Mass Spectrometry Imaging Techniques: Non-Ambient and Ambient Ionization Approaches

Area of Science:

• Analytical Chemistry
• Biotechnology
• Materials Science

Background:

• Mass spectrometry imaging (MSI) is a powerful technique for analyzing molecular distributions on sample surfaces.
• It provides high spatial resolution and concurrent information on multiple compounds.
• MSI has gained significant attention across various scientific fields over the past decades.

Purpose of the Study:

• To review sampling protocols, working principles, and applications of MSI techniques.
• To compare non-ambient and ambient ionization MSI methods.
• To assess the suitability of MSI for biological sample analysis, especially in tissue diagnostics.

Main Methods:

• Description of non-ambient MSI techniques: Secondary Ionization Mass Spectrometry (SIMS) and Matrix-Assisted Laser Desorption/Ionization (MALDI).
• Description of ambient MSI techniques: Desorption Electrospray Ionization (DESI), Laser Ablation Electrospray Ionization (LAESI), Probe Electrospray Ionization (PESI), Desorption Atmospheric Pressure Photoionization (DAPPI), and Femtosecond Laser Desorption Ionization (FLDI).
• Comparative analysis of advantages and disadvantages of ambient and non-ambient MSI.

Main Results:

• MSI enables real-time acquisition of molecular information from sample surfaces.
• Both ambient and non-ambient MSI techniques offer distinct advantages for molecular imaging.
• The choice of technique depends on the specific application, particularly for biological samples.

Conclusions:

• MSI is a revolutionary technique with broad applicability in scientific research.
• Ambient ionization techniques offer enhanced versatility for analyzing diverse samples, including biological tissues.
• Future prospects involve addressing challenges to further advance MSI capabilities in fields like tissue diagnostics.