Abstract: The effects of fluoride after subacute oral administration of NaF at levels of 0, 1, 5, 25, and 125 ppm F- were evaluated in adult male BALB/c mice. Fluoride levels in the murine liver, kidney, and cerebrum after one month were determined using a highly sensitive flow-injection apparatus with a fluoride ion selective electrode as the detector. To examine for neurotoxic effects, levels of regional brain neurotransmitters and their metabolites were determined by a high performance liquid chromatography procedure. Water intake increased among the groups administered 25 and 125 ppm F-, and the concentrations of fluoride in liver and kidney were significantly increased among the 125 ppm group compared to the control. On the other hand, the fluoride levels in the cerebrum were not significantly different among the groups. However, a significant difference was observed in homovanillic acid (HVA) in the hypothalamus. Significant differences in the levels of neurotransmitters and their metabolites were not observed in other brain regions. Copyright © 2005 International Society for Fluoride Research.

Abstract: Fluoride is separated from cartilage or aortic tissues without ashing by an adaptation of the method of Yoshida et al. (Anal. Abstr., 1979, 37, 6B109). The reaction takes place in a closed apparatus comprising a 100 mL flask in series with two gas bubblers, each containing 25 mL of 0.1 M NaOH. The sample, 50 mL of water and two drops of hexamethyldisiloxane are placed in the flask, and 40 mL of concentrated H2SO4 is added to the sample through a dropping funnel. The trimethylsilanol(I) produced reacts with the F- to form fluorotrimethylsilane(II), which is swept by N (50 mL min-1) to the bubblers. II is converted by the alkali back into I, which is extracted into toluene before measurement of the F- so liberated in 0.45 M HClO4 medium with an I--selective electrode. Urine is analyzed directly for F- in 0.5 M HClO4 medium containing 0.001% of Triton X-100 by using two F--selective electrodes in a flow injection system. The latter method was applied to urine of persons drinking fluoridated water or occupationally exposed to F. The former method was applied to tissues from adults and infants, and the results are reported.