FLUORIDE, cilt.36, sa.4, ss.267-270, 2003 (SCI-Expanded)
Infusion time and water hardness were examined for their effects on fluoride extraction from three different brands of tea (Caykur-Kamelya, Rize-Turist, and Lipton-Ceylon). With soft water (18 mg eq CaCO3/L), extraction after 10 min at 80degreesC was over 90% complete but only 75% complete with hard water (79 mg eq CaCO3/L). After extraction for 20 min with soft water, the water-soluble fluoride contents of the three brands of tea were determined as 98, 53, and 83 ppm, respectively. Addition of lemon or lemon juice to the tea extract did not change the free fluoride content.