Yazar "Solak, Ali Osman" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    Carbonaceous Materials-12: a Novel Highly Sensitive Graphene Oxide-Based Carbon Electrode: Preparation, Characterization, and Heavy Metal Analysis in Food Samples
    (Springer, 2016) Yavuz, Samet; Erkal, Asli; Kariper, Ishak Afsin; Solak, Ali Osman; Jeon, Seungwon; Mulazimoglu, Ibrahim Ender; Ustundag, Zafer
    Graphene oxide (GO) was covalently attached to glassy carbon (GC) electrode (GC-O-GO) for fabricating nanosensors to determine trace Pb2+ and Cd2+ using differential pulse anodic stripping voltammetry (DPASV). Surface characterization of the nanofilm-covered electrode was performed via electrochemical cyclic voltammetry (CV), transmission electron microscopy (TEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) techniques. Surface pKa of the GO covalent attached GC (GC-O-GO) was calculated via CV. Under optimal conditions, a linear response was found for Pb2+ and Cd2+ in the range from 1 x 10(-8) to 1 x 10(-12) M. The limit of detections (LODs) of Pb2+ and Cd2+ were 0.25 pM and 0.28 pM, respectively. The method shows good reproducibility, and stability was successfully applied to measure Pb2+ and Cd2+ levels in rice, soya, milk, and tap water samples, with good agreement with those obtained by the standard inductively coupled plasma optical emission spectrometry (ICP-OES) method. The method was evaluated by application with the simultaneous determination of the ions in food samples (n = 6) using the standard addition method. The recoveries of the Pb2+ and Cd2+ were up to 98 %.
  • Küçük Resim Yok
    Öğe
    A novel highly sensitive carbon-based HMPD/GC sensor electrode: copper ions analysis in flour and water samples
    (Desalination Publ, 2018) Durmus, Nagihan; Yilmaz, Ecir; Mulazimoglu, Aysen Demir; Mercimek, Bedrettin; Cukurovali, Alaaddin; Yilmaz, Ibrahim; Solak, Ali Osman
    In this research, (Z)-2-(2-(hydroxyimino)-2-(3-methyl-3-phenylcyclobutyl) ethyl)-3a,7a-dihy-dro-1H-isoindole-1,3(2H)-dione, HMPD molecule has been grafted to the glassy carbon (GC) electrode surface. The HMPD-modified GC electrode has been originally developed and it used for the quantitative determination of Cu(II) in flour and water samples. The modification steps have been performed using cyclic voltammetry (CV). CV, electrochemical impedance spectroscopy and scanning electron microscopy have been employed for the characterization processes. Cu(II) standard solutions changing from 1.0 x 10(-9) to 1.0 x 10(-3) M have been prepared and the corresponding peak currents have been measured. From the obtained data calibration equation has been calculated I-p = -1.555C(cu) + 15.86 which is having a 0.9974 correlation coefficient. 10.0 mL of flour and water samples have been mixed with 10.0 mL Britton-Robinson (BR) buffer solution (pH = 5.00) and HMPD/GC sensor electrode has been kept in these mixed solutions for 90 min. Differential pulse voltammetric (DPV) technique has been applied for the measurement of the peak currents. After the application of the developed sensor electrode for Cu(II) detection in flour and water samples, Cu(II) ion concentrations have been calculated from the obtained peak current values, 1.97 and 2.46 mu A. The Cu(II) ion concentrations have been calculated as 1.17 x 10(-9) and 2.41 x 10(-9) M, respectively.