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Sample records for source flame atomic

  1. Flame emission, atomic absorption and fluorescence spectrometry

    International Nuclear Information System (INIS)

    Horlick, G.

    1980-01-01

    Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular absorption spectrometry; electrothermal atomization atomic absorption spectroscopy; hydride generation techniques; graphite furnace atomic emission spectrometry; atomic fluorescence spectrometry; and analytical comparisons

  2. A new approach for the determination of sulphur in food samples by high-resolution continuum source flame atomic absorption spectrometer.

    Science.gov (United States)

    Ozbek, N; Baysal, A

    2015-02-01

    The new approach for the determination of sulphur in foods was developed, and the sulphur concentrations of various fresh and dried food samples determined using a high-resolution continuum source flame atomic absorption spectrometer with an air/acetylene flame. The proposed method was optimised and the validated using standard reference materials, and certified values were found to be within the 95% confidence interval. The sulphur content of foods ranged from less than the LOD to 1.5mgg(-1). The method is accurate, fast, simple and sensitive. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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)…

  4. Optimization of Flame Atomic Absorption Spectrometry for ...

    African Journals Online (AJOL)

    Optimization of Flame Atomic Absorption Spectrometry for Measurement of High Concentrations of Arsenic and Selenium. ... This procedure allowed a rapid determination of As from minimum 4.462 mg/L to higher concentrations without sample pretreatment. Besides As, this method successfully measured Se concentrations ...

  5. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    International Nuclear Information System (INIS)

    Marschner, Karel; Musil, Stanislav; Dědina, Jiří

    2015-01-01

    A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH 4 in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l −1 and 1.0 ng l −1 , respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l −1

  6. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Marschner, Karel, E-mail: karel.marschner@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Albertov 8, 128 43 Prague (Czech Republic); Musil, Stanislav; Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

    2015-07-01

    A detailed optimization of relevant experimental parameters of two hydride atomizers for atomic fluorescence spectrometry: flame-in-gas-shield atomizer with a two-channel shielding unit and a standard atomizer for atomic fluorescence spectrometry, miniature diffusion flame, was performed. Arsine, generated by the reaction with NaBH{sub 4} in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l{sup −1} and 1.0 ng l{sup −1}, respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l{sup −1}.

  7. Use of slurry sampling for the direct determination of zinc in yogurt by high resolution-continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Brandao, Geovani C; de Jesus, Raildo M; da Silva, Erik G P; Ferreira, Sergio L C

    2010-06-15

    This paper presents an analytical procedure for the direct determination of zinc in yogurt employing sampling slurry and high resolution-continuum source flame atomic absorption spectrometry (HR-CS FAAS). The step optimization established the experimental conditions of: 2.0molL(-1) hydrochloric acid, a sonication time of 20min and a sample mass of 1.0g for a slurry volume of 25mL. This method allows the determination of zinc with a limit of quantification of 0.32microgg(-1). The precision expressed as relative standard deviation (RSD) were 0.82 and 2.08% for yogurt samples containing zinc concentrations of 4.85 and 2.49microgg(-1), respectively. The accuracy was confirmed by the analysis of a certified reference material of non-fat milk powder furnished by the National Institute of Standard and Technology. The proposed method was applied for the determination of zinc in seven yogurt samples. The zinc content was varied from 2.19 to 4.85microgg(-1). These results agreed with those reported in the literature. The samples were also analyzed after acid digestion and zinc determination by FAAS. No statistical difference was observed between the results obtained by both of the procedures performed.

  8. Fast sequential multi-element determination of major and minor elements in environmental samples and drinking waters by high-resolution continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Ma Jesús; Sevilla, Ma Teresa; Procopio, Jesús R

    2015-01-07

    The fast sequential multi-element determination of 11 elements present at different concentration levels in environmental samples and drinking waters has been investigated using high-resolution continuum source flame atomic absorption spectrometry. The main lines for Cu (324.754 nm), Zn (213.857 nm), Cd (228.802 nm), Ni (232.003 nm) and Pb (217.001 nm), main and secondary absorption lines for Mn (279.482 and 279.827 nm), Fe (248.327, 248.514 and 302.064 nm) and Ca (422.673 and 239.856 nm), secondary lines with different sensitivities for Na (589.592 and 330.237 nm) and K (769.897 and 404.414 nm) and a secondary line for Mg (202.582 nm) have been chosen to perform the analysis. A flow injection system has been used for sample introduction so sample consumption has been reduced up to less than 1 mL per element, measured in triplicate. Furthermore, the use of multiplets for Fe and the side pixel registration approach for Mg have been studied in order to reduce sensitivity and extend the linear working range. The figures of merit have been calculated and the proposed method was applied to determine these elements in a pine needles reference material (SRM 1575a), drinking and natural waters and soil extracts. Recoveries of analytes added at different concentration levels to water samples and extracts of soils were within 88-115% interval. In this way, the fast sequential multi-element determination of major and minor elements can be carried out, in triplicate, with successful results without requiring additional dilutions of samples or several different strategies for sample preparation using about 8-9 mL of sample. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Validation of an analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals in soil.

    Science.gov (United States)

    Frentiu, Tiberiu; Ponta, Michaela; Hategan, Raluca

    2013-03-01

    The aim of this paper was the validation of a new analytical method based on the high-resolution continuum source flame atomic absorption spectrometry for the fast-sequential determination of several hazardous/priority hazardous metals (Ag, Cd, Co, Cr, Cu, Ni, Pb and Zn) in soil after microwave assisted digestion in aqua regia. Determinations were performed on the ContrAA 300 (Analytik Jena) air-acetylene flame spectrometer equipped with xenon short-arc lamp as a continuum radiation source for all elements, double monochromator consisting of a prism pre-monocromator and an echelle grating monochromator, and charge coupled device as detector. For validation a method-performance study was conducted involving the establishment of the analytical performance of the new method (limits of detection and quantification, precision and accuracy). Moreover, the Bland and Altman statistical method was used in analyzing the agreement between the proposed assay and inductively coupled plasma optical emission spectrometry as standardized method for the multielemental determination in soil. The limits of detection in soil sample (3σ criterion) in the high-resolution continuum source flame atomic absorption spectrometry method were (mg/kg): 0.18 (Ag), 0.14 (Cd), 0.36 (Co), 0.25 (Cr), 0.09 (Cu), 1.0 (Ni), 1.4 (Pb) and 0.18 (Zn), close to those in inductively coupled plasma optical emission spectrometry: 0.12 (Ag), 0.05 (Cd), 0.15 (Co), 1.4 (Cr), 0.15 (Cu), 2.5 (Ni), 2.5 (Pb) and 0.04 (Zn). Accuracy was checked by analyzing 4 certified reference materials and a good agreement for 95% confidence interval was found in both methods, with recoveries in the range of 94-106% in atomic absorption and 97-103% in optical emission. Repeatability found by analyzing real soil samples was in the range 1.6-5.2% in atomic absorption, similar with that of 1.9-6.1% in optical emission spectrometry. The Bland and Altman method showed no statistical significant difference between the two spectrometric

  10. Detection of atomic oxygen in flames by absorption spectroscopy

    International Nuclear Information System (INIS)

    Cheskis, S.; Kovalenko, S.A.

    1994-01-01

    The absolute concentration of atomic oxygen in an atmospheric pressure hydrogen/air flame has been measured using Intracavity Laser Spectroscopy (ICLS) based on a dye laser pumped by an argon-ion laser. Absorptions at the highly forbidden transitions at 630.030 nm and 636.380 nm were observed at an equivalent optical length of up to 10 km. The relatively low intensity of the dye laser avoids photochemical interferences that are inherent to some other methods for detecting atomic oxygen. The detection sensitivity is about 6x10 14 atom/cm 3 and can be improved with better flame and laser stabilization. (orig.)

  11. Theory of analytical curves in atomic fluorescence flame spectrometry

    NARCIS (Netherlands)

    Hooymayers, H.P.

    An explicit expression for the intensity of atomic resonance fluorescence as a function of atomic concentration in a flame is derived under certain idealized conditions. The expression is generally valid for a pure Doppler absorption line profile as well as for a combined Doppler and collisional

  12. Method development for the determination of fluorine in toothpaste via molecular absorption of aluminum mono fluoride using a high-resolution continuum source nitrous oxide/acetylene flame atomic absorption spectrophotometer.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2012-05-30

    Fluorine was determined via the rotational molecular absorption line of aluminum mono fluoride (AlF) generated in C(2)H(2)/N(2)O flame at 227.4613 nm using a high-resolution continuum source flame atomic absorption spectrophotometer (HR-CS-FAAS). The effects of AlF wavelength, burner height, fuel rate (C(2)H(2)/N(2)O) and amount of Al on the accuracy, precision and sensitivity were investigated and optimized. The Al-F absorption band at 227.4613 nm was found to be the most suitable analytical line with respect to sensitivity and spectral interferences. Maximum sensitivity and a good linearity were obtained in acetylene-nitrous oxide flame at a flow rate of 210 L h(-1) and a burner height of 8mm using 3000 mg L(-1) of Al for 10-1000 mg L(-1)of F. The accuracy and precision of the method were tested by analyzing spiked samples and waste water certified reference material. The results were in good agreement with the certified and spiked amounts as well as the precision of several days during this study was satisfactory (RSD<10%). The limit of detection and characteristic concentration of the method were 5.5 mg L(-1) and 72.8 mg L(-1), respectively. Finally, the fluorine concentrations in several toothpaste samples were determined. The results found and given by the producers were not significantly different. The method was simple, fast, accurate and sensitive. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Solid-phase extraction and separation procedure for trace aluminum in water samples and its determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

    Science.gov (United States)

    Ciftci, Harun; Er, Cigdem

    2013-03-01

    In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L(-1) HNO(3) and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L(-1) and 3.91 μg L(-1), respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples.

  14. Atomic spectrometry based on metallic tube atomizers heated by flame: Innovative strategies from fundamentals to analysis

    International Nuclear Information System (INIS)

    Arruda, Marco Aurelio Zezzi; Figueiredo, Eduardo Costa

    2009-01-01

    This review describes recent developments in atomic absorption spectrometry using metallic tube atomizers heated by flames. Sample introduction in spray or gaseous form is emphasized, describing some proposed systems for this task and the fundamentals involved in each context. The latest challenges and future possibilities for use of metallic tubes in atomic/mass spectrometry are also considered.

  15. Stable atomic hydrogen: Polarized atomic beam source

    International Nuclear Information System (INIS)

    Niinikoski, T.O.; Penttilae, S.; Rieubland, J.M.; Rijllart, A.

    1984-01-01

    We have carried out experiments with stable atomic hydrogen with a view to possible applications in polarized targets or polarized atomic beam sources. Recent results from the stabilization apparatus are described. The first stable atomic hydrogen beam source based on the microwave extraction method (which is being tested ) is presented. The effect of the stabilized hydrogen gas density on the properties of the source is discussed. (orig.)

  16. Methane Formation by Flame-Generated Hydrogen Atoms in the Flame Ionization Detector

    DEFF Research Database (Denmark)

    Holm, Torkil; Madsen, Jørgen Øgaard

    1996-01-01

    , and conceivably all hydrocarbons are quantitatively converted into methane at temperatures below 600 C, that is, before the proper combustion has started. The splitting of the C-C bonds is preceded by hydrogenation of double and triple bonds and aromatic rings. The reactions, no doubt, are caused by hydrogen...... atoms, which are formed in the burning hydrogen and which diffuse into the inner core of the flame. The quantitative formation of methane appears to explain the "equal per carbon" rule for the detector response of hydrocarbons, since all carbons are "exchanged" for methane molecules....

  17. High speed atom source

    International Nuclear Information System (INIS)

    Hoshino, Hitoshi.

    1990-01-01

    In a high speed atom source, since the speed is not identical between ions and electrons, no sufficient neutralizing effect for ionic rays due to the mixing of the ionic rays and the electron rays can be obtained failing to obtain high speed atomic rays at high density. In view of the above, a speed control means is disposed for equalizing the speed of ions forming ionic rays and the speed of electrons forming electron rays. Further, incident angle of the electron rays and/or ionic rays to a magnet or an electrode is made variable. As a result, the relative speed between the ions and the electrons to the processing direction is reduced to zero, in which the probability of association between the ions and the electrons due to the coulomb force is increased to improve the neutralizing efficiency to easily obtain fine and high density high speed electron rays. Further, by varying the incident angle, a track capable of obtaining an ideal mixing depending on the energy of the neutralized ionic rays is formed. Since the high speed electron rays has such high density, they can be irradiated easily to the minute region of the specimen. (N.H.)

  18. Development of the Flame Test Concept Inventory: Measuring Student Thinking about Atomic Emission

    Science.gov (United States)

    Bretz, Stacey Lowery; Murata Mayo, Ana Vasquez

    2018-01-01

    This study reports the development of a 19-item Flame Test Concept Inventory, an assessment tool to measure students' understanding of atomic emission. Fifty-two students enrolled in secondary and postsecondary chemistry courses were interviewed about atomic emission and explicitly asked to explain flame test demonstrations and energy level…

  19. Extraction method based on emulsion breaking for the determination of Cu, Fe and Pb in Brazilian automotive gasoline samples by high-resolution continuum source flame atomic absorption spectrometry

    Science.gov (United States)

    Leite, Clarice C.; de Jesus, Alexandre; Kolling, Leandro; Ferrão, Marco F.; Samios, Dimitrios; Silva, Márcia M.

    2018-04-01

    This work reports a new method for extraction of Cu, Fe and Pb from Brazilian automotive gasoline and their determination by high-resolution continuous source flame atomic absorption spectrometry (HR-CS FAAS). The method was based on the formation of water-in-oil emulsion by mixing 2.0 mL of extraction solution constituted by 12% (w/v) Triton X-100 and 5% (v/v) HNO3 with 10 mL of sample. After heating at 90 °C for 10 min, two well-defined phases were formed. The bottom phase (approximately 3.5 mL), composed of acidified water and part of the ethanol originally present in the gasoline sample, containing the extracted analytes was analyzed. The surfactant and HNO3 concentrations and the heating temperature employed in the process were optimized by Doehlert design, using a Brazilian gasoline sample spiked with Cu, Fe and Pb (organometallic compounds). The efficiency of extraction was investigated and it ranged from 80 to 89%. The calibration was accomplished by using matrix matching method. For this, the standards were obtained performing the same extraction procedure used for the sample, using emulsions obtained with a gasoline sample free of analytes and the addition of inorganic standards. Limits of detection obtained were 3.0, 5.0 and 14.0 μg L-1 for Cu, Fe and Pb, respectively. These limits were estimated for the original sample taking into account the preconcentration factor obtained. The accuracy of the proposed method was assured by recovery tests spiking the samples with organometallic standards and the obtained values ranged from 98 to 105%. Ten gasoline samples were analyzed and Fe was found in four samples (0.04-0.35 mg L-1) while Cu (0.28 mg L-1) and Pb (0.60 mg L-1) was found in just one sample.

  20. Derivative flame atomic absorption spectrometry and its application in trace analysis

    International Nuclear Information System (INIS)

    Sun, H. W.; Li, L. Q.

    2005-01-01

    Flame atomic absorption spectrometry is an accepted and widely used method for the determination of trace elements in a great variety of samples. But its sensitivity doesn't meet the demands of trace and ultra-trace analysis for some samples. The derivative signal processing technique, with a very high capability for enhancing sensitivity, was developed for flame atomic absorption spectrometry. The signal models of conventional flame atomic absorption spectrometry are described. The equations of derivative signals are established for flame atomic absorption spectrometry, flow injection atomic absorption spectrometry (FI-FAAS) and atom trapping flame atomic absorption spectrometry (AT-FAAS). The principle and performance of the derivative atomic absorption spectrometry are evaluated. The derivative technique based on determination of variation rate of signal intensity with time (dl/dt) is different from the derivative spectrophotometry based on determination of variation rate of signal intensity with wavelength (dl/dhλ). Derivative flame atomic absorption spectrometry has higher sensitivity, lower detection limits and better accuracy. It has been applied to the direct determination of trace elements without preconcentration. If the derivative technique was combined with several preconcentration techniques, the sensitivity would be enhanced further for ultra-trace analysis with good linearity. The applications of derivative flame atomic absorption spectroscopy are reviewed for trace element analysis in biological, pharmaceutical, environmental and food samples

  1. Lithium determination in whole blood by flame atomic emission spectrometry

    International Nuclear Information System (INIS)

    Rahman, S.; Khalid, N.; Nasimullah; Iqbal, M.Z.

    2003-01-01

    A simple and rapid method for the determination of lithium in whole blood using Flame atomic emission spectrometry is described. No sample preparation was required apart from dilution with 0.02 N HNO/sub 3/. The reliability of the method was determined by analyzing Standard Reference Material (SRM) under identical experimental conditions and comparing the determined lithium concentration with the reported value. These were in good agreement with each other. The determined range of lithium in the whole blood of fifty-six healthy adult volunteers (28 males and 28 females) were 13.1 - 47.8 mg L-1. The determined average concentration of lithium in whole blood was compared with the reported values of other countries. The data was statistically analyzed with respect to sex and different age groups. (author)

  2. Flame emission spectrometry using atomic absorption apparatus. I. Determination of Sr in sea water

    International Nuclear Information System (INIS)

    Aizawa, S.; Yoshimura, E.; Hamachi, M.; Haraguchi, H.; Dokiya, Y.; Fuwa, K.

    1976-01-01

    Flame emission determination of Sr in seawater was studied using an ordinary atomic absorption apparatus. The analytical line 4607 A was used with a background correction at 4616 A. The ionization was negligible in an air acetylene flame with seawater, and the interference of H 2 SO 4 was eliminated using the higher part of the flame. Sr concentration of seawater of Tokyo Bay and Sagami Bay has been determined

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

    Science.gov (United States)

    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)

  4. Influence of atomization quality modulation on flame dynamics in a hypergolic rocket engine

    Directory of Open Access Journals (Sweden)

    Moritz Schulze

    2016-09-01

    Full Text Available For the numerical evaluation of the thermoacoustic stability of rocket engines often hybrid methods are applied, which separate the computation of wave propagation in the combustor from the analysis of the flame response to acoustic perturbations. Closure requires a thermoacoustic feedback model which provides the heat release fluctuation in the source term of the employed wave transport equations. The influence of the acoustic fluctuations in the combustion chamber on the heat release fluctuations from the modulation of the atomization of the propellants in a hypergolic upper stage rocket engine is studied. Numerical modeling of a single injector provides the time mean reacting flow field. A network of transfer functions representing all aspects relevant for the feedback model is presented. Analytical models for the injector admittances and for the atomization transfer functions are provided. The dynamics of evaporation and combustion are studied numerically and the numerical results are analyzed. An analytical approximation of the computed flame transfer function is combined with the analytical models for the injector and the atomization quality to derive the feedback model for the wave propagation code. The evaluation of this model on the basis of the Rayleigh index reveals the thermoacoustic driving potential originating from the fluctuating spray quality.

  5. High efficiency atomic hydrogen source

    International Nuclear Information System (INIS)

    Lagomarsino, V.; Bassi, D.; Bertok, E.; De Paz, M.; Tommasini, F.

    1974-01-01

    This work presents preliminary results of research intended to produce a M.W. discharge atomic hydrogen source with good dissociation at pressures larger than 10 torr. Analysis of the recombination process at these pressures shows that the volume recombination by three body collisions may be more important than wall recombination or loss of atoms by diffusion and flow outside the discharge region

  6. Quantitative determination of impurities in nuclear grade aluminum by Flame-Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Jat, J.R.; Nayak, A.K.; Balaji Rao, Y.; Ravindra, H.R.

    2013-01-01

    The paper deals with quantitative determination of impurity elements in nuclear grade aluminum, used as fin tubes in research reactors, by Flame-Atomic Absorption Spectrometry (F-AAS). The results have been compared with those obtained by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) method. Experimental conditions used in both the methods are given in the paper. (author)

  7. Flame experiments at the advanced light source: new insights into soot formation processes.

    Science.gov (United States)

    Hansen, Nils; Skeen, Scott A; Michelsen, Hope A; Wilson, Kevin R; Kohse-Höinghaus, Katharina

    2014-05-26

    The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory(1-4). This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range(5,6). The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species' profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C3H3, C3H5, and i-C4H5, are identified as important intermediates(7). The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles(4). The experimental results indicate that the widely accepted H-abstraction-C2H2-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation

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

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    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{sub 2}Te 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 arrangernents (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{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration 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 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.

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

    Science.gov (United States)

    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…

  10. Impurities determination of uranium metal flame spectrophotometry and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Rukihati.

    1978-01-01

    The atomic absorption flame spectrophotometry has been applied to the determination of chromium, copper, iron, lead, manganese and nickel in the metal of uranium. The first step to be done is to dissolve the uranium sample in nitric acid and then the uranium is extracted by a tributylphosphate-carbon tetrachloride solution. The aqueous phase which contains the chromium, copper, iron, lead, manganese and nickel is aspirated into an airacetylene flame. The results of this method are compared with the results of emission spectrographic method. It is found that this technique is competative to other methods in the sense that it is quite fast and accurate. (author)

  11. Short wavelength sources and atoms and ions

    International Nuclear Information System (INIS)

    Kennedy, E.T.

    2008-01-01

    The interaction of ionizing radiation with atoms and ions is a key fundamental process. Experimental progress has depended in particular on the development of short wavelength light sources. Laser-plasma and synchrotron sources have been exploited for several decades and most recently the development of short wavelength Free Electron Laser (FEL) sources is revolutionizing the field. This paper introduces laser plasma and synchrotron sources through examples of their use in studies of the interaction of ionizing radiation with atoms and ions, ranging from few-electron atomic and ionic systems to the many-electron high atomic number actinides. The new FEL source (FLASH) at DESY is introduced. (author)

  12. Determination of calcium in Mashhad city tap water by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mashhadian, N.V.

    2012-01-01

    Summary: Calcium in drinking water is one of the sources of calcium that may contribute significantly to the daily calcium intake. In this study, the samples of tap water were randomly taken from five zones of Mashhad city. Calcium concentration was determined by flame atomic absorption spectrometry (FAAS) technique. The precision of the method was evaluated. The CV% of 6 replicate determinations at 5 macro g/ml Ca was 4.2 in one day and 4.5, among 6 consecutive days. The recovery of spiked samples (98.7%) also showed that the proposed method is reliable for the determination of amounts of calcium in water samples. The mean of calcium in tap water in the city of Mashhad was 52.61+-12.91 (SD) macro g/ml. At present, the amount of calcium in Mashhad tap waters is within the national standard. However, due to the climate and environmental changes, determination of calcium in tap water of Mashhad in different seasons is recommended. (author)

  13. New sources of cold atoms for atomic clocks

    International Nuclear Information System (INIS)

    Aucouturier, E.

    1997-01-01

    The purpose of this doctoral work is the realisation of new sources of cold cesium atoms that could be useful for the conception of a compact and high-performance atomic clock. It is based on experiences of atomic physics using light induced atomic manipulation. We present here the experiences of radiative cooling of atoms that have been realised at the Laboratoire de l'Horloge Atomique from 1993 to 1996. Firstly, we applied the techniques of radiative cooling and trapping of atoms in order to create a three-dimensional magneto-optical trap. For this first experience, we developed high quality laser sources, that were used for other experiments. We imagined a new configuration of trapping (two-dimensional magneto-optical trap) that was the basis for a cold atom source. This design gives the atoms a possibility to escape towards one particular direction. Then, we have extracted the atoms from this anisotropic trap in order to create a continuous beam of cold atoms. We have applied three methods of extraction. Firstly, the launching of atoms was performed by reducing the intensity of one of the cooling laser beams in the desired launching direction. Secondly, a frequency detuning between the two laser laser beams produced the launching of atoms by a so-called 'moving molasses'. The third method consisted in applying a static magnetic field that induced the launching of atoms in the direction of this magnetic field. At the same time, another research on cold atoms was initiated at the I.H.A. It consisted in cooling a large volume of atoms from a cell, using an isotropic light. This offers an interesting alternative to the traditional optical molasses. (author)

  14. Determination of five trace elements in leaves in Nanfang sweet orange by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Li Fangqing

    2006-01-01

    The five trace elements of copper, zinc, manganese, iron and cobalt in leaves of Nanfang sweet orange are determined by flame atomic absorption spectrometry. The technique is simple, precise and sensitive. The effect of the type of digesting solution (mixed acid), the ratio of mixed acid, the volume of digesting solution and the time of digesting are investigated in details. The results show that leaves of Nanfang sweet orange contain higher amount of iron and zinc. (authors)

  15. On-line Incorporation of Cloud Point Extraction in Flame Atomic Absorption Spectrometric Determination of Silver

    OpenAIRE

    DALALI, Nasser; JAVADI, Nasrin; AGRAWAL, Yadvendra KUMAR

    2008-01-01

    A cloud point extraction method was incorporated into a flow injection system, coupled with flame atomic absorption spectrometry, for determination of trace amounts of silver. The analyte in the aqueous solution was acidified with 0.2 mol L-1 sulfuric acid and complexed with dithizone. The cloud point extraction was performed using the non-ionic surfactant Triton X-114. After obtaining the cloud point, the surfactant-rich phase containing the dithizonate complex was collected in a m...

  16. Computer programs in BASIC language for atomic absorption flame spectroscopy. Part 2. Documentation

    International Nuclear Information System (INIS)

    Boyle, W.G. Jr.

    1977-01-01

    There are three computer programs, written in the BASIC language, used for taking data from an atomic absorption spectrophotometer operating in the flame mode. The programs are divided into logical sections, and these have been flow-charted. The general features, the structure, the order of subroutines and functions, and the storage of data are discussed. In addition, variables are listed and defined, and a complete listing of each program with a symbol occurrence table is provided

  17. Computer programs in BASIC language for atomic absorption flame spectroscopy. Part 1. Operating instructions

    International Nuclear Information System (INIS)

    Boyle, W.G. Jr.

    1977-01-01

    These instructions describe how to use three BASIC language programs to process data from atomic absorption spectrophotometers operated in the flame mode. These programs will also control an automatic sampler if desired. The instructions cover loading the programs, responding to computer prompts, choosing among various options for processing the data, operating the automatic sampler, and producing reports. How the programs differ is also explained. Examples of computer/operator dialogue are presented for typical cases

  18. Flame-in-gas-shield and miniature diffusion flame hydride atomizers for atomic fluorescence spectrometry: optimization and comparison

    Czech Academy of Sciences Publication Activity Database

    Marschner, Karel; Musil, Stanislav; Dědina, Jiří

    2015-01-01

    Roč. 109, JUL (2015), s. 16-23 ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : hydride generation * arsenic * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015

  19. In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies

    International Nuclear Information System (INIS)

    Kılınç, Ersin; Bakırdere, Sezgin; Aydın, Fırat; Ataman, O. Yavuz

    2013-01-01

    Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FAAS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 μg mL −1 and 0.51 ng mL −1 , respectively. Linear calibration plot was obtained in the range of 2.5–25.0 ng mL −1 for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e. - Highlights: • Further increasing in sensitivity of SQT-AT-FAAS was obtained by using a W coated SQT. • 613 fold sensitivity enhancement was achieved by W coated SQT-AT-FAAS versus FAAS. • A sensitive, rapid and simple technique for Bi was developed with an LOD of 0.51 ng mL −1 . • The technique is suggested for laboratories equipped with only a flame AA spectrometer

  20. Flame and flameless atomic-absorption determination of tellurium in geological materials

    Science.gov (United States)

    Chao, T.T.; Sanzolone, R.F.; Hubert, A.E.

    1978-01-01

    The sample is digested with a solution of hydrobromic acid and bromine and the excess of bromine is expelled. After dilution of the solution to approximately 3 M in hydrobromic acid, ascorbic acid is added to reduce iron(III) before extraction of tellurium into methyl isobutyl ketone (MIBK). An oxidizing air-acetylene flame is used to determine tellurium in the 0.1-20 ppm range. For samples containing 4-200 ppb of tellurium, a carbon-rod atomizer is used after the MIBK extract has been washed with 0.5 M hydrobromic acid to remove the residual iron. The flame procedure is useful for rapid preliminary monitoring, and the flameless procedure can determine tellurium at very low concentrations. ?? 1978.

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

    Science.gov (United States)

    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.

  2. Optical measurements of atomic oxygen concentration, temperature and nitric oxide production rate in flames

    Science.gov (United States)

    Myhr, Franklin Henry

    An optical method for measuring nitric oxide (NO) production rates in flames was developed and characterized in a series of steady, one-dimensional, atmospheric-pressure laminar flames of 0.700 Hsb2/0.199 Nsb2/0.101 COsb2 or 0.700 CHsb4/0.300 Nsb2 (by moles) with dry air, with equivalence ratios from 0.79 to 1.27. Oxygen atom concentration, (O), was measured by two-photon laser-induced fluorescence (LIF), temperature was measured by ultraviolet Rayleigh scattering, and nitrogen concentration was calculated from supplied reactant flows; together this information was used to calculate the NO production rate through the thermal (Zel'dovich) mechanism. Measurements by two other techniques were compared with results from the above method. In the first comparison, gas sampling was used to measure axial NO concentration profiles, the slopes of which were multiplied by velocity to obtain total NO production rates. In the second comparison, LIF measurements of hydroxyl radical (OH) were used with equilibrium water concentrations and a partial equilibrium assumption to find (O). Nitric oxide production rates from all three methods agreed reasonably well. Photolytic interference was observed during (O) LIF measurements in all of the flames; this is the major difficulty in applying the optical technique. Photolysis of molecular oxygen in lean flames has been well documented before, but the degree of interference observed in the rich flames suggests that some other molecule is also dissociating; the candidates are OH, CO, COsb2 and Hsb2O. An extrapolative technique for removing the effects of photolysis from (O) LIF measurements worked well in all flames where NO production was significant. Using the optical method to measure NO production rates in turbulent flames will involve a tradeoff among spatial resolution, systematic photolysis error, and random shot noise. With the conventional laser system used in this work, a single pulse with a resolution of 700 mum measured NO

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

    Science.gov (United States)

    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…

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

    Science.gov (United States)

    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.

  5. Combination of solid phase extraction and flame atomic absorption spectrometry for trace analysis of cadmium

    OpenAIRE

    Ensafi, Ali A.; Shiraz, Ameneh Zendegi

    2008-01-01

    A new selective method was developed for the separation and preconcentration of Cd(II) ions based on its complex formation with Xylenol orange loaded on activated carbon as a solid support in a mini-column. The preconcentrated ions were eluted by passing 5.0 mL 0.5 mol L-1 HNO3 solution through the solid support and then the Cd(II) contents was measured by flame atomic absorption spectrometry. Conditions for preparation of the modified activated carbon, pH and flow variables were studied, as ...

  6. Combustion flame-plasma hybrid reactor systems, and chemical reactant sources

    Science.gov (United States)

    Kong, Peter C

    2013-11-26

    Combustion flame-plasma hybrid reactor systems, chemical reactant sources, and related methods are disclosed. In one embodiment, a combustion flame-plasma hybrid reactor system comprising a reaction chamber, a combustion torch positioned to direct a flame into the reaction chamber, and one or more reactant feed assemblies configured to electrically energize at least one electrically conductive solid reactant structure to form a plasma and feed each electrically conductive solid reactant structure into the plasma to form at least one product is disclosed. In an additional embodiment, a chemical reactant source for a combustion flame-plasma hybrid reactor comprising an elongated electrically conductive reactant structure consisting essentially of at least one chemical reactant is disclosed. In further embodiments, methods of forming a chemical reactant source and methods of chemically converting at least one reactant into at least one product are disclosed.

  7. A cold atom electron source

    NARCIS (Netherlands)

    Taban, G.

    2009-01-01

    Pulsed bright electron sources offer the possibility to study the structure of matter in great spatial and temporal detail. An example of an indirect method is to generate hard X-ray °ashes with high brilliance, a new Free Electron Laser facility is under construction. It requires an electron source

  8. In situ atom trapping of Bi on W-coated slotted quartz tube flame atomic absorption spectrometry and interference studies

    Energy Technology Data Exchange (ETDEWEB)

    Kılınç, Ersin, E-mail: kilincersin@gmail.com [Medical Laboratory Techniques, Vocational Higher School of Healthcare Studies, Mardin Artuklu University, 47200 Mardin (Turkey); Bakırdere, Sezgin [Yıldız Technical University, Art and Science Faculy, Department of Chemistry, Esenler, TR 34220 İstanbul (Turkey); Aydın, Fırat [Dicle University, Faculty of Science, Department of Chemistry, Laboratory of Chemical Analysis, TR 21280 Diyarbakır (Turkey); Ataman, O. Yavuz [Middle East Technical University, Faculty of Arts and Sciences, Department of Chemistry, 06800 Ankara (Turkey)

    2013-11-01

    Analytical performances of metal coated slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) and slotted quartz tube in situ atom trapping flame atomic absorption spectrometry (SQT-AT-FAAS) systems were evaluated for determination of Bi. Non-volatile elements such as Mo, Zr, W and Ta were tried as coating materials. It was observed that W-coated SQT gave the best sensitivity for the determination of Bi for SQT-FAAS and SQT-AT-FAAS. The parameters for W-coated SQT-FAAS and W-coated SQT-AT-FAAS were optimized. Sensitivity of FAAS for Bi was improved as 4.0 fold by W-coated SQT-FAAS while 613 fold enhancement in sensitivity was achieved by W-coated SQT-AT-FAAS using 5.0 min trapping with respect to conventional FAAS. MIBK was selected as organic solvent for the re-atomization of Bi from the trapping surface. Limit of detection values for W-coated SQT-FAAS and W-coated SQT-AT-FAAS was obtained as 0.14 μg mL{sup −1} and 0.51 ng mL{sup −1}, respectively. Linear calibration plot was obtained in the range of 2.5–25.0 ng mL{sup −1} for W-coated SQT-AT-FAAS. Accuracy of the W-coated SQT-AT-FAAS system was checked by analyzing a standard reference material, NIST 1643e. - Highlights: • Further increasing in sensitivity of SQT-AT-FAAS was obtained by using a W coated SQT. • 613 fold sensitivity enhancement was achieved by W coated SQT-AT-FAAS versus FAAS. • A sensitive, rapid and simple technique for Bi was developed with an LOD of 0.51 ng mL{sup −1}. • The technique is suggested for laboratories equipped with only a flame AA spectrometer.

  9. Indirect determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame

    International Nuclear Information System (INIS)

    Alder, J.F.; Das, B.C.

    1977-01-01

    An indirect method has been developed for the determination of uranium by atomic-absorption spectrophotometry using an air-acetylene flame. Use is made of the reduction of copper(II) by uranium(IV) followed by complex formation of the copper(I) ions so produced with neocuproine (2,9-dimethyl-1,10-phenanthroline) and finally the determination of copper in this complex by atomic-absorption spectrophotometry. The results show that the method can be recommended, provided that care is taken to ensure the complete reduction of uranium(VI) to uranium(IV). The sensitivity of the method is 4.9 μg of uranium and the upper limit 500 μg without dilution. (author)

  10. Study of new technique of solid combustible materials to determination of volatile elements by flame atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Campos, R.C. de.

    1988-01-01

    A new technique for direct trace element analysis of solid combustible materials is described. The samples (up to 10 mg) are weighed on a graphite platform wich is then placed in a quartz tube, at the focal point of three infrared lamps. When the lamps are turned on, the sample burns in a stream of air, and the resulting dry aerosol containing volatile elements such as Hg, Cd, Bi, Tl, Zn, Pb and Cu is carried into the mixing chamber and thence into the flame, where the atomic absorption measurement is carried out. This technique overcomes chemical sample preparation steps, avoiding contaminations of losses associated with these steps. A ''furnace in flame'' system where the aerosol is transported to a flame heated T-tube is also described. The influence of flame stoichiometry, observation height, platform material and air flux intensity was studied inorder to determine optimal analytical conditions. (author) [pt

  11. Organic solvents as interferents in arsenic determination by hydride generation atomic absorption spectrometry with flame atomization

    Czech Academy of Sciences Publication Activity Database

    Karadjova, I.B.; Lampugnani, L.; Dědina, Jiří; D'Ulivo, A.; Onor, M.; Tsalev, D.L.

    2006-01-01

    Roč. 61, č. 5 (2006), s. 525-531 ISSN 0584-8547 R&D Projects: GA AV ČR IAA400310507 Institutional research plan: CEZ:AV0Z40310501 Keywords : hydride generation * atomic absorption spectrometry * interferences Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.092, year: 2006

  12. Matrix effects on the determination of manganese in geological materials by atomic-absorption spectrophotometry under different flame conditions

    Science.gov (United States)

    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.

  13. Manganese dioxide causes spurious gold values in flame atomic-absorption readings from HBr-Br2 digestions

    Science.gov (United States)

    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.

  14. On-line determination of manganese in solid seafood samples by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yebra, M.C.; Moreno-Cid, A.

    2003-01-01

    Manganese is extracted on-line from solid seafood samples by a simple continuous ultrasound-assisted extraction system (CUES). This system is connected to an on-line manifold, which permits the flow-injection flame atomic absorption spectrometric determination of manganese. Optimisation of the continuous leaching procedure is performed by an experimental design. The proposed method allows the determination of manganese with a relative standard deviation of 0.9% for a sample containing 23.4 μg g -1 manganese (dry mass). The detection limit is 0.4 μg g -1 (dry mass) for 30 mg of sample and the sample throughput is ca. 60 samples per hour. Accurate results are obtained by measuring TORT-1 certified reference material. The procedure is finally applied to mussel, tuna, sardine and clams samples

  15. The coupling of rapidly synergistic cloud point extraction with thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Wen, X.; Deng, Q.; Guo, J.; Zhao, X.; Zhao, Y.; Ji, S.

    2012-01-01

    Rapidly synergistic cloud point extraction (RS-CPE) was coupled with thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) to result in new CPE patterns and accelerated (1 min) protocols. It is demonstrated, for the case of copper (II) ion, that TS-FF-AAS improves the sampling efficiency and the sensitivity of FAAS determinations. Problems of nebulization associated with previous methods based on the coupling of FAAS and RS-CPE are overcome. TS-FF-AAS also improves sensitivity and gives a limit of detection for copper of 0.20 μg L -1 , which is better by a factor of 32. Compared to direct FAAS, the factor is 114. (author)

  16. Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS)

    International Nuclear Information System (INIS)

    Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R.

    2014-01-01

    Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L -1 were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

  17. Speciation analysis of arsenic by selective hydride generation- cryotrapping-atomic fluorescence spectrometry with flame-in-gas- shield atomizer: Achieving extremely low detection limits with inexpensive instrumentation

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš; Currier, J. M.; Stýblo, M.; Dědina, Jiří

    2014-01-01

    Roč. 86, č. 20 (2014), s. 10422-10428 ISSN 0003-2700 R&D Projects: GA ČR GA14-23532S; GA MŠk LH12040 Institutional support: RVO:68081715 Keywords : speciation analysis of arsenic * selective hydride generation * flame-in-gas-shield atomizer * cryotrapping-atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014

  18. Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

    Science.gov (United States)

    Kowalewska, Zofia

    2011-07-01

    For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the ∆ν = 0 vibrational sequence within the electronic transition X 1∑ + → A 1П, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd xS y molecules. At the 258.056 nm line, with the wavelength range covering central pixel ± 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg -1 in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg -1 in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with sulphur content determined by X-ray fluorescence

  19. Feasibility of high-resolution continuum source molecular absorption spectrometry in flame and furnace for sulphur determination in petroleum products

    Energy Technology Data Exchange (ETDEWEB)

    Kowalewska, Zofia, E-mail: zofia.kowalewska@obr.pl

    2011-07-15

    For the first time, high-resolution molecular absorption spectrometry with a high-intensity xenon lamp as radiation source has been applied for the determination of sulphur in crude oil and petroleum products. The samples were analysed as xylene solutions using vaporisation in acetylene-air flame or in an electrothermally heated graphite furnace. The sensitive rotational lines of the CS molecule, belonging to the {Delta}{nu} = 0 vibrational sequence within the electronic transition X{sup 1}{Sigma}{sup +} {yields} A{sup 1}{Pi}, were applied. For graphite furnace molecular absorption spectrometry, the Pd + Mg organic modifier was selected. Strong interactions with Pd atoms enable easier decomposition of sulphur-containing compounds, likely through the temporal formation of Pd{sub x}S{sub y} molecules. At the 258.056 nm line, with the wavelength range covering central pixel {+-} 5 pixels and with application of interactive background correction, the detection limit was 14 ng in graphite furnace molecular absorption spectrometry and 18 mg kg{sup -1} in flame molecular absorption spectrometry. Meanwhile, application of 2-points background correction found a characteristic mass of 12 ng in graphite furnace molecular absorption spectrometry and a characteristic concentration of 104 mg kg{sup -1} in flame molecular absorption spectrometry. The range of application of the proposed methods turned out to be significantly limited by the properties of the sulphur compounds of interest. In the case of volatile sulphur compounds, which can be present in light petroleum products, severe difficulties were encountered. On the contrary, heavy oils and residues from distillation as well as crude oil could be analysed using both flame and graphite furnace vaporisation. The good accuracy of the proposed methods for these samples was confirmed by their mutual consistency and the results from analysis of reference samples (certified reference materials and home reference materials with

  20. Elimination of the inter-element interferences of iron, gold, molybdenum, tin and antimony when determined in organic solvents by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Aneva, Zara; Arpadjan, Sonja

    1988-01-01

    The mutual interferences in the flame atomic absorption spectrometric determination of iron, gold, molybdenum, tin and antimony after their extraction - pre-concentration as chloride complexes from platinum solutions into isobutyl methyl ketone are investigated. It is suggested that the interferences are caused by chemical reactions in the flame and are influenced by the flame characteristics. The possibility of eliminating the interferences by addition of long-chain quaternary ammonium salts is discussed. (author)

  1. Photoionization mass spectrometer for studies of flame chemistry with a synchrotron light source

    International Nuclear Information System (INIS)

    Cool, Terrill A.; McIlroy, Andrew; Qi, Fei; Westmoreland, Phillip R.; Poisson, Lionel; Peterka, Darcy S.; Ahmed, Musahid

    2005-01-01

    A flame-sampling molecular-beam photoionization mass spectrometer, recently designed and constructed for use with a synchrotron-radiation light source, provides significant improvements over previous molecular-beam mass spectrometers that have employed either electron-impact ionization or vacuum ultraviolet laser photoionization. These include superior signal-to-noise ratio, soft ionization, and photon energies easily and precisely tunable [E/ΔE(FWHM)≅250-400] over the 7.8-17-eV range required for quantitative measurements of the concentrations and isomeric compositions of flame species. Mass resolution of the time-of-flight mass spectrometer is m/Δm=400 and sensitivity reaches ppm levels. The design of the instrument and its advantages for studies of flame chemistry are discussed

  2. Determination of lithium and potassium in uranium oxide powders and pellets by Flame Atomic Emission Spectrometric method

    International Nuclear Information System (INIS)

    Jat, J.R.; Balaji Rao, Y.; Prasada Rao, G.; Prahlad, B.

    2012-01-01

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI 4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI 4 , is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO 2 powder and pellets on regular basis

  3. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    OpenAIRE

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S.; Korn, Maria das Graças Andrade; Bezerra, Marcos de Almeida

    2009-01-01

    Texto completo: acesso restrito. p. 1041-1045 A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L−1 nitric acid solution, the analytes are determinate employing fla...

  4. Minicolumn field preconcentration and flow-injection flame atomic absorption spectrometric determination of cadmium in seawater

    International Nuclear Information System (INIS)

    Yebra-Biurrun, M.C.; Moreno-Cid, A.; Puig, L.

    2004-01-01

    A simple method for the continuous field preconcentration of trace dissolved cadmium in seawater samples has been developed based on the minicolumn field sampling technique. For this purpose, minicolumns containing Chelite P (aminomethylphosphonic groups) were connected to a field flow preconcentration system (FFPS). Once in the laboratory, these minicolumns are sequentially inserted into a flow-injection system for on-line cadmium elution and detection by flame atomic absorption spectrometry. Factorial designs have been used to optimise the FFPS and the flow-injection elution process. Six experimental variables were optimised: sample pH, sample flow-rate, eluent concentration, eluent volume, eluent flow-rate and minicolumn diameter. The detection limit (3F) of the procedure was 2.7 ng l -1 for a sample volume of 300 ml. The precision (expressed as relative standard deviation) for 11 independent determinations was 0.5-9.4% for cadmium solutions of 10-300 ng l -1 . Analysis of certified reference materials (SLEW-3 and NASS-5) showed good agreement with the certified values. This procedure has been successfully applied to the determination of cadmium in seawater samples from Galicia (Spain)

  5. Determination of cadmium in real water samples by flame atomic absorption spectrometry after cloud point extraction

    International Nuclear Information System (INIS)

    Naeemullah, A.; Kazi, T.G.

    2011-01-01

    Water pollution is a global threat and it is the leading world wide cause of death and diseases. The awareness of the potential danger posed by heavy metals to the ecosystems and in particular to human health has grown tremendously in the past decades. Separation and preconcentration procedures are considered of great importance in analytical and environmental chemistry. Cloud point is one of the most reliable and sophisticated separation methods for determination of traces quantities of heavy metals. Cloud point methodology was successfully employed for preconcentration of trace quantities of cadmium prior to their determination by flame atomic absorption spectrometry (FAAS). The metals react with 8-hydroxquinoline in a surfactant Triton X-114 medium. The following parameters such as pH, concentration of the reagent and Triton X-114, equilibrating temperature and centrifuging time were evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method. Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation and the cadmium content was measured by FAAS. The validation of the procedure was carried out by spiking addition methods. The method was applied for determination of Cd in water samples of different ecosystems (lake and river). (author)

  6. Determination of iron in natural and mineral waters by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    ROLANDAS KAZLAUSKAS

    2004-05-01

    Full Text Available Simple methods for the determination of Fe in natural and mineral waters by flame atomic absorption spectrometry (AAS are suggested. The results of the investigation of selectivity of the proposed AAS method proved that this procedure is not affected by high concentrations of other metals. The calibration graph for iron was linear at levels near the detection limit up to at least 0.10 mg ml-1. For the determination of microamounts of iron in mineral waters, an extraction AAS technique was developed. Iron was retained as Fe-8-oxyquinoline complex and extracted into chloroform. The optimal conditions for the extraction of the iron complex were determined. The AAS method was applied to the determination of Fe in mineral waters and natural waters from different areas of Lithuania. The accuracy of the developed method was sufficient and evaluated in comparison with a photometric method. The obtained results demonstrated that the procedure could be successfully applied for the analysis of water samples with satisfactory accuracy.

  7. Determination of calcium and magnesium in hydroethanolic extracts of propolis by atomic absorption flame spectrophotometry

    Directory of Open Access Journals (Sweden)

    E. Q. SANTANA

    2009-01-01

    Full Text Available

    Propolis is a natural product collected by honeybees and has a large range of pharmacological activity, including antimicrobial, antitumoral, antioxidant and anti-inflammatory. Its use as a popular medicine is increasing all over the world, creating a need for quality control of the commercial products. In this study the levels of calcium and magnesium in commercial hydroalcoholic propolis extracts from varios states of Brazil were determined by atomic absorption flame spectrophotometry and different values were obtained for northern and southern states. This study can be extended to the analysis of metals that are harmful to health. The results showed that the calibration curves were linear over a wide concentration range (0.5-4.0 µg.mL-1 for calcium and 0.05-0.4 µg.mL-1 for magnesium with good correlation coefficients (0.999 and 0.988, respectively. Good analytical recovery (94% was obtained. The proposed method showed adequate precision and relative standard deviation lower than 2 %. The method is accurate and precise as well as having advantages such as simplicity and speed. Keywords: hydroalcoholic propolis extract; mineralization; analysis; calcium; magnesium.

  8. Fabrication of ultrathin multilayered superomniphobic nanocoatings by liquid flame spray, atomic layer deposition, and silanization

    Science.gov (United States)

    Sorvali, Miika; Vuori, Leena; Pudas, Marko; Haapanen, Janne; Mahlberg, Riitta; Ronkainen, Helena; Honkanen, Mari; Valden, Mika; Mäkelä, Jyrki M.

    2018-05-01

    Superomniphobic, i.e. liquid-repellent, surfaces have been an interesting area of research during recent years due to their various potential applications. However, producing such surfaces, especially on hard and resilient substrates like stainless steel, still remains challenging. We present a stepwise fabrication process of a multilayered nanocoating on a stainless steel substrate, consisting of a nanoparticle layer, a nanofilm, and a layer of silane molecules. Liquid flame spray was used to deposit a TiO2 nanoparticle layer as the bottom layer for producing a suitable surface structure. The interstitial Al2O3 nanofilm, fabricated by atomic layer deposition (ALD), stabilized the nanoparticle layer, and the topmost fluorosilane layer lowered the surface energy of the coating for enhanced omniphobicity. The coating was characterized with field emission scanning electron microscopy, focused ion beam scanning electron microscopy, x-ray photoelectron spectroscopy, contact angle (CA) and sliding angle (SA) measurements, and microscratch testing. The widely recognized requirements for superrepellency, i.e. CA > 150° and SA < 10°, were achieved for deioinized water, diiodomethane, and ethylene glycol. The mechanical stability of the coating could be varied by tuning the thickness of the ALD layer at the expense of repellency. To our knowledge, this is the thinnest superomniphobic coating reported so far, with the average thickness of about 70 nm.

  9. Speciation of iron (II) and (III) by using solvent extraction and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yaman, Mehmet; Kaya, Gokce

    2005-01-01

    A method for speciation, preconcentration and separation of Fe 2+ and Fe 3+ in different matrices was developed using solvent extraction and flame atomic absorption spectrometry. PAN as complexing reagent for Fe 2+ and chloroform as organic solvent were used. The complex of Fe 2+ -PAN was extracted into chloroform phase in the pH range of 0.75-4.0 and Fe 3+ remains in water phase in the pH range 0.75-1.25. The optimum conditions for maximum recovery of Fe 2+ and minimum recovery of Fe 3+ were determined as pH = 1, the stirring time of 20 min, the PAN amount of 0.5 mg and chloroform volume of 8 mL. The developed method was applied to the determination of Fe 2+ and Fe 3+ in tea infusion, fruit juice, cola and pekmez. It is seen that there is high bioavailable iron (Fe 2+ ) in pekmez. The developed method is sensitive, simple and need the shorter time in comparison with other similar studies

  10. Fabrication of ultrathin multilayered superomniphobic nanocoatings by liquid flame spray, atomic layer deposition, and silanization.

    Science.gov (United States)

    Sorvali, Miika; Vuori, Leena; Pudas, Marko; Haapanen, Janne; Mahlberg, Riitta; Ronkainen, Helena; Honkanen, Mari; Valden, Mika; Mäkelä, Jyrki M

    2018-05-04

    Superomniphobic, i.e. liquid-repellent, surfaces have been an interesting area of research during recent years due to their various potential applications. However, producing such surfaces, especially on hard and resilient substrates like stainless steel, still remains challenging. We present a stepwise fabrication process of a multilayered nanocoating on a stainless steel substrate, consisting of a nanoparticle layer, a nanofilm, and a layer of silane molecules. Liquid flame spray was used to deposit a TiO 2 nanoparticle layer as the bottom layer for producing a suitable surface structure. The interstitial Al 2 O 3 nanofilm, fabricated by atomic layer deposition (ALD), stabilized the nanoparticle layer, and the topmost fluorosilane layer lowered the surface energy of the coating for enhanced omniphobicity. The coating was characterized with field emission scanning electron microscopy, focused ion beam scanning electron microscopy, x-ray photoelectron spectroscopy, contact angle (CA) and sliding angle (SA) measurements, and microscratch testing. The widely recognized requirements for superrepellency, i.e. CA > 150° and SA layer at the expense of repellency. To our knowledge, this is the thinnest superomniphobic coating reported so far, with the average thickness of about 70 nm.

  11. ESR studies of Bunsen-type methane-air flames. II. The effects of the addition of halogenated compounds to the secondary air on the hydrogen atoms in the flame

    Energy Technology Data Exchange (ETDEWEB)

    Noda, S; Fujimoto, S; Claesson, O; Yoshida, H

    1983-09-01

    Hydrogen atoms in a methane-air Bunsen-type flame were detected by the flame-in-cavity ESR method. The addition of a halogenated compound to the secondary air reduced the H-atom concentration linearly with an increase in additive concentration. These 8 halogenated compounds examined showed increased effectiveness in scavenging H atoms in this order: hydrochloric acid < dichlorodifluoromethane < chloroform < methyl chloride < methylene chloride < trichlorofluoromethane < carbon tetrachlorie < methyl bromide. The chemical effects of these additives on the combustion reactions agree well with the inhibitor indices for these compounds. 14 references, 3 figures.

  12. Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Titretir, Serap, E-mail: serap.titretir@inonu.edu.tr [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); S Latin-Small-Letter-Dotless-I k, Ahmet Inanc [Department of Chemistry, Faculty of Arts and Sciences, Inoenue University, 44280 Malatya (Turkey); Arslan, Yasin [Department of Chemistry, Faculty of Arts and Sciences, Mehmet Akif Ersoy University, Istiklal Yerleskesi, 15030 Burdur (Turkey); Ataman, O. Yavuz [Department of Chemistry, Faculty of Arts and Sciences, Middle East Technical University, 06800 Ankara (Turkey)

    2012-11-15

    Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 {mu}g L{sup -1} when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: Black-Right-Pointing-Pointer Atom trapping in a quartz tube was used for Sb with flame AAS. Black-Right-Pointing-Pointer An inexpensive, simple and sensitive analytical method was suggested for Sb. Black-Right-Pointing-Pointer Almost no background absorption was observed. Black-Right-Pointing-Pointer Range is in microgram per liter level.

  13. Sensitivity improvement for antimony determination by using in-situ atom trapping in a slotted quartz tube and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Titretir, Serap; Şık, Ahmet İnanç; Arslan, Yasin; Ataman, O. Yavuz

    2012-01-01

    Significant improvement has been achieved for antimony determination using a slotted quartz tube (SQT) as an atom trap (AT) for in situ preconcentration and flame atomic absorption spectrometry (FAAS). The suggested technique consists of trapping analyte species during ordinary nebulization followed by releasing the collected analyte via introducing organic solvent. Procedures and analytical figures of merit have been presented for the techniques called FAAS, SQT-FAAS and finally SQT-AT-FAAS with the relevant comparisons. Analytical parameters, namely composition of the aqueous medium, sample flow rate, flame conditions, distance between burner head and SQT, sampling period and type of organic solvent and its volume have been optimized. Using SQT-AT-FAAS, a sensitivity enhancement of 369 fold has been obtained, 3 s limit of detection was 3.9 μg L −1 when 25.0 mL of sample was collected in 4.0 min. Interference effects of some elements on antimony signal were studied. - Highlights: ► Atom trapping in a quartz tube was used for Sb with flame AAS. ► An inexpensive, simple and sensitive analytical method was suggested for Sb. ► Almost no background absorption was observed. ► Range is in microgram per liter level.

  14. Method for producing uranium atomic beam source

    International Nuclear Information System (INIS)

    Krikorian, O.H.

    1976-01-01

    A method is described for producing a beam of neutral uranium atoms by vaporizing uranium from a compound UM/sub x/ heated to produce U vapor from an M boat or from some other suitable refractory container such as a tungsten boat, where M is a metal whose vapor pressure is negligible compared with that of uranium at the vaporization temperature. The compound, for example, may be the uranium-rhenium compound, URe 2 . An evaporation rate in excess of about 10 times that of conventional uranium beam sources is produced

  15. Determination of copper in powdered chocolate samples by slurry-sampling flame atomic-absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter N.L. dos; Silva, Erik G.P. da; Fernandes, Marcelo S.; Araujo, Rennan G.O.; Costa, Anto' ' enio C.S.; Ferreira, Sergio L.C. [Nucleo de Excelencia em Quimica Analitica da Bahia, Universidade Federal da Bahia, Instituto de Quimica, Salvador, Bahia (Brazil); Vale, M.G.R. [Instituto de Quimica, Universidade Federal da Bahia do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul (Brazil)

    2005-06-01

    Chocolate is a complex sample with a high content of organic compounds and its analysis generally involves digestion procedures that might include the risk of losses and/or contamination. The determination of copper in chocolate is important because copper compounds are extensively used as fungicides in the farming of cocoa. In this paper, a slurry-sampling flame atomic-absorption spectrometric method is proposed for determination of copper in powdered chocolate samples. Optimization was carried out using univariate methodology involving the variables nature and concentration of the acid solution for slurry preparation, sonication time, and sample mass. The recommended conditions include a sample mass of 0.2 g, 2.0 mol L{sup -1} hydrochloric acid solution, and a sonication time of 15 min. The calibration curve was prepared using aqueous copper standards in 2.0 mol L{sup -1} hydrochloric acid. This method allowed determination of copper in chocolate with a detection limit of 0.4 {mu}g g{sup -1} and precision, expressed as relative standard deviation (RSD), of 2.5% (n=10) for a copper content of approximately 30 {mu}g g{sup -1}, using a chocolate mass of 0.2 g. The accuracy was confirmed by analyzing the certified reference materials NIST SRM 1568a rice flour and NIES CRM 10-b rice flour. The proposed method was used for determination of copper in three powdered chocolate samples, the copper content of which varied between 26.6 and 31.5 {mu}g g{sup -1}. The results showed no significant differences with those obtained after complete digestion, using a t-test for comparison. (orig.)

  16. Interferometric measurement of lines shift in flames in connection with interpretation of lined absorption method in atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    L'vov, B.V.; Polzik, L.K.; Katskov, D.A.; Kruglikova, L.P.

    1975-01-01

    This paper is concerned with interferometric measuring of the line shift in flames in the view of interpretation of absorption lines in the atomic absorption spectroscopy. The newly measured line shifts were compared to the known data on Lorentz broadening of the same lines obtained by methods free of the systematic errors. The resonant lines of the alkaline earth elements (Sr, Ca, Ba) were investigated. To reduce self-absorption in the flame the solutions with minimum concentrations of the elements were used. The computation scheme includes the spectrometer apparatus width and line broadening due to the self-absorption. Formulae are given for computing the values studied. Good agreement was observed between the computed and experimental results. Error analysis was performed. It was concluded that any line shifts in the hydrocarbons were correctly taken into an account in the absolute computations of absorption

  17. Application of Internal Standard Method for Several 3d-Transition Metallic Elements in Flame Atomic Absorption Spectrometry Using a Multi-wavelength High-resolution Spectrometer.

    Science.gov (United States)

    Toya, Yusuke; Itagaki, Toshiko; Wagatsuma, Kazuaki

    2017-01-01

    We investigated a simultaneous internal standard method in flame atomic absorption spectrometry (FAAS), in order to better the analytical precision of 3d-transition metals contained in steel materials. For this purpose, a new spectrometer system for FAAS, comprising a bright xenon lamp as the primary radiation source and a high-resolution Echelle monochromator, was employed to measure several absorption lines at a wavelength width of ca. 0.3 nm at the same time, which enables the absorbances of an analytical line and also an internal standard line to be estimated. In considering several criteria for selecting an internal standard element and the absorption line, it could be suggested that platinum-group elements: ruthenium, rhodium, or palladium, were suitable for an internal standard element to determine the 3d-transition metal elements, such as titanium, iron, and nickel, by measuring an appropriate pair of these absorption lines simultaneously. Several variances of the absorption signal, such as a variation in aspirated amounts of sample solution and a short-period drift of the primary light source, would be corrected and thus reduced, when the absorbance ratio of the analytical line to the internal standard line was measured. In Ti-Pd, Ni-Rh, and Fe-Ru systems chosen as typical test samples, the repeatability of the signal respnses was investigated with/without the internal standard method, resulting in better precision when the internal standard method was applied in the FAAS with a nitrous oxide-acetylene flame rather than an air-acetylene flame.

  18. [Evaluation of uncertainty for determination of tin and its compounds in air of workplace by flame atomic absorption spectrometry].

    Science.gov (United States)

    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.

  19. Sources of polarized ions and atoms

    International Nuclear Information System (INIS)

    Cornelius, W.D.

    1988-01-01

    In this presentation we discuss methods of producing large quantities of polarized atoms and ions (Stern-Gerlach separation, optical pumping, and spin-exchange) as well as experimental methods of measuring the degree of polarization of atomic systems. The usefulness of polarized atoms in probing the microscopic magnetic surface properties of materials will also be discussed. 39 refs., 5 figs., 2 tabs

  20. Atomic-fluorescence spectrophotometry

    International Nuclear Information System (INIS)

    Bakhturova, N.F.; Yudelevich, I.G.

    1975-01-01

    Atomic-fluorescence spectrophotometry, a comparatively new method for the analysis of trace quantities, has developed rapidly in the past ten years. Theoretical and experimental studies by many workers have shown that atomic-fluorescence spectrophotometry (AFS) is capable of achieving a better limit than atomic absorption for a large number of elements. The present review examines briefly the principles of atomic-fluorescence spectrophotometry and the types of fluorescent transition. The excitation sources, flame and nonflame atomizers, used in AFS are described. The limits of detection achieved up to the present, using flame and nonflame methods of atomization are given

  1. Laser Source for Atomic Gravity Wave Detector

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atom Interferometry (AI) Technology for Gravity Wave Measurements demonstrates new matter wave Interferometric sensor technology for precise detection and...

  2. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry.

    Science.gov (United States)

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S; Korn, Maria G A; Bezerra, Marcos A

    2009-03-15

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L(-1) nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 microg L(-1), respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 microg L(-1). The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish.

  3. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Tuzen, Mustafa; Soylak, Mustafa; Citak, Demirhan; Ferreira, Hadla S.; Korn, Maria G.A.; Bezerra, Marcos A.

    2009-01-01

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L -1 nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 μg L -1 , respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 μg L -1 . The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish

  4. A preconcentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa [Department of Chemistry, Gaziosmanpasa University, 60250 Tokat (Turkey); Soylak, Mustafa [Department of Chemistry, Erciyes University, 38039 Kayseri (Turkey)], E-mail: soylak@erciyes.edu.tr; Citak, Demirhan [Department of Chemistry, Gaziosmanpasa University, 60250 Tokat (Turkey); Ferreira, Hadla S.; Korn, Maria G.A. [Universidade Federal da Bahia, Instituto de Quimica, 40170-290 Salvador (Brazil); Bezerra, Marcos A. [Universidade Estadual do Sudoeste da Bahia, 45200-190 Jequie (Brazil)

    2009-03-15

    A separation/preconcentration procedure using solid phase extraction has been proposed for the flame atomic absorption spectrometric determination of copper and nickel at trace level in food samples. The solid phase is Dowex Optipore SD-2 resin contained on a minicolumn, where analyte ions are sorbed as 5-methyl-4-(2-thiazolylazo) resorcinol chelates. After elution using 1 mol L{sup -1} nitric acid solution, the analytes are determinate employing flame atomic absorption spectrometry. The optimization step was performed using a full two-level factorial design and the variables studied were: pH, reagent concentration (RC) and amount of resin on the column (AR). Under the experimental conditions established in the optimization step, the procedure allows the determination of copper and nickel with limit of detection of 1.03 and 1.90 {mu}g L{sup -1}, respectively and precision of 7 and 8%, for concentrations of copper and nickel of 200 {mu}g L{sup -1}. The effect of matrix ions was also evaluated. The accuracy was confirmed by analyzing of the followings certified reference materials: NIST SRM 1515 Apple leaves and GBW 07603 Aquatic and Terrestrial Biological Products. The developed method was successfully applied for the determination of copper and nickel in real samples including human hair, chicken meat, black tea and canned fish.

  5. Sensitive determination of bismuth by flame atomic absorption spectrometry using atom trapping in a slotted quartz tube and revolatilization with organic solvent pulse

    International Nuclear Information System (INIS)

    Kılınç, Ersin; Bakırdere, Sezgin; Aydın, Fırat; Ataman, O. Yavuz

    2012-01-01

    Sensitivity of flame atomic absorption spectrometry (FAAS) for Bi determination was improved by slotted quartz tube (SQT) that was used also for atom trapping (AT). The trapped analyte was released by aspirating a small volume of organic solvent after a reasonable analyte collection time. Sensitivity was improved by 2.9 times by SQT-FAAS and 256 times by SQT-AT-FAAS with respect to FAAS. Optimum trapping period was found to be 6.0 min (36.0 mL of solution). Limit of detection (LOD) for SQT-AT-FAAS was found to be 1.6 ng mL −1 . %RSD was calculated as 4.0% for five replicate measurements of 7.5 ng mL −1 Bi by SQT-AT-FAAS. Accuracy of the method developed was checked by analyzing a standard reference material of simulated fresh water (NIST 1643e) and result found was in good agreement with the certified one. The method can be applied in any laboratory equipped with a flame AA spectrometer. The consumption of time and sample volume is fairly low and application is simple and easy.

