ABSTRACT
This chapter describes the basic physical principle of electron paramagnetic resonance (EPR) and its applications to the study of paramagnetic aerosols. It provides an evidence that suggests the EPR method as a very powerful and useful tool with high potential for estimations of carbonaceous pollutants present as aerosols in urban air. The structure of the paramagnetic species which are recorded by EPR is a topic for discussion. The advantages of the high selectivity of EPR spectroscopy to estimate the quantity of only paramagnetic carbonaceous products has been shown. EPR spectrometers are complicated electronic instruments which are typically commercially available. The singlet EPR spectra of some aromatic cation radicals like anthracene, perylene, naphthacene, etc., were found upon their formation on the surface of a strongly calcinated silica/alumina adsorbent of the type used as a catalyst in the cracking of hydrocarbons. The initial steps have been taken, and EPR seems promising for increasing the quality of human environment monitoring.
