Electrochemical Determination of Diethylstilbestrol in Animal Food Using a Poly Polylysine/Graphene Modified Electrode

摘要

A polylysine/graphene modified electrode was prepared. The electrochemical behaviour ofdiethylstilbestrol on the surface of this electrode was studied. A new method for the direct determinationof diethylstilbestrol in food was developed. The experimental results showed that there was a pair ofreversible redox peaks for diethylstilbestrol on this modified electrodes in 0.5~1.0 V range in a phosphatebuffer solution (pH 3.0). Compared with the effects of a glassy carbon electrode and a polylysinemodified electrode, it was concluded that the polylysine/graphene modified electrode has a higherelectrocatalytic effect on the oxidation of diethylstilbestrol. In the range of 8.00×10 -8 ~ 1.00×10 -5 mol/L,the concentration of diethylstilbestrol was directly proportional to its oxidation peak current, and thedetection limit is 1.20×10 -9 mol/L. The relative standard deviation（RSD） was 1.7% over six paralleltests. The modified electrode had a high sensitivity and good selectivity and better stability than thecontrol electrode and could be used to determine the concentration of diethylstilbestrol in beef, muttonand milk with recovery rates of 97.0% ~ 103.0%.