Extraction of Material from Oil Paints by Solvents

2002 ◽  
Vol 712 ◽  
Author(s):  
David Erhardt ◽  
Roland H. Cunningham ◽  
Sirpa Räsänen
Keyword(s):  
Fatty Acids ◽  
Saturated Fatty Acids ◽  
Paint Film ◽  
Short Chain Fatty Acids ◽  
Solvent Exposure ◽  
Crosslinking Process ◽  
Oil Paints ◽  
Paint Films ◽  
Hydrolysis Of ◽  
Soluble Material

ABSTRACTDrying oils used to formulate oil paints consist primarily of polyunsaturated triglycerides, along with smaller amounts of mono- and diglycerides, free fatty acids, and other compounds such as sterols. The drying of oils occurs through an oxidative crosslinking process that also produces smaller scission products such as short chain fatty acids and diacids. Compounds that are not attached to the crosslinked oil matrix include glycerin, the unreactive free saturated fatty acids and their glycerides, soaps of fatty acids produced by reaction with metal ions from the pigment, and scission products. As the oil ages, additional soluble material is produced by hydrolysis of glyceride esters. These relatively low molecular weight compounds can be extracted by exposure to solvents, as occurs during the cleaning of paintings. Excessive extraction of material canembrittle the paint film and affect the appearance of the paint. This paper examines the types and amounts of compounds extracted from oil paint films as a function of solvent, exposure time, pigment, and age of the paint. The results indicate that solvents vary more in the speed that they extract material than in their selectivity. The composition of the extracts is consistent with predictions based on the mechanisms of the drying and aging processes. These results confirm the importance of using the least polar solvent possible to clean paintings and to formulate varnishes.

Lipids of the fin whale (Balaenoptera physalus) from North Atlantic waters. IV. Fin whale milk

1968 ◽  
Vol 46 (3) ◽  
pp. 197-203 ◽  
Author(s):  
R. G. Ackman ◽  
C. A. Eaton ◽  
S. N. Hooper
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Polyunsaturated Fatty Acids ◽  
Total Lipid ◽  
Iodine Value ◽  
North Atlantic ◽  
Methyl Esters ◽  
Short Chain Fatty Acids ◽  
Fin Whale ◽  
Hydrolysis Of

Fatty acid compositions were determined for total lipid (17.5% of the milk and > 95% triglycerides), 2-monoglyceride obtained by enzymatic hydrolysis of isolated triglyceride, and isolated phospholipid (~1% of total lipids). The total lipid fatty acids of the milk had a composition similar to fin whale depot fat but were enriched in hexadecanoic acid and polyunsaturated fatty acids at the expense of monoethylenic acids; correspondingly the iodine value of 136 (methyl esters) was higher than the normal range (105–120) of North Atlantic fin whale blubber oils. Over 80% of the fatty acids in the 2-position of the triglycerides were accounted for by relatively short chain fatty acids, especially hexadecanoic (54.6%), tetradecanoic (13.7%), and hexadecenoic (11.2%), so that the ester iodine value was only 48. The milk phospholipids had a fatty acid composition basically similar to that of liver phospholipids (methyl ester iodine value 120) with somewhat more polyunsaturated fatty acids and accordingly an iodine value of 144 for methyl esters.

THE MODE OF ACTION OF PANCREATIC LIPASE ON MILK FAT GLYCERIDES

1965 ◽  
Vol 43 (11) ◽  
pp. 1799-1805 ◽  
Author(s):  
A. Boudreau ◽  
J. M. deMan
Keyword(s):  
Fatty Acids ◽  
Pancreatic Lipase ◽  
Milk Fat ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Specific Distribution ◽  
Hydrolysis Rates ◽  
Hydrolysis Of ◽  
Palmitic Acids ◽  
Chain Fatty Acids

Hydrolysis of tricaprylin by pancreatic lipase resulted in a stepwise hydrolysis, triglyceride to diglyceride to monoglyceride, as has been obtained with long-chain triglycerides. However, hydrolysis rates were much faster and considerable amounts of free glycerol were formed. Hydrolysis of an equimolar mixture of tricaprylin and triolein indicated that some of the short-chain fatty acid was released from the 2-position before all of the oleic acid was released from the 1-position. Hydrolysis of genuine and randomized milk fat resulted in preferential hydrolysis of glycerides containing short-chain fatty acids. This phenomenon was not dependent on a specific distribution of these acids, since it also occurred with the randomized fat. It was concluded that part of the short-chain fatty acids of milk fat is located in the 2-position. The distribution of caprylic and capric acids between the 1- and 2-positions is approximately at random. Lauric, myristic, and palmitic acids are predominantly located in the 2-position, and stearic and oleic acids in the 1-position, of milk fat glycerides.

