Salvation of acylium fragment ions in electrospray ionization quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry

In electrospray ionization (ESI) quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry, certain fragment ions (e.g. acyl ium ions) generated either during the ion transportation process tin the so urce interface region) or in the ion trap are found to undergo ion-molecule reactions with ESI solvent molecules (water, acetonitrile and aliphatic al cohols) to form adduct species. These unexpected solvated fragment ions sev erely complicate the interpretation of mass spectrometic data. High-resolut ion accurate mass measurements are important in establishing the elemental compositions of these adduct species and preventing erroneous data interpre tation. Copyright (C) 2001 John Wiley & Sons, Ltd.