Correction of Time-of-Flight Shifted Polymeric Molecular Weight Distributions in Matrix-Assisted Laser Desorption/Ionization Fourier Transform Mass Spectrometry

摘要

Molecular weight distributions on an external injection matrix-assisted laser desorption/ionization Fourier trans- form mass spectrometer are subject to time-of-flight distortions as different ion velocities are probed with varied delay times between ionization and trapping(i.e., the trapping time). This phenomenon is used to advan- tage to reject low-mass matrix ions which would otherwise saturate the trapped ion cell: however, for accurate determination of molecular weight distributions of com- plex samples like polymeric systems, several mass spectra must be acquired at a series of different trapping times to compensate for this distortion.