Effect of extraction methods on lipid yield and fatty acid composition of lipid classes containing γ-linolenic acid extracted from fungi

The effect of extraction procedures on the lipid yield and fatty acid composition of total lipid and main lipid structures (phospholipids, diacylglycerols, triacylglycerols, free fatty acids, and sterol esters) of fungal biomass (Mucor mucedo CCF-1384) containing γ-linolenic acid (GLA) was investigated. Seventeen extraction methods, divided into three groups, were tested: six with chloroform/methanol, five with hexane/alcohols, and six with common solvents or mixtures. The chloroform/methanol procedure (2∶1) was selected as standard, where lipid yield (TL/DCW, total lipid per dry cell weight) was 17.8%, considered to be 100% of lipids present. All chloroform/methanol extractions yielded more than 83% recorvey of lipids. Use of hexane/isopropanol solvent systems led to a maximum of 75% recovery. The best lipid yield was achieved by a two-step extraction with ethanol and hexane (120%). Extraction efficiency of the other solvent systems reached a maximum of 73%. Triacylglycerols were the main structures of lipid isolated; only methanol-extracted lipid contained 58.5% phospholipids. The fatty acid content of total recovered lipid was variable and depended on both the lipid class composition and the solvent system. GLA concentrations in total lipids isolated by hexane/alcohol procedures (7.3–10.7%) are comparable with classical chloroform/methanol systems (6.5–10.0%). The maximal GLA yield was obtained with chloroform/methanol/n-butanol/water/0.1 M ethylenediaminetetraacetic acid (EDTA) (2∶1∶1∶1∶0.1, by vol) and after two-step extraction with ethanol and hexane (14.3 and 13.7 g GLA/kg DCW, respectively). The highest GLA content was analyzed in the phospholipid fraction (16.1%) after using chloroform/methanol/n-butanol/water/0.1 M EDTA (2∶1∶1∶1∶0.1, by vol). Remarkably low concentrations of polyunsaturated fatty acids were determined in the free fatty acid fraction.     

Determination and correlation solubility of 4-nitroimidazole in twelve pure solvents from 278.15 K to 323.15 K

In this paper, the solubility of 4-nitroimidazole in twelve pure solvents (toluene, benzene, 1,4-dioxane, acetonitrile, ethyl acetate, acetone, GBL, ethanol, methanol, n-butanol, DMF and NMP) were determined by using the laser monitoring system from 278.15 K to 323.15 K under 101.1 kPa, which are 0.00018–0.00070, 0.00021–0.00073, 0.00034–0.00092, 0.00038–0.00142, 0.00047–0.00120, 0.00126–0.00303, 0.00225–0.00517, 0.00310–0.00724, 0.00467–0.00982, 0.00453–0.01940, 0.01947–0.04652, and 0.04670–0.07452, respectively. At constant temperature, the mole fraction solubility of 4-nitroimidazole were increased as the following order: toluene < benzene < 1,4-dioxane < (ethyl acetate or acetonitrile) < acetone < GBL < ethanol < (methanol or n-butanol) < DMF < NMP, and the solubility of 4-nitroimidazole in (ethyl acetate, acetonitrile) and (methanol, n-butanol) had an intersection point at 297.55 K and 281.85 K, respectively. The solubility of 4-nitroimidazole could be increased with increasing temperature in twelve pure solvents. The ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation were used to correlate the experimental values. The experimental solubility values were employed to calculate the standard dissolution enthalpy, standard dissolution entropy and Gibbs energy. The dissolution of 4-nitroimidazole could be an endothermic process in twelve pure solvents. The determination and fitting solubility of 4-nitroimidazole have important guiding significance for the purification and crystallization of its preparation process.     

Surface properties of urethane coating containing perfluorinated additives

A series of alcohols containing perfluorinated segments F(CF₂)_m(CH₂)_n–OH (m = 8, 10 and n = 10) were synthesized. First, the alcohols were reacted with fatty acid to produce several esters (i.e. F(CF₂)_m(CH₂)_n–OOC–R (m = 8, 10 and n = 10)) containing perfluoro group by a condensation reaction, and characterized by FT-IR, GC, and surface tension. The esters were found to be soluble in ethyl ether, toluene, hexane, ethyl acetate, chloroform, and acetone, but insoluble in methyl alcohol, ethyl alcohol and isopropyl alcohol. Preliminary experiments on 1,2-dichloroethane solutions showed a remarkable decrease of surface tension upon the addition of the esters. In addition, the esters using urethane resin were coated onto a glass substrate using a spin-coating method. It was found that the contact angle of coated films ranged from 100° to 120°, depending on the structure of fatty acid esters. As a part of experiments, the water-repellency of coated paper and cotton was evaluated, and it was observed that the water droplet on the film surface was not permeated for 2 weeks.     

