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Satoshi Kaneco - One of the best experts on this subject based on the ideXlab platform.
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Preconcentration of trace silver with yeast for river water analysis.
Annali di chimica, 2002Co-Authors: Kiyohisa Ohta, Syn-ichi Itoh, Satoshi Kaneco, Kanako Saruma, Tohru Suzuki, Aleya BegumAbstract:A new Preconcentration method with yeast is presented. The method was evaluated for the determination of trace silver in river waters by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for Preconcentration of silver was 1.75 mg ml-1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 25 degrees C. Under optimal conditions, silver in aqueous sample was concentrated to 6.9-fold by yeast. The detection limit was 4.6 pg ml-1 (3S/N) for silver in river water. The yeast Preconcentration method was applied to the determination of silver in river waters. The recovery of spiked silver was in the range of 89 to 110%. By the Preconcentration, it was found that ultra trace silver in river waters could be determined without interferences of matrix elements, after only the cultivation and with no chemical treatment.
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Preconcentration of trace copper with yeast for river water analysis.
Talanta, 2001Co-Authors: Kiyohisa Ohta, Hideo Tanahasi, Suzuki Toru, Satoshi KanecoAbstract:Abstract A new Preconcentration method with yeast is presented. The method was evaluated for the determination of trace copper in river water by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for Preconcentration of copper was 3.5 mg ml−1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 40°C. Under optimal conditions, copper in aqueous sample was concentrated about seven-fold by yeast. The detection limit was 85 pg ml−1 (3S/N) for copper in river waters. The yeast Preconcentration method was applied to the determination of copper in river waters. The recovery of spiked copper was in the range of 93–100%. By the Preconcentration, it was found that ultra trace copper in river waters could be determined without interferences of matrix elements, after only the cultivation and no chemical treatment.
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Determination of nickel in water by electrothermal atomic absorption spectrometry with Preconcentration on a tungsten foil
Mikrochimica Acta, 1998Co-Authors: Kiyohisa Ohta, Keita Ishida, Syn-ichi Itoh, Satoshi Kaneco, Takayuki MizunoAbstract:A Preconcentration method for nickel in waters involving adsorption on tungsten foil, followed by electrothermal atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer is described. The most suitable pH for nickel adsorption was 5 and the optimum immersion time was 2 min. Severe interferences from co-existing elements (Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn) on the Ni AA signal were observed. Under optimal conditions, the Preconcentration of nickel on W foil could eliminate interferences from these elements. The detection limit of nickel by Preconcentration-ETAAS was 0.1 ng/ml (3S/N). The method with Preconcentration on tungsten foil was applied to the determination of nickel in river water. The recovery of spiked nickel was 93-102%. The tungsten foil Preconcentration method is sensitive, simple, and convenient. This adsorption method can be utilized in in situ-sampling of ultra-trace nickel in environmental samples (water). Furthermore, after sampling it is easy to carry and store the W-foil without contamination for long time
Kiyohisa Ohta - One of the best experts on this subject based on the ideXlab platform.
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Preconcentration of trace silver with yeast for river water analysis.
Annali di chimica, 2002Co-Authors: Kiyohisa Ohta, Syn-ichi Itoh, Satoshi Kaneco, Kanako Saruma, Tohru Suzuki, Aleya BegumAbstract:A new Preconcentration method with yeast is presented. The method was evaluated for the determination of trace silver in river waters by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for Preconcentration of silver was 1.75 mg ml-1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 25 degrees C. Under optimal conditions, silver in aqueous sample was concentrated to 6.9-fold by yeast. The detection limit was 4.6 pg ml-1 (3S/N) for silver in river water. The yeast Preconcentration method was applied to the determination of silver in river waters. The recovery of spiked silver was in the range of 89 to 110%. By the Preconcentration, it was found that ultra trace silver in river waters could be determined without interferences of matrix elements, after only the cultivation and with no chemical treatment.
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Preconcentration of trace copper with yeast for river water analysis.
Talanta, 2001Co-Authors: Kiyohisa Ohta, Hideo Tanahasi, Suzuki Toru, Satoshi KanecoAbstract:Abstract A new Preconcentration method with yeast is presented. The method was evaluated for the determination of trace copper in river water by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for Preconcentration of copper was 3.5 mg ml−1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 40°C. Under optimal conditions, copper in aqueous sample was concentrated about seven-fold by yeast. The detection limit was 85 pg ml−1 (3S/N) for copper in river waters. The yeast Preconcentration method was applied to the determination of copper in river waters. The recovery of spiked copper was in the range of 93–100%. By the Preconcentration, it was found that ultra trace copper in river waters could be determined without interferences of matrix elements, after only the cultivation and no chemical treatment.
