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.