Differential Pulse Voltammetric Determination of Morphine Hydrochloride with GE/Nano-Au Composite Modified Glassy Carbon Electrode

The Graphene (GE)/nano-Au composite modified glassy carbon electrode was prepared, and the composite film was characterized by SEM. The electrochemical behavior of morphine hydrochloride at this modified electrode was studied by cyclic voltammetry and differential pulse voltammetry. Significant electrocatalytic action on the reaction of morphine hydrochloride at the modified electrode was observed, giving an oxidation peak in PBS of pH 6.8. Based on this fact, a method of differential pulse voltammetry was proposed for determination of morphine hydrochloride. Linear relationship between values of oxidation peak current and concentration of morphine hydrochloride was obtained in the range from 2.0×10-7 to 4.0×10-4mol·L-1 , with detection limit of 7.0×10-8mol·L-1. Precision of the method was tested at the concentration level of 1.0×10-5mol·L-1 morphine hydrochloride standard solution for 20 determination, value of RSD found was 3.97%.