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Shang-da Huang - One of the best experts on this subject based on the ideXlab platform.
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Direct and simultaneous determination of arsenic, manganese, cobalt and nickel in urine with a multielement graphite furnace Atomic Absorption Spectrometer.
Talanta, 2004Co-Authors: Man-ching Hsiang, Yu-hsiang Sung, Shang-da HuangAbstract:Abstract A simple method was developed for the direct and simultaneous determination of arsenic (As), manganese (Mn), cobalt (Co), and nickel (Ni) in urine by a multi-element graphite furnace Atomic Absorption Spectrometer (Perkin–Elmer SIMAA 6000) equipped with the transversely heated graphite atomizer and longitudinal Zeeman-effect background correction. Pd was used as the chemical modifier along with either the internal furnace gas or a internal furnace gas containing hydrogen and a double stage pyrolysis process. A standard reference material (SRM) of Seronorm™ Trace Elements in urine was used to confirm the accuracy of the method. The optimum conditions for the analysis of urine samples are pyrolysis at 1350 °C (using 5% H2 v/v in Ar as the inter furnace gas during the first pyrolysis stage and pure Ar during the second pyrolysis stage) and atomization at 2100 °C. The use of Ar and matrix-free standards resulted in concentrations for all the analytes within 85% (As) to 110% (Ni) of the certified values. The recovery for As was improved when mixture of 5% H2 and 95% Ar (v/v) internal furnace gas was applied during the first step of a two-stage pyrolysis at 1350 °C, and the found values of the analytes were within 91–110% of the certified value. The recoveries for real urine samples were in the range 88–95% for these four elements. The detection limits were 0.78 μg l−1 for As, 0.054 μg l−1 for Mn, 0.22 μg l−1 for Co, and 0.35 μg l−1 for Ni. The upper limits of the linear calibration curve are 60 μg l−1 (As); 12 μg l−1 (Mn); 12 μg l−1 (Co) and 25 μg l−1 (Ni), respectively. The relative standard deviations (R.S.D.s) for the analysis of SRM were 2% or less. The R.S.D.s of a real urine sample are 1.6% (As), 6.3% (Mn), 7.0% (Ni) and 8.0% (Co), respectively.
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Simultaneous determination of manganese, iron and cobalt in copper with a multi-element graphite furnace Atomic Absorption Spectrometer
Spectrochimica Acta Part B: Atomic Spectroscopy, 2003Co-Authors: Chun-hao Chiu, Yu-hsiang Sung, Shang-da HuangAbstract:Abstract A simple method was developed for the determination of trace metals (Mn, Fe and Co) in copper simultaneously using a multi-element graphite furnace Atomic Absorption Spectrometer (Perkin-Elmer SIMAA6000) equipped with a transversely heated graphite atomizer. Copper was dissolved in nitric acid before analysis using a microwave digestion system. Pd(NO 3 ) 2 with the special gas (5% H 2 in Ar) was used as the chemical modifier. The accuracy of the method was confirmed by the analysis of certified reference copper (CRM#075). The interferences were removed effectively, so that a calibration curve method based on simple aqueous standards could be used. The analyzed values were in the range of 96.6% (Mn) to 113% (Co) of the certified values. The relative standard deviations for the simultaneous determination of Mn (6.5 μg/l), Fe(18 μg/l) and Co(5 μg/l) in solution from copper are 2.4–3.5% and the detection limits were 0.17 μg/g for Mn, 0.50 μg/g for Fe and 0.30 μg/g for Co.
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Direct determination of cadmium and copper in seawater using a transversely heated graphite furnace Atomic Absorption Spectrometer with Zeeman-effect background corrector.
Talanta, 2000Co-Authors: Mei-shu Chan, Shang-da HuangAbstract:Abstract Methods for the direct determination of copper and cadmium in seawater were described using a graphite furnace Atomic Absorption Spectrometer (GFAAS) equipped with a transversely heated graphite atomizer (THGA) and a longitudinal Zeeman effect background corrector. Ammonium nitrate was used as the chemical modifier to determine copper. The mixture of di-ammonium hydrogen phosphate and ammonium nitrate was used as the chemical modifier to determine cadmium. The matrix interference was removed completely so that a simple calibration curve method could be applied. This work is the first one with the capability of determining cadmium in unpolluted seawater directly with GFAAS using calibration curve based on simple aqueous standards. The accuracy of the methods was confirmed by analysis of three kinds of certified reference saline waters. The detection limits (LODs), with injection of a 20-μl aliquot of seawater sample, were 0.06 μg l −1 for copper and 0.005 μg l −1 for cadmium.
