Atomic fluorescence spectrometry with the inductively coupled plasma

International Nuclear Information System (INIS)

Omenetto, N.; Winefordner, J.D.

1987-01-01

Atomic fluorescence spectrometry (AFS) is based on the radiational activation of atoms and ions produced in a suitable atomizer (ionizer) and the subsequent measurement of the resulting radiational deactivation, called fluorescence. Atomic fluorescence spectrometry has been of considerable interest to researchers in atomic spectrometry because of its use for both analytical and diagnostic purposes. Unfortunately, the analytical applications of AFS have suffered from the lack of commercial instrumentation until the recent marketing of the Baird multiple-element, hollow cathode lamp-excited inductively coupled plasma system. This chapter is concerned strictly with the use of the inductively coupled plasma (ICP) as a cell and as a source for AFS. Many of the major references concerning the ICP in analytical AFS are categorized in Table 9.1, along with several reviews and diagnostical studies. For more detailed discussions of the fundamental aspects of AFS, the reader is referred to previous reviews

Numerical simulation study for atomic-resolution x-ray fluorescence holography

International Nuclear Information System (INIS)

Xie Honglan; Gao Hongyi; Chen Jianwen; Xiong Shisheng; Xu Zhizhan; Wang Junyue; Zhu Peiping; Xian Dingchang

2003-01-01

Based on the principle of x-ray fluorescence holography, an iron single crystal model of a body-centred cubic lattice is numerically simulated. From the fluorescence hologram produced numerically, the Fe atomic images were reconstructed. The atomic images of the (001), (100), (010) crystallographic planes were consistent with the corresponding atomic positions of the model. The result indicates that one can obtain internal structure images of single crystals at atomic-resolution by using x-ray fluorescence holography

Imaging atoms from resonance fluorescence spectrum beyond the diffraction limit

Science.gov (United States)

Liao, Zeyang; Al-Amri, Mohammad; Zubairy, M. Suhail

2014-03-01

We calculate the resonance fluorescence spectrum of a linear chain of two-level atoms driven by a gradient coherent laser field. The result shows that we can determine the positions of atoms from the spectrum even when the atoms locate within subwavelength range and the dipole-dipole interaction is significant. This far-field resonance fluorescence localization microscopy method does not require point-by-point scanning and it may be more time-efficient. We also give a possible scheme to extract the position information in an extended region without requiring more peak power of laser. We also briefly discuss how to do a 2D imaging based on our scheme. This work is supported by grants from the King Abdulaziz City for Science and Technology (KACST) and the Qatar National Research Fund (QNRF) under the NPRP project.

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

NARCIS (Netherlands)

Marinov, D.; Drag, C.; Blondel, C.; Guaitella, O.; Golda, J.; Klarenaar, B.L.M.; Engeln, R.A.H.; Schulz-von der Gathen, V.; Booth, J.-P.

2016-01-01

Atomic oxygen, considered to be a determining reactant in plasma applications at ambient pressure, is routinely detected by two-photon absorption laser induced fluorescence (TALIF). Here, pressure broadening of the (2p 4 3 P 2  →  3p 3 P J=0,1,2) two-photon transition in oxygen atoms was

Single-atom-resolved fluorescence imaging of an atomic Mott insulator

DEFF Research Database (Denmark)

Sherson, Jacob; Weitenberg, Christof; Andres, Manuel

2010-01-01

in situ images of a quantum fluid in which each underlying quantum particle is detected. Here we report fluorescence imaging of strongly interacting bosonic Mott insulators in an optical lattice with single-atom and single-site resolution. From our images, we fully reconstruct the atom distribution...

Flame emission, atomic absorption and fluorescence spectrometry

International Nuclear Information System (INIS)

Horlick, G.

1980-01-01

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

[Atomic/ionic fluorescence in microwave plasma torch discharge with excitation of high current and microsecond pulsed hollow cathode lamp: Ca atomic/ionic fluorescence spectrometry].

Science.gov (United States)

Gong, Zhen-bin; Liang, Feng; Yang, Peng-yuan; Jin, Qin-han; Huang, Ben-li

2002-02-01

A system of atomic and ionic fluorescence spectrometry in microwave plasma torch (MPT) discharge excited by high current microsecond pulsed hollow cathode lamp (HCMP HCL) has been developed. The operation conditions for Ca atomic and ionic fluorescence spectrometry have been optimized. Compared with atomic fluorescence spectrometry (AFS) in argon microwave induced plasma (MIP) and MPT with the excitation of direct current and conventional pulsed HCL, the system with HCMP HCL excitation can improve AFS and ionic fluorescence spectrometry (IFS) detection limits in MPT atomizer and ionizer. Detection limits (3 sigma) with HCMP HCL-MPT-AFS/IFS are 10.1 ng.mL-1 for Ca I 422.7 nm, 14.6 ng.mL-1 for Ca II 393.4 nm, and 37.4 ng.mL-1 for Ca II 396.8 nm, respectively.

Radio-isotopic apparatus for analyzing low atomic number elements by fluorescence

International Nuclear Information System (INIS)

Robert, Andre; Martinelli, Pierre; Daniel, Georges; Laflotte, Jean-Luc

1969-10-01

An apparatus is described for analyzing light elements of atomic number between 6 and 24 by X-fluorescence. The samples are excited by means of X or α isotopic sources. Various examples of analytical determinations are given. (author) [fr

Laser-induced fluorescence of se, as, and sb in an electrothermal atomizer.

Science.gov (United States)

Swart, D J; Ezer, M; Pacquette, H L; Simeonsson, J B

1998-04-01

Trace detection of Se, As, and Sb atoms has been performed by electrothermal atomization laser-induced fluorescence (ETA-LIF) approaches. Production of far-UV radiation necessary for excitation of As atoms at 193.696 nm and Se atoms at 196.026 nm was accomplished by stimulated Raman shifting (SRS) of the output of a frequency-doubled dye laser operating near 230 nm. Both wavelengths were obtained as second-order anti-Stokes shifts of the dye laser radiation and provided up to 10 μJ/pulse, which was shown through power dependence studies to be sufficient for saturation in the ETA. An excited-state direct line fluorescence approach using excitation at 206.279 nm was also investigated for the LIF detection of Se. High-sensitivity LIF of Sb atoms was accomplished using 206.833-nm excitation and detection at 259.805 nm. The accuracy of the ETA-LIF approaches was demonstrated by determining the As and Se content of aqueous reference samples. The limits of detection (absolute mass) were 200 fg by ground-state LIF and 150 fg by excited-state direct line fluorescence for Se, 200 fg for As, and 10 fg for Sb; these LODs compare favorably with results reported previously in the literature for ETA-LIF, GFAAS, and ICP-MS methods.

Studying atomic-resolution by X-ray fluorescence holography

International Nuclear Information System (INIS)

Gao Hongyi; Chen Jianwen; Xie Honglan; Zhu Huafeng; Li Ruxin; Xu Zhizhan

2005-01-01

In this work, the results of numerical simulations of X-ray fluorescence holograms and the reconstructed atomic images for Fe single crystal are given. The influences of the recording angles ranges and the polarization effect on the reconstruction of the atomic images are discussed. The process for removing twin images by multiple energy fluorescence holography and expanding the energy range of the incident X-rays to improve the resolution of the reconstructed images is presented

Resonance Fluorescence from an Artificial Atom in Squeezed Vacuum

Directory of Open Access Journals (Sweden)

D. M. Toyli

2016-07-01

Full Text Available We present an experimental realization of resonance fluorescence in squeezed vacuum. We strongly couple microwave-frequency squeezed light to a superconducting artificial atom and detect the resulting fluorescence with high resolution enabled by a broadband traveling-wave parametric amplifier. We investigate the fluorescence spectra in the weak and strong driving regimes, observing up to 3.1 dB of reduction of the fluorescence linewidth below the ordinary vacuum level and a dramatic dependence of the Mollow triplet spectrum on the relative phase of the driving and squeezed vacuum fields. Our results are in excellent agreement with predictions for spectra produced by a two-level atom in squeezed vacuum [Phys. Rev. Lett. 58, 2539 (1987], demonstrating that resonance fluorescence offers a resource-efficient means to characterize squeezing in cryogenic environments.

Determination of Te in soldering tin using continuous flowing electrochemical hydride generation atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Jiang Xianjuan; Gan Wuer; Han Suping; He Youzhao

2008-01-01

An electrochemical hydride generation system was developed for the detection of Te by coupling an electrochemical hydride generator with atomic fluorescence spectrometry. Since TeH 2 is unstable and easily decomposes in solution, a reticular W filament cathode was used in the present system. The TeH 2 generated on the cathode surface was effectively driven out by sweeping gas from the cathode chamber. In addition, a low temperature electrochemical cell (10 deg. C) was applied to reduce the decomposition of TeH 2 in solution. The limit of detection (LOD) was 2.2 ng ml -1 and the relative standard deviation (RSD) was 3.9% for nine consecutive measurements of standard solution. This method was successfully employed for determination of Te in soldering tin material

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

International Nuclear Information System (INIS)

Marschner, Karel; Musil, Stanislav; Dědina, Jiří

2015-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2015-07-01

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

Resonance fluorescence from an atom in a squeezed vacuum

Science.gov (United States)

Carmichael, H. J.; Lane, A. S.; Walls, D. F.

1987-06-01

The fluorescent spectrum for a two-level atom which is damped by a squeezed vacuum shows striking differences from the spectrum for ordinary resonance fluorescence. For strong coherent driving fields the Mollow triplet depends on the relative phase of the driving field and the squeezed vacuum field. The central peak may have either subnatural linewidth or supernatural linewidth depending on this phase. The mean atomic polarization also shows a phase sensitivity.

Development of laser excited atomic fluorescence and ionization methods

International Nuclear Information System (INIS)

Winefordner, J.D.

1991-01-01

Progress report: May 1, 1988 to December 31, 1991. The research supported by DE-FG05-88ER13881 during the past (nearly) 3 years can be divided into the following four categories: (1) theoretical considerations of the ultimate detection powers of laser fluorescence and laser ionization methods; (2) experimental evaluation of laser excited atomic fluorescence; (3) fundamental studies of atomic and molecular parameters in flames and plasmas; (4) other studies

An on-line system using ion-imprinted polymer for preconcentration and determination of bismuth in seawater employing atomic fluorescence spectrometry.

Science.gov (United States)

Felix, Caio S A; Silva, Darllen G; Andrade, Heloysa M C; Riatto, Valeria B; Victor, Mauricio M; Ferreira, Sergio L C

2018-07-01

This work proposes an on-line preconcentration system using ion-imprinted polymer (IIP) for determination of bismuth in seawater employing atomic fluorescence spectrometry (AFS). The polymer was synthesized using 2- (5-bromo-2-pyridylazo) -5-diethylaminophenol (Br-PADAP) for complex formation, ethylene glycol dimethacrylate (EGDMA), cross-linking reagent and methacrylic acid (AMA) reagents, used as the functional monomer, 2,2-azobisisobutyronitrile was used as the radical initiator. The polymer was characterized employing the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The determination of bismuth was performed employing hydride generation atomic fluorescence spectrometry (HG AFS) and the experimental conditions were optimized using a Box Behnken design involving the factors sample pH, eluent concentration and sodium tetrahydroborate concentration. So, using the optimized conditions the system allows the determination of bismuth with limits of detection and quantification of 26 and 88 ng L -1 , a preconcentration factor of 19.8. All these parameters were determined using a sample volume of 25 mL. The precision expressed as relative standard deviation (RSD%) was 3.7% for a bismuth(III) solution of concentration 0.25 µg L -1 . The system proposed was applied for the determination of bismuth in four seawater samples collected in Salvador City, Bahia State, Brazil. The concentrations obtained varied from 0.38 to 0.45 μg L -1 . The accuracy was evaluated by addition/recovery test, and the recoveries found varied from 92% to 101%. Copyright © 2018 Elsevier B.V. All rights reserved.

Continuous flow hydride generation-atomic fluorescence spectrometric determination and speciation of arsenic in wine

Energy Technology Data Exchange (ETDEWEB)

Karadjova, Irina B. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria); Lampugnani, Leonardo [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy)]. E-mail: lampugnani@ipcf.cnr.it; Onor, Massimo [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy); D' Ulivo, Alessandro [C.N.R. Istituto per i processi chimico-fisici, Area della Ricerca di Pisa, Via Moruzzi 1, 56124 Pisa (Italy); Tsalev, Dimiter L. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria)

2005-07-15

Methods for the atomic fluorescence spectrometric (AFS) determination of total arsenic and arsenic species in wines based on continuous flow hydride generation (HG) with atomization in miniature diffusion flame (MDF) are described. For hydride-forming arsenic, L-cysteine is used as reagent for pre-reduction and complexation of arsenite, arsenate, monomethylarsonate and dimethylarsinate. Concentrations of hydrochloric acid and tetrahydroborate are optimized in order to minimize interference by ethanol. Procedure permits determination of the sum of these four species in 5-10-fold diluted samples with limit of detection (LOD) 0.3 and 0.6 {mu}g l{sup -1} As in white and red wines, respectively, with precision between 2% and 8% RSD at As levels within 0.5-10 {mu}g l{sup -1}. Selective arsine generation from different reaction media is used for non-chromatographic determination of arsenic species in wines: citrate buffer at pH 5.1 for As(III); 0.2 mol l{sup -1} acetic acid for arsenite + dimethylarsinate (DMA); 8 mol l{sup -1} HCl for total inorganic arsenic [As(III) + As(V)]; and monomethylarsonate (MMA) calculated by difference. Calibration with aqueous and ethanol-matched standard solutions of As(III) is used for 10- and 5-fold diluted samples, respectively. The LODs are 0.4 {mu}g l{sup -1} for As(III) and 0.3 {mu}g l{sup -1} for the other three As species and precision is within 4-8% RSDs. Arsenic species in wine were also determined by coupling of ion chromatographic separation on an anion exchange column and HG-flame AFS detection. Methods were validated by means of recovery studies and comparative analyses by HG-AFS and electrothermal atomic absorption spectrometry after microwave digestion. The LODs were 0.12, 0.27, 0.15 and 0.13 {mu}g l{sup -1} (as As) and RSDs were 2-6%, 5-9%, 3-7% and 2-5% for As(III), As(V), MMA and DMA arsenic species, respectively. Bottled red and white wines from Bulgaria, Republic of Macedonia and Italy were analyzed by non

Continuous flow hydride generation-atomic fluorescence spectrometric determination and speciation of arsenic in wine

International Nuclear Information System (INIS)

Karadjova, Irina B.; Lampugnani, Leonardo; Onor, Massimo; D'Ulivo, Alessandro; Tsalev, Dimiter L.

2005-01-01

Methods for the atomic fluorescence spectrometric (AFS) determination of total arsenic and arsenic species in wines based on continuous flow hydride generation (HG) with atomization in miniature diffusion flame (MDF) are described. For hydride-forming arsenic, L-cysteine is used as reagent for pre-reduction and complexation of arsenite, arsenate, monomethylarsonate and dimethylarsinate. Concentrations of hydrochloric acid and tetrahydroborate are optimized in order to minimize interference by ethanol. Procedure permits determination of the sum of these four species in 5-10-fold diluted samples with limit of detection (LOD) 0.3 and 0.6 μg l -1 As in white and red wines, respectively, with precision between 2% and 8% RSD at As levels within 0.5-10 μg l -1 . Selective arsine generation from different reaction media is used for non-chromatographic determination of arsenic species in wines: citrate buffer at pH 5.1 for As(III); 0.2 mol l -1 acetic acid for arsenite + dimethylarsinate (DMA); 8 mol l -1 HCl for total inorganic arsenic [As(III) + As(V)]; and monomethylarsonate (MMA) calculated by difference. Calibration with aqueous and ethanol-matched standard solutions of As(III) is used for 10- and 5-fold diluted samples, respectively. The LODs are 0.4 μg l -1 for As(III) and 0.3 μg l -1 for the other three As species and precision is within 4-8% RSDs. Arsenic species in wine were also determined by coupling of ion chromatographic separation on an anion exchange column and HG-flame AFS detection. Methods were validated by means of recovery studies and comparative analyses by HG-AFS and electrothermal atomic absorption spectrometry after microwave digestion. The LODs were 0.12, 0.27, 0.15 and 0.13 μg l -1 (as As) and RSDs were 2-6%, 5-9%, 3-7% and 2-5% for As(III), As(V), MMA and DMA arsenic species, respectively. Bottled red and white wines from Bulgaria, Republic of Macedonia and Italy were analyzed by non-chromatographic and chromatographic procedures and the As

Laser-induced fluorescence line narrowing in atomic vapors

International Nuclear Information System (INIS)

Meier, T.; Schuessler, H.A.

1983-01-01

The use of highly monochromatic light allows the selective excitation of atoms in vapors if excitation and detection of the fluorescence is carried out collinearly. The atoms capable of absorbing light then form an atomic beam of well defined velocity along the direction of the laser beam, but no velocity selection occurs perpendicular to it. The potential of the technique for Doppler-free atomic spectroscopy and for the study of excited atom collisions is demonstrated using the Na D 1 line as an example

TRACE ANALYSIS BY LASER-EXCITED ATOMIC FLUORESCENCE WITH ATOMIZATION IN A PULSED PLASMA

OpenAIRE

Lunyov , O.; Oshemkov , S.; Petrov , A.

1991-01-01

The possibilities of plasma atomization for laser fluorescence trace analysis are discussed. Pulsed hot hollow cathode discharge was used for analysis of solutions and powdered samples. The high voltage spark and laser-induced breakdown (laser spark) were used as atomizers of metal-containing atmospheric aerosols. Detection limits were improved by means of temporal background selection.

Resonance fluorescence based two- and three-dimensional atom localization

Science.gov (United States)

Wahab, Abdul; Rahmatullah; Qamar, Sajid

2016-06-01

Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

Two-photon-excited fluorescence spectroscopy of atomic fluorine at 170 nm

Science.gov (United States)

Herring, G. C.; Dyer, Mark J.; Jusinski, Leonard E.; Bischel, William K.

1988-01-01

Two-photon-excited fluorescence spectroscopy of atomic fluorine is reported. A doubled dye laser at 286-nm is Raman shifted in H2 to 170 nm (sixth anti-Stokes order) to excite ground-state 2P(0)J fluorine atoms to the 2D(0)J level. The fluorine atoms are detected by one of two methods: observing the fluorescence decay to the 2PJ level or observing F(+) production through the absorption of an additional photon by the excited atoms. Relative two-photon absorption cross sections to and the radiative lifetimes of the 2D(0)J states are measured.

Determination of total and inorganic mercury in fish samples with on-line oxidation coupled to atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Shao Lijun; Gan Wuer; Su Qingde

2006-01-01

An atomic fluorescence spectrometry system for determination of total and inorganic mercury with electromagnetic induction-assisted heating on-line oxidation has been developed. Potassium peroxodisulphate was used as the oxidizing agent to decompose organomercury compounds. Depending on the temperature selected, inorganic or total mercury could be determined with the same manifold. Special accent was put on the study of the parameters influencing the on-line digestion efficiency. The tolerance to the interference of coexisting ions was carefully examined in this system. Under optimal conditions, the detection limits (3σ) were evaluated to be 2.9 ng l -1 for inorganic mercury and 2.6 ng l -1 for total mercury, respectively. The relative standard deviations for 10 replicate determinations of 1.0 μg l -1 Hg were 2.4 and 3.2% for inorganic mercury and total mercury, respectively. The proposed method was successfully applied to the determination of total and inorganic mercury in fish samples

Atomization of volatile compounds for atomic absorption and atomic fluorescence spectrometry: On the way towards the ideal atomizer

International Nuclear Information System (INIS)

Dedina, Jiri

2007-01-01

This review summarizes and discusses the individual atomizers of volatile compounds. A set of criteria important for analytical praxis is used to rank all the currently existing approaches to the atomization based on on-line atomization for atomic absorption (AAS) and atomic fluorescence spectrometry (AFS) as well as on in-atomizer trapping for AAS. Regarding on-line atomization for AAS, conventional quartz tubes are currently the most commonly used devices. They provide high sensitivity and low baseline noise. Running and investment costs are low. The most serious disadvantage is the poor resistance against atomization interferences and often unsatisfactory linearity of calibration graphs. Miniature diffusion flame (MDF) is extremely resistant to interferences, simple, cheap and user-friendly. Its essential disadvantage is low sensitivity. A novel device, known as a multiatomizer, was designed to overcome disadvantages of previous atomizers. It matches performance of conventional quartz tubes in terms of sensitivity and baseline noise as well as in running and investment costs. The multiatomizer, however, provides much better (i) resistance against atomization interferences and (ii) linearity of calibration graphs. In-atomizer trapping enhances the sensitivity of the determination and eliminates the effect of the generation kinetics and of surges in gas flow on the signal shape. This is beneficial for the accuracy of the determination. It could also be an effective tool for reducing some interferences in the liquid phase. In-situ trapping in graphite furnaces (GF) is presently by far the most popular approach to the in-atomizer trapping. Its resistance against interferences is reasonably good and it can be easily automated. In-situ trapping in GF is a mature method well established in various application fields. These are the reasons to rank in-situ trapping in GF as currently the most convenient approach to hydride atomization for AAS. The recently suggested

Sensitized fluorescence in thallium induced in collisions with Hg(6/sup 3/P/sub 1/) atoms

Energy Technology Data Exchange (ETDEWEB)

Wade, M K; Czajkowski, M; Krause, L [Windsor Univ., Ontario (Canada). Dept. of Physics

1978-07-01

The transfer of excitation from excited mercury atoms to ground-state thallium atoms was investigated using techniques of sensitized fluorescence. A Hg-Tl vapor mixture contained in a quartz cell was irradiated with Hg 2537 A resonance radiation which caused the mercury atoms to become excited to the 6/sup 3/P/sub 1/ state. Subsequent collisions between the Hg(6/sup 3/P/sub 1/) and Tl(6/sup 2/Psub(1/2)) atoms resulted in the population of the 8/sup 2/Ssub(1/2), 6/sup 2/D, and 7/sup 2/Ssub(1/2) thallium states, whose decay gave rise to sensitized fluorescence of wavelengths 3231, 3520, 3776, and 5352 A. Intensity measurements on the sensitized fluorescence and on the Hg 2537 A resonance fluorescence, observed at right angles to the direction of excitation, yielded cross sections of 3.0, 0.3, and 0.05 A/sup 2/ for collisional excitation transfer from Hg(6/sup 3/P/sub 1/) to the 8/sup 2/Ssub(1/2), 6/sup 2/D, and 7/sup 2/Ssub(1/2) states in thallium, respectively. The results are fully consistent with previously determined cross sections for excitation transfer in other binary metallic vapor systems.

Theory of analytical curves in atomic fluorescence flame spectrometry

NARCIS (Netherlands)

Hooymayers, H.P.

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

Determination of mercury in rice by cold vapor atomic fluorescence spectrometry after microwave-assisted digestion

Energy Technology Data Exchange (ETDEWEB)

Silva, Maria Jose da [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain); Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, 50740-550 Recife, PE (Brazil); Paim, Ana Paula S. [Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, 50740-550 Recife, PE (Brazil); Pimentel, Maria Fernanda [Departamento de Engenharia Quimica, Universidade Federal de Pernambuco, Recife, PE (Brazil); Cervera, M. Luisa, E-mail: m.luisa.cervera@uv.es [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain); Guardia, Miguel de la [Department of Analytical Chemistry, Edificio de Investigacion, University of Valencia, 50 Dr. Moliner Street, E-46100 Burjassot, Valencia (Spain)

2010-05-14

A cold vapor atomic fluorescence spectrometry method (CV-AFS) has been developed for the determination of Hg in rice samples at a few ng g{sup -1} concentration level. The method is based on the previous digestion of samples in a microwave oven with HNO{sub 3} and H{sub 2}O{sub 2} followed by dilution with water containing KBr/KBrO{sub 3} and hydroxylamine and reduction with SnCl{sub 2} in HCl using external calibration. The matrix interferences and the effect of nitrogen oxide vapors have been evaluated and the method validated using a certified reference material. The limit of detection of the method was 0.9 ng g{sup -1} with a recovery percentage of 95 {+-} 4% at an added concentration of 5 ng g{sup -1}. The concentration level of Hg found in 24 natural rice samples from different origin ranged between 1.3 and 7.8 ng g{sup -1}.

Measurement of fluorescence emission spectrum of few strongly driven atoms using an optical nanofiber.

Science.gov (United States)

Das, Manoj; Shirasaki, A; Nayak, K P; Morinaga, M; Le Kien, Fam; Hakuta, K

2010-08-02

We show that the fluorescence emission spectrum of few atoms can be measured by using an optical nanofiber combined with the optical heterodyne and photon correlation spectroscopy. The observed fluorescence spectrum of the atoms near the nanofiber shows negligible effects of the atom-surface interaction and agrees well with the Mollow triplet spectrum of free-space atoms at high excitation intensity.

Electrochemical hydride generation atomic fluorescence spectrometry for detection of tin in canned foods using polyaniline-modified lead cathode

Energy Technology Data Exchange (ETDEWEB)

Jiang Xianjuan [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Gan Wuer, E-mail: wgan@ustc.edu.cn [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wan Lingzhong; Deng Yun; Yang Qinghua; He Youzhao [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2010-12-15

An electrochemical hydride generation system with polyaniline-modified lead cathode was developed for tin determination by coupling with atomic fluorescence spectrometry. The tin fluorescence signal intensity was improved evidently as the polyaniline membrane could facilitate the transformation process from atomic tin to the SnH{sub 4} and prevent the aggradation of Sn atom on Pb electrode surface. The effects of experimental parameters and interferences have been studied. The limit of detection (LOD) was 1.5 ng mL{sup -1} (3{sigma}) and the relative standard deviation (RSD) was 3.3% for 11 consecutive measurements of 50 ng mL{sup -1} Sn(IV) standard solution.

High performance liquid chromatography--atomic fluorescence spectrometric determination of arsenic species in beer samples

International Nuclear Information System (INIS)

Melo Coelho, N.M.; Parrilla, Carmen; Cervera, M.L.; Pastor, A.; Guardia, M. de la

2003-01-01

A method has been developed for the direct determination of As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and As(V) in beers by hydride generation--atomic fluorescence spectrometry after separation of arsenic species by high performance liquid chromatography. Compounds were separated by anion-exchange chromatography with isocratic elution using KH 2 PO 4 /K 2 HPO 4 as mobile phase with elution times of 1.67, 2.08, 6.52 and 10.72 min for As(III), DMA, MMA and As(V), respectively. Parameters affecting the hydride generation of all arsenic species were studied and the best conditions were established as a reaction coil of 150 cm, for a sample injected volume of 100 μl, a 4.0% (m/v) solution of sodium tetrahydroborate and 2.0 mol l -1 hydrochloric acid with flow rates of 2.7 and 1.7 ml min -1 , respectively and a flow rate of 500 ml min -1 for the argon carrier gas. Under the best experimental conditions, the detection limit was found to be 0.12, 0.20, 0.27 and 0.39 μg l -1 for As(III), DMA, MMA and As(V), respectively. The relative standard deviation for eight independent determinations varied from 3.9 till 8.9% for species considered at a concentration level of 10.0 μg l -1 . Recovery and comparative studies evidenced that the method is suitable for the accurate determination of arsenic species in water and beer samples

Design and development of high-resolution atomic beam fluorescence spectroscopy facility for isotope shift and hyperfine structure measurements

International Nuclear Information System (INIS)

Acharyulu, G.V.S.G.; Sankari, M.; Kiran Kumar, P.V.; Suryanarayana, M.V.

2012-01-01

A high-resolution atomic beam fluorescence spectroscopy facility for the determination of isotope shifts and hyperfine structure in atomic species has been designed and developed. A resistively heated graphite tube atomic beam source was designed, tested and integrated into a compact interaction chamber for atomic beam fluorescence experiments. The design of the laser-atom interaction chamber and the source has been modified in a phased manner so as to achieve sub-Doppler resolution. The system has been used to record the hyperfine spectrum of the D2 transitions of Rb and K isotopes. The spectral resolution achieved is ∼ 26 MHz and is adequate to carry out high resolution measurement of isotope shifts and hyperfine structure of various atomic species. The other major advantage of the source is that it requires very small amounts of sample for achieving very good signal to noise ratio. (author)

Multielement methods of atomic fluorescence analysis of enviromental samples

International Nuclear Information System (INIS)

Rigin, V.I.

1985-01-01

A multielement method of atomic fluorescence analysis of environmental samples based on sample decomposition by autoclave fluorination and gas-phase atomization of volatile compounds in inductive araon plasma using a nondispersive polychromator is suggested. Detection limits of some elements (Be, Sr, Cd, V, Mo, Te, Ru etc.) for different sample forms introduced in to an analyzer are given

Electrochemical hydride generation atomic fluorescence spectrometry for detection of tin in canned foods using polyaniline-modified lead cathode.

Science.gov (United States)

Jiang, Xianjuan; Gan, Wuer; Wan, Lingzhong; Deng, Yun; Yang, Qinghua; He, Youzhao

2010-12-15

An electrochemical hydride generation system with polyaniline-modified lead cathode was developed for tin determination by coupling with atomic fluorescence spectrometry. The tin fluorescence signal intensity was improved evidently as the polyaniline membrane could facilitate the transformation process from atomic tin to the SnH(4) and prevent the aggradation of Sn atom on Pb electrode surface. The effects of experimental parameters and interferences have been studied. The limit of detection (LOD) was 1.5 ng mL(-1) (3σ) and the relative standard deviation (RSD) was 3.3% for 11 consecutive measurements of 50 ng mL(-1) Sn(IV) standard solution. Copyright © 2010 Elsevier B.V. All rights reserved.

Resonance fluorescence spectra of three-level atoms in a squeezed vacuum

International Nuclear Information System (INIS)

Ferguson, M.R.; Ficek, Z.; Dalton, B.J.

1996-01-01

The fluorescence field from one of the two allowed transitions in a three-level atom can sense squeezed fluctuations of a vacuum field coupled to the other transition. We examine the fluorescence spectra of strongly driven three-level atoms in Λ, V, and cascade configurations in which one of the two one-photon transitions is coupled to a finite-bandwidth squeezed vacuum field, when the bandwidth is much smaller than the difference in the atomic transition frequencies, though much larger than atomic decay rates and Rabi frequencies of the driving fields. The driving fields are on one-photon resonance, and the squeezed vacuum field is generated by a degenerate parameter oscillator. Details are only given for the Λ configuration. The extension to the V and cascade configurations is straightforward. We find that in all configurations the fluorescence spectra of the transition not coupled to the squeezed vacuum field are composed of five lines, one central and two pairs of sidebands, with intensities and widths strongly influenced by the squeezed vacuum field. However, only the central component and the outer sidebands exhibit a dependence on the squeezing phase. We also examine the fluorescence spectrum for the cascade configuration with a squeezed vacuum field on resonance with the two-photon transition between the ground and the most excited states and now generated by a nondegenerate parametric oscillator. In this case, where the squeezed vacuum field can be made coupled to both transitions, all spectral lines depend on the squeezing phase. The spectral features are explained in terms of the dressed-atom model of the system. We show that the coherent mixing of the atomic states by the strong driving fields modifies transition rates between the dressed states, which results in the selective phase dependence of the spectral features. copyright 1996 The American Physical Society

High performance liquid chromatography--atomic fluorescence spectrometric determination of arsenic species in beer samples

Energy Technology Data Exchange (ETDEWEB)

Melo Coelho, N.M.; Parrilla, Carmen; Cervera, M.L.; Pastor, A.; Guardia, M. de la

2003-04-10

A method has been developed for the direct determination of As(III), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and As(V) in beers by hydride generation--atomic fluorescence spectrometry after separation of arsenic species by high performance liquid chromatography. Compounds were separated by anion-exchange chromatography with isocratic elution using KH{sub 2}PO{sub 4}/K{sub 2}HPO{sub 4} as mobile phase with elution times of 1.67, 2.08, 6.52 and 10.72 min for As(III), DMA, MMA and As(V), respectively. Parameters affecting the hydride generation of all arsenic species were studied and the best conditions were established as a reaction coil of 150 cm, for a sample injected volume of 100 {mu}l, a 4.0% (m/v) solution of sodium tetrahydroborate and 2.0 mol l{sup -1} hydrochloric acid with flow rates of 2.7 and 1.7 ml min{sup -1}, respectively and a flow rate of 500 ml min{sup -1} for the argon carrier gas. Under the best experimental conditions, the detection limit was found to be 0.12, 0.20, 0.27 and 0.39 {mu}g l{sup -1} for As(III), DMA, MMA and As(V), respectively. The relative standard deviation for eight independent determinations varied from 3.9 till 8.9% for species considered at a concentration level of 10.0 {mu}g l{sup -1}. Recovery and comparative studies evidenced that the method is suitable for the accurate determination of arsenic species in water and beer samples.

Determination of lead in environmental waters with dispersive liquid-liquid microextraction prior to atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Zhou, Qingxiang; Zhao, Na; Xie, Guohong

2011-01-01

This paper established a new, rapid and sensitive method for the determination of lead in water samples preconcentrated by dispersive liquid-liquid microextraction (DLLME) prior to atomic fluorescence spectrometry. Dithizone was used as the chelating agent. In the DLLME procedure, lead formed lead-dithizone complex and migrated into the carbon tetrachloride micro-droplets. Important factors that would affect the extraction efficiency had been investigated including the kind and volume of extraction solvent and dispersive solvent, sample pH, the amount of chelating agent, extraction time and centrifugation time. The results showed that the coexisting ions containing in water samples had no obvious negative effect on the determination of lead. The experimental results indicated that the proposed method had a good linear range of 0.01-100 ng mL -1 (r 2 = 0.9990). The precision was 2.12% (RSD, n = 7) and the detection limit was 0.95 ng L -1 . Proposed method was validated with four real environmental samples and the results indicated that the proposed method was excellent for the future use and satisfied spiked recoveries were in the range of 92.9-97.4%.

Ultra-trace determination of methylmercuy in seafood by atomic fluorescence spectrometry coupled with electrochemical cold vapor generation

Energy Technology Data Exchange (ETDEWEB)

Zu, Wenchuan, E-mail: zuhongshuai@126.com [Beijing Institute of Technology, College of Chemistry, Beijing 100081 (China); Beijing Center for Physical & Chemical Analysis, Beijing 100089 (China); Wang, Zhenghao [Beijing Normal University, College of Chemistry, Beijing 100875 (China)

2016-03-05

Highlights: • Methylmercury detection by ECVG-AFS without pre-separation by HPLC is proposed. • Methylmercury is atomized by direct electrochemical reduction with no reductant. • Remarkably better sensitivity is obtained than the traditional HPLC-UV-AFS method. • Glassy carbon is the best cathode material to generate Hg vapor from methylmercury. - Abstract: A homemade electrochemical flow cell was adopted for the determination of methylmercury. The cold vapor of mercury atoms was generated from the surface of glassycarbon cathode through the method of electrolytic reduction and detected by atomic fluorescence spectroscopy subsequently. The operating conditions were optimized with 2 ng mL{sup −1} methylmercury standard solution. The caliberation curve was favorably linear when the concentrations of standard HgCH{sub 3}{sup +} solutions were in the range of 0.2–5 ng mL{sup −1}(as Hg). Under the optimized conditions, the limit of detection (LOD) for methylmercury was 1.88 × 10{sup −3} ng mL{sup −1} and the precision evaluated by relative standard deviation was 2.0% for six times 2 ng mL{sup −1} standard solution replicates. The terminal analytical results of seafood samples, available from local market, showed that the methylmercury content ranged within 3.7–45.8 ng g{sup −1}. The recoveries for methylmercury spiked samples were found to be in the range of 87.6–103.6% and the relative standard deviations below 5% (n = 6)were acquired, which showed this method was feasible for real sample analysis.

Quenching of the OH and nitrogen molecular emission by methane addition in an Ar capacitively coupled plasma to remove spectral interference in lead determination by atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Frentiu, T., E-mail: ftibi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Ponta, M., E-mail: mponta@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Mihaltan, A.I., E-mail: alinblaj2005@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Darvasi, E., E-mail: edarvasi@chem.ubbcluj.r [Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Arany Janos 11, 400028 Cluj-Napoca (Romania); Frentiu, M., E-mail: frentiu.maria@yahoo.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania); Cordos, E., E-mail: emilcordos@gmail.co [National Institute for Research and Development of Optoelectronics Bucharest - Research Institute for Analytical Instrumentation, Donath 67, 400293 Cluj-Napoca (Romania)

2010-07-15

A new method is proposed to remove the spectral interference on elements in atomic fluorescence spectrometry by quenching of the molecular emission of the OH radical (A{sup 2{Sigma}+} {yields} X{sup 2{Pi}}) and N{sub 2} second positive system (C{sup 3{Pi}}{sub u} {yields} B{sup 3{Sigma}}{sub g}) in the background spectrum of medium power Ar plasmas. The experiments were carried out in a radiofrequency capacitively coupled plasma (275 W, 27.12 MHz) by CH{sub 4} addition. The quenching is the result of the high affinity of OH radical for a hydrogen atom from the CH{sub 4} molecule and the collisions of the second kind between nitrogen excited molecules and CH{sub 4}, respectively. The decrease of the emission of N{sub 2} second positive system in the presence of CH{sub 4} is also the result of the deactivation of the metastable argon atoms that could excite the nitrogen molecules. For flow rates of 0.7 l min{sup -1} Ar with addition of 7.5 ml min{sup -1} CH{sub 4}, the molecular emission of OH and N{sub 2} was completely removed from the plasma jet spectrum at viewing heights above 60 mm. The molecular emission associated to CH and CH{sub 2} species was not observed in the emission spectrum of Ar/CH{sub 4} plasma in the ultraviolet range. The method was experimented for the determination of Pb at 283.31 nm by atomic fluorescence spectrometry with electrodeless discharge lamp and a multichannel microspectrometer. The detection limit was 35 ng ml{sup -1}, 2-3 times better than in atomic emission spectrometry using the same plasma source, and similar to that in hollow cathode lamp microwave plasma torch atomic fluorescence spectrometry.

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

International Nuclear Information System (INIS)

Talebi, S.M.

1997-01-01

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

State-dependent fluorescence of neutral atoms in optical potentials

Science.gov (United States)

Martinez-Dorantes, M.; Alt, W.; Gallego, J.; Ghosh, S.; Ratschbacher, L.; Meschede, D.

2018-02-01

Recently we have demonstrated scalable, nondestructive, and high-fidelity detection of the internal state of 87Rb neutral atoms in optical dipole traps using state-dependent fluorescence imaging [M. Martinez-Dorantes, W. Alt, J. Gallego, S. Ghosh, L. Ratschbacher, Y. Völzke, and D. Meschede, Phys. Rev. Lett. 119, 180503 (2017), 10.1103/PhysRevLett.119.180503]. In this paper we provide experimental procedures and interpretations to overcome the detrimental effects of heating-induced trap losses and state leakage. We present models for the dynamics of optically trapped atoms during state-dependent fluorescence imaging and verify our results by comparing Monte Carlo simulations with experimental data. Our systematic study of dipole force fluctuations heating in optical traps during near-resonant illumination shows that off-resonant light is preferable for state detection in tightly confining optical potentials.

Automated system for on-line determination of dimethylarsinic and inorganic arsenic by hydride generation-atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Chaparro, L.L.; Leal, L.O. [Renewable Energy and Environmental Protection Department, Advanced Materials Research Center (CIMAV), Chihuahua, Chihuahua (Mexico); Ferrer, L.; Cerda, V. [University of the Balearic Islands, Department of Chemistry, Palma de Mallorca (Spain)

2012-09-15

A multisyringe flow-injection approach has been coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS) with UV photo-oxidation for dimethylarsinic (DMA), inorganic As and total As determination, depending on the pre-treatment given to the sample (extraction or digestion). The implementation of a UV lamp allows on-line photo-oxidation of DMA and the following arsenic detection, whereas a bypass leads the flow directly to the HG-AFS system, performing inorganic arsenic determination. DMA concentration is calculated by the difference of total inorganic arsenic and measurement of the photo-oxidation step. The detection limits for DMA and inorganic arsenic were 0.09 and 0.47 {mu}g L{sup -1}, respectively. The repeatability values accomplished were of 2.4 and 1.8 %, whereas the injection frequencies were 24 and 28 injections per hour for DMA and inorganic arsenic, respectively. This method was validated by means of a solid reference material BCR-627 (muscle of tuna) with good agreement with the certified values. Satisfactory results for DMA and inorganic arsenic determination were obtained in several water matrices. The proposed method offers several advantages, such as increasing the sampling frequency, low detection limits and decreasing reagents and sample consumption, which leads to lower waste generation. (orig.)

Laser resonant ionization spectroscopy and laser-induced resonant fluorescence spectra of samarium atom

International Nuclear Information System (INIS)

Jin, Changtai

1995-01-01

We have measured new high-lying levels of Sm atom by two-colour resonant photoionisation spectroscopy; we have observed the isotope shifts of Sm atom by laser-induced resonant fluorescence spectroscopy; the lifetime of eight low-lying levels of Sm atom were measured by using pulsed laser-Boxcar technique in atomic beam.

Determination of dopant atomic positions with kinematical X-ray standing waves

International Nuclear Information System (INIS)

Walz, Bente

2011-11-01

Recent advances in the kinematic X-ray standing wave technique (KXSW) for the determination of the atomic coordinates and displacement parameters in nonperfect crystalline materials are described in this thesis. The methodology has been improved by considering three significant aspects: - the inclusion of weak multiple beam contributions - the excitation of secondary fluorescence in multiple-element samples - the influence of the crystal mosaicity on the fluorescence yield. The improvements allowed to successfully apply the method to investigate complex oxide materials of current interest for potential device applications. The thermally-induced interdiffusion of cobalt and manganese thin films on zinc oxide single crystals has been studied to determine which lattice sites are occupied preferentially. The data analysis revealed that after thermal diffusion the adsorbed atoms occupied zinc sites in the host lattice. The mean deviation of the cobalt atomic position from the zinc lattice site was comparable to the thermal displacement parameter of the zinc atoms. In the case of manganese a secondary phase was found on the surface. Measurements performed on LaSrMnO 4 provided new insight concerning the rotation of the oxygen octahedron around the manganese atoms and the concomitant displacements of the strontium and lanthanum atoms. It was found that the oxygen octahedra are rotated around the [100]-direction by 4,5 . The measurements in transmission geometry performed on titanium dioxide (rutile) demonstrated that KXSW measurements in the Laue geometry is a viable technique. By performing KXSW under grazing-incidence conditions it is possible to achieve depth resolution. The results clearly show that the extended KXSW technique is a versatile method for characterizing complex material systems. (orig.)

Fluorescence uranium determination

International Nuclear Information System (INIS)

Fernandez Cellini, R.; Crus Castillo, F. de la; Barrera Pinero, R.

1960-01-01

An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs

Resonance fluorescence and quantum jumps in single atoms: Testing the randomness of quantum mechanics

International Nuclear Information System (INIS)

Erber, T.; Hammerling, P.; Hockney, G.; Porrati, M.; Putterman, S.; La Jolla Institute, La Jolla, California 92037; Department of Physics, University of California, Los Angeles, California 90024)

1989-01-01

When a single trapped 198 Hg + ion is illuminated by two lasers, each tuned to an approximate transition, the resulting fluorescence switches on and off in a series of pulses resembling a bistable telegraph. This intermittent fluorescence can also be obtained by optical pumping with a single laser. Quantum jumps between successive atomic levels may be traced directly with multiple-resonance fluorescence. Atomic transition rates and photon antibunching distributions can be inferred from the pulse statistics and compared with quantum theory. Stochastic tests also indicate that the quantum telegraphs are good random number generators. During periods when the fluorescence is switched off, the radiationless atomic currents that generate the telegraph signals can be adjusted by varying the laser illumination: if this coherent evolution of the wave functions is sustained over sufficiently long time intervals, novel interactive precision measurements, near the limits of the time-energy uncertainty relations, are possible. Copyright 1989 Academic Press, Inc

High sensitivity detection of selenium by laser excited atomic fluorescence spectrometry using electrothermal atomization

International Nuclear Information System (INIS)

Heitmann, U.; Hese, A.; Schoknecht, G.; Gries, W.

1995-01-01

The high sensitivity detection of the trace element selenium is reported. The analytical method applied is Laser Excited Atomic Fluorescence Spectrometry using Electrothermal Atomization within a graphite furnace atomizer. For the production of tunable laser radiation in the VUV spectral region a laser system was developed which consists of two dye lasers pumped by a Nd:YAG laser. The laser radiations are subsequently frequency doubled and sum frequency mixed by nonlinear optical KDP or BBO crystals, respectively. The system works with a repetition rate of 20 Hz and provides output energies of up to 100 μJ in the VUV at a pulse duration of 5 ns. The analytical investigations were focused on the detection of selenium in aqueous solutions and samples of human whole blood. From measurements on aqueous standards detection limits of 1.5 ng/l for selenium were obtained, with corresponding absolute detected masses of only 15 fg. The linear dynamic range spanned six orders of magnitude and good precision was achieved. In case of human whole blood samples the recovery was found to be within the range of 96% to 104%. The determination of the selenium content yielded medians of [119.5 ± 17.3] μg/l for 200 frozen blood samples taken in 1988 and [109.1 ± 15.6] μg/l for 103 fresh blood samples. (author)

Application of laser fluorescence spectroscopy by two-photon excitation into atomic hydrogen density measurement in reactive plasmas

International Nuclear Information System (INIS)

Kajiwara, Toshinori; Takeda, Kazuyuki; Kim, Hee Je; Park, Won Zoo; Muraoka, Katsunori; Akazaki, Masanori; Okada, Tatsuo; Maeda, Mitsuo.

1990-01-01

Density profiles of hydrogen atoms in reactive plasmas of hydrogen and methane gases were measured, for the first time, using the laser fluorescence spectroscopy by two-photon excitation of Lyman beta transition and observation at the Balmer alpha radiation. Absolute density determinations showed atomic densities of around 3 x 10 17 m -3 , or the degree of dissociation to be 10 -4 . Densities along the axis perpendicular to the RF electrode showed peaked profiles, which were due to the balance of atomic hydrogen production by electron impact on molecules against diffusion loss to the walls. (author)

Determination of mercury in ash and soil samples by oxygen flask combustion method-Cold vapor atomic fluorescence spectrometry (CVAFS)

International Nuclear Information System (INIS)

Geng Wenhua; Nakajima, Tsunenori; Takanashi, Hirokazu; Ohki, Akira

2008-01-01

A simple method was developed for the determination of mercury (Hg) in coal fly ash (CFA), waste incineration ash (WIA), and soil by use of oxygen flask combustion (OFC) followed by cold vapor atomic fluorescence spectrometry (CVAFS). A KMnO 4 solution was used as an absorbent in the OFC method, and the sample containing a combustion agent and an ash or soil sample was combusted by the OFC method. By use of Hg-free graphite as the combustion agent, the determination of Hg in ash and soil was successfully carried out; the Hg-free graphite was prepared by use of a mild pyrolysis procedure at 500 deg. C. For six certified reference materials (three CFA samples and three soil samples), the values of Hg obtained by this method were in good agreement with the certified or reference values. In addition, real samples including nine CFAs collected from some coal-fired power plants, five WIAs collected from waste incineration plants, and two soils were analyzed by the present method, and the data were compared to those from microwave-acid digestion (MW-AD) method

Ultrasensitive determination of mercury in human saliva by atomic fluorescence spectrometry based on solidified floating organic drop microextraction

International Nuclear Information System (INIS)

Yuan, C.-G.; Wang, J.; Jin, Y.

2012-01-01

We report on a new, rapid and simple method for the determination of ultra-trace quantities of mercury ion in human saliva. It is based on solidified floating organic drop microextraction and detection by cold vapor atomic fluorescence spectrometry (CV-AFS). Mercury ion was complexed with diethyldithiocarbamate, and the hydrophobic complex was then extracted into fine droplets of 1-undecanol. By cooling in an ice bath after extraction, the droplets in solution solidify to form a single ball floating on the surface of solution. The solidified micro drop containing the mercury complex was then transferred for determination by CV-AFS. The effects of pH value, concentration of chelating reagent, quantity of 1-undecanol, sample volume, equilibration temperature and time were investigated. Under the optimum conditions, the preconcentration of a 25-mL sample is accomplished with an enrichment factor of 182. The limit of detection is 2.5 ng L -1 . The relative standard deviation for seven replicate determinations at 0.1 ng mL -1 level is 4.1%. The method was applied to the determination of mercury in saliva samples collected from four volunteers. Two volunteers having dental amalgam fillings had 0.4 ng mL -1 mercury in their saliva, whereas mercury was not detectable in the saliva of two volunteers who had no dental fillings. (author)

Determination of arsenite, arsenate, monomethylarsonic acid and dimethylarsinic acid in cereals by hydride generation atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Matos Reyes, M.N. [Department of Analytical Chemistry, University of Valencia, 50 Dr. Moliner Street, 46100 Burjassot, Valencia (Spain); Department of Chemistry, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente, 225, 22453-900, Rio de Janeiro, RJ (Brazil); Cervera, M.L. [Department of Analytical Chemistry, University of Valencia, 50 Dr. Moliner Street, 46100 Burjassot, Valencia (Spain)], E-mail: m.luisa.cervera@uv.es; Campos, R.C. [Department of Chemistry, Pontificia Universidade Catolica do Rio de Janeiro, Rua Marques de Sao Vicente, 225, 22453-900, Rio de Janeiro, RJ (Brazil); Guardia, M. de la [Department of Analytical Chemistry, University of Valencia, 50 Dr. Moliner Street, 46100 Burjassot, Valencia (Spain)

2007-09-15

A fast, sensitive and simple non-chromatographic analytical method was developed for the speciation analysis of toxic arsenic species in cereal samples, namely rice and wheat semolina. An ultrasound-assisted extraction of the toxic arsenic species was performed with 1 mol L{sup -1} H{sub 3}PO{sub 4} and 0.1% (m/v) Triton XT-114. After extraction, As(III), As(V), dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) concentrations were determined by hydride generation atomic fluorescence spectrometry using a series of proportional equations corresponding to four different experimental reduction conditions. The detection limits of the method were 1.3, 0.9, 1.5 and 0.6 ng g{sup -1} for As(III), As(V), DMA and MMA, respectively, expressed in terms of sample dry weight. Recoveries were always greater than 90%, and no species interconversion occurred. The speciation analysis of a rice flour reference material certified for total arsenic led to coherent results, which were also in agreement with other speciation studies made on the same certified reference material.

Advances in low atomic number element analysis by wavelength dispersive x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Vrebos, B.

