NMR spectroscopic applications to atmospheric organic aerosol analysis – Part 1: A critical review of data source and analysis, potentialities and limitations

NMR techniques have been used for more than two decades in atmospheric aerosol research. Compared to aerosol mass spectrometric techniques, NMR applications remain limited but provide complementary information on the C–H structural properties of particulate organic compounds. Such information can be key for organic aerosol source apportionment, provided that a representative library of source-specific reference spectra is let available. In recent years, chemical shift data for a number of atmospheric organic tracers have been reported but significant gaps remain, as well as in the NMR characterization of several secondary organic aerosol systems. Although factor analysis and other multivariate techniques are gaining importance in NMR organic source apportionment, the bulk of the literature studies is based on functional group analysis. The creation of a community of research groups would be highly beneficial in setting standards, overcoming technical limitations and dealing with the complexity of the NMR spectra of atmospheric aerosol extracts.