Preconcentration/separation of some trace metal ions from water samples by a new synthesized chelating resin.

A solid phase extractor, poly(N,N'-dipropionitrile methacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propanesulfonic acid), was synthesized and used for separation/preconcentration of traces of Ni(II), Co(II), Cu(II), Mn(II), Cd(II), Zn(II), and Pb(II) from various water samples prior to their determination by flame atomic absorption spectrometry. The characterization of the synthesized resin was performed by elemental analysis and IR spectrometry. Parameters such as pH, volume and concentration of the eluent, flow rate of the sample solution, sample volume, and interfering ions affecting the column SPE were examined. The optimum pH was found to be 3. The retained metal ions were desorbed from the column with 10 mL of 1 M HCI eluent. A high preconcentration factor, 40-100; low RSD, < or = 2.8%; and low LOD values, < or = 1.74 microg/L, were obtained. The adsorption capacity of the resin was in the range of 6.80-12.4 mg/g for all the elements. The reusability of the resin was excellent. The accuracy of the method was confirmed by analyzing certified reference materials (TMDA-70 Lake Water and SPS-WW1 Batch 111-Wastewater) and spiked water samples. The method was successfully applied to the determination of metal ions in tap, lake, and dam waters.

An Enhanced Photosensitive Sensor Based on ITO/MWCNTs@Polymer Composite@BiVO4 for Quercetin Detection.

The fact that antioxidants scavenge free radicals in the human body and naturally treat many health problems that will occur in this way has increased the consumption of antioxidant-containing foods. However, consumption of artificially prepared antioxidants could cause cancer. Therefore, antioxidants from natural sources are preferred. Quercetin is an antioxidant present in natural samples. In this article, multi-walled carbon nanotubes (MWCNTs), a polymer composite (PC) consisting of a mixture of 15% (by mass) polystyrene (PST), 15% (by mass) polyacrylonitrile (PAN) and 70% (by mass) polyindole (PIN), and semiconducting BiVO4 were used to prepare electrodes, and then a photosensitive ITO/MWCNTs@PC@BiVO4-based sensor was fabricated for quercetin detection. Quercetin was analyzed via the photosensitive ITO/MWCNTs@PC@BiVO4 sensor in 0.1 M phosphate buffered saline (pH 7.4) solutions including various quercetin concentrations. The constructed quercetin sensor displayed a wide linear response between 10 and 200 µM and a limit of detection of 0.133 µM. The developed photosensitive ITO/MWCNTs@PC@BiVO4 demonstrated a high sensitivity (442 µA mM-1 cm-2), good reproducibility (relative standard deviation 3.6%), high selectivity and long-term stability (>49 days) towards quercetin sensing. The photoelectrochemical sensor was then applied to detection of quercetin in black tea as a real-life sample. Our study could lead to the development of novel photosensitive PC polyphenol sensors.

A synthesized ternary polymer composite and its use for SPE of trace metals in Coffee, tea and legumes.

A new synthesized ternary polymer composite, polystyrene/polyacrylonitrile/polyindole (PSt/PAN/PIN), was used as an adsorbent. The structure of synthesized composite was supported by FTIR, BET, X-RD, TGA, SEM and AFM technique. A SPE method with synthesized composite was developed for the preconcentration of chromium, copper, iron, manganese, lead and zinc ions. The adsorption capacity were found in the range of 37.4-56.7 mg g-1. Under the best conditions, the preconcentration factor of method was found as 100. Relative standard deviation was found at ≤ 3.3% (n = 11). The detection limits of analytes were obtained as: 0.9 µg L-1 for Cr(III), 1.2 µg L-1 for Cu(II), 2.0 µg L-1 for Fe(III), 1.4 µg L-1 for Mn(II), 0.9 µg L-1 for Pb(II) and 2.0 µg L-1 for Zn(II). Firstly, this SPE method was applied to certified reference material, and than coffee, tea, legumes. The trace metals was analyzed by flame atomic absorption spectrometry.

Synthesis, spectroscopic characterization, and in vitro antioxidant activity of polyglycidylmethacrylate/polyindole conducting polymer composites.

Polyglycidylmethacrylate/polyindole (PGMA/PIN) conducting polymer composites having five different compositions were prepared chemically using FeCl3 as an oxidant agent in chloroform solution and nitrogen atmosphere at 10°C. The conducting polymer composites were characterized by FTIR spectroscopic technique, scanning electron microscopy (SEM), atomic force microscopy (AFM), and thermogravimetric analysis (TGA) measurements. It is seen that morphological structure of composite is different from PIN and PGMA. PGMA/PIN conducting polymer composite including 50% of PIN has a nonuniform and less homogenous structure compared to the PIN and PGMA polymer. in vitro antioxidant activity such as reduction force, superoxide radical removal activity, hydroxyl radical trapping activity, MDA measurements in Saccharomyces cerevisiae cells of PGMA/PIN conducting polymer composite was investigated. It was observed that the reduction force capacities decreased as PIN content and increased due to the percentage of composite of PGMA content. in vitro studies of synthesized composites have shown us that these compounds possess new antioxidant properties.

