Sustainable harvesting of aqueous phase fatty acids by expanded graphite and isopropyl alcohol

2016 ◽  
Vol 41 (46) ◽  
pp. 21780-21786 ◽  
Author(s):  
Quoc Cuong Do ◽  
Mi-Sun Kim ◽  
Donghoon Kim ◽  
Seok-Oh Ko ◽  
Seoktae Kang
Keyword(s):  
Fatty Acids ◽  
Aqueous Phase ◽  
Isopropyl Alcohol ◽  
Expanded Graphite ◽  
Sustainable Harvesting

Characterization and mass load estimates of organic compounds in agricultural irrigation runoff

2002 ◽  
Vol 45 (9) ◽  
pp. 103-110 ◽  
Author(s):  
J.A. Pedersen ◽  
M.A. Yeager ◽  
I.H. Suffet
Keyword(s):  
Fatty Acids ◽  
Organic Compounds ◽  
Aqueous Phase ◽  
Surface Runoff ◽  
Aliphatic Alcohols ◽  
Fatty Acid Esters ◽  
Treated Wastewater ◽  
Gas Chromatography Mass Spectrometry ◽  
Agricultural Fields ◽  
Mass Load

Investigations of agricultural chemicals in surface runoff typically target nutrients or specific pesticides; however, numerous other organic compounds are regularly applied to agricultural fields in pesticide formulations, irrigation water, soil amendments and fertilizers. Many of these compounds have toxicological significance. We conducted a broad spectrum analysis of surface runoff from individual irrigated agricultural fields in coastal southern California to characterize organic compounds amenable to analysis by gas chromatography-mass spectrometry and to estimate the mass flux of selected chemicals. Aqueous phase extracts contained several pesticides, as well as personal care product ingredients and pharmaceutically active compounds apparently derived from treated wastewater used for irrigation. Several compounds potentially associated with pesticide adjuvants were also present in aqueous phase extracts. Dissolved NOM constituents in water phase extracts included n-fatty acids, aliphatic alcohols and plant terpenoids. Tentatively identified compounds sorbed to suspended particles included pesticides, a fecal sterol, aliphatic and alicyclic hydrocarbons, aliphatic alcohols, aldehydes, and C14 and C16n-fatty acids and fatty acid esters. Bicyclic and polycyclic aromatic hydrocarbons were identified in both aqueous and suspended particle phases. Constituent concentrations, including total suspended solids (TSS), varied over the course of the sampled events by up to an order of magnitude, and typically were not correlated with flow. Variation in sorbed organic compound concentrations often did not parallel those for TSS concentration. Mass load estimates were strongly influenced by the choice of sampling interval.

scholarly journals pH-Metric Determination of the Acid Value of Vegetable Oils without Titration

1998 ◽  
Vol 81 (4) ◽  
pp. 873-879 ◽  
Author(s):  
Ilya Kuselman ◽  
Yakov I Tur’yan ◽  
Oleg Y Berezin ◽  
Lina Kogan ◽  
Avinoam Shenhar
Keyword(s):  
Fatty Acids ◽  
Quality Control ◽  
Free Fatty Acids ◽  
Vegetable Oils ◽  
Isopropyl Alcohol ◽  
Acid Value ◽  
Standard Acid ◽  
Initial Ph ◽  
The Difference

Abstract The acid value (AV) of vegetable oils is determined without titration by using a new reagent consisting of triethanolamine in a solution of water and isopropyl alcohol. When the oil sample is mixed with the reagent in the pH-metric cell, free fatty acids from the sample are extracted into the reagent ( 3 - 4 min). The initial pH, called conditional pH´, is measured, a standard acid (HC1) is added, and the final pH, pH´2, is measured. AV is calculated from the difference between pH´! and pH´2. The method is applicable for quality control of vegetable oils during their production, trade, and use

