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Sample records for atomic absorption spectrom

  1. Graphite filter atomizer in atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Katskov, Dmitri A.

    2007-09-01

    Graphite filter atomizers (GFA) for electrothermal atomic absorption spectrometry (ETAAS) show substantial advantages over commonly employed electrothermal vaporizers and atomizers, tube and platform furnaces, for direct determination of high and medium volatility elements in matrices associated with strong spectral and chemical interferences. Two factors provide lower limits of detection and shorter determination cycles with the GFA: the vaporization area in the GFA is separated from the absorption volume by a porous graphite partition; the sample is distributed over a large surface of a collector in the vaporization area. These factors convert the GFA into an efficient chemical reactor. The research concerning the GFA concept, technique and analytical methodology, carried out mainly in the author's laboratory in Russia and South Africa, is reviewed. Examples of analytical applications of the GFA in AAS for analysis of organic liquids and slurries, bio-samples and food products are given. Future prospects for the GFA are discussed in connection with analyses by fast multi-element AAS.

  2. [Study on lead absorption in pumpkin by atomic absorption spectrophotometry].

    PubMed

    Li, Zhen-Xia; Sun, Yong-Dong; Chen, Bi-Hua; Li, Xin-Zheng

    2008-07-01

    A study was carried out on the characteristic of lead absorption in pumpkin via atomic absorption spectrophotometer. The results showed that lead absorption amount in pumpkin increased with time, but the absorption rate decreased with time; And the lead absorption amount reached the peak in pH 7. Lead and cadmium have similar characteristic of absorption in pumpkin.

  3. [Study on cadmium absorption in pumpkin by atomic absorption spectrophotometry].

    PubMed

    Li, Zhen-Xia; Jing, Rui-Jun; Dong, Wei-Hua; Li, Xin-Zheng; Liu, Hong

    2006-08-01

    A study was carried out on the characteristic of cadmium absorption in pumpkin by atomic absorption spectrophotometer. The results show that the cadmium absorption amount in pumpkin increased with the increase in cadmium concentration. Meanwhile the cadmium absorption amount in pumpkin increased with time. Eight hours after being cultured in the liquid, the cadmium absorption amount became saturated. The cadmium absorption rate reached the peak after 2 hours, then the absorption rate gradually reduced. The cadmium absorption amount in pumpkin is less in acid or alkali compared with neutral condition. And the absorption amount became minimum in pH 3, while maximum in pH 7.

  4. Atomic absorption spectroscopy in ion channel screening.

    PubMed

    Stankovich, Larisa; Wicks, David; Despotovski, Sasko; Liang, Dong

    2004-10-01

    This article examines the utility of atomic absorption spectroscopy, in conjunction with cold flux assays, to ion channel screening. The multiplicity of ion channels that can be interrogated using cold flux assays and atomic absorption spectroscopy is summarized. The importance of atomic absorption spectroscopy as a screening tool is further elaborated upon by providing examples of the relevance of ion channels to various physiological processes and targeted diseases.

  5. Optimized absorption imaging of mesoscopic atomic clouds

    NASA Astrophysics Data System (ADS)

    Muessel, Wolfgang; Strobel, Helmut; Joos, Maxime; Nicklas, Eike; Stroescu, Ion; Tomkovič, Jiří; Hume, David B.; Oberthaler, Markus K.

    2013-10-01

    We report on the optimization of high-intensity absorption imaging for small Bose-Einstein condensates. The imaging calibration exploits the linear scaling of the quantum projection noise with the mean number of atoms for a coherent spin state. After optimization for atomic clouds containing up to 300 atoms, we find an atom number resolution of atoms, mainly limited by photon shot noise and radiation pressure.

  6. Absorption imaging of a single atom

    NASA Astrophysics Data System (ADS)

    Streed, Erik W.; Jechow, Andreas; Norton, Benjamin G.; Kielpinski, David

    2012-07-01

    Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in a vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorption imaged at near wavelength resolution with a phase Fresnel lens. The observed image contrast of 3.1 (3)% is the maximum theoretically allowed for the imaging resolution of our set-up. The absorption of photons by single atoms is of immediate interest for quantum information processing. Our results also point out new opportunities in imaging of light-sensitive samples both in the optical and X-ray regimes.

  7. Absorption imaging of a single atom.

    PubMed

    Streed, Erik W; Jechow, Andreas; Norton, Benjamin G; Kielpinski, David

    2012-07-03

    Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in a vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorption imaged at near wavelength resolution with a phase Fresnel lens. The observed image contrast of 3.1 (3)% is the maximum theoretically allowed for the imaging resolution of our set-up. The absorption of photons by single atoms is of immediate interest for quantum information processing. Our results also point out new opportunities in imaging of light-sensitive samples both in the optical and X-ray regimes.

  8. Microdroplet Sample Application in Electrothermal Atomization for Atomic Absorption Spectrometry.

    DTIC Science & Technology

    1982-03-29

    ad ideftify by Week amber) atomic absorption spectroscopy microsampl ing graphite- furnace AAS automation C> 20. AOSTRACT (Coninuhe an reveresi de It...furnace and spectrometer system as well as for partial support of this project. REFERENCES 1. J. D. Winefordner, Atomic Absorption Spectroscopy , G. F

  9. Atomic Absorption, Atomic Fluorescence, and Flame Emission Spectrometry.

    ERIC Educational Resources Information Center

    Horlick, Gary

    1984-01-01

    This review is presented in six sections. Sections focus on literature related to: (1) developments in instrumentation, measurement techniques, and procedures; (2) performance studies of flames and electrothermal atomizers; (3) applications of atomic absorption spectrometry; (4) analytical comparisons; (5) atomic fluorescence spectrometry; and (6)…

  10. Atomic Absorption, Atomic Fluorescence, and Flame Emission Spectrometry.

    ERIC Educational Resources Information Center

    Horlick, Gary

    1984-01-01

    This review is presented in six sections. Sections focus on literature related to: (1) developments in instrumentation, measurement techniques, and procedures; (2) performance studies of flames and electrothermal atomizers; (3) applications of atomic absorption spectrometry; (4) analytical comparisons; (5) atomic fluorescence spectrometry; and (6)…

  11. Do Atoms Really "Emit" Absorption Lines?

    ERIC Educational Resources Information Center

    Brecher, Kenneth

    1991-01-01

    Presents three absorption line sources that enhance student understanding of the phenomena associated with the interaction of light with matter and help dispel the misconception that atoms "emit" absorption lines. Sources include neodymium, food coloring and other common household liquids, and fluorescent materials. (MDH)

  12. Do Atoms Really "Emit" Absorption Lines?

    ERIC Educational Resources Information Center

    Brecher, Kenneth

    1991-01-01

    Presents three absorption line sources that enhance student understanding of the phenomena associated with the interaction of light with matter and help dispel the misconception that atoms "emit" absorption lines. Sources include neodymium, food coloring and other common household liquids, and fluorescent materials. (MDH)

  13. The oscillator strength in atomic absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Hannaford, P.

    1994-12-01

    The role of the oscillator strength, f, in the theory of atomic absorption is investigated. For a pure natural broadened absorption line, the peak absorption coefficient α o is independent of the oscillator strength. The peak absorption coefficient becomes dependent on f only through additional broadening processes such as Doppler or collisional broadening. The peak cross section for resonance absorption, α 0/ N1, for a closed transition with equal statistical weights is given by σ 0 = 2πXXX 2 = ( 2/π)/[c n(ω 0)] (where XXX = λ/2π and n(ω 0) is the spectral mode density of the radiation field at the resonance frequency ω 0) and physically represents the cross-sectional area per allowed mode of the radiation field per unit time per unit frequency interval, multiplied by a lineshape factor 2/π. A summary is presented of some recent determinations of oscillator strengths of atomic absorption lines, based on lifetime measurements made in this laboratory. The results are used to revise values of the theoretical characteristic mass for Ag, Al, Au, Ca, Cu, Mo, Na, Ti and V used in absolute analysis by graphite furnace atomic absorption spectroscopy.

  14. Continuum Absorption Coefficient of Atoms and Ions

    NASA Technical Reports Server (NTRS)

    Armaly, B. F.

    1979-01-01

    The rate of heat transfer to the heat shield of a Jupiter probe has been estimated to be one order of magnitude higher than any previously experienced in an outer space exploration program. More than one-third of this heat load is due to an emission of continuum radiation from atoms and ions. The existing computer code for calculating the continuum contribution to the total load utilizes a modified version of Biberman's approximate method. The continuum radiation absorption cross sections of a C - H - O - N ablation system were examined in detail. The present computer code was evaluated and updated by being compared with available exact and approximate calculations and correlations of experimental data. A detailed calculation procedure, which can be applied to other atomic species, is presented. The approximate correlations can be made to agree with the available exact and experimental data.

  15. Flameless Atomic Absorption Spectrophotometric Analysis for Lewisite (L).

    DTIC Science & Technology

    1978-10-01

    method that was developed for detection of Lewisite by analysis for arsenic, using flameless atomic absorption spectroscopy (FAAS). “Flameless atomic ...place in a furnace, and the flame associated with con- ventional atomic absorption spectroscopy is not needed. The procedure that was used is given along...nickel was unnecessary for the Lewisite samples. Table 1. Flameless atomic absorption spectroscopy conditions used for determination of arsenic in

  16. Zeeman effect in flame atomic absorption spectrometry

    SciTech Connect

    Brodie, K.G.; Liddell, P.R.

    1980-06-01

    An electromagnet is used to apply a modulated transverse magnetic field to a 6-cm length burner. A fixed linear polarizer is used to eliminate the ..pi.. component. Sixty-six elements are examined in the appropriate acetylene fuelled flame, using either nitrous oxide or air as the supporting gas. Zeeman sensitivity ratios range from 36% to 94%. The accuracy of background correction for non-atomic absorption in the flame is superior to conventional background correction systems. Detection limits for some elements are better due to the reduction in flame noise. However, the reflex nature of the analytical curve reduces the linear dynamic range and introduces the possibility of ambiguous results. 8 figures, 2 tables.

  17. 2. VIEW IN ROOM 111, ATOMIC ABSORPTION BERYLLIUM ANALYSIS LABORATORY. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW IN ROOM 111, ATOMIC ABSORPTION BERYLLIUM ANALYSIS LABORATORY. AIR FILTERS AND SWIPES ARE DISSOLVED WITH ACIDS AND THE REMAINING RESIDUES ARE SUSPENDED IN NITRIC ACID SOLUTION. THE SOLUTION IS PROCESSED THROUGH THE ATOMIC ABSORPTION SPECTROPHOTOMETER TO DETECT THE PRESENCE AND LEVELS OF BERYLLIUM. - Rocky Flats Plant, Health Physics Laboratory, On Central Avenue between Third & Fourth Streets, Golden, Jefferson County, CO

  18. [Digestion-flame atomic absorption spectroscopy].

    PubMed

    Xu, Liang; Hu, Jian-Guo; Liu, Rui-Ping; Wang, Zhi-Min; Narenhua

    2008-01-01

    A microwave digestion-flame atomic absorption spectroscopy (FAAS) method was developed for the determination of metal elements Na, Zn, Cu, Fe, Mn, Ca and Mg in Mongolian patents. The instrument parameters for the determination were optimized, and the appropriate digestion solvent was selected. The recovery of the method was between 95.8% and 104.3%, and the RSD was between 1.6% and 4.2%. The accuracy and precision of the method was tested by comparing the values obtained from the determination of the standard sample, bush twigs and leaves (GSV-1) by this method with the reference values of GSV-1. The determination results were found to be basically consistent with the reference values. The microwave digestion technique was applied to process the samples, and the experimental results showed that compared to the traditional wet method, the present method has the merits of simplicity, saving agents, rapidness, and non-polluting. The method was accurate and reliable, and could be used to determine the contents of seven kinds of metal elements in mongolian patents.

  19. Flameless atomic-absorption determination of gold in geological materials

    USGS Publications Warehouse

    Meier, A.L.

    1980-01-01

    Gold in geologic material is dissolved using a solution of hydrobromic acid and bromine, extracted with methyl isobutyl ketone, and determined using an atomic-absorption spectrophotometer equipped with a graphite furnace atomizer. A comparison of results obtained by this flameless atomic-absorption method on U.S. Geological Survey reference rocks and geochemical samples with reported values and with results obtained by flame atomic-absorption shows that reasonable accuracy is achieved with improved precision. The sensitivity, accuracy, and precision of the method allows acquisition of data on the distribution of gold at or below its crustal abundance. ?? 1980.

  20. Determination of iridium in mafic rocks by atomic absorption

    USGS Publications Warehouse

    Grimaldi, F.S.; Schnepfe, M.M.

    1970-01-01

    Iridium is determined in mineralized mafic rocks by atomic absorption after fire-assay concentration into a gold bead. Interelement interferences in the atomic-absorption determination are removed and Ir sensitivity is increased by buffering the solutions with a mixture of copper and sodium sulphates. Substantial amounts of Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Fe, Ho, Hg, K, La, Mg, Mn, Mo, Ni, Pb, Te, Ti, V, Y, Zn and platinum metals can be tolerated in the atomic-absorption determination. The sensitivity and detection limits are 3.2 and 0.25 ppm of Ir, respectively. ?? 1970.

  1. Recent developments in atomizers for electrothermal atomic absorption spectrometry.

    PubMed

    Frech, W

    1996-06-01

    This review first describes general requirements to be met for suitable base materials used to produce electrothermal atomizers (ETAs). In this connection the physical and chemical properties of adequate types of graphite and metals are discussed. Further, various atomizer designs, their temperature dynamics during atomization and general performance characteristics are critically reviewed. For end-heated Massmann-type atomizers, discussions are focused on recent developments of, e.g., contoured tubes to achieve improved temperature homogeneity over the tube length, second surface atomizers to realize temporally isothermal atomization and tubes with graphite filters to reduce interference effects. The state-of-the-art of platform equipped, side-heated atomizers with integrated contacting bridges are characterized mainly with respect to heating dynamics, as well as susceptibility to interference- and memory effects. In contrast to end-heated ETAs, the tube ends of side-heated ETAs are freely located in the furnace compartment and, as a consequence of this configuration, convective gas flows can easily appear. The magnitude and effect of these flows on analytical performance are discussed and measures are suggested, permitting operation under diffusion controlled conditions. A critical comparison of classical constant temperature atomizers with state-of-the-art platform equipped ETAs is made and from this it is concluded that future ETA developments are likely to involve only minor modifications aiming at, e.g., the reduction of cycling times or the improvement of tube surface properties.

  2. Visualizing the Solute Vaporization Interference in Flame Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Dockery, Christopher R.; Blew, Michael J.; Goode, Scott R.

    2008-01-01

    Every day, tens of thousands of chemists use analytical atomic spectroscopy in their work, often without knowledge of possible interferences. We present a unique approach to study these interferences by using modern response surface methods to visualize an interference in which aluminum depresses the calcium atomic absorption signal. Calcium…

  3. Visualizing the Solute Vaporization Interference in Flame Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Dockery, Christopher R.; Blew, Michael J.; Goode, Scott R.

    2008-01-01

    Every day, tens of thousands of chemists use analytical atomic spectroscopy in their work, often without knowledge of possible interferences. We present a unique approach to study these interferences by using modern response surface methods to visualize an interference in which aluminum depresses the calcium atomic absorption signal. Calcium…

  4. Perfect electromagnetic absorption at one-atom-thick scale

    SciTech Connect

    Li, Sucheng; Duan, Qian; Li, Shuo; Yin, Qiang; Lu, Weixin; Li, Liang; Hou, Bo; Gu, Bangming; Wen, Weijia

    2015-11-02

    We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration.

  5. Principles and calibration of collinear photofragmentation and atomic absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Sorvajärvi, Tapio; Toivonen, Juha

    2014-06-01

    The kinetics of signal formation in collinear photofragmentation and atomic absorption spectroscopy (CPFAAS) are discussed, and theoretical equations describing the relation between the concentration of the target molecule and the detected atomic absorption in case of pure and impure samples are derived. The validity of the equation for pure samples is studied experimentally by comparing measured target molecule concentrations to concentrations determined using two other independent techniques. Our study shows that CPFAAS is capable of measuring target molecule concentrations from parts per billion (ppb) to hundreds of parts per million (ppm) in microsecond timescale. Moreover, the possibility to extend the dynamic range to cover eight orders of magnitude with a proper selection of fragmentation light source is discussed. The maximum deviation between the CPFAAS technique and a reference measurement technique is found to be less than 5 %. In this study, potassium chloride vapor and atomic potassium are used as a target molecule and a probed atom, respectively.

  6. Determination of palladium and platinum by atomic absorption

    USGS Publications Warehouse

    Schnepfe, M.M.; Grimaldi, F.S.

    1969-01-01

    Palladium and platinum are determined by atomic absorption after fire-assay concentration into a gold bead. The limit of determination is ~0??06 ppm in a 20-g sample. Serious depressive interelement interferences are removed by buffering the solutions with a mixture of cadmium and copper sulphates with cadmium and copper concentrations each at 0??5%. Substantial amounts of Ag, Al, Au, Bi, Ca, Co, Cr, Fe, Hg, K, La, Mg, Mn, Mo, Na, Ni, Pb, Te, Ti, V, Y, Zn, and the platinum metals do not interfere in the atomic-absorption determination. ?? 1969.

  7. Atomic-absorption determination of rhodium in chromite concentrates

    USGS Publications Warehouse

    Schnepfe, M.M.; Grimaldi, F.S.

    1969-01-01

    Rhodium is determined in chromite concentrates by atomic absorption after concentration either by co-precipitation with tellurium formed by the reduction of tellurite with tin(II) chloride or by fire assay into a gold bead. Interelement interferences in the atomic-absorption determination are removed by buffering the solutions with lanthanum sulphate (lanthanum concentration 1%). Substantial amounts of Ag, Al, Au, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ho, Hg, K, La, Mg, Mn, Mo, Na, Ni, Pb, Te, Ti, V, Y, Zn and platinum metals can be tolerated. A lower limit of approximately 0.07 ppm Rh can be determined in a 3-g sample. ?? 1969.

  8. Speciation of mercury compounds by differential atomization - atomic absorption spectroscopy

    SciTech Connect

    Robinson, J.W.; Skelly, E.M.

    1982-01-01

    This paper describes the dual stage atomization technique which allows speciation of several mercury-containing compounds in aqueous solution and in biological fluids. The technique holds great promise for further speciation studies. Accurate temperature control, expecially at temperatures less than 200/sup 0/C, is needed to separate the extremely volatile mercury halides and simple organomercurials from each other. Studies with mercury salts and EDTA, L-cysteine and dithioxamide demonstrate that this technique may be used to study the extent of complex formation. Investigations of biological fluids indicate that there is a single predominant form of mercury in sweat and a single predominant form of mercury in urine. The mercury compound in urine is more volatile than that in sweat. Both quantitative and qualitative analyses are possible with this technique.

  9. [Burner head with high sensitivity in atomic absorption spectroscopy].

    PubMed

    Feng, X; Yang, Y

    1998-12-01

    This paper presents a burner head with gas-sample separate entrance and double access, which is used for atomic absorption spectroscopy. According to comparison and detection, the device can improve sensitivity by a factor of 1 to 5. In the meantime it has properties of high stability and resistance to interference.

  10. Atomic Absorption Spectroscopy. The Present and the Future.

    ERIC Educational Resources Information Center

    Slavin, Walter

    1982-01-01

    The status of current techniques and methods of atomic absorption (AA) spectroscopy (flame, hybrid, and furnace AA) is discussed, including limitations. Technological opportunities and how they may be used in AA are also discussed, focusing on automation, microprocessors, continuum AA, hybrid analyses, and others. (Author/JN)

  11. Developing a Transdisciplinary Teaching Implement for Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Drew, John

    2008-01-01

    In this article I explain why I wrote the set of teaching notes on Atomic Absorption Spectroscopy (AAS) and why they look the way they do. The notes were intended as a student reference to question, highlight and write over as much as they wish during an initial practical demonstration of the threshold concept being introduced, in this case…

  12. Developing a Transdisciplinary Teaching Implement for Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Drew, John

    2008-01-01

    In this article I explain why I wrote the set of teaching notes on Atomic Absorption Spectroscopy (AAS) and why they look the way they do. The notes were intended as a student reference to question, highlight and write over as much as they wish during an initial practical demonstration of the threshold concept being introduced, in this case…

  13. Electrothermal atomic absorption determination of silver in cadmium selenide

    SciTech Connect

    Khozhainov, Y.M.; Deinikina, N.P.; Tyurin, O.A.

    1985-10-01

    The authors developed an atomic absorption method for determining trace silver in cadmium selenide, restricted to samples of 3 - 10 mg. Used as cp reagents, including those further purified, were distilled nitric acid, isothermally distilled hydrochloric acid, cadmium selenide, and S /SUB r/ grade silver with a purity of 99.999%.

  14. Atomic Absorption Spectroscopy. The Present and the Future.

    ERIC Educational Resources Information Center

    Slavin, Walter

    1982-01-01

    The status of current techniques and methods of atomic absorption (AA) spectroscopy (flame, hybrid, and furnace AA) is discussed, including limitations. Technological opportunities and how they may be used in AA are also discussed, focusing on automation, microprocessors, continuum AA, hybrid analyses, and others. (Author/JN)

  15. Precision atomic beam density characterization by diode laser absorption spectroscopy

    SciTech Connect

    Oxley, Paul; Wihbey, Joseph

    2016-09-15

    We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10{sup −5} are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 10{sup 4} atoms cm{sup −3}. The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

  16. Precision atomic beam density characterization by diode laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Oxley, Paul; Wihbey, Joseph

    2016-09-01

    We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10-5 are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 104 atoms cm-3. The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

  17. Precision atomic beam density characterization by diode laser absorption spectroscopy.

    PubMed

    Oxley, Paul; Wihbey, Joseph

    2016-09-01

    We provide experimental and theoretical details of a simple technique to determine absolute line-of-sight integrated atomic beam densities based on resonant laser absorption. In our experiments, a thermal lithium beam is chopped on and off while the frequency of a laser crossing the beam at right angles is scanned slowly across the resonance transition. A lock-in amplifier detects the laser absorption signal at the chop frequency from which the atomic density is determined. The accuracy of our experimental method is confirmed using the related technique of wavelength modulation spectroscopy. For beams which absorb of order 1% of the incident laser light, our measurements allow the beam density to be determined to an accuracy better than 5% and with a precision of 3% on a time scale of order 1 s. Fractional absorptions of order 10(-5) are detectable on a one-minute time scale when we employ a double laser beam technique which limits laser intensity noise. For a lithium beam with a thickness of 9 mm, we have measured atomic densities as low as 5 × 10(4) atoms cm(-3). The simplicity of our technique and the details we provide should allow our method to be easily implemented in most atomic or molecular beam apparatuses.

  18. Studies of atomization from a graphite platform in graphite-furnace atomic-absorption spectrometry.

    PubMed

    Chakrabarti, C L; Chang, S B; Thong, P W; Huston, T J; Wu, S

    1987-02-01

    A theoretical model has been proposed for the transient characteristics of an atomic-absorption pulse generated by atomization from a graphite platform in a pulse-heated graphite-furnace atomic-absorption spectrometer. The model has been used (with the aid of a computer program) to predict the effects of various factors on analyte atom populations as a function of time. The various factors studied were heating rate, initial temperature of the graphite tube wall, platform mass and thickness, and activation energy for the rate-determining step in the reaction sequence leading to atom formation. The results predicted by the model are in reasonable agreement with the experimental results obtained by using lead as the analyte element.

  19. Determination of nanogram amounts of bismuth in rocks by atomic absorption spectrometry with electrothermal atomization

    USGS Publications Warehouse

    Kane, J.S.

    1979-01-01

    Bismuth concentrations as low as 10 ng g-1 in 100-mg samples of geological materials can be determined by atomic absorption spectrometry with electrothermal atomization. After HF-HClO4 decomposition of the sample, bismuth is extracted as the iodide into methyl isobutyl ketone and is then stripped with ethylenediaminetetraacetic acid into the aqueous phase. Aliquots of this solution are pipetted into the graphite furnace and dried, charred, and atomized in an automated sequence. Atomic absorbance at the Bi 223.1-nm line provides a measure of the amount of bismuth present. Results are presented for 14 U.S. Geological Survey standard rocks. ?? 1979.

  20. Quantitative analysis of immobilized metalloenzymes by atomic absorption spectroscopy.

    PubMed

    Opwis, Klaus; Knittel, Dierk; Schollmeyer, Eckhard

    2004-12-01

    A new, sensitive assay for the quantitative determination of immobilized metal containing enzymes has been developed using atomic absorption spectroscopy (AAS). In contrast with conventionally used indirect methods the described quantitative AAS assay for metalloenzymes allows more exact analyses, because the carrier material with the enzyme is investigated directly. As an example, the validity and reliability of the method was examined by fixing the iron-containing enzyme catalase on cotton fabrics using different immobilization techniques. Sample preparation was carried out by dissolving the loaded fabrics in sulfuric acid before oxidising the residues with hydrogen peroxide. The iron concentrations were determined by flame atomic absorption spectrometry after calibration of the spectrometer with solutions of the free enzyme at different concentrations.

  1. [Application of atomic absorption spectrometry in the engine knock detection].

    PubMed

    Chen, Li-Dan

    2013-02-01

    Because existing human experience diagnosis method and apparatus for auxiliary diagnosis method are difficult to diagnose quickly engine knock. Atomic absorption spectrometry was used to detect the automobile engine knock in in innovative way. After having determined Fe, Al, Cu, Cr and Pb content in the 35 groups of Audi A6 engine oil whose travel course is 2 000 -70 000 kilometers and whose sampling interval is 2 000 kilometers by atomic absorption spectrometry, the database of primary metal content in the same automobile engine at different mileage was established. The research shows that the main metal content fluctuates within a certain range. In practical engineering applications, after the determination of engine oil main metal content and comparison with its database value, it can not only help to diagnose the type and location of engine knock without the disintegration and reduce vehicle maintenance costs and improve the accuracy of engine knock fault diagnosis.

  2. WIPP Benchmark calculations with the large strain SPECTROM codes

    SciTech Connect

    Callahan, G.D.; DeVries, K.L.

    1995-08-01

    This report provides calculational results from the updated Lagrangian structural finite-element programs SPECTROM-32 and SPECTROM-333 for the purpose of qualifying these codes to perform analyses of structural situations in the Waste Isolation Pilot Plant (WIPP). Results are presented for the Second WIPP Benchmark (Benchmark II) Problems and for a simplified heated room problem used in a parallel design calculation study. The Benchmark II problems consist of an isothermal room problem and a heated room problem. The stratigraphy involves 27 distinct geologic layers including ten clay seams of which four are modeled as frictionless sliding interfaces. The analyses of the Benchmark II problems consider a 10-year simulation period. The evaluation of nine structural codes used in the Benchmark II problems shows that inclusion of finite-strain effects is not as significant as observed for the simplified heated room problem, and a variety of finite-strain and small-strain formulations produced similar results. The simplified heated room problem provides stratigraphic complexity equivalent to the Benchmark II problems but neglects sliding along the clay seams. The simplified heated problem does, however, provide a calculational check case where the small strain-formulation produced room closures about 20 percent greater than those obtained using finite-strain formulations. A discussion is given of each of the solved problems, and the computational results are compared with available published results. In general, the results of the two SPECTROM large strain codes compare favorably with results from other codes used to solve the problems.

  3. Determination of inorganic plasma sulfate by indirect atomic absorption spectrophotometry.

    PubMed

    Michalk, D; Manz, F

    1980-10-23

    An indirect method for the determination of inorganic sulfate in small plasma volumes is presented. After removal of protein and phosphate by uranylacetate, sulfate is precipitated by barium chloride. Excess barium in the supernatant is measured by atomic absorption spectrophotometry. The sulfate content of the sample corresponds to the difference of the added and the measured barium. The mean concentration of inorganic plasma sulfate of healthy children, determined by this method, was 0.241 +/- 0.059 mmol/l.

  4. Optimization of electrothermal atomization parameters for simultaneous multielement atomic absorption spectrometry

    USGS Publications Warehouse

    Harnly, J.M.; Kane, J.S.

    1984-01-01

    The effect of the acid matrix, the measurement mode (height or area), the atomizer surface (unpyrolyzed and pyrolyzed graphite), the atomization mode (from the wall or from a platform), and the atomization temperature on the simultaneous electrothermal atomization of Co, Cr, Cu, Fe, Mn, Mo, Ni, V, and Zn was examined. The 5% HNO3 matrix gave rise to severe irreproducibility using a pyrolyzed tube unless the tube was properly "prepared". The 5% HCl matrix did not exhibit this problem, and no problems were observed with either matrix using an unpyrolized tube or a pyrolyzed platform. The 5% HCl matrix gave better sensitivities with a pyrolyzed tube but the two matrices were comparable for atomization from a platform. If Mo and V are to be analyzed with the other seven elements, a high atomization temperature (2700??C or greater) is necessary regardless of the matrix, the measurement mode, the atomization mode, or the atomizer surface. Simultaneous detection limits (peak height with pyrolyzed tube atomization) were comparable to those of conventional atomic absorption spectrometry using electrothermal atomization above 280 nm. Accuracies and precisions of ??10-15% were found in the 10 to 120 ng mL-1 range for the analysis of NBS acidified water standards.

  5. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Atomic absorption spectrophotometer for clinical... Laboratory Instruments § 862.2850 Atomic absorption spectrophotometer for clinical use. (a) Identification. An atomic absorption spectrophotometer for clinical use is a device intended to identify and measure...

  6. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Atomic absorption spectrophotometer for clinical... Laboratory Instruments § 862.2850 Atomic absorption spectrophotometer for clinical use. (a) Identification. An atomic absorption spectrophotometer for clinical use is a device intended to identify and measure...

  7. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Atomic absorption spectrophotometer for clinical... Laboratory Instruments § 862.2850 Atomic absorption spectrophotometer for clinical use. (a) Identification. An atomic absorption spectrophotometer for clinical use is a device intended to identify and measure...

  8. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Atomic absorption spectrophotometer for clinical... Laboratory Instruments § 862.2850 Atomic absorption spectrophotometer for clinical use. (a) Identification. An atomic absorption spectrophotometer for clinical use is a device intended to identify and measure...

  9. 21 CFR 862.2850 - Atomic absorption spectrophotometer for clinical use.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Atomic absorption spectrophotometer for clinical... Laboratory Instruments § 862.2850 Atomic absorption spectrophotometer for clinical use. (a) Identification. An atomic absorption spectrophotometer for clinical use is a device intended to identify and measure...

  10. [Measurement of trace elements in blood serum by atomic absorption spectroscopy with electrothermal atomization].

    PubMed

    Rogul'skiĭ, Iu V; Danil'chenko, S N; Lushpa, A P; Sukhodub, L F

    1997-09-01

    Describes a method for measuring trace elements Cr, Mn, Co, Fe, Cu, Zn, and Mo in the blood serum using non-flame atomization (KAC 120.1 complex). Optimal conditions for preparing the samples were defined, temperature regimens for analysis of each element selected, and original software permitting automated assays created. The method permits analysis making use of the minimal samples: 0.1 ml per 10 parallel measurements, which is 100 times less than needed for atomic absorption spectroscopy with flame atomization of liquid samples. Metrological characteristics of the method are assessed.

  11. Cinchocaine hydrochloride determination by atomic absorption spectrometry and spectrophotometry.

    PubMed

    Abdel-Ghani, Nour T; Youssef, Ahmed F A; Awady, Mohamed A

    2005-05-01

    Two sensitive spectrophotometric and atomic absorption spectrometric procedures have been developed for determination of cinchocaine hydrochloride (Cin.Cl) in pure form and in pharmaceutical formulation. The spectrophotometric method was based on formation of an insoluble colored ion-associate between the cited drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC) which dissolved and extracted in an organic solvent. The optimal experimental conditions for quantitative extraction such as pH, concentration of the reagents and solvent were studied. Toluene and iso-butyl alcohol proved to be the most suitable solvents for quantitative extraction of Cin-CoTC and Cin-CrTC ion-associates with maximum absorbance at 620 and 555 nm, respectively. The optimum concentration ranges, molar absorptivities, Ringbom ranges and Sandell sensitivities were also evaluated. The atomic absorption spectrometric method is based on measuring of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm, respectively. Linear application ranges, characteristic masses and detection limits were 57.99-361.9, 50.40 and 4.22 microg ml(-1) of Cin.Cl, in case of CoTC, while 37.99-379.9, 18.94 and 0.81 microg ml(-1) in case of CrTC.

  12. A Comprehensive X-Ray Absorption Model for Atomic Oxygen

    NASA Technical Reports Server (NTRS)

    Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; Garcia, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.; de Vries, C. P.; Zatsarinny, O.

    2013-01-01

    An analytical formula is developed to accurately represent the photoabsorption cross section of atomic Oxygen for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models.

  13. New Optical Absorption Bands in Atomic Layer Superlattices

    NASA Astrophysics Data System (ADS)

    Eckstein, James

    2011-03-01

    Using atomic layer-by-layer molecular beam epitaxy, atomic layer superlattices can be constructed that exhibit new electronic, optical and lattice effects not present in the individual components. In particular, new optical transitions giving rise to sharp absorption peaks can be created by placing a layer of a material with occupied source states next to a layer of another material with unoccupied destination states. We combine atomic layers of SrTi O3 and LaMn O3 into superlattice structures with component layers as thin as single monolayer and find a new absorption band due to a transition from manganese- to titanium-derived states. The energy of the new transition depends on how the bands line up at the interface. Furthermore, a substantial shift of spectral weight occurs as well, while retaining a constant sum rule. This work was supported by the Department of Energy Basic Energy Sciences at the Fredrick Seitz Materials Research Laboratory, University of Illinois, Urbana. This work was done in collaboration with Xiaofang Zhai, Mao Zheng, Amish Shah, Chandra Mohapatra, and Jian-Min Zuo. This work was supported by the Department of Energy Basic Energy Sciences at the Fredrick Seitz Materials Research Laboratory, University of Illinois, Urbana.

  14. The determination of vanadium in brines by atomic absorption spectroscopy

    USGS Publications Warehouse

    Crump-Wiesner, Hans J.; Feltz, H.R.; Purdy, W.C.

    1971-01-01

    A standard addition method is described for the determination of vanadium in brines by atomic absorption spectroscopy with a nitrous oxide-acetylene flame. Sample pH is adjusted to 1.0 with concentrated hydrochloric acid and the vanadium is directly extracted with 5% cupferron in methyl isobutyl ketone (MIBK). The ketone layer is then aspirated into the flame and the recorded absorption values are plotted as a function of the concentration of the added metal. As little as 2.5 ??g l-1 of vanadium can be detected under the conditions of the procedure. Tungsten and tin interfere when present in excess of 5 and 10 ??g ml-1, respectively. The concentrations of the two interfering ions normally found in brines are well below interference levels. ?? 1971.

  15. Analysis of cement by atomic absorption spectrophotometry and volumetric method.

    PubMed

    Choi, K K; Lam, L; Luk, S F

    1994-01-01

    A new method to determine the composition of cement raw mix and cement is devised. The sample was fused with a mixture of sodium carbonate and lithium tetraborate (3:1) at 925 degrees C for 10 min. The fusion cake was dissolved in hydrochloric acid. The concentration of analyte in solution was either determined by atomic absorption spectrophotometry or titrimetry. The proposed method is quick and the analysis for interested oxides (SiO(2), Al(2)O(3), Fe(2)O(3), and CaO) can be completed within 1 hr. The accuracy and precision are comparable to that of X-ray fluorescence spectrometry.

  16. Measuring Microwaves via Absorption and Dispersion in Rydberg Atoms

    NASA Astrophysics Data System (ADS)

    Stack, Daniel; Kunz, Paul; Meyer, David; Solmeyer, Neal

    2016-05-01

    Weak microwave frequency electromagnetic fields can be difficult to detect and fully characterize with traditional methods. However it is possible to transduce the measurement of these fields from the microwave domain to the optical domain via resonant transitions between Rydberg levels in atomic vapors using electromagnetically-induced transparency and the Autler-Townes effect. This technique allows for sensitive measurements of the microwave field amplitude, polarization, and spatial waveform (via the position of the probe and coupling laser beams) as compared to measurements performed with dipole antennas. We are able to obtain these quantities by monitoring the properties of a probe laser beam as it passes through a rubidium vapor cell. Previous experiments using Rydberg spectroscopy have typically relied on measuring the absorption of the probe laser as it passed through the atomic system. We report on progress to use the polarization rotation of the probe as it passes through the atoms in a static magnetic field, which corresponds to the real part of the susceptibility of the atomic medium, for measuring the characteristics of a microwave frequency signal. This effect is known as Nonlinear Magneto Optical Rotation (NMOR) and has been used for sensitive magnetometry.

  17. Atomic Absorption Spectroscopy, Atomic Emission Spectroscopy, and Inductively Coupled Plasma-Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Miller, Dennis D.; Rutzke, Michael A.

    Atomic spectroscopy has played a major role in the development of our current database for mineral nutrients and toxicants in foods. When atomic absorption spectrometers became widely available in the 1960s, the development of atomic absorption spectroscopy (AAS) methods for accurately measuring trace amounts of mineral elements in biological samples paved the way for unprecedented advances in fields as diverse as food analysis, nutrition, biochemistry, and toxicology (1). The application of plasmas as excitation sources for atomic emission spectroscopy (AES) led to the commercial availability of instruments for inductively coupled plasma - atomic emission spectroscopy (ICP-AES) beginning in the late 1970s. This instrument has further enhanced our ability to measure the mineral composition of foods and other materials rapidly, accurately, and precisely. More recently, plasmas have been joined with mass spectrometers (MS) to form inductively coupled plasma-mass spectrometer ICP-MS instruments that are capable of measuring mineral elements with extremely low detection limits. These three instrumental methods have largely replaced traditional wet chemistry methods for mineral analysis of foods, although traditional methods for calcium, chloride, iron, and phosphorus remain in use today (see Chap. 12).

  18. A comprehensive X-ray absorption model for atomic oxygen

    SciTech Connect

    Gorczyca, T. W.; Bautista, M. A.; Mendoza, C.; Hasoglu, M. F.; García, J.; Gatuzz, E.; Kaastra, J. S.; Raassen, A. J. J.; De Vries, C. P.; Kallman, T. R.; Manson, S. T.; Zatsarinny, O.

    2013-12-10

    An analytical formula is developed to accurately represent the photoabsorption cross section of O I for all energies of interest in X-ray spectral modeling. In the vicinity of the K edge, a Rydberg series expression is used to fit R-matrix results, including important orbital relaxation effects, that accurately predict the absorption oscillator strengths below threshold and merge consistently and continuously to the above-threshold cross section. Further, minor adjustments are made to the threshold energies in order to reliably align the atomic Rydberg resonances after consideration of both experimental and observed line positions. At energies far below or above the K-edge region, the formulation is based on both outer- and inner-shell direct photoionization, including significant shake-up and shake-off processes that result in photoionization-excitation and double-photoionization contributions to the total cross section. The ultimate purpose for developing a definitive model for oxygen absorption is to resolve standing discrepancies between the astronomically observed and laboratory-measured line positions, and between the inferred atomic and molecular oxygen abundances in the interstellar medium from XSTAR and SPEX spectral models.

  19. Oscillator strength measurements of atomic absorption lines from stellar spectra

    NASA Astrophysics Data System (ADS)

    Lobel, Alex

    2011-05-01

    Herein we develop a new method to determine oscillator strength values of atomic absorption lines with state-of-the-art detailed spectral synthesis calculations of the optical spectrum of the Sun and of standard spectral reference stars. We update the log(gf) values of 911 neutral lines observed in the KPNO-FTS flux spectrum of the Sun and high-resolution echelle spectra (R = 80 000) of Procyon (F5 IV-V) and Eps Eri (K2 V) observed with large signal-to-noise (S/N) ratios of 2000 using the new Mercator-Hermes spectrograph at La Palma Observatory (Spain). We find for 483 Fe I, 85 Ni I, and 51 Si I absorption lines in the sample a systematic overestimation of the literature log(gf) values with central line depths below 15%. We employ a curve-of-growth analysis technique to test the accuracy of the new oscillator strength values and compare calculated equivalent line widths to the Moore, Minnaert, and Houtgast atlas of the Sun. The online SpectroWeb database at http://spectra.freeshell.org interactively displays the observed and synthetic spectra and provides the new log(gf) values together with important atomic line data. The graphical database is under development for stellar reference spectra of every spectral sub-class observed with large spectral resolution and S/N ratios.

  20. Preconcentration and Atomization of Arsane in a Dielectric Barrier Discharge with Detection by Atomic Absorption Spectrometry.

    PubMed

    Novák, Petr; Dědina, Jiří; Kratzer, Jan

    2016-06-07

    Atomization of arsane in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized, and its performance was compared to that of a multiple microflame quartz tube atomizer (MMQTA) for atomic absorption spectrometry (AAS). Argon, at a flow rate of 60 mL min(-1), was the best DBD discharge gas. Free As atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. A dryer tube filled with NaOH beads placed downstream from the gas-liquid separator to prevent residual aerosol and moisture transport to the atomizer was found to improve the response by 25%. Analytical figures of merit were comparable, reaching an identical sensitivity of 0.48 s ng (-1) As in both atomizers and limits of detection (LOD) of 0.15 ng mL(-1) As in MMQTA and 0.16 ng mL(-1) As in DBD, respectively. Compared to MMQTA, DBD provided 1 order of magnitude better resistance to interference from other hydride-forming elements (Sb, Se, and Bi). Atomization efficiency in DBD was estimated to be 100% of that reached in the MMQTA. A simple procedure of lossless in situ preconcentration of arsane was developed. Addition of 7 mL min(-1) O2 to the Ar plasma discharge resulted in a quantitative retention of arsane in the optical arm of the DBD atomizer. Complete analyte release and atomization was reached as soon as oxygen was switched off. Preconcentration efficiency of 100% was observed, allowing a decrease of the LOD to 0.01 ng mL(-1) As employing a 300 s preconcentration period.

  1. Transient absorption spectra of the laser-dressed hydrogen atom

    NASA Astrophysics Data System (ADS)

    Murakami, Mitsuko; Chu, Shih-I.

    2013-10-01

    We present a theoretical study of transient absorption spectra of laser-dressed hydrogen atoms, based on numerical solutions of the time-dependent Schrödinger equation. The timing of absorption is controlled by the delay between an extreme ultra violet (XUV) pulse and an infrared (IR) laser field. The XUV pulse is isolated and several hundred attoseconds in duration, which acts as a pump to drive the ground-state electron to excited p states. The subsequent interaction with the IR field produces dressed states, which manifest as sidebands between the 1s-np absorption spectra separated by one IR-photon energy. We demonstrate that the population of dressed states is maximized when the timing of the XUV pulse coincides with the zero crossing of the IR field, and that their energies can be manipulated in a subcycle time scale by adding a chirp to the IR field. An alternative perspective to the problem is to think of the XUV pulse as a probe to detect the dynamical ac Stark shifts. Our results indicate that the accidental degeneracy of the hydrogen excited states is removed while they are dressed by the IR field, leading to large ac Stark shifts. Furthermore, we observe the Autler-Townes doublets for the n=2 and 3 levels using the 656 nm dressing field, but their separation does not agree with the prediction by the conventional three-level model that neglects the dynamical ac Stark shifts.

  2. Antimony quantification in Leishmania by electrothermal atomic absorption spectroscopy.

    PubMed

    Roberts, W L; Rainey, P M

    1993-05-15

    Tri- and pentavalent antimony were quantified in Leishmania mexicana pifanoi amastigotes and promastigotes by atomic absorption spectroscopy with electrothermal atomization. Leishmania grown in axenic culture were treated with either potassium antimony tartrate [Sb(III)] or sodium stibogluconate [Sb(V)]. The parasites were collected, digested with nitric acid, and subjected to atomic absorption spectroscopy. The method was linear from 0 to 7 ng of antimony. The interassay coefficients of variation were 9.6 and 5.7% (N = 5) for 0.52 and 3.7-ng samples of leishmanial antimony, respectively. The limit of detection was 95 pg of antimony. The assay was used to characterize Sb(III) and Sb(V) influx and efflux kinetics. Influx rates were determined at antimony concentrations that produced a 50% inhibition of growth (IC50). The influx rates of Sb(V) into amastigotes and promastigotes were 4.8 and 12 pg/million cells/h, respectively, at 200 micrograms antimony/ml. The influx rate of Sb(III) into amastigotes was 41 pg/million cells/h at 20 micrograms antimony/ml. Influx of Sb(III) into promastigotes at 1 microgram antimony/ml was rapid and reached a plateau of 175 pg/million cells in 2 h. Efflux of Sb(III) and Sb(V) from amastigotes and promastigotes exhibited biphasic kinetics. The initial (alpha) half-life of Sb(V) efflux was less than 4 min and that of Sb(III) was 1-2 h. The apparent terminal (beta) half-lives ranged from 7 to 14 h.

  3. The role of atomic absorption spectrometry in geochemical exploration

    USGS Publications Warehouse

    Viets, J.G.; O'Leary, R. M.

    1992-01-01

    In this paper we briefly describe the principles of atomic absorption spectrometry (AAS) and the basic hardware components necessary to make measurements of analyte concentrations. Then we discuss a variety of methods that have been developed for the introduction of analyte atoms into the light path of the spectrophotometer. This section deals with sample digestion, elimination of interferences, and optimum production of ground-state atoms, all critical considerations when choosing an AAS method. Other critical considerations are cost, speed, simplicity, precision, and applicability of the method to the wide range of materials sampled in geochemical exploration. We cannot attempt to review all of the AAS methods developed for geological materials but instead will restrict our discussion to some of those appropriate for geochemical exploration. Our background and familiarity are reflected in the methods we discuss, and we have no doubt overlooked many good methods. Our discussion should therefore be considered a starting point in finding the right method for the problem, rather than the end of the search. Finally, we discuss the future of AAS relative to other instrumental techniques and the promising new directions for AAS in geochemical exploration. ?? 1992.

  4. Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

    ERIC Educational Resources Information Center

    Correia, Paulo R. M.; Oliveira, Pedro V.

    2004-01-01

    The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

  5. Simultaneous Atomic Absorption Spectrometry for Cadmium and Lead Determination in Wastewater: A Laboratory Exercise

    ERIC Educational Resources Information Center

    Correia, Paulo R. M.; Oliveira, Pedro V.

    2004-01-01

    The simultaneous determination of cadmium and lead by multi-element atomic absorption spectrometry with electrochemical atomization is proposed by employing a problem-based approach. The reports indicate that the students assimilated the principles of the simultaneous atomic absorption spectrometry (SIMAAS), the role of the chemical modifier, the…

  6. Determination of Lead in Blood by Atomic Absorption Spectrophotometry1

    PubMed Central

    Selander, Stig; Cramér, Kim

    1968-01-01

    Lead in blood was determined by atomic absorption spectrophotometry, using a wet ashing procedure and a procedure in which the proteins were precipitated with trichloroacetic acid. In both methods the lead was extracted into isobutylmethylketone before measurement, using ammonium pyrrolidine dithiocarbamate as chelator. The simpler precipitation procedure was shown to give results identical with those obtained with the ashing technique. In addition, blood specimens were examined by the precipitation method and by spectral analysis, which method includes wet ashing of the samples, with good agreement. All analyses were done on blood samples from `normal' persons or from lead-exposed workers, and no additions of inorganic lead were made. The relatively simple protein precipitation technique gave accurate results and is suitable for the large-scale control of lead-exposed workers. PMID:5663425

  7. Atomic absorption determination of titanium and vanadium in uranium concentrates

    SciTech Connect

    Batistoni, D.A.; Smichowski, P.N.

    1985-03-01

    An atomic absorption procedure was developed for the determination of titanium and vanadium in medium-purity uranium products (yellow-cakes). Samples equivalent to 4 g uranium were dissolved in 5.5 M nitric acid. Titanium and vanadium were separated from the uranium matrix by column extraction chromatography with the use of tri-n-butyl phosphate (TBP) supported on polytrifluorochloretylene (Kel-F) power. A nitrous oxide-acetylene flame was employed to estimate the concentration of the analytes in the nitric phase. The precision was about 3% relative standard deviation for both elements, with detection limits of 60 ..mu..g/g for Ti and 30 ..mu..g/g for V. The influence of Al, Fe, and PO/sup 3 -//sub 4/ on the measured absorbance values and mutual interferences effects between Ti and V were investigated.

  8. Graphite furnace atomic absorption elemental analysis of ecstasy tablets.

    PubMed

    French, Holly E; Went, Michael J; Gibson, Stuart J

    2013-09-10

    Six metals (copper, magnesium, barium, nickel, chromium and lead) were determined in two separate batches of seized ecstasy tablets by graphite furnace atomic absorption spectroscopy (GFAAS) following digestion with nitric acid and hydrogen peroxide. Large intra-batch variations were found as expected for tablets produced in clandestine laboratories. For example, nickel in batch 1 was present in the range 0.47-13.1 parts per million (ppm) and in batch 2 in the range 0.35-9.06 ppm. Although batch 1 had significantly higher 3,4-methylenedioxy-N-methamphetamine (MDMA) content than batch 2, barium was the only element which discriminated between the two ecstasy seizures (batch 1: 0.19-0.66 ppm, batch 2: 3.77-5.47 ppm).

  9. Determination of Lead in Urine by Atomic Absorption Spectrophotometry1

    PubMed Central

    Selander, Stig; Cramé, Kim

    1968-01-01

    A method for the determination of lead in urine by means of atomic absorption spectrophotometry (AAS) is described. A combination of wet ashing and extraction with ammonium pyrrolidine dithiocarbamate into isobutylmethylketone was used. The sensitivity was about 0·02 μg./ml. for 1% absorption, and the detection limit was about 0·02 μg./ml. with an instrumental setting convenient for routine analyses of urines. Using the scale expansion technique, the detection limit was below 0·01 μg./ml., but it was found easier to determine urinary lead concentrations below 0·05 μg./ml. by concentrating the lead in the organic solvent by increasing the volume of urine or decreasing that of the solvent. The method was applied to fresh urines, stored urines, and to urines, obtained during treatment with chelating agents, of patients with lead poisoning. Urines with added inorganic lead were not used. The results agreed well with those obtained with a colorimetric dithizone extraction method (r = 0·989). The AAS method is somewhat more simple and allows the determination of smaller lead concentrations. PMID:5647975

  10. Comparison of absorption, fluorescence, and polarization spectroscopy of atomic rubidium

    NASA Astrophysics Data System (ADS)

    Ashman, Seth; Stifler, Cayla; Romero, Joaquin

    2015-05-01

    An ongoing spectroscopic investigation of atomic rubidium utilizes a two-photon, single-laser excitation process. Transitions accessible with our tunable laser include 5P1 / 2F' <-- 5S1 / 2 F and 5P3 / 2F' <-- 5S1 / 2 F . The laser is split into a pump and probe beam to allow for Doppler-free measurements of transitions between hyperfine levels. The pump and probe beams are overlapped in a counter-propagating geometry and the laser frequency scans over a transition. Absorption, fluorescence and polarization spectroscopy techniques are applied to this basic experimental setup. The temperature of the vapor cell and the power of the pump and probe beams have been varied to explore line broadening effects and signal-to-noise of each technique. This humble setup will hopefully grow into a more robust experimental arrangement in which double resonance, two-laser excitations are used to explore hyperfine state changing collisions between rubidium atoms and noble gas atoms. Rb-noble gas collisions can transfer population between hyperfine levels, such as 5P3 / 2 (F' = 3) <-- Collision 5P3 / 2 (F ' = 2) , and the probe beam couples 7S1 / 2 (F'' = 2) <-- 5P3 / 2 (F' = 3) . Polarization spectroscopy signal depends on the rate of population transfer due to the collision as well as maintaining the orientation created by the pump laser. Fluorescence spectroscopy relies only on transfer of population due to the collision. Comparison of these techniques yields information regarding the change of the magnetic sublevels, mF, during hyperfine state changing collisions.

  11. Atomic absorption background of Ba in EXAFS analysis of BaFe(12)O(19) nanoparticles.

    PubMed

    Padeznik Gomilšek, Jana; Kodre, Alojz; Arčon, Iztok; de Panfilis, Simone; Makovec, Darko

    2011-07-01

    The approximate barium X-ray atomic absorption in the energy region of L-edges is reconstructed from the absorption spectrum of an aqueous solution of BaCl(2). The result is corroborated by comparison with pure atomic absorption spectra of neighbour elements Xe and Cs. The application of the atomic absorption signal as a proper EXAFS background is demonstrated and discussed in the analysis of Ba hexaferrite nanoparticles with a very weak structural signal. The essential gain is found in the decrease of uncertainty intervals of structural parameters and their correlations. A simple analytical model of the absorption background for the practical EXAFS analysis is demonstrated.

  12. [Measurement of atomic number of alkali vapor and pressure of buffer gas based on atomic absorption].

    PubMed

    Zheng, Hui-jie; Quan, Wei; Liu, Xiang; Chen, Yao; Lu, Ji-xi

    2015-02-01

    High sensitivitymagnetic measurementscanbe achieved by utilizing atomic spinmanipulation in the spin-exchange-relaxation-free (SERF) regime, which uses an alkali cell as a sensing element. The atomic number density of the alkali vapor and the pressure of the buffer gasare among the most important parameters of the cell andrequire accurate measurement. A method has been proposed and developedto measure the atomic number density and the pressure based on absorption spectroscopy, by sweeping the absorption line and fittingthe experiment data with a Lorentzian profile to obtainboth parameters. Due to Doppler broadening and pressure broadening, which is mainly dominated by the temperature of the cell and the pressure of buffer gas respectively, this work demonstrates a simulation of the errorbetween the peaks of the Lorentzian profile and the Voigt profile caused by bothfactors. The results indicates that the Doppler broadening contribution is insignificant with an error less than 0.015% at 313-513 K for a 4He density of 2 amg, and an error of 0.1% in the presence of 0.6-5 amg at 393 K. We conclude that the Doppler broadening could be ignored under above conditions, and that the Lorentzianprofile is suitably applied to fit the absorption spectrumobtainingboth parameters simultaneously. In addition we discuss the resolution and the instability due to thelight source, wavelength and the temperature of the cell. We find that the cell temperature, whose uncertainty is two orders of magnitude larger than the instability of the light source and the wavelength, is one of the main factors which contributes to the error.

  13. Etalon-induced baseline drift and correction in atom flux sensors based on atomic absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Du, Yingge; Chambers, Scott A.

    2014-10-01

    Atom flux sensors based on atomic absorption (AA) spectroscopy are of significant interest in thin film growth as they can provide unobtrusive, element specific real-time flux sensing and control. The ultimate sensitivity and performance of these sensors are strongly affected by baseline drift. Here we demonstrate that an etalon effect resulting from temperature changes in optical viewport housings is a major source of signal instability, which has not been previously considered, and cannot be corrected using existing methods. We show that small temperature variations in the fused silica viewports can introduce intensity modulations of up to 1.5% which in turn significantly deteriorate AA sensor performance. This undesirable effect can be at least partially eliminated by reducing the size of the beam and tilting the incident light beam off the viewport normal.

  14. Etalon-induced baseline drift and correction in atom flux sensors based on atomic absorption spectroscopy

    SciTech Connect

    Du, Yingge; Chambers, Scott A.

    2014-10-20

    Atom flux sensors based on atomic absorption (AA) spectroscopy are of significant interest in thin film growth as they can provide unobtrusive, element specific real-time flux sensing and control. The ultimate sensitivity and performance of these sensors are strongly affected by baseline drift. Here we demonstrate that an etalon effect resulting from temperature changes in optical viewport housings is a major source of signal instability, which has not been previously considered, and cannot be corrected using existing methods. We show that small temperature variations in the fused silica viewports can introduce intensity modulations of up to 1.5% which in turn significantly deteriorate AA sensor performance. This undesirable effect can be at least partially eliminated by reducing the size of the beam and tilting the incident light beam off the viewport normal.

  15. Etalon-induced Baseline Drift And Correction In Atom Flux Sensors Based On Atomic Absorption Spectroscopy

    SciTech Connect

    Du, Yingge; Chambers, Scott A.

    2014-10-20

    Atom flux sensors based on atomic absorption (AA) spectroscopy are of significant interest in thin film growth as they can provide unobtrusive, element specific, real-time flux sensing and control. The ultimate sensitivity and performance of the sensors are strongly affected by the long-term and short term baseline drift. Here we demonstrate that an etalon effect resulting from temperature changes in optical viewport housings is a major source of signal instability which has not been previously considered or corrected by existing methods. We show that small temperature variations in the fused silica viewports can introduce intensity modulations of up to 1.5%, which in turn significantly deteriorate AA sensor performance. This undesirable effect can be at least partially eliminated by reducing the size of the beam and tilting the incident light beam off the viewport normal.

  16. Amélioration, par emploi de tensio-actifs, de la sensibilité et de la répétabilité Du Dosage Du plomb en spectrométrie d'absorption atomique avec atomisation électrothermique

    NASA Astrophysics Data System (ADS)

    de La Guardia, M.; Durrieu, F.; Voïnovitch, I. A.; Louvrier, J.

    In order to improve the sensitivity and repeatability of lead determinations by electrothermal atomic absorption spectrometry, the effect of some surface active agents as well as the influence of the length of the graphite furnaces (Varian CRA 90) were studied. It was shown that by adding about 0.02 % Triton X-100 and by using 12mm long tubes (instead of 9mm) the sensitivity and repeatability of the lead determination was improved by about 30 %, at the 0.6 ng ml -1 level. These advantages can be attributed, at first, to the decrease of the surface tension of the analysed solutions, this favouring a more regular lining of the tube internal surface and, secondly, to the elongation of the absorption path. The effects of the surface active agents, on the physical properties of the solutions, were followed up by measurements of the surface tension, the contact angle and the diameter and height of the drops. By means of a Castaing microprobe it was possible to examine the distribution and the diffusiveness of the sample on the surface of the tubes. Finally, it was shown that on the IL Fastac system, the addition of non-ionic surface active agents does not bring about an improvement in precision; instead, a 300% increase in the sensitivity was observed, probably due to an improvement in the nebulization flow.

  17. Quantitative IR microscopy and spectromics open the way to 3D digital pathology.

    PubMed

    Bobroff, Vladimir; Chen, Hsiang-Hsin; Delugin, Maylis; Javerzat, Sophie; Petibois, Cyril

    2016-06-01

    Currently, only mass-spectrometry (MS) microscopy brings a quantitative analysis of chemical contents of tissue samples in 3D. Here, the reconstruction of a 3D quantitative chemical images of a biological tissue by FTIR spectro-microscopy is reported. An automated curve-fitting method is developed to extract all intense absorption bands constituting IR spectra. This innovation benefits from three critical features: (1) the correction of raw IR spectra to make them quantitatively comparable; (2) the automated and iterative data treatment allowing to transfer the IR-absorption spectrum into a IR-band spectrum; (3) the reconstruction of an 3D IR-band matrix (x, y, z for voxel position and a 4(th) dimension with all IR-band parameters). Spectromics, which is a new method for exploiting spectral data for tissue metadata reconstruction, is proposed to further translate the related chemical information in 3D, as biochemical and anatomical tissue parameters. An example is given with oxidative stress distribution and the reconstruction of blood vessels in tissues. The requirements of IR microscopy instrumentation to propose 3D digital histology as a clinical routine technology is briefly discussed.

  18. Determination of Aluminum Concentration in Seawater by Colorimetry and Atomic Absorption Spectroscopy.

    DTIC Science & Technology

    1972-11-30

    this was also high. 5 . ,Irj ~ - • lri*; llo. TALLE 2 ATOMIC ABSORPTION SPECTROSCOPY DETEPIJINATION OF ALUMINU1 CONCENTRATIO11 OF SEAWATER OCEAN...Concentration in Seawater by Colorimetr-y and Atomic Absorption Spectroscopy Charles A. Greene, Jr. and Everett N. Jones Ocean Science Department T14

  19. [Indirect determination of Vc with flame atomic absorption spectrometry].

    PubMed

    Dong, Zhen-Ming; Yin, Hai-Long; Zheng, Yang-Zhen; Sun, Qing-Ling; Zhang, Yong

    2007-09-01

    In the present paper, a new method for indirect determination of Vc by atomic absorption spectrometry is proposed, based on the reducing properties of Ag+. The effects of temperature, reaction time and use level of Ag+ on the experiment were studied. Room-temperature and reaction time of 35 minutes were chosen. The oxidant amount is 2.0 mL solution of Ag+ (1.0 microg mL(-1)). Meanwhile the AAS working conditions for Ag determination were optimized. The proposed method allows the determination of Vc in a wide range with a relative standard deviation of 2.04%, and the detection limit is less than 1 microg x mL(-1). The method cannot be disturbed by the colour of sample. The interference of coexistent substance is also weak. Other methods for determining Vc could be remedied by this method. Two kinds of standard curves were plotted, standard working curve of sliver and standard working curve of Vc. The former is easier, while the latter is more accurate and could be applied flexibly according to the physical circumstances. This method is easy to control and has been applied to the determination of ascorbic acid in pharmaceutical preparations and orange juice. The recovery ratio of this method is 99.30%-106.06%. The results obtained in the analysis agreed well with the iodimetry in pharmacopeia.

