Analysis by Raman Spectroscopy in the laboratory
Raman spectroscopy is a non-destructive analysis technique based on inelastic light scattering. It can identify the chemical composition and molecular structure of a material by providing a unique "vibrational fingerprint" for each molecule.
Without sample preparation, rapid and highly specific, Raman spectroscopy is today widely used in the environmental, cosmetics, food, materials and animal health sectors.
What is Raman spectroscopy?
Raman spectroscopy is based on the interaction of a monochromatic laser beam with the molecules of a sample. During this interaction, most photons are scattered without changing their energy (Rayleigh scattering), but a small fraction undergo inelastic scattering (Raman effect): the photons exchanged with molecular vibrations change their energy, which slightly modifies their frequency.
This phenomenon makes it possible to measure the vibrational modes characteristic of the chemical bonds present in the sample. The Raman spectrum obtained constitutes a unique molecular fingerprint , allowing rapid and precise identification of compounds, whether organic, mineral or polymeric.
To learn more, check out our blog post dedicated to Raman spectroscopy .
How Raman spectroscopy works
A Raman spectroscopy system typically includes the following components:
- Laser source : illuminates the sample with a monochromatic beam (often in the visible or near infrared).
- Optical collection system : captures the light scattered by the sample.
- Optical filtering : eliminates elastically scattered light (Rayleigh) to retain only the Raman signal.
- Spectrometer and detector (CCD) : analyze the energy variations of the scattered photons to generate a Raman spectrum.
Technical characteristics of Raman spectroscopy
- Non-destructive technique , without contact or sample preparation
- Fast measurement : real-time or near-instantaneous results
- High chemical specificity thanks to unique vibrational modes
- High spectral resolution suitable for the detection of complex mixtures
- Compatible with various types of materials : solids, powders, liquids, gels, polymers, etc.
- Related techniques : Confocal Raman, micro-Raman, portable Raman
- Standards and regulatory frameworks : ISO 472, ISO 20473, REACH, CLP, pharmacopoeias according to sectors
For which matrices?
Raman spectroscopy is particularly suitable for solid, pasty or semi-liquid matrices , including colored or opaque ones. It is ideal for:
Main industrial applications
Léa Géréec
Technical and scientific advisor
