COMPARISON OF ENERGY-RESOLVED LOW-ENERGY CAD OF STABLE AND ISOMERIZING IONS IN AN FT-ICR AND IN OTHER TANDEM MASS SPECTROMETERS

Energy-resolved collisionally-activated dissociation (CAD) was carried out in a dual-cell FT-ICR for the molecular ions of n-propanol, hexaf luoropropene, three ionized organophosphorus eaters, and four C3H7O+ i somers. The results are compared to data measured earlier in triple qu adrupole, BQQ, BEQQ, and quadrupole ion trap mass spectrometers. In ge neral, low-energy CAD spectra generated in a dual-cell FT-ICR are comp arable to those measured using other types of tandem mass spectrometer s when roughly similar activation conditions are used (number of activ ating collisions, laboratory ion kinetic energy), and this agreement i s best at low collision energies. However, ions which undergo slow iso merization prior to collisional activation are an exception. These ion s can yield CAD product distributions in an FT-ICR and other ion traps that are significantly different from those obtained in mass spectrom eters which sample ions with shorter lifetimes.