Fluorophotometric Determination of Fe(Ⅲ) with the Pigment of Peel of Elaeagnus Angustifolia as Fluorescence Probe

Peel of elaeagnus angustifolia was extracted ultrasonically with water to obtain a yellow colored extract of pigment of peel of the above mentioned plant.The extract was then purified by passing through SPE column filled with AB-8 adsorptive resin and eluting with C2H5OH-H2O mixture (7+3).The ethanolic eluate was further concentrated by vacuum-evaporation,to obtain the fluorescent pigment solution.It was found that the fluorescence of the pigment solution was quenched by its combination with Fe(Ⅲ) ion,and that the magnitude of decrease in fluorescence intensity kept linear relationship with concentration of Fe(Ⅲ) in the range of 2.0×10-6-6.0×10-5mol·L-1.Based on these facts,a fluorophotometric method for determination of Fe(Ⅲ) using this pigment as fluorescence probe was proposed.Detection limit (3S/N) of the method was found to be 1.0×10-7mol·L-1.Recovery of the method was tested by the standard addition method,giving values of recovery in the range of 99.5%-101.5%.