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Sample records for atomic absorption technique

  1. Coprecipitation Technique for Preconcentration of Some Metal Ions prior to Graphite Furnace Atomic Absorption Spectrometric Determination

    OpenAIRE

    上田, 穣一

    1998-01-01

    Summary-for the preconcentration of trace ions in the graphite furnace atomic absorption spectrometric determination (GFAAS), a rapid and simple coprecipitation method which does not need the filtration

  2. Zeeman atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hadeishi, T.; McLaughlin, R.

    1978-08-01

    The design and development of a Zeeman atomic absorption spectrometer for trace element analysis are described. An instruction manual is included which details the operation, adjustment, and maintenance. Specifications and circuit diagrams are given. (WHK)

  3. Atomic absorption techniques for determining vanadium and nickel in crude oil

    Energy Technology Data Exchange (ETDEWEB)

    Grizzle, P.L.; Wilson, C.A.; Ferrero, E.P.; Coleman, H.J.

    1977-05-01

    Four different techniques for sample preparation were evaluated for determining vanadium and nickel in crude oils by atomic absorption (AA) spectroscopy: (1) The flame-analyzed dilution method which consists of direct-flame AA analysis after diluting the sample with a suitable organic solvent; (2) the flame-analyzed, wet-ashing method in which the sample is combusted and the residue is then dissolved before flame analysis; (3) the flameless, dilution method which involves flameless AA analysis of the sample following dilution with a suitable organic solvent; and (4) the direct, flameless method in which the crude oil or residue is directly analyzed by flameless AA. The flame-analyzed dilution method yielded erratic and inaccurate analytical results for samples of crude oils as well as for a residual sample containing standard amounts of vanadium and nickel; hence, it is unsatisfactory for oil-identification. Similarly, the direct, flameless method is unsatisfactory owing to the small concentration range available for analysis (less than approximately 15 ppM). Both the flame-analyzed, wet-ashing and flameless-dilution methods yield reliable and reproducible (better than 10%) quantitative data for nickel and vanadium in crude oils and crude oil residues. Results demonstrate that the error associated with the loss of volatile metal containing compounds upon wet-ashing is within the reproducibility of the technique. Although wet-ashing may be slightly more reproducible, the flameless-dilution method is much simpler and faster and is recommended as the better of the two procedures for routine determinations of trace metals for oil identification.

  4. 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)…

  5. Mercury in Environmental and Biological Samples Using Online Combustion with Sequential Atomic Absorption and Fluorescence Measurements: A Direct Comparison of Two Fundamental Techniques in Spectrometry

    Science.gov (United States)

    Cizdziel, James V.

    2011-01-01

    In this laboratory experiment, students quantitatively determine the concentration of an element (mercury) in an environmental or biological sample while comparing and contrasting the fundamental techniques of atomic absorption spectrometry (AAS) and atomic fluorescence spectrometry (AFS). A mercury analyzer based on sample combustion,…

  6. Screening Technique for Lead and Cadmium in Toys and Other Materials Using Atomic Absorption Spectroscopy

    Science.gov (United States)

    Brouwer, Henry

    2005-01-01

    A simple procedure to quickly screen different consumer products for the presence of lead, cadmium, and other metals is described. This screening technique avoids expending a lot of preparation time on samples known to contain low levels of hazardous metals where only samples testing positive for the desired elements need to be analyzed…

  7. Evaluation of atomic absorption Spectrophotometry (ashing, non ...

    African Journals Online (AJOL)

    Three commonly used techniques, namely atomic absorption spectrophotometry (AAS-Ashing and AAS-Non Ashing) and titrimetry (potassium permanganate titration) have been evaluated in this study to determine the calcium content in six food samples whose calcium levels ranged from 0 to more than 250mg/100g ...

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

    Science.gov (United States)

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

    2008-07-01

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

  9. Analysis of trace element in intervertebral disc by Atomic Absorption Spectrometry techniques in degenerative disc disease in the Polish population

    Directory of Open Access Journals (Sweden)

    Andrzej Nowakowski

    2015-05-01

    Full Text Available Objective. Although trace elements are regarded crucial and their content has been determined in number of tissue there are only few papers addressing this problem in intervertebral disc in humans. Most of the trace elements are important substrates of enzymes influencing metabolism and senescence process. Others are markers of environmental pollution. Therefore the aim of the research was to analyzed of the trace element content in the intervertebral disc, which may be a vital argument recognizing the background of degenerative changes to be the effect of the environment or metabolic factors. Materials and methods. Material consist of 18 intervertebral disc from 15 patients, acquired in surgical procedure of due to the degenerative disease with Atomic Absorption Spectrometry content of Al, Cd, Co, Pb, Cu, Ni, Mo, Mg, Zn was evaluated. Results. Only 4 of the trace elements were detected in all samples. The correlation analysis showed significant positive age correlation with Al and negative in case of Co. Among elements significant positive correlation was observed between Al/Pb, Co/Mo, Al/Mg, Al/Zn Pb/Zn and Mg/Zn. Negative correlation was observed in Al/Co, Cd/Mg, Co/Mg, Mo/Mg, Co/Zn and Mo/Zn. Conclusions. This study is the first to our knowledge that profiles the elements in intervertebral disc in patients with degenerative changes. We have confirmed significant differences between the trace element contents in intervertebral disc and other tissue. It can be ground for further investigation.

  10. 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.

  11. Comparison of atomic absorption, mass and X-ray spectrometry techniques using dissolution-based and solid sampling methods for the determination of silver in polymeric samples

    Energy Technology Data Exchange (ETDEWEB)

    Schrijver, Isabel de [Ghent University, Department of Analytical Chemistry, Krijgslaan 281-S12, B-9000 Ghent (Belgium); University College West-Flanders, Department of Industrial Engineering and Technology, Research group EnBiChem, Graaf Karel de Goedelaan 5, B-8500 Kortrijk (Belgium); Aramendia, Maite; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, Krijgslaan 281-S12, B-9000 Ghent (Belgium); Resano, Martin [University of Zaragoza, Department of Analytical Chemistry, Pedro Cerbuna 12, E-50009 Zaragoza (Spain); Dumoulin, Ann [University College West-Flanders, Department of Industrial Engineering and Technology, Research group EnBiChem, Graaf Karel de Goedelaan 5, B-8500 Kortrijk (Belgium); Vanhaecke, Frank [Ghent University, Department of Analytical Chemistry, Krijgslaan 281-S12, B-9000 Ghent (Belgium)], E-mail: Frank.Vanhaecke@UGent.be

    2007-11-15

    In this work, the capabilities and limitations of solid sampling techniques - laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), wavelength dispersive X-ray fluorescence spectrometry (WD-XRFS) and solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS) - for the determination of silver in polymers have been evaluated and compared to those of acid digestion and subsequent Ag determination using pneumatic nebulization ICPMS (PN-ICPMS) or flame AAS (FAAS). In a first stage, two dissolution procedures were examined: conventional acid digestion in a Kjeldahl flask and the combination of dry ashing and microwave-assisted digestion. Accurate results for Ag could be obtained, although occasionally, problems of analyte losses and/or incomplete dissolution were observed. LA-ICPMS shows potential for direct analysis of solid materials, but calibration was found to be difficult. A polypropylene sample was used as standard. This approach provided satisfactory results for other polypropylene samples and even for other types of plastics, provided that the {sup 13}C{sup +} signal was used as internal reference, correcting for variations in ablation efficiency. However, the results for polyoxymethylene were overestimated. Similar calibration problems appeared with WD-XRFS, due to differences in absorption efficiency of X-rays. In this case, the accuracy could be improved by using a matrix correction procedure, which however required the matrix composition to be known into sufficient detail. SS-ETAAS, proved to be a fast approach that allowed accurate determination of Ag in polymers using aqueous standard solutions for calibration. Due to the high Ag content and the excellent sensitivity, the use of a 3-field mode Zeeman-effect background correction system was essential for the extension of the working range.

  12. Quantifying uncertainty in measurement of mercury in suspended particulate matter by cold vapor technique using atomic absorption spectrometry with hydride generator.

    Science.gov (United States)

    Singh, Nahar; Ahuja, Tarushee; Ojha, Vijay Narain; Soni, Daya; Tripathy, S Swarupa; Leito, Ivo

    2013-01-01

    As a result of rapid industrialization several chemical forms of organic and inorganic mercury are constantly introduced to the environment and affect humans and animals directly. All forms of mercury have toxic effects; therefore accurate measurement of mercury is of prime importance especially in suspended particulate matter (SPM) collected through high volume sampler (HVS). In the quantification of mercury in SPM samples several steps are involved from sampling to final result. The quality, reliability and confidence level of the analyzed data depends upon the measurement uncertainty of the whole process. Evaluation of measurement uncertainty of results is one of the requirements of the standard ISO/IEC 17025:2005 (European Standard EN IS/ISO/IEC 17025:2005, issue1:1-28, 2006). In the presented study the uncertainty estimation in mercury determination in suspended particulate matter (SPM) has been carried out using cold vapor Atomic Absorption Spectrometer-Hydride Generator (AAS-HG) technique followed by wet chemical digestion process. For the calculation of uncertainty, we have considered many general potential sources of uncertainty. After the analysis of data of seven diverse sites of Delhi, it has been concluded that the mercury concentration varies from 1.59 ± 0.37 to 14.5 ± 2.9 ng/m(3) with 95% confidence level (k = 2).

  13. A method optimization study for atomic absorption ...

    African Journals Online (AJOL)

    A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring ...

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

    Science.gov (United States)

    Slavin, Walter

    1982-01-01

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

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

    Science.gov (United States)

    Oxley, Paul; Wihbey, Joseph

    2016-09-01

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

  16. Measurement of frequency sweep nonlinearity using atomic absorption spectroscopy

    Science.gov (United States)

    Song, Ningfang; Lu, Xiangxiang; Xu, Xiaobin; Pan, Xiong; Li, Wei; Hu, Di; Liu, Jixun

    2018-01-01

    A novel scheme to determine frequency sweep nonlinearity using atomic saturated absorption spectroscopy is proposed and demonstrated. The frequency modulation rate is determined by directly measuring the interference fringe number and the frequency gap between two atomic transition peaks of rubidium atom. An experimental setup is established, and test results show that the frequency sweep nonlinearity is ∼10%, with an average frequency modulation rate of ∼1.12 THz/s. Moreover, the absolute optical frequency and optical path difference between two laser beams are simultaneously determined with this method. This low-cost technique can be used for optical frequency sweep nonlinearity correction and real-time frequency monitor.

  17. High sensitivity probe absorption technique for time-of-flight ...

    Indian Academy of Sciences (India)

    We report on a phase-sensitive probe absorption technique with high sensitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms. We demonstrate the ...

  18. 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

  19. 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.

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

    Science.gov (United States)

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

  1. Non-Dispersive Atomic Absorption System for Engine Health Monitoring Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to design, construct and test a first implementation of a non-dispersive technique for the measurement of atomic absorption in the plumes of liquid rocket...

  2. Reliability of graphite furnace atomic absorption spectrometry as ...

    African Journals Online (AJOL)

    Purpose: To evaluate the comparative efficiency of graphite furnace atomic absorption spectrometry (GFAAS) and hydride generation atomic absorption spectrometry (HGAAS) for trace analysis of arsenic (As) in natural herbal products (NHPs). Method: Arsenic analysis in natural herbal products and standard reference ...

  3. Absorption imaging of ultracold atoms on atom chips

    DEFF Research Database (Denmark)

    Smith, David A.; Aigner, Simon; Hofferberth, Sebastian

    2011-01-01

    Imaging ultracold atomic gases close to surfaces is an important tool for the detailed analysis of experiments carried out using atom chips. We describe the critical factors that need be considered, especially when the imaging beam is purposely reflected from the surface. In particular we present...... methods to measure the atom-surface distance, which is a prerequisite for magnetic field imaging and studies of atom surface-interactions....

  4. Determination of Lead in Blood by Atomic Absorption Spectrophotometry1

    Science.gov (United States)

    Selander, Stig; Cramér, Kim

    1968-01-01

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

  5. The role of atomic absorption spectrometry in geochemical exploration

    Science.gov (United States)

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

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Paesler, M.; Sayers, D.

    1988-12-01

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

  7. 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…

  8. Two-Photon Coherent Atomic Absorption of Multiple Laser Beams

    Science.gov (United States)

    Li, Ming-Chiang

    2006-05-01

    Physical processes on two-photon coherent atomic absorption of multiple laser beams were discussed about thirty years ago [M. C. Li, Bull. Am. Phys. Soc. 20, 654 (1975)]. These processes can be divided into two distinct groups. In the first group, laser beams are from a single source, and in the second group laser beams are from two different sources [M. C. Li, Phys. Rev. A 22 (1980) 1323]. Several experiments in the first group were carried out and have led to the 2005 Nobel Prize in physics. The second group is more interesting. Beside atoms are in random motion, two photons are from different sources. Classically, it is impossible for atoms to transit coherently in the absorption process, but quantum mechanically, such a transition is possible and that is one of the spooky phenomena in quantum mechanic. To assure the coherent transition, each photon as absorbed by the atom must have two possible paths of choices. If one photon has the choice and other one is not, then the atomic transitions cannot be coherent. Around1990, there were very active experimental pursuits on such a spooky phenomenon of two photons emitted from crystal parametric down conversion. The present talk will review various spooky phenomena associated with two-photon coherent atomic absorption. Hope that the talk will stimulate the interest on the long neglected experimental front on two-photon coherent atomic absorption from two different laser sources.

  9. Laser techniques for spectroscopy of core-excited atomic levels

    Science.gov (United States)

    Harris, S. E.; Young, J. F.; Falcone, R. W.; Rothenberg, J. E.; Willison, J. R.

    1982-01-01

    We discuss three techniques which allow the use of tunable lasers for high resolution and picosecond time scale spectroscopy of core-excited atomic levels. These are: anti-Stokes absorption spectroscopy, laser induced emission from metastable levels, and laser designation of selected core-excited levels.

  10. Determination of Lead in Urine by Atomic Absorption Spectrophotometry1

    Science.gov (United States)

    Selander, Stig; Cramé, Kim

    1968-01-01

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

  11. Spooky Phenomena in Two-Photon Coherent Atomic Absorption

    Science.gov (United States)

    Li, Ming-Chiang

    2006-03-01

    Physical processes on two-photon coherent atomic absorption of multiple laser beams were discussed more than twenty five years ago. These processes can be divided into two distinct groups. In the first group, laser beams are from a single source^1,2, and in the second group laser beams are from two different sources^3. Several experiments in the first group were carried out and have led to the 2005 Nobel Prize in physics. The second group is more interesting. Atoms are in random motion and two photons are from different sources. Classically, it is impossible for atoms to transit coherently in the absorption process, but quantum mechanically, such a transition is possible and that is one of the spooky phenomena in quantum mechanic. To assure the coherent transition, each photon as absorbed by the atom must have two possible paths of choices. If one photon has the choice and other one is not, then the atomic transitions cannot be coherent. The present talk will review various spooky phenomena associated with two-photon coherent atomic absorption, and will clarify some theoretical misunderstandings regarding these interesting transitions. Reference: *M. C. Li, Nuovo Cimento 39B (1977) 165. *M. C. Li, Phys. Rev. A 16 (1977) 2480. *M. C. Li, Phys. Rev. A 22 (1980) 1323.

  12. Pigment identification in artwork using graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Goltz, D M; Coombs, J; Marion, C; Cloutis, E; Gibson, J; Attas, M; Choo-Smith, L-P; Collins, C

    2004-06-17

    The use of a sampling technique is described for the identification of metals from inorganic pigments in paint. The sampling technique involves gently contacting a cotton swab with the painted surface to physically remove a minute quantity ( approximately 1-2mug) of pigment. The amount of material removed from the painted surface is invisible to the unaided eye and does not cause any visible effect to the painted surface. The cotton swab was then placed in a 1.5ml polystyrene beaker containing HNO(3) to extract pigment metals prior to analysis using graphite furnace atomic absorption spectrometry (GFAAS). GFAAS is well suited for identifying pigment metals since it requires small samples and many pigments consist of main group elements (e.g. Al) as well as transition metals (e.g. Zn, Fe and Cd). Using Cd (cadmium red) as the test element, the reproducibility of sampling a paint surface with the cotton swab was approximately 13% in either a water or oil medium. To test the feasibility of cotton sampling for pigment identification, samples were obtained from paintings (watercolour and oil) of a local collection. Raman spectra provided complementary information to the GFAAS, which together are essential for positive identification of some pigments. For example, GFAAS indicated the presence of Cu, but the Raman spectra positively identified the modern copper pigment phthalocyanine green (Cu(C(32)Cl(16)N(8)). Both Raman spectroscopy and GFAAS were useful for identifying ZnO as a white pigment.

  13. determination of vanadium in foods by atomic absorption spectrometry

    African Journals Online (AJOL)

    This paper presents an assessment of the level of vanadium in foods (Plantain, Musa spp; Yam, Discorea rotundata; and Maize, Zea mays) from ten popular market places in Lagos metropolis, Nigeria. Total acid leaching digestion method was employed and determination was by Flame Atomic Absorption ...

  14. Developing a Transdisciplinary Teaching Implement for Atomic Absorption Spectroscopy

    Science.gov (United States)

    Drew, John

    2008-01-01

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

  15. Reliability of graphite furnace atomic absorption spectrometry as ...

    African Journals Online (AJOL)

    Original Research Article. Reliability of graphite furnace atomic absorption spectrometry as alternative method for trace analysis of arsenic in natural medicinal products. Reem Saadi Khalid1*, ABM Helaluddin1, Reem Saadi Khalid1, Mohamed. Alaama1, Abdualrahman M Abdualkader1, Abdulrazak Kasmuri2 and Syed Atif.

  16. combination of flame atomic absorption spectrometry with ligandless

    African Journals Online (AJOL)

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    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 .... in ethanol was added to it. The final solution was aspirated directly into the flame of AAS. The extraction scheme of Pb(II) ion is shown in.

  17. Continuum Source Atomic Absorption Spectrometry with a Photodiode Array Detector

    Science.gov (United States)

    Fernando, Reshan Armedious

    The designed continuum source atomic absorption spectrometer consists of a 300W xenon arc lamp (ILC Technology), a flame (Perkin-Elmer) or graphite furnace (Perkin-Elmer, Model HGA 2200) atomizer, a 1.33M focal length high resolution monochromator with 3600 gr/mm grating (McPherson, Model 209), and a 2048-element self scanning linear photodiode array detector (Princeton Instruments, Model PDA-2048). Detector operation, data acquisition and processing was done by using a 66MHz 486 DX/2 personal computer (Gateway 2000). In stage one, the system was optimized for flame atomization. The optimum lamp current, entrance slit width and height were found to be 10A, 20 mum, and 4 mm respectively. The resulted spectral band-pass of the monochromator/PDA combination is on the order of the average atomic absorption profile half-width (0.003 -0.004 nm). The flame parameters such as observation height, air/fuel ratio, and solution uptake rate were optimized along with the detector parameters such as exposure and accumulation for the lowest possible detection limit. The system has clearly demonstrated its multi-element detection capabilities. The calculated detection limits for the present system with an air-acetylene flame is approximately one order of magnitude lower than previously reported CSAAS detection limits, and are on the same order of magnitude as those commonly observed with single element hollow cathode lamp systems. In stage two, flame atomizer was replaced by a graphite furnace atomizer. When compared to the static signal given out by flame atomizer, the graphite furnace produces transient signals. Fast response time of the PDA is well within the time scale of the transient signals produce in graphite furnace and the multi-wavelength detection allows the background correction to be performed by visual inspection. The detection limits calculated for the present system are significantly lower than those previously reported for multi-element CSAAS systems, and are on

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

    Science.gov (United States)

    Kane, J.S.

    1979-01-01

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

  19. Determination of total mercury by vapor generation in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Poznan Technical University, Poznan (Poland)

    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 determination of total mercury in environmental samples. Mercury, using formation of mercury vapors were atomized in air-acetylene flame-heated IAT. A new design of vapor generation integrated atom trap flame atomic absorption spectrometry (VG-IAT-FAAS) hyphenated technique that would exceed the operational capabilities of existing arrangements was investigated. This novel approach enables to decrease the detection limit down to low pg mL{sup -1} levels. The concentration detection limit, defined as 3 times the blank standard deviation was 0.4 ng mL{sup -1}. For a 120 s in situ pre-concentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 750 folds for Hg, using vapor generation-atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed by RSD, was 9.3% (n = 6) for Hg. Reference and real sample materials were analyzed. The accuracy of the method was verified by the use of certified reference materials and by aqueous standard calibration technique. The measured Hg content, in reference materials, were in satisfactory agreement with the certified values, The hyphenated technique was applied for mercury determinations in coal fly ash, sewage and water.

  20. High sensitivity probe absorption technique for time-of-flight ...

    Indian Academy of Sciences (India)

    Absorption imaging using a high sensitivity CCD camera gives the size of the expanding cloud and hence ... (LVIS) [2], the peak signal in a 1 mm thick resonant probe beam corresponds to the absorption by 3 × 105 ... used in our atom optics experiments on the reflection of atoms from magnetic thin films [13]. The sensitivity ...

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

    Science.gov (United States)

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

    1984-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

    Arslan, Y.; Musil, Stanislav; Matoušek, Tomáš; Kratzer, Jan; Dědina, Jiří

    103-104, JAN-FEB (2015), s. 155-163 ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : gold * volatile species generation * quartz atomizers * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015

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

    Science.gov (United States)

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

    1981-01-01

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

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

    Science.gov (United States)

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

    2008-09-15

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

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

    Science.gov (United States)

    Williamson, Mark A.

    1989-01-01

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

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

    Science.gov (United States)

    2010-04-01

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

  7. Dielectric barrier discharge plasma atomizer for hydride generation atomic absorption spectrometry-Performance evaluation for selenium

    Czech Academy of Sciences Publication Activity Database

    Duben, Ondřej; Boušek, J.; Dědina, Jiří; Kratzer, Jan

    2015-01-01

    Roč. 111, SEP (2015), s. 57-63 ISSN 0584-8547 Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation-atomic absorption spectrometry * selenium Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015

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

    Science.gov (United States)

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

    2005-05-01

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

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

    Science.gov (United States)

    Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; Garcia, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.; hide

    2013-01-01

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

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

    Science.gov (United States)

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

    1971-01-01

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

  11. Spectral features of electromagnetically induced absorption in 85Rb atoms

    Science.gov (United States)

    Rehman, Hafeez-ur; Adnan, Muhammad; Noh, Heung-Ryoul; Kim, Jin-Tae

    2015-06-01

    We present theoretical and experimental studies of electromagnetically induced absorption (EIA) for the {{F}g}=3\\to {{F}e}=4 transition of 85Rb-D2 line. From the results calculated by solving time-dependent density-matrix equations including the optical and Zeeman coherences connected via three-photon interactions, the EIA signals have ultra-narrow feature in low powers of coupling beam in both same- and orthogonal-polarization configurations for both stationary and thermal atoms. However, the ultra-narrow EIA signals from high powers of coupling laser beam still remained in the ultra-narrow state only in the same-polarization configuration for thermal atoms. The calculated results match well with experimental results except ultra-narrow EIA region considering linewidths of two separate coupling and probe lasers.

  12. SPECTROPHOTOMETRIC, ATOMIC ABSORPTION AND CONDUCTOMETRIC ANALYSIS OF TRAMADOL HYDROCHLORIDE

    Directory of Open Access Journals (Sweden)

    Sara M. Anis

    2011-09-01

    Full Text Available Six simple and sensitive spectroscopic and conductometric procedures (A-F were developed for the determination of tramadol hydrochloride. Methods A, B and C are based on the reaction of cobalt (II thiocyanate with tramadol to form a stable ternary complex, which could be measured by spectrophotometric (method A, atomic absorption (method B or conductometric (method C procedures. Methods D and E depend on the reaction of molybdenum thiocyanate with tramadol to form a stable ternary complex, measured by spectrophotometric means (method D or by atomic absorption procedures (method E, while method F depends on the formation of an ion pair complex between the studied drug and bromothymol blue which is extractable into methylene chloride. Tramadol hydrochloride could be assayed in the range of 80-560 and 40-–220 μg ml-1, 1-15 mg ml-1 and 2.5-22.5, 1.25-11.25 and 5-22 μg ml-1 using methods A,B,C,D,E and F, respectively. Various experimental conditions were studied. The results obtained showed good recoveries. The proposed procedures were applied successfully to the analysis of tramadol in its pharmaceutical preparations and the results were favorably comparable with the official method.

  13. 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.

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

    Science.gov (United States)

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

    2016-04-05

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

  15. Novel atomic absorption spectrometric and rapid spectrophotometric methods for the quantitation of paracetamol in saliva: application to pharmacokinetic studies.

    Science.gov (United States)

    Issa, M M; Nejem, R M; El-Abadla, N S; Al-Kholy, M; Saleh, Akila A

    2008-01-01

    A novel atomic absorption spectrometric method and two highly sensitive spectrophotometric methods were developed for the determination of paracetamol. These techniques based on the oxidation of paracetamol by iron (III) (method I); oxidation of p-aminophenol after the hydrolysis of paracetamol (method II). Iron (II) then reacts with potassium ferricyanide to form Prussian blue color with a maximum absorbance at 700 nm. The atomic absorption method was accomplished by extracting the excess iron (III) in method II and aspirates the aqueous layer into air-acetylene flame to measure the absorbance of iron (II) at 302.1 nm. The reactions have been spectrometrically evaluated to attain optimum experimental conditions. Linear responses were exhibited over the ranges 1.0-10, 0.2-2.0 and 0.1-1.0 mug/ml for method I, method II and atomic absorption spectrometric method, respectively. A high sensitivity is recorded for the proposed methods I and II and atomic absorption spectrometric method value indicate: 0.05, 0.022 and 0.012 mug/ml, respectively. The limit of quantitation of paracetamol by method II and atomic absorption spectrometric method were 0.20 and 0.10 mug/ml. Method II and the atomic absorption spectrometric method were applied to demonstrate a pharmacokinetic study by means of salivary samples in normal volunteers who received 1.0 g paracetamol. Intra and inter-day precision did not exceed 6.9%.

  16. Direct solid sampling by flame atomic absorption spectrometry: determination of manganese in coal samples

    Directory of Open Access Journals (Sweden)

    Flores Érico M. M.

    2004-01-01

    Full Text Available A new device for the direct solid analysis by flame atomic absorption spectrometry was investigated as an alternative technique for the determination of trace elements in coal. The potential application of the proposed procedure for the determination of manganese was investigated. Ground coal test samples were weighed directly into polyethylene vials and carried as a dry aerosol to a slotted quartz vaporization cell placed between the flame burner and optical path. The transient signals obtained were totally integrated in 1 second. The effect of operating conditions on the analytical signal was investigated. Background signals were always low and a Mn characteristic mass of 1.9 ng was found. Results were considered satisfactory regarding to both accuracy (between 97.5 and 103.2% and precision (RSD better than 6%. The proposed system is simple and can be easily adapted to any conventional atomic absorption spectrometers allowing the analysis of more than 80 test samples in an hour.

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

    Science.gov (United States)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    1987-01-01

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

  19. Novel absorption detection techniques for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Yongjun [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the μM level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  20. Flow Injection and Atomic Absorption Spectrometry - An Effective and Attractive Analytical Chemical Combination

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Nielsen, Steffen

    1998-01-01

    One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic...... absorption spectrometry (AAS). Initially with flame-AAS (FAAS) procedures, later for hydride generation (HG) techniques, and most recently in combination with electrothermal AAS (ETAAS). The common denominator for all these procedures is the inherently precise and strictly reproducible timing that the sample...

  1. Atmospheric Deposition of Heavy Metals around the Lead and Copper-Zinc Smelters in Baia Mare, Romania, Studied by the Moss Biomonitoring Technique, Neutron Activation Analysis and Flame Atomic Absorption Spectrometry

    CERN Document Server

    Culicov, O A; Steinnes, E; Okina, O S; Santa, Z; Todoran, R

    2002-01-01

    The mosses Pleurozium schreberi, Pseudoscleropodium purum and Rhytidiadelphus squarrosus were used as biomonitors to study the atmospheric deposition of heavy metals around the lead and copper-zinc smelters in Baia Mare. Samples representing the last three years' growth of moss or its green part, collected on the ground at 28 sites located 2-17 km from the source area, were analyzed by instrumental neutron activation analysis using epithermal neutrons and by flame atomic absorption spectrometry. A total of 31 elements were determined, including most of the heavy metals characteristic of emissions from this kind industry. The observed data for Pb, As, Cu, and Cd are all high compared with those observed in other regions of Europe with similar industries, but the concentrations in moss approach regional background levels at a distance of about 8 km from the main source area. Factor analysis of the data distinguishes two industrial components, one characterized by Pb, Cu, As, and Sb, and another one by Zn and Cd...

  2. Biosorption using chitosan thiourea polymer as an extraction and preconcentration technique for copper prior to its determination in environmental and food samples by flame atomic absorption spectrometry: Synthesis, characterization and analytical applications.

    Science.gov (United States)

    Al-Saidi, H M

    2016-12-01

    The present work describes the synthesis and use of the chitosan thiourea polymer (CT polymer) as a novel biosorbent for copper preconcentration prior to its determination by flame atomic absorption spectrometry (FAAS). CT polymer submitted in the present study was synthesized by the direct reaction between chitosan isolated from penaeus monodon chitin and ammonium thiocyanate, then the chemical structure and morphology of polymer were investigated by spectroscopic measurements, thermal analysis, X-ray diffraction (XRD) and scanning electron microscope (SEM). The results of SEM and XRD show that the prepared CT polymer has rough and hard surface with pores and nanofibers structure in the α-form. The height equivalent to the theoretical plates (HETP), the plates number (N), LOD and LOQ of CT polymer packed column were calculated to be 0.10±0.04mm, 100±2.02, 0.3μgL(-1)and 0.99μgL(-1), respectively. The developed column was employed in combination with FAAS for the analysis of copper in a certified reference material (NRCC-SLRS-4 Riverine water), potato, tea, and rice. Furthermore, the structure of the copper complex with CT polymer was proven with the aid of different spectroscopic and magnetic measurements. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2015-02-01

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

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

    Science.gov (United States)

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

    2008-06-01

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

  5. Flow Injection and Atomic Absorption Spectrometry (FI-AAS) -

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1996-01-01

    absorption spectrometry (AAS). Initially with flame-AAS (fAAS) procedures, later for hydride generation (HG) techniques, and most recently in combination with electrothermal AAS (ETAAS). The common denominator for all these procedures is the inherently precise and strictly reproducible timing in FI from...... the point of sample injection/introduction to the point of detection. Hence, in FI-fAAS this feature allows not only to obtain improved repeatability but also improved accuracy, and because the wash to sample ratio is high it permits the handling of samples with elevated salt contents - which...... of (especially HG- forming) elements. In the words of the one of the authorities of AAS and foremost pioneers of FI-AAS - Professor Z. L. Fang, who is the author on two recently published monographs on this hyphenated technique - the impact of FI on AAS is "so dramatic" that it has brought "new vitality...

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

    Science.gov (United States)

    Parsons, Patrick J.; Slavin, Walter

    1999-05-01

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

  7. Comparison of 4 analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs

    OpenAIRE

    2011-01-01

    Abstract Different techniques for the determination of total tin in beverage and canned food by atomic spectrometry were compared. The performance characteristics of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Hydride Generation Inductively Coupled Plasma Atomic Emission Spectrometry (HG-ICP-AES), Electrothermal Atomization Atomic Absorption Spectrometry (ETA-AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) were determined in term of linearity, ...

  8. A Sensitive Method for Cadmium Determination Using an On-line Polyurethane Foam Preconcentration System and Thermospray Flame Furnace Atomic Absorption Spectrometry

    National Research Council Canada - National Science Library

    TARLEY, César Ricardo Teixeira; ARRUDA, Marco Aurélio Zezzi

    2004-01-01

    A new sensitive and low cost method for cadmium determination at µg l-1 levels that combines an on-line preconcentration system with the thermospray flame furnace atomic absorption spectrometry technique (TS-FF-AAS...

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

    Science.gov (United States)

    Thin, Christian G.; Thomson, Patricia A.

    1967-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Fara, M.; Novak, F. [EGU Prague, PLC, Bichovice, Prague (Czechoslovakia)

    1995-12-01

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

  11. VUV absorption spectroscopy measurements of the role of fast neutral atoms in a high-power gap breakdown

    Science.gov (United States)

    Filuk; Bailey; Cuneo; Lake; Nash; Noack; Maron

    2000-12-01

    The maximum power achieved in a wide variety of high-power devices, including electron and ion diodes, z pinches, and microwave generators, is presently limited by anode-cathode gap breakdown. A frequently discussed hypothesis for this effect is ionization of fast neutral atoms injected throughout the anode-cathode gap during the power pulse. We describe a newly developed diagnostic tool that provides a direct test of this hypothesis. Time-resolved vacuum-ultraviolet absorption spectroscopy is used to directly probe fast neutral atoms with 1-mm spatial resolution in the 10-mm anode-cathode gap of the SABRE 5 MV, 1 TW applied-B ion diode. Absorption spectra collected during Ar RF glow discharges and with CO2 gas fills confirm the reliability of the diagnostic technique. Throughout the 50-100 ns ion diode pulses no measurable neutral absorption was seen, setting upper limits of (0.12-1.5)x10(14) cm(-3) for ground-state fast neutral atom densities of H, C, N, O, and F. The absence of molecular absorption bands also sets upper limits of (0.16-1.2)x10(15) cm(-3) for common simple molecules. These limits are low enough to rule out ionization of fast neutral atoms as a breakdown mechanism. Breakdown due to ionization of molecules is also found to be unlikely. This technique can now be applied to quantify the role of neutral atoms in other high-power devices.

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

    Science.gov (United States)

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

    1967-01-01

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

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

    Science.gov (United States)

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

    2009-06-22

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

  14. Multiphoton laser wave-mixing absorption spectroscopy for samarium using a graphite furnace atomizer

    Energy Technology Data Exchange (ETDEWEB)

    Maniaci, Michael J.; Tong, William G. E-mail: william.tong@sdsu.edu

    2004-07-30

    Nonlinear laser wave-mixing optical technique is presented as a sensitive atomic spectroscopic method for the analysis of rare earth elements using an unmodified commercially available graphite furnace (GF) atomizer. A simple nonplanar backward-scattering degenerate four-wave mixing optical arrangement offers sub-picogram detection sensitivity with sub-Doppler Lorentzian-broadened resolution. Nonlinear wave mixing is an unusually sensitive absorption-based optical method that offers both excellent detection sensitivity and sub-Doppler spectral resolution. A mass detection limit of 0.7 pg and a concentration detection limit of 70 pg/ml are determined for a rare earth element, samarium, using the 429.7-nm excitation line.

  15. METHODS OF SAMPLE THERMAL MODIFICATION BY MEANS DOUBLE VAPORIZATION IN TWO STEP ATOMIZER FOR ATOMIC ABSORPTION ANALYSIS

    OpenAIRE

    Grinshtein, Ilia; Vilpan, Yuri; Saraev, Alexei; Vasilieva, Lubov

    2000-01-01

    After sample vaporization in two-step atomizer with a purged vaporizer sample vapors can be transferred into preheated or into non-heated atomizer. In the last case the atomizer walls trap the vapors and then the sample is second time vaporized and atomized by heating the atomizer. Thermal pre-treatment of a sample using this double vaporization makes possible the direct analysis of samples with strongly interfering matrices including solids. The technique was used for the direct determinatio...

  16. Laser stabilisation for velocity-selective atomic absorption

    NARCIS (Netherlands)

    Meijer, H.A.J.; Meulen, H.P. van der; Ditewig, F.; Wisman, C.J.; Morgenstern, R.

    1987-01-01

    A relatively simple method is described for stabilising a dye laser at a frequency ν = ν0 + νc in the vicinity of an atomic resonance frequency ν0. The Doppler effect is exploited by looking for atomic fluorescence when a laser beam is crossed with an atomic beam at certain angles αi. Absolute

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

    Science.gov (United States)

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

    2016-12-01

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

  18. Transmission and reflection of electromagnetically induced absorption grating in homogeneous atomic media.

    Science.gov (United States)

    Kuang, Shang-qi; Wan, Ren-gang; Du, Peng; Jiang, Yun; Gao, Jin-yue

    2008-09-29

    We theoretically study the transmission and reflection of the probe travelling wave in an electromagnetically induced absorption grating (EIG), which is created in a three-level Lambda-type atomic system when the coupling field is a standing wave. Using the system, we show that a photonic stop band can exist on one side away from the resonance point in ultracold atomic gas, while there is an enhanced absorption at resonance and small reflection around it in the thermal atomic gas. Because our method can deal with such two cases, it is helpful to further understand the effects of the Doppler effect on atomic coherence and interference.

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

    Science.gov (United States)

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

  20. Understanding the mechanism of H atom absorption in the Pd(1 1 0) surface

    Energy Technology Data Exchange (ETDEWEB)

    Padama, Allan Abraham B. [Institute of Mathematical Sciences and Physics, College of Arts and Sciences, University of the Philippines Los Baños, Los Baños, Laguna 4031 (Philippines); Kasai, Hideaki, E-mail: kasai@dyn.ap.eg.osaka-u.ac.jp [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Center for Atomic and Molecular Technologies, Osaka University, Suita, Osaka 565-0871 (Japan); Center for Continuing Professional Development, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)

    2015-10-05

    Highlights: • This study elucidates the absorption of H in Pd(1 1 0) (1 × 2) missing-row surface. • Electronic structure depicts the stronger adsorption on ridge than on trough site. • The geometry of missing-row Pd(1 1 0) allows Pd atoms to accommodate H and H{sub 2}. • Assisted absorption is facilitated by the repulsion between H atoms. - Abstract: The underlying mechanism of H atom absorption in the Pd(1 1 0) (1 × 2) missing-row reconstructed surface is investigated by performing density functional theory based calculations. The stronger binding energy of H on ridge than on trough site of the missing-row surface is due to the more pronounced creation of derived bonding state as had been depicted from the electronic structure of the system. Hydrogen absorption takes place with the involvement of other incoming H atoms through an assisted absorption process that is facilitated by the repulsion between the incoming H and the absorbing H. The geometry of the missing-row surface enables the Pd atoms to accommodate the H atoms efficiently leading to H absorption as well as H{sub 2} dissociation.

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

    Science.gov (United States)

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

    2017-08-01

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

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

    Science.gov (United States)

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

    2016-09-14

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

  3. Development of an analytical model for the determination of {sup 60}Co in aqueous samples by atomic absorption and gamma spectrometry techniques; Elaboracion de un modelo analitico para la determinacion de {sup 60}Co en muestras acuosas mediante tecnicas de absorcion atomica y espectrometria gamma

    Energy Technology Data Exchange (ETDEWEB)

    Solis A, N. A.

    2015-07-01

    The applications of the nuclear energy in industry and medicine generate radioactive wastes that must be isolated and confined in order to limit its spread in the biosphere. These types of wastes are generated in hospitals, industry, research centers and nuclear power plants (during de fuel cycle). The radioactive elements (radionuclides) cannot be destroyed by any known method, either chemical or mechanical. Its final destruction is produced by radioactive decay, which makes them stable isotopes, or nuclear transmutation being bombarded with atomic particles. Consequently, the radioactive waste management is to control the radioactive discharges and reduce to tolerable limits, eliminating of effluents and wastes the radionuclides of interest, concentrating them so they can be stored or evacuated so that later not appear in dangerous concentration in the biosphere. In Mexico, the main generators of radioactive wastes are the nuclear power plant of Laguna Verde in Veracruz, Hospitals of the public and private sector, in addition Instituto Nacional de Investigaciones Nucleares (ININ) some institutes and facilities of the UNAM and Instituto Politecnico Nacional (IPN) and industries among others. The aqueous radioactive wastes, particularly those from the nuclear power plants contain traces of cobalt-60. Currently there is no model or analytical technique for the separation of this radionuclide, so it became necessary to develop an analytical model for separation and facilitate their disposal. In this paper was shown that atomic absorption and gamma spectrometry techniques can separate the active concentration of the inactive, which is important because the total concentration can be associated through direct relationships with the wear of metal parts of the nuclear reactor, since the metal alloys of the same reactor containing a fraction of cobalt. Also this analytical and mathematical model that can be reproducible and applicable to full sets of samples and that this

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

    Science.gov (United States)

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

    2016-05-20

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

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

    Science.gov (United States)

    Blomfield, Jeanette; Macmahon, R. A.

    1969-01-01

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

  6. Direct determination of selenoproteins in polyvinylidene difluoride membranes by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Sidenius, U; Gammelgaard, Bente

    2000-01-01

    A method for the direct determination of selenoproteins in plastic membranes after protein separation by gel electrophoresis was developed. Quantification was based on the determination of the selenium content of the proteins by electrothermal atomic absorption spectrometry (ET-AAS) after manual...... were excised and chemical modifier was added on top of the excised membrane prior to atomic absorption measurement. Acceptable linearity was achieved in the range 2-10 ng Se, corresponding to selenium concentrations close to 1 mg/L, when aqueous solutions of selenomethionine standard as well...

  7. Determination of serum lithium: comparison between atomic emission and absorption spectrometry methods

    Directory of Open Access Journals (Sweden)

    Carlos Elielton do Espírito Santo

    2014-02-01

    Full Text Available Introduction: The therapeutic monitoring of lithium, through concentration measurements, is important for individual dose adjustment, as a marker of treatment adherence and to prevent poisoning and side effects. Objectives: Validate and compare two methods - atomic emission and atomic absorption - for the determination of lithium in serum samples. Methodology: Parameters such as specificity, precision, accuracy, limit of detection (LOD and linearity were considered. The atomic absorption spectrometer was used, operating in either emission or absorption mode. For the quantitative comparison of 30 serum samples from patients with mood disorder treated with lithium, the results were submitted to Student's t-test, F-test and Pearson's correlation. Results: The limit of quantification (LOQ was established as 0.05 mEq/l of lithium, and calibration curves were constructed in the range of 0.05-2 mEq/l of lithium, using aqueous standards. Sample preparation time was reduced, what is important in medical laboratory. Conclusion: Both methods were considered satisfactory, precise and accurate and can be adopted for lithium quantification. In the comparison of quantitative results in lithium-treated patients through statistical tests, no significant differences were observed. Therefore the methods for lithium quantification by flame atomic absorption spectrometry (FAAS and flame atomic emission spectrometry (FAES may be considered similar.

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

    Energy Technology Data Exchange (ETDEWEB)

    Heinrich, Hans-Joachim [Federal Institute for Materials Research and Testing (BAM), Division I.1 Inorganic Chemical Analysis, Reference Materials, Richard-Willstaetter-Strasse 11, D-12489 Berlin (Germany)], E-mail: hans-joachim.heinrich@bam.de; Matschat, Ralf [Federal Institute for Materials Research and Testing (BAM), Division I.1 Inorganic Chemical Analysis, Reference Materials, Richard-Willstaetter-Strasse 11, D-12489 Berlin (Germany)

    2007-08-15

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

  9. Differentiation and classification of beers with flame atomic spectrometry and molecular absorption spectrometry and sample preparation assisted by microwaves

    Science.gov (United States)

    Bellido-Milla, Dolores; Moreno-Perez, Juana M.; Hernández-Artiga, María. P.

    2000-07-01

    The characterization of beer samples has a lot of interest because their composition can affect the taste and stability of beer and consumer health. Flame atomic absorption spectrometry was used to determine Fe, Mn, Zn, Cu, Mg, Ca and Al. Sodium and K were determined by flame atomic emission spectrometry. A sample preparation method was developed, based on treatment with HNO 3 and H 2O 2 in a microwave oven. This has many advantages over the methods found in the literature. The combination of the results of atomic spectrometry and the spectrum obtained by molecular absorption spectrometry provides information on the inorganic and organic components of the samples. The application of chemometric techniques to chemical composition data could be extremely useful for food quality control. The metal concentrations, the molecular absorption spectrum, the pH and conductivity of each sample were subject to analysis of variance and linear discriminant analysis. Twenty-five different beer samples were used to differentiate and classify different types of beers.

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

    Science.gov (United States)

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

    2012-12-21

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

  11. Determination of mercury in hair: Comparison between gold amalgamation-atomic absorption spectrometry and mass spectrometry.

    Science.gov (United States)

    Domanico, Francesco; Forte, Giovanni; Majorani, Costanza; Senofonte, Oreste; Petrucci, Francesco; Pezzi, Vincenzo; Alimonti, Alessandro

    2017-09-01

    Mercury is a heavy metal that causes serious health problems in exposed subjects. The most toxic form, i.e., methylmercury (MeHg), is mostly excreted through human hair. Numerous analytical methods are available for total Hg analysis in human hair, including cold vapour atomic fluorescence spectrometry (CV-AFS), inductively coupled plasma mass spectrometry (ICP-MS) and thermal decomposition amalgamation atomic absorption spectrometry (TDA-AAS). The aim of the study was to compare the TDA-AAS with the ICP-MS in the Hg quantification in human hair. After the washing procedure to minimize the external contamination, from each hair sample two aliquots were taken; the first was used for direct analysis of Hg by TDA-AAS and the second was digested for Hg determination by the ICP-MS. Results indicated that the two data sets were fully comparable (median; TDA-AAS, 475ngg -1 ; ICP-MS, 437ngg -1 ) and were not statistically different (Mann-Whitney test; p=0.44). The two techniques presented results with a good coefficient of correlation (r=0.94) despite different operative ranges and method limits. Both techniques satisfied internal performance requirements and the parameters for method validation resulting sensitive, precise and reliable. Finally, the use of the TDA-AAS can be considered instead of the ICP-MS in hair analysis in order to reduce sample manipulation with minor risk of contamination, less time consuming due to the absence of the digestion step and cheaper analyses. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. Fitness analysis method for magnesium in drinking water with atomic absorption using quadratic curve calibration

    Directory of Open Access Journals (Sweden)

    Esteban Pérez-López

    2014-11-01

    Full Text Available Because of the importance of quantitative chemical analysis in research, quality control, sales of services and other areas of interest , and the limiting of some instrumental analysis methods for quantification with linear calibration curve, sometimes because the short linear dynamic ranges of the analyte, and sometimes by limiting the technique itself, is that there is a need to investigate a little more about the convenience of using quadratic curves for analytical quantification, which seeks demonstrate that it is a valid calculation model for chemical analysis instruments. To this was taken as an analysis method based on the technique and atomic absorption spectroscopy in particular a determination of magnesium in a sample of drinking water Tacares sector Northern Grecia, employing a nonlinear calibration curve and a curve specific quadratic behavior, which was compared with the test results obtained for the same analysis with a linear calibration curve. The results show that the methodology is valid for the determination referred to, with all confidence, since the concentrations are very similar, and as used hypothesis testing can be considered equal.

  13. Differential Absorption Lidar Mapping of Atmospheric Atomic Mercury in Italian Geothermal Fields

    Science.gov (United States)

    Edner, H.; Ragnarson, P.; Svanberg, S.; Wallinder, E.; de Liso, A.; Ferrara, R.; Maserti, B. E.

    1992-03-01

    Results from extensive lidar measurements on atmospheric atomic mercury in Italian geothermal fields are reported. A mobile differential absorption lidar system operating on the 254-nm mercury resonance line with a measuring range of about 1 km was used in mineralized as well as nonmineralized areas. Measurements were performed at geothermal power stations and in an unexploited field with natural surface geothermic manifestations. Atomic mercury concentrations ranging from 2 to 1000 ng/m3 were mapped. The high Italian geothermal mercury concentrations are in strong contrast to the recent lidar finding of the absence of atomic mercury in Icelandic geothermal fields.

  14. Determination of As, Cd, Cu, Hg and Pb in biological samples by modern electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sardans, Jordi, E-mail: j.sardans@creaf.uab.ca [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain); Montes, Fernando [Departamento de Ciencias Analiticas, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia (UNED), C/ Senda del Rey 9. 28040 Madrid (Spain); Penuelas, Josep [Ecophysiological and Global Change Unit CSIC-CREAF, Edifici C, Universitat Autonoma de Barcelona, Bellaterra 08193, Barcelona (Spain)

    2010-02-15

    Pollution from heavy metals has increased in recent decades and has become an important concern for environmental agencies. Arsenic, cadmium, copper, mercury and lead are among the trace elements that have the greatest impact and carry the highest risk to human health. Electrothermal atomic absorption spectrometry (ETAAS) has long been used for trace element analyses and over the past few years, the main constraints of atomic absorption spectrometry (AAS) methods, namely matrix interferences that provoked high background absorption and interferences, have been reduced. The use of new, more efficient modifiers and in situ trapping methods for stabilization and pre-concentration of these analytes, progress in control of atomization temperatures, new designs of atomizers and advances in methods to correct background spectral interferences have permitted an improvement in sensitivity, an increase in detection power, reduction in sample manipulation, and increase in the reproducibility of the results. These advances have enhanced the utility of Electrothermal atomic absorption spectrometry (ETAAS) for trace element determination at mug L{sup -1} levels, especially in difficult matrices, giving rise to greater reproducibility, lower economic cost and ease of sample pre-treatment compared to other methods. Moreover, the recent introduction of high resolution continuum source Electrothermal atomic absorption spectrometry (HR-CS-ETAAS) has facilitated direct solid sampling, reducing background noise and opening the possibility of achieving even more rapid quantitation of some elements. The incorporation of flow injection analysis (FIA) systems for automation of sample pre-treatment, as well as chemical vapor generation renders (ETAAS) into a feasible option for detection of As and Hg in environmental and food control studies wherein large numbers of samples can be rapidly analyzed. A relatively inexpensive approach with low sample consumption provide additional advantages

  15. Determination of Trace Elements in Nickel Base Alloys by Atomic Absorption Spectrophotometry.

    Science.gov (United States)

    An investigation is described to ascertain whether or not atomic absorption spectrophotometry could be used to determine the concentration of trace ... elements such as silver (Ag), bismuth (Bi), cadmium (Cd), lead (Pb), phosphorus (P), and arsenic (As) in nickel alloys such as Udimet 500 without interference of other constituent elements. (Author)

  16. Determination of Trace Elements in Nickel Base Gas Turbine Parts by Atomic Absorption Spectrophotometry.

    Science.gov (United States)

    An investigation is described to ascertain whether or not atomic absorption spectrophotometry could be used to determine the concentration of trace ... elements such as silver (Ag), bismuth (Bi), cadmium (Cd), and lead (Pb) in nickel base alloys such as IN100, B1900 and 713C, without interference from

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

    Science.gov (United States)

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

    2017-03-01

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

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

    Science.gov (United States)

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

  19. 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)

  20. Rapid accurate analysis of metal (oxide)-on-silica catalysts by atomic absorption spectrometry

    NARCIS (Netherlands)

    Jütte, B.A.H.G.; Heikamp, A.; Agterdenbos, J.

    1979-01-01

    The catalysts, which contain 10–60% copper, chromium, nickel and silicon, are decomposed in sealed Teflon-lined vessels and analyzed by atomic absorption spectrometry. Matrix matching and bracketing standards are applied. The RSD of a single determination is about 1% for all components.

  1. Analysis of Dithiocarbamate Fungicides in Vegetable Matrices Using HPLC-UV Followed by Atomic Absorption Spectrometry.

    Science.gov (United States)

    Al-Alam, Josephine; Bom, Laura; Chbani, Asma; Fajloun, Ziad; Millet, Maurice

    2017-04-01

    A simple method combining ion-pair methylation, high-performance liquid chromatography (HPLC) analysis with detection at 272 nm and atomic absorption spectrometry was developed in order to determine 10 dithiocarbamate fungicides (Dazomet, Metam-sodium, Ferbam, Ziram, Zineb, Maneb, Mancozeb, Metiram, Nabam and Propineb) and distinguish ethylenbisdithiocarbamates (EBDTCs) Zineb, Maneb and Mancozeb in diverse matrices. This method associates reverse phase analysis by HPLC analysis with detection at 272 nm, with atomic absorption spectrometry in order to distinguish, with the same extraction protocol, Maneb, Mancozeb and Zineb. The limits of detection (0.4, 0.8, 0.5, 1.25 and 1.97) and quantification (1.18, 2.5, 1.52, 4.2 and 6.52) calculated in injected nanogram, respectively, for Dazomet, Metam-Na, dimethyldithiocarbamates (DMDTCs), EBDTCs and propylenebisdithiocarbamates (PBDTCs) justify the sensitivity of the method used. The coefficients of determination R2 were 0.9985, 0.9978, 0.9949, 0.988 and 0.9794, respectively, for Dazomet, Metam-Na, DMDTCs, EBDTCs and PBDTCs, and the recovery from fortified apple and leek samples was above 90%. Results obtained with the atomic absorption method in comparison with spectrophotometric analysis focus on the importance of the atomic absorption as a complementary specific method for the distinction between different EBDTCs fungicides. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Chemical modifiers in electrothermal atomic absorption determination of Platinum and Palladium containing preparations in blood serum

    Directory of Open Access Journals (Sweden)

    Аntonina Alemasova

    2012-11-01

    Full Text Available The biological liquids matrixes influence on the characteristic masses and repeatability of Pt and Pd electrothermal atomic absorption spectroscopy (ETAAS determination was studied. The chemical modifiers dimethylglyoxime and ascorbic acid for matrix interferences elimination and ETAAS results repeatability improvement were proposed while bioliquids ETAAS analysis, and their action mechanism was discussed.

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

    Science.gov (United States)

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

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

    Science.gov (United States)

    Weidenhammer, Jeffrey D.

    2007-01-01

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

  5. Negative refraction with absorption suppressed by electromagnetically induced transparency in a left-handed atomic system

    Science.gov (United States)

    Zhao, ShunCai

    2012-02-01

    This paper intends to realize negative refraction with absorption suppressed by the electromagnetically induced transparency (EIT) in a dense four-level atomic system. Without the two equal transition frequencies responding to the probe field, the atomic system displays a negative refraction with the simultaneously negative permittivity and negative permeability (left-handedness). The response of the probe field is amplified and propagates transparency in some frequency extents. Therefore, our aim for searching the low-loss negative refraction can be achieved in the scheme, given the main applied limitation of the negative refractive materials is the large amount of dissipation and absorption. However, an excessive signal field intensity would increase the absorption near the resonance in our scheme.

  6. [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.

  7. High purity polyimide analysis by solid sampling graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Santos, Rafael F.; Carvalho, Gabriel S.; Duarte, Fabio A.; Bolzan, Rodrigo C.; Flores, Erico M. M.

    2017-03-01

    In this work, Cr, Cu, Mn, Na and Ni were determined in high purity polyimides (99.5%) by solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) using Zeeman effect background correction system with variable magnetic field, making possible the simultaneous measurement at high or low sensitivity. The following analytical parameters were evaluated: pyrolysis and atomization temperatures, feasibility of calibration with aqueous solution, linear calibration range, sample mass range and the use of chemical modifier. Calibration with aqueous standard solutions was feasible for all analytes. No under or overestimated results were observed and up to 10 mg sample could be introduced on the platform for the determination of Cr, Cu, Mn, Na and Ni. The relative standard deviation ranged from 3 to 20%. The limits of detection (LODs) achieved using the high sensitivity mode were as low as 7.0, 2.5, 1.7, 17 and 0.12 ng g- 1 for Cr, Cu, Mn, Na and Ni, respectively. No addition of chemical modifier was necessary, except for Mn determination where Pd was required. The accuracy was evaluated by analyte spike and by comparison of the results with those obtained by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry after microwave-assisted digestion in a single reaction chamber system and also by neutron activation analysis. No difference among the results obtained by SS-GFAAS and those obtained by alternative analytical methods using independent techniques. SS-GFAAS method showed some advantages, such as the determination of metallic contaminants in high purity polyimides with practically no sample preparation, very low LODs, calibration with aqueous standards and determination in a wide range of concentration.

