The potential contribution of organic salts to new particle growth

Abstract. Field and lab measurements suggest that low-molecular weight (MW) organic acids and bases exist in accumulation and nucleation mode particles, despite their relatively high pure-liquid vapor pressures. The mechanism(s) by which such compounds contribute to the mass growth of existing aerosol particles and newly formed particles has not been thoroughly explored. One mechanism by which low-MW compounds may contribute to new particle growth is through the formation of organic salts. In this paper we use thermodynamic modeling to explore the potential for organic salt formation by atmospherically relevant organic acids and bases for two system types: one in which the relative contribution of ammonia vs. amines in forming organic salts was evaluated, the other in which the decrease in volatility of organic acids and bases due to organic salt formation was assessed. The modeling approach employed relied heavily on group contribution and other estimation methods for necessary physical and chemical parameters. The results of this work suggest that amines may be an important contributor to organic salt formation, and that experimental data are greatly needed to improve our understanding of organic salt formation in atmospherically relevant systems and to accurately predict the potential contribution of such salts to new particle growth.

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The potential contribution of organic salts to new particle growth

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-8-20723-2008 ◽

2008 ◽

Vol 8 (6) ◽

pp. 20723-20748 ◽

Cited By ~ 4

Author(s):

K. C. Barsanti ◽

P. H. McMurry ◽

J. N. Smith

Keyword(s):

Organic Acids ◽

Particle Growth ◽

Estimation Methods ◽

Organic Salt ◽

Pure Liquid ◽

Potential Contribution ◽

Salt Formation ◽

Organic Salts ◽

Acids And Bases ◽

Atmospherically Relevant

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Analysis of multiple new-particle growth pathways observed at the US DOE Southern Great Plains field site

10.5194/acp-2016-157 ◽

2016 ◽

Author(s):

Anna L. Hodshire ◽

Michael J. Lawler ◽

Jun Zhao ◽

John Ortega ◽

Coty Jen ◽

...

Keyword(s):

Sulfuric Acid ◽

Great Plains ◽

Particle Growth ◽

Particle Formation ◽

Organic Salt ◽

Particle Phase ◽

Salt Formation ◽

New Particle Formation ◽

Acid Base ◽

Southern Great Plains

Abstract. New-particle formation (NPF) is a significant source of aerosol particles to the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low-volatility species, from diameters ~ 1 nm to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric acid vapor, condensation of organic vapors, uptake of organic acids through acid-base chemistry in the particle phase, and accretion of organic molecules in the particle phase to create a lower-volatility compound that then contributes to the aerosol mass. The relative importance of each pathway is uncertain and is the focus of this work. The 2013 New Particle Formation Study (NPFS) measurement campaign took place at the DOE Southern Great Plains (SGP) facility in Lamont, Oklahoma, during spring 2013. Measured gas-and particle-phase compositions during these new-particle growth events suggest three distinct growth pathways: (1) growth by organics alone; (2) growth by sulfuric-acid/ammonia; and (3) growth by sulfuric-acid/amines/organics. To supplement the measurements, we used the particle-growth model MABNAG (Model for Acid-Base chemistry in NAnoparticle Growth) to gain further insight into the growth processes on these three days at SGP. MABNAG simulates growth from (1) sulfuric-acid condensation (and subsequent salt formation with ammonia or amines); (2) near-irreversible condensation from non-reactive extremely-low-volatility organic compounds (ELVOCs); and (3) organic-acid condensation and subsequent salt formation with ammonia or amines. MABNAG is able to corroborate the observed differing growth pathways, while also predicting that ELVOCs contribute more to growth than organic salt formation. However, most MABNAG model simulations tend to underpredict the observed growth rates; this underprediction may come from neglecting the contributions to growth from semi-to-low-volatility species or accretion reactions. Our results suggest that in addition to sulfuric acid, ELVOCs are also very important for growth in this rural setting. We discuss the limitations of our study that arise from not accounting for semi- and low-volatility organics, as well as nitrogen-containing species beyond ammonia and amines in the model. Quantitatively understanding the overall budget, evolution, and thermodynamic properties of lower-volatility organics in the atmosphere will be essential for improving global aerosol models.

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Effects and Mechanism of Organic Acids on Aluminum Availability of Dark Brown Forest Soil

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.709 ◽

2011 ◽

Vol 393-395 ◽

pp. 709-712 ◽

Cited By ~ 1

Author(s):

Fu Xing Cui ◽

Jin Feng Song ◽

Ya Fen Guo ◽

Jin Zhong Xu

Keyword(s):

Citric Acid ◽

Oxalic Acid ◽

Organic Acids ◽

Organic Acid ◽

Forest Soil ◽

Dissociation Constants ◽

Organic Salt ◽

Brown Forest Soil ◽

Organic Salts ◽

Complexation Reactions

The effects and mechanism of different concentration organic acids and organic salts solution on Al availability of dark brown forest soil were studied. It was resulted that, oxalic acid/oxalate and citric acid/citrate substantially stimulated soil Al release of dark brown forest soil. The effect of organic acids/salts on Al release would be strengthen with increasing of their concentrations.The contents of Al released from A1 horizon was higher than that from B horizon. Organic salt solutions had much higher effects than organic acid the same in concentration, i.e. citrate>citric acid, oxalate>oxalic acid. Therefore, the mechanism of organic acid/salts triggering release of soil Al was assumed to be dominated by complexation reactions of organic anions. Citric acid/ citrate had much higher effect than oxalic acid/ oxalate at same concentration to A1 and B horizons, i.e. citrate> oxalate, citric acid>oxalic acid, which was primarily related with the greater complexing capacities and dissociation constants of citric acid.

