scientific advisor
