A spectrofluorimetric sensor based on grape skin tissue for determination of iron(III)

A spectrofluorimetric method based on the grape skin has been developed for the determination of Fe3+ at pH 5.0. The emission wavelength of the grape skin sensor occurs at 680 nm and the excitation wavelength at 421 nm. The fluorescence of sensor could be quenched by Fe3+ due to the complexing ability of anthocyanin with the metal ions. Anthocyanin, the main pigment in the grape skin, has been found fluorescence sensing material. The sensor based on the grape skin exhibited a calibration response for Fe3+ in two concentration ranges of 1.0 × 10-8- 1.0 × 10-5 M(r2= 0.9888) and 3.2 × 10-5- 3.2 × 10-4 (r2 = 0.9856) M at 60 oC. The detection limit was found to be 7.5×10-9M, and the other common ions did not interfere. KEY WORDS: Grape skin, Fluorescence, Iron(III) Bull. Chem. Soc. Ethiop. 2010, 24(1), 31-37.