Journal articles: 'Fatty acids – Separation'

1

Boudreau, Tracy M., and Gordon A. Hill. "Improved ethanol–water separation using fatty acids." Process Biochemistry 41, no. 4 (April 2006): 980–83. http://dx.doi.org/10.1016/j.procbio.2005.11.006.

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Krishna Kumar, N. S., and D. N. Bhowmick. "Separation of fatty acids/triacylglycerol by membranes." Journal of the American Oil Chemists' Society 73, no. 3 (March 1996): 399–401. http://dx.doi.org/10.1007/bf02523439.

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Tiuca, Ioana, Katalin Nagy, and Radu Oprean. "Recent developments in fatty acids profile determination in biological samples - a review." Revista Romana de Medicina de Laborator 23, no. 4 (December 1, 2015): 371–84. http://dx.doi.org/10.1515/rrlm-2015-0035.

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Abstract The present paper is a literature review of the recent years dealing with the most important separation techniques of fatty acids in biological samples. Our aim was to make a synthesis of the analytical methods used, to note the most used ones, but also to mention other methods that are less utilized, which can have important advantages (such as less time consuming, greener reagents, etc.). Gas-chromatographic separation methods were described and compared to liquid chromatographic separations of fatty acids in different types of biological samples. In the same time, the importance of determining fatty acids profiles in biological samples was revealed, pointing out the possible implications in diagnostics of different types of disorders or remarking different profiles compared to healthy states.

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4

Gutnikov, George, Wolfgang Beck, and Heinz Engelhardt. "Separation of homologous fatty acids by capillary electrophoresis." Journal of Microcolumn Separations 6, no. 6 (November 1994): 565–70. http://dx.doi.org/10.1002/mcs.1220060606.

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Nadirov, K. S., N. Sh Otarbaev, R. K. Nadirov, V. M. Kapustin, A. S. Sadyrbaeva, and G. Zh Bimbetova. "SEPARATION OF FREE FATTY ACIDS FROM COTTON TAR." NEWS of National Academy of Sciences of the Republic of Kazakhstan 4, no. 436 (August 15, 2019): 70–78. http://dx.doi.org/10.32014/2019.2518-170x.99.

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Bousquet, Olivier, and François Le Goffic. "Counter-current chromatographic separation of polyunsaturated fatty acids." Journal of Chromatography A 704, no. 1 (June 1995): 211–16. http://dx.doi.org/10.1016/0021-9673(94)01233-5.

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Gupta, Abhinaba, and Ned B. Bowden. "Separation of cis-Fatty Acids from Saturated and trans-Fatty Acids by Nanoporous Polydicyclopentadiene Membranes." ACS Applied Materials & Interfaces 5, no. 3 (January 15, 2013): 924–33. http://dx.doi.org/10.1021/am3025867.

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Mohd Fadzel, Fatimatuzzahraa, Jumat Salimon, and Darfizzi Derawi. "Low-Energy Separation Technique on Purification of Unsaturated Fatty Acids of Palm Stearin using Methanol Crystallization Method." Sains Malaysiana 50, no. 1 (January 31, 2021): 151–60. http://dx.doi.org/10.17576/jsm-2021-5001-15.

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This paper discussed the development of a low-energy and cost-effective separation technique of saturated fatty acids (S FAs) from Malaysian Palm Stearin to purify the unsaturation level of its fatty acids. Unsaturated fatty acids (U FAs) pose great benefits in nutritional value and also can be utilized as a raw material in various food or non-food applications. A methanol crystallization separation method was introduced by manipulating the storage temperature as well as the mixture ratio of palm stearin fatty acids (PSFAs) and methanol as a solvent. The separated compounds were characterized using Fourier-transform infrared (FTIR) spectroscopy, proton (1H-NMR), and carbon (13C-NMR) spectroscopy analysis techniques. The fatty acids composition for both U FAs and S FAs were determined through gas chromatography (GC)analysis technique. The highest separation yield was about 98% (wt.), using a mixture of PSFA:methanol; 1:9 (w/v) at the temperature of -20 °C. This method was successfully separated and purified the U FAs by increasing the unsaturation level of fatty acids about 172% as the final iodine value was about 98 compared to the initial value was at 36. The low-energy methanol crystallization separation method is a cheaper method compared to the conventional high-energy fractional distillation process and positively to be up scaled at industrial level.

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Mező, Emerencia, Anita Bufa, Csilla Páger, Viktória Poór, Tamás Marosvölgyi, Ferenc Kilár, and Lilla Makszin. "The Role of Ionic Liquid Interaction in the Separation of Fatty Acid Methyl Esters—Polyunsaturated Geometric Isomers in GC–MS." Separations 8, no. 4 (March 26, 2021): 38. http://dx.doi.org/10.3390/separations8040038.

