Evaluation of aluminium concentrations in samples of chocolate and beverages by electrothermal atomic absorption spectrometry

Abstract

Samples of chocolate, cocoa, tea infusions, soft drinks and fruit juice have been examined by electrothermal atomic absorption spectrometry (ETA-AAS) for the presence of aluminium (Al). Fruit juices and chocolate were analysed after an adequate sample preparation; the other products were evaluated directly. Sampling was performed in duplicate for 248 independent samples. The mean Al concentration in chocolate was 9:2 ± 7:5 mg kg1, and individual values were correlated with the per cent of cocoa in samples (Y = 0:63 + 0:27X, r = 0:78, p < 0:0001). Al concentration in commercial tea infusions ranged from 0.9 to 3.3 mg l-1 (X = 1:80 ± 65 mg l-1), whereas in laboratory-prepared samples it was 2:7 ± 0:93mg l-1. In soft drinks, the concentrations of Al were lower, ranging from 9.1 to 179 μgl-1; the highest values were observed in samples of orange squash (X = 114 ± 56 μg l-1). Apricot juice showed the highest Al level (X = 602 ± 190 μgl-1), being statistically diOEerent from that of pear (X = 259 ± 102 μgl-1), but not diOEerent from that of peach juice (X = 486 ± 269 μgkg-1). Toxicologically, the amount of Al deriving from the consumption of these products is far below the acceptable daily intake of 1mg kg-1 body weight indicated by the FAO/WHO, and it is a very low percentage of the normal Al dietary intake.