Investigation of the Chemical Mixing State of Individual Asian Dust Particles by the Combined Use of Electron Probe X-ray Microanalysis and Raman Microspectrometry

2012 ◽  
Vol 84 (7) ◽  
pp. 3145-3154 ◽  
Author(s):  
Sophie Sobanska ◽  
HeeJin Hwang ◽  
Marie Choël ◽  
Hae-Jin Jung ◽  
Hyo-Jin Eom ◽  
...  
Keyword(s):  
Electron Probe ◽  
Asian Dust ◽  
Dust Particles ◽  
Mixing State ◽  
X Ray ◽  
Combined Use ◽  
Chemical Mixing ◽  
Raman Microspectrometry

Iron Speciation of Airborne Subway Particles by the Combined Use of Energy Dispersive Electron Probe X-ray Microanalysis and Raman Microspectrometry

2013 ◽  
Vol 85 (21) ◽  
pp. 10424-10431 ◽  
Author(s):  
Hyo-Jin Eom ◽  
Hae-Jin Jung ◽  
Sophie Sobanska ◽  
Sang-Gwi Chung ◽  
Youn-Suk Son ◽  
...  
Keyword(s):  
Electron Probe ◽  
Energy Dispersive ◽  
Iron Speciation ◽  
X Ray ◽  
Combined Use ◽  
Raman Microspectrometry

scholarly journals Effect of chemical mixing state on the hygroscopicity and cloud nucleation properties of calcium mineral dust particles

2009 ◽  
Vol 9 (1) ◽  
pp. 2609-2644 ◽  
Author(s):  
R. C. Sullivan ◽  
M. J. K. Moore ◽  
M. D. Petters ◽  
S. M. Kreidenweis ◽  
G. C. Roberts ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Calcium Oxalate ◽  
Calcium Sulfate ◽  
Mineral Dust ◽  
Cloud Condensation Nuclei ◽  
Calcium Nitrate ◽  
Asian Dust ◽  
Dust Particles ◽  
Mixing State ◽  
Chemical Mixing

Abstract. Atmospheric mineral dust particles can alter cloud properties and thus climate by acting as cloud condensation nuclei (CCN) that form cloud droplets. The CCN activation properties of various calcium mineral dust particles were studied experimentally to investigate the consequences of field observations showing the segregation of sulfate from nitrate and chloride between individual aged Asian dust particles, and the enrichment of oxalic acid in Asian dust. Each mineral's observed apparent hygroscopicity was primarily controlled by its solubility, which determines the degree to which the mineral's intrinsic hygroscopicity can be expressed. The significant increase in hygroscopicity caused by mixing soluble hygroscopic material with insoluble mineral particles is also presented. Insoluble minerals including calcium carbonate, representing fresh unprocessed dust, and calcium sulfate, representing atmospherically processed dust, had similarly small apparent hygroscopicities. Their activation is accurately described by a deliquescence limit following the Kelvin effect and corresponded to an apparent single-hygroscopicity parameter, κ, of ~0.001. Soluble calcium chloride and calcium nitrate, representing atmospherically processed mineral dust particles, were much more hygroscopic, activating similar to ammonium sulfate with κ~0.5. Calcium oxalate monohydrate (κ=0.05) was significantly less CCN-active than oxalic acid (κ=0.3), but not as inactive as its low solubility would predict. These results indicate that the common assumption that all mineral dust particles become more hygroscopic and CCN-active after atmospheric processing should be revisited. Calcium sulfate and calcium oxalate are two realistic proxies for aged mineral dust that remain non-hygroscopic. The dust's apparent hygroscopicity will be controlled by its chemical mixing state, which is determined by its mineralogy and the chemical reaction pathways it experiences during transport.

scholarly journals Effect of chemical mixing state on the hygroscopicity and cloud nucleation properties of calcium mineral dust particles

2009 ◽  
Vol 9 (10) ◽  
pp. 3303-3316 ◽  
Author(s):  
R. C. Sullivan ◽  
M. J. K. Moore ◽  
M. D. Petters ◽  
S. M. Kreidenweis ◽  
G. C. Roberts ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Calcium Oxalate ◽  
Mineral Dust ◽  
Cloud Condensation Nuclei ◽  
Calcium Nitrate ◽  
Calcium Sulphate ◽  
Asian Dust ◽  
Dust Particles ◽  
Mixing State ◽  
Chemical Mixing

