Simultaneous Determination of Caffeine, Ibuprofen, and Paracetamol by Flow‐injection Analysis with Multiple‐pulse Amperometric Detection on Boron‐doped Diamond Electrode

Abstract

1IntroductionThem ost used methods for the determination of drugsi n pharmaceutical samples are basedo nh igh performance liquid chromatography (HPLC) using an UV detector. Despite of these methods being highly robust, in general they present some drawbacks such as high generation of waste and low analyticalf requencyf or routine analysis. Thee lectroanalytical techniques have shown to be an attractive alternativeness for the determination of drugs in pharmaceutical formulations.T he electroanalytical methods present high selectivity because most of active components in formulations are electroactive species while the excipients do not present any faradaic response.F urthermore,t he electrochemical detection providesh igh sensitivity,l ow-cost and fast analysis with less waste generation. Ar ecentr eview of Uslu and Ozkan has listed more than 200 pharmaceutical compounds that were determined by electrochemical detection [1].A notheri mportanta dvantage of electroanalytical methodsi st he possibility of simultaneous determinations of two or more associateda ctive ingredients in pharmaceutical formulations.T here are manys tudies reported in the literature using electrochemical techniques for simultaneous determinations by voltammetric detection on various types of workinge lectrodes [2][3][4][5][6][7][8].When electroanalytical methodsa re coupled to flow injection analysis (FIA), therea re even more advantages for the determination of electroactivec ompounds in comparison with voltammetric techniques using stationary detection mode.T he methods developed by FIA with electrochemical detection are faster and the passage of solution on the working electroder educes its surface fouling (or contamination) and increases the reproducibility of analyses.H owever, there are few studies in the literature using FIA systems with electrochemical detectionf or simultaneous determinations of drugs because the conventional amperometric detection mode (application of aconstant potential) is not selective.I nr ecenty ears,t he multiAbstract:T his work presents as imple,f ast and low-cost methodf or the simultaneous determination of three drugs by flow-injection analysis with multiple-pulse amperometric (MPA) detectionu sing aw all-jet flow cell with ab oron-doped diamond electrode.T he amperometric determination of caffeine (CF), ibuprofen (IB) and paracetamol (PC)w as performed by the application of af our-potential waveform using the MPAt echnique. PC is oxidized at E 1 (1.20 V/70 ms) and thus selectively detected;P Ca nd CF are oxidizeda tE 2 (1.49 V/40 ms);P C, CF and IB are oxidized at E 3 (1.70 V/70 ms);a nd E 4 (1.80 V/100 ms) is appliedf or electrode cleaning. The subtraction of currents obtaineda tt he differentp otentials did not provide accurated eterminations of CF and IB,t hus it was required to investigate correction factors to determine CF and IB without the interference from PC and CF usingt he respectivea mperometric signals obtained at E 2 and E 3 .T he proposed method was successfully appliedf or the determinatio...

Electroanalysis of Pharmaceuticals on Boron‐Doped Diamond Electrodes: A Review

“…Chaves and coauthors developed a flow‐injection analysis with multiple‐pulse amperometric methodology for PAR, CAF and IB detection . The authors used a 0.1 mol L −1 HNO 3 with 5 % (v/v) ethanol on BDD electrode (doping level of 8000 ppm).…”

Application of Flow-Injection Spectrophotometry to Pharmaceutical and Biomedical Analyses

“…Another example of combining FIA and an electrochemical system is found in the studies of Chaves et al [65] in which three compounds were determined simultaneously: caffeine, ibuprofen, and paracetamol. The authors report results obtained by combining FIA with multiple pulse amperometry (MPA) using a wall-jet flow cell with a boron-doped diamond electrode.…”

Size effects of multi-walled carbon nanotubes on the electrochemical oxidation of propionic acid derivative drugs: Ibuprofen and naproxen

“…Electroanalytical methods have been reported for the determination of IBF and NPX. The electrochemical oxidation of IBF was investigated at a boron-doped diamond electrode (BDDE) after anodic treatment and its oxidation occurred at around +1.7 V vs. Ag/AgCl (saturated KCl) using square-wave voltammetry [21] and amperometric detection in a flow-injection analysis (FIA) system [22]. NPX was detected on unmodified platinum [23], BDDE [24], glassy-carbon A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 4 electrodes [25], and on modified electrodes with dysprosium nanowires [26], carbon nanotubes (CNTs) [27,28] and the composite ZnO attached to CNTs [29].…”