Study the Effect of Concentration on Spectroscopic Properties of Fluorescein Sodium dye in Ethanol


The aim of research is study The spectral properties (absorption and fluorescence) for Fluorescein Sodium dye by solving it in Ethanol ,at different concentrations (5*10-5,7*10-5 ,1*10-4 , 5*10-4 , 7*10-4 ) mol/L at room temperature . The intensity of absorption increased and fluorescence decreased while concentration increases with agreement of Beer – Lambert Law. The absorption spectrum has been observed when it taken a wide spectral range, so when increased the concentration each peak shifted to a long wavelength. The fluorescence spectrum followed and entirely the same as absorption spectrum, so increase concentration shifted peaks to long wave length too. The quantum efficiency of the dissolved Fluorescein Sodium dye in Ethanol has been calculated for the same above concentration were (88%,85%,70%,55%,53%) respectively. In addition to the radiative life time was (0.55,0.91,1.3,3.67,5 )ns and the fluorescence life time (0.49,0.77,0.9,2.03,2.75 )ns respectively.