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TIRIS, GİZEM

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GİZEM

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TIRIS

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Now showing 1 - 8 of 8
  • Publication
    Determination of active ingredients in antihypertensive drugs using a novel green HPLC method approach
    (2022-09-01T00:00:00Z) TIRIS, GİZEM; Mehmandoust, Amirhossein; Karimi, Fatemeh; ERK, NEVİN; TIRIS, GİZEM
    © 2022 Elsevier LtdA novel, sensitive, fast, and pratic RP-HPLC methods were presented for the quantitative amounts of Telmisartan (TEL) and Olmesartan (OLM) in the presence of Amlodipin (AML) in a binary mixture of pharmaceutical preparation. Waters Spherisorb ODS-2 C18 column was used for separation. These methods were valid over linearity ranges of 2.5–30 μμg/mlL, 2–85 μμg/mlL, and 2–35 μμg/mlL for OLM, TEL, and AML, respectively. The mobile phase system consisted of acetonitrile:methanol: phosphate buffer at pH 3.0 (65:5:30 v/v/v), and the flow rate was 1,5 mlL/min for OLM and AML. The mobile system-s other mixture (TEL and AML) was acetonitrile:methanol: phosphate buffer at pH 2.5 (65:5:30 v/v/v), and the flow rate was 1,5 mlL/min. These procedures were successfully applied to bulk, laboratory synthetic mixture, and medicinal dosage forms to use active ingredients quantitatively. The studied methods were validated according to ICH guidelines. In the developed HPLC method, the limit of detection values was found to be 0.020 μμg/mlL for TEL, 0.025 μμg/mlL for OML, and 0.070 μμg/mlL for AML. The correlation coefficients for the HPLC method were found to be 0.9938 for TEL, 0.9996 for OML, and 0.9982 for AML. The calibration range is between 2.5 and -30, 5–35, and 2–85 μμg/mlL for OLM, AML, and TEL, respectively. The proposed HPLC method is a convenient, effective, sensitive, green, and time-saving method for the rapid determination of TEL and OLM in the presence of AML.
  • Publication
    A novel stability-indicating method for determination of a new antidepressant effect of vortioxetine in a pharmaceutical formulation by using RP-HPLC
    (2020-12-01T00:00:00Z) TIRIS, GİZEM; Alver, Cansu; ERK, NEVİN; TIRIS, GİZEM
    Background: A novel rapid, accurate, and stability-indicating reversed-phase high performance liquid chromatographic (RP-HPLC) and first derivative spectrophotometric determination were explained for the assay of vortioxetine (VRT) in bulk and pharmaceutical formulations. For RP-HPLC method, optimal separation and determination of VRT were achieved with a Waters Symmetry C-18, (100 x 4.6 mm, 3.5 mu m) analytical column using a mobile phase consisting of methanol:0.05 M potassium dihydrogen phosphate (pH:3.0 +/- 0.05) (30:70, v/v) in isocratic mode with flow rate of 1.3 mL min(-1). Injection volume was 20 mu L. The maximum absorption wavelength of VRT is 225.0 nm; hence, 225.0 nm was studied as the detection wavelength and column at 50 degrees C temperature. The caffeine was used as the internal standard (IS). On the other hand, the first derivative spectrophotometric method for the analysis of vortioxetine was performed by measuring the amplitude at 251.7 and 272.6 nm.
  • Publication
    A sensitive voltammetric sensor for specific recognition of vitamin C in human plasma based on MAPbl(3) perovskite nanorods
    (2022-01-01T00:00:00Z) TIRIS, GİZEM; Khoshnavaz, Yasamin; Oven, Elif Naz; Mehmandoust, Mohammad; ERK, NEVİN; TIRIS, GİZEM
    A novel and sensitive electrode was suggested for the rapid determination of ascorbic acid (AA) using a glassy carbon electrode (GCE) modified with synthesized MAPbl(3) and L-cys (L-cys/MAPbl(3)/GCE). Determination of ascorbic acid as an important component of the human diet due to help in decreasing blood pressure and improving endothelial function is crucial. The synthesized MAPbl(3) was characterized by different methods, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The fabricated electrode exhibited superior electrical conductivity and fast electron transfer kinetics. The results illustrated that the developed electrode had an outstanding electrocatalytic activity towards the oxidation of AA in 0.1 M Britton-Robinson buffer(B-R) as a supporting electrolyte. The modified electrode demonstrated a linear range in differential pulse voltammetry of 0.02-11.4 mu M with a low detection limit of 8.0 nM for ascorbic acid. It can be stated that the proposed sensor can be successfully applied to the determination of ascorbic acid in human plasma samples.
  • Publication