1996-01-01

Traditionally, the analysis of low atomic number has been a chal1enging task for wavelength dispersive x-ray fluorescence spectrometry. Among the most important factors influencing analysis of the low atomic number elements (from Z=11 downwards) are the fluorescence yield, absorption and the dispersion. The effect of each of these factors on the overall performance will be illustrated. The long wavelengths involved (longer than I nm) used to pose severe problems concerning the monochromator used. Early instruments relied on lead stearate or Blodgett Langmuir soap films for the diffraction of the characteristic radiation. Nowadays, synthetic multilayers are commonly used. The performance of these multilayers is determined by the reflectivity, the resolution and the absorption of the characteristic radiation to be diffracted. These parameters can be optimised by adequately selecting the composition of the materials involved. The sensitivity of the modem instruments is sufficient to allow quantitative analysis. However, this aspect of WDS XRF is still met with considerable scepticism. Examples of quantitative analysis will be given to illustrate the current capability

Resonance fluorescence microscopy via three-dimensional atom localization

Science.gov (United States)

Panchadhyayee, Pradipta; Dutta, Bibhas Kumar; Das, Nityananda; Mahapatra, Prasanta Kumar

2018-02-01

A scheme is proposed to realize three-dimensional (3D) atom localization in a driven two-level atomic system via resonance fluorescence. The field arrangement for the atom localization involves the application of three mutually orthogonal standing-wave fields and an additional traveling-wave coupling field. We have shown the efficacy of such field arrangement in tuning the spatially modulated resonance in all directions. Under different parametric conditions, the 3D localization patterns originate with various shapes such as sphere, sheets, disk, bowling pin, snake flute, flower vase. High-precision localization is achieved when the radiation field detuning equals twice the combined Rabi frequencies of the standing-wave fields. Application of a traveling-wave field of suitable amplitude at optimum radiation field detuning under symmetric standing-wave configuration leads to 100% detection probability even in sub-wavelength domain. Asymmetric field configuration is also taken into consideration to exhibit atom localization with appreciable precision compared to that of the symmetric case. The momentum distribution of the localized atoms is found to follow the Heisenberg uncertainty principle under the validity of Raman-Nath approximation. The proposed field configuration is suitable for application in the study of atom localization in an optical lattice arrangement.

Resonance fluorescence spectra of a three-level atom driven by two strong laser fields

International Nuclear Information System (INIS)

Peng Jinsheng.

1986-12-01

The resonance fluorescence of a three-level atom interacted with two high-power laser fields is investigated in strong field approximation. The fluorescence distribution is obtained by means of the theory of dressing transformation. (author). 15 refs, 2 figs

Determination of nuclear spins of short-lived isotopes by laser induced fluorescence

International Nuclear Information System (INIS)

Buchinger, F.; Dabkiewicz, P.; Kremmling, H.; Kuehl, T.; Mueller, A.C.; Schuessler, H.A.

1980-01-01

The spins of several nuclear ground and isomeric states have been measured for a number of mercury isotopes. The fluorescent light from the 6s6p 3 P 1 state is observed at 2537 Angstroem after excitation with the frequency doubled output of a pulsed dye laser. Four different laser induced fluorescence techniques were tested for their applicability: double resonance, Hanle effect, time delayed integral Hanle beats, and time resolved quantum beats. The sensitivity and selectivity of these models are compared with emphasis on the determination of spins of nuclei far from beta-stability, where short half lives and low production yields restrict the number of available atoms. The experiments were carried out on-line with the ISOLDE isotope separator at CERN at densities as low as 10 6 atoms/cm 3 . Results for the very neutron deficient high spin mercury isomers with half lives of several seconds, but also for the ground states of the abundant low spin stable mercury isotopes, are given as examples. The test measurements determined the nuclear spins of the odd sup(185m-191m)Hg isomers to be I = 13/2. (orig.)

Spatial discrimination against background with different optical systems for collection of fluorescence in laser-excited atomic fluorescence spectrometry with a graphite tube electrothermal atomizer.

Science.gov (United States)

Yuzefovsky, A I; Lonardo, R F; Michel, R G

1995-07-01

A single 90 degrees off-axis ellipsoidal mirror fragment was used in a dispersive detection system for electrothermal atomization laser-excited atomic fluorescence spectrometry. The performance of the new optical arrangement was compared with those of optical arrangements that employed a plane mirror in combination with biconvex or plano-convex lenses. All the optical arrangements collected fluorescence in a scheme called front surface illustration. BEAM-4, an optical ray tracing program, was used for calculations of spatial ray distributions and optical collection efficiency for the various optical configurations. Experimentally, the best collection efficiency was obtained by use of the ellipsoidal mirror, in qualitative agreement with simulations done by use of the BEAM-4 software. The best detection limit for cobalt with the new optical arrangement was 20 fg, which was a factor of 5 better than that obtained with conventional optical arrangements with otherwise the same instrumentation. The signal-to-background ratio and the fluorescence collection efficiency were also studied as a function of position of the optical components for the various optical arrangements. For both cobalt and phosphorus, the signal-to-background ratio with the new optical arrangement remained stable within 10-20% during +/- 8 mm shifts in the position of the detection system from the focal plane of the optics. Overall, the new optical arrangement offered high collection efficiency, excellent sensitivity, and facile optical alignment due to efficient spatial separation between the fluorescence signal and the background radiation. The advantages of the new optical arrangement were particularly important during measurements in the presence of high levels of blackbody radiation.

X-ray fluorescence holography

CERN Document Server

Hayashi, K; Takahashi, Y

2003-01-01

X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

Determination of arsenic speciation in sulfidic waters by Ion Chromatography Hydride-Generation Atomic Fluorescence Spectrometry (IC-HG-AFS).

Science.gov (United States)

Keller, Nicole S; Stefánsson, Andri; Sigfússon, Bergur

2014-10-01

A method for the analysis of arsenic species in aqueous sulfide samples is presented. The method uses an ion chromatography system connected with a Hydride-Generation Atomic Fluorescence Spectrometer (IC-HG-AFS). With this method inorganic As(III) and As(V) species in water samples can be analyzed, including arsenite (HnAs(III)O3(n-3)), thioarsenite (HnAs(III)S3(n-3)), arsenate (HnAs(V)O4(n-3)), monothioarsenate (HnAs(V)SO3(n-3)), dithioarsenate (HnAs(V)S2O2(n-3)), trithioarsenate (HnAs(V)S3O(n-3)) and tetrathioarsenate (HnAs(V)S4(n-3)). The peak identification and retention times were determined based on standard analysis of the various arsenic compounds. The analytical detection limit was ~1-3 µg L(-1) (LOD), depending on the quality of the baseline. This low detection limit makes this method also applicable to discriminate between waters meeting the drinking water standard of max. 10 µg L(-1) As, and waters that do not meet this standard. The new method was successfully applied for on-site determination of arsenic species in natural sulfidic waters, in which seven species were unambiguously identified. Copyright © 2014 Elsevier B.V. All rights reserved.

Single atom spectroscopy: Decreased scattering delocalization at high energy losses, effects of atomic movement and X-ray fluorescence yield

International Nuclear Information System (INIS)

Tizei, Luiz H.G.; Iizumi, Yoko; Okazaki, Toshiya; Nakanishi, Ryo; Kitaura, Ryo; Shinohara, Hisanori; Suenaga, Kazu

2016-01-01

Single atom localization and identification is crucial in understanding effects which depend on the specific local environment of atoms. In advanced nanometer scale materials, the characteristics of individual atoms may play an important role. Here, we describe spectroscopic experiments (electron energy loss spectroscopy, EELS, and Energy Dispersed X-ray spectroscopy, EDX) using a low voltage transmission electron microscope designed towards single atom analysis. For EELS, we discuss the advantages of using lower primary electron energy (30 keV and 60 keV) and higher energy losses (above 800 eV). The effect of atomic movement is considered. Finally, we discuss the possibility of using atomically resolved EELS and EDX data to measure the fluorescence yield for X-ray emission.

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,…

Applications of X-ray fluorescence holography to determine local lattice distortions

International Nuclear Information System (INIS)

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya

2014-01-01

Highlights: • We summarized topics of X-ray fluorescence holography focused on the local lattice distortions. • We found details of behaviors of nearest neighbor atoms around dopants. • We found the average distributions of the atoms at the individual sites in mixed crystals. • Distorted and undistorted sires sometimes coexist in a same mixed crystal. - Abstract: X-ray fluorescence holography (XFH) is a method for investigating atomic order up to the medium ranges, and can provide 3D atomic images around specific elements within a radius of nm order. In addition to these characteristics, XFH is sensitive to positional fluctuations of atoms, and therefore it is useful for characterizing the local lattice distortions around specific elements. We have applied XFH to dopants and mixed crystals. We found interesting features in local lattice distortions, such as the displacements of first-neighbor atoms around dopants, far-sighted views of the atomistic fluctuations in mixed crystals, and the coexistence of distorted/undistorted sites in the same material

Determination of chlorine in coal by X-ray fluorescence spectrometry method

Energy Technology Data Exchange (ETDEWEB)

Marek, S.; Bojarska, K. [Central Mining Institute, Katowice (Poland). Dept. of Environmental Monitoring

1997-12-31

Determination of chlorine contents in coal is essential for both environmental protection and its technological use. The existing method of chlorine determination in coal are titration methods which have considerable errors particularly in the low concentration range. The elaborated method with the use of X-ray fluorescence spectrometry in a comparison to the other methods is much faster and has better precision and accuracy. The principle of the method lies in the measurement of X-ray fluorescence radiation intensity which is emitted by chlorine in a sample and its comparison with standards. The calibration of the elaborated XRF method is based on natural coals having various concentrations of chlorine within the whole range of its occurrence in Polish coals. Concentrations for the calibration purpose were obtained by the determination of chlorine contents in selected coals by atomic absorption spectrometry method. The procedure of sample preparation for direct X-ray measurements, instrumental measuring conditions and the way of calibration curve preparation are described in the paper. All X-ray measurements were done with a Phillips sequential X-ray fluorescence spectrometer. A double anode Cr-Au X-ray tube with maximum power 3000 MW was used as the excitation source. 5 figs., 4 tabs.

Evaluation of a tungsten coil atomization-laser-induced fluorescence detection approach for trace elemental analysis

International Nuclear Information System (INIS)

Ezer, Muhsin; Elwood, Seth A.; Jones, Bradley T.; Simeonsson, Josef B.

2006-01-01

The analytical utility of a tungsten (W)-coil atomization-laser-induced fluorescence (LIF) approach has been evaluated for trace level measurements of elemental chromium (Cr), arsenic (As), selenium (Se), antimony (Sb), lead (Pb), tin (Sn), copper (Cu), thallium (Tl), indium (In), cadmium (Cd), zinc (Zn) and mercury (Hg). Measurements of As, Cr, In, Se, Sb, Pb, Tl, and Sn were performed by laser-induced fluorescence using a single dye laser operating near 460 nm whose output was converted by frequency doubling and stimulated Raman scattering to wavelengths ranging from 196 to 286 nm for atomic excitation. Absolute limits of detection (LODs) of 1, 0.3, 0.3, 0.2, 1, 6, 1, 0.2 and 0.8 pg and concentration LODs of 100, 30, 30, 20, 100, 600, 100, 20, and 80 pg/mL were achieved for As, Se, Sb, Sn, In, Cu, Cr, Pb and Tl, respectively. Determinations of Hg, Pb, Zn and Cd were performed using two-color excitation approaches and resulted in absolute LODs of 2, 30, 5 and 0.6 pg, respectively, and concentration LODs of 200, 3000, 500 and 60 pg/mL, respectively. The sensitivities achieved by the W-coil LIF approaches compare well with those reported by W-coil atomic absorption spectrometry, graphite furnace atomic absorption spectrometry, and graphite furnace electrothermal atomization-LIF approaches. The accuracy of the approach was verified through the analysis of a multielement reference solution containing Sb, Pb and Tl which each had certified performance acceptance limits of 19.6-20.4 μg/mL. The determined concentrations were 20.05 ± 2.60, 20.70 ± 2.27 and 20.60 ± 2.46 μg/mL, for Sb, Pb and Tl, respectively. The results demonstrate that W-coil LIF provides good analytical performance for trace analyses due to its high sensitivity, linearity, and capability to measure multiple elements using a single tunable laser and suggest that the development of portable W-coil LIF instrumentation using compact, solid-state lasers is feasible

Evaluation of a tungsten coil atomization-laser-induced fluorescence detection approach for trace elemental analysis.

Science.gov (United States)

Ezer, Muhsin; Elwood, Seth A; Jones, Bradley T; Simeonsson, Josef B

2006-06-30

The analytical utility of a tungsten (W)-coil atomization-laser-induced fluorescence (LIF) approach has been evaluated for trace level measurements of elemental chromium (Cr), arsenic (As), selenium (Se), antimony (Sb), lead (Pb), tin (Sn), copper (Cu), thallium (Tl), indium (In), cadmium (Cd), zinc (Zn) and mercury (Hg). Measurements of As, Cr, In, Se, Sb, Pb, Tl, and Sn were performed by laser-induced fluorescence using a single dye laser operating near 460 nm whose output was converted by frequency doubling and stimulated Raman scattering to wavelengths ranging from 196 to 286 nm for atomic excitation. Absolute limits of detection (LODs) of 1, 0.3, 0.3, 0.2, 1, 6, 1, 0.2 and 0.8 pg and concentration LODs of 100, 30, 30, 20, 100, 600, 100, 20, and 80 pg/mL were achieved for As, Se, Sb, Sn, In, Cu, Cr, Pb and Tl, respectively. Determinations of Hg, Pb, Zn and Cd were performed using two-color excitation approaches and resulted in absolute LODs of 2, 30, 5 and 0.6 pg, respectively, and concentration LODs of 200, 3000, 500 and 60 pg/mL, respectively. The sensitivities achieved by the W-coil LIF approaches compare well with those reported by W-coil atomic absorption spectrometry, graphite furnace atomic absorption spectrometry, and graphite furnace electrothermal atomization-LIF approaches. The accuracy of the approach was verified through the analysis of a multielement reference solution containing Sb, Pb and Tl which each had certified performance acceptance limits of 19.6-20.4 microg/mL. The determined concentrations were 20.05+/-2.60, 20.70+/-2.27 and 20.60+/-2.46 microg/mL, for Sb, Pb and Tl, respectively. The results demonstrate that W-coil LIF provides good analytical performance for trace analyses due to its high sensitivity, linearity, and capability to measure multiple elements using a single tunable laser and suggest that the development of portable W-coil LIF instrumentation using compact, solid-state lasers is feasible.

X-ray fluorescence holography and multiple-energy x-ray holography: A critical comparison of atomic images

International Nuclear Information System (INIS)

Len, P.M.; Gog, T.; Fadley, C.S.; Materlik, G.

1997-01-01

We compare x-ray fluorescence holography (XFH) and multiple-energy x-ray holography (MEXH), two techniques that have recently been used to obtain experimental three-dimensional atomic images. For single-energy holograms, these methods are equivalent by virtue of the optical reciprocity theorem. However, XFH can only record holographic information at the characteristic fluorescence energies of the emitting species, while MEXH can record holographic information at any energy above the fluorescent edge of the emitter, thus enabling the suppression of real-twin overlaps and other aberrations and artifacts in atomic images. copyright 1997 The American Physical Society

Atomic-absorption determination of tantalum and niobium in ore concentrates

International Nuclear Information System (INIS)

Elinson, S.V.; Korovin, Yu.I.; Kuchumov, V.A.

1975-01-01

A flame atom-absorption method was developed for determining tantalum and niobium at their level greater than 5% in Ta-Nb ore concentrates. Flame was produced by a nitrous oxide-acetylene mixture. The optimal composition of a buffer (3 mg/ml) of iron was determined by the method of factorial planning of the experiment and steep ascention by gradient. The optimizing parameter in factorial planning was obtained from the difference of optical densities of Ta and Nb, by taking the average value for two solutions which had dissimilar total composition and which imitated the real composition of the ore concentrates, i.e., the value of (ΔD/Dsub(av))sub(Ta) or (ΔD/Dsub(av))sub(Nb). The optimization of analytical conditions corresponded to the condition (ΔD/Dsub(av))→ 0, which indicated that the chosen optimizing parameter also facilitated the attainment of maximum D values. The variation coefficient in the determination of Ta and Nb was respectively 0.8 and 1.4%. There was a good agreement between the results obtained in Ta analysis by the atom-absorption and the extraction-gravimetric methods, and in Nb analysis by the atom-absorption, differential spectrophotometric and x-ray fluorescence methods

Supersonic pulsed free-jet of atoms and molecules of refractory metals: laser induced fluorescence spectroscopic studies on zirconium atoms and zirconium oxide molecules

International Nuclear Information System (INIS)

Nakhale, S.G.

2004-11-01

The experimental setup for generating supersonic pulsed free-jet containing atoms and molecules of refractory nature has been built. The technique of laser vaporization in conjunction with supersonic cooling is used to generate these species. The cooled atoms and molecules in supersonic free-jet are probed by laser induced fluorescence spectroscopy. In particular, the technique has been used to perform low-resolution laser induced fluorescence spectroscopy, limited by laser linewidth, on cold Zr atoms and ZrO molecules. The translational temperatures of ∼ 26.5 K and the rotational temperatures of ∼ 81 K have been achieved. It is possible to achieve the Doppler width of few tens of MHz allowing it to perform high-resolution spectroscopy on these atomic and molecular species. Also because of low rotational temperature of molecules the spectral congestion is greatly reduced. In general, this technique can be applied to perform spectroscopy on atoms and molecules of refractory nature. (author)

Hydride generation atomic fluorescence spectrometric determination of As, Bi, Sb, Se(IV) and Te(IV) in aqua regia extracts from atmospheric particulate matter using multivariate optimization

International Nuclear Information System (INIS)

Moscoso-Perez, Carmen; Moreda-Pineiro, Jorge; Lopez-Mahia, Purificacion; Muniategui-Lorenzo, Soledad; Fernandez-Fernandez, Esther; Prada-Rodriguez, Dario

2004-01-01

A highly sensitive and simple method, based on hydride generation and atomic fluorescence detection, has been developed for the determination of As, Bi, Sb, Se(IV) and Te(IV) in aqua regia extracts from atmospheric particulate matter samples. Atmospheric particulates matter was collected on glass fiber filters using a medium volume sampler (PM1 particulate matter). Two-level factorial designs have been used to optimise the hydride generation atomic fluorescence spectrometry (HG-AFS) procedure. The effects of several parameters affecting the hydride generation efficiency (hydrochloric acid, sodium tetrahydroborate and potassium iodide concentrations and flow rates) have been evaluated using a Plackett-Burman experimental design. In addition, parameters affecting the hydride measurement (delay, analysis and memory times) have been also investigated. The significant parameters obtained (sodium tetrahydroborate concentration, sodium tetrahydroborate flow rate and analysis time for As; hydrochloric acid concentration and sodium tetrahydroborate flow rate for Se(IV); and sodium tetrahydroborate concentration and sodium tetrahydroborate flow rate for Te(IV)) have been optimized by using 2 n + star central composite design. Hydrochloric acid concentration and sodium tetrahydroborate flow rate were the significant parameters obtained for Sb and Bi determination, respectively. Using a univariate approach these parameters were optimized. The accuracy of methods have been verified by using several certified reference materials: SRM 1648 (urban particulate matter) and SRM 1649a (urban dust). Detection limits in the range of 6 x 10 -3 to 0.2 ng m -3 have been achieved. The developed methods were applied to several atmospheric particulate matter samples corresponding to A Coruna city (NW Spain)

Single atom spectroscopy: Decreased scattering delocalization at high energy losses, effects of atomic movement and X-ray fluorescence yield.

Science.gov (United States)

Tizei, Luiz H G; Iizumi, Yoko; Okazaki, Toshiya; Nakanishi, Ryo; Kitaura, Ryo; Shinohara, Hisanori; Suenaga, Kazu

2016-01-01

Single atom localization and identification is crucial in understanding effects which depend on the specific local environment of atoms. In advanced nanometer scale materials, the characteristics of individual atoms may play an important role. Here, we describe spectroscopic experiments (electron energy loss spectroscopy, EELS, and Energy Dispersed X-ray spectroscopy, EDX) using a low voltage transmission electron microscope designed towards single atom analysis. For EELS, we discuss the advantages of using lower primary electron energy (30 keV and 60 keV) and higher energy losses (above 800 eV). The effect of atomic movement is considered. Finally, we discuss the possibility of using atomically resolved EELS and EDX data to measure the fluorescence yield for X-ray emission. Copyright © 2015 Elsevier B.V. All rights reserved.

[Improvement of the method for methylmercury determination in aquatic products using liquid chromatography online coupled with atomic fluorescence spectrometry].

Science.gov (United States)

Shang, Xiaohong; Zhao, Yunfeng; Zhang, Lei; Li, Xiaowei; Wu, Yongning

2011-07-01

The improvement method was developed for methylmercury determination using liquid chromatography online coupled with cold vapor atomic fluorescence spectrometry (LC-CV-AFS). Cysteine was used as complexing agent in mobile phase instead of mercaptoethanol. Under the optimized conditions, baseline separation of mercury species could be achieved within 8 min on a C18 column with a mobile phase of 5% (v/v) acetonitrile-1 g/L L-cysteine-50 mmol/L ammonium acetate aqueous solution. The linear range of calibration curve of methylmercury was 1-50 microg/L and the limit of detection (S/N = 3) for methylmercury was 0.3 microg/L. Ultrasonication assisted hydrochloric acid extraction was used to extract methylmercury from seafood samples. The sample extract was cleaned up by a C18 solid phase extraction (SPE) cartridge. For validation of the method, certified reference materials and spiked seafood samples were analyzed. The determined methylmercury contents of certified reference materials NIST1566b, BCR464 and GBW10029 agreed well with the certified values. The determined methylmercury values for Food Analysis Performance Assessment Scheme (FAPAS) sample 07115 were satisfied. The recoveries of methylmercury in seafood samples at three spiked levels (10, 50 and 500 microg/kg) ranged from 89% to 112%, including cooked seafood food. The precision of the method based on relative standard deviation (RSD) was not more than 7%. The present method of LC-CV-AFS is accurate, sensitive, simple, and can meet the demand of methylmercury determination in seafood.

Development of an electrothermal atomization laser-excited atomic fluorescence spectrometry procedure for direct measurements of arsenic in diluted serum.

Science.gov (United States)

Swart, D J; Simeonsson, J B

1999-11-01

A procedure for the direct determination of arsenic in diluted serum by electrothermal atomization laser-excited atomic fluorescence spectrometry (ETA-LEAFS) is reported. Laser radiation needed to excite As at 193.696 and 197.197 nm is generated as the second anti-Stokes stimulated Raman scattering output of a frequency-doubled dye laser operating near 230.5 and 235.5 nm, respectively. Two different LEAFS schemes have been utilized and provide limits of detection of 200-300 fg for As in aqueous standards. When measurements of serum samples diluted 1:10 with deionized water are performed, a stable background signal is observed that can be accounted for by taking measurements with the laser tuned off-wavelength. No As is detected in any of the bovine or human serum samples analyzed. Measurements of 100 pg/mL standard additions of As to a diluted bovine serum sample utilizing either inorganic or organic As species demonstrate a linear relationship of the fluorescence signal to As spike concentration, but exhibit a sensitivity of approximately half that observed in pure aqueous standards. The limit of detection for As in 1:10 diluted serum samples is 65 pg/mL or 650 fg absolute mass, which corresponds to 0.65 ng/mL As in undiluted serum. To our knowledge, the ETA-LEAFS procedure is currently the only one capable of directly measuring As in diluted serum at these levels.

Synergetic enhancement effect of ionic liquid and diethyldithiocarbamate on the chemical vapor generation of nickel for its atomic fluorescence spectrometric determination in biological samples

International Nuclear Information System (INIS)

Zhang Chuan; Li Yan; Wu Peng; Yan Xiuping

2009-01-01

Room-temperature ionic liquid in combination with sodium diethyldithiocarbamate (DDTC) was used to synergetically improve the chemical vapor generation (CVG) of nickel. Volatile species of nickel were effectively generated through reduction of acidified analyte solution with KBH 4 in the presence of 0.02% DDTC and 25 mmol L -1 1-butyl-3-methylimidazolium bromide ([C 4 mim]Br) at room temperature. Thus, a new flow injection (FI)-CVG-atomic fluorescence spectrometric (FI-CVG-AFS) method was developed for determination of nickel with a detection limit of 0.65 μg L -1 (3 s) and a sampling frequency of 180 h -1 . With consumption of 0.5 mL sample solution, an enhancement factor of 2400 was obtained. The precision (RSD) for eleven replicate determinations of 20 μg L -1 Ni was 3.4%. The developed FI-CVG-AFS method was successfully applied to determination of trace Ni in several certified biological reference materials.

Simultaneous differential spinning disk fluorescence optical sectioning microscopy and nanomechanical mapping atomic force microscopy

International Nuclear Information System (INIS)

Miranda, Adelaide; De Beule, Pieter A. A.; Martins, Marco

2015-01-01

Combined microscopy techniques offer the life science research community a powerful tool to investigate complex biological systems and their interactions. Here, we present a new combined microscopy platform based on fluorescence optical sectioning microscopy through aperture correlation microscopy with a Differential Spinning Disk (DSD) and nanomechanical mapping with an Atomic Force Microscope (AFM). The illumination scheme of the DSD microscope unit, contrary to standard single or multi-point confocal microscopes, provides a time-independent illumination of the AFM cantilever. This enables a distortion-free simultaneous operation of fluorescence optical sectioning microscopy and atomic force microscopy with standard probes. In this context, we discuss sample heating due to AFM cantilever illumination with fluorescence excitation light. Integration of a DSD fluorescence optical sectioning unit with an AFM platform requires mitigation of mechanical noise transfer of the spinning disk. We identify and present two solutions to almost annul this noise in the AFM measurement process. The new combined microscopy platform is applied to the characterization of a DOPC/DOPS (4:1) lipid structures labelled with a lipophilic cationic indocarbocyanine dye deposited on a mica substrate

Simultaneous differential spinning disk fluorescence optical sectioning microscopy and nanomechanical mapping atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Miranda, Adelaide; De Beule, Pieter A. A., E-mail: pieter.de-beule@inl.int [Applied Nano-Optics Laboratory, International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga, s/n, 4715-330 Braga (Portugal); Martins, Marco [Nano-ICs Group, International Iberian Nanotechnology Laboratory, Avenida Mestre José Veiga, s/n, 4715-330 Braga (Portugal)

2015-09-15

Combined microscopy techniques offer the life science research community a powerful tool to investigate complex biological systems and their interactions. Here, we present a new combined microscopy platform based on fluorescence optical sectioning microscopy through aperture correlation microscopy with a Differential Spinning Disk (DSD) and nanomechanical mapping with an Atomic Force Microscope (AFM). The illumination scheme of the DSD microscope unit, contrary to standard single or multi-point confocal microscopes, provides a time-independent illumination of the AFM cantilever. This enables a distortion-free simultaneous operation of fluorescence optical sectioning microscopy and atomic force microscopy with standard probes. In this context, we discuss sample heating due to AFM cantilever illumination with fluorescence excitation light. Integration of a DSD fluorescence optical sectioning unit with an AFM platform requires mitigation of mechanical noise transfer of the spinning disk. We identify and present two solutions to almost annul this noise in the AFM measurement process. The new combined microscopy platform is applied to the characterization of a DOPC/DOPS (4:1) lipid structures labelled with a lipophilic cationic indocarbocyanine dye deposited on a mica substrate.

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

Czech Academy of Sciences Publication Activity Database

Marschner, Karel; Musil, Stanislav; Dědina, Jiří

2015-01-01

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

Containerless high temperature property measurements by atomic fluorescence

Science.gov (United States)

Schiffman, R. A.; Walker, C. A.

1984-01-01

Laser induced fluorescence (LIF) techniques for containerless study of high temperature processes and material properties was studied. Gas jet and electromagnetic levitation and electromagnetic and laser heating techniques are used with LIF in earth-based containerless high temperature experiments. Included are the development of an apparatus and its use in the studies of (1) chemical reactions on Al2O3, molybdenum, tungsten and LaB6 specimens, (2) methods for noncontact specimen temperature measurement, (3) levitation jet properties and (4) radiative lifetime and collisional energy transfer rates for electronically excited atoms.

Laser-induced fluorescence of metal-atom impurities in a neutral beam

International Nuclear Information System (INIS)

Burrell, C.F.; Pyle, R.V.; Sabetimani, Z.; Schlachter, A.S.

1984-10-01

The need to limit impurities in fusion devices to low levels is well known. We have investigated, by the technique of laser-induced fluorescence, the concentration of heavy-metal atoms in a neutral beam caused by their evaporation from the hot filaments in a conventional high-current multifilament hydrogen-ion source

Atomic emission and atomic fluorescence spectroscopy in the direct current plasma

International Nuclear Information System (INIS)

Hendrick, M.S.

1985-01-01

The Direct Current Plasma (DCP) was investigated as a source for Atomic Emission (AE) and Atomic Fluorescence Spectrometry (AFS). The DCP was optimized for AE analyses using simplex optimization and Box-Behnken partial factorial experimental design, varying argon flows, and plasma position. Results were compared with a univariate search carried out in the region of the simplex optimum. Canonical analysis demonstrated that no true optimum exists for sensitivity, precision, or drift. A stationary ridge, where combinations of conditions gave comparable instrumental responses, was found. The DCP as an excitation source for AFS in a flame was used for diagnostic studies of the DCP. Moving the aerosol introduction tube behind the DCP with respect to the flame improved the characteristics of the DCP as a narrow line source, although self-absorption was observed at high concentrations of metal salt solutions in the DCP. Detection limits for Cd, Co, Cr, Cu, Fe, Mg, Mn, Zn, and Ni were in the low ng/mL region. Theoretical expressions for scatter correction with a two-line technique were derived, although no correction was necessary to achieve accurate results for standard reference materials

[Cloud Point extraction for determination of mercury in Chinese herbal medicine by hydride generation atomic fluorescence spectrometry with optimization using Box-Behnken design].

Science.gov (United States)

Wang, Mei; Li, Shan; Zhou, Jian-dong; Xu, Ying; Long, Jun-biao; Yang, Bing-yi

2014-08-01

Cloud point extraction (CPE) is proposed as a pre-concentration procedure for the determination of Hg in Chinese herbal medicine samples by hydride generation-atomic fluorescence spectrometry (HG-AFS). Hg2+ was reacted with dithizone to form hydrophobic chelate under the condition of pH. Using Triton X-114, as surfactant, chelate was quantitatively extracted into small volume of the surfactant-rich phase by heating the solution in a water bath for 15 min and centrifuging. Four variables including pH, dithizone concentration, Triton X-114 concentration and equilibrium temperature (T) showed the significant effect on extraction efficiency of total Hg evaluated by single-factor experiment, and Box-Behnken design and response surface method- ology were adopted to further investigate the mutual interactions between these variables and to identify their optimal values that would generate maximum extraction efficiency. The results showed that the binomial was used to fit the response to experimental levels of each variable. ALL linear, quadratic terms of four variables, and interactions between pH and Trion X-114, pH and di- thizone affected the response value(extraction efficiency) significantly at 5% level. The optimum extraction conditions were as follows: pH 5.1, Triton X-114 concentration of 1.16 g x L(-1), dithizone concentration of 4.87 mol x L(-1), and T 58.2 degrees C, the predicted value of fluorescence was 4528.74 under the optimum conditions, and the experimental value had only 2.1% difference with it. Under the conditions, fluorescence was linear to mercury concentration in the range of 1-5 microg x L(-1). The limit of detection obtained was 0.01247 microg x L(-1) with the relative standard deviations (R.S.D.) for six replicate determinations of 1.30%. The proposed method was successfully applied to determination of Hg in morindae Radix, Andrographitis and dried tangerine samples with the recoveries of 95.0%-100.0%. Apparently Box-Behnken design combined with

In situ detection of atomic and molecular iodine using Resonance and Off-Resonance Fluorescence by Lamp Excitation: ROFLEX

Directory of Open Access Journals (Sweden)

J. C. Gómez Martín

2011-01-01

Full Text Available We demonstrate a new instrument for in situ detection of atmospheric iodine atoms and molecules based on atomic and molecular resonance and off-resonance ultraviolet fluorescence excited by lamp emission. The instrument combines the robustness, light weight, low power consumption and efficient excitation of radio-frequency discharge light sources with the high sensitivity of the photon counting technique. Calibration of I₂ fluorescence is achieved via quantitative detection of the molecule by Incoherent Broad Band Cavity-enhanced Absorption Spectroscopy. Atomic iodine fluorescence signal is calibrated by controlled broad band photolysis of known I₂ concentrations in the visible spectral range at atmospheric pressure. The instrument has been optimised in laboratory experiments to reach detection limits of 1.2 pptv for I atoms and 13 pptv for I₂, for S/N = 1 and 10 min of integration time. The ROFLEX system has been deployed in a field campaign in northern Spain, representing the first concurrent observation of ambient mixing ratios of iodine atoms and molecules in the 1–350 pptv range.

UV light-emitting-diode photochemical mercury vapor generation for atomic fluorescence spectrometry.

Science.gov (United States)

Hou, Xiaoling; Ai, Xi; Jiang, Xiaoming; Deng, Pengchi; Zheng, Chengbin; Lv, Yi

2012-02-07

A new, miniaturized and low power consumption photochemical vapor generation (PVG) technique utilizing an ultraviolet light-emitting diode (UV-LED) lamp is described, and further validated via the determination of trace mercury. In the presence of formic acid, the mercury cold vapor is favourably generated from Hg(2+) solutions by UV-LED irradiation, and then rapidly transported to an atomic fluorescence spectrometer for detection. Optimum conditions for PVG and interferences from concomitant elements were investigated in detail. Under optimum conditions, a limit of detection (LOD) of 0.01 μg L(-1) was obtained, and the precision was better than 3.2% (n = 11, RSD) at 1 μg L(-1) Hg(2+). No obvious interferences from any common ions were evident. The methodology was successfully applied to the determination of mercury in National Research Council Canada DORM-3 fish muscle tissue and several water samples.

Ambient-temperature trap/release of arsenic by dielectric barrier discharge and its application to ultratrace arsenic determination in surface water followed by atomic fluorescence spectrometry

Science.gov (United States)

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HGAFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical m...

Heavy atom induced room temperature fluorescence quenching of PAH from a glucose glass

Energy Technology Data Exchange (ETDEWEB)

Marlow, Matt, E-mail: matthew.marlow@nicholls.edu

2017-06-15

Sugar glasses are a relatively new matrix for solid-matrix luminescence. Molecular interactions within the sugar glass are not well understood. Fluorescence quenching was used to investigate molecular interactions within the sugar glass matrix. The room temperature fluorescence quenching of pyrene and naphthalene was observed from a glucose glass. The heavy atom salt NaI was the quencher. Two solvent compositions 50/50 and 60/40 MeOH/water, used for glass preparation, were examined for their effect on glass rigidity and molecular interactions. A complex static mechanism was observed for glasses prepared with 50/50 MeOH/water. This data was fit to the sphere of action model and associations constants determined. A Stern-Volmer static mechanism of quenching was observed for glasses prepared with 60/40 MeOH/water. This data fit the Stern-Volmer equation and association constants were determined. A larger association constant was observed for pyrene compared to naphthalene for both solvent systems used. Pyrene had a larger association constant with a sugar glass prepared with 60/40 MeOH/water compared to 50/50 MeOH/water implying a greater association between pyrene and iodide. The greater association is a reflection of a more rigid internal environment for the sugar glass prepared with 60/40 MeOH/water.

Determination of potassium concentration in organic samples by means of x-ray fluorescence analysis

International Nuclear Information System (INIS)

Soto Moran, R.L.; Szgedi, S.

1993-01-01

By means of x-ray fluorescence analysis and the inner standard method using KH 2 PO 4 as the added chemical compound, potassium concentration of roots, stems , leaf, flowers and grains from Quinua (Chenopodium Quinoa Willd). which was previously treated with a nitrogen ed fertilizers has been determined taking into account the increasing effect the average atomic number due to used standard. Experimental errors are lower than 10 %

Colorful Polyelectrolytes: An Atom Transfer Radical Polymerization Route to Fluorescent Polystyrene Sulfonate.

Science.gov (United States)

Huberty, Wayne; Tong, Xiaowei; Balamurugan, Sreelatha; Deville, Kyle; Russo, Paul S; Zhang, Donghui

2016-03-01

A labeled green fluorescent polystyrene sulfonate (LNaPSS) has been synthesized using atom transfer radical polymerization of a styrene sulfonate monomer with a fluorescent co-monomer, fluorescein thiocyanate-vinyl aniline. As a result this 100 % sulfonated polymer contains no hydrophobic patches along the chain backbone besides the fluorescent marker itself. The concentration of the fluorescent monomer was kept low to maintain the characteristic properties of the anionic polyelectrolyte, LNaPSS. ATRP conditions facilitated the production of polymers spanning a range of molecular weights from 35,000 to 175,000 in gram-scale batches with polydispersity indices of 1.01-1.24. Molecular weight increased with the monomer to initiator ratio. Gel permeation chromatography results show a unimodal distribution, and the polymer structure was also confirmed by (1)H NMR and FT-IR spectroscopy. Fluorescence spectroscopy confirmed covalent bonding of fluorescein isothiocyanate to the polymer, indicating that the polymer is suitable as a probe in fluorescence microscopy. To demonstrate this ability, the polymer was used to locate structural features in salt crystals formed during drying, as in the evaporation of sea mist. A second application to probe diffusion studies is also demonstrated.

Use of X-ray fluorescence for metal determination in polymers

International Nuclear Information System (INIS)

Guidorizzi, Lorenza

1996-01-01

X-Ray fluorescence spectrometry was used to determine metals and non-metals in polyester polymers. The greatest advantage of this technique over others like Atomic Absorption or Plasma Emission is that no sample previous treatment (like calcination or acid digestion) is required. Other advantage of this method is its fastness allowing a complete analysis in just few minutes. On the other hand, this method requires metals higher than 15 ppm. Below those values there is a loss of the analysis' precision. Another advantage of this technique is the possibility of making qualitative metal analysis, scanning unknown samples and identifying the found peaks automatically. (author)

The role of total-reflection x-ray fluorescence in atomic spectroscopy

International Nuclear Information System (INIS)

Toelg, G.; Klockenkaemper, R.

1993-01-01

Total-reflection X-ray fluorescence (TXRF) is a universal and economic method for the simultaneous determination of elements with atomic numbers > 11 down to the lower pg-level. It is a microanalytical tool for the analysis of small sample amounts placed on flat carriers and for contaminations on flat sample surfaces. Analyses of stratified near-surface layers are made possible by varying the incident angle of the primary beam in the region of total-reflection. This non-destructive method is especially suitable for thin layers of a few nanometres, deposited on wafer material although not usable as a microprobe method with a high lateral resolution. Furthermore, depth profiles of biological samples can be recorded by means of microtome sectioning of only a few micrometres, as, for example in the gradient analysis of human organs. In addition to micro- and surface-layer analysis, TXRF is effectively applied to element trace analysis. Homogeneous solutions, for example aqueous solutions, high-purity acids or body fluids, are pipetted onto carriers and, after evaporation, the dry residues are analyzed directly down to the pg/ml region. Particularly advantageous is the absence of matrix effects, so that an easy calibration can be carried out by adding a single internal standard element. A digestion or separation step preceding the actual determination becomes necessary if a more complex matrix is to be analysed or especially low detection limits have to be reached. A critical evaluation of the recent developments in atomic spectroscopy places TXRF in a leading position. Its outstanding features compete with those of e.g. electrothermal atomic absorption spectrometry (ETAAS), microwave induced plasma optical emission spectroscopy (MIP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) in the field of micro- and trace analysis and with Rutherford backscattering (RBS) and secondary ion mass spectrometry (SIMS) in the surface-layer analysis. (author)

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

International Nuclear Information System (INIS)

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

2011-01-01

A method for a direct measurement of X-ray projections of the atomic structure is described. Projections of the atomic structure around Nb atoms in a LiNbO 3 single crystal were obtained from a white-beam X-ray absorption anisotropy pattern detected using Nb K fluorescence. Projections of the atomic structure around Nb atoms in a LiNbO 3 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

Fluorescence measurement of atomic oxygen concentration in a dielectric barrier discharge

Science.gov (United States)

Dvořák, P.; Mrkvičková, M.; Obrusník, A.; Kratzer, J.; Dědina, J.; Procházka, V.

2017-06-01

Concentration of atomic oxygen was measured in a volume dielectric barrier discharge (DBD) ignited in mixtures of Ar + O2(+ H2) at atmospheric pressure. Two-photon absorption laser induced fluorescence (TALIF) of atomic oxygen was used and this method was calibrated by TALIF of Xe in a mixture of argon and a trace of xenon. The calibration was performed at atmospheric pressure and it was shown that quenching by three-body collisions has negligible effect on the life time of excited Xe atoms. The concentration of atomic oxygen in the DBD was around 1021 m-3 and it was stable during the whole discharge period. The concentration did not depend much on the electric power delivered to the discharge provided that the power was sufficiently high so that the visible discharge filled the whole reactor volume. Both the addition of hydrogen or replacing of argon by helium led to a significant decrease of atomic oxygen concentration. The TALIF measurements of O concentration levels in the DBD plasma performed in this work are made use of e.g. in the field analytical chemistry. The results contribute to understanding the processes of analyte hydride preconcentration and subsequent atomization in the field of trace element analysis where DBD plasma atomizers are employed.

Redox speciation analysis of antimony in soil extracts by hydride generation atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Fuentes, Edwar; Pinochet, Hugo; Gregori, Ida de; Potin-Gautier, Martine

2003-01-01

A sensitive atomic spectrometric method for the redox speciation analysis of antimony in soils is described. The method is based on the selective generation of stibine from Sb(III) in a continuous flow system using atomic fluorescence spectrometry for detection. Sb(V) is masked by citric or oxalic acid in HCl medium. The procedure was optimized with synthetic solutions of Sb(III) and Sb(V). The effect of carboxylic acid and HCl concentration on the recovery of Sb(III) and Sb(V) species from standard solutions, and on the fluorescence signal were studied. Both species were extracted from soil with H 2 O, 0.05 mol l -1 EDTA and 0.25 mol l -1 H 2 SO 4 . Since the soil samples were collected from sites impacted by copper mining activities, the effect of Cu 2+ on the determination of antimony in synthetic solutions and soil extracts was studied. Cu 2+ decreased the Sb(III) signal, but had no effect on the total antimony determination. Therefore, the selective determination of Sb(III) was carried out in citric acid-HCl medium, using the analyte addition technique. Total antimony in soil extracts was determined using the standard calibration technique after reducing Sb(V) to Sb(III) at room temperature with KI-ascorbic acid. The Sb(V) concentration was calculated from the difference between total antimony and Sb(III). The limits of detection (PS Analytical, Excalibur Millennium model) were 17 and 10 ng l -1 for Sb(III) and total antimony, respectively, and the R.S.D. at the 0.5-μg l -1 level were 2.5 and 2.4%, respectively. The total antimony concentration of soils is in the mg kg -1 range; the Sb recovery from the different soils by the extracting solutions was between less than 0.02% and approximately 10%. Similar recoveries were obtained using EDTA and sulfuric acid solutions. Sb(V) was found to be the main antimony species extracted from soils

Pulp tissue in sex determination: A fluorescent microscopic study

Science.gov (United States)

Nayar, Amit; Singh, Harkanwal Preet; Leekha, Swati

2014-01-01

Aims: To determine and compare the reliability of pulp tissue in determination of sex and to analyze whether caries have any effect on fluorescent body test. Materials and Methods: This study was carried on 50 maxillary and mandibular teeth (25 male teeth and 25 female teeth), which were indicated for extraction. The teeth are categorized into 5 groups, 10 each (5 from males and 5 from females) on the basis of caries progression. The pulp cells are stained with quinacrine hydrochloride and observed with fluorescent microscope for fluorescent body. Gender is determined by identification of Y chromosome fluorescence in dental pulp. Results: Fluorescent bodies were found to be more in sound teeth in males as the caries increase the mean percentage of fluorescent bodies observed decreases in males. We also observed the fluorescent spots in females, and the value of the spot increases in female as the caries progresses, thereby giving false positive results in females. Conclusion: Sex determination by fluorescent staining of the Y chromosome is a reliable technique in teeth with healthy pulps or caries with enamel or up to half way of dentin. Teeth with caries involving pulp cannot be used for sex determination. PMID:25125912

Optimal Fluorescence Waveband Determination for Detecting Defective Cherry Tomatoes Using a Fluorescence Excitation-Emission Matrix

Directory of Open Access Journals (Sweden)

In-Suck Baek

2014-11-01

Full Text Available A multi-spectral fluorescence imaging technique was used to detect defective cherry tomatoes. The fluorescence excitation and emission matrix was used to measure for defects, sound surface and stem areas to determine the optimal fluorescence excitation and emission wavelengths for discrimination. Two-way ANOVA revealed the optimal excitation wavelength for detecting defect areas was 410 nm. Principal component analysis (PCA was applied to the fluorescence emission spectra of all regions at 410 nm excitation to determine the emission wavelengths for defect detection. The major emission wavelengths were 688 nm and 506 nm for the detection. Fluorescence images combined with the determined emission wavebands demonstrated the feasibility of detecting defective cherry tomatoes with >98% accuracy. Multi-spectral fluorescence imaging has potential utility in non-destructive quality sorting of cherry tomatoes.

Determination of arsenic species in seafood samples from the Aegean Sea by liquid chromatography-(photo-oxidation)-hydride generation-atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, Richard [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Soeroes, Csilla [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Ipolyi, Ildiko [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Fodor, Peter [Department of Applied Chemistry, Corvinus University, Villanyi ut 29-35, 1118 Budapest (Hungary); Thomaidis, Nikolaos S. [Laboratory of Analytical Chemistry, Department of Chemistry, University of Athens, Panepistiomopolis Zografou, 15776 Athens (Greece)]. E-mail: ntho@chem.uoa.gr

2005-08-15

In this study arsenic compounds were determined in mussels (Mytulis galloprovincialis), anchovies (Engraulis encrasicholus), sea-breams (Sparus aurata), sea bass (Dicentrarchus labrax) and sardines (Sardina pilchardus) collected from Aegean Sea using liquid chromatography-photo-oxidation-hydride generation-atomic fluorescence spectrometry [LC-(PO)-HG-AFS] system. Twelve arsenicals were separated and determined on the basis of their difference in two properties: (i) the pK {sub a} values and (ii) hydride generation capacity. The separation was carried out both with an anion- and a cation-exchange column, with and without photo-oxidation. In all the samples arsenobetaine, AB was detected as the major compound (concentrations ranging between 2.7 and 23.1 {mu}g g{sup -1} dry weight), with trace amounts of arsenite, As(III), dimethylarsinic acid, DMA and arsenocholine, AC, also present. Arsenosugars were detected only in the mussel samples (in concentrations of 0.9-3.6 {mu}g g{sup -1} dry weight), along with the presence of an unknown compound, which, based on its retention time on the anion-exchange column Hamilton PRP-X100 and a recent communication [E. Schmeisser, R. Raml, K.A. Francesconi, D. Kuehnelt, A. Lindberg, Cs. Soeroes, W. Goessler, Chem. Commun. 16 (2004) 1824], is supposed to be a thio-arsenic analogue.

Observation of self-assembled fluorescent beads by scanning near-field optical microscopy and atomic force microscopy

International Nuclear Information System (INIS)

Oh, Y.J.; Jo, W.; Kim, Min-Gon; Kyu Park, Hyun; Hyun Chung, Bong

2006-01-01

Optical response and topography of fluorescent latex beads both on flat self-assembled monolayer and on a micron-patterned surface with poly(dimethylsiloxane) are studied. Scanning near-field optical microscopy and atomic force microscopy were utilized together for detecting fluorescence and imaging topography of the patterned latex beads, respectively. As a result, the micro-patterned latex beads where a specific chemical binding occurred show a strong signal, whereas no signals are observed in the case of nonspecific binding. With fluorescein isothiocyanate (FITC), it is convenient to measure fluorescence signal from the patterned beads allowing us to monitor the small balls of fluorescent latex

Fluorescent atom coincidence spectroscopy of extremely neutron-deficient barium isotopes

International Nuclear Information System (INIS)

Wells, S.A.; Evans, D.E.; Griffith, J.A.R.; Eastham, D.A.; Groves, J.; Smith, J.R.H.; Tolfree, D.W.L.; Warner, D.D.; Billowes, J.; Grant, I.S.; Walker, P.M.

1988-01-01

Fluorescent atom coincidence spectroscopy (FACS) has been used to measure the nuclear mean square radii and moments of the extremely neutron-deficient isotopes 120-124 Ba. At N=65 an abrupt change in nuclear mean square charge radii is observed which can be understood in terms of the occupation of the spin-orbit partner g 7/2 5/2[413] neutron and g 9/2 9/2[404] proton orbitals and the consequent enhancement of the n-p interaction. (orig.)

Analysis of a single-atom dipole trap

International Nuclear Information System (INIS)

Weber, Markus; Volz, Juergen; Saucke, Karen; Kurtsiefer, Christian; Weinfurter, Harald

2006-01-01

We describe a simple experimental technique which allows us to store a single 87 Rb atom in an optical dipole trap. Due to light-induced two-body collisions during the loading stage of the trap the maximum number of captured atoms is locked to one. This collisional blockade effect is confirmed by the observation of photon antibunching in the detected fluorescence light. The spectral properties of single photons emitted by the atom were studied with a narrow-band scanning cavity. We find that the atomic fluorescence spectrum is dominated by the spectral width of the exciting laser light field. In addition we observe a spectral broadening of the atomic fluorescence light due to the Doppler effect. This allows us to determine the mean kinetic energy of the trapped atom corresponding to a temperature of 105 μK. This simple single-atom trap is the key element for the generation of atom-photon entanglement required for future applications in quantum communication and a first loophole-free test of Bell's inequality

Fluorescent determination of neptunium in plutonium

International Nuclear Information System (INIS)

Alexandruk, V.M.; Babaev, A.S.; Dem'yanova, T.A.; Stepanov, A.V.

1991-01-01

This paper describes a new procedure for direct determination of Neptunium in Plutonium using laser induced time resolved fluorescence method. The procedure based on measurement of fluorescence intensity of Neptunium followed its concentration in effective layer of pellet of calcium fluoride. Detection limit of determination of Neptunium is 2 10 -12 g. At the level of Neptunium content in Plutonium more than 5 ppm relative standard deviation is equal 0.08-0.12. For carrying out of single measurement it is necessary neither more nor less 5 mkg Plutonium

Experimental determination of the x-ray atomic fundamental parameters of nickel

Science.gov (United States)

Ménesguen, Y.; Lépy, M.-C.; Hönicke, P.; Müller, M.; Unterumsberger, R.; Beckhoff, B.; Hoszowska, J.; Dousse, J.-Cl; Błachucki, W.; Ito, Y.; Yamashita, M.; Fukushima, S.

2018-02-01

The x-ray atomic properties of nickel (Ni) were investigated in a unique approach combining different experimental techniques to obtain new, useful and reliable values of atomic fundamental parameters for x-ray spectrometric purposes and for comparison with theoretical predictions. We determined the mass attenuation coefficients in an energy range covering the L- and K-absorption edges, the K-shell fluorescence yield and the Kβ/Kα and Kβ1, 3/Kα1, 2 transition probability ratios. The obtained line profiles and linewidths of the Kα and Kβ transitions in Ni can be considered as the contribution of the satellite lines arising from the [KM] shake processes suggested by Deutsch et al (1995 Phys. Rev. A 51 283) and Ito et al (2016 Phys. Rev. A 94 042506). Comparison of the new data with several databases showed good agreement, but also discrepancies were found with existing tabulated values.

