Resonance Rayleigh Scattering of K2Zn3[Fe(CN)6]2 Nanoparticles and its Application for the Determination of Vitamin C

In Britton-Robinson buffer medium, (pH 4.43), potassium ferricyanide (K3[Fe(CN)6]) could react with vitamin C (VC) to produce potassium ferrocyanide (K4[Fe(CN)6]), which further reacted with Zn2+ to form potassium zinc hexacyanoferate K2Zn3[Fe(CN)6]2 nanoparticles. The shapes and diameters of the K2Zn3[Fe(CN)6]2 nanoparticles have been observed with transmission electron microscopy, which showed the shapes of these nanoparticles was cubic and their average sizes were about 50nm in the presence of 2.010-5 mol L-1 VC. The characteristics of resonance Rayleigh scattering (RRS) spectra of this reaction have been studied. The optimum reaction condition for the determination of VC has been investigated. It was found that the RRS intensity of the system at the RRS peak of 363.4nm was proportional to the VC concentration in the range of 4.0-80.0mol L-1, and the detection limit (3) for VC was 0.075mol L-1. A novel and simple RRS method for the determination of VC based on the formation of K2Zn3[Fe(CN)6]2 nanoparticles has been established.