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Direct and simultaneous determination of molybdenum and vanadium in sea-water using a multielement electrothermal Atomic Absorption Spectrometer
Journal of Analytical Atomic Spectrometry, 1998Co-Authors: Shang-da HuangAbstract:Direct and simultaneous determinations of Mo and V in sea-water using a multi-element electrothermal Atomic Absorption Spectrometer (Perkin-Elmer SIMAA 6000) are described. Three kinds of chemical modifier [Mg(NO3)2 , Pd(NO3)2 and a mixture of both] were tested. A simple calibration curve method could be used to determine Mo in sea-water using Pd or a mixture of Pd and Mg as the chemical modifier. A standard additions method was used to determine V and to determine Mo and V simultaneously in sea-water. The detection limits were 0.35–0.60 µg l–1 for Mo. The detection limit for V in this work (0.32–0.51 µg l–1) is much lower than those reported in the literature (18–50 µg l–1), such that direct determination of V in unpolluted sea-water (
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Direct and simultaneous determination of copper and manganese in seawater with a multielement graphite furnace Atomic Absorption Spectrometer
Spectrochimica Acta Part B: Atomic Spectroscopy, 1998Co-Authors: Shang-da HuangAbstract:Abstract The direct and simultaneous determinations of Cu and Mn in seawater using a multielement graphite furnace Atomic Absorption Spectrometer (Perkin-Elmer SIMAA6000) are described. Three kinds of chemical modifier (Mg(NO 3 ) 2 , Pd(NO 3 ) 2 and a mixture of these) were tested. The matrix interferences were removed completely so that a simple calibration curve method could be used to determine Cu and Mn in seawater from the open ocean using Pd or a mixture of Pd and Mg as the chemical modifier. The relative standard deviations (RSDs) for the simultaneous determination of Cu and Mn in seawater from open ocean are 10% or less, and the detection limits were 0.07 μg 1 −1 for Cu and 0.10 μg 1 −1 for Mn, using Pd as the chemical modifier. The accuracy of the method is confirmed by analysis of four kinds of certified reference saline waters.
Bradley T. Jones - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of a continuum source tungsten coil Atomic Absorption Spectrometer: a study of Zn behavior
Journal of the Brazilian Chemical Society, 2005Co-Authors: Joaquim A. Nóbrega, Jennifer A. Rust, Clifton P. Calloway, Bradley T. JonesAbstract:The performance of a tungsten coil atomizer Atomic Absorption Spectrometer with a D2 lamp continuum source, a Czerny-Turner monochromator, and a charge coupled device detector was evaluated for the determination of Zn. The main attractive characteristics of the instrument are its simplicity and the relative low cost of the atomizer. In spite of a poor limit of detection (40 µg L-1, 3 blank standard deviation/slope), Zn was accurately determined in one water and one urine certified reference standards. The recovery in water was 106% and in urine the obtained result is in the acceptable certified range.
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Analytical characteristics of a continuum-source tungsten coil Atomic Absorption Spectrometer.
Analytical Sciences, 2005Co-Authors: Jennifer A. Rust, Joaquim A. Nóbrega, Clifton P. Calloway, Bradley T. JonesAbstract:A continuum-source tungsten coil electrothermal Atomic Absorption Spectrometer has been assembled, evaluated, and employed in four different applications. The instrument consists of a xenon arc lamp light source, a tungsten coil atomizer, a Czerny-Turner high resolution monochromator, and a linear photodiode array detector. This instrument provides simultaneous multi-element analyses across a 4 nm spectral window with a resolution of 0.024 nm. Such a device might be useful in many different types of analyses. To demonstrate this broad appeal, four very different applications have been evaluated. First of all, the temperature of the gas phase was measured during the atomization cycle of the tungsten coil, using tin as a thermometric element. Secondly, a summation approach for two Absorption lines for aluminum falling within the same spectral window (305.5 - 309.5 nm) was evaluated. This approach improves the sensitivity without requiring any additional preconcentration steps. The third application describes a background subtraction technique, as it is applied to the analysis of an oil emulsion sample. Finally, interference effects caused by Na on the atomization of Pb were studied. The simultaneous measurements of Pb and Na suggests that negative interference arises at least partially from competition between Pb and Na atoms for H2 in the gas phase.
