FTIR microscopy: for localized chemical analysis of micro-contaminants and defects
FTIR microscopy combines the principles of Fourier transform infrared spectroscopy with optical imaging, enabling the localization and chemical identification of microscopic areas within a sample . This non-destructive method is ideal for analyzing micro-contaminants, localized defects, inclusions, or thin layers in complex matrices. It is widely used in the materials, medical, cosmetics, packaging, and pharmaceutical industries.
What is FTIR microscopy?
FTIR microscopy ( or FTIR microspectroscopy) relies on integrating an optical microscope with an FTIR spectrometer . It allows for the visual targeting of a very precise area of the sample (down to a few micrometers) and the acquisition of its infrared spectrum . This spectrum reveals the chemical composition of the analyzed point, thus enabling the identification of contaminants, residues, degradations, or specific layers.
This technique is particularly suited to the study of local heterogeneities invisible to the naked eye, or to the characterization of very small quantities of matter .
How FTIR microscopy works
An FTIR microscopy system consists of:
- Optical microscope : allows precise visualization of the sample and selection of the area to be analyzed.
- FTIR system : records the IR spectrum of the targeted area.
- Specific IR objectives : ensure the focusing of the IR beam onto a micrometric surface.
- Analysis modes possible:
- Transmission : for thin or pellet-shaped samples
- Reflection (IRRAS, DRIFTS) : for flat or metallic surfaces
- ATR (Attenuated Total Reflectance) : for very localized areas or particles
Technical characteristics of FTIR microscopy
- Spatial resolution : up to 10 µm
- Non-destructive method
- Precise chemical identification in localized areas
- Compatible with complex or multi-layered samples
- Measurement possible on micro-fragments, inclusions, deposits, fibers…
- Spectra comparable to FTIR databases
- Applicable standards depending on the sector : ISO 16000-6, ICH Q2(R1), ISO 21461, REACH, pharmacopoeias, etc.
For which matrices?
FTIR microscopy is particularly well-suited to or semi-solid samples . It is ideal for:
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