Abstract. Atmospheric mineral dust particles can alter cloud properties and thus climate by acting as cloud condensation nuclei (CCN) that form cloud droplets. The CCN activation properties of various calcium mineral dust particles were studied experimentally to investigate the consequences of field observations showing the segregation of sulphate from nitrate and chloride between individual aged Asian dust particles, and the enrichment of oxalic acid in Asian dust. Each mineral's observed apparent hygroscopicity was primarily controlled by its solubility, which determines the degree to which the mineral's intrinsic hygroscopicity can be expressed. The significant increase in hygroscopicity caused by mixing soluble hygroscopic material with insoluble mineral particles is also presented. Insoluble minerals including calcium carbonate, representing fresh unprocessed dust, and calcium sulphate, representing atmospherically processed dust, had similarly small apparent hygroscopicities. Their activation is accurately described by a deliquescence limit following the Kelvin effect and corresponded to an apparent single-hygroscopicity parameter, κ, of ~0.001. Soluble calcium chloride and calcium nitrate, representing atmospherically processed mineral dust particles, were much more hygroscopic, activating similar to ammonium sulphate with κ~0.5. Calcium oxalate monohydrate (κ=0.05) was significantly less CCN-active than oxalic acid (κ=0.3), but not as inactive as its low solubility would predict. These results indicate that the common assumption that all mineral dust particles become more hygroscopic and CCN-active after atmospheric processing should be revisited. Calcium sulphate and calcium oxalate are two realistic proxies for aged mineral dust that remain non-hygroscopic. The dust's apparent hygroscopicity will be controlled by its chemical mixing state, which is determined by its mineralogy and the chemical reaction pathways it experiences during transport.

Single-Particle Characterization of Four “Asian Dust” Samples Collected in Korea, Using Low-ZParticle Electron Probe X-ray Microanalysis

2005 ◽  
Vol 39 (6) ◽  
pp. 1409-1419 ◽  
Author(s):  
Chul-Un Ro ◽  
HeeJin Hwang ◽  
HyeKyeong Kim ◽  
Youngsin Chun ◽  
René Van Grieken
Keyword(s):  
Single Particle ◽  
Electron Probe ◽  
Asian Dust ◽  
Particle Characterization ◽  
X Ray

scholarly journals Observation of chemical modification of Asian Dust particles during long-range transport by the combined use of quantitative ED-EPMA and ATR-FT-IR imaging

2012 ◽  
Vol 12 (10) ◽  
pp. 27297-27331 ◽  
Author(s):  
Young-Chul Song ◽  
Hyo-Jin Eom ◽  
Hae-Jin Jung ◽  
Md Abdul Malek ◽  
HyeKyeong Kim ◽  
...  
Keyword(s):  
Chemical Modification ◽  
Analytical Techniques ◽  
Asian Dust ◽  
Sea Salt ◽  
Dust Particles ◽  
Long Range Transport ◽  
Combined Use ◽  
Range Transport ◽  
Ft Ir ◽  
Individual Particles

Abstract. In our previous works, it was demonstrated that the combined use of quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), which is also known as low-Z particle EPMA, and attenuated total reflectance FT-IR (ATR-FT-IR) imaging has great potential for a detailed characterization of individual aerosol particles. In this study, individual Asian Dust particles collected during an Asian Dust storm event on 11 November 2011 in Korea were characterized by the combined use of low-Z particle EPMA and ATR-FT-IR imaging. The combined use of the two single-particle analytical techniques on the same individual particles showed that Asian Dust particles had experienced extensive chemical modification during long-range transport. Overall, 109 individual particles were classified into four particle types based on their morphology, elemental concentrations, and molecular species and/or functional groups of individual particles available from the two analytical techniques: Ca-containing (38%); NaNO3-containing (30%); silicate (22%); and miscellaneous particles (10%). Among the 41 Ca-containing particles, 10, 8, and 14 particles contained nitrate, sulfate, and both, respectively, whereas only two particles contained unreacted CaCO3. Airborne amorphous calcium carbonate (ACC) particles were observed in this Asian Dust sample for the first time, where their IR peaks for the insufficient symmetric environment of CO32− ions of ACC were clearly differentiated from those of crystalline CaCO3. This paper also reports the field observations of CaCl2 particles converted from CaCO3 for the Asian Dust sample collected in the planetary boundary layer. Thirty three particles contained NaNO3, which are the reaction products of sea-salt and NOx/HNO3, whereas no genuine sea-salt particles were encountered, indicating that sea-salt particles are more reactive than CaCO3 particles. Some silicate particles were observed to contain nitrate, sulfate, and water. Among 24 silicate particles, 10 particles contained water, the presence of which could facilitate atmospheric heterogeneous reactions of silicate particles including swelling minerals, such as montmorillonite and vermiculite, and non-swelling ones, such as feldspar and quartz. This paper provides detailed information on the physicochemical characteristics of individual Asian Dust particles that experienced extensive chemical modification during long-range transport through the combined use of the two single-particle analytical techniques.

