Simultaneous voltammetric determination of epinephrine and serotonin at a p-tetra-butyl calix [6] arene-L-Histidine chemically modified electrode

A new p -tetra-butyl calix [6] arene-L-Histidine chemically modified glassy carbon electrode (BCH/GCE) has been proposed for simultaneous investigation and determination of epinephrine (Ep) and serotonin (5-HT) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In potassium dihydrogen phosphate-borax (PDPB) buffer solution (pH 5.8), the anodic peaks of Ep and 5-HT were observed at 0.27 and 0.45 V, respectively, with E up to 180 mV. The peak currents on the DP voltammogram are in a linear relationship with the concentrations of Ep in the range of 1.0 × 10 −6 −1.30 × 10 −4 M in the presence of 1.0 × 10 −4 M 5-HT. A linear relationship was similarly found for 5-HT in the range 1.0 × 10 −6− 1.40 × 10 −4 M in the presence of 1.0 × 10 −4 M Ep. It is found that Ep and 5-HT could be simultaneously determined with good sensitivity in the presence of 1.0 × 10 −3 M ascorbic acid (AA). The developed method has been applied to the determination of Ep and 5-HT in synthetic samples with satisfactory results.