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DOE OSTI · 2543179

OzMALDI: A Gas-Phase, In-Source Ozonolysis Reaction for Efficient Double-Bond Assignment in Mass Spectrometry Imaging with Matrix-Assisted Laser Desorption/Ionization

Rensner, Josiah J. [Iowa State University, Ames, IA (United States)]·Kim, Hyojin [University of Nebraska, Lincoln, NE (United States)]·Park, Kiyoul [University of Nebraska, Lincoln, NE (United States)]·Cahoon, Edgar B. [University of Nebraska, Lincoln, NE (United States)]·Lee, Young Jin [Iowa State University, Ames, IA (United States)] (ORCID:0000000225335371)
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Abstract

Lipids make up an important class of biomolecules with diverse structures and varied chemical functions. This diversity is a major challenge in chemical analysis and limits our understanding of biological functions and regulation. A major way lipid isomers differ is by double-bond (db) position, and analyzing db-isomers is especially challenging for mass spectrometry imaging (MSI). Ozonolysis can be used to determine the dbposition and has been paired with MSI before. However, previous techniques require increased analysis time to allow for gas-phase reactions within an ion trap or ion mobility cell or additional sample preparation time to allow for offline ozonation. Here, we introduce a new ozonolysis method inside the matrix-assisted laser desorption-ionization (MALDI) source, termed OzMALDI, that simultaneously produces ozonides from all unsaturated lipids. This allows us to determine db-positions without adding additional reaction time while maintaining the high mass resolution provided by Orbitrap MS. This new technique is especially effective at determining multiple db-positions in lipids containing polyunsaturated fatty acids, which is a limitation of many previous techniques. OzMALDI-MSI was applied to the analysis of rat brain and genetically engineered Camelina and soybean seed samples, demonstrating the utility of this method and uncovering novel biological information.

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRYCentral nervous systemIonsLipidsMass spectrometryWater treatment

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Rensner, Josiah J. [Iowa State University, Ames, IA (United States)], Kim, Hyojin [University of Nebraska, Lincoln, NE (United States)], Park, Kiyoul [University of Nebraska, Lincoln, NE (United States)], Cahoon, Edgar B. [University of Nebraska, Lincoln, NE (United States)], Lee, Young Jin [Iowa State University, Ames, IA (United States)] (ORCID:0000000225335371). 2025-03-31. OzMALDI: A Gas-Phase, In-Source Ozonolysis Reaction for Efficient Double-Bond Assignment in Mass Spectrometry Imaging with Matrix-Assisted Laser Desorption/Ionization. https://doi.org/10.1021/acs.analchem.5c00284

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