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Öğe New voltammetric strategy for determination and electrochemical behaviors of metformin by pencil graphite electrode(ICNTC, 2020) Altunkaynak, Yalçın; Yavuz, Ömer; Levent, AbdulkadirMetformin(MET), an oral antidiabetic drug commonly used in the treatment of diabetes, is a drug that increases insulin sensitivity in the biguanide group [1]. MET shows its pharmacological effect by lowering the glucose level in the blood. In the literature research, there are studies using electrochemical techniques for the analysis of MET in biological fluid and drug forms[1-6]. In this study, the electrochemical properties of MET, one of the drugs used in the treatment of diabetes, were performed using a pencil graphite electrode in NaOH (0.1 M) solution. This compound was recorded with an irreversible and diffusion controlled adsorption oxidation peak at approximately +1.28 V by cyclic voltammetry. With square wave stripping voltammetry, it was observed that the peak current signals of MET in the concentration range of 2.76-24.8 µM in 0.1M NaOH solution increased linearly. At a concentration of 2.76 µM (n = 9), the limit of detection and relative standard deviation were calculated as 9.03 nM (1.495 ngmL-1 ) and 3.25 %, respectively. This method has been successfully applied for MET analysis in pharmaceutical preparations and urine samples without any separation.Öğe Application of bismuth film electrode in determination of Loratadine by cathodic stripping voltammetry in the presence of cationic surfactant(ICNTC, 2020) Önal, Günay; Altunkaynak, Yalçın; Levent, AbdulkadirLoratadine, histamine - H1 antihistamine receptors it is being used for many years in the treatment of an allergic condition illustrating the effects on[1]. When the literature is reviewed, there are limited number of studies on Loratadine based on electrochemistry [2-5]. Stripping voltammetry is a very sensitive and selective method for determining drugs and organic / inorganic substances in biological fluids. The electrochemical behavior of Loratadine with BiFE in different supporting electrolyte and pH values, and its performance characteristics in electroanalytical determinations were investigated by cyclic voltammetry and linear sweep cathodic stripping voltammetry (LS-CSV) methods. LS-CSV measurements on the BiFE surface of 6.5x10-4 M Loratadine in 0.04 M BR buffer (pH 7.0) and 4 mM cationic surfactant (CTAB) were taken between 0.0 V and -2.0 V. Loratadine gave a voltammetric response about at -1.486 V. The limit of detection was found LOD = 1.2x10-7 M* at the BIFE surface at liner concentration range [1.305x10-6 M – 14.3x10-6 M, r = 0,998* (n = 11)]. This voltammetric method, developed under optimum conditions, has been successfully applied to pharmaceutical formulations of Loratadin as fast, easy to apply, sensitive and environmentally friendly.Öğe Electrochemical oxidation of vildagliptin on pencil graphite electrode: Extremely sensitive determination in drugs and human urine with square wave voltammetry(ICNTC, 2020) Altunkaynak, Yalçın; Yavuz, Ömer; Levent, AbdulkadirVildagliptin (VLDG), one of the antidiabetic agents, is a dipeptidyl peptidase 4 inhibitor. It is a drug developed for oral administration[1]. In the literature, there is only one study in which electrochemical methods were used for the analysis of Vildagliptin in biological fluid and drug forms[2]. In this study, the electrochemical properties of VLDG, which is one of the drugs used as an antidiabetic agent, were determined by using pencil graphite electrode in phosphate buffer solution (PBS/pH 9.0). The irreversible and diffusion controlled adsorption oxidation peak was measured by cyclic voltammetry at approximately +1.13 V for this compound. Using square wave stripping voltammetry, the current showed a linear correlation in PBS buffer at pH 9.0, with a concentration range of 2.94 to 49.98 µM. At a concentration of 2.94 µM (n=9), the limit of detection of 8.20 nM (2.48 ng mL-1 ) and a relative standard deviation of 2.95 % were calculated. This method was successfully applied for VLDG analysis without any separation in pharmaceutical preparations and urine samples
