Speciation of aluminum and fluorine in a blend of green tea infusion and human gastric juice by ion chromatography and 19F-NMR
1999
Liang, J.Y. | Chung, R.S. | Lin, H.C.
The chemical species of aluminum and fluorine compounds in green tea infusion treated with or without gastric juice at different pH values were studied using ion chromatography and 19F-NMR. The fluoride ion was the dominant fluorine species in green tea infusion. At the simulated pH of human gastric juice, i.e., a pH value of about 2.5, the fluoro-Al species was the dominant fluorine species, and fluoride ion was negligible in green tea infusion with gastric juice. The aluminum species in green tea infusion was mainly oxalato-Al species. At the simulated pH of human gastric juice, both oxalato-Al and fluoro-Al species were dominant aluminum species, and the aluminum ion was negligible in green tea infusion with gastric juice. The aluminum species in green tea infusion with gastric juice under a concentration of 1.8 mM citrate and at a pH of 2.5 were mainly citrato-Al and fluoro-Al species.
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