Determination of prazosin in pharmaceutical samples by flow injection analysis with multiple-pulse amperometric detection using boron-doped diamond electrode

• Published in: Journal of solid state electrochemistry Vol. 20; no. 9; pp. 2445 - 2451
• Main Authors: Guedes, Tiago de Jesus, Alecrim, Morgana F., Oliveira, Fernando M., Lima, Amanda B., Barbosa, Sandro L., dos Santos, Wallans T. P.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2016; Springer Nature B.V
• Subjects: Analytical Chemistry; Boron; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography; Condensed Matter Physics; Diamond films; Electrical measurement; Electrochemical analysis; Electrochemistry; Energy Storage; Flow injection analysis; Flow velocity; Frequency analysis; Original Paper; Oxidation; Pharmaceuticals; Physical Chemistry; Silver chloride; Waveforms; Prazosin; Multiple-pulse amperometry; Flow injection analysis; Pharmaceutical analysis; Boron-doped diamond
• ISSN: 1432-8488; 1433-0768
• DOI: 10.1007/s10008-015-3105-3

This work describes the development of a simple, fast and low-cost method for determining prazosin (PRA) in pharmaceutical samples by flow injection analysis with multiple-pulse amperometric (FIA-MPA) detection using a boron-doped diamond film electrode. Electrochemical detection of PRA was optimized in phosphate buffer pH 4.0 by cyclic voltammetry, in which PRA presented two oxidation processes around at 0.97 and 1.40 V versus Ag/AgCl (3.0 mol L −1 KCl). In these conditions, PRA also showed one reduction process at −0.75 V that is dependent on the oxidation processes. Thus, the determination of PRA by FIA-MPA detection consisted on the application of a two-potential waveform, E 1 (generator potential) = 1.6 V/400 ms and E 2 (collector potential) = −1.0 V/30 ms, with sample loop of 150 μL and flow rate of 3.0 mL min −1 . The method showed good repeatability (RSD < 3.0 %) and high analytical frequency (70 injections per h ). The working linear range was obtained from 2 to 200 μmol L −1 with a limit of detection of 0.5 μmol L −1 . The recovery tests in all samples were approximately 100 %, and the results were compared with chromatographic methods.