Emre Yavuz

A graphene/Co3O4 nanocomposite as a new adsorbent for solid phase extraction of Pb(II), Cu(II) and Fe(III) ions in various samples

A graphene-based cobalt nanocomposite (G/Co3O4) was synthesized and used for the first time as an effective adsorbent for the preconcentration of the Pb(II), Cu(II) and Fe(III) ions in environmental water and food samples prior to flame atomic absorption detection. The properties of the graphene, Co3O4 and G/Co3O4 nanocomposite were characterized by X-ray diffraction, scanning electron microscopy, and thermal gravimetric analysis. The experimental parameters affecting the solid phase extraction efficiency for analyte ions including sample pH, adsorption and elution contact time, volume and concentration of eluting reagent, sample volume and interfering ions were examined. The adsorption capacity of the G/Co3O4 composite was found to be 58, 77 and 78 mg g−1 for Pb(II), Cu(II) and Fe(III), respectively. The quantitative elution of the adsorbed metal ions was carried out by 2 mL of 2 mol L−1 HNO3. The preconcentration factor of the method was 175. The limit of detection was found to be ≤0.81 μg L−1. The accuracy of the method was studied by analyzing certified reference material (RM 8704 Buffalo River Sediment, SRM 1568a Rice Flour and SPS-WW1 Batch 111-Wastewater) and spiked real samples. The method was applied for the separation and preconcentration of trace metal ions in tap water, wastewater, dam water, well water, kiwi and wheat samples.

Nano sponge Mn2O3 as a new adsorbent for the preconcentration of Pd(II) and Rh(III) ions in sea water, wastewater, rock, street sediment and catalytic converter samples prior to FAAS determinations

In this study, a nano sponge Mn2O3 adsorbent was synthesized and was used for the first time. Various parameters affecting the recovery values of Pd(II) and Rh(III) were examined. The tolerance limits (≥ 90 %) for both Pd(II) and Rh(III) ions were found to be 75,000 mg L(-1) Na(I), 75,000 mg L(-1) K(I), 50,000 mg L(-1) Mg(II) and 50,000 mg L(-1) Ca(II). A 30s contact time was enough for both adsorption and elution. A preconcentration factor of 100 was obtained by using 100mg of the nano sponge Mn2O3. The reusability of the adsorbent was 120 times. Adsorption capacities for Pd(II) and Rh(III) were found to be 42 and 6.2 mg g(-1), respectively. The detection limits were 1.0 µg L(-1) for Pd(II) and 0.37 µg L(-1) for Rh(III) and the relative standard deviations (RSD, %) were found to be ≤ 2.5%. The method was validated by analyzing the standard reference material, SRM 2556 (Used Auto Catalyst Pellets) and spiked real samples. The optimized method was applied for the preconcentration of Pd(II) and Rh(III) ions in water (sea water and wastewater), rock, street sediment and catalytic converter samples.

Nanosized spongelike Mn3O4 as an adsorbent for preconcentration by vortex assisted solid phase extraction of copper and lead in various food and herb samples

In this paper, a nanosized spongelike Mn3O4 was synthesized and used for the first time as an effective adsorbent for vortex-assisted separation and preconcentration of lead and copper from various food samples. Copper and lead were determined by flame atomic absorption spectrometry. The characterization of the nanosized spongelike Mn3O4 was performed by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, Brunauer, Emmett and Teller surface area and zeta potential measurement. The contact times for both adsorption and elution were only 3min. Under the optimized conditions, detection limits for copper and lead were found to be 2.6μgL(-1) and 3.0μgL(-1), respectively. The relative standard deviations were found to be ⩽3.2%. The accuracy of the method was confirmed by analyzing the standard reference materials (BCR-482 Licken and SRM 1573a Tomato Leaves) and spiked real food and herb samples.

Ultralayered Co3O4 as a new adsorbent for preconcentration of Pb(II) from water, food, sediment and tobacco samples

