Improved gas chromatography-flame ionization detector analytical method for the analysis of epoxy fatty acids

Mubiru, Edward; Shrestha, Kshitij; Papastergiadis, Antonios; Meulenaer, Bruno De

doi:10.1016/j.chroma.2013.10.025

Cited by 38 publications

(36 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Basic methods such as thin layer chromatography continue to be used for separating different classes of lipids (70,110,135). Gas chromatography (GC) is a popular separation method for modified fatty acids and improved methods continue to be reported, for example, in separation of epoxy fatty acids from hydroxy and un-modified fatty acids (83). Coupling GC to MS provides additional structural information based on the fragmentation profile of the analytes.…”

Section: Approaches To Phospholipid Analysismentioning

confidence: 99%

Oxidative Lipidomics Coming of Age: Advances in Analysis of Oxidized Phospholipids in Physiology and Pathology

Spickett

Pitt

2015

Antioxidants & Redox Signaling

View full text Add to dashboard Cite

Significance: Oxidized phospholipids are now well recognized as markers of biological oxidative stress and bioactive molecules with both pro-inflammatory and anti-inflammatory effects. While analytical methods continue to be developed for studies of generic lipid oxidation, mass spectrometry (MS) has underpinned the advances in knowledge of specific oxidized phospholipids by allowing their identification and characterization, and it is responsible for the expansion of oxidative lipidomics. Recent Advances: Studies of oxidized phospholipids in biological samples, from both animal models and clinical samples, have been facilitated by the recent improvements in MS, especially targeted routines that depend on the fragmentation pattern of the parent molecular ion and improved resolution and mass accuracy.

show abstract

Section: Approaches To Phospholipid Analysismentioning

confidence: 99%

Oxidative Lipidomics Coming of Age: Advances in Analysis of Oxidized Phospholipids in Physiology and Pathology

Spickett

Pitt

2015

Antioxidants & Redox Signaling

View full text Add to dashboard Cite

show abstract

“…Further identified were cis ‐11,12‐epoxyoctadecenoic acid and trans ‐11,12‐epoxyoctadecenoic acid (derived from vaccenic acid). The six possible monoepoxy acids derived from linolenic acid in principle also can be quantified , but complete identification of all six peaks was not undertaken in our laboratory until now.…”

Section: Resultsmentioning

confidence: 99%

“…Methyl‐ cis ‐10,11‐epoxyheptadecanoate was synthesized from 10(Z)‐heptadecenoic acid methyl ester and 3‐chloroperbenzoic acid as described by Mubiru et al . The final product was dissolved in iso‐octane.…”

Section: Methodsmentioning

confidence: 99%

“…Identification of different isomers of epoxy‐, keto‐, and hydroxy fatty acids, which are partially not completely resolved even by modern capillary GC on polar phases, by GC‐MS and GC‐FTIR was elucidated by Berdeaux and coworkers . Mubiru et al determined epoxy fatty acids in 37 fresh oils from the Belgian market in a range of 0.03–2 g/kg. Epoxy fatty acid content did not correlate to the peroxide value.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Epoxy fatty acids in used frying fats and oils, edible oils and chocolate and their formation in oils during heating

Brühl

Weißhaar

Matthäus

2015

Euro J Lipid Sci & Tech

View full text Add to dashboard Cite

The occurrence of monoepoxy fatty acids in used frying oils and in other common foods has been determined. Monoepoxy fatty acids with trans-9,10-and cis-9,10-epoxystearate and trans-12,13-, trans-9,10-, cis-12,13-and cis-9,10-epoxyoctadecenoate were found at average levels of 3.7 g/kg in used frying fats and oils, but also at about 2 g/kg in the fat fraction of chocolate. They were also detected in pumpkin seed, sweet almond, groundnut, sunflower, and olive oils at average levels of 3.4, 1.7, 1.4, 1.0, and 0.2 g/kg, respectively. Their formation during heating at 175°C was observed for sunflower, rapeseed, soybean, and linseed oil and compared with the increase of polar compounds and polymerized triacylglycerols as other important quality indicators for frying oils. During heating for 16 h, the level of monoepoxy fatty acids increased to about 30, 18, 8, and 4 g/kg for olive, sunflower, linseed, and rapeseed oils, respectively. The influence of the heating temperature was surveyed for refined soybean oil at 160, 170, 180, and 200°C. Heating of two sets of five different refined and virgin rapeseed oils revealed a significant lower formation of monoepoxy fatty acids for refined oils at a median level of 4.6 g/kg compared to 7.7 g/kg for virgin oils.Practical applications: Determination of fatty acid methyl esters is one of the most common analyses for the evaluation of oils and fats. The assessment of the monoepoxy fatty acids as part of these analyses can provide a first indication about used frying fats and oils, which reached the end of their applicability. The formation of monoepoxy fatty acids is affected by the fatty acid composition of the oil, the heating temperature, and the production of the oil. Therefore, frying oils may contain varying amounts of monoepoxy fatty acids at the maximum limit for polar compounds and polymerized triacylglycerols as used in the official food control. However, all used frying oils investigated by the official food control showing more than 7 g/kg of monoepoxy fatty acids had to be rejected due to the limits exceeded for polar compounds and polymerized triacylglycerols. Therefore, this limit of 7 g/kg monoepoxy fatty acids level is proposed as a level for screening the usability of used frying fats and oils.

