Water-soluble part of the aerosol in the dust storm season—evidence of the mixing between mineral and pollution aerosols

Background: The genus Verbascum is well documented for its antioxidant potential but Verbascum sinaiticum is comparatively less studied plant. The current study was carried out to search for antioxidant nutraceuticals from this species. Objective: To explore the antioxidant potential of Verbascum sinaiticum and to identify its active constituents. Methods: The methanolic extract of air-dried aerial part of the Verbascum sinaiticum was partitioned with hexane, chloroform and ethyl acetate. The water-soluble part of ethyl acetate afforded six phenylethanoid glycosides by repeated chromatography over Sephadex LH-20, silica gel and ODS columns. Antioxidant activity of solvent extracts and isolated constituents were evaluated by DPPH, ABTS and FRAP assays. Results: Six phenylethanoid glycosides was isolated and characterized as Verbascoside, Eukovoside, Martynoside, Jionoside D, Campneoside I and Campneoside II, from the most active fraction. Conclusion: Verbascum sinaiticum demonstrated prospective antioxidant activity. The watersoluble part of EtOAc (WSEAE) was found the most active extract whereas Verbascoside was identified as the most potent constituent. All isolated compounds exhibited significant antioxidant activity whereas their synergistic effect was found prominent in the parent fraction.

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Increases in the formation of water soluble organic nitrogen during Asian dust storm episodes

Atmospheric Research ◽

10.1016/j.atmosres.2021.105486 ◽

2021 ◽

Vol 253 ◽

pp. 105486

Author(s):

Qingyang Liu ◽

Yanjiu Liu ◽

Qiang Zhao ◽

Tingting Zhang ◽

James J. Schauer

Keyword(s):

Dust Storm ◽

Organic Nitrogen ◽

Asian Dust ◽

Water Soluble ◽

Asian Dust Storm ◽

Soluble Organic Nitrogen

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Depolymerization of Straw Lignin by Manganese Peroxidase from Nematoloma frowardii is Accompanied by Release of Carbon Dioxide

Holzforschung ◽

10.1515/hf.1999.027 ◽

1999 ◽

Vol 53 (2) ◽

pp. 161-166 ◽

Cited By ~ 21

Author(s):

Martin Hofrichter ◽

Katrin Scheibner ◽

Friedemann Bublitz ◽

Ivonne Schneegaß ◽

Dirk Ziegenhagen ◽

...

Keyword(s):

Carbon Dioxide ◽

Manganese Peroxidase ◽

Gel Permeation Chromatography ◽

Water Soluble ◽

White Rot ◽

White Rot Fungus ◽

Lignin Fraction ◽

Molecular Masses ◽

Total Lignin ◽

Soluble Part

SummaryManganese peroxidase preparations (MnP) from the white-rot fungusNematoloma frowardiiwere able to release14CO2directly from14C-labeled milled wheat straw (MWS; total lignin fraction) and milled straw lignin (MSL; dioxane soluble part of MWS). Apart from the formation of14CO2(4–10 %) the treatment of insoluble MWS and MSL with MnP resulted in the formation of water-soluble14C-lignin fragments (lignin solubilization, 14–25%). Analyses with gel permeation chromatography (GPC) demonstrated the formation of lignin fragments with predominant molecular masses around 1 kDa. The extent of MWS mineralization and solubilization was enhanced in the presence of reduced glutathione (GSH) acting as thiol mediator, whereas MSL mineralization was not stimulated by GSH. The principle of direct extracellular mineralization of lignin catalyzed by the MnP system may make a significant contribution to the formation of carbon dioxide in lignincellulose containing habitats.

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Investigation of aged aerosols in size-resolved Asian dust storm particles transported from Beijing, China to Incheon, Korea using low-<i>Z</i> particle EPMA

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-27971-2013 ◽

2013 ◽

Vol 13 (10) ◽

pp. 27971-28016 ◽

Cited By ~ 1

Author(s):

H. Geng ◽

H. J. Hwang ◽

X. Liu ◽

S. Dong ◽

C.-U. Ro

Keyword(s):

