Cengiz Soykan

Indirect speciation of Cr(III) and Cr(VI) in water samples by selective separation and preconcentration on a newly synthesized chelating resin.

A new solid phase extraction method for the speciation, separation and preconcentration of Cr(III) and Cr(VI) was developed. As solid phase material, a new chelating resin, poly N-(4-bromophenyl)-2-methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene was synthesized. Cr(III) was separated from Cr(VI) and preconcentrated by using a column containing chelating resin. Total chromium was determined after the reduction of Cr(VI) to Cr(III) by hydroxylamine hydrochloride as a reducing agent. Then Cr(VI) was calculated by substracting Cr(III) concentration from the total chromium concentration. The parameters such as the effect of pH, eluent type, volume and concentration, flow rate of sample solution, sample volume and effect of interfering ions for the preconcentration of Cr(III) were investigated. The optimum pH was found to be 2. Eluent for quantitative elution was 10 mL of 1 mol L(-1) HCl. The preconcentration factor of the method was 100. At the optimum conditions determined experimentally, the recovery for Cr(III) was found to be 95 +/- 3%. The limit of detection (3s/b) of the method was 1.58 microg L(-1). In order to determine the adsorption behaviour of chelating resin, the adsorption isotherm of Cr(III) was studied. Adsorption capacity and binding equilibrium constant were calculated to be 21.8 mg g(-1) and 1.32 x 10(-2) L mg(-1), respectively. The method was validated by analysing certified reference material (TMDA-54.4 a trace element fortified calibration standard). The proposed method was applied to the determination and speciation of chromium in tap water, lake water, spring water and wastewater samples with satisfactory results.

Synthesis of a novel chelating resin and its use for selective separation and preconcentration of some trace metals in water samples

A new chelating resin, poly[N-(4-bromophenyl)-2-methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene], was synthesized and characterized. The resin was used for selective separation, preconcentration and determination of Cu(II), Ni(II), Co(II), Cd(II), Pb(II), Mn(II) and Fe(III) ions in water samples by flame atomic absorption spectrometry. Effects of pH, concentration and volume of elution solution, sample flow rate, sample volume and interfering ions (Na(+), K(+), Ca(2+), Mg(2+), Fe(3+), Mn(2+), Al(3+), Zn(2+), Pb(2+), Cu(2+), Ni(2+), Cd(2+), Cl(-) and SO(4)(2-)) on the recovery of the analytes were investigated. The sorption capacity of the resin was 25.6, 19.8, 32.1, 41.3, 38.9, 13.9 and 18.3 mg g(-1) for Cu(II), Ni(II), Co(II), Cd(II), Pb(II), Mn(II) and Fe(III), respectively. A high preconcentration factor, 100, and low relative standard deviation, <or=2.5% (n=7) values were obtained. The detection limits (microg L(-1)) were 0.57 for Cu(II), 0.37 for Ni(II), 0.24 for Co(II), 0.09 for Cd(II), 1.6 for Pb(II), 0.19 for Mn(II) and 0.72 for Fe(III). The method was validated by analysing fortified lake water (TMDA-54.4, a trace element fortified calibration standard) and spiked water samples. The method was applied to the determination of the analytes in tap and lake water samples.

Copolymers of phenacyl methacrylate with glycidyl methacrylate: synthesis, characterization and monomer reactivity ratios

Abstract Copolymers with various proportions of phenacyl methacrylate (PAMA) and glycidyl methacrylate (GMA) were prepared by free radical-polymerization in solution in 1,4-dioxane using 2,2′-azobisisobutyronitrile as initiator at 70°C. The polymers were characterized by infrared and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. The copolymer compositions were determined by 1H-NMR spectra. The reactivity ratios were calculated by both Fineman–Ross and Kelen–Tudos methods. Glass transition and decomposition temperatures of copolymers were determined.

Synthesis and characterization of phenacyl methacrylate – acrylonitrile copolymers and determination of monomer reactivity ratios

Copolymers of phenacyl methacrylate (PAMA) with acrylonitrile (AN) were prepared in 1,4-dioxane solution at 70 °C using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The polymers were characterized by 1H and 13C NMR spectroscopic techniques. Also, solubility parameters, inherent viscosities, average molecular weight and densities of polymers were determined. The copolymer compositions were determined by elemental analysis. The monomer reactivity ratios were calculated by application of conventional linearization methods due to Fineman–Ross and Kelen–Tudős. Thermal properties of the polymers were also studied by thermogravimetric analysis and differential scanning calorimetry. © 2000 Society of Chemical Industry

Preparation and thermal degradation of poly(p-substituted phenacyl methacrylates)

Abstract The preparation and thermal degradation of two poly(p-substituted phenacyl methacrylates), poly(p-bromophenacyl methacrylate) [poly(BPMA)] and poly(p-methoxyphenacyl methacrylate [poly(MPMA)], are described. The monomers produced from the reaction of corresponding phenacylchlorides with sodium methacrylate, were polymerized with AIBN as initiator. The monomers and their polymers were characterized by IR, 1H and 13C NMR. Thermal degradation of the polymers has been studied using a system consisting of a degradation tube, with a condenser for product collection, a gas phase IR cell and a rotary pump, and by thermogravimetry (TG). Product studies were performed by IR, GC–MS, 1H and 13C NMR. Thermal degradations of these two poly(p-substituted phenacylmethacrylates) to give volatile products, begin at about 250°C. The degradation produces anhydride ring structures in the chain at about 260°C. A mechanism of degradation showing the formation of some products is discussed.

