The determination of N-nitrosamines in food
Introduction N-nitrosamines are formed in food as a result of natural chemical interactions, but mainly through food processing activity. Most are potent carcinogens and their determination is therefore of considerable importance. They exist in various chemical forms and have been measured by colorimetric and spectroscopic methods following gas or liquid chromatography or as a total N-nitroso group by measurement of chemically released nitric oxide. Objectives To provide an overview of the available methods for the analysis of N-nitrosamines in food that includes recently developments. Methods The literature was reviewed from the discovery of the N-nitrosamine problem and the introduction on the N-nitroso-specific detector. Results The evaluation shows that analytical detection methods for volatile N-nitrosamines in food have changed little since the introduction on the N-nitroso-specific detector and that research into the occurrence and formation of both non-volatile N-nitrosamines and the apparent total N-nitroso content (ATNC) have declined. Methods for measuring the apparent total N-nitroso content have not been improved significantly in recent years. Conclusion Modern sample extraction techniques and mass spectrometric methods for the volatile N-nitrosamines have been applied more extensively to water analysis and offer a good opportunity to improve the determination of these carcinogens in food and make the analysis more widely available. Developments in liquid chromatography-mass spectrometry should provide an avenue for renewed interest in non-volatile N-nitrosamines, and could help with the identification of novel compounds whose presence is suggested by the high apparent total N-nitroso content of some foods.