  8. Photo- excitation of Cd atom by optogalvanic technique monitoring

    Directory of Open Access Journals (Sweden)

    M. H. Mahdieh

    2004-12-01

    Full Text Available   Optogalavanic technique has been used widely in laser spectroscopy. In this paper we have presented the results of an experimental three- step photo- excitation of Gd atom, using optogalvanic technique. Three tunable dye laser pulses were applied to excite the Gd atom in a three-step photo – excitation process. The optogalvanic signal was used to monitor the laser wavelength and efficiency of the excitation process. The results show that the optogalvanic signal is very sensitive to the first photo- excitation step in comparison with those of the second and the third step.

  9. 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…

  10. Determination of mercury by multisyringe flow injection system with cold-vapor atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Leal, L.O. [Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km.7.5, E-07122 Palma de Mallorca (Spain); Elsholz, O. [Hamburg University of Applied Sciences, Lohbruegger Kirchstrasse 65, 21033 Hamburg (Germany); Forteza, R. [Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km.7.5, E-07122 Palma de Mallorca (Spain); Cerda, V. [Department of Chemistry, University of the Balearic Islands, Carretera de Valldemossa km.7.5, E-07122 Palma de Mallorca (Spain)]. E-mail: victor.cerda@uib.es

    2006-07-28

    A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl{sub 2} in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L{sup -1}. The detection limit (3{sigma} {sub b}/S) achieved is 5 ng L{sup -1}. The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L{sup -1} Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples.

  11. 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.

  12. Highly sensitive fiber grating chemical sensors: An effective alternative to atomic absorption spectroscopy

    Science.gov (United States)

    Laxmeshwar, Lata. S.; Jadhav, Mangesh S.; Akki, Jyoti. F.; Raikar, Prasad; Kumar, Jitendra; prakash, Om; Raikar, U. S.

    2017-06-01

    Accuracy in quantitative determination of trace elements like Zinc, present in drinking water in ppm level, is a big challenge and optical fiber gratings as chemical sensors may provide a promising solution to overcome the same. This paper presents design of two simple chemical sensors based on the principle of shift in characteristic wavelength of gratings with change in their effective refractive index, to measure the concentration of Zinc in drinking water using etched short period grating (FBG) and Long period grating (LPG) respectively. Three samples of drinking water from different places have been examined for presence of Zinc. Further, the results obtained by our sensors have also been verified with the results obtained by a standard method, Atomic absorption spectroscopy (AAS). The whole experiment has been performed by fixing the fibers in a horizontal position with the sensor regions at the center of the fibers, making it less prone to disturbance and breaking. The sensitivity of LPG sensor is about 205 times that of the FBG sensor. A few advantages of Fiber grating sensors, besides their regular features, over AAS have also been discussed, that make our sensors potential alternatives for existing techniques in determination of trace elements in drinking water.

  13. Atomic Structure of Pt3Ni Nanoframe Electrocatalysts by in Situ X-ray Absorption Spectroscopy.

    Science.gov (United States)

    Becknell, Nigel; Kang, Yijin; Chen, Chen; Resasco, Joaquin; Kornienko, Nikolay; Guo, Jinghua; Markovic, Nenad M; Somorjai, Gabor A; Stamenkovic, Vojislav R; Yang, Peidong

    2015-12-23

    Understanding the atomic structure of a catalyst is crucial to exposing the source of its performance characteristics. It is highly unlikely that a catalyst remains the same under reaction conditions when compared to as-synthesized. Hence, the ideal experiment to study the catalyst structure should be performed in situ. Here, we use X-ray absorption spectroscopy (XAS) as an in situ technique to study Pt3Ni nanoframe particles which have been proven to be an excellent electrocatalyst for the oxygen reduction reaction (ORR). The surface characteristics of the nanoframes were probed through electrochemical hydrogen underpotential deposition and carbon monoxide electrooxidation, which showed that nanoframe surfaces with different structure exhibit varying levels of binding strength to adsorbate molecules. It is well-known that Pt-skin formation on Pt-Ni catalysts will enhance ORR activity by weakening the binding energy between the surface and adsorbates. Ex situ and in situ XAS results reveal that nanoframes which bind adsorbates more strongly have a rougher Pt surface caused by insufficient segregation of Pt to the surface and consequent Ni dissolution. In contrast, nanoframes which exhibit extremely high ORR activity simultaneously demonstrate more significant segregation of Pt over Ni-rich subsurface layers, allowing better formation of the critical Pt-skin. This work demonstrates that the high ORR activity of the Pt3Ni hollow nanoframes depends on successful formation of the Pt-skin surface structure.

  14. High-resolution continuum source electrothermal atomic absorption spectrometry - An analytical and diagnostic tool for trace analysis

    Energy Technology Data Exchange (ETDEWEB)

    Welz, Bernhard [Instituto de Quimica, Departamento de Quimica Analitica, Universidade Federal da Bahia, Campus Universitario de Ondina, 40170-290 Salvador - BA (Brazil); Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis - SC (Brazil)], E-mail: w.bernardo@terra.com.br; Borges, Daniel L.G.; Lepri, Fabio G. [Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900 Florianopolis - SC (Brazil); Vale, Maria Goreti R. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil); Heitmann, Uwe [ISAS - Institute for Analytical Sciences, Department of Interface Spectroscopy, Albert-Einstein-Str. 9, 12489 Berlin (Germany)

    2007-09-15

    The literature about applications of high-resolution continuum source atomic absorption spectrometry (HR-CS AAS) with electrothermal atomization is reviewed. The historic development of HR-CS AAS is briefly summarized and the main advantages of this technique, mainly the 'visibility' of the spectral environment around the analytical line at high resolution and the unequaled simultaneous background correction are discussed. Simultaneous multielement CS AAS has been realized only in a very limited number of cases. The direct analysis of solid samples appears to have gained a lot from the special features of HR-CS AAS, and the examples from the literature suggest that calibration can be carried out against aqueous standards. Low-temperature losses of nickel and vanadyl porphyrins could be detected and avoided in the analysis of crude oil due to the superior background correction system. The visibility of the spectral environment around the analytical line revealed that the absorbance signal measured for phosphorus at the 213.6 nm non-resonance line without a modifier is mostly due to the PO molecule, and not to atomic phosphorus. The future possibility to apply high-resolution continuum source molecular absorption for the determination of non-metals is discussed.

  15. A double cell for X-ray absorption spectrometry of atomic Zn

    CERN Document Server

    Mihelic, A; Arcon, I; Padeznik-Gomilsek, J; Borowski, M

    2002-01-01

    A high-temperature cell with a double wall design has been constructed for X-ray absorption spectrometry of metal vapors. The inner cell, assembled from a corundum tube and thin plates without welding or reshaping, serves as a container of the vapor sample. It is not vacuum tight: instead, the outer tube provides inert atmosphere. Several spectra of K-edge atomic absorption of Zn were obtained in the stationary working regime below the Zn boiling point. The K-edge profile shows an extremely strong resonance and, above the continuum threshold, coexcitations of the outer electrons.

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

    Science.gov (United States)

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

    2016-12-01

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

  17. Graphite Furnace Atomic Absorption Spectrometric Determination of Bismuth(III) after Coprecipitation with Hafnium Hydroxide

    OpenAIRE

    Ueda, Joichi; Takagi, Midori

    1990-01-01

    A method for the coprecipitation of bismuth(III) with hafnium hydroxide followed by a graphite-furnace atomic absorption spectrometric determination is described. Hafnium hydroxide coprecipitates quantitatively 0.05–3 μg of bismuth(III) from 50–400 cm3 of sample solution at pH 5.8–11.2. The presence of 2.5–50 mg of hafnium in 25 cm3 does not affect the atomic absorbance of bismuth(III). The calibration curve is linear for 0.05–3 μg of bismuth(III) in 25 cm3 and passes through the origin. Inte...

  18. Proposal for efficient two-dimensional atom localization using probe absorption in a microwave-driven four-level atomic system

    Energy Technology Data Exchange (ETDEWEB)

    Ding Chunling; Li Jiahua; Yang Xiaoxue; Xiong Hao [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhang Duo [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Department of Mathematics and Physics, Wuhan Polytechnic University, Wuhan 430023 (China)

    2011-10-15

    The behavior of two-dimensional (2D) atom localization is explored by monitoring the probe absorption in a microwave-driven four-level atomic medium under the action of two orthogonal standing-wave fields. Because of the position-dependent atom-field interaction, the information about the position of the atom can be obtained via the absorption measurement of the weak probe field. It is found that the localization behavior is significantly improved due to the joint quantum interference induced by the standing-wave and microwave-driven fields. Most importantly, the atom can be localized at a particular position and the maximal probability of finding the atom in one period of the standing-wave fields reaches unity by properly adjusting the system parameters. The proposed scheme may provide a promising way to achieve high-precision and high-resolution 2D atom localization.

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

    Science.gov (United States)

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

    2015-12-01

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

  20. Cadmium determination in urine by atomic absorption spectrometry as a screening test in industrial medicine

    Science.gov (United States)

    Lehnert, G.; Klavis, G.; Schaller, K. H.; Haas, T.

    1969-01-01

    Lehnert, G., Klavis, G., Schaller, K. H., and Haas, T. (1969).Brit. J. industr. Med.,26, 156-158. Cadmium determination in urine by atomic absorption spectrometry as a screening test in industrial medicine. Cadmium was determined by atomic absorption spectrometry in the urine and serum of 18 workers exposed to cadmium dust and fume in a zinc smelting plant. In all cases the concentrations of cadmium in the serum were within the normal range, but those in the urine were elevated. The elevated urine concentrations showed that the exposed group had taken up more cadmium than normal, although they showed no clinical symptoms of cadmium poisoning. Analysis of urine for cadmium is therefore of value in preventive medicine, and should be used for periodic check-ups on those occupationally exposed. PMID:5780108

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

    Science.gov (United States)

    Küçükbay, F Zehra; Kuyumcu, Ebru

    2014-09-01

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

  2. Determination of total selenium in pharmaceutical and herbal supplements by hydride generation and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Kazi, Tasneem G; Kolachi, Nida F; Afridi, Hassan I; Brahman, Kapil Dev; Shah, Faheem

    2014-01-01

    The total selenium (Se) was determined in herbal and pharmaceutical supplements used for liver diseases. The total Se contents were determined in different pharmaceutical and herbal supplements by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after microwave-assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material and the standard addition method. The recoveries of total Se were 99.4 and 99.0% for HGAAS and GFAAS, respectively. The precision of the techniques expressed as RSD were 2.34 and 4.54% for HGAAS and GFAAS measurements, respectively. The LOD values for HGAAS and GFAAS were 0.025 and 0.052 pglg, respectively. The concentrations of Se in pharmaceutical and herbal supplements were found in the range of 19.2-53.8 and 25.0-42.5 pg/g, respectively, corresponding to 35-76% and 45-76% of the total recommended dose of Se for adults.

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

    Science.gov (United States)

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

  4. Three axis vector atomic magnetometer utilizing polarimetric technique

    Energy Technology Data Exchange (ETDEWEB)

    Pradhan, Swarupananda, E-mail: spradhan@barc.gov.in, E-mail: pradhans75@gmail.com [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India and Homi Bhabha National Institute, Department of Atomic Energy, Mumbai 400094 (India)

    2016-09-15

    The three axis vector magnetic field measurement based on the interaction of a single elliptically polarized light beam with an atomic system is described. The magnetic field direction dependent atomic responses are extracted by the polarimetric detection in combination with laser frequency modulation and magnetic field modulation techniques. The magnetometer geometry offers additional critical requirements like compact size and large dynamic range for space application. Further, the three axis magnetic field is measured using only the reflected signal (one polarization component) from the polarimeter and thus can be easily expanded to make spatial array of detectors and/or high sensitivity field gradient measurement as required for biomedical application.

  5. [Determination of lead by atomic absorption spectrophotometry with regard to toxicology research].

    Science.gov (United States)

    Oudart, N; Guichard, C; Delage, C

    1976-01-01

    The toxicity of lead in the human environment is acquiring a growing interest which lead us to choose a quick, precise, sensitive and specific method able to perform number of measurements. Thanks to the survey consisting in a dosage of lead by atomic-absorption spectrometric, we are able to confirm the advantages and superiority of such a method and to employ it for the toxicologic research of lead in food, water, industrial atmosphere, and biological liquids.

  6. Determination of traces of silicone defoamer in fruit juices by solvent extraction/atomic absorption spectroscopy.

    Science.gov (United States)

    Gooch, E G

    1993-01-01

    Silicone defoamers are used to control foam during the processing of fruit juices. Residual silicones in fruit juices can be separated from the naturally occurring siliceous materials in fruit products and selectively recovered by solvent extraction, after suitable pretreatment. The recovered silicone is measured by atomic absorption spectroscopy. Silicone concentrations as low as about 1 ppm can be measured. The juices are accurately spiked for recovery studies by the addition of silicone dispersed in D-sorbitol.

  7. DETERMINATION OF NICKLE CONTENTS IN SELECTED VANASPATI GHEE THROUGH ATOMIC ABSORPTION SPECTROPHOTOMETER

    OpenAIRE

    Waqas Ahmad; Hameed Ur Rehman; Muhammad Aamir; Maria Urooj; Nayyar Hafiz; Zubia Masood; Mohib Ullah; Ijaz Ahmad

    2014-01-01

    To convert vegetable edible oils into vanaspati ghee, nickel is used as a catalyst in the hydrogenation process. A simple and fast method for the trace level determination of nickel in ghee is reported. In this different methods were applied for the extraction of residual nickel from ghee samples. Using toluene, as organic solvents, an acid mixture was used for the extraction of nickel. Extracted nickel was quantified with atomic absorption. Among the organic solvents, toluene proved to be th...

  8. 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.

  9. Comparison of two methods for blood lead analysis in cattle: graphite-furnace atomic absorption spectrometry and LeadCare(R) II system.

    Science.gov (United States)

    Bischoff, Karyn; Gaskill, Cynthia; Erb, Hollis N; Ebel, Joseph G; Hillebrandt, Joseph

    2010-09-01

    The current study compared the LeadCare(R) II test kit system with graphite-furnace atomic absorption spectrometry for blood lead (Pb) analysis in 56 cattle accidentally exposed to Pb in the field. Blood Pb concentrations were determined by LeadCare II within 4 hr of collection and after 72 hr of refrigeration. Blood Pb concentrations were determined by atomic absorption spectrometry, and samples that were coagulated (n = 12) were homogenized before analysis. There was strong rank correlation (R(2) = 0.96) between atomic absorption and LeadCare II (within 4 hr of collection), and a conversion formula was determined for values within the observed range (3-91 mcg/dl, although few had values >40 mcg/dl). Median and mean blood pb concentrations for atomic absorption were 7.7 and 15.9 mcg/dl, respectively; for LeadCare II, medians were 5.2 mcg/dl at 4 hr and 4.9 mcg/dl at 72 hr, and means were 12.4 and 11.7, respectively. LeadCare II results at 4 hr strongly correlated with 72 hr results (R(2) = 0.96), but results at 72 hr were lower (P atomic absorption. Although there have been several articles that compared LeadCare with other analytical techniques, all were for the original system, not LeadCare II. The present study indicated that LeadCare II results correlated well with atomic absorption over a wide range of blood Pb concentrations and that refrigerating samples for up to 72 hr before LeadCare II analysis was acceptable for clinical purposes.

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

    Science.gov (United States)

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

    2013-07-10

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

  11. Some problems connected with boron determination by atomic absorption spectroscopy and the sensitivity improvement

    Directory of Open Access Journals (Sweden)

    JELENA J. SAVOVIC

    2001-08-01

    Full Text Available Two atomizers were compared: an N2O–C2H2 flame and a stabilized U-shaped DC arc with aerosol supply. Both the high plasma temperature and the reducing atmosphere obtained by acetylene addition to the argon stream substantially increase the sensitivity of boron determination by atomic absorption spectroscopy (AAS when the arc atomizer is used. The results were compared with those for silicon as a control element. The experimental characteristic concentrations for both elements were compared with the computed values. The experimentally obtained characteristic concentration for boron when using the arc atomizer was in better agreement with the calculated value. It was estimated that the influence of stable monoxide formation on the sensitivity for both elements was about the same, but reduction of analyte and formation of non-volatile carbide particles was more important for boron, which is the main reason for the low sensitivity of boron determination using a flame atomizer. The use of an arc atomizer suppresses this interference and significantly improves the sensitivity of the determination.

  12. Determination of trace elements in paints by direct sampling graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bentlin, Fabrina R.S. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil); Pozebon, Dirce [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, UFRGS, 91501-970 Porto Alegre, RS (Brazil)], E-mail: dircepoz@iq.ufrgs.br; Mello, Paola A.; Flores, Erico M.M. [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900 Santa Maria, RS (Brazil)

    2007-10-17

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO{sub 3}){sub 2} was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 {mu}g g{sup -1} of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

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

    Science.gov (United States)

    Ladhaf, Bibifatima M.; Pawar, Pravina P.

    2015-04-01

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

  14. Handbook of theoretical atomic physics data for photon absorption, electron scattering, and vacancies decay

    CERN Document Server

    Amusia, Miron Ya; Yarzhemsky, Victor

    2012-01-01

    The aim of this book is to present highly accurate and extensive theoretical Atomic data and to give a survey of selected calculational methods for atomic physics, used to obtain these data. The book presents the results of calculations of cross sections and probabilities of a broad variety of atomic processes with participation of photons and electrons, namely on photoabsorption, electron scattering and accompanying effects. Included are data for photoabsorption and electron scattering cross-sections and probabilities of vacancy decay formed for a large number of atoms and ions. Attention is also given to photoionization and vacancy decay in endohedrals and to positron-atom scattering. The book is richly illustrated. The methods used are one-electron Hartree-Fock and the technique of Feynman diagrams that permits to include many-electron correlations. This is done in the frames of the Random Phase approximation with exchange and the many-body perturbation theory. Newly obtained and previously collected atomi...

  15. Resonance enhancement of two photon absorption by magnetically trapped atoms in strong rf-fields

    Science.gov (United States)

    Chakraborty, A.; Mishra, S. R.

    2018-01-01

    Applying a many mode Floquet formalism for magnetically trapped atoms interacting with a polychromatic rf-field, we predict a large two photon transition probability in the atomic system of cold 87Rb atoms. The physical origin of this enormous increase in the two photon transition probability is due to the formation of avoided crossings between eigen-energy levels originating from different Floquet sub-manifolds and redistribution of population in the resonant intermediate levels to give rise to the resonance enhancement effect. Other exquisite features of the studied atom-field composite system include the splitting of the generated avoided crossings at the strong field strength limit and a periodic variation of the single and two photon transition probabilities with the mode separation frequency of the polychromatic rf-field. This work can find applications to characterize properties of cold atom clouds in the magnetic traps using rf-spectroscopy techniques.

  16. 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

  17. PRECONCENTRATION OF CADMIUM USING AMBERLITE XAD-4 PRIOR TO ATOMIC ABSORPTION SPECTROMETERY

    Directory of Open Access Journals (Sweden)

    S. J. Shahtaheri, M. Khadem, F. Golbabaei, A. Rahimi Froushani

    2006-01-01

    Full Text Available Cadmium is an important environmental constituent widely used in industrial processes for production of synthetic materials and therefore can be released in the environment causing public exposure especially around the industrial residence area. For evaluation of human exposure to trace toxic metal of Cd (II, environmental and biological monitoring are essential processes, in which, preparation of such samples is one of the most time-consuming and error-prone aspects prior to analysis. The use of solid-phase extraction (SPE has grown and is a fertile technique of sample preparation as it provides better results than those produced by liquid-liquid extraction (LLE. To evaluate factors influencing quantitative analysis scheme of cadmium in water samples, solid phase extraction using mini columns filled with XAD-4 resin was optimized with regard to sample pH, ligand concentration, loading flow rate, elution solvent, sample volume (up to 500 ml, elution volume, amount of resins, and sample matrix interferences. Cadmium was retained on solid sorbent and eluted followed by simple determination of analytes by using flame atomic absorption spectrometery. Obtained recoveries of the metal ion were more than 92%. The amount of the analyte detected after simultaneous preconcentration was basically in agreement with the added amounts. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. The developed method promised to be applicable for evaluation of other metal ions present in different environmental and occupational samples as suitable results were obtained for relative standard deviation (less than 10%; therefore, it is concluded that, this optimized method can be considered to be successful in simplifying sample preparation for trace residue analysis of Cd in different matrices for evaluation of occupational and

  18. High-precision three-dimensional atom localization via phase-sensitive absorption spectra in a four-level atomic system

    Science.gov (United States)

    Zhang, Duo; Yu, Rong; Sun, Zhaoyu; Ding, Chunling; Zubairy, M. Suhail

    2018-01-01

    We propose a new scheme for highly efficient three-dimensional (3D) atom localization in a coherently driven closed-loop four-level atomic system via measuring the probe absorption of the weak field. Due to the spatially dependent atom–field interaction, the absorption spectra of the weak probe laser field carry the information about the atomic position. By solving the density-matrix equations of motion and properly modulating the system parameters such as the probe detuning, the relative phase of three driving fields, and the intensity of the control and microwave fields, we can realize high-precision and high-resolution 3D atom localization. Furthermore, we can find the atom at a certain position with 100% probability under appropriate conditions, and then we employ the dressed-state analysis to explain qualitatively the reason of high-precision 3D atom localization.

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

    Science.gov (United States)

    Katskov, Dmitri

    2015-03-01

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

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

    Science.gov (United States)

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

  1. Atomic Data Revisions for Improving Absorption Line Studies of the Interstellar, Circumgalactic, and Intergalactic Medium

    Science.gov (United States)

    Cashman, Frances; Kulkarni, Varsha; Kisielius, Romas; Ferland, Gary; Bogdanovich, Pavel

    2018-01-01

    Surveying and studying galaxies at different epochs is essential to understanding how galaxies evolve. Atomic spectroscopy is used to study the gas in and around galaxies by means of the absorption features in the spectra of background quasars. Element abundances derived from the measurement of observed lines in these quasar absorption systems rely on accurate atomic data such as the oscillator strength of electric dipole transitions. We have produced a compilation of recommended oscillator strengths for 576 key transitions for wavelengths longward of 911.753 Angstroms (the H I Lyman limit). This compilation focuses on the recent findings from numerous theoretical and experimental physicists for ions of astrophysical interest that have been observed in the interstellar medium (ISM), the circumgalactic medium (CGM), and the intergalactic medium (IGM), for selected elements ranging from C to Pb. Differences between the former and the newly recommended values are greater than 25% for approximately 22% of lines with updated oscillator strength values. We encourage future absorption line studies of the ISM, CGM, and IGM medium to use this compilation.This work was supported in part by NSF-AST/1108830, NASA/STScI support for HST GO-12536, and a NASA/SC Space Grant graduate fellowship.

  2. Observation of spontaneously generated coherence on absorption in rubidium atomic beam

    Science.gov (United States)

    Tian, Si-Cong; Kang, Zhi-Hui; Wang, Chun-Liang; Wan, Ren-Gang; Kou, Jun; Zhang, Hang; Jiang, Yun; Cui, Hai-Ning; Gao, Jin-Yue

    2012-02-01

    We report the experimental observation of the effect of spontaneously generated coherence on absorption without the rigorous requirement of close-lying levels. The experiments are studied in both a four-level N-type and a four-level inverted-Y-type atomic system in a rubidium atomic beam. With the coupling and controlling field, the N-type system is equivalent to a system with three closely upper levels coupled to one lower level by the same vacuum modes. The quantum interference can induce two prominent and nearly transparent holes where the slope of the refractive index is very steep. This special situation could allow the simultaneous propagation of two weak pulses with different frequencies. When we tune the wavelength of the controlling field, the N-type system turns to be the inverted-Y atomic system. Under the two-photon resonance condition, the system is equivalent to a V-type system with two closely upper levels, and the interference can reduce one broad transparency window in the middle of the absorption spectrum. Besides we can control the number of the spontaneously decay channels by the detuning of the controlling field, thus the effect of spontaneously generated coherence can exist in three or two closely space levels.

  3. 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.

  4. Arsenic in marine tissues — The challenging problems to electrothermal and hydride generation atomic absorption spectrometry

    Science.gov (United States)

    Karadjova, Irina B.; Petrov, Panayot K.; Serafimovski, Ivan; Stafilov, Trajče; Tsalev, Dimiter L.

    2007-03-01

    Analytical problems in determination of arsenic in marine tissues are addressed. Procedures for the determination of total As in solubilized or extracted tissues with tetramethylammonium hydroxide and methanol have been elaborated. Several typical lyophilized tissues were used: NIST SRM 1566a 'Oyster Tissue', BCR-60 CRM 'Trace Elements in an Aquatic Plant ( Lagarosiphon major)', BCR-627 'Forms of As in Tuna Fish Tissue', IAEA-140/TM 'Sea Plant Homogenate', NRCC DOLT-1 'Dogfish Liver' and two representatives of the Black Sea biota, Mediterranean mussel ( Mytilus galloprovincialis) and Brown algae ( Cystoseira barbata). Tissues (nominal 0.3 g) were extracted in tetramethylammonium hydroxide (TMAH) 1 ml of 25% m/v TMAH and 2 ml of water) or 5 ml of aqueous 80% v/v methanol (MeOH) in closed vessels in a microwave oven at 50 °C for 30 min. Arsenic in solubilized or extracted tissues was determined by electrothermal atomic absorption spectrometry (ETAAS) after appropriate dilution (nominally to 25 ml, with further dilution as required) under optimal instrumental parameters (pyrolysis temperature 900 °C and atomization temperature 2100 °C) with 1.5 μg Pd as modifier on Zr-Ir treated platform. Platforms have been pre-treated with 2.7 μmol of zirconium and then with 0.10 μmol of iridium which served as a permanent chemical modifier in direct ETAAS measurements and as an efficient hydride sequestration medium in flow injection hydride generation (FI-HG)-ETAAS. TMAH and methanol extract 96-108% and 51-100% of As from CRMs. Various calibration approaches have been considered and critically evaluated. The effect of species-dependent slope of calibration graph or standard additions plot for total As determination in a sample comprising of several individual As species with different ETAAS behavior has been considered as a kind of 'intrinsic element speciation interference' that cannot be completely overcome by standard additions technique. Calibration by means of CRMs has

  5. Determination of cobalt in human biological liquids from electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Dragan, Felicia; Hîncu, Lucian; Bratu, Ioan

    2009-08-01

    Problems and possibilities of the determination of Co in serum and urine samples by electrothermal atomic absorption spectrometry (ETAAS) are described. Optimal instrumental parameters as well as a suitable atomizer, calibration procedure and hydrogen peroxide as modifier are proposed for direct ETAAS measurement of Co in serum and urine. The detection limit achieved was 0.1 μg L-1 for both matrices and relative standard deviations varied in the range 5-20% depending on the Co concentration in the sample. The validity of the method was verified by the analyses of standard reference materials. For serum samples with Co content lower than the detection limit, a separation and preconcentration procedure based on liquid/liquid extraction is suggested prior to determination of Co in the organic phase by ETAAS. This procedure permits determination of 0.02 μg L-1 Co in serum samples with a relative standard deviation of 10-18%.

  6. Determination of vanadium in mussels by electrothermal atomic absorption spectrometry without chemical modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Saavedra, Y.; Fernandez, P. [Centro de Control do Medio Marino, Peirao de Vilaxoan s/n, Vilagarcia de Arousa, 36611 Pontevedra (Spain); Gonzalez, A. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Quimica, 15706, Santiago de Compostela (Spain)

    2004-05-01

    A method was developed for the quantitative determination of total vanadium concentration in mussels via electrothermal atomic absorption spectrometry (ETAAS). After the microwave digestion of the samples, a program using temperatures of 1600 C and 2600 C for ashing and atomization respectively, without any matrix modifiers, allowed us to obtain results that were satisfactory since they agreed closely with certified reference material values. The detection limit was 0.03 mg kg{sup -1} (dry weight), indicating that the method is suitable for the analysis of mussel samples. This determination was compared with matrix modifiers that have been reported previously. The method was applied to various cultivated and wild mussels from the Galician coast, yielding levels below 1 mg kg{sup -1} (wet weight). (orig.)

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

    Science.gov (United States)

    1977-01-01

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

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

    Science.gov (United States)

    Welty, Daniel E.

    1990-01-01

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

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

    Science.gov (United States)

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

    1969-01-01

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

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

    Science.gov (United States)

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

    2006-05-01

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

  11. Atomic-level molybdenum oxide nanorings with full-spectrum absorption and photoresponsive properties.

    Science.gov (United States)

    Yang, Yong; Yang, Yang; Chen, Shuangming; Lu, Qichen; Song, Li; Wei, Yen; Wang, Xun

    2017-11-16

    Superthin nanostructures, particularly with atomic-level thicknesses, typically display unique optical properties because of their exceptional light-matter interactions. Here, we report a facile strategy for the synthesis of sulfur-doped molybdenum oxide nanorings with an atomic-level size (thickness of 0.5 nm) and a tunable ring-in-ring architecture. These atomic-level nanorings displayed strong photo-absorption in both the visible and infrared-light ranges and acted as a photothermal agent. Under irradiation with an 808 nm laser with an intensity of 1 W/cm2, a composite of the nanorings embedded in polydimethylsiloxane showed an ultrafast photothermal effect, delivering a local temperature of up to 400 °C within 20 s, which to the best of our knowledge is the highest temperature by light irradiation reported to date. Meanwhile, the resulting nanorings were also employed as a photoinitiator to remotely induce a visible-light shape memory response, self-healing, reshaping performance and reversible actuation of dynamic three-dimensional structures. This study demonstrates an advancement towards controlling atomic-level-sized nanostructures and achieving greatly enhanced optical performances for optoelectronics.

  12. Development of a 2D temperature measurement technique for combustion diagnostics using 2-line atomic fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Johan

    2001-01-01

    The present thesis is concerned with the development and application of a novel planar laser-induced fluorescence (PLIF) technique for temperature measurements in a variety of combusting flows. Accurate measurement of temperature is an essential task in combustion diagnostics, since temperature is one of the most fundamental quantities for the characterization of combustion processes. The technique is based on two-line atomic fluorescence (TLAF) from small quantities of atomic indium (In) seeded into the fuel. It has been developed from small-scale experiments in laboratory flames to the point where practical combustion systems can be studied. The technique is conceptually simple and reveals temperature information in the post-flame regions. The viability of the technique has been tested in three extreme measurement situations: in spark ignition engine combustion, in ultra-lean combustion situations such as lean burning aero-engine concepts and, finally, in fuel-rich combustion. TLAF was successfully applied in an optical Sl engine using isooctane as fuel. The wide temperature sensitivity, 700 - 3000 K, of the technique using indium atoms allowed measurements over the entire combustion cycle in the engine to be performed. In applications in lean combustion a potential problem caused by the strong oxidation processes of indium atoms was encountered. This limits measurement times due to deposits of absorbing indium oxide on measurement windows. The seeding requirement is a disadvantage of the technique and can be a limitation in some applications. The results from experiments performed in sooting flames are very promising for thermometry measurements in such environments. Absorption by hydrocarbons and other native species was found to be negligible. Since low laser energies and low seeding concentrations could be used, the technique did not, unlike most other incoherent optical thermometry techniques, suffer interferences from LII of soot particles or LIF from PAH

  13. Structure of Nanocrystals by the atomic Pair Distribution Function technique

    Science.gov (United States)

    Petkov, Valeri

    2003-03-01

    Knowledge of the atomic-scale structure is an important prerequisite to understand and predict the properties of materials. In the case of crystals it is obtained from the positions and intensities of the Bragg peaks in the diffraction data. Materials constructed at the nanoscale, however, lack the long-range order and symmetry of perfect crystals. The result is that the diffraction patterns of nanocrystals are much more diffuse with few if any Bragg peaks. This poses a real challenge to the traditional techniques for structure determination. The challenge can be met by employing the so-called atomic Pair Distribution Function (PDF) technique. The basics of the PDF technique will be outlined and it advantages illustrated with results from recent studies of nanocrystalline WS_2, LiMoS_2, V_2O_5.nH_2O, GdAl2 nanomagnets, nanoporous silicates and Cs doped zeolites. Acknowledgements: Thanks are due to M. Kanatzidis, T. Pinnavaia, T. Vogt, S. Shastri, S.J.L. Billinge, D. Leslie-Pelecky and J. Dye for providing the samples and help with the experiments.

  14. Determination of total arsenic in fish by hydride-generation atomic absorption spectrometry: method validation, traceability and uncertainty evaluation

    Science.gov (United States)

    Nugraha, W. C.; Elishian, C.; Ketrin, R.

    2017-03-01

    Fish containing arsenic compound is one of the important indicators of arsenic contamination in water monitoring. The high level of arsenic in fish is due to absorption through food chain and accumulated in their habitat. Hydride generation (HG) coupled with atomic absorption spectrometric (AAS) detection is one of the most popular techniques employed for arsenic determination in a variety of matrices including fish. This study aimed to develop a method for the determination of total arsenic in fish by HG-AAS. The method for sample preparation from American of Analytical Chemistry (AOAC) Method 999.10-2005 was adopted for acid digestion using microwave digestion system and AOAC Method 986.15 - 2005 for dry ashing. The method was developed and validated using Certified Reference Material DORM 3 Fish Protein for trace metals for ensuring the accuracy and the traceability of the results. The sources of uncertainty of the method were also evaluated. By using the method, it was found that the total arsenic concentration in the fish was 45.6 ± 1.22 mg.Kg-1 with a coverage factor of equal to 2 at 95% of confidence level. Evaluation of uncertainty was highly influenced by the calibration curve. This result was also traceable to International Standard System through analysis of Certified Reference Material DORM 3 with 97.5% of recovery. In summary, it showed that method of preparation and HG-AAS technique for total arsenic determination in fish were valid and reliable.

  15. Determination of silver, bismuth, cadmium, copper, lead, and zinc in geologic materials by atomic absorption spectrometry with tricaprylylmethylammonium chloride

    Science.gov (United States)

    Viets, J.G.

    1978-01-01

    Interferences commonly encountered in the determination of silver, bismuth, cadmium, copper, lead, and zinc at crustal abundance levels are effectively eliminated using a rapid, sensitive, organic extraction technique. A potassium chlorate-hydrochloric acid digestion solubilizes the metals not tightly bound in the silicate lattice of rocks, soils, and stream sediments. The six metals are selectively extracted into a 10% Aliquat 336-MIBK organic phase in the presence of ascorbic acid and potassium iodide. Metals in the organic extract are determined by flame atomic absorption spectrometry to the 0.02-ppm level for silver, cadmium, copper, and zinc and to the 0.2-ppm level for bismuth and lead with a maximum relative standard deviation of 18.8% for known reference samples. An additional hydrofluoric acid digestion may be used to determine metals substituted in the silicate lattice.

  16. [Determination of trace lead in water and milk tea powder samples with organic coprecipitation-flame atomic absorption spectrometric].

    Science.gov (United States)

    Lin, Jian-Mei; Yao, Jun-Xue; Zhao, Wen-Yan

    2013-05-01

    A method was proposed for the determination of trace lead with flame atomic absorption spectrometry after preconcentration of lead by rapid coprecipitation technique with PAR-Fe (III) at pH 6.0. The analytical parameters including pH, amount of iron (III), amount of reagent, the standing time of the precipitate, etc., were examined. The detection limits (DL) were found to be 18.7 microg x L(-1) for Pb (II). In analysis of lake water and the milk tea powder samples, RSD's and the standard addition recovery of this method were in the ranges of 1.03%-2.24% and 94.2%-98.3% respectively. The effect of matrix can be overcome by the method and the results are satisfyiog. The method shows good application prospect in the determination of trace lead owing to its rapidness and reproducibility.

  17. [Speciation analysis of trace elements Cu, Fe and Zn in serum by flame atomic absorption spectrophotometry].

    Science.gov (United States)

    Hu, Jun; Chang, Yao-Ming; Gao, Shuang-Bin; Hai, Chun-Xu; Li, Jin-Sheng; Xie, Xiao-Ping

    2008-03-01

    Since biological functions of the elements are generally different, depending on their chemical forms, chemical speciation analysis is really important in metallomics research. Thus, multielement analysis and chemical speciation of the elements in serum were carried out in the present work. A hyphenated technique was developed for high-throughput speciation analysis of the copper, iron and zinc in serum by molecular biology technology and flame atomic absorption spectrophotometry (AAS). Here, Cu, Fe and Zn in serum were classifyied as the forms of combination and non-combination. The serum protein was precipitated by 60% concentration of ethanol under hypothermy. The forms of combination of Cu, Fe and Zn in serum which combined with proteins were in precipitations, and the forms of non-combination of Cu, Fe and Zn in serum, which were free ions, were in supernatant. The total amount of Cu, Fe and Zn in serum and the amount of the forms of non-combination of Cu, Fe and Zn were analyzed by AAS. The amount of the forms of combination of Cu, Fe and Zn was obtained by calculation. The detection limit of Cu in serum by the method is around and 9.84 x 10(-3) microg x mL(-1). For Fe and Zn, the detection limit is about 2.76 x 10(-2) microg x mL(-1) and 1.06 x 10(-3) microg x mL(-1), respectively. The percentage recovery of trace elements Cu, Fe and Zn by the proposed procedure is in the range 95.0%-101.0%, 95.0%-102.0% and 95.0%-103.0%, respectively. The relative standard deviation (RSD) of trace elements Cu, Fe and Zn in the serum is in the range 1.88%-2.26%, 0.56%-1.59% and 0.34%-1.36%, respectively. Speciation of trace elements Cu, Fe and Zn in the serum of SD rat were analyzed by the method.

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

    Science.gov (United States)

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

    2016-08-01

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

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

    Science.gov (United States)

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

    2015-08-01

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

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

    Science.gov (United States)

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

    2005-01-01

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

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

    Science.gov (United States)

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

    1982-01-01

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

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

    Science.gov (United States)

    Chen, Li-dan; Chen, Kai-kao

    2012-01-01

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

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

    Science.gov (United States)

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

    2009-07-01

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

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

    Science.gov (United States)

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

    2015-10-10

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

  5. Laser induced deflection technique for absolute thin film absorption measurement: optimized concepts and experimental results.

    Science.gov (United States)

    Mühlig, Christian; Kufert, Siegfried; Bublitz, Simon; Speck, Uwe

    2011-03-20

    Using experimental results and numerical simulations, two measuring concepts of the laser induced deflection (LID) technique are introduced and optimized for absolute thin film absorption measurements from deep ultraviolet to IR wavelengths. For transparent optical coatings, a particular probe beam deflection direction allows the absorption measurement with virtually no influence of the substrate absorption, yielding improved accuracy compared to the common techniques of separating bulk and coating absorption. For high-reflection coatings, where substrate absorption contributions are negligible, a different probe beam deflection is chosen to achieve a better signal-to-noise ratio. Various experimental results for the two different measurement concepts are presented.

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

    Science.gov (United States)

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

    2002-04-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  8. Satellite and rocket-borne atomic oxygen sensor techniques

    Science.gov (United States)

    Osborne, J. J.; Harris, I. L.; Roberts, G. T.; Chambers, A. R.

    2001-11-01

    Neutral atomic oxygen (AO)—the dominant atmospheric species at typical low Earth orbit altitudes—is responsible for the erosion, or other degradation, of many satellite materials. Therefore, AO has become an important consideration for spacecraft designers and manufacturers. The study of AO is also of interest to atmospheric physicists because it is involved in many of the chemical reactions occurring naturally in the mesosphere and lower thermosphere. Both these groups rely on atmospheric models for computer-based simulation and prediction of atomic oxygen concentrations. Such models require, or are enhanced by, empirical input data—that is, actual measurements of AO number densities. A review is presented of the different measurement techniques that, to date, have been used on satellites and sounding rockets to perform AO studies. Rather than reporting results from every sensor application, this article takes a more general view of the experimental methods, using example devices to highlight their advantages and disadvantages. New or promising equipment, or techniques that could be exploited for performing such measurements, are also described. We attempt some semiquantitative comparison of the techniques, although the most appropriate experimental method for any given flight opportunity depends heavily on the mission conditions and science goals. Our emphasis is on missions where the available mass and power are limited. In these situations the most suitable established device is probably that of the thin film actinometer. If more risk can be assumed then a more promising, but as yet unqualified, method is that of the fiber-optic reflectance sensor. However, since both these devices are nonreusable, it is shown that semiconducting sensors may be better for long duration, mass- and power-limited applications.

  9. Enhanced Photocathodes for Astrophysics using Atomic Layer Deposition Techniques Deposition Techniques

    Science.gov (United States)

    Siegmund, Oswald

    The objective of this program is to exploit the recent availability of atomic layer deposition techniques to provide a new generation of high performance photocathodes. We intend to work on the enhancement of photocathodes by atomic layer deposition, and on atomic layer deposited substrate structures, and assess their performance (gain, lifetime, stability, image fidelity) in microchannel plate based detectors. This would enable detection efficiency and bandpass improvements for microchannel plate based spaceflight detectors for imaging and spectroscopic instruments in small and large formats. Applications include the detection of soft X-ray, and UV through NUV. Recent work has achieved considerable success in development of borosilicate substrate microchannel plates functionalized by atomic layer deposited resistive and photoemissive materials. These could provide stable, compatible, substrates for high efficiency photocathodes, although very limited work has been done to date on this aspect. This development addresses detector technologies for SALSO, and impending proposals for a number of other NASA sub-orbital and satellite instruments. Results with borosilicate substrate microchannel plates functionalized by atomic layer deposited surface layers has been impressive, providing economical devices with long term stable gain and low background in formats up to 20 cm. Atomic layer deposition provides a surface layer that is smooth, clean, and chemically compatible with photocathode materials, and withstands high temperatures. The substrates can also be made with larger open area ratios, and the atomic layer deposition nanofabrication processes provides high secondary emission coefficients that will enhance photocathode efficiencies. Photocathodes (GaN, etc) deposited by MOCVD or MBE processes may also be deposited using atomic layer deposition, with potential advantages in layer structuring and selective area coverage and penetration over large areas.

  10. Measurement of the absorption coefficient using the sound-intensity technique

    Science.gov (United States)

    Atwal, M.; Bernhard, R.

    1984-01-01

    The possibility of using the sound intensity technique to measure the absorption coefficient of a material is investigated. This technique measures the absorption coefficient by measuring the intensity incident on the sample and the net intensity reflected by the sample. Results obtained by this technique are compared with the standard techniques of measuring the change in the reverberation time and the standing wave ratio in a tube, thereby, calculating the random incident and the normal incident adsorption coefficient.

  11. Determination of vanadium in soils and sediments by the slurry sampling graphite furnace atomic absorption spectrometry using permanent modifiers.

    Science.gov (United States)

    Dobrowolski, Ryszard; Adamczyk, Agnieszka; Otto, Magdalena

    2013-09-15

    A new analytical procedure for vanadium (V) determination in soils and sediments by the slurry sampling graphite furnace atomic absorption spectrometry (slurry sampling GFAAS) using the mixed permanent modifiers is described. Moreover, the comparison of action of the modifiers based on the iridium (Ir) and carbide-forming elements: tungsten (W) and niobium (Nb) deposited on the graphite tubes is studied, especially in terms of their analytical utility and determination sensitivity. The mechanism of their action was investigated using an X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray detector (EDX). Finally, the mixture of 0.3 μg of Ir and 0.04 μg of Nb was used for the graphite tube permanent modification. The analytical procedure was optimized on the basis of the data from pyrolysis and atomization temperature curves studies. The results obtained for the four certified reference materials (marine sediments: PACS-1 and MESS-1, lake sediment: SL-1, soil: San Joaquin Soil SRM 2709), using the slurry sampling GFAAS and the standard calibration method, were in good agreement with the certified values. The detection and quantification limits and characteristic mass calculated for the proposed procedure were 0.04 µg/g, 0.16 µg/g and 11.9 pg, respectively. The precision (RSD% less than 8%) and the accuracy of vanadium determination in the soil and sediment samples were acceptable. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Preconcentration and determination of ultra-traces of platinum in human serum using the combined electrodeposition-electrothermal atomic absorption spectroscopy (ED-ETAAS) and chemometric method.

    Science.gov (United States)

    Najafi, Nahid Mashkouri; Shahparvizi, Shahram; Rafati, Hasan; Ghasemi, Ensieh; Alizadeh, Reza

    2010-09-21

    Platinum compounds, including cis-dichlorodiaminoplatinum(II) or cisplatin, are an important class of anti-cancer drugs, which should be carefully monitored in the biological fluids. In this study, electrodeposition coupled with electrothermal atomic absorption spectrometry (ETAAS) was used for determination of Pt concentration in the human serum samples. The chemometric techniques were also used to verify the probable interactions among the important and effective parameters in the atomization process. Using response surfaces obtained by two factorial design techniques, the experimental design was applied for three effective parameters namely ashing temperature, atomizing temperature and modifier concentration as effective parameters on the atomization of Pt. The in situ digestions of serum samples, as well as the separation of the ultra-traces of Pt from concomitant in these samples were performed by using the in situ electrodeposition (ED) technique prior to the measurement by ETAAS. Six plasma samples of a patient who was administered parenteral cisplatin were analyzed using the proposed ED-ETAAS technique. The results showed the pharmacokinetic parameters of cisplatin in serum in accordance to the well-established data. A relatively good reproducibility %RSD=2.44, low limit of detection LOD=2.54 microg/L and promising characteristic mass m(o)=91.30 pg were obtained using this technique. Copyright 2010 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Soylak, Mustafa; Kizil, Nebiye

    2011-01-01

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

  14. Determination of Aluminum in Dialysis Concentrates by Atomic Absorption Spectrometry after Coprecipitation with Lanthanum Phosphate.

    Science.gov (United States)

    Selvi, Emine Kılıçkaya; Şahin, Uğur; Şahan, Serkan

    2017-01-01

    This method was developed for the determination of trace amounts of aluminum(III) in dialysis concentrates using atomic absorption spectrometry after coprecipitation with lanthanum phosphate. The analytical parameters that influenced the quantitative coprecipitation of analyte including amount of lanthanum, amount of phosfate, pH and duration time were optimized. The % recoveries of the analyte ion were in the range of 95-105 % with limit of detection (3s) of 0.5 µg l-1. Preconcentration factor was found as 1000 and Relative Standard Deviation (RSD) % value obtained from model solutions was 2.5% for 0.02 mg L-1. The accuracy of the method was evaluated with standard reference material (CWW-TMD Waste Water). The method was also applied to most concentrated acidic and basic dialysis concentrates with satisfactory results.

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

    Science.gov (United States)

    Çiftçi, Tülin Deniz; Henden, Emur

    2016-08-01

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

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

    Science.gov (United States)

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

    1976-01-01

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

  17. [Graphite furnace atomic absorption spectrometry for determination of thallium in blood].

    Science.gov (United States)

    Zhang, Q L; Gao, G

    2016-04-20

    Colloidal palladium was used as chemical modifier in the determination of blood thallium by graphite furnace atomic absorption spectrometry. Blood samples were precipitated with 5% (V/V)nitric acid, and then determined by GFAAS with colloidal palladium used as a chemical modifier. 0.2% (W/V)sodium chloride was added in the standard series to improve the matrix matching between standard solution and sample. The detection limit was 0.2 μg/L. The correlation coefficient was 0.9991. The recoveries were between 93.9% to 101.5%.The relative standard deviations were between 1.8% to 2.7%.The certified reference material of whole blood thallium was determined and the result was within the reference range Conclusion: The method is accurate, simple and sensitive, and it can meet the needs of detection thallium in blood entirely.

  18. Neutron activation analysis and atomic absorption spectrophotometry for the analysis of fresh, pasteurised and powder milk

    Energy Technology Data Exchange (ETDEWEB)

    Wasim, M.; Rehman, S.; Arif, M.; Fatima, I.; Zaidi, J.H. [Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.

    2012-07-01

    This study shows the application of semi-absolute k{sub 0} instrumental neutron activation analysis (k{sub 0}-INAA), epithermal neutron activation analysis (ENAA) and atomic absorption spectrophotometry (AAS) for the determination of 21 elements (Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, Hf, I, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sc Sr, and Zn) in different types of milk samples. The ENAA was required for the determination of iodine, AAS for Cu, Ni and Pb and the rest of the elements were measured by k{sub 0}-INAA. Thirteen elements (Br, Ca, Cl, Cs, Cu, Fe, K, Mg, Na, P, Rb, Sr and Zn) were identified in all milk samples. Ni was detected in eleven and Pb in two samples. Concentrations of most of the elements were within the ranges of the world reported data. The data was further explored by principal component analysis to find relationships between samples and elements. (orig.)

  19. Matrix effects in the determination of molybdenum in plants by carbon furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Studnicki, M.

    1979-07-01

    Molybdenum is a microelement taken by plants in lower quantities than other microelements. The effects of different acids, cations, and anions important in plant materials are analyzed. A double-beam Instrumentation Laboratory atomic absorption spectrometer Model 251 with hydrogen background corrector, a graphite furnace IL 455, and Dohrmann Envirotech recorder Model SC 1200 were used. Acids strongly influence the Mo signal. Most of the phosphoric acid in the range 0.01 to 1% increased the signal. Ammonium salts of these acids also changed the Mo signal, but the sign of the change may be other than for the acids (for example, ammonium nitrates). Calcium chloride strongly decreased the signal. This influence was reduced in the presence of ammonium phosphate and the disodium salt of EDTA. 5 figures.

  20. Chromium determination in fly ash by slurry-sampling electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Baralkiewicz, D; Lamont, S.; Stemerowicz, M. [Adam Mickiewicz University of Poznan, Poznan (Poland). Dept. of Water & Soil Analysis

    2002-07-01

    The paper reports analytical conditions for determination of chromium in fly ash by slurry sampling electrothermal atomic absorption spectrometry (SS ETAAS). Stability test for slurries have been carried out. Triton X-100 was used as a stabilizing agent. The procedure was validated by analysis of certified reference coal fly ash material SRM 1633B. The results of determination of chromium by SS ETAAS in three real fly ash samples from Poland (Szczecin area) and Canada (Sydney, Nova Scotia area) were compared with the results of these samples analysed by the wet digestion method. The detection limit calculated to 0.077 mg/kg and relative standard deviation (RSD) of measurements for the slurry sampling method was 3.5-5.2% for SRM 1633B.

  1. Determination of selenium in Teucrium species by hydride generation atomic absorption spectrometry.

    Science.gov (United States)

    Jurisić, Renata; Vladimir-Knezević, Sanda; Kalodera, Zdenka; Grgić, Jerica

    2003-01-01

    Hydride generation atomic absorption spectrometry (HGAAS) was applied for determination of selenium content in dried aerial parts of wild and cultivated Teucrium species (Lamiaceae) growing in Croatia: T. arduini L., T. chamaedrys L., T. flavum L., T. montanum L., T. polium L., and T. scordium L. subsp. scordioides Schreb. Special attention was paid to the wet oxidation procedure for the sample dissolution. The proposed procedure involved microwave-assisted sample digestion using a mixture of HNO3/H2O2. Wild specimens generally had a higher content of selenium, with concentrations of 0.030-0.095 mg/kg of the dry drug. Cultivated plants contained 0.020-0.055 mg Se/kg.

  2. The standard calibration instrument automation system for the atomic absorption spectrophotometer. Part 3: Program documentation

    Science.gov (United States)

    Ryan, D. P.; Roth, G. S.

    1982-04-01

    Complete documentation of the 15 programs and 11 data files of the EPA Atomic Absorption Instrument Automation System is presented. The system incorporates the following major features: (1) multipoint calibration using first, second, or third degree regression or linear interpolation, (2) timely quality control assessments for spiked samples, duplicates, laboratory control standards, reagent blanks, and instrument check standards, (3) reagent blank subtraction, and (4) plotting of calibration curves and raw data peaks. The programs of this system are written in Data General Extended BASIC, Revision 4.3, as enhanced for multi-user, real-time data acquisition. They run in a Data General Nova 840 minicomputer under the operating system RDOS, Revision 6.2. There is a functional description, a symbol definitions table, a functional flowchart, a program listing, and a symbol cross reference table for each program. The structure of every data file is also detailed.

  3. Resonant two-photon absorption and electromagnetically induced transparency in open ladder-type atomic system.

    Science.gov (United States)

    Moon, Han Seb; Noh, Heung-Ryoul

    2013-03-25

    We have experimentally and theoretically studied resonant two-photon absorption (TPA) and electromagnetically induced transparency (EIT) in the open ladder-type atomic system of the 5S(1/2) (F = 1)-5P(3/2) (F' = 0, 1, 2)-5D(5/2) (F″ = 1, 2, 3) transitions in (87)Rb atoms. As the coupling laser intensity was increased, the resonant TPA was transformed to EIT for the 5S(1/2) (F = 1)-5P(3/2) (F' = 2)-5D(5/2) (F″ = 3) transition. The transformation of resonant TPA into EIT was numerically calculated for various coupling laser intensities, considering all the degenerate magnetic sublevels of the 5S(1/2)-5P(3/2)-5D(5/2) transition. From the numerical results, the crossover from TPA to EIT could be understood by the decomposition of the spectrum into an EIT component owing to the pure two-photon coherence and a TPA component caused by the mixed term.

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

    Science.gov (United States)

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

    2016-06-20

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

  5. Determination of silicon in serum and urine by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Huang, Zhuo-er

    1995-09-01

    A sensitive, simple and accurate method for the routine determination of trace silicon in serum and urine by Zeeman electrothermal atomic absorption spectrometry is described. The samples are directly determined after 20-fold dilution of serum and 100-fold dilution of urine. No L'vov platform is used. The signal enhancement of silicon atomization in pyrolytic graphite coated graphite tubes is achieved by using a mixture of calcium chloride and lanthanum nitrate as chemical modifier. The interferences arising from the biological matrices have been eliminated by the addition of ammonium dihydrogenphosphate in the sample solutions. The aqueous calibration curve is linear to at least 300 μg l -1, the characteristic mass is 37 pg (integrated absorbance signal), whereas the detection limit (3SD) is 1.5 μg l -1 for silicon in both diluted serum and urine samples. The recoveries of silicon added to the diluted samples are 101 ± 1.8% for sera and 98.2 ± 3.5% for the urine specimens, independent of the dilution ratio. The silicon measurement results for the serum and urine from healthy adults and for the serum from the patients with chronic renal failure on hemodialysis are presented.

  6. Matrix elimination method for the determination of precious metals in ores using electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Salih, Bekir [Hacettepe University, Department of Chemistry, Ankara (Turkey)]. E-mail: bekir@hacettepe.edu.tr; Celikbicak, Omuer [Hacettepe University, Department of Chemistry, Ankara (Turkey); Doeker, Serhat [Hacettepe University, Department of Chemistry, Ankara (Turkey); Dogan, Mehmet [Hacettepe University, Department of Chemistry, Ankara (Turkey)

    2007-03-28

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using {sup 60}Co {gamma} source in the ternary mixture of NHMMA-ATU-H{sub 2}O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3 M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L{sup -1} of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels.

  7. NARROW Na AND K ABSORPTION LINES TOWARD T TAURI STARS: TRACING THE ATOMIC ENVELOPE OF MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Pascucci, I.; Simon, M. N. [Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Edwards, S. [Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States); Heyer, M. [Department of Astronomy, University of Massachusetts, Amherst, MA 01003-9305 (United States); Rigliaco, E. [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Hillenbrand, L. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Gorti, U.; Hollenbach, D., E-mail: pascucci@lpl.arizona.edu [SETI Institute, Mountain View, CA 94043 (United States)

    2015-11-20

    We present a detailed analysis of narrow Na i and K i absorption resonance lines toward nearly 40 T Tauri stars in Taurus with the goal of clarifying their origin. The Na i λ5889.95 line is detected toward all but one source, while the weaker K i λ7698.96 line is detected in about two-thirds of the sample. The similarity in their peak centroids and the significant positive correlation between their equivalent widths demonstrate that these transitions trace the same atomic gas. The absorption lines are present toward both disk and diskless young stellar objects, which excludes cold gas within the circumstellar disk as the absorbing material. A comparison of Na i and CO detections and peak centroids demonstrates that the atomic gas and molecular gas are not co-located, the atomic gas being more extended than the molecular gas. The width of the atomic lines corroborates this finding and points to atomic gas about an order of magnitude warmer than the molecular gas. The distribution of Na i radial velocities shows a clear spatial gradient along the length of the Taurus molecular cloud filaments. This suggests that absorption is associated with the Taurus molecular cloud. Assuming that the gradient is due to cloud rotation, the rotation of the atomic gas is consistent with differential galactic rotation, whereas the rotation of the molecular gas, although with the same rotation axis, is retrograde. Our analysis shows that narrow Na i and K i absorption resonance lines are useful tracers of the atomic envelope of molecular clouds. In line with recent findings from giant molecular clouds, our results demonstrate that the velocity fields of the atomic and molecular gas are misaligned. The angular momentum of a molecular cloud is not simply inherited from the rotating Galactic disk from which it formed but may be redistributed by cloud–cloud interactions.

