scholarly journals Impact of organic acids on chloride depletion of inland transported sea spray aerosols

2020 ◽  
Author(s):  
Bojiang Su ◽  
Zeming Zhuo ◽  
Yuzhen Fu ◽  
Wei Sun ◽  
Ying Chen ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Acids ◽  
Asian Summer Monsoon ◽  
Heterogeneous Reactions ◽  
Sea Spray ◽  
Biological Origin ◽  
Aerosol Mass ◽  
Chloride Depletion ◽  
Positive Correlations ◽  
The Impact

Abstract. Heterogeneous reactions on sea spray aerosols (SSA) are the main pathway to drive the circulation of chlorine, nitrogen, and sulfur in the atmosphere. The release of Cl will significantly affect the physicochemical properties of SSA. However, the impact of organic acids and mixing state on chloride depletion of SSA is still unclear. Hence, the size and chemical composition of individual SSA particles during the East Asian summer monsoon were investigated by a single particle aerosol mass spectrometer (SPAMS). According to the chemical composition, SSA particles were classified into SSA-Aged, SSA-Bio and SSA-Ca. In comparison to the aged Na-rich SSA particles (SSA-Aged), some additional organic species related to biological origin were observed in SSA-Bio, and each of two types accounts for approximately 50 % of total SSA particles. SSA-Ca may associated with organic shell of Na-rich SSA particles, which only accounts for ~ 3 %. Strongly positive correlations between Na and organic acids (including formate, acetate, propionate, pyruvate, oxalate, malonate, succinate, and glutarate) were observed for the SSA-Aged (r2 = 0.52, p 

scholarly journals Towards a better understanding of the origins, chemical composition and aging of oxygenated organic aerosols: case study of a Mediterranean industrialized environment, Marseille

2013 ◽  
Vol 13 (15) ◽  
pp. 7875-7894 ◽  
Author(s):  
I. El Haddad ◽  
B. D'Anna ◽  
B. Temime-Roussel ◽  
M. Nicolas ◽  
A. Boreave ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Aerosols ◽  
Industrial Emissions ◽  
Aerosol Mass Spectrometer ◽  
Statistical Confidence ◽  
Aerosol Mass ◽  
Novel Approach ◽  
Organic Markers ◽  
The Impact ◽  
First Time

Abstract. As part of the FORMES summer 2008 experiment, an Aerodyne compact time-of-flight aerosol mass spectrometer (cToF-AMS) was deployed at an urban background site in Marseille to investigate the sources and aging of organic aerosols (OA). France's second largest city and the largest port in the Mediterranean, Marseille, provides a locale that is influenced by significant urban industrialized emissions and an active photochemistry with very high ozone concentrations. Particle mass spectra were analyzed by positive matrix factorization (PMF2) and the results were in very good agreement with previous apportionments obtained using a chemical mass balance (CMB) approach coupled to organic markers and metals (El Haddad et al., 2011a). AMS/PMF2 was able to identify for the first time, to the best of our knowledge, the organic aerosol emitted by industrial processes. Even with significant industries in the region, industrial OA was estimated to contribute only ~ 5% of the total OA mass. Both source apportionment techniques suggest that oxygenated OA (OOA) constitutes the major fraction, contributing ~ 80% of OA mass. A novel approach combining AMS/PMF2 data with 14C measurements was applied to identify and quantify the fossil and non-fossil precursors of this fraction and to explicitly assess the related uncertainties. Results show with high statistical confidence that, despite extensive urban and industrial emissions, OOA is overwhelmingly non-fossil, formed via the oxidation of biogenic precursors, including monoterpenes. AMS/PMF2 results strongly suggest that the variability observed in the OOA chemical composition is mainly driven in our case by the aerosol photochemical age. This paper presents the impact of photochemistry on the increase of OOA oxygenation levels, formation of humic-like substances (HULIS) and the evolution of α-pinene SOA (secondary OA) components.

