Determination of double bond positions in fatty acids with conjugated double bonds

1978 ◽  
Vol 5 (7) ◽  
pp. 439-443 ◽  
Author(s):  
G. Janssen ◽  
G. Parmentier
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Double Bonds

scholarly journals Gas Chromatographic Determination of Fatty Acids in Oils with Regard to the Assessment of Fire Hazard

2017 ◽  
Vol 25 (40) ◽  
pp. 73-81 ◽  
Author(s):  
Alica Bartošová ◽  
Tomáš Štefko
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Spontaneous Combustion ◽  
Unsaturated Fatty Acids ◽  
Fire Hazard ◽  
Accurate Determination ◽  
Coconut Oil ◽  
Double Bonds ◽  
Self Heating

Abstract The aim of the paper was to study and research the application of processing gas chromatographic method for the rapid and accurate determination of the composition of different types of oils, such as substances with the possibility of an adverse event spontaneous combustion or self-heating. Tendency to spontaneous combustion is chemically characterized mainly by the amount of unsaturated fatty acids, which have one or more double bonds in their molecule. Vegetable oils essentially consist of the following fatty acids: palmitic, stearic, oleic, linoleic, and linoleic. For the needs of assessment, the fire hazard must be known, in which the double bond is present, as well as their number in a molecule. As an analytical method, GCMS was used for determination of oils content. Three types of oil were used - rapeseed, sunflower, and coconut oil. Owing to the occurrence of linoleic acid C18:2 (49.8 wt.%) and oleic acid C18:1 (43.3 wt.%) with double bonds, sunflower oil is the most prone to self-heating. The coconut and rapeseed oils contain double bond FAME in lesser amount, and their propensity to self-heating is relatively low.

scholarly journals Phenolation of vegetable oils

2011 ◽  
Vol 76 (4) ◽  
pp. 591-606 ◽  
Author(s):  
Mihail Ionescu ◽  
Zoran Petrovic
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Double Bond ◽  
Vegetable Oils ◽  
Raw Materials ◽  
Complex Mixture ◽  
Double Bonds ◽  
Triflic Acid ◽  
Model Compounds ◽  
Phenol Alkylation

Novel bio-based compounds containing phenols suitable for the synthesis of polyurethanes were prepared. The direct alkylation of phenols with different vegetable oils in the presence of superacids (HBF4, triflic acid) as catalysts was studied. The reaction kinetics was followed by monitoring the decrease of the double bond content (iodine value) with time. In order to understand the mechanism of the reaction, phenol was alkylated with model compounds. The model compounds containing one internal double bond were 9-octadecene and methyl oleate and those with three double bonds were triolein and high oleic safflower oil (82% oleic acid). It was shown that the best structures for phenol alkylation are fatty acids with only one double bond (oleic acid). Fatty acids with two double bonds (linoleic acid) and three double bonds (linolenic acid) lead to polymerized oils by a Diels Alder reaction, and to a lesser extent to phenol alkylated products. The reaction product of direct alkylation of phenol with vegetable oils is a complex mixture of phenol alkylated with polymerized oil (30-60%), phenyl esters formed by transesterification of phenol with triglyceride ester bonds (<10 %) and unreacted oil (30%). The phenolated vegetable oils are new aromatic-aliphatic bio-based raw materials suitable for the preparation of polyols (by propoxylation, ethoxylation, Mannich reactions) for the preparation of polyurethanes, as intermediates for phenolic resins or as bio-based antioxidants.

Structural Homogeneity in Unsaturated Fatty Acids of Marine Lipids. A Review

1964 ◽  
Vol 21 (2) ◽  
pp. 247-254 ◽  
Author(s):  
R. G. Ackman
Keyword(s):  
Fatty Acids ◽  
Double Bond ◽  
Polyunsaturated Fatty Acids ◽  
Chain Length ◽  
Unsaturated Fatty Acids ◽  
Analytical Data ◽  
Double Bonds ◽  
Marine Origin ◽  
Methyl Group ◽  
Marine Lipids

Consideration of recent analytical data supports the conclusion that the longer-chain polyunsaturated fatty acids of marine origin are all structurally homogeneous in that the double bonds are cis, the double bonds methylene interrupted, and that, with the exception of the C16 chain length, the ultimate double bond will normally be three, six or nine carbon atoms removed from the terminal methyl group.

scholarly journals Positional determination of the carbon–carbon double bonds in unsaturated fatty acids mediated by solvent plasmatization using LC–MS

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shigeo Takashima ◽  
Kayoko Toyoshi ◽  
Takuhei Yamamoto ◽  
Nobuyuki Shimozawa
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Double Bonds

THE SIGNIFICANCE OF AN ABSORPTION BAND AT 968 CM.−1 IN THE INFRARED SPECTRUM OF METHYL ISOLINOLEATE

1949 ◽  
Vol 27b (7) ◽  
pp. 610-615 ◽  
Author(s):  
H. W. Lemon ◽  
C. K. Cross
Keyword(s):  
Fatty Acids ◽  
Absorption Spectrum ◽  
Double Bond ◽  
Absorption Band ◽  
Linseed Oil ◽  
Infrared Absorption Spectrum ◽  
Methyl Esters ◽  
Trans Configuration ◽  
Double Bonds ◽  
Identical Band

The infrared absorption spectrum of methyl isolinoleate, separated from the methyl esters of hydrogenated linseed oil fatty acids, has a well defined absorption band with maximum absorption at about 968 cm.−1 As an identical band was found in the spectra of fatty acids or esters after isomerization with selenium, it is attributed to the presence of double bonds with a trans-configuration. It was found that the same band was present in the spectra of samples taken during hydrogenation of oils, and that its intensity increased to a maximum, then decreased as hydrogenation proceeded. It is concluded that hydrogenation is accompanied by a cis-to-trans change in some of the double bonds of the fatty acids, and that methyl isolinoleate has at least one double bond with a trans-configuration.

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