Analytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231Simultaneous Determination of Caffeine, Theobromine, and Theophylline in Tea by Differential Pulse Adsorptive Stripping Voltammetry Combined with Chemometrics1046105971940710.22034/abec.2024.719407ENThuong Thi KimNguyenDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamTuan AnnhPhamDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamThu HuyenLuuDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamThi Huong GiangLeDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamHuy HoangDoDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamMinh Huong GiangDangDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamThi ThaoTaDepartment of Analytical Chemistry, Faculty of Chemistry, University of Science, Vietnam National University, Hanoi, VietnamJournal Article20240723Adsorptive stripping voltammetry (AdSV) using a glassy carbon electrode combined with chemometrics was investigated for simultaneous determination of caffeine, theobromine, and theophylline in tea samples, offering high selectivity, sensitivity, simplicity, and cost-effectiveness. The optimal electrochemical conditions were 0.01 mol.L<sup>-1</sup> H<sub>2</sub>SO<sub>4</sub>, an adsorption potential of 0.6V <em>vs.</em> Ag/AgCl/KCl, a scan rate of 0.025 V/s, and an adsorption time of 60 s. Linear calibration graphs for each compound were obtained in the concentration ranges from 1.0×10<sup>-6</sup> to 4.0×10<sup>-5</sup> mol.L<sup>-1</sup>, 1.0×10<sup>-6</sup> to 3.0×10<sup>-5</sup> mol.L<sup>-1</sup>, and 1.0×10<sup>-6</sup> to 1.4×10<sup>-5</sup> mol.<br />L<sup>-1</sup> for caffeine, theobromine, theophylline, respectively. In this study, a pre-separation step was not required despite the overlapping voltammetric peaks of caffeine, theobromine, and theophylline in the mixtures, as chemometrics techniques, such as partial least squares (PLS), principal component regression (PCR), and classical least squares (CLS) were applied. Among the three multivariate linear regressions, the PLS method was chosen because it has the smallest relative error, all less than ±11.1%. In contrast, the CLS performed poorly with relative reaching up to ±83%. The proposed novel method was applied to simultaneously determine caffeine, theobromine and theophylline in tea samples. The results showed no significant differences compared to those obtained using high-performance liquid chromatography (HPLC).https://www.abechem.com/article_719407_bfd3d169c006984abfdf820903de344b.pdfAnalytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231Fabrication of Thiazole Based Heterocyclic Azo Dye Modified Carbon Paste Electrode for Detection of Dopamine: A Voltammetric Study1060107171940810.22034/abec.2024.719408ENKusuma HPaalaplaraDepartment of Studies in Chemistry, Davangere University, Shivagangotri, Davangere-577007 Karnataka, India0009-0003-2232-3556Keerthi Kumar TChinnagiriDepartment of Studies in Chemistry, Davangere University, Shivagangotri, Davangere-577007 Karnataka, India0000-0002-3184-8368Ramya Kumari TChinnagiriDepartment of Chemistry, D R M Science College, Davangere-577002, Karnataka, IndiaRaghavendra MThippandegowdruDepartment of Studies in Chemistry, Davangere University, Shivagangotri, Davangere-577007 Karnataka, India0009-0001-7064-8932Journal Article20240829A 5-[(4-phenyl-1, 3-thiazol-2yl) diazenyl] 1,3diazinane 2, 4,6trione (PTDDT) was synthesized from 2-amine-4-phenylethioazole. The synthesized PTDDT was characterized through using mass, UV-Visible, <sup>1</sup>H NMR, <sup>13</sup>C NMR, elemental analysis and FT-IR. Characterized PTDDT used as a modifier for carbon paste electrode (CPE) and was used for voltammetric detection of dopamine (DA) and uric acid (UA) using phosphate buffer solution (PBS) at pH 6.6. Many different parameters were studied such as sweep rate, varied concentration, pH study. The limit of detection is 1.056 µM for DA and 0.080 µM for UA with a limit of quantification 3.521 µM for DA and 0.267 µM for UA at PTDDT/MCPE, and it also shows good repeatability and satisfactory recovery result on real samples.https://www.abechem.com/article_719408_9760ac205359c1c0b0c3180df3f49ff6.pdfAnalytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231Corrosion Inhibition Effect of Expired Fluticasone Propionate on API 5L Grade B Steel in A Sodium Chloride Medium1072108471940910.22034/abec.2024.719409ENSihemKherrafLaboratory of Chemical Engineering and Environment of