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Sample records for fluorescence spectrometry units

  1. Fiber optical assembly for fluorescence spectrometry

    Science.gov (United States)

    Carpenter, II, Robert W.; Rubenstein, Richard; Piltch, Martin; Gray, Perry

    2010-12-07

    A system for analyzing a sample for the presence of an analyte in a sample. The system includes a sample holder for containing the sample; an excitation source, such as a laser, and at least one linear array radially disposed about the sample holder. Radiation from the excitation source is directed to the sample, and the radiation induces fluorescent light in the sample. Each linear array includes a plurality of fused silica optical fibers that receive the fluorescent light and transmits a fluorescent light signal from the first end to an optical end port of the linear array. An end port assembly having a photo-detector is optically coupled to the optical end port. The photo-detector detects the fluorescent light signal and converts the fluorescent light signal into an electrical signal.

  2. Protein conformation in solution by three-dimensional fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    鄢远; 许金钩; 陈国珍

    1996-01-01

    The conformations of bovine serum albumin (USA) and egg albumin (EA) in solution and their conformation changes under different conditions were studied by using three-dimensional fluorescence spectrometry (TDFS) such as three-dimensional fluorescence (TDF) spectra and three-dimensional fluorescence polarization (TDFP) spectra with tryptophan residues in protein molecules as an intrinsic fluorescent probe. The results show that the microenvironment of tryptophan residues of protein molecules in various solutions can be directly indicated and TDFS is an effective tool for studying protein conformation in solution. Meantime, some valuable results were obtained.

  3. Fluorescence preselection of bioaerosol for single-particle mass spectrometry

    Science.gov (United States)

    Stowers, M. A.; van Wuijckhuijse, A. L.; Marijnissen, J. C. M.; Kientz, Ch. E.; Ciach, T.

    2006-11-01

    We have designed, constructed, and tested a system that preselects the biological fraction of airborne particles from the overall aerosol. The preselection is based on fluorescence emission excited by a continuous 266 nm laser beam. This beam is one of two cw beams used to measure the aerodynamic particle size of sampled particles. The intention in our system is that single particles, based on size and fluorescence emission, can be selected and further examined for chemical composition by mass spectrometry.

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

    OpenAIRE

    Marschner, K; Musil, S. (Stanislav); Dědina, J. (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 NaBH4 in a flow injection arrangement, was chosen as the model hydride. Analytical characteristics of both the atomizers (sensitivity, noise, limits of detection) were ...

  5. Study on Atomic Fluorescence Spectrometry Excited by Synchrotron Radiation

    Institute of Scientific and Technical Information of China (English)

    Jia-jia Guo; Wu-er Gan; Guo-bin Zhang; Qing-de Su

    2008-01-01

    A novel analysis approach using atomic fluorescence excited by synchrotron radiation is presented. A system for synchrotron radiation-atomic fluorescence spectrometry is developed, and experimental conditions such as flow rate, analyte acidity, concentration of pre-reducing and hydrogenation system are optimized. The proposed method is successfully applied to get an excitation spectrum of arsenic. Seven of ten primary spectral lines, four of which have never been reported by means of atomic fluorescence spectrometry, agree well with the existing reports. The other three are proposed for the first time. Excitation potentials and possible transitions are investigated. Especially for the prominent line at 234.99 nm, the mechanism of generation is discussed and a model of energy transition processes is proposed.

  6. Determination of beryllium by using X-ray fluorescence spectrometry.

    Science.gov (United States)

    Zawisza, Beata

    2008-03-01

    X-ray fluorescence spectrometry method is subject to certain difficulties and inconveniences for the elements having the atomic number 9 or less. These difficulties become progressively more severe as the atomic number decreases, and are quite serious for beryllium, which is practically indeterminable directly by XRF. Therefore, an indirect determination of beryllium that is based on the evaluation of cobalt in the precipitate is taken into consideration. In the thesis below, there is a description of a new, simple, and precise method by selective precipitation using hexamminecobalt(III) chloride and ammonium carbonate-EDTA solution as a complexing agent for the determining of a trace amount of beryllium using X-ray fluorescence spectrometry. The optimum conditions for [Co(NH(3))(6)][Be(2)(OH)(3)(CO(3))(2)(H(2)O)(2)].(3)H(2)O complex formation were studied. The complex was collected on the membrane filter, and the Co Kalpha line was measured by XRF. The method presents the advantages of the sample preparation and the elimination of the matrix effects due to the thin film obtained. The detection limit of the proposed method is 0.2 mg of beryllium. The method was successfully applied to beryllium determination in copper/ beryllium/cobalt alloys.

  7. Water analysis via portable X-ray fluorescence spectrometry

    Science.gov (United States)

    Pearson, Delaina; Chakraborty, Somsubhra; Duda, Bogdan; Li, Bin; Weindorf, David C.; Deb, Shovik; Brevik, Eric; Ray, D. P.

    2017-01-01

    Rapid, in-situ elemental water analysis would be an invaluable tool in studying polluted and/or salt-impacted waters. Analysis of water salinity has commonly used electrical conductance (EC); however, the identity of the elements responsible for the salinity are not revealed using EC. Several studies have established the viability of using portable X-ray fluorescence (PXRF) spectrometry for elemental data analysis of soil, sediment, and other matrices. However, the accuracy of PXRF is known to be affected while scanning moisture-laden soil samples. This study used PXRF elemental data in water samples to predict water EC. A total of 256 water samples, from 10 different countries were collected and analyzed via PXRF, inductively coupled plasma atomic emission spectroscopy (ICP-AES), and a digital salinity bridge. The PXRF detected some elements more effectively than others, but overall results indicated that PXRF can successfully predict water EC via quantifying Cl in water samples (validation R2 and RMSE of 0.77 and 0.95 log μS cm-1, respectively). The findings of this study elucidated the potential of PXRF for future analysis of pollutant and/or metal contaminated waters.

  8. X-ray fluorescence spectrometry and related techniques an introduction

    CERN Document Server

    Margui, Eva

    2013-01-01

    X-ray fluorescence spectrometry (XRF) is a well-established analytical technique for qualitative and quantitative elemental analysis of a wide variety of routine quality control and research samples. Among its many desirable features, it delivers true multi-element character analysis, acceptable speed and economy, easy of automation, and the capacity to analyze solid samples. This remarkable contribution to this field provides a comprehensive and up-to-date account of basic principles, recent developments, instrumentation, sample preparation procedures, and applications of XRF analysis. If you are a professional in materials science, analytic chemistry, or physics, you will benefit from not only the review of basics, but also the newly developed technologies with XRF. Those recent technological advances, including the design of low-power micro- focus tubes and novel X-ray optics and detectors, have made it possible to extend XRF to the analysis of low-Z elements and to obtain 2D or 3D information on a microme...

  9. Certification of reference materials by energy-dispersive x-ray fluorescence spectrometry?

    DEFF Research Database (Denmark)

    Christensen, Leif Højslet; Heydorn, Kaj

    1985-01-01

    This paper studies the precision and accuracy that can be achieved using energy-dispersive x-ray fluorescence spectrometry for the determination of total sulphur content in BCR 38 Fly Ash issued by the European Community Bureau of Reference....

  10. Saturation of Energy Levels in Analytical Atomic Fluorescence Spectrometry. II. Experimental.

    Science.gov (United States)

    1981-01-30

    RESEARCH Contract N14-76-C-0838 Task Ao. NR 051-622 TECHNICAL REPORT NO. 34 SATURATION OF ENERGY LEVELS IN ANALYTICAL ATOMIC FLUORESCENCE SPECTROMETRY II...an assumption which is valid only if the daral o’l of 111, cxcilIatio n pulse is mucl ) longer than the fluorescence life- time of the tjaii!,ition

  11. 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}.

  12. Fluorescence preselection of bioaerosol for single-particle mass spectrometry

    OpenAIRE

    Stowers, M.A.; van Wuijckhuijse, A.L.; Marijnissen, J.C.M.; Kientz, C.E.; Ciach, T.

    2006-01-01

    We have designed, constructed, and tested a system that preselects the biological fraction of airborne particles from the overall aerosol. The preselection is based on fluorescence emission excited by a continuous 266 nm laser beam. This beam is one of two cw beams used to measure the aerodynamic particle size of sampled particles. The intention in our system is that single particles, based on size and fluorescence emission, can be selected and further examined for chemical composition by mas...

  13. Fluorescent lamp unit with magnetic field generating means

    Science.gov (United States)

    Grossman, M.W.; George, W.A.

    1989-08-08

    A fluorescent lamp unit having a magnetic field generating means for improving the performance of the fluorescent lamp is disclosed. In a preferred embodiment the fluorescent lamp comprises four longitudinally extending leg portions disposed in substantially quadrangular columnar array and joined by three generally U-shaped portions disposed in different planes. In another embodiment of the invention the magnetic field generating means comprises a plurality of permanent magnets secured together to form a single columnar structure disposed within a centrally located region defined by the shape of lamp envelope. 4 figs.

  14. Fluorescence preselection of bioaerosol for single-particle mass spectrometry

    NARCIS (Netherlands)

    Stowers, M.A.; Van Wuijckhuijse, A.L.; Marijnissen, J.C.M.; Kientz, C.E.; Ciach, T.

    2006-01-01

    We have designed, constructed, and tested a system that preselects the biological fraction of airborne particles from the overall aerosol. The preselection is based on fluorescence emission excited by a continuous 266 nm laser beam. This beam is one of two cw beams used to measure the aerodynamic pa

  15. Interaction of Tannin with Bovine Serum Albumin by Fluorescence Spectrometry

    CERN Document Server

    Dong-Il, Kim; Kye-Ryong, Sin

    2016-01-01

    Interaction between tannin and bovine serum albumin (BSA) was examined by the fluorescent quenching. The process of elimination between BSA and tannin was the one of a stationary state, and the coupling coefficient was one. The working strength between the tannin and the beef serum was hydrophobic one.

  16. Theory of analytical curves in atomic fluorescence flame spectrometry

    NARCIS (Netherlands)

    Hooymayers, H.P.

    1968-01-01

    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 bro

  17. Determination of thorium by fluorescent x-ray spectrometry

    Science.gov (United States)

    Adler, I.; Axelrod, J.M.

    1955-01-01

    A fluorescent x-ray spectrographic method for the determination of thoria in rock samples uses thallium as an internal standard. Measurements are made with a two-channel spectrometer equipped with quartz (d = 1.817 A.) analyzing crystals. Particle-size effects are minimized by grinding the sample components with a mixture of silicon carbide and aluminum and then briquetting. Analyses of 17 samples showed that for the 16 samples containing over 0.7% thoria the average error, based on chemical results, is 4.7% and the maximum error, 9.5%. Because of limitations of instrumentation, 0.2% thoria is considered the lower limit of detection. An analysis can be made in about an hour.

  18. Method for detecting binding events using micro-X-ray fluorescence spectrometry

    Science.gov (United States)

    Warner, Benjamin P.; Havrilla, George J.; Mann, Grace

    2010-12-28

    Method for detecting binding events using micro-X-ray fluorescence spectrometry. Receptors are exposed to at least one potential binder and arrayed on a substrate support. Each member of the array is exposed to X-ray radiation. The magnitude of a detectable X-ray fluorescence signal for at least one element can be used to determine whether a binding event between a binder and a receptor has occurred, and can provide information related to the extent of binding between the binder and receptor.

  19. Analysis of stainless steel samples by energy dispersive X-ray fluorescence (EDXRF) spectrometry

    Indian Academy of Sciences (India)

    M K Tiwari; A K Singh; K J S Sawhney

    2001-12-01

    A simple method for the analysis of stainless steel samples is presented which is based on radioisotope excited energy dispersive X-ray fluorescence (EDXRF) spectrometry and does not require any type-standards. Both absorption and enhancement effects have been taken into account in the fundamental parameter method for quantitative analysis and an iterative approach is followed for calculation of concentrations in steel samples. Non-linear least square fitting (NL-LSF) procedures have been used to determine accurately the fluorescent peak intensities. The method has been tested by analysing several CRM standard reference samples and 304 and 316 steel samples assuming as unknown. The EDXRF results have also been compared with the results of analysis of same samples by vacuum emission spark spectrometry (VES). Obtained values for concentration in steel samples match quite well with their certified values.

  20. Fluorescence and mass spectrometry studies of meta-tetra(hydroxyphenyl)chlorin photoproducts.

    Science.gov (United States)

    Kasselouri, A; Bourdon, O; Demore, D; Blais, J C; Prognon, P; Bourg-Heckly, G; Blais, J

    1999-09-01

    The meta-tetra(hydroxyphenyl)chlorin (m-THPC), a second-generation sensitizer used in photodynamic therapy (PDT), is currently under clinical trial. In vivo fluorometry provides direct evidence that photobleaching processes are induced at the tumor site during PDT. Photoproduct formation has thus to be taken into account to fully understand PDT treatment. A preliminary step is to determine the fluorescence characteristics of photoproducts formed in solution. Solutions of m-THPC irradiated at 514 nm have been separated by HPLC using absorption and fluorescence detection. Six main photoproducts have been isolated. According to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) results, five fluorescent photoproducts emitting at 652 nm have been attributed to three mono-, one di- and one tri-hydroxy derivatives (m/z 697, 713 and 729, respectively). Fluorescence characteristics of mono-hydroxy forms were found to be similar to those of m-THPC, whereas fluorescence yields in di- and tri-hydroxy derivatives were very low. Another product, corresponding to a MALDI-TOF MS main signal at m/z 542, showed an absorption spectrum maximum at 522 nm while a weak fluorescence was detected at 480 nm. The loss of the Soret band suggests that this photoproduct results from the opening of the reduced pyrrole ring. The part played by each of these products in the photobleaching phenomenon of m-THPC is discussed.

  1. Study of the distribution of actinides in human tissues using synchrotron radiation micro X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Vergucht, Eva; Samber, Bjoern de; Izmer, Andrei; Vekemans, Bart; Vincze, Laszlo; Vanhaecke, Frank [Ghent Univ. (Belgium). Dept. of Analytical Chemistry; Appel, Karen [DESY-Photo Science, Hamburg (Germany); Tolmachev, Sergei [Washington State Univ., Richland WA (United States). College of Pharmacy

    2015-02-15

    This study aims at evaluating the capabilities of synchrotron radiation micro X-ray fluorescence spectrometry (SR micro-XRF) for qualitative and semi-quantitative elemental mapping of the distribution of actinides in human tissues originating from individuals with documented occupational exposure. The investigated lymph node tissues were provided by the United States Transuranium and Uranium Registries (USTUR) and were analyzed following appropriate sample pre-treatment. Semi-quantitative results were obtained via calibration by external standards and demonstrated that the uranium concentration level in the detected actinide hot spots reaches more than 100 μg/g. For the plutonium hot spots, concentration levels up to 31 μg/g were found. As illustrated by this case study on these unique samples, SR micro-XRF has a high potential for this type of elemental bio-imaging owing to its high sensitivity, high spatial resolution, and non-destructive character.

