The Determination of indacaterol at the surface of the boron-doped diamond electrode in inhaler capsules by using square-wave voltammetry

Abstract

This research paper presents an electroanalytical investigation using the voltammetric method to quantify indacaterol maleate (IND) employing an unmodified boron-doped diamond (BDD) electrode. IND exhibited a distinct, irreversible oxidation peak at approximately + 1.06V (vs. Ag/AgCl) in a 0.1 mol L^-1 phosphate buffer solution (PBS) with a pH of 2.5, as demonstrated by cyclic voltammetry (CV). A hypothetical mechanism for the electro-oxidation of IND was suggested based on data gathered from CV investigations. The square wave-adsorptive stripping voltammetric technique achieved acceptable linearity in PBS (pH 2.5) at approximately +0.90 V. The methodology demonstrated linearity within the concentration range of 1.0 to 30.0 μg mL^-1 (equivalent to 1.97x10^-6-5.89x10^-5 mol L^-1) and yielded a limit of detection (LOD) of 0.22 μg mL^-1 (equivalent to 4.33x10^-7 mol L^-1). The proposed method's applicability was assessed through the sensing of IND in drug formulations.