The chemical composition and complex refractive index of rural and urban influenced aerosols determined by individual particle analysis

Ebert, Martin; Weinbruch, Stephan; Hoffmann, P.; Ortner, Hugo M.

doi:10.1016/j.atmosenv.2004.08.048

Cited by 125 publications

(101 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…If the C-rich fragments were of biological origin, our observations emphasize that there are abundant biological particles that cannot be detected using only elemental ratios (as used in some computer-controlled SEM/EDX and EPMA studies), and visual observations are needed to separate them from other carbonaceous particles. The proportions of biological particles and C-rich fragments were highest in the coarse size fraction (in PM 1−3.3 samples and especially in PM 3.3−11 samples), which is in line with other individual particle studies related to continental background aerosol composition in Northern Europe (Ebert et al, 2000(Ebert et al, , 2004. No clear difference was observed in the proportions of biological particles and C-rich fragments related to source regions of the air masses.…”

Section: Biological Particles and C-rich Fragmentssupporting

confidence: 73%

“…The net X-ray counts (= total counts -carbon-Formvar blank counts) of elements for each particle analysed were calculated, and their proportions were normalized to 100%. Although the elemental results were semiquantitative, the accuracy is sufficient to identify different particle types and to compare the differences in elemental ratios of the same particle type in different samples (Pósfai et al, 2003;Ebert et al, 2004;Niemi et al, 2005b;Ro et al, 2005;Laskin et al, 2006). The strong vacuum (∼10 −7 torr) and beam exposure causes evaporation of semivolatile compounds from particles, and for that reason, water, ammonium nitrate and organic compounds with high vapour pressure were lost, as is typical in electron microscopy.…”

Section: Tem/edx Individual Particle Analysesmentioning

confidence: 99%

“…Only a few studies on background aerosols in continental Europe have been performed using individual particle methods (Ebert et al, 2002(Ebert et al, , 2004Held et al, 2002;Hinz et al, 2005), and these studies are especially sparse for Northern Europe (Bigg, 2001;Tervahattu et al, 2005). Individual particle methods provide information on chemical composition, sources, morphology and mixing state of particles, which cannot be observed with bulk chemical methods.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Niemi

Saarikoski

Tervahattu³

et al. 2006

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract.Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM 1 ∼16 µg m −3 , backward air mass trajectories from south-east), intermediate period (PM 1 ∼5 µg m −3 , backtrajectories from north-east) and clean period (PM 1 ∼2 µg m −3 , backtrajectories from northwest/north). The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM) coupled with energy dispersive X-ray (EDX) microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM 0.2−1 and PM 1−3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in PM 0.2−1 samples were 1) soot and 2) (ammonium)sulphates and their mixtures with variable amounts of C, K, soot and/or other inclusions. Number proportions of those two particle groups in PM 0.2−1 samples were 0-12% and 83-97%, respectively. During the pollution episode, the proportion of Ca-rich particles was very high (26-48%) in the PM 1−3.3 and PM 3.3−11 samples, while the PM 0.2−1 and PM 1−3.3 samples contained elevated proportions of silicates (22-33%), metal oxides/hydroxides (1-9%) and tar balls (1-4%). These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period, when air masses arrived from the Arctic Ocean, PM 1−3.3 samples contained mainly sea salt particles (67-89%) with a variable rate of Cl substitution (mainly by NO porous (sponge-like) Na-rich particles (35%) with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments (probably also biological origin) were highest in the PM 3.3−11 samples (0-81% and 0-22%, respectively). The origin of different particle types and the effect of aging processes on particle composition and their hygroscopic and optical properties are discussed.

show abstract

Section: Biological Particles and C-rich Fragmentssupporting

confidence: 73%

Section: Tem/edx Individual Particle Analysesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Niemi

Saarikoski

Tervahattu³

et al. 2006

Atmos. Chem. Phys.

