The effect of Al (III) Chrysin Complex Reagent Composition on Determination of Fluoride Ion Spectrophotometry Qonitah Fardiyah, Barlah Rumhayati, Anisah Nabila Azzah
Chemistry Department, Faculty of Mathematic and Natural Science Brawijaya University, Indonesia
Abstract
Fluoride ion in water could be determined with metal flavonoid complexes such as Alumunium and ,7-dihydroxy-flavone (chrysin)complex. In this research, the optimum composition of the Al-chrsyin complex reagent on determination of fluoride ion spectrophotometry was studied. The complex reagent used ethanol as the solvent. This method relied onto the reaction of yellow coloured metal-chrysin complex with fluoride ions which resulted in colourless complex. The reaction corresponded with the concentration of fluoride in water. AlCl3 and Al(NO3)3 were used as the metal in the metal-chysin complex. The stoichiometry of the complex was investigated using Job^s method with continuous variation. Both aluminium variations resulted with 1:3 complex. The equilibrium time of Al(III)-Chrysin complex reagents were determined by simple procedure using UV-Vis spectrophotometry with 371 nm as maximum wavelength. The result shows that the Al(NO3)3-Chrysin complex reagent obtained 155 minute and 175 minutes for the AlCl3-Chrysin complex reagent respectfully. The limit of detection, limit of quantification and correlation coefficient for the determination of fluoride in water with Al(NO3)3-chrysin complex were found to be 1,25 ppm- 3,77 ppm- and 0,999.
Keywords: fluoride, chrysin, metal, ligand, UV Vis spectrophotometry