Organic Carbon ◽

Dust Storm ◽

Aging Process ◽

Mineral Dust ◽

Asian Dust ◽

Sea Salt ◽

Water Soluble ◽

The Yellow Sea ◽

Asian Dust Storm ◽

Beijing China

Abstract. This is the first study of Asian dust storm (ADS) particles collected in Beijing, China and Incheon, Korea during the same spring ADS event. Using a seven-stage May impactor and a quantitative electron probe X-ray microanalysis (ED-EPMA, also known as low-Z particle EPMA), we examined the composition and morphology of 4200 aerosol particles at stages 1–6 (with a size cut-off of 16, 8, 4, 2, 1, and 0.5 μm in equivalent aerodynamic diameter, respectively) collected during an ADS event on 28–29 April 2005. The results showed that there were large differences in the chemical compositions between particles in sample S1 collected in Beijing immediately after the peak time of the ADS and in samples S2 and S3, which were collected in Incheon approximately 5 h and 24 h later, respectively. In sample S1, mineral dust particles accounted for more than 88% in relative number abundance at stages 1–5, and organic carbon (OC) and reacted NaCl-containing particles accounted for 24% and 32%, respectively, at stage 6. On the other hand, in samples S2 and S3, in addition to approximately 60% mineral dust, many sea salt particles reacted with airborne SO2 and NOx, often mixed with mineral dust, were encountered at stages 1–5, and (C, N, O, S)-rich particles (likely a mixture of water-soluble organic carbon with (NH4)2SO4 and NH4NO3) and K-containing particles were abundantly observed at stage 6. This suggests that the secondary aerosols and the internal mixture of mineral dust with sea spray aerosol increased when the ADS particles passed over the Yellow Sea. In the reacted or aged mineral dust and sea salt particles, nitrate-containing and both nitrate- and sulfate-containing species vastly outnumbered the sulfate-containing species, implying that ambient nitrogen oxides had a greater influence on the atmospheric particles during the ADS episode than SO2. In addition to partially- or totally-reacted CaCO3, reacted or aged Mg-containing aluminosilicates (likely including amesite, allophite, vermiculite, illite, and montmorillonite) were observed frequently in samples S2 and S3; and furthermore, both the atomic concentration ratios of [Mg]/[Al] and [Mg]/[Si] were elevated compared to that in sample S1. This shows that a great evolution or aging process must have occurred on the mineral dust. This indicates that the number abundance, reactivity with gaseous pollutants, and ratios of [Mg]/[Al] and [Mg]/[Si] of Mg-containing aluminosilicates are promising indices of the aging process of ADS particles during long-range transport.

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Evolution of aerosol chemistry in Xi'an, inland China during the dust storm period of 2013 – Part 1: Sources, chemical forms and formation mechanisms of nitrate and sulfate

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-17439-2014 ◽

2014 ◽

Vol 14 (11) ◽

pp. 17439-17478

Author(s):

G. H. Wang ◽

Y. Huang ◽

J. Tao ◽

Y. Q. Ren ◽

F. Wu ◽

...

Keyword(s):

Loess Plateau ◽

Dust Storm ◽

Water Soluble ◽

Current Work ◽

Ageing Process ◽

Gobi Desert ◽

Chemical Compositions ◽

Aerosol Chemistry ◽

Coarse Mode ◽

Fine Mode

Abstract. In the current work TSP sample was hourly collected in Xi'an, an inland mega-city of China near the Loess Plateau, during a dust storm event of 2013 (9 March 18:00–12 March 10:00 LT), along with a size-resolved aerosol sampling and an online measurement of PM2.5. The TSP and size-resolved samples were determined for EC, OC, water-soluble organic carbon (WSOC) and nitrogen (WSON), inorganic ions and elements to investigate aerosol chemistry evolution. Hourly concentrations of Cl−, NO3−, SO42−, Na+ and Ca2+ in the TSP samples reached up to 34, 12, 180, 72 and 28 μg m−3, respectively, when dust peak arrived over Xi'an. Chemical compositions of the TSP samples showed that NH4+ and NO3− strongly correlated each other in the whole observation period (r2=0.76), while SO42− and Cl− well correlated with Na+, Ca2+, Mg2+ and K+ (r2>0.85). Size distributions of NH4+ and NO3− presented a same pattern, which dominated in the coarse mode (>2.1 μm during the event and predominated in the fine mode (<2.1 μm) during the non-event. SO42− and Cl− also dominated in the coarse mode during the event, but both exhibited two equivalent peaks in the fine and coarse modes during the non-event, respectively, due to the fine mode accumulations of secondarily produced SO42− and biomass burning emitted Cl− and the coarse mode enrichments of urban soil-derived SO42− and Cl−. Linear fit regression analysis further indicated that SO42− and Cl− in the dust samples possibly exist as Na2SO4, CaSO4 and NaCl, which directly originated from Gobi desert surface soil, while NH4+ and NO3− in the dust samples exist as NH4NO3. We propose a mechanism to explain these observations in which aqueous phase of dust particle surface is formed via uptake of water vapor by hygroscopic Na2SO4, CaSO4 and NaCl, followed by heterogeneous formation of nitrate on the liquid phase and subsequent absorption of ammonia. Our data indicate that 54 ± 20% and 60 ± 23% of NH4+ and NO3− during the dust period were secondarily produced via this pathway with the remaining derived from Gobi desert and Loess Plateau while SO42− in the event almost entirely originated from the source regions. To the best of our knowledge, the current work for the first time revealed an infant state of dust ageing process in the regions near the source, which is helpful for researchers to understand the panorama of dust ageing process from the source area to the downwind region.