  8. Mini-Column Ion-Exchange Separation and Atomic Absorption Quantitation of Nickel, Cobalt, and Iron: An Undergraduate Quantitative Analysis Experiment.

    Science.gov (United States)

    Anderson, James L.; And Others

    1980-01-01

    Presents an undergraduate quantitative analysis experiment, describing an atomic absorption quantitation scheme that is fast, sensitive and comparatively simple relative to other titration experiments. (CS)

  9. Solid phase extraction and determination of nickel in water samples by using novel thiol-containing sulfonamide polymeric resin and atomic absorption spectrophotometer.

    Science.gov (United States)

    Karaaslan, Nagihan M; Senkal, B Filiz; Er, Cigdem; Avci, Halim; Yaman, Mehmet

    2011-08-01

    Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry as well as the high costs of other sensitive methods in compared to flame atomic absorption spectrometry. In this study, thiol-containing sulfonamide resin was synthesized, characterized and applied as a new sorption material for solid phase extraction of nickel in drinking water samples. After preconcentration procedure, flame atomic absorption spectrometry was used for determinations. Optimum parameters were found to be pH = 3.2, contact time = 20 min and eluate volume = 3 mL. The limit of detection was found to be 0.75 ng x mL(-1). The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent, high sorption capacity as well as the relatively fast extraction rate. The Ni concentrations in the studied 21 kind of water samples were found to be in the range of BDL-4.0 ng x mL(-1).

  10. Sapphire: a better material for atomization and in situ collection of silver volatile species for atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Musil, Stanislav, E-mail: stanomusil@biomed.cas.cz; Matoušek, Tomáš; Dědina, Jiří

    2015-06-01

    Sapphire is presented as a high temperature and corrosion resistant material of an optical tube of an atomizer for volatile species of Ag generated by the reaction with NaBH{sub 4}. The modular atomizer design was employed which allowed to carry out the measurements in two modes: (i) on-line atomization and (ii) in situ collection (directly in the optical tube) by means of excess of O{sub 2} over H{sub 2} in the carrier gas during the trapping step and vice versa in the volatilization step. In comparison with quartz atomizers, the sapphire tube atomizer provides a significantly increased atomizer lifetime as well as substantially improved repeatability of the Ag in situ collection signals shapes. In situ collection of Ag in the sapphire tube atomizer was highly efficient (> 90%). Limit of detection in the on-line atomization mode and in situ collection mode, respectively, was 1.2 ng ml{sup −1} and 0.15 ng ml{sup −1}. - Highlights: • Sapphire was tested as a new material of an atomizer tube for Ag volatile species. • Two measurement modes were investigated: on-line atomization and in situ collection. • In situ collection of Ag was highly efficient (> 90%) with LOD of 0.15 ng ml{sup −1}. • No devitrification of the sapphire tube observed in the course of several months.

  11. Time-resolved x-ray absorption spectroscopy: Watching atoms dance

    Energy Technology Data Exchange (ETDEWEB)

    Milne, Chris J; Pham, Van-Thai; Veen, Renske M van der; El Nahhas, Amal; Lima, Frederico; Vithanage, Dimali A; Chergui, Majed [Laboratoire de Spectroscopie Ultrarapide, Ecole Polytechnique Federale de Lausanne (Switzerland); Gawelda, Wojciech [Laser Processing Group, Instituto de Optica, CSIC (Spain); Johnson, Steven L; Beaud, Paul; Ingold, Gerhard; Grolimund, Daniel; Borca, Camelia; Kaiser, Maik; Abela, Rafael [Swiss Light Source, Paul Scherrer Institut (Switzerland); Benfatto, Maurizio [Laboratori Nazionali di Frascati, INFN (Italy); Hauser, Andreas [Departement de Chimie Physique, Universite de Geneve (Switzerland); Bressler, Christian, E-mail: majed.chergui@epfl.c, E-mail: chris.milne@psi.c [European XFEL Project Team, Deutsches Elektronen Synchrotron (Germany)

    2009-11-15

    The introduction of pump-probe techniques to the field of x-ray absorption spectroscopy (XAS) has allowed the monitoring of both structural and electronic dynamics of disordered systems in the condensed phase with unprecedented accuracy, both in time and in space. We present results on the electronically excited high-spin state structure of an Fe(II) molecular species, [Fe{sup II}(bpy){sub 3}]{sup 2+}, in aqueous solution, resolving the Fe-N bond distance elongation as 0.2 A. In addition an analysis technique using the reduced {chi}{sup 2} goodness of fit between FEFF EXAFS simulations and the experimental transient absorption signal in energy space has been successfully tested as a function of excited state population and chemical shift, demonstrating its applicability in situations where the fractional excited state population cannot be determined through other measurements. Finally by using a novel ultrafast hard x-ray 'slicing' source the question of how the molecule relaxes after optical excitation has been successfully resolved using femtosecond XANES.

  12. Overcoming Matrix Effects in a Complex Sample: Analysis of Multiple Elements in Multivitamins by Atomic Absorption Spectroscopy

    Science.gov (United States)

    Arnold, Randy J.; Arndt, Brett; Blaser, Emilia; Blosser, Chris; Caulton, Dana; Chung, Won Sog; Fiorenza, Garrett; Heath, Wyatt; Jacobs, Alex; Kahng, Eunice; Koh, Eun; Le, Thao; Mandla, Kyle; McCory, Chelsey; Newman, Laura; Pithadia, Amit; Reckelhoff, Anna; Rheinhardt, Joseph; Skljarevski, Sonja; Stuart, Jordyn; Taylor, Cassie; Thomas, Scott; Tse, Kyle; Wall, Rachel; Warkentien, Chad

    2011-01-01

    A multivitamin tablet and liquid are analyzed for the elements calcium, magnesium, iron, zinc, copper, and manganese using atomic absorption spectrometry. Linear calibration and standard addition are used for all elements except calcium, allowing for an estimate of the matrix effects encountered for this complex sample. Sample preparation using…

  13. A COMPARISON OF A SPECTROPHOTOMETRIC (QUERCETIN) METHOD AND AN ATOMIC-ABSORPTION METHOD FOR DETERMINATION OF TIN IN FOOD

    DEFF Research Database (Denmark)

    Engberg, Å

    1973-01-01

    Procedures for the determination of tin in food, which involve a spectrophotometric method (with the quercetin-tin complex) and an atomic-absorption method, are described. The precision of the complete methods and of the individual analytical steps required is evaluated, and the parameters...

  14. 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.

  15. A Simplified Digestion Protocol for the Analysis of Hg in Fish by Cold Vapor Atomic Absorption Spectroscopy

    Science.gov (United States)

    Kristian, Kathleen E.; Friedbauer, Scott; Kabashi, Donika; Ferencz, Kristen M.; Barajas, Jennifer C.; O'Brien, Kelly

    2015-01-01

    Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

  16. Assessing the Engagement, Learning, and Overall Experience of Students Operating an Atomic Absorption Spectrophotometer with Remote Access Technology

    Science.gov (United States)

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

    2015-01-01

    The use of internet-based technologies in the teaching of laboratories has emerged as a promising education tool. This study evaluated the effectiveness of using remote access technology to operate an atomic absorption spectrophotometer in analyzing the iron content in a crude myoglobin extract. Sixty-two students were surveyed on their level of…

  17. Identifying Student and Teacher Difficulties in Interpreting Atomic Spectra Using a Quantum Model of Emission and Absorption of Radiation

    Science.gov (United States)

    Savall-Alemany, Francisco; Domènech-Blanco, Josep Lluís; Guisasola, Jenaro; Martínez-Torregrosa, Joaquín

    2016-01-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two…

  18. Sample preparation for arsenic speciation analysis in baby food by generation of substituted arsines with atomic absorption spectrometry detection

    Czech Academy of Sciences Publication Activity Database

    Huber, C. S.; Vale, M. G. R.; Dessuy, M. B.; Svoboda, Milan; Musil, Stanislav; Dědina, Jiří

    2017-01-01

    Roč. 175, DEC (2017), s. 406-412 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LH15174 Institutional support: RVO:68081715 Keywords : slurry sampling * methyl-substituted arsenic species * hydride generation-cryotrapping-atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  19. Absolute number densities of helium metastable atoms determined by atomic absorption spectroscopy in helium plasma-based discharges used as ambient desorption/ionization sources for mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reininger, Charlotte; Woodfield, Kellie [Brigham Young University, Department of Chemistry and Biochemistry, Provo, UT 84602 (United States); Keelor, Joel D.; Kaylor, Adam; Fernández, Facundo M. [Georgia Institute of Technology, School of Chemistry and Biochemistry, Atlanta, GA 30332 (United States); Farnsworth, Paul B., E-mail: paul_farnsworth@byu.edu [Brigham Young University, Department of Chemistry and Biochemistry, Provo, UT 84602 (United States)

    2014-10-01

    The absolute number densities of helium atoms in the 2s {sup 3}S{sub 1} metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 10{sup 12} cm{sup −3} and 0.011 × 10{sup 12} cm{sup −3}, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 10{sup 12} cm{sup −3} and 0.97 × 10{sup 12} cm{sup −3} were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges. - Highlights: • We determine He metastable number densities for four plasma types • The highest number densities were observed in a dielectric barrier discharge • No helium metastable atoms were observed downstream from the exits of glow discharges.

  20. [Efficiency of hemoperfusion on clearing thallium based on atomic absorption spectrometry].

    Science.gov (United States)

    Tian, Tian; Wang, Yongan; Nie, Zhiyong; Wang, Jiao; Peng, Xiaobo; Yuan, Ye; Li, Wanhua; Qiu, Zewu; Xue, Yanping; Xiong, Yiru

    2015-04-01

    To determine thallium in whole blood by atomic absorption detection method, and to investigate the eliminating effect of hemoperfusion (HP) for thallium in blood. The blood of Beagle dogs which had not exposed to thallium before were obtained for preparation of thallium nitrate ( TlNO3 )-containing solution in three concentrations according to the conversion formula based on animal weight and volume of blood. HP was performed in the simulated in vivo environment. The content of TlNO3 in blood of the next group was determined on the amount of TlNO3 for the last HP of the former dose group. Thallium quantity in different samples was measured with atomic absorption spectrometer blood samples before and after HP. Finally, the thallium concentration in blood was analyzed statistically. Thallium concentrations showed a good linear relationship in the range of 0-200 μg/L (r = 0.998 4). The intra-day precision (RSD) was lower than 4.913%, the intra-day recovery rate was 96.2%-111.9%; the inter-day precision (RSD) was lower than 7.502%, the inter-day recovery rate was 89.6%-105.2%. The concentration of thallium in blood was significantly reduced after HP per time in high, middle, and low dose groups [(453.43 ± 27.80) mg/L to (56.09 ± 14.44) mg/L in high dose group, F = 8.820, P = 0.003; (64.51 ± 13.60) mg/L to (3.19 ± 0.23) mg/L in middle dose group, F = 36.312, P = 0.000; (5.40 ± 0.98) mg/L to (0.38 ± 0.25) mg/L in low dose group, F = 46.240, P = 0.000 ]. The adsorption rate of four times of HP in high, middle and low dose group were (87.63 ± 2.48 )%, (95.06 ± 1.54 )% and (92.76 ± 4.87)%, respectively, without significant difference (F = 4.231, P = 0.070). The method for measuring thallium was established, and it shows a very stable, simple, sensitive for determination of thallium. HP can effectively remove thallium from blood. Thallium concentration can be reduced by 90% after four times of HP. HP is also effective even when thallium concentration is not high.

  1. A Method for Eliminating Beam Steering Error for the Modulated Absorption-Emission Thermometry Technique

    Science.gov (United States)

    2015-01-01

    pressure budget for cooling channels reduces pump horsepower and turbine inlet temperature DISTRIBUTION STATEMENT A – Approved for public release...Beam Steering Error for the Modulated Absorption-Emission Thermometry Technique 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d...Jan 2015. PA#14562. 14. ABSTRACT Modulated absorption-emission thermometry (MAET) is a non-intrusive, radiometric technique for measuring line-of

  2. Differential determination of selenium(IV) and selenium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone by atomic-absorption spectrophotometry with a carbon-tube atomizer.

    Science.gov (United States)

    Kamada, T; Shiraishi, T; Yamamoto, Y

    1978-01-01

    The extraction behaviour of selenium(IV) and selenium(VI) with sodium diethyldithiocarbamate, ammonium pyrrolidinedithiocarbamate and dithizone in organic solvents has been investigated by means of flameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of selenium(IV) and differential determination of selenium(IV) and selenium(VI) have been developed. With sodium diethyldithiocarbamate and carbon tetrachloride, when the aqueous phase/organic solvent volume ratio is 5 and the injection volume in the carbon tube is 20 microl, the sensitivity for selenium is 0.4 ng/ml for 1% absorption. The relative standard deviations are ca. 3%. Interference by many metal ions can he prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of Se(IV) and Se(VI) in various types of water.

  3. Arsenic speciation in natural water samples by coprecipitation-hydride generation atomic absorption spectrometry combination.

    Science.gov (United States)

    Tuzen, Mustafa; Citak, Demirhan; Mendil, Durali; Soylak, Mustafa

    2009-04-15

    A speciation procedure for As(III) and As(V) ions in environmental samples has been presented. As(V) was quantitatively recovered on aluminum hydroxide precipitate. After oxidation of As(III) by using dilute KMnO(4), the developed coprecipitation was applied to determination of total arsenic. Arsenic(III) was calculated as the difference between the total arsenic content and As(V) content. The determination of arsenic levels was performed by hydride generation atomic absorption spectrometry (HG-AAS). The analytical conditions for the quantitative recoveries of As(V) including pH, amount of aluminum as carrier element and sample volume, etc. on the presented coprecipitation system were investigated. The effects of some alkaline, earth alkaline, metal ions and also some anions were also examined. Preconcentration factor was calculated as 25. The detection limits (LOD) based on three times sigma of the blank (N: 21) for As(V) was 0.012 microg L(-1). The satisfactory results for the analysis of arsenic in NIST SRM 2711 Montana soil and LGC 6010 Hard drinking water certified reference materials for the validation of the method was obtained. The presented procedure was successfully applied to real samples including natural waters for arsenic speciation.

  4. Determination of mercury distribution inside spent compact fluorescent lamps by atomic absorption spectrometry.

    Science.gov (United States)

    Rey-Raap, Natalia; Gallardo, Antonio

    2012-05-01

    In this study, spent compact fluorescent lamps were characterized to determine the distribution of mercury. The procedure used in this research allowed mercury to be extracted in the vapor phase, from the phosphor powder, and the glass matrix. Mercury concentration in the three phases was determined by the method known as cold vapor atomic absorption spectrometry. Median values obtained in the study showed that a compact fluorescent lamp contained 24.52±0.4ppb of mercury in the vapor phase, 204.16±8.9ppb of mercury in the phosphor powder, and 18.74±0.5ppb of mercury in the glass matrix. There are differences in mercury concentration between the lamps since the year of manufacture or the hours of operation affect both mercury content and its distribution. The 85.76% of the mercury introduced into a compact fluorescent lamp becomes a component of the phosphor powder, while more than 13.66% is diffused through the glass matrix. By washing and eliminating all phosphor powder attached to the glass surface it is possible to classified the glass as a non-hazardous waste. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Use of atomic absorption spectrometry in assessment of biomonitor plants for lead, cadmium and copper pollution.

    Science.gov (United States)

    Gokce, Kaya; Mehmet, Yaman

    2012-01-01

    Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep, Turkey. Lead, cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry. Lead, Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304-602, 0.4-0.44 and 31-37 mg x kg(-1), respectively. Significantly increased lead concentration up to 2 750 mg x kg(-1) was found in the leaves of Eleagnus angustifolia L. plant. The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima > Morus sp. > Juglans regia L. > Ficus carica L. > Cydonia oblonga Miller > Prunus x domestica L. The plants, Populus nigra L. , Eleagnus angustifolia L. and Salix sp. were found useful for Cd, and the plant, Eleagnus angusti folia L. for Pb, to be considered as potential biomonitor. Especially, leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations. Therefore, people who and animals which live in this area and benefit from these soil and plants have vital risks.

  6. Bismuth determination in environmental samples by hydride generation-electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Moscoso-Perez, Carmen; Moreda-Pineiro, Jorge; Lopez-Mahia, Purificacion; Muniategui-Lorenzo, Soledad; Fernandez-Fernandez, Esther; Prada-Rodriguez, Dario [Department of Analytical Chemistry, Faculty of Sciences, University of A Coruna, Campus da Zapateira s/n, E-15071, A Coruna (Spain)

    2003-12-04

    A hydride generation procedure, via flow injection, coupled to electrothermal atomic absorption spectrometry was optimised for Bi determination in sea water and hot-spring water and acid extracts from coal, coal fly ash and slag samples. The effects of several variables such as hydrochloric acid and sodium tetrahydroborate concentrations, hydrochloric acid and sodium tetrahydroborate flow rates, reaction coil length, trapping and atomisation temperatures, trapping time and the Ar flow rate have been investigated by using a 2{sup 9}*3/128 Plackett-Burman design. From these studies, certain variables (sodium tetrahydroborate concentration and trapping time) showed up as significant, and they were optimised by a 2{sup 2}+star central composite design. In addition, a study of the bismuthine trapping and atomisation efficiency from graphite tubes (GTs) permanently treated with uranium, tantalum, lanthanum oxide, niobium, beryllium oxide, chromium oxide and tantalum carbide were investigated. The results obtained were compared with those achieved by iridium and zirconium-treated GTs. The best analytical performances, with characteristic mass of 35 pg and detection limit of 70 ng l{sup -1}, were achieved by using U-treated GTs. Accuracy were checked using several reference materials: 1643d (Trace Elements in Water), TM-24 (Reference Water), GBW-07401 (Soil) and 1632c (Trace Elements in Coal)

  7. An indirect atomic absorption spectrometric determination of ciprofloxacin, amoxycillin and diclofenac sodium in pharmaceutical formulations

    Directory of Open Access Journals (Sweden)

    MAHMOUD MOHAMED ISSA

    2008-05-01

    Full Text Available A highly sensitive indirect atomic absorption spectrophotometric (AAS method has been developed for the determination of very low concentrations of ciprofloxacin, amoxycillin and diclofenac sodium. The method is based on the oxidation of these drugs with iron(III. The excess of iron(III was extracted into diethyl ether and then the iron(II in the aqueous layer was aspirated into an air–acetylene flame and determined by AAS. The linear concentration ranges were 25–400, 50–500 and 60–600 ng ml-1 for ciprofloxacin, amoxycillin and diclofenac sodium, respectively. The results were statistically compared with the official method using t- and f-test at p < 0.05. There were insignificant interferences from most of the excipients present. The intra- and inter-day assay coefficients of variation were less than 6.1 % and the recoveries ranged from 95 to 103 %. The method was applied for the analysis of these drug substances in their commercial pharmaceutical formulations.

  8. EVALUATION OF HEAVY METALS CONTENT IN EDIBLE MUSHROOMS BY MICROWAVE DIGESTION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    Cristiana Radulescu

    2011-05-01

    Full Text Available The aim of this work was to determine the heavy metal (Cd, Cr, Ni, Pb, Mn, Zn, Fe and Cu content of the fruiting bodies (cap and stipe of four species (Amanita caesarea, Pleurotus ostreatus, Fistulina hepatica and Armillariella mellea and their substrate, collected from forest sites in Dâmboviţa County, Romania. The elements were determined by Flame Atomic Absorption Spectrometry (FAAS after microwave assisted digestion. From the same collecting point were taken n = 5 samples of young and mature fruiting bodies of mushrooms and their substrate. The high concentrations of lead, chrome and cadmium (Pb: 0.25 – 1.89 mg.kg-1, Cr: 0.36 – 1.94 mg.kg-1, Cd: 0.23 – 1.13 mg.kg-1 for all collected wild edible mushrooms, were determined. These data were compared with maximum level for certain contaminants in foodstuffs established by the commission of the European Committees (EC No 466/2001. A quantitative evaluation of the relationship of element uptake by mushrooms from substrate was made by calculating the accumulation coefficient (Ka. The moderately acid pH value of soil influenced the accumulation of Zn and Cd inside of the studied species. The variation of heavy metals content between edible mushrooms species is dependent upon the ability of the species to extract elements from the substrate and on the selective uptake and deposition of metals in tissue.

  9. Column preconcentration and electrothermal atomic absorption spectrometric determination of rhodium in some food and standard samples.

    Science.gov (United States)

    Taher, Mohammad Ali; Pourmohammad, Fatemeh; Fazelirad, Hamid

    2015-12-01

    In the present work, an electrothermal atomic absorption spectrometric method has been developed for the determination of ultra-trace amounts of rhodium after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol/tetraphenylborate ion associated complex at the surface of alumina. Several factors affecting the extraction efficiency such as the pH, type of eluent, sample and eluent flow rates, sorption capacity of alumina and sample volume were investigated and optimized. The relative standard deviation for eight measurements of 0.1 ng/mL of rhodium was ±6.3%. In this method, the detection limit was 0.003 ng/mL in the original solution. The sorption capacity of alumina and the linear range for Rh(III) were evaluated as 0.8 mg/g and 0.015-0.45 ng/mL in the original solution, respectively. The proposed method was successfully applied for the extraction and determination of rhodium content in some food and standard samples with high recovery values. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Graphite furnace atomic absorption spectrometric determination of cadmium after solid-liquid extraction with dithizone

    Directory of Open Access Journals (Sweden)

    Azizollah Nezhadali

    2009-08-01

    Full Text Available A method for the determination of trace amount of cadmium ion after preconcentration by extracting its dithizone complex into molten naphthalene was developed. Several experimental conditions such as pH of the solution, stirring time, the amounts of naphthalene, standing time and volume of the solution were optimized. Trace amount of cadmium ion in aqueous solution of sample was chelated with 5 mL of 0.001 M dithizone at pH 8. After addition of 0.15 g naphthalene, the solution was heated to about 85 oC and stirred (800 rpm for 2 min to reproduce the microcrystalline naphthalene. Cadmium ion was determined by a graphite furnace atomic absorption spectrometer. The interfering effects of diverse concomitant ions (cations and anions were investigated. Artificial sea water and a standard reference material (SRM were analyzed by this method. The sensitivity and detection limit of 1.2 ngL-1 and 1.5 ng L-1 were found, respectively.

  11. Stabilizing Agents for Calibration in the Determination of Mercury Using Solid Sampling Electrothermal Atomic Absorption Spectrometry

    Science.gov (United States)

    Zelinková, Hana; Červenka, Rostislav; Komárek, Josef

    2012-01-01

    Tetramethylene dithiocarbamate (TMDTC), diethyldithiocarbamate (DEDTC), and thiourea were investigated as stabilizing agents for calibration purposes in the determination of mercury using solid sampling electrothermal atomic absorption spectrometry (SS-ETAAS). These agents were used for complexation of mercury in calibration solutions and its thermal stabilization in a solid sampling platform. The calibration solutions had the form of methyl isobutyl ketone (MIBK) extracts or MIBK-methanol solutions with the TMDTC and DEDTC chelates and aqueous solutions with thiourea complexes. The best results were obtained for MIBK-methanol solutions in the presence of 2.5 g L−1 TMDTC. The surface of graphite platforms for solid sampling was modified with palladium or rhenium by using electrodeposition from a drop of solutions. The Re modifier is preferable due to a higher lifetime of platform coating. A new SS-ETAAS procedure using the direct sampling of solid samples into a platform with an Re modified graphite surface and the calibration against MIBK-methanol solutions in the presence of TMDTC is proposed for the determination of mercury content in solid environmental samples, such as soil and plants. PMID:22654606

  12. Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Elsheimer, H.N.; Fries, T.L.

    1990-01-01

    A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

  13. [Determination of soil exchangeable base cations by using atomic absorption spectrophotometer and extraction with ammonium acetate].

    Science.gov (United States)

    Zhang, Yu-ge; Xiao, Min; Dong, Yi-hua; Jiang, Yong

    2012-08-01

    A method to determine soil exchangeable calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) by using atomic absorption spectrophotometer (AAS) and extraction with ammonium acetate was developed. Results showed that the accuracy of exchangeable base cation data with AAS method fits well with the national standard referential soil data. The relative errors for parallel samples of exchangeable Ca and Mg with 66 pair samples ranged from 0.02%-3.14% and 0.06%-4.06%, and averaged to be 1.22% and 1.25%, respectively. The relative errors for exchangeable K and Na with AAS and flame photometer (FP) ranged from 0.06%-8.39% and 0.06-1.54, and averaged to be 3.72% and 0.56%, respectively. A case study showed that the determination method for exchangeable base cations by using AAS was proven to be reliable and trustable, which could reflect the real situation of soil cation exchange properties in farmlands.

  14. Detection of Glucose with Atomic Absorption Spectroscopy by Using Oligonucleotide Functionalized Gold Nanoparticle.

    Science.gov (United States)

    Zhang, Hong; Yan, Honglian; Ling, Liansheng

    2016-06-01

    A novel method for the detection of glucose was established with atomic absorption spectroscopy by using the label of gold nanoparticle (AuNP). Silver-coated glass assembled with oligonucleotide 5'-SH-T12-AGA CAA GAG AGG-3' (Oligo 1) was acted as separation probe, oligonucleotide 5'-CAA CAG AGA ACG-T12-SH-3' modified gold nanoparticle (AuNP-Oligo 2) was acted as signal-reporting probe. Oligonucleotide 5'-CGT TCT CTG TTG CCT CTC TTG TCT-3' (Oligo 3) could hybridize with Oligo 1 on the surface of silver-coated glass and AuNP-Oligo 2, and free AuNP-Oligo 2 could be removed by rinsing with buffer. Hence the concentration of Oligo 3 was transformed into the concentration of gold element. In addition, Oligo 3 could be cleaved into DNA fragments by glucose, glucose oxidase and Fe(2+)-EDTA through Fenton reaction. Thereby the concentration of glucose could be transformed to the absorbance of gold element. Under the optimum conditions, the integrated absorbance decreased proportionally to the concentration of glucose over the range from 50.0 μM to 1.0 mM with a detection limit of 40.0 μM. Moreover, satisfactory result was obtained when the assay was used to determinate glucose in human serum.

  15. [Detecting Thallium in Water Samples using Dispersive Liquid Phase Microextraction-Graphite Furnace Atomic Absorption Spectroscopy].

    Science.gov (United States)

    Zhu, Jing; Li, Yan; Zheng, Bo; Tang, Wei; Chen, Xiao; Zou, Xiao-li

    2015-11-01

    To develope a method of solvent demulsification dispersive liquid phase microextraction (SD-DLPME) based on ion association reaction coupled with graphite furnace atomic absorption spectroscopy (GFAAS) for detecting thallium in water samples. Methods Thallium ion in water samples was oxidized to Tl(III) with bromine water, which reacted with Cl- to form TlCl4-. The ionic associated compound with trioctylamine was obtained and extracted. DLPME was completed with ethanol as dispersive solvent. The separation of aqueous and organic phase was achieved by injecting into demulsification solvent without centrifugation. The extractant was collected and injected into GFAAS for analysis. With palladium colloid as matrix modifier, a two step drying and ashing temperature programming process was applied for high precision and sensitivity. The linear range was 0.05-2.0 microg/L, with a detection limit of 0.011 microg/L. The relative standard derivation (RSD) for detecting Tl in spiked water sample was 9.9%. The spiked recoveries of water samples ranged from 94.0% to 103.0%. The method is simple, sensitive and suitable for batch analysis of Tl in water samples.

  16. Determination of toxic metals in some herbal drugs through atomic absorption spectroscopy.

    Science.gov (United States)

    Hina, Bushra; Rizwani, Ghazala Hafeez; Naseem, Shahid

    2011-07-01

    This study presents a picture of occurrence of heavy metals (Pb, Cd, Cu, Cr, Co, Fe, Ni, Zn) in some selected valuable herbal drugs (G. glabra, O. bracteatum, V. odorata , F. vulgare, C. cyminum, C. sativum, and Z. officinalis) purchased from three different zones (southern, eastern, and western) of Karachi city using atomic absorption spectrophotometer. Heavy metal concentrations in these drugs were found in the range of: 3.26-30.46 for Pb, 1.6-4.91 for Cd, 0.65-120.21 for Cu, 83.74-433.76 for Zn, 1.61-186.75 for Cr, 0.48-76.97 for Ni, 5.54-77.97 for Co and 65.68-1652.89 µg/g for Fe. Percentage of heavy metals that were found beyond the permissible limits were: 71.4% for Pb, 28.51% for Cd, 14.2% for Cu, and 9.5 % for Cr. Significant difference was noticed for each heavy metal among herbal drugs as well as their zones of collection using two way ANOVA followed by least significant (LSD) test at p<0.05.Purpose of this research is to detect each type of heavy metal contaminant of herbal drugs by environmental pollution, as well as to highlight the health risks associated with the use of such herbal drugs that contain high levels of toxic heavy metals.

  17. [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.

  18. Determination of Gold in Various Environment Samples by Flame Atomic Absorption Spectrometry Using Dispersive Liquid–Liquid Microextraction Sampling

    Directory of Open Access Journals (Sweden)

    Şerife Saçmacı

    2015-07-01

    Full Text Available A new dispersive liquid–liquid microextraction separation/preconcentration procedure as a rapid sample-preparation technique is proposed for detection of ultra trace amounts of Au(III in various media by flame atomic absorption spectrometry using 1,5-diphenyl-1,3,5-pentanetrione as chelating agent. Carbon tetrachloride and methanol were used as extraction and dispersive solvents, respectively. Various parameters that affect the extraction efficiency such as pH, centrifugation rate and time, chelating agent concentration and sampling volume on the recovery of Au(III were investigated. Under optimum conditions, the enhancement factor of 750, relative standard deviation of 2.7 % and calibration graphs obtained in the concentration range of 0.04–5.6 μg L−1 for gold were obtained. The limit of detection was 1.1 ng L−1. The accuracy of the method was performed by analysis of the certified reference material (CDN-PGMS-10. The developed method was applied successfully to the determination of gold in the catalytic converter, anode slime, ore and seawater samples. The results show that dispersive liquid–liquid microextraction procedure is sensitive, rapid, simple and safe for the separation/preconcentration of gold from complex sample media.

  19. Quantification of minerals and trace elements in raw caprine milk using flame atomic absorption spectrophotometry and flame photometry.

    Science.gov (United States)

    Singh, Mahavir; Yadav, Poonam; Garg, V K; Sharma, Anshu; Singh, Balvinder; Sharma, Himanshu

    2015-08-01

    This study reports minerals and trace elements quantification in raw caprine milk of Beetal breed, reared in Northern India and their feed, fodder & water using flame atomic absorption spectrophotometry and flame photometry. The mineral and trace elements' concentration in the milk was in the order: K > Ca > Na > Fe > Zn > Cu. The results showed that minerals concentration in caprine milk was lesser than reference values. But trace elements concentration (Fe and Zn) was higher than reference values. Multivariate statistical techniques, viz., Pearsons' correlation, Cluster analysis (CA) and Principal component analysis (PCA) were applied to analyze the interdependences within studied variables in caprine milk. Significantly positive correlations were observed between Fe - Zn, Zn - K, Ca - Na and Ca - pH. The results of correlation matrix were further supported by Cluster analysis and Principal component analysis as primary cluster pairs were found for Ca - pH, Ca - Na and Fe - Zn in the raw milk. No correlation was found between mineral & trace elements content of the milk and feed.

  20. A new approach to mineralization of flaxseed (Linum usitatissimum L.) for trace element analysis by flame atomic absorption spectrometry.

    Science.gov (United States)

    Oliveira, João P S; Silva, Francisco L F; Monte, Raimundo J G; Matos, Wladiana O; Lopes, Gisele S

    2017-06-01

    A new approach to the analysis of Cu, Fe, Mn and Zn in flaxseed was developed based on infrared-assisted acid digestion. Quantitation by flame atomic absorption spectrometry yields results in agreement with those arising from aggressive total decomposition using conventional microwave-assisted (MW) digestions. A full factorial design in two levels was applied to evaluate the impact of significant variables for all elements to determine optimal experimental conditions. A desirability function revealed these to be: 2.0g sample mass, 8mL of HNO3 and 8min of heating time in the IR system. Precision better than 10% (RSD) was obtained, superior to that of a combined IR-MW approach. Sample preparation based on IR-assisted digestion provides a rapid and inexpensive alternative to other conventional techniques for the analysis of complex samples and is able to accommodate relatively large masses of sample, alleviating potential homogeneity issues as well as enhancing detection power. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. [Determination of trace elements in Lophatherum gracile brongn from different habitat by microwave digestion-atomic absorption spectroscopy].

    Science.gov (United States)

    Yuan, Ke; Xue, Yue-Qin; Gui, Ren-Yi; Sun, Su-Qin; Yin, Ming-Wen

    2010-03-01

    A method of microwave digestion technique was proposed to determine the content of Zn, Fe, Cu, Mn, K, Ca, Mg, Ni, Cd, Pb, Cr, Co, Al, Se and As in Lophatherum gracile brongn of different habitat by atomic absorption spectroscopy. The RSD of the method was between 1.23% and 3.32%, and the recovery rates obtained by standard addition method were between 95.8% and 104.20%. The results of the study indicate that the proposed method has the advantages of simplicity, speediness and sensitivity. It is suitable for the determination of the contents of metal elements in Lophatherum gracile brongn. The experimental results also indicated that different areas' Lophantherum gracile brongn had different trace elements content. The content of trace elements K, Mg, Ca, Fe and Mn beneficial to the human body was rich. The content of the heavy metal trace element Pb in Lophantherum gracile brongn of Hunan province was slightly high. The content of the heavy metal trace element Cu in Lophantherum gracile brongn of Guangdong province and Anhui province is also slightly higher. Beside, the contents of harmful trace heavy metal elements Cd, Cu, Cr, Pb and As in Lophatherum gracile brongn of different habitat are all lower than the limits of Chinese Pharmacopoeia and Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation and National Food Sanitation Standard. These determination results provided the scientific data for further discussing the relationship between the content of trace elements in Lophantherum gracile brongn and the medicine efficacy.

  2. 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.

  3. Temperature-controlled electrothermal atomization-atomic absorption spectrometry using a pyrometric feedback system in conjunction with a background monitoring device

    Science.gov (United States)

    Van Deijck, W.; Roelofsen, A. M.; Pieters, H. J.; Herber, R. F. M.

    The construction of a temperature-controlled feedback system for electrothermal atomization-atomic absorption spectrometry (ETA-AAS) using an optical pyrometer applied to the atomization stage is described. The system was used in conjunction with a fast-response background monitoring device. The heating rate of the furnace amounted to 1400° s -1 with a reproducibility better than 1%. The precision of the temperature control at a steady state temperature of 2000°C was 0.1%. The analytical improvements offered by the present system have been demonstrated by the determination of cadmium and lead in blood and finally by the determination of lead in serum. Both the sensitivity and the precision of the method have been improved. The accuracy of the method was checked by determining the lead content for a number of scrum samples both by ETA-AAS and differential pulse anodic stripping voltametry (DPASV) and proved to be satisfactory.

  4. An Insight Into the Two Costing Technique: Absorption Costing and Marginal Costing

    OpenAIRE

    Mariam Nawaz

    2013-01-01

    This paper will investigate the controversy that is innate between the two costing techniques; Absorption Costing and Marginal Costing and would throw light on which costing technique better serves its purpose in helping management for decision making process and if Marginal Costing technique is concluded as better technique then why it should not be used for external reporting purpose. This paper will only crystallize and highlight the issues descriptively and will not resolve the issues tha...

  5. Study on the absorption uniformity of optical thin films based on the photothermal detuning technique.

    Science.gov (United States)

    Hao, Honggang; Zhou, Ao; Rao, Min

    2012-10-01

    Absorption loss in optical components, particularly in optical coatings, is a limiting factor in high-power laser applications. The uniformity of optical coatings becomes more and more important as large-diameter optical devices are used widely. In this paper, the photothermal detuning technique used for absorption uniformity measurement of optical thin films is developed for the first time. Experiments are conducted with a highly reflective coating used in 514 nm to measure the photothermal detuning signal and to evaluate the absorption at 514 nm by detecting the spectral shift with a probe beam at a wavelength of 632.8 nm. The relative absorption at different points on the sample surface can be measured by moving the sample two-dimensionally, and we use the measured data to make the absorption image. The results show that the designed experimental system can be used to analyze the absorption uniformity of optical coatings. The obtained images reflect the absorption uniformity of the sample well. The absorption uniformities of the two samples analyzed in this experiment are different. The film coated on fused silica is better. The research provides a powerful and convenient tool for absorption uniformity measurement of optical thin film.

  6. Ultra-Trace Determination of Copper and Silver in Environmental Samples by Using Ionic Liquid-Based Single Drop Microextraction-Electrothermal Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    J. Abolhasani

    2013-11-01

    Full Text Available A sensitive, selective and effective ionic liquid-based single drop microextraction technique wasdeveloped by using ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate, C6MIMPF6, coupledwith electrothermal atomic absorption spectrometry (ETAAS for the determination of copper and silver inenvironmental samples. Dithizone was used as chelating agent. Several factors that influence themicroextraction efficiency and ETAAS signal, such as pH, dithizone concentration, extraction time, amounts ofionic liquid, stirring rate, pyrolysis and atomization temperature were investigated and the microextractionconditions were established. In the optimum experimental conditions, the detection limits (3 s of the methodwere 4 and 8 ng L-1 and corresponding relative standard deviations (0.1 μg L-1, n = 6 were 4.2% and 4.8% forAg and Cu, respectively. The developed method was validated by analysis of a certified reference material andapplied to the determination of silver and copper.

  7. Determination of arsenic, antimony, and selenium in coal by atomic absorption spectrometry with a graphite tube atomizea

    Science.gov (United States)

    Aruscavage, Philip

    1977-01-01

    Submicrogram quantities of antimony, arsenic, and selenium in coal samples are determined by an atomic absorption procedure using an electrically heated graphite atomizer. The samples are decomposed in a mixture of nitric, sulfuric, and perchloric acids and are separated and concentrated by extraction from sulfuric acid-iodide solution into toluene. The results obtained on several intralaboratory reference samples and the National Bureau of Standards coal 1632 are compared with results from other methods. The determination can be made routinely for concentrations as small as 0.1 parts per million for arsenic, antimony, and selenium in the coal.

  8. Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure

    Science.gov (United States)

    Korecki, P.; Tolkiehn, M.; Dąbrowski, K. M.; Novikov, D. V.

    2011-01-01

    Projections of the atomic structure around Nb atoms in a LiNbO3 single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10 Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples. PMID:21997909

  9. Studies on calcium absorption from milk using a double-label stable isotope technique.

    Science.gov (United States)

    Fairweather-Tait, S J; Johnson, A; Eagles, J; Ganatra, S; Kennedy, H; Gurr, M I

    1989-09-01

    Calcium absorption was measured in ten male volunteers from skimmed milk, Ca-enriched skimmed milk or watercress (Nasturtium officinale) soup. The foods were labelled extrinsically with 30 mg 44Ca. Shortly after consuming the labelled meal, each subject was given an intravenous injection of 3 mg 42Ca. Fractional absorption from the oral dose was determined from plasma and urine samples collected 24-72 h later, using fast atom bombardment mass spectrometry to measure isotope ratios. The values for urine and plasma were in good agreement. Mean percentage absorption was 45.5 (SEM 1.9)% from the skimmed milk, 35.7 (SEM 4.7)% from the Ca-enriched milk and 27.4 (SEM 1.9)% from the watercress soup. The effect of consuming 568 ml (1 pint) Ca-enriched milk each day for 4 weeks on the efficiency of absorption of Ca was studied. Although there was no statistically significant difference between Ca absorption before and after the supplementation period, the results were considered to be somewhat inconclusive due to the small number of subjects and wide individual variation in Ca absorption.

  10. Comparison of colorimetry and electrothermal atomic absorption spectroscopy for the quantification of non-transferrin bound iron in human sera.

    Science.gov (United States)

    Jittangprasert, Piyada; Wilairat, Prapin; Pootrakul, Pensri

    2004-12-01

    This paper describes a comparison of two analytical techniques, one employing bathophenanthrolinedisulfonate (BPT), a most commonly-used reagent for Fe (II) determination, as chromogen and an electrothermal atomic absorption spectroscopy (ETAAS) for the quantification of non-transferrin bound iron (NTBI) in sera from thalassemic patients. Nitrilotriacetic acid (NTA) was employed as the ligand for binding iron from low molecular weight iron complexes present in the serum but without removing iron from the transferrin protein. After ultrafiltration the Fe (III)-NTA complex was then quantified by both methods. Kinetic study of the rate of the Fe (II)-BPT complex formation for various excess amounts of NTA ligand was also carried out. The kinetic data show that a minimum time duration (> 60 minutes) is necessary for complete complex formation when large excess of NTA is used. Calibration curves given by colorimetric and ETAAS methods were linear over the range of 0.15-20 microM iron (III). The colorimetric and ETAAS methods exhibited detection limit (3sigma) of 0.13 and 0.14 microM, respectively. The NTBI concentrations from 55 thalassemic serum samples measured employing BPT as chromogen were statistically compared with the results determined by ETAAS. No significant disagreement at 95% confidence level was observed. It is, therefore, possible to select any one of these two techniques for determination of NTBI in serum samples of thalassemic patients. However, the colorimetric procedure requires a longer analysis time because of a slow rate of exchange of NTA ligand with BPT, leading to the slow rate of formation of the colored complex.

  11. Chemical modifiers in arsenic determination in biological materials by tungsten coil electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, C.G.; Huerta, V.N.; Neira, J.Y. [Departamento de Analisis Instrumental, Facultad de Farmacia, Universidad de Concepcion, P.O. Box 237, Concepcion (Chile)

    2004-01-01

    Palladium, iridium, and rhodium are evaluated as possible chemical modifiers in the determination of As in digest solutions of biological materials (human hair and clam) by tungsten coil electrothermal atomic absorption spectrophotometry (TCA-AAS). The modifier in solution was applied onto the coil and thermally pre-reduced; the pre-reduction conditions, the amount of modifier, and the thermal program were optimized. Palladium was not satisfactory, whereas Ir and Rh were effective modifiers and rendered better relative sensitivity for As by a factor of 1.4 and 1.9, respectively compared to the case without modifier. Upon optimization of thermal conditions for As in pre-reduced Ir (2.0 {mu}g) and Rh (2.0 {mu}g) modifiers and in the digest solutions of the study matrices, Rh (2.0 {mu}g) was more effective modifier and was selected as such. The mean within-day repeatability was 2.8% in consecutive measurements (25-100 {mu}g L{sup -1}) (3 cycles, each of n=6) and confirmed good short-term stability of the absorbance measurements. The mean reproducibility was 4.4% (n=20 in a 3-day period) and the detection limit (3{sigma}{sub blank}/slope) was 29 pg (n=15). The useful coil lifetime in Rh modifier was extended to 300-400 firings. Validation was by determination of As in the certified reference material (CRM) of ''Oyster tissue'' solution with a percentage relative error (E{sub rel}%) of 2% and percentage relative standard deviation (RSD%) of 3% (n=4), and by analytical recovery of As spiked in CRM of human hair [94{+-}8% (n=4)]. The methodology is simple, fast (sample readout frequency 21 h{sup -1}), reliable, of low cost, and was applied to the determination of As in hair samples of exposed and unexposed workers. (orig.)

  12. Speciation of methylmercury in market seafood by thermal degradation, amalgamation and atomic absorption spectroscopy.

    Science.gov (United States)

    Ruiz-de-Cenzano, Manuela; Rochina-Marco, Arancha; Cervera, M Luisa; de la Guardia, Miguel

    2014-09-01

    Sample thermal decomposition followed by mercury amalgamation and atomic absorption has been employed for the determination of methylmercury (MeHg) in fish. The method involves HBr leaching of MeHg, extraction into toluene, and back-extraction into an aqueous l-cysteine solution. Preliminary studies were focused on the extraction efficiency, losses, contaminations, and species interconversion prevention. The limit of detection was 0.018µgg(-1) (dry weight). The intraday precision for three replicate analysis at a concentration of 4.2µgg(-1) (dry weight) was 3.5 percent, similar to the interday precision according to analysis of variance (ANOVA). The accuracy was guaranteed by the use of fortified samples involving 83-105 percent recoveries, and certified reference materials TORT-2 (lobster hepatopancreas) and DORM-3 (dogfish liver), providing 107 and 98 percent recovery of certified values. The greenness of the method was also evaluated with the analytical eco-scale being obtained a final score of 73 points which means an acceptable green analysis. The method was applied to fifty-seven market samples of different fish acquired from local markets in several sampling campaigns. The content of MeHg found varied between 0.0311 and 1.24µgg(-1) (wet weight), with values that involve 33-129 percent of the total mercury content. Some considerations about food safety were also done taking into account data about Spanish fish consume and Tolerable Weekly Intake (TWI) established for MeHg. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Determination of Mercury in Mainstream Cigarette Smoke by Conventional and Amalgamation Cold Vapor Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    McDaniel RL

    2014-12-01

    Full Text Available A method for differentiation of gas- and particulate-phase mercury in mainstream cigarette smoke was developed using electrostatic precipitation (EP as the trap for the particulate phase and impingers containing acidic potassium permanganate solution as the trap for the gas-phase portion. The mercury collected from the gas phase was analyzed by conventional cold vapor atomic absorption spectrometry (CVAAS and the particulate phase was analyzed by gold amalgamation CVAAS. Cigarettes were smoked under two smoking regimes, FTC (35-mL puff volume, 2 s puff duration and one puff every 60 s and an alternative (45-mL puff volume, 2 s puff duration, one puff every 30 s and 50% of any ventilation holes blocked currently recommended by the Massachusetts Department of Health. For the 1R4F reference cigarette smoked under the FTC smoking regime, the mercury found in the particulate phase was less than 0.2 ng/cig, compared with 4.9 ng/cig in the gas phase. By changing smoking parameters, the mercury concentration in mainstream smoke was found to change proportional to the delivery of cigarette smoke condensate (CSC for the same type of cigarette. However, the mercury level for different types of cigarettes smoked under the same smoking parameters had no linear relationship with CSC delivery. Spiked recovery was 98% AA± 8% for gas-phase mercury and 97% AA± 2% for the particulate phase. These results indicate that the analytical method developed is suitable for the determination of mercury in mainstream smoke. For routine analytical work in a smoking laboratory, only the gas phase needs to be analyzed for determination of mercury in mainstream smoke because the amount of mercury in the particulate phase is negligible.

  14. Atomic Absorption Spectrometry in Wilson's Disease and Its Comparison with Other Laboratory Tests and Paraclinical Findings.

    Science.gov (United States)

    Mahjoub, Fatemeh; Fereiduni, Rana; Jahanzad, Isa; Farahmand, Fatemeh; Monajemzadeh, Maryam; Najafi, Mehri

    2012-03-01

    Wilson's disease (WD) is an autosomal recessive disease with genetic abnormality on chromosome 13 causing defect in copper metabolism and increased copper concentration in liver, central nervous system and other organs, which causes different clinical manifestations. The aim of this study was to determine the sensitivity of different clinical and paraclinical tests for diagnosis of Wilson's disease. Paraffin blocks of liver biopsy from 41 children suspicious of WD were collected. Hepatic copper concentrations were examined with atomic absorption spectrophotometry (Australian GBC, model: PAL 3000). Fifteen specimens had hepatic copper concentration (dry weight) more than 250μg/g. Clinical and laboratory data and histologic slides of liver biopsies of these 15 children were reviewed retrospectively. Liver tissue was examined for staging and grading of hepatic involvement and also stained with rubeonic acid method for copper. Patients were 5-15 years old (mean age=9.3 years, standard deviation=2.6) with slight male predominance (9/15=60%). Five (33%) patients were 10 years old. Three (20%) of them were referred for icterus, 8 (54%) because of positive family history, 2 (13%) due to abdominal pain and 2 (13%) because of hepatosplenomegaly and ascites. Serum AST and ALT levels were elevated at the time of presentation in all patients. In liver biopsy, histological grade and stage was 0-8 and 0-6 respectively, 2 (13%) had cirrhosis, 1 (7%) had normal biopsy and 12 (80%) showed chronic hepatitis. Hepatic copper concentrations were between 250 and 1595 μg/g dry weight. The sensitivity of various tests were 85% for serum copper, 83% for serum ceruloplasmin, 53% for urinary copper excretion, 44% for presence of KF ring and 40% for rubeonic acid staining on liver biopsies. None of the tests stated in the article were highly sensitive for diagnosis of WD, so we suggest that diagnosis should be based on combination of family history, physical examination and different tests.

  15. Evaluation of Serum Copper Level in Naswar (Smokeless Tobacco) Addicts Using Flame Atomic Absorption Spectroscopy.

    Science.gov (United States)

    Ullah, Asmat; Khan, Abad; Iqbal, Zafar; Khan, Ismail

    2017-10-01

    Substance abuse and its consequences are a matter of great concern in South-East Asian countries, especially Pakistan and Afghanistan. Due to contamination of Naswar with copper, or by any other physiological mechanism, there is a great chance of copper poisoning in addicts. Keeping in view the literature, there is no comparative study on serum copper levels (SCuL) in Naswar addicts. Therefore, it is very important to evaluate SCuL in this population. The current study was performed in September 2016 where a total of 75 volunteers (selected from villages near the University of Peshawar, Pakistan) were grouped as Naswar addicts (n = 45) and the control group (n = 30). The addicts were compared to controls for age, weight, BMI, FBS and creatinine clearance. For serum analysis, about 3mL of blood was collected from which the serum was separated, digested, and then evaluated for SCuL using  flame atomic absorption spectroscopy at the Department of Pharmacy and Centralized Resource Laboratory of University of Peshawar. The SCuL in addicts had a range of 2.6 to 11.1 µg/dL with a mean of 5.1 ± 2.4 µg/dL. In the healthy control group, SCuL was between 1.7 to 3.9 µg/dL with a mean of 2.6 ±0.1 µg/dL. The mean difference between the two study groups was statistically significant (P = 0.005); the duration of addiction and quantity of drug consumptions per day correlated positively with SCuL. Serum level of copper in Naswar addicts is elevated compared to the Control group. The exact cause of SCuL elevations and the mechanisms involved must be studied in large group samples.

  16. Absorptance measurements of transmissive optical components by the surface thermal lensing technique

    Energy Technology Data Exchange (ETDEWEB)

    Chow, R.; Taylor, J.R.; Wu, Z.L.; Han, Y.; Tian, L.Y.

    1997-09-24

    The surface thermal lensing technique (STL) successfully resolved and measured the absorptance of transmissive optical components: near- normal angle-of-incidence anti-reflectors and beam splatters. The STL system uses an Ar ion laser to pump the components at 514.5 mn. The absorptance-induced surface deformation diffracts the HeNe probe beam into a photo-detector. The signal intensity was calibrated with a sample of known absorptance. The optical components were designed to function in a copper vapor laser (CVL) transport system, and were previously tested for absorptance with a high power CVL system at 511 rtm. To assure proper absorptance data from the STL system, the pump laser power densities were set at the operational level of the coatings, absorptance time trends were monitored, and absorptance area scans were made. Both types of transmissive optics are more stable than the CVL high reflectors that were measured in another study. Parameter studies based on Fresnel diffraction theory were also performed to optimize experimental condition. The STL system was assessed to have 10 ppb sensitivity for absorption measurement given 2 W of pump power.

  17. [Novel Hyphenated Techniques of Atomic Spectrometry for Metal Species Interaction with Biomolecules].

    Science.gov (United States)

    Li, Yan; Yan, Xiu-ping

    2015-09-01

    Trace metals may be adopted by biological systems to assist in the syntheses and metabolic functions of genes (DNA and RNA) and proteins in the environment. These metals may be beneficial or may pose a risk to humans and other life forms. Novel hybrid techniques are required for studies on the interaction between different metal species and biomolecules, which is significant for biology, biochemistry, nutrition, agriculture, medicine, pharmacy, and environmental science. In recent years, our group dwells on new hyphenated techniques based on capillary electrophoresis (CE), electrothermal atomic absorption spectrometry (ETAAS), and inductively coupled plasma mass spectroscopy (ICP-MS), and their application for different metal species interaction with biomolecules such as DNA, HSA, and GSH. The CE-ETAAS assay and CE-ICP-MS assay allow sensitively probing the level of biomolecules such as DNA damage by different metal species and extracting the kinetic and thermodynamic information on the interactions of different metal species with biomolecules, provides direct evidences for the formation of different metal species--biomolecule adducts. In addition, the consequent structural information were extracted from circular dichroism (CD) and X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and Fourier transform infrared (FTIR) spectroscopy. The present works represent the most complete and extensive study to date on the interactions between different metal species with biomolecules, and also provide new evidences for and insights into the interactions of different metal species with biomolecules for further understanding of the toxicological effects of metal species.

  18. Evaluation of solid sampling for determination of Mo, Ni, Co, and V in soil by high-resolution continuum source graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Babos, Diego Victor; Barros, Ariane Isis; Ferreira, Edilene Cristina; Neto, José Anchieta Gomes

    2017-04-01

    New methods are proposed for the determination of Mo, Ni, Co, and V in soils using high-resolution continuum source graphite furnace atomic absorption spectrometry with direct solid sampling. Cobalt and V were simultaneously determined, and different analytical lines of Ni and V were monitored to adjust sensitivity for each sample. Accuracy was checked by means of soil certified reference materials, and also by flame atomic absorption spectrometry as comparative technique. The results for Mo, Ni, Co, and V found by proposed methods were in agreement with certified values and with those obtained by the comparative technique at 95% confidence level. The concentrations found in different soil samples were in the ranges 0.19-1.84 mg kg- 1 (Mo), 9.2-22.7 mg kg- 1 (Ni), 1.1-10.7 mg kg- 1 (Co), and 35.6-426.1 mg kg- 1 (V). The relative standard deviations were in the ranges 3.2-10% (Mo), 2.8-9.8% (Ni), 4.0-9.2% (Co), and 1.2-8.0% (V). The limits of quantification for Mo, Ni, Co, and V were 0.027, 0.071, 0.15, and 1.43 ng, respectively.

  19. Separation and preconcentration of trace amounts of gold from water samples prior to determination by flame atomic absorption spectrometry

    OpenAIRE

    Sabermahani,Fatemeh; Taher,Mohammad Ali; Bahrami, Habibe

    2016-01-01

    A preconcentration/separation procedure is presented for the solid phase extraction of trace gold(III) as its rubeanic acid (dithiooxamide) chelate on silica gel, prior to determination by flame atomic absorption spectrometry. The influences of analytical parameters including pH of the aqueous solution, the amount of the sorbent, time of the complex formation, ligand amount, flow rates of sample and elution solutions and the type, concentration and volume of elution solution on the quantitati...

  20. [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.

  1. Detection of lead in Zea mays by dual-energy X-ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy.

    Science.gov (United States)

    Reale, Lucia; Kaiser, Jozef; Pace, Loretta; Lai, Antonia; Flora, Francesco; Angelosante Bruno, Antonella; Tucci, Adele; Zuppella, Paola; Mancini, Lucia; Tromba, Giuliana; Ruggieri, Fabrizio; Fanelli, Maria; Malina, Radomir; Liska, Miroslav; Poma, Anna

    2010-06-01

    This study is related to the application of the X-ray dual-energy microradiography technique together with the atomic absorption spectroscopy (AAS) for the detection of lead on Zea mays stem, ear, root, and leaf samples. To highlight the places with lead intake, the planar radiographs taken with monochromatic X-ray radiation in absorption regime with photon energy below and above the absorption edge of a given chemical element, respectively, are analyzed and processed. To recognize the biological structures involved in the intake, the dual-energy images with the lead signal have been compared with the optical images of the same Z. mays stem. The ear, stem, root, and leaf samples have also been analyzed with the AAS technique to measure the exact amount of the hyperaccumulated lead. The AAS measurement revealed that the highest intake occurred in the roots while the lowest in the maize ears and in the leaf. It seems there is a particular mechanism that protects the seeds and the leaves in the intake process. (c) 2009 Wiley-Liss, Inc

  2. Determination of lithium isotopes at natural abundance levels by atomic absorption spectrometry

    Science.gov (United States)

    Meier, A.L.

