ABSTRACT
S2- and Ag+ form stable Ag2S nanoparticles in the presence of sodium dodecyl sulphate (SDS). It exhibits a strong resonance scattering peak at 470 nm and a strong fluorescence peak at 470 nm when excitation wavelength is at 200 nm. The effects of TAA and Ag+ concentration on the fluorescence intensities are consistent with those on the resonance scattering signals. The resonance scattering and fluorescence intensities all increase with Ag+ concentration in the range of 0-8.0 x 10(-5) mol x L(-1). The results verified that there is a correlation between the fluorescence and resonance scattering. The fluorescence is the interface fluorescence of Ag2S nanoparticles in liquid phase.
Subject(s)
Nanoparticles/chemistry , Silver Compounds/chemistry , Silver/chemistry , Spectrometry, Fluorescence/methods , Fluorescence , Light , Scattering, Radiation , Sodium Dodecyl Sulfate/chemistry , Solutions , Spectrometry, Fluorescence/instrumentationABSTRACT
A new simple, selective and sensitive method for the determination of trace chlorine dioxide in water has been developed, based on the oxidation by chlorine dioxide to reduction the fluorescence of rhodamine dyes in ammonia-ammonium chloride buffer solution. Four rhodamine dyes systems such as rhodamine S, rhodamine G, rhodamine B and butyl-rhodamine B were tested. The rhodamine S system is the best, with a linear range of 0.0060-0.450mugmL(-1) and a detection limit of 0.0030mugmL(-1) ClO(2). It was applied to the determination of chlorine dioxide in synthetic samples and real samples, with satisfactory results. This method has good selectivity, especially, other chlorine species such as chlorine, hypochlorite, chlorite and chlorate do not interfere the determination. The mechanism of fluorescence reduction was also considered.