Influence of Some Organic Additives on the Extractive Separation of Americium(III) by Sulfoxides

Abstract

The solvent extraction behavior of americium(III) from aqueous nitrate media by two long-chain aliphatic sulfoxides has been examined systematically in the presence of several water-miscible organic solvents to study their possible synergistic effect on metal ion extraction. Methanol, ethanol, n- and isopropanol, n-butanol, dioxane, acetone, as well as acetonitrile, were employed as the organic component of the mixed (polar) phase. These additives affected the extraction to varying degrees. Extractability of Am increased 5 to 10-fold with increasing concentration of some of these additives, with the maximum enhancement being observed in the presence of acetone or acetonitrile. However, alcohols are generally very poor in this respect. Possible reasons for such behavior are briefly discussed. The distribution of several common contaminants was also investigated at the optimum condition for americium extraction.     

Cottonseed extraction with mixtures of acetone and hexane

Cottonseed flakes were extracted with mixtures of n-hexane and acetone, with the concentration of acetone varying between 10 and 75%. Adding small amounts of acetone (≤25%) to n-hexane significantly increased the extraction of free and total gossypol from cottonseed flakes. Sensory testing detected no difference in the odor of cottonseed meals produced either by extraction with 100% n-hexane or by extraction with a 10∶90 (vol/vol) mixture of acetone/hexane. More than 80% of the free gossypol was removed by the 10∶90 mixture of acetone/hexane, whereas pure n-hexane extracted about 47% of the free gossypol from cottonseed flakes. A solvent mixture containing 25% acetone removed nearly 90% of the free gossypol that was removable by extraction with pure acetone; the residual meal had only a minimal increase in odor. In contrast, cottonseed meals produced by extraction with pure acetone had a much higher odor intensity. The composition of the cottonseed crude oil was insignificantly affected by the acetone concentration of the extraction solvent. The results indicate that mixtures of acetone and n-hexane can be used as extraction solvents to produce cottonseed crude oil without the concomitant development of odorous meals.     

Analysis of unbound materials in carbon‐black‐filled NR vulcanizates

Extraction of unbound materials from carbon‐black‐filled natural rubber (NR) vulcanizates with different cure systems was studied using various solvents with different dielectric constants of n‐hexane, toluene, THF, acetone, and acetonitrile. The extraction was performed at room temperature and 40°C for 2 days and in the boiling solvent for 8 h. Amounts of extracted materials from the NR vulcanizates increase by increasing the temperature. Amounts of extracted materials from the NR vulcanizates with n‐hexane, toluene, and THF are more than those with acetone and acetonitrile. Amounts of extracted materials from the NR vulcanizate with a high crosslink density are less than those from the NR vulcanizate with a low one. Thermogravimetric analysis of the NR vulcanizates before and after the extraction were carried out to investigate components of the extracted materials. It was found that there were polymer components and metal complexes, as well as organic matters with a low molecular weight in the extracted materials. Abilities of the solvents to extract unbound materials from the NR vulcanizates were discussed. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1995–2005, 1999     

Phase Separation of Lactan Gum from Fermentation Broths by Addition of Water-Miscible Organic Solvents

Abstract

A microbial polysaccharide (lactan gum) produced by bacterium ATCC 55046 was precipitated from fermentation broths by the addition of ethanol, acetone, isopropanol, or tert-butanol. Compositions of the precipitate and supernatant phases were determined as a function of organic solvent concentration and used to construct binodal solubility curves. Lactan did not precipitate at bulk-mixture organic solvent concentrations below 35% (wt) ethanol, 35% acetone, 33% isopropanol, or 25% tert-butanol. At organic solvent concentrations just exceeding the solubility transition point, the precipitates were soft, moist, and sponge-like in texture, with low lactan concentrations. At higher organic solvent concentrations the precipitates were compact and dense. The maximum lactan concentration in the precipitate was 25–37%, depending on the organic solvent type and concentration. Increasing the organic solvent concentration beyond 50% for ethanol, or 70% for acetone, decreased the lactan concentration in the precipitate. No such decrease occurred for isopropanol and tert-butanol. Thus, organic solvent usage, from greatest to least, was in the order ethanol, acetone, isopropanol, and tert-butanol, but the maximum lactan concentration in the precipitate, from greatest to least, was in the order acetone, isopropanol, ethanol, and tert-butanol.     

