Monitoring free radicals and other species with unpaired electrons (such as some transition metal ions and defects in materials) in the environment is of critical importance. Free radicals are usually short-lived, and play important roles in processes such as photosynthesis, oxidation, catalysis and polymerization. However, long-lived species, known as environmentally persistent free radicals (EPFRs), can remain in the environment almost indefinitely.
Electron paramagnetic resonance (EPR) spectroscopy is the only analytical technique capable of detecting species with unpaired electrons, in a direct and non-invasive manner. It can be used to detect, quantify and monitor the intrinsic generation of short-lived radicals, such as hydroxyl radicals, as well as EPFRs. EPR is therefore extremely useful for tracking free radicals in the environment, in addition to detecting toxic metal ions in the air, groundwater and soil, and monitoring their uptake by plants. By furthering this knowledge, researchers can also increase their understanding of the behavior of free radicals in the body and their impacts on human disease