Browsing by Author "Talay Pinar, Pinar"

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Electroanalytical Determination of Salbutamol in Pharmaceutical Formulations Using Cathodically Pretreated Boron-Doped Diamond Electrode
(Marmara Univ, 2018) Talay Pinar, Pinar; Ali, Hoshyar Saadi; Abdullah, Abdullah Abdulwahed; Yardim, Yavuz; Senturk, Zuhre
This paper examined for the first time the possibilities of the usage of the cathodically pretreated borondoped diamond (CPT-BDD) electrode for the redox behavior of salbutamol (SAL) using cyclic and adsorptive stripping voltammetry. The cyclic voltammograms showed an irreversible and adsorption-controlled oxidation peak at about +1.0 V in the Britton-Robinson (BR) buffer (pH 9.0) solution. Under the optimized experimental condition, using square-wave adsorptive stripping mode, the compound yielded a well-defined voltammetric response in BR buffer, pH 9.0 at +0.95 V (vs. Ag/AgCl) (after 30 s accumulation at an open circuit condition). A linear calibration graph was obtained in the concentration range of 4.15 to 83 mu g mL(-1) (1.73x10(-5) -3.47x10(-4) M). A detection limit of 1.21 mu g mL(-1) (5.06x10(-6) M) was observed. The suggested method was also applied to the determination of SAL in the drug formulations.
Electrochemical Behavior of the Antineoplastic Agent Etoposide at a Graphene-Based Modified Electrode: Its Square-Wave Adsorptive Stripping Voltammetric Determination in the Pharmaceutical Formulations
(Editura Acad Romane, 2018) Talay Pinar, Pinar; Saka, Cafer; Yardim, Yavuz
An electrochemical sensor based on the graphene (GR) was prepared, and used for the determination of etoposide (ETO). The electrochemical behaviors of this compound on GR modified glassy carbon electrode (GR/GCE) were investigated by cyclic voltammetry and square-wave adsorptive stripping voltammetry (SWAdSV). Using SWAdSV, a linear calibration curve was obtained for ETO determination in 0.1 M Britton-Robinson (BR, pH 4.0) buffer solution at +0.56 V (vs. Ag/AgCl) (after 30 s accumulation at 0.1 V). A linear relationship was found between peak currents and the concentration of ETO within 0.025 to 0.5 mu g mL(-1), with a detection limit of 0.0023 mu g mL(-1). The developed method was successfully applied to the determination of ETO in the pharmaceutical formulations with good recoveries.
Electrochemical Behaviour of Ofloxacin in Pharmaceutical and Biological Samples Using a Boron-Doped Diamond Electrode in Using Anionic Surfactant
(Gazi Univ, 2018) Talay Pinar, Pinar
This paper examined use of a boron doped diamond electrode (BDDE) for the electroanalysis of ofloxacin (one of the fluoroquinolone compounds) by cyclic voltammetry (CV) and square wave voltammetry (SWV) in the presence of anionic surfactant (sodium dodecyl sulfate, SDS). The current signal due to the oxidation process was a function of the amount of ofloxacin, pH of the medium, effect of SDS and scan rate. Cyclic voltammetric studies indicated an irreversible behaviour of ofloxacin in phosphate buffer solution at pH 2.0 with well-defined oxidation peak at + 1.24 V (absence SDS) and + 1.21 V (presence of SDS) vs. Ag/AgCl, respectively. With optimized experimental parameters, the current response of ofloxacin was proportionally linear in the concentration range from 1.0x10(-7) to 3.5x10(-6) M. A detection limit of 1.76x10(-8) M was observed anodically electrochemical surface pretreatments. The practical applicability of the developed method was demonstrated on the determination of ofloxacin in human urine and pharmaceutical samples. In this way, BDD electrode may represent an efficient alternative to widely used modified electrodes in the determination of fluoroquinolone compounds.
First Electrochemical Investigation of New Generation Antineoplastic Agent Ceritinib at a Boron-Doped Diamond Electrode Based on the Pre-Enrichment Effect of Anionic Surfactant
(Springer, 2023) Talay Pinar, Pinar; Uzun, Gokhan; Senturk, Zuhre
In the present study, the first electrochemical investigation of ceritinib, which is a small-molecule tyrosine kinase inhibitor used as a new generation targeted anticancer drug, was described. For this purpose, a commercially available boron-doped diamond electrode pretreated cathodically was used. Using cyclic voltammetry, ceritinib presented two pairs of oxidation/reduction peaks in aqueous solution. The electrode process is controlled by a mixed diffusion and adsorption mechanism. The effects of pH and nature of the supporting electrolyte in the absence and the presence of anionic surfactant, sodium dodecylsulfate (SDS), pre-concentration variables and other instrumental parameters were demonstrated on the current response of ceritinib. It was observed that the addition of 8 x 10(-4) mol L-1 SDS to the ceritinib solution prepared in 0.1 mol L-1 HNO3 improved the sensitivity of the stripping voltammetric measurements. By applying square-wave adsorptive stripping voltammetry (after 30 s pre-concentration at open-circuit condition), the calibration curves were linear for both oxidation peaks, Ia (at similar to + 0.99 V) and IIa (at similar to + 1.20 V) in the concentration range from 0.075 to 2.0 mu g mL(-1) (1.34 x 10(-7)-3.58 x 10(-6) mol L-1), with detection limits of 0.014 mu g mL(-1) (2.50 x 10(-8) mol L-1) for Ia, and 0.011 mu g mL(-1) (1.97 x 10(-8) mol L-1) for IIa. The applicability of the developed methodology using the electrochemical signal IIa was verified by analysis of commercial capsule formulations and model human urine samples.