Determination of copper by differential pulse voltammetry based on hematoxylin and graphene modified glassy carbon electrode

Graphene was coated on glassy carbon electrode(GCE) while hematoxylin was electrodeposited on the graphene film to construct the modified electrode.Electrochemical method for trace copper determination was developed using this modified electrode with differential pulse voltammetry.It was indicated that the peak currents varied linearly with the concentration of Cu2+ over the range from 5×10-8 to 2×10-6 mol/L with the correlation coefficent of 0.992 and 0.996,through the determination of peak current at 0.13 V after the sample was accumulated for 4 min at-0.3 V in a 0.1 mol/L pH 4.2 NaAc-HAc buffer.The detection limit was 2×10-9 mol/L.The proposed method was used to determine trace copper in industrial wastewater with the relative standard deviations of 4.3%-5.7%.The results agreed well with those obtained by ICP-AES method.