  2. Spectral Interferences Manganese (Mn) - Europium (Eu) Lines in X-Ray Fluorescence Spectrometry Spectrum

    Science.gov (United States)

    Tanc, Beril; Kaya, Mustafa; Gumus, Lokman; Kumral, Mustafa

    2016-04-01

    X-ray fluorescence (XRF) spectrometry is widely used for quantitative and semi quantitative analysis of many major, minor and trace elements in geological samples. Some advantages of the XRF method are; non-destructive sample preparation, applicability for powder, solid, paste and liquid samples and simple spectrum that are independent from chemical state. On the other hand, there are some disadvantages of the XRF methods such as poor sensitivity for low atomic number elements, matrix effect (physical matrix effects, such as fine versus course grain materials, may impact XRF performance) and interference effect (the spectral lines of elements may overlap distorting results for one or more elements). Especially, spectral interferences are very significant factors for accurate results. In this study, semi-quantitative analyzed manganese (II) oxide (MnO, 99.99%) was examined. Samples were pelleted and analyzed with XRF spectrometry (Bruker S8 Tiger). Unexpected peaks were obtained at the side of the major Mn peaks. Although sample does not contain Eu element, in results 0,3% Eu2O3 was observed. These result can occur high concentration of MnO and proximity of Mn and Eu lines. It can be eliminated by using correction equation or Mn concentration can confirm with other methods (such as Atomic absorption spectroscopy). Keywords: Spectral Interferences; Manganese (Mn); Europium (Eu); X-Ray Fluorescence Spectrometry Spectrum.

  3. Elemental analysis of various biomass solid fractions in biorefineries by X-ray fluorescence spectrometry

    DEFF Research Database (Denmark)

    Le, Duy Michael; Sorensen, Hanne R.; Meyer, Anne S.

    2017-01-01

    Elemental analysis by X-ray fluorescence spectrometry (XRF) of solid samples from a biorefinery process was performed to study the behaviour of mineral elements in a process involving hydrothermal pretreatment of biomass (wheat straw, corn stover, sugarcane bagasse, palm oil empty fruit bunches......, poplar) followed by enzymatic hydrolysis and fermentation. For all the different biomasses, the biorefinery process concentrated silicon, aluminium, and calcium in the solid fraction, while potassium and magnesium were solubilised in the process and removed from the solid fraction. Sodium concentrations...

  4. Determination of metals in lubricating oils by X-ray fluorescence spectrometry.

    Science.gov (United States)

    Pouzar, M; Cernohorský, T; Krejcová, A

    2001-06-21

    The determination of common wear metals, namely iron, chromium, copper, zinc and lead, in a wide range of lubricating oil samples was investigated for the use of a low-cost, wavelength-dispersive X-ray fluorescence spectrometer. The procedure provided results in satisfactory agreement with inductively coupled plasma spectrometry used as reference method after microwave digestion of the samples in concentrated nitric acid. Statistical tests following extensive regression analyses of the data indicated that interelement effects were not statistically significant and that a simple linear regression was adequate for the calibration of individual metals.

  5. X-ray fluorescence spectrometry determination of open-hearth furnace slag by pressed powder briquetting

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A rapid analysis method of determining content of eight compounds of open-hearth furnace slag was developed using X-ray fluorescence spectrometry and pressed powder briquettes. Matrix effect was corrected using theoretical alpha coefficient. Grains-size effect was eliminated by optimized sample preparation technique parameters. Mineral effect was corrected with standard curve of specially made standard samples. The analysis results of TiO2, TFe, SiO2, MgO, Al2O3,CaO, MnO and P2O5 in slag samples showed that both precision and accuracy are comparable with that of chemical method.

  6. 100-OL-1 Operable Unit Field Portable X-Ray Fluorescence (XRF) Analyzer Pilot Study Plans

    Energy Technology Data Exchange (ETDEWEB)

    Bunn, Amoret L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fritz, Brad G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wellman, Dawn M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-07-01

    A pilot study is being conducted to support the approval of the Remedial Investigation/Feasibility Study (RI/FS) Work Plan to evaluate the 100-OL-1 Operable Unit (OU) pre-Hanford orchard lands. Based on comments received by the U.S. Environmental Protection Agency (EPA) and Washington State Department of Ecology, the pilot study will evaluate the use of field portable X-ray fluorescence (XRF) spectrometry measurements for evaluating lead and arsenic concentrations on the soil surface as an indicator of past use of lead arsenate pesticide residue in the OU. The work will be performed in the field during the summer of 2014, and assist in the planning for the characterization activities in the RI/FS.

  7. Implementation of the phenomenon of total reflection for total reflection X-Ray fluorescence spectrometry technique simulation

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Marcio H. dos; Anjos, Marcelino J. dos; Oliveira, Luis F. de, E-mail: marciohsantos2010@gmail.com, E-mail: bmarcelin@uerj.br, E-mail: clfolive@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Programa de Pos-Graduacao em Fisica; Albuquerque, Marcelo P. de, E-mail: mpalbuquer@gmail.com [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Atividades Tecnicas

    2015-07-01

    Within the scientific research field, X-ray fluorescence spectrometry is a basic technique for chemical analysis of materials, allowing recognition and study of the elemental nature of a particular sample. With this technique, the researcher uses different devices such as X-ray tubes, radioactive sources, monochromators crystals, capillaries, slits and waveguides, Si-Li detectors and scintillators. Furthermore, one can provide these elements with different arrangements in order to obtain a better configuration. One of the X-ray fluorescence spectrometry variants is the total reflection X-ray fluorescence spectrometry. It is based on the optical phenomenon of total reflection observed when a radiation beam impinges on a surface below a critical angle. Two important characteristics of this technique are to minimize the generation of background derived from the reflector support and allow the radiation interaction with very thin samples (thickness between 100 nm and 15 μm). The goal of the paper is to show the computational modeling of the physical phenomenon of total reflection that enables the implementation of total reflection X-ray fluorescence spectrometry technique through the simulator developed at Institute of Physics of the University of the State of Rio de Janeiro with parallel and distributed processing features. The simulator at hand is already available for implementation of energy dispersive X-ray fluorescence spectrometry. Through it, they are shown three simulations, each based on a particular apparatus: a set of reflectors, a capillary and a waveguide with lucite reflectors. (author)

  8. [Determination of major elements in soil from cancer village by X-ray fluorescence spectrometry].

    Science.gov (United States)

    Wei, Zhen-Lin; Li, He; Rui, Yu-Kui

    2008-11-01

    Many social problems arise from environmental pollution, cancer village is one of the many important problems caused by pollution. The authors selected a typical cancer village where 80-100 people died of cancer in the last five years, but there are only a total of 1 200 people in this village. The authors sampled soils from crops-planted areas and detected the major elements by X-ray fluorescence spectrometry. The results showed that the contents of SiO2, TiO2, Al2O3, Fe2O3, MnO, MgO, CaO, Na2O, K2O and P2O5 in soil of this village were 66.05%, 0.66%, 11.37%, 3.93%, 0.075%, 1.97%, 5.47%, 1.90%, 2.11% and 0.20% respectively; with the precision being +/- 0.20%, +/- 0.005%, +/- 0.10%, +/- 0.10%, +/- 0.005%, +/- 0.05%, +/- 0.04%, +/- 0.08%, +/- 0.02% and +/- 0.005% respectively, which showed that X-ray fluorescence spectrometry is a good method.

  9. Direct spectrometry: a new alternative for measuring the fluorescence of composite resins and dental tissues.

    Science.gov (United States)

    da Silva, Tm; de Oliveira, Hpm; Severino, D; Balducci, I; Huhtala, Mfrl; Gonçalves, Sep

    2014-01-01

    The aim of this study was to evaluate the fluorescence intensity of different composite resins and compare those values with the fluorescence intensity of dental tissues. Different composite resins were used to make 10 discs (2 mm in depth and 4 mm in diameter) of each brand, divided into groups: 1) Z (Filtek Z350, 3M ESPE), 2) ES (Esthet-X, Dentsply), 3) A (Amelogen Plus, Ultradent), 4) DVS (Durafill-VS, Heraeus Kulzer) with 2 mm composite resin for enamel (A2), 5) OES ([Esthet-X] opaque-OA [1 mm] + enamel-A2 [1 mm]); 6) ODVSI ([Charisma-Opal/Durafill-VSI], opaque-OM (1 mm) + translucent [1mm]), and 7) DVSI ([Durafill- VSI] translucent [2 mm]). Dental tissue specimens were obtained from human anterior teeth cut in a mesiodistal direction to obtain enamel, dentin, and enamel/dentin samples (2 mm). The fluorescence intensity of specimens was directly measured using an optic fiber associated with a spectrometer (Ocean Optics USB 4000) and recorded in graphic form (Origin 8.0 program). Data were submitted to statistical analysis using Dunnet, Tukey, and Kruskall-Wallis tests. Light absorption of the composite resins was obtained in a spectral range from 250 to 450 nm, and that of dental tissues was between 250 and 300 nm. All composite resins were excited at 398 nm and exhibited maximum emissions of around 485 nm. Fluorescence intensity values for all of the resins showed statistically significant differences (measured in arbitrary units [AUs]), with the exception of groups Z and DVS. Group DVSI had the highest fluorescence intensity values (13539 AU), followed by ODVS (10440 AU), DVS (10146 AU), ES (3946 AU), OES (3841 AU), A (3540 AU), and Z (1146 AU). The fluorescence intensity values for the composite resins differed statistically from those of dental tissues (E=1380 AU; D=6262 AU; E/D=3251 AU). The opacity interfered with fluorescence intensity, and group Z demonstrated fluorescence intensity values closest to that of tooth enamel. It is concluded that the

  10. Trace element distribution in human teeth by x-ray fluorescence spectrometry and multivariate statistical analysis

    CERN Document Server

    Oprea, Cristiana; Gustova, Marina V; Oprea, Ioan A; Buzguta, Violeta L

    2014-01-01

    X-ray fluorescence spectrometry (XRFS) was used as a multielement method of evaluation of individual whole human tooth or tooth tissues for their amounts of trace elements. Measurements were carried out on human enamel, dentine, and dental cementum, and some differences in tooth matrix composition were noted. In addition, the elemental concentrations determined in teeth from subjects of different ages, nutritional states, professions and gender, living under various environmental conditions and dietary habits, were included in a comparison by multivariate statistical analysis (MVSA) methods. By factor analysis it was established that inorganic components of human teeth varied consistently with their source in the tissue, with more in such tissue from females than in that from males, and more in tooth incisor than in tooth molar.

  11. Elemental Analysis of Variably Contaminated Cremains Using X-ray Fluorescence Spectrometry.

    Science.gov (United States)

    Gilpin, Megan; Christensen, Angi M

    2015-07-01

    Analyzing and identifying skeletal remains becomes increasingly difficult when remains have been cremated, especially in cases where the cremated material may have been intentionally contaminated with nonskeletal material. This study examined the potential of X-ray fluorescence spectrometry (XRF) to detect the presence of nonskeletal contaminants in samples of cremains. Eleven samples of cremains were variably combined with concrete mix and analyzed using XRF. Photon counts of elements in each sample were analyzed, and the coefficient of determination (R(2)) using unweighted linear regression as a function of percent cremains was calculated. Results showed that with changes in the proportion of skeletal material and contaminant, there were significant (R(2) > 0.90) changes in detected levels of phosphorus, potassium, zinc, aluminum, and sulfur. The use of XRF is concluded to be a valid approach in the identification of the presence of nonskeletal material in potentially contaminated cremains.

  12. Identifying metalloproteins through X-ray fluorescence mapping and mass spectrometry.

    Science.gov (United States)

    Raimunda, Daniel; Khare, Tripti; Giometti, Carol; Vogt, Stefan; Argüello, José M; Finney, Lydia

    2012-08-01

    Metals are critical and dynamic components of biochemistry. To understand their roles, we greatly need tools to identify the ligands that bind them within the complexity of natural systems. This work describes the development of methods that not only detect and distinguish metals, but also characterize the proteins that bind them. We describe an approach to expose, identify and quantify metalloproteins in complex mixtures by sequential non-denaturing 2D-gel electrophoresis (2D GE)/X-ray Fluorescence (XRF) and tandem mass spectrometry (MS/MS) in the same spot of a sample. We first apply the development of 2D GE/XRF to Shewanella oneidensis MR-1, a well-studied system, and verify our electrophoretic approach. Then, we identified a novel periplasmic zinc protein in Pseudomonas aeruginosa PAO1 through 2D GE/XRF followed by MS/MS. The identity and function of this protein was verified through a gene mutation experiment.

  13. X-ray fluorescence spectrometry applied to soil analysis; Espectrometria de fluorescencia de raios X aplicada as analises de solo

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, Vera Lucia Ribeiro; Sato, Ivone Mulako; Scapin Junior, Wilson Santo; Scapin, Marcos Antonio; Imakima, Kengo [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). E-mail: vsalvado@baitaca.ipen.br; imsato@net.ipen.br; kengo@sup.ipen.br

    1997-07-01

    This paper studies the X-ray fluorescence spectrometry applied to the soil analysis. A comparative study of the WD-XRFS and ED-XRFS techniques was carried out by using the following soil samples: SL-1, SOIL-7 and marine sediment SD-M-2/TM, from IAEA, and clay, JG-1a from Geological Survey of Japan (GSJ)

  14. Simple procedure for nutrient analysis of coffee plant with energy dispersive X-ray fluorescence spectrometry (EDXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Tezotto, Tiago; Favarin, Jose Laercio; Neto, Ana Paula; Azevedo, Ricardo Antunes, E-mail: tiago.tezotto@usp.br [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil); Gratao, Priscila Lupino [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP/ FCAV), Jaboticabal, SP (Brazil). Dept. de Biologia Aplicada a Agropecuaria; Mazzafera, Paulo [Universidade Estadual de Campinas (UNICAMP/IB), SP (Brazil). Dept. Biologia Vegetal

    2013-07-15

    Nutrient analysis is used to estimate nutrient content of crop plants to manage fertilizer application for sustained crop production. Direct solid analysis of agricultural and environmental samples by energy dispersive X-ray fluorescence spectrometry (EDXRF) was chosen as alternative technique to evaluate the simultaneous multielemental quantification of the most important essential elements in coffee (Coffea arabica L.) plants. Inductively coupled plasma atomic emission spectrometry and certified reference materials made from leaves were used to calibrate and check the trueness of EDXRF method for the determination of the concentration of several nutrients in coffee leaves and branches. Fluorescence spectrometry proved to be advantageous and presented low cost as loose powder samples could be used. Samples collected from a field experiment where coffee plants were treated with excess of Ni and Zn were used to verify the practical application of the method. Good relationships were achieved between certified values and data obtained by EDXRF, with recoveries ranging from 82 to 117 %.(author)

  15. X-ray fluorescence spectrometry analysis of mining related samples; Semiquantitative Roentgenfluoreszenzanalyse an bergbaurelevanten Proben

    Energy Technology Data Exchange (ETDEWEB)

    Leinert, P. [Lausitzer Analytik GmbH, Schwarze Pumpe (Germany)

    1997-09-01

    In many industries, especially in mining it is necessary to analyse occurring production process materials of unknown composition and of carious matrices in a short time. The determination of main components is very important, but also minor components and traces can be of interest for instance in pollution determination or the environmental investigation. The X-ray fluorescence spectrometry is a suitable method for fast analyse of a wide range of elements. This article gives a short and simplified description of the measuring principle and a overview about some international, German and ASTM-standards. It is described, how the standardless X-ray fluorescence analysis with the UniQuant system was used for a fast analysis of various mining related samples. The full english text is available from Lausitzer Analytik GmbH, An der Heide, 03139 Schwarze Pumpe/Germany. (orig.) [Deutsch] Anhand ausgewaehlter Beispiele aus dem Bergbaubereich konnte unter Verwendung von UniQuant die schnelle und preiswerte Analytik an Einzelproben verschiedenster Matrix demonstriert werden. Dabei wurden wegen der vielfach unbekannten etwaigen Zusammensetzung zunaechst nur die (vermuteten) Hauptkomponenten betrachtet. Die Ergebnisse belegen die Eignung der semiquantitativen Roentgenfluoreszenzanalyse zur Loesung der anstehenden Problemstellungen. Bei den genannten Vorteilen duerfen bestimmte Nachteile nicht unerwaehnt bleiben (ungenuegende Beruecksichtigung von Korngroessen- und Stoerelementeinfluessen, kurze Analysenzeit bedeutet kurzes Vermessen jeder einzelnen Elementlinie usw.). Oft koennen nur `Groessenordnungen` wiedergegeben werden, was besonders fuer nur in Spuren vorhandene Elemente zutrifft. (orig.)

