Oilseeds. Extraction of oil and preparation of methyl esters of triglyceride fatty acids for analysis by gas chromatography (Rapid method)

Abstract A study was made to compare the rapid method reported by Allen with the tentative method of the American Oil Chemists’ Society for the determination of isolated (unconjugated) trans isomers of unsaturated fatty acids. The rapid method was found to be less accurate. The accuracy of the rapid method can be improved by using an oil or methyl ester matrix with the same composition as the sample matrix for the determination of K-and f-values used for calculation of per cent trans isomers. Results obtained with both methods for methyl esters were more accurate than results for vegetable oils. An analysis of variance was performed to compare the methods.

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Comparison of Two Derivatization Methods for the Analysis of Fatty Acids andTransFatty Acids in Bakery Products Using Gas Chromatography

The Scientific World JOURNAL ◽

10.1155/2014/906407 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Jumat Salimon ◽

Talal A. Omar ◽

Nadia Salih

Keyword(s):

Fatty Acids ◽

Gas Chromatography ◽

Methyl Esters ◽

Correlation Coefficients ◽

Bakery Products ◽

Trimethylsilyl Diazomethane ◽

Acid Catalyzed ◽

High Level ◽

Level Of Agreement

Two different procedures for the methylation of fatty acids (FAs) andtransfatty acids (TFAs) in food fats were compared using gas chromatography (GC-FID). The base-catalyzed followed by an acid-catalyzed method (KOCH3/HCl) and the base-catalyzed followed by (trimethylsilyl)diazomethane (TMS–DM) method were used to prepare FA methyl esters (FAMEs) from lipids extracted from food products. In general, both methods were suitable for the determination ofcis/transFAs. The correlation coefficients (r) between the methods were relatively small (ranging from 0.86 to 0.99) and had a high level of agreement for the most abundant FAs. The significant differences (P=0.05) can be observed for unsaturated FAs (UFAs), specifically for TFAs. The results from the KOCH3/HCl method showed the lowest recovery values (%R) and higher variation (from 84% to 112%), especially for UFAs. The TMS-DM method had higherRvalues, less variation (from 90% to 106%), and more balance between variation and %RSD values in intraday and interday measurements (less than 4% and 6%, resp.) than the KOCH3/HCl method, except for C12:0, C14:0, and C18:0. Nevertheless, the KOCH3/HCl method required shorter time and was less expensive than the TMS-DM method which is more convenient for an accurate and thorough analysis of richcis/transUFA samples.

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Direct ultrasound-assisted methylation of fatty acids in serum for free fatty acid determinations

Canadian Journal of Chemistry ◽

10.1139/v10-077 ◽

2010 ◽

Vol 88 (9) ◽

pp. 898-905 ◽

Cited By ~ 8

Author(s):

Liyan Liu ◽

Ying Li ◽

Rennan Feng ◽

Changhao Sun

Keyword(s):

Mass Spectrometry ◽

Fatty Acids ◽

Gas Chromatography ◽

Fatty Acid ◽

Fatty Acid Methyl Esters ◽

Methyl Esters ◽

Ultrasonic Waves ◽

Acid Methyl ◽

Ultrasound Assisted

A method for simultaneous determination of 16 free fatty acids (FFAs) in serum is described. The method involves conversion of FFAs to fatty acid methyl esters (FAMEs) using the heat of ultrasonic waves followed by gas chromatography and mass spectrometry (GC–MS) analysis. Optimum levels of the variables affecting the yield of FAMEs were investigated. The results indicate that the optimal levels are 55 °C, 60 W, 10% H2SO4/CH3OH, and 50 min. Recoveries ranged from 85.32% to 112.11%, with a detection limit ranging from 0.03 to 0.08 μg mL–1. The linearity, using the linear correlation coefficient, was higher than 0.9914.

