The term nitrosamine describes a class of compounds having the chemical structure of a nitroso group bonded to an amine (R1N(-R2)-N=O). The chemical reaction of Amines and Nitrogen Lead to the formation of nitrosamines. These compounds are potent genotoxic agents and are even Carcinogens. FDA has identified nitrosamine impurities that theoretically could be present in drugs. We provide a range of these impurities and stable isotopes which are synthesized at high purity to help identify the presence of nitrosamines in drugs and finished products.