Detection of a new nitrosamine, N-nitroso-N-methylaniline, and other nitrosamines in Icelandic smoked mutton

Varying levels (1-48 ppb) of N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (NPYR), and a previously undetected nitrosamine, N-nitroso-N-methylaniline (NMA), were detected in Icelandic smoked mutton. Traces (0.6-2.4 ppb) of N-nitrosothiazolidine (NThZ) and low levels (56-475 ppb) of N-nitrosothiazolidine-4-carboxylic acid (NTCA), the two N-nitroso compounds commonly detected in smoked meats, were also present in such products. Evidence presented suggests that NMA in the meat is produced by the interaction of nitrite and smoke generated by burning sheep dung, the traditional source of fuel used for smoking such products. Nitrosation of laboratory-generated sheep dung smoke produced NMA, as well as NDMA and NPYR. The identity of NDMA, NPYR, and NMA was confirmed by mass spectrometry. It is suggested that the formation of all of the above nitrosamines in Icelandic smoked mutton can be minimized by changing or modifying the method of smoking.