Comprehensive Characterization of Organic Chemicals Associated with Urban Particulate Matter in China

Atmospheric particulate matter (PM) is considered a health
hazard;
however, the inadequate identification of the components of PM limits
our understanding of its specific toxic pollutants. Herein, by combining
three extraction solvents with different polarities (dichloromethane,
hexane, and acetonitrile) and three ionization modes (electron ionization
and the positive and negative modes of electrospray ionization), we
comprehensively analyzed the organic chemicals in the PM2.5 and PM10 samples collected during summer and winter in
Beijing. Suspect screening was facilitated by comparison with the
mzCloud and the National Institute of Standards and Technology databases
for tentatively characterizing chemical identities. Results showed
that more compounds were identified in the winter PM2.5/PM10 samples than in the summer samples and that PM2.5 contained a greater number of chemicals than PM10. Based on peak areas of compounds, the predominant pollutants in
the winter PM2.5/PM10 samples were phenols,
amines, and aromatic compounds; however, significantly high responses
of one phenol and two ester compounds were detected in the summer
PM2.5/PM10 samples. Based on the Tox21 toxicological
database, a total of 60 identified pollutants were associated with
28 biological targets, and ∼50% of the active compounds were
phenolic and aromatic compounds. The biological targets most affected
by these pollutants were related to metabolic homeostasis, reproduction,
and developmental functions. This study underscores the importance
of a multiapproach analysis in comprehensively identifying environmental
pollutants and highlights the potential health risks posed by PM.