    1982-01-01

    The relationships of the absorption of 6Li and 7Li hollow cathode lamp emissions are used to determine lithium isotopic composition in the natural abundance range of geologic materials. Absorption was found to have a nonlinear dependence upon total lithium concentration and isotopic composition. A method using nonlinear equations to describe the relationship of the absorption of 6Li and 7Li lamp radiation is proposed as a means of calculating isotopic composition that is independent of total lithium concentration.

  3. [Study on determination of eight metal elements in Hainan arecanut leaf by flame atomic absorption spectrophotometry].

    Science.gov (United States)

    Liu, Li-yun; Wang, Ping; Feng, Mei-li; Dong, Zhi-guo; Li, Jie

    2008-12-01

    Arecanut is a sort of palm that is important economic crop for the farmers in Hainan province of China, wherein there are many kinds of metal elements such as K, Ca, Na, Mg, Fe, Mn, Cu, Zn etc. These elements are important nutrition for the growth of arecanut. It is very valuable to study on the content of these metal elements in arecanut leaf in terms of plant nutriology of arecanut. The arecanut leaf in Wangling county, Hainan province of China was sampled by diagonal-field-sampling method. Refering to other plant sample determination by FAAS, the detailed studies are done with different digestion and determination methods. In the present paper the effects of mixed acid of HNO3-HClO4 digestion method on determining the amount of metal elements in the arecanut leaf by FAAS is reported, and another one is incineration digestion method. FAAS method was established for the determination of K, Ca, Mg, Na, Fe, Mn, Cu and Zn The samples were incinerated or heated with HNO3-HClO4 (4:1). In the meantime, the optimum parameters of FAAS and effects of different digestion methods on the results were discussed. The recovery rate of standard addition is 98.36%-102.38% in the first method; RSD is 0.42%-2.328% (n=6); The recovery rate of standard addition is 99.22%-103.72% in the second method; RSD is 0.58%-1.283 (n=6). The metal amount determined by the first method is lower than the second method, the ratio is 0.9703-0.9934. The two methods are satisfied, but the latter is better. It is precise enough to common experiment to use flame atomic absorption spectrophotometry with digestion by incineration If the especially precise experiment is required, the digestion methods with mixed acid of HNO3-HClO4 may be introduced. The paper introduced methods dependable for determination of some metal elements in order to study on some nutrient effects of these metal elements in arecanut.

  4. Study of nonlinear absorption properties of reduced graphene oxide by Z-scan technique

    Science.gov (United States)

    Sreeja, V. G.; Vinitha, G.; Reshmi, R.; Anila, E. I.; Jayaraj, M. K.

    2017-05-01

    Graphene has generated enormous research interest during the last decade due to its significant unique properties and wide applications in the field of optoelectronics and photonics. This research studied the structural and nonlinear absorption properties of reduced graphene oxide (rGO) synthesized by Modified Hummer's method. Structural and physiochemical properties of the rGO were explored with the help of Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy (Raman). Nonlinear absorption property in rGO, was investigated by open aperture Z-scan technique by using a continuous wave (CW) laser. The Z-scan results demonstrate saturable absorption property of rGO with a nonlinear absorption coefficient, β, of -2.62 × 10-4 cm/W, making it suitable for applications in Q switching, generation of ultra-fast high energy pulses in laser cavity and mode lockers.

  5. Study of the roles of chemical modifiers in determining boron using graphite furnace atomic absorption spectrometry and optimization of the temperature profile during atomization.

    Science.gov (United States)

    Yamamoto, Yuhei; Shirasaki, Toshihiro; Yonetani, Akira; Imai, Shoji

    2015-01-01

    The measurement conditions for determining boron using graphite furnace-atomic absorption spectrometry (GF-AAS) were investigated. Differences in the boron absorbance profiles were found using three different commercially available GF-AAS instruments when the graphite atomizers in them were not tuned. The boron absorbances found with and without adjusting the graphite atomizers suggested that achieving an adequate absorbance for the determination of boron requires a sharp temperature profile that overshoots the target temperature during the atomization process. Chemical modifiers that could improve the boron absorbance without the need for using coating agents were tested. Calcium carbonate improved the boron absorbance but did not suppress variability in the peak height. Improvement of boron absorbance was comparatively less using iron nitrate or copper nitrate than using calcium carbonate, but variability in the peak height was clearly suppressed using iron nitrate or copper nitrate. The limit of detection was 0.0026 mg L(-1) when iron nitrate was used. It appears that iron nitrate is a useful new chemical modifier for the quick and simple determination of boron using GF-AAS.

  6. Speciation of platinum in blood plasma and urine by micelle-mediated extraction and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Mortada, Wael I; Hassanien, Mohammed M; El-Asmy, Ahmed A

    2013-10-01

    A highly sensitive and selective technique for the speciation of platinum by cloud point extraction prior to determination by graphite furnace atomic absorption spectrometry (GFAAS) was described. The separation of Pt(II) from Pt(IV) was performed in the presence of 4-(p-chlorophenyl)-1-(pyridin-2-yl)thiosemicarbazide (HCPTS) as chelating agent and Triton X-114 as a non-ionic surfactant. The extraction of Pt(II)-HCPTS complex needs temperature higher than the cloud point temperature of Triton X-114 and pH = 7, while Pt(IV) remains in the aqueous phase. The Pt(II) in the surfactant phase was analyzed by GFAAS, and the concentration of Pt(IV) was calculated by subtraction of Pt(II) from total platinum which was directly determined by GFAAS. The effect of pH, concentration of chelating agent, surfactant, and equilibration temperature were investigated. An enrichment factor of 42 was obtained for the preconcentration of Pt(II) with 50 mL solution. Under the optimum experimental conditions, the calibration curve was linear up to 30 μgL(-1) with detection limit of 0.08 μgL(-1) and the relative standard deviation was 1.8%. No considerable interference was observed due to the presence of coexisting anions and cations. The accuracy of the results was verified by analyzing different spiked samples (tap water, blood plasma and urine). The proposed method was applied to the speciation analysis of Pt in blood plasma and urine with satisfactory results. Copyright © 2013 Elsevier GmbH. All rights reserved.

  7. Characterization of laser damage performance of fused silica using photothermal absorption technique

    Science.gov (United States)

    Wan, Wen; Shi, Feng; Dai, Yifan; Peng, Xiaoqiang

    2017-06-01

    The subsurface damage and metal impurities have been the main laser damage precursors of fused silica while subjected to high power laser irradiation. Light field enhancement and thermal absorption were used to explain the appearance of damage pits while the laser energy is far smaller than the energy that can reach the intrinsic threshold of fused silica. For fused silica optics manufactured by magnetorheological finishing or advanced mitigation process, no scratch-related damage site occurs can be found on the surface. In this work, we implemented a photothermal absorption technique based on thermal lens method to characterize the subsurface defects of fused silica optics. The pump beam is CW 532 nm wavelength laser. The probe beam is a He-Ne laser. They are collinear and focused through the same objective. When pump beam pass through the sample, optical absorption induces the local temperature rise. The lowest absorptance that we can detect is about the order of magnitude of 0.01 ppm. When pump beam pass through the sample, optical absorption induces the local temperature rise. The photothermal absorption value of fused silica samples range from 0.5 to 10 ppm. The damage densities of the samples were plotted. The damage threshold of samples at 8J/cm2 were gived to show laser damage performance of fused silica.The results show that there is a strong correlation between the thermal absorption and laser damage density. The photothermal absorption technique can be used to predict and evaluate the laser damage performance of fused silica optics.

  8. 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

  9. 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

  10. Accelerating all-atom MD simulations of lipids using a modified virtual-sites technique

    DEFF Research Database (Denmark)

    Loubet, Bastien; Kopec, Wojciech; Khandelia, Himanshu

    2014-01-01

    We present two new implementations of the virtual sites technique which completely suppresses the degrees of freedom of the hydrogen atoms in a lipid bilayer allowing for an increased time step of 5 fs in all-atom simulations of the CHARMM36 force field. One of our approaches uses the derivation ...

  11. A quality control technique based on UV-VIS absorption spectroscopy for tequila distillery factories

    Science.gov (United States)

    Barbosa Garcia, O.; Ramos Ortiz, G.; Maldonado, J. L.; Pichardo Molina, J.; Meneses Nava, M. A.; Landgrave, Enrique; Cervantes, M. J.

    2006-02-01

    A low cost technique based on the UV-VIS absorption spectroscopy is presented for the quality control of the spirit drink known as tequila. It is shown that such spectra offer enough information to discriminate a given spirit drink from a group of bottled commercial tequilas. The technique was applied to white tequilas. Contrary to the reference analytic methods, such as chromatography, for this technique neither special personal training nor sophisticated instrumentations is required. By using hand-held instrumentation this technique can be applied in situ during the production process.

  12. Combined laser calorimetry and photothermal technique for absorption measurement of optical coatings.

    Science.gov (United States)

    Li, Bincheng; Blaschke, Holger; Ristau, Detlev

    2006-08-10

    To the best of our knowledge, a combined sensitive technique employing both laser calorimetry and a surface thermal lens scheme for measuring absorption values of optical coatings is presented for the first time. Laser calorimetric and pulsed surface thermal lens signals are simultaneously obtained with a highly reflecting UV coating sample irradiated at 193 nm. The advantages and potential applications of the combined technique and the experimental factors limiting the measurement sensitivity are discussed.

  13. Immobilized stearic acid as a new sorbent for on-line preconcentration and determination of lead by flow injection flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Dadfarnia Shayessteh

    2006-01-01

    Full Text Available The present study examines the possibility of immobilization of stearic acid on microcrystalline naphthalene for preparation of microcolumn and evaluation of its potential for adsorption and preconcentration of trace amounts of metal ions. It was found that this sorbent has high affinity for lead. Consequently, a rapid on-line preconcentration technique for the determination of lead by Flow Injection Flame Atomic Absorption Spectrometry had been devised. Preconcentration was based on accumulation of analyte on immobilized stearic acid microcolumn and subsequent elution by injection of a small volume of nitric acid (250 µL of 1 mol L-1. A sample volume of 20 mL resulted in a preconcentration factor of 84, and relative standard deviations for solutions containing 40 and 200 µg L-1 were 5.1 and 1.2%, respectively. The procedure was applied to tap water, river water, sea water, apple juice, beet leaf, urine, and certified stainless steel. The accuracy was proved by performing recovery experiments, Graphite Furnace Atomic Absorption Spectrometry measurements, and analysis of a stainless steel certified reference material.

  14. Estimation of lead, cadmium and nickel content by means of Atomic Absorption Spectroscopy in dry fruit bodies of some macromycetes growing in Poland. II.

    Directory of Open Access Journals (Sweden)

    Jan Grzybek

    2014-08-01

    Full Text Available The content of lead, cadmium, and nickel in dry fruit bodies of 34 species of macromyoetes collected in Poland from 72 natural babitats by means of Atomic Absorption Spectroscopy (AAS was estimated.

  15. Photothermal self-phase-modulation technique for absorption measurements on high-reflective coatings.

    Science.gov (United States)

    Steinlechner, Jessica; Jensen, Lars; Krüger, Christoph; Lastzka, Nico; Steinlechner, Sebastian; Schnabel, Roman

    2012-03-10

    We propose and demonstrate a new measurement technique for the optical absorption of high-reflection coatings. Our technique is based on photothermal self-phase modulation and exploits the deformation of cavity Airy peaks that occurs due to coating absorption of intracavity light. The mirror whose coating is under investigation needs to be the input mirror of a high-finesse cavity. Our example measurements were performed on a high-reflection SiO2-Ta2O5 coating in a three-mirror ring-cavity setup at a wavelength of 1064 nm. The optical absorption of the coating was determined to be α=(23.9±2.0)·10(-6) per coating. Our result is in excellent agreement with an independently performed laser calorimetry measurement that gave a value of α=(24.4±3.2)·10(-6) per coating. Since the self-phase modulation in our coating-absorption measurement affects mainly the propagation through the cavity input mirror, our measurement result is practically uninfluenced by the optical absorption of the other cavity mirrors.

  16. A New Cross-Shaped Graphite Furnace with Ballast Body for Reduction of Interferences in Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    A. A. Asweisi

    2010-01-01

    Full Text Available A new crossed graphite furnace for atomic absorption spectrometry (GFAAS was designed and installed in heated graphite atomizer (HGA500 combined with Perkin-Elmer spectrometer (AAS1100. The Tungsten ballast body was inserted inside one part of the crossed furnace in a way perpendicular to light path. The analyzed sample was injected manually on the ballast body inside the cross and pushed into the measuring zone using the original inner and additional purge gas. The sample was adsorbed strongly on the ballast and evaporated and transferred with different rates at different temperatures during the temperature program allowing the separation of analyte and matrix signals. Analysis of middle volatile element such as copper and manganese in standard urine sample (seronorm 2525 showed complete separation of analyte and background signals with good sensitivity and repeatability.

  17. A photon counting and a squeezing measurement method by the exact absorption and dispersion spectrum of Λ-type Atoms.

    Science.gov (United States)

    Naeimi, Ghasem; Alipour, Samira; Khademi, Siamak

    2016-01-01

    Recently, the master equations for the interaction of two-mode photons with a three-level Λ-type atom are exactly solved for the coherence terms. In this paper the exact absorption spectrum is applied for the presentation of a non-demolition photon counting method, for a few number of coupling photons, and its benefits are discussed. The exact scheme is also applied where the coupling photons are squeezed and the photon counting method is also developed for the measurement of the squeezing parameter of the coupling photons.

  18. Determination of total selenium in nutritional supplements and selenised yeast by Zeeman-effect graphite furnace atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Ekelund, J.

    1989-01-01

    A method for the determination of total selenium in nutritional supplements and selenised yeast is described. The samples were ashed in nitric acid. Hydrochloric acid was used to prevent precipitation of, in particular, iron salts. After appropriate dilutions, the selenium was determined by Zeeman......-effect background corrected graphite furnace atomic absorption spectrometry. A furnace ashing step at 1100 °C was necessary in order to obtain a total recovery of selenium when present in the organic form. Palladium nitrate-magnesium nitrate was used as a matrix modifier. Independent methods were used to determine...

  19. [Column chromatographic preconcentration of trace copper in natural water using dithizone supported on naphthalene and determined by atomic absorption spectrometer].

    Science.gov (United States)

    He, H; Ju, Z

    1998-12-01

    In this paper a column chromatographic preconcentration method using dithizone supported on naphthalene for copper in natural water is provided. The dissolving reagent is dimethylformamide (DMF). The dissolving solution is determined by atomic absorption spectrometer. The effect of pH, the flow rate of water samples, the choice of dissolving reagent, the effect of diverse ions were studied. RSD is 2.3%. The recoveries for the added standard are between 96%-103%. This method was applied to determined trace copper in natural water samples and standard water samples with satisfactory results.

  20. Determination of platinum and palladium in environmental samples by graphite furnace atomic absorption spectrometry after separation on dithizone sorbent.

    Science.gov (United States)

    Chwastowska, J; Skwara, W; Sterlińska, E; Pszonicki, L

    2004-09-08

    A graphite furnace atomic absorption method of platinum and palladium determination after their separation from environmental samples has been presented. The samples were digested by aqua regia and the analyte elements were separated on the dithizone sorbent. The procedure of sorbent preparation was described and their properties were established. Two various procedures of elution by thiourea and concentrated nitric acid were described and discussed. The low limit of detection was established as 1ngg(-1) for platinum and 0.2ngg(-1) for palladium. There was also investigated the behaviour of platinum and palladium introduced into the soil in various chemical forms.

  1. Arsenic speciation by hydride generation-quartz furnace atomic absorption spectrometry. Optimization of analytical parameters and application to environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Molenat, N.; Astruc, A.; Holeman, M.; Pinel, R. [Laboratoire de Chimie Analytique Bioinorganique et Environnement, Dept. de Chimie, Faculte des Sciences et Techniques, 64 - Pau (France); Maury, G. [Montpellier-2 Univ., 34 (France). Dept. de Chimie Organique Fine

    1999-11-01

    Analytical parameters of hydride generation, trapping, gas chromatography and atomic absorption spectrometry detection in a quartz cell furnace (HG/GC/QFAAS) device have been optimized in order to develop an efficient and sensitive method for arsenic compounds speciation. Good performances were obtained with absolute detection limits in the range of 0.1 - 0.5 ng for arsenite, arsenate, mono-methyl-arsonic acid (MMAA), dimethyl-arsinic acid (DMAA) and trimethyl-arsine oxide (TMAO). A pH selective reduction for inorganic arsenic speciation was successfully reported. Application to the accurate determination of arsenic compounds in different environmental samples was performed. (authors)

  2. Graphite furnace atomic absorption spectrophotometry--a novel method to quantify blood volume in experimental models of intracerebral hemorrhage.

    Science.gov (United States)

    Kashefiolasl, Sepide; Foerch, Christian; Pfeilschifter, Waltraud

    2013-02-15

    Intracerebral hemorrhage (ICH) accounts for 10% of all strokes and has a significantly higher mortality than cerebral ischemia. For decades, ICH has been neglected by experimental stroke researchers. Recently, however, clinical trials on acute blood pressure lowering or hyperacute supplementation of coagulation factors in ICH have spurred an interest to also design and improve translational animal models of spontaneous and anticoagulant-associated ICH. Hematoma volume is a substantial outcome parameter of most experimental ICH studies. We present graphite furnace atomic absorption spectrophotometric analysis (AAS) as a suitable method to precisely quantify hematoma volumes in rodent models of ICH. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Determination of Copper-Based Fungicides by Flame Atomic Absorption Spectrometry Using Digestion Procedure with Sulfuric and Nitric Acid

    Directory of Open Access Journals (Sweden)

    Jelena Milinović

    2007-01-01

    Full Text Available Copper-based fungicides can be effectively digested by treatment with a mixture of concentrated sulfuric and nitric acid in exactly 15 minutes for the rapid determination via copper using flame atomic absorption spectrometry (AAS. Under optimum conditions, the results of copper fungicide analysis were consistent to those obtained by the AOAC’s recommended method. Recovery values ranged from 98.63 to 103.40%. Relative standard deviation values are lower than 2%. The proposed digestion procedure applied for determination of copper ranged from 100 to 594 g Cu kg-1 in different commercial fungicideproducts.

  4. Spectrum sensing of trace C(2)H(2) detection in differential optical absorption spectroscopy technique.

    Science.gov (United States)

    Chen, Xi; Dong, Xiaopeng

    2014-09-10

    An improved algorithm for trace C(2)H(2) detection is presented in this paper. The trace concentration is accurately calculated by focusing on the absorption spectrum from the frequency domain perspective. The advantage of the absorption spectroscopy frequency domain algorithm is its anti-interference capability. First, the influence of the background noise on the minimum detectable concentration is greatly reduced. Second, the time-consuming preprocess of spectra calibration in the differential optical absorption spectroscopy technique is skipped. Experimental results showed the detection limit of 50 ppm is achieved at a lightpath length of 0.2 m. This algorithm can be used in real-time spectrum analysis with high accuracy.

  5. Determination of Chlorine in Milk via Molecular Absorption of SrCl Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-07-20

    Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1).

  6. Comparison of three optical diagnostic techniques for the measurement of boron atom density in a H2/B2H6 microwave plasma

    Science.gov (United States)

    Aubert, X.; Duluard, C. Y.; Sadeghi, N.; Gicquel, A.

    2017-11-01

    Three different optical diagnostic techniques have been used to measure the density of boron atoms in a microwave generated H2/B2H6 plasma of a diamond deposition reactor. These techniques are: optical emission intensity ratio of doublet 249.677 and 249.772 nm boron lines (OEIRD), laser induced fluorescence on 208.96 nm line (LIF) and resonance absorption on 249.772 nm line (RA) with a boron hollow cathode lamp (HCL) as light source. LIF results point to an important variation of the boron atom density with the distance from the substrate, in contradiction with OEIRD which indicates an almost constant density. RA measurements show a stronger absorption when the probe light from the HCL crosses the reactor outside the bright plasma core region than when it goes through the plasma core. This indicates a larger boron atom density in the volume surrounding the plasma core than inside it. As the plasma is not homogeneous, in the sense that the plasma induced emission is confined inside the plasma core but the ground state boron atoms are also present outside this region, the OEIRD method cannot be applied to this plasma. These experimental results question the simulation results of H2/B2H6 microwave plasma which predicted a fast decay of the boron atom density outside the plasma core.

  7. Improved multi-element measurement of absorption via the fecal monitoring technique

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, R.S.; Gibson, I.L.; Weber, C.E.; Atkinson, S.A.

    1986-03-01

    The fecal monitoring technique for measuring the absorption of Mn, Se and Fe was studied in eight piglets using high resolution gamma spectrometry. Four day old piglets were fed a complete liquid diet for five days prior to the administration of an isotope dose (/sup 75/Se, /sup 54/Mn, /sup 59/Fe) equilibrated with the milk feeding. /sup 51/CrCl/sub 3/ was used as a fecal marker. Subsequently stool and urine samples were collected daily for 15-21 days. Following counting, the % fecal excretion of the administered dose was calculated. As 0 to 33% of the administered /sup 51/CrCl/sub 3/ was absorbed this fecal marker is inappropriate for piglets. Results indicate that endogenous excretion for each of the isotopes was not constant but decreased exponentially with time. An improved method for calculating the endogenous excretion was therefore developed. This method is based on the pattern of endogenous excretion in comparable piglets injected intravenously with the same isotopes, and on the level of endogenous excretion in the orally fed animals in the post-absorptive phase of excretion. These findings have important implications for the estimation of endogenous excretion in future fecal monitoring absorption studies. Previous results using the latter technique have frequently underestimated true absorption.

  8. Saturated-absorption spectroscopy revisited: atomic transitions in strong magnetic fields (>20  mT) with a micrometer-thin cell.

    Science.gov (United States)

    Sargsyan, A; Tonoyan, A; Mirzoyan, R; Sarkisyan, D; Wojciechowski, A M; Stabrawa, A; Gawlik, W

    2014-04-15

    The existence of crossover resonances makes saturated-absorption (SA) spectra very complicated when external magnetic field B is applied. It is demonstrated for the first time, to the best of our knowledge, that the use of micrometric-thin cells (MTCs, L≈40  μm) allows application of SA for quantitative studies of frequency splitting and shifts of the Rb atomic transitions in a wide range of external magnetic fields, from 0.2 up to 6 kG (20-600 mT). We compare the SA spectra obtained with the MTC with those obtained with other techniques and present applications for optical magnetometry with micrometer spatial resolution and a broadly tunable optical frequency lock.

  9. Computational techniques in tribology and material science at the atomic level

    Science.gov (United States)

    Ferrante, J.; Bozzolo, G. H.

    1992-01-01

    Computations in tribology and material science at the atomic level present considerable difficulties. Computational techniques ranging from first-principles to semi-empirical and their limitations are discussed. Example calculations of metallic surface energies using semi-empirical techniques are presented. Finally, application of the methods to calculation of adhesion and friction are presented.

  10. Mercury speciation in sea food by flow injection cold vapor atomic absorption spectrometry using selective solid phase extraction.

    Science.gov (United States)

    Vereda Alonso, E; Siles Cordero, M T; García de Torres, A; Cañada Rudner, P; Cano Pavón, J M

    2008-10-19

    An on-line inorganic and organomercury species separation, preconcentration and determination system consisting of cold vapor atomic absorption spectrometry (CV-AAS or CV-ETAAS) coupled to a flow injection (FI) method was studied. The inorganic mercury species was retained on a column (i.d., 3 mm; length 3 cm) packed to a height of 0.7 cm with a chelating resin aminopropyl-controlled pore glass (550 A) functionalized with [1,5-bis (2 pyridyl)-3-sulphophenyl methylene thiocarbonohydrazyde] placed in the injection valve of a simple flow manifold. Methylmercury is not directly determined. Previous oxidation of the organomercurial species permitted the determination of total mercury. The separation of mercury species was obtained by the selective retention of inorganic mercury on the chelating resin. The difference between total and inorganic mercury determined the organomercury content in the sample. The inorganic mercury was removed on-line from the microcolumn with 6% (m/v) thiourea. The mercury cold vapor generation was performed on-line with 0.2% (m/v) sodium tethrahydroborate and 0.05% (m/v) sodium hydroxide as reducing solution. The determination was performed using CV-AAS and CV-ETAAS, both approaches have been used and compared for the speciation of mercury in sea food. A detection limit of 10 and 6 ng l(-1) was achieved for CV-AAS and CV-ETAAS, respectively. The precision for 10 replicate determinations at the 1 microg l(-1) Hg level was 3.5% relative standard deviation (R.S.D.), calculated from the peak heights obtained. Both approaches were validated with the use of two certified reference materials and by spiking experiments. By analyzing the two biological certified materials, it was evident that the difference between the total mercury and inorganic mercury corresponds to methylmercury. The concentrations obtained by both techniques were in agreement with the certified values or with differences of the certified values for total Hg(2+) and CH(3)Hg

  11. An Insight Into the Two Costing Technique: Absorption Costing and Marginal Costing

    Directory of Open Access Journals (Sweden)

    Mariam Nawaz

    2013-02-01

    Full Text Available This paper will investigate the controversy that is innate between the two costing techniques; Absorption Costing and Marginal Costing and would throw light on which costing technique better serves its purpose in helping management for decision making process and if Marginal Costing technique is concluded as better technique then why it should not be used for external reporting purpose. This paper will only crystallize and highlight the issues descriptively and will not resolve the issues that are inherent between the two costing techniques. The unique thing about this paper is that it is in favor of treating fixed cost as product cost that is it is supporting the advocates of Absorption Costing Technique but it is against to consider profit as a function of production rather it believes that profit should only be considered as function of sales for stock valuation and to help management in decision making process that is, regarding this point it is supporting advocates of Marginal Costing.

  12. 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.

  13. Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.

    Science.gov (United States)

    Saracoglu, Sibel; Soylak, Mustafa; Cabuk, Dilek; Topalak, Zeynep; Karagozlu, Yasemin

    2012-01-01

    The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.

  14. Determination of Sodium, Potassium, Magnesium, and Calcium Minerals Level in Fresh and Boiled Broccoli and Cauliflower by Atomic Absorption Spectrometry

    Science.gov (United States)

    Nerdy

    2018-01-01

    Vegetables from the cabbage family vegetables consumed by many people, which is known healthful, by eaten raw, boiled, or cooked (stir fry or soup). Vegetables like broccoli and cauliflower contain vitamins, minerals, and fiber. This study aims to determine the decrease percentage of sodium, potassium, magnesium, and calcium minerals level caused by boiled broccoli and cauliflower by atomic absorption spectrometry. Boiled broccoli and cauliflower prepared by given boiled treatment in boiling water for 3 minutes. Fresh and boiled broccoli and cauliflower carried out dry destruction, followed by quantitative analysis of sodium, potassium, magnesium, and calcium minerals respectively at a wavelength of 589.0 nm; 766.5 nm; 285.2 nm; and 422.7 nm, using atomic absorption spectrometry methods. After the determination of the sodium, potassium, magnesium, and calcium minerals level followed by validation of analytical methods with accuracy, precision, linearity, range, limit of detection (LOD), and limit of quantitation (LOQ) parameters. Research results show a decrease in the sodium, potassium, magnesium, and calcium minerals level in boiled broccoli and cauliflower compared with fresh broccoli and cauliflower. Validation of analytical methods gives results that spectrometry methods used for determining sodium, potassium, magnesium, and calcium minerals level are valid. It concluded that the boiled gives the effect of decreasing the minerals level significantly in broccoli and cauliflower.

  15. Direct determination of Cd, Cu and Pb in wines and grape juices by thermospray flame furnace atomic absorption spectrometry.

    Science.gov (United States)

    Schiavo, Daniela; Neira, José Y; Nóbrega, Joaquim A

    2008-09-15

    The applicability of thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) was evaluated for direct determination of Cu, Cd and Pb in wines and grape juices. The developed procedure does not require preliminary acid digestion of the samples. The optimum conditions for determination of Cu, Cd and Pb in wines were studied and the performance was compared to those typically obtained by flame atomic absorption spectrometry (FAAS). A sample volume of 150 microL was introduced into a heated nickel tube at a flow rate of 0.54 mLmin(-1) and 0.14 molL(-1) HNO(3) was used as sample carrier flowing at 2.5 mLmin(-1) for determining all analytes. The effect of ethanol concentrations on Cu, Cd and Pb absorbance signals were studied. All determinations were carried out by adopting optimized conditions and quantification was based on the standard additions method. Limits of detection (LOD) of 12.9, 1.8 and 5.3 microgL(-1) (n=14) for Cu, Cd and Pb, respectively, were obtained for wine samples (3sigma(blank)/slope, n=14). Relative standard deviations (R.S.D., %) of 2.7, 2.1 and 2.6 for Cu, Cd and Pb, were obtained (n=6) for wine samples. The values determined for grape juice samples were similar to these ones. The analytical throughput was 45 determinations h(-1) and accuracy was checked by addition-recovery experiments.

  16. Nonchromatographic speciation of selenium in edible oils using dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    López-García, Ignacio; Vicente-Martínez, Yesica; Hernández-Córdoba, Manuel

    2013-10-02

    A methodology for the nonchromatographic separation of the main selenium species present in edible oils is presented. Dispersive liquid-liquid microextraction is used to extract inorganic selenium (iSe), seleno-L-cystine (SeCys₂), seleno-L-methionine (SeMet), and selenocystamine (SeCM) into a slightly acidic aqueous medium. The selenium total (tSe) content is measured in the extracts by electrothermal atomic absorption spectrometry. By repeating the microextraction stage using an ionic liquid instead of water, the sum of SeCys₂, SeMet, and SeCM is obtained and iSe is calculated by difference. The detection limit is 0.03 ng of Se per gram of oil. The fractionation of the edible oils by solid phase extraction followed by dispersive liquid-liquid extraction and atomic absorption measurement also permits speciation of iSe to be carried out. Data for tSe and iSe levels of 15 samples of different origin are given.

  17. Contents of cadmium, mercury and lead in fish from the Atlantic sea (Morocco) determined by atomic absorption spectrometry.

    Science.gov (United States)

    Chahid, Adil; Hilali, Mustapha; Benlhachimi, Abdeljalil; Bouzid, Taoufiq

    2014-03-15

    As a part of a specific monitoring program, lead (Pb) cadmium (Cd) and mercury (Hg) concentrations in important species of fish from various fishing ports of the southern Kingdom of Morocco (Sardina pilchardus, Scomber scombrus, Plectorhinchus mediterraneus, Trachurus trachurus, Octopus vulgaris, Boops boops, Sarda sarda, Trisopterus capelanus, and Conger conger) were investigated by the Moroccan Reference Laboratory (NRL) for trace elements in foodstuffs of animal origin. The samples were analysed for lead and cadmium by a graphite furnace atomic absorption spectrometry (GFAAS); and for mercury by cold vapour atomic absorption spectrometry (CVAAS). The results were expressed as μg/g of wet weight (w/w). The levels of Cd, Pb and Hg in muscles of fish were 0.009-0.036, 0.013-0.114 and 0.049-0.194 μg/g, respectively. The present study showed that different metals were present in the sample at different levels but within the maximum residual levels prescribed by the EU for the fish and shellfish from these areas, in general, should cause no health problems for consumers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Colorimetric and atomic absorption spectrometric determination of mucolytic drug ambroxol through ion-pair formation with iron and thiocyanate.

    Science.gov (United States)

    Levent, Abdulkadir; Sentürk, Zühre

    2010-09-01

    Colorimetric and atomic absorption spectrometric methods have been developed for the determination of mucolytic drug Ambroxol. These procedures depend upon the reaction of iron(III) metal ion with the drug in the presence of thiocyanate ion to form stable ion-pair complex which extractable chloroform. The red-coloured complex was determined either colorimetrically at 510 nm or by indirect atomic absorption spectrometry (AAS) via the determination of the iron content in the formed complex. The optimum experimental conditions for pH, concentrations of Fe(3+) and SCN(-), shaking time, phase ratio, and the number of extractions were determined. Under the proposed conditions, linearity was obeyed in the concentration ranges 4.1x10(-6) - 5.7x10(-5) M (1.7-23.6 µg mL(-1)) using both methods, with detection limits of 4.6x10(-7) M (0.19 µg mL(-1)) for colorimetry and 1.1x10(-6) M (0.46 µg mL(-1)) for AAS. The proposed methods were applied for the determination of Ambroxol in tablet dosage forms. The results obtained were statistically analyzed and compared with those obtained by applying the high-performance liquid chromatographic method with diode-array detection.

  19. Surfactant/oil/water system for the determination of selenium in eggs by graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Ieggli, C.V.S. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Bohrer, D. [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil)], E-mail: ndenise@quimica.ufsm.br; Noremberg, S.; Nascimento, P.C. do; Carvalho, L.M. de [Departamento de Quimica, Avenida Roraima, 1000, Universidade Federal de Santa Maria, CEP 97110-970, Santa Maria, RS (Brazil); Vieira, S.L.; Reis, R.N. [Faculdade de Agronomia, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves, 7712, CEP 90540-000, Porto Alegre (Brazil)

    2009-06-15

    An oil-in-water formulation has been optimized to determine trace levels of selenium in whole hen eggs by graphite furnace atomic absorption spectrometry. This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures. Graphite furnace atomic absorption spectrometric (GF AAS) measurement was carried out using standard addition calibration and Pd as a modifier. The precision, expressed as relative standard deviation, was better than 5% and the limit of detection was 1 {mu}g L{sup - 1}. The validation of the method was performed against a standard reference material Whole Egg Powder (RM 8415), and the measured Se corresponded to 95.2% of the certified value. The method was used for the determination of the Se level in eggs from hens treated with Se dietary supplements. Inorganic and organic Se sources were added to hen feed. The Se content of eggs was higher when hens were fed with organic Se compared to the other treatments. The proposed method, including sample emulsification for subsequent Se determination by GF AAS has proved to be sensitive, reproducible, simple and economical.

  20. Simultaneous determination of rhodium and ruthenium by high-resolution continuum source graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Zambrzycka-Szelewa, Elżbieta; Lulewicz, Marta; Godlewska-Żyłkiewicz, Beata

    2017-07-01

    In the present paper a fast, simple and sensitive analytical method for simultaneous determination of rhodium and ruthenium by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) was developed. Among six pairs of absorption atomic lines of Rh and Ru, which are close enough to enable their simultaneous detection, two pairs were selected for further studies. Best results were obtained for measurements of the resonance line of rhodium at 343.489 nm and the adjacent secondary line of ruthenium at 343.674 nm (23% intensity of this line). For evaluated lines, the absorbance values were obtained using three pixels. The pyrolysis and atomization temperatures were 1200 °C and 2600 °C, respectively. Under these conditions the limits of detection achieved for Rh and Ru were found to be 1.0 μg L- 1 and 1.9 μg L- 1, respectively. The characteristic mass was 12.9 pg for Rh and 71.7 pg for Ru. Repeatability of the results expressed as a relative standard deviation was typically below 6%. The trueness of the method was confirmed by analysis of the certified reference material - platinum ore (SARM 76). The recovery of Rh and Ru from the platinum ore was 93.0 ± 4.6% and 90.1 ± 2.5%, respectively. The method was successfully applied to the direct simultaneous determination of trace amounts of rhodium and ruthenium in spiked river water, road runoff, and municipal sewage. Separation of interfering matrix on cation exchange resin was required before analysis of road dust and tunnel dust (CW-7) by HR-CS GFAAS.

  1. Application of Plackett-Burman and Doehlert designs for optimization of selenium analysis in plasma with electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    El Ati-Hellal, Myriam; Hellal, Fayçal; Hedhili, Abderrazek

    2014-10-01

    The aim of this study was the optimization of selenium determination in plasma samples with electrothermal atomic absorption spectrometry using experimental design methodology. 11 variables being able to influence selenium analysis in human blood plasma by electrothermal atomic absorption spectrometry (ETAAS) were evaluated with Plackett-Burman experimental design. These factors were selected from sample preparation, furnace program and chemical modification steps. Both absorbance and background signals were chosen as responses in the screening approach. Doehlert design was used for method optimization. Results showed that only ashing temperature has a statistically significant effect on the selected responses. Optimization with Doehlert design allowed the development of a reliable method for selenium analysis with ETAAS. Samples were diluted 1/10 with 0.05% (v/v) TritonX-100+2.5% (v/v) HNO3 solution. Optimized ashing and atomization temperatures for nickel modifier were 1070°C and 2270°C, respectively. A detection limit of 2.1μgL(-1) Se was obtained. Accuracy of the method was checked by the analysis of selenium in Seronorm™ Trace element quality control serum level 1. The developed procedure was applied for the analysis of total selenium in fifteen plasma samples with standard addition method. Concentrations ranged between 24.4 and 64.6μgL(-1), with a mean of 42.6±4.9μgL(-1). The use of experimental designs allowed the development of a cheap and accurate method for selenium analysis in plasma that could be applied routinely in clinical laboratories. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  2. Interference of nitrite and nitrogen dioxide on mercury and selenium determination by chemical vapor generation atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Nunes, Dayana [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900, Santa Maria, RS (Brazil); Pereira dos Santos, Eliane Pereira [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900, Santa Maria, RS (Brazil); Barin, Juliano Smanioto [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900, Santa Maria, RS (Brazil); Mortari, Sergio Roberto [Curso de Ciencias Farmaceuticas, Centro Universitario Franciscano, UNIFRA, 97010-032, Santa Maria, RS (Brazil); Dressler, Valderi Luiz [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900, Santa Maria, RS (Brazil); Moraes Flores, Erico Marlon de [Departamento de Quimica, Universidade Federal de Santa Maria, UFSM, 97105-900, Santa Maria, RS (Brazil)]. E-mail: flores@quimica.ufsm.br

    2005-06-30

    In this study, a systematic investigation was performed concerning the interference of nitrogen oxides on the determination of selenium and mercury by hydride generation atomic absorption spectrometry (HG AAS) and cold vapor atomic absorption spectrometry (CV AAS). The effect of nitrate, nitrite and NO{sub 2} dissolved in the condensed phase was evaluated. No effect of NO{sub 3} {sup -} on Se and Hg determination was observed up to 100 mg of sodium nitrate added to the reaction vessel. The Se signal was reduced by about 80% upon the addition of 6.8 mg NO{sub 2} {sup -}. For Hg, no interference of nitrite was observed up to 20 mg of NO{sub 2} {sup -}. A complete suppression of the Se signal was observed when gaseous NO{sub 2} was introduced into analytical solutions. For Hg, a signal decrease between 8 and 13% occurred. For Se, bubbling argon or heating the solution was not able to recover the original absorbance values, whereas Hg signals were recovered with these procedures. When gaseous NO{sub 2} was passed directly into the atomizer, Se signals decreased similarly to when NO{sub 2} was bubbled in analytical solutions. The addition of urea, hydroxylamine hydrochloride and sulfamic acid (SA) was investigated to reduce the NO{sub 2} effect in sample digests containing residual NO{sub 2}, but only SA was effective in reducing the interference. Based on the results, it is possible to propose the use of SA to prevent interferences in Se and Hg determinations by HG AAS and CV AAS, respectively.

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

    Science.gov (United States)

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

    2012-07-01

    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.

  4. Thermo-Mechanical Properties of Alumina Films Created Using the Atomic Layer Deposition Technique

    Science.gov (United States)

    2010-01-01

    develop in chemical vapor deposited ( CVD ) films within the first 10–30nm of material, owing to the process of island formation and coalescence [44–46...George, ZnO /Al2O3 nanolaminates fabricated by atomic layer deposition: growth and surface roughness measurements, Thin Solid Films 414 (2002) 43–55. [81...homepage: www.e lsev ier .com/ locate /sna Thermo-mechanical properties of alumina films created using the atomic layer deposition technique David C

  5. Determination of toxic elements in plastics from waste electrical and electronic equipment by slurry sampling electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Santos, Mirian C; Nóbrega, Joaquim A; Baccan, Nivaldo; Cadore, Solange

    2010-06-15

    Cadmium, chromium, lead and antimony were determined in slurries prepared using pulverized samples of personal computers and mobile phones dispersed in dimethylformamide medium. Determinations were carried out by electrothermal atomic absorption spectrometry (ETAAS) using a graphite furnace atomic absorption spectrometer. The optimization of the experimental conditions (chemical modifier, pyrolysis time, pyrolysis temperature and atomization temperatures) was accomplished by evaluating pyrolysis and atomization curves. Optimization was also used to determine the temperatures corresponding to the best sensitivities and the lowest background signals. The pyrolysis temperatures were fixed at 600 degrees C (for Cd), 700 degrees C (for Pb), 1100 degrees C (for Sb), and 1200 degrees C (for Cr); atomization temperatures were established as 1400 degrees C (for Cd), 1300 degrees C (for Pb), 1900 degrees C (for Sb), and 2300 degrees C (for Cr), and the chemical modifier (50microg NH(4)H(2)PO(4)+3microg Mg(NO(3))(2) was used for Cd and Pb while 5microg Pd+3microg Mg(NO(3))(2) was used for Sb). The use of a chemical modifier for Cr determination was not necessary. The characteristic masses were 1.9pg for Cd, 32.3pg for Pb, 54.1pg for Sb, and 9.1pg for Cr. Calibration was performed using standard additions in a range of 5-20microgL(-1) for Cd, 5-30microgL(-1) for Cr, 12.5-50microgL(-1) for Pb, and 25-100microgL(-1) for Sb with linear correlation coefficients higher than 0.99. Limits of detection were 0.9, 1.4, 6.8, and 2.9microgL(-1) for Cd, Pb, Sb, and Cr, respectively. The results indicate that recoveries for all metals agreed at a 95% confidence level when a paired t-test was applied and presented good precision. The accuracy of the proposed method was evaluated by addition-recovery experiments, showing results in the 96-112% range, and also by comparison of the results using Student's t-test with another method developed using ETAAS for digested samples. Analyte

  6. A versatile microcomputer interface and peripheral devices: An application in deuterium lamp background correction graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Gökmen, A.; Yalcin, S.

    1992-01-01

    A versatile interface card for Apple IIe computer and various peripheral devices are designed to control instruments which generates transient signals like in graphite furnace atomic spectrometer. The interface card consists of a multiplexed analog-to-digital converter, a digital-to-analog converter, and a timer/counter chip. The timer/counter chip with 16 built-in registers can be programmed in many modes which provides a time base for real-time measurements. A stepper motor runs under the control of timer/counter chip independent of computer. A light chopper connected to the stepper motor is controlled easily by computer. A dual high-voltage switch can modulate dc light sources under computer control. This system is applied to D2-lamp background correction graphite furnace atomic absorption spectrometer. The D2 lamp is chopped by a mechanical chopper driven by a stepper motor and a hollow cathode lamp is modulated electronically. The data acquisition program is written in machine language and synchronization between light sources and computer is provided by chopper position signal through the interrupts. A sampling rate of 16 during a signal period at 50-Hz chopping frequency is found to be the optimum value. A large number of data collected during atomization period is compressed in machine code. This saved storage space and analysis time.

  7. XUV Transient Absorption Spectroscopy: Probing Laser-Perturbed Dipole Polarization in Single Atom, Macroscopic, and Molecular Regimes

    Directory of Open Access Journals (Sweden)

    Chen-Ting Liao

    2017-03-01

    Full Text Available We employ an extreme ultraviolet (XUV pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6 molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms,includinglaser-inducedphase(LIP,time-varying(ACStarkshift,quantumpathinterference, and laser-induced continuum structure. In the case of dense helium targets, we discuss nonlinear macroscopic propagation effects pertaining to LIP and resonant pulse propagation, which accoun tfor the appearance of new spectral features in transient lineshapes. We then use tunable NIR photons to demonstrate the wavelength dependence of the transient laser induced effects. In the case of molecular polarization experiment in SF6, we show suppression of XUV photoabsorption corresponding to inter-valence transitions in the presence of a strong NIR field. In each case, the temporal evolution of transient absorption spectra allows us to observe and understand the transient laser induced modifications of the electronic structure of atoms and molecules.

  8. Direct determination of cadmium in Orujo spirit samples by electrothermal atomic absorption spectrometry: Comparative study of different chemical modifiers

    Energy Technology Data Exchange (ETDEWEB)

    Vilar Farinas, M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Barciela Garcia, J. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Garcia Martin, S. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Pena Crecente, R. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Herrero Latorre, C. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)]. E-mail: cherrero@lugo.usc.es

    2007-05-22

    In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO{sub 3}){sub 2} and (NH{sub 4})H{sub 2}PO{sub 4}-Mg(NO{sub 3}){sub 2}] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 {mu}g L{sup -1}), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged

  9. Novel Cross-Band Relative Absorption (CoBRA) technique For Measuring Atmospheric Species

    Science.gov (United States)

    Prasad, N. S.; Pliutau, D.

    2013-12-01

    We describe a methodology called Cross-Band Relative Absorption (CoBRA) we have implemented to significantly reduce interferences due to variations in atmospheric temperature and pressure in molecular mixing ration measurements [1-4]. The interference reduction is achieved through automatic compensation based on selecting spectral line pairs exhibiting similar evolution behavior under varying atmospheric conditions. The method is applicable to a wide range of molecules including CO2 and CH4 which can be matched with O2 or any other well-mixed atmospheric molecule. Such matching results in automatic simultaneous adjustments of the spectral line shapes at all times with a high precision under varying atmospheric conditions of temperature and pressure. We present the results of our selected CoBRA analysis based on line-by-line calculations and the Modern Era Retrospective Analysis for Research and Applications (MERRA) dataset including more recent evaluation of the error contributions due to water vapor interference effects. References: 1) N. S. Prasad, D. Pliutau, 'Cross-band relative absorption technique for the measurement of molecular mixing ratios.', Optics Express, Vol. 21, Issue 11, pp. 13279-13292 (2013) 2) D. Pliutau and N. S. Prasad, "Cross-band Relative Absorption Technique for Molecular Mixing Ratio Determination," in CLEO: 2013, OSA Technical Digest (online) (Optical Society of America, 2013), paper CW3L.4. 3) Denis Pliutau; Narasimha S. Prasad; 'Semi-empirical validation of the cross-band relative absorption technique for the measurement of molecular mixing ratios',.Proc. SPIE 8731, Laser Radar Technology and Applications XVIII, 87310L (May 20, 2013); doi:10.1117/12.2016661. 4) Denis Pliutau,; Narasimha S. Prasad; 'Comparative analysis of alternative spectral bands of CO2 and O2 for the sensing of CO2 mixing ratios' Proc. SPIE 8718, Advanced Environmental, Chemical, and Biological Sensing Technologies X, 87180L (May 31, 2013); doi:10.1117/12.2016337.

  10. Gain and Absorption of a Probe Light in an Open Tripod Atomic System

    Science.gov (United States)

    Hu, Zheng-Feng; Lin, Jin-Da; Deng, Jian-Liao; He, Hui-Juan; Wang, Yu-Zhu

    2012-05-01

    We theoretically investigate an open four-level atomic system interacting with control, probe and microwave fields. When there is no repumping light and a microwave field is applied, the probe light can be absorbed or amplified, which has different features than those of a system whose populations are pumped into only one ground state. In this system the microwave field and the population distributions of the ground states can be used as switches to control the propagation of the probe light.

  11. Determination of arsenic in geological materials by electrothermal atomic-absorption spectrometry after hydride generation

    Science.gov (United States)

    Sanzolone, R.F.; Chao, T.T.; Welsch, E.P.

    1979-01-01

    Rock and soil samples are decomposed with HClO4-HNO3; after further treatment, arsine is generated and absorbed in a dilute silver nitrate solution. Aliquots of this solution are injected into a carbon rod atomizer. Down to 1 ppm As in samples can be determined and there are no significant interferences, even from chromium in soils. Good results were obtained for geochemical reference samples. ?? 1979.

  12. Development of Two-Photon Pump Polarization Spectroscopy Probe Technique Tpp-Psp for Measurements of Atomic Hydrogen .

    Science.gov (United States)

    Satija, Aman; Lucht, Robert P.

    2015-06-01

    Atomic hydrogen (H) is a key radical in combustion and plasmas. Accurate knowledge of its concentration can be used to better understand transient phenomenon such as ignition and extinction in combustion environments. Laser induced polarization spectroscopy is a spatially resolved absorption technique which we have adapted for quantitative measurements of H atom. This adaptation is called two-photon pump, polarization spectroscopy probe technique (TPP-PSP) and it has been implemented using two different laser excitation schemes. The first scheme involves the two-photon excitation of 1S-2S transitions using a linearly polarized 243-nm beam. An anisotropy is created amongst Zeeman states in 2S-3P levels using a circularly polarized 656-nm pump beam. This anisotropy rotates the polarization of a weak, linearly polarized probe beam at 656 nm. As a result, the weak probe beam "leaks" past an analyzer in the detection channel and is measured using a PMT. This signal can be related to H atom density in the probe volume. The laser beams were created by optical parametric generation followed by multiple pulse dye amplification stages. This resulted in narrow linewidth beams which could be scanned in frequency domain and varied in energy. This allowed us to systematically investigate saturation and Stark effect in 2S-3P transitions with the goal of developing a quantitative H atom measurement technique. The second scheme involves the two-photon excitation of 1S-2S transitions using a linearly polarized 243-nm beam. An anisotropy is created amongst Zeeman states in 2S-4P transitions using a circularly polarized 486-nm pump beam. This anisotropy rotates the polarization of a weak, linearly polarized probe beam at 486 nm. As a result the weak probe beam "leaks" past an analyzer in the detection channel and is measured using a PMT. This signal can be related to H atom density in the probe volume. A dye laser was pumped by third harmonic of a Nd:YAG laser to create a laser beam

  13. 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.

  14. A high-bandwidth amplitude estimation technique for dynamic mode atomic force microscopy.

    Science.gov (United States)

    Karvinen, K S; Moheimani, S O R

    2014-02-01

    While often overlooked, one of the prerequisites for high-speed amplitude modulation atomic force microscopy is a high-bandwidth amplitude estimation technique. Conventional techniques, such as RMS to DC conversion and the lock-in amplifier, have proven useful, but offer limited measurement bandwidth and are not suitable for high-speed imaging. Several groups have developed techniques, but many of these are either difficult to implement or lack robustness. In this contribution, we briefly outline existing amplitude estimation methods and propose a new high-bandwidth estimation technique, inspired by techniques employed in microwave and RF circuit design, which utilizes phase cancellation to significantly improve the performance of the lock-in amplifier. We conclude with the design and implementation of a custom circuit to experimentally demonstrate the improvements and discuss its application in high-speed and multifrequency atomic force microscopy.

  15. Direct atomic absorption determination of cadmium and lead in strongly interfering matrices by double vaporization with a two-step electrothermal atomizer

    Science.gov (United States)

    Grinshtein, Ilia L.; Vilpan, Yuri A.; Saraev, Alexei V.; Vasilieva, Lubov A.

    2001-03-01

    Thermal pretreatment of a sample using double vaporization in a two-step atomizer with a purged vaporizer makes possible the direct analysis of samples with strongly interfering matrices including solids. A porous-graphite capsule or a filter inserted into the vaporizer is used for solid sample analysis. The technique was used for the direct determination of Cd and Pb in human urine, potatoes, wheat, bovine liver, milk powder, grass-cereal mixtures, caprolactam, bituminous-shale and polyvinyl chloride plastic without chemical modification or any other sample pretreatment.

  16. Direct measurement of interstellar extinction toward young stars using atomic hydrogen Lyα absorption

    Energy Technology Data Exchange (ETDEWEB)

    McJunkin, Matthew; France, Kevin; Brown, Alexander [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Schneider, P. C. [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany); Herczeg, Gregory J. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Hillenbrand, Lynne [California Institute of Technology, Department of Astrophysics, MC105-24, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Schindhelm, Eric [Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302 (United States); Edwards, Suzan, E-mail: matthew.mcjunkin@colorado.edu [Five College Astronomy Department, Smith College, Northampton, MA 01063 (United States)

    2014-01-10

    Interstellar reddening corrections are necessary to reconstruct the intrinsic spectral energy distributions (SEDs) of accreting protostellar systems. The stellar SED determines the heating and chemical processes that can occur in circumstellar disks. Measurement of neutral hydrogen absorption against broad Lyα emission profiles in young stars can be used to obtain the total H I column density (N(H I)) along the line of sight. We measure N(H I) with new and archival ultraviolet observations from the Hubble Space Telescope (HST) of 31 classical T Tauri and Herbig Ae/Be stars. The H I column densities range from log{sub 10}(N(H I)) ≈19.6-21.1, with corresponding visual extinctions of A{sub V} =0.02-0.72 mag, assuming an R{sub V} of 3.1. We find that the majority of the H I absorption along the line of sight likely comes from interstellar rather than circumstellar material. Extinctions derived from new HST blue-optical spectral analyses, previous IR and optical measurements, and new X-ray column densities on average overestimate the interstellar extinction toward young stars compared to the N(H I) values by ∼0.6 mag. We discuss possible explanations for this discrepancy in the context of a protoplanetary disk geometry.

  17. Determination of Zinc Ions in Environmental Samples by Dispersive Liquid- Liquid Micro Extraction and Atomic Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    F. Arabi

    2012-11-01

    Full Text Available In this work preconcentration of the Zn ions was investigated in water sample by Dispersive liquid- liquid micro extraction (DLLME using chloroform as an extraction solvent, methanol as a disperser solvent and 8-Hydroxyquinoline as a chelating agent. The determination of extracted ions was done by graphite furnace atomic absorption spectrometry. The influence of various analytical parameters including pH, extraction and disperser solvent type and volume and concentration of the chelating agent on the extraction efficiency of analyses was investigated. After extraction, the enrichment factor was 26 and the detection limit of the method was 0.0033 µg l-1 and the relative standard deviations (R.S.D for five determinations of 1 ng/ml Zn were 7.41%. 

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

    Science.gov (United States)

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

    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 molL(-1) HNO3 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 microgL(-1), respectively. The preconcentration factor was 200. The relative standard deviation of the method was gold in some environmental samples.

  19. Design and evaluation of a continuous flow, integrated nebulizer-hydride generator for flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Miguel Murillo

    2008-01-01

    Full Text Available An evaluation of the performance of a continuous flow hydride generator-nebulizer for flame atomic absorption spectrometry was carried out. Optimization of nebulizer gas flow rate, sample acid concentration, sample and tetrahydroborate uptake rates and reductant concentration, on the As and Se absorbance signals was carried out. A hydrogen-argon flame was used. An improvement of the analytical sensitivity relative to the conventional bead nebulizer used in flame AA was obtained (2 (As and 4.8 (Se µg L-1. Detection limits (3σb of 1 (As and 1.3 (Se µg L-1 were obtained. Accuracy of the method was checked by analyzing an oyster tissue reference material.

  20. Determination of arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc in geological materials by atomic-absorption spectrometry

    Science.gov (United States)

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

    1984-01-01

    Arsenic, antimony, bismuth, cadmium, copper, lead, molybdenum, silver and zinc are very useful elements in geochemical exploration. In the proposed method, geological samples are fused with potassium pyrosulphate and the fusate is dissolved in a solution of hydrochloric acid, ascorbic acid and potassium iodide. When this solution is shaken with a 10% V/V Aliquat 336 - isobutyl methyl ketone organic phase, the nine elements of interest are selectively partitioned in the organic phase. All nine elements can then be determined in the organic phase using flame atomic-absorption spectrometry. The method is rapid and allows the determination of Ag and Cd at levels down to 0.1 p.p.m., Cu, Mo, and Zn down to 0.5 p.p.m., Pb, Bi and Sb down to 1 p.p.m. and As down to 5 p.p.m. in geological materials.

