scholarly journals Concerted measurements of free amino acids at the Cape Verde Islands: High enrichments in submicron sea spray aerosol particles and cloud droplets

Author(s):  
Nadja Triesch ◽  
Manuela van Pinxteren ◽  
Anja Engel ◽  
Hartmut Herrmann

Abstract. This study presents measurements of free amino acids (FAA) in the marine environment to elucidate their transfer from the ocean into the atmosphere to marine aerosol particles and to clouds. FAA were investigated in seawater (underline water (ULW), sea surface microlayer (SML)), in ambient marine size-segregated aerosol particle samples at two heights (ground based at the Cape Verde Atmospheric Observatory (CVAO) and at the Mt. Verde, 744 m height) and in cloud water using concerted measurements. The ∑FAA concentration in the SML varied between 0.13–3.64 µmol L−1, in the ULW between 0.01–1.10 µmol L−1 and a strong enrichment of ∑FAA in the SML (EFSML: 1.1–298.4, average of 57.2) was observed. In the submicron (0.05–1.2 µm) aerosol particles at the CVAO, the composition of FAA was more complex and higher atmospheric concentration of ∑FAA (up to 6.3 ng m−3) compared to the supermicron (1.2–10 µm) aerosol particles (maxima of 0.5 ng m−3) were observed. The total ∑FAA concentration (PM10) was between 1.8–6.8 ng m−3 and tended to increase during the campaign. Averaged ∑FAA concentrations on the aerosol particles at the Mt. Verde were lower (submicron: 1.5 ng m−3, supermicron: 1.2 ng m−3) compared to the CVAO. A similar percentage contribution of ∑FAA to dissolved organic carbon (DOC) in the seawater (up to 7.6&tinsp;%) and to water-soluble organic carbon (WSOC) on the submicron aerosol particles (up to 5.3 %) indicated a related transfer process of FAA and DOC in the marine environment. The FAA were strongly enriched in the submicron aerosol particles (EFaer(∑FAA) 4∙102–3∙104, EFaer(WSOC) 2∙103–1∙104), possibly resulting from film droplet formation. The enrichment in supermicron aerosol particles was several orders of magnitude lower compared to supermicron size range with EFaer(∑FAA) 1∙101–2∙101, EFaer(WSOC) 3∙102–4∙102. A case study showed that several amino acids were transported from the ocean up to cloud level (e.g. aspartic acid, glutamic acid, proline) while other amino acids might not be transferred or quickly degraded (e.g. phenylalanine, tyrosine) or produced (e.g. GABA). The cloud water samples exhibited a similar composition of FAA compared to the SML but a strong variation of the atmospheric concentration of ∑FAA during the campaign (11.2–489.9 ng m−3). FAA in cloud water samples showed a strong enrichment by a factor of 4∙103 compared to the SML. The presence of high concentrations of FAA in general and of biologically produced FAA (aspartic acid) in particular together with the presence of inorganic marine tracers (sodium, methane sulfonic acid) demonstrates the influence of oceanic sources on marine clouds.

2021 ◽  
Vol 21 (1) ◽  
pp. 163-181
Author(s):  
Nadja Triesch ◽  
Manuela van Pinxteren ◽  
Anja Engel ◽  
Hartmut Herrmann

Abstract. Measurements of free amino acids (FAAs) in the marine environment to elucidate their transfer from the ocean into the atmosphere, to marine aerosol particles and to clouds, were performed at the MarParCloud (marine biological production, organic aerosol particles and marine clouds: a process chain) campaign at the Cabo Verde islands in autumn 2017. According to physical and chemical specifications such as the behavior of air masses, particulate MSA concentrations and MSA∕sulfate ratios, as well as particulate mass concentrations of dust tracers, aerosol particles predominantly of marine origin with low to medium dust influences were observed. FAAs were investigated in different compartments: they were examined in two types of seawater underlying water (ULW) and in the sea surface microlayer (SML), as well as in ambient marine size-segregated aerosol particle samples at two heights (ground height based at the Cape Verde Atmospheric Observatory, CVAO, and at 744 m height on Mt. Verde) and in cloud water using concerted measurements. The ∑FAA concentration in the SML varied between 0.13 and 3.64 µmol L−1, whereas it was between 0.01 and 1.10 µmol L−1 in the ULW; also, a strong enrichment of ∑FAA (EFSML: 1.1–298.4, average of 57.2) was found in the SML. In the submicron (0.05–1.2 µm) aerosol particles at the CVAO, the composition of FAAs was more complex, and higher atmospheric concentrations of ∑FAA (up to 6.3 ng m−3) compared to the supermicron (1.2–10 µm) aerosol particles (maximum of 0.5 ng m−3) were observed. The total ∑FAA concentration (PM10) was between 1.8 and 6.8 ng m−3 and tended to increase during the campaign. Averaged ∑FAA concentrations in the aerosol particles on Mt. Verde were lower (submicron: 1.5 ng m−3; supermicron: 1.2 ng m−3) compared to the CVAO. A similar contribution percentage of ∑FAA to dissolved organic carbon (DOC) in the seawater (up to 7.6 %) and to water-soluble organic carbon (WSOC) in the submicron aerosol particles (up to 5.3 %) indicated a related transfer process of FAAs and DOC in the marine environment. Considering solely ocean–atmosphere transfer and neglecting atmospheric processing, high FAA enrichment factors were found in both aerosol particles in the submicron range (EFaer(∑FAA): 2×103–6×103) and medium enrichment factors in the supermicron range (EFaer(∑FAA): 1×101–3×101). In addition, indications for a biogenic FAA formation were observed. Furthermore, one striking finding was the high and varying FAA cloud water concentration (11.2–489.9 ng m−3), as well as enrichments (EFCW: 4×103 and 1×104 compared to the SML and ULW, respectively), which were reported here for the first time. The abundance of inorganic marine tracers (sodium, methanesulfonic acid) in cloud water suggests an influence of oceanic sources on marine clouds. Finally, the varying composition of the FAAs in the different matrices shows that their abundance and ocean–atmosphere transfer are influenced by additional biotic and abiotic formation and degradation processes. Simple physicochemical parameters (e.g., surface activity) are not sufficient to describe the concentration and enrichments of the FAAs in the marine environment. For a precise representation in organic matter (OM) transfer models, further studies are needed to unravel their drivers and understand their composition.


