scholarly journals Correction to “Quantitative sampling using an Aerodyne aerosol mass spectrometer: 2. Measurements of fine particulate chemical composition in two U.K. cities,”

2003 ◽  
Vol 108 (D9) ◽  
pp. n/a-n/a ◽  
Author(s):  
James D. Allan ◽  
M. Rami Alfarra ◽  
Keith N. Bower ◽  
Paul I. Williams ◽  
Martin W. Gallagher ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Aerosol Mass Spectrometer ◽  
Quantitative Sampling ◽  
Aerosol Mass ◽  
Fine Particulate

Quantitative sampling using an Aerodyne aerosol mass spectrometer 2. Measurements of fine particulate chemical composition in two U.K. cities

2003 ◽  
Vol 108 (D3) ◽  
pp. n/a-n/a ◽  
Author(s):  
James D. Allan ◽  
M. Rami Alfarra ◽  
Keith N. Bower ◽  
Paul I. Williams ◽  
Martin W. Gallagher ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Aerosol Mass Spectrometer ◽  
Quantitative Sampling ◽  
Aerosol Mass ◽  
Fine Particulate

scholarly journals CHEMICAL COMPOSITION OF AEROSOLS IN THE WEST COAST OF TAIWAN STRAIT, CHINA

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 233-237
Author(s):  
L. Zhao ◽  
C. Yang
Keyword(s):  
Chemical Composition ◽  
Mass Spectrometer ◽  
Single Particle ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Ion Concentration ◽  
Aerosol Mass Spectrometer ◽  
Average Mass ◽  
Inorganic Ion ◽  
Aerosol Mass

Abstract. The chemical composition of aerosols was investigated using regular environmental air quality observation, a single particle aerosol mass spectrometer (SPAMS 0515) and an ambient ion monitor (URG 9000D) in Xiamen in 2018. The results showed that the annual average mass concentrations of PM2.5 was 22 μm/m3, and concentrations of water-soluble inorganic ions was 9.94 μm/m3 which accounted for 45.2% of PM2.5. SO42−, NO3− and NH4+ were main components of secondary reactions which contributed more than 77 percent of water-soluble inorganic ion concentration. As a coastal city, Cl− and Na+ contributed 13.9 percent of water-soluble inorganic ion concentration. Based on single particle aerosol mass spectrometer analysing, mobile sources emission was the most important sources of particle matter which contributed over 30%.

scholarly journals A missing source of aerosols in Antarctica – beyond long-range transport, phytoplankton, and photochemistry

2017 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Michael R. Giordano ◽  
Lars E. Kalnajs ◽  
Anita Avery ◽  
J. Douglas Goetz ◽  
Sean M. Davis ◽  
...  
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Real Time ◽  
Mass Spectrometer ◽  
Formation Mechanisms ◽  
Second Phase ◽  
Austral Spring ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
The Antarctic

Abstract. Understanding the sources and evolution of aerosols is crucial for constraining the impacts that aerosols have on a global scale. An unanswered question in atmospheric science is the source and evolution of the Antarctic aerosol population. Previous work over the continent has primarily utilized low temporal resolution aerosol filters to answer questions about the chemical composition of Antarctic aerosols. Bulk aerosol sampling has been useful in identifying seasonal cycles in the aerosol populations, especially in populations that have been attributed to Southern Ocean phytoplankton emissions. However, real-time, high-resolution chemical composition data are necessary to identify the mechanisms and exact timing of changes in the Antarctic aerosol. The recent 2ODIAC (2-Season Ozone Depletion and Interaction with Aerosols Campaign) field campaign saw the first ever deployment of a real-time, high-resolution aerosol mass spectrometer (SP-AMS – soot particle aerosol mass spectrometer – or AMS) to the continent. Data obtained from the AMS, and a suite of other aerosol, gas-phase, and meteorological instruments, are presented here. In particular, this paper focuses on the aerosol population over coastal Antarctica and the evolution of that population in austral spring. Results indicate that there exists a sulfate mode in Antarctica that is externally mixed with a mass mode vacuum aerodynamic diameter of 250 nm. Springtime increases in sulfate aerosol are observed and attributed to biogenic sources, in agreement with previous research identifying phytoplankton activity as the source of the aerosol. Furthermore, the total Antarctic aerosol population is shown to undergo three distinct phases during the winter to summer transition. The first phase is dominated by highly aged sulfate particles comprising the majority of the aerosol mass at low wind speed. The second phase, previously unidentified, is the generation of a sub-250 nm aerosol population of unknown composition. The second phase appears as a transitional phase during the extended polar sunrise. The third phase is marked by an increased importance of biogenically derived sulfate to the total aerosol population (photolysis of dimethyl sulfate and methanesulfonic acid (DMS and MSA)). The increased importance of MSA is identified both through the direct, real-time measurement of aerosol MSA and through the use of positive matrix factorization on the sulfur-containing ions in the high-resolution mass-spectral data. Given the importance of sub-250 nm particles, the aforementioned second phase suggests that early austral spring is the season where new particle formation mechanisms are likely to have the largest contribution to the aerosol population in Antarctica.