  1. Performance of permanent iridium modifier in the presence of corrosive matrix in graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Piascik, M.; Bulska, E. [Univ. of Warsaw (Poland). Dept. of Chemistry

    2001-12-01

    The influence of up to 16% HNO{sub 3}, 28% HCl, and the mixture of both acids in aqua regia on the analytical performance of electrodeposited modifiers (Ir or Ir+Pd) was evaluated and discussed. Cadmium was used as an example of volatile elements often determined by graphite furnace atomic absorption spectrometry (GF AAS). In the presence of HCl, the maximum pyrolysis temperature that could be applied was found to be 600 C. In the presence of HNO{sub 3} and aqua regia, both modifiers stabilized cadmium up to 800 C. The long-term performance of electrodeposited Ir or Ir+Pd was not influenced by mineral acids; moreover the tube lifetime was significantly prolonged compared with a non-modified tube. (orig.)

  2. Application of radiochemical neutron activation and atomic absorption spectrometry methods for the study of nutrition-pollution interactions in children

    Energy Technology Data Exchange (ETDEWEB)

    Tran Bang Diep [Institute for Nuclear Science and Technique, VAEC, P.O. Box 5T-160, Hanoi (Viet Nam)]. E-mail: tranfbangdiepj@yahoo.com; Tran Dai Nghiep [Institute for Nuclear Science and Technique, VAEC, P.O. Box 5T-160, Hanoi (Viet Nam)]. E-mail: tdnghiep@vaec.gov.vn

    2005-07-01

    The application of radiochemical neutron activation analysis (RNAA) and atomic absorption spectrometry (AAS) is expected to aid in understanding and evaluating the effects of environmental pollution on the nutritional status of children already exposed to marginal malnutrition. Samples of placenta, of low-weight and control newborns groups, were collected for determination of nutritional elements and pollutants. The mean ratios of pollutants and nutrients such as Cd/Zn, Hg/Se and Pb/Ca were evaluated for both groups. All these ratios in the placenta of the low-weight newborns are higher than that of the healthy group. The degree of the nutrient-pollutant interaction is evaluated by quantity R, with mercury considered as the most active pollutant while calcium the most active nutrient among the involved elements in process of the interaction. (author)

  3. Application of a mixed solvent system in the determination of metals in lubricating oils using atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    E.O. Ojeka

    2006-06-01

    Full Text Available Analysis of lubricating oils and their additives for Ni, Zn, Mg and Ca was carried out by the proposed method using benzene-acetic acid/methyl isobutyl ketone (MIBK mixed solvent system. Flame atomic absorption spectrometry using air-acetylene flame was employed with the incorporation of concentrated hydrochloric acid into the solvent mixture. The large dilution of samples employed due to flexible working range of this procedure eliminates the need for matched standard hence the same standards are adequate for all types of lubricating oil samples and additives. No effect on the analysis arising from varying viscosities of the oil samples was observed. Results obtained for a wide range of lubricating oils and automatic transmission fluids revealed good agreement with those obtained by established ASTM chemical procedure.

  4. [Determination of lead in water samples by graphite furnace atomic absorption spectrometry after cloud point extraction with dithizone].

    Science.gov (United States)

    Xiao, Shan-Mei; Chen, Jian-Rong; Shen, Yu-Qin

    2006-05-01

    Cloud point extraction was used for the preconcentration of lead after the formation of a complex with dithizone in the presence of surfactant Triton X-114, and then the lead was determined by graphite furnace atomic absorption spectrometry. The conditions affecting the separation and detection process were optimized. Separation of the two phases was accomplished by centrifugation for 15 min at 4 000 rpm. Upon cooling in an ice-bath, the surfactant-rich phase became viscous. The aqueous phase could then be separated by inverting the tubes. Later, a solution of methanol containing 0.1 mol x L(-1) of HNO3 was added to the surfactant-rich phase up to 0.5 mL. The samples were determined by graphite furnace atomic absorption spectrometry with NH4H2PO4 and Mg(NO3)2 as a chemical modifier. At pH 8.0, the preconcentration of only 10 mL sample in the presence of 0.05% Triton X-114 and 20 micromol x L(-1) dithizone permitted the detection of 0.089 microg x L(-1) lead. The enhancement factors were 19.1 times for lead. The calibration graph using the preconcentration system for lead was linear with a correlation coefficient of 0.998 from levels near the detection limits up to at least 30 microg x L(-1). The regression equation was A = 0.026 1c (microg x L(-1)) + 0.010 6. The proposed method has been applied to the determination of lead in water samples.

  5. Improved limit of detection and quantitation development and validation procedure for quantification of zinc in Insulin by atomic absorption spectrometry.

    Science.gov (United States)

    Qadir, Muhammad Abdul; Ahmed, Mahmood; Haq, Iftikharul; Ahmed, Saghir

    2015-05-01

    A simple and expeditious analytical method for determination of zinc in human insulin isophane suspension by flame atomic absorption spectrophotometer (FAAS) was validated. The method was carried out on atomic absorption spectrometer with 0.4 nm bandwidth, 1.0 filter factor on deuterium (D2) background correction. The integration time was set at 3.0 second with 5.0 mA lamp current. The parameters of method validation showed adequate linearity, efficiency and relative standard deviation values were between 0.64%-1.69% (n=7), 1.31%-1.58% (n=10) for repeatability and intermediate precision respectively. The limit of detection 0.0032 μg/mL, 0.0173 μg/mL, 0.0231 μg/mL and limit of quantitation 0.0107μg/mL, 0.0578 μg/mL, 0.0694 μg/mL based on signal to noise (SN), calibration curve method (CCM) and fortification of blank (FB) were obtained respectively. The percentages of recovery for low, medium and high spiked concentration levels of zinc in human insulin were 99.38 ± 0.04 to 100.3 ± 0.03, 98.45 ± 0.38 to 100.3 ± 0.07 and 99.42 ± 0.03 to 99.42 ± 0.08 respectively. With the use of this method, five samples from each vial of human insulin isophane suspension were analyzed and the zinc content was determined. The zinc content were 22.1 ± 0.025 μg/mL and 24.3 ± 0.028 μg/mL which compliance the British Pharmacopoeia standard.

  6. A review of demodulation techniques for amplitude-modulation atomic force microscopy.

    Science.gov (United States)

    Ruppert, Michael G; Harcombe, David M; Ragazzon, Michael R P; Moheimani, S O Reza; Fleming, Andrew J

    2017-01-01

    In this review paper, traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system. As a crucial bandwidth-limiting component in the z-axis feedback loop of an atomic force microscope, the purpose of the demodulator is to obtain estimates of amplitude and phase of the cantilever deflection signal in the presence of sensor noise or additional distinct frequency components. Specifically for modern multifrequency techniques, where higher harmonic and/or higher eigenmode contributions are present in the oscillation signal, the fidelity of the estimates obtained from some demodulation techniques is not guaranteed. To enable a rigorous comparison, the performance metrics tracking bandwidth, implementation complexity and sensitivity to other frequency components are experimentally evaluated for each method. Finally, the significance of an adequate demodulator bandwidth is highlighted during high-speed tapping-mode atomic force microscopy experiments in constant-height mode.

  7. A review of demodulation techniques for amplitude-modulation atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Michael G. Ruppert

    2017-07-01

    Full Text Available In this review paper, traditional and novel demodulation methods applicable to amplitude-modulation atomic force microscopy are implemented on a widely used digital processing system. As a crucial bandwidth-limiting component in the z-axis feedback loop of an atomic force microscope, the purpose of the demodulator is to obtain estimates of amplitude and phase of the cantilever deflection signal in the presence of sensor noise or additional distinct frequency components. Specifically for modern multifrequency techniques, where higher harmonic and/or higher eigenmode contributions are present in the oscillation signal, the fidelity of the estimates obtained from some demodulation techniques is not guaranteed. To enable a rigorous comparison, the performance metrics tracking bandwidth, implementation complexity and sensitivity to other frequency components are experimentally evaluated for each method. Finally, the significance of an adequate demodulator bandwidth is highlighted during high-speed tapping-mode atomic force microscopy experiments in constant-height mode.

  8. Detection of copper in water using on-line plasma-excited atomic absorption spectroscopy (AAS).

    Science.gov (United States)

    Porento, Mika; Sutinen, Veijo; Julku, Timo; Oikari, Risto

    2011-06-01

    A measurement method and apparatus was developed to measure continuously toxic metal compounds in industrial water samples. The method was demonstrated by using copper as a sample metal. Water was injected into the sample line and subsequently into a nitrogen plasma jet, in which the samples comprising the metal compound dissolved in water were decomposed. The transmitted monochromatic light was detected and the absorbance caused by copper atoms was measured. The absorbance and metal concentration were used to calculate sensitivity and detection limits for the studied metal. The sensitivity, limit of detection, and quantification for copper were 0.45 ± 0.02, 0.25 ± 0.01, and 0.85 ± 0.04 ppm, respectively.

  9. Particular problems encountered in trace metal analysis of plant material by atomic absorption spectrometry

    Science.gov (United States)

    Hoenig, M.; de Borger, R.

    Various mineralization methods for plant material analysis by AAS are presented and their advantages and limits are discussed. Wet digestion by H 2SO 4HNO 3H 2O 2 mixture appears as a very rapid method which gives good recovery of trace elements and is thus suitable for routine analysis. Determination of relatively high concentrations of Cu, Zn, Fe, Mn, Ni, Cr, Co, Cd, Pb, As, Sb and Tl is carried out by flame AAS with a good analytical speed and without noticeable interferences. Pb, Cd, As, Sb and Tl appear generally in very low concentrations in plants so that electrothermal atomization is necessary. Various interferences are observed in this case. They are discussed and methods are presented for their correction.

  10. An X-ray absorption spectroscopy investigation of the local atomic structure in Cu-Ni-Si alloy after severe plastic deformation and ageing

    Science.gov (United States)

    Azzeddine, H.; Harfouche, M.; Hennet, L.; Thiaudiere, D.; Kawasaki, M.; Bradai, D.; Langdon, T. G.

    2015-08-01

    The local atomic structure of Cu-Ni-Si alloy after severe plastic deformation (SPD) processing and the decomposition of supersaturated solid solution upon annealing were investigated by means of X-ray absorption spectroscopy. The coordination number and interatomic distances were obtained by analyzing experimental extend X-ray absorption fine structure data collected at the Ni K-edge. Results indicate that the environment of Ni atoms in Cu-Ni-Si alloy is strongly influenced by the deformation process. Moreover, ageing at 973 K affects strongly the atomic structure around the Ni atoms in Cu-Ni-Si deformed by equal channel angular pressing and high pressure torsion. This influence is discussed in terms of changes and decomposition features of the Cu-Ni-Si solid solution.

  11. Unraveling the solid-liquid-vapor phase transition dynamics at the atomic level with ultrafast x-ray absorption near-edge spectroscopy.

    Science.gov (United States)

    Dorchies, F; Lévy, A; Goyon, C; Combis, P; Descamps, D; Fourment, C; Harmand, M; Hulin, S; Leguay, P M; Petit, S; Peyrusse, O; Santos, J J

    2011-12-09

    X-ray absorption near-edge spectroscopy (XANES) is a powerful probe of electronic and atomic structures in various media, ranging from molecules to condensed matter. We show how ultrafast time resolution opens new possibilities to investigate highly nonequilibrium states of matter including phase transitions. Based on a tabletop laser-plasma ultrafast x-ray source, we have performed a time-resolved (∼3  ps) XANES experiment that reveals the evolution of an aluminum foil at the atomic level, when undergoing ultrafast laser heating and ablation. X-ray absorption spectra highlight an ultrafast transition from the crystalline solid to the disordered liquid followed by a progressive transition of the delocalized valence electronic structure (metal) down to localized atomic orbitals (nonmetal-vapor), as the average distance between atoms increases.

  12. Determination of arsenic in petroleum refinery streams by electrothermal atomic absorption spectrometry after multivariate optimization based on Doehlert design

    Science.gov (United States)

    Cassella, Ricardo J.; de Sant'Ana, Otoniel D.; Santelli, Ricardo E.

    2002-12-01

    This paper reports the development of a methodology for the determination of arsenic in petroleum refinery aqueous streams containing large amounts of unknown volatile organic compounds, employing electrothermal atomic absorption spectrometry with polarized Zeeman-effect background correction. In order to make the procedure applicable, the influence of chemical modification and the drying step was examined. Also, pyrolysis and atomization temperatures and the amount of nitric acid added to the sample were optimized using a multivariate approach based on Doehlert matrix. Obtained results indicate that, in this kind of sample, arsenic must be determined by standard addition procedure with a careful control of the drying step temperature and ramp pattern. In order to evaluate the accuracy of the procedure, a test was performed in six spiked samples of petroleum refinery aqueous streams and the relative errors verified in the analysis of such samples (added As between 12.5 and 190 μg l -1) ranged from -7.2 to +16.7%. The detection limit and the relative standard deviation were also calculated and the values are 68 pg and 7.5% (at 12.5 μg l -1 level), respectively.

  13. Dosage du mercure dans le gaz naturel par absorption atomique sans flammes Mercury Titration in Natural Gas by Flameless Atomic Absorption

    Directory of Open Access Journals (Sweden)

    La Villa F.

    2006-11-01

    Full Text Available Cet article présente la méthode mise au point par l'Institut Français du Pétrole pour déterminer par absorption atomique sans flamme, les traces de mercure métallique contenu dans un gaz naturel. La méthode d'analyse nécessite une extraction du mercure soit sous forme d'ion mercurique en faisant passer le gaz dans une solution oxydante, soit sous forme d'amalgame avec de l'or ou de l'argent. Le premier mode opératoire s'applique aux échantillons dont la concentration en mercure est supérieure à I ttg/Nm3, le second pour des concentrations inférieures à 5 pg/Nm3. Les seuils de détection sont respectivement 10 ng (en solution et 0,3 ng (en amalgame. La répétabilité pour 100 ng de mercure (en amalgame est de ± 7% pour une probabilité de.95 %. En conclusion, dans un échantillon de gaz naturel, compte tenu du volume des prélèvements effectués, il est possible de détecter des concentrations de l'ordre du nanogramme de mercure par mètre cube de gaz. This article describes the method developed by IFP using flameless atomic absorption to determine metallic mercury traces in a natural gas. The analyst method requires a mercury extraction either in the form of mercuric ions by making the gas pass through an oxidizing solution or in the form of an amalgam with gold or silver. The former operating method applies ta samples having a mercury concentration greater than I !ag/Nm3, and the latter for concentrations smaller than 5 (-Lg/Nm3. Detection thresholds are respectively 10 ng (in solution and 0.3 ng (in amalgam. The repeatability for 100 ng of mercury (in amalgam is ± 7 % with a probability of 95%. To conclude, in a sample of natural gas, considering the volume of the samples taken, it is possible ta detect concentrations in the vicinity of one nanogrom of mercury per cubic meter of gas.

  14. Effect of two kinds of iron drops on the discoloration, atomic absorption and structural changes of primary teeth enamel

    Directory of Open Access Journals (Sweden)

    Mehran M.

    2009-03-01

    Full Text Available "nBackground and Aim: Black staining after taking iron drops on the primary teeth is always concern of parents. There is not an exact explanation for the mechanism of iron black staining. The purpose of this study was to compare tooth discolorations, atomic absorption and structural changes of primary teeth enamel caused by two kinds of iron drops[ Kharazmi(Iran and Fer-in-sol(USA]. "nMaterials and Methods: In this ex-vivo study, 93 sound primary teeth in normal color range were divided into five groups. Two groups of samples were immersed into the Artificial Caries Challenge(ACC for two weeks before getting exposured to iron drops: Group 1 Control(NS: sound enamel teeth which were kept in Normal Saline environment(NS(13teeth. Group 2 (NS-KH: NS, kharazmi iron drop (20 teeth. Group 3 (ACC-KH: ACC, Kharazmi iron drop (20teeth. Group 4 (NS-F-in-S: NS, Fer-in-Sol iron drop (20teeth. Group 5 (ACC-F-in-S: ACC, Fer-in-Sol iron drop. Visual tooth discolorations were determined by a specialist in operative dentistry who was not aware of experimental groups. The iron concentration was measured by ICP system (Vista-pro, Australia and the structural changes were studied by SEM (Philips, Netherland. The data of discoloration were studied with Kruskal-Wallis test and multiple comparison using Bonferroni type test, and with the data of atomic absorption were studied with oneway ANOVA test and Tukey HSD test. "nResults: The discoloration in the teeth immersed into the ACC (ACC-KH, ACC-F-in-S was more severe than the sound enamel surface (NS-KH, NS-F-IN-S (p<0.001 and Kharazmi iron drop caused more discoloration in the teeth immersed into the ACC (p=0.018. The teeth immersed into the ACC, absorbed more iron than the sound enamel surface (p<0.001 and also the teeth immersed into the ACC absorbed more Kharazmi iron drop (p<0.001. In the Scanning Electron Microscopy study, at low magnification in the sound teeth the perikymata was arranged regular. At low

  15. The determination of silver in silicate rocks by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Aruscavage, P. J.; Campbell, E.Y.

    1979-01-01

    Silver is extracted from a 20% tartaric acid solution by using butyl acetate and diphenylthiourea, and the organic layer is analyzed directly by the graphite-furnace technique. The precisions is ca. 8% as estimated from multiple analysis of 13 standard rocks; there are no systematic errors. The detection limit is 2.4 ppb for 250-mg samples. ?? 1979.

  16. Arsenic speciation in environmental samples by hydride generation and electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Anawar, Hossain Md

    2012-01-15

    For the past few years many studies have been performed to determine arsenic (As) speciation in drinking water, food chain and other environmental samples due to its well-recognized carcinogenic and toxic effects relating to its chemical forms and oxidation states. This review provides an overview of analytical methods, preconcentration and separation techniques, developed up to now, using HGAAS and ETAAS for the determination of inorganic As and organoarsenic species in environmental samples. Specific advantages, disadvantages, selectivity, sensitivity, efficiency, rapidity, detection limit (DL), and some aspects of recent improvements and modifications for different analytical and separation techniques, that can define their application for a particular sample analysis, are highlighted. HG-AAS has high sensitivity, selectivity and low DL using suitable separation techniques; and it is a more suitable, affordable and much less expensive technique than other detectors. The concentrations of HCl and NaBH(4) have a critical effect on the HG response of As species. Use of l-cysteine as pre-reductant is advantageous over KI to obtain the same signal response for different As species under the same, optimum and mild acid concentration, and to reduce the interference of transition metals on the arsine generation. Use of different pretreatment, digestion, separation techniques and surfactants can determine As species with DL from ngL(-1) to μgL(-1). Out of all the chromatographic techniques coupled with HGAAS/ETAAS, ion-pair reversed-phase chromatography (IP-RP) is the most popular due to its higher separation efficiency, resolution selectivity, simplicity, and ability to separate up to seven As species for both non-ionic and ionic compounds in a signal run using the same column and short time. However, a combination of anion- and cation-exchange chromatography seems the most promising for complete resolution up to eight As species. The ETAAS method using different

  17. Direct determination of Pb in raw milk by graphite furnace atomic absorption spectrometry (GF AAS) with electrothermal atomization sampling from slurries.

    Science.gov (United States)

    de Oliveira, Tatiane Milão; Augusto Peres, Jayme; Lurdes Felsner, Maria; Cristiane Justi, Karin

    2017-08-15

    Milk is an important food in the human diet due to its physico-chemical composition; therefore, it is necessary to monitor contamination by toxic metals such as Pb. Milk sample slurries were prepared using Triton X-100 and nitric acid for direct analysis of Pb using graphite furnace atomic absorption spectrometry - GF AAS. After dilution of the slurries, 10.00µl were directly introduced into the pyrolytic graphite tube without use of a chemical modifier, which acts as an advantage considering this type of matrix. The limits of detection and quantification were 0.64 and 2.14µgl(-1), respectively. The figures of merit studied showed that the proposed methodology without pretreatment of the raw milk sample and using external standard calibration is suitable. The methodology was applied in milk samples from the Guarapuava region, in Paraná State (Brazil) and Pb concentrations ranged from 2.12 to 37.36µgl(-1). Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Separation and preconcentration by flow injection coupled to tungsten coil electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Silva, Márcia M.; Krug, Francisco J.; Oliveira, Pedro V.; Nóbrega, Joaquim A.; Reis, Boaventura F.; Penteado, Daniel A. G.

    1996-12-01

    A flow injection system coupled to a tungsten coil electrothermal atomizer has been developed for on-line separation and preconcentration, using lead as a model element. The system utilizes three-way solenoid valves for sampling, buffering, washing and reconditioning solution management, and the resin column is inserted in the tip of the autosampler arm of a Varian GTA-96. The solenoid valves and tungsten coil power supply were controlled by a computer program written in Visual Basic, interfaced with the built-in Varian software. The system performance was tested by loading the resin column with the sample flowing at 3 ml min -1 for 60 s. Elution was performed automatically by sampling 20 μl of the eluent from a sample cup of the autosampler, and this aliquot was delivered into a 150 W tungsten coil. With Chelex-100 resin, the separation of concomitants was tested with lead in the presence of as much as 1000 mg l -1 of Ca, Mg, Na or K. The model system presented an enrichment factor of 64 at a sampling rate of 30 samples per hour.

  19. Determination of vanadium in human hair slurries by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Fernandes, Kelly G; Nogueira, Ana Rita A; Neto, José A Gomes; Nóbrega, Joaquim A

    2007-02-28

    This work describes an analytical procedure for vanadium determination in human hair slurries by electrothermal AAS using longitudinal heating (LHGA) and transversal heating (THGA) graphite furnace atomizers. The samples were powdered using cryogenic grinding and the hair slurries containing 0.2% (m/v) were prepared in three different media for determination of vanadium: 0.14molL(-1) HNO(3), 0.1% (v/v) Triton X-100 and 0.1% (v/v) water soluble tertiary amines (CFA-C, pH 8). The limits of detection (LOD), limits of quantification (LOQ), and characteristic masses obtained were 0.28, 0.95mugL(-1) and 35pg (LHGA) and 0.34, 1.13mugL(-1) and 78pg (THGA), respectively. The accuracy of the analytical results obtained by the proposed procedure in both equipments was confirmed by a paired t-test at the 95% confidence level and compared with a conventional procedure based on acid digestion.

  20. Determination of Cd, Co, Cu, Mn, Ni, Pb, and Zn by Inductively Coupled Plasma Mass Spectroscopy or Flame Atomic Absorption Spectrometry after On-line Preconcentration and Solvent Extraction by Flow Injection System

    Science.gov (United States)

    Bortoli; Gerotto; Marchiori; Mariconti; Palonta; Troncon

    1996-11-01

    The concentrations of Cd, Co, Cu, Mn, Ni, Pb, and Zn in natural and sea waters are too low to be directly determined with by flame atomic absorption spectrometry (FAAS) or graphite furnace atomic absorption spectrometry (GFAAS). Specific sample preparations are requested that make possible the determination of these analytes by preconcentration or extraction. These techniques are affected by severe problems of sample contamination. In this work Cd, Co, Cu, Mn, Ni, Pb, and Zn were determined by inductively coupled plasma mass spectroscopy (ICP-MS) or by atomic absorption spectrometry, in fresh and seawater samples, after on-line preconcentration and following solvent elution with a flow injection system. Bonded silica with octadecyl functional group C18, packed in a microcolumn of 100-μl capacity, was used to collect diethyldithiocarbamate complexes of the heavy metals in aqueous solutions. The metals are complexed with a chelating agent, adsorbed on the C18 column, and eluted with methanol directly in the flow injection system. The methanolic stream can be addressed to FAAS for direct determination of Cu, Ni, and Zn, or collected in a vial for successive analysis by GFAAS. The eluted samples can be also dried in a vacuum container and restored to a little volume with concentrated HNO3 and Milli-Q water for analysis by ICP-MS or GFAAS.

  1. Direct determination of chromium in infant formulas employing high-resolution continuum source electrothermal atomic absorption spectrometry and solid sample analysis.

    Science.gov (United States)

    Silva, Arlene S; Brandao, Geovani C; Matos, Geraldo D; Ferreira, Sergio L C

    2015-11-01

    The present work proposed an analytical method for the direct determination of chromium in infant formulas employing the high-resolution continuum source electrothermal atomic absorption spectrometry combined with the solid sample analysis (SS-HR-CS ET AAS). Sample masses up to 2.0mg were directly weighted on a solid sampling platform and introduced into the graphite tube. In order to minimize the formation of carbonaceous residues and to improve the contact of the modifier solution with the solid sample, a volume of 10 µL of a solution containing 6% (v/v) H2O2, 20% (v/v) ethanol and 1% (v/v) HNO3 was added. The pyrolysis and atomization temperatures established were 1600 and 2400 °C, respectively, using magnesium as chemical modifier. The calibration technique was evaluated by comparing the slopes of calibration curves established using aqueous and solid standards. This test revealed that chromium can be determined employing the external calibration technique using aqueous standards. Under these conditions, the method developed allows the direct determination of chromium with limit of quantification of 11.5 ng g(-1), precision expressed as relative standard deviation (RSD) in the range of 4.0-17.9% (n=3) and a characteristic mass of 1.2 pg of chromium. The accuracy was confirmed by analysis of a certified reference material of tomato leaves furnished by National Institute of Standards and Technology. The method proposed was applied for the determination of chromium in five different infant formula samples. The chromium content found varied in the range of 33.9-58.1 ng g(-1) (n=3). These samples were also analyzed employing ICP-MS. A statistical test demonstrated that there is no significant difference between the results found by two methods. The chromium concentrations achieved are lower than the maximum limit permissible for chromium in foods by Brazilian Legislation. Copyright © 2015. Published by Elsevier B.V.

  2. Solid sampling graphite furnace atomic absorption spectrometry for the direct analysis of microextraction solvent bars used for metal ultra-trace pre-concentration

    Science.gov (United States)

    González-Álvarez, Rafael Jesús; Pinto, Juan J.; Bellido-Milla, Dolores; Moreno, Carlos

    2017-09-01

    The potential applicability of the continuum source solid sampling graphite furnace atomic absorption spectroscopy (CS SS-GF AAS) technique has been studied to carry out the direct analysis of microextraction solvent bars used for metal ultra-trace pre-concentration in natural waters. An optimisation of the temperature program was developed for this purpose. Preliminary chamber furnace studies were performed in order to understand the behaviour of the bars with the increasing temperature. Solvent bars were filled with an acceptor solution, impregnated with an organic extractant and placed into the chamber furnace to carry out several temperature programs. Results led to perform a correct optimisation of the drying and pyrolysis steps of the furnace temperature program, which was tested with silver once completed. Blank solvent bars as well as standards containing silver were measured, obtaining a calibration curve with a correlation coefficient of 0.991. The results exhibited good repeatability and reproducibility, with relative standard deviations below 10% in both cases, indicating a promising applicability of the CS SS-GF AAS technique to directly determine metallic species in microextraction solvent bars.

  3. Determination of nickel in food samples by flame atomic absorption spectroscopy after preconcentration and microextraction based ionic liquids using full factorial and central composite design.

    Science.gov (United States)

    Zarei, Zohre; Shemirani, Farzaneh

    2012-12-01

    In this research, a microextraction technique based on ionic liquids (ILs) termed in situ solvent formation microextraction (ISFME) was used for determination of nickel in solutions. 1-(2-pyridylazo)-2-naphtol (PAN) was chosen as a complexing agent. After preconcentration, the settled IL-phase was dissolved in 50 μL of ethanol and aspirated into the flame atomic absorption spectrometer (FAAS) using a home-made microsample introduction system. Injection of 50 μL volumes of analyte into an air-acetylene flame provided very sensitive spike-like and reproducible signals. ISFME is based on phase separation phenomenon of ionic liquids in aqueous solutions. This method is simple and rapid for extraction and preconcentration of metal ions from food samples and can be applied for the sample solutions containing very high concentrations of salt. Furthermore, this technique is much safer in comparison with the organic solvent extraction because of using ionic liquid. The effective parameters such as amount of IL, salt effect, concentration of the chelating agent and ion pairing agent were inspected by a full factorial design to identify important parameters and their interactions. Next, a central composite design was applied to obtain optimum point of the important parameters. Under the optimum conditions, the calibration graph was linear over the range of 2 to 80 ng/mL. The limit of detection and relative standard deviation (n= 6) were 0.6 ng/mL and 2%, respectively. © 2012 Institute of Food Technologists®

  4. Comparison of four analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs.

    Science.gov (United States)

    Boutakhrit, K; Crisci, M; Bolle, F; Van Loco, J

    2011-02-01

    Different techniques for the determination of total tin in beverages and canned foods by atomic spectrometry were compared. The performance characteristics of inductively coupled plasma-mass spectrometry (ICP-MS), hydride generation-inductively coupled plasma-atomic emission spectrometry (HG-ICP-AES), electrothermal atomisation-atomic absorption spectrometry (ETA-AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES) were determined in terms of linearity, precision, recovery, limit of detection, decision limit (CCα) and detection capability (CCβ) (Decision 2002/657/EC). Calibration ranges were covered from ng l⁻¹ to mg l⁻¹ level. Limits of detection that ranged from 0.01, 0.05, 2.0 to 200 µg l⁻¹ were reached for ICP-MS; HG-ICP-AES; ETA-AAS and ICP-AES, respectively. Precision, calculated according to ISO 5725-2 for repeatability and within-laboratory reproducibility and expressed as relative standard deviation (RSD), ranged from 1.6% to 4.9%; and recovery, based on Decision 2002/657/EC, was found to be between 95% and 110%. Procedures for the mineralisation or extraction of total tin were compared. Wet digestion, sequentially, with nitric acid and hydrogen peroxide provided the best results. The influence of possible interferences present in canned food and beverage was studied, but no interference in the determination of tin was observed. Since maximum levels for tin established by European Union legislation vary from 50 mg kg⁻¹ in canned baby foods and infant foods up to 200 mg kg⁻¹ in canned food, ICP-AES was chosen as the preferred technique for routine analysis thanks to its good precision, reliability and ease of use. The accuracy of this routine method was confirmed by participation in six proficiency test schemes with z-scores ranging from -1.9 to 0.6. Several canned foodstuffs and beverage samples from a local market were analysed with this technique.

  5. Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

    Science.gov (United States)

    Kruger, Pamela C.; Parsons, Patrick J.

    2007-03-01

    Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass ( m0), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 ± 0.6 pg, compared to 16.1 ± 0.7 pg for the Z5100, and 23.3 ± 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection limits (3

  6. Determination of serum aluminum by electrothermal atomic absorption spectrometry: A comparison between Zeeman and continuum background correction systems

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, Pamela C. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Parsons, Patrick J. [Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, P.O. Box 509, Albany, NY 12201-0509 (United States); Lead Poisoning/Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States)], E-mail: patrick.parsons@wadsworth.org

    2007-03-15

    Excessive exposure to aluminum (Al) can produce serious health consequences in people with impaired renal function, especially those undergoing hemodialysis. Al can accumulate in the brain and in bone, causing dialysis-related encephalopathy and renal osteodystrophy. Thus, dialysis patients are routinely monitored for Al overload, through measurement of their serum Al. Electrothermal atomic absorption spectrometry (ETAAS) is widely used for serum Al determination. Here, we assess the analytical performances of three ETAAS instruments, equipped with different background correction systems and heating arrangements, for the determination of serum Al. Specifically, we compare (1) a Perkin Elmer (PE) Model 3110 AAS, equipped with a longitudinally (end) heated graphite atomizer (HGA) and continuum-source (deuterium) background correction, with (2) a PE Model 4100ZL AAS equipped with a transversely heated graphite atomizer (THGA) and longitudinal Zeeman background correction, and (3) a PE Model Z5100 AAS equipped with a HGA and transverse Zeeman background correction. We were able to transfer the method for serum Al previously established for the Z5100 and 4100ZL instruments to the 3110, with only minor modifications. As with the Zeeman instruments, matrix-matched calibration was not required for the 3110 and, thus, aqueous calibration standards were used. However, the 309.3-nm line was chosen for analysis on the 3110 due to failure of the continuum background correction system at the 396.2-nm line. A small, seemingly insignificant overcorrection error was observed in the background channel on the 3110 instrument at the 309.3-nm line. On the 4100ZL, signal oscillation was observed in the atomization profile. The sensitivity, or characteristic mass (m{sub 0}), for Al at the 309.3-nm line on the 3110 AAS was found to be 12.1 {+-} 0.6 pg, compared to 16.1 {+-} 0.7 pg for the Z5100, and 23.3 {+-} 1.3 pg for the 4100ZL at the 396.2-nm line. However, the instrumental detection

  7. An investigation of polarized atomic photofragments using the ion imaging technique

    Energy Technology Data Exchange (ETDEWEB)

    Bracker, A.S.

    1997-12-01

    This thesis describes measurement and analysis of the recoil angle dependence of atomic photofragment polarization (atomic v-J correlation). This property provides information on the electronic rearrangement which occurs during molecular photodissociation. Chapter 1 introduces concepts of photofragment vector correlations and reviews experimental and theoretical progress in this area. Chapter 2 described the photofragment ion imaging technique, which the author has used to study the atomic v-J correlation in chlorine and ozone dissociation. Chapter 3 outlines a method for isolating and describing the contribution to the image signal which is due exclusively to angular momentum alignment. Ion imaging results are presented and discussed in Chapter 4. Chapter 5 discusses a different set of experiments on the three-fragment dissociation of azomethane. 122 refs.

  8. Investigation of spectral interferences in the determination of lead in fertilizers and limestone samples using high-resolution continuum source graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Aline R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Becker, Emilene M.; François, Luciane L.; Jesus, Alexandre de [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Vale, Maria Goreti R. [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Welz, Bernhard [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil); Departamento de Química, Universidade Federal de Santa Catarina, 88040-900 Florianópolis, SC (Brazil); Dessuy, Morgana B., E-mail: mbdessuy@ufrgs.br [Instituto de Química, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 9500, 91501-970 Porto Alegre, RS (Brazil); Andrade, Jailson B. de [Instituto Nacional de Ciência e Tecnologia do CNPq — INCT de Energia e Ambiente, Universidade Federal da Bahia, Salvador, BA (Brazil)

    2014-11-01

    In the present work, spectral interferences on the determination of lead in fertilizer and limestone samples were investigated using high-resolution continuum source graphite furnace atomic absorption spectrometry at the main analytical lines: 217.001 and 283.306 nm. For these investigations, samples were introduced into the furnace as slurry together with a mixture of Pd and Mg as chemical modifier. Spectral interferences were observed for some samples at both analytical lines. In order to verify whether a wet digestion procedure would avoid these interferences, a reference method for wet digestion of fertilizers was employed as an alternative sample preparation procedure. However, the same interferences were also observed in the digested samples. In order to identify and eliminate the fine-structured background using a least-squares background correction, reference spectra were generated using the combination of different species. The use of the latter technique allowed the elimination of spectral interferences for most of the investigated samples, making possible the determination of lead in fertilizer and limestone samples free of interferences. The best results were found using a reference spectrum of NH{sub 4}H{sub 2}PO{sub 4} at 217.001 nm, and a mixture of H{sub 2}SO{sub 4} + Ca and HNO{sub 3} + Ca at the 283.306 nm line. The accuracy of the method was evaluated using a certified reference material “Trace Elements in Multi-Nutrient Fertilizer”. Similar results were obtained using line source graphite furnace atomic absorption spectrometry with Zeeman-effect background correction, indicating that the latter technique was also capable to correct the spectral interferences, at least in part. - Highlights: • Spectral interferences on the determination of lead in fertilizers and limestone. • The analytical lines at 217.001 nm and 283.306 nm using HR-CS GF AAS. • Various combinations of compounds were used to create reference spectra. • LSBC

  9. Absolute atomic oxygen and nitrogen densities in radio-frequency driven atmospheric pressure cold plasmas: Synchrotron vacuum ultra-violet high-resolution Fourier-transform absorption measurements

    Energy Technology Data Exchange (ETDEWEB)

    Niemi, K.; O' Connell, D.; Gans, T. [York Plasma Institute, Department of Physics, University of York, York YO10 5DD (United Kingdom); Oliveira, N. de; Joyeux, D.; Nahon, L. [Synchrotron Soleil, l' Orme des Merisiers, St. Aubin BP 48, 91192 Gif sur Yvette Cedex (France); Booth, J. P. [Laboratoire de Physique des Plasmas-CNRS, Ecole Polytechnique, 91128 Palaiseau (France)

    2013-07-15

    Reactive atomic species play a key role in emerging cold atmospheric pressure plasma applications, in particular, in plasma medicine. Absolute densities of atomic oxygen and atomic nitrogen were measured in a radio-frequency driven non-equilibrium plasma operated at atmospheric pressure using vacuum ultra-violet (VUV) absorption spectroscopy. The experiment was conducted on the DESIRS synchrotron beamline using a unique VUV Fourier-transform spectrometer. Measurements were carried out in plasmas operated in helium with air-like N{sub 2}/O{sub 2} (4:1) admixtures. A maximum in the O-atom concentration of (9.1 {+-} 0.7) Multiplication-Sign 10{sup 20} m{sup -3} was found at admixtures of 0.35 vol. %, while the N-atom concentration exhibits a maximum of (5.7 {+-} 0.4) Multiplication-Sign 10{sup 19} m{sup -3} at 0.1 vol. %.

  10. Direct determination of particulate elements in edible oils and fats using an ultrasonic slurry sampler with graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    van Dalen, Gerard; de Galan, Leo

    1994-12-01

    Through the use of an ultrasonic slurry mixer, graphite furnace atomic absorption spectrometry (GFAAS) can be applied for the fully automated determination of particulate iron and nickel in edible oils and fats. The unsupervised ultrasonic slurry autosampler yields the same accuracy and somewhat better precision than the much more laborious manual GFAAS method.

  11. Analysis of an Air Conditioning Coolant Solution for Metal Contamination Using Atomic Absorption Spectroscopy: An Undergraduate Instrumental Analysis Exercise Simulating an Industrial Assignment

    Science.gov (United States)

    Baird, Michael J.

    2004-01-01

    A real-life analytical assignment is presented to students, who had to examine an air conditioning coolant solution for metal contamination using an atomic absorption spectroscopy (AAS). This hands-on access to a real problem exposed the undergraduate students to the mechanism of AAS, and promoted participation in a simulated industrial activity.

  12. 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,…

  13. An expression for the atomic fluorescence and thermal-emission intensity under conditions of near saturation and arbitrary self-absorption

    NARCIS (Netherlands)

    Omenetto, N.; Winefordner, J.D.; Alkemade, C.T.J.

    An expression for the effect of self-absorption on the fluorescence and thermal emission intensities is derived by taking into account stimulated emission. A simple, idealized case is considered, consisting of a two level atomic system, in a flame, homogeneous with respect to temperature and

  14. The Use of a Microprocessor-Controlled, Video Output Atomic Absorption Spectrometer as an Educational Tool in a Two-Year Technical Curriculum.

    Science.gov (United States)

    Kerfoot, Henry B.

    Based on instructional experiences at Charles County Community College, Maryland, this report examines the pedagogical advantage of teaching atomic absorption (AA) spectroscopy with an AA spectrophotometer that is equipped with a microprocessor and video output mechanism. The report first discusses the growing importance of AA spectroscopy in…

  15. Speciation of arsenic(III)/arsenic(V) and selenium(IV)/ selenium(VI) using coupled ion chromatography - hydride generation atomic absorption spectrometry

    Science.gov (United States)

    Simple analytical methods have been developed to speciate inorganic arsenic and selenium in the ppb range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determinations of the redox states arsenite A...

  16. Selective Flow Injection Analysis of Ultra-trace Amounts of Cr(VI), Preconcentration of It by Solvent Extraction, and Determination by Electrothermal Atomic Absorption Spectrometry (ETAAS)

    DEFF Research Database (Denmark)

    Nielsen, Steffen; Sturup, Stefan; Spliid, Henrik

    1999-01-01

    A rapid, robust, sensitive and selective time-based flow injection (FI) on-line solvent extraction system interfaced with electrothermal atomic absorption spectrometry (ETAAS) is described for analyzing ultra-trace amounts of Cr(VI). The sample is initially mixed on-line with isobutyl methyl ketone...

  17. Investigations into the Role of Modifiers for Entrapment of Hydrides in Flow Injection Hydride Generation Electrothermal Atomic Absorption Spectrometry as Exemplified for the Determination of Germanium

    DEFF Research Database (Denmark)

    Hilligsøe, Bo; Andersen, Jens Enevold Thaulov; Hansen, Elo Harald

    1997-01-01

    Pd-conditioned graphite tubes, placed in the furnace of an atomic absorption spectrometry instrument, are used for entrapment of germane as generated in an associated flow injection system. Two different approaches are tested with the ultimate aim to allow multiple determinations, that is, introd...

  18. Determination of bismuth by dielectric barrier discharge atomic absorption spectrometry coupled with hydride generation: Method optimization and evaluation of analytical performance

    Czech Academy of Sciences Publication Activity Database

    Kratzer, Jan; Boušek, J.; Sturgeon, R. E.; Mester, Z.; Dědina, Jiří

    2014-01-01

    Roč. 86, č. 19 (2014), s. 9620-9625 ISSN 0003-2700 Grant - others:GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 5.636, year: 2014

  19. Confocal absorption spectral imaging of MoS2: optical transitions depending on the atomic thickness of intrinsic and chemically doped MoS2.

    Science.gov (United States)

    Dhakal, Krishna P; Duong, Dinh Loc; Lee, Jubok; Nam, Honggi; Kim, Minsu; Kan, Min; Lee, Young Hee; Kim, Jeongyong

    2014-11-07

    We performed a nanoscale confocal absorption spectral imaging to obtain the full absorption spectra (over the range 1.5-3.2 eV) within regions having different numbers of layers and studied the variation of optical transition depending on the atomic thickness of the MoS2 film. Three distinct absorption bands corresponding to A and B excitons and a high-energy background (BG) peak at 2.84 eV displayed a gradual redshift as the MoS2 film thickness increased from the monolayer, to the bilayer, to the bulk MoS2 and this shift was attributed to the reduction of the gap energy in the Brillouin zone at the K-point as the atomic thickness increased. We also performed n-type chemical doping of MoS2 films using reduced benzyl viologen (BV) and the confocal absorption spectra modified by the doping showed a strong dependence on the atomic thickness: A and B exciton peaks were greatly quenched in the monolayer MoS2 while much less effect was shown in larger thickness and the BG peak either showed very small quenching for 1 L MoS2 or remained constant for larger thicknesses. Our results indicate that confocal absorption spectral imaging can provide comprehensive information on optical transitions of microscopic size intrinsic and doped two-dimensional layered materials.

  20. 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, N2O/C2H2 flame) was used to evaluate Si content in biomass and ash, after a microwave-assisted acid digestion with HNO3 and HF. HR-CS GF AAS (Tpyr = 1400°C, Tatom = 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. Si remained mostly

  1. Monte Carlo Technique Used to Model the Degradation of Internal Spacecraft Surfaces by Atomic Oxygen

    Science.gov (United States)

    Banks, Bruce A.; Miller, Sharon K.

    2004-01-01

    Atomic oxygen is one of the predominant constituents of Earth's upper atmosphere. It is created by the photodissociation of molecular oxygen (O2) into single O atoms by ultraviolet radiation. It is chemically very reactive because a single O atom readily combines with another O atom or with other atoms or molecules that can form a stable oxide. The effects of atomic oxygen on the external surfaces of spacecraft in low Earth orbit can have dire consequences for spacecraft life, and this is a well-known and much studied problem. Much less information is known about the effects of atomic oxygen on the internal surfaces of spacecraft. This degradation can occur when openings in components of the spacecraft exterior exist that allow the entry of atomic oxygen into regions that may not have direct atomic oxygen attack but rather scattered attack. Openings can exist because of spacecraft venting, microwave cavities, and apertures for Earth viewing, Sun sensors, or star trackers. The effects of atomic oxygen erosion of polymers interior to an aperture on a spacecraft were simulated at the NASA Glenn Research Center by using Monte Carlo computational techniques. A two-dimensional model was used to provide quantitative indications of the attenuation of atomic oxygen flux as a function of the distance into a parallel-walled cavity. The model allows the atomic oxygen arrival direction, the Maxwell Boltzman temperature, and the ram energy to be varied along with the interaction parameters of the degree of recombination upon impact with polymer or nonreactive surfaces, the initial reaction probability, the reaction probability dependence upon energy and angle of attack, degree of specularity of scattering of reactive and nonreactive surfaces, and the degree of thermal accommodation upon impact with reactive and non-reactive surfaces to be varied to allow the model to produce atomic oxygen erosion geometries that replicate actual experimental results from space. The degree of

  2. Determination of platinum traces contamination by graphite furnace atomic absorption spectrometry after preconcentration by cloud point extraction

    Energy Technology Data Exchange (ETDEWEB)

    Chappuy, M. [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France); Caudron, E., E-mail: eric.caudron@eps.aphp.fr [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France); Groupe de Chimie Analytique de Paris-Sud, EA 4041, IFR 141, School of Pharmacy, Univ Paris-Sud, 92296 Chatenay-Malabry (France); Bellanger, A. [Department of Pharmacy, Pitie-Salpetriere Hospital (Paris Public Hospital Authority), 47 boulevard de l' hopital, 75013 Paris (France); Pradeau, D. [Analytical Development Laboratory, Pharmaceutical Establishment of Paris Hospitals, 7 rue du Fer a Moulin, 75005 Paris (France)

    2010-04-15

    A simple and sensitive method is described for the determination of platinum surface contamination originating from cisplatin, carboplatin and oxaliplatin. Following extraction from swabs and preconcentration with the cloud point extraction (CPE) method, detection was by graphite furnace atomic absorption spectrometry (GFAAS). After desorption of platinum compounds from the swab, CPE involved on preconcentration of platinum in aqueous solution with diethyldithiocarbamate (DDTC) as chelating agent and Triton X-114 as extraction medium. DDTC is not only a chelating agent, but may also be a good candidate for the inactivation of platinum compounds. DDTC is recommended by the Word Health Organization (WHO) for the destruction of platinum-based anticancer drugs. The main factors affecting CPE efficiency, pH of the sample solution, concentrations of DDTC and Triton X-114, equilibration temperature and incubation time, were evaluated in order to enhance sensitivity of the method. The desorption of platinum compounds from the swab was investigated in parallel. Since platinum is bound to DDTC, it must exchange with copper in order to enhance platinum atomizing by GFAAS. A preconcentration factor of 29 was obtained for 10 mL of a platinum solution at 10 {mu}g mL{sup -1}. In optimal conditions, the limit of detection was 0.2 ng mL{sup -1}, corresponding to 2.0 ng of platinum metal on the swab. Absorbance was linear between 0.7 and 15 ng mL{sup -1}. The proposed method was applied for the determination of surface contamination by platinum compounds with correct results.

  3. X-ray photoelectron spectroscopy study of pyrolytically coated graphite platforms submitted to simulated electrothermal atomic absorption spectrometry conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz, Frine [Laboratorio de Quimica Analitica, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela); Benzo, Zully [Laboratorio de Quimica Analitica, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela); Quintal, Manuelita [Laboratorio de Quimica Analitica, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela); Garaboto, Angel [Laboratorio de Quimica Analitica, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela); Albornoz, Alberto [Laboratorio de Fisicoquimica de Superficies, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela); Brito, Joaquin L. [Laboratorio de Fisicoquimica de Superficies, Centro de Quimica, Instituto Venezolano de Investigaciones Cientificas, IVIC, Apartado Postal 21827, Caracas 1020-A (Venezuela)]. E-mail: joabrito@ivic.ve

    2006-10-15

    The present work is part of an ongoing project aiming to a better understanding of the mechanisms of atomization on graphite furnace platforms used for electrothermal atomic absorption spectrometry (ETAAS). It reports the study of unused pyrolytic graphite coated platforms of commercial origin, as well as platforms thermally or thermo-chemically treated under simulated ETAAS analysis conditions. X-ray photoelectron spectroscopy (XPS) was employed to study the elements present at the surfaces of the platforms. New, unused platforms showed the presence of molybdenum, of unknown origin, in concentrations up to 1 at.%. Species in two different oxidations states (Mo{sup 6+} and Mo{sup 2+}) were detected by analyzing the Mo 3d spectral region with high resolution XPS. The analysis of the C 1s region demonstrated the presence of several signals, one of these at 283.3 eV related to the presence of Mo carbide. The O 1s region showed also various peaks, including a signal that can be attributed to the presence of MoO{sub 3}. Some carbon and oxygen signals were consistent with the presence of C=O and C-O- (probably C-OH) groups on the platforms surfaces. Upon thermal treatment up to 2900 deg. C, the intensity of the Mo signal decreased, but peaks due to Mo oxides (Mo{sup 6+} and Mo{sup 5+}) and carbide (Mo{sup 2+}) were still apparent. Thermo-chemical treatment with 3 vol.% HCl solutions and heating up to 2900 deg. C resulted in further diminution of the Mo signal, with complete disappearance of Mo carbide species. Depth profiling of unused platforms by Ar{sup +} ion etching at increasing time periods demonstrated that, upon removal of several layers of carbonaceous material, the Mo signal disappears suggesting that this contamination is present only at the surface of the pyrolytic graphite platform.

  4. Remote sensing of atmospheric NO2 by employing the continuous-wave differential absorption lidar technique.

    Science.gov (United States)

    Mei, Liang; Guan, Peng; Kong, Zheng

    2017-10-02

    Differential absorption lidar (DIAL) technique employed for remote sensing has been so far based on the sophisticated narrow-band pulsed laser sources, which require intensive maintenance during operation. In this work, a continuous-wave (CW) NO2 DIAL system based on the Scheimpflug principle has been developed by employing a compact high-power CW multimode 450 nm laser diode as the light source. Laser emissions at the on-line and off-line wavelengths of the NO2 absorption spectrum are implemented by tuning the injection current of the laser diode. Lidar signals are detected by a 45° tilted area CCD image sensor satisfying the Scheimpflug principle. Range-resolved NO2 concentrations on a near-horizontal path are obtained by the NO2 DIAL system in the range of 0.3-3 km and show good agreement with those measured by a conventional air pollution monitoring station. A detection sensitivity of ± 0.9 ppbv at 95% confidence level in the region of 0.3-1 km is achieved with 15-minute averaging and 700 m range resolution during hours of darkness, which allows accurate concentration measurement of ambient NO2. The low-cost and robust DIAL system demonstrated in this work opens up many possibilities for field NO2 remote sensing applications.

  5. A novel self-sensing technique for tapping-mode atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ruppert, Michael G.; Moheimani, S. O. Reza [The University of Newcastle, University Drive, Callaghan NSW 2308 (Australia)

    2013-12-15

    This work proposes a novel self-sensing tapping-mode atomic force microscopy operation utilizing charge measurement. A microcantilever coated with a single piezoelectric layer is simultaneously used for actuation and deflection sensing. The cantilever can be batch fabricated with existing micro electro mechanical system processes. The setup enables the omission of the optical beam deflection technique which is commonly used to measure the cantilever oscillation amplitude. Due to the high amount of capacitive feedthrough in the measured charge signal, a feedforward control technique is employed to increase the dynamic range from less than 1 dB to approximately 35 dB. Experiments show that the conditioned charge signal achieves excellent signal-to-noise ratio and can therefore be used as a feedback signal for atomic force microscopy imaging.

  6. Absorption characteristics of an acoustic material at oblique incidence measured with the two-microphone technique

    Science.gov (United States)

    Minten, M.; Cops, A.; Lauriks, W.

    1988-02-01

    The two-microphone technique has been extended to the direct determination of the specific acoustic impedance, which is one of the basic quantities in acoustics. This method can be used to determine some acoustical characteristics of an absorbing sample (such as the reflection coefficient, characteristic acoustic impedance, and sound absorption coefficient) from the specific acoustic impedance. All measurements have been carried out in an anechoic room. It will be shown that the distance to the sample and the microphone spacing are critical parameters due to the standing waves in front of the sample. Some simple theoretical models are used to evaluate the accuracy of the results. At normal incidence the results are also compared with the results of Kundt tube measurements.

  7. Understanding refraction contrast using a comparison of absorption and refraction computed tomographic techniques

    Science.gov (United States)

    Wiebe, S.; Rhoades, G.; Wei, Z.; Rosenberg, A.; Belev, G.; Chapman, D.

    2013-05-01

    Refraction x-ray contrast is an imaging modality used primarily in a research setting at synchrotron facilities, which have a biomedical imaging research program. The most common method for exploiting refraction contrast is by using a technique called Diffraction Enhanced Imaging (DEI). The DEI apparatus allows the detection of refraction between two materials and produces a unique ''edge enhanced'' contrast appearance, very different from the traditional absorption x-ray imaging used in clinical radiology. In this paper we aim to explain the features of x-ray refraction contrast as a typical clinical radiologist would understand. Then a discussion regarding what needs to be considered in the interpretation of the refraction image takes place. Finally we present a discussion about the limitations of planar refraction imaging and the potential of DEI Computed Tomography. This is an original work that has not been submitted to any other source for publication. The authors have no commercial interests or conflicts of interest to disclose.

  8. Spectral fluorescence signature techniques and absorption measurements for continuous monitoring of biofuel-producing microalgae cultures

    Science.gov (United States)

    Martín de la Cruz, M. C.; Gonzalez Vilas, L.; Yarovenko, N.; Spyrakos, E.; Torres Palenzuela, J. M.

    2013-08-01

    Biofuel production from microalgae can be both sustainable and economically viable. Particularly in the case of algal growth in wastewater an extra benefit is the removal or biotransformation of pollutants from these types of waters. A continuous monitoring system of the microalgae status and the concentration of different wastewater contaminants could be of great help in the biomass production and the water characterisation. In this study we present a system where spectral fluorescence signature (SFS) techniques are used along with absorption measurements to monitor microalgae cultures in wastewater and other mediums. This system aims to optimise the microalgae production for biofuel applications or other uses and was developed and tested in prototype indoor photo-bioreactors at the University of Vigo. SFS techniques were applied using the fluorescence analyser INSTAND-SCREENER developed by Laser Diagnostic Instruments AS. INSTAND-SCREENER permits wavelength scanning in two modes, one in UV and another in VIS. In parallel, it permits the on-line monitoring and rapid analysis of both water quality and phytoplankton status without prior treatment of the sample. Considering that different contaminants and microalgae features (density, status etc.) have different spectral signatures of fluorescence and absorption properties, it is possible to characterise them developing classification libraries. Several algorithms were used for the classification. The implementation of this system in an outdoor raceway reactor in a Spanish wastewater treatment plant is also discussed. This study was part of the Project EnerBioAlgae (http://www.enerbioalgae.com/), which was funded by the Interreg SUDOE and led by the University of Vigo.

  9. Benefits of atomic-level processing by quasi-ALE and ALD technique

    Science.gov (United States)

    Honda, M.; Katsunuma, T.; Tabata, M.; Tsuji, A.; Oishi, T.; Hisamatsu, T.; Ogawa, S.; Kihara, Y.

    2017-06-01

    A new technology has been developed using the atomic layer etching (ALE) and atomic layer deposition (ALD) concepts. It has been applied to self-aligned contacts (SAC) and patterning processes, for the sub 7 nm technology generation. In the SAC process, ultra-high selectivity of SiO2 etching towards SiN is required, for which we have developed quasi-ALE technique for SiO2 etching. We were able to significantly improve the trade-off between the etching ability of SiO2 on the micro slit portions and SiN selectivity. Quasi-ALE precisely controls the reaction layer thickness of the surface, by controlling the radical flux and ion flux independently, and hence enables etching at lower ion energies (E i  <  250 eV). On the other hand, in the patterning processes, the shrinking of critical dimensions (CD) without loading is mandatory. Therefore, we developed a new process flow that combines ALD technique and etching. With this method, we were able to achieve CD shrinking at atomic-layer level precision for various patterns, without causing CD loading. In addition, we were also able to uniformly control the CD shrinkage amount across the whole wafer. This is because this technique takes advantage of the deposition step which is independent of the pattern density and the location on the wafer by self-limited reactions.