Skikda, University of 20 August 1955-Skikda, AlgeriaDepartement of Petrochemicals, Faculty of Technology, University of 20 August 1955-Skikda, Skikda, Algeria0000-0002-6455-2571ZohraDjetouiDepartement of Petrochemicals, Faculty of Technology, University of 20 August 1955-Skikda, Skikda, Algeria0009-0009-3420-8276MalikaFoudiaLaboratory of Energy and Electrochemistry of Solids, Faculty of Technology, Ferhat Abbas University Setif-1, Setif 19000, AlgeriaJournal Article20240917Fluticasone propionate, a steroid medication commonly used to treat asthma and allergic rhinitis, was evaluated for its potential as a corrosion inhibitor for API 5L Grade B steel in a 3.5% sodium chloride medium. The experimental techniques employed included the gravimetric method, potentiodynamic polarization, electrochemical impedance spectroscopy measurements, and surface analysis. The results demonstrated that fluticasone propionate is an effective corrosion inhibitor, with inhibition efficiencies of 90.10%, 91.86%, and 92.91% as determined by the weight loss method, polarization studies, and the electrochemical impedance spectroscopy technique, respectively. As the inhibitor concentration was increased in the corrosive solution, the charge transfer resistance also increased, due to the growing thickness of the electrical double layer. Polarization data indicated that the drug acted as a mixed-type inhibitor. Adsorption studies confirmed that the adsorption process was spontaneous and involved a physisorption mechanism: adsorption of the drug compounds onto the metal surface followed the Langmuir adsorption isotherm model. An increase in the electrolyte temperature led to a decrease in the inhibition efficiency from 90.10% to 72.45%. A thermodynamic analysis revealed that the addition of the inhibitor led to an increase in the activation energy of the test solution from 6.06 kJ.mol<sup>-1</sup> to 31.04 kJ.mol<sup>-1</sup>, thus confirming the formation of a protective layer that reduced the kinetics of the corrosion reactions. Surface analysis revealed that the inhibited sample showed less deterioration compared to the uninhibited one.https://www.abechem.com/article_719409_9107d1b2354e87bedfcda54231785ea3.pdfAnalytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231Octylamine Assisted Hydrothermal Growth of Silver Selenide Nanospheres as Efficient Electrode Material for Energy Storage Application1085109771941010.22034/abec.2024.719410ENSanghamitraMohapatraP.G. Department of Physics, Berhampur University, Odisha, Pin:760007, IndiaTapan KumarSarangiP.G. Department of Physics, Berhampur University, Odisha, Pin:760007, India0009-0009-8595-7680Kusha KumarNaikP.G. Department of Physics, Berhampur University, Odisha, Pin:760007, IndiaJournal Article20241030This study explores the electrochemical storage potential of Ag₂Se nanosphere electrode material synthesized via a hydrothermal method, demonstrating their applicability in supercapacitors. Comprehensive structural, morphological, and optical analyses were conducted using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectroscopy, confirming the formation of Ag₂Se nanospheres. Supercapacitive performance was assessed through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a three-electrode configuration using KOH as the electrolyte. The Ag₂Se nanospheres exhibited high pseudocapacitive behavior, delivering a specific capacitance of 437.5 F/g, an energy density of 29.5 Wh/kg, and a power density of 89.32 W/kg, positioning them as effective energy storage materials. Notably, the nanospheres displayed remarkable cyclic stability, retaining 90% of their capacitance after 100 cycles, underscoring their durability for long-term applications. These findings suggest that Ag₂Se nanospheres offer a promising balance between high performance and cyclic stability, making them suitable candidates for advanced supercapacitor applications.https://www.abechem.com/article_719410_e8f15cb443282218aefd7634720b7a08.pdfAnalytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231A New Sensor Electrode for Caffeine Determination Using Square Wave Voltammetry: Cytosine Modified Glassy Carbon Electrode1098110871941310.22034/abec.2024.719413ENŞeymaKorkmazNecmettin Erbakan University, Institute of Science, Chemistry Department, Konya, Turkey0000-0002-5445-7239AyselAlovset RustemovaNecmettin Erbakan University, Institute of Science, Chemistry Department, Konya, TurkeyAzerbaijan State Agricultural