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Multiple new-particle growth pathways observed at the US DOE Southern Great Plains field site

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-9321-2016 ◽

2016 ◽

Vol 16 (14) ◽

pp. 9321-9348 ◽

Cited By ~ 15

Author(s):

Anna L. Hodshire ◽

Michael J. Lawler ◽

Jun Zhao ◽

John Ortega ◽

Coty Jen ◽

...

Keyword(s):

Sulfuric Acid ◽

Great Plains ◽

Particle Growth ◽

Particle Formation ◽

Organic Salt ◽

Particle Phase ◽

Salt Formation ◽

New Particle Formation ◽

Acid Base ◽

Southern Great Plains

Abstract. New-particle formation (NPF) is a significant source of aerosol particles into the atmosphere. However, these particles are initially too small to have climatic importance and must grow, primarily through net uptake of low-volatility species, from diameters ∼  1 to 30–100 nm in order to potentially impact climate. There are currently uncertainties in the physical and chemical processes associated with the growth of these freshly formed particles that lead to uncertainties in aerosol-climate modeling. Four main pathways for new-particle growth have been identified: condensation of sulfuric-acid vapor (and associated bases when available), condensation of organic vapors, uptake of organic acids through acid–base chemistry in the particle phase, and accretion of organic molecules in the particle phase to create a lower-volatility compound that then contributes to the aerosol mass. The relative importance of each pathway is uncertain and is the focus of this work. The 2013 New Particle Formation Study (NPFS) measurement campaign took place at the DOE Southern Great Plains (SGP) facility in Lamont, Oklahoma, during spring 2013. Measured gas- and particle-phase compositions during these new-particle growth events suggest three distinct growth pathways: (1) growth by primarily organics, (2) growth by primarily sulfuric acid and ammonia, and (3) growth by primarily sulfuric acid and associated bases and organics. To supplement the measurements, we used the particle growth model MABNAG (Model for Acid–Base chemistry in NAnoparticle Growth) to gain further insight into the growth processes on these 3 days at SGP. MABNAG simulates growth from (1) sulfuric-acid condensation (and subsequent salt formation with ammonia or amines), (2) near-irreversible condensation from nonreactive extremely low-volatility organic compounds (ELVOCs), and (3) organic-acid condensation and subsequent salt formation with ammonia or amines. MABNAG is able to corroborate the observed differing growth pathways, while also predicting that ELVOCs contribute more to growth than organic salt formation. However, most MABNAG model simulations tend to underpredict the observed growth rates between 10 and 20 nm in diameter; this underprediction may come from neglecting the contributions to growth from semi-to-low-volatility species or accretion reactions. Our results suggest that in addition to sulfuric acid, ELVOCs are also very important for growth in this rural setting. We discuss the limitations of our study that arise from not accounting for semi- and low-volatility organics, as well as nitrogen-containing species beyond ammonia and amines in the model. Quantitatively understanding the overall budget, evolution, and thermodynamic properties of lower-volatility organics in the atmosphere will be essential for improving global aerosol models.

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The Fermentation of Salts of Organic Acids as an aid to the differentiation of Bacterial Types

Journal of Hygiene ◽

10.1017/s0022172400008457 ◽

1924 ◽

Vol 23 (1) ◽

pp. 1-22 ◽

Cited By ~ 29

Author(s):

H. C. Brown ◽

J. T. Duncan ◽

T. A. Henry

Keyword(s):

Citric Acid ◽

Organic Acids ◽

Succinic Acid ◽

Fumaric Acid ◽

Direct Reduction ◽

Organic Salt ◽

Simple Explanation ◽

Organic Salts ◽

Tartaric Acids ◽

Pathogenic Vibrios

(1) Reaction changes and production of gas in organic salt media are not sufficiently constant to form a reliable diagnostic criterion for the differentiation of bacterial types.(2) The enhancement or inhibition of bacterial growth in such media in the majority of cases bears a direct relationship to the utilisation of the salt by the organism. This furnishes a useful differential test for certain organisms when citrates are used, but cannot be applied in the cases of all salts.(3) The bacterial decomposition of the salts of those organic acids which form insoluble lead salts can be clearly demonstrated by the addition of suitable quantities of a solution of lead acetate to the culture.(4) By the use of six organic salts, seven different groupings of the common Salmonella types can be obtained, whereas the sugar reactions have, up to the present, yielded only four different groupings.(5) Regarding other groups of bacteria, the organic salts form an easy means of distinguishing between pathogenic and certain non-pathogenic vibrios, and between certain of the members of thecoli-aërogenesgroup, and also betweenB. diphtheriaeand Hofmann's bacillus, as well as betweenB. malleiandB. whitmori.(6) The six organic salts employed in this test are relatively inexpensive, will stand sterilising by autoclave, and can be obtained with certainty in a state of purity much more readily than the rarer “sugars.”(7) The nature of the decomposition products of citric acid has been fully examined in the case ofBacillus suipestifer; it has been shown that the products are acetic acid, carbon dioxide and succinic acid, and a simple explanation of the mechanism of this reaction is put forward. In the case of fumaric acid a preliminary examination shows that the acid is converted into succinic acid probably by direct reduction. Maleic acid appears to behave in an analogous manner to fumaric acid. Further work on these acids is in progress.(8) A large number of organic acid salts have been tried, but only the six suggested have given useful results. It appears that simple aliphatic monobasic and dibasic acids, with the exception of formic acid, are not decomposed readily by the bacteria investigated, and this is also true of monohydroxycarboxylic acids. Readiness of decomposition is first shown by the dihydroxydicarboxylic acids (tartaric acids), and appears to be at its best in the hydroxytricarboxylic acid (citric acid).(9) While organic salt fermentation tests have been found particularly useful in the cases of the bacterial groups dealt with in this paper, they cannot be substituted for the “sugar reactions” in general use.

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