Nitrogen containing organic compound when fused with sodium metal forms:

Covalent bonds hold nitrogen $\left({\mathrm{N}}_2\right)$ to the organic molecule. When covalently bound nitrogen is fused with sodium metal $\left(\mathrm{Na}\right)$), it transforms into ionic sodium cyanide $\left(\mathrm{NaCN}\right)$), which may be recovered by boiling the fused mass with distilled water and is employed for nitrogen detection.