Nitrogen Rule

Definition

It is a rule that conveys how organic compounds that contain; oxygen, hydrogen, carbon, nitrogen, phosphorus, sulfur, and halogens have 1 odd nominal mass that shows odd numbers of nitrogen atoms. It can even show an even nominal mass that has an even number of nitrogen.

Explanation

In mass spectrometry, an odd molecular weight indicates an odd number of nitrogen atoms in the compound, while an even molecular weight indicates either an even number of nitrogen atoms or the absence
of nitrogen.