Determination of Uric Acid in Human Urine by Differential Normal Pulse Voltammetry With a Bare Glassy Carbon Electrode

This study investigates the electrochemical behavior of uric acid (UA) in the presence of ascorbic acid (AA) using differential normal pulse voltammetry (DNPV), aiming to establish a rapid and reliable method for UA detection without electrode modification. In DNPV, interference from AA was effectively suppressed by its pre‐oxidation during the initial potential pulse. A systematic evaluation of pulse parameters revealed that a first‐pulse width of 1000 ms and a pulse amplitude (ΔE) of 0.15 V provided optimal conditions, under which AA was almost completely depleted and the current response was dominated by UA oxidation. Under these optimized conditions, UA could be selectively quantified over the range of 0–300 μM, even in the presence of 100 μM AA. Application to human urine samples demonstrated good agreement with results obtained from enzymatic colorimetric assays, validated through the standard addition method after 100‐fold dilution.