Determination of micro-iron by molecular fluorescence in water

Based on the formation of Fe(Ⅱ)-phen complex which can reduce the fluorescence signal of phenanthroline,the determination of micro-iron in environmental water by fluorimetry is discussed in this paper.The experiments were carried out in the pH 5.5 acetic acid-acetate ammonium buffer solution at room temperature;and the complex excitation and emission wavelengths are 270 nm and 365 nm,respectively.Under optimum conditions,the fluorescence signal is linear with iron concentration in a range from 0.80 ng/mL to 120 ng/mL(R=0.9994).The detection limit of the method is 0.50 ng/mL for iron.The relative standard deviation of the method is 2.8%(n=9) for 60 ng/mL iron.The recoveries of iron by the method are 98.03%～102.9%.The method has been applied to the determination of micro-iron in water with satisfactory results.