Analysis by Raman Spectroscopy in the laboratory
Raman spectroscopy is a non-destructive analytical technique based on the inelastic scattering of light. It allows the identification of the chemical composition and molecular structure of a material by providing a unique "vibrational fingerprint" to each molecule.
Requiring no sample preparation, rapid and highly specific, Raman spectroscopy is now widely used in the environmental, cosmetics, food, materials and animal health sectors.
What is Raman spectroscopy?
Raman spectroscopy relies on the interaction of a monochromatic laser beam with the molecules of a sample. During this interaction, most photons are scattered without a change in energy (Rayleigh scattering), but a small fraction undergoes inelastic scattering (Raman effect): the photons exchanged with the molecular vibrations change energy, which slightly alters their frequency.
This phenomenon allows the measurement of the characteristic vibrational modes of the chemical bonds present in the sample. The resulting Raman spectrum constitutes a unique molecular fingerprint , enabling 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 (Rayleigh) light to retain only the Raman signal.
- Spectrometer and detector (CCD) : analyze the energy variations of scattered photons to generate a Raman spectrum.
Technical characteristics of Raman spectroscopy
- Non-destructive technique , without contact or sample preparation
- Rapid measurement : real-time or near-instantaneous results
- High chemical specificity thanks to unique vibrational modes
- High spectral resolution suitable for detecting 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 well-suited to solid, pasty, or semi-liquid matrices , including colored or opaque ones. It is ideal for:
Léa Géréec
Technical and scientific expert
