The absorption by food of aluminium from packaging materials was determined by measuring the dissolution of aluminium and the free aluminium ion. Total aluminium was determined by flameless atomic absorption spectrophotometry, and the aluminium ion, by chromazurol-S absorptiometry. In the case of beer that had been canned for 5 months, a larger amount of aluminium had been absorbed than by beer canned for 2 months, although the ionization ratio was almost the same at 30-40%. Preservation of the canned beer for longer resulted in the aluminium dissolution being increased and the free aluminium ions also being increased by 10%. Aluminium foil treated with several kinds of solution resulted in its greatest dissolution in the order of acetic acid, citric acid, sodium chloride and distilled water. The ionization ratio (free aluminium ions/aluminium content × 100) was highest in acetic acid at 60%, and then in distilled water at 45%, while no aluminium ions were dissolved in the citric acid solution.