Speciation of aluminium in tea infusions studied by size exclusion chromatography with detection by post-column reaction.

Aluminium-organic species in tea infusions were studied by size exclusion chromatography, using a Superose 12 HR column, a mobile phase of 0.12 mol l-1 tris(hydroxymethyl)aminomethane adjusted to pH 5.5 and detection by UV-visible spectrophotometry. Aluminium was detected after post-column reaction with pyrocatechol violet at 585 nm and the organic material was detected at 280 nm. Teas of different origin were analyzed; the results indicate that aluminium is bound to the same relatively narrow size-range of large organic molecules in the tea infusions, irrespective of the origin of the tea.