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Knowledge of the type and level of saturated and unsaturated fatty acids in food and clinical matrices is of practical importance, but the wide variety of fatty acids makes analyses very complex. The discrimination of the geometric isomers of fatty acid needs proper and effective separation conditions. The efficiency of three different stationary phases was evaluated by GC–MS methods in the separation of fatty acids in their methyl ester forms. Significant differences were observed in the efficiencies of polysiloxane-based (non-polar HP-5MS and medium/high polarity DB-225MS) and ionic liquid-based (SLB-IL111) columns. Baseline separation of the geometric isomers of linoleic acid methyl ester was obtained by the extremely polar SLB-IL111 column, showing a preference over the other two columns. The optimization of the experimental conditions (response linearity, limit of detection, limit of quantification, system suitability, intraday and interday repeatability and accuracy) showed the separation power of the ionic liquid interaction in the analyses by using short (25–30 m long) columns. By deducting the general principles of the interaction, predictions can be made for the separation of other isomers. The results facilitate the precise identification of various types of fatty acids in real samples for nutritional information.

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DOGARIS, IOANNIS, MIKAEL LINDSTROM, and GUNNAR HENRIKSSON. "Critical parameters for tall oil separation I: The importance of the ratio of fatty acids to rosin acids." TAPPI Journal 18, no. 9 (October 1, 2019): 547–55. http://dx.doi.org/10.32964/tj18.9.547.

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Tall oil is a valuable byproduct in chemical pulping of wood, and its fractions have a large spectrum of applications as chemical precursors, detergents, and fuel. High recovery of tall oil is important for the economic and environmental profile of chemical pulp mills. The purpose of this study was to investigate critical parameters of tall oil separation from black liquor. To investigate this in a controlled way, we developed a model test system using a “synthetic” black liquor (active cooking chemicals OH- and HS- ions), a complete process for soap skimming, and determination of recovered tall oil based on solvent extraction and colorimetric analysis, with good reproducibility. We used the developed system to study the effect of the ratio of fatty acids to rosin acids on tall oil separation. When high amounts of rosin acids were present, tall oil recovery was low, while high content of fatty acids above 60% significantly promoted tall oil separation. Therefore, manipulating the content of fatty acids in black liquor before the soap skimming step can significantly affect the tall oil solubility, and hence its separation. The findings open up chemical ways to improve the tall oil yield.

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Palyzová, Andrea, and Tomáš Řezanka. "Enantiomeric separation of triacylglycerols containing fatty acids with a ring (cyclofatty acids)." Journal of Chromatography A 1622 (July 2020): 461103. http://dx.doi.org/10.1016/j.chroma.2020.461103.

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Jänisch, T., S. Reinhardt, U. Pohsner, S. Böringer, R. Bolduan, J. Steinbrenner, and H. Oechsner. "Separation of volatile fatty acids from biogas plant hydrolysates." Separation and Purification Technology 223 (September 2019): 264–73. http://dx.doi.org/10.1016/j.seppur.2019.04.066.

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13

Tsuzuki, Wakako. "Inconsistencies in a Highly Polar Capillary Gas Chromatography Column and Necessity of Column Performance Checks for trans Fatty Acid Measurement." Journal of AOAC INTERNATIONAL 95, no. 6 (November 1, 2012): 1740–43. http://dx.doi.org/10.5740/jaoacint.11-352.

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Abstract GC with a capillary column (60–100 m length) is widely used to measure trans fatty acids in dietary fats and biological tissues. Recently, we have occasionally observed that isothermal operation of an SP-2560 column at 180°C results in incomplete separation of gondoic acid (11c-20:1) and one of the geometric isomers of α-linolenic acid (9t,12c,15c-18:3), although it has been known to produce their baseline separation in American Oil Chemists' Society Official Method Ce 1h-05, as well as in previous studies. Thus, trans isomer (9t,12c,15c-18:3) is one of the main components of trans fatty acids in refined edible oils, and the baseline separation of this peak from that of 11c-20:1 is indispensable. We demonstrate in this study that an isothermal operating temperature of 175°C for an SP-2560 column results in satisfactory resolution of these two fatty acids. Because of the inconsistency in the separation provided by SP-2560 columns, careful monitoring of the relative elution order of different fatty acid methyl esters using standards is necessary for the exact evaluation of trans fatty acid contents in oils and fats.

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Gilmer, Chad M., Christian Zvokel, Alexandra Vick, and Ned B. Bowden. "Separation of saturated fatty acids and fatty acid methyl esters with epoxy nanofiltration membranes." RSC Advances 7, no. 88 (2017): 55626–32. http://dx.doi.org/10.1039/c7ra11223h.

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15

Weisiger, R. A., and S. D. Zucker. "Transfer of fatty acids between intracellular membranes: roles of soluble binding proteins, distance, and time." American Journal of Physiology-Gastrointestinal and Liver Physiology 282, no. 1 (January 1, 2002): G105—G115. http://dx.doi.org/10.1152/ajpgi.00238.2001.

