The molecular ion peak is weak or absent. When observable, will be a good indication of the presence of an amine (nitrogen rule).
An important fragmentation pattern involves cleavage of the bond to the a-carbon as shown in figure 47. The largest alkyl group is lost preferentially.
Figure 47. a-cleavage.
Loss of hydrogen radical, is quite common in amines as shown in figure 48.
Figure 48. Loss of hydrogen radical.
The complete mass spectrum for diethyl amine is given in figure 49, which illustrates most of these points.
Figure 49. Mass spectrum for diethyl amine.
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