Simultaneous cyclic voltammetric determination of norepinephrine, ascorbic acid and uric acid using TX-100 modified carbon paste electrode

Abstract

A sensitive and selective electrochemical method for the determination of norepinephrine (NE) using TX-100 modified carbon paste electrode was developed. The TX-100 modified carbon paste electrode shows excellent electrocatalytic activity towards the oxidation of NE in phosphate buffer solution (pH 7.0). The linear range of 0.5 × 10⁻⁴ to 2.0 × 10⁻⁴ M and detection limit of 5 × 10⁻⁶ M were observed at pH 7.0 phosphate buffer solution. The interference studies showed that the modified electrode exhibits excellent selectivity in the presence of large excess of ascorbic acid (AA) and uric acid (UA). The separation of the oxidation peak potentials for NE–AA and NE–UA were about 0.16 V and 0.11 V, respectively. The differences were large enough to determine AA, NE and UA individually and simultaneously. This work provides a simple and easy approach to selectively detect norepinephrine in the presence of ascorbic acid and uric acid in physiological samples.