Interpreting Mass Spectra Mass spectrum of 2,2-dimethylpropane (MW =72) 100 80 60 m/2=41 ◆m=57 40 m/2=29 20 0 10 20 40 60 80 100 120 140 m/z 2,2-dimethylpropane fragments so easily that no M*peak observed when electron-impact ionization is used "Soft"ionization methods can prevent fragmentation of molecular ion Mass spectrum of 2,2-dimethylpropane (MW = 72) ▪ 2,2-dimethylpropane fragments so easily that no M+ peak observed when electron-impact ionization is used ▪ “Soft” ionization methods can prevent fragmentation of molecular ion Interpreting Mass Spectra