Chemical characterization of fine organic aerosol for source apportionment at Monterrey, Mexico

Abstract. Primary emissions from anthropogenic and biogenic sources as well as secondary formation are responsible for the pollution levels of ambient air in major urban areas. These sources release fine particles into the air that negatively impact human health and the environment. Organic molecular markers, which are compounds that are unique to specific PM2.5 sources, can be utilized to identify the major emission sources in urban areas. In this study, 43 representative PM2.5 samples, for both daytime and nighttime periods, were built from individual samples collected in an urban site of the Monterrey Metropolitan Area (MMA) during the spring and fall of 2011 and 2012. The samples were analyzed for organic carbon, elemental carbon, and organic molecular markers. Several diagnostic tools were employed for the preliminary identification of emission sources. Organic compounds for eight compound classes were quantified. The n-alkanoic acids were the most abundant, followed by n-alkanes, wood smoke markers, and levoglucosan/alkenoic acids. Polycyclic aromatic hydrocarbons (PAHs) and hopanes were less abundant. The carbon preference index (0.7–2.6) for n-alkanes indicate a major contribution of anthropogenic and mixed sources during the fall and the spring, respectively. Hopanes levels confirmed the contribution from gasoline and diesel engines. In addition, the contribution of gasoline and diesel vehicle exhaust was confirmed and identified by the PAH concentrations in PM2.5. Diagnostic ratios of PAH showed emissions from burning coal, wood, biomass, and other fossil fuels. The total PAH and elemental carbon (EC) were correlated (r2 = 0.39–0.70) across the monitoring periods, reinforcing that motor vehicles are the major contributors of PAH. Cholesterol levels remained constant during the spring and fall, showing evidence of the contribution of meat cooking operations, while the isolated concentrations of levoglucosan suggested occasional biomass burning events. Finally, source attribution results obtained using the CMB model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5. The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is the second study to explore the broad chemical characterization of fine organic aerosol in Mexico and the first for the MMA.

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Organic composition and source apportionment of fine aerosol at Monterrey, Mexico, based on organic markers

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-953-2016 ◽

2016 ◽

Vol 16 (2) ◽

pp. 953-970 ◽

Cited By ~ 18

Author(s):

Y. Mancilla ◽

A. Mendoza ◽

M. P. Fraser ◽

P. Herckes

Keyword(s):

Molecular Markers ◽

Source Apportionment ◽

Biomass Burning ◽

Urban Areas ◽

Elemental Carbon ◽

Ambient Air ◽

Urban Site ◽

Emission Sources ◽

Organic Composition ◽

Meat Cooking

Abstract. Primary emissions from anthropogenic and biogenic sources as well as secondary formation are responsible for the pollution levels of ambient air in major urban areas. These sources release fine particles into the air that negatively impact human health and the environment. Organic molecular markers, which are compounds that are unique to specific PM2.5 sources, can be utilized to identify the major emission sources in urban areas. In this study, 43 representative PM2.5 samples, for both daytime and nighttime periods, were built from individual samples collected in an urban site of the Monterrey metropolitan area (MMA) during the spring and fall of 2011 and 2012. The samples were analyzed for organic carbon, elemental carbon, and organic molecular markers. Several diagnostic tools were employed for the preliminary identification of emission sources. Organic compounds for eight compound classes were quantified. The n-alkanoic acids were the most abundant, followed by n-alkanes, wood smoke markers, and levoglucosan/alkenoic acids. Polycyclic aromatic hydrocarbons (PAHs) and hopanes were less abundant. The carbon preference index (0.7–2.6) for n-alkanes indicates a major contribution of anthropogenic and mixed sources during the fall and the spring, respectively. Hopanes levels confirmed the contribution from gasoline and diesel engines. In addition, the contribution of gasoline and diesel vehicle exhaust was confirmed and identified by the PAH concentrations in PM2.5. Diagnostic ratios of PAHs showed emissions from burning coal, wood, biomass, and other fossil fuels. The total PAHs and elemental carbon were correlated (r2 =  0.39–0.70) across the monitoring periods, reinforcing that motor vehicles are the major contributors of PAHs. Cholesterol levels remained constant during the spring and fall, showing evidence of the contribution of meat-cooking operations, while the isolated concentrations of levoglucosan suggested occasional biomass burning events. Finally, source attribution results obtained using the CMB (chemical mass balance) model indicate that emissions from motor vehicle exhausts are the most important, accounting for the 64 % of the PM2.5, followed by meat-cooking operations with 31 % The vegetative detritus and biomass burning had the smallest contribution (2.2 % of the PM2.5). To our knowledge, this is only the second study to explore the organic composition and source apportionment of fine organic aerosol based on molecular markers in Mexico and the first for the MMA. Particularly molecular marker were quantified by solvent extraction with dichloromethane, derivatization, and gas chromatography with mass spectrometry (GC/MS).