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A Rowland Circle, multielement graphite furnace Atomic Absorption Spectrometer
Spectrochimica Acta Part B: Atomic Spectroscopy, 1998Co-Authors: Karla. Wagner, James D. Batchelor, Bradley T. JonesAbstract:Abstract A simultaneous, multielement Atomic Absorption Spectrometer utilizing a graphite furnace atomizer was constructed and evaluated. The optical arrangement employs a concave grating to combine the spectral output from a deuterium lamp and four hollow cathode lamps that are placed on the perimeter of a Rowland Circle. A graphite furnace atomizer is positioned on the circle at the point of convergence of the five light sources. Background correction is performed by the continuum source method. Simultaneous detection of the analyte Absorption signals is accomplished with a charged-coupled device. Four test elements were used for evaluation purposes: cadmium, lead, copper and chromium. Even though the elements differ greatly in volatility, the detection limits approach the values published for single element GFAAS: 4, 12, 14 and 12 pg for Cd, Pb, Cu and Cr, respectively. The characteristic masses (integrated absorbance) for the four metals are 3, 24, 14 and 7 pg, respectively. Three drinking water reference materials are analyzed: NIST SRM #1643b (Trace Elements in Water), Fisher Scientific “Metals Drinking Water Standard,” and High Purity Standards “Drinking Water Metals Solution A and B”. The determined amounts were within 10% of the certified values for each of the four elements for all three reference materials.
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Determination of Cadmium with a Portable, Battery-Powered Tungsten Coil Atomic Absorption Spectrometer
Applied Spectroscopy, 1998Co-Authors: James D. Batchelor, Susan E. Thomas, Bradley T. JonesAbstract:A portable Atomic Absorption Spectrometer is described that is powered by a 12 V car battery. The atomization device is a tungsten coil extracted from a common projector lamp bulb. The coil is housed in a glass cell, and the atomization environment is purged with 10% H2 in Ar (available as a standard commercial welding gas) to prevent oxidation. The detection system is a miniature charge-coupled device (CCD) Spectrometer mounted on a PC board. The device is controlled by a laptop computer. Background correction measurements are performed by the near-line method. Aqueous standard solutions provide a Cd detection limit of 3 mu g/L (60 pg) for a 20 mu L sample volume. Accuracies for the determination of Cd in urine, soil, and stream water are typically better than 90%, with relative standard deviations in the 10% range.
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A simple, low cost, multielement Atomic Absorption Spectrometer with a tungsten coil atomizer
Spectrochimica Acta Part B: Atomic Spectroscopy, 1998Co-Authors: Karla. Wagner, Keith E. Levine, Bradley T. JonesAbstract:An inexpensive, multielement Atomic Absorption Spectrometer utilizing a tungsten coil atomizer has been developed. The novel optical arrangement employs three 60° beam combiners to blend the spectral output from four light sources such as electrodeless discharge lamps, or hollow cathode lamps, and then direct that output over an atomizer. This instrument uses an inexpensive tungsten coil atomizer that is extracted from a standard 150 W projector bulb. The temperature of the coil is computer-controlled by changing the voltage across the coil. A low voltage is first used to dry the sample then a higher voltage is used to atomize the sample. Simultaneous detection of the analyte Absorption signals is accomplished using a charge-coupled device. The elements of interest in this study were Cd, Pb, and Cu. Near-line background correction was used to correct for nonspecific analyte Absorption.
Yu. V. Rogul’skii - One of the best experts on this subject based on the ideXlab platform.