Determination of As in tobacco by using electrochemical hydride generation at a Nafion® solid polymer electrolyte cell hyphenated with atomic fluorescence spectrometry

Science.gov (United States)

Yang, Qinghua; Gan, Wuer; Deng, Yun; Sun, Huihui

2011-11-01

In the present work, a novel solid polymer electrolyte hydride generation (SPE-HG) cell was developed. The home-made SPE-HG cell, mainly composed of three components (Nafion®117 membrane for separating and H + exchanging, a soft graphite felt cathode and a Ti mesh modified by Ir anode), was employed for detecting As by coupling to atomic fluorescence spectrometry (AFS). The H + generated by electrolysis of pure water in anode chamber transferred to cathode chamber through SPE, and immediately reacted with As 3 + to generate AsH 3. The relative mechanisms and operation conditions for hydride generation of As were investigated in detail. The developed cell employed water as an alternative of acid anolyte, with virtues of low-cost, more than 6 months lifetime and environment friendly compared with the conventional cell. Under the optimized conditions, the limit of determination of As 3 + for sample blank solution was 0.12 μg L - 1 , the RSD was 2.9% for 10 consecutive measurements of 5 μg L - 1 As 3 + standard solution. The accuracy of the method was verified by the determination of As in the reference Tea (GBW07605) and the developed method was successfully applied to determine trace amounts of As in tobacco samples with recovery from 97% to 103%.

Determination of zinc in ammoniacal ore leaching solutions by X-ray fluorescence spectrometry using a radioactive source

International Nuclear Information System (INIS)

Cornejo, N.; Afailal, A.; Garcia, F.; Palacios, M.

1994-01-01

A method was developed for the fast determination of zinc in leaching solutions by radioisotope energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The measured intensities were used to develop regression models for estimating the zinc concentration. The primary radiation was provided by the 244 Cm radioisotope. Several experimental parameters including the saturation thickness and detection limit were determined. The advantages of the utilization of conditioning agents with elements of low atomic number such as nitric acid were established. (orig.)

Examinations for the determination of the flux density of sputtered iron using laser induced fluorescence

International Nuclear Information System (INIS)

Schweer, H.B.

1983-11-01

In this work investigations are described to measure the flux density of sputtered iron atoms by means of laser induced fluorescence. In a laboratory experiment an iron target (stainless steel 316, Inconel 600), was bombarded with 10 keV Ar + and 2.5 keV H + and the population distribution of the energy levels of the ground state a 5 D and the metastable state a 5 F was measured. In the plasma wall region in the ISX-B tokamak at the Oak Ridge National Laboratory (USA) neutral iron atoms were measured the first time by laser induced fluorescence. A detection limit of 10 6 atoms/cm 3 was found and sputtered iron atoms were observed in the first 15 ms of the discharge. (orig./BRB)

Atomic imaging by x-ray-fluorescence holography and electron-emission holography: A comparative theoretical study

International Nuclear Information System (INIS)

Len, P.M.; Thevuthasan, S.; Fadley, C.S.; Kaduwela, A.P.; Van Hove, M.A.

1994-01-01

We consider from a theoretical viewpoint the direct imaging of atoms at and near the surfaces of solids by both x-ray-fluorescence holography (XFH) and electron-emission holography (EEH). The more ideal nature of x-ray scattering makes XFH images superior to those in single-energy EEH. The overlap of real and twin features for pairs of atoms at ±a can cause their XFH or EEH atomic images to cancel for certain combinations of wave vector and |a|. The relative merits of XFH and EEH for structure studies are considered

X-ray fluorescence from the element with atomic number Z=120

International Nuclear Information System (INIS)

Fregeau, M.O.; Morjean, M.; Bonnet, E.; Chbihi, A.; Frankland, J.D.; Jacquet, D.; Rivet, M.F.; Tassan-Got, L.; Dechery, F.; Drouart, A.; Nalpas, L.; Ledoux, X.; Parlog, M.; Parlog, M.; Ciortea, C.; Dumitriu, D.; Fluerasu, D.; Gugiu, M.; Gramegna, F.; Kravchuk, V.L.; Marchi, T.; Marchi, T.; Fabris, D.; Corsi, A.; Barlini, S.

2012-01-01

An atomic clock based on x-ray fluorescence yields has been used to estimate the mean characteristic time for fusion followed by fission in reactions 238 U + 64 Ni at 6.6 MeV/A. Inner shell vacancies are created during the collisions in the electronic structure of the possibly formed Z = 120 compound nuclei. The filling of these vacancies accompanied by a x-ray emission with energies characteristic of Z = 120 can take place only if the atomic transitions occur before nuclear fission. Therefore, the x-ray yield characteristic of the united atom with 120 protons is strongly related to the fission time and to the vacancy lifetimes. K x rays from the element with Z = 120 have been unambiguously identified from a coupled analysis of the involved nuclear reaction mechanisms and of the measured photon spectra. A minimum mean fission time τ f = 2.5 * 10 -18 s has been deduced for Z = 120 from the measured x-ray multiplicity. (authors)

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

Science.gov (United States)

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

2017-08-01

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

Disruption of the hydrogen bonding network determines the pH-induced non-fluorescent state of the fluorescent protein ZsYellow by protonation of Glu221.

Science.gov (United States)

Bae, Ji-Eun; Kim, In Jung; Nam, Ki Hyun

2017-11-04

Many fluorescent proteins (FPs) exhibit fluorescence quenching at a low pH. This pH-induced non-fluorescent state of an FP serves as a useful indicator of the cellular pH. ZsYellow is widely used as an optical marker in molecular biology, but its pH-induced non-fluorescent state has not been characterized. Here, we report the pH-dependent spectral properties of ZsYellow, which exhibited the pH-induced non-fluorescence state at a pH below 4.0. We determined the crystal structures of ZsYellow at pH 3.5 (non-fluorescence state) and 8.0 (fluorescence state), which revealed the cis-configuration of the chromophore without pH-induced isomerization. In the non-fluorescence state, Arg95, which is involved in stabilization of the exited state of the chromophore, was found to more loosely interact with the carbonyl oxygen atom of the chromophore when compared to the interaction at pH 8.0. In the fluorescence state, Glu221, which is involved in the hydrogen bonding network around the chromophore, stably interacted with Gln42 and His202. By contrast, in the non-fluorescence state, the protonated conserved Glu221 residue exhibited a large conformational change and was separated from His202 by 5.46 Å, resulting in breakdown of the hydrogen bond network. Our results provide insight into the critical role of the conserved Glu221 residue for generating the pH-induced non-fluorescent state. Copyright © 2017 Elsevier Inc. All rights reserved.

Laser-excited atomic fluorescence spectrometry in a pressure-controlled electrothermal atomizer.

Science.gov (United States)

Lonardo, R F; Yuzefovsky, A I; Irwin, R L; Michel, R G

1996-02-01

A theoretical model was developed to describe the loss of analyte atoms in graphite furnaces during atomization. The model was based on two functions, one that described the supply of analyte by vaporization, and another that described the removal of the analyte by diffusion. Variation in working pressure was shown to affect the competition between these two processes. Optimal atomization efficiency was predicted to occur at a pressure where the supply of the analyte was maximized, and gas phase interactions between the analyte and matrix were minimized. Experiments to test the model included the direct determination of phosphorus and tellurium in nickel alloys and of cobalt in glass. In all cases, reduction in working pressure from atmospheric pressure to 7 Pa decreased sensitivity by 2 orders of magnitude, but improved temporal peak shape. For the atomization of tellurium directly from a solid nickel alloy, and the atomization of cobalt from an aqueous solution, no change in sensitivity was observed as the working pressure was reduced from atmospheric pressure to approximately 70 kPa. If a reduction in working pressure affected only the diffusion of the analyte, poorer sensitivity should have been obtained. Only a commensurate increase in analyte vaporization could account for maintained sensitivity at lower working pressures. Overall, analyte vaporization was not dramatically improved at reduced working pressures, and maximum atomization efficiency was found to occur near atmospheric pressure.

Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries

International Nuclear Information System (INIS)

Pereira Junior, Sergio Matias

2014-01-01

Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

Determination of total Sb,Se Te, and Bi and evaluation of their inorganic species in garlic by hydride-generation-atomic-fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Matos Reyes, M.N.; Cervera, M.L.; Guardia, M. de la [University of Valencia, Department of Analytical Chemistry, Burjassot, Valencia (Spain)

2009-07-15

A sensitive and simple analytical method has been developed for determination of Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), Te(VI), and Bi(III) in garlic samples by using hydride-generation-atomic-fluorescence spectrometry (HG-AFS). The method is based on a single extraction of the inorganic species by sonication at room temperature with 1 mol L{sup -1} H{sub 2}SO{sub 4} and washing of the solid phase with 0.1% (w/v) EDTA, followed by measurement of the corresponding hydrides generated under two different experimental conditions directly and after a pre-reduction step. The limit of detection of the method was 0.7 ng g{sup -1} for Sb(III), 1.0 ng g{sup -1} for Sb(V), 1.3 ng g{sup -1} for Se(IV), 1.0 ng g{sup -1} for Se(VI), 1.1 ng g{sup -1} for Te(IV), 0.5 ng g{sup -1} for Te(VI), and 0.9 ng g{sup -1} for Bi(III), in all cases expressed in terms of sample dry weight. (orig.)

Applicability of multisyringe chromatography coupled to cold-vapor atomic fluorescence spectrometry for mercury speciation analysis

International Nuclear Information System (INIS)

Guzmán-Mar, J.L.; Hinojosa-Reyes, L.; Serra, A.M.; Hernández-Ramírez, A.; Cerdà, V.

2011-01-01

Graphical abstract: An automatic system, based on the applicability of multisyringe chromatography (MSC) coupled to cold-vapor atomic fluorescence spectrometry (CV/AFS) detection is developed for mercury speciation. Highlights: ► The on-line coupling of MSC to CV/AFS was developed for mercury speciation analysis. ► The speciation of MeHg + , Hg 2+ and EtHg + was achieved on a RP C18 monolithic column. ► The hyphenated system provided higher sample throughput compared to HPLC–CV/AFS. ► The limits of detection for mercury species were comparable or better than those reported by HPLC–CV/AFS. ► The developed method also provided low instrumental and operational costs. - Abstract: In this paper, a novel automatic approach for the speciation of inorganic mercury (Hg 2+ ), methylmercury (MeHg + ) and ethylmercury (EtHg + ) using multisyringe chromatography (MSC) coupled to cold-vapor atomic fluorescence spectrometry (CV/AFS) was developed. For the first time, the separation of mercury species was accomplished on a RP C18 monolithic column using a multi-isocratic elution program. The elution protocol involved the use of 0.005% 2-mercapthoethanol in 240 mM ammonium acetate (pH 6)–acetonitrile (99:1, v/v), followed by 0.005% 2-mercapthoethanol in 240 mM ammonium acetate (pH 6)–acetonitrile (90:10, v/v). The eluted mercury species were then oxidized under post-column UV radiation and reduced using tin(II) chloride in an acidic medium. Subsequently, the generated mercury metal were separated from the reaction mixture and further atomized in the flame atomizer and detected by AFS. Under the optimized experimental conditions, the limits of detection (3σ) were found to be 0.03, 0.11 and 0.09 μg L −1 for MeHg + , Hg 2+ and EtHg + , respectively. The relative standard deviation (RSD, n = 6) of the peak height for 3, 6 and 3 μg L −1 of MeHg + , Hg 2+ and EtHg + (as Hg) ranged from 2.4 to 4.0%. Compared with the conventional HPLC–CV/AFS hyphenated systems

X-ray Fluorescence Holography: Principles, Apparatus, and Applications

Science.gov (United States)

Hayashi, Kouichi; Korecki, Pawel

2018-06-01

X-ray fluorescence holography (XFH) is an atomic structure determination technique that combines the capabilities of X-ray diffraction and X-ray fluorescence spectroscopy. It provides a unique means of gaining fully three-dimensional information about the local atomic structure and lattice site positions of selected elements inside compound samples. In this work, we discuss experimental and theoretical aspects that are essential for the efficient recording and analysis of X-ray fluorescence holograms and review the most recent advances in XFH. We describe experiments performed with brilliant synchrotron radiation as well as with tabletop setups that employ conventional X-ray tubes.

Determination of uranium in seawater by fluorescence spectrometry

International Nuclear Information System (INIS)

Kawashima, Toshi; Kawakubo, Senkichi; Minegishi, Hisako.

1984-01-01

A Fluorescence spectrometry for the determination of uranium in seawater has been developed. Anion exchange separation of uranium from seawater followed by preparation of NaF-carbonate cake and by spectrometry for ultraviolet ray excited fluorescence of uranium on the fluoride host provide the trace determinaton of uranium at the subnano gram level. Anion exchange behavior, excitation-emission behavior of the uranium on the host and effects of foreign ions to the fluorescence have been presented. Appling the method to 1 ml of seawater 3 ppb of uranium has been determined. (author)

[Atomic/ionic fluorescence in microwave plasma torch discharge excited by high current microsecond pulsed hollow cathode lamp-europium atomic/ionic fluorescence spectrometry].

Science.gov (United States)

Gong, Z; Liang, F; Yang, P; Jin, Q; Huang, B

1999-06-01

Eu atomic and ionic fluorescence spectrometry in microwave plasma torch discharge excited by high current microsecond pulsed hollow cathode lamp (HCMP HCL-MPT AFS/IFS) was studied. Operating conditions were optimized. The best detection limits for AFS and IFS obtained with a desolvated ultrasonic nebulization system were 42.0 ng/mL for Eu I 462.7 nm and 21.8 ng/mL for Eu II 381.97 nm, respectively, both were better than those given by the instruction manual of a Baird ICP AFS-2000 spectrometer using pneumatic concentric nebulizer with desolvation for AFS, but were significantly higher than those obtained by using the Baird spectrometer with a mini-monochromator and a ultrasonic nebulzer system.

Determination of methyl mercury by aqueous phase Eehylation, followed by gas chromatographic separation with cold vapor atomic fluorescence detection

Science.gov (United States)

De Wild, John F.; Olsen, Mark L.; Olund, Shane D.

2002-01-01

A recent national sampling of streams in the United States revealed low methyl mercury concentrations in surface waters. The resulting median and mean concentrations, calculated from 104 samples, were 0.06 nanograms per liter (ng/L) and 0.15 ng/L, respectively. This level of methyl mercury in surface water in the United States has created a need for analytical techniques capable of detecting sub-nanogram per liter concentrations. In an attempt to create a U.S. Geological Survey approved method, the Wisconsin District Mercury Laboratory has adapted a distillation/ethylation/ gas-phase separation method with cold vapor atomic fluorescence spectroscopy detection for the determination of methyl mercury in filtered and unfiltered waters. This method is described in this report. Based on multiple analyses of surface water and ground-water samples, a method detection limit of 0.04 ng/L was established. Precision and accuracy were evaluated for the method using both spiked and unspiked ground-water and surface-water samples. The percent relative standard deviations ranged from 10.2 to 15.6 for all analyses at all concentrations. Average recoveries obtained for the spiked matrices ranged from 88.8 to 117 percent. The precision and accuracy ranges are within the acceptable method-performance limits. Considering the demonstrated detection limit, precision, and accuracy, the method is an effective means to quantify methyl mercury in waters at or below environmentally relevant concentrations

Fluorescent silver nanoclusters for ultrasensitive determination of chromium(VI) in aqueous solution

International Nuclear Information System (INIS)

Zhang, Jian Rong; Zeng, Ai Lian; Luo, Hong Qun; Li, Nian Bing

2016-01-01

Highlights: • Fluorescent Ag nanoclusters were first applied to Cr(VI) detection. • The proposed method is simple, rapid, and environmentally friendly. • The sensor shows a wide linear range, low detection limit, and good selectivity. • The system can also be used for the indirect assay of total chromium and Cr(III). • The analyses in real water samples are satisfactory. - Abstract: In this work, a simple and sensitive Cr(VI) sensor is proposed based on fluorescent polyethyleneimine-stabilized Ag nanoclusters, which allows the determination over a wide concentration range of 0.1 nM–3.0 μM and with a detection limit as low as 0.04 nΜ and a good selectivity. The quenching mechanism was discussed in terms of the absorption and fluorescence spectra, suggesting that Cr(VI) is connected to Ag nanoclusters by hydrogen bond between the oxygen atom at the vertex of tetrahedron structure of Cr(VI) and the amino nitrogen of polyethyleneimine that surrounded Ag nanoclusters and electron transfer from Ag nanoclusters to highly electron-deficient Cr(VI) results in fluorescence quenching. Despite the failure to quench the fluorescence efficiently, Cr(III) can also be measured using the proposed Ag nanoclusters by being oxidized to Cr(VI) in alkaline solution (pH ∼9) containing H 2 O 2 . Therefore, our approach could be used to detect Cr(VI), Cr(III) and the total chromium level in aqueous solution. In addition, Cr(VI) analysis in real water samples were satisfactory, indicating this method could be practically promising for chromium measurements.

Nanoscale orientation and lateral organization of chimeric metal-binding green fluorescent protein on lipid membrane determined by epifluorescence and atomic force microscopy

International Nuclear Information System (INIS)

Prachayasittikul, Virapong; Isarankura Na Ayudhya, Chartchalerm; Tantimongcolwat, Tanawut; Galla, Hans-Joachim

2005-01-01

Epifluorescence microscopy as well as atomic force microscopy was successfully applied to explore the orientation and lateral organization of a group of chimeric green fluorescent proteins (GFPs) on lipid membrane. Incorporation of the chimeric GFP carrying Cd-binding region (His6CdBP4GFP) to the fluid phase of DPPC monolayer resulted in a strong fluorescence intensity at the air-water interface. Meanwhile, non-specific adsorption of the GFP having hexahistidine (His6GFP) led to the perturbation of the protein structure in which very low fluorescence was observed. Specific binding of both of the chimeric GFPs to immobilized zinc ions underneath the metal-chelating lipid membrane was revealed. This specific binding could be reversibly controlled by addition of metal ions or metal chelator. Binding of the chimeric GFPs to the metal-chelating lipid membrane was proven to be the end-on orientation while the side-on adsorption was contrarily noted in the absence of metal ions. Increase of lateral mobility owing to the fluidization effect on the chelating lipid membrane subsequently facilitated crystal formation. All these findings have opened up a potential approach for a specific orientation of immobilization of protein at the membrane interface. This could have accounted for a better opportunity of sensor development

Determination of copper (II) in foodstuffs based on its quenching effect on the fluorescence of N,N'-bis(pyridoxal phosphate)-o-phenylenediamine.

Science.gov (United States)

Xu, Canhui; Liao, Lifu; He, Yunfei; Wu, Rurong; Li, Shijun; Yang, Yanyan

2015-01-01

A Schiff base-type fluorescence probe was prepared for the detection of copper (II) in foodstuffs. The probe is N,N'-bis(pyridoxal phosphate)-o-phenylenediamine (BPPP). It was synthesized by utilizing the Schiff base condensation reaction of pyridoxal 5-phosphate with 1,2-phenylenediamine. BPPP has the properties of high fluorescence stability, good water solubility and low toxicity. Its maximum excitation wavelength and maximum fluorescence emission wavelength are at 389 and 448 nm, respectively. When BPPP coexists with copper (II), its fluorescence is dramatically quenched. Under a certain condition, the fluorescence intensity decreased proportionally to the concentration of copper (II) by the quenching effect. Based on this fact, we established a fluorescence quenching method for the determination of copper (II). Under optimal conditions a linear range was found to be 0.5-50 ng/mL with a detection limit of 0.2 ng/mL. The method has been applied to determine copper (II) in foodstuff samples and the analytical results show good agreement with that obtained from atomic absorption spectrometry method. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of K shell absorption jump factors and jump ratios of 3d transition metals by measuring K shell fluorescence parameters

International Nuclear Information System (INIS)

Kaçal, Mustafa Recep; Han, İbrahim; Akman, Ferdi

2015-01-01

Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring K-shell absorption jump factors and jump ratios for Ti, Cr, Fe, Co, Ni and Cu elements. The jump factors and jump ratios for these elements were determined by measuring K shell fluorescence parameters such as the Kα X-ray production cross-sections, K shell fluorescence yields, Kβ-to-Kα X-rays intensity ratios, total atomic absorption cross sections and mass attenuation coefficients. The measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation and transmission experimental geometry. The measured values for jump factors and jump ratios were compared with theoretically calculated and the ones available in the literature. - Highlights: • This work regard the K shell absorption jump ratios and jump factors of Ti, Cr, Fe, Co, Ni and Cu. • This paper presents the first measurement of these parameters using the experimental K shell fluorescence parameters. • A good agreement was found between experimental and theoretical values. • The EDXRF technique was suitable, precise and reliable for the measurement of these atomic parameters

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

Czech Academy of Sciences Publication Activity Database

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

2014-01-01

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

X-ray fluorescence/Auger-electron coincidence spectroscopy of vacancy cascades in atomic argon

International Nuclear Information System (INIS)

Arp, U.

1996-01-01

Argon L 2.3 -M 2.3 M 2.3 Auger-electron spectra were measured in coincidence with Kα fluorescent x-rays in studies of Ar K-shell vacancy decays at several photon energies above the K-threshold and on the 1s-4p resonance in atomic argon. The complex spectra recorded by conventional electron spectroscopy are greatly simplified when recorded in coincidence with fluorescent x-rays, allowing a more detailed analysis of the vacancy cascade process. The resulting coincidence spectra are compared with Hartree-Fock calculations which include shake-up transitions in the resonant case. Small energy shifts of the coincidence electron spectra are attributed to post-collision interaction with 1s photoelectrons

The determination, by x-ray-fluorescence spectrometry, of gold and uranium on resin

International Nuclear Information System (INIS)

Jacobs, J.J.; Balaes, A.M.E.

1983-01-01

The problems encountered in the determination of gold and uranium that are present simultaneously in a sample of resin were considered, and new background positions, as well as correction factors for background lift and partial spectral overlap, were determined for use in the X-ray-fluorescence measurement of these elements. The agreement between the results obtained by the use of the X-ray-fluorescence method and those obtained by atomic-absorption spectrophotometry were found to be satisfactory. The relative standard deviation in the former measurements is 0,005 at a concentration of 1000 p.p.m., and the working range of the calibrations is 15 to 1000 p.p.m. These limits can be extended by further dilution of the sample. The limits of determination are 6 p.p.m. in the briquette prepared from a sample of resin and 18 p.p.m. in the sample when the maximum mass of the sample is 3 g. The procedure is intended primarily for use in the rapid determination of gold and uranium when no analyses for other elements are required. The time taken for the analysis is 2 hours for 10 samples when 6 standards are used. A computer programme that was developed for the processing of the data is appended as part of a laboratory method

Femtosecond, two-photon laser-induced-fluorescence imaging of atomic oxygen in an atmospheric-pressure plasma jet

Science.gov (United States)

Schmidt, Jacob B.; Sands, Brian L.; Kulatilaka, Waruna D.; Roy, Sukesh; Scofield, James; Gord, James R.

2015-06-01

Femtosecond, two-photon-absorption laser-induced-fluorescence (fs-TALIF) spectroscopy is employed to measure space- and time-resolved atomic-oxygen distributions in a nanosecond, repetitively pulsed, externally grounded, atmospheric-pressure plasma jet flowing helium with a variable oxygen admixture. The high-peak-intensity, low-average-energy femtosecond pulses result in increased TALIF signal with reduced photolytic inferences. This allows 2D imaging of absolute atomic-oxygen number densities ranging from 5.8   ×   1015 to 2.0   ×   1012cm-3 using a cooled CCD with an external intensifier. Xenon is used for signal and imaging-system calibrations to quantify the atomic-oxygen fluorescence signal. Initial results highlight a transition in discharge morphology from annular to filamentary, corresponding with a change in plasma chemistry from ozone to atomic oxygen production, as the concentration of oxygen in the feed gas is changed at a fixed voltage-pulse-repetition rate. In this configuration, significant concentrations of reactive oxygen species may be remotely generated by sustaining an active discharge beyond the confines of the dielectric capillary, which may benefit applications that require large concentrations of reactive oxygen species such as material processing or biomedical devices.

A new atomization cell for trace metal determinations by tungsten coil atomic spectrometry

Energy Technology Data Exchange (ETDEWEB)

Donati, G.L., E-mail: georgedonati@yahoo.com.br [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States); Wildman, R.B.; Jones, B.T. [Department of Chemistry, Wake Forest University, Winston-Salem, NC 27109 (United States)

2011-02-28

A new metallic atomization cell is used for trace metal determinations by tungsten coil atomic absorption spectrometry and tungsten coil atomic emission spectrometry. Different protecting gas mixtures are evaluated to improve atomic emission signals. Ar, N{sub 2}, CO{sub 2} and He are used as solvents, and H{sub 2} and C{sub 2}H{sub 2} as solutes. A H{sub 2}/Ar mixture provided the best results. Parameters such as protecting gas flow rate and atomization current are also optimized. The optimal conditions are used to determine the figures of merit for both methods and the results are compared with values found in the literature. The new cell provides a better control of the radiation reaching the detector and a small, more isothermal environment around the atomizer. A more concentrated atomic cloud and a smaller background signal result in lower limits of detection using both methods. Cu (324.7 nm), Cd (228.8 nm) and Sn (286.3 nm) determined by tungsten coil atomic absorption spectrometry presented limits of detection as low as 0.6, 0.1, and 2.2 {mu}g L{sup -1}, respectively. For Cr (425.4 nm), Eu (459.4 nm) and Sr (460.7 nm) determined by tungsten coil atomic emission spectrometry, limits of detection of 4.5, 2.5, and 0.1 {mu}g L{sup -1} were calculated. The method is used to determine Cu, Cd, Cr and Sr in a water standard reference material. Results for Cu, Cd and Cr presented no significant difference from reported values in a 95% confidence level. For Sr, a 113% recovery was obtained.

Applicability of multisyringe chromatography coupled to cold-vapor atomic fluorescence spectrometry for mercury speciation analysis

Energy Technology Data Exchange (ETDEWEB)

Guzman-Mar, J.L.; Hinojosa-Reyes, L. [Department of Chemistry Sciences, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, Pedro de Alba s/n, C.P. 66451 San Nicolas de los Garza, Nuevo Leon (Mexico); Serra, A.M. [Department of Chemistry, University of the Balearic Islands, E-07122 Palma de Mallorca (Spain); Hernandez-Ramirez, A. [Department of Chemistry Sciences, Universidad Autonoma de Nuevo Leon, Cd. Universitaria, Pedro de Alba s/n, C.P. 66451 San Nicolas de los Garza, Nuevo Leon (Mexico); Cerda, V., E-mail: victor.cerda@uib.es [Department of Chemistry, University of the Balearic Islands, E-07122 Palma de Mallorca (Spain)

2011-12-05

Graphical abstract: An automatic system, based on the applicability of multisyringe chromatography (MSC) coupled to cold-vapor atomic fluorescence spectrometry (CV/AFS) detection is developed for mercury speciation. Highlights: Black-Right-Pointing-Pointer The on-line coupling of MSC to CV/AFS was developed for mercury speciation analysis. Black-Right-Pointing-Pointer The speciation of MeHg{sup +}, Hg{sup 2+} and EtHg{sup +} was achieved on a RP C18 monolithic column. Black-Right-Pointing-Pointer The hyphenated system provided higher sample throughput compared to HPLC-CV/AFS. Black-Right-Pointing-Pointer The limits of detection for mercury species were comparable or better than those reported by HPLC-CV/AFS. Black-Right-Pointing-Pointer The developed method also provided low instrumental and operational costs. - Abstract: In this paper, a novel automatic approach for the speciation of inorganic mercury (Hg{sup 2+}), methylmercury (MeHg{sup +}) and ethylmercury (EtHg{sup +}) using multisyringe chromatography (MSC) coupled to cold-vapor atomic fluorescence spectrometry (CV/AFS) was developed. For the first time, the separation of mercury species was accomplished on a RP C18 monolithic column using a multi-isocratic elution program. The elution protocol involved the use of 0.005% 2-mercapthoethanol in 240 mM ammonium acetate (pH 6)-acetonitrile (99:1, v/v), followed by 0.005% 2-mercapthoethanol in 240 mM ammonium acetate (pH 6)-acetonitrile (90:10, v/v). The eluted mercury species were then oxidized under post-column UV radiation and reduced using tin(II) chloride in an acidic medium. Subsequently, the generated mercury metal were separated from the reaction mixture and further atomized in the flame atomizer and detected by AFS. Under the optimized experimental conditions, the limits of detection (3{sigma}) were found to be 0.03, 0.11 and 0.09 {mu}g L{sup -1} for MeHg{sup +}, Hg{sup 2+} and EtHg{sup +}, respectively. The relative standard deviation (RSD, n = 6) of the

Simultaneous determination of glycols based on fluorescence anisotropy

International Nuclear Information System (INIS)

Garcia Sanchez, F.; Navas Diaz, A.; Lopez Guerrero, M.M.

2007-01-01

Simultaneous determination of non-fluorescent glycols in mixtures without separation or chemical transformation steps is described. Two methods based in the measure of fluorescence anisotropy of a probe such as fluorescein dissolved in the analyte or analyte mixtures are described. In the first method, the anisotropy spectra of pure and mixtures of analytes are used to quantitative determination (if the fluorophor concentration is in a range where fluorescence intensity is proportional to concentration). In the second method, a calibration curve anisotropy-concentration based on the application of the Perrin equation is established. The methods presented here are capable of directly resolving binary mixtures of non-fluorescent glycols on the basis of differences on the fluorescence anisotropy of a fluorescence tracer. Best analytical performances were obtained by application of the method based on Perrin equation. This method is simple, rapid and allows the determination of mixtures of glycols with reasonable accuracy and precision. Detection limits are limited by the quantum yield and anisotropy values of the tracer in the solvents. Recovery values are related to the differences in anisotropy values of the tracer in the pure solvents. Mixtures of glycerine/ethylene glycol (GL/EG), ethylene glycol/1,2-propane diol (EG/1,2-PPD) and polyethylene glycol 400/1,2-propane diol (PEG 400/1,2-PPD) were analysed and recovery values are within 95-120% in the Perrin method. Relative standard deviation are in the range 1.3-2.9% and detection limits in the range 3.9-8.9%

Determination of thiomersal by flow injection coupled with microwave-assisted photochemical online oxidative decomposition of organic mercury and cold vapor atomic fluorescence spectroscopy

International Nuclear Information System (INIS)

Campanella, Beatrice; Onor, Massimo; Mascherpa, Marco Carlo; D’Ulivo, Alessandro; Ferrari, Carlo; Bramanti, Emilia

2013-01-01

Graphical abstract: -- Highlights: •Thiomersal was determined on line using FI-MW/UV-CVGAFS. •MW/UV allows a “green” on line oxidation of organic mercury to Hg II . •Each measure requires less than 5 min with a LOD of 3 ng mL −1 (as mercury). •Hg concentration in commercial ophthalmic solutions ranges between 7.5 and 59.0 μg mL −1 . -- Abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C 9 H 9 HgNaO 2 S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97 ± 3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH 4 solution, and AFS detection in an Ar/H 2 miniaturized flame. The method was linear in the 0.01–2 μg mL −1 range, with a LOD of 0.003 μg mL −1 . This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL −1

Determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization

International Nuclear Information System (INIS)

Usenko, S.I.; Prorok, M.M.

1992-01-01

A method of direct determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization was developed. Concomitant elements Si, K, Mg, Na, present in natural waters in the concentration of 0.05-100 mg/cv 3 , do not produce effect on the value of boron atomic absorption. Boron determination limit constituted 0.02 mg/cm 3 for 25 ml of solution introduced

Ultratrace determination of tin by hydride generation in-atomizer trapping atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Průša, Libor [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Charles University in Prague, Faculty of Science, Department of Analytical Chemistry, Hlavova 8, Prague 2, CZ 128 43 Czech Republic (Czech Republic); Dědina, Jiří [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic); Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz [Institute of Analytical Chemistry of the ASCR, v. v. i., Veveří 97, 602 00 Brno (Czech Republic)

2013-12-04

Graphical abstract: -- Highlights: •In-atomizer trapping HG-AAS was optimized for Sn. •A compact quartz trap-and-atomizer device was employed. •Generation, preconcentration and atomization steps were investigated in detail. •Hundred percent preconcentration efficiency for tin was reached. •Routine analytical method was developed for Sn determination (LOD of 0.03 ng mL{sup −1} Sn). -- Abstract: A quartz multiatomizer with its inlet arm modified to serve as a trap (trap-and-atomizer device) was employed to trap tin hydride and subsequently to volatilize collected analyte species with atomic absorption spectrometric detection. Generation, atomization and preconcentration conditions were optimized and analytical figures of merit of both on-line atomization as well as preconcentration modes were quantified. Preconcentration efficiency of 95 ± 5% was found. The detection limits reached were 0.029 and 0.14 ng mL{sup −1} Sn, respectively, for 120 s preconcentration period and on-line atomization mode without any preconcentration. The interference extent of other hydride forming elements (As, Se, Sb and Bi) on tin determination was found negligible in both modes of operation. The applicability of the developed preconcentration method was verified by Sn determination in a certified reference material as well as by analysis of real samples.

X-ray fluorescence determination of composition of the high temperature superconductors by the fundamental parameter method

International Nuclear Information System (INIS)

Mao Zhenwei; Shi Lei; Chen Shuyu; Zhou Guien

2001-01-01

Y, Pr, Ba and Cu compositions of the series of the Y 1-x Pr x Ba 2 Cu 3 O y samples have been determined by using X-ray fluorescence (XRF) fundamental parameter method in a non-destruction state. The composition is given by an atomic fraction. The determined compositions of the samples show a difference from their nominal compositions. One of the reasons why the exact shape of T c vs x varies is different from group to group, as reported, is the difference of the real and the nominal compositions. The relation of T c vs x is not a simple quadric curve. The results agree well with those obtained by the inductively coupled plasma atomic emission spectrometer (ICP-AES), which indicates that the method is appropriate for the determination of the compositions of the high temperature superconductors. In addition, the influence of oxygen on analytical elements is discussed. The fraction of the matrix total mass absorption, which is associated with oxygen for each analytical line, is less than 3.41%

Determination of dopant atomic positions with kinematical X-ray standing waves; Untersuchung von Fremdatomen in kristallinen Materialien mit kinematischen stehenden Roentgenwellen

Energy Technology Data Exchange (ETDEWEB)

Walz, Bente

2011-11-15

Recent advances in the kinematic X-ray standing wave technique (KXSW) for the determination of the atomic coordinates and displacement parameters in nonperfect crystalline materials are described in this thesis. The methodology has been improved by considering three significant aspects: - the inclusion of weak multiple beam contributions - the excitation of secondary fluorescence in multiple-element samples - the influence of the crystal mosaicity on the fluorescence yield. The improvements allowed to successfully apply the method to investigate complex oxide materials of current interest for potential device applications. The thermally-induced interdiffusion of cobalt and manganese thin films on zinc oxide single crystals has been studied to determine which lattice sites are occupied preferentially. The data analysis revealed that after thermal diffusion the adsorbed atoms occupied zinc sites in the host lattice. The mean deviation of the cobalt atomic position from the zinc lattice site was comparable to the thermal displacement parameter of the zinc atoms. In the case of manganese a secondary phase was found on the surface. Measurements performed on LaSrMnO{sub 4} provided new insight concerning the rotation of the oxygen octahedron around the manganese atoms and the concomitant displacements of the strontium and lanthanum atoms. It was found that the oxygen octahedra are rotated around the [100]-direction by 4,5 . The measurements in transmission geometry performed on titanium dioxide (rutile) demonstrated that KXSW measurements in the Laue geometry is a viable technique. By performing KXSW under grazing-incidence conditions it is possible to achieve depth resolution. The results clearly show that the extended KXSW technique is a versatile method for characterizing complex material systems. (orig.)

Stratum corneum lipid organization as observed by atomic force, confocal and two-photon excitation fluorescence microscopy

DEFF Research Database (Denmark)

Norlén, Lars; Plasencia Gil, Maria Inés; Bagatolli, Luis

2008-01-01

-related biophysical techniques (e.g. atomic force microscopy and confocal/two-photon excitation fluorescence microscopy), it was recently shown that reconstituted membranes composed of extracted decontaminated human stratum corneum lipids do not form a fluid phase, but exclusively a single-gel phase that segregates...

Advanced Spectral Library (ASTRAL): Atomic Fluorescence in Cool, Evolved Stars

Science.gov (United States)

Carpenter, Ken G.; Nielsen, Krister E.; Kober, Gladys V.; Rau, Gioia

2018-01-01

The "Advanced Spectral Library (ASTRAL) Project: Cool Stars" (PI = T. Ayres) collected a definitive set of representative, high-resolution (R~46,000 in the FUV up to ~1700 Å, R~30,000 for 1700-2150 Å, and R~114,000 >2150 Å) and high signal/noise (S/N>100) UV spectra of eight F-M evolved cool stars. These extremely high-quality STIS UV echelle spectra are available from the HST archive and from the Univ. of Colorado (http://casa.colorado.edu/~ayres/ASTRAL/) and will enable investigations of a broad range of problems -- stellar, interstellar, and beyond -- for many years. In this paper, we extend our study of the very rich emission-line spectra of the four evolved K-M stars in the sample, Beta Gem (K0 IIIb), Gamma Dra (K5 III), Gamma Cru (M3.4 III), and Alpha Ori (M2 Iab), to study the atomic fluorescence processes operating in their outer atmospheres. We summarize the pumping transitions and fluorescent line products known on the basis of previous work (e.g. Carpenter 1988, etc.) and newly identified in our current, on-going analysis of these extraordinary ASTRAL STIS spectra.

Determination of K shell absorption jump factors and jump ratios of 3d transition metals by measuring K shell fluorescence parameters.

Science.gov (United States)

Kaçal, Mustafa Recep; Han, İbrahim; Akman, Ferdi

2015-01-01

Energy dispersive X-ray fluorescence technique (EDXRF) has been employed for measuring K-shell absorption jump factors and jump ratios for Ti, Cr, Fe, Co, Ni and Cu elements. The jump factors and jump ratios for these elements were determined by measuring K shell fluorescence parameters such as the Kα X-ray production cross-sections, K shell fluorescence yields, Kβ-to-Kα X-rays intensity ratios, total atomic absorption cross sections and mass attenuation coefficients. The measurements were performed using a Cd-109 radioactive point source and an Si(Li) detector in direct excitation and transmission experimental geometry. The measured values for jump factors and jump ratios were compared with theoretically calculated and the ones available in the literature. Copyright © 2014 Elsevier Ltd. All rights reserved.

Direct determination of arsenic in soil samples by fast pyrolysis–chemical vapor generation using sodium formate as a reductant followed by nondispersive atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Duan, Xuchuan; Zhang, Jingya; Bu, Fanlong

2015-09-01

This new study shows for the first time that sodium formate can react with trace arsenic to form volatile species via fast pyrolysis – chemical vapor generation. We found that the presence of thiourea greatly enhanced the generation efficiency and eliminated the interference of copper. We studied the reaction temperature, the volume of sodium formate, the reaction acidity, and the carried argon rate using nondispersive atomic fluorescence spectrometry. Under optimal conditions of T = 500 °C, the volumes of 30% sodium formate and 10% thiourea were 0.2 ml and 0.05 ml, respectively. The carrier argon rate was 300 ml min{sup −1} and the detection limit and precision of arsenic were 0.39 ng and 3.25%, respectively. The amount of arsenic in soil can be directly determined by adding trace amount of hydrochloric acid as a decomposition reagent without any sample pretreatment. The method was successfully applied to determine trace amount of arsenic in two soil-certified reference materials (GBW07453 and GBW07450), and the results were found to be in agreement with certified reference values. - Highlights: • Sodium formate can react with trace arsenic to form volatile species via pyrolysis–chemical vapor generation. • Thiourea can enhance the generation efficiency and eliminate the interference of copper. • Arsenic in soil Sample can be directly determined without sample pretreatment.

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

Determination of thiomersal by flow injection coupled with microwave-assisted photochemical online oxidative decomposition of organic mercury and cold vapor atomic fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Campanella, Beatrice; Onor, Massimo; Mascherpa, Marco Carlo; D’Ulivo, Alessandro [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ferrari, Carlo [National Research Council of Italy, C.N.R., Istituto Nazionale di Ottica, INO–UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Bramanti, Emilia, E-mail: bramanti@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Istituto di Chimica dei Composti Organo Metallici-ICCOM-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

2013-12-04

Graphical abstract: -- Highlights: •Thiomersal was determined on line using FI-MW/UV-CVGAFS. •MW/UV allows a “green” on line oxidation of organic mercury to Hg{sup II}. •Each measure requires less than 5 min with a LOD of 3 ng mL{sup −1} (as mercury). •Hg concentration in commercial ophthalmic solutions ranges between 7.5 and 59.0 μg mL{sup −1}. -- Abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C{sub 9}H{sub 9}HgNaO{sub 2}S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97 ± 3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH{sub 4} solution, and AFS detection in an Ar/H{sub 2} miniaturized flame. The method was linear in the 0.01–2 μg mL{sup −1} range, with a LOD of 0.003 μg mL{sup −1}. This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL{sup −1}.

Behaviour of atomic oxygen in a pulsed dielectric barrier discharge measured by laser-induced fluorescence

International Nuclear Information System (INIS)

Ono, Ryo; Yamashita, Youta; Takezawa, Kei; Oda, Tetsuji

2005-01-01

Atomic oxygen is measured in a pulsed dielectric barrier discharge (DBD) using two-photon absorption laser-induced fluorescence (TALIF). The ground-level atomic oxygen is excited to the 3p 3 P state by two-photon absorption at 226 nm. Negative (-40 kV) or positive (+30 kV) pulsed DBD occurs in an O 2 -N 2 mixture at atmospheric pressure. The pulse width of the DBD current is approximately 50 ns. The TALIF experiment shows that the decay rate of atomic oxygen increases linearly with O 2 concentration. This result proves that atomic oxygen decays mainly by the third-body reaction, O + O 2 + M → O 3 + M. The rate coefficient of the third-body reaction is estimated to be 2.2 x 10 -34 cm 6 s -1 in the negative DBD and 0.89 x 10 -34 cm 6 s -1 in the positive DBD. It is shown that the decay rate of atomic oxygen increases linearly with humidity. This can explain the well-known fact that ozone production in DBD is suppressed by increasing humidity

Two-photon laser-induced fluorescence studies of HS radicals, DS radicals, and I atoms

Energy Technology Data Exchange (ETDEWEB)

Tiee, J J; Ferris, M J; Loge, G W; Wampler, F B

1983-04-15

A two-photon laser-induced excitation and fluorescence technique has been used to study the A /sup 2/..sigma../sup +/ - X/sup 2/PI transition of HS and DS radicals and various high-lying /sup 4/P/sup 0/, /sup 2/D/sup 0/, and /sup 4/D/sup 0/ states of the I atom. The two-photon excitation cross sections and detection sensitivity are discussed. 13 references, 5 figures.

Distribution of Fe atom density in a dc magnetron sputtering plasma source measured by laser-induced fluorescence imaging spectroscopy

Science.gov (United States)

Shibagaki, K.; Nafarizal, N.; Sasaki, K.; Toyoda, H.; Iwata, S.; Kato, T.; Tsunashima, S.; Sugai, H.

2003-10-01

Magnetron sputtering discharge is widely used as an efficient method for thin film fabrication. In order to achieve the optimized fabrication, understanding of the kinetics in plasmas is essential. In the present work, we measured the density distribution of sputtered Fe atoms using laser-induced fluorescence imaging spectroscopy. A dc magnetron plasma source with a Fe target was used. An area of 20 × 2 mm in front of the target was irradiated by a tunable laser beam having a planar shape. The picture of laser-induced fluorescence on the laser beam was taken using an ICCD camera. In this way, we obtained the two-dimensional image of the Fe atom density. As a result, it has been found that the Fe atom density observed at a distance of several centimeters from the target is higher than that adjacent to the target, when the Ar gas pressure was relatively high. It is suggested from this result that some gas-phase production processes of Fe atoms are available in the plasma. This work has been performed under the 21st Century COE Program by the Ministry of Education, Culture, Sports, Science and Technology in Japan.

Correlated Fluorescence-Atomic Force Microscopy Studies of the Clathrin Mediated Endocytosis in SKMEL Cells

Science.gov (United States)

Smith, Steve; Hor, Amy; Luu, Anh; Kang, Lin; Scott, Brandon; Bailey, Elizabeth; Hoppe, Adam

Clathrin-mediated endocytosis is one of the central pathways for cargo transport into cells, and plays a major role in the maintenance of cellular functions, such as intercellular signaling, nutrient intake, and turnover of plasma membrane in cells. The clathrin-mediated endocytosis process involves invagination and formation of clathrin-coated vesicles. However, the biophysical mechanisms of vesicle formation are still debated. We investigate clathrin vesicle formation mechanisms through the utilization of tapping-mode atomic force microscopy for high resolution topographical imaging in neutral buffer solution of unroofed cells exposing the inner membrane, combined with fluorescence imaging to definitively label intracellular constituents with specific fluorescent fusion proteins (actin filaments labeled with green phalloidin-antibody and clathrin coated vesicles with the fusion protein Tq2) in SKMEL (Human Melanoma) cells. Results from our work are compared against dynamical polarized total internal fluorescence (TIRF), super-resolution photo-activated localization microscopy (PALM) and transmission electron microscopy (TEM) to draw conclusions regarding the prominent model of vesicle formation in clathrin-mediated endocytosis. Funding provided by NSF MPS/DMR/BMAT award # 1206908.

The determination of major and some minor constituents in lead zirconate-titanate compositions by x-ray fluorescence and atomic absorption spectrometry

NARCIS (Netherlands)

van Willigen, J.H.H.G.; Kruidhof, H.; Dahmen, E.A.M.F.

1972-01-01

An accurate X-ray fluorescence spectrometric method is described for the determination of lead, zirconium and titanium in lead zirconate-titanate ceramics. Careful matching of samples and standards by a borax fusion method resulted in a relative standard deviation of about 0.2% for the major

Behaviour of atomic oxygen in a pulsed dielectric barrier discharge measured by laser-induced fluorescence

Energy Technology Data Exchange (ETDEWEB)

Ono, Ryo [High Temperature Plasma Center, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 227-8568 (Japan); Yamashita, Youta [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Takezawa, Kei [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Oda, Tetsuji [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan)

2005-08-21

Atomic oxygen is measured in a pulsed dielectric barrier discharge (DBD) using two-photon absorption laser-induced fluorescence (TALIF). The ground-level atomic oxygen is excited to the 3p {sup 3}P state by two-photon absorption at 226 nm. Negative (-40 kV) or positive (+30 kV) pulsed DBD occurs in an O{sub 2}-N{sub 2} mixture at atmospheric pressure. The pulse width of the DBD current is approximately 50 ns. The TALIF experiment shows that the decay rate of atomic oxygen increases linearly with O{sub 2} concentration. This result proves that atomic oxygen decays mainly by the third-body reaction, O + O{sub 2} + M {yields} O{sub 3} + M. The rate coefficient of the third-body reaction is estimated to be 2.2 x 10{sup -34} cm{sup 6} s{sup -1} in the negative DBD and 0.89 x 10{sup -34} cm{sup 6} s{sup -1} in the positive DBD. It is shown that the decay rate of atomic oxygen increases linearly with humidity. This can explain the well-known fact that ozone production in DBD is suppressed by increasing humidity.

Simultaneous detection of selenium by atomic fluorescence and sulfur by molecular emission by flow-injection hydride generation with on-line reduction for the determination of selenate, sulfate and sulfite

Energy Technology Data Exchange (ETDEWEB)

Tyson, J.F., E-mail: tyson@chem.umass.edu [Department of Chemistry, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003 (United States); Palmer, C.D. [Lead Poisoning Trace Elements Laboratory, Wadsworth Center, New York State Department of Health, P.O. Box 509, Empire State Plaza, Albany, NY 12201-0509 (United States)

2009-10-12

An inductively coupled plasma atomic fluorescence spectrometry (ICP-AFS) instrument, was modified so that it was capable of monitoring transient chromatographic or flow-injection profiles and that sulfur molecular emission and selenium atomic fluorescence could be monitored simultaneously in an argon-hydrogen diffusion flame on a glass burner. The analytes were introduced as hydrogen selenide and hydrogen sulfide, generated on a flow-injection manifold. Selenate was reduced to hydride-forming selenite by microwave-assisted on-line reaction with hydrochloric acid, and sulfate, or sulfite, was reduced to hydride-forming sulfide by a mixture of hydriodic acid, acetic acid and sodium hypophosphite. The effects of the nature of reducing agent, flow rate, microwave power and coil length were studied. The limit of detection (3 s) for selenium was 10 {mu}g L{sup -1}, and for sulfide was 70 {mu}g L{sup -1} (200-{mu}L injection volume). The calibration was linear for selenium up to 2 mg L{sup -1} and to 10 mg L{sup -1} for sulfide. The throughput was 180 h{sup -1}. The three sulfur species could be differentiated on the basis of reactivity at various microwave powers.

Determination of cobalt in human liver by atomic absorption spectrometry with electrothermal atomization

International Nuclear Information System (INIS)

Caldas, E.D.; Gine-Rosias, M.F.; Dorea, J.G.

1991-01-01

A detailed study of the use of electrothermal atomic absorption spectrometry for the determination of cobalt in human liver is described. Comparisons of sample digestion using nitric acid or nitric acid plus perchloric acid, atomization procedures and the application of palladium and magnesium nitrate chemical modifiers were studied using NBS SRM 1577a Bovine Liver. The best results were achieved with sample decomposition in nitric acid, atomization from the tube wall and no chemical modifier. Cobalt was determined in 90 samples of livers from foetuses and deceased newborns using the standard addition method with an average recovery of 99.8%. (author). 30 refs.; 4 figs.; 2 tabs

Two-photon absorption laser-induced fluorescence of atomic oxygen in the afterglow of pulsed positive corona discharge

Science.gov (United States)

Ono, Ryo; Takezawa, Kei; Oda, Tetsuji

2009-08-01

Atomic oxygen is measured in the afterglow of pulsed positive corona discharge using time-resolved two-photon absorption laser-induced fluorescence. The discharge occurs in a 14 mm point-to-plane gap in dry air. After the discharge pulse, the atomic oxygen density decreases at a rate of 5×104 s-1. Simultaneously, ozone density increases at almost the same rate, where the ozone density is measured using laser absorption method. This agreement between the increasing rate of atomic oxygen and decreasing rate of ozone proves that ozone is mainly produced by the well-known three-body reaction, O+O2+M→O3+M. No other process for ozone production such as O2(v)+O2→O3+O is observed. The spatial distribution of atomic oxygen density is in agreement with that of the secondary streamer luminous intensity. This agreement indicates that atomic oxygen is mainly produced in the secondary streamer channels, not in the primary streamer channels.

Determination of ATP as a fluorescence probe with europium(III)-doxycycline.

Science.gov (United States)

Hou, Faju; Wang, Xiaolei; Jiang, Chongqiu

2005-03-01

A new spectrofluorimetric method has been developed for the determination of adenosine disodium triphosphate (ATP). We studied the interactions between the doxycycline (DC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-visible absorption and fluorescence spectra. Using doxycycline (DC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP could remarkably enhance the fluorescence intensity of the DC-Eu3+ complex at lambda = 612 nm. The enhanced fluorescence intensity of the Eu3+ ion was in proportion to the concentration of ATP. The optimum conditions for the determination of ATP were also investigated. The linear ranges for ATP were 1.00 x 10(-7) - 2.00 x 10(-6) mol L(-1) with detection limits of 4.07 x 10(-8) mol L(-1). This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to the determination of ATP in samples. The mechanism of fluorescence enhancement between the doxycycline (DC)-Eu3+ complex and ATP was also studied.