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One-year record of organic and elemental carbon in fine particles in downtown Beijing and Shanghai

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-5-217-2005 ◽

2005 ◽

Vol 5 (1) ◽

pp. 217-241 ◽

Cited By ~ 14

Author(s):

F. Yang ◽

K. He ◽

B. Ye ◽

X. Chen ◽

L. Cha ◽

...

Keyword(s):

Time Series ◽

Urban Areas ◽

Elemental Carbon ◽

Significant Contribution ◽

Fine Particles ◽

Organic Aerosol ◽

Meteorological Conditions ◽

Annual Average ◽

One Year ◽

Fine Organic

Abstract. Weekly PM2.5 samples were collected for one year in Beijing and Shanghai and the carbonaceous species analyzed to investigate and compare their time series patterns and possible sources in the two biggest cities of China. Weekly carbonaceous concentrations varied in wide ranges with 8.6–59 µg m-3 for OC and 1.5–25.4 µg m-3 for EC in Beijing, and with 5.1–38.4 µg m-3 for OC and 2.3–13.0 µg m-3 for EC in Shanghai. The annual average concentrations of OC and EC in PM2.5 were 23.9 and 8.8 µg m-3 in Beijing and 14.6 and 6.10 µg m-3 in Shanghai, respectively. Similar weekly variations of OC and EC concentrations were found for both cities with much higher concentrations in late fall through winter, probably due to enhanced emissions coupled with unfavorable meteorological conditions. The estimated SOC accounted for high portion of the total OC in both Beijing and Shanghai throughout the year, indicating SOC may be an important contributor to fine organic aerosol in these urban areas. In Beijing, the C14 analysis of limited samples suggested there was a significant contribution of modern carbon to the total fine carbonaceous particulate burden with higher fractions in the harvest seasons.

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Nighttime chemistry of biomass burning emissions in urban areas: A dual mobile chamber study

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-15337-2021 ◽

2021 ◽

Vol 21 (19) ◽

pp. 15337-15349

Author(s):

Spiro D. Jorga ◽

Kalliopi Florou ◽

Christos Kaltsonoudis ◽

John K. Kodros ◽

Christina Vasilakopoulou ◽

...

Keyword(s):

Biomass Burning ◽

Urban Areas ◽

Mass Spectra ◽

Ambient Air ◽

Organic Aerosol ◽

Photochemical Activity ◽

Organic Nitrate ◽

Starting Point ◽

No3 Radical ◽

High Concentrations

Abstract. Residential biomass burning for heating purposes is an important source of air pollutants during winter. Here we test the hypothesis that significant secondary organic aerosol production can take place even during winter nights through oxidation of the emitted organic vapors by the nitrate (NO3) radical produced during the reaction of ozone and nitrogen oxides. We use a mobile dual smog chamber system which allows the study of chemical aging of ambient air against a control reference. Ambient urban air sampled during a wintertime campaign during nighttime periods with high concentrations of biomass burning emissions was used as the starting point for the aging experiments. Biomass burning organic aerosol (OA) was, on average, 70 % of the total OA at the beginning of our experiments. Ozone was added in the perturbed chamber to simulate mixing with background air (and subsequent NO3 radical production and aging), while the second chamber was used as a reference. Following the injection of ozone, rapid OA formation was observed in all experiments, leading to increases in the OA concentration by 20 %–70 %. The oxygen-to-carbon ratio of the OA increased on average by 50 %, and the mass spectra of the produced OA was quite similar to the oxidized OA mass spectra reported during winter in urban areas. Furthermore, good correlation was found for the OA mass spectra between the ambient-derived emissions in this study and the nocturnal aged laboratory-derived biomass burning emissions from previous work. Concentrations of NO3 radicals as high as 25 ppt (parts per trillion) were measured in the perturbed chamber, with an accompanying production of 0.1–3.2 µg m−3 of organic nitrate in the aerosol phase. Organic nitrate represented approximately 10 % of the mass of the secondary OA formed. These results strongly indicate that the OA in biomass burning plumes can chemically evolve rapidly even during wintertime periods with low photochemical activity.

