Determination of trace amounts of iron by a simple fluorescence quenching method

A simple and sensitive spectrofluorimetric method based on the reaction of iron and tiron in acidic medium is developed for the determination of Fe(III), which gives an intense fluorescence quenching that was measured at 345 nm (excitation at 292 nm). The fluorescence quenching extent is proportional to the iron concentration in the range of 34.0-840 ng mL(-1). A detection limit of 9.4 ng mL(-1) and a relative standard deviation (for 11 replicate measurements) of +/- 0.84% were obtained. Moreover, the factors affecting product fluorescence intensity, such as the pH, tiron concentration, reaction time and temperature, were investigated and optimized. This simple and sensitive method was successfully applied for the determination of trace amounts of iron in human hair, ferrous tablet, certified reference material and synthetic sample.