In the Britton-Robinson buffer solution at pH=4.35 Congo red combines with protein by intermolecular forces,which resultes in an resonance light scattering(RLS).The RLS intensity reaches a maximum at the wavelength of 575 nm and is proportional to the concentration of protein.The method is simple and rapid with a linear range up to 8.0 μg/mL and a detection limit of 0.054 μg/mL.This method was applied to the determination of human serum protein and compared to Bradford method with a satisfactory result.
The enhanced effect with Potassium and Na-TPB by Resonance Light Scattering Turbidimetry（RLST） based on Potassium and Na-TPB form hydrophobe sol system was studied in this paper.The optimum reaction conditions and the quantitative relationships of the intensities of RLS to the concentration of potassium were established.The RLS intensity at 578 nm is maximum and proportional to the concentration of potassium.The method is simple and rapid with a detection limit is 0.124×10-6mol/L and a linear range is 0.0～4.6×10-4mol/L.
Chloride ion was determined by the resonance light scattering method.The results showed the RLS intensity of the blank solution was faint.While chloride ion was added,the RLS intensity enhanced quickly and was proportional to the concentration of choloride ions.The assay is simple,rapid and sensitive with the linear range up to 14.0 μg/mL and the detection limit at 0.04 μg/mL.The recoveries of the method found to be in the range of 98.7%—102% with RSD between 1.1% and 2.2%.This assay was applied to the determination of chloride ions in acid copper plating bath and in tap water,and the results were satisfactory.