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Detailed chemical characterization of unresolved complex mixtures in atmospheric organics: Insights into emission sources, atmospheric processing, and secondary organic aerosol formation

Journal of Geophysical Research Atmospheres ◽

10.1002/jgrd.50533 ◽

2013 ◽

Vol 118 (12) ◽

pp. 6783-6796 ◽

Cited By ~ 44

Author(s):

Arthur W. H. Chan ◽

Gabriel Isaacman ◽

Kevin R. Wilson ◽

David R. Worton ◽

Christopher R. Ruehl ◽

...

Keyword(s):

Secondary Organic Aerosol ◽

Chemical Characterization ◽

Organic Aerosol ◽

Complex Mixtures ◽

Emission Sources ◽

Aerosol Formation ◽

Atmospheric Processing ◽

Secondary Organic Aerosol Formation ◽

Detailed Chemical

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Night-time chemistry of biomass burning emissions in urban areas: A dual mobile chamber study

10.5194/acp-2021-284 ◽

2021 ◽

Author(s):

Spiro Jorga ◽

Kalliopi Florou ◽

Christos Kaltsonoudis ◽

John Kodros ◽

Christina Vasilakopoulou ◽

...

Keyword(s):

Biomass Burning ◽

Urban Areas ◽

Mass Spectra ◽

Ambient Air ◽

Organic Aerosol ◽

Photochemical Activity ◽

Organic Nitrate ◽

Night Time ◽

Starting Point ◽

No3 Radical

Abstract. Residential biomass burning for heating purposes is an important source of air pollutants during winter. Here we test the hypothesis that significant secondary organic aerosol production can take place even during winter nights through oxidation of the emitted organic vapors by the nitrate (NO3) radical produced during the reaction of ozone and nitrogen oxides. We use a mobile dual smog chamber system which allows the study of chemical aging of ambient air against a control reference. Ambient urban air sampled during a wintertime campaign during night-time periods with high concentrations of biomass burning organic aerosol was used as the starting point of the aging experiments. Ozone was added in the perturbed chamber to simulate mixing with background air (and subsequent NO3 radical production and aging), while the second chamber was used as a reference. Following the injection of ozone rapid organic aerosol (OA) formation was observed in all experiments leading to increases of the OA concentration by 20–70 %. The oxygen-to-carbon ratio of the OA increased on average by 50 % and the mass spectra of the produced OA was quite similar to the oxidized OA mass spectra reported during winter in urban areas. Further, good correlation was found for the OA mass spectra between the ambient-derived emissions in this study and the nocturnal aged laboratory-derived biomass burning emissions from previous work. Concentrations of NO3 radicals as high as 25 ppt were measured in the perturbed chamber with an accompanying production of 0.1–3.2 μg m−3 of organic nitrate in the aerosol phase. These results strongly indicate that the OA in biomass burning plumes can chemically evolve rapidly even during wintertime periods with low photochemical activity.

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Chemical characterization of SOA formed from aqueous-phase reactions of phenols with the triplet excited state of carbonyl and hydroxyl radical

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-21149-2014 ◽

2014 ◽

Vol 14 (15) ◽

pp. 21149-21187 ◽

Cited By ~ 4

Author(s):

L. Yu ◽

J. Smith ◽

A. Laskin ◽

C. Anastasio ◽

J. Laskin ◽

...

