[Effect of various blockers of nitrite and nitrogen oxide on the formation of nitrosamines].

The effects of galacturonic, gallic, acetylneuraminic acid, ascorbate, cysteine, glutathion and imidazole on the formation of dimethylnitrosamine and diethylnitrosamine was studied in a simple aqueous medium with four different nitrite contents (50, 100, 500 and 1 000 ppm) and the two amines, compared with control samples. The nitrosamines were determined by the TELLING method (confirmed by photolysis). The results observed were compared with the laws of fixing nitrite in the form of nitrogen oxide, studied previously. For sarcosin and imidazole, the fixing takes into account the phenomena observed. The other substances lead to a conclusion that there are two stages in the process: 1) fixing of the nitrite to a greater or lesser degree in the form of a nitrogen oxide complex, 2) direct effect on the nitrosation reaction which is catalysed or slowed down. The discussion based on the literature, concludes that the final nitrosation reaction give rise to free radicals, even in an aqueous medium.