Monitoring of selected aflatoxins in brewing materials and beer by liquid chromatography/mass spectrometry

In 2008-2011 a total set of 333 samples of brewing raw materials and beer were analyzed for the presence of aflatoxins B1, B2, G1 and G2. The standard analytical method using high-performance liquid chromatography coupled to mass spectrometric detection with immunoaffinity column clean-up was applied. The method was validated. Limits of detection varied from 0.04 to 0.12 μg/kg in barley and malt, 0.08-0.58 μg/kg in different hop samples, 0.04-0.12 μg/kg in brewers' yeast and spent grains and 1.5-4.7 ng/l in beer. Limits of quantification varied from 0.13 to 0.39 μg/kg in barley and malt, 0.25-1.94 μg/kg in different hop samples, 0.13-0.39 μg/kg in brewers' yeast and spent grains and 5.1-15.2 ng/l in beer. In 7 of 216 samples of brewing raw materials (3.2%), aflatoxins were found at trace concentrations to 1.2 μg/kg. In 6 of 117 (5.1%) beer samples, aflatoxins were detected at concentrations to 31.0 ng/l. Values in barley and malt did not exceed the maximum allowable limit set by the European Union.

► Simultaneous determination of four aflatoxins in brewing materials and beer. ► Purification of samples using immunoaffinity and multifunctional clean-up column. ► Fast HPLC method with mass spectrometric detection. ► 3.2% of brewing materials and 5.1% of beers contained aflatoxins above LOQ.