Keyword(s):

Mass Spectrometry ◽

Hydroxyl Radical ◽

Aqueous Phase ◽

Biomass Burning ◽

Chemical Characterization ◽

Ambient Air ◽

Organic Aerosol ◽

Formation Mechanisms ◽

Hydroxyl Groups ◽

Ionization Mass

Abstract. Phenolic compounds, which are emitted in significant amounts from biomass burning, can undergo fast reactions in atmospheric aqueous phases to form secondary organic aerosol (aqSOA). In this study, we investigate the reactions of phenol and two methoxy-phenols (syringol and guaiacol) with two major aqueous phase oxidants – the triplet excited states of an aromatic carbonyl (3C*) and hydroxyl radical (&centerdot;OH). We thoroughly characterize the low-volatility species produced from these reactions and interpret their formation mechanisms using aerosol mass spectrometry (AMS), nanospray desorption electrospray ionization mass spectrometry (nano-DESI MS), and ion chromatography (IC). A large number of oxygenated molecules are identified, including oligomers containing up to six monomer units, functionalized monomer and oligomers with carbonyl, carboxyl, and hydroxyl groups, and small organic acid anions (e.g., formate, acetate, oxalate, and malate). The average atomic oxygen-to-carbon (O / C) ratios of phenolic aqSOA are in the range of 0.85–1.23, similar to those of low-volatility oxygenated organic aerosol (LV-OOA) observed in ambient air. The aqSOA compositions are overall similar for the same precursor, but the reactions mediated by 3C* are faster than &centerdot;OH-mediated reactions and produce more oligomers and hydroxylated species at the point when 50% of the phenol had reacted. Profiles determined using a thermodenuder indicate that the volatility of phenolic aqSOA is influenced by both oligomer content and O / C ratio. In addition, the aqSOA shows enhanced light absorption in the UV-vis region, suggesting that aqueous-phase reactions of phenols are likely an important source of brown carbon in the atmosphere, especially in regions influenced by biomass burning.

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Night-time chemistry of biomass burning plumes in urban areas: A dual mobile chamber study

10.5194/egusphere-egu21-8469 ◽

2021 ◽

Author(s):

Spiro Jorga ◽

Kalliopi Florou ◽

Christos Kaltsonoudis ◽

John Kodros ◽

Christina Vasilakopoulou ◽

...

Keyword(s):

Biomass Burning ◽

Urban Areas ◽

Mass Spectra ◽

Prescribed Burning ◽

Organic Aerosol ◽

Photochemical Activity ◽

Organic Nitrate ◽

Night Time ◽

Starting Point ◽

High Concentrations

Biomass burning including residential heating, agricultural fires, prescribed burning, and wildfires is a major source of gaseous and particulate pollutants in the atmosphere. Although, important changes in the size distributions and the chemical composition of the biomass burning aerosol during daytime chemistry have been observed, the corresponding changes at nighttime or in winter where photochemistry is slow, have received relatively little attention. In this study, we tested the hypothesis that nightime chemistry in biomass burning plumes can be rapid in urban areas using a dual smog chamber system.&#160;Ambient urban air during winter nighttime periods with high concentrations of ambient biomass burning organic aerosol is used as the starting point. Ozone was added in the perturbed chamber to simulate mixing with background air (and subsequent NO3 production and aging) while the second chamber was used as a reference. Following the injection of ozone rapid organic aerosol (OA) formation was observed in all experiments leading to increases of the OA concentration by 20-70%. The oxygen to carbon ratio of the OA increased by 50% on average and the mass spectra of the produced OA was quite similar to that of the oxidized OA mass spectra reported during winter in urban areas. Good correlation was also observed with the produced mass spectra from nocturnal aging of laboratory biomass burning emissions showing the strong contribution of biomass burning emissions in the SOA formation during cold nights with high biomass burning activities. Concentrations of NO3 radicals as high as 25 ppt were measured in the perturbed chamber with an accompanying production of 0.2-1.2 &#956;g m-3 of organic nitrate. These results strongly indicate that the OA in biomass burning plumes can evolve rapidly even during wintertime periods with low photochemical activity.

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