In this study, ultralayered Co3O4 adsorbent was synthesized and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The surface area of the solid material was found to be 75.5m(2)g(-1) by BET method. The ultralayered Co3O4 was used for the first time as an effective adsorbent for the preconcentration of the Pb(II) ions in various samples prior to flame atomic absorption detection. Analytical parameters affecting the solid phase extraction of Pb(II) such as pH, adsorption and elution contact time, eluent volume and concentration, sample volume and common matrix ions were investigated. The recovery values for Pb(II) were found to be ≥ 92% even in the presence of 75,000 mg L(-1) Na(I), 75,000 mg L(-1) K(I), and 75,000 mg L(-1) Ca(II) ions. 10s vortexing time was enough for both adsorption and elution contact times. The elution was easily made with 2 mL of 2.0 mol L(-1) HNO3. The reusability (170 cycles) and adsorption capacity (35.5 mg g(-1)) of ultralayered Co3O4 were excellent. The preconcentration factor of the method and detection limit were found to be 175 and 0.72 µg L(-1), respectively. The described method was validated with certified reference material (RM 8704 Buffalo River Sediment, BCR-482 Licken and SPS-WW1 Batch 111-Wastewater) and spiked real samples. It was also applied for the preconcentration of Pb(II) ions in various water (well water, mineral water, waste water and sea water), food (cauliflower and barley), street sediment and tobacco samples.

Zirconium-based highly porous metal-organic framework (MOF-545) as an efficient adsorbent for vortex assisted-solid phase extraction of lead from cereal, beverage and water samples

In this study, zirconium-based highly porous metal-organic framework, MOF-545, was synthesized and characterized. The surface area of MOF-545 was found to be 2192m2/g. This adsorbent was used for the first time as an adsorbent for the vortex assisted-solid phase extraction of Pb(II) from cereal, beverage and water samples. Lead in solutions was determined by FAAS. The optimal experimental conditions were as follows: the amount of MOF-545, 10mg; pH of sample, 7; adsorption and elution time, 15min; and elution solvent, 2mL of 1molL-1HCl. Under the optimal conditions of the method, the limit of detection, preconcentration factor and precision as RSD% were found to be 1.78μgL-1, 125 and 2.6%, respectively. The adsorption capacity of the adsorbent for lead was found to be 73mgg-1. The method was successfully verified by analyzing two certified reference materials (BCR-482 Lichen and SPS-WW1 Batch 114) and spiked chickpea, bean, wheat, lentil, cherry juice, mineral water, well water and wastewater samples.

Ionic liquid coated carbon nanospheres as a new adsorbent for fast solid phase extraction of trace copper and lead from sea water, wastewater, street dust and spice samples.

In this study a new adsorbent, ionic liquid (1,8-naphthalene monoimide bearing imidazolium salt) coated carbon nanospheres, was synthesized for the first time and it was used for the solid phase extraction of copper and lead from various samples prior to determination by flame atomic absorption spectrometry. The ionic liquid, carbon nanospheres and ionic liquid coated carbon nanospheres were characterized by using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, (1)H NMR and (13)C NMR, Brunauer, Emmett and Teller surface area and zeta potential measurements. Various parameters for method optimization such as pH, adsorption and elution contact times, eluent volume, type and concentration, centrifuge time, sample volume, adsorption capacity and possible interfering ion effects were tested. The optimum pH was 6. The preconcentration factor, detection limits, adsorption capacity and precision (as RSD%) of the method were found to be 300-fold, 0.30µgL(-1), 60mgg(-1) and 1.1% for copper and 300-fold, 1.76µgL(-1); 50.3mgg(-1) and 2.2%, for lead, respectively. The effect of contact time results showed that copper and lead were adsorbed and desorbed from the adsorbent without vortexing. The equilibrium between analyte and adsorbent is reached very quickly. The method was rather selective for matrix ions in high concentrations. The accuracy of the developed method was confirmed by analyzing certified reference materials (LGC6016 Estuarine Water, Reference Material 8704 Buffalo River Sediment, and BCR-482 Lichen) and by spiking sea water, wastewater, street dust and spice samples.

Spectrophotometric determination of basic fuchsin from various water samples after vortex assisted solid phase extraction using reduced graphene oxide as an adsorbent.

In this study, a fast and simple vortex assisted solid phase extraction method was developed for the separation/preconcentration of basic fuchsin in various water samples. The determination of basic fuchsin was carried out at a wavelength of 554 nm by spectrophotometry. Reduced graphene oxide which was used as a solid phase extractor was synthesized and characterized by X-ray diffraction, scanning electron microscopy and the Brunauer, Emmett and Teller. The optimum conditions are as follows: pH 2, contact times for adsorption and elution of 30 s and 90 s, respectively, 10 mg adsorbent, and eluent (ethanol) volume of 1 mL. The effects of some interfering ions and dyes were investigated. The method was linear in the concentration range of 50-250 μg L(-1). The adsorption capacity was 34.1 mg g(-1). The preconcentration factor, limit of detection and precision (RSD, %) of the method were found to be 400, 0.07 μg L(-1) and 1.2%, respectively. The described method was validated by analyzing basic fuchsin spiked certified reference material (SPS-WW1 Batch 114-Wastewater) and spiked real water samples.

