Nuclear Magnetic Resonance Aerosolomics: A Tool for Analysis of Polar Compounds in Atmospheric Aerosols

Nuclear magnetic resonance aerosolomics
was proposed as a new approach
to the analysis of the water-soluble organic compound fraction in
aerosol particulate matter. The identification of individual compounds
is based on a comparison of precise chemical shifts in the 1H NMR spectrum with the signals in the standards library. For this
purpose, Chenomx metabolomics software and a comprehensive spectra
library of 150 compounds known from chemistry of aerosols were used.
This approach enabled the identification of 60 compounds in real aerosol
samples collected at a suburban site in Prague. Using the metabolomic
spectra library, three new compounds were identified in aerosols for
the first time, and an association of four other compounds to the
atmospheric particulate matter was confirmed. The obtained concentration
profiles of all identified chemical individuals were subsequently
subjected to advanced statistical analysis. NMR aerosolomics clearly
differentiates between summer and winter aerosol samples via multivariate
statistical analysis and revealed some interesting trends in composition,
according to aerosol particle size. Furthermore, the univariate statistical
analysis was applied to highlight compounds responsible for the group
separation, and possible sources of these compounds were suggested.