scholarly journals Chemical Composition of Cynara cardunculus L. var. altilis Bracts Cultivated in Central Greece: The Impact of Harvesting Time

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1976
Author(s):  
Filipa Mandim ◽  
Spyridon A. Petropoulos ◽  
Kyriakos D. Giannoulis ◽  
Celestino Santos-Buelga ◽  
Isabel C. F. R. Ferreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Organic Acids ◽  
Saturated Fatty Acids ◽  
Dry Weight ◽  
Monounsaturated Fatty Acids ◽  
Maturity Stage ◽  
Harvesting Time ◽  
Late Maturity ◽  
The Impact

The present study evaluated the effect of maturity stage on the chemical composition of cardoon bracts. Plant material was collected in Greece at eight different maturation stages (C1–C8) and the chemical composition was analyzed in regard to lipidic fraction and the content in fatty acids, tocopherols, organic acids, and free sugars. Samples of late maturity (C6–C8) revealed the lowest lipidic content, while a total of 29 fatty acids was identified in all the samples, with palmitic, stearic, oleic, and eicosatrienoic acids present in the highest levels depending on harvesting time. Immature (C1) and mature (C8) bracts were more abundant in saturated fatty acids (SFA) than bracts of medium-to-late maturity (C5, C6), where the monounsaturated fatty acids (MUFA) were the prevalent class. The α- and γ-tocopherols were the only identified isoforms of vitamin E, while the highest content was observed in sample C8 (199 µg/100 g dry weight (dw). The detected organic acids were oxalic, quinic, malic, citric, and fumaric acids, while fructose, glucose, sucrose, trehalose, and raffinose were the main detected sugars. The results of the present study allowed us to reveal the effect of maturity stage on cardoon bracts chemical composition and further valorize this byproduct by improving its bioactive compounds content.

scholarly journals Chemical Composition of Cynara Cardunculus L. var. altilis Heads: The Impact of Harvesting Time

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1088 ◽  
Author(s):  
Filipa Mandim ◽  
Spyridon A. Petropoulos ◽  
Ângela Fernandes ◽  
Celestino Santos-Buelga ◽  
Isabel C. F. R. Ferreira ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Organic Acids ◽  
Saturated Fatty Acids ◽  
Industrial Applications ◽  
Added Value ◽  
Maturation Stage ◽  
Literature Study ◽  
Harvesting Time ◽  
The Impact

Cardoon is a multi-purpose crop with several industrial applications, while the heads (capitula) are edible and commonly used in various dishes of the Mediterranean diet. Several reports in the literature study the chemical composition of the various plants parts (leaves, flower stalks, bracts, seeds) aiming to industrial applications of crop bio-waste, whereas for the heads, most of the studies are limited to the chemical composition and bioactive properties at the edible stage. In the present study, cardoon heads were collected at six different maturation stages and their chemical composition was evaluated in order to determine the effect of harvesting stage and examine the potential of alternative uses in the food and nutraceutical industries. Lipidic fraction and the content in fatty acids, tocopherols, organic acids, and free sugars were determined. Lipidic content decreases with the maturation process, while 22 fatty acids were detected in total, with palmitic, oleic, and linoleic acids being those with the highest abundance depending on harvesting time. In particular, immature heads have a higher abundance in saturated fatty acids (SFA), whereas the samples of mature heads were the richest in monounsaturated fatty acids (MUFA). The α-tocopherol was the only isoform detected being present in higher amounts in sample Car B (619 µg/100 g dw). Oxalic, quinic, malic, citric and fumaric acids were the detected organic acids, and the higher content was observed in sample Car E (15.7 g/100 g dw). The detected sugars were fructose, glucose, sucrose, trehalose and raffinose, while the highest content (7.4 g/100 g dw) was recorded in sample Car C. In conclusion, the maturation stage of cardoon heads influences their chemical composition and harvesting time could be a useful means to increase the quality and the added value of the final product by introducing this material in the food and nutraceutical industries.