Production mechanism of atomic nitrogen in atmospheric pressure pulsed corona discharge measured using two-photon absorption laser-induced fluorescence

International Nuclear Information System (INIS)

Teramoto, Yoshiyuki; Ono, Ryo; Oda, Tetsuji

2012-01-01

To study the production mechanism of atomic nitrogen, the temporal profile and spatial distribution of atomic nitrogen are measured in atmospheric pressure pulsed positive corona discharge using two-photon absorption laser-induced fluorescence. The absolute atomic nitrogen density in the streamer filaments is estimated from decay rate of atomic nitrogen in N 2 discharge. The results indicate that the absolute atomic nitrogen density is approximately constant against discharge energy. When the discharge voltage is 21.5 kV, production yield of atomic nitrogen produced by an N 2 discharge pulse is estimated to be 2.9 - 9.8 × 10 13 atoms and the energy efficiency of atomic nitrogen production is estimated to be about 1.8 - 6.1 × 10 16 atoms/J. The energy efficiency of atomic nitrogen production in N 2 discharge is constant against the discharge energy, while that in N 2 /O 2 discharge increases with discharge energy. In the N 2 /O 2 discharge, two-step process of N 2 dissociation plays significant role for atomic nitrogen production.

Determination of trace elements and heavy metals in sediment using x-ray fluorescence

International Nuclear Information System (INIS)

Sidahmed, Muataz Ahmed Ibrahem

2014-01-01

In this study, 30 sediment samples were taken randomly from the area of Suba south of Khartoum state. Trace elements and heavy metal were determined in sediments samples using x-ray fluoresce spectroscopy (X RF). K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were determined by X RF. Standard Reference Material (SRM) from international Atomic Energy Agency (IAEA-Soil-7) has been used to achieve accuracy of X RF method. Measured values were found in agreements with certified values. The average elemental concentrations of K, Ca, Ti, Mn, Fe, Cu, Zn, Pb, Rb, Sr, and Zr were 5882.7, 20703.3, 6264.3, 460.97, 26713.3, 7.7, 43.4, 18.6, 28.6, 144.8, and 173.06, respectively. Correlation between elements was performed also cluster analysis was used to check the similarly between the samples result. The result of study were compared with previous studies and the concentrations of some elements found to be similar.(Author)

Determination of trace cadmium in rice by liquid spray dielectric barrier discharge induced plasma - chemical vapor generation coupled with atomic fluorescence spectrometry

Science.gov (United States)

Liu, Xing; Zhu, Zhenli; Bao, Zhengyu; Zheng, Hongtao; Hu, Shenghong

2018-03-01

Cadmium contamination in rice has become an increasing concern in many countries including China. A simple, cost-effective, and highly sensitive method was developed for the determination of trace cadmium in rice samples based on a new high-efficient liquid spray dielectric barrier discharge induced plasma (LSDBD) vapor generation coupled with atomic fluorescence spectrometry (AFS). The analytical procedure involves the efficient formation of Cd volatile species by LSDBD plasma induced chemical processes without the use of any reducing reagents (Na/KBH4 in conventional hydride generation). The effects of the addition of organic substances, different discharge parameters such as discharge voltage and discharge gap, as well as the foreign ion interferences were investigated. Under optimized conditions, a detection limit of 0.01 μg L- 1 and a precision of 0.8% (RSD, n = 5, 1 μg L- 1 Cd) was readily achieved. The calibration curve was linear in the range between 0.1 and 10 μg L- 1, with a correlation coefficient of R2 = 0.9995. Compared with the conventional acid-BH4- vapor generation, the proposed method not only eliminates the use of unstable and expensive reagents, but also offers high tolerance for coexisting ions, which is well suited to the direct analysis of environmental samples. The validation of the proposed method was demonstrated by the analysis of Cd in reference material of rice (GBW080684). It was also successfully applied to the determination of trace cadmium in locally collected 11 rice samples, and the obtained Cd concentrations are ranged from 7.2 to 517.7 μg kg- 1.

Lasers probe the atomic nucleus

International Nuclear Information System (INIS)

Eastham, D.

1986-01-01

The article is contained in a booklet on the Revised Nuffield Advanced Physics Course, and concentrates on two techniques to illustrate how lasers probe the atomic nucleus. Both techniques employ resonance fluorescence spectroscopy for obtaining atomic transition energies. The first uses lasers to determine the change in the nuclear charge radius with isotope, the second concerns the use of lasers for ultrasensitive detection of isotopes and elements. The application of lasers in resonance ionization spectroscopy and proton decay is also described. (UK)

Laser fluorescence spectroscopy by two-photon excitation for detection of hydrogen atoms in a periphery region of high temperature plasmas

International Nuclear Information System (INIS)

Kim, Hee-Je; Kajiwara, Toshinori; Motoyama, Sumio; Muraoka, Katsunori; Akazaki, Masanori; Okada, Tatsuo; Maeda, Mitsuo

1989-01-01

For measurements of atomic hydrogen density in the periphery region of high temperature plasmas, laser fluorescence spectroscopy (LFS) by two-photon excitation (1s-3s, 3d) was developed. Based upon the theoretical estimates for laser source requirements, which indicated the laser energy and spectral width to be more than 10 mJ (assuming the pulse duration of 10 ns) and several tens of picometers around the wavelength of 205.1 nm, respectively, the first Stokes generation in deuterium gas of ArF laser output was adopted and shown to have the necessary performance. Through the LFS experiment employing the laser source, the minimum detectable limit of atomic hydrogen, normalized by a laser power and an observing solid angle, was demonstrated to be 1 x 10 14 [m -3 · MW · sr], which is usually sufficient for the above purpose, and the accuracy of the density determination was shown to be within a factor 2. (author)

Resonance Fluorescence of a Trapped Four-Level Atom with Bichromatic Driving

International Nuclear Information System (INIS)

Bergou, J.; Jakob, M.; Abranyos, Y.

1999-01-01

The resonance fluorescence spectrum of a bichromatically driven four-level atom is polarization dependent. Very narrow lines occur in the incoherent parts of the spectrum for polarization directions which are different from that of the driving fields. The degree of squeezing has a maximum of 56% which should make it easily observable. The second-order correlation function exhibits anti bunching for zero time delay and strong super bunching for certain values of the interaction parameter and time delay. For these parameters resonant two-photon emission takes place in the form of polarization entangled photon pairs. The system can be a novel source of photons in the EPR and/or Bell states. Some experiments will be proposed which make use of this unique source. (Authors)

A Geant4-based Simulation to Evaluate the Feasibility of Using Nuclear Resonance Fluorescence (NRF) in Determining Atomic Compositions of Body Tissue in Cancer Diagnostics and Irradiation

Science.gov (United States)

Gilbo, Yekaterina; Wijesooriya, Krishni; Liyanage, Nilanga

2017-01-01

Customarily applied in homeland security for identifying concealed explosives and chemical weapons, NRF (Nuclear Resonance Fluorescence) may have high potential in determining atomic compositions of body tissue. High energy photons incident on a target excite the target nuclei causing characteristic re-emission of resonance photons. As the nuclei of each isotope have well-defined excitation energies, NRF uniquely indicates the isotopic content of the target. NRF radiation corresponding to nuclear isotopes present in the human body is emitted during radiotherapy based on Bremsstrahlung photons generated in a linear electron accelerator. We have developed a Geant4 simulation in order to help assess NRF capabilities in detecting, mapping, and characterizing tumors. We have imported a digital phantom into the simulation using anatomical data linked to known chemical compositions of various tissues. Work is ongoing to implement the University of Virginia's cancer center treatment setup and patient geometry, and to collect and analyze the simulation's physics quantities to evaluate the potential of NRF for medical imaging applications. Preliminary results will be presented.

Determination of copper, iron and zinc in spirituous beverages by total reflection X-ray fluorescence spectrometry

Science.gov (United States)

Capote, T.; Marcó, L. M.; Alvarado, J.; Greaves, E. D.

1999-10-01

The concentration of copper in traditional homemade alcoholic distillates produced in Venezuela (Cocuy de Penca) were determined by total reflection X-ray fluorescence (TXRF) using vanadium as internal standard. The results were compared to those obtained by flame atomic absorption spectrometry (FAAS). Three preparative methods of addition of vanadium were compared: classical internal standard addition, 'layer on layer' internal standard addition and in situ addition of internal standard. The TXRF procedures were accurate and the precision was comparable to that obtained by the FAAS technique. Copper levels were above the maximum allowed limits for similar beverages. Zinc and iron in commercial and homemade distilled beverages were also analyzed by TXRF with in situ addition of internal standard demonstrating the usefulness of this technique for trace metal determination in distillates.

William Barlow and the Determination of Atomic Arrangement in Crystals.

Science.gov (United States)

Mauskopf, Seymour H

2015-04-01

William Barlow (1845-1934) was an important if unconventional scientist, known for having developed the 'closest-packing' atomic models of crystal structure. He resumed an early nineteenth-century tradition of utilizing crystallographical and chemical data to determine atomic arrangements in crystals. This essay recounts Barlow's career and scientific activity in three parts: (a) His place in the tradition of determining atomic arrangement in context of this earlier tradition and of contemporaneous developments of crystallography and chemistry, (b) his unconventional career, and (c) the 'success' of his program to determine atomic arrangements in crystals and its influence on the work of William Lawrence Bragg.

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

Determination of mercury species by the diffusive gradient in thin film technique and liquid chromatography – atomic fluorescence spectrometry after microwave extraction

Energy Technology Data Exchange (ETDEWEB)

Pelcová, Pavlína, E-mail: pavlina.pelcova@mendelu.cz; Dočekalová, Hana, E-mail: hana.docekalova@mendelu.cz; Kleckerová, Andrea, E-mail: andrea.kleckerova@mendelu.cz

2015-03-25

Highlights: • DGT–MAE–LC–CV-AFS method was developed for determination of four mercury species. • The microwave extraction was used for isolation of mercury species from resin gels. • Optimized DGT–MAE–LC–CV-AFS method provides low detection limits (13–38 ng L{sup −1}). • The diffusion coefficients of four mercury species were simultaneously determined. - Abstract: A diffusive gradient in thin films technique (DGT) was combined with liquid chromatography (LC) and cold vapor atomic fluorescence spectrometry (CV-AFS) for the simultaneous quantification of four mercury species (Hg{sup 2+}, CH{sub 3}Hg{sup +}, C{sub 2}H{sub 5}Hg{sup +}, and C{sub 6}H{sub 5}Hg{sup +}). After diffusion through an agarose diffusive layer, the mercury species were accumulated in resin gels containing thiol-functionalized ion-exchange resins (Duolite GT73, and Ambersep GT74). A microwave-assisted extraction (MAE) in the presence of 6 M HCl and 5 M HCl (55 °C, 15 min) was used for isolation of mercury species from Ambersep and Duolite resin gels, respectively. The extraction efficiency was higher than 95.0% (RSD 3.5%). The mercury species were separated with a mobile phase containing 6.2% methanol + 0.05% 2-mercaptoethanol + 0.02 M ammonium acetate with a stepwise increase of methanol content up to 80% in the 16th min on a Zorbax C18 reverse phase column. The LODs of DGT–MAE–LC–CV-AFS method were 38 ng L{sup −1} for CH{sub 3}Hg{sup +}, 13 ng L{sup −1} for Hg{sup 2+}, 34 ng L{sup −1} for C{sub 2}H{sub 5}Hg{sup +} and 30 ng L{sup −1} for C{sub 6}H{sub 5}Hg{sup +} for 24 h DGT accumulation at 25 °C.

Techniques of laser spectroscopy in investigations of lanthanides' free atoms and ions

International Nuclear Information System (INIS)

Furmann, B.; Szawiola, G.; Jarosz, A.; Krzykowski, A.; Stefanska, D.; Dembczynski, J.

2010-01-01

Various experimental methods, used in Chair of Quantum Engineering and Metrology for determination of the hyperfine structure of electronic levels in lanthanides atoms and ions, are presented. In turn the spectroscopic methods on an atomic beam (laser induced fluorescence and laser-rf double resonance ABMR-LIRF), laser-rf double resonance in a Paul trap and spectroscopic methods in a hollow cathode discharge (optogalvanic detection and laser induced fluorescence) are presented. Each method has been characterized with its potential accuracy and domain of application. The results achieved for the atoms and the ions of lanthanum, praseodymium, neodymium and europium have been published in numerous articles (compiled in the reference list).

Development of suitable plastic standards for X-ray fluorescence analysis

Energy Technology Data Exchange (ETDEWEB)

Mans, Christian [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: c.mans@fh-muenster.de; Hanning, Stephanie [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: hanning@fh-muenster.de; Simons, Christoph [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: simons@fh-muenster.de; Wegner, Anne [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: awegner@fh-muenster.de; Janssen, Anton [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: janssena@fh-muenster.de; Kreyenschmidt, Martin [University of Applied Sciences Muenster, Department of Chemical Engineering, Advanced Analytical Chemistry, Stegerwaldstr. 39, 48565 Steinfurt (Germany)], E-mail: martin.kreyenschmidt@fh-muenster.de

2007-02-15

For the adoption of the EU directive 'Restriction on use of certain Hazardous Substances' and 'Waste Electrical and Electronic Equipment' using X-ray fluorescence analysis suitable standard materials are required. Plastic standards based on acrylonitrile-butadiene-styrene terpolymer, containing the regulated elements Br, Cd, Cr, Hg and Pb were developed and produced as granulates and solid bodies. The calibration materials were not generated as a dilution from one master batch but rather the element concentrations were distributed over nine independent calibration samples. This was necessary to enable inter-elemental corrections and empirical constant mass absorption coefficients. The produced standard materials are characterized by a homogenous element distribution, which is more than sufficient for X-ray fluorescence analysis. Concentrations for all elements except for Br could be determined by Inductively Coupled Plasma Atomic Emission Spectroscopy after microwave assisted digestion. The concentration of Br was determined by use of Neutron Activation Analysis at Hahn-Meitner-Institute in Berlin, Germany. The correlation of the X-ray fluorescence analysis measurements with the values determined using Inductively Coupled Plasma Atomic Emission Spectroscopy and Neutron Activation Analysis showed a very good linearity.

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

Determination of paraquat in water samples using a sensitive fluorescent probe titration method.

Science.gov (United States)

Yao, Feihu; Liu, Hailong; Wang, Guangquan; Du, Liming; Yin, Xiaofen; Fu, Yunlong

2013-06-01

Paraquat (PQ), a nonselective herbicide, is non-fluorescent in aqueous solutions. Thus, its determination through direct fluorescent methods is not feasible. The supramolecular inclusion interaction of PQ with cucurbit[7]uril was studied by a fluorescent probe titration method. Significant quenching of the fluorescence intensity of the cucurbit[7]uril-coptisine fluorescent probe was observed with the addition of PQ. A new fluorescent probe titration method with high selectivity and sensitivity at the ng/mL level was developed to determine PQ in aqueous solutions with good precision and accuracy based on the significant quenching of the supramolecular complex fluorescence intensity. The proposed method was successfully used in the determination of PQ in lake water, tap water, well water, and ditch water in an agricultural area, with recoveries of 96.73% to 105.77%. The fluorescence quenching values (deltaF) showed a good linear relationship with PQ concentrations from 1.0 x 10(-8) to 1.2 x 10(-5) mol/L with a detection limit of 3.35 x 10(-9) mol/L. In addition, the interaction models of the supramolecular complexes formed between the host and the guest were established using theoretical calculations. The interaction mechanism between the cucurbit[7]uril and PQ was confirmed by 1H NMR spectroscopy.

Limestone rocks analysis by X-ray fluorescence analysis

International Nuclear Information System (INIS)

Izquierdo M, G.; Ponce R, R.; Vazquez J, J.

1996-01-01

By request of a private company, employing basically X-ray fluorescence analysis (X RF), was established a fast and accurate method for the analysis of the major elements in limestone rocks. Additionally, for complementing analysis was determined by ion chromatography, the chlorides appearance and by atomic absorption of sodium. By gravimetry, was determined the losses by ignition and the alpha quartz. (Author)

Synchronous fluorescence based biosensor for albumin determination by cooperative binding of fluorescence probe in a supra-biomolecular host-protein assembly.

Science.gov (United States)

Patra, Digambara

2010-01-15

A synchronous fluorescence probe based biosensor for estimation of albumin with high sensitivity and selectivity was developed. Unlike conventional fluorescence emission or excitation spectral measurements, synchronous fluorescence measurement offered exclusively a new synchronous fluorescence peak in the shorter wavelength range upon binding of chrysene with protein making it an easy identification tool for albumin determination. The cooperative binding of a fluorescence probe, chrysene, in a supramolecular host-protein assembly during various albumin assessments was investigated. The presence of supramolecular host molecules such as beta-cyclodextrin, curucurbit[6]uril or curucurbit[7]uril have little influence on sensitivity or limit of detection during albumin determination but reduced dramatically interference from various coexisting metal ion quenchers/enhancers. Using the present method the limit of detection for BSA and gamma-Globulin was found to be 0.005 microM which is more sensitive than reported values. Copyright 2009 Elsevier B.V. All rights reserved.

Determination of Cu, Cr, and As in preserved wood (Eucalyptus sp.) using x-ray fluorescent spectrometry techniques

International Nuclear Information System (INIS)

Sergio Matias Pereira Junior; Vera Akiko Maihara; Edson Goncalves Moreira; Vera Lucia Ribeiro Salvador; Ivone Mulako Sato

2016-01-01

Energy dispersive (EDXRF) and Portable (PXRF) X-ray fluorescence techniques are proposed for wood treatment control process and wood waste assortment. In this study, different retentions of chromated copper arsenate preservative were applied to Eucalyptus sp. sapwood samples. Cu, Cr and As were determined by XRF techniques in treated sapwood massive blocks and treated sapwood sawdust samples were analyzed by FAAS spectrometry (Flame Atomic Absorption) and INAA (Instrumental Neutron Activation Analysis). Cu, Cr and As mean values, obtained by FAASS and INAA, showed to be statically equal; however, XRF analysis showed considerable deviations, presenting the absorption and the enhancement effects in analytical lines. (author)

Sensitive determination of nucleic acids using organic nanoparticle fluorescence probes

Science.gov (United States)

Zhou, Yunyou; Bian, Guirong; Wang, Leyu; Dong, Ling; Wang, Lun; Kan, Jian

2005-06-01

This paper describes the preparation of organic nanoparticles by reprecipitation method under sonication and vigorous stirring. Transmission electron microscopy (TEM) was used to characterize the size and size distribution of the luminescent nanoparticles. Their average diameter was about 25 nm with a size variation of ±18%. The fluorescence decay lifetime of the nanoparticles also was determined on a self-equipped fluorospectrometer with laser light source. The lifetime (˜0.09 μs) of nanoparticles is about three times long as that of the monomer. The nanoparticles were in abundant of hydrophilic groups, which increased their miscibility in aqueous solution. These organic nanoparticles have high photochemical stability, excellent resistance to chemical degradation and photodegradation, and a good fluorescence quantum yield (25%). The fluorescence can be efficiently quenched by nucleic acids. Based on the fluorescence quenching of nanoparticles, a fluorescence quenching method was developed for determination of microamounts of nucleic acids by using the nanoparticles as a new fluorescent probe. Under optimal conditions, maximum fluorescence quenching is produced, with maximum excitation and emission wavelengths of 345 and 402 nm, respectively. Under optimal conditions, the calibration graphs are linear over the range 0.4-19.0 μg ml -1 for calf thymus DNA (ct-DNA) and 0.3-19.0 μg ml -1 for fish sperm DNA (fs-DNA). The corresponding detection limits are 0.25 μg ml -1 for ct-DNA and 0.17 μg ml -1 for fs-DNA. The relative standard deviation of six replicate measurements is 1.3-2.1%. The method is simple, rapid and sensitive with wide linear range. The recovery and relative standard deviation are very satisfactory.

A sensitive fluorescence quenching method for determination of bismuth with tiron

Energy Technology Data Exchange (ETDEWEB)

Taher, Mohammad Ali; Rahimi, Mina [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Fazelirad, Hamid, E-mail: hamidfazelirad@gmail.com [Department of Chemistry, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Department of Chemistry, Science and Research Branch, Islamic Azad University, Yazd (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, P.O. Box 76175-133, Kerman (Iran, Islamic Republic of)

2014-01-15

We describe a fluorescence quenching method for determination of bismuth with tiron. The method is based on the reaction of tiron by bismuth(III) in acidic media. The influence of variables such as the pH, type of buffer, tiron concentration, reaction time and temperature were investigated. Under optimized conditions, the fluorescence quenching extent is proportional to the concentration of bismuth for Bi–tiron system at the range 0.13–2.09 μg mL{sup −1} and the detection limit is 0.05 μg mL{sup −1}. The proposed sensor presented good repeatability, evaluated in terms of relative standard deviation (R.S.D.=±0.498%) for 11 replicates. This sensitive, rapid and accurate method has been successfully applied to the determination of trace bismuth(III) in water and hair samples and certified reference materials. -- Highlights: • No previous paper report on use of fluorescence quenching for determination of Bi. • Fluorescence quenching of trion is a sensitive method for determination of Bi(III). • Under the optimum conditions the detection limit is very low (0.05 μg mL{sup −1}). • The procedure is simple and safe and has high tolerance limit to interferences.

Determination of atomic cluster structure with cluster fusion algorithm

DEFF Research Database (Denmark)

Obolensky, Oleg I.; Solov'yov, Ilia; Solov'yov, Andrey V.

2005-01-01

We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters.......We report an efficient scheme of global optimization, called cluster fusion algorithm, which has proved its reliability and high efficiency in determination of the structure of various atomic clusters....

Laser induced fluorescence spectroscopy in atomic beams of radioactive nuclides

International Nuclear Information System (INIS)

Rebel, H.; Schatz, G.

1982-01-01

Measurements of the resonant scattering of light from CW tunable dye lasers, by a well collimated atomic beam, enable hyperfine splittings and optical isotope shifts to be determined with high precision and high sensitivity. Recent off-line atomic beam experiments with minute samples, comprising measurements with stable and unstable Ba, Ca and Pb isotopes are reviewed. The experimental methods and the analysis of the data are discussed. Information on the variation of the rms charge radii and on electromagnetic moments of nuclei in long isotopic chains is presented. (orig.) [de

Designing of fluorescent and magnetic imprinted polymer for rapid, selective and sensitive detection of imidacloprid via activators regenerated by the electron transfer-atom transfer radical polymerization (ARGET-ATRP) technique

Science.gov (United States)

Kumar, Sunil; Karfa, Paramita; Madhuri, Rashmi; Sharma, Prashant K.

2018-05-01

In this work, we report on a dual-behavior electrochemical/optical sensor for sensitive determination of Imidacloprid by fluorescent dye (fluorescein, FL) and imprinted polymer modified europium doped superparamagnetic iron oxide nanoparticles (FL@SPIONs@MIP). The imidacloprid (IMD)-imprinted polymer was directly synthesized on the Eu-SPIONs surface via Activators regenerated by the electron transfer-atom transfer radical polymerization (ARGET-ATRP) technique. Preparation, characterization and application of the prepared FL@SPIONs@MIP were systematically investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), fluorescence spectroscopy and electrochemical techniques. The electrochemical experiments exhibited a remarkable selectivity of the prepared sensor towards IMD. Determination of IMD by the square wave stripping voltammetry method represented a wide linear range of 0.059-0.791 μg L-1 with a detection limit of 0.0125 μg L-1. In addition, the fluorescence method shows a linear range of 0.039-0.942 μg L-1 and LOD of 0.0108 μg L-1. The fluorescence property of prepared FL@SPIONs@MIP was used for rapid, on-spot but selective detection of IMD in real samples. The proposed electrode displayed excellent repeatability and long-term stability and was successfully applied for quantitative and trace level determination of IMD in several real samples.

Magnetic Dichroism of Potassium Atoms on the Surface of Helium Nanodroplets

International Nuclear Information System (INIS)

Nagl, Johann; Auboeck, Gerald; Callegari, Carlo; Ernst, Wolfgang E.

2007-01-01

The population ratio of Zeeman sublevels of atoms on the surface of superfluid helium droplets (T=0.37 K) has been measured. Laser induced fluorescence spectra of K atoms are measured in the presence of a moderately strong magnetic field (2.9 kG). The relative difference between the two states of circular polarization of the exciting laser is used to determine the electron spin polarization of the ensemble. Equal fluorescence levels indicate that the two spin sublevels of the ground-state K atom are equipopulated, within 1%. Thermalization to 0.37 K would give a population ratio of 0.35. We deduce that the rate of spin relaxation induced by the droplet must be 2 triplet dimer we find instead full thermalization of the spin

Interplay of vacuum-mediated inter- and intra-atomic couplings in a pair of atoms

International Nuclear Information System (INIS)

Schmid, Sandra Isabelle; Evers, Joerg

2010-01-01

The resonance fluorescence emitted by a system of two dipole-dipole interacting nearby four-level atoms in a J=1/2↔J=1/2 configuration is studied. This setup is the simplest realistic model system which provides a complete description of the (inter-atomic) dipole-dipole interaction for arbitrary orientation of the inter-atomic distance vector, and at the same time allows for intra-atomic spontaneously generated coherences. Our main interest is the interplay of both these different coupling mechanisms. We discuss different methods to analyze the contribution of the various vacuum-induced coupling constants to the total resonance fluorescence spectrum. These allow us to find a dressed state interpretation of the contribution of the different inter-atomic dipole-dipole couplings to the total spectrum. We further study the role of the spontaneously generated coherences, and identify two different contributions to the single-particle vacuum-induced couplings. We show that they have a noticeable impact on the total resonance fluorescence spectrum down to small inter-atomic distances, even though the dipole-dipole coupling constants then are much larger in magnitude than the the single-particle coupling constants. Interestingly, we find that the inter-atomic couplings can induce an effect of the intra-atomic spontaneously generated coherences on the observed spectra which is not present in single-atom systems.

Study on laser atomic spectroscopy

International Nuclear Information System (INIS)

Lee, Jong Min; Song, Kyu Seok; Jeong, Do Young; Kim, Chul Joong; Han, Phil Soon

1992-01-01

Electric discharge type atomic vaporizer is developed for the spectroscopic study on actinide elements. Laser induced fluorescence study on actinide elements is performed by using this high temperature type atomizer. For the effective photoionization of elements, copper vapor laser pumped dye laser and electron beam heating type atomic vaporizer are built and their characteristics are measured. In addition, resonance ionization mass spectroscopic analysis for lead sample as well as laser induced fluorescence study on uranium sample in solution phase is made. (Author)

[The intraoperative determination of intestinal vitality with a fluorescent indicator].

Science.gov (United States)

Ivanov, A; Terziev, I

1997-01-01

Intestinal obstruction due to strangulation is induced in dogs under experimental conditions, with intestinal wall vitality assessment done on the ground of standard clinical criteria, using fluorescence dye and UV rays, as well as histological study. Sensitivity, specificity and prognostic value of each of the methods employed are determined. The fluorescence method advantages are recorded, and the prospects of its clinical implementation are estimated.

Determination of microquantities of cesium in leaching tests by atomic absorption spectrometry with electrothermal atomization

International Nuclear Information System (INIS)

Crubellati, R.O.; Di Santo, N.R.

1988-01-01

An original method for cesium determinations by atomic absorption spectrometry with electrothermal atomization is described. The effect of foreign ions (alkali and earth alkaline metals) present in leaching test of glasses with incorporated radioactive wastes was studied. The effect of different mineral acids was also investigated. A comparison between the flame excitation method and the electrothermal atomization one was made. Under optimum conditions, cesium in quantities down to 700 ng in 1000 ml of sample could be determined. The calibration curve was linear in the range of 0.7 - 15 ng/mL. The fact that the proposed determinations can be performed in a short time and that a small sample volume is required are fundamental advantages of this method, compared with the flame excitation procedure. Besides, it is adaptable to be applied in hot cells and glove boxes. (Author) [es

Major constituent quantitative determination in uranium alloys by coupled plasma atomic emission spectrometry and X ray fluorescence wavelength dispersive spectrometry

International Nuclear Information System (INIS)

Oliveira, Luis Claudio de; Silva, Adriana Mascarenhas Martins da; Gomide, Ricardo Goncalves; Silva, Ieda de Souza

2013-01-01

A wavelength-dispersive X-ray fluorescence (WD-XRF) spectrometric method for determination of major constituents elements (Zr, Nb, Mo) in Uranium/Zirconium/Niobium and Uranium/Molybdenum alloy samples were developed. The methods use samples taken in the form of chips that were dissolved in hot nitric acid and precipitate particles melted with lithium tetraborate and dissolved in hot nitric acid and finally analyzed as a solution. Studies on the determination by inductively coupled plasma optic emission spectrometry (ICP OES) using matched matrix in calibration curve were developed. The same samples solution were analyzed in both methods. The limits of detection (LOD), linearity of the calibrations curves, recovery study, accuracy and precision of the both techniques were carried out. The results were compared. (author)

Direct atomic absorption determination of silicon in metallic niobium

International Nuclear Information System (INIS)

Blinova, Eh.S.; Guzeev, I.D.; Nedler, V.V.; Khokhrin, V.M.

1984-01-01

Consideration is being given to realization of the basic advantage of non-flame atomizer-analysis of directly solid samples-for silicon determination in niobium for the content of the first one of less than 1x10 -3 mass %. Analysis technique is described. Diagrams of the dependences of atomic silicon absorption in graphite cells of usual type as well as lined by tungsten carbide and atomic silicon absorption on the value of niobium weighed amount are presented. It is shown that Si determination in metallic niobium according to aqueous reference solutions results in understatement of results 2.4 times. The optimal conditions for Si determination in niobium are the following: 2400 deg C temperature, absence of carbon and oxygen. Different niobium specimens with the known silicon content were used as reference samples

Laser diagnostics of atomic hydrogen and oxygen production in rf and microwave plasma discharges

International Nuclear Information System (INIS)

Preppernau, B.L.

1993-01-01

The research for this thesis involved the application of two-photon allowed laser-induced fluorescence (TALIF) to the study of atomic hydrogen and oxygen production in industrial scale radio-frequency and microwave plasma discharge apparatus. Absolute atomic hydrogen concentration profiles were measured in a Gaseous Electronics Conference Reference Cell installed at Wright-Patterson AFB, Ohio operating with a simple H 2 discharge. Two-dimensional atomic hydrogen concentration profiles were also measured in an ASTEX HPMM microwave plasma diamond deposition reactor during actual diamond growth. In addition absolute atomic oxygen concentrations were measured in the ASTEX system. Particular attention as paid to refining the concentration calibration technique and in determining a correction to account for the collisional quenching of excited state fluorescence in high pressure gases

Using chlorophyll fluorescence to determine stress in Eucalyptus ...

African Journals Online (AJOL)

Using chlorophyll fluorescence to determine stress in Eucalyptus grandis seedlings: scientific paper. ... Southern Forests: a Journal of Forest Science ... factors affect the functioning of the photosynthetic system, the status of the photosynthetic apparatus is a good indicator of the plant in terms of stress and stress adaptation.

Thermally activated delayed fluorescence of fluorescein derivative for time-resolved and confocal fluorescence imaging.

Science.gov (United States)

Xiong, Xiaoqing; Song, Fengling; Wang, Jingyun; Zhang, Yukang; Xue, Yingying; Sun, Liangliang; Jiang, Na; Gao, Pan; Tian, Lu; Peng, Xiaojun

2014-07-09

Compared with fluorescence imaging utilizing fluorophores whose lifetimes are in the order of nanoseconds, time-resolved fluorescence microscopy has more advantages in monitoring target fluorescence. In this work, compound DCF-MPYM, which is based on a fluorescein derivative, showed long-lived luminescence (22.11 μs in deaerated ethanol) and was used in time-resolved fluorescence imaging in living cells. Both nanosecond time-resolved transient difference absorption spectra and time-correlated single-photon counting (TCSPC) were employed to explain the long lifetime of the compound, which is rare in pure organic fluorophores without rare earth metals and heavy atoms. A mechanism of thermally activated delayed fluorescence (TADF) that considers the long wavelength fluorescence, large Stokes shift, and long-lived triplet state of DCF-MPYM was proposed. The energy gap (ΔEST) of DCF-MPYM between the singlet and triplet state was determined to be 28.36 meV by the decay rate of DF as a function of temperature. The ΔE(ST) was small enough to allow efficient intersystem crossing (ISC) and reverse ISC, leading to efficient TADF at room temperature. The straightforward synthesis of DCF-MPYM and wide availability of its starting materials contribute to the excellent potential of the compound to replace luminescent lanthanide complexes in future time-resolved imaging technologies.

Laser induced fluorescence spectroscopy for FTU

International Nuclear Information System (INIS)

Hughes, T.P.

1995-07-01

Laser induced fluorescence spectroscopy (LIFS) is based on the absorption of a short pulse of tuned laser light by a group of atoms and the observation of the resulting fluorescence radiation from the excited state. Because the excitation is resonant it is very efficient, and the fluorescence can be many times brighter than the normal spontaneous emission, so low number densities of the selected atoms can be detected and measured. Good spatial resolution can be achieved by using a narrow laser beam. If the laser is sufficiently monochromatic, and it can be tuned over the absorption line profile of the selected atoms, information can also be obtained about the velocities of the atoms from the Doppler effect which can broaden and shift the line. In this report two topics are examined in detail. The first is the effect of high laser irradiance, which can cause 'power broadening' of the apparent absorption line profile. The second is the effect of the high magnetic field in FTU. Detailed calculations are given for LIFS of neutral iron and molybdenum atoms, including the Zeeman effect, and the implementation of LIFS for these atoms on FTU is discussed

A new vapor generation system for mercury species based on the UV irradiation of mercaptoethanol used in the determination of total and methyl mercury in environmental and biological samples by atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yin, Yanmin; Qiu, Jianhua; Yang, Limin [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Wang, Qiuquan [College of Chemistry and Chemical Engineering, Xiamen University, Department of Chemistry and the MOE Key Laboratory of Analytical Sciences, Xiamen (China); Xiamen University, State Key Laboratory of Marine Environmental Science, Xiamen (China)

2007-06-15

A new vapor generation system for mercury (Hg) species based on the irradiation of mercaptoethanol (ME) with UV was developed to provide an effective sample introduction unit for atomic fluorescence spectrometry (AFS). Preliminary investigations of the mechanism of this novel vapor generation system were based on GC-MS and FT-IR studies. Under optimum conditions, the limits of determination for inorganic divalence mercury and methyl mercury were 60 and 50 pg mL{sup -1}, respectively. Certified reference materials (BCR 463 tuna fish and BCR 580 estuarine sediment) were used to validate this new method, and the results agreed well with certified values. This new system provides an attractive alternative method of chemical vapor generation (CVG) of mercury species compared to other developed CVG systems (for example, the traditional KBH{sub 4}/NaOH-acid system). To our knowledge, this is the first systematic report on UV/ME-based Hg species vapor generation and the determination of total and methyl Hg in environmental and biological samples using UV/ME-AFS. (orig.)

Selective determination of four arsenic species in rice and water samples by modified graphite electrode-based electrolytic hydride generation coupled with atomic fluorescence spectrometry.

Science.gov (United States)

Yang, Xin-An; Lu, Xiao-Ping; Liu, Lin; Chi, Miao-Bin; Hu, Hui-Hui; Zhang, Wang-Bing

2016-10-01

This work describes a novel non-chromatographic approach for the accurate and selective determining As species by modified graphite electrode-based electrolytic hydride generation (EHG) for sample introduction coupled with atomic fluorescence spectrometry (AFS) detection. Two kinds of sulfydryl-containing modifiers, l-cysteine (Cys) and glutathione (GSH), are used to modify cathode. The EHG performance of As has been changed greatly at the modified cathode, which has never been reported. Arsenite [As(III)] on the GSH modified graphite electrode (GSH/GE)-based EHG can be selectively and quantitatively converted to AsH3 at applied current of 0.4A. As(III) and arsenate [As(V)] on the Cys modified graphite electrode (Cys/GE) EHG can be selectively and efficiently converted to arsine at applied current of 0.6A, whereas monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) do not form any or only less volatile hydrides under this condition. By changing the analytical conditions, we also have achieved the analysis of total As (tAs) and DMA. Under the optimal condition, the detection limits (3s) of As(III), iAs and tAs in aqueous solutions are 0.25μgL(-1), 0.22μgL(-1) and 0.10μgL(-1), respectively. The accuracy of the method is verified through the analysis of standard reference materials (SRM 1568a). Copyright © 2016 Elsevier B.V. All rights reserved.

A comparative evaluation of different ionic liquids for arsenic species separation and determination in wine varietals by liquid chromatography - hydride generation atomic fluorescence spectrometry.

Science.gov (United States)

Castro Grijalba, Alexander; Fiorentini, Emiliano F; Martinez, Luis D; Wuilloud, Rodolfo G

2016-09-02

The application of different ionic liquids (ILs) as modifiers for chromatographic separation and determination of arsenite [As(III)], arsenate [As(V)], dimethylarsonic acid (DMA) and monomethylarsonic acid (MMA) species in wine samples, by reversed-phase high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry detection (RP-HPLC-HG-AFS) was studied in this work. Several factors influencing the chromatographic separation of the As species, such as pH of the mobile phase, buffer solution concentration, buffer type, IL concentration and length of alkyl groups in ILs were evaluated. The complete separation of As species was achieved using a C18 column in isocratic mode with a mobile phase composed of 0.5% (v/v) 1-octyl-3-methylimidazolium chloride ([C8mim]Cl) and 5% (v/v) methanol at pH 8.5. A multivariate methodology was used to optimize the variables involved in AFS detection of As species after they were separated by HPLC. The ILs showed remarkable performance for the separation of As species, which was obtained within 18min with a resolution higher than 0.83. The limits of detection for As(III), As(V), MMA and DMA were 0.81, 0.89, 0.62 and 1.00μg As L(-1). The proposed method was applied for As speciation analysis in white and red wine samples originated from different grape varieties. Copyright © 2016 Elsevier B.V. All rights reserved.

Uranium determination using atomic spectrometric techniques: An overview

International Nuclear Information System (INIS)

Santos, Juracir S.; Teixeira, Leonardo S.G.; Santos, Walter N.L. dos; Lemos, Valfredo A.; Godoy, Jose M.; Ferreira, Sergio L.C.

2010-01-01

This review focuses on the determination of uranium using spectroanalytical techniques that are aimed at total determination such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma optical emission spectrometry (ICP-OES); and inductively coupled plasma mass spectrometry (ICP-MS) that also enables the determination of uranium isotopes. The advantages and shortcomings related to interferences, precision, accuracy, sample type and equipment employed in the analysis are taken into account, as well as the complexity and costs (i.e., acquisition, operation and maintenance) associated with each of the techniques. Strategies to improve their performance that employ separation and/or preconcentration steps are considered, with an emphasis given to solid-phase extraction because of its advantages compared to other preconcentration procedures.

To test photon statistics by atomic beam deflection

International Nuclear Information System (INIS)

Wang Yuzhu; Chen Yudan; Huang Weigang; Liu Liang

1985-02-01

There exists a simple relation between the photon statistics in resonance fluorescence and the statistics of the momentum transferred to an atom by a plane travelling wave [Cook, R.J., Opt. Commun., 35, 347(1980)]. Using an atomic beam deflection by light pressure, we have observed sub-Poissonian statistics in resonance fluorescence of two-level atoms. (author)

Determination of lead and cadmium in urine by electrothermal atomization atomic absorption spectrometry

International Nuclear Information System (INIS)

Vasil'eva, L.A.; Grinshtejn, I.L.; Gucher, Sh.; Izgi, B.

2008-01-01

The applicability of a DETATA sorbent to the preconcentration of lead and cadmium followed by the determination of these elements in urine using atomic absorption spectrometry with electrothermal atomization was demonstrated. After preconcentration by a factor of 10, the limits of detection were 0.01 and 0.2 μg/l for cadmium and lead, respectively. The accuracy of the results was supported by the analysis of Seronorm TM Trace Elements Urine Batch no.101021 [ru

Spatially and Temporally Resolved Atomic Oxygen Measurements in Short Pulse Discharges by Two Photon Laser Induced Fluorescence

Science.gov (United States)

Lempert, Walter; Uddi, Mruthunjaya; Mintusov, Eugene; Jiang, Naibo; Adamovich, Igor

2007-10-01

Two Photon Laser Induced Fluorescence (TALIF) is used to measure time-dependent absolute oxygen atom concentrations in O2/He, O2/N2, and CH4/air plasmas produced with a 20 nanosecond duration, 20 kV pulsed discharge at 10 Hz repetition rate. Xenon calibrated spectra show that a single discharge pulse creates initial oxygen dissociation fraction of ˜0.0005 for air like mixtures at 40-60 torr total pressure. Peak O atom concentration is a factor of approximately two lower in fuel lean (φ=0.5) methane/air mixtures. In helium buffer, the initially formed atomic oxygen decays monotonically, with decay time consistent with formation of ozone. In all nitrogen containing mixtures, atomic oxygen concentrations are found to initially increase, for time scales on the order of 10-100 microseconds, due presumably to additional O2 dissociation caused by collisions with electronically excited nitrogen. Further evidence of the role of metastable N2 is demonstrated from time-dependent N2 2^nd Positive and NO Gamma band emission spectroscopy. Comparisons with modeling predictions show qualitative, but not quantitative, agreement with the experimental data.

Evaluation of an inductively-coupled plasma with an extended-sleeve torch as an atomization cell for laser-excited fluorescence spectrometry.

Science.gov (United States)

Kosinski, M A; Uchida, H; Winefordner, J D

1983-05-01

An inductively-coupled plasma (ICP) with an extended-sleeve torch has been evaluated as an atomization cell for laser-excited fluorescence spectrometry. Limits of detection for 20 lines are given. The detection power is almost equivalent to that obtained by excitation with a hollow-cathode lamp. Interelement effects and spectral interferences are discussed.

Data analysis of x-ray fluorescence holography by subtracting normal component from inverse hologram

International Nuclear Information System (INIS)

Happo, Naohisa; Hayashi, Kouichi; Hosokawa, Shinya

2010-01-01

X-ray fluorescence holography (XFH) is a powerful technique for determining three-dimensional local atomic arrangements around a specific fluorescing element. However, the raw experimental hologram is predominantly a mixed hologram, i.e., a mixture of hologram generated in both normal and inverse modes, which produces unreliable atomic images. In this paper, we propose a practical subtraction method of the normal component from the inverse XFH data by a Fourier transform for the calculated hologram of a model ZnTe cluster. Many spots originating from the normal components could be properly removed using a mask function, and clear atomic images were reconstructed at adequate positions of the model cluster. This method was successfully applied to the analysis of experimental ZnTe single crystal XFH data. (author)

X-ray fluorescence holography.

Science.gov (United States)

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu, Wen; Matsushita, Tomohiro

2012-03-07

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy.

X-ray fluorescence holography

International Nuclear Information System (INIS)

Hayashi, Kouichi; Happo, Naohisa; Hosokawa, Shinya; Hu Wen; Matsushita, Tomohiro

2012-01-01

X-ray fluorescence holography (XFH) is a method of atomic resolution holography which utilizes fluorescing atoms as a wave source or a monitor of the interference field within a crystal sample. It provides three-dimensional atomic images around a specified element and has a range of up to a few nm in real space. Because of this feature, XFH is expected to be used for medium-range local structural analysis, which cannot be performed by x-ray diffraction or x-ray absorption fine structure analysis. In this article, we explain the theory of XFH including solutions to the twin-image problem, an advanced measuring system, and data processing for the reconstruction of atomic images. Then, we briefly introduce our recent applications of this technique to the analysis of local lattice distortions in mixed crystals and nanometer-size clusters appearing in the low-temperature phase of a shape-memory alloy. (topical review)

Determination of adenosine disodium triphosphate using prulifloxacin-terbium(III) as a fluorescence probe by spectrofluorimetry

International Nuclear Information System (INIS)

Yu Fengshan; Li Lin; Chen Fang

2008-01-01

A new spectrofluorimetric method is developed for determination of adenosine disodium triphosphate (ATP). The interactions between prulifloxacin (PUFX)-Tb 3+ complex and adenosine disodium triphosphate has been studied by using UV-vis absorption and fluorescence spectra. Using prulifloxacin-Tb 3+ as a fluorescence probe, under the optimum conditions, ATP can remarkably enhance the fluorescence intensity of the prulifloxacin-Tb 3+ complex at λ = 545 nm and the enhanced fluorescence intensity is in proportion to the concentration of ATP. Optimum conditions for the determination of ATP were also investigated. The dynamic range for the determination of ATP is 4.0 x 10 -7 to 2.0 x 10 -5 mol L -1 , and the detection limit (3 σ/k) is 1.7 x 10 -8 mol L -1 . This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of ATP in real pharmaceutical samples. The mechanism of fluorescence enhancement of prulifloxacin-Tb 3+ complex by ATP was also discussed

Highly sensitive and interference-free determination of bismuth in environmental samples by electrothermal vaporization atomic fluorescence spectrometry after hydride trapping on iridium-coated tungsten coil

International Nuclear Information System (INIS)

Liu Rui; Wu Peng; Xu Kailai; Lv Yi; Hou Xiandeng

2008-01-01

Bismuthine was on-line trapped on tungsten coil and subsequently electrothermally vaporized for the determination by atomic fluorescence spectrometry (AFS). Several noble metals, including Pd, Rh, Pt, and Ir, were explored as permanent chemical modifier for tungsten coil on-line trapping. Investigation showed that Ir gave the best performance, in which bismuthine was on-line trapped on Ir-coated tungsten coil at 560 o C, and then released at 1550 o C for subsequent transfer to AFS by a mixture of Ar and H 2 . Under optimum instrumental conditions, the trapping efficiency was found to be 73 ± 3%. With 120 s (12 mL sample volume) trapping time, a limit of detection (LOD) of 4 ng L -1 was obtained, compared to conventional hydride generation AFS (0.09 μg L -1 ); the LOD can be lowered down to 1 ng L -1 by increasing the trapping time to 480 s. The LOD was found to be better or at least comparable to literature levels involving on-line trapping and some other sophisticated instrumental methods such as ICP-MS and GF-AAS. A comprehensive interference study involving conventional hydride-forming elements and some transition metals was carried out, and the result showed that the gas phase interference from other hydride-forming elements was largely reduced, thanks to the use of on-line tungsten coil trapping. Finally, the proposed method was applied to the determination of bismuth in several biological and environmental standard reference materials, and a t-test shows that the analytical results by the proposed method have no significant difference from the certified values at the confidence level of 95%

Fission products determination in high activity waste solution by wavelength dispersive X-ray fluorescence spectral interference correction by intensity ratio

International Nuclear Information System (INIS)

Sato, I.M.

1988-01-01

Fission products Se, Rb, Y, Zr, Mo, Ru, Rh, Pd, Te, Cd, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu and Gd were determined in simulated high activity radioactive waste solution by wavelength dispersive X-ray fluorescence spectrometry without chemical separation. Thin layer technique was employed for the sample preparation. For the L spectral lines, the absorption effect was verified by Rasberry-Heinrich, Lucas Tooth-Pyne and Lachance-Trail relations. This effect was quantified and corrected accordingly. The spectral interferences of Kα and/or Lα lines of Y, Zr, Mo, La, Ce, Pr, Nd, Sm, Eu and Gd elements were eliminated by the intensity ratio method. The overlapping of up to three analytical lines was corrected by applying this method. The concentration influence of the interfering element on the intensity ratio values as well the efficiency of the correction method were investigated in order to assure that no systematic or residual error, resulting from the correction, affect the actual fluorescent intensity determination. The results is compared with the data obtained from measurements of free lines of spectral interference and also with those obtained by the linear equation system. Fission products determination presented a precision in the range of 0.1 to 5.0% and an accuracy of up to ± 7.0% the results are compared with those obtained by neutron activation analysis and inductively coupled plasma - atomic emission spectrometry. Leaching data, when radioactive waste is incorporated in cement matrix, were attempted by X-ray fluorescence technique. For two years leaching period, leaching rate and diffusion coefficient data of cesium were determined. The results obtained agree with those obtained by γ-spectromety. (author) [pt

ZnSe quantum dots based fluorescence quenching method for determination of paeoniflorin

International Nuclear Information System (INIS)

Chen, Zhi; Chen, Jiayi; Liang, Qiaowen; Wu, Dudu; Zeng, Yuaner; Jiang, Bin

2014-01-01

Water soluble ZnSe quantum dots (QDs) modified by mercaptoacetic acid (MAA) were used to determinate paeoniflorin in aqueous solutions by the fluorescence spectroscopic technique. The results showed that the fluorescence of the modified ZnSe QDs could be quenched by paeoniflorin effectively in physiological buffer solution. The optimum fluorescence intensity was found to be at incubation time 10 min, pH 7.0 and temperature 25 °C. Under the optimal conditions, the detection limit of paeoniflorin was 7.30×10 −7 mol L −1 . Moreover, the quenching mechanism was discussed to be a static quenching procedure, which was proved by quenching rate constant K q (1.02×10 13 L mol −1 s −1 ). -- Highlights: • The fluorescence intensity of ZnSe QDs could be quenched by paeoniflorin. • Foreign substance showed insignificant effect for determination of paeoniflorin. • The quenching mechanism was discussed to be a static quenching procedure

ZnSe quantum dots based fluorescence quenching method for determination of paeoniflorin

Energy Technology Data Exchange (ETDEWEB)

Chen, Zhi [Center of Analysis, Guangdong Medical College, Dongguan 523808 (China); School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Chen, Jiayi; Liang, Qiaowen [School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Wu, Dudu [Center of Analysis, Guangdong Medical College, Dongguan 523808 (China); Zeng, Yuaner, E-mail: zengyuaner@126.com [School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Jiang, Bin, E-mail: gzjiangbin@hotmail.com [School of Chinese Herbal Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China)

2014-01-15

Water soluble ZnSe quantum dots (QDs) modified by mercaptoacetic acid (MAA) were used to determinate paeoniflorin in aqueous solutions by the fluorescence spectroscopic technique. The results showed that the fluorescence of the modified ZnSe QDs could be quenched by paeoniflorin effectively in physiological buffer solution. The optimum fluorescence intensity was found to be at incubation time 10 min, pH 7.0 and temperature 25 °C. Under the optimal conditions, the detection limit of paeoniflorin was 7.30×10{sup −7} mol L{sup −1}. Moreover, the quenching mechanism was discussed to be a static quenching procedure, which was proved by quenching rate constant K{sub q} (1.02×10{sup 13} L mol{sup −1} s{sup −1}). -- Highlights: • The fluorescence intensity of ZnSe QDs could be quenched by paeoniflorin. • Foreign substance showed insignificant effect for determination of paeoniflorin. • The quenching mechanism was discussed to be a static quenching procedure.

