Characterization of Organic Acids with Different Atmospheric Particle Sizes

2012 ◽  
Vol 599 ◽  
pp. 14-22
Author(s):  
Xiang He ◽  
Feng Qian ◽  
Yao Li

Atmospheric particulate samples were collected during January, February, April and May 2012, separately. Twenty-one fatty acids and seven dicarboxylic acids were measured by GC-MS. The results show that average mass concentrations of fatty acids are 809.24ng/m³, 545.34ng/m³, 386.96ng/m³ and dicarboxylic acids are 215.14 ng/m³, 156.45 ng/m³, 111.43 ng/m³ in PM10, PM2.5, PM1, respectively. Fatty acids and dicarboxylic acids concentrate mainly in the PM1. C11-C24 of fatty acids exhibit a significant even carbon predominances, but dicarboxylic acids present no parity preponderance. In the fatty acids, the concentration of hexadecanoic acid is the highest with that of octadecanoic acid followed; Nonandioic acid is the highest in dicarboxylic acids. The results of source apportionments indicate that the fatty acids are mainly related with human activities. Coal burning for heating is the most important source in January and February, but its contribution decreases sharply in April and May for fatty acids; The main source of dicarboxylic acids is photochemical reactions.

INDIAN DRUGS ◽  
2012 ◽  
Vol 49 (04) ◽  
pp. 39-42
Author(s):  
M. S Kale ◽  
◽  
K. S. Laddha

Fixed oil obtained from the seeds of Momordica tuberosa (Roxb) Cogn. fruits (family: Cucurbitaceae) was analyzed using GC-MS. Five compounds, namely palmitic acid (hexadecanoic acid), oleic acid (9-octadecenoic acid), stearic acid (octadecanoic acid), ?-eleostearic acid (9, 11, 13-octadecatrienoic acid) and gama-linolenic acid (6, 9, 12-octadecatrienoic acid) were found to be major compounds in fixed oil obtained from the seeds of M. tuberosa fruits. Physical constants saponification value, unsaponifiable matter and acid value were found to be 182.4, 1.56% w/w and 11.44 respectively.


2010 ◽  
Vol 10 (11) ◽  
pp. 26677-26703 ◽  
Author(s):  
K. F. Ho ◽  
S. S. H. Ho ◽  
S. C. Lee ◽  
K. Kawamura ◽  
S. C. Zou ◽  
...  

Abstract. Ground-based PM2.5 samples collected in Pearl River Delta (PRD) region during winter and summer (from 14 December 2006 to 28 January 2007 in winter and from 4 July 2007 to 9 August 2007 in summer) were analyzed for 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C2) was the most abundant species followed by phthalic acid (Ph) in PRD region. The concentrations of total dicarboxylic acids ranged from 99 to 1340 ng m−3, with an average of 438 ± 267 ng m−3 in PRD. The concentrations of total ketocarboxylic acids ranged from 0.6 to 207 ng m−3 (43 ± 48 ng m−3 on average) while the concentrations of total α-dicarbonyls, including glyoxal and methylglyoxal, ranged from 0.2 to 89 ng m−3, with an average of 11 ± 18 ng m−3 in PRD. The total quantified water-soluble organic carbon (TQWOC) accounted for 3.4 ± 2.2% of OC and 14.3 ± 10.3% of water-soluble OC (WSOC). Hexadecanoic acid (C16:0), octadecanoic acid (C18:0) and oleic acid (C18:1) are the three most abundant fatty acids in PRD. The distributions of fatty acids are characterized by a strong even carbon number predominance with a maximum (Cmax) at hexadecanoic acid (C16:0). Ratio of C18:1 to C18:0 acts as an indicator for aerosol aging. In PRD, an average of C18:1/C18:0 ratio was 0.53 ± 0.39, suggesting an enhanced photochemical degradation of unsaturated fatty acid. Seasonal variations of the pollutant concentrations were found in the four sampling cities. Higher concentrations of TQWOC were observed in winter (544 ng m−3) than in summer (318 ng m−3). However, the abundances of TQWOC in OC mass were higher in summer (1.8–12.4%, 5.4% on average) than in winter (1.1–5.7, 2.6% on average), being consistent with enhanced secondary production of dicarboxylic acids in warmer weather. Spatial variations of water-soluble dicarboxylic acids were characterized by higher concentrations in Hong Kong and lower concentrations Guangzhou (GZ)/Zhaoqing (ZQ) during winter whereas highest concentrations were observed in GZ/ZQ during summer. These spatial and seasonal distributions are consistent with photochemical production and the subsequent accumulation under different meteorological conditions.


