Determination of Cerium (IV) Using Rhodamine 6G Fluorescence Quenching

The interaction between rhodamine 6G (Rh6G) and cerium sulfate was studied by the fluorescence quenching method. In a sulfuric acid medium, the interaction of Ce(IV) with Rh6G results in Rh6G fluorescence quenching. The maximum excitation wavelength (λ_ex) and the maximum emission wavelength (λ_em) are 530 nm and 555 nm, respectively. A good linearity between the relative fl uorescence intensity (ΔF) and Ce(IV) was observed in the range ~0.12–1.08 μg/mL. The detection limit was 1.4 × 10^–3 μg/mL. The optimum reaction conditions, influencing factors, and effect of coexisting substances were investigated in the experiment. We found that the concentration of Rh6G was 3.2 × 10^–6 mol/L, and the fl uorescence intensity was maximum.