spectrometrie

Spectroscopy, or spectrometry, is the study of the interaction between electromagnetic radiation and matter. It involves measuring how materials absorb, emit, scatter, or otherwise respond to light or other wavelengths, and interpreting the resulting spectra to infer properties such as composition, molecular structure, and concentration. The term spectroscopy refers to the analysis of spectra, while spectrometry emphasizes the measurement of spectral properties.

Spectroscopic methods are classified by the type of interaction examined, with common families including absorption spectroscopy (UV-visible and infrared), emission spectroscopy, fluorescence and phosphorescence spectroscopy, and Raman spectroscopy. X-ray and nuclear magnetic resonance techniques also fall under broader spectroscopic approaches. Mass spectrometry is closely related but centers on mass-to-charge ratios rather than spectral wavelengths; some instruments couple mass analysis with optical detection to form hybrid techniques.

Typical instrumentation comprises a light source, a sample holder, a dispersive element such as a prism or diffraction grating (or an interferometer in Fourier transform spectrometers), and a detector that records the spectral signal. The resulting spectrum shows intensity as a function of wavelength, frequency, or energy and is analyzed to determine identity, concentration, or physical parameters. Calibration and resolution are important considerations.

Applications span chemistry, physics, materials science, biology, environmental monitoring, medicine, and astronomy. Spectroscopy enables qualitative identification of compounds, quantitative measurements, and the study of dynamic processes such as reactions, vibrational modes, and electronic structure.

Historical roots lie in the observation of Fraunhofer lines in the solar spectrum and Newton’s prism experiments. The modern field expanded through advances in instrumentation and detectors in the 19th and 20th centuries, leading to widely used techniques in research and industry.