scholarly journals Aqueous phase processing of secondary organic aerosols

2011 ◽  
Vol 11 (7) ◽  
pp. 21489-21532 ◽  
Author(s):  
◽  
T. Tritscher ◽  
A. P. Praplan ◽  
P. F. DeCarlo ◽  
B. Temime-Roussel ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Aqueous Phase ◽  
Mass Spectrometer ◽  
Atmospheric Pressure ◽  
Smog Chamber ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Volatile Organic ◽  
On Line ◽  
Physical And Chemical

Abstract. The aging of secondary organic aerosol (SOA) by photooxidation in the aqueous phase was experimentally investigated. To simulate multiphase processes, the following experiments were sequentially performed in a smog chamber and in an aqueous phase photoreactor: (1) Gas-phase photooxidation of three different volatile organic compounds (VOC): isoprene, α-pinene, and 1,3,5-trimethylbenzene (TMB) in the presence of NOx, leading to the formation of SOA which was subjected to on-line physical and chemical analysis; (2) particle-to-liquid transfer of water soluble species of SOA using filter sampling and aqueous extraction; (3) aqueous-phase photooxidation of the obtained water extracts; and (4) nebulization of the solutions for a repetition of the on-line characterization. SOA concentrations in the chamber measured with a scanning mobility particle sizer (SMPS) were higher than 200 μg m−3, as the experiments were conducted under high initial concentrations of volatile organic compounds (VOC) and NOx. The aging of SOA through aqueous phase processing was investigated by measuring the physical and chemical properties of the particles online before and after processing using a high resolution time-of-flight aerosol mass spectrometer (AMS) and a hygroscopicity tandem differential mobility analyzer (H-TDMA). It was shown that, after aqueous phase processing, the particles were significantly more hygroscopic, and contained more fragmentation ions at m/z = 44 and less ions at m/z = 43, thus showing a significant impact on SOA aging for the three different precursors. Additionally, the particles were analyzed with a thermal desorption atmospheric pressure ionization aerosol mass spectrometer (TD-API-AMS). Comparing the smog chamber SOA composition and non processed nebulized aqueous extracts with this technique revealed that sampling, extraction and/or nebulization did not significantly impact the chemical composition of SOA formed from isoprene and α-pinene, whereas it affected that formed from TMB. For the two first precursors, the aqueous phase chemical composition of SOA was further investigated using offline measurements, i.e. ion chromatography coupled to a mass spectrometer (IC-MS) and an atmospheric pressure chemical ionization mass spectrometer (APCI-MS) equipped with high pressure liquid chromatography (HPLC-MS). These analyses showed that aqueous phase processing enhanced the formation of some compounds already present in the SOA, thus confirming the aging effect of aqueous phase processes. For isoprene experiments, additional new compounds, likely oligomers, were formed through aqueous phase photooxidation, and their possible origins are discussed.

scholarly journals Single particle measurements of bouncing particles and in-situ collection efficiency from an airborne aerosol mass spectrometer (AMS) with light scattering detection

2017 ◽  
Author(s):  
Jin Liao ◽  
Charles A. Brock ◽  
Daniel M. Murphy ◽  
Donna T. Sueper ◽  
André Welti ◽  
...  
Keyword(s):  
Light Scattering ◽  
Chemical Composition ◽  
Mass Spectrometer ◽  
Mass Spectra ◽  
Collection Efficiency ◽  
Particle Mass ◽  
Aerodynamic Diameter ◽  
Aerosol Mass Spectrometer ◽  
Mass Spectral ◽  
Aerosol Mass

