The effect of Al (III) chrysin complex reagent composition on determination of fluoride ion spectrophotometry

Fluoride ions in water could be determined with metal flavonoid complexes such as Aluminium and,7-dihydroxyflavone (chrysin)complex. In this research, the optimum composition of the Al-chrysin complex reagent on the determination of fluoride ion spectrophotometry was studied. The complex reagent used ethanol as the solvent. This method relied on the reaction of the yellow-colored metal-chrysin complex with fluoride ions which resulted in a colorless complex. The reaction corresponded with the concentration of fluoride in the water. AlCl3 and Al(NO3)3 were used as the metal in the metal-chrysin complex. The stoichiometry of the complex was investigated using Job's method with a continuous variation. Both aluminium variations resulted in the 1:3 complex. The equilibrium time of Al(III)-Chrysin complex reagents were determined by a simple procedure using UV-Vis spectrophotometry with 371 nm as the maximum wavelength. The result shows that the Al(NO3)3-Chrysin complex reagent obtained 155 minutes and 175 minutes for the AlCl3-Chrysin complex reagent respectively. The limit of detection, the limit of quantification, and correlation coefficient for the determination of fluoride in water with Al(NO3)3-chrysin complex was found to be 1,25 ppm; 3,77 ppm; and 0,999.