A microwave-assisted acid digestion procedure coupled with a graphite furnace atomic absorption method has been applied in
the determination of aluminum (Al) in urine to verify the correlation of free forms of Al in tea infusions and urinary excretion
of Al. Significant urinary Al excretion has been found in 24-h urine of four volunteers after tea drinking. However, the difference
in amount of Al excretion in urine between the consumption of Oolong (black tea) and Long-Jin (green tea), each of them with
unique Al contents and species, was not significant. These findings indicated that the high levels of free Al species in tea
infusions did not result in significant change in urinary excretion of the metal, possibly owing to the transformation by
ligands present in food and the gastrointestinal tract (GIT). However, it could not be assumed that there was no big difference
in absorption of the metal in the human body if fractions of consumed Al retained in the body or excreted by bile or feces
were considered.
Index Entries Aluminum - species - tea infusion - urine - digestion - atomic absorption spectrometry