Enhancement of Lipid Signals in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry with Ammonium Fluoride as a Matrix Additive

Abstract

Lipids are essential macromolecules that play a crucial role in numerous biological events. Lipids are structurally diverse which allows them to fulfill multiple functional roles. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a powerful tool to understand the spatial localization of lipids within biological systems. Herein, we report the use of ammonium fluoride (NH 4 F) as a comatrix additive to enhance lipid detection in biological samples, with a signal increase of up to 200%. Emphasis was placed on anionic lipid enhancement with negative polarity measurements, with some preliminary work on cationic lipids detailed. We observed lipid signal enhancement of [M−H] − ions with the addition of NH 4 F additive attributed to a proton transfer reaction in several different lipid classes. Overall, our study demonstrates that the use of the NH 4 F comatrix additive substantially improves sensitivity for lipid detection in a MALDI system and is capable of being applied to a variety of different applications.

Quantitative mass spectrometry imaging: therapeutics & biomolecules

“…45 Numerous MSI studies have focused on increasing both the sensitivity and specificity of measurements for biomolecules. 46–49 Distinguishing how a disease state or therapeutic intervention impacts biomolecule expression and localization can give us further insight into both the pharmacokinetics 50 and pharmacodynamics. 51…”