  16. 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.

  17. [Determination of mercury in shark liver by cold atom fluorescence spectrometry after microwave dissolution].

    Science.gov (United States)

    Weng, Di

    2005-12-01

    The conditions for the determination of mercury in shark liver by cold atom fluorescence spectrometry (CAFS) with microwave dissolution were studied. After being dried completely, the method employed 2 mol x L(-1) HNO3-4 mol x L(-1) HCl as an oxidant, and with catalysis by V2O5, the samples were digested in a microwave oven. The mercury in absorption solution was reduced by SnCl2, and then was determined by CAFS at wavelength of 253.7 nm. 10% SnCl2 solution was used as a reductive agent for mercury. The linear range was 0-2.0 ng x mL(-1) mercury (r = 0.999 7). The detection limit was 0.05 ng x mL(-1), the relative standard deviation was 0.86%-2.22%, and the average recovery rate was 96.0%-108.5%. The method was suitable for the determination of mercury in shark liver.

  18. Novel Method for Indirect Determination of Iodine in Marine Products by Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    LU Jian-ping; TAN Fang-wei; TANG Qiong; JIANG Tian-cheng

    2013-01-01

    A method for the determination of iodine based upon compound H2HgI4,formed between I-and Hg2+ in nitric acid and extracted in methyl isobutyl ketone(MIBK),was developed via atomic fluorescence spectrometry(AFS).After the compound is reduced with potassium borohydrid(KBH4),the resultant mercury vapor was injected into the instrument and iodine was,therefore,indirectly determined.Experimental parameters such as the conditions of extraction reagents,aqueous phase acidity,elemental mercury diffusion temperature in a vial and other factors were investigated and optimized.Under the optimum experimental conditions,this method shows a detection limit of 0.038 μg/L iodine and a linear relationship between 0.04-20 μg/L.The method was applied to determining the iodine content in marine duck eggs,kelps,laver and Ganoderma lucidum spirulina,showing a relative standard deviation(RSD) of 2.15% and the recoveries in the range of 98.1%-102.5%.

  19. 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}.

  20. Determination of inorganic species of Sb and Te in cereals by hydride generation atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, Mariela N.M.; Cervera, Maria L.; Guardia, Miguel de la, E-mail: m.luisa.cervera@uv.e [University of Valencia, Valencia (Spain). Dept. of Analytical Chemistry

    2011-07-01

    A non-chromatographic fast, sensitive and easy method has been developed for the determination of Sb(III), Sb(V), Te(IV) and Te(VI) in cereal samples. The procedure is based on ultrasound assisted extraction and determination by hydride generation atomic fluorescence spectrometry (HG AFS). Preliminary studies were made in order to get the best extraction efficiency using 1 mol L{sup -1} phosphoric acid, 1 mol L{sup -1} nitric acid, aqua regia, 1 mol L{sup -1} sulfuric acid and 6 mol L{sup -1} hydrochloric acid. The extraction with aqua regia showed a clear interconversion of the species during the process, being H{sub 2}SO{sub 4} the best extractant with efficiencies greater than 90% from the total content of Sb and Te quantified previously and without species interconversion. This point was checked by recovery experiments at different spiked levels. The method provided limits of detection values from 0.1 to 0.5 ng g{sup -1} with relative standard deviation values from 5.4 to 9.2% of 10 independent analysis of samples containing few ng g-1 of Sb and Te species. (author)

  1. [Determination of 22 Elements in Herb Tea by X-Ray Fluorescence Spectrometry].

    Science.gov (United States)

    Li, Dan; Ge, Liang-quan; Wang, Guang-xi; Lai, Wan-chang; Zhai, Juan; Chen, Lu

    2015-07-01

    N, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Ba and Pb in herb tea were determined by X-ray fluorescence spectrometry with pressed powder pellets. The measuring conditions of target elements were investigated, including how to select its analytical line. In addition to Ba and Pb using L line, Kalpha line was selected for the rest. When the Compton scattered radiation of Rh Kalpha was measured, The X-ray tube voltage should be appropriately reduced, and the appropriate tube current should be selected. The matrix effect was corrected by empirical coefficient method and using scattered radiation (the Rayleigh scattered radiation of Rh Lalpha, the scattered background of 0.1876 nm wavelength position and the Compton scattered radiation of Rh Kalpha) as internal standard, and the spectral overlapping interference of some elements (N, Na, Ca, Ti, Mn, Sr and Ba) was corrected. For the target elements, the detection limit of this method was low, and its accuracy and precision were high. The results showed that there were abandon of elements in herb tea, of which different kinds had different components, even the same kind of herb tea with different source had some difference in element and content more or less, however, there was a lot of similarity between the features of its components. In a word, this method could achieve multi-element determination of herb tea, and it was simple in operation, low cost, rapid, and accurate.

  2. Geochemical analysis of marine sediments using fused glass disc by X-ray fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    XIA Ning; ZHANG Qin; YAO De; LI Guohui

    2008-01-01

    A method was developed for content determination of Na, Mg, Al, Si, P,S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Nb, Zr, Y, Sr, Rb, Ba, La and Ce etc. covering 26 major, minor, and trace elements in marine sediment samples using fused glass disc by X-ray Fluorescence spectrometry. Calibration was made using marine sediment certified reference materials and the synthetic standard samples prepared by mixing several marine sediments with stream sediment and carbonate standard samples in different proportions. The matrix effect was corrected using theoretical alpha coefficients, experience coefficients and the scattered radiation as the internal standard (for the trace elements). The accuracy of the method was evaluated by analysis of certified reference materials GBW07314, GBW07334 and GSMS6. The results are in good agreement with the certified values of the standards with RSD less than 2.60%, except for Y, Cr, Ga, Ce, La, Nb, Rb, and V with RSD less than 9.0% (n=12).

  3. [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.

  4. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Energy Technology Data Exchange (ETDEWEB)

    Angeli, Valeria [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); Biagi, Simona [National Research Council of Italy, C.N.R., Istituto per i Processi Chimico-Fisici - IPCF-UOS Pisa, Area di Ricerca, Via G. Moruzzi 1, 56124 Pisa (Italy); Ghimenti, Silvia [University of Pisa, Department of Chemistry and Industrial Chemistry, Via Risorgimento 35, 56126 Pisa (Italy); Onor, Massimo; 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); 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)

    2011-11-15

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H{sub 2} miniaturized flame after sodium borohydride reduction to Hg{sup 0}, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H{sub 2} microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10{sup -5} mol L{sup -1}), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L{sup -1} (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 {mu}mol L{sup -1} were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were

  5. Flow injection-chemical vapor generation atomic fluorescence spectrometry hyphenated system for organic mercury determination: A step forward

    Science.gov (United States)

    Angeli, Valeria; Biagi, Simona; Ghimenti, Silvia; Onor, Massimo; D'Ulivo, Alessandro; Bramanti, Emilia

    2011-11-01

    Monomethylmercury and ethylmercury were determined on line using flow injection-chemical vapor generation atomic fluorescence spectrometry without neither requiring a pre-treatment with chemical oxidants, nor UV/MW additional post column interface, nor organic solvents, nor complexing agents, such as cysteine. Inorganic mercury, monomethylmercury and ethylmercury were detected by atomic fluorescence spectrometry in an Ar/H 2 miniaturized flame after sodium borohydride reduction to Hg 0, monomethylmercury hydride and ethylmercury hydride, respectively. The effect of mercury complexing agent such as cysteine, ethylendiaminotetracetic acid and HCl with respect to water and Ar/H 2 microflame was investigated. The behavior of inorganic mercury, monomethylmercury and ethylmercury and their cysteine-complexes was also studied by continuous flow-chemical vapor generation atomic fluorescence spectrometry in order to characterize the reduction reaction with tetrahydroborate. When complexed with cysteine, inorganic mercury, monomethylmercury and ethylmercury cannot be separately quantified varying tetrahydroborate concentration due to a lack of selectivity, and their speciation requires a pre-separation stage (e.g. a chromatographic separation). If not complexed with cysteine, monomethylmercury and ethylmercury cannot be separated, as well, but their sum can be quantified separately with respect to inorganic mercury choosing a suitable concentration of tetrahydroborate (e.g. 10 - 5 mol L - 1 ), thus allowing the organic/inorganic mercury speciation. The detection limits of the flow injection-chemical vapor generation atomic fluorescence spectrometry method were about 45 nmol L - 1 (as mercury) for all the species considered, a relative standard deviation ranging between 1.8 and 2.9% and a linear dynamic range between 0.1 and 5 μmol L - 1 were obtained. Recoveries of monomethylmercury and ethylmercury with respect to inorganic mercury were never less than 91%. Flow injection

  6. [Using atomic fluorescence spectrometry to study the spatial distribution of As and Hg in orchard soils].

    Science.gov (United States)

    Zhao, Xi-Mei; Lü, Chun-Yan; Liu, Qing; Zhu, Xi-Cun

    2014-02-01

    Aqua regia digestion, double channels-atomic fluorescence spectrometry method was used to determine the concentrations of As and Hg in orchard soils of Qixia City - the main apple production area of Shandong province. Validate The detection limitation, accuracy and precision of the method were validated, the spatial distribution was analyzed, and the characteristics of As and Hg pollution in Qixia orchard soils were assessed. The results showed that the range of As concentration in Qixia soils is between 2.79 and 20.93 mg x kg(-1), the average concentration is 10.59 mg x kg(-1), the range of Hg concentration in Qixia soil is between 0.01 and 0.79 mg x kg(-1), the average concentration is 0.12 mg x kg(-1). The variation of As concentration in soils is small, whereas that of Hg concentration is large. Frequency distribution graphics of As and Hg showed that the concentration of As in soils is according with the normal distribution approximately and the concentrations are mostly between 7 and 15 mg x kg(-1), the concentration of Hg in soil isn't according with the normal distribution and the concentrations are mostly between 0.03 and 0.21 mg x kg(-1). The correlations between the concentrations of As or Hg in soils and the nutrient are not significant and there is no significant correlation even between As and Hg. Based on the environmental technical terms for green food production area, the As concentration in orchard soil of Qixia City is at clean level, but there are 4.76% of sample points with Hg pollution index exceeding 1, and this should be attracted the attention of the administrators.

  7. 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,…

  8. 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,…

  9. Portable X-ray Fluorescence Unit for Analyzing Crime Scenes

    Science.gov (United States)

    Visco, A.

    2003-12-01

    Goddard Space Flight Center and the National Institute of Justice have teamed up to apply NASA technology to the field of forensic science. NASA hardware that is under development for future planetary robotic missions, such as Mars exploration, is being engineered into a rugged, portable, non-destructive X-ray fluorescence system for identifying gunshot residue, blood, and semen at crime scenes. This project establishes the shielding requirements that will ensure that the exposure of a user to ionizing radiation is below the U.S. Nuclear Regulatory Commission's allowable limits, and also develops the benchtop model for testing the system in a controlled environment.

  10. Novel Fluorescent Chemosensors Based on Tryptophan Unit for Cu2+ and Fe3+ in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    CHENG Peng-fei; XU Kuo-xi; YAO Wen-yong; KONG Hua-jie; KOU Li; MA Xiao-dan; WANG Chao-jie

    2013-01-01

    We reported four fluorescent chemosensors containing tryptophan units.The fluorescence spectrum titration experiments suggest that chemosensors 1,2,3 and 4 are highly selective for Cu2+ and Fe3+ over Li+,Na+,K+,Co2+,Zn2+,Ni2+,Hg2+ and Cr3+ via forming complexes with Cu2+ or Fe3+,which is confirmed by dramatical quench of fluoreseence in aqueous solution at pH 7.4,thus making all the chemosensors suitable for Cu2+ and Fe3+ fluorescent sensors.

  11. Use of portable X-ray fluorescence spectrometry for environmental quality assessment of peri-urban agriculture.

    Science.gov (United States)

    Weindorf, David C; Zhu, Yuanda; Chakraborty, Somsubhra; Bakr, Noura; Huang, Biao

    2012-01-01

    Urban expansion into traditional agricultural lands has augmented the potential for heavy metal contamination of soils. This study examined the utility of field portable X-ray fluorescence (PXRF) spectrometry for evaluating the environmental quality of sugarcane fields near two industrial complexes in Louisiana, USA. Results indicated that PXRF provided quality results of heavy metal levels comparable to traditional laboratory analysis. When coupled with global positioning system technology, the use of PXRF allows for on-site interpolation of heavy metal levels in a matter of minutes. Field portable XRF was shown to be an effective tool for rapid assessment of heavy metals in soils of peri-urban agricultural areas.

  12. Total uncertainty budget calculation for the determination of mercury in incineration ash (BCR 176R) by atomic fluorescence spectrometry.

    Science.gov (United States)

    Tirez, Kristof; Beutels, Filip; Brusten, Wilfried; Noten, Bart; De Brucker, Nicole

    2002-11-01

    The mercury mass fraction has been determined by atomic fluorescence spectrometry (AFS) in the framework of the project "Certification of a reference material (trace elements in fly ash) in replacement of BCR CRM 176". Calculation of the uncertainty budget, as described in this manuscript, emphasizes a practical and realistic approach to estimation of uncertainty components on the basis of statistical assumptions. GUM Workbench software was used, and resulted in a mercury mass fraction of 1.58+/-0.11 mg kg(-1) (with coverage factor k=2.2, 95% probability) related to dry mass, submitted in the certification exercise. The calculated total uncertainty budget applies to analogous samples analyzed by this procedure.

  13. 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.

  14. Mass spectrometry based approach for identification and characterisation of fluorescent proteins from marine organisms

    DEFF Research Database (Denmark)

    Wojdyla, Katarzyna Iwona; Rogowska-Wrzesinska, Adelina; Wrzesinski, Krzysztof

    2011-01-01

    of the proteins in the fluorescent spots excised directly from unstained 2DE gels provides sequence information that might be sufficient to design degenerate primers for gene cloning. Identified fluorescent proteins are in agreement with the coral species determined by visual examination of the samples...

