Determination of Concentrated Hydrogen Peroxide Free from Oxygen Interference at Stainless Steel Electrode.

H2O2 is frequently used at high concentrations in various applications. It is very challenging to detect high concentrations of H2O2 and to eliminate oxygen interference for H2O2 detection through electrochemical reduction. In the present investigation, the electrochemistry of H2O2 at stainless steel electrode has been carried out for the first time. A cathodic peak for H2O2 reduction was observed at about -0.40 V, and no cathodic peak for dissolved oxygen reduction was observed on type 304 stainless steel electrode. Amperometric determination of H2O2 on type 304 stainless steel electrode displayed a linear range from 0.05 up to 733 mM with a detection limit of 0.02 mM (S/N = 3) and a sensitivity of 16.7 μA mM-1 cm-2. The type 304 stainless steel electrode not only shows much higher upper limit than other reported electrodes for the detection of concentrated H2O2 but also is free from oxygen interference, which is of great importance for practical applications. This method could detect H2O2 in wound wash and lake water with excellent recoveries. Moreover, we successfully applied the stainless steel electrode to determine glucose using glucose oxidase to catalyze the oxidation of glucose to generate hydrogen peroxide. The linear range for glucose is between 0.5 and 25 mM, which covers clinically important blood glucose concentrations well.