  10. Vitamin A equivalency and apparent absorption of beta-carotene in ileostomy subjects using a dual-isotope dilution technique.

    NARCIS (Netherlands)

    Loo-Bouwman, C.A. Van; Naber, T.H.; Breemen, R.B. van; Zhu, D.; Dicke, H.; Siebelink, E.; Hulshof, P.J.; Russel, F.G.M.; Schaafsma, G.; West, C.E.

    2010-01-01

    The objective was to quantify the vitamin A equivalency of beta-carotene in two diets using a dual-isotope dilution technique and the apparent beta-carotene absorption as measured by the oral-faecal balance technique. Seventeen healthy adults with an ileostomy completed the 4-week diet-controlled,

  11. Determination of some heavy metals in food and environmental samples by flame atomic absorption spectrometry after coprecipitation.

    Science.gov (United States)

    Soylak, Mustafa; Aydin, Ayse

    2011-06-01

    A novel preconcentration procedure based coprecipitation of Cu(II), Co(II), Cd(II), Ni(II), Mn(II), Fe(III) and Pb(II) on thulium hydroxide precipitate has been presented prior to flame atomic absorption spectrometric determination of them in environmental samples. The analytical parameters that influenced the quantitative coprecipitation of analytes including amount of thulium, pH, duration time, etc. were investigated. The effects of alkali, earth alkali, and some transition metals on the recoveries were also studied. Under the optimized conditions, the detection limits (3 sigma, N=10) for the analytes were in the range of 0.1-1.6 μg/L, respectively. The validation of the presented coprecipitation method was checked by the analysis of certified reference materials (TMDA 54.4 fortified lake water and HR-1 Humber river sediment). The proposed coprecipitation method has been successfully applied for the determination of traces of copper, cobalt, cadmium, nickel, manganese, iron and lead in food and environmental samples. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Determination of ultra-trace aluminum in human albumin by cloud point extraction and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Sun, Mei; Wu, Qianghua

    2010-04-15

    A cloud point extraction (CPE) method for the preconcentration of ultra-trace aluminum in human albumin prior to its determination by graphite furnace atomic absorption spectrometry (GFAAS) had been developed in this paper. The CPE method was based on the complex of Al(III) with 1-(2-pyridylazo)-2-naphthol (PAN) and Triton X-114 was used as non-ionic surfactant. The main factors affecting cloud point extraction efficiency, such as pH of solution, concentration and kind of complexing agent, concentration of non-ionic surfactant, equilibration temperature and time, were investigated in detail. An enrichment factor of 34.8 was obtained for the preconcentration of Al(III) with 10 mL solution. Under the optimal conditions, the detection limit of Al(III) was 0.06 ng mL(-1). The relative standard deviation (n=7) of sample was 3.6%, values of recovery of aluminum were changed from 92.3% to 94.7% for three samples. This method is simple, accurate, sensitive and can be applied to the determination of ultra-trace aluminum in human albumin. 2009 Elsevier B.V. All rights reserved.

  13. Determination of molybdenum in plants by vortex-assisted emulsification solidified floating organic drop microextraction and flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Oviedo, Jenny A.; Fialho, Lucimar L.; Nóbrega, Joaquim A., E-mail: djan@terra.com.br

    2013-08-01

    A fast and sensitive procedure for extraction and preconcentration of molybdenum in plant samples based on solidified floating organic drop microextraction combined with flame atomic absorption spectrometry and discrete nebulization was developed. 8-Hydroxyquinoline (8-HQ) was used as complexing agent. The experimental conditions established were: 0.5% m v{sup −1} of 8-HQ, 60 μL of 1-undecanol as the extractant phase, 2 min vortex extraction time, centrifugation for 2 min at 2000 rpm, 10 min into an ice bath and discrete nebulization by introducing 200 μL of solution. The calibration curve was linear from 0.02 to 4.0 mg L{sup −1} with a limit of detection of 4.9 μg L{sup −1} and an enhancement factor of 67. The relative standard deviations for ten replicate measurements of 0.05 and 1.0 mg L{sup −1} Mo were 6.0 and 14.5%, respectively. The developed procedure was applied for determining molybdenum in corn samples and accuracy was proved using certified reference materials. - Highlights: ► Molybdenum was determined in plants by flame AAS. ► Flame AAS sensitivity was improved using microextraction and discrete nebulization. ► The developed procedure can be easily implemented in routine analysis. ► Green chemistry principles are followed.

  14. Trace metal characterization and speciation in geothermal effluent by multiple scanning anodic stripping voltammetry and atomic absorption analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, B.R.

    1979-05-25

    Recent studies have shown geothermal power plants to have a significant environmental impact on the ground water of the area. The heavy metals arsenic and mercury are special problems, as both are concentrated by flora and fauna exposed to the effluent waters. Because the toxicity of these and other metallic pollutants present in geothermal effluent depends on the chemical form, or speciation, of the particular metal, any serious study of the environmental impact of a geothermal development should include studies of trace metal speciation, in addition to trace metal concentration. This proposal details a method for determining metal speciation in dilute waters. The method is based on ion-exchange and backed by atomic absorption spectrometry and multiple scanning anodic stripping voltammetry. Special laboratory studies will be performed on mercury, arsenic and selenium speciation in synthetic geothermal water. The method will be applied to three known geothermal areas in Washington and Oregon, with emphasis on the speciation of mercury, arsenic and selenium in these waters. The computer controlled electrochemical instrumentation was built and tested. Using this instrumentation, a new experimental procedure was developed to determine the chemical form (speciation) of metal ions in very dilute solutions (ng/ml). This method was tested on model systems including Pb, Cd, and As with C1/sup -/, CO/sub 3//sup 2 -/ and glycine ligands. Finally, the speciation of lead in a geothermal water was examined and the PbC1/sup +/ complex was observed and quantified.

  15. Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    Fabio G. Santomauro

    2017-07-01

    Full Text Available We report on an element-selective study of the fate of charge carriers in photoexcited inorganic CsPbBr3 and CsPb(ClBr3 perovskite nanocrystals in toluene solutions using time-resolved X-ray absorption spectroscopy with 80 ps time resolution. Probing the Br K-edge, the Pb L3-edge, and the Cs L2-edge, we find that holes in the valence band are localized at Br atoms, forming small polarons, while electrons appear as delocalized in the conduction band. No signature of either electronic or structural changes is observed at the Cs L2-edge. The results at the Br and Pb edges suggest the existence of a weakly localized exciton, while the absence of signatures at the Cs edge indicates that the Cs+ cation plays no role in the charge transport, at least beyond 80 ps. This first, time-resolved element-specific study of perovskites helps understand the rather modest charge carrier mobilities in these materials.

  16. Sensitive determination of cadmium in water samples by room temperature ionic liquid-based preconcentration and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martinis, Estefania M. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Olsina, Roberto A. [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis (Argentina); Altamirano, Jorgelina C. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina); Wuilloud, Rodolfo G. [Laboratory of Environmental Research and Services of Mendoza (LISAMEN), (CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martin, C.C. 131, M 5502 IRA Mendoza (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)], E-mail: rwuilloud@mendoza-conicet.gov.ar

    2008-10-17

    A sensitive preconcentration methodology for Cd determination at trace levels in water samples was developed in this work. 1-Butyl-3-methylimidazolium hexafluorophosphate ([C{sub 4}MIM][PF{sub 6}]) room temperature ionic liquid (RTIL) was successfully used for Cd preconcentration, as cadmium-2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex [Cd-5-Br-PADAP]. Subsequently, Cd was back-extracted from the RTIL phase with 500 {mu}L of 0.5 mol L{sup -1} nitric acid and determined by electrothermal atomic absorption spectrometry (ETAAS). A preconcentration factor of 40 was achieved with 20 mL of sample. The limit of detection (LOD) obtained under optimum conditions was 3 ng L{sup -1} and the relative standard deviation (R.S.D.) for 10 replicates at 1 {mu}g L{sup -1} Cd{sup 2+} concentration level was 3.5%, calculated at peak heights. The calibration graph was linear from concentration levels near the detection limits up to at least 5 {mu}g L{sup -1}. A correlation coefficient of 0.9997 was achieved. Validation of the methodology was performed by standard addition method and analysis of certified reference material (CRM). The method was successfully applied to the determination of Cd in river and tap water samples.

  17. Separation and preconcentration of trace amounts of gold from water samples prior to determination by flame atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Fatemeh Sabermahani

    2016-11-01

    Full Text Available A preconcentration/separation procedure is presented for the solid phase extraction of trace gold(III as its rubeanic acid (dithiooxamide chelate on silica gel, prior to determination by flame atomic absorption spectrometry. The influences of analytical parameters including pH of the aqueous solution, the amount of the sorbent, time of the complex formation, ligand amount, flow rates of sample and elution solutions and the type, concentration and volume of elution solution on the quantitative recoveries of Au(III were investigated. At pH 3.5, the maximum sorption capacity of Au3+ was 7.5 mg g−1, by column method. The linearity was maintained in the concentration range of 1.0–3.4 × 104 ng mL−1 for gold in the original solution. The preconcentration factor of 100 and relative standard deviation of ±1.7% were obtained, under optimum conditions. The limit of detection (LOD was calculated as 0.80 ng mL−1, based on 3σbl/m (n = 8 in the original solutions. The proposed method was successfully applied to the determination trace amounts of gold in the water samples.

  18. Multiwalled carbon nanotubes microcolumn preconcentration and determination of gold in geological and water samples by flame atomic absorption spectrometry

    Science.gov (United States)

    Liang, Pei; Zhao, Ehong; Ding, Qiong; Du, Dan

    2008-06-01

    The potential of multiwalled carbon nanotubes (MWNTs) as solid-phase extraction adsorbent for the separation and preconcentration of gold has been investigated. Gold could be adsorbed quantitatively on MWNTs in the pH range of 1-6, and then eluted completely with 2 mL of 3% thiourea in 1 mol L - 1 HCl solution at a flow rate of 0.5 mL min - 1 . A new method using a microcolumn packed with MWNTs as sorbent has been developed for the preconcentration of trace amount of Au prior to its determination by flame atomic absorption spectrometry. Parameters influencing the preconcentration of Au, such as pH of the sample, sample flow rate and volume, elution solution and interfering ions, have been examined and optimized. Under the optimum experimental conditions, the detection limit of this method for Au was 0.15 µg L - 1 with an enrichment factor of 75, and the relative standard deviation (R.S.D) was 3.1% at the 100 µg L - 1 Au level. The method has been applied for the determination of trace amount of Au in geological and water samples with satisfactory results.

  19. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Teslima Daşbaşı

    2016-01-01

    Full Text Available A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4- complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time were studied in detail. The effect of interfering ions on the analyte recovery was also investigated. The calibration graph was linear in the range of 0.040–1.00 mg L−1 with detection limit of 4.0 μg L−1 (n=13. The precision as relative standard deviation was 3% (n=11, 0.20 mg L−1 and the enrichment factor was 74. The developed method was applied successfully for the determination of bismuth in various water, pharmaceutical, and cosmetic samples and the certified reference material (TMDA-64 lake water.

  20. 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.

  1. Total mercury determination in different tissues of broiler chicken by using cloud point extraction and cold vapor atomic absorption spectrometry.

    Science.gov (United States)

    Shah, A Q; Kazi, T G; Baig, J A; Afridi, H I; Kandhro, G A; Arain, M B; Kolachi, N F; Wadhwa, S K

    2010-01-01

    A cloud point extraction (CPE) method has been developed for the determination of total mercury (Hg) in different tissues of broiler chicken by cold vapor atomic absorption spectrometry (CVAAS). The broiler chicken tissues (leg, breast, liver and heart) were subjected to microwave assisted digestion in a mixture of nitric acid and hydrogen peroxide (2:1 ratio), prior to preconcentration by CPE. Various parameters such as the amount of ammonium O,O-diethyldithiophosphate (DDTP), concentrations of Triton X-114, equilibrium temperature, time and centrifugation have been studied in order to find the best conditions for the determination of mercury. For validation of proposed method a certified reference material, DORM-2 was used. No significant difference p>0.05 was observed between the experimental results and the certified values of CRM (paired t-test). The limit of detection and quantitation obtained under the optimal conditions were 0.117 and 0.382 microg/kg, respectively. The accumulation of Hg in different tissues were found in the order of, liver>muscles>heart. The concentration of Hg in chicken tissues were found in the range of 1.57-2.75, 1.40-2.27, 1.55-4.22, and 1.39-2.61 microg/kg in leg, breast, liver and heart, respectively. Copyright 2009 Elsevier Ltd. All rights reserved.

  2. Standard test method for graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 g/mL and cadmium concentrations greater than 0.0005 to 0.002 g/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination cont...

  3. In-situ suspended aggregate microextraction of gold nanoparticles from water samples and determination by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Choleva, Tatiana G; Kappi, Foteini A; Tsogas, George Z; Vlessidis, Athanasios G; Giokas, Dimosthenis L

    2016-05-01

    This work describes a new method for the extraction and determination of gold nanoparticles in environmental samples by means of in-situ suspended aggregate microextraction and electrothermal atomic absorption spectrometry. The method relies on the in-situ formation of a supramolecular aggregate phase through ion-association between a cationic surfactant and a benzene sulfonic acid derivative. Gold nanoparticles are physically entrapped into the aggregate phase which is separated from the bulk aqueous solution by vacuum filtration on the surface of a cellulose filter in the form of a thin film. The film is removed from the filter surface and is dissociated into an acidified methanolic solution which is used for analysis. Under the optimized experimental conditions, gold nanoparticles can be efficiently extracted from water samples with recovery rates between 81.0-93.3%, precision 5.4-12.0% and detection limits as low as 75femtomolL(-1) using only 20mL of sample volume. The satisfactory analytical features of the method along with the simplicity indicate the efficiency of this new approach to adequately collect and extract gold nanoparticle species from water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. 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.

  5. Determining the arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillets from Vietnam.

    Science.gov (United States)

    Molognoni, Luciano; Vitali, Luciano; Ploêncio, Leandro As; Santos, Jacson N; Daguer, Heitor

    2016-07-01

    Pangasius is a fish produced on a large scale in Vietnam and exported to many countries. Since river contamination from human activities can affect the safety of this food, fish consumption can cause exposure to potentially toxic elements for humans. The aim of this study, therefore, was to assess arsenic, cadmium, lead, copper and chromium contents by atomic absorption spectrometry in Pangasius fillet produced in the provinces of Dong Thap and Can Tho (Vietnam) and exported to Brazil. The limits of detection were: arsenic 0.5443 µg kg(-1) , cadmium 0.0040 mg kg(-1) , chromium 0.0004 mg kg(-1) , copper 0.0037 mg kg(-1) and lead 0.0284 mg kg(-1) . Analysis of 20 samples showed results below the limit of detection for arsenic, chromium and lead, while copper average concentration was 0.0234 mg kg(-1) . Cadmium average concentration was 0.0547 mg kg(-1) , with no significant difference between the two regions studied. The samples of Pangasius had no detectable concentrations of arsenic, chromium, copper and lead, and do not represent a hazard to public health. However, cadmium analysis revealed non-compliant samples, demonstrating the importance of monitoring the quality of imported Pangasius fish. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  6. Comparative study of pretreatment methods for the determination of metals in atmospheric aerosol by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Karanasiou, A A; Thomaidis, N S; Eleftheriadis, K; Siskos, P A

    2005-03-15

    A comparative study of pretreatment methods for the determination of 10 elements (As, Cd, Pb, V, Ni, Mn, Cr, Cu, Fe, Al) in atmospheric aerosols by electrothermal atomic absorption spectrometry (ETAAS) was conducted. For the digestion of the particulates collected in filters, six methods were compared using a mixture of HNO(3) and HF with or without the addition of various oxidative agents (HClO(4) or H(2)O(2)) or acids (HCl). The comparative study was performed using loaded cellulose filter samples, which were digested in Parr bombs and heated in a conventional oven at 170 degrees C for 5h. The extraction efficiency and blanks were compared and it was proved that the digestion method using only HNO(3)-HF extracted most of the metals and gave the lowest blanks. The HNO(3)-HF mixture was selected for the development of an improved microwave digestion method specific for aerosol-loaded filters. The operating parameters were optimized, so that quantitative recovery of the reference materials NIST 1649a urban dust and NIST 1648 urban particulate matter was achieved. The blank of cellulose and teflon filters were also determined and compared. Teflon filters present the lowest blanks for all the elements. The obtained limits of detection for each type of filters were adequate for environmental monitoring purposes. ETAAS instrumental operation was also optimized for the compensation and the elimination of interferences. The temperature optimization was performed for each metal in every type of filter and optimized parameters are proposed for 10 elements.

  7. Investigation of the levels of some element in edible oil samples produced in Turkey by atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Mendil, Durali, E-mail: dmendil@gop.edu.tr [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Uluoezlue, Ozguer Dogan; Tuezen, Mustafa [Gaziosmanpasa University, Faculty of Science and Arts, Chemistry Department, 60250 Tokat (Turkey); Soylak, Mustafa [Erciyes University, Faculty of Science and Arts, Department of Chemistry, 38039 Kayseri (Turkey)

    2009-06-15

    The element contents (Fe, Mn, Zn, Cu, Pb, Co, Cd, Na, K, Ca and Mg) in edible oils (olive oil, hazelnut oil, sunflower oil, margarine, butter and corn oil) from Turkey were determined using atomic absorption spectrometry after microwave digestion. The concentrations of trace element in the samples were found to be 291.0-52.0, 1.64-0.04, 3.08-1.03, 0.71-0.05, 0.03-0.01, 1.30-0.50, 84.0-0.90, 50.1-1.30, 174.2-20.8 and 20.8-0.60 {mu}g/g for iron, manganese, zinc, copper, lead, cobalt, sodium, potassium, calcium, and magnesium, respectively. Cadmium was found to be 4.57-0.09 {mu}g/kg. The high heavy metal and minerals accumulation levels in the samples were found in olive oil for Cu, Pb, Co, margarine for Fe, K, corn oil for Zn, Mn, butter for Na, Mg, sunflower oil for Ca and hazelnut oil for Cd, respectively.

  8. Local atomic structure in iron copper binary alloys: An extended X-ray absorption fine structure study

    Energy Technology Data Exchange (ETDEWEB)

    Kuri, G. [LWV, NES, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland)]. E-mail: goutam.kuri@psi.ch; Degueldre, C. [LWV, NES, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Bertsch, J. [LWV, NES, Paul Scherrer Institute, 5232 Villigen PSI (Switzerland); Rothe, J. [INE, Forschungszentrum Karlsruhe, 76344 Karlsruhe (Germany)

    2007-05-31

    Understanding the clustering process and the evolution of the precipitate structure of copper in Fe-Cu system is an important step in the description of material hardening and the embrittlement process normally observed under irradiation conditions. In this work, an extended X-ray absorption fine structure (EXAFS) spectroscopy characterization of Fe-0.3 wt%Cu and Fe-1.0 wt%Cu binary model alloys has been performed in order to investigate the local structure around Cu and Fe atoms in the matrix. The effect of thermal ageing was studied on one Fe-Cu specimen containing 1.0 wt% Cu annealed at 775 K for a duration of 1 h. The near-neighbour environment of Cu and Fe was examined by determining the best-fit structural parameters after curve fitting to the first-few-shells EXAFS functions. The results provide an indication of the formation of sub-nanometer-size Cu clusters in Fe matrix for the specimens examined. The average structural parameters estimated from the EXAFS data are presented and discussed.

  9. Back-extraction of trace elements from organometallic-halide extracts for determination by flameless atomic absorption spectrometry

    Science.gov (United States)

    Clark, J.R.; Viets, J.G.

    1981-01-01

    The Methyl isobutyl ketone-Amine synerGistic Iodkte Complex (MAGIC) extraction system offers the advantage that a large number of trace elements can be rapidly determined with a single sample preparation procedure. However, many of the elements extracted by the MAGIC system form volatile organometallic halide salts when the organic extract is heated in the graphite furnace. High concentrations of some elements such as Cu and Zn extracted by the system from anomalous geological samples produce serious interferences when certain other elements are determined by flameless atomic absorption. Stripping systems have been developed using solutions of HNO3, H2SO4, and CH3COOH individually or combined with H2O2 in order to circumvent these problems. With these systems most of the elements in the organic extract can be sequentially stripped into an aqueous phase. Organometallic volatilization and the most serious interelement interferences, therefore, can be eliminated by stripping with various combinations of reagents in a series of steps.

  10. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry

    Science.gov (United States)

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

    2016-01-01

    A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4 − complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time were studied in detail. The effect of interfering ions on the analyte recovery was also investigated. The calibration graph was linear in the range of 0.040–1.00 mg L−1 with detection limit of 4.0 μg L−1 (n = 13). The precision as relative standard deviation was 3% (n = 11, 0.20 mg L−1) and the enrichment factor was 74. The developed method was applied successfully for the determination of bismuth in various water, pharmaceutical, and cosmetic samples and the certified reference material (TMDA-64 lake water). PMID:26881186

  11. Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product

    Science.gov (United States)

    Bianchin, Joyce Nunes; Martendal, Edmar; Carasek, Eduardo

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precision were 3.4 μg L−1 and 3.8% (n = 6, 15 μg L−1), respectively. The enrichment factor and the linear working range were, respectively, 21 and 10–50 μg L−1. Results for recovery tests using different water samples were between 96 and 107%. The proposed methodology was applied with success for the determination of Ag in water used to wash clothes impregnated with silver nanoparticles, supplied by a factory located in Santa Catarina, Brazil. PMID:21804766

  12. Slurry sampling hydride generation atomic absorption spectrometry for the determination of extractable/soluble As in sediment samples

    Science.gov (United States)

    Mierzwa, Jerzy; Dobrowolski, Ryszard

    1998-01-01

    A method combining the sampling of slurry pretreated by ultrasonic agitation and microwave assisted extraction with hydride generation atomic absorption spectrometry (HGAAS) for the determination of arsenic in sediment samples is proposed and evaluated. The pretreatment of slurried samples by ultrasonication enabled the extraction of (approximately) up to 85% of arsenic from the studied sediment samples. The further (slight) improvement of the efficiency of extraction was accomplished by the introduction of a short microwave-accelerated treatment. L-cysteine was used as an efficient pre-reduction reagent. The accuracy and precision of the slurry sampling HGAAS method were studied using the certified reference materials: Sediment GBW 30043 (NRCCRM, People's Republic of China), Sediment NIST 2704 (NIST, USA) and Marine Sediment BCSS-1 (NRCC, Canada). The relative standard deviation of the full (overall) analytical procedure was 8.5% and an absolute limit of detection of 2.75 ng was achieved. Factors which influence the reliability of this method are, for example, the choice of slurry liquid phase (extraction medium), sample homogeneity and, in particular, very effective mixing of slurries.

  13. Determination of cadmium by flame-atomic absorption spectrometry after preconcentration on silica gel modified with cupferron

    Directory of Open Access Journals (Sweden)

    Bortoleto Gisele G.

    2004-01-01

    Full Text Available A method for the determination of cadmium by flame atomic absorption spectrometry (FAAS after its preconcentration onto a column containing silica gel modified with cupferron was developed. The pH, amount of adsorbent material, concentration of eluent, volume of sample and amount of Cd were optimized. The effect of several foreign ions was also investigated and showed that the retention of cadmium depended on the amounts of Zn(II and Cu(II present and that these interferences could be overcome by using a 0.05 mmol KI. An enrichment factor of up to 30 was obtained , the LOD was 0.5 µg L-1 (3sigma and the LOQ was 2.0 µg L-1 (10sigma with rsd of 1.1% (n = 10. The accuracy of the proposed method was ascertained by using certified reference material and the obtained result (3.93 ± 0.01 µg g-1 agrees with the certified value (4.15 ± 0.38 µg g-1. The determination of Cd in nail polish showed quantitative recoveries for the spiked samples. The proposed method is characterized by simplicity, efficiency and low cost.

  14. 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.

  15. Discussion of parameters associated with the determination of arsenic by electrothermal atomic absorption spectrometry in slurried environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Vassileva, E.; Baeten, H.; Hoenig, M. [Centre for Veterinary and Agrochemical Research (CERVA), Tervuren (Belgium)

    2001-01-01

    A slurry sampling - fast program procedure has been developed for the determination of arsenic in plants, soils and sediments by electrothermal atomic absorption spectrometry. Efficiencies of various single and mixed modifiers for thermal stabilization of arsenic and for a better removal of the matrix during pyrolysis step were compared. The influence of the slurry concentration, amounts of modifier and parameters of the pyrolysis step on the As integrated absorbance signals have been studied and a comparison between fast and conventional furnace programs was also made. The ultrasonic agitation of the slurry followed by a fast electrothermal program using an Ir/Mg modifier provides the most consistent performance in terms of precision and accuracy. The reliability of the whole procedure has been compared with results obtained after application of a wet digestion method with an HF step and validated by analyzing eleven certified reference materials. Arsenic detection and quantitation limits expressed on dry sample matter were about 30 and 100 {mu}g kg{sup -1}, respectively. (orig.)

  16. Determination of inorganic arsenic and its organic metabolites in urine by flow-injection hydride generation atomic absorption spectrometry.

    Science.gov (United States)

    Hanna, C P; Tyson, J F; McIntosh, S

    1993-08-01

    A method has been developed for the determination of inorganic arsenic [As(III) and As(V)] and its organic metabolites (monomethylarsenic and dimethylarsenic) in urine by flow-injection hydride generation atomic absorption spectrometry. The nontoxic seafood-derived arsenobetaine and arsenocholine species were first separated by a solid-phase extraction procedure. The remaining sample was digested with a mixture of nitric and sulfuric acids and potassium dichromate, followed by attack with hydrogen peroxide. The resulting As(V) was reduced to As(III) with potassium iodide in hydrochloric acid before injection into the flow-injection manifold. The percentage analytical recoveries (mean +/- 95% confidence interval) of various arsenic species added to a urine specimen at 250 micrograms/L were 108 +/- 2, 112 +/- 11, 104 +/- 7, and 95 +/- 5 for As(III), As(V), monomethylarsenic, and dimethylarsenic, respectively. For the determination of arsenic in Standard Reference Material 2670 (toxic metals in human urine), results agreed with the certified value (480 +/- 100 micrograms/L). Analyses of samples for the Centre de Toxicologie du Quebec, containing seafood-derived species, demonstrated the viability of the separation procedure. Detection limits were between 0.1 and 0.2 microgram/L in the solution injected into the manifold, and precision at 10 micrograms/L was between 2% and 3% (CV). These preliminary results show that the method might be applicable to determinations of arsenic in a range of clinical urine specimens.

  17. Fast sequential determination of antimony and lead in pewter alloys using high-resolution continuum source flame atomic absorption spectrometry.

    Science.gov (United States)

    Dessuy, Morgana B; de Jesus, Robson M; Brandao, Geovani C; Ferreira, Sergio L C; Vale, Maria Goreti R; Welz, Bernhard

    2013-01-01

    A simple method has been developed to determine antimony and lead in pewter alloy cups produced in Brazil, using fast sequential determination by high-resolution continuum source flame atomic absorption spectrometry. The samples were dissolved in HCl and H(2)O(2), employing a cold finger system in order to avoid analyte losses. The main resonance line of lead at 217.001 nm and a secondary line of antimony at 212.739 nm were used. The limits of detection for lead and antimony were 0.02 and 5.7 mg L(-1), respectively. The trueness of the method was established by recovery tests and comparing the results obtained by the proposed method with those obtained by inductively coupled plasma optical emission spectrometry. The results were compared using a student's t-test and there was no significant difference at a 95% confidence interval. With the developed methods, it was possible to determine accurately antimony and lead in pewter samples. The lead concentration found in the analysed samples was around 1 mg g(-1), which means that they are not lead free; however, the content was below the maximum allowed level of 5 mg g(-1). The antimony content, which was found to be between 40 and 46 mg g(-1), is actually of greater concern, as antimony is known to be potentially toxic already at very low concentrations, although there is no legislation yet for this element.

  18. Selective speciation of inorganic antimony on tetraethylenepentamine bonded silica gel column and its determination by graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Mendil, Durali; Bardak, Hilmi; Tuzen, Mustafa; Soylak, Mustafa

    2013-03-30

    A speciation system for antimony (III) and antimony (V) ions that based on solid phase extraction on tetraethylenepentamine bonded silica gel has been established. Antimony was determined by graphite furnace atomic absorption spectrometry (GF-AAS). Analytical conditions including pH, sample volume, etc., were studied for the quantitative recoveries of Sb (III) and Sb (V). Matrix effects on the recovery were also investigated. The recovery values and detection limit for antimony (III) at optimal conditions were found as >95% and 0.020 μg L(-1), respectively. Preconcentration factor was calculated as 50. The capacity of adsorption for the tetraethylenepentamine bonded silica gel was 7.9 mg g(-1). The validation was checked by analysis of NIST SRM 1573a Tomato laves and GBW 07605 Tea certified reference materials. The procedure was successfully applied to speciation of antimony in tap water, mineral water and spring water samples. Total antimony was determined in refined salt, unrefined salt, black tea, rice, tuna fish and soil samples after microwave digestion and presented enrichment method combination. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. 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.

  20. Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy.

    Science.gov (United States)

    Santomauro, Fabio G; Grilj, Jakob; Mewes, Lars; Nedelcu, Georgian; Yakunin, Sergii; Rossi, Thomas; Capano, Gloria; Al Haddad, André; Budarz, James; Kinschel, Dominik; Ferreira, Dario S; Rossi, Giacomo; Gutierrez Tovar, Mario; Grolimund, Daniel; Samson, Valerie; Nachtegaal, Maarten; Smolentsev, Grigory; Kovalenko, Maksym V; Chergui, Majed

    2017-07-01

    We report on an element-selective study of the fate of charge carriers in photoexcited inorganic CsPbBr3 and CsPb(ClBr)3 perovskite nanocrystals in toluene solutions using time-resolved X-ray absorption spectroscopy with 80 ps time resolution. Probing the Br K-edge, the Pb L3-edge, and the Cs L2-edge, we find that holes in the valence band are localized at Br atoms, forming small polarons, while electrons appear as delocalized in the conduction band. No signature of either electronic or structural changes is observed at the Cs L2-edge. The results at the Br and Pb edges suggest the existence of a weakly localized exciton, while the absence of signatures at the Cs edge indicates that the Cs(+) cation plays no role in the charge transport, at least beyond 80 ps. This first, time-resolved element-specific study of perovskites helps understand the rather modest charge carrier mobilities in these materials.

  1. Immersed single-drop microextraction-electrothermal vaporization atomic absorption spectroscopy for the trace determination of mercury in water samples.

    Science.gov (United States)

    Bagheri, Habib; Naderi, Mehrnoush

    2009-06-15

    A new method based on single-drop microextraction (SDME) combined with electrothermal vaporization atomic absorption spectroscopy (ETV-AAS) was developed for the trace determination of mercury in water samples. A microdrop of m-xylene was applied as the extraction solvent. After extraction, the microdrop was introduced, directly, into a graphite furnace of AAS. Some important extraction parameters such as type of solvent, volume of solvent, sample stirring, ionic strength, sample pH, chelating agent concentration, sample temperature, and extraction time were investigated and optimized. The highest possible microdrop volume of 10 microL, a sampling temperature of 27 degrees C, and use of m-xylene containing dithizone, as complexing agent, are major parameters led to achieve a high enrichment factor of 970. Under the optimized conditions, the detection limit of the method was 0.01 microg L(-1) and the relative standard deviation was 6.1% (n=7). The proposed method has been successfully applied to the determination of Hg in two river water samples. The effects of interfering species such as Pt, Pd, Cu, Au, and Bi, having the tendency to form complexes with dithizone, at two concentration levels of 100 and 1000 microg L(-1) were also studied.

  2. Determination of heavy metal contents by atomic absorption spectroscopy (AAS) in some medicinal plants from Pakistani and Malaysian origin.

    Science.gov (United States)

    Akram, Sobia; Najam, Rahila; Rizwani, Ghazala H; Abbas, Syed Atif

    2015-09-01

    This study depicts a profile of existence of heavy metals (Cu, Ni, Zn, Cd, Hg, Mn, Fe, Na, Ca, and Mg) in some important herbal plants like (H. Integrifolia, D. regia, R. communis, C. equisetifolia, N. oleander, T. populnea, M. elengi, H. schizopetalus, P. pterocarpum) from Pakistan and an antidiabetic Malaysian herbal drug product containing (Punica granatum L. (Mast) Hook, Momordica charantia L., Tamarindus indica L., Lawsonia inermis L.) using atomic absorption spectrophotometer. Heavy metals in these herbal plants and Malaysian product were in the range of 0.02-0.10 ppm of Cu, 0.00-0.02 ppm of Ni, 0.02-0.29 ppm of Zn, 0.00-0.04 ppm of Cd, 0.00-1.33 ppm of Hg, 0.00-0.54 ppm of Mn, 0.22-3.16 ppm of Fe, 0.00-9.17 ppm of Na, 3.27-15.63 ppm of Ca and 1.85-2.03 ppm of Mg. All the metals under study were within the prescribed limits except mercury. Out of 10 medicinal plants/product under study 07 were beyond the limit of mercury permissible limits. Purpose of this study is to determine heavy metals contents in selected herbal plants and Malaysian product, also to highlight the health concerns related to the presence of toxic levels of heavy metals.

  3. [Analysis and comparison of trace elements of herba euphorbiae humifusae in different periods by microwave digestion-atomic absorption spectroscopy].

    Science.gov (United States)

    Xiong, Wei; Cai, Miao-zhen; Wang, Hong; Yu, Rui-peng; Cheng, Cun-gui

    2010-07-01

    Herba euphorbiae humifusae is the dried whole plant of Euphorbia humi fusa Willd. that belongs to euphorbiaceae. In the present paper, the microwave digestion procedure was used to digest herba euphorbiae humifusae collected in different periods, and then flame atomic absorption spectrometry (FAAS) was used to determine the contents of eight kinds of trace elements of herba euphorbiae humifusae in different periods, and the change in the contents of trace elements at different times was studied and analysed. The results showed that of all the trace elements of herba euphorbiae humifusae in different periods, element Fe was the highest in June, element K was in August at the highest level, element Mn reached the highest content in September, elements Na and Ca were dividedly at the highest content in October and November, and in December the highest content elements were Zn, Cu and Mg. In one word, the change of Na and Ca was jumping, while the change of Cu and Zn was comparatively mild. The results provide scientific basis for the time of collection of herba euphorbiae humifusae.

  4. 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.

  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

    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.

  6. Selective determination of inorganic cobalt in nutritional supplements by ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Paula; Martinis, Estefania M. [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Martinez, Luis D. [INQUISAL-CONICET, Departamento de Quimica Analitica, Facultad de Quimica, Bioquimica y Farmacia, Universidad Nacional de San Luis, San Luis (Argentina); Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar [Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN-CCT-CONICET-Mendoza), Av. Ruiz Leal S/N Parque General San Martin, M 5502 IRA Mendoza (Argentina); Instituto de Ciencias Basicas, Universidad Nacional de Cuyo, Mendoza (Argentina)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer Synergy of ultrasound energy and TILDLME technique for improved metal extraction. Black-Right-Pointing-Pointer Highly selective determination of inorganic Co species at trace levels. Black-Right-Pointing-Pointer Speciation analysis of Co in several nutritional supplements with highly complex matrices. Black-Right-Pointing-Pointer Development of an environmentally friendly microextraction technique with minimal waste production and sample consumption. - Abstract: In the present work, a simple and rapid analytical method based on application of ionic liquids (ILs) for inorganic Co(II) species (iCo) microextraction in a variety of nutrient supplements was developed. Inorganic Co was initially chelated with 1-nitroso-2-naphtol (1N2N) reagent followed by a modern technique named ultrasound-assisted temperature-controlled ionic liquid dispersive liquid phase microextraction (USA-TILDLME). The extraction was performed with 1-hexyl-3-methylimidazolium hexafluorophosphate [C{sub 6}mim][PF{sub 6}] with the aid of ultrasound to improve iCo recovery. Finally, the iCo-enriched IL phase was solubilized in methanol and directly injected into an electrothermal atomic absorption spectrometer (ETAAS). Several parameters that could influence iCo microextraction and detection were carefully studied. Since the main difficulty in these samples is caused by high concentrations of potential interfering ions, different approaches were evaluated to eliminate interferences. The limit of detection (LOD) was 5.4 ng L{sup -1}, while the relative standard deviation (RSD) was 4.7% (at 0.5 {mu}g L{sup -1} Co level and n = 10), calculated from the peak height of absorbance signals. Selective microextraction of iCo species was achieved only by controlling the pH value during the procedure. The method was thus successfully applied for determination of iCo species in nutritional supplements.

  7. 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.

  8. 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.

  9. An analytical method for determination of mercury by cold vapor atomic absorption spectroscopy; Determinazione di mercurio. Metodo per spettrometria di assorbimento atomico a vapori freddi (CV-AAS)

    Energy Technology Data Exchange (ETDEWEB)

    Campanella, L. [Rome Univ. La Sapienza, Rome (Italy); Mastroianni, D.; Capri, S.; Pettine, M. [CNR, Rome (Italy). Ist. di Ricerca sulle Acque; Spezia, S.; Bettinelli, M. [ENEL, Unified Modelling Language, Piacenza (Italy)

    1999-09-01

    An analytical procedure for the determination of total mercury in wastewaters and natural waters is described. Aqueous samples are fast digested with nitric acid by using the microwave-oven technique; the analysis of mercury is then performed by cold vapor atomic absorption spectrometry (CV-AAS) using two possible instrumental apparatus (batch system or flow injection). Sodium borohydride is used as the reducing agent for mercury in solution (Method A). The use of amalgamation traps on gold for the preconcentration of mercury lowers the detection limit of the analyte (Method B). [Italian] Viene descritta una procedura analitica per la determinazione del mercurio totale in acque di scarico e naturali. Il campione acquoso viene sottoposto a mineralizzazione con acido nitrico in forno a microonde e analizzato mediante spettroscopia di assorbimento atomico a vapori freddi (CV-AAS) in due possibili configurazioni strumentali (sistema batch oppure flow injection), utilizzando sodio boro idruro come agente riducente del mercurio (metodo A). L'impiego della trappola di oro per la preconcentrazione del mercurio mediante amalgama consente di determinare l'analita a livelli di pochi ng/L (metodo B).

  10. Direct determination of arsenic and antimony in naphtha by electrothermal atomic absorption spectrometry with microemulsion sample introduction and iridium permanent modifier.

    Science.gov (United States)

    Cassella, Ricardo J; Barbosa, Bruno Alberto R S; Santelli, Ricardo E; Rangel, Alessandra T

    2004-05-01

    This paper reports the determination of arsenic and antimony in naphtha by employing electrothermal atomic absorption spectrometry (ETAAS) as the analytical technique. In order to promote the direct determination of the analytes in the very volatile naphtha, the formation of a microemulsion with different surfactants (Triton X-100 and Brij-35) and different chemical modification strategies were tested. The results indicated that Triton X-100 is the best emulsification agent for naphtha in both As and Sb determination when it is employed at a concentration of 1% w/v in the microemulsion. Under these conditions, the microemulsion was stabile for at least 2 h. By using Brij-35 it was possible to achieve good stability only in the first 15 min. Among all chemical modification approaches investigated (Ir permanent modifier, W-Ir permanent modifier, and Pd modifier), the Ir permanent modifier provided better sensitivity for both analytes and allowed a higher pyrolysis temperature, which decreased the background signals at lower levels. Under the best conditions established in this work, an RSD of 4.6% (20 microg L(-1)) and a detection limit of 2.7 microg L(-1) were observed for arsenic. For antimony, an RSD of 4.0% (20 microg L(-1)) and a detection limit of 2.5 microg L(-1) were obtained. The accuracy of the procedure was assessed by analyzing spiked samples of naphtha from different origins.

  11. Preconcentration of thallium (I) by single drop microextraction with electrothermal atomic absorption spectroscopy detection using dicyclohexano-18-crown-6 as extractant system.

    Science.gov (United States)

    Chamsaz, Mahmoud; Arbab-Zavar, Mohammad Hossien; Darroudi, Abolfazl; Salehi, Thiery

    2009-08-15

    A simple single drop liquid-phase microextraction (SDME) technique, combined with electrothermal atomic absorption spectroscopy (ETAAS) is developed both to preconcentrate and determine thallium (I) ions in aqueous solutions. The ions were transferred from 10.0 ml of aqueous sample (donor phase) containing 0.5 ml of 1% picric acid as the ion-pair agent into a 3 microl microdrop of nitrobenzene (acceptor phase) containing dicyclohexano-18-crown-6 as the complexing agent. The latter will help to improve the extraction efficiency of the analyte. After the ions have been extracted, the acceptor drop was directly injected into a graphite furnace for thallium (I) determination. Several parameters such as the extracting solvent, extraction time, temperature, concentration of picric acid and crown ether, drop volume and stirring rate were examined. Under the optimized experimental conditions, the detection limit (L.O.D.) was 0.7 ng ml(-1). The relative standard deviation for five replicate analysis of 10 ng ml(-1) of thallium (I) was 5.1%. The calibration curve was linear in the range of 3-22 ng ml(-1). The results for determination of thallium in reference material, spiked tap water and seawater demonstrated the accuracy, recovery and applicability of the presented method. The enrichment factor was 50.

  12. Simultaneous speciation and preconcentration of ultra traces of inorganic tellurium and selenium in environmental samples by hollow fiber liquid phase microextraction prior to electrothermal atomic absorption spectroscopy determination.

    Science.gov (United States)

    Ghasemi, Ensieh; Najafi, Nahid Mashkouri; Raofie, Farhad; Ghassempour, Alireza

    2010-09-15

    A simple and effective speciation and preconcentration method based on hollow fiber liquid phase microextraction (HF-LPME) was developed for simultaneous separation of trace inorganic tellurium and selenium in environmental samples prior to electrothermal atomic absorption spectroscopy (ETAAS) determination. The method involves the selective extraction of the Te (IV) and Se (IV) species by HF-LPME with the use of ammonium pyrrolidinecarbodithioate (APDC) as the chelating agent. The complex compounds were extracted into 10 microL of toluene and the solutions were injected into a graphite furnace for the determination of Te (IV) and Se (IV). To determine the total tellurium and selenium in the samples, first Te (VI) and Se (VI) were reduced to Te (IV) and Se (IV), and then the microextraction method was performed. The experimental parameters of HF-LPME were optimized using a central composite design after a 2(n-1) fractional factorial experimental design. Under optimum conditions, enrichment factors of up to 520 and 480 were achieved for Te (IV) and Se (IV), respectively. The detection limits were 4 ng L(-1) with 3.5% RSD (n=5, c=2.0 microg L(-1)) for Te (IV) and 5 ng L(-1) with 3.1% RSD for Se (IV). The applicability of the developed technique was evaluated by application to spiked, environmental water and soil samples. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Vapor generation – atomic spectrometric techniques. Expanding frontiers through specific-species preconcentration. A review

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Martinez, Luis D., E-mail: ldm@unsl.edu.ar [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina)

    2015-05-22

    This article reviews 120 articles found in SCOPUS and specific Journal cites corresponding to the terms ‘preconcentration’; ‘speciation’; ‘vapor generation techniques’ and ‘atomic spectrometry techniques’ in the last 5 years. - Highlights: • Recent advances in vapor generation and atomic spectrometry were reviewed. • Species-specific preconcentration strategies after and before VG were discussed. • New preconcentration and speciation analysis were evaluated within this framework. - Abstract: We review recent progress in preconcentration strategies associated to vapor generation techniques coupled to atomic spectrometric (VGT-AS) for specific chemical species detection. This discussion focuses on the central role of different preconcentration approaches, both before and after VG process. The former was based on the classical solid phase and liquid–liquid extraction procedures which, aided by automation and miniaturization strategies, have strengthened the role of VGT-AS in several research fields including environmental, clinical, and others. We then examine some of the new vapor trapping strategies (atom-trapping, hydride trapping, cryotrapping) that entail improvements in selectivity through interference elimination, but also they allow reaching ultra-low detection limits for a large number of chemical species generated in conventional VG systems, including complete separation of several species of the same element. This review covers more than 100 bibliographic references from 2009 up to date, found in SCOPUS database and in individual searches in specific journals. We finally conclude by giving some outlook on future directions of this field.

  14. Elucidation of the effects of a high fat diet on trace elements in rabbit tissues using atomic absorption spectroscopy.

    Science.gov (United States)

    Abdelhalim, Mohamed Anwar K; Alhadlaq, Hisham A; Moussa, Sherif Abdelmottaleb

    2010-01-12

    The mechanism of atherogenesis is not yet fully understood despite intense study in this area. The effects of high fat diet (HFD) on the changes of trace elements [iron (Fe), copper (Cu) and zinc (Zn)] in several tissues of rabbits have not been documented before. Thus, the aim of this study was to elucidate the changes in trace elements in several tissues of rabbits fed on HFD for a period of feeding of 10 weeks. The HFD group was fed a NOR rabbit chow supplemented with 1.0% cholesterol plus 1.0% olive oil. Fe, Cu and Zn concentrations were measured in four types of tissue from control and HFD rabbits using atomic absorption spectroscopy (AAS). Comparing HFD rabbits to control rabbits, we found that the highest percentage change of increase of Fe was 95% in lung tissue, while the lowest percentage change of increase of Fe was 7% in kidney tissue; the highest percentage change of decrease of Cu was 16% in aortic tissue, while the lowest percentage change of decrease of Cu was 6% in kidney tissue; and the highest percentage change of decrease of Zn was 71% in kidney tissue, while the lowest percentage change of decrease of Zn was 8% in lung tissue. These results suggest that Fe plays a major role in atherogenesis; it may accelerate the process of atherosclerosis probably through the production of free radicals, deposition and absorption of intracellular and extracellular lipids in the intima, connective tissue formation, smooth muscle proliferation, lower matrix degradation capacity and increased plaque stability. Furthermore, inducing anemia in HFD rabbits may delay or inhibit the progression of atherosclerosis. Cu plays a minor role in atherogenesis and Cu supplements may inhibit the progression of atherogenesis, perhaps by reducing the migration of smooth muscle cells from the media to the intima. Zn plays a major role in atherogenesis and that it may act as an endogenous protective factor against atherosclerosis perhaps by reducing lesion Fe content

  15. Advantages of the iridium permanent modifier in fast programs applied to trace-element analysis of plant samples by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vassileva, E.; Baeten, H.; Hoenig, M. [Centre for Veterinary and Agrochemical Research (CERVA), Tervuren (Belgium)

    2001-03-01

    The application of a fast program combined with the advantages of the iridium permanent modifier is proposed for trace element analysis of plant samples by electrothermal atomic absorption spectrometry (ETAAS). For two volatile elements (Cd, Pb) and two mid-refractory elements (Cr, Ni) it was demonstrated that coating of the platform or of the tube atomization area with Ir is an efficient means of improving the accuracy and precision of results. A detailed study of interference from individual main matrix components and from composite plant matrices has confirmed the usefulness of the whole approach. The validity of the method has been confirmed by analysis of eight reference plant materials. (orig.)

  16. Shapes of the $^{192,190}$Pb ground states from beta decay studies using the total absorption technique

    CERN Document Server

    Estevez Aguado, M.E.; Agramunt, J.; Rubio, B.; Tain, J.L.; Jordan, D.; Fraile, L.M.; Gelletly, W.; Frank, A.; Csatlos, M.; Csige, L.; Dombradi, Zs.; Krasznahorkay, A.; Nacher, E.; Sarriguren, P.; Borge, M.J.G.; Briz, J.A.; Tengblad, O.; Molina, F.; Moreno, O.; Kowalska, M.; Fedosseev, V.N.; Marsh, B.A.; Fedorov, D.V.; Molkanov, P.L.; Andreyev, A.N.; Seliverstov, M.D.; Burkard, K.; Huller, W.

    2015-01-01

    The beta decay of $^{192,190}$Pb has been studied using the total absorption technique at the ISOLDE(CERN) facility. The beta-decay strength deduced from the measurements, combined with QRPA theoretical calculations, allow us to infer that the ground states of the $^{192,190}$Pb isotopes are spherical. These results represent the first application of the shape determination method using the total absorption technique for heavy nuclei and in a region where there is considerable interest in nuclear shapes and shape effects.

  17. A new supramolecular based liquid solid microextraction method for preconcentration and determination of trace bismuth in human blood serum and hair samples by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Kahe, Hadi; Chamsaz, Mahmoud

    2016-11-01

    A simple and reliable supramolecule-aggregated liquid solid microextraction method is described for preconcentration and determination of trace amounts of bismuth in water as well as human blood serum and hair samples. Catanionic microstructures of cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) surfactants, dissolved in deionized water/propanol, are used as a green solvent to extract bismuth (III)-diethyldithiocarbamate complexes by dispersive microextraction methodology. The extracted solid phase is easily removed and dissolved in 50 μL propanol for subsequent measurement by electrothermal atomic absorption spectrometry (ET-AAS). The procedure benefits the merits of supramolecule aggregates' properties and dispersive microextraction technique using water as the main component of disperser solvent, leading to direct interaction with analyte. Phase separation behavior of extraction solvent and different parameters influencing the extraction efficiency of bismuth ion such as salt concentration, pH, centrifugation time, amount of chelating agent, SDS:CTAB mole ratio, and solvent amounts were thoroughly optimized. Under the optimal experimental conditions, the calibration curve was linear in the range of 0.3-6 μg L-1 Bi (III) with a limit of detection (LOD) of 0.16 μg L-1 (S/N = 3). The relative standard deviations (RSD) of determination were obtained to be 5.1 and 6.2 % for 1 and 3 μg L-1 of Bi (III), respectively. The developed method was successfully applied as a sensitive and accurate technique for determination of bismuth ion in human blood serum, hair samples, and a certified reference material.

  18. Colloidal mercury (Hg) distribution in soil samples by sedimentation field-flow fractionation coupled to mercury cold vapour generation atomic absorption spectroscopy.

    Science.gov (United States)

    Santoro, A; Terzano, R; Medici, L; Beciani, M; Pagnoni, A; Blo, G

    2012-01-01

    Diverse analytical techniques are available to determine the particle size distribution of potentially toxic elements in matrices of environmental interest such as soil, sediments, freshwater and groundwater. However, a single technique is often not exhaustive enough to determine both particle size distribution and element concentration. In the present work, the investigation of mercury in soil samples collected from a polluted industrial site was performed by using a new analytical approach which makes use of sedimentation field-flow fractionation (SdFFF) coupled to cold vapour generation electrothermal atomic absorption spectroscopy (CV-ETAAS). The Hg concentration in the SdFFF fractions revealed a broad distribution from about 0.1 to 1 μm, roughly following the particle size distributions, presenting a maximum at about 400-700 nm in diameter. A correlation between the concentration of Hg in the colloidal fraction and organic matter (O.M.) content in the soil samples was also found. However, this correlation is less likely to be related to Hg sorption to soil O.M. but rather to the presence of colloidal mercuric sulfide particles whose size is probably controlled by the occurrence of dissolved O.M. The presence of O.M. could have prevented the aggregation of smaller particles, leading to an accumulation of mercuric sulfides in the colloidal fraction. In this respect, particle size distribution of soil samples can help to understand the role played by colloidal particles in mobilising mercury (also as insoluble compounds) and provide a significant contribution in determining the environmental impact of this toxic element.

  19. [Determination of trace gold by flame atomic absorption spectrometry after separation and preconcentration with load nanometer titanium dioxide].

    Science.gov (United States)

    Liu, Zheng-Hua; Zhou, Fang-Qin; Jiang, Fang-Ming; Huang, Rong-Hui; Yang, Liu; Zhou, Le-Zhou

    2008-02-01

    A new method for the determination of trace gold by flame atomic absorption spectrometry (FAAS) after preconcentration with p-dimethylaminobenzylidenerhodanine (DMABR) loaded with nanometer TiO2 was developed. The method is convenient, highly precise and linear in a wide range. Under dynamic condition, the optimum pH of solution, flow rate, elution conditions were obtained for preconcentration of trace gold. And the effect of interfering ions was also investigated. It was found that the studied gold could be quantitatively preconcentrated on loaded nanometer TiO2 at pH = 3.5, and the flow rate of sample solution was 0.6 mL x min(-1), and the flow rate of eluting solution with 0.1 mol x L(-1) HCl-0.5 mol x L(-1) thiourea was 0.5 mL x min(-1), sufficient for complete elution. The dynamic adsorption capacity of gold on load nanometer TiO2 was 23.19 mg x g(-1). The linear range for gold was 0-0.40 microg x mL(-1), correlation coefficient was 0. 999 3, detection limit (3sigma, n = 11) for gold was 2.34 ng x mL(-1), and the relative standard deviation was 2.9% (n = 6, c = 0.10 microg x mL(-1)), the recovery was in the range of 96.7%-101.7%. The method has been applied to the determination of trace gold in water samples with satisfactory results.

  20. Feasibility of using direct determination of cadmium and lead in fresh meat by electrothermal atomic absorption spectrometry for screening purposes

    Energy Technology Data Exchange (ETDEWEB)

    Damin, Isabel C.F. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil); Silva, Marcia M. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil)], E-mail: mmsilva@iq.ufrgs.br; Vale, Maria Goreti R. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre - RS (Brazil); Welz, Bernhard [Instituto de Quimica, Universidade Federal da Bahia, 40170-290 Salvador - BA (Brazil)

    2007-09-15

    A method for the direct determination of cadmium and lead in fresh meat for screening purposes is proposed using electrothermal atomic absorption spectrometry. The fresh meat samples were homogenized, weighed directly onto solid sampling platforms and introduced into a transversely heated solid sampling graphite tube. The main challenges associated with this procedure, such as weighing errors and optimization of the temperature program were investigated in detail. Calibration was performed against aqueous standards and two modifiers were investigated: 0.05% Pd + 0.03% Mg + 0.05% Triton X-100 and 0.01% Pd + 10% NH{sub 4}NO{sub 3} + 0.05% Triton X-100. The former one is recommended due to the higher pyrolysis temperature obtained for cadmium and the better limits of detection of 1.9 {mu}g kg{sup -} {sup 1} for lead and 0.13 {mu}g kg{sup -} {sup 1} for cadmium, based on 10 mg of sample mass. The results obtained for cadmium and lead in two certified reference materials were statistically not different from the certified values on a 95% confidence level, indicating that calibration against aqueous standards is suitable for this application. In order to evaluate weighing errors the fresh samples were dried (at 60 deg. C) to constant weight; the results obtained with fresh and dried samples were in agreement, taking the loss of weight into consideration for the latter ones. The average relative standard deviation of 14% is in concordance with the results of others using fresh meat. Comparison with the digestion method adopted by the Brazilian Ministry of Agriculture shows no significant differences between the results at the 95% confidence level. This study shows that direct analysis of fresh meet can be applied as a rapid routine screening procedure for residue control in products of animal origin, helping the implementation and maintenance of sanitary control.

  1. Study on the Interference of Iron, Aluminium and Silicon on the Atomic Absorption Spectrometric Determination of Mangan in Laterite Mineral

    Directory of Open Access Journals (Sweden)

    Sulistyo Saputro

    2010-06-01

    Full Text Available Interference of iron, aluminum and silicon on the determination of mangan in laterite mineral by atomic absorption spectrometry has been investigated. Dissolution of laterite mineral into solution have been carried out by wet method destruction using combination of 7 mL of aquaregia, 7.5 mL of concentrated perchloric acid and 9 mL of fluoride acid 48% In sealed teflon flask heated at temperature of about 110 °C for 3 hours to determine the content of Mn element in laterite mineral directly. Interference of these three metals were carried out by evaluating the differences of Mn absorbance at wavelength 279.50 nm and slit width 0.2 nm between the solutions containing mangan only and those containing the some amount of mangan together with the interfering elements at those concentration range in laterite mineral. The result showed that both iron at concentration of 100 ppm until 500 ppm and aluminum at concentration at 3 ppm until 15 ppm caused significant and non-linear interference on the determination of Mn 2 ppm. Interference of iron was effectively eliminated by releasing action of aluminum. The signal depression reductional decrease due to 234 ppm of silicon on the determination of Mn 2 ppm can be eliminated by adding 2.30 mL of CaCl2 0.2% (m/v into these solution. The content of Mn in the laterite mineral after and before adding of CaCl2 into solution were 2407.04 ± 59.26 μg g-1 and 2311.76 ± 23.61 μg g-1, respectively. This result was significantly different at confidence level 95% as shown by the value of tcalculated=4.91 that was higher than ttable=4.30.

