Fourier transform ion cyclotron resonance mass spectrometry in a high homogeneity 25 Tesla resistive magnet

Many performance parameters of Fourier transform ion cyclotron resonance (F T-ICR) mass spectrometry improve dramatically with increasing magnetic fiel d. Our prior results from a 20 tesla resistive magnet showed that performan ce was limited by the large spatial inhomogeneity in spite of the high fiel d. In this paper, we compare matrix-assisted laser desorption/ionization (M ALDI) mass spectra at the same magnetic field for two resistive magnets wit h different field spatial homogeneity. In addition, we report MALDI spectra at 25 tesla-the highest magnetic field for FT-ICR to date. The first broad band FT-ICR mass spectrum [poly(ethylene glycol) 2000] from a resistive mag net is accurately fitted by the standard ICR mass calibration function. (C) 1999 American Society for Mass Spectrometry.