  15. Determination of cadmium in rice and water by tungsten coil electrothermal vaporization-atomic fluorescence spectrometry and tungsten coil electrothermal atomic absorption spectrometry after cloud point extraction

    Energy Technology Data Exchange (ETDEWEB)

    Wen Xiaodong [College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064 (China); Wu Peng [Analytical and Testing Center, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064 (China); Chen Li [College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064 (China); Hou Xiandeng, E-mail: houxd@scu.edu.cn [College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064 (China); Analytical and Testing Center, Sichuan University, 29 Wangjiang Road, Chengdu, Sichuan 610064 (China)

    2009-09-14

    In this work, the microsampling nature of tungsten coil electrothermal vaporization Ar/H{sub 2} flame atomic fluorescence spectrometry (W-coil ETV-AFS) as well as tungsten coil electrothermal atomic absorption spectrometry (W-coil ET-AAS) was used with cloud point extraction (CPE) for the ultrasensitive determination of cadmium in rice and water samples. When the temperature of the extraction system is higher than the cloud point temperature of the selected surfactant Triton X-114, the complex of cadmium with dithizone can be quantitatively extracted into the surfactant-rich phase and subsequently separated from the bulk aqueous phase by centrifugation. The main factors affecting the CPE, such as concentration of Triton X-114 and dithizone, pH, equilibration temperature and incubation time, were optimized for the best extract efficiency. Under the optimal conditions, the limits of detection for cadmium by W-coil ETV-AFS and W-coil ET-AAS were 0.01 and 0.03 {mu}g L{sup -1}, with sensitivity enhancement factors of 152 and 93, respectively. The proposed methods were applied to the determination of cadmium in certified reference rice and water samples with analytical results in good agreement with certified values.

  16. Comparison of a portable micro-X-ray fluorescence spectrometry with inductively coupled plasma atomic emission spectrometry for the ancient ceramics analysis

    Energy Technology Data Exchange (ETDEWEB)

    Papadopoulou, D.N. [Laboratory of Analytical Chemistry, Faculty of Chemistry, Aristotle University, GR-54124, Thessaloniki (Greece); Zachariadis, G.A. [Laboratory of Analytical Chemistry, Faculty of Chemistry, Aristotle University, GR-54124, Thessaloniki (Greece); Anthemidis, A.N. [Laboratory of Analytical Chemistry, Faculty of Chemistry, Aristotle University, GR-54124, Thessaloniki (Greece); Tsirliganis, N.C. [Archaeometry Laboratory, Cultural and Educational Technology Institute, Tsimiski 58, GR-67100, Xanthi (Greece); Stratis, J.A. [Laboratory of Analytical Chemistry, Faculty of Chemistry, Aristotle University, GR-54124, Thessaloniki (Greece)]. E-mail: jstratis@chem.auth.gr

    2004-12-01

    Two multielement instrumental methods of analysis, micro X-ray fluorescence spectrometry (micro-XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were applied for the analysis of 7th and 5th century B.C. ancient ceramic sherds in order to evaluate the above two methods and to assess the potential to use the current compact and portable micro-XRF instrument for the in situ analysis of ancient ceramics. The distinguishing factor of interest is that micro-XRF spectrometry offers the possibility of a nondestructive analysis, an aspect of primary importance in the compositional analysis of cultural objects. Micro-XRF measurements were performed firstly directly on the ceramic sherds with no special pretreatment apart from surface cleaning (micro-XRF on sherds) and secondly on pressed pellet disks which were prepared for each ceramic sherd (micro-XRF on pellet). For the ICP-AES determination of elements, test solutions were prepared by the application of a microwave-assisted decomposition procedure in closed high-pressure PFA vessels. Also, the standard reference material SARM 69 was used for the efficiency calibration of the micro-XRF instrument and was analysed by both methods. In order to verify the calibration, the standard reference materials NCS DC 73332 and SRM620 as well as the reference materials AWI-1 and PRI-1 were analysed by micro-XRF. Elemental concentrations determined by the three analytical procedures (ICP-AES, micro-XRF on sherds and micro-XRF on pellets) were statistically treated by correlation analysis and Student's t-test (at the 95% confidence level)

  17. Standard test methods for chemical analysis of ceramic whiteware materials using wavelength dispersive X-Ray fluorescence spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 These test methods cover the determination of ten major elements (SiO2, Al2O3, Fe2O3, MgO, CaO, Na2O, K2O, TiO2, P2O5, MnO, and LOI in ceramic whitewares clays and minerals using wavelength dispersive X-ray fluorescence spectrometry (WDXRF). The sample is first ignited, then fused with lithium tetraborate and the resultant glass disc is introduced into a wavelength dispersive X-ray spectrometer. The disc is irradiated with X-rays from an X-ray tube. X-ray photons emitted by the elements in the samples are counted and concentrations determined using previously prepared calibration standards. (1) In addition to 10 major elements, the method provides a gravimetric loss-on-ignition. Note 1—Much of the text of this test method is derived directly from Major element analysis by wavelength dispersive X-ray fluorescence spectrometry, included in Ref (1). 1.2 Interferences, with analysis by WDXRF, may result from mineralogical or other structural effects, line overlaps, and matrix effects. The structure of the...

  18. Evaluation of a new optic-enabled portable X-ray fluorescence spectrometry instrument for measuring toxic metals/metalloids in consumer goods and cultural products

    Science.gov (United States)

    Guimarães, Diana; Praamsma, Meredith L.; Parsons, Patrick J.

    2016-08-01

    X-ray fluorescence spectrometry (XRF) is a rapid, non-destructive multi-elemental analytical technique used for determining elemental contents ranging from percent down to the μg/g level. Although detection limits are much higher for XRF compared to other laboratory-based methods, such as inductively coupled plasma mass spectrometry (ICP-MS), ICP-optical emission spectrometry (OES) and atomic absorption spectrometry (AAS), its portability and ease of use make it a valuable tool, especially for field-based studies. A growing necessity to monitor human exposure to toxic metals and metalloids in consumer goods, cultural products, foods and other sample types while performing the analysis in situ has led to several important developments in portable XRF technology. In this study, a new portable XRF analyzer based on the use of doubly curved crystal optics (HD Mobile®) was evaluated for detecting toxic elements in foods, medicines, cosmetics and spices used in many Asian communities. Two models of the HD Mobile® (a pre-production and a final production unit) were investigated. Performance parameters including accuracy, precision and detection limits were characterized in a laboratory setting using certified reference materials (CRMs) and standard solutions. Bias estimates for key elements of public health significance such as As, Cd, Hg and Pb ranged from - 10% to 11% for the pre-production, and - 14% to 16% for the final production model. Five archived public health samples including herbal medicine products, ethnic spices and cosmetic products were analyzed using both XRF instruments. There was good agreement between the pre-production and final production models for the four key elements, such that the data were judged to be fit-for-purpose for the majority of samples analyzed. Detection of the four key elements of interest using the HD Mobile® was confirmed using archived samples for which ICP-OES data were available based on digested sample materials. The HD

  19. 原子荧光光谱法测定土壤中的砷含量%Determination of Arsenic in Soil by Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    刘燕芬

    2015-01-01

    通过结合具体的试验对运用原子荧光光谱法测定土壤中的砷含量进行了探讨,以期能为有关方面的需要提供有益的参考和借鉴。%In order to provide a useful reference for the relevant aspects of the arsenic content in soil by atomic fluorescence spectrometry, the method of atomic fluorescence spectrometry was used to determine the arsenic content in soil.

  20. Determination of trace chromium(VI) in drinking water using X-ray fluorescence spectrometry after solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Aranda, Pedro R.; Moyano, Susana; Martinez, Luis D.; De Vito, Irma E. [Universidad Nacional de San Luis, Facultad de Quimica, Bioquimica y Farmacia, Area de Quimica Analitica, Instituto de Quimica de San Luis (INQUISAL - CONICET), San Luis (Argentina)

    2010-09-15

    A new, simple, and selective method for preconcentration and determination of Cr(VI) in aqueous samples. After adsorption in ''batch mode'' on Aliquat 336-AC, determinations were made directly on the solid by X-ray fluorescence spectrometry, which had the advantage of not requiring the step of elution of the chromium retained. The enrichment factor was calculated considering that the tablets obtained from 10 mL solution of Cr(VI) (1000 {mu}g L{sup -1}) had a final thickness of 0.64 mm and a diameter of 16.7 mm; the volume deposited on the pellet was 0.14 cm{sup 3}. The preconcentration factor obtained was 71-fold, which was highly satisfactory for chromium trace analysis by XRF. Finally, the method was successfully applied to the determination of Cr(VI) in drinking water samples. (orig.)

  1. Photocatalytic oxidation of humic acid and its effect on haloacetic acid formation potential: a fluorescence spectrometry study.

    Science.gov (United States)

    Xiaoju, Yan; Ruiling, Bao; Shuili, Yu; Qiongfang, Li; Wei, Chen

    2012-01-01

    By fluorescence spectrometry method, molecular conformation changes of humic acid (HA) during the photocatalytic oxidation process were studied. Haloacetic acids formation potential (HAAFP) changes during the oxidation process were also measured. The results indicated that aromatic rings of HA decreased and conjugated double bonds were destroyed at the beginning of the process. Meanwhile, organic matter with large molecular weight decomposed into intermediates with smaller molecular weight, such as tryptophan and tyrosine. HA can be degraded almost completely, but not be mineralized thoroughly. Structures of the intermediates were changing during the oxidation process. Molecular structure transformation of HA led to the fluctuation tendency of the HAAFP changes during the photocatalytic oxidation process. HAAFP increased to 1.22 times that in raw water after 30 min of ultraviolet (UV) radiation, and decreased to 0.66 times that in raw water after 60 min of photocatalytic oxidation.

  2. Comparison of the quantitative results corrected by fundamental parameter method and difference calibration specimens in X-ray fluorescence spectrometry

    Science.gov (United States)

    Han, X. Y.; Zhuo, S. J.; Shen, R. X.; Wang, P. L.; Ji, A.

    2006-01-01

    Three kinds of standard specimens, including low-alloy steels (Japanese iron and steel CRM), glass from NIST and Chinese geological reference materials were analyzed by wavelength dispersive X-ray fluorescence spectrometry as unknown samples. The fundamental parameter method was used to correct the matrix effect and different specimens including pure element specimens and type specimens were employed as calibration samples. The quantitative results were compared in order to study the influence of calibration samples on the accuracy of quantitative results. The study showed that the fundamental parameter method could correct the matrix effects very well and relatively accurate quantitative results could be obtained, corrected by simple specimens, in case of type calibration specimens’ absence.

  3. Analysis of pre-Islamic ceramics from the Kur River Basin (Fars, Iran) using handheld X-ray fluorescence spectrometry

    Science.gov (United States)

    Pincé, Possum; Vekemans, Bart; Vandenabeele, Peter; Haerinck, Ernie; Overlaet, Bruno

    2016-09-01

    A large number of painted pre-Islamic ceramics from the Kur River Basin (Fars province, Iran) was collected on surveys and excavations conducted by the late Prof. L. Vanden Berghe (Ghent University, Belgium) during the 1950s. Handheld X-ray fluorescence spectrometry was undertaken on a selection of these ceramics to evaluate the applicability of the technique to study the fabric of these ceramics and the pigments used for decoration. The aim is to obtain elemental data, from which information about raw materials, manufacturing techniques and exchange systems can be extracted. A total of 26 sherds was analyzed dating from the Neolithic to the Late Bronze Age and belonging to different sites and styles. Five compositional groups could be identified in the dataset. These elemental groups differ from the groups obtained by the macroscopic study and are related to the production process and/or the provenance of the primary materials.

  4. Analytical capabilities of total reflection X-ray fluorescence spectrometry for silver nanoparticles determination in soil adsorption studies

    Science.gov (United States)

    Torrent, Laura; Iglesias, Mònica; Hidalgo, Manuela; Marguí, Eva

    2016-12-01

    In recent years, the production of silver nanoparticles (AgNPs) has grown due to their antibacterial properties. This fact enhances the release of these particles into the environment, especially in soils that are the major sink. To better understand adsorption processes in soils, usually batch kinetic studies are carried out. In this context, we tested the possibilities of using total reflection X-ray fluorescence spectrometry (TXRF) to monitor the silver content in soil adsorption kinetic studies. It was found that the lower limit of detection for Ag (through Ag-Kα detection) in aqueous solutions was around 37 μg·L- 1, which was suitable to carry out this kind of studies. Moreover, the direct analysis of Ag adsorbed onto soil after the kinetic studies was investigated. In this case, the limit of detection for Ag was around 1.7 mg·kg- 1. All TXRF results were compared with those obtained by inductively coupled plasma optic emission spectrometry and good agreement was found. The batch adsorption tests performed showed that 98% of polyvinylpyrrolidone coated AgNPs were retained on the tested soils in < 6 h.

  5. Screening analysis of biodiesel feedstock using UV-vis, NIR and synchronous fluorescence spectrometries and the successive projections algorithm.

    Science.gov (United States)

    Insausti, Matías; Gomes, Adriano A; Cruz, Fernanda V; Pistonesi, Marcelo F; Araujo, Mario C U; Galvão, Roberto K H; Pereira, Claudete F; Band, Beatriz S F

    2012-08-15

    This paper investigates the use of UV-vis, near infrared (NIR) and synchronous fluorescence (SF) spectrometries coupled with multivariate classification methods to discriminate biodiesel samples with respect to the base oil employed in their production. More specifically, the present work extends previous studies by investigating the discrimination of corn-based biodiesel from two other biodiesel types (sunflower and soybean). Two classification methods are compared, namely full-spectrum SIMCA (soft independent modelling of class analogies) and SPA-LDA (linear discriminant analysis with variables selected by the successive projections algorithm). Regardless of the spectrometric technique employed, full-spectrum SIMCA did not provide an appropriate discrimination of the three biodiesel types. In contrast, all samples were correctly classified on the basis of a reduced number of wavelengths selected by SPA-LDA. It can be concluded that UV-vis, NIR and SF spectrometries can be successfully employed to discriminate corn-based biodiesel from the two other biodiesel types, but wavelength selection by SPA-LDA is key to the proper separation of the classes. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Determination of lead in wine by hydride generation atomic fluorescence spectrometry in the presence of hexacyanoferrate(III).

    Science.gov (United States)

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

    2007-06-01

    A rapid, accurate, and precise method is described for the determination of Pb in wine using continuous-flow hydride generation atomic fluorescence spectrometry (CF-HGAFS). Sample pretreatment consists of ten-fold dilution of wine followed by direct plumbane generation in the presence of 0.1 mol L(-1) HCl and 1% m/v K(3)[Fe(CN)(6)] with 1% m/v NaBH(4) as reducing agent. An aqueous standard calibration curve is recommended for Pb quantification in wine sample. The method provides a limit of detection and a limit of quantification of 0.3 microg L(-1) and 1 microg L(-1), respectively. The relative standard deviation varies between 2-6% (within-run) and 4-11% (between-run) at 3-30 microg L(-1) Pb levels in wine. Good agreement has been demonstrated between results obtained by CF-HGAFS and direct electrothermal atomic absorption spectrometry in analyses of red and white wines within the concentration range of 9.2-25.8 microg L(-1) Pb.

