Highly sensitive and selective fluorimetric methods for the determination of iron(III) and manganese(II) using fluorescein/hydrogen peroxide/triethylenetetramine and fluorescein/hydrogen peroxide/triethylenetetramine/tiron, respectively

Highly sensitive and selective spectrofluoriphotometric determinations of iron(III) with fluorescein(Fl)-hydrogen peroxide-triethylenetetramine (TETA), and manganese(II) with Fl-hydrogen peroxide-TETA-tiron are proposed. The methods are based on the inhibition of the oxidizing decomposition of Fl-hydrogen peroxide solution in the presence of iron(III)-TETA or manganese(II)-TETA-tiron combination. The calibration graphs are linear in the ranges of up to 220 ng iron(III) and up to 270 ng manganese(II) per 25 ml at an emission wavelength of 510 nm with excitation at 490 nm. By measuring the difference of relative fluorescence intensities (ΔF) between Fl-TETA-hydrogen peroxide and its iron(III) solutions or Fl-TETA-tiron-hydrogen peroxide and its manganese(II) solutions, the concentrations of iron(III) or manganese(II) are determined. The application of these methods to the analysis of iron(III) or manganese(II) in waste water was investigated with satisfactory results. © 1989 Springer-Verlag.