FAAS determination of Ag(I) in water, anode slime, rock and cream samples by solid phase extraction method based on sepabeads SP207/5-(p-dimethylaminobenzylidene) rhodanine combination

Um metodo simples e confiavel para separacao/pre-concentracao de Ag(I) utilizando o reagente 5-(p-dimetilaminobenzilideno) rodanina e o adsorvente Sepabeads SP207 seguido de sua determinacao por espectrometria de absorcao atomica com chama (FAAS) foi desenvolvido. As condicoes ideais do metodo para a separacao/preconcentracao de Ag(I) foram estabelecidas em pH 4,0 com fator de preconcentracao de 200. Os limites de deteccao e quantificacao do metodo foram 0,13 e 0,44 µg L -1 , respectivamente. Os valores de desvio padrao relativo e capacidade de adsorcao foram de 1,0% e 5,40 mg g -1 , respectivamente. A recuperacao de Ag(I) em pH 4,0 com 50 mg de resina foi quantitativa e sem interferencias causadas por cations de metais alcalinos e alcalino-terrosos, em concentracoes de ate 10000 µg mL -1 , com excecao de K + . A exatidao do metodo foi avaliada analisando-se o material de referencia certificado TMDA-70 agua de lago e por experimentos de adicao e recuperacao. O metodo foi aplicado na determinacao de Ag(I) em amostras de agua da torneira, agua mineral, agua de mar, lama anodica, rocha e creme. A simple and reliable method for separation/preconcentration of Ag(I) by using 5-(p-dimethylaminobenzylidene) rhodanine reagent and Sepabeads SP207 adsorbent prior to its determination by flame atomic absorption spectrometry (FAAS) was developed. The optimum pH of the method for separation/preconcentration of Ag(I) was found to be 4.0. The preconcentration factor was 200. The limits of detection and quantification of the method were 0.13 and 0.44 µg L -1 , respectively. Relative standard deviation and adsorption capacity were 1.0% and 5.40 mg g -1 , respectively. The recovery of Ag(I) at pH 4.0 with 50 mg resin was quantitative without interferences caused by alkaline and alkaline earth cations, presenting concentrations of up to 10000 µg mL -1 , except for K + . The accuracy of the method was checked by analysing TMDA-70 lake water certified reference material and by addition-recovery experiments. The method was applied for the determination of Ag(I) in tap water, mineral water, sea water, anode slime, rock and cream samples.

Dispersive Solid-Phase Extraction of Rhodium from Water, Street Dust, and Catalytic Converters Using a Cellulose–Graphite Oxide Composite

ABSTRACT A cellulose–graphite oxide composite was synthesized and characterized as an adsorbent for dispersive solid-phase extraction of rhodium from various samples before atomic absorption detection. The pH, adsorbent volume, centrifugation time and rate, eluent concentration, volume and type, adsorption and elution contact time, sample volume, and matrix interferences were optimized. The developed method is simple, rapid, and inexpensive. The tolerance limits for rhodium were 10,000 mg L−1 sodium, 25,000 mg L−1 potassium, 10,000 mg L−1 magnesium, and 20,000 mg L−1 calcium. The recovery for rhodium exceeded 95%. Elution was performed with 10 mL of 2.5 mol L−1 H2SO4. The adsorption and elution contact times were 30 and 60 s, respectively. The detection limit of the method for rhodium was 5.4 µg L−1 and the precision as the relative standard deviation was 1.6%. A certified reference material 2556 (used auto catalyst pellets) and fortified samples were analyzed to evaluate the accuracy of the method. The optimized method was used for the preconcentration of rhodium from tap water, well water, wastewater, seawater, catalytic converters, and street dust.

Novel Chelating Resin for Solid Phase Extraction of Metals in Certified Reference Materials and Waters

ABSTRACT A new chelating resin, poly(diacetonitrile methacrylamide-co-divinylbenzene-co-vinylimidazole), was synthesized and characterized by infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, and elemental analysis. The novel resin was used for the first time as a chelating adsorbent for the preconcentration of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn from various samples by flame atomic absorption spectrometry. The adsorption capacities of the resin were 29.3, 31.6, 29.3, 27.3, 35.5, 31.7, 39.8, and 32.3 mg g−1 for Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn, respectively. The detection limits of the metal ions were from 0.42 to 3.21 µg L−1. A preconcentration factor of 30 for all metal ions was obtained. The precision of the method as the relative standard deviation was less than or equal to 2.6%. The described method was validated with certified reference materials and fortified real samples. The method was used for the determination of the analytes in well water and wastewater.