The formation of N-nitrosamines, many of which have been shown to be carcinogenic in experimental animals, is a relatively facile chemical reaction. Very good analytical methods exist for volatile nitrosamines and a number of surveys have shown that certain foods, particularly cured meats and direct fire dried foods, can contain ppb quantities of volatile nitrosamines. Our knowledge of the nonvolatile nitrosamine content of foods is lacking primarily because adequate analytical methodology for nonvolatile nitrosamines in foods has not been developed. The purpose of this proposal is to develop reliable analytical methodology for nonvolatile nitrosamines in foods. Previous work in our laboratory has lead to the synthesis of several groups of nonvolatile nitrosamines. These include N-nitroso dipeptides N terminal in proline, N-nitroso derivatives of secondary amine malt alkaloids, and N-nitroso Amadori compounds. Using these groups of compounds as standards, we will develop separation and detection procedures based on GC-TEA or HPLC-TEA. The nonvolatile nitrosamines will be derivatized to volatile compounds for GC-TEA analysis. Procedures for efficient extraction of the nonvolatile nitrosamines from samples of food and procedures to clean up the extracts will be developed. Walter's procedure for total N-nitroso compounds will be challenged with a wide range of N-nitroso compounds. The purpose will be to determine whether Walter's procedure responds quantitatively on a molar basis to N-nitroso compounds under food analysis conditions. Using the procedures developed for specific groups of nonvolatile nitrosamines and Walter's procedure for total N-nitroso compounds if appropriate, we will survey a large number of foods for nonvolatile nitrosamines. Procedures will be developed to confirm the identity of specific nonvolatile nitrosamines by mass spectrometry.
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|Ahmad, M U; Libbey, L M; Scanlan, R A (1987) Identification of minor nitrosation products of the alkaloid gramine by mass spectrometry. Food Chem Toxicol 25:867-70|
|Ahmad, M U; Libbey, L M; Barbour, J F et al. (1985) Isolation and characterization of products from the nitrosation of the alkaloid gramine. Food Chem Toxicol 23:841-7|