  2. Selective cloud point extraction and graphite furnace atomic absorption spectrometric determination of molybdenum (VI) ion in seawater samples

    Energy Technology Data Exchange (ETDEWEB)

    Filik, Hayati, E-mail: filik@istanbul.edu.tr [Istanbul University, Faculty of Engineering, Department of Chemistry, Avcilar, 34320 Istanbul (Turkey); Cengel, Tayfun; Apak, Resat [Istanbul University, Faculty of Engineering, Department of Chemistry, Avcilar, 34320 Istanbul (Turkey)

    2009-09-30

    A cloud point extraction process using the nonionic surfactant Triton X-114 to extract molybdenum from aqueous solutions was investigated. The method is based on the complexation reaction of Mo(VI) with 1,2,5,8-tetrahydroxyanthracene-9,10-dione (quinalizarine: QA) and micelle-mediated extraction of the complex. The enriched analyte in the surfactant-rich phase was determined by graphite furnace atomic absorption spectrometry (GFAAS). The optimal extraction and reaction conditions (e.g. pH, reagent and surfactant concentrations, temperature, incubation and centrifugation times) were evaluated and optimized. Under the optimized experimental conditions, the limit of detection (LOD) for Mo(VI) was 7.0 ng L{sup -1} with an preconcentration factor of {approx}25 when 10 mL of sample solution was preconcentrated to 0.4 mL. The proposed method (with extraction) showed linear calibration within the range 0.03-0.6 {mu}g L{sup -1}. The relative standard deviation (RSD) was found to be 3.7% (C{sub Mo(VI)} = 0.05 {mu}g L{sup -1}, n = 5) for pure standard solutions, whereas RSD for the recoveries from real samples ranged between 2 and 8% (mean RSD = 3.9%). The method was applied to the determination of Mo(VI) in seawater and tap water samples with a recovery for the spiked samples in the range of 98-103%. The interference effect of some cations and anions was also studied. In the presence of foreign ions, no significant interference was observed. In order to verify the accuracy of the method, a certified reference water sample was analysed and the results obtained were in good agreement with the certified values.

  3. Sample preparation for arsenic speciation analysis in baby food by generation of substituted arsines with atomic absorption spectrometry detection.

    Science.gov (United States)

    Huber, Charles S; Vale, Maria Goreti R; Dessuy, Morgana B; Svoboda, Milan; Musil, Stanislav; Dědina, Jiři

    2017-12-01

    A slurry sampling procedure for arsenic speciation analysis in baby food by arsane generation, cryogenic trapping and detection with atomic absorption spectrometry is presented. Several procedures were tested for slurry preparation, including different reagents (HNO3, HCl and tetramethylammonium hydroxide - TMAH) and their concentrations, water bath heating and ultrasound-assisted agitation. The best results for inorganic arsenic (iAs) and dimethylarsinate (DMA) were reached when using 3molL-1 HCl under heating and ultrasound-assisted agitation. The developed method was applied for the analysis of five porridge powder and six baby meal samples. The trueness of the method was checked with a certified reference material (CRM) of total arsenic (tAs), iAs and DMA in rice (ERM-BC211). Arsenic recoveries (mass balance) for all samples and CRM were performed by the determination of the tAs by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion and its comparison against the sum of the results from the speciation analysis. The relative limits of detection were 0.44, 0.24 and 0.16µgkg-1 for iAs, methylarsonate and DMA, respectively. The concentrations of the most toxic arsenic species (iAs) in the analyzed baby food samples ranged between 4.2 and 99µgkg-1 which were below the limits of 300, 200 and 100µgkg-1 set by the Brazilian, Chinese and European legislation, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Quantifying uncertainty in the measurement of arsenic in suspended particulate matter by Atomic Absorption Spectrometry with hydride generator

    Directory of Open Access Journals (Sweden)

    Ahuja Tarushee

    2011-04-01

    Full Text Available Abstract Arsenic is the toxic element, which creates several problems in human being specially when inhaled through air. So the accurate and precise measurement of arsenic in suspended particulate matter (SPM is of prime importance as it gives information about the level of toxicity in the environment, and preventive measures could be taken in the effective areas. Quality assurance is equally important in the measurement of arsenic in SPM samples before making any decision. The quality and reliability of the data of such volatile elements depends upon the measurement of uncertainty of each step involved from sampling to analysis. The analytical results quantifying uncertainty gives a measure of the confidence level of the concerned laboratory. So the main objective of this study was to determine arsenic content in SPM samples with uncertainty budget and to find out various potential sources of uncertainty, which affects the results. Keeping these facts, we have selected seven diverse sites of Delhi (National Capital of India for quantification of arsenic content in SPM samples with uncertainty budget following sampling by HVS to analysis by Atomic Absorption Spectrometer-Hydride Generator (AAS-HG. In the measurement of arsenic in SPM samples so many steps are involved from sampling to final result and we have considered various potential sources of uncertainties. The calculation of uncertainty is based on ISO/IEC17025: 2005 document and EURACHEM guideline. It has been found that the final results mostly depend on the uncertainty in measurement mainly due to repeatability, final volume prepared for analysis, weighing balance and sampling by HVS. After the analysis of data of seven diverse sites of Delhi, it has been concluded that during the period from 31st Jan. 2008 to 7th Feb. 2008 the arsenic concentration varies from 1.44 ± 0.25 to 5.58 ± 0.55 ng/m3 with 95% confidence level (k = 2.

  5. Determination of inorganic and total mercury by vapor generation atomic absorption spectrometry using different temperatures of the measurement cell

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, Luiz Eduardo [Universidade Federal de Santa Maria, Departamento de Quimica, Campus de Camobi, 97105900 Santa Maria, RS (Brazil); Goldschmidt, Fabiane [Universidade Federal de Santa Maria, Departamento de Quimica, Campus de Camobi, 97105900 Santa Maria, RS (Brazil); Paniz, Jose Neri Gottfried [Universidade Federal de Santa Maria, Departamento de Quimica, Campus de Camobi, 97105900 Santa Maria, RS (Brazil); Moraes Flores, Erico Marlon de [Universidade Federal de Santa Maria, Departamento de Quimica, Campus de Camobi, 97105900 Santa Maria, RS (Brazil); Dressler, Valderi Luiz [Universidade Federal de Santa Maria, Departamento de Quimica, Campus de Camobi, 97105900 Santa Maria, RS (Brazil)]. E-mail: valdres@quimica.ufsm.br

    2005-06-30

    A simple and inexpensive laboratory-built flow injection vapor generation system coupled to atomic absorption spectrometry (FI-VG AAS) for inorganic and total mercury determination has been developed. It is based on the vapor generation of total mercury and a selective detection of Hg{sup 2+} or total mercury by varying the temperature of the measurement cell. Only the inorganic mercury is measured when the quartz cell is at room temperature, and when the cell is heated to 650 deg. C or higher the total Hg concentration is measured. The organic Hg concentration in the sample is calculated from the difference between the total Hg and Hg{sup 2+} concentrations. Parameters such as the type of acid (HCl or HNO{sub 3}) and its concentration, reductant (NaBH{sub 4}) concentration, carrier solution (HCl) flow rate, carrier gas flow rate, sample volume and quartz cell temperature, which influence FI-VG AAS system performance, were systematically investigated. The optimized conditions for Hg{sup 2+} and total Hg determinations were: 1.0 mol l{sup -1} HCl as carrier solution, carrier flow rate of 3.5 ml min{sup -1}, 0.1% (m/v) NaBH{sub 4}, reductant flow rate of 1.0 ml min{sup -1} and carrier gas flow rate of 200 ml min{sup -1}. The relative standard deviation (RSD) is lower than 5.0% for a 1.0 {mu}g l{sup -1} Hg solution and the limit of quantification (LOQ, 10 s) is 55 ng g{sup -1}. Certified samples of dogfish muscle (DORM-1 and DORM-2) and non-certified fish samples were analyzed, using a 6.0 mol l{sup -1} HCl solution for analyte extraction. The Hg{sup 2+} and CH{sub 3}Hg{sup +} concentrations found were in agreement with certified ones.

  6. Coacervative extraction of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hagarová, Ingrid, E-mail: hagarova@fns.uniba.sk; Bujdoš, Marek; Matúš, Peter; Kubová, Jana

    2013-10-01

    In this work, a relatively simple and sensitive method for separation/preconcentration of trace lead from natural waters prior to its determination by electrothermal atomic absorption spectrometry has been proposed. The method is based on the extraction of Pb–dithizone chelate with coacervates made up of lauric acid in the presence of potassium ions and methanol. Several important factors affecting extraction efficiency such as pH, concentration of lauric acid and dithizone, ionic strength, incubation and centrifugation time were investigated and optimized. After separation of aqueous bulk solution from surfactant-rich phase, the final extract was redissolved by using 500 μl of methanol acidified with 0.2 mol l{sup −1} HNO{sub 3}. Under the optimized conditions (using initial sample volume of 10 ml), enrichment factor of 17.0, detection limit of 0.12 μg l{sup −1}, quantification limit of 0.38 μg l{sup −1}, relative standard deviation of 4.2% (for 2 μg l{sup −1} of Pb; n = 26), linearity of the calibration graph in the range of 0.5–4.0 μg l{sup −1} (with correlation coefficient better than 0.995) were achieved. The method was validated by the analysis of certified reference material (TMDA-61). Extraction recoveries for the CRM, spiked model solutions and spiked natural water samples were in the range of 91–96%. Finally, the method was applied to the separation/preconcentration and determination of trace lead in natural waters. - Highlights: • The potential of coacervates for the extraction of metal ions is examined. • No difficulties in coupling of ETAAS with the proposed CAE are observed. • Achieved preconcentration factor results in enhanced sensitivity. • Analytical performance is confirmed by the reliable determination of trace Pb. • The proposed CAE is ecofriendly and efficient.

  7. Cloud Point Extraction and Flame Atomic Absorption Spectrometric Determination of Lead, Cadmium and Palladium in Some Food and Biological Samples

    Directory of Open Access Journals (Sweden)

    M. Soylak

    2011-12-01

    Full Text Available The proposed method is based on the complexation of the Pb2+, Cd2+ and Pd2+ ions with 3-(1-(1-H-Indol-3-Yl-3-phenylallyl-1H-indole (IPAI at pH 8.0 in the presence of Triton X-114. The phase separation occured when micellar solution was heated at 55 ◦C. The surfactant-rich phase, diluted to 0.5 mL via 1.0 mol L−1 nitric acid in methanol was directly introduced into the nebulizer of the flame atomic absorption spectrometry (FAAS. Influence of variables such as pH, amount of ligand and Triton X-114, heating time and temperature were evaluated and optimized. The optimized enhancement factors for Pb2+, Cd2+ and Pd2+ ions were 22, 33 and 23, respectively and the detection limit (DLs was between of 1.6–2.6 µgL−1. The relative standard deviation (RSD of each ion was found to be less than 4.6% at 100 µgL−1. In addition, the calibration graphs were linear in the range of 0.01-0.22 μg mL−1 for Cd2+ ion, 0.018-0.26 μg mL−1 for Pb2+ ion and 0.02-0.27 μg mL−1 for Pd2+ ion with the correlation coefficients in the range of 0.995–0.999.

  8. Evaluation of lithium determination in three analyzers: flame emission, flame atomic absorption spectroscopy and ion selective electrode.

    Science.gov (United States)

    Aliasgharpour, Mehri; Hagani, Hamid

    2009-10-01

    Lithium carbonate salt has become an increasingly important substance in the treatment of manic depressive disorders, and its relatively narrow therapeutic range has caused laboratories to monitor the serum concentration carefully. In the present work we evaluated lithium measurement in 3 different analyzers. METHODS #ENTITYSTARTX00026; Three different analyzers including Flame Emission (FES), Flame Atomic Absorption Spectroscopy (FAAS), and Ion Selective Electrode (ISE) were used. All chemicals had a grade suitable for trace metal analysis. Within-day precision of CV was ≤ 1.5% for FES & FAAS, except for ISE (1.9% CV). Between-days precision of CV was less for FES than for FAAS and ISE (1.3% versus 2.2% & 2.3%). The percent recovery of added lithium in pooled patients' serum was higher for ISE than for FASS and FES (103.4% versus 96.2% and 94.6%). We also obtained a higher average lithium concentration for patients' serum samples (n=16) measured by ISE than for FAAS and FES (0.825±0.30 versus 0.704±0.26 & 0.735±0.19). Paired t-test results revealed a significant difference (p< 0.001) for patient sera analyzed with FAAS and ISE. We report higher results for ISE than the other two analyzers and conclude that the choice between the two flame methods for patients' serum lithium determination is arbitrary and that FES analyzer is a more attractive routine alternative for lithium determination than FAAS because of its cost and ease of performance. In addition, the results obtained by ISE are precise. However, its accuracy may depend on other interfering factors.

  9. Determination of selected elements in whole coal and in coal ash from the eight argonne premium coal samples by atomic absorption spectrometry, atomic emission spectrometry, and ion-selective electrode

    Science.gov (United States)

    Doughten, M.W.; Gillison, J.R.

    1990-01-01

    Methods for the determination of 24 elements in whole coal and coal ash by inductively coupled argon plasma-atomic emission spectrometry, flame, graphite furnace, and cold vapor atomic absorption spectrometry, and by ion-selective electrode are described. Coal ashes were analyzed in triplicate to determine the precision of the methods. Results of the analyses of NBS Standard Reference Materials 1633, 1633a, 1632a, and 1635 are reported. Accuracy of the methods is determined by comparison of the analysis of standard reference materials to their certified values as well as other values in the literature.

  10. Dynamic light scattering and atomic force microscopy techniques for size determination of polyurethane nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Giehl Zanetti-Ramos, Betina [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil)], E-mail: betinagzramos@pq.cnpq.br; Beddin Fritzen-Garcia, Mauricia [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil); Schweitzer de Oliveira, Cristian; Avelino Pasa, Andre [Laboratorio de Filmes Finos e Superficie, Departamento de Fisica (Brazil); Soldi, Valdir [Grupo de Estudos em Materiais Polimericos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Borsali, Redouane [Centre de Recherche sur les Macromolecules Vegetales CERMAV/CNRS, 38041 - Grenoble (France); Creczynski-Pasa, Tania Beatriz [Laboratorio de Bioenergetica e Bioquimica de Macromoleculas, Departamento de Ciencias Farmaceuticas (Brazil)

    2009-03-01

    Nanoparticles have applications in various industrial fields principally in drug delivery. Nowadays, there are several processes for manufacturing colloidal polymeric systems and methods of preparation as well as of characterization. In this work, Dynamic Light Scattering and Atomic Force Microscopy techniques were used to characterize polyurethane nanoparticles. The nanoparticles were prepared by miniemulsion technique. The lipophilic monomers, isophorone diisocyanate (IPDI) and natural triol, were emulsified in water containing surfactant. In some formulations the poly(ethylene glycol) was used as co-monomer to obtain the hydrophilic and pegylated nanoparticles. Polyurethane nanoparticles observed by atomic force microscopy (AFM) were spherical with diameter around 209 nm for nanoparticles prepared without PEG. From AFM imaging two populations of nanoparticles were observed in the formulation prepared with PEG (218 and 127 nm) while dynamic light scattering (DLS) measurements showed a monodisperse size distribution around 250 nm of diameters for both formulations. The polydispersity index of the formulations and the experimental procedures could influence the particle size determination with these techniques.

  11. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of antimony by automated-hydride atomic absorption spectrophotometry

    Science.gov (United States)

    Brown, G.E.; McLain, B.J.

    1994-01-01

    The analysis of natural-water samples for antimony by automated-hydride atomic absorption spectrophotometry is described. Samples are prepared for analysis by addition of potassium and hydrochloric acid followed by an autoclave digestion. After the digestion, potassium iodide and sodium borohydride are added automatically. Antimony hydride (stibine) gas is generated, then swept into a heated quartz cell for determination of antimony by atomic absorption spectrophotometry. Precision and accuracy data are presented. Results obtained on standard reference water samples agree with means established by interlaboratory studies. Spike recoveries for actual samples range from 90 to 114 percent. Replicate analyses of water samples of varying matrices give relative standard deviations from 3 to 10 percent.

  12. Speciation of arsenic in baby foods and the raw fish ingredients using liquid chromatography-hydride generation-atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vinas, P.; Lopez-Garcia, I.; Merino-Merono, B.; Campillo, N.; Hernandez-Cordoba, M. [Murcia Univ. (Spain). Dept. of Analytical Chemistry

    2003-07-01

    The speciation of arsenic in different baby foods and the raw fish ingredients using the direct hybridisation of liquid chromatography (LC) and hydride generation atomic absorption spectrometry (HGAAS) is described. Good resolution of the species, arsenic(III), dimethylarsinic acid (DMAA), monomethylarsenic acid (MMAA) and arsenic(V) is achieved using an anion-exchange column with potassium phosphate as the mobile phase and gradient elution. Arsenobetaine (AsB) is determined by on-line oxidation using peroxydisulphate and hydride generation. The arsenicals were extracted by an enzymatic digestion procedure based on the action of trypsin or pancreatin. Arsenobetaine was the only arsenic species detected. The reliability of the procedure was checked by analyzing the total arsenic content of the samples by electrothermal atomic absorption spectrometry with microwave-oven digestion and by analyzing a certified reference material. The arsenic content in the baby foods comes from the raw fish ingredients and is highest when plaice is used. (orig.)

  13. Determination of gold, indium, tellurium and thallium in the same sample digest of geological materials by atomic-absorption spectroscopy and two-step solvent extraction

    Science.gov (United States)

    Hubert, A.E.; Chao, T.T.

    1985-01-01

    A rock, soil, or stream-sediment sample is decomposed with hydrofluoric acid, aqua regia, and hydrobromic acid-bromine solution. Gold, thallium, indium and tellurium are separated and concentrated from the sample digest by a two-step MIBK extraction at two concentrations of hydrobromic add. Gold and thallium are first extracted from 0.1M hydrobromic acid medium, then indium and tellurium are extracted from 3M hydrobromic acid in the presence of ascorbic acid to eliminate iron interference. The elements are then determined by flame atomic-absorption spectrophotometry. The two-step solvent extraction can also be used in conjunction with electrothermal atomic-absorption methods to lower the detection limits for all four metals in geological materials. ?? 1985.

  14. Use of factorial design and Doehlert matrix for multivariate optimisation of an on-line preconcentration system for lead determination by flame atomic absorption spectrometry

    OpenAIRE

    Ferreira, Sergio Luis Costa; Santos, W. N. L. dos; Bezerra, Marcos de Almeida; Lemos, Valfredo Azevedo; Bosque-Sendra, Juan M.

    2003-01-01

    Texto Completo: acesso restrito. p. 443–449. A system for on-line preconcentration and determination of lead by flame atomic absorption spectrometry (FAAS) was proposed. It was based on the sorption of lead(II) ions on a minicolumn of polyurethane foam loaded with 2-(2-thiazolylazo)-5 dimethylaminophenol (TAM). The optimisation step was carried out using twolevel full factorial and Doehlert designs for the determination of the optimum conditions for lead preconcentration. The proposed p...

  15. Determination of trace amounts of copper in river and sea water samples by flame atomic absorption spectrometry (FAAS) after cloud-point preconcentration

    OpenAIRE

    Goudarzi,Nasser

    2007-01-01

    A new preconcentration method was proposed using the cloud point approach for copper determination. The reagent 1,5-diphenyl-benzoin (Cupron) was used as a complexing agent and Triton X-114 was added as a surfactant. After phase separation, dilution of the surfactant-rich phase was carried out using acidified methanol and the copper content was subsequently measured by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, the enrichment factor...

  16. Absorption spectroscopy of heavy alkaline earth metals Ba and Sr in rare gas matrices--CCSD(T) calculations and atomic site occupancies.

    Science.gov (United States)

    Davis, Barry M; McCaffrey, John G

    2016-01-28

    Isolation of the heavier alkaline earth metals Ba and Sr in the solid rare gases (RGs) Ar, Kr, and Xe is analysed with absorption spectroscopy and interpreted partly with the assistance of ab initio calculations of the diatomic M ⋅ RG ground state interaction potentials. The y(1)P ← a(1)S resonance transitions in the visible spectral region are used to compare the isolation conditions of these two metal atom systems and calcium. Complex absorption bands were recorded in all three metal atom systems even after extensive sample annealing. Coupled cluster calculations conducted on the ground states of the nine M ⋅ RG diatomics (M = Ca, Sr, and Ba; RG = Ar, Kr, and Xe) at the coupled cluster single, double, and non-iterative triple level of theory revealed long bond lengths (>5 Å) and shallow bound regions (atoms in a single substitutional site of the solid rare gas is unlikely, with the possible exception of Ca/Xe. The luminescence of metal dimer bands has been recorded for Ba and Sr revealing very different behaviours. Resonance fluorescence with a lifetime of 15 ns is observed for the lowest energy transition of Sr2 while this transition is quenched in Ba2. This behaviour is consistent with the absence of vibrational structure on the dimer absorption band in Ba2 indicating lifetime broadening arising from efficient relaxation to low-lying molecular states. More extensive 2D excitation-emission data recorded for the complex site structures present on the absorption bands of the atomic Ba and Sr systems will be presented in future publications.

  17. Characterization of the physico-chemical properties of polymeric materials for aerospace flight. [differential thermal and atomic absorption spectroscopic analysis of nickel cadmium batteries

    Science.gov (United States)

    Rock, M.

    1981-01-01

    Electrodes and electrolytes of nickel cadmium sealed batteries were analyzed. Different thermal analysis of negative and positive battery electrodes was conducted and the temperature ranges of occurrence of endotherms indicating decomposition of cadmium hydroxide and nickel hydroxide are identified. Atomic absorption spectroscopy was used to analyze electrodes and electrolytes for traces of nickel, cadmium, cobalt, and potassium. Calibration curves and data are given for each sample analyzed. Instrumentation and analytical procedures used for each method are described.

  18. Application of factorial design and Doehlert matrix in the optimisation of instrumental parameters for direct determination of silicon in naphtha using graphite furnace atomic absorption spectrometry

    OpenAIRE

    Amaro, Joana Angélica de Azerêdo; Ferreira, Sergio Luis Costa

    2004-01-01

    p. 246 – 249 A method for direct determination of silicon in naphtha samples using graphite furnace atomic absorption spectrometry (GFAAS) is proposed. The optimisation of the instrumental conditions was multivariate using a fractional factorial design and Doehlert matrix. Firstly, the fractional factorial design was performed for preliminary evaluation of the significance of the factors, the factors chosen being: sample volume, atomisation temperature, pyrolysis time and pyrolysis temp...

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

    OpenAIRE

    Siriangkhawut, Watsaka; Sittichan, Patcharee; Ponhong, Kraingkrai; Chantiratikul, Piyanete

    2017-01-01

    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 digesti...

  20. Using laser absorption techniques to monitor diesel particulate matter exposure in underground stone mines

    Science.gov (United States)

    Noll, James; Janisko, Sam

    2007-09-01

    Underground miners are exposed to some of the highest levels of diesel particulate matter (DPM) in the United States. Therefore, it is important to monitor the exposure of miners to DPM, but it can be difficult because of the complex composition of DPM and the number of interferences. Currently, elemental carbon (EC) is used as a surrogate because it makes up a significant fraction of the DPM and is not affected by interferences. Standard measurement methods for EC can be time consuming and only record end of shift results. In this research, a laser absorption technique that enables one to measure EC concentration in near real time was shown to be a beneficial tool. The real time data showed that the fresh air being drawn into a stone mine was not properly reaching the working area and needed to be redirected to decrease DPM concentrations. The real time data also provided a more accurate efficiency of an environmental cab compared to just using the standard method by detecting the opening of the cab's window and door. The EC optical monitor was also worn by researchers in a mine to show how it can give not only the average concentration for the shift but also reveal when and where a miner is exposed to DPM.

  1. Spectral light absorption by ambient aerosols influenced by biomass burning in the Amazon Basin I. Comparison and field calibration of absorption measurement techniques

    Science.gov (United States)

    Schmid, O.; Artaxo, P.; Arnott, W. P.; Chand, D.; Gatti, L. V.; Frank, G. P.; Hoffer, A.; Schnaiter, M.; Andreae, M. O.

    2005-09-01

    Spectral aerosol light absorption is an important parameter for the assessment of the radiation budget of the atmosphere. Although on-line measurement techniques for aerosol light absorption, such as the Aethalometer and the Particle Soot Absorption Photometer (PSAP), have been available for two decades, they are limited in accuracy and spectral resolution because of the need to deposit the aerosol on a filter substrate before measurement. Recently, a 7-wavelength (λ) Aethalometer became commercially available, which covers the visible (VIS) to near-infrared (NIR) spectral range (λ=450-950 nm), and laboratory calibration studies improved the degree of confidence in these measurement techniques. However, the applicability of the laboratory calibration factors to ambient conditions has not been investigated thoroughly yet. As part of the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia - SMOke aerosols, Clouds, rainfall and Climate) campaign from September to November 2002 in the Amazon basin we performed an extensive field calibration of a 1-λ PSAP and a 7-λ Aethalometer utilizing a photoacoustic spectrometer (PAS, 532 nm) as reference device. Especially during the dry period of the campaign, the aerosol population was dominated by pyrogenic emissions. The most pronounced artifact of integrating-plate type attenuation techniques is due to multiple scattering effects within the filter matrix. For the PSAP, we essentially confirmed the laboratory calibration factor by Bond (1999). On the other hand, for the Aethalometer we found a multiple scattering enhancement of 5.23 (or 4.55, if corrected for aerosol scattering), which is significantly larger than the factors previously reported (~2). While the exact reason for this discrepancy is unknown, the available data from the present and previous studies suggest aerosol mixing (internal versus external) as a likely cause. While it is well-known that RH may (moderately) affect aerosol absorption, we

  2. Electrical characterization of grain boundaries of CZTS thin films using conductive atomic force microscopy techniques

    Energy Technology Data Exchange (ETDEWEB)

    Muhunthan, N.; Singh, Om Pal [Compound Semiconductor Solar Cell, Physics of Energy Harvesting Division, New Delhi 110012 (India); Toutam, Vijaykumar, E-mail: toutamvk@nplindia.org [Quantum Phenomena and Applications Division, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Singh, V.N., E-mail: singhvn@nplindia.org [Compound Semiconductor Solar Cell, Physics of Energy Harvesting Division, New Delhi 110012 (India)

    2015-10-15

    Graphical abstract: Experimental setup for conducting AFM (C-AFM). - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) thin film was grown by reactive co-sputtering. • The electronic properties were probed using conducting atomic force microscope, scanning Kelvin probe microscopy and scanning capacitance microscopy. • C-AFM current flow mainly through grain boundaries rather than grain interiors. • SKPM indicated higher potential along the GBs compared to grain interiors. • The SCM explains that charge separation takes place at the interface of grain and grain boundary. - Abstract: Electrical characterization of grain boundaries (GB) of Cu-deficient CZTS (Copper Zinc Tin Sulfide) thin films was done using atomic force microscopic (AFM) techniques like Conductive atomic force microscopy (CAFM), Kelvin probe force microscopy (KPFM) and scanning capacitance microscopy (SCM). Absorbance spectroscopy was done for optical band gap calculations and Raman, XRD and EDS for structural and compositional characterization. Hall measurements were done for estimation of carrier mobility. CAFM and KPFM measurements showed that the currents flow mainly through grain boundaries (GB) rather than grain interiors. SCM results showed that charge separation mainly occurs at the interface of grain and grain boundaries and not all along the grain boundaries.

  3. 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.

  4. The influence of higher spatial harmonics of atomic polarization on the saturated absorption resonance upon excitation of open dipole transitions by a field of counterpropagating waves

    Science.gov (United States)

    Brazhnikov, D. V.; Novokreshchenov, A. S.

    2017-04-01

    The effect of a double structure of saturated absorption resonance in the field of counterpropagating light waves interacting with an atomic gas is studied. The experimental observation of this effect was first reported in 2011 in a work by our colleagues at the P.N. Lebedev Physical Institute of the Russian Academy of Sciences (Laboratory of Frequency Standards). The essence of the effect lies in the fact that, on exciting an open dipole transition, another, narrower, resonance of an opposite sign can be observed at the center of the ordinary saturated absorption resonance. A theoretical analysis of this effect has also been performed in this work in terms of a simple spectroscopic model of an atom with two nondegenerate energy levels without taking into account higher spatial harmonics of atomic polarization and polarizations of light waves (scalar model). The present work is devoted to the development of a theory of the formation of a central narrow resonance for the example of a real F g = 1 → F e = 1 atomic transition and to the study of its main characteristics (amplitude, width, contrast, and amplitude-to-width ratio). In addition, the theoretical results obtained without taking into account the influence of higher spatial harmonics and with inclusion of the influence of first higher harmonics are compared. This comparison shows that their influence on the parameters of the new nonlinear resonance is strong even in moderately intense light fields ( R γ, where R is the Rabi frequency). The results of this study can be of interest for quantum metrology, as well as for many experiments in which the laser-radiation frequency is stabilized by the saturated absorption resonance on open dipole transitions in atoms and molecules.

  5. Atomic Oxygen Treatment Technique for Removal of Smoke Damage from Paintings

    Science.gov (United States)

    Rutledge, S. K.; Banks, B. A.

    1997-01-01

    Soot deposits that can accumulate on surfaces of a painting during a fire can be difficult to clean from some types of paintings without damaging the underlying paint layers. A non-contact technique has been developed which can remove the soot by allowing a gas containing atomic oxygen to flow over the surface and chemically react with the soot to form carbon monoxide and carbon dioxide. The reaction is limited to the surface, so the underlying paint is not touched. The process can be controlled so that the cleaning can be stopped once the paint surface is reached. This paper describes the smoke exposure and cleaning of untreated canvas, acrylic gesso, and sections of an oil painting using this technique. The samples were characterized by optical microscopy and reflectance spectroscopy.

  6. Atomic layer deposition (ALD): A versatile technique for plasmonics and nanobiotechnology.

    Science.gov (United States)

    Im, Hyungsoon; Wittenberg, Nathan J; Lindquist, Nathan C; Oh, Sang-Hyun

    2012-02-28

    While atomic layer deposition (ALD) has been used for many years as an industrial manufacturing method for microprocessors and displays, this versatile technique is finding increased use in the emerging fields of plasmonics and nanobiotechnology. In particular, ALD coatings can modify metallic surfaces to tune their optical and plasmonic properties, to protect them against unwanted oxidation and contamination, or to create biocompatible surfaces. Furthermore, ALD is unique among thin-film deposition techniques in its ability to meet the processing demands for engineering nanoplasmonic devices, offering conformal deposition of dense and ultra-thin films on high-aspect-ratio nanostructures at temperatures below 100 °C. In this review, we present key features of ALD and describe how it could benefit future applications in plasmonics, nanosciences, and biotechnology.

  7. Imaging of Au nanoparticles deeply buried in polymer matrix by various atomic force microscopy techniques.

    Science.gov (United States)

    Kimura, Kuniko; Kobayashi, Kei; Matsushige, Kazumi; Yamada, Hirofumi

    2013-10-01

    Recently, some papers reported successful imaging of subsurface features using atomic force microscopy (AFM). Some theoretical studies have also been presented, however the imaging mechanisms are not fully understood yet. In the preceeding papers, imaging of deeply buried nanometer-scale features has been successful only if they were buried in a soft matrix. In this paper, subsurface features (Au nanoparticles) buried in a soft polymer matrix were visualized. To elucidate the imaging mechanisms, various AFM techniques; heterodyne force microscopy, ultrasonic atomic force microscopy (UAFM), 2nd-harmonic UAFM and force modulation microscopy (FMM) were employed. The particles buried under 960 nm from the surface were successfully visualized which has never been achieved. The results elucidated that it is important for subsurface imaging to choose a cantilever with a suitable stiffness range for a matrix. In case of using the most suitable cantilever, the nanoparticles were visualized using every technique shown above except for FMM. The experimental results suggest that the subsurface features buried in a soft matrix with a depth of at least 1 µm can affect the local viscoelasticity (mainly viscosity) detected as the variation of the amplitude and phase of the tip oscillation on the surface. This phenomenon presumably makes it possible to visualize such deeply buried nanometer-scale features in a soft matrix. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Accelerating All-Atom MD Simulations of Lipids Using a Modified Virtual-Sites Technique.

    Science.gov (United States)

    Loubet, Bastien; Kopec, Wojciech; Khandelia, Himanshu

    2014-12-09

    We present two new implementations of the virtual sites technique which completely suppresses the degrees of freedom of the hydrogen atoms in a lipid bilayer allowing for an increased time step of 5 fs in all-atom simulations of the CHARMM36 force field. One of our approaches uses the derivation of the virtual sites used in GROMACS while the other uses a new definition of the virtual sites of the CH2 groups. Our methods is tested on a DPPC (no unsaturated chain), a POPC (one unsaturated chain), and a DOPC (two unsaturated chains) lipid bilayers. We calculate various physical properties of the membrane of our simulations with and without virtual sites and explain the differences and similarity observed. The best agreements are obtained for the GROMACS original virtual sites on the DOPC bilayer where we get an area per lipid of 67.3 ± 0.3 Å(2) without virtual sites and 67.6 ± 0.3 Å(2) with virtual sites. In conclusion the virtual-sites technique on lipid membranes is a powerful simulation tool, but it should be used with care. The procedure can be applied to other force fields and lipids in a straightforward manner.

  9. On-line sample processing involving microextraction techniques as a front-end to atomic spectrometric detection for trace metal assays: A review

    Energy Technology Data Exchange (ETDEWEB)

    Miró, Manuel, E-mail: manuel.miro@uib.es [FI-TRACE Group, Department of Chemistry, Faculty of Sciences, University of the Balearic Islands, E-07122 Palma de Mallorca, Illes Balears (Spain); Hansen, Elo Harald [Granåsen 93, DK-2800 Kgs. Lyngby (Denmark)

    2013-06-11

    Graphical abstract: -- Highlights: •Role of flow injection in automation of microextraction techniques for metal assays. •On-line coupling of liquid phase microextraction (LPME) to atomic spectrometry. •Critical evaluation of on-line single drop and dispersive LPME. •On-line coupling of micro-solid phase extraction (μSPE) to atomic spectrometry. •Critical appraisal of magnetic/carbon nanoparticles and biomass for on-line μSPE. -- Abstract: Within the last decade, liquid-phase microextraction (LPME) and micro-solid phase extraction (μSPE) approaches have emerged as substitutes for conventional sample processing procedures for trace metal assays within the framework of green chemistry. This review surveys the progress of the state of the art in simplification and automation of microextraction approaches by harnessing to the various generations of flow injection (FI) as a front end to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS) or inductively coupled plasma atomic emission spectrometry or mass spectrometry (ICP-AES/MS). It highlights the evolution of flow injection analysis and related techniques as vehicles for appropriate sample presentation to the detector and expedient on-line matrix separation and pre-concentration of trace levels of metals in troublesome matrices. Rather than being comprehensive this review is aimed at outlining the pros and cons via representative examples of recent attempts in automating green sample preparation procedures in an FI or sequential injection (SI) mode capitalizing on single-drop microextraction, dispersive liquid-phase microextraction and advanced sorptive materials including carbon and metal oxide nanoparticles, ion imprinted polymers, superparamagnetic nanomaterials and biological/biomass sorbents. Current challenges in the field are identified and the synergetic combination of flow analysis, nanotechnology and metal-tagged biomolecule detection is envisaged.

  10. Lead and cadmium in human teeth from Jordan by atomic absorption spectrometry: Some factors influencing their concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Alomary, A. [Department of Chemistry, Yarmouk University, Irbid (Jordan)]. E-mail: ahmedalomary1000@hotmail.com; Al-Momani, I.F. [Department of Chemistry, Yarmouk University, Irbid (Jordan); Massadeh, A.M. [Department of Medicinal Chemistry and Pharmacognosy, Faculty of Pharmacy, Jordan University of Science and Technology, Irbid (Jordan)

    2006-10-01

    The aim of this study was to measure the concentrations of lead (Pb) and cadmium (Cd) in human teeth and to investigate the affecting factors. Teeth samples (n = 268) were collected from people living in different cities in Jordan including Amman, Zarqa, Al-Mafraq and Irbid and analyzed for Pb and Cd using atomic absorption spectrometry (AAS). A questionnaire was used to gather information on each person, such as age, sex, place where the patient lives, smoking, presence of amalgam fillings inside the mouth, and whether the patient uses toothpaste or not. The mean concentrations of Pb and Cd were 28.91 {mu}g/g and 0.44 {mu}g/g, respectively. The results indicate that there is a clear relation between Pb and Cd concentrations and the presence of amalgam fillings, smoking, and place of living. Pb was sex-dependent, whereas Cd was not. Our results show that Pb and Cd concentrations in samples obtained from Al-Mafraq and Irbid are higher than those obtained from Amman and Zarqa. Pb was highest in Mafraq, whereas Cd was highest in Irbid. The Pb and Cd concentrations in teeth from smokers (means: Pb = 31.89 {mu}g/g, Cd = 0.49 {mu}g/g) were significantly higher than those from nonsmokers (means: Pb = 24.07 {mu}g/g, Cd = 0.37 {mu}g/g). Pb and Cd concentrations in teeth of patients with amalgam fillings (means: Pb = 31.02 {mu}g/g and Cd = 0.52 {mu}g/g) were significantly higher than those from patients without amalgam fillings (means: Pb = 26.87 {mu}g/g and Cd = 0.41 {mu}g/g). Our results show that brushing the teeth daily with toothpaste does not significantly decrease the concentration of both Pb and Cd. The mean concentrations of Pb and Cd do not vary significantly between the ages 20-30, 31-40, and 41-50, but both increased rapidly at age 51-60.

  11. Determination of palladium in various samples by atomic absorption spectrometry after preconcentration with dimethylglyoxime on silica gel

    Energy Technology Data Exchange (ETDEWEB)

    Tokalioglu, Serife; Oymak, Tuelay; Kartal, Senol

    2004-05-31

    A preconcentration method based on the adsorption of palladium-dimethylglyoxime (DMG) complex on silica gel for the determination of palladium at trace levels by atomic absorption spectrometry (AAS) has been developed. The retained palladium as Pd(DMG){sub 2} complex was eluted with 1 mol l{sup -1} HCl in acetone. The effect of some analytical parameters such as pH, amount of reagent and the sample volume on the recovery of palladium was examined in synthetic solutions containing street dust matrix. The influence of some matrix ions on the recovery of palladium was investigated by using the developed method when the elements were present both individually and together. The results showed that 2500 {mu}g ml{sup -1} Na{sup +}, K{sup +}, Mg{sup 2+}, Al{sup 3+} and Fe{sup 3+}; 5000 {mu}g ml{sup -1} Ca{sup 2+} ; 500 {mu}g ml{sup -1} Pb{sup 2+}; 125 {mu}g ml{sup -1} Zn{sup 2+}; 50 {mu}g ml{sup -1} Cu{sup 2+} and 25 {mu}g ml{sup -1} Ni{sup 2+} did not interfere with the palladium signal. At the optimum conditions determined experimentally, the recovery for palladium was found to be 95.3{+-}1.2% at the 95% confidence level. The relative standard deviation and limit of detection (3s/b) of the method were found to be 1.7% and 1.2 {mu}g l{sup -1}, respectively. In order to determine the adsorption behaviour of silica gel, the adsorption isotherm of palladium was studied and the binding equilibrium constant and adsorption capacity were calculated to be 0.38 l mg{sup -1} and 4.06 mg g{sup -1}, respectively. The determination of palladium in various samples was performed by using both flame AAS and graphite furnace AAS. The proposed method was successfully applied for the determination of palladium in the street dust, anode slime, rock and catalytic converter samples.

  12. Restricted access carbon nanotubes for direct extraction of cadmium from human serum samples followed by atomic absorption spectrometry analysis.

    Science.gov (United States)

    Barbosa, Adriano F; Barbosa, Valéria M P; Bettini, Jefferson; Luccas, Pedro O; Figueiredo, Eduardo C

    2015-01-01

    In this paper, we propose a new sorbent that is able to extract metal ions directly from untreated biological fluids, simultaneously excluding all proteins from these samples. The sorbent was obtained through the modification of carbon nanotubes (CNTs) with an external bovine serum albumin (BSA) layer, resulting in restricted access carbon nanotubes (RACNTs). The BSA layer was fixed through the interconnection between the amine groups of the BSA using glutaraldehyde as cross-linker. When a protein sample is percolated through a cartridge containing RACNTs and the sample pH is higher than the isoelectric point of the proteins, both proteins from the sample and the BSA layer are negatively ionized. Thus, an electrostatic repulsion prevents the interaction between the proteins from the sample on the RACNTs surface. At the same time, metal ions are adsorbed in the CNTs (core) after their passage through the chains of proteins. The Cd(2+) ion was selected for a proof-of-principle case to test the suitability of the RACNTs due to its toxicological relevance. RACNTs were able to extract Cd(2+) and exclude almost 100% of the proteins from the human serum samples in an online solid-phase extraction system coupled with thermospray flame furnace atomic absorption spectrometry. The limits of detection and quantification were 0.24 and 0.80 μg L(-1), respectively. The sampling frequency was 8.6h(-1), and the intra- and inter-day precisions at the 0.80, 15.0, and 30.0 μg L(-1) Cd(2+) levels were all lower than 10.1% (RSD). The recoveries obtained for human blood serum samples fortified with Cd(2+) ranged from 85.0% to 112.0%. The method was successfully applied to analyze Cd(2+) directly from six human blood serum samples without any pretreatment, and the observed concentrations ranged from

  13. Comparison of different sample preparation methods for platinum determination in cultured cells by graphite furnace atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Man Xiao

    2017-01-01

    Full Text Available Background Platinum-based agents are widely used in chemotherapy against solid tumors and insufficient intracellular drug accumulation is one of the leading causes of platinum resistance which is associated with poor survival of tumor patients. Thus, the detection of intracellular platinum is pivotal for studies aiming to overcome platinum resistance. In the present study, we aimed to establish a reliable graphite furnace atomic absorption spectrometry (GFAAS-based assay to quantify the intracellular platinum content for cultured cells. Methods Several most commonly applied cell preparation methods, including 0.2% HNO3, 0.2% Triton X-100, concentrated nitric acid, RIPA combined with concentrated nitric acid and hydroxide, followed by GFAAS for platinum detection were compared in ovarian, cervical and liver cancer cell lines to obtain the optimal one, and parameters regarding linearity, accuracy, precision and sensitivity were evaluated. Influence of other metals on platinum detection and the storage conditions of samples were also determined. Results The treatment of cells with 0.2% HNO3 was superior to other approaches with fewer platinum loss and better repeatability. The recovery rate and precision of this method were 97.3%–103.0% and 1.4%–3.8%, respectively. The average recoveries in the presence of other metals were 95.1%–103.1%. The detection limit was 13.23 ug/L. The recovery rate of platinum remained acceptable even in cell samples stored in −20 °C or −80 °C for two months. Discussion After comparison, we found that 0.2% HNO3 was optimal for intracellular platinum quantification based on GFAAS, which presented values compatible with that of inductively-coupled plasma mass-spectrometry (ICP-MS, and this is partially attributed to the simplicity of this method. Moreover, the assay was proved to be accurate, sensitive, cost-effective and suitable for the research of platinum-based antitumor therapy.

  14. Ultrasound-assisted single-drop microextraction for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Jorge S.; Anunciação, Taiana A. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Brandão, Geovani C. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); INCT de Energia e Ambiente, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Dantas, Alailson F. [Departamento de Química Analítica, Instituto de Química, Universidade Federal da Bahia, Campus Universitário de Ondina, Salvador, Bahia 40170-280 (Brazil); Lemos, Valfredo A. [Laboratório de Química Analítica (LQA), Universidade Estadual do Sudoeste da Bahia, Campus de Jequié, Jequié, Bahia 45506-191 (Brazil); and others

    2015-05-01

    This work presents an ultrasound-assisted single-drop microextraction procedure for the determination of cadmium in vegetable oils using high-resolution continuum source electrothermal atomic absorption spectrometry. Some initial tests showed that the best extraction efficiency was obtained when using ultrasound instead of mechanical agitation, indicating that acoustic cavitation improved the extraction process. Nitric, hydrochloric and acetic acids were evaluated for use in the extraction process, and HNO{sub 3} gave the best results. A two-level full-factorial design was applied to investigate the best conditions for the extraction of Cd from the oil samples. The influences of the sonication amplitude, time and temperature of the extraction were evaluated. The results of the design revealed that all of the variables had a significant effect on the experimental results. Afterward, a Box–Behnken design was applied to determine the optimum conditions for the determination of cadmium in vegetable oil samples. According to a multivariate study, the optimum conditions were as follows: sonication amplitude of 60%, extraction time of 15 min, extraction temperature of 46 °C and 0.1 mol L{sup −1} HNO{sub 3} as the extractor solution. Under optimized conditions, the developed method allows for the determination of Cd in oil samples with a limit of quantification of 7.0 ng kg{sup −1}. Addition and recovery experiments were performed in vegetable oil samples to evaluate the accuracy of the method, and the recoveries obtained varied from 90% to 115%. The samples were also analyzed after the acid digestion procedure, and the paired t-test (95% confidence level) did not show significant differences from the proposed method. - Highlights: • The determination of cadmium in vegetable oils was developed using UA-SDME. • HR-CS ET-AAS was employed as a detection technique with direct drop sampling. • The procedure allowed for a reduction in the consumption of reagents and

  15. Trace determination of lead, chromium and cadmium in herbal medicines using ultrasound-assisted emulsification microextraction combined with graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Aghamohammadi, Mohammad; Faraji, Mahya; Shahdousti, Parvin; Kalhor, Hamideh; Saleh, Abolfazl

    2015-01-01

    The World Health Organization (WHO) recommends that medicinal plants should be checked for the presence of heavy metals. A preconcentration and separation technique for trace amounts of heavy metals from plant matrix is necessary in order to increase the sensitivity and precision of their determination. Lead, chromium and cadmium contaminations in herbal medicines were monitored using ultrasound-assisted emulsification microextraction (USAEME) combined with graphite furnace atomic absorption spectrometry (GF-AAS). In this work, the metal ions in the aqueous solution were complexed with ammonium pyrrolidine dithiocarbamate (APDC) and were extracted into 45 μL of toluene that was sonically dispersed in the aqueous phase. The emulsion formed was centrifuged and 20 μL of separated toluene was injected into a GF-AAS for analysis. Several factors including the kind of extraction solvent and its volume, sample pH, ionic strength and concentration of APDC were optimised. The linear dynamic range (LDR) values were in the range of 0.05 to 20 µg/L and the limit of detection values were in the range of 0.002-0.03 µg/L for target heavy metals. Enrichment factors were obtained in the range of 70-500. The precision of the proposed method was ≤ 8% (n = 5). The obtained amounts of Pb, Cr and Cd in selected herbal medicines were in the standard range, according to the WHO reports. The USAEME with GF-AAS procedure was shown to be an efficient, rapid, inexpensive and eco-friendly method for the determination of lead, chromium and cadmium in herbal medicines. Application of the USAEME method leads to an increased extraction efficiency with satisfactory precision in a short time using an extraction solvent volume at the microlitre level. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Trace determination of lead in lipsticks and hair dyes using microwave-assisted dispersive liquid-liquid microextraction and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Sharafi, K; Fattahi, N; Pirsaheb, M; Yarmohamadi, H; Fazlzadeh Davil, M

    2015-10-01

    A novel microwave-assisted dispersive liquid-liquid microextraction (MADLLME) technique according to the solidification of a floating organic droplet (SFO) and graphite furnace atomic absorption spectrometry (GFAAS) used for the extraction and determination of lead ions in lipsticks and hair dyes made in different countries. Lipstick and hair dye samples of different brands and colours were collected from local market in Kermanshah, Iran. After sample treatment with microwave-assisted acid digestion, an appropriate mixture of acetone, 1-undecanol and diethyl dithiophosphoric acid was injected rapidly into the aqueous sample containing lead ions, and as a result, cloudy mixture was formed. After centrifugation, the test tube was cooled for few minutes. The solidified 1-undecanol on top of the solution was transferred into a suitable vial and injected into the analytical instrument. Under the optimum experimental conditions (extraction solvent: 30 μL of 1-undecanol; disperser solvent: 500 μL of acetone; ligand concentration: 0.15% (v/v); pH: ~1.5 and without salt added), the enhancement factor of 96 was obtained. The calibration graphs were linear in the range of 0.3-50 μg kg(-1) with a correlation coefficient (r(2) ) more than 0.995. The detection limit was 0.1 μg kg(-1) . Consequently, the developed method was successfully applied to extract and determine lead ions in the lipsticks and hair dyes, and favourable results were obtained. The proposed method which applied in cosmetics showed excellent relative recoveries (90-109.7%) with relative standard deviations market is far below the recommended limits as applied in Germany (20 mg kg(-1) ) and Canada (10 mg kg(-1) ) and confirmed that very low levels of lead are technically available in the final cosmetic products. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  17. 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.

  18. 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

    2017-07-01

    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.

  19. Crosslinked poly (4-vinylpyridine-ethylene glycol dimethacrylate) used for preconcentration of Cd(II) and its determination by flow injection flame atomic absorption spectrometry.

    Science.gov (United States)

    Tarley, César Ricardo Teixeira; Farias, Natália Cristina Botteon; Lima, Giovana de Fátima; de Oliveira, Fernanda Midori; Bonfílio, Rudy; Dragunski, Douglas Cardoso; Clausen, Débora Nobile; Segatelli, Mariana Gava

    2014-01-01

    The main purpose of this research was to synthesize crosslinked poly(4-vinylpyridine-ethylene glycol dimethacrylate) and evaluate its feasibility for highly sensitive and selective determination of Cd in water samples by using flow injection flame atomic absorption spectrometry. The crosslinked polymer, prepared by bulk polymerization, was characterized by FTIR spectrometry and scanning electron microscopy. The flow injection solid-phase method was based on preconcentration of 20.0 mL of sample through 100 mg of the polymer packed into a minicolumn at pH 8.25 using a flow rate of 6.0 mL/min, followed by elution with 1.0 M HNO3. The sample solution parameters influencing the preconcentration behavior of Cd ions, such as pH, buffer concentration, and flow rate, were simultaneously studied and optimized using a Doehlert matrix. Values of 0.10 microg/L, 2.0-210 microg/L, 32.3, 18/h, 9.7/min, and 0.62 mL were obtained for LOD, linear range, preconcentration factor, sample throughput, concentration efficiency, and consumption index, respectively. The effect of the presence of the inorganic cations Pb(II), U(IV), Co(II), Hg(II), Cu(II), As(II), Mg(II), Sb(III), Ni(II), Th(IV), Ba(II), and Ca(II) on the method was studied, and the preconcentration of Cd was observed to have no interference. The accuracy of the method was assessed by analysis of natural water samples using addition and recovery tests and inductively coupled plasma/MS as a reference technique, as well as by analysis of a standard reference material of trace elements in water.

  20. Disordered Nanohole Patterns in Metal-Insulator Multilayer for Ultra-broadband Light Absorption: Atomic Layer Deposition for Lithography Free Highly repeatable Large Scale Multilayer Growth.

    Science.gov (United States)

    Ghobadi, Amir; Hajian, Hodjat; Dereshgi, Sina Abedini; Bozok, Berkay; Butun, Bayram; Ozbay, Ekmel

    2017-11-08

    In this paper, we demonstrate a facile, lithography free, and large scale compatible fabrication route to synthesize an ultra-broadband wide angle perfect absorber based on metal-insulator-metal-insulator (MIMI) stack design. We first conduct a simulation and theoretical modeling approach to study the impact of different geometries in overall stack absorption. Then, a Pt-Al2O3 multilayer is fabricated using a single atomic layer deposition (ALD) step that offers high repeatability and simplicity in the fabrication step. In the best case, we get an absorption bandwidth (BW) of 600 nm covering a range of 400 nm-1000 nm. A substantial improvement in the absorption BW is attained by incorporating a plasmonic design into the middle Pt layer. Our characterization results demonstrate that the best configuration can have absorption over 0.9 covering a wavelength span of 400 nm-1490 nm with a BW that is 1.8 times broader compared to that of planar design. On the other side, the proposed structure retains its absorption high at angles as wide as 70°. The results presented here can serve as a beacon for future performance enhanced multilayer designs where a simple fabrication step can boost the overall device response without changing its overall thickness and fabrication simplicity.

  1. A new technique to assess dermal absorption of chemical vapor in vitro by thermogravimetric analysis (TGA)

    OpenAIRE

    Rauma, Matias

    2008-01-01

    There is a huge lack of dermal uptake data for chemicals, and it is frequent with large variations in reported permeability coefficients for chemicals with more than one data set, showing the need for a new and standardized in vitro method. The overall aim of this thesis was to develop the new method of measuring dermal absorption of chemical vapor using the TGA method. Assessment of dermal absorption by TGA (Study I) Round pieces (ø8 mm) of pig epidermis were placed on ...

  2. Time Domain Technique for Rapid, Broadband Measurement of Human Absorption Cross Section in a Reverberation Chamber

    OpenAIRE

    Robinson, Martin P; Zhang, Xiaotian; Flintoft, Ian D.

    2017-01-01

    Absorption cross section (ACS) of an object is used in stochastic power balance models, while human ACS is closely related to microwave dosimetry parameters such as specific absorption rate (SAR) and thus characterises exposure as well as effect of human bodies on multipath propagation. ACS, averaged over all directions of incidence, can be obtained in the frequency domain from the S-parameters of two antennas in a stirred-mode reverberation chamber; however, our new time domain method is fas...

  3. Prediction of Human Intestinal Absorption of Compounds Using Artificial Intelligence Techniques.

    Science.gov (United States)

    Kumar, Rajnish; Sharma, Anju; Siddiqui, Mohammed Haris; Tiwari, Rajesh Kumar

    2017-01-01

    Information about Pharmacokinetics of compounds is an essential component of drug design and development. Modeling the pharmacokinetic properties require identification of the factors effecting absorption, distribution, metabolism and excretion of compounds. There have been continuous attempts in the prediction of intestinal absorption of compounds using various Artificial intelligence methods in the effort to reduce the attrition rate of drug candidates entering to preclinical and clinical trials. Currently, there are large numbers of individual predictive models available for absorption using machine learning approaches. Six Artificial intelligence methods namely, Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis were used for prediction of absorption of compounds. Prediction accuracy of Support vector machine, k- nearest neighbor, Probabilistic neural network, Artificial neural network, Partial least square and Linear discriminant analysis for prediction of intestinal absorption of compounds was found to be 91.54%, 88.33%, 84.30%, 86.51%, 79.07% and 80.08% respectively. Comparative analysis of all the six prediction models suggested that Support vector machine with Radial basis function based kernel is comparatively better for binary classification of compounds using human intestinal absorption and may be useful at preliminary stages of drug design and development. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Mass energy-absorption coefficients and average atomic energy-absorption cross-sections for amino acids in the energy range 0.122-1.330 MeV

    Energy Technology Data Exchange (ETDEWEB)

    More, Chaitali V., E-mail: chaitalimore89@gmail.com; Lokhande, Rajkumar M.; Pawar, Pravina P., E-mail: pravinapawar4@gmail.com [Department of physics, Dr. Babasaheb Ambedkar Marathwada University, Aurangabad 431004 (India)

    2016-05-06

    Mass attenuation coefficients of amino acids such as n-acetyl-l-tryptophan, n-acetyl-l-tyrosine and d-tryptophan were measured in the energy range 0.122-1.330 MeV. NaI (Tl) scintillation detection system was used to detect gamma rays with a resolution of 8.2% at 0.662 MeV. The measured attenuation coefficient values were then used to determine the mass energy-absorption coefficients (σ{sub a,en}) and average atomic energy-absorption cross sections (μ{sub en}/ρ) of the amino acids. Theoretical values were calculated based on XCOM data. Theoretical and experimental values are found to be in good agreement.