  20. Determination of gold in geologic materials by solvent extraction and atomic-absorption spectrometry

    USGS Publications Warehouse

    Huffman, Claude; Mensik, J.D.; Riley, L.B.

    1967-01-01

    The two methods presented for the determination of traces of gold in geologic materials are the cyanide atomic-absorption method and the fire-assay atomic-absorption method. In the cyanide method gold is leached with a sodium-cyanide solution. The monovalent gold is then oxidized to the trivalent state and concentrated by extracting into methyl isobutyl ketone prior to estimation by atomic absorption. In the fire-assay atomic-absorption method, the gold-silver bead obtained from fire assay is dissolved in nitric and hydrochloric acids. Gold is then concentrated by extracting into methyl isobutyl ketone prior to determination by atomic absorption. By either method concentrations as low as 50 parts per billion of gold can be determined in a 15-gram sample.

  1. Feasibility of filter atomization in high-resolution continuum source atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Heitmann, Uwe; Becker-Ross, Helmut; Katskov, Dmitri

    2006-03-01

    A prototype spectrometer for high-resolution continuum source atomic absorption spectrometry (HR-CS AAS), built at ISAS Berlin, Germany, was combined with a graphite filter atomizer (GFA), earlier developed at TUT, Pretoria, South Africa. The furnace and auto-sampler units from a commercial AA spectrometer, model AAS vario 6 (Analytik Jena AG, Jena, Germany), were employed in the instrument. Instead of conventional platform tube, the GFA was used to provide low measurement susceptibility to interferences and short determination cycle. The GFA was modified according to the design of the furnace unit and optimal physical parameters of its components (filter and collector) found. Afterwards, optimal GFA was replicated and tested to outline analytical performances of the HR-CS GFA AA spectrometer in view of prospects of multi-element analysis. In particular, reproducibility of performances, repeatability of analytical signals, lifetime, temperature limit and duration of the measurement cycle were examined, and elements available for determination justified. The results show that the peak area of the atomic absorption signal is reproduced in various GFA copies within ± 4% deviation range. The GFA can stand temperatures of 2800 °C with 6 s hold time for 55 temperature cycles, and 2700 °C (8 s) for about 200 cycles. Only the external tube is prone to destruction while the filter and collector do not show any sign of erosion caused by temperature or aggressive matrix. Analytical signals are affected insignificantly by tube aging. Repeatability of the peak area remains within 1.1-1.7% RSD over more than hundred determination cycles. Peak areas are proportional to the sample volume of injected organic and inorganic liquids up to at least 50 μL. The drying stage is combined with hot sampling and cut down to 15-20 s. The list of metals available for determination with full vapor release includes Al, Co, Cr, Ni, Pt as well as more volatile metals. Characteristic masses at

  2. Midinfrared absorption measured at a lambda/400 resolution with an atomic force microscope.

    PubMed

    Houel, Julien; Homeyer, Estelle; Sauvage, Sébastien; Boucaud, Philippe; Dazzi, Alexandre; Prazeres, Rui; Ortéga, Jean-Michel

    2009-06-22

    Midinfrared absorption can be locally measured using a detection combining an atomic force microscope and a pulsed excitation. This is illustrated for the midinfrared bulk GaAs phonon absorption and for the midinfrared absorption of thin SiO(2) microdisks. We show that the signal given by the cantilever oscillation amplitude of the atomic force microscope follows the spectral dependence of the bulk material absorption. The absorption spatial resolution achieved with microdisks is around 50 nanometer for an optical excitation around 22 micrometer wavelength.

  3. Temporal variation in gas temperature at the atomization stage in several types of graphite furnaces for atomic absorption spectrometry.

    PubMed

    Ashino, Tetsuya; Shimabukuro, Haruki; Morimoto, Shun; Wagatsuma, Kazuaki

    2009-10-01

    In order to compare and evaluate the atomization process occurring in several types of graphite furnaces for atomic absorption spectrometry, the authors estimated temporal variations in the gas temperature by using a two-line method under the assumption of a Bolzmann distribution. The atomization furnaces employed were a graphite tube, a graphite tube coated with pyrolitic carbon, a graphite tube with a platform and a graphite cup. Differences in the temporal variation in the gas temperature among these graphite furnaces were observed.

  4. Uranium isotopes quantitatively determined by modified method of atomic absorption spectrophotometry

    NASA Technical Reports Server (NTRS)

    Lee, G. H.

    1967-01-01

    Hollow-cathode discharge tubes determine the quantities of uranium isotopes in a sample by using atomic absorption spectrophotometry. Dissociation of the uranium atoms allows a large number of ground state atoms to be produced, absorbing the incident radiation that is different for the two major isotopes.

  5. Electrothermal atomic absorption spectrophotometry of nickel in tissue homogenates

    SciTech Connect

    Sunderman, F.W. Jr.; Marzouk, A.; Crisostomo, M.C.; Weatherby, D.R.

    1985-01-01

    A method for analysis of Ni concentrations in tissues is described, which involves (a) tissue dissection with metal-free obsidian knives, (b) tissue homogenization in polyethylene bags by use by a Stomacher blender, (c) oxidative digestion with mixed nitric, sulfuric, and perchloric acids, and (d) quantitation of Ni by electrothermal atomic absorption spectrophotometry with Zeeman background correction. The detection limit for Ni in tissues is 10 ng per g, dry weight; the coefficient of variation ranges from 7 to 15%, depending on the tissue Ni concentration; the recovery of Ni added in concentration of 20 ng per g, dry weight, to kidney homogenates averages 101 +/- 8% (mean +/-SD). In control rats, Ni concentrations are highest in lung (102 +/- 39 ng per g, dry weight) and lowest in spleen (35 +/- 16 ng per g, dry wt.). In descending order of Ni concentrations, the tissues of control rats rank as follows: lung > heart > bone > kidney > brain > testis > fat > liver > spleen. In rats killed 24 h after sc injection of NiCl/sub 2/ (0.125 mmol per kg, body weight) Ni concentrations are highest in kidney (17.7 +/- 2.5 ..mu..g per g, dry weight) and lowest in brain (0.38 +/- 0.14 ..mu..g per g, dry weight). In descending order of Ni concentrations, the tissues of NiCl/sub 2/-treated rats rank as follows: kidney >> lung > spleen > testis > heart > fat > liver > bone > brain. The present method fills the need for an accurate, sensitive, and practical technique to determine tissue Ni concentrations, with stringent precautions to minimize Ni contamination during tissue sampling and processing. 35 references, 5 figures, 1 table.

  6. Atomic-absorption determination of beryllium in geological materials by use of electrothermal atomization

    USGS Publications Warehouse

    Campbell, E.Y.; Simon, F.O.

    1978-01-01

    A method is described for the atomic-absorption determination of beryllium in geological materials, that utilizes electrothermal atomization after a separation by solvent extraction. Samples are decomposed with hydrofluoric acid and nitric acid in Teflon-lined pressure decomposition vessels. Beryllium is isolated by its extraction as beryllium acetylacetonate at pH 8 into xylene and back-extraction in 3M hydrochloric acid. The method has been successfully applied to the determination of beryllium in 14 U.S. Geological Survey standard rocks. Four subsamples from four bottles of each standard sample were analysed in random order. The mean beryllium contents (ppm) are: AGV-1, 1.98; PCC-1, 0.024; MAG-1, 2.84; BHVO-1, 0.90; DTS-1, 0.026; SCo-1, 1.74; SDC-1, 2.52; BCR-1, 1.44; GSP-1, 1.22; SGR-1, 0.86; QLO-1, 1.83; RGM-1, 2.21; STM-1, 8.75; G-2, 2.29. An analysis of variance shows that all the samples may be considered homogeneous at F0.95 except AGV-1 and DTS-1 which may be considered homogeneous at F0.99. ?? 1978.

  7. Determination of tin in poly(vinyl chloride) by atomic-absorption spectroscopy.

    PubMed

    Anwar, J; Marr, I L

    1982-10-01

    A simple procedure is described for the determination of tin in PVC by atomic-absorption spectroscopy with an air-hydrogen flame, after wet digestion of the sample with sulphuric acid and hydrogen peroxide.

  8. DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

    EPA Science Inventory

    A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and
    compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

  9. EPA Method 245.1: Determination of Mercury in Water by Cold Vapor Atomic Absorption Spectrometry

    EPA Pesticide Factsheets

    SAM lists this method for preparation and analysis of aqueous liquid and drinking water samples. This method will determine mercuric chloride and methoxyethylmercuric acetate as total mercury using cold vapor atomic absorption spectrometry.

  10. DETERMINATION OF TOTAL MERCURY IN FISH TISSUES USING PYROLYSIS ATOMIC ABSORPTION SPECTROMETRY WITH GOLD AMALGAMATION

    EPA Science Inventory

    A simple and rapid procedure for measuring total mercury in fish tissues is evaluated and
    compared with conventional techniques. Using an automated instrument incorporating combustion, preconcentration by amalgamation with gold, and atomic absorption spectrometry (AAS), mill...

  11. Determination of urinary manganese by the direct chelation-extraction method and flameless atomic absorption spectrophotometry.

    PubMed Central

    Watanabe, T; Tokunaga, R; Iwahana, T; Tati, M; Ikeda, M

    1978-01-01

    The direct chelation-extraction method, originally developed by Hessel (1968) for blood lead analysis, has been successfully applied to urinalysis for manganese. The analyses of 35 urine samples containing up to 100 microgram/1 of manganese from manganese-exposed workers showed that the data obtained by this method agree well with those by wet digestion-flame atomic absorption spectrophotometry and also by flameless atomic absorption spectrophotometry. PMID:629893

  12. Vacuum Ultraviolet Absorption Measurements of Atomic Oxygen in a Shock Tube

    NASA Technical Reports Server (NTRS)

    Meyer, Scott Andrew

    1995-01-01

    The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the Electric Arc-driven Shock Tube (EAST) Facility at NASA-Ames Research Center. This investigation demonstrates the instrumentation required to determine atomic oxygen concentrations from absorption measurements in impulse facilities. A shock wave dissociates molecular oxygen, producing a high temperature sample of atomic oxygen in the shock tube. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the atomic line at 130.49 nm. The line shape function is determined from measurements at atomic oxygen densities of 3x10(exp 17) and 9x10(exp 17) cm(exp -3). The broadening coefficient for resonance interactions is deduced from this data, and this value is in accord with available theoretical models.

  13. Vacuum Ultraviolet Absorption Measurements of Atomic Oxygen in a Shock Tube

    NASA Technical Reports Server (NTRS)

    Meyer, Scott Andrew

    1995-01-01

    The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the Electric Arc-driven Shock Tube (EAST) Facility at NASA-Ames Research Center. This investigation demonstrates the instrumentation required to determine atomic oxygen concentrations from absorption measurements in impulse facilities. A shock wave dissociates molecular oxygen, producing a high temperature sample of atomic oxygen in the shock tube. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the atomic line at 130.49 nm. The line shape function is determined from measurements at atomic oxygen densities of 3 x 10(exp 17) and 9 x 10(exp 17) cm(exp -3). The broadening coefficient for resonance interactions is deduced from this data, and this value is in accord with available theoretical models.

  14. Vacuum Ultraviolet Absorption Measurements of Atomic Oxygen in a Shock Tube

    NASA Technical Reports Server (NTRS)

    Meyer, Scott Andrew

    1995-01-01

    The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the Electric Arc-driven Shock Tube (EAST) Facility at NASA-Ames Research Center. This investigation demonstrates the instrumentation required to determine atomic oxygen concentrations from absorption measurements in impulse facilities. A shock wave dissociates molecular oxygen, producing a high temperature sample of atomic oxygen in the shock tube. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the atomic line at 130.49 nm. The line shape function is determined from measurements at atomic oxygen densities of 3 x 10(exp 17) and 9 x 10(exp 17)/cu cm. The broadening coefficient for resonance interactions is deduced from this data, and this value is in accord with available theoretical models.

  15. Vacuum Ultraviolet Absorption Measurements of Atomic Oxygen in a Shock Tube

    NASA Technical Reports Server (NTRS)

    Meyer, Scott Andrew

    1995-01-01

    The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the Electric Arc-driven Shock Tube (EAST) Facility at NASA-Ames Research Center. This investigation demonstrates the instrumentation required to determine atomic oxygen concentrations from absorption measurements in impulse facilities. A shock wave dissociates molecular oxygen, producing a high temperature sample of atomic oxygen in the shock tube. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the atomic line at 130.49 nm. The line shape function is determined from measurements at atomic oxygen densities of 3 x 10(exp 17) and 9 x 10(exp 17)/cu cm. The broadening coefficient for resonance interactions is deduced from this data, and this value is in accord with available theoretical models.

  16. Measurement of aluminum in neuronal tissues using electrothermal atomization atomic absorption spectrophotometry

    SciTech Connect

    Pierson, K.B.; Evenson, M.A.

    1986-07-01

    Studies characterizing aluminum complexes isolated from neuronal tissues require accurate and precise techniques for aluminum measurement. A solution of 0.01 M nitric acid containing 0.2% Triton X-100 was the optimal diluent for aluminum measurement under the experimental conditions used. Three National Bureau of Standards Standard Reference Materials (SRM) were digested, and the aluminum concentration of each was measured with a Perkin-Elmer 503 atomic absorption spectrophotometer equipped with a Perkin-Elmer HGA 2100 controller. The calculated detection limit of aluminum was 120 pg using 15-..mu..L sample injections (8 ..mu..g/L). Aluminum concentrations present in citrus leaves (SRM 1572), pine needles (SRM 1575), and tomato leaves (SRM 1573) were 100 +- 12 (certified value, 92 +- 15), 522 +- 45 (certified value, 454 +- 30), and 1273 +- 112 (provisional value, 1200) ..mu..g/g, respectively. The within- and between-day precision had coefficients of variation for citrus leaves, pine needles, and tomato leaves of 18 and 12%, 6.3 and 8.6%, and 3.7 and 8.7%, respectively. Aluminum absorbance was enhanced at high pH values and by zinc.

  17. Intracavity absorption and emission spectroscopy of atoms in pulsed gas discharges

    SciTech Connect

    Serdyukov, V. I.; Poplavskii, Yu. A.; Sinitsa, L. N.

    2009-07-15

    Absorption and emission spectra of U and Na atoms in the 590-nm spectral range were studied experimentally using pulsed hollow-cathode gas discharges. The spectra were recorded with a high-sensitivity intracavity laser spectrometer. The possibility of generating coherent emission on atomic emission lines in gas-discharge plasmas was demonstrated experimentally.

  18. Disentangling atomic-layer-specific x-ray absorption spectra by Auger electron diffraction spectroscopy

    NASA Astrophysics Data System (ADS)

    Matsui, Fumihiko; Matsushita, Tomohiro; Kato, Yukako; Hashimoto, Mie; Daimon, Hiroshi

    2009-11-01

    In order to investigate the electronic and magnetic structures of each atomic layer at subsurface, we have proposed a new method, Auger electron diffraction spectroscopy, which is the combination of x-ray absorption spectroscopy (XAS) and Auger electron diffraction (AED) techniques. We have measured a series of Ni LMM AED patterns of the Ni film grown on Cu(001) surface for various thicknesses. Then we deduced a set of atomic-layer-specific AED patterns in a numerical way. Furthermore, we developed an algorithm to disentangle XANES spectra from different atomic layers using these atomic-layer-specific AED patterns. Surface and subsurface core level shift were determined for each atomic layer.

  19. Atomic structure of machined semiconducting chips: An x-ray absorption spectroscopy study

    SciTech Connect

    Paesler, M.; Sayers, D.

    1988-12-01

    X-ray absorption spectroscopy (XAS) has been used to examine the atomic structure of chips of germanium that were produced by single point diamond machining. It is demonstrated that although the local (nearest neighbor) atomic structure is experimentally quite similar to that of single crystal specimens information from more distant atoms indicates the presence of considerable stress. An outline of the technique is given and the strength of XAS in studying the machining process is demonstrated.

  20. Application of a multi-pass absorption cell for measurement of sputtered tungsten atoms' density

    NASA Astrophysics Data System (ADS)

    Blagoev, A.; Pashov, A.; Stanev, A.; Bozhinova, I.; Rusinov, I.

    2010-01-01

    A dedicated gas discharge tube equipped with a hollow cathode made of tungsten is setup for sputtering of W atoms. A multi-pass White type absorption cell is designed to increase the sensitivity of the absorption method. The optical system consists of three externally mounted aluminium-coated spherical mirrors with 70 cm radius of curvature. Measurements of the cell relative transmittance in the UV and visible spectral regions are carried out. Time-resolved measurements of sputtered ground-state tungsten atoms' density in 2-pass configuration, as well as assessment of the diffusion coefficient of these atoms in argon at 350 K temperature are made.

  1. Determination of cadmium in biodiesel using microemulsion and electrothermal atomization atomic absorption spectrometry.

    PubMed

    Lima, Adriana S; Silva, Deise G; Teixeira, Leonardo S G

    2015-01-01

    This work aimed to prepare biodiesel microemulsions for the subsequent quantification of cadmium via graphite furnace atomic absorption spectrometry (GFAAS). The biodiesel samples were prepared using n-propanol as an emulsifier, 10% (v/v) nitric acid as the aqueous phase, and biodiesel. Pseudoternary phase diagrams were constructed to determine the microemulsion region with the specified components. The optimized conditions for microemulsion formation were 57.6% (v/v) n-propanol, 21.2% (v/v) biodiesel, and 21.2% (v/v) nitric acid solution. The stability of the microemulsified system was investigated using aqueous and organic standards, and the system was found to be stable for at least 240 min. The applied pyrolysis and atomization temperatures were 800 and 2000 °C, respectively, and 5 μg of aluminum was used as the chemical modifier. The obtained limits of detection and quantification were 0.2 and 0.5 μg kg(-1), respectively, and the characteristic mass was 1.6 pg. The precision, expressed as the relative standard deviation (% R.S.D., n = 10), was 2.5% for a sample with a cadmium concentration of 6.5 μg kg(-1). The accuracy was determined from addition and recovery experiments, with results varying from 93 to 108% recovery. This study demonstrates that the proposed method based on the use of a microemulsion formation in sample preparation can be applied as an efficient alternative for the determination of cadmium in biodiesel by GFAAS. Cadmium determination in biodiesel samples of different origins (soybean, corn, cotton, and sunflower) was evaluated after acid digestion using the inductively coupled plasma-mass spectrometry (ICP-MS) technique, and the obtained results were compared to the results obtained using the proposed method. The paired t test (95% confidence level) did not show significant differences. The concentrations of cadmium found ranged from 5.3 to 8.0 μg kg(-1).

  2. Nonresonance multipulse inversion and energy absorption by an atom

    SciTech Connect

    Moiseev, S.A.; Shtyrkov, E.I.

    1995-09-01

    It is shown on the basis of the quasi-classical approach that under an optical pumping, a two-level system of atoms can be transferred exactly to an upper state by the optical field even when the Fourier component resonant to a given transition is completely absent in this pumping field. 5 refs.

  3. Targeting Inaccurate Atomic Data in the Eta Car Ejecta Absorption

    NASA Technical Reports Server (NTRS)

    Nielsen, K. E.; Kober, G. Vieira; Gull, T. R.; Blackwell-Whitehead, R.; Nilsson, H.

    2006-01-01

    The input from the laboratory spectroscopist community has on many occasions helped the analysis of the eta Car spectrum. Our analysis has targeted spectra where improved wavelengths and oscillator strengths are needed. We will demonstrate how experimentally derived atomic data have improved our spectral analysis, and illuminate where more work still is needed.

  4. Gold volatile species atomization and preconcentration in quartz devices for atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Arslan, Yasin; Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan; Dědina, Jiří

    2015-01-01

    The on-line atomization of gold volatile species was studied and the results were compared with thermodynamic calculations in several quartz atomizers, namely: diffusion flame, flame-in-gas-shield, flame-in-plain-tube, externally heated T-tube and externally heated flame-in-T-tube. Atomization mechanism in the explored devices is proposed, where volatile species are converted to thermodynamically stable AuH at elevated temperature over 500 °C and then atomized by an interaction with a cloud of hydrogen radicals. Because of its inherent simplicity and robustness, diffusion flame was employed as a reference atomizer. It yielded atomization efficiency of 70 to 100% and a very good long time reproducibility of peak area sensitivity: 1.6 to 1.8 s μg- 1. Six and eleven times higher sensitivity, respectively, was provided by atomizers with longer light paths in the observation volume, i.e. externally heated T-tube and externally heated flame-in-T-tube. The latter one, offering limit of detection below 0.01 μg ml- 1, appeared as the most prospective for on-line atomization. Insight into the mechanism of atomization of gold volatile species, into the fate of free atoms and into subsequent analyte transfer allowed to assess possibilities of in-atomizer preconcentration of gold volatile species: it is unfeasible with quartz atomizers but a sapphire tube atomizer could be useful in this respect.

  5. Atomic absorption determination of tin in foods: collaborative study.

    PubMed

    Elkins, E R; Sulek, A

    1979-09-01

    Samples of green beans, applesauce, and a fruit juice were fortified with tin at 3 levels. Collaborators were asked to digest the samples, using HNO3-H2SO4, add methanol to enhance the absorption signal, and aspirate directly, using a nitrous oxide-acetylene flame. Results were received from 8 laboratories including 4 from Europe. However, only 6 laboratories used the prescribed methodology. All results were considered acceptable. The method has been adopted as interim official first action.

  6. Absorption of infrared radiation by electrons in the field of a neutral hydrogen atom

    NASA Technical Reports Server (NTRS)

    Stallcop, J. R.

    1974-01-01

    An analytical expression for the absorption coefficient is developed from a relationship between the cross-section for inverse bremsstrahlung absorption and the cross-section for electron-atom momentum transfer; it is accurate for those photon frequencies v and temperatures such that hv/kT is small. The determination of the absorption of infrared radiation by free-free transitions of the negative hydrogen ion has been extended to higher temperatures. A simple analytical expression for the absorption coefficient has been derived.

  7. Absorption of infrared radiation by electrons in the field of a neutral hydrogen atom

    NASA Technical Reports Server (NTRS)

    Stallcop, J. R.

    1974-01-01

    An analytical expression for the absorption coefficient is developed from a relationship between the cross-section for inverse bremsstrahlung absorption and the cross-section for electron-atom momentum transfer; it is accurate for those photon frequencies v and temperatures such that hv/kT is small. The determination of the absorption of infrared radiation by free-free transitions of the negative hydrogen ion has been extended to higher temperatures. A simple analytical expression for the absorption coefficient has been derived.

  8. Flameless Atomic Absorption Spectroscopy: Effects of Nitrates and Sulfates.

    DTIC Science & Technology

    1980-05-01

    oxide by graphite followed by sublimation of the metal. Frech and Cedergren investigated high temperature equilibria in graphite furnace atomizers. 1 4...Acta, 72, 49 (1974). 13. R.E. Sturgeon, C.L. Chakrabarti, and C.H. Langford, Anal. Chem., 48, 1792 (1976). 14. W. Frech and A. Cedergren , Anal. Chim...Acta, 82, 83 (1976). 15. W. Frech, Anal. Chim. Acta, 77, 43 (1975). 16. W. Frech and A. Cedergren , Anal. Chim. Acta, 88, 57 (1977). CHAPTER III

  9. Chlorine analysis by diode laser atomic absorption spectrometry.

    PubMed

    Koch, J; Zybin, A; Niemax, K

    2000-04-01

    The general characteristics of Diode Laser Absorption Spectrometry (DLAAS) in low pressure plasmas particularly with respect to the detection of non-metals are comprehensively recapitulated and discussed. Furthermore, a detector, which is based on DLAAS in a microwave-induced low pressure plasma as an alternative technique for halogene-specific analysis of volatile compounds and polymeric matrices is described. The analytical capability of the technique is demonstrated on the chlorine-specific analysis of ablated polymer fragments as well as gas chromatographically separated hydrocarbons. Since the measurements were carried out by means of a balanced-heterodyne detection scheme, different technical noise contributions, such as laser excess and RAM noise could efficiently be suppressed and the registered absorption was limited only by the principal shot noise. Thus, in the case of the polymer analysis a chlorine-specific absolute detection limit of 10 pg could be achieved. Furthermore, fundamental investigations concerning the influence of hydrocarbons on the dissociation capability of the microwave induced plasma were performed. For this purpose, the carbon-, chlorine- and hydrogen-specific stoichiometry of the compounds were empirically determined. Deviations from the expected proportions were found to be insignificant, implying the possibility of internal standardization relative to the response of a reference sample.

  10. Atomic and molecular absorption in redshifted radio sources

    NASA Astrophysics Data System (ADS)

    Curran, S. J.; Whiting, M. T.; Allison, J. R.; Tanna, A.; Sadler, E. M.; Athreya, R.

    2017-06-01

    We report on a survey for associated H I 21-cm and OH 18-cm absorption with the Giant Metrewave Radio Telescope at redshifts z ≈ 0.2-0.4. Although the low-redshift selection ensures that our targets are below the critical ultraviolet luminosity (LUV ˜ 1023 W Hz-1), which is hypothesized to ionize all of the neutral gas in the host galaxy, we do not obtain any detection in the six sources searched. Analysing these in context of the previous surveys, in addition to the anticorrelation with the ultraviolet luminosity (ionizing photon rate), we find a correlation between the strength of the absorption and the blue-near-infrared colour, as well as the radio-band turnover frequency. We believe that these are due to the photoionization of the neutral gas, an obscured sightline being more conducive to the presence of cold gas and the compact radio emission being better intercepted by the absorbing gas, maximizing the flux coverage, respectively. Regarding the photoionization, the compilation of the previous surveys increases the significance of the critical ionizing photon rate, above which all of the gas in the host galaxy is hypothesized to be ionized (Q_{H I ≈ 3× 10^{56} s-1), to >5σ. This reaffirms that this is an ubiquitous effect, which has profound implications for the detection of neutral gas in these objects with the Square Kilometre Array.

  11. Determination of antimony by using tungsten trap atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Titretir, Serap; Kendüzler, Erdal; Arslan, Yasin; Kula, İbrahim; Bakırdere, Sezgin; Ataman, O. Yavuz.

    2008-08-01

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH 3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 °C. Following the preconcentration step, the trap is heated to 895 °C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH 4 solutions, H 2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l - 1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17.

  12. Study of the analytical methods for iron determination in complex organic liquids by atomic absorption spectrometry

    SciTech Connect

    Torre, M.; Gonzalez, M.C.; Jimenez, O.; Rodriquez, A.R. )

    1990-01-01

    In the determination of iron in complex organic liquids by atomic absorption spectrometry (A.A.S.), methods of sample preparation, such as dilution with an organic solvent and sample pretreatment to destroy organic material, are investigated. Moreover, methods of analysis using calibration curve and standard additions are presented. The possible cause of error associated with iron determination in organic samples by flame (F-A.A.S.) and graphite furnace (GF-A.A.S.) atomic absorption spectrometry are discussed. From all of these studies, the use of graphite furnace atomic absorption spectrometry after sample dilution with methyl isobutyl ketone, and the use of the method of standard additions are advised for iron determination.

  13. Interlaboratory comparisons of nickel analyses in urine by atomic absorption spectrometry.

    PubMed

    Adams, D B; Brown, S S; Sunderman, F W; Zachariasen, H

    1978-06-01

    Two interlaboratory surveys of urine nickel analyses were performed in which eight or nine urine samples were distributed to laboratories in seven nations for measurements of nickel concentrations by atomic absorption spectrometry. In both surveys, wide discrepancies were observed in the values for urine nickel concentrations that were obtained in different laboratories by various analytical methods. This finding documents a serious need for improvement in the proficiency of nickel analyses. Nonetheless, excellent interlaboratory concordance was found in the rankings of urine samples in order of increasing nickel concentrations. Analytical techniques that involved preliminary wet or dry ashing and extration steps before flameless atomic absorption spectrometry were generally superior to techniques for direct analysis of urine by flameless atomic absorption spectrometry in respect to (a) analytical sensitivity, (b) recovery of added nickel, (c) interlaboratory precision, and (d) interlaboratory concordance of ranking of urine samples in order of increasing nickel concentrations.

  14. [Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr].

    PubMed

    Zhong, L X; Ding, B M; Jiang, D; Liu, D Y; Yu, B; Zhu, B L; Ding, L

    2016-05-20

    To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry. Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection. Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co. The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

  15. Infrared absorption on a complex comprising three equivalent hydrogen atoms in ZnO

    NASA Astrophysics Data System (ADS)

    Herklotz, F.; Hupfer, A.; Johansen, K. M.; Svensson, B. G.; Koch, S. G.; Lavrov, E. V.

    2015-10-01

    A hydrogen-related defect in ZnO which causes two broad IR absorption bands at 3303 and 3321 cm-1 is studied by means of infrared absorption spectroscopy and first-principles theory. In deuterated samples, the defect reveals two sharp absorption lines at 2466 and 2488 cm-1 accompanied by weaker sidebands at 2462 and 2480 cm-1. Isotope substitution experiments with varying concentrations of H and D together with polarization-sensitive measurements strongly suggest that these IR absorption lines are due to stretch local vibrational modes of a defect comprising three equivalent hydrogen atoms. The zinc vacancy decorated by three hydrogen atoms, VZnH3 , and ammonia trapped at the zinc vacancy, (NH3)Zn, are discussed as a possible origin for the complex.

  16. Metal content monitoring in Hypericum perforatum pharmaceutical derivatives by atomic absorption and emission spectrometry.

    PubMed

    Gomez, María R; Soledad, Cerutti; Olsina, Roberto A; Silva, María F; Martínez, Luis D

    2004-02-18

    Metals have been investigated in different plant materials in order to establish their normal concentration range and consider their role in plants as part of human medicinal treatment. Metal monitoring as a pattern recognition method is a promising tool in the characterization and/or standardization of phytomedicines. In the present work measurable amounts of Ca, Cu, K, Li, Mg, Mn, Na, Ni, and Zn were detected in phytopharmaceutical derivatives of Hypericum perforatum by atomic techniques. Atomic methodologies like flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS) allow reliable determination of mineral content in pharmaceutical quality control of medicinal plants. Additionally, capillary electrophoresis (CE) patterns of characteristic components (fingerprints) have been performed for the search of adulterants in phytopharmaceutical products.

  17. Micro determination of plasma and erythrocyte copper by atomic absorption spectrophotometry

    PubMed Central

    Blomfield, Jeanette; Macmahon, R. A.

    1969-01-01

    The free and total plasma copper and total erythrocyte copper levels have been determined by simple, yet sensitive and highly specific methods, using atomic absorption spectrophotometry. For total copper determination, the copper was split from its protein combination in plasma or red cells by the action of hydrochloric acid at room temperature. The liberated copper was chelated by ammonium pyrrolidine dithiocarbamate and extracted into n-butyl acetate by shaking and the organic extract was aspirated into the atomic absorption spectrophotometer flame. The entire procedure was carried out in polypropylene centrifuge tubes, capped during shaking. For the free plasma copper measurement the hydrochloric acid step was omitted. Removal of the plasma or erythrocyte proteins was found to be unnecessary, and, in addition, the presence of trichloracetic acid caused an appreciable lowering of absorption. Using a double-beam atomic absorption spectrophotometer and scale expansion × 10, micro methods have been derived for determining the total copper of plasma or erythrocytes with 0·1 ml of sample, and the free copper of plasma with 0·5 ml. The macro plasma copper method requires 2 ml of plasma and is suitable for use with single-beam atomic absorption spectrophotometers. With blood from 50 blood donors, normal ranges of plasma and erythrocyte copper have been determined. PMID:5776543

  18. Atomic absorption spectrophotometric method for determination of polydimethylsiloxane residues in pineapple juice: collaborative study.

    PubMed

    Parker, R D

    1990-01-01

    An atomic absorption spectrophotometric method for determination of polydimethylsiloxane (PDMS) residues in pineapple juice was collaboratively studied by 9 laboratories. PDMS residues are extracted from pineapple juice with 4-methyl-2-pentanone and the extracted silicone is measured by atomic absorption spectrophotometry using a nitrous oxide/acetylene flame. Collaborators analyzed 5 samples including 1 blind duplicate. Reproducibility relative standard deviations (RSDR) were 13.1% at 31 ppm, 6.9% at 18 ppm, 14.8% at 7.9 ppm, and 16.1% at 4.9 ppm PDMS. The method has been approved interim official first action by AOAC.

  19. Determination of cadmium vapor pressure over dichromium cadmium tetraselenide by the atomic absorption method

    SciTech Connect

    Bel'skii, N.K.; Ochertyanova L.I.; Zhegalinka, V.A.

    1986-07-01

    By the atomic absorption method one measures the light absorption by the vapor of the investigated element as a function of the temperature of the evaporating surface. To measure vapor pressure the authors use cadmium selenide of the purity grade, which was recrystallized by sublimitation. The optical density of the vapor over cadmium selenide was determined in the temperature range 820-890 K. Using atomic spectroscopy the vapor pressure of cadmium over cadmium selenide was determined in dichromium cadmium tetraselenide with different amounts of deviation from stoichiometry at 790-880 deg. The results are compared with the literature data.

  20. Methods for analysis of selected metals in water by atomic absorption

    USGS Publications Warehouse

    Fishman, Marvin J.; Downs, Sanford C.

    1966-01-01

    This manual describes atomic-absorption-spectroscopy methods for determining calcium, copper, lithium, magnesium, manganese, potassium, sodium, strontium and zinc in atmospheric precipitation, fresh waters, and brines. The procedures are intended to be used by water quality laboratories of the Water Resources Division of the U.S. Geological Survey. Detailed procedures, calculations, and methods for the preparation of reagents are given for each element along with data on accuracy, precision, and sensitivity. Other topics discussed briefly are the principle of atomic absorption, instrumentation used, and special analytical techniques.

  1. Fractionation and speciation of Cu, Zn and Fe in wine samples by atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Karadjova, Irina; Izgi, Belgin; Gucer, Seref

    2002-03-01

    A scheme is presented for fractionation of wine components and Fe, Cu and Zn determination in different fractions. The charge of the metal species was established using cation and anion exchange separation based on solid phase extraction. The resin XAD-8 was used for the separation of wine polyphenols in complexes with wine proteins and polysaccharides. Dowex ion exchange resins were used for the separation of cationic and anionic species of Fe, Cu and Zn. Flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry were used off-line for the quantitative determination of metals in the different fractions obtained.

  2. Comparison of liposome entrapment parameters by optical and atomic absorption spectrophotometry.

    PubMed

    Yoss, N L; Popescu, O; Pop, V I; Porutiu, D; Kummerow, F A; Benga, G

    1985-01-01

    Methods for the complete characterization of liposomes prepared by ether-injection are described in detail. The validity of atomic absorption spectrophotometry for measuring markers of trapped volume was checked by comparative determinations of markers with established optical spectrophotometrical methods. The favorable results using atomic absorption spectrophotometry to quantitate the marker Mn2+ are of particular relevance as manganese ion is also the paramagnetic probe in n.m.r. measurements of water permeability of liposomes; our results indicate that in such measurements no other marker need be incorporated.

  3. Investigations on Freon-assisted atomization of refractory analytes (Cr, Mo, Ti, V) in multielement electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Heinrich, Hans-Joachim; Matschat, Ralf

    2007-08-01

    Premixed 1% Freon in argon inner gas of various composition (CCl 2F 2, CHClF 2, CHF 3) was applied to graphite furnace atomizer to minimize unfavorable effects of carbide formation, such as signal tailing and memory effects in the simultaneous determination of Cr, Mo, Ti and V refractory analytes by electrothermal atomic absorption spectrometry using a multielement atomic absorption spectrometer. The effect of these gaseous additives was investigated when applied separately in atomization, pyrolysis and clean-out steps. The halogenation effects were analytically useful only under the precondition of using Ar-H 2 outer gas to the furnace to all heating steps, and also using this gas in the pre-atomization (drying, pyrolysis) steps. Optimum analytical performance was obtained when mixtures of 1% Freon in argon were applied just before and during the atomization step at a flow rate of 50 mL min - 1 and 2% hydrogen was used as purge gas. Using optimum conditions, signal tailings and carry-over contamination were reduced effectively and good precision (relative standard deviation below 1%) could be attained. Applying 1% CHClF 2 and an atomization temperature of 2550 °C, the characteristic masses obtained for simple aqueous solutions were 8.8 pg for Cr, 17 pg for Mo, 160 pg for Ti, and 74 pg for V. The limits of detection were 0.05, 0.2, 2.3 and 0.5 μg L - 1 for Cr, Mo, Ti and V, respectively. The developed method was applied to the analysis of digests of advanced ceramics. The accuracy of the procedure was confirmed by analyzing the certified reference material ERM-ED 102 (Boron Carbide Powder) and a silicon nitride powder distributed in the inter-laboratory comparison CCQM-P74.

  4. Temporal and spatial temperature distributions in transversely heated graphite tube atomizers and their analytical characteristics for atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Sperling, Michael; Welz, Bernard; Hertzberg, Joachim; Rieck, Christof; Marowsky, Gerd

    1996-07-01

    The important role which temperature plays in atomic absorption spectrometry (AAS) for the formation and detection of atoms in the absorption volume is discussed and the literature is reviewed. Non-homogeneous temperature distribution in the absorption volume is in contradiction to one of the prerequisites for the application of Beer's law used in AAS to convert absorbance into analyte concentration or mass, and is particularly troublesome for an "absolute analysis" envisaged for electrothermal atomic absorption spectrometry (ETAAS). Coherent anti-Stokes Raman scattering (CARS) is used to study the gas-phase temperature distribution in a state-of-the-art transversely heated graphite tube atomizer (THGA). The effect of the internal gas flow on the size of the heated atmosphere is studied by steady-state temperature measurements. Temporally and spatially resolved measurements make it possible to study the temperature field within the atomizer volume in all three dimensions during the rapid heating of the furnace to final temperatures in the range 2173-2673 K. The role of the integrated platform of the THGA on the temperature field is investigated by temperature measurements of the gas phase in the presence and absence of the platform. The platform is identified as the major source of temperature gradients inside the tube volume, which may be as high as 1000 K in the radial direction during rapid heating. These gradients are most pronounced for heating cycles starting at room temperature and gradually decrease with increasing starting temperature. Shortly after the tube wall reaches its final temperature, the gas-phase temperature equilibrates and approaches the wall temperature. Because of the unavoidable contact with the cold environment at the open ends of the tube, minor temperature gradients are observed in the gas phase also in longitudinal direction, which can be further reduced by restricting the openings with end caps. The results obtained for the THGA are

  5. Microwave absorption properties of carbon nanocoils coated with highly controlled magnetic materials by atomic layer deposition.

    PubMed

    Wang, Guizhen; Gao, Zhe; Tang, Shiwei; Chen, Chaoqiu; Duan, Feifei; Zhao, Shichao; Lin, Shiwei; Feng, Yuhong; Zhou, Lei; Qin, Yong

    2012-12-21

    In this work, atomic layer deposition is applied to coat carbon nanocoils with magnetic Fe(3)O(4) or Ni. The coatings have a uniform and highly controlled thickness. The coated nanocoils with coaxial multilayer nanostructures exhibit remarkably improved microwave absorption properties compared to the pristine carbon nanocoils. The enhanced absorption ability arises from the efficient complementarity between complex permittivity and permeability, chiral morphology, and multilayer structure of the products. This method can be extended to exploit other composite materials benefiting from its convenient control of the impedance matching and combination of dielectric-magnetic multiple loss mechanisms for microwave absorption applications.

  6. The extreme wings of atomic emission and absorption lines. [in low pressure gases

    NASA Technical Reports Server (NTRS)

    Dalgarno, A.; Sando, K. M.

    1973-01-01

    Consideration of the extreme wings of atomic and molecular emission and absorption lines in low pressure gases. Classical and semiclassical results are compared with accurate quantal calculations of the self-broadening of Lyman-alpha in the hydrogen absorption spectrum that arises from quasimolecular transition. The results of classical, quantal, and semiclassical calculations of the absorption coefficient in the red wing are shown for temperatures of 500, 200, and 100 K. The semiclassical and quantal spectra agree well in shape at 500 K. Various other findings are discused.

  7. Determination of sub microgram amounts of selenium in rocks by atomic-absorption spectroscopy.

    PubMed

    Golembeski, T

    1975-06-01

    Atomic-absorption spectroscopy was used to determine trace amounts of selenium accurately in U.S. Geological Survey standard rocks, GSP-1, W-1 and BCR-1. The results obtained were compared with those obtained by neutron-activation analysis and excellent agreement was found; in addition, the selenium:sulphur ratio was calculated and agreed with results obtained by other workers.

  8. Circuit Board Analysis for Lead by Atomic Absorption Spectroscopy in a Course for Nonscience Majors

    ERIC Educational Resources Information Center

    Weidenhammer, Jeffrey D.

    2007-01-01

    A circuit board analysis of the atomic absorption spectroscopy, which is used to measure lead content in a course for nonscience majors, is being presented. The experiment can also be used to explain the potential environmental hazards of unsafe disposal of various used electronic equipments.

  9. COMPREHENSIVE ANALYSIS OF BIOLOGICALLY RELEVANT ARSENICALS BY PH-SELECTIVE HYDRIDE GENERATION-ATOMIC ABSORPTION SPECTROMETRY

    EPA Science Inventory


    A method based on pH-selective generation and separation of arsines is commonly used for analysis of inorganic, methylated, and dimethylated trivalent and pentavalent arsenicals by hydride generation-atomic absorption spectrometry (HG-AAS). We have optimized this method to pe...

  10. DETERMINING BERYLLIUM IN DRINKING WATER BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROSCOPY

    EPA Science Inventory

    A direct graphite furnace atomic absorption spectroscopy method for the analysis of beryllium in drinking water has been derived from a method for determining beryllium in urine. Ammonium phosphomolybdate and ascorbic acid were employed as matrix modifiers. The matrix modifiers s...

  11. DETERMINING BERYLLIUM IN DRINKING WATER BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROSCOPY

    EPA Science Inventory

    A direct graphite furnace atomic absorption spectroscopy method for the analysis of beryllium in drinking water has been derived from a method for determining beryllium in urine. Ammonium phosphomolybdate and ascorbic acid were employed as matrix modifiers. The matrix modifiers s...

  12. Determination of platinum, palladium, and lead in biological samples by atomic absorption spectrophotometry.

    PubMed Central

    Tillery, J B; Johnson, D E

    1975-01-01

    A flameless atomic absorption method for the coextraction of platinum and palladium from biological and environmental samples by high molecular weight amine (HMWA) is given. Also, methods for lead determination in biological samples by use of extraction flameless analysis and direct aspiration-flame analysis are reported. A study of lead contamination of Vacutainer tubes is given. PMID:1227857

  13. Circuit Board Analysis for Lead by Atomic Absorption Spectroscopy in a Course for Nonscience Majors

    ERIC Educational Resources Information Center

    Weidenhammer, Jeffrey D.

    2007-01-01

    A circuit board analysis of the atomic absorption spectroscopy, which is used to measure lead content in a course for nonscience majors, is being presented. The experiment can also be used to explain the potential environmental hazards of unsafe disposal of various used electronic equipments.

  14. The Use of an Air-Natural Gas Flame in Atomic Absorption.

    ERIC Educational Resources Information Center

    Melucci, Robert C.

    1983-01-01

    Points out that excellent results are obtained using an air-natural gas flame in atomic absorption experiments rather than using an air-acetylene flame. Good results are obtained for alkali metals, copper, cadmium, and zinc but not for the alkaline earths since they form refractory oxides. (Author/JN)

  15. The Use of an Air-Natural Gas Flame in Atomic Absorption.

    ERIC Educational Resources Information Center

    Melucci, Robert C.

    1983-01-01

    Points out that excellent results are obtained using an air-natural gas flame in atomic absorption experiments rather than using an air-acetylene flame. Good results are obtained for alkali metals, copper, cadmium, and zinc but not for the alkaline earths since they form refractory oxides. (Author/JN)

  16. Determination of arsenic and selenium in environmental and agricultural samples by hydride generation atomic absorption spectrometry

    SciTech Connect

    Hershey, J.W.; Oostdyk, T.S.; Keliher, P.N.

    1988-11-01

    Agricultural and environmental samples are digested with acid, and arsenic and selenium are determined using hydride generation atomic absorption spectrometry. Interelement interferences are eliminated by high acid concentrations or cation-exchange resins. Agreement with standard reference material is excellent. The technique is also applied to actual samples.

  17. Application of indirect methods in analysis by atomic-absorption spectrometry.

    PubMed

    Kirkbright, G F; Johnson, H N

    1973-05-01

    The use of indirect methods for the determination by atomic-absorption spectrometry of those elements not normally amenable to sensitive determination by this technique is reviewed. The available indirect methods are classified into five general types of procedure; specific reported procedures for the determination of metals, non-metals and some compounds are discussed.

  18. COMPREHENSIVE ANALYSIS OF BIOLOGICALLY RELEVANT ARSENICALS BY PH-SELECTIVE HYDRIDE GENERATION-ATOMIC ABSORPTION SPECTROMETRY

    EPA Science Inventory


    A method based on pH-selective generation and separation of arsines is commonly used for analysis of inorganic, methylated, and dimethylated trivalent and pentavalent arsenicals by hydride generation-atomic absorption spectrometry (HG-AAS). We have optimized this method to pe...

  19. CONCENTRATIONS OF AU ATOMS IN HOLLOW-CATHODE DISCHARGE BY RESONANCE-LINE ABSORPTION.

    DTIC Science & Technology

    The determination of the concentration of sputtered gold atoms in a hollow -cathode discharge at approximately 450 mtorr of argon was made by...measuring the absorption of the two resonance lines, 2428 and 2676A, of a gold hollow -cathode source. The following points are considered: effect of

  20. Direct Electrothermal Atomic Absorption Determination of Trace Elements in Body Fluids (Review)

    NASA Astrophysics Data System (ADS)

    Zacharia, A. N.; Arabadji, M. V.; Chebotarev, A. N.

    2017-03-01

    This review is focused on the state and development of tendencies of electrothermal atomic absorption spectroscopy over the last 25 years (from 1990 to 2016) in the direct determination of Cu, Zn, Pb, Cd, Mn, Se, As, Cr, Co, Ni, Al, and Hg in body fluids such as blood, urine, saliva, and breast milk.

  1. Point defect absorption by grain boundaries in α -iron by atomic density function modeling

    NASA Astrophysics Data System (ADS)

    Kapikranian, O.; Zapolsky, H.; Patte, R.; Pareige, C.; Radiguet, B.; Pareige, P.

    2015-12-01

    Using the atomic density function theory (ADFT), we examine the point defect absorption at [110] symmetrical tilt grain boundaries in body-centered cubic iron. It is found that the sink strength strongly depends on misorientation angle. We also show that the ADFT is able to reproduce reasonably well the elastic properties and the point defect formation volume in α -iron.

  2. Optical pumping effect in absorption imaging of F =1 atomic gases

    NASA Astrophysics Data System (ADS)

    Kim, Sooshin; Seo, Sang Won; Noh, Heung-Ryoul; Shin, Y.

    2016-08-01

    We report our study of the optical pumping effect in absorption imaging of 23Na atoms in the F =1 hyperfine spin states. Solving a set of rate equations for the spin populations in the presence of a probe beam, we obtain an analytic expression for the optical signal of the F =1 absorption imaging. Furthermore, we verify the result by measuring the absorption spectra of 23Na Bose-Einstein condensates prepared in various spin states with different probe-beam pulse durations. The analytic result can be used in the quantitative analysis of F =1 spinor condensate imaging and readily applied to other alkali-metal atoms with I =3 /2 nuclear spin such as 87Rb.

  3. Enhanced Reverse Saturable Absorption and Optical Limiting in Heavy-Atom Substituted Phthalocyanines

    NASA Technical Reports Server (NTRS)

    Perry, J. W.; Mansour, K.; Marder, S. R.; Alvarez, D., Jr.; Perry, K. J.; Choong, I.

    1994-01-01

    The reverse saturable absorption and optical limiting response of metal phthalocyaninies can be enhanced by using the heavy-atom effect. Phthalocyanines containing heavy metal atoms, such as In, Sn, and Pb show nearly a factor of two enhancement in the ratio of effective excited-state to ground-state absorption cross sections compared to those containing lighter atoms, such as Al and Si. In an f/8 optical geometry, homogeneous solutions of heavy metal phthalocyanines, at 30% linear transmission, limit 8-ns, 532-nm laser pulses to less than or equal to 3 (micro)J (the energy for 50% probability of eye damage) for incident pulses up to 800 (micro)J.

  4. Enhanced Reverse Saturable Absorption and Optical Limiting in Heavy-Atom Substituted Phthalocyanines

    NASA Technical Reports Server (NTRS)

    Perry, J. W.; Mansour, K.; Marder, S. R.; Alvarez, D., Jr.; Perry, K. J.; Choong, I.

    1994-01-01

    The reverse saturable absorption and optical limiting response of metal phthalocyaninies can be enhanced by using the heavy-atom effect. Phthalocyanines containing heavy metal atoms, such as In, Sn, and Pb show nearly a factor of two enhancement in the ratio of effective excited-state to ground-state absorption cross sections compared to those containing lighter atoms, such as Al and Si. In an f/8 optical geometry, homogeneous solutions of heavy metal phthalocyanines, at 30% linear transmission, limit 8-ns, 532-nm laser pulses to less than or equal to 3 (micro)J (the energy for 50% probability of eye damage) for incident pulses up to 800 (micro)J.

  5. [Determination of sulfur in plant using a high-resolution continuum source atomic absorption spectrometer].

    PubMed

    Wang, Yu; Li, Jia-xi

    2009-05-01

    A method for the analysis of sulfur (S) in plant by molecular absorption of carbon monosulfide (CS) using a high-resolution continuum source atomic absorption spectrometer (CS AAS) with a fuel-rich air/acetylene flame has been devised. The strong CS absorption band was found around 258 nm. The half-widths of some absorption bands were of the order of picometers, the same as the common atomic absorption lines. The experimental procedure in this study provided optimized instrumental conditions (the ratio of acetylene to air, the burner height) and parameters, and researched the spectral interferences and chemical interferences. The influence of the organic solvents on the CS absorption signals and the different digestion procedures for the determination of sulfur were also investigated. The limit of detection achieved for sulfur was 14 mg x L(-1), using the CS wavelength of 257. 961 nm and a measurement time of 3 s. The accuracy and precision were verified by analysis of two plant standard reference materials. The major applications of this method have been used for the determination of sulfur in plant materials, such as leaves. Compared to the others, this method for the analysis of sulfur is rapid, easy and simple for sulfur determination in plant.

  6. Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course

    ERIC Educational Resources Information Center

    Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey

    2004-01-01

    An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of…

  7. Determination of Calcium in Cereal with Flame Atomic Absorption Spectroscopy: An Experiment for a Quantitative Methods of Analysis Course

    ERIC Educational Resources Information Center

    Bazzi, Ali; Kreuz, Bette; Fischer, Jeffrey

    2004-01-01

    An experiment for determination of calcium in cereal using two-increment standard addition method in conjunction with flame atomic absorption spectroscopy (FAAS) is demonstrated. The experiment is intended to introduce students to the principles of atomic absorption spectroscopy giving them hands on experience using quantitative methods of…

  8. Determination of cadmium and lead in urine by derivative flame atomic absorption spectrometry using the atom trapping technique

    NASA Astrophysics Data System (ADS)

    Han-wen, Sun; De-qiang, Zhang; Li-li, Yang; Jian-min, Sun

    1997-06-01

    A method is described for the determinations of cadmium and lead in urine by derivative flame atomic absorption spectrometry with a modified water-cooled stainless steel atom trapping tube. The effects of the trap position, the flame conditions, the coolant flow rates, and the collection time were studied. With a 1 min collection time, the characteristic concentrations (derivative absorbance of 0.0044) for cadmium and lead were 0.028 and 1.4 μg L -1, the detection limits (3σ) were 0.02 and 0.27 μg L -1, respectively. The detection limits and sensitivities of the proposed method were 2 and 3 orders of magnitude higher for 1-3 min collection time than those of conventional flame atomic absorption spectrometry for cadmium and lead, respectively. Urine samples from a small population of normal individuals have been analyzed for cadmium and lead by the proposed method. Satisfactory recoveries of 91-110% and 91-106%, for Cd and Pb were obtained with these urine samples.

  9. Analytical control of wollastonite for biomedical applications by use of atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry.

    PubMed

    De Aza, P N; Guitián, F; De Aza, S; Valle, F J

    1998-04-01

    Preliminary in vitro experiments revealed that wollastonite (CaSiO3) is a potentially highly bioactive material that forms a hyroxyapatite (HA) surface layer on exposure to simulated body fluid with an ion concentration, pH and temperature virtually identical with those of human blood plasma. The formation of the HA layer is an essential requirement for an artificial material to be used as bioactive bone substitute. This finding opens up a wide field for biomedical applications of wollastonite. Biomaterials used as implants in the human body require strict control of trace elements and of the toxic species specified in American Society for Testing and Materials F-1185-88 (As, Cd, Hg and Pb) in ceramic hydroxyapatite for surgical implantation. In this work, two types of pseudowollastonite, the high temperature form of wollastonite, were analysed by using cold vapour atomic absorption spectrometry and hydride generation atomic absorption spectrometry, in order to determine the elements stated in the above-mentioned norm, and inductively coupled plasma atomic emission spectrometry to establish the SiO2/CaO ratio of the two materials and analyse for all other impurities introduced by the raw materials and by the processes of synthesis, sintering and grinding. Barium and Mg were especially prominent in raw materials, and Zr, Y, Mg, W, Co and Ni come mainly from the processing.

  10. Tunable Diode Laser Atomic Absorption Spectroscopy for Detection of Potassium under Optically Thick Conditions.

    PubMed

    Qu, Zhechao; Steinvall, Erik; Ghorbani, Ramin; Schmidt, Florian M

    2016-04-05

    Potassium (K) is an important element related to ash and fine-particle formation in biomass combustion processes. In situ measurements of gaseous atomic potassium, K(g), using robust optical absorption techniques can provide valuable insight into the K chemistry. However, for typical parts per billion K(g) concentrations in biomass flames and reactor gases, the product of atomic line strength and absorption path length can give rise to such high absorbance that the sample becomes opaque around the transition line center. We present a tunable diode laser atomic absorption spectroscopy (TDLAAS) methodology that enables accurate, calibration-free species quantification even under optically thick conditions, given that Beer-Lambert's law is valid. Analyte concentration and collisional line shape broadening are simultaneously determined by a least-squares fit of simulated to measured absorption profiles. Method validation measurements of K(g) concentrations in saturated potassium hydroxide vapor in the temperature range 950-1200 K showed excellent agreement with equilibrium calculations, and a dynamic range from 40 pptv cm to 40 ppmv cm. The applicability of the compact TDLAAS sensor is demonstrated by real-time detection of K(g) concentrations close to biomass pellets during atmospheric combustion in a laboratory reactor.

  11. Absorption spectrum of atomic impurities in isotopic mixtures of liquid helium

    NASA Astrophysics Data System (ADS)

    Mateo, David; Hernando, Alberto; Barranco, Manuel; Mayol, Ricardo; Pi, Martí

    2011-05-01

    We theoretically describe the absorption spectrum of atomic impurities in isotopic mixtures of liquid helium within a zero-temperature density functional approach. Two situations are considered. In the first one, the absorption spectrum of Na atoms attached to He41000-He3N3 droplets with N3 values from 100 to 3000 is presented as a case study of an impurity that does not dissolve into helium droplets. In the second one, the absorption spectrum of Mg atoms in liquid He3-He4 mixtures is presented as a case study of an impurity dissolved into liquid helium. We have found that the absorption spectrum of the impurity is rather insensitive to the isotopic composition because the line shift is mostly affected by the total He density around the impurity, not by its actual composition. For bulk liquid mixtures, results are presented as a function of pressure at selected values of the He3 concentration. The results for isotopically pure He3 and He4 liquids doped with Mg are compared with available experimental data.

  12. Electrothermal atomic-absorption determination of silver in zinc and cadmium selenides

    SciTech Connect

    Khozhainov, Yu.M.; Dolova, N.K.

    1987-10-01

    An atomic-absorption signal is dependent on the chemical forms of the test element and matrix in the solution as well as on the processes during electrothermal atomization. The authors have examined the absorption due to silver with a Saturn-2 spectrophotometer with such atomization; the authors used the 328.1 nm line (i = 10 mA, slit width 0.15, time-constant 0.6 sec). The presence of cadmium and zinc was monitored from the 326.1 and 213.8 nm lines respectively. The measurements were made in argon. The internal gas flow was turned off during the atomization. The graphite was used until there were sharp changes in the silver absorption due to change in the structure of the graphite and occurrence of the memory effect. The results from over 100 specimens of cadmium selenide films analyzed for silver showed that the results were in full agreement with the conditions for silver activation (time, temperature, and activator mass).

  13. Absorption of copper(II) by creosote bush (Larrea tridentata): use of atomic and x-ray absorption spectroscopy.

    PubMed

    Gardea-Torresdey, J L; Arteaga, S; Tiemann, K J; Chianelli, R; Pingitore, N; Mackay, W

    2001-11-01

    Larrea tridentata (creosote bush), a common North American native desert shrub, exhibits the ability to take up copper(II) ions rapidly from solution. Following hydroponic studies, U.S. Environmental Protection Agency method 200.3 was used to digest the plant samples, and flame atomic absorption spectroscopy (FAAS) was used to determine the amount of copper taken up in different parts of the plant. The amount of copper(II) found within the roots, stems, and leaves was 13.8, 1.1, and 0.6 mg/g, respectively, after the creosote bush was exposed to a 63.5-ppm copper(II) solution for 48 h. When the plant was exposed to a 635-ppm copper(II) solution, the roots, stems, and leaves contained 35.0, 10.5, and 3.8 mg/g, respectively. In addition to FAAS analysis, x-ray microfluorescence (XRMF) analysis of the plant samples provided further confirmation of copper absorption by the various plant parts. X-ray absorption spectroscopy (XAS) elucidated the oxidation state of the copper absorbed by the plants. The copper(II) absorbed from solution remained as copper(II) bound to oxygen-containing ligands within the plant samples. The results of this study indicate that creosote bush may provide a useful and novel method of removing copper(II) from contaminated soils in an environmentally friendly manner.

  14. Determination of Cd in urine by cloud point extraction-tungsten coil atomic absorption spectrometry.

    PubMed

    Donati, George L; Pharr, Kathryn E; Calloway, Clifton P; Nóbrega, Joaquim A; Jones, Bradley T

    2008-09-15

    Cadmium concentrations in human urine are typically at or below the 1 microgL(-1) level, so only a handful of techniques may be appropriate for this application. These include sophisticated methods such as graphite furnace atomic absorption spectrometry and inductively coupled plasma mass spectrometry. While tungsten coil atomic absorption spectrometry is a simpler and less expensive technique, its practical detection limits often prohibit the detection of Cd in normal urine samples. In addition, the nature of the urine matrix often necessitates accurate background correction techniques, which would add expense and complexity to the tungsten coil instrument. This manuscript describes a cloud point extraction method that reduces matrix interference while preconcentrating Cd by a factor of 15. Ammonium pyrrolidinedithiocarbamate and Triton X-114 are used as complexing agent and surfactant, respectively, in the extraction procedure. Triton X-114 forms an extractant coacervate surfactant-rich phase that is denser than water, so the aqueous supernatant is easily removed leaving the metal-containing surfactant layer intact. A 25 microL aliquot of this preconcentrated sample is placed directly onto the tungsten coil for analysis. The cloud point extraction procedure allows for simple background correction based either on the measurement of absorption at a nearby wavelength, or measurement of absorption at a time in the atomization step immediately prior to the onset of the Cd signal. Seven human urine samples are analyzed by this technique and the results are compared to those found by the inductively coupled plasma mass spectrometry analysis of the same samples performed at a different institution. The limit of detection for Cd in urine is 5 ngL(-1) for cloud point extraction tungsten coil atomic absorption spectrometry. The accuracy of the method is determined with a standard reference material (toxic metals in freeze-dried urine) and the determined values agree with

  15. Self-corrected sensors based on atomic absorption spectroscopy for atom flux measurements in molecular beam epitaxy

    NASA Astrophysics Data System (ADS)

    Du, Y.; Droubay, T. C.; Liyu, A. V.; Li, G.; Chambers, S. A.