Decomposition of Lecithin in Parenteral Fat Emulsions

1956 ◽  
Vol 186 (3) ◽  
pp. 397-402 ◽  
Author(s):  
G. Frederick Lambert ◽  
Jonathan P. Miller ◽  
Douglas V. Frost
Keyword(s):  
Fatty Acids ◽  
Aqueous Solutions ◽  
Aqueous Phase ◽  
Myristic Acid ◽  
Room Temperature ◽  
Clinical Use ◽  
Clear Indication ◽  
Fat Emulsions ◽  
Egg Lecithin ◽  
Hydrolysis Of

Aqueous solutions of alcohol-soluble phosphatide, synthetic lecithin and purified egg lecithin develop hemolytic and other toxic properties over a period of time at ordinary room temperature, or at an increased rate at 40°C. The toxicity of emulsions made with phosphatide as a stabilizer also increases with time. The evidence suggests that hydrolysis of synthetic lecithin proceeds first to give a hemolytic product, presumably lysolecithin. When liberation of both fatty acids from l-alpha-dimyristoyl lecithin was complete and the myristic acid was removed, no toxicity was shown by the aqueous phase, presumably glyceryl phosphorylcholine. Attempts to decrease the hydrolysis of lecithin solutions did not succeed. Although the use of lecithin phosphatide preparations as emulsifiers for intravenous fat may have limitations as to time and temperature of storage, there is no clear indication from these studies that any real hazard is involved from the standpoint of clinical use.

Association of lysophosphatidylcholine with fatty acids in aqueous phase to form bilayers

Nature ◽  
1980 ◽  
Vol 284 (5755) ◽  
pp. 486-487 ◽  
Author(s):  
M. K. Jain ◽  
 C. J. A. van Echteld ◽  
 F. Ramirez ◽  
 J. de Gier ◽  
 G. H. de Haas ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Aqueous Phase

The pattern of release of free fatty acids from milk fat under the action of intrinsic and added lipases

1970 ◽  
Vol 37 (1) ◽  
pp. 83-96 ◽  
Author(s):  
E. B. Hemingway ◽  
G. H. Smith ◽  
J. A. F. Rook
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Aqueous Phase ◽  
Milk Fat ◽  
Fatty Acid Content ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Similar Action ◽  
Early Stages

Summary(1) The rate of release of fatty acids from milk by porcine pancreatic lipase was studied as a model system for the development of lipase taint. The rate was low initially but then increased logarithmically and later declined. Addition of milk which had been subjected to the action of lipase and then boiled to inactivate the enzyme enhanced fatty acid release. An extract containing monoglycerides from lipolysed milk had a similar action whereas an extract of free fatty acids had an effect mainly in the early stages, increasing the initial rate. Addition of Ca2+, which accelerated lipolysis of fresh milk, enhanced the action of fatty acids and depressed that of monoglycerides.(2) In the early stages of lipolysis there was a preferential release of short-chain fatty acids and a high proportion of these passed into the aqueous phase. These effects were more pronounced at low temperature and at acid to neutral pH. At alkaline pH a greater proportion of the short-chain acids was present in the aqueous phase but the total release of these acids was less.(3) Fresh milks differed in their response to ‘aeration’ and storage at 4°C. In those in which taint was induced there was a considerable release of fatty acids in response to aeration, and a further release and also a redistribution between the aqueous and fat phases during storage. No relationship was apparent between the amount of fatty acids released and the initial fatty acid content.(4) The findings are discussed in relation to the development of lipase taint in commercial milks.

Formation of low molecular weight mono- and di-carboxylic acids and related compounds from photochemical oxidation of stearic and linoleic acids in aqueous-phase

2020 ◽  
Author(s):  
Chandra Mouli Pavuluri ◽  
Subba Rao Devineni ◽  
Zhanjie Xu ◽  
Kimitaka Kawamura ◽  
Pingqing Fu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Aqueous Phase ◽  
Cloud Condensation Nuclei ◽  
Oxidation Products ◽  
Photochemical Oxidation ◽  
Air Water Interface ◽  
Volatile Organic ◽  
Product Species ◽  
Related Compounds ◽  
Atmospheric Waters