  5. Correlation between Wavelength Dispersive X-ray Fluorescence (WDXRF) analysis of hardened concrete for chlorides vs. Atomic Absorption (AA) analysis in accordance with AASHTO T- 260; sampling and testing for chloride ion in concrete and concrete raw mater

    Science.gov (United States)

    2014-04-01

    A correlation between Wavelength Dispersive X-ray Fluorescence(WDXRF) analysis of Hardened : Concrete for Chlorides and Atomic Absorption (AA) analysis (current method AASHTO T-260, procedure B) has been : found and a new method of analysis has been ...

  6. Implementation of suitable flow injection/sequential-sample separation/preconcentration schemes for determination of trace metal concentrations using detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Wang, Jianhua

    2002-01-01

    Various preconditioning procedures encomprising appropriate separation/preconcentration schemes in order to obtain optimal sensitivity and selectivity characteristics when using electrothermal atomic absorption spectrometry (ETAAS) and inductively coupled plasma mass spectrometry (ICPMS...

  7. 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. MnO2 will be reduced to Mn(II) by sample injection in to the column under acidic carrier stream of HNO3 (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.

  8. 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.

  9. Development of nanostructured ZnO thin film via electrohydrodynamic atomization technique and its photoconductivity characteristics.

    Science.gov (United States)

    Duraisamy, Navaneethan; Kwon, Ki Rin; Jo, Jeongdai; Choi, Kyung-Hyun

    2014-08-01

    This article presents the non-vacuum technique for the preparation of nanostructured zinc oxide (ZnO) thin film on glass substrate through electrohydrodynamic atomization (EHDA) technique. The detailed process parameters for achieving homogeneous ZnO thin films are clearly discussed. The crystallinity and surface morphology of ZnO thin film are investigated by X-ray diffraction and field emission scanning electron microscopy. The result shows that the deposited ZnO thin film is oriented in the wurtzite phase with void free surface morphology. The surface roughness of deposited ZnO thin film is found to be ~17.8 nm. The optical properties of nanostructured ZnO thin films show the average transmittance is about 90% in the visible region and the energy band gap is found to be 3.17 eV. The surface chemistry and purity of deposited ZnO thin films are analyzed by fourier transform infrared and X-ray photoelectron spectroscopy, conforming the presence of Zn-O in the deposited thin films without any organic moiety. The photocurrent measurement of nanostructured ZnO thin film is examined in the presence of UV light illumination with wavelength of 365 nm. These results suggest that the deposited nanostructured ZnO thin film through EHDA technique possess promising applications in the near future.

  10. Coordinate space translation technique for simulation of electronic process in the ion-atom collision.

    Science.gov (United States)

    Wang, Feng; Hong, Xuhai; Wang, Jian; Kim, Kwang S

    2011-04-21

    Recently we developed a theoretical model of ion-atom collisions, which was made on the basis of a time-dependent density functional theory description of the electron dynamics and a classical treatment of the heavy particle motion. Taking advantage of the real-space grid method, we introduce a "coordinate space translation" technique to allow one to focus on a certain space of interest such as the region around the projectile or the target. Benchmark calculations are given for collisions between proton and oxygen over a wide range of impact energy. To extract the probability of charge transfer, the formulation of Lüdde and Dreizler [J. Phys. B 16, 3973 (1983)] has been generalized to ensemble-averaging application in the particular case of O((3)P). Charge transfer total cross sections are calculated, showing fairly good agreements between experimental data and present theoretical results.

  11. Site-controlled quantum dots fabricated using an atomic-force microscope assisted technique

    Directory of Open Access Journals (Sweden)

    Sakuma Y

    2006-01-01

    Full Text Available AbstractAn atomic-force microscope assisted technique is developed to control the position and size of self-assembled semiconductor quantum dots (QDs. Presently, the site precision is as good as ± 1.5 nm and the size fluctuation is within ± 5% with the minimum controllable lateral diameter of 20 nm. With the ability of producing tightly packed and differently sized QDs, sophisticated QD arrays can be controllably fabricated for the application in quantum computing. The optical quality of such site-controlled QDs is found comparable to some conventionally self-assembled semiconductor QDs. The single dot photoluminescence of site-controlled InAs/InP QDs is studied in detail, presenting the prospect to utilize them in quantum communication as precisely controlled single photon emitters working at telecommunication bands.

  12. Combined Acquisition Technique (CAT) for Neuroimaging of Multiple Sclerosis at Low Specific Absorption Rates (SAR)

    Science.gov (United States)

    Biller, Armin; Choli, Morwan; Blaimer, Martin; Breuer, Felix A.; Jakob, Peter M.; Bartsch, Andreas J.

    2014-01-01

    Purpose To compare a novel combined acquisition technique (CAT) of turbo-spin-echo (TSE) and echo-planar-imaging (EPI) with conventional TSE. CAT reduces the electromagnetic energy load transmitted for spin excitation. This radiofrequency (RF) burden is limited by the specific absorption rate (SAR) for patient safety. SAR limits restrict high-field MRI applications, in particular. Material and Methods The study was approved by the local Medical Ethics Committee. Written informed consent was obtained from all participants. T2- and PD-weighted brain images of n = 40 Multiple Sclerosis (MS) patients were acquired by CAT and TSE at 3 Tesla. Lesions were recorded by two blinded, board-certificated neuroradiologists. Diagnostic equivalence of CAT and TSE to detect MS lesions was evaluated along with their SAR, sound pressure level (SPL) and sensations of acoustic noise, heating, vibration and peripheral nerve stimulation. Results Every MS lesion revealed on TSE was detected by CAT according to both raters (Cohen’s kappa of within-rater/across-CAT/TSE lesion detection κCAT = 1.00, at an inter-rater lesion detection agreement of κLES = 0.82). CAT reduced the SAR burden significantly compared to TSE (pCAT were 29.0 (±5.7) % for the T2-contrast and 32.7 (±21.9) % for the PD-contrast (expressed as percentages of the effective SAR limit of 3.2 W/kg for head examinations). Average SPL of CAT was no louder than during TSE. Sensations of CAT- vs. TSE-induced heating, noise and scanning vibrations did not differ. Conclusion T2−/PD-CAT is diagnostically equivalent to TSE for MS lesion detection yet substantially reduces the RF exposure. Such SAR reduction facilitates high-field MRI applications at 3 Tesla or above and corresponding protocol standardizations but CAT can also be used to scan faster, at higher resolution or with more slices. According to our data, CAT is no more uncomfortable than TSE scanning. PMID:24608106

  13. Spectral light absorption by ambient aerosols influenced by biomass burning in the Amazon Basin. I: Comparison and field calibration of absorption measurement techniques

    Science.gov (United States)

    Schmid, O.; Artaxo, P.; Arnott, W. P.; Chand, D.; Gatti, L. V.; Frank, G. P.; Hoffer, A.; Schnaiter, M.; Andreae, M. O.

    2006-08-01

    Spectral aerosol light absorption is an important parameter for the assessment of the radiation budget of the atmosphere. Although on-line measurement techniques for aerosol light absorption, such as the Aethalometer and the Particle Soot Absorption Photometer (PSAP), have been available for two decades, they are limited in accuracy and spectral resolution because of the need to deposit the aerosol on a filter substrate before measurement. Recently, a 7-wavelength (λ) Aethalometer became commercially available, which covers the visible (VIS) to near-infrared (NIR) spectral range (λ=450-950 nm), and laboratory calibration studies improved the degree of confidence in these measurement techniques. However, the applicability of the laboratory calibration factors to ambient conditions has not been investigated thoroughly yet. As part of the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia - SMOke aerosols, Clouds, rainfall and Climate) campaign from September to November 2002 in the Amazon basin we performed an extensive field calibration of a 1-λ PSAP and a 7-λ Aethalometer utilizing a photoacoustic spectrometer (PAS, 532 nm) as reference device. Especially during the dry period of the campaign, the aerosol population was dominated by pyrogenic emissions. The most pronounced artifact of integrating-plate type attenuation techniques (e.g. Aethalometer, PSAP) is due to multiple scattering effects within the filter matrix. For the PSAP, we essentially confirmed the laboratory calibration factor by Bond et al. (1999). On the other hand, for the Aethalometer we found a multiple scattering enhancement of 5.23 (or 4.55, if corrected for aerosol scattering), which is significantly larger than the factors previously reported (~2) for laboratory calibrations. While the exact reason for this discrepancy is unknown, the available data from the present and previous studies suggest aerosol mixing (internal versus external) as a likely cause. For Amazonian

  14. Spectral light absorption by ambient aerosols influenced by biomass burning in the Amazon Basin. I: Comparison and field calibration of absorption measurement techniques

    Directory of Open Access Journals (Sweden)

    O. Schmid

    2006-01-01

    Full Text Available Spectral aerosol light absorption is an important parameter for the assessment of the radiation budget of the atmosphere. Although on-line measurement techniques for aerosol light absorption, such as the Aethalometer and the Particle Soot Absorption Photometer (PSAP, have been available for two decades, they are limited in accuracy and spectral resolution because of the need to deposit the aerosol on a filter substrate before measurement. Recently, a 7-wavelength (λ Aethalometer became commercially available, which covers the visible (VIS to near-infrared (NIR spectral range (λ=450–950 nm, and laboratory calibration studies improved the degree of confidence in these measurement techniques. However, the applicability of the laboratory calibration factors to ambient conditions has not been investigated thoroughly yet. As part of the LBA-SMOCC (Large scale Biosphere atmosphere experiment in Amazonia – SMOke aerosols, Clouds, rainfall and Climate campaign from September to November 2002 in the Amazon basin we performed an extensive field calibration of a 1-λ PSAP and a 7-λ Aethalometer utilizing a photoacoustic spectrometer (PAS, 532 nm as reference device. Especially during the dry period of the campaign, the aerosol population was dominated by pyrogenic emissions. The most pronounced artifact of integrating-plate type attenuation techniques (e.g. Aethalometer, PSAP is due to multiple scattering effects within the filter matrix. For the PSAP, we essentially confirmed the laboratory calibration factor by Bond et al. (1999. On the other hand, for the Aethalometer we found a multiple scattering enhancement of 5.23 (or 4.55, if corrected for aerosol scattering, which is significantly larger than the factors previously reported (~2 for laboratory calibrations. While the exact reason for this discrepancy is unknown, the available data from the present and previous studies suggest aerosol mixing (internal versus external as a likely cause. For

  15. Marine sediments monitoring studies for trace elements with the application of fast temperature programs and solid sampling high resolution continuum source atomic absorption spectrometry

    Science.gov (United States)

    Orani, Anna Maria; Han, Eunmi; Mandjukov, Petko; Vassileva, Emilia

    2015-01-01

    Analytical procedure for the determination of As, Cd, Cu, Ni, Co and Cr in marine sediment samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS AAS) and direct solid sample analysis has been developed. The application of fast programs in combination with direct solid sampling allows to eliminate the drying and pretreatment steps, however makes impossible the use of liquid standards for calibration. Iridium treated platforms were applied throughout the present study. Calibration technique based on the use of solid certified reference materials (marine sediments) similar to the nature of the analyzed sample and statistics of regression analysis were applied to the real sediment samples. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signals. The ISO-17025 requirements and Eurachem guidelines were followed in the validation of the proposed analytical procedure. Accordingly, blanks, selectivity, calibration, linearity, working range, trueness, repeatability reproducibility, limits of detection and quantification and expanded uncertainty (k = 2) for all investigated elements were assessed. Two different approaches for the estimation of measurement uncertainty were applied and obtained results compared. The major contributors to the combined uncertainty of the analyte mass fraction were found to be the homogeneity of the samples and the microbalance precision. The influence of sample particle sizes on the total combined uncertainty was also evaluated. Traceability to SI system of units of the obtained by the proposed analytical procedure results was demonstrated. Additionally, validation of the methodology developed was effectuated by the comparison of the obtained results with independent method e.g. ICP-MS with external calibration. The use of solid sampling HR CS AAS for the determination of trace elements in marine sediment matrix gives significant advantages

  16. XUV Transient Absorption Spectroscopy: Probing Laser-Perturbed Dipole Polarization in Single Atom, Macroscopic, and Molecular Regimes

    OpenAIRE

    Chen-Ting Liao; Arvinder Sandhu

    2017-01-01

    We employ an extreme ultraviolet (XUV) pulse to impulsively excite dipole polarization in atoms or molecules, which corresponds to coherently prepared superposition of excited states. A delayed near infrared (NIR) pulse then perturbs the fast evolving polarization, and the resultant absorbance change is monitored in dilute helium, dense helium, and sulfur hexafluoride (SF6) molecules. We observe and quantify the time-dependence of various transient phenomena in helium atoms,includinglaser-indu...

  17. Determination of macro- and micronutrients in plant leaves by high-resolution continuum source flame atomic absorption spectrometry combining instrumental and sample preparation strategies

    Science.gov (United States)

    Oliveira, Silvana R.; Gomes Neto, José A.; Nóbrega, Joaquim A.; Jones, Bradley T.

    2010-04-01

    A method for determination of B, Ca, Cu, Fe, K, Mg, Mn, Mo, P, S and Zn in plant tissues by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) is proposed. This method is based on special features of HR-CS-AAS, such as side pixel registration, wavelength integrated absorbance, and molecular absorption bands, for determining macro- and micronutrients in foliar analysis without requiring several different strategies for sample preparation and adjustment of the analytes concentration ranges. Plant samples were analyzed and results for certified materials were in agreement at a 95% confidence level (paired t-test) with reference values. Recoveries of analytes added to plant digests varied within the 82-112% interval. Relative standard deviations ( n = 12) were lower than or equal to 5.7% for all analytes in all concentration ranges.

  18. 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.

  19. Uniform Fe3O4 coating on flower-like ZnO nanostructures by atomic layer deposition for electromagnetic wave absorption.

    Science.gov (United States)

    Wan, Gengping; Wang, Guizhen; Huang, Xianqin; Zhao, Haonan; Li, Xinyue; Wang, Kan; Yu, Lei; Peng, Xiange; Qin, Yong

    2015-11-21

    An elegant atomic layer deposition (ALD) method has been employed for controllable preparation of a uniform Fe3O4-coated ZnO (ZnO@Fe3O4) core-shell flower-like nanostructure. The Fe3O4 coating thickness of the ZnO@Fe3O4 nanostructure can be tuned by varying the cycle number of ALD Fe2O3. When serving as additives for microwave absorption, the ZnO@Fe3O4-paraffin composites exhibit a higher absorption capacity than the ZnO-paraffin composites. For ZnO@500-Fe3O4, the effective absorption bandwidth below -10 dB can reach 5.2 GHz and the RL values below -20 dB also cover a wide frequency range of 11.6-14.2 GHz when the coating thickness is 2.3 mm, suggesting its potential application in the treatment of the electromagnetic pollution problem. On the basis of experimental observations, a mechanism has been proposed to understand the enhanced microwave absorption properties of the ZnO@Fe3O4 composites.

  20. Dithizone chloroform single drop microextraction system combined with electrothermal atomic absorption spectrometry using Ir as permanent modifier for the determination of Cd in water and biological samples

    Science.gov (United States)

    Fan, Zhefeng; Zhou, Wei

    2006-07-01

    A simple and sensitive method using dithizone-chloroform single drop microextraction has been developed for separation and preconcentration of trace Cd prior to its determination by electrothermal atomic absorption spectrometry with Ir as permanent modifier. Parameters, such as pyrolysis and atomization temperature, solvent type, pH, dithizone concentration, extraction time, organic drop volume, stirring rate and sample volume were investigated. Under the optimized conditions, a detection limit (3 σ) of 0.7 ng/l and enrichment factor of 65 were achieved. The relative standard deviation was 7.4% ( c = 0.2 μg/l, n = 5). The developed method has been applied to the determination of trace Cd in water samples and biological reference materials with satisfactory results.

  1. Dithizone-chloroform single drop microextraction system combined with electrothermal atomic absorption spectrometry using Ir as permanent modifier for the determination of Cd in water and biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Fan Zhefeng [Department of Chemistry, Shanxi Normal University, Linfen 041004 (China)]. E-mail: zhefengfan@163.com; Zhou Wei [Department of Chemistry, Shanxi Normal University, Linfen 041004 (China)

    2006-07-15

    A simple and sensitive method using dithizone-chloroform single drop microextraction has been developed for separation and preconcentration of trace Cd prior to its determination by electrothermal atomic absorption spectrometry with Ir as permanent modifier. Parameters, such as pyrolysis and atomization temperature, solvent type, pH, dithizone concentration, extraction time, organic drop volume, stirring rate and sample volume were investigated. Under the optimized conditions, a detection limit (3{sigma}) of 0.7 ng/l and enrichment factor of 65 were achieved. The relative standard deviation was 7.4% (c = 0.2 {mu}g/l, n = 5). The developed method has been applied to the determination of trace Cd in water samples and biological reference materials with satisfactory results.

  2. Saturated-absorption spectroscopy revisited: atomic transitions in strong magnetic fields ($>$20 mT) with a micrometer-thin cell

    OpenAIRE

    Sargsyan, A.; Tonoyan, A.(Department for Physics and Technology, University of Bergen, Bergen, Norway); Mirzoyan, R.; Sarkisyan, D; Stabrawa, A. M. Wojciechowski A.; Gawlik, W.

    2014-01-01

    The existence of cross-over resonances makes saturated-absorption spectra very complicated when external magnetic field B is applied. It is demonstrated for the first time that the use of micrometric-thin cells (MTC, $L\\approx40\\,\\mu$m) allows application of SA for quantitative studies of frequency splittings and shifts of the Rb atomic transitions in a wide range of external magnetic fields, from 0.2 up to 6 kG (20-600 mT). We compare the SA spectra obtained with the MTC with those obtained ...

  3. 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.

  4. Determination of barium and strontium by atomic absorption in aqueous solutions with (Sr)/(Ba) ratios ranging from 0. 04 to 15,000

    Energy Technology Data Exchange (ETDEWEB)

    Galinier, C.; Bouhlel, S.; Reynier, B.

    1986-11-01

    The systematic use of atomic absorption allowed the determination of Ba and Sr in aqueous solutions with (Sr)/(Ba) ratios ranging from 0.04 to 15,000. In this study, we define the limits over which the interaction between the matrix and the ion to determine becomes important. For concentration ratios (Sr)/(Ba) lower than 50, the addition of lg of KCl per liter reduces the effect of the matrix to a reasonable value. For an (Sr)/(Ba) ratio above 50, adding an alcaline salt is not sufficient to decrease the interactions. In this case, we propose a diagram to correct the determination of baryum.

  5. Determination of Iron (Fe) and Calcium (Ca) in NIST SRM 1566b (Oyster tissue) using Flame Atomic Absorption Spectrometry (F-AAS) by Standard Addition Method

    OpenAIRE

    Fitri Dara; Y Susanto Ridwan

    2017-01-01

    NIST Standard Reference Material (SRM 1566b) was employed for the determination of Iron (Fe) andCalcium (Ca) as nutrients in food matrix using Flame Atomic Absorption Spectrometry (F-AAS). Thecertified value of SRM 1566b for Fe and Ca are 205.8 ± 6.8 mg/kg and 0.0838 ± 0.0020 (%) or 838 ±20 mg/kg, respectively. This certified values are based on results obtained by single primary method(Isotope Dilution Inductively Couple Plasma Mass Spectrometry) at NIST with confirmation by othermethods at ...

  6. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Fabio Andrei; Bizzi, Cezar Augusto; Goldschmidt Antes, Fabiane; Dressler, Valderi Luiz [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil); Flores, Erico Marlon de Moraes [Departamento de Quimica, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS (Brazil)], E-mail: flores@quimica.ufsm.br

    2009-06-15

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L{sup - 1} KBr in 6 mol L{sup - 1} HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L{sup - 1} HCl and 2.5% m/v NaBH{sub 4} solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 deg. C and the atomization temperature was set at 650 deg. C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g{sup - 1} for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  7. Organic, inorganic and total mercury determination in fish by chemical vapor generation with collection on a gold gauze and electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Duarte, Fábio Andrei; Bizzi, Cezar Augusto; Antes, Fabiane Goldschmidt; Dressler, Valderi Luiz; Flores, Érico Marlon de Moraes

    2009-06-01

    A method for organic, inorganic and total mercury determination in fish tissue has been developed using chemical vapor generation and collection of mercury vapor on a gold gauze inside a graphite tube and further atomization by electrothermal atomic absorption spectrometry. After drying and cryogenic grinding, potassium bromide and hydrochloric acid solution (1 mol L - 1 KBr in 6 mol L - 1 HCl) was added to the samples. After centrifugation, total mercury was determined in the supernatant. Organomercury compounds were selectively extracted from KBr solution using chloroform and the resultant solution was back extracted with 1% m/v L-cysteine. This solution was used for organic Hg determination. Inorganic Hg remaining in KBr solution was directly determined by chemical vapor generation electrothermal atomic absorption spectrometry. Mercury vapor generation from extracts was performed using 1 mol L - 1 HCl and 2.5% m/v NaBH 4 solutions and a batch chemical vapor generation system. Mercury vapor was collected on the gold gauze heated resistively at 80 °C and the atomization temperature was set at 650 °C. The selectivity of extraction was evaluated using liquid chromatography coupled to chemical vapor generation and determination by inductively coupled plasma mass spectrometry. The proposed method was applied for mercury analysis in shark, croaker and tuna fish tissues. Certified reference materials were used to check accuracy and the agreement was better than 95%. The characteristic mass was 60 pg and method limits of detection were 5, 1 and 1 ng g - 1 for organic, inorganic and total mercury, respectively. With the proposed method it was possible to analyze up to 2, 2 and 6 samples per hour for organic, inorganic and total Hg determination, respectively.

  8. Frozen lattice and absorptive model for high angle annular dark field scanning transmission electron microscopy: A comparison study in terms of integrated intensity and atomic column position measurement.

    Science.gov (United States)

    Alania, M; Lobato, I; Van Aert, S

    2018-01-01

    In this paper, both the frozen lattice (FL) and the absorptive potential (AP) approximation models are compared in terms of the integrated intensity and the precision with which atomic columns can be located from an image acquired using high angle annular dark field (HAADF) scanning transmission electron microscopy (STEM). The comparison is made for atoms of Cu, Ag, and Au. The integrated intensity is computed for both an isolated atomic column and an atomic column inside an FCC structure. The precision has been computed using the so-called Cramér-Rao Lower Bound (CRLB), which provides a theoretical lower bound on the variance with which parameters can be estimated. It is shown that the AP model results into accurate measurements for the integrated intensity only for small detector ranges under relatively low angles and for small thicknesses. In terms of the attainable precision, both methods show similar results indicating picometer range precision under realistic experimental conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Mechanical characterization of polymeric thin films by atomic force microscopy based techniques.

    Science.gov (United States)

    Passeri, Daniele; Rossi, Marco; Tamburri, Emanuela; Terranova, Maria Letizia

    2013-02-01

    Polymeric thin films have been awakening continuous and growing interest for application in nanotechnology. For such applications, the assessment of their (nano)mechanical properties is a key issue, since they may dramatically vary between the bulk and the thin film state, even for the same polymer. Therefore, techniques are required for the in situ characterization of mechanical properties of thin films that must be nondestructive or only minimally destructive. Also, they must also be able to probe nanometer-thick ultrathin films and layers and capable of imaging the mechanical properties of the sample with nanometer lateral resolution, since, for instance, at these scales blends or copolymers are not uniform, their phases being separated. Atomic force microscopy (AFM) has been proposed as a tool for the development of a number of techniques that match such requirements. In this review, we describe the state of the art of the main AFM-based methods for qualitative and quantitative single-point measurements and imaging of mechanical properties of polymeric thin films, illustrating their specific merits and limitations.

  10. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1998-01-01

    This volume continues the series'' cutting-edge reviews on developments in this field. Since its invention in the 1920s, electrostatic precipitation has been extensively used in industrial hygiene to remove dust and particulate matter from gases before entering the atmosphere. This combination of electrostatic precipitation is reported upon in the first chapter. Following this, chapter two reviews recent advances in the area of chemical modification in electrothermal atomization. Chapter three consists of a review which deal with advances and uses of electrothermal atomization atomic absorption spectrometry. Flow injection atomic spectroscopy has developed rapidly in recent years and after a general introduction, various aspects of this technique are looked at in chapter four. Finally, in chapter five the use of various spectrometric techniques for the determination of mercury are described.

  11. Comparison of three measurement techniques for the normal absorption coefficient of sound absorbing materials in the free field.

    Science.gov (United States)

    Hirosawa, Kunikazu; Takashima, Kazuhiro; Nakagawa, Hiroshi; Kon, Makoto; Yamamoto, Aki; Lauriks, Walter

    2009-12-01

    Three different techniques for evaluating the absorption coefficient of sound absorbing materials in free field conditions are discussed. One technique measures the acoustic impedance at one point nearby a specimen, the other two techniques evaluate the impedance from the transfer function of two sound pressures and two particle velocities at two points. These are called "PU-method," "PP-method," and "UU-method," respectively. An iterative algorithm to estimate the acoustic impedance of the locally reactive specimen in the spherical wave field is also applied. First, the effect of receiver positions, specimen areas, and source heights to the measured normal absorption coefficient is investigated by the boundary element method. According to these investigations, the PU-method is most stable against the effect of specimen area, and the UU-method is easily affected by that effect. Closer source to the specimen distance is advantageous for the signal to noise ratio of these measurement techniques, but correction for the effect of the spherical wave field has to be applied. As a finding, the iterative algorithm works for all of three techniques. Finally, the PU-method is applied experimentally with a pressure-velocity sensor and a loudspeaker in a hemi-anechoic room. As a result, the calculated results have been verified.

  12. Comparison of serum copper determination by colorimetric and atomic absorption spectrometric methods in seven different laboratories. The S.F.B.C. (Société Française de Biologie Clinique) Trace Element Group.

    Science.gov (United States)

    Arnaud, J; Chappuis, P; Zawislak, R; Houot, O; Jaudon, M C; Bienvenu, F; Bureau, F

    1993-02-01

    An interlaboratory collaborative trial was conducted on the determination of serum copper using two different methods, based on colorimetry (test combination Copper, Boehringer Mannheim, Mannheim, Germany) and flame atomic absorption spectrometry (FAAS). The general performance of the colorimetric method was below that of FAAS, except for sensitivity and linear range, as assessed by detection limit (0.44 versus 1.32 mumol/L) and upper limit of linearity (150 versus 50 mumol/L). The range of the between-run CVs and the recovery of standard additions were, respectively, 2.3-11.9% and 92-127% for the colorimetric method and 1.1-6.0% and 93-101% for the FAAS method. Interferences were minimal with both methods. The two techniques correlated satisfactorily (the correlation coefficients ranged from 0.945-0.970 among laboratories) but the colorimetric assay exhibited slightly higher results than the FAAS method. Each method was transferable among laboratories.

  13. Coupled-cluster response theory for near-edge x-ray-absorption fine structure of atoms and molecules

    DEFF Research Database (Denmark)

    Coriani, Sonia; Christiansen, Ove; Fransson, Thomas

    2012-01-01

    response function, the near K-edge x-ray absorption spectra of neon, water, and carbon monoxide are determined and compared with experiment. Results at the CCSD level show relative peak intensities in good agreement with experiment with discrepancies in transition energies due to incomplete treatment...

  14. 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.

  15. Biopartitioning micellar chromatography: an in vitro technique for predicting human drug absorption.

    Science.gov (United States)

    Molero-Monfort, M; Escuder-Gilabert, L; Villanueva-Camañas, R M; Sagrado, S; Medina-Hernández, M J

    2001-04-05

    The main oral drug absorption barriers are fluid cell membranes and generally drugs are absorbed by a passive diffusion mechanism. Biopartitioning micellar chromatography (BMC) is a mode of micellar liquid chromatography that uses micellar mobile phases of Brij35 under adequate experimental conditions and can be useful to mimic the drug partitioning process in biological systems. In this paper the usefulness of BMC for predicting oral drug absorption in humans is demonstrated. A hyperbolic model has been obtained using the retention data of a heterogeneous set of 74 compounds, which shows predictive ability for drugs absorbed by passive diffusion. The model obtained in BMC is compared with those obtained using the well-known systems (Caco-2 and TC-7) that use intestinal epithelium cell lines. The use of BMC is simple, reproducible and can provide key information about the transport properties of new compounds during the drug discovery process.

  16. Fast heating induced impulse halogenation of refractory sample components in electrothermal atomic absorption spectrometry by direct injection of a liquid halogenating agent.

    Science.gov (United States)

    György, Krisztina; Ajtony, Zsolt; Van Meel, Katleen; Van Grieken, René; Czitrovszky, Aladár; Bencs, László

    2011-09-15

    A novel electrothermal atomic absorption spectrometry (ETAAS) method was developed for the halogenation of refractory sample components (Er, Nd and Nb) of lithium niobate (LiNbO(3)) and bismuth tellurite (Bi(2)TeO(5)) optical single crystals to overcome memory effects and carry-over. For this purpose, the cleaning step of a regular graphite furnace heating program was replaced with a halogenation cycle. In this cycle, after the graphite tube cooled to room temperature, a 20 μL aliquot of liquid carbon tetrachloride (CCl(4)) was dispensed with a conventional autosampler into the graphite tube. The CCl(4) was partially dried at 80°C under the mini-flow (40 cm(3) min(-1)) condition of the Ar internal furnace gas (IFG), then the residue was decomposed (pyrolyzed) by fast furnace heating at 1900-2100°C under interrupted flow of the IFG. This step was followed by a clean-out stage at 2100°C under the maximum flow of the IFG. The advantage of the present method is that it does not require any alteration to the graphite furnace gas supply system in contrast to most of the formerly introduced halogenation techniques. The effectiveness of the halogenation method was verified with the determination of Er and Nd dopants in the optical crystals. In these analyses, a sensitivity decrease was observed, which was likely due to the enhanced deterioration of the graphite tube surface. Therefore, the application of mathematical correction (resloping) of the calibration was also required. The calibration curves were linear up to 1.5 and 10 μmol L(-1) for Er and Nd, respectively. Characteristic masses of 18 and 241 pg and the limit of detection (LOD) values of 0.017 and 0.27 μmol L(-1) were found for Er and Nd, respectively. These LOD data correspond to 0.68 μmol mol(-1) Er and 11 μmol mol(-1) Nd in solid bismuth tellurite samples. The analytical results were compared with those obtained by a conventional ETAAS method and validated with X-ray fluorescence spectrometry analysis

  17. VO2+ ions in zinc lead borate glasses studied by EPR and optical absorption techniques.

    Science.gov (United States)

    Prakash, P Giri; Rao, J Lakshmana

    2005-09-01

    Electron paramagnetic resonance (EPR) and optical absorption spectra of vanadyl ions in zinc lead borate (ZnO-PbO-B2O3) glass system have been studied. EPR spectra of all the glass samples exhibit resonance signals characteristic of VO2+ ions. The values of spin-Hamiltonian parameters indicate that the VO2+ ions in zinc lead borate glasses were present in octahedral sites with tetragonal compression and belong to C4V symmetry. The spin-Hamiltonian parameters g and A are found to be independent of V2O5 content and temperature but changing with ZnO content. The decrease in Deltag( parallel)/Deltag( perpendicular) value with increase in ZnO content indicates that the symmetry around VO2+ ions is more octahedral. The decrease in intensity of EPR signal above 10 mol% of V2O5 is attributed to a fall in the ratio of the number of V4+ ions (N4) to the number of V5+ ions (N5). The number of spins (N) participating in resonance was calculated as a function of temperature for VO2+ doped zinc lead borate glass sample and the activation energy was calculated. From the EPR data, the paramagnetic susceptibility was calculated at various temperatures and the Curie constant was evaluated from the 1/chi-T graph. The optical absorption spectra show single absorption band due to VO2+ ions in tetragonally distorted octahedral sites.

  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. Determination and Uncertainty Analysis of Inorganic Arsenic in Husked Rice by Solid Phase Extraction and Atomic Absorption Spectrometry with Hydride Generation.

    Science.gov (United States)

    Saxena, Sushil Kumar; Karipalli, Agnes Raju; Krishnan, Anoop A; Rangasamy, Rajesh; Malekadi, Praveen; Singh, Dhirendra P; Vasu, Vimesh; Singh, Vijay K

    2017-05-01

    This study enables the selective determination of inorganic arsenic (iAs) with a low detection limit using an economical instrument [atomic absorption spectrometer with hydride generation (HG)] to meet the regulatory requirements as per European Commission (EC) and Codex guidelines. Dry rice samples (0.5 g) were diluted using 0.1 M HNO3-3% H2O2 and heated in a water bath (90 ± 2°C) for 60 min. Through this process, all the iAs is solubilized and oxidized to arsenate [As(V)]. The centrifuged extract was loaded onto a preconditioned and equilibrated strong anion-exchange SPE column (silica-based Strata SAX 500 mg/6 mL), followed by selective and sequential elution of As(V), enabling the selective quantification of iAs using atomic absorption spectrometry with HG. In-house validation showed a mean recovery of 94% and an LOQ of 0.025 mg/kg. The repeatability (HorRatr) and reproducibility (HorRatR) values were determination of iAs in husked rice samples and has potential applications in other food commodities.

  20. Investigating effects of sample pretreatment on protein stability using size-exclusion chromatography and high-resolution continuum source atomic absorption spectrometry.

    Science.gov (United States)

    Rakow, Tobias; El Deeb, Sami; Hahne, Thomas; El-Hady, Deia Abd; AlBishri, Hassan M; Wätzig, Hermann

    2014-09-01

    In this study, size-exclusion chromatography and high-resolution atomic absorption spectrometry methods have been developed and evaluated to test the stability of proteins during sample pretreatment. This especially includes different storage conditions but also adsorption before or even during the chromatographic process. For the development of the size exclusion method, a Biosep S3000 5 μm column was used for investigating a series of representative model proteins, namely bovine serum albumin, ovalbumin, monoclonal immunoglobulin G antibody, and myoglobin. Ambient temperature storage was found to be harmful to all model proteins, whereas short-term storage up to 14 days could be done in an ordinary refrigerator. Freezing the protein solutions was always complicated and had to be evaluated for each protein in the corresponding solvent. To keep the proteins in their native state a gentle freezing temperature should be chosen, hence liquid nitrogen should be avoided. Furthermore, a high-resolution continuum source atomic absorption spectrometry method was developed to observe the adsorption of proteins on container material and chromatographic columns. Adsorption to any container led to a sample loss and lowered the recovery rates. During the pretreatment and high-performance size-exclusion chromatography, adsorption caused sample losses of up to 33%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. 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.

  2. Determination of traces of copper and zinc in honeys by the solid phase extraction pre-concentration followed by the flame atomic absorption spectrometry detection.

    Science.gov (United States)

    Stecka, Helena; Jedryczko, Dominika; Welna, Maja; Pohl, Pawel

    2014-10-01

    A simple and fast solid phase extraction procedure was developed to pre-concentrate traces of Cu and Zn prior to their determination in honey samples by flame atomic absorption spectrometry. The sample preparation included dissolution of honey samples and the passage (at 20 ml/min) of resulting 10% m/v solutions (100 ml) through Dowex 50W × 8-400 resin beds in order to quantitatively retain Cu and Zn and separate them from the glucose and fructose matrix. Enriched Cu and Zn traces were recovered with 5.0 ml of a 3.0 mol/l HCl solution and quantified by flame atomic absorption spectrometry. The procedure proposed was used to analyze sixty nine commercially available and freshly ripened honey samples coming from the Lower Silesia region (Poland). It enabled to measure Cu and Zn within the range of 0.01-1.42 and 0.03-15.38 μg/g, respectively, with precision better than 4%. Accuracy, assessed on the basis of the recovery test and the comparison of results with those obtained using wet digestion and inductively coupled plasma optical emission spectrometry, was ranged from -4% to +6%. Detection limits of Cu and Zn achieved with this method were 5 and 7 ng/g, respectively.

  3. 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.

  4. ATOMIC DATA FOR ABSORPTION-LINES FROM THE GROUND-LEVEL AT WAVELENGTHS GREATER-THAN-228-ANGSTROM

    NARCIS (Netherlands)

    VERNER, DA; BARTHEL, PD; TYTLER, D

    1994-01-01

    We list wavelengths, statistical weigths and oscillator strengths for 2249 spectral lines arising from the ground states of atoms and ions. The compilation covers all wavelengths longward of the HeII Lyman limit at 227.838 Angstrom and all the ion states of all elements from hydrogen to bismuth (Z =

  5. Augmenting the bioactivity of polyetheretherketone using a novel accelerated neutral atom beam technique.

    Science.gov (United States)

    Ajami, S; Coathup, M J; Khoury, J; Blunn, G W

    2017-08-01

    Polyetheretherketone (PEEK) is an alternative to metallic implants in orthopedic applications; however, PEEK is bioinert and does not osteointegrate. In this study, an accelerated neutral atom beam technique (ANAB) was employed to improve the bioactivity of PEEK. The aim was to investigate the growth of human mesenchymal stem cells (hMSCs), human osteoblasts (hOB), and skin fibroblasts (BR3G) on PEEK and ANAB PEEK. The surface roughness and contact angle of PEEK and ANAB PEEK was measured. Cell metabolic activity, proliferation and alkaline phosphatase (ALP) was measured and cell attachment was determined by quantifying adhesion plaques with cells. ANAB treatment increased the surface hydrophilicity [91.74 ± 4.80° (PEEK) vs. 74.82 ± 2.70° (ANAB PEEK), p PEEK compared to PEEK (p PEEK surfaces. MSCs seeded on ANAB PEEK in the presence of osteogenic media, expressed increased levels of ALP compared to untreated PEEK (p PEEK. ANAB treatment may improve the osteointegration of PEEK implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1438-1446, 2017. © 2016 Wiley Periodicals, Inc.

  6. Determination of trace amount of cadmium using dispersive liquid-liquid microextraction-slotted quartz tube-flame atomic absorption spectrometry

    Science.gov (United States)

    Fırat, Merve; Bakırdere, Sezgin; Fındıkoğlu, Maral Selin; Kafa, Emine Betül; Yazıcı, Elif; Yolcu, Melda; Büyükpınar, Çağdaş; Chormey, Dotse Selali; Sel, Sabriye; Turak, Fatma

    2017-03-01

    This study was performed to develop a sensitive analytical method for the determination of cadmium by slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) after dispersive liquid-liquid microextraction (DLLME). The parameters affecting the cadmium complex formation and its extraction output were optimized to obtain high extraction efficiency. These included the pH and amount of the buffer solution, and the concentration of the ligand. The DLLME method was comprehensively optimized based on the type and amount of extraction solvent, dispersive solvent and salt. The type and period of mixing needed for a more effective extraction was also investigated. In order to further improve the sensitivity for the determination of cadmium, the flame atomic absorption spectrometry was fitted with a slotted quartz tube to increase the residence time of cadmium atoms in the pathway of incident light from a hollow cathode lamp. The limits of detection and quantitation (LOD and LOQ) for the FAAS were found to be 42 and 140 μg L- 1, respectively. Under the optimum conditions, LOD and LOQ of the FAAS after DLLME were calculated as 1.3 and 4.4 μg L- 1, respectively. Combining both optimized parameters of the DLLME and SQT-FAAS gave 0.5 and 1.5 μg L- 1 as LOD and LOQ, respectively. Accuracy of the method was also checked using a wastewater certified reference material (EU-L-2), and the result was in good agreement with the certified value.

  7. Validation of a method to quantify chromium, cadmium, manganese, nickel and lead in human whole blood, urine, saliva and hair samples by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Olmedo, P.; Pla, A.; Hernandez, A.F.; Lopez-Guarnido, O.; Rodrigo, L. [Department of Legal Medicine and Toxicology, University of Granada, School of Medicine (Spain); Gil, F., E-mail: fgil@ugr.es [Department of Legal Medicine and Toxicology, University of Granada, School of Medicine (Spain)

    2010-02-05

    For biological monitoring of heavy metal exposure in occupational toxicology, usually whole blood and urine samples are the most widely used and accepted matrix to assess internal xenobiotic exposure. Hair samples and saliva are also of interest in occupational and environmental health surveys but procedures for the determination of metals in saliva and hair are very scarce and to our knowledge there is no validation of a method to quantify Cr, Cd, Mn, Ni and Pb in four different human biological materials (whole blood, urine, saliva and axilary hair) by electrothermal atomization atomic absorption spectrometry (ETAAS). In the present study, quantification methods for the determination of Cr, Cd, Mn, Ni and Pb in whole blood, urine, saliva and axilary hair were validated according to the EU common standards. Pyrolisis and atomization temperatures have been determined. The main parameters evaluated were: detection and quantification limits, linearity range, repeatability, reproducibility, recovery and uncertainty. Accuracy of the methods was tested with the whole blood, urine and hair certified reference materials and recoveries of the spiked samples were acceptable ranged from 96.3 to 107.8%.

  8. Development of a simple method for the determination of lead in lipstick using alkaline solubilization and graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Soares, Aline Rodrigues; Nascentes, Clésia Cristina

    2013-02-15

    A simple method was developed for determining the total lead content in lipstick samples by graphite furnace atomic absorption spectrometry (GFAAS) after treatment with tetramethylammonium hydroxide (TMAH). Multivariate optimization was used to establish the optimal conditions of sample preparation. The graphite furnace heating program was optimized through pyrolysis and atomization curves. An aliquot containing approximately 50mg of the sample was mixed with TMAH and heated in a water bath at 60°C for 60 min. Using Nb as the permanent modifier and Pd as the chemical modifier, the optimal temperatures were 900°C and 1800°C for pyrolysis and atomization, respectively. Under optimum conditions, the working range was from 1.73 to 50.0 μg L(-1), with detection and quantification limits of 0.20 and 0.34 μg g(-1), respectively. The precision was evaluated under conditions of repeatability and intermediate precision and showed standard deviations of 2.37%-4.61% and 4.93%-9.75%, respectively. The % recovery ranged from 96.2% to 109%, and no significant differences were found between the results obtained using the proposed method and the microwave decomposition method for real samples. Lead was detected in 21 tested lipstick samples; the lead content in these samples ranged from 0.27 to 4.54 μg g(-1). Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Measurement of Hydrogen Absorption in Ternary Alloys with Volumetric (Sieverts Loop) Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Aceves, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    The Sieverts loop is an inexpensive, robust and reliable methodology for calculating hydrogen absorption in materials [1]. In this approach, we start by storing a sample of the material being tested in the volume Vcell (Figure 1) and initiate the process by producing a high vacuum in the system while the material sample is heated to eliminate (most of) the hydrogen and other impurities previously absorbed. The system typically operates isothermally, with the volume Vref at ambient temperature and the sample at a temperature of interest – high enough to liquefy the alloy for the current application to nuclear fusion.

  10. Rapid determination of lead and cadmium in sewage sludge samples using electrothermal atomic absorption spectrometry with slurry sample introduction

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Garcia, I.; Vinas, P.; Arroyo-Cortez, J.; Hernandez-Cordoba, M. [Dept. of Analytical Chem., Univ. of Murcia (Spain)

    2000-08-01

    Lead and cadmium concentrations in sewage sludge samples are determined by suspending the ground samples in a solution containing 10% (v/v) concentrated hydrofluoric acid, 1% (v/v) concentrated nitric acid, 0.5% (m/v) dihydrogen ammonium phosphate and 0.1% (m/v) sodium hexametaphosphate. Aliquots of 20 {mu}L of these suspensions (4 mg/mL) are diluted to 1000 {mu}L with the same solution and then injected into the electrothermal atomizer. The drying stage is performed by programming a 400 C temperature, a ramp time of 20 s and a hold time of 15 s on the power supply of the atomizer. No ashing step is used. Platform atomization is carried out at 1600 and 1800 C for Pb and Cd, respectively. Calibration is performed using aqueous standards in the 5-75 and 0.2- 5 {mu}g/L Pb and Cd ranges, respectively. Results obtained for three certified reference materials and four samples demonstrate the reliability of the procedures described. (orig.)

  11. Infrared absorption spectroscopy of carbon monoxide on nickel films: a low temperature thermal detection technique

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, R.B.

    1978-11-01

    Sensitive vibrational spectra of carbon monoxide molecules adsorbed on evaporated nickel films have been measured by attaching a thermometer to the sample, cooling the assembly to liquid helium temperatures, and recording the temperature changes which occur when infrared radiation is absorbed. The measurements are made in an ultrahigh vacuum chamber in which the sample surface can be cleaned, heated, exposed to gas molecules and cooled to 1.6 K for the infrared measurements. The spectra of chemisorbed CO molecules are interpreted in terms of the linear and bridge adsorption sites on the nickel surface, and they show how the distribution of molecules among these sites changes when the CO coverage increases and intermolecular forces become important. The spectra of physically adsorbed molecules in both monolayer and multilayer films are also reported. Absorptions as small as five parts in 10/sup 5/ of the incident radiation can presently be detected in spectra covering broad bands of infrared frequencies with a resolution of 2 cm/sup -1/. This high sensitivity is attributable to the low noise and reduced background signal of the thermal detection scheme, to the stability of the rapid scan Fourier transform infrared spectrometer, and to the automated computerized data acquisition electronics. Better performance is expected in future experiments on single crystal samples as well as evaporated films. This will make it possible to study molecules with weaker absorptions than CO and to look for evidence of chemical reactions between different adsorbed molecules.

  12. Characterization of magnetic materials by low-field microwave absorption techniques

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, R. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico)], E-mail: monjaras@servidor.unam.mx; Alvarez, G. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico); Montiel, H. [Departamento de Tecnociencias, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Gutierrez, M.P. [Departamento de Quimica Inorganica y Nuclear, Facultad de Quimica, Universidad Nacional Autonoma de Mexico (Mexico); Mata-Zamora, M.E. [Departamento de Tecnociencias, Centro de Ciencias Aplicadas y Desarrollo Tecnologico, Universidad Nacional Autonoma de Mexico (Mexico); Barron, F.; Sanchez, A.Y.; Betancourt, I. [Departamento de Materiales Metalicos y Ceramicos, Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico (Mexico); Zamorano, R. [Departamento de Ciencia de Materiales, Instituto Politecnico Nacional (Mexico)

    2008-07-15

    A low-field non-resonant microwave absorption has recently been observed in a variety of magnetically ordered materials at low DC fields (-1000 Oe {<=}H{sub DC}{<=}+1000 Oe), which is known as low-field microwave absorption (LFA). It has been shown that LFA is essentially similar to giant magnetoimpedance (GMI), and clearly different from ferromagnetic resonance (FMR). LFA strongly depends on the anisotropy field of the sample. In contrast with FMR (which can be described as the homogeneous precession of spins in the saturated state), LFA can be thought as a spin rotation process occurring during the magnetic saturation. In this work, we present a detailed study of the basic features of LFA in several types of materials: ferrites and amorphous microwires and ribbons; in particular the effects sample shape, temperature up to the Curie transition, the influence of easy axis and the effects of annealings. These examples show that once LFA is fully understood, it can become a powerful characterization tool.

  13. Validation of phenol red versus gravimetric method for water reabsorption correction and study of gender differences in Doluisio's absorption technique.

    Science.gov (United States)

    Tuğcu-Demiröz, Fatmanur; Gonzalez-Alvarez, Isabel; Gonzalez-Alvarez, Marta; Bermejo, Marival

    2014-10-01

    The aim of the present study was to develop a method for water flux reabsorption measurement in Doluisio's Perfusion Technique based on the use of phenol red as a non-absorbable marker and to validate it by comparison with gravimetric procedure. The compounds selected for the study were metoprolol, atenolol, cimetidine and cefadroxil in order to include low, intermediate and high permeability drugs absorbed by passive diffusion and by carrier mediated mechanism. The intestinal permeabilities (Peff) of the drugs were obtained in male and female Wistar rats and calculated using both methods of water flux correction. The absorption rate coefficients of all the assayed compounds did not show statistically significant differences between male and female rats consequently all the individual values were combined to compare between reabsorption methods. The absorption rate coefficients and permeability values did not show statistically significant differences between the two strategies of concentration correction. The apparent zero order water absorption coefficients were also similar in both correction procedures. In conclusion gravimetric and phenol red method for water reabsorption correction are accurate and interchangeable for permeability estimation in closed loop perfusion method. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Quantum cascade laser absorption spectroscopy with the amplitude-to-time conversion technique for atmospheric-pressure plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Yumii, Takayoshi; Kimura, Noriaki [Mitsui Engineering and Shipbuilding Co., Ltd., Tamahara 3-16-1, Tamano, Okayama 706-0014 (Japan); Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan); Hamaguchi, Satoshi [Graduate School of Engineering, Osaka University, Yamadaoka 2-1, Suita, Osaka 565-0871 (Japan)

    2013-06-07

    The NO{sub 2} concentration, i.e., density, in a small plasma of a nitrogen oxide (NOx) treatment reactor has been measured by highly sensitive laser absorption spectroscopy. The absorption spectroscopy uses a single path of a quantum cascade laser beam passing through a plasma whose dimension is about 1 cm. The high sensitivity of spectroscopy is achieved by the amplitude-to-time conversion technique. Although the plasma reactor is designed to convert NO in the input gas to NO{sub 2}, it has been demonstrated by this highly sensitive absorption spectroscopy that NO{sub 2} in a simulated exhaust gas that enters the reactor is decomposed by the plasma first and then NO{sub 2} is formed again, possibly more than it was decomposed, through a series of gas-phase reactions by the time the gas exits the reactor. The observation is consistent with that of an earlier study on NO decomposition by the same type of a plasma reactor [T. Yumii et al., J. Phys. D 46, 135202 (2013)], in which a high concentration of NO{sub 2} was observed at the exit of the reactor.

  15. Cold vapor-solid phase microextraction using amalgamation in different Pd-based substrates combined with direct thermal desorption in a modified absorption cell for the determination of Hg by atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vanesa; Costas-Mora, Isabel; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

    2011-02-15

    In this work, different Pd-based substrates (i.e. Pd wire, Pd-coated stainless steel wire and Pd-coated SiO{sub 2}) are tried for microextraction of Hg prior to its release into a modified quartz T-cell so as to develop a cost-effective, sensitive and easy-to-handle coupling between solid-phase microextraction (SPME) and atomic absorption spectrometry. The new design allows a direct sample injection from the SPME device into a quartz T-cell thus avoiding analyte dilution. Mercury amalgamation onto a Pd wire provided the best performance in respect to sensitivity and fiber lifetime, but Pd wires could not be implemented in the SPME device due to their poor mechanical characteristics. On the contrary, Pd-coated SiO{sub 2} fibers could be easily adapted to the typical sampling device used for SPME. Narrow time-dependent absorption signal profiles that could be integrated within 25 s were obtained. The detection limit was 90 pg mL{sup -1} of Hg, and the repeatability expressed as relative standard deviation was 4.3%.

  16. Preferential growth of ZnO thin films by the atomic layer deposition technique

    Science.gov (United States)

    Pung, Swee-Yong; Choy, Kwang-Leong; Hou, Xianghui; Shan, Chongxin

    2008-10-01

    Preferred orientation of ZnO thin films deposited by the atomic layer deposition (ALD) technique could be manipulated by deposition temperature. In this work, diethyl zinc (DEZn) and deionized water (H2O) were used as a zinc source and oxygen source, respectively. The results demonstrated that (10.0) dominant ZnO thin films were grown in the temperature range of 155-220 °C. The c-axis crystal growth of these films was greatly suppressed. Adhesion of anions (such as fragments of an ethyl group) on the (00.2) polar surface of the ZnO thin film was believed to be responsible for this suppression. In contrast, (00.2) dominant ZnO thin films were obtained between 220 and 300 °C. The preferred orientations of (10.0) and (00.2) of the ZnO thin films were examined by XRD texture analysis. The texture analysis results agreed well with the alignments of ZnO nanowires (NWs) which were grown from these ZnO thin films. In this case, the nanosized crystals of ZnO thin films acted as seeds for the growth of ZnO nanowires (NWs) by chemical vapor deposition (CVD) process. The highly (00.2) textured ZnO thin films deposited at high temperatures, such as 280 °C, contained polycrystals with the c axis perpendicular to the substrate surface and provided a good template for the growth of vertically aligned ZnO NWs.

  17. 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.

  18. Pre-Saturation Technique of the Recycled Aggregates: Solution to the Water Absorption Drawback in the Recycled Concrete Manufacture

    Directory of Open Access Journals (Sweden)

    Julia García-González

    2014-09-01

    Full Text Available The replacement of natural aggregates by recycled aggregates in the concrete manufacturing has been spreading worldwide as a recycling method to counteract the large amount of construction and demolition waste. Although legislation in this field is still not well developed, many investigations demonstrate the possibilities of success of this trend given that concrete with satisfactory mechanical and durability properties could be achieved. However, recycled aggregates present a low quality compared to natural aggregates, the water absorption being their main drawback. When used untreated in concrete mix, the recycled aggregate absorb part of the water initially calculated for the cement hydration, which will adversely affect some characteristics of the recycled concrete. This article seeks to demonstrate that the technique of pre-saturation is able to solve the aforementioned problem. In order to do so, the water absorption of the aggregates was tested to determine the necessary period of soaking to bring the recycled aggregates into a state of suitable humidity for their incorporation into the mixture. Moreover, several concrete mixes were made with different replacement percentages of natural aggregate and various periods of pre-saturation. The consistency and compressive strength of the concrete mixes were tested to verify the feasibility of the proposed technique.

  19. One-step fabrication of submicrostructures by low one-photon absorption direct laser writing technique with local thermal effect

    Science.gov (United States)

    Nguyen, Dam Thuy Trang; Tong, Quang Cong; Ledoux-Rak, Isabelle; Lai, Ngoc Diep

    2016-01-01

    In this work, local thermal effect induced by a continuous-wave laser has been investigated and exploited to optimize the low one-photon absorption (LOPA) direct laser writing (DLW) technique for fabrication of polymer-based microstructures. It was demonstrated that the temperature of excited SU8 photoresist at the focusing area increases to above 100 °C due to high excitation intensity and becomes stable at that temperature thanks to the use of a continuous-wave laser at 532 nm-wavelength. This optically induced thermal effect immediately completes the crosslinking process at the photopolymerized region, allowing obtain desired structures without using the conventional post-exposure bake (PEB) step, which is usually realized after the exposure. Theoretical calculation of the temperature distribution induced by local optical excitation using finite element method confirmed the experimental results. LOPA-based DLW technique combined with optically induced thermal effect (local PEB) shows great advantages over the traditional PEB, such as simple, short fabrication time, high resolution. In particular, it allowed the overcoming of the accumulation effect inherently existed in optical lithography by one-photon absorption process, resulting in small and uniform structures with very short lattice constant.

  20. Pre-Saturation Technique of the Recycled Aggregates: Solution to the Water Absorption Drawback in the Recycled Concrete Manufacture †

    Science.gov (United States)

    García-González, Julia; Rodríguez-Robles, Desirée; Juan-Valdés, Andrés; Morán-del Pozo, Julia Mª; Guerra-Romero, M. Ignacio

    2014-01-01

    The replacement of natural aggregates by recycled aggregates in the concrete manufacturing has been spreading worldwide as a recycling method to counteract the large amount of construction and demolition waste. Although legislation in this field is still not well developed, many investigations demonstrate the possibilities of success of this trend given that concrete with satisfactory mechanical and durability properties could be achieved. However, recycled aggregates present a low quality compared to natural aggregates, the water absorption being their main drawback. When used untreated in concrete mix, the recycled aggregate absorb part of the water initially calculated for the cement hydration, which will adversely affect some characteristics of the recycled concrete. This article seeks to demonstrate that the technique of pre-saturation is able to solve the aforementioned problem. In order to do so, the water absorption of the aggregates was tested to determine the necessary period of soaking to bring the recycled aggregates into a state of suitable humidity for their incorporation into the mixture. Moreover, several concrete mixes were made with different replacement percentages of natural aggregate and various periods of pre-saturation. The consistency and compressive strength of the concrete mixes were tested to verify the feasibility of the proposed technique. PMID:28788188