Gas chromatographic behavior of fatty acid derivatives for mass spectrometry on low‐polarity capillary columns

Dubois, Nolwenn; Barnathan, Gilles; Gouygou, Jean‐Paul; Bergé, Jean‐Pascal

doi:10.1002/ejlt.200800148

Cited by 15 publications

(4 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A rather mild method was used for the synthesis of DMOX derivatives of FA (Svetashev 2011). It is known that ECL values of methyl esters, pyrrolidides, and DMOX derivatives of FA are similar on low-polarity GC columns (Dubois et al 2009). The comparison of GC chromatograms of N-acyl derivatives and methyl esters of 18:5n-3 showed that both pyrrolidine and DMOX derivatives chromatograms had one major peak.…”

Section: Fame Analysismentioning

confidence: 99%

Isomerization of octadecapentaenoic acid (18:5n‐3) in algal lipid samples under derivatization for GC and GC‐MS analysis

Svetashev

Imbs

2014

Journal of Phycology

View full text Add to dashboard Cite

During gas chromatography (GC) analysis of fatty acid (FA) composition of the dinoflagellate Gymnodinium kowalevskii, we found unex-pectedly low and irreproducible content of all-cis-3,6,9,12,15-octadecapentaenoic acid (18:5n-3), which is an important chemotaxonomic marker of several classes of microalgae. We compared chromatographic behavior of 18:5n-3 methyl ester and other GC derivatives obtained using different conventional methods of derivatization. The use of methods based on saponification or base-catalyzed transesterification resulted in a mixture of double-bond positional isomers of 18:5. On a SUPELCOWAX 10 column, the equivalent chain length (ECL) value for authentic 18:5n-3 methyl ester was 20.22, whereas the main component after base-catalyzed methylation had ECL 20.88. Attempts to prepare N-acyl pyrrolidides or 4,4-dimethyloxazoline (DMOX) derivatives of 18:5n-3 also gave inadequate results. These derivatives also showed a main peak corresponding to isomerized 18:5. Mass spectra for both DMOX and pyrrolidide derivatives of this compound showed the base peak at m/z 139, probably corresponding to 2,6,9,12,15-18:5 acid. Of all methods tested for methylation, only derivatization with 5% HCl or 1% sulphuric acid in methanol gave satisfactory results. Therefore, GC or GC-mass spectrometry analyses of algal lipids containing 18:5n-3 may be inaccurate when base-catalyzed methods of FA derivatization are applied. The best and simplest way to avoid incorrect GC results is to use standard acid-catalyzed methylation.

show abstract

Section: Fame Analysismentioning

confidence: 99%

Isomerization of octadecapentaenoic acid (18:5n‐3) in algal lipid samples under derivatization for GC and GC‐MS analysis

Svetashev

Imbs

2014

Journal of Phycology

View full text Add to dashboard Cite

show abstract

“…However, the double‐bond positions cannot be determined by comparing the similarity between the mass spectrum and the library data. Conventionally, the derivatives such as pyrrolidide or picolinyl ester are used in determining the double‐bond positions of unsaturated fatty acid with GC/MS (Åkesson‐Nilsson & Wesén, ; Andersson, Heimermann, & Holman, ; Andersson & Holman, ; Christie, , ; Christie, Brechany, & Holman, ; Christie & Han, ; Destaillats & Angers, ; Dobson & Christie, ; Dubois, Barnathan, Gouygou, & Bergé, ; Dubois, Barthomeuf, & Bergé, ; Wretensjö, Svensson, & Christie, ). With the aforementioned method, the double‐bond positions can be determined by the difference of fragment ions in which cleavage occurs between the double‐bond carbons is 12u, and the difference of fragment ions in which cleavage occurs between the single‐bond carbons is 14u.…”

Section: Introductionmentioning

confidence: 99%

Preparation of Dimethyl Disulfide Adducts from the Mono‐Trans Octadecadienoic Acid Methyl Esters

Shibamoto

Murata

et al. 2018

Lipids

View full text Add to dashboard Cite

The dimethyl disulfide (DMDS) adduct method is one of the more effective methods for determining double bond positions of dienoic acid. The DMDS method can be simply used to obtain the characteristic ions in which cleavage occurs between the methylthio group-added double-bond carbons as can be seen in the mass spectrum obtained using gas chromatography/electron ionization-mass spectrometry. In the case of the methylene-interrupted di-cis type and di-trans type dienoic acid, the DMDS addition reaction only occurs at one double-bond position, and cannot occur at the remaining double-bond position due to steric hindrance. As a result, two types of adducts are produced in the addition reaction. However, in the case of the methylene-interrupted mono-trans (mono-cis) type dienoic acid, the DMDS addition reaction only occurs at the cis-double bond. As a result, one type of adduct is produced in the addition reaction. In this report, we investigate the cause of the reaction selectivity by focusing on the addition reaction time.

show abstract

“…Some reported analysis procedures convert triglycerides into picolinyl esters, -acyl pyrrolidines, and DMOX derivatives (4,4-dimethyloxazoline) to enable detection by mass spectrometry. These derivatives are separated using a lowpolarity column because of its high thermal stability [18]. Gas chromatography-mass spectrometry (GC-MS) has been widely used for the structural analysis of FAs.…”

Section: Introductionmentioning

confidence: 99%

Rapid Analysis Procedures for Triglycerides and Fatty Acids as Pentyl and Phenethyl Esters for the Detection of Butter Adulteration Using Chromatographic Techniques

DellaGreca

Ruffo

Andolfi

et al. 2017

Journal of Food Quality

View full text Add to dashboard Cite

This paper presents the development of three methods for quality control, fraud detection, and authentication of butter fat and other oils/fats using chromatographic techniques, with one method for triglycerides and two methods for fatty acids (FAs). The procedure for the analysis of triglycerides requires only dissolution of the sample in n-hexane and gas chromatography (GC) analysis using a capillary column. The second method is based on the transesterification of triglycerides as pentyl esters in a single-step reaction using sodium pentanoate in pentanol. The reaction proceeds at room temperature and is similar to the potassium hydroxide-catalysed transesterification of triglycerides with methanol and even more similar to the sodium methoxide method and sodium butanoate method. The advantage of using pentyl esters includes reducing the volatility of short-chain FAs, and substantial recoveries were obtained compared with methyl ester analysis. The third method involves the transesterification of triglycerides in fat through reaction with 2-phenylethanol in a single step; 2-phenylethanol possesses a chromophore, and the phenethyl esters formed are analysed by high-performance liquid chromatography (HPLC) with UV detection.

show abstract

Gas chromatographic behavior of fatty acid derivatives for mass spectrometry on low‐polarity capillary columns

Cited by 15 publications

References 27 publications

Isomerization of octadecapentaenoic acid (18:5n‐3) in algal lipid samples under derivatization for GC and GC‐MS analysis

Isomerization of octadecapentaenoic acid (18:5n‐3) in algal lipid samples under derivatization for GC and GC‐MS analysis

Preparation of Dimethyl Disulfide Adducts from the Mono‐Trans Octadecadienoic Acid Methyl Esters

Rapid Analysis Procedures for Triglycerides and Fatty Acids as Pentyl and Phenethyl Esters for the Detection of Butter Adulteration Using Chromatographic Techniques

Contact Info

Product

Resources

About