Disparity in formulations used for fluorescent X-ray intensity measurements

International Nuclear Information System (INIS)

Mittal, Raj; Gupta, Sheenu

2011-01-01

The paper presents a problem in computations of X-ray fluorescence cross-sections, shell/sub-shell fluorescence yields, Coster-Kronig yields, vacancy alignment, etc. from X-ray fluorescence (XRF) studies. While using barn/atom as a unit for cross-sections if the atomic masses are not considered it causes a discrepancy in the measured cross-section, yield and alignment values. Most of the earlier publications are being quoted where such an oversight has occurred and discrepancy is evident. - Highlights: → Manuscript gives basic formulation for measurements of fluorescent X-ray intensities. → Most publications ignored the fact that use of barn/atom units for cross-sections requires atomic masses. → Published experimental results higher by a factor ≥2 or less by factor 1/M K . → Inspection of published data on XRF parameters needed.

Impurity studies in fusion devices using laser-fluorescence-spectroscopy

International Nuclear Information System (INIS)

Husinsky, W.R.

1980-08-01

Resonance fluorescence excitation of neutral atoms using tunable radiation from dye lasers offers a number of unique advantages for impurity studies in fusion devices. Using this technique, it is possible to perform local, time-resolved measurements of the densities and velocity distributions of metallic impurities in fusion devices without disturbing the plasma. Velocities are measured by monitoring the fluorescence intensity while tuning narrow bandwidth laser radiation through the Doppler - broadened absorbtion spectrum of the transition. The knowledge of the velocity distribution of neutral impurities is particularly useful for the determination of impurity introduction mechanisms. The laser fluorescence technique will be described in terms of its application to metallic impurities in fusion devices and related laboratory experiments. Particular attention will be given to recent results from the ISX-B tokamak using pulsed dye lasers where detection sensitivities for neutral Fe of 10 6 atoms/cm 3 with a velocity resolution of 600 m/sec (0.1 eV) have been achieved. Techniques for exciting plasma particles (H,D) will also be discussed

The Effects of Heteroatoms Si and S on Tuning the Optical Properties of Rhodamine- and Fluorescein-Based Fluorescence Probes: A Theoretical Analysis.

Science.gov (United States)

Zhou, Panwang; Ning, Cai; Alsaedi, Ahmed; Han, Keli

2016-10-05

The effects of the incorporated heteroatoms Si and S on tuning the optical properties of rhodamine- and fluorescein-based fluorescence probes is investigated using DFT and time-dependent DFT with four different functionals. As previously proposed, the large redshift (90 nm) produced by a Si atom in both the absorption and emission spectra can be attributed to the σ*-π* conjugation between the σ* orbital of the Si atom and the π* orbital of the adjacent carbon atoms. However, the presence of a Si atom does not alter the fluorescence quenching mechanism of the nonfluorescent forms of the investigated compounds. For the first time, these theoretical results indicate that the n orbital of the S atom plays an important role in determining the optical properties of the nonfluorescent form of rhodamine-based fluorescence probes. It alters the fluorescence quenching mechanism by lowering the energy of the dark nπ* state, which is due to breakage of the C10-S52 bond upon photoexcitation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Atomic Physics of Fe K alpha: Toward Accurate Abundance Diagnostics for Supernova Remnants

Science.gov (United States)

Brickhouse, Nancy

2009-09-01

We propose to conduct a case study of Fe XVI K alpha emission produced during the transient ionization of a supernova remnant. This study includes critical evaluation of the existing data for electron impact inner-shell ionization and fluorescence yields, including tests conducted using a variety of theoretical atomic physics methods. Standard and newly developed atomic codes will be used. Once error estimates for the atomic data are complete, we will propagate these errors using the APEC code to simulate spectra and determine the overall accuracy of iron abundances determined from X-ray spectra.

Collisional and radiative processes in fluorescent lamps

International Nuclear Information System (INIS)

Lister, Graeme G.

2003-01-01

Since electrode life is the major limiting factor in operating fluorescent lamps, many lighting companies have introduced 'electrodeless' fluorescent lamps, using inductively coupled discharges. These lamps often operate at much higher power loadings than standard lamps and numerical models have not been successful in reproducing experimental measurements in the parameter ranges of interest. A comprehensive research program was undertaken to study the fundamental physical processes of these discharges, co-funded by the Electric Power Research Institute (EPRI) and OSRAM SYLVANIA under the name of ALITE. The program included experiments and modeling of radiation transport, computations of electron-atom and atom-atom cross sections and the first comprehensive power balance studies of a highly loaded fluorescent lamp. Results from the program and their importance to the understanding of the physics of fluorescent lamps are discussed, with particular emphasis on the important collisional and radiative processes. Comparisons between results of experimental measurements and numerical models are presented

Determination of Atomic Data Pertinent to the Fusion Energy Program

International Nuclear Information System (INIS)

Reader, J.

2013-01-01

We summarize progress that has been made on the determination of atomic data pertinent to the fusion energy program. Work is reported on the identification of spectral lines of impurity ions, spectroscopic data assessment and compilations, expansion and upgrade of the NIST atomic databases, collision and spectroscopy experiments with highly charged ions on EBIT, and atomic structure calculations and modeling of plasma spectra

Non-chromatographic speciation analysis of mercury by flow injection on-line preconcentration in combination with chemical vapor generation atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Wu Hong; Jin Yan; Han Weiying; Miao, Qiang; Bi Shuping

2006-01-01

A novel non-chromatographic approach for direct speciation of mercury, based on the selective retention inorganic mercury and methylmercury on the inner wall of a knotted reactor by using ammonium diethyl dithiophosphate and dithizone as complexing agents respectively, was developed for flow injection on-line sorption preconcentration coupled with chemical vapor generation non-dispersive atomic fluorescence spectrometry. With the sample pH kept at 2.0, the preconcentration of inorganic mercury on the inner walls of the knotted reactor was carried out based on the exclusive retention of Hg-DDP complex in the presence of methylmercury via on-line merging the sample solution with ammonium diethyl dithiophosphate solution, and selective preconcentration methylmercury was achieved with dithizone instead of ammonium diethyl dithiophosphate. A 15% (v/v) HCl was introduced to elute the retained mercury species and merge with KBH 4 solution for atomic fluorescence spectrometry detection. Under the optimal experimental conditions, the sample throughputs of inorganic mercury and methylmercury were 30 and 20 h -1 with the enhancement factors of 13 and 24. The detection limits were found to be 3.6 ng l -1 for Hg 2+ and 2.0 ng l -1 for CH 3 Hg + . The precisions (RSD) for the 11 replicate measurements of each 0.2 μg l -1 of Hg 2+ and CH 3 Hg + were 2.2% and 2.8%, respectively. The developed method was validated by the analysis of certified reference materials (simulated natural water, rice flour and pork) and by recovery measurements on spiked samples, and was applied to the determination of inorganic mercury and methylmercury in biological and environmental water samples

Automated dispersive liquid-liquid microextraction coupled to high performance liquid chromatography - cold vapour atomic fluorescence spectroscopy for the determination of mercury species in natural water samples.

Science.gov (United States)

Liu, Yao-Min; Zhang, Feng-Ping; Jiao, Bao-Yu; Rao, Jin-Yu; Leng, Geng

2017-04-14

An automated, home-constructed, and low cost dispersive liquid-liquid microextraction (DLLME) device that directly coupled to a high performance liquid chromatography (HPLC) - cold vapour atomic fluorescence spectroscopy (CVAFS) system was designed and developed for the determination of trace concentrations of methylmercury (MeHg + ), ethylmercury (EtHg + ) and inorganic mercury (Hg 2+ ) in natural waters. With a simple, miniaturized and efficient automated DLLME system, nanogram amounts of these mercury species were extracted from natural water samples and injected into a hyphenated HPLC-CVAFS for quantification. The complete analytical procedure, including chelation, extraction, phase separation, collection and injection of the extracts, as well as HPLC-CVAFS quantification, was automated. Key parameters, such as the type and volume of the chelation, extraction and dispersive solvent, aspiration speed, sample pH, salt effect and matrix effect, were thoroughly investigated. Under the optimum conditions, linear range was 10-1200ngL -1 for EtHg + and 5-450ngL -1 for MeHg + and Hg 2+ . Limits of detection were 3.0ngL -1 for EtHg + and 1.5ngL -1 for MeHg + and Hg 2+ . Reproducibility and recoveries were assessed by spiking three natural water samples with different Hg concentrations, giving recoveries from 88.4-96.1%, and relative standard deviations <5.1%. Copyright © 2017 Elsevier B.V. All rights reserved.

Significant improvement of accuracy and precision in the determination of trace rare earths by fluorescence analysis

International Nuclear Information System (INIS)

Ozawa, L.; Hersh, H.N.

1976-01-01

Most of the rare earths in yttrium, gadolinium and lanthanum oxides emit characteristic fluorescent line spectra under irradiation with photons, electrons and x rays. The sensitivity and selectivity of the rare earth fluorescences are high enough to determine the trace amounts (0.01 to 100 ppM) of rare earths. The absolute fluorescent intensities of solids, however, are markedly affected by the synthesis procedure, level of contamination and crystal perfection, resulting in poor accuracy and low precision for the method (larger than 50 percent error). Special care in preparation of the samples is required to obtain good accuracy and precision. It is found that the accuracy and precision for the determination of trace (less than 10 ppM) rare earths by fluorescence analysis improved significantly, while still maintaining the sensitivity, when the determination is made by comparing the ratio of the fluorescent intensities of the trace rare earths to that of a deliberately added rare earth as reference. The variation in the absolute fluorescent intensity remains, but is compensated for by measuring the fluorescent line intensity ratio. Consequently, the determination of trace rare earths (with less than 3 percent error) is easily made by a photoluminescence technique in which the rare earths are excited directly by photons. Accuracy is still maintained when the absolute fluorescent intensity is reduced by 50 percent through contamination by Ni, Fe, Mn or Pb (about 100 ppM). Determination accuracy is also improved for fluorescence analysis by electron excitation and x-ray excitation. For some rare earths, however, accuracy by these techniques is reduced because indirect excitation mechanisms are involved. The excitation mechanisms and the interferences between rare earths are also reported

Rotationally cooled laser induced fluorescence determination of polycyclic aromatic hydrocarbons

International Nuclear Information System (INIS)

Warren, J.A.; Hayes, J.M.; Small, G.J.

1982-01-01

In recent years the development of new highly selective and sensitive methods for the characterization and determination of polycyclic aromatic hydrocarbons (PAHs) and their derivatives in complex mixtures has received considerable attention. High selectivity is associated here with the ability to distinguish between substitutional isomers of PAHs. Attainment of this selectivity with capillary column-gas chromatography-mass spectrometry for complex mixtures is very difficult and time-consuming. Alternative approaches are, therefore, required. Given that the majority of PAHs fluoresce with reasonable quantum yields and that high sensitivities are afforded by fluorescence detection, the possibility of developing high-resolution fluorescence based techniques is attractive. This is all the more so if the technique's selectivity does not rely on physical separation, e.g., chromatography. In this paper discussion is limited to such techniques

Peptide-stabilized, fluorescent silver nanoclusters

DEFF Research Database (Denmark)

Gregersen, Simon; Vosch, Tom André Jos; Jensen, Knud Jørgen

2016-01-01

Few-atom silver nanoclusters (AgNCs) can exhibit strong fluorescence; however, they require ligands to prevent aggregation into larger nanoparticles. Fluorescent AgNCs in biopolymer scaffolds have so far mainly been synthesized in solution, and peptides have only found limited use compared to DNA...

Advanced in X-ray fluorescence holography

CERN Document Server

Hayashi, K

2002-01-01

X-ray fluorescence holography (XFH) can resolve 'phase problem' in crystal diffraction and therefore it provides 3D atomic images around specific elements. Since first demonstration of the XFH in 1996, view of atoms has been improved rapidly with the refinement of the hologram data collection method. The present performance of the XFH makes it possible to apply to impurity, thin film and quasicrystal, and opens a way to practical tool for determination of local structure. In this paper, theory including solutions for twin image problem, advanced experimental systems and application to Si sub 0 sub . sub 9 sub 9 sub 9 Ge sub 0 sub . sub 0 sub 0 sub 1 are discussed. (author)

Electronic excitation of Ti atoms sputtered by energetic Ar+ and He+ from clean and monolayer oxygen covered surfaces

International Nuclear Information System (INIS)

Pellin, M.J.; Gruen, D.M.; Young, C.E.; Wiggins, M.D.; Argonne National Lab., IL

1983-01-01

Electronic excitation of Ti atoms ejected during energetic ion bombardment (Ar + , He + ) of well characterized clean and oxygen covered polycrystalline Ti metal surfaces has been determined. For states with 0 to 2 eV and 3 to 5.5 eV of electronic energy, static mode laser fluorescence spectroscopy (LFS) and static mode spontaneous fluorescence spectroscopy (SFS) were used respectively. These experiments which were carried out in a UHV ( -10 Torr) system equipped with an Auger spectrometer provide measurements of the correlation between oxygen coverage (0 to 3 monolayers) and the excited state distribution of sputtered Ti atoms. The experimentally determined electronic partition function of Ti atoms does not show an exponential dependence on energy (E) above the ground state but rather an E -2 or E -3 power law dependence. (orig.)

Optimization of a spectrometry for energy-dispersive x-ray fluorescence analysis by x-ray tube in combination with secondary target for multielements determination of sediment samples

International Nuclear Information System (INIS)

Zaidi Embong; Husin Wagiran

1997-01-01

The design of an energy-dispersive X-ray fluorescence spectrometer equipped with a conventional X-ray tube and secondary target is described. The spectrometer system constructed in our laboratory consists of a semiconductor detector system, irradiation chamber and X-ray tube. Primary source from X-ray tube was used to produced secondary X-ray from selenium, molybdenum and cadmium targets. The fluorescence X-ray from the sample was detected using Si(Li) detector with resolution of 0. 175 keV (Mn-K(x). The spectrometer was used for determination of multi-elements with atomic number between 20 to 44 in river sediment samples. The X-ray spectrum, from the samples were analysed using computer software which was developed based on Marquardt method. Optimal conditions and detection limits are determined experimentally by variation of excitation parameters for each combination of secondary target and tube voltage

Proton and electron impact on molecular and atomic oxygen: I. High resolution fluorescence spectra in the visible and VUV spectral range and emission cross-sections for dissociative ionisation and excitation of O2

International Nuclear Information System (INIS)

Wilhelmi, O.; Schartner, K.H.

2000-01-01

For pt.II see ibid., vol.11, p.45-58, 2000. Molecular oxygen O 2 was dissociated in collisions with protons and electrons in the intermediate velocity range (p + -energies: 17-800 keV, e - -energies: 0.2-2 keV). Fluorescence from excited atomic and singly ionised fragments and from singly ionised molecules was detected in the VUV and in the visible and near UV spectral range. Highly resolved spectra are presented for the VUV (46-131 nm) and the near UV/visible (340-605 nm) spectral range. Absolute emission cross-sections have been determined for dissociative ionisation and excitation leading to fluorescence in the VUV. Results are compared with published data. (orig.)

X-ray fluorescence analysis for trace element determination in foodstuff chemistry

International Nuclear Information System (INIS)

Wildanger, W.

The physical fundamentals of X-ray fluorescence analysis are given and the routine spectrometers described. The basic principles are given of analytical methods used in qualitative and quantitative fluorescence analyses. Examples are given of the use of the method in a number of fields and the possibility and usefulness is discussed for the determination of trace elements in foodstuffs. The preparation of samples, preliminary concentration of components and calibration methods are discussed. (M.K.)

Quantum dots (QDs) based fluorescence probe for the sensitive determination of kaempferol

Science.gov (United States)

Tan, Xuanping; Liu, Shaopu; Shen, Yizhong; He, Youqiu; Yang, Jidong

2014-12-01

In this work, using the quenching of fluorescence of thioglycollic acid (TGA)-capped CdTe quantum dots (QDs), a novel method for the determination of kaempferol (KAE) has been developed. Under optimum conditions, a linear calibration plot of the quenched fluorescence intensity at 552 nm against the concentration of KAE was observed in the range of 4-44 μg mL-1 with a detection limit (3σ/K) of 0.79 μg mL-1. In addition, the detailed reaction mechanism has also been proposed on the basis of electron transfer supported by ultraviolet-visible (UV-vis) absorption and fluorescence (FL) spectroscopy. The method has been applied for the determination of KAE in pharmaceutical preparations with satisfactory results. The proposed method manifested several advantages such as high sensitivity, short analysis time, low cost and ease of operation.

Determination of antioxidant content in biodiesel by fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Magalhaes, Keurison F.; Caires, Anderson R.L. [Universidade Federal da Grande Dourados, MS (Brazil). Grupo de Optica Aplicada; Oliveira, Samuel L. [Universidade Federal de Mato Grosso do Sul (UFMS), MS (Brazil). Grupo de Optica e Fotonica

2011-07-01

Full text. Biodiesel is an alternative fuel composed by mono-alkyl esters obtained from vegetable oils or animal fats. Due to its chemical structure, biodiesel is highly susceptible to oxidation which leads to formation of insoluble gums and sediments that can block the filter system of fuel injection. Biodiesel made from vegetable oils typically has a small amount of natural antioxidants so that it is necessary to add synthetic antioxidants to enhance its stability and retain their properties for a longer period. The main antioxidants are synthetic phenolic compounds such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert-butyl hydroquinone (TBHQ) as well as natural antioxidants as tocopherols. The fluorescence spectroscopy has been applied for determination of phenolic compounds in oils. Here, a method based on fluorescence is proposed to quantify the BHA and TBHQ antioxidant concentration in biodiesel produced from sunflower and soybean oils. Soybean and sunflower biodiesel were obtained by transesterification of fatty alcohol in the presence of NaOH as catalyst. The reactions were carried out in the molar ratio of 6:1 methanol/oil. After the production and purification, biodiesel samples were stored. Biodiesel samples with BHA and TBHQ concentrations from 1000 to 8000 ppm (m/m) were pre- pared. These samples were diluted in ethanol (95%) in order to measure the fluorescence spectra. Fluorescence and excitation spectra of the solutions were recorded at room temperature using a spectrofluorimeter. The emission spectra were obtained under excitation at about 310nm and fluorescence in the 320-800nm range was evaluated. Biodiesel samples without BHA and TBHQ showed fluorescence band at about 420nm, which can be attributed to tocopherols inherent to the vegetable oils used in the biodiesel production. The addition of BHA and/or TBHQ is responsible for the appearance of a fluorescence band around 330nm. It was verified that the fluorescence

Copper spherical cavity arrays: Fluorescence enhancement in PFO films

Energy Technology Data Exchange (ETDEWEB)

Spada, Edna R., E-mail: edspada@gmail.com [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil); Valente, Gustavo T.; Pereira-da-Silva, Marcelo A. [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil); Sartorelli, Maria L. [Departamento de Física, Universidade Federal de Santa Catarina, Caixa Postal 476, 88040-900, Florianópolis, SC (Brazil); Guimarães, Francisco E.G.; Faria, Roberto M. [Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP (Brazil)

2017-01-15

This manuscript addresses the use of a well-ordered antidot copper nanostructure as a active substrate for surface enhancement fluorescence (SEF). The antidot array was produced by electrodeposition and nanosphere lithography and characterized by microscopy technique, its successful application as SEF-active substrates was verified using polyfluorene (PFO) as a probe layer. Atomic force microscopy (AFM) was used to evaluate the regularity of the metal surface as well PFO coated process and confocal laser fluorescence microscopy (CLSM) to determine the behavior exhibited by the fluorescent layer due to the existence of the nanostructured surface. No accumulation PFO in the cavities was detected and the more intense emission regions coincides with the position of the cavities and is at about one order of magnitude higher.

[Determination of H2S in Rat Intestinal Perfusion Solution Based on Fluorescence Analysis].

Science.gov (United States)

Hou, Jun-feng; Li, Xin-xia; Shen, Xue-ru; Huojia, Miliban; Guan, Ming

2015-08-01

Under alkaline conditions, Fluorescein mercury has strong fluorescence, however, when it met S(2-), its fluorescence would quench, in view of the above, a fluorescence method for determination of H2S in biological samples was established. In the 0.1 mol · L(-1) NaOH dilution, when the concentration of fluorescein Mercury and Na2S was 5.0 × 10(-5) and 1.0 × 10(-5) mol · L(-1) respectively, the fluorescence intensity of system was determined at 522 nm. The results showed that, at the range of 4.0 × 10(-7)~2.0 × 10(-6) mol · L(-1), the concentration decreasing of H2S and fluorescence intensity had good linear relationship, r=0.9980, the RSD of precision test was 4.59% (n=7), the detection limit was 3.5 × 10(-8) mol · L(-1), the content of H2S in the sample were 1.01 × 10(-6) and 1.15 × 10(-6) mol · L(-1), and the recovery rate was 95.8%~101.0%, the method has the advantages of simple operation, high sensitivity, good selectivity, can accurately determine of H2S in intestinal perfused solution, and provides the basis for the determination of endogenous H2S.

Determination of K shell absorption jump factors and jump ratios in the elements between Tm(Z = 69) and Os(Z = 76) by measuring K shell fluorescence parameters

International Nuclear Information System (INIS)

Kaya, N.; Tirasoglu, E.; Apaydin, G.

2008-01-01

The K shell absorption jump factors and jump ratios have been measured in the elements between Tm (Z = 69) and Os(Z = 76) without having any mass attenuation coefficient at the upper and lower energy branch of the K absorption edge. The jump factors and jump ratios for these elements have been determined by measuring K shell fluorescence parameters such as the total atomic absorption cross-sections, the K α X-ray production cross-sections, the intensity ratio of the K β and K α X-rays and the K shell fluorescence yields. We have performed the measurements for the calculations of these values in attenuation and direct excitation experimental geometry. The K X-ray photons are excited in the target using 123.6 keV gamma-rays from a strong 57 Co source, and detected with an Ultra-LEGe solid state detector with a resolution 0.15 keV at 5.9 keV. The measured values have been compared with theoretical and others' experimental values. The results have been plotted versus atomic number

Determination of K shell absorption jump factors and jump ratios in the elements between Tm( Z = 69) and Os( Z = 76) by measuring K shell fluorescence parameters

Science.gov (United States)

Kaya, N.; Tıraşoğlu, E.; Apaydın, G.

2008-04-01

The K shell absorption jump factors and jump ratios have been measured in the elements between Tm ( Z = 69) and Os( Z = 76) without having any mass attenuation coefficient at the upper and lower energy branch of the K absorption edge. The jump factors and jump ratios for these elements have been determined by measuring K shell fluorescence parameters such as the total atomic absorption cross-sections, the K α X-ray production cross-sections, the intensity ratio of the K β and K α X-rays and the K shell fluorescence yields. We have performed the measurements for the calculations of these values in attenuation and direct excitation experimental geometry. The K X-ray photons are excited in the target using 123.6 keV gamma-rays from a strong 57Co source, and detected with an Ultra-LEGe solid state detector with a resolution 0.15 keV at 5.9 keV. The measured values have been compared with theoretical and others' experimental values. The results have been plotted versus atomic number.

[Fluorescence Determination of Trace Se with the Hydride-K13-Rhodamine 6G System].

Science.gov (United States)

Liang, Ai-hui; Li, Yuan; Huang, Shan-shan; Luo, Yang-he; Wen, Gui-qing; Jiang, Zhi-liang

2015-05-01

Se is a necessary trace element for human and animals, but the excess intake of Se caused poison. Thus, it is very important to determination of Se in foods and water. The target of this study is development of a new, sensitive and selective hydride generation-molecular fluorescence method for the determination of Se. In 0. 36 mol . L-1 sulfuric acid, NaBH4 as reducing agent, Se (IV) is reduced to H2 Se. Usin3-g I solution as absorption liquid3, I- is reduced to I- by H2Se. When adding rhodamine 6G, Rhodamine 6G and I3- form association particles, which lead to the fluorescence intensity decreased. When Se(IV) existing, Rhodamine 6G and I3- bind less, And the remaining amount of Rhodamine 6G increase. So the fluorescence intensity is enhanced. The analytical conditions were optimized, a 0. 36 ml . L-1 H2SO4, 21. 6.g . L-1 NaBH4, 23.3 µm . L-1 rhodamine 6G, and 50 µmol . L-1 KI3 were chosen for use. When the excitation wavelength is at 480nm, the Rayleigh scattering peak does not affect the fluorescence recording, and was selected for determination of Se. Under the selected conditions, Se(IV) concentration in the 0. 02~0. 60 µg . mL-1 range and the increase value of the fluorescence intensity (ΔF) at 562 nm linear relationship. The linear regression equation is ΔF562 nm =12. 6c + 20. 9. The detecton limit was 0.01 µ.g . L-1. The influence of coexistence substances on the hydride generatin-molecular fluorescence determination of 5. 07 X10(-6) mol . L-1 Se(IV) was considered in details. Results showed that this new fluorescence method is of high selectivity, that is, 0. 5 mmol. L-1 Ba2+, Ca2+, Zn2+ and Fe3+, 0. 25 mmol . L-1 . Mg2+, 0. 05 mmol . L-1 K+, 0. 2 mmol . L-1 Al3+, 0. 025 mmol . L-1 Te(VI) do not interfere with the determination. The influence of Hg2+, CD2+ and Cu2+ that precipitate with Se(IV), can be eliminated by addition of complex reagent. This hydride generation-molecular fluorescence method has been applied to determination of trace Se in water

X-ray fluorescence spectroscopic determination of heavy metals and ...

African Journals Online (AJOL)

Purpose: To determine the heavy metal and trace element composition of the powdered aerial parts of Origanum sipyleum L. and its water extract. Methods: The heavy metal and trace elements content of the powdered plant material and 2 % aqueous extract were evaluated by x-ray fluorescence spectroscopy with silicon ...

Analysis of heavy metals and minerals elements in the turmeric using Total-Reflection X-ray Fluorescence analysis technique and Atomic Absorption Spectrometry

International Nuclear Information System (INIS)

Andriamisetra, V.M.Z.

2014-01-01

Currently, many studies demonstrate anti-cancer and anti-inflammatory benefits of turmeric. The aims of this work is to perform analysis of metals such as calcium, chromium, manganese, iron, cobalt, nickel, copper, zinc, arsenic, bromine, rubidium, strontium, cadmium and lead in the turmeric collected from various places in Madagascar. The analysis by total reflection X-ray fluorescence technique is used to determine the concentrations of heavy metals, while the atomic absorption spectrometry is used for the determination of trace elements. Analysis results show that the concentration of calcium in the turmeric is very high, its average concentration is 1025.8 mg.kg -1 . The average concentrations of manganese, of copper and of iron are respectively 44.7 mg.kg -1 ; 19.7 mg.kg -1 and 53.6 mg.kg -1 . The average concentrations of zinc, of rubidium and of strontium are respectively 17.3 mg.kg -1 ; 35.2 mg.kg -1 and 21.7 mg.kg -1 [fr

Determination of some elements along the length of pine needles by means of the scanning energy dispersive x-ray fluorescence (EDXRF) method

International Nuclear Information System (INIS)

Viksna, A.; Katkevics, J.; Nulle, S.

1998-01-01

The scanning energy dispersive X-ray fluorescence (EDXDF) is used to measure the distribution of trace elements along the length of single pine needles. The current set up allows simultaneous determination up to 15 trace elements. The pilot experiments showed that the distribution of some elements varied along length of the pine needle. Concentration variations of trace elements with the needle age and needle position within the foliage crown were also observed. This could be one way of studying the annual physiological cycle of needles. The scanning EDXRF method was compared with graphite furnace atomic absorption spectrometry (GFAAS). (authors)

Nuclear and atomic spectroscopy group. Dosimetry in medical physics

International Nuclear Information System (INIS)

Rubio, M.

1990-01-01

The main activities of radiation physics on the sector of atomic spectroscopy and x-ray fluorescence analysis in the Faculty of Mathematics, Astronomy and Physics (University of Cordoba, Argentina),are presented, including dosimetric studies in radiodiagnostic: dosimetric determination using Monte Carlo method; distortion effect study on PET image and lasers in medicine. (C.G.C.)

Determination of the radial distribution function with the tomographic atom probe

International Nuclear Information System (INIS)

Heinrich, A.; Al-Kassab, T.

2004-01-01

Full text: An algorithm for the determination of the radial distribution function (RDF) and the partial radial distribution function from tomographic atom probe data is introduced and some examples for its application are discussed. Homogeneous distribution of atoms can easily be determined from measured data. Using our algorithm, the lattice of simple cubic structures may be estimated solely from TAP data. The results for bcc and fcc alloys and metals will be presented. By evaluating the vicinity of each atom, information about order phenomena in multi component alloy can be retrieved including short range order. The advantage of determining the (partial) radial distribution functions for any sample with our algorithm is that all data can be derived by one single experiment whereas all other methods of determining a pRDF require one experiment for each pRDF. (author)

Photodesorption of Na atoms from rough Na surfaces

DEFF Research Database (Denmark)

Balzer, Frank; Gerlach, R.; Manson, J.R.

1997-01-01

We investigate the desorption of Na atoms from large Na clusters deposited on dielectric surfaces. High-resolution translational energy distributions of the desorbing atoms are determined by three independent methods, two-photon laser-induced fluorescence, as well as single-photon and resonance......-enhanced two-photon ionization techniques. Upon variation of surface temperature and for different substrates (mica vs lithium fluoride) clear non-Maxwellian time-of-flight distributions are observed with a cos θ angular dependence and most probable kinetic energies below that expected of atoms desorbing from...... atoms are scattered by surface vibrations. Recent experiments providing time constants for the decay of the optical excitations in the clusters support this model. The excellent agreement between experiment and theory indicates the importance of both absorption of the laser photons via direct excitation...

Sensitivity of in vivo X-ray fluorescence determination of skeletal lead stores

International Nuclear Information System (INIS)

Sokas, R.K.; Besarab, A.; McDiarmid, M.A.; Shapiro, I.M.; Bloch, P.

1990-01-01

Eighteen patients with known past occupational lead exposure underwent parenteral diagnostic chelation with ethylenediaminetetraacetic acid and x-ray fluorescent determination of in vivo skeletal lead stores at the distal styloid process of the ulna and at the temporal base bone using a cobalt 57 source and measuring lead Ka x-rays. X-ray fluorescent lead measurements in both locations correlated with results of diagnostic chelation. Using a post-chelation urinary excretion of greater than 600 micrograms lead/24 h as the definition of high-lead stores, sensitivity of x-ray fluorescence at the wrist and temple was 56% and 39%, respectively

Non-chromatographic speciation analysis of mercury by flow injection on-line preconcentration in combination with chemical vapor generation atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Wu Hong [School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093 (China); Department of Chemistry, Xuzhou Normal University, Xuzhou 221116 (China); Jin Yan [School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093 (China); Han Weiying [School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093 (China); Miao, Qiang [School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093 (China); Bi Shuping [School of Chemistry and Chemical Engineering, State Key Laboratory of Coordination Chemistry and Key Laboratory of MOE for Life Science, Nanjing University, Nanjing 210093 (China)]. E-mail: bisp@nju.edu.cn

2006-07-15

A novel non-chromatographic approach for direct speciation of mercury, based on the selective retention inorganic mercury and methylmercury on the inner wall of a knotted reactor by using ammonium diethyl dithiophosphate and dithizone as complexing agents respectively, was developed for flow injection on-line sorption preconcentration coupled with chemical vapor generation non-dispersive atomic fluorescence spectrometry. With the sample pH kept at 2.0, the preconcentration of inorganic mercury on the inner walls of the knotted reactor was carried out based on the exclusive retention of Hg-DDP complex in the presence of methylmercury via on-line merging the sample solution with ammonium diethyl dithiophosphate solution, and selective preconcentration methylmercury was achieved with dithizone instead of ammonium diethyl dithiophosphate. A 15% (v/v) HCl was introduced to elute the retained mercury species and merge with KBH{sub 4} solution for atomic fluorescence spectrometry detection. Under the optimal experimental conditions, the sample throughputs of inorganic mercury and methylmercury were 30 and 20 h{sup -1} with the enhancement factors of 13 and 24. The detection limits were found to be 3.6 ng l{sup -1} for Hg{sup 2+} and 2.0 ng l{sup -1} for CH{sub 3}Hg{sup +}. The precisions (RSD) for the 11 replicate measurements of each 0.2 {mu}g l{sup -1} of Hg{sup 2+} and CH{sub 3}Hg{sup +} were 2.2% and 2.8%, respectively. The developed method was validated by the analysis of certified reference materials (simulated natural water, rice flour and pork) and by recovery measurements on spiked samples, and was applied to the determination of inorganic mercury and methylmercury in biological and environmental water samples.

[Simultaneous determination of multiple elements in airborne particulate samples by X-ray fluorescence spectrometry].

Science.gov (United States)

Takada, T; Hitosugi, M; Kadowaki, T; Kudo, M

1983-07-01

An energy dispersive X-ray fluorescence spectrometer (EDX) has been applied to determine multielements in the workplace air. The standards for X-ray fluorescence analysis were prepared by the chelate precipitation method on polyvinyl chloride (PVC) membrane filter. And, the specimens were prepared to deposit various metal compounds of different chemical forms by the suspension method on PVC membrane filter, and they were determined with EDX and atomic absorption spectrometer (AAS). The results obtained were as follows. Though there is a difference by each element, an amount less than 3 microgram/cm2 per unit area makes it possible to undergo multielement analysis, that is, is has no influence on fine particle effect (particle size; under 5 microns). Then, effects of the X-ray intensity by different chemical forms are negligible. At the presence the neighboring element and other elements this technique showed greater precision by carrying out on corrective treatment, etc. The coefficient of variation of this technique was in the range of 2.5-6.5% at DDTC-Cu of 0.5-5.0 micrograms/cm2, with the limit of detection for As : 0.002 microgram/cm2, Zn : 0.003 microgram/cm2, Pb : 0.003 microgram/cm2, Cu : 0.004 microgram/cm2, Ni : 0.003 microgram/cm2, Fe : 0.005 microgram/cm2, Mn : 0.008 microgram/cm2, Cr : 0.013 microgram/cm2, respectively. Aerosols collected at the workplace were analyzed with EDX and AAS, and the obtained results showed good agreement with such regression line as y = 1.04 chi + 0.04, the coefficient of correlation being r = 0.995. From these results, this technique was found to be a very excellent method for monitoring of multielements in the workplace air.

Determination of molybdenum in human urine by electrothermal atomization atomic absorption spectrometry

International Nuclear Information System (INIS)

Pita Calvo, C.; Bermejo Barrera, P.; Bermejo Barrera, A.

1995-01-01

Various matrix modifiers were investigated for the determination of molybdenum in human urine samples by electrothermal atomization atomic absorption spectrometry. Methods with nitric acid, barium difluoride, magnesium nitrate, palladium-magnesium nitrate and palladium-hydroxylamine hydrochloride were studied by introducing the urine samples directly into the graphite furnace with 0.3% Triton X-100. The charring and atomization curves, the amount of modifier and the calibration and addition graphs were studied in all instances. The precision, accuracy and chemical interferences of the methods were also investigated. The matrix interferences have been removed with the modifiers barium difluoride, palladium-magnesium nitrate and palladium-hydroxylamine hydrochloride. The limits of detection and quantification were 0.2 and 0.7 μg l -1 , respectively, for these modifiers. The characteristic masses were 14.1, 18.0 and 14.9 pg of Mo for palladium-magnesium nitrate, palladium-hydroxylamine hydrochloride and barium difluoride, respectively. The method with palladium-magnesium nitrate has been applied to the study of the amount of molybdenum in human urine samples. The molybdenum levels found lie between 4.8-205.6 μg l -1

Cloud point extraction for trace inorganic arsenic speciation analysis in water samples by hydride generation atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Li, Shan, E-mail: ls_tuzi@163.com; Wang, Mei, E-mail: wmei02@163.com; Zhong, Yizhou, E-mail: yizhz@21cn.com; Zhang, Zehua, E-mail: kazuki.0101@aliyun.com; Yang, Bingyi, E-mail: e_yby@163.com

2015-09-01

A new cloud point extraction technique was established and used for the determination of trace inorganic arsenic species in water samples combined with hydride generation atomic fluorescence spectrometry (HGAFS). As(III) and As(V) were complexed with ammonium pyrrolidinedithiocarbamate and molybdate, respectively. The complexes were quantitatively extracted with the non-ionic surfactant (Triton X-114) by centrifugation. After addition of antifoam, the surfactant-rich phase containing As(III) was diluted with 5% HCl for HGAFS determination. For As(V) determination, 50% HCl was added to the surfactant-rich phase, and the mixture was placed in an ultrasonic bath at 70 °C for 30 min. As(V) was reduced to As(III) with thiourea–ascorbic acid solution, followed by HGAFS. Under the optimum conditions, limits of detection of 0.009 and 0.012 μg/L were obtained for As(III) and As(V), respectively. Concentration factors of 9.3 and 7.9, respectively, were obtained for a 50 mL sample. The precisions were 2.1% for As(III) and 2.3% for As(V). The proposed method was successfully used for the determination of trace As(III) and As(V) in water samples, with satisfactory recoveries. - Highlights: • Cloud point extraction was firstly established to determine trace inorganic arsenic(As) species combining with HGAFS. • Separate As(III) and As(V) determinations improve the accuracy. • Ultrasonic release of complexed As(V) enables complete As(V) reduction to As(III). • Direct HGAFS analysis can be performed.

Antimony speciation analysis in sediment reference materials using high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry

International Nuclear Information System (INIS)

Potin-Gautier, M.; Pannier, F.; Quiroz, W.; Pinochet, H.; Gregori, I. de

2005-01-01

This work presents the development of suitable methodologies for determination of the speciation of antimony in sediment reference samples. Liquid chromatography with a post-column photo-oxidation step and hydride generation atomic fluorescence spectrometry as detection system is applied to the separation and determination of Sb(III), Sb(V) and trimethylantimony species. Post-column decomposition and hydride generation steps were studied for sensitive detection with the AFS detector. This method was applied to investigate the conditions under which speciation analysis of antimony in sediment samples can be carried out. Stability studies of Sb species during the extraction processes of solid matrices, using different reagents solutions, were performed. Results demonstrate that for the extraction yield and the stability of Sb species in different marine sediment extracts, citric acid in ascorbic acid medium was the best extracting solution for antimony speciation analysis in this matrix (between 55% and 65% of total Sb was recovered from CRMs, Sb(III) being the predominant species). The developed method allows the separation of the three compounds within 6 min with detection limits of 30 ng g -1 for Sb(III) and TMSbCl2 and 40 ng g -1 for Sb(V) in sediment samples

Water analysis. Determination of elements by atomic absorption

International Nuclear Information System (INIS)

Anon.

Analysis of homogeneous water solutions (plain water, polluted waters, effluents...) by atomic absorption spectrometry with correction for non specific absorption. The quantity ratio is determined by comparison with standard solutions, correction tables are given [fr

Laser fluorescence determination of radioactive waste cotton fabric in the exploration of uranium content

International Nuclear Information System (INIS)

Wang Jiangong

2010-01-01

In order to meet the dosage test the operational needs of the laser fluorescence determination of trace radioactive waste cotton fabric uranium research and exploration, to determine the sample ashing time, measured dosage of acidity and digestion and other technical parameters, gives the laser fluorescence determination of radioactive abandoned cotton fabric of trace uranium method. Method of high sensitivity, strong anti-interference, the detection limit of 0.025μg/g(Burning down dregs), relative standard deviation was 3.96%, the mean recovery 93.3%-103% for masks, gloves and other radioactive waste to the determination of trace uranium. (authors)

Determination of sparfloxacin with CdSe/CdS quantum dots as fluorescent probes

Energy Technology Data Exchange (ETDEWEB)

Hou, Ming, E-mail: gxglzws@foxmail.com; Yan, Xiaoya; Xiong, Ling

2015-01-15

Water-soluble CdSe/CdS quantum dots (QDs) modified with thioglycolic acid (TGA) were synthesized. A novel method for determination of sparfloxacin (SPFX) has been developed based on quenching of the fluorescence of QDs at 556 nm wavelength. The optimum fluorescence intensity was found in 0.067 mol L{sup −1} KH{sub 2}PO{sub 4}–Na{sub 2}HPO{sub 4} buffer solution at pH 6.47 of 3.0×10{sup −5} mol L{sup −1} QDs. When the concentration of quantum dots is 3.0×10{sup −5} mol L{sup −1} the fluorescence quenching intensity of QDs is linearly proportional to the concentration of SPFX from 0.5 μg mL{sup −1} to 30 μg mL{sup −1}, with correlation coefficient R=0.9983. The detection limit for SPFX was 0.1391 μg mL{sup −1}. The method was used for determination of SPFX in tablets, and the results agreed with the claimed value. Trace amounts of SPFX in milk were also determined with the recovery of 95.3–106.8%. - Highlights: • Water-soluble CdSe/CdS quantum dots modified with thioglycolic acid were synthesized. • Determination of sparfloxacin was based on quenching of the fluorescence of QDs. • The detection limit for sparfloxacin was 0.1391 μg mL{sup −1}. • The method has been used successfully to determine SPFX in tablets and milk.

X-ray fluorescence determination of cobalt in iron-manganese oceanic concretions

International Nuclear Information System (INIS)

Ivanenko, V.V.; Kustov, V.N.; Metelev, A.Yu.; Rakita, K.A.

1989-01-01

A method was developed for resolution of weak analytical lines for elements determined by radionuclide-excited X-ray fluorescence multi-element analysis. The method was used aboart for determining cobalt and some other commercially valuable elements in iron-manganese concretions of Pacific ocean 109 Cd was used as an ionizing radiation source

Fluorescent turn-on determination of the activity of peptidases using peptide templated gold nanoclusters

International Nuclear Information System (INIS)

Luo, Junjun; Wang, Liqiang; Zeng, Ke; Shen, Congcong; Qian, Pin; Yang, Minghui; Rasooly, Avraham; Qu, Fengli

2016-01-01

The fluorescence intensity of gold nanoclusters (AuNCs) is inversely related to the length of a peptide immobilized on its surface. This finding has been exploited to design a turn-on fluorescent method for the determination of the activity of peptidase. The β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) was chosen as a model peptidase. BACE1 cleaves the peptide substrates on AuNCs, and the fluorescence intensity of the AuNCs (at exCitation/emission wavelengths of 320/405 nm) carrying the rest of the cleaved peptide is significantly higher than that of the AuNCs with uncleaved peptide. Transmission electron microscopy revealed a decrease in the size of the AuNCs which is assumed cause fluorescence enhancement. The assay was applied to the determination of BACE1 activity in spiked cell lysates, and recoveries were between 96.9 and 104.0 %. (author)

Determination of sulfur and chlorine in fodder by X-ray fluorescence spectral analysis and comparison with other analytical methods

Science.gov (United States)

Nečemer, Marijan; Kump, Peter; Rajčevič, Marija; Jačimović, Radojko; Budič, Bojan; Ponikvar, Maja

2003-07-01

Sulfur and chlorine are essential elements in the metabolic processes of ruminants, and correct planning strategy of ruminant nutrition should provide a sufficient content of S and Cl in the animal's body. S and Cl can be found in various types of animal fodder in the form of organic compounds and minerals. In this work, the Cl and S content in forage was determined by X-ray fluorescence spectrometry (XRF), and its performance was then compared in parallel analyses by instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and potentiometric methods. The results were compared and critically evaluated in order to assess the performance and capability of the XRF technique in analysis of animal fodder.

Determination of sulfur and chlorine in fodder by X-ray fluorescence spectral analysis and comparison with other analytical methods

Energy Technology Data Exchange (ETDEWEB)

Necemer, Marijan; Kump, Peter; Rajcevic, Marija; Jacimovic, Radojko; Budic, Bojan; Ponikvar, Maja

2003-07-18

Sulfur and chlorine are essential elements in the metabolic processes of ruminants, and correct planning strategy of ruminant nutrition should provide a sufficient content of S and Cl in the animal's body. S and Cl can be found in various types of animal fodder in the form of organic compounds and minerals. In this work, the Cl and S content in forage was determined by X-ray fluorescence spectrometry (XRF), and its performance was then compared in parallel analyses by instrumental neutron activation analysis (INAA), inductively coupled plasma atomic emission spectrometry (ICP-AES) and potentiometric methods. The results were compared and critically evaluated in order to assess the performance and capability of the XRF technique in analysis of animal fodder.

Sub-Doppler temperature measurements of laser-cooled atoms using optical nanofibres

International Nuclear Information System (INIS)

Russell, Laura; Daly, Mark J; Chormaic, Síle Nic; Deasy, Kieran; Morrissey, Michael J

2012-01-01

We present a method for measuring the average temperature of a cloud of cold 85 Rb atoms in a magneto-optical trap using an optical nanofibre. A periodic spatial variation is applied to the magnetic fields generated by the trapping coils and this causes the trap centre to oscillate, which, in turn, causes the cloud of cold atoms to oscillate. The optical nanofibre is used to collect the fluorescence emitted by the cold atoms, and the frequency response between the motion of the centre of the oscillating trap and the cloud of atoms is determined. This allows us to make measurements of cloud temperature both above and below the Doppler limit, thereby paving the way for nanofibres to be integrated with ultracold atoms for hybrid quantum devices

Determination of ammonium on an integrated microchip with LED-induced fluorescence detection.

Science.gov (United States)

Xue, Shuhua; Uchiyama, Katsumi; Li, Hai-Fang

2012-01-01

A simply fabricated microfluidic device integrated with a fluorescence detection system has been developed for on-line determination of ammonium in aqueous samples. A 365-nm light-emitting diode (LED) as an excitation source and a minor band pass filter were mounted into a polydimethylsiloxane (PDMS)-based microchip for the purpose of miniaturization of the entire analytical system. The ammonium sample reacted with o-phthaldialdehyde (OPA) on-chip with sodium sulfite as reducing reagent to produce a fluorescent isoindole derivative, which can emit fluorescence signal at about 425 nm when excited at 365 nm. Effects of pH, flow rate of solutions, concentrations of OPA-reagent, phosphate and sulfite salt were investigated. The calibration curve of ammonium in the range of 0.018-1.8 microg/mL showed a good linear relationship with R2 = 0.9985, and the detection limit was (S/N = 3) 3.6 x 10(-4) microg/mL. The relative standard deviation was 2.8% (n = 11) by calculating at 0.18 microg/mL ammonium for repeated detection. The system was applied to determine the ammonium concentration in rain and river waters, even extent to other analytes fluorescence detection by the presented device.

Laser-Induced Photofragmentation Fluorescence Imaging of Alkali Compounds in Flames.

Science.gov (United States)

Leffler, Tomas; Brackmann, Christian; Aldén, Marcus; Li, Zhongshan

2017-06-01

Laser-induced photofragmentation fluorescence has been investigated for the imaging of alkali compounds in premixed laminar methane-air flames. An ArF excimer laser, providing pulses of wavelength 193 nm, was used to photodissociate KCl, KOH, and NaCl molecules in the post-flame region and fluorescence from the excited atomic alkali fragment was detected. Fluorescence emission spectra showed distinct lines of the alkali atoms allowing for efficient background filtering. Temperature data from Rayleigh scattering measurements together with simulations of potassium chemistry presented in literature allowed for conclusions on the relative contributions of potassium species KOH and KCl to the detected signal. Experimental approaches for separate measurements of these components are discussed. Signal power dependence and calculated fractions of dissociated molecules indicate the saturation of the photolysis process, independent on absorption cross-section, under the experimental conditions. Quantitative KCl concentrations up to 30 parts per million (ppm) were evaluated from the fluorescence data and showed good agreement with results from ultraviolet absorption measurements. Detection limits for KCl photofragmentation fluorescence imaging of 0.5 and 1.0 ppm were determined for averaged and single-shot data, respectively. Moreover, simultaneous imaging of KCl and NaCl was demonstrated using a stereoscope with filters. The results indicate that the photofragmentation method can be employed for detailed studies of alkali chemistry in laboratory flames for validation of chemical kinetic mechanisms crucial for efficient biomass fuel utilization.

Spectrofluorimetric determination of trace amount of coenzyme II using ciprofloxacin-terbium complex as a fluorescent probe

International Nuclear Information System (INIS)

Bian Weiwei; Wang Yusheng; Zhu Xiaojing; Jiang Chongqiu

2006-01-01

A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using terbium ion (Tb 3+ )-ciprofloxacin (CIP) complex as a fluorescent probe, in the buffer solution of pH=9.00, NADP can remarkably enhance the fluorescence intensity of the Tb 3+ -CIP complex at λ=545nm and the enhanced fluorescence intensity of Tb 3+ ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.9x10 -7 -3.7x10 -6 molL -1 with detection limit of 1.3x10 -7 molL -1 . This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Tb 3+ -CIP system and the Tb 3+ -CIP-NADP system have been also discussed

Mercury speciation by high-performance liquid chromatography atomic fluorescence spectrometry using an integrated microwave/UV interface. Optimization of a single step procedure for the simultaneous photo-oxidation of mercury species and photo-generation of Hg0

International Nuclear Information System (INIS)

Quadros, Daiane P.C. de; Campanella, Beatrice; Onor, Massimo; Bramanti, Emilia; Borges, Daniel L.G.; D'Ulivo, Alessandro

2014-01-01

We described the hyphenation of photo-induced chemical vapor generation with high performance liquid chromatography–atomic fluorescence spectrometry (HPLC–AFS) for the quantification of inorganic mercury, methylmercury (MeHg) and ethylmercury (EtHg). In the developed procedure, formic acid in mobile phase was used for the photodecomposition of organomercury compounds and reduction of Hg 2+ to mercury vapor under microwave/ultraviolet (MW/UV) irradiation. We optimized the proposed method studying the influence of several operating parameters, including the type of organic acid and its concentration, MW power, composition of HPLC mobile phase and catalytic action of TiO 2 nanoparticles. Under the optimized conditions, the limits of detection were 0.15, 0.15 and 0.35 μg L −1 for inorganic mercury, MeHg and EtHg, respectively. The developed method was validated by determination of the main analytical figures of merit and applied to the analysis of three certified reference materials. The online interfacing of liquid chromatography with photochemical-vapor generation–atomic fluorescence for mercury determination is simple, environmentally friendly, and represents an attractive alternative to the conventional tetrahydroborate (THB) system. - Highlights: • Inorganic and organic mercury were determined by photochemical vapor generation using a MW/UV photochemical reactor. • The optimized procedure has been applied to the speciation of Hg(II), MeHg and EtHg coupling HPLC with PVG–AFS. • The proposed method is simple, sensitive, and is established for mercury determination in biological materials

Determination of hafnium, molybdenum, and vanadium in niobium and niobium-based alloys by atomic absorption spectrometry

International Nuclear Information System (INIS)

Ide, Kunikazu; Kobayashi, Takeshi; Sudo, Emiko.

