Yazar "Bag, H" seçeneğine göre listele

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    Determination of Cu, Zn and Cd in water by FAAS after preconcentration by baker's yeast (Saccharomyces cerevisiae) immobilized on sepiolite
    (Springer Verlag, 1999) Bag, H; Lale, M; Turker, AR
    By using the adsorbent Saccharomyces cerevisine immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 +/- 0.4% for Cu, 94.2 +/- 0.3% for Zn. and 99.04 +/- 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 mu mol/g for copper, 128 mu mol/g for zinc and 97 mu mol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.
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    Determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry after preconcentration by Escherichia coli immobilized on sepiolite
    (Elsevier Science Bv, 2000) Bag, H; Turker, AR; Lale, M
    A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Escherichia coli immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd by E. coli immobilized on sepiolite were 99.1 +/- 0.6, 98.2 +/- 0.6, 98.1 +/- 0.5, 97.2 +/- 0.8 and 98.2 +/- 0.4% at 95% confidence level, respectively. The adsorption capacity of E. coli immobilized on sepiolite was found as 0.148, 0.064, 0.098, 0.134 and 0.088 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in alloys (NBS SRM 85b). Trace metals have been determined with relative error lower than 10%. (C) 2000 Elsevier Science B.V. All rights reserved.
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    Determination of iron and lead by flame atomic absorption spectrometry after preconcentration with sepiolite
    (Springer Verlag, 1997) Turker, AR; Bag, H; Erdogan, B
    By using a new adsorbent (sepiolite) an adsorption-elution and atomic absorption spectrometric method has been developed for the preconcentration and determination of Fe and Pb. Recoveries of the analytes were 82 +/- 3% for Fe and 91 +/- 2% for Pb at 95% confidence level. For Cu it was only 5 +/- 1%. The recovery of iron could be increased to about 97 +/- 1% by complexing with EDTA, the recovery of copper only to 57 +/- 2%. The optimised method was applied to the determination of lead in metal materials (e.g. brass).
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    Determination of iron and nickel by flame atomic absorption spectrophotometry after preconcentration on Saccharomyces cerevisiae immobilized sepiolite
    (Elsevier Science Bv, 1998) Bag, H; Lale, M; Turker, AR
    Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and determined by flame atomic absorption spectrophotometry (FAAS). Preconcentration studies were conducted by the column method. Effect of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Fe and Ni were 95 +/- 1 and 99.5 +/- 0.1%, respectively, at 95% confidence level. The breakthrough capacities of analytes were also investigated and found to be 0.042 mmol g(-1) for Fe and 0.055 mmol g(-1) for Ni. The proposed method was applied to the determination of iron and nickel in brass (NBS SRM 37e). The detection limit of iron and nickel were found as 0.065 and 0.087 mu g ml(-1), respectively. The direct determination of trace metals by flame atomic absorption spectrometry (FAAS) is limited and difficult because of low concentration and/or matrix interferences. The proposed method is excellent for the determination of trace metal in matrixes, such as metal alloys. (C) 1998 Elsevier Science B.V. All rights reserved.
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    Determination of trace metals in geological samples by atomic absorption spectrophotometry after preconcentration by Aspergillus niger immobilized on sepiolite
    (Japan Soc Analytical Chem, 1999) Bag, H; Turker, AR; Lale, M
    A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01+/-0.06%, 98.8+/-0.5%, 98.0+/-0.4%, 96.4+/-0.8% and 94.8+/-0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.
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    Separation and speciation of Cr(III) and Cr(VI) with Saccharomyces cerevisiae immobilized on sepiolite and determination of both species in water by FAAS
    (Elsevier Science Bv, 2000) Bag, H; Turker, AR; Lale, M; Tunceli, A
    A rapid, sensitive and accurate method for the separation, preconcentration and determination of Cr(III) and Cr(VI) in water samples is described. Chromium species can be separated by biosorption on Saccharomyces cerevisiae immobilized on sepiolite and determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for separation and preconcentration (pH, bed height, flow rate and volume of sample solution) were evaluated. Recovery of the chromium was 96.3 +/- 0.2% at 95% confidence level The breakthrough capacity of the adsorbent was found as 228 mu mol g(-1) for Cr(III). The proposed method was applied successfully to the determination of Cr(III) and Cr(VI) in spiked and river water samples. (C) 2000 Elsevier Science B.V. All rights reserved.