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Soluble fatty acid binding proteins (FABPs) are thought to facilitate exchange of fatty acids between intracellular membranes. Although many FABP variants have been described, they fall into two general classes. “Membrane-active” FABPs exchange fatty acids with membranes during transient collisions with the membrane surface, whereas “membrane-inactive” FABPs do not. We used modeling of fatty acid transport between two planar membranes to examine the hypothesis that these two classes catalyze different steps in intracellular fatty acid transport. In the absence of FABP, the steady-state flux of fatty acid from the donor to the acceptor membrane depends on membrane separation distance (d) approaching a maximum value ( J max) as d approaches zero. J max is one-half the rate of dissociation of fatty acid from the donor membrane, indicating that newly dissociated fatty acid has a 50% chance of successfully reaching the acceptor membrane before rebinding to the donor membrane. For larger membrane separations, successful transfer becomes less likely as diffusional concentration gradients develop. The mean diffusional excursion of the fatty acid into the water phase (dm) defines this transition. For d≪dm, dissociation from the membrane is rate limiting, whereas for d≫dm, aqueous diffusion is rate limiting. All forms of FABP increase dmby reducing the rate of rebinding to the donor membrane, thus maintaining J max over larger membrane separations. Membrane-active FABPs further increase J max by catalyzing the rate of dissociation of fatty acids from the donor membrane, although frequent membrane interactions would be expected to reduce their diffusional mobility through a membrane-rich cytoplasm. Individual FABPs may have evolved to match the membrane separations and densities found in specific cell lines.

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Gaiday, N. V., A. B. Lmbs, D. V. Kuklev, and N. A. Latyshev. "Separation of natural polyunsaturated fatty acids by means of lodolactonization." Journal of the American Oil Chemists Society 68, no. 4 (April 1991): 230–33. http://dx.doi.org/10.1007/bf02657614.

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17

Maeda, Kouji, Yoshihisa Nomura, Keisuke Fukui, and Shouji Hirota. "Separation of fatty acids by crystallization using two liquid phases." Korean Journal of Chemical Engineering 14, no. 3 (May 1997): 175–78. http://dx.doi.org/10.1007/bf02706091.

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18

Řezanka, Tomáš, Irena Kolouchová, Linda Nedbalová, and Karel Sigler. "Enantiomeric separation of triacylglycerols containing very long chain fatty acids." Journal of Chromatography A 1557 (July 2018): 9–19. http://dx.doi.org/10.1016/j.chroma.2018.04.064.

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19

Yong, Qiwen, Guoming Yuan, and Haijun Li. "Extraction and separation of unsaturated fatty acids from sunflower oil." IOP Conference Series: Earth and Environmental Science 680, no. 1 (March 1, 2021): 012063. http://dx.doi.org/10.1088/1755-1315/680/1/012063.

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20

Dołowy, Małgorzata, and Alina Pyka. "Chromatographic Methods in the Separation of Long-Chain Mono- and Polyunsaturated Fatty Acids." Journal of Chemistry 2015 (2015): 1–20. http://dx.doi.org/10.1155/2015/120830.

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This review presents various chromatographic systems, TLC, HPLC, GC, and also SFC, developed for identification and accurate quantification of long-chain mono- and polyunsaturated fatty acids from different samples with emphasis on selected literature which was published during last decade. Almost all the aspects such as preseparation step of fatty acids (cisandtrans), stationary phase, solvent system, and detection mode are discussed.

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21

Tappi, Silvia, Ana Cristina De Aguiar Saldanha Pinheiro, Dario Mercatante, Gianfranco Picone, Francesca Soglia, Maria Teresa Rodriguez-Estrada, Massimiliano Petracci, Francesco Capozzi, and Pietro Rocculi. "Quality Changes during Frozen Storage of Mechanical-Separated Flesh Obtained from an Underutilized Crustacean." Foods 9, no. 10 (October 17, 2020): 1485. http://dx.doi.org/10.3390/foods9101485.

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Despite their high nutritional value, high quantities of fish caught in the Adriatic Sea are underused or discarded for their insignificant economic value. Mechanical separation of flesh represents an opportunity for developing innovative semi-finished products, even if it can promote an increased quality degradation rate. The aim of this study was to evaluate physico-chemical modifications of mechanically separated mantis shrimp flesh during deep-freezing storage. Flesh samples obtained using a belt-drum separator, frozen and vacuum-packed, were stored at 3 temperatures (industrial: −26 °C; domestic: −18 °C and abuse: −10 °C) for 12 months. During storage, qualitative (color, water content, pH, fatty acids (FA) and lipid oxidation) were evaluated. Fish freshness parameters (e.g., trimethylamine (TMA), dimethylamine (DMA) and amino acids) were assessed using nuclear magnetic resonance (1H-NMR). The mechanical separation process accelerated the initial oxidation phenomena, promoting color alterations, compared to manual separation. The main degradation phenomena during storage were significantly affected by temperature and were related to changes in luminosity, oxidation of n-3 polyunsaturated fatty acids (PUFA), increased lipolysis with release of free FA, production of TMA and DMA by residual enzymatic activity, and changes in amino acids due to proteolysis. The inter-disciplinary approach permitted important findings to be made, in terms of the extent of different degradative phenomena, bound to processing and storage conditions of mechanically separated mantis flesh.

