N-NITROSO COMPOUNDS IN CIGARETTE TOBACCO AND THEIR OCCURRENCE IN MAINSTREAM TOBACCO-SMOKE

The tobacco and mainstream smoke of 20 commercial brands of filter and non-filter cigarettes were analysed for N-nitroso compounds. The concentrations of N-nitrosodimethylamine (NDMA), N-nitrosoethylmethylamine (NEMA) and N-nitrosopyrrolidine (NPYR) in cigarette tobacco were very much lower than in mainstream smoke, where the levels were 6.3 - 76.4 ng/cig NDMA, < 1.0 - 7.1 ng/cig NEMA and 3.9 - 41.2 ng/cig NPYR. N-Nitrosodiethylamine was not detected in mainstream smoke and N-nitrosopiperidine (< 1.0 ng/cig) was detected in the smoke of four unfiltered cigarette brands. The five major non-volatile nitrosamines present in cigarette tobacco were 4-(N-nitroso-N-methylamino)butyric acid (not detected to 200 ng/cig), N-nitrosopipecolic acid (not detected to 670 ng/cig), N-nitrososarcosine (22 - 460 ng/cig), 3-(N-nitroso-N-methylamino)propionic acid (110 - 4990 ng/cig) and N-nitrosoproline (580 - 15000 ng/cig). The tobacco-specific nitrosamines N-nitrosoanabasine and N-nitrosoanatabine were found at levels of 270 - 2330 ng/cig and 18 - 205 ng/cig in cigarette tobacco and mainstream smoke respectively. N-Nitrosonornicotine was present at 400 - 5340 ng/cig and 19 - 855 ng/cig in cigarette tobacco and mainstream smoke respectively. 4-(N-Nitrosomethyl-amino)-1-3-pyridyl)-1-butanone concentrations of 100 - 960 ng/cig and 21 - 470 ng/cig in cigarette tobacco and mainstream smoke were determined. 4-(N-Nitrosomethyl-amino)-4-(3-pyridyl)-1-butanol (iso-NNAL) was detected in four dark (French) tobacco unfiltered cigarettes at a concentration range of 140 - 240 ng/cig and 5 - 11 ng/cig in the corresponding mainstream smoke. For non-filter cigarettes, a transfer rate of 3.4 - 4.6% for iso-NNAL was calculated.