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(W/EH069) Determination of toxic metals in beer and cereals using electrothermal atomic absorption spectrometry. Hernandez-Cordoba, Manuel1, Perez-Sirvent, Carmen1, Vinas, Pilar1, Merino, Beatriz1, Aguinaga, Nerea1, 1 ABSTRACT- Beer and the products used in its manufacturing, cereals (barley), yeast and hops, are subject to certification ensuring chemical specifications for trace metals. Contamination of the cereals by environmental industrial emissions could produce toxicological problems. Most of the papers published are based on prior dissolution of the samples and determination using electrothermal atomic absorption spectrometry (ETAAS). Digestion methods of these products require dry ashing and acid treatments, involving the risk of contamination or loss of the metals and it is clear that methods involving minimal sample handling are required. The introduction of solid samples in ETAAS has practical advantages over time-consuming conventional procedures based on total dissolution of the samples. In this communication, new procedures for the determination of the metals cadmium, copper and aluminium in beer and the products used in its manufacturing, directly introducing the samples into the atomizer as slurries are described. Suspensions contained 30% v/v hydrogen peroxide, 0.5% v/v nitric acid and a matrix modifier, 0.2% m/v ammonium dihydrogenphosphate, for cadmium atomization. Problems derived from the accumulation of carbonaceous residues are solved with the addition of nitric acid and hydrogen peroxide which destroy the organic matter during the heating cycle. Different samples of beer (with and without alcohol), beer in fermentation process, must, yeast, malt, barley and hops were analyzed using the proposed procedure. Cadmium was found at levels between 0.1 and 1.3 ng/ml for the liquid samples and between 0.01-0.08 ng/g for the solid samples. Copper and aluminium were found at higher levels. Key words: beer, toxic metals, copper, cadmium |