    2014-04-01

    A high sensitivity atom flux sensor based on atomic absorption spectroscopy has been designed and implemented to control electron beam evaporators and effusion cells in a molecular beam epitaxy system. Using a high-resolution spectrometer and a two-dimensional charge coupled device detector in a double-beam configuration, we employ either a non-resonant line or a resonant line with low cross section from the same hollow cathode lamp as the reference for nearly perfect background correction and baseline drift removal. This setup also significantly shortens the warm-up time needed compared to other sensor technologies and drastically reduces the noise coming from the surrounding environment. In addition, the high-resolution spectrometer allows the most sensitive resonant line to be isolated and used to provide excellent signal-to-noise ratio.

  16. Self-corrected sensors based on atomic absorption spectroscopy for atom flux measurements in molecular beam epitaxy

    SciTech Connect

    Du, Y. E-mail: scott.chambers@pnnl.gov; Liyu, A. V.; Droubay, T. C.; Chambers, S. A. E-mail: scott.chambers@pnnl.gov; Li, G.

    2014-04-21

    A high sensitivity atom flux sensor based on atomic absorption spectroscopy has been designed and implemented to control electron beam evaporators and effusion cells in a molecular beam epitaxy system. Using a high-resolution spectrometer and a two-dimensional charge coupled device detector in a double-beam configuration, we employ either a non-resonant line or a resonant line with low cross section from the same hollow cathode lamp as the reference for nearly perfect background correction and baseline drift removal. This setup also significantly shortens the warm-up time needed compared to other sensor technologies and drastically reduces the noise coming from the surrounding environment. In addition, the high-resolution spectrometer allows the most sensitive resonant line to be isolated and used to provide excellent signal-to-noise ratio.

  17. A new atomic absorption spectral assay for the determination of trace IgG using immunonanogold.

    PubMed

    Tang, Yafang; Jiang, Caina; Liang, Aihui; Li, Jishun; Jiang, Zhiliang

    2011-05-01

    Nanogold in size of 10 nm was used to label goat anti-human IgG (GIgG) to obtain an immunonanogold probe (AuGIgG) for IgG. In pH 6.8 phosphate buffer solution and in the presence of immunoprecipitator polyethylene glycol 6000 (PEG 6000), IgG reacted with the probe (AuGIgG) to form AuGIgG-IgG-PEG immunocomplex. After the centrifugation to remove the immunocomplex, AuGIgG in the supernatant can be measured by atomic absorption spectrophotometry at gold absorption line 242.8 nm. The results showed that the absorption value decreased as the concentration of IgG increased, and the decreased absorption value was linear to IgG concentration in the range 0.025-0.375 μg/mL, with a detection limit of 0.008 μg/mL. On this base, a new nanogold-labeled atomic absorption spectral assay for IgG was established. The assay was applied to determine IgG in human serum sample with satisfactory results.

  18. Electrothermal atomization atomic absorption spectrometry for the determination of lead in urine: results of an interlaboratory study

    NASA Astrophysics Data System (ADS)

    Parsons, Patrick J.; Slavin, Walter

    1999-05-01

    Results of an interlaboratory study are reported for the determination of lead in urine. Two levels of a lyophilized material containing biologically-bound lead were prepared using pooled urine obtained from lead-poisoned children undergoing the CaNa 2EDTA mobilization test. The materials were circulated to a group of reference laboratories that participate in the `New York State Proficiency Testing Program for Blood Lead'. Results of the initial round-robin gave all-method consensus target values of 145±22 μg/l (S.D.) for lot 17 and 449±43 μg/l (S.D.) for lot 20. The interlaboratory exercise was repeated some 5 years later and consensus target values were re-calculated using the grand mean (excluding outliers) of results reported by laboratories using electrothermal atomization atomic absorption spectrometry (ETAAS). The re-calculated target values were 139±10 μg/l (S.D.) and 433±12 μg/l (S.D.). The urine reference materials were also analyzed for lead by several laboratories using other instrumental techniques including isotope dilution (ID), inductively coupled plasma (ICP) mass spectrometry (MS), flame atomic absorption with extraction, ICP-atomic emission spectrometry, ID-gas chromatography MS and flow injection-hydride generation AAS, thus providing a rich source of analytical data with which to characterize them. The materials were also used in a long-term validation study of an ETAAS method developed originally for blood lead determinations that has since been used unmodified for the determination of lead in urine also. Recently, urine lead method performance has been tracked in a proficiency testing program specifically for this analysis. In addition, a number of commercial control materials have been analyzed and evaluated.

  19. Determination of zinc in serum, blood, and ultrafiltrate fluid from patients on hemofiltration by graphite furnace/atomic absorption spectroscopy or flow injection analysis/atomic absorption spectroscopy.

    PubMed

    de Blas, O J; Rodriguez, R S; Mendez, J H; Tomero, J A; Gomez, B de L; Gonzalez, S V

    1994-01-01

    Two methods were optimized for the determination of zinc in samples of blood, serum, and ultrafiltrate fluid from patients with chronic renal impairment undergoing hemofiltration. In the first procedure, after acid digestion of the samples, Zn in blood and serum is determined by a system coupled to flow injection analysis and atomic absorption spectroscopy. The method is rapid, automated, simple, needs small amounts of sample, and has acceptable analytical characteristics. The analytical characteristics obtained were as follows: determination range of method, 0.05-2.0 ppm of Zn; precision as coefficient of variation (CV), 5.3%; recovery, 95-105%; and detection limit (DL), 0.02 ppm. The second method is optimized for ultrafiltrate fluid because the sensitivity of the first procedure is not suitable for the levels of Zn (ppb or ng/mL) in these samples. The technique chosen was atomic absorption spectroscopy with electrothermal atomization in a graphite furnace. The analytical characteristics obtained were as follows: determination range of method, 0.3-2.0 ppb Zn; CV, 5.7%; recovery, 93-107%; and DL, 0.12 ppb. The methods were used to determine zinc in samples of blood, serum, and ultrafiltrate fluid from 5 patients with chronic renal impairment undergoing hemofiltration to discover whether there were significant differences in the zinc contents of blood, serum, and ultrafiltrate fluid after the hemofiltration process. An analysis of variance of the experimental data obtained from a randomly selected group of 5 patients showed that zinc concentrations in the ultrafiltrate fluid, venous blood, and venous serum do not vary during hemofiltration (p < 0.05), whereas in arterial blood and serum, the time factor has a significant effect.

  20. Comparison of two absorption imaging methods to detect cold atoms in magnetic trap

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Hu, Zhao-Hui; Qi, Lu

    2015-02-01

    Two methods of absorption imaging to detect cold atoms in a magnetic trap are implemented for a high-precision cold atom interferometer. In the first method, a probe laser which is in resonance with a cycle transition frequency is used to evaluate the quantity and distribution of the atom sample. In the second method, the probe laser is tuned to an open transition frequency, which stimulates a few and constant number of photons per atom. This method has a shorter interaction time and results in absorption images which are not affected by the magnetic field and the light field. We make a comparison of performance between these two imaging methods in the sense of parameters such as pulse duration, light intensity, and magnetic field strength. The experimental results show that the second method is more reliable when detecting the quantity and density profiles of the atoms. These results fit well to the theoretical analysis. Project supported by the National Natural Science Foundation of China (Grant Nos. 61227902 and 61121003) and the National Defense Basic Scientific Research Program of China (Grant No. B2120132005).

  1. Solid sampling determination of magnesium in lithium niobate crystals by graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Dravecz, Gabriella; Laczai, Nikoletta; Hajdara, Ivett; Bencs, László

    2016-12-01

    The vaporization/atomization processes of Mg in high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS) were investigated by evaporating solid (powder) samples of lithium niobate (LiNbO3) optical single crystals doped with various amounts of Mg in a transversally heated graphite atomizer (THGA). Optimal analytical conditions were attained by using the Mg I 215.4353 nm secondary spectral line. An optimal pyrolysis temperature of 1500 °C was found for Mg, while the compromise atomization temperature in THGAs (2400 °C) was applied for analyte vaporization. The calibration was performed against solid (powered) lithium niobate crystal standards. The standards were prepared with exactly known Mg content via solid state fusion of the oxide components of the matrix and analyte. The correlation coefficient (R value) of the linear calibration was not worse than 0.9992. The calibration curves were linear in the dopant concentration range of interest (0.74-7.25 mg/g Mg), when dosing 3-10 mg of the powder samples into the graphite sample insertion boats. The Mg content of the studied 19 samples was in the range of 1.69-4.13 mg/g. The precision of the method was better than 6.3%. The accuracy of the results was verified by means of flame atomic absorption spectrometry with solution sample introduction after digestion of several crystal samples.

  2. An improved electrothermal atomic absorption spectroscopy method for the determination of lithium in molybdenum oxide using slurry sampling and a tungsten atomizer

    NASA Astrophysics Data System (ADS)

    Dočekal, Bohumil; Krivan, Viliam

    1993-11-01

    A transversely heated tungsten-tube atomizer, WETA 82, was used for the direct determination of lithium in ultra-high purity molybdenum trioxide by slurry sampling electrothermal atomic absorption spectrometry. Optimized conditions with regard to sample preparation, temperature program, possible spectral interferences and depressive effects of sample matrix were presented. Analytical performance of the conventional graphite atomizer and the tungsten atomizer were compared. Using the WETA 82 atomizer, a detection limit for lithium of 2 ng g -1 can be achieved, which is one order of magnitude lower than that for conventional graphite atomizers.

  3. [Determination of trace Rh in organic residue by flame atomic absorption spectrophotometry].

    PubMed

    Han, Mei; Cheng, Fang; Gu, Shi-fang; Cui, Li-jun; Xiao, Guang; Xu, Song-yun

    2003-02-01

    The catalytic organic residue contained Rh was digested with HNO3 at 130 degrees C for 12 h. Trace noble metal Rh in catalytic organic residue was determined by flame atomic absorption spectrophotometry. Rh was atomized by air-acetylene flame at lamp Current of 7 mA. The methods of sample pretreatment for Rh in residue were compared in this paper. The recovery rates of this method were 95.3%-105.5% and the relative standard derivation was 0.9%. The method was applied to the analysis of some practical samples and the results obtained were satisfactory.

  4. CASCADE CALCULATION OF EXOTIC HELIUM ATOMS -- s-orbit vs. p-orbit absorption rates

    NASA Astrophysics Data System (ADS)

    Koike, T.; Akaishi, Y.

    2000-09-01

    We construct a new model for the Stark-mixing process of exotic helium atoms using the impact-parameter method, and compared it with a phenomenological one used so far (sliding transition model). It turns out that the sliding transition model is justified only for low-n states and largely overestimates the Stark-mixing transition rate at high-n states. As a result of the atomic-cascade calculation, the s-(p-)orbit absorption rates in our new model are considerably smaller (larger) than those in the phenomenological one, although both our new model and old one well reproduce the experimental x-ray yields.

  5. Tunable Diode Laser Absorption Spectroscopy of Metastable Atoms in Dusty Plasmas

    SciTech Connect

    Hoang Tung Do; Hippler, Rainer

    2008-09-07

    Spatial density profile of neon metastable produced in dusty plasma was investigated by means of tunable diode laser absorption spectroscopy. The line averaged measured density drops about 30% with the presence of dust particles. The observations provide evidence for a significant interaction between atoms and powder particles which are important for energy transfer from plasma to particles. The power per unit area absorbed by dust particles due to the collision of metastable atoms with dust particle surface is about some tens of mW/m{sup 2}.

  6. Dual structure of saturated absorption resonance at an open atomic transition

    NASA Astrophysics Data System (ADS)

    Vasil'ev, V. V.; Velichanskii, V. L.; Zibrov, S. A.; Sivak, A. V.; Brazhnikov, D. V.; Taichenachev, A. V.; Yudin, V. I.

    2011-05-01

    Experiments on open transitions of the D 1 line of alkali metals (Cs and Rb isotopes) reveal the dual structure of saturated absorption resonance in the signal of a high-intensity optical wave in the presence of a low-intensity counterpropagating wave. Theoretical analysis shows that the observed shape of the resonance is associated with the openness of the atomic transition as well as with the Doppler effect for atoms in a gas. The results are of general physical significance for nonlinear spectroscopy and can also find application in metrology (frequency and time standards on open transitions).

  7. Dual structure of saturated absorption resonance at an open atomic transition

    SciTech Connect

    Vasil'ev, V. V. Velichanskii, V. L. Zibrov, S. A.; Sivak, A. V.; Brazhnikov, D. V. Taichenachev, A. V. Yudin, V. I.

    2011-05-15

    Experiments on open transitions of the D{sub 1} line of alkali metals (Cs and Rb isotopes) reveal the dual structure of saturated absorption resonance in the signal of a high-intensity optical wave in the presence of a low-intensity counterpropagating wave. Theoretical analysis shows that the observed shape of the resonance is associated with the openness of the atomic transition as well as with the Doppler effect for atoms in a gas. The results are of general physical significance for nonlinear spectroscopy and can also find application in metrology (frequency and time standards on open transitions).

  8. Measurements of sulfur compounds in CO 2 by diode laser atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Franzke, J.; Stancu, D. G.; Niemax, K.

    2003-07-01

    Two simple methods for the analysis of the total concentration of sulfur in CO 2 by diode laser atomic absorption spectrometry of excited, metastable sulfur atoms in a direct current discharge are presented. In the first method, the CO 2 sample gas is mixed with the plasma gas (Ar or He) while the second is based on reproducible measurements of the sulfur released from the walls in a helium discharge after being deposited as a result of operating the discharge in pure CO 2 sample gas. The detection limits obtained satisfy the requirements for the control of sulfur compounds in CO 2 used in the food and beverage industry.

  9. Three-photon-absorption resonance for all-optical atomic clocks

    SciTech Connect

    Zibrov, Sergei; Novikova, Irina; Phillips, David F.; Taichenachev, Aleksei V.; Yudin, Valeriy I.; Walsworth, Ronald L.; Zibrov, Alexander S.

    2005-07-15

    We report an experimental study of an all-optical three-photon-absorption resonance (known as an 'N resonance') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the N-resonance contrast, width and light shift for the D{sub 1} line of {sup 87}Rb with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that N resonances are promising for atomic clock applications.

  10. Temporal variations in gas temperature in an atomization stage of cadmium and tellurium evaluated by using the two-line method in graphite furnace atomic absorption spectrometry.

    PubMed

    Shimabukuro, Haruki; Ashino, Tetsuya; Wagatsuma, Kazuaki

    2008-09-01

    In order to discuss the atomization process of an analyte element occurring in a graphite furnace for atomic absorption spectrometry, we measured variations in the characteristic temperature with the progress of an atomization stage, by using a two-line method under the assumption of a Boltzmann distribution. For this purpose, iron was chosen as the analyte element. Also, the atomic absorption of two iron atomic lines, Fe I 372.0 nm and Fe I 373.7 nm, was simultaneously monitored as a probe for the temperature determination. This method enables variations in the gas temperature to be directly traced, yielding a temperature distribution closely related to the diffusion behavior of the probe element in the furnace. This temperature variation was very different from the furnace wall temperatures, which were monitored in conventional temperature control for atomic absorption spectrometry. Correlations between the gas temperature and the charring/atomizing temperatures in the heating program of the furnace were investigated. The atomization of cadmium and tellurium was also investigated by a comparison between the gas temperature with the wall temperature of the furnace. The atomic absorption of cadmium or tellurium appeared to be apart from the absorption of iron while the gas temperature was still low. Therefore, the analyte atoms could be atomized through direct contact with the wall of the graphite furnace, which has a much higher temperature compared to the gas atmosphere during atomization. Their atomization would be caused by conductive heating from the furnace wall rather than by radiant heating in the furnace.

  11. Determination of copper, zinc and iron in broncho-alveolar lavages by atomic absorption spectroscopy.

    PubMed

    Harlyk, C; Mccourt, J; Bordin, G; Rodriguez, A R; van der Eeckhout, A

    1997-11-01

    Concentrations of Zn, Cu and Fe were measured in 157 broncho-alveolar lavages (BAL), before and after centrifugation, collected at the Leuven University Hospital (Belgium). Zn was measured by flame-atomic absorption spectroscopy, using direct calibration, while Cu and Fe were determined by electrothermal atomic absorption spectroscopy, using the method of standard additions. For Fe only 56 samples were measured. Most of the studied elements are present in the liquid phase (supernatant). About 90% of Cu concentrations lie between 0 and 15 micrograms/kg, while 90% of Zn concentrations are lower than 230 micrograms/kg, with 30% between 30 and 70 micrograms/kg, and 50% between 100 and 200 micrograms/kg. There seems to be a reverse relationship between Cu and Zn levels with high Cu going along with low Zn and vice versa.

  12. [Determination of stannum in urine by graphite furnace atomic absorption spectrometry].

    PubMed

    Chen, Jiu; Wu, Shihua; Guo, Guanhao; Liu, Yimin

    2015-12-01

    To establish the method of graphite furnace atomic absorption spectrometry for the measurement of stannum in urine with calcium nitrate as the matrix modifier. Graphite tube was pretreated with calcium nitrate as the matrix modifier, the urine sample was diluted with 1% nitric acid and then direct injection was performed for these samples, and graphite furnace atomic absorption spectrometry was applied for measurement. The concentration of stannum in urine showed a good linear relationship within the range of 8.0~40.0 μg/L, with a correlation coefficient of 0.9981. The minimum detectable concentration was 0.72 μg/L, the degree of precision was 1.54%~6.69%, and the recovery rate was 99.23%~107.63%. This method can determine the content of stannum in urine accurately and rapidly, with a high sensitivity and a low cost.

  13. Determination of tetraalkyllead compounds in gasoline by liquid chromatography-atomic absorption spectrometry

    USGS Publications Warehouse

    Messman, J.D.; Rains, T.C.

    1981-01-01

    A liquid chromatography-atomic absorption spectrometry (LC-AAS) hybrid analytical technique is presented for metal speciation measurements on complex liquid samples. The versatility and inherent metal selectivity of the technique are Illustrated by the rapid determination of five tetraalkyllead compounds in commercial gasoline. Separation of the individual tetraalkyllead species is achieved by reversed-phase liquid chromatography using an acetonitrile/water mobile phase. The effluent from the liquid Chromatograph Is introduced directly into the aspiration uptake capillary of the nebulizer of an air/acetylene flame atomic absorption spectrometer. Spectral interferences due to coeluting hydrocarbon matrix constituents were not observed at the 283.3-nm resonance line of lead used for analysis. Detection limits of this LC-AAS hydrid analytical technique, based on a 20-??L injection, are approximately 10 ng Pb for each tetraalkyllead compound.

  14. Appropriate Probe Condition for Absorption Imaging of Ultracold 6Li Atoms

    NASA Astrophysics Data System (ADS)

    Horikoshi, Munekazu; Ito, Aki; Ikemachi, Takuya; Aratake, Yukihito; Kuwata-Gonokami, Makoto; Koashi, Masato

    2017-10-01

    One of the readily accessible observables in trapped cold-atom experiments is the column density, which is determined from the optical depth (OD) obtained from absorption imaging and the absorption cross section (σabs). Here, we report on a simple and accurate determination of OD for dense gases of light atoms such as lithium-6. We investigate theoretically and experimentally an appropriate condition for the probe intensity and duration to achieve a good signal-to-noise ratio by considering the effects of photon recoils and photon shot noises. As a result, we have succeeded in measuring OD, which reached 2.5 with a signal-to-noise ratio of 10 under a spatial resolution of 1.7 µm.

  15. Two-photon dichroic atomic vapor laser lock using electromagnetically induced transparency and absorption

    SciTech Connect

    Becerra, F. E.; Willis, R. T.; Rolston, S. L.; Orozco, L. A.

    2009-07-15

    We demonstrate a technique to lock the frequency of a laser to a transition between two excited states in Rb vapor using a two-photon process in the presence of a weak magnetic field. We use a ladder configuration from specific hyperfine sublevels of the 5S{sub 1/2}, 5P{sub 3/2}, and 5D{sub 5/2} levels. This atomic configuration can show electromagnetically induced transparency and absorption processes. The error signal comes from the difference in the transparency or absorption felt by the two orthogonal polarizations of the probe beam. A simplified model is in good quantitative agreement with the observed signals for the experimental parameters. We have used this technique to lock the frequency of the laser up to 1.5 GHz off atomic resonance.

  16. Determination of elements by atomic absorption spectrometry in medicinal plants employed to alleviate common cold symptoms.

    PubMed

    Küçükbay, F Zehra; Kuyumcu, Ebru

    2014-09-01

    Eleven important medicinal plants generally used by the people of Turkey for the treatment of common cold have been studied for their mineral contents. Eleven minor and major elements (essential, non-essential and toxic) were identified in the Asplenium adiantum-nigrum L. , Althaea officinalis L. , Verbascum phlomoides L., Euphorbia chamaesyce L., Zizyphus jujube Miller, Peganum harmala L., Arum dioscoridis Sm., Sambucus nigra L., Piperlongum L., Tussilago farfara L. and Elettaria cardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrometry. Microwave digestion procedure for total concentration was applied under optimized conditions for dissolution of medicinal plants. Plant based biological certified reference materials (CRMs) served as standards for quantification. These elements are found to be present in varying concentrations in the studied plants. The baseline data presented in this work can be used in understanding the role of essential, non-essential and toxic elements in nutritive, preventive and therapeutic properties of medicinal plants.

  17. Cadmium, copper, lead, and zinc determination in precipitation: A comparison of inductively coupled plasma atomic emission spectrometry and graphite furnace atomization atomic absorption spectrometry

    USGS Publications Warehouse

    Reddy, M.M.; Benefiel, M.A.; Claassen, H.C.

    1987-01-01

    Selected trace element analysis for cadmium, copper, lead, and zinc in precipitation samples by inductively coupled plasma atomic emission Spectrometry (ICP) and by atomic absorption spectrometry with graphite furnace atomization (AAGF) have been evaluated. This task was conducted in conjunction with a longterm study of precipitation chemistry at high altitude sites located in remote areas of the southwestern United States. Coefficients of variation and recovery values were determined for a standard reference water sample for all metals examined for both techniques. At concentration levels less than 10 micrograms per liter AAGF analyses exhibited better precision and accuracy than ICP. Both methods appear to offer the potential for cost-effective analysis of trace metal ions in precipitation. ?? 1987 Springer-Verlag.

  18. Analysis of Mercurial Preservatives in Bacterins, Vaccines, and Antisera by Atomic Absorption Spectrophotometry

    PubMed Central

    Woodward, Paul W.; Pemberton, John R.

    1974-01-01

    A flameless atomic absorption method was developed for the determination of mercurial preservatives in biologicals. The assay was based on a quantitative determination of the mercury content of these preservatives. This method was used to analyze a variety of samples and yielded reproducible results with satisfactory recoveries. The procedure is presented in a simplified block diagram and described in detail relating its suitability for routine assay of large numbers of samples. PMID:4833363

  19. Literature study of microwave-assisted digestion using electrothermal atomic absorption spectrometry.

    PubMed

    Chakraborty, R; Das, A K; Cervera, M L; De La Guardia, M

    1996-05-01

    The literature on the use of microwave-assisted digestion procedures for subsequent sample analysis by means of electrothermal atomic absorption spectrometry (ETAAS) is reviewed. The literature survey reveals that this digestion technique has been applied mainly for biological materials. The elements most extensively determined by this method are cadmium and lead followed by copper, chromium, nickel and iron. The microwave digestion conditions, ETAAS furnace programmes and analytical details of the developed methodologies have been carefully revised.

  20. Digestion of fish samples for mercury determination by flameless atomic absorption spectrophotometry.

    PubMed

    Pearce, I D; Brooks, R R; Reeves, R D

    1976-05-01

    Methods of digestion of fish samples for mercury determination by flameless atomic absorption spectrophotometry have been investigated. Digestion in Teflon bombs, Kjeldahl flasks, or borosilicate test tubes gives comparable precisions and mercury recoveries. Because of their cost and effect in limiting productivity, Teflon bombs were considered unnecessary for analysis of fish samples. Experiments with cooked and uncooked fish samples have confirmed that no appreciable loss of mercury occurs during baking 30 min at 170 degrees C.

  1. Speciation analysis of arsenic in biological matrices by automated hydride generation-cryotrapping-atomic absorption spectrometry with multiple microflame quartz tube atomizer (multiatomizer).

    EPA Science Inventory

    This paper describes an automated system for the oxidation state specific speciation of inorganic and methylated arsenicals by selective hydride generation - cryotrapping- gas chromatography - atomic absorption spectrometry with the multiatomizer. The corresponding arsines are ge...

  2. Speciation analysis of arsenic in biological matrices by automated hydride generation-cryotrapping-atomic absorption spectrometry with multiple microflame quartz tube atomizer (multiatomizer).

    EPA Science Inventory

    This paper describes an automated system for the oxidation state specific speciation of inorganic and methylated arsenicals by selective hydride generation - cryotrapping- gas chromatography - atomic absorption spectrometry with the multiatomizer. The corresponding arsines are ge...

  3. An atomic-absorption spectrometer with an electrothermal atomizer in a magnetic field

    SciTech Connect

    Eristavi, V.D; Ivanov, V.K.; Sadagov, Y.M.; Sharashidze, P.A.

    1986-08-01

    This paper describes a system for correcting unselective interference. The system enables one to amplify the preparation of specimens of complicated composition, and it increases the accuracy at the expense of only a very slight sensitivity loss. The Zeeman AA spectrometer with electrothermal atomizer is shown and is based on the optical system of an S-302 AA spectrometer. The resonant-radiation sources were VSB-2 electrodeless high-frequency lamps or 1SP-1 hollow-cathode ones supplied with dc. The system for correcting for unselective interference enables one to simplify the preparation of specimens of complicated composition and it increases the accuracy at the expense of only a very slight sensitivity loss.

  4. Measurement of metastable Ar atom density in atmospheric-pressure microgap discharge using laser absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Kono, Akihiro; Shibata, Tomoyuki; Aramaki, Mitsutoshi

    2006-10-01

    Atmospheric-pressure Ar glow discharge in a microgap between two knife-edge electrodes (10-mm length, 100-μm gap separation) driven by 2.45-GHz microwave is being studied aiming at an application to VUV excimer light source. One of the knife-edge electrodes has a gas sink at its ridge, enabling introducing gas flow through the discharge plasma. The density of metastable Ar atoms, which are precursors of excimer molecules, is studied using laser absorption spectroscopy. The beam of a tunable diode laser at wavelengths around 696.5 nm is arranged to pass through the microgap obliquely to have an absorption path length of ˜1 mm. At a microwave power of 10 W, the observed absorption at the line center was ˜10% with a pressure broadened line width of ˜13 GHz, giving metastable Ar atom density of 3x10^13 cm-3. In a similar condition, the electron density measured using a laser Thomson scattering technique was 3x10^14 cm-3. The behavior of metastable atom density for varying discharge conditions is under investigation. (Work supported by Grant-in-aid 15075205 from MEXT Japan.)

  5. Determination of platinum originated from antitumoral drugs in human urine by atomic absorption spectrometric methods.

    PubMed

    da Costa, Anilton Coelho; Vieira, Mariana Antunes; Luna, Aderval Severino; de Campos, Reinaldo Calixto

    2010-10-15

    Cisplatin and carboplatin are the most common platinum-based drugs used in cancer treatment. Pharmacokinetic investigations, the evaluation of the body burden during the treatment, as well as baseline levels of platinum in humans have attracted great interest. Thus, accurate analytical methods for fast and easy Pt monitoring in clinical samples become necessary. In the present study atomic absorption spectrometric methods for the determination of platinum in the forms of cisplatin and carboplatin in human urine were investigated. Platinum, in these different forms, could be determined in urine, after simple sample dilution. Regarding electrothermal atomic absorption spectrometry, the optimum parameters were defined by a central composite design optimization. Multiplicative matrix effects were overcome by using a mixture of HCl and NaCl as modifier. The limit of detection (LOD) was 0.004 mgL(-1) of platinum in the original sample. For the analysis of more concentrated samples, high resolution continuous source flame atomic absorption spectrometry was also investigated. Flame conditions were optimized by a multivariate D-optimal design, using as response the sum of the analyte addition calibration slopes and their standard deviations. Matrix matched external calibration with PtCl(2) calibration solutions, was possible, and the LOD was 0.06 mgL(-1) in the original sample. The results obtained by the proposed procedures were also in good agreement with those obtained by an independent comparative procedure.

  6. Time-resolved Absorption Spectra of the Laser-dressed Hydrogen Atom

    NASA Astrophysics Data System (ADS)

    Murakami, Mitsuko; Chu, Shih-I.

    2013-05-01

    A theoretical study of the transient absorption spectra for the laser-dressed hydrogen atom based on the accurate numerical solution of the time-dependent Schrödinger equation is presented. The timing of absorption is controlled by the time delay between an isolated extreme ultraviolet (XUV) pulse and a dressing infrared (IR) field. We identify two different kinds of physical processes in the spectra. One is the formation of dressed states, signified by the appearance of sidebands between the XUV absorption lines separated by one IR-photon energy. We show that their population is maximized when the XUV pulse coincides with the zero-crossing of the IR field, and that their energy can be manipulated by using a chirped IR field. The other process is the dynamical AC Stark shift induced by the IR field and probed by the XUV pulse. Our calculations indicate that the accidental degeneracy of the hydrogen atom leads to the multiple splittings of each XUV absorption line whose separations change in response to a slowly-varying IR envelope. Furthermore, we observe the Autler-Townes doublets for the n=2 and 3 states using the 656 nm dressing field, but their separation does not agree with the prediction by the conventional 3-level model that neglects the dynamical AC Stark effects.

  7. Self-assembly based plasmonic arrays tuned by atomic layer deposition for extreme visible light absorption.

    PubMed

    Hägglund, Carl; Zeltzer, Gabriel; Ruiz, Ricardo; Thomann, Isabell; Lee, Han-Bo-Ram; Brongersma, Mark L; Bent, Stacey F

    2013-07-10

    Achieving complete absorption of visible light with a minimal amount of material is highly desirable for many applications, including solar energy conversion to fuel and electricity, where benefits in conversion efficiency and economy can be obtained. On a fundamental level, it is of great interest to explore whether the ultimate limits in light absorption per unit volume can be achieved by capitalizing on the advances in metamaterial science and nanosynthesis. Here, we combine block copolymer lithography and atomic layer deposition to tune the effective optical properties of a plasmonic array at the atomic scale. Critical coupling to the resulting nanocomposite layer is accomplished through guidance by a simple analytical model and measurements by spectroscopic ellipsometry. Thereby, a maximized absorption of light exceeding 99% is accomplished, of which up to about 93% occurs in a volume-equivalent thickness of gold of only 1.6 nm. This corresponds to a record effective absorption coefficient of 1.7 × 10(7) cm(-1) in the visible region, far exceeding those of solid metals, graphene, dye monolayers, and thin film solar cell materials. It is more than a factor of 2 higher than that previously obtained using a critically coupled dye J-aggregate, with a peak width exceeding the latter by 1 order of magnitude. These results thereby substantially push the limits for light harvesting in ultrathin, nanoengineered systems.

  8. Studies on mass energy-absorption coefficients and effective atomic energy-absorption cross sections for carbohydrates

    NASA Astrophysics Data System (ADS)

    Ladhaf, Bibifatima M.; Pawar, Pravina P.

    2015-04-01

    We measured here the mass attenuation coefficients (μ/ρ) of carbohydrates, Esculine (C15H16O9), Sucrose (C12H22O11), Sorbitol (C6H14O6), D-Galactose (C6H12O6), Inositol (C6H12O6), D-Xylose (C5H10O5) covering the energy range from 122 keV up to 1330 keV photon energies by using gamma ray transmission method in a narrow beam good geometry set-up. The gamma-rays were detected using NaI(Tl) scintillation detection system with a resolution of 8.2% at 662 keV. The attenuation coefficient data were then used to obtain the total attenuation cross-section (σtot), molar extinction coefficients (ε), mass-energy absorption coefficients (μen/ρ) and effective (average) atomic energy-absorption cross section (σa,en) of the compounds. These values are found to be in good agreement with the theoretical values calculated based on XCOM data.

  9. [Application of solid sampling graphite furnace atomic absorption spectrophotometry to mensuration of brain iron content in rats].

    PubMed

    Zhang, Nan; Sheng, Qing-hai; Shi, Zhen-hua; Zhang, Zhi-guo; Duan, Xiang-lin; Chang, Yan-zhong

    2009-04-01

    In the present study, the authors performed the solid sampling and detected the iron levels in cortex, hippocampus and striatum of rat brain by GFAAS. The authors' results showed that there are no remarkable difference between the data obtained by solid sampling graphite furnace atomic absorption and liquid sampling graphite furnace atomic absorption. Compared to liquid sampling graphite furnace atomic absorption, the sample pre-treatment stage was obviously simplified, the cost was reduced significantly, and the time was shortened significantly in the solid sampling GFAAS. This study will be beneficial to the mensuration of iron content in micro-tissue of animal by solid sampling GFASS.

  10. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Matusiewicz, Henryk; Krawczyk, Magdalena

    2007-03-01

    The analytical performance of coupled hydride generation — integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H 2Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements (a water-cooled single silica tube, double-slotted quartz tube or an "integrated trap") was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3 σ), was 0.9 ng mL - 1 for Te. For a 2 min in situ pre-concentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation — atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% ( n = 6) for Te. The designs studied include slotted tube, single silica tube and integrated atom trap-cooled atom traps. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  11. Investigation of chemical modifiers for phosphorus in a graphite furnace using high-resolution continuum source atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Lepri, Fábio G.; Dessuy, Morgana B.; Vale, Maria Goreti R.; Borges, Daniel L. G.; Welz, Bernhard; Heitmann, Uwe

    2006-08-01

    Phosphorus is not one of the elements that are typically determined by atomic absorption spectrometry, but this technique nevertheless offers several advantages that make it attractive, such as the relatively great freedom from interferences. As the main resonance lines for phosphorus are in the vacuum-ultraviolet, inaccessible by conventional atomic absorption spectrometry equipment, Ĺvov and Khartsyzov proposed to use the non-resonance doublet at 213.5 / 213.6 nm. Later it turned out that with conventional equipment it is necessary to use a chemical modifier in order to get reasonable sensitivity, and lanthanum was the first one suggested for that purpose. In the following years more than 30 modifiers have been proposed for the determination of this element, and there is no consensus about the best one. In this work high-resolution continuum source atomic absorption spectrometry has been used to investigate the determination of phosphorus without a modifier and with the addition of selected modifiers of very different nature, including the originally recommended lanthanum modifier, several palladium-based modifiers and sodium fluoride. As high-resolution continuum source atomic absorption spectrometry is revealing the spectral environment of the analytical line at high resolution, it became obvious that without the addition of a modifier essentially no atomic phosphorus is formed, even at 2700 °C. The absorption measured with line source atomic absorption spectrometry in this case is due to the PO molecule, the spectrum of which is overlapping with the atomic line. Palladium, with or without the addition of calcium or ascorbic acid, was found to be the only modifier to produce almost exclusively atomic phosphorus. Lanthanum and particularly sodium fluoride produced a mixture of P and PO, depending on the atomization temperature. This fact can explain at least some of the discrepancies found in the literature and some of the phenomena observed in the

  12. Concentration of atomic hydrogen in a dielectric barrier discharge measured by two-photon absorption fluorescence

    NASA Astrophysics Data System (ADS)

    Dvořák, P.; Talába, M.; Obrusník, A.; Kratzer, J.; Dědina, J.

    2017-08-01

    Two-photon absorption laser-induced fluorescence (TALIF) was utilized for measuring the concentration of atomic hydrogen in a volume dielectric barrier discharge (DBD) ignited in mixtures of Ar, H2 and O2 at atmospheric pressure. The method was calibrated by TALIF of krypton diluted in argon at atmospheric pressure, proving that three-body collisions had a negligible effect on quenching of excited krypton atoms. The diagnostic study was complemented with a 3D numerical model of the gas flow and a zero-dimensional model of the chemistry in order to better understand the reaction kinetics and identify the key pathways leading to the production and destruction of atomic hydrogen. It was determined that the density of atomic hydrogen in Ar-H2 mixtures was in the order of 1021 m-3 and decreased when oxygen was added into the gas mixture. Spatially resolved measurements and simulations revealed a sharply bordered region with low atomic hydrogen concentration when oxygen was added to the gas mixture. At substoichiometric oxygen/hydrogen ratios, this H-poor region is confined to an area close to the gas inlet and it is shown that the size of this region is not only influenced by the chemistry but also by the gas flow patterns. Experimentally, it was observed that a decrease in H2 concentration in the feeding Ar-H2 mixture led to an increase in H production in the DBD.

  13. Determination of total magnesium in biological samples using electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Hulanicki, Adam; Godlewska, Beata; Brzóska, Malgorzata

    1995-11-01

    Magnesium content is an important diagnostic parameter in medicine. It is recognized that its determination in one compartment is not sufficient for reliable information about the magnesium status in the body. In addition to the common procedures of magnesium determination in blood by flame atomic absorption spectrometry, the procedure of electrothermal atomization has also been developed and applied to the analysis of blood fractions, mononuclear cells and isolated nuclei of liver cells. Electrothermal atomization is preferred in cases where the sample size is limited and the magnesium content low. The total errors are in the order of 3-4%. Various techniques of sample pretreatment have been tested and direct dilution with 0.05 mol l -1 nitric acid was optimal when the samples were not mineralized. The calibration graph based on standards containing albumin was found to give the best results, as the form of magnesium in the samples may influence the ashing and atomization processes. Good agreement was obtained for determination of magnesium in standard serum. The results are compared with those obtained by the standard flame atomization technique.

  14. Method 200.12 - Determination of Trace Elements in Marine Waters by StabilizedTemperature Graphite Furnace Atomic Absorption

    EPA Science Inventory

    This method provides procedures for the determination of total recoverable elements by graphite furnace atomic absorption (GFAA) in marine waters, including estuarine, ocean and brines with salinities of up to 35 ppt.

  15. Method 200.12 - Determination of Trace Elements in Marine Waters by StabilizedTemperature Graphite Furnace Atomic Absorption

    EPA Science Inventory

    This method provides procedures for the determination of total recoverable elements by graphite furnace atomic absorption (GFAA) in marine waters, including estuarine, ocean and brines with salinities of up to 35 ppt.

  16. Low-resolution continuum source simultaneous multi-element electrothermal atomic absorption spectrometry: steps into practice

    NASA Astrophysics Data System (ADS)

    Katskov, Dmitri

    2015-03-01

    The theory and practical problems of continuum source simultaneous multi-element electrothermal atomic absorption spectrometry (SMET AAS) are discussed by the example of direct analysis of underground water. The experimental methodology is based on pulse vaporization of the sample in a fast heated graphite tube and measurement of transient absorption of continuum spectrum radiation from D2 and Xe lamps within 200-400 nm wavelengths range with a low resolution spectral instrument and linear charge-coupled device. The setup permits the acquisition of 200 spectra during 1 s atomization pulse. Respective data matrix absorbance vs wavelength/time is employed for the quantification of elements in the sample. The calculation algorithm developed includes broad band and continuum background correction, linearization of function absorbance vs. concentration of atomic vapor and integration of thus modified absorbance at the resonance lines of the elements to be determined. Practical application shows that the method can be employed for the direct simultaneous determination of about 20 elements above microgram per liter level within 3-5 orders of the magnitude concentration range. The investigated sources of measurement errors are mainly associated with the atomization and vapor transportation problems, which are aggravated for the simultaneous release of major and minor sample constituents. Respective corrections concerning the selection of analytical lines, optimal sampling volume, matrix modification and cleaning of the atomizer have been introduced in the SMET AAS analytical technology. Under the optimized experimental conditions the calibration curves in Log-Log coordinates for all the investigated analytes in the single or multi-element reference solutions are approximated by the first order equations. The use of these equations as permanent characteristics of the setup enables instant quantification of Al, Ca, Co, Cr, Cu, Fe, Mg, Mn and Ni in the underground water

  17. Cascade splitting of two atomic energy levels due to multiphoton absorption

    NASA Astrophysics Data System (ADS)

    Ruan, Ya-Ping; Jia, Feng-Dong; Sun, Zhen; Lv, Shuang-Fei; Qing, Bo; Huang, Wei; Xue, Ping; Xu, Xiang-Yuan; Dai, Xing-Can; Zhong, Zhi-Ping

    2014-09-01

    We have theoretically and experimentally studied the spectroscopic properties of dressed levels in a strong monochromatic field, and propose a model of cascade splitting of two atomic energy levels. In this model two related dressed levels can be split into four levels, and transitions connecting four new levels will constitute spectroscopic structures. Two types of proof-in-principle experiments are performed to verify the model. One experiment measures the probe absorption spectra of a degenerate two-level atomic system with two strong monochromatic coupling fields. The system consists of 52S1/2,F=2 and 52P3/2,F'=3 states of Rb87 atoms in a magneto-optical trap (MOT) as well as the cooling beams and an additional coupling field. New spectral features are observed and proven to be due to the transitions of new levels generated by splitting of the dressed levels. The other experiment measures the pump-probe spectra in a degenerate two-level atomic system with one strong monochromatic coupling field. The system consists of 52S1/2,F=2 and 52P3/2,F'=3 states of the Rb87 atom in a magneto-optical trap and one coupling field. We have observed spectral features that obviously differ from the prediction that comes from the two-level dressed-atom approach. They cannot be explained by existing theories. The model of cascade splitting of two atomic energy levels is employed to explain the observations in these two types of experiments.

  18. Solution and slurry sampling electrothermal atomic absorption spectrometry for the analysis of high purity quartz

    NASA Astrophysics Data System (ADS)

    Hauptkorn, Susanne; Krivan, Viliam

    1996-07-01

    A slurry sampling electrothermal atomic absorption spectrometry (ETAAS) method for the determination of Al, Cr, Cu, Fe, K, Li, Mg, Mn and Na at trace and ultratrace level in high purity quartz samples has been developed. The influence of atomization temperature, internal gas flow during atomization and carbide modification of the graphite tube on the background absorption has been studied. Simple quantification via calibration curves, recorded with aqueous standards, is possible for all elements except Al. The performance and the accuracy of the slurry sampling technique are compared to those of the analysis of hydrofluoric acid digests. With both methods, the blanks could be substantially reduced by minimization of sample handling. Because of essentially higher applicable sample portions, the solution technique provides lower limits of detection for all elements excluding Al, Na and K. For the slurry sampling technique, the achievable limits of detection are in the range of 2 (Mg) to 500 (Fe) ng g -1 and for the solution technique, they are between 0.4 (Mg) and 500 (Al) ng g -1. Thus, both developed methods are well suited for ultratrace analysis of high purity quartz for microelectronic applications. The results obtained by these two ETAAS techniques are compared with those of independent methods including neutron activation analysis.

  19. Ground state bromine atom density measurements by two-photon absorption laser-induced fluorescence

    NASA Astrophysics Data System (ADS)

    Sirse, N.; Foucher, M.; Chabert, P.; Booth, J.-P.

    2014-12-01

    Ground state bromine atom detection by two-photon absorption laser-induced fluorescence (TALIF) is demonstrated. The (4p5) {^2Po3/2} bromine atoms are excited by two-photon absorption at 252.594 nm to the (5p) {^4So3/2} state and detected by 635.25 nm fluorescence to the (5s) 4P5/2 state. The atoms are generated in a radio-frequency inductively-coupled plasma in pure HBr. The excitation laser also causes some photodissociation of HBr molecules, but this can be minimized by not focussing the laser beam, still giving adequate signal levels. We determined the natural lifetime of the emitting (5p) {^4So3/2} state, τf^Br*=30.9 +/- 1.4 ns and the rate constant for quenching of this state by collision with HBr molecules, k_HBrQ = 1.02 +/- 0.07× 10-15 m3 s-1 .

  20. Metal furnace heated by flame as a hydride atomizer for atomic absorption spectrometry: Sb determination in environmental and pharmaceutical samples.

    PubMed

    Figueiredo, Eduardo Costa; Dĕdina, Jirí; Arruda, Marco Aurélio Zezzi

    2007-10-15

    The present work describes a metallic hydride atomizer for atomic absorption spectrometry, by evaluating the performance of the Inconel 600((R)) tube. For this purpose, stibine was used as the model volatile compound and antimony determination in river and lake sediments and in pharmaceutical samples was carried out to assess the metal furnace performance. Some parameters are evaluated such as those referring to the generation and transport of the hydride (such as KBH(4) and acid concentrations, carrier gas flow rate, injected volume, etc.), as well as those referring to the metal furnace (such as tube hole area, flame composition, long-term stability, etc.). The method presents linear Sb concentration from 2 to 80mugL(-1) range (r>0.998; n=3) and the analytical frequency of ca. 140h(-1). The limit of detection (LOD) is 0.23mugL(-1) and the precision, expressed as R.S.D., is less than 5% (40mugL(-1); n=10). The accuracy is evaluated through the reference materials, and the results are similar at 95% confidence level according to the t-test.

  1. Direct determination of arsenic in petroleum derivatives by graphite furnace atomic absorption spectrometry: A comparison between filter and platform atomizers

    NASA Astrophysics Data System (ADS)

    Becker, Emilene; Rampazzo, Roger T.; Dessuy, Morgana B.; Vale, Maria Goreti R.; da Silva, Márcia M.; Welz, Bernhard; Katskov, Dmitri A.

    2011-05-01

    In the present work a direct method for the determination of arsenic in petroleum derivatives has been developed, comparing the performance of a commercial transversely heated platform atomizer (THPA) with that of a transversely heated filter atomizer (THFA). The THFA results in a reduction of background absorption and an improved sensitivity as has been reported earlier for this atomizer. The mixture of 0.1% (m/v) Pd + 0.03% (m/v) Mg + 0.05% (v/v) Triton X-100 was used as the chemical modifier for both atomizers. The samples (naphtha, gasoline and petroleum condensate) were stabilized in the form of a three-component solution (detergentless microemulsion) with the sample, propan-1-ol and 0.1% (v/v) HNO 3 in a ratio of 3.0:6.4:0.6. The characteristic mass of 13 pg found in the THFA was about a factor of two better than that of 28 pg obtained with the THPA; however, the limits of detection (LOD) and quantification (LOQ) were essentially the same for both atomizers (1.9 and 6.2 μg L -1, respectively, for THPA, and 1.8 and 5.9 μg L -1, respectively, for THFA) due to the increased noise observed with the THFA. A possible explanation for that is a partial blockage of the radiation from the hollow cathode lamp by the narrow inner diameter of this tube and the associated loss of radiation energy. Due to the lack of an appropriate certified reference material, recovery tests were carried out with inorganic and organic arsenic standards and the results were between 89% and 111%. The only advantage of the THFA found in this work was a reduction of the total analysis time by about 20% due to the 'hot injection' that could be realized with this furnace. The arsenic concentrations varied from < LOQ to 43.3 μg L -1 in the samples analyzed in this work.

  2. [Determination of aluminum in sediments by atomic absorption spectrophotometer without FIA spectrophotometric analysis].

    PubMed

    Zhao, Zhen-yi; Han, Guang-xi; Song, Xi-ming; Luo, Zhi-xiong

    2008-06-01

    To search for a new method of determining, we developed a new flow injection analyzer, applied to the atomic absorption spectrophotometer, relying on it without flame in place of visible spectrophotometer, and studied the appropriate condition for the determination of aluminum in sediments, thus built up a kind of new analytical test technique. Three peak and two valley absorption values (A1, A2, A3, A4 and A5) can be continuously obtained simultaneously that all can be used for quantitative analysis, then we discussed its theory and experiment technique. Based on the additivity of absorbance (A = A1+A2+A3+A4+ A5), the sensitivity of FIA is enhanced, and its precision and linear relation are also good, raising the efficiency of AAS. The simple method has been applied to determining Al in sediments, and the results are satisfactory.

  3. Ablation-initiated Isotope-selective Atomic Absorption Spectroscopy of Lanthanide Elements

    SciTech Connect

    Miyabe, M.; Oba, M.; Iimura, H.; Akaoka, K.; Maruyama, Y.; Wakaida, I.; Watanabe, K.

    2009-03-17

    For remote isotope analysis of low-decontaminated trans-uranium (TRU) fuel, absorption spectroscopy has been applied to a laser-ablated plume of lanthanide elements. To improve isotopic selectivity and detection sensitivity of the ablated species, various experimental conditions were optimized. Isotope-selective absorption spectra were measured by observing the slow component of the plume produced under low-pressure rare-gas ambient. The measured minimum line width of about 0.9 GHz was close to the Doppler width of the Gd atomic transition at room temperature. The relaxation rate of high-lying metastable state was found to be higher than that of the ground state, which suggests that higher analytical sensitivity can be obtained using low-lying state transition. Under helium gas environment, Doppler splitting was caused from particle motion. This effect was considered for optimization for isotope selection and analysis. Some analytical performances of this method were determined under optimum conditions and were discussed.

  4. Possible atomic structures responsible for the sub-bandgap absorption of chalcogen-hyperdoped silicon

    SciTech Connect

    Wang, Ke-Fan; Shao, Hezhu; Liu, Kong; Qu, Shengchun E-mail: wangyx@henu.edu.cn; Wang, Zhanguo; Wang, Yuanxu E-mail: wangyx@henu.edu.cn

    2015-09-14

    Single-crystal silicon was hyperdoped with sulfur, selenium, and tellurium using ion implantation and nanosecond laser melting. The hyperdoping of such chalcogen elements led to strong and wide sub-bandgap light absorption. Annealing the hyperdoped silicon, even at low temperatures (such as 200–400 °C), led to attenuation of the sub-bandgap absorption. To explain the attenuation process, we modeled it as chemical decomposition reaction from an optically absorbing structure to a non-absorbing structure. Attenuation of the experimental absorption coefficient was fit using the Arrhenius equation. From the fitted data, we extracted the reaction activation energies of S-, Se-, and T-hyperdoped silicon as 0.338 ± 0.029 eV, 0.471 ± 0.040 eV, and 0.357 ± 0.028 eV, respectively. We discuss these activation energies in terms of the bond energies of chalcogen–Si metastable bonds, and suggest that several high-energy interstitial sites, rather than substitutional sites, are candidates for the atomic structures that are responsible for the strong sub-bandgap absorption of chalcogen hyperdoped silicon.

  5. Application of thermospray flame furnace atomic absorption spectrometry for investigation of silver nanoparticles.

    PubMed

    Sirirat, Natnicha; Tetbuntad, Kornrawee; Siripinyanond, Atitaya

    2017-03-01

    Thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was applied to investigate the time-dependent absorption peak profile of various forms of silver. The thermospray flame furnace was set up with a 10-cm-long nickel tube with six holes, each 2.0 mm in diameter, to allow the flame to enter, and this nickel tube acted as a furnace. A sample of 300 μL was introduced into this furnace by use of water as a carrier at a flow rate of 0.5 mL min(-1) through the ceramic capillary (0.5-mm inner diameter and 2.0-mm outer diameter), which was inserted into the front hole of the nickel tube. The system was applied to examine atomization behaviors of silver nanoparticles (AgNPs) with particle sizes ranging from 10 to 100 nm. The atomization rate of AgNPs was faster than that of the dissolved silver ion. With increased amount of silver, the decay time observed from the time-dependent absorption peak profile was shortened in the case of dissolved silver ion, but it was increased in the case of AgNPs. With the particle size ranging from 10 to 100 nm, the detection sensitivity was indirectly proportional to the particle size, suggesting that TS-FF-AAS may offer insights into the particle size of AgNPs provided that the concentration of the silver is known. To obtain quantitative information on AgNPs, acid dissolution of the particles was performed before TS-FF-AAS analysis, and recoveries of 80-110% were obtained.

  6. Extended calibration ranges for continuum source atomic absorption spectrometry with array detection

    NASA Astrophysics Data System (ADS)

    Harnly, James M.; Smith, Clare M. M.; Radziuk, Bernard

    1996-07-01

    Computer modeling has been used to construct calibration curves and relative concentration error plots for continuum source atomic absorption spectrometry with array detection and graphite furnace atomization. Model results are compared with experimental results obtained with a linear photodiode array detector. The model uses a Lorentzian absorption profile convoluted with a rectangular entrance slit (25, 50, 100, 200, or 500 μm wide) and detected with an array of pixels (each 25 μm wide) using a high resolution spectrometer. Transient furnace signals are modeled as triangular functions with a half-width of 2 s whose height and area are linearly dependent on concentration. With detector read noise limiting (characteristic of a photodiode array detector), the best signal-to-noise ratios have been obtained with a 500 μm entrance slit width and wavelength integrated absorbance (i.e. integration of absorbance over the whole absorption profile). The shapes of the modeled calibration curves agree well with those theoretically predicted and those obtained experimentally. Useful calibration ranges approaching six orders of magnitude of concentration have been achieved using a single calibration curve and integrating over a spectral region equivalent to 60 times the half width of the absorption profile (about 0.16 nm for Cd at 228.8 nm). When concentration is normalized by the intrinsic mass, all elements give the same curve shapes with the inflection point, from a slope of 1.0 to 0.5 (on a logarithmic scale), determined by the stray light. A hyperbolic function has been developed which accurately fits the modeled and experimental data. With photon shot noise limiting (characteristic of a charge coupled device), the signal-to-noise ratio is much less dependent on the entrance slit width. With a 25 μm entrance slit width, wavelength selected absorbances (i.e. absorbances computed for selected pixels or wavelengths) have been used to construct three calibration curves

  7. Absorption spectroscopy characterization measurements of a laser-produced Na atomic beam

    SciTech Connect

    Ching, C.H.; Bailey, J.E.; Lake, P.W.; Filuk, A.B.; Adams, R.G.; McKenney, J.

    1997-01-01

    A pulsed Na atomic beam source developed for spectroscopic diagnosis of a high-power ion diode is described. The goal is to produce a {approximately}10{sup 12}-cm{sup {minus}3}-density Na atomic beam that can be injected into the diode acceleration gap to measure electric and magnetic fields from the Stark and Zeeman effects through laser-induced fluorescence or absorption spectroscopy. A {approximately}10 ns full width at half-maximum (FWHM), 1.06 {mu}m, 0.6 J/cm{sup 2} laser incident through a glass slide heats a Na-bearing thin film, creating a plasma that generates a sodium vapor plume. A {approximately}1 {mu}s FWHM dye laser beam tuned to 5890 {Angstrom} is used for absorption measurement of the NaI resonant doublet by viewing parallel to the film surface. The dye laser light is coupled through a fiber to a spectrograph with a time-integrated charge-coupled-device camera. A two-dimensional mapping of the Na vapor density is obtained through absorption measurements at different spatial locations. Time-of-flight and Doppler broadening of the absorption with {approximately}0.1 {Angstrom} spectral resolution indicate that the Na neutral vapor temperature is about 0.5{endash}2 eV. Laser-induced fluorescence from {approximately}1{times}10{sup 12} cm{sup {minus}3} NaI 3s-3p lines observed with a streaked spectrograph provides a signal level sufficient for {approximately}{plus_minus}0.06 {Angstrom} wavelength shift measurements in a mock-up of an ion diode experiment. {copyright} {ital 1997 American Institute of Physics.}

  8. Absorption spectroscopy characterization measurements of a laser-produced Na atomic beam

    SciTech Connect

    Ching, C.H.; Bailey, J.E.; Lake, P.W.; Filuk, A.B.; Adams, R.G.; McKenney, J.

    1996-06-01

    This work describes a pulsed Na atomic beam source developed for spectroscopic diagnosis of a high-power ion diode on the Particle Beam Fusion Accelerator II. The goal is to produce a {approximately} 10{sup 12}-cm{sup {minus}3}-density Na atomic beam that can be injected into the diode acceleration gap to measure electric and magnetic fields from the Stark and Zeeman effects through laser-induced-fluorescence or absorption spectroscopy. A {approximately} 10 ns fwhm, 1.06 {micro}m, 0.6 J/cm{sup 2} laser incident through a glass slide heats a Na-bearing thin film, creating a plasma that generates a sodium vapor plume. A {approximately} 1 {micro}sec fwhm dye laser beam tuned to 5,890 {angstrom} is used for absorption measurement of the Na I resonant doublet by viewing parallel to the film surface. The dye laser light is coupled through a fiber to a spectrograph with a time-integrated CCD camera. A two-dimensional mapping of the Na vapor density is obtained through absorption measurements at different spatial locations. Time-of-flight and Doppler broadening of the absorption with {approximately} 0.1 {angstrom} spectral resolution indicate that the Na neutral vapor temperature is about 0.5 to 2 eV. Laser-induced-fluorescence from {approximately} 1 {times} 10{sup 12}-cm{sup {minus}3} Na I 3s-3p lines observed with a streaked spectrograph provides a signal level sufficient for {approximately} 0.06 {angstrom} wavelength shift measurements in a mock-up of an ion diode experiment.

  9. [Determination of trace selenium in edible fungi with graphite furnace atomic absorption spectroscopy].

    PubMed

    Tie, Mei; Zhang, Wei; Li, Jing; Jing, Kui; Zang, Shu-liang; Li, Hua-wei

    2006-01-01

    In the present article, samples were digested by a quartz high-pressure digestion pot, reducing the loss of selenium in digestion. The content of selenium in edible fungi was determined by using graphite furnace atomic absorption spectroscopy, and the results showed that when the content of selenium in edible fungi was determined by using 1% Ni(NO3)2 as a matrix modifier, ashing temperature of 500 degreed C, and atomization temperature of 2 500 degrees C, and rectifying background by deuterium light, the recovery was in the range of 92.1%-115.5%, the relative standard deviation of the method was 1.28%, and the limit of detection was 15.8 microg x L(-1). The method was suitable for the determination of trace selenium in edible fungi with the advantages of being simple, rapid, sensitive, stable and accurate etc., and the results were satisfactory.

  10. Determination of ruthenium in pharmaceutical compounds by graphite furnace atomic absorption spectroscopy.

    PubMed

    Jia, Xiujuan; Wang, Tiebang; Bu, Xiaodong; Tu, Qiang; Spencer, Sandra

    2006-04-11

    A graphite furnace atomic absorption (GFAA) spectrometric method for the determination of ruthenium (Rh) in solid and liquid pharmaceutical compounds has been developed. Samples are dissolved or diluted in dimethyl sulfoxide (DMSO) without any other treatment before they were analyzed by GFAA with a carefully designed heating program to avoid pre-atomization signal loss and to achieve suitable sensitivity. Various inorganic and organic solvents were tested and compared and DMSO was found to be the most suitable. In addition, ruthenium was found to be stable in DMSO for at least 5 days. Spike recoveries ranged from 81 to 100% and the limit of quantitation (LOQ) was determined to be 0.5 microg g(-1) for solid samples or 0.005 microg ml(-1) for liquid samples based a 100-fold dilution. The same set of samples was also analyzed by ICP-MS with a different sample preparation method, and excellent agreement was achieved.

  11. Determination of tellurium in geochemical materials by flameless atomic-absorption spectroscopy.

    PubMed

    Sighinolfi, G P; Santos, A M; Martinelli, G

    1979-02-01

    A method is described for the determination of tellurium at nanogram levels in rocks and in other complex materials by the use of flameless atomic-absorption spectroscopy. A very selective organic extraction procedure is applied to avoid matrix interference effects during extraction of Te and the atomization stage in the graphite furnace. Prior separation of iron and other interfering elements is achieved by a combined cupferron-ethyl acetate extraction. Tellerium is extracted from 6M hydrochloric acid with MIBK and stripped into aqueous medium. Pipetting of the aqueous extract into the graphite furnace gives fairly good instrumental reproducibility (2-3% error). Detection limits of about 10 ppM Te for a 0.5-g sample have been achieved with the medium-performance apparatus used. Results for Te in some geochemical reference materials are reported. Indications are given for the determination of Sb and Mo in the same solutions.

  12. Determination of mercury in gold bullion by flame and graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Hinds, Michael W.

    1998-08-01

    A procedure was developed to determine mercury in unrefined gold by flame and graphite furnace atomic absorption spectrometry (FAAS and GFAAS). High acid content (60-80% of concentrated HCl in water) was needed to keep silver (usually present with gold deposits) in solution as a chloro-complex. Although Hg determinations by FAAS and GFAAS have poor sensitivity, the relatively high concentrations of Hg (0.02-0.2%) are well within the capabilities of these techniques. No significant difference was observed between concentration values obtained from these techniques and those obtained by inductively coupled plasma atomic emission spectrometry (ICP-AES) with the same sample. The limit of detection (3 s) was found to be approximately 20 μg g -1 for both GFAAS and FAAS determinations. However, FAAS is the recommended method due to simplicity of operation, higher sample throughput, low cost, and ease of method transfer to other laboratories.

