Characterization of urban amine-containing particles in Southwestern China: seasonal variation, source, and processing (original) (raw)
Related papers
Molecular, Seasonal, and Spatial Distributions of Organic Aerosols from Fourteen Chinese Cities
Environmental Science & Technology, 2006
Organic aerosols were studied at the molecular level in 14 coastal and inland mega-cities in China during winter and summer 2003. They are characterized by the abundant presence of n-alkanes (annual average, 340 ng m-3), fatty acids (769 ng m-3), sugars (412 ng m-3), and phthalates (387 ng m-3). In contrast, fatty alcohols, polyols/polyacids, lignin and resin products, sterols, polycyclic aromatic hydrocarbons (PAHs), and hopanes were detected as relatively minor components. n-Alkanes show a weak odd/even carbon predominance (CPI) 1.1) and PAHs show a predominance of benzo(b)fluoranthene, suggesting a serious contribution from fossil fuel (mainly coal) combustion. Their concentrations (except for phthalates and polyols/polyacids) were 2-15 times higher in winter than summer due to a significant usage of coal burning and an enhancement of atmospheric inversion layers. Phthalates were found to be more abundant in summer than winter, probably due to enhanced vaporization from plastics followed by adsorptive deposition on the pre-existing particles. Concentrations of total quantified compounds are extremely high (∼10 µg m-3) in the midwest (Chongqing and Xi'an) where active industrialization/urbanization is going on. This study shows that concentrations of the compounds detected are 1-3 orders of magnitude higher than those reported from developed countries.
Atmospheric amines and ammonia measured with a Chemical Ionization Mass Spectrometer (CIMS)
Atmospheric Chemistry and Physics Discussions, 2014
We report ambient measurements of amines and ammonia with a fast response chemical ionization mass spectrometer (CIMS) in a southeastern US forest in Alabama and a moderately polluted Midwestern site during the summer. In the Alabama forest, mostly C3-amines (from pptv to tens of pptv) and ammonia (up to 2 ppbv) were detected on a daily basis. C3-amines and ammonia showed similar diurnal trends and temperature and wind direction dependences, and were not associated with transported CO and SO 2 plumes. Consistent with temperature dependences, amine and ammonia in the gas and aerosol phases showed opposite diurnal trends, indicating gas-to-particle partitioning of amines and ammonia. Temperature dependences also imply reversible processes of amines and ammonia evaporation from soil surfaces in daytime and deposition of amines and ammonia to soil surfaces at nighttime. Various amines (C1-C6) at the pptv level were observed in the transported biomass burning plumes, showing that biomass burning can be a substantial source of amines in the Southeast US. At the moderately polluted Kent site, higher concentrations of amines (C1-C6, from pptv to tens of pptv) and ammonia (up to 6 ppbv) were detected. Diurnal variations of C1-to C3-amines and ammonia were correlated with the ambient temperature. C4-to C6-amines showed abrupt increases during the nighttime, suggesting that they were emitted from local sources. These abundant amines and ammonia may in part explain the frequent new particle formation events reported from Kent. Lower amine concentrations at the rural forested site highlight the importance of constraining anthropogenic sources of amines.
Talanta, 2012
A complete methodology was developed for the determination of ten aliphatic and nine aromatic amines in atmospheric aerosol particles. Before the liquid chromatographytandem mass spectrometric separation and determination, the derivatization reaction of the analytes using dansyl chloride was accelerated by ultrasounds. From three different ionization techniques studied electrospray ionization was superior in terms of sensitivity, linearity, repeatability and reproducibility over atmospheric pressure chemical ionization and photoionization for the target analytes. The method developed was validated for the gas phase, 30 nm and total suspended atmospheric aerosol particles. The method quantification limits ranged between 1.8 and 71.7 pg. The accuracy and the potential matrix effects were evaluated using a standard addition methodology. Recoveries from 92.1% to 109.1%, the repeatability from 0.6% to 8.4% and the reproducibility from 2.3% to 9.8% were obtained. The reliability of the methodology was proved by the statistical evaluation. Finally, the developed methodology was applied to the determination of the target analytes in eight size separated ultrafine particulate (Dp ¼ 30 7 4 nm) samples and in eight total suspended particulate samples collected at the SMEAR II station. The mean concentrations for aliphatic amines were between 0.01 and 42.67 ng m À 3 and for aromatic amines between 0.02 and 1.70 ng m À 3. Thirteen amines were quantified for the first time in 30 nm aerosol particles.
