Table 2.
Determination of the fluoride anion in tap water and river water samples (n = 3) [a].
| Samples [b] | Amount of Fluoride (ppm) | Recovery (%) | |
|---|---|---|---|
| Added | Found | ||
| Tap water | 0.50 | 0.51 ± 0.02 | 102.7 ± 4.2 |
| 5.0 | 4.82 ± 0.08 | 96.4 ± 1.5 | |
| River water [c] | 0.50 | 0.52 ± 0.03 | 104.0 ± 5.3 |
| 5.0 | 4.87 ± 0.07 | 97.3 ± 1.3 | |
[a] The measurements were recorded 40 min after the addition of fluoride. [b] The tap water and river water samples were diluted 2-fold and 10-fold, respectively, by the addition of 10 mM HEPES buffer solution (pH 7.4). [c] The river water samples were filtered through celite before measurements.