Characterization of urban amine-containing particles in southwestern China: seasonal variation, source, and processing

Abstract

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.

Simultaneous measurements of urban and rural particles in Beijing – Part 2: Case studies of haze events and regional transport

“…Please refer to Part 1 for details (Chen et al, 2020). Briefly, the field studies were performed simultaneously at Peking University (116.32 • E, 39.99 • N) and Pinggu (117.05 • E, 40.17 • N) from 1 to 29 November 2016 (Fig.…”

“…1). The detailed description of these two sites is available from Chen et al (2020). The two sites represent both typical urban and rural areas respectively.…”

“…Single-particle chemical composition and mixing state can be used as a tracing system to explore the sources and origins of unique particle types (Chen et al, 2019b;Li et al, 2016). For example, by combining meteorological parameters, we can determine the sources and transport conditions of specific particle types (Chen et al, 2018(Chen et al, , 2020.…”

“…As mentioned in Part 1 (Chen et al, 2020), two SPAMSs were deployed simultaneously at Peking University (PKU) and Pinggu (PG) to monitor urban and rural particles in the Beijing region. In Part 2, the resolved particle types are used to trace the evolution, transport, and formation of pollution events.…”

Direct links between hygroscopicity and mixing state of ambient aerosols: Estimating particle hygroscopicity from their single particle mass spectra

“…As found previously (Wang et al, 2014), Amine-rich particles are generally very hydrophilic with the highest detection probability occurred within GF >1.5 range. Short alkyl chain aliphatic amines are basic and have relatively high vapor pressures, therefore their presence in particles most likely occur in the form of aminium salts, whose formation is greatly favored in the presence of particulate water (Angelino et al, 2001;Chen et al, 2019). It is found that 77% Amine-rich particles were internally mixed with sulfate or nitrate.…”