IMPROVING THE RESOLUTION OF MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME-OF-FLIGHT MASS-SPECTROMETRY BY EXPLOITING THE CORRELATION BETWEEN ION POSITION AND VELOCITY

By taking into account the correlation between the positions and velocities of desorbed ions in the source region of a time-of-flight mass spectrometer and by including this relationship in the equations used to determine space-focusing conditions, it is predicted that matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectral resolution can be improved significantly. Experiments involving MALDI of two proteins, insulin and ubiquitin, demonstrate the validity of this concept. Adduct formation does not limit mass spectral resolution in these two cases.