Solubility of propylene gas in octane and various polar solvents

Propene gas solubilities at 101.3 kPa pressure are reported in n-octane, chlorobenzene, acetone, acetic acid, ethyl acetate, n-butanol, N-N-dimethyl formamide (DMF) and ethylene glycol for a range of temperatures. These data, along with data from the literature, were used to show the qualitative effects of unsaturation of the gas component on the solubility in various solvents ranging from non-polar to highly polar and associated solvents. This involved a comparison, when data were available, of the solubilities of ethane, ethylene and acetylene, then of butane, isobutane, isobutylene, trans-2-butene and 1,3-butadiene as well as of propane and propene (propylene). The differences in solubilities could be explained using solubilities expressed as a molecular interaction parameter (mip) and by identifying several different types of molecular interactions. For associating solvents these effects can be summarized as follows: mip of acetylene > mip of ethylene > mip of ethane, also mip of propylene > mip of propane and mip of butadiene > mip of isobutylene≥ mip of trans-2-butylene > mip of butane > mip of isobutane.     

Modification of bed-coking batch with tar derived from Mongolian and Russian lignite

Quantitative characteristics are presented for the bitumen extracted from Podmoskovnyi, Kansko-Achinsk, Irkutsk, Baganursk, and Tugrugnursk lignite and the humic acids from the Tugrugnursk deposit by polar solvents (hexane, diethyl ether, acetone, chloroform, benzene, toluene, 1 : 1 alcohol-benzene mixture, pyridine, and acetic acid).     

Bitumen from Mongolian and Russian lignite

Quantitative characteristics are presented for the bitumen extracted from Podmoskovnyi, Kansko-Achinsk, Irkutsk, Baganursk, and Tugrugnursk lignite and the humic acids from the Tugrugnursk deposit by polar solvents (hexane, diethyl ether, acetone, chloroform, benzene, toluene, 1 : 1 alcohol-benzene mixture, pyridine, and acetic acid).     

Low-temperature flow properties of vegetable oil/cosolvent blend diesel fuels

Vegetable oils are an attractive renewable source for alternative diesel fuels. However, the relatively high kinematic viscosity of vegetable oils must be reduced to make them more compatible with conventional compression-ignition engines and fuel systems. Cosolvent blending is a low-cost and easy-to-adapt technology that reduces viscosity by diluting the vegetable oil with a low-M.W. alcohol (methanol or ethanol). The cosolvent (A), which consists of one or more amphiphilic compounds, is added to solubilize the otherwise nearly immiscible oil-polar alcohol mixture. This work investigates cold flow properties and phase equilibrium behavior associated with blends consisting of soybean oil (SBO) and methanol where A=8∶1 (mol) n-butanol/oleyl alcohol; 6∶1 (mol) 2-octanol/triethylammonium linoleate; and 4∶1 (mol) 2-octanol/Unadol 40 (alcohols from SBO FA); and a blend of 2∶1 (vol/vol) No. 2 diesel fuel/SBO and 95% ethanol where A=n-butanol. Cloud point (CP), pour point, cold filter plugging point (CFPP), and low-temperature flow test (LTFT) results were compared with corresponding phase separation temperature (T _ϕ) data measured at equilibrium. Although CP data were measured under non-equilibrium experimental conditions, a nearly linear correlation was found between T _ϕ and CP. Statistical analysis showed that T _ϕ may also be correlated with CFPP and LTFT. Analysis of heating and cooling DSC curves indicated that peak temperatures may be employed to predict cold flow properties and T _ϕ behavior for SBO/cosolvent blends. Cooling curve parameters correlated more readily than heating curve parameters. Finally, relatively low quantities of heat evolved during freezing indicated that crystallization in the SBO/cosolvent blends studied in this work occurs easily during cooling.     

In-situ alcoholysis of soybean oil

In-situ alcoholysis of soybean oil with methanol, ethanol,n-propanol, andn-butanol was investigated, as well as the extraction of the oil with these solvents, to explain the progress ofin-situ alcoholysis and to determine the parameters that affect this reaction. Because methanol is a poor solvent for soybean oil, the amount of oil dissolved in methanol and converted to methyl esters was low afterin-situ alcoholysis. Ethyl, propyl, and butyl esters of soybean fatty acids could be obtained in high yields fromin-situ alcoholysis of soybean oil with these alcohols.In-situ alcoholysis proceeded through dissolution and alcoholysis of triglycerides successively, and the overall reaction rate was determined by the extraction and alcoholysis rates. The parameters, affecting yield and purity of the product esters, were mainly those that favor extraction rate.     

