Advantages of High Magnetic Field for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

It is well-known that mass resolving power in Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) can increase linearly with increasing applied magnetic field induction, B. Here, we show that eight other FTICR primary performance parameters theoretically also increase linearly (quadrupolar axialization efficiency, data acquisition speed), quadratically (upper mass limit, maximum ion kinetic energy, maximum number of trapped ions, maximum ion trapping duration, two-dimensional FTICR mass resolving power), or inverse-quadratically (peak coalescence tendency) with increasing B. The origin of (and conditions for) the magnetic field dependence of each of these parameters are presented and discussed. These fundamental advantages lead to corollary improvement in other FTICR performance parameters: e.g. signal-to-noise ratio, dynamic range, mass accuracy, ion remeasurement efficiency and mass selectivity for MS/MS. Finally, we note that these various advantages may be exploited in combination, so as to produce even higher enhancement in a particular parameter: e.g. signal-to-noise ratio can improve by more than a factor of B2 if mass resolving power is fixed at the same value as at lower magnetic field.