Absorption mode Fourier transform mass spectrometry with no baseline correction using a novel asymmetric apodization...

Area of Science:

• Analytical Chemistry
• Spectroscopy

Background:

• Absorption mode Fourier transform ion cyclotron resonance (FTICR) mass spectrometry offers superior spectral resolution, signal-to-noise ratio, and mass accuracy.
• Existing methods for generating absorption mode spectra introduce baseline deviation due to Fourier transform artifacts, complicating spectral interpretation.
• Current baseline correction techniques are computationally demanding, slow, and often unreliable.

Purpose of the Study:

• To develop a novel method for producing absorption mode FTICR mass spectra without baseline deviation.
• To maintain the inherent benefits of absorption mode spectra, including high resolution and accuracy.
• To offer a more efficient and reliable alternative to existing baseline correction methods.

Main Methods:

• Implementation of a 'full' apodization function, replacing conventional Hann or half Hann functions.
• The 'full' apodization function's maximum position is user-adjustable (F parameter) relative to the transient length.
• Application of the apodization prior to zero-padding and Fourier transformation.

Main Results:

• The proposed apodization method yields absorption mode spectra free from baseline deviation, eliminating the need for post-processing correction.
• Adjusting the F parameter allows for a tunable trade-off between spectral resolving power and signal-to-noise ratio.
• This method is particularly advantageous for spectra with significant amplitude fluctuations during transient recording.

Conclusions:

• Utilizing a 'full' apodization function, potentially asymmetric, before Fourier transformation effectively generates absorption mode FTICR mass spectra without baseline deviation.
• Elimination of the post-processing baseline correction step offers a significant performance enhancement for FTICR mass spectrometry.
• The new method simplifies spectral analysis and improves data quality in FTICR mass spectrometry.