A simple and fast batch injection analysis method for simultaneous determination of phenazopyridine, sulfamethoxazole, and trimethoprim on boron-doped diamond electrode

•First electrochemical method for simultaneous determination of SMX, TMP and FZP.•Determination of three species with a single-injection step (in less than 1 min).•BIA-MPA system and BDD electrode was used in this study.•The proposed method is fast, simple, cost-effective and environmentally friendly.

A new analytical procedure for fast and simultaneous determination of sulfamethoxazole (SMX), trimethoprim (TMP) and phenazopyridine (FZP) has been developed. The method is based on batch injection analysis with multiple pulse amperometric detection (BIA-MPA) which offers several desirable features, such as simplicity, reduced costs, robustness, good precision (RSD < 3.5%, n = 15), high analytical frequency (up to 70 injections h− 1) and generation of small volume of waste by analysis. The BIA-MPA procedure provides linear range from 4 to 320, from 2 to 40 and from 1 to 40 mg L− 1 and limits of detection of 0.20, 0.15 and 0.05 mg L− 1 for SMX, TMP and FZP, respectively. The results obtained with the proposed method were compared to those obtained by HPLC and similar results were obtained (95% confidence level).

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