Determination of transition metal irons based on quenching of the rare earth luminescence

The determination of heavy metal ions was investigated by the use of rare earth ions (Eu3+) as spectroscopic probes. A few heavy metal ions efficiently quenched the luminescence of Eu3+ in polymerized cellulose films which were obtained by sodium carboxymethyl cellulose (Na-CMC) solution and EuCl3 solution or the mixed solution of EuCl3 and a heavy metal chloride. Also, the decay time of Eu3+ ions (τ) in Eu3+–Cu+, Eu3+–Cu2+ system was shorter than that of only Eu3+ system (τ0). The linear relationship between the concentration of copper ions (Cu+ or Cu2+) and τ0/τ reflected the dynamic quenching, as predicted by the Stern–Volmer equation. The method proposed appears the detection of heavy metal ions in environmental waters.