  13. Analysis of lithium in deep basalt groundwaters using graphite furnace atomic absorption spectrophotometry

    SciTech Connect

    Dill, J.A.; Marcy, A.D.

    1986-05-01

    Lithium is under consideration for use as a reactive (sorptive) tracer in experiments designed to provide information regarding natural attenuation processes in a basalt-groundwater environment. In support of these activities, background lithium concentrations in samples obtained from a variety of test horizons have been determined using graphite furnace atomic absorption spectrophotometry. Significant interference was observed in these determinations and was found to be due to the presence of silicate in the samples. It was found that these problems could be circumvented through the use of alkaline silicate or synthetic groundwater matrix modifiers. This matrix effect was examined in some detail. Results obtained using the graphite furnace were compared to results obtained using inductively coupled plasma atomic emission spectroscopy.

  14. [Determination of calcium and magnesium in wheat flour by suspension sampling-flame atomic absorption spectrometry].

    PubMed

    Liu, L; Zhang, Q; Hu, Y

    1999-06-01

    Suspension sampling technique was applied to flame atomic absorption spectrometry and was successfully used to determine calcium and magnesium in wheat flour. The wheat flour was suspended in agar sol containing dibutyl phthalate and made into suspension. Choice of suspension agent and elimination of chemical interference were studied. The test solution was injected into air-acetylene flame to determine calcium and magnesium by standard addition method. Determination results were consistent with those obtained by ashing method. The t-test showed that no difference was found between the two methods. Displacement of ashing method by suspension sampling method for the sample pretreatment is possible. This method is convenient, rapid and accurate.

  15. Iron analysis in atmospheric water samples by atomic absorption spectroscopy (AAS) in water-methanol.

    PubMed

    Sofikitis, A M; Colin, J L; Desboeufs, K V; Losno, R

    2004-01-01

    To distinguish between Fe(II) and Fe(III) species in atmospheric water samples, we have adapted an analytical procedure based on the formation of a specific complex between Fe(II) and ferrozine (FZ) on a chromatographic column. After elution of Fe(III), the Fe(II) complex is recovered with water-methanol (4:1). The possibility of trace iron measurements in this complex medium by graphite-furnace atomic-absorption spectrometry has been investigated. A simplex optimization routine was required to complete the development of the analytical method.

  16. Determination of mercury in sewage sludge by direct slurry sampling graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Baralkiewicz, Danuta; Gramowska, Hanka; Kózka, Małgorzata; Kanecka, Anetta

    2005-03-01

    Ultrasonic slurry sampling electrothermal atomic absorption spectrometry (ETAAS) method was elaborated to the determination of Hg in sewage sludge samples with the use of KMnO 4+Pd modifier. The minimum sample amount required for slurry preparation with respect to sample homogeneity was evaluated by weighting masses between 3 and 30 mg directly into the autosampler cups. Validation of the proposed method was performed with the use of Certified Reference Materials of sewage sludge, CRM 007-040 and CRM 144R. Two sewage sludge samples from Poznañ (Poland) city were analysed using the present direct method and a method with sample digestion, resulting in no difference within statistical error.

  17. Neutral atomic absorption lines and far-UV extinction: Possible implications for depletions and grain parameters

    NASA Astrophysics Data System (ADS)

    Welty, Daniel E.

    1990-07-01

    Researchers examine nine lines of sight within the Galaxy and one in the Large Magellanic Cloud (LMC) for which data on both neutral atomic absorption lines (Snow 1984; White 1986; Welty, Hobbs, and York 1989) and far UV extinction (Bless and Savage 1972; Jenkins, Savage, and Spitzer 1986) are available, in order to test the assumption that variations in gamma/alpha will cancel in taking ratios of the ionization balance equation, and to try to determine to what extent that assumption has affected the aforementioned studies of depletions and grain properties.

  18. Neutral atomic absorption lines and far-UV extinction: Possible implications for depletions and grain parameters

    NASA Technical Reports Server (NTRS)

    Welty, Daniel E.

    1990-01-01

    Researchers examine nine lines of sight within the Galaxy and one in the Large Magellanic Cloud (LMC) for which data on both neutral atomic absorption lines (Snow 1984; White 1986; Welty, Hobbs, and York 1989) and far UV extinction (Bless and Savage 1972; Jenkins, Savage, and Spitzer 1986) are available, in order to test the assumption that variations in gamma/alpha will cancel in taking ratios of the ionization balance equation, and to try to determine to what extent that assumption has affected the aforementioned studies of depletions and grain properties.

  19. Determination of beryllium in urine by graphite furnace atomic absorption spectrophotometry

    SciTech Connect

    Thorat, D.D.; Bhat, P.N.; Mahadevan, T.N.

    1995-08-01

    A method for the determination of beryllium in urine samples by Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS) has been developed. The background correction problem due to the sample matrix was overcome by solvent extraction step. Urine samples were digested with a mixture of concentrated nitric and sulphuric acids. Beryllium in solution was complexed with acetylacetone, extracted in chloroform at pH 8.5 and back extracted in 2%(v/v) nitric acid for final analysis by AAS. The range of concentrations of beryllium observed in urine samples covering both occupational and control subject was 0.03 - 0.37 ng Be/ml.

  20. Refraction and absorption of x rays by laser-dressed atoms.

    SciTech Connect

    Buth, C.; Santra, R.; Young, L.

    2010-06-01

    X-ray refraction and absorption by neon atoms under the influence of an 800 nm laser with an intensity of 10{sup 13} W/cm{sup 2} is investigated. For this purpose, we use an ab initio theory suitable for optical strong-field problems. Its results are interpreted in terms of a three-level model. On the Ne 1s {yields} 3p resonance, we find electromagnetically induced transparency (EIT) for x rays. Our work opens novel perspectives for ultrafast x-ray pulse shaping.

  1. Determination of traces of silver in waters by anion exchange and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Fishman, M. J.; Ball, J.W.

    1969-01-01

    A method has been developed for the accurate determination of 0.1-1 ??g of silver per liter of water. The method permits stabilization of silver in water without loss to container walls. Optimum conditions have been established for the complete recovery of silver from water with an anion-exchange column, for quantitative elution of silver from the resin, and for measurement of silver by atomic absorption spectrophotometry after chelation with ammonium pyrrolidine dithiocarbamate and extraction of the chelate with MIBK. Silver in the 1-10 ??g 1 range can be determined by extraction without pre-concentration on an ion-exchange resin. ?? 1969.

  2. Automated atomic absorption spectrometric determination of total arsenic in water and streambed materials

    USGS Publications Warehouse

    Fishman, M.

    1977-01-01

    An automated method to determine both inorganic and organic forms of arsenic In water, water-suspended mixtures, and streambed materials Is described. Organic arsenic-containing compounds are decomposed by either ultraviolet radiation or by suHurlc acid-potassium persulfate digestion. The arsenic liberated, with Inorganic arsenic originally present, is reduced to arsine with sodium borohydrlde. The arable Is stripped from the solution with the aid of nitrogen and Is then decomposed In a tube furnace heated to 800 ??C which Is placed in the optical path of an atomic absorption spectrometer. Thirty samples per hour can be analyzed to levels of 1 ??g arsenic per liter.

  3. Determination of heavy metals in solid emission and immission samples using atomic absorption spectroscopy

    SciTech Connect

    Fara, M.; Novak, F.

    1995-12-01

    Both flame and electrothermal methods of atomic absorption spectroscopy (AAS) have been applied to the determination of Al, As, Be, Ca, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, TI, Se, V and Zn in emission and emission (deposition) samples decomposed in open PTFE test-tubes by individual fuming-off hydrofluoric, perchloroic and nitric acid. An alternative hydride technique was also used for As and Se determination and Hg was determined using a self-contained AAS analyzer. A graphite platform proved good to overcome non-spectral interferences in AAS-ETA. Methods developed were verified by reference materials (inc. NBS 1633a).

  4. Estimation of calcium and magnesium in serum and urine by atomic absorption spectrophotometry

    PubMed Central

    Thin, Christian G.; Thomson, Patricia A.

    1967-01-01

    A method has been described for the estimation of calcium and magnesium in serum and urine using atomic absorption spectrophotometry. The precision and accuracy of the techniques have been determined and were found to be acceptable. The range of values for calcium and magnesium in the sera of normal adults was found to be: serum calcium (corrected to a specific gravity of 1·026) 8·38-10·08 mg. per 100 ml.; serum magnesium 1·83-2·43 mg. per 100 ml. PMID:5602562

  5. Quantification of aortic valve calcification using multislice spiral computed tomography: comparison with atomic absorption spectroscopy.

    PubMed

    Koos, Ralf; Mahnken, Andreas Horst; Kühl, Harald Peter; Mühlenbruch, Georg; Mevissen, Vera; Stork, Ludwig; Dronskowski, Richard; Langebartels, Georg; Autschbach, Rüdiger; Ortlepp, Jan R

    2006-05-01

    Multislice spiral computed tomography (MSCT) allows the in vivo detection of valvular calcification. The aim of this study was to validate the quantification of aortic valve calcification (AVC) by MSCT with in vitro measurements by atomic absorption spectroscopy. In 18 patients with severe aortic stenosis, 16 detector row MSCT (SOMATOM Sensation 16, Siemens, Forchheim, Germany with scan parameters as follows: 420 milliseconds tube rotation time, 12 x 0.75 mm collimation, tube voltage 120 KV) was performed before aortic valve replacement. Images were reconstructed at 60% of the RR interval with an effective slice thickness of 3 mm and a reconstruction increment of 2 mm. AVC was assessed using Agatston AVC score, mass AVC score, and volumetric AVC score. After valve replacement, the calcium content of the excised human stenotic aortic valves was determined in vitro using atomic absorption spectroscopy. The mean Agatston AVC score was 3,842 +/- 1,790, the mean volumetric AVC score was 3,061 +/- 1,406, and mass AVC score was 888 +/- 492 as quantified by MSCT. Atomic absorption spectroscopy showed a mean true calcification mass (Ca5(PO4)3OH) of 19 +/- 8 mass%. There was a significant correlation between in vivo AVC scores determined by MSCT and in vitro mean true calcification mass (r = 0.74, P = 0.0004 for mass AVC score, r = 0.79, P = 0.0001 for volumetric AVC score and r = 0.80, P = 0.0001 for Agatston AVC score) determined by atomic absorption spectroscopy. Linear regression analysis showed a significant association between the degree of hydroxyapatite (given in mass%) in the aortic valve and the degree of AVC (R = 0.74, F = 19.6, P = 0.0004 for mass AVC score, R = 0.80, F = 29.3, P = 0.0001 for Agatston AVC score and R = 0.79, F = 27.3, P = 0.0001 for volumetric AVC score) assessed by MSCT. MSCT allows accurate in vivo quantification of aortic valve calcifications.

  6. Mercury speciation in environmental solid samples using thermal release technique with atomic absorption detection.

    PubMed

    Shuvaeva, Olga V; Gustaytis, Maria A; Anoshin, Gennadii N

    2008-07-28

    A sensitive and very simple method for determination of mercury species in solid samples has been developed involving thermal release analysis in combination with atomic absorption (AAS) detection. The method allows determination of mercury(II) chloride, methylmercury and mercury sulfide at the level of 0.70, 0.35 and 0.20ng with a reproducibility of the results of 14, 25 and 18%, respectively. The accuracy of the developed assay has been estimated using certified reference materials and by comparison of the results with those of an independent method. The method has been applied for Hg species determination in original samples of lake sediments and plankton.

  7. [Electrothermal atomic absorption determination of arsenic in plants and plant products].

    PubMed

    Karpova, E A; Malysheva, A G; Ermakov, A A; Sidorenkova, N K

    2012-01-01

    The authors have developed the optimal temperature-time parameters of electrothermal atomic absorption determination of arsenic in plants after their acid predigestion. The matrix modifier is 1% nickel nitrate or palladium nitrate solution. Cuvettes (ovens) are simple, made of porous or pyrolytic graphite. The analytical program is suitable for both spectrometers with Zeeman and deuterium background correction. The correctness of the procedure has been estimated from the results of analysis of state reference samples certified for their arsenic content. The coefficient of variation was 20-35% for the concentration range of 0.02-0.2 mg/kg.

  8. The determination of aluminum, copper, iron, and lead in glycol formulations by atomic absorption spectroscopy

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Initial screening tests and the results obtained in developing procedures to determine Al, Cu, Fe, and Pb in glycol formulations are described. Atomic absorption completion was selected for Cu, Fe and Pb, and after comparison with emission spectroscopy, was selected for Al also. Before completion, carbon, iron, and lead are extracted with diethyl dithio carbamate (DDC) into methyl isobutyl ketone (MIBK). Aluminum was also extracted into MIBK using 8-hydroxyquinoline as a chelating agent. As little as 0.02 mg/l carbon and 0.06 mg/l lead or iron may be determined in glycol formulations. As little as 0.3 mg/l aluminum may be determined.

  9. Method for the determination of cobalt from biological products with graphite furnace atomic absorption spectrometer

    NASA Astrophysics Data System (ADS)

    Zamfir, Oana-Liliana; Ionicǎ, Mihai; Caragea, Genica; Radu, Simona; Vlǎdescu, Marian

    2016-12-01

    Cobalt is a chemical element with symbol Co and atomic number 27 and atomic weight 58.93. 59 Co is the only stable cobalt isotope and the only isotope to exist naturally on Earth. Cobalt is the active center of coenzymes called cobalamin or cyanocobalamin the most common example of which is vitamin B12. Vitamin B12 deficiency can potentially cause severe and irreversible damage, especially to the brain and nervous system in the form of fatigue, depression and poor memory or even mania and psychosis. In order to study the degree of deficiency of the population with Co or the correctness of treatment with vitamin B12, a modern optoelectronic method for the determination of metals and metalloids from biological samples has been developed, Graphite Furnace - Atomic Absorption Spectrometer (GF- AAS) method is recommended. The technique is based on the fact that free atoms will absorb light at wavelengths characteristic of the element of interest. Free atoms of the chemical element can be produced from samples by the application of high temperatures. The system GF-AAS Varian used as biological samples, blood or urine that followed the digest of the organic matrix. For the investigations was used a high - performance GF-AAS with D2 - background correction system and a transversely heated graphite atomizer. As result of the use of the method are presented the concentration of Co in the blood or urine of a group of patient in Bucharest. The method is sensitive, reproducible relatively easy to apply, with a moderately costs.

  10. Determination of Copper by Graphite Furnace Atomic Absorption Spectrophotometry: A Student Exercise in Instrumental Methods of Analysis.

    ERIC Educational Resources Information Center

    Williamson, Mark A.

    1989-01-01

    Discusses a student exercise which requires the optimizing of the charring and atomization temperatures by producing a plot of absorbance versus temperature for each temperature parameter. Notes that although the graphite furnace atomic absorption spectroscopy technique has widespread industrial use, there are no published, structured experiments…

  11. Determination of Copper by Graphite Furnace Atomic Absorption Spectrophotometry: A Student Exercise in Instrumental Methods of Analysis.

    ERIC Educational Resources Information Center

    Williamson, Mark A.

    1989-01-01

    Discusses a student exercise which requires the optimizing of the charring and atomization temperatures by producing a plot of absorbance versus temperature for each temperature parameter. Notes that although the graphite furnace atomic absorption spectroscopy technique has widespread industrial use, there are no published, structured experiments…

  12. COMPARISON OF FEMTOSECOND AND NANOSECOND TWO PHOTON ABSORPTION LASER INDUCED FLUORESCENCE (TALIF) OF ATOMIC OXYGEN IN ATMOSPHERIC PRESSURE PLASMAS

    DTIC Science & Technology

    2016-08-01

    AFRL-RQ-WP-TR-2016-0118 COMPARISON OF FEMTOSECOND- AND NANOSECOND-TWO-PHOTON-ABSORPTION LASER- INDUCED FLUORESCENCE (TALIF) OF ATOMIC ...LASER-INDUCED FLUORESCENCE (TALIF) OF ATOMIC OXYGEN IN ATMOSPHERIC PRESSURE PLASMAS 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM...copyright protection in the United States. 14. ABSTRACT Absolute number densities of atomic species produced by nanosecond duration, repetitively

  13. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of some fluoroquinolone antibacterials using ammonium reineckate

    NASA Astrophysics Data System (ADS)

    Al-Ghannam, Sheikha M.

    2008-04-01

    Three accurate, rapid and simple atomic absorption spectrometric (AAS), conductometric and colorimetric methods were developed for the determination of gatifloxacin (GTF), moxifloxacin (MXF) and sparfloxacin (SPF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone. The optimizations of various experimental conditions were described. Optimum concentration ranges for the determination of GTF, MXF and SPF were 5.0-150, 40-440 μg mL -1 and 0.10-1.5 mg mL -1 using atomic absorption (AAS), conductometric and colorimetric methods, respectively. Detection and quantification limits are ranges from 1.5 to 2.3 μg mL -1 using AAS method or 30-45 μg mL -1 using colorimetric method. The proposed procedures have been applied successfully to the analysis of these drugs in pharmaceutical formulations and the results are favourably comparable to the reference methods.

  14. Determination of sodium and potassium in nanoliter volumes of biological fluids by furnace atomic absorption spectrometry

    SciTech Connect

    Nash, L.A.; Peterson, L.N.; Nadler, S.P.; Levine, D.Z.

    1988-11-01

    Renal tubular fluid samples are nanoliter (10/sup -9/ L) volumes containing sodium and potassium concentrations that are within the range of determination by furnace atomic absorption. Modification of nanoliter handling techniques and the use of microboats with the IL 951/655 provided a method for rapid precise analyses (relative standard deviation of 5%). Determinations of sodium and potassium were precise; however, inaccuracies occurred with anion substitution of sodium salts. NaHCO/sub 3/ solutions gave consistently higher peak height absorbance and area absorbance compared with those of NaCl: the peak area absorbance correlated linearly with the concentration of bicarbonate. Pretreatment of the microboat with boric acid eliminated this phenomenon and the associated inaccuracy. Comparison of determination of sodium in nanoliter samples by graphite furnace atomic absorption with macroanalysis by flame emission gave relative errors of less than 2.0%. Addition of sodium and potassium to tubular fluid samples yielded mean recoveries of 102.6% and 99.7%, respectively. The authors conclude that graphite furnace can be an accurate method for measurement of sodium and potassium in nanoliter volumes of biological fluids.

  15. Use of flameless atomic absorption spectroscopy in immune cytolysis for nonradioactive determination of killer cell activity.

    PubMed

    Borella, P; Bargellini, A; Salvioli, S; Cossarizza, A

    1996-02-01

    We describe here a novel method to evaluate natural killer (NK) cytolytic activity by use of flameless atomic absorption spectroscopy (GF-AAS). This technique may be adopted for use in laboratories equipped with electrothermal atomic absorption spectrometers. Nonradioactive Cr as Na2CrO4 was used to label target cells (K562), and cell lysis was evaluated by measuring Cr released after 4 h of incubation with the effectors. We selected 520 micrograms/L as the optimal dose for labeling targets, between 12 and 20 h as the optimal incubation time, and 10(4) cells as the optimal target size. Advantages of this method include: (a) exclusion of radioactive tracer, with no risk for workers; (b) limited costs; (c) high sensitivity and reproducibility; (d) possibility to store samples; and (e) better control of Cr used for labeling cells due to well-determined, fixed Cr concentrations in the range of nontoxic and linear cellular uptake. Comparison with data obtained by conventional 51Cr labeling of targets killed by the same effectors was excellent, yielding comparable results and corroborating the method.

  16. Quantitation of a novel metalloporphyrin drug in plasma by atomic absorption spectroscopy.

    PubMed

    Hoffman, K L; Feng, M R; Rossi, D T

    1999-03-01

    A bioanalytical method to quantify cobalt mesoporphyrin (CoMP), a novel therapeutic agent, in plasma has been developed and validated. The approach involves atomic absorption spectroscopy to determine total cobalt in a sample and a back-calculation of the amount of compound present. Endogenous plasma cobalt concentrations were small ( <0.2 ng/ml(-1) Co in rat plasma) in comparison to the quantitation limit (4.5 ng/ml(-1) Co). The inter-day imprecision of the method was 10.0% relative standard deviation (RSD) and the inter-day bias was +/- 8.0% relative error (RE) over a standard curve range of 4.5- 45.0 ng/ml(-1) Co. Because it quantifies total cobalt, the method cannot differentiate between parent drug and metabolites, but negligible metabolism allows reliable estimates of the actual parent drug concentration. A correlation study between the atomic absorption method and 14C-radiometry demonstrated excellent agreement (r = 0.9868, slope = 1.041 +/- 0.028, intercept = 223.7 +/- 190.0) and further substantiated the accuracy of the methods. Methodology was successfully applied to a pharmacokinetic study of CoMP in rat, with pharmacokinetic parameter estimation. The elimination half-lives, after intra-muscular and subcutaneous administration, were 7.7 and 8.8 days, respectively.

  17. Determination of metal concentration in fat supplements for swine nutrition by atomic absorption spectroscopy.

    PubMed

    Cocchi, Marina; Faeti, Valerio; Manfredini, Matteo; Manzini, Daniela; Marchetti, Andrea; Sighinolfi, Simona

    2005-01-01

    The presence of some essential and toxic metals in fat supplements for swine diet was investigated. Collected samples represented a relevant production of the Italian industry. In particular, some samples were enriched with antioxidants or waste cooking oils. The method for the determination of Ca, Cu, Cd, Fe, Mg, Mn, Ni, Pb, and Zn in fat samples was developed by means of a certified reference material (CRM 186) and a representative fatty sample (RFS). All samples were digested in closed vessels in a microwave oven and then analyzed by flame atomic absorption or graphite furnace atomic absorption spectrometry. The entire analytical method provided a satisfactory repeatability and reproducibility confirmed by agreement between the experimental recovery data obtained for the CRM 186 sample and, with the method of standard additions, for the RFS material. The samples generally showed a small amount of metals compared with the recommended daily intake for the essential elements. On the other hand, some samples contained a significant concentration, from an analytical point of view, of Cd, Ni, and Pb. Principal component analysis (PCA) was applied to inspect the experimental data obtained from samples analysis. Basically no differences were detected in terms of metal concentration among the fat supplements analyzed.

  18. Graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware: Collaborative Study.

    PubMed

    Hight, S C

    2000-01-01

    A modification of the official flame atomic absorption spectrometric (FAAS) method for determining lead and cadmium extracted from ceramic foodware was collaboratively studied. In the modified method, graphite furnace atomic absorption spectrometry (GFAAS) is substituted for FAAS. The modified method also includes mandatory quality control procedures to improve method performance. The extraction procedure of the official method (leaching with 4% acetic acid for 24 h at room temperature) remains unchanged. Seven laboratories analyzed blind duplicate portions of 3 ceramicware leach solutions containing Pb at concentrations of 0.0196, 0.403, and 3.73 microg/mL and Cd at concentrations of 0.00236, 0.0456, and 0.544 microg/mL. Performance of the modified method compared well with that of the official method. The repeatability relative standard deviation (RSDr) ranged from 0.87 to 6.7% for Pb and from 3.7 to 11% for Cd. The reproducibility relative standard deviation (RSDR) ranged from 4.5 to 12% for Pb and from 7.0 to 11% for Cd. Accuracy of collaborator results was 97-98% for Pb and 93-101% for Cd. Quality control results and quantitation limits were excellent. Method quantitation limits varied among laboratories from 0.005 to 0.019 microg/mL for Pb and from 0.0004 to 0.0019 microg/mL for Cd. The modified method was adopted First Action by AOAC INTERNATIONAL.

  19. [The application of atomic absorption spectrometry in automatic transmission fault detection].

    PubMed

    Chen, Li-dan; Chen, Kai-kao

    2012-01-01

    The authors studied the innovative applications of atomic absorption spectrometry in the automatic transmission fault detection. After the authors have determined Fe, Cu and Cr contents in the five groups of Audi A6 main metal in automatic transmission fluid whose travel course is respectively 10-15 thousand kilometers, 20-26 thousand kilometers, 32-38 thousand kilometers, 43-49 thousand kilometers, and 52-58 thousand kilometers by atomic absorption spectrometry, the authors founded the database of primary metal content in the Audi A6 different mileage automatic transmission fluid (ATF). The research discovered that the main metal content in the automatic transmission fluid increased with the vehicles mileage and its normal metal content level in the automatic transmission fluid is between the two trend lines. The authors determined the main metal content of automatic transmission fluid which had faulty symptoms and compared it with its database value. Those can not only judge the wear condition of the automatic transmission which had faulty symptoms but also help the automobile detection and maintenance personnel to diagnose automatic transmission failure reasons without disintegration. This reduced automobile maintenance costs, and improved the quality of automobile maintenance.

  20. Measurement of urinary mercury excretion by atomic absorption in health and disease

    PubMed Central

    Taylor, Andrew; Marks, Vincent

    1973-01-01

    Taylor, A., and Marks, V. (1973).British Journal of Industrial Medicine,30, 293-296. Measurement of urinary excretion by atomic absorption in health and disease. Excretion of mercury was measured by a cold-vapour atomic absorption technique on samples of urine from five groups of people having varying exposure to mercury. Serial investigations of up to 14 days were carried out on eight subjects to determine the temporal relationship between exposure and excretion. Subjects with no exposure excreted 0-10 μg mercury per gramme creatinine. Similar values were found in laboratory staff and men assembling hollow cathode lamps. Excretion of mercury by dental workers was significantly increased. No correlation between exposure and excretion of mercury was seen in the subjects investigated. The significance of measuring urinary excretion in the detection of mercury intoxication is discussed. The suggestion is made that urinary mercury excretion of more than 20 μg/g creatinine or 40 μg mercury per 24 hours should be considered evidence of recent or remote exposure to mercury. It is concluded that measurement of urinary mercury excretion is important in revealing those persons who may ultimately develop symptoms of toxicity. PMID:4723792

  1. Multi-element analysis of manganese nodules by atomic absorption spectrometry without chemical separation

    USGS Publications Warehouse

    Kane, J.S.; Harnly, J.M.

    1982-01-01

    Five manganese nodules, including the USGS reference nodules A-1 and P-1, were analyzed for Co, Cu, Fe, K, Mg, Mn, Na, Ni and Zn without prior chemical separation by using a simultaneous multi-element atomic absorption spectrometer with an air-cetylene flame. The nodules were prepared in three digestion matrices. One of these solutions was measured using sixteen different combinations of burner height and air/acetylene ratios. Results for A-1 and P-1 are compared to recommended values and results for all nodules are compared to those obtained with an inductively coupled plasma. The elements Co, Cu, Fe, K, Mg, Mn, Na, Ni, and Zn are simultaneously determined with a composite recovery for all elements of 100 ?? 7%, independent of the digestion matrices, heights in the flame, or flame stoichiometries examined. Individual recoveries for Co, K, and Ni are considerably poorer in two digests than this composite figure, however. The optimum individual recoveries of 100 ?? 5% and imprecisions of 1-4%, except for zinc, are obtained when Co, K, Mn, Na and Ni are determined simultaneously in a concentrated digest, and in another analytical sequence, when Cu, Fe, Mg, Mn and Zn are measured simultaneously after dilution. Determination of manganese is equally accurate in the two sequences; its measurement in both assures internal consistency between the two measurement sequences. This approach improves analytical efficiency over that for conventional atomic absorption methods, while minimizing loss of accuracy or precision for individual elements. ?? 1982.

  2. [Ten element contents and their distribution in fruits determinated by atomic absorption spectrometry].

    PubMed

    Cai, Yanrong; Liu, Yuan; Li, Lingling; Wang, Wei

    2011-05-01

    To investigate the contents and distributions of the Zn, Cu, K, Ca, Mg, Mn, Pb, Cd, Cr and Se elements in the fruits. The fruit samples were digested with wet method. Contents of zinc,copper, calcium,magnesium,potassium and manganese were determined by flame atomic absorption spectrometry (FAAS). Contents of lead, cadmium, chromium and selenium were determined by graphite furnace atomic absorption spectrometry (GFAAS). There existed differences for the element distribution in each part of the fruits. The contents of lead in the grapes, dried jujubes and papaya were close to the pollutant concentration limits, but their contents were lower than standard limits. The contents of chromium in the Guoguang apples, pears, dry jujubes and cherry tomatoes were higher than standard limits. Selenium was detected in the Guoguang apples, bananas, pears, dry jujubes, papaya and pomelo. The contents of copper in the grapes and dry jujubes exceeded standard limits. The contents of zinc were lower than standard limits. The calcium contents were the highest in the papaya. The contents of magnesium and manganese were the highest in the dry jujubes. The contents of potassium were higher in the dry jujubes, pomelo and cherry tomato. The highest levels of the elements were in the seeds,and the second levels were in the skin,the lowest levels were in the pulp. The element contents of the peel were higher than those the pulp.

  3. Polarisation response of delay dependent absorption modulation in strong field dressed helium atoms probed near threshold

    NASA Astrophysics Data System (ADS)

    Simpson, E. R.; Sanchez-Gonzalez, A.; Austin, D. R.; Diveki, Z.; Hutchinson, S. E. E.; Siegel, T.; Ruberti, M.; Averbukh, V.; Miseikis, L.; Strüber, C. S.; Chipperfield, L.; Marangos, J. P.

    2016-08-01

    We present the first measurement of the vectorial response of strongly dressed helium atoms probed by an attosecond pulse train (APT) polarised either parallel or perpendicular to the dressing field polarisation. The transient absorption is probed as a function of delay between the APT and the linearly polarised 800 nm field of peak intensity 1.3× {10}14 {{W}} {{cm}}-2. The APT spans the photon energy range 16-42 eV, covering the first ionisation energy of helium (24.59 eV). With parallel polarised dressing and probing fields, we observe modulations with periods of one half and one quarter of the dressing field period. When the polarisation of the dressing field is altered from parallel to perpendicular with respect to the APT polarisation we observe a large suppression in the modulation depth of the above ionisation threshold absorption. In addition to this we present the intensity dependence of the harmonic modulation depth as a function of delay between the dressing and probe fields, with dressing field peak intensities ranging from 2 × 1012 to 2 × 1014 {{W}} {{cm}}-2. We compare our experimental results with a full-dimensional solution of the single-atom time-dependent (TD) Schrödinger equation obtained using the recently developed abinitio TD B-spline ADC method and find good qualitative agreement for the above threshold harmonics.

  4. [Studies on cold resistance of hazel determined and analyzed by atomic absorption spectrometry].

    PubMed

    Li, Xiu-Xia; Liu, Cheng-Cai; Zhang, Wei-Dong; Shao, Hong; Wu, Heng-Mei; Wang, Zhong; Yang, Yong-Nian; Li, Ji-Lin

    2010-06-01

    Using annual branch of hazel as the experimental materials, the K(+)-leakage and relative electric conductivity of three hazel species (six hazel clones) which had been treated with different low temperature were determined by electro-conductivity gauge and atomic absorption spectrometry. Regression models were established for low temperature to the K(+)-leakage or the relative electric conductivity of six hazel clones. The results showed that there was the same result of cold resistance for all clones using the two methods of comprehensive evaluation, and the indicator of K(+)-leakage rate determined by atomic absorption spectrometry can be used as a means of early identification of cold resistance of hazel clones. There were obvious differences among the clones in the ability of cold resistance. The order of the ability of cold resistance for the six hazel clones was C7R7 > Z-9-40 > C6R1 > CS2R1 > Z-9-22 > Z-9-30, and the order of the ability of cold resistance for the three hazel species was C. heterophylla > C. heterophyllax X (C. heterophylla X C. avellana) > C. heterophylla X C. avellana. The median lethal temperature of tissue for all clones is -26(-)-40 degrees "C.

  5. [Determination of indium in whole blood by graphite furnace atomic absorption spectrometry].

    PubMed

    He, Juntao; Liu, Fen; Xiang, Yingping; Li, Zhimin

    2015-08-01

    To investigate the sensitization effect of different chemical modifiers in the determination of indium in whole blood by graphite furnace atomic absorption spectrometry, and to develop a new method for the determination of indium in whole blood. A mixture of 0.3% HNO3 (V/V) + 0.1% Triton X-100 (V/V) was used as a diluent, and a solution of 1 000 µg/ml Pd (NO3)2 + 3 000 µg/ml Mg (NO3)2 was used as modifier. After being diluted five times, the concentration of indium of the blood was directly determined by graphite furnace atomic absorption spectrometry. The detection limit of the method was 0.33 µg/L, the linear range was 0.33~100.00 µg/L, the relative standard deviation was 1.43%~2.65%, and the recovery rate was 98.3%~105.3%. The method is simple and fast and has high recovery and precision, and it is suitable for the determination of indium in whole blood.

  6. Evaluation of the Randox colorimetric serum copper and zinc assays against atomic absorption spectroscopy.

    PubMed

    Beckett, Jeffrey M; Hartley, Thomas F; Ball, Madeleine J

    2009-07-01

    Analysis of copper and zinc in serum is commonly performed using atomic absorption spectrometry (AAS); however, these methods are often not readily available in smaller laboratories. Randox colorimetric assays for copper and zinc in serum were evaluated on the Thermo Electron Data Pro analyser against flame AAS methods. Copper and zinc were measured in 48 serum samples using the Randox colorimetric copper (CU2340) and zinc (ZN2341) assays on the Data Pro analyser and the results compared with those from a Varian Spectra 880 atomic absorption spectrometer. A smaller set of samples (n = 15) were also analysed colorimetrically for zinc on the Roche Cobas Mira. Linear regression analyses of Bland and Altman plots from the Data Pro - AAS comparison gave the following results for copper: correlation r = 0.6669 (P < 0.01), slope = -0.2499 (P < 0.01), intercept = 3.219 (P < 0.01). For zinc, results were as follows: correlation r = 0.1976, slope = 0.1807, intercept = -1.922. For the smaller set of samples, the Cobas Mira - AAS comparison for zinc gave correlation r = 0.4379, slope = 0.5294, intercept = -4.074. The results indicated significant systematic and fixed bias between the colorimetric copper and the AAS method. Performances in comparison to AAS methods indicated the colorimetric methods, as used, are unsuitable for the accurate determination of copper and zinc in human serum.

  7. Indirect atomic absorption spectrometric determination of sulfate in human blood serum.

    PubMed

    Chattaraj, S; Das, A K

    1992-03-01

    An indirect method for the determination of sulfate by atomic absorption spectrometry (AAS) is described. Sulfate forms a stable ion-association complex, [Cu(neocuproine)2]2+(SO4(2-)), in neutral medium, which can be extracted into isobutyl methyl ketone in the presence of a polar medium (methanol) with an efficiency higher than 98.0% and the extract can be analysed directly for copper (and hence indirectly for sulfate) by AAS. Measurement of the copper atomic absorption signal from the organic phase allows the indirect determination of 0.14-1.12 micrograms ml-1 of sulfate, giving a 450-fold increase in sensitivity over the conventional method of precipitation with barium. The limit of detection (3 sigma) is 3.2 ng ml-1 which is better than that of ion chromatography (0.15 micrograms ml-1). Indirect AAS allows the accurate assay of inorganic sulfate anion in biological fluids and tissues. The sulfate concentration determined by the proposed method in human blood serum (n = 6 in each instance) was 35.4-43.3 micrograms ml-1 in normal persons, 50.3-62.5 micrograms ml-1 in jaundice patients and 83.3-155.6 micrograms ml-1 in diabetic patients. A good correlation between measured sulfate and the sulfate added to blood serum was obtained.

  8. Electrochemical modification of a graphite platform for a solid sampling electrothermal atomic absorption spectrometry of mercury.

    PubMed

    Cervenka, Rostislav; Zelinková, Hana; Konecná, Marie; Komárek, Josef

    2010-01-01

    An electrodeposited palladium and iridium/gold mixture has been investigated as a chemical modifier for mercury determination in environmental samples by solid sampling electrothermal atomic absorption spectrometry. Electrochemical procedures of platform surface modification performed in a cell with 20 ml of solution, and in a drop of modifier solution have been optimized. Simple electrolysis in a drop was found to be the most consistent, taking the reproducibility as the major criterion. A total mass of 250 µg of electrodeposited palladium or an iridium/gold mixture was used. The lifetime of 60 - 70 firings for a deposited iridium/gold mixture was smaller than that for palladium with a lifetime of 100 - 120 firings. The detection limit was 120 pg Hg. Different sample masses of between 0.1 and 10 mg were weighed into modified platforms according to the mercury content. The results obtained for mercury in environmental samples as soils, sediments and plant, using solid sampling and calibration against aqueous standards stabilized by potassium permanganate, were in good agreement with those achieved by using the thermal deposition of modifiers and with measurements by pyrolysis atomic absorption spectrometry with gold amalgamation.

  9. Shock-tube measurements of excited oxygen atoms using cavity-enhanced absorption spectroscopy.

    PubMed

    Nations, Marcel; Wang, Shengkai; Goldenstein, Christopher S; Sun, Kai; Davidson, David F; Jeffries, Jay B; Hanson, Ronald K

    2015-10-10

    We report the use of cavity-enhanced absorption spectroscopy (CEAS) using two distributed feedback diode lasers near 777.2 and 844.6 nm for sensitive, time-resolved, in situ measurements of excited-state populations of atomic oxygen in a shock tube. Here, a 1% O2/Ar mixture was shock-heated to 5400-8000 K behind reflected shock waves. The combined use of a low-finesse cavity, fast wavelength scanning of the lasers, and an off-axis alignment enabled measurements with 10 μs time response and low cavity noise. The CEAS absorption gain factors of 104 and 142 for the P35←S520 (777.2 nm) and P0,1,23←S310 (844.6 nm) atomic oxygen transitions, respectively, significantly improved the detection sensitivity over conventional single-pass measurements. This work demonstrates the potential of using CEAS to improve shock-tube studies of nonequilibrium electronic-excitation processes at high temperatures.

  10. Direct determination of lead in sweet fruit-flavored powder drinks by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Lima, Éder C.; Krug, Francisco José; Arruda, Marco A. Z.

    1998-04-01

    A simplified method for direct determination of lead in sweet fruit-flavored powder drinks, syrups and honeys by electrothermal atomic absorption spectrometry without sample digestion is proposed. Samples were dissolved in water, acidified to 0.2% (v/v) HNO 3, and directly injected into an end-capped transversely heated graphite atomizer (THGA). Building up of carbonaceous residue inside the atomizer was effectively precluded for sugar solutions not exceeding 8.0% (m/v) when a heating program with two pyrolysis steps (600 and 1000°C) was carried out without air-ashing. Under these conditions one atomizer supported about 250 firings. Among various chemical modifiers tested, better recovery and repeatability results were obtained with a 5 μg Pd + 3 μg Mg(NO 3) 2 mixture. Tests carried out with individual concomitants containing up to 1.0 μg Na, K, Ca or Cl, and up to 10.0 μg phosphate or sulphate, and several mixtures of these six concomitants, did not reveal significant interferences on lead atomization. Characteristic mass and detection limit based on integrated absorbance were 15 and 11 pg Pb, respectively. The relative standard deviation based on 10 measurements for typical samples (20-60 ng g -1 Pb) was always lower than 5.5%. The detection limit of 7.0 ng g -1 Pb attained the Codex recommendation for the maximum allowed lead contents in the sugar samples. Application of t-test to the results obtained by the proposed direct analysis, and the official method adopted by Food Chemical Codex, demonstrated that there were no significant differences at the 5% probability level.

  11. Pressure broadening of atomic oxygen two-photon absorption laser induced fluorescence

    NASA Astrophysics Data System (ADS)

    Marinov, Daniil; Drag, Cyril; Blondel, Christophe; Guaitella, Olivier; Golda, Judith; Klarenaar, Bart; Engeln, Richard; Schulz-von der Gathen, Volker; Booth, Jean-Paul

    2016-12-01

    Atomic oxygen, considered to be a determining reactant in plasma applications at ambient pressure, is routinely detected by two-photon absorption laser induced fluorescence (TALIF). Here, pressure broadening of the (2p 4 3 P 2  →  3p 3 P J=0,1,2) two-photon transition in oxygen atoms was investigated using a high-resolution TALIF technique in normal and Doppler-free configurations. The pressure broadening coefficients determined were {γ{{\\text{O}2}}}   =  0.40  ±  0.08  cm-1/bar for oxygen molecules and {γ\\text{He}}   =  0.46  ±  0.03 cm-1/bar for helium atoms. These correspond to pressure broadening rate constants k\\text{PB}{{\\text{O}2}}   =  9 · 10-9 cm3 s-1 and k\\text{PB}\\text{He}   =  4 · 10-9 cm3 s-1, respectively. The well-known quenching rate constants of O(3p 3 P J ) by O2 and He are at least one order of magnitude smaller, which signifies that non-quenching collisions constitute the main line-broadening mechanism. In addition to providing new insights into collisional processes of oxygen atoms in electronically excited 3p 3 P J state, reported pressure broadening parameters are important for quantification of oxygen TALIF line profiles when both collisional and Doppler broadening mechanisms are important. Thus, the Doppler component (and hence the temperature of oxygen atoms) can be accurately determined from high resolution TALIF measurements in a broad range of conditions.

  12. Atomic oxygen adsorption and absorption on Rh(111) and Ag(111)

    NASA Astrophysics Data System (ADS)

    Derouin, Jonathan D.

    A central question in the field of heterogeneous catalysis is how surface structure and subsurface species influence catalytic behavior. One key to answering that question is determining which surface structures and subsurface species are present under catalytically relevant conditions. This dissertation presents results of Auger electron spectroscopy, low energy electron diffraction, temperature programmed desorption, and scanning tunneling microscopy experiments on oxidized Rh(111) and Ag(111) crystals. Exposing Rh(111) to O2 produced a predominately (2 x 1) adlayer, but even after extended dosing, (2 x 2) domains were also present. Exposing Rh(111) to atomic oxygen yielded O coverages greater than 0.5 ML and (1 x 1) domains were observed to form along terrace step edges. However, (2 x 1) and (2 x 2) domains were still present. Atomic oxygen was used to oxidize Ag(111) in order to study the effect of sample temperature as well as oxygen flux and energy. When atomic oxygen was generated using a lower temperature thermal cracker, a variety of previously reported surface structures were observed. When O was generated using a higher filament temperature, the surface became highly corrugated, layers of Ag 2O appeared to form, and little subsurface oxygen was observed. To investigate the role of sample temperature, the Ag(111) sample was held at various temperatures while being exposed to atomic oxygen. For short doses, sample temperature had minimal effect on surface reconstruction. For longer doses, changes in sample temperature in the range of 490 K to 525 K had a substantial impact on surface reconstruction and subsurface oxygen absorption. Higher temperature dosing yielded the same surface structures which were observed after short doses. Lower temperature dosing with atomic oxygen resulted in subsurface oxygen formation and new structures which covered the surface. The results indicate the rich complexity of oxygen/transition metal interactions and illustrate how

  13. Rhodium as permanent modifier for atomization of lead from biological fluids using tungsten filament electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Zhou, Ying; Parsons, Patrick J.; Aldous, Kenneth M.; Brockman, Paul; Slavin, Walter

    2002-04-01

    Rhodium (Rh) was investigated as a permanent modifier for the atomization of Pb from biological fluids in W-filament atomic absorption spectrometry (AAS). Heating the W-filament with a Rh solution provided a protective coating for subsequent determinations of Pb in blood and urine matrices. The W-filament AAS instrumentation used was based on a prototype design that utilized self-reversal background correction scheme and peak area measurements. We found that Rh not only stabilized Pb during the pyrolysis step, but also facilitated the removal of carbonaceous residues during the cleaning step, requiring much less power than with phosphate modifier. Thus, the filament lifetime was greatly extended to over 300 firings. Periodic reconditioning with Rh was necessary every 30 firings or so. Conditioning the filament with Rh also permitted direct calibration using simple aqueous Pb standards. The method detection limit for blood Pb was approximately 1.5 μg dl -1, similar to that reported previously. Potential interferences from concomitants such as Na, K, Ca and Mg were evaluated. Accuracy was verified using lead reference materials from the National Institute of Standards and Technology and the New York State Department of Health. Blood lead results below 40 μg dl -1 were within ±1 μg dl -1 of certified values, and within ±10% above 40 μg dl -1; within-run precision was ±10% or better. Additional validation was reported using proficiency test materials and human blood specimens. All blood lead results were within the acceptable limits established by regulatory authorities in the US. When measuring Pb in urine, sensitivity was reduced and matrix-matched calibration became necessary. The method of detection limit was 27 μg l -1 for urine Pb. Urine lead results were also validated using an acceptable range comparable to that established for blood lead by US regulatory agencies.

  14. Bioavailability study of calcium sandoz-250 by atomic absorption spectroscopy in albino rats

    PubMed Central

    Patel, Bimalkumar N.; Krishnaveni, N.; Jivani, Nurrrudin P.; Khodakiya, Akruti S.; Khodakiya, Moorti S.; Parida, Saswat K.

    2014-01-01

    Background: Calcium sandoz-250 is an Ayurvedic calcium supplement, containing Khatika Churna. Bioavailability study of the formulation is essential for estimation of peak plasma concentration (Cmax), time to Cmax and rate of absorption. Aim: To evaluate the absorption parameters of calcium sandoz-250 in albino rats by atomic absorption spectroscopic (AAS) method. Materials and Methods: Study was carried out as a single dose, open-label, randomized study. Estimation of calcium was carried out by AAS, after validating the method for a few parameters for the estimation. Pharmacokinetic parameters such as Cmax, time to peak concentration (Tmax), area under the plasma concentration - time curve were calculated for calcium on administration of calcium sandoz-250. Results: Linearity curve was plotted for 0.5-2.5 ppm, given R2 value 0.9975. The Cmax, i.e. Cmax after administration of calcium sandoz-250 was 0.793 mg/ml at 90 min (Tmax). Measurable calcium-blood levels were noticed in all subjects up to 3.0 h after administration of calcium sandoz-250. Conclusion: Calcium sandoz-250, consisting of Khatika Churna, increases the blood calcium level in albino rats. PMID:26195909

  15. Bioavailability study of calcium sandoz-250 by atomic absorption spectroscopy in albino rats.

    PubMed

    Patel, Bimalkumar N; Krishnaveni, N; Jivani, Nurrrudin P; Khodakiya, Akruti S; Khodakiya, Moorti S; Parida, Saswat K

    2014-01-01

    Calcium sandoz-250 is an Ayurvedic calcium supplement, containing Khatika Churna. Bioavailability study of the formulation is essential for estimation of peak plasma concentration (C max), time to C max and rate of absorption. To evaluate the absorption parameters of calcium sandoz-250 in albino rats by atomic absorption spectroscopic (AAS) method. Study was carried out as a single dose, open-label, randomized study. Estimation of calcium was carried out by AAS, after validating the method for a few parameters for the estimation. Pharmacokinetic parameters such as C max, time to peak concentration (T max), area under the plasma concentration - time curve were calculated for calcium on administration of calcium sandoz-250. Linearity curve was plotted for 0.5-2.5 ppm, given R (2) value 0.9975. The C max, i.e. C max after administration of calcium sandoz-250 was 0.793 mg/ml at 90 min (T max). Measurable calcium-blood levels were noticed in all subjects up to 3.0 h after administration of calcium sandoz-250. Calcium sandoz-250, consisting of Khatika Churna, increases the blood calcium level in albino rats.

  16. Direct determination of lead in wine materials by atomic absorption spectrometry using an electrothermal atomizer with a graphite filter-insert

    NASA Astrophysics Data System (ADS)

    Zacharia, A. N.; Zhuravlev, A. S.; Chebotarev, A. N.; Arabadgi, M. V.

    2013-01-01

    The operational parameters of an atomizer with a graphite filter-insert and a Pd-Mg matrix modifier are optimized for direct electrothermal atomic absorption determination of lead in some wines and associated materials. A method is proposed for eliminating interferences from mineral and organic components, as well as from nonatomic absorption, and for increasing the detection sensitivity for the element by up to a factor of two. The lower limit for determining the amount of lead in wines is 0.0025 mg/dm3. The relative standard deviation ( S r) does not exceed 10%.

  17. Reduction of matrix interferences in furnace atomic absorption with the L'vov Platform

    USGS Publications Warehouse

    Kaiser, M.L.; Koirtyohann, S.R.; Hinderberger, E.J.; Taylor, H.E.

    1981-01-01

    Use of a modified L'vov Platform and ammonium phosphate as a matrix modifier greatly reduced matrix interferences in a commercial Massmann-type atomic absorption furnace. Platforms were readily fabricated from furnace tubes and, once positioned in the furnace, caused no inconvenience in operation. Two volatile elements (Pb, Cd), two of intermediate volatility (Co, Cr) and two which form stable oxides (Al, Sn) were tested in natural water and selected synthetic matrices. In every case for which there was a significant matrix effect during atomization from the tube wall, the platform and platform plus modifier gave improved performance. With lead, for example, an average ratio of 0.48 ?? 0.11 was found when the slope of the standard additions plot for six different natural water samples was compared to the slope of the standard working curve in dilute acid. The average slope ratio between the natural water matrices and the dilute acid matrix was 0.94 ?? 0.03 with the L'vov Platform and 0.96 ?? 0.03 with the platform and matrix modifier. In none of the cases studied did the use of the platform or platform plus modifier cause an interference problem where none existed while atomizing from the tube wall. An additional benefit of the platform was a factor of about two improvement in peak height precision. ?? 1981.

  18. Handling complex effects in slurry-sampling-electrothermal atomic absorption spectrometry by multivariate calibration.

    PubMed

    Felipe-Sotelo, M; Cal-Prieto, M J; Gómez-Carracedo, M P; Andrade, J M; Carlosena, A; Prada, D

    2006-07-07

    Analysis of solid samples by slurry-sampling-electrothermal atomic absorption spectrometry (SS-ETAAS) can imply spectral and chemical interferences caused by the large amount of concomitants introduced into the graphite furnace. Sometimes they cannot be solved using stabilized temperature platform furnace (STPF) conditions or typical approaches (previous sample ashing, use of chemical modifiers, etc.), which are time consuming and quite expensive. A new approach to handle interferences using multivariate calibrations (partial least squares, PLS, and artificial neural networks, ANN) is presented and exemplified with a real problem consisting on determining Sb in several solid matrices (soils, sediments and coal fly ash) as slurries by ETAAS. Experimental designs were implemented at different levels of Sb to develop the calibration matrix and assess which concomitants (seven ions were considered) modified the atomic signal mostly. They were Na+ and Ca2+ and they induced simultaneous displacement, depletion (enhancement) and broadening of the atomic peak. Here it is shown that these complex effects can be handled in a reliable, fast and cost-effective way to predict the concentration of Sb in slurry samples of several solid matrices. The method was validated predicting the concentrations of five certified reference materials (CRMs) and studying its robustness to current ETAAS problems. It is also shown that linear PLS can handle eventual non-linearities and that its results are comparable to more complex (non-linear) models, as those from ANNs.

  19. Slurry sampling graphite furnace atomic absorption spectrometry: determination of trace metals in mineral coal.

    PubMed

    Silva, M M; Goreti, M; Vale, R; Caramão, E B

    1999-12-06

    A procedure for lead, cadmium and copper determination in coal samples based on slurry sampling using an atomic absorption spectrometer equipped with a transversely heated graphite tube atomizer is proposed. The slurries were prepared by weighing the samples directly into autosampler cups (5-30 mg) and adding a 1.5 ml aliquot of a diluent mixture of 5% v/v HNO(3), 0.05% Triton X-100 and 10% ethanol. The slurry was homogenized by manual stirring before measurement. Slurry homogenization using ultrasonic agitation was also investigated for comparison. The effect of particle size and the use of different diluent compositions on the slurry preparation were investigated. The temperature programmes were optimized on the basis of pyrolysis and atomization curves. Absorbance characteristics with and without the addition of a palladium-magnesium modifier were compared. The use of 0.05% m/v Pd and 0.03% m/v Mg was found satisfactory for stabilizing Cd and Pb. The calibration was performed with aqueous standards. In addition, a conventional acid digestion procedure was applied to verify the efficiency of the slurry sampling. Better recoveries of the analytes were obtained when the particle size was reduced to <37 mum. Several certified coal reference materials (BCR Nos. 40, 180, and 181) were analyzed, and good agreement was obtained between the results from the proposed slurry sampling method and the certificate values.

  20. Flow injection hydride generation electrothermal atomic absorption spectrometric determination of toxicologically relevant arsenic in urine.

    PubMed

    Petrov, Panayot K; Serafimovski, Ivan; Stafilov, Trajce; Tsalev, Dimiter L

    2006-07-15

    Analytical procedure for the determination of toxicologically relevant arsenic (the sum of arsenite, arsenate, monomethylarsonate and dimethylarsinate) in urine by flow injection hydride generation and collection of generated inorganic and methylated hydrides on an integrated platform of a transverse-heated graphite atomizer for electrothermal atomic absorption spectrometric determination (ETAAS) is elaborated. Platforms are pre-treated with 2.7 micromol of zirconium and then with 0.10 micromol of iridium which serve both as an efficient hydride sequestration medium and permanent chemical modifier. Arsine, monomethylarsine and dimethylarsine are generated from diluted urine samples (10-25-fold) in the presence of 50 mmol L(-1) hydrochloric acid and 70 mmol L(-1)l-cysteine. Collection, pyrolysis and atomization temperatures are 450, 500, 2100 and 2150 degrees C, respectively. The characteristic mass, characteristic concentration and limit of detection (3sigma) are 39 pg, 0.078 microg L(-1) and 0.038 microg L(-1) As, respectively. The limits of detection in urine are ca. 0.4 and 1 microg L(-1) with 10- and 25-fold dilutions. The sample throughput rate is 25 h(-1). Applications to several urine CRMs are given.

  1. Diode-laser-based sensor for ultraviolet absorption measurements of atomic mercury

    NASA Astrophysics Data System (ADS)

    Anderson, T. N.; Magnuson, J. K.; Lucht, R. P.

    2007-04-01

    A new sensor has been developed for measuring atomic mercury using absorption spectroscopy with 254-nm radiation generated from two sum-frequency-mixed diode lasers. Beams from a 375-nm external-cavity diode laser and a 784-nm distributed feedback diode laser are mixed in a beta-barium-borate crystal to generate approximately 4 nW of ultraviolet radiation. The development of the sensor is described along with extensive characterization experiments in a mercury vapor cell in the laboratory. An accuracy of ±6% in the absolute concentration of atomic mercury has been demonstrated by comparison with equilibrium vapor pressure calculations. The detection limit is approximately 0.1 parts per billion of atomic mercury in a meter path length for 300-K gas and a 10-s integration time. The insensitivity of the sensor to broadband attenuation is demonstrated. Measurements of collision-broadening coefficients for air, N2, Ar, and CO2 are reported, and implementation of wavelength-modulation spectroscopy with the sensor is demonstrated. Finally, results are presented from measurements with the sensor in situ in the exhaust stream of an actual coal-fired combustor.

  2. Development and Validation of Spectrophotometric, Atomic Absorption and Kinetic Methods for Determination of Moxifloxacin Hydrochloride

    PubMed Central

    Abdellaziz, Lobna M.; Hosny, Mervat M.

    2011-01-01

    Three simple spectrophotometric and atomic absorption spectrometric methods are developed and validated for the determination of moxifloxacin HCl in pure form and in pharmaceutical formulations. Method (A) is a kinetic method based on the oxidation of moxifloxacin HCl by Fe3+ ion in the presence of 1,10 o-phenanthroline (o-phen). Method (B) describes spectrophotometric procedures for determination of moxifloxacin HCl based on its ability to reduce Fe (III) to Fe (II), which was rapidly converted to the corresponding stable coloured complex after reacting with 2,2′ bipyridyl (bipy). The formation of the tris-complex formed in both methods (A) and (B) were carefully studied and their absorbance were measured at 510 and 520 nm respectively. Method (C) is based on the formation of ion- pair associated between the drug and bismuth (III) tetraiodide in acidic medium to form orange—red ion-pair associates. This associate can be quantitatively determined by three different procedures. The formed precipitate is either filtered off, dissolved in acetone and quantified spectrophotometrically at 462 nm (Procedure 1), or decomposed by hydrochloric acid, and the bismuth content is determined by direct atomic absorption spectrometric (Procedure 2). Also the residual unreacted metal complex in the filtrate is determined through its metal content using indirect atomic absorption spectrometric technique (procedure 3). All the proposed methods were validated according to the International Conference on Harmonization (ICH) guidelines, the three proposed methods permit the determination of moxifloxacin HCl in the range of (0.8–6, 0.8–4) for methods A and B, (16–96, 16–96 and 16–72) for procedures 1–3 in method C. The limits of detection and quantitation were calculated, the precision of the methods were satisfactory; the values of relative standard deviations did not exceed 2%. The proposed methods were successfully applied to determine the drug in its pharmaceutical

  3. Development and validation of spectrophotometric, atomic absorption and kinetic methods for determination of moxifloxacin hydrochloride.

    PubMed

    Abdellaziz, Lobna M; Hosny, Mervat M

    2011-01-01

    Three simple spectrophotometric and atomic absorption spectrometric methods are developed and validated for the determination of moxifloxacin HCl in pure form and in pharmaceutical formulations. Method (A) is a kinetic method based on the oxidation of moxifloxacin HCl by Fe(3+) ion in the presence of 1,10 o-phenanthroline (o-phen). Method (B) describes spectrophotometric procedures for determination of moxifloxacin HCl based on its ability to reduce Fe (III) to Fe (II), which was rapidly converted to the corresponding stable coloured complex after reacting with 2,2' bipyridyl (bipy). The formation of the tris-complex formed in both methods (A) and (B) were carefully studied and their absorbance were measured at 510 and 520 nm respectively. Method (C) is based on the formation of ion- pair associated between the drug and bismuth (III) tetraiodide in acidic medium to form orange-red ion-pair associates. This associate can be quantitatively determined by three different procedures. The formed precipitate is either filtered off, dissolved in acetone and quantified spectrophotometrically at 462 nm (Procedure 1), or decomposed by hydrochloric acid, and the bismuth content is determined by direct atomic absorption spectrometric (Procedure 2). Also the residual unreacted metal complex in the filtrate is determined through its metal content using indirect atomic absorption spectrometric technique (procedure 3). All the proposed methods were validated according to the International Conference on Harmonization (ICH) guidelines, the three proposed methods permit the determination of moxifloxacin HCl in the range of (0.8-6, 0.8-4) for methods A and B, (16-96, 16-96 and 16-72) for procedures 1-3 in method C. The limits of detection and quantitation were calculated, the precision of the methods were satisfactory; the values of relative standard deviations did not exceed 2%. The proposed methods were successfully applied to determine the drug in its pharmaceutical formulations

  4. Determination and interference studies of bismuth by tungsten trap hydride generation atomic absorption spectrometry.

    PubMed

    Kula, Ibrahim; Arslan, Yasin; Bakirdere, Sezgin; Titretir, Serap; Kendüzler, Erdal; Ataman, O Yavuz

    2009-11-15

    The determination of bismuth requires sufficiently sensitive procedures for detection at the microg L(-1) level or lower. W-coil was used for on-line trapping of volatile bismuth species using HGAAS (hydride generation atomic absorption spectrometry); atom trapping using a W-coil consists of three steps. Initially BiH(3) gas is formed by hydride generation procedure. The analyte species in vapor form are transported through the W-coil trap held at 289 degrees C where trapping takes place. Following the preconcentration step, the W-coil is heated to 1348 degrees C; analyte species are released and transported to flame-heated quartz atom cell where the atomic signal is formed. In our study, interferences have been investigated in detail during Bi determination by hydride generation, both with and without trap in the same HGAAS system. Interferent/analyte (mass/mass) ratio was kept at 1, 10 and 100. Experiments were designed for carrier solutions having 1.0M HNO(3). Interferents such as Fe, Mn, Zn, Ni, Cu, As, Se, Cd, Pb, Au, Na, Mg, Ca, chloride, sulfate and phosphate were examined. The calibration plot for an 8.0 mL sampling volume was linear between 0.10 microg L(-1) and 10.0 microg L(-1) of Bi. The detection limit (3s/m) was 25 ng L(-1). The enhancement factor for the characteristic concentration (C(o)) was found to be 21 when compared with the regular system without trap, by using peak height values. The validation of the procedure was performed by the analysis of the certified water reference material and the result was found to be in good agreement with the certified values at the 95% confidence level.

  5. Atomic Oxygen Abundance in Molecular Clouds: Absorption Toward Sagittarius B2

    NASA Technical Reports Server (NTRS)

    Lis, D. C.; Keene, Jocelyn; Phillips, T. G.; Schilke, P.; Werner, M. W.; Zmuidzinas, J.

