Abstract. Amine-containing particles were characterized in an urban
area of Chongqing during both summer and winter using a single-particle
aerosol mass spectrometer (SPAMS). Among the collected particles, 12.7 %
were amine-containing in winter and 8.3 % in summer. Amines were internally
mixed with elemental carbon (EC), organic carbon (OC), sulfate, and nitrate.
Diethylamine (DEA) was the most abundant among amine-containing particles.
Wintertime amine-containing particles were mainly from the northwest
direction where a forest park was located; in summer, they were from the
northwest and southwest (traffic hub) directions. These origins suggest that
vegetation and traffic were the primary sources of particulate amines. The
average relative peak area of DEA depended strongly on humidity, indicating
that the enhancement of DEA was possibly due to increasing aerosol water
content and aerosol acidity. Using an adaptive resonance theory neural
network (ART-2a) algorithm, four major types of amine-containing particles
were clustered: amine–organic carbon (A-OC), A-OCEC, DEA-OC, and
A-OCEC aged. The identified particle types implied that amines were taken up
by particles produced from traffic and biomass burning. The knowledge gained in
this study is useful to understand the atmospheric processing, origin, and
sources of amine-containing particles in the urban area of Chongqing.
Atmospheric Processing of Loess Particles in a Polluted Urban Area of Northwestern China
