Determination of Matrine by Glassy Carbon Electrode Modified with Partially Electrochemical Reduced Graphene Oxide

A glassy carbon electrode (GCE) modified with partially electrochemical reduced graphene oxide (pErGO) was used as the working electrode (pErGO/GCE) for the electrochemical determination of matrine (MT). Graphene oxide (GO) was dropped on the activated GCE, and then the pErGO/GCE was obtained by reducing GO to pErGO at -0.75 V for 200 s. Using 0.1 mol·L^-1 NaH₂PO₄-Na₂HPO₄ buffer solution (pH 7.0) as the electrolyte, platinum wire as the counter electrode and Ag/AgCl electrode as the reference electrode, MT in the sample was enriched at open circuit potential for 120 s and then determined by differential pulse voltammetry (DPV). The results showed that the concentration of MT was linearly related to its oxidation peak current in the range of 8.0×10^-6-1.0×10^-4mol·L^-1, with detection limit (3S/N) of 4.0 μmol·L^-1. RSDs (n=5) of the determined values was 1.8% by repeated determination of MT standard solution for 5 times with the modified electrode. Test for recovery was made on the actual samples by standard addition method, giving values of recovery in the range of 94.8%-104%. This method was used for the analysis of the actual sample, and the relative deviation between the determined value and the labeled value of MT was -5.9%.