A COMBINED MAGNETIC SECTOR-TIME-OF-FLIGHT MASS-SPECTROMETER FOR STRUCTURAL DETERMINATION STUDIES BY TANDEM MASS-SPECTROMETRY

A combined magnetic sector-time-of-flight instrument has been construc ted and used with both continuous (liquid secondary ion mass spectrome try and electrospray ionization) and pulsed (matrix-assisted laser des orption/ionization) ion sources. The design includes provision for bot h low- and high-energy gas collision induced decompositions and orthog onal acceleration of the product ions into the time-of-flight mass ana lyser. Tandem mass spectra may be acquired for singly and multiply cha rged precursor ions and reliable mass measurements are easily obtained . Product-ion mass spectra are quite reproducible regardless of any in stability in the precursor ion beam intensity.