    A reusable and sensitive electrochemical sensor for determination of idarubicin in environmental and biological samples based on NiFe2O4 nanospheres anchored N-doped graphene quantum dots composite; an electrochemical and molecular docking investigation

    (2022-09-01T00:00:00Z) Mehmandoust, Mohammad; Pourhakkak, Pouran; TIRIS, GİZEM; Karimi-Maleh, Hassan; ERK, NEVİN; TIRIS, GİZEM
    An ultrasensitive and selective voltammetric sensor with ultra-trace level detection limit is introduced for idarubicin (IDA) determination in real samples. The as-synthesized nanocomposite was characterized by several techniques, including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Raman spectroscopy, Energy-dispersive X-ray spectroscopy (EDX), and Field emission scanning electron microscopy (FESEM). The electrocatalytic performance of the developed electrode was observed by cyclic voltammetry (CV), differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), and chronoamperometry. The limit of detection (LOD) of the developed sensor for idarubicin is 1.0 nM, and the response is found to be in the dynamic concentration range of 0.01-1.9 mu mol/L in a Britton-Robinson buffer (B-R, pH = 6.0). Moreover, the fabricated electrode illustrated high selectivity with good repeatability and reproducibility for diagnosing idarubicin as an anthracycline antileukemic drug. Furthermore, to evaluate the validity of the recommended method, three real samples, including human plasma, urine, and water samples, were analyzed with satisfactory recovery and compared with high-performance liquid chromatography (HPLC). The minor groove-binding mode of interaction was also supported by docking simulation studies, emphasizing that IDA can bind to ds-DNA preferably and confirmed experimental results. The reduced assay time and the possibility of measuring a single sample with another anticancer drug without any interference are significant advantages compared to the HPLC. The developed and validated sensor could be a valuable point-of-care diagnostic tool for IDA quantification in patients.
  • Publication
    The power of High Impact Amplitude Manipulation (HIAM) technique for extracting the basic spectra of two Fixed-dose combinations (FDC) -Spectrophotometric purity analysis via spectral contrast angle
    (2022-05-15T00:00:00Z) Saleh, Sarah S.; Lotfy, Hayam M.; TIRIS, GİZEM; ERK, NEVİN; El-Naem, Omnia A.; TIRIS, GİZEM
    © 2022 Elsevier B.V.HIAM technique allows the extraction of the original constant signal of each single component out of interference signals of a mixture and further transformed into basic spectrum (D0). It includes the methods: ratio subtraction coupled with unified constant subtraction (RS-UCS), constant center (CC) and constant extraction (CE). The technique was introduced for the analysis of two pharmaceutical formulations used to treat cardiovascular diseases. The formulations are binary combinations of Amlodipine (AML) with either Atorvastatin (ATR) or Candesartan (CND) which shows interefernce absorbance signals. The technique was valid over the linearity range of (5.0–35.0 µg/ml) for AML, ATR and CND with recovery percentage 100.40 ± 1.88, 100.00 ± 0.86 and 99.83 ± 1.07, respectively. The extracted signals were tested for its purity by spectral contrast angle (cos θ) to illustrate the efficency of the HIAM technique where cos θ values ranges from (0.9902 to 0.9986). The presented technique was fully validated regarding ICH guidelines and were statistically compared using one-way ANOVA at 95% confidence.