A new resonance scattering spectral method for the determination of trace amounts of iodate with rhodamine 6G Original Research Article

Under the conditions of 0.04 mol L−1 HCl–8.0 × 10−4 mol L−1 KI, there is a fluorescence peak at 540 nm and a synchronous fluorescence peak at 540 nm for rhodamine 6G (RhG). When there is IO3−, it reacts with exceed I− to form I3−. And I3− and RhG combine into ion association particles. The particles exhibit three resonance scattering peaks at 320, 400 and 595 nm. And there is fluorescence quenching at 540 nm. Iodine concentration is proportional to the intensity of the resonance scattering intensity at 400 nm in the range of 1.0–20 × 10−7 mol L−1. And a new resonance scattering spectral (RSS) 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 solid–liquid interfaces are the main factor that cause the fluorescence quenching and resonance scattering effects.