Disposable Pencil Graphite Electrode for Ciprofloxacin Determination in Pharmaceutical Formulations by Square Wave Voltammetry

Abstract

In this work, a new electrochemical sensor based on pencil graphite with interesting features, such as low cost (US$ 0.01 per electrode), ease manufacture, and portability was developed. The sensor showed an adequate manufacturing reproducibility with RSD <5.3 %. Under this electrochemical platform, ciprofloxacin underwent an irreversible oxidation process at 1.03 V, characterized by the diffusion of electroactive species. A simple method by square wave voltammetry (SWV) has been optimized for the determination of ciprofloxacin in pharmaceutical formulations using a pencil graphite electrode (PGE). The method showed satisfactory analytical performance, with a wide linear range (12 to 55 μmol L−1), low detection limit (5.6 μmol L−1), adequate precision (RSD <3.2 %), and accuracy with an average recovery of (102±15)%. Samples of pharmaceutical formulations were evaluated, obtaining levels of ciprofloxacin close to those established by the manufacturers. In addition, the samples were analyzed by liquid chromatography and there was no significant difference between the methods at the 95 % confidence level. In this sense, the method developed proved to be reliable and promising for the quality control of pharmaceutical formulations.

Rapid Voltammetric Screening Method for the Assessment of Bioflavonoid Content Using the Disposable Bare Pencil Graphite Electrode

“…The HESP higher oxidation signal (a2, with the peak potential E pa2 ~0.710 V) was used. The enhanced sensitivities obtained at PGEs vs. the GCE can be attributed to the rougher PGE surface in comparison to that of the GCE [37]. According to the results shown in Table 1, the best sensitivity was also achieved at the H type PGE and therefore, this electrode was used in all the further voltammetric investigations of HESP.…”

Recent Developments in Voltammetric Analysis of Pharmaceuticals Using Disposable Pencil Graphite Electrodes

“…Electrical contact with the instrument is realized by means of a conductive wire which was soldered or wrapped to the metallic part of the mechanical pencil holder [9,19,21,22,[24][25][26][27][28][29][30][31][32][33][34][35][36][37] (Figure 1a). A micropipette tip [38], an insuline syringe [39], a glass cappilary [40,41], or a plastic [16,[42][43][44][45][46] (Figure 1b) or Teflon tube [47][48][49][50][51][52] (Figure 1c,d) can also act as holder. An araldite mixture (epoxy resin, 1:1) [16,41,[43][44][45], bentonite [38,39], or cyanoacrylate glue [40] was used to fix the graphite lead into the support.…”

Graphene nanosheet-sandwiched platinum nanoparticles deposited on a graphite pencil electrode as an ultrasensitive sensor for dopamine

“…38,39 Due to its unique features, the graphite pencil electrode is emerging as a powerful sensing tool. 40,41 In this work, the graphite pencil electrode's sensitivity and selectivity improved by using the PtNPs based sandwich structure presented with an upper and a lower layer of reduced graphene oxide (GR). The specic arrangement of the new nanocomposite formed between PtNPs and graphene oxide on GPE has signicantly improved the limit of quantitation to 6.0 Â 10 À2 mM and the detection limit of dopamine to 9.0 Â 10 À3 mM, compared to the previously stated Pt-based graphene composite.…”