Determination of trace metallothioneins at nanogram levels with Eosin Y by resonance light scattering method

摘要

The interactions of metallothioneins with Eosin Y were studied by the absorption spectra and resonance light scattering (RLS) spectra methods. A direct RLS spectra method was applied for the determination of trace metallothioneins. The interaction of Eosin Y and metallothioneins enhanced the RLS intensity of system in Britton-Robinson buffer (pH 3.91), with the help of anionic surfactant (sodium dodecyl benzene sulphate). The mechanism was studied and discussed in terms of the RLS and UV-absorption spectra. Under optimal experimental conditions, at 366nm, there was a linear relationship between the RLS intensity and the concentration of the metallothioneins in the range of 0.04-14.0 mu g mL(-1), with a correlation coefficient of r=0.9985 and detection limit of 11.9ng mL(-1). The relative standard deviation was 3.1% (n=11), and the average recovery was 95.2%. The method proposed was reliable, selective and sensitive in determining trace metallothioneins in human urine samples with the results in good agreement with those obtained by high-performance liquid chromatography.