224 research outputs found

    Chromium speciation using an aminated amberlite XAD-4 resin column combined with microsample injection-flame atomic absorption spectrometry

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    Amberlite XAD-4 resin (AXAD-4) was chemically modified to an aminated Amberlite XAD-4 (AAXAD-4) resin and characterized by infrared spectroscopy. AAXAD-4 resin was used as an efficient solid phase for the preconcentration and speciation of Cr(III) and Cr(VI) ions by column technique. The concentration of chromium species was determined by microsample injection system-flame atomic absorption spectrometer (MIS-FAAS). Selective retention of Cr(III) ions was achieved at pH 8.0 and eluted using 1.0 mL of 3.0 mol L–1 HCl and 1.0 mL of 2.0 mol L–1 NaOH, successively, at the flow rate of 5.0 mL min–1. The maximal sorption capacity of AAXAD-4 resin for Cr(III) ions was found to be 67.0 mg g–1. The limit of detection (LOD) and limit of quantitation (LOQ) for Cr(III) ions were found to be 0.041 and 0.131 µg L–1, respectively, with preconcentration factor (PF) of 375 and relative standard deviation (RSD) of 3.75% (n = 11). The method was validated using certified reference materials (CRMs) and successfully applied to the real samples, spiked with Cr(III) and Cr(VI) ions. © 2018 Slovensko Kemijsko Drustvo. All rights reserved

    Sorbent extraction of some metal ions on a gas chromatographic stationary phase prior to their flame atomic absorption determinations

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    An enrichment/separation system for atomic absorption spectrometric determinations of Cu(II), Fe(III), Ni(II) and Co(II) has been established. The procedure is based on the adsorption of the analytes as calmagite chelates on Chromosorb-102. The effects of some parameters including pH, amount of ligand, salt matrix, flow rates of sample and eluent solutions were investigated. Under optimized conditions, the relative standard deviation of the combined method of sample treatment, preconcentration and determination with FAAS (N=5) is generally lower than 5%. The limit of detection (3σ) was between 6.0-112. 9 μg/L. The results were used for preconcentration of analytes from some sodium and ammonium salt

    Determination of trace metals in waters by FAAS after enrichment as metal-HMDTC complexes using solid phase extraction

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    A method has been described for the determination of Cu(II), Pb(II), Ni(II), Cd(II), Mn(II) and Fe(III) by flame atomic absorption spectrometry (FAAS) after preconcentration on Amberlite XAD-16 resin, using hexamethyleneammonium-hexamethylenedithiocarbamate (HMA-HMDTC) as a chelating agent, and NH3/NH4Cl buffer solution (pH 9). Influences of various analytical parameters such as pH, concentration of nitric acid, amount of analytes, diverse ions and sample volume were investigated. The relative standard deviation (RSD) and the detection limit (LOD) were found in the range of 0.8-2.9% and 0.006-0.277 mug/mL, respectively. Recoveries obtained by the column method were quantitative (>95%) at optimum conditions. The method was applied to the determination of some metal ions in seawater and wastewater samples. A high preconcentration factor (about 150 for seawater and 75 for wastewater samples) and simplicity are the main advantages of this suggested method

    Extractable trace metals content of dust from vehicle air filters as determined by sequential extraction and flame atomic absorption spectrometry

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    A modified four-step sequential extraction procedure developed within the Standards, Measurement, and Testing Program (formally the Community Bureau of Reference) of the European Commission was applied to determine the distribution of Cd, Cu, Fe, and Mn in air filter dust samples collected from vehicles. The four fractions were acid-soluble, reducible, oxidizable, and residual. These fractions have the advantage of providing better insight into the mechanism of association of metals in the dust. The determination of trace metals in dust samples was performed by flame atomic absorption spectrometry. The results obtained after applying the sequential extraction scheme indicated that Cu was the most abundant metal in the organic and residual fractions of the dust matrix. Fe was found mainly in the residual fraction, and the major amounts of Mn and Cd were present in the acidsoluble and bound-to-carbonate fraction. The mean values of Cd, Cu, Fe, and Mn were found to be 15.58, 33.54,1625, and 180 μg/g, respectively. The results obtained are in agreement with data reported in the literature

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    Determination of copper, iron, lead, cadmium, cobalt and nickel by atomic absorption spectrometry in baking powder and baking soda samples after preconcentration and separation

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    The contents of copper, iron, lead, cadmium, cobalt and nickel in baking powder and baking soda samples have been determined by atomic absorption spectrometry after separation and preconcentration. Two different separation/preconcentration methods including APDC-Chromosorb 102 solid phase extraction method and Ce(OH)(4) coprecipitation method have been used for this purpose. The effects of main components of the baking soda and powder were examined. The methods were successfully applied for the determinations of Cu, Fe, Pb, Cd, Co and Ni in the baking soda and baking powder samples purchased from the local markets in Kayseri City-Turkey (recoveries greater than 95%). The results found the two preconcentration methods generally agree with each other. The levels of the analytes in the samples were below the allowed limit values given by Turkish Authorities

    Simultaneous preconcentration of trace metals in environmental samples using amberlite XAD-2010/8-hydroxyquinoline system

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    A simple and sensitive system for simultaneous preconcentration of Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Pb(II) and Cd(II) at trace level by flame atomic absorption spectrometry (FAAS) is proposed. Amberlite XAD-2010 packed in a column was used as sorbent. Analyte ions were sorbed in the column as their 8-hydroxyquinoline chelates; they could then be eluted by 1 mol L -1 HNO3 in acetone. The analytical conditions including pH, amounts of 8-hydroxyquinoline, sample volume etc. on the quantitative recoveries of the analytes were investigated. The effects of the concomitants ions on the recoveries of the analytes column were also studied. The detection limits, corresponding to three times the standard deviation of the blank, were found to be in the range of 0.10-0.40 μg L-1. The accuracy of the procedure was measured by analyte determinations in certified reference materials (CRM NIES No. 7 Tea Leaves and TMDW-500 Drinking Water). The applications of the presented system were performed by the analysis of some environmental samples including water samples

    Applying magnesium hydroxide coprecipitation method for trace analysis to dialysis concentrate

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    A magnesium hydroxide coprecipitation technique for determination of Cd. Co, Cu, Mn, Ni in dialysis concentrate is described. The analytes are concentrated from 10 ml of dialysis concentrate into 1 ml of 1 M HNO3 and subsequently determined by graphite furnace atomic absorption spectrometry. Coprecipitation parameters and matrix effects are discussed. The precision, based on replicate analysis; is around 5% for the analytes, and recovery is quantitative, based on analysis of spiked samples and solutions including matrix components. (C) 1998 Elsevier Science B.V. All rights reserved

    Determination of some trace metals in water and sediment samples by flame atomic absorption spectrometry after coprecipitation with cerium (IV) hydroxide

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    A cerium(IV) hydroxide coprecipitation method was developed for the determination of some trace elements (Cu, Co, Pb, Cd, Ni) in aqueous solutions, water and sediment samples by flame atomic absorption spectrometry (AAS). Several parameters governing the efficiency of the coprecipitation method were evaluated including pH of sample solution, amount of carrier element, volume of sample solution and the effect of possible matrix ions The procedure was validated by the analysis of GBW 07309 standard reference material sediment and by use of a method based on a solid phase extraction. © 2002 Elsevier Science B.V. All rights reserved
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