Scan-Centric, Frequency-Based Method for Characterizing Peaks from Direct Injection Fourier Transform Mass...

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Computational Chemistry

Background:

• Direct injection multi-scan Fourier transform mass spectrometry (FTMS) is crucial for analyzing complex samples.
• Accurate peak characterization is essential for reliable molecular identification.

Purpose of the Study:

• To develop a novel, scan-centric method for robust peak characterization in FTMS.
• To improve the accuracy of identifying low abundance isotopologues and their relative intensities.

Main Methods:

• Utilizes frequency values from raw m/z point spacing in spectral scans.
• Employs intensity-independent noise removal and scan-level data normalization.
• Calculates peak- and scan-specific statistics with quality control steps.

Main Results:

• Achieves a better fit of relative intensity to natural abundance probabilities for low abundance isotopologues.
• Robustly derives peak centers, intensities, and intensity ratios with scan-level variances.
• Provides cross-scan characterized peaks suitable for downstream analysis.

Conclusions:

• The novel scan-centric method enhances the characterization of peaks in complex FTMS data.
• Improved peak characterization supports accurate molecular formula enumeration, particularly for low abundance species.
• This method is compatible with existing tools like Small Molecule Isotope Resolved Formula Enumeration (SMIRFE).