On-line Analysis of Urban Particulate Matter Focusing on Elevated Wintertime Aerosol Concentrations

Abstract

A 10-day winter sampling campaign was conducted in downtown Toronto for particulate matter (PM) air pollution in the fine (<2.5 microm) size range. An aerosol laser ablation mass spectrometer (LAMS), a tapered-element oscillating microbalance (TEOM), and an aerodynamic particle sizer (APS) were operated in parallel to characterize the PM on-line. In this study, the LAMS observed differences in the chemical composition between three separate episodes with higher PM2.5 mass and APS counts. LAMS results showed that in one instance of elevated PM, organic amines were present in the particulates. Temporal analyses of this episode revealed chemical transformations as the amines, characterized by m/z peaks 58(C3HeN)+, 86(C5H2N)+, and nitrates, increased in number concentration while Ca and hydrocarbon particle classes concurrently decreased. On another day, sulfates were found to have increased significantly. The third event was only 4 h in duration and exhibited an increase in the number of submicron-sized K/hydrocarbons and sulfate-containing particles. In this last event, the hydrocarbons and a K to Fe ratio enrichment indicated there was likely a contribution from a combustion source. This work offers some of the first insights into single particle size and chemistry in a cold winter climate.

The ozonolysis of primary aliphatic amines in fine particles

“…Recent field observations have positively correlated episodic aerosol formation events with elevated concentrations of atmospheric amines. For example, Tan et al have found in one episodic event of elevated PM 2.5 in an urban environment that organic amines were evident in all the particulate (Tan et al, 2002). Similarly, in remote boreal forest studies, Mäkelä and coworkers (Mäkelä et al, 2001) found a strong positive correlation between new particle formation events and the concentration of dimethylammonium (the ionic component of dimethylamine).…”

“…There is growing evidence that organic nitrogen, including amines and amine-derived compounds, may form a substantial fraction of the organic aerosol load as evidenced in recent field studies in remote (Mäkelä et al, 2001;Beddows et al, 2004), urban (McGregor and Anastasio, 2001;Simoneit et al, 2003;Angelino et al, 2001;Tan et al, 2002), and agricultural (McGregor and Anastasio, 2001;Angelino et al, 2001) regions, and in regions near extensive biomass burning (Decesari et al, 2006;Mace et al, 2003;Simoneit et al, 2003).…”

Enhanced trimethylamine-containing particles during fog events detected by single particle aerosol mass spectrometry in urban Guangzhou, China

“…Tan et al (2002) suggested that the presence of the TMA within aqueous surface on particles would promote the accumulation of sulfate and nitrate (R2 and R3). TMA also has the potential to undergo gas phase acidebase reactions (R4) with gaseous acids (e.g., HCl, HNO 3 and H 2 SO 4 ) mimic ammonia to form inorganic salts (Angelino et al, 2001;Murphy et al, 2007).…”

Single particle analysis of amines in ambient aerosol in Shanghai

“…[13,[18][19][20] De Haan et al [21,22] observed that reactions between glyoxal and amines or amino acids can produce light-absorbing, nitrogen-containing imidazoles and oligomers. Particle phase amines have been extensively observed in many areas [9,17,[23][24][25] especially in ultrafine particles during nucleation [26][27][28] and particle growth [29] events. Compared with ammonia, amines have higher molecular weights and present stronger alkalinity that make them perfect candidates in new particle formation and growth.…”