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Delmonte, Pierluigi, Ali-Reza Fardin Kia, Qing Hu, and Jeanne I. Rader. "Review of Methods for Preparation and Gas Chromatographic Separation of trans and cis Reference Fatty Acids." Journal of AOAC INTERNATIONAL 92, no. 5 (September 1, 2009): 1310–26. http://dx.doi.org/10.1093/jaoac/92.5.1310.

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Abstract In recent years, several countries have implemented new regulations regarding the limitation or labeling of the trans fatty acid (TFA) content of foods and dietary supplements. GC methods for fatty acid (FA) analysis have been updated by improving the separation of TFAs from other FAs, especially trans- and cis-18:1, and by focusing more attention on the FAs contained in fats and oils in lower amounts. FA analysis is affected by the limited availability of reference materials. Identifications are frequently made simply by comparison with separations reported in the literature. This report describes the preparation of mixtures containing fatty acid methyl esters (FAMEs) that are not available as reference materials. These mixtures can be used for FAME identifications. The prepared mixtures are analyzed under the experimental conditions of the American Oil Chemists' Society (AOCS) Official Method Ce 1h-05 and AOCS Recommended Practice Ce 1j-07.

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Burdge, Graham C., Paul Wright, Amanda E. Jones, and Stephen A. Wootton. "A method for separation of phosphatidylcholine, triacylglycerol, non-esterified fatty acids and cholesterol esters from plasma by solid-phase extraction." British Journal of Nutrition 84, no. 5 (November 2000): 781–87. http://dx.doi.org/10.1017/s0007114500002154.

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Efficient isolation of individual lipid classes is a critical step in the analysis of plasma and lipoprotein fatty acid compositions. Whilst good separations of total lipid extracts are possible by TLC, this method is time consuming and a major rate-limiting step when processing large numbers of specimens. A method for rapid separation of phosphatidylcholine (PC), non-esterified fatty acids (NEFA), cholesterol ester (CE) and triacylglycerol (TAG) from total plasma lipid extracts by solid-phase extraction (SPE) using aminopropyl silica columns has been developed and validated. Following initial separation of polar and neutral lipids, individual classes were isolated by application of solvents with increasing polarity. Recoveries for combined plasma extraction with chloroform–methanol and SPE were (%): PC 74·2 (SD 7·5), NEFA 73·6 (sd 8·3), CE 84·9 (sd 4·9), and TAG 86·8 (sd 4·9), which were significantly greater for TAG and NEFA than by TLC (P<0·001). Both GC–flame ionisation detector and GC-MS analysis of fatty acid methyl esters demonstrated that there was no cross-contamination between lipid classes. Measurements of repeatability of fatty acid composition for TAG, PC, CE and NEFA fractions showed similar CV for each fatty acid. The magnitude of the CV appeared to be related inversely to the fractional fatty acid concentration, and was greatest at concentrations of less than 1 g/100 g total fatty acids. There was no evidence of selective elution of individual fatty acid or CE species. In conclusion, this method represents an efficient, rapid alternative to TLC for isolation of these lipid classes from plasma.

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Islam, Md Shariful, Lew P. Christopher, and Md Nur Alam. "Separation and Purification of ω-6 Linoleic Acid from Crude Tall Oil." Separations 7, no. 1 (February 2, 2020): 9. http://dx.doi.org/10.3390/separations7010009.

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Crude tall oil (CTO) is the third largest by-product at kraft pulp and paper mills. Due the large presence of value-added fatty and resin acids, CTO has a huge valorization potential as a biobased, readily available, non-food, and low-cost biorefinery feedstock. The objective of this work was to present a method for the isolation of high-value linoleic acid (LA), an omega (ω)-6 essential fatty acid, from CTO using a combination of pretreatment, fractionation, and purification techniques. Following the distillation of CTO to separate the tall oil fatty acids (TOFAs) from CTO, LA was isolated and purified from TOFAs by urea complexation (UC) and low-temperature crystallization (LTC) in the temperature range between −7 and −15 °C. The crystallization yield of LA from CTO in that range was 7.8 w/w at 95.2% purity, with 3.8% w/w of ω-6 γ-linolenic acid (GLA) and 1.0% w/w of ω-3 α-linolenic (ALA) present as contaminants. This is the first report on the isolation of LA from CTO. The approach presented here can be applied to recover other valuable fatty acids. Furthermore, once the targeted fatty acid(s) are isolated, the rest of the TOFAs can be utilized for the production of biodiesel, biobased surfactants, or other valuable bioproducts.

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Jovanovic, Petar, Ljubica Dokic, and Branimir Maric. "Fatty acid composition of maize germ oil from high-oil hybrids wet-milling processing." Acta Periodica Technologica, no. 36 (2005): 43–50. http://dx.doi.org/10.2298/apt0536043j.

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Maize germ was obtained by wet-milling laboratory processing of domestic high-oil maize hybrids. After separation, the germ was subjected to extraction of maize oil. Fatty acid composition of maize germ oil was determined by gas chromatography. The results showed very high levels of unsaturated fatty acids and a constant sum of oleic and linoleic acids in oils of different maize hybrids.

