Mass spectrometry differentiation of sciadonic acid isomers and estimate of long-chain polyunsaturated fatty acid intake from fresh and processed duck eggs

Journal of Food Composition and Analysis, Journal Year: 2025, Volume and Issue: unknown, P. 107253 - 107253

Published: Jan. 1, 2025

Language: Английский

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A New, Validated GC-PICI-MS Method for the Quantification of 32 Lipid Fatty Acids via Base-Catalyzed Transmethylation and the Isotope-Coded Derivatization of Internal Standards

Metabolites, Journal Year: 2025, Volume and Issue: 15(2), P. 104 - 104

Published: Feb. 7, 2025

Background: Fatty acids (FAs) represent a ubiquitous class of nonpolar alkyl carboxylate metabolites with diverse biological functions. Nutrition, metabolism, and endogenous exogenous stress influence the overall FA metabolic status transport via bloodstream. FAs esterified in lipids are particular interest, as they promising biomarkers pathological diseases nutritional status. Methods: Here, we report validated gas chromatographic-mass spectrometric (GC-MS) method for quantitative analysis 32 exclusively bound lipids. The developed sample preparation protocol comprises three steps using only 5 µL human serum Folch extraction, sodium methoxide-catalyzed transesterification tert-butyl methyl ether, re-extraction isooctane prior to GC-MS positive ion chemical ionization (PICI) selected monitoring (SIM). Results: base-catalyzed transmethylation step was studied 14 lipid classes found be efficient under mild conditions all major but not free FAs, amides, or sphingolipids. To minimize matrix effects instrument bias, internal fatty acid trideuteromethyl esters (D3-FAME) standards were prepared through isotope-coded derivatization D3-labeled methylchloroformate/methanol medium mixed each transmethylated extract assay. according FDA guidelines evaluated by analyzing NIST SRM 2378 Serum 1 sera from healthy donors. Conclusions: measured values consistent reference data 2378, demonstrate application potential described general novel complementary tool lipidomics, well membrane dry blood spots red cells.

Language: Английский

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Highly Sensitive Chemical Ionization Tandem Mass Spectrometry Method for the Identification of Unsaturated Fatty Acids Derivatized by Dimethyl Disulfide

Journal of the American Society for Mass Spectrometry, Journal Year: 2025, Volume and Issue: unknown

Published: April 21, 2025

Derivatization of unsaturated fatty acids with dimethyl disulfide (DMDS) and analysis by electron ionization mass spectrometry (EIMS) represent a convenient offline method for the identification double bond positions. However, presence overlapping spectra from multiple compounds poses significant challenges spectral interpretation library matching, leading to ambiguous molecular information low sensitivity. To overcome issue, we developed novel chemical (CI) tandem involving pre-derivatization DMDS collisional activation [M+47]+ ions generated in ion source. The provides better specificity targeted does not require any customized devices. Further, reaction monitoring (MRM) version was designed screening all diagnostic possible positional isomers, which significantly boosts Compared traditional EIMS method, new exhibits lower limit detection (LLOD) that is one-tenth or lower. Employing unusual isomer 18:2(5Z,8Z) co-analyzed 18:2(9Z,12Z), 20:2(7Z,10Z) characterized human sebum. Additionally, 16:2(9Z,12Z), an odd-chain omega-3 polyunsaturated acid (21:5n-3) polymethylene-interrupted i.e. 22:2(7Z,13Z) 22:2(7Z,15Z) were identified seafood related products. Our can be readily applied GC instrument equipped MS expected facilitate discovery unknown food, clinical, environmental sources.

Language: Английский

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Unusual polyunsaturated fatty acids in edible marine worms identified by covalent adduct chemical ionization mass spectrometry

Food Chemistry, Journal Year: 2024, Volume and Issue: 463, P. 141287 - 141287

Published: Sept. 13, 2024

Language: Английский

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