The nitrogen containing organic compound, when heated with \(CuO\) in a atmosphere of \(CO _2\), yields free \(N _2\) in addition to \(CO _2\) and \(H _2 O\).

\(C _{ x } H _{ y } N _{ z }+\left(2 x +\frac{ y }{2}\right) CuO \rightarrow x CO _2+\frac{ y }{2} H _2 O +\frac{ z }{2} N _2+\left(2 x +\frac{ y }{2}\right) Cu\)

Traces of nitrogen oxides formed, if any, are reduced to nitrogen by passing the gaseous mixture over heated copper gauze.