Salih Yildiz

Ion exchange equilibria of heavy metals in aqueous solution on new chelating resins of sporopollenin

Studies have been conducted on the sorption of several heavy metal ions Cu(II), Ni(II), Zn(II), Cd(II) and Al(III) from aqueous solutions on the new chelating exchangers of sporopollenin (Lycopodium clavatum) as a function of pH at several temperatures between 20 and 50°C. The novel metal-ligand exchange resins possessing oxime and carboxylic acid side arm functionality were prepared through the reaction of diaminosporopollenin with dichloroantiglyoxime and bromoacetic acid. The sorption of all metals increased considerably in the range of pH 6–10 and was observed in sequence as: Cu ≥ Ni > Zn > Cd > Al for carboxylated-diaminoethyl-sporopollenin (DAEC) and Ni ≥ Cu > Zn > Cd > Al for bis-diaminoethyl-glyoxime-sporopollenin (bDAEG). The level of pH of the aqueous medium had a large influence on the sorption capacity, and the uptake of metals, except Al(III), was found to be 90% or more. The metal-form resins afforded complete recovery of the sorbed species by acid stripping. Both resins also showed high stability towards concentrated acids and bases and retained their high capacity for heavy metals.

Ligand-Exchange Chromatography of Some Amino Acids on Co(II)-Loaded CMDAE-Sporopollenin Resin

Abstract Sporopollenin obtained from Lycopodium clavatum has been modified as an ligand-exchange material. In this study, the possibility of using sporopollenin as a ligand exchanger in the chromatographic separation of amino acids is examined. Since sporopollenin has important advantages (it is stable to chemicals and has a constant mesh size), it can be used as a column packing material. By first treating sporopollenin with 1,2-diaminoethane and then with bromoacetic acid, carboxylated diaminoethylsporopollenin (CMDAE-sporopollenin) was obtained. This new resin was loaded with Co(II) transition element and used as a ligand-exchange material in the separation of amino acids. Using the ligand-exchange technique on Co(II)-loaded carboxylated diaminoethylsporopollenin is a suitable chromatographic method for the separation of most common amino acids.

Sorption of Heavy Metal Ions on New Metal-Ligand Complexes Chemically Derived from Lycopodium clavatum

Sorption of heavy metal ions from aqueous solution has been investigated as a function of pH using a novel exchanger system whereby Lycopodium clavatum is functionalized with carboxylate and glyoxime metal-ligand complexes. The new ligand exchangers were prepared using a reaction of diaminosporopollenin with various metal-ligand complexes of glyoxime and monocarboxylic acid. The sorptive behavior of these metal-ligand exchangers and the possibilities to remove and to recover selectively heavy metal cations using these systems are discussed on the basis of their chemical natures and their complexing properties.

Amperometric biosensors based on deposition of gold and platinum nanoparticles on polyvinylferrocene modified electrode for xanthine detection.

In this study, new xanthine biosensors, XO/Au/PVF/Pt and XO/Pt/PVF/Pt, based on electroless deposition of gold(Au) and platinum(Pt) nanoparticles on polyvinylferrocene(PVF) coated Pt electrode for detection of xanthine were presented. The amperometric responses of the enzyme electrodes were measured at the constant potential, which was due to the electrooxidation of enzymatically produced H(2)O(2). Compared with XO/PVF/Pt electrode, XO/Au/PVF/Pt and XO/Pt/PVF/Pt exhibited excellent electrocatalytic activity towards the oxidation of the analyte. Effect of Au and Pt nanoparticles was investigated by monitoring the response currents at the different deposition times and the different concentrations of KAuCl(4) and PtBr(2). Under the optimal conditions, the calibration curves of XO/Au/PVF/Pt and XO/Pt/PVF/Pt were obtained over the range of 2.5 × 10(-3) to 0.56 mM and 2.0 × 10(-3) to 0.66 mM, respectively. The detection limits were 7.5 × 10(-4)mM for XO/Au/PVF/Pt and 6.0 × 10(-4)mM for XO/Pt/PVF/Pt. The effects of interferents, the operational and the storage stabilities of the biosensors and the applicabilities of the proposed biosensors to the drug samples analysis were also evaluated.