  6. Sensitive determination of bismuth by flame atomic absorption spectrometry using atom trapping in a slotted quartz tube and revolatilization with organic solvent pulse

    Energy Technology Data Exchange (ETDEWEB)

    K Latin-Small-Letter-Dotless-I l Latin-Small-Letter-Dotless-I nc, Ersin, E-mail: ekilinc@dicle.edu.tr [Dicle University, Faculty of Science, Department of Chemistry, Laboratory of Chemical Analysis, TR 21280 Diyarbak Latin-Small-Letter-Dotless-I r (Turkey); Bak Latin-Small-Letter-Dotless-I rdere, Sezgin [Y Latin-Small-Letter-Dotless-I ld Latin-Small-Letter-Dotless-I z Technical University, Faculty of Education, Department of Science Education, TR 34210 Esenler-Istanbul (Turkey); Ayd Latin-Small-Letter-Dotless-I n, F Latin-Small-Letter-Dotless-I rat [Dicle University, Faculty of Science, Department of Chemistry, Laboratory of Chemical Analysis, TR 21280 Diyarbak Latin-Small-Letter-Dotless-I r (Turkey); Ataman, O. Yavuz [Middle East Technical University, Faculty of Arts and Sciences, Department of Chemistry, 06800 Ankara (Turkey)

    2012-07-15

    Sensitivity of flame atomic absorption spectrometry (FAAS) for Bi determination was improved by slotted quartz tube (SQT) that was used also for atom trapping (AT). The trapped analyte was released by aspirating a small volume of organic solvent after a reasonable analyte collection time. Sensitivity was improved by 2.9 times by SQT-FAAS and 256 times by SQT-AT-FAAS with respect to FAAS. Optimum trapping period was found to be 6.0 min (36.0 mL of solution). Limit of detection (LOD) for SQT-AT-FAAS was found to be 1.6 ng mL{sup -1}. %RSD was calculated as 4.0% for five replicate measurements of 7.5 ng mL{sup -1} Bi by SQT-AT-FAAS. Accuracy of the method developed was checked by analyzing a standard reference material of simulated fresh water (NIST 1643e) and result found was in good agreement with the certified one. The method can be applied in any laboratory equipped with a flame AA spectrometer. The consumption of time and sample volume is fairly low and application is simple and easy.

  7. Lead determination at ng/mL level by flame atomic absorption spectrometry using a tantalum coated slotted quartz tube atom trap.

    Science.gov (United States)

    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

  8. Speciation of four selenium compounds using high performance liquid chromatography with on-line detection by inductively coupled plasma mass spectrometry or flame atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Pedersen, Gitte Alsing; Larsen, Erik Huusfeldt

    1997-01-01

    An analytical method for the speciation of selenomethionine, selenocystine, selenite and selenate by high performance liquid chromatography (HPLC) with atomic spectrometric detection is presented. An organic polymeric strong anion exchange column was used as the stationary phase in combination...... spectrometry (ICP-MS). The signal-to-noise ratio of the FAAS detector was optimized using a hydrogen-argon entrained-air flame and a slotted-tube atom trap (STAT) in the flame. The limit of detection (3 sigma) achieved by the HPLC-FAAS system was 1 mg L-1 of selenium (100 mu L injections) for each of the four...

  9. Effect of oxygen atoms dissociated by non-equilibrium plasma on flame of methane oxygen and argon pre-mixture gas

    Science.gov (United States)

    Akashi, Haruaki; Yoshinaga, Tomokazu; Sasaki, Koichi

    2014-10-01

    For more efficient way of combustion, plasma-assisted combustion has been investigated by many researchers. But it is very difficult to clarify the effect of plasma even on the flame of methane. Because there are many complex chemical reactions in combustion system. Sasaki et al. has reported that the flame length of methane and air premixed burner shortened by irradiating microwave power. They also measured emission from Second Positive Band System of nitrogen during the irradiation. The emission indicates existence of high energy electrons which are accelerated by the microwave. The high energy electrons also dissociate oxygen molecules easily and oxygen atom would have some effects on the flame. But the dissociation ratio of oxygen molecules by the non-equilibrium plasma is significantly low, compared to that in the combustion reaction. To clarify the effect of dissociated oxygen atoms on the flame, dependence of dissociation ratio of oxygen on the flame has been examined using CHEMKIN. It is found that in the case of low dissociation ratio of 10-6, the ignition of the flame becomes slightly earlier. It is also found that in the case of high dissociation ratio of 10-3, the ignition time becomes significantly earlier by almost half. This work was supported by KAKENHI (22340170).

  10. Charge-induced secondary atomization in diffusion flames of electrostatic sprays

    Science.gov (United States)

    Gomez, Alessandro; Chen, Gung

    1994-01-01

    The combustion of electrostatic sprays of heptane in laminar counterflow diffusion flames was experimentally studied by measuring droplet size and velocity distributions, as well as the gas-phase temperature. A detailed examination of the evolution of droplet size distribution as droplets approach the flame shows that, if substantial evaporation occurs before droplets interact with the flame, an initially monodisperse size distribution becomes bimodal. A secondary sharp peak in the size histogram develops in correspondence of diameters about one order of magnitude smaller than the mean. No evaporation mechanism can account for the development of such bimodality, that can be explained only in terms of a disintegration of droplets into finer fragments of size much smaller than that of the parent. Other evidence in support of this interpretation is offered by the measurements of droplet size-velocity correlation and velocity component distributions, showing that, as a consequence of the ejection process, the droplets responsible for the secondary peak have velocities uncorrelated with the mean flow. The fission is induced by the electric charge. When a droplet evaporates, in fact, the electric charge density on the droplet surface increases while the droplet shrinks, until the so-called Rayleigh limit is reached at which point the repulsion of electric charges overcomes the surface tension cohesive force, ultimately leading to a disintegraton into finer fragments. We report on the first observation of such fissions in combustion environments. If, on the other hand, insufficient evaporation has occurred before droplets enter the high temperature region, there appears to be no significant evidence of bimodality in their size distribution. In this case, in fact, the concentration of flame chemi-ions or, in the case of positively charged droplets, electrons may be sufficient for them to neutralize the charge on the droplets and to prevent disruption.

  11. Development and Validation of a Sensitive Method for Trace Nickel Determination by Slotted Quartz Tube Flame Atomic Absorption Spectrometry After Dispersive Liquid-Liquid Microextraction.

    Science.gov (United States)

    Yolcu, Şükran Melda; Fırat, Merve; Chormey, Dotse Selali; Büyükpınar, Çağdaş; Turak, Fatma; Bakırdere, Sezgin

    2018-05-01

    In this study, dispersive liquid-liquid microextraction was systematically optimized for the preconcentration of nickel after forming a complex with diphenylcarbazone. The measurement output of the flame atomic absorption spectrometer was further enhanced by fitting a custom-cut slotted quartz tube to the flame burner head. The extraction method increased the amount of nickel reaching the flame and the slotted quartz tube increased the residence time of nickel atoms in the flame to record higher absorbance. Two methods combined to give about 90 fold enhancement in sensitivity over the conventional flame atomic absorption spectrometry. The optimized method was applicable over a wide linear concentration range, and it gave a detection limit of 2.1 µg L -1 . Low relative standard deviations at the lowest concentration in the linear calibration plot indicated high precision for both extraction process and instrumental measurements. A coal fly ash standard reference material (SRM 1633c) was used to determine the accuracy of the method, and experimented results were compatible with the certified value. Spiked recovery tests were also used to validate the applicability of the method.

  12. Monitoring content of cadmium, calcium, copper, iron, lead, magnesium and manganese in tea leaves by electrothermal and flame atomizer atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Prkić Ante

    2017-08-01

    Full Text Available Due to the simplicity of tea preparation (pouring hot water onto different dried herbs and its high popularity as a beverage, monitoring and developing a screening methodology for detecting the metal content is very important. The concentrations of Cd, Ca, Cu, Fe, Pb, Mg and Mn in 11 different samples of sage (Salvia officinalis L., linden (Tilia L. and chamomile (Matricaria chamomilla L. purchased at local herbal pharmacy were determined using electrothermal atomizer atomic absorption spectrometry (ETAAS and flame atomizer atomic absorption spectrometry (FAAS. The concentrations determined were: Cd (0.012 – 0.470 mg kg−1, Ca (5209 – 16340 mg kg−1, Cu (22.01 – 33.05 mg kg−1, Fe (114.2 – 440.3 mg kg−1, Pb (0.545 – 2.538 mg kg−1, Mg (2649 – 4325 mg kg−1 and Mn (34.00 – 189.6 mg kg−1. Principal Component Analysis (PCA was applied to identify factors (soil and climate influencing the content of the measured elements in herbal samples. The proposed methodology developed in this work was successfully applied to the detection of metals in herbal samples. The analysis showed that the content of toxic metals in herbal teas was below the maximum dose recommended by the World Health Organization (WHO.

  13. Influence of soil composition in the determination of chromium by atomic absorption spectrometry with flame air / acetylene

    International Nuclear Information System (INIS)

    Duran Sosa, Ibis; Granda Valdes, Mayra; Pomares Alfonso, Mario Simeon

    2014-01-01

    The Air-acetylene Flame Atomic Absorption determination of chromium is a complex task, being strongly influenced by sample composition and instrumental conditions. The objective of this work was to study the influence of Al, Ca, Fe, K, Mg, and Na on the absorption of chromium in the air-acetylene flame, both separately and combined in solution, when acetylene flow and burner height vary. Dissolutions of the mixtures simulated the composition of four soils from the Quibu River Basin in Havana, Cuba. Chromium absorption first increased and then decreased with increment of acetylene flow for shorter burner heights (∼ 2-4 mm); while a continuous increase was observed for larger heights (> 4 mm). This behavior was the same in the presence and absence of interfering chemical element, mentioned above. On the other hand, the dependence of the magnitude of the interference with acetylene flow and burner height was complex and dependent on the interfering element, particularly at larger heights where the behavior of Al was remarkably different. The interference of the four mixtures of Al, Ca, K, Fe, Mg and Na decreased in comparison to individual interfering effects and was less dependent on acetylene flow and burner height. Finally, a significant reduction of interference on chromium determination in soil samples was achieved by an adequate selection of acetylene flow and burner height

  14. Separation of seven arsenic compounds by high performance liquid chromatography with on-line detection by hydrogen-argon flame atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, S. H.; Larsen, Erik Huusfeldt; Pritzl, G.

    1992-01-01

    -to-noise ratio of the on-line AAS detector was optimized. This involved the use of the hydrogen-argon-entrained air flame, a slotted tube atom trap in the flame for signal enhancement, electronic noise damping and a high-intensity light source. The detection limits in mu-g cm-3, using 100 mm3 injections...... of mixtures of arsenic standards into the HPLC system were: arsenite, As(III) 1.1; arsenate, As(V) 1.4; MMA 1.4; DMA 0.7; AsB 0.3; AsC 0.5; and the TMAs 0.4. The HPLC-AAS system was used for the analysis of arsenic species in aqueous extracts of soil samples from a polluted land site. Only arsenate was found...

  15. Determination of Fe Content of Some Food Items by Flame Atomic Absorption Spectroscopy (FAAS): A Guided-Inquiry Learning Experience in Instrumental Analysis Laboratory

    Science.gov (United States)

    Fakayode, Sayo O.; King, Angela G.; Yakubu, Mamudu; Mohammed, Abdul K.; Pollard, David A.

    2012-01-01

    This article presents a guided-inquiry (GI) hands-on determination of Fe in food samples including plantains, spinach, lima beans, oatmeal, Frosted Flakes cereal (generic), tilapia fish, and chicken using flame atomic absorption spectroscopy (FAAS). The utility of the GI experiment, which is part of an instrumental analysis laboratory course,…

  16. Rapid Determination of Trace Palladium in Active Pharmaceutical Ingredients by Magnetic Solid-Phase Extraction and Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Yin, Q. H.; Zhu, D. M.; Yang, D. Z.; Hu, Q. F.; Yang, Y. L.

    2018-01-01

    Clutaraldehyde cross-linked magnetic chitosan nanoparticles were synthesized and used as an adsorbent for the dispersive solid-phase extraction of palladium in active pharmaceutical ingredients (APIs) prior to analysis by a flame atomic absorption spectrophotometer. FT-IR, X-ray diffraction, and TEM were used to characterize the adsorbent. Various parameters of experimental performance, such as adsorbent amount, pH, adsorption time, desorption solutions, coexisting ions, and adsorbent reusability, were investigated and optimized. Under the optimized conditions, good linearity was achieved in the 5.0-500 μg/L concentration range, with correlation coefficients of 0.9989. The limit of detection is 2.8 μg/L and the recoveries of spiked samples ranged from 91.7 to 97.6%. It was confirmed that the GMCNs nanocomposite was a promising adsorbing material for extraction and preconcentration of Pd in APIs.

  17. Separation and enrichment of gold(III) from environmental samples prior to its flame atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    Senturk, Hasan Basri; Gundogdu, Ali; Bulut, Volkan Numan; Duran, Celal; Soylak, Mustafa; Elci, Latif; Tufekci, Mehmet

    2007-01-01

    A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 mol L -1 HNO 3 in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 μg L -1 , respectively. The preconcentration factor was 200. The relative standard deviation of the method was -1 . The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples

  18. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium and nickel in drinking and wastewater samples.

    Science.gov (United States)

    Naeemullah; Kazi, Tasneem G; Shah, Faheem; Afridi, Hassan I; Baig, Jameel Ahmed; Soomro, Abdul Sattar

    2013-01-01

    A simple method for the preconcentration of cadmium (Cd) and nickel (Ni) in drinking and wastewater samples was developed. Cloud point extraction has been used for the preconcentration of both metals, after formation of complexes with 8-hydroxyquinoline (8-HQ) and extraction with the surfactant octylphenoxypolyethoxyethanol (Triton X-114). Dilution of the surfactant-rich phase with acidified ethanol was performed after phase separation, and the Cd and Ni contents were measured by flame atomic absorption spectrometry. The experimental variables, such as pH, amounts of reagents (8-HQ and Triton X-114), temperature, incubation time, and sample volume, were optimized. After optimization of the complexation and extraction conditions, enhancement factors of 80 and 61, with LOD values of 0.22 and 0.52 microg/L, were obtained for Cd and Ni, respectively. The proposed method was applied satisfactorily for the determination of both elements in drinking and wastewater samples.

  19. Membrane filtration of nickel(II) on cellulose acetate filters for its preconcentration, separation, and flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Soylak, Mustafa [Chemistry Dept., Faculty of Science Arts, University of Erciyes, Kayseri (Turkey); Unsal, Yunus Emre; Aydin, Ayse [Fen Bilimleri Enstitusu, University of Erciyes, Kayseri (Turkey); Kizil, Nebiye [Saglik Bilimleri Enstitusu, University of Erciyes, Kayseri (Turkey)

    2010-01-15

    An enrichment method for trace amounts of Ni(II), as 8-hydroxyquinoline chelates, has been established on a cellulose acetate membrane filter. Ni(II)-8-hydroxyquinoline chelates adsorbed on a membrane filter were eluted using 5 mL of 1 M HNO{sub 3}. The eluent nickel concentration was determined by a flame atomic absorption spectrometer. The influence of some analytical parameters, including pH, amount of reagent, sample volume, etc., on recovery was investigated. The interference of co-existent ions was studied. The nickel detection limit was 4.87 {mu}g/L. The method was applied to real samples for the determination of nickel(II) ions. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. A Compact, High-Flux Cold Atom Beam Source

    Science.gov (United States)

    Kellogg, James R.; Kohel, James M.; Thompson, Robert J.; Aveline, David C.; Yu, Nan; Schlippert, Dennis

    2012-01-01

    The performance of cold atom experiments relying on three-dimensional magneto-optical trap techniques can be greatly enhanced by employing a highflux cold atom beam to obtain high atom loading rates while maintaining low background pressures in the UHV MOT (ultra-high vacuum magneto-optical trap) regions. Several techniques exist for generating slow beams of cold atoms. However, one of the technically simplest approaches is a two-dimensional (2D) MOT. Such an atom source typically employs at least two orthogonal trapping beams, plus an additional longitudinal "push" beam to yield maximum atomic flux. A 2D atom source was created with angled trapping collimators that not only traps atoms in two orthogonal directions, but also provides a longitudinal pushing component that eliminates the need for an additional push beam. This development reduces the overall package size, which in turn, makes the 2D trap simpler, and requires less total optical power. The atom source is more compact than a previously published effort, and has greater than an order of magnitude improved loading performance.

  1. Multi-Channel Tunable Source for Atomic Sensors, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II SBIR will seek to develop a prototype laser source suitable for atomic interferometry from compact, robust, integrated components. AdvR's design is...

  2. Atomic physics at high brilliance synchrotron sources: Proceedings

    International Nuclear Information System (INIS)

    Berry, G.; Cowan, P.; Gemmell, D.

    1994-08-01

    This report contains papers on the following topics: present status of SPring-8 and the atomic physics undulator beamline; recent photoabsorption measurements in the rare gases and alkalis in the 3 to 15 keV proton energy region; atomic and molecular physics at LURE; experiments on atoms, ions and small molecules using the new generation of synchrotron radiation sources; soft x-ray fluorescence spectroscopy using tunable synchrotron radiation; soft x-ray fluorescence spectroscopy excited by synchrotron radiation: Inelastic and resonant scattering near threshold; outer-shell photoionization of ions; overview of the APS BESSRC beamline development; the advanced light source: Research opportunities in atomic and molecular physics; Photoionization of the Ba + ion by 4d shell excitation; decay dynamics of inner-shell excited atoms and molecules; absorption of atomic Ca, Cr, Mn and Cu; High-resolution photoelectron studies of resonant molecular photoionization; radiative and radiationless resonant raman scattering by synchrotron radiation; auger spectrometry of atoms and molecules; some thoughts of future experiments with the new generation of storage rings; Electron spectroscopy studies of argon K-shell excitation and vacancy cascades; ionization of atoms by high energy photons; ion coincidence spectroscopy on rare gas atoms and small molecules after photoexcitation at energies of several keV; an EBIS for use with synchrotron radiation photoionization of multiply charged ions and PHOBIS; gamma-2e coincidence measurements the wave of the future in inner-shell electron spectroscopy; recoil momentum spectroscopy in ion-atom and photon-atom collisions; a study of compton ionization of helium; future perspectives of photoionization studies at high photon energies; and status report on the advanced photon source. These papers have been cataloged separately elsewhere

  3. Simultaneous preconcentration of Cu, Fe and Pb as methylthymol blue complexes on naphthalene adsorbent and flame atomic absorption determination

    International Nuclear Information System (INIS)

    Pourreza, Nahid; Hoveizavi, Reza

    2005-01-01

    A simultaneous preconcentration method was developed for determination of trace amounts of Cu, Fe and Pb by atomic absorption spectrometry. The method is based on the retention of their methylthymol blue complexes by naphthalene methyltrioctyl ammonium chloride adsorbent in a column. The adsorbed metal complexes were eluted from the column with nitric acid and Cu, Fe and Pb were determined by flame atomic absorption spectrometry. Several parameters such as pH of the sample solution, ligand concentration, volume of the sample and the amount of methyltrioctyl ammonium chloride loaded on naphthalene were evaluated. The effect of diverse ions on the preconcentration was also investigated. A preconcentration factor of up to 100 or more can easily be achieved depending on the volume of the sample taken. The calibration graphs were obtained in the range of 5-40, 10-100 and 10-200 ng ml -1 for Cu, Fe and Pb in the initial solution, respectively, when using 500 ml of the solution. The detection limit based on three standard deviations of the blank was 0.54, 3.1, and 4.5 ng ml -1 for Cu, Fe and Pb, respectively. The relative standard deviations (R.S.D.) of 0.62-1.4% for Cu, 1.9-3.4% for Fe and 1.0-2.2% for Pb were obtained. The method was applied to the determination of Cu, Fe and Pb in river and wastewater samples

  4. Introduction of Flame Atomic Absorption Spectrometry (FAAS) For River Water Samples Analysis

    International Nuclear Information System (INIS)

    Shakirah Abd Shukor; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman

    2015-01-01

    Metal contamination in water is a major component in the determination of water quality monitoring. In spite of the viability of several other metal ion analysis techniques for river water, atomic absorption spectroscopy (AAS) method is most commonly used due to the reproducibility results, short analysis time, cost effective, lower level detection and robust. Therefore, this article gives an overview on the principles, instrumentation techniques, sample preparations, instrument calibration and data analysis in a simple manner for beginner. (author)

  5. Investigation of phosphorus atomization using high-resolution continuum source electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Welz, Bernhard; Heitmann, Uwe

    2007-01-01

    The atomization of phosphorus in electrothermal atomic absorption spectrometry has been investigated using a high-resolution continuum source atomic absorption spectrometer and atomization from a graphite platform as well as from a tantalum boat inserted in a graphite tube. A two-step atomization mechanism is proposed for phosphorus, where the first step is a thermal dissociation, resulting in a fast atomization signal early in the atomization stage, and the second step is a slow release of phosphorus atoms from the graphite tube surface following the adsorption of molecular phosphorus at active sites of the graphite surface. Depending on experimental conditions only one of the mechanisms or both might be active. In the absence of a modifier and with atomization from a graphite or tantalum platform the second mechanism appears to be dominant, whereas in the presence of sodium fluoride as a modifier both mechanisms are observed. Intercalation of phosphorus into the graphite platform in the condensed phase has also been observed; this phosphorus, however, appears to be permanently trapped in the structure of the graphite and does not contribute to the absorption signal

  6. Single-laboratory evaluation of SW-846 Methods 7090/7091 determination of beryllium by flame and furnace atomic absorption spectrophotometry. Summary report January-August 1987

    International Nuclear Information System (INIS)

    Hodge, V.F.; Darby, D.A.; Thompson, W.E.; Jones, C.L.

    1988-02-01

    The results of a single-laboratory study of the Determination of Beryllium by Flame and Furnace Atomic Absorption Spectrophotometry, are described. The study examined the application of these two powerful beryllium detection methods to the analysis of selected liquid and solid samples after digestion by appropriate SW-846 methods. Method performance data including detection limits, optimum concentration ranges (linearity), spike recoveries, interferences, precision, accuracy, and optimum operating parameters are presented and discussed

  7. Flame Atomic Absorption Determination of Gold Ion in Aqueous Samples after Preconcentration Using 9-Acridinylamine Functionalized γ-Alumina Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mohammad Karimi

    2013-01-01

    Full Text Available A simple and sensitive solid phase extraction utilizing 9-acridinylamine functionalized alumina nanoparticles was developed, and their potential use for preconcentration and subsequent determination of gold by flame atomic absorption spectrometry (FAAS was investigated. A number of parameters, namely, type, concentration, and volume of eluent, pH of the sample solution, flow rate of extraction, and volume of the sample, were evaluated. The effect of a variety of ions on preconcentration and recovery was also investigated. Gold ions were found to be recovered quantitatively at pH 3.0, with 0.1 mol L−1 thiourea in 2 mol L−1 H2SO4 as eluent. The limit of detection (LOD, defined as five times the standard deviation of the blank, was determined to be lower than 13.0 ppb. Under optimum conditions, the accuracy and precision (RSD% of the method were >98.0 and <1.5%, respectively. To gauge its ability in terms of application to real samples, the proposed method was successfully applied for determination of gold concentration in waste water samples and one soil standard material, and satisfactory results were obtained.

  8. Graphene oxide sheets immobilized polystyrene for column preconcentration and sensitive determination of lead by flame atomic absorption spectrometry.

    Science.gov (United States)

    Islam, Aminul; Ahmad, Hilal; Zaidi, Noushi; Kumar, Suneel

    2014-08-13

    A novel solid-phase extractant was synthesized by coupling graphene oxide (GO) on chloromethylated polystyrene through an ethylenediamine spacer unit to develop a column method for the preconcentration/separation of lead prior to its determination by flame atomic absorption spectrometry. It was characterized by Fourier transform infrared spectroscopy, far-infrared spectroscopy, thermogravimetric analysis/differential thermal analysis, scanning electron microscopy, energy-dispersive spectrometry, and transmission electron microscopy. The abundant oxygen-containing surface functional groups form a strong complex with lead, resulting in higher sorption capacity (227.92 mg g(-1)) than other nanosorbents used for sorption studies of the column method. Using the column procedure here is an alternative to the direct use of GO, which restricts irreversible aggregation of GO and its escape into the ecosystem, making it an environmentally sustainable method. The column method was optimized by varying experimental variables such as pH, flow rate for sorption/desorption, and elution condition and was observed to exhibit a high preconcentration factor (400) with a low preconcentration limit (2.5 ppb) and a high degree of tolerance for matrix ions. The accuracy of the proposed method was verified by determining the Pb content in the standard reference materials and by recovery experiments. The method showed good precision with a relative standard deviation <5%. The proposed method was successfully applied for the determination of lead in tap water, electroplating wastewater, river water, and food samples after preconcentration.

  9. [Determination of metals in waste bag filter of steel works by microwave digestion-flame atomic absorption spectrometry].

    Science.gov (United States)

    Ning, Xun-An; Zhou, Yun; Liu, Jing-Yong; Wang, Jiang-Hui; Li, Lei; Ma, Xiao-Guo

    2011-09-01

    A method of microwave digestion technique-flame atomic absorption spectrometry was proposed to determine the total contents of Cu, Zn, Pb, Cd, Cr and Ni in five different kinds of waste bag filters from a steel plant. The digestion effects of the six acid systems on the heavy metals digestion were studied for the first time. The relative standard deviation (RSD) of the method was between 1.02% and 9.35%, and the recovery rates obtained by standard addition method ranged from 87.7% to 105.6%. The results indicated that the proposed method exhibited the advantages of simplicity, speediness, accuracy and repeatability, and it was suitable for determining the metal elements of the waste bag filter. The results also showed that different digestion systems should be used according to different waste bag filters. The waste bag filter samples from different production processes had different metal elements content. The Pb and Zn were the highest in the waste bag filters, while the Cu, Ni, Cd and Cr were relatively lower. These determination results provided the scientific data for further treatment and disposal of the waste bag filter.

  10. Direct analysis of Antarctic krill by slurry sampling: determination of copper, iron, manganese and zinc by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Alves Flávia L.

    2000-01-01

    Full Text Available Slurry sampling in combination with flame atomic absorption spectrometry was employed for the direct determination of four essential trace elements, namely Cu, Fe, Mn and Zn in Antarctic krill. The effect of instrumental operating conditions and slurry sampling preparation on the analytical signal was investigated. For the determination of Cu, Fe and Zn, samples were suspended in a solution containing 2 mol L-1 HNO3. In the case of Mn, 4 mol L-1 HNO3 was necessary for the preparation of the slurry. The precision between sample replicates was better than 5%. The method was applied to the direct determination of Cu, Fe, Mn and Zn in Antarctic krill samples using aqueous reference solutions to prepare the calibration curves. The results obtained were in good agreement with those achieved by FAAS and ICP-AES after microwave-assisted wet digestion of the krill samples. The detection limits were 4.5, 1.0, 4.9 and 8.4 mug L-1 for Cu, Zn, Mn and Fe, respectively.

  11. Preconcentration and determination of zinc and lead ions by a combination of cloud point extraction and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tavallali, H. [Chemistry Department, Payamenore University, Shiraz (Iran); Shokrollahi, A.; Zahedi, M. [Chemistry Department, Yasouj University, Yasouj (Iran); Niknam, K. [Chemistry Department, Persian Gulf University, Bushehr (Iran); Soylak, M. [Chemistry Department, University of Erciyes, Kayseri (Turkey); Ghaedi, M.

    2009-04-15

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead(II) and zinc(II). After complexation with 3-[(4-bromophenyl) (1-H-inden-3-yl)methyl]-1 H-indene (BPIMI), the analytes were quantitatively extracted to a phase rich in Triton X-114 after centrifugation. Methanol acidified with 1 mol/L HNO{sub 3} was added to the surfactant rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of bis((1H-benzo [d] imidazol-2yl)ethyl)sulfane, Triton X-114, pH and amount of surfactant were all optimized. Detection limits (3 SDb/m) of 2.5 and 1.6 ng/mL for Pb{sup 2+} and Zn{sup 2+} along with preconcentration factors of 30 and an enrichment factor of 32 and 48 for Pb{sup 2+}and Zn {sup 2+} ions were obtained, respectively. The proposed cloud point extraction was been successfully applied for the determination of these ions in real samples with complicated matrices such as food and soil samples, with high efficiency. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  12. Graphene for separation and preconcentration of trace amounts of cobalt in water samples prior to flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Yukun Wang

    2016-09-01

    Full Text Available A new sensitive and simple method was developed for the preconcentration of trace amounts of cobalt (Co using 1-(2-pyridylazo-2-naphthol (PAN as chelating reagent prior to its determination by flame atomic absorption spectrometry. The proposed method is based on the utilization of a column packed with graphene as sorbent. Several effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 5.0–240.0 μg L−1 with a detection limit of 0.36 μg L−1. The relative standard deviation for ten replicate measurements of 20.0 and 100.0 μg L−1 of Co were 3.45 and 3.18%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Co. The proposed method was successfully applied in the analysis of four real environmental water samples. Good spiked recoveries over the range of 95.8–102.6% were obtained.

  13. Simultaneous preconcentration of cadmium and lead in water samples with silica gel and determination by flame atomic absorption spectrometry.

    Science.gov (United States)

    Xu, Hongbo; Wu, Yun; Wang, Jian; Shang, Xuewei; Jiang, Xiaojun

    2013-12-01

    A new method that utilizes pretreated silica gel as an adsorbent has been developed for simultaneous preconcentration of trace Cd(II) and Pb(II) prior to the measurement by flame atomic absorption spectrometry. The effects of pH, the shaking time, the elution condition and the coexisting ions on the separation/preconcentration conditions of analytes were investigated. Under optimized conditions, the static adsorption capacity of Cd(II) and Pb(II) were 45.5 and 27.1mg/g, the relative standard deviations were 3.2% and 1.7% (for n = 11), and the limits of detection obtained were 4.25 and 0.60 ng/mL, respectively. The method was validated by analyzing the certified reference materials GBW 07304a (stream sediment) and successfully applied to the analysis of various treated wastewater samples with satisfactory results. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  14. Separation and enrichment of gold(III) from environmental samples prior to its flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Senturk, Hasan Basri; Gundogdu, Ali [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 28049 Giresun (Turkey); Duran, Celal [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Arts and Sciences, Erciyes University, 38039 Kayseri (Turkey)], E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Arts and Sciences, Pamukkale University, 20020 Denizli (Turkey); Tufekci, Mehmet [Department of Chemistry, Faculty of Arts and Sciences, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2007-10-22

    A simple and accurate method was developed for separation and enrichment of trace levels of gold in environmental samples. The method is based on the adsorption of Au(III)-diethyldithiocarbamate complex on Amberlite XAD-2000 resin prior to the analysis of gold by flame atomic absorption spectrometry after elution with 1 mol L{sup -1} HNO{sub 3} in acetone. Some parameters including nitric acid concentration, eluent type, matrix ions, sample volume, sample flow rate and adsorption capacity were investigated on the recovery of gold(III). The recovery values for gold(III) and detection limit of gold were greater than 95% and 16.6 {mu}g L{sup -1}, respectively. The preconcentration factor was 200. The relative standard deviation of the method was <6%. The adsorption capacity of the resin was 12.3 mg g{sup -1}. The validation of the presented procedure was checked by the analysis of CRM-SA-C Sandy Soil certified reference material. The presented procedure was applied to the determination of gold in some environmental samples.

  15. Sensitive determination of cadmium using solidified floating organic drop microextraction-slotted quartz tube-flame atomic absorption spectroscopy.

    Science.gov (United States)

    Akkaya, Erhan; Chormey, Dotse Selali; Bakırdere, Sezgin

    2017-09-20

    In this study, solidified floating organic drop microextraction (SFODME) by 1-undecanol was combined with slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) for the determination of cadmium at trace levels. Formation of a complex with 4,4'-dimethyl-2,2'-bipyridine facilitated the extraction of cadmium from aqueous solutions. Several chemical variables were optimized in order to obtain high extraction outputs. Parameters such as concentration of the ligand, pH, and amount of buffer solution were optimized to enhance the formation of cadmium complex. The SFODME method was assisted by dispersion of extractor solvent into aqueous solutions using 2-propanol. Under the optimum extraction and instrumental conditions, the limit of detection and limit of quantitation values obtained for cadmium using the combined methods (SFODME-SQT-FAAS) were found to be 0.4 and 1.3 μg L -1 , respectively. Matrix effects on the method were also examined for tap water and wastewater, and spiked recovery results were found to be very satisfactory. Graphical Abstract SFODME-SQT-FAAS system for sensitive determination of cadmium.

  16. Cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry after ultrasound-assisted sample preparation

    International Nuclear Information System (INIS)

    Aleixo, Poliana Carolina; Junior, Dario Santos; Tomazelli, Andrea Cristina; Rufini, Iolanda A.; Berndt, Harald; Krug, Francisco Jose

    2004-01-01

    A simple method for cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry (BIFF-AAS) was proposed. Food slurries were prepared by transferring an exact amount of cryogenic-ground homogenized material (50-100 mg) to centrifuge tubes, followed by addition of 5 ml (up to 2.8 mol l -1 ) nitric acid solution and sonication in an ultrasonic bath during 5-10 min. Thereafter, slurries were diluted with water to 10 ml, centrifuged during 5 min at 5400 rpm and 400 μl aliquot of the supernatant was analyzed by BIFF-AAS. The detection limits based on peak height measurements were 0.03 μg g -1 Cd and 1.6 μg g -1 Pb for 2% (m/v) slurry (200 mg/10 ml). For method validation, the certified reference materials Pig Kidney (BCR 186) and Rice Flour (NIES 10) were used. Quantitative cadmium and lead recoveries were obtained and no statistical differences were found at 95% level by applying the t-test

  17. Direct determination of Cu, Mn, Pb, and Zn in beer by thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Nascentes, Clesia C.; Kamogawa, Marcos Y.; Fernandes, Kelly G.; Arruda, Marco A.Z.; Nogueira, Ana Rita A.; Nobrega, Joaquim A.

    2005-01-01

    In this work, thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was employed for Cu, Mn, Pb, and Zn determination in beer without any sample digestion. The system was optimized and calibration was based on the analyte addition technique. A sample volume of 300 μl was introduced into the hot Ni tube at a flow-rate of 0.4 ml min -1 using 0.14 mol l -1 nitric acid solution or air as carrier. Different Brazilian beers were directly analyzed after ultrasonic degasification. Results were compared with those obtained by graphite furnace atomic absorption spectrometry (GFAAS). The detection limits obtained for Cu, Mn, Pb, and Zn in aqueous solution were 2.2, 18, 1.6, and 0.9 μg l -1 , respectively. The relative standard deviations varied from 2.7% to 7.3% (n=8) for solutions containing the analytes in the 25-50 μg l -1 range. The concentration ranges obtained for analytes in beer samples were: Cu: 38.0-155 μg l -1 ; Mn: 110-348 μg l -1 , Pb: 13.0-32.9 μg l -1 , and Zn: 52.7-226 μg l -1 . Results obtained by TS-FF-AAS and GFAAS were in agreement at a 95% confidence level. The proposed method is fast and simple, since sample digestion is not required and sensitivity can be improved without using expensive devices. The TS-FF-AAS presented suitable sensitivity for determination of Cu, Mn, Pb, and Zn in the quality control of a brewery

  18. Laser driven source of spin polarized atomic deuterium and hydrogen

    International Nuclear Information System (INIS)

    Poelker, M.; Coulter, K.P.; Holt, R.J.

    1993-01-01

    Optical pumping of potassium atoms in the presence of a high magnetic field followed by spin exchange collisions with deuterium (hydrogen) is shown to yield a high flux of spin polarized atomic deuterium (hydrogen). The performance of the laser driven source has been characterized as a function of deuterium (hydrogen) flow rate, potassium density, pump laser power, and magnetic field. Under appropriate conditions, the authors have observed deuterium atomic polarization as high as 75% at a flow rate 4.2x10 17 atoms/second. Preliminary results suggest that high nuclear polarizations are obtained in the absence of weak field rf transitions as a result of a spin temperature distribution that evolves through frequent H-H (D-D) collisions

  19. Application of ECR ion source beams in atomic physics

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, F.W.

    1987-01-01

    The availability of intense, high charge state ion beams from ECR ion sources has had significant impact not only on the upgrading of cyclotron and synchrotron facilities, but also on multicharged ion collision research, as evidenced by the increasing number of ECR source facilities used at least on a part time basis for atomic physics research. In this paper one such facility, located at the ORNL ECR source, and dedicated full time to the study of multicharged ion collisions, is described. Examples of applications of ECR ion source beams are given, based on multicharged ion collision physics studies performed at Oak Ridge over the last few years. 21 refs., 18 figs., 2 tabs.

  20. A double-stage pulsed discharge fluorine atom beam source

    International Nuclear Information System (INIS)

    Ren Zefeng; Qiu Minghui; Che Li; Dai Dongxu; Wang Xiuyan; Yang Xueming

    2006-01-01

    Molecular-beam intensity and speed ratio are two major limiting factors in many molecular-beam experiments. This article reports a high-intensity, high-speed-ratio, pulsed supersonic fluorine atom beam source using a double-stage discharge beam source. Its performance is indicated by the high-resolution time-of-flight spectrum in the crossed beam experiment of F( 2 P)+para-H 2

  1. Optimization of atomic beam sources for polarization experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gaisser, Martin; Nass, Alexander; Stroeher, Hans [IKP, Forschungszentrum Juelich (Germany)

    2013-07-01

    For experiments with spin-polarized protons and neutrons a dense target is required. In current atomic beam sources an atomic hydrogen or deuterium beam is expanded through a cold nozzle and a system of sextupole magnets and RF-transition units selects a certain hyperfine state. The achievable flux seems to be limited to about 10{sup 17} particles per second with a high nuclear polarization. A lot of experimental and theoretical effort has been undertaken to understand all effects and to increase the flux. However, improvements have remained marginal. Now, a Monte Carlo simulation based on the DSMC part of the open source C++ library OpenFOAM is set up in order to get a better understanding of the flow and to optimize the various elements. It is intended to include important effects like deflection from magnetic fields, recombination on the walls and spin exchange collisions in the simulation and make quantitative predictions of changes in the experimental setup. The goal is to get a tool that helps to further increase the output of an atomic beam source. So far, a new binary collision model, magnetic fields, RF-transition units and a tool to measure the collision age are included. The next step will be to couple the whole simulation with an optimization algorithm implementing Adaptive Simulated Annealing (ASA) in order to automatically optimize the atomic beam source.

  2. Determination of total antimony and inorganic antimony species by hydride generation in situ trapping flame atomic absorption spectrometry: a new way to (ultra)trace speciation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Henryk Matusiewicz; Magdalena Krawczyk

    2008-07-01

    The analytical performance of non-chromatographic coupled hydride generation, integrated atom trap (HG-IAT) atomizer flame absorption spectrometry (FAAS) systems were evaluated for the speciation analysis of antimony in environmental samples. Antimony, using formation of stibine (SbH{sub 3}) vapors were atomized in an air-acetylene flame-heated IAT. A new design of HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangements was investigated. For the estimation of Sb(III) and Sb(V) concentrations in samples, the difference between the analytical sensitivities of the absorbance signals obtained for antimony hydride without and with previous treatment of samples with L-cysteine can be used. The concentration of Sb(V) was calculated by the difference between total Sb and Sb(III). A dramatic improvement in detection limit was achieved compared with that obtained using either of the atom trapping techniques, presented above, separately. This novel approach decreases the detection limit down to low pg mL{sup -1} levels. The concentration detection limit, defined as 3 times the blank standard deviation was 0.2 ng mL{sup -1}. For a 120 s in situ pre-concentration time , sensitivity enhancement compared to flame AAS, was 550 fold for Sb, using hydride generation-atom trapping technique. The accuracy of the method was verified by the use of certified reference materials (NIST SRM 2704 Buffalo River Sediment, SRM 2710 Montana Soil, SRM 1633a Coal Fly Ash, SRM 1575 Pine Needles, SRM 1643e Trace Elements in Water) and by aqueous standard calibration technique. The measured Sb content, in reference materials, were in satisfactory agreement with the certified values. The hyphenated technique was applied for antimony determinations in soil, sediment, coal fly ash, sewage and river water.

  3. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Science.gov (United States)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L- 1 HNO3 solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L- 1 and 36.4 mg L- 1, respectively. The repeatability of the results expressed as relative standard deviation was typically beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93-105% with the repeatability in the range of 4.1-5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg- 1), egg white (2188 ± 29 mg kg- 1), mineral water (31.0 ± 0.9 mg L- 1), white wine (260 ± 4 mg L- 1) and red wine (82 ± 2 mg L- 1), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L- 1).

  4. PHARAO space atomic clock: new developments on the laser source

    Science.gov (United States)

    Saccoccio, Muriel; Loesel, Jacques; Coatantiec, Claude; Simon, Eric; Laurent, Philippe; Lemonde, Pierre; Maksimovic, I.; Abgrall, M.

    2017-11-01

    The PHARAO project purpose is to open the way for a new atomic clock generation in space, where laser cooling techniques and microgravity allow high frequency stability and accuracy. The French space agency, CNES is funding and managing the clock construction. The French SYRTE and LKB laboratories are scientific and technical advisers for the clock requirements and the follow-up of subsystem development in industrial companies. EADS SODERN is developing two main subsystems of the PHARAO clock: the Laser Source and the Cesium Tube where atoms are cooled, launched, selected and detected by laser beams. The Laser Source includes an optical bench and electronic devices to generate the laser beams required. This paper describes PHARAO and the role laser beams play in its principle of operation. Then we present the Laser Source design, the technologies involved, and the status of development. Lastly, we focus of a key equipment to reach the performances expected, which is the Extended Cavity Laser Diode.

  5. Tailoring of materials by atomic oxygen from ECR plasma source

    International Nuclear Information System (INIS)

    Naddaf, Munzer; Bhoraskar, S.V.

    2002-01-01

    Full text: An intense source of oxygen finds important applications in many areas of science, technology and industry. It has been successfully used for surface activation and cleaning in the electronic, chemical and automotive industries. Atomic oxygen and interaction with materials have also a significant importance in space science and technology. This paper describes the detailed studies related to the surface modification and processing of different materials, which include metals and polymers by atomic oxygen produced in microwave assisted electron cyclotron resonance plasma. The energy distribution of ions was measured as a function of plasma parameters and density measurements were supplemented by catalytic probe using nickel and oxidation of silver surface

  6. Preconcentration of gold ions from water samples by modified organo-nanoclay sorbent prior to flame atomic absorption spectrometry determination

    Energy Technology Data Exchange (ETDEWEB)

    Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com [Nanochemistry Department, Research Institute of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman (Iran, Islamic Republic of); Mostafavi, Ali [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mirzaei, Mohammad [Nanochemistry Department, Research Institute of Environmental Sciences, International Center for Science, High Technology and Environmental Sciences, Kerman (Iran, Islamic Republic of); Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2010-09-15

    In this work, the applicability of modified organo nanoclay as a new and easy prepared solid sorbent for the preconcentration of trace amounts of Au(III) ion from water samples is studied. The organo nanoclay was modified with 5-(4'-dimethylamino benzyliden)-rhodanine and used as a sorbent for separation of Au(III) ions. The sorption of gold ions was quantitative in the pH range of 2.0-6.0. Quantitative desorption occurred with 6.0 mL of 1.0 mol L{sup -1} Na{sub 2}S{sub 2}O{sub 3}. The amount of eluted Au(III) was measured using flame atomic absorption spectrometry. In the initial solution the linear dynamic range was in the range of 0.45 ng mL{sup -1} to 10.0 {mu}g mL{sup -1}, the detection limit was 0.1 ng mL{sup -1} and the preconcentration factor was 105. Also, the relative standard deviation was {+-}2.3% (n = 8 and C = 2.0 {mu}g mL{sup -1}) and the maximum capacity of the sorbent was 3.9 mg of Au(III) per gram of modified organo nanoclay. The influences of the experimental parameters including sample pH, eluent volume and eluent type, sample volume, and interference of some ions on the recoveries of the gold ion were investigated. The proposed method was applied for preconcentration and determination of gold in different samples.

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

    Science.gov (United States)

    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.

  8. Optimization of atomic beam sources for polarization experiments

    Energy Technology Data Exchange (ETDEWEB)

    Gaisser, Martin; Nass, Alexander; Stroeher, Hans [IKP, Forschungszentrum Juelich (Germany)

    2012-07-01

    For experiments with spinpolarized protons and neutrons a dense target is required. In current atomic beam sources an atomic hydrogen or deuterium beam is expanded through a cold nozzle and a system of sextupole magnets and RF-transition units selects a certain hyperfine state. The achievable flux seems to be limited to about 10{sup 17} particles per second with a high nuclear polarization. A lot of experimental and theoretical effort has been undertaken to understand all effects and to increase the flux. However, improvements have remained marginal. Now, a Monte Carlo simulation based on the DSMC part of the open source C++ library OpenFOAM is set up in order to get a better understanding of the flow and to optimize the various elements. The goal is to include important effects like deflection from a magnetic field, recombination on the walls and spin exchange collisions in the simulation and make quantitative predictions of changes in the experimental setup. The goal is to get a tool that helps to further increase the output of an atomic beam source.

  9. Localizing gravitational wave sources with single-baseline atom interferometers

    Science.gov (United States)

    Graham, Peter W.; Jung, Sunghoon

    2018-02-01

    Localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. We show that the midfrequency band, roughly 0.03 to 10 Hz, has significant potential for angular localization. The angular location is measured through the changing Doppler shift as the detector orbits the Sun. This band maximizes the effect since these are the highest frequencies in which sources live for several months. Atom interferometer detectors can observe in the midfrequency band, and even with just a single baseline they can exploit this effect for sensitive angular localization. The single-baseline orbits around the Earth and the Sun, causing it to reorient and change position significantly during the lifetime of the source, and making it similar to having multiple baselines/detectors. For example, atomic detectors could predict the location of upcoming black hole or neutron star merger events with sufficient accuracy to allow optical and other electromagnetic telescopes to observe these events simultaneously. Thus, midband atomic detectors are complementary to other gravitational wave detectors and will help complete the observation of a broad range of the gravitational spectrum.

  10. Determination of sulfur in food by high resolution continuum source flame molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zambrzycka, Elżbieta; Godlewska-Żyłkiewicz, Beata, E-mail: bgodlew@uwb.edu.pl

    2014-11-01

    In the present work, a fast, simple and sensitive analytical method for determination of sulfur in food and beverages by high resolution continuum source flame molecular absorption spectrometry was developed. The determination was performed via molecular absorption of carbon monosulfide, CS. Different CS rotational lines (257.959 nm, 258.033 nm, 258.055 nm), number of pixels and types of standard solution of sulfur, namely: sulfuric acid, sodium sulfate, ammonium sulfate, sodium sulfite, sodium sulfide, DL-cysteine, and L-cystine, were studied in terms of sensitivity, repeatability of results as well as limit of detection and limit of quantification. The best results were obtained for measurements of absorption of the CS molecule at 258.055 nm at the wavelength range covering 3 pixels and DL-cysteine in 0.2 mol L{sup −1} HNO{sub 3} solution as a calibration standard. Under optimized conditions the limit of detection and the limit of quantification achieved for sulfur were 10.9 mg L{sup −1} and 36.4 mg L{sup −1}, respectively. The repeatability of the results expressed as relative standard deviation was typically < 5%. The accuracy of the method was tested by analysis of digested biological certified reference materials (soya bean flour, corn flour and herbs) and recovery experiment for beverage samples with added known amount of sulfur standard. The recovery of analyte from such samples was in the range of 93–105% with the repeatability in the range of 4.1–5.0%. The developed method was applied for the determination of sulfur in milk (194 ± 10 mg kg{sup −1}), egg white (2188 ± 29 mg kg{sup −1}), mineral water (31.0 ± 0.9 mg L{sup −1}), white wine (260 ± 4 mg L{sup −1}) and red wine (82 ± 2 mg L{sup −1}), as well as in sample rich in ions, such as bitter mineral water (6900 ± 100 mg L{sup −1}). - Highlights: • HR-CS FMAS technique was used for sulfur measurement via molecular absorption of carbon monosulfide, CS. • Organic DL

  11. Ionic liquid ultrasound assisted dispersive liquid-liquid microextraction method for preconcentration of trace amounts of rhodium prior to flame atomic absorption spectrometry determination

    Energy Technology Data Exchange (ETDEWEB)

    Molaakbari, Elaheh [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Young Research Society, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Mostafavi, Ali, E-mail: mostafavi.ali@gmail.com [Chemistry Department, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Afzali, Daryoush [Environment and Nanochemistry Department, Research Institute of Environmental Science, International Center for Science, High Technology and Environmental Science, Kerman (Iran, Islamic Republic of); Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of)

    2011-01-30

    In this article, we consider ionic liquid based ultrasound-assisted dispersive liquid-liquid microextraction of trace amounts of rhodium from aqueous samples and show that this is a fast and reliable sample pre-treatment for the determination of rhodium ions by flame atomic absorption spectrometry. The Rh(III) was transferred into its complex with 2-(5-bromo-2-pyridylazo)-5-diethylamino phenol as a chelating agent, and an ultrasonic bath with the ionic liquid, 1-octyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide at room temperature was used to extract the analyte. The centrifuged rhodium complex was then enriched in the form of ionic liquid droplets and prior to its analysis by flame atomic absorption spectrometry, 300 {mu}L ethanol was added to the ionic liquid-rich phase. Finally, the influence of various parameters on the recovery of Rh(III) was optimized. Under optimum conditions, the calibration graph was linear in the range of 4.0-500.0 ng mL{sup -1}, the detection limit was 0.37 ng mL{sup -1} (3S{sub b}/m, n = 7) and the relative standard deviation was {+-}1.63% (n = 7, C = 200 ng mL{sup -1}). The results show that ionic liquid based ultrasound assisted dispersive liquid-liquid microextraction, combined with flame atomic absorption spectrometry, is a rapid, simple, sensitive and efficient analytical method for the separation and determination of trace amounts of Rh(III) ions with minimum organic solvent consumption.

  12. Rapid determination of main components by means of flame-atomic-absorption spectrometry for chromium, silicon and tungsten in CrSiW materials

    International Nuclear Information System (INIS)

    Mueller, E.; Stahlberg, R.

    1985-01-01

    The application of Flame-Atomic-Absorption Spectrometry (FAAS) for determining chromium, silicon and tungsten in CrSiW materials is described. The FAAS determinations of the main components are shown under optimum conditions. Sufficient precision and reliability have been achieved for routine analysis. The application of a mixture of acids for preparing CrSiW solutions is proposed. The preparation of samples is discussed in detail. Optimum conditions are recommended for determining chromium, silicon and tungsten using one solution only. (orig.) [de

  13. Atomic physics at the Advanced Photon Source: Workshop report

    International Nuclear Information System (INIS)

    1990-10-01

    The first Workshop on Atomic Physics at the Advanced Photon Source was held at Argonne National Laboratory on March 29--30, 1990. The unprecedented brightness of the Advanced Photon Source (APS) in the hard X-ray region is expected to make possible a vast array of new research opportunities for the atomic-physics community. Starting with discussions of the history and current status of the field, presentations were made on various future directions for research with hard X-rays interacting with atoms, ions, clusters, and solids. Also important were the discussions on the design and status of the four next-generation rings coming on line during the 1990's: the ALS 1.6 GeV ring at Berkeley; the ESRF 6.0-GeV ring at Grenoble (1993); the APS 7.0-GeV ring at Argonne (1995); and the SPring-8 8.0-GeV ring in Japan (1998). The participation of more than one hundred scientists from domestic as well as foreign institutions demonstrated a strong interest in this field. We plan to organize follow-up workshops in the future emphasizing specific research topics

  14. Environmental concentration and atmospheric deposition of halogenated flame retardants in soil from Nepal: Source apportionment and soil-air partitioning.

    Science.gov (United States)

    Yadav, Ishwar Chandra; Devi, Ningombam Linthoingambi; Li, Jun; Zhang, Gan

    2018-02-01

    While various investigations have been driven on polybrominated diphenyl ethers (PBDEs) and other flame retardants (FRs) in different framework around the world, information about contamination and fate of PBDEs and other FRs in developing countries especially in the Indian subcontinent is uncommon. Nepal being located in the Indian subcontinent, very little is known about contamination level of semi-volatile organic pollutants discharged into the environment. This motivated us to investigate the environmental fate of halogenated flame retardant (HFRs) in Nepalese condition. In this study, we investigated the concentration, fate, and sources of 9 PBDEs, 2 dechlorane plus isomers (DPs), and 6 novel brominated flame retardants (NBFRs). Moreover, air-soil exchange and soil-air partitioning were also evaluated to characterize the pattern of air-soil exchange and environmental fate. In general, the concentrations of NBFRs in soil were more prevalent than PBDEs and DPs, and accounted 95% of ∑HFRs. By and large, the concentrations of NBFRs and DPs were measured high in Kathmandu, while PBDEs level exceeded in Pokhara. Principal component analysis (PCA) study suggested contributions from commercial penta-, octa-, and deca-BDEs products and de-bromination of highly brominated PBDEs as the significant source of PBDEs. Likewise, low f anti ratio suggested DPs in soil might have originated from long-range atmospheric transport from remote areas, while high levels of decabromodiphenyl ethane (DBDPE) in soil were linked with the use of wide varieties of consumer products. The estimated fugacity fraction (ff) for individual HFR was quite lower (soil is overwhelming. Soil-air partitioning study revealed neither octanol-air partition coefficient (K OA ) nor black carbon partition coefficient (K BC-A ) is an appropriate surrogate for soil organic matter (SOM), subsequently, absorption by SOM has no or little role in the partitioning of HFRs. Copyright © 2017 Elsevier Ltd. All

  15. The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

    Energy Technology Data Exchange (ETDEWEB)

    Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

  16. The atomization and the flame structure in the combustion of residual fuel oils; La atomizacion y estructura de flama en la combustion de combustibles residuales

    Energy Technology Data Exchange (ETDEWEB)

    Bolado Estandia, Ramon [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1985-12-31

    In this article a research on the combustion of heavy residual fuel oils is presented. The type of flames studied were obtained by means of the burning of sprays produced by an atomizer designed and calibrated specially for the research purpose. The flame characteristics that were analyzed are its length, its luminosity, the temperature, the distribution of the droplets size and mainly the burning regime of the droplets in the flame. The experimental techniques that were used for these studies were shadow micro-photography, suction pyrometry and of total radiation, laser diffraction, 35 mm photography, and impact push. The analysis of the experimental results, together with the results of the application of a mathematical model, permitted to establish two parameters, that quantitatively related determine the burning regime of the droplets in a flame of sprays of residual heavy fuel oil. [Espanol] En este articulo se presenta una investigacion sobre la combustion de combustibles residuales pesados. El tipo de flamas estudiadas se obtuvieron mediante el quemado de sprays producidos por un atomizador disenado y calibrado especialmente para el proposito de la investigacion. Las caracteristicas de flama que se analizaron son la longitud, la luminosidad, la temperatura, la distribucion de tamano de gotas y, principalmente, el regimen de quemado de gotas en la flama. Las tecnicas experimentales que se usaron para estos estudios fueron microfotografia de sombras, pirometria de succion y de radiacion total, difraccion laser, fotografia de 35 mm y empuje de impacto. El analisis de resultados experimentales, junto con los resultados de la aplicacion de un modelo matematico, permitio establecer dos parametros, que relacionados cuantitativamente, determinan el regimen de quemado de gotas en una flama de sprays de combustible residual pesado.

  17. Coupling continuous ultrasound-assisted extraction, preconcentration and flame atomic absorption spectrometric detection for the determination of cadmium and lead in mussel samples

    International Nuclear Information System (INIS)

    Yebra-Biurrun, M.C.; Cancela-Perez, S.; Moreno-Cid-Barinaga, A.

    2005-01-01

    Continuous ultrasound-assisted extraction has been coupled with preconcentration and flame atomic absorption spectrometry for the determination of cadmium and lead in mussel samples. Experimental designs were used for the optimisation of the leaching and preconcentration steps. The use of diluted nitric acid as extractant in the continuous mode at a flow rate of 3.5 ml min -1 and room temperature was sufficient for quantitative extraction of these trace metals. A minicolumn containing a chelating resin (Chelite P, with aminomethylphosphoric acid groups) was proved as an excellent material for the quantitative preconcentration of cadmium and lead prior to their flame atomic absorption detection. A flow injection manifold was used as interface for coupling the three analytical steps, which allowed the automation of the whole analytical process. A good precision of the whole procedure (2.0 and 2.3%), high enrichment factors (20.5 and 11.8) and a detection limit of 0.011 and 0.25 μg g -1 for cadmium and lead, respectively, were obtained for 80 mg of sample. The sample throughputs were ca. 16 and 14 samples h -1 for cadmium and lead, respectively. The accuracy of the analytical procedures was verified by using a standard reference material (BCR 278-R, mussel tissue) and the results were in good agreement with the certified values. The method was successfully applied to the determination of trace amounts of cadmium and lead in mussel samples from the coast of Galicia (NW, Spain)

  18. Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: A multivariate study

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem G.; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

    2014-12-01

    An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu2+) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu2+ using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046 μg L-1 and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu2+ in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu2+ in serum samples of different viral hepatitis patients and healthy controls.

  19. Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: a multivariate study.

    Science.gov (United States)

    Arain, Salma Aslam; Kazi, Tasneem G; Afridi, Hassan Imran; Abbasi, Abdul Rasool; Panhwar, Abdul Haleem; Naeemullah; Shanker, Bhawani; Arain, Mohammad Balal

    2014-12-10

    An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu(2+)) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu(2+) using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046μgL(-1) and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu(2+) in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu(2+) in serum samples of different viral hepatitis patients and healthy controls. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Design and performance of a high intensity copper atom beam source nozzle for use in inelastic atom--atom collision experiments

    International Nuclear Information System (INIS)

    Santavicca, D.A.

    1975-01-01

    The research was aimed at developing a neutral copper atom beam source which could be used to study the collision cross sections for electronic excitation of neutral copper atoms in collision with neutral argon atoms. Of particular interest is the excitation from the ground state to the two upper laser levels at 3.80 and 3.82 electron volts

  1. Characterization of atomic oxygen from an ECR plasma source

    International Nuclear Information System (INIS)

    Naddaf, M; Bhoraskar, V N; Mandale, A B; Sainkar, S R; Bhoraskar, S V

    2002-01-01

    A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from ∼1x10 20 to ∼10x10 20 atom m -3 as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe

  2. Characterization of atomic oxygen from an ECR plasma source

    Science.gov (United States)

    Naddaf, M.; Bhoraskar, V. N.; Mandale, A. B.; Sainkar, S. R.; Bhoraskar, S. V.

    2002-11-01

    A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from ~1×1020 to ~10×1020 atom m-3 as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe.

  3. Characterization of atomic oxygen from an ECR plasma source

    Energy Technology Data Exchange (ETDEWEB)

    Naddaf, M [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India); Bhoraskar, V N [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India); Mandale, A B [National Chemical Laboratory, Pashan, Pune 411008 (India); Sainkar, S R [National Chemical Laboratory, Pashan, Pune 411008 (India); Bhoraskar, S V [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India)

    2002-11-01

    A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from {approx}1x10{sup 20} to {approx}10x10{sup 20} atom m{sup -3} as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe.

  4. A rapid method for determining tin and molybdenum in geological samples by flame atomic-absorption spectroscopy

    Science.gov (United States)

    Welsch, E.P.

    1985-01-01

    The proposed method uses a lithium metaborate fusion, dissolution of the fusion bead in 15% v v hydrochloric acid, extraction into a 4% solution of trioctylphosphine oxide in methyl isobutyl ketone, and aspiration into a nitrous oxide-acetylene flame. The limits of detection for tin and molybdenum are 1.0 and 0.5 ppm, respectively. Approximately 50 samples can be analysed per day. ?? 1985.

  5. Finite Element Modelling of a Pattern of Temperature Distribution during Travelling Heat Source from Oxyacetylene Flame

    Directory of Open Access Journals (Sweden)

    Alkali Adam Umar

    2014-07-01

    Full Text Available A 3D Finite element model was developed to analyse the conduction temperature distribution on type 304 stainless steel workpiece. An experimental heating-only test was conducted using the input parameters from FEM model which predicted the temperature field on the 304 stainless steel work pieces. Similar temperature pattern was noticed for both the FEM model as well as the experimental. Conduction was observed to be the dominant heat transfer mode. Maximum temperatures were observed to occur at the regions of contact between flame heat and the work pieces. Maximum temperature attained during the two investigated runs was 355°C. Even so austenite crystal morphology was retained on the preheated workpiece.

  6. ENERGETIC NEUTRAL ATOMS: AN ADDITIONAL SOURCE FOR HELIOSPHERIC PICKUP IONS

    International Nuclear Information System (INIS)

    Bochsler, Peter; Moebius, Eberhard

    2010-01-01

    Recently, Schwadron and McComas discussed the possibility of inner source pickup particles originating from the ionization of energetic neutral atoms (ENAs), based on new data from the IBEX mission. This proposition has some interesting features, namely, it might be able to explain why inner source pickup ions (PUIs) have a composition resembling solar abundances and show no indication of overabundance of refractory elements, although this should be expected, if the conventional explanation of solar wind-dust interaction for the origin of this heliospheric component were correct. In this Letter, we explore further consequences for ENA-related PUIs and investigate their velocity distributions. We conclude that this model will not reproduce the observed velocity distributions of inner source PUIs and point out a substantial deviation in their composition. However, it seems likely that the ionization of ENAs as observed with IBEX could contribute a significant amount of heliospheric suprathermal tail ions. Some possible consequences of our investigation for heliospheric particle populations are briefly discussed.

  7. Creation and recovery of a W(111) single atom gas field ion source

    International Nuclear Information System (INIS)

    Pitters, Jason L.; Urban, Radovan; Wolkow, Robert A.

    2012-01-01

    Tungsten single atom tips have been prepared from a single crystal W(111) oriented wire using the chemical assisted field evaporation and etching method. Etching to a single atom tip occurs through a symmetric structure and leads to a predictable last atom unlike etching with polycrystalline tips. The single atom tip formation procedure is shown in an atom by atom removal process. Rebuilds of single atom tips occur on the same crystalline axis as the original tip such that ion emission emanates along a fixed direction for all tip rebuilds. This preparation method could be utilized and developed to prepare single atom tips for ion source development.

  8. Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of cyanide using cadmium carbonate as a new solid-phase reactor

    International Nuclear Information System (INIS)

    Noroozifar, M.; Khorasani-Motlagh, M.; Hosseini, S.-N.

