Ambient Metabolic Profiling and Imaging of Biological Samples with Ultrahigh Molecular Resolution Using Laser Ablation Electrospray Ionization 21 Tesla FTICR Mass Spectrometry

Mass
spectrometry (MS) is an indispensable analytical tool to capture
the array of metabolites within complex biological systems. However,
conventional MS-based metabolomic workflows require extensive sample
processing and separation resulting in limited throughput and potential
alteration of the native molecular states in these systems. Ambient
ionization methods, capable of sampling directly from tissues, circumvent
some of these issues but require high-performance MS to resolve the
molecular complexity within these samples. Here, we demonstrate a
unique combination of laser ablation electrospray ionization (LAESI)
coupled with a 21 tesla Fourier transform ion cyclotron resonance
(21T-FTICR) for direct MS analysis and imaging applications. This
analytical platform provides isotopic fine structure information directly
from biological tissues, enabling the rapid assignment of molecular
formulas and delivering a higher degree of confidence for molecular
identification.