1966 ◽  
Vol 101 (3) ◽  
pp. 591-597 ◽  
Author(s):  
R M O'Neal ◽  
R E Koeppe ◽  
E I Williams

1. Free glutamic acid, aspartic acid, glutamic acid from glutamine and, in some instances, the glutamic acid from glutathione and the aspartic acid from N-acetyl-aspartic acid were isolated from the brains of sheep and assayed for radioactivity after intravenous injection of [2-(14)C]glucose, [1-(14)C]acetate, [1-(14)C]butyrate or [2-(14)C]propionate. These brain components were also isolated and analysed from rats that had been given [2-(14)C]propionate. The results indicate that, as in rat brain, glucose is by far the best precursor of the free amino acids of sheep brain. 2. Degradation of the glutamate of brain yielded labelling patterns consistent with the proposal that the major route of pyruvate metabolism in brain is via acetyl-CoA, and that the short-chain fatty acids enter the brain without prior metabolism by other tissue and are metabolized in brain via the tricarboxylic acid cycle. 3. When labelled glucose was used as a precursor, glutamate always had a higher specific activity than glutamine; when labelled fatty acids were used, the reverse was true. These findings add support and complexity to the concept of the metabolic; compartmentation' of the free amino acids of brain. 4. The results from experiments with labelled propionate strongly suggest that brain metabolizes propionate via succinate and that this metabolic route may be a limited but important source of dicarboxylic acids in the brain.


1979 ◽  
Vol 6 (2) ◽  
pp. 88-92 ◽  
Author(s):  
Allan R. Hovis ◽  
Clyde T. Young ◽  
Cedric W. Kuhn

Abstract Peanut (Arachis hypogaea L.) cultivars (Starr and Florunner) and four peanut introductions (PI 261945, 261946, 261973, and 261980) were each separately inoculated with a mild strain (M2) and with the necrosis strain (N) of peanut mottle virus. The effects of these viral strains on the chemical composition of peanut seed were evaluated. The chemical characteristics varied with the type of viral infection. The greatest effect was on fatty acids and the least on the total amino acids. In general, peanuts infected with the necrosis strain showed: (1) a decrease in the percentages of stearic and oleic acids, while linoleic, arachidic, behenic, and lignoceric acids increased, (2) increases in the levels of the free amino acids glycine, alanine, isoleucine, histidine, lysine, and arginine, and (3) the total amino acids exhibited a slight decrease in aspartic acid and a slight increase in methionine. Peanuts infected with the mild strain generallly showed: (1) a slight increase in linoleic acid, (2) little effect on the free amino acids, and (3) a small increase in tyrosine and a slight decrease in serine and aspartic acid for the total amino acids. No treatment effect was noted on protein content.


1975 ◽  
Vol 21 (3) ◽  
pp. 414-417 ◽  
Author(s):  
Yasuyuki Doi ◽  
Akikatsu Kataura

Abstract Free amino acids in the tonsils of 20 individuals were measured column chromatographically. Those always found in readily detectable amounts included O-phosphoserine, taurine, O-phosphoethanolamine, aspartic acid, hydroxyproline, threonine, serine, glutamic acid, proline, glycine, alanine, α-amino-n-butyric acid, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, ornithine, γ-amino-butyric acid, lysine, histidine, and arginine. Results were compared for three clinical pathological groups and for four age groups. Some abnormal values may result from the pathological conditions.


2021 ◽  
Author(s):  
Pascal Renard ◽  
Maxence Brissy ◽  
Florent Rossi ◽  
Martin Leremboure ◽  
Saly Jaber ◽  
...  

2018 ◽  
Vol 16 (1) ◽  
pp. 833-841 ◽  
Author(s):  
Magdalena Dziągwa-Becker ◽  
Ryszard Weber ◽  
Olga Zajączkowska ◽  
Wiesław Oleszek

AbstractThe purpose of this study was to establish the free amino acids profile of Viola tricolor collected from different habitats in Poland. Viola tricolor (heartsease) is a very popular plant found worldwide, classified both as weed and medicinal plant. Based on a validated method, the following nineteen free amino acids were analyzed using liquid chromatography-electrospray ionization coupled to a triple quadrupole mass spectrometer (LC-ESI-MS/MS):alanine, glycine, leucine, valine, isoleucine, proline, phenylalanine, tryptophan, tyrosine, serine, threonine, methionine, asparagine, glutamine, lysine, arginine, histidine, aspartic acid, glutamic acid. The total free amino acids (TAA) ranged from 9938.0 to 11393.8 mg/kg of fresh weight. The variability of the investigated amino acids with respect to different habitat conditions was statistically assessed using the method of discriminant and cluster analysis. Alanine, valine, glutamine and aspartic acid were the most abundant free amino acids present in both localizations. The ratio of total essential amino acids (EAA) to TAA was 0.27 and 0.11 in Zagródki and Wrocław, respectively. Discriminant analysis has demonstrated that the investigated habitats significantly differentiated the free amino acids content of Viola tricolor. Only methionine showed a similar concentration in both Viola tricolor populations.


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