nitrosamiine

Nitrosamines are a class of organic compounds characterized by the presence of a nitroso group bonded to a nitrogen atom of an amine, giving the general structure R2N–N(=O)–R'. They are commonly referred to as N-nitrosamines, with notable examples such as N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA).

Formation and occurrence: Nitrosamines form when nitrosating agents, such as nitrous acid or nitrites in acidic conditions, react with amines. This reaction can occur in industrial settings, during the manufacture or storage of pharmaceuticals, or in food processing and cooking processes that involve nitrite curing agents or high heat. Endogenous formation can also occur in the human stomach under certain conditions.

Properties and examples: Nitrosamines vary in volatility and polarity. NDMA and NDEA are among the most studied due to their persistence and toxicity. Many nitrosamines are formed as trace impurities in consumer products, such as drugs, cosmetics, processed foods, and tobacco smoke.

Health effects and regulation: Nitrosamines are of concern because they are carcinogenic in animals and are regarded as probable or possible carcinogens to humans by international agencies. Regulatory bodies impose limits on nitrosamine levels in drinking water, foods, pharmaceuticals, and consumer products, and have initiated risk-reduction programs to minimize exposure and control sources of contamination.

Detection and mitigation: Analytical methods such as gas chromatography–mass spectrometry and liquid chromatography–mass spectrometry are used to detect nitrosamines at trace levels. Mitigation strategies include reducing nitrite exposure, controlling pH to limit nitrosation, using alternative synthesis routes, and implementing purification and adsorption techniques to remove nitrosamines from products.