Extraction of ethyl and methyl esters of polyunsaturated fatty acids with aqueous silver nitrate solutions

Teramoto, Masaaki; Matsuyama, Hideto; Ohnishi, Naofumi; Uwagawa, Sadamu; Nakai, Katsuya

doi:10.1021/ie00026a026

Cited by 40 publications

(21 citation statements)

References 9 publications

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“…This value agreed with that reported for the solvent extraction between organic and silver nitrate aqueous solutions (16).…”

Section: Silver Ion Density and Liquid Permeability Of Porous Membranesupporting

confidence: 92%

“…The silver ion density of 5.1 mol per kg of the trunk porous hollow-fiber membrane is comparable to the silver ion concentration of silver nitrate aqueous solution used in solvent extraction (16). The ordinate is the dimensionless effluent concentration defined as the concentration ratio of the effluent to the feed.…”

Section: Silver Ion Density and Liquid Permeability Of Porous Membranementioning

confidence: 99%

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Selective binding of docosahexaenoic acid ethyl ester to a silver‐ion‐loaded porous hollow‐fiber membrane

Shibasaki

Irimoto

Kim

et al. 1999

J Americ Oil Chem Soc

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Silver ions were loaded at a density of 1 mmol/g onto a sulfonic acid group-containing porous hollow-fiber membrane prepared by radiation-induced graft polymerization of an epoxy group-containing monomer with subsequent modification by reaction with sodium sulfite. The permeability (i.e., permeation flow rate per inside surface area of the hollow fiber) of 4.6% wt/vol bonito oil ethyl ester solution in water/ethanol (7.5:92.5, vol/vol) was 1.7 m/h at a permeation pressure of 0.1 MPa. Breakthrough curves (i.e., concentration changes of the effluent with increasing effluent volume) obtained with docosahexaenoic acid ethyl ester (DHA-Et) overlapped, irrespective of the permeation flow rate. This indicates that a higher rate of DHA-Et adsorption onto the silver ions on the membrane was attained with increasing permeation flow rate. DHA-Et, which was selectively bound to the membrane, was quantitatively eluted with acetonitrile as an eluent. The adsorption characteristics (i.e., binding rate, selectivity and durability for repeated use) of DHA-Et using the silver ion loaded porous hollow-fiber membrane were demonstrated. Feasibility studies will enable comparison of the purification cost of DHA-Et among the other purification techniques.Paper no. J8978 in JAOCS 76, 771-775 (July 1999).KEY WORDS: Bonito oil, DHA, permeation flow, porous hollow-fiber membrane, silver ion binding.Eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) are representative long-chain n-3 fatty acids. Since EPA and DHA are powerful competitive inhibitors of lipoxygenases and cyclooxygenases, the intake of these polyunsaturated fatty acids (PUFA) may have fundamental consequences for cellular and tissue functions. DHA is considered to be a promising pharmaceutical because of its beneficial effects on the retina and brain (1).Conventionally, DHA has been purified by vacuum distillation, column chromatography using octadecyl-group-containing silica beads, and supercritical fluid extraction. Stein and Slawson (2) used silicic acid-silver nitrate adsorbents for chromatography, based on a weak interaction between silver ions and the double bonds of PUFA. Recently, liquid extraction using a silver nitrate aqueous solution has been proposed (3). A liquid membrane using the silver nitrate aqueous solution as the water phase was applied for the extraction of EPA (4) and PUFA (5). Moreover, a silver ion-loaded cation-exchange membrane exhibited considerable differences in the permeability rates of PUFA with different numbers of double bonds (6). A silver ion-sandwiched clay material has been suggested for DHA purification (7). We have prepared porous membranes containing functional groups: chelating porous membranes (8) for collecting metal ions, and ion-exchange (9), hydrophobic (10) and affinity (11,12) porous membranes for collecting proteins. These membranes realize a high collection rate because of convectionaided transport of target ions and proteins to the functional groups. Membrane chromatography using porous functional me...

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“…This value agreed with that reported for the solvent extraction between organic and silver nitrate aqueous solutions (16).…”

Section: Silver Ion Density and Liquid Permeability Of Porous Membranesupporting

confidence: 92%

Section: Silver Ion Density and Liquid Permeability Of Porous Membranementioning

confidence: 99%

Selective binding of docosahexaenoic acid ethyl ester to a silver‐ion‐loaded porous hollow‐fiber membrane

Shibasaki

Irimoto

Kim

et al. 1999

J Americ Oil Chem Soc

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show abstract

“…Teramoto et al considered that DHA-Et reacts with silver ion in an aqueous bulk. 8 However, we cannot easily accept it because DHAEt would adsorb on oil/water interface. Figure 3 shows the relationship between interfacial tension and DHA-Et concentration in the organic phase.…”

