Voltammetric and flow injection-based determination of propranolol using an electrochemically treated pencil graphite...

A versatile electroanalytical platform was developed for the determination of propranolol (PROP) using an electrochemically pre-treated pencil graphite electrode (ET/PGE). Instead of relying on complex chemical modification, a simple electrochemical pre-treatment was employed as an effective surface engineering strategy, enabling rapid electrode preparation, good reproducibility, and direct integration into multiple analytical configurations. In the first stage, the ET/PGE was applied for voltammetric determination of PROP, exhibiting two linear working ranges (0.1-2.5 µM and 5-25 µM). The system was subsequently extended to a flow injection analysis configuration with amperometric detection (A-FIA) using a homemade electrochemical cell, significantly expanding the linear range to 0.5-75 µM. In the final stage, chromatographic separation was incorporated by integrating a C₁₈ column, resulting in an A-FIA/HPLC configuration with enhanced selectivity and a further extended linear range of 0.5-125 µM. The applicability of the proposed method was demonstrated in pharmaceutical formulations and synthetic urine samples, yielding satisfactory recovery values (98.80-100.46% and 101.26-108.04%, respectively). Overall, the proposed strategy enables the use of a single electrode in multiple analytical configurations, providing flexibility in sensitivity, linear range, and selectivity. This integrated strategy offers practical advantages in terms of simplicity, cost-effectiveness, and adaptability compared to conventional single-configuration electrochemical methods.