scholarly journals Impact of Aerosol-Cloud Cycling on Aqueous Secondary Organic Aerosol Formation

2019 ◽  
Author(s):  
William G. Tsui ◽  
Joseph L. Woo ◽  
V. Faye McNeill
Keyword(s):  
Organic Acids ◽  
Aqueous Phase ◽  
Atmospheric Aerosols ◽  
Organic Material ◽  
Time Of Day ◽  
Aerosol Formation ◽  
Cloud Processing ◽  
Aerosol Mass ◽  
Phase Chemistry ◽  
The Impact

Chemical processing of organic material in aqueous atmospheric aerosols and cloudwater is known to form secondary organic aerosols (SOA), although the extent to which each of these processes contributes to total aerosol mass is unclear. In this study, we use GAMMA 5.0, a photochemical box model with coupled gas and aqueous-phase chemistry, to consider the impact of aqueous organic reactions in both aqueous aerosols and clouds on isoprene epoxydiol (IEPOX) SOA over a range of pH for both aqueous phases, including cycling between cloud and aerosol within a single simulation. Low-pH aqueous aerosol, in the absence of organic coatings or other morphology which may limit uptake of IEPOX, is found to be an efficient source of IEPOX SOA, consistent with previous work. Cloudwater at pH 4 or lower is also found to be a potentially significant source of IEPOX SOA. This phenomenon is primarily attributed to the relatively high uptake of IEPOX to clouds as a result of higher water content in clouds as compared to aerosol. For more acidic cloudwater, the aqueous organic material is comprised primarily of IEPOX SOA and lower-volatility organic acids. For both cloudwater and aqueous aerosol, pH is the most significant factor considered in this study in determining the mass of aqueous phase organic acids and IEPOX SOA. Other factors, such as the time of day or sequence of aerosol-to-cloud or cloud-to-aerosol transitions, contribute to less than 15% difference in the final aqSOA fractional composition. The potential significance of cloud processing as a contributor to IEPOX SOA production could account for discrepancies between predicted IEPOX SOA mass from atmospheric models and measured ambient IEPOX SOA mass, or observations of IEPOX SOA in locations where mass transfer limitations are expected in aerosol particles.

scholarly journals Enrichment of submicron sea-salt-containing particles in small cloud droplets based on single-particle mass spectrometry

2019 ◽  
Vol 19 (16) ◽  
pp. 10469-10479 ◽  
Author(s):  
Qinhao Lin ◽  
Yuxiang Yang ◽  
Yuzhen Fu ◽  
Guohua Zhang ◽  
Feng Jiang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Acids ◽  
Single Particle ◽  
Southern China ◽  
Cloud Condensation Nuclei ◽  
Sea Salt ◽  
Cloud Droplets ◽  
Organic Species ◽  
Aerosol Mass ◽  
Ccn Activity

Abstract. The effects of the chemical composition and size of sea-salt-containing particles on their cloud condensation nuclei (CCN) activity are incompletely understood. We used a ground-based counterflow virtual impactor (GCVI) coupled with a single-particle aerosol mass spectrometer (SPAMS) to characterize chemical composition of submicron (dry diameter of 0.2–1.0 µm) and supermicron (1.0–2.0 µm) sea-salt-containing cloud residues (dried cloud droplets) at Mount Nanling, southern China. Seven cut sizes (7.5–14 µm) of cloud droplets were set in the GCVI system. The highest number fraction of sea-salt-containing particles was observed at the cut size of 7.5 µm (26 %, by number), followed by 14 µm (17 %) and the other cut sizes (3 %–5 %). The submicron sea-salt-containing cloud residues contributed approximately 20 % (by number) at the cut size of 7.5 µm, which was significantly higher than the percentages at the cut sizes of 8–14 µm (below 2 %). This difference was likely involved in the change in the chemical composition. At the cut size of 7.5 µm, nitrate was internally mixed with over 90 % of the submicron sea-salt-containing cloud residues, which was higher than sulfate (20 %), ammonium (below 1 %), amines (6 %), hydrocarbon organic species (2 %), and organic acids (4 %). However, at the cut sizes of 8–14 µm, nitrate, sulfate, ammonium, amines, hydrocarbon organic species, and organic acids were internally mixed with > 90 %, > 80 %, 39 %–84 %, 71 %–86 %, 52 %–90 %, and 32 %–77 % of the submicron sea-salt-containing cloud residues. The proportion of sea-salt-containing particles in the supermicron cloud residues generally increased as a function of cut size, and their CCN activity was less influenced by chemical composition. This study provided a significant contribution towards a comprehensive understanding of sea-salt CCN activity.