  7. Study of on-line analysis using energy dispersive X-ray fluorescence spectrometry for controlling lanthanum and neodymium extraction

    Energy Technology Data Exchange (ETDEWEB)

    Wenli, Li; Ascenzo, G.D`; Curini, R. [Department of Chemistry, University of Rome `La Sapienza`, Rome (Italy); Gasparini, G.M.; Casarci, M.; Mattia, B.; Traverso, D.M.; Bellisario, F. [ENEA, CRE Casaccia INN-NUMA (Italy)

    1998-05-04

    Many rare-earth extraction processes require frequent control over separation process quality. Ideally, an analysis method for this type should be simple, rapid and reliable. Energy dispersive X-ray fluorescence (EDXRF) spectrometry, due to its relative simplicity of instrumentation, speed of analysis, and non-destructive nature, is well suited to this on-line analysis application. In particular, since the radioisotope energy dispersive XRF method eliminates the need to transport samples to a laboratory which houses the X-ray spectrometry, it is most commonly used for on-line analysis of extraction systems. The present paper describes an attempt to type the radioisotope source {sup 241}Am XRF on-line analysis arrangement coupled with a personal computer for controlling a lanthanum and neodymium separation process. From the HpGe detector (high-purity germanium) response, a continuous spectral signal is observed during loading of the feed samples. The separation process using countercurrent extraction consists of a 16-stage laboratory mixer-settler, a switching valve, and a pumping system. The performance of this control system is illustrated by extracting La, Nd acidic solutions with 100% tributyl phosphate

  8. 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...

  9. Analytical procedure for characterization of medieval wall-paintings by X-ray fluorescence spectrometry, laser ablation inductively coupled plasma mass spectrometry and Raman spectroscopy

    Science.gov (United States)

    Syta, Olga; Rozum, Karol; Choińska, Marta; Zielińska, Dobrochna; Żukowska, Grażyna Zofia; Kijowska, Agnieszka; Wagner, Barbara

    2014-11-01

    Analytical procedure for the comprehensive chemical characterization of samples from medieval Nubian wall-paintings by means of portable X-ray fluorescence (pXRF), laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and Raman spectroscopy (RS) was proposed in this work. The procedure was used for elemental and molecular investigations of samples from archeological excavations in Nubia (modern southern Egypt and northern Sudan). Numerous remains of churches with painted decorations dated back to the 7th-14th century were excavated in the region of medieval kingdoms of Nubia but many aspects of this art and its technology are still unknown. Samples from the selected archeological sites (Faras, Old Dongola and Banganarti) were analyzed in the form of transfers (n = 26), small fragments collected during the excavations (n = 35) and cross sections (n = 15). XRF was used to collect data about elemental composition, LA-ICPMS allowed mapping of selected elements, while RS was used to get the molecular information about the samples. The preliminary results indicated the usefulness of the proposed analytical procedure for distinguishing the substances, from both the surface and sub-surface domains of the wall-paintings. The possibility to identify raw materials from the wall-paintings will be used in the further systematic, archeometric studies devoted to the detailed comparison of various historic Nubian centers.

  10. Fluorescent Oligonucleotides Containing a 2-Ethynylfluorene-or 2-Ethynylfluorenone-labeled 2'-Deoxyguanosine Unit: Fluorescence Changes upon Duplex Formation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Ji; Hwang, Gil Tae [Kyungpook National University, Daegu (Korea, Republic of)

    2016-08-15

    Two new DNA probes bearing a fluorescent deoxyguanosine unit labeled with 2-ethynylfluorene (G{sup FL} )or 2-ethynylfluorenone (G{sup FO}) were synthesized and examined for their efficiency as quencher-free linear beacon probes. Oligodeoxynucleotides (ODNs) containing a G{sup FL} or G{sup FO} unit exhibit low thermal selectivity and few distinctive fluorescence changes upon duplex formation due to the syn conformation about the glycosidic bond. An exciplex emission was observed when the G{sup FL} unit of ODNs bearing adenine flanking bases was positioned opposite to the adenine nucleobases.

  11. Application of Fluorescence Spectrometry With Multivariate Calibration to the Enantiomeric Recognition of Fluoxetine in Pharmaceutical Preparations.

    Science.gov (United States)

    Poláček, Roman; Májek, Pavel; Hroboňová, Katarína; Sádecká, Jana

    2016-04-01

    Fluoxetine is the most prescribed antidepressant chiral drug worldwide. Its enantiomers have a different duration of serotonin inhibition. A novel simple and rapid method for determination of the enantiomeric composition of fluoxetine in pharmaceutical pills is presented. Specifically, emission, excitation, and synchronous fluorescence techniques were employed to obtain the spectral data, which with multivariate calibration methods, namely, principal component regression (PCR) and partial least square (PLS), were investigated. The chiral recognition of fluoxetine enantiomers in the presence of β-cyclodextrin was based on diastereomeric complexes. The results of the multivariate calibration modeling indicated good prediction abilities. The obtained results for tablets were compared with those from chiral HPLC and no significant differences are shown by Fisher's (F) test and Student's t-test. The smallest residuals between reference or nominal values and predicted values were achieved by multivariate calibration of synchronous fluorescence spectral data. This conclusion is supported by calculated values of the figure of merit.

  12. Arsenic species analysis in porewaters and sediments using hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    LIAO Meng-xia; DENG Tian-long

    2006-01-01

    It was observed that the atomic fluorescence emission due to As(Ⅴ) could has a 10% to 40% of fluorescence emission signal during the determination of As(Ⅲ) in the mixture of As(Ⅲ) and As(Ⅴ). Besides, interferes from heavy metals such as Pb(Ⅱ),Cu(Ⅱ) can cause severe increase of the signals as compared to the insignificant effects caused by Cd(Ⅱ), Zn(Ⅱ), Mn(Ⅱ) and Fe(Ⅲ). On the basis of further studies, the masking agent of 8-hydroxyquinoline was used as an efficient agent to eliminate interference of As(Ⅴ)emission and the heavy metal of Cu2+ and Pb2+ in the measurements of arsenic species. After a series standard additions and CRM researches, a sensitive and interference-free analytical procedure was developed for the speciation of arsenic in samples ofporewaters and sediments in Poyang Lake, China.

  13. Determination of quinolone residues in shrimp using liquid chromatography with fluorescence detection and residue confirmation by mass spectrometry.

    Science.gov (United States)

    Karbiwnyk, Christine M; Carr, Lori E; Turnipseed, Sherri B; Andersen, Wendy C; Miller, Keith E

    2007-07-23

    The quinolones, oxolinic acid (OXO), flumequine (FLU), and nalidixic acid (NAL), are antibacterial drugs effective against gram-negative bacteria. Quinolones are used in both human and veterinary medicine, but are currently not approved by the U.S. Food and Drug Administration for use in food fish. A liquid chromatography-fluorescence (LC-FL) method was developed to determine OXO, FLU, and NAL residues in shrimp. An additional liquid chromatography-mass spectrometry (LC-MS(n)) method was created to confirm these residues using the same sample extract. Samples were prepared with a simple ethyl acetate extraction followed by solvent exchange into 0.2% formic acid and cleaned-up with hexane. Reverse phase chromatography was used to separate the three compounds in both procedures. For the LC-FL determinative method, fluorescence emission was monitored at 369 nm with excitation at 327 nm. With electrospray ionization, the three most abundant ions from the MS3 product ion spectrum were used to identify OXO, FLU, and NAL in the confirmation procedure. Shrimp samples fortified at levels ranging from 7.5 to 100 ng g(-1) were used to validate both methods.

  14. Direct determination of mercury in white vinegar by matrix assisted photochemical vapor generation atomic fluorescence spectrometry detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu Qingyang, E-mail: liuqingyang0807@yahoo.com.c [Beijing Center for Physical and Chemical Analysis, Beijing 100089 (China)

    2010-07-15

    This paper proposes the use of photochemical vapor generation with acetic acid as sample introduction for the direct determination of ultra-trace mercury in white vinegars by atomic fluorescence spectrometry. Under ultraviolet irradiation, the sample matrix (acetic acid) can reduce mercury ion to atomic mercury Hg{sup 0}, which is swept by argon gas into an atomic fluorescence spectrometer for subsequent analytical measurements. The effects of several factors such as the concentration of acetic acid, irradiation time, the flow rate of the carrier gas and matrix effects were discussed and optimized to give detection limits of 0.08 ng mL{sup -1} for mercury. Using the experimental conditions established during the optimization (3% v/v acetic acid, 30 s irradiation time and 20 W mercury lamp), the precision levels, expressed as relative standard deviation, were 4.6% (one day) and 7.8% (inter-day) for mercury (n = 9). Addition/recovery tests for evaluation of the accuracy were in the range of 92-98% for mercury. The method was also validated by analysis of vinegar samples without detectable amount of Hg spiked with aqueous standard reference materials (GBW(E) 080392 and GBW(E) 080393). The results were also compared with those obtained by acid digestion procedure and determination of mercury by ICP-MS. There was no significant difference between the results obtained by the two methods based on a t-test (at 95% confidence level).

  15. Direct determination of mercury in white vinegar by matrix assisted photochemical vapor generation atomic fluorescence spectrometry detection

    Science.gov (United States)

    Liu, Qingyang

    2010-07-01

    This paper proposes the use of photochemical vapor generation with acetic acid as sample introduction for the direct determination of ultra-trace mercury in white vinegars by atomic fluorescence spectrometry. Under ultraviolet irradiation, the sample matrix (acetic acid) can reduce mercury ion to atomic mercury Hg 0, which is swept by argon gas into an atomic fluorescence spectrometer for subsequent analytical measurements. The effects of several factors such as the concentration of acetic acid, irradiation time, the flow rate of the carrier gas and matrix effects were discussed and optimized to give detection limits of 0.08 ng mL -1 for mercury. Using the experimental conditions established during the optimization (3% v/v acetic acid, 30 s irradiation time and 20 W mercury lamp), the precision levels, expressed as relative standard deviation, were 4.6% (one day) and 7.8% (inter-day) for mercury ( n = 9). Addition/recovery tests for evaluation of the accuracy were in the range of 92-98% for mercury. The method was also validated by analysis of vinegar samples without detectable amount of Hg spiked with aqueous standard reference materials (GBW(E) 080392 and GBW(E) 080393). The results were also compared with those obtained by acid digestion procedure and determination of mercury by ICP-MS. There was no significant difference between the results obtained by the two methods based on a t-test (at 95% confidence level).

  16. Interaction of europium and nickel with calcite studied by Rutherford Backscattering Spectrometry and Time-Resolved Laser Fluorescence Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, A. [Agence Nationale pour la gestion des Déchets RAdioactifs, 1-7 rue J. Monnet, Parc de la Croix Blanche, 92298 Châtenay-Malabry Cedex (France); Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Pipon, Y., E-mail: pipon@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69 622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); CEA/DEN, Saclay, 91191 Gif sur Yvette (France); Lomenech, C. [Université de Nice Sophia Antipolis, Ecosystèmes Côtiers Marins et Réponses aux Stress (ECOMERS), 28 avenue Valrose, 06108 Nice Cedex 2 (France); Jordan, N. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69 622 Villeurbanne Cedex (France); Barkleit, A. [Helmholtz Zentrum Dresden Rossendorf (HZDR), Institute of Resource Ecology (IRE) (Germany); and others

    2014-08-01

    This study aims at elucidating the mechanisms regulating the interaction of Eu and Ni with calcite (CaCO{sub 3}). Calcite powders or single crystals (some mm sized) were put into contact with Eu or Ni solutions at concentrations ranging from 10{sup −3} to 10{sup −5} mol L{sup −1} for Eu and 10{sup −3} mol L{sup −1} for Ni. The sorption durations ranged from 1 week to 1 month. Rutherford Backscattering Spectrometry (RBS) well adapted to discriminate incorporation processes such as: (i) adsorption or co precipitation at the mineral surfaces or, (ii) incorporation into the mineral structure (through diffusion for instance), has been carried out. Moreover, using the fluorescence properties of europium, the results have been compared to those obtained by Time-Resolved Laser Fluorescence Spectroscopy (TRLFS) on calcite powders. For the single crystals, complementary SEM observations of the mineral surfaces at low voltage were also performed. Results showed that Ni accumulates at the calcite surface whereas Eu is also incorporated at a greater depth. Eu seems therefore to be incorporated into two different states in calcite: (i) heterogeneous surface accumulation and (ii) incorporation at depth greater than 160 nm after 1 month of sorption. Ni was found to accumulate at the surface of calcite without incorporation.

  17. On the demands on imaging spectrometry for the monitoring of global vegetation fluorescence from space

    Science.gov (United States)

    Kraft, S.; Del Bello, U.; Drusch, M.; Gabriele, A.; Harnisch, B.; Moreno, J.

    2013-09-01

    Vegetation fluorescence when measured from space contributes only a tiny fraction of the signal coming on top of the reflected radiance by the Earth surface and the atmosphere. As a consequence, imaging spectrometers have to provide sufficient throughput and radiometric accuracy to enable accurate global monitoring of the daily to seasonal variations of the Earth's vegetation breath, which is particularly challenging if ground resolutions of a few hundred meters are targeted. Since fluorescence retrieval algorithms have to make corrections for atmospheric effects, it is necessary to provide sufficient spectral resolution, so that signal alterations due to the main parameters such as surface pressure, atmospheric temperature profile, vertical distribution of aerosols concentration, and water vapour content can be accurately modelled. ESA's Earth Explorer 8 candidate mission FLEX carries a Fluorescence Imaging Spectrometer (FLORIS), which has been designed and optimised to enable such measurement. The spectrometer will measure in a spectral range between 500 and 780 nm and provide high spectral resolution of 0.3 nm in particular at the Oxygen-A and -B bands. It will also cover the photochemical reflection features between 500 and 600 nm, the Chlorophyll absorption region between 600 and 677 nm, and the red-edge in the region of 697 to 755 nm. FLEX will fly in formation with Sentinel-3 in order to further enhance the spectral coverage from measurements made by the Sentinel-3 instruments OLCI and SLSTR, particularly for cloud screening and proper characterization of the atmospheric status.

  18. Fluorescence Spectrometry of the Interaction of Multi-Walled Carbon Nanotubes with Catalase

    Science.gov (United States)

    Fan, Y.; Li, Y.; Cai, H.; Li, J.; Miao, J.; Fu, D.; Yang, Q.

    2014-11-01

    The interaction of multi-walled carbon nanotubes (MWCNTs) with catalase is investigated using fluorescence and circular dichroism spectroscopic techniques. The results of the fluorescence experiments suggest that MWCNTs quench the intrinsic fluorescence of catalase via a static quenching mechanism. The circular dichroism spectral results reveal the unfolding of catalase with a significant decrease in the α-helix content in the presence of MWCNTs, which indicates that the conformation of catalase is changed in the binding process, thereby remarkably decreasing its activity. The binding constants and the number of binding sites of the MWCNT to the catalase are calculated at different temperatures. The thermodynamic parameters, such as the changes in free energy (ΔG), enthalpy (ΔH), and entropy (ΔS), are calculated using thermodynamic equations. The fact that all negative values of ΔG, ΔH, and ΔS are obtained suggests that the interaction of the MWCNTs with catalase is spontaneous, and that hydrogen bonding and van der Waals interactions play an important role in the binding process.

