Determination of heavy metal ions based on quenching of the rare earth luminescence

The determination of heavy metal ions based on quenching of the rare earth luminescence was investigated. A few heavy metal ions efficiently quenched the luminescence of Ce3+ in polymerized cellulose films, which were obtained by Na-CMC (sodium carboxymethyl cellulose) solution and CeCl3 solution or the mixed solution of CeCl3 and a heavy metal chloride. Also, the decay time of Ce3+ ions (τ) in Ce3+–Cu+, Ce3+–Cu2+, Ce3+–Zn2+ and Ce3+–Pb2+system was shorter than that of only Ce3+ system (τ0). The linear relationship between the concentration of Cu2+, Zn2+ or Pb2+ ions andτ0/τ reflected the dynamic quenching, as predicted by the Stern–Volmer equation.