1985-01-01

The analytical procedure is as follows: Weigh 1 g of a sample and put it into a 100 cm 3 PTFE beaker. Add 5 ml of distilled water and 5 ml of hydrofluoric acid, and then heat the solution on a hot plate, adding 3 ml of nitric acid dropwise. Dilute the solution to 100 cm 3 with distilled water. When hafnium is determined, add 2 g of diammonium titanium hexafluoride ((NH 4 ) 2 TiF 6 )) before dilution. Working standard solutions are prepared by adding the stock standard solutions of hafnium, molybdenum, and vanadium into niobium solutions. When hafnium is determined, add 2 g of (NH 4 ) 2 TiF 6 and the alloying elements in amounts corresponding to those in sample solutions into the working standard solutions. The tolerable amounts of hydrofluoric acid were 2.9 M, 2.1 M, and 3.1 M and those of nitric acid were 1.0 M, 1.6 M, and 1.6 M for hafnium, molybdenum, and vanadium, respectively. It was found that (NH 4 ) 2 TiF 6 greatly increased the sensitivity for hafnium determination. Niobium showed minus effect for hafnium and plus effect for molybdenum and vanadium. The atomic absorption of molybdenum and vanadium were not influenced by the presence of 20 % of each alloying element, while the atomic absorption of hafnium was given plus effect by 20 % of zirconium, iron, cobalt, nickel, manganese, chromium or vanadium and minus effect by 20 % tungsten. The analytical values of hafnium, molybdenum, and vanadium in niobium-based alloys by this method showed a good agreement with those by X-ray fluorescence analysis. The lower limits of determination (S/N=2) were 0.05, 0.001, and 0.002 % and the relative standard deviation were 3, 1, and 1.5 % for hafnium, molybdenum, and vanadium, respectively. (author)

A comparative study on total reflection X-ray fluorescence determination of low atomic number elements in air, helium and vacuum atmospheres using different excitation sources

Science.gov (United States)

Misra, N. L.; Kanrar, Buddhadev; Aggarwal, S. K.; Wobrauschek, Peter; Rauwolf, M.; Streli, Christina

2014-09-01

A comparison of trace element determinations of low atomic number (Z) elements Na, Mg, Al, P, K and Ca in air, helium and vacuum atmospheres using W Lβ1, Mo Kα and Cr Kα excitations has been made. For Mo Kα and W Lβ1 excitations a Si (Li) detector with beryllium window was used and measurements were performed in air and helium atmospheres. For Cr Kα excitation, a Si (Li) detector with an ultra thin polymer window (UTW) was used and measurements were made in vacuum and air atmospheres. The sensitivities of the elemental X-ray lines were determined using TXRF spectra of standard solutions and processing them by IAEA QXAS program. The elemental concentrations of the elements in other solutions were determined using their TXRF spectra and pre-determined sensitivity values. The study suggests that, using the above experimental set up, Mo Kα excitation is not suited for trace determination of low atomic number element. Excitation by WLβ1 and helium atmosphere, the spectrometer can be used for the determination of elements with Z = 15 (P) and above with fairly good detection limits whereas Cr Kα excitation with ultra thin polymer window and vacuum atmosphere is good for the elements having Z = 11 (Na) and above. The detection limits using this set up vary from 7048 pg for Na to 83 pg for Ti.

Determination of hafnium by atomic absorption spectrometry

International Nuclear Information System (INIS)

Yoshida, Isao; Kobayashi, Hiroshi; Ueno, Keihei.

1977-01-01

Optimum conditions for atomic absorption spectrophotometric determination of hafnium were investigated by use of a Jarrel-Ash AA-1 instrument which was equipped with a premixed gas burner slotted 50 mm in length and 0.4 mm in width. Absorption of hafnium, which was atomized in an nitrous oxide-acetylene flame, was measured on a resonance line at 307.29 nm. The absorption due to hafnium was enhanced in the presence of ammonium fluoride and iron(III) ion, as shown in Figs. 2 and 3, depending on their concentration. The highest absorption was attained by the addition of (0.15 -- 0.3)M ammonium fluoride, 0.07 M of iron(III) ion and 0.05 M of hydrochloric acid. An excess of the additives decreased the absorption. The presence of zirconium, which caused a significant interference in the ordinary analytical methods, did not affect the absorption due to hafnium, if the zirconium concentration is less than 0.2 M. A standard procedure was proposed; A sample containing a few mg of hafnium was dissolved in a 25-ml volumetric flask, and ammonium fluoride, ferric nitrate and hydrochloric acid were added so that the final concentrations were 0.3, 0.07 and 0.05 M, respectively. Atomic absorption was measured on the aqueous solution in a nitrous oxide-acetylene flame and the hafnium content was calculated from the absorbance. Sensitivity was as high as 12.5 μg of Hf/ml/l% absorption. The present method is especially recommendable to the direct determination of hafnium in samples containing zirconium. (auth.)

A new Technique for ultrafast velocity distribution measurements of atomic species by post-ionization laser induced fluorescence (PILIF)

International Nuclear Information System (INIS)

Tabares, F.L.

1992-01-01

A new method for single shot velocity distribution measurement of metallic impurities of relevance for studies involving continuous sources, such as limiter experiments in fusion devices or sputtering experiments, based in the combination of Resonant Enhanced Multiphoton Ionization (REMPI) and Laser Induced Fluorescence (LIF) is proposed. High ionization yield and good time resolution are expected according to the numerical simulation of the experiment that has been run for several atomic species. Other possible applications of REMPI to plasma edge physics and to conventional techniques for velocity distribution measurements are briefly addressed. (author)

A new technique for ultrafast velocity distribution measurements of atomic species by post-ionization laser induced fluorescent (PILIF)

International Nuclear Information System (INIS)

Tabares, F.L.

1992-01-01

A new method for single shot velocity distribution measurement of metallic impurities of relevance for studies involving continuous sources, such as limiter experiments in fusion devices or sputtering experiments, based in the combination of Resonant Enhanced Multiphoton ionization (REMPI) and Laser Induced Fluorescence (LIF) is proposed. High ionization yield and good time resolution are expected according to the numerical simulation of the experiment that has been run for several atomic species. Other possible applications of REMPI to plasma edge physics and to conventional techniques for velocity distribution measurements are briefly addressed. (Author) 8 refs

A new technique for ultrafast velocity distribution measurements of atomic species by post-ionization laser induced fluorescent (PILIF)

Energy Technology Data Exchange (ETDEWEB)

Tabares, F.L.

1992-07-01

A new method for single shot velocity distribution measurement of metallic impurities of relevance for studies involving continuous sources, such as limiter experiments in fusion devices or sputtering experiments, based in the combination of Resonant Enhanced Multiphoton ionization (REMPI) and Laser Induced Fluorescence (LIF) is proposed. High ionization yield and good time resolution are expected according to the numerical simulation of the experiment that has been run for several atomic species. Other possible applications of REMPI to plasma edge physics and to conventional techniques for velocity distribution measurements are briefly addressed. (Author) 8 refs.

Study of the heavy impurity influx into the plasma using laser fluorescence spectroscopy in the TO-2 tokamak with toroidal divertor

International Nuclear Information System (INIS)

Vukolov, K.Yu.; Shvindt, N.N.

1992-01-01

Measurement cycle for determination of iron atom absolute concentrations was carried out in divertor and diaphragm modes of laser fluorescence spectroscopy. The conclusion is made on effective wall shielding by divertor layer as compared to material diaphragm. The basic result of the work consists in creating and testing on the tokamak TO-2 of multichannel diagnostic complex for remote measurement of atom (ion) absolute concentrations of metallic impurities in the near-wall plasma with high spatial and time resolution through laser fluorescence spectroscopy method intended for studies at the Tokamak-15 facility

Comparison of fluorescence-enhancing reagents and optimization of laser fluorimetric technique for the determination of dissolved uranium

International Nuclear Information System (INIS)

Ceren Kuetahyali; Joaquin Cobos; Rondinella, V.V.

2011-01-01

Results from tests aimed at optimizing an instrumental procedure for the direct and fast determination of uranium in solution by laser fluorescence are presented. A comparison of sample fluorescence measured using different fluorescence enhancing reagents was performed: sodium pyrophosphate, orthophosphoric acid, sulphuric acid and a commercially available fluorescence enhancer were tested for the determination of uranium. From the experimental results, 0.01 M Na 4 P 2 O 7 x 10H 2 O showed the best performance. Effects of reagent pH, different matrices, different concentrations of dissolved Th, and sample volume were investigated. Applications of the improved procedure for the determination of uranium in samples arising from UO 2 -based high level nuclear waste dissolution studies are described. (author)

An x ray scatter approach for non-destructive chemical analysis of low atomic numbered elements

Science.gov (United States)

Ross, H. Richard

1993-01-01

A non-destructive x-ray scatter (XRS) approach has been developed, along with a rapid atomic scatter algorithm for the detection and analysis of low atomic-numbered elements in solids, powders, and liquids. The present method of energy dispersive x-ray fluorescence spectroscopy (EDXRF) makes the analysis of light elements (i.e., less than sodium; less than 11) extremely difficult. Detection and measurement become progressively worse as atomic numbers become smaller, due to a competing process called 'Auger Emission', which reduces fluorescent intensity, coupled with the high mass absorption coefficients exhibited by low energy x-rays, the detection and determination of low atomic-numbered elements by x-ray spectrometry is limited. However, an indirect approach based on the intensity ratio of Compton and Rayleigh scattered has been used to define light element components in alloys, plastics and other materials. This XRS technique provides qualitative and quantitative information about the overall constituents of a variety of samples.

A dihydrazone based fluorescent probe for selective determination of Al{sup 3+} ions

Energy Technology Data Exchange (ETDEWEB)

Pratap Singh, Divya; Singh, Vinod P., E-mail: singvp@yahoo.co.in

2014-11-15

A highly selective fluorescent sensor N,N′-bis((2-hydroxynaphthalen-1-yl)methylene) oxalohydrazide (H{sub 2}ohn) for the determination of Al{sup 3+} ions was synthesized and characterized by different physico-chemical and spectroscopic techniques. The single crystal structure of H{sub 2}ohn receptor has also been reported. The H{sub 2}ohn shows an enhanced fluorescence in the presence of Al{sup 3+} ions in ethanol–water (2:3 v/v) solution. Other cations viz. Na{sup +}, K{sup +}, Mg{sup 2+}, Ca{sup 2+}, Mn{sup 2+}, Fe{sup 3+}, Co{sup 2+}, Ni{sup 2+}, Cu{sup 2+}, Zn{sup 2+}, Pb{sup 2+}, Cd{sup 2+} and Hg{sup 2+} show no appreciable change in fluorescence intensity. The binding mode of H{sub 2}ohn receptor with Al{sup 3+} was studied by UV–visible, fluorescence and {sup 1}H NMR titrations. The receptor acts as a dibasic hexadentate ligand and interacts with two Al{sup 3+} ions with a high binding constant K{sub B}=2.62×10{sup 11} M{sup −2}. The lowest detection limit for Al{sup 3+} complex of H{sub 2}ohn was determined to be 8.56×10{sup −10} M. The structures of H{sub 2}ohn and its Al(III) complex were also optimized by DFT calculations. - Highlights: • A dihydrazone based fluorescent sensor is synthesized. • Characterized by IR, NMR, UV−visible and mass spectral analysis. • The receptor serves as a selective fluorescent sensor for Al{sup 3+} over other cations. • The sensing property is monitored by UV−visible, fluorescence and NMR spectroscopy. • A high binding constant of the receptor with Al{sup 3+} is reported here.

Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

Energy Technology Data Exchange (ETDEWEB)

Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K. (Abbott Laboratories, Department 90M, Abbott Park, IL (United States))

1991-01-01

Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates.

Characterization of antibody-chelator conjugates: Determination of chelator content by terbium fluorescence titration

International Nuclear Information System (INIS)

Brandt, K.D.; Schnobrich, K.E.; Johnson, D.K.

1991-01-01

Fluorescence titrations were performed by adding varying mole ratios of terbium(III) to antibody conjugates formed by benzyl isothiocyanate derivatives of three different polyaminopolycarboxylate chelators (NTA, EDTA, and DTPA) and the results compared to values for average chelator content obtained by cobalt-57 binding assays. For two different murine monoclonal antibodies, the average chelator content obtained by terbium fluorescence titration correlated closely with that measured by the cobalt-57 binding assay. It is concluded that lanthanide fluorescence titrations provide a useful alternative to radiometal binding assays for the determination of chelator content in protein-chelator conjugates

Laser fluorescence on radioactive isotopes produced in very low yield

International Nuclear Information System (INIS)

Wells, S.A.; Evans, D.E.; Griffith, J.A.R.; Eastham, D.A.; Groves, J.; Tolfree, D.W.L.; Warner, D.D.; Dancy, M.P.; Billowes, J.; Grant, I.S.; Walker, P.M.

1990-01-01

Heavy ion accelerators such as the NSF at Daresbury Laboratory are capable of producing a wide variety of radio-active beams. The intensities of the beams of atoms or ions are always modest, and ultra-sensitive methods are needed to observe laser-induced fluorescence. The fast ion-photon coincidence technique has been applied to neutron-deficient barium ions down to 120 Ba. Nuclear moments and changes in charge radii have been determined from the measured hyperfine splittings and isotope shifts. An abrupt increase in the mean square radius is observed at 121 Ba, large enough to disrupt the systematic staggering seen for the isotopic series. The hyperfine structure has also been observed for an isomeric state of 127 Ba which has a lifetime of about 2 seconds. The measurements lead to an unambiguous assignment of the spin of the isomer. Another technique has been tested with stable krypton atoms. Fluorescent photons in the VUV wavelength region are detected with a high efficiency using a channel plate detector. The background is small enough that it should be possible to measure hyperfine spectra on beams with fewer than 10 3 atoms per second

Fluorescence uranium determination; Determinacion de uranio por fluorescencia. I. Proyecto de equipo y comprobacion

Energy Technology Data Exchange (ETDEWEB)

Fernandez Cellini, R; Crus Castillo, F. de la; Barrera Pinero, R

1960-07-01

An equipment for analysis of uranium by fluorescence was developed in order to determine it at such a low concentration that it can not be determined by the most sensible analytical methods. this new fluorimeter was adapted to measure the fluorescence emitted by the phosphorus sodium fluoride-sodium carbonate-potasium carbonate-uranyl, being excited by ultraviolet light of 3,650 A the intensity of the light emitted was measure with a photomultiplicator RCA 5819 and the adequate electronic equipment. (Author) 19 refs.

Evaluation of field-portable X-ray fluorescence spectrometry for the determination of lead contamination on small-arms firing ranges

Energy Technology Data Exchange (ETDEWEB)

Schneider, J.F.; Taylor, J.D.; Bass, D.A.; Zellmer, D. [Argonne National Lab., IL (United States); Rieck, M. [U.S. Army, Grafenwoehr Training Area (Germany)

1995-02-01

Field analytical methods for the characterization of lead contamination in soil are being developed. In this study, the usefulness of a commercially available, field-portable energy-dispersive X-ray fluorescence spectrometer (XRF) is evaluated for determining the extent of lead contamination in soils on small-arms firing ranges at a military installation. This field screening technique provides significant time and cost savings for the study of sites with lead-contaminated soil. Data obtained with the XRF unit in the field are compared with data obtained from soil samples analyzed in an analytical laboratory by inductively coupled plasma atomic emission spectroscopy. Results indicate that the field-portable XRF unit evaluated in this study provides data that are useful in determining the extent and relative magnitude of lead contamination. For the commercial unit used in this study, improvements in the spectral resolution and in the limit of detection would be required to make the unit more than just a screening tool.

Application of Atomic Fluorescence to Measurement of Combustion Temperature in Solid Propellants.

Science.gov (United States)

1986-12-04

into a cytal (yttrium- aluminum -garnet) is shown to be an ideal seed, the fluoresce. f which is stimulated by the ultra-violet output of a Nd:YAG...been successfully employed in atmospheric flames for making thermometric measurements. However, because of the amorphous nature of energetic materials...be determined. R. 6 A .6 An example of this type of behavior is found in trivalent dysprosium, doped at 3% in yttrium- aluminum -garnet (Dy+3 :YAG

Mercury speciation by high-performance liquid chromatography atomic fluorescence spectrometry using an integrated microwave/UV interface. Optimization of a single step procedure for the simultaneous photo-oxidation of mercury species and photo-generation of Hg{sup 0}

Energy Technology Data Exchange (ETDEWEB)

Quadros, Daiane P.C. de [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); Campanella, Beatrice; Onor, Massimo; Bramanti, Emilia [National Research Council of Italy, C.N.R., Instituto di Chimica dei Composti Organo Metallici – ICCOM – UOS Pisa, Area della Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Borges, Daniel L.G. [Departamento de Química, Universidade Federal de Santa Catarina, 88040-970 Florianópolis, SC (Brazil); D' Ulivo, Alessandro, E-mail: dulivo@pi.iccom.cnr.it [National Research Council of Italy, C.N.R., Instituto di Chimica dei Composti Organo Metallici – ICCOM – UOS Pisa, Area della Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy)

2014-11-01

We described the hyphenation of photo-induced chemical vapor generation with high performance liquid chromatography–atomic fluorescence spectrometry (HPLC–AFS) for the quantification of inorganic mercury, methylmercury (MeHg) and ethylmercury (EtHg). In the developed procedure, formic acid in mobile phase was used for the photodecomposition of organomercury compounds and reduction of Hg{sup 2+} to mercury vapor under microwave/ultraviolet (MW/UV) irradiation. We optimized the proposed method studying the influence of several operating parameters, including the type of organic acid and its concentration, MW power, composition of HPLC mobile phase and catalytic action of TiO{sub 2} nanoparticles. Under the optimized conditions, the limits of detection were 0.15, 0.15 and 0.35 μg L{sup −1} for inorganic mercury, MeHg and EtHg, respectively. The developed method was validated by determination of the main analytical figures of merit and applied to the analysis of three certified reference materials. The online interfacing of liquid chromatography with photochemical-vapor generation–atomic fluorescence for mercury determination is simple, environmentally friendly, and represents an attractive alternative to the conventional tetrahydroborate (THB) system. - Highlights: • Inorganic and organic mercury were determined by photochemical vapor generation using a MW/UV photochemical reactor. • The optimized procedure has been applied to the speciation of Hg(II), MeHg and EtHg coupling HPLC with PVG–AFS. • The proposed method is simple, sensitive, and is established for mercury determination in biological materials.

Determination of uranium in geologic materials by laser-excited fluorescence

International Nuclear Information System (INIS)

McHugh, J.B.

1982-01-01

A laser-excited fluorescence method is described for the determination of trace amounts of uranium in rocks and soils. The limit of detection is less than 1 ppm, and the relative standard deviation ranges from 2.6 to 12.5%. The method was evaluated by using known geological reference samples

Single atom oscillations

International Nuclear Information System (INIS)

Wiorkowski, P.; Walther, H.

1990-01-01

Modern methods of laser spectroscopy allow the study of single atoms or ions in an unperturbed environment. This has opened up interesting new experiments, among them the detailed study of radiation-atom coupling. In this paper, the following two experiments dealing with this problem are reviewed: the single-atom maser and the study of the resonance fluorescence of a single stored ion. The simplest and most fundamental system for studying radiation-matter coupling is a single two-level atom interacting with a single mode of an electromagnetic field in a cavity. This problem received a great deal of attention shortly after the maser was invented

X-ray fluorescence in some medium-Z elements excited by 59.5 keV photons

International Nuclear Information System (INIS)

Han, I.; Shahin, M.; Demir, L.; Narmanli, E.

2010-01-01

K X-ray fluorescence parameters cross sections and average shell fluorescence yields) for selected ten elements in the atomic range 42 ≤ Z ≤ 66 have been experimentally determined at photon excitation energy of 59.5 keV. K X-rays emitted from the samples have been counted by a Si (Li) detector. The K spectra for investigated elements have been derived from the measured K shell X-ray spectra by peak fitting process. Experimental results of K X-ray fluorescence parameters have been compared with theory. In general there is an agreement within the standard uncertainties of the experimental and theoretical values

Use of electrothermal atomization for determining metallic impurities in nuclearly pure uranium compounds

International Nuclear Information System (INIS)

Franco, M.B.

1986-01-01

Atomic absorption spectrometry with electrothermal atomization was used for the determination of Al, Cd, Cr, Fe, Mn, Mo and Ni as impurities in uranium oxide samples. The determinations were performed in solubilized samples both with and without uranium separation as well as in solid samples. (Author) [pt

Use of electrothermal atomization for determining metallic impurities in nuclearly pure uranium compounds

International Nuclear Information System (INIS)

Franco, M.B.

1985-01-01

Atomic absorption spectrometry with electrothermal atomization was used for the determination of Al, Cd, Cr, Fe, Mn, Mo and Ni as impurities in uranium oxide samples. The determinations were performed in solubilized samples both with and without uranium separation as well as in solid samples. (Author) [pt

Response of Substituted Indoleacetic Acids in the Indolo-alpha-pyrone Fluorescence Determination

DEFF Research Database (Denmark)

Engvild, Kjeld Christensen; Böttger, M.; Kaiser, P.

1978-01-01

.-pyrones. Other halogenated indoleacetic acids show between zero and 60% of the fluorescence of IAA. Apparently the concentration of IAA cannot be determined in crude extracts in the presence of 4-chloro- or 5-hydroxy-indoleacetic acid, because separate determinations of each of these compounds are not possible...

Determination of some variables of human dentin for dosimetric purposes

International Nuclear Information System (INIS)

Peres, C.

1990-01-01

The initial objective of this work is to determine the atomic composition of human dentin, using various techniques of measurements such as X-Ray fluorescence, atomic absorption, spectrophotometry, volumetric analysis, chemistry, colorimetry and thermogravimetry. With the values of the effective atomic number Z bar dependent of the quality of the ionizing radiation, one can find the kind of material that can be used for a phantom equivalent to dentin. (author)

Critical tonicity determination of sperm using fluorescent staining and flow cytometry

Energy Technology Data Exchange (ETDEWEB)

Noiles, E.E.; Ruffing, N.A.; Kleinhans, F.W.; Mark, L.A.; Watson, P.F.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA)); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine); Mazur, P. (Oak Ridge National Lab., TN (USA))

1990-01-01

The use of cryopreserved, rather than fresh, mammalian semen for artificial insemination confers several important medical and/or economic advantages. However, current methods for cryopreservation of both human and bovine spermatozoa result in approximately only a 50% survival rate with thawing, obviously reducing the fertilizing capacity of the semen. A primary consideration during the cooling process is to avoid intracellular ice crystal formation with its lethal consequences to the cell. Current techniques achieve this by controlling the cooling rate. Computation of the time necessary for this dehydration, and hence, the cooling rate, is dependent upon knowledge of the water permeability coefficient (L{sub {rho}}) and its activation energy. The fluorophore, 6-carboxyfluoroscein diacetate (CFDA), which is nonfluorescent, readily crosses the intact plasma membrane. Intracellular esterases hydrolyze CFDA to 6-carboxyfluoroscein, a fluorescent, membrane-impermeable fluorophore. Consequently, spermatozoa with intact plasma membranes fluoresce bright green (Garner et. al., 1986), but those with disrupted membranes do not. Therefore, the purpose of this study was to use loss of CFDA fluorescence to determine the osmolality at which 50% of the spermatozoa will swell and lyse (critical tonicity, CT). These data will then be used to determine the L{sub {rho}} and its activation energy for sperm, thus increasing the knowledge available in cellular cryopreservation. 15 refs., 3 figs.

Impurity monitoring by laser-induced fluorescence techniques

International Nuclear Information System (INIS)

Gelbwachs, J.A.

1984-01-01

Laser-induced fluorescence spectroscopy can provide a highly sensitive and selective means of detecting atomic and ionic impurities. Because the photodetector can be physically isolated from the laser-excited region, these techniques can be applied to monitoring in hostile environments. The basic concepts behind fluorescence detection are reviewed. Saturated optical excitation is shown to maximize impurity atom emission yield while mitigating effects of laser intensity fluctuations upon absolute density calibration. Monitoring in high- and low-pressure monitoring environments is compared. Methods to improve detection sensitivity by luminescence background suppression are presented

Determination of atomic number and composition of human enamel

International Nuclear Information System (INIS)

Nogueira, M.S.; Rodas Duran, J.E.

2001-01-01

The teeth are organs of complicated structure that consist, partly, of hard tissue containing in its interior the dental pulp, rich in vases and nerves. The main mass of the tooth is constituted by the dentine, which is covered with hard tissues and of epithelial origin called enamel. The dentine of the human teeth used in this work were completely removed and the teeth were cut with a device with a diamond disc. In this work the chemical composition of the human enamel was determined, which showed a high percentage of Ca and P, in agreement with the results found in the literature. The effective atomic number of the material and the half-value layer in the energy range of diagnostic X-ray beams were determined. Teeth could be used to evaluated the public's individual doses as well as for retrospective dosimetry what confirms the importance of their effective atomic number and composition determination. (author)

Sequential determination of nickel and cadmium in tobacco, molasses and refill solutions for e-cigarettes samples by molecular fluorescence.

Science.gov (United States)

Talio, María Carolina; Alesso, Magdalena; Acosta, Mariano; Wills, Verónica S; Fernández, Liliana P

2017-11-01

In this work, a new procedure was developed for separation and preconcentration of nickel(II) and cadmium(II) in several and varied tobacco samples. Tobacco samples were selected considering the main products consumed by segments of the population, in particular the age (youth) and lifestyle of the consumer. To guarantee representative samples, a randomized strategy of sampling was used. In the first step, a chemofiltration on nylon membrane is carried out employing eosin (Eo) and carbon nanotubes dispersed in sodium dodecylsulfate (SDS) solution (phosphate buffer pH 7). In this condition, Ni(II) was selectively retained on the solid support. After that, the filtrate liquid with Cd(II) was re-conditioned with acetic acid /acetate buffer solution (pH 5) and followed by detection. A spectrofluorimetric determination of both metals was carried out, on the solid support and the filtered aqueous solution, for Ni(II) and Cd(II), respectively. The solid surface fluorescence (SSF) determination was performed at λ em = 545nm (λ ex = 515nm) for Ni(II)-Eo complex and the fluorescence of Cd(II)-Eo was quantified in aqueous solution using λ em = 565nm (λ ex = 540nm). The calibration graphs resulted linear in a range of 0.058-29.35μgL -1 for Ni(II) and 0.124-56.20μgL -1 for Cd(II), with detection limits of 0.019 and 0.041μgL -1 (S/N = 3). The developed methodology shows good sensitivity and adequate selectivity, and it was successfully applied to the determination of trace amounts of nickel and cadmium present in tobacco samples (refill solutions for e-cigarettes, snuff used in narguille (molasses) and traditional tobacco) with satisfactory results. The new methodology was validated by ICP-MS with adequate agreement. The proposed methodology represents a novel fluorescence application to Ni(II) and Cd(II) quantification with sensitivity and accuracy similar to atomic spectroscopies, introducing for the first time the quenching effect on SSF. Copyright © 2017 Elsevier B

X-Ray fluorescence determination of the mobile forms of toxic elements in meadow chernozems

International Nuclear Information System (INIS)

Belikov, K.N.; Blank, A.B.; Shevtsov, N.I.

1997-01-01

An X-ray fluorescence method for determining mobile forms of Mn, V, Cr, Co, Ni, Zn, and Pb in meadow chernozems was developed. It is based on the extraction of analytes with an acetate-ammonia buffer solution and the evaporation of the obtained filtrate with carbon powder followed by the X-ray fluorescence analysis of the dry residue. The effect of concomitants on the analytical signals of elements under determination was examined. It was suggested to spike samples with barium in order to decrease analytical errors. (author)

Determination of trace elements in atomic absorption spectrophotometry. Study of the atomic cloud and atom generator. Application to the measurement of physical quantities

International Nuclear Information System (INIS)

Hircq, Bernard.

1976-06-01

After the description of the absorption cell the principal parameters are studied: argon flow rate in the cell, atomization temperature, cell geometry etc. The technique is applied to the measurement of impurities in uranium after deposition on a carbon filament. The atomic concentration distribution and the dimensions of the cloud generated by a graphite filament are then studied along the axes parallel to the filament and as a function of the various experimental parameters. From the determination of the cloud elevation rate it is possible to calculate the absolute atomic concentration, which allows certain physical quantities to be evaluated: oscillator force, Lorentz Widening, diffusion coefficient... The size and penetration depth of the deposit are then determined with an ionic microprobe and the distribution with a Castaing microprobe. The chemical transformations undergone by the uranium matrix during the heat cycles are studied by the X-ray method [fr

Structural characterization of the photoswitchable fluorescent protein Dronpa-C62S

International Nuclear Information System (INIS)

Nam, Ki-Hyun; Kwon, Oh Yeun; Sugiyama, Kanako; Lee, Won-Ho; Kim, Young Kwan; Song, Hyun Kyu; Kim, Eunice Eunkyung; Park, Sam-Yong; Jeon, Hyesung; Hwang, Kwang Yeon

2007-01-01

The photoswitching behavior of green fluorescent proteins (GFPs) or GFP-like proteins is increasingly recognized as a new technique for optical marking. Recently, Ando and his colleagues developed a new green fluorescent protein Dronpa, which possesses the unique photochromic property of being photoswitchable in a non-destructive manner. To better understand this mechanism, we determined the crystal structures of a new GFP Dronpa and its mutant C62S, at 1.9 A and 1.8 A, respectively. Determination of the structures demonstrates that a unique hydrogen-bonding network and the sulfur atom of the chromophore are critical to the photoswitching property of Dronpa. Reversible photoswitching was lost in cells expressing the Dronpa-C62S upon repetitive irradiation compared to the native protein. Structural and mutational analyses reveal the chemical basis for the functional properties of photoswitchable fluorescent proteins and provide the basis for subsequent coherent engineering of this subfamily of Dronpa homolog's

Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex

Directory of Open Access Journals (Sweden)

Pilar Santolaria

2016-01-01

Full Text Available This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively. Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P < 0.001 although with important differences between bulls. A simultaneous evaluation of all the measured features by discriminant analysis revealed that nuclear area and average fluorescence intensity were the variables selected by stepwise discriminant function analysis as the best discriminators between SX and SY. In the second experiment, the sperm nuclear morphometric results from CASA-Morph in nonsexed (mixed SX and SY and sexed (SX semen samples from four bulls were compared. FISH allowed a successful classification of spermatozoa according to their sex chromosome content. X-sexed spermatozoa displayed a larger size and fluorescence intensity than nonsexed spermatozoa (P < 0.05. We conclude that the CASA-Morph fluorescence-based method has the potential to find differences between X- and Y-chromosome-bearing spermatozoa in bovine species although more studies are needed to increase the precision of sex determination by this technique.

Quantitative determination of uranium in organic solution by X-ray fluorescence

International Nuclear Information System (INIS)

Leyt, D.V. de; Colangelo, C.H.

1987-01-01

An X-ray fluorescent method for the determination of uranium in tributilphosphate-kerosene-nitriacid solution has been developed. Chemical properties of the matrix elements were studied in order to select a convenient procedure to determine samples and standards on the same way. The method avoids the destruction of the organic material and has proved to be very useful for the fast control of uranium concentration. (Author) [es

Continuous magnetic trapping of laser cooled atoms

International Nuclear Information System (INIS)

Bagnato, V.S.; Lafyatis, G.; Martin, A.G.; Raab, E.L.; Landry, J.; Ahmad-Bitar, R.N.; Pritchard, D.E.

1987-01-01

The authors present here initial results of the deceleration of a thermal atomic beam from -- 1000 to -- 100 m/s. The experiment was conducted in the 1.4-m long vertical superconducting solenoid which produced the slowing field. The fluorescence of the slowed atomic beam has been studied as a function of laser frequency. Figure 2 is a 12-GHz scan showing the fluorescence at a position 150 cm from the beginning of the solenoid. The wide peak corresponds to unslowed atoms with generally the initial velocity distribution. The second, narrower, peak corresponds to slowed atoms with a velocity of -- 150 m/s. Similar spectra have been obtained for various positions along the magnetic slower and trap. These data should allow better understanding of the cooling process and will be compared to computer models

Laser fluorescent diagnostics of a plasma of combustion products with an alkali additive

International Nuclear Information System (INIS)

Mokhov, A.V.; Nefedov, A.P.

1993-01-01

Methods of laser fluorescent determination of sodium atom and hydroxyl molecule (impurity fire component) concentration are described. A method of wide-band detection is presented in detail. A monochromator, its transmission band allowing one to detect all rotational lines of hydroxyl electron-vibrational transition, is used as wide-bond filter. High efficiency of using the methods described in studying the combustion chemistry, kinetics of sodium atom compound production in combustion product plasma and pre-electrode processes is demonstrated. 95 refs., 12 figs., 4 tabs

THE EVOLUTION OF ATOMIC SPECTROSCOPY IN MEASURING TOXIC CONTAMINANTS

Science.gov (United States)

Three decades of study of environmental conditions necessary for the protection of freshwateraquatic life have been limited by the development and application of analytical methodology utilizing atomic adsorption, atomic fluorescence, and atomic emission spectroscopy.The...

Fluorescent sensing and determination of mercury (II) ions in water ...

African Journals Online (AJOL)

In this study we report on a fluorescent sensing probe based on a naphthyl azo dye modified dibenzo-18-crown-6-ether (DB18C6) for the detection and determination of mercury (II) ions in water. The probe showed high sensitivity and selectivity towards the mercury (II) ion among various alkali, alkaline earth, and transition ...

Development of glancing-incidence and glancing-take-off X-ray fluorescence apparatus for surface and thin-film analyses

International Nuclear Information System (INIS)

Tsuji, Kouichi; Wagatsuma, Kazuaki; Yamada, Takashi; Utaka, Tadashi

1997-01-01

We have studied X-ray fluorescence analysis under glancing incidence and glancing take-off conditions. Recently, we have developed a third apparatus for detecting glancing-incidence and take-off X-ray fluorescence, which makes it possible to measure the incident-angle dependence, the take-off-angle dependence. X-ray reflectivity, and X-ray diffraction. Primarily, we have measured the take-off angular dependence of X-ray fluorescence using this apparatus. Glancing take-off X-ray fluorescence has some advantages in comparison with glancing-incidence X-ray fluorescence. The surface density and the absolute angles were determined by analysing the take-off angle dependence of the fluorescent X-rays emitted from identical atoms with the aid of the reciprocity theorem. (Author)

Blood selenium content determination by X-ray fluorescence

International Nuclear Information System (INIS)

Mainardi, R.T.

1987-01-01

The presence of some elements in small amounts (traces) in the human body is of foremost importance for the prevention and treatment of several diseases. It has been recently shown that traces of selenium in blood are closely related to the occurrence of miotonic distrophy, a muscular disease that is affecting a significant percentage of the population. This work describes a simple procedure to determine selenium in human blood serum by energy dispersive X-ray fluorescence analysis. Final quantification is achieved through the addition of titanium as an internal standard. (Author) [es

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.

Simultaneous determination of total arsenic and total selenium in Chinese medicinal herbs by hydride generation atomic fluorescence spectrometry in tartaric acid medium

International Nuclear Information System (INIS)

Liu Zhanfeng; Sun Hanwen; Shen Shigang; Li Liqing; Shi Hongmei

2005-01-01

By HG-AFS, a new method was proposed for simultaneous determination of total arsenic and total selenium existed in the Chinese medicinal herbs in tartaric acid medium. The effects of analytical conditions and coexisting ions on the fluorescence signal intensity of analytes were investigated. The proposed method was provided with linear response ranges above 22 μg l -1 for As and 44 μg l -1 for Se, and the detection limits of 0.13 and 0.12 μg l -1 were obtained for As and Se respectively. The recoveries of 93.8-96.1% for As and 95.3-99.1% for Se, and the precision of 1.2-3.8% and 2.4-5.3% (R.S.D., n = 8) respectively, were obtained via simultaneous determined four samples of Chinese medicinal herbs and three certified botanic reference materials successfully. The proposed method has the advantages of simple operation, high sensitivity and high efficiency

Analysis of Indium Tin Oxide Film Using Argon Fluroide (ArF) Laser-Excited Atomic Fluorescence of Ablated Plumes.

Science.gov (United States)

Ho, Sut Kam; Garcia, Dario Machado

2017-04-01

A two-pulse laser-excited atomic fluorescence (LEAF) technique at 193 nm wavelength was applied to the analysis of indium tin oxide (ITO) layer on polyethylene terephthalate (PET) film. Fluorescence emissions from analytes were induced from plumes generated by first laser pulse. Using this approach, non-selective LEAF can be accomplished for simultaneous multi-element analysis and it overcomes the handicap of strict requirement for laser excitation wavelength. In this study, experimental conditions including laser fluences, times for gating and time delay between pulses were optimized to reveal high sensitivity with minimal sample destruction and penetration. With weak laser fluences of 100 and 125 mJ/cm 2 for 355 and 193 nm pulses, detection limits were estimated to be 0.10% and 0.43% for Sn and In, respectively. In addition, the relation between fluorescence emissions and number of laser shots was investigated; reproducible results were obtained for Sn and In. It shows the feasibility of depth profiling by this technique. Morphologies of samples were characterized at various laser fluences and number of shots to examine the accurate penetration. Images of craters were also investigated using scanning electron microscopy (SEM). The results demonstrate the imperceptible destructiveness of film after laser shot. With such weak laser fluences and minimal destructiveness, this LEAF technique is suitable for thin-film analysis.

Determination of coal ash content by the combined x-ray fluorescence and scattering spectrum

Science.gov (United States)

Mikhailov, I. F.; Baturin, A. A.; Mikhailov, A. I.; Borisova, S. S.; Fomina, L. P.

2018-02-01

An alternative method is proposed for the determination of the inorganic constituent mass fraction (ash) in solid fuel by the ratio of Compton and Rayleigh X-ray scattering peaks IC/IR subject to the iron fluorescence intensity. An original X-ray optical scheme with a Ti/Mo (or Sc/Cu) double-layer secondary radiator allows registration of the combined fluorescence-and-scattering spectrum at the specified scattering angle. An algorithm for linear calibration of the Compton-to-Rayleigh IC/IR ratio is proposed which uses standard samples with two certified characteristics: mass fractions of ash (Ad) and iron oxide (WFe2O3). Ash mass fractions have been determined for coals of different deposits in the wide range of Ad from 9.4% to 52.7% mass and WFe2O3 from 0.3% to 4.95% mass. Due to the high penetrability of the probing radiation with energy E > 17 keV, the sample preparation procedure is rather simplified in comparison with the traditional method of Ad determination by the sum of fluorescence intensities of all constituent elements.

Synchronizing atomic force microscopy force mode and fluorescence microscopy in real time for immune cell stimulation and activation studies

Energy Technology Data Exchange (ETDEWEB)

Cazaux, Séverine; Sadoun, Anaïs; Biarnes-Pelicot, Martine; Martinez, Manuel; Obeid, Sameh [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Bongrand, Pierre [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); APHM, Hôpital de la Conception, Laboratoire d’Immunologie, Marseille F-13385 (France); Limozin, Laurent [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France); Puech, Pierre-Henri, E-mail: pierre-henri.puech@inserm.fr [Aix Marseille Université, LAI UM 61, Marseille F-13288 (France); Inserm, UMR-S 1067, Marseille F-13288 (France); CNRS, UMR 7333, Marseille F-13288 (France)

2016-01-15

A method is presented for combining atomic force microscopy (AFM) force mode and fluorescence microscopy in order to (a) mechanically stimulate immune cells while recording the subsequent activation under the form of calcium pulses, and (b) observe the mechanical response of a cell upon photoactivation of a small G protein, namely Rac. Using commercial set-ups and a robust signal coupling the fluorescence excitation light and the cantilever bending, the applied force and activation signals were very easily synchronized. This approach allows to control the entire mechanical history of a single cell up to its activation and response down to a few hundreds of milliseconds, and can be extended with very minimal adaptations to other cellular systems where mechanotransduction is studied, using either purely mechanical stimuli or via a surface bound specific ligand. - Highlights: • A signal coupling AFM and fluorescence microscopy was characterized for soft cantilevers. • It can be used as an intrinsic timer to synchronize images and forces. • Mechanical stimulation of single immune cells while recording calcium fluxes was detailed. • Light-induced mechanical modifications of lymphocytes using a PA-Rac protein were demonstrated. • The precautions and limitations of use of this effect were presented.

The determination of zirconium by atomic absorption spectrophotometry

International Nuclear Information System (INIS)

Rodriguez, E.R.; Cunha, M.T.C. da

1975-01-01

The interference of iron in the determination of zirconium by atomic absorption spectrophotometry was studied. Attempts were made to emininate this interference by complexing the iron with EDTA, ascorbic acid and hydrazine; also by the addition of ammonium fluoride to the solution. Some experiments were carried out in order to explain the results obtained [pt

Fluorescence and Four-Wave Mixing in Electromagnetically Induced Transparency Windows

International Nuclear Information System (INIS)

Wang Zhi-Guo; Li Cheng; Zhang Zhao-Yang; Che Jun-Ling; Qin Meng-Zhe; He Jia-Nan; Zhang Yan-Peng

2013-01-01

We simultaneously compare the probe transmission, Four-Wave Mixing (FWM) and fluorescence signals with dressing effects in a four-level atomic system. The variation rules of three types of signals are exhibited by changing the frequency detuning and power of incident laser beams. The interplay between two ladder subsystems is investigated in the Y-type atomic system. In particular, the fluorescence signal with ultra-narrow linewidth is obtained due to being sheared twice by the electromagnetically induced transparency window. Such fluorescence with very high coherence and monochromaticity can be used for the quantum correlation and narrow linewidth laser

Morphing hydrogel patterns by thermo-reversible fluorescence switching.

Science.gov (United States)

Bat, Erhan; Lin, En-Wei; Saxer, Sina; Maynard, Heather D

2014-07-01

Stimuli responsive surfaces that show reversible fluorescence switching behavior in response to temperature changes were fabricated. Oligo(ethylene glycol) methacrylate thermoresponsive polymers with amine end-groups were prepared by atom transfer radical polymerization (ATRP). The polymers were patterned on silicon surfaces by electron beam (e-beam) lithography, followed by conjugation of self-quenching fluorophores. Fluorophore conjugated hydrogel thin films were bright when the gels were swollen; upon temperature-induced collapse of the gels, self-quenching of the fluorophores led to significant attenuation of fluorescence. Importantly, the fluorescence was regained when the temperature was cooled. The fluorescence switching behavior of the hydrogels for up to ten cycles was investigated and the swelling-collapse was verified by atomic force microscopy. Morphing surfaces that change shape several times upon increase in temperature were obtained by patterning multiple stimuli responsive polymers. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fast and accurate automated cell boundary determination for fluorescence microscopy

Science.gov (United States)

Arce, Stephen Hugo; Wu, Pei-Hsun; Tseng, Yiider

2013-07-01

Detailed measurement of cell phenotype information from digital fluorescence images has the potential to greatly advance biomedicine in various disciplines such as patient diagnostics or drug screening. Yet, the complexity of cell conformations presents a major barrier preventing effective determination of cell boundaries, and introduces measurement error that propagates throughout subsequent assessment of cellular parameters and statistical analysis. State-of-the-art image segmentation techniques that require user-interaction, prolonged computation time and specialized training cannot adequately provide the support for high content platforms, which often sacrifice resolution to foster the speedy collection of massive amounts of cellular data. This work introduces a strategy that allows us to rapidly obtain accurate cell boundaries from digital fluorescent images in an automated format. Hence, this new method has broad applicability to promote biotechnology.

Nanostructural origin of blue fluorescence in the mineral karpatite.

Science.gov (United States)

Potticary, Jason; Jensen, Torsten T; Hall, Simon R

2017-08-29

The colour of crystals is a function of their atomic structure. In the case of organic crystals, it is the spatial relationships between molecules that determine the colour, so the same molecules in the same arrangement should produce crystals of the same colour, regardless of whether they arise geologically or synthetically. There is a naturally-occurring organic crystal known as karpatite which is prized for its beautiful blue fluorescence under ultra-violet illumination. When grown under laboratory conditions however, the crystals fluoresce with an intense green colour. For 20 years, this difference has been thought to be due to chemical impurities in the laboratory-grown material. Using electron microscopy coupled with fluorescence spectroscopy and X-Ray diffraction, we report here that this disparity is instead due to differences in the structure of the crystals at the nanoscale. The results show that in nature, karpatite has a nanotexture that is not present in the synthetic crystals, which enables different photonic pathways and therefore a blue, rather than green colour whilst undergoing fluorescence.

Comparison of sensitivities and detection limits between direct excitation and secondary excitation modes in energy dispersive x-ray fluorescence analysis

International Nuclear Information System (INIS)

Artz, B.E.; Short, M.A.

1976-01-01

A comparison was made between the direct tube excitation mode and the secondary target excitation mode using a Kevex 0810 energy dispersive x-ray fluorescence system. Relative sensitivities and detection limits were determined with two system configurations. The first configuration used a standard, high power, x-ray fluorescence tube to directly excite the specimen. Several x-ray tubes, including chromium, molybdenum, and tungsten, both filtered and not filtered, were employed. The second configuration consisted of using the x-ray tube to excite a secondary target which in turn excited the specimen. Appropriate targets were compared to the direct excitation results. Relative sensitivities and detection limits were determined for K-series lines for elements from magnesium to barium contained in a low atomic number matrix and in a high atomic number matrix

Ambient-Temperature Trap/Release of Arsenic by Dielectric Barrier Discharge and Its Application to Ultratrace Arsenic Determination in Surface Water Followed by Atomic Fluorescence Spectrometry.

Science.gov (United States)

Mao, Xuefei; Qi, Yuehan; Huang, Junwei; Liu, Jixin; Chen, Guoying; Na, Xing; Wang, Min; Qian, Yongzhong

2016-04-05

A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge.

Simulation study of two-energy X-ray fluorescence holograms reconstruction algorithm to remove twin images

International Nuclear Information System (INIS)

Xie Honglan; Hu Wen; Luo Hongxin; Deng Biao; Du Guohao; Xue Yanling; Chen Rongchang; Shi Shaomeng; Xiao Tiqiao

2008-01-01

Unlike traditional outside-source holography, X-ray fluorescence holography is carded out with fluorescent atoms in a sample as source light for holographic imaging. With the method, three-dimensional arrangement of atoms into crystals can be observed obviously. However, just like traditional outside-source holography, X-ray fluorescence holography suffers from the inherent twin-image problem, too. With a 27-Fe-atoms cubic lattice as model, we discuss in this paper influence of the photon energy of incident source in removing twin images in reconstructed atomic images by numerical simulation and reconstruction with two-energy X-ray fluorescence holography. The results indicate that incident X-rays of nearer energies have better effect of removing twin images. In the detector of X-ray holography, minimum difference of the two incident energies depends on energy resolution of the monochromator and detector, and for inside source X-ray holography, minimum difference of the two incident energies depends on difference of two neighboring fluorescent energies emitting from the element and energy resolution of detector. The spatial resolution of atomic images increases with the incident energies. This is important for experiments of X-ray fluorescence holography, which is being developed on Shanghai Synchrotron Radiation Facility. (authors)

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

Rate Constants and H-Atom Product Yields for the Reactions of O(1D) Atoms with Ethane and Acetylene from 50 to 296 K.

Science.gov (United States)

Nunez-Reyes, Dianailys; Hickson, Kevin M

2018-05-01

The gas phase reactions of atomic oxygen in its first excited state with ethane and acetylene have been investigated in a continuous supersonic flow reactor over the temperature range 50 K to 296 K. O(1D) atoms were produced by pulsed laser photolysis of ozone at 266 nm. Two different types of experiments, kinetics measurements and H-atom product yield determinations, were performed by detecting O(1D) atoms and H(2S) atoms respectively by vacuum ultraviolet laser induced fluorescence. The measured rate constants are in agreement with previous work at room temperature and little or no temperature dependence was observed as the temperature is decreased to 50 K. H-atoms yields were found to be independent of temperature for the reaction of O(1D) with ethane. These product yields are discussed in the context of earlier dynamics measurements at higher temperature. Due to the influence of secondary reactions, no H-atom yields could be obtained for the reaction of O(1D) with acetylene.

Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

Energy Technology Data Exchange (ETDEWEB)

Campos, Reinaldo C. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil)], E-mail: rccampos@puc-rio.br; Goncalves, Rodrigo A.; Brandao, Geisamanda P.; Azevedo, Marlo S. [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marques de S Vicente 225, 22453-900 Rio de Janeiro (Brazil); Oliveira, Fabiana; Wasserman, Julio [Institut of Geosciences, Fluminense Federal University, Av. Gal. Milton Tavares de Souza, s/n, 24.210-340, Niteroi, Rio de Janeiro (Brazil)

2009-06-15

The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C{sub 18} column was used as stationary phase, and post column treatment was performed by UV irradiation (60 deg. C, 13 W). The eluate was then merged with 3 mol L{sup -1} HCl, reduction was performed by a NaBH{sub 4} solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 {mu}g L{sup -1} were obtained for ionic (Hg{sup 2+}) and HgCH{sub 3}{sup +}, for an injection volume of 200 {mu}L. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sedi0011men.

Methylmercury determination using a hyphenated high performance liquid chromatography ultraviolet cold vapor multipath atomic absorption spectrometry system

International Nuclear Information System (INIS)

Campos, Reinaldo C.; Goncalves, Rodrigo A.; Brandao, Geisamanda P.; Azevedo, Marlo S.; Oliveira, Fabiana; Wasserman, Julio

2009-01-01

The present work investigates the use of a multipath cell atomic absorption mercury detector for mercury speciation analysis in a hyphenated high performance liquid chromatography assembly. The multipath absorption cell multiplies the optical path while energy losses are compensated by a very intense primary source. Zeeman-effect background correction compensates for non-specific absorption. For the separation step, the mobile phase consisted in a 0.010% m/v mercaptoethanol solution in 5% methanol (pH = 5), a C 18 column was used as stationary phase, and post column treatment was performed by UV irradiation (60 deg. C, 13 W). The eluate was then merged with 3 mol L -1 HCl, reduction was performed by a NaBH 4 solution, and the Hg vapor formed was separated at the gas-liquid separator and carried through a desiccant membrane to the detector. The detector was easily attached to the system, since an external gas flow to the gas-liquid separator was provided. A multivariate approach was used to optimize the procedure and peak area was used for measurement. Instrumental limits of detection of 0.05 μg L -1 were obtained for ionic (Hg 2+ ) and HgCH 3 + , for an injection volume of 200 μL. The multipath atomic absorption spectrometer proved to be a competitive mercury detector in hyphenated systems in relation to the most commonly used atomic fluorescence and inductively coupled plasma mass spectrometric detectors. Preliminary application studies were performed for the determination of methyl mercury in sediments.

Simultaneous determination of Magnolol and Honokiol by amino acid ionic liquid synchronous fluorescence spectrometry

Science.gov (United States)

Liu, Wei; Zhu, Xiashi

2018-05-01

A novel method based on amino acid ionic liquids (AAILs) as an additive synchronous fluorescence spectrometry is proposed for simultaneous determination of magnolol (MN) and honokiol (HN) in traditional Chinese medicine Houpu. The overlapping fluorescence spectrum of MN and HN could be completely separated in the AAILs medium. Experiment parameters (the type and concentration of AAILs, pH values and temperature) were discussed. The detection limits of MN and HN reached 1.46 ng/mL, 0.92 ng/mL and the recovery rates ranged from 98.6%-100.7%, 99.7%-100.6%, respectively. This methods was successfully employed for simultaneously determination of MN and HN in real samples. No significant differences could be found in the results of this method and the pharmacopoeia of People's Republic of China 2015 (Ch.P.2015). The experiment mechanisms were discussed by the Gaussian simulation and fluorescence quantum yield.

An X-ray fluorescence method for the determination of metals thicknesses

International Nuclear Information System (INIS)

Vazquez, Cristina; Leyt, D.V. de; Riveros, J.A.