  19. Two-step laser excited atomic fluorescence spectrometry determination of mercury

    Science.gov (United States)

    Resto, W.; Badini, R. G.; Smith, B. W.; Stevenson, C. L.; Winefordner, J. D.

    1993-04-01

    A novel method for the determination of mercury by laser excited atomic fluorescence with electrothermal atomization (LEAFS-ETA) has been developed. The experimental set-up consisted of a dual dye-laser system pumped with a XeCl excimer laser operated at 10 Hz, and an electrothermal atomizer with platform atomization. The atomization program allowed time for the injection of Pd (as a matrix modifier) and used a drying step at 110°C and an atomization step at 1200°C. The collection is made at 90° using a pierced mirror, an achromat lens and a long-pass filter. The monochromator is fitted with a 1P28 PMT. The signal is processed by using a boxcar and an analog to digital interface. The excitation scheme is a two-step process, with λ 1 = 253.7 nm and λ 2 = 435.8 nm. Direct fluorescence is observed at 546.1 nm. The limit of detection (LOD) obtained is 90 fg (9 pptr with 10 μ1 injection). The linear dynamic range (LDR) is five orders of magnitude and is limited by the non-linearity of the co-operative processes occurring at higher concentrations. In order to extend the LDR to higher amounts of mercury, indirect fluorescence is collected with the less sensitive line at 407.8 nm, allowing concentrations of 1 ppm and up to be measured, extending the LDR of the technique to at least seven orders of magnitude.

  20. An improved reagent for determination of aliphatic amines with fluorescence and online atmospheric chemical ionization-mass spectrometry identification.

    Science.gov (United States)

    You, Jinmao; Song, Cuihua; Yan, Tao; Sun, Zhiwei; Li, Yulin; Suo, Yourui

    2010-01-18

    An improved reagent named 2-[2-(dibenzocarbazole)-ethoxy] ethyl chloroformate (DBCEC-Cl) for the determination of aliphatic amines by high-performance liquid chromatography (HPLC) with fluorescence detection and post-column online atmospheric chemical ionization-mass spectrometry (APCI-MS) identification has been developed. DBCEC-Cl could easily and quickly label aliphatic amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+H](+) under APCI-MS in positive-ion mode. The ratios for fluorescence responses were I(DBCEC-amine)/I(BCEC-amine)=1.02-1.60; I(DBCEC-amine)/I(BCEOC-amine)=1.30-2.57; and I(DBCEC-amine)/I(FMOC-amine)=2.20-4.12 (here, I was relative fluorescence intensity). The ratios for MS responses were IC(DBCEC-amine)/IC(BCEC-amine)=4.16-29.31 and IC(DBCEC-amine)/IC(BCEOC-amine)=1.23-2.47 (Here, IC: APCI-MS ion current intensity). Detection limits calculated from 0.0244 pmol injection, at a signal-to-noise ratio of 3, were 0.3-3.0 fmol. The relative standard deviations for within-day determination (n=6) were 0.045-0.081% for retention time and 0.86-1.03% for peak area for the tested aliphatic amines. The mean intra- and inter-assay precision for all amine levels were 0.9991. Copyright 2009 Elsevier B.V. All rights reserved.

  1. An improved reagent for determination of aliphatic amines with fluorescence and online atmospheric chemical ionization-mass spectrometry identification

    Energy Technology Data Exchange (ETDEWEB)

    You Jinmao, E-mail: Jmyou6304@163.com [Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, 810001 (China) and Key Laboratory of Life-Organic Analysis, College of Chemistry Science, Qufu Normal University, Qufu Shandong, 273165 (China); Song Cuihua; Yan Tao [Key Laboratory of Life-Organic Analysis, College of Chemistry Science, Qufu Normal University, Qufu Shandong, 273165 (China); Sun Zhiwei [Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, 810001 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Li Yulin; Suo Yourui [Northwest Plateau Institute of Biology, Chinese Academy of Sciences, Xining, 810001 (China)

    2010-01-18

    An improved reagent named 2-[2-(dibenzocarbazole)-ethoxy] ethyl chloroformate (DBCEC-Cl) for the determination of aliphatic amines by high-performance liquid chromatography (HPLC) with fluorescence detection and post-column online atmospheric chemical ionization-mass spectrometry (APCI-MS) identification has been developed. DBCEC-Cl could easily and quickly label aliphatic amines. Derivatives were stable enough to be efficiently analyzed by HPLC and showed an intense protonated molecular ion corresponding m/z [M+H]{sup +} under APCI-MS in positive-ion mode. The ratios for fluorescence responses were I{sub DBCEC-amine}/I{sub BCEC-amine} = 1.02-1.60; I{sub DBCEC-amine}/I{sub BCEOC-amine} = 1.30-2.57; and I{sub DBCEC-amine}/I{sub FMOC-amine} = 2.20-4.12 (here, I was relative fluorescence intensity). The ratios for MS responses were IC{sub DBCEC-amine}/IC{sub BCEC-amine} = 4.16-29.31 and IC{sub DBCEC-amine}/IC{sub BCEOC-amine} = 1.23-2.47 (Here, IC: APCI-MS ion current intensity). Detection limits calculated from 0.0244 pmol injection, at a signal-to-noise ratio of 3, were 0.3-3.0 fmol. The relative standard deviations for within-day determination (n = 6) were 0.045-0.081% for retention time and 0.86-1.03% for peak area for the tested aliphatic amines. The mean intra- and inter-assay precision for all amine levels were <3.64% and 4.67%, respectively. The mean recoveries ranged from 96.9% to 104.7% with their standard deviations in the range of 1.80-2.70 (RSDs%). Excellent linear responses were observed with coefficients of >0.9991.

  2. Methylmercury in water samples at the pg/L level by online preconcentration liquid chromatography cold vapor-atomic fluorescence spectrometry

    Science.gov (United States)

    Brombach, Christoph-Cornelius; Chen, Bin; Corns, Warren T.; Feldmann, Jörg; Krupp, Eva M.

    2015-03-01

    Ultra-traces of methylmercury at the sub-ppt level can be magnified in the foodweb and is of concern. In environmental monitoring a routine robust analytical method is needed to determine methylmercury in water. The development of an analytical method for ultra-trace speciation analysis of methylmercury (MeHg) in water samples is described. The approach is based on HPLC-CV-AFS with on-line preconcentration of water samples up to 200 mL, resulting in a detection limit of 40 pg/L (ppq) for MeHg, expressed as Hg. The unit consists of an optimized preconcentration column filled with a sulfur-based sorption material, on which mercury species are preconcentrated and subsequently eluted, separated and detected via HPLC-CV-AFS (high performance liquid chromatography-cold vapor atomic fluorescence spectrometry). During the method development a type of adsorbate material, the pH dependence, the sample load rate and the carry-over were investigated using breakthrough experiments. The method shows broad pH stability in the range of pH 0 to 7, without the need for buffer addition and shows limited matrix effects so that MeHg is quantitatively recovered from sewage, river and seawater directly in the acidified samples without sample preparation.

  3. Analytical procedure for characterization of medieval wall-paintings by X-ray fluorescence spectrometry, laser ablation inductively coupled plasma mass spectrometry and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Syta, Olga; Rozum, Karol; Choińska, Marta [Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland); Zielińska, Dobrochna [Institute of Archaeology, University of Warsaw, Krakowskie Przedmieście 26/28, 00-927 Warsaw (Poland); Żukowska, Grażyna Zofia [Chemical Faculty, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw (Poland); Kijowska, Agnieszka [National Museum in Warsaw, Aleje Jerozolimskie 3, 00-495 Warsaw (Poland); Wagner, Barbara, E-mail: barbog@chem.uw.edu.pl [Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw (Poland)

    2014-11-01

    Analytical procedure for the comprehensive chemical characterization of samples from medieval Nubian wall-paintings by means of portable X-ray fluorescence (pXRF), laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) and Raman spectroscopy (RS) was proposed in this work. The procedure was used for elemental and molecular investigations of samples from archeological excavations in Nubia (modern southern Egypt and northern Sudan). Numerous remains of churches with painted decorations dated back to the 7th–14th century were excavated in the region of medieval kingdoms of Nubia but many aspects of this art and its technology are still unknown. Samples from the selected archeological sites (Faras, Old Dongola and Banganarti) were analyzed in the form of transfers (n = 26), small fragments collected during the excavations (n = 35) and cross sections (n = 15). XRF was used to collect data about elemental composition, LA-ICPMS allowed mapping of selected elements, while RS was used to get the molecular information about the samples. The preliminary results indicated the usefulness of the proposed analytical procedure for distinguishing the substances, from both the surface and sub-surface domains of the wall-paintings. The possibility to identify raw materials from the wall-paintings will be used in the further systematic, archeometric studies devoted to the detailed comparison of various historic Nubian centers. - Highlights: • The analytical procedure for examination of unique wall paintings was proposed. • Identification of pigments and supporting layers of wall-paintings was obtained. • Heterogeneous samples were mapped with the use of LA-ICPMS. • Anatase in the sub-surface regions of samples was detected by Raman spectroscopy.

  4. [Analysis of 14 elements for Jinhua bergamot by X-ray fluorescence spectrometry and elemental analyser].

    Science.gov (United States)

    Wang, Zhi-gang; Yu, Hong-mei

    2012-01-01

    The content of the elements C, H, O and N in Jinhua bergamot was analysed by using Vario III elemental analyser, the bergamot sample was scanned by using X-ray fluorescence spectrometer with PW2400 wavelength dispersion, and the content of the elements Mg, Al, P, S, Cl, K, Ca, Mn, Fe and Sr was analysed by using IQ+ analytical method. It turned out that the result is more ideal if the content of the elements C, H, O and N is processed as fix phase, and the analytical result is more ideal if, to prevent the sample skin from coming off, the sample is wrapped with mylar film with the film coefficient adjusted.

  5. Synthesis, Characterization, Electrical Conductivity and Fluorescence Properties of Polyimine Bearing Phenylacetylene Units.

    Science.gov (United States)

    Şenol, Dilek; Kolcu, Feyza; Kaya, İsmet

    2016-09-01

    In this study, a Schiff base was synthesized by the condensation reaction of 4-bromobenzaldehyde and 4-aminophenol. Then, phenylacetylene substituted Schiff base monomer (IPA) was obtained by HBr elimination reaction of IPA with phenylacetylene through Sonogashira reaction. IPA was polymerized via chemical oxidative polycondensation reaction. FT-IR and NMR measurements were used for the structural analyses of the synthesized substances. Fluorescence and UV-Vis analyses were carried out for optical characterization. Electrochemical characteristics, electrical conductivities and thermal properties were determined using cyclic voltammetry (CV), four-point probe conductometer, TG-DTA and DSC methods. The main purpose of the present study was to investigate the effects of phenylacetylene bearing units on the properties of conjugated aromatic polyimines. The spectral analysis signified a green light emission behavior when irradiated at different wavelengths. Combined with fluorescent behavior and good thermal stability, the electrical conductivity was found to be very crucial for π-conjugated polymer.

  6. [Rapid determination of major and trace elements in the salt lake clay minerals by X-ray fluorescence spectrometry].

    Science.gov (United States)

    Wang, Xiao-Huan; Meng, Qing-Fen; Dong, Ya-Ping; Chen, Mei-Da; Li, Wu

    2010-03-01

    A rapid multi-element analysis method for clay mineral samples was described. This method utilized a polarized wave-length dispersive X-ray fluorescence spectrometer--Axios PW4400, which had a maximum tube power of 4 000 watts. The method was developed for the determination of As, Mn, Co, Cu, Cr, Dy, Ga, Mo, P, Pb, Rb, S, Sr, Ni, ,Cs, Ta, Th, Ti, U, V, Y, Zn, Zr, MgO, K2O, Na2O, CaO, Fe2O3, Al2O3, SiO2 and so on. Thirty elements in clay mineral species were measured by X-ray fluorescence spectrometry with pressed powder pellets. Spectral interferences, in particular the indirect interferences of each element, were studied. A method to distinguish the interference between each other periodic elements in element periodic table was put forward. The measuring conditions and existence were mainly investigated, and the selected background position as well as corrected spectral overlap for the trace elements were also discussed. It was found that the indirect spectral overlap line was the same important as direct spectral overlap line. Due to inducing the effect of indirect spectral overlap, some elements jlike Bi, Sn, W which do not need analysis were also added to the elements channel. The relative standard deviation (RSD) was in the range of 0.01% to 5.45% except three elements Mo, Cs and Ta. The detection limits, precisions and accuracies for most elements using this method can meet the requirements of sample analysis in clay mineral species.

  7. Direct determination of trace elements in boron nitride powders by slurry sampling total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Amberger, Martin A.; Hoeltig, Michael [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, D-20146 Hamburg (Germany); Broekaert, Jose A.C., E-mail: jose.broekaert@chemie.uni-hamburg.d [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, D-20146 Hamburg (Germany)

    2010-02-15

    The use of slurry sampling total reflection X-ray fluorescence spectrometry (SlS-TXRF) for the direct determination of Ca, Cr, Cu, Fe, Mn and Ti in four boron nitride powders has been described. Measurements of the zeta potential showed that slurries with good stabilities can be obtained by the addition of polyethylenimine (PEI) at a concentration of 0.1 wt.% and by adjusting the pH at 4. For the optimization of the concentration of boron nitride in the slurries the net line intensities and the signal to background ratios were determined for the trace elements Ca and Ti as well as for the internal standard element Ga in the case of concentrations of boron nitride ranging from 1 to 30 mg mL{sup -1}. As a compromise with respect to high net line intensities and high signal to background ratios, concentrations of 5 mg mL{sup -1} of boron nitride were found suitable and were used for all further measurements. The limits of detection of SlS-TXRF for the boron nitride powders were found to range from 0.062 to 1.6 mug g{sup -1} for Cu and Ca, respectively. Herewith, they are higher than those obtained in solid sampling and slurry sampling graphite furnace atomic absorption spectrometry (SoS-GFAAS, SlS-GFAAS) as well as those of solid sampling electrothermal evaporation inductively coupled plasma optical emission spectrometry (SoS-ETV-ICP-OES). For Ca and Fe as well as for Cu and Fe, however, they were found to be lower than for GFAAS and for ICP-OES subsequent to wet chemical digestion, respectively. The universal applicability of SlS-TXRF to the analysis of samples with a wide variety of matrices could be demonstrated by the analysis of certified reference materials such as SiC, Al{sub 2}O{sub 3}, powdered bovine liver and borate ore with a single calibration. The correlation coefficients of the plots for the values found for Ca, Fe and Ti by SlS-TXRF in the boron nitride powders as well as in the before mentioned samples versus the reference values for the respective

  8. Toward chromium speciation in solids using wavelength dispersive X-ray fluorescence spectrometry Cr Kβ lines.

    Science.gov (United States)

    Malherbe, J; Claverie, F

    2013-04-22

    The determination of chromium speciation in solid samples is critical for environmental and industrial purposes. Several analytical methods exist to perform such a determination either directly in solid state or liquid state after an extraction step, each of them having some limitations. In this study, the use of a high-resolution wavelength-dispersive X-ray fluorescence spectrometer to determine and quantify chromium species is investigated by looking at the differences in the Kβ transition profiles between Cr(0), Cr(III) and Cr(VI) compounds. Three different approaches were tested and compared to determine the Cr(VI) fraction of known mixtures: relative height and peak fitting using calibration mixtures, partial least square regression (PLS) of pure compounds, and principal component regression (PCR) of pure compounds. The accuracy of these methods was found to be about the same with an average relative error in the range of 15%. However, PLS and PCR can be easily implemented in an automated way contrary to peak fitting which can be sometimes perceived as analyst-dependant. Another advantage of using PLS and PCR is that information concerning the other oxidation states present in the sample can be retrieved. Finally, PLS and the peak height approach can be used up to 0.5% total chromium which make the XRF an alternative technique to X-ray induced photoelectron spectroscopy (XPS) for chromium speciation in solid state.

