Illustrated Glossary of Organic Chemistry

Molecular ion: In mass spectrometry a molecule of the analyte that has been ionized by electron loss, but not fragmented.


 Ionization
Fragmentation

 CH3+
 +
 H+
Analyte
Molecular ion
Fragments




m/z
  
m/z
  
Relative abundance (%)
  
Assignment
18
< 0.5
Molecular ion (M+2)
17
1.1
Molecular ion (M+1)
16
100.0
Molecular ion (M); base peak
15
85.0
Fragment (M - H)
14
9.2
Fragment (M - 2H)
13
3.0
Fragment (M - 3H)
12
1.0
Fragment (M - 4H)
Mass spectrum of methane.