    2005-01-01

    A new and simple flow injection system procedure has been developed for the indirect determination of cyanide. The method is based on insertion of aqueous cyanide solutions into an on-line cadmium carbonate packed column (25% m/m suspended on silica gel beads) and a sodium hydroxide with pH 10 is used as the carrier stream. The eluent containing the analyte as cadmiumcyanide complexes, produced from reaction between cadmium carbonate and cyanide, measured by flame atomic absorption spectrometry. The absorbance is proportional to the concentration of cyanide in the sample. The linear range of the system is up to 15 mg L -1 with a detection limit 0.2 mg L -1 and sampling rate 72 h -1 . The method is suitable for determination of cyanide in industrial waste waters with a relative standard deviation better than 1.22%

  9. Separation/preconcentration of silver(I) and lead(II) in environmental samples on cellulose nitrate membrane filter prior to their flame atomic absorption spectrometric determinations

    International Nuclear Information System (INIS)

    Soylak, Mustafa; Cay, Rukiye Sungur

    2007-01-01

    An enrichment method for trace amounts of Ag(I) and Pb(II) has been established prior to their flame atomic absorption spectrometric determinations. The preconcentration/separation procedure is based on chelate formation of Ag(I) and Pb(II) with ammonium pyrrolidine dithiocarbamate (APDC) and on retention of the chelates on cellulose nitrate membrane filter. The influences of some analytical parameters including pH and amounts of reagent, etc. on the recoveries of analytes were investigated. The effects of interferic ions on the quantitative recoveries of analytes were also examined. The detection limits (k = 3, N = 11) were 4.6 μg L -1 for silver(I) and 15.3 μg L -1 for lead(II). The relative standard deviations (R.S.D.) of the determinations for analyte ions were below 3%. The method was applied to environmental samples for the determination of analyte ions with satisfactory results (recoveries >95%)

  10. Optimization of microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Soylak, Mustafa; Tuzen, Mustafa; Souza, Anderson Santos; Korn, Maria das Gracas Andrade; Ferreira, Sergio Luis Costa

    2007-01-01

    The present paper describes the development of a microwave assisted digestion procedure for the determination of zinc, copper and nickel in tea samples employing flame atomic absorption spectrometry (FAAS). The optimization step was performed using a full factorial design (2 3 ) involving the factors: composition of the acid mixture (CMA), microwave power (MP) and radiation time (RT). The experiments of this factorial were carried out using a certified reference material of tea GBW 07605 furnished by National Research Centre for Certified Reference Materials, China, being the metal recoveries considered as response. The relative standard deviations of the method were found below 8% for the three elements. The procedure proposed was used for the determination of copper, zinc and nickel in several samples of tea from Turkey. For 10 tea samples analyzed, the concentration achieved for copper, zinc and nickel varied at 6.4-13.1, 7.0-16.5 and 3.1-5.7 (μg g -1 ), respectively

  11. Flame atomic absorption spectrometric determination of trace quantities of cadmium in water samples after cloud point extraction in Triton X-114 without added chelating agents

    International Nuclear Information System (INIS)

    Afkhami, Abbas; Madrakian, Tayyebeh; Siampour, Hajar

    2006-01-01

    A new micell-mediated phase separation method for preconcentration of ultra-trace quantities of cadmium as a prior step to its determination by flame atomic absorption spectrometry has been developed. The method is based on the cloud point extraction (CPE) of cadmium in iodide media with Triton X-114 in the absence of any chelating agent. The optimal extraction and reaction conditions (e.g., acid concentration, iodide concentration, effect of time) were studied, and the analytical characteristics of the method (e.g., limit of detection, linear range, preconcentration, and improvement factors) were obtained. Linearity was obeyed in the range of 3-300 ng mL -1 of cadmium. The detection limit of the method is 1.0 ng mL -1 of cadmium. The interference effect of some anions and cations was also tested. The method was applied to the determination of cadmium in tap water, waste water, and sea water samples

  12. Separation/preconcentration of trace Pb(II and Cd(II with 2-mercaptobenzothiazole impregnated Amberlite XAD-1180 resin and their determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Şerife Tokalıoğlu

    2017-01-01

    Full Text Available A new chelating resin, 2-mercaptobenzothiazole loaded Amberlite XAD-1180 was prepared and used for separation and preconcentration of Cd(II and Pb(II ions prior to their determinations by flame atomic absorption spectrometry. The optimum pH for simultaneous retention of the elements and the best elution means for their simultaneous elution were 9.5 and 2 mol L−1 HNO3, respectively. The detection limits for Cd(II and Pb(II were 0.35 and 5.0 μg L−1, respectively. The accuracy of the method was confırmed both by analyzing the certified reference material (RM 8704 Buffalo river sediment and performing recovery studies.

  13. Preconcentration, Separation and Determination of lead(II) with Methyl Thymol Blue Adsorbed on Activated Carbon Using Flame Atomic Absorption Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ensafi, Ali A.; Ghaderi, Ali R. [Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2008-02-15

    An on-line system for preconcentration and separation of lead(II) is presented. The method is based on the complex formation of Pb(II) with adsorbed Methyl thymol blue on activated carbon. The conditions of preparing the solid phase reagent and of quantitative recovery of Pb(II) from diluted solutions, such as acidity of aqueous phase, solid phase capacity, and flow variables were studied as well as effect of potential interfering ions. After preconcentration step, the metal ions are eluted automatically by 5 ml of 0.5 M HNO{sub 3} solution and the lead ions content was determined by flame atomic absorption spectrometry. Under the optimum conditions, the lead ions in aqueous samples were separated and preconcentrated about 1000-fold by the column. The detection limit was 0.001 μg mL{sup -1}. Lead has been determined in river and tap water samples, with recovery of 98 to 102%.

  14. Solvent microextraction-flame atomic absorption spectrometry (SME-FAAS) for determination of ultratrace amounts of cadmium in meat and fish samples.

    Science.gov (United States)

    Goudarzi, Nasser

    2009-02-11

    A simple, low cost and highly sensitive method based on solvent microextraction (SME) for separation/preconcentration and flame atomic absorption spectrometry (FAAS) was proposed for the determination of ultratrace amounts of cadmium in meat and fish samples. The analytical procedure involved the formation of a hydrophobic complex by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution. In suitable conditions, the complex of cadmium-APDC entered the micro organic phase, and thus, separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, a detection limit (3 sigma) of 0.8 ng L(-1) and an enrichment factor of 93 were achieved. The relative standard deviation for the method was found to be 2.2% for Cd. The interference effects of some anions and cations were also investigated. The developed method has been applied to the determination of trace Cd in meat and fish samples.

  15. Determination of lead associated with airborne particulate matter by flame atomic absorption and wave-length dispersive x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Talebi, S.M.

    1997-01-01

    The lead content of airborne particulate matter was determined by flame atomic absorption spectrometry (FAAS) following digestion with a mixture of nitric acid and hydrogen peroxide and also by wave-length dispersive x-ray fluorescence (WDXRF). The extraction procedure was checked by analyzing a standard reference material of airborne particulate matter (NIST, SRM -1648). It was concluded that lead can quantitatively (98%) be extracted from airborne particulate matter by the leaching process. A five-stage sequential extraction was performed to assess the potential mobility of lead associated with airborne particulate matter. Comparison of the airborne particulate lead measured by WDXRF to that measured by FAAS showed good agreement. The WDXRF method requires no time-consuming sample preparation or use of environmentally unfriendly solvents. The technique is suggested for direct determination of lead in airborne particulate matter in air pollution studies. (author)

  16. Product screening for sources of halogenated flame retardants in Canadian house and office dust

    International Nuclear Information System (INIS)

    Abbasi, Golnoush; Saini, Amandeep; Goosey, Emma; Diamond, Miriam L.

    2016-01-01

    Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing. - Highlights: • Concentrations of flame retardants in dust correlated with product surface wipes • Most abundant FRs in electronics were PBDEs, TDCPP, DBDPE, EH-TBB and BEHTBP. • Descending order of FRs in CRTs, TVs, PCs, A-V devices, and small household appliances • Product wipe testing, but not XRF, useful for non

  17. Product screening for sources of halogenated flame retardants in Canadian house and office dust

    Energy Technology Data Exchange (ETDEWEB)

    Abbasi, Golnoush [Department of Geography, University of Toronto, 100 St. George St., Toronto M5S 3G3 (Canada); Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4 (Canada); Goosey, Emma [Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1 (Canada); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, University of Toronto, 22 Russell Street, Toronto M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail, Toronto M1C 1A4 (Canada)

    2016-03-01

    Human exposure to halogenated flame retardants (HFRs) such as polybrominated diphenyl ethers (PBDEs) and their replacements, can be related to exposure to indoor dust and direct contact with HFR-containing products. This study aimed to identify electronic products that contributed to HFRs measured in indoor dust and to develop a screening method for identifying HFRs in hard polymer products. Concentrations of 10 PBDEs and 12 halogenated replacements in dust and surface wipe samples of hard polymer casings of electronic products plus Br in the surfaces of those casing measured using X-ray fluorescence (XRF) were analyzed from 35 homes and 10 offices in Toronto (ON, Canada). HFR concentrations in dust and product wipes were positively correlated. Thus, we hypothesize that electronic products with the highest HFR concentrations contribute the most to concentrations in dust, regardless of the volatility of the HFR. Abundant HFRs in dust and product wipes were PBDEs (BDE-47, 99, 100, 153, 154, 183, 209), TDCPP, DBDPE, EH-TBB and BEHTBP. Older CRT TVs had the highest concentration of BDE-209 of all products tested. This was followed by higher concentrations of HFRs in PCs, Audio/Video (A/V) devices, small household appliances (HHAs) and flat screen TVs. The removal of HFRs from polymer surfaces using wipes supports concerns that HFRs could be transferred from these surfaces to hands as a result of direct contact with HFR-containing products. Surface wipe testing shows promise for screening additive HFRs. In comparison, the Br-content obtained using a handheld XRF analyzer did not correspond to concentrations obtained from surface wipe testing. - Highlights: • Concentrations of flame retardants in dust correlated with product surface wipes • Most abundant FRs in electronics were PBDEs, TDCPP, DBDPE, EH-TBB and BEHTBP. • Descending order of FRs in CRTs, TVs, PCs, A-V devices, and small household appliances • Product wipe testing, but not XRF, useful for non

  18. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Acar, O.

    2012-07-01

    The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH{sub 4}H{sub 2}PO{sub 4} chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD) for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 {mu}g L{sup -}1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM) and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH{sub 4}H{sub 2}PO{sub 4} mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values. (Author) 48 refs.

  19. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Acar, O.

    2012-01-01

    The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH 4 H 2 PO 4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD) for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 μg L - 1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM) and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH 4 H 2 PO 4 mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values. (Author) 48 refs.

  20. Silica gel modified with N-(3-propyl)-O-phenylenediamine: functionalization, metal sorption equilibrium studies and application to metal enrichment prior to determination by flame atomic absorption spectrometry.

    Science.gov (United States)

    Akl, Magda Ali Abd-elAziz; Kenawy, Ibraheim Mohamed; Lasheen, Rabab Ramadan

    2005-08-01

    The use of the chemically modified silica gel N-(3-propyl)-O-phenylenediamine (SiG-NPPDA) adsorbent, for the preconcentration and separation of trace heavy metals, was described. SiG-NPPDA sorbs quantitatively (90-100% recovery) trace amounts of nine heavy metals, viz., Cd(II), Zn(II), Fe(III), Cu(II), Pb(II), Mn(II), Cr(III), Co(II) and Ni(II) at pH 7-8. The sorption capacity varies from 350 to 450 micromol g(-1). Desorption was found to be quantitative with 1-2 M HNO3 or 0.05 M Na2EDTA. The distribution coefficient, Kd and the percentage concentration of the investigated metal ions on the adsorbent at equilibrium, C(M,eqm)% (Recovery, R%), were studied as a function of experimental parameters. The logarithmic values of the distribution coefficient, log Kd, ranges between 4.0 and 6.4. Some foreign ions caused little interference in the preconcentration and determination of the investigated nine metals by flame atomic absorption spectrometry (AAS). The adsorbent and its formed metal chelates were characterized by IR (absorbance and/or reflectance), potentiometric titrations and thermogravimetric analysis (TGA and DTG). The mode of chelation between the SiG-NPPDA adsorbent and the investigated metal ions is proposed to be due to the reaction of the investigated metal ions with the two nitrogen atoms of the SiG-NPPDA adsorbent. The present adsorbent coupled with flame AAS has been used to enrich and determine the nine metal ions in natural aqueous systems and in certified reference materials (RSD < or = 5%). The copper, iron, manganese and zinc present in some pharmaceutical vitamin samples were also preconcentrated on SiG-NPPDA adsorbent and determined by flame AAS (RSD < or = 4.2%). Nanogram concentrations (0.07-0.14 ng ml(-1)) of Cd(II), Zn(II), Fe(III), Pb(II), Cr(III), Mn(II), Cu(II), Co(II) and Ni(II) can be determined reliably with a preconcentration factor of 100.

  1. Laser Source for Atomic Gravity Wave Detector Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atom Interferometry (AI) Technology for Gravity Wave Measurements demonstrates new matter wave Interferometric sensor technology for precise detection and...

  2. Preconcentration of Co, Ni, Cd and Zn on naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent and flame atomic absorption determination

    Directory of Open Access Journals (Sweden)

    TAYYEBEH MADRAKIAN

    2010-05-01

    Full Text Available A preconcentration method was developed for the determination of trace amounts of Co, Ni, Cd and Zn by atomic absorption spectrometry. The method is based on the retention of the metal cations by naphthalene–2,4,6-trimorpholino-1,3,5-triazin adsorbent in a column. The adsorbed metals were then eluted from the column with hydrochloric acid and the Co, Ni, Cd and Zn were determined by flame atomic absorption spectrometry. The optimal extraction and elution conditions were studied. The effects of diverse ions on the preconcentration were also investigated. A preconcentration factor of 250 for Co(II, Ni(II and Zn(II, and 400 for Cd(II can easily be achieved. Calibration graphs were obtained and the detection limits of the method for Co(II, Ni(II, Cd(II and Zn(II were 0.51, 0.49, 0.17 and 0.10 ng mL-1, respectively. The relative standard deviations (RSD of 0.37–2.31 % for Co, 0.37–3.73 % for Ni, 2.20–2.40 % for Cd and 1.50–2.56 % for Zn were obtained. The method was also used for the simultaneous preconcentration of these elements and the method was successfully applied to their preconcentration and determination. The method was applied to the determination of Co, Ni, Cd and Zn in several real samples.

  3. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    Science.gov (United States)

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Occurrence and source apportionment of halogenated flame retardants in the indoor air of Nepalese cities: Implication on human health

    Science.gov (United States)

    Yadav, Ishwar Chandra; Devi, Ningombam Linthoingmabi; Li, Jun; Zhang, Gan

    2017-07-01

    Elevated level of brominated- and chlorinated-flame retardants (FRs) have been accounted in ambient air across the globe. Despite what might be expected, restricted information is available on PBDEs and other halogenated FR contained indoor air in whole of Indian sub-continent especially in case of Nepal, sandwiched between two most populous countries i.e. India and China. It was conjectured that the level of halogenated flame retardant (HFRs) in Nepalese air would be high because they have not been liable to control in Nepal; and henceforth there is more plausibility of HFRs to be available in a diverse array of goods and consumer products. This study therefore aims to measure the occurrence, spatial distributions and sources of 15 brominated- and 2 chlorinated-FRs in indoor air from four major cities of Nepal. The overall concentrations of HFRs ranged from 16.1 to 6750 pg/m3 (median 334 pg/m3). The total concentrations of novel brominated fire retardants (NBFRs) were 20 and 100 times (13.2-6270 pg/m3) higher than PBDEs (2.2-353 pg/m3) and DPs (0.67-129 pg/m3), respectively indicating much higher usages of NBFRs in Nepal. The level of ∑PBDEs in air is identified with utilization of wide variety of consumers products and building materials containing FRs in Nepalese houses, while higher concentration of BDE-209 were subject to emission from materials containing deca-BDE formulation. Significantly higher concentrations of DBDPE than BDE-209 in air demonstrated a move to more prominent use of DBDPE as alternative to BDE-209. The lower fanti ratios suggests the DP level in this study was essentially affected by the long range atmospheric transport from remote DP source instead of commercial products. The exposure to BDE-47, -99, -153, -209 and HBB via inhalation was 3-4 orders of magnitude lower than corresponding RfD values, suggesting insignificant risk to Nepalese population. However, other modes of human exposure might still be significant in Nepal.

  5. Point source atom interferometry with a cloud of finite size

    Energy Technology Data Exchange (ETDEWEB)

    Hoth, Gregory W., E-mail: gregory.hoth@nist.gov; Pelle, Bruno; Riedl, Stefan; Kitching, John; Donley, Elizabeth A. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2016-08-15

    We demonstrate a two axis gyroscope by the use of light pulse atom interferometry with an expanding cloud of atoms in the regime where the cloud has expanded by 1.1–5 times its initial size during the interrogation. Rotations are measured by analyzing spatial fringe patterns in the atom population obtained by imaging the final cloud. The fringes arise from a correlation between an atom's initial velocity and its final position. This correlation is naturally created by the expansion of the cloud, but it also depends on the initial atomic distribution. We show that the frequency and contrast of these spatial fringes depend on the details of the initial distribution and develop an analytical model to explain this dependence. We also discuss several challenges that must be overcome to realize a high-performance gyroscope with this technique.

  6. Study of interferences in the atomic - absorption and emission of barium in nitrous oxide/acetylene flame

    International Nuclear Information System (INIS)

    Curtius, A.J.; Couto, M.I.

    1979-01-01

    The interferences of several ions that are present in oifield water and sea water in the atomic absorption and emission of barium were investigated. It was verified that the interferences of sodium, potassium, calcium, strontium and chloride are the most important. The indirect method for the determination of sulfate by measuring barium by atomic absorption after precipitating barium sulfate with an excess of barium chloride, should not be used for highly salted matrix. To avoid the interferences that are not compensated by an ionization supressor, the measurement of barium by the standard addition method or a previous sulfate separation is recommended. (Author) [pt

  7. Determination of total sulfur in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry.

    Science.gov (United States)

    Virgilio, Alex; Raposo, Jorge L; Cardoso, Arnaldo A; Nóbrega, Joaquim A; Gomes Neto, José A

    2011-03-23

    The usefulness of molecular absorption was investigated for the determination of total sulfur (S) in agricultural samples by high-resolution continuum source flame molecular absorption spectrometry. The lines for CS at 257.595, 257.958, and 258.056 nm and for SH at 323.658, 324.064, and 327.990 nm were evaluated. Figures of merit, such as linear dynamic range, sensitivity, linear correlation, characteristic concentration, limit of detection, and precision, were established. For selected CS lines, wavelength-integrated absorbance equivalent to 3 pixels, analytical curves in the 100-2500 mg L(-1) (257.595 nm), 250-2000 mg L(-1) (257.958 nm), and 250-5000 mg L(-1) (258.056 nm) ranges with a linear correlation coefficient better than 0.9980 were obtained. Results were in agreement at a 95% confidence level (paired t test) with those obtained by gravimetry. Recoveries of S in fungicide and fertilizer samples were within the 84-109% range, and the relative standard deviation (n=12) was typically <5%.

  8. Multi-channel tunable source for atomic sensors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR will establish the feasibility of developing compact, robust, integrated components suitable for atomic interferometry. AdvR's design is enabled by...

  9. In situ emulsification microextraction using a dicationic ionic liquid followed by magnetic assisted physisorption for determination of lead prior to micro-sampling flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Shokri, Masood; Beiraghi, Asadollah; Seidi, Shahram

    2015-01-01

    For the first time, a simple and efficient in situ emulsification microextraction method using a dicationic ionic liquid followed by magnetic assisted physisorption was presented to determine trace amounts of lead. In this method, 400 μL of 1.0 mol L −1 lithium bis (trifluoromethylsulfonyl) imide aqueous solution, Li[NTf 2 ], was added into the sample solution containing 100 μL of 1.0 mol L −1 1,3-(propyl-1,3-diyl) bis (3-methylimidazolium) chloride, [pbmim]Cl 2 , to form a water immiscible ionic liquid, [pbmim][NTf 2 ] 2 . This new in situ formed dicationic ionic liquid was applied as the acceptor phase to extract the lead-ammonium pyrrolidinedithiocarbamate (Pb-APDC) complexes from the sample solution. Subsequently, 30 mg of Fe 3 O 4 magnetic nanoparticles (MNPs) were added into the sample solution to collect the fine droplets of [pbmim][NTf 2 ] 2 , physisorptively. Finally, MNPs were eluted by acetonitrile, separated by an external magnetic field and the obtained eluent was subjected to micro-sampling flame atomic absorption spectrometry (FAAS) for further analysis. Comparing with other microextraction methods, no special devices and centrifugation step are required. Parameters influencing the extraction efficiency such as extraction time, pH, concentration of chelating agent, amount of MNPs and coexisting interferences were studied. Under the optimized conditions, this method showed high extraction recovery of 93% with low LOD of 0.7 μg L −1 . Good linearity was obtained in the range of 2.5–150 μg L −1 with determination coefficient (r 2 ) of 0.9921. Relative standard deviation (RSD%) for seven repeated measurements at the concentration of 10 μg L −1 was 4.1%. Finally, this method was successfully applied for determination of lead in some water and plant samples. - Highlights: • A dicationic ionic liquid was used as the extraction solvent, for the first time. • A simple and efficient in situ emulsification microextraction

  10. Modified mesoporous silica materials for on-line separation and preconcentration of hexavalent chromium using a microcolumn coupled with flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Wang Zheng, E-mail: wangzheng@mail.sic.ac.cn [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Fang Dongmei; Li Qing [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); East China University of Science and Technology, Shanghai 200237 (China); Zhang Lingxia; Qian Rong; Zhu Yan; Qu Haiyun [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Du Yiping [East China University of Science and Technology, Shanghai 200237 (China)

    2012-05-06

    Highlights: Black-Right-Pointing-Pointer A modified SBA-15 mesoporous silica material (NH{sub 2}-SBA-15) was synthesized as sorbent. Black-Right-Pointing-Pointer The material was used for the first time in a flow injection on-line solid phase extraction (SPE) coupled with flame atomic absorption spectrometry (FAAS) to detect trace Cr (VI). Black-Right-Pointing-Pointer The NH{sub 2}-SBA-15 enables retain Cr (VI) with an enrichment factor of 44. Black-Right-Pointing-Pointer The micro-column of NH{sub 2}-SBA-15 underwent more than 100 adsorption/desorption cycles. - Abstract: A modified SBA-15 mesoporous silica material NH{sub 2}-SBA-15 was synthesized successfully by grafting {gamma}-aminopropyl-triethoxysilane. The material was characterized using transmission electron microscopy (TEM) and Fourier transform infrared/Raman (FT-IR/Raman) spectroscopy, and used for the first time in a flow injection on-line solid phase extraction (SPE) coupled with flame atomic absorption spectrometry (FAAS) to detect trace Cr (VI). Effective sorption of Cr (VI) was achieved at pH 2.0 with no interference from Cr (III) and other ions and 0.5 mol L{sup -1} NH{sub 3}{center_dot}H{sub 2}O solution was found optimal for the complete elution of Cr (VI). An enrichment factor of 44 and was achieved under optimized experimental conditions at a sample loading of 2.0 mL min{sup -1} sample loading (300 s) and an elution flow rate of 2.0 mL min{sup -1} (24 s). The precision of the 11 replicate Cr (VI) measurements was 2.1% at the 100 {mu}g L{sup -1} level with a detection limit of 0.2 {mu}g L{sup -1} (3 s, n = 10) using the FAAS. The developed method was successfully applied to trace chromium determination in waste water. The accuracy was validated using a certified reference material of riverine water (GBW08607).

  11. Atomic absorption spectrophotometer

    International Nuclear Information System (INIS)

    Stockdale, T. J.

    1985-01-01

    In atomic absorption spectrophotometer, a reference path may be provided for radiation which excludes the flame. This radiation provides a signal from a detector which varies only with the instrumental drift produced by variations in the radiation source brightness and by variations in detector gain. The signal can be used to compensate for drift in other signals received through a sample path including the flame. In the present invention, radiation passes through the sample path continuously during measurement, and only through the reference path between sample measurements. Movable mirrors shift the radiation between the paths upon externally applied commands. Conveniently, the reference path measurement is made while the flame is stabilized during the change between samples. The reference path measurements are stored and used to correct for drift

  12. A laser driven source of spin polarized atomic hydrogen and deuterium

    International Nuclear Information System (INIS)

    Poelker, M.; Coulter, K.P.; Holt, R.J.; Jones, C.E.; Kowalczyk, R.S.; Young, L.; Toporkov, D.

    1993-01-01

    Recent results from a laser-driven source of polarized hydrogen (H) and deuterium (D) are presented. The performance of the source is described as a function of atomic flow rate and magnetic field. The data suggest that because atomic densities in the source are high, the system can approach spin-temperature equilibrium although applied magnetic fields are much larger than the critical field of the atoms. The authors also observe that potassium contamination in the source emittance can be reduced to a negligible amount using a teflon-lined transport tube

  13. Modified source of a fast neutral atom beam with a controlled energy

    International Nuclear Information System (INIS)

    Gostev, V.A.; Elakhovskij, D.V.; Khakhaev, A.D.

    1980-01-01

    A source of a metastable helium atom beam with a controlled energy based on a phenomenon of resonant ion neutralization on the surface of a solid body is described. The neutral particle energy control is carried out by changing ion velocities before their transformation into metastable atoms. The results of experiments with a modified construction of atomic beam source are stated. These experiments were conducted to find the possibilities to control velocities of atoms in a flow as well as to elucidate the peculiarities of operation of a collimator-converter of this construction. Dependences of a halfwidth of the ion velocity distribution function on the ion source parameters have been investigated. The possibility for particle energy control in a collimated flow of fast neutral. atoms has been experimentally shown, it is also shown that a mean value of atom energy in a beam coincides with a value of mean energy of ions from which atoms are produced by the resonant neutralization method; the construction of the source provides the possibility to realize the method of ''overtaking beams'' for neutral atoms and as a result of this to give a possibility for studying atom-atom collisions in a wide energy range at relatively high densities of flows

  14. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry

    International Nuclear Information System (INIS)

    Alduan, F. A.; Capdevilla, C.

    1980-01-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs

  15. Separation and preconcentration of cadmium ions in natural water using a liquid membrane system with 2-acetylpyridine benzoylhydrazone as carrier by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Granado-Castro, M.D.; Galindo-Riano, M.D. E-mail: dolores.galindo@uca.es; Garcia-Vargas, Manuel

    2004-04-30

    A method for the determination of Cd in natural water by flame atomic absorption spectrometry after separation and preconcentration with a bulk liquid membrane containing 2-acetylpyridine benzoylhydrazone as mobile carrier dissolved in toluene has been developed. Effects of carrier concentration, volume of organic phase and pH of feed and receiving solutions on the flux for Cd across the membrane have been studied, being optimized by the modified simplex method. Optimum values for these variables were: carrier concentration of 0.84 g l{sup -1}, 74 ml of toluene, pH 7.8 in the feed solution and 0.06 mol l{sup -1} of HNO{sub 3} in the receiving solution, allowing a preconcentration factor of 17.9. The preconcentration step required 7 h to be accomplished. The recovery of Cd at optimum conditions was 101.0{+-}2.7%, even with saline matrix, with good relative standard deviation (2.5%) at 95% confidence level. The detection limit of blank sample was 6 ng l{sup -1} of Cd. The method was validated using a certified reference material (TMDA-62) and also applied successfully to the analysis of Cd in four samples of seawater collected from the coast of Huelva (Spain). The relative errors of determinations were -7.6% for certified reference material and ranging between +2.4 and +7.1%, for samples of seawater (obtained between the results of the proposed and differential pulse anodic stripping voltammetry methods)

  16. Combination of flame atomic absorption spectrometry with ligandless-dispersive liquid- liquid microextraction for preconcentration and determination of trace amount of lead in water samples

    Directory of Open Access Journals (Sweden)

    Y.M. Baghelani

    2013-05-01

    Full Text Available A new ligandless-dispersive liquid–liquid microextraction method has been developed for the separation and flame atomic absorption spectrometry determination of trace amount of lead(II ion. In the proposed approach 1,2-dicholorobenzene and ethanol were used as extraction and dispersive solvents. Factors influencing the extraction efficiency of lead, including the extraction and dispersive solvent type and volume, pH of sample solution, concentration of chloride and extraction time were studied. Under the optimal conditions, the calibration curve was linear in the range of 7.0–6000 ng mL−1 of lead with R2 = 0.9992 (n = 10 and detection limit based on three times the standard deviation of the blank (3Sb was 0.5 ng mL−1 in original solution. The relative standard deviation for eight replicate determinations of 1.0 mg mL-1 lead was ±1.6%. The high efficiency of dispersive liquid-liquid microextraction to carry out the determination of trace amounts of lead in complex matrices was demonstrated. The proposed method has been applied for determination of trace amounts of lead in water samples and satisfactory results were obtained. The accuracy was checked by analyzing a certified reference material from the National Institute of Standard and Technology, Trace elements in water (NIST CRM 1643e.

  17. Salt-assisted liquid-liquid microextraction of Cr(VI) ion using an ionic liquid for preconcentration prior to its determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Majidi, B.; Shemirani, F.

    2012-01-01

    We report on the salt-assisted liquid-liquid microextraction of cationic complexes of Cr(VI) ion using the hydrophilic ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoraborate and potassium hydrogen phosphate. This is a novel, simple, non-toxic and effective technique for sample pretreatment technique that displays large extraction efficiency and represents a new platform where Cr(VI) is complexed with 1,5-diphenylcarbazide (DPC) in sulfuric acid medium. It was applied to the extraction of Cr(VI) in the form of the Cr(VI)-DPC complex prior to its determination by flame atomic absorption spectrometry. Cr(III) ion also can be determined by this procedure after oxidation to Cr(VI). Extraction is mainly affected by the amount of water-soluble IL, the kind and quantity of inorganic salts, by pH and the concentration of DPC. Calibration plots are linear in the range from 3 to 150 μg L -1 of Cr(VI), and the limit of detection is 1. 25 μg L -1 . The method was successfully applied to the speciation and determination of trace levels of Cr(III) and Cr(VI) in environmental water samples containing high levels of dissolved salts or food grade salts. (author)

  18. A biosorption system for metal ions on Penicillium italicum - loaded on Sepabeads SP 70 prior to flame atomic absorption spectrometric determinations

    International Nuclear Information System (INIS)

    Mendil, Durali; Tuzen, Mustafa; Soylak, Mustafa

    2008-01-01

    A solid phase extraction (SPE) preconcentration system, coupled to a flame atomic absorption spectrometer (FAAS), was developed for the determination of copper(II), cadmium(II), lead(II), manganese(II), iron(III), nickel(II) and cobalt(II) ions at the μg L -1 levels on Penicillium italicum - loaded on Sepabeads SP 70. The analytes were adsorbed on biosorbent at the pH range of 8.5-9.5. The adsorbed metals were eluted with 1 mol L -1 HCl. The influences of the various analytical parameters including pH of the aqueous solutions, sample volume, flow rates were investigated for the retentions of the analyte ions. The recovery values are ranged from 95-102%. The influences of alkaline, earth alkaline and some transition metal ions were also discussed. Under the optimized conditions, the detection limits (3 s, n = 21) for analytes were in the range of 0.41 μg L -1 (cadmium) and 1.60 μg L -1 (iron). The standard reference materials (IAEA 336 Lichen, NIST SRM 1573a Tomato leaves) were analyzed to verify the proposed method. The method was successfully applied for the determinations of analytes in natural water, cultivated mushroom, lichen (Bryum capilare Hedw), moss (Homalothecium sericeum) and refined table salt samples

  19. Separation and Preconcentration of Ag(1) in Aqueous Samples by Flotation as an Ion-Associate Using Iodide and Ferroin Followed the Determination by Flame Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Hosseini, M.S.; Kardan-Moghaddam, G.; Hashemi-Moghaddam, M.

    2007-01-01

    A simple method for separation/preconcentration and determination of Ag (1) in aqueous samples is described. The method is based on formation of an ion-associate between Ag (1)-iodide complex and ferroin, which can be floated at the interface of the aqueous/n-heptane phases. The flotation process was carried out using 500-ml aliquot of the aqueous solution and the floated layer was dissolved in 5 ml of 1 M HNO 3 containing methanol (50% v/v) as the solvent. The Ag (1) content was then determined by flame atomic absorption spectrometry (FAAS). The method so could be considered as an enrichment process, was achieved to a quantitative feature, when the pH of the solution was adjusted to 4 and the concentrations of iodide and ferroin were about 3.2x10 -4 M and 6.25x10 -5 M, respectively. The LOD and RSD (n=7) were obtained 1.0x10 -8 M and 2.4%, respectively. It was found that a large number of cations and anions even at high considerably foreign ion/Ag(1) ratios were not interfered. The method was applied satisfactorily to recovery of Ag(I) from different aqueous samples

  20. Preconcentrative separation of chromium(III) species from chromium(VI) by cloud point extraction and determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yildiz, Z.; Arslan, G.; Tor, A.

    2011-01-01

    We describe a high-throughput technique for the determination of chromium species in water samples by flame atomic absorption spectrometry (FAAS) after preconcentrative separation of Cr(III) species from Cr(VI) by cloud point extraction (CPE) using diethyldithiocarbamate (DDTC) as the chelating agent and the nonionic surfactant Triton X-100 as the extractant. The Cr(III)-DDTC complex is extracted if the temperature is higher than the CPE temperature of Triton X-100, while Cr(VI) remains in the aqueous phase. The Cr(III) in the surfactant phase was analyzed by FAAS, and the concentration of Cr(VI) was calculated by subtraction of Cr(III) from total chromium which was directly determined by FAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. The detection limit for Cr(III) was 0. 08 μg L -1 with an enrichment factor of 98, and the relative standard deviation was 1. 2% (n = 3, c = 100 μg L -1 ). A certified reference material and several water samples were analyzed with satisfactory results. (author)

  1. On-line preconcentration system using a microcolumn packed with Alizarin Red S-modified alumina for zinc determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    A.M. Haji Shabani

    2009-01-01

    Full Text Available A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 µL of nitric acid (1 mol L-1 and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S of 0.2 µg L-1 was obtained. The precision (RSD, n=7 was 3.0% at the 20 µg L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.

  2. On-line preconcentration system using a minicolumn of polyurethane foam loaded with Me-BTABr for zinc determination by Flame Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Azevedo Lemos, Valfredo; Nei Lopes dos Santos, Walter; Silva Santos, Juracir; Bezerra de Carvalho, Marcilio

    2003-01-01

    In the present paper, an on-line system for preconcentration and determination of zinc by Flame Atomic Absorption Spectrometry (FAAS) is proposed. It is based in the sorption of zinc(II) ions on a minicolumn packed with polyurethane foam loaded with 2-[2'-(6-methyl-benzothiazolylazo)]-4-bromophenol (Me-BTABr) reagent. Chemical and flow variables as pH effect, sample flow rate and eluent concentration were optimized using univariate methodology. The results demonstrated that zinc can determinate using the sample pH in the range of 6.5-9.2, sample flow rate of 6.0 ml min -1 , and the elution step using 0.10 mol l -1 hydrochloric acid solution at flow rate of 5.5 ml min -1 . In these conditions, an enrichment factor of 23 and a sampling rate of 48 samples per hour were achieved. The detection limit (DL, 3σ) as IUPAC recommendation was 0.37 μg l -1 and the precision (assessed as the relative standard deviation, R.S.D.) reached values of 5.9-1.8% in zinc solutions of 1.0-10.0 μg l -1 concentration, respectively. The method was successfully applied to the determination of trace amounts of zinc in natural water samples from Salvador (Brazil)

  3. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang, E-mail: m_ghaedi@mail.yu.ac.ir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Shokrollahi, Ardeshir [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Niknam, Khodabakhsh [Chemistry Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Niknam, Ebrahim; Najibi, Asma [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2009-09-15

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L{sup -1} HNO{sub 3} was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL{sup -1} for Cd{sup 2+}, Pb{sup 2+}, Pd{sup 2+} and Ag{sup +} along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd{sup 2+}, Pb{sup 2+}, Pd{sup 2+} and Ag{sup +}, respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.

  4. Cloud point extraction and flame atomic absorption spectrometric determination of cadmium(II), lead(II), palladium(II) and silver(I) in environmental samples

    International Nuclear Information System (INIS)

    Ghaedi, Mehrorang; Shokrollahi, Ardeshir; Niknam, Khodabakhsh; Niknam, Ebrahim; Najibi, Asma; Soylak, Mustafa

    2009-01-01

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L -1 HNO 3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL -1 for Cd 2+ , Pb 2+ , Pd 2+ and Ag + along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd 2+ , Pb 2+ , Pd 2+ and Ag + , respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.

  5. Preconcentration and determination of iron and copper in spice samples by cloud point extraction and flow injection flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Cigdem Arpa, E-mail: carpa@hacettepe.edu.tr [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey); Tokgoez, Ilknur; Bektas, Sema [Hacettepe University, Chemistry Department, 06800 Beytepe, Ankara (Turkey)

    2010-09-15

    A flow injection (FI) cloud point extraction (CPE) method for the determination of iron and copper by flame atomic absorption spectrometer (FAAS) has been improved. The analytes were complexed with 3-amino-7-dimethylamino-2-methylphenazine (Neutral Red, NR) and octylphenoxypolyethoxyethanol (Triton X-114) was added as a surfactant. The micellar solution was heated above 50 {sup o}C and loaded through a column packed with cotton for phase separation. Then the surfactant-rich phase was eluted using 0.05 mol L{sup -1} H{sub 2}SO{sub 4} and the analytes were determined by FAAS. Chemical and flow variables influencing the instrumental and extraction conditions were optimized. Under optimized conditions for 25 mL of preconcentrated solution, the enrichment factors were 98 and 69, the limits of detection (3s) were 0.7 and 0.3 ng mL{sup -1}, the limits of quantification (10s) were 2.2 and 1.0 ng mL{sup -1} for iron and copper, respectively. The relative standard deviation (RSD) for ten replicate measurements of 10 ng mL{sup -1} iron and copper were 2.1% and 1.8%, respectively. The proposed method was successfully applied to determination of iron and copper in spice samples.

  6. Determination of calcium, magnesium, sodium, and potassium in foodstuffs by using a microsampling flame atomic absorption spectrometric method after closed-vessel microwave digestion: method validation.

    Science.gov (United States)

    Chekri, Rachida; Noël, Laurent; Vastel, Christelle; Millour, Sandrine; Kadar, Ali; Guérin, Thierry

    2010-01-01

    This paper describes a validation process in compliance with the NFIEN ISO/IEC 17025 standard for the determination of the macrominerals calcium, magnesium, sodium, and potassium in foodstuffs by microsampling with flame atomic absorption spectrometry after closed-vessel microwave digestion. The French Standards Commission (Agence Francaise de Normalisation) standards NF V03-110, NF EN V03-115, and XP T-90-210 were used to evaluate this method. The method was validated in the context of an analysis of the 1322 food samples of the second French Total Diet Study (TDS). Several performance criteria (linearity, LOQ, specificity, trueness, precision under repeatability conditions, and intermediate precision reproducibility) were evaluated. Furthermore, the method was monitored by several internal quality controls. The LOQ values obtained (25, 5, 8.3, and 8.3 mg/kg for Ca, Mg, Na, and K, respectively) were in compliance with the needs of the TDS. The method provided accurate results as demonstrated by a repeatability CV (CVr) of < 7% and a reproducibility CV (CVR) of < 12% for all the elements. Therefore, the results indicated that this method could be used in the laboratory for the routine determination of these four elements in foodstuffs with acceptable analytical performance.

  7. Preconcentration of trace amounts of lead in water samples with cetyltrimethylammonium bromide coated magnetite nanoparticles and its determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Mohammad Faraji

    2016-11-01

    Full Text Available A sensitive and simple magnetic solid phase extraction procedure was presented for the preconcentration of lead ions in environmental water samples. In the present study, lead ions form complexes with 1-(2-pyridilazo-2-naphthol reagent (PAN in basic medium, and then are quantitatively extracted to the surface of cetyltrimethylammonium bromide (CTAB-coated magnetite nanoparticles (Fe3O4 NPs. After magnetic separation of adsorbent, the adsorbent was eluted with 0.5% (v/v HCl in methanol prior to its analysis by flame atomic absorption spectrometry (FAAS. The pH of sample, concentrations of PAN, amounts of CTAB and Fe3O4 NPs, sample volume and desorption conditions were optimized. Under optimum conditions, the calibration curve was linear in the range of 0.05–100 ng mL−1 with R2 = 0.9996. Detection and quantification limits of the proposed method were 0.005 and 0.05 ng mL−1, respectively. Enhancement factor of 1050 was achieved using this method to extract 1000 mL of different environmental water samples. Compared with conventional solid phase extraction methods, the advantages of this method still include easy preparation of sorbents, short times of sample pre-treatment, high extraction yield, and high breakthrough volume. It shows great analytical potential in preconcentration of lead from large volume water samples.

  8. Separation and determination of copper in bottled water samples by combination of dispersive liquid--liquid microextraction and microsample introduction flame atomic absorption spectrometry.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2013-01-01

    A new and simple method for the determination of trace amounts of Cu(II) was developed by combination of dispersive liquid-liquid microextraction (DLLME) preconcentration and microsample introduction flame atomic absorption spectrometry. In this method, ethanol and chloroform were chosen as disperser and extraction solvents, respectively, and 1-nitroso-2-naphthol was used as the complexing agent. The factors affecting the extraction efficiency and determination of Cu(II), including extraction and disperser solvent nature and volume, concentration of the complexing agent, pH of the solution, extraction time, and matrix ions, were investigated. Under optimal conditions, the LOD for Cu(II) was 0.95 microg/L with a preconcentration factor of 70. The RSD was 1.9%. The accuracy of the developed DLLME method was verified by determination of Cu(II) in a certified reference material (NRCC-SLRS-4 river water). The relative error was -3.31%. The developed preconcentration procedure was successfully applied to the analysis of bottled drinking water samples.

  9. A novel fiber-packed column for on-line preconcentration and speciation analysis of chromium in drinking water with flame atomic absorption spectrometry.

    Science.gov (United States)

    Monasterio, Romina P; Altamirano, Jorgelina C; Martínez, Luis D; Wuilloud, Rodolfo G

    2009-02-15

    A novel on-line preconcentration and determination system based on a fiber-packed column was developed for speciation analysis of Cr in drinking water samples prior to its determination by flame atomic absorption spectrometry (FAAS). All variables involved in the development of the preconcentration method including, pH, eluent type, sample and eluent flow rates, interfering effects, etc., were studied in order to achieve the best analytical performance. A preconcentration factor of 32 was obtained for Cr(VI) and Cr(III). The levels of Cr(III) species were calculated by difference of total Cr and Cr(VI) levels. Total Cr was determined after oxidation of Cr(III) to Cr(VI) with hydrogen peroxide. The calibration graph was linear with a correlation coefficient of 0.999 at levels near the detection limit and up to at least 50 microg L(-1). The relative standard deviation (R.S.D.) was 4.3% (C=5 microg L(-1) Cr(VI), n=10, sample volume=25 mL). The limit of detection (LOD) for both Cr(III) and Cr(VI) species was 0.3 microg L(-1). Verification of the accuracy was carried out by the analysis of a standard reference material (NIST SRM 1643e "Trace elements in natural water"). The method was successfully applied to the determination of Cr(III) and Cr(VI) species in drinking water samples.

  10. Separation and Enrichment of Gold in Water, Geological and Environmental Samples by Solid Phase Extraction on Multiwalled Carbon Nanotubes Prior to its Determination by Flame Atomic Absorption Spectrometry.

    Science.gov (United States)

    Duran, Ali; Tuzen, Mustafa; Soylak, Mustafa

    2015-01-01

    This study proposes the application of multi-walled carbon nanotubes as a solid sorbent for the preconcentration of gold prior to its flame atomic absorption spectrometry determination. Extraction was achieved by using a glass column (15.0 cm in length and 1.0 cm in diameter). Quantitative recoveries were obtained in the pH range of 2.5-4.0; the elution step was carried out with 5.0 ml of 1.0 mol/L HNO3 in acetone. In the ligand-free study, variables such as pH, eluent type, sample volume, flow rates, and matrix effect were examined for the optimum recovery of gold ions. The gold ions were able to be pre-concentrated by a factor of 150 and their LOD was determined to be 1.71 μg/L. In order to evaluate the accuracy of the developed method, addition-recovery tests were applied for the tap water, mineral water, and sea water samples. Gold recovery studies were implemented using a wet digestion technique for mine and soil samples taken from various media, and this method was also applied for anodic slime samples taken from the factories located in the Kayseri Industrial Zone of Turkey.

  11. A biosorption system for metal ions on Penicillium italicum - loaded on Sepabeads SP 70 prior to flame atomic absorption spectrometric determinations

    Energy Technology Data Exchange (ETDEWEB)

    Mendil, Durali; Tuzen, Mustafa [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Chemistry Department, 38039 Kayseri (Turkey)], E-mail: msoylak@gmail.com

    2008-04-15

    A solid phase extraction (SPE) preconcentration system, coupled to a flame atomic absorption spectrometer (FAAS), was developed for the determination of copper(II), cadmium(II), lead(II), manganese(II), iron(III), nickel(II) and cobalt(II) ions at the {mu}g L{sup -1} levels on Penicillium italicum - loaded on Sepabeads SP 70. The analytes were adsorbed on biosorbent at the pH range of 8.5-9.5. The adsorbed metals were eluted with 1 mol L{sup -1} HCl. The influences of the various analytical parameters including pH of the aqueous solutions, sample volume, flow rates were investigated for the retentions of the analyte ions. The recovery values are ranged from 95-102%. The influences of alkaline, earth alkaline and some transition metal ions were also discussed. Under the optimized conditions, the detection limits (3 s, n = 21) for analytes were in the range of 0.41 {mu}g L{sup -1} (cadmium) and 1.60 {mu}g L{sup -1} (iron). The standard reference materials (IAEA 336 Lichen, NIST SRM 1573a Tomato leaves) were analyzed to verify the proposed method. The method was successfully applied for the determinations of analytes in natural water, cultivated mushroom, lichen (Bryum capilare Hedw), moss (Homalothecium sericeum) and refined table salt samples.

  12. Flame atomic absorption spectrometric determination of trace amounts of heavy metal ions after solid phase extraction using modified sodium dodecyl sulfate coated on alumina

    Energy Technology Data Exchange (ETDEWEB)

    Ghaedi, Mehrorang [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of)], E-mail: m_ghaedi@mail.yu.ac.ir; Niknam, Khodabakhsh [Chemistry Department, Persian Gulf University, Bushehr (Iran, Islamic Republic of); Shokrollahi, Ardeshir; Niknam, Ebrahim; Rajabi, Hamid Reza [Chemistry Department, Yasouj University, Yasouj 75914-353 (Iran, Islamic Republic of); Soylak, Mustafa [Chemistry Department, University of Erciyes, 38039 Kayseri (Turkey)

    2008-06-30

    A sensitive and selective solid phase extraction procedure for the determination of traces of Cu(II), Zn(II), Pb(II) and Fe(III) has been developed. An alumina-sodium dodecyl sulfate (SDS) coated on with meso-phenyl bis(indolyl) methane (MPBIM) was used for preconcentration and determination of Cu(II), Zn(II), Pb(II) and Fe(III) ions by flame atomic absorption spectrometry. The analyte ions were adsorbed quantitatively on adsorbent due to their complexation with MPBIM. Adsorbed metals were quantitatively eluted using 6 mL of 4 mol L{sup -1} nitric acid. The effects of parameters such as pH, amount of alumina, amount of MBITP, flow rate, type and concentration of eluting agent were examined. The effects of interfering ions on the separation-preconcentration of analytes were also investigated. The relative standard deviation of the method was found to be less than 3.0%. The presented procedure was successfully applied for determination of analytes in real samples.

  13. Estimation of perimortal percent carboxy-heme in nonstandard postmortem specimens using analysis of carbon monoxide by GC/MS and iron by flame atomic absorption spectrophotometry.

    Science.gov (United States)

    Middleberg, R A; Easterling, D E; Zelonis, S F; Rieders, F; Rieders, M F

    1993-01-01

    In decomposed, formalin-fixed, embalmed, exhumed, and some fire-dried cases in which normal blood is unavailable, the usual methods for determination of carboxyhemoglobin saturation frequently fail. To address these specimens, a method utilizing both gas chromatography/mass spectrometric (GC/MS) determination of carbon monoxide (CO) and flame atomic absorption spectrophotometry (FAAS) determination of iron (Fe), in the same specimen, was developed. The method is reported here, along with its application to seven pertinent forsensic death investigations. The CO analytical methodology involves acid liberation of the gas from the specimen aliquot in a headspace vial. After heating and equilibrating, a sample of the headspace vapor is injected into the GC/MS system with a gastight syringe. Quantitation is achieved by standard addition comparison utilizing the ideal gas law equation. Iron is quantified by FAAS analysis of the same aliquot used for the CO determination, following nitric acid digestion. The concentration is determined by comparison to a standard curve. A formula for determining the minimum percent carboxy-heme saturation was derived by using the ratio of the amount of CO to the amount of Fe in the aliquot analyzed. Tissue types analyzed include spleen, liver, muscle, dried blood, and unspecified decomposed tissue.

  14. A novel separation/preconcentration technique based on ultrasonic dispersion liquid-liquid microextraction for determination of trace cobalt by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Jingci Li

    2012-12-01

    Full Text Available An improved method for the determination of trace cobalt in water samples has been developed using ultrasonic dispersion liquid-liquid microextraction (US-DLLME prior to flame atomic absorption spectrometry (FAAS analysis. In this method, cobalt was extracted into the fine droplets of carbon tetrachloride after chelate formation with the water soluble ligand, ammonium pyrrolidine dithiocarbamate (APDC. The fine droplets of carbon tetrachloride were formed and dispersed in the aqueous sample with the help of ultrasonic waves which accelerated the formation of the fine cloudy solution without using disperser solvents. Under optimum conditions, the calibration curve was linear in the range of 2.5-500 μg L-1, with a detection limit of 0.8 μg L-1. The relative standard deviation (RSD for ten replicate measurements of 20 and 500 μg L-1 of cobalt were 3.3 and 2.2%. This proposed method was successfully applied to tap water, river water, and sea water, and accuracy was assessed through the analysis of certified reference water or recovery experiments. Operation simplicity, low cost, high enrichment factor, and low consumption of the extraction solvent are the main advantages of the proposed method.DOI: http://dx.doi.org/10.4314/bcse.v26i1.2

  15. Ultratrace Determination of Cr(VI and Pb(II by Microsample Injection System Flame Atomic Spectroscopy in Drinking Water and Treated and Untreated Industrial Effluents

    Directory of Open Access Journals (Sweden)

    Jameel Ahmed Baig

    2013-01-01

    Full Text Available Simple and robust analytical procedures were developed for hexavalent chromium (Cr(VI and lead (Pb(II by dispersive liquid-liquid microextraction (DLLME using microsample injection system coupled with flame atomic absorption spectrophotometry (MIS-FAAS. For the current study, ammonium pyrrolidine dithiocarbamate (APDC, carbon tetrachloride, and ethanol were used as chelating agent, extraction solvent, and disperser solvent, respectively. The effective variables of developed method have been optimized and studied in detail. The limit of detection of Cr(VI and Pb(II were 0.037 and 0.054 µg/L, respectively. The enrichment factors in both cases were 400 with 40 mL of initial volumes. The relative standard deviations (RSDs, were 96%. The proposed method was successfully applied to the determination of Cr(VI and Pb(II at ultratrace levels in natural drinking water and industrial effluents wastewater of Denizli. Moreover, the proposed method was compared with the literature reported method.

  16. Flame Atomic Absorption Spectrometric Determination of Ultra Traces of Thallium(I) ion after Solid Phase Extraction by Octadecyl Silica Membrane Disk Modified by a New Schiff Base

    International Nuclear Information System (INIS)

    Mashhadizadeh, Mohammad Hossein; Moatafavi, Ali; Allah-Abadi, Hossein; Zadmehr, Mohammad Reza

    2004-01-01

    A simple and reliable method has been developed to selectively separate and concentrate trace amounts of thallium ion from real samples for the subsequent measurement by flame atomic absorption spectrometry (FAAS). Thallium ions are absorbed quantitatively during passage of aqueous real samples through an octadecyl bonded silica membrane disk modified by 4-(4-Chloro-phenylazo)-2-[(4-hydroxy-phenylamino)- methyl]-phenol. The retained Tl + ions are then stripped from the disk quantitatively with a minimal amount of thiosulfate solution as eluent. The proposed method permitted large enrichment factors of about 130 and higher. The relative standard deviation for ten replicate extraction of thallium from 1 L samples containing 5 μg thallium is 1.2%. The break through volume for 5 μg thallium is 1000 mL. The limit of detection of the proposed method is 11.2 ng of Tl + per 1000 mL. The effects of various cationic interferences on the recovery of thallium in binary mixtures were studied. The method was applied to the recovery of Tl + ions from natural water and human hair samples

  17. Cloud point extraction of palladium in water samples and alloy mixtures using new synthesized reagent with flame atomic absorption spectrometry (FAAS)

    International Nuclear Information System (INIS)

    Priya, B. Krishna; Subrahmanayam, P.; Suvardhan, K.; Kumar, K. Suresh; Rekha, D.; Rao, A. Venkata; Rao, G.C.; Chiranjeevi, P.

    2007-01-01

    The present paper outlines novel, simple and sensitive method for the determination of palladium by flame atomic absorption spectrometry (FAAS) after separation and preconcentration by cloud point extraction (CPE). The cloud point methodology was successfully applied for palladium determination by using new reagent 4-(2-naphthalenyl)thiozol-2yl azo chromotropic acid (NTACA) and hydrophobic ligand Triton X-114 as chelating agent and nonionic surfactant respectively in the water samples and alloys. The following parameters such as pH, concentration of the reagent and Triton X-114, equilibrating temperature and centrifuging time were evaluated and optimized to enhance the sensitivity and extraction efficiency of the proposed method. The preconcentration factor was found to be (50-fold) for 250 ml of water sample. Under optimum condition the detection limit was found as 0.067 ng ml -1 for palladium in various environmental matrices. The present method was applied for the determination of palladium in various water samples, alloys and the result shows good agreement with reported method and the recoveries are in the range of 96.7-99.4%

  18. A pre-concentration procedure using coprecipitation for determination of lead and iron in several samples using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Saracoglu, S.; Soylak, M.; Peker, D.S. Kacar; Elci, L.; Santos, W.N.L. dos; Lemos, V.A.; Ferreira, S.L.C.

    2006-01-01

    The present paper proposes a pre-concentration procedure for determination of lead and iron in several samples by flame atomic absorption spectrometry. In it, lead(II) and iron(III) ions are coprecipitated using the violuric acid-copper(II) system as collector. Afterwards, the precipitate is dissolved with 1 M HNO 3 solution and the metal ions are determined. The optimization step was performed using factorial design involving the variables: pH, violuric acid mass (VA) and copper concentration (Cu). Using the optimized experimental conditions, the proposed procedure allows the determination these metals with detection limits of 0.18 μg L -1 for iron and 0.16 μg L -1 for lead. The effects of foreign ions on the pre-concentration procedure were also evaluated and the results demonstrated that this method could be applied for determination of iron and lead in several real samples. The proposed method was successfully applied to the analysis of seawater, urine, mineral water, soil and physiological solution samples. The concentrations of lead and iron achieved in these samples agree well with others data reported in the literature

  19. A Green Preconcentration Method for Determination of Cobalt and Lead in Fresh Surface and Waste Water Samples Prior to Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Naeemullah

    2012-01-01

    Full Text Available Cloud point extraction (CPE has been used for the preconcentration and simultaneous determination of cobalt (Co and lead (Pb in fresh and wastewater samples. The extraction of analytes from aqueous samples was performed in the presence of 8-hydroxyquinoline (oxine as a chelating agent and Triton X-114 as a nonionic surfactant. Experiments were conducted to assess the effect of different chemical variables such as pH, amounts of reagents (oxine and Triton X-114, temperature, incubation time, and sample volume. After phase separation, based on the cloud point, the surfactant-rich phase was diluted with acidic ethanol prior to its analysis by the flame atomic absorption spectrometry (FAAS. The enhancement factors 70 and 50 with detection limits of 0.26 μg L−1 and 0.44 μg L−1 were obtained for Co and Pb, respectively. In order to validate the developed method, a certified reference material (SRM 1643e was analyzed and the determined values obtained were in a good agreement with the certified values. The proposed method was applied successfully to the determination of Co and Pb in a fresh surface and waste water sample.

  20. Synthesize of silver-nanoparticles by plant extract and its application for preconcentration of cadmium followed by flame atomic absorption spectrometry.

    Science.gov (United States)

    Almertaha, Abdul-Hossein; Eftekhari, Mohammad; Chamsaz, Mahmoud; Gheibi, Mohammad

    2018-02-02

    In this paper, Mentha pulegium leaves extract was used as a green reducing agent for the synthesis of silver-nanoparticles. The synthesized silver-nanoparticles were characterized by UV-VIS spectrophotometry, transmission electron microscopy, X-ray spectroscopy and used as an adsorbent for preconcentration of trace levels of cadmium (ІІ). After the desorption of cadmium (ІІ) in 5 mol L -1 formic acid, the desorbent solution was aspirated into the flame atomic absorption spectrometry for the determination of cadmium. In order to optimize the experimental condition, a response surface methodology based on central composite design was used. The optimum conditions are: pH: 8.6, amounts of adsorbent: 30 mg, 10 min extraction time and desorption time of 2 min. Under the optimum condition, the calibration curve was linear in the range of 5-200 μg L -1 cadmium (ІІ) ion with a correlation coefficient of 0.9995. The limit of detection was 1.1 μg L -1 and the relative standard deviation for 25 μg L -1 cadmium (ІІ) ion was 3.0% (n = 5). In order to check the applicability of the proposed method, different real samples were analyzed. Also, the accuracy of this method was successfully checked by the analysis of certified reference material and spike tests.

  1. A new cloud point extraction procedure for determination of inorganic antimony species in beverages and biological samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan

    2015-05-15

    A new cloud-point extraction (CPE) for the determination of antimony species in biological and beverages samples has been established with flame atomic absorption spectrometry (FAAS). The method is based on the fact that formation of the competitive ion-pairing complex of Sb(III) and Sb(V) with Victoria Pure Blue BO (VPB(+)) at pH 10. The antimony species were individually detected by FAAS. Under the optimized conditions, the calibration range for Sb(V) is 1-250 μg L(-1) with a detection limit of 0.25 μg L(-1) and sensitive enhancement factor of 76.3 while the calibration range for Sb(III) is 10-400 μg L(-1) with a detection limit of 5.15 μg L(-1) and sensitive enhancement factor of 48.3. The precision as a relative standard deviation is in range of 0.24-2.35%. The method was successfully applied to the speciative determination of antimony species in the samples. The validation was verified by analysis of certified reference materials (CRMs). Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A dispersive liquid--liquid microextraction methodology for copper (II) in environmental samples prior to determination using microsample injection flame atomic absorption spectrometry.

    Science.gov (United States)

    Alothman, Zeid A; Habila, Mohamed; Yilmaz, Erkan; Soylak, Mustafa

    2013-01-01

    A simple, environmentally friendly, and efficient dispersive liquid-liquid microextraction method combined with microsample injection flame atomic absorption spectrometry was developed for the separation and preconcentration of Cu(II). 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (5-Br-PADAP) was used to form a hydrophobic complex of Cu(II) ions in the aqueous phase before extraction. To extract the Cu(II)-5-Br-PADAP complex from the aqueous phase to the organic phase, 2.0 mL of acetone as a disperser solvent and 200 microL of chloroform as an extraction solvent were used. The influences of important analytical parameters, such as the pH, types and volumes of the extraction and disperser solvents, amount of chelating agent, sample volume, and matrix effects, on the microextraction procedure were evaluated and optimized. Using the optimal conditions, the LOD, LOQ, preconcentration factor, and RSD were determined to be 1.4 microg/L, 4.7 microg/L, 120, and 6.5%, respectively. The accuracy of the proposed method was investigated using standard addition/recovery tests. The analysis of certified reference materials produced satisfactory analytical results. The developed method was applied for the determination of Cu in real samples.

  3. Application of l-cystine modified zeolite for preconcentration and determination of ultra-trace levels of cadmium by flame atomic absorption spectrometry.

    Science.gov (United States)

    Rezvani, Seyyed Ahmad; Soleymanpour, Ahmad

    2016-03-04

    A very convenient, sensitive and precise solid phase extraction (SPE) system was developed for enrichment and determination of ultra-trace of cadmium ion in water and plant samples. This method was based on the retention of cadmium(II) ions by l-cystine adsorbed in Y-zeolite and carry out in a packed mini-column. The retained cadmium ions then were eluted and determined by flame atomic absorption spectrometry. The scanning electron microscopy (SEM), powder X-ray diffraction (XRD) and Fourier Transform Infrared (FT-IR) spectroscopy techniques were applied for the characterization of cystine modified zeolite (CMZ). Some experimental conditions affecting the analytical performance such as pH, eluent type, concentration of sample, eluent flow rate and also the presence of interfering ions were investigated. The calibration graph was linear within the range of 0.1-7.5ngmL(-1) and limit of detection was obtained 0.04ngmL(-1) with the preconcentration factor of 400. The relative standard deviation (RSD) was obtained 1.4%, indicating the excellent reproducibility of this method. The proposed method was successfully applied for the extraction and determination of cadmium(II) ion in black tea, cigarette's tobacco and also various water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry in water samples

    Directory of Open Access Journals (Sweden)

    Arpa Şahin Ç.

    2013-04-01

    Full Text Available A simple, rapid and inexpensive solidified floating organic drop microextraction (SFODME and flow injection flame atomic absorption spectrometric determination (FI-FAAS method for copper was developed. 3-amino-7-dimethylamino-2-methylphenazine (Neutral red, NR was used as the complexing agent. Several factors affecting the microextraction efficiency, such as, pH, NR and sodium dodecylbenzenesulfonate (SDBS concentration, extraction time, stirring rate, and temperature were investigated and optimized. Under optimized experimental conditions an enrichment factor of 541 was obtained for 100 mL of sample solution. The calibration graph was linear in the range of 0.5 – 20.0 ng mL–1 and the limit of detection (3s was 0.18 ng mL–1, the limit of quantification (10s was 0.58 ng mL–1. The relative standard deviation (RSD for 10 replicate measurements of 10 ng mL–1 copper was 2.7%. The developed method was successfully applied to the extraction and determination of copper in different certified reference materials (Estuarine water, Slew 3 and fortified water, TM 23.2 and real water samples and satisfactory results were obtained.

  5. On-line micro-volume introduction system developed for lower density than water extraction solvent and dispersive liquid–liquid microextraction coupled with flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Anthemidis, Aristidis N.; Mitani, Constantina; Balkatzopoulou, Paschalia; Tzanavaras, Paraskevas D.

    2012-01-01

    Highlights: ► A dispersive liquid–liquid micro extraction method for lead and copper determination. ► A micro-volume transportation system for extractant solvent lighter than water. ► Analysis of natural water samples. - Abstract: A simple and fast preconcentration/separation dispersive liquid–liquid micro extraction (DLLME) method for metal determination based on the use of extraction solvent with lower density than water has been developed. For this purpose a novel micro-volume introduction system was developed enabling the on-line injection of the organic solvent into flame atomic absorption spectrometry (FAAS). The effectiveness and efficiency of the proposed system were demonstrated for lead and copper preconcentration in environmental water samples using di-isobutyl ketone (DBIK) as extraction solvent. Under the optimum conditions the enhancement factor for lead and copper was 187 and 310 respectively. For a sample volume of 10 mL, the detection limit (3 s) and the relative standard deviation were 1.2 μg L −1 and 3.3% for lead and 0.12 μg L −1 and 2.9% for copper respectively. The developed method was evaluated by analyzing certified reference material and it was applied successfully to the analysis of environmental water samples.

  6. Quantitative analysis of sodium di-uranate for Al, Ca, Fe, Mg, Mn, Na by flame-atomic absorption spectrometric method

    International Nuclear Information System (INIS)

    Jat, J.R.; Balaji Rao, Y.; Subba Rao, Y.

    2015-01-01

    Nuclear Fuel Complex (NFC) receives Sodium Di-Uranate (SDU) from Uranium Corporation of India Limited (UCIL) for producing sinterable UO 2 pellets for manufacturing fuel sub assemblies. Several impurities present in ore find their way into SDU during its conversion. Stringent specification have been laid down by the reactor designs for achieving the optimum performance of the fuel and several impurity element like Al, Ca, Fe, Mg, Mn, Na among others affects severely performance of UO 2 fuel. Most of the impurity including the above mentioned elements are generally analysed by ICP-OES method. However, determination of Al, Ca, Fe, Mg, Mn and Na by ICP-OES requires lot of dilution as they are present at high levels in SDU. Apart from introducing dilution error, dilution process is very tedious and time consuming work and not a preferred choice in an industrial lab like control lab where large analytical load exists and time bound analysis is a requirement. To avoid these difficulties a simple and reliable Flame Atomic absorption spectrometric technique has been developed for regular analysis. Present method involves dissolution of SDU sample in Conc. HNO 3 and after the complete dissolution the sample solution has been evaporated to near dryness on a hot plate. Subsequently sample solution has been brought into 4N HNO 3 medium

  7. Solid phase extraction of lead on octadecyl bonded silica membrane disk modified with Cyanex302 and determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Karve, Manjusha; Rajgor, Reeta V.