Optimization of an Oil Extraction Process for Algae from the Treatment of Manure Effluent

Increasing interest in the coupling of biological wastewater treatment processes with the generation of value-added products (such as oil containing ω-3 fatty acids (FA)) has stimulated efforts in adapting extraction methods for treatment byproducts. This study’s objective was to compare a high temperature/pressure extraction method (accelerated solvent extraction) (ASE) and a manual extraction method (modified Folch extraction) with regard to their ability to extract total oil from three algae samples from the treatment of dairy manure effluent. The efficiency of total oil and FA extraction with three solvents (chloroform/methanol, isopropanol/hexane, and hexane) was also evaluated using the ASE method. Results showed that the ASE method yielded higher values for total oil content compared to the Folch method but similar values for FA content and composition after four extraction cycles with chloroform/methanol. However, the ASE method yielded much higher amounts of FA in the first cycle (85–95% of total extracted) compared to the Folch method (44–55% of total extracted in the first cycle). As expected, the extraction efficiency of the ASE method for FA was dependent on the extraction solvent. FA content values using ASE with chloroform/methanol > isopropanol/hexane > hexane. FA content values using the Folch method or ASE with chloroform/methanol were not significantly influenced by sample particle size within the size range of 0.1–1 mm.     

Rapid separation of the major phospholipid classes on a single aminopropyl cartridge

A rapid method for the separation of the individual phospholipid classes phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI) by a single solid-phase extraction was developed. PC, PE, PS and PI were sequentially eluted from aminopropyl bonded silica with acetonitrile/n-propanol (2∶1, vol/vol), methanol, isopropanol/methanolic HCl (4∶1, vol/vol) and methanol/methanolic HCl (9∶1, vol/vol). Standard recoveries were over 95% for PC and PE and over 85% for PS and PI with undistorted fatty acid composition. The separation of complex lipid mixtures on aminopropyl minicolumns can be refined to the level of individual phospholipid classes.     

In Situ Reflection–Absorption Infrared Spectroscopy at the Liquid–Solid Interface: Decomposition of Organic Molecules on Polycrystalline Platinum Substrates

The room-temperature adsorption and surface chemistry of several categories of organic molecules used as reactants or solvents in liquid-phase catalysis, of carboxylic acids, esters, aldehydes, acetone, alcohols and ethers in particular, were characterized in situ on polycrystalline Pt in the presence of the liquid phase by reflection-absorption infrared spectroscopy (RAIRS). For carboxylic acids and esters it was found that the propensity for decomposition and CO formation follows a formic acid ? methyl formate, ethyl formate > acetic acid, propionic acid, acrylic acid, ethyl acetate sequence. For aldehydes and acetone, the observed trend is formaldehyde ? acetaldehyde > acrolein, crotonaldehyde > propionaldehyde, acetone. Virtually no adsorbed CO was detected when Pt surfaces were exposed to liquid solutions of either alcohols or ethers. The observed trends could be correlated with the corresponding molecular structures. They are discussed in the context of previous results obtained from studies under ultrahigh vacuum (UHV) and under electro-oxidation conditions.     

Fast Esterification of Acetic Acid with Short Chain Alcohols in Microchannel Reactor

Microchannel reactor was used for the fast synthesis of acetic acid esters, including methyl acetate, ethyl acetate, n-propyl acetate and n-butyl acetate. Effects of the inner diameter of microchannel reactors, dosage of catalyst, residence time, reaction temperature and molar ratio of alcohol to acetic acid on yields of esters were studied in the p-toluene sulfonic acid-catalyzed homogeneous esterification of acetic acid with alcohols. Yields of acetic acid ester reached 74.0, 70.1, 97.2 and 92.2% when methanol, ethanol, n-propanol and n-butanol were used as the alcohols, respectively and the residence time was of 14.7 min.     

Correlation of solubility data: IV. Prediction of solubilities of homologous and analogous long chain compounds in related solvents

A new method of correlation and prediction of solubility data for long chain compounds is described. It is based on the linear relationship between 1/T_a and 1/T_r derived from the freezing point depression equation. T_a and T_r represent temperatures in degrees Kelvin at which the mole % solubility of a compound, a, in a given solvent is the same as that of an analogous reference compound, r, in a related solvent. The validity of the method has been confirmed by applying it to the extensive literature data on the solubilities of saturated and unsaturated fatty acids. Four families of related solvents were examined: (a) benzene, hexane, cyclohexane, chlorobenzene,o-xylene and toluene; (b) acetone, butanone, ethyl acetate and butyl acetate; (c) isopropanol, 95% ethanol, butanol,p-dioxane and diethyl ether; and (d) carbon tetrachloride and 1,2-chloroethane. Complete solubility data for a compound can be predicted from the linear 1/T_a vs. 1/T_r plot based on the melting point and one experimental solubility determination. ARS, USDA.     