Examination of the Photochemical Curing and Degradation of Oil Paints by Laser Raman Spectroscopy

1997 ◽  
Vol 51 (8) ◽  
pp. 1218-1223 ◽  
Author(s):  
Seiichiro Higuchi ◽  
Tosimitsu Hamada ◽  
Yohichi Gohshi
Keyword(s):  
Raman Spectroscopy ◽  
Degradation Mechanism ◽  
Paint Film ◽  
Laser Raman Spectroscopy ◽  
Polymerization Reaction ◽  
Laser Raman ◽  
Curing Reaction ◽  
Oil Paints ◽  
Paint Films ◽  
Reaction Schemes

In the present study, the curing and the degradation of oil paints by irradiation with ultraviolet light was investigated by laser Raman spectroscopy. At present, the curing reaction of oil paints is interpreted by several reaction schemes, although none of them is considered to be based on definite experimental evidence. The most typical examples are as follows: one is the radical termination reaction of the crosslinking type; the other, the polymerization reaction of the Diels—Alder reaction (diene reaction) type. In the present investigation, oil paint film (ZnO White and TiO2 White) was irradiated with a Xe lamp, and the time dependence of the Raman spectra of the films was examined. It is shown that the curing reaction cannot be explained by either of the above-mentioned reaction schemes. A new reaction mechanism for the curing and the degradation of paint films is proposed. It is concluded that the microscopic approach to the elucidation of the degradation mechanism of oil paint films based on Raman spectroscopy is very useful for the improvement of oil painting techniques.

scholarly journals Fatty Acids Profile, Trans Isomers, and Lipid Quality Indices in Smoked and Unsmoked Cheeses and Cheese-Like Products

2019 ◽  
Vol 17 (1) ◽  
pp. 71 ◽  
Author(s):  
Beata Paszczyk ◽  
Magdalena Polak-Śliwińska ◽  
Joanna Łuczyńska
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Saturated Fatty Acids ◽  
Total Content ◽  
Monounsaturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Quality Indices ◽  
Chromatography Method ◽  
Lipid Quality ◽  
Chain Fatty Acids

The purpose of this study was to evaluate the fatty acid composition, including trans C18:1 and C18:2 isomers and the content of conjugated linoleic acid cis9trans11 C18:2 (CLA), in commercial smoked and unsmoked cheeses and cheese-like products available on the Polish market as well as to compare lipid quality indices in these products. The composition of fatty acids was determined with the gas chromatography method. The conducted study demonstrated that smoked and unsmoked cheeses as well as smoked and unsmoked cheese-like products were characterized by various contents of fatty acids and various lipid quality indices. The smoked and the unsmoked cheeses had significantly higher (p < 0.05) contents of saturated fatty acids (SFA), short-chain fatty acids (SCFA), and branched-chain fatty acids (BCFA) than the smoked and the unsmoked cheese-like products. The monounsaturated fatty acids (MUFA) and the polyunsaturated fatty acids (PUFA) contents were the highest in unsmoked cheese-like products (39.29 ± 1.49% and 9.13 ± 0.33%, respectively). In smoked and unsmoked cheeses, MUFA were above 24% and PUFA were above 2.4%. The total content of trans C18:1 isomers was significantly higher (p < 0.05) in the cheeses, but in the group of these isomers, trans10 + trans11 isomers were dominant. High levels of trans6–trans9 isomers (up to 2.92% of total fatty acid) were found in some of the samples of unsmoked cheese-like products, while their content in cheeses was lower. The lipid quality indices in cheeses and cheese-like products were varied. The smoked and the unsmoked cheeses were characterized by significantly higher (p < 0.05) values of the index of thrombogenicity (TI) and atherogenicity (AI) indices and significantly lower (p < 0.05) values of the hypocholesterolemic/hypercholesterolemic (HH) ratio.

Enzymic and chemical-extraction determinations of free fatty acids in serum compared.

1982 ◽  
Vol 28 (8) ◽  
pp. 1765-1768 ◽  
Author(s):  
P N Demacker ◽  
A G Hijmans ◽  
A P Jansen
Keyword(s):  
Fatty Acids ◽  
Free Fatty Acids ◽  
Extraction Procedure ◽  
Short Chain Fatty Acids ◽  
Chemical Extraction ◽  
Keto Acids ◽  
Test Kit ◽  
Hydrolysis Of ◽  
Chain Fatty Acids

