Fellgett Revisited:\nOn the Nature of Noise in Two-Dimensional\nMass Spectrometry

Two-dimensional mass spectrometry (2DMS) is a truly data-independent\nacquisition technique used in the analysis of complex mixtures; however,\nthe nature of the noise within these spectra is not well understood.\nIn this work, 2DMS is tested for conformity with the Fellgett principle:\n(signal/noise) ∝ √ (no. of data points). Since 2DMS\nfunctions through the modulation of ions through a fragmentation region\nacross many scans, the individual scans are considered data points\nin this experiment. Random noise was shown to be prevalent as the\nmain source of noise in this experiment with minor systematic noise.\nThis means that the minimum size for a 2DMS spectrum that displays\na target fragment ion can be determined using a fast-2D equation detailed\nherein. The effects of existing denoising algorithms were also found\nto change the relationship between the signal-to-noise ratio and the\nscan numbers to be of a quasi-linear nature rather than the square\nroot trend observed before denoising.