Presence and distribution of arsenical species in beers.

The total content of arsenic and of its inorganic (As(III) and As(V)) and organic (monomethylarsonic acid, MMAA, and dimethylarsinic acid, DMAA) species were determined in a set of 21 alcoholic and alcohol-free beer samples using the technique of Hydride Generation Atomic Absorption Spectrometry. For total arsenic analysis, beer samples were dried and then microwave digested with nitric acid in polytetrafluoroethylene containers. For the speciation analysis, beers were previously subjected to ion exchange chromatography to elute the mentioned inorganic and organic arsenical species. Both microwave digestion and chromatographic separation methods were validated from certified reference materials and prepared standard solutions, respectively. The results obtained are presented in terms of the distribution and occurrence of arsenical species in the samples. The As levels of the beer samples were in the range of 1.5-12.4 micrograms/l. The influence of the production process for the alcohol-free beers in the speciation of arsenic is discussed. In alcoholic beers MMAA was the most abundant species, and for non-alcoholic beers inorganic As(III) was similar to the organic species. An estimated intake of total As of 0.47 microgram/person/day and 11.4 micrograms/person/day was obtained for average consumers and for heavy drinkers, respectively.