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.