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Performance of GC-MS analysis for differentiation of various types of flour by creating dendrogram of liposoluble extract

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq120209030v ◽

2012 ◽

Vol 18 (4-1) ◽

pp. 555-561 ◽

Cited By ~ 8

Author(s):

Djura Vujic ◽

Marijana Acanski ◽

Marija Bodroza-Solarov ◽

Nikola Hristov ◽

Milica Krunic

Keyword(s):

Mass Spectrometry ◽

Fatty Acids ◽

Cluster Analysis ◽

Gas Chromatography ◽

Methyl Oleate ◽

Methyl Palmitate ◽

Methyl Esters ◽

Fatty Acids Composition ◽

Different Types ◽

Small Grains

Gas chromatography with mass spectrometry was used for performing a qualitative analysis of liposoluble flour extract made of different types of small grains (bread wheat, barley and triticale). The results show that the dominant methyl-esters of fatty acids composition is same for all samples, but the percentage of their representation in various types of small grains is different. Transesterification reagent was TMSH (Trimethylsulfonium hydroxide, 0.2M in methanol). With transesterification reaction fatty acids from acilglycerol esterifyed to methyl-esters. In all extract analyzed methyl linoleate predominated, followed by methyl palmitate, methyl oleate and methyl stearate in decreasing order. The following tests cluster analysis was used for the comparison of the liposoluble flour extract different types of small grains.

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Homogenity of oil and sugar components of flour amaranth investigated by GC-MS

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq131104007p ◽

2015 ◽

Vol 21 (1-1) ◽

pp. 71-76

Author(s):

Djordje Psodorov ◽

Marijana Acanski ◽

Djura Vujic ◽

Jovana Brkljaca ◽

Dragan Psodorov

Keyword(s):

Mass Spectrometry ◽

Fatty Acids ◽

Gas Chromatography ◽

Methyl Esters ◽

Soluble Sugars ◽

Soluble Carbohydrates ◽

Three Samples ◽

Hexane Extracts ◽

Ethanol Extracts ◽

Ethanol Ethanol

Gas chromatography with mass spectrometry (GC-MS) was used for performing a qualitative analysis of liposoluble and hydrosoluble flour extracts of three genotypes of Amaranthus sp. All three samples were first defatted with hexane. Hexane extracts were used for the analysis of fatty acids of lipid components. TMSH (Trimethylsulfonium hydroxide, 0.2M in methanol) was used as the transesterification reagent. With transesterification reaction, fatty acids were esterified from acilglycerol to methyl-esters. Defatted flour samples were dried in the air and then extracted with ethanol. Ethanol extracts were used for the analysis of soluble carbohydrates. TMSI (trimethylsilylimidazole) was used as a reagent for the derivatization of carbohydrates into trimethylsilylethers. The results show that the dominant methyl-esters of fatty acids are very similar in all the three samples. Such a similarity was not detected in the analysis of soluble sugars. The following test cluster analysis was used for the comparison of liposoluble and hydrosoluble flour extracts of three genotypes of Amaranthus sp.

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A comparison of structural–functional equation models to identify fatty acids on three common gas chromatography columns

Analytical Methods ◽

10.1039/c7ay02456h ◽

2018 ◽

Vol 10 (15) ◽

pp. 1747-1759 ◽

Cited By ~ 1

Author(s):

A. T. L. Wotherspoon ◽

K. L. Reeves ◽

J. Crawford

Keyword(s):

Fatty Acids ◽

Functional Equation ◽

Gas Chromatography ◽

Fatty Acid Methyl Esters ◽

Functional Relationship ◽

Structural Information ◽

Methyl Esters ◽

Acid Methyl ◽

Chromatography Columns ◽

Gas Chromatography Columns

Reported herein is a series of new structural–functional relationship equations which provide relevant structural information of unknown fatty acid methyl esters (double-bonds, chain-length, and omega-bond position) based upon temperature induced shifts in equivalent chain length's (ECLs).

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