2022 ◽  
Author(s):  
Subasri Mani ◽  
Gomathi Veu ◽  
Kavitha Mary Jackson

Abstract The present study was aimed to explore the characterization of polyhydroxy butrate extracted from the bacterial strain under optimized conditions for the production of bioplastic. Under optimized fermentation conditions, Polyhydroxy butrate (PHB) was extracted and subjected to examine their properties via Thin Layer Chromotogram (TLC), Gas Chromotogram- Mass Spectrometer (GC-MS), Fourier Transform Infrared spectrum (FTIR). The presence of a brown spot in the TLC plate indicates the presence of hydroxylgroup which is similar to the polymer group. GC-MS analysis of extracted PHB shows peaks at the retention time of 3.8, 11.6 which is corresponding to octadecanoic acid, hexadecanoic acid, butyl -2-ethylester confirms the presence of polymeric nature in the extracted PHB. The absorption bands of FTIR at 1719–1720 cm −1 indicate the presence of C=O group of PHB. The absorption peaks at wave numbers 500-1000 cm -1 , 1055 cm -1 and 1230 cm -1 denotes (OH) group, (C–O) stretch and (C=O) ester group. From these results, it was confirmed that the extracted PHB is having the potential to replace petroleum plastic.


2011 ◽  
Vol 11 (5) ◽  
pp. 2197-2208 ◽  
Author(s):  
K. F. Ho ◽  
S. S. H. Ho ◽  
S. C. Lee ◽  
K. Kawamura ◽  
S. C. Zou ◽  
...  

Abstract. Ground-based PM2.5 samples collected at four different sites in Pearl River Delta region (PRD) during winter and summer (from 14 December 2006 to 28 January 2007 in winter and from 4 July to 9 August 2007 in summer) were analyzed for 30 water-soluble organic species, including dicarboxylic acids, ketocarboxylic acids and dicarbonyls, nine fatty acids, and benzoic acid. Molecular distributions of dicarboxylic acids demonstrated that oxalic acid (C2) was the most abundant species followed by phthalic acid (Ph) in PRD region. The concentrations of total dicarboxylic acids ranged from 99 to 1340 ng m−3, with an average of 438 ± 267 ng m−3 in PRD. The concentrations of total ketocarboxylic acids ranged from 0.6 to 207 ng m−3 (43 ± 48 ng m−3 on average) while the concentrations of total α-dicarbonyls, including glyoxal and methylglyoxal, ranged from 0.2 to 89 ng m−3, with an average of 11 ± 18 ng m−3 in PRD. The total quantified water-soluble compounds (TQWOC) (organic carbon) accounted for 3.4 ± 2.2% of OC and 14.3 ± 10.3% of water-soluble OC (WSOC). Hexadecanoic acid (C16:0), octadecanoic acid (C18:0) and oleic acid (C18:1) were the three most abundant fatty acids in PRD. The distributions of fatty acids were characterized by a strong even carbon number predominance with a maximum (Cmax) at hexadecanoic acid (C16:0). Ratio of C18:1 to C18:0 acts as an indicator for aerosol aging. In PRD, an average of C18:1/C18:0 ratio was 0.53 ± 0.39, suggesting an enhanced photochemical degradation of unsaturated fatty acid. Moreover, the concentrations of benzoic acid ranged from 84 to 306 ng m−3, (165 ± 48 ng m−3 on average), which can be emitted as primary pollutant from motor vehicles exhaust, or formed from photochemical degradation of aromatic hydrocarbons. Seasonal variations of the organic specie concentrations were found in the four sampling cities. Higher concentrations of TQWOC were observed in winter (598 ± 321 ng m−3) than in summer (372 ± 215 ng m−3). However, the abundances of TQWOC in OC mass were higher in summer (0.9–12.4%, 4.5 ± 2.7% on average) than in winter (1.1–5.7, 2.5 ± 1.2% on average), being consistent with enhanced secondary production of dicarboxylic acids in warmer weather. Spatial variations of water-soluble dicarboxylic acids were characterized by higher concentrations in Hong Kong and lower concentrations in Guangzhou (GZ)/Zhaoqing (ZQ) during winter whereas the highest concentrations were observed in GZ/ZQ during summer. These spatial and seasonal distributions are consistent with photochemical production and the subsequent accumulation under different meteorological conditions.


