Categories

Separation and characterization of products from acidic methanolysis of plasmalogenic lipids by two-dimensional gas chromatography with online reduction

You are here:
  • Main
  • Metabolomics
  • Animal Science
  • Separation and characterization of products from acidic methanolysis of plasmalogenic lipids by two-dimensional gas chromatography with online reduction
< All Topics

Authors: Pierluigi Delmonte, Xabier Belaunzaran, Clark D. Ridge, Noelia Aldai, John K.G. Kramer

Abstract

The complexity of determining the composition of animal tissue lipids is greatly increased by the presence of plasmalogens in which the alkyl chain is linked to glycerol by an enol ether bond instead of being esterified. Acidic methanolysis of animal tissue lipids provides the simultaneous scission of acyl and alkenyl ether moieties, but the complexity of the products of reaction poses a great challenge in their gas chromatographic analysis. Two-dimensional gas chromatography with online reduction (GC-OR × GC) provided the resolution of all components contained in acid methanolyzed animal lipids, taking advantage of the selective hydrogenation of alkenyl ether methanolysis products prior to the second-dimension separation (2D). In this study, we also studied the chemical transformations occurring during the acidic methanolysis of animal lipids and the subsequent gas chromatographic analysis. In particular, we observed that using methanolysis reagents contaminated with water resulted in the undesired formation of fatty aldehydes, and we made recommendations on how to avoid these side reactions using proper methanolysis conditions. Products of acidic methanolysis were studied by GC-OR × GC, GC-MS, NMR spectroscopy, and GC with flame ionization detection (GC-FID). We defined the GC-FID elution order of animal lipid acidic methanolysis products using 100 m × 0.25 mm 100% bis(cyanopropyl)siloxane columns and two different set of elution conditions: isothermal elution at 180°C, and a temperature program optimized for dairy fats. A simple procedure for isolating dimethyl acetals (DMA) prior to GC analysis is also described.

Read full study: https://www.sciencedirect.com/science/article/abs/pii/S0021967320301424?via%3Dihub

Previous Article Mineral oil saturated hydrocarbons (MOSH) in female Fischer 344 rats; accumulation of wax components; implications for risk assessment