A method for the determination of fluoride by reversed-phase, high-performance liquid chromatography (RP-HPLC) is described. Fluoride, La 3+ and alizarin complexone form F-La3+-alizarin complexone ternary complex, which is separated from the matrix on a RP, Ultrasphere C 18 column (250 x 4.6 mm, 5 μm) using methanol-water (19:81, v/v] mobile phase at 1.00 ml min-1; detection at 568 nm. The calibration graph was linear from 1.0-150 ng mL-1 for fluoride with a correlation coefficient: 0.9993 (n = 6). The detection limit was 0.2 ng mL-1. The method was successfully applied to the determination of fluoride in river and tap water. Recovery was: 94-102%, RSD in the range: 1.9-3.6%.
- Column liquid chromatography
- Fluoride - alizarin complex
- Fluoride in river and tap water