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Determination of nickel in water by electrothermal atomic absorption spectrometry with Preconcentration on a tungsten foil
Mikrochimica Acta, 1998Co-Authors: Kiyohisa Ohta, Keita Ishida, Syn-ichi Itoh, Satoshi Kaneco, Takayuki MizunoAbstract:A Preconcentration method for nickel in waters involving adsorption on tungsten foil, followed by electrothermal atomic absorption spectrometry (ETAAS) with a tungsten tube atomizer is described. The most suitable pH for nickel adsorption was 5 and the optimum immersion time was 2 min. Severe interferences from co-existing elements (Al, Ca, Cu, Fe, K, Mg, Na, Pb and Zn) on the Ni AA signal were observed. Under optimal conditions, the Preconcentration of nickel on W foil could eliminate interferences from these elements. The detection limit of nickel by Preconcentration-ETAAS was 0.1 ng/ml (3S/N). The method with Preconcentration on tungsten foil was applied to the determination of nickel in river water. The recovery of spiked nickel was 93-102%. The tungsten foil Preconcentration method is sensitive, simple, and convenient. This adsorption method can be utilized in in situ-sampling of ultra-trace nickel in environmental samples (water). Furthermore, after sampling it is easy to carry and store the W-foil without contamination for long time
Cesar Ricardo Teixeira Tarley - One of the best experts on this subject based on the ideXlab platform.
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preparation of new ion selective cross linked poly vinylimidazole co ethylene glycol dimethacrylate using a double imprinting process for the Preconcentration of pb 2 ions
Journal of Colloid and Interface Science, 2015Co-Authors: Cesar Ricardo Teixeira Tarley, Marcela Zanetti Corazza, Bruna Fabrin Somera, Mariana Gava SegatelliAbstract:Abstract A new ion-selective cross-linked poly(vinylimidazole- co -ethylene glycol dimethacrylate) prepared via a double-imprinting process was developed for the recognition and Preconcentration of Pb 2+ from water samples. The sorbent was characterized by FT-IR, SEM, TGA and textural data. The maximum dynamic sorption capacity of Pb 2+ was 42.04 mg Pb 2+ g −1 of the double-imprinted polymer. The sorption kinetics data were described by a pseudo-second-order model. The double-imprinted polymer exhibited a higher sorption efficiency of Pb 2+ than the blank polymer (non-imprinted polymer). The Preconcentration procedure involved the loading of a Pb 2+ solution at pH 7.25 through 40.0 mg of the double-imprinted polymer packed in a mini-column at 5.0 mL min −1 . The selective efficiency of proposed method for the Pb 2+ Preconcentration was assured by competitive sorption using different proportions of Pb 2+ /cations and Pb 2+ /anions. An analytical curve was obtained in the range 0.0–300.0 μg L −1 ( r = 0.999) and a limit of detection of 2.46 μg L −1 was obtained. The Preconcentration factor was found to be 21, the consumptive index 0.95 mL and the concentration efficiency 5.25 min −1 . The Preconcentration method was successfully applied to the Pb 2+ ions determination in different kinds of water samples with high recovery values (91.3–108.9%).
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solid phase extraction system for pb ii ions enrichment based on multiwall carbon nanotubes coupled on line to flame atomic absorption spectrometry
Talanta, 2007Co-Authors: Adriano Francisco Barbosa, Mariana Gava Segatelli, Arnaldo Cesar Pereira, Antonio De Santana Santos, Lauro T Kubota, Pedro Orival Luccas, Cesar Ricardo Teixeira TarleyAbstract:Abstract The present paper proposes the application of multiwall carbon nanotubes (MWCNTs) as a solid sorbent for lead Preconcentration using a flow system coupled to flame atomic absorption spectrometry. The method comprises the Preconcentration of Pb (II) ions at a buffered solution (pH 4.7) onto 30 mg of MWCNTs previously oxidized with concentrated HNO3. The elution step is carried out with 1.0 mol L−1 HNO3. The effect of the experimental parameters, including sample pH, sampling flow rate, buffer and eluent concentrations were investigated by means of a 24 full factorial design, while for the final optimization a Doehlert design was employed. Under the best experimental conditions the Preconcentration system provided detection and quantification limits of 2.6 and 8.6 μg L−1, respectively. A wide linear range varying from 8.6 up to 775 μg L−1 (r > 0.999) and the respective precision (relative standard deviation) of 7.7 and 1.4% for the 15 and 200 μg L−1 levels were obtained. The characteristics obtained for the performance of the flow Preconcentration system were a Preconcentration factor of 44.2, Preconcentration efficiency of 11 min−1, consumptive index of 0.45 mL and sampling frequency estimated as 14 h−1. Preconcentration studies of Pb (II) ions in the presence of the majority foreign ions tested did not show interference, attesting the good performance of MWCNTs. The accuracy of the method was assessed from analysis of water samples (tap, mineral, physiological serum and synthetic seawater) and common medicinal herbs submitted to the acid decomposition (garlic and Ginkgo Biloba). The satisfactory recovery values obtained without using analyte addition method confirms the feasibility of this method for Pb (II) ions determination in different type of samples.
