On the Resonance Light Scattering Property of the Reaction Between Europium(Ⅲ) and Carminic Acid

Resonance light scattering (RLS) property of the raction between Eu(Ⅲ) and carminic acid in Na2HPO4-citric acid buffer solution of pH 7.50 was studied. Upon the addition of Eu(Ⅲ) to the reaction solution containing definite amount of carminic acid, significant enhancement of intensity of RLS was observed at the optimum wavelength of 303 nm, and linear relationship between the magnitude of increase in RLS intensity ΔI(I-I0) and concentration of Eu(Ⅲ) was obtained in the range of 1.00×10-9-1.00×10-4mol·L-1, with the detection limit (3S/N) of 2.52×10-10mol·L-1.