Sulfuric acid-amine nucleation in urban Beijing
New particle formation (NPF) is one of the major sources of atmospheric ultrafine particles. Due to the high aerosol and trace gas concentrations, the mechanism and governing factors for NPF in the polluted atmospheric boundary layer may be quite different from those in clean environments, which is however less understood. Herein, based on long-term atmospheric measurements from January 2018 to March 2019 in Beijing, the nucleation mechanism and the influences of H 2 SO 4 concentration, amine concentrations, and aerosol concentration on NPF are quantified. The collision of H 2 SO 4-amine clusters is found to be the dominating mechanism to initialize NPF in urban Beijing. The coagulation scavenging due to the high aerosol concentration is a governing factor as it limits the concentration of H 2 SO 4amine clusters and new particle formation rates. The formation of H 2 SO 4-amine clusters in Beijing is sometimes limited by low amine concentrations. Summarizing the synergistic effects of H 2 SO 4 concentration, amine concentrations, and aerosol concentration, we elucidate the governing factors for H 2 SO 4-amine nucleation for various conditions.
Environmental Science & Technology
Over 90 organic species have been determined in fine aerosols (PM 2.5) collected during the summer and winter in Nanjing, a typical mega-city in China, using gas chromatography-mass spectrometry. The organic compounds detected were apportioned to four emission sources (i.e., plant emission, fossil fuel combustion, biomass burning, and soil resuspension) and secondary oxidation products. The most abundant classes of compounds are fatty acids, followed by sugars, dicarboxylic acids excluding oxalic and malonic acids, and n-alkanes, while alcohols, polyols/polyacids and lignin/sterols are less abundant. Total amounts of the seven classes of compounds were on average 938 ng m-3 in the summer and 1301 ng m-3 in the winter, respectively, contributing 0.26-1.96% of particle mass (PM 2.5). In the summer, n-alkanes were heavily enhanced by vegetation emissions with a maximum carbon number (C max) at C 29 , whereas they were dominated by emissions from fossil fuels combustion with a C max at C 22 / C 23 in the winter. Concentrations of unsaturated fatty acids were lower in the summer than in the winter, being consistent with enhanced photooxidation of unsaturated fatty acids in the summer. Concentrations of dicarboxylic acids for the summer aerosols were much higher in the daytime than in the nighttime, indicating increased photochemical production in the daytime. In the summer, plant emissions were the most significant source of organic aerosols, contributing more than 33% of total compound mass (TCM), followed by fossil fuel combustion or secondary oxidation. In contrast, fossil fuel combustion was the dominant source of winter organic aerosols, contributing more than 51% of TCM, followed by plant emissions and secondary oxidation products. The quantitative results on sugars and lignin pyrolysis products further suggested that biomass burning and soil resuspension are also significant sources of urban organic aerosols.
Atmospheric Environment, 2007
PMB 2.5 B aerosols were collected in Nanjing, a typical mega-city in China, during summer and winter 2004 and were characterized for aromatic and cyclic compounds using a GC/MS technique to understand the air pollution problem. They include polycyclic aromatic hydrocarbons (PAHs), hopanes, phthalates and hydroxy-PAHs (OH-PAHs). PAHs, hopanes and OH-PAHs presented higher concentrations in winter (26−178, 3.0−18, and 0.013−0.421 ng mP-3 P, respectively) than in summer (12−96, 1.6−11, and 0.029−0.171 ng mP-3 P, respectively) due to an enhanced coal burning for house heating and atmospheric inversion layers developed in the cold season. In contrast, phthalates are much more abundant in summer (109−368 ng mP-3 P, average 230 ng mP-3 P) than in winter (33−390 ng mP-3 P, average 170 ng mP-3 P) due to an enhanced evaporation from plastics during the hot season and the subsequent deposition on the pre-existing particles. Generally, all the identified compounds are more abundant in nighttime than in daytime due to inversion layers and increased emissions from heavy-duty trucks at night. PAHs, hopanes and phthalates in Nanjing aerosols are 5−100 times more abundant than those in Los Angeles, USA, indicating a serious air pollution problem in the city. Concentrations of OH-PAHs are 1−3 orders of magnitude less than their parent PAHs and comparable to those reported from other international cities. Source identification using diagnostic ratios of the organic tracers suggests that PAHs in Nanjing urban area are mainly derived from coal burning, whereas hopanes are more attributable to traffic emissions.
