Search

Here, the hierarchical mesoporous-activated carbon particles obtained by KOH activation from pistachio shell wastes are modified by both the sulfonation process and CuO doping by hydrothermal heating (CuO@S-doped PSAC) for use as a supercapacitor. It is predicted that the electrochemical performance of the porous carbon electrode material obtained by such CuO doping and sulfonation process will be significantly increased with increased Faradaic capacitance. The electrochemical performance of CuO@S doped PSAC composite is systematically investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge/discharge (GCD) in the presence of 1 M H 2 SO 4 , 1 M Na 2 SO 4 , and 1 M NaOH as electrolytes. The CuO@S doped PSAC-based electrode shows excellent stability with high specific capacitance up to 397.16 F/g at 0.1 A/g and 92.64% retention. Furthermore, FTIR, SEM, XRD, EDS, and nitrogen adsorption/desorption analyses are used for the characterisation of the obtained composites. Based on a significant supercapacitor performance, the synthesis strategy of carbon-based electrode material containing sulfonation and CuO modifications derived from agricultural biomass waste material is predicted to be a valuable example., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: Nivolumab is used in a treatment called immunotherapy, which helps the immune system cells to attack cancer cells. The electrochemical properties and quantification of this drug were performed using single-use pencil tips., Evidence Acquisition: Here, a selective voltammetric method for the determination and electrochemical characterization of Nivolumab used in cancer therapy was developed for the first time using a disposable pencil electrode by cyclic voltammetry and differential pulse voltammetry techniques. Nivolumab exhibited an anodic signal at +0.879 V (vs. Ag/AgCl) in PBS (pH 3.0, 0.02 M NaCl) medium., Results: This procedure showed a linear response in phosphate buffer solutions (pH 3.0, 0.02 M NaCl) media within the concentration range of 0.01 mg mL -1 to 0.07 mg mL -1 and limit of detection and the limit of quantification values were determined to be 2.49 μg mL -1 and 8.30 μg mL -1 , respectively., Conclusions: The developed method offers an important analytical approach for the detection and characterization of NIVO. Precisely measuring and monitoring the levels of such drugs in real sample analyses or biological samples is critical for evaluating response to treatment, optimizing treatment strategies. Therefore, the method was applied to real sample analyses. Voltammetric results developed using PG electrode were compared with UV-Vis results. It has been determined that the results obtained are compatible with each other., (© 2023. The Author(s), under exclusive licence to Tehran University of Medical Sciences.)

Objectives The anticoagulant drug edoxaban has a blood thinning mechanism of action. In this study, a pencil graphite electrode was electrochemically activated at + 1.4 V for 60 s. in a Britton-Robinson (pH 9.0) supporting electrolyte solution. Evidence acquisition A simple, fast, and sensitive electrochemical procedure was developed using cyclic voltammetry and square wave voltammetry techniques. It was observed that edoxaban gave a good oxidation signal with cyclic voltammetry technique at a potential of + 0.98 V (vs. Ag/AgCl). Results This procedure showed a linear response in a Britton-Robinson (pH 9.0) media within the concentration range of 0.2--1.8 µM and limit of detection (LOD) and the limit of quantification (LOQ) values were determined to be 0.073 μM (0.133 μg mL1) and 0.243 μM (0.443 μg mL-1), respectively. Conclusion The method developed in this study was successfully applied to drug and urine samples. The developed voltammetric method was highly selective and gave satisfactory recovery results in urine and pharmaceutical samples. The results of the voltammetric method were compared with the spectroscopic method and it was determined that the results were compatible. [ABSTRACT FROM AUTHOR]

In this study, the electrochemical properties of desloratadine, which is in the second generation antihistamines group, were determined by bismuth film electrode (BiFE) in aqueous and aqueous/surfactant solutions. This compound gave an irreversible and diffusion-controlled reduction peak at about -1.65 V by cyclic voltammetry. It was found that the addition of cationic surfactants (cetyltrimethylammonium bromide (CTAB) increased the reduction current signal of desloratadine, while anionic (sodium dodecylsulfate (SDS) and nonionic (Tween 80) surfactants were found to have an adverse effect. Using linear sweep-cathodic stripping voltammetry, the analytical signal showed a linear correlation with a concentration of 0.1 to 4 µM in 0.04 M Britton-Robinson solution (pH = 8.0) in the presence of 5 mM CTAB, while the detection limit was calculated to be 11.70 nM (3.64 µgL-1). This method has been successfully applied for the quantitation of desloratadine in pharmaceutical and urine samples without the need for any separation. [ABSTRACT FROM AUTHOR]