Section: Theoretical Sectionmentioning

confidence: 99%

“…For the last several decades, some techniques for separation and purification of PUFAs were proposed, studied, and developed. [4][5][6][7][8][9][10][11][12][13] Among the techniques, the separation method of PUFA ethyl esters (PUFA-Ets) utilizing liquid-liquid extraction with silver ion 8 has attracted attention as an effective method and has been expanded into more effective techniques using supported liquid membrane (SLM), 9,10 emulsion liquid membrane (ELM), 11,12 and slug flow prepared by microchip. 13 Above all, we have directed our attention to utilizing slug flow prepared by microchip.…”

Section: Introductionmentioning

confidence: 99%

Modeling of extraction behavior of docosahexaenoic acid ethyl ester by utilizing slug flow prepared by microreactor

Kamio¹,

Seike²,

Yoshizawa³

et al. 2009

AIChE Journal

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in Wiley InterScience (www.interscience.wiley.com).The liquid-liquid extraction dynamics of an ethyl ester of docosahexaenoic acid (DHA-Et) with silver ion was investigated. The kinetic model was derived according to the following stepwise processes: Diffusion of DHA-Et across the organic film, complex-formation between DHA-Et and silver ion at the interface, and diffusion of extracted complex across the aqueous film. The kinetic parameters for the complex-formation reaction were determined from the investigation with the stirred transfer cell. With the proposed model and determined parameters, we predicted the uptakes of DHA-Et for the extraction system utilizing a slug flow prepared by a microchip. The calculated uptakes showed good correlation to the experimental data. The theoretical investigation suggested that the fast equilibration realized for the slug flow extraction system was due to the large specific interfacial area of the slug caused by the presence of wall film and the thin liquid film caused by the internal circulation.

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“…Infant formula applications require a specific balance of PUFAs, including both omega-6 and omega-3 fatty acids (Innis et al, 2002), which also necessitates enrichment of target fatty acids from mixed oils. Many techniques for the enrichment of PUFAs from mixtures containing saturated fatty acids have been reported, including chain length-dependent extraction with supercritical carbon dioxide (Alkio et al, 2000), selective enzymatic hydrolysis, or transesterification with lipase (McNeill et al, 1996), low temperature crystallization, especially in organic solvents (Schlenk, 1961), silver ion-olefin interaction methods, including liquid extraction (Teramoto et al, 1994), and argentation chromatography (Nikolova-Damyanova, 2003) and urea inclusion (Schlenk and Holman, 1950).…”

Section: Introductionmentioning

confidence: 99%

Separation of polyunsaturated fatty acids by selective inclusion in guanidinium‐1,5‐naphthalenedisulfonate‐2‐methoxyethanol host networks

Voogt

Blanch

2005

Biotech & Bioengineering

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Hydrogen-bonded networks composed of guanidinium (G) and 1,5-naphthalenedisulfonate (NDS) have been developed for the selective inclusion and separation of fatty acid esters based on their degree of unsaturation. Porous crystalline networks have been synthesized and include fatty acid esters during crystallization from both methanol and 2-methoxyethanol. Crystalline networks formed in methanol are selective for the inclusion of saturates in preference to polyunsaturated fatty acid methyl esters, but their applicability is limited by the competing inclusion of the solvent methanol. In 2-methoxyethanol, a three-component host structure is formed that provides 4.1 x 4.7 A2 pores which are also selective for saturated fatty acid ester inclusion. These networks do not suffer from the competing inclusion of the solvent 2-methoxyethanol as is the case with methanol, and thus complete removal of initial saturated fatty acid 2-methoxyethyl esters is possible. Binary selectivity experiments on mixtures of the 2-methoxyethyl esters of saturated stearic acid and the omega-3 fatty acid alpha-linolenic acid reveal that this three-component network structure provides nearly complete resolution of these two guests in the crystal and filtrate fractions. Separation of the 2-methoxyethyl esters of alpha-linolenic acid from the monounsaturated oleic acid is also possible, although with decreased efficiency in comparison to removal of the saturated fatty acid ester.

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Extraction of ethyl and methyl esters of polyunsaturated fatty acids with aqueous silver nitrate solutions

Cited by 40 publications

References 9 publications

Selective binding of docosahexaenoic acid ethyl ester to a silver‐ion‐loaded porous hollow‐fiber membrane

Selective binding of docosahexaenoic acid ethyl ester to a silver‐ion‐loaded porous hollow‐fiber membrane

Modeling of extraction behavior of docosahexaenoic acid ethyl ester by utilizing slug flow prepared by microreactor

Separation of polyunsaturated fatty acids by selective inclusion in guanidinium‐1,5‐naphthalenedisulfonate‐2‐methoxyethanol host networks

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