  9. High temperature monitoring of silicon carbide ceramics by confocal energy dispersive X-ray fluorescence spectrometry

    Science.gov (United States)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi

    2016-04-01

    In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios (ICo/IRa) and effective atomic numbers (Zeff) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between ICo/IRa and Zeff was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Zeff differing from each other by only 0.01. The linear relationship between the variation of Zeff and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔCC, ΔCSi, and ΔCO were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

  10. Speciation analysis of arsenic compounds in seafood by ion chromatography-atomic fluorescence spectrometry

    Science.gov (United States)

    Han, Tingting; Ji, Hongwei; Li, Huixin; Cui, He; Song, Tian; Duan, Xiaojuan; Zhu, Qianlin; Cai, Feng; Zhang, Li

    2017-06-01

    Ion chromatography-ultra violet-hydride generation-Atomic Florescence Spectrometry was applied to detect 5 arsenic species in seafoods. The arsenic species studied include arsenobetaine (AsB), arsenite (As(III)), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), and arsenate (As(V)), which were extracted from samples using 2% formic acid. Gradient elution using 33 mmol L-1 CH3COONH4 and 15 mmol L-1 Na2CO3 with 10 mL CH3CH2OH at pH 8.4 allowed the chromatographic separation of all the species on a Hamilton PRP-X100 anion-exchange column in less than 8 min. In this study, an ultrasound extraction method was used to extract arsenic species from seafood. The extraction efficiency was good and the recoveries from spiked samples were in the range of 72.6%-109%; the precision between sample replicates was higher than 3.6% for all determinations. The detection limits were 3.543 μg L-1 for AsB, 0.426 μg L-1 for As(III), 0.216 μg L-1 for DMA, 0.211 μg L-1 for MMA, and 0.709 μg L-1 for As(V), and the linear coefficients were greater than 0.999. We also developed an application of this method for the determination of arsenic species in bonito, Euphausia superba, and Enteromorpha with satisfactory results. Therefore, it was confirmed that this method was appropriate for the detection of arsenic species in seafood.

  11. [High current microsecond pulsed hollow cathode lamp excited ionic fluorescence spectrometry of alkaline earth elements in inductively coupled plasma with a Fassel-torch].

    Science.gov (United States)

    Zhang, Shao-Yu; Gong, Zhen-Bin; Huang, Ben-Li

    2006-02-01

    High current microsecond pulsed hollow cathode lamp (HCMP-HCL) excited ionic fluorescence spectrometry (IFS) of alkaline earth elements in inductively coupled plasma (ICP) with a Fassel-torch has been investigated. In wide condition ranges only IFS was observed, whilst atomic fluorescence spectrometry (AFS) was not detectable. More intense ionic fluorescence signal was observed at lower observation heights and at lower incident RF powers. Without introduction of any reduction organic gases into the ICP, the limit of detection (LOD, 3sigma) of Ba was improved by 50-fold over that of a conventional pulsed (CP) HCL with the Baird sleeve-extended torch. For Ca and Sr, the LODs by HCMP-HCL-ICP-IFS and CP-HCL-ICP-AFS show no significant difference. Relative standard deviations were 0.6%-1.4% (0.1-0.2 microg x mL(-1), n = 10) for 5 ionic fluorescence lines. Preliminary studies showed that the intensity of ionic fluorescence could be depressed in the presence of K, Al and P.

  12. Development of an analytical method for antimony speciation in vegetables by HPLC-hydride generation-atomic fluorescence spectrometry.

    Science.gov (United States)

    Olivares, David; Bravo, Manuel; Feldmann, Jorg; Raab, Andrea; Neaman, Alexander; Quiroz, Waldo

    2012-01-01

    A new method for antimony speciation in terrestrial edible vegetables (spinach, onions, and carrots) was developed using HPLC with hydride generation-atomic fluorescence spectrometry. Mechanical agitation and ultrasound were tested as extraction techniques. Different extraction reagents were evaluated and optimal conditions were determined using experimental design methodology, where EDTA (10 mmol/L, pH 2.5) was selected because this chelate solution produced the highest extraction yield and exhibited the best compatibility with the mobile phase. The results demonstrated that EDTA prevents oxidation of Sb(III) to Sb(V) and maintains the stability of antimony species during the entire analytical process. The LOD and precision (RSD values obtained) for Sb(V), Sb(III), and trimethyl Sb(V) were 0.08, 0.07, and 0.9 microg/L and 5.0, 5.2, and 4.7%, respectively, for a 100 microL sample volume. The application of this method to real samples allowed extraction of 50% of total antimony content from spinach, while antimony extracted from carrots and onion samples ranged between 50 and 60 and 54 and 70%, respectively. Only Sb(V) was detected in three roots (onion and spinach) that represented 60-70% of the total antimony in the extracts.

  13. Nondestructive determination of lead, cadmium, tin, antimony, and barium in ceramic glazes by radioisotope X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, D.L.; Cunningham, W.C. [Food and Drug Administration, Washington, DC (United States)

    1996-09-01

    Quantitation capabilities of radioisotope X-ray fluorescence spectrometry (RXRFS) for determining lead, cadmium, tin, antimony, and barium in ceramic glazes were investigated. Twenty-one air-dried glazes and 85 fired glazes on test tiles were analyzed by using {sup 109}Cd and {sup 57}Co excitation sources. Accurate Pb determinations, with limits of detection (LODs) of about 0.3 mg/cm{sup 2} for 5 min counting times, were achieved by using the 75 keV {Kappa}{sub {alpha}}{sub 1} X-ray photopeak and a Pb foil calibration procedure. Cd, Sn, Sb, and Ba concentrations were determined with LODs from about 0.5 to 1.5 mg/cm{sup 2}. For Pb and Ba, results obtained by using absorption corrections based only on element concentrations determined by RXRFS and an iterative approach led to analytical biases of {le}4% relative to results obtained by using corrections based on known total element compositions. Biases were more severe for Cd, Sn, and Sb because lower X-ray energies were involved and sensitivities varied as a function of matrix Pb content. Pb concentrations were above LODs (1.3-40 mg/cm{sup 2}) in 39 of 47 fired {open_quotes}food-safe{close_quotes} glazes and in 33 of the other 38 fired glazes (0.4-39 mg/cm{sup 2}). 15 refs., 9 figs., 9 tabs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Qingxiang, E-mail: zhouqx@cup.edu.cn [School of Chemistry and Environmental Sciences, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huaihe River Water Environment and Pollution Control, Ministry of Education, Xinxiang 453007 (China); State Laboratory of Petroleum Resource and Prospecting, College of Geosciences, China University of Petroleum Beijing, Beijing 102249 (China); Zhao, Na [State Laboratory of Petroleum Resource and Prospecting, College of Geosciences, China University of Petroleum Beijing, Beijing 102249 (China); Xie, Guohong [College of Resources and Environment, Henan Institute of Science and Technology, Xinxiang 453003 (China)

    2011-05-15

    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{sup -1} (r{sup 2} = 0.9990). The precision was 2.12% (RSD, n = 7) and the detection limit was 0.95 ng L{sup -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%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Potin-Gautier, M. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France); Pannier, F. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France)]. E-mail: Florence.pannier@univ-pau.fr; Quiroz, W. [Laboratoire de Chimie Analytique, BioInorganique et Environnement LCABIE (UMR CNRS 3054), Universite de Pau et des pays de l' Adour, 64000 Pau (France); Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile); Pinochet, H. [Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile); Gregori, I. de [Laboratorio de Quimica Analitica y Ambiental, Instituto de Quimica, Pontificia Universidad catolica de Valparaiso (Chile)

    2005-11-30

    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{sup -1} for Sb(III) and TMSbCl2 and 40 ng g{sup -1} for Sb(V) in sediment samples.

  16. Localization of iron in rice grain using synchrotron X-ray fluorescence microscopy and high resolution secondary ion mass spectrometry

    KAUST Repository

    Kyriacou, Bianca

    2014-03-01

    Cereal crops accumulate low levels of iron (Fe) of which only a small fraction (5-10%) is bioavailable in human diets. Extensive co-localization of Fe in outer grain tissues with phytic acid, a strong chelator of metal ions, results in the formation of insoluble complexes that cannot be digested by humans. Here we describe the use of synchrotron X-ray fluorescence microscopy (XFM) and high resolution secondary ion mass spectrometry (NanoSIMS) to map the distribution of Fe, zinc (Zn), phosphorus (P) and other elements in the aleurone and subaleurone layers of mature grain from wild-type and an Fe-enriched line of rice (Oryza sativa L.). The results obtained from both XFM and NanoSIMS indicated that most Fe was co-localized with P (indicative of phytic acid) in the aleurone layer but that a small amount of Fe, often present as "hotspots", extended further into the subaleurone and outer endosperm in a pattern that was not co-localized with P. We hypothesize that Fe in subaleurone and outer endosperm layers of rice grain could be bound to low molecular weight chelators such as nicotianamine and/or deoxymugineic acid. © 2014.

  17. [Discussion on diagenesis of Xilingang pluton-constrained by X-ray Fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy].

    Science.gov (United States)

    Tang, Yu-Kun; Chen, Guo-Neng; Zhang, Ke; Huang, Hai-Hua

    2013-05-01

    The results on Xilingang pluton, mainly consisting of red beds, granites containing numerous debris of red beds and granites, obtained by X-ray fluorescence spectroscopy, plasma mass spectrometry and Raman spectroscopy show: (1) Xilingang pluton from red beds, granites containing numerous debris of red beds to granites has obvious characteristics of decreasing silicon and alkali content, and rising ignition loss, dark mineral content and oxidation index; (2) Chondrite-normalized REE distribution curves and primitive mantle-normalized spider diagram for trace elements of redbed, granites containing numerous debris of red beds and granites have a good consistency, the distribution characteristics of elements are similar to Nanling transformation-type granite; (3) The value of Raman spectrogram characteristic peak of quartz crystal in Xilingang granite decreased from the center of quartz crystal, and FWHM is steady. According to the above, the authors believe that Xilingang granite formed was related to in-situ melting of red beds and underlying strata and magma consolidation. Volatile components were discharged continuously, and oxidation index decreased gradually in the melting process. In the process of diagenesis, the top of pluton tend to be an ongoing silicon and alkali increase, while TFeO and MgO continue to migrate to bottom, and crystallization environment is a relatively closed and steady system.

  18. Elemental concentration analysis in the brain of young and old Wistar rats by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Serpa, Renata F.B.; Jesus, Edgar F.O. de; Lopes, Ricardo T. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Nuclear Instrumentation Lab.]. E-mail: renata@lin.ufrj.br; Anjos, Marcelino J. dos [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.]. E-mail: marcelin@lin.ufrj.br; Carmo, Maria G.T. do [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Nutrition Inst.; Rocha, Monica S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Basics and Clinic Pharmacy; Moreira, Silvana [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Civil Engineering Dept.; Martinez, Ana M.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. of Histology and Embryology

    2007-07-01

    It is well known that aging is associated with neurobehavioral deficits. The aging process of human brain is characterized by progressive neuronal loss. Furthermore, certain brain areas are more vulnerable to neuronal degeneration than others, reflecting an altered resistance to stress of the tissue itself and/or the lack of adequate immunological defense mechanisms in these regions. About the elemental levels in the brain, it is known that the excess ou deficiency of some elements are toxic for human healthy, being also related to several neurodegenerative diseases. In this way, the main goal of this work was to determine the elemental concentration in the hippocampus of young and old male (n = 10) and female (n = 10) Wistar rats by total reflection X-ray fluorescence spectrometry with synchrotron radiation (SR-TXRF). These measurements were carried out at XRF beam line at Light Synchrotron Brazilian Laboratory, Campinas, Brazil. About the results, we could observe that Al, Fe, Cu, Zn and Br levels were higher in the hippocampus of the old female rats than the young ones. On the other hand, only Cu levels were higher in the hippocampus of the old male rats than the young ones. Therefore, the aging of the hippocampus of the female rats can be characterized by an accumulate for Al, Fe, Cu, Zn and Br. The excess in these elements levels are also associated with several neurodegenerative disorders, such as Alzheimer' disease, Parkinson's disease and Huntington's disease. (author)

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

    Science.gov (United States)

    Li, Shan; Wang, Mei; Zhong, Yizhou; Zhang, Zehua; Yang, Bingyi

    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.

  20. Determination of heavy metals in macrozoobenthos from the rivers Tisza and Szamos by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Woelfl, S. [Universidad Austral de Chile, Instituto de Zoologia, Casilla 567, Valdivia (Chile)]. E-mail: swoelfl@uach.cl; Mages, M. [Helmhotz Centre for Environmental Research (UFZ), Department of River Ecology, Brueckstrasse 3a, D-39114, Magdeburg (Germany); Ovari, M. [Ovari, M. Eoetvoes University, Department of Organic Chemistry, H-1117, Budapest, Pazmany P. stny. 1/a (Hungary); Geller, W. [Helmhotz Centre for Environmental Research (UFZ), Department of River Ecology, Brueckstrasse 3a, D-39114, Magdeburg (Germany)

    2006-11-15

    In 2000, accidents in the Romanian mining industry in key catchment areas led to heavy metal contamination of the Hungarian rivers Tisza and Szamos resulting in substantial heavy metal loads in several sediments of the upper river basins. This enhanced metal content might have been bioaccumulated in benthic organisms during the following years. Therefore, the aim of this study was to test, whether the zoobenthic fauna showed an enhanced metal content 3 years after the industrial accident. Macrozoobenthic insect larvae (chironomids) were sampled 100 m below and above the confluent site of the rivers Tisza and Szamos during summer 2003 and for comparison purpose also in the river Maros, a tributary of the Tisza river, during 2005. In order to determine their heavy metal content, single specimens were prepared and analysed by Total Reflection X-ray Fluorescence Spectrometry (TRXF) according to the modified dry method. Fe was much lower and Mn and Zn much higher concentrated in benthos from the more contaminated Szamos river compared to the Tisza and Maros rivers. In this sense, the benthic organisms reflected very well the enhanced metal concentrations in the contaminated rivers being suitable as bioindicators of metal contamination. However, the sediment bioaccumulation factor was low at all sampling sites indicating a low bioavailability of trace metals for benthic organisms.

