RESUMO
Results of aluminium determinations in breads and biscuits as well as in fish preserves, vegetables, strawberries and teas including fruit-herb teas are presented. Also the percent of extraction of aluminium of various kind of tea leaves into the infusions was determined. The commercially available sample of foods was used for investigation. Aluminium was determined by using two methods: a spectrophotometric extraction method with-hydroxyquinoline and less sensitive AAS method with nitrous oxide-acethylene flame on PU 9100X Philips Spectrometer could with IBM compatible Computer (Hundai) provided with 9178/9X Flame Program Unicam Limited--1991. The sample was at first digested with mixture of concentrated acids (H2SO4 + HNO3 + HClO4) in teflon vessels and then finished in platinum dishes. Solutions of the destroyed samples was kept in polethylene bottles. The methods was checked by recovery tests. In the 8-hydroxyguinoline-extraction-method about 88.5% to 106.5% of the added aluminium was determined and in the AAS method it was of 75% to 100%. The highest level of aluminium was found in the eas: from 445 to 1522 mg/kg (mean 879 mg/kg) and then in herb-fruit teas (consisting of dried herbs and fruits of sloe plum, briar-rose juneberry Aronia etc.) from 45 to 379 mg Al/kg of dry matter. About 29% of the metal was extracted from teas into the infusion. Lower levels was found in breads (0.0-92.0 mg mean 29.95 mg/kg) and in the fish preserves (0.0-57.0 mg mean 18.1 mg AL/kg). Similar levels were also found in 7 kinds of popular vegetables (0.0-100 mg mean 33.3 mg Al/kg). The lowest levels was found in strawberries (0.50-3.0 mg Al/kg). It was calculated that drinking three glasses of tea daily may supply about 2.6 to 3.7% of the provisional tolerable weekly intake dose set by the Joint FAO/WHO Expert Committee. It is concluded that the obtained results are similar to those published by other authors and represents a levels normally encountered in foods, and do not create any risk for human consumption.