View full text Add to dashboard Cite

show abstract

“…The city of Münster is able to reduce its mean concentration of particulate matter with these measures, but this may not be enough to stay below the limit values further on, except if the daily mean concentrations are just above the limit of 50 µg m −3 . Our experimental approach stands in line with other approaches to analyze the sources of PM 10 material in cities representatively: (1) Regional emission sources analyses as done by the State Office for Nature, Environment and Consumer Protection, (2) trace element analysis of bulk material by using ICP-MS (Park and Kim 2005), (3) elemental and morphological analyses of single particles (Ebert et al 2004), (4) twin station data analysis , and (5) time series analyses proved to be successful approaches as well. To our knowledge, there is no city for which all approaches were applied and compared.…”

Section: Resultsmentioning

confidence: 71%

“…Many studies have shown that detailed chemical analysis is a helpful tool in determining the sources of the aerosol impact, e.g., metal or trace element analysis performed by Inductively Coupled Plasma-Mass Spectrometry or Scanning Electron Microscopy (ICP-MS) (Dutkiewicz et al 2006;Ebert et al 2004;Park and Kim 2005). Another approach to source apportionment is the comparison of an urban with a near rural site (Lenschow et al 2001;.…”

Section: Introductionmentioning

confidence: 99%

Source Identification of Size-Segregated Aerosol in Münster, Germany, by Factor Analysis

Gietl

Klemm

2009

Aerosol Science and Technology

View full text Add to dashboard Cite

, and elemental and organic carbon. Positive matrix factorization (PMF) was used for source apportionment where each size class accounted for a single variable. Five factors were identified of which at least four could be found during each season. Traffic, ammonium nitrate, and long distance transport showed a weekly cycle, whereas the factor representing power generation and industrial products seemed to be relatively stable through the week. Sea salt particles were independent of the day of week. The five factors do not only have a similar composition, but also a similar size distribution, throughout all seasons of the year. Particles from long-distance transport were identified in the accumulation mode while PM originating from power generation were characterized by a larger diameter. Sea salt aerosol consisted mainly of coarse particles, ammonium nitrate is mainly found in the largest size fraction. Even without a detailed chemical trace elements analysis, precise PM source apportionment was accomplished.

show abstract

Effect of heterogeneity and shape on optical properties of urban dust based on three‐dimensional modeling of individual particles

Conny

Ortiz-Montalvo

2017

JGR Atmospheres

View full text Add to dashboard Cite

We show the effect of composition heterogeneity and shape on the optical properties of urban dust particles based on the three‐dimensional spatial and optical modeling of individual particles. Using scanning electron microscopy/energy‐dispersive X‐ray spectroscopy (SEM/EDX) and focused ion beam (FIB) tomography, spatial models of particles collected in Los Angeles and Seattle accounted for surface features, inclusions, and voids, as well as overall composition and shape. Using voxel data from the spatial models and the discrete dipole approximation method, we report extinction efficiency, asymmetry parameter, and single‐scattering albedo (SSA). Test models of the particles involved (1) the particle's actual morphology as a single homogeneous phase and (2) simple geometric shapes (spheres, cubes, and tetrahedra) depicting composition homogeneity or heterogeneity (with multiple spheres). Test models were compared with a reference model, which included the particle's actual morphology and heterogeneity based on SEM/EDX and FIB tomography. Results show particle shape to be a more important factor for determining extinction efficiency than accounting for individual phases in a particle, regardless of whether absorption or scattering dominated. In addition to homogeneous models with the particles' actual morphology, tetrahedral geometric models provided better extinction accuracy than spherical or cubic models. For iron‐containing heterogeneous particles, the asymmetry parameter and SSA varied with the composition of the iron‐containing phase, even if the phase was <10% of the particle volume. For particles containing loosely held phases with widely varying refractive indexes (i.e., exhibiting “severe” heterogeneity), only models that account for heterogeneity may sufficiently determine SSA.

show abstract

The chemical composition and complex refractive index of rural and urban influenced aerosols determined by individual particle analysis

Cited by 125 publications

References 42 publications

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Source Identification of Size-Segregated Aerosol in Münster, Germany, by Factor Analysis

Effect of heterogeneity and shape on optical properties of urban dust based on three‐dimensional modeling of individual particles

Contact Info

Product

Resources

About