Comparison of Two Analytical Methods for the Determination of Dimethylnitrosamine in Beer and Ale, and Some Recent Results

Abstract

The results obtained by a rapid Celite column extraction method for the determination of dimethylnitrosamine (DMN) in beer and ale were compared with those obtained by a more elaborate vacuum distillation method. The end determination in both cases was done by gas‐liquid chromatography using a thermal energy analyzer (TEA) detector. The two sets of results for 28 samples of beers from various countries were highly comparable. Recent survey results for both Canadian and imported beer and ales suggest a significant decrease in the levels of DMN in these beverages from that observed 2–3 years earlier. This decrease is probably due to the improvements in the malt drying techniques instituted in Canada as well as in other countries.

Trends in the Levels of N-Nitrosodimethylamine in Canadian and Imported Beers

“…The highest level of NDMA detected in each survey also decreased in a similar manner. The first decline could be attributed to the introduction in March 1979 of a modified direct maltdrying technique by the three major Canadian malting companies in which the sulfur-burning cycle was extended to 40-50 g of S/100 kg of malt during the first 8-10 h of drying (Sen et al, 1982). The second or the final decline occurred when all the maltsters in Canada switched to indirect drying by the end of 1981.…”

“…a Zero was used for <0.1 ppb. b For the details of sources, see Sen et al 1982. c Data reproduced from Sen et al (1982). d N ) undetectable (<0.1 ppb).…”

“…Determination of NDMA. The beer samples were analyzed either by a distillation method (Sen et al, 1982) or by a Celite column extraction method (Hotchkiss et al, 1981;Cutaia et al, 1982). Both are official AOAC International methods and have been shown to be highly accurate and reliable in two separate collaborative studies.…”