罗丹明6G缔合微粒荧光猝灭法测定痕量碘酸根

研究发现在0.01mol/LHCl-8.0×10-4mol/LKI介质中,罗丹明6G(RhG)在550nm处有1个荧光峰.当有IO-3,I-3与RhG形成缔合微粒,550nm处荧光峰猝灭,在320、400、6103存在时,IO-3与过量的I-反应生成I-nm处有3个共振散射峰,在470nm处有1个同步散射峰.碘酸根浓度在2.0～100×10-7mol/L范围内与荧光猝灭强度成线性关系.据此建立了一个测定食盐中IO-3的荧光猝灭分析法.光谱研究结果表明,(RhG-I3)n缔合微粒和界面的形成是导致体系荧光猝灭的根本原因.

Fluorescence Quenching Determination of Trace IO3- Based on Formation of Rhodaine 6G Association Particles

Under the conditions of 0.01 mol/L HCl-8.0 10^-4 mol/L KI, there is a fluorescence peak at 550 nm for Rhodamine 6G (RhG). When there is IO₃^-, it reacts with I^- to form I₃^-. RhG and I₃^- combine an ion association particle. The particles exhibit three resonance scattering peaks at 320, 400 and 610 nm and a synchronous scattering peak at 470 nm. And there is fluorescence quenching at 550 nm. IO₃^- concentration in the range of 2.0 to 100×10^-7 mol/L is proportional to the fluorescence quenching intensity at 550 nm. A new fluorescence quenching method has been described for the determination of IO₃^- in salt samples. The spectral results have been verified that the formation of (RhG-I₃)_n association particles and the interface is main factor that cause the fluorescence quenching effects.