1987-01-01

An absolute method for the determination of the thickness of a metal film deposited on a metallic substrate is described. The method is based on the measurement of fluorescent intensity ratios for two lines from the substrate element. Additionally, the proposed method can be employed to determine the density of the deposited material or the incident angle of primary radiation and take off angle, if the metal film thickness is known. (Author) [es

Modern atomic physics

CERN Document Server

Natarajan, Vasant

2015-01-01

Much of our understanding of physics in the last 30-plus years has come from research on atoms, photons, and their interactions. Collecting information previously scattered throughout the literature, Modern Atomic Physics provides students with one unified guide to contemporary developments in the field. After reviewing metrology and preliminary material, the text explains core areas of atomic physics. Important topics discussed include the spontaneous emission of radiation, stimulated transitions and the properties of gas, the physics and applications of resonance fluorescence, coherence, cooling and trapping of charged and neutral particles, and atomic beam magnetic resonance experiments. Covering standards, a different way of looking at a photon, stimulated radiation, and frequency combs, the appendices avoid jargon and use historical notes and personal anecdotes to make the topics accessible to non-atomic physics students. Written by a leader in atomic and optical physics, this text gives a state-of-the...

Recent advances in on-line coupling of capillary electrophoresis to atomic absorption and fluorescence spectrometry for speciation analysis and studies of metal-biomolecule interactions

International Nuclear Information System (INIS)

Li Yan; Yin Xuebo; Yan Xiuping

2008-01-01

Speciation information is vital for the understanding of the toxicity, mobility and bioavailability of elements in environmental or biological samples. Hyphenating high resolving power of separation techniques and element-selective detectors provides powerful tools for studying speciation of trace elements in environmental and biological systems. During the last five years several novel hybrid techniques based on capillary electrophoresis (CE) and atomic spectrometry have been developed for speciation analysis and metal-biomolecule interaction study in our laboratory. These techniques include CE on-line coupled with atomic fluorescence spectrometry (AFS), chip-CE on-line coupled with AFS, CE on-line coupled with flame heated quartz furnace atomic absorption spectrometry (FHF-AAS), and CE on-line coupled with electrothermal atomic absorption spectrometry (ETAAS). The necessity for the development of these techniques, their interface design, and applications in speciation analysis and metal-biomolecule interaction study are reviewed. The advantages and limitations of the developed hybrid techniques are critically discussed, and further development is also prospected

Ultratrace determination of lead by hydride generation in-atomizer trapping atomic absorption spectrometry: Optimization of plumbane generation and analyte preconcentration in a quartz trap-and-atomizer device

Energy Technology Data Exchange (ETDEWEB)

Kratzer, Jan, E-mail: jkratzer@biomed.cas.cz

2012-05-15

A compact trap-and-atomizer device and a preconcentration procedure based on hydride trapping in excess of oxygen over hydrogen in the collection step, both constructed and developed previously in our laboratory, were employed to optimize plumbane trapping in this device and to develop a routine method for ultratrace lead determination subsequently. The inherent advantage of this preconcentration approach is that 100% preconcentration efficiency for lead is reached in this device which has never been reported before using quartz or metal traps. Plumbane is completely retained in the trap-and-atomizer device at 290 Degree-Sign C in oxygen-rich atmosphere and trapped species are subsequently volatilized at 830 Degree-Sign C in hydrogen-rich atmosphere. Effect of relevant experimental parameters on plumbane trapping and lead volatilization are discussed, and possible trapping mechanisms are hypothesized. Plumbane trapping in the trap-and-atomizer device can be routinely used for lead determination at ultratrace levels reaching a detection limit of 0.21 ng ml{sup -1} Pb (30 s preconcentration, sample volume 2 ml). Further improvement of the detection limit is feasible by reducing the blank signal and increasing the trapping time. - Highlights: Black-Right-Pointing-Pointer In-atomizer trapping HG-AAS was optimized for Pb. Black-Right-Pointing-Pointer A compact quartz trap-and-atomizer device was employed. Black-Right-Pointing-Pointer Generation, preconcentration and atomization steps were investigated in detail. Black-Right-Pointing-Pointer 100% preconcentration efficiency for lead was reached. Black-Right-Pointing-Pointer Routine analytical method was developed for Pb determination (LOD of 0.2 ng ml{sup -1} Pb).

Nuclear-driven flashlamp pumping of the atomic iodine laser

International Nuclear Information System (INIS)

Miley, G.H.

1992-03-01

This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with 10 B and 3 He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C 3 F 7 I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation

Determination of cadmium in aluminium by atomic absorption spectrometry

International Nuclear Information System (INIS)

Batistoni, D.A.; Erlijman, L.H.

1978-12-01

A direct method for the determination of cadmium in elemental aluminium is described. Metal samples are dissolved in diluted hydrochloric acid and cadmium is determined by atomic absorption spectrometry in an air-acetylene flame. Interference by non-specific absorption observed at the analytical wavelength incorrected for by means of a non-absorbing line emitted by the hollow-cathode lamp. Relatively large amounts of arsenic do not interfere. The minimun determinable concentration of cadmium for this procedure is 2-3 ppm, expressed on aluminium basis. (author) [es

Determination of copper in geological materials by X-ray fluorescence

International Nuclear Information System (INIS)

Roca, M.; Bayon, A.

1981-01-01

X-ray fluorescence has been applied to the determination of copper content of geological materials in the concentration range of 0.01 to % CuO. A molybdenum target tube Is used, samples being presented in finely-ground powder form. Various methods for the correction for background and Instrumental copper interferences have been considered. To correct for matrix effects different tube scattered primary radiations have been tested as references or internal standards. MoK(41 - (C) provides the most suitable results. The use of influence empirical coefficients for the effect of iron on copper and of mass absorption coefficients has also been considered. For samples with a high content of lead, several procedures to correct for I t s influence have been investigated. Comparison between data obtained by X-ray fluorescence and wet-chemical techniques indicated good agreement. (Author) 6 refs

Rapid fluorometric determination of perfluorooctanoic acid by its quenching effect on the fluorescence of quantum dots

International Nuclear Information System (INIS)

Liu, Qi; Huang, Aizhen; Wang, Nan; Zheng, Guan; Zhu, Lihua

2015-01-01

Analysis of perfluorooctanoic acid (PFOA) usually requires a combination of high-performance liquid chromatography and mass spectrometry, which is expensive and time-consuming. In the present work, water-soluble CdS quantum dots (QDs) were employed to develop a simple and rapid fluorometric method for the determination of PFOA. Strongly fluorescent CdS QDs were prepared by using 3-mercaptopropionic acid (MPA) as a stabilizer. It was observed that PFOA strongly quenched the fluorescence emission of the MPA-CdS QDs because PFOA promotes the aggregation of MPA-CdS QDs through a fluorine–fluorine affinity interaction. Under optimum conditions, the fluorescence intensity of MPA-CdS QDs was observed to decrease linearly with an increase in the concentration of PFOA from 0.5 to 40 μmol L −1 , with a limit of detection of 0.3 μmol L −1 . This new method was successfully implemented for the analysis of PFOA-spiked textile samples, with recoveries ranging from 95% to 113%. - Highlights: • PFOA significantly quenched the fluorescence emission of quantum dots (QDs). • A rapid and simple fluorescence sensor was proposed for determining PFOA by QDs. • PFOA determination could be completed within approximately 10 min. • The developed method had a working range of 0.5 to 40 μmol L −1 and a detection limit of 0.3 μmol L −1

Determination of the effective radiative lifetimes of the 6 3P1 atomic mercury level in low-pressure mercury discharges

International Nuclear Information System (INIS)

van de Weijer, P.; Cremers, R.M.M.

1984-01-01

Experiments are described in which low-pressure mercury, mercury-argon and mercury-krypton discharges were irradiated with a dye laser pulse at 365.5 nm, thus exciting mercury atoms from the metastable 6 3 P 2 level to the 6 3 D 2 level. The 6 3 D 2 level decays radiatively to the 6 P levels. By recording the time dependence of the overpopulation in the 6 3 P 1 and the 6 1 P 1 level at the fluorescence signals at 254 nm and 185 nm, respectively, the effective radiative lifetime of these levels were determined. The effective radiative lifetime of the 6 3 P 1 level was measured in the k 0 R regime 0.1-500. The 6 1 P 1 lifetime was determined for the following discharge conditions: tube diameter 10-36 mm, mercury density 7.10 18 -2.10 21 m -3 , and noble gas pressure 0, 130, 400 Pa

Computer-assisted sperm morphometry fluorescence-based analysis has potential to determine progeny sex.

Science.gov (United States)

Santolaria, Pilar; Pauciullo, Alfredo; Silvestre, Miguel A; Vicente-Fiel, Sandra; Villanova, Leyre; Pinton, Alain; Viruel, Juan; Sales, Ester; Yániz, Jesús L

2016-01-01

This study was designed to determine the ability of computer-assisted sperm morphometry analysis (CASA-Morph) with fluorescence to discriminate between spermatozoa carrying different sex chromosomes from the nuclear morphometrics generated and different statistical procedures in the bovine species. The study was divided into two experiments. The first was to study the morphometric differences between X- and Y-chromosome-bearing spermatozoa (SX and SY, respectively). Spermatozoa from eight bulls were processed to assess simultaneously the sex chromosome by FISH and sperm morphometry by fluorescence-based CASA-Morph. SX cells were larger than SY cells on average (P potential to find differences between X- and Y-chromosome-bearing spermatozoa in bovine species although more studies are needed to increase the precision of sex determination by this technique.

Dye lasers in atomic spectroscopy

International Nuclear Information System (INIS)

Lange, W.; Luther, J.; Steudel, A.

1974-01-01

The properties of dye lasers which are relevant to atomic spectroscopy are discussed. Several experiments made possible by tunable dye lasers are discussed. Applications of high spectral density dye lasers are covered in areas such as absorption spectroscopy, fluorescence spectroscopy, photoionization and photodetachment, and two- and multi-photon processes. Applications which take advantage of the narrow bandwidth of tunable dye lasers are discussed, including saturation spectroscopy, fluorescence line narrowing, classic absorption and fluorescence spectroscopy, nonoptical detection of optical resonances, heterodyne spectroscopy, and nonlinear coherent resonant phenomena. (26 figures, 180 references) (U.S.)

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…

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

OpenAIRE

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

2011-01-01

Acesso restrito: Texto completo. In the present work a direct method for the determination of arsenic in petroleum derivatives has been developed, comparing the performance of a commercial transversely heated platform atomizer (THPA) with that of a transversely heated filter atomizer (THFA). The THFA results in a reduction of background absorption and an improved sensitivity as has been reported earlier for this atomizer. The mixture of 0.1% (m/v) Pd+0.03% (m/v) Mg+0.05% (v/v) Triton X-...

Simultaneous Laser-induced Fluorescence of Nitric Oxide and Atomic Oxygen in the Hypersonic Materials Environment Test System Arcjet Facility

Science.gov (United States)

Johansen, Craig; Lincoln, Daniel; Bathel, Brett; Inman, Jennifer; Danehy, Paul

2014-01-01

Simultaneous nitric oxide (NO) and atomic oxygen (O) laser induced fluorescence (LIF) experiments were performed in the Hypersonic Materials Environmental Test System (HYMETS) facility at the NASA Langley Research Center. The data serves as an experimental database for validation for chemical and thermal nonequilibrium models used in hypersonic flows. Measurements were taken over a wide range of stagnation enthalpies (6.7 - 18.5 MJ/kg) using an Earth atmosphere simulant with a composition of 75% N2, 20% O2, and 5% Ar (by volume). These are the first simultaneous measurements of NO and O LIF to be reported in literature for the HYMETS facility. The maximum O LIF mean signal intensity was observed at a stagnation enthalpy of approximately 12 MJ/kg while the maximum NO LIF mean signal intensity was observed at a stagnation enthalpy of 6.7 MJ/kg. Experimental results were compared to simple fluorescence model that assumes equilibrium conditions in the plenum and frozen chemistry in the isentropic nozzle expansion (Mach 5). The equilibrium calculations were performed using CANTERA v2.1.1 with 16 species. The fluorescence model captured the correlation in mean O and NO LIF signal intensities over the entire range of stagnation enthalpies tested. Very weak correlations between single-shot O and NO LIF intensities were observed in the experiments at all of the stagnation enthalpy conditions.

Atomically precise arrays of fluorescent silver clusters: a modular approach for metal cluster photonics on DNA nanostructures.

Science.gov (United States)

Copp, Stacy M; Schultz, Danielle E; Swasey, Steven; Gwinn, Elisabeth G

2015-03-24

The remarkable precision that DNA scaffolds provide for arraying nanoscale optical elements enables optical phenomena that arise from interactions of metal nanoparticles, dye molecules, and quantum dots placed at nanoscale separations. However, control of ensemble optical properties has been limited by the difficulty of achieving uniform particle sizes and shapes. Ligand-stabilized metal clusters offer a route to atomically precise arrays that combine desirable attributes of both metals and molecules. Exploiting the unique advantages of the cluster regime requires techniques to realize controlled nanoscale placement of select cluster structures. Here we show that atomically monodisperse arrays of fluorescent, DNA-stabilized silver clusters can be realized on a prototypical scaffold, a DNA nanotube, with attachment sites separated by <10 nm. Cluster attachment is mediated by designed DNA linkers that enable isolation of specific clusters prior to assembly on nanotubes and preserve cluster structure and spectral purity after assembly. The modularity of this approach generalizes to silver clusters of diverse sizes and DNA scaffolds of many types. Thus, these silver cluster nano-optical elements, which themselves have colors selected by their particular DNA templating oligomer, bring unique dimensions of control and flexibility to the rapidly expanding field of nano-optics.

Atomic spectroscopy and highly accurate measurement: determination of fundamental constants

International Nuclear Information System (INIS)

Schwob, C.

2006-12-01

This document reviews the theoretical and experimental achievements of the author concerning highly accurate atomic spectroscopy applied for the determination of fundamental constants. A pure optical frequency measurement of the 2S-12D 2-photon transitions in atomic hydrogen and deuterium has been performed. The experimental setting-up is described as well as the data analysis. Optimized values for the Rydberg constant and Lamb shifts have been deduced (R = 109737.31568516 (84) cm -1 ). An experiment devoted to the determination of the fine structure constant with an aimed relative uncertainty of 10 -9 began in 1999. This experiment is based on the fact that Bloch oscillations in a frequency chirped optical lattice are a powerful tool to transfer coherently many photon momenta to the atoms. We have used this method to measure accurately the ratio h/m(Rb). The measured value of the fine structure constant is α -1 = 137.03599884 (91) with a relative uncertainty of 6.7*10 -9 . The future and perspectives of this experiment are presented. This document presented before an academic board will allow his author to manage research work and particularly to tutor thesis students. (A.C.)

An Optical Characterization of Atomization in Non-Evaporating Diesel Sprays

OpenAIRE

Lockett, R. D.; Jeshani, M.; Makri, K.; Price, R.

2016-01-01

High-speed planar laser Mie scattering and Laser Induced Fluorescence (PLIF) was employed for the determination of Sauter Mean Diameter (SMD) distribution in non-evaporating diesel sprays. The effect of rail pressure, distillation profile, and consequent fuel viscosity on the drop size distribution developing during primary and secondary atomization was investigated. Samples of conventional crude-oil derived middle-distillate diesel and light distillate kerosene were delivered into an optical...

Study on fluorescence properties of carbogenic nanoparticles and their application for the determination of ferrous succinate

Energy Technology Data Exchange (ETDEWEB)

Sun Wen [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Du Yingxiang, E-mail: du_yingxiang@126.co [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Modern Chinese Medicines, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Wang Yunqing [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

2010-08-15

A new type of fluorescent nanomaterial named carbogenic nanoparticles (NPs) has drawn considerable attention recently. In this study, we adopted a direct and simple synthetic method to produce the carbogenic NPs and investigated the fluorescence properties of the as-prepared carbogenic NPs in detail. It was found that the fluorescence of carbogenic NPs was stable with the variance of environmental conditions such as pH, temperature and UV irradiation. More interestingly, we found carbogenic NPs exhibited high selectivity and sensitivity towards ferric ions. Under optimum conditions, a good linear relationship could be obtained between the fluorescence intensity and concentration of ferric ions in the range of 5.0x10{sup -5}-5.0x10{sup -4} mol L{sup -1}, and the limit of detection is 11.2 {mu}mol L{sup -1}. Based on the fluorescence quenching of carbogenic NPs, a rapid and specific quantitative method was proposed for the determination of ferrous succinate. The content of ferrous succinate in commercial tablets determined by the present method was agreed with the spectrophotometric method results and the reproducibility and the recovery of the proposed method were satisfactory.

Locations of oxygen, nitrogen and carbon atoms in vanadium determined by neutron diffraction

International Nuclear Information System (INIS)

Hiraga, K.; Onozuka, T.; Hirabayashi, M.

1977-01-01

The occupation sites of oxygen, nitrogen, and carbon atoms dissolved interstitially in vanadium have been determined by means of neutron diffraction with use of single crystals of VOsub(0.032), VNsub(0.013) and VCsub(0.006). It is revealed that the interstitial atoms occupy, randomly, the octahedral sites in the b.c.c. host lattice of the three crystals. Neutron diffraction is advantageous for the present purpose, since the coherent scattering amplitudes of the solute atoms are much larger than that of the vanadium atom. (Auth.)

Quantitative Determination of Arsenic in Bottled Drinking Water Using Atomic Absorption Spectroscopy

Directory of Open Access Journals (Sweden)

Maria Guţu Claudia

2013-10-01

Full Text Available Background: Many studies have been performed in the past few years, to determine arsenic speciation in drinking water, food chain and environment, arsenic being a well-recognized carcinogenic and toxic agent mainly in its inorganic species. The instrumental techniques used for arsenic determination, such as hydride generation atomic absorption spectrometry (HGAAS, graphite furnace atomic absorption spectrometry (GFAAS and inductively coupled plasma mass spectrometry (ICP-MS, can provide a great sensitivity only on the total amount. Objective: The aim of this study was to develop a simple and rapid method and to analyze the concentration of total inorganic arsenic in bottled drinking water. Methods: Total arsenic was determined in samples from six different types of commercially available bottled drinking water using atomic absorption spectrometry with electrothermal or hydride generation vaporisation. All drinking water samples were acidified with 0.1M nitric acid to match the acidity of the standards. Results: The method was linear within the studied range (1-5 μg/L, R = 0.9943. The quantification limits for arsenic determination were 0.48 μg/L (HGAAS and 0.03 μg/L (GFAAS. The evaluated arsenic content in drinking water was within the accepted limits provided by law. Conclusions: A simple and sensitive method for the quantification of arsenic in drinking water using atomic absorbtion spectroscopy was described, which can be further used in toxicological studies. As an additional advantage, the system is very fast, efficient and environmental friendly

Determination of the activity of telomerase in cancer cells by using BSA-protected gold nanoclusters as a fluorescent probe.

Science.gov (United States)

Xu, Yujuan; Zhang, Peng; Wang, Zhen; Lv, Shaoping; Ding, Caifeng

2018-02-27

Gold nanoclusters (AuNCs) protected with a bovine serum albumin (BSA) coating are known to emit red fluorescence (peaking at 650 nm) on photoexcitation with ultraviolet light (365 nm). On addition of Cu(II) ions, fluorescence is quenched because Cu(II) complexes certain amino acid units in the BSA chain. Fluorescence is, however, restored if pyrophosphate (PPi) is added because it will chelate Cu(II) and remove it from the BSA coating on the AuNCs. Because PPi is involved in the function of telomerase, the BSA@AuNCs loaded with Cu(II) can act as a fluorescent probe for determination of the activity of telomerase. A fluorescent assay was worked out for telomerase that is highly sensitive and has a wide linear range (10 nU to 10 fM per mL). The fluorescent probe was applied to the determination of telomerase activity in cervix carcinoma cells via imaging. It is shown that tumor cells can be well distinguished from normal cells by monitoring the differences in intracellular telomerase activity. Graphical abstract Gold nanoclusters (AuNCs) protected by bovine serum albumin (BSA) and displaying red photoluminescence were prepared as fluorescent probe for the determination of telomerase activity and used for imaging of cervix carcinoma (HeLa) cells.

Determination of Fe and Zn in healing plants by radionuclide X-ray fluorescence analysis

International Nuclear Information System (INIS)

Harangozo, M.; Toelgyessy, J.; Tomecek, O.; Ruzicka, I.; Cejpek, K.

1999-01-01

Radionuclide X-ray fluorescence method was used for the determination of Fe and Zn in healing plants (Sage, Peppermint, Stinging, Common Agrimony, Milfoil, Ribwort, Tansy, White Dead-Nettle). 238 Pu exciting source and Si/Li semiconductor detector were used for the determination. (author)

Development of inductively coupled plasma atomic emission spectrometry for palladium and Rhodium determination in platinum-based alloy

International Nuclear Information System (INIS)

Kovacevic, R.; Todorovic, M.; Manojlovic, D.; Mutic, J.

2008-01-01

Inductively coupled plasma atomic emission spectroscopy with internal standardization was applied for the analysis of an in-house reference platinum alloy containing palladium and rhodium (approximately 5% by weight). In order to compensate for variations in signal recovery due to matrix interferences, and therefore to improve the precision, platinum. the major component, was chosen as an internal standard. Quantitative analysis was based on calibration using a set of matrix-matched calibration standards with and without employing the internal standard. These results were compared with those obtained by X-ray fluorescence spectroscopy. The results for both techniques were in a good agreement, although the precision was slightly better in the inductively coupled plasma atomic emission spectroscopy technique, with or without the internal standard

The application of atomic absorption spectrometry to chemical analysis

International Nuclear Information System (INIS)

Walsh, A.

1980-01-01

YhThe history of the development of atomic absorption methods of elemental analysis is outlined. The theoretical basis of atomic absorption methods is discussed and the principle of modern methods of atomic absorption measurements is described. The advantages, scope and limations of these methods are discussed. Related methods based on the measurement of atomic fluorescence are also described

[Sensitive Determination of Chondroitin Sulfate by Fluorescence Recovery of an Anionic Aluminum Phthalocyanine-Cationic Surfactant Ion-Association Complex Used as a Fluorescent Probe Emitting at Red Region].

Science.gov (United States)

Chen, Lin; Huang, Ping; Yang, Hui-qing; Deng, Ya-bin; Guo, Meng-lin; Li, Dong-hui

2015-08-01

Determination of chondroitin sulfate in the biomedical field has an important value. The conventional methods for the assay of chondroitin sulfate are still unsatisfactory in sensitivity, selectivity or simplicity. This work aimed at developing a novel method for sensitive and selective determination of chondroitin sulfate by fluorimetry. We found that some kinds of cationic surfactants have the ability to quench the fluorescence of tetrasulfonated aluminum phthalocyanine (AlS4Pc), a strongly fluorescent compound which emits at red region, with high efficiency. But, the fluorescence of the above-mentioned fluorescence quenching system recovered significantly when chondroitin sulfate (CS) exits. Tetradecyl dimethyl benzyl ammonium chloride(TDBAC) which was screened from all of the candidates of cationic surfactants was chosen as the quencher because it shows the most efficient quenching effect. It was found that the fluorescence of AlS4Pc was extremely quenched by TDBAC because of the formation of association complex between AlS4Pc and TDBAC. Fluorescence of the association complex recovered dramatically after the addition of chondroitin sulfate (CS) due to the ability of chondroitin sulfate to shift the association equilibrium of the association, leading to the release of AlS4Pc, thus resulting in an increase in the fluorescence of the reaction system. Based on this phenomenon, a novel method with simplicity, accuracy and sensitivity was developed for quantitative determination of CS. Factors including the reaction time, influencing factors and the effect of coexisting substances were investigated and discussed. Under optimum conditions the linear range of the calibration curve was 0.20~10.0 μg · mL(-1). The detection limit for CS was 0.070 μg · mL(-1). The method has been applied to the analysis of practical samples with satisfied results. This work expands the applications of AlS4Pc in biomedical area.

Division of Atomic Physics. Lund Institute of Technology. Progress Report 1993-1994

International Nuclear Information System (INIS)

Wahlstroem, C.G.

1995-01-01

The Division of Atomic Physics is responsible for basic physics teaching in all engineering disciplines and for specialized teaching in Optics, Atomic Physics, Spectroscopy, Laser Physics, and Non-Linear Optics. Research activities are mainly carried out in the fields of basic and applied spectroscopy, largely based on the use of lasers. Projects in the following areas are reported: Basic Atomic Physics - Atomic physics with high power laser radiation; Laser spectroscopic investigations of atomic and ionic excited states in the short-wavelength region; Laser spectroscopy in the visible; Theoretical Atomic Physics; Applied Optics and Quantum Electronics -High resolution spectroscopy; Photon echoes in Rare Earth Ion Doped Crystals; diode laser Spectroscopy; Environmental Remote Sensing -Tropospheric Ozone Lidar; Measurement of gases of geophysical origin; Industrial and Urban Pollution Measurements; Laser induced fluorescence of vegetation and water; Applications in Medicine and Biology - Tissue diagnostic using Laser-induced fluorescence; Photodynamic Therapy; Measurement of Optical Properties of Tissue with applications to Diagnostics; Two Photon Excited fluorescence Microscopy; Capillary Electrophoresis; New Techniques; Industrial Applications - Optical spectroscopy in Metallurgy; Physics of Electric Breakdown in Dielectric liquids; Optical Spectroscopy of Paper

Division of Atomic Physics. Lund Institute of Technology. Progress Report 1993-1994

Energy Technology Data Exchange (ETDEWEB)

Wahlstroem, C.G. [ed.

1995-12-31

The Division of Atomic Physics is responsible for basic physics teaching in all engineering disciplines and for specialized teaching in Optics, Atomic Physics, Spectroscopy, Laser Physics, and Non-Linear Optics. Research activities are mainly carried out in the fields of basic and applied spectroscopy, largely based on the use of lasers. Projects in the following areas are reported: Basic Atomic Physics - Atomic physics with high power laser radiation; Laser spectroscopic investigations of atomic and ionic excited states in the short-wavelength region; Laser spectroscopy in the visible; Theoretical Atomic Physics; Applied Optics and Quantum Electronics -High resolution spectroscopy; Photon echoes in Rare Earth Ion Doped Crystals; diode laser Spectroscopy; Environmental Remote Sensing -Tropospheric Ozone Lidar; Measurement of gases of geophysical origin; Industrial and Urban Pollution Measurements; Laser induced fluorescence of vegetation and water; Applications in Medicine and Biology - Tissue diagnostic using Laser-induced fluorescence; Photodynamic Therapy; Measurement of Optical Properties of Tissue with applications to Diagnostics; Two Photon Excited fluorescence Microscopy; Capillary Electrophoresis; New Techniques; Industrial Applications - Optical spectroscopy in Metallurgy; Physics of Electric Breakdown in Dielectric liquids; Optical Spectroscopy of Paper.

Division of Atomic Physics. Lund Institute of Technology. Progress Report 1993-1994

Energy Technology Data Exchange (ETDEWEB)

Wahlstroem, C G [ed.

1996-12-31

The Division of Atomic Physics is responsible for basic physics teaching in all engineering disciplines and for specialized teaching in Optics, Atomic Physics, Spectroscopy, Laser Physics, and Non-Linear Optics. Research activities are mainly carried out in the fields of basic and applied spectroscopy, largely based on the use of lasers. Projects in the following areas are reported: Basic Atomic Physics - Atomic physics with high power laser radiation; Laser spectroscopic investigations of atomic and ionic excited states in the short-wavelength region; Laser spectroscopy in the visible; Theoretical Atomic Physics; Applied Optics and Quantum Electronics -High resolution spectroscopy; Photon echoes in Rare Earth Ion Doped Crystals; diode laser Spectroscopy; Environmental Remote Sensing -Tropospheric Ozone Lidar; Measurement of gases of geophysical origin; Industrial and Urban Pollution Measurements; Laser induced fluorescence of vegetation and water; Applications in Medicine and Biology - Tissue diagnostic using Laser-induced fluorescence; Photodynamic Therapy; Measurement of Optical Properties of Tissue with applications to Diagnostics; Two Photon Excited fluorescence Microscopy; Capillary Electrophoresis; New Techniques; Industrial Applications - Optical spectroscopy in Metallurgy; Physics of Electric Breakdown in Dielectric liquids; Optical Spectroscopy of Paper.

Determination of the dispersion coefficient, in rivers through radioactive and fluorescent tracers

International Nuclear Information System (INIS)

Almeida Rosso, T.C. de.

1986-03-01

The purpose of this work was to determine experimentally the dispersion coefficient in natural streams through the aplication of radioactive and fluorescent tracers. The technique used to obtain the experimental data was the simmultaneous injection of the radioactive tracer Bromim - 82 and the fluorescent ones, Amidorodamine G. extra and Uranine. A comparison among these different tracers is shown as well as the performance of Uranine in a poluented stream in the presence of suspended sediments. The site chosen for the experiments was the Piabanha River, between Pedro do Rio and Areal, located at Rio de Janeiro state, in a nearly 20 Km strech. (Author) [pt

The determination, by atomic-absorption spectrophotometry using electrothermal atomization, of platinum, palladium, rhodium, ruthenium, and iridium

International Nuclear Information System (INIS)

Haines, J.; Robert, R.V.D.

1982-01-01

A method that involves measurement by atomic-absorption spectrophotometry using electrothermal atomization has been developed for the determination of trace quantities of platinum, palladium, rhodium, ruthenium, and iridium in mineralogical samples. The elements are separated and concentrated by fusion, nickel sulphide being used as the collector, and the analyte elements are measured in the resulting acid solution. An organic extraction procedure was found to offer no advantages over the proposed method. Mutual interferences between the five platinum-group metals examined, as well as interferences from gold, silver, and nickel were determined. The accuracy of the measurement was established by the analysis of a platinum-ore reference material. The lower limits of determination of each of the analyte elements in a sample material are as follows: platinum 1,6μg/l, palladium 0,2μg/1, rhodium 0,5μg/l, ruthenium 3μg/l, and iridium 2,5μg/l. The relative standard deviations range from 0,05 for rhodium to 0.08 for iridium. The method, which is described in detail in the Appendix, is applicable to the determination of these elements in ores, tailings, and geological materials in which the total concentration of the noble metals is less than 1g/t

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.

X-ray holography. Atoms in three dimensions

International Nuclear Information System (INIS)

Tegze, M.

2005-01-01

The principles of atomic resolution X-ray holography was elaborated in 1991. X-ray photons scatter thousand times less on atoms than electrons of the same wavelength. As a result, both free path and penetration depth are higher which giver information about the bulk material. X-ray holography is realized by irradiating the single crystal sample with radiation from external X-ray source. The incident radiation is ionizing the atoms of the sample to emit fluorescent radiation. The angle dependence of the fluorescent radiation results an image containing the hologram. The hologram itself is extremely small compared to the background that needs 10 10 capturing photons to recover image. Using Thomas Gog's method and synchrotron radiation the X-ray holography becomes more usable, but the method still needs refining both experimentally and theoretically. (TRA)

Rapid extraction and x-ray fluorescence determination of gold in rock

International Nuclear Information System (INIS)

Lobanov, F.I.; Logunova, S.A.; Popov, A.M.; Krasnopevtseva, E.V.

1994-01-01

The optimal conditions for gold extractional recovery by melts of aliphatic monocarboxylic acids mixtures (C ≥ 16) with additions of di-2-ethylhexyldithiophosphoric acid, di-n-oxtylsulfide and alkylaniline were determined. A rapid method of extraction and X-ray fluorescence detection of gold in the presence of considerable amounts of Fe, Cu, Pb, Cd, Zn and Bi was developed

Rapid fluorometric determination of perfluorooctanoic acid by its quenching effect on the fluorescence of quantum dots

Energy Technology Data Exchange (ETDEWEB)

Liu, Qi; Huang, Aizhen; Wang, Nan, E-mail: nwang@hust.edu.cn; Zheng, Guan; Zhu, Lihua

2015-05-15

Analysis of perfluorooctanoic acid (PFOA) usually requires a combination of high-performance liquid chromatography and mass spectrometry, which is expensive and time-consuming. In the present work, water-soluble CdS quantum dots (QDs) were employed to develop a simple and rapid fluorometric method for the determination of PFOA. Strongly fluorescent CdS QDs were prepared by using 3-mercaptopropionic acid (MPA) as a stabilizer. It was observed that PFOA strongly quenched the fluorescence emission of the MPA-CdS QDs because PFOA promotes the aggregation of MPA-CdS QDs through a fluorine–fluorine affinity interaction. Under optimum conditions, the fluorescence intensity of MPA-CdS QDs was observed to decrease linearly with an increase in the concentration of PFOA from 0.5 to 40 μmol L{sup −1}, with a limit of detection of 0.3 μmol L{sup −1}. This new method was successfully implemented for the analysis of PFOA-spiked textile samples, with recoveries ranging from 95% to 113%. - Highlights: • PFOA significantly quenched the fluorescence emission of quantum dots (QDs). • A rapid and simple fluorescence sensor was proposed for determining PFOA by QDs. • PFOA determination could be completed within approximately 10 min. • The developed method had a working range of 0.5 to 40 μmol L{sup −1} and a detection limit of 0.3 μmol L{sup −1}.

Cu,Cr and As determination in preserved woods (Eucalyptus ssp.) by X-ray fluorescence spectrometries; Determinacao de cobre, cromo e arsenio em madeira preservada (Eucalyptus sp.) pelas espectrometrias de fluorescencia de raios X

Energy Technology Data Exchange (ETDEWEB)

Pereira Junior, Sergio Matias

2014-07-01

Brazil produces around 2.2 millions of cubic meters of treated wood to meet the annual demand of railway, electric, rural and construction sectors. The most used wood species are eucalyptus (Eucalyptus ssp.) and pine (Pinus ssp.).The treated woods used for poles, sleepers, fence posts and plywoods should be according to Brazilian norms requirements. The most usual wood preservative products used in Brazil are CCA (chromated copper arsenate) and CCB (copper chromium and boron salt). The analytical methods, such as flame atomic absorption spectrometry (FAAS), plasma inductively coupled optical emission spectrometry (ICPOES) and X-ray fluorescence spectrometry (XRFS) have been used for the analytical control of those treatment processes. In this work, the eucalyptus trees (Eucalyptus ssp) samples was obtained from Minas Gerais State, Brazil, cut plantation areas. Under pressure, eucalyptus wood samples were submitted to different concentration of CCA solution reaching 3.9, 6.7, 9.1, 12.4 and 14.0 kg of CCA by m-³ sapwood retentions. Samples in cylinders and sawdust forms were obtained from treated wood samples. Copper, chromium and arsenic determination was performed using the energy dispersive X-ray fluorescence spectrometry (EDXRFS), portable X-ray fluorescence spectrometry (PXRFS), flame atomic absorption spectrometry (FAAS) and instrumental neutron activation analysis. In this work, the method of analysis, sensitivity, precision and accuracy performances of the related techniques were outlined. (author)

High sensitive determination of zinc with novel water-soluble small molecular fluorescent sensor

International Nuclear Information System (INIS)

Weng Ying; Chen Zilin; Wang Fang; Xue Lin; Jiang Hua

2009-01-01

A high sensitive method of quantitative analysis for the determination of zinc in the nutrition supplements has been developed by using a novel water-soluble fluorescent sensor HQ3: (8-pyridylmethyloxy-2-methyl-quinoline). Under the optimized condition of 67 mM phosphate buffer, pH 7.4, and 5% (v/v) DMSO, the zinc concentration showed good linear relationship with fluorescence intensity in the range of 7.5 x 10 -8 to 2.5 x 10 -5 M with the detection limit of 1.5 x 10 -8 M. HQ3 exhibited high selectivity to zinc comparing with other metal ions except for cadmium. The developed analytical method was successfully used for determining the content of zinc in a real sample of zinc gluconate solution of Sanchine.

[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.

Local mobility in lipid domains of supported bilayers characterized by atomic force microscopy and fluorescence correlation spectroscopy.

Energy Technology Data Exchange (ETDEWEB)

Frankel, Daniel J.; Buranda, T. (University of New Mexico, Albuquerque, NM); Burns, Alan Richard

2005-01-01

Fluorescence correlation spectroscopy (FCS) is used to examine mobility of labeled probes at specific sites in supported bilayers consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid domains in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). Those sites are mapped beforehand with simultaneous atomic force microscopy and submicron confocal fluorescence imaging, allowing characterization of probe partitioning between gel DPPC and disordered liquid DOPC domains with corresponding topography of domain structure. We thus examine the relative partitioning and mobility in gel and disordered liquid phases for headgroup- and tailgroup-labeled GM1 ganglioside probes and for headgroup- and tailgroup-labeled phospholipid probes. For the GM1 probes, large differences in mobility between fluid and gel domains are observed; whereas unexpected mobility is observed in submicron gel domains for the phospholipid probes. We attribute the latter to domain heterogeneities that could be induced by the probe. Furthermore, fits to the FCS data for the phospholipid probes in the DOPC fluid phase require two components (fast and slow). Although proximity to the glass substrate may be a factor, local distortion of the probe by the fluorophore could also be important. Overall, we observe nonideal aspects of phospholipid probe mobility and partitioning that may not be restricted to supported bilayers.

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, ...

Determination of rare-earth elements in rocks by isotope-excited X-ray fluorescence spectrometry

DEFF Research Database (Denmark)

Kunzendorf, Helmar; Wollenberg, H.A.

1970-01-01

Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated ......-ray spectrometric scan of a longitudinally sliced drill core showed a close correlation between rare-earth abundances and appropriate minerals.......Isotope-excited X-ray fluorescence spectrometry furnishes a rapid determination of rare-earth elements in unprepared rock samples. The samples are excited by 241Am γ-rays, generating X-ray spectra on a multichannel pulse-height analyser. Gaussian peaks of the Kα and Kβ X-ray energies are treated...

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.

Experimental station for gas phase fluorescence spectroscopy

International Nuclear Information System (INIS)

Stankiewicz, M.; Garcia, E. Melero; Ruiz, J. Alvarez; Erman, P.; Hatherly, P.A.; Kivimaeki, A.; Rachlew, E.; Rius i Riu, J.

2004-01-01

The details of an experimental setup for gas phase atomic and molecular fluorescence measurements using synchrotron radiation are described in this article. The most significant part of the apparatus is an optical arrangement, which allows for simultaneous measurements of dispersed as well as total fluorescence intensity using an effusive gas jet and an inbuilt gas cell assembled in a convenient plug and measure configuration. The first measurements concerning fluorescence of the N 2 molecule around the N 1s edge obtained with this setup are presented

Achieving 100% Efficient Postcolumn Hydride Generation for As Speciation Analysis by Atomic Fluorescence Spectrometry.

Science.gov (United States)

Marschner, Karel; Musil, Stanislav; Dědina, Jiří

2016-04-05

An experimental setup consisting of a flow injection hydride generator coupled to an atomic fluorescence spectrometer was optimized in order to generate arsanes from tri- and pentavalent inorganic arsenic species (iAs(III), iAs(V)), monomethylarsonic acid (MAs(V)), and dimethylarsinic acid (DMAs(V)) with 100% efficiency with the use of only HCl and NaBH4 as the reagents. The optimal concentration of HCl was 2 mol L(-1); the optimal concentration of NaBH4 was 2.5% (m/v), and the volume of the reaction coil was 8.9 mL. To prevent excessive signal noise due to fluctuations of hydride supply to an atomizer, a new design of a gas-liquid separator was implemented. The optimized experimental setup was subsequently interfaced to HPLC and employed for speciation analysis of arsenic. Two chromatography columns were tested: (i) ion-pair chromatography and (ii) ion exchange chromatography. The latter offered much better results for human urine samples without a need for sample dilution. Due to the equal hydride generation efficiency (and thus the sensitivities) of all As species, a single species standardization by DMAs(V) standard was feasible. The limits of detection for iAs(III), iAs(V), MAs(V), and DMAs(V) were 40, 97, 57, and 55 pg mL(-1), respectively. Accuracy of the method was tested by the analysis of the standard reference material (human urine NIST 2669), and the method was also verified by the comparative analyses of human urine samples collected from five individuals with an independent reference method.

Electron beam induced fluorescence measurements of the degree of hydrogen dissociation in hydrogen plasmas

NARCIS (Netherlands)

Smit, C.; Brussaard, G.J.H.; de Beer, E.C.M.; Schram, D.C.; Sanden, van de M.C.M.

2004-01-01

The degree of dissociation of hydrogen in a hydrogen plasma has been measured using electron beam induced fluorescence. A 20 kV, 1 mA electron beam excites both the ground state H atom and H2 molecule into atomic hydrogen in an excited state. From the resulting fluorescence the degree of

The determination, by atomic-absorption spectrophotometry, of impurities in manganese dioxide

International Nuclear Information System (INIS)

Balaes, G.E.E.; Robert, R.V.D.

1981-01-01

This report describes various methods for the determination of impurities in electrolytic manganese dioxide by atomic-absorption spectrophotometry (AAS). The sample is dissolved in a mixture of acids, any residue being ignited and retreated with acid. Several AAS methods were applied so that the analysis required to meet the specifications could be attained. These involved conventional flame AAS, AAS with electrothermal atomization (ETA), hydride generation coupled with AAS, and cold-vapour AAS. Of the elements examined, copper, iron, zinc, and lead can be determined direct with confidence with or without corrections based on recoveries obtained from spiked solutions. Nickel can be determined direct by use of the method of standard additions, and copper, nickel, and lead by ETA with the method of standard additions. Arsenic and antimony are determined by hydride generation coupled with AAS, and mercury by cold-vapour AAS. The precision of analysis (relative standard deviation) is generally less than 0,050. Values were obtained for aluminium, molybdenum, magnesium, sodium, copper, chromium, and cadmium, but the accuracy of these determinations has not been fully established

The method of intersecting spheres for determination of coordination numbers of atoms in crystal structures

International Nuclear Information System (INIS)

Serezhkin, V.N.; Buslaev, Yu.A.; Mikhajlov, Yu.N.

1997-01-01

New method for determination of coordination numbers (CN) of atoms in crystal structures, based on the model of interatomic interaction, within the frames whereof each atom is approximated by two spheres with the common center in the atom nuclei, is proposed. One of the spheres specifies conditionally isolated (chemically unbound) atom and its radius is a constant, which for atoms of the given chemical sort in the structure of any compound is equal to quasi-orbital Sleiter radius. The sphere of the other radius specifies chemically bound atom and coincides with the sphere, the volume whereof is equal to the volume of the Voronoj-Dirichlet polyhedron of the corresponding atom in the structure of the concrete crystal. Using a series of examples, workability of the given method for CN determination of atoms in structures of both simple substances and chemical compounds (alkali, transition metals, U, Th). Good agreement of the obtained results with the generally accepted CN s of atoms for the considered crystals is noted and a number of principal advantages of the new method, as compared to classical one of the CNs evaluation, is demonstrated

Mercury speciation in thawed out and refrozen fish samples by gas chromatography coupled to inductively coupled plasma mass spectrometry and atomic fluorescence spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Krystek, Petra; Ritsema, Rob [National Institute for Public Health and the Environment (RIVM), Laboratory for Analytical Chemistry, Bilthoven (Netherlands)

2005-01-01

Different sub-sampling procedures were applied for the determination of mercury species (as total mercury Hg, methylmercury MeHg{sup +} and inorganic mercury Hg{sup 2+}) in frozen fish meat. Analyses were carried out by two different techniques. After the sample material was pre-treated by microwave digestion, atomic fluorescence spectroscopy (AFS) was used for the determination of total Hg. Speciation analysis was performed according to the following procedure: dissolution of sample material in tetramethylammonium hydroxide (TMAH), derivatisation with sodium tetraethylborate (NaBEt{sub 4}), extraction into isooctane and measurement with gas chromatography inductively coupled plasma mass spectrometry (GC-ICPMS) for the identification and quantification of methylmercury (MeHg{sup +}) and inorganic mercury (Hg{sup 2+}). The concentration range of total Hg measured in the shark fillets is between 0.9 and 3.6 {mu}g g{sup -1} thawed out shark fillet. Speciation analysis leads to {>=}94% Hg present as MeHg{sup +}. Homogeneity, storage conditions and stability of analytical species and sample materials have great influence on analytical results. Sub-sampling of half-frozen/partly thawed out fish and analysis lead to significantly different concentrations, which are on average a factor of two lower. (orig.)

Determination of trace aluminum by fluorescence quenching method based on catalysis of potassium chlorate oxidizing alizarin red

Science.gov (United States)

Shao-Qin, Lin; Xuan, Lin; Shi-Rong, Hu; Li-Qing, Zeng; Yan, Wang; Li, Chen; Jia-Ming, Liu; Long-Di, Li

2005-11-01

A new method for the determination of trace aluminum has been proposed. It is based on the fact that alizarin red can emit strong and stable fluorescence at 80 °C for 30 min and Al 3+ can effectively catalyze potassium chlorate oxidizing alizarin red to form non-fluorescence complex which cause the fluorescence quenching. The linear dynamic range of this method is 0.040-4.00 ng l -1 with a detection limit of 5.3 pg l -1. The regression equation can be expressed as Δ If = 8.731 + 21.73 c (ng l -1), with the correlation coefficient r = 0.9992 ( n = 6). This sensitive, rapid and accurate method has been applied to the determination of trace aluminum(III) in human hair and tea samples successfully. What is more, the mechanism of catalyzing potassium chlorate oxidizing alizarin red by the fluorescence quenching method is also discussed.

Optically trapped atomic resonant devices for narrow linewidth spectral imaging

Science.gov (United States)

Qian, Lipeng

This thesis focuses on the development of atomic resonant devices for spectroscopic applications. The primary emphasis is on the imaging properties of optically thick atomic resonant fluorescent filters and their applications. In addition, this thesis presents a new concept for producing very narrow linewidth light as from an atomic vapor lamp pumped by a nanosecond pulse system. This research was motivated by application for missile warning system, and presents an innovative approach to a wide angle, ultra narrow linewidth imaging filter using a potassium vapor cell. The approach is to image onto and collect the fluorescent photons emitted from the surface of an optically thick potassium vapor cell, generating a 2 GHz pass-band imaging filter. This linewidth is narrow enough to fall within a Fraunhefer dark zone in the solar spectrum, thus make the detection solar blind. Experiments are conducted to measure the absorption line shape of the potassium resonant filter, the quantum efficiency of the fluorescent behavior, and the resolution of the fluorescent image. Fluorescent images with different spatial frequency components are analyzed by using a discrete Fourier transform, and the imaging capability of the fluorescent filter is described by its Modulation Transfer Function. For the detection of radiation that is spectrally broader than the linewidth of the potassium imaging filter, the fluorescent image is seen to be blurred by diffuse fluorescence from the slightly off resonant photons. To correct this, an ultra-thin potassium imaging filter is developed and characterized. The imaging property of the ultra-thin potassium imaging cell is tested with a potassium seeded flame, yielding a resolution image of ˜ 20 lines per mm. The physics behind the atomic resonant fluorescent filter is radiation trapping. The diffusion process of the resonant photons trapped in the atomic vapor is theoretically described in this thesis. A Monte Carlo method is used to simulate the

Development of atomic spectroscopy technology

International Nuclear Information System (INIS)

Lee, Jong Min; Cha, Hyung Ki; Song, Kyu Seok; Yang, Ki Ho; Baik, Dae Hyun; Lee, Young Joo; Yi, Jong Hoon; Jeong, Do Young; Jeong, Eui Chang; Yoo, Byung Duk; Cha, Byung Heon; Kim, Seong Ho; Nam, Seong Mo; Kim, Sun Kuk; Lee, Byung Cheol; Choi, Hwa Lim; Ko, Dok Yung; Han, Jae Min; Rho, Si Pyo; Lim, Chang Hwan; Choi, An Seong

1992-12-01

This project is aimed for the 'Development of extraction and separation techniques for stable isotopes by atomic laser spectroscopy technique'. The project is devided by two sub-projects. One is the 'Development of the selective photoionization technology' and the other is 'Development of ultrasensitive spectroscopic analysis technololgy'. This year studies on Hg and Yb, both of which have 7 isotopes, have been performed and, as a result, it was proved that specific isotopes of these elements could be selectively extracted. In addition study on plasma extraction technique, development of atomizers, design of electron gun have been the result of the project in 1992. In second sub-project trace determination of Pb has been performed with laser resonance ionization spectroscopy. As a result 20 picogram of detection limit has been obtained. In addition to these results, design of high sensitive laser induced fluorescence detection system as well as remote sensing DIAL system have been done. (Author)

Determination of selenium via the fluorescence quenching effect of selenium on hemoglobin-catalyzed peroxidative reaction.

Science.gov (United States)

Chen, Ya-Hong; Zhang, Ya-Nan; Tian, Feng-Shou

2015-05-01

A new method for the determination of selenium based on its fluorescence quenching on the hemoglobin-catalyzed reaction of H2 O2 and l-tyrosine has been established. The effect of pH, foreign ions and the optimization of variables on the determination of selenium was examined. The calibration curve was found to be linear between the fluorescence quenching (F0 /F) and the concentration of selenium within the range of 0.16-4.00 µg/mL. The detection limit was 1.96 ng/mL and the relative standard deviation was 3.14%. This method can be used for the determination of selenium in Se-enriched garlic bulbs with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd.

Heavy element concentration determination by the x-ray fluorescence analysis using radioisotope {gamma}-ray sources; Dosage d'elements lourds par fluorescence X utilisant des radio-sources de rayons gamma

Energy Technology Data Exchange (ETDEWEB)

Enomoto, S [Commissariat a l' Energie Atomique, Dir. des Materiaux et des Combustibles Nucleaires, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

A theoretical and experimental study has been made on the fluorescence analysis of high atomic number element, using {gamma}-ray sources for excitation and characteristic K X-rays for the measurement. The choice of the proper {gamma}-ray energy according to the conditions of the determination is considered. The author has studied the usefulness of using the backscattered {gamma}-rays as a correction mean for matrix and grain-size effects. Sources of {sup 153}Gd, {sup 57}Co, {sup 137}Cs have been used for excitation using collimated geometries. Concentration measurements of tungsten in steel, tungsten and lead in aqueous solution, PbS in SiO{sub 2}-PbS powder mixtures have been done, as well as thickness evaluation of gold layers on copper. A precision of about 0.2 per cent (abs.) is obtained for lead determination in light matrixes. A probe design is proposed for the continuous determination of lead in aqueous solutions. (author) [French] On etudie de maniere theorique et experimentale l'analyse d'elements a nombre atomique eleve par fluorescence en utilisant des sources de rayons {gamma} pour l'excitation, et des rayons-X K caracteristiques pour la mesure. On considere le choix de l'energie appropriee des rayons {gamma} suivant les conditions experimentales. L'utilite d'employer les rayons {gamma} retrodiffuses pour corriger les effets de la matrice et de la dimension des grains est etudiee. Des sources de {sup 153}Gd, de {sup 57}Co et de {sup 137}Cs a geometrie collimatee ont ete utilisees pour l'excitation. Des mesures de la concentration du tungstene dans l'acier, du tungstene et du plomb en solutions aqueuses, et du PbS dans des melanges de poudre SiO{sub 2}-PbS ont ete entreprises ainsi que l'evaluation de l'epaisseur des couches d'or sur le cuivre. On obtient une precision d'environ 0,2 pour cent (en absolu) pour la determination du plomb dans des matrices legeres. On propose un modele de sonde pour la determination en continu du plomb en solution aqueuse

Determination of Europium by fluorescence using pyrrolidinium based task specific ionic liquid

International Nuclear Information System (INIS)

Kumar, Satendra; Gayan, Siuli Maji; Sankaran, K.

