A simple thin-layer chromatographic technique for the semi-quantitative determination of volatile nitrosamines in alcoholic beverages

Abstract

A thin-layer chromatographic procedure is described for determining dimethyl-, diethyl-and dipropylnitrosamines in alcoholic drinks. Nitrosamines are first distilled from an alkaline solution of the sample and then extracted into dichloromethane. Ethanol and interfering materials are removed by co-distillation with hexane or benzene and chromatography on a basic alumina column. Finally, the nitrosamines are determined semi-quantitatively by thin-layer chromatography as nitrosamines or, after oxidation, as the corresponding nitramines. The method is sensitive down to 0·025 p.p.m. and applicable to various drinks such as wine, beer, whisky and rum. Percentage recoveries of added nitrosamines varied between 50 and 100 at the 0·1 p.p.m. level and between 20 and 100 at the 0·025 p.p.m. level.