Simple and Fast Determination of Warfarin in Pharmaceutical Samples Using Boron‐doped Diamond Electrode in BIA and FIA Systems with Multiple Pulse Amperometric Detection

Abstract

This paper proposes the use of the boron‐doped diamond electrode (BDDE) in flow and batch injection analysis (FIA and BIA) systems with multiple‐pulse amperometric (MPA) detection for the determination of warfarin (WA) in pharmaceutical formulations. The electrochemical behavior of WA obtained by cyclic voltammetry (CV) in 0.1 mol L−1 phosphate buffer shows an irreversible oxidation process at +1.0 V (vs Ag/AgCl). The MPA was based on the application of two sequential potential pulses as a function of time on BDDE: (1) for WA detection at +1.2 V/100 ms and; (2) for electrode surface cleaning at −0.2 V/200 ms. Both hydrodynamic systems (FIA‐MPA and BIA‐MPA) used for WA determination achieved high precision (with relative standard deviations around 2 %, n=10), wide linear range (2.0−400.0 μmol L−1), low limits of detection (0.5 μmol L−1) and good analytical frequency (94 h−1 for FIA and 130 h−1 for BIA). The WA determination made by the proposed methods was compared to the official spectrophotometric method. The FIA‐MPA and BIA‐MPA methods are simple and fast, being an attractive option for WA routine analysis in pharmaceutical industries.

Boron Doped Diamond Electrodes in Flow-Based Systems

“…It is worth mention that all works employed a cathodically pretreated BDD electrode. FIA systems with pulsed amperometric detection (similar to MPA) using BDD as working electrode were also used for the determination of a single species in pharmaceutical formulations, as demonstrated for salbutamol, terbutaline, and clenbuterol (Karuwan et al, 2006), diclofenac (Gimenes et al, 2011), sildenafil citrate (Lopes Júnior et al, 2012), cotinine (Alecrim et al, 2016), prazosin (Guedes et al, 2016), warfarin (de Jesus Guedes et al, 2017), colchicine (Moreira et al, 2018), verapamil (Barbosa Lima et al, 2018), and oxcarbazepine (Lima et al, 2018). Colchicine, verapamil, and oxcarbazepine were also determined in biological fluids.…”

Boron doped diamond electrode in analytical chemistry: methods of electrode surface activation (а short review)

“…Проте збільшення кількості бору може звузити робочий діапазон потенціалів і зменшити стабільність матеріалу [1,50,52]. Беручи до уваги ці чинники, можна підібрати оптимальний рівень легування бором для конкретного аналізу, однак найчастіше використовують АДБЕ з умістом бору 8 000 ppm, які забезпечують високу провідність, достатньо високий і чіткий аналітичний сигнал та широкий діапазон потенціалів [5,48].…”

Next-Generation Diamond Electrodes for Neurochemical Sensing: Challenges and Opportunities

“…With this in mind, an optimum boron doping concentration and sp 3 /sp 2 ratio can be selected for any particular electroanalytical sensing application, taking into consideration the specific sensitivity, potential window, and material stability requirements. For example, in small molecule sensing where high sensitivities are required, a boron concentration of ~8000 ppm is commonly used [ 209 , 210 , 211 , 212 , 213 , 214 , 215 , 216 , 217 , 218 , 219 , 220 , 221 , 222 , 223 , 224 ]. This mid- to high-doping concentration yields a material with high conductivity and moderate sp 2 impurities compared to heavily doped BDD [ 112 ].…”