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Gas-Liquid Chromatographic-Thermal Energy Analyzer Determination of N-Nitrosodimethylamine in Beer: Collaborative Study

1982; Oxford University Press; Volume: 65; Issue: 3 Linguagem: Inglês

10.1093/jaoac/65.3.720

0004-5756

Nrisinha P. Sen, Stephen W. Seaman, Miķelis Bickis, M. Castegnaro, G. Ellen, Thomas Fazio, Walter Fiddler, David H. Fine, William C. Herwig, Phillip Issenberg, A.B. Lacey, R. Massey, T. J. O'Brien, Richard A. Scanlan, G Thomas, Jens Kirk Thomsen,

Analytical Chemistry and Chromatography

The GLC/TEA method for N-nitrosodimethylamine (NDMA) in beer was studied collaboratively by 13 laboratories from 7 countries. Collaborators were asked to analyze a total of 10 randomly labeled samples of beer consisting of the following duplicates: a naturally contaminated commercial beer; a beer extremely low (ca 0.1 ppb) in NDMA; and the low NDMA beer spiked with 0.5, 1.9, and 5.0 ppb NDMA. The pooled repeatability and reproducibility coefficients of variation (CV) for all samples were 17% and 27%, respectively. However, when data from 2 laboratories (outliers) were omitted, the corresponding CV values improved considerably (11% and 15%, respectively). Variance analysis showed the presence of a significant laboratory-sample interaction when all data were used for analysis, but this interaction disappeared when data from the 2 outlying laboratories were excluded. The pooled percent recovery of the overall method (omitting outliers) was 101.4 +/- 3.5. All the laboratories detected NDMA in the low NDMA beer. The method was adopted official first action.