Modified Sporopollenin as a Novel Anion, Cation and Ligand Exchange Medium

Abstract Ion-exchange and ligand-exchange chromatography with the modified sporopollenin is a useful technique for the rapid separation of nucleosides, nucleotides, amino acids, amines and transition elements. The sporopollenin has been modified for use as anion-, cation- and ligand-exchanger; diaminosporopollenin being the anion-exchanger form, sulphonated sporopollenin the cation-exchanger form and carboxylated sporopollenin the ligand exchanger form. Sporopollenin was aminated by the treatment with 1, 2 diaminothane for separation of nucleotides by anion-exchange; treatment with chlorosulphonic acid gave sulphonated sporopollenin for separation of amino acids by cation-exchange and treatment with brornoacetic acid gave carboxylated diaminosporopollenin for separation of nucleotides, nucleosides, amines and transition elements.

Sorption of Aromatic Amines on a New Ligand Exchanger of Sporopollenin-Bound Co2+ Ion

Abstract The mechanism of ligand-exchange sorption of aromatic amines such as p-chloroaniline, p-toluidine, and p-nitroaniline as ligands on a Co2+-loaded ligand exchanger has been studied. The observed rate seems to be related to the rate of ligand sorption with the mobile phase and pH in the aqueous phase. The saturation capacity and binding constant of ligand sorption on the resin increase with increasing basicity of amines. The rate of attainment of equilibrium sorption of aromatic amines is seen to be nearly similar. Coupled with the fact that different concentrations of solution were employed, these results may be interpreted as indicating that particle diffusion is the rate-controlling step. On the contrary, film diffusion was not rate-controlling step in the ligand sorption process under the conditions employed. It is shown that the kinetic parameters measured in single component experiments provide good prediction behavior. The pH dependencies and sorption isotherms of aromatic amines on the resi...

Ligand-Exchange Chromatography of Aromatic Amines on Resin-Bound Cobalt Ion

Abstract The use of cobalt metal for the selective separation of aromatic amines is completed with a chemically bonded diamine and glyoxime functional groups onto Lycopodium clavatum. Oximes and amines are excellent complexing agents for transition metal ions. Cobalt(II) metal ions can easily be immobilized on bis-diami-noethyl-glyoximated sporopollenin (bDAEG-sporopollenin). The ligand-exchange behavior of modified Lycopodium clavatum with respect to aromatic amines was, investigated. This will permit the evaluation of bDAEG-sporopollenin ligand exchangers for their utilization as sorbents in the recovery, pollution control, and elimination of amines from wastewater.

COLUMN CHROMATOGRAPHY AND KINETICS OF NUCLEOSIDES AND NUCLEIC ACID BASES ON IMMOBILIZED NICKEL- AND COBALT-CDAE-SPOROPOLLENIN

ABSTRACT Sporopollenin, a natural polymer, has been modified for application as a ligand-exchange material. The ligand-exchange Chromatography with the functionalized Lycopodium clavatum is a useful method for the rapid separation of nucleosides and nucleic acid bases. The synthesis of tris(carboxymethyl) ethylene diamine Lycopodium clavatum has been described. The resin contained functional diaminoethane and carboxyl groups. Nickel(II) and cobalt(II) metal ions can easily be immobilized on this carboxylated-diamino-ethyl (CDAE)-sporopollenin. Physico-chemical and chelating properties of Lycopodium clavatum have been studied extensively. Ligand-exchange chromatography of CDAE-sporopollenin has also been compared to the conventional synthetic chelex-100 resin. The kinetics of cytidine in CDAE-sporopollenin resin has been investigated. The rate measurements have been made by a potentiometric technique. The relative rates at which nucleosides bind to the resin are determined by the actual chemical-exchange r...

Ligand-Exchange Chromatography of Nucleosides, Nucleic Acid Bases and Amines of Copper(II) Glyoximated-Lycopodium Clavatum with Refractive Index Detection

Abstract Ligand-exchange separation of nucleosides, nucleic acid bases and amines has been studied by using a new exchanger obtained by functionalyzing Lycopodium Clavatum with glyoxime. This study shows that 1igand-exchange chromatography with glyoximated-lycopodium clavatum can provide new opportunities for the rapid separation of ligands.

Hypoxanthine Biosensor Based on Immobilization of Xanthine Oxidase on Modified Pt Electrode and Its Application for Fish Meat

In this study, hypoxanthine biosensor based on immobilization of xanthine oxidase on polyvinylferrocenium perchlorate matrix coated Pt electrode for detection of hypoxanthine was presented. The steady-state background current of the biosensor was measured at+0.5V, which was due to the electrooxidation of enzymatically produced H2O2. The biosensor exhibited a linear range from 2.15 × 10−3mM to 1.03mM (r = 0.9963) with a detection limit of 6.5 × 10−4mM (S/N = 3) for the detection of hypoxanthine. The storage stability of the biosensor, the effect of interference by uric acid, and the applicability to fish sample of the biosensor analysis were also evaluated.