OzMALDI: A Gas-Phase, In-Source Ozonolysis Reaction for Efficient Double-Bond Assignment in Mass Spectrometry Imaging...

Area of Science:

• Lipidomics
• Analytical Chemistry
• Mass Spectrometry Imaging

Background:

• Lipid diversity presents analytical challenges, hindering understanding of biological functions.
• Determining double-bond positions in lipid isomers is crucial but difficult for mass spectrometry imaging (MSI).
• Existing ozonolysis methods for double-bond analysis require extended analysis or sample preparation times.

Purpose of the Study:

• To introduce an innovative inline ozonolysis method for mass spectrometry imaging (MSI).
• To enable rapid and accurate determination of double-bond positions in unsaturated lipids.
• To overcome the limitations of prior techniques in analyzing lipid isomers.

Main Methods:

• Development of OzMALDI: an ozonolysis technique integrated into the matrix-assisted laser desorption-ionization (MALDI) source.
• Simultaneous ozonide production from all unsaturated lipids within the MALDI source.
• Analysis using Orbitrap mass spectrometry for high mass resolution and MSI capabilities.

Main Results:

• OzMALDI determines double-bond positions without increasing analysis time.
• The method effectively analyzes multiple double-bond positions, particularly in polyunsaturated fatty acids.
• Successful application to rat brain and engineered plant seed samples, revealing novel biological information.

Conclusions:

• OzMALDI is a powerful new tool for lipid isomer analysis in MSI.
• The technique enhances the understanding of lipid structure-function relationships in biological systems.
• OzMALDI facilitates the discovery of new biological insights from complex lipid samples.