Fourier transform (FT)-artifacts and power-function resolution filter in Fourier transform mass spectrometry

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Computational Chemistry

Background:

• Mass spectrometry peak picking algorithms struggle with signal wiggles (side lobes), leading to inaccurate mass lists.
• This issue is exacerbated by longer transients in modern high-memory digitizers, affecting both MS and MS/MS spectra.

Purpose of the Study:

• To investigate the origin of Fourier transform (FT) artifacts, specifically sinc side lobes, in FT-ICR-MS.
• To develop and validate a novel method for identifying and removing these FT-artifacts.

Main Methods:

• Experimental analysis using a solariX FTMS mass spectrometer with varying transient lengths (512k to 8M data points).
• Fourier transformation of time-domain transients to analyze frequency spectra and sinc wiggle development.
• MATLAB simulations to investigate the origins of FT-artifacts.

Main Results:

• A new filter was developed to distinguish FT-artifacts (sinc side lobes) from true signals based on Full Width at Half Maximum (FWHM).
• The filter establishes a confidence limit for signal resolution, enabling accurate identification.
• The filter is effective across a broad mass range (100-1200 amu).

Conclusions:

• The study elucidated the cause of FT-artifacts from transient truncations in FT-ICR-MS.
• A novel, automated filter successfully identifies and eliminates FT-artifacts without reliance on intensity thresholds or magnetic field strength.
• This solution enhances the accuracy of mass spectral data analysis, particularly with long transients.