Concentration of fluoride and selected other elements in teas.

Infusions made from 15 Chinese, 11 Ceylon/Indian and 6 herb teas (1 g/100 ml deionized water at 85 degrees C) were analyzed for F, P, Ca, Al, Mg, Mn and Zn. Chinese teas continued to release F throughout the first hour of infusion, whereas release of F from Ceylon/Indian teas was essentially completed after 5 minutes. After a 15-minute infusion, the mean F concentration in Chinese teas was 1.73 ppm, and in Ceylon/Indian teas it was 1.24 ppm. Herb teas contained a negligible amount of F (0.02-0.05 ppm). Phosphorus and Mg were the most abundant of the other elements with an average of 12.5 and 9.1 ppm, respectively. A high correlation (r = 0.81) was found between the released F and Al. The total F content in tea leaves ranged from 82 to 371 ppm. The addition of milk to tea infusions did not appreciably reduce the F concentration. The estimated daily F intake from tea infusion made with fluoridated water at 0.7 ppm is 1.05 mg.