2012-01-01

Determination of lanthanides using fluorescence is a major challenge in aqueous medium due to their poor molar absorptivities and low quantum yield. To overcome these problems, ligand sensitized fluorescence has been widely used for trace level detection of lanthanides in solutions. Recently, ionic liquid a non aqueous medium has been used to observe the fluorescence of lanthanides. In this work we have used pyrrolidinium based ionic liquid for the study of europium fluorescence. The ionic liquid (bmpyr)(BA) was prepared using the metathesis reaction involving 1-butyl,1-methyl pyrrolidinium chloride (bmpyr)(CI). (bmpyr)(Cl) crystals and silver benzoate were added according to their mole equivalents in methanol and stirred for 4 hrs. The filtrate was concentrated using a rotary evaporator, dried for 10 h at room temperature, and then for 40 h at 105℃under reduced pressure. This results in a white crystalline hygroscopic solid which was characterized by FT-lR spectroscopy. The yield of the product was ∼ 95%. Butyl-1, methyl pyrrolidinium bis(trifluoromethanesulfonyl)amide (bmpyr)(TF 2 N) is used for dissolve and dilute (bmpyr)(BA) and fluorescence and life time of Eu 3+ were obtained. For the concentration of Eu 3+ used in this study (2x10 -7 M), the optimum concentration of the sensitizing ionic liquid was found to be 10 -4 M. An enhancement factor of about 32000 was found in this ionic liquid compare to aqueous medium. Fluorescence life time of europium in this ionic liquid is 1100 μs which is ten times more than the life time of europium in aqueous medium (110 μs), indicating a reduction in the rates of non-radiative processes which was provided by the ionic liquid. This study leads to detection of europium in ppb level. (author)

Direct determination of beryllium, cadmium, lithium, lead and silver in thorium nitrate solution by electrothermal atomization atomic absorption spectrometry

International Nuclear Information System (INIS)

Thulasidas, S.K.; Kulkarni, M.J.; Porwal, N.K.; Page, A.G.; Sastry, M.D.

1988-01-01

An electrothermal atomization atomic absorption spectrometric (ET-AAS) method is developed for the direct determination of Ag, Be, Cd, Li and Pb in thorium nitrate solution. The method offers detection of sub-nanogram amounts of these analytes in 100-microgram thorium samples with a precision of around 10%. A number of spiked samples and pre-analyzed ThO 2 samples have been analyzed to evaluate the performance of the analytical methods developed here

Cooperative fluorescence from a strongly driven dilute cloud of atoms

DEFF Research Database (Denmark)

Ott, Johan Raunkjær; Wubs, Martijn; Lodahl, Peter

2013-01-01

We investigate cooperative fluorescence in a dilute cloud of strongly driven two-level emitters. Starting from the Heisenberg equations of motion, we compute the first-order scattering corrections to the saturation of the excited-state population and to the resonance-fluorescence spectrum, which...... both require going beyond the state-of-the-art linear-optics approach to describe collective phenomena. A dipole blockade is observed due to long-range dipole-dipole coupling that vanishes at stronger driving fields. Furthermore, we compute the inelastic component of the light scattered by a cloud...

The X-ray fluorescent method for determination of total sulphur in bituminous coals

International Nuclear Information System (INIS)

Widowska-Kusmierska, J.; Siess, K.

1979-01-01

The X-ray fluorescent technique for the determination of total sulphur covering concentrations from 0,1 to 10% has been applied for bituminous coals showing a great variability in qualitative and quantitative composition of mineral matter (ash). The described method is a quick one giving results during one hour. The obtained good accuracy of determinations gives prospects for wide industrial application. (author)

Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

Energy Technology Data Exchange (ETDEWEB)

Ang, C.Y.W.; Luo, Wenhong [National Center for Toxicological Research, Jefferson, AR (United States)

1997-01-01

A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.

Determination of mercury, lead and cadmium in water by the CRA-atomic absorption spectrophotometry with solvent extraction

International Nuclear Information System (INIS)

Shim, Y.B.; Won, M.S.; Kim, C.J.

1980-01-01

The method of CRA-atomic absorption spectrophotometer with solvent extraction for the determination of mercury, lead and cadmium in water was studied. The optimum extracting conditions for CRA-atomic absorption spectrophotometry were the following: the complexes of mercury, lead and cadmium with dithizone were separated from the aqueous solution and concentrated into the 10 ml chloroform solution. Back extraction was performed; the concentrated mercury, lead and cadmium was extracted from the chloroform solution into the 10 ml 6-normal aqueous hydrochloric acid solution. In this case, recovery ratios were the following: mercury was 94.7%, lead 97.7% and cadmium 103.6%. The optimum operating conditions for the determination of mercury, lead and cadmium by the CRA-atomic absorption spectrophotometry also were investigated to test the dry step, ash step and atomization step for each metal. The experimental results of standard addition method were the following: the determination limit of each metal within 6% relative deviation was that lead was 0.04 ppb, and cadmium 0.01 ppb. Especially, mercury has been known impossible to determine by CRA-atomic absorption spectrophotometry until now. But in this study, mercury can be determined with CRA-atomic absorption spectrophotometer. Its determination limit was 4 ppb within 8% relative deviation. (author)

Synthesis and atomic structure determination of Al8V5 gamma-brass

International Nuclear Information System (INIS)

Mizutani, Uichiro

2006-01-01

Many structurally complex compounds like quasicrystals and their approximants are known to be stabilized at a particular electron per atom ratio e/a, regardless of constituent elements involved. This has been often referred to as the Hume-Rothery electron concentration rule. We consider the understanding of the Hume-Rothery stabilization mechanism to be best deepened by performing both ab initio LMTO-ASA and FLAPW band calculations for the complex compound whose atomic structure is experimentally determined. Admittedly, however, a computing time increases rapidly beyond practical level with increasing the number of atoms in a unit cell. Among various candidates, we chose a series of gamma-brasses containing 52 atoms in a unit cell by taking a full advantage of the facts that it exists in as many as 24 binary alloy systems and that its unit cell is just in size to be handled even in more time-consuming FLAPW method. We have so far studied the stability mechanism of Cu 5 Zn 8 and Cu 9 Al 4 , both being regarded as its prototype, and TM 2 Zn 11 gamma-brasses containing late transition elements TM=Fe, Co, Ni and Pd. In the present work, we chose the gamma-brass consisting of early transition metal element V and trivalent element Al. An almost single phase Al 8 V 5 gamma-brass was ultimately synthesized by overcoming metallurgical difficulties encountered. Its atomic structure was determined by using the Brandon model as a starting structure in the Rietveld structure analysis for powdered diffraction spectra taken at the beam line BL02B2 of 8 GeV synchrotron radiation facility, SPring-8, Japan. The atomic structure suitable for band calculations was then proposed by eliminating quenched-in chemical disorder, i.e., partial mixing of Al and V atoms at given sites with minimum sacrifice. (author)

New fluorescence spectroscopic method for the simultaneous determination of alkaloids in aqueous extract of green coffee beans.

Science.gov (United States)

Yisak, Hagos; Redi-Abshiro, Mesfin; Chandravanshi, Bhagwan Singh

2018-05-11

There is no fluorescence spectroscopic method for the determination of trigonelline and theobromine in green coffee beans. Therefore, the objective of this study was to develop a new fluorescence spectroscopic method to determine the alkaloids simultaneously in the aqueous extract of green coffee beans. The calibration curves were linear in the range 2-6, 1-6, 1-5 mg/L for caffeine, theobromine and trigonelline, respectively, with R 2  ≥ 0.9987. The limit of detection and limit of quantification were 2, 6 and 7 µg/L and 40, 20 and 20 µg/L for caffeine, theobromine and trigonelline, respectively. Caffeine and trigonelline exhibited well separated fluorescence excitation spectra and therefore the two alkaloids were selectively quantified in the aqueous extract of green coffee. While theobromine showed overlapping fluorescence excitation spectra with caffeine and hence theobromine could not be determined in the aqueous extract of green coffee beans. The amount of caffeine and trigonelline in the three samples of green coffee beans were found to be 0.95-1.10 and 1.00-1.10% (w/w), respectively. The relative standard deviations (RSD ≤ 4%) of the method for the three compounds of interest were of very good. The accuracy of the developed analytical method was evaluated by spiking standard caffeine and trigonelline to green coffee beans and the average recoveries were 99 ± 2% for both the alkaloids. A fast, sensitive and reliable fluorescence method for the simultaneous determination of caffeine and trigonelline in the aqueous extract of green coffee beans was developed and validated. The developed method reflected an effective performance to the direct determination of the two alkaloids in the aqueous extract of green coffee beans.

An indirect method for determining phosphorus in aluminium alloys by atomic-absorption spectrometry.

Science.gov (United States)

Bernal, J L; Del Nozal, M A; Deban, L; Aller, A J

1981-07-01

An indirect method is described for the determination of phosphorus in aluminium alloys. Ammonium molybdate is added to a solution of the aluminium alloy and the molybdophosphoric acid formed is selectively extracted into n-butyl acetate. The twelve molybdenum atoms associated with each phosphate ion are determined by direct atomic-absorption spectrometry with the n-butyl acetate phase in a nitrous oxide-acetylene flame, with measurement at 313.2 nm. The most suitable conditions have been established and the effect of other ions has been studied.

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...

Determination of the cathode fall voltage in fluorescent lamps by measurement of the operating voltage

International Nuclear Information System (INIS)

Hilscher, A.

2002-01-01

A new method for the determination of the cathode fall voltage of fluorescent lamps is shown. The cathode fall voltage can be determined by measurement of the lamp operating voltage at constant lamp wall temperature, constant discharge current and variation of the electrode heating current. Commercial lamps, which do not need to be specially prepared, can be used for the measurement. The results show good correlation to other measurements of the cathode fall voltage at various discharge currents by means of capacitive coupling. The measured values of the cathode fall voltage are used for determining the minimum, target and maximum setting of the sum of the squares of the pin currents of one electrode (the so-called SOS value) as a function of the discharge current in fluorescent lamp dimming. (author)

Synthesis and novel fluorescence phenomenon of terbium(III) complex with N, N',N' -tris (2-benzimidazolmethyl) amine

International Nuclear Information System (INIS)

Yang, Tianlin; Gao, Min; Yang, Jinhui; Qin, Wenwu

2010-01-01

A benzimidazole ligand with a tripodal structure, N, N', N' -tris (2-benzimidazolmethyl) amine, and its terbium (III) complex has been synthesized. The complex has been characterized by element analysis, IR spectra, mass spectra, thermal analysis and molar conductivity. The terbium ion is found to coordinate with the nitrogen atoms (= N-) of imidazole ring and the bridgehead nitrogen atom. The fluorescence properties of the complex in aqueous solutions have been studied. Under excitation of UV light, the complex exhibits characteristic fluorescence of terbium ion. The luminescence of terbium complex in aqueous solutions is strongly enhanced by H + concentration. This phenomenon makes the new complex favorable for use in fluorescence switches and sensors. The mechanism of the fluorescence enhancement by protonation of the nitrogen atoms (-NH-) of imidazole ring is due to the suppressed photoinduced electron transfer fluorescence quenching on addition of acid. (author)

Determining the ice-binding planes of antifreeze proteins by fluorescence-based ice plane affinity.

Science.gov (United States)

Basu, Koli; Garnham, Christopher P; Nishimiya, Yoshiyuki; Tsuda, Sakae; Braslavsky, Ido; Davies, Peter

2014-01-15

Antifreeze proteins (AFPs) are expressed in a variety of cold-hardy organisms to prevent or slow internal ice growth. AFPs bind to specific planes of ice through their ice-binding surfaces. Fluorescence-based ice plane affinity (FIPA) analysis is a modified technique used to determine the ice planes to which the AFPs bind. FIPA is based on the original ice-etching method for determining AFP-bound ice-planes. It produces clearer images in a shortened experimental time. In FIPA analysis, AFPs are fluorescently labeled with a chimeric tag or a covalent dye then slowly incorporated into a macroscopic single ice crystal, which has been preformed into a hemisphere and oriented to determine the a- and c-axes. The AFP-bound ice hemisphere is imaged under UV light to visualize AFP-bound planes using filters to block out nonspecific light. Fluorescent labeling of the AFPs allows real-time monitoring of AFP adsorption into ice. The labels have been found not to influence the planes to which AFPs bind. FIPA analysis also introduces the option to bind more than one differently tagged AFP on the same single ice crystal to help differentiate their binding planes. These applications of FIPA are helping to advance our understanding of how AFPs bind to ice to halt its growth and why many AFP-producing organisms express multiple AFP isoforms.

Halogenated salicylaldehyde azines: The heavy atom effect on aggregation-induced emission enhancement properties

International Nuclear Information System (INIS)

Chen, Xiao-tong; Tong, Ai-jun

2014-01-01

This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. For this purpose, a series of halogenated salicylaldehyde azine derivatives, namely, chloro-salicylaldehyde azine (1), bromo-salicylaldehyde azine (2) and iodo-salicylaldehyde azine (3) are synthesized. 1 and 2 display typical AIEE characteristics of salicylaldehyde azine compounds; whereas for the iodo-substituent in 3, is found to be effective “external” heavy atom quenchers to salicylaldehyde azine fluorescence in aggregated state. Based on its weak fluorescence in aggregated state and relative strong fluorescence in dispersed state, 3 can also be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction. -- Highlights: • This study investigates the heavy-atom effect (HAE) on aggregation-induced emission enhancement (AIEE) properties of salicylaldehyde azines. • Chloro- and bromo-salicylaldehyde display typical AIEE properties of salicylaldehyde azine, whereas the iodo-substitute quenches AIEE in aggregated state. • Iodo-salicylaldehyde can be applied as a turn-on fluorescence probe for egg albumin detection attributed to hydrophobic interaction

Determination of Ivermectin in Medicated Feeds by Liquid Chromatography with Fluorescence Detection

Science.gov (United States)

2013-01-01

A labour- and time-effective analytical procedure for determination of ivermectin in medicated feed at recommended level of 2.0 mg kg−1 has been developed and validated. The analyte was extracted from grinded feed samples with acetonitrile and derivatisated with N-methylimidazole and trifluoracetic anhydride. The fluorescent derivatives were analysed by liquid chromatography method using C8 column. The isocratic conditions using acetonitrile, methanol, water, and tetrahydrofuran were applied. Fluorescence detection was performed at 365 nm (excitation) and 475 nm (emission) wavelengths. The total analysis time was 10 min. The validation results of the method (within-laboratory reproducibility 4.0% CV, mean recovery 100.1%) confirm the appropriate precision and accuracy of the developed method. PMID:24453835

Chlorine determination in (U, Pu)C fuel by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Misra, Nand Lal; Dhara, Sangita; Mudher, Khush Dev Singh; Aggarwal, Suresh K.; Thakur, Uday Kumar; Shah, Dipti; Sawant, R.M.; Ramakumar, K.L.

2007-01-01

A Total Reflection X-ray Fluorescence (TXRF) method for the determination of chlorine in (U,Pu)C has been developed. The method involves calibration of the instrument with standard solutions and validation of TXRF determination of chlorine using synthetic standard solutions. Cl K α line excited with W L α source was used for TXRF determinations of chlorine. Chlorine present in trace amounts in (U,Pu)C samples was first separated by pyro hydrolysis. The evolved chlorine, in form of HCl, was collected in 5 mM NaOH solution. This solution was analyzed for chlorine by Total Reflection X-ray Fluorescence Spectrometry using cobalt as an internal standard. The TXRF detection limit of chlorine was found to be 3.6 pg with sample size of 30 μL. In order to assess the applicability of TXRF method for chlorine determinations in other nuclear materials, one U 3 O 8 trace element standard was also analyzed for chlorine in similar way. The precision of the method was found to be 25% (1 σ) at ng level in most of the cases. (author)

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Some applications of x-ray fluorescence spectrography to the determination of uranium and thorium

International Nuclear Information System (INIS)

Jones, R.W.

1959-04-01

Several methods for the determination of uranium and thorium by X-ray fluorescence spectrography are described. In pure solutions the sensitivity for these elements is 5-10 ppm. For solutions containing gross concentrations of impurities, strontium is added as an internal standard. Precision and accuracy of the determinations are about 1% when working in the optimum concentration range. (author)

Determinations of silicon and phosphorus in Pepperbush standard reference material by neutron activation and x-ray fluorescence methods

International Nuclear Information System (INIS)

Mizumoto, Yoshihiko; Nishio, Hirofumi; Hayashi, Takeshi; Kusakabe, Toshio; Iwata, Shiro.

1987-01-01

Silicon and phosphorus contents in Pepperbush standard reference material were determined by neutron activation and X-ray fluorescence methods. In neutron activation analysis, β-ray spectra of 32 P produced by 31 P(n,γ) 32 P reaction on Pepperbush and standard samples were measured by a low background β-ray spectrometer. In X-ray fluorescence analysis, the standard samples were prepared by mixing the Pepperbush powder with silicon dioxide and diammonium hydrogenphosphate. Characteristic X-rays from the samples were analyzed by a wavelength dispersive X-ray fluorescence spectrometer. From the β and X-ray intensities, silicon and phosphorus contents in Pepperbush were determined to be 1840 ± 80 and 1200 ± 50 μg g -1 , respectively. (author)

Flotation atomic absorption determination of bismuth in nonferrous metal alloys

International Nuclear Information System (INIS)

Ososkov, V.K.; Plintus, A.M.; Kornelli, M.Eh.; Zakhariya, A.N.; Lozanova, E.V.

1986-01-01

Technique of flotation concentration and atomic absorption determination of bismuth microquantities in alloys on the basis of copper and zinc has been developed. Fine-dispersed EhDEh-10P anionite was used as a carrier in flotation concentration. State standard samples (SSS) of brasses and German silver were used as analysed objects. Effect of macrocomponents on the results of bismuth content determination has been studied. Satisfactory coincidence of the results obtained and SSS certificates is shown

Fluorescent investigation of the interactions between N-(p-chlorophenyl)-N'-(1-naphthyl) thiourea and serum albumin: Synchronous fluorescence determination of serum albumin

International Nuclear Information System (INIS)

Cui Fengling; Wang Junli; Cui Yanrui; Li Jianping

2006-01-01

The interactions between N-(p-chlorophenyl)-N'-(1-naphthyl) thiourea and serum albumin were investigated by fluorescence spectroscopy and UV absorption spectrum under physiological conditions. The results of spectroscopic measurements suggested that N-(p-chlorophenyl)-N'-(1-naphthyl) thiourea should have a strong ability to quench the intrinsic fluorescence of both bovine serum albumin and human serum albumin through static quenching procedure, and the hydrophobic interaction was the predominant intermolecular force stabilizing the complex. Thermodynamic parameter enthalpy changes (ΔH) and entropy changes (ΔS) were calculated according to the Vant'Hoff equation. The binding distances between N-(p-chlorophenyl)-N'-(1-naphthyl) thiourea and the proteins were evaluated on the basis of the theory of Foester energy transfer. In addition, the effects of other ions on the binding constants of complexes were also discussed. Synchronous fluorescence technology was successfully applied to the determination of serum albumins added to the CPNT solution

Detection of atomic and molecular hydrogen in post-discharge by resonant multi-photo-ionisation. Determination of absolute atomic densities

International Nuclear Information System (INIS)

Persuy, Philippe

1990-01-01

Within the frame of studies on devices for physical vapour deposition, and on phenomena leading to these depositions, this research thesis reports the development of a laser-diagnosis based on the phenomenon of resonant multi-photo-ionisation, and an attempt to obtain from it values of the absolute concentration of atomic hydrogen. After some recalls on the diversity of multi-photon phenomena, their theoretical and experimental evolutions, and on the particular role of hydrogen, the author reports experiments performed at 307.7 and 364.7 nm which respectively addressed the post-discharge detection of molecular hydrogen and of atomic hydrogen. A model is presented which addresses the interaction volume, and results of experiments of atom multi-photo-ionisation are reported. One of the results of this model is an assessment of the cross-section of the excitation with three photons of the hydrogen atom. This result is then used to determine the absolute density of atoms in fundamental state for different discharge conditions. Finally, the author presents the calculation software and some curve examples displaying the evolution of the number of ions and of excited states within the interaction volume [fr

Sorghum cobalt analysis on not determined wave length with atomic ...

African Journals Online (AJOL)

This study was to know the better wave length on measuring cobalt content in forage sorghum hybrid (Sorghum bicolor) with an atomic absorption spectrophotometer. The analysis was on background correction mode with three wave lengths; 240.8, 240.7 (determined wave length or recommended wave length) and 240.6 ...

Continuous determination of gaseous ammonia in the ambient atmosphere using fluorescence derivatization

Science.gov (United States)

Abbas, Rana; Tanner, Roger L.

A method for continuous determination of ambient ammonia levels employing o-phthalaldehyde fluorescence derivatization is described. A simplified Venturi scrubber and gas-liquid separator have been employed for reproducible measurements of ⩾ 0.1 ppb ambient ammonia with less than 2 min time resolution. The scrubbing efficiency of the ammonia gas collection system was determined to be 29 ± 1 %. During 4 d in August 1979 ambient ammonia levels at the Brookhaven National Laboratory site averaged about 1.5 ± 1.1 ppb during afternoon daylight hours.

Alternative approaches to correct interferences in the determination of boron in shrimps by electrothermal atomic absorption spectrometry

Energy Technology Data Exchange (ETDEWEB)

Pasias, I.N.; Pappa, Ch.; Katsarou, V.; Thomaidis, N.S., E-mail: ntho@chem.uoa.gr; Piperaki, E.A.

2014-02-01

The aim of this study is to propose alternative techniques and methods in combination with the classical chemical modification to correct the major matrix interferences in the determination of boron in shrimps. The performance of an internal standard (Ge) for the determination of boron by the simultaneous multi-element atomic absorption spectrometry was tested. The use of internal standardization increased the recovery from 85.9% to 101% and allowed a simple correction of errors during sampling preparation and heating process. Furthermore, a new preparation procedure based on the use of citric acid during digestion and dilution steps improved the sensitivity of the method and decreased the limit of detection. Finally, a comparative study between the simultaneous multi-element atomic absorption spectrometry with a longitudinal Zeeman-effect background correction system, equipped with a transversely-heated graphite atomizer and the single element atomic absorption spectrometry with a D{sub 2} background correction system, equipped with an end-heated graphite atomizer was undertaken to investigate the different behavior of boron in both techniques. Different chemical modifiers for the determination of boron were tested with both techniques. Ni-citric acid and Ca were the optimal chemical modifiers when simultaneous multi-element atomic absorption spectrometry and single-element atomic absorption spectrometry were used, respectively. By using the single-element atomic absorption spectrometry, the calculated characteristic mass was 220 pg and the calculated limit of detection was 370 μg/kg. On the contrary, with simultaneous multi-element atomic absorption spectrometry, the characteristic mass was 2200 pg and the limit of detection was 5.5 mg/kg. - Highlights: • New approaches were developed to cope with interferences of B determination by ETAAS • Ge was used as internal standard for the determination of B by simultaneous ETAAS • Citric acid was used during

Photoionization of atoms and molecules

International Nuclear Information System (INIS)

Samson, J.A.R.

1976-01-01

A literature review on the present state of knowledge in photoionization is presented. Various experimental techniques that have been developed to study photoionization, such as fluorescence and photoelectron spectroscopy, mass spectroscopy, are examined. Various atoms and molecules were chosen to illustrate these techniques, specifically helium and xenon atoms and hydrogen molecules. Specialized photoionization such as in positive and negative ions, excited states, and free radicals is also treated. Absorption cross sections and ionization potentials are also discussed

Fluorescence method for the determination of carcinogenic N-nitrosamines using N-(8-methoxy-5-quinolinesulfonyl)-aziridine

International Nuclear Information System (INIS)

Gracheva, I.N.; Kovel'man, I.R.; Pimenova, V.V.; Tochilkin, A.I.; Zhukova, G.F.

1986-01-01

The determination of carcinogenic N-nitrosamines (NA) in the environment and particularly in food products is, according to the authors, extremely important. The objective of the present work is the development of an easily accessible and highly sensitive method for the determination of NA. NA, isolated from food products, are denitrosated to their corresponding amines, which are then determined in the form of fluorescent derivatives by reaction with N-(8-methoxy-5-quinolinesulfonyl) aziridine. The validity of the results of NA analysis from food product was confirmed by gas-liquid chromatography using a thermoluminescent detector TEA-502. The limit of detection is 1x10 -10 mole of N-nitrosamine. The possibility of separating and determining the new fluorescent derivatives III(a-f) on silufol plates, which are easily obtained and widely used in analytical practice, was examined

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

International Nuclear Information System (INIS)

Bentlin, Fabrina R.S.; Pozebon, Dirce; Mello, Paola A.; Flores, Erico M.M.

2007-01-01

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 3 ) 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 μg g -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)

Determination of the D/T fuel mixture using two-photon laser induced fluorescence in combination with neutral beam injection

International Nuclear Information System (INIS)

Voslamber, D.; Mandl, W.

1997-08-01

Doppler-free two-photon induced fluorescence in the Lyman-α lines of H, D and T has been suggested previously as a local and isotope-selective diagnostic of the intrinsic neutral hydrogen densities in magnetically confined fusion plasmas. In the present paper it is shown that the diagnostic potential of this method is significantly increased if it is combined with neutral atom beams whose characteristics are such that efficient production of thermal ground state atoms via charge exchange reactions is achieved. Considerably deeper plasma regions than just the plasma edge can thus be probed and local, isotope-selective information is obtained on the more relevant ions rather than on the neutrals. Additional diagnostic possibilities, e.g. those arising from the spectroscopic investigation of the beam particles themselves, are also discussed. (author)

Characterization of an atom beam produced with the help of a hollow-cathode discharge

International Nuclear Information System (INIS)

Babin, F.; Gagne, J.

1986-01-01

A hollow-cathode type discharge is used as a refractory element vapor generator for the formation of an atomic beam. The development of the technique brings us to discuss its possibilities in spectroscopic studies of refractory elements. We focus primarily on the production of a uranium atomic beam and its characterization by laser-induced fluorescence spectroscopy. We determine, among other things, the beam divergence and the most probable velocity along its axis for specific current and pressure conditions in the discharge. We also discuss beam behavior with respect to buffer gas pressure and electric current in the discharge

Determination of inorganic arsenic in algae using bromine halogenation and on-line nonpolar solid phase extraction followed by hydride generation atomic fluorescence spectrometry.

Science.gov (United States)

Zhang, Weihong; Qi, Yuehan; Qin, Deyuan; Liu, Jixin; Mao, Xuefei; Chen, Guoying; Wei, Chao; Qian, Yongzhong

2017-08-01

Accurate, stable and fast analysis of toxic inorganic arsenic (iAs) in complicated and arsenosugar-rich algae matrix is always a challenge. Herein, a novel analytical method for iAs in algae was reported, using bromine halogenation and on-line nonpolar solid phase extraction (SPE) followed by hydride generation atomic fluorescence spectrometry (HG-AFS). The separation of iAs from algae was first performed by nonpolar SPE sorbent using Br - for arsenic halogenation. Algae samples were extracted with 1% perchloric acid. Then, 1.5mL extract was reduced by 1% thiourea, and simultaneously reacted (for 30min) with 50μL of 10% KBr for converting iAs to AsBr 3 after adding 3.5mL of 70% HCl to 5mL. A polystyrene (PS) resin cartridge was employed to retain arsenicals, which were hydrolyzed, eluted from the PS resin with H 2 O, and categorized as iAs. The total iAs was quantified by HG-AFS. Under optimum conditions, the spiked recoveries of iAs in real algae samples were in the 82-96% range, and the method achieved a desirable limit of detection of 3μgkg -1 . The inter-day relative standard deviations were 4.5% and 4.1% for spiked 100 and 500μgkg -1 respectively, which proved acceptable for this method. For real algae samples analysis, the highest presence of iAs was found in sargassum fusiforme, followed by kelp, seaweed and laver. Copyright © 2017 Elsevier B.V. All rights reserved.

Utilization of electrodeposition for electrothermal atomic absorption spectrometry determination of gold

International Nuclear Information System (INIS)

Konecna, Marie; Komarek, Josef

2007-01-01

Gold was determined by electrothermal atomic absorption spectrometry after electrochemical preconcentration on the graphite ridge probe used as a working electrode and sample support. The probe surface was electrochemically modified with Pd, Re and the mixture of both. The electrolysis of gold was performed under galvanostatic control at 0.5 mA. Maximum pyrolysis temperature for the probe surface modified with Pd was 1200 deg. C, with Re 1300 deg. C. The relative standard deviation for the determination of 2 μg l -1 Au was not higher than 5.6% (n = 8) for 2 min electrodeposition. The sensitivity of gold determination was reproducible for 300 electrodeposition and atomization cycles. When the probe surface was modified with a mixture of Pd and Re the detection limit was 31 ng l -1 for 2 min electrodeposition, 3.7 ng l -1 for 30 min, 1.5 ng l -1 for 1 h and 0.4 ng l -1 for 4 h electrodeposition, respectively. The procedure was applied to the determination of gold in river water samples. The relative standard deviation for the determination of 2.5 ng l -1 Au at 4 h electrodeposition time at 0.5 mA was 7.5%

X-ray fluorescence holography: A different approach to data collection

International Nuclear Information System (INIS)

Busetto, E.; Kopecky, M.; Lausi, A.; Menk, R.H.; Miculin, M.; Savoia, A.

2000-01-01

The images of nearest neighbors of gallium atoms in a GaAs crystal were obtained by the x-ray fluorescence holography technique. The fluorescence from gallium atoms was selected by means of a thin zinc foil filter that made possible the use of an x-ray silicon photodiode detector without energy resolution. This method makes possible the detection of a much higher signal with respect to all previous experiments, thus reducing drastically measuring times, that is a basic and essential step from contemporary demonstration experiments to possible practical applications of x-ray holography in structure analysis

Choice of excitation source for determination of rare earth elements with radioisotope excited X ray fluorescence

International Nuclear Information System (INIS)

Zhang Quanshi; Chang Yongfu

2000-01-01

The comparisons of two radioisotope source ( 241 Am and 238 Pu) which are the most available in the radioisotope excited X Ray Fluorescence (XRF) analysis technique and two characteristic X ray series (KX and LX) analyzed for the determination of the rare-earth (RE) elements were investigated in detail. According to the principle of emission and detection of X ray , the relative excitation efficiencies were calculated by the some fundamental physical parameters including the photoelectric mass attenuation coefficient, the fluorescent yield, the absorption jump factor, the emission probability of the detected fluorescent line with reference to other liens of the same series etc., The advantages and disadvantages of the two conditions are discussed. These results may determine the optimal excitation and detection conditions for different rare-earth elements. The experimental results with nine rare-earth elements (Ce, Nd, Sm, Tb, Tm, Ho, Er, Yb and Lu) are in agreement with the results of theoretical calculations

Time-resolved laser-induced fluorescence system

Science.gov (United States)

Bautista, F. J.; De la Rosa, J.; Gallegos, F. J.

2006-02-01

Fluorescence methods are being used increasingly in the measurement of species concentrations in gases, liquids and solids. Laser induced fluorescence is spontaneous emission from atoms or molecules that have been excited by laser radiation. Here we present a time resolved fluorescence instrument that consists of a 5 μJ Nitrogen laser (337.1 nm), a sample holder, a quartz optical fiber, a spectrometer, a PMT and a PC that allows the measurement of visible fluorescence spectra (350-750 nm). Time response of the system is approximately 5 ns. The instrument has been used in the measurement of colored bond paper, antifreeze, diesel, cochineal pigment and malignant tissues. The data acquisition was achieved through computer control of a digital oscilloscope (using General Purpose Interface Bus GPIB) and the spectrometer via serial (RS232). The instrument software provides a graphic interface that lets make some data acquisition tasks like finding fluorescence spectra, and fluorescence lifetimes. The software was developed using the Lab-View 6i graphic programming package and can be easily managed in order to add more functions to it.

Superresolution size determination in fluorescence microscopy: A comparison between spatially modulated illumination and confocal laser scanning microscopy

International Nuclear Information System (INIS)

Spoeri, Udo; Failla, Antonio Virgilio; Cremer, Christoph

2004-01-01

Recently developed far field light optical methods are a powerful tool to analyze biological nanostructures and their dynamics, in particular including the interior of three-dimensionally conserved cells. In this article, the recently described method of spatially modulated illumination (SMI) microscopy has been further extended to the online determination of the extension of small, subwavelength sized, fluorescent objects (nanosizing). Using fluorescence excitation with 488 nm, the determination of fluorescent labeled object diameters down to 40 nm corresponding to about 1/12th of the wavelength used for one-photon excitation could be shown. The results of the SMI nanosizing procedure for a detailed, systematic variation of the object diameter are presented together with a fast algorithm for online size evaluation. In addition, we show a direct comparison of the diameter of 'colocalization volumes' between SMI nanosizing and conventional confocal laser scanning microscopy

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...

Fluorescent optical position sensor

Science.gov (United States)

Weiss, Jonathan D.

2005-11-15

A fluorescent optical position sensor and method of operation. A small excitation source side-pumps a localized region of fluorescence at an unknown position along a fluorescent waveguide. As the fluorescent light travels down the waveguide, the intensity of fluorescent light decreases due to absorption. By measuring with one (or two) photodetectors the attenuated intensity of fluorescent light emitted from one (or both) ends of the waveguide, the position of the excitation source relative to the waveguide can be determined by comparing the measured light intensity to a calibrated response curve or mathematical model. Alternatively, excitation light can be pumped into an end of the waveguide, which generates an exponentially-decaying continuous source of fluorescent light along the length of the waveguide. The position of a photodetector oriented to view the side of the waveguide can be uniquely determined by measuring the intensity of the fluorescent light emitted radially at that location.

Hue-shifted monomeric variants of Clavularia cyan fluorescent protein: identification of the molecular determinants of color and applications in fluorescence imaging

Directory of Open Access Journals (Sweden)

Davidson Michael W

2008-03-01

mutagenesis study, we conclude that the two histidine residues in close proximity to the chromophore are approximately equal determinants of the blue-shifted fluorescence emission of mTFP1. With respect to live cell imaging applications, the mTFP1-derived mWasabi should be particularly useful in two-color imaging in conjunction with a Sapphire-type variant or as a fluorescence resonance energy transfer acceptor with a blue FP donor. In all fusions attempted, both mTFP1 and mWasabi give patterns of fluorescent localization indistinguishable from that of well-established avGFP variants.

The determination, by x-ray-fluorescence spectrometry, of gold in activated charcoal

International Nuclear Information System (INIS)

Austen, C.E.

1977-01-01

A rapid method is described for the determination of gold in activated charcoal by X-ray-fluorescence spectrometry. Compensation for matrix effects is achieved by means of platinum that is added for use as an internal standard. Calibration is achieved by use of a series of synthetic standards that are made by the spiking of barren charcoal with gold and platinum. The limit of determination is about 8 p.p.m. of gold, and the relative standard deviation is 1,2 per cent at a concentration level of 2300 p.p.m

Fluorescent carbon quantum dot hydrogels for direct determination of silver ions.

Science.gov (United States)

Cayuela, A; Soriano, M L; Kennedy, S R; Steed, J W; Valcárcel, M

2016-05-01

The paper reports for the first time the direct determination of silver ion (Ag(+)) using luminescent Carbon Quantum Dot hydrogels (CQDGs). Carbon Quantum Dots (CQDs) with different superficial moieties (passivate-CQDs with carboxylic groups, thiol-CQDs and amine-CQDs) were used to prepare hybrid gels using a low molecular weight hydrogelator (LMWG). The use of the gels results in considerable fluorescence enhancement and also markedly influences selectivity. The most selective CQDG system for Ag(+) ion detection proved to be those containing carboxylic groups onto their surface. The selectivity towards Ag(+) ions is possibly due to its flexible coordination sphere compared with other metal ions. This fluorescent sensing platform is based on the strong Ag-O interaction which can quench the photoluminescence of passivate-CQDs (p-CQDs) through charge transfer. The limit of detection (LOD) and quantification (LOQ) of the proposed method were 0.55 and 1.83µgmL(-1), respectively, being applied in river water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Green Synthesis of Fluorescent Carbon Dots for Selective Detection of Tartrazine in Food Samples.

Science.gov (United States)

Xu, Hua; Yang, Xiupei; Li, Gu; Zhao, Chuan; Liao, Xiangjun

2015-08-05

A simple, economical, and green method for the preparation of water-soluble, high-fluorescent carbon quantum dots (C-dots) has been developed via hydrothermal process using aloe as a carbon source. The synthesized C-dots were characterized by atomic force microscope (AFM), transmission electron microscopy (TEM), fluorescence spectrophotometer, UV-vis absorption spectra as well as Fourier transform infrared spectroscopy (FTIR). The results reveal that the as-prepared C-dots were spherical shape with an average diameter of 5 nm and emit bright yellow photoluminescence (PL) with a quantum yield of approximately 10.37%. The surface of the C-dots was rich in hydroxyl groups and presented various merits including high fluorescent quantum yield, excellent photostability, low toxicity and satisfactory solubility. Additionally, we found that one of the widely used synthetic food colorants, tartrazine, could result in a strong fluorescence quenching of the C-dots through a static quenching process. The decrease of fluorescence intensity made it possible to determine tartrazine in the linear range extending from 0.25 to 32.50 μM, This observation was further successfully applied for the determination of tartrazine in food samples collected from local markets, suggesting its great potential toward food routine analysis. Results from our study may shed light on the production of fluorescent and biocompatible nanocarbons due to our simple and environmental benign strategy to synthesize C-dots in which aloe was used as a carbon source.

[Research on optimization of mathematical model of flow injection-hydride generation-atomic fluorescence spectrometry].

Science.gov (United States)

Cui, Jian; Zhao, Xue-Hong; Wang, Yan; Xiao, Ya-Bing; Jiang, Xue-Hui; Dai, Li

2014-01-01

Flow injection-hydride generation-atomic fluorescence spectrometry was a widely used method in the industries of health, environmental, geological and metallurgical fields for the merit of high sensitivity, wide measurement range and fast analytical speed. However, optimization of this method was too difficult as there exist so many parameters affecting the sensitivity and broadening. Generally, the optimal conditions were sought through several experiments. The present paper proposed a mathematical model between the parameters and sensitivity/broadening coefficients using the law of conservation of mass according to the characteristics of hydride chemical reaction and the composition of the system, which was proved to be accurate as comparing the theoretical simulation and experimental results through the test of arsanilic acid standard solution. Finally, this paper has put a relation map between the parameters and sensitivity/broadening coefficients, and summarized that GLS volume, carrier solution flow rate and sample loop volume were the most factors affecting sensitivity and broadening coefficients. Optimizing these three factors with this relation map, the relative sensitivity was advanced by 2.9 times and relative broadening was reduced by 0.76 times. This model can provide a theoretical guidance for the optimization of the experimental conditions.

Sensitization of uranium fluorescence using 2,6-pyridinedicarboxylic acid: Application for the determination of uranium in the presence of lanthanides

International Nuclear Information System (INIS)

Maji, S.; Viswanathan, K.S.

2009-01-01

The 2,6-pyridinedicarboxylic acid (PDA) has been shown to efficiently sensitize and enhance the fluorescence of uranium in aqueous medium. Interestingly, this ligand stabilizes the UO 2 2+ species, which without the ligand is known to be in a negligible concentration, in aqueous medium at pH 6. The ligand sensitized enhancement of UO 2 2+ fluorescence by PDA, provides an analytical tool for the determination of uranium at trace levels, in aqueous medium. Furthermore, PDA is also known to enhance the fluorescence of lanthanides; consequently, the simultaneous determination of uranium and lanthanides, using PDA as a fluorescence sensitizing agent, becomes a possibility, which has been demonstrated in this work. We have shown that the use of PDA yields detection limits of 2.2x10 -7 M for UO 2 2+ , 1x10 -8 M for Tb 3+ and 5x10 -9 M for Eu 3+ in the simultaneous determination of these analytes.

Determinations of elements in pepperbush standard reference material by neutron activation and X-ray fluorescence analyses

International Nuclear Information System (INIS)

Mizumoto, Yoshihiko; Okada, Takayuki; Tatsumi, Toshiya; Kusakabe, Toshio; Katsurayama, Kousuke; Iwata, Shiro.

1988-01-01

Elemental contents in Pepperbush standard reference material have been determined by neutron activation and X-ray fluorescence analyses. The standard samples of orchard leaves, tomato leaves, pine needles and Kale are used for the experiment. In the neutron activation analysis, gamma-ray spectra of nuclei produced by (n,γ) reaction on Pepperbush and standard samples are measured with Ge detectors. In the X-ray fluorescence analysis, the samples are excited with X-rays from X-ray tube with rhodium anode, and the characteristic X-rays from samples are measured with a proportional counter or NaI(Tl) detector. From the gamma- and X-ray intensities, the elemental contents in Pepperbush are determined. As a result, the contents of seventeen elements, such as sodium, calcium, iron, etc., in Pepperbush are determined. (author)

Imaging C. elegans with thiolated tryptophan-based NIR fluorescent gold nanoclusters

Energy Technology Data Exchange (ETDEWEB)

Barman, Apurba Kr. [Indian Institute of Technology Kanpur, Department of Chemistry (India); Chaturbedi, Amaresh; Subramaniam, K. [Indian Institute of Technology Kanpur, Department of Biological Sciences and Bioengineering (India); Verma, Sandeep, E-mail: sverma@iitk.ac.in [Indian Institute of Technology Kanpur, Department of Chemistry (India)

2013-11-15

Multidentate, thiolated, tryptophan-containing peptide conjugates were synthesized for the preparation of gold nanoclusters (AuNCs). Precursor Au{sub 11}(PPh{sub 3}){sub 8}Cl{sub 3} was prepared by the reduction of HAuCl{sub 4}, followed by the use of tryptophan-containing peptide conjugates in ligand displacement reactions, to afford near-infrared fluorescent AuNCs. The emission maxima for these newly synthesized AuNCs were ∼715 nm. AuNCs were characterized with the help of UV–Vis, FTIR, fluorescence and MALDI analysis. FTIR spectra showed that the ligands bind to Au atoms through Au–S bonds, while MALDI mass spectra revealed that the clusters consisted of 20–23 Au atoms. Introduction of hydrophilic –COOH groups engendered water solubility to these AuNCs, enabling bioimaging applications. We demonstrate fluorescence imaging of the nematode C. elegans and confirm distribution of these AuNCs in nematode gut with the help of green fluorescent protein co-localization experiments.

Determination of low concentrations of thorium in geological materials by X-ray fluorescence

International Nuclear Information System (INIS)

Roca, M.; Bayon, A.

1981-01-01

An X-ray fluorescence method for the determination of thorium in geological samples down to 2 ppm ThO 2 has been developed. To achieve this determination limit an exposed area of the sample 42.5 mm in diameter is used, working with a molybdenum target tube operated at 90 kV and 30 m A. Corrections for background and line interference of the Rb Kα radiation have been carefully considered and empirical correction coefficients calculated. (Author) 3 refs

Arsenic speciation in edible alga samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Garcia-Salgado, S. [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain); Quijano, M.A., E-mail: marian.quijano@upm.es [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain); Bonilla, M.M. [Departamento de Ingenieria Civil: Tecnologia Hidraulica y Energetica, Escuela Universitaria de Ingenieria Tecnica de Obras Publicas, Universidad Politecnica de Madrid, Alfonso XII 3 y 5, 28014 Madrid (Spain)

2012-02-10

Highlights: Black-Right-Pointing-Pointer Total As and As species were analyzed in edible marine algae. Black-Right-Pointing-Pointer A microwave-assisted extraction method with deionized water was applied. Black-Right-Pointing-Pointer As compounds identified comprised DMA, As(V) and four arsenosugars Black-Right-Pointing-Pointer Considerably high As(V) concentrations were found in the most of the algae studied. - Abstract: Twelve commercially available edible marine algae from France, Japan and Spain and the certified reference material (CRM) NIES No. 9 Sargassum fulvellum were analyzed for total arsenic and arsenic species. Total arsenic concentrations were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) after microwave digestion and ranged from 23 to 126 {mu}g g{sup -1}. Arsenic species in alga samples were extracted with deionized water by microwave-assisted extraction and showed extraction efficiencies from 49 to 98%, in terms of total arsenic. The presence of eleven arsenic species was studied by high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation atomic-fluorescence spectrometry (HPLC-(UV)-HG-AFS) developed methods, using both anion and cation exchange chromatography. Glycerol and phosphate sugars were found in all alga samples analyzed, at concentrations between 0.11 and 22 {mu}g g{sup -1}, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2 {mu}g g{sup -1}). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (<0.9 {mu}g g{sup -1}) and generally high arsenate (As(V)) concentrations (up to 77 {mu}g g{sup -1}) were found in most of the algae studied. The results obtained are of interest to highlight the need to perform speciation analysis and to introduce appropriate legislation to limit toxic arsenic species content in these food products.

Atomic physics at high brilliance synchrotron sources: Proceedings

International Nuclear Information System (INIS)

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

1994-08-01

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

Energetic electron processes fluorescence effects for structured nanoparticles X-ray analysis and nuclear medicine applications

Energy Technology Data Exchange (ETDEWEB)

Taborda, A.; Desbrée, A. [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PRP-HOM/SDI/LEDI, BP-17, 31, Avenue de la Division Leclerc, 92262 Fontenay-aux-Roses (France); Carvalho, A. [IEQUALTECS, Lda, Rua Dr. Francisco Sá Carneiro, 36, 2500-065 S. Gregório CLD (Portugal); Chaves, P.C. [C" 2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, EN10 km 139.7, 2685-066 Bobadela LRS (Portugal); Reis, M.A., E-mail: mareis@ctn.tecnico.ulisboa.pt [IEQUALTECS, Lda, Rua Dr. Francisco Sá Carneiro, 36, 2500-065 S. Gregório CLD (Portugal); C" 2TN, Campus Tecnológico e Nuclear, Instituto Superior Técnico, Universidade de Lisboa, EN10 km 139.7, 2685-066 Bobadela LRS (Portugal)

2016-08-15

Superparamagnetic iron oxide (SPIO) nanoparticles are widely used as contrast agents for nuclear magnetic resonance imaging (MRI), and can be modified for improved imaging or to become tissue-specific or even protein-specific. The knowledge of their detailed elemental composition characterisation and potential use in nuclear medicine applications, is, therefore, an important issue. X-ray fluorescence techniques such as particle induced X-ray emission (PIXE) or X-ray fluorescence spectrometry (XRF), can be used for elemental characterisation even in problematic situations where very little sample volume is available. Still, the fluorescence coefficient of Fe is such that, during the decay of the inner-shell ionised atomic structure, keV Auger electrons are produced in excess to X-rays. Since cross-sections for ionisation induced by keV electrons, for low atomic number atoms, are of the order of 10{sup 3} barn, care should be taken to account for possible fluorescence effects caused by Auger electrons, which may lead to the wrong quantification of elements having atomic number lower than the atomic number of Fe. Furthermore, the same electron processes will occur in iron oxide nanoparticles containing {sup 57}Co, which may be used for nuclear medicine therapy purposes. In the present work, simple approximation algorithms are proposed for the quantitative description of radiative and non-radiative processes associated with Auger electrons cascades. The effects on analytical processes and nuclear medicine applications are quantified for the case of iron oxide nanoparticles, by calculating both electron fluorescence emissions and energy deposition on cell tissues where the nanoparticles may be embedded.

Synchronous fluorescence determination of ciprofloxacin in the pharmaceutical formulation and human serum based on the perturbed luminescence of rare-earth ions

Energy Technology Data Exchange (ETDEWEB)

Tong Changlun, E-mail: cltong@zju.edu.c [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029 (China); Zhuo Xiajun; Guo Yun; Fang Yueheng [Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310029 (China)

2010-11-15

A simple, rapid and sensitive synchronous fluorescence method was developed for the determination of ciprofloxacin (CPFX) in the pharmaceutical formulation and human serum. The results show that when Y{sup 3+} is added into the CPFX solution, the characteristic fluorescence of Y{sup 3+} is not emitted whereas the fluorescence intensity of CPFX is significantly enhanced. The synchronous fluorescence technology is employed in this method to directly determine trace amount of CPFX in human serum. A linear relationship between the fluorescence intensity and the CPFX concentration is obtained in the range of 1.0x10{sup -9} {approx}5.0x10{sup -6} mol L{sup -1}. The limit of detection (LOD) of this method attains as low as 2.0x10{sup -10} mol L{sup -1} (S/N=3). The selectivity of this method is also very good. Common metal ions, rare-earth ions and some pharmaceuticals, which are usually used together with CPFX in the clinic, do not interfere with the determination of CPFX under general conditions.

Continuous imaging of a single neutral atom in a variant magneto-optical trap

International Nuclear Information System (INIS)

Xia Tian; Zhou Shuyu; Chen Peng; Li Lin; Hong Tao; Wang Yuzhu

2010-01-01

We demonstrate continuous imaging of a single 87 Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device (EMCCD) camera and realize a one-dimensional micro-optical trap array with a Dammann grating. We adopt several methods to reduce the noise in the fluorescence signal we obtain with the EMCCD. Step jumping characteristics of the fluorescence demonstrate capturing and losing of individual atoms. (authors)

Lasers probe the atomic nucleus

International Nuclear Information System (INIS)

Eastham, D.

1983-01-01

The role of lasers in nuclear physics research is discussed including nuclear structure experiments involving the measurement of isotope shifts and hyperfine splitting in atomic energy levels in unstable nuclei by resonance fluorescence spectroscopy and the ultra sensitive detection of isotopic element abundances. (U.K.)

Determination of acetylsalicylic acid and salicylic acid in foods, using HPLC with fluorescence detection.

NARCIS (Netherlands)

Venema, D.P.; Hollman, P.C.H.; Janssen, P.L.T.M.K.; Katan, M.B.

1996-01-01

We developed a specific and sensitive HPLC method with fluorescence detection for the determination of free acetylsalicylic acid, free salicylic acid, and free salicylic acid plus salicylic acid after alkaline hydrolysis (free-plus-bound) in foods. Acetylsalicylic acid was detected after postcolumn

Local structure analysis of Cu(In,Ga)Se{sub 2} by X-ray fluorescence holography

Energy Technology Data Exchange (ETDEWEB)

Shirakata, Sho; Kitamura, Yuma [Faculty of Engineering, Ehime University, Matsuyama 790-8577 (Japan); Happo, Naohisa [Graduate School of Information Sciences, Hiroshima City University, Hiroshima 731-3194 (Japan); Hosokawa, Shinya [Department of Physics, Kumamoto University, Kumamoto 860-8555 (Japan); Hayashi, Kouichi [Faculty of Engineering, Nagoya Institute of technology, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555 (Japan)

2017-06-15

X-ray Fluorescence Holography (XFH) study of Cu(In,Ga)Se{sub 2} single crystals has been performed using an inverse mode. Energies of incident X-ray are from 9.2 to 13.2 keV. The Cu-Kα X-ray fluorescence hologram has been constructed, and atomic images were reconstructed using Barton's algorithm. Dependence of fluorescent X-ray, either Cu or Ga, on the reconstructed atomic images of CuIn{sub 0.2}Ga{sub 0.8}Se{sub 2} was examined. The atomic image of CuIn{sub 0.2}Ga{sub 0.8}Se{sub 2} was compared with that of CuIn{sub 0.8}Ga{sub 0.2}Se{sub 2}. The reconstructed atomic images of the cation (Cu, Ga, and In) plane and that of the anion (Se) plane are discussed in terms of the alloy composition. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

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)