2011 ◽  
Vol 364 ◽  
pp. 95-99 ◽  
Author(s):  
S.C. Goh ◽  
S.Y. Chin ◽  
L.M.S. Lee ◽  
Mohd Ambar Yarmo ◽  
N.I. Nik Yusof

In this research, new chemistry is explored through a simple, efficient and cheap method to synthesize new surfactants from palm oil fatty acids. Oleic acid, which is one of the major fatty acids in palm oil, has been used as a starting material for the synthesis of surfactants. This study focuses on the synthesis and characterization of bolaform surfactants from oleic acid. For this purpose, two steps reaction will be carried out: Firstly, consisted of hydrobromination of oleic acid followed by reaction of 10-bromo-octadecanoic acid with ethane-1,2-dithiol and butane-1,2-dithiol. During the first stage of the reaction, hydrobromination of oleic acid was carried out by adding hydrobromic acid into the oleic acid. The reaction was carried out in benzene as solvent at 30°C and atmospheric pressure. This reaction gives 73% yield of 10-bromo-octadecanoic acid and it yield a black brownish liquid which have the m/z 363.2056 by ESI-MS(ToF) and –CH2-CHBr-CH2-shift (4.02 ppm) was well defined in1H-NMR. The separation of 10-bromo-octadecanoic acid was done through thin layer chromatography (TLC) with chloroform and methanol as the eluent and silica plate grade 60 F254as the stationary phase. The second stage of reaction was reacting the 10-bromo-octadecanoic acid with ethane-1,2-dithiol and butane-1,2-dithiol in THF as the solvent and 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) as the catalyst respectively. These reactions were carried out at 30°C and atmospheric pressure. Product obtained was a two layers black brownish liquid with white colour precipitate gives m/z: 659.4813 for ethane-1,2-dithiol and m/z:686.5278 for butane-1,4-dithiol respectively using ESI-MS (ToF) mass spectroscopy. Separation was done on both bolaform surfactants through thin layer chromatography (TLC) with hexane and ethyl acetate as eluent and silica plate grade 60 F254as stationary phase, and finally followed by column chromatography. These two new surfactants will be tested for their physical-chemical properties as well as apply on nanomaterial stabilizer.


2003 ◽  
Vol 69 (10) ◽  
pp. 5983-5991 ◽  
Author(s):  
David L. Craft ◽  
Krishna M. Madduri ◽  
Mark Eshoo ◽  
C. Ron Wilson

ABSTRACT Candida tropicalis ATCC 20336 excretes α,ω-dicarboxylic acids as a by-product when cultured on n-alkanes or fatty acids as the carbon source. Previously, a β-oxidation-blocked derivative of ATCC 20336 was constructed which showed a dramatic increase in the production of dicarboxylic acids. This paper describes the next steps in strain improvement, which were directed toward the isolation and characterization of genes encoding the ω-hydroxylase enzymes catalyzing the first step in the ω-oxidation pathway. Cytochrome P450 monooxygenase (CYP) and the accompanying NADPH cytochrome P450 reductase (NCP) constitute the hydroxylase complex responsible for the first and rate-limiting step of ω-oxidation of n-alkanes and fatty acids. 10 members of the alkane-inducible P450 gene family (CYP52) of C. tropicalis ATCC20336 as well as the accompanying NCP were cloned and sequenced. The 10 CYP genes represent four unique genes with their putative alleles and two unique genes for which no allelic variant was identified. Of the 10 genes, CYP52A13 and CYP52A14 showed the highest levels of mRNA induction, as determined by quantitative competitive reverse transcription-PCR during fermentation with pure oleic fatty acid (27-fold increase), pure octadecane (32-fold increase), and a mixed fatty acid feed, Emersol 267 (54-fold increase). The allelic pair CYP52A17 and CYP52A18 was also induced under all three conditions but to a lesser extent. Moderate induction of CYP52A12 was observed. These results identify the CYP52 and NCP genes as being involved in α,ω-dicarboxylic acid production by C. tropicalis and provide the foundation for biocatalyst improvement.


