Influence of Ion-Ion Coulomb Interactions on FT-ICR Mass Spectra at a High Magnetic Field: A Many-Particle Simulation Using a Special-Purpose Computer

摘要

A previously developed simulation program code for FT-ICR mass spectra has been improved and accelerated using a special-purpose computer for many-body problems. As a result, the simulation speed has become 10 times faster. Thus it has been possible to compute longer ICR transient signals and simulate the FT-ICR mass spectra with higher resolving power. The accelerated computing configuration was applied to simulation for the influence of ion-ion Coulomb interactions on FT-ICR mass spectra especially at a high magnetic field. At a magnetic field of 5 T, the peak coalescence problem was investigated and at high ion density the peak coalescence appeared for closely spaced m/z ion mixtures of m/z 100.00 and 100.05; however, the complete phase locking of the two ion clouds, which is expected to occur under the conditions at a low magnetic field and high ion density, was not observed. Furthermore, ion loss ratio was estimated for m/z 100.00 ions as a function of initial ion population and it was found that the peak intensity is proportional to the initially trapped ion population at low ion density; however, the linearity is not maintained at high ion density.