Determination of Hydrogen Peroxide Residue in Food Using CdS Quantum Dots as Fluorescence Probes

摘要

A simple and accurate method for determination of hydrogen peroxide (H_2O_2) using carboxymethyl cellulose coated CdS quantum dots (QDs) as a fluorescence probe was established. The influence factors of the fluorescence quenching system and the optimum conditions were investigated for analysis of hydrogen peroxide. It was found that the maximum relative fluorescence quenching intensity produced at pH 8.5 in 0.035 mol/L KH_2PO_4-Na_2HP_O4, when the concentration of CdS QDs was 1.9×10~(-3) mol/L and the reacting time and temperature were 45 minutes and 30°C, respectively. Under the optimum conditions, the relative fluorescence quenching intensity has a linear relationship with the logarithmic concentration of H_2O_2 in the range from 3×10~(-5) to 5×10~(-2) mol/L. The limit of the detection is 2.3×10~(-6) mol/L for H_2O_2. The method was used to determinate the amount of remained H_2O_2 in milk and Calcium Tablets successfully.