Person:
TIRIS, GİZEM

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GİZEM
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TIRIS
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Now showing 1 - 6 of 6
  • PublicationMetadata only
    Fabric phase sorptive extraction combined with high performance liquid chromatography for the determination of favipiravir in human plasma and breast milk
    (2023-01-01) TIRIS G.; Gazioglu I.; Furton K. G.; Kabir A.; Locatelli M.; TIRIS, GİZEM; GAZİOĞLU, IŞIL
    A fast procedure obtained by the combination of fabric phase extraction (FPSE) with high performance liquid chromatography (HPLC) has been developed and validated for the quantification of favipiravir (FVP) in human plasma and breast milk. A sol-gel polycaprolactone-block-polydimethylsiloxane-block-polycaprolactone (sol-gel PCAP-PDMS-PCAP) coated on 100% cellose cotton fabric was selected as the most efficient membrane for FPSE in human plasma and breast milk samples. HPLC-UV analysis were performed using a RP C18 column under isocratic conditions. Under these optimezed settings, the overall chromatographic analysis time was limited to only 5 min without encountering any observable matrix interferences. Following the method validation pro-cedure, the herein assay shows a linear calibration curve over the range of 0.2-50 mu g/mL and 0.5-25 mu g/mL for plasma and breast milk, respectively. The method sensitivities in terms of limit of detection (LOD) and limit of quantification (LOQ), validated in both the matrices, have been found to be 0.06 and 0.2 mu g/mL for plasma and 0.15 and 0.5 mu g/mL for milk, respectively. Intraday and interday precision and trueness, accordingly to the International Guidelines, were validated and were below 3.61% for both the matrices. The herein method was further tested on real samples in order to highlight the applicability and the advantage for therapeutic drug monitoring (TDM) applications. To the best of our knowledge, this is the first validated FPSE-HPLC-UV method in human plasma and breast milk for TDM purposes applied on real samples. The validated method provides fast, simple, cost reduced, and sensitive assay for the direct quantification of favipiravir in real biological matrices, also appliyng a well-known rugged and cheap instrument configuration.
  • PublicationMetadata only
    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.
  • PublicationMetadata only
    Low-cost voltammetric sensor based on reduced graphene oxide anchored on platinum nanoparticles for robust determination of Favipiravir in real samples
    (2023-01-01) Bouali W.; ERK N.; Kholafazadehastamal G.; Naser M.; TIRIS G.; TIRIS, GİZEM
    © 2022 Elsevier B.V.This research describes a simple, sensitive, and disposable modified glassy carbon electrode constructed using platinum nanoparticles anchored on reduced graphene oxide nanocomposite as a conductive modifier (Pt@rGO/GCE) to detect an anti-coronavirus drug, Favipiravir (FAV). The as-synthesized nanocomposite was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscopy (AFM). Under optimized conditions, the square wave voltammetry (SWV) method was used to determine trace amounts of FAV in real samples. The proposed electrode demonstrated a wide linear concentration range of 3.16 to 100.0 μM with a low detection limit (LOD) of 2.46 μM. Moreover, the developed electrode showed outstanding selectivity in the presence of several interferences with high repeatability and reproducibility. Finally, the developed electrode was applied to detect FAV in human plasma and pharmaceutical samples.
  • PublicationMetadata only
  • PublicationMetadata only
    Simultaneous analysis of sacubitril and valsartan by novel analytical methods with green approach
    (2024-04-01) TIRIS G.; Ayse Genc A.; ERK N.; TIRIS, GİZEM
    A novel high performance liquid chromatography (HPLC) and spectrophotometric analysis were applied for quantification of active substances of sacubitril (SAC) and valsartan (VAL). HPLC experiments were conducted on the Waters Spherisorb® (3.0 µm 60.0x4.0 mm) column. Preparation of mobile phase A: 200 mL of 0.1 % solution of trifluoroacetic acid in water and 800 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume are mixed. Preparation of mobile phase B: 800 mL of a 0.1 % solution of trifluoroacetic acid in water and 200 mL of 0.1 % solution of trifluoroacetic acid in acetonitrile by volume were mixed. It was given to the system at the ratio of Mobile Phase A: Mobile Phase B (35:65 v:v). The specimen was injected into the column at 15.0 µL. A detection wavelength of 254.0 nm was preferred for the compound and the flow rate was 2.0 mL/min. Analysis was completed in 4.0 min. The column oven temperature was adjusted to 40.0 °C. The methods were evaluated in terms of green chemistry. The methods have been validated according to ICH guidelines. For HPLC method calibration graphs were constructed in the 20.0– 145.0 and 20.0 – 155 µg/mL SAC and VAL respectively with an R2 of 1.000. In recovery experiments, the RSD values were calculated to be 0.08 % and 0.34 % for SAC and VAL, respectively. Additionally, in intraday and interday experiments, percent RSD values were found to be between 0.23 and 0.49. The method developed for the analysis of the active substances has been developed with a short analysis time and is cost effective. SAC and VAL were determined using a novel method for spectrophotometric analysis. The determination was performed simultaneously using the applied method. This method is a constant center method. Calibration graphs were constructed in the 2.0– 20.0 and 2.0 – 25 µg/mL SAC and VAL with an R2 of 0.9998 and 0.9999 respectively. It is a greenness method in terms of the analysis time and solvent used.