University, AzerbaijanShabnam JamaladdinAliyevaNecmettin Erbakan University, Institute of Science, Chemistry Department, Konya, TurkeyAzerbaijan State Agricultural University, AzerbaijanHafizullahSharifiNecmettin Erbakan University, Institute of Science, Chemistry Department, Konya, Turkey0000-0002-9317-5461İbrahim EnderMülazımoğluNecmettin Erbakan University, Ahmet Keleşoğlu Education Faculty, Chemistry Department, Konya, Turkey0000-0003-1676-2870AyşenDemir MülazımoğluNecmettin Erbakan University, Ahmet Keleşoğlu Education Faculty, Chemistry Department, Konya, Turkey0000-0001-5780-3056Journal Article20241112In this study, cytosine (CT) modified glassy carbon (GC) electrode was used to investigate the detectability of caffeine (CAF) found in foods such as tea, coffee and soft drinks. Using the cyclic voltammetry (CV) technique, 1 mM CT was prepared in pH 7.2 phosphate buffer solution (PBS) and modified at a scanning rate of 100 mV s<sup>-</sup>¹ in the potential range of 1.0 V to 2.1 V. CT/GC electrode was characterized by CV, scanning electron microscope (SEM) and electrochemical impedance spectroscopy (EIS) techniques. 1 mM CAF solutions were prepared in different supporting electrolytes such as H₂SO₄, HCl, HNO₃, and CH₃COOH within the potential range of +0.5 V to +1.7 V using square wave voltammetry (SWV) technique. Effect of the supporting electrolyte concentrations were investigated. CAF solutions in the concentration ranges of 0.75 to 0.05 mM and 0.025 to 0.0025 mM were prepared in 100 mM H₂SO₄ supporting electrolyte and calibration graphs were drawn. Line equations were created using the values read from the drawn graphs. Correlation coefficient (R<sup>2</sup>) values were calculated as 0.9947 and 0.9961, respectively. Using the calibration curves, limit of detection (LOD) and limit of quantification (LOQ) were found as 0.93 µM and 2.79 µM.https://www.abechem.com/article_719413_ddd1608138fe8f9467720a09136bca93.pdfAnalytical and Bioanalytical Electrochemistry is an international scientific journal, which is published online every 3 months (since 2009), every 2 months (since 2011) and monthly (since 2018) by Center of Excellence in Electrochemistry, University of TehranAnalytical and Bioanalytical Electrochemistry-161220241231Synergistically Enhanced Electrocatalytic Performance of Mn-Co-Ni Oxides/rGO Composite for Efficient Oxygen and Hydrogen Evolution Reactions1109112171941610.22034/abec.2024.719416ENMehdiMehrpooyaSchool of Energy Engineering and Sustainable Resources, College of Interdisciplinary Science and Technology, University of Tehran, Tehran, IranHydrogen and Fuel Cell Laboratory, University of Tehran, Tehran, IranSinaHosseiniSchool of Energy Engineering and Sustainable Resources, College of Interdisciplinary Science and Technology, University of Tehran, Tehran, IranHydrogen and Fuel Cell Laboratory, University of Tehran, Tehran, IranJournal Article20241105This study presents the development of a highly efficient NiCoMn@N,Co-rGO electrocatalyst designed to facilitate electrochemical water electrolysis, specifically addressing both the Oxygen Evolution and Hydrogen Evolution Reactions. This catalyst features a novel hybrid nanostructure comprising Co-Ni-Mn oxides integrated onto nitrogen- and cobalt-co-doped reduced graphene oxide (N,Co-rGO). The synthesis involved the improved Hummers’ method for graphene oxide preparation, followed by nitrogen and cobalt doping via calcination, and deposition of Co-Ni-Mn oxides through a solvothermal process. Physicochemical and electrochemical characterizations confirmed the successful formation of a mesoporous structure and efficient synergy between the metal oxides and graphene substrate. The NiCoMn@N,Co-rGO composite exhibits superior catalytic efficiency in facilitating the Oxygen Evolution Reaction in alkaline media, achieving a potential of 1.58 V at 10 mA/cm² (overpotential: 0.27 V), compared to 1.62 V (overpotential: 0.50 V) for NiCoMn oxide. For the Hydrogen Evolution Reaction, it achieves a potential of -0.50 V at -10 mA/cm² (overpotential: 0.49 V), similar to NiCoMn oxide. The improved efficiency is ascribed to the synergistic effects of nitrogen and cobalt doping in the reduced graphene oxide framework, improving conductivity, active site accessibility, and structural stability. These findings establish NiCoMn@N,Co-rGO as a more efficient electrocatalyst for OER.https://www.abechem.com/article_719416_0a0fd7f94c4f2bb4a7bb32764cb14671.pdf