Journal of Environmental Sciences, 2016
Atmospheric aerosol samples (PM 2.5-0.3 , i.e., atmospheric particles ranging from 0.3 to 2.5 μm) were collected during two periods: spring-summer 2008 and autumn-winter 2008-2009, using high volume samplers equipped with cascade impactors. Two sites located in the Northern France were compared in this study: a highly industrialised city (Dunkirk) and a rural site (Rubrouck). Physicochemical analysis of particulate matter (PM) was undertaken to propose parameters that could be used to distinguish the various sources and to exhibit seasonal variations but also to provide knowledge of chemical element composition for the interpretation of future toxicological studies. The study showed that PM 2.5-0.3 concentration in the atmosphere of the rural area remains stable along the year and was significantly lower than in the urban or industrial ones, for which concentrations increase during winter. High concentrations of polycyclic aromatic hydrocarbons (PAHs), dioxins, furans and dioxin like polychlorinated biphenyls (DL-PCBs), generated by industrial activities, traffic and municipal wastes incineration were detected in the samples. Specific criteria like Carbon Preference Index (CPI) and Combustion PAHs/Total PAHs ratio (CPAHs/TPAHs) were used to identify the possible sources of atmospheric pollution. They revealed that paraffins are mainly emitted by biogenic sources in spring-summer whereas as in the case of PAHs, they have numerous anthropogenic emission sources in autumn-winter (mainly from traffic and domestic heating).
Composition and major sources of organic compounds in urban aerosols
Atmospheric Research, 2008
Total suspended particles (TSP), collected during June 2002 to July 2003 in Guangzhou, a typical economically developed city in South China, were analyzed for the organic compound compositions using gas chromatography-mass spectrometry (GC/MS). Over 140 organic compounds were detected in the aerosols and grouped into different classes including n-alkanes, hopanoids, polycyclic aromatic hydrocarbons, alkanols, fatty acids, dicarboxylic acids excluding oxalic acid, polyols/polyacids, lignin products, phytosterols, phthalates and water-soluble sugars. The total amounts of the identified organic compounds including unresolved complex mixture (UCM) ranged from 3112 ng/m 3 in spring to 5116 ng/m 3 in winter, comprising on seasonal average 2.8% of TSP. Primary organic compounds peaked in winter although there are no heating systems burning fuels in Guangzhou. The highest saccharide levels occurred in fall due to agricultural activities. This study demonstrated that utilization of fossil fuels, biomass burning, soil resuspension and plastic/refuse burning are the major contributors to the identified organic compounds in the urban atmosphere of South China.
Atmospheric Chemistry and Physics, 2016
Continuous measurements of airborne particles and their chemical compositions were conducted in May, June, October, and November 2014 at an urban site in Wuhan, central China. The results indicate that particle concentrations remained at a relatively high level in Wuhan, with averages of 135.1 ± 4.4 (mean ± 95 % confidence interval) and 118.9 ± 3.7 µg m −3 for PM 10 and 81.2 ± 2.6 and 85.3 ± 2.6 µg m −3 for PM 2.5 in summer and autumn, respectively. Moreover, PM 2.5 levels frequently exceeded the National Standard Level II (i.e., daily average of 75 µg m −3), and six PM 2.5 episodes (i.e., daily PM 2.5 averages above 75 µg m −3 for 3 or more consecutive days) were captured during the sampling campaign. Potassium was the most abundant element in PM 2.5 , with an average concentration of 2060.7 ± 82.3 ng m −3 ; this finding indicates intensive biomass burning in and around Wuhan during the study period, because almost no correlation was found between potassium and mineral elements (iron and calcium). The source apportionment results confirm that biomass burning was the main cause of episodes 1, 3, and 4, with contributions to PM 2.5 of 46.6 % ± 3.0 %, 50.8 % ± 1.2 %, and 44.8 % ± 2.6%, respectively, whereas fugitive dust was the leading factor in episode 2. Episodes 5 and 6 resulted mainly from increases in vehicular emissions and secondary inorganic aerosols, and the mass and proportion of NO − 3 both peaked during episode 6. The high levels of NO x and NH 3 and the low temperature during episode 6 were responsible for the increase of NO − 3. Moreover, the formation of secondary organic carbon was found to be dominated by aromat-ics and isoprene in autumn, and the contribution of aromatics to secondary organic carbon increased during the episodes.
Atmospheric Environment, 2010
Intensive measurements of aerosol (PM 10 ) and associated water-soluble ionic and carbonaceous species were conducted in Guangzhou, a mega city of China, during summer 2006. Elevated levels of most chemical species were observed especially at nighttime during two episodes, characterized by dramatic build-up of the biomass burning tracers levoglucosan and non-sea-salt potassium, when the prevailing wind direction had changed due to two approaching tropical cyclones. High-resolution air mass back trajectories based on the MM5 model revealed that air masses with high concentrations of levoglucosan (43e473 ng m À3 ) and non-sea-salt potassium (0.83e3.2 mg m À3 ) had passed over rural regions of the Pearl River Delta and Guangdong Province, where agricultural activities and field burning of crop residues are common practices. The relative contributions of biomass burning smoke to organic carbon in PM 10 were estimated from levoglucosan data to be on average 7.0 and 14% at daytime and nighttime, respectively, with maxima of 9.7 and 32% during the episodic transport events, indicating that biomass and biofuel burning activities in the rural parts of the Pearl River Delta and neighboring regions could have a significant impact on ambient urban aerosol levels.