Mustafa Uçan

Synthesis and Characterization of New Schiff Bases and Their Cobalt(II), Nickel(II), Copper(II), Zinc(II), Cadmium(II) and Mercury(II) Complexes

Nickel(II), copper(II), cobalt(II), zinc(II), cadmium(II) and mercury(II) complexes chelates containing the Schiff base ligands methyliminoisonitroso‐2‐ acetylnaphthalene (HL1) and benzyliminoisonitroso‐2‐acetylnaphthalene (HL2) have been prepared. The results suggest that the Schiff bases function as bidentate ligands and indicate a mononuclear structure for the Cu(II) complexes with square‐planar geometry. The Ni(II), Zn(II), Hg(II) and Cd(II) complexes are of tetrahedral geometry and the Co(II) complexes with octahedral geometry with water molecules at the axial positions. These compounds have been characterized by elemental analyses, magnetic susceptibility, mass, IR, UV, 1H and 13C NMR spectroscopy.

Comparison of Column Solid-Phase Extraction Procedures for Spectrophotometric Determination of E129 (Allura Red) in Foodstuff, Pharmaceutical, and Energy Drink Samples.

Two novel spectrophotometric determination procedures based on retention of Allura Red onto Amberlite XAD-1180 and XAD-16 resins for its preconcentration, purification, and separation were developed. Analytical parameters of the methods including pH, eluent type, sample volume, and sample and eluent flow rates, were investigated and optimized. Interference effects of some cations, anions, and widely used food dyes were also investigated. Detection limits of the two methods were found to be 1.2 and 1.5 μg/L for XAD-1180 and XAD-16 columns, respectively, under optimum conditions. Linear calibration curve ranges of the methods were 0.4-8.0 and 0.5-6.0 μg/mL of Allura Red for XAD-1180 and XAD-16 resins, respectively. Preconcentration factors were found as 80 for both the XAD-1180 and XAD-16 columns using maximum sample volume and minimum eluent volume. RSDs of the methods were below 6% throughout all experiments. All absorbance measurements were performed at 506 nm. Validations of the methods were performed comparatively with determination of the Allura Red contents of some foodstuff, pharmaceutical, and energy drink samples. Allura Red concentrations in investigated solid and liquid samples ranged from 298 to 501 μg/g and 53.8 to 508 μg/mL, respectively. Satisfactory results were obtained from the real samples analysis. Allura Red contents of samples were determined to be highly similar using the two extraction methods. Comparisons of the methods were performed by analysis of Allura Red contents of the real samples. In addition to analytical parameters, adsorption isotherm studies were performed for the two kinds of Amberlite resins. It was observed that developed methods fit the linear form of the Freundlich adsorption isotherm model. All of the experimental results suggested that the developed SPE procedures are suitable for separation, preconcentration, and determination of Allura Red in solid and liquid matrixes.

SIMULTANEOUS PRECONCENTRATION AND DETERMINATION OF Cu2+, Ni2+ AND Cd2+ BY MICELLE MEDIATED EXTRACTION IN FOOD AND WATER SAMPLES

An effective extraction procedure based on the complexation of Cu 2+ , Cd 2+ , and Ni 2+ with dithizone and extraction of these complexes by Tergitol NP-7 surfactant was developed. Micelle mediated extraction parameters such as pH, ligand and surfactant concentration, incubation time and temperature were investigated and optimized. Effects of external and internal interfering ions, linear dynamic range, detection and quantitation limits were examined and determined under optimal conditions. Detection limits were found as 0.5, 1.8 and 2.0 mg L -1 for Cu 2+ , Ni 2+ and Cd 2+ , respectively. Linear dynamic range values were between 0.125-2, 0.125-2.5 and 0.05-1.4 μg mL -1 for Cu 2+ , Ni 2+ and Cd 2+ ions, respectively. Applicability, accuracy and precision of the method were checked with standard reference materials and real sample analyses by analyte addition technique. Finally, optimized method was applied to determine Cu 2+ , Ni 2+ and Cd 2+ contents of standard reference materials, mushrooms and water samples. Quantitative and accurate results were obtained from the analysis of standard reference materials and real samples.