Liquid chromatography high-resolution mass spectrometry for fatty acid profiling

Area of Science:

• Plant biology
• Lipidomics
• Analytical chemistry

Background:

• Fatty acid quantification is vital for understanding plant lipid biosynthesis.
• Traditional methods like gas chromatography (GC) require sample derivatization and chemical standards.
• Limitations exist in sensitivity and scope of current fatty acid analysis techniques.

Purpose of the Study:

• To develop and validate an alternative method for fatty acid quantification using liquid chromatography-mass spectrometry (LC-MS).
• To compare the efficacy of LC-MS with established gas chromatography-flame ionization detection (GC-FID) methods.
• To explore the potential of LC-MS for discovering novel fatty acids.

Main Methods:

• Lipid hydrolysis followed by LC-MS analysis.
• Peak annotation using authentic standards and (13)C isotope-labeled Arabidopsis.
• Comparative analysis of Arabidopsis thaliana mutants (FAD6, FAD7) using both LC-MS and GC-FID.
• Untargeted LC-MS analysis of fatty acids in two diatom species.

Main Results:

• A simplified hydrolysis procedure enables direct fatty acid quantification via LC-MS.
• LC-MS and GC-FID methods provide comparable results for known fatty acids.
• LC-MS demonstrates superior sensitivity and selectivity, allowing for broader fatty acid coverage.
• Novel fatty acids were identified in diatom species using the LC-MS approach.

Conclusions:

• The developed LC-MS method provides a sensitive and selective alternative for fatty acid quantification.
• This approach facilitates the identification of a wider range of fatty acids, including novel ones.
• The method is applicable to various organisms, including plants and diatoms, advancing lipidomic research.