Version 2 2024-01-02, 15:06Version 2 2024-01-02, 15:06
Version 1 2023-12-21, 17:04Version 1 2023-12-21, 17:04
journal contribution
posted on 2024-01-02, 15:06authored byAndrej Grgic, Konstantin O. Nagornov, Anton N. Kozhinov, Jesse A. Michael, Ian G.M. Anthony, Yury O. Tsybin, Ron M.A. Heeren, Shane R. Ellis
Matrix-assisted
laser
desorption ionization (MALDI) mass
spectrometry
imaging (MSI) is a powerful analytical tool that enables molecular
sample analysis while simultaneously providing the spatial context
of hundreds or even thousands of analytes. However, because of the
lack of a separation step prior to ionization and the immense diversity
of biomolecules, such as lipids, including numerous isobaric species,
the coupling of ultrahigh mass resolution (UHR) with MSI presents
one way in which this complexity can be resolved at the spectrum level.
Until now, UHR MSI platforms have been restricted to Fourier transform
ion cyclotron resonance (FT-ICR) mass spectrometers. Here, we demonstrate
the capabilities of an Orbitrap-based UHR MSI platform to reach over
1,000,000 mass resolution in a lipid mass range (600–950 Da).
Externally coupling the Orbitrap Q Exactive HF with the high-performance
data acquisition system FTMS Booster X2 provided access to the unreduced
data in the form of full-profile absorption-mode FT mass spectra.
In addition, it allowed us to increase the time-domain transient length
from 0.5 to 10 s, providing improvement in the mass resolution, signal-to-noise
ratio, and mass accuracy. The resulting UHR performance generates
high-quality MALDI MSI images and simplifies the identification of
lipids. Collectively, these improvements resulted in a 1.5-fold increase
in annotations, demonstrating the advantages of this UHR imaging platform
for spatial lipidomics using MALDI-MSI.