  1. The analysis of thallium in geological materials by radiochemical neutron activation and x-ray fluorescence spectrometry: a comparison

    Energy Technology Data Exchange (ETDEWEB)

    McGoldrick, P.J.; Robinson, P. [Tasmania Univ., Sandy Bay, TAS (Australia)

    1993-12-31

    Carrier-based radiochemical neutron activation (RNAA) is a precise and accurate technique for the analysis of Tl in geological materials. For about a decade, until the mid-80s, a procedure modified from Keays et al. (1974) was used at the University of Melbourne to analyse for Tl in a wide variety of geological materials. Samples of powdered rock weighing several hundred milligrams each were irradiated in HIFAR for between 12 hours and 1 week, and subsequently fused with a sodium hydroxide - sodium peroxide mixture and several milligrams of inactive Tl carrier. Following acid digestion of the fusion mixture anion exchange resin was used to separate Tl from the major radioactive rock constituents. The Tl was then stripped from the resin and purified as thallium iodide and a yield measured gravimetrically. Activity from {sup 204}Tl (a {beta}-emitter with a 3 8 year half-life) was measured and Tl determined by reference to pure chemical standards irradiated and processed along with the unkowns. Detection limits for the longer irradiations were about one part per billion. Precision was monitored by repeat analyses of `internal standard` rocks and was estimated to be about five to ten percent (one standard deviation). On the other hand, X-ray fluorescence spectrometry (XRF) was seen as an excellent cost-effective alternative for thallium analysis in geological samples, down to 1 ppm. 6 refs. 1 tab., 1 fig.

  2. Determination of heavy metals in macrozoobenthos from the rivers Tisza and Szamos by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, S.; Mages, M.; Óvári, M.; Geller, W.

    2006-11-01

    In 2000, accidents in the Romanian mining industry in key catchment areas led to heavy metal contamination of the Hungarian rivers Tisza and Szamos resulting in substantial heavy metal loads in several sediments of the upper river basins. This enhanced metal content might have been bioaccumulated in benthic organisms during the following years. Therefore, the aim of this study was to test, whether the zoobenthic fauna showed an enhanced metal content 3 years after the industrial accident. Macrozoobenthic insect larvae (chironomids) were sampled 100 m below and above the confluent site of the rivers Tisza and Szamos during summer 2003 and for comparison purpose also in the river Maros, a tributary of the Tisza river, during 2005. In order to determine their heavy metal content, single specimens were prepared and analysed by Total Reflection X-ray Fluorescence Spectrometry (TRXF) according to the modified dry method. Fe was much lower and Mn and Zn much higher concentrated in benthos from the more contaminated Szamos river compared to the Tisza and Maros rivers. In this sense, the benthic organisms reflected very well the enhanced metal concentrations in the contaminated rivers being suitable as bioindicators of metal contamination. However, the sediment bioaccumulation factor was low at all sampling sites indicating a low bioavailability of trace metals for benthic organisms.

  3. Determination of alkylphenol and alkylphenolethoxylates in biota by liquid chromatography with detection by tandem mass spectrometry and fluorescence spectroscopy

    Science.gov (United States)

    Schmitz-Afonso, I.; Loyo-Rosales, J.E.; de la Paz Aviles, M.; Rattner, B.A.; Rice, C.P.

    2003-01-01

    A quantitative method for the simultaneous determination of octylphenol, nonylphenol and the corresponding ethoxylates (1 to 5) in biota is presented. Extraction methods were developed for egg and fish matrices based on accelerated solvent extraction followed by a solid-phase extraction cleanup, using octadecylsilica or aminopropyl cartridges. Identification and quantitation were accomplished by liquid chromatography-electrospray tandem mass spectrometry (LC-MS-MS) and compared to the traditional liquid chromatography with fluorescence spectroscopy detection. LC-MS-MS provides high sensitivity and specificity required for these complex matrices and an accurate quantitation with the use of 13C-labeled internal standards. Quantitation limits by LC-MS-MS ranged from 4 to 12 ng/g in eggs, and from 6 to 22 ng/g in fish samples. These methods were successfully applied to osprey eggs from the Chesapeake Bay and fish from the Great Lakes area. Total levels found in osprey egg samples were up to 18 ng/g wet mass and as high as 8.2 ug/g wet mass in the fish samples.

  4. High temperature monitoring of silicon carbide ceramics by confocal energy dispersive X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Li, Fangzuo; Liu, Zhiguo; Sun, Tianxi, E-mail: stx@bnu.edu.cn

    2016-04-15

    Highlights: • X-ray scattering was used for monitoring oxidation situation of SiC ceramics. • A calibration curve was obtained. • The confocal X-ray scattering technology was based on polycapillary X-ray optics. • The variations of contents of components of SiC ceramics were obtained. - Abstract: In the present work, we presented an alternative method for monitoring of the oxidation situation of silicon carbide (SiC) ceramics at various high temperatures in air by measuring the Compton-to-Rayleigh intensity ratios (I{sub Co}/I{sub Ra}) and effective atomic numbers (Z{sub eff}) of SiC ceramics with the confocal energy dispersive X-ray fluorescence (EDXRF) spectrometer. A calibration curve of the relationship between I{sub Co}/I{sub Ra} and Z{sub eff} was established by using a set of 8 SiC calibration samples. The sensitivity of this approach is so high that it can be easily distinguished samples of Z{sub eff} differing from each other by only 0.01. The linear relationship between the variation of Z{sub eff} and the variations of contents of C, Si and O of SiC ceramics were found, and the corresponding calculation model of the relationship between the ΔZ and the ΔC{sub C}, ΔC{sub Si}, and ΔC{sub O} were established. The variation of contents of components of the tested SiC ceramics after oxidation at high temperature was quantitatively calculated based on the model. It was shown that the results of contents of carbon, silicon and oxygen obtained by this method were in good agreement with the results obtained by XPS, giving values of relative deviation less than 1%. It was concluded that the practicality of this proposed method for monitoring of the oxidation situation of SiC ceramics at high temperatures was acceptable.

  5. Determination of trace selenium in high purity tellurium by hydride generation atomic fluorescence spectrometry after solid phase extraction of a diaminobenzidine-selenium chelate

    Science.gov (United States)

    Tong, Wang; Ying, Zeng; Jinyong, Xu

    2016-09-01

    Macroporous adsorption resin was used as the sorbent for solid phase extraction and determination of the trace Se content in high purity tellurium prior to hydride generation atomic fluorescence spectrometry analysis. Selenium was converted into an organic Se chelate using 3,3‧-diaminobenzidine and was separated from the tellurium matrix by solid phase extraction. The resin was packed as a column for solid phase extraction. Under optimum conditions, trace Se can be quantitatively extracted and the tellurium matrix can be removed. The Se in the eluate was determined by hydride generation atomic fluorescence spectrometry. The limit of detection (3σ) of this method was 0.22 ng g- 1 and the relative standard deviation (RSD, n = 5) ranged from 2.0 to 2.5% for the three investigated tellurium samples. The proposed method was successfully applied for the determination of the trace Se content in high purity tellurium samples.

  6. Characterization of Roman glass tesserae from the Coriglia excavation site (Italy) via energy-dispersive X-ray fluorescence spectrometry and Raman spectroscopy

    Science.gov (United States)

    Donais, Mary Kate; Van Pevenage, Jolien; Sparks, Andrew; Redente, Monica; George, David B.; Moens, Luc; Vincze, Laszlo; Vandenabeele, Peter

    2016-12-01

    The combined use of handheld energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and micro-energy-dispersive X-ray fluorescence spectrometry permitted the characterization of Roman glass tesserae excavation from the Coriglia (Italy) archeological site. Analyses of ten different glass colors were conducted as spot analyses on intact samples and as both spot analyses and line scans on select cross-sectioned samples. The elemental and molecular information gained from these spectral measurements allowed for the qualitative chemical characterization of the bulk glass, decolorants, opacifiers, and coloring agents. The use of an antimony opacifier in many of the samples supports the late Imperial phasing as determined through numismatic, fresco, ceramics, and architectural evidence. And dealinization of the exterior glass layers caused by the burial environment was confirmed.

  7. Direct analysis of blood serum by total reflection X-ray fluorescence spectrometry and application of an artificial neural network approach for cancer diagnosis*1

    Science.gov (United States)

    Hernández-Caraballo, Edwin A.; Marcó-Parra, Lué M.

    2003-12-01

    Iron, copper, zinc and selenium were determined directly in serum samples from healthy individuals ( n=33) and cancer patients ( n=27) by total reflection X-ray fluorescence spectrometry using the Compton peak as internal standard [L.M. Marcó P. et al., Spectrochim. Acta Part B 54 (1999) 1469-1480]. The standardized concentrations of these elements were used as input data for two-layer artificial neural networks trained with the generalized delta rule in order to classify such individuals according to their health status. Various artificial neural networks, comprising a linear function in the input layer, a hyperbolic tangent function in the hidden layer and a sigmoid function in the output layer, were evaluated for such a purpose. Of the networks studied, the (4:4:1) gave the highest estimation (98%) and prediction rates (94%). The latter demonstrates the potential of the total reflection X-ray fluorescence spectrometry/artificial neural network approach in clinical chemistry.

  8. Characterization of Roman glass tesserae from the Coriglia excavation site (Italy) via energy-dispersive X-ray fluorescence spectrometry and Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Donais, Mary Kate; Sparks, Andrew; Redente, Monica [Saint Anselm College, Department of Chemistry, Manchester, NH (United States); Pevenage, Jolien van; Moens, Luc; Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, Ghent (Belgium); George, David B. [Saint Anselm College, Department of Classics, Manchester, NH (United States); Vandenabeele, Peter [Ghent University, Department of Archaeology, Ghent (Belgium)

    2016-12-15

    The combined use of handheld energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, and micro-energy-dispersive X-ray fluorescence spectrometry permitted the characterization of Roman glass tesserae excavation from the Coriglia (Italy) archeological site. Analyses of ten different glass colors were conducted as spot analyses on intact samples and as both spot analyses and line scans on select cross-sectioned samples. The elemental and molecular information gained from these spectral measurements allowed for the qualitative chemical characterization of the bulk glass, decolorants, opacifiers, and coloring agents. The use of an antimony opacifier in many of the samples supports the late Imperial phasing as determined through numismatic, fresco, ceramics, and architectural evidence. And dealinization of the exterior glass layers caused by the burial environment was confirmed. (orig.)

  9. Simultaneous Determination of Fluorescein, Rhodamine 6G and Rhodamine B in Turbid Solution by Polarization Variable-Angle Synchronous Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.

  10. Development of a portable system of X-ray fluorescence spectrometry; Desenvolvimento de um sistema portatil de espectrometria por fluorescencia de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Mantuano, Andrea; Crisostomo, Jose V.V.; Barros, Mariana J.; Oliveira, Luis F.; Barroso, Regina C., E-mail: andreafisica@yahoo.com.b, E-mail: jose_vicente_crisostomo@yahoo.com.b, E-mail: mariana_jbarros@yahoo.co, E-mail: lfolive@oi.com.b, E-mail: cely_barroso@hotmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    2009-07-01

    This paper develops a compact and portable spectrometry system that will be used at the Laboratory of Applied Physics to the Biomedical and Environmental Sciences of the Institute of Physics/UERJ, Rio de Janeiro, Brazil. The laboratory both prepares the samples and develops the X-ray spectrometry techniques. The techniques of X-ray diffraction and fluorescence on various samples (biological, industrial and environmental) are used, attending to pos-graduation and graduation students, with multidisciplinary characteristics. The Mini-X system consists of X-ray mini tube MINI-X from Amptek with tungsten (W) target, and a compact spectrometer X123, also from Amptek that includes a detector, pre-amplifier, digital pulse processor, and multichannel. All the system is controlled by dedicated microprocessor. This work will present both a methodology for alignment and calibration of the system as far the first measurements performed using the X-ray fluorescence technique on standard samples. The multi elementary analysis by X-ray fluorescence (XRF) is based on the measurements of the characteristic X-ray intensity emitted by the chemical elements components of the samples when excited. Therefore, from the development of this compact and versatile system it will be possible to obtain the fluorescent intensities of the analysed samples at the Laboratory, not only at the research area but at the teaching area. Besides, new laboratory practices are being developed for the discipline of medical physics

  11. Methylmercury in water samples at the pg/L level by online preconcentration liquid chromatography cold vapor-atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Brombach, Christoph-Cornelius [Trace Element Speciation Laboratory, Department of Chemistry, Meston Walk, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Chen, Bin; Corns, Warren T. [PS Analytical, Arthur House, Crayfields Industrial Estate, Main Road, Orpington, Kent BR5 3HP (United Kingdom); Feldmann, Jörg [Trace Element Speciation Laboratory, Department of Chemistry, Meston Walk, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom); Krupp, Eva M., E-mail: e.krupp@abdn.ac.uk [Trace Element Speciation Laboratory, Department of Chemistry, Meston Walk, University of Aberdeen, Aberdeen AB24 3UE (United Kingdom)

    2015-03-01

    Ultra-traces of methylmercury at the sub-ppt level can be magnified in the foodweb and is of concern. In environmental monitoring a routine robust analytical method is needed to determine methylmercury in water. The development of an analytical method for ultra-trace speciation analysis of methylmercury (MeHg) in water samples is described. The approach is based on HPLC-CV-AFS with on-line preconcentration of water samples up to 200 mL, resulting in a detection limit of 40 pg/L (ppq) for MeHg, expressed as Hg. The unit consists of an optimized preconcentration column filled with a sulfur-based sorption material, on which mercury species are preconcentrated and subsequently eluted, separated and detected via HPLC-CV-AFS (high performance liquid chromatography–cold vapor atomic fluorescence spectrometry). During the method development a type of adsorbate material, the pH dependence, the sample load rate and the carry-over were investigated using breakthrough experiments. The method shows broad pH stability in the range of pH 0 to 7, without the need for buffer addition and shows limited matrix effects so that MeHg is quantitatively recovered from sewage, river and seawater directly in the acidified samples without sample preparation. - Highlights: • We demonstrate that a novel mixture of thiourea-thiolsilica shows an excellent trapping of MeHg between a broad pH range 1–6. • We develop the method so that it can potentially be automated for inorganic and methyl-mercury. • The method is matrix independent with highly accurate results for MeHg in hair CRM extracts and spiked water samples • The limit of detection is around 40 pg/L when just 200 mL sample is used, without any intensive preparation.

  12. Feasibility of wavelength dispersive X-ray fluorescence spectrometry for the determination of metal impurities in pharmaceutical products and dietary supplements in view of regulatory guidelines.

    Science.gov (United States)

    Figueiredo, Alexandra; Fernandes, Tânia; Costa, Isabel Margarida; Gonçalves, Luísa; Brito, José

    2016-04-15

    The aim of this study was to investigate the feasibility of Wavelength Dispersive X-ray Fluorescence (WDXRF) spectrometry for the measurement of As, Cd, Cr, Cu, Hg, Ir, Mn, Mo, Ni, Os, Pb, Pd, Pt, Rh, Ru and V impurities in pharmaceuticals and dietary supplements, in view of the requirements by EMA and USP for