Report of collaborative studies of the determination of volatile nitrosamines in cheese and pesticides
Castegnaro, M.; Walker, E.A.
Iarc Scientific Publications 1980(31): 445-453
1980
ISSN/ISBN: 0300-5038 PMID: 7228271 Document Number: 168329
Portions of 2 Gouda cheeses from the same batch and initially containing nitrate and nitrite at about 25 and 0.5 mg/kg, resp., were either spiked with volatile nitrosamines or left unspiked, and sent to 15 laboratories for analysis by various methods. Reported recoveries for the nitrosamines were 65-100%. Statistical evaluation of results produced in 12 laboratories with methods using chemiluminescence detection gave overall mean values and s.d. of ( mu g/kg) 8.11 plus or minus 5.8 for N-nitrosodimethylamine (NDMA), 13.31 plus or minus 3.76 for N-nitrosodiethylamine, 12.18 plus or minus 3.51 for N-nitrosopiperidine and 7.43 plus or minus 4.99 for N-nitrosopyrrolidine (coeff. of variation 71.5, 28.2, 28.8 and 67.1%, resp.), amounts added being 5.8, 14.4, 15 and 6.6 mu g/kg, resp. Separate analysis of results for other methods of detection indicated that NDMA values were higher with detection systems other than those based on chemiluminescence, the latter tending to give more accurate results and better interlaboratory reproducibility. Further evaluation suggested that distillation from paraffin oil and gas chromatography/thermal energy analysis is likely to be the most accurate method.