Preparation of polyacrylonitrile/polyindole conducting polymer composite and its use for solid phase extraction of copper in a certified reference material.

A polyacrylonitrile/polyindole (PAN/PIN) [50, 50] conducting polymer composite was chemically synthesized using FeCl3 as an oxidizing agent in chloroform solution and nitrogen atmosphere at 10 °C. The formation of the composite was supported by Fourier transform infrared spectroscopy. The morphological properties of the composite were investigated by atomic force microscopy and scanning electron microscopy. The thermal properties of the composite were examined by using thermogravimetric analyses. It was found that the composite had good thermal stability. The conducting polymer composite was used for the first time as an adsorbent for solid phase extraction of Cu (II). The optimum pH was found to be 7. The adsorption and elution shaking times were 5 and 15 min, respectively. The elution was done with 5 mL of 2 mol L-1 HNO3. The accuracy of the developed method was confirmed by analyzing certified reference material (TMDA-70.2 Lake Water).

Spectroscopic characterization of glycidyl methacrylate with acrylonitrile copolymers and monomer reactivity ratios.

We report herein that copolymers containing glycidyl methacrylate (GMA) with acrylonitrile (AN) units were synthesized by free radical solution polymerization technique using benzoyl peroxide as a free radical initiator and 1,4-dioxane as a solvent at 70°C. The copolymerization behavior was studied in different composition with the mole fractions of GMA ranging from 0.20 to 0.80 in the feed and under 10% copolymer conversion. The copolymers were characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and scanning electron microscopy techniques. The thermogravimetric analysis of the copolymers suggest an overall decrease in the thermal stability of the copolymer with decreasing content of GMA in the copolymers. Thermal decomposition activation energies are calculated by the Ozawa method. The copolymer composition was determined by the application of elemental analysis method. The monomer reactivity ratios were estimated by the application of conventional linearization methods, such as Kelen-Tudos (K-T), Fineman-Ross (F-R) methods, and a nonlinear error in variable model (RREVM) method using a computer program, and all results were discussed and compared with the literature.

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.

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.

On-line preconcentration/determination of zinc from water, biological and food samples using synthesized chelating resin and flame atomic absorption spectrometry.

An on-line flow injection pre-concentration-flame atomic absorption spectrometry method was developed to determine trace zinc in water (tap, dam, and well water), biological (hair and nail), and liver samples. As a solid phase extractant, a synthesized new chelating resin, poly(2-thiozylmethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was used. The resin was characterized by Fourier transform infrared spectroscopy, elemental analysis, and surface area by nitrogen sorption. A pre-concentration factor of 40-fold for a sample volume of 12.6 mL was obtained by using the time-based technique. The detection limit for the pre-concentration method was found to be 2.2 µg L(-1). The precision (as RSD,%) for 10 replicate determinations at the 0.04 µg mL(-1) Zn concentration was 1.2%. The calibration graph using the pre-concentration system for zinc was linear with a correlation coefficient of 0.998 in the concentration range from 0.005 to 0.05 µg mL(-1). The applicability and accuracy of the developed method were estimated by the analysis spiked water, biological, liver samples (83-105%), and also certified reference material TMDA-70 (fortified lake water) and SPS-WW1 Batch 111-Wastewater. The results were in agreement with the certified values.

Synthesis/characterization of a new chelating resin and on-line solid phase extraction for the determination of Ag(I) and Pd(II) from water, cream, anode slime and converter samples by flow injection flame atomic absorption spectrometry.

On-line preconcentration procedures for the determination of Ag(I) and Pd(II) by flame atomic absorption spectrometry have been described. A new chelating resin, poly (N,N'-dipropionitrilemethacrylamide-co-divinylbenzene-co-2-acrylamido-2-methyl-1-propane sulfonic acid) was synthesized and used as a new adsorbent material. The resin was characterized by Fourier transform infrared spectroscopy and elemental analysis. Ag(I) was adsorbed on the chelating resin at pH 5.0 and eluted with 1.0 mol L(-1) HNO3. Pd(II) was retained at pH 9.5 and eluted with 1.5 mol L(-1) HCl. The experimental parameters (pH, type and concentration of eluent, flow rates of sample and eluent solutions, elution time and the effect of interfering ions) for both Ag(I) and Pd(II) were investigated in detail. The detection limit for Ag(I) was 2.4 µg L(-1) and the relative standard deviation was 2.9% for 0.2 µg mL(-1) Ag(I). The detection limit for Pd(II) was 1.7 µg L(-1) and the relative standard deviation was 2.8% for 0.3 µg mL(-1) Pd(II). Accuracy was confirmed by analyzing a certified reference material (TMDA-70), recovery studies on real samples and comparison with electrothermal atomic absorption analysis. The proposed methods were successfully applied to the on-line determination of Ag(I) in bottled water, pharmaceutical cream and anode slime samples and Pd(II) in bottled water and catalytic converter samples.

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,