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Tungsten-assisted modification of graphite furnaces for an Atomic Absorption Spectrometer
Journal of Applied Spectroscopy, 2009Co-Authors: A. N. Kulik, A. N. Bugai, Yu. V. Rogul’skii, T. G. KalinichenkoAbstract:We have used scanning electron microscopy to study changes in the morphology of the inner surface of graphite tube furnaces for an Atomic Absorption Spectrometer when modified by tungsten. We have demonstrated the role of the tungsten-containing material as a dividing interlayer between the sample to be dispensed and the carbon component of the furnace. We consider the advantages and disadvantages of furnaces modified by the proposed methods.
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Effect on silicon atomization of tungsten-assisted modification of Atomic-Absorption Spectrometer graphite furnaces
Journal of Applied Spectroscopy, 2008Co-Authors: A. N. Kulik, A. N. Buhay, Yu. V. Rogul’skiiAbstract:The influence of a tungsten-assisted modification to a tubular graphite furnace in an Atomic Absorption Spectrometer on the Si atomization signal characteristics is studied. A hypothesis is proposed that explains a shift of Si atomization peaks for the modified furnaces compared with the standard ones. Some advantages of the standard tubular graphite furnaces modified by tungsten and the prospects for their application are demonstrated.
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EFFECT OF WEAR OF THE Atomic-Absorption Spectrometer GRAPHITE FURNACE ON THE ANALYTICAL ZONE TEMPERATURE
Journal of Engineering Physics and Thermophysics, 2007Co-Authors: A. N. Kulik, A. N. Bugai, Yu. V. Rogul’skii, M. I. Zakharets, Leonid F. SukhodubAbstract:One mechanism of increase in the heating temperature of the analytical zone of the graphite tube furnace of the Atomic-Absorption Spectrometer as a result of wear is discussed. The influence of the furnace profile on its heating temperature is shown, and the calculated heating temperature of the standard tube is compared to the temperature in the special case where the cross-section area of the analytical zone of the furnace is reduced by half. Experimental proofs of a given temperature excess, as well as of a relation between the change in the tube profile and the decrease in its mass, are given. The dependence of temperature on the furnace mass and the number of measurements has been investigated. The necessity of taking into account the increase in the heating temperature of the furnace in the wear process has been considered.
A. N. Kulik - One of the best experts on this subject based on the ideXlab platform.
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Tungsten-assisted modification of graphite furnaces for an Atomic Absorption Spectrometer
Journal of Applied Spectroscopy, 2009Co-Authors: A. N. Kulik, A. N. Bugai, Yu. V. Rogul’skii, T. G. KalinichenkoAbstract:We have used scanning electron microscopy to study changes in the morphology of the inner surface of graphite tube furnaces for an Atomic Absorption Spectrometer when modified by tungsten. We have demonstrated the role of the tungsten-containing material as a dividing interlayer between the sample to be dispensed and the carbon component of the furnace. We consider the advantages and disadvantages of furnaces modified by the proposed methods.
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Effect on silicon atomization of tungsten-assisted modification of Atomic-Absorption Spectrometer graphite furnaces
Journal of Applied Spectroscopy, 2008Co-Authors: A. N. Kulik, A. N. Buhay, Yu. V. Rogul’skiiAbstract:The influence of a tungsten-assisted modification to a tubular graphite furnace in an Atomic Absorption Spectrometer on the Si atomization signal characteristics is studied. A hypothesis is proposed that explains a shift of Si atomization peaks for the modified furnaces compared with the standard ones. Some advantages of the standard tubular graphite furnaces modified by tungsten and the prospects for their application are demonstrated.
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EFFECT OF WEAR OF THE Atomic-Absorption Spectrometer GRAPHITE FURNACE ON THE ANALYTICAL ZONE TEMPERATURE
Journal of Engineering Physics and Thermophysics, 2007Co-Authors: A. N. Kulik, A. N. Bugai, Yu. V. Rogul’skii, M. I. Zakharets, Leonid F. SukhodubAbstract:One mechanism of increase in the heating temperature of the analytical zone of the graphite tube furnace of the Atomic-Absorption Spectrometer as a result of wear is discussed. The influence of the furnace profile on its heating temperature is shown, and the calculated heating temperature of the standard tube is compared to the temperature in the special case where the cross-section area of the analytical zone of the furnace is reduced by half. Experimental proofs of a given temperature excess, as well as of a relation between the change in the tube profile and the decrease in its mass, are given. The dependence of temperature on the furnace mass and the number of measurements has been investigated. The necessity of taking into account the increase in the heating temperature of the furnace in the wear process has been considered.