    2007-01-01

    A simple, reliable and rapid method for preconcentration and determination of lead using octadecyl bonded silica membrane disk impregnated with Cyanex302 and flame atomic absorption spectrometry is presented. The influence of aqueous phase pH, type of eluent, flow rates of sample solution and eluent, volume of eluent and amount of extractant has been investigated. The break through volume is greater than 4.0 dm 3 with an enrichment factor of more than 400 and a detection limit of 1.0 μg dm -3 . The method developed for determination of lead is good as six replicate determinations using 100 cm 3 solution containing lead in the range 1-4900 μg provides a relative standard deviation (R.S.D.) of 0.4%. The selectivity of the proposed method was confirmed from the interference studies. The developed procedure was successfully applied for the determination of lead in spiked sea water, USGS standard soil sample, sludge and industrial effluents, medicinal formulation, plant, some food products and wine

  8. Laser-driven source of spin-polarized atomic hydrogen and deuterium

    International Nuclear Information System (INIS)

    Poelker, M.

    1995-01-01

    A laser-driven source of spin-polarized hydrogen (H) and deuterium (D) that relies on the technique of optical pumping spin exchange has been constructed. In this source, H or D atoms and potassium atoms flow continuously through a drifilm-coated spin-exchange cell where potassium atoms are optically pumped with circularly-polarized laser light in a high magnetic field. The H or D atoms become polarized through spin-exchange collisions with polarized potassium atoms. High electron polarization (∼80%) has been measured for H and D atoms at flow rates ∼2x10 17 atoms/s. Lower polarization values are measured for flow rates exceeding 1x10 18 atoms/s. In this paper, we describe the performance of the laser-driven source as a function of H and D atomic flow rate, magnetic field strength, alkali density and pump-laser power. Polarization measurements as a function of flow rate and magnetic field suggest that, despite a high magnetic field, atoms within the optical-pumping spin-exchange apparatus evolve to spin-temperature equilibrium which results in direct polarization of the H and D nuclei. (orig.)

  9. Alternate Funding Sources for the International Atomic Energy Agency

    Energy Technology Data Exchange (ETDEWEB)

    Toomey, Christopher; Wyse, Evan T.; Kurzrok, Andrew J.; Swarthout, Jordan M.

    2012-09-04

    Since 1957, the International Atomic Energy Agency (IAEA) has worked to ensure the safe and responsible promotion of nuclear technology throughout the world. The IAEA operates at the intersection of the Nuclear Nonproliferation Treaty’s (NPT) fourth and third articles, which guarantee Parties to the Treaty the right to peaceful uses of nuclear technology, provided those activities are placed under safeguards verified by the IAEA. However, while the IAEA has enjoyed substantial success and prestige in the international community, there is a concern that its resources are being stretched to a point where it may no longer be possible to execute its multifaceted mission in its entirety. As noted by the Director General (DG) in 2008, demographics suggest that every aspect of the IAEA’s operations will be in higher demand due to increasing reliance on non-carbon-based energy and the concomitant nonproliferation, safety, and security risks that growth entails. In addition to these nuclear energy concerns, the demand for technical developmental assistance in the fields of food security, resource conservation, and human health is also predicted to increase as the rest of the world develops. Even with a 100% value-for-money rating by the U.S. Office of Management and Budget (OMB) and being described as an “extraordinary bargain” by the United Nations Secretary-General’s High-level Panel on Threats, Challenges and Change, real budget growth at the Agency has been limited to zero-real growth for a better part of the last two decades. Although the 2012 regular budget (RB) received a small increase for most programs, the 2013 RB has been set at zero-real growth. As a result, the IAEA has had to defer infrastructure investments, which has hindered its ability to provide the public goods its Members seek, decreased global security and development opportunities, and functionally transformed the IAEA into a charity, dependent on extrabudgetary (EB) contributions to sustain

  10. Buffer choice and effects of sample composition examined by experiment planning methods for determination of molybdenum by atomic absorption with a flame atomizer

    International Nuclear Information System (INIS)

    Zav'yalkov, P.I.; Danishehvskii, A.L.; Rakita, R.A.; Yakshinskii, A.I.

    1986-01-01

    The authors use orthogonal experiment planning to define the optimum form of buffer and to establish the effects of sample composition since there are high levels of cation and anion interference in the atomic-absorption determination of molybdenum. A spectroscopic buffer has been identified (HCLO 4 + NH 4 Cl mixture), which eliminates the interference from the elements tested and improves the analytical characteristics in determining molybdenum. A model has been formulated enabling one to estimate the buffer performance and the effects of the components on the determination of molybdenum. The model enables one to forecast the expected order of the effect without performing additional experiments

  11. Combination of dispersive liquid-liquid microextraction with flame atomic absorption spectrometry using microsample introduction for determination of lead in water samples.

    Science.gov (United States)

    Naseri, Mohammad Taghi; Hemmatkhah, Payam; Hosseini, Mohammad Reza Milani; Assadi, Yaghoub

    2008-03-03

    The dispersive liquid-liquid microextraction (DLLME) was combined with the flame atomic absorption spectrometry (FAAS) for determination of lead in the water samples. Diethyldithiophosphoric acid (DDTP), carbon tetrachloride and methanol were used as chelating agent, extraction solvent and disperser solvent, respectively. A new FAAS sample introduction system was employed for the microvolume nebulization of the non-flammable chlorinated organic extracts. Injection of 20 microL volumes of the organic extract into an air-acetylene flame provided very sensitive spike-like and reproducible signals. Some effective parameters on the microextraction and the complex formation were selected and optimized. These parameters include extraction and disperser solvent type as well as their volume, extraction time, salt effect, pH and amount of the chelating agent. Under the optimized conditions, the enrichment factor of 450 was obtained from a sample volume of 25.0 mL. The enhancement factor, calculated as the ratio of the slopes of the calibration graphs with and without preconcentration, which was about 1000. The calibration graph was linear in the range of 1-70 microgL(-1) with a detection limit of 0.5 microgL(-1). The relative standard deviation (R.S.D.) for seven replicate measurements of 5.0 and 50 microgL(-1) of lead were 3.8 and 2.0%, respectively. The relative recoveries of lead in tap, well, river and seawater samples at the spiking level of 20 microgL(-1) ranged from 93.8 to 106.2%. The characteristics of the proposed method were compared with those of the liquid-liquid extraction (LLE), cloud point extraction (CPE), on-line and off-line solid-phase extraction (SPE) as well as co-precipitation, based on bibliographic data. Operation simplicity, rapidity, low cost, high enrichment factor, good repeatability, and low consumption of the extraction solvent at a microliter level are the main advantages of the proposed method.

  12. Combination of dispersive liquid-liquid microextraction with flame atomic absorption spectrometry using microsample introduction for determination of lead in water samples

    International Nuclear Information System (INIS)

    Naseri, Mohammad Taghi; Hemmatkhah, Payam; Hosseini, Mohammad Reza Milani; Assadi, Yaghoub

    2008-01-01

    The dispersive liquid-liquid microextraction (DLLME) was combined with the flame atomic absorption spectrometry (FAAS) for determination of lead in the water samples. Diethyldithiophosphoric acid (DDTP), carbon tetrachloride and methanol were used as chelating agent, extraction solvent and disperser solvent, respectively. A new FAAS sample introduction system was employed for the microvolume nebulization of the non-flammable chlorinated organic extracts. Injection of 20 μL volumes of the organic extract into an air-acetylene flame provided very sensitive spike-like and reproducible signals. Some effective parameters on the microextraction and the complex formation were selected and optimized. These parameters include extraction and disperser solvent type as well as their volume, extraction time, salt effect, pH and amount of the chelating agent. Under the optimized conditions, the enrichment factor of 450 was obtained from a sample volume of 25.0 mL. The enhancement factor, calculated as the ratio of the slopes of the calibration graphs with and without preconcentration, which was about 1000. The calibration graph was linear in the range of 1-70 μg L -1 with a detection limit of 0.5 μg L -1 . The relative standard deviation (R.S.D.) for seven replicate measurements of 5.0 and 50 μg L -1 of lead were 3.8 and 2.0%, respectively. The relative recoveries of lead in tap, well, river and seawater samples at the spiking level of 20 μg L -1 ranged from 93.8 to 106.2%. The characteristics of the proposed method were compared with those of the liquid-liquid extraction (LLE), cloud point extraction (CPE), on-line and off-line solid-phase extraction (SPE) as well as co-precipitation, based on bibliographic data. Operation simplicity, rapidity, low cost, high enrichment factor, good repeatability, and low consumption of the extraction solvent at a microliter level are the main advantages of the proposed method

  13. Determination of silicon in biomass and products of pyrolysis process via high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Nakadi, Flávio V; Prodanov, Caroline; Boschetti, Wiliam; Vale, Maria Goreti R; Welz, Bernhard; de Andrade, Jailson B

    2018-03-01

    Thermochemical processes can convert the biomass into fuels, such as bio-oil. The biomass submitted to pyrolysis process, such as fibers, are generally rich in silicon, an element that can lead to damages in an engine when there is high concentration in a fuel. High-resolution continuum source atomic absorption spectrometry (HR-CS AAS) is an interesting alternative for Si determination in the products and byproducts of the pyrolysis process because, besides the flame (F) and graphite furnace (GF) atomizers, it has enhanced the application of direct analysis of solid samples (SS) within GF. This study aimed the development of methods to determine Si in biomass samples, their products and byproducts using HR-CS AAS. A high-resolution continuum source atomic absorption spectrometer contrAA 700 equipped with F and GF atomizers was used throughout the study. HR-CS F AAS (λ = 251.611nm, 1 detection pixel, N 2 O/C 2 H 2 flame) was used to evaluate Si content in biomass and ash, after a microwave-assisted acid digestion with HNO 3 and HF. HR-CS GF AAS (T pyr = 1400°C, T atom = 2650°C) has evaluated Si in pyrolysis water and bio-oil at 251.611nm, and in peach pit biomass and ash at 221.174nm using SS, both wavelengths with 1 detection pixel. Rhodium (300μg) was applied as permanent modifier and 10μgPd + 6μg Mg were pipetted onto the standards/samples at each analysis. Three different biomass samples were studied: palm tree fiber, coconut fiber and peach pit, and three certified reference materials (CRM) were used to verify the accuracy of the methods. The figures of merit were LOD 0.09-20mgkg -1 , and LOQ 0.3-20mgkg -1 , considering all the methods. There were no significant differences between the CRM certified values and the determined ones, using a Student t-test with a confidence interval of 95% (n = 5). Si concentration ranged from 0.11-0.92% mm -1 , 1.1-1.7mgkg -1 , 3.3-13mgkg -1 , and 0.41-1.4%mm -1 , in biomass, bio-oil, pyrolysis water and ash, respectively

  14. Inductively coupled plasma as atomization, excitation and ionization sources in analytical atomic spectrometry

    International Nuclear Information System (INIS)

    Kawaguchi, Hiroshi

    1996-01-01

    Studies on inductively coupled plasma (ICP) for atomic emission and mass spectrometry accomplished in our laboratory since 1978 are reviewed. In emission spectrometry, the characteristics of the plasma are studied concerning the spatial profiles of spectral line intensity, axial profiles of gas and excitation temperatures, spectral line widths and matrix effect. The studies are particularly emphasized on the instrumentation such as developments of plasma generator, emission spectrometers, water-cooled torches and sample introduction methods. A slew-scan type spectrometer developed in these works represents a predecessor of the current commercial spectrometers. An ICP mass spectrometer was first developed in Japan in this laboratory in 1984. Non-spectroscopic interference of this method was found to have the correlation with the atomic weight of the matrix element. Plasma gases other than argon such as nitrogen and oxygen were used for the ICP to evaluate their performance in mass spectrometry as for the sensitivity and interferences. (author). 63 refs

  15. Flame Length

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Flame length was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The tool...

  16. Atomic-absorption determination of mercury in geological materials by flame and carbon-rod atomisation after solvent extraction and using co-extracted silver as a matrix modifier

    Science.gov (United States)

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

    1983-01-01

    Based on modifications and expansion of the original Tindall's solvent extraction flame atomic-absorption procedure, an atomic-absorption spectrophotometric method has been developed for the determination of mercury in geological materials. The sample is digested with nitric and hydrochloric acids in a boiling water-bath. The solution is made ammoniacal and potassium iodide and silver nitrate are added. The mercury is extracted into isobutyl methyl ketone as the tetraiodomercurate(ll). Added silver is co-extracted with mercury and serves as a matrix modifier in the carbon-rod atomiser. The mercury in the isobutyl methyl ketone extract may be determined by either the flame- or the carbon-rod atomisation method, depending on the concentration level. The limits of determination are 0.05-10 p.p.m. of mercury for the carbon-rod atomisation and 1 -200 p.p.m. of mercury for the flame atomisation. Mercury values for reference samples obtained by replicate analyses are in good agreement with those reported by other workers, with relative standard deviations ranging from 2.3 to 0.9%. Recoveries of mercury spiked at two levels were 93-106%. Major and trace elements commonly found in geological materials do not interfere.

  17. Cloud point extraction for determination of lead in blood samples of children, using different ligands prior to analysis by flame atomic absorption spectrometry: A multivariate study

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Faheem, E-mail: shah_ceac@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Kazi, Tasneem Gul, E-mail: tgkazi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Afridi, Hassan Imran, E-mail: hassanimranafridi@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Naeemullah, E-mail: khannaeemullah@ymail.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan); Arain, Muhammad Balal, E-mail: bilal_ku2004@yahoo.com [Department of Chemistry, University of Science and Technology, Bannu, KPK (Pakistan); Baig, Jameel Ahmed, E-mail: jab_mughal@yahoo.com [National Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro 76080 (Pakistan)

    2011-09-15

    Highlights: {yields} Trace levels of lead in blood samples of healthy children and with different kidney disorders {yields} Pre-concentration of Pb{sup +2} in acid digested blood samples after chelating with two complexing reagents. {yields} Multivariate technique was used for screening of significant factors that influence the CPE of Pb{sup +2} {yields} The level of Pb{sup +2} in diseased children was significantly higher than referents of same age group. - Abstract: The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of lead (Pb{sup 2+}) from digested blood samples after simultaneous complexation with ammonium pyrrolidinedithiocarbamate (APDC) and diethyldithiocarbamate (DDTC) separately. The complexed analyte was quantitatively extracted with octylphenoxypolyethoxyethanol (Triton X-114). The multivariate strategy was applied to estimate the optimum values of experimental factors. Acidic ethanol was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometer (FAAS). The detection limit value of Pb{sup 2+} for the preconcentration of 10 mL of acid digested blood sample was 1.14 {mu}g L{sup -1}. The accuracy of the proposed methods was assessed by analyzing certified reference material (whole blood). Under the optimized conditions of both CPE methods, 10 mL of Pb{sup 2+} standards (10 {mu}g L{sup -1}) complexed with APDC and DDTC, permitted the enhancement factors of 56 and 42, respectively. The proposed method was used for determination of Pb{sup 2+} in blood samples of children with kidney disorders and healthy controls.

  18. Applicability of cloud point extraction for the separation trace amount of lead ion in environmental and biological samples prior to determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Sayed Zia Mohammadi

    2016-09-01

    Full Text Available A sensitive cloud point extraction procedure(CPE for the preconcentration of trace lead prior to its determination by flame atomic absorption spectrometry (FAAS has been developed. The CPE method is based on the complex of Pb(II ion with 1-(2-pyridylazo-2-naphthol (PAN, and then entrapped in the non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of PAN and Triton X-114, equilibration temperature and time, were investigated in detail. A preconcentration factor of 30 was obtained for the preconcentration of Pb(II ion with 15.0 mL solution. Under the optimal conditions, the calibration curve was linear in the range of 7.5 ng mL−1–3.5 μg mL−1 of lead with R2 = 0.9998 (n = 10. Detection limit based on three times the standard deviation of the blank (3Sb was 5.27 ng mL−1. Eight replicate determinations of 1.0 μg mL−1 lead gave a mean absorbance of 0.275 with a relative standard deviation of 1.6%. The high efficiency of cloud point extraction to carry out the determination of analytes in complex matrices was demonstrated. The proposed method has been applied for determination of trace amounts of lead in biological and water samples with satisfactory results.

  19. Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples

    Directory of Open Access Journals (Sweden)

    Xiupei Yang

    2017-03-01

    Full Text Available A cloud point extraction (CPE method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I/diethyldithiocarbamate (DDTC complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL−1 Ag+ in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL−1 for both Zn2+ and Cu2+, 80 μg·mL−1 for Pb2+, 1000 μg·mL−1 for Mn2+, and 100 μg·mL−1 for both Cd2+ and Ni2+. The calibration curve was linear in the range of 1–500 ng·mL−1 with a limit of detection (LOD at 0.3 ng·mL−1. The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.

  20. A preconcentration method for indirect determination of acrylamide from chips, crackers and cereal-based baby foods using flame atomic absorption spectrometry.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan; Orhan, Ulaş

    2016-12-01

    Acrylamide is a toxic species for human health, and is a Maillard reaction product which forms spontaneously in heat treatment process of foods. Therefore, a simple, fast and cost-effective method was developed for the indirect determination of acrylamide in processed foods particularly consumed by children. The method is based on ion-pairing of acrylamide with fluorescein (F 2- ) in presence of Ni(II) ions at pH 9.0, and then extraction of the formed ternary complex into micellar phase of poly(ethyleneglycol-mono-p-nonylphenylether) (PONPE 7.5) before analysis by flame atomic absorption spectrometry (FAAS). The ultrasonic-assisted cloud point extraction (UA-CPE) has been used for the preconcentration of acrylamide in the samples prior to its FAAS detection. The matrix matched calibration curve is linear in range of 0.3-150µgkg -1 under optimal reagent conditions (1.75mL of 0.1molL -1 ammonia buffer at pH 9.0, 2.2mgL -1 Ni(II), 4.0×10 -4 molL -1 F 2- , 0.4% (w/v) NH 4 Cl and 0.7% (v/v) PONPE 7.5) with sensitivity enhancement of 160-fold. The proposed method has been validated by assessment of the following parameters; the limits of detection (LOD) and quantification (LOQ) (0.08µgkg -1 and 0.28µgkg -1 , respectively) with a relative standard deviation (RSD%) lower than 6.3%, and extractive recovery higher than 95% for acrylamide spiked at levels of 5 and 25µgkg -1 . The method was successfully applied to the indirect determination of acrylamide in the processed foods and two CRMs with satisfactory results. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Preparation of modified magnetic nanoparticles as a sorbent for the preconcentration and determination of cadmium ions in food and environmental water samples prior to flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mirabi, Ali; Dalirandeh, Zeinab [Department of Chemistry, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of); Rad, Ali Shokuhi, E-mail: a.shokuhi@qaemshahriau.ac.ir [Department of Chemical Engineering, Qaemshahr Branch, Islamic Azad University, Qaemshahr (Iran, Islamic Republic of)

    2015-05-01

    A new method has been developed for the separation/preconcentration of trace level cadmium ions using diphenyl carbazone/sodium dodecyl sulfate immobilized on magnetic nanoparticle Fe{sub 3}O{sub 4} as a new sorbent SPE and their determination by flame atomic absorption spectrometry (FAAS). Synthesized nanoparticle was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Various influencing parameters on the separation and preconcentration of trace level cadmium ions such as, pH value, amount of nanoparticles, amount of diphenyl carbazone, condition of eluting solution, the effects of matrix ions were examined. The cadmium ions can be eluted from the modified magnetic nanoparticle using 1 mol L{sup −1} HCl as a desorption reagent. The detection limit of this method for cadmium was 3.71 ng ml{sup −1} and the R.S.D. was 0.503% (n=6). The advantages of this new method include rapidity, easy preparation of sorbents and a high concentration factor. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, green tea, rice, tobacco, carrot, lettuce, ginseng, spice, tap water, river water, sea water with satisfactory results. - Highlights: • MNPs method is economical, simple, rapid and sensitive for trace analysis of Cd. • High preconcentration factor was obtained easily through this method. • A detection limit at ng mL{sup −1} level was achieved with 100.0 mL of sample. • This method provides good repeatability and extraction efficiency in a short time.

  2. Iron species determination by task-specific ionic liquid-based in situ solvent formation dispersive liquid-liquid microextraction combined with flame atomic absorption spectrometry.

    Science.gov (United States)

    Sadeghi, Susan; Ashoori, Vahid

    2017-10-01

    The task-specific ionic liquid (TSIL) of 1-ethyl-3-methylimidazolium bromide functionalized with 8-hydroxyquinoline was used as a chelating agent and extracting solvent for dispersive liquid-liquid microextraction and subsequent determination of Fe(III) by flame atomic absorption spectrometry. The in situ solvent formation of TSIL using KPF 6 provided the desired water-immiscible ionic liquid. The total Fe concentration could be determined after pre-oxidation of Fe(II) to Fe(III). Various factors affecting the proposed extraction procedure were optimized. The proposed analytical conditions were: sample pH 5, TSIL amount 0.3% (w/v), KPF 6 amount 0.15% (w/v), anti-sticking 0.1% (w/v) and salt concentration 5% (w/v). Under optimal conditions, the linear dynamic ranges for Fe(III) and total Fe were 20-80 and 20-110 ng mL -1 , respectively, with a detection limit of 6.9 ng mL -1 for Fe(III) and relative standard deviation of 2.2%. The proposed method was successfully applied to the determination of trace Fe(III) in water (underground, tap, refined water and artificial sea water) and beverage (apple, tomato, and tea) samples. The developed method offers advantages such as simplicity, ease of operation, and extraction of Fe(III) from aqueous solutions without the use of organic solvent. It was successfully applied for iron speciation in different real samples. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Simultaneous determination of antimony and boron in beverage and dairy products by flame atomic absorption spectrometry after separation and pre-concentration by cloud-point extraction.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan

    2016-01-01

    A new cloud-point extraction (CPE) method was developed for the pre-concentration and simultaneous determination of Sb(III) and B(III) by flame atomic absorption spectrometry (FAAS). The method was based on complexation of Sb(III) and B(III) with azomethine-H in the presence of cetylpyridinium chloride (CPC) as a signal-enhancing agent, and then extraction into the micellar phase of Triton X-114. Under optimised conditions, linear calibration was obtained for Sb(III) and B(III) in the concentration ranges of 0.5-180 and 2.5-600 μg l(-1) with LODs of 0.15 and 0.75 μg l(-1), respectively. Relative standard deviations (RSDs) (25 and 100 μg l(-1) of Sb(III) and B(III), n = 6) were in a range of 2.1-3.8% and 1.9-2.3%, respectively. Recoveries of spiked samples of Sb(III) and B(III) were in the range of 98-103% and 99-102%, respectively. Measured values for Sb and B in three standard reference materials were within the 95% confidence limit of the certified values. Also, the method was used for the speciation of inorganic antimony. Sb(III), Sb(V) and total Sb were measured in the presence of excess boron before and after pre-reduction with an acidic mixture of KI-ascorbic acid. The method was successfully applied to the simultaneous determination of total Sb and B in selected beverage and dairy products.

  4. Qualitative and Quantitative Content Determination of Macro-Minor Elements in Bryonia Alba L. Roots using Flame Atomic Absorption Spectroscopy Technique.

    Science.gov (United States)

    Karpiuk, Uliana Vladimirovna; Al Azzam, Khaldun Mohammad; Abudayeh, Zead Helmi Mahmoud; Kislichenko, Viktoria; Naddaf, Ahmad; Cholak, Irina; Yemelianova, Oksana

    2016-06-01

    To determine the elements in Bryonia alba L. roots, collected from the Crimean Peninsula region in Ukraine. Dry ashing was used as a flexible method and all elements were determined using atomic absorption spectrometry (AAS) equipped with flame and graphite furnace. The average concentrations of the determined elements, expressed as mg/100 g dry weight of the sample, were as follow: 13.000 for Fe, 78.000 for Si, 88.000 for P, 7.800 for Al, 0.130 for Mn, 105.000 for Mg, 0.030 for Pb, 0.052 for Ni, 0.030 for Mo, 210.000 for Ca, 0.130 for Cu, 5.200 for Zn, 13.000 for Na, 1170.000 for K, 0.780 for Sr, 0.030 for Co, 0.010 for Cd, 0.010 for As, and 0.010 for Hg. Toxic elements such as Cd and Pb were also found but at very low concentration. Among the analyzed elements, K was the most abundant followed by Ca, Mg, P, Si, Fe, Na, and Zn, whereas Hg, As, Cd, Co, Mo, and Pb were found in low concentration. The results suggest that the roots of Bryonia alba L. plant has potential medicinal property through their high element contents present. Moreover, it showed that the AAS method is a simple, fast, and reliable for the determination of elements in plant materials. The obtained results of the current study provide justification for the usage of such fruit in daily diet for nutrition and for medicinal usage in the treatment of various diseases.

  5. Preparation of modified magnetic nanoparticles as a sorbent for the preconcentration and determination of cadmium ions in food and environmental water samples prior to flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mirabi, Ali; Dalirandeh, Zeinab; Rad, Ali Shokuhi

    2015-01-01

    A new method has been developed for the separation/preconcentration of trace level cadmium ions using diphenyl carbazone/sodium dodecyl sulfate immobilized on magnetic nanoparticle Fe 3 O 4 as a new sorbent SPE and their determination by flame atomic absorption spectrometry (FAAS). Synthesized nanoparticle was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Various influencing parameters on the separation and preconcentration of trace level cadmium ions such as, pH value, amount of nanoparticles, amount of diphenyl carbazone, condition of eluting solution, the effects of matrix ions were examined. The cadmium ions can be eluted from the modified magnetic nanoparticle using 1 mol L −1 HCl as a desorption reagent. The detection limit of this method for cadmium was 3.71 ng ml −1 and the R.S.D. was 0.503% (n=6). The advantages of this new method include rapidity, easy preparation of sorbents and a high concentration factor. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, green tea, rice, tobacco, carrot, lettuce, ginseng, spice, tap water, river water, sea water with satisfactory results. - Highlights: • MNPs method is economical, simple, rapid and sensitive for trace analysis of Cd. • High preconcentration factor was obtained easily through this method. • A detection limit at ng mL −1 level was achieved with 100.0 mL of sample. • This method provides good repeatability and extraction efficiency in a short time

  6. Graphene-based solid-phase extraction combined with flame atomic absorption spectrometry for a sensitive determination of trace amounts of lead in environmental water and vegetable samples

    International Nuclear Information System (INIS)

    Wang Yukun; Gao Shutao; Zang Xiaohuan; Li Jingci; Ma Jingjun

    2012-01-01

    Highlights: ► Graphene as a novel sorbent material in a column for solid-phase extraction (SPE). ► SPE for the determination of lead (Pb) in environment water samples and vegetable samples. ► The system can be reused for many times. ► The adsorption capacity of graphene over many other adsorbents. ► Graphene has great potentials as an excellent sorbent material. - Abstract: Graphene, a novel class of carbon nanostructures, has great promise for use as sorbent materials because of its ultrahigh specific surface area. A new method using a column packed with graphene as sorbent was developed for the preconcentration of trace amounts of lead (Pb) using dithizone as chelating reagent prior to its determination by flame atomic absorption spectrometry. Some effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 10.0–600.0 μg L −1 with a detection limit of 0.61 μg L −1 . The relative standard deviation for ten replicate measurements of 20.0 and 400.0 μg L −1 of Pb were 3.56 and 3.25%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Pb. The proposed method was successfully applied in the analysis of environmental water and vegetable samples. Good spiked recoveries over the range of 95.3–100.4% were obtained. This work not only proposes a useful method for sample preconcentration, but also reveals the great potential of graphene as an excellent sorbent material in analytical processes.

  7. Room temperature ionic liquids enhanced the speciation of Cr(VI) and Cr(III) by hollow fiber liquid phase microextraction combined with flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Zeng, Chujie; Lin, Yao; Zhou, Neng; Zheng, Jiaoting; Zhang, Wei

    2012-01-01

    Highlights: ► First reported enhancement effect of RTILs in HF-LPME for the speciation of chromium. ► The addition of RTILs led to 3.5 times improvement of the sensitivity of Cr(VI). ► The proposed method is a simplicity, sensitivity, low cost, green method. - Abstract: A new method for the speciation of Cr(VI) and Cr(III) based on enhancement effect of room temperature ionic liquids (RTILs) for hollow fiber liquid phase microextraction (HF-LPME) combined with flame atomic absorption spectrometry (FAAS) was developed. Room temperature ionic liquids (RTILs) and diethyldithiocarbamate (DDTC) were used enhancement reagents and chelating reagent, respectively. The addition of room temperature ionic liquids led to 3.5 times improvement in the determination of Cr(VI). In this method, Cr(VI) reacts with DDTC yielding a hydrophobic complex, which is subsequently extracted into the lumen of hollow fiber, whereas Cr(III) is remained in aqueous solutions. The extraction organic phase was injected into FAAS for the determination of Cr(VI). Total Cr concentration was determined after oxidizing Cr(III) to Cr(VI) in the presence of KMnO 4 and using the extraction procedure mentioned above. Cr(III) was calculated by subtracting of Cr(VI) from the total Cr. Under optimized conditions, a detection limit of 0.7 ng mL −1 and an enrichment factor of 175 were achieved. The relative standard deviation (RSD) was 4.9% for Cr(VI) (40 ng mL −1 , n = 5). The proposed method was successfully applied to the speciation of chromium in natural water samples with satisfactory results.

  8. Determination of lead and nickel in environmental samples by flame atomic absorption spectrometry after column solid-phase extraction on Ambersorb-572 with EDTA

    Energy Technology Data Exchange (ETDEWEB)

    Baytak, Sitki [Department of Chemistry, Faculty of Science and Arts, Harran University, 63100 Sanliurfa (Turkey); Tuerker, A. Rehber [Department of Chemistry, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey)]. E-mail: aturker@gazi.edu.tr

    2006-02-28

    Lead and nickel were preconcentrated as their ethylenediaminetetraacedic acid (EDTA) complexes from aqueous sample solutions using a column containing Ambersorb-572 and determined by flame atomic absorption spectrometry (FAAS). pH values, amount of solid phase, elution solution and flow rate of sample solution have been optimized in order to obtain quantitative recovery of the analytes. The effect of interfering ions on the recovery of the analytes has also been investigated. The recoveries of Pb and Ni under the optimum conditions were 99 {+-} 2 and 97 {+-} 3%, respectively, at 95% confidence level. Seventy-five-fold (using 750 mL of sample solution and 10 mL of eluent) and 50-fold (using 500 mL of sample solution and 10 mL of eluent) preconcentration was obtained for Pb and Ni, respectively. Time of analysis is about 4.5 h (for obtaining enrichment factor of 75). By applying these enrichment factors, the analytical detection limits of Pb and Ni were found as 3.65 and 1.42 ng mL{sup -1}, respectively. The capacity of the sorbent was found as 0.17 and 0.21 mmol g{sup -1} for Pb and Ni, respectively. The interferences of some cations, such as Mn{sup 2+}, Co{sup 2+}, Fe{sup 3+}, Al{sup 3+}, Zn{sup 2+}, Cd{sup 2+}, Ca{sup 2+}, Mg{sup 2+}, K{sup +} and Na{sup +} usually present in water samples were also studied. This procedure was applied to the determination of lead and nickel in parsley, green onion, sea water and waste water samples. The accuracy of the procedure was checked by determining Pb and Ni in standard reference tea leaves sample (GBW-07605). The results demonstrated good agreement with the certified values.

  9. Validation of the methodology for the quantitative determination of lead in cosmetics dyes available in the national market by atomic absorption spectroscopy with flame

    International Nuclear Information System (INIS)

    Silva Trejos, Paulina

    2008-01-01

    The analytical methodology was validated to quantify lead in cosmetics dyes available on the national market, by the method of atomic absorption spectroscopy with flame. The samples were digested by wet digestion with HNO 3 to 65% m/m in a microwave oven, the percentage of recovery for the digestion of samples of 0,25 g and 0,45 g in 5,00 mL was of 100,5±0,5. The field of optimal linearity detection limit was 5,0 mg/L with a correlation coefficient of 0,9998. The limits of detection and quantification limits determined graphically by the method of row errors for linear regression of 0,12±0,02 mg/L and 0,21±0,02 mg/L, respectively. Precision was evaluated determining the repeatability as standard deviation of five replicas of a positive dye for lead, according to the definition of the ISO, 2√2*, and obtained a value of 2,3. The veracity was determined through percentages of recovery assessed, adding aliquots of lead patterns to dye samples and compared with the same mass to which they are not make additions. The dye samples were obtained at point of sale, such as pharmacies, beauty suppliers, supermarkets, sales of natural products and the central market of San Jose. The dyes tested contain lead acetates active ingredient, these are: Doni, Mont D'Or, Matador y Siempre Joven; they are produced locally, Youthair brand and American manufacturing. (author) [es

  10. Room temperature ionic liquids enhanced the speciation of Cr(VI) and Cr(III) by hollow fiber liquid phase microextraction combined with flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Chujie, E-mail: cjzeng@126.com [Department of Chemistry and Material, Yulin Normal College, Yulin, Guangxi 537000 (China); Lin, Yao; Zhou, Neng; Zheng, Jiaoting; Zhang, Wei [Department of Chemistry and Material, Yulin Normal College, Yulin, Guangxi 537000 (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer First reported enhancement effect of RTILs in HF-LPME for the speciation of chromium. Black-Right-Pointing-Pointer The addition of RTILs led to 3.5 times improvement of the sensitivity of Cr(VI). Black-Right-Pointing-Pointer The proposed method is a simplicity, sensitivity, low cost, green method. - Abstract: A new method for the speciation of Cr(VI) and Cr(III) based on enhancement effect of room temperature ionic liquids (RTILs) for hollow fiber liquid phase microextraction (HF-LPME) combined with flame atomic absorption spectrometry (FAAS) was developed. Room temperature ionic liquids (RTILs) and diethyldithiocarbamate (DDTC) were used enhancement reagents and chelating reagent, respectively. The addition of room temperature ionic liquids led to 3.5 times improvement in the determination of Cr(VI). In this method, Cr(VI) reacts with DDTC yielding a hydrophobic complex, which is subsequently extracted into the lumen of hollow fiber, whereas Cr(III) is remained in aqueous solutions. The extraction organic phase was injected into FAAS for the determination of Cr(VI). Total Cr concentration was determined after oxidizing Cr(III) to Cr(VI) in the presence of KMnO{sub 4} and using the extraction procedure mentioned above. Cr(III) was calculated by subtracting of Cr(VI) from the total Cr. Under optimized conditions, a detection limit of 0.7 ng mL{sup -1} and an enrichment factor of 175 were achieved. The relative standard deviation (RSD) was 4.9% for Cr(VI) (40 ng mL{sup -1}, n = 5). The proposed method was successfully applied to the speciation of chromium in natural water samples with satisfactory results.

  11. Fast determination of trace elements in organic fertilizers using a cup-horn reactor for ultrasound-assisted extraction and fast sequential flame atomic absorption spectrometry.

    Science.gov (United States)

    Teixeira, Leonel Silva; Vieira, Heulla Pereira; Windmöller, Cláudia Carvalhinho; Nascentes, Clésia Cristina

    2014-02-01

    A fast and accurate method based on ultrasound-assisted extraction in a cup-horn sonoreactor was developed to determine the total content of Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn in organic fertilizers by fast sequential flame atomic absorption spectrometry (FS FAAS). Multivariate optimization was used to establish the optimal conditions for the extraction procedure. An aliquot containing approximately 120 mg of the sample was added to a 500 µL volume of an acid mixture (HNO3/HCl/HF, 5:3:3, v/v/v). After a few minutes, 500 µL of deionized water was added and eight samples were simultaneously sonicated for 10 min at 50% amplitude, allowing a sample throughput of 32 extractions per hour. The performance of the method was evaluated with a certified reference material of sewage sludge (CRM 029). The precision, expressed as the relative standard deviation, ranged from 0.58% to 5.6%. The recoveries of analytes were found to 100%, 109%, 96%, 92%, 101%, 104% and 102% for Cd, Cr, Cu, Mn, Ni, Pb and Zn, respectively. The linearity, limit of detection and limit of quantification were calculated and the values obtained were adequate for the quality control of organic fertilizers. The method was applied to the analysis of several commercial organic fertilizers and organic wastes used as fertilizers, and the results were compared with those obtained using the microwave digestion procedure. A good agreement was found between the results obtained by microwave and ultrasound procedures with recoveries ranging from 80.4% to 117%. Two organic waste samples were not in accordance with the Brazilian legislation regarding the acceptable levels of contaminants. © 2013 Published by Elsevier B.V.

  12. Cloud point extraction-flame atomic absorption spectrometry for pre-concentration and determination of trace amounts of silver ions in water samples.

    Science.gov (United States)

    Yang, Xiupei; Jia, Zhihui; Yang, Xiaocui; Li, Gu; Liao, Xiangjun

    2017-03-01

    A cloud point extraction (CPE) method was used as a pre-concentration strategy prior to the determination of trace levels of silver in water by flame atomic absorption spectrometry (FAAS) The pre-concentration is based on the clouding phenomena of non-ionic surfactant, triton X-114, with Ag (I)/diethyldithiocarbamate (DDTC) complexes in which the latter is soluble in a micellar phase composed by the former. When the temperature increases above its cloud point, the Ag (I)/DDTC complexes are extracted into the surfactant-rich phase. The factors affecting the extraction efficiency including pH of the aqueous solution, concentration of the DDTC, amount of the surfactant, incubation temperature and time were investigated and optimized. Under the optimal experimental conditions, no interference was observed for the determination of 100 ng·mL -1 Ag + in the presence of various cations below their maximum concentrations allowed in this method, for instance, 50 μg·mL -1 for both Zn 2+ and Cu 2+ , 80 μg·mL -1 for Pb 2+ , 1000 μg·mL -1 for Mn 2+ , and 100 μg·mL -1 for both Cd 2+ and Ni 2+ . The calibration curve was linear in the range of 1-500 ng·mL -1 with a limit of detection (LOD) at 0.3 ng·mL -1 . The developed method was successfully applied for the determination of trace levels of silver in water samples such as river water and tap water.

  13. Preconcentration and determination of vanadium and molybdenum in milk, vegetables and foodstuffs by ultrasonic-thermostatic-assisted cloud point extraction coupled to flame atomic absorption spectrometry.

    Science.gov (United States)

    Gürkan, Ramazan; Korkmaz, Sema; Altunay, Nail

    2016-08-01

    A new ultrasonic-thermostatic-assisted cloud point extraction procedure (UTA-CPE) was developed for preconcentration at the trace levels of vanadium (V) and molybdenum (Mo) in milk, vegetables and foodstuffs prior to determination via flame atomic absorption spectrometry (FAAS). The method is based on the ion-association of stable anionic oxalate complexes of V(V) and Mo(VI) with [9-(diethylamino)benzo[a]phenoxazin-5-ylidene]azanium; sulfate (Nile blue A) at pH 4.5, and then extraction of the formed ion-association complexes into micellar phase of polyoxyethylene(7.5)nonylphenyl ether (PONPE 7.5). The UTA-CPE is greatly simplified and accelerated compared to traditional cloud point extraction (CPE). The analytical parameters optimized are solution pH, the concentrations of complexing reagents (oxalate and Nile blue A), the PONPE 7.5 concentration, electrolyte concentration, sample volume, temperature and ultrasonic power. Under the optimum conditions, the calibration curves for Mo(VI) and V(V) are obtained in the concentration range of 3-340µgL(-1) and 5-250µgL(-1) with high sensitivity enhancement factors (EFs) of 145 and 115, respectively. The limits of detection (LODs) for Mo(VI) and V(V) are 0.86 and 1.55µgL(-1), respectively. The proposed method demonstrated good performances such as relative standard deviations (as RSD %) (≤3.5%) and spiked recoveries (95.7-102.3%). The accuracy of the method was assessed by analysis of two standard reference materials (SRMs) and recoveries of spiked solutions. The method was successfully applied into the determination of trace amounts of Mo(VI) and V(V) in milk, vegetables and foodstuffs with satisfactory results. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel and its application to a flow analytical system using flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mori, Masanobu; Suzuki, Toshinobu; Sugita, Tsuyoshi; Nagai, Daisuke; Hirayama, Kazuo; Onozato, Makoto; Itabashi, Hideyuki

    2014-01-01

    Highlights: • Calcium-alginate-modified dien-silica gel adsorbed multivalent metal ions. • Metal ions adsorbed on CaAD were eluted using low acidic concentrations. • Flow system with CaAD-packed column enriched metal concentrations up to 50-fold. - Abstract: This study aimed to evaluate the heavy metal adsorptivity of calcium-alginate-modified diethylenetriamine-silica gel (CaAD) and incorporate this biosorbent into a flow analytical system for heavy metal ions using flame atomic absorption spectrometry (FAAS). The biosorbent was synthesized by electrostatically coating calcium alginate onto diethylenetriamine (dien)-silica gel. Copper ion adsorption tests by a batch method showed that CaAD exhibited a higher adsorption rate compared with other biosorbents despite its low maximum adsorption capacity. Next, CaAD was packed into a 1 mL microcolumn, which was connected to a flow analytical system equipped with an FAAS instrument. The flow system quantitatively adsorbed heavy metals and enriched their concentrations. This quantitative adsorption was achieved for pH 3–4 solutions containing 1.0 × 10 −6 M of heavy metal ions at a flow rate of 5.0 mL min −1 . Furthermore, the metal ions were successfully desorbed from CaAD at low nitric acid concentrations (0.05–0.15 M) than from the polyaminecarboxylic acid chelating resin (Chelex 100). Therefore, CaAD may be considered as a biosorbent that quickly adsorbs and easily desorbs analyte metal ions. In addition, the flow system enhanced the concentrations of heavy metals such as Cu 2+ , Zn 2+ , and Pb 2+ by 50-fold. This new enrichment system successfully performed the separation and determination of Cu 2+ (5.0 × 10 −8 M) and Zn 2+ (5.7 × 10 −8 M) in a river water sample and Pb 2+ (3.8 × 10 −9 M) in a ground water sample

  15. Flame atomic absorption spectrometric determination of heavy metals in aqueous solution and surface water preceded by co-precipitation procedure with copper(II) 8-hydroxyquinoline

    Science.gov (United States)

    Ipeaiyeda, Ayodele Rotimi; Ayoade, Abisayo Ruth

    2017-12-01

    Co-precipitation procedure has widely been employed for preconcentration and separation of metal ions from the matrices of environmental samples. This is simply due to its simplicity, low consumption of separating solvent and short duration for analysis. Various organic ligands have been used for this purpose. However, there is dearth of information on the application of 8-hydroxyquinoline (8-HQ) as ligand and Cu(II) as carrier element. The use of Cu(II) is desirable because there is no contamination and background adsorption interference. Therefore, the objective of this study was to use 8-HQ in the presence of Cu(II) for coprecipitation of Cd(II), Co(II), Cr(III), Ni(II) and Pb(II) from standard solutions and surface water prior to their determinations by flame atomic absorption spectrometry (FAAS). The effects of pH, sample volume, amount of 8-HQ and Cu(II) and interfering ions on the recoveries of metal ions from standard solutions were monitored using FAAS. The water samples were treated with 8-HQ under the optimum experimental conditions and metal concentrations were determined by FAAS. The metal concentrations in water samples not treated with 8-HQ were also determined. The optimum recovery values for metal ions were higher than 85.0%. The concentrations (mg/L) of Co(II), Ni(II), Cr(III), and Pb(II) in water samples treated with 8-HQ were 0.014 ± 0.002, 0.03 ± 0.01, 0.04 ± 0.02 and 0.05 ± 0.02, respectively. These concentrations and those obtained without coprecipitation technique were significantly different. Coprecipitation procedure using 8-HQ as ligand and Cu(II) as carrier element enhanced the preconcentration and separation of metal ions from the matrix of water sample.

  16. Feasibility of dispersive liquid–liquid microextraction for extraction and preconcentration of Cu and Fe in red and white wine and determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Seeger, Tassia S.; Rosa, Francisco C.; Bizzi, Cezar A.; Dressler, Valderi L.; Flores, Erico M.M.; Duarte, Fabio A.

    2015-01-01

    A method for extraction and preconcentration of Cu and Fe in red and white wines using dispersive liquid–liquid microextraction (DLLME) and determination by flame atomic absorption spectrometry (F AAS) was developed. Extraction was performed using sodium diethyldithiocarbamate as chelating agent and a mixture of 40 μL of 1,2-dichlorobenzene (extraction solvent) and 900 μL of methanol (dispersive solvent). Some parameters that influencing the extraction efficiency such as pH (2 to 5), concentration of chelating agent (0 to 2%), effect of salt addition (0 to 10%), number of washing steps (1 to 4) and centrifugation time (0 to 15 min) were studied. Accuracy was evaluated after microwave-assisted digestion in closed vessels and analytes were determined by inductively coupled plasma optical emission spectrometry. Agreement with the proposed method ranged from 91 to 110 and from 89 to 113% for Cu and Fe, respectively. Calibration of F AAS instrument was performed using analyte addition method and limits of detection were 6.3 and 2.4 μg L −1 for Cu and Fe, respectively. The proposed method was applied for the determination of Cu and Fe in five samples of red wine and three samples of white wine, with concentration ranging from 21 to 178 μg L −1 and from 1.38 to 3.74 mg L −1 , respectively. - Highlights: • Determination of Cu and Fe in wine using DLLME and F AAS • High preconcentration factors and low LODs were achieved. • Alternative method for the determination of Cu and Fe in wine for routine analysis

  17. A novel solidified floating organic drop microextraction method for preconcentration and determination of copper ions by flow injection flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Sahin, Cigdem Arpa; Tokgoez, Ilknur

    2010-01-01

    A rapid, simple and cost effective solidified floating organic drop microextraction (SFODME) and flow injection flame atomic absorption spectrometric determination (FI-FAAS) method for copper was developed. In this method, a free microdrop of 1-undecanol containing 1,5-diphenyl carbazide (DPC) as the complexing agent was transferred to the surface of an aqueous sample including Cu(II) ions, while being agitated by a stirring bar in the bulk of the solution. Under the proper stirring conditions, the suspended microdrop can remain at the top-center position of the aqueous sample. After the completion of the extraction, the sample vial was cooled by placing it in a refrigerator for 10 min. The solidified microdrop was then transferred into a conical vial, where it melted immediately and diluted to 300 μL with ethanol. Finally, copper ions in 200 μL of diluted solution were determined by FI-FAAS. Several factors affecting the microextraction efficiency, such as type of extraction solvent, pH, complexing agent concentration, extraction time, stirring rate, sample volume and temperature were investigated and optimized. Under optimized conditions for 100 mL of solution, the preconcentration factor was 333 and the enrichment factor was 324. The limit of detection (3 s) was 0.4 ng mL -1 , the limit of quantification (10 s) was 1.1 ng mL -1 and the relative standard deviation (RSD) for 10 replicate measurements of 10 ng mL -1 copper was 0.9%. The proposed method was successfully applied to the determination of copper in different water samples.

  18. Novel analytical reagent for the application of cloud-point preconcentration and flame atomic absorption spectrometric determination of nickel in natural water samples

    International Nuclear Information System (INIS)

    Suvardhan, K.; Rekha, D.; Kumar, K. Suresh; Prasad, P. Reddy; Kumar, J. Dilip; Jayaraj, B.; Chiranjeevi, P.

    2007-01-01

    Cloud-point extraction was applied as a preconcentration of nickel after formation of complex with newly synthesized N-quino[8,7-b]azin-5-yl-2,3,5,6,8,9,11,12octahydrobenzo[b][1,4,7,10,13] pentaoxacyclopentadecin-15-yl-methanimine, and later determined by flame atomic absorption spectrometry (FAAS) using octyl phenoxy polyethoxy ethanol (Triton X-114) as surfactant. Nickel was complexed with N-quino[8,7-b]azin-5-yl-2,3,5,6,8,9,11,12 octahydrobenzo[b][1,4,7,10,13]pentaoxacyclopentadecin-15-yl-methanimine in an aqueous phase and was kept for 15 min in a thermo-stated bath at 40 deg. C. Separation of the two phases was accomplished by centrifugation for 15 min at 4000 rpm. The chemical variables affecting the cloud-point extraction were evaluated, optimized and successfully applied to the nickel determination in various water samples. Under the optimized conditions, the preconcentration system of 100 ml sample permitted an enhancement factor of 50-fold. The detailed study of various interferences made the method more selective. The detection limits obtained under optimal condition was 0.042 ng ml -1 . The extraction efficiency was investigated at different nickel concentrations (20-80 ng ml -1 ) and good recoveries (99.05-99.93%) were obtained using present method. The proposed method has been applied successfully for the determination of nickel in various water samples and compared with reported method in terms of Student's t-test and variance ratio f-test which indicate the significance of present method over reported and spectrophotometric methods at 95% confidence level

  19. Quality assessment of trace Cd and Pb contaminants in Thai herbal medicines using ultrasound-assisted digestion prior to flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Watsaka Siriangkhawut

    2017-10-01

    Full Text Available A simple, efficient, and reliable ultrasound-assisted digestion (UAD procedure was used for sample preparation prior to quantitative determination of trace Cd and Pb contaminants in herbal medicines using flame atomic absorption spectrometry. The parameters influencing UAD such as the solvent system, sample mass, presonication time, sonication time, and digestion temperature were evaluated. The efficiency of the proposed UAD procedure was evaluated by comparing with conventional acid digestion (CAD procedure. Under the optimum conditions, linear calibration graphs in a range of 2–250 μg/L for Cd, and 50–1000 μg/L for Pb were obtained with detection limits of 0.56 μg/L and 10.7 μg/L for Cd and Pb, respectively. The limit of quantification for Cd and Pb were 1.87 μg/L and 40.3 μg/L, respectively. The repeatability for analysis of 10 μg/L for Cd and 100 μg/L for Pb was 2.3% and 2.6%, respectively. The accuracy of the proposed method was evaluated by rice flour certified reference materials. The proposed method was successfully applied for analysis of trace Cd and Pb in samples of various types of medicinal plant and traditional medicine consumed in Thailand. Most herbal medicine samples were not contaminated with Cd or Pb. The contaminant levels for both metals were still lower than the maximum permissible levels of elements in medicinal plant materials and finished herbal products sets by the Ministry of Public Health of Thailand. The exception was the high level of Cd contamination found in two samples of processed medicinal plants.

  20. Feasibility of dispersive liquid–liquid microextraction for extraction and preconcentration of Cu and Fe in red and white wine and determination by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Tassia S.; Rosa, Francisco C.; Bizzi, Cezar A.; Dressler, Valderi L.; Flores, Erico M.M.; Duarte, Fabio A., E-mail: fabioand@gmail.com

    2015-03-01

    A method for extraction and preconcentration of Cu and Fe in red and white wines using dispersive liquid–liquid microextraction (DLLME) and determination by flame atomic absorption spectrometry (F AAS) was developed. Extraction was performed using sodium diethyldithiocarbamate as chelating agent and a mixture of 40 μL of 1,2-dichlorobenzene (extraction solvent) and 900 μL of methanol (dispersive solvent). Some parameters that influencing the extraction efficiency such as pH (2 to 5), concentration of chelating agent (0 to 2%), effect of salt addition (0 to 10%), number of washing steps (1 to 4) and centrifugation time (0 to 15 min) were studied. Accuracy was evaluated after microwave-assisted digestion in closed vessels and analytes were determined by inductively coupled plasma optical emission spectrometry. Agreement with the proposed method ranged from 91 to 110 and from 89 to 113% for Cu and Fe, respectively. Calibration of F AAS instrument was performed using analyte addition method and limits of detection were 6.3 and 2.4 μg L{sup −1} for Cu and Fe, respectively. The proposed method was applied for the determination of Cu and Fe in five samples of red wine and three samples of white wine, with concentration ranging from 21 to 178 μg L{sup −1} and from 1.38 to 3.74 mg L{sup −1}, respectively. - Highlights: • Determination of Cu and Fe in wine using DLLME and F AAS • High preconcentration factors and low LODs were achieved. • Alternative method for the determination of Cu and Fe in wine for routine analysis.

  1. An Atmospheric Atomic Oxygen Source for Cleaning Smoke Damaged Art Objects

    Science.gov (United States)

    Banks, Bruce A.; Rutledge, Sharon K.; Norris, Mary Jo

    1998-01-01

    Soot and other carbonaceous combustion products deposited on the surfaces of porous ceramic, stone, ivory and paper can be difficult to remove and can have potentially unsatisfactory results using wet chemical and/or abrasive cleaning techniques. An atomic oxygen source which operates in air at atmospheric pressure, using a mixture of oxygen and helium, has been developed to produce an atomic oxygen beam which is highly effective in oxidizing soot deposited on surfaces by burning candles made of paraffin, oil or rendered animal fat. Atomic oxygen source operating conditions and the results of cleaning soot from paper, gesso, ivory, limestone and water color-painted limestone are presented,

  2. Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

    Directory of Open Access Journals (Sweden)

    Christophe Waterlot

    2012-01-01

    Full Text Available Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2 method and the high-speed self-reversal method (HSSR method. Regarding the preliminary results obtained with synthetic solutions, the D2 method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

  3. Survey of content of cadmium, calcium, chromium, copper, iron, lead, magnesium, manganese, mercury, sodium and zinc in chamomile and green tea leaves by electrothermal or flame atomizer atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Prkić Ante

    2018-03-01

    Full Text Available Due to the simplicity of tea preparation (pouring hot water onto different dried herbs and its high popularity as a beverage, monitoring and developing a screening methodology for detecting the metal content is very important. The concentrations of Cd, Ca, Cr, Cu, Fe, Pb, Mg, Mn, Hg, Na and Zn in 8 samples of green tea (Camellia sinesis and in 11 samples chamomile (Matricaria chamomilla L. purchased both at local herbal pharmacies and supermarkets were determined using electrothermal atomizer atomic absorption spectrometry (ETAAS and flame atomizer atomic absorption spectrometry (FAAS. The found concentrations in chamomile were: Cd (0.008 – 284 mg kg−1, Ca (2.42 – 6.29%, Cr (0.91 – 6.92 mg kg−1, Cu (6.27 – 11.39 mg kg−1, Fe (133.5 – 534 mg kg−1, Pb (0.561 – 1.277 mg kg−1, Mg (2.27 – 3.73%, Mn (62.2 – 165.6 mg kg−1, Hg (0.660 – 1.346 μg kg−1, Na (0.91 – 1.28% and Zn (63.37 – 108.5 mg kg−1, in green tea Cd (36.29 – 202.1 mg kg−1, Ca (2.77 – 6.40%, Cr (1.520 – 5.278 mg kg−1, Cu (9.354 – 22.56 mg kg−1, Fe (162.6 – 513.3 mg kg−1, Pb (1.808 – 4.770 mg kg−1, Mg (1.41 – 2.62 %, Mn (1.147 – 1.729 g kg−1, Hg (1.045 – 2.802 μg kg−1, Na (0.44 – 0.98% and Zn (30.65 – 115.6 mg kg−1, respectively. Principal Component Analysis (PCA was applied to identify factors (soil, climate and country of origin influencing the content of the measured elements in herbal samples. The proposed methodology developed in this work was successfully applied to the detection of metals in herbal samples. The analysis showed that the content of toxic metals in green tea samples was significantly higher and very close to the maximum dose recommended by the World Health Organization (WHO.

  4. On-line preconcentration using a resin functionalized with 3,4-dihydroxybenzoic acid for the determination of trace elements in biological samples by thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Lemos, Valfredo A.; Bezerra, Marcos A.; Amorim, Fabio A.C.

    2008-01-01

    In the present paper, an on-line preconcentration procedure for determination of cadmium, copper and zinc by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is proposed. Amberlite XAD-4 functionalized with 3,4-dihydroxybenzoic acid (XAD4-DHB) packed in a minicolumn was used as sorbent material. The metals were retained on the XAD-DHB resin, from which it could be eluted directly to the thermospray flame furnace system. The detection limits were 28 (Cd), 100 (Cu) and 77 ng L -1 (Zn) for 60 s preconcentration time, at a sample flow rate of 7.0 mL min -1 . Enrichment factors were 102, 91 and 62, for cadmium, copper and zinc, respectively. The procedure has been applied successfully to metal determination in biological standard reference materials

  5. Note: A versatile radio-frequency source for cold atom experiments

    Energy Technology Data Exchange (ETDEWEB)

    Li, Na; Wu, Yu-Ping; Min, Hao; Yang, Tao; Jiang, Xiao, E-mail: jiangx@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-08-15

    A radio-frequency (RF) source designed for cold atom experiments is presented. The source uses AD9858, a direct digital synthesizer, to generate the sine wave directly, up to 400 MHz, with sub-Hz resolution. An amplitude control circuit consisting of wideband variable gain amplifier and high speed digital to analog converter is integrated into the source, capable of 70 dB off isolation and 4 ns on-off keying. A field programmable gate array is used to implement a versatile frequency and amplitude co-sweep logic. Owing to modular design, the RF sources have been used on many cold atom experiments to generate various complicated RF sequences, enriching the operation schemes of cold atoms, which cannot be done by standard RF source instruments.

  6. Fundamental atomic collisional processes in negative ion sources for H-

    International Nuclear Information System (INIS)

    Crandall, D.H.; Barnett, C.F.

    1977-01-01

    The basic collision processes which create or destroy H - in gas-phase collisions like those which occur in ion sources are discussed. Cross sections are presented which show that, for known processes, destruction is generally more likely than production. One possible production mechanism (on which there is no data) is suggested, and isotope effects between hydrogen and deuterium are discussed

  7. Atoms

    International Nuclear Information System (INIS)

    Fuchs, Alain; Villani, Cedric; Guthleben, Denis; Leduc, Michele; Brenner, Anastasios; Pouthas, Joel; Perrin, Jean

    2014-01-01

    Completed by recent contributions on various topics (atoms and the Brownian motion, the career of Jean Perrin, the evolution of atomic physics since Jean Perrin, relationship between scientific atomism and philosophical atomism), this book is a reprint of a book published at the beginning of the twentieth century in which the author addressed the relationship between atomic theory and chemistry (molecules, atoms, the Avogadro hypothesis, molecule structures, solutes, upper limits of molecular quantities), molecular agitation (molecule velocity, molecule rotation or vibration, molecular free range), the Brownian motion and emulsions (history and general features, statistical equilibrium of emulsions), the laws of the Brownian motion (Einstein's theory, experimental control), fluctuations (the theory of Smoluchowski), light and quanta (black body, extension of quantum theory), the electricity atom, the atom genesis and destruction (transmutations, atom counting)

  8. [The glow discharge as an atomization and ionization source

    International Nuclear Information System (INIS)

    1990-01-01

    This is to summarize the research progress in this project at the University of Florida over the past 13 months. In keeping with the directions of the Federal Demonstration Project, the report will be brief, presenting an overview of the major findings. We have continued the study of the glow discharge, primarily as an ionization source for elemental analysis. Glow discharge interest continues to grow in the analytical chemistry community as evidenced by the number of special symposia at major conferences, by the new researchers entering the field, and by the introduction of new instrumentation. There is little doubt that glow discharge mass spectrometry, for example, is now a major technique in the elemental analysis of solids

  9. Evaluation of cadmium, lead, copper, iron and zinc in Turkish dietary vegetable oils and olives using electrothermal and flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Acar, Orhan

    2012-10-01

    Full Text Available The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS using an Sc + Ir + NH4H2PO4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS after microwave digestion. The pyrolysis and atomization temperatures of Cd, Pb and Cu in sample solutions with and without the modifier mixture were investigated. The limits of detection (LOD for analytes found are 0.1, 0.6, 0.9, 15.0 and 12.0 μg L–1 for Cd, Cu, Pb, Fe and Zn, respectively. The accuracy of the procedure proposed was confirmed by analyzing bovine liver 1577b standard reference material (SRM and a spiked sample solution. The results of the analytes found were compared with certified and added values. The relative standard deviations of the analytes found were lower than 7% and the percent of recoveries obtained ranges from 96 to 101%. The Sc + Ir + NH4H2PO4 mixture proposed was applied for the determination of Cd, Pb and Cu in oils and olives. The results of analytes found in the samples were compared with international and national food quality guidelines as well as with literature values.

    Se han determinado los metales Cd, Cu, Pb, Fe y Zn en aceites vegetales comestibles (soja, girasol, flores, nueces, maíz y aceite de oliva y aceitunas (aceitunas-1, negra, verde, negra machacadas con semillas y verde machacadas con semillas mediante espectrometría de absorción atómica electrotérmica (ETAAS utilizando como modificador químico la mezcla Sc + Ir + NH4H2PO4 y mediante espectrometría de absorción atómica de llama (FAAS tras digestión con microondas. Se estudiaron las temperaturas de pirólisis y atomización para Cd

  10. Development of a Supersonic Atomic Oxygen Nozzle Beam Source for Crossed Beam Scattering Experiments

    Science.gov (United States)

    Sibener, S. J.; Buss, R. J.; Lee, Y. T.

    1978-05-01

    A high pressure, supersonic, radio frequency discharge nozzle beam source was developed for the production of intense beams of ground state oxygen atoms. An efficient impedance matching scheme was devised for coupling the radio frequency power to the plasma as a function of both gas pressure and composition. Techniques for localizing the discharge directly behind the orifice of a water-cooled quartz nozzle were also developed. The above combine to yield an atomic oxygen beam source which produces high molecular dissociation in oxygen seeded rare gas mixtures at total pressures up to 200 torr: 80 to 90% dissociation for oxygen/argon mixtures and 60 to 70% for oxygen/helium mixtures. Atomic oxygen intensities are found to be greater than 10{sup 17} atom sr{sup -1} sec{sup -1}. A brief discussion of the reaction dynamics of 0 + IC1 ..-->.. I0 + C1 is also presented.

  11. Study of the Dissociative Processes in O_2 Discharges. Development of an Atomic Oxygen Beam Source

    International Nuclear Information System (INIS)

    Pagnon, Daniel

    1992-01-01

    The first part of this work is devoted to the study of dissociative processes in an oxygen glow discharge at low pressure (0,1-5 Torr, 1-80 mA). The kinetics of oxygen atoms has been determined supported by the measurements of atomic concentrations by VUV absorption spectroscopy and actinometry. The reaction coefficients for dissociative excitation and direct excitation of oxygen atoms have been calculated using the cross sections of the literature and a previously calculated EEDF. It has been demonstrated that dissociative excitation is negligible in respect with direct excitation for dissociation rates smaller than 2,5 %. An upper limit of 20 % for dissociative rates is observed. This limit has been explained by the increase of the atomic recombination at the discharge wall with increasing wall temperature. Using all these results, we have designed and optimized a source of oxygen atoms which has then been adapted on a MBE device. The spatial distribution of the atomic density has been measured in molecular jet by laser induced fluorescence (LIF) and Resonant Multi-Photon Ionization (RMPI). A stimulated emission has been evidenced and the coefficient for this process evaluated. A model for the effusion of atoms has been developed from which the flow of atoms on the sample can be predicted. This source has already been used in industrial MBE devices for in-situ oxidation of copper films, superconductors, and substrates for VLSI high speed applications. The methodology of this work and the diagnostics developed can be applied to other kinds of discharges, of other molecular gases, to design sources of atoms for the treatment of large area samples. (author) [fr

  12. Research in atomic and applied physics using a 6-GeV synchrotron source

    International Nuclear Information System (INIS)

    Jones, K.W.

    1985-12-01

    The Division of Atomic and Applied Physics in the Department of Applied Science at Brookhaven National Laboratory conducts a broad program of research using ion beams and synchrotron radiation for experiments in atomic physics and nuclear analytical techniques and applications. Many of the experiments would benefit greatly from the use of high energy, high intensity photon beams from a 6-GeV synchrotron source. A survey of some of the specific scientific possibilities is presented

  13. Structure of diffusion flames from a vertical burner

    Science.gov (United States)

    Mark A. Finney; Dan Jimenez; Jack D. Cohen; Isaac C. Grenfell; Cyle Wold

    2010-01-01

    Non-steady and turbulent flames are commonly observed to produce flame contacts with adjacent fuels during fire spread in a wide range of fuel bed depths. A stationary gas-fired burner (flame wall) was developed to begin study of flame edge variability along an analagous vertical fuel source. This flame wall is surrogate for a combustion interface at the edge of a deep...

  14. Optimization of the performance of rf transitions for the TUNL atomic beam polarized ion source

    International Nuclear Information System (INIS)

    Crosson, E.R.; Clegg, T.B.; Karwowski, H.J.; Lemieux, S.K.