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SAHASHI, Yuko, Hirotoshi ISHIZUKA, Seiji KOIKE, and Kazuaki SUZUKI. "Membrane Separation of Polyunsaturated Fatty Acids-rich Acylglycerols from Fish Oil." Journal of Japan Oil Chemists' Society 43, no. 2 (1994): 116–23. http://dx.doi.org/10.5650/jos1956.43.116.

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27

Escudero, Noel, Francisco J. Deive, María S. Álvarez, and Ana Rodríguez. "Plotting a nature-friendly separation process for recovering volatile fatty acids." Journal of Molecular Liquids 315 (October 2020): 113755. http://dx.doi.org/10.1016/j.molliq.2020.113755.

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Korte, Klaus, Kenneth R. Chien, and M. Linette Casey. "Separation and quantitation of fatty acids by high-performance liquid chromatography." Journal of Chromatography B: Biomedical Sciences and Applications 375 (January 1986): 225–31. http://dx.doi.org/10.1016/s0378-4347(00)83715-9.

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Schmitz, Oliver, and Siegmar Gäb. "Separation of isomeric hydroperoxides of unsaturated fatty acids by capillary electrophoresis." Journal of Chromatography A 767, no. 1-2 (April 1997): 249–53. http://dx.doi.org/10.1016/s0021-9673(97)00006-x.

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Steger, Alph, and H. W. Scheffers. "The separation of liquid and solid fatty acids by twitchell's method." Recueil des Travaux Chimiques des Pays-Bas 46, no. 6 (September 3, 2010): 402–8. http://dx.doi.org/10.1002/recl.19270460604.

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Bak, Changhyeon, Yeo-Myeong Yun, Jeong-Hoon Kim, and Seoktae Kang. "Electrodialytic separation of volatile fatty acids from hydrogen fermented food wastes." International Journal of Hydrogen Energy 44, no. 6 (February 2019): 3356–62. http://dx.doi.org/10.1016/j.ijhydene.2018.07.134.

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Sardenne, Fany, Nathalie Bodin, Jordan C. T. Latour, and Christopher W. McKindsey. "Influence of lipid separation on the trophic interpretation of fatty acids." Food Webs 24 (September 2020): e00146. http://dx.doi.org/10.1016/j.fooweb.2020.e00146.

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Poškus, Vilius, and Vida Vičkačkaitė. "Silver-coated monolithic silica column for separation of trans fatty acids." Separation Science Plus 1, no. 11 (November 2018): 738–45. http://dx.doi.org/10.1002/sscp.201800115.

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Yesil, Hatice, Hatice Taner, Filiz Ugur Nigiz, Nilufer Hilmioglu, and A. Evren Tugtas. "Pervaporative Separation of Mixed Volatile Fatty Acids: A Study Towards Integrated VFA Production and Separation." Waste and Biomass Valorization 11, no. 5 (November 13, 2018): 1737–53. http://dx.doi.org/10.1007/s12649-018-0504-6.

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Shen, Yihui, Zhilun Zhao, Luyuan Zhang, Lingyan Shi, Sanjid Shahriar, Robin B. Chan, Gilbert Di Paolo, and Wei Min. "Metabolic activity induces membrane phase separation in endoplasmic reticulum." Proceedings of the National Academy of Sciences 114, no. 51 (December 1, 2017): 13394–99. http://dx.doi.org/10.1073/pnas.1712555114.

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Membrane phase behavior has been well characterized in model membranes in vitro under thermodynamic equilibrium state. However, the widely observed differences between biological membranes and their in vitro counterparts are placing more emphasis on nonequilibrium factors, including influx and efflux of lipid molecules. The endoplasmic reticulum (ER) is the largest cellular membrane system and also the most metabolically active organelle responsible for lipid synthesis. However, how the nonequilibrium metabolic activity modulates ER membrane phase has not been investigated. Here, we studied the phase behavior of functional ER in the context of lipid metabolism. Utilizing advanced vibrational imaging technique, that is, stimulated Raman scattering microscopy, we discovered that metabolism of palmitate, a prevalent saturated fatty acid (SFA), could drive solid-like domain separation from the presumably uniformly fluidic ER membrane, a previously unknown phenomenon. The potential of various fatty acids to induce solid phase can be predicted by the transition temperatures of their major metabolites. Interplay between saturated and unsaturated fatty acids is also observed. Hence, our study sheds light on cellular membrane biophysics by underscoring the nonequilibrium metabolic status of living cell.

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Radunz, A., P. Heb, and G. H. Schmid. "Analysis of the Seed Lipids of Aleurites montana." Zeitschrift für Naturforschung C 53, no. 5-6 (June 1, 1998): 305–10. http://dx.doi.org/10.1515/znc-1998-5-602.

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Abstract The seed lipids of the Chinese tung-oil tree Aleurites montana are composed of 97.2% triglycerides, 2% phospholipids and of 0.8% glycolipids. In the triglycerides 67% of all fatty acids are α-eleostearic acid (configuration C18:3, ∆9 cis, ∆11 trans, ∆13 trans). This acid is bound in the triglycerides in the 1,3 position. Via mercury Il-acetate adducts and subsequent chromatography on silica gel a separation of this fatty acid from the seed fatty acids is possible. By this procedure an a-eleostearic acid-free tung-oil mixture is obtained, which consists by one half of C18:2, 25% of C18:1 and by 25% of the saturated fatty acids C16:0, C18:0 and C14:0.