Synthesis, characterization and application of a new chelating resin for solid phase extraction, preconcentration and determination of trace metals in some dairy samples by flame atomic absorption spectrometry

In this study, a simple and rapid solid phase extraction/preconcentration procedure was developed for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly(N-cyclohexylacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid) (NCA-co-DVB-co-AMPS) (hereafter CDAP) was synthesized and characterized. The influences of the analytical parameters such as pH of the sample solution, type and concentration of eluent, flow rates of the sample and eluent, volume of the sample and eluent, amount of chelating resin, and interference of ions were examined. The limit of detection (LOD) of analytes were found (3s) to be in the range of 0.65-1.90μgL(-1). Preconcentration factor (PF) of 200 and the relative standard deviation (RSD) of ⩽2% were achieved (n=11). The developed method was applied for determination of analytes in some dairy samples and certified reference materials.

Synthesis and Characterization of New Chelating Resin: Adsorption Study of Copper(II) and Chromium (III) Ions

Acrylamide based monomer, 5-methyl-2-thiozyl methacrylamide (MTMAAm) was synthesized by the reaction of 2-Amino-5-methyl thiazole with methacryloyl chloride in the presence of triethylamine(NR3) at 0–5°C. The monomer MTMAAm was characterized by FT-IR and 1H-and 13C-NMR spectral studies. A new chelating resin, poly(5-methyl-2-thiozyl methacrylamide-co-2-acrylamido-2-methyl-1-propanesulfonic acid-co-divinylbenzene) [MTMAAm/AMPS/DVB] was synthesized. This resin was characterized by FT-IR. In order to determine the adsorption behavior of chelating resin, the adsorption isotherm of Cr(III) and Cu(II) were studied. It was found that the adsorption isotherm of the ions fitted with Langmuir-type isotherms. From the Langmuir equation, the adsorption capacity of chelating resin for Cr(III) and Cu(II) was found to be 7.77 mg g− 1 and 4.27 mg g− 1, respectively. Binding equilibrium constant was calculated to be 0.155 L mg− 1 and 0.106 L mg− 1 for Cu(II) and Cr(III), respectively.

SYNTHESIS, CHARACTERIZATION, AND POLYMERIZATION OF NEW METHACRYLATE ESTERS HAVING PENDANT AMIDE MOIETIES

ABSTRACT In this paper, the synthesis of a number of new methacrylate esters containing amide group are described. The monomers produced from the reaction of corresponding α-chloro-N-aryl or -N-alkyl acetamides with sodium methacrylate were polymerized with AIBN as initiator. The monomers and their polymers were characterized by IR, 1H- and 13C-NMR spectroscopy. The glass transition temperature and thermal decomposition temperature of the polymers were investigated by DSC-50 and TGA-50 thermobalance, respectively. The photocrosslinking properties of the polymers were also discussed.

A new synthesis, characterization and application chelating resin for determination of some trace metals in honey samples by FAAS

In this study, we developed a simple and rapid solid phase extraction (SPE) method for the separation/preconcentration and determination of some trace metals by flame atomic absorption spectrometry (FAAS). A new chelating resin, poly [2-(4-methoxyphenylamino)-2-oxoethyl methacrylate-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid] (MPAEMA-co-DVB-co-AMPS), was synthesized and characterized. This chelating resin was used as a new adsorbent material for determination of Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Pb(II), and Zn(II) ions. The parameters influential on the determination of this trace metals were examined. Under the optimum conditions, the detection limits (DL) of the method for trace metals were found to be (3s) in the range of 0.9-2.2 μg L(-1) (n=21), the preconcentration factor was calculated as 200 and the relative standard deviation was obtained achieved as ⩽2% for n=11. The method was performed for the determination of trace metals in some honey samples and standard reference materials.

Synthesis and Swelling Behavior Analysis of Poly(acrylamidoxime‐co‐2‐acrylamido‐2‐methylpropane Sulfonic Acid) Hydrogels

An investigation of water uptake behavior of a novel poly(acrylonitrile‐co‐2‐acrylamido‐2‐methylpropane sulfonic acid‐co‐N,N′‐methylenebisacrylamide) hydrogel system was carried out with two major objectives. First, the study was initiated to understand the effect of various synthesis conditions, i.e., reaction temperature, initiator content, crosslinker content and pH,on the water absorbency of resulting hydrogels. The second reason was to evaluate these hydrogels after reaction with hydroxylamine hydrochloride to convert the CΞN (nitrile) groups to ‐C˭N‐OH (amidoxime) groups. The optimum amidoximation conditions was determined. The structure of the hydrogels, before and after amidoximation, was analyzed with FTIR and thermal methods. The optimum synthesis temperature, initiator concentration and crosslinker content were found to be 55°C, 1.5 (wt.%) and 1.5 (wt.%), respectively. The equilibrium water uptake increases with an increase in initiator (K2S2O8) concentration and crosslinker (BAAm) content up to 1.5% and then it begins to decrease with a further increase in K2S2O8 and BAAm content. The gel undergoes a drastic volume change in the pH range 5, thus indicating the dissociation of NH groups of acrylamidoxime. The pH increased at 7, and this pH shift may be attributed not only to the acidic region, but also the basic region. A drastic volume change is also observed at pH:10, which may be due to the dissociation of the AMPS SO3H groups. The swelling ratio of the hydrogel sample in sea water, tap water and distilled water are collected. According to the results, the maximum swelling ratio was observed in the distilled water. Finally, the nitrile groups can be easly converted into amidoxime groups via treatment with a solution of hydroxylamine. The swelling behavior of hydrogels are in good agreement, before and after amidoximation.