9.4 Tesla Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometers (Bruker BioAPEX-94e) have been installed at the Division of Ion Physics, Uppsala University, and at the Department of Chemistry, University of Warwick. The BioAPEX-94e FT-ICR instrument is built around a high-field, superconducting magnet and a platform with easily interchangeable ion sources [matrix-assisted laser desorption/ionisation (MALDI), secondary ion mass spectrometry (SIMS), electrospray ionisation (ESI) and electron impact/chemical ionisation (EI/CI)]. In this paper a technical description of the instrument is given. Outstanding performance characteristics are demonstrated, notably clear resolution of C₅₉N⁺ and C₅₈¹³C²⁺ (mass difference 3.65 mDa) and mass measurement accuracy at the low ppm level. A wide range of applications in Warwick and Uppsala is described, demonstrating the versatility and high performance of the instrument.

Keywords: FT-ICR, ESI, nanospray, MALDI, SIMS, EI/CI, sustained off-resonance irradiation / collision-induced dissociation (SORI/CID), electron capture dissociation (ECD), multipole-storage assisted dissociation (MSAD), quadrupolar excitation axialisation (QEA), infrared multiphoton dissociation (IRMPD)