scholarly journals Chemical Composition and Cytotoxicity of Kalanchoe pinnata Leaves Extracts prepared using Accelerated System Extraction (ASE)

2018 ◽  
Vol 13 (2) ◽  
pp. 1934578X1801300
Author(s):  
Kassia M. F. Pereira ◽  
Simone S. Grecco ◽  
Carlos R. Figueiredo ◽  
Jorge K. Hosomi ◽  
Mari U. Nakamura ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Acids ◽  
Folk Medicine ◽  
Extraction Methods ◽  
In Vitro Cytotoxicity ◽  
Human Leukemia ◽  
Crude Extracts ◽  
Kalanchoe Pinnata ◽  
The Impact

Kalanchoe pinnata (Crassulaceae) is a medicinal plant distributed in several areas of the World. Their leaves have been used, in folk medicine, for anxiety and sleep disorders among other proposes. Chemically, this plant is composed by organic acids, flavonoids, bufadienolides, triterpenoids and some ubiquitous compounds. In this study, the fresh leaves of K. pinnata were extracted in an accelerated solvent extraction (ASE) system using H2O (cold and hot) as well as with EtOH:H2O 1:1. The obtained crude extracts were analyzed by HPLC-UV-MS. As a result, were identified organic acids and flavonoids, these being quercetin-3- O-α-L-arabinopyranosyl-(1→2)-α-L-rhamnopyranoside, kaempferol-3- O-α-L-arabinopiranosyl-(1→2)-α-L-rhamnopyranoside, quercitrin, and trans- p-coumaryl glutaric acid the main compounds in the studied extracts. Obtained results revealed the predominance of flavonoids in extracts prepared using hot H2O (70 26 α 2.19%) or EtOH:H2O 1:1 (74.65 α 5.39%) while a reduction in the amount of these compounds was observed in the extracts prepared using cold H2O (54.41 α 2.93%). Additionally, crude extracts from leaves of K. pinnata extracted with hot H2O and EtOH:H2O 1:1 showed in vitro cytotoxicity on five tested cancer cell lines: murine melanoma (B16F10), human melanoma (A2058), human cervical carcinoma (HeLa), human leukemia (HL-60), and human glioblastoma (U87-MG), with IC50 values in the range of 10.6 α 2.5-91.3 α 7.2 μg/mL. On the other hand, the extract prepared using cold H2O displayed reduced potential. These crude extracts were also tested against human foreskin fibroblasts (non-tumorigenic cells) showing IC50 values ranging from 79.5 to 90.2 μg/mL. In conclusion, our results showed the impact that different extraction methods have on the chemical composition and pharmacological activity, which are notable for the anticancer activity associated to flavonoids.

scholarly journals Direct contribution of ammonia to <i>α</i>-pinene secondary organic aerosol formation

2020 ◽  
Vol 20 (22) ◽  
pp. 14393-14405
Author(s):  
Liqing Hao ◽  
Eetu Kari ◽  
Ari Leskinen ◽  
Douglas R. Worsnop ◽  
Annele Virtanen
Keyword(s):  
Chemical Composition ◽  
High Resolution ◽  
Organic Acids ◽  
Gas Phase ◽  
Mass Spectrometer ◽  
Mass Concentration ◽  
Organic Aerosol ◽  
Particle Phase ◽  
Resolution Time ◽  
Aerosol Mass

