Advanced mass calibration and visualization for FT-ICR mass spectrometry imaging

Area of Science:

• Analytical Chemistry
• Biotechnology
• Molecular Imaging

Background:

• Mass spectrometry imaging (MSI) using Fourier transform ion cyclotron resonance (FT-ICR) offers high mass accuracy and resolving power.
• FT-ICR MSI enables confident identification of small molecules and lipids directly from biological tissue sections.
• Existing FT-ICR MSI methods face challenges in data calibration and high-resolution visualization.

Purpose of the Study:

• To investigate and improve calibration strategies for FT-ICR MS imaging.
• To develop a novel visualization method for high-resolution FT-ICR MS imaging data.
• To enhance the identification and analysis of molecular information in biological tissues.

Main Methods:

• Development and application of advanced calibration techniques for FT-ICR MS imaging.
• Implementation of total and relative ion abundance correction methods to mitigate ion fluctuations.
• Introduction of the "Mosaic Datacube" for high-resolution visualization of the entire mass range.

Main Results:

• Achieved sub-parts-per-million (ppm) mass accuracy across an entire tissue section.
• Reduced root-mean-square error to 0.158 ppm for 16,764 peaks through ion abundance correction.
• Demonstrated the "Mosaic Datacube"'s ability to resolve spectral features at a 0.001 Da bin width, not visible at lower resolutions.

Conclusions:

• The developed calibration strategies significantly enhance the mass accuracy of FT-ICR MS imaging.
• The "Mosaic Datacube" provides a powerful new tool for visualizing and analyzing high-resolution FT-ICR MS imaging data.
• These advancements facilitate more confident and detailed molecular identification in biological tissues.