    1991-01-01

    We have utilized the spin-dependence of the cross section for electron impact ionization of H 0 and D 0 atoms in the ionizer of our atomic beam polarized ion source to study the performance of the rf transitions which provide the nuclear polarization of the atomic beam. Switching the rf transitions on and off modulates the output polarized current. This modulation is observed using a lock-in amplifier and provides a fast and reliable method for optimization of transition unit parameters. (orig.)

  15. AtomicJ: An open source software for analysis of force curves

    Science.gov (United States)

    Hermanowicz, Paweł; Sarna, Michał; Burda, Kvetoslava; Gabryś, Halina

    2014-06-01

    We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh.

  16. AtomicJ: An open source software for analysis of force curves

    International Nuclear Information System (INIS)

    Hermanowicz, Paweł; Gabryś, Halina; Sarna, Michał; Burda, Kvetoslava

    2014-01-01

    We present an open source Java application for analysis of force curves and images recorded with the Atomic Force Microscope. AtomicJ supports a wide range of contact mechanics models and implements procedures that reduce the influence of deviations from the contact model. It generates maps of mechanical properties, including maps of Young's modulus, adhesion force, and sample height. It can also calculate stacks, which reveal how sample's response to deformation changes with indentation depth. AtomicJ analyzes force curves concurrently on multiple threads, which allows for high speed of analysis. It runs on all popular operating systems, including Windows, Linux, and Macintosh

  17. A novel lead imprinted polymer as the selective solid phase for extraction and trace detection of lead ions by flame atomic absorption spectrophotometry: Synthesis, characterization and analytical application

    Directory of Open Access Journals (Sweden)

    Homeira Ebrahimzadeh

    2017-05-01

    Full Text Available A novel ion imprinted polymer as the selective solid phase combined with flame atomic absorption spectrometry (FAAS was applied for preconcentration and determination of lead in real samples. In the first step, Pb(II-IIP was synthesized by copolymerization of 2-vinyl pyridine as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, 2,2-azobisisobutyronitrile as the initiator that imprinted with Pb(II as the template ion, 2-amino pyridine as the ligand. Subsequently, the imprinted Pb(II was completely removed by leaching the dried and powdered imprinted polymer with HCl (2 mol L−1. This polymer was characterized by Fourier Transform Infrared (FT-IR spectrometer. The effect of different variables on the extraction efficiency such as type and volume of eluent for extraction, solution’s pH for adsorption, sorption and desorption times was evaluated. Under the optimum conditions: type of eluent, HCl (2 mol L−1; volume of eluent, 5 mL; solution’s pH for sorption, 5; sorption time, 90 min; desorption time, 125 min and breakthrough volume of 750 mL were obtained. Preconcentration factor of the method was about 150. The limit of detection was obtained 0.75 μg L−1 and a dynamic linear range (DLR of 3–150 μg L−1 was found. The maximum sorption retention capacity of Pb(II ions on the imprinted polymer was 85.6 mg g−1. The prepared ion-imprinted polymer particles have an increased selectivity toward Pb(II ions over a range of competing metal ions with the same charge and similar ionic radius. Performance of the present method was evaluated for extraction and determination of Pb(II in water samples at microgram per liter concentration and satisfactory results were obtained (RSD = 2.7%.

  18. A solid phase extraction procedure for the determination of Cd(II) and Pb(II) ions in food and water samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Daşbaşı, Teslima; Saçmacı, Şerife; Ülgen, Ahmet; Kartal, Şenol

    2015-05-01

    A relatively rapid, accurate and precise solid phase extraction method is presented for the determination of cadmium(II) and lead(II) in various food and water samples. Quantitation is carried out by flame atomic absorption spectrometry (FAAS). The method is based on the retention of the trace metal ions on Dowex Marathon C, a strong acid cation exchange resin. Some important parameters affecting the analytical performance of the method such as pH, flow rate and volume of the sample solution; type, concentration, volume, flow rate of the eluent; and matrix effects on the retention of the metal ions were investigated. Common coexisting ions did not interfere on the separation and determination of the analytes. The detection limits (3 σb) for Cd(II) and Pb(II) were found as 0.13 and 0.18 μg L(-1), respectively, while the limit of quantification values (10 σb) were computed as 0.43 and 0.60 μg L(-1) for the same sequence of the analytes. The precision (as relative standard deviation was lower than 4% at 5 μg L(-1) Cd(II) and 10 μg L(-1) Pb(II) levels, and the preconcentration factor was found to be 250. The accuracy of the proposed procedure was verified by analysing the certified reference materials, SPS-WW2 Batch 108 wastewater level 2 and INCT-TL-1 tea leaves, with the satisfactory results. In addition, for the accuracy of the method the recovery studies (⩾ 95%) were carried out. The method was applied to the determination of the analytes in the various natural waters (lake water, tap water, waste water with boric acid, waste water with H2SO4) and food samples (pomegranate flower, organic pear, radish leaf, lamb meat, etc.), and good results were obtained. While the food samples almost do not contain cadmium, they have included lead at low levels of 0.13-1.12 μg g(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Ion Imprinted Polymer for Preconcentration and Determination of Ultra-Trace Cadmium, Employing Flow Injection Analysis with Thermo Spray Flame Furnace Atomic Absorption Spectrometry.

    Science.gov (United States)

    do Lago, Ayla Campos; Marchioni, Camila; Mendes, Tássia Venga; Wisniewski, Célio; Fadini, Pedro Sergio; Luccas, Pedro Orival

    2016-11-01

    This work proposes a preconcentration method using an ion imprinted polymer (IIP) for determination of cadmium, in several samples, employing a mini-column filled with the polymer coupled into a flow injection analysis system with detection by thermospray flame furnace atomic absorption spectrometry (FIA-TS-FF-AAS). The polymer was synthesized via bulk using methacrylic acid and vinylimidazole as a functional monomer. For the FIA system initial assessment, the variables: pH, eluent concentration and buffer concentration were studied, employing a 23 full factorial design. To obtain the optimum values for each significant variable, a Doehlert matrix was employed. After the optimization conditions as: pH 5.8, eluent (HNO3) concentration of 0.48 mol L -1 and buffer concentration of 0.01 mol L -1 , were adopted. The proposed method showed a linear response in the range of 0.081-10.0 μg L -1 , limits detection and quantification of 0.024 and 0.081 μg L -1 , respectively; preconcentration factor of 165, consumptive index of 0.06 mL, concentration efficiency 132 min -1 , and frequency of readings equal to 26 readings h -1 The accuracy was checked by analysis of certified reference materials for trace metals and recovery tests. The obtained results were in agreement with 95% confidence level (t-test). The method was adequate to apply in samples of: jewelry (earrings) (2.38 ± 0.28 μg kg -1 ), black tea (1.09 ± 0.15 μg kg -1 ), green tea (3.85 ± 0.13 μg kg -1 ), cigarette tobacco (38.27 ± 0.22 μg kg -1 ), and hair (0.35 ± 0.02 μg kg -1 ). © The Author(s) 2016.

  20. Production of hollow atoms by high brightness x-ray sources and its applications

    International Nuclear Information System (INIS)

    Moribayashi, Kengo

    2004-01-01

    We study x-ray emissions from the (multi-)inner-shell states and hollow atoms of Si ions excited by high intensity x-ray sources. It is found that the x-ray number from multi-inner-shell excited states (1s 2 2s 2 2p k 3s 2 3p 2 , k=1-4) and hollow atoms (1s 2 2s 2 3p 2 ) is affected greatly by the high intensity short-pulse x-rays and little by weak intensity post-long pulse x-rays. The ratio of the x-ray intensities from hollow atoms to those from the multi-inner-shell excited states becomes almost independent of the pulses and dependent on the intensities of x-ray sources. This ratio may be used for the measurement of intensities of high intensity short pulse x-ray sources. (author)

  1. Mechanism of selenium hydride atomization, fate of free atoms and temperature distribution in an argon shielded, highly fuel-rich, hydrogen-oxygen diffusion micro-flame studied by atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    D'Ulivo, A.; Dědina, Jiří; Lampugnani, L.; Matoušek, Tomáš

    2002-01-01

    Roč. 17, č. 3 (2002), s. 253-257 ISSN 0267-9477 R&D Projects: GA ČR GA203/01/0453; GA ČR GA203/98/0754 Institutional research plan: CEZ:AV0Z4031919 Keywords : hydride atomization * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.250, year: 2002

  2. The Advanced Light Source: A new tool for research in atomic and molecular physics

    International Nuclear Information System (INIS)

    Schlachter, F.; Robinson, A.

    1991-04-01

    The Advanced Light Source at the Lawrence Berkeley Laboratory will be the world's brightest synchrotron radiation source in the extreme ultraviolet and soft x-ray regions of the spectrum when it begins operation in 1993. It will be available as a national user facility to researchers in a broad range of disciplines, including materials science, atomic and molecular physics, chemistry, biology, imaging, and technology. The high brightness of the ALS will be particularly well suited to high-resolution studies of tenuous targets, such as excited atoms, ions, and clusters. 13 figs., 4 tabs

  3. Molecular absorption spectrometry in flames and furnaces: A review

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, David J., E-mail: butcher@email.wcu.edu

    2013-12-04

    Graphical abstract: -- Highlights: •Theory and analytical considerations for molecular absorption spectrometry (MAS). •Critical review of low resolution MAS. •Critical review of the analytical performance of high-resolution continuum source (HR-CS) flame MAS. •Critical review of the analytical performance of HR-CS graphite furnace MAS. •Current status of HR-CS MAS and its future prospects for elemental analysis. -- Abstract: Molecular absorption spectrometry (MAS), originally developed in the 1970s, is a technique to determine non-metals in flames and graphite furnaces by monitoring the absorbance of diatomic molecules. Early studies employed low resolution instruments designed for line source atomic absorption, which provided a limited choice of analytical wavelengths, insufficient spectral resolution, and spectral interferences. However, the development of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) instrumentation has allowed the analysis of challenging samples for non-metals as well as some difficult elements to determine by AAS, such as aluminum and phosphorus. In this review, theory and analytical considerations for MAS are discussed. The principles and limitations of low resolution MAS are described, along with its applications. HR-CS AAS instrumentation is reviewed, emphasizing performance characteristics most relevant for MAS. Applications of flame and HR-CS GFMAS are reviewed, highlighting the most significant work to date. The paper concludes with an evaluation of the enhanced analytical capabilities provided by HR-CS MAS.

  4. A simple and fast method for assessment of the nitrogen–phosphorus–potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta, E-mail: anchieta@iq.unesp.br

    2014-11-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L{sup −1} N (r = 0.9994), 100–2000 mg L{sup −1} P (r = 0.9946), and 100–2500 mg L{sup −1} K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97–105% (NO{sub 3}{sup −}-N), 95–103% (NH{sub 4}{sup +}-N), 93–103% (urea-N), 99–108% (P), and 99–102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H{sub 2}O{sub 2} allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time.

  5. A simple and fast method for assessment of the nitrogen–phosphorus–potassium rating of fertilizers using high-resolution continuum source atomic and molecular absorption spectrometry

    International Nuclear Information System (INIS)

    Bechlin, Marcos André; Fortunato, Felipe Manfroi; Moutinho da Silva, Ricardo; Ferreira, Edilene Cristina; Gomes Neto, José Anchieta

    2014-01-01

    The determination of N, P, and K in fertilizers by high-resolution continuum source flame atomic and molecular absorption spectrometry is proposed. Under optimized conditions, measurements of the diatomic molecules NO and PO at 215.360 and 247.620 nm, respectively, and K using the wing of the alternative line at 404.722 nm allowed calibration curves to be constructed in the ranges 500–5000 mg L −1 N (r = 0.9994), 100–2000 mg L −1 P (r = 0.9946), and 100–2500 mg L −1 K (r = 0.9995). Commercial fertilizers were analyzed by the proposed method and the concentrations of N, P, and K were found to be in agreement with those obtained by Kjeldahl, spectrophotometric, and flame atomic emission spectrometry methods, respectively, at a 95% confidence level (paired t-test). A phosphate rock certified reference material (CRM) was analyzed and the results for P and K were in agreement with the reference values. Recoveries from spiked CRM were in the ranges 97–105% (NO 3 − -N), 95–103% (NH 4 + -N), 93–103% (urea-N), 99–108% (P), and 99–102% (K). The relative standard deviations (n = 12) for N, P, and K were 6, 4, and 2%, respectively. - Highlights: • A single technique is proposed to analyze NPK fertilizer. • HR-CS FAAS is proposed for the first time for N, P and K determination in fertilizers. • The method employs the same sample preparation and dilution for the three analytes. • Addition of H 2 O 2 allows analysis of fertilizers with different nitrogen species. • Proposal provides advantages over traditional methods in terms of cost and time

  6. Flames in vortices & tulip-flame inversion

    Science.gov (United States)

    Dold, J. W.

    This article summarises two areas of research regarding the propagation of flames in flows which involve significant fluid-dynamical motion [1]-[3]. The major difference between the two is that in the first study the fluid motion is present before the arrival of any flame and remains unaffected by the flame [1, 2] while, in the second study it is the flame that is responsible for all of the fluid dynamical effects [3]. It is currently very difficult to study flame-motion in which the medium is both highly disturbed before the arrival of a flame and is further influenced by the passage of the flame.

  7. Atom

    International Nuclear Information System (INIS)

    Auffray, J.P.

    1997-01-01

    The atom through centuries, has been imagined, described, explored, then accelerated, combined...But what happens truly inside the atom? And what are mechanisms who allow its stability? Physicist and historian of sciences, Jean-Paul Auffray explains that these questions are to the heart of the modern physics and it brings them a new lighting. (N.C.)

  8. Fast combustion waves and chemi-ionization processes in a flame initiated by a powerful local plasma source in a closed reactor

    Science.gov (United States)

    Artem'ev, K. V.; Berezhetskaya, N. K.; Kazantsev, S. Yu.; Kononov, N. G.; Kossyi, I. A.; Popov, N. A.; Tarasova, N. M.; Filimonova, E. A.; Firsov, K. N.

    2015-01-01

    Results are presented from experimental studies of the initiation of combustion in a stoichiometric methane–oxygen mixture by a freely localized laser spark and by a high-current multispark discharge in a closed chamber. It is shown that, preceding the stage of ‘explosive’ inflammation of a gas mixture, there appear two luminous objects moving away from the initiator along an axis: a relatively fast and uniform wave of ‘incomplete combustion’ under laser spark ignition and a wave with a brightly glowing plasmoid behind under ignition from high-current slipping surface discharge. The gas mixtures in both the ‘preflame’ and developed-flame states are characterized by a high degree of ionization as the result of chemical ionization (plasma density ne≈1012 cm−3) and a high frequency of electron–neutral collisions (νen≈1012 s−1). The role of chemical ionization in constructing an adequate theory for the ignition of a gas mixture is discussed. The feasibility of the microwave heating of both the preflame and developed-flame plasma, supplementary to a chemical energy source, is also discussed. PMID:26170426

  9. Production and transport chemistry of atomic fluorine in remote plasma source and cylindrical reaction chamber

    International Nuclear Information System (INIS)

    Gangoli, S P; Johnson, A D; Fridman, A A; Pearce, R V; Gutsol, A F; Dolgopolsky, A

    2007-01-01

    Increasingly, NF 3 -based plasmas are being used in semiconductor manufacturing to clean chemical vapour deposition (CVD) chambers. With advantages such as faster clean times, substantially lower emissions of gases having high global warming potentials, and reduced chamber damage, NF 3 plasmas are now favoured over fluorocarbon-based processes. Typically, a remote plasma source (RPS) is used to dissociate the NF 3 gas and produce atomic fluorine that etches the CVD residues from the chamber surfaces. However, it is important to efficiently transport F atoms from the plasma source into the process chamber. The current work is aimed at understanding and improving the key processes involved in the production and transport of atomic fluorine atoms. A zero-dimensional model of NF 3 dissociation and F production chemistry in the RPS is developed based on various known and derived plasma parameters. Additionally, a model describing the transport of atomic fluorine is proposed that includes both physical (diffusion, adsorption and desorption) and chemical processes (surface and three-body volume recombination). The kinetic model provides an understanding of the impact of chamber geometry, gas flow rates, pressure and temperature on fluorine recombination. The plasma-kinetic model is validated by comparing model predictions (percentage F atom density) with experimental results (etch rates)

  10. Solid phase extraction method for the determination of lead, nickel, copper and manganese by flame atomic absorption spectrometry using sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) in water samples

    International Nuclear Information System (INIS)

    Rekha, D.; Suvardhan, K.; Kumar, J. Dilip; Subramanyam, P.; Prasad, P. Reddy; Lingappa, Y.; Chiranjeevi, P.

    2007-01-01

    A novel column solid phase extraction procedure was developed for the determination of lead, nickel, copper and manganese in various water samples by flame atomic absorption spectrometry (FAAS) after preconcentration on sodium bispiperdine-1,1'-carbotetrathioate (Na-BPCTT) supported by Amberlite XAD-7. The sorbed element was subsequently eluted with 1 M nitric acid and the acid eluates are analysed by Flame atomic absorption spectrometry (FAAS). Various parameters such as pH, amount of adsorbent, eluent type and volume, flow-rate of the sample solution, volume of the sample solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH for the sorption of above mentioned metal ions was about 6.0 ± 0.2. The loading capacity of adsorbent for Pb, Cu, Ni and Mn were found to 28, 26, 22 and 20 x 10 -6 g/mL, respectively. The recoveries of lead, copper, nickel and manganese under optimum conditions were found to be 96.7-99.2 at the 95% confident level. The limit of detection was 3.0, 3.2, 2.8 and 3.6 x 10 -6 g/mL for lead, copper, nickel and manganese, respectively by applying a preconcentration factor 50. The proposed enrichment method was applied for metal ions in various water samples. The results were obtained are good agreement with reported method

  11. Atomic physics at the Argonne PII ECR [electron cyclotron resonance] Ion Source

    International Nuclear Information System (INIS)

    Dunford, R.W.; Berry, H.G.; Billquist, P.J.; Pardo, R.C.; Zabransky, B.J.; Bakke, E.; Groeneveld, K.O.; Hass, M.; Raphaelian, M.L.A.

    1987-01-01

    An atomic physics beam line has been set up at the Argonne PII ECR Ion Source. The source is on a 350-kV high-voltage platform which is a unique feature of particular interest in work on atomic collisions. We describe our planned experimental program which includes: measurement of state-selective electron-capture cross sections, studies of doubly-excited states, precision spectroscopy of few-electron ions, tests of quantum electrodynamics, and studies of polarization transfer using optically pumped polarized alkali targets. The first experiments will be measurements of cross sections for electron capture into specific nl subshells in ion-atom collisions. Our method is to observe the characteristic radiation emitted after capture using a VUV spectrometer. Initial data from these experiments are presented. 12 refs., 4 figs

  12. High energy-intensity atomic oxygen beam source for low earth orbit materials degradation studies

    International Nuclear Information System (INIS)

    Cross, J.B.; Blais, N.C.

    1988-01-01

    A high intensity (10 19 O-atoms/s-sr) high energy (5 eV) source of oxygen atoms has been developed that produces a total fluence of 10 22 O-atoms/cm 2 in less than 100 hours of continuous operation at a distance of 15 cm from the source. The source employs a CW CO 2 laser sustained discharge to form a high temperature (15,000 K) plasma in the throat of a 0.3-mm diameter nozzle using 3--8 atmospheres of rare gas/O 2 mixtures. Visible and infrared photon flux levels of 1 watt/cm 2 have been measured 15 cm downstream of the source while vacuum UV (VUV) fluxes are comparable to that measured in low earth orbit. The reactions of atomic oxygen with kapton, Teflon, silver, and various coatings have been studied. The oxidation of kapton (reaction efficiency = 3 /times/ 10/sup /minus/24/ cm /+-/ 50%) has an activation energy of 0.8 Kcal/mole over the temperature range of 25/degree/C to 100/degree/C at a beam energy of 1.5 eV and produces low molecular weight gas phase reaction products (H 2 O, NO, CO 2 ). Teflon reacts with ∼0.1--0.2 efficiency to that of kapton at 25/degree/C and both surfaces show a rug-like texture after exposure to the O-atom beam. Angular scattering distribution measurements of O-atoms show a near cosine distribution from reactive surfaces indicating complete accommodation of the translational energy with the surface while a nonreactive surface (nickel oxide) shows specular-like scattering with 50% accommodation of the translational energy with the surface. A technique for simple on orbit chemical experiments using resistance measurements of coated silver strips is described. 9 figs

  13. Atomic and molecular spectroscopy with optical-frequency-comb-referenced IR coherent sources

    International Nuclear Information System (INIS)

    Cancio, P.; Bartalini, S.; De Rosa, M.; Giusfredi, G.; Mazzotti, D.; Maddaloni, P.; Vitiello, M. S.; De Natale, P.

    2013-01-01

    We provide a review of progress in the development of metrological-grade measurements in atomic and molecular systems through the extension, in the mid-infrared and far-infrared range, of optical frequency combs (OFCs) and the introduction of new techniques and highly coherent sources. (authors)

  14. Analytical characteristics of a continuum-source tungsten coil atomic absorption spectrometer.

    Science.gov (United States)

    Rust, Jennifer A; Nóbrega, Joaquim A; Calloway, Clifton P; Jones, Bradley T

    2005-08-01

    A continuum-source tungsten coil electrothermal atomic absorption spectrometer has been assembled, evaluated, and employed in four different applications. The instrument consists of a xenon arc lamp light source, a tungsten coil atomizer, a Czerny-Turner high resolution monochromator, and a linear photodiode array detector. This instrument provides simultaneous multi-element analyses across a 4 nm spectral window with a resolution of 0.024 nm. Such a device might be useful in many different types of analyses. To demonstrate this broad appeal, four very different applications have been evaluated. First of all, the temperature of the gas phase was measured during the atomization cycle of the tungsten coil, using tin as a thermometric element. Secondly, a summation approach for two absorption lines for aluminum falling within the same spectral window (305.5-309.5 nm) was evaluated. This approach improves the sensitivity without requiring any additional preconcentration steps. The third application describes a background subtraction technique, as it is applied to the analysis of an oil emulsion sample. Finally, interference effects caused by Na on the atomization of Pb were studied. The simultaneous measurements of Pb and Na suggests that negative interference arises at least partially from competition between Pb and Na atoms for H2 in the gas phase.

  15. Use of a discharge in an hollow cathode as neutral atom source for resonant ionization mass spectrometry

    International Nuclear Information System (INIS)

    Berthoud, T.; Briand, A.; Khelifa, N.; Mauchien, P.

    1987-01-01

    The resonance ionization mass spectrometry in our laboratory is aimed at simplification of isotope measurements of elements present in mixtures and at measurement of very small isotopes. An atomization source which produces an atomic beam collimated from a discharge in a hollow cathode has been developed. First results of this spectrometry with an uranium atomic jet are presented [fr

  16. Critical review of soil contamination by polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs); concentrations, sources and congener profiles.

    Science.gov (United States)

    McGrath, Thomas J; Ball, Andrew S; Clarke, Bradley O

    2017-11-01

    Polybrominated diphenyl ethers (PBDEs) have been used in a broad array of polymeric materials such as plastics, foams, resins and adhesives to inhibit the spread of fires since the 1970s. The widespread environmental contamination and well documented toxic effects of PBDEs have led to bans and voluntary withdrawals in many jurisdictions. Replacement novel brominated flame retardants (NBFRs) have, however, exhibited many of the same toxic characteristics as PBDEs and appear to share similar environmental fate. This paper presents a critical review of the scientific literature regarding PBDE and NBFR contamination of surface soils internationally, with the secondary objective of identifying probable pollution sources. An evaluation of NBFR distribution in soil was also conducted to assess the suitability of the newer compounds as replacements for PBDEs, with respect to their land contamination potential. Principle production of PBDEs and NBFRs and their consequent use in secondary polymer manufacture appear to be processes with strong potential to contaminate surrounding soils. Evidence suggests that PBDEs and NBFRs are also released from flame retarded products during disposal via landfill, dumping, incineration and recycling. While the land application of sewage sludge represents another major pathway of soil contamination it is not considered in this review as it is extensively covered elsewhere. Both PBDEs and NBFRs were commonly detected at background locations including Antarctica and northern polar regions. PBDE congener profiles in soil were broadly representative of the major constituents in Penta-, Octa- and Deca-BDE commercial mixtures and related to predicted market place demand. BDE-209 dominated soil profiles, followed by BDE-99 and BDE-47. Although further research is required to gain baseline data on NBFRs in soil, the current state of scientific literature suggests that NBFRs pose a similar risk to land contamination as PBDEs. Copyright © 2017

  17. Occurrence and Source Effect of Novel Brominated Flame Retardants (NBFRs) in Soils from Five Asian Countries and Their Relationship with PBDEs.

    Science.gov (United States)

    Li, Wen-Long; Ma, Wan-Li; Zhang, Zi-Feng; Liu, Li-Yan; Song, Wei-Wei; Jia, Hong-Liang; Ding, Yong-Sheng; Nakata, Haruhiko; Minh, Nguyen Hung; Sinha, Ravindra Kumar; Moon, Hyo-Bang; Kannan, Kurunthachalam; Sverko, Ed; Li, Yi-Fan

    2017-10-03

    This paper presents the first comprehensive survey of 19 novel brominated flame retardants (NBFRs) in soil samples collected among five Asian countries. High variability in concentrations of all NBFRs was found in soils with the geometric mean (GM) values ranging from 0.50 ng/g dry weight (dw) in Vietnam to 540 ng/g dw in the vicinity of a BFR manufacturer in China. In urban, rural, and background locations, the GM concentrations of ∑ 19 NBFRs decreased in the order of Japan > South Korea > China > India > Vietnam. Correlations among different NBFR compounds were positive and statistically significant (p e-waste sites. For the first time, this study demonstrates a "point source fractionation effect" for NBFRs and PBDEs. The concentrations of all NBFRs and PBDEs were negatively and significantly correlated with the distance from BFR-related industrial and e-waste regions. Positive and significant correlation between population density and NBFR concentrations in soils was identified. Our study revealed that the primary sources effects were stronger than the secondary sources effects in controlling the levels and distribution of NBFRs and PBDEs in soils in these five Asian countries.

  18. Influence of soil composition in the determination of chromium by atomic absorption spectrometry with flame air / acetylene; Influencia de la composicion del suelo en la determinacion de cromo por espectrometria de absorcion atomica con llama aire/acetileno

    Energy Technology Data Exchange (ETDEWEB)

    Duran Sosa, Ibis; Granda Valdes, Mayra [Departamento de Quimica Analitica, Facultad de Quimica, Universidad de La Habana, La Habana (Cuba); Pomares Alfonso, Mario Simeon, E-mail: mpomares@imre.oc.uh.cu [Instituto de Ciencias y Tecnologia de Materiales, Universidad de La Habana, La Habana (Cuba)

    2014-07-01

    The Air-acetylene Flame Atomic Absorption determination of chromium is a complex task, being strongly influenced by sample composition and instrumental conditions. The objective of this work was to study the influence of Al, Ca, Fe, K, Mg, and Na on the absorption of chromium in the air-acetylene flame, both separately and combined in solution, when acetylene flow and burner height vary. Dissolutions of the mixtures simulated the composition of four soils from the Quibu River Basin in Havana, Cuba. Chromium absorption first increased and then decreased with increment of acetylene flow for shorter burner heights (∼ 2-4 mm); while a continuous increase was observed for larger heights (> 4 mm). This behavior was the same in the presence and absence of interfering chemical element, mentioned above. On the other hand, the dependence of the magnitude of the interference with acetylene flow and burner height was complex and dependent on the interfering element, particularly at larger heights where the behavior of Al was remarkably different. The interference of the four mixtures of Al, Ca, K, Fe, Mg and Na decreased in comparison to individual interfering effects and was less dependent on acetylene flow and burner height. Finally, a significant reduction of interference on chromium determination in soil samples was achieved by an adequate selection of acetylene flow and burner height.

  19. The Atomic, Molecular and Optical Science instrument at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, Ken R. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Department of Applied Physics, Stanford University, 348 Via Pueblo, Stanford, CA 94305 (United States); Bucher, Maximilian; Bozek, John D.; Carron, Sebastian; Castagna, Jean-Charles [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Coffee, Ryan [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Pulse Institute, Stanford University and SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Curiel, G. Ivan; Holmes, Michael; Krzywinski, Jacek; Messerschmidt, Marc; Minitti, Michael; Mitra, Ankush; Moeller, Stefan; Noonan, Peter; Osipov, Timur; Schorb, Sebastian; Swiggers, Michele; Wallace, Alexander; Yin, Jing [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Bostedt, Christoph, E-mail: bostedt@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Pulse Institute, Stanford University and SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-17

    A description of the Atomic, Molecular and Optical Sciences (AMO) instrument at the Linac Coherent Light Source is presented. Recent scientific highlights illustrate the imaging, time-resolved spectroscopy and high-power density capabilities of the AMO instrument. The Atomic, Molecular and Optical Science (AMO) instrument at the Linac Coherent Light Source (LCLS) provides a tight soft X-ray focus into one of three experimental endstations. The flexible instrument design is optimized for studying a wide variety of phenomena requiring peak intensity. There is a suite of spectrometers and two photon area detectors available. An optional mirror-based split-and-delay unit can be used for X-ray pump–probe experiments. Recent scientific highlights illustrate the imaging, time-resolved spectroscopy and high-power density capabilities of the AMO instrument.

  20. Temporal interference with frequency-controllable long photons from independent cold atomic sources

    Science.gov (United States)

    Qian, Peng; Gu, Zhenjie; Wen, Rong; Zhang, Weiping; Chen, J. F.

    2018-01-01

    The interference of single photons from independent sources is an essential tool in quantum information processing. However, the interfering of photons with long temporal states in a time-resolved manner has rarely been studied. This is because without transmitting spectral filters or coupling to a cavity mode single photons generated in traditional nonlinear crystals suffer from a short temporal profile below 1 ns. With spectral correlation maintained in the biphotons generated from spontaneous four-wave mixing process in cold atom clouds, here we demonstrate the temporal interference of two frequency-tunable long photons from two independent cold atomic sources. We observe and analyze the interference of frequency-mismatched photons, where the phenomenon of the quantum beat at megahertz separation is displayed. Our paper provides more details for the quantum beat of two independent narrow-band single photons, which may find potential application in frequency-encoded photonic qubits in quantum information processing.

  1. Quantum Interference between Autonomous Single-Photon Sources from Doppler-Broadened Atomic Ensemble

    OpenAIRE

    Jeong, Teak; Lee, Yoon-Seok; Park, Jiho; Kim, Heonoh; Moon, Han Seb

    2017-01-01

    To realize a quantum network based on quantum entanglement swapping, bright and completely autonomous sources are essentially required. Here, we experimentally demonstrate Hong-Ou-Mandel (HOM) quantum interference between two independent bright photon pairs generated via the spontaneous four-wave mixing in Doppler-broadened ladder-type 87Rb atoms. Bright autonomous heralded single photons are operated in a continuous-wave (CW) mode with no synchronization or supplemental filters. The four-fol...

  2. Highly efficient electron gun with a single-atom electron source

    International Nuclear Information System (INIS)

    Ishikawa, Tsuyoshi; Urata, Tomohiro; Cho, Boklae; Rokuta, Eiji; Oshima, Chuhei; Terui, Yoshinori; Saito, Hidekazu; Yonezawa, Akira; Tsong, Tien T.

    2007-01-01

    The authors have demonstrated highly collimated electron-beam emission from a practical electron gun with a single-atom electron source; ∼80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources such as a cold field emission gun and a Zr/O/W Schottky gun. At the pressure of less than 1x10 -9 Pa, the authors observed stable emission of 20 nA, which generates the specimen current of 5 pA required for scanning electron microscopes

  3. Atomic physics with high-brightness synchrotron x-ray sources

    International Nuclear Information System (INIS)

    Jones, K.W.; Johnson, B.M.; Meron, M.

    1985-11-01

    A description of atomic physics experiments that we intend to carry out at the National Synchrotron Light Source is given. Emphasis is given to work that investigates the properties of multiply charged ions. The use of a synchrotron storage ring for highly charged heavy ions is proposed as a way to produce high current beams which will make possible experiments to study the photoexcitation and ionization of multiply charged ions for the first time. Experiments along the same lines which are feasible at the proposed Advanced Light Source are considered briefly. 7 refs., 2 figs

  4. Contribution to diagnostics/prognostics of tuberculosis in children. I. New methods of assaying zinc and simultaneously copper and zinc in diluted sera by flame atomic-absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Luterotti Svjetlana

    2015-09-01

    Full Text Available In an attempt to provide a reliable status of metal ions in children, new methods of analysis of children’s sera are proposed. New flame atomic-absorption spectrometric (FAAS methods are simple, cost- and time-effective and, above all, labor-, reagent- and sample-saving. Two methods were suggested: method A for simultaneous determination of Cu and Zn from 5-fold diluted sera, and method B, for assaying zinc alone in 10-fold diluted samples. Both methods are based on a single-step sample pretreatment (deproteinization with 3 mol dm–3 HCl. Method A uses a single-step calibration with a mixed standard. The main advantage of method B is an additional reduction in sample consumption. Both methods were fully validated against reference methods. Accuracy, sensitivity and precision have proven them to be comparable to the reference methods in terms of analytical performance, and applicable to analyses of children’s sera.

  5. Solid phase extraction of ultra traces silver(I) using octadecyl silica membrane disks modified by 1,3-bis(2-cyanobenzene) triazene (CBT) ligand prior to determination by flame atomic absorption

    International Nuclear Information System (INIS)

    Rofouei, Mohammad Kazem; Payehghadr, Mahmood; Shamsipur, Mojtaba; Ahmadalinezhad, Asieh

    2009-01-01

    A simple, reliable and rapid method for preconcentration and determination of the ultra trace amount of silver using octadecyl silica membrane disk modified by a recently synthesized triazene ligand, 1,3-bis(2-cyanobenzene)triazene (CBT), and flame atomic absorption spectrometry is presented. Various parameters including pH of aqueous solution, flow rates, the amount of ligand and the type of stripping solvents were optimized. The breakthrough volume was greater than 1800 ml with an enrichment factor of more than 360 and 6.0 ng l -1 detection limit. The capacity of the membrane disks modified by 5 mg of the ligand was found to be 1070 μg of silver. The effects of various cationic interferences on the percent recovery of silver ion were studied. The method was successfully applied to the determination of silver ion in different samples, especially determination of ultra trace amount of silver in the presence of large amount of lead.

  6. Solid phase extraction of ultra traces silver(I) using octadecyl silica membrane disks modified by 1,3-bis(2-cyanobenzene) triazene (CBT) ligand prior to determination by flame atomic absorption

    Energy Technology Data Exchange (ETDEWEB)

    Rofouei, Mohammad Kazem, E-mail: rofouei@tmu.ac.ir [Faculty of Chemistry, Tarbiat Moalem University, Tehran (Iran, Islamic Republic of); Payehghadr, Mahmood [Department of Chemistry, Payame Noor University (PNU) (Iran, Islamic Republic of); Shamsipur, Mojtaba [Department of Chemistry, Razi University, Kermanshah (Iran, Islamic Republic of); Ahmadalinezhad, Asieh [Department of Chemistry, Lakehead University, Thunder Bay, Ontario P7B 5E1 (Canada)

    2009-09-15

    A simple, reliable and rapid method for preconcentration and determination of the ultra trace amount of silver using octadecyl silica membrane disk modified by a recently synthesized triazene ligand, 1,3-bis(2-cyanobenzene)triazene (CBT), and flame atomic absorption spectrometry is presented. Various parameters including pH of aqueous solution, flow rates, the amount of ligand and the type of stripping solvents were optimized. The breakthrough volume was greater than 1800 ml with an enrichment factor of more than 360 and 6.0 ng l{sup -1} detection limit. The capacity of the membrane disks modified by 5 mg of the ligand was found to be 1070 {mu}g of silver. The effects of various cationic interferences on the percent recovery of silver ion were studied. The method was successfully applied to the determination of silver ion in different samples, especially determination of ultra trace amount of silver in the presence of large amount of lead.

  7. Flame atomic absorption spectrometric determination of zinc, nickel, iron and lead in different matrixes after solid phase extraction on sodium dodecyl sulfate (SDS)-coated alumina as their bis (2-hydroxyacetophenone)-1, 3-propanediimine chelates

    International Nuclear Information System (INIS)

    Ghaedi, M.; Tavallali, H.; Shokrollahi, A.; Zahedi, M.; Montazerozohori, M.; Soylak, M.

    2009-01-01

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L -1 HNO 3 . The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  8. Development of an in situ solvent formation microextraction and preconcentration method based on ionic liquids for the determination of trace cobalt (II in water samples by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Jamali

    2017-02-01

    Full Text Available A simple in situ solvent formation microextraction (ISFME methodology based on the application of ionic liquid (IL as an extractant solvent and sodium hexafluorophosphate (NaPF6 as an ion-pairing agent was proposed for the preconcentration of the trace levels of cobalt ions. In this method cobalt was complexed with 2-(5-bromo-2-pyridylazo-5-diethylaminophenol (5-Br-PADAP and extracted into an ionic liquid phase. After phase separation, the enriched analyte in the final solution is determined by flame atomic absorption spectrometry (FAAS. Some effective factors that influence the microextraction efficiency were investigated and optimized. Under the optimum experimental conditions, the limit of detection and the enrichment factor were 0.97 μg L−1 and 50, respectively. The relative standard deviation (R.S.D. was obtained as 2.4%. The proposed method was assessed through the analysis of certified reference water and recovery experiments.

  9. Combined discrete nebulization and microextraction process for molybdenum determination by flame atomic absorption spectrometry (FAAS); Avaliacao da combinacao da nebulizacao discreta e processos de microextracao aplicados a determinacao de molibdenio por espectrometria de absorcao atomica com chama (FAAS)

    Energy Technology Data Exchange (ETDEWEB)

    Oviedo, Jenny A.; Jesus, Amanda M.D. de; Fialho, Lucimar L.; Pereira-Filho, Edenir R., E-mail: erpf@ufscar.br [Universidade Federal de Sao Carlos (UFSCar), SP (Brazil). Departamento de Quimica

    2014-04-15

    Simple and sensitive procedures for the extraction/preconcentration of molybdenum based on vortex-assisted solidified floating organic drop microextraction (VA-SFODME) and cloud point combined with flame absorption atomic spectrometry (FAAS) and discrete nebulization were developed. The influence of the discrete nebulization on the sensitivity of the molybdenum preconcentration processes was studied. An injection volume of 200 μ resulted in a lower relative standard deviation with both preconcentration procedures. Enrichment factors of 31 and 67 and limits of detection of 25 and 5 μ L{sup -1} were obtained for cloud point and VA-SFODME, respectively. The developed procedures were applied to the determination of Mo in mineral water and multivitamin samples. (author)

  10. The determination of the rare earth elements in naturally-occurring materials zy flame spectroscopy

    International Nuclear Information System (INIS)

    Watts, J.C.

    1975-01-01

    Because the quantitative collection of the rare-earth elements retains natural abundance ratios, adequate analytical methodology incorporates their individual sensitivities, and tolerates their mutual contamination. To achieve these ends, the sensitivities of 15 rare-earths in flame emission were determined in the unseparated nitrous oxide/acetylene flame, their mutual interference ascertained at practical concentrations, and useful emission lines selected for their determination in natural materials. Sources of atomic emission interference were extraneous in origin. Fe in the determination of Dy and Zr in the determination of Nd. Inter-element interferences of the rare-earth elements were minimal after wavelength selection and reduction of the spectral band width. For comparison, five rare earths were determined by flame AAS. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Katskov, Dmitri, E-mail: katskovda@tut.ac.za

    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 D{sub 2} 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

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

    International Nuclear Information System (INIS)

    Katskov, Dmitri

    2015-01-01

    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 D 2 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

  13. Spatial Multiplexing of Atom-Photon Entanglement Sources using Feedforward Control and Switching Networks.

    Science.gov (United States)

    Tian, Long; Xu, Zhongxiao; Chen, Lirong; Ge, Wei; Yuan, Haoxiang; Wen, Yafei; Wang, Shengzhi; Li, Shujing; Wang, Hai

    2017-09-29

    The light-matter quantum interface that can create quantum correlations or entanglement between a photon and one atomic collective excitation is a fundamental building block for a quantum repeater. The intrinsic limit is that the probability of preparing such nonclassical atom-photon correlations has to be kept low in order to suppress multiexcitation. To enhance this probability without introducing multiexcitation errors, a promising scheme is to apply multimode memories to the interface. Significant progress has been made in temporal, spectral, and spatial multiplexing memories, but the enhanced probability for generating the entangled atom-photon pair has not been experimentally realized. Here, by using six spin-wave-photon entanglement sources, a switching network, and feedforward control, we build a multiplexed light-matter interface and then demonstrate a ∼sixfold (∼fourfold) probability increase in generating entangled atom-photon (photon-photon) pairs. The measured compositive Bell parameter for the multiplexed interface is 2.49±0.03 combined with a memory lifetime of up to ∼51  μs.

  14. Optically pumped semiconductor lasers: Conception and characterization of a single mode source for Cesium atoms manipulation

    International Nuclear Information System (INIS)

    Cocquelin, B.

    2009-02-01

    Lasers currently used in atomic clocks or inertial sensors are suffering from a lack of power, narrow linewidth or compactness for future spatial missions. Optically pumped semiconductor lasers, which combine the approach of classical solid state lasers and the engineering of semiconductor laser, are considered here as a candidate to a metrological laser source dedicated to the manipulation of Cesium atoms in these instruments. These lasers have demonstrated high power laser emission in a circular single transverse mode, as well as single longitudinal mode emission, favoured by the semiconductor structure and the external cavity design. We study the definition and the characterization of a proper semiconductor structure for the cooling and the detection of Cesium atoms at 852 nm. A compact and robust prototype tunable on the Cesium D2 hyperfine structure is built. The laser frequency is locked to an atomic transition thanks to a saturated absorption setup. The emission spectral properties are investigated, with a particular attention to the laser frequency noise and the laser linewidth. Finally, we describe and model the thermal properties of the semiconductor structure, which enables the simulation of the laser power characteristic. The experimental parameters are optimised to obtain the maximum output power with our structure. Thanks to our analysis, we propose several ways to overcome these limitations, by reducing the structure heating. (authors)

  15. An atomic oxygen device based on PIG oxygen negative ion source

    International Nuclear Information System (INIS)

    Yu Jinxiang; Cai Minghui; Han Jianwei

    2008-01-01

    It is an important research subject for the spaceflight countries to conduct equivalent simulation of 5 eV atomic oxygen effects for the spaceflight material in low earth orbit. This paper introduces an apparatus used for producing atomic oxygen, which consists of a PIG ion source with permanent magnet, two electrodes extraction system, an electron deflector, an einzel lens, an ion decelerating electrode and a sample bracket. At present it has been used on the small debris accelerator in the Center for Space Science and Applied Research, Chinese Academy of Sciences, and the producing experiments of O - are carried out. 200-300μA of O - ions are extracted at the extraction voltage of 2-3 kV. The experiments for decelerating of O - ions and erosion of kapton foil are carried out also. Because of the target room used for both the atomic oxygen device and the small debris accelerator, the facility can be used for small debris impinging and atomic erosion for spaceflight materials simultaneously. (authors)

  16. A=225 implantation for $^{221}$Fr source for TRIUMF atom trap

    CERN Multimedia

    The FrPNC Collaboration is mounting an atom trap for parity violation experiments and precision spectroscopy on francium atoms at TRIUMF's ISAC facility. We would like to use ISOLDE's capability of simultaneously implanting A=225 (while another experiment runs online) to make a long-lived source feeding $^{221}$Fr for tests of the trap. $^{225}$Ra $\\beta$-decays to $^{225}$Ac, which then $\\alpha$-decays, producing 100 keV $^{221}$Fr t$_{1/2}$= 4.8 minute recoils. The implanted A=225 source would be shipped to TRIUMF, where it would be held for several minutes at a time a few mm from the same yttrium foil that normally receives the ISAC beam. SRIM calculations imply that 20% of the $^{221}$Fr will be implanted in a 1 cm diameter spot on the yttrium. Then the yttrium foil is moved to the trap and heated to release the Fr atoms, just as in normal ISAC online operation. A test implantation will be done at 10$^{7}$/sec production for 1 day, testing whether carbon cracking on the implantation foil in the mass separ...

  17. An experimental investigation into power broadening of the Na-D lines in a flame

    International Nuclear Information System (INIS)

    Calcar, R.A. van.

    1980-01-01

    Investigations are described aimed at the verification of the existence of power broadening in fluorescence, as predicted by theory in the case of a broadband excitation source. Measurements were performed on a vapour of sodium (Na) atoms in a pre-mixed H 2 -O 2 -Ar flame under 1 atm pressure. The easily excited first resonance (or D) lines of Na were chosen for the observation of power broadening in fluorescence. (Auth.)

  18. Informal proposal for an Atomic Physics Facility at the National Synchrotron Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Jones, K.W.; Johnson, B.M.; Meron, M.

    1986-01-01

    An Atomic Physics Facility (APF) for experiments that will use radiation from a superconducting wiggler on the NSLS X-13 port is described. The scientific justification for the APF is given and the elements of the facility are discussed. It is shown that it will be possible to conduct a uniquely varied set of experiments that can probe most aspects of atomic physics. A major component of the proposal is a heavy-ion storage ring capable of containing ions with energies of about 10 MeV/nucleon. The ring can be filled with heavy ions produced at the BNL MP Tandem Laboratory or from independent ion-source systems. A preliminary cost estimate for the facility is presented.

  19. Visualization of ionic wind in laminar jet flames

    KAUST Repository

    Park, Daegeun

    2017-07-03

    Electric field, when it is applied to hydrocarbon flames, generates ionic wind due to the electric body force on charge carrying species. Ionic wind has been shown to influence soot emission, propagation speed, and stability of flames; however, a detailed behavior of ionic wind and its effects on flames is still not clear. Here, we investigated the dynamic behaviors of flames and ionic wind in the presence of direct current (DC) and alternating current (AC) electric fields in nonpremixed and premixed jet flames with a jet nozzle placed between two parallel electrodes. We observed a skewed flame toward a lower potential electrode with DC and lower frequency AC (e.g., 10Hz) and a steady flame with higher frequencies AC (1000Hz), while we found that the ionic wind blew toward both the anode and cathode regardless of flame type (nonpremixed or premixed) or the source of the electric field (DC and AC).

  20. Experiment and Simulation of Autoignition in Jet Flames and its Relevance to Flame Stabilization and Structure

    KAUST Repository

    Al-Noman, Saeed M.

    2016-06-01

    Autoignition characteristics of pre-vaporized iso-octane, primary reference fuels, gasolines, and dimethyl ether (DME) have been investigated experimentally in a coflow with elevated temperature of air. With the coflow air at relatively low initial temperatures below autoignition temperature Tauto, an external ignition source was required to stabilize the flame. Non-autoignited lifted flames had tribrachial edge structures and their liftoff heights correlated well with the jet velocity scaled by the stoichiometric laminar burning velocity, indicating the importance of the edge propagation speed on flame stabilization balanced with local flow velocity. At high initial temperatures over Tauto, the autoignited flames were stabilized without requiring an external ignition source. The autoignited lifted flames exhibited either tribrachial edge structures or Mild combustion behaviors depending on the level of fuel dilution. For the iso-octane and n-heptane fuels, two distinct transition behaviors were observed in the autoignition regime from a nozzle-attached flame to a lifted tribrachial-edge flame and then a sudden transition to lifted Mild combustion as the jet velocity increased at a certain fuel dilution level. The liftoff data of the autoignited flames with tribrachial edges were analyzed based on calculated ignition delay times for the pre-vaporized fuels. Analysis of the experimental data suggested that ignition delay time may be much less sensitive to initial temperature under atmospheric pressure conditions as compared with predictions. For the gasoline fuels for advanced combustion engines (FACEs), and primary reference fuels (PRFs), autoignited liftoff data were correlated with Research Octane Number and Cetane Number. For the DME fuel, planar laser-induced fluorescence (PLIF) of formaldehyde (CH2O) and CH* chemiluminescence were visualized qualitatively. In the autoignition regime for both tribrachial structure and mild combustion, formaldehyde were found

  1. The new atomic act. Radiation exposure from radon and natural radiation sources in workplaces and the experience of surveillance

    International Nuclear Information System (INIS)

    Sinaglova, R.

    2018-01-01

    In this presentation the new atomic act approved in the Czech republic is analyzed from the point of view of irradiation from radon and natural radiation sources in workplaces. Experience of supervision are also discussed. (authors)

  2. Bright focused ion beam sources based on laser-cooled atoms

    Science.gov (United States)

    McClelland, J. J.; Steele, A. V.; Knuffman, B.; Twedt, K. A.; Schwarzkopf, A.; Wilson, T. M.

    2016-01-01

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga+ liquid metal ion source. In this review we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future. PMID:27239245

  3. Bright focused ion beam sources based on laser-cooled atoms

    Energy Technology Data Exchange (ETDEWEB)

    McClelland, J. J.; Wilson, T. M. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Steele, A. V.; Knuffman, B.; Schwarzkopf, A. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); zeroK NanoTech, Gaithersburg, Maryland 20878 (United States); Twedt, K. A. [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Maryland Nanocenter, University of Maryland, College Park, Maryland 20742 (United States)

    2016-03-15

    Nanoscale focused ion beams (FIBs) represent one of the most useful tools in nanotechnology, enabling nanofabrication via milling and gas-assisted deposition, microscopy and microanalysis, and selective, spatially resolved doping of materials. Recently, a new type of FIB source has emerged, which uses ionization of laser cooled neutral atoms to produce the ion beam. The extremely cold temperatures attainable with laser cooling (in the range of 100 μK or below) result in a beam of ions with a very small transverse velocity distribution. This corresponds to a source with extremely high brightness that rivals or may even exceed the brightness of the industry standard Ga{sup +} liquid metal ion source. In this review, we discuss the context of ion beam technology in which these new ion sources can play a role, their principles of operation, and some examples of recent demonstrations. The field is relatively new, so only a few applications have been demonstrated, most notably low energy ion microscopy with Li ions. Nevertheless, a number of promising new approaches have been proposed and/or demonstrated, suggesting that a rapid evolution of this type of source is likely in the near future.

  4. Xenon gas field ion source from a single-atom tip

    Science.gov (United States)

    Lai, Wei-Chiao; Lin, Chun-Yueh; Chang, Wei-Tse; Li, Po-Chang; Fu, Tsu-Yi; Chang, Chia-Seng; Tsong, T. T.; Hwang, Ing-Shouh

    2017-06-01

    Focused ion beam (FIB) systems have become powerful diagnostic and modification tools for nanoscience and nanotechnology. Gas field ion sources (GFISs) built from atomic-size emitters offer the highest brightness among all ion sources and thus can improve the spatial resolution of FIB systems. Here we show that the Ir/W(111) single-atom tip (SAT) can emit high-brightness Xe+ ion beams with a high current stability. The ion emission current versus extraction voltage was analyzed from 150 K up to 309 K. The optimal emitter temperature for maximum Xe+ ion emission was ˜150 K and the reduced brightness at the Xe gas pressure of 1 × 10-4 torr is two to three orders of magnitude higher than that of a Ga liquid metal ion source, and four to five orders of magnitude higher than that of a Xe inductively coupled plasma ion source. Most surprisingly, the SAT emitter remained stable even when operated at 309 K. Even though the ion current decreased with increasing temperature, the current at room temperature (RT) could still reach over 1 pA when the gas pressure was higher than 1 × 10-3 torr, indicating the feasibility of RT-Xe-GFIS for application to FIB systems. The operation temperature of Xe-SAT-GFIS is considerably higher than the cryogenic temperature required for the helium ion microscope (HIM), which offers great technical advantages because only simple or no cooling schemes can be adopted. Thus, Xe-GFIS-FIB would be easy to implement and may become a powerful tool for nanoscale milling and secondary ion mass spectroscopy.

  5. Hydrogen atom temperature measured with wavelength-modulated laser absorption spectroscopy in large scale filament arc negative hydrogen ion source

    International Nuclear Information System (INIS)

    Nakano, H.; Goto, M.; Tsumori, K.; Kisaki, M.; Ikeda, K.; Nagaoka, K.; Osakabe, M.; Takeiri, Y.; Kaneko, O.; Nishiyama, S.; Sasaki, K.

    2015-01-01

    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

  6. A polarized hydrogen/deuterium atomic beam source for internal target experiments

    International Nuclear Information System (INIS)

    Szczerba, D.; Buuren, L.D. van; Brand, J.F.J. van den; Bulten, H.J.; Ferro-Luzzi, M.; Klous, S.; Kolster, H.; Lang, J.; Mul, F.; Poolman, H.R.; Simani, M.C.

    2000-01-01

    A high-brightness hydrogen/deuterium atomic beam source is presented. The apparatus, previously used in electron scattering experiments with tensor-polarized deuterium (Ferro-Luzzi et al., Phys. Rev. Lett. 77 (1996) 2630; van den Brand et al., Phys. Rev. Lett. 78 (1997) 1235; Zhou et al., Phys. Rev. Lett. 82 (1998) 687; Bouwhuis et al., Phys. Rev. Lett. 82 (1999) 3755), was configured as a source for internal target experiments to measure single- and double-polarization observables, with either polarized hydrogen or vector/tensor polarized deuterium. The atomic beam intensity was enhanced by a factor of ∼2.5 by optimizing the Stern-Gerlach focusing system using high tip-field (∼1.5 T) rare-earth permanent magnets, and by increasing the pumping speed in the beam-formation chamber. Fluxes of (5.9±0.2)x10 16 1 H/s were measured in a diameter 12 mmx122 mm compression tube with its entrance at a distance of 27 cm from the last focusing element. The total output flux amounted to (7.6±0.2)x10 16 1 H/s

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

    International Nuclear Information System (INIS)

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

    2006-01-01

    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, L'vov 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 deg. 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

  8. 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

    International Nuclear Information System (INIS)

    Ribeiro, Anderson Schwingel; Vieira, Mariana Antunes; Furtado da Silva, Alessandra; Borges, Daniel L. Gallindo; Welz, Bernhard; Heitmann, Uwe; Curtius, Adilson Jose

    2005-01-01

    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 deg. C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 deg. 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

  9. Flame structure of methane inverse diffusion flame

    KAUST Repository

    Elbaz, Ayman M.

    2014-07-01

    This paper presents high speed images of OH-PLIF at 10. kHz simultaneously with 2D PIV (particle image velocimetry) measurements collected along the entire length of an inverse diffusion flame with circumferentially arranged methane fuel jets. For a fixed fuel flow rate, the central air jet Re was varied, leading to four air to fuel velocity ratios, namely Vr = 20.7, 29, 37.4 and 49.8. A double flame structure could be observed composed of a lower fuel entrainment region and an upper mixing and intense combustion region. The entrainment region was enveloped by an early OH layer, and then merged through a very thin OH neck to an annular OH layer located at the shear layer of the air jet. The two branches of this annular OH layer broaden as they moved downstream and eventfully merged together. Three types of events were observed common to all flames: breaks, closures and growing kernels. In upstream regions of the flames, the breaks were counterbalanced by flame closures. These breaks in OH signal were found to occur at locations where locally high velocity flows were impinging on the flame. As the Vr increased to 37.4, the OH layers became discontinuous over the downstream region of the flame, and these regions of low or no OH moved upstream. With further increases in Vr, these OH pockets act as flame kernels, growing as they moved downstream, and became the main mechanism for flame re-ignition. Along the flame length, the direction of the two dimensional principle compressive strain rate axis exhibited a preferred orientation of approximately 45° with respect to the flow direction. Moreover, the OH zones were associated with elongated regions of high vorticity. © 2013 Elsevier Inc.

  10. Ultrabright, narrow-band photon-pair source for atomic quantum memories

    Science.gov (United States)

    Tsai, Pin-Ju; Chen, Ying-Cheng

    2018-06-01

    We demonstrate an ultrabright, narrow-band and frequency-tunable photon-pair source based on cavity-enhanced spontaneous parametric down conversion (SPDC) which is compatible with atomic transition of rubidium D 2-line (780 nm) or cesium D 2-line (852 nm). With the pump beam alternating between a high and a low power phase, the output is switching between the optical parametric oscillator (OPO) and photon-pair generation mode. We utilize the OPO output light to lock the cavity length to maintain the double resonances of signal and idler, as well as to lock the signal frequency to cesium atomic transition. With a type-II phase matching and a double-passed pump scheme such that the cluster frequency spacing is larger than the SPDC bandwidth, the photon-pair output is in a nearly single-mode operation as confirmed by a scanning Fabry–Perot interferometer with its output detected by a photomultiplier. The achieved generation and detection rates are 7.24× {10}5 and 6142 s‑1 mW‑1, respectively. The correlation time of the photon pair is 21.6(2.2) ns, corresponding to a bandwidth of 2π × 6.6(6) MHz. The spectral brightness is 1.06× {10}5 s‑1 mW‑1 MHz‑1. This is a relatively high value under a single-mode operation with the cavity-SPDC scheme. The generated single photons can be readily used in experiments related to atomic quantum memories.

  11. On the Flame Height Definition for Upward Flame Spread

    OpenAIRE

    Consalvi, Jean L; Pizzo, Yannick; Porterie, Bernard; Torero, Jose L

    2007-01-01

    Flame height is defined by the experimentalists as the average position of the luminous flame and, consequently is not directly linked with a quantitative value of a physical parameter. To determine flame heights from both numerical and theoretical results, a more quantifiable criterion is needed to define flame heights and must be in agreement with the experiments to allow comparisons. For wall flames, steady wall flame experiments revealed that flame height may be define...

  12. Properties of plasma flames sustained by microwaves and burning hydrocarbon fuels

    International Nuclear Information System (INIS)

    Hong, Yong Cheol; Uhm, Han Sup

    2006-01-01

    Plasma flames made of atmospheric microwave plasma and a fuel-burning flame were presented and their properties were investigated experimentally. The plasma flame generator consists of a fuel injector and a plasma flame exit connected in series to a microwave plasma torch. The plasma flames are sustained by injecting hydrocarbon fuels into a microwave plasma torch in air discharge. The microwave plasma torch in the plasma flame system can burn a hydrocarbon fuel by high-temperature plasma and high atomic oxygen density, decomposing the hydrogen and carbon containing fuel. We present the visual observations of the sustained plasma flames and measure the gas temperature using a thermocouple device in terms of the gas-fuel mixture and flow rate. The plasma flame volume of the hydrocarbon fuel burners was more than approximately 30-50 times that of the torch plasma. While the temperature of the torch plasma flame was only 868 K at a measurement point, that of the diesel microwave plasma flame with the addition of 0.019 lpm diesel and 30 lpm oxygen increased drastically to about 2280 K. Preliminary experiments for methane plasma flame were also carried out, measuring the temperature profiles of flames along the radial and axial directions. Finally, we investigated the influence of the microwave plasma on combustion flame by observing and comparing OH molecular spectra for the methane plasma flame and methane flame only

  13. High-resolution continuum-source atomic absorption spectrometry: what can we expect?

    Directory of Open Access Journals (Sweden)

    Welz Bernhard

    2003-01-01

    Full Text Available A new instrumental concept has been developed for atomic absorption spectrometry (AAS, using a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator and a CCD array detector, providing a resolution of ~2 pm per pixel. Among the major advantages of the system are: i an improved signal-to-noise ratio because of the high intensity of the radiation source, resulting in improved photometric precision and detection limits; ii for the same reason, there are no more 'weak' lines, i.e. secondary lines can be used without compromises; iii new elements might be determined, for which no radiation source has been available; iv the entire spectral environment around the analytical line becomes 'visible', giving a lot more information than current AAS instruments; v the CCD array detector allows a truly simultaneous background correction close to the analytical line; vi the software is capable of storing reference spectra, e.g. of a molecular absorption with rotational fine structure, and of subtracting such spectra from the spectra recorded for a sample, using a least squares algorithm; vii although not yet realized, the system makes possible a truly simultaneous multi-element AAS measurement when an appropriate two-dimensional detector is used, as is already common practice in optical emission spectrometry; vii preliminary experiments have indicated that the instrumental concept could result in a more rugged analytical performance in the determination of trace elements in complex matrices.

  14. An open source/real-time atomic force microscope architecture to perform customizable force spectroscopy experiments.

    Science.gov (United States)

    Materassi, Donatello; Baschieri, Paolo; Tiribilli, Bruno; Zuccheri, Giampaolo; Samorì, Bruno

    2009-08-01

    We describe the realization of an atomic force microscope architecture designed to perform customizable experiments in a flexible and automatic way. Novel technological contributions are given by the software implementation platform (RTAI-LINUX), which is free and open source, and from a functional point of view, by the implementation of hard real-time control algorithms. Some other technical solutions such as a new way to estimate the optical lever constant are described as well. The adoption of this architecture provides many degrees of freedom in the device behavior and, furthermore, allows one to obtain a flexible experimental instrument at a relatively low cost. In particular, we show how such a system has been employed to obtain measures in sophisticated single-molecule force spectroscopy experiments [Fernandez and Li, Science 303, 1674 (2004)]. Experimental results on proteins already studied using the same methodologies are provided in order to show the reliability of the measure system.

  15. Application of a field flow preconcentration system with a minicolumn packed with amberlite XAD-4/1-(2-pyridylazo)-2-naphtol and a flow injection-flame atomic adsorption spectrometric system for lead determination in sea water

    International Nuclear Information System (INIS)

    Carmen Yebra, M. del; Rodriguez, L.; Puig, L.; Moreno-Cid, A.

    2002-01-01

    A field flow preconcentration technique involving a minicolumn containing Amberlite XAD-4 impregnated with the complexing agent 1-(2-pyridylazo)-2-naphthol was used to preconcentrate lead from seawater. Elution of retained lead on the minicolumns was performed by a flow-injection-flame atomic absorption spectrometric system. Factorial designs have been used to optimize the field flow preconcentration system and the flow injection elution process. Factors such as sample pH, sample flow-rate, eluent concentration and volume (hydrochloric acid), elution flow-rate and minicolumn diameter were considered. The results suggest that the sample flow-rate and the eluent volume are statistically significant factors. The detection limit (3σ) of the procedure was 5 ng/L for a sample volume of 1000 ml. The precision (expressed as relative standard deviation) for eleven independent determinations reached values of 4.0-3.1 % in lead solutions of 50-200 ng/L. This procedure has been successfully applied to the determination of lead in seawater from Galicia (Spain). (author)

  16. Cloud point extraction of copper, lead, cadmium, and iron using 2,6-diamino-4-phenyl-1,3,5-triazine and nonionic surfactant, and their flame atomic absorption spectrometric determination in water and canned food samples.

    Science.gov (United States)

    Citak, Demirhan; Tuzen, Mustafa

    2012-01-01

    A cloud point extraction procedure was optimized for the separation and preconcentration of lead(II), cadmium(II), copper(II), and iron(III) ions in various water and canned food samples. The metal ions formed complexes with 2,6-diamino-4-phenyl-1,3,5-triazine that were extracted by surfactant-rich phases in the nonionic surfactant Triton X-114. The surfactant-rich phase was diluted with 1 M HNO3 in methanol prior to its analysis by flame atomic absorption spectrometry. The parameters affecting the extraction efficiency of the proposed method, such as sample pH, complexing agent concentration, surfactant concentration, temperature, and incubation time, were optimized. LOD values based on three times the SD of the blank (3Sb) were 0.38, 0.48, 1.33, and 1.85 microg/L for cadmium(II), copper(II), lead(II), and iron(III) ions, respectively. The precision (RSD) of the method was in the 1.86-3.06% range (n=7). Validation of the procedure was carried out by analysis of National Institute of Standards and Technology Standard Reference Material (NIST-SRM) 1568a Rice Flour and GBW 07605 Tea. The method was applied to water and canned food samples for determination of metal ions.

  17. Solid-phase extraction of copper(II) in water and food samples using silica gel modified with bis(3-aminopropyl)amine and determination by flame atomic absorption spectrometry.

