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Publications (5)15.51 Total impact

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    ABSTRACT: A new sorbent S-benzyldithiocarbazate (SBDTC) modified activated carbon (AC-SBDTC) was prepared and studied for preconcentration for trace mercury(II) prior to inductively coupled plasma atom emission spectrometry (ICP-AES). The experimental conditions were optimised with respect to different experimental parameters using both batch and column procedures in detail. The optimum pH value for the separation of Hg(II) on the new sorbent was 3, while the adsorption equilibrium was achieved in less than 5 min. Complete elution of the adsorbed metal ions from the sorbent surface was carried out using 5 mL of 0.25 mol L of HCl and 2% CS(NH2)2. Common coexisting ions did not interfere with the determination. The maximum static adsorption capacity of the sorbent under optimum conditions was found to be 0.55 mmol g. The detection limit of the present method was found to be 0.09 ng mL, and the relative standard deviation (RSD) was lower than 2.0%. The procedure was validated by analysing the certified reference river sediment material (GBW 08301, China), the results obtained were in good agreement with standard values. This sorbent was successfully employed in the separation and preconcentration of trace Hg(II) from the natural water samples yielding 80-fold concentration factor.
    International Journal of Environmental Analytical Chemistry - INT J ENVIRON ANAL CHEM. 01/2011; 91(11):1024-1034.
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    ABSTRACT: Activated carbon was chemically modified with 4-(8-hydroxyquinoline-azo)benzamidine and used for separation and preconcentration of trace amounts of Pb(II) in environmental samples by solid-phase extraction prior to the measurement by inductively coupled plasma atomic emission spectrometry. The effects of pH, shaking time, eluent concentration and volume, sample flow rate and potential interfering ions were studied. Under the optimum conditions, the enrichment factor was 100, the detection limits (3ó) is 0.43ng mL−1, and the relative standard deviations are <2.1% (n = 8). The adsorption capacity of the sorbent is 53.58mg of lead(II) per gram of the material. The sorbent was successfully applied to the preconcentration of trace Pb(II) in the reference materials GBW 08301 (river sediment) and GBW 08302 (Tibet soil). The recovery of lead(II) from Yellow river water, Huangshui water, and tap water is in range of 99.3–101.6%. KeywordsModified activated carbon-Separation/preconcentration-Solid-phase extraction-Lead(II)-Environmental samples-Inductively coupled plasma atomic emission spectrometry
    Microchimica Acta 12/2010; 171(3):225-232. · 3.43 Impact Factor
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    ABSTRACT: A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4. And the adsorbed metal ions could be completely eluted by using 2.0 mL 2.0 mol L(-1) HCl solution. Common coexisting ions did not interfere with the separation and determination of target metal ions. The maximum static adsorption capacity of the sorbent at optimum conditions was found to be 39.8, 39.9, 77.8 and 17.3 mg g(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The detection limits of the method were found to be 0.15, 0.41, 0.27 and 0.36 ng mL(-1) for Cr(III), Cu(II), Fe(III) and Pb(II), respectively. The relative standard deviation (RSD) of the method was lower than 4.0% (n=8). The method was successfully applied for the preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) in natural and certified samples with satisfactory results.
    Analytica chimica acta 10/2009; 649(2):252-7. · 4.31 Impact Factor
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    ABSTRACT: A procedure for separation and preconcentration trace amount of Cu(II), Fe(III) and Pb(II) by 2-((2-aminoethylamino)methyl)phenol-functionalized activated carbon (AC-AMP) packed column has been proposed. Under the optimized conditions (pH 4, flow rate 2.0 mL min(-1)), Cu(II), Fe(III) and Pb(II) were retained on the column, then quantitatively eluted by 2 mL 1 mol L(-1) nitric acid solution and determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The tolerance limits of electrolytes were very high. The adsorption capacity of AC-AMP was found to be 12.1, 67.1, and 16.2 mg g(-1) for Cu(II), Fe(III), and Pb(II), respectively. According to the definition of International Union of Pure and Applied Chemistry, the detection limits (3 sigma) of this method for Cu(II), Fe(III) and Pb(II) were 0.27, 0.41 and 0.16 microg L(-1), respectively. The relative standard deviation under optimum conditions is less than 3.0% (n=11). The proposed method has been validated by analyzing a certified reference material and successfully applied to the preconcentration and determination of Cu(II), Fe(III), and Pb(II) in actual samples with satisfactory results.
    Journal of hazardous materials 10/2009; 175(1-3):710-4. · 4.33 Impact Factor
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    ABSTRACT: 2,6-Pyridine dicarboxylic acid was immobilized on the surface of nanometer-sized silica to prepare a new solid phase extractant which was applied to extract and preconcentrate trace mercury(II) from aqueous solutions prior to the determination by inductively coupled plasma atomic emission spectrometry. The optimization of some analytical parameters affecting the recovery of the analyte such as acidity, shaking time, eluent condition, sample volume, sample flow rate, and influence of potentially interfering ions were investigated. At pH 3, the maximum uptake capacity for mercury(II) was found to be 92mgg−1. Quantitative recovery (≥95%) of mercury (II) was achieved by stripping with 2mL of 0.1molL−1 hydrochloric acid and 3% thiourea. The presence of several metal cations and anions, some of them in high excess, did not interfere with the separation of mercury (II) under optimal conditions. An enrichment factor of 175 and a relative standard deviation less than 3.0% (n = 8) were obtained for mercury(II) determinations. The detection limit (3σ) was 0.09ngmL−1. The method has been validated using certified reference materials (GBW 08303 and GBW 08301), and was applied to the determination of trace mercury(II) in environmental and biological samples with satisfactory results.
    Microchimica Acta 168(1):79-85. · 3.43 Impact Factor