    2001-01-01

    We have obtained high-resolution (approximately 35 km/s) spectra toward the molecular cloud Sgr B2 at 63 micrometers, the wavelength of the ground-state fine-structure line of atomic oxygen (O(I)), using the ISO-LWS instrument. Four separate velocity components are seen in the deconvolved spectrum, in absorption against the dust continuum emission of Sgr B2. Three of these components, corresponding to foreground clouds, are used to study the O(I) content of the cool molecular gas along the line of sight. In principle, the atomic oxygen that produces a particular velocity component could exist in any, or all, of three physically distinct regions: inside a dense molecular cloud, in the UV illuminated surface layer (PDR) of a cloud, and in an atomic (H(I)) gas halo. For each of the three foreground clouds, we estimate, and subtract from the observed O(I) column density, the oxygen content of the H(I) halo gas, by scaling from a published high-resolution 21 cm spectrum. We find that the remaining O(I) column density is correlated with the observed (13)CO column density. From the slope of this correlation, an average [O(I)]/[(13)CO] ratio of 270 +/- 120 (3-sigma) is derived, which corresponds to [O(I)]/[(13)CO] = 9 for a CO to (13)CO abundance ratio of 30. Assuming a (13)CO abundance of 1x10(exp -6) with respect to H nuclei, we derive an atomic oxygen abundance of 2.7x10(exp -4) in the dense gas phase, corresponding to a 15% oxygen depletion compared to the diffuse ISM in our Galactic neighborhood. The presence of multiple, spectrally resolved velocity components in the Sgr B2 absorption spectrum allows, for the first time, a direct determination of the PDR contribution to the O(I) column density. The PDR regions should contain O(I) but not (13)CO, and would thus be expected to produce an offset in the O(I)-(13)CO correlation. Our data do not show such an offset, suggesting that within our beam O(I) is spatially coexistent with the molecular gas, as traced by (13)CO

  6. Determination of Hg, Cd, Mn, Pb and Sn in seafood by solid sampling Zeeman atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Detcheva, A.; Grobecker, K. H.

    2006-04-01

    Direct solid sampling Zeeman atomic absorption spectrometric methods were developed and applied to the determination of mercury, cadmium, manganese, lead and tin in seafood. All elements but mercury were measured by a third generation Zeeman atomic absorption spectrometry combined with an automatic solid sampler. In 3-field- and dynamic mode the calibrations concentration range was substantially extended and high amounts of analyte were detectable without laborious dilution of solid samples. The measurements were based on calibrations using certified reference materials of organic matrices. In case solid certified reference materials were not available calibration by aqueous standard solutions was proved to be an alternative. No matrix effects were observed under the optimized conditions. Results obtained were in good agreement with the certified values. Solid sampling Zeeman atomic absorption spectrometry proved to be a reliable, rapid and low-cost method for the control of trace elements in seafood.

  7. Liquid-phase microextraction combined with graphite furnace atomic absorption spectrometry: A review.

    PubMed

    de la Calle, Inmaculada; Pena-Pereira, Francisco; Lavilla, Isela; Bendicho, Carlos

    2016-09-14

    An overview of the combination of liquid-phase microextraction (LPME) techniques with graphite furnace atomic absorption spectrometry (GFAAS) is reported herein. The high sensitivity of GFAAS is significantly enhanced by its association with a variety of miniaturized solvent extraction approaches. LPME-GFAAS thus represents a powerful combination for determination of metals, metalloids and organometallic compounds at (ultra)trace level. Different LPME modes used with GFAAS are briefly described, and the experimental parameters that show an impact in those microextraction processes are discussed. Special attention is paid to those parameters affecting GFAAS analysis. Main issues found when coupling LPME and GFAAS, as well as those strategies reported in the literature to solve them, are summarized. Relevant applications published on the topic so far are included. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. [Determination of Cu, Zn and Fe in Huaiyao by suspension sampling-flame atomic absorption spectrometry].

    PubMed

    Wei, Wei; Qu, Ling-bo; Li, Jian-jun; Li, Yan-hong

    2002-10-01

    A new method--suspension sampling technique was applied to flame atomic absorption spectrometry and was successfully used to determine Cu, Zn, Fe in Huaiyao. Then studied the choice of suspension agent and elimination of chemical interference. The huaiyao sample was suspended in agar sol, and injected into air-acetylene flame by using standard addition method to determine Cu, Zn, Fe. Determined results were consistent with those obtained by HNO3 + H2SO4 + HClO4 method. The t-test showed that no obvious difference was found between the two methods. Displacement of HNO3 + H2SO4 + HClO4 method by suspension sampling method for the sample pretreatment is possible. This method is convenient, rapid and accurate.

  9. Comparison of phytoextraction and cold vapor atomic absorption in assessment of mercury in soils

    SciTech Connect

    Kail, B.W.

    1995-12-31

    The accumulation of uranium in pine needles has long been used as an exploration tool for uranium minerals. Recently, phytoextraction and rhizofiltration - the use of plants to remove heavy metals from contaminated soils - has seen application in bioremediation attempts. We have studied the distribution of mercury in soils of Western Pennsylvania by cold vapor atomic absorption methods and discovered anomalously high values in certain recent geological formations. Values approaching 400 ppb total mercury were found at depths as shallow as 6-8 inches in lake bottom sediments. Most of this mercury was tied up in organic form. Western Pennsylvania average total mercury content is 57 ppb (8 inorganic: 49 organic). This study presents the results of phytoextraction: using perennial root plant systems in areas previously studied and comparisons made of the results obtained by the sediment AA and phytoextraction methods.

  10. Application of atomic absorption spectroscopy for detection of multimetal traces in low-voltage electrical marks.

    PubMed

    Jakubeniene, Marija; Zakaras, Algirdas; Minkuviene, Zita Nijole; Benoshys, Alvydas

    2006-08-10

    Application of atomic absorption spectroscopy to detect multimetal traces in injured skin is a promising tool for investigation of fatalities caused by electrocution. The present paper is aimed at testing the reliability of this method for metal traces detection in electric current marks and is focused on study of peculiarities of metal penetration into the skin exposed to a current impact. Bare aluminum wire, tin-lead coated copper multistrand wire, and zinc-plated steel rope were used to make electrical marks on pig skin. It is demonstrated that amount of copper, zinc, lead, and iron may serve as statistically reliable indicators for the type of wire, which caused the electrical mark, in spite of the background content of these metals in the skin without injury. Different penetration rates for different metals contained in the wire inflicting an electrical mark were observed.

  11. Determination of calcium, magnesium and zinc in unused lubricating oils by atomic absorption spectroscopy.

    PubMed

    Udoh, A P

    1995-12-01

    Varying concentrations of lanthanum and strontium were added to solutions of ashed unused lubricating oils for the determination of calcium, magnesium and zinc content using flame atomic absorption spectrophotometry. At least 3000 mug g(-1) of lanthanum or strontium was required to completely overcome the interference of the phosphate ion, PO(3-)(4), and give peak values for calcium. The presence of lanthanum or strontium did not cause an appreciable increase in the amount of magnesium and zinc obtained from the analyses. The method is fast and reproducible, and the coefficients of variation calculated for the elements using one of the samples were 1.6% for calcium, 3.5% for magnesium and 0.2% for zinc. Results obtained by this method were better than those obtained by other methods for the same samples.

  12. Determination of palladium by graphite furnace atomic absorption spectroscopy without matrix matching.

    PubMed

    Jia, X; Wang, T; Wu, J

    2001-05-30

    A graphite furnace atomic absorption spectroscopy method for the analysis of the palladium (Pd) content in bulk pharmaceutical drug substances and their intermediates prepared in aqueous solutions is extended to samples prepared in acetonitrile (ACN) and ACN-water mixtures as well to samples prepared in dimethyl sulfoxide (DMSO) and DMSO-water mixtures. The Pd content in samples solubilized in these solvents can be accurately determined with calibration established with standards prepared in aqueous solutions without matrix matching or using the method of standard additions. The validity of this method is demonstrated by spike recovery studies and by the agreement with results for the same samples prepared in these solvents, in concentrated nitric acid, and prepared by a microwave digestion system.

  13. A novel silica trap for lead determination by hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Karadeniz Korkmaz, Deniz; Ertaş, Nusret; Yavuz Ataman, O.

    2002-03-01

    A novel silica trap for lead determination at concentration levels of ng/l was developed using hydride-generation atomic absorption spectrometry. The device consists of a 7.0-cm silica tubing which is externally heated to a desired temperature. The lead hydride vapor is generated by a conventional hydride-generation flow system. The trap is placed between the gas-liquid separator and silica T-tube; the device traps analyte species at 500 °C and releases them when heated further to 750 °C. The overall efficiency is 49%. The presence of hydrogen gas is required for revolatilization; O 2 gas must also be present. The analytical plot is linear up to 2.0 ng/ml for a collection period of 60 s. The response is also linear with respect to increasing collection periods up to 4 min. For 60-s trapping, the detection limit is 19 ng/l.

  14. Determination of selenium in urine by hydride generation atomic absorption spectrometry.

    PubMed

    Navarro, M; Lopez, H; Lopez, M C; Perez, V

    1996-01-01

    A procedure has been developed for determination of total selenium in urine by hydride generation atomic absorption spectrometry. Mineralization was performed with a nitric acid-perchloric acid mixture on a thermostated digestion block. The method was validated by comparison with the method involving mineralization in a microwave acid digestion bomb containing nitric acid and small amounts of vanadium pentoxide. Se(VI) was reduced to Se(IV) by dissolution in 7N HCl. Sample recoveries, precision studies, and analyses of a certified reference material demonstrated the reliability and accuracy of this technique. Urine samples had selenium concentrations ranging from 4.6 to 50.3 micrograms/L. These values correspond to an average of 54.9 micrograms per person per day total ingested and bioavailable Se in the daily diet.

  15. Elimination of matrix effects in electrothermal atomic absorption spectrophotometric determinations of bismuth in serum and urine.

    PubMed

    Dean, S; Tscherwonyi, P J; Riley, W J

    1992-01-01

    A sensitive and precise electrothermal atomic absorption spectrophotometric method for determining bismuth concentration is described. Protein precipitation and the use of a palladium modifier reduce the problems of foaming and permit the use of a higher ashing temperature. The detection limit of the assay is 0.9 nmol/L. Total CVs (intra- and interassay) for serum ranged from 3.5% to 15.1% and for urine from 4.8% to 14.5% at concentrations of 60.0 and 6.0 nmol/L, respectively. Analytical recoveries of bismuth added to serum and urine were 102% and 103% over the same range. The method is robust and reproducible and can be accurately calibrated with aqueous standards.

  16. Slurry sampling electrothermal atomic absorption spectrometry as screening method for chromium in compost.

    PubMed

    Laborda, F; Górriz, M P; Castillo, J R

    2004-10-20

    Ultrasonic slurry sample introduction was applied to the determination of total chromium in composted materials by electrothermal atomic absorption spectrometry (ETAAS). The effect of grinding on the heterogeneity of the test samples and on the attainable precision was studied. The repeatability was influenced by the heterogeneity of the test samples at the mug-level, the R.S.D. of the measurements being 15%. The reproducibility depended on the heterogeneity of the test sample at the mg level, and it could be improved from 11 to 7% by increasing the grinding time. The characteristic mass was 2.6pg and the detection limit for the optimised procedure at the 0.04% (w/v) slurry concentration, 370ngg(-1). Good agreement with a certified reference material and with the conventional microwave assisted digestion method was found by using external calibration with aqueous standards. The performance of the method for screening purposes was evaluated.

  17. Determination of lead in fish samples by slurry sampling electrothermal atomic absorption spectrometry.

    PubMed

    Huang, S J; Jiang, S J

    2000-08-01

    Ultrasonic slurry sampling electrothermal atomic absorption spectrometry (USS-ETAAS) was been applied to the determination of lead in several fish samples. The influences of instrument operating conditions and slurry preparation on the signal were examined. Palladium and ammonium nitrate were used as the modifier to improve the signal. Since the sensitivity to lead in various fish slurries and aqueous solutions was different, the standard additions method was used for the determination of lead in these fish samples. The method was applied to the determination of lead in dogfish muscle reference material (DORM-2) and a swordfish muscle sample purchased from the local market. The analysis results agreed with the reference value. The accuracy was better than 6%. The precision between sample replicates was better than 16% with the USS-ETAAS method. The detection limit of lead estimated from standard additions curve was about 0.053-0.058 microgram g-1 in different samples.

  18. [Determination of trace sodium ion in high purity water by graphite furnace atomic absorption spectrometry].

    PubMed

    Yuan, Xia; Shen, Shi-gang; Sun, Han-wen

    2007-01-01

    The present paper studied on the determination of trace Na+ in high purity water by graphite furnace atom absorption spectrometry. A method of directly on-line concentrating samples in graphite furnace, multiple charging, ashing, then determining once by directly charging into pools of graphite furnace, was set up. The goal of concentrating samples and avoiding contamination as well as raising sensitivity were finally achieved. To prevent the background of purity water and regent in experiment from covering the ion concentration of the sample, the authors prepared the high purity water and regent to meet the requirement of the experiment by electrodialysis in series with distillation and below-boiling-point quartz distillation at pure worktable. Satisfactory results of linearity and detection limit were obtained. The detection limit with this method was 0. 086 microg x L(-1) for Na+. The recovery was 101%-104%.

  19. [Determination of trace elements in Aloe barbadensis Miller irrigated with seawater by atomic absorption spectrophotometry].

    PubMed

    Liu, Chun-Hui; Wang, Chang-Hai; Liu, Zhao-Pu

    2008-03-01

    The dry leaves of Aloe barbadensis Miller irrigated with seawater were dissolved in nitric acid and then oxygenated by perchloric acid. Nine kinds of trace elements in the samples were determined by atomic absorption spectrophotometry, including calcium, potassium, magnesium, sodium, manganese, zinc, iron, copper and lead, with added lanthanum chloride as releaser to eliminate the interference of co-existent ions. The recoveries were 96.58%-104.31%, and the relative standard deviations of sample determination (10 times) were less than 2%. This method is simple, sensitive and rapid with satisfactory results and good reproducibility. The results indicated that there were rich Ca, Mg, K and Na, and moderate Mn, Zn and Fe elements in the Aloe barbadensis Miller irrigated with seawater. However, the concentrations of Cu and Pb were low. Therefore, Aloe barbadensis Miller irrigated with seawater has officinal and economic values. These results provide data for further research on Aloe barbadensis Miller irrigated with seawater.

  20. Determination of arsenic in vegetable samples by hydride generation atomic absorption spectrometry

    SciTech Connect

    Navarro, M.; Lopez, M.C.; Lopez, H.; Sanchez, M.

    1992-11-01

    A procedure is described for the determination of arsenic in vegetable samples by hydride generation atomic absorption spectrometry. The samples are mineralized in a microwave acid digestion bomb with nitric acid in the presence of small amounts of vanadium pentoxide. The determination of arsenic is made by the standard addition method. A certified reference sample is analyzed, and the result obtained agreed well with the certified value. The detection limit (dry weight) was about 0.020 {mu}g/g. Reproducibility relative standard deviations ranged from 6.45% at 0.152 {mu}g As/g to 8.31% at 0.059 {mu}g As/g. The concentrations of arsenic in vegetable samples ranged from 0.029 to 0.444 {mu}g/g (fresh weight). 24 refs., 4 tabs.

  1. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Coufalík, Pavel; Zvěřina, Ondřej; Komárek, Josef

    2016-04-01

    This research was aimed at the direct determination of HgS in environmental samples by means of thermal desorption coupled with atomic absorption spectrometry. Operating parameters of the apparatus used for thermal desorption (including a prototype desorption unit) are described in this work, as well as the procedure for measuring mercury release curves together with an evaluation of the analytical signal including two methods of peak integration. The results of thermal desorption were compared with HgS contents obtained by sequential extraction. The limits of quantification of the proposed method for the selective determination of the black and red forms of HgS were 4 μg kg- 1 and 5 μg kg- 1, respectively. The limit of quantification of red HgS in soils was 35 μg kg- 1. The developed analytical procedure was applied to soil and sediment samples from historical mining areas.

  2. Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

    USGS Publications Warehouse

    Zhou, L.; Chao, T.T.; Sanzolone, R.F.

    1985-01-01

    Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry. ?? 1985.

  3. An atomic-absorption method for the determination of gold in large samples of geologic materials

    USGS Publications Warehouse

    VanSickle, Gordon H.; Lakin, Hubert William

    1968-01-01

    A laboratory method for the determination of gold in large (100-gram) samples has been developed for use in the study of the gold content of placer deposits and of trace amounts of gold in other geologic materials. In this method the sample is digested with bromine and ethyl ether, the gold is extracted into methyl isobutyl ketone, and the determination is made by atomicabsorption spectrophotometry. The lower limit of detection is 0.005 part per million in the sample. The few data obtained so far by this method agree favorably with those obtained by assay and by other atomic-absorption methods. About 25 determinations can be made per man-day.

  4. Determination of some heavy metals by flame atomic absorption spectrometry before coprecipitation with neodymium hydroxide.

    PubMed

    Soylak, Mustafa; Kizil, Nebiye

    2011-01-01

    A procedure is described for the determination of trace amounts of Cd(II), Ni(II), Cu(II), Pb(II), Fe(III), Co(II), and Mn(II) that combines flame atomic absorption spectrometry with neodymium hydroxide coprecipitation. The influences of analytical parameters (amount of neodymium, pH of the model solutions, etc.) that affect quantitative recoveries of the analyte ions were investigated. The effects of concomitant ions were also examined. The detection limits for analytes were found in the range of 0.2-3.3 microg/L. The validation of the presented procedure was controlled by analysis of certified reference materials (National Institute of Standards and Technology 1570a spinach leaves and TMDA 54.4 fortified lake water). The applications of the procedure were performed by the analysis of water, food, and herbal plants from Turkey.

  5. Nickel content of human palatine tonsils: analysis of small tissue samples by flameless atomic absorption spectrophotometry.

    PubMed

    Torjussen, W; Andersen, I; Zachariasen, H

    1977-06-01

    We describe a method for determining the nickel content of small tissue samples by flameless atomic absorption spectrophotometry in this case biopsy specimens from human palatine tonsils. Contact between tissue samples and metallic objects was avoided, except for the use of biopsy forceps (Type No. 8150.00 Wolf, stainless steel) for collecting samples, to imitate the actual procedure when small biopsy specimens are removed from the nasal mucosal membranes in nickel workers for histopathological and chemical investigations. Nickel contamination from this instrument was insignificant at the precision of the present procedures. The mean concentration of nickel in 15 tonsils was 13.5 +/- 7.0 (SD) microng/100g (wet wt). The mean nickel concentration in eight different samples of the same tonsil was 5.6 +/- 2.7 (SD microng/100 g.

  6. Technique for determining nickel in blood by flameless atomic absorption spectrophotometry.

    PubMed

    Zachariasen, H; Anderson, I; Kostol, C; Barton, R

    1975-04-01

    We describe a technique for determining nickel in serum by flameless atomic absorption, with use of dimethylglyoxime. The procedure permits a greater number of analyses per technician at a relatively low cost, yet provides acceptable accuracy and reliability. After the sample is evaporated and dry ashed in a muffle furnace at 560 degrees C for 5 h, the residual salts are dissolved in hydrochloric acid (1 mol/liter). Sodium citrate and dimethylglyoxime are then added for complexation of iron and nickel, respectively. The pH is adjusted to 9 with ammonia and the nickel dimethylglyoxime is extracted with methyl isobutyl ketone. The determination is carried out by injecting 50 mul of the organic phase into the graphite furnace, where the sample is dried at 120 degrees C and ashed at 1200 degrees C, respectively.

  7. Automation of preparation of nonmetallic samples for analysis by atomic absorption and inductively coupled plasma spectrometry

    NASA Technical Reports Server (NTRS)

    Wittmann, A.; Willay, G.

    1986-01-01

    For a rapid preparation of solutions intended for analysis by inductively coupled plasma emission spectrometry or atomic absorption spectrometry, an automatic device called Plasmasol was developed. This apparatus used the property of nonwettability of glassy C to fuse the sample in an appropriate flux. The sample-flux mixture is placed in a composite crucible, then heated at high temperature, swirled until full dissolution is achieved, and then poured into a water-filled beaker. After acid addition, dissolution of the melt, and filling to the mark, the solution is ready for analysis. The analytical results obtained, either for oxide samples or for prereduced iron ores show that the solutions prepared with this device are undistinguished from those obtained by manual dissolutions done by acid digestion or by high temperature fusion. Preparation reproducibility and analytical tests illustrate the performance of Plasmasol.

  8. Determination of cyanide by a flow injection analysis-atomic absorption spectrometric method.

    PubMed

    López Gómez, A V; Martínez Calatayud, J

    1998-10-01

    A new flow injection analysis (FIA) procedure is proposed for the indirect atomic absorption spectrometric determination of cyanide. The FIA manifold is based on the insertion of the sample into a distilled water carrier, then the sample flows through a solid-phase reactor filled with silver iodide entrapped in polymeric resin beads. The calibration graph is linear over the range 0.2-6.0 mg l-1 of cyanide (correlation coefficient 0.9974), the detection limit is 0.1 mg l-1, the sample throughput is 193 h-1 and the RSD is 0.8%. The method is simple, quick and more selective than other published FIA procedures. The reproducibility obtained by using different solid-phase reactors and solutions is in the range 2.2-3.1% (RSD). The method was applied to the determination of cyanide in commercial samples such as pharmaceutical formulations and industrial electrolytic baths.

  9. Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry.

    PubMed

    Nguyen, K L; Lewis, D M; Jolly, M; Robinson, J

    2004-11-01

    The steps of the standard method to determine soluble aluminium concentration are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49-61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium concentration of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.

  10. Indirect atomic absorption spectrometric determination of ammonia, thiosulfate and cyanide in an unsegmented flow system

    SciTech Connect

    Esmadi, F.T.; Kharoaf, M.; Attiyat, A.S. )

    1990-01-01

    A flow injection analysis method (FIA), has been developed for the determination of cyanide, thiosulfate and ammonia by atomic absorption spectrometry (AAS). Aqueous solution of the analyte was injected into an on-line column containing glass beads and packed with silver chloride and deionized water was used as the carrier. The analyte dissolves the silver chloride and the dissolved silver complex is introduced to the nebulizer of the AAS. This method has proved to be sensitive, simple and precise. Detection limits of 1.0 {times} 10{sup {minus}7} M, 5.0 {times} 10{sup {minus}7}M and 5.0 {times} 10{sup {minus}6}M were obtained for thiosulfate, cyanide and ammonia, respectively. The precision of the technique was 2.0%, 2.4% and 1.4% in case of thiosulfate, cyanide and ammonia, respectively. The effects of flow rate and sample volume on the FIA/AAS signals are presented.

  11. Determination of thallium in wine by electrothermal atomic absorption spectrometry after extraction preconcentration

    NASA Astrophysics Data System (ADS)

    Cvetković, Julijana; Arpadjan, Sonja; Karadjova, Irina; Stafilov, Trajče

    2002-06-01

    A simple method for extraction electrothermal atomic absorption spectroscopy (ETAAS) determination of Tl in wine is described. The wine sample is decomposed with a mixture of nitric acid and hydrogen peroxide and both thallium species Tl(I) and Tl(III) are extracted from 0.5 mol l -1 KI solution into iso-butyl methyl ketone (IBMK). Optimal parameters for ETAAS measurement of the iodide complexes extracted were defined for two different instruments: Perkin Elmer Zeeman 3030 (HGA 600) and Varian SpectrAA-880 (GTA-100). Modifiers of tartaric acid, Pd [ammoniumtetrachloropaladate (II)] or Ag (silver nitrate) were investigated for thermal stabilization of such extremely volatile species as iodide complexes of Tl. The analytical procedure developed permits 50-fold preconcentration and determination of 0.05 μg l -1 Tl in wine. The relative standard deviation ranges from 6 to 12% for the concentration range 0.2-1 μg l -1 Tl in wine.

  12. The environmental effects of trace elements concentration in sea snails using atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    El-Amri, F. A.

    2003-05-01

    Water pollution bas increased in heavy industrialised areas. Most industrial water wastes end up in the sea. Monitoring the elemental composition in marine organisms, such as snails, provides the essential elements in living organisms and through the food chain to man. 50 samples of each of two kinds of snails have been collected from the west coast of Libya. Samples were digeste with nitric acid and the concentration of Copper, Iron, Magnesium and Zinc were determined by atomic absorption spectrometry. The results shows that Mg has the highest value while the Copper has the lowest in both kind of snaiis. A pattern of the trace elements concentration was investigated regarding the size and kind of snails.

  13. [Determination of mercury in battery by microwave digestion cold atomic absorption spectrometry].

    PubMed

    Tang, Bao-ying; Li, Yu-jie; Xie, Xiao-dan; Li, Gong-ke; Liu, Zhi-hong; Liu, Li; Li, Ying

    2004-05-01

    In this paper, a method of microwave digestion followed by cold atomic absorption spectrometry (CAAS) for the determination of mercury in battery was developed. Microwave digestion conditions and operational conditions of CAAS were optimized. The digestive solution was a mixture of hydrochloric acid-sulfuric acid (4:1, volume ratio) and the digestive time was 3 min at a microwave power of 1.0 MPa. The reaction medium was 0.5 mol x L(-1) sulfuric acid at room temperature. The characteristic concentration was 0.25 microg x L(-1). Five battery samples were determined, the recoveries were from 99.9% to 113%, and the relative standard deviations were from 4.85% to 11.9% (n = 6). The analytical results were satisfactory. The method is fast, simple, accurate and solvent-saving.

  14. [Determination of inorganic elements in different parts of Sonchus oleraceus L by flame atomic absorption spectrometry].

    PubMed

    Wang, Nai-Xing; Cui, Xue-Gui; Du, Ai-Qin; Mao, Hong-Zhi

    2007-06-01

    Flame atomic absorption spectrometry with air-acetylene flame was used for the determination of inorganic metal elements in different parts ( flower, leaf, stem and root) of Sonchus oleraceus L. The contents of Ca, Mg, K, Na, Fe, Mn, Cu, Zn, Cr, Co, Ni, Pb and Cd in the flower, leaf, stem and root of Sonchus oleraceus L were compared. The order from high to low of the additive weight (microg x g(-1)) for the 13 kinds of metal elements is as follows: leaf (77 213.72) > flower (47 927.15) > stem(42 280.99) > root (28 131.18). From the experimental results it was found that there were considerable differences in the contents of the metal elements in different parts, and there were richer contents of Fe, Zn, Mn and Cu in root and flower, which are necessary to human health, than in other parts.

  15. Multicomutation flow system for manganese speciation by solid phase extraction and flame atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Tobiasz, Anna; Sołtys, Monika; Kurys, Ewa; Domagała, Karolina; Dudek-Adamska, Danuta; Walas, Stanisław

    2017-08-01

    In the paper an application of solid phase extraction technique for speciation analysis of manganese in water samples with the use of flame atomic absorption spectrometry is presented. Two types of sorbents, activated silica gel and Dowex 1 × 4, were used respectively for simultaneously Mn2 + and MnO42 - retention and preconcentration. The whole procedure was realized in multicomutation flow system. Different conditions like: type and concentration of eluent, sample pH and loading time were tested during the study. Under appropriate conditions, it was possible to obtained enrichment factors of 20 and 16 for Mn(II) and Mn(VII), respectively. Precision of the procedure was close to 4% (measured as relative standard deviation), whereas the detection limit (3σ) was 1.4 μg·L- 1 for Mn(II) and 4.8 μg·L- 1 for Mn(VII).

  16. Determination of tributyltin in tissues and sediments by graphite furnace atomic absorption spectrometry

    SciTech Connect

    Stephenson, M.D.; Smith, D.R.

    1988-04-01

    A method for the determination of tributyltin (TBT) in tissue and sediments has been developed for environmental samples. The technique involves extraction with methylene chloride and isolation of TBT from mono- and dibutyltin with a sodium hydroxide wash. The TBT is then back extracted and converted to elemental Sn with nitric acid. Analysis is by Zeeman graphite furnace atomic absorption spectrophotometry. Recoveries of spiked samples were between 99% and 111% for mussel and fish tissues and 72% and 99% for various sediments. The limit of quantification was 0.0025 ..mu..g/g for tissue (on a wet weight basis). This technique was developed in response to their need to process large numbers of environmental samples with a minimum time investment.

  17. Optimisation of digestion method for determination of arsenic in shrimp paste sample using atomic absorption spectrometry.

    PubMed

    Ngah, C W Zanariah C W; Yahya, Mohd Adib

    2012-10-15

    The microwave digestion method was developed and verified for the determination of arsenic in shrimp paste samples. Experimental design for five factors (HNO(3) and H(2)O(2) volumes, sample weight, microwave power and digestion time) were used for the optimisation of sample digestion. For this purpose, two level half factorial design, which involves 16 experiments, was adopted. The concentration of arsenic was analysed by graphite furnace atomic absorption spectrometry. Design Expert® 7.0 software was used to interpret all data obtained. The combination of 2 mL HNO(3) and 1 mL H(2)O(2) volumes, 0.1g sample weight, 1400 W power and 5 min digestion time was found to be the optimum parameters required to digest the shrimp paste samples. Tests with spiked samples presented good recoveries with relative standard deviations between 0.32% and 5.35%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Arsenic content of Spanish cows' milk determined by dry ashing hydride generation atomic absorption spectrometry.

    PubMed

    Cervera, M L; Lopez, J C; Montoro, R

    1994-02-01

    The arsenic content of cows' milk consumed in Spain was determined. A procedure using dry ashing hydride generation atomic absorption spectrometry was developed for the purpose. Experimental conditions for the destruction of organic matter were established and an interference study was carried out. The method developed has a detection limit of 0.1 ng/g, a relative SD of 5%, and a recovery (mean +/- CSI) of 100 +/- 4%. The accuracy of the method was checked by analysis of a certified sample of IAEA milk powder (mean +/- CSI: certified, 4.85 +/- 0.32 ng/g; found, 5.04 +/- 0.81 ng/g). The proposed procedure was used to analyse cows' milk samples. The extremely low arsenic levels found do not present toxicological problems.

  19. Determination of lead and cadmium in wines by graphite furnace atomic absorption spectrometry.

    PubMed

    Kim, Meehye

    2004-02-01

    The lead (Pb) and cadmium (Cd) content of various wines on the Korean market were determined by graphite furnace atomic absorption spectrometry using Zeeman background correction and peak area mode. All wine samples were microwave-digested in concentrated HNO(3). Ammonium dihydrogen phosphate and magnesium nitrate were used as matrix modifiers for both Pb and Cd analyses. The mean Pb content of the wines was about 29 microg l(-1) ranging from 5 to 87 microg l(-1). Also, the means of Cd were about 0.5 microg l(-1) ranging from < 0.1 to 3.0 microg l(-1). The mean recoveries of Pb and Cd were 92.8 and 101.3% and their analytical detection limits were 1.0 and 0.1 microg l(-1), respectively. Sixty brands of wine were classified into red and white, but no statistically significant difference in Pb and Cd content was observed.

  20. A rapid electrothermal atomic absorption spectrophotometric method for cadmium and lead in human whole blood.

    PubMed

    Subramanian, K S; Meranger, J C

    1981-11-01

    A rapid graphite-furnace atomic absorption spectrophotometric procedure is described for determining cadmium and lead in heparinized human whole blood. A known aliquot of the blood sample is diluted fivefold with an aqueous solution composed of 5 g each of diammonium hydrogen phosphate and Triton X-100 per liter, the solution is vigorously agitated, and a 10-microL aliquot is injected into a pyrocoated graphite tube under optimized instrumental conditions. Values for Cd and Pb in the sample are obtained by direct comparison to linear working curves prepared from aqueous standards of the metals in the diammonium hydrogen phosphate-Triton medium; there is no need to use the method of standard addition or matrix-matched calibration curves. Also, the method is free of matrix effects. At least 30 samples can be analyzed per hour. The rapidity, simplicity, and sensitivity of the method make it attractive as a screening technique for routine environmental surveillance involving large throughput of samples.

  1. Arsenic Speciation of Waters from the Aegean Region, Turkey by Hydride Generation: Atomic Absorption Spectrometry.

    PubMed

    Çiftçi, Tülin Deniz; Henden, Emur

    2016-08-01

    Arsenic in drinking water is a serious problem for human health. Since the toxicity of arsenic species As(III) and As(V) is different, it is important to determine the concentrations separately. Therefore, it is necessary to develop an accurate and sensitive method for the speciation of arsenic. It was intended with this work to determine the concentrations of arsenic species in water samples collected from Izmir, Manisa and nearby areas. A batch type hydride generation atomic absorption spectrometer was used. As(V) gave no signal under the optimal measurement conditions of As(III). A certified reference drinking water was analyzed by the method and the results showed excellent agreement with the reported values. The procedure was applied to 34 water samples. Eleven tap water, two spring water, 19 artesian well water and two thermal water samples were analyzed under the optimal conditions.

  2. Development of mixed-waste analysis capability for graphite furnace atomic absorption spectrophotometry

    SciTech Connect

    Bass, D.A.; TenKate, L.B.; Wroblewski, A.

    1995-03-01

    Graphite furnace atomic absorption spectrophotometer (GFAAS) are typically configured with ventilation to capture potentially toxic and corrosive gases emitted from the vaporization of sample aliquots. When radioactive elements are present, additional concerns (such as meeting safety guidelines and ALARA principles) must be addressed. This report describes a modification to a GFAAS that provides additional containment of vaporized sample aliquots. The modification was found to increase containment by a factor of 80, given expected operating conditions. The use of the modification allows more mixed-waste samples to be analyzed, permits higher levels of radioactive samples to be analyzed, or exposes the analyst to less airborne radioactivity. The containment apparatus was attached to a Perkin-Elmer Zeeman 5000 spectrophotometer for analysis of mixed-waste samples; however, it could also be used on other systems and in other applications where greater containment of vaporized material is desired.

  3. A summary of transition probabilities for atomic absorption lines formed in low-density clouds

    NASA Technical Reports Server (NTRS)

    Morton, D. C.; Smith, W. H.

    1973-01-01

    A table of wavelengths, statistical weights, and excitation energies is given for 944 atomic spectral lines in 221 multiplets whose lower energy levels lie below 0.275 eV. Oscillator strengths were adopted for 635 lines in 155 multiplets from the available experimental and theoretical determinations. Radiation damping constants also were derived for most of these lines. This table contains the lines most likely to be observed in absorption in interstellar clouds, circumstellar shells, and the clouds in the direction of quasars where neither the particle density nor the radiation density is high enough to populate the higher levels. All ions of all elements from hydrogen to zinc are included which have resonance lines longward of 912 A, although a number of weaker lines of neutrals and first ions have been omitted.

  4. Determination of trace amounts of tin in geological materials by atomic absorption spectrometry

    USGS Publications Warehouse

    Welsch, E.P.; Chao, T.T.

    1976-01-01

    An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a nitrous oxide-acetylene flame. The limit of determination is 2 p.p.m. tin and the relative standard deviation ranges from 2 to 14 %. Up to 20 % iron and 1000 p.p.m. Cu, Pb, Zn, Mn, Hg, Mo, V, or W in the sample do not interfere. As many as 50 samples can be easily analyzed per man-day. ?? 1976.

  5. Evaluation of a carbon-rod atomizer for routine determination of trace metals by atomic-absorption spectroscopy applications to analysis of lubricating oil and crude oil.

    PubMed

    Hall, G; Bratzel, M P; Chakrabarti, C L

    1973-08-01

    A carbon-rod atomizer (CRA) fitted with a 'mini-Massmann' carbon rod was evaluated for routine analysis of petroleum and petroleum products for trace metal content by atomic-absorption spectroscopy. Aspects investigated included sensitivity, detection limit, effect of solvent type, and interferences. The results of analysis of oil samples with this technique were compared with those obtained by other techniques. Metals studied were silver, copper, iron, nickel, and lead. Sensitivity and detection limit values obtained with the CRA were similar to those obtained with the carbon-filament atomizer. Strong 'solvent effects' were observed as well as interference by cations. On the basis of this study, design changes for the CRA are suggested, with the object of minimizing 'solvent effects' and interferences, increasing the atomization efficiency, and increasing the residence time of the atomic vapour in the optical path of the instrumental system.

  6. Un Détecteur de Neutrons pour la Spectrométrie de Masses Manquantes

    NASA Astrophysics Data System (ADS)

    Bollini, D.; Buhler-Broglin, A.; Dalpiaz, P.; Massam, T.; Navach, F.; Navarria, F. L.; Schneegans, M. A.; Zichichi, A.

    A large (2 × 0.39 m3 plastic scintillator) neutron detector capable to measure with high accuracy the coordinates of the neutron interaction point as well as its time-of-flight is described. As a missing mass spectrometer, it allows to observe for example the η, meson with a mass resolution of ± 4.2 MeV. Nous décrivous un détectcur de neutrons de grand volume sensible (2 x 0,39 m3 de scintillatcur plastique) capable de mesurer avec précision les coordonnées du point d'interaction du neutron détecté ainsi que son temp-de-vol. Employé comme spectrométre de masses manquantes, it permet d'observer par exemple le méson η avec une resolution de ± 4,2 MeY.

  7. Near resonant absorption by atoms in intense fluctuating laser fields. Final report

    SciTech Connect

    Smith, S.J.

    1994-01-01

    The objective of this program was to make quantitative measurements of the effects of higher-order phase/frequency correlations in a laser beam on nonlinear optical absorption processes in atoms. The success of this program was due in large part to a unique experimental capability for modulating the extracavity beam of a stabilized ({approx_lt}200 kHz) continuous-wave laser with statistically-well-characterized stochastic phase (or frequency) fluctuations, in order to synthesize laser bandwidths to {approximately}20 MHz (depending on noise amplitude), with profiles variable between Gaussian and Lorentzian (depending on noise bandwidth). Laser driven processes investigated included the following: (1) the optical Autler-Towns effect in the 3S{sub 1/2} (F = 2, M{sub F} = 2) {yields} 3P{sub 3/2} (F = 3, M{sub F} = 3) two- level Na resonance, using a weak probe to the 4D{sub 5/2} level; (2) the variance and spectra of fluorescence intensity fluctuations in the two-level Na resonance; (3) the Hanle effect in the {sup 1}S{sub 0} {minus} {sup 3}P{sub 1}, transition at {lambda} = 555.6 nm in {sup 174} Yb; (4) absorption (and gain) of a weak probe, when the probe is a time-delayed replica of the resonant (with the two-level Na transition) pump laser; and (5) four-wave-mixing in a phase-conjugate geometry, in a sodium cell, and, finally, in a diffuse atomic sodium beam. The experimental results from these several studies have provided important confirmation of advanced theoretical methods.

  8. Quantification of strontium in plasma and urine with flameless atomic absorption spectrometry.

    PubMed

    Leeuwenkamp, O R; van der Vijgh, W J; Hüsken, B C; Lips, P; Netelenbos, J C

    1989-09-01

    This analytical method for determination of Sr in plasma and urine involves flameless atomic absorption spectrophotometry (FAAS). Drying, charring, and atomization were optimized with respect to temperature, temperature ramp, and duration for Sr in dilute HNO3 and Sr in plasma diluted 20-fold with dilute HNO3. Calibration curves (r greater than 0.995) were linear in the concentration range 5-250 micrograms/L for Sr in various media, with intercepts negligibly small except for the calibration curves in 1:1-diluted plasma and undiluted urine. The estimated detection limits for Sr in 20-fold-diluted plasma and 50-fold-diluted urine were 2 and 3 micrograms/L, respectively. Endogenous Sr in plasma and urine was estimated at 16 (SD 8) micrograms/L and 158 (SD 26) micrograms/L (n = 6), respectively. Intra- and interassay CVs were 9.1% and 5.3% for 20-fold-diluted plasma at a Sr concentration of 25 micrograms/L, and 6.9% and 4.8% at a concentration of 250 micrograms/L. The respective CVs were 8.2% and 1.2% for 50-fold-diluted urine at the low concentration, and 4.0% and 4.6% at the high concentration. In a pharmacokinetic pilot study of 2.5 mmol of Sr orally administered to a healthy volunteer, the peak plasma concentration of Sr, 4.4 mg/L, decayed bi-exponentially [t1/2, alpha = 24 h, t1/2, beta = 77 h]; the estimated first-order absorption rate constant was 0.005 min-1; and the observed decay (day 0-6) of the urinary Sr/creatinine ratio closely paralleled the plasma decay [t1/2 = 70 h].

  9. Determination of mercury in carbon black by cold vapor atomic absorption spectrometry.

    PubMed

    Hepp, Nancy M

    2006-01-01

    Recently, a new color additive, D&C Black No. 2, a high-purity furnace black in the general category of carbon blacks, was listed as a color subject to batch certification by the U.S. Food and Drug Administration. A simple procedure was developed to determine mercury (Hg) in D&C Black No. 2, which is limited by specification to not more than 1 ppm Hg. The method uses partial acid digestion followed by cold vapor atomic absorption and was developed by modifying a method used for other color additives. The carbon black samples are treated with a mixture of nitric and hydrochloric acids and heated by microwave in sealed Teflon vessels. The resulting solutions, which are stable to Hg loss for at least 1 week, are diluted and analyzed for Hg using cold vapor atomic absorption spectrometry. Validation was performed by spiking carbon black samples with inorganic Hg (HgNO3) at levels from 0.1 to 1.5 microg/g, and by analyzing 2 standard reference materials. At the specification level of 1 ppm Hg (1 microg Hg/g), the 95% confidence interval was +/-0.01 ppm Hg (0.01 microg Hg/g). The method developed in this study gave good results for very difficult-to-analyze materials, such as coal standard reference materials and carbon black. By eliminating volatility and adsorption factors through the formation of HgCl4(-2) complexes, one can avoid using extremely hazardous acids such as HF and HClO4.

  10. Free-free absorption of infrared radiation in collisions of electrons with neutral rare-gas atoms

    NASA Technical Reports Server (NTRS)

    Stallcop, J. R.

    1974-01-01

    A relationship between the inverse bremsstrahlung absorption cross section and the electron neutral momentum transfer cross section has been utilized to determine the infrared free-free continuum absorption coefficient for the negative ions of helium, neon, argon, krypton, and xenon. The values of the momentum transfer cross section for this calculation have been obtained from experimental measurements. Analytical expressions for the absorption coefficient have also been developed. From the results of this calculation, it is possible to determine the absorption coefficient per unit electron density per neutral atom for temperatures in the range from 2500 to 25,000 K. The results are compared with those from tabulations of previous calculations and those computed from theoretical values of the phase shifts for the elastic scattering of electrons by neutral atoms.

  11. X-ray atomic absorption of cesium and xenon in the L-edge region

    SciTech Connect

    Kodre, A.; Padeznik Gomilsek, J.; Arcon, I.; Aquilanti, G.

    2010-08-15

    X-ray absorption of atomic cesium is measured in the L-edge region, using a beryllium-window cell for cesium vapor. For comparison, absorption in Xe gas in the same energy region is remeasured with improved signal-to-noise ratio. By combining deconvolution and modeling, the edge profiles are studied to determine the threshold energies and the shape of the edge apex with exponential slope of the high-energy flank. In both elements, multielectron excitations show the same basic ordering in compact groups, largely independent of the core-hole subshell, following the energy sequence of coexcited valence and subvalence orbitals. The main effect of 6s electron in Cs, apart from 2(s,p)6s excitation, is the enhancement of single- as well as some multielectron resonant channels. The spectra of both elements show the ''polarization effect'': a convex basic curvature of the L{sub 2} and L{sub 3} segments, a concave L{sub 1} segment. Previously, Kutzner demonstrated a convincing theoretical explanation of the effect on Xe in a relativistic random-phase approximation with relaxation involving overlap integrals with continuum [Rad. Phys. Chem. 70, 95 (2004)].

  12. Arecibo Multi-epoch H I Absorption Measurements Against Pulsars: Tiny-scale Atomic Structure

    NASA Astrophysics Data System (ADS)

    Stanimirović, S.; Weisberg, J. M.; Pei, Z.; Tuttle, K.; Green, J. T.

    2010-09-01

    We present results from multi-epoch neutral hydrogen (H I) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10-150 AU yr-1, these pulsars have swept across 1-200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny-scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their H I absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 101-103 AU, as previously suggested by some work. In the direction of B1929+10, an apparent correlation between TSAS and interstellar clouds inside the warm Local Bubble (LB) indicates that TSAS may be tracing the fragmentation of the LB wall via hydrodynamic instabilities. While similar fragmentation events occur frequently throughout the ISM, the warm medium surrounding these cold cloudlets induces a natural selection effect wherein small TSAS clouds evaporate quickly and are rare, while large clouds survive longer and become a general property of the ISM.

  13. ARECIBO MULTI-EPOCH H I ABSORPTION MEASUREMENTS AGAINST PULSARS: TINY-SCALE ATOMIC STRUCTURE

    SciTech Connect

    Stanimirovic, S.; Weisberg, J. M.; Pei, Z.; Tuttle, K.; Green, J. T.

    2010-09-01

    We present results from multi-epoch neutral hydrogen (H I) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10-150 AU yr{sup -1}, these pulsars have swept across 1-200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny-scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their H I absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 10{sup 1}-10{sup 3} AU, as previously suggested by some work. In the direction of B1929+10, an apparent correlation between TSAS and interstellar clouds inside the warm Local Bubble (LB) indicates that TSAS may be tracing the fragmentation of the LB wall via hydrodynamic instabilities. While similar fragmentation events occur frequently throughout the ISM, the warm medium surrounding these cold cloudlets induces a natural selection effect wherein small TSAS clouds evaporate quickly and are rare, while large clouds survive longer and become a general property of the ISM.

  14. In situ atomic force microscopy observation of hydrogen absorption/desorption by Palladium thin film

    NASA Astrophysics Data System (ADS)

    Matsumoto, Itoko; Sakaki, Kouji; Nakamura, Yumiko; Akiba, Etsuo

    2011-12-01

    Grain structure changes in Pd thin film during hydrogen absorption and desorption were observed by in situ atomic force microscopy. The as-sputtered film had a smooth flat surface with 20-30 nm grains. Film that absorbed hydrogen showed buckling, caused by the compressive stress due to lattice expansion as Pd metal reacted with hydrogen to form the hydride. Grains on the buckles were agglomerated and deformed unlike those on flat areas beside the buckles. Film that absorbed and then desorbed hydrogen still showed some buckling; however, many buckles shrank and flattened when the compressive stress of lattice expansion was released during desorption. On both the remaining and the shrunken buckles, grain agglomeration was retained; whereas, the deformed grains reverted back to their original form. X-ray diffraction indicated compressive residual stress in the as-sputtered film and tensile residual stress in the film after hydrogen absorption/desorption. These results indicate that irreversible grain agglomeration is related to residual tensile stress in the film although agglomeration occurs only on the buckled areas.

  15. Analytical application of 2f-wavelength modulation for isotope selective diode laser graphite furnace atomic absorption spectroscopy.

    PubMed

    Wizemann, H D

    2000-01-01

    Experiences in the analytical application of the 2f-wavelength modulation technique for isotope selective atomic absorption spectroscopy in a graphite furnace are reported. Experimental as well as calculated results are presented, mainly for the natural lithium isotopes. Sensitivity, linearity, and (isotope) selectivity are studied by intensity modulation and wavelength modulation. High selectivities can be attained, however, on the cost of detection power. It is shown that the method enables the measurement of lithium isotope ratios larger than 2000 by absorption in a low-pressure graphite tube atomizer.

  16. Assessing the engagement, learning, and overall experience of students operating an atomic absorption spectrophotometer with remote access technology.

    PubMed

    Erasmus, Daniel J; Brewer, Sharon E; Cinel, Bruno

    2015-01-01

    The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of engagement, learning, and overall experience. Feedback from students suggests that the use of remote access technology is effective in teaching students the principles of chemical analysis by atomic absorption spectroscopy. © 2014 The International Union of Biochemistry and Molecular Biology.

  17. Direct determination and speciation of mercury compounds in environmental and biological samples by carbon bed atomic absorption spectroscopy

    SciTech Connect

    Skelly, E.M.

    1982-01-01

    A method was developed for the direct determination of mercury in water and biological samples using a unique carbon bed atomizer for atomic absorption spectroscopy. The method avoided sources of error such as loss of volatile mercury during sample digestion and contamination of samples through added reagents by eliminating sample pretreatment steps. The design of the atomizer allowed use of the 184.9 nm mercury resonance line in the vacuum ultraviolet region, which increased sensitivity over the commonly used spin-forbidden 253.7 nm line. The carbon bed atomizer method was applied to a study of mercury concentrations in water, hair, sweat, urine, blood, breath and saliva samples from a non-occupationally exposed population. Data were collected on the average concentration, the range and distribution of mercury in the samples. Data were also collected illustrating individual variations in mercury concentrations with time. Concentrations of mercury found were significantly higher than values reported in the literature for a ''normal'' population. This is attributed to the increased accuracy gained by eliminating pretreatment steps and increasing atomization efficiency. Absorption traces were obtained for various solutions of pure and complexed mercury compounds. Absorption traces of biological fluids were also obtained. Differences were observed in the absorption-temperatures traces of various compounds. The utility of this technique for studying complexation was demonstrated.

  18. Determination of mercury(II) ion by electrochemical cold vapor generation atomic absorption spectrometry.

    PubMed

    Arbab-Zavar, M Hosein; Rounaghi, G Hosein; Chamsaz, Mahmoud; Masrournia, Mahboube

    2003-05-01

    A technique for determination of mercury is described; it is based on electrolytic reduction of Hg(II) ion on a graphite cathode, the trapping of mercury vapor and its volatilization into a quartz tube aligned in the optical path of an atomic absorption spectrometer. The electrochemical cell consisted of a graphite cathode and an anode operating with constant direct current for the production of mercury atoms. A pre-activated graphite rod was used as the cathode material. The optimum conditions for electrochemical generation of mercury cold vapor (the electrolysis time and current, the flow rate, the type of electrode and electrolyte) were investigated. The characteristic electrochemical data with chemical cold vapor using NaBH4-acid were compared. The presence of cadmium(II), arsenic(III), antimony(III), selenium(IV), bismuth(III), silver(I), lead(II), lithium(I), sodium(I) and potassium(I) showed interference effects which were eliminated by suitable separation techniques. The calibration curve is linear over the range of 5-90 ng ml(-1) mercury(II). The detection limit is 2 ng ml(-1) of Hg(II) and the RSD is 2.5% (n = 10) for 40 ng ml(-1). The accuracy and recovery of the method were investigated by analyzing spiked tap water and river water.

  19. Determination of lead in fine particulates by slurry sampling electrothermal atomic absorption spectrometry.

    PubMed

    Yu, J C; Ho, K F; Lee, S C

    2001-01-02

    A simple method for determining lead in fine particulates (PM2.5) by using electrothermal atomic absorption spectrometry (ETAAS) has been developed. Particulates collected on Nuclepore filter by using a dichotomous sampler were suspended in diluted nitric acid after ultrasonic agitation. The dislodging efficiency is nearly 100% after agitation for 5 min. In order to study the suspension behavior of PM2.5 in solvents, a Brookhaven ZetaPlus Particle Size Analyzer was used to determine the particle size distribution and suspension behavior of air particulates in the solvent. The pre-digestion and modification effect of nitric acid would be discussed. Palladium was added as a chemical modifier and the temperature program of ETAAS was changed in order to improve the recovery. The slurry was introduced directly into a graphite tube for atomization. The metal content in the sample was determined by the standard addition method. In addition, a conventional acid digestion procedure was applied to verify the efficiency of the slurry sampling method. It offers a quick and efficient alternative method for heavy metal characterization in fine particulates.

  20. Determination of tellurium in indium antimonide semiconductor material by electrothermal atomic absorption spectrometry.

    PubMed

    Shiue, M Y; Sun, Y C; Yang, M H

    2001-08-01

    A method for the determination of the dopant concentration of tellurium in dissolved indium antimonide semiconductor material by electrothermal atomic absorption spectrometry (ETAAS) was developed. Efforts were made to investigate the optimal conditions of the furnace heating program and the effect of palladium modifier on the variation of tellurium and the background absorbance. According to the results obtained, the presence of palladium chemical modifier in the analysis of indium antimonide allowed the successful retention of tellurium in the graphite tube, and the optimum mass of palladium modifier was found to be dependent on the sample matrix concentration. The absorbance profile of tellurium and the background level were significantly improved when a pyrolysis temperature of 1100 degrees C and an atomization temperature of 2200 degrees C were employed in the optimized heating program. With the use of this method, a detection limit of 0.8 microg g(-1) tellurium in indium antimonide could be achieved. The applicability of the proposed method was evaluated by comparison with two independent methods, i.e. slurry sampling-ETAAS and ICP-MS. From the good agreement between the results, it was demonstrated that the proposed method is suitable for the determination of typical dopant concentrations of tellurium in indium antimonide.

  1. [Determination of trace gallium by graphite furnace atomic absorption spectrometry in urine].

    PubMed

    Zhou, L Z; Fu, S; Gao, S Q; He, G W

    2016-06-20

    To establish a method for determination trace gallium in urine by graphite furnace atomic absorption spectrometry (GFAAS). The ammonium dihydrogen phosphate was matrix modifier. The temperature effect about pyrolysis (Tpyr) and atomization temperature were optimized for determination of trace gallium. The method of technical standard about within-run, between-run and recoveries of standard were optimized. The method showed a linear relationship within the range of 0.20~80.00 μg/L (r=0.998). The within-run and between-run relative standard deviations (RSD) of repetitive measurement at 5.0, 10.0, 20.0 μg/L concentration levels were 2.1%~5.5% and 2.3%~3.0%. The detection limit was 0.06 μg/L. The recoveries of gallium were 98.2%~101.1%. This method is simple, low detection limit, accurate, reliable and reproducible. It has been applied for determination of trace gallium in urine samples those who need occupation health examination or poisoning diagnosis.

  2. Electronically excited rubidium atom in helium clusters and films. II. Second excited state and absorption spectrum.

    PubMed

    Leino, Markku; Viel, Alexandra; Zillich, Robert E

    2011-01-14

    Following our work on the study of helium droplets and film doped with one electronically excited rubidium atom Rb(∗) ((2)P) [M. Leino, A. Viel, and R. E. Zillich, J. Chem. Phys. 129, 184308 (2008)], we focus in this paper on the second excited state. We present theoretical studies of such droplets and films using quantum Monte Carlo approaches. Diffusion and path integral Monte Carlo algorithms combined with a diatomics-in-molecule scheme to model the nonpair additive potential energy surface are used to investigate the energetics and the structure of Rb(∗)He(n) clusters. Helium films as a model for the limit of large clusters are also considered. As in our work on the first electronic excited state, our present calculations find stable Rb(∗)He(n) clusters. The structures obtained are however different with a He-Rb(∗)-He exciplex core to which more helium atoms are weakly attached, preferentially on one end of the core exciplex. The electronic absorption spectrum is also presented for increasing cluster sizes as well as for the film.

  3. Determination of trace impurities in titanium dioxide by slurry sampling electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Dong, Huang Mao; Krivan, Viliam; Welz, Bernhard; Schlemmer, Gerhard

    1997-10-01

    A slurry sampling electrothermal atomic absorption spectrometry method for the determination of Al, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Tl and Zn in powdered titanium dioxide is described. The behaviour of the titanium matrix in the atomizer and its interferences with the determination of Al, Fe, Co, Ni and Mn were studied. A tungsten carbide modified graphite tube was used to improve the signal shape and the repeatability for the determination of Fe. For all elements, except for Cd and Pb, quantification by a calibration curve established with aqueous standards was possible. No chemical modifier was used throughout in order to minimize contamination. For the contamination risk elements such as Ca, Fe, K, Mg, Na and Zn, the slurry sampling technique allows to achieve limits of detection (3 σ of the blank) 5-20 times lower than the solution technique, resulting for these elements in values of 1, 3, 0.5, 0.5, 0.9 and 2 ng g -1, respectively, and, generally being in the range of 0.2 ng g -1 (Cd) to 10 ng g -1 (Al and Tl). The results obtained by the slurry sampling technique are compared with those of other independent methods including four solution methods and neutron activation analysis.

  4. Determination of cadmium by flow injection-chemical vapor generation-atomic absorption spectrometry.

    PubMed

    Vargas-Razo, C; Tyson, J F

    2000-01-01

    A method was developed for the generation of a "cold vapor" of cadmium by means of flow injection-chemical vapor generation from aqueous samples, the determination being conducted with an atomic absorption spectrometer (Pyrex glass T-cell). Several gas-liquid separator designs, atomizer designs, and the effect of several reagents previously reported as sensitivity enhancers (including cobalt, nickel, thiourea and didodecyl-dimethylammonium bromide) were investigated. The limit of detection, calculated as the concentration giving a signal equal to three times the standard deviation of the blank, was 16 ng L(-1), and the relative standard deviation was 1.4% for a concentration of 2 microg L(-1) and 3.8% for 0.1 microg L(-1). The addition of nickel and thiourea to the samples provided improved tolerance to the interference of coexisting ions. Two NIST certified reference materials, Montana Soil and Apple Leaves (respectively containing 41.7+/-0.25 mg kg(-1) Cd and 0.013+/-0.002 mg kg(-1) Cd) were accurately analyzed. The interference of lead was overcome by coprecipitation with barium sulfate, and the experimental values obtained were 41+/-1 mg kg(-1) Cd and 0.013+/-0.002 mg kg(-1) Cd, respectively.

  5. Atomic-scale roughness of Li metal surface evident in soft X-ray absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Prendergast, David; Wan, Liwen; Liang, Yufeng; Chuang, Yi-De; Qiao, Ruimin; Yan, Shishen; Yang, Wanli

    2015-03-01

    Realizing Li metal electrodes depends on fundamental understanding and efficient control of surface properties, which requires reliable characterization of the Li metal surface. Controlled experiments of Li K-edge soft X-ray absorption spectroscopy (XAS) reveal evidence of steady oxidation of the Li metal surface even under ultrahigh vacuum (UHV) conditions. The XAS of the short-lived Li metal surface, prepared by in-situ scratching, exhibits a prominent peak at 55.6 eV, more intense and at a slightly higher energy than the first peak expected for bulk Li metal at 55 eV. First-principles XAS calculations explain the origin of both the increased intensity and energy shift. This required the use of surface structural models with under-coordinated Li atoms and an estimated 4 Åinelastic mean-free-path for Auger electrons, implying extreme surface sensitivity of the measurements to the first 2-3 atomic layers. This work provides a benchmark on both experiment and theory for further studies of Li and other reactive metal surfaces, which are currently under scrutiny for next-generation energy storage devices. DP, LW, and YL acknowledge support from the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the US Dept. of Energy, Office of Science, Basic Energy Sciences.

  6. Determination of selenium in human spermatozoa and prostasomes using base digestion and electrothermal atomic absorption spectrophotometry.

    PubMed

    Suistomaa, U; Saaranen, M; Vanha-Perttula, T

    1987-10-15

    A method for the determination of selenium in human spermatozoa and prostasomes is described. The samples were digested with 25% (w/v) tetramethylammonium hydroxide (TMAH) in methanol and analyzed by atomic absorption spectrometry with electrothermal atomization and Zeeman background correction (ET-AAS). Nickel was used as a matrix modifier. Calibration was performed using the matrix-based calibration curve. The TMAH-digestion method agreed well with a conventional digestion procedure using concentrated nitric acid. The TMAH-digestion does not require heating or strong acids and it was suitable for small biological samples. The average recovery of added selenium in spermatozoan digests was 95.1 +/- 5.2% (n = 5). The coefficient of variation was 9.1% (n = 21). The accuracy of the method tested with the NBS standard 1577 (bovine liver, certified at 1.1 +/- 0.1 micrograms Se/g) resulted in a value of 0.98 +/- 0.10 micrograms Se/g (n = 16). The method was further tested in an interlaboratory comparison study.

  7. Determination of silicon in serum and urine by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Huang, Zhuo-er

    1995-09-01

    A sensitive, simple and accurate method for the routine determination of trace silicon in serum and urine by Zeeman electrothermal atomic absorption spectrometry is described. The samples are directly determined after 20-fold dilution of serum and 100-fold dilution of urine. No L'vov platform is used. The signal enhancement of silicon atomization in pyrolytic graphite coated graphite tubes is achieved by using a mixture of calcium chloride and lanthanum nitrate as chemical modifier. The interferences arising from the biological matrices have been eliminated by the addition of ammonium dihydrogenphosphate in the sample solutions. The aqueous calibration curve is linear to at least 300 μg l -1, the characteristic mass is 37 pg (integrated absorbance signal), whereas the detection limit (3SD) is 1.5 μg l -1 for silicon in both diluted serum and urine samples. The recoveries of silicon added to the diluted samples are 101 ± 1.8% for sera and 98.2 ± 3.5% for the urine specimens, independent of the dilution ratio. The silicon measurement results for the serum and urine from healthy adults and for the serum from the patients with chronic renal failure on hemodialysis are presented.

