THE BEHAVIOR OF LEACHED ALUMINUM IN TEA INFUSIONS

The behavior of leached aluminium (Al) was studied using GF-AAS with d ifferent sample pretreatments and RP-HPLC with lumogallion as the prec olumn reagent. The results showed that Al species in tea infusion coul d be categorized into three groups: large organic compounds, small sta ble organic compounds and free form Al. The compositions of Al species in a tea infusion would vary with the method of the tea production. F or non-fermented teas such as Long-Jin and Moli-Hua, most of the leach ed Al in the first tea infusion was in large organic compounds and sma ll stable organic compounds, and free form Al consisting of less than 10%. In the case of semi-fermented and fully fermented teas such as Sh uihsien and Pu-Erh, the main compositions of Al species in the first i nfusion were free form Al and small stable organic compounds, while Al in large organic compounds made up about 14% and 4%, respectively. Wh en l-g tea leaves were infused with 100 ml boiling water, about 21% Al in the tea leaves was leached into the water in the first infusion an d a total of about 27% of the Al in the tea leaves was leached into th e water in four infusions.