... Time-of-Flight Mass Spectrometry, Michael Guilhaus, Journal of mass Spectrometry, Vol 30, 1519-32 (1995) -10- Mass Spectrometry @ the Organic Chemistry Department Ions of very high mass- to-charge ... millimass units (mmu), unified atomic mass units (u), or parts-per-million (ppm) The parts-per-million error is defined as: ppm = measured mass theoretical mass 10 theoretical mass -13- (16) Mass ... “Advanced Mass Spectrometry , Pergamon Press, Oxford (1983) I.Howe, D.H Williams & R.D Bowen, Mass Spectrometry Principles and Applications”, McGraw-Hill Inc., New york (1981) R.I Reed, Mass Spectrometry ,...