This article reports about the electrochemical determination of L-arginine on a glassy carbon electrode in a dietary supplement using anodic differential pulse voltammetry. The expo-nential depense of the peak current on the square root of the scan rate (I/v1/2), the shifts of the po-tential to the negative area and linear correlation between peak potential and logarithm of the scan rate (lg(v) confirms that electrooxidation of L-arginine is an irreversible process. Moreover, the criteria of Semerano equals 0.4 may indicate the process of electrooxidation without adsorp-tion. The effect of pH, accumulation potential, accumulation time and scan rate was tested on electrochemical behavior of L-arginine. Working conditions for L-arginine determination in model media are following: pH 13; Eacc 0.3 V, tacc 30 s; v = 60 mV s-1. A linear dependence of L-arginine electrooxidation current on its concentration was observed at the 0.9 V in the range between 1.010-4 and 1010-4 mol l-1. The detection limit was 1.3410-6 mol l-1. A comparative determination of L-arginine in dietary supplement was carried out by the voltammetric method and capillary electrophoresis. Thus, the determination of L-arginine in a dietary supplement on a glassy carbon electrode in NaOH solution (pH 13) was successfully carried out using anodic differential pulse voltammetry. The proposed method does not require sample preparation and allows to quickly deter-mine L-arginine in dietary supplement.
- Amino acid
- Anodic differential pulse voltammetry
- Dietary supplement
ASJC Scopus subject areas
- Chemical Engineering(all)