Alcoholysis of palm oil mid-fraction by lipase from Rhizopus rhizopodiformis

A mycelial lipase from Rhizopus rhizopodiformis was prepared in fragment form. The lipase was examined to catalyze the alcoholysis of palm oil mid-fraction (PMF) in organic solvents. High percentage conversions of PMF to alkyl esters were achieved when methanol or propanol was used as acyl acceptor. Of the two most prevalent fatty acids in PMF, palmitic acid seemed to be preferred over oleic acid in the formation of methyl and propyl esters. The optimal ratio of oil to methanol in the alcoholysis reaction is 1 to 2 moles. The lipase exhibited high alcoholysis activities in nonpolar solvents (log P>2), such as hexane, benzene, toluene, and heptane. The enzyme showed exceptionally high thermostability.     

Pentavalent vanadium ion–cellulose thiocarbonate redox-system induced grafting of methyl methacrylate and other vinyl monomers onto cotton fabric

Cellulose thiocarbonate was prepared by reacting cotton cellulose fabric with carbon disulphide in the presence of sodium hydroxide. The treated fabric formed, with pentavalent vanadium ion, an effective redox system capable of initiating grafting of methyl methacrylate (MMA) and other monomers no+o the cotton fabric. The dependence of grafting on vanadium concentration, pH of the polymerization medium, temperature and duration of grafting, nature and concentration of monomer, and solvent/water ratio was studied. The results indicated that increasing the pentavalent vanadium (V^v) concentration up to 60 mmol/L was accompanied by enhancement in the rate of grafting; the latter was not affected by further increase in V^v concentration. Maximum grafting yield was achieved at pH 2; grafting fell greatly at higher pH. The rate of grafting followed the order: 70° > 60° > 50°C. The graft yield increased significantly by increasing the MMA concentration from 0.5 to 5%. Of the solvents studied, n-propanol and isopropanol enhanced the grafting rate provided that a solvent/water ratio of 5 : 95 was used; a higher solvent ratio decreased the magnitude of grafting. Other solvents, namely, methanol, ethanol, n-butanol, and acetone, in any proportion, decreased the rate of grafting. With the monomer used, the graft yield followed the order: methyl methacrylate > methyl acrylate > methacrylic acid > ethyl methacrylate > acrylic acid. Also reported was a tentative mechanism for vinyl-graft copolymerization onto cotton fabric using cellulose thiocarbonate-V^v. © 1993 John Wiley & Sons, Inc.     

Lipase-catalyzed synthesis of ferulate esters

Four commercially available esterases were screened for their ability to esterify ferulic acid (4-hydroxy-3-methoxy cinnamate). Novozym^® 435 was found to be the only one of those screened to convert ferulic acid to ethyl and octyl ferulate at 20 and 14% yields, respectively. The highest percentage conversion was obtained using a 1∶1 mole ratio of alcohol to ferulic acid in stirred batch reactions in anhydrous 2-methyl-2-propanol at 60°C using one equivalent (wt/wt based on ferulic acid) of Novozym 435. Increased water content and a higher alcohol/ethyl ferulate ratio had adverse effects on the lipase-catalyzed esterification. The Novozym 435 activity was tested in less polar solvents (anhydrous toluene and hexane) by monitoring the alcoholysis of ethyl ferulate with 1-octanol, which resulted in a 50% yield of octyl ferulate. The alcoholysis was improved to 83% by applying a 16 mm Hg vacuum for 5 min every 24 h to remove the ethanol co-product. The optimal alcoholysis parameters were applied to the alcoholysis of ethyl ferulate with monoolein and the transesterification with triolein. The transesterification of ethyl ferulate with triolein in anhydrous toluene produced a combined 44% yield of ferulyl monoolein and ferulyl diolein, a 20% greater yield than that obtained for alcoholysis using monoolein. The highest yield, 77%, of ferulyl monoolein and ferulyl diolein was achieved using a threefold excess of neat triolein. The lipase-catalyzed transesterification of ethyl ferulate with triolein appears to be a technically feasible route to ferulyl-substituted acylglycerols, which are potentially useful sunscreen ingredients.