Iterative correction of suppressed peptide profiles from FTMS measurements

Abstract

Analysis of peptide profiles from a Liquid Chromatography Fourier Transform Mass Spectrometry (LC/FTMS) measurement reveals a non-linear distortion in intensity. Investigation of the measured CVi /C12 ratios comparing with theoretical ones shows that the non-linearity can be attributed to low intensity signal suppression of low abundance peptide peaks. We find that the suppression is homogenous for different isotopes of identical peptides but non-homogenous for different peptides. We developed an iterative correction algorithm that corrects the intensity distortions for peptides with relatively high abundance. This algorithm can be applied in a wide range of applications using FTMS.