ABSTRACT

Natural Abundance of Important Isotopes .................................................................................... 577 Rules for Determination of Molecular Formula ............................................................................ 578 Neutral Moieties Ejected from Substituted Benzene Ring Compounds ........................................ 580 Order of Fragmentation Initiated by the Presence of a Substituent on a Benzene Ring .............. 581 Chlorine-Bromine Combination Isotope Intensities ..................................................................... 582 Reference Compounds Under Electron Impact Conditions in Mass Spectrometry ...................... 584 Major Reference Masses in the Spectrum of Heptacosafluorotributylamine (Perfluorotributylamine) ................................................................................................................ 585 Common Fragmentation Patterns of Families of Organic Compounds ........................................ 586 Common Fragments Lost............................................................................................................... 589 Important Peaks in the Mass Spectra of Common Solvents.......................................................... 590 Reagent Gases for Chemical Ionization Mass Spectrometry ........................................................ 591 Proton Affinities of Some Simple Molecules ................................................................................ 593 Proton Affinities of Some Anions ................................................................................................. 594 Detection of Leaks in Mass Spectrometer Systems....................................................................... 595 Common Spurious Signals Observed in Mass Spectrometers....................................................... 597 Mass Resolution Required to Resolve Common Spectral Interferences Encountered in Inductively Coupled Plasma Mass Spectrometry (ICP-MS) ......................................................... 598

The following table lists the atomic masses and relative percentage concentrations of naturally occurring isotopes of importance in mass spectroscopy [1-5].