Use of the Soft X-Ray Spectrograph and the Electron-Probe Microanalyzer for Determination of Elements Carbon Through Iron in Minerals and Rocks

1965 ◽  
Vol 9 ◽  
pp. 487-503
Author(s):  
A. K. Baird ◽  
D. H. Zenger
Keyword(s):  
High Precision ◽  
Electron Probe ◽  
Bulk Composition ◽  
Major Elements ◽  
Major Constituent ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Minor Elements ◽  
Combined Use ◽  
Sodium Magnesium

AbstractThe major elements m common rocks are of low atomic number, but analyses of high precision are possible by soft X-ray spectrography if several grams of rock sample are available. The electron-probe microanalyzer is shown to complement this established method by permitting analyses of particles as small as 1 μ in diameter. This paper describes applications of these methods to the analysis of the major and minor elements of silicate, carbonate, and phosphate minerals and rocks.Elements of particular interest are as follows : carbon in particles enclosed in carbonate rocks; oxygen, as the major constituent of the specimens; phosphorus in phosphatic nodules and apatites; manganese and iron, as colorations in fossil shells; and the group oxygen, sodium, magnesium, aluminum, silicon, potassium, calcium, and iron as complex segregations and zonations within single crystals of several mineral phases.If the bulk composition of a rock is known, and also the chemistry of the constituent minerals, it is possible to compute quantitative minéralogie analyses of high precision. Thus, the combined use of soft X-ray spectrography and electronprobe microanalysis can provide quantitative chemical and mineralogicat information on the earth's crust on all scales from thousands of square miles (by means of appropriate sampling) down to the scale of 1 μ.

scholarly journals Chemistry and mineralogy of clay minerals in Asian and Saharan dusts and the implications for iron availability

2014 ◽  
Vol 14 (11) ◽  
pp. 15735-15770 ◽  
Author(s):  
G. Y. Jeong ◽  
E. P. Achterberg
Keyword(s):  
Chemical Analysis ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Mineral Dust ◽  
Ion Beam ◽  
Asian Dust ◽  
Saharan Dust ◽  
Dust Particles ◽  
X Ray ◽  
Fe Content

Abstract. Mineral dust supplied to remote ocean regions stimulates phytoplankton growth through delivery of micronutrients, notably iron (Fe). Although attention is usually paid to Fe (hydr)oxides as major sources of available Fe, Fe-bearing clay minerals are typically the dominant phase in mineral dust. The mineralogy and chemistry of clay minerals in dust particles, however, are largely unknown. We conducted microscopic identification and chemical analysis of the clay minerals in Asian and Saharan dust particles. Cross-sectional slices of dust particles were prepared by focused ion beam (FIB) techniques and analyzed by transmission electron microscopy (TEM) combined with energy dispersive X-ray spectroscopy (EDXS). TEM images of FIB slices revealed that clay minerals occurred as either nano-thin platelets or relatively thick plates. The nano-thin platelets included illite, smectite, illite–smectite mixed layers and their nanoscale mixtures (illite–smectite series clay minerals, ISCMs) which could not be resolved with an electron microbeam. EDXS chemical analysis of the clay mineral grains revealed that the average Fe content was 5.8% in nano-thin ISCM platelets assuming 14% H2O, while the Fe content of illite and chlorite was 2.8 and 14.8%, respectively. In addition, TEM and EDXS analyses were performed on clay mineral grains dispersed and loaded on microgrids. The average Fe content of clay mineral grains was 6.7 and 5.4% in Asian and Saharan dusts, respectively. A comparative X-ray diffraction analysis of bulk dusts showed that Saharan dust was more enriched in clay minerals than in Asian dust, while Asian dust was more enriched in chlorite. The average Fe / Si, Al / Si and Fe / Al molar ratios of the clay minerals, compared to previously reported chemistries of mineral dusts and leached solutions, indicated that dissolved Fe originated from clay minerals. Clay minerals, in particular nanocrystalline ISCMs and Fe-rich chlorite are important sources of available Fe in remote marine ecosystems. Further detailed analyses of the mineralogy and chemistry of clay minerals in global aerosols are required to determine the inputs of Fe available to surface ocean microbial communities.

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