Abstract. A light scattering module was coupled to an airborne, compact time-of-flight aerosol mass spectrometer (LS-ToF-AMS) to investigate collection efficiency (CE) while obtaining non-refractory aerosol chemical composition measurements during the Southeast Nexus (SENEX) campaign. In this instrument, particles typically larger than ~ 250 nm in vacuum aerodynamic diameter scatter light from an internal laser beam and trigger saving individual particle mass spectra. Over 33,000 particles are characterized as either prompt (27 %), delayed (15 %), or null (58 %), according to the appearance time and intensity of their mass spectral signals. The individual particle mass from the spectra is proportional to the mass derived from the vacuum aerodynamic diameter determined by the light scattering signals (dva-LS) rather than the traditional particle time-of-flight (PToF) size (dva). The delayed particles capture about 80 % of the total chemical mass compared to prompt ones. Both field and laboratory data indicate that the relative intensities of various ions in the prompt spectra show more fragmentation compared to the delayed spectra. The particles with a delayed mass spectral signal likely bounced on the vaporizer and vaporized later on a lower temperature surface within the confines of the ionization source. Because delayed particles are detected at a later time by the mass spectrometer than expected, they can affect the interpretation of PToF mass distributions especially at the larger sizes. CE, measured by the average number or mass fractions of particles optically detected that have measureable mass spectra, varied significantly (0.2–0.9) in different air masses. Relatively higher null fractions and corresponding lower CE for this study may have been related to the lower sensitivity of the AMS during SENEX. The measured CE generally agreed with the CE parameterization based on ambient chemical composition, including for acidic particles that had a higher CE as expected from previous studies.

scholarly journals Spatial variation of chemical composition and sources of submicron aerosol in Zurich: factor analysis of mobile aerosol mass spectrometer data

2011 ◽  
Vol 11 (4) ◽  
pp. 12323-12365 ◽  
Author(s):  
C. Mohr ◽  
R. Richter ◽  
P. F. DeCarlo ◽  
A. S. H. Prévôt ◽  
U. Baltensperger
Keyword(s):  
Air Pollution ◽  
Chemical Composition ◽  
Spatial Variation ◽  
Mass Spectrometer ◽  
Organic Aerosol ◽  
Aerosol Mass Spectrometer ◽  
Aerosol Mass ◽  
Regional Background ◽  
Mobile Measurements ◽  
The City

Abstract. Mobile measurements of PM1 (PM with an aerodynamic diameter D<1 μm) chemical composition using a quadrupole aerosol mass spectrometer and a multi-angle absorption photometer were performed using the PSI mobile laboratory during winter 2007/2008 and December 2008 in the metropolitan area of Zurich, Switzerland. Positive matrix factorization (PMF) applied to the organic fraction of PM1 yielded 3 factors: Hydrocarbon-like organic aerosol (HOA) related to traffic emissions; organic aerosol from wood burning for domestic heating purposes (WBOA); and oxygenated organic aerosol (OOA), assigned to secondary organic aerosol formed by oxidation of volatile precursors. The spatial variation of the chemical composition of PM1 shows a uniform distribution throughout the city: for primary emissions, road traffic is important along major roads (varying between 7 and 14% of PM1 for different sites within the city), but overall, domestic wood burning is more important for the organic aerosol concentrations in Zurich during winter time (varying between 8–15% of PM1 for different sites within the city). OOA makes up the largest fraction of organic aerosol (44% on average). A new method, based on simultaneous on-road mobile and stationary background measurements and using the ratio of on-road sulfate to stationary sulfate to correct for small-scale dynamic effects, allows for the separation of PM1 emitted or produced locally and the PM1 from the regional background. It could be shown that especially during thermal inversions over the Swiss plateau, regional background concentrations contribute substantially to particulate number concentrations (60% on average) as well as to the concentrations of PM1 components (on average 60% for black carbon and HOA, over 97% for WBOA and OOA, and more than 94% for the measured inorganic components) in downtown Zurich. The results emphasize, on a scientific level, the advantage of mobile measurements for distinguishing local from regional air pollution, and on a political level, the importance of regional collaboration for mitigating air pollution issues.

Sign in / Sign up

Export Citation Format

Share Document