Xiaodong Wen - One of the best experts on this subject based on the ideXlab platform.
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Application of portable tungsten coil electrothermal Atomic Absorption Spectrometer for the determination of trace cobalt after ultrasound-assisted rapidly synergistic cloud point extraction
Microchemical Journal, 2017Co-Authors: Luqiong Chen, Shengchun Yang, Zirong Lei, Xiaodong WenAbstract:Abstract In this work, ultrasound-assisted rapidly synergistic cloud point extraction (UARS-CPE) was firstly established and combined with a portable tungsten coil electrothermal Atomic Absorption Spectrometer (W-coil ET-AAS) for preconcentration and determination of trace cobalt. As a new instrument, the application of the portable W-coil Spectrometer was expanded through the coupling with UARS-CPE, which was accomplished at room temperature rapidly by the effect of ultrasound and revulsant/synergic reagent. The instrumental conditions and influencing factors relevant to UARS-CPE efficiency, such as concentrations of surfactant and chelating agent, volume of revulsant/synergic reagent, pH, and ultrasound extraction time were studied systematically. The coupling improved the analytical performance of the portable Spectrometer considerably. Under the optimal conditions, the limit of detection (LOD) for cobalt was 0.30 μg/L, with sensitivity enhancement factor (EF) of 52. In order to validate its application in field analysis, some environmental water samples were field-analyzed with satisfactory results. The established method could be expanded to pre-concentrate and detect many other trace metal ions.
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Combination of knotted reactor with portable tungsten coil electrothermal Atomic Absorption Spectrometer for on-line determination of trace cadmium
Microchemical Journal, 2016Co-Authors: Xiaodong Wen, Shengchun Yang, Haizhu Zhang, Qingwen DengAbstract:Abstract In this work, flow injection (FI) on-line precipitation–dissolution in a knotted reactor (KR) was established and combined with a portable tungsten coil electrothermal Atomic Absorption Spectrometer (W-coil ET-AAS) firstly for preconcentration and determination of ultra-trace cadmium. As a new instrument, the application of the portable W-coil Spectrometer was expanded to carry out on-line preconcentration and detection through the coupling with a KR system. A self-assembled FI system was employed to hyphenate the KR system with W-coil ET-AAS. The instrumental conditions and influencing factors relevant to KR efficiency, such as concentration of ammonia, pH, conditions of sampling and elution were studied systematically. The coupling improved the analytical performance of the portable Spectrometer considerably. Under the optimal conditions, the limit of detection (LOD) for cadmium was 0.006 μg/L, with sensitivity enhancement factor (EF) of 41. The established method could be expanded and used for on-line preconcentration and detection of some other trace metal ions.
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Determination of Cr(VI) by portable tungsten coil electrothermal Atomic Absorption Spectrometer after surfactant-assisted dispersive liquid-liquid microextraction
International Journal of Environmental Analytical Chemistry, 2014Co-Authors: Xiaodong Wen, Shengchun Yang, Haizhu Zhang, Xia Zhao, Jie GuoAbstract:As a new developed instrument, a portable tungsten coil electrothermal Atomic Absorption Spectrometer (W-coil ET-AAS) was first coupled with surfactant assisted dispersive liquid–liquid microextraction (SA-DLLME) to improve its analytical performance and expand its applications in this work. SA-DLLME was very simple, rapid and the extraction efficiency was considerably improved by the effect of surfactant, which was suitable to be coupled with the portable instrument in field analysis. After SA-DLLME, concentrated chromium in organic phase was directly determined on W-coil atomiser. The influence factors relevant to SA-DLLME and instrumental conditions were studied systematically. Under the optimal conditions, the limit of detection (LOD) for Cr(VI) was 0.016 µg L−1, with sensitivity enhancement factor (EF) of 107. The relative standard deviation (RSD) for seven replicate measurements of 0.5 µg L−1 of Cr(VI) was 4.6%. The recoveries for the spiked samples were in the acceptable range of 96.8–104%. The rap...