2018 ◽  
Vol 15 (30) ◽  
pp. 438-446
Author(s):  
V. C. B. SILVA ◽  
E. P. de SIQUEIRA ◽  
S. N. ALVES ◽  
L. A. R. S. LIMA

Oils were obtained from unripe and ripe fruits of Solanum lycocarpum. In this study, the volatile and semi-volatile compounds of oils were characterized by gas chromatography-mass spectrometry (GC-MS). Oil of unripe fruits (OUF) of S. lycocarpum exhibited principally fatty acids, esters, hydrocarbons and sterols. However, oil of ripe fruits (ORF) presented the major compounds esters and sterols. In OUF-7, the predominant compound was octadecanoic acid (73.37%), in ORF-2, octadecanoic acid octadecyl ester (59.30%) and in ORF-3, hexadecanoic acid hexadecyl ester (97.98%). Sitosterol, identified in OUF-2 and OUF-6, is predominant sterol found in various species of Solanum can have chemotaxonomy importance for this genus. This is the first time, to the best of our knowledge, that volatile and semi-volatile compounds of oils from S. lycocarpum fruits have been characterized.


Author(s):  
L. S. Lin ◽  
K. P. Gumz ◽  
A. V. Karg ◽  
C. C. Law

Carbon and temperature effects on carbide formation in the carburized zone of M50NiL are of great importance because they can be used to control surface properties of bearings. A series of homogeneous alloys (with M50NiL as base composition) containing various levels of carbon in the range of 0.15% to 1.5% (in wt.%) and heat treated at temperatures between 650°C to 1100°C were selected for characterizations. Eleven samples were chosen for carbide characterization and chemical analysis and their identifications are listed in Table 1.Five different carbides consisting of M6C, M2C, M7C3 and M23C6 were found in all eleven samples examined as shown in Table 1. M6C carbides (with least carbon) were found to be the major carbide in low carbon alloys (<0.3% C) and their amounts decreased as the carbon content increased. In sample C (0.3% C), most particles (95%) encountered were M6C carbide with a particle sizes range between 0.05 to 0.25 um. The M6C carbide are enriched in both Mo and Fe and have a fee structure with lattice parameter a=1.105 nm (Figure 1).


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2286
Author(s):  
Gwang-Woo Kim ◽  
Jae-Man Sim ◽  
Yutaka Itabashi ◽  
Min-Jeong Jung ◽  
Joon-Young Jun

Fatty acids in marine algae have attracted the attention of natural chemists because of their biological activity. The fatty acid compositions of the Solieriaceae families (Rhodophyceae, Gaigartinales) provide interesting information that unusual cyclic fatty acids have been occasionally found. A survey was conducted to profile the characteristic fatty acid composition of the red alga Solieria pacifica (Yamada) Yoshida using gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). In S. pacifica, two cyclopentyl fatty acids, 11-cyclopentylundecanoic acid (7.0%), and 13-cyclopentyltridecanoic acid (4.9%), and a cyclopropane fatty acid, cis-11,12-methylene-hexadecanoic acid (7.9%) contributed significantly to the overall fatty acid profile. In particular, this cyclopropane fatty acid has been primarily found in bacteria, rumen microorganisms or foods of animal origin, and has not previously been found in any other algae. In addition, this alga contains a significant amount of the monoenoic acid cis-11-hexadecenoic acid (9.0%). Therefore, cis-11,12-methylene-hexadecanoic acid in S. pacifica was likely produced by methylene addition to cis-11-hexadecenoic acid.


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