EPR (Electron Paramagnetic Resonance) spectroscopy is the only technique that unambiguously detects and quantifies species with unpaired electrons. These species include free radicals, transition metals and defects in materials.
EPR spectroscopy is featured in many disciplines such as medical science, biology, chemistry, physics, material science, archeology and forensics. This wide spread use is a direct result of the crucial role of free radicals and transition metals in many processes such as photosynthesis, oxidation/reduction, catalysis, and polymerization reactions .
Free radicals may also play a damaging role to their surroundings. Free radicals are involved in cancer, aging, Alzheimer’s, and cardiovascular diseases. Degradation of material properties such as brittleness and discoloration of polymers is frequently a result of free radical reactions.
In EPR spectroscopy, the sample can be a solid, a liquid, a gas, colored solutions, turbid solutions, or even a cell suspension. In the EPR measurement there is no contact with the sample so the sample is preserved for other analyses.