罗丹明6G缔合微粒共振散射光谱法测定过氧化氢

在0.020mol.L-1HCl-4.0×10-4mol.L-1KI-1.6×10-5mol.L-1Mo(Ⅵ)介质中,罗丹明6G(RhG)在540nm处有1个荧光峰,在540nm处有1个同步荧光峰。当有H2O2存在时,H2O2与过量的I-反应生成I3-,I3-与RhG形成缔合微粒,在320,400,595nm处产生3个共振散射(RS)峰;而在540nm处荧光峰猝灭。H2O2浓度在0.068~34μg.mL-1范围内与400nm波长处的共振散射光强度呈线性关系。据此建立了一个测定水中H2O2的共振散射光谱分析法。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RS增强和荧光猝灭的根本原因。

Resonance-Scattering Spectral Determination of H2O2 Using Rhodamine 6G Association Particles

Under the conditions of 0.02 mol x L(-1) HCl-4.0 x 10(-4) mol x L(-1) KI-1.6 x 10(-5) mol x L(-1) Mo(VI), there is a fluorescence peak at 540 nm and a synchronous fluorescence peak at 540 nm for Rhodamine 6G (RhG). When there exists H2O2, it reacts with I- to form I3-. RhG and I3- combine to form an ion association particle. The particles exhibit three resonance scattering peaks at 320 nm, 400 and 595 nm respectively. And there is fluorescence quenching at 540 nm. H2O2 concentration in the range of 0.068-34 microg x mL(-1) is proportional to the resonance scattering peak at 400 nm. And a new resonance scattering spectral method has been described for the determination of H2O2 in water samples. The spectral results have verified that the formation of (RhG-I3)n association particles and the interface are the main factor that causes the fluorescence quenching and resonance scattering effects.