A pencil graphite electrode (PGE) was used for the simultaneous detection of ascorbic acid (AA), norepinephrine (NE), and uric acid (UA) by differential pulse voltammetry and cyclic voltammetry. The anodic peaks of AA, NE, and UA in their mixture can be well separated in 0.1 M Britton{Robinson buffer solution at pH 4.0. The effects of various experimental parameters such as pH, scan rate, and voltammetric parameters on the voltammetric response of these compounds were investigated. Under optimum conditions, linear calibration graphs were obtained from the AA, NE, and UA concentration ranges, which were 100{800 nM, 20{170 nM, and 40{175 nM, respectively. The detection limits for AA, NE, and UA were 27 nM, 4 nM, and 10 nM in the form of a mixture at the PGE. This electrode shows great analytical performance characteristics, corresponding repeatability and recovery for the simultaneous determination of these compounds. PGE, which was used for the first time in this method, has been successfully applied for the assay of UA in human urine samples with the aim of determining AA and NE in pharmaceutical drugs. [ABSTRACT FROM AUTHOR]

In this work, an electrochemical investigation of acebutolol (ACE), a beta-blocker drug, was carried out in alkaline medium using pencil graphite (PG) electrode. In cyclic voltammetry, the compound displayed a reversible and adsorption-controlled oxidation peak. By using square-wave anodic stripping voltammetry, the oxidation peak current observed at +0.78 V showed a linear relationship with concentration at 0.4-7 nM interval in Britton-Robinson buffer (pH 10.0) and a detection limit of 0.09 nM. The relative standard deviation of 4.72% for the concentration level of 2.0 nM ( n = 11) was also calculated. The PG electrode that is used for the first time in this method was successfully applied to determine the ACE in pharmaceutical formulations and urine. [ABSTRACT FROM AUTHOR]

Abstract: Benzo[a]pyrene (BaP), a member of the polycyclic aromatic hydrocarbon (PAH) class, is one of the most potent PAH carcinogens. The electrochemical oxidation of BaP was first studied by cyclic voltammetry at the boron-doped diamond electrode in non-aqueous solvent (dimethylsulphoxide with lithium perchlorate). The compound was irreversibly oxidized in a single step at high positive potential, resulting in the well-resolved formation of a couple with a reduction and re-oxidation wave at much lower potentials. Special attention was given to the use of adsorptive stripping voltammetry together with a medium exchange procedure in aqueous and aqueous/surfactant solutions over the pH range of 2.0–8.0. The technique in aqueous solutions had little value in practice because of too small oxidation peak current. This problem was solved when surfactants were added into the sample solution, by which the oxidation peak currents of BaP were found enhanced dramatically. The employed surfactants were sodium dodecylsulfate (anionic, SDS), cetyltrimethylammonium bromide (cationic, CTAB) and Tween 80 (non-ionic). Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in Britton–Robinson buffer, pH 2.0 containing 2.5×10−4 M SDS at +1.07V (vs. Ag/AgCl) (after 120s accumulation at +0.10V). The process could be used to determine BaP in the concentration range of 16–200nM (4.04–50.46ngmL−1), with a detection limit of 2.86nM (0.72ngmL−1). This method was also applied to determine BaP in model water sample prepared by adding its different concentrations into tap water. [Copyright &y& Elsevier]

The electrochemical properties of thiourea (TU) were investigated in pH range 2.0-12.0 by cyclic and square-wave voltammetry. The compound was irreversibly oxidized at a pencil graphite electrode in one or two oxidation steps which are pH-dependent. Based on the voltammetric peak for the second oxidation process of TU in phosphate buffer at pH 12.0, a square-wave voltammetric method was proposed for the determination of the compound in the range 6.3-30μ m, with a detection limit of 1.29μ m. The applicability to direct assays of wastewaters was also tested. [ABSTRACT FROM AUTHOR]