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Heinzelmann, Sandra M., Nicole J. Bale, Ellen C. Hopmans, Jaap S. Sinninghe Damsté, Stefan Schouten, and Marcel T. J. van der Meer. "Critical Assessment of Glyco- and Phospholipid Separation by Using Silica Chromatography." Applied and Environmental Microbiology 80, no. 1 (October 25, 2013): 360–65. http://dx.doi.org/10.1128/aem.02817-13.

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ABSTRACTPhospholipid-derived fatty acids (PLFAs) are commonly used to characterize microbial communitiesin situand the phylogenetic positions of newly isolated microorganisms. PLFAs are obtained through separation of phospholipids from glycolipids and neutral lipids using silica column chromatography. We evaluated the performance of this separation method for the first time using direct detection of intact polar lipids (IPLs) with high-performance liquid chromatography–mass spectrometry (HPLC-MS). We show that under either standard or modified conditions, the phospholipid fraction contains not only phospholipids but also other lipid classes such as glycolipids, betaine lipids, and sulfoquinovosyldiacylglycerols. Thus, commonly reported PLFA compositions likely are not derived purely from phospholipids and perhaps may not be representative of fatty acids present in living microbes.

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IJmker, H. M., M. Gramblička, S. R. A. Kersten, A. G. J. van der Ham, and B. Schuur. "Acetic acid extraction from aqueous solutions using fatty acids." Separation and Purification Technology 125 (April 2014): 256–63. http://dx.doi.org/10.1016/j.seppur.2014.01.050.

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39

Japir, Abd Al-Wali, Jumat Salimon, Darfizzi Derawi, Badrul Hisham Yahaya, Murad Bahadi, Salah Al-Shujaʼa, and Muhammad Rahimi Yusop. "A highly efficient separation and physicochemical characteristics of saturated fatty acids from crude palm oil fatty acids mixture using methanol crystallisation method." OCL 25, no. 2 (February 26, 2018): A203. http://dx.doi.org/10.1051/ocl/2018003.

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The objective of the current study was to separate saturated fatty acids (SFAs) from high free fatty acid crude palm oil fatty acid mixture using the methanol crystallisation method. The development of methanol crystallisation method procedure was based on various parameters. The fatty acid composition was determined by using gas chromatography-flame ionisation detector (GC-FID) as Fatty Acid Methyl Esters. The highest percentage of SFAs was more than 89% with the percentage yield of 48.9% under the optimal conditions of the fatty acids-to-methanol ratio of 1:15 (w/v), the crystallisation temperature of −15 °C, and the crystallisation time of 24 hours, respectively. After a double crystallisation, the composition of separated SFAs contains 90% of palmitic acid (C16:0) as a major component and 5.8% of stearic acid (C18:0), respectively. Moreover, almost 4.2% of oleic acid (C18:1) was observed in the saturated solid product. Based on the results, the use of methanol as a crystallisation solvent is recommended because of its high efficiency, low cost, stability, obtainability, and comparative ease of recovery.

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Sinanoglou, Vassilia J., Irini F. Strati, Sotirios M. Bratakos, Charalampos Proestos, Panagiotis Zoumpoulakis, and Sofia Miniadis-Meimaroglou. "On the Combined Application of Iatroscan TLC-FID and GC-FID to Identify Total, Neutral, and Polar Lipids and Their Fatty Acids Extracted from Foods." ISRN Chromatography 2013 (January 15, 2013): 1–8. http://dx.doi.org/10.1155/2013/859024.

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An efficient separation and quantification of the individual neutral and polar lipid classes and their constituent fatty acids was achieved by the combination of two different detection techniques: Iatroscan TLC-FID and GC-FID. The solvent composition and ratio of development system, the sample size, the fidelity, and precision were tested in order to estimate the effectiveness of separation of individual neutral and polar lipid classes and the quantitative reproducibility of the Iatroscan TLC-FID technique. GC-FID method, with a high-quality capillary column, allowed sensitive and reproducible fatty acid qualitative and quantitative analyses, separation of fatty acid structural isomers (e.g., n-C16:0, iso-C16:0 and anteiso-C16:0), positional isomers (e.g., C18:1ω-9 and C18:1ω-7), geometrical isomers (cis-trans), and homologues (e.g., C16:0, C17:0, C18:0, etc.) in standards and complex lipid samples. Seventeen (17) lipid classes and fifty-two (52) saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids were identified and quantified, respectively, in samples of standard lipid and fatty acid mixtures, simulating the composition of natural lipids and their fatty acid methyl esters in common foods. The wide number of applications establishes this combination of Iatroscan TLC-FID and GC-FID methods as a powerful tool for lipid class and fatty acid analysis of any fat origin.