show abstract

“…The silica column was prepared by filling a Pasteur pipette with 1 g of activated Si gel. A three‐step SPE approach was used for extraction of hydroxy FAME . The non‐polar fraction was eluted using 15 mL of 98:2 hexane: ethyl ether.…”

Section: Methodsmentioning

confidence: 99%

GC‐MS Characterization of Hydroxy Fatty Acids Generated From Lipid Oxidation in Vegetable Oils

Xia¹,

Budge²

2017

Euro J Lipid Sci & Tech

View full text Add to dashboard Cite

Lipid oxidation has long been described as following a radical chain reaction mechanism, where hydrogen abstraction is considered the preferred pathway. Hydroxy compounds are, in theory, major products formed from hydrogen abstraction but their presence is rarely monitored. In this study, a GC‐MS technique to characterize hydroxy fatty acids (FA) formed during the oxidation of sunflower and canola oils is described. First, hydroxy FA in oxidized oils are methylated and isolated from non‐oxygenated structures using solid phase extraction (SPE). Then they are converted into their trimethylsilyl (TMS) derivatives using a N,O‐bis (trimethylsilyl) trifluoroacetamide (BSTFA)‐pyridine method and identified by their electron ionization (EI) and positive chemical ionization (PCI) spectra. Separation of most isomeric hydroxy FA with very similar structures is accomplished using a DB‐23 capillary column with (50%‐cyanopropyl)‐methylpolysiloxane phase. The fragmentation patterns of the TMS derivatives are discussed in detail and several easily applicable rules for spectral interpretations are presented. The major hydroxy FA arising from oxidation of sunflower and canola oils are allylic and conjugated structures, specifically 8‐, 9‐, 10‐, and 11‐hydroxyoctadecenoic acid (OH‐C18:1) and 9‐ and 13‐hydroxyoctadecadienoic acid (OH‐C18:2). Practical Applications: Unsaturated hydroxy FA are potential indicators of hydrogen abstraction reactions by FA alkoxyl radicals during lipid oxidation. A prerequisite for the quantification of these hydroxy FA is knowledge of their structures. In this work a GC‐MS method, coupled with SPE and TMS derivatization, to characterize the hydroxy FA derived from oxidation of vegetable oils, which will enable future quantifications of these compounds is employed. In addition, the use of EI and PCI spectra provided clear strategies to interpret mass spectra for both saturated and unsaturated hydroxy FA. The fragmentation patterns in EI and PCI presented in this paper will benefit future studies on identification or quantification of both saturated and unsaturated hydroxy FA in other lipid samples. Hydroxy fatty acids in oils are methylated and isolated using solid phase extraction. They are converted into their trimethylsilyl (TMS) derivatives, which enabled identification by the electron ionization and positive chemical ionization spectra. Here, the fragmentation patterns of the TMS derivatives are discussed in detail and several easily applicable rules for spectral interpretations are presented.

show abstract

Improved gas chromatography-flame ionization detector analytical method for the analysis of epoxy fatty acids

Cited by 38 publications

References 26 publications

Oxidative Lipidomics Coming of Age: Advances in Analysis of Oxidized Phospholipids in Physiology and Pathology

Oxidative Lipidomics Coming of Age: Advances in Analysis of Oxidized Phospholipids in Physiology and Pathology

Epoxy fatty acids in used frying fats and oils, edible oils and chocolate and their formation in oils during heating

GC‐MS Characterization of Hydroxy Fatty Acids Generated From Lipid Oxidation in Vegetable Oils

Contact Info

Product

Resources

About