    Science.gov (United States)

    Cagirdi, Duygu; Altundag, Hüseyin; Imamoglu, Mustafa; Tuzen, Mustafa

    2014-01-01

    A simple and selective separation and preconcentration method was developed for the determination of Cu(ll) ions. This method is based on adsorption of Cu(ll) ions from aqueous solution on a bis(3-aminopropyl)amine modified silica gel column and flame atomic absorption spectrometric determination after desorption. Various analytical parameters such as pH, type of eluent solution and its volume, flow rate of sample and eluent, and sample volume were optimized. Effects of some cation, anion, and transition metal ions on the recoveries of Cu(ll) ions were also investigated. Cu(ll) ions were quantitatively recovered at pH 6; 5.0 mL of 2 M HCI was used as the eluent. The preconcentration factor was found to be 150. The LOD was 0.12 microg/L for Cu(ll). The accuracy of the method was confirmed by analysis of Tea Leaves (INCT-TL-1) and Fish Protein (DORM-3) certified reference materials. The optimized method was applied to various water and food samples for the determination of Cu(ll).

  18. A new ultrasonic-assisted cloud-point-extraction procedure for pre-concentration and determination of ultra-trace levels of copper in selected beverages and foods by flame atomic absorption spectrometry.

    Science.gov (United States)

    Altunay, Nail; Gürkan, Ramazan; Orhan, Ulaş

    2015-01-01

    A new ultrasonic-assisted cloud-point-extraction (UA-CPE) method was developed for the pre-concentration of Cu(II) in selected beverage and food samples prior to flame atomic absorption spectrometric (FAAS) analysis. For this purpose, Safranin T was used as an ion-pairing reagent based on charge transfer in the presence of oxalate as the primary chelating agent at pH 10. Non-ionic surfactant, poly(ethyleneglycol-mono-p-nonylphenylether) (PONPE 7.5) was used as an extracting agent in the presence of NH4Cl as the salting out agent. The variables affecting UA-CPE efficiency were optimised in detail. The linear range for Cu(II) at pH 10 was 0.02-70 µg l(-)(1) with a very low detection limit of 6.10 ng l(-)(1), while the linear range for Cu(I) at pH 8.5 was 0.08-125 µg l(-)(1) with a detection limit of 24.4 ng l(-)(1). The relative standard deviation (RSD %) was in the range of 2.15-4.80% (n = 5). The method was successfully applied to the quantification of Cu(II), Cu(I) and total Cu in selected beverage and food samples. The accuracy of the developed method was demonstrated by the analysis of two standard reference materials (SRMs) as well as recoveries of spiked samples.

  19. Flame atomic absorption spectrometric determination of trace amounts of Pb(II) and Cr(III) in biological, food and environmental samples after preconcentration by modified nano-alumina

    International Nuclear Information System (INIS)

    Afkhami, A.; Madrakian, T.; Saber-Tehrani, M.; Bagheri, H.

    2011-01-01

    A new solid-phase extraction sorbent was used for the preconcentration of Pb(II) and Cr(III) ions prior to their determination by flame atomic absorption spectrometry. It was prepared by immobilization of 2,4-dinitrophenylhydrazine on nano-alumina coated with sodium dodecyl sulfate. The sorbent was characterized by scanning electron microscopy, N 2 adsorption and Fourier transform infrared spectrometry, and used for preconcentration and separation of Pb(II) and Cr(III) from aqueous solutions. The ions on the sorbent were eluted with a mixture of nitric acid and methanol. The effects of sample pH, flow rates of samples and eluent, type of eluent, breakthrough volume and potentially interfering ions were studied. Linearity is maintained between 1.2 and 350 μg L -1 of Pb(II), and between 2.4 and 520 μg L -1 of Cr(III) for an 800-mL sample. The detection limit (3 s, N=10) for Pb(II) and Cr(III) ions is 0.43 and 0.55 μg L -1 , respectively, and the maximum preconcentration factor is 267. The method was successfully applied to the evaluation of these trace and toxic metals in various water, food, industrial effluent and urine samples. (author)

  20. On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry.

    Science.gov (United States)

    Ensafi, Ali A; Shiraz, A Zendegi

    2008-02-11

    Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL(-1) Pb(II). The adsorption capacity of the solid phase was 0.20mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method.

  1. Modified Activated Carbon Prepared from Acorn Shells as a New Solid-Phase Extraction Sorbent for the Preconcentration and Determination of Trace Amounts of Nickel in Food Samples Prior to Flame Atomic Absorption Spectrometry.

    Science.gov (United States)

    Ebrahimi, Bahram

    2017-03-01

    A new solid-phase extraction (SPE) sorbent was introduced based on acidic-modified (AM) activated carbon (AC) prepared from acorn shells of native oak trees in Kurdistan. Hydrochloric acid (15%, w/w) and nitric acid (32.5%, w/w) were used to condition and modify AC. The IR spectra of AC and AM-AC showed that AM lead to the formation of increasing numbers of acidic functional groups on AM-AC. AM-AC was used in the SPE method for the extraction and preconcentration of Ni+2 prior to flame atomic absorption spectrometric determination at ng/mL levels in model and real food samples. Effective parameters of the SPE procedure, such as the pH of the solutions, sorbent dosage, extraction time, sample volume, type of eluent, and matrix ions, were considered and optimized. An enrichment factor of 140 was obtained. The calibration curve was linear with an R2 of 0.997 in the concentration range of 1-220 ng/mL. The RSD was 5.67% (for n = 7), the LOD was 0.352 ng/mL, and relative recoveries in vegetable samples ranged from 96.7 to 103.7%.

  2. On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ensafi, Ali A.; Shiraz, A. Zendegi

    2008-01-01

    Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL -1 Pb(II). The adsorption capacity of the solid phase was 0.20 mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method

  3. On-line separation and preconcentration of lead(II) by solid-phase extraction using activated carbon loaded with xylenol orange and its determination by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ensafi, Ali A. [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: Ensafi@cc.iut.ac.ir; Shiraz, A. Zendegi [College of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2008-02-11

    Activated carbon loaded with xylenol orange in a mini-column was used for the highly selective separation and preconcentration of Pb(II) ions. An on-line system for enrichment and the determination of Pb(II) was carried out on flame atomic absorption spectrometry. The conditions of preconcentration and quantitative recovery of Pb(II) from diluted solution, such as pH of aqueous phase, amount of the sorbent, volume of the solutions and flow variables were studied as well as effect of potential interfering ions. Under the optimum conditions, Pb(II) in an aqueous sample was concentrated about 200-fold and the detection limit was 0.4 ng mL{sup -1} Pb(II). The adsorption capacity of the solid phase was 0.20 mg of lead per one gram of the modified activated carbon. The modified activated carbon is stable for several treatments of sample solutions without the need for using any chemical reagent. The recovery of lead(II) from river water, waste water, tap water, and in the following reference materials: SRM 2711 Montana soil and GBW-07605 tea were obtained in the range of 97-104% by the proposed method.

  4. Use of Doehlert and constrained mixture designs in the development of a photo-oxidation procedure using UV radiation/H2O2 for decomposition of landfill leachate samples and determination of metals by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Marcos A. Bezerra

    2015-03-01

    Full Text Available This work proposes the use of photo-oxidation degradation with UV radiation/H2O2 as sample treatment for the determination of Fe, Zn, Mn, Ni and Co in municipal solid waste landfill leachate by flame atomic absorption spectrometry (FAAS. Three variables (pH, irradiation time and buffer concentration were optimized using Doehlert design and the proportions of mixture components submitted to UV radiation (leachate sample, buffer solution and H2O2 30%, v/v were optimized using a constrained mixture design. Using the experimental conditions established, this procedure allows limits of detection of 0.075, 0.025, 0.010, 0.075 and 0.041 µg mL-1, and the precision levels expressed as relative standard (%RSD, 0.5 µg mL-1 were 3.6, 1.8, 1.3, 3.3 and 1.7%, for Fe, Mn, Zn, Ni and Co respectively. Recovery tests were carried out for evaluation of the procedure accuracy and recoveries were between 92 and 106% for the studied metals. This procedure has been applied for the analysis of the landfill leachate collected in Jequié, a city of the southwestern region of the State of Bahia, Brazil. The results were compared with those obtained by acid digestion. There was no significant difference between the results obtained by the two methods based on paired t-test at 95% confidence level.

  5. Speciation of Tl(III and Tl(I in hair samples by dispersive liquid–liquid microextraction based on solidification of floating organic droplet prior to flame atomic absorption spectrometry determination

    Directory of Open Access Journals (Sweden)

    S.Z. Mohammadi

    2016-11-01

    Full Text Available Dispersive liquid–liquid microextraction based on solidification of floating organic droplet was successfully used as a sample preparation method prior to flame atomic absorption determination of trace amounts of Tl(III and Tl(I in hair samples. In the proposed method, 1-(2-pyridylazo-2-naphthol, 1-dodecanol and ethanol were used as chelating agent, extraction and dispersive solvent, respectively. Several factors that may be affected in the extraction process, such as type and volume of extraction and disperser solvents, pH, salting out effect, ionic strength and extraction time were studied. Under the optimal conditions, linearity was maintained between 6.0 and 900.0 ng mL−1 for Tl(III. The relative standard deviation for seven replicate determinations of 0.2 μg mL−1 Tl(III was 2.5%. The detection limit based on 3Sb for Tl(III in the original solution was 2.1 ng mL−1. The proposed method has been applied for the determination of trace amounts of thallium in hair samples and satisfactory results were obtained.

  6. Determination of lead at trace levels in mussel and sea water samples using vortex assisted dispersive liquid-liquid microextraction-slotted quartz tube-flame atomic absorption spectrometry.

    Science.gov (United States)

    Erarpat, Sezin; Özzeybek, Gözde; Chormey, Dotse Selali; Bakırdere, Sezgin

    2017-12-01

    In this study, dispersive liquid-liquid microextraction (DLLME) and slotted quartz tube (SQT) were coupled to flame atomic absorption spectrometry (FAAS) to increase the sensitivity of lead. Conditions such as the formation of the lead-dithizone complex, efficiency of the DLLME method and the output of the SQT were systematically optimized to improve the detection limit for the analyte. The conventional FAAS system was improved upon by about 3.0 times with SQT-FAAS, 32 times with DLLME-FAAS and 142 times with DLLME-SQT-FAAS. The method was applicable over a wide linear range (10-500 μg L -1 ). The limit of detection (LOD) determined by DLLME-SQT-FAAS for seawater and mussel were 2.7 μg L -1 and 270 μg kg -1 , respectively. The percent recoveries obtained for mussel and seawater samples (spiked at 20 and 50 μg L -1 ) were 95-96% and 98-110%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Solid Phase Extraction of Trace Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) Ions in Beverages on Functionalized Polymer Microspheres Prior to Flame Atomic Absorption Spectrometric Determinations.

    Science.gov (United States)

    Berber, Hale; Alpdogan, Güzin

    2017-01-01

    In this study, poly(glycidyl methacrylate-methyl methacrylate-divinylbenzene) was synthesized in the form of microspheres, and then functionalized by 2-aminobenzothiazole ligand. The sorption properties of these functionalized microspheres were investigated for separation, preconcentration and determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions using flame atomic absorption spectrometry. The optimum pH values for quantitative sorption were 2 - 4, 5 - 8, 6 - 8, 4 - 6, 2 - 6 and 2 - 3 for Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II), respectively, and also the highest sorption capacity of the functionalized microspheres was found to be for Cu(II) with the value of 1.87 mmol g -1 . The detection limits (3σ; N = 6) obtained for the studied metals in the optimal conditions were observed in the range of 0.26 - 2.20 μg L -1 . The proposed method was successfully applied to different beverage samples for the determination of Al(III), Fe(II), Co(II), Cu(II), Cd(II) and Pb(II) ions, with the relative standard deviation of <3.7%.

  8. Ligandless surfactant mediated solid phase extraction combined with Fe₃O₄ nano-particle for the preconcentration and determination of cadmium and lead in water and soil samples followed by flame atomic absorption spectrometry: multivariate strategy.

    Science.gov (United States)

    Jalbani, N; Soylak, M

    2014-04-01

    In the present study, a microextraction technique combining Fe3O4 nano-particle with surfactant mediated solid phase extraction ((SM-SPE)) was successfully developed for the preconcentration/separation of Cd(II) and Pb(II) in water and soil samples. The analytes were determined by flame atomic absorption spectrometry (FAAS). The effective variables such as the amount of adsorbent (NPs), the pH, concentration of non-ionic (TX-114) and centrifugation time (min) were investigated by Plackett-Burman (PBD) design. The important variables were further optimized by central composite design (CCD). Under the optimized conditions, the detection limits (LODs) of Cd(II) and Pb(II) were 0.15 and 0.74 µg/L, respectively. The validation of the proposed procedure was checked by the analysis of certified reference materials of TMDA 53.3 fortified water and GBW07425 soil. The method was successfully applied for the determination of Cd(II) and Pb(II) in water and soil samples. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Development of Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop for the Sensitive Determination of Trace Copper in Water and Beverage Samples by Flame Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Wu, Chunxia; Zhao, Bin; Li, Yingli; Wu, Qiuhua; Wang, Chun; Wang, Zhi

    2011-01-01

    A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent, respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to 300 ng mL -1 of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of 0.1 ng mL -1 . The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and 10.0 ng mL -1 were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%

  10. Solid-phase extraction of Mn(II), Co(II), Ni(II), Cu(II), Cd(II) and Pb(II) ions from environmental samples by flame atomic absorption spectrometry (FAAS)

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Celal [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Gundogdu, Ali [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Bulut, Volkan Numan [Department of Chemistry, Giresun Faculty of Art and Science, Karadeniz Technical University, 28049 Giresun (Turkey); Soylak, Mustafa [Department of Chemistry, Faculty of Art and Science, Erciyes University, 38039 Kayseri (Turkey)]. E-mail: soylak@erciyes.edu.tr; Elci, Latif [Department of Chemistry, Faculty of Art and Science, Pamukkale University, 20020 Denizli (Turkey); Sentuerk, Hasan Basri [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey); Tuefekci, Mehmet [Department of Chemistry, Faculty of Art and Science, Karadeniz Technical University, 61080 Trabzon (Turkey)

    2007-07-19

    A new method using a column packed with Amberlite XAD-2010 resin as a solid-phase extractant has been developed for the multi-element preconcentration of Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II) ions based on their complex formation with the sodium diethyldithiocarbamate (Na-DDTC) prior to flame atomic absorption spectrometric (FAAS) determinations. Metal complexes sorbed on the resin were eluted by 1 mol L{sup -1} HNO{sub 3} in acetone. Effects of the analytical conditions over the preconcentration yields of the metal ions, such as pH, quantity of Na-DDTC, eluent type, sample volume and flow rate, foreign ions etc. have been investigated. The limits of detection (LOD) of the analytes were found in the range 0.08-0.26 {mu}g L{sup -1}. The method was validated by analyzing three certified reference materials. The method has been applied for the determination of trace elements in some environmental samples.

  11. Flow injection analysis-flame atomic absorption spectrometry system for indirect determination of sulfite after on-line reduction of solid-phase manganese (IV) dioxide reactor.

    Science.gov (United States)

    Zare-Dorabei, Rouholah; Boroun, Shokoufeh; Noroozifar, Meissam

    2018-02-01

    A new and simple flow injection method followed by atomic absorption spectrometry was developed for indirect determination of sulfite. The proposed method is based on the oxidation of sulfite to sulphate ion using solid-phase manganese dioxide (30% W/W suspended on silica gel beads) reactor. MnO 2 will be reduced to Mn(II) by sample injection in to the column under acidic carrier stream of HNO 3 (pH 2) with flow rate of 3.5mLmin -1 at room temperature. Absorption measurement of Mn(II) which is proportional to the concentration of sulfite in the sample was carried out by atomic absorption spectrometry. The calibration curve was linear up to 25mgL -1 with a detection limit (DL) of 0.08mgL -1 for 400µL injection sample volume. The presented method is efficient toward sulfite determination in sugar and water samples with a relative standard deviation (RSD) less than 1.2% and a sampling rate of about 60h -1 . Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Bovine serum albumin-Cu(II) hybrid nanoflowers: An effective adsorbent for solid phase extraction and slurry sampling flame atomic absorption spectrometric analysis of cadmium and lead in water, hair, food and cigarette samples

    Energy Technology Data Exchange (ETDEWEB)

    Yilmaz, Erkan [Department of Chemistry, Faculty of Sciences, Erciyes University, Kayseri 38039 (Turkey); Ocsoy, Ismail [Department of Analytical Chemistry, Faculty of Pharmacy, Erciyes University, Kayseri 38039 (Turkey); Nanotechnology Research Center (ERNAM), Erciyes University, Kayseri 38039 (Turkey); Ozdemir, Nalan [Department of Chemistry, Faculty of Sciences, Erciyes University, Kayseri 38039 (Turkey); Soylak, Mustafa, E-mail: soylak@erciyes.edu.tr [Department of Chemistry, Faculty of Sciences, Erciyes University, Kayseri 38039 (Turkey)

    2016-02-04

    Herein, the synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers (BSA-NFs) through the building blocks of bovine serum albumin (BSA) and copper(II) ions in phosphate buffered saline (PBS) and their use as adsorbent for cadmium and lead ions are reported. The BSA-NFs, for the first time, were efficiently utilized as novel adsorbent for solid phase extraction (SPE) of cadmium and lead ions in water, food, cigarette and hair samples. The method is based on the separation and pre-concentration of Cd(II) and Pb(II) by BSA-NFs prior to determination by slurry analysis via flame atomic absorption spectrometry (FAAS). The analytes were adsorbed on BSA-NFs under the vortex mixing and then the ion-loaded slurry was separated and directly introduced into the flame AAS nebulizer by using a hand-made micro sample introduction system to eliminate a number of drawbacks. The effects of analytical key parameters, such as pH, amount of BSA-NFs, vortexing time, sample volume, and matrix effect of foreign ions on adsorbing of Cd(II) and Pb(II) were systematically investigated and optimized. The limits of detection (LODs) for Cd(II) and Pb(II) were calculated as 0.37 μg L{sup −1} and 8.8 μg L{sup −1}, respectively. The relative standard deviation percentages (RSDs) (N = 5) for Cd(II) and Pb(II) were 7.2%, and 5.0%, respectively. The accuracy of the developed procedure was validated by the analysis of certified reference materials (TMDA-53.3 Fortified Water, TMDA-70 Fortified Water, SPS-WW2 Waste Water, NCSDC-73349 Bush Branches and Leaves) and by addition/recovery analysis. The quantitative recoveries were obtained for the analysis of certified reference materials and addition/recovery tests. The method was successfully applied to the analysis of cadmium and lead in water, food, cigarette and hair samples. - Highlights: • The synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers is reported. • The nanoflowers were utilized for solid phase microextraction of

  13. Bovine serum albumin-Cu(II) hybrid nanoflowers: An effective adsorbent for solid phase extraction and slurry sampling flame atomic absorption spectrometric analysis of cadmium and lead in water, hair, food and cigarette samples.

    Science.gov (United States)

    Yilmaz, Erkan; Ocsoy, Ismail; Ozdemir, Nalan; Soylak, Mustafa

    2016-02-04

    Herein, the synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers (BSA-NFs) through the building blocks of bovine serum albumin (BSA) and copper(II) ions in phosphate buffered saline (PBS) and their use as adsorbent for cadmium and lead ions are reported. The BSA-NFs, for the first time, were efficiently utilized as novel adsorbent for solid phase extraction (SPE) of cadmium and lead ions in water, food, cigarette and hair samples. The method is based on the separation and pre-concentration of Cd(II) and Pb(II) by BSA-NFs prior to determination by slurry analysis via flame atomic absorption spectrometry (FAAS). The analytes were adsorbed on BSA-NFs under the vortex mixing and then the ion-loaded slurry was separated and directly introduced into the flame AAS nebulizer by using a hand-made micro sample introduction system to eliminate a number of drawbacks. The effects of analytical key parameters, such as pH, amount of BSA-NFs, vortexing time, sample volume, and matrix effect of foreign ions on adsorbing of Cd(II) and Pb(II) were systematically investigated and optimized. The limits of detection (LODs) for Cd(II) and Pb(II) were calculated as 0.37 μg L(-)(1) and 8.8 μg L(-)(1), respectively. The relative standard deviation percentages (RSDs) (N = 5) for Cd(II) and Pb(II) were 7.2%, and 5.0%, respectively. The accuracy of the developed procedure was validated by the analysis of certified reference materials (TMDA-53.3 Fortified Water, TMDA-70 Fortified Water, SPS-WW2 Waste Water, NCSDC-73349 Bush Branches and Leaves) and by addition/recovery analysis. The quantitative recoveries were obtained for the analysis of certified reference materials and addition/recovery tests. The method was successfully applied to the analysis of cadmium and lead in water, food, cigarette and hair samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Application of cloud point preconcentration and flame atomic absorption spectrometry for the determination of cadmium and zinc ions in urine, blood serum and water samples

    Directory of Open Access Journals (Sweden)

    Ardeshir Shokrollahi

    2013-01-01

    Full Text Available A simple, sensitive and selective cloud point extraction procedure is described for the preconcentration and atomic absorption spectrometric determination of Zn2+ and Cd2+ ions in water and biological samples, after complexation with 3,3',3",3'"-tetraindolyl (terephthaloyl dimethane (TTDM in basic medium, using Triton X-114 as nonionic surfactant. Detection limits of 3.0 and 2.0 µg L-1 and quantification limits 10.0 and 7.0 µg L-1were obtained for Zn2+ and Cd2+ ions, respectively. Relative standard deviation was 2.9 and 3.3, and enrichment factors 23.9 and 25.6, for Zn2+ and Cd2+ ions, respectively. The method enabled determination of low levels of Zn2+ and Cd2+ ions in urine, blood serum and water samples.

  15. Lifted Turbulent Jet Flames

    Science.gov (United States)

    1993-04-14

    flame length L simultaneously with h, and measuring the visible radiation I simultaneously with h. L(t) was found to be nearly uncorrelated with h(t...variation of 7i/2 /76 with ýh. These experiments included measuring the flame length L simultaneously with h, and measuring the visible radiation I...Measurements of Liftoff Height and Flame Length ... 66 4.5 Simultaneous Measurements of Liftoff Height and Radiation ....... 71 4.6 D scussion

  16. Validation of methods of atomic absorption with flame for the analysis of potasium, zinc and manganese, and a spectrophotometer for the analysis of phosphorus in samples of fertilizers

    International Nuclear Information System (INIS)

    Pineda Castro, L. E.

    1998-01-01

    This study validated the spectrophotometric method by atomic absorption for the analysis of potassium, manganese and zinc in samples of fertilizers. Likewise, it validated the spectrophotometric method for the analysis of phosphorus by generation of the fosfomolibdovanadate. species The limits of detection and quantification obtained to a level of confidence of the 95% were: 0,6 ppm and 1,1 ppm for the potassium, 1,1 ppm, and 2,2 ppm for the phosphorus, 0,3 ppm and 0,5 ppm for the zinc and 0,6 ppm and 1,1 ppm for the manganese respectively. It established the repetibility and reproducible of the method to a level of the 95% of confidence and it determined that the fertilizers tolerance norm is complied with adequately for the potassium and the manganese. On the other hand, for the concentrations of phosphorus higher than 20%, it presented smaller reproducibility. For the zinc, it presented problems of precision of the method, in the two samples analyzed. The accuracy of the methodologies were the adequate. In the case of the phosphorus, it recommended the employment of a composed digestive mixture of nitric and perchloric acid when be a matter of materials that possess organic matter. (S. Grainger) [es

  17. Investigation of artifacts caused by deuterium background correction in the determination of phosphorus by electrothermal atomization using high-resolution continuum source atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Dessuy, Morgana B.; Vale, Maria Goreti R.; Lepri, Fabio G.; Borges, Daniel L.G.; Welz, Bernhard; Silva, Marcia M.; Heitmann, Uwe

    2008-01-01

    The artifacts created in the measurement of phosphorus at the 213.6-nm non-resonance line by electrothermal atomic absorption spectrometry using line source atomic absorption spectrometry (LS AAS) and deuterium lamp background correction (D 2 BC) have been investigated using high-resolution continuum source atomic absorption spectrometry (HR-CS AAS). The absorbance signals and the analytical curves obtained by LS AAS without and with D 2 BC, and with HR-CS AAS without and with automatic correction for continuous background absorption, and also with least-squares background correction for molecular absorption with rotational fine structure were compared. The molecular absorption due to the suboxide PO that exhibits pronounced fine structure could not be corrected by the D 2 BC system, causing significant overcorrection. Among the investigated chemical modifiers, NaF, La, Pd and Pd + Ca, the Pd modifier resulted in the best agreement of the results obtained with LS AAS and HR-CS AAS. However, a 15% to 100% higher sensitivity, expressed as slope of the analytical curve, was obtained for LS AAS compared to HR-CS AAS, depending on the modifier. Although no final proof could be found, the most likely explanation is that this artifact is caused by a yet unidentified phosphorus species that causes a spectrally continuous absorption, which is corrected without problems by HR-CS AAS, but which is not recognized and corrected by the D 2 BC system of LS AAS

  18. Autoignited lifted flames of dimethyl ether in heated coflow air

    KAUST Repository

    Al-Noman, Saeed M.

    2018-05-16

    Autoignited lifted flames of dimethyl ether (DME) in laminar nonpremixed jets with high-temperature coflow air have been studied experimentally. When the initial temperature was elevated to over 860 K, an autoignition occurred without requiring an external ignition source. A planar laser-induced fluorescence (PLIF) technique for formaldehyde (CH2O) visualized qualitatively the zone of low temperature kinetics in a premixed flame. Two flame configurations were investigated; (1) autoignited lifted flames with tribrachial edge having three distinct branches of a lean and a rich premixed flame wings with a trailing diffusion flame and (2) autoignited lifted flames with mild combustion when the fuel was highly diluted. For the autoignited tribrachial edge flames at critical autoignition conditions, exhibiting repetitive extinction and re-ignition phenomena near a blowout condition, the characteristic flow time (liftoff height scaled with jet velocity) was correlated with the square of the ignition delay time of the stoichiometric mixture. The liftoff heights were also correlated as a function of jet velocity times the square of ignition delay time. Formaldehydes were observed between the fuel nozzle and the lifted flame edge, emphasizing a low-temperature kinetics for autoignited lifted flames, while for a non-autoignited lifted flame, formaldehydes were observed near a thin luminous flame zone.For the autoignited lifted flames with mild combustion, especially at a high temperature, a unique non-monotonic liftoff height behavior was observed; decreasing and then increasing liftoff height with jet velocity. This behavior was similar to the binary mixture fuels of CH4/H2 and CO/H2 observed previously. A transient homogeneous autoignition analysis suggested that such decreasing behavior with jet velocity can be attributed to partial oxidation characteristics of DME in producing appreciable amounts of CH4/CO/H2 ahead of the edge flame region.

  19. Autoignited lifted flames of dimethyl ether in heated coflow air

    KAUST Repository

    Al-Noman, Saeed M.; Choi, Byung Chul; Chung, Suk-Ho

    2018-01-01

    Autoignited lifted flames of dimethyl ether (DME) in laminar nonpremixed jets with high-temperature coflow air have been studied experimentally. When the initial temperature was elevated to over 860 K, an autoignition occurred without requiring an external ignition source. A planar laser-induced fluorescence (PLIF) technique for formaldehyde (CH2O) visualized qualitatively the zone of low temperature kinetics in a premixed flame. Two flame configurations were investigated; (1) autoignited lifted flames with tribrachial edge having three distinct branches of a lean and a rich premixed flame wings with a trailing diffusion flame and (2) autoignited lifted flames with mild combustion when the fuel was highly diluted. For the autoignited tribrachial edge flames at critical autoignition conditions, exhibiting repetitive extinction and re-ignition phenomena near a blowout condition, the characteristic flow time (liftoff height scaled with jet velocity) was correlated with the square of the ignition delay time of the stoichiometric mixture. The liftoff heights were also correlated as a function of jet velocity times the square of ignition delay time. Formaldehydes were observed between the fuel nozzle and the lifted flame edge, emphasizing a low-temperature kinetics for autoignited lifted flames, while for a non-autoignited lifted flame, formaldehydes were observed near a thin luminous flame zone.For the autoignited lifted flames with mild combustion, especially at a high temperature, a unique non-monotonic liftoff height behavior was observed; decreasing and then increasing liftoff height with jet velocity. This behavior was similar to the binary mixture fuels of CH4/H2 and CO/H2 observed previously. A transient homogeneous autoignition analysis suggested that such decreasing behavior with jet velocity can be attributed to partial oxidation characteristics of DME in producing appreciable amounts of CH4/CO/H2 ahead of the edge flame region.

  20. The Advanced Light Source at Lawrence Berkeley Laboratory: a new tool for research in atomic physics

    International Nuclear Information System (INIS)

    Schlachter, A.S.; Robinson, A.L.

    1991-01-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Based on a low-emittance electron storage ring optimized to operate at 1.5 GeV, the ALS will have 10 long straight sections available for insertion devices (undulators and wigglers) and 24 high-quality bend-magnet ports. The short pulse width (30-50 ps) will be ideal for time-resolved measurements. Undulators will generate high-brightness partially coherent soft X-ray and ultraviolet (XUV) radiation from below 10 eV to above 2 keV; this radiation is plane polarized. Wigglers and bend magnets will extend the spectrum by generating high fluxes of X-rays to photon energies above 10 keV. The ALS will have an extensive research program in which XUV radiation is used to study matter in allk its varied gaseous, liquid, and solid forms. The high brightness will open new areas of research in the materials sciences, such as spatially resolved spectroscopy (spectromicroscopy), and in biology, such as X-ray microscopy with element-specific sensitivity; the high flux will allow measurements in atomic physics and chemistry to be made with tenuous gas-phase targets. Technological applications could include lithography and nano-fabrication. (orig.)

  1. Spatial distribution and implications to sources of halogenated flame retardants in riverine sediments of Taizhou, an intense e-waste recycling area in eastern China.

    Science.gov (United States)

    Zhou, Shanshan; Fu, Jie; He, Huan; Fu, Jianjie; Tang, Qiaozhi; Dong, Minfeng; Pan, Yongqiang; Li, An; Liu, Weiping; Zhang, Limin

    2017-10-01

    Concentrations and spatial distribution pattern of organohalogen flame retardants were investigated in the riverine surface sediments from Taizhou, an intensive e-waste recycling region in China. The analytes were syn- and anti- Dechlorane Plus (DP), Dechloranes 602, 603, and 604, a DP monoadduct, two dechlorinated DPs and 8 congeners of polybrominated diphenyl ethers (PBDEs). The concentrations of Σ 8 PBDEs, ΣDP, ΣDec600s, and ΣDP-degradates ranged from recycling facilities. Such patterns were largely shared by Dec602 and dechlorinated DP, although their concentration levels were much lower. These major flame retardants significantly correlate with each other, and cluster together in the loading plot of principle component analysis. In contrast, most non-deca PBDE congeners do not correlate with DPs. Dec604 stood out having distinctly different spatial distribution pattern, which could be linked to historical use of mirex. Organic matter content of the sediment was not the dominant factor in determining the spatial pattern of pollution by halogenated flame retardants in the rivers of this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. On the possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry for the simultaneous or sequential monitoring of multiple atomic lines

    International Nuclear Information System (INIS)

    Resano, M.; Rello, L.; Florez, M.; Belarra, M.A.

    2011-01-01

    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.

  3. A novel task specific magnetic polymeric ionic liquid for selective preconcentration of potassium in oil samples using centrifuge-less dispersive liquid-liquid microextraction technique and its determination by flame atomic emission spectroscopy.

    Science.gov (United States)

    Beiraghi, Asadollah; Shokri, Masood

    2018-02-01

    In the present study a new centrifuge-less dispersive liquid-liquid microextraction technique based on application of a new task specific magnetic polymeric ionic liquid (TSMPIL) as a chelating and extraction solvent for selective preconcentration of trace amounts of potassium from oil samples is developed, for the first time. After extraction, the fine droplets of TSMPIL were transferred into an eppendorf tube and diluted to 500µL using distilled water. Then, the enriched analyte was determined by flame atomic emission spectroscopy (FAES). Several important factors affecting both the complexation and extraction efficiency including extraction time, rate of vortex agitator, amount of carbonyl iron powder, pH of sample solution, volume of ionic liquid as well as effects of interfering species were investigated and optimized. Under the optimal conditions, the limits of detection (LOD) and quantification (LOQ) were 0.5 and 1.6µgL -1 respectively with the preconcentration factor of 128. The precision (RSD %) for seven replicate determinations at 10µgL -1 of potassium was better than 3.9%. The relative recoveries for the spiked samples were in the acceptable range of 95-104%. The results demonstrated that no remarkable interferences are created by other various ions in the determination of potassium, so that the tolerance limits (W Ion /W K ) of major cations and anions were in the range of 2500-10,000. The purposed method was successfully applied for the analysis of potassium in some oil samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A photo-oxidation procedure using UV radiation/H{sub 2}O{sub 2} for decomposition of wine samples - Determination of iron and manganese content by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Walter N.L. dos [Departamento de Ciencias Exatas e da Terra, Universidade do Estado da Bahia, Salvador, Bahia (Brazil); Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)], E-mail: wlopes@uneb.br; Brandao, Geovani C.; Portugal, Lindomar A.; David, Jorge M.; Ferreira, Sergio L.C. [Universidade Federal da Bahia, Instituto de Quimica, Campus Ondina, Salvador, Bahia, 40170-290 Brazil (Brazil)

    2009-06-15

    This paper proposes the use of photo-oxidation with UV radiation/H{sub 2}O{sub 2} as sample pretreatment for the determination of iron and manganese in wines by flame atomic absorption spectrometry (FAAS). The optimization involved the study of the following variables: pH and concentration of buffer solution, concentrated hydrogen peroxide volume and irradiation time. The evaluation of sample degradation was monitored by measuring the absorbance at the maximum wavelength of red wine (530 nm). Using the experimental conditions established during the optimization (irradiation time of 30 min, oxidant volume of 2.5 mL, pH 10, and a buffer concentration of 0.15 mol L{sup - 1}), this procedure allows the determination of iron and manganese with limits of detection of 30 and 22 {mu}g L{sup - 1}, respectively, for a 5 mL volume of digested sample. The precision levels, expressed as relative standard deviation (RSD), were 2.8% and 0.65% for iron and 2.7% and 0.54% for manganese for concentrations of 0.5 and 2.0 mg L{sup - 1}, respectively. Addition/recovery tests for evaluation of the accuracy were in the ranges of 90%-111% and 95%-107% for iron and manganese, respectively. This digestion procedure has been applied for the determination of iron and manganese in six wine samples. The concentrations varied from 1.58 to 2.77 mg L{sup - 1} for iron and from 1.30 to 1.91 mg L{sup - 1} for manganese. The results were compared with those obtained by an acid digestion procedure and determination of the elements by FAAS. There was no significant difference between the results obtained by the two methods based on a paired t-test (at 95% confidence level)

  5. Solid-Phase Extraction with Diethyldithiocarbamate as Chelating Agent for Preconcentration and Trace Determination of Copper, Iron and Lead in Fruit Wine and Distilled Spirit by Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Saksit Chanthal

    2011-01-01

    Full Text Available Some heavy metals that present in wine and distilled spirit as background contamination are generally found at trace level particularly less than detection limit of common analytical techniques including flame atomic absorption spectrometry (FAAS. Thus, preconcentration method of the trace metals was developed. The optimum conditions for diethyldithiocarbamate (DDTC complexes of Cu, Fe and Pb were then investigated for the preconcentration step using C18 solid-phase extraction prior to measurement by FAAS. The preconcentration factor of 15-fold was obtained with the appropriate ratio of sample volume used (150 mL to 10 mL final volume giving their method recoveries of Cu, Fe and Pb found in the ranges of 96.5-107, 102-116 and 91.7-107%, respectively. Precision determinations (n = 10 for 0.1 mg L-1 of Cu, Fe and Pb each in a model solution were 3.7, 4.2 and 7.1 %RSD respectively. The detection limits (3SD of Cu, Fe and Pb were found to be 1.4, 3.3 and 5.7 μg L-1, respectively. The developed method was applied to ten samples of local fruit wines and five samples of distilled spirits, resulting in the ranges of 0.012-0.80 and 0.12-8.8 mg L-1 for Cu; 0.18-3.4 and 0.036-0.29 mg L-1 for Fe and 0.0070-0.053 and 0.014-0.026 mg L-1 for Pb, respectively. Therefore, the method is simple and inexpensive for routine analysis of the trace metals in these samples to overcome limit of detection of the instrument used.

  6. Application of Box-Behnken design in the optimisation of an on-line pre-concentration system using knotted reactor for cadmium determination by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Souza, Anderson S.; Santos, Walter N.L. dos; Ferreira, Sergio L.C.

    2005-01-01

    The present paper proposes an on-line pre-concentration system for cadmium determination in drinking water using flame atomic absorption spectrometry (FAAS). Cadmium(II) ions are retained as 1-(2-pyridylazo)-2-naphthol (PAN) complex at the walls of a knotted reactor, followed of elution using hydrochloric acid solution. The optimization was performed in two steps using factorial design for preliminary evaluation and a Box-Behnken design for determination of the critical experimental conditions. The variables involved were: sampling flow-rate, reagent concentration, pH and buffer concentration, and as response the analytical signal (absorbance). The validation process was performed considering the parameters: linearity and other characteristics of the calibration curve, analytical features of on-line pre-concentration system, precision, effect of other ions in the pre-concentration system and accuracy. Using the optimized experimental conditions, the procedure allows cadmium determination with a detection limit (3 σ / S) of 0.10 μg L -1 , a quantification limit (10 σ / S) of 0.33 μg L -1 , and a precision, calculated as relative standard deviation (RSD) of 2.7% (n = 7) and 2.4% (n = 7) for cadmium concentrations of 5 and 25 μg L -1 , respectively. A pre-concentration factor of 18 and a sampling frequency of 48 h -1 were obtained. The recovery for cadmium in the presence of several ions demonstrated that this procedure could be applied for the analysis of water samples. The method was applied for cadmium determination in drinking water samples collected in Salvador City, Brazil. The cadmium concentrations found in five samples were lower than the maximum permissible levels established by the World Health Organization

  7. An atomic beam source for fast loading of a magneto-optical trap under high vacuum

    DEFF Research Database (Denmark)

    McDowall, P.D.; Hilliard, Andrew; Grünzweig, T.

    2012-01-01

    We report on a directional atomic beam created using an alkali metal dispenser and a nozzle. By applying a high current (15 A) pulse to the dispenser at room temperature we can rapidly heat it to a temperature at which it starts dispensing, avoiding the need for preheating. The atomic beam produced...... is capable of loading 90 of a magneto-optical trap (MOT) in less than 7 s while maintaining a low vacuum pressure of 10 -11 Torr. The transverse velocity components of the atomic beam are measured to be within typical capture velocities of a rubidium MOT. Finally, we show that the atomic beam can be turned...

  8. Turbulence-flame interactions in DNS of a laboratory high Karlovitz premixed turbulent jet flame

    Science.gov (United States)

    Wang, Haiou; Hawkes, Evatt R.; Chen, Jacqueline H.

    2016-09-01

    In the present work, direct numerical simulation (DNS) of a laboratory premixed turbulent jet flame was performed to study turbulence-flame interactions. The turbulent flame features moderate Reynolds number and high Karlovitz number (Ka). The orientations of the flame normal vector n, the vorticity vector ω and the principal strain rate eigenvectors ei are examined. The in-plane and out-of-plane angles are introduced to quantify the vector orientations, which also measure the flame geometry and the vortical structures. A general observation is that the distributions of these angles are more isotropic downstream as the flame and the flow become more developed. The out-of-plane angle of the flame normal vector, β, is a key parameter in developing the correction of 2D measurements to estimate the corresponding 3D quantities. The DNS results show that the correction factor is unity at the inlet and approaches its theoretical value of an isotropic distribution downstream. The alignment characteristics of n, ω and ei, which reflect the interactions of turbulence and flame, are also studied. Similar to a passive scalar gradient in non-reacting flows, the flame normal has a tendency to align with the most compressive strain rate, e3, in the flame, indicating that turbulence contributes to the production of scalar gradient. The vorticity dynamics are examined via the vortex stretching term, which was found to be the predominant source of vorticity generation balanced by dissipation, in the enstrophy transport equation. It is found that although the vorticity preferentially aligns with the intermediate strain rate, e2, the contribution of the most extensive strain rate, e1, to vortex stretching is comparable with that of the intermediate strain rate, e2. This is because the eigenvalue of the most extensive strain rate, λ1, is always large and positive. It is confirmed that the vorticity vector is preferentially positioned along the flame tangential plane, contributing

  9. Atomic physics with hard X-rays from high brilliance synchrotron light sources

    International Nuclear Information System (INIS)

    Southworth, S.; Gemmell, D.

    1996-08-01

    A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms

  10. Atomic physics with hard X-rays from high brilliance synchrotron light sources

    Energy Technology Data Exchange (ETDEWEB)

    Southworth, S.; Gemmell, D.

    1996-08-01

    A century after the discovery of x rays, the experimental capability for studying atomic structure and dynamics with hard, bright synchrotron radiation is increasing remarkably. Tempting opportunities arise for experiments on many-body effects, aspects of fundamental photon-atom interaction processes, and relativistic and quantum-electrodynamic phenomena. Some of these possibilities are surveyed in general terms.

  11. Formation of atomic clusters through the laser ablation of refractory materials in a supersonic molecular beam source

    International Nuclear Information System (INIS)

    Haufler, R.E.; Puretzky, A.A.; Compton, R.N.

    1993-01-01

    Concepts which guide the design of atomic cluster supersonic beam sources have been developed. These ideas are founded on the knowledge of laser ablation dynamics and are structured in order to take advantage of certain features of the ablation event. Some of the drawbacks of previous cluster source designs become apparent when the sequence of events following laser ablation are clarified. Key features of the new cluster source design include control of the cluster size distribution, uniform performance with a variety of solid materials and elements, high beam intensity, and significant removal of internal energy during the supersonic expansion

  12. Unsteady Flame Embedding

    KAUST Repository

    El-Asrag, Hossam A.

    2011-01-01

    Direct simulation of all the length and time scales relevant to practical combustion processes is computationally prohibitive. When combustion processes are driven by reaction and transport phenomena occurring at the unresolved scales of a numerical simulation, one must introduce a dynamic subgrid model that accounts for the multiscale nature of the problem using information available on a resolvable grid. Here, we discuss a model that captures unsteady flow-flame interactions- including extinction, re-ignition, and history effects-via embedded simulations at the subgrid level. The model efficiently accounts for subgrid flame structure and incorporates detailed chemistry and transport, allowing more accurate prediction of the stretch effect and the heat release. In this chapter we first review the work done in the past thirty years to develop the flame embedding concept. Next we present a formulation for the same concept that is compatible with Large Eddy Simulation in the flamelet regimes. The unsteady flame embedding approach (UFE) treats the flame as an ensemble of locally one-dimensional flames, similar to the flamelet approach. However, a set of elemental one-dimensional flames is used to describe the turbulent flame structure directly at the subgrid level. The calculations employ a one-dimensional unsteady flame model that incorporates unsteady strain rate, curvature, and mixture boundary conditions imposed by the resolved scales. The model is used for closure of the subgrid terms in the context of large eddy simulation. Direct numerical simulation (DNS) data from a flame-vortex interaction problem is used for comparison. © Springer Science+Business Media B.V. 2011.

  13. The design and characteristics of direct current glow discharge atomic emission source operated with plain and hollow cathodes

    International Nuclear Information System (INIS)

    Qayyum, A.; Mahmood, M.I.

    2008-01-01

    A compact direct current glow discharge atomic emission source has been designed and constructed for analytical applications. This atomic emission source works very efficiently at a low-input electrical power. The design has some features that make it distinct from that of the conventional Grimm glow discharge source. The peculiar cathode design offered greater flexibility on size and shape of the sample. As a result the source can be easily adopted to operate in Plain or Hollow Cathode configuration. I-V and spectroscopic characteristics of the source were compared while operating it with plain and hollow copper cathodes. It was observed that with hollow cathode, the source can be operated at a less input power and generates greater Cu I and Cu II line intensities. Also, the intensity of Cu II line rise faster than Cu I line with argon pressure for both cathodes. But the influence of pressure on Cu II lines was more significant when the source is operated with hollow cathode

  14. New source of MeV negative ion and neutral atom beams

    Energy Technology Data Exchange (ETDEWEB)

    Ter-Avetisyan, S., E-mail: sargis@gist.ac.kr [Center for Relativistic Laser Science, Institute for Basic Science (IBS), Gwangju 500-712 (Korea, Republic of); Department of Physics and Photon Science, GIST, Gwangju 500-712 (Korea, Republic of); Braenzel, J.; Schnürer, M. [Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Berlin 12489 (Germany); Prasad, R. [Institute for Laser and Plasma Physics, Heinrich Heine University, Duesseldorf 40225 (Germany); Borghesi, M. [School of Mathematics and Physics, The Queen’s University of Belfast, Belfast BT7-1NN (United Kingdom); Jequier, S.; Tikhonchuk, V. [Centre Lasers Intenses et Applications, CEA, CNRS, University of Bordeaux, 33405 Talence (France)

    2016-02-15

    The scenario of “electron-capture and -loss” was recently proposed for the formation of negative ion and neutral atom beams with MeV kinetic energies. However, it does not explain why the formation of negative ions in a liquid spray is much more efficient than with an isolated atom. The role of atomic excited states in the charge-exchange processes is considered, and it is shown that it cannot account for the observed phenomena. The processes are more complex than the single electron-capture and -loss approach. It is suggested that the shell effects in the electronic structure of the projectile ion and/or target atoms may influence the capture/loss probabilities.

  15. New source of MeV negative ion and neutral atom beams

    International Nuclear Information System (INIS)

    Ter-Avetisyan, S.; Braenzel, J.; Schnürer, M.; Prasad, R.; Borghesi, M.; Jequier, S.; Tikhonchuk, V.

    2016-01-01

    The scenario of “electron-capture and -loss” was recently proposed for the formation of negative ion and neutral atom beams with MeV kinetic energies. However, it does not explain why the formation of negative ions in a liquid spray is much more efficient than with an isolated atom. The role of atomic excited states in the charge-exchange processes is considered, and it is shown that it cannot account for the observed phenomena. The processes are more complex than the single electron-capture and -loss approach. It is suggested that the shell effects in the electronic structure of the projectile ion and/or target atoms may influence the capture/loss probabilities

  16. Hydrogen-enriched non-premixed jet flames : analysis of the flame surface, flame normal, flame index and Wobbe index

    NARCIS (Netherlands)

    Ranga Dinesh, K.K.J.; Jiang, X.; Oijen, van J.A.

    2014-01-01

    A non-premixed impinging jet flame is studied using three-dimensional direct numerical simulation with detailed chemical kinetics in order to investigate the influence of fuel variability on flame surface, flame normal, flame index and Wobbe index for hydrogen-enriched combustion. Analyses indicate

  17. Flame structure of methane inverse diffusion flame

    KAUST Repository

    Elbaz, Ayman M.; Roberts, William L.

    2014-01-01

    This paper presents high speed images of OH-PLIF at 10. kHz simultaneously with 2D PIV (particle image velocimetry) measurements collected along the entire length of an inverse diffusion flame with circumferentially arranged methane fuel jets. For a

  18. Human exposure to brominated flame retardants through dust in different indoor environments: Identifying the sources of concentration differences in hair from men and women.

    Science.gov (United States)

    Li, Junqi; Dong, Zheng; Wang, Ying; Bao, Junsong; Yan, Yijun; Liu, Anming; Jin, Jun

    2018-08-01

    Brominated flame retardants (BFRs) can accumulate in humans and are associated with adverse health effects. The study was conducted to determine the differences in Polybrominated diphenyl ethers (PBDEs) and alternative brominated flame retardant (Alt-BFR) concentrations between men and women. We analyzed hair samples from 14 male and 20 female university students, paired dust samples from their dormitories (10 for males and 8 for females), and six dust samples from university teaching buildings. The total PBDE concentrations in hair from females were significantly (three times) higher (p = 0.012) than that from males (means 372 and 109 ng/g, respectively). The mean total PBDE concentrations in classroom and dormitory dust were 36100 and 2012 ng/g, respectively. The PBDE patterns were different in the male and female hair samples, as were the patterns in the classroom and dormitory dust. There are no reports concerning human exposure to BFRs through dust that was assessed considering academic and residential environments simultaneously. The differences between BFR exposure for males and females and the differences between BFR concentrations in hair samples from males and females were consistent for 71.4% of the compounds. However, using only dormitory dust in the calculations gave consistent differences only for 28.6% of the compounds, suggesting that the BFR concentration differences in hair were mainly because females spent much more time than males in classrooms. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. ARC: An open-source library for calculating properties of alkali Rydberg atoms

    Science.gov (United States)

    Šibalić, N.; Pritchard, J. D.; Adams, C. S.; Weatherill, K. J.

    2017-11-01

    We present an object-oriented Python library for the computation of properties of highly-excited Rydberg states of alkali atoms. These include single-body effects such as dipole matrix elements, excited-state lifetimes (radiative and black-body limited) and Stark maps of atoms in external electric fields, as well as two-atom interaction potentials accounting for dipole and quadrupole coupling effects valid at both long and short range for arbitrary placement of the atomic dipoles. The package is cross-referenced to precise measurements of atomic energy levels and features extensive documentation to facilitate rapid upgrade or expansion by users. This library has direct application in the field of quantum information and quantum optics which exploit the strong Rydberg dipolar interactions for two-qubit gates, robust atom-light interfaces and simulating quantum many-body physics, as well as the field of metrology using Rydberg atoms as precise microwave electrometers. Program Files doi:http://dx.doi.org/10.17632/hm5n8w628c.1 Licensing provisions: BSD-3-Clause Programming language: Python 2.7 or 3.5, with C extension External Routines: NumPy [1], SciPy [1], Matplotlib [2] Nature of problem: Calculating atomic properties of alkali atoms including lifetimes, energies, Stark shifts and dipole-dipole interaction strengths using matrix elements evaluated from radial wavefunctions. Solution method: Numerical integration of radial Schrödinger equation to obtain atomic wavefunctions, which are then used to evaluate dipole matrix elements. Properties are calculated using second order perturbation theory or exact diagonalisation of the interaction Hamiltonian, yielding results valid even at large external fields or small interatomic separation. Restrictions: External electric field fixed to be parallel to quantisation axis. Supplementary material: Detailed documentation (.html), and Jupyter notebook with examples and benchmarking runs (.html and .ipynb). [1] T.E. Oliphant

  20. optimization of flame atomic absorption spectrometry

    African Journals Online (AJOL)

    unesco

    very narrow; and levels as low as 0.01 mg/L can cause deformation and death of wildfowl. ... widely used for analysis of As, Se and other metals in different types of ... (17) optimised the PerkinElmer (Norwalk, Connecticut, USA) model A300.

  1. Combination of flame atomic absorption spectrometry with ...

    African Journals Online (AJOL)

    ... standard deviation of the blank (3Sb) was 0.5 ng mL−1 in original solution. The relative standard deviation for eight replicate determinations of 1.0 mg mL-1 lead ... of Standard and Technology, Trace elements in water (NIST CRM 1643e).

  2. Versatile user-oriented atomic and molecular beam apparatus for use with the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Mitchell, J.B.A.; Grover, J.R.

    1978-11-01

    A proposed atomic and moleuclar beam apparatus is described for photon interaction studies using the National Sychrotron Light Source at the Brookhaven National Laboratory. This apparatus will employ ultrahigh vacuum techniques compatible with storage ring operation. Supersonic nozzle sources will be used to produce the beams and signal detection will be accomplished using a quadrupole mass analysis system. The equipment is intended for use both by in-house and outside users and primary consideration has been given to flexibility of design. The application of photoionization techniques to the study of crossed beam reactive scattering with particular emphasis on internal energy distribution analysis is discussed

  3. The structure of horizontal hydrogen-steam diffusion flames

    International Nuclear Information System (INIS)

    Chan, C.K.; Guerrero, A.

    1997-01-01

    This paper summarizes a systematic study on the stability, peak temperature and flame length of various horizontal hydrogen-steam diffusion flames in air. Results from this study are discussed in terms of their impact on hydrogen management in a nuclear containment building after a nuclear reactor accident. They show that, for a certain range of emerging hydrogen-steam compositions, a stable diffusion flame can anchor itself at the break in the primary heat transport system. The length of this flame can be up to 100 times the break diameter. This implies that creation of a stable diffusion flame at the break is a possible outcome of the deliberate ignition mitigation scheme. The high temperature and heat flux from a diffusion flame can threaten nearby equipment. However, due to the presence of steam and turbulent mixing with surrounding air, the peak temperatures of these diffusion flames are much lower than the adiabatic constant pressure combustion temperature of a stoichiometric hydrogen-air mixture. These results suggest that the threat of a diffusion flame anchored at the break may be less severe than conservative analysis would indicate. Furthermore, such a flame can remove hydrogen at the source and minimize the possibility of a global gas explosion. (author)

  4. 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

    Science.gov (United States)

    Ombaba, Jackson M.

    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 device exhibits a stable signal because the plasma is self-seeding and reignites itself every half cycle. A tesla coil is not required to commence generation of the plasma if the ac voltage applied is greater than the breakdown voltage of the plasma-supporting gas. 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 (Mvutilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienyl manganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer (common room humidifier) 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 also considered. Figures of merits of selected elements both in absorption and emission modes are reported. The evaluation of a computer-aided optimization program, Drylab GC, using

  5. Production of rare-earth atomic negative ion beams in a cesium-sputter-type negative ion source

    International Nuclear Information System (INIS)

    Davis, V.T.; Covington, A.M.; Duvvuri, S.S.; Kraus, R.G.; Emmons, E.D.; Kvale, T.J.; Thompson, J.S.

    2007-01-01

    The desire to study negative ion structure and negative ion-photon interactions has spurred the development of ion sources for use in research and industry. The many different types of negative ion sources available today differ in their characteristics and abilities to produce anions of various species. Thus the importance of choosing the correct type of negative ion source for a particular research or industrial application is clear. In this study, the results of an investigation on the production of beams composed of negatively-charged rare-earth ions from a cylindrical-cathode-geometry, cesium-sputter-type negative ion source are presented. Beams of atomic anions have been observed for most of the first-row rare-earth elements, with typical currents ranging from hundreds of picoamps to several nanoamps

  6. Unsteady Flame Embedding

    KAUST Repository

    El-Asrag, Hossam A.; Ghoniem, Ahmed F.

    2011-01-01

    simulation, one must introduce a dynamic subgrid model that accounts for the multiscale nature of the problem using information available on a resolvable grid. Here, we discuss a model that captures unsteady flow-flame interactions- including extinction, re

  7. Setup and proof of principle of SAPIS (Stored Atoms Polarized Ion Source), a novel source of polarized H-/D- ions

    International Nuclear Information System (INIS)

    Emmerich, R.

    2007-01-01

    The objective of this work was the setup and the proof-of-principle of a new type of negative polarized hydrogen or deuterium ion source, which is based on the charge-exchange reaction vectorH 0 +Cs 0 →vectorH - +Cs + , as for instance the Colliding-Beams-Source (CBS) at the Cooler Synchrotron COSY in Juelich. In contrast to the CBS, the use of a storage cell for the charge-exchange region promises an increase in H - current by at least an order of magnitude without considerable polarization losses. For these purposes, a new laboratory was equipped and both a polarized hydrogen/deuterium atomic beam source and an intense neutral cesium-beam source have been build-on. A Lambshift polarimeter, which allows the measurement of the nuclear polarization of the atomic as well as ionic beams, was completed with the construction of a new spin-filter. After commissioning and optimizing each of these sources, a storage cell was developed and installed in the charge-exchange region with a magnetic field. Additionally, components for the extraction, detection and analysis of the negative ion beam were installed. Following the decisive proof of principle, investigation of the properties of the storage cell, especially as to H recombination and depolarisation, was begun. Furthermore, a number of software programs was developed for the control and monitoring of different components of the sources as well as a universal measuring software for the complete installation, including the measurement and calculation of the beam polarization. At the same time, the remote control system of the Cologne source of polarized ions LASCO at the FN tandem accelerator was completely modernized. (orig.)

  8. Flame synthesis of zinc oxide nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Merchan-Merchan, Wilson, E-mail: wmerchan-merchan@ou.edu [School of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019 (United States); Farahani, Moien Farmahini [School of Aerospace and Mechanical Engineering, University of Oklahoma, Norman, OK 73019 (United States)

    2013-02-01

    Highlights: Black-Right-Pointing-Pointer We report a single-step flame method for the synthesis of Zn oxide nanocrystals. Black-Right-Pointing-Pointer Diverse flame positions lead to a variation of Zn oxide nanocrystal growth. Black-Right-Pointing-Pointer The synthesized crystals have polyhedral, pipet- and needle-like shape. Black-Right-Pointing-Pointer High length-to-diameter aspect-ratio crystals appear in a higher temperature flame. Black-Right-Pointing-Pointer The crystal growth mechanism corresponds to vapor-to-solid conversion. - Abstract: Distinctive zinc oxide (ZnO) nanocrystals were synthesized on the surface of Zn probes using a counter-flow flame medium formed by methane/acetylene and oxygen-enriched air streams. The source material, a zinc wire with a purity of {approx}99.99% and diameter of 1 mm, was introduced through a sleeve into the oxygen rich region of the flame. The position of the probe/sleeve was varied within the flame medium resulting in growth variation of ZnO nanocrystals on the surface of the probe. The shape and structural parameters of the grown crystals strongly depend on the flame position. Structural variations of the synthesized crystals include single-crystalline ZnO nanorods and microprisms (ZMPs) (the ZMPs have less than a few micrometers in length and several hundred nanometers in cross section) with a large number of facets and complex axial symmetry with a nanorod protruding from their tips. The protruding rods are less than 100 nm in diameter and lengths are less than 1 {mu}m. The protruding nanorods can be elongated several times by increasing the residence time of the probe/sleeve inside the oxygen-rich flame or by varying the flame position. At different flame heights, nanorods having higher length-to-diameter aspect-ratio can be synthesized. A lattice spacing of {approx}0.26 nm was measured for the synthesized nanorods, which can be closely correlated with the (0 0 2) interplanar spacing of hexagonal ZnO (Wurtzite) cells

  9. High-resolution continuum source electrothermal atomic absorption spectrometry: Linearization of the calibration curves within a broad concentration range

    Energy Technology Data Exchange (ETDEWEB)

    Katskov, Dmitri, E-mail: katskovda@tut.ac.za [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Hlongwane, Miranda [Tshwane University of Technology, Chemistry Department, Pretoria 0001 (South Africa); Heitmann, Uwe [German Aerospace Center, Rose-Luxemburg Str. 2, 10178 Berlin (Germany); Florek, Stefan [ISAS-Leibniz-Institut fuer Analytische Wissenschaften e.V., Albert-Einstein-Str. 9,12489 Berlin (Germany)

    2012-05-15

    The calculation algorithm suggested provides linearization of the calibration curves in high-resolution continuum source electrothermal atomic absorption spectrometry. The algorithm is based on the modification of the function wavelength-integrated absorbance vs. concentration of analyte vapor in the absorption volume. According to the suggested approach, the absorption line is represented by a triangle for low and trapezium for high analyte vapor concentration in the absorption volume. The respective semi-empirical formulas include two linearization parameters, which depend on properties of the absorption line and characteristics of the atomizer and spectrometer. The parameters can be approximately evaluated from the theory and determined in practice from the original broad-range calibration curve. The parameters were found and the proposed calculation algorithm verified in the experiments on direct determination of Ag, Cd, Cu, Fe, Mn and Pb in the solutions within a concentration ranges from 0.15 to 625 {mu}g{center_dot}L{sup -1} using tube, platform tube and filter furnace atomizers. The use of various atomizers, lines, elements and atomization temperatures made possible the simulation of various practical analytical conditions. It was found that the algorithm and optimal linearization parameters made it possible to obtain for each line and atomizer linear approximations of the calibration curves within 3-4 orders of magnitude with correlation coefficients close to 0.999. The algorithm makes possible to employ a single line for the direct element determination over a broad concentration range. The sources of errors and the possibility of a priori theoretical evaluation of the linearization parameters are discussed. - Highlights: Black-Right-Pointing-Pointer New calculation algorithm for HR-CS ET AAS measurements was proposed and applied. Black-Right-Pointing-Pointer The suggested formulas include two parameters to be determined experimentally. Black

  10. Interfacing transitions of different alkali atoms and telecom bands using one narrowband photon pair source

    DEFF Research Database (Denmark)

    Schunk, Gerhard; Vogl, Ulrich; Strekalov, Dmitry V.

    2015-01-01

    Quantum information technology strongly relies on the coupling of optical photons with narrowband quantum systems, such as quantum dots, color centers, and atomic systems. This coupling requires matching the optical wavelength and bandwidth to the desired system, which presents a considerable pro...

  11. Distribution of Fe atom density in a dc magnetron sputtering plasma source measured by laser-induced fluorescence imaging spectroscopy

    Science.gov (United States)

    Shibagaki, K.; Nafarizal, N.; Sasaki, K.; Toyoda, H.; Iwata, S.; Kato, T.; Tsunashima, S.; Sugai, H.

    2003-10-01

    Magnetron sputtering discharge is widely used as an efficient method for thin film fabrication. In order to achieve the optimized fabrication, understanding of the kinetics in plasmas is essential. In the present work, we measured the density distribution of sputtered Fe atoms using laser-induced fluorescence imaging spectroscopy. A dc magnetron plasma source with a Fe target was used. An area of 20 × 2 mm in front of the target was irradiated by a tunable laser beam having a planar shape. The picture of laser-induced fluorescence on the laser beam was taken using an ICCD camera. In this way, we obtained the two-dimensional image of the Fe atom density. As a result, it has been found that the Fe atom density observed at a distance of several centimeters from the target is higher than that adjacent to the target, when the Ar gas pressure was relatively high. It is suggested from this result that some gas-phase production processes of Fe atoms are available in the plasma. This work has been performed under the 21st Century COE Program by the Ministry of Education, Culture, Sports, Science and Technology in Japan.

  12. Femtosecond electron diffraction. Next generation electron sources for atomically resolved dynamics

    International Nuclear Information System (INIS)

    Hirscht, Julian

    2015-08-01

    Three instruments for femtosecond electron diffraction (FED) experiments were erected, partially commissioned and used for first diffraction experiments. The Relativistic Electron Gun for Atomic Exploration (REGAE) was completed by beamline elements including supports, a specimen chamber and dark current or electron beam collimating elements such that the commissioning process, including first diffraction experiments in this context, could be started. The temporal resolution of this machine is simulated to be 25 fs (fwhm) short, while a transverse coherence length of 30 nm (fwhm) is feasible to resolve proteins on this scale. Whether this machine is capable of meeting these predictions or whether the dynamics of the electron beam will stay limited by accelerator components, is not finally determined by the end of this work, because commissioning and improvement of accelerator components is ongoing. Simultaneously, a compact DC electron diffraction apparatus, the E-Gun 300, designed for solid and liquid specimens and a target electron energy of 300 keV, was built. Fundamental design issues of the high potential carrying and beam generating components occurred and are limiting the maximum potential and electron energy to 120 keV. Furthermore, this is limiting the range of possible applications and consequently the design and construction of a brand new instrument began. The Femtosecond Electron Diffraction CAmera for Molecular Movies (FED-CAMM) bridges the performance problems of very high electric potentials and provides optimal operational conditions for all applied electron energies up to 300 keV. The variability of gap spacings and optimized manufacturing of the high voltage electrodes lead to the best possible electron pulse durations obtainable with a compact DC setup, that does not comprise of rf-structures. This third apparatus possesses pulse durations just a few tenth femtoseconds apart from the design limit of the highly relativistic REGAE and combines the

  13. Femtosecond electron diffraction. Next generation electron sources for atomically resolved dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Hirscht, Julian

    2015-08-15

    Three instruments for femtosecond electron diffraction (FED) experiments were erected, partially commissioned and used for first diffraction experiments. The Relativistic Electron Gun for Atomic Exploration (REGAE) was completed by beamline elements including supports, a specimen chamber and dark current or electron beam collimating elements such that the commissioning process, including first diffraction experiments in this context, could be started. The temporal resolution of this machine is simulated to be 25 fs (fwhm) short, while a transverse coherence length of 30 nm (fwhm) is feasible to resolve proteins on this scale. Whether this machine is capable of meeting these predictions or whether the dynamics of the electron beam will stay limited by accelerator components, is not finally determined by the end of this work, because commissioning and improvement of accelerator components is ongoing. Simultaneously, a compact DC electron diffraction apparatus, the E-Gun 300, designed for solid and liquid specimens and a target electron energy of 300 keV, was built. Fundamental design issues of the high potential carrying and beam generating components occurred and are limiting the maximum potential and electron energy to 120 keV. Furthermore, this is limiting the range of possible applications and consequently the design and construction of a brand new instrument began. The Femtosecond Electron Diffraction CAmera for Molecular Movies (FED-CAMM) bridges the performance problems of very high electric potentials and provides optimal operational conditions for all applied electron energies up to 300 keV. The variability of gap spacings and optimized manufacturing of the high voltage electrodes lead to the best possible electron pulse durations obtainable with a compact DC setup, that does not comprise of rf-structures. This third apparatus possesses pulse durations just a few tenth femtoseconds apart from the design limit of the highly relativistic REGAE and combines the

  14. Diffusion Flame Extinction in a Low Strain Flow

    Science.gov (United States)

    Sutula, Jason; Jones, Joshua; Torero, Jose L.; Borlik, Jeffrey; Ezekoye, Ofodike A.

