ENHANCED MASS RESOLUTION IN MATRIX-ASSISTED LASER DESORPTION/IONIZATION LINEAR TIME-OF-FLIGHT MASS-SPECTROMETRY

The limits of performance of a linear time-of-flight mass spectrometer using matrix-assisted laser desorption/ionization have been tested. Effects of the pressure in the vacuum system and the sampling rate of the digital oscilloscopes on mass resolution have been investigated. Spectra recorded at different pressures and at sampling rates of 100 MS s(-1), 400 MS s(-1) and 1 GS s(-1) are compared. A mass resolving power m/Delta m (full width at half maximum) of 900 to 2400 has been achieved for a selection of peptides and proteins within a mass range from 800 to 6000 Da.