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Cable, M. L., A. M. Stockton, M. F. Mora, K. P. Hand, and P. A. Willis. "Microchip nonaqueous capillary electrophoresis of saturated fatty acids using a new fluorescent dye." Anal. Methods 6, no. 24 (2014): 9532–35. http://dx.doi.org/10.1039/c4ay01243g.

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Lolli, Veronica, Angela Marseglia, Gerardo Palla, Emanuela Zanardi, and Augusta Caligiani. "Determination of Cyclopropane Fatty Acids in Food of Animal Origin by 1H NMR." Journal of Analytical Methods in Chemistry 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/8034042.

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Cyclopropane fatty acids (CPFAs) are unusual fatty acids of microbial origin, recently detected in milk and dairy products. CPFAs have been demonstrated to be interesting molecular markers for authentication of dairy products obtained without ensiled feeds. Moreover, they can also be recognized as a new secondary component of human diet. Information is lacking on the presence of cyclic fatty acids in other food sources. Cyclopropane fatty acids have been detected by GC-MS analysis in cheese and other animal fats in concentration ranging from 200 to 1000 mg/kg fat, but in some cases, the complex fatty acid profile and the possible presence of interfering peaks make the separation not straightforward and the quantification uneasy. Therefore, a new reliable 1H NMR method was developed to detect and measure CPFA content in different foods of animal origin, based on the detection of the characteristic signals of cyclopropane ring. The 1H NMR (600 MHz) method showed detection limits comparable with those of full scan GC-MS, and it allowed the identification and quantitation of the cyclopropane fatty acids in different foods.

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Costa, Catarina G., Lambertus Dorland, Ulbe Holwerda, Isabel Tavares de Almeida, Bwee-Tien Poll-The, Cornelis Jakobs, and Marinus Duran. "Simultaneous analysis of plasma free fatty acids and their 3-hydroxy analogs in fatty acid β-oxidation disorders." Clinical Chemistry 44, no. 3 (March 1, 1998): 463–71. http://dx.doi.org/10.1093/clinchem/44.3.463.

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Abstract We present a new derivatization procedure for the simultaneous gas chromatographic–mass spectrometric analysis of free fatty acids and 3-hydroxyfatty acids in plasma. Derivatization of target compounds involved trifluoroacetylation of hydroxyl groups and tert-butyldimethylsilylation of the carboxyl groups. This new derivatization procedure had the advantage of allowing the complete baseline separation of free fatty acids and 3-hydroxyfatty acids while the superior gas chromatographic and mass spectrometric properties of tert-butyldimethylsilyl derivatives remained unchanged, permitting a sensitive analysis of the target compounds. Thirty-nine plasma samples from control subjects and patients with known defects of mitochondrial fatty acid β-oxidation were analyzed. A characteristic increase of long-chain 3-hydroxyfatty acids was observed for all of the long-chain 3-hydroxyacyl-CoA dehydrogenase-deficient and mitochondrial trifunctional protein-deficient plasma samples. For medium-chain acyl-CoA dehydrogenase deficiency and very-long-chain acyl-CoA dehydrogenase deficiency, decenoic and tetradecenoic acids, respectively, were the main abnormal fatty acids, whereas the multiple acyl-CoA dehydrogenase-deficient patients showed variable increases of these unusual intermediates. The results showed that this selective and sensitive method is a powerful tool in the diagnosis and monitoring of mitochondrial fatty acid β-oxidation disorders.

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Suhendra, Dedy, W. M. Z. Wan Yunus, Md Jelas Haron, Mahiran Basri, and Sidik Silong. "SEPARATION AND PRECONCENTRATION OF COPPER (II) ION BY FATTY HYDROXAMIC ACIDS IMMOBILIZED ONTO AMBERLITE XAD – 4 RESIN." Indonesian Journal of Chemistry 6, no. 2 (June 14, 2010): 165–69. http://dx.doi.org/10.22146/ijc.21754.

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A method of copper (II) ion preconcentration and separation from other ions by using a column containing fatty hydroxamic acids - loaded Amberlite XAD 4 resin (FHA-Amb) is described. Several factors, which affect the separation and preconcentration efficiency such as pH, sample volume, and concentration of eluent and flow rate, have been investigated. A quantitative recovery of copper (II) ion from FHA-Amb resin column was obtained using 10% HNO3 solutions as eluent with a preconcentration factor of 60. A method for separation of Cu(II) from Zn(II) and Cd(II) is proposed. A rapid sample throughput, a clean separation, a high preconcentration factor and simplicity are the main advantages in these analytical procedures. Keywords: extraction, preconcentration, fatty hydroxamic acid, copper (ii) ion, amberlite XAD-4

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Barnes, S., R. Dalhoff, J. Keller, P. Wilderer, and L. Kendall. "Investigation of membrane processes for the removal of volatile fatty acids." Water Science and Technology 47, no. 12 (June 1, 2003): 191–98. http://dx.doi.org/10.2166/wst.2003.0646.