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use of modified rice husks as a natural solid adsorbent of trace metals characterisation and development of an on line Preconcentration system for cadmium and lead determination by faas
Microchemical Journal, 2004Co-Authors: Cesar Ricardo Teixeira Tarley, Sergio Luis Costa Ferreira, Marco Aurelio Zezzi ArrudaAbstract:Abstract The use of rice husks as an alternative adsorbent in an on-line Preconcentration system for Cd (II) and Pb (II) determination by flame atomic absorption spectrometry (FAAS) is described. The potential of rice husks as a natural adsorbent was evaluated as a material modified with 0.75 mol l −1 NaOH solution and in the unmodified form. For this task, several techniques such as spectroscopy and thermogravimetry were used for elucidation of possible functional groups responsible for the uptake of Cd (II) and Pb (II). Furthermore, based on adsorption studies and adsorption isotherms applied to the Langmuir model, it was possible to verify that modified rice husks present a higher adsorption capacity for both metals. After establishing this material as a promising natural adsorbent, it was used for on-line Preconcentration of Cd (II) and Pb (II) metals. The multivariate optimisation of chemical and flow variables was performed by using a full factorial design (2 4 ) including the following factors: Preconcentration time, Preconcentration flow rate, concentration and volume of eluent. The optimum pH values used for on-line Preconcentration were taken from prior univariate experiments. Under optimised conditions for Cd (II) determination (4 min of Preconcentration at a 6 ml min −1 Preconcentration flow rate, in which comprises 24 ml of Preconcentration volume, 200 μl elution volume and 1.0 mol l −1 HNO 3 solution as eluent), the system achieved a detection limit of 1.14 μg l −1 and an enrichment factor of 72.4. Similar conditions were used for Pb (II) determination (4 min of Preconcentration, 6 ml min −1 Preconcentration flow rate, 300 μl elution volume and 1.0 mol l −1 HNO 3 solution as eluent) from which a detection limit of 14.1 μg l −1 and enrichment factor of 46.0 were achieved. Also, rice husks have been shown to be a homogeneous and stable adsorbent in which more than 100 Preconcentration/elution cycles provide a relative standard deviation (RSD) of less than 6.0% on the analytical signal. The satisfactory accuracy of the method developed was obtained by using spiked water samples (mineral water and lake water) and spiked red wine samples. These values were confirmed by electrothermal atomic absorption spectrometry (ETAAS). The certified reference material [pig kidney (CRM 186)] and the reference material [beech leaves (CRM 100)] were also used.
Homayon Ahmad Panahi - One of the best experts on this subject based on the ideXlab platform.
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a new functionalized resin and its application in flame atomic absorption spectrophotometric determination of trace amounts of heavy metal ions after solid phase extraction in water samples
Microchemical Journal, 2013Co-Authors: Sadegh Khazaeli, Nadia Nezamabadi, Mohammad Rabani, Homayon Ahmad PanahiAbstract:Abstract In this work, Amberlite XAD-4 functionalized with salicylic acid through an azo linkage ( N N ) was synthesized and used as a new chelating resin for Preconcentration of Pb(II), Cu(II), Ni(II), Co(II), and Zn(II) in water samples. The resin was characterized by scanning electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and thermogravimetric analysis. Determination of the metal ions was carried out by flame atomic absorption spectrophotometry. Metal ion sorption equilibria were reached within 30 min. The preconcentraion factor was 50 for a 500 mL sample. The sorbed metal ions were eluted by 10 mL of 0.5 M HNO3 within 10 min with the desorption recovery of ≥ 90%. This new method gave a good accuracy in batch system as indicated by the recovery of ≥ 93% for the extraction of all metal ions and R.S.D. less than 1.4% (n = 5). The detection limits for Pb(II), Cu(II), Ni(II), Co(II) and Zn(II) were 0.15, 0.18, 0.18, 0.21, and 0.19 μg L− 1, respectively.
Hideo Tanahasi - One of the best experts on this subject based on the ideXlab platform.
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Preconcentration of trace copper with yeast for river water analysis.
Talanta, 2001Co-Authors: Kiyohisa Ohta, Hideo Tanahasi, Suzuki Toru, Satoshi KanecoAbstract:Abstract A new Preconcentration method with yeast is presented. The method was evaluated for the determination of trace copper in river water by graphite furnace atomic absorption spectrometry (GFAAS). A suitable cultivation bed for Preconcentration of copper was 3.5 mg ml−1 2-ammonium hydrogen phosphate. The optimal cultivation time and temperature were 2 h and 40°C. Under optimal conditions, copper in aqueous sample was concentrated about seven-fold by yeast. The detection limit was 85 pg ml−1 (3S/N) for copper in river waters. The yeast Preconcentration method was applied to the determination of copper in river waters. The recovery of spiked copper was in the range of 93–100%. By the Preconcentration, it was found that ultra trace copper in river waters could be determined without interferences of matrix elements, after only the cultivation and no chemical treatment.