Quantification of Terbutaline in Pharmaceutical Formulation and Human Serum by Adsorptive Stripping Voltammetry at a Glassy Carbon Electrode

Abstract

The electrochemical oxidative behavior of terbutaline at the glassy carbon electrode was studied in a series of the Britton-Robinson buffer of pH 2—11. Cyclic and square-wave voltammograms of terbutaline at the pH values ≤9 exhibited a single irreversible anodic peak. A fully validated, simple, sensitive and precise square-wave adsorptive anodic stripping voltammetric procedure was described for the determination of terbutaline in bulk form, tablets and human serum. For 5×10⁻⁸ M bulk terbutaline a mean recovery of 98.78±0.94% (n=5) was achieved following its preconcentration by adsorptive accumulation onto the glassy carbon electrode at a +0.15 V (vs. Ag/AgCl/KCl_s) for 180 s. Limit of detection of 6×10⁻⁹ M and limit of quantitation of 2×10⁻⁸ M terbutaline were achieved in the bulk form or its formulations (Bricanyl^® tablets). The described square-wave adsorption anodic stripping voltammetric procedure was successfully applied for the determination of terbutaline in human serum following medium exchange. Limit of detection of 1.41×10⁻⁸ M (3.173 ng ml⁻¹) and limit of quantitation of 4.70×10⁻⁸ M (10.575 ng ml⁻¹) were achieved in human serum with a mean recovery of 98.11±1.13%.