    1997-01-01

    Diffusion flames are of great interest in fire safety and many industrial processes. Many parameters significantly affect the flame structure, shape and stability, of particular importance are the constraints imposed by geometrical boundaries. Physical boundaries determine the characteristics of the flow, affect heat, fuel, and oxidizer transport from and towards the flame and can act as heat sinks or heat sources. As a result, the existence of a flame, its shape and nature are intimately related to the geometrical characteristics of the environment that surrounds it. The counter-flow configuration provides a constant strain flow, therefore, is ideal to study the structure of diffusion flames. Most studies have concentrated on the high velocity, high strain limit, since buoyantly induced instabilities will disintegrate the planar flame as the velocity decreases. Only recently, experimental studies in micro-gravity conditions have begun to explore the low strain regimes. The main objective of these on-going studies is to determine the effect of radiative heat losses and variable strain on the structure and radiation-induced extinction of diffusion flames. For these programs, size, geometry, and experimental conditions have been chosen to keep the flame unaffected by the physical boundaries. Whether is the burning of condensed or gaseous fuels, for most real situations the boundaries impose a significant effect on the nature of the flame. There is, therefore, a need to better understand the effect that geometrical constraints (i.e. flow nonperpendicular to a fuel surface, heat losses to the boundaries, etc.) might have on the final characteristics of a diffusion flame. Preliminary experiments have shown that, in the absence of gravity, and depending on the distance from the flame to the boundary, three characteristically different regimes can be observed. Close to the boundary, the flame is parabolic, very thin and blue, almost soot-less. Diffusion is the main

  15. Two-photon excitation of higher sodium levels and population transfer in a flame

    International Nuclear Information System (INIS)

    Dijk, C.A. van.

    1978-01-01

    Studies of the higher excited states of alkali atoms in the inelastic collisional interaction between excited alkali atoms and flame particles have been made. The emphasis is on an exploration of the possibilities that a flame, in combination with a laser, offers for such studies, rather than on obtaining detailed information concerning collisional transitions. Sodium atoms in a H 2 -O 2 -Ar flame at atmospheric pressure and a temperature of 1800 K were chosen as the system to be investigated. (C.F.)

  16. An open source digital servo for atomic, molecular, and optical physics experiments

    Energy Technology Data Exchange (ETDEWEB)

    Leibrandt, D. R., E-mail: david.leibrandt@nist.gov; Heidecker, J. [National Institute of Standards and Technology, Boulder, Colorado 80305 (United States)

    2015-12-15

    We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of {sup 27}Al{sup +} in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

  17. An open source digital servo for atomic, molecular, and optical physics experiments

    Science.gov (United States)

    Leibrandt, D. R.; Heidecker, J.

    2015-12-01

    We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27Al+ in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser.

  18. An open source digital servo for atomic, molecular, and optical physics experiments

    International Nuclear Information System (INIS)

    Leibrandt, D. R.; Heidecker, J.

    2015-01-01

    We describe a general purpose digital servo optimized for feedback control of lasers in atomic, molecular, and optical physics experiments. The servo is capable of feedback bandwidths up to roughly 1 MHz (limited by the 320 ns total latency); loop filter shapes up to fifth order; multiple-input, multiple-output control; and automatic lock acquisition. The configuration of the servo is controlled via a graphical user interface, which also provides a rudimentary software oscilloscope and tools for measurement of system transfer functions. We illustrate the functionality of the digital servo by describing its use in two example scenarios: frequency control of the laser used to probe the narrow clock transition of 27 Al + in an optical atomic clock, and length control of a cavity used for resonant frequency doubling of a laser

  19. Thermodynamics of various F420 coenzyme models as sources of electrons, hydride ions, hydrogen atoms and protons in acetonitrile.

    Science.gov (United States)

    Xia, Ke; Shen, Guang-Bin; Zhu, Xiao-Qing

    2015-06-14

    32 F420 coenzyme models with alkylation of the three different N atoms (N1, N3 and N10) in the core structure (XFH(-)) were designed and synthesized and the thermodynamic driving forces (defined in terms of the molar enthalpy changes or the standard redox potentials in this work) of the 32 XFH(-) releasing hydride ions, hydrogen atoms and electrons, the thermodynamic driving forces of the 32 XFH˙ releasing protons and hydrogen atoms and the thermodynamic driving forces of XF(-)˙ releasing electrons in acetonitrile were determined using titration calorimetry and electrochemical methods. The effects of the methyl group at N1, N3 and N10 and a negative charge on N1 and N10 atoms on the six thermodynamic driving forces of the F420 coenzyme models and their related reaction intermediates were examined; the results show that seating arrangements of the methyl group and the negative charge have remarkably different effects on the thermodynamic properties of the F420 coenzyme models and their related reaction intermediates. The effects of the substituents at C7 and C8 on the six thermodynamic driving forces of the F420 coenzyme models and their related reaction intermediates were also examined; the results show that the substituents at C7 and C8 have good Hammett linear free energy relationships with the six thermodynamic parameters. Meanwhile, a reasonable determination of possible reactions between members of the F420 family and NADH family in vivo was given according to a thermodynamic analysis platform constructed using the elementary step thermodynamic parameter of F420 coenzyme model 2FH(-) and NADH model MNAH releasing hydride ions in acetonitrile. The information disclosed in this work can not only fill a gap in the chemical thermodynamics of F420 coenzyme models as a class of very important organic sources of electrons, hydride ions, hydrogen atoms and protons, but also strongly promote the fast development of the chemistry and applications of F420 coenzyme.

  20. Get Your Atoms in Order--An Open-Source Implementation of a Novel and Robust Molecular Canonicalization Algorithm.

    Science.gov (United States)

    Schneider, Nadine; Sayle, Roger A; Landrum, Gregory A

    2015-10-26

    Finding a canonical ordering of the atoms in a molecule is a prerequisite for generating a unique representation of the molecule. The canonicalization of a molecule is usually accomplished by applying some sort of graph relaxation algorithm, the most common of which is the Morgan algorithm. There are known issues with that algorithm that lead to noncanonical atom orderings as well as problems when it is applied to large molecules like proteins. Furthermore, each cheminformatics toolkit or software provides its own version of a canonical ordering, most based on unpublished algorithms, which also complicates the generation of a universal unique identifier for molecules. We present an alternative canonicalization approach that uses a standard stable-sorting algorithm instead of a Morgan-like index. Two new invariants that allow canonical ordering of molecules with dependent chirality as well as those with highly symmetrical cyclic graphs have been developed. The new approach proved to be robust and fast when tested on the 1.45 million compounds of the ChEMBL 20 data set in different scenarios like random renumbering of input atoms or SMILES round tripping. Our new algorithm is able to generate a canonical order of the atoms of protein molecules within a few milliseconds. The novel algorithm is implemented in the open-source cheminformatics toolkit RDKit. With this paper, we provide a reference Python implementation of the algorithm that could easily be integrated in any cheminformatics toolkit. This provides a first step toward a common standard for canonical atom ordering to generate a universal unique identifier for molecules other than InChI.

  1. Spatial distributions of H, CN, and C2 in a diamond growing oxyacetylene flame

    NARCIS (Netherlands)

    Klein-Douwel, R.J.H.; Meulen, ter J.J.

    1998-01-01

    Two-dimensional laser-induced fluorescence (2D-LIF) measurements are applied to the chemical vapor deposition (CVD) of diamond by an oxyacetylene flame to visualize the distributions of atomic hydrogen, C2, and CN in the gas phase during diamond growth. Experiments are carried out in laminar flames

  2. International Atomic Energy Agency searches for discarded radioactive sources in Republic of Georgia

    International Nuclear Information System (INIS)

    2000-01-01

    The document informs about the first aerial reconnaissance of the IAEA (planned to take place between 23 May-16 June 2000) to track down discarded radiation sources in the Republic of Georgia. The aim of the IAEA mission is to provide reasonable assurance that there are no serious radiation risk from discarded radiation sources to the population

  3. Atomic properties of the elements and cosmic ray composition at the source

    International Nuclear Information System (INIS)

    Casse, M.; Goret, P.; Cesarsky, C.J.

    1975-01-01

    Possible correlations between the abundances of cosmic rays at the source and the solar system abundances are discussed. Cosmic ray source abundances could be explained if the particles are accelerated to injection energies in a dilute, moderately hot plasma, from which they escape in a rigidity dependant fashion [fr

  4. Strained flamelets for turbulent premixed flames II: Laboratory flame results

    Energy Technology Data Exchange (ETDEWEB)

    Kolla, H.; Swaminathan, N. [Department of Engineering, Cambridge University, Cambridge CB2 1PZ (United Kingdom)

    2010-07-15

    The predictive ability of strained flamelets model for turbulent premixed flames is assessed using Reynolds Averaged Navier Stokes (RANS) calculations of laboratory flames covering a wide range of conditions. Reactant-to-product (RtP) opposed flow laminar flames parametrised using the scalar dissipation rate of reaction progress variable are used as strained flamelets. Two turbulent flames: a rod stabilised V-flame studied by Robin et al. [Combust. Flame 153 (2008) 288-315] and a set of pilot stabilised Bunsen flames studied by Chen et al. [Combust. Flame 107 (1996) 223-244] are calculated using a single set of model parameters. The V-flame corresponds to the corrugated flamelets regime. The strained flamelet model and an unstrained flamelet model yield similar predictions which are in good agreement with experimental measurements for this flame. On the other hand, for the Bunsen flames which are in the thin reaction zones regime, the unstrained flamelet model predicts a smaller flame brush compared to experiment. The predictions of the strained flamelets model allowing for fluid-dynamics stretch induced attenuation of the chemical reaction are in good agreement with the experimental data. This model predictions of major and minor species are also in good agreement with experimental data. The results demonstrate that the strained flamelets model using the scalar dissipation rate can be used across the combustion regimes. (author)

  5. Nonpremixed flame in a counterflow under electric fields

    KAUST Repository

    Park, Daegeun

    2016-05-08

    Electrically assisted combustion has been studied in order to control or improve flame characteristics, and emphasizing efficiency and emission regulation. Many phenomenological observations have been reported on the positive impact of electric fields on flame, however there is a lack of detailed physical mechanisms for interpreting these. To clarify the effects of electric fields on flame, I have investigated flame structure, soot formation, and flow field with ionic wind electrical current responses in nonpremixed counterflow flames. The effects of direct current (DC) electric field on flame movement and flow field was also demonstrated in premixed Bunsen flames. When a DC electric field was applied to a lower nozzle, the flames moved toward the cathode side due to Lorentz force action on the positive ions, soot particles simultaneously disappeared completely and laser diagnostics was used to identify the results from the soot particles. To understand the effects of an electric field on flames, flow visualization was performed by Mie scattering to check the ionic wind effect, which is considered to play an important role in electric field assisted combustion. Results showed a bidirectional ionic wind, with a double-stagnant flow configuration, which blew from the flame (ionic source) toward both the cathode and the anode. This implies that the electric field affects strain rate and the axial location of stoichiometry, important factors in maintaining nonpremixed counterflow flames; thus, soot formation of the counterflow flame can also be affected by the electric field. In a test of premixed Bunsen flames having parallel electrodes, flame movement toward the cathode and bidirectional ionic wind were observed. Using PIV measurement it was found that a created radial velocity caused by positive ions (i.e. toward a cathode), was much faster than the velocity toward the anode. Even in a study of alternating current (AC) electric fields, bidirectional ionic wind could

  6. Emission flame spectrophotometry of chromium, cobalt, nickel trace amounts

    International Nuclear Information System (INIS)

    Prudnikov, Y.D.; Shapkina, Y.S.

    1976-01-01

    Chromium, cobalt, and nickel were determined in a flame spectrophotometer with a dual diffraction monochromator, DFS-12, in a high-temperature nitrogen-acetylene flame. The effect of ionization and the elements in the oxidizing flame was small. The lower limit of detection for the three elements is 1x10 -2 to 1 x10 -3 μg/ml, and the high selectivity of the analysis permits determining down to 10 -4 % Cr and Ni and to 10 -3 % Co. These elements may be determined in rocks and minerals from solutions prepared for analysis for alkali and alkali-earth elements. The possibilities of emission flame spectrophotometry are as great as those of atomic-absorption analysis, and it may be used for determining Cr, Co, and Ni in rocks and minerals, especially pure substances, metals, and other materials

  7. Analyzing Capabilities of Commercial and Open-Source Routers to Implement Atomic BGP

    Directory of Open Access Journals (Sweden)

    A. Cvjetić

    2010-06-01

    Full Text Available The paper analyzes implementations of BGP protocol on commercial and open-source routers and presents how some existing BGP extensions and routing table isolation mechanisms may be used to solve issues found in standard BGP implementation.

  8. Low-kilovolt coherent electron diffractive imaging instrument based on a single-atom electron source

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun-Yueh [Department of Physics, National Taiwan University, Taipei 10617, Taiwan (China); Chang, Wei-Tse; Chen, Yi-Sheng; Hwu, En-Te; Chang, Chia-Seng; Hwang, Ing-Shouh, E-mail: ishwang@phys.sinica.edu.tw [Institute of Physics, Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Hsu, Wei-Hao [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan (China)

    2016-03-15

    In this work, a transmission-type, low-kilovolt coherent electron diffractive imaging instrument was constructed. It comprised a single-atom field emitter, a triple-element electrostatic lens, a sample holder, and a retractable delay line detector to record the diffraction patterns at different positions behind the sample. It was designed to image materials thinner than 3 nm. The authors analyzed the asymmetric triple-element electrostatic lens for focusing the electron beams and achieved a focused beam spot of 87 nm on the sample plane at the electron energy of 2 kV. High-angle coherent diffraction patterns of a suspended graphene sample corresponding to (0.62 Å){sup −1} were recorded. This work demonstrated the potential of coherent diffractive imaging of thin two-dimensional materials, biological molecules, and nano-objects at a voltage between 1 and 10 kV. The ultimate goal of this instrument is to achieve atomic resolution of these materials with high contrast and little radiation damage.

  9. Flaming on YouTube

    NARCIS (Netherlands)

    Moor, Peter J.; Heuvelman, A.; Verleur, R.

    2010-01-01

    In this explorative study, flaming on YouTube was studied using surveys of YouTube users. Flaming is defined as displaying hostility by insulting, swearing or using otherwise offensive language. Three general conclusions were drawn. First, although many users said that they themselves do not flame,

  10. DeVelopment of the high-intensity polarized H- source with proton charge exchange on sodium optically oriented atoms

    International Nuclear Information System (INIS)

    Zelenskij, A.N.; Kokhanovskij, S.A.

    1982-01-01

    The results of experimental study on the source of polarized H - ions at polarized electron capture by proton from optically oriented sodium atoms are presented. Circular-polarized dye laser radiation with lamp pumping is used for polarization of highly dense sodium vapors in the pulsed mode. A facility for polarization measurement in the ion source is described. Dependence of the counting rate of metastables for the right and left circular radiation polarization in respect to wave length is presented. The results of measuring the degree of polarization under change of sodium density are revealed. The measurements have disclosed that obtaining of high polarization degree at 20-30% charge exchange effectiveness is possible but large radiation power is required. Use of a dense charge exchange target provides high effectiveness of hte whole polarization process. Yield of polarized H - ions can approach 10 μA/1 mA of the initial proton current

  11. Continuous-wave, single-frequency 229  nm laser source for laser cooling of cadmium atoms.

    Science.gov (United States)

    Kaneda, Yushi; Yarborough, J M; Merzlyak, Yevgeny; Yamaguchi, Atsushi; Hayashida, Keitaro; Ohmae, Noriaki; Katori, Hidetoshi

    2016-02-15

    Continuous-wave output at 229 nm for the application of laser cooling of Cd atoms was generated by the fourth harmonic using two successive second-harmonic generation stages. Employing a single-frequency optically pumped semiconductor laser as a fundamental source, 0.56 W of output at 229 nm was observed with a 10-mm long, Brewster-cut BBO crystal in an external cavity with 1.62 W of 458 nm input. Conversion efficiency from 458 nm to 229 nm was more than 34%. By applying a tapered amplifier (TA) as a fundamental source, we demonstrated magneto-optical trapping of all stable Cd isotopes including isotopes Cd111 and Cd113, which are applicable to optical lattice clocks.

  12. Determination of silicon and aluminum in silicon carbide nanocrystals by high-resolution continuum source graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Dravecz, Gabriella; Bencs, László; Beke, Dávid; Gali, Adam

    2016-01-15

    The determination of Al contaminant and the main component Si in silicon carbide (SiC) nanocrystals with the size-distribution of 1-8nm dispersed in an aqueous solution was developed using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS-GFAAS). The vaporization/atomization processes were investigated in a transversally heated graphite atomizer by evaporating solution samples of Al and Si preserved in various media (HCl, HNO3). For Si, the best results were obtained by applying a mixture of 5µg Pd plus 5µg Mg, whereas for Al, 10µg Mg (each as nitrate solution) was dispensed with the samples, but the results obtained without modifier were found to be better. This way a maximum pyrolysis temperature of 1200°C for Si and 1300°C for Al could be used, and the optimum (compromise) atomization temperature was 2400°C for both analytes. The Si and Al contents of different sized SiC nanocrystals, dispersed in aqueous solutions, were determined against aqueous (external) calibration standards. The correlation coefficients (R values) of the calibrations were found to be 0.9963 for Si and 0.9991 for Al. The upper limit of the linear calibration range was 2mg/l Si and 0.25mg/l Al. The limit of detection was 3µg/l for Si and 0.5µg/l for Al. The characteristic mass (m0) was calculated to be 389pg Si and 6.4pg Al. The Si and Al content in the solution samples were found to be in the range of 1.0-1.7mg/l and 0.1-0.25mg/l, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Atomic processes and equation of state of high Z plasmas for EUV sources and their effects on the spatial and temporal evolution of the plasmas

    Science.gov (United States)

    Sasaki, Akira; Sunahara, Atushi; Furukawa, Hiroyuki; Nishihara, Katsunobu; Nishikawa, Takeshi; Koike, Fumihiro

    2016-03-01

    Laser-produced plasma (LPP) extreme ultraviolet (EUV) light sources have been intensively investigated due to potential application to next-generation semiconductor technology. Current studies focus on the atomic processes and hydrodynamics of plasmas to develop shorter wavelength sources at λ = 6.x nm as well as to improve the conversion efficiency (CE) of λ = 13.5 nm sources. This paper examines the atomic processes of mid-z elements, which are potential candidates for λ = 6.x nm source using n=3-3 transitions. Furthermore, a method to calculate the hydrodynamics of the plasmas in terms of the initial interaction between a relatively weak prepulse laser is presented.

  14. A Space Experiment to Measure the Atomic Oxygen Erosion of Polymers and Demonstrate a Technique to Identify Sources of Silicone Contamination

    Science.gov (United States)

    Banks, Bruce A.; deGroh, Kim K.; Baney-Barton, Elyse; Sechkar, Edward A.; Hunt, Patricia K.; Willoughby, Alan; Bemer, Meagan; Hope, Stephanie; Koo, Julie; Kaminski, Carolyn; hide

    1999-01-01

    A low Earth orbital space experiment entitled, "Polymers Erosion And Contamination Experiment", (PEACE) has been designed as a Get-Away Special (GAS Can) experiment to be accommodated as a Shuttle in-bay environmental exposure experiment. The first objective is to measure the atomic oxygen erosion yields of approximately 40 different polymeric materials by mass loss and erosion measurements using atomic force microscopy. The second objective is to evaluate the capability of identifying sources of silicone contamination through the use of a pin-hole contamination camera which utilizes environmental atomic oxygen to produce a contaminant source image on an optical substrate.

  15. Stability of various entanglements in the interaction between two two-level atoms with a quantized field under the influences of several decay sources

    Science.gov (United States)

    Valizadeh, Sh.; Tavassoly, M. K.; Yazdanpanah, N.

    2018-02-01

    In this paper the interaction between two two-level atoms with a single-mode quantized field is studied. To achieve exact information about the physical properties of the system, one should take into account various sources of dissipation such as photon leakage of cavity, spontaneous emission rate of atoms, internal thermal radiation of cavity and dipole-dipole interaction between the two atoms. In order to achieve the desired goals, we obtain the time evolution of the associated density operator by solving the time-dependent Lindblad equation corresponding to the system. Then, we evaluate the temporal behavior of total population inversion and quantum entanglement between the evolved subsystems, numerically. We clearly show that how the damping parameters affect on the dynamics of considered properties. By analyzing the numerical results, we observe that increasing each of the damping sources leads to faster decay of total population inversion. Also, it is observed that, after starting the interaction, the entanglement between one atom with other parts of the system as well as the entanglement between "atom-atom" subsystem and the "field", tend to some constant values very soon. Moreover, the stable values of entanglement are reduced via increasing the damping factor Γ A (ΓA^{(1)} = ΓA^{(2)} = ΓA ) where ΓA is the spontaneous emission rate of each atom. In addition, we find that by increasing the thermal photons, the entropies (entanglements) tend sooner to some increased stable values. Accordingly, we study the atom-atom entanglement by evaluating the concurrence under the influence of dissipation sources, too. At last, the effects of dissipation sources on the genuine tripartite entanglement between the three subsystems include of two two-level atoms and a quantized field are numerically studied. Due to the important role of stationary entanglement in quantum information processing, our results may provide useful hints for practical protocols which require

  16. Stratified turbulent Bunsen flames : flame surface analysis and flame surface density modelling

    NARCIS (Netherlands)

    Ramaekers, W.J.S.; Oijen, van J.A.; Goey, de L.P.H.

    2012-01-01

    In this paper it is investigated whether the Flame Surface Density (FSD) model, developed for turbulent premixed combustion, is also applicable to stratified flames. Direct Numerical Simulations (DNS) of turbulent stratified Bunsen flames have been carried out, using the Flamelet Generated Manifold

  17. Atmospheric-pressure solution-cathode glow discharge: A versatile ion source for atomic and molecular mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Andrew J. [Department of Chemistry, Indiana University, Bloomington, IN, 47405 (United States); Williams, Kelsey L. [Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242 (United States); Hieftje, Gary M. [Department of Chemistry, Indiana University, Bloomington, IN, 47405 (United States); Shelley, Jacob T., E-mail: shellj@rpi.edu [Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242 (United States); Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States)

    2017-01-15

    An atmospheric-pressure solution-cathode glow discharge (SCGD) has been evaluated as an ion source for atomic, molecular, and ambient desorption/ionization mass spectrometry. The SCGD consists of a direct-current plasma, supported in the ambient air in the absence of gas flows, and sustained upon the surface of a flowing liquid cathode. Analytes introduced in the flowing liquid, as an ambient gas, or as a solid held near the plasma are vaporized and ionized by interactions within or near the discharge. Introduction of acidic solutions containing metal salts produced bare elemental ions as well as H{sub 2}O, OH{sup −} and NO{sub 3}{sup −} adducts. Detection limits for these elemental species ranged from 0.1 to 4 ppb, working curves spanned more than 4 orders of linear dynamic range, and precision varied between 5 and 16% relative standard deviation. Small organic molecules were also efficiently ionized from solution, and both the intact molecular ion and fragments were observed in the resulting SCGD mass spectra. Fragmentation of molecular species was found to be tunable; high discharge currents led to harder ionization, while low discharge currents produced stronger molecular-ion signals. Ambient gases and solids, desorbed by the plasma from a glass probe, were also readily ionized by the SCGD. Indeed, strong analyte signals were obtained from solid samples placed at least 2 cm from the plasma. These findings indicate that the SCGD might be useful also for ambient desorption/ionization mass spectrometry. Combined with earlier results that showed the SCGD is useful for ionization of labile biomolecules, the results here indicate that the SCGD is a highly versatile ion source capable of providing both elemental and molecular mass-spectral information. - Highlights: • Solution-cathode glow discharge used as an ionization source for mass spectrometry. • SCGD-MS can provide atomic as well as intact molecular mass spectra. • Atomic limits of detection range

  18. Characterization of high-pressure, underexpanded hydrogen-jet flames

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, R.W.; Houf, W.G.; Williams, T.C. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Bourne, B.; Colton, J. [SRI International, 333 Ravenwood Ave., Menlo Park, CA 94025 (United States)

    2007-08-15

    Measurements were performed to characterize the dimensional and radiative properties of large-scale, vertical hydrogen-jet flames. This data is relevant to the safety scenario of a sudden leak in a high-pressure hydrogen containment vessel and will provide a technological basis for determining hazardous length scales associated with unintended hydrogen releases at storage and distribution centers. Jet flames originating from high-pressure sources up to 413 bar (6000 psi) were studied to verify the application of correlations and scaling laws based on lower-pressure subsonic and choked-flow jet flames. These higher pressures are expected to be typical of the pressure ranges in future hydrogen storage vessels. At these pressures the flows exiting the jet nozzle are categorized as underexpanded jets in which the flow is choked at the jet exit. Additionally, the gas behavior departs from that of an ideal-gas and alternate formulations for non-ideal gas must be introduced. Visible flame emission was recorded on video to evaluate flame length and structure. Radiometer measurements allowed determination of the radiant heat flux characteristics. The flame length results show that lower-pressure engineering correlations, based on the Froude number and a non-dimensional flame length, also apply to releases up to 413 bar (6000 psi). Similarly, radiative heat flux characteristics of these high-pressure jet flames obey scaling laws developed for low-pressure, smaller-scale flames and a wide variety of fuels. The results verify that such correlations can be used to a priori predict dimensional characteristics and radiative heat flux from a wide variety of hydrogen-jet flames resulting from accidental releases. (author)

  19. Direct Flame Impingement

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    During the DFI process, high velocity flame jets impinge upon the material being heated, creating a high heat transfer rate. As a result, refractory walls and exhaust gases are cooler, which increases thermal efficiency and lowers NOx emissions. Because the jet nozzles are located a few inches from the load, furnace size can be reduced significantly.

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

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Yasin [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Mehmet Akif Ersoy University, Faculty of Arts & Sciences, Chemistry Department, 15030 Burdur (Turkey); Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Dědina, Jiří, E-mail: dedina@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

    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{sup −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{sup −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. - Highlights: • On-line atomization of gold volatile species for AAS in quartz devices was studied. • Atomization mechanism was proposed and atomization efficiency was estimated. • Possibilities of in-atomizer preconcentration of gold volatile species were assessed.

  1. Flame visualization in power stations

    Energy Technology Data Exchange (ETDEWEB)

    Hulshof, H J.M.; Thus, A W; Verhage, A J.L. [KEMA - Fossil Power Plants, Arnhem (Netherlands)

    1993-01-01

    The shapes and temperature of flames in power stations, fired with powder coal and gas, have been measured optically. Spectral information in the visible and near infrared is used. Coal flames are visualized in the blue part of the spectrum, natural gas flames are viewed in the light of CH-emission. Temperatures of flames are derived from the best fit of the Planck-curve to the thermal radiation spectrum of coal and char, or to that of soot in the case of gas flames. A measuring method for the velocity distribution inside a gas flame is presented, employing pulsed alkali salt injection. It has been tested on a 100 kW natural gas flame. 3 refs., 9 figs.

  2. Activities of the international atomic energy agency on management of disused radioactive sources

    International Nuclear Information System (INIS)

    Vilmos Friedrich; Miaw, S.T.W.

    2001-01-01

    The agency has implemented various activities on management of disused sealed sources for developing countries. The main types of activities are the following: 1. collection, review and publication of up-to-date information and guidance, conference and workshop proceedings; 2. developing and distributing management tools; 3. transfer of technology and know-how through training and other technical co-operation projects; 4. direct assistance to solve specific safety and technical problems

  3. Atomic emission and atomic fluorescence spectroscopy in the direct current plasma

    International Nuclear Information System (INIS)

    Hendrick, M.S.

    1985-01-01

    The Direct Current Plasma (DCP) was investigated as a source for Atomic Emission (AE) and Atomic Fluorescence Spectrometry (AFS). The DCP was optimized for AE analyses using simplex optimization and Box-Behnken partial factorial experimental design, varying argon flows, and plasma position. Results were compared with a univariate search carried out in the region of the simplex optimum. Canonical analysis demonstrated that no true optimum exists for sensitivity, precision, or drift. A stationary ridge, where combinations of conditions gave comparable instrumental responses, was found. The DCP as an excitation source for AFS in a flame was used for diagnostic studies of the DCP. Moving the aerosol introduction tube behind the DCP with respect to the flame improved the characteristics of the DCP as a narrow line source, although self-absorption was observed at high concentrations of metal salt solutions in the DCP. Detection limits for Cd, Co, Cr, Cu, Fe, Mg, Mn, Zn, and Ni were in the low ng/mL region. Theoretical expressions for scatter correction with a two-line technique were derived, although no correction was necessary to achieve accurate results for standard reference materials

  4. In-source laser spectroscopy of polonium isotopes: From atomic physics to nuclear structure

    CERN Multimedia

    Rothe, S

    2014-01-01

    The Resonance Ionization Laser Ion Source RILIS [1] at the CERN-ISOLDE on-line radioactive ion beam facility is essential for ion beam production for the majority of experiments, but it is also powerful tool for laser spectroscopy of rare isotopes. A series of experiments on in-source laser spectroscopy of polonium isotopes [2, 3] revealed the nuclear ground state properties of 191;211;216;218Po. However, limitations caused by the isobaric background of surface-ionized francium isotopes hindered the study of several neutron rich polonium isotopes. The development of the Laser Ion Source and Trap (LIST) [4] and finally its integration at ISOLDE has led to a dramatic suppression of surface ions. Meanwhile, the RILIS laser spectroscopy capabilities have advanced tremendously. Widely tunable titanium:sapphire (Ti:Sa) lasers were installed to complement the established dye laser system. Along with a new data acquisition system [5], this more versatile laser setup enabled rst ever laser spectroscopy of the radioact...

  5. Resistivity of flame plasma in an electric field

    International Nuclear Information System (INIS)

    Ikuta, Kazunari.

    1989-01-01

    A generalized Ohm's law is obtained for a flame plasma in an electric field for the study of arc resistivity in an electromagnetic launcher (EML). The effective resistivity of flame plasma is reduced by the source, which suggests the injection of premixed combustible fuel into the arc plasma in EML in order to reduce the electron energy of the arc. The reduction of electron energy in the arc is desirable to minimize the damage of electrodes in EML. (author)

  6. Evaluation of a new dielectric barrier discharge excitation source for the determination of arsenic with atomic emission spectrometry.

    Science.gov (United States)

    Zhu, Zhenli; He, Haiyang; He, Dong; Zheng, Hongtao; Zhang, Caixiang; Hu, Shenghong

    2014-05-01

    A low power dielectric barrier discharge excitation source was developed to determine arsenic in a cost-effective manner. Arsenic in water was reduced to AsH₃ by hydride generation (HG), which was transported to the miniature dielectric barrier discharge (DBD) excitation source for excitation and optical detection at As 193.7 nm atomic line. The DBD source consists of a quartz tube, a tungsten rod electrode, and a copper coil electrode. The main operation parameters and the potential interferences affecting the determination were investigated. The detection limit for arsenic with the proposed DBD-AES was 4.8 μg L(-1) when the HG products were dried with concentrated H₂SO₄ before introducing to DBD. Repeatability, expressed as the relative standard deviation of the spectral peak height, was 2.8% (n=11) for 0.1 mg L(-1) arsenic solution. The proposed method was successfully applied to the determinations of certified reference material (GBW08605) and nature water samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Experimental study on flame pattern formation and combustion completeness in a radial microchannel

    Science.gov (United States)

    Fan, Aiwu; Minaev, Sergey; Kumar, Sudarshan; Liu, Wei; Maruta, Kaoru

    2007-12-01

    Combustion behavior in a radial microchannel with a gap of 2.0 mm and a diameter of 50 mm was experimentally investigated. In order to simulate the heat recirculation, which is an essential strategy in microscale combustion devices, positive temperature gradients along the radial flow direction were given to the microchannel by an external heat source. A methane-air mixture was supplied from the center of the top plate through a 4.0 mm diameter delivery tube. A variety of flame patterns, including a stable circular flame and several unstable flame patterns termed unstable circular flame, single and double pelton-like flames, traveling flame and triple flame, were observed in the experiments. The regime diagram of all these flame patterns is presented in this paper. Some characteristics of the various flame patterns, such as the radii of stable and unstable circular flames, major combustion products and combustion efficiencies of all these flame patterns, were also investigated. Furthermore, the effect of the heat recirculation on combustion stability was studied by changing the wall temperature levels.

  8. A new atomic beam polarized ion source for the Triangle Universities Nuclear Laboratory: overview, operating experience, and performance

    International Nuclear Information System (INIS)

    Clegg, T.B.; Karwowski, H.J.; Lemieux, S.K.; Sayer, R.W.; Crosson, E.R.; Hooke, W.M.; Howell, C.R.; Lewis, H.W.; Lovette, A.W.; Pfutzner, H.J.; Sweeton, K.A.; Wilburn, W.S.

    1995-01-01

    A newly constructed source of polarized H ± and D ± ions is described. Atomic H or D beams from a dissociator with a cooled nozzle enter a system of two sextupole magnets and several radio-frequency transitions where they are focused and polarized. They enter a downstream electron-cyclotron-resonance-heated plasma ionizer from which positive ions are extracted. When negative ions are desired, they may be produced from the positive beam by charge-exchange in cesium vapor. Emerging beams are intense, have good polarization, low energy spread, and good optical quality. Descriptions are included for all major systems and for diagnostic procedures used to optimize both the intensity and the polarization of the output H ± or D ± beams obtained. Typical operating experience, performance figures, and a description of routine maintenance procedures are given. ((orig.))

  9. QMCPACK: an open source ab initio quantum Monte Carlo package for the electronic structure of atoms, molecules and solids

    Science.gov (United States)

    Kim, Jeongnim; Baczewski, Andrew D.; Beaudet, Todd D.; Benali, Anouar; Chandler Bennett, M.; Berrill, Mark A.; Blunt, Nick S.; Josué Landinez Borda, Edgar; Casula, Michele; Ceperley, David M.; Chiesa, Simone; Clark, Bryan K.; Clay, Raymond C., III; Delaney, Kris T.; Dewing, Mark; Esler, Kenneth P.; Hao, Hongxia; Heinonen, Olle; Kent, Paul R. C.; Krogel, Jaron T.; Kylänpää, Ilkka; Li, Ying Wai; Lopez, M. Graham; Luo, Ye; Malone, Fionn D.; Martin, Richard M.; Mathuriya, Amrita; McMinis, Jeremy; Melton, Cody A.; Mitas, Lubos; Morales, Miguel A.; Neuscamman, Eric; Parker, William D.; Pineda Flores, Sergio D.; Romero, Nichols A.; Rubenstein, Brenda M.; Shea, Jacqueline A. R.; Shin, Hyeondeok; Shulenburger, Luke; Tillack, Andreas F.; Townsend, Joshua P.; Tubman, Norm M.; Van Der Goetz, Brett; Vincent, Jordan E.; ChangMo Yang, D.; Yang, Yubo; Zhang, Shuai; Zhao, Luning

    2018-05-01

    QMCPACK is an open source quantum Monte Carlo package for ab initio electronic structure calculations. It supports calculations of metallic and insulating solids, molecules, atoms, and some model Hamiltonians. Implemented real space quantum Monte Carlo algorithms include variational, diffusion, and reptation Monte Carlo. QMCPACK uses Slater–Jastrow type trial wavefunctions in conjunction with a sophisticated optimizer capable of optimizing tens of thousands of parameters. The orbital space auxiliary-field quantum Monte Carlo method is also implemented, enabling cross validation between different highly accurate methods. The code is specifically optimized for calculations with large numbers of electrons on the latest high performance computing architectures, including multicore central processing unit and graphical processing unit systems. We detail the program’s capabilities, outline its structure, and give examples of its use in current research calculations. The package is available at http://qmcpack.org.

  10. Supersonic Fe beam source for chromatic aberration-free laser focusing of atoms

    CERN Document Server

    Bosch, R C M; Van der Straten, P; Leeuwen, K A H

    2002-01-01

    A monochromatic Fe beam is generated by heated supersonic expansion of argon seeded with Fe vapor. At a nozzle temperature of 1930 K and 800 torr argon inlet pressure the Fe beam has an axial velocity spread of 8% and intensity of 3 x 10 sup 1 sup 5 s sup - sup 1 sr sup - sup 1 , corresponding to a deposition rate of 10 nm/h at 150 mm from the nozzle. The two-chamber alumina crucibles are chemically stable for liquid Fe. With 400 mm sup 3 Fe we have operated for more than 200 hours without reloading. The power consumption at 1930 K is 750 W. Temperature stability at constant power (without feedback) is better than 30 K. The source is intended for deposition of nano-structures by laser focusing of the Fe beam. The small axial velocity spread virtually eliminates the increase in focal spot size due to chromatic aberration. (authors)

  11. The Advanced Light Source: A new tool for research in atomic physics

    International Nuclear Information System (INIS)

    Schlachter, A.S.

    1990-09-01

    The Advanced Light Source, a third-generation national synchrotron-radiation facility now under construction at the Lawrence Berkeley Laboratory in Berkeley, California, is scheduled to begin serving qualified users across a broad spectrum of research areas in the spring of 1993. Undulators will generate high-brightness, partially coherent, plane polarized, soft-x-ray and ultraviolet (XUV) radiation from below 10 eV to above 2 keV. Wigglers and bend magnets will generate high fluxes of x-rays to photon energies above 10 keV. The ALS will have an extensive research program in which XUV radiation is used to study matter in all its varied gaseous, liquid, and solid forms. 7 refs., 3 figs

  12. Atom Skimmers and Atom Lasers Utilizing Them

    Science.gov (United States)

    Hulet, Randall; Tollett, Jeff; Franke, Kurt; Moss, Steve; Sackett, Charles; Gerton, Jordan; Ghaffari, Bita; McAlexander, W.; Strecker, K.; Homan, D.

    2005-01-01

    Atom skimmers are devices that act as low-pass velocity filters for atoms in thermal atomic beams. An atom skimmer operating in conjunction with a suitable thermal atomic-beam source (e.g., an oven in which cesium is heated) can serve as a source of slow atoms for a magneto-optical trap or other apparatus in an atomic-physics experiment. Phenomena that are studied in such apparatuses include Bose-Einstein condensation of atomic gases, spectra of trapped atoms, and collisions of slowly moving atoms. An atom skimmer includes a curved, low-thermal-conduction tube that leads from the outlet of a thermal atomic-beam source to the inlet of a magneto-optical trap or other device in which the selected low-velocity atoms are to be used. Permanent rare-earth magnets are placed around the tube in a yoke of high-magnetic-permeability material to establish a quadrupole or octupole magnetic field leading from the source to the trap. The atoms are attracted to the locus of minimum magnetic-field intensity in the middle of the tube, and the gradient of the magnetic field provides centripetal force that guides the atoms around the curve along the axis of the tube. The threshold velocity for guiding is dictated by the gradient of the magnetic field and the radius of curvature of the tube. Atoms moving at lesser velocities are successfully guided; faster atoms strike the tube wall and are lost from the beam.

  13. Validation of a mixture-averaged thermal diffusion model for premixed lean hydrogen flames

    Science.gov (United States)

    Schlup, Jason; Blanquart, Guillaume

    2018-03-01

    The mixture-averaged thermal diffusion model originally proposed by Chapman and Cowling is validated using multiple flame configurations. Simulations using detailed hydrogen chemistry are done on one-, two-, and three-dimensional flames. The analysis spans flat and stretched, steady and unsteady, and laminar and turbulent flames. Quantitative and qualitative results using the thermal diffusion model compare very well with the more complex multicomponent diffusion model. Comparisons are made using flame speeds, surface areas, species profiles, and chemical source terms. Once validated, this model is applied to three-dimensional laminar and turbulent flames. For these cases, thermal diffusion causes an increase in the propagation speed of the flames as well as increased product chemical source terms in regions of high positive curvature. The results illustrate the necessity for including thermal diffusion, and the accuracy and computational efficiency of the mixture-averaged thermal diffusion model.

  14. Antimony: a flame fighter

    Science.gov (United States)

    Wintzer, Niki E.; Guberman, David E.

    2015-01-01

    Antimony is a brittle, silvery-white semimetal that conducts heat poorly. The chemical compound antimony trioxide (Sb2O3) is widely used in plastics, rubbers, paints, and textiles, including industrial safety suits and some children’s clothing, to make them resistant to the spread of flames. Also, sodium antimonate (NaSbO3) is used during manufacturing of high-quality glass, which is found in cellular phones.

  15. Intense source of cold cesium atoms based on a two-dimensional magneto–optical trap with independent axial cooling and pushing

    International Nuclear Information System (INIS)

    Huang Jia-Qiang; Wu Chen-Fei; Wang Li-Jun; Yan Xue-Shu; Zhang Jian-Wei

    2016-01-01

    We report our studies on an intense source of cold cesium atoms based on a two-dimensional (2D) magneto–optical trap (MOT) with independent axial cooling and pushing. The new-designed source, proposed as 2D-HP MOT, uses hollow laser beams for axial cooling and a thin pushing laser beam to extract a cold atomic beam. With the independent pushing beam, the atomic flux can be substantially optimized. The total atomic flux maximum obtained in the 2D-HP MOT is 4.02 × 10 10 atoms/s, increased by 60 percent compared to the traditional 2D + MOT in our experiment. Moreover, with the pushing power 10 μW and detuning 0 Γ , the 2D-HP MOT can generate a rather intense atomic beam with the concomitant light shift suppressed by a factor of 20. The axial velocity distribution of the cold cesium beams centers at 6.8 m/s with an FMHW of about 2.8 m/s. The dependences of the atomic flux on the pushing power and detuning are studied in detail. The experimental results are in good agreement with the theoretical model. (paper)

  16. The production of Co-60 sealed sources at the National Atomic Energy Commission

    International Nuclear Information System (INIS)

    Freijo, Jose L.

    2002-01-01

    The production and sale of Cobalt 60 by CNEA is in a key momentum for its consolidation, after passing through situations dose to un viability. The sealed sources demand is assured for the next six years and strongly concentrated in the exportation, mainly to the United States and Europe. The project is economically viable even keeping in mind the necessary investments to assure the growing and sustentability of the business. Therefore, it is possible to have realistic and optimists expectation of growing in the medium and long term. To this respect it results fundamental to confront these activities with a medium and long term vision in order to avoid future uncertainties in the project and, at the same time, to guide and motivate the personnel involved in the efforts that necessarily must be performed to achieve the proposed target. The fundamental steps to be concreted are the construction of new production cells and the transformation of the activities into a private development frame through the creation of a commercial society. (author)

  17. Experimental study of flame stability in biogas premix system

    International Nuclear Information System (INIS)

    Diaz G, Carlos A; Amell A Andres; Cardona Luis F

    2008-01-01

    Utilization of new renewable energy sources have had a special interest in last years looking for decrease the dependence of fossil fuels and the environmental impact generated for them. This work studies experimentally the flame stability of a simulated biogas with a volumetric composition of 60% methane and 40% carbon dioxide. The objective of this study is to obtain information about design and interchangeability of gases in premixed combustion systems that operate with different fuel gases. The critical velocity gradient was the stability criteria used. Utilization of this criteria and the experimental method followed, using a partial premixed burner, stability flame diagram of biogas studied had been obtained. Presence of carbon dioxide has a negative effect in flame stability, decreasing significantly the laminar flame speed and consequently, the stability range of biogas burners because of apparition of blow off.

  18. The FLAME project in Atomki

    International Nuclear Information System (INIS)

    Hunyadi, M.; Iski, N.

    2011-01-01

    Complete text of publication follows. Eleven regions of eight Central European countries have launched the FLAME Project in 2010 (Future Laboratory for the diffusion and Application of innovation in Material Sciences and Engineering) to start and manage a new initiative of a network for innovation activities in the MS and E sector. The project aimed at supporting actors in the field of materials science and exploiting their research and commercial potentials. FLAME partners encourage trans-regional cooperation between R and D centres, universities, start-ups and SMEs by helping companies to distribute their innovations and supporting research in transferring results to the market. The project will implement a new cooperation model: the 'Future Lab', where duly trained 'regional facilitation coaches' will assist SMEs in accessing the whole Central European MS and E market and research potential. Each Future Lab will be specialized on thematic fields and help to make efficient use of local and regional potentials. The three Future Labs will be hosted by the Austrian, Italian and Slovenian partner organizations. Figure 1. Competence and innovation landscape on the FLAME website. Source: http://www.flameurope.eu/mse-actors-145.html As the first step of project implementation in 2011 the competence and innovation maps within the participating regions were elaborated in order to list the relevant actors in the MS and E sector (Figure 1). In 2011, each project partner delegated two regional professionals as facilitation coaches to attend four training weeks across Europe. The facilitation coaches play an active role in the exchange of information and in motivating collaboration between research institutions and enterprises on technology based projects. The training sessions were located at four of the project partners: Kapfenberg/Austria (lead partner - Area m Styria); Warsaw/Poland (PP2 - Warsaw University of Technology); Debrecen/Hungary (PP5 - Atomki); Milan/Italy (PP

  19. Subwoofer and nanotube butterfly acoustic flame extinction

    NARCIS (Netherlands)

    Aliev, Ali E.; Mayo, Nathanael K.; Baughman, Ray H.; Mills, Brent T.; Habtour, Ed

    2017-01-01

    Nonchemical flame control using acoustic waves from a subwoofer and a lightweight carbon nanotube thermoacoustic projector was demonstrated. The intent was to manipulate flame intensity, direction and propagation. The mechanisms of flame suppression using low frequency acoustic waves were discussed.

  20. X-ray photoelectron spectroscopy studies of nitridation on 4H-SiC (0001) surface by direct nitrogen atomic source

    International Nuclear Information System (INIS)

    Chai, J. W.; Pan, J. S.; Zhang, Z.; Wang, S. J.; Chen, Q.; Huan, C. H. A.

    2008-01-01

    A Si 3 N 4 passivation layer has been successfully grown on the 4H-SiC (0001) surface by direct atomic source nitridation at various substrate temperatures. In situ x-ray photoelectron spectroscopy measurements show that higher substrate temperature leads to higher nitridation rate and good crystallinity of the passivation layer. A thin oxynitride layer on the top of the Si 3 N 4 was observed due to the residual O in the vacuum system, but was decomposed during annealing. In the meantime, excess C was found to be effectively removed by the reactive atomic N source

  1. On the theory of turbulent flame velocity

    OpenAIRE

    Bychkov, Vitaly; Akkerman, Vyacheslav; Petchenko, Arkady

    2012-01-01

    The renormalization ideas of self-similar dynamics of a strongly turbulent flame front are applied to the case of a flame with realistically large thermal expansion of the burning matter. In that case a flame front is corrugated both by external turbulence and the intrinsic flame instability. The analytical formulas for the velocity of flame propagation are obtained. It is demonstrated that the flame instability is of principal importance when the integral turbulent length scale is much large...

  2. Investigation of a flame holder geometry effect on flame structure in non-premixed combustion

    International Nuclear Information System (INIS)

    Hashemi, S. A.; Hajialigol, N.; Fattahi, A.; Heydari, R.; Mazaheri, K.

    2013-01-01

    In this paper the effect of flame holder geometry on flame structure is studied. The obtained numerical results using realizable k-ε and β-PDF models show a good agreement with experimental data. The results show that increasing in flame holder length decreases flame length and increases flame temperature. Additionally, it is observed that flame lengths decrease by increasing in flame holder radius and increase for larger radii. Furthermore in various radii, the flame temperature is higher for smaller flame lengths. It was found that behavior of flame structure is mainly affected by the mass flow rate of hot gases that come near the reactant by the recirculation zone.

  3. Investigation of a flame holder geometry effect on flame structure in non-premixed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, S. A.; Hajialigol, N.; Fattahi, A.; Heydari, R. [University of Kashan, Kashan (Iran, Islamic Republic of); Mazaheri, K. [University of Tarbiat Moddares, Tehran (Iran, Islamic Republic of)

    2013-11-15

    In this paper the effect of flame holder geometry on flame structure is studied. The obtained numerical results using realizable k-ε and β-PDF models show a good agreement with experimental data. The results show that increasing in flame holder length decreases flame length and increases flame temperature. Additionally, it is observed that flame lengths decrease by increasing in flame holder radius and increase for larger radii. Furthermore in various radii, the flame temperature is higher for smaller flame lengths. It was found that behavior of flame structure is mainly affected by the mass flow rate of hot gases that come near the reactant by the recirculation zone.

  4. Structure of H2/O2/N2 flames at atmospheric pressure studied by molecular beam mass spectrometry and modeling

    NARCIS (Netherlands)

    Knyazkov, D.A.; Korobeinichev, O.P.; Shmakov, A.G.; Rybitskaya, I.V.; Bolshova, T.A.; Chernov, D.A.; Konnov, A.A.

    2009-01-01

    Structure of laminar premixed flat H2/O2/N2 flames with different equivalence ratios at atmospheric pressure isinvestigated experimentally and by numerical modeling. Concentration profiles of stable species (H2, O2, H2O) as well as of H atoms and OH radicals in the flames were measured using

  5. Polydisperse effects in jet spray flames

    Science.gov (United States)

    Weinberg, Noam; Greenberg, J. Barry

    2018-01-01

    A laminar jet polydisperse spray diffusion flame is analysed mathematically for the first time using an extension of classical similarity solutions for gaseous jet flames. The analysis enables a comparison to be drawn between conditions for flame stability or flame blow-out for purely gaseous flames and for spray flames. It is found that, in contrast to the Schmidt number criteria relevant to gas flames, droplet size and initial spray polydispersity play a critical role in determining potential flame scenarios. Some qualitative agreement for lift-off height is found when comparing predictions of the theory and sparse independent experimental evidence from the literature.

  6. VISIONS: Remote Observations of a Spatially-Structured Filamentary Source of Energetic Neutral Atoms near the Polar Cap Boundary During an Auroral Substorm

    Science.gov (United States)

    Collier, Michael R.; Chornay, D.; Clemmons, J.; Keller, J. W.; Klenzing, J.; Kujawski, J.; McLain, J.; Pfaff, R.; Rowland, D.; Zettergren, M.

    2015-01-01

    We report initial results from the VISualizing Ion Outflow via Neutral atom imaging during a Substorm (VISIONS) rocket that flew through and near several regions of enhanced auroral activity and also sensed regions of ion outflow both remotely and directly. The observed neutral atom fluxes were largest at the lower energies and generally higher in the auroral zone than in the polar cap. In this paper, we focus on data from the latter half of the VISIONS trajectory when the rocket traversed the polar cap region. During this period, many of the energetic neutral atom spectra show a peak at 100 electronvolts. Spectra with peaks around 100 electronvolts are also observed in the Electrostatic Ion Analyzer (EIA) data consistent with these ions comprising the source population for the energetic neutral atoms. The EIA observations of this low energy population extend only over a few tens of kilometers. Furthermore, the directionality of the arriving energetic neutral atoms is consistent with either this spatially localized source of energetic ions extending from as low as about 300 kilometers up to above 600 kilometers or a larger source of energetic ions to the southwest.

  7. Influence of atomization quality on the destruction of hazardous waste compounds

    OpenAIRE

    Kramlich, JC; Seeker, WR; Samuelsen, GS

    1988-01-01

    The correlation between atomization quality and the destruction efficiency of hazardous organic compounds was studied in a turbulent spray flame. The atomization quality was varied by both changing spray nozzle parameters and by inducing disruptive droplet combustion (secondary atomization) within the flame. The primary atomization quality was characterized by laser diagnotic size distribution measurements. The secondary atomization quality was determined from observations of disruptive atomi...

  8. Dynamics and structure of stretched flames

    Energy Technology Data Exchange (ETDEWEB)

    Law, C.K. [Princeton Univ., NJ (United States)

    1993-12-01

    This program aims to gain fundamental understanding on the structure, geometry, and dynamics of laminar premixed flames, and relate these understanding to the practical issues of flame extinction and stabilization. The underlying fundamental interest here is the recent recognition that the response of premixed flames can be profoundly affected by flame stretch, as manifested by flow nonuniformity, flame curvature, and flame/flow unsteadiness. As such, many of the existing understanding on the behavior of premixed flames need to be qualitatively revised. The research program consists of three major thrusts: (1) detailed experimental and computational mapping of the structure of aerodynamically-strained planar flames, with emphasis on the effects of heat loss, nonequidiffusion, and finite residence time on the flame thickness, extent of incomplete reaction, and the state of extinction. (2) Analytical study of the geometry and dynamics of stretch-affected wrinkled flame sheets in simple configurations, as exemplified by the Bunsen flame and the spatially-periodic flame, with emphasis on the effects of nonlinear stretch, the phenomena of flame cusping, smoothing, and tip opening, and their implications on the structure and burning rate of turbulent flames. (3) Stabilization and blowoff of two-dimensional inverted premixed and stabilization and determining the criteria governing flame blowoff. The research is synergistically conducted through the use of laser-based diagnostics, computational simulation of the flame structure with detailed chemistry and transport, and mathematical analysis of the flame dynamics.

  9. Detection of silver nanoparticles in parsley by solid sampling high-resolution-continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Feichtmeier, Nadine S; Leopold, Kerstin

    2014-06-01

    In this work, we present a fast and simple approach for detection of silver nanoparticles (AgNPs) in biological material (parsley) by solid sampling high-resolution-continuum source atomic absorption spectrometry (HR-CS AAS). A novel evaluation strategy was developed in order to distinguish AgNPs from ionic silver and for sizing of AgNPs. For this purpose, atomisation delay was introduced as significant indication of AgNPs, whereas atomisation rates allow distinction of 20-, 60-, and 80-nm AgNPs. Atomisation delays were found to be higher for samples containing silver ions than for samples containing silver nanoparticles. A maximum difference in atomisation delay normalised by the sample weight of 6.27 ± 0.96 s mg(-1) was obtained after optimisation of the furnace program of the AAS. For this purpose, a multivariate experimental design was used varying atomisation temperature, atomisation heating rate and pyrolysis temperature. Atomisation rates were calculated as the slope of the first inflection point of the absorbance signals and correlated with the size of the AgNPs in the biological sample. Hence, solid sampling HR-CS AAS was proved to be a promising tool for identifying and distinguishing silver nanoparticles from ionic silver directly in solid biological samples.

  10. Liftoff and blowoff of a diffusion flame between parallel streams of fuel and air

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Tarrazo, Eduardo [I.N.T.A. Area de Propulsion-Edificio R02, Ctra. Ajalvir, km 4, 28850 Torrejon de Ardoz, Madrid (Spain); Vera, Marcos [Area de Mecanica de Fluidos, Universidad Carlos III de Madrid, 28911 Leganes (Spain); Linan, Amable [Departamento de Motopropulsion y Termofluidodinamica, Universidad Politecnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid (Spain)

    2006-01-01

    A numerical analysis is presented to describe the liftoff and blowoff of a diffusion flame in the mixing layer between two parallel streams of fuel (mainly methane diluted with nitrogen) and air emerging from porous walls. The analysis, which takes into account the effects of thermal expansion, assumes a one-step overall Arrhenius reaction, where the activation energy E is allowed to vary to reproduce the variations of the planar flame propagation velocity with the equivalence ratio. First, we describe the steady flame-front structure when stabilized close to the porous wall (attached flame regime). Then, we analyze the case where the flame front is located far away from the porous wall, at a distance x{sub f}' such that, upstream of the flame front, the mixing layer has a self-similar structure (lifted flame regime). For steady lifted flames, the results, given here in the case when the fuel and air streams are injected with the same velocity, relate U{sub f}'/S{sub L}, the front velocity (relative to the upstream flow) measured with the planar stoichiometric flame velocity, with the Damkohler number D{sub m}=({delta}{sub m}/{delta}{sub L}){sup 2}, based on the thickness, {delta}{sub m}, of the nonreacting mixing layer at the flame-front position and the laminar flame thickness, {delta}{sub L}. For large values of D{sub m}, the results, presented here for a wide range of dilutions of the fuel stream, provide values of the front propagation velocity that are in good agreement with previous experimental results, yielding well-defined conditions for blowoff. The calculated flame-front velocity can also be used to describe the transient flame-front dynamics after ignition by an external energy source.

  11. Transport of inertial particles in a turbulent premixed jet flame

    International Nuclear Information System (INIS)

    Battista, F; Picano, F; Casciola, C M; Troiani, G

    2011-01-01

    The heat release, occurring in reacting flows, induces a sudden fluid acceleration which particles follow with a certain lag, due to their finite inertia. Actually, the coupling between particle inertia and the flame front expansion strongly biases the spatial distribution of the particles, by inducing the formation of localized clouds with different dimensions downstream the thin flame front. A possible indicator of this preferential localization is the so-called Clustering Index, quantifying the departure of the actual particle distribution from the Poissonian, which would correspond to a purely random spatial arrangement. Most of the clustering is found in the flame brush region, which is spanned by the fluctuating instantaneous flame front. The effect is significant also for very light particles. In this case a simple model based on the Bray-Moss-Libby formalism is able to account for most of the deviation from the Poissonian. When the particle inertia increases, the effect is found to increases and persist well within the region of burned gases. The effect is maximum when the particle relaxation time is of the order of the flame front time scale. The evidence of this peculiar source of clustering is here provided by data from a direct numerical simulation of a turbulent premixed jet flame and confirmed by experimental data.

  12. Characteristics of sound radiation from turbulent premixed flames

    Science.gov (United States)

    Rajaram, Rajesh

    Turbulent combustion processes are inherently unsteady and, thus, a source of acoustic radiation, which occurs due to the unsteady expansion of reacting gases. While prior studies have extensively characterized the total sound power radiated by turbulent flames, their spectral characteristics are not well understood. The objective of this research work is to measure the flow and acoustic properties of an open turbulent premixed jet flame and explain the spectral trends of combustion noise. The flame dynamics were characterized using high speed chemiluminescence images of the flame. A model based on the solution of the wave equation with unsteady heat release as the source was developed and was used to relate the measured chemiluminescence fluctuations to its acoustic emission. Acoustic measurements were performed in an anechoic environment for several burner diameters, flow velocities, turbulence intensities, fuels, and equivalence ratios. The acoustic emissions are shown to be characterized by four parameters: peak frequency (Fpeak), low frequency slope (beta), high frequency slope (alpha) and Overall Sound Pressure Level (OASPL). The peak frequency (Fpeak) is characterized by a Strouhal number based on the mean velocity and a flame length. The transfer function between the acoustic spectrum and the spectrum of heat release fluctuations has an f2 dependence at low frequencies, while it converged to a constant value at high frequencies. Furthermore, the OASPL was found to be characterized by (Fpeak mfH)2, which resembles the source term in the wave equation.

  13. FIELD TEST OF THE FLAME QUALITY INDICATOR

    Energy Technology Data Exchange (ETDEWEB)

    Rudin, Andrew M; Butcher, Thomas; Troost, Henry

    2003-02-04

    The flame quality indicator concept was developed at BNL specifically to monitor the brightness of the flame in a small oil burner and to provide a ''call for service'' notification when the brightness has changed from its setpoint, either high or low. In prior development work BNL has explored the response of this system to operational upsets such as excess air changes, fouled atomizer nozzles, poor fuel quality, etc. Insight Technologies, Inc. and Honeywell, Inc. have licensed this technology from the U.S. Department of Energy and have been cooperating to develop product offerings which meet industry needs with an optimal combination of function and price. Honeywell has recently completed the development of the Flame Quality Monitor (FQM or Honeywell QS7100F). This is a small module which connects via a serial cable to the burners primary operating control. Primary advantages of this approach are simplicity, cost, and ease of installation. Call-for-service conditions are output in the form of front panel indicator lights and contact closure which can trigger a range of external communication options. Under this project a field test was conducted of the FQM in cooperation with service organizations in Virginia, Pennsylvania, New Jersey, New York, and Connecticut. At total of 83 field sites were included. At each site the FQM was installed in parallel with another embodiment of this concept--the Insight AFQI. The AFQI incorporates a modem and provides the ability to provide detailed information on the trends in the flame quality over the course of the two year test period. The test site population was comprised of 79.5% boilers, 13.7% warm air furnaces, and 6.8% water heaters. Nearly all were of residential size--with firing rates ranging from 0.6 gallons of oil per hour to 1.25. During the course of the test program the monitoring equipment successfully identified problems including: plugged fuel lines, fouled nozzles, collapsed combustion

  14. Mechanistic aspects of ionic reactions in flames

    DEFF Research Database (Denmark)

    Egsgaard, H.; Carlsen, L.

    1993-01-01

    Some fundamentals of the ion chemistry of flames are summarized. Mechanistic aspects of ionic reactions in flames have been studied using a VG PlasmaQuad, the ICP-system being substituted by a simple quartz burner. Simple hydrocarbon flames as well as sulfur-containing flames have been investigated...

  15. A low temperature investigation of the gas-phase N(2D) + NO reaction. Towards a viable source of N(2D) atoms for kinetic studies in astrochemistry.

    Science.gov (United States)

    Nuñez-Reyes, Dianailys; Hickson, Kevin M

    2018-06-18

    The gas-phase reaction of metastable atomic nitrogen N(2D) with nitric oxide has been investigated over the 296-50 K temperature range using a supersonic flow reactor. As N(2D) could not be produced photolytically in the present work, these excited state atoms were generated instead through the C(3P) + NO → N(2D) + CO reaction while C(3P) atoms were created in situ by the 266 nm pulsed laser photolysis of CBr4 precursor molecules. The kinetics of N(2D) atoms were followed on-resonance by vacuum ultraviolet laser induced fluorescence at 116.7 nm. The measured rate constants for the N(2D) + NO reaction are in excellent agreement with most of the earlier work at room temperature and represent the only available kinetic data for this process below 296 K. The rate constants are seen to increase slightly as the temperature falls to 100 K with a more substantial increase at even lower temperature; a finding which is not reproduced by theoretical work. The prospects for using this chemical source of N(2D) atoms in future studies of a wide range of N(2D) atom reactions are discussed.

  16. Automatic, non-intrusive, flame detection in pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, M.D.; Mehta, S.A.; Moore, R.G. [Calgary Univ., AB (Canada). Dept. of Chemical and Petroleum Engineering; Al-Himyary, T.J. [Al-Himyary Consulting Inc., Calgary, AB (Canada)

    2004-07-01

    Flames have been known to occur within small diameter pipes operating under conditions of high turbulent flow. Although there are several methods of flame detection, few offer remote, non-line-of-site detection. In particular, combustion cannot be detected in cases where flammable mixtures are carried in flare lines, storage tank vents, air drilling or improperly designed purging operations. Combustion noise is being examined as a means to address this problem. A study was conducted in which flames within a small diameter tube were automatically detected using high speed pressure measurements and a newly developed algorithm. Commercially available, high-pressure, dynamic-pressure transducers were used for the measurements. The results of an experimental study showed that combustion noise can be distinguished from other sources of noise by its inverse power law relationship with frequency. This paper presented a newly developed algorithm which provides early detection of flames when combined with high-speed pressure measurements. The algorithm can also separate combustion noise automatically from other sources of noise when combined with other filters. In this study, the noise generated by a fluttering check valve was attenuated using a stop band filter. This detection method was found to be very reliable under the conditions tests, as long as there was no flow restriction between the sensor and the flame. A flow restriction would have resulted in the detection of only the strongest flame noise. It was shown that acoustic flame detection can be applied successfully in flare stacks, industrial burners and turbine combustors. It can be 15 times more sensitive than optical or electrical methods in diagnosing combustion problems with lean burning combustors. It may also be the only method available in applications that require remote, non-line-of-sight detection. 11 refs., 3 tabs., 15 figs.