Abstract. Ammonia (NH3), a gaseous compound ubiquitously present in the atmosphere, is involved in the formation of secondary organic aerosol (SOA), but the exact mechanism is still not well known. This study presents the results of SOA experiments from the photooxidation of α-pinene in the presence of NH3 in the reaction chamber. SOA was formed in in nucleation experiments and in seeded experiments with ammonium sulfate particles as seeds. The chemical composition and time series of compounds in the gas and particle phase were characterized by an online high-resolution time-of-flight proton-transfer-reaction mass spectrometer (HR-ToF-PTRMS) and a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS), respectively. Our results show that the mass concentration of ammonium (NH4+) was still rising even after the mass concentration of the organic component started to decrease due to aerosol wall deposition and evaporation, implying the continuous new formation of particle-phase ammonium in the process. Stoichiometric neutralization analysis of aerosol indicates that organic acids have a central role in the formation of particle-phase ammonium. Our measurements show a good correlation between the gas-phase organic mono- and dicarboxylic acids formed in the photooxidation of α-pinene and the ammonium in the particle phase, thus highlighting the contribution of gas-phase organic acids to the ammonium formation. The work shows that the gas-phase organic acids contribute to the SOA formation by forming organic ammonium salts through acid–base reaction. The changes in aerosol mass, particle size and chemical composition resulting from the NH3–SOA interaction can potentially alter the aerosol direct and indirect forcing and therefore alter its impact on climate change.

scholarly journals Enrichment of submicron sea salt-containing particles in small cloud droplets based on single particle mass spectrometry

2019 ◽  
Author(s):  
Qinhao Lin ◽  
Yuxiang Yang ◽  
Yuzhen Fu ◽  
Guohua Zhang ◽  
Feng Jiang ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Organic Acids ◽  
Single Particle ◽  
Southern China ◽  
Cloud Condensation Nuclei ◽  
Sea Salt ◽  
Cloud Droplets ◽  
Organic Species ◽  
Aerosol Mass ◽  
Ccn Activity

Abstract. The effects of chemical composition and size of sea salt-containing particles on their cloud condensation nuclei (CCN) activity are incompletely understood. We used a ground-based counterflow virtual impactor (GCVI) coupled with a single particle aerosol mass spectrometer (SPAMS) to characterize chemical composition of submicron (dry diameter of 0.2–1.0 μm) and supermicron (dry diameter of 1.0–2.0 μm) sea salt-containing cloud residues (dried cloud droplets) at Mount Nanling, southern China. Seven cut sizes (7.5–14 μm) of cloud droplets were set in the GCVI system. Approximately 20 % (by number) of the submicron cloud residues included sea salt-containing particles at the cut size of 7.5 μm, which was significantly higher than the percentages at the cut sizes of 8–14 μm (below 2 %). This difference was likely to be involved in the change in the chemical composition. For the cut size of 7.5 μm, nitrate was internally mixed with over 90 % of the submicron sea salt-containing cloud residues, which was higher than sulfate (20 %), ammonium (below 1 %), amines (6 %), hydrocarbon organic species (2 %), and organic acids (4 %). However, nitrate, sulfate, ammonium, amines, hydrocarbon organic species, and organic acids were internally mixed with over 90 %, over 80 %, 39–84 %, 71–86 %, 52–90 %, and 32–77 %, respectively, of the submicron sea salt-containing cloud residues for the cut sizes of 8–14 μm. The proportion of sea salt-containing particles in the supermicron cloud residues generally increased as a function of cut size, and their CCN activity was less influenced by chemical composition. This study highlights the different distribution of the submicron and supermicron sea salt-containing particles in various cloud droplets, which might further influence their atmospheric residence time.

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