<p>Secondary organic aerosols (SOA) that account for a substantial and often a dominant fraction of total OA mass are formed by photooxidation of various precursors derived from anthropogenic and biogenic sources in the atmosphere. They have serious impacts on the Earth’s climate system directly by scattering and absorbing solar radiation and indirectly by acting as cloud condensation nuclei, and adverse effects on human health. In recent times, considerable attention has been paid on laboratory studies, preferably in gas-phase, in order to understand the chemistry of SOA formation. However, the studies on SOA formation in aqueous phase are limited, which are mainly focused on high abundant volatile organic compounds (e.g., isoprene) and/or their oxidation products, but not on fatty acids (except oleic acid). To better understand the air-water interface photochemistry of fatty acids and their transformations to lower homologous monoacids and more oxygenated species such as diacids and related compounds in atmospheric waters (fog, cloud and aqueous aerosol), we conducted batch UV irradiation experiments on a saturated (stearic acid, C<sub>18</sub>H<sub>36</sub>O<sub>2</sub>) and an unsaturated (linoleic acid, C<sub>18</sub>H<sub>32</sub>O<sub>2</sub>) fatty acids for different time periods (age, 0-120 h) in aqueous-phase. All the irradiated samples were analyzed for measurements of mono- and di-acids, oxoacids and α-dicarbonyls. We found high abundances of monoacids followed by diacids, pyruvic acid and α-dicarbonyls in less aged samples, whereas C<sub>3</sub> and C<sub>4</sub> diacids were abundant in the more aged samples. Our results imply that the photochemical oxidation of fatty acids and subsequent transformations of the product species in atmospheric waters are significant and their contribution to more oxygenated SOA is increased with aging in the atmosphere.</p>

Quantification and speciation of volatile fatty acids in the aqueous phase

2017 ◽  
Vol 230 ◽  
pp. 81-86 ◽  
Author(s):  
Jechan Lee ◽  
Jieun Kim ◽  
Jeong-Ik Oh ◽  
Sang-Ryong Lee ◽  
Eilhann E. Kwon
Keyword(s):  
Fatty Acids ◽  
Aqueous Phase ◽  
Volatile Fatty Acids

Free fatty acid uptake by polyethylene: what can one learn from this?

1991 ◽  
Vol 261 (6) ◽  
pp. G896-G906
Author(s):  
A. J. Schwab ◽  
C. A. Goresky
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Aqueous Phase ◽  
Present Report ◽  
Equilibrium Concentration ◽  
Fatty Acid Uptake ◽  
Unstirred Layer ◽  
Acid Uptake ◽  
Net Flux ◽  
Rate Limiting

Previous experiments have shown that fatty-acid uptake by isolated hepatocytes is inhibited by albumin, but this inhibition was less than expected from the decrease in the equilibrium concentration of fatty acid. The possible explanation of this observation by the effects of codiffusion of protein-bound and unbound fatty acid across the unstirred layer surrounding these isolated cells has recently been challenged on the basis of experiments in which uptake by monolayers of hepatocytes was compared with that by a polyethylene sheet [F.J. Burczynski et al., Am. J. Physiol. 257 (Gastrointest. Liver Physiol. 20): G584-G593, 1989]. In the present report, we reevaluate the theoretical basis for interpretation of these experiments by solving the differential equations describing diffusion into a sheet behind a linear barrier. The diffusion coefficient for palmitate in polyethylene is estimated to be approximately 10(-9) cm2/s. We conclude that when proteins are absent from the aqueous phase, diffusion across the unstirred layer is rate limiting for removal of fatty acids by cellular monolayers, and also rate limiting for net flux across the water-polyethylene interface. In contrast, if the aqueous phase contains either 5 microM albumin or 125 microM beta-lactoglobulin, diffusion within the polyethylene sheet will become rate limiting. The net flux of fatty acids into a polyethylene sheet becomes insensitive to an increase in protein concentration if the latter rises above a certain threshold. The polyethylene data provide no additional insight into the manner in which hepatocytes take up free fatty acids.

Sign in / Sign up

Export Citation Format

Share Document