  17. Iron Oxide Doped Alumina-Zirconia Nanoparticle Synthesis by Liquid Flame Spray from Metal Organic Precursors

    OpenAIRE

    Juha-Pekka Nikkanen; Helmi Keskinen; Mikko Aromaa; Mikael Järn; Tomi Kanerva; Erkki Levänen; Jyrki M. Mäkelä; Tapio Mäntylä

    2008-01-01

    The liquid flame spray (LFS) method was used to make iron oxide doped alumina-zirconia nanoparticles. Nanoparticles were generated using a turbulent, high-temperature (Tmax⁡∼3000 K) H2-O2 flame. The precursors were aluminium-isopropoxide, zirconium-n-propoxide, and ferrocene in xylene solution. The solution was atomized into micron-sized droplets by high velocity H2 flow and introduced into the flame where nanoparticles were formed. The particle morphology, size, phase, and chemical compositi...

  18. Study of the Dissociative Processes in O{sub 2} Discharges. Development of an Atomic Oxygen Beam Source; Etude de la dissociation de O{sub 2} dans les decharges d'oxygene. Application a la realisation de sources d'atomes

    Energy Technology Data Exchange (ETDEWEB)

    Pagnon, Daniel

    1992-09-24

    The first part of this work is devoted to the study of dissociative processes in an oxygen glow discharge at low pressure (0,1-5 Torr, 1-80 mA). The kinetics of oxygen atoms has been determined supported by the measurements of atomic concentrations by VUV absorption spectroscopy and actinometry. The reaction coefficients for dissociative excitation and direct excitation of oxygen atoms have been calculated using the cross sections of the literature and a previously calculated EEDF. It has been demonstrated that dissociative excitation is negligible in respect with direct excitation for dissociation rates smaller than 2,5 %. An upper limit of 20 % for dissociative rates is observed. This limit has been explained by the increase of the atomic recombination at the discharge wall with increasing wall temperature. Using all these results, we have designed and optimized a source of oxygen atoms which has then been adapted on a MBE device. The spatial distribution of the atomic density has been measured in molecular jet by laser induced fluorescence (LIF) and Resonant Multi-Photon Ionization (RMPI). A stimulated emission has been evidenced and the coefficient for this process evaluated. A model for the effusion of atoms has been developed from which the flow of atoms on the sample can be predicted. This source has already been used in industrial MBE devices for in-situ oxidation of copper films, superconductors, and substrates for VLSI high speed applications. The methodology of this work and the diagnostics developed can be applied to other kinds of discharges, of other molecular gases, to design sources of atoms for the treatment of large area samples. (author) [French] Ce travail debute par l'etude de la dissociation dans une decharge luminescente d'oxygene a basse pression (0,1-5 torr, 1-80 ma). La cinetique des atomes d'oxygene a ete etablie a partir de la mesure des concentrations atomiques par spectroscopie d'absorption vuv et par actinometrie. Les coefficients de

  19. Upgrade for detection system of JARREL ASH 70-000 atomic emission spectrography with source of arc - spark

    International Nuclear Information System (INIS)

    Santa Cruz D E; Grau F N; Bellavigna H J; Garavaglia R N; Fernandez R O; Servant R

    2012-01-01

    Methodologies used in spectrochemical analysis have showed breakthroughs in last decades due to the newest digital technologies. The simultaneous determination of multiple elements in a short time has been allowed by the development of solid state multichannel detectors. Since its beginning CNEA has developed several spectroscopic methodologies that have been applied to the area of fuels and specific materials of the nuclear activity. The Analytical Chemistry Department has an atomic emission spectrograph with a source of arc/spark whose focal length is 3.4 meters and a spectral dispersion from 2.5 to 5 A/mm. This equipment was originally equipped with photographic detection. This feature although allowed the simultaneous detection of multiple elements, their response (photographic plate) has been not linear and their data's treatment has been very complex. Two alternatives of digital detection have been examined: CCD2 and CMOS3 according to the progress achieved in the instrumentation that is applied to similar techniques. After exhaustive evaluation an arrangement of 9 linear CCD detectors located in the focal plane originally occupied by 2 x10 inch photographic plates was chosen. The software provided by the manufacturer has been insufficient for cover our analytical necessities due to the requirements of our instrumental application. This led to develop an own program for our applications. Today, our detection system includes an assembly of 7 detectors and an acquisition program with basic control that has been developed in-house. Calibration curves for some chemical elements have shown very promising results, the sensitivity has increased at least 10 times and an important improvement of accuracy of the measurements has also been achieved thanks to our modification. An upgrade with an associated database that will allow obtaining spectra in 3D configuration and extend the instrumental capabilities to second order is being prepared (author)

  20. Role of the outer-edge flame on flame extinction in nitrogen-diluted non-premixed counterflow flames with finite burner diameters

    KAUST Repository

    Chung, Yong Ho; Park, Daegeun; Park, Jeong; Kwon, Oh Boong; Yun, Jin Han; Keel, Sang In

    2013-01-01

    This study of nitrogen-diluted non-premixed counterflow flames with finite burner diameters investigates the important role of the outer-edge flame on flame extinction through experimental and numerical analyses. It explores flame stability diagrams

  1. The effect of CO{sub 2} dissolved in a diesel fuel on the jet flame characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Jin; Huang Zhen; Qiao Xinqi; Hou Yuchun [Shanghai Jiao Tong University, Shanghai (China). Research Institute of Internal Combustion Engine

    2008-03-15

    This paper is concerned with an experimental study of the jet diffusion flame characteristics of fuel containing CO{sub 2}. Using diesel fuel containing dissolved CO{sub 2} gas, experiments were performed under atmospheric conditions with a diesel hole-type nozzle of 0.19 mm orifice diameter at constant injection pressure. In this study, four different CO{sub 2} mass fraction in diesel fuel such as 3.13%, 7.18%, 12.33% and 17.82% were used to study the effect of CO{sub 2} concentration on the jet flame characteristics. Jet flame characteristics were measured by direct photography, meanwhile the image colorimetry is used to assess the qualitative features of jet flame temperature. Experimental results show that the CO{sub 2} gas dilution effect and the atomization effect have a great influence on the flame structure and average temperature. When the injection pressure of diesel fuel increased from 4 MPa to 6 MPa, the low temperature flame length increased from 18.4 cm to 21.7 cm and the full temperature flame length decreased from 147.6 cm to 134.7 cm. With the increase of CO{sub 2} gas dissolved in the diesel fuel, the jet flame full length decreased for the jet atomization being improved greatly meanwhile the low temperature flame length increased for the CO{sub 2} gas dilution effect; with the increase of CO{sub 2} gas dissolved in the diesel fuel, the average temperature of flame increases firstly and then falls. Experimental results validate that higher injection pressure will improve jet atomization and then increased the flame average temperature. 27 refs., 13 figs.

  2. Flame spraying of polymers

    International Nuclear Information System (INIS)

    Varacalle, D.J. Jr.; Zeek, D.P.; Couch, K.W.; Benson, D.M.; Kirk, S.M.

    1997-01-01

    Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs

  3. Physical and Chemical Processes in Turbulent Flames

    Science.gov (United States)

    2015-06-23

    equiangular sectors, defined as the ratio of the actual flame length to the length of a circular-arc of radius equal to the average flame radius. Assuming... flame length ratio obtained directly from the experiments, without any assumption. As explained earlier (Eq. 2.8) the length ratio, (LR=dl(G0)/dl0) is...spherically expanding flames, with the length ratio on the measurement plane, at predefined equiangular sectors, defined as the ratio of the actual flame length to

  4. High-resolution inner-shell spectroscopies of free atoms and molecules using soft-x-ray beamlines at the third-generation synchrotron radiation sources

    International Nuclear Information System (INIS)

    Ueda, Kiyoshi

    2003-01-01

    This article reviews the current status of inner-shell spectroscopies of free atoms and molecules using high-resolution soft-x-ray monochromators installed in the soft-x-ray beamlines at the third-generation synchrotron radiation facilities. Beamlines and endstations devoted to atomic and molecular inner-shell spectroscopies and various types of experimental techniques, such as ion yield spectroscopy, resonant photoemission spectroscopy and multiple-coincidence momentum imaging, are described. Experimental results for K-shell excitation of Ne, O K-shell excitation of H 2 O and CO 2 , C K-shell excitation and ionization of CO 2 and B K-shell excitation of BF 3 , obtained at beamline 27SU of SPring-8 in Japan, are discussed as examples of atomic and molecular inner-shell spectroscopies using the third-generation synchrotron radiation sources. (topical review)

  5. Setup and proof of principle of SAPIS (Stored Atoms Polarized Ion Source), a novel source of polarized H{sup -}/D{sup -} ions; Aufbau und Funktionsnachweis von SAPIS (Stored Atoms Polarized Ion Source), einer neuartigen Quelle polarisierter H{sup -}/D{sup -}-Ionen

    Energy Technology Data Exchange (ETDEWEB)

    Emmerich, R.

    2007-02-14

    The objective of this work was the setup and the proof-of-principle of a new type of negative polarized hydrogen or deuterium ion source, which is based on the charge-exchange reaction (vector)H{sup 0}+Cs{sup 0}{yields}(vector)H{sup -}+Cs{sup +}, as for instance the Colliding-Beams-Source (CBS) at the Cooler Synchrotron COSY in Juelich. In contrast to the CBS, the use of a storage cell for the charge-exchange region promises an increase in H{sup -} current by at least an order of magnitude without considerable polarization losses. For these purposes, a new laboratory was equipped and both a polarized hydrogen/deuterium atomic beam source and an intense neutral cesium-beam source have been build-on. A Lambshift polarimeter, which allows the measurement of the nuclear polarization of the atomic as well as ionic beams, was completed with the construction of a new spin-filter. After commissioning and optimizing each of these sources, a storage cell was developed and installed in the charge-exchange region with a magnetic field. Additionally, components for the extraction, detection and analysis of the negative ion beam were installed. Following the decisive proof of principle, investigation of the properties of the storage cell, especially as to H recombination and depolarisation, was begun. Furthermore, a number of software programs was developed for the control and monitoring of different components of the sources as well as a universal measuring software for the complete installation, including the measurement and calculation of the beam polarization. At the same time, the remote control system of the Cologne source of polarized ions LASCO at the FN tandem accelerator was completely modernized. (orig.)

  6. Determination of trace amounts of selenium in minerals and rocks by flame less atomic-absorption spectrometry; Determinacion de selinio en minerales y rocas por espectrometria de absorcion atomica

    Energy Technology Data Exchange (ETDEWEB)

    Alduan, F. A.; Capdevilla, C.

    1980-07-01

    The determination of trace amounts of selenium In silicate rocks and feldspar by solvent extraction and graphite furnace atomic-absorption spectrometry has been stu- died. Sodium diethyl-ditio carbamate and ammonium pyrrolidine dithiocarbamate have been tried as chelating agents. The best results are achieved when selenium is extracted Into carbon tetrachloride as the sodium diethyldithiocarbamate complex. The method allows to detect 0,75 ppm of selenium in the sample. Recoveries are about 100%. (Author) 7 refs.

  7. Neurotoxicity of brominated flame retardants

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) have been commonly used as commercial flame retardants in a variety of products including plastics and textiles. Despite their decreasing usage worldwide, congeners continue to accumulate in the environment, including soil, dust, food, anima...

  8. Extinction of laminar partially premixed flames

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Suresh K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor Street, Room 2039, MC-251, Chicago, IL 60607-7022 (United States)

    2009-12-15

    Flame extinction represents one of the classical phenomena in combustion science. It is important to a variety of combustion systems in transportation and power generation applications. Flame extinguishment studies are also motivated from the consideration of fire safety and suppression. Such studies have generally considered non-premixed and premixed flames, although fires can often originate in a partially premixed mode, i.e., fuel and oxidizer are partially premixed as they are transported to the reaction zone. Several recent investigations have considered this scenario and focused on the extinction of partially premixed flames (PPFs). Such flames have been described as hybrid flames possessing characteristics of both premixed and non-premixed flames. This paper provides a review of studies dealing with the extinction of PPFs, which represent a broad family of flames, including double, triple (tribrachial), and edge flames. Theoretical, numerical and experimental studies dealing with the extinction of such flames in coflow and counterflow configurations are discussed. Since these flames contain both premixed and non-premixed burning zones, a brief review of the dilution-induced extinction of premixed and non-premixed flames is also provided. For the coflow configuration, processes associated with flame liftoff and blowout are described. Since lifted non-premixed jet flames often contain a partially premixed or an edge-flame structure prior to blowout, the review also considers such flames. While the perspective of this review is broad focusing on the fundamental aspects of flame extinction and blowout, results mostly consider flame extinction caused by the addition of a flame suppressant, with relevance to fire suppression on earth and in space environment. With respect to the latter, the effect of gravity on the extinction of PPFs is discussed. Future research needs are identified. (author)

  9. Initial evaluation and comparison of plasma damage to atomic layer carbon materials using conventional and low T{sub e} plasma sources

    Energy Technology Data Exchange (ETDEWEB)

    Jagtiani, Ashish V.; Miyazoe, Hiroyuki; Chang, Josephine; Farmer, Damon B.; Engel, Michael; Neumayer, Deborah; Han, Shu-Jen; Engelmann, Sebastian U., E-mail: suengelm@us.ibm.com; Joseph, Eric A. [IBM, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Boris, David R.; Hernández, Sandra C.; Walton, Scott G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lock, Evgeniya H. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)

    2016-01-15

    The ability to achieve atomic layer precision is the utmost goal in the implementation of atomic layer etch technology. Carbon-based materials such as carbon nanotubes (CNTs) and graphene are single atomic layers of carbon with unique properties and, as such, represent the ultimate candidates to study the ability to process with atomic layer precision and assess impact of plasma damage to atomic layer materials. In this work, the authors use these materials to evaluate the atomic layer processing capabilities of electron beam generated plasmas. First, the authors evaluate damage to semiconducting CNTs when exposed to beam-generated plasmas and compare these results against the results using typical plasma used in semiconductor processing. The authors find that the beam generated plasma resulted in significantly lower current degradation in comparison to typical plasmas. Next, the authors evaluated the use of electron beam generated plasmas to process graphene-based devices by functionalizing graphene with fluorine, nitrogen, or oxygen to facilitate atomic layer deposition (ALD). The authors found that all adsorbed species resulted in successful ALD with varying impact on the transconductance of the graphene. Furthermore, the authors compare the ability of both beam generated plasma as well as a conventional low ion energy inductively coupled plasma (ICP) to remove silicon nitride (SiN) deposited on top of the graphene films. Our results indicate that, while both systems can remove SiN, an increase in the D/G ratio from 0.08 for unprocessed graphene to 0.22 to 0.26 for the beam generated plasma, while the ICP yielded values from 0.52 to 1.78. Generally, while some plasma-induced damage was seen for both plasma sources, a much wider process window as well as far less damage to CNTs and graphene was observed when using electron beam generated plasmas.

  10. Edge flame instability in low-strain-rate counterflow diffusion flames

    Energy Technology Data Exchange (ETDEWEB)

    Park, June Sung; Hwang, Dong Jin; Park, Jeong; Kim, Jeong Soo; Kim, Sungcho [School of Mechanical and Aerospace Engineering, Sunchon National University, 315 Maegok-dong, Suncheon, Jeonnam 540-742 (Korea, Republic of); Keel, Sang In [Environment & amp; Energy Research Division, Korea Institute of Machinery and Materials, P.O. Box 101, Yusung-gu, Taejon 305-343 (Korea, Republic of); Kim, Tae Kwon [School of Mechanical & amp; Automotive Engineering, Keimyung University, 1000 Sindang-dong, Dalseo-gu, Daegu 704-701 (Korea, Republic of); Noh, Dong Soon [Energy System Research Department, Korea Institute of Energy Research, 71-2 Jang-dong, Yusung-gu, Taejon 305-343 (Korea, Republic of)

    2006-09-15

    Experiments in low-strain-rate methane-air counterflow diffusion flames diluted with nitrogen have been conducted to study flame extinction behavior and edge flame oscillation in which flame length is less than the burner diameter and thus lateral conductive heat loss, in addition to radiative loss, could be high at low global strain rates. The critical mole fraction at flame extinction is examined in terms of velocity ratio and global strain rate. Onset conditions of the edge flame oscillation and the relevant modes are also provided with global strain rate and nitrogen mole fraction in the fuel stream or in terms of fuel Lewis number. It is observed that flame length is intimately relevant to lateral heat loss, and this affects flame extinction and edge flame oscillation considerably. Lateral heat loss causes flame oscillation even at fuel Lewis number less than unity. Edge flame oscillations, which result from the advancing and retreating edge flame motion of the outer flame edge of low-strain-rate flames, are categorized into three modes: a growing, a decaying, and a harmonic-oscillation mode. A flame stability map based on the flame oscillation modes is also provided for low-strain-rate flames. The important contribution of lateral heat loss even to edge flame oscillation is clarified finally. (author)

  11. Design considerations regarding an atomizer for multi-element electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Katskov, Dmitri A., E-mail: katskovda@tut.ac.za [Department of Chemistry, Tshwane University of Technology, Private Bag X680, Pretoria 0001 (South Africa); Sadagov, Yuri M. [All-Russian Scientific Research Institute of Optical and Physical Measurements (VNIIOFI), Ozernaya St. 46, Moscow 119361 (Russian Federation)

    2011-06-15

    determination in Flame AAS with primary line source that is 50-1000 times higher than the limits obtainable with common ETAAS (Electrothermal Atomic Absorption Spectrometry) instrumentation.

  12. Combinación de sistemas de flujo de baja y alta presion para la determinacion de Mg, Ca y Sr en salmueras por espectrofotometria de absorcion atomica con llama Combination of low- and high-pressure flow systems for the determination of Mg, Ca and Sr in brines by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    José Neira

    2001-04-01

    Full Text Available This article describes the combination of low- and high-pressure flow systems for the determination of Magnesium, Calcium and Strontium by flame atomic absorption spectrometry (FAAS. In the low-pressure system a short C-18 RP column (length 0,5 cm was utilized for the preconcentration/matrix separation step, xylenol orange was used as chelating agent and tetrabutylamonium acetate for ion pair formation. The hydraulic high pressure nebulization (HHPN was used for sample transport and sample introduction in the high pressure system. The repeatabilities and detection limits for Mg, Ca and Sr were determined and compared with those obtained by pneumatic nebulization (PN. The results show that the detection limits obtained using the HHPN for Mg, Ca and Sr are between 1.5 to 2 times better than those obtained by PN when the signal transient was measured in area. The system presented a sampling frequency of 130 h-1 for direct determination of Mg, Ca or Sr in samples of saturated sodium chloride used in the production of chlorine and sodium hydroxide.

  13. Determination of high content of copper lead zinc silver in Geo-logical Samples by Flame Atomic Absorption Spectrometry%火焰原子吸收法测定地质样品中高含量的铜铅锌银

    Institute of Scientific and Technical Information of China (English)

    文双辉

    2014-01-01

    This paper deals with the method of non sensitive line determination of high content of copper lead zinc silver in Geological Samples by flame atomic absorption spectrometry, The optimum condi-tions for determination of each component are determined through ex-periment The working curve range 0-125 ug g/ ml,Determination of values and standard values,Component relative standard deviation (n=11) were lower than 1%, suitable for the determination of copper lead zinc silver in the range of 1%-15% samples.%本文研究了采用非灵敏线火焰原子吸收法测定地质样中较高含量的铜铅锌银的方法,通过实验确定了各组分测定的最佳条件。工作曲线范围0-125微克/毫升,测定值与标准值相吻合,各组分相对标准差(n=11)均低于1%,适合地质样品中较高含量铜铅锌银的测定。

  14. Autoignition characteristics of laminar lifted jet flames of pre-vaporized iso-octane in heated coflow air

    KAUST Repository

    Alnoman, Saeed

    2015-12-01

    The stabilization characteristics of laminar non-premixed jet flames of pre-vaporized iso-octane, one of the primary reference fuels for octane rating, have been studied experimentally in heated coflow air. Non-autoignited and autoignited lifted flames were analyzed. With the coflow air at relatively low initial temperatures below 940 K, an external ignition source was required to stabilize the flame. These lifted flames had tribrachial edge structures and their liftoff heights correlated well with the jet velocity scaled by stoichiometric laminar burning velocity, indicating the importance of the edge propagation speed on flame stabilization. At high initial temperatures over 940 K, the autoignited flames were stabilized without requiring an external ignition source. These autoignited lifted flames exhibited either tribrachial edge structures or mild combustion behaviors depending on the level of fuel dilution. Two distinct transition behaviors were observed in the autoignition regime from a nozzle-attached flame to a lifted tribrachial-edge flame and then to lifted mild combustion as the jet velocity increased at a certain fuel dilution level. The liftoff data of the autoignited flames with tribrachial edges were analyzed based on calculated ignition delay times. Analysis of the experimental data suggested that ignition delay time may be much less sensitive to initial temperature under atmospheric pressure conditions as compared with predictions. © 2015 Elsevier Ltd. All rights reserved.

  15. The flame characteristics of the biogas has produced through the digester method with various starters

    Science.gov (United States)

    Ketut, Caturwati Ni; Agung, Sudrajat; Mekro, Permana; Heri, Haryanto; Bachtiar

    2018-01-01

    Increasing the volume of waste, especially in urban areas is a source of problems in realizing the comfort and health of the environment. It needs to do a good handling of garbage so as to provide benefits for the whole community. Organic waste processing through bio-digester method to produce a biogas as an energy source is an effort. This research was conducted to test the characteristics of biogas flame generated from organic waste processing through digester with various of the starter such as: cow dung, goat manure, and leachate that obtained from the landfill at Bagendung-Cilegon. The flame height and maximum temperature of the flame are measured for the same pressure of biogas. The measurements showed the flame produced by bio-digester with leachate starter has the lowest flame height compared to the other types of biogas, and the highest flame height is given by biogas from digester with cow dung as a starter. The maximum flame temperature of biogas produced by leachate as a starter reaches 1027 °C. This value is 7% lower than the maximum flame temperature of biogas produced by cow dung as a starter. Cow dung was observed to be the best starter compared to goat manure and leachate, but the use of leachate as a starter in producing biogas with biodigester method is not the best but it worked.

  16. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Science.gov (United States)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6-4.3%), repeatability (4-9%), reproducibility (9-11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as straightforward

  17. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia, E-mail: e.vasileva-veleva@iaea.org

    2015-01-01

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6–4.3%), repeatability (4–9%), reproducibility (9–11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as

  18. Flame analysis using image processing techniques

    Science.gov (United States)

    Her Jie, Albert Chang; Zamli, Ahmad Faizal Ahmad; Zulazlan Shah Zulkifli, Ahmad; Yee, Joanne Lim Mun; Lim, Mooktzeng

    2018-04-01

    This paper presents image processing techniques with the use of fuzzy logic and neural network approach to perform flame analysis. Flame diagnostic is important in the industry to extract relevant information from flame images. Experiment test is carried out in a model industrial burner with different flow rates. Flame features such as luminous and spectral parameters are extracted using image processing and Fast Fourier Transform (FFT). Flame images are acquired using FLIR infrared camera. Non-linearities such as thermal acoustic oscillations and background noise affect the stability of flame. Flame velocity is one of the important characteristics that determines stability of flame. In this paper, an image processing method is proposed to determine flame velocity. Power spectral density (PSD) graph is a good tool for vibration analysis where flame stability can be approximated. However, a more intelligent diagnostic system is needed to automatically determine flame stability. In this paper, flame features of different flow rates are compared and analyzed. The selected flame features are used as inputs to the proposed fuzzy inference system to determine flame stability. Neural network is used to test the performance of the fuzzy inference system.

  19. Numerical and experimental studies of ethanol flames and autoignition theory for higher alkanes

    Science.gov (United States)

    Saxena, Priyank

    In order to enhance the fuel efficiency of an engine and to control pollutant formation, an improved understanding of the combustion chemistry of the fuels at a fundamental level is paramount. This knowledge can be gained by developing detailed reaction mechanisms of the fuels for various combustion processes and by studying combustion analytically employing reduced-chemistry descriptions. There is a need for small detailed reaction mechanisms for alkane and alcohol fuels with reduced uncertainties in their combustion chemistry that are computationally cheaper in multidimensional CFD calculations. Detailed mechanisms are the starting points in identifying reduced-chemistry descriptions of combustion processes to study problems analytically. This research includes numerical, experimental and analytical studies. The first part of the dissertation consists of numerical and experimental studies of ethanol flames. Although ethanol has gained popularity as a possible low-pollution source of renewable energy, significant uncertainties remain in its combustion chemistry. To begin to address ethanol combustion, first a relatively small detailed reaction mechanism, commonly known as the San Diego Mech, is developed for the combustion of hydrogen, carbon monoxide, formaldehyde, methane, methanol, ethane, ethylene, and acetylene, in air or oxygen-inert mixtures. This mechanism is tested for autoignition, premixed-flame burning velocities, and structures and extinction of diffusion flames and of partially premixed flames of many of these fuels. The reduction in uncertainties in the combustion chemistry can best be achieved by consistently updating a reaction mechanism with reaction rate data for the elementary steps based on newer studies in literature and by testing it against as many experimental conditions as available. The results of such a testing for abovementioned fuels are reported here along with the modifications of reaction-rate parameters of the most important

  20. Stratified turbulent Bunsen flames: flame surface analysis and flame surface density modelling

    Science.gov (United States)

    Ramaekers, W. J. S.; van Oijen, J. A.; de Goey, L. P. H.

    2012-12-01

    In this paper it is investigated whether the Flame Surface Density (FSD) model, developed for turbulent premixed combustion, is also applicable to stratified flames. Direct Numerical Simulations (DNS) of turbulent stratified Bunsen flames have been carried out, using the Flamelet Generated Manifold (FGM) reduction method for reaction kinetics. Before examining the suitability of the FSD model, flame surfaces are characterized in terms of thickness, curvature and stratification. All flames are in the Thin Reaction Zones regime, and the maximum equivalence ratio range covers 0.1⩽φ⩽1.3. For all flames, local flame thicknesses correspond very well to those observed in stretchless, steady premixed flamelets. Extracted curvature radii and mixing length scales are significantly larger than the flame thickness, implying that the stratified flames all burn in a premixed mode. The remaining challenge is accounting for the large variation in (subfilter) mass burning rate. In this contribution, the FSD model is proven to be applicable for Large Eddy Simulations (LES) of stratified flames for the equivalence ratio range 0.1⩽φ⩽1.3. Subfilter mass burning rate variations are taken into account by a subfilter Probability Density Function (PDF) for the mixture fraction, on which the mass burning rate directly depends. A priori analysis point out that for small stratifications (0.4⩽φ⩽1.0), the replacement of the subfilter PDF (obtained from DNS data) by the corresponding Dirac function is appropriate. Integration of the Dirac function with the mass burning rate m=m(φ), can then adequately model the filtered mass burning rate obtained from filtered DNS data. For a larger stratification (0.1⩽φ⩽1.3), and filter widths up to ten flame thicknesses, a β-function for the subfilter PDF yields substantially better predictions than a Dirac function. Finally, inclusion of a simple algebraic model for the FSD resulted only in small additional deviations from DNS data

  1. Technical Note: Effect of explicit M and N-shell atomic transitions on a low-energy x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Peter G. F., E-mail: peter.watson@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal, Quebec H4A 3J1 (Canada)

    2016-04-15

    Purpose: In EGSnrc, atomic transitions to and from the M and N-shells are treated in an average way by default. This approach is justified in which the energy difference between explicit and average M and N-shell binding energies is less than 1 keV, and for most applications can be considered negligible. However, for simulations of low energy x-ray sources on thin, high-Z targets, characteristic x-rays can make up a significant portion of the source spectra. As of release V4-2.4.0, EGSnrc has included an option to enable a more complete algorithm of all atomic transitions available in the EADL compilation. In this paper, the effect of M and N-shell averaging on the calculation of half-value layer (HVL) and relative depth dose (RDD) curve of a 50 kVp intraoperative x-ray tube with a thin gold target was investigated. Methods: A 50 kVp miniature x-ray source with a gold target (The INTRABEAM System, Carl Zeiss, Germany) was modeled with the EGSnrc user code cavity, both with and without M and N-shell averaging. From photon fluence spectra simulations, the source HVLs were determined analytically. The same source model was then used with egs-chamber to calculate RDD curves in water. Results: A 4% increase of HVL was reported when accounting for explicit M and N-shell transitions, and up to a 9% decrease in local relative dose for normalization at 3 mm depth in water. Conclusions: The EGSnrc default of using averaged M and N-shell binding energies has an observable effect on the HVL and RDD of a low energy x-ray source with high-Z target. For accurate modeling of this class of devices, explicit atomic transitions should be included.

  2. Physical Activity as A life style and its Relationship to stress sources for Scientists of the Atomic Energy Authority

    International Nuclear Information System (INIS)

    El Sheakh, A.E.A.

    2014-01-01

    The Atomic Energy Commission of those important and sensitive special nature because of their important role and major in community service and development environment , as it is designed to enable the state to the peaceful use of atomic energy and play the key role in securing the Egyptian environment from the dangers of radioactive contamination , which may result in the activities or nuclear accidents lead to pollution of air, water or soil , or may be issued for nuclear facilities in the surrounding countries of Egypt , and given that we find scientists within the body of scientific personnel with experience distinctive niche so as to be able to do the important role assigned to his performance , which is in the making laboratory experiments and dealing with radioactive materials , including covered by protective measures , and work in the field of activities sterilization of certain products and agricultural crops and medical instruments , and examination of radiation for some industrial materials and food to make sure they are free of radiation and certification so special , the control of nuclear and radiological on any special activities in units of therapy or oil companies or radiology centers and other places that use radioactive sources in its work , holding training courses in the fields of radiation protection and the safe handling of radioactive materials and waste , secure transport of radioactive materials inside throughout the state, working in the field of the development of scientific research various specialized training college students specialized scientific as well as the supervision of theses in different disciplines for graduates of those colleges , and given the importance of their role in the work and life responsibilities entrusted to them , it is natural to be exposed to a lot of psychological pressure. Indicates ''Farouk Abdel Wahab''(1995) to that man has become at present totally dependent on hardware and electronic equipment in all

  3. CFD simulations on marine burner flames

    DEFF Research Database (Denmark)

    Cafaggi, Giovanni; Jensen, Peter Arendt; Glarborg, Peter

    The marine industry is changing with new demands concerning high energy efficiency, fuel flexibility and lower emissions of NOX and SOX. A collaboration between the company Alfa Laval and Technical University of Denmark has been established to support the development of the next generation...... of marine burners. The resulting auxiliary boilers shall be compact and able to operate with different fuel types, while reducing NOX emissions. The specific boiler object of this study uses a swirl stabilized liquid fuel burner, with a pressure swirl spill-return atomizer (Fig.1). The combustion chamber...... is enclosed in a water jacket used for water heating and evaporation, and a convective heat exchanger at the furnace outlet super-heats the steam. The purpose of the present study is to gather detailed knowledge about the influence of fuel spray conditions on marine utility boiler flames. The main goal...

  4. Ultrabright multikilovolt x-ray source: saturated amplification on noble gas transition arrays from hollow atom states

    Science.gov (United States)

    Rhodes, Charles K.; Boyer, Keith

    2004-02-17

    An apparatus and method for the generation of ultrabright multikilovolt x-rays from saturated amplification on noble gas transition arrays from hollow atom states is described. Conditions for x-ray amplification in this spectral region combine the production of cold, high-Z matter, with the direct, selective multiphoton excitation of hollow atoms from clusters using ultraviolet radiation and a nonlinear mode of confined, self-channeled propagation in plasmas. Data obtained is consistent with the presence of saturated amplification on several transition arrays of the hollow atom Xe(L) spectrum (.lambda..about.2.9 .ANG.). An estimate of the peak brightness achieved is .about.10.sup.29 .gamma..multidot.s.sup.-1.multidot.mm.sup.-2.multidot.mr.sup.-2 (0.1% Bandwidth).sup.-1, that is .about.10.sup.5 -fold higher than presently available synchotron technology.

  5. Resonance absorption measurements of atom concentrations in reacting gas mixtures. II. Calibration of microwave sources over a wide temperature range

    International Nuclear Information System (INIS)

    Chiang, C.; Lifshitz, A.; Skinner, G.B.; Wood, D.R.

    1979-01-01

    A series of experiments was carried out to calibrate three different microwave discharge lamps for analysis for D or H atoms, using Lyman-α absorption. Known concentrations of D atoms were produced in a shock tube by the reaction of 0.05--4 ppm D 2 with N 2 O in argon at 1800--3000 K. H atoms were produced by dissociation of 2,2,3,3-tetramethylbutane (10 ppm in argon) at 980--1140 K. These absorption data were compared with the absorption calculated from Lyman-α line shapes reported in an earlier paper, good agreement being found. These experiments provide a sound basis for obtaining the temperature and concentration dependence of the absorption coefficient over a wide temperature range, for H and D concentrations between 10 -12 and 10 -10 mole/cc

  6. Bismuth as a general internal standard for lead in atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Bechlin, Marcos A.; Fortunato, Felipe M.; Ferreira, Edilene C.; Neto, José A. Gomes; Nóbrega, Joaquim A.; Donati, George L.; Jones, Bradley T.

    2014-01-01

    Highlights: • Single internal standard is commonly proposed for definite application in AAS. • Internal standard for general use in AAS techniques is original. • Bi showed efficiency as internal standard for Pb determinations by FAAS and GFAAS. • Assorted samples were analyzed and accurate results were found. - Abstract: Bismuth was evaluated as internal standard for Pb determination by line source flame atomic absorption spectrometry (LS FAAS), high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) and line source graphite furnace atomic absorption spectrometry (LS GFAAS). Analysis of samples containing different matrices indicated close relationship between Pb and Bi absorbances. Correlation coefficients of calibration curves built up by plotting A Pb /A Bi versus Pb concentration were higher than 0.9953 (FAAS) and higher than 0.9993 (GFAAS). Recoveries of Pb improved from 52–118% (without IS) to 97–109% (IS, LS FAAS); 74–231% (without IS) to 96–109% (IS, HR-CS FAAS); and 36–125% (without IS) to 96–110% (IS, LS GFAAS). The relative standard deviations (n = 12) were reduced from 0.6–9.2% (without IS) to 0.3–4.3% (IS, LS FAAS); 0.7–7.7% (without IS) to 0.1–4.0% (IS, HR-CS FAAS); and 2.1–13% (without IS) to 0.4–5.9% (IS, LS GFAAS)

  7. Bismuth as a general internal standard for lead in atomic absorption spectrometry.

    Science.gov (United States)

    Bechlin, Marcos A; Fortunato, Felipe M; Ferreira, Edilene C; Gomes Neto, José A; Nóbrega, Joaquim A; Donati, George L; Jones, Bradley T

    2014-06-11

    Bismuth was evaluated as internal standard for Pb determination by line source flame atomic absorption spectrometry (LS FAAS), high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) and line source graphite furnace atomic absorption spectrometry (LS GFAAS). Analysis of samples containing different matrices indicated close relationship between Pb and Bi absorbances. Correlation coefficients of calibration curves built up by plotting A(Pb)/A(Bi)versus Pb concentration were higher than 0.9953 (FAAS) and higher than 0.9993 (GFAAS). Recoveries of Pb improved from 52-118% (without IS) to 97-109% (IS, LS FAAS); 74-231% (without IS) to 96-109% (IS, HR-CS FAAS); and 36-125% (without IS) to 96-110% (IS, LS GFAAS). The relative standard deviations (n=12) were reduced from 0.6-9.2% (without IS) to 0.3-4.3% (IS, LS FAAS); 0.7-7.7% (without IS) to 0.1-4.0% (IS, HR-CS FAAS); and 2.1-13% (without IS) to 0.4-5.9% (IS, LS GFAAS). Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Spatial and radiative properties of an open-flame hydrogen plume

    Energy Technology Data Exchange (ETDEWEB)

    Schefer, R.W.; Houf, W.G. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States); Bourne, B.; Colton, J. [SRI International, 333 Ravenwood Ave., Menlo Park, CA 94025 (United States)

    2006-08-15

    Considerable effort is being directed toward updating safety codes and standards in preparation for production, distribution, and retail of hydrogen as a consumer energy source. In the present study, measurements were performed in large-scale, vertical flames to characterize the dimensional and radiative properties of an ignited hydrogen jet. These data are relevant to the safety scenario of a sudden leak in a high-pressure hydrogen containment vessel. Specifically, the data will provide a technological basis for determining hazardous length scales associated with unintended releases at hydrogen storage and distribution centers. Visible and infrared video and ultraviolet flame luminescence imaging were used to evaluate flame length, diameter and structure. Radiometer measurements allowed determination of the radiant heat flux from the flame. The results show that flame length increases with total jet mass flow rate and jet nozzle diameter. When plotted as a function of Froude number, which measures the relative importance of jet momentum and buoyancy, the measured flame lengths for a range of operating conditions collapse onto the same curve. Good comparison with hydrocarbon jet flame lengths is found, demonstrating that the non-dimensional correlations are valid for a variety of fuel types. The radiative heat flux measurements for hydrogen flames show good agreement with non-dimensional correlations and scaling laws developed for a range of fuels and flame conditions. This result verifies that such correlations can be used to predict radiative heat flux from a wide variety of hydrogen flames and establishes a basis for predicting a priori the characteristics of flames resulting from accidental releases. (author)

  9. Research on flame retardation of wool fibers

    International Nuclear Information System (INIS)

    Enomoto, Ichiro; Ametani, Kazuo; Sawai, Takeshi

    1990-01-01

    Flame retardant, vinyl phosphonate oligomer, was uniformly impregnated in wool fibers, and by irradiating low energy electron beam or cobalt-60 gamma ray, the flame retardation of fabrics was attempted, as the results, the following knowledges were obtained. At the rate of sticking of flame retardant lower than that in cotton fabrics, sufficient flame retarding property can be given. The flame retarding property withstands 30 times of washing. The lowering of strength due to the processing hardly arose. For the flame retardation, gamma-ray was more effective than electron beam. Since the accidents of burning clothes have occurred frequently, their flame retardation has been demanded. So far the flame retardation of cotton fabrics has been advanced, but this time the research on the flame retardation of wool fabrics was carried out by the same method. The experimental method is explained. As for the performance of the processed fabrics, the rate of sticking of the flame retardant, the efficiency of utilization, the flame retarding property, the endurance in washing and the tensile and tearing strength were examined. As the oxygen index was higher, the flame retarding property was higher, and in the case of the index being more than 27, the flame retarding property is sufficient, that is, the rate of sticking of 6% in serge and 5% in muslin. (K.I.)

  10. Atomic interferometry

    International Nuclear Information System (INIS)

    Baudon, J.; Robert, J.

    2004-01-01

    Since the theoretical works of L. De Broglie (1924) and the famous experiment of Davisson and Germer (1927), we know that a wave is linked with any particle of mass m by the relation λ = h/(mv), where λ is the wavelength, v the particle velocity and h is the Planck constant. The basic principle of the interferometry of any material particle, atom, molecule or aggregate is simple: using a simple incident wave, several mutually consistent waves (with well-defined relative phases) are generated and controllable phase-shifts are introduced between them in order to generate a wave which is the sum of the previous waves. An interference figure is obtained which consists in a succession of dark and bright fringes. The atomic interferometry is based on the same principle but involves different techniques, different wave equations, but also different beams, sources and correlations which are described in this book. Because of the small possible wavelengths and the wide range of possible atomic interactions, atomic interferometers can be used in many domains from the sub-micron lithography to the construction of sensors like: inertial sensors, gravity-meters, accelerometers, gyro-meters etc. The first chapter is a preliminary study of the space and time diffraction of atoms. The next chapters is devoted to the description of slit, light separation and polarization interferometers, and the last chapter treats of the properties of Bose-Einstein condensates which are interesting in atomic interferometry. (J.S.)

  11. Flame visualization in power stations

    Energy Technology Data Exchange (ETDEWEB)

    Hulshof, H J.M.; Thus, A W; Verhage, A J.L. [KEMA Fossil Generation, Arnhem (Netherlands)

    1994-01-01

    The study on the title subject is aimed at the determination of the form of the flame and the radiation temperature of the flames of the burners in electric power plants. The adjustment of the burners in a boiler is assessed on the basis of the total performance, in which the NO[sub x]- and CO-concentrations in the flue gases are normative. By comparing the burners mutually, deviating adjustments can be observed, applying optical monitoring techniques. Measurements have been carried out of the coal flames in the unit Gelderland13 of the Dutch energy production company EPON and of the gas flames at the Claus plant A and B of the Dutch energy company EPZ. The final aim of the title study is to draft guidelines, based on the measured flame data, by means of which for every individual burner the adjustment of the fuel supply, the relation with the air supply and the swirl of the combustion air can be optimized

  12. Role of the outer-edge flame on flame extinction in nitrogen-diluted non-premixed counterflow flames with finite burner diameters

    KAUST Repository

    Chung, Yong Ho

    2013-03-01

    This study of nitrogen-diluted non-premixed counterflow flames with finite burner diameters investigates the important role of the outer-edge flame on flame extinction through experimental and numerical analyses. It explores flame stability diagrams mapping the flame extinction response of nitrogen-diluted non-premixed counterflow flames to varying global strain rates in terms of burner diameter, burner gap, and velocity ratio. A critical nitrogen mole fraction exists beyond which the flame cannot be sustained; the critical nitrogen mole fraction versus global strain rate curves have C-shapes for various burner diameters, burner gaps, and velocity ratios. At sufficiently high strain-rate flames, these curves collapse into one curve; therefore, the flames follow the one-dimensional flame response of a typical diffusion flame. Low strain-rate flames are significantly affected by radial conductive heat loss, and therefore flame length. Three flame extinction modes are identified: flame extinction through shrinkage of the outer-edge flame with or without oscillations at the outer-edge flame prior to the extinction, and flame extinction through a flame hole at the flame center. The extinction modes are significantly affected by the behavior of the outer-edge flame. Detailed explanations are provided based on the measured flame-surface temperature and numerical evaluation of the fractional contribution of each term in the energy equation. Radial conductive heat loss at the flame edge to ambience is the main mechanism of extinction through shrinkage of the outer-edge flame in low strain-rate flames. Reduction of the burner diameter can extend the flame extinction mode by shrinking the outer-edge flame in higher strain-rate flames. © 2012 Elsevier Ltd. All rights reserved.

  13. Flame Retardants Used in Flexible Polyurethane Foam

    Science.gov (United States)

    The partnership project on flame retardants in furniture seeks to update the health and environmental profiles of flame-retardant chemicals that meet fire safety standards for upholstered consumer products with polyurethane foam

  14. Experiment and Simulation of Autoignition in Jet Flames and its Relevance to Flame Stabilization and Structure

    KAUST Repository

    Al-Noman, Saeed M.

    2016-01-01

    temperature coflow air were studied numerically. Several flame configurations were investigated by varying the initial temperature and fuel mole fraction. Characteristics of chemical kinetics structures for autoignited lifted flames were discussed based on the kinetic structures of homogeneous autoignition and flame propagation of premixed mixtures. Results showed that for autoignited lifted flame with tribrachial structure, a transition from autoignition to flame propagation modes occurs for reasonably stoichiometric mixtures. Characteristics of Mild combustion can be treated as an autoignited lean premixed lifted flame. Transition behavior from Mild combustion to a nozzle-attached flame was also investigated by increasing the fuel mole fraction.

  15. 30 CFR 14.20 - Flame resistance.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flame resistance. 14.20 Section 14.20 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF... § 14.20 Flame resistance. Conveyor belts for use in underground coal mines must be flame-resistant and...

  16. TURBULENT OXYGEN FLAMES IN TYPE Ia SUPERNOVAE

    International Nuclear Information System (INIS)

    Aspden, A. J.; Bell, J. B.; Woosley, S. E.

    2011-01-01

    In previous studies, we examined turbulence-flame interactions in carbon-burning thermonuclear flames in Type Ia supernovae. In this study, we consider turbulence-flame interactions in the trailing oxygen flames. The two aims of the paper are to examine the response of the inductive oxygen flame to intense levels of turbulence, and to explore the possibility of transition to detonation in the oxygen flame. Scaling arguments analogous to the carbon flames are presented and then compared against three-dimensional simulations for a range of Damkoehler numbers (Da 16 ) at a fixed Karlovitz number. The simulations suggest that turbulence does not significantly affect the oxygen flame when Da 16 16 >1, turbulence enhances heat transfer and drives the propagation of a flame that is narrower than the corresponding inductive flame would be. Furthermore, burning under these conditions appears to occur as part of a combined carbon-oxygen turbulent flame with complex compound structure. The simulations do not appear to support the possibility of a transition to detonation in the oxygen flame, but do not preclude it either.

  17. Hysteresis and transition in swirling nonpremixed flames

    NARCIS (Netherlands)

    Tummers, M.J.; Hübner, A.W.; van Veen, E.H.; Hanjalic, K.; van der Meer, Theodorus H.

    2009-01-01

    Strongly swirling nonpremixed flames are known to exhibit a hysteresis when transiting from an attached long, sooty, yellow flame to a short lifted blue flame, and vice versa. The upward transition (by increasing the air and fuel flow rates) corresponds to a vortex breakdown, i.e. an abrupt change

  18. History-Based Instruction Enriched with Various Sources of Situational Interest on the Topic of the Atom: the Effect on Students' Achievement and Interest

    Science.gov (United States)

    Pekdağ, Bülent; Azizoğlu, Nursen

    2018-05-01

    This study examines the effect of history-based instruction on the topic of the atom on students' academic achievement and their interest in the history of science, investigating as well the relationship between student interest and academic achievement. The sample of the study consisted of two groups of freshman students from an undergraduate elementary science teachers program. The same chemistry instructor taught the groups, which were randomly assigned as an experimental and a control group. The students in the control group received traditional teacher-centered instruction, while the experimental group students were taught the topic of the atom using history-based instruction enriched with various sources of situational interest such as novelty, autonomy, social involvement, and knowledge acquisition (NASK). Data gathering instruments were the Atom Achievement Test and the History of Science Interest Scale, administered to both of the groups before and after the instruction. The data were analyzed with the independent-samples t test, the paired-samples t test, and one-way ANCOVA statistical analysis. The results showed that the history-based instruction including NASK was more effective than traditional instruction in improving the students' learning of the subject of the atom as well as in stimulating and improving students' interest in the history of science. Further, students with high interest displayed significantly better achievement than students with low interest. The better learning of the topic of the atom was more pronounced in the case of students with a high interest in the history of science compared to students with moderate or low interest.

  19. In Situ Measurements of Sulfur Hexafluoride (SF6) and age of air from NH sources during the Atmospheric Tomography (ATom) global airborne survey

    Science.gov (United States)

    Elkins, J. W.; Moore, F. L.; Hintsa, E. J.; Ray, E. A.; Dutton, G. S.; Nance, J. D.; Hall, B. D.; Dlugokencky, E. J.; Sweeney, C.; Montzka, S. A.; Newman, P. A.

    2017-12-01

    Atmospheric SF6 is an excellent tracer of atmospheric transport in the troposphere, because of its long lifetime (850 years), mostly northern hemispheric (NH) emissions (95%), and high atmospheric growth rate ( 4%/yr.). The gas is used in the distribution of electrical power, because it is an excellent insulator. It is primarily released through its use (leaking and refilling) in high voltage power transformers. Two NOAA/GMD airborne, in situ gas chromatographs (GCs), PAN and other Trace Hydrohalocarbons ExpeRiment (PANTHER) and UAS Chromatograph for Atmospheric Trace Species (UCATS), operated on the first two circuits of the Atmospheric Tomography Mission (ATom-1 & ATom-2). Both instruments measure nitrous oxide (N2O) and sulfur hexafluoride (SF6) once every 70 seconds using a very sensitive electron capture detector (ECD). We combined both measurements into one data set for analysis of twice the amount of data, since both instruments are comparable and used the same gas standards. The main purpose of ATom is to study the influence of air quality on climate during the four seasons, where two seasons are completed so far. The altitude-latitude cross sections of SF6 mixing ratios during the ATom-1 (left) shows sources are mostly located in the NH ( 95%). The upper troposphere shows inter-hemispheric mixing. The polar stratosphere shows older air that is mixed with air from the mesospheric sink. Using the procedure described by Waugh et al., (2013) [JGR-Atmos. 10.1002/jgrd.50189] and a recent growth rate of 0.32 ppt yr-1, we have calculated the mean age of each SF6 measurement from its source at ground level in the NH (lat. range of 30-50°N). The contours of age (right) are in agreement with the mean inter-hemispheric exchange time (τNS) of 1.2 yr and higher ages in the polar stratosphere (2.5-3.0 yr).

  20. Experimental characterization of methane inverse diffusion flame

    KAUST Repository

    Elbaz, Ayman M.

    2014-06-26

    This article presents 10-kHz images of OH-PLIF simultaneously with 2-D PIV measurements in an inverse methane diffusion flame. Under a constant fuel flow rate, the central air jet Re was varied, leading to air to fuel velocity ratio, Vr, to vary from 8.3 to 66.5. Starting from Vr = 20.7, the flame is commonly characterized by three distinct zones. The length of the lower fuel entrainment region is inversely proportional to Vr. The flames investigated resemble a string shear layer confining this zone, and converging into the second distinct region, the flame neck zone. The third region is the rest of the flame, which spreads in a jet-like manner. The inverse diffusion flames exhibit varying degrees of partial premixing, depending upon on the velocity ratio Vr, and this region of partial premixing evolves into a well-mixed reaction zone along the flame centerline. The OH distribution correlated with the changes in the mean characteristics of the flow through reduction in the local Reynolds number due to heat release. The existence of a flame suppresses or laminarizes the turbulence at early axial locations and promotes fluctuations at the flame tip for flames with Vr < 49.8. In addition, the flame jet width can be correlated to the OH distribution. In upstream regions of the flames, the breaks in OH are counterbalanced by flame closures and are governed by edge flame propagation. These local extinctions were found to occur at locations where large flow structures were impinging on the flame and are associated with a locally higher strain rate or correlated to the local high strain rates at the flame hole edges without this flow impinging. Another contributor to re-ignition was found to be growing flame kernels. As the flames approach global blow-off, these kernels become the main mechanism for re-ignition further downstream of the flames. At low Vr, laminarization within the early regions of the flame provides an effective shield, preventing the jet flow from

  1. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide

    International Nuclear Information System (INIS)

    Pourjavid, Mohammad Reza; Sehat, Ali Akbari; Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad

    2014-01-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L −1 for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31–355 μg L −1 for Mn(II) and 0.34–380 μg L −1 for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. - Highlights: • We use synthesized graphene oxide as adsorbent for SPE of Mn(II) and Fe(III) ions. • Adsorption mechanism was investigated by PM6 semi-empirical potential energy surface. • Detection limits were 145 and 162 ng L −1 for Mn and Fe, respectively. • The preconcentration factor was 325 and sample flow rate is 8 mL min −1 . • It was successfully applied to the determination of Mn and Fe ions in real samples

  2. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavid, Mohammad Reza, E-mail: pourjavid@gmail.com [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of); Sehat, Ali Akbari [Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L{sup −1} for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31–355 μg L{sup −1} for Mn(II) and 0.34–380 μg L{sup −1} for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. - Highlights: • We use synthesized graphene oxide as adsorbent for SPE of Mn(II) and Fe(III) ions. • Adsorption mechanism was investigated by PM6 semi-empirical potential energy surface. • Detection limits were 145 and 162 ng L{sup −1} for Mn and Fe, respectively. • The preconcentration factor was 325 and sample flow rate is 8 mL min{sup −1}. • It was successfully applied to the determination of Mn and Fe ions in real samples.

  3. Atomic politics

    International Nuclear Information System (INIS)

    Skogmar, G.

    1979-01-01

    The authors basic point is that the military and civil sides of atomic energy cannot be separated. The general aim of the book is to analyze both the military and civil branches, and the interdependence between them, of American foreign policy in the atomic field. Atomic policy is seen as one of the most important imstruments of foreign policy which, in turn, is seen against the background of American imperialism in general. Firstly, the book investigates the most important means by which the United States has controlled the development in the nuclear field in other countries. These means include influencing the conditions of access to nuclear resources of various kinds, influencing the flow of technical-economic information and influencing international organizations and treaties bearing on atomic energy. The time period treated is 1945-1973. 1973 is chosen as the end-year of the study mainly because of the new conditions in the whole energy field initiated by the oil crisis in that year. The sources of the empirical work are mainly hearings before the Joint Committee on Atomic Energy of the U.S. Congress and legal material of various kinds. Secondly, the goals of the American policy are analyzed. The goals identified are armament effect, non-proliferation (horizontal), sales, and energy dependence. The relation between the main goals is discussed.The discussion is centered on the interdependence between the military and the civil aspects, conflict and coincidence of various goals, the relation between short-term and long-term goals, and the possibilities of using one goal as pretext for another. Thirdly, some causes of the changes in the atomic policy around 1953 and 1963 are identified. These are the strategic balance, the competitive situation, the capacity (of the American atomic productive apparatus), and the nuclear technological stage. The specific composition of these four factors at the two time-points can explain the changes of policy. (author)

  4. Utilization of ion source 'SUPERSHYPIE' in the study of low energy ion-atom and ion-molecule collisions

    International Nuclear Information System (INIS)

    Bazin, V.; Boduch, P.; Chesnel, J.Y.; Fremont, F.; Lecler, D.; Pacquet, J. Y.; Gaubert, G.; Leroy, R.

    1999-01-01

    Modifications in the ECR 4M ion source are described, which conducted to realization of the advanced source 'SUPERSHYPIE'. The Ar 8+ ion collision with Cs(6s,6p) were studied by photon spectroscopy at low energy, where the process is dominated by simple electron capture. Results obtained with 'SUPERSHYPIE' source are presented. The source was utilized also in ion-molecule collisions (CO, H 2 ) to study the spectra of recoil ions and Auger electron spectra in the Ar 17+ He collisions. The excellent performances of 'SUPERSHYPIE' in high charge production and concerning its accurate and fine control and stability are illustrated and underlined as compared with those of ECR 4M source

  5. Large-eddy simulation of a bluff-body stabilised turbulent premixed flame using the transported flame surface density approach

    Science.gov (United States)

    Lee, Chin Yik; Cant, Stewart

    2017-07-01

    A premixed propane-air flame stabilised on a triangular bluff body in a model jet-engine afterburner configuration is investigated using large-eddy simulation (LES). The reaction rate source term for turbulent premixed combustion is closed using the transported flame surface density (TFSD) model. In this approach, there is no need to assume local equilibrium between the generation and destruction of subgrid FSD, as commonly done in simple algebraic closure models. Instead, the key processes that create and destroy FSD are accounted for explicitly. This allows the model to capture large-scale unsteady flame propagation in the presence of combustion instabilities, or in situations where the flame encounters progressive wrinkling with time. In this study, comprehensive validation of the numerical method is carried out. For the non-reacting flow, good agreement for both the time-averaged and root-mean-square velocity fields are obtained, and the Karman type vortex shedding behaviour seen in the experiment is well represented. For the reacting flow, two mesh configurations are used to investigate the sensitivity of the LES results to the numerical resolution. Profiles for the velocity and temperature fields exhibit good agreement with the experimental data for both the coarse and dense mesh. This demonstrates the capability of LES coupled with the TFSD approach in representing the highly unsteady premixed combustion observed in this configuration. The instantaneous flow pattern and turbulent flame behaviour are discussed, and the differences between the non-reacting and reacting flow are described through visualisation of vortical structures and their interaction with the flame. Lastly, the generation and destruction of FSD are evaluated by examining the individual terms in the FSD transport equation. Localised regions where straining, curvature and propagation are each dominant are observed, highlighting the importance of non-equilibrium effects of FSD generation and

  6. X-ray laser implementation by means of a strong source of high-spin metastable atoms

    International Nuclear Information System (INIS)

    Helman, J.S.; Rau, C.; Bunge, C.F.

    1983-01-01

    High-spin metastable atomic beams of high density and extremely small divergence can be produced by electron capture during grazing-angle scattering of ion beams at ferromagnetic surfaces. This can be used to generate a long-lived reservoir of Li 1s2s2p 4 P/sub 5/2//sup ts0/ with enough density of metastables so that after laser-induced transfer to Li 1s2p/sup ts2/P strong lasing at 207 A should occur. This novel technique can also be used to produce a variety of other metastables known as potential candidates for lasing at shorter wavelengths

  7. The VLT FLAMES Tarantula Survey

    NARCIS (Netherlands)

    Evans, C.; Taylor, W.; Sana, H.; Hénault-Brunet, V.; Bagnoli, T.; Bastian, N.; Bestenlehner, J.; Bonanos, A.; Bressert, E.; Brott, I.; Campbell, M.; Cantiello, M.; Carraro, G.; Clark, S.; Costa, E.; Crowther, P.; de Koter, A.; de Mink, S.; Doran, E.; Dufton, P.; Dunstall, P.; Garcia, M.; Gieles, M.; Gräfener, G.; Herrero, A.; Howarth, I.; Izzard, R.; Köhler, K.; Langer, N.; Lennon, D.; Maíz Apellániz, J.; Markova, N.; Najarro, P.; Puls, J.; Ramirez, O.; Sabín-Sanjulián, C.; Simón-Díaz, S.; Smartt, S.; Stroud, V.; van Loon, J.; Vink, J.S.; Walborn, N.

    2011-01-01

    We introduce the VLT FLAMES Tarantula Survey, an ESO Large Programme from which we have obtained optical spectroscopy of over 800 massive stars in the spectacular 30 Doradus region of the Large Magellanic Cloud. A key feature is the use of multi-epoch observations to provide strong constraints on

  8. Micro-sampling method based on high-resolution continuum source graphite furnace atomic absorption spectrometry for calcium determination in blood and mitochondrial suspensions.

    Science.gov (United States)

    Gómez-Nieto, Beatriz; Gismera, Mª Jesús; Sevilla, Mª Teresa; Satrústegui, Jorgina; Procopio, Jesús R

    2017-08-01

    A micro-sampling and straightforward method based on high resolution continuum source atomic absorption spectrometry (HR-CS AAS) was developed to determine extracellular and intracellular Ca in samples of interest in clinical and biomedical analysis. Solid sampling platforms were used to introduce the micro-samples into the graphite furnace atomizer. The secondary absorption line for Ca, located at 239.856nm, was selected to carry out the measurements. Experimental parameters such as pyrolysis and atomization temperatures and the amount of sample introduced for the measurements were optimized. Calibration was performed using aqueous standards and the approach to measure at the wings of the absorption lines was employed for the expansion of the linear response range. The limit of detection was of 0.02mgL -1 Ca (0.39ng Ca) and the upper limit of linear range was increased up to 8.0mgL -1 Ca (160ng Ca). The proposed method was used to determine Ca in mitochondrial suspensions and whole blood samples with successful results. Adequate recoveries (within 91-107%) were obtained in the tests performed for validation purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Flex-flame burner and combustion method

    Science.gov (United States)

    Soupos, Vasilios; Zelepouga, Serguei; Rue, David M.; Abbasi, Hamid A.

    2010-08-24

    A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

  10. Simulation of flame surface density and burning rate of a premixed turbulent flame using contour advection

    Energy Technology Data Exchange (ETDEWEB)

    Tang, B.H.Y.; Chan, C.K. [Department of Applied Mathematics, The Hong Kong Polytechnic University, Hung Hom, Kowloon (Hong Kong)

    2006-10-15

    In this paper, a 2-dimensional rod-stabilized V-shaped flame is simulated using contour advection with surgery as well as the random vortex method. Effects of turbulence on various quantities, such as flame brush thickness and flame surface density, are investigated. The flame surface density S is estimated using the Bray-Moss-Libby formulation, which involves the use of a mean orientation factor {sigma}{sub c}. As a comparison, values of S are also obtained using Shepherd's model, which employs the values of mean flame surface area and mean flame length. Local flame structure is characterized in terms of turbulent flame brush, orientation factor, and flame surface density. Profiles of S obtained using the two different models are compared and show that discrepancy is more evident with increasing turbulence intensity. (author)

  11. 911 Call Center (PSAP) Service Areas, Master coverage of "atom" features used as a source to generate several derivative layers for the Sheriff RMS and E-911 map rolls. Cover is painstakingly maintained interactively by GIS staff. All atom boundaries are snapped to the road centerline cover, Published in 2008, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — 911 Call Center (PSAP) Service Areas dataset current as of 2008. Master coverage of "atom" features used as a source to generate several derivative layers for the...

  12. Analysis of x-ray spectra emitted from highly ionized atoms in the vacuum spark and laser-produced high power plasma sources

    International Nuclear Information System (INIS)

    Mandelbaum, P.

    1987-05-01

    The interest in atomic spectroscopy has greatly been reinforced in the last ten years. This gain of interest is directly related to the developments in different fields of research where hot plasmas are created. These fields include in particular controlled thermonuclear fusion research by means of inertial or magnetic confinement approaches and also the most recent efforts to achieve lasers in the XUV region. The present work is based on the specific contribution of the atomic spectroscopy group at the Hebrew University. The recent development of both theoretical and experimental tools allowed us to progress in the understanding of the highly ionized states of heavy elements. In this work the low-inductance vacuum-spark developed at the Hebrew University was used as the hot plasma source. The spectra were recorded in the 7-300 A range by means of a high-resolution extreme-grazing-incidence spectrometer developed at the Racah Institute by Profs. J.L. Schwob and B.S. Fraenkel. To the extend the spectroscopic studies to higher-Z atoms, the laser-produced plasma facility at Soreq Nuclear Center was used. In this work the spectra of the sixth row elements were recorded in the x-rays by means of a crystal spectrometer. All these experimental systems are briefly described in chapter one. Chapter two deals with the theoretical methods used in the present work for the atomic calculations. Chapter three deals with the spectra of elements of the fifth row emitted from the vacuum-spark in the 30-150 A range. These spectra as experimental data were used in order to test ab-initio computations along the NiI sequence 3d-nl transitions. The results of this work are presented in chapter four. Chapter five is devoted to the measurement and analysis of spectra emitted from the vacuum-spark by rare-earth elements. (author)

  13. A flame particle tracking analysis of turbulence–chemistry interaction in hydrogen–air premixed flames

    KAUST Repository

    Uranakara, Harshavardhana A.; Chaudhuri, Swetaprovo; Dave, Himanshu L.; Arias, Paul G.; Im, Hong G.

    2015-01-01

    Interactions of turbulence, molecular transport, and energy transport, coupled with chemistry play a crucial role in the evolution of flame surface geometry, propagation, annihilation, and local extinction/re-ignition characteristics of intensely turbulent premixed flames. This study seeks to understand how these interactions affect flame surface annihilation of lean hydrogen–air premixed turbulent flames. Direct numerical simulations (DNSs) are conducted at different parametric conditions with a detailed reaction mechanism and transport properties for hydrogen–air flames. Flame particle tracking (FPT) technique is used to follow specific flame surface segments. An analytical expression for the local displacement flame speed (Sd) of a temperature isosurface is considered, and the contributions of transport, chemistry, and kinematics on the displacement flame speed at different turbulence-flame interaction conditions are identified. In general, the displacement flame speed for the flame particles is found to increase with time for all conditions considered. This is because, eventually all flame surfaces and their resident flame particles approach annihilation by reactant island formation at the end of stretching and folding processes induced by turbulence. Statistics of principal curvature evolving in time, obtained using FPT, suggest that these islands are ellipsoidal on average enclosing fresh reactants. Further examinations show that the increase in Sd is caused by the increased negative curvature of the flame surface and eventual homogenization of temperature gradients as these reactant islands shrink due to flame propagation and turbulent mixing. Finally, the evolution of the normalized, averaged, displacement flame speed vs. stretch Karlovitz number are found to collapse on a narrow band, suggesting that a unified description of flame speed dependence on stretch rate may be possible in the Lagrangian description.

  14. A flame particle tracking analysis of turbulence–chemistry interaction in hydrogen–air premixed flames

    KAUST Repository

    Uranakara, Harshavardhana A.

    2015-11-21

    Interactions of turbulence, molecular transport, and energy transport, coupled with chemistry play a crucial role in the evolution of flame surface geometry, propagation, annihilation, and local extinction/re-ignition characteristics of intensely turbulent premixed flames. This study seeks to understand how these interactions affect flame surface annihilation of lean hydrogen–air premixed turbulent flames. Direct numerical simulations (DNSs) are conducted at different parametric conditions with a detailed reaction mechanism and transport properties for hydrogen–air flames. Flame particle tracking (FPT) technique is used to follow specific flame surface segments. An analytical expression for the local displacement flame speed (Sd) of a temperature isosurface is considered, and the contributions of transport, chemistry, and kinematics on the displace