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Investigation of aged aerosols in size-resolved Asian dust storm particles transported from Beijing, China, to Incheon, Korea, using low-<i>Z</i> particle EPMA

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-3307-2014 ◽

2014 ◽

Vol 14 (7) ◽

pp. 3307-3323 ◽

Cited By ~ 19

Author(s):

H. Geng ◽

H. Hwang ◽

X. Liu ◽

S. Dong ◽

C.-U. Ro

Keyword(s):

Organic Carbon ◽

Dust Storm ◽

Mineral Dust ◽

Asian Dust ◽

Water Soluble ◽

The Yellow Sea ◽

Dust Particles ◽

Chemical Compositions ◽

Asian Dust Storm ◽

Beijing China

Abstract. This is the first study of Asian dust storm (ADS) particles collected in Beijing, China, and Incheon, Korea, during a spring ADS event. Using a seven-stage May impactor and a quantitative electron probe X-ray microanalysis (ED-EPMA, also known as low-Z particle EPMA), we examined the composition and morphology of 4200 aerosol particles at stages 1–6 (with a size cut-off of 16, 8, 4, 2, 1, and 0.5 μm in equivalent aerodynamic diameter, respectively) collected during an ADS event on 28–29 April 2005. The results showed that there were large differences in the chemical compositions between particles in sample S1 collected in Beijing immediately after the peak time of the ADS and in samples S2 and S3, which were collected in Incheon approximately 5 h and 24 h later, respectively. In sample S1, mineral dust particles accounted for more than 88% in relative number abundance at stages 1–5; and organic carbon (OC) and reacted NaCl-containing particles accounted for 24% and 32%, respectively, at stage 6. On the other hand, in samples S2 and S3, in addition to approximately 60% mineral dust, many sea spray aerosol (SSA) particles reacted with airborne SO2 and NOx (accounting for 24% and 14% on average in samples S2 and S3, respectively), often mixed with mineral dust, were encountered at stages 1–5, and (C, N, O, S)-rich particles (likely a mixture of water-soluble organic carbon with (NH4)2SO4 and NH4NO3) were abundantly observed at stage 6 (accounting for 68% and 51% in samples S2 and S3, respectively). This suggests that an accumulation of sea-salt components on individual ADS particles larger than 1 μm in diameter occurred and many secondary aerosols smaller than 1 μm in diameter were formed when the ADS particles passed over the Yellow Sea. In the reacted or aged mineral dust and SSA particles, nitrate-containing and both nitrate- and sulfate-containing species vastly outnumbered the sulfate-containing species, implying that ambient NOx had a greater influence on the atmospheric particles than SO2 during this ADS episode. In addition to partially- or totally-reacted CaCO3, reacted or aged Mg-containing aluminosilicates were observed frequently in samples S2 and S3; furthermore, a student's t test showed that both their atomic concentration ratios of [Mg] / [Al] and [Mg] / [Si] were significantly elevated (P < 0.05) compared to those in samples S1 (for [Mg] / [Al], 0.34 ± 0.09 and 0.40 ± 0.03 in samples S2 and S3, respectively, vs. 0.24 ± 0.01 in sample S1; for [Mg] / [Si], 0.21 ± 0.05 and 0.22 ± 0.01 in samples S2 and S3, respectively, vs. 0.12 ± 0.02 in sample S1). The significant increase of [Mg] / [Al] and [Mg] / [Si] ratios in Mg-containing aluminosilicates indicates that a significant evolution or aging must have occurred on the ADS particles in the marine atmosphere during transport from China to Korea.

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