Determination of bromhexine at a glassy carbon paste electrode using differential pulse voltammetry and flow injection analysis with amperometric detection

New electrochemical methods for the determination of bromhexine based on differential pulse voltammetry (DPV) and flow injection analysis with amperometric detection (FIA-ED) were developed using a glassy carbon paste electrode. Optimal supporting electrolyte for DPV measurement was methanol/Britton-Robinson buffer pH 9 (80:20, v/v). In the case of FIA-ED, optimal conditions were as follows: detection potential +1.1 V, flow rate 1.0 cm³ min^-1, injected volume 0.1 cm³, and carrier solution methanol-ten times diluted B-R buffer of pH 9 (80:20, v/v). Detection limit was 2.0 × 10^-6 mol dm^-3 for DPV and 3.1 × 10^-7 mol dm^-3 for FIA-ED. The applicability of the newly developed methods was verified by the determination of bromhexine in pharmaceutical preparations (tablets of Bromhexin-EGIS and Bromhexin 8 BC). Graphical abstract: [Figure not available: see fulltext.]