Abstract We compared an enzymic test kit for determination of free fatty acids in serum (NEFA C-test, WAKO) with two modifications of a chemical extraction procedure, I (Clin. Chim. Acta 43: 317-320, 1973) and II (Clin. Chim. Acta 80: 327-332, 1977). All three procedures are specific for long- and medium-chain fatty acids. Short-chain fatty acids, some keto acids, and phospholipids did not interfere. Added fatty acid was quantitatively accounted for in all methods. Results obtained with the enzymic method and II did not differ significantly, whereas the results by I were about 10% lower. The concentration of NaCl in the copper reagent, but not the kind of solvent used to dissolve the standard, influenced the accuracy of the chemical methods. In the enzymic procedure, hydrolysis of triglycerides during incubation is unlikely to be the reason for too-high values. The precision of all three procedures is acceptable for use in clinical laboratories.

scholarly journals Understanding and optimizing Evolon® CR for varnish removal from oil paintings

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Lambert Baij ◽  
Chun Liu ◽  
Jesse Buijs ◽  
Alba Alvarez Martin ◽  
Dorien Westert ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Saturated Fatty Acids ◽  
Paint Film ◽  
Fold Increase ◽  
Mechanical Action ◽  
Laser Speckle ◽  
Dominant Factor ◽  
Solvent Exposure ◽  
Oil Paintings ◽  
Solvent Retention

AbstractEvolon$$^\circledR$$ ® CR is increasingly used in paintings conservation for varnish removal from oil paintings. Its key benefits over traditional cotton swabs are limiting solvent exposure and reducing mechanical action on the paint surface. However, this non-woven microfilament textile was not originally engineered for conservation use and little is known about its chemical stability towards organic solvents. Moreover, the physical processes of solvent loading and release by Evolon$$^\circledR$$ ® CR, as well as solvent retention inside paint after cleaning, have not been studied. These three topics were investigated using a multi-analytical approach, aiming for an improved understanding and optimized use of Evolon$$^\circledR$$ ® CR for varnish removal. Our results show that the tissue is generally chemically and physically stable to organic solvents when exposed on timescales that are typical in conservation practice. However, a pre-treatment step of Evolon$$^\circledR$$ ® CR is necessary to avoid the release of unwanted saturated fatty acids into the paint during varnish removal. We show that the primary mechanism of solvent uptake by the fibers is adsorption rather than absorption and that the dominant factor dictating the maximum solvent load is the volume of the voids between the fibers. Finally, solvent induced dynamics after application of solvent-loaded Evolon$$^\circledR$$ ® CR within the paint film was monitored using portable laser speckle imaging on model paints. A method to quantify solvent-retention in real-time was developed and revealed that the presence of varnish on paintings results in lower dynamics of solvents within the paint in comparison to unvarnished paint. Comparing various solvents, it was found that cleaning with acetone resulted in a roughly six-fold increase in dynamics compared to ethanol and isopropanol.

The effects of a series of saturated fatty acids in the diet on milk-fat secretion in the cow

1968 ◽  
Vol 35 (3) ◽  
pp. 361-370 ◽  
Author(s):  
W. Steele ◽  
J. H. Moore
Keyword(s):  
Fatty Acids ◽  
Stearic Acid ◽  
Palmitic Acid ◽  
Lauric Acid ◽  
Myristic Acid ◽  
Milk Fat ◽  
Volatile Fatty Acids ◽  
Saturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Fat Yield

SummaryThe effects of the isocaloric replacement of part of the dietary concentrate mixture by 5% lauric acid (99% pure) or by 10% of myristic (95% pure), palmitic (96% pure) or stearic (94% pure) on the yield and composition of milk fat was investigated in 2 feeding experiments with a total of 10 cows in mid-lactation. The concentrate mixtures were given with a high-roughage diet that supplied 9·1 or 7·7 kg hay/day in expts 1 and 2, respectively.In expt 1 the inclusion of myristic acid in the diet decreased the yields of milk and solids-not-fat (SNF), but increased the percentage of fat in the milk without altering the fat yield. When stearic or palmitic acid was included in the diet there was an increase in milk fat yield; palmitic acid caused the greater increase. In expt 2 the inclusion of lauric acid in the diet did not appear to affect the yields of milk or SNF but it caused large reductions in the percentage of fat in the milk and in the yield of fat.In expt 1 the inclusion of myristic acid increased the yields and percentages of 14:0, 14:1 and 16:1 in the milk fat and decreased the yields and percentages of the short-chain fatty acids (4:0–8:0), 16:0, 18:0 and 18:1. When palmitic acid was included in the diet there were increases in the yields and percentages of 16:0 and 16:1 in the milk fat and decreases in the yields and percentages of 10:0, 12:0, 14:0, 18:0 and 18:1. The inclusion of stearic acid in the diet increased the yields and percentages of 18:0 and 18:1 in the milk fat and decreased the yields and percentages of 12:0 and 16:0. In expt 2 the inclusion of lauric acid in the diet increased the yield and percentage of 12:0, and in 1 cow the content of 14:0 in the milk fat; there were reductions in the yields and percentages of all the other fatty acids in the milk fat. There was no evidence of any marked elongation of the carbon chains of 12:0 and 14:0 in the mammary gland to form 16:0 or 18:0.In expt 1 the incorporation of myristic acid in the diet decreased the concentration of total steam-volatile fatty acids in rumen liquor. The inclusion of either myristic, palmitic or stearic acid in the diet had little effect on the relative proportions of the individual volatile acids in the rumen liquor. In expt 2 the addition of lauric acid to the diet reduced the acetic acid:propionic acid ratio in the rumen liquor.

