Quantitative Determination of Iron Ions Based on a Resonance Raman (RR) Probe-Phenanthroline.

In this paper, we demonstrate a new promising resonance Raman (RR)-based method for the determination of Fe3+ concentrations in aqueous solutions. Iron ions were quantified at a low concentration range by employing hydroxylamine hydrochloride as the reductant, and phenanthroline as the complexing agent, thereby reducing Fe3+ to Fe2+. The addition of Fe3+ to the detection reagent resulted in a rapid color change from colorless to orange-red, together with an obvious new RR band appearing at 1459 cm-1. Herein, the RR intensity of the phenanthroline-Fe2+ complex strengthened with increasing Fe3+ concentration, which was identified from the variation of the Raman spectra. Therefore, we successfully detected Fe3+ at lower concentrations using the proposed method, illustrating its great potential for the detection of Fe3+ with abundant RR fingerprint information. More importantly, the proposed method exhibited a wide liner range from 0.05 to 10 μg/mL.