Stripping voltammetric determination of manganese in bioethanol

In this work, we describe the first electroanalytical method for manganese (Mn (II) determination in bioethanol based on square-wave cathodic stripping voltammetry (SWCSV) at a bare glassy-carbon electrode. Bioethanol is directly diluted in a Britton-Robinson buffer solution (pH 4.0) and a stripping peak for Mn(II) is attained at approximately 0.9 V (vs. Ag/AgCl). After optimizing SWCSV parameters (deposition potential and time, stirring speed, amplitude, frequency and step potential), the proposed method presented low relative standard deviation between injections (5.6%, n = 10), low detection limit (16 μg L− 1) for a 300 s deposition time and 40-fold dilution, a linear range between 3 and 175 μg L− 1, and adequate recovery values (90-110%) in fortified samples.