The Fatty Acid Composition of Vernix caseosa

1963 ◽  
Vol 16 (4) ◽  
pp. 679 ◽  
Author(s):  
DT Downing
Keyword(s):  
Fatty Acids ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Vernix Caseosa ◽  
Branched Chain ◽  
Hydrolysis Of

The fatty acids obtained on hydrolysis of sebum from newly-born babies contained approximately equal amounts of saturated and unsaturated fatty acids and 10% of α-hydroxyacids. Gas chromatographic examination showed that the saturated fatty acids (C12 to C30) contained 78% branched-chain and 22% normal compounds, while the unsaturated acids (C12 to C32) contained 15% branched and 85% normal compounds. The a-hydroxyacids (C10 to C26) contained 79% branched-chain and 21% normal components and had little if any unsaturation. The high proportion of branched-chain acids suggests that these are not likely to be exogenous.

scholarly journals Reaction kinetics in films. The hydrolysis of long-chain esters

1937 ◽  
Vol 163 (912) ◽  
pp. 70-89 ◽  
Keyword(s):  
Fatty Acids ◽  
Alkaline Hydrolysis ◽  
Molecular Orientation ◽  
Unsaturated Fatty Acids ◽  
Homogeneous Solution ◽  
Short Chain Fatty Acids ◽  
Steric Factor ◽  
Two Dimensional ◽  
Hydrolysis Of ◽  
Long Chain

The hydrolysis of the simple esters of the short-chain fatty acids in the bulk phase has been investigated under a variety of conditions (Moelwyn- Hughes 1933, pp. 87, 245). This has now been extended to the insoluble esters of the long-chain acids and alcohols. These are also of interest biologically, since the natural breakdown and resynthesis of fats are probably interfacial reactions. The work of Hughes and Rideal (1933) on the oxidation of the unsaturated fatty acids, and of Fosbinder and Rideal (1933) on the alkaline hydrolysis of γ -stearolactone, has shown that these interfacial or two-dimensional reactions may differ from those in homogeneous solution; chiefly in the possibility of controlling the true steric factor. In the present work also it has been found that the velocity of reaction between long-chain esters and alkali can be markedly altered by suitable changes in the molecular orientation. Such effects have been discussed in a previous communication (Alexander and Schulman 1937).

scholarly journals Short-Chain and Unsaturated Fatty Acids Increase Sequentially From the Lag Phase During Cold Growth of Bacillus cereus

2021 ◽  
Vol 12 ◽  
Author(s):  
Marina Français ◽  
Romain Bott ◽  
Claire Dargaignaratz ◽  
Christian Giniès ◽  
Frédéric Carlin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Stationary Phase ◽  
Bacillus Cereus ◽  
Cold Adaptation ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Cold Temperatures ◽  
Chain Fatty Acids

Fatty acids of two mesophilic and one psychrotrophic strains of the foodborne pathogen Bacillus cereus were analyzed by gas chromatography coupled to mass spectrometry during growth at cold (10 and 12°C) vs. optimal (30°C) temperatures and during the whole growth process (6–7 sampling times) from lag to stationary phase. In all these strains, a sequential change of fatty acids during cold growth was observed. Fatty acids were modified as soon as the end of lag, with an increase of the short-chain fatty acids (less than 15 carbons), particularly i13. These short-chain fatty acids then reached a maximum at the beginning of growth and eventually decreased to their initial level, suggesting their importance as a rapid cold adaptation mechanism for B. cereus. In a second step, an increase in Δ5,10 di-saturated fatty acids and in monounsaturated fatty acids in Δ5 position, at the expense of unsaturation in Δ10, started during exponential phase and continued until the end of stationary phase, suggesting a role in growth consolidation and survival at cold temperatures. Among these unsaturated fatty acids, those produced by unsaturation of n16 increased in the three strains, whereas other unsaturated fatty acids increased in some strains only. This study highlights the importance of kinetic analysis of fatty acids during cold adaptation.

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