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The accumulation of volatile fatty acids such as acetic acid can cause reactor pH problems and the inhibition of microorganisms utilised in anaerobic digestion processes. A cross-flow membrane process using Teflon and ion-exchange membranes was investigated as a means of separating acetic acid from pure acetic acid solution and rumen fluid. Acetic acid transfer across the Teflon membrane was dependent on the free acid concentration (CH3COOH) in the acid solution. Concurrent transfer of water was minimal due to the hydrophobic nature of the membrane. The strong base anionic exchange membrane facilitated the separation of acetic acid from both pure solutions and rumen fluid with flux again being dependent on the free acid gradient across the membrane. Flux rates were lower than other studies of diffusion dialysis, however, this may be partly attributed to improper preparation of the membrane. The currently achieved rates of transfer using these membranes are very low and are therefore not yet suitable for full-scale use in anaerobic digestion. Additional research is needed to achieve higher trans-membrane transport rates at reasonable costs.

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Andrikopoulos, Nikolaos K., Athanasia Siafaka-Kapadai, Nikoletta Yanovits-Argyriadis, and Constantinos A. Demopoulos. "Evidence for the Presence of Neutral Glycerylether Derivatives in Pollen Lipids of Pine Tree Pinus halepensis." Zeitschrift für Naturforschung C 41, no. 4 (April 1, 1986): 396–402. http://dx.doi.org/10.1515/znc-1986-0405.

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The separation and identification of glyceryl ether (G E ) derivatives from pollen neutral lipids of Pine tree Pinus halepensis (Miller) is described. The separation and purification of GE derivatives from the other lipid classes, especially from monoglycerides and diglycerides, was done by thin layer chromatography. The purified GE derivatives were examined by infrared spectrometry analyzed by gas liquid chromatography, and the glycerylether backbones were identified by gas chromatography-mass spectrometry of its isopropylidene derivatives. Fatty acids were detected as esterified constituents after mild alkaline hydrolysis of the GE fraction. The GE derivatives are characterized as 1-O-(di)hydroxyalke(die)nyl-glycerols, the side hydroxyl group(s) of the O-carbonchain being esterified mainly with saturated fatty acids.

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Salimon, Jumat. "FREE FATTY ACIDS SEPARATION FROM MALAYSIAN HIGH FREE FATTY ACID CRUDE PALM OIL USING MOLECULAR DISTILLATION." Malaysian Journal of Analytical Science 20, no. 5 (October 11, 2016): 1042–51. http://dx.doi.org/10.17576/mjas-2016-2005-08.

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E, Vilcacundo, Alvarez M, Silva M, Carpio C, Morales D, and Carrillo W. "FATTY ACIDS COMPOSITION OF TOCTE (JUGLANS NEOTROPICA DIELS) WALNUT FROM ECUADOR." Asian Journal of Pharmaceutical and Clinical Research 11, no. 2 (February 1, 2018): 395. http://dx.doi.org/10.22159/ajpcr.2018.v11i2.16344.

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Objective: The aim of this study was to determine the fatty acids composition in a tocte seeds oil (Juglans neotropica Diels) sample cultivated in Ecuador.Methods: Tocte oil was obtained from tocte seeds using the cold pressing method. Fatty acids analysis was carried out using the gas chromatography method with a mass selective detector (GC/MSD) and using the database Library NIST14.L to identify the compounds.Results: Methyl esters fatty acids were identified from tocte (J. neotropica Diels) walnut using the GC–MS analytical method. The total lipid content of tocte walnuts seeds of plants cultivated in Ecuador was of 49.01% of the total lipid content on fresh weight. Fatty acids were analyzed as methyl esters on a capillary column DB-WAX 122-7062 with a good separation of palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. The structure of methyl esters fatty acids was determined using the GC–MS. Tocte walnut presents 5.05% of palmitic acid, 2.26% of stearic acid, 19.50% of oleic acid, 65.81% of linoleic acid, and 2.79% linolenic acid of the total content of fatty acids in tocte oil. Fatty acids content reported in this study were similar to the data reported for other walnuts seeds.Conclusions: Tocte seeds are a good source of monounsaturated and polyunsaturated fatty acids. Tocte oil content oleic acid and with a good content of ɷ6 α-linoleic and ɷ3 α-linolenic. Tocte walnut can help reduce risk cardiovascular diseases in Ecuador for their good composition of fatty acids.

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Bahadi, Murad, Mohamad Firdaus Yusoff, Jumat Salimon, Abd Al-Wali Japir, and Darfizzi Derawi. "Optimization of Low-Temperature Methanol Crystallization for Unsaturated Fatty Acids Separation from Crude Palm Fatty Acids Mixture Using Response Surface Methodology." Asian Journal of Chemistry 31, no. 7 (May 21, 2019): 1617–25. http://dx.doi.org/10.14233/ajchem.2019.21974.

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Patokina, E. V., S. M. Alekseev, I. K. Sarycheva, and R. P. Evstigneeva. "Adductive crystallization of fatty acids with urea. II. Quantitative description of separation of binary mixture of ethyl esters of fatty acids." Pharmaceutical Chemistry Journal 19, no. 10 (October 1985): 714–18. http://dx.doi.org/10.1007/bf00767177.

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Journal articles on the topic 'Fatty acids – Separation'

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