Abstract: The electrochemical oxidation of nicotine was studied in aqueous as well as micellar media at a pencil graphite electrode using cyclic, differential pulse and square-wave voltammetric techniques. The compound was oxidized irreversibly at low positive potentials in one (in acidic and neutral media) or two (in alkaline media) oxidation steps. The response was evaluated with respect to pH, scan rate, addition of surfactant and other variables. For analytical purposes, very resolved voltammetric peaks at +0.84V (versus Ag/AgCl) were obtained in phosphate buffer at pH 7.0 containing 2mM sodium dodecylsulfate using square-wave mode. The process could be used to determine nicotine concentrations in the range of 7.6–107.5μM with a detection limit of 2.0μM (0.33mgL−1). The proposed method was applied to the determination of nicotine in different brands of commercial cigarettes. [Copyright &y& Elsevier]

In this study, electrochemical properties of progesterone at boron doped diamond (BDD) electrode surface were examined in strongly acidic medium (HClO 4 and H 2 SO 4). A fast, sensitive, selective and simple electroanalytic method has been proposed with a cathodically pre-treated (CPT-BDD) electrode in 0.5 M H 2 SO 4 medium. Progesterone yielded a well-defined voltammetric response in 0.5 M H 2 SO 4 medium at +1.51 V (vs. Ag/AgCl). Using the optimal square wave-adsorptive stripping voltammetry (SW-AdSV) conditions, the oxidation peak was used to determine of progesterone in the concentration range of 0.1 to 7.1 μM. Limit of detection is 0.012 μM; the relative standard deviation value for the concentration value of 3.1 μM (n = 11) was calculated as 4.87%. The developed voltammetric method was successfully applied to serum and drug samples. [Display omitted] • CPT-BDD electrode was employed for the first time for determination of progesterone. • Benefits of method: rapidity, simplicity, sensitivity and repeatability • The procedure was successfully applied to progesterone detection in drug form and serum. [ABSTRACT FROM AUTHOR]

In this study, the highly risky drug Edoxaban (EDX), which can threaten life and cause bleeding, was electro analytically evaluated. The electrochemical behavior of EDX was investigated using glassy carbon electrode (GCE) and boron-doped diamond electrode (BDDE). In this study, for the first time, a simple, rapid, sensitive, and selective voltammetric technique was developed by using different electrodes for the electrochemical characterization and detection of EDX. The optimized voltammetric technique showed anodic signals of EDX at +1.09 V and +1.08 V on GCE and BDDE, respectively, in BR (pH 5.0) solution. The developed voltammetric method provided a very good analytical working range for EDX in BR (pH 5.0) solution on GCE and BDDE, covering concentration ranges from 1.84 μM to 12.88 μM and from 3.68 μM to 14.72 μM, respectively. The limits of detection for EDX on GCE and BDDE under these experimental conditions were calculated as 0.24 μM and 0.57 μM, respectively. The developed voltammetric methods on both electrodes were successfully applied to urine and tablet samples. Additionally, the obtained voltammetric results were compared with UV–Vis spectroscopy results. [Display omitted] • Application of glassy carbon and boron-doped diamond electrodes for the determination and electrochemical properties of edoxban for the first time. • Benefits of voltammetrc method: eco-friendliness, rapidity and simplicity. • Comparable method with spectrophotometric detection. • The procedure was successfully applied to edoxaban detection in pharmaceutical and urine samples. [ABSTRACT FROM AUTHOR]

In this study, the electrochemical properties of etofenamate, an active ingredient belonging to the non-steroidal anti-inflammatory drug group, were investigated using cyclic voltammetry (CV) and square wave voltammetry (SW) techniques on a disposable pencil graphite electrode (PGE). With the CV technique, reversible voltammetric waves of around +0.470 V and irreversible voltammetric waves of around +1.02 V were produced on the PGE. An environmentally friendly, selective and highly sensitive SW voltammetric method was developed using disposable PGE. This voltammetric method gave very good analytical working range on PGE in PBS (pH = 3.0) medium at concentrations ranging from 0.017 μM to 0.306 μM. The LOD value of this analytical method in PBS (pH = 3.0) medium was calculated as 0.0011 μM (0.406 μg L−1). The developed voltammetric method was successfully applied to urine and drug samples. The results of the voltammetric method were compared with the results of the spectrophotometric method. The results were found to be compatible with each other. [Display omitted] • Pencil graphite electrode was employed for the first time for determination of Etofenamate. • Benefits of method: rapidity, simplicity, sensitivity and repeatability. • The procedure was successfully applied to determination of Etofenamate urine and drug samples. [ABSTRACT FROM AUTHOR]