  8. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    SciTech Connect

    Pascucci, I.; Simon, M. N.; Edwards, S.; Heyer, M.; Rigliaco, E.; Hillenbrand, L.; Gorti, U.; Hollenbach, D.

    2015-11-20

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions.

  9. Electrothermal atomic absorption spectrometric determination of arsenic in essential lavender and rose oils.

    PubMed

    Karadjova, Irina B; Lampugnani, Leonardo; Tsalev, Dimiter L

    2005-02-28

    Analytical procedures for electrothermal atomic absorption spectrometric (ETAAS) determination of arsenic in essential oils from lavender (Lavendula angustifolia) and rose (Rosa damascena) are described. For direct ETAAS analysis, oil samples are diluted with ethanol or i-propanol for lavender and rose oil, respectively. Leveling off responses of four different arsenic species (arsenite, arsenate, monomethylarsonate and dimethylarsinate) is achieved by using a composite chemical modifier: l-cysteine (0.05gl(-1)) in combination with palladium (2.5mug) and citric acid (100mug). Transverse-heated graphite atomizer (THGA) with longitudinal Zeeman-effect background correction and 'end-capped' graphite tubes with integrated pyrolytic graphite platforms, pre-treated with Zr-Ir for permanent modification are employed as most appropriate atomizer. Calibration with solvent-matched standard solutions of As(III) is used for four- and five-fold diluted samples of lavender and rose oil, respectively. Lower dilution factors required standard addition calibration by using aqueous (for lavender oil) or i-propanol (for rose oil) solutions of As(III). The limits of detection (LOD) for the whole analytical procedure are 4.4 and 4.7ngg(-1) As in levender and rose oil, respectively. The relative standard deviation (R.S.D.) for As at 6-30ngg(-1) levels is between 8 and 17% for both oils. As an alternative, procedure based on low temperature plasma ashing in oxygen with ETAAS, providing LODs of 2.5 and 2.7ngg(-1) As in levender and rose oil, respectively, and R.S.D. within 8-12% for both oils has been elaborated. Results obtained by both procedures are in good agreement.

  10. Determination of some antihistaminic drugs by atomic absorption spectrometry and colorimetric methods.

    PubMed

    El-Kousy, N; Bebawy, L I

    1999-08-01

    Atomic absorption spectrometry (AAS) and colourimetric methods have been developed for the determination of pizotifen (I), ketotifen (II) and loratadine (III). The first method depends on the reaction of the three drugs (I); (II) and (III) with cobalt thiocyanate reagent at pH 2 to give ternary complexes. These complexes are readily extracted with organic solvent and estimated by indirect atomic absorption method via the determination of the cobalt content in the formed complex after extraction in 0.1 M hydrochloric acid. It was found that the three drugs can be determined in the concentration ranges from 10 to 74, 12 to 95 and 10 to 93 microg ml(-1) with mean percentage recovery of 99.71+/-0.87, 99.70+/-0.79 and 99.62+/-0.75%, respectively. The second method is based on the formation of orange red ion pairs as a result of the reaction between (I); (II) and (III) and molybdenum thiocyanate with maximum absorption at 469.5 nm in dichloromethane. Appropriate conditions were established for the colour reaction. Under the proposed conditions linearity was obeyed in the concentration ranges 3.5-25, 5-37.5 and 2.5-22.5 microg ml(-1) with mean percentage recovery of 99.60+/-0.41, 100.11+/-0.43 and 99.31+/-0.47% for (I): (II) and (III), respectively. The third method depends on the formation of radical ion using 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ). The colour formed was measured at 588 nm for the three drugs (I); (II) and (III), respectively. The method is valid in concentration range 10-80 microg ml(-1) with mean percentage recovery 99.75+/-0.44, 99.94+/-0.72 and 99.17+/-0.36% for (I); (II) and (III), respectively. The proposed methods were applied to the analysis of pharmaceutical preparations. The results obtained were statistically analysed and compared with those obtained by applying the official and reference methods.

  11. Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.

    ERIC Educational Resources Information Center

    Anderson, James L.; And Others

    1980-01-01

    Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

  12. Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.

    ERIC Educational Resources Information Center

    Anderson, James L.; And Others

    1980-01-01

    Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

  13. Speciation and determination of tin(IV) and organotin compounds in sea-water by hydride generation-atomic-absorption spectrometry with an electrically heated long absorption cell.

    PubMed

    Chamsaz, M; Khasawneh, I M; Winefordner, J D

    1988-07-01

    A method is described for the determination of nanogram or subnanogram amounts of Sn(IV) and the halides of methyltin, dimethyltin, trimethyltin, n-butyltin, dibutyltin, and tributyltin. These compounds are volatilized from water samples by hydride generation, collected on a chromatographic stationary phase, desorbed in order of increasing boiling point, and detected by atomic-absorption spectrometry with atomization in a long electrothermally heated alumina tube furnace. The absolute detection limits are in the range 0.4-1.5 ng with a reproducibility of 4-15% for inorganic tin and organotin compounds.

  14. The possibility of standardless analysis in graphite furnace atomic absorption spectrometry: determination of gold in geological samples

    NASA Astrophysics Data System (ADS)

    Wei-min, Yang; Zhe-ming, Ni

    1996-01-01

    This paper investigates the possibility of standardless analysis for gold in geological samples using graphite furnace atomic absorption spectrometry. A simplex optimization method is employed to select the optimum experimental conditions for both the conventional and fast furnace programs. The atomization efficiency ( ɛA = 100 × m0(calc)/ m0(exp)) for gold appears to be temperature dependent and is found to be around at 100% at higher atomization temperature. The results show that the standardless determination of gold could be performed in geological samples with the use of palladium as the matrix modifier and the accuracy is better than 7%.

  15. Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Freschi, Gian P. G.; Dakuzaku, Carolina S.; de Moraes, Mercedes; Nóbrega, Joaquim A.; Gomes Neto, José A.

    2001-10-01

    A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l -1 HNO 3 and in 1+1 v/v diluted wine using mixtures of Pd(NO 3) 2+Mg(NO 3) 2 and NH 4H 2PO 4+Mg(NO 3) 2 as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l -1 HNO 3, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10-1.0 μg l -1 Cd and 5.0-50 μg l -1 Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l -1 for Cd, 0.8 μg l -1 for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l -1 and for Pb at 500 μg l -1. The relative standard deviations ( n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.

  16. Correlation between the Gas Temperature and the Atomization Behavior of Analyte Elements in Flame Atomic Absorption Spectrometry Estimated with a Continuum-light-source Spectrometer System

    NASA Astrophysics Data System (ADS)

    Toya, Yusuke; Itagaki, Toshiko; Wagatsuma, Kazuaki

    2016-11-01

    In flame atomic absorption spectrometry (FAAS), the gas temperature for two types of the gas compositions, which was estimated based on a two-line method by using a simultaneous multi-wavelength spectrometer, on which a line pair of ruthenium, Ru I 372.692 nm and Ru I 372.803 nm having different excitation energies, was measured at the same time. Also using the spectrometer system, the absorption signals of both iron and ruthenium, whose oxides had different thermodynamic properties: the latter oxide was decomposed much more easily than the former one, were investigated with a nitrous oxide - acetylene flame, in comparison with an air - acetylene flame. The fuel/oxidant ratio of both the flames as well as the height of the optical path was varied as an experimental parameter. The atomization behavior of iron and ruthenium, which could be deduced from a variation in their absorption signals, was considered to be dependent not only on the gas temperature but on reducing atmosphere of the flame gas, which might be attributed to reducing radicals in a fuel-excess flame consisting of nitrous oxide. In the nitrous oxide - acetylene flame, a broader optical path having a constant and higher temperature was obtained, thus contributing to formation of analyte atoms with a stable atomization efficiency and eventually to better precision in the analytical result in FAAS.

  17. Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

    ERIC Educational Resources Information Center

    Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

    2016-01-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

  18. Assessing the Engagement, Learning, and Overall Experience of Students Operating an Atomic Absorption Spectrophotometer with Remote Access Technology

    ERIC Educational Resources Information Center

    Erasmus, Daniel J.; Brewer, Sharon E.; Cinel, Bruno

    2015-01-01

    The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of…

  19. Overcoming Matrix Effects in a Complex Sample: Analysis of Multiple Elements in Multivitamins by Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad

    2011-01-01

    A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…

  20. Assessing the Engagement, Learning, and Overall Experience of Students Operating an Atomic Absorption Spectrophotometer with Remote Access Technology

    ERIC Educational Resources Information Center

    Erasmus, Daniel J.; Brewer, Sharon E.; Cinel, Bruno

    2015-01-01

    The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of…

  1. A Simplified Digestion Protocol for the Analysis of Hg in Fish by Cold Vapor Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Kristian, Kathleen E.; Friedbauer, Scott; Kabashi, Donika; Ferencz, Kristen M.; Barajas, Jennifer C.; O'Brien, Kelly

    2015-01-01

    Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

  2. Overcoming Matrix Effects in a Complex Sample: Analysis of Multiple Elements in Multivitamins by Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad

    2011-01-01

    A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…

  3. Manganese dioxide causes spurious gold values in flame atomic-absorption readings from HBr-Br2 digestions

    USGS Publications Warehouse

    Campbell, W.L.

    1981-01-01

    False readings, apparently caused by the presence of high concentrations of manganese dioxide, have been observed in our current flame atomic-absorption procedure for the determination of gold. After a hydrobromic acid (HBr)-bromine (Br2) leach, simply heating the sample to boiling to remove excess Br2 prior to extraction with methyl-isobutyl-ketone (MIBK) eliminates these false readings. ?? 1981.

  4. VUV absorption spectroscopy measurements of the role of fast neutral atoms in high-power gap breakdown

    SciTech Connect

    FILUK,A.B.; BAILEY,JAMES E.; CUNEO,MICHAEL E.; LAKE,PATRICK WAYNE; NASH,THOMAS J.; NOACK,DONALD D.; MARON,Y.

    2000-03-20

    The maximum power achieved in a wide variety of high-power devices, including electron and ion diodes, z pinches, and microwave generators, is presently limited by anode-cathode gap breakdown. A frequently-discussed hypothesis for this effect is ionization of fast neutral atoms injected throughout the anode-cathode gap during the power pulse. The authors describe a newly-developed diagnostic tool that provides the first direct test of this hypothesis. Time-resolved vacuum-ultraviolet absorption spectroscopy is used to directly probe fast neutral atoms with 1 mm spatial resolution in the 10 mm anode-cathode gap of the SABRE 5 MV, 1 TW applied-B ion diode. Absorption spectra collected during Ar RF glow discharges and with CO{sub 2} gas fills confirm the reliability of the diagnostic technique. Throughout the 50--100 ns ion diode pulses no measurable neutral absorption is seen, setting upper limits of 0.12--1.5 x 10{sup 14} cm{sup {minus}3} for ground state fast neutral atom densities of H, C, N, O, F. The absence of molecular absorption bands also sets upper limits of 0.16--1.2 x 10{sup 15} cm{sup {minus}3} for common simple molecules. These limits are low enough to rule out ionization throughout the gap as a breakdown mechanism. This technique can now be applied to quantify the role of neutral atoms in other high-power devices.

  5. Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

    ERIC Educational Resources Information Center

    Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

    2016-01-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

  6. A Simplified Digestion Protocol for the Analysis of Hg in Fish by Cold Vapor Atomic Absorption Spectroscopy

    ERIC Educational Resources Information Center

    Kristian, Kathleen E.; Friedbauer, Scott; Kabashi, Donika; Ferencz, Kristen M.; Barajas, Jennifer C.; O'Brien, Kelly

    2015-01-01

    Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

  7. Determination of nickel by flame atomic-absorption spectrophotometry after separation by adsorption of its nioxime complex on microcrystalline naphthalene.

    PubMed

    Nagahiro, T; Puri, B K; Katyal, M; Satake, M

    1984-11-01

    A method has been developed for the determination of nickel in alloys by flame atomic-absorption spectrophotometry after formation of a water-insoluble complex, its adsorption on microcrystalline naphthalene, and dissolution of the complex and naphthalene in nitric acid and xylene.

  8. Hydrogen atom temperature measured with wavelength-modulated laser absorption spectroscopy in large scale filament arc negative hydrogen ion source

    SciTech Connect

    Nakano, H. Goto, M.; Tsumori, K.; Kisaki, M.; Ikeda, K.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Nishiyama, S.; Sasaki, K.

    2015-04-08

    The velocity distribution function of hydrogen atoms is one of the useful parameters to understand particle dynamics from negative hydrogen production to extraction in a negative hydrogen ion source. Hydrogen atom temperature is one of the indicators of the velocity distribution function. To find a feasibility of hydrogen atom temperature measurement in large scale filament arc negative hydrogen ion source for fusion, a model calculation of wavelength-modulated laser absorption spectroscopy of the hydrogen Balmer alpha line was performed. By utilizing a wide range tunable diode laser, we successfully obtained the hydrogen atom temperature of ∼3000 K in the vicinity of the plasma grid electrode. The hydrogen atom temperature increases as well as the arc power, and becomes constant after decreasing with the filling of hydrogen gas pressure.

  9. Atomic Absorption Spectrometry Analysis of Trace Elements in Degenerated Intervertebral Disc Tissue

    PubMed Central

    Kubaszewski, Łukasz; Zioła-Frankowska, Anetta; Frankowski, Marcin; Nowakowski, Andrzej; Czabak-Garbacz, Róża; Kaczmarczyk, Jacek; Gasik, Robert

    2014-01-01

    Background Few studies have investigated trace elements (TE) in human intervertebral disc (IVD) tissue. Trace element presence can have diverse meanings: essential TE show the metabolic modalities of the tissue, while environmentally-related TE indicate pollution and tissue-specific absorption and accumulation. IVD is a highly specific compartment with impaired communication with adjacent bone. Analysis of TE in IVD provides new insights regarding tissue metabolism and IVD communication with other tissues. Material/Methods Thirty intervertebral discs were acquired from 22 patients during surgical treatment for degenerative disease. Atomic absorption spectrometry was used to evaluate the concentrations of Al, Cd, Pb, Cu, Ni, Mo, Mg, and Zn. Results Al, Pb, Cu, Mg, and Zn were detected in all samples. Pb was significantly positively correlated with age, and Ni concentration was weakly correlated with population count in the patient’s place of residence. Only Cu was observed in higher concentrations in IVD compared to in other tissues. Significant positive correlations were observed between the following pairs: Mg/Zn, Mg/Al, Mg/Pb, Zn/Al, Zn/Pb, and Al/Pb. Negative correlations were observed between Mg/Cd, Zn/Cd, Mg/Mo, and Mo/Pb. Conclusions This study is one of few to profile the elements in intervertebral discs in patients with degenerative changes. We report significant differences between trace element concentrations in intervertebral discs compared to in other tissues. Knowledge of the TE accumulation pattern is vital for better understanding intervertebral disc nutrition and metabolism. PMID:25366266

  10. [Efficiency of hemoperfusion on clearing thallium based on atomic absorption spectrometry].

    PubMed

    Tian, Tian; Wang, Yongan; Nie, Zhiyong; Wang, Jiao; Peng, Xiaobo; Yuan, Ye; Li, Wanhua; Qiu, Zewu; Xue, Yanping; Xiong, Yiru

    2015-04-01

    To determine thallium in whole blood by atomic absorption detection method, and to investigate the eliminating effect of hemoperfusion (HP) for thallium in blood. The blood of Beagle dogs which had not exposed to thallium before were obtained for preparation of thallium nitrate ( TlNO3 )-containing solution in three concentrations according to the conversion formula based on animal weight and volume of blood. HP was performed in the simulated in vivo environment. The content of TlNO3 in blood of the next group was determined on the amount of TlNO3 for the last HP of the former dose group. Thallium quantity in different samples was measured with atomic absorption spectrometer blood samples before and after HP. Finally, the thallium concentration in blood was analyzed statistically. Thallium concentrations showed a good linear relationship in the range of 0-200 μg/L (r = 0.998 4). The intra-day precision (RSD) was lower than 4.913%, the intra-day recovery rate was 96.2%-111.9%; the inter-day precision (RSD) was lower than 7.502%, the inter-day recovery rate was 89.6%-105.2%. The concentration of thallium in blood was significantly reduced after HP per time in high, middle, and low dose groups [(453.43 ± 27.80) mg/L to (56.09 ± 14.44) mg/L in high dose group, F = 8.820, P = 0.003; (64.51 ± 13.60) mg/L to (3.19 ± 0.23) mg/L in middle dose group, F = 36.312, P = 0.000; (5.40 ± 0.98) mg/L to (0.38 ± 0.25) mg/L in low dose group, F = 46.240, P = 0.000 ]. The adsorption rate of four times of HP in high, middle and low dose group were (87.63 ± 2.48 )%, (95.06 ± 1.54 )% and (92.76 ± 4.87)%, respectively, without significant difference (F = 4.231, P = 0.070). The method for measuring thallium was established, and it shows a very stable, simple, sensitive for determination of thallium. HP can effectively remove thallium from blood. Thallium concentration can be reduced by 90% after four times of HP. HP is also effective even when thallium concentration is not high.

  11. [Determination of nine mineral elements in hulless barley by ultraviolet spectrophotometry and flame atomic absorption spectrometry].

    PubMed

    Liu, Jin; Zhang, Huai-Gang

    2010-04-01

    The contents of nine mineral elements, including sulphur, zinc, calcium, magnesium, potassium, sodium, iron, copper and manganese in five hulless barley (Hordeum vulgare L. var. nudum Hook. f.) lines were determined by ultraviolet spectrophotometry and flames atomic absorption spectrometry (FAAS). For the determination of sulphur, the samples were dissolved by magnesia and anhydrous sodium carbonate at 250 degrees C for 0. 5 h and at 550 degrees C for 3 h in the muffle furnace, and then a certain amount of barium chloride was put into the sample solution for colorimetry of the UV-Vs spectrophotometer. For the determination of other eight mineral elements, all of the samples were dissolved by a kind of incinerating method: first, the sample was put into the muffle furnace at 250 degrees C for 0. 5 h and at 550 degrees C for 2.5 h, then two droplets of 50%HNO3 were distributed into each sample, and the last step was putting the sample into the muffle furnace at 550 degrees C for 0.5 h. And then all of the ash was dissolved by 50%HNO3 to 50 milliliter and determined by flames atomic absorption spectrometry. The precision, accuracy, repeatability and stability of the method were discussed too. The results showed that the relative standard deviations (RSD) were between 1.2% and 3.7%; The average recoveries were 97.44%-101.52% and the relative standard deviations (RSD) of sample determination were 1.3%-3.8%. The repeatability experiment showed that the relative standard deviations (RSD) were 2.6%-6.1%. And the content of each mineral element was the same after 24 hours; All these showed that the method has a good precision, accuracy, repeatability and stability. In all the hulless barley samples, the average contents were in the order of K > S > Mg > Ca > Fe > Na > Zn > Mn > Cu, and the contents of zinc, iron and manganese closely related to people's health were relatively higher than other crops. The data of the experiment could provide an accurate and credible evidence

  12. Off-resonant squeezed vacuum effects on a driven two-level atom: absorption and intensity harmonics

    NASA Astrophysics Data System (ADS)

    Hassan, S. S.; Frege, O. M.; Nayak, N.

    1995-07-01

    The resonance fluorescence system of a coherently driven two-level atom in the presence of a broadband squeezed vacuum field whose central frequency is not in resonance with either the driving field frequency or the atomic transition frequency is analyzed. Solutions of the Bloch equations of the system are presented in terms of continued fractions for arbitrary strength of the coherent driving field. Numerical results are presented for the first-harmonic quadrature components of the absorption spectrum and the fluorescent intensity. The effects of the squeezed vacuum field detuning on the absorption spectrum result in hole burning or a dip structure in the weak-field case and two absorption-amplification peaks in the strong-field case. Results are sensitive to the relative phase of the squeezed vacuum.

  13. Determination of mercury in hair: Comparison between gold amalgamation-atomic absorption spectrometry and mass spectrometry.

    PubMed

    Domanico, Francesco; Forte, Giovanni; Majorani, Costanza; Senofonte, Oreste; Petrucci, Francesco; Pezzi, Vincenzo; Alimonti, Alessandro

    2017-09-01

    Mercury is a heavy metal that causes serious health problems in exposed subjects. The most toxic form, i.e., methylmercury (MeHg), is mostly excreted through human hair. Numerous analytical methods are available for total Hg analysis in human hair, including cold vapour atomic fluorescence spectrometry (CV-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). The aim of the study was to compare the TDA-AAS with the ICP-MS in the Hg quantification in human hair. After the washing procedure to minimize the external contamination, from each hair sample two aliquots were taken; the first was used for direct analysis of Hg by TDA-AAS and the second was digested for Hg determination by the ICP-MS. Results indicated that the two data sets were fully comparable (median; TDA-AAS, 475ngg(-1); ICP-MS, 437ngg(-1)) and were not statistically different (Mann-Whitney test; p=0.44). The two techniques presented results with a good coefficient of correlation (r=0.94) despite different operative ranges and method limits. Both techniques satisfied internal performance requirements and the parameters for method validation resulting sensitive, precise and reliable. Finally, the use of the TDA-AAS can be considered instead of the ICP-MS in hair analysis in order to reduce sample manipulation with minor risk of contamination, less time consuming due to the absence of the digestion step and cheaper analyses. Copyright © 2016 Elsevier GmbH. All rights reserved.

  14. High purity polyimide analysis by solid sampling graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Santos, Rafael F.; Carvalho, Gabriel S.; Duarte, Fabio A.; Bolzan, Rodrigo C.; Flores, Erico M. M.

    2017-03-01

    In this work, Cr, Cu, Mn, Na and Ni were determined in high purity polyimides (99.5%) by solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) using Zeeman effect background correction system with variable magnetic field, making possible the simultaneous measurement at high or low sensitivity. The following analytical parameters were evaluated: pyrolysis and atomization temperatures, feasibility of calibration with aqueous solution, linear calibration range, sample mass range and the use of chemical modifier. Calibration with aqueous standard solutions was feasible for all analytes. No under or overestimated results were observed and up to 10 mg sample could be introduced on the platform for the determination of Cr, Cu, Mn, Na and Ni. The relative standard deviation ranged from 3 to 20%. The limits of detection (LODs) achieved using the high sensitivity mode were as low as 7.0, 2.5, 1.7, 17 and 0.12 ng g- 1 for Cr, Cu, Mn, Na and Ni, respectively. No addition of chemical modifier was necessary, except for Mn determination where Pd was required. The accuracy was evaluated by analyte spike and by comparison of the results with those obtained by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry after microwave-assisted digestion in a single reaction chamber system and also by neutron activation analysis. No difference among the results obtained by SS-GFAAS and those obtained by alternative analytical methods using independent techniques. SS-GFAAS method showed some advantages, such as the determination of metallic contaminants in high purity polyimides with practically no sample preparation, very low LODs, calibration with aqueous standards and determination in a wide range of concentration.

  15. Mapping atomic and diffuse interstellar band absorption across the Magellanic Clouds and the Milky Way

    NASA Astrophysics Data System (ADS)

    Bailey, Mandy; van Loon, Jacco Th.; Sarre, Peter J.; Beckman, John E.

    2015-12-01

    Diffuse interstellar bands (DIBs) trace warm neutral and weakly ionized diffuse interstellar medium (ISM). Here we present a dedicated, high signal-to-noise spectroscopic survey of two of the strongest DIBs, at 5780 and 5797 Å, in optical spectra of 666 early-type stars in the Small and Large Magellanic Clouds, along with measurements of the atomic Na I D and Ca II K lines. The resulting maps show for the first time the distribution of DIB carriers across large swathes of galaxies, as well as the foreground Milky Way ISM. We confirm the association of the 5797 Å DIB with neutral gas, and the 5780 Å DIB with more translucent gas, generally tracing the star-forming regions within the Magellanic Clouds. Likewise, the Na I D line traces the denser ISM whereas the Ca II K line traces the more diffuse, warmer gas. The Ca II K line has an additional component at ˜200-220 km s-1 seen towards both Magellanic Clouds; this may be associated with a pan-Magellanic halo. Both the atomic lines and DIBs show sub-pc-scale structure in the Galactic foreground absorption; the 5780 and 5797 Å DIBs show very little correlation on these small scales, as do the Ca II K and Na I D lines. This suggests that good correlations between the 5780 and 5797 Å DIBs, or between Ca II K and Na I D, arise from the superposition of multiple interstellar structures. Similarity in behaviour between DIBs and Na I in the Small Magellanic Cloud (SMC), Large Magellanic Cloud (LMC) and Milky Way suggests the abundance of DIB carriers scales in proportion to metallicity.

  16. Simultaneous determination of manganese and selenium in serum by electrothermal atomic absorption spectrometry.

    PubMed

    Correia, Paulo R M; de Oliveira, Elisabeth; Oliveira, Pedro V

    2002-05-24

    A method for determination of manganese and selenium in serum by simultaneous atomic absorption spectrometry (SIMAAS) is proposed. The samples (30 mul) were diluted (1+3) to 1.0% v/v HNO(3)+0.10% w/v Triton X-100 directly in the autosampler cups. A total of 20 mug Pd+10 mug Mg(NO(3))(2) was used as chemical modifier. The pyrolysis and atomization temperatures for the simultaneous heating program were 1200 and 2300 degrees C, respectively. The addition of an oxidant mixture (15% w/w H(2)O(2)+1.0% v/v HNO(3)) and the inclusion of a low temperature pyrolysis step (400 degrees C) attenuated the build-up of carbonaceous residues onto the integrated platform. An aliquot of 15 mul of the reference or sample solution was introduced into the graphite tube and heated at 80 degrees C; subsequently, 10 mul of oxidant mixture+10 mul of chemical modifier was introduced over that aliquot and the remaining heating program steps were executed. This strategy allowed at least 250 heating cycles for each THGA tube without analytical signal deterioration. The characteristic masses for manganese (6 pg) and selenium (46 pg) were estimated from the analytical curves. The detection limits were 6.5 pg (n=20, 3delta) for manganese and 50 pg (n=20, 3delta) for selenium. The reliability of the entire procedure was checked with the analysis of serum from Seronormtrade mark Trace Elements in Serum (Sero AS) and by addition and recovery tests (97+/-9% for manganese and 96+/-7% for selenium) using five serum samples.

  17. Optimized determination of iron in grape juice, wines, and other alcoholic beverages by atomic absorption spectrometry.

    PubMed

    Olalla, M; Cruz González, M; Cabrera, C; López, M C

    2000-01-01

    This paper describes a study of the different methods of sample preparation for the determination of iron in grape juice, wines, and other alcoholic beverages by atomic absorption spectrometry with electrothermal atomization; results are also reported for the practical application of these methods to the analysis of commercial samples produced in Spain. The methods examined include dealcoholization and dry and wet mineralization treatment using different acids and/or mixtures of them, both with and without heating. The sensitivity, detection limit, accuracy, precision, and selectivity of each method were established. The best results were obtained for wet mineralization with heated acid (HNO3-H2SO4); the results for table wines had an accuracy of 97.5-101.6%, a relative standard deviation of 3.51%, a detection limit of 19.2 micrograms/L, and a determination limit of 32.0 micrograms/L. The method was also sufficiently sensitive and selective. It was applied to the determination of iron in grape juice, different types of wines, and beverages with high alcoholic content, all of which are produced and widely consumed in Spain. The values obtained ranged from 3.394 +/- 2.15 mg/L for the juice, 2.938 +/- 1.47 mg/L for the white wines, 19.470 +/- 5.43 mg/L for the sweet wines, 0.311 +/- 0.07 mg/L for the brandies, and 0.564 +/- 0.12 mg/L for the anisettes. Thus, the method is useful for routine analysis in the quality control of these beverages.

  18. Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

    NASA Astrophysics Data System (ADS)

    Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

    2016-01-01

    A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

  19. Absorption spectrum of an atom strongly coupled to a high-temperature reservoir

    NASA Astrophysics Data System (ADS)

    Kofman, A. G.

    2005-03-01

    We study the absorption spectrum of a weak probe field near resonant to an atomic transition, the upper level of which is strongly coupled to a third level by the interaction with a Lorentzian bosonic reservoir, such as, e.g., a mode of a high- Q cavity or a local vibration in a solid. The reservoir coupling is approximated by the interaction with a classical complex Gaussian-Markovian random process (control field), which is justified when the reservoir temperature exceeds significantly the mode frequency or when the high- Q cavity is pumped by broadband incoherent radiation. The present theory is applicable also when the control field is chaotic laser light. We assume that the rms control-field Rabi frequency V0 is much greater than the field detuning Δc , which, in turn, is much greater than the material relaxation constants. We reveal and describe analytically all qualitatively different regimes of the spectrum modification and obtain their validity conditions. The analytical results are verified by numerical calculations using the exact continued-fraction solution. The analytical formulas obtained allow one to perform fast computer calculations for arbitrarily small values of the reservoir (control-field) bandwidth ν , in contrast to the known numerical methods, which require sharply increasing computational resources with a decrease of ν . In the most interesting case ν≪V0 , the spectrum consists of two peaks, the nonvanishing bandwidth and material relaxation affecting mainly the dip between the peaks. The results obtained in the static limit (i.e., a very narrow reservoir) are independent of the reservoir band shape. We reveal reservoir-induced transparency (RIT)—i.e., absorption reduction due to the reservoir coupling. Moreover, two unexpected, remarkable features are uncovered in a range of intermediate values of ν and V0 , Γ2∣Δc∣≪V02ν≪∣Δc∣3 ( Γ is the spectral width in the absence of the control field): an extra peak in the dip

  20. Role of a binary metallic modifier in the determination of cadmium in graphite furnace atomic absorption spectrometry.

    PubMed

    Morimoto, Syun; Ashino, Tetsuya; Wagatsuma, Kazuaki

    2010-01-01

    In order to discuss the matrix modifier effect of palladium, iron, and a mixture of palladium and iron for the determination of cadmium in graphite-furnace atomic absorption spectrometry (GF-AAS), we measured the absorption profiles of a cadmium line at various compositions of these elements. Variations in the gas temperature were also estimated with the progress of atomization, by using a two-line method under the assumption of a Boltzmann distribution. The atomic absorption of cadmium appeared on the way of heating from the charring temperature to the atomizing temperature while the gas temperature was still low; it was thus considered that cadmium was atomized through direct conductive heating from the wall of the graphite furnace. Therefore, the effectiveness of modifiers for cadmium would be determined through any reactions on the furnace wall at the programmed charring and atomizing temperatures. The addition of iron, palladium, and an iron-palladium mixture all enhanced the absorption signal of cadmium compared to a pure cadmium sample; however, their effects were different from one another. Each addition of iron or palladium to the sample solution led to an enhancement of the cadmium absorbance, indicating that iron or palladium individually became an effective matrix modifier for the determination of cadmium. However, the addition of palladium was ineffective for the matrix modification in the coexistence of large amounts of iron. Although these phenomena are very complicated, and thus cannot be understood completely, any metallurgical reaction between the constituent elements during heating of the furnace wall, such as the formation of solid solutions and intermetallic compounds, would cause the effect of a matrix modifier in GF-AAS.

  1. [Atomic absorption spectrophotometry study of copper ion release by copper-bearing intrauterine devices].

    PubMed

    Berthou, J; Chrétien, F C; Driguez, P A

    1998-11-01

    Copper release from copper-bearing IUD's was studied in vitro and in vivo using atomic absorption spectrophotometry in deionized water, normal saline solution and normal ovulatory cervical mucus. In these media, copper release from a 375 mm2 DIU occurs without latency, showing comparable amounts for identical time intervals. Daily copper release was shown to be respectively 8 and 11 times higher in cervical mucus and normal saline solution than in deionized water. Although copper ions are detectable in ovulatory cervical mucus under physiological conditions, the copper content appears 5 to 6 times higher in women bearing a copper IUD. Obviously, the copper amount is dependent on the copper exposed surface: the daily in vitro release from a 250 mm2 IUD is 18% inferior to that observed from a 375 mm2 model. In vivo, the daily copper release in ovulatory mucus of 380 or 200 mm2 IUD users is respectively 5 and 3.5 times higher than in controls.

  2. Improved preparation of small biological samples for mercury analysis using cold vapor atomic absorption spectroscopy.

    PubMed

    Adair, B M; Cobb, G P

    1999-05-01

    Concentrations of mercury in biological samples collected for environmental studies are often less than 0.1 microgram/g. Low mercury concentrations and small organ sizes in many wildlife species (approximately 0.1 g) increase the difficulty of mercury determination at environmentally relevant concentrations. We have developed a digestion technique to extract mercury from small (0.1 g), biological samples at these relevant concentrations. Mean recoveries (+/- standard error) from validation trials of mercury fortified tissue samples using cold vapor atomic absorption spectroscopy for analysis ranged from 102 +/- 4.3% (2.5 micrograms/L, n = 15) to 108 +/- 1.4% (25 micrograms/L, n = 15). Recoveries of inorganic mercury were 99 +/- 5 (n = 19) for quality assurance samples analyzed during environmental evaluations conducted during a 24 month period. This technique can be used to determine total mercury concentrations of 60 ng Hg/g sample. Samples can be analyzed in standard laboratories in a short time, at minimal cost. The technique is versatile and can be used to determine mercury concentrations in several different matrices, limiting the time and expense of method development and validation.

  3. Detection of Glucose with Atomic Absorption Spectroscopy by Using Oligonucleotide Functionalized Gold Nanoparticle.

    PubMed

    Zhang, Hong; Yan, Honglian; Ling, Liansheng

    2016-06-01

    A novel method for the detection of glucose was established with atomic absorption spectroscopy by using the label of gold nanoparticle (AuNP). Silver-coated glass assembled with oligonucleotide 5'-SH-T12-AGA CAA GAG AGG-3' (Oligo 1) was acted as separation probe, oligonucleotide 5'-CAA CAG AGA ACG-T12-SH-3' modified gold nanoparticle (AuNP-Oligo 2) was acted as signal-reporting probe. Oligonucleotide 5'-CGT TCT CTG TTG CCT CTC TTG TCT-3' (Oligo 3) could hybridize with Oligo 1 on the surface of silver-coated glass and AuNP-Oligo 2, and free AuNP-Oligo 2 could be removed by rinsing with buffer. Hence the concentration of Oligo 3 was transformed into the concentration of gold element. In addition, Oligo 3 could be cleaved into DNA fragments by glucose, glucose oxidase and Fe(2+)-EDTA through Fenton reaction. Thereby the concentration of glucose could be transformed to the absorbance of gold element. Under the optimum conditions, the integrated absorbance decreased proportionally to the concentration of glucose over the range from 50.0 μM to 1.0 mM with a detection limit of 40.0 μM. Moreover, satisfactory result was obtained when the assay was used to determinate glucose in human serum.

  4. Determination of firing distance. Lead analysis on the target by atomic absorption spectroscopy (AAS).

    PubMed

    Gagliano-Candela, Roberto; Colucci, Anna P; Napoli, Salvatore

    2008-03-01

    This paper reports a method for the determination of the firing distance. Atomic absorption spectroscopy (AAS) was used to determine the lead (Pb) pattern around bullet holes produced by shots on test targets from the gun. Test shots were made with a Colt 38 Special at 5, 10, 20, 25, 30, 35, 40, 45, 50, 60, 80, and 100 cm target distance. The target was created with sheets of Whatman no. 1 paper on a polystyrene support. The target was subdivided into three carefully cut out rings (1, 2, and 3; with external diameters of 1.4 cm; 5 cm; 10.2 cm, respectively). Each sample was analyzed with graphite furnace AAS. Lead values analysis performed for each ring yielded a linear relation between the firing distance (cm) and the logarithm of lead amounts (microg/cm(2)) in definite target areas (areas 2 + 3): [ln dPb(2+3) = a(0) + a(1)l]; where dPb(2+3) = lead microg/cm(2) of area 2 + 3; a(0) and a(1) are experimentally calculated; l = distance in cm.

  5. Measurement of nickel, cobalt and chromium in toy make-up by atomic absorption spectroscopy.

    PubMed

    Corazza, Monica; Baldo, Federica; Pagnoni, Antonella; Miscioscia, Roberta; Virgili, Annarosa

    2009-01-01

    Cosmetics should not contain more than 5 ppm of nickel, chromium or cobalt and, in order to minimize the risk of sensitization in very sensitive subjects, the target amount should be as low as 1 ppm. However, there are no published reports on the presence of these metals in toy make-up. This study analysed 52 toy make-ups using atomic absorption spectroscopy. More than 5 ppm of nickel was present in 14/52 (26.9%) samples. Chromium exceeded 5 ppm in 28/52 (53.8%) samples, with values over 1000 ppm in 3 eye shadows. Cobalt was present in amounts over 5 ppm in 5/52 (9.6%) samples. Powdery toy make-up (eye shadows) had the highest levels of metals, and "creamy" toy make-up (lip gloss and lipsticks) the lowest. Toy make-ups are potentially sensitizing items, especially for atopic children, who have a damaged skin barrier that may favour penetration of allergens.

  6. Stabilizing Agents for Calibration in the Determination of Mercury Using Solid Sampling Electrothermal Atomic Absorption Spectrometry

    PubMed Central

    Zelinková, Hana; Červenka, Rostislav; Komárek, Josef

    2012-01-01

    Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L−1 TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants. PMID:22654606

  7. Determination of nickel, chromium and cobalt in wheat flour using slurry sampling electrothermal atomic absorption spectrometry.

    PubMed

    González, M; Gallego, M; Valcárcel, M

    1999-05-01

    The slurry technique was applied to the determination of Ni, Cr and Co in wheat flour by electrothermal atomic absorption spectrometry (ETAAS). The influence of the graphite furnace temperature programme was optimized. Optimum sensitivity was obtained by using a mixture of 15% HNO(3)-10% H(2)O(2) as suspended medium for a 3% w/v slurry in the determination of Ni; lower concentrations of HNO(3) were necessary for the determination of Co and Cr (viz. 5 and 10%). The precision of direct analyses of the slurries was improved by using mechanical agitation between measurements; thus, the RSD of the measurements was ca. 5% for repeatability. The direct slurry sampling (SS) technique is suitable for the determination of Ni and Cr in wheat flour samples at levels of 150-450 and 30-72 ng g(-1), respectively, as it provides results similar to those obtained by ashing the sample. However, the typically low level of Co in these samples precluded its determination by the proposed method (the study was made in an SRM spiked wholemeal flour), at least in those samples that were contaminated with elevated concentrations of the metal (viz. more than 90 ng of Co per g of flour). The method provides a relative standard deviation of 6, 8, and 4% for Ni, Cr, and Co, respectively.

  8. Column preconcentration and electrothermal atomic absorption spectrometric determination of rhodium in some food and standard samples.

    PubMed

    Taher, Mohammad Ali; Pourmohammad, Fatemeh; Fazelirad, Hamid

    2015-12-01

    In the present work, an electrothermal atomic absorption spectrometric method has been developed for the determination of ultra-trace amounts of rhodium after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol/tetraphenylborate ion associated complex at the surface of alumina. Several factors affecting the extraction efficiency such as the pH, type of eluent, sample and eluent flow rates, sorption capacity of alumina and sample volume were investigated and optimized. The relative standard deviation for eight measurements of 0.1 ng/mL of rhodium was ±6.3%. In this method, the detection limit was 0.003 ng/mL in the original solution. The sorption capacity of alumina and the linear range for Rh(III) were evaluated as 0.8 mg/g and 0.015-0.45 ng/mL in the original solution, respectively. The proposed method was successfully applied for the extraction and determination of rhodium content in some food and standard samples with high recovery values.

  9. [Determination of trace elements in new food sources by flame atomic absorption spectrophotometry].

    PubMed

    Liu, Li E; Ding, Li; Qi, Min; Han, Xiu Li; Zhang, Hong-Quan

    2007-07-01

    Samples were digested by HNO3 + HClO4. Flame atomic absorption spectrophotometry (FAAS) was successfully used to determine copper, zinc and iron in new resource food. Under our experimental conditions, the recovery ratio was 94.66%-108.80%; the precision was 0.71%-4.78%. This method of measuring elements is convenient, rapid and accurate. The results showed that there are profitable elements, such as copper, zinc and iron in new resourse food in Henan province. By F test and SNK test, the content sequence of metal elements was found as follows: copper, Chrysanthemum morifolium Ramat = Silkworm pupa > flowers of Pueraria lobata Ohwin = Wheat germ = Codonopsis lanceolata = roots of Pueraria lobata Ohwi > Opuntia dillenii Haw. Zinc, Opuntia dillenii Haw > Silkworm pupa = flowers of Pueraria lobata Ohwi = roots of Pueraria lobata Ohwi = Wheat germ = Codonopsis lanceolata = Chrysanthemum morifolium Ramat. Iron, Silkworm pupa = C hrysanthemum morifolium Ramat = roots of Pueraria lobata Ohwi > flowers of Pueraria lobata Ohwi = Wheat germ = Codonopis lanceolata = Opuntia dillenii Haw.

  10. Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

    USGS Publications Warehouse

    Elsheimer, H.N.; Fries, T.L.

    1990-01-01

    A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

  11. [Determination of soil exchangeable base cations by using atomic absorption spectrophotometer and extraction with ammonium acetate].

    PubMed

    Zhang, Yu-ge; Xiao, Min; Dong, Yi-hua; Jiang, Yong

    2012-08-01

    A method to determine soil exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) by using atomic absorption spectrophotometer (AAS) and extraction with ammonium acetate was developed. Results showed that the accuracy of exchangeable base cation data with AAS method fits well with the national standard referential soil data. The relative errors for parallel samples of exchangeable Ca and Mg with 66 pair samples ranged from 0.02%-3.14% and 0.06%-4.06%, and averaged to be 1.22% and 1.25%, respectively. The relative errors for exchangeable K and Na with AAS and flame photometer (FP) ranged from 0.06%-8.39% and 0.06-1.54, and averaged to be 3.72% and 0.56%, respectively. A case study showed that the determination method for exchangeable base cations by using AAS was proven to be reliable and trustable, which could reflect the real situation of soil cation exchange properties in farmlands.

  12. Germanium determination by flame atomic absorption spectrometry: an increased vapor pressure-chloride generation system.

    PubMed

    Kaya, Murat; Volkan, Mürvet

    2011-03-15

    A new chloride generation system was designed for the direct, sensitive, rapid and accurate determination of the total germanium in complex matrices. It was aimed to improve the detection limit of chloride generation technique by increasing the vapor pressure of germanium tetrachloride (GeCl(4)). In order to do so, a novel joint vapor production and gas-liquid separation unit equipped with a home-made oven was incorporated to an ordinary nitrous oxide-acetylene flame atomic absorption spectrometer. Several variables such as reaction time, temperature and acid concentration have been investigated. The linear range for germanium determination was 0.1-10 ng mL(-1) for 1 mL sampling volume with a detection limit (3s) of 0.01 ng mL(-1). The relative standard deviation (RSD) was 2.4% for nine replicates of a 1 ng mL(-1) germanium solution. The method was validated by the analysis of one non-certified and two certified geochemical reference materials, respectively, CRM GSJ-JR-2 (Rhyolite), and GSJ-JR-1 (Rhyolite), and GBW 07107 (Chinese Rock). Selectivity of the method was investigated for Cd(2+), Co(2+), Cu(2+), Fe(3+), Ga(3+), Hg(2+), Ni(2+), Pb(2+), Sn(2+), and Zn(2+) ions and ionic species of As(III), Sb(III), Te(IV), and Se(IV).

  13. Determination of Mo and V in multiphase gasoline emulsions by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Santana Sodré dos Santos, Denilson; Paixão Teixeira, Alete; das Graças Andrade Korn, Maria; Sena Gomes Teixeira, Leonardo

    2006-05-01

    This paper proposes an alternative analytical method using electrothermal atomic absorption spectrometry to determine Mo and V in multiphase gasoline emulsions. Samples were prepared by mixing gasoline with a nitric acid solution (0.1% v/v) and two cationic surfactants. The mixture was sonicated, resulting in an emulsive system. Calibration was done by using the aforementioned solutions with added analyte. The detection limits (3 σ) of Mo and V were 0.9 μg l - 1 and 4.7 μg l - 1 , respectively. The accuracy and precision of the proposed method were evaluated by the analysis of samples spiked with metallo-organic standard and the relative standard deviation obtained ranged from 1.2% to 4.4% in samples spiked with 2 μg l - 1 of each metal. The recovery rates varied from 91.2% to 101.6%. The proposed method was applied to determine Mo and V in samples of gasoline from different gas stations.

  14. Comparative study of heavy metals in dried and fluid milk in Peshawar by atomic absorption spectrophotometry.

    PubMed

    Lutfullah, Ghosia; Khan, Abid Ali; Amjad, Azra Yasmeen; Perveen, Sajida

    2014-01-01

    Various essential and toxic heavy metals (Ca, Mg, Cu, Zn, Fe, Mn, Pb, Cd, Cr, and Ni) contents in various types of dried (infant formula and powdered) and fluid (fresh and processed) cow milk were assessed by atomic absorption spectrophotometry. The milk samples were collected from local markets of different parts of Peshawar city, Pakistan. Heavy metal concentrations varied significantly depending upon the type of milk. The heavy metal concentrations in most of the samples were within normal and permissible ranges. It was observed that the samples contained considerable amounts of calcium, while magnesium levels were well above the required levels. The results also revealed that copper levels were slightly lower than the permissible limits. The concentration of zinc in dried milk samples was greater than the values for the liquid milk types. Infant milk formulae had higher iron levels as compared to other milk samples because of the added constituents. Significant differences were observed in the mean values of manganese and cadmium in different types of milk. The toxic metals were within the acceptable limits and did not show significant levels leading to toxicity.

  15. Atomic absorption spectrometric determination of copper, zinc, and lead in geological materials

    USGS Publications Warehouse

    Sanzolone, R.F.; Chao, T.T.

    1976-01-01

    An atomic absorption spectrometric method is described for the determination of copper, zinc, and lead in geological materials. The sample is digested with HF-HCl-H2O2; the final solution for analysis is in 10 % (v/v) HCl. Copper and zinc are determined directly by aspirating the solution into an air-acetylene flame. A separate aliquot of the solution is used for determination of lead; lead is extracted into TOPO-MIBK from the acidic solution in the presence of iodide and ascorbic acid. For a 0.50-g sample, the limits of determination are 10-2000 p.p.m. for Cu and Zn, and 5-5000 p.p.m. for Pb. As much as 40 % Fe or Ca. and 10 % Al, Mg, or Mn in the sample do not interfere. The proposed method can be applied to the determination of copper, zinc, and lead in a wide range of geological materials including iron- and manganese-rich, calcareous and carbonate samples. ?? 1976.

  16. Speciation of methylmercury in market seafood by thermal degradation, amalgamation and atomic absorption spectroscopy.

    PubMed

    Ruiz-de-Cenzano, Manuela; Rochina-Marco, Arancha; Cervera, M Luisa; de la Guardia, Miguel

    2014-09-01

    Sample thermal decomposition followed by mercury amalgamation and atomic absorption has been employed for the determination of methylmercury (MeHg) in fish. The method involves HBr leaching of MeHg, extraction into toluene, and back-extraction into an aqueous l-cysteine solution. Preliminary studies were focused on the extraction efficiency, losses, contaminations, and species interconversion prevention. The limit of detection was 0.018µgg(-1) (dry weight). The intraday precision for three replicate analysis at a concentration of 4.2µgg(-1) (dry weight) was 3.5 percent, similar to the interday precision according to analysis of variance (ANOVA). The accuracy was guaranteed by the use of fortified samples involving 83-105 percent recoveries, and certified reference materials TORT-2 (lobster hepatopancreas) and DORM-3 (dogfish liver), providing 107 and 98 percent recovery of certified values. The greenness of the method was also evaluated with the analytical eco-scale being obtained a final score of 73 points which means an acceptable green analysis. The method was applied to fifty-seven market samples of different fish acquired from local markets in several sampling campaigns. The content of MeHg found varied between 0.0311 and 1.24µgg(-1) (wet weight), with values that involve 33-129 percent of the total mercury content. Some considerations about food safety were also done taking into account data about Spanish fish consume and Tolerable Weekly Intake (TWI) established for MeHg.

  17. [Determination of rubidium and cesium in chloride type oilfield water by flame atomic absorption spectrometry].

    PubMed

    Ye, Xiu-Shen; Zhang, Shan-Ying; Li, Hai-Jun; Li, Wu; Wu, Zhi-Jian

    2009-03-01

    Flame atomic absorption spectrometry (FAAS) was applied to the determination of rubidium and cesium in chloride type oilfield water by considering the interferences of the coexistent K+, Na+, Ca2+, and Mg2+ ions, Standard curve method and standard addition method were compared in the determination of rubidium and cesium in the simulated oilfield water and the real oilfield water from the Nanyishan region in Qaidam Basin. Although rubidium and cesium have similar physical-chemical properties, they present different characters during their analyses using the FAAS technique. When the standard addition method was used for the determination of rubidium and cesium in the simulated oilfield water, the results of rubidium were very poor, whereas the results of cesium were satisfactory. When the standard curve method was used for the determination of rubidium and cesium in the simulated oilfield water, the results of both rubidium and cesium were satisfactory within the linear ranges of the standard curves. For the real oilfield water, standard addition method is also only applicable for the determination of cesium with a recovery ranging from 90% to 110%. While standard curve method is applicable for the determination of both rubidium and cesium with a recovery ranging from 90% to 110%.

  18. Atomic Structure of Pt3Ni Nanoframe Electrocatalysts by in Situ X-ray Absorption Spectroscopy.

    PubMed

    Becknell, Nigel; Kang, Yijin; Chen, Chen; Resasco, Joaquin; Kornienko, Nikolay; Guo, Jinghua; Markovic, Nenad M; Somorjai, Gabor A; Stamenkovic, Vojislav R; Yang, Peidong

    2015-12-23

    Understanding the atomic structure of a catalyst is crucial to exposing the source of its performance characteristics. It is highly unlikely that a catalyst remains the same under reaction conditions when compared to as-synthesized. Hence, the ideal experiment to study the catalyst structure should be performed in situ. Here, we use X-ray absorption spectroscopy (XAS) as an in situ technique to study Pt3Ni nanoframe particles which have been proven to be an excellent electrocatalyst for the oxygen reduction reaction (ORR). The surface characteristics of the nanoframes were probed through electrochemical hydrogen underpotential deposition and carbon monoxide electrooxidation, which showed that nanoframe surfaces with different structure exhibit varying levels of binding strength to adsorbate molecules. It is well-known that Pt-skin formation on Pt-Ni catalysts will enhance ORR activity by weakening the binding energy between the surface and adsorbates. Ex situ and in situ XAS results reveal that nanoframes which bind adsorbates more strongly have a rougher Pt surface caused by insufficient segregation of Pt to the surface and consequent Ni dissolution. In contrast, nanoframes which exhibit extremely high ORR activity simultaneously demonstrate more significant segregation of Pt over Ni-rich subsurface layers, allowing better formation of the critical Pt-skin. This work demonstrates that the high ORR activity of the Pt3Ni hollow nanoframes depends on successful formation of the Pt-skin surface structure.

  19. Use of atomic absorption spectrometry in assessment of biomonitor plants for lead, cadmium and copper pollution.

    PubMed

    Gokce, Kaya; Mehmet, Yaman

    2012-01-01

    Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep, Turkey. Lead, cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry. Lead, Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304-602, 0.4-0.44 and 31-37 mg x kg(-1), respectively. Significantly increased lead concentration up to 2 750 mg x kg(-1) was found in the leaves of Eleagnus angustifolia L. plant. The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima > Morus sp. > Juglans regia L. > Ficus carica L. > Cydonia oblonga Miller > Prunus x domestica L. The plants, Populus nigra L. , Eleagnus angustifolia L. and Salix sp. were found useful for Cd, and the plant, Eleagnus angusti folia L. for Pb, to be considered as potential biomonitor. Especially, leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations. Therefore, people who and animals which live in this area and benefit from these soil and plants have vital risks.

  20. Determination of total gaseous lead in the atmosphere by honeycomb denuder/electrothermal atomic absorption spectrometry.

    PubMed

    Zhang, Bicheng; Wu, Tao; Yu, Jimmy C

    2005-09-01

    A technique is described for the determination of total gaseous lead in the atmosphere by honeycomb denuder collection, followed by an electrothermal atomic absorption spectrometry (ETAAS) measurement. The collection efficiency of the honeycomb denuder in which a solution containing 2% HNO3/2% glycerine/1% ammonium dihydrogenphosphate was coated for trapping the gaseous lead in the atmosphere was 98.8%. The linear absorbance response was obtained for a concentration range of 0-1.39 microg m(-3) of lead in the atmosphere. A precision of 4.8% RSD (peak-height absorbance, n = 11) for an aqueous solution of 1 ng of lead standard, characteristic masses (CM) of 23 pg and detection limit (3sigma) of 54 pg for an aqueous solution of 0.01 ng lead standard was achieved with 100 microg ammonium dihydrogenphosphate as a chemical modifier. The average recovery of lead in three standard samples prepared by the independent digestion of NIST SRM 1648 (Urban Particulate Matter) using our analytical system was 97.8%. The total content of the gaseous lead in the atmosphere of our laboratories was 0.35-0.38 microg m(-3).

  1. Arsenic speciation in natural water samples by coprecipitation-hydride generation atomic absorption spectrometry combination.

    PubMed

    Tuzen, Mustafa; Citak, Demirhan; Mendil, Durali; Soylak, Mustafa

    2009-04-15

    A speciation procedure for As(III) and As(V) ions in environmental samples has been presented. As(V) was quantitatively recovered on aluminum hydroxide precipitate. After oxidation of As(III) by using dilute KMnO(4), the developed coprecipitation was applied to determination of total arsenic. Arsenic(III) was calculated as the difference between the total arsenic content and As(V) content. The determination of arsenic levels was performed by hydride generation atomic absorption spectrometry (HG-AAS). The analytical conditions for the quantitative recoveries of As(V) including pH, amount of aluminum as carrier element and sample volume, etc. on the presented coprecipitation system were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was calculated as 25. The detection limits (LOD) based on three times sigma of the blank (N: 21) for As(V) was 0.012 microg L(-1). The satisfactory results for the analysis of arsenic in NIST SRM 2711 Montana soil and LGC 6010 Hard drinking water certified reference materials for the validation of the method was obtained. The presented procedure was successfully applied to real samples including natural waters for arsenic speciation.

  2. Comparative Study of Heavy Metals in Dried and Fluid Milk in Peshawar by Atomic Absorption Spectrophotometry

    PubMed Central

    Lutfullah, Ghosia; Khan, Abid Ali; Amjad, Azra Yasmeen; Perveen, Sajida

    2014-01-01

    Various essential and toxic heavy metals (Ca, Mg, Cu, Zn, Fe, Mn, Pb, Cd, Cr, and Ni) contents in various types of dried (infant formula and powdered) and fluid (fresh and processed) cow milk were assessed by atomic absorption spectrophotometry. The milk samples were collected from local markets of different parts of Peshawar city, Pakistan. Heavy metal concentrations varied significantly depending upon the type of milk. The heavy metal concentrations in most of the samples were within normal and permissible ranges. It was observed that the samples contained considerable amounts of calcium, while magnesium levels were well above the required levels. The results also revealed that copper levels were slightly lower than the permissible limits. The concentration of zinc in dried milk samples was greater than the values for the liquid milk types. Infant milk formulae had higher iron levels as compared to other milk samples because of the added constituents. Significant differences were observed in the mean values of manganese and cadmium in different types of milk. The toxic metals were within the acceptable limits and did not show significant levels leading to toxicity. PMID:24967439

  3. [In vitro evaluation of mercury leakage from dental amalgam using atomic absorption spectrophotometry].

    PubMed

    Lugliè, P F; Filia, G; Chessa, G; Calaresu, G

    1999-06-01

    The use of silver amalgam as a tooth filler is under constant critical review because of its mercury content. After a review of the literature on this subject, in vitro spectrophotometry was used to assay the release of mercury by these amalgams in basal conditions. The experiment was conducted in two phases using standard doses of amalgam. In Phase 1 Black Class I cavities were created in extracted teeth that were big enough to take the required dose of amalgam. In some cases the material was inserted in a single operation, while in others the amalgam was introduced in three stages. Some of the cavities were cleansed with cotton buds bathed in ethyl alcohol, while others were not. All the drilled teeth were imbued in a bath of artificial saliva held at a constant temperature. In the second experiment, crushed amalgam was immersed in a similar bath of artificial saliva but otherwise untreated. The saliva was assayed after different time lapses using atomic absorption spectrophotometry and the FIAS technique. The results showed extremely variable but always modest quantities of free mercury in the artificial saliva. The findings suggest that not all the mercury available in the amalgamation phase is involved in the formation of the crystalline reticulum and that the percentage of mercury bonded is different every time. While the titre of free mercury encountered was always extremely low and hard to predict, it cannot be ignored.

  4. Monitoring of trace elements in honey from the Republic of Macedonia by atomic absorption spectrometry.

    PubMed

    Stankovska, Elena; Stafilov, Trajce; Sajn, Robert

    2008-07-01

    Contents of Zn, Cu, Fe, Mn, Cd, Na, K, Ca and Mg in 123 honey samples from different regions of the Republic of Macedonia were determined by atomic absorption spectrometry. A microwave digestion system was applied for digestion of the samples. The mean content for the elements determined was found to be: 2.252, 0.696, 1.885, 1.752, 0.004, 29.52, 984.8, 40.11, 18.24 mg kg(-1) for Zn, Cu, Fe, Mn, Cd, Na, K, Ca and Mg, respectively. Based on a comparison of statistical parameters, the spatial distribution of particular elements in Macedonian honey and the results of factor analysis, two natural and one anthropogenic geochemical associations were identified. The natural geochemical associations (Mg, Mn, Ca, K and Fe, Zn, Ca, -K, -Na) are influenced mainly by lithology. The anthropogenic associations (Cd and -Cu) are mostly a result of metallurgical activities, namely lead production in the town of Veles.

  5. Liquid phase microextraction and ultratrace determination of cadmium by modified graphite furnace atomic absorption spectrometry.

    PubMed

    Nazari, Saeid

    2009-06-15

    A powerful microextraction technique was used for determination of cadmium in water samples using liquid phase microextraction (LPME) followed by graphite furnace atomic absorption spectrometry (GF-AAS). In a preconcentration step, cadmium was extracted from a 2 ml of its aqueous sample in the pH 7 as 5,7-dibromoquinoline-8-ol (DBQ) complex into a 4 microl drop of benzyl alcohol. After extraction, the micro drop was retracted and directly transferred into a graphite tube modified by [W.Rh.Pd](c). Some effective parameters on extraction and complex formation, such as type and volume of organic solvent, pH, concentration of chelating agent, extraction time and stirring rate were optimized. Under the optimum conditions, the enrichment factor and recovery were 450% and 90%, respectively. The calibration graph was linear in the range of 0.008-1 microg L(-1) with correlation coefficient of 0.9961 under the optimum conditions of the recommended procedure. The detection limit based on the 3Sb criterion was 0.0035 microg L(-1) and relative standard deviation (RSD) for eight replicate measurement of 0.1 microg L(-1) and 0.4 microg L(-1) cadmium was 5.2% and 4.5%, respectively. The characteristic concentration was 0.0032 microg L(-1) equivalent to a characteristic mass of 12.8 fg. In order to evaluate the accuracy and recovery of the presented method the procedure was applied to the analysis of reference materials and seawater.

  6. Ion-exchange preconcentration and determination of vanadium in milk samples by electrothermal atomic absorption spectrometry.

    PubMed

    López-García, Ignacio; Viñas, Pilar; Romero-Romero, Rafael; Hernández-Córdoba, Manuel

    2009-06-15

    A new method for the electrothermal atomic absorption spectrometric determination of vanadium in milk and infant formulas using suspensions to avoid the need for previous dissolution of samples is described. Sensitivity is improved by a procedure based on preconcentration and removal of the matrix, using ion-exchange (Dowex 1X8-100). Suspensions of 15% (m/v) infant formula samples were prepared in a medium containing 0.05M sodium citrate (pH 7.2) and passed through the ion exchange column. Vanadium was eluted from the column using 1M hydrochloric acid and injected in the graphite furnace using a mixture of hydrofluoric acid plus magnesium nitrate as chemical modifiers. Calibration was carried out using multiple injection and aqueous standards prepared in the same medium. Detection limits were 0.2 ng g(-1) for infant formulas and 0.02 microg L(-1) for cow milk samples. The reliability of the procedure was checked by comparing the results obtained with those found using a previous mineralization stage and by analyzing five certified reference materials.

  7. Highly sensitive fiber grating chemical sensors: An effective alternative to atomic absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Laxmeshwar, Lata. S.; Jadhav, Mangesh S.; Akki, Jyoti. F.; Raikar, Prasad; Kumar, Jitendra; prakash, Om; Raikar, U. S.

    2017-06-01

    Accuracy in quantitative determination of trace elements like Zinc, present in drinking water in ppm level, is a big challenge and optical fiber gratings as chemical sensors may provide a promising solution to overcome the same. This paper presents design of two simple chemical sensors based on the principle of shift in characteristic wavelength of gratings with change in their effective refractive index, to measure the concentration of Zinc in drinking water using etched short period grating (FBG) and Long period grating (LPG) respectively. Three samples of drinking water from different places have been examined for presence of Zinc. Further, the results obtained by our sensors have also been verified with the results obtained by a standard method, Atomic absorption spectroscopy (AAS). The whole experiment has been performed by fixing the fibers in a horizontal position with the sensor regions at the center of the fibers, making it less prone to disturbance and breaking. The sensitivity of LPG sensor is about 205 times that of the FBG sensor. A few advantages of Fiber grating sensors, besides their regular features, over AAS have also been discussed, that make our sensors potential alternatives for existing techniques in determination of trace elements in drinking water.

  8. Determination of mercury by cold vapor atomic absorption spectrophotometer in Tongkat Ali preparations obtained in Malaysia.

    PubMed

    Ang, Hooi-Hoon; Lee, Ee-Lin; Cheang, Hui-Seong

    2004-01-01

    The DCA (Drug Control Authority), Malaysia, has implemented the phase 3 registration of traditional medicines on 1 January 1992, with special emphasis on the quality, efficacy, and safety (including the presence of heavy metals) in all pharmaceutical dosage forms of traditional medicine preparations. As such, a total of 100 products in various pharmaceutical dosage forms of a herbal preparation, containing Tongkat Ali, were analyzed for mercury content using cold vapor atomic absorption spectrophotometer. Results showed that 36% of the above products possessed 0.52 to 5.30 ppm of mercury and, therefore, do not comply with the quality requirement for traditional medicines in Malaysia. Out of these 36 products, 5 products that possessed 1.05 to 4.41 ppm of mercury were in fact have already registered with the DCA, Malaysia. However, the rest of the products that contain 0.52 to 5.30 ppm of mercury still have not registered with the DCA, Malaysia. Although this study showed that only 64% of the products complied with the quality requirement for traditional medicines in Malaysia pertaining to mercury, they cannot be assumed safe from mercury contamination because of batch-to-batch inconsistency.

  9. Extraction separation and electrothermal atomic absorption spectrometric determination of thallium in some sulfide minerals.

    PubMed

    Zendelovska, D; Stafilov, E

    2001-03-01

    A method for thallium determination in some sulfide minerals (sphalerite, galena, orpiment and realgar) by electrothermal atomic absorption spectrometry has been proposed. Mineral samples were dissolved in a mixture of HNO3 and HCl. The effect of interfering elements (Zn, Pb and As) on the determination of Tl in the investigated minerals was studied. These investigations show that it is not possible to determine thallium directly from solutions obtained by dissolution of minerals in mineral acids, because these matrix elements tend to decrease the absorbance of thallium. Also, it was found that the investigated minerals contain iron that tends to increase the absorbance of thallium. Therefore, a method for extraction of thallium with isoamyl acetate from 10 mol/l HCl media was proposed. In these conditions, Zn, Pb and As remain in the inorganic phase, but iron and thallium are extracted into organic phase. Reextraction of iron from the organic layer was performed with 4 mol/l H2SO4. The determination of thallium was performed in the organic phase using Pd as modifier. The investigated sulfide minerals originated from different mines from the Republic of Macedonia. The relative standard-deviation range was between 2.20 to 3.92%. The detection limit of the method (calculated as 3SD of the blank) was found to be 0.05 microg/g.

  10. Determination of lead in table wines by graphite furnace atomic absorption spectrometry.

    PubMed

    Mindak, W R

    1994-01-01

    A quick, easy method was developed for the analysis of table wines for lead quantitated at > or = 14 ng Pb/mL wine. The method uses graphite furnace atomic absorption spectrometry with Zeeman background correction and a L'vov pyrolytic graphite platform. Ammonium dihydrogen phosphate is used as a matrix modifier. Wines are diluted by a factor of 10 with 1% HNO3 and analyzed directly. Their absorbances are compared with those of a standard curve prepared with 1% HNO3. Analytical results obtained by comparison with a standard curve agreed with those obtained by the method of standard additions. Four white, 4 red, and 2 rosé wines were studied. Pb concentrations varied from 15 to 135 ng Pb/mL. Wines fortified with 100 ng Pb/mL had an average recovery of 94%. The average short-term relative standard deviation (RSD) was 2.1%; the average long-term RSD was 7.4%. The estimated detection (3 sigma) and quantitation (10 sigma) limits were 4 and 14 ng Pb/mL, respectively.

  11. Determination of toxic metals in some herbal drugs through atomic absorption spectroscopy.

    PubMed

    Hina, Bushra; Rizwani, Ghazala Hafeez; Naseem, Shahid

    2011-07-01

    This study presents a picture of occurrence of heavy metals (Pb, Cd, Cu, Cr, Co, Fe, Ni, Zn) in some selected valuable herbal drugs (G. glabra, O. bracteatum, V. odorata , F. vulgare, C. cyminum, C. sativum, and Z. officinalis) purchased from three different zones (southern, eastern, and western) of Karachi city using atomic absorption spectrophotometer. Heavy metal concentrations in these drugs were found in the range of: 3.26-30.46 for Pb, 1.6-4.91 for Cd, 0.65-120.21 for Cu, 83.74-433.76 for Zn, 1.61-186.75 for Cr, 0.48-76.97 for Ni, 5.54-77.97 for Co and 65.68-1652.89 µg/g for Fe. Percentage of heavy metals that were found beyond the permissible limits were: 71.4% for Pb, 28.51% for Cd, 14.2% for Cu, and 9.5 % for Cr. Significant difference was noticed for each heavy metal among herbal drugs as well as their zones of collection using two way ANOVA followed by least significant (LSD) test at p<0.05.Purpose of this research is to detect each type of heavy metal contaminant of herbal drugs by environmental pollution, as well as to highlight the health risks associated with the use of such herbal drugs that contain high levels of toxic heavy metals.

  12. [Detecting Thallium in Water Samples using Dispersive Liquid Phase Microextraction-Graphite Furnace Atomic Absorption Spectroscopy].

    PubMed

    Zhu, Jing; Li, Yan; Zheng, Bo; Tang, Wei; Chen, Xiao; Zou, Xiao-li

    2015-11-01

    To develope a method of solvent demulsification dispersive liquid phase microextraction (SD-DLPME) based on ion association reaction coupled with graphite furnace atomic absorption spectroscopy (GFAAS) for detecting thallium in water samples. Methods Thallium ion in water samples was oxidized to Tl(III) with bromine water, which reacted with Cl- to form TlCl4-. The ionic associated compound with trioctylamine was obtained and extracted. DLPME was completed with ethanol as dispersive solvent. The separation of aqueous and organic phase was achieved by injecting into demulsification solvent without centrifugation. The extractant was collected and injected into GFAAS for analysis. With palladium colloid as matrix modifier, a two step drying and ashing temperature programming process was applied for high precision and sensitivity. The linear range was 0.05-2.0 microg/L, with a detection limit of 0.011 microg/L. The relative standard derivation (RSD) for detecting Tl in spiked water sample was 9.9%. The spiked recoveries of water samples ranged from 94.0% to 103.0%. The method is simple, sensitive and suitable for batch analysis of Tl in water samples.

  13. Analysis of long-range bullet entrance holes by atomic absorption spectrophotometry and scanning electron microscopy.

    PubMed

    Ravreby, M

    1982-01-01

    Bullet residue and primer particles were analyzed by scanning electron microscopy with energy dispersive analysis (SEM-EDA) and by flame and flameless atomic absorption spectrophotometry (AAS). The residue and particles were on cloth targets around entrance holes produced by bullets fired at distances of 10 to 200 m. Primer particles and their chemical constituents were almost always detected by SEM-EDA around the holes produced by rifles and pistols fired at long ranges, and in many cases the barium and antimony associated with primer particles were detected by flameless AAS. Particles were also detected by SEM-EDA on the rear of bullets fired into and recovered from wooden blocks. Usually a hole caused by a bullet jacketed with gilding metal could be distinguished from one caused by a bullet jacketed with yellow brass alloy. Paint from bullet tips of military tracers was also detected. Analysis of the various residues around entrance holes provides a means for identifying the type of ammunition used.

  14. Stability of low concentration calibration standards for graphite furnace atomic absorption spectrophotometry

    SciTech Connect

    Bass, D A; TenKate, L B

    1993-11-01

    Graphite furnace atomic absorption spectrophotometry (GFAAS) is used for determination of ultra-trace metals in environmentally important samples. In the generation of GFAAS calibration curves for many environmental applications, low concentration calibration standards must be prepared dally, as required by the Statement of Work (SOW) for the US Environmental Protection Agency (EPA) Contract Laboratory Program (CLP). This results in significant time and work for the analyst and significant cost to the Analytical Chemistry Laboratory (ACL) for chemicals and waste management. While EPA SW 846 is less prescriptive than the CLP SOW, ACL has been following the CLP guidelines because in-house criteria regarding the stability of GFAAS standards have not been established. A study was conducted to determine the stability of GFAAS standards for analytes commonly used in the ACL (single and mixed) as a function of time. Data were collected over nine months. The results show that GFAAS standards for Sb, Pb, Se, Ag, and TI are stable for a longer period of time than currently assumed by the CLP SOW. Reducing the frequency of preparing these standards will increase efficiency, decrease the handling of hazardous the quantity of hazardous waste generated, and decrease the quantity of hazardous substances to be ordered and stocked by the laboratory. These benefits will improve GFAAS analysis quality, reduce costs, enhance safety, and lower environmental concerns.

  15. Effects of Solution Physical Properties on Copper and Chromium Signals in Flame Atomic Absorption Spectrometry

    NASA Astrophysics Data System (ADS)

    Rocha, Fàbio R. P.; Nòbrega, Joaquim A.

    1996-10-01

    Instrumental techniques, such as flame atomic absorption spectrometry (FAAS), are frequently used in chemical analysis. Independently of the technique used, the chemical principles must be considered to assure that the analytical results are correct. In FAAS, the most critical step is the sample introduction, since solutions need to be converted in an aerosol (nebulization process) that should contain drops with suitable size to attain the flame. Solution physical properties, such as viscosity and surface tension, can severely affect the analytical signals. Solutions with high viscosity are less easily aspirated and the analyte mass that reach the flame is reduced. The surface tension of the solution affects the size of the drops generated by the nebulization process and can modify the quantity of analyte that attain the flame. This work describes an experiment that allow demonstrating the effects of viscosity and surface tension on analytical signals, using a set of copper solutions prepared in different concentrations of ethanol and chromium solutions prepared in surfactant (tetrapropylammonium bromide) medium. The experiment can be carried out in a 4 h laboratory class and is useful to demonstrate to undergraduate students the effects of samples physical properties on the analytical signals in FAAS.

  16. Stabilizing agents for calibration in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry.

    PubMed

    Zelinková, Hana; Červenka, Rostislav; Komárek, Josef

    2012-01-01

    Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L(-1) TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants.

  17. Determination of arsenic in a nickel alloy by flow injection hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Hanna, C. P.; Tyson, J. F.; Offley, S. G.

    1992-08-01

    The development of a method for the direct determination of trace arsenic quantities in nickel alloy digests, by flow injection hydride generation atomic absorption spectrometry, is described. An optimization study of the manifold and chemical parameters produced system performance, in terms of tolerance of the nickel matrix and sensitivity, such that matrix removal and pre-reduction of As(V) to As (III) prior to arsine generation were eliminated. Full recovery of the As(V) signal from a solution containing 5 ng ml -1 in the presence of 60 μg ml -1 nickel was obtained. Validation of the method was achieved by analyzing a British Chemical Standard (BCS) Certified Reference Material (CRM) #346 IN nickel alloy containing arsenic at a concentration of 50 μg g -1. Following dissolution in nitric and hydrofluoric acids by a microwave assisted procedure, the only subsequent preparation required was dilution by the appropriate factor. Up to 60 injections h -1 may be made, with a detection limit of 0.5 ng ml -1 arsenic (250 pg absolute) as As(V) in a 500 μl sample. The peak height characteristic concentration is 0.46 ng ml -1, with a relative standard deviation of 3.5% for a 10 ng ml -1 As(V) standard ( n = 6).

  18. Determination of nickel in active pharmaceutical ingredients by electrothermal atomic absorption spectrometry.

    PubMed

    Bubnič, Zoran; Urleb, Uroš; Kreft, Katjuša; Veber, Marjan

    2010-03-01

    An electrothermal atomic absorption spectrometric procedure for the determination of nickel in active pharmaceutical ingredients was developed. Since the recoveries of nickel by the direct dissolution of samples in diluted nitric acid were low and caused errors in the determination of Ni in pharmaceutical samples, different approaches for sample pre-treatment were examined. It was found that the microwave digestion was the most suitable way for sample preparation. Various combinations of digestion agents and different microwave conditions were tested. The combination of nitric acid and hydrogen peroxide was found to be the most appropriate. The validity of the method was evaluated by recovery studies of spiked samples and by the comparison of the results obtained by inductively coupled plasma mass spectrometry (ICP-MS). The recovery ranged from 87.5 to 104.0% and a good agreement was achieved between both methods. The detection limit and the limit of quantification were 0.6 and 2.1 µg g-1 respectively. The precision of the method was confirmed by the determination of Ni in the spiked samples and was below 4%, expressed in terms of a relative standard deviation. The method was applied to the determination of nickel in production samples of active pharmaceutical ingredients and intermediates.

  19. Assessment of toxic metals in raw and processed milk samples using electrothermal atomic absorption spectrophotometer.

    PubMed

    Kazi, Tasneem Gul; Jalbani, Nusrat; Baig, Jameel Ahmed; Kandhro, Ghulam Abbas; Afridi, Hassan Imran; Arain, Mohammad Balal; Jamali, Mohammad Khan; Shah, Abdul Qadir

    2009-09-01

    Milk and dairy products have been recognized all over the world for their beneficial influence on human health. The levels of toxic metals (TMs) are an important component of safety and quality of milk. A simple and efficient microwave assisted extraction (MAE) method has been developed for the determination of TMs (Al, Cd, Ni and Pb), in raw and processed milk samples. A Plackett-Burman experimental design and 2(3)+star central composite design, were applied in order to determine the optimum conditions for MAE. Concentrations of TMs were measured by electrothermal atomic absorption spectrometry. The accuracy of the optimized procedure was evaluated by standard addition method and conventional wet acid digestion method (CDM), for comparative purpose. No significant differences were observed (P>0.05), when comparing the values obtained by the proposed MAE method and CDM (paired t-test). The average relative standard deviation of the MAE method varied between 4.3% and 7.6% based on analyte (n=6). The proposed method was successfully applied for the determination of understudy TMs in milk samples. The results of raw and processed milk indicated that environmental conditions and manufacturing processes play a key role in the distribution of toxic metals in raw and processed milk.

  20. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry.

    PubMed

    Rey-Raap, Natalia; Gallardo, Antonio

    2012-05-01

    In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52±0.4ppb of mercury in the vapor phase, 204.16±8.9ppb of mercury in the phosphor powder, and 18.74±0.5ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  1. Cadmium accumulation in the crayfish, Procambarus clarkii, using graphite furnace atomic absorption spectroscopy

    SciTech Connect

    Diaz-Mayans, J.; Hernandez, F.; Medina, J.; Del Ramo, J.; Torreblanca, A.

    1986-11-01

    Lake Albufera and the surrounding rice-field waters are being subject to very heavy loads of sewage and toxic industrial residues (including heavy metals and pesticides) from the many urban and wastewaters in this area. The American red crayfish Procambarus clarkii is native to the Louisiana marshes (USA). In 1978, the crayfish appeared in Lake Albufera near Valencia (Spain), and presently, without adequate sanitary controls, the crayfish is being fished commercially for human consumption. In view of this interest, it is important to have accurate information on concentrations of cadmium in natural waters and cadmium levels of tissues of freshwaters animals used as human food, as well as the accumulation rates of this metal in this animal. In the present study, the authors investigated the accumulation of cadmium in several tissues of the red crayfish, P clarkii (Girard) from Lake Albufera following cadmium exposure. Determinations of cadmium were made by flameless atomic absorption spectroscopy and the standard additions method. Digestion of samples was made by wet ashing in open flasks with concentrated HNO/sub 3/ at 80-90/sup 0/C.

  2. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

    NASA Astrophysics Data System (ADS)

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.; Leone, Stephen R.

    2016-01-01

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicate the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. An intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.

  3. An X-ray photoelectron spectroscopy study of the atomization of Mo from pyrolytic graphite platforms in Electrothermal Atomic Absorption Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ruiz, Frine; Benzo, Zully; Garaboto, Angel; León, Vladimir; Ruette, Fernando; Albornoz, Alberto; Brito, Joaquín L.

    2017-07-01

    X-ray photoelectron spectroscopy (XPS) was employed as the analytical tool for the identification of the solid state species formed during the atomization of molybdenum on a pyrolytic graphite surface used for electrothermal atomization in atomic absorption spectroscopy (ETAAS). As XPS is capable of probing the amounts of materials employed in actual ETAAS measurements, it was anticipated that it would allow obtaining more realistic results than those reported in previous works by means of techniques such as X-ray diffraction, which requires thousand-fold amounts of the analyte. The results obtained by XPS showed a distribution pattern of the oxidation states of Mo on the graphite surface as a function of the temperatures reached at each stage of the ETAAS procedure, which was correlated with the possible species formed during the drying, ashing and atomization steps. In light of the present results, a previously proposed atomization mechanism for Mo was revisited, which allowed to disprove the alleged presence of phases such as Mo4O11 at the ashing stage and of metallic Mo as a stable, intermediate phase during the Mo2C low temperature carbide formation at 1200-1900 °C. It is concluded that the XPS technique allows gaining an insight into the atomization mechanism of the analyte.

  4. Absolute number densities of helium metastable atoms determined by atomic absorption spectroscopy in helium plasma-based discharges used as ambient desorption/ionization sources for mass spectrometry

    NASA Astrophysics Data System (ADS)

    Reininger, Charlotte; Woodfield, Kellie; Keelor, Joel D.; Kaylor, Adam; Fernández, Facundo M.; Farnsworth, Paul B.

    2014-10-01

    The absolute number densities of helium atoms in the 2s 3S1 metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 1012 cm- 3 and 0.011 × 1012 cm- 3, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 1012 cm- 3 and 0.97 × 1012 cm- 3 were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges.

  5. Temperature-controlled electrothermal atomization-atomic absorption spectrometry using a pyrometric feedback system in conjunction with a background monitoring device

    NASA Astrophysics Data System (ADS)

    Van Deijck, W.; Roelofsen, A. M.; Pieters, H. J.; Herber, R. F. M.

    The construction of a temperature-controlled feedback system for electrothermal atomization-atomic absorption spectrometry (ETA-AAS) using an optical pyrometer applied to the atomization stage is described. The system was used in conjunction with a fast-response background monitoring device. The heating rate of the furnace amounted to 1400° s -1 with a reproducibility better than 1%. The precision of the temperature control at a steady state temperature of 2000°C was 0.1%. The analytical improvements offered by the present system have been demonstrated by the determination of cadmium and lead in blood and finally by the determination of lead in serum. Both the sensitivity and the precision of the method have been improved. The accuracy of the method was checked by determining the lead content for a number of scrum samples both by ETA-AAS and differential pulse anodic stripping voltametry (DPASV) and proved to be satisfactory.

  6. Determination of cadmium in tobacco smoke by electrothermal atomic absorption spectroscopy with electrostatic precipitation of samples on the graphite tube atomizer

    NASA Astrophysics Data System (ADS)

    Altman, E. L.; Panichev, N. A.

    2003-05-01

    The determination of Cd in ambient air, associated with tobacco smoke, has been carried out by electrostatic precipitation of Cd directly in a graphite tube, which was subsequently used as an atomizer in electrothermal atomization atomic absorption spectroscopy (ET-AAS). It is shown that graphite tube permanently modified with Ir allows carrying out pyrolysis of collected samples at 1000^circC, leading to minimization of the blank. The combination of electrostatic precipitation of Cd from ambient air into the graphite tube with high efficiency of Cd determination by ET-AAS allows to trace Cd in ambient air for 25 min after the smoking a cigarette. The limit of detection (LOD) of Cd determination was found to be 0.2 ng m^{-3} The results of investigations confirm the danger of passive smoking due to the presence of Cd in smoking areas.

  7. Oxygen vacancy mediated enhanced photo-absorption from ZnO(0001) nanostructures fabricated by atom beam sputtering

    SciTech Connect

    Solanki, Vanaraj; Joshi, Shalik R.; Mishra, Indrani; Varma, Shikha; Kabiraj, D.; Avasthi, D. K.; Mishra, N. C.

    2016-08-07

    The nanoscale patterns created on the ZnO(0001) surfaces during atom beam irradiation have been investigated here for their photo absorption response. Preferential sputtering, during irradiation, promotes Zn-rich zones that serve as the nucleation centers for the spontaneous creation of nanostructures. Nanostructured surfaces with bigger (78 nm) nanodots, displaying hexagonal ordering and long ranged periodic behavior, show higher photo absorption and a ∼0.09 eV reduced bandgap. These nanostructures also demonstrate higher concentration of oxygen vacancies which are crucial for these results. The enhanced photo-response, as observed here, has been achieved in the absence of any dopant elements.

  8. Modifiers and coatings in graphite furnace atomic absorption spectrometry—mechanisms of action (A tutorial review)

    NASA Astrophysics Data System (ADS)

    Ortner, H. M.; Bulska, E.; Rohr, U.; Schlemmer, G.; Weinbruch, S.; Welz, B.

    2002-12-01

    furnace atomic absorption spectrometry (GFAAS): sample application and drying; pyrolysis; atomization. Contrary to the vast amount of literature on this topic it tried to provide the analyst working with GFAAS and in an increasing number working with Solid Sampling-GFAAS with a set of most important statements. This might spare the experimentalist a lot of useless optimization procedures but should lead him to a basic understanding of the complex phenomena taking place in his instrument and during his analytical work.

  9. Hydride generation in-atomizer collection atomic absorption spectrometry for the determination of antimony in acetic acid leachates from pewter cups.

    PubMed

    Dessuy, Morgana B; Kratzer, Jan; Vale, Maria Goreti R; Welz, Bernhard; Dědina, Jiří

    2011-12-15

    Antimony is one of the constituents of pewter, an alloy composed of a minimum of 90% tin with the balance being made up with copper, antimony and perhaps some bismuth. A method has been developed to determine Sb in acetic acid leachates from pewter cups. The employed instrumentation, an atomic absorption spectrometer, equipped with a quartz trap-and-atomizer device, is simple and relatively inexpensive with low running costs. Interferences due to the presence of tin and ways to control them were investigated in detail. The applied approach made possible to overcome potentially serious interference of Sn leached from the cup material (which was shown to take place in the atomizer), by a combination of (i) high concentration of HCl, which decreases the efficiency of stannane generation and (ii) in-atomizer collection. The resulting Sn tolerance limit was between 10 and 20 mg L(-1). The advantages of the in-atomizer collection are a lower tin interference in the atomizer, and a much better limit of detection (LOD), which makes possible reducing the atomization interference further by working with more diluted sample solutions. Besides the Sn interference, an interference of an unknown volatile compound transported to the atomizer together with stibine was identified in the measured sample solutions. This interference could be controlled using the analyte addition technique. The applicability of the method was tested on solutions containing a wide range of interferents leached from the pewter cups, obtained at leaching times between 1 and 24h. The LOD in the sample solutions was found to be 0.03 μg L(-1) Sb. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure

    PubMed Central

    Korecki, P.; Tolkiehn, M.; Dąbrowski, K. M.; Novikov, D. V.

    2011-01-01

    Projections of the atomic structure around Nb atoms in a LiNbO3 single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10 Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples. PMID:21997909

  11. Determination of mercury in phosphate fertilizers by cold vapor atomic absorption spectrometry.

    PubMed

    de Jesus, Robson M; Silva, Laiana O B; Castro, Jacira T; de Azevedo Neto, Andre D; de Jesus, Raildo M; Ferreira, Sergio L C

    2013-03-15

    In this paper, a method for the determination of mercury in phosphate fertilizers using slurry sampling and cold vapor atomic absorption spectrometry (CV QT AAS) is proposed. Because mercury (II) ions form strong complexes with phosphor compounds, the formation of metallic mercury vapor requires the presence of lanthanum chloride as a release agent. Thiourea increases the amount of mercury that is extracted from the solid sample to the liquid phase of the slurry. The method is established using two steps. First, the slurry is prepared using the sample, lanthanum chloride, hydrochloric acid solution and thiourea solution and is sonicated for 20 min. Afterward, mercury vapor is generated using an aliquot of the slurry in the presence of the hydrochloric acid solution and isoamylic alcohol with sodium tetrahydroborate solution as the reducing agent. The experimental conditions for slurry preparation were optimized using two-level full factorial design involving the factors: thiourea and lanthanum chloride concentrations and the duration of sonication. The method allows the determination of mercury by external calibration using aqueous standards with limits of detection and quantification of 2.4 and 8.2 μg kg(-1), respectively, and precision, expressed as relative standard deviation, of 6.36 and 5.81% for two phosphate fertilizer samples with mercury concentrations of 0.24 and 0.57 mg kg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of phosphate fertilizer that was provided by the National Institute of Standards & Technology (NIST). The method was applied to determine mercury in six commercial samples of phosphate fertilizers. The mercury content varied from 33.97 to 209.28 μg kg(-1). These samples were also analyzed employing inductively coupled plasma mass spectrometry (ICP-MS). The ICP-MS results were consistent with the results from our proposed method.

  12. Cadmium and lead in infant cereals--electrothermal-atomic absorption spectroscopic determination.

    PubMed

    Roca de Togores, M; Farré, R; Frigola, A M

    1999-08-30

    Because infant cereals are an important component of the infant diet from the fourth month of life onwards and therefore contribute to the dietetic intake of metals by infants, cadmium and lead were measured in samples of cereals commercially available in Spain. For this purpose an electrothermal atomic absorption (ET-AAS) method for determining cadmium and lead in these products was studied. The ET-AAS instrumental conditions and temperature/time furnace program were selected. The analytical parameters of the method (linearity, detection and quantification limits and precision) show its usefulness in measuring cadmium and lead in infant cereal products. The method was applied to eight different types of infant cereals from four different manufacturers, in all 29 different infant cereal products commercially available in Spain. The cadmium and lead contents of milk-free infant cereals range from 6.6 to 35.8 ng/g and from 36.1 to 305.6 ng/g, respectively, while the ranges corresponding to milk-added infant cereals are 2.9-40.0 ng/g for cadmium and 53.5-598.3 ng/g for lead. The cadmium and lead contents of cereal products of the same type from different manufacturers is responsible for the large confidence intervals and made it impossible to detect significant differences among the different products. Given the values found for lead and the correlation between chronic exposure to low lead doses and neuropsychological damage in early childhood, efforts should be made to reduce lead contamination.

  13. Atomic Absorption Spectrometry in Wilson's Disease and Its Comparison with Other Laboratory Tests and Paraclinical Findings

    PubMed Central

    Mahjoub, Fatemeh; Fereiduni, Rana; Jahanzad, Isa; Farahmand, Fatemeh; Monajemzadeh, Maryam; Najafi, Mehri

    2012-01-01

    Objective Wilson's disease (WD) is an autosomal recessive disease with genetic abnormality on chromosome 13 causing defect in copper metabolism and increased copper concentration in liver, central nervous system and other organs, which causes different clinical manifestations. The aim of this study was to determine the sensitivity of different clinical and paraclinical tests for diagnosis of Wilson's disease. Methods Paraffin blocks of liver biopsy from 41 children suspicious of WD were collected. Hepatic copper concentrations were examined with atomic absorption spectrophotometry (Australian GBC, model: PAL 3000). Fifteen specimens had hepatic copper concentration (dry weight) more than 250μg/g. Clinical and laboratory data and histologic slides of liver biopsies of these 15 children were reviewed retrospectively. Liver tissue was examined for staging and grading of hepatic involvement and also stained with rubeonic acid method for copper. Findings Patients were 5-15 years old (mean age=9.3 years, standard deviation=2.6) with slight male predominance (9/15=60%). Five (33%) patients were 10 years old. Three (20%) of them were referred for icterus, 8 (54%) because of positive family history, 2 (13%) due to abdominal pain and 2 (13%) because of hepatosplenomegaly and ascites. Serum AST and ALT levels were elevated at the time of presentation in all patients. In liver biopsy, histological grade and stage was 0-8 and 0-6 respectively, 2 (13%) had cirrhosis, 1 (7%) had normal biopsy and 12 (80%) showed chronic hepatitis. Hepatic copper concentrations were between 250 and 1595 μg/g dry weight. The sensitivity of various tests were 85% for serum copper, 83% for serum ceruloplasmin, 53% for urinary copper excretion, 44% for presence of KF ring and 40% for rubeonic acid staining on liver biopsies. Conclusion None of the tests stated in the article were highly sensitive for diagnosis of WD, so we suggest that diagnosis should be based on combination of family history

  14. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry

    SciTech Connect

    Rey-Raap, Natalia

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer New treatments for CFL are required considering the aim of Directive 202/96/CE. Black-Right-Pointing-Pointer It is shown that most of the mercury introduced into a CFL is in the phosphor powder. Black-Right-Pointing-Pointer Experimental conditions for microwave-assisted sample digestion followed by AAS measurements are described. Black-Right-Pointing-Pointer By washing the glass it is possible to reduce the concentration below legal limits. - Abstract: In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52 {+-} 0.4 ppb of mercury in the vapor phase, 204.16 {+-} 8.9 ppb of mercury in the phosphor powder, and 18.74 {+-} 0.5 ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste.

  15. Simple analysis of total mercury and methylmercury in seafood using heating vaporization atomic absorption spectrometry.

    PubMed

    Yoshimoto, Keisuke; Anh, Hoang Thi Van; Yamamoto, Atsushi; Koriyama, Chihaya; Ishibashi, Yasuhiro; Tabata, Masaaki; Nakano, Atsuhiro; Yamamoto, Megumi

    2016-01-01

    This study aimed to develop a simpler method for determining total mercury (T-Hg) and methylmercury (MeHg) in biological samples by using methyl isobutyl ketone (MIBK) in the degreasing step. The fat in the samples was extracted by MIBK to the upper phase. T-Hg transferred into the water phase. This was followed by the extraction of MeHg from the water phase using HBr, CuCl2 and toluene. The MeHg fraction was reverse-extracted into L-cysteine-sodium acetate solution from toluene. The concentrations of T-Hg and MeHg were determined by heating vaporization atomic absorption spectrometry. Certified reference materials for T-Hg and MeHg in hair and fish were accurately measured using this method. This method was then applied to determine T-Hg and MeHg concentrations in the muscle, liver and gonads of seafood for the risk assessment of MeHg exposure. The mean T-Hg and MeHg concentrations in squid eggs were 0.023 and 0.022 µg/g, and in squid nidamental glands 0.052 and 0.049 µg/g, respectively. The MeHg/T-Hg ratios in the eggs and nidamental glands of squid were 94.4% and 96.5%, respectively. The mean T-Hg and MeHg concentrations in the gonads of sea urchins were 0.043 and 0.001 µg/g, respectively, with a MeHg/T-Hg ratio of 3.5%. We developed an efficient analytical method for T-Hg and MeHg using MIBK in the degreasing step. The new information on MeHg concentration and MeHg/T-Hg ratios in the egg or nidamental glands of squid and gonads of sea urchin will also be useful for risk assessment of mercury in seafood.

  16. [Determination of metals in Ginkgo biloba leaves by atomic absorption spectrometry with microwave digestion].

    PubMed

    Jiang, Bo; Jiang, Guo-Bin; Liu, Chang-Jian; Ma, Kun; Jin, Li-Ming; Gao, Jiang-Mei

    2010-03-01

    Microwave digestion technique was used in the decomposition of Ginkgo biloba leaves from six different trees at the same age in the same area. HNO3-H2O2 (5 : 1 v/v) was used as microwave digestion agent at a suitable temperature and time. The contents of Ca, Mg, K, Na, Cu, Zn and Zn/Cu were determined by flame atomic absorption spectrometry to study the distribution rule of metallic elements in the trees at the same age and in the same area. The recovery ratio ranged from 95.2% to 104.6%. The results showed that there were certain differences between different trees in the distribution of metallic elements. The contents of calcium were from 39 586 to 48 320 microg x g(-1), and those of magnesium from 10 076 to 12 918 microg x g(-1), of potassium from 2 004 to 5 240 microg x g(-1), of sodium from 9.05 to 35.30 microg x g(-1), and of copper from 1.50 to 3.05 microg x g(-1), while Zn/Cu values were from 2.68 to 5.93 in the leaves of 6 different trees in the same growing area. Therefore there were abounding calcium, magnesium and potassium, while the content of sodium and Zn/Cu values were lower, and the metal contents were different in the leaves. The experimental results provided useful bases for studying the distribution rule of metallic elements in Ginkgo biloba leaves, the relationship between the contents of calcium, magnesium, potassium and sodium and the Zn/Cu value in ginkgo biloba leaves and the treatment for cardio-cerebral vascular disease.

  17. On-line preconcentration and speciation of arsenic by flow injection hydride generation atomic absorption spectrophotometry.

    PubMed

    Narcise, Cristine Ingrid S; Coo, Lilibeth Dlc; Del Mundo, Florian R

    2005-12-15

    A flow injection-column preconcentration-hydride generation atomic absorption spectrophotometric (FI-column-HGAAS) method was developed for determining mug/l levels of As(III) and As(V) in water samples, with simultaneous preconcentration and speciation. The speciation scheme involved determining As(V) at neutral pH and As(III+V) at pH 12, with As(III) obtained by difference. The enrichment factor (EF) increased with increase in sample loading volume from 2.5 to 10ml, and for preconcentration using the chloride-form anion exchange column, EFs ranged from 5 to 48 for As(V) and 4 to 24 for As(III+V), with corresponding detection limits of 0.03-0.3 and 0.07-0.3mug/l. Linear concentration range (LCR) also varied with sample loading volume, and for a 5-ml sample was 0.3-5 and 0.2-8mug/l for As(V) and As(III+V), respectively. Sample throughput, which decreased with increase in sample volume, was 8-17 samples/h. For the hydroxide-form column, the EFS for 2.5-10ml samples were 3-23 for As(V) and 2-15 for As(III+V), with corresponding detection limits of 0.07-0.4 and 0.1-0.5mug/l. The LCR for a 5-ml sample was 0.3-10mug/l for As(V) and 0.2-20mug/l for As(III+V). Sample throughput was 10-20 samples/h. The developed method has been effectively applied to tap water and mineral water samples, with recoveries ranging from 90 to 102% for 5-ml samples passed through the two columns.

  18. Direct analysis of reference biofluids by coupled in situ electrodeposition-electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Matousek, Jaroslav P.; Powell, Kipton J.

    1999-12-01

    The application of coupled in situ electrodeposition-electrothermal atomic absorption spectrometry (ED-ETAAS) to the determination of Pb in biological standard reference materials is described. In situ electrodeposition at a cell voltage of 3.0 V from 25-μl samples onto electrodeposited Pd is used to quantitatively separate the analyte from blood and urine matrices. With subsequent withdrawal of spent electrolyte, this overcomes the atomisation problems inherent with high salt and organic contents. ED-ETAAS is applied with minimal sample pre-treatment (acidification). The electrolysis process aids decomposition of the organic matrix, and the release of trace elements. Evolution of H 2 at the cathode counters fouling of the Pd modifier surface. The palladium deposit is renewed in situ for each determination. For AMI certified lyophilised blood, diluted 1+3 with 0.1 M HCl (18.1 μg/l Pb), the R.S.D. was 3.0% (peak height; n=5) and the detection limit (3 σ blank; n=5) was 1.5 μg/l. Results for certified blood samples were AMI 72.3±4.3 μg/l (certified 76.2±7.6 μg/l) and Seronorm 34.2±2.0 μg/l (36±4 μg/l). The result for NIST SRM 2670 normal urine acidified to 1% HNO 3 was 8.1±0.6 μg/l (recommended value 10 μg/l).

  19. Separation and quantitation of metallothioneins by high-performance liquid chromatography coupled with atomic absorption spectrophotometry

    SciTech Connect

    Lehman, L.D.; Klaassen, C.D.

    1986-03-01

    A rapid, reproducible, and sensitive high-performance liquid chromatography (HPLC) method for the determination of the concentrations of metallothionein-I (MT-I) and metallothionein-II (MT-II) in rat liver has been developed. Metallothioneins (MTs) were separated and quantitated by anion-exchange high-performance liquid chromatography coupled with atomic absorption spectrophotometry (AAS). Purified rat liver MT-I and MT-II, used as standards for developing the method, were easily resolved, eluting at 7.5 and 10.4 min, respectively. To establish standard curves, protein concentrations of solutions of the purified MTs were determined by the Kjeldahl method for the determination of nitrogen, after which the standards were saturated with Cd (final concentration of 50 ppm Cd). Rat liver cytosols obtained from untreated and Cd- or Zn-treated rats were prepared for HPLC-AAS analysis by saturation with Cd (50 ppm Cd) followed by heat denaturation (placing in a boiling water bath for 1 min). Based on the method of standard additions, recovery of MTs exceeded 95% and repeated injection of a sample yielded a coefficient of variance of approximately 2%. A detection limit of 5 ..mu..g MT/g liver was established for the method. Only MT-II was detected in untreated rats, whereas following exposure to Cd or Zn, both forms of MTs were detected. Concentrations of total MTs in liver of untreated and Cd- or Zn-treated rats were also determined by the Cd/hemoglobin radioassay (which fails to distinguish MT-I from MT-II) and indicated that results obtained with the HPLC-AAS method compared favorably to the Cd/hemoglobin radioassay.

  20. Aluminum determined in plasma and urine by atomic absorption spectroscopy with a transversely heated graphite atomizer furnace.

    PubMed

    Bradley, C; Leung, F Y

    1994-03-01

    We compared a stabilized-temperature L'vov platform furnace containing an end-heated graphite atomizer (HGA) and transverse Zeeman background-correction system with a side-heated furnace system (transversely heated graphite atomizer; THGA) containing a longitudinal Zeeman background-correction system for the determination of aluminum in plasma and urine. The regression statistics for the correlation analysis of the two systems (slope coefficient = 0.995, intercept = -1.710, Sy/x = 0.021 micrograms/L) indicate that the systems generate comparable results. The newer technology of the THGA furnace with its more uniform and faster heating cycle allows a lower atomization temperature for aluminum, 2200 degrees C. Analyte carryover was significantly reduced in the THGA furnace system. The THGA system generates results equivalent to HGA in about one-third less time, thus making possible a greater throughput of samples in a busy laboratory.

  1. Sample pre-treatment methods for the trace elements determination in seafood products by atomic absorption spectrometry.

    PubMed

    Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Adela

    2002-07-03

    Different sample pre-treatments for seafood products have been compared with determine trace elements (As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Se and Zn) by flame atomic absorption spectrometry (FAAS) and electrothermal atomic absorption spectrometry (ETAAS). Classic pre-treatments as microwave assisted-acid digestion and the slurry sampling technique were compared with new procedures such as microwave energy or ultrasound energy assisted-acid leaching process and enzymatic hydrolysis methodologies based on the use of pronase E. The methods were applied to DORM-1 and DOLT-1 reference materials with certified contents for the studied elements. The Student-Newman-Keuls (SNK) method was used to compare with element concentration means obtained with each sample pre-treatment and also the certified concentration means in both reference materials. Multivariate techniques such as principal components analysis (PCA) was also applied to comparative purposes.

  2. Metastable argon atom density in complex argon/acetylene plasmas determined by means of optical absorption and emission spectroscopy

    NASA Astrophysics Data System (ADS)

    Sushkov, Vladimir; Herrendorf, Ann-Pierra; Hippler, Rainer

    2016-10-01

    Optical emission and absorption spectroscopy has been utilized to investigate the instability of acetylene-containing dusty plasmas induced by growing nano-particles. The density of Ar(1s5) metastable atoms was derived by two methods: tunable diode laser absorption spectroscopy and with the help of the branching ratio method of emitted spectral lines. Results of the two techniques agree well with each other. The density of Ar(1s3) metastable atoms was also measured by means of optical emission spectroscopy. The observed growth instability leads to pronounced temporal variations of the metastable and other excited state densities. An analysis of optical line ratios provides evidence for a depletion of free electrons during the growth cycle but no indication for electron temperature variations.

  3. Matrix effects on the determination of manganese in geological materials by atomic-absorption spectrophotometry under different flame conditions

    USGS Publications Warehouse

    Sanzolone, R.F.; Chao, T.T.

    1978-01-01

    Suppression caused by five of the seven matrix elements studied (Si, Al, Fe, Ca and Mg) was observed in the atomic-absorption determination of manganese in geological materials, when synthetic solutions and the recommended oxidizing air-acetylene flame were used. The magnitude of the suppression effects depends on (1) the kind and concentration of the interfering elements, (2) the type of acid medium, and (3) the concentration of manganese to be determined. All interferences noted are removed or alleviated by using a reducing nitrous oxide-acetylene flame. The atomic-absorption method using this flame can be applied to the determination of total and extractable manganese in a wide range of geological materials without interferences. Analyses of six U.S. Geological Survey rock standards for manganese gave results in agreement with the reported values. ?? 1978.

  4. Efficiency of generation of highly ionised atoms under resonance absorption of CO{sub 2}-laser radiation

    SciTech Connect

    Gus'kov, Sergei Yu; Demchenko, N N; Makarov, K N; Rozanov, Vladislav B; Satov, Yu A; Sharkov, Boris Yu

    2011-10-31

    We consider the generation of beams of highly ionised atoms in solid targets irradiated with CO{sub 2}-laser pulses. We present experimental results on generation of Mg and Pb ions from laser plasma at a radiation flux density q Almost-Equal-To 10{sup 14} W cm{sup -2}. We have developed a theoretical model describing the plasma heating by CO{sub 2}-laser radiation at a high pulse intensity on the target, taking into account the ponderomotive forces affecting the behaviour of the interaction of light with the plasma. It is shown that in the case of resonance absorption of laser radiation by the plasma, the efficiency of generation of highly ionised atoms of the target substance is higher than the efficiency of generation in the case of classical absorption. The results of the numerical calculation by the developed model are in good agreement with the experiment.

  5. Method development for the determination of lead in wine using electrothermal atomic absorption spectrometry comparing platform and filter furnace atomizers and different chemical modifiers.

    PubMed

    Dessuy, Morgana B; Vale, Maria Goreti R; Souza, Anderson S; Ferreira, Sérgio L C; Welz, Bernhard; Katskov, Dmitri A

    2008-02-15

    A method has been developed for the determination of lead in wine by electrothermal atomic absorption spectrometry without any sample preparation and calibration against aqueous standards, using 7.5 microg Pd as a chemical modifier. The results obtained for seven wines using the proposed method and an acid digestion procedure did not show any significant difference using a Student's t-test. Atomization in a transversally heated filter atomizer (THFA) was compared with atomization in a conventional transversally heated platform furnace. The former provided a 2.6-fold higher sensitivity, improving the characteristic mass from 34 to 12 pg and a 1.6-fold better limit of detection (0.3 microg L(-1) compared to 0.5 microg L(-1)) for aqueous solutions using the same injection volume of 20 microL. However, the average precision, expressed as the relative standard deviation for the determination of lead in wine under routine conditions was improved from 4.6% with platform atomization to 0.6% in the THFA. The lead content found in seven arbitrarily chosen white and red wines, five from Brazil, one from Chile and one from Spain, ranged from 6 to 60 microg L(-1) Pb with an average content of 11.4 microg L(-1) Pb for the wines from South America.

  6. Arsenic in marine tissues — The challenging problems to electrothermal and hydride generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Karadjova, Irina B.; Petrov, Panayot K.; Serafimovski, Ivan; Stafilov, Trajče; Tsalev, Dimiter L.

    2007-03-01

    Analytical problems in determination of arsenic in marine tissues are addressed. Procedures for the determination of total As in solubilized or extracted tissues with tetramethylammonium hydroxide and methanol have been elaborated. Several typical lyophilized tissues were used: NIST SRM 1566a 'Oyster Tissue', BCR-60 CRM 'Trace Elements in an Aquatic Plant ( Lagarosiphon major)', BCR-627 'Forms of As in Tuna Fish Tissue', IAEA-140/TM 'Sea Plant Homogenate', NRCC DOLT-1 'Dogfish Liver' and two representatives of the Black Sea biota, Mediterranean mussel ( Mytilus galloprovincialis) and Brown algae ( Cystoseira barbata). Tissues (nominal 0.3 g) were extracted in tetramethylammonium hydroxide (TMAH) 1 ml of 25% m/v TMAH and 2 ml of water) or 5 ml of aqueous 80% v/v methanol (MeOH) in closed vessels in a microwave oven at 50 °C for 30 min. Arsenic in solubilized or extracted tissues was determined by electrothermal atomic absorption spectrometry (ETAAS) after appropriate dilution (nominally to 25 ml, with further dilution as required) under optimal instrumental parameters (pyrolysis temperature 900 °C and atomization temperature 2100 °C) with 1.5 μg Pd as modifier on Zr-Ir treated platform. Platforms have been pre-treated with 2.7 μmol of zirconium and then with 0.10 μmol of iridium which served as a permanent chemical modifier in direct ETAAS measurements and as an efficient hydride sequestration medium in flow injection hydride generation (FI-HG)-ETAAS. TMAH and methanol extract 96-108% and 51-100% of As from CRMs. Various calibration approaches have been considered and critically evaluated. The effect of species-dependent slope of calibration graph or standard additions plot for total As determination in a sample comprising of several individual As species with different ETAAS behavior has been considered as a kind of 'intrinsic element speciation interference' that cannot be completely overcome by standard additions technique. Calibration by means of CRMs has

  7. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Sardans, Jordi; Montes, Fernando; Peñuelas, Josep

    2010-02-01

    Pollution from heavy metals has increased in recent decades and has become an important concern for environmental agencies. Arsenic, cadmium, copper, mercury and lead are among the trace elements that have the greatest impact and carry the highest risk to human health. Electrothermal atomic absorption spectrometry (ETAAS) has long been used for trace element analyses and over the past few years, the main constraints of atomic absorption spectrometry (AAS) methods, namely matrix interferences that provoked high background absorption and interferences, have been reduced. The use of new, more efficient modifiers and in situ trapping methods for stabilization and pre-concentration of these analytes, progress in control of atomization temperatures, new designs of atomizers and advances in methods to correct background spectral interferences have permitted an improvement in sensitivity, an increase in detection power, reduction in sample manipulation, and increase in the reproducibility of the results. These advances have enhanced the utility of Electrothermal atomic absorption spectrometry (ETAAS) for trace element determination at μg L -1 levels, especially in difficult matrices, giving rise to greater reproducibility, lower economic cost and ease of sample pre-treatment compared to other methods. Moreover, the recent introduction of high resolution continuum source Electrothermal atomic absorption spectrometry (HR-CS-ETAAS) has facilitated direct solid sampling, reducing background noise and opening the possibility of achieving even more rapid quantitation of some elements. The incorporation of flow injection analysis (FIA) systems for automation of sample pre-treatment, as well as chemical vapor generation renders (ETAAS) into a feasible option for detection of As and Hg in environmental and food control studies wherein large numbers of samples can be rapidly analyzed. A relatively inexpensive approach with low sample consumption provide additional advantages of

  8. Robotized sampling device for graphite furnace atomic absorption spectrometry slurry analysis with Varian SpectrAA instruments

    NASA Astrophysics Data System (ADS)

    Hoenig, Michel; Cilissen, Anne

    1993-08-01

    There is a growing interest in the determination by electrothermal atomic absorption spectrometry (ETAAS) of elements in solid samples without a dissolution stage, to avoid contamination and losses during the preparation of the sample. This approach may be particularly convenient when only small amounts of sample are available. Details of the above-mentioned program for the adaptation of the Gilson sample changer to Varian SpectrAA systems (X,Y,Z positions, timings etc.) are available on request.

  9. Wear-metal analysis in engine oil by microwave digestion and atomic absorption spectroscopy. Final report, August 1987-January 1988

    SciTech Connect

    Muse, W.T.

    1990-05-01

    Digestion procedures are described for the analysis of wear metals in National Bureau of Standards (NBS) oil samples by a closed vessel microwave digestion system. Samples were analyzed by flame atomic absorption spectroscopy. Recoveries of Al, Fe, Ni, Cu, and Pb in the 300-ppm NBS oil ranged from 98 to 103% with standard deviations from 3 to 14%. This method serves as a relatively quick matrix destruction technique for the quantitation of metals in oil.

  10. Differentiation and classification of beers with flame atomic spectrometry and molecular absorption spectrometry and sample preparation assisted by microwaves

    NASA Astrophysics Data System (ADS)

    Bellido-Milla, Dolores; Moreno-Perez, Juana M.; Hernández-Artiga, María. P.

    2000-07-01

    The characterization of beer samples has a lot of interest because their composition can affect the taste and stability of beer and consumer health. Flame atomic absorption spectrometry was used to determine Fe, Mn, Zn, Cu, Mg, Ca and Al. Sodium and K were determined by flame atomic emission spectrometry. A sample preparation method was developed, based on treatment with HNO 3 and H 2O 2 in a microwave oven. This has many advantages over the methods found in the literature. The combination of the results of atomic spectrometry and the spectrum obtained by molecular absorption spectrometry provides information on the inorganic and organic components of the samples. The application of chemometric techniques to chemical composition data could be extremely useful for food quality control. The metal concentrations, the molecular absorption spectrum, the pH and conductivity of each sample were subject to analysis of variance and linear discriminant analysis. Twenty-five different beer samples were used to differentiate and classify different types of beers.

  11. Determination of trace elements and calcium in bone of the human iliac crest by atomic absorption spectrometry.

    PubMed

    Scancar, J; Milacic, R; Benedik, M; Bukovec, P

    2000-03-01

    A rapid and reliable analytical method for the determination of trace elements in human bone by atomic absorption spectrometry is reported. Calcium was determined to estimate the homogeneity of samples. Human bone from the iliac crest was obtained at autopsy of adult subjects. Before analysis samples were decomposed by microwave digestion and acid digestion in a Parr bomb. Zinc, rubidium, strontium, calcium and iron were determined by flame atomic absorption spectrometry (FAAS) and aluminium, copper and lead by electrothermal atomic absorption spectrometry (ETAAS) at optimum measurement conditions. The results for the two digestion procedures agreed for zinc, rubidium and calcium within +/-5%, for copper within +/-7% and for strontium, iron, aluminium and lead within +/-10%. The repeatability of measurement (R.S.D.) for determination of calcium and trace elements after microwave digestion and acid digestion in a Parr bomb was tested in one representative autopsy bone sample by six parallel determinations. It was found to be better than +/-5% either for microwave digested samples or samples digested in a Parr bomb, for all elements determined by FAAS and ETAAS techniques. The accuracy of the applied digestion procedures was checked by analysis of trace elements in NIST SRM 1486 Bone Meal reference material. Good agreement of the results with certified values was obtained for both digestion procedures. The microwave procedure developed for digestion of small amounts of sample was applied in trace elements analysis of bone biopsy samples from dialysis patients.

  12. [Evaluation of uncertainty for determination of tin and its compounds in air of workplace by flame atomic absorption spectrometry].

    PubMed

    Wei, Qiuning; Wei, Yuan; Liu, Fangfang; Ding, Yalei

    2015-10-01

    To investigate the method for uncertainty evaluation of determination of tin and its compounds in the air of workplace by flame atomic absorption spectrometry. The national occupational health standards, GBZ/T160.28-2004 and JJF1059-1999, were used to build a mathematical model of determination of tin and its compounds in the air of workplace and to calculate the components of uncertainty. In determination of tin and its compounds in the air of workplace using flame atomic absorption spectrometry, the uncertainty for the concentration of the standard solution, atomic absorption spectrophotometer, sample digestion, parallel determination, least square fitting of the calibration curve, and sample collection was 0.436%, 0.13%, 1.07%, 1.65%, 3.05%, and 2.89%, respectively. The combined uncertainty was 9.3%.The concentration of tin in the test sample was 0.132 mg/m³, and the expanded uncertainty for the measurement was 0.012 mg/m³ (K=2). The dominant uncertainty for determination of tin and its compounds in the air of workplace comes from least squares fitting of the calibration curve and sample collection. Quality control should be improved in the process of calibration curve fitting and sample collection.

  13. Distinguishing plasmonic absorption modes by virtue of inversed architectures with tunable atomic-layer-deposited spacer layer

    NASA Astrophysics Data System (ADS)

    Zhang, Yun; Zhang, Kenan; Zhang, Tianning; Sun, Yan; Chen, Xin; Dai, Ning

    2014-12-01

    We demonstrated the distinguishing between plasmonic absorption modes by exploiting an inversed architecture with tunable atomic-layer-deposited dielectric spacer layer. The dielectric spacer layer was manipulated between the bottom metal-nanoparticle monolayer and the upper metal film to inspect the contributions of metal nanoparticles and dielectric film in a step-by-step manner. The experimental and simulated differences between the two peak absorption positions (Δf) and between the corresponding half width at half maxima (Δw) confirmed the evolutions of gap plasmon and interference-enhanced local surface plasmon resonance absorption modes in the plasmonic metamaterial absorbers (PMAs), which were useful for understanding the underlying mechanism of amorphous PMAs.

  14. A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy

    SciTech Connect

    Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas; Frank, Klaus

    2014-03-28

    We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0 mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5 × 10{sup 17} cm{sup −3} and peak N atom densities of 9.9 × 10{sup 17} cm{sup −3} are observed within the first ∼1.0 mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0 nm band of the vacuum ultraviolet spectrum.

  15. Separation and preconcentration of chromium species by selective absorption on Lemna minor and determination by slurry atomisation electrothermal atomic absorption spectrometry.

    PubMed

    Zhu, G; Li, S

    2001-08-01

    A novel method for the separation and preconcentration of Cr(III)/Cr(VI) with Lemna minor and determination by slurry atomization electrothermal atomic absorption spectrometry (ETAAS) was developed. A sample solution was added to a polyethylene beaker containing 10 mg of 160 mesh pre-treated Lemna minor, adjusted to pH 1.0, stirred for 8 min for selective absorption of Cr(III) and then centrifuged. The upper layer of solution was transferred into another polyethylene beaker containing 10 mg of 160 mesh pre-treated Lemna minor, adjusted to pH 5.0, stirred for 12 min for adsorption of the residual Cr(VI) and centrifuged. The two residues in two centrifuge tubes were washed twice with water, 2 ml of agar solution added, stirred for 2 min, then two slurries were prepared and used for the determination of Cr(III) and Cr(VI) by ETAAS. Detection limits (3sigma) of 0.01 microg L(-1) for Cr(III) and 0.03 microg L(-1) for Cr(VI) were obtained. The relative standard deviation was 2.8% for Cr(III) and 3.3% for Cr(VI) at the 1 microg L(-1) level. The method was applied to the determination of Cr(III)/Cr(VI) in water samples. The analytical recoveries of Cr(III) and Cr(VI) added to samples were 97-102 and 96-103%, respectively.

  16. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    USGS Publications Warehouse

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  17. Determination of yttrium and rare-earth elements in rocks by graphite-furnace atomic-absorption spectrometry.

    PubMed

    Gupta, J G

    1981-01-01

    With use of synthetic solutions and several international standard reference materials a method has been developed for determining traces of Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in rocks by electrothermal atomization in a pyrolytically-coated graphite furnace. Depending on the element, the sensitivity is of the order of 10(-9)-10(-12) g at 2500 degrees . To avoid matrix interferences the lanthanides are separated from the common elements by co-precipitation with calcium and iron as carriers. The data for Canadian reference rock SY-2 (syenite), U.S.G.S. reference rocks W-2 (diabase), DNC-1 (diabase) and BIR-1 (basalt), and South African reference rock NIM-18/69 (carbonatite) obtained by graphite-furnace atomization are compared with the values obtained by flame atomic-absorption. The results are in good agreement with literature values.

  18. A sensitive atomic-absorption spectrometric method for the determination of tin with atomization from impregnated graphite surfaces.

    PubMed

    Fritzsche, H; Wegscheider, W; Knapp, G; Ortner, H M

    1979-03-01

    The atomization of Sn from graphite surfaces is potentially hindered by reactions with the surface. The impregnation of graphite tubes with other carbide-forming elements (W, Zr, Ta, Mo) favourably alters the surface characteristics of the graphite furnace for the atomization of Sn. At the acid concentrations needed to prevent the hydrolysis of Sn, these surfaces are considerably more stable (even after more than 100 atomization cycles) than those of pyrolytic graphite. Two graphite furnaces of different design, the HGA 72 and the HGA 76, were tested. With impregnated graphite tubes the determination of Sn is possible in the HGA 72 with a detection limit of approximately 15 pg. In the HGA 76 the tin determination is vastly improved with respect to prolonged lifetime of the furnaces and stable signals over much longer periods of time. Detailed interference studies reveal that the use of the "gas stop" mode minimizes the influence of many ions that are frequently either introduced by the decomposition reagents or present in the sample itself. The practical potential of this method is demonstrated for the determination of Sn in a slag material and in copper- and aluminium-based alloys.

  19. [Determination of lithium in the oil field water by flame atomic absorption spectrometry].

    PubMed

    Yang, Hong-Jun; Ye, Xiu-Shen; Li, Bing; Wu, Zhi-Jian; Li, Wu

    2009-01-01

    Flame atomic absorption spectrometry was applied to the determination of micro amount of lithium in the oil field water of certain area. In order to determine which method is more appropriate for the determination of lithium content in the oil field water, standard curve method and standard addition method were compared. The effects of dilution, coexistent ions, and deionizers on the determination were studied. For the determination of lithium content in the same diluted oil field water samples, there exist obvious differences between the results obtained from standard addition method and standard curve method. Standard addition method gives results with a larger error, whereas standard curve method gives more accurate results. It is difficult to eliminate the interferences when the standard addition method is used. The standard curve method is found to be more suitable for the determination of micro amount of lithium in the oil field water for its accuracy, simplicity, and feasibility. When the standard curve method is used, both the determined lithium concentration and the recovery change with the dilution extent of the oil field water. In order to get an accurate result, the oil field water sample should be diluted to 1/200 or less. In this case, the recovery by standard addition method ranges from 94.3% to 96.9%. When sodium phosphate or sodium chloride is used as the deionizer, the recovery by standard addition method ranges from 94.6% to 98.6%, or from 94.2% to 96.3%. In the determination of lithium content in oil field water, there are larger experimental errors without the addition of any deionizer. When the concentration of coexistent ions is within an allowed range, the addition of sodium phosphate as a deionizer can eliminate the interferences of the coexistent ions with the determination of the lithium content. If sodium chloride is used as a deionizer, a more accurate result can be obtained when the sodium content in the samples is near the sodium

  20. [Study on determination of eight metal elements in Hainan arecanut leaf by flame atomic absorption spectrophotometry].

    PubMed

    Liu, Li-yun; Wang, Ping; Feng, Mei-li; Dong, Zhi-guo; Li, Jie

    2008-12-01

    Arecanut is a sort of palm that is important economic crop for the farmers in Hainan province of China, wherein there are many kinds of metal elements such as K, Ca, Na, Mg, Fe, Mn, Cu, Zn etc. These elements are important nutrition for the growth of arecanut. It is very valuable to study on the content of these metal elements in arecanut leaf in terms of plant nutriology of arecanut. The arecanut leaf in Wangling county, Hainan province of China was sampled by diagonal-field-sampling method. Refering to other plant sample determination by FAAS, the detailed studies are done with different digestion and determination methods. In the present paper the effects of mixed acid of HNO3-HClO4 digestion method on determining the amount of metal elements in the arecanut leaf by FAAS is reported, and another one is incineration digestion method. FAAS method was established for the determination of K, Ca, Mg, Na, Fe, Mn, Cu and Zn The samples were incinerated or heated with HNO3-HClO4 (4:1). In the meantime, the optimum parameters of FAAS and effects of different digestion methods on the results were discussed. The recovery rate of standard addition is 98.36%-102.38% in the first method; RSD is 0.42%-2.328% (n=6); The recovery rate of standard addition is 99.22%-103.72% in the second method; RSD is 0.58%-1.283 (n=6). The metal amount determined by the first method is lower than the second method, the ratio is 0.9703-0.9934. The two methods are satisfied, but the latter is better. It is precise enough to common experiment to use flame atomic absorption spectrophotometry with digestion by incineration If the especially precise experiment is required, the digestion methods with mixed acid of HNO3-HClO4 may be introduced. The paper introduced methods dependable for determination of some metal elements in order to study on some nutrient effects of these metal elements in arecanut.

  1. [Speciation analysis of trace elements Cu, Fe and Zn in serum by flame atomic absorption spectrophotometry].

    PubMed

    Hu, Jun; Chang, Yao-Ming; Gao, Shuang-Bin; Hai, Chun-Xu; Li, Jin-Sheng; Xie, Xiao-Ping

    2008-03-01

    Since biological functions of the elements are generally different, depending on their chemical forms, chemical speciation analysis is really important in metallomics research. Thus, multielement analysis and chemical speciation of the elements in serum were carried out in the present work. A hyphenated technique was developed for high-throughput speciation analysis of the copper, iron and zinc in serum by molecular biology technology and flame atomic absorption spectrophotometry (AAS). Here, Cu, Fe and Zn in serum were classifyied as the forms of combination and non-combination. The serum protein was precipitated by 60% concentration of ethanol under hypothermy. The forms of combination of Cu, Fe and Zn in serum which combined with proteins were in precipitations, and the forms of non-combination of Cu, Fe and Zn in serum, which were free ions, were in supernatant. The total amount of Cu, Fe and Zn in serum and the amount of the forms of non-combination of Cu, Fe and Zn were analyzed by AAS. The amount of the forms of combination of Cu, Fe and Zn was obtained by calculation. The detection limit of Cu in serum by the method is around and 9.84 x 10(-3) microg x mL(-1). For Fe and Zn, the detection limit is about 2.76 x 10(-2) microg x mL(-1) and 1.06 x 10(-3) microg x mL(-1), respectively. The percentage recovery of trace elements Cu, Fe and Zn by the proposed procedure is in the range 95.0%-101.0%, 95.0%-102.0% and 95.0%-103.0%, respectively. The relative standard deviation (RSD) of trace elements Cu, Fe and Zn in the serum is in the range 1.88%-2.26%, 0.56%-1.59% and 0.34%-1.36%, respectively. Speciation of trace elements Cu, Fe and Zn in the serum of SD rat were analyzed by the method.

  2. Optimized determination of calcium in grape juice, wines, and other alcoholic beverages by atomic absorption spectrometry.

    PubMed

    Olalla, Manuel; González, Maria Cruz; Cabrera, Carmen; Gimenez, Rafael; López, Maria Carmen

    2002-01-01

    This paper describes a study of the different methods of sample preparation for the determination of calcium in grape juice, wines, and other alcoholic beverages by flame atomic absorption spectrometry; results are also reported for the practical application of these methods to the analysis of commercial samples produced in Spain. The methods tested included dealcoholization, dry mineralization, and wet mineralization with heating by using different acids and/or mixtures of acids. The sensitivity, detection limit, accuracy, precision, and selectiviy of each method were established. Such research is necessary because of the better analytical indexes obtained after acid digestion of the sample, as recommended by the European Union, which advocates the direct method. In addition, although high-temperature mineralization with an HNO3-HCIO4 mixture gave the best analytical results, mineralization with nitric acid at 80 degrees C for 15 min gave the most satisfactory results in all cases, including those for wines with high levels of sugar and beverages with high alcoholic content. The results for table wines subjected to the latter treatment had an accuracy of 98.70-99.90%, a relative standard deviation of 2.46%, a detection limit of 19.0 microg/L, and a determination limit of 31.7 microg/L. The method was found to be sufficiently sensitive and selective. It was applied to the determination of Ca in grape juice, different types of wines, and beverages with high alcoholic content, all of which are produced and widely consumed in Spain. The values obtained for Ca were 90.00 +/- 20.40 mg/L in the grape juices, 82.30 +/- 23.80 mg/L in the white wines, 85.00 +/- 30.25 mg/L in the sweet wines, 84.92 +/- 23.11 mg/L in the red wines, 85.75 +/- 27.65 mg/L in the rosé wines, 9.51 +/- 6.65 mg/L in the brandies, 11.53 +/- 6.55 mg/L in the gin, 7.3 +/- 6.32 mg/L in the pacharán, and 8.41 +/- 4.85 mg/L in the anisettes. The method is therefore useful for routine analysis in the

  3. Determination of antimony, arsenic, bismuth, selenium, tellurium and tin by low pressure atomic absorption spectrometry with a quartz tube furnace atomizer and hydride generation with air addition.

    PubMed

    Zhang, B; Wang, Y; Wang, X; Chen, X; Feng, J

    1995-08-01

    A new method has been developed for the determination of antimony, arsenic, bismuth, selenium, tellurium and tin by hydride generation-atomic absorption spectrometry in an electrically heated quartz tube furnace under sub-atmospheric pressure. The hydride generator, operating at a pressure lower than atmospheric, is used to generate and collect the hydrides of these elements. A certain volume (at atmospheric pressure) of air is then added to the generator after the formation of the volatile hydride. The gaseous mixture of the hydride and air is drawn into an evacuated, heated quartz tube by a vacuum pump. The proposed method gives improved sensitivities and detection limits.

  4. [Ferric iron absorption in deltar p f F xoo, a gene deletion mutant of Xanthomonas oryzae pv. oryzae, assayed using atomic absorption spectrophotometry].

    PubMed

    Sun, Lei; Wu, Mao-Sen; He, Chen-Yang

    2010-04-01

    The ferric iron absorption is one of the most important limiting factors of bacterial growth of Xanthomonas oryzae pv. oryzae. It has been previously speculated that r p f F xoo might be involved in the ferric iron metabolism of the pathogen. In the present study, deltar p f F xoo, a gene deletion mutant, was generated from the wild-type strain PXO99A of Xoo through the homologous recombination, and Fe content was assayed using flame atomic absorption in PXO99A and deltar p f F xoo. The results indicated that the recovery was 99.7% and the relative standard deviation was 1.89 under optimized AAS operating conditions. The increase in Fe absorption in PXO99A and deltar p f F xoo was observed with the increasing time. However, the ferric content of deltar p f F xoo was significantly lower than that of PXO99A (P < 0.05). It is suggested that r p f F xoo is involved in iron metabolism in Xanthomonas oryzae pv. oryzae.

  5. Comparative determination of Ba, Cu, Fe, Pb and Zn in tea leaves by slurry sampling electrothermal atomic absorption and liquid sampling inductively coupled plasma atomic emission spectrometry.

    PubMed

    Mierzwa, J; Sun, Y C; Chung, Y T; Yang, M H

    1998-12-01

    The comparative determination of barium, copper, iron, lead and zinc in tea leaf samples by two atomic spectrometric techniques is reported. At first, slurry sampling electrothermal atomization atomic absorption spectrometry (ETAAS) was applied. The results of Ba and Pb determination were calculated using the method of standard additions, and results of Cu, Fe and Zn from the calibration graphs based on aqueous standards. These results were compared with the results obtained after microwave-assisted wet (nitric+hydrochloric+hydrofluoric acids) digestion in closed vessels followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination with the calibration by means of aqueous standards. The exception was lead determined after a wet digestion procedure by ETAAS. The accuracy of the studied methods was checked by the use of the certified reference material Tea GBW-07605. The recoveries of the analytes varied in the range from 91 to 99% for slurry sampling ETAAS, and from 92.5 to 102% for liquid sampling ICP-AES. The advantages of slurry sampling ETAAS method are simplicity of sample preparation and very good sensitivity. Slurry sampling ETAAS method is relatively fast but if several elements must be determined in one sample, the time of the whole microwave-assisted digestion procedure and ICP-AES determination will be shorter. However, worse detection limits of ICP-AES must also be taken into the consideration in a case of some analytes.

  6. Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization.

    PubMed

    Yamamoto, Yuhei; Shirasaki, Toshihiro; Yonetani, Akira; Imai, Shoji

    2015-01-01

    The measurement conditions for determining boron using graphite furnace-atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L(-1) when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS.

  7. Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

    NASA Astrophysics Data System (ADS)

    Campos, Reinaldo C.; Gonçalves, Rodrigo A.; Brandão, Geisamanda P.; Azevedo, Marlo S.; Oliveira, Fabiana; Wasserman, Julio

    2009-06-01

    The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C 18 column was used as stationary phase, and post column treatment was performed by UV irradiation (60 °C, 13 W). The eluate was then merged with 3 mol L - 1 HCl, reduction was performed by a NaBH 4 solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 µg L - 1 were obtained for ionic (Hg 2+) and HgCH 3+, for an injection volume of 200 µL. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sediments.

  8. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    SciTech Connect

    Erikat, I. A.; Hamad, B. A.

    2013-11-07

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

  9. Bias and uncertainty in the absorption emission measurement of atomic sodium density in the SSME exit plane

    NASA Technical Reports Server (NTRS)

    Bauman, Leslie E.

    1990-01-01

    The measurement of atomic sodium concentration in the TTB 019 firing of April 1990 is significant in that it represents the first measurement of density at the exit plane of the space shuttle main engine. The knowledge of the sodium density, combined with the certainty that the exit plane of the plume is optically thin at the sodium D-line wavelengths, provides essential information for evaluation of diagnostic techniques using sodium atoms, such as resonant Doppler velocimetry for temperature, pressure, and velocity through high resolution fluorescent lineshape analysis. The technique used for the sodium atom line transmission (SALT) measurements is that of resonant absorption emission using a hollow cathode lamp as the reference source. Through the use of two-dimensional kinetic (TDK) predictions of temperature and density for the flight engine case and radiative transfer calculations, this line-of-sight spectrally integrated transmission indicates a sodium atom concentration, i.e., mole fraction, of 0.91e-10. The subject of this paper is the assumptions and measurement uncertainties tied into the calculation. Because of the narrow shape of the source emission, the uncertainties in the absorption profile could introduce considerable bias in the measurement. The following were investigated: (1) the inclusion of hyperfine splitting of the D-lines in the calculation; (2) the use of the flight engine predictions of plume temperature and density versus those for the large throat engine; (3) the assumption of a Gaussian, i.e., Doppler, distribution for the source radiance with a temperature of 400 K; (4) the use of atomic collisional shift and width values for the work by Jongerius; and (5) a Doppler shift for a 7 degree outward velocity vector at the plume edge. Also included in the study was the bias introduced by an uncertainty in the measurement of the D1/D2 line ratio in the source.

  10. Lead determination at ng/mL level by flame atomic absorption spectrometry using a tantalum coated slotted quartz tube atom trap.

    PubMed

    Demirtaş, İlknur; Bakırdere, Sezgin; Ataman, O Yavuz

    2015-06-01

    Flame atomic absorption spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years, atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of µg/mL, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of the atom traps used to improve sensitivity. In atom trapping mode of SQT, analyte is trapped on-line in SQT for few minutes using ordinary sample aspiration, followed by the introduction of a small volume of organic solvent to effect the revolatilization and atomization of analyte species resulting in a transient signal. This system is economical, commercially available and easy to use. In this study, a sensitive analytical method was developed for the determination of lead with the help of SQT atom trapping flame atomization (SQT-AT-FAAS). 574 Fold sensitivity enhancement was obtained at a sample suction rate of 3.9 mL/min for 5.0 min trapping period with respect to FAAS. Organic solvent was selected as 40 µL of methyl isobutyl ketone (MIBK). To obtain a further sensitivity enhancement inner surface of SQT was coated with several transition metals. The best sensitivity enhancement, 1650 fold enhancement, was obtained by the Ta-coated SQT-AT-FAAS. In addition, chemical nature of Pb species trapped on quartz and Ta surface, and the chemical nature of Ta on quartz surface were investigated by X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. Raman spectrometric results indicate that tantalum is coated on SQT surface in the form of Ta2O5. XPS studies revealed that the oxidation state of Pb in species trapped on both bare and Ta coated SQT surfaces is +2. For the accuracy check, the analyses of standard reference material were performed by use of SCP SCIENCE EnviroMAT Low (EU-L-2) and results for Pb were to be in good agreement with

  11. High-resolution continuum source electrothermal atomic absorption spectrometry — An analytical and diagnostic tool for trace analysis

    NASA Astrophysics Data System (ADS)

    Welz, Bernhard; Borges, Daniel L. G.; Lepri, Fábio G.; Vale, Maria Goreti R.; Heitmann, Uwe

    2007-09-01

    The literature about applications of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) with electrothermal atomization is reviewed. The historic development of HR-CS AAS is briefly summarized and the main advantages of this technique, mainly the 'visibility' of the spectral environment around the analytical line at high resolution and the unequaled simultaneous background correction are discussed. Simultaneous multielement CS AAS has been realized only in a very limited number of cases. The direct analysis of solid samples appears to have gained a lot from the special features of HR-CS AAS, and the examples from the literature suggest that calibration can be carried out against aqueous standards. Low-temperature losses of nickel and vanadyl porphyrins could be detected and avoided in the analysis of crude oil due to the superior background correction system. The visibility of the spectral environment around the analytical line revealed that the absorbance signal measured for phosphorus at the 213.6 nm non-resonance line without a modifier is mostly due to the PO molecule, and not to atomic phosphorus. The future possibility to apply high-resolution continuum source molecular absorption for the determination of non-metals is discussed.

  12. Interference of nitrite and nitrogen dioxide on mercury and selenium determination by chemical vapor generation atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Nunes, Dayana Lopes; dos Santos, Eliane Pereira; Barin, Juliano Smanioto; Mortari, Sergio Roberto; Dressler, Valderi Luiz; de Moraes Flores, Érico Marlon

    2005-06-01

    In this study, a systematic investigation was performed concerning the interference of nitrogen oxides on the determination of selenium and mercury by hydride generation atomic absorption spectrometry (HG AAS) and cold vapor atomic absorption spectrometry (CV AAS). The effect of nitrate, nitrite and NO 2 dissolved in the condensed phase was evaluated. No effect of NO 3- on Se and Hg determination was observed up to 100 mg of sodium nitrate added to the reaction vessel. The Se signal was reduced by about 80% upon the addition of 6.8 mg NO 2-. For Hg, no interference of nitrite was observed up to 20 mg of NO 2-. A complete suppression of the Se signal was observed when gaseous NO 2 was introduced into analytical solutions. For Hg, a signal decrease between 8 and 13% occurred. For Se, bubbling argon or heating the solution was not able to recover the original absorbance values, whereas Hg signals were recovered with these procedures. When gaseous NO 2 was passed directly into the atomizer, Se signals decreased similarly to when NO 2 was bubbled in analytical solutions. The addition of urea, hydroxylamine hydrochloride and sulfamic acid (SA) was investigated to reduce the NO 2 effect in sample digests containing residual NO 2, but only SA was effective in reducing the interference. Based on the results, it is possible to propose the use of SA to prevent interferences in Se and Hg determinations by HG AAS and CV AAS, respectively.

  13. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    NASA Astrophysics Data System (ADS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; da Silva, Alessandra Furtado; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson José

    2005-06-01

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 °C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 °C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g -1.

  14. On the possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple atomic lines

    NASA Astrophysics Data System (ADS)

    Resano, M.; Rello, L.; Flórez, M.; Belarra, M. A.

    2011-05-01

    This paper explores the potential of commercially available high-resolution continuum source graphite furnace atomic absorption spectrometry instrumentation for the simultaneous or sequential monitoring of various atomic lines, in an attempt to highlight the analytical advantages that can be derived from this strategy. In particular, it is demonstrated how i) the monitoring of multiplets may allow for the simple expansion of the linear range, as shown for the measurement of Ni using the triplet located in the vicinity of 234.6 nm; ii) the use of a suitable internal standard may permit improving the precision and help in correcting for matrix-effects, as proved for the monitoring of Ni in different biological samples; iii) direct and multi-element analysis of solid samples may be feasible on some occasions, either by monitoring various atomic lines that are sufficiently close (truly simultaneous monitoring, as demonstrated in the determination of Co, Fe and Ni in NIST 1566a Oyster tissue) or, alternatively, by opting for a selective and sequential atomization of the elements of interest during every single replicate. Determination of Cd and Ni in BCR 679 White cabbage is attempted using both approaches, which permits confirming that both methods can offer very similar and satisfactory results. However, it is important to stress that the second approach provides more flexibility, since analysis is no longer limited to those elements that show very close atomic lines (closer than 0.3 nm in the ultraviolet region) with a sensitivity ratio similar to the concentration ratio of the analytes in the samples investigated.

  15. New Homogeneous Standards by Atomic Layer Deposition for Synchrotron X-ray Fluorescence and Absorption Spectroscopies.

    SciTech Connect

    Butterworth, A.L.; Becker, N.; Gainsforth, Z.; Lanzirotti, A.; Newville, M.; Proslier, T.; Stodolna, J.; Sutton, S.; Tyliszczak, T.; Westphal, A.J.; Zasadzinski, J.

    2012-03-13

    Quantification of synchrotron XRF analyses is typically done through comparisons with measurements on the NIST SRM 1832/1833 thin film standards. Unfortunately, these standards are inhomogeneous on small scales at the tens of percent level. We are synthesizing new homogeneous multilayer standards using the Atomic Layer Deposition technique and characterizing them using multiple analytical methods, including ellipsometry, Rutherford Back Scattering at Evans Analytical, Synchrotron X-ray Fluorescence (SXRF) at Advanced Photon Source (APS) Beamline 13-ID, Synchrotron X-ray Absorption Spectroscopy (XAS) at Advanced Light Source (ALS) Beamlines 11.0.2 and 5.3.2.1 and by electron microscopy techniques. Our motivation for developing much-needed cross-calibration of synchrotron techniques is borne from coordinated analyses of particles captured in the aerogel of the NASA Stardust Interstellar Dust Collector (SIDC). The Stardust Interstellar Dust Preliminary Examination (ISPE) team have characterized three sub-nanogram, {approx}1{micro}m-sized fragments considered as candidates to be the first contemporary interstellar dust ever collected, based on their chemistries and trajectories. The candidates were analyzed in small wedges of aerogel in which they were extracted from the larger collector, using high sensitivity, high spatial resolution >3 keV synchrotron x-ray fluorescence spectroscopy (SXRF) and <2 keV synchrotron x-ray transmission microscopy (STXM) during Stardust ISPE. The ISPE synchrotron techniques have complementary capabilities. Hard X-ray SXRF is sensitive to sub-fg mass of elements Z {ge} 20 (calcium) and has a spatial resolution as low as 90nm. X-ray Diffraction data were collected simultaneously with SXRF data. Soft X-ray STXM at ALS beamline 11.0.2 can detect fg-mass of most elements, including cosmochemically important oxygen, magnesium, aluminum and silicon, which are invisible to SXRF in this application. ALS beamline 11.0.2 has spatial resolution

  16. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    USGS Publications Warehouse

    Ball, J.W.; Nordstrom, D.K.

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of

  17. Flame and graphite furnace atomic absorption spectrometry for trace element determination in vegetable oils, margarine and butter after sample emulsification.

    PubMed

    Ieggli, C V S; Bohrer, D; Do Nascimento, P C; De Carvalho, L M

    2011-05-01

    Trace element analysis plays an important role in oil characterisation and in the detection of oil adulteration because the quality of edible oils and fats is affected by their trace metal content. In this study, the quantification of selected metals in various oils and fats (rice oil, canola oil, sunflower oil, corn oil, soy oil, olive oil, light margarine, regular margarine and butter) was carried out using flame atomic absorption spectrometry (FAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after sample emulsification. FAAS was used to determine the Na, K, Ca, Mg, Zn and Fe levels in the samples, while GFAAS was used for quantifying Cr, Ni, As, Pb, Cd, Cu and Mn, as these elements appeared in the samples at much lower concentrations. Tween-80 and Triton X-100 were employed as surfactants, and emulsions were prepared by a conventional method that involved heating and mixing of the constituents. Complete stabilisation was achieved through magnetic stirring for 15 min at room temperature. The evaluated figures of merit were linearity, accuracy and sensitivity, which were determined by the characteristic concentration and mass. Analysis of spiked samples demonstrated accuracy, which ranged from 90% (Na) to 112% (Fe) for FAAS and from 83% (Cd) to 121% (Pb) for GFAAS measurements. Atomic absorption spectrometry proved to be a promising approach for the analysis of metals in emulsified edible oils and fats. Additionally, under appropriate emulsification conditions (formulation, stirring time and temperature), the emulsions were homogeneous, had excellent stability, and had appropriate viscosity. The proposed method has proved to be simple, sensitive, reproducible, and economical.

  18. Determination of trace chromium in water by graphite furnace atomic absorption spectrophotometry after preconcentration on a soluble membrane filter

    SciTech Connect

    Gao Piying; Feng Ruolan; Zhang Huaizhu; Li Zhiqiang

    1998-04-01

    A new concentration and determination method has been described for the determination of lower than 0.1 {micro}g L{sup {minus}1} levels of chromium (VI) in water, based on the reaction between chromium (VI) and phenylfluorone (PF) to form an anionic chelate and the collection of the ternary ion-associate of the chelate with cetyltrimethylammonium bromide (CTMAB) (a cationic surfactant) on an organic solvent-soluble membrane filter. Determination of the solution obtained after dissolving the membrane and analyte in a suitable solvent is achieved using graphite furnace atomic absorption spectrophotometry. The ternary complex (Cr(VI)-PF-CTMAB = 1:2:2) is collected on a 0.45 {micro}m nitrocellulose filter and the filter and analyte are dissolved in a small volume of 2-methoxyethanol acidified with dilute sulfuric acid. The chromium is determined by graphite furnace atomic absorption spectrophotometry under optimum experimental conditions. A good linear relationship exists in the range 0.05--0.30 {micro}g chromium in 5.0 ml, with satisfactory reproducibility. The detection limit, defined as three times the standard deviation of the blank, is 0.06 {micro}g L{sup {minus}1} with 20 fold preconcentration. The ions normally present in water do not interfere under the experimental conditions used. The proposed method has been applied to the concentration and determination of chromium (VI) in water samples from several sources by means of direct graphic furnace atomic absorption spectrophotometry; the recoveries of chromium (VI) added to the samples are quantitative, and results found are satisfactory.

  19. Antimony in drinking water, red blood cells, and serum: development of analytical methodology using transversely heated graphite furnace atomization-atomic absorption spectrometry.

    PubMed

    Subramanian, K S; Poon, R; Chu, I; Connor, J W

    1997-05-01

    An atomic absorption spectrometric (AAS) method has been developed for determining microg/L levels of Sb in samples of water and blood. The AAS method is based on the concept of stabilized temperature platform furnace atomization (STPF) realized through the use of a transversely heated graphite atomizer (THGA) furnace, longitudinal Zeeman-effect background correction, and matrix modification with palladium nitrate-magnesium nitrate-nitric acid. The method of standard additions is not mandatory. The detection limit (3 standard deviations of the blank) is 2.6 microg Sb/L for the water, red blood cells (RBCs), and serum samples. Data are presented on the degree of accuracy and precision. The THGA-AAS method is simple, fast, and contamination-free because the entire operation from sampling to AAS measurement is carried out in the same tube. The method has been applied to the determination of Sb in some leachate tap water samples derived from a static copper plumbing system containing Sn/Sb solders, and in small samples (0.5 ml) of RBCs and serum derived from rats given Sb-supplemented drinking water.

  20. Optimization of a hydride generation metallic furnace atomic absorption spectrometry (HG-MF-AAS) method for tin determination: analytical and morphological parameters of a metallic atomizer.

    PubMed

    Moretto Galazzi, Rodrigo; Arruda, Marco Aurélio Zezzi

    2013-12-15

    The present work describes a metallic tube as hydride atomizer for atomic absorption spectrometry. Its performance is evaluated through tin determination, and the accuracy of the method assessed through the analysis of sediment and water samples. Some chemical parameters (referring to the generation of the hydride) such as acid, NaOH and THB concentrations, as well as physical parameters (referring to the transport of the hydride) such as carrier, acetylene, air flow-rates, flame composition, coil length, tube hole area, among others, are evaluated for optimization of the method. Scanning electron microscopy is used for evaluating morphological parameters in both new and used (after 150 h) tube atomizers. The method presents linear Sn concentration from 50 to 1000 µg L(-1) (r>0.9995; n=3) and the analytical frequency of ca. 40 h(-1). The limit of detection (LOD) is 7.1 µg L(-1) and the precision, expressed as RSD is less than 4% (200 µg L(-1); n=10). The accuracy is evaluated through reference materials, and the results are similar at 95% confidence level according to the t-test.

  1. Microwave-assisted extraction and ultrasonic slurry sampling procedures for cobalt determination in geological samples by electrothermal atomic absorption spectroscopy.

    PubMed

    Felipe-Sotelo, M; Carlosena, A; Fernández, E; López-Mahía, P; Muniategui, S; Prada, D

    2004-06-17

    Slurry sampling is compared to microwave-assisted acid digestion for cobalt determination in soil/sediment samples by electrothermal atomic absorption spectrometry (ETAAS). Furnace temperature programs and appropriate amounts of three chemical modifiers were optimised in order to get the highest signals and good separations between the atomic and background signals. Using nitric acid (0.5% (v/v)) as liquid medium, no chemical modifier was needed. The detection limit, based on integrated absorbance, was 0.04mugg(-1) for digests and slurries. Within-batch precision and analytical recoveries were satisfactory for both procedures. Accuracy was tested by analysing a reference soil and a sediment from IRMM. The methods were further compared employing a set of roadside soils and estuarine sediments. As no significant differences (95% confidence) were found, practical analytical properties were suggested in order to select one of them.

  2. An atomic absorption spectrophotometric method for the determination of trace amounts of zinc in canned juices after ion exchange separation.

    PubMed

    Aziz-Alrahman, A M

    1984-01-01

    An atomic absorption spectrophotometric method is described for the determination of microgram quantities of zinc in canned juices. After sample digestion in concentrated nitric acid, the solution is evaporated till near dryness, and then a solution of 2 M HCl is added to form tetrachlorozincate (II) ion. This acid solution, containing the zinc complex is passed through an ion-exchange column (anion exchange resin, chloride form, which is preconditioned by passing 1 M HCl solution). Zinc is eluted from the column with 0.01 M HCl solution. After evaporation to dryness, the residue is dissolved in 1% (v/v) HNO3, and then atomized into an air-acetylene flame. The limit of detection of the method is 0.15 micrograms ml-1 Zn. The analytical aspects of the proposed method, including the standard addition technique are discussed.

  3. Hydride generation and condensation flame atomic absorption spectroscopic determination of antimony in raw coffee beans and processed coffee.

    PubMed

    Kuennen, R W; Hahn, M H; Fricke, F L; Wolnik, K A

    1982-09-01

    A method was developed for determining Sb at nanogram per gram levels in raw coffee beans and processed coffee. The procedure uses either total acid digestion or extraction with 6M HCl followed by hydride generation/condensation with subsequent revolatilization of stibine (SbH3) and detection by flame atomic absorption spectroscopy. The lowest quantifiable level, based on a 2 g (dry weight) sample, is 2 ng Sb/g. The results of recoveries on spiked samples, precision studies on composited coffee samples, and the analysis of National Bureau of Standards Standard Reference Materials demonstrate the reliability and accuracy of the procedure. Sb concentrations in coffee samples were verified by neutron activation analysis and inductively coupled plasma atomic emission spectroscopy. Advantages of the method compared with the AOAC colorimetric procedure and hydride generation without condensation are discussed.

  4. Determination of bismuth in environmental samples by slurry sampling graphite furnace atomic absorption spectrometry using combined chemical modifiers.

    PubMed

    Dobrowolski, Ryszard; Dobrzyńska, Joanna; Gawrońska, Barbara

    2015-01-01

    Slurry sampling graphite furnace atomic absorption spectrometry technique was applied for the determination of Bi in environmental samples. The study focused on the effect of Zr, Ti, Nb and W carbides, as permanent modifiers, on the Bi signal. Because of its highest thermal and chemical stability and ability to substantially increase Bi signal, NbC was chosen as the most effective modifier. The temperature programme applied for Bi determination was optimized based on the pyrolysis and atomization curves obtained for slurries prepared from certified reference materials (CRMs) of the soil and sediments. To overcome interferences caused by sulfur compounds, Ba(NO₃)₂ was used as a chemical modifier. Calibration was performed using the aqueous standard solutions. The analysis of the CRMs confirmed the reliability of the proposed analytical method. The characteristic mass for Bi was determined to be 16 pg with the detection limit of 50 ng/g for the optimized procedure at the 5% (w/v) slurry concentration.

  5. Determination of cadmium and lead in edible oils by electrothermal atomic absorption spectrometry after reverse dispersive liquid-liquid microextraction.

    PubMed

    López-García, Ignacio; Vicente-Martínez, Yesica; Hernández-Córdoba, Manuel

    2014-06-01

    The dispersive liquid-liquid microextraction of edible oils with a low volume of an acidic solution in the presence of isopropyl alcohol allows cadmium and lead to be completely separated into the aqueous phase. After centrifugation, the metals are determined by electrothermal atomization atomic absorption spectrometry using a palladium salt for chemical modification in the heating cycle. Using a 10 g oil sample, the enrichment factor is 140, which permits detection limits of 0.6 and 10 ng kg(-1) for cadmium and lead, respectively. The results agree with those obtained after sample mineralization. Data for the cadmium and lead levels for 15 samples of different characteristics are given. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Determination of cadmium by electrothermal atomic absorption spectrometry after microwave-assisted digestion of animal tissues and sewage sludges.

    PubMed

    Chakraborty, R; Das, A K; Cervera, M L; De La Guardia, M

    1996-04-01

    The determination of cadmium in different sample types has been carried out by electrothermal atomization atomic absorption spectrometry with D(2)-background correction using a unpyrocoated graphite tube, after pressurized microwave-assisted digestion. Five chemical modifiers [(NH(4))(2)HPO(4), Pd(NO)(3))(2), Ni(NO(3))(2), thiourea and Triton X-100] have been assayed and nickel nitrate has been found to be most effective for an accurate determination of cadmium in mussel tissue, pig kidney and sewage sludge. The characteristic mass of the method is of the order of 1 pg and the limit of detection is lower than 0.1 ng/ml.

  7. Determination of nickel in the serum of occupationally exposed workers, by means of flame atomic-absorption spectroscopy.

    PubMed

    Ghe, A M; Lippolis, M T; Pastorelli, L

    1985-10-01

    A flame atomic-absorption spectroscopy method for determination of nickel in the serum of occupationally exposed subjects has been developed. Trichloroacetic add is utilized for precipitating proteins and freeing bound nickel; sodium diethyldithiocarbamate is used as complexing agent and isopropyl acetate as the solvent for extraction. The method is characterized by good accuracy, precision and sensitivity, over a concentration range up to about 20 ng/ml. Calcium, which is present in serum in great excess with respect to typical nickel concentrations, does not interfere in the determination of the latter.

  8. [Determination of Pb and Al in blood and hair of child using transverse heated graphite furnace atomic absorption spectroscopy].

    PubMed

    Niu, Feng-lan; Xie, Wen-bing; Li, Chen-xu; Dong, Wei-yan

    2005-04-01

    Pb and Al in blood and hair of child were determined by transverse heated graphite furnace atomic absorption spectrometry with NH4H2PO4 and Mg(NO3)2 as a modifier, which enhanced the temperature of ashing, eliminated the matrix interference and memorial effect. The method is rapid, simple and accurate. The characteristic mass of the method was 2.3 x 10(-11) g and 2.2 x 10(-11) g for Pb and Al respectively. The relative standard deviation of Pb and Al was 3.0% and 11.4%, respectively, and the recovery was 96%-102%.

  9. Determination of silver in soils, sediments, and rocks by organic-chelate extraction and atomic absorption spectrophotometry

    USGS Publications Warehouse

    Chao, T.T.; Ball, J.W.; Nakagawa, H.M.

    1971-01-01

    A useful method for the determination of silver in soil, sediment, and rock samples in geochemical exploration has been developed. The sample is digested with concentrated nitric acid, and the silver extracted with triisooctyl thiophosphate (TOTP) in methyl isobutyl ketone (MIBK) after dilution of the acid digest to approximately 6 M. The extraction of silver into the organic extractant is quantitative and not affected by the nitric acid concentration from 4 M to 8 M, or by different volumes of TOTP-MIBK. The extracted silver is stable and remains in the organic phase up to several days. The silver concentration is determined by atomic absorption spectrophotometry. ?? 1971.

  10. Ion-exchange separation and atomic-absorption determination of fifteen major, minor and trace elements in silicates.

    PubMed

    Mazzuootelli, A; Frache, R; Dadone, A; Baffi, F

    A scheme of ion-exchange separation of fifteen elements (major, minor and trace) determined mainly by atomic-absorption spectrophotometry (Ti by colorimetry) is applied to rock, mineral and ceramic analysis. Mn, Cu, Co, Fe and Zn are separated on an anion-exchanger and Li, Na, K, Mg, Ca, Sr, Ti, Al, Ni and Ba on a cation-exchanger. The method has been tested by analysis of a synthetic mixture of the fifteen ions in the ratios in common rock samples, and of various international standards (100-mg samples).

  11. A photon counting and a squeezing measurement method by the exact absorption and dispersion spectrum of Λ-type Atoms.

    PubMed

    Naeimi, Ghasem; Alipour, Samira; Khademi, Siamak

    2016-01-01

    Recently, the master equations for the interaction of two-mode photons with a three-level Λ-type atom are exactly solved for the coherence terms. In this paper the exact absorption spectrum is applied for the presentation of a non-demolition photon counting method, for a few number of coupling photons, and its benefits are discussed. The exact scheme is also applied where the coupling photons are squeezed and the photon counting method is also developed for the measurement of the squeezing parameter of the coupling photons.

  12. X-ray absorption spectroscopy and atomic force microscopy study of bias-enhanced nucleation of diamond films

    SciTech Connect

    Garcia, M.M.; Jimenez, I.; Vazquez, L.; Gomez-Aleixandre, C.; Albella, J.M.; Sanchez, O.; Terminello, L.J.; Himpsel, F.J.

    1998-04-01

    The bias-enhanced nucleation of diamond on Si(100) has been studied by x-ray absorption near-edge spectroscopy (XANES) and atomic force microscopy, two techniques well suited to characterize nanometric crystallites. Diamond nuclei of {approximately}15nm are formed after 5 min of bias-enhanced treatment. The number of nuclei and its size increases with the time of application of the bias voltage. A nanocrystalline diamond film is attained after 20 min of bias-enhanced nucleation. At the initial nucleation stages, the Si substrate appears covered with diamond crystallites and graphite, without SiC being detected by XANES. {copyright} {ital 1998 American Institute of Physics.}

  13. An abbreviated fire-assay atomic-absorption method for the determination of gold and silver in ores and concentrates.

    PubMed

    Moloughney, P E

    1977-02-01

    A simplified scheme, combining aspects of the classical fire-assay with an atomic-absorption finish, is presented for the determination of gold and silver in ores and concentrates. The lead assay button is scorified to approximately 2 g and then parted in nitric acid. The filtrate is analysed by AAS for silver; the residue is dissolved in aqua regia and subsequently analysed for gold by AAS. The precision and accuracy of the method have been established by application to four diverse certified reference materials. The proposed method eliminates the need for such time-consuming steps as inquartation, multiple scorifications, and cupellation.

  14. Speciation of methyl- and butyltin compounds and inorganic tin in oysters by hydride generation atomic absorption spectrometry

    SciTech Connect

    Han, J.S.; Weber, J.H.

    1988-02-15

    Because of the toxicity of tributyltin originating from many antifouling marine paints, there is much concern about its effect on aquatic life and, particularly, on shellfish. This paper describes speciation of inorganic tin, methyltin compounds, and butyltin compounds from oyster samples. The authors validated the hydride generation atomic absorption spectrophotometric technique by demonstrating ca. 100% recovery from spiked samples and by the absence of any organotin decomposition products. Absolute detection limits (3sigma) are 1.1-2.5 ng for 0.1-g oyster samples (wet weight). This method is superior to published techniques because of careful validation, low limits of detection, and minimal sample manipulation.

  15. Determination of gold in copper-bearing sulphide ores and metallurgical flotation products by atomic-absorption spectrometry.

    PubMed

    Strong, B; Murray-Smith, R

    1974-12-01

    A method is described which is specific for the determination of gold in sulphide copper ores and concentrates. Direct decomposition with aqua regia was found to be incomplete. A carefully controlled roasting stage followed by treatment with hydrochloric acid and then aqua regia was effective for dissolving all the gold. The gold is extracted into 4-methylpentan-2-one (methyli-sobutylketone) then aspirated into a very lean air-acetylene flame and the gold determined by atomic-absorption spectrometry. No interferences were observed from large concentrations of copper, iron or nickel.

  16. Optimisation of flame parameters for simultaneous multi-element atomic absorption spectrometric determination of trace elements in rocks

    USGS Publications Warehouse

    Kane, J.S.

    1988-01-01

    A study is described that identifies the optimum operating conditions for the accurate determination of Co, Cu, Mn, Ni, Pb, Zn, Ag, Bi and Cd using simultaneous multi-element atomic absorption spectrometry. Accuracy was measured in terms of the percentage recoveries of the analytes based on certified values in nine standard reference materials. In addition to identifying optimum operating conditions for accurate analysis, conditions resulting in serious matrix interferences and the magnitude of the interferences were determined. The listed elements can be measured with acceptable accuracy in a lean to stoicheiometric flame at measurement heights ???5-10 mm above the burner.

  17. Graphite furnace atomic absorption spectrophotometry--a novel method to quantify blood volume in experimental models of intracerebral hemorrhage.

    PubMed

    Kashefiolasl, Sepide; Foerch, Christian; Pfeilschifter, Waltraud

    2013-02-15

    Intracerebral hemorrhage (ICH) accounts for 10% of all strokes and has a significantly higher mortality than cerebral ischemia. For decades, ICH has been neglected by experimental stroke researchers. Recently, however, clinical trials on acute blood pressure lowering or hyperacute supplementation of coagulation factors in ICH have spurred an interest to also design and improve translational animal models of spontaneous and anticoagulant-associated ICH. Hematoma volume is a substantial outcome parameter of most experimental ICH studies. We present graphite furnace atomic absorption spectrophotometric analysis (AAS) as a suitable method to precisely quantify hematoma volumes in rodent models of ICH.

  18. New method for determining relative oscillator strengths of atoms through combined absorption and emission measurements - Application to titanium /Ti I/

    NASA Technical Reports Server (NTRS)

    Cardon, B. L.; Smith, P. L.; Whaling, W.

    1979-01-01

    The paper introduces a procedure that combines measurements of absorption and emission by atoms to obtain relative oscillator strengths that are independent of temperature determination in the sources and of assumptions regarding local thermodynamic equilibrium. The experimental observations are formed into sets of transitions and required to satisfy defined ratios. The procedure is illustrated with the published data of Whaling et al. and Smith and Kuehne for 16 transitions in Ti I. It is shown that the relative oscillator strengths resulting from this procedure have calculated uncertainties between 5 and 17% (about 95% confidence level). Evidence is presented to suggest that these uncertainties have been overestimated.

  19. Determination of Chlorine in Milk via Molecular Absorption of SrCl Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry.

    PubMed

    Ozbek, Nil; Akman, Suleyman

    2016-07-20

    Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1).

  20. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    ERIC Educational Resources Information Center

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  1. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    ERIC Educational Resources Information Center

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  2. Investigation of an alternating current plasma as an element selective atomic emission detector for high-resolution capillary gas chromatography and as a source for atomic absorption and atomic emission spectrometry

    SciTech Connect

    Ombaba, J.M.

    1992-01-01

    This thesis deals with the construction and evaluation of an alternating current plasma (ACP) as an element-selective detector for high resolution capillary gas chromatography (GC) and as an excitation source for atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). The plasma, constrained in a quartz discharge tube at atmospheric pressure, is generated between two copper electrodes and utilizes helium as the plasma supporting gas. The alternating current plasma power source consists of a step-up transformer with a secondary output voltage of 14,000 V at a current of 23 mA. The chromatographic applications studied included the following: (1) the separation and selective detection of the organotin species, tributyltin chloride (TBT) and tetrabutyltin (TEBT), in environmental matrices including mussels (mytilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienylmanganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer was utilized as a sample introduction device for aqueous solutions when the ACP was employed as an atomization source for atomic absorption spectrometry and as an excitation source for atomic emission spectrometry. Plasma diagnostic parameters studied include spatial electron number density across the discharge tube, electronic, excitation and ionization temperatures. Interference studies both in absorption and emission modes were considered. The evaluation of a computer-aided optimization program, Drylab GC, using spearmint oil and Environmental Protection Agency (EPA) standard mixture as probes is discussed. The program is used for separation optimization and prediction of gas chromatographic parameters. The program produces a relative resolution map (RRM) which guides the analyst in selecting the most favorable temperature programming rate for the separation.

  3. Tungsten permanent chemical modifier for fast estimation of Se contents in soil by graphite furnace atomic absorption spectrometry.

    PubMed

    Rosa, Cassia Regina; Freschi, GianPaulo Giovanni; De Moraes, Mercedes; Gomes Neto, José Anchieta; Nóbrega, Joaquim Araújo; Araújo Nogueira, Ana Rita; Sacramento, Luís Vitor

    2003-07-02

    A tungsten carbide coating on the integrated platform of a transversely heated graphite atomizer was used as a modifier for the direct determination of Se in soil extracts by graphite furnace atomic absorption spectrometry. Diethylenetriaminepentaacetic acid (0.0050 mol L(-1)) plus ammonium hydrogencarbonate (1.0 mol L(-1)) extracted predominantly available inorganic selenate from soil. The formation of a large amount of carbonaceous residue inside the atomizer was avoided with a first pyrolysis step at 600 degrees C assisted by air during 30 s. For 20 microL of soil extracts delivered to the atomizer and calibration by matrix matching, an analytical curve (10.0-100 microgram of L(-1)) with good linear correlation (r = 0.999) between integrated absorbance and analyte concentration was established. The characteristic mass was approximately 63 pg of Se, and the lifetime of the tube was approximately 750 firings. The limit of detection was 1.6 microgram L(-1), and the relative standard deviations (n = 12) were typically <4% for a soil extract containing 50 microgram of L(-1). The accuracy of the determination of Se was checked for soil samples by means of addition/recovery tests. Recovery data of Se added to four enriched soil samples varied from 80 to 90% and indicated an accurate method.

  4. Nonlinear absorption in ionic liquids with transition metallic atoms in the anion

    NASA Astrophysics Data System (ADS)

    Nóvoa-López, José A.; López Lago, Elena; Seijas, Julio A.; Pilar Vázquez-Tato, M.; Troncoso, Jacobo; de la Fuente, Raúl; Salgueiro, José R.; Michinel, Humberto

    2016-02-01

    Nonlinear absorption has been investigated by open aperture Z-scan in ionic liquids obtained by combination of 1-butyl-3-methyl-imidazolium cations with anions containing a transition metal (Co, Zn, Cu or Ni) and thiocyanate groups. The laser source was a Ti:Sapphire oscillator (80-fs pulses, λ = 810 nm, repetition rate of 80.75 MHz). All liquids present quite low heat capacities that favor the development of strong thermal effects. Thermal effects and nonlinear absorption make them potential materials for optical limiting purposes.

  5. Theory of x-ray absorption by laser-dressed atoms

    NASA Astrophysics Data System (ADS)

    Buth, Christian; Santra, Robin

    2007-03-01

    An ab initio theory is devised for the x-ray photoabsorption cross section of atoms in the field of a moderately intense optical laser ( 800nm , 1013W/cm2 ). The laser dresses the core-excited atomic states, which introduces a dependence of the cross section on the angle between the polarization vectors of the two linearly polarized radiation sources. We use the Hartree-Fock-Slater approximation to describe the atomic many-particle problem in conjunction with a nonrelativistic quantum-electrodynamic approach to treat the photon-electron interaction. The continuum wave functions of ejected electrons are treated with a complex absorbing potential that is derived from smooth exterior complex scaling. The solution to the two-color (x-ray plus laser) problem is discussed in terms of a direct diagonalization of the complex symmetric matrix representation of the Hamiltonian. Alternative treatments with time-independent and time-dependent non-Hermitian perturbation theories are presented that exploit the weak interaction strength between x rays and atoms. We apply the theory to study the photoabsorption cross section of krypton atoms near the K edge. A pronounced modification of the cross section is found in the presence of the optical laser.

  6. CoxFey@C Composites with Tunable Atomic Ratios for Excellent Electromagnetic Absorption Properties

    PubMed Central

    Lv, Hualiang; Ji, Guangbin; Zhang, Haiqian; Li, Meng; Zuo, Zhongzheng; Zhao, Yue; Zhang, Baoshan; Tang, Dongming; Du, Youwei

    2015-01-01

    The shell on the nano-magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonmagnetic shell will decrease the integral magnetic loss and thus weaken the electromagnetic absorption. However, maintaining the original absorption properties of the magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3−xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting magnetic loss ability. Meanwhile, the carbon shell may increase the integral dielectric loss. The resulting composite shows excellent electromagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to −23 dB with an effective frequency range of 7 GHz (11–18 GHz). The mechanisms of the improved microwave absorption properties are discussed. PMID:26659124

  7. CoxFey@C Composites with Tunable Atomic Ratios for Excellent Electromagnetic Absorption Properties

    NASA Astrophysics Data System (ADS)

    Lv, Hualiang; Ji, Guangbin; Zhang, Haiqian; Li, Meng; Zuo, Zhongzheng; Zhao, Yue; Zhang, Baoshan; Tang, Dongming; Du, Youwei

    2015-12-01

    The shell on the nano-magnetic absorber can prevent oxidation, which is very important for its practical utilization. Generally, the nonmagnetic shell will decrease the integral magnetic loss and thus weaken the electromagnetic absorption. However, maintaining the original absorption properties of the magnetic core is a major challenge. Here, we designed novel and facile CoxFey@C composites by reducing CoxFe3-xO4@phenolic resin (x = 1, 0.5 and 0.25). High saturation magnetization value (Ms) of CoxFey particle, as a core, shows the interesting magnetic loss ability. Meanwhile, the carbon shell may increase the integral dielectric loss. The resulting composite shows excellent electromagnetic absorption properties. For example, at a coating thickness of 2 mm, the RLmin value can reach to -23 dB with an effective frequency range of 7 GHz (11-18 GHz). The mechanisms of the improved microwave absorption properties are discussed.

  8. Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: method optimization and evaluation of analytical performance.

    PubMed

    Kratzer, Jan; Boušek, Jaroslav; Sturgeon, Ralph E; Mester, Zoltán; Dědina, Jiří

    2014-10-07

    Atomization of bismuth hydride in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized and the performance of this device compared to that of a conventional quartz tube atomizer (QTA) for atomic absorption spectrometry (AAS). Modification of the inner surface of the DBD atomizer using dimethyldichlorsilane (DMDCS) was essential since it improved sensitivity by a factor of 2-4. Argon, at a flow rate of 125 mL min(-1), was the best DBD discharge gas. Free Bi atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. The detection limit for Bi (1.1 ng mL(-1)) is worse than with the QTA (0.16 ng mL(-1) Bi). A poorer detection limit compared to a QTA is a consequence of the shorter optical path of the DBD. Moreover, the lower atomization efficiency and/or faster decay of free atoms in the DBD has to be considered. The performance of the DBD as an atomizer reflects both effects, i.e., atomization efficiency and free atom decay, was estimated to be 65% of that of the externally heated quartz tube atomizer. Nevertheless, this hydride generation DBD-AAS approach can be used for the routine determination of Bi, providing repeatability and accuracy comparable to that reached with a QTA, as demonstrated by analysis of NIST SRM 1643e (trace elements in water). The potential of in-atomizer preconcentration in a DBD atomizer is outlined.

  9. Colorimetric and atomic absorption spectrometric determination of mucolytic drug ambroxol through ion-pair formation with iron and thiocyanate.

    PubMed

    Levent, Abdulkadir; Sentürk, Zühre

    2010-09-01

    Colorimetric and atomic absorption spectrometric methods have been developed for the determination of mucolytic drug Ambroxol. These procedures depend upon the reaction of iron(III) metal ion with the drug in the presence of thiocyanate ion to form stable ion-pair complex which extractable chloroform. The red-coloured complex was determined either colorimetrically at 510 nm or by indirect atomic absorption spectrometry (AAS) via the determination of the iron content in the formed complex. The optimum experimental conditions for pH, concentrations of Fe(3+) and SCN(-), shaking time, phase ratio, and the number of extractions were determined. Under the proposed conditions, linearity was obeyed in the concentration ranges 4.1x10(-6) - 5.7x10(-5) M (1.7-23.6 µg mL(-1)) using both methods, with detection limits of 4.6x10(-7) M (0.19 µg mL(-1)) for colorimetry and 1.1x10(-6) M (0.46 µg mL(-1)) for AAS. The proposed methods were applied for the determination of Ambroxol in tablet dosage forms. The results obtained were statistically analyzed and compared with those obtained by applying the high-performance liquid chromatographic method with diode-array detection.

  10. Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.

    PubMed

    Saracoglu, Sibel; Soylak, Mustafa; Cabuk, Dilek; Topalak, Zeynep; Karagozlu, Yasemin

    2012-01-01

    The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.

  11. Low-level (PPB) determination of cisplatin in cleaning validation (rinse water) samples. I. An atomic absorption spectrophotometric method.

    PubMed

    Raghavan, R; Mulligan, J A

    2000-04-01

    Suitable analytical methods are required for quantitative determination of trace levels of ingredients in samples obtained for purposes of cleaning validation. We describe below an atomic absorption method for the quantitation of cisplatin, an antineoplastic agent, in aqueous samples. Cisplatin was reacted with diethyldithiocarbamic acid (DDTC), sodium salt, to yield a platinum-DDTC (Pt-DDTC) complex. The Pt-DDTC chelate was extracted into methylene chloride, the extract was mixed with acetonitrile, and the platinum content was then determined using a Zeeman atomic absorption (AA) spectrophotometer. The extraction conditions and AA experimental conditions were set up such that the detection level could be extended to 0.5 ng/ml. Reproducible results were obtained at a quantitative working standard concentration of 5 PPB. The absorbance response was found to be a linear function of cisplatin concentration in the region between 0.5 PPB and 20 PPB, which is about 10% to 400% of the target analyte concentration of 5 PPB. The target analyte concentration was set at 5 PPB such that it was at least 10 times the detection limit of about 0.5 PPB.

  12. Direct determination of Cd, Cu and Pb in wines and grape juices by thermospray flame furnace atomic absorption spectrometry.

    PubMed

    Schiavo, Daniela; Neira, José Y; Nóbrega, Joaquim A

    2008-09-15

    The applicability of thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was evaluated for direct determination of Cu, Cd and Pb in wines and grape juices. The developed procedure does not require preliminary acid digestion of the samples. The optimum conditions for determination of Cu, Cd and Pb in wines were studied and the performance was compared to those typically obtained by flame atomic absorption spectrometry (FAAS). A sample volume of 150 microL was introduced into a heated nickel tube at a flow rate of 0.54 mLmin(-1) and 0.14 molL(-1) HNO(3) was used as sample carrier flowing at 2.5 mLmin(-1) for determining all analytes. The effect of ethanol concentrations on Cu, Cd and Pb absorbance signals were studied. All determinations were carried out by adopting optimized conditions and quantification was based on the standard additions method. Limits of detection (LOD) of 12.9, 1.8 and 5.3 microgL(-1) (n=14) for Cu, Cd and Pb, respectively, were obtained for wine samples (3sigma(blank)/slope, n=14). Relative standard deviations (R.S.D., %) of 2.7, 2.1 and 2.6 for Cu, Cd and Pb, were obtained (n=6) for wine samples. The values determined for grape juice samples were similar to these ones. The analytical throughput was 45 determinations h(-1) and accuracy was checked by addition-recovery experiments.

  13. Determination of total selenium in pharmaceutical and herbal supplements by hydride generation and graphite furnace atomic absorption spectrometry.

    PubMed

    Kazi, Tasneem G; Kolachi, Nida F; Afridi, Hassan I; Brahman, Kapil Dev; Shah, Faheem

    2014-01-01

    The total selenium (Se) was determined in herbal and pharmaceutical supplements used for liver diseases. The total Se contents were determined in different pharmaceutical and herbal supplements by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after microwave-assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material and the standard addition method. The recoveries of total Se were 99.4 and 99.0% for HGAAS and GFAAS, respectively. The precision of the techniques expressed as RSD were 2.34 and 4.54% for HGAAS and GFAAS measurements, respectively. The LOD values for HGAAS and GFAAS were 0.025 and 0.052 pglg, respectively. The concentrations of Se in pharmaceutical and herbal supplements were found in the range of 19.2-53.8 and 25.0-42.5 pg/g, respectively, corresponding to 35-76% and 45-76% of the total recommended dose of Se for adults.

  14. A simple indirect automatic method to determine total iodine in milk products by flame atomic absorption spectrometry.

    PubMed

    Yebra, M C; Bollaín, M H

    2010-07-15

    A simple, precise and accurate automatic method for the determination of total iodine in milk products by indirect atomic absorption spectrometry is proposed. Iodide in solutions resulting from alkaline ashing of samples is precipitated with silver ion in a precipitation-dissolution flow manifold, which allows performing on-line the retention of the silver iodide precipitate formed on a filter, its wash with diluted ammonia and its dissolution with a diluted thiosulfate solution. Dissolved silver is also determined on-line by flame atomic absorption, and the achieved amount of this metal is proportional to that of iodine in the sample. The proposed method is very selective, avoids interferences from anions present in the samples, which can be also precipitated with silver, because these silver compounds are dissolved with ammonia at the washing step. This method allows the determination of iodine in the range 0.011-0.35 microg mL(-1) with a relative standard deviation between 1.3 and 6.8% at a rate of ca. 17 samplesh(-1).

  15. Contents of cadmium, mercury and lead in fish from the Atlantic sea (Morocco) determined by atomic absorption spectrometry.

    PubMed

    Chahid, Adil; Hilali, Mustapha; Benlhachimi, Abdeljalil; Bouzid, Taoufiq

    2014-03-15

    As a part of a specific monitoring program, lead (Pb) cadmium (Cd) and mercury (Hg) concentrations in important species of fish from various fishing ports of the southern Kingdom of Morocco (Sardina pilchardus, Scomber scombrus, Plectorhinchus mediterraneus, Trachurus trachurus, Octopus vulgaris, Boops boops, Sarda sarda, Trisopterus capelanus, and Conger conger) were investigated by the Moroccan Reference Laboratory (NRL) for trace elements in foodstuffs of animal origin. The samples were analysed for lead and cadmium by a graphite furnace atomic absorption spectrometry (GFAAS); and for mercury by cold vapour atomic absorption spectrometry (CVAAS). The results were expressed as μg/g of wet weight (w/w). The levels of Cd, Pb and Hg in muscles of fish were 0.009-0.036, 0.013-0.114 and 0.049-0.194 μg/g, respectively. The present study showed that different metals were present in the sample at different levels but within the maximum residual levels prescribed by the EU for the fish and shellfish from these areas, in general, should cause no health problems for consumers.

  16. Electrothermal atomic absorption spectrometric determination of cadmium and lead with stabilized phosphate deposited on permanently modified platforms.

    PubMed

    Tsalev, Dimiter L; Lampugnani, Leonardo; Georgieva, Rositsa; Chakarova, Kristina K; Petrov, Ivan I

    2002-08-23

    Some drawbacks of the phosphate modifier such as reagent blank contribution and background absorption in electrothermal atomic absorption spectrometric determination of cadmium and lead are substantially alleviated by application of small amounts of phosphate, approximately 0.2 mumol (25 mug of NH(4)H(2)PO(4) or (NH(4))(2)HPO(4)), on the integrated platform of transversely heated graphite atomizer pre-treated with 2.7 mumol of Zr (250 mug) or W (500 mug) and 0.1 mumol of Ir (20 mug). Pyrolysis temperatures for Cd and Pb are up to 900 and 1100 degrees C for aqueous solutions and within 400-600 degrees C (Cd) and 750-850 degrees C (Pb) for biological fluids (urine, blood) and tissues (hair, liver, muscle) solubilized with tetraethylammonium hydroxide. The thermally stabilized phosphate on Zr-Ir or W-Ir treated platforms serves as a permanent modifier in analyses of environmental waters by multiple hot injections of large sample aliquots. Applications to water and biological certified reference materials are tabulated and show good agreement with certified values. Characteristic masses are 0.7-1.0 pg for Cd and 26-31 pg for Pb.

  17. Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Ieggli, C. V. S.; Bohrer, D.; Noremberg, S.; do Nascimento, P. C.; de Carvalho, L. M.; Vieira, S. L.; Reis, R. N.

    2009-06-01

    An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 µg L - 1 . The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

  18. Micelle mediated extraction of magnesium from water samples with trizma-chloranilate and determination by flame atomic absorption spectrometry.

    PubMed

    Giokas, Dimosthenis L; Paleologos, Evangelos K; Veltsistas, Panayotis G; Karayannis, Miltiades I

    2002-03-04

    This article describes an analytical method for the determination of magnesium taking advantage of the cloud point phenomenon employing a suitable chelating agent (chloranilate) for Mg analysis. The method encompasses pre-concentration of the metal chelate followed by flame atomic absorption spectrometry (FAAS) analysis. The chelating agent chosen for this task is a newly synthesised salt of chloranilic acid, trizma-chloranilate, which reacts with Mg but at the same time has a very low affinity for other metallic cations like silicon, aluminium and sodium, which interfere with the determination of Mg in FAAS. The condensed surfactant phase with the metal chelate(s) is introduced into the flame of an atomic absorption spectrometer after its treatment with an acidified methanolic solution. In this way, complex and time-consuming steps for sample treatment are avoided while increased sensitivity is achieved by the presence of both methanol and surfactant in the aspirated sample. The analytical curve was rectilinear in the range of 5-220 mugl(-1) and the limit of detection was as low as 0.75 mugl(-1) with a standard deviation of 5.2%. The method was applied for the determination of Mg in natural and mineral waters with satisfactory results and recoveries in the range of 97-102%.

  19. [Determination of trace silver in water samples by solid phase extraction portable tungsten-coil electrothermal atomic absorption spectrometry].

    PubMed

    Fan, Guang-yu; Jiang, Xiao-ming; Zheng, Cheng-bin; Hou, Xian-deng; Xu, Kai-lai

    2011-07-01

    A simple method has been developed for the determination of silver in environmental water samples using solid phase extraction with tungsten-coil electrothermal atomic absorption spectrometry. Silica gel was used as an adsorbent and packed into a syringe barrel for solid phase extraction of silver prior to its determination by using a portable tungsten-coil electrothermal atomic absorption spectrometer. Optimum conditions for adsorption and desorption of silver ion, as well as interferences from co-existing ions, were investigated. A sample pH value of 6.0, a sample loading flow rate of 4.0 mL x min(-1), and the mixture of 4% (m/v) thiourea and 2% (phi) nitrate acid with the eluent flow rate of 0.5 mL x min(-1) for desorption were selected for further studies. Under optimal conditions, a linear range of 0.20-4.00 ng x mL(-1), a limit of detection (3sigma) of 0.03 ng x mL(-1) and a preconcentration factor of 94 were achieved. The proposed method was validated by testing three environmental water samples with satisfactory results.

  20. Determination of mercury in an assortment of dietary supplements using an inexpensive combustion atomic absorption spectrometry technique.

    PubMed

    Levine, Keith E; Levine, Michael A; Weber, Frank X; Hu, Ye; Perlmutter, Jason; Grohse, Peter M

    2005-01-01

    The concentrations of mercury in forty, commercially available dietary supplements, were determined using a new, inexpensive analysis technique. The method involves thermal decomposition, amalgamation, and detection of mercury by atomic absorption spectrometry with an analysis time of approximately six minutes per sample. The primary cost savings from this approach is that labor-intensive sample digestion is not required prior to analysis, further automating the analytical procedure. As a result, manufacturers and regulatory agencies concerned with monitoring lot-to-lot product quality may find this approach an attractive alternative to the more classical acid-decomposition, cold vapor atomic absorption methodology. Dietary supplement samples analyzed included astragalus, calcium, chromium picolinate, echinacea, ephedra, fish oil, ginger, ginkgo biloba, ginseng, goldenseal, guggul, senna, St John's wort, and yohimbe products. Quality control samples analyzed with the dietary supplements indicated a high level of method accuracy and precision. Ten replicate preparations of a standard reference material (NIST 1573a, tomato leaves) were analyzed, and the average mercury recovery was 109% (2.0% RSD). The method quantitation limit was 0.3 ng, which corresponded to 1.5 ng/g sample. The highest found mercury concentration (123 ng/g) was measured in a concentrated salmon oil sample. When taken as directed by an adult, this product would result in an approximate mercury ingestion of 7 mug per week.