First Approach for the Voltammetric Sensing of Rifabutin by the Use of Cationic Surfactant Media on the Boron-Doped Diamond Electrode

Abstract

An excellent electrochemical sensor for determining rifabutin (RFB) by square-wave voltammetry was developed utilizing a non-modified boron-doped diamond electrode. Measurements of RFB using cyclic voltammetry with Britton-Robinson buffer (BR, 0.04 M, pH 7.0) solution revealed irreversible behaviour, diffusion-controlled as well as well-defined two oxidation peaks at around +0.67 (PA1) and + 1.23 (PA2) V vs Ag/AgCl. RFB oxidations depend critically on pH and supporting electrolytes. The anodic peak currents of the RFB were enormously enhanced by adding cetyltrimethylammonium bromide (CTAB, cationic surfactant) in the chosen supporting electrolyte, mainly when accumulating conditions were utilized. RFB was quantified using its two anodic peaks. By using optimized procedures also instrumental variables, the current response via RFB is proportionally linear throughout the concentration range of 0.1 to 10.0 mu g mL-1 (1.18 x 10-7-1.18 x 10-5 M) via a detection limit of 0.030 mu g mL-1 (3.54 x 10-8 M) for PA1 and 0.026 mu g mL-1 (3.07 x 10-8 M) for PA2 in BR buffer (PH 7.0) solution. Ultimately, the proposed approach was accurately utilized to evaluate RFB in pharmaceutical formu-lation. To the greatest of our knowledge, this is the first approach for electroanalytical determination of RFB.