Spektroskopiaa

Spektroskopiaa is the study of how electromagnetic radiation interacts with matter. It analyzes absorption, emission, or scattering of light by atoms and molecules to determine composition, structure, and properties. Spectra act as fingerprints, reflecting electronic, vibrational, rotational, or nuclear transitions depending on the energy scale involved.

Techniques are categorized by interaction type. Absorption spectroscopy measures light lost to the sample; emission spectroscopy detects light released after excitation. Fluorescence and phosphorescence observe delayed emission. Raman spectroscopy relies on inelastic scattering; infrared and UV–visible spectroscopy probe vibrational or electronic transitions. NMR uses radiofrequency in a magnetic field to reveal molecular structure.

Instrumentation includes a light source, sample, dispersive or interferometric element, and a detector such as a photodiode or CCD. Modern systems use computer processing to convert spectra into qualitative and quantitative information. Data interpretation often relies on calibration, reference standards, and models like Beer–Lambert for absorbance.

Historically, spectroscopy emerged in the 19th century with Kirchhoff and Bunsen and advanced quantum theory. Today it underpins chemistry, physics, astronomy, environmental science, medicine, and industry, enabling material identification, concentration measurements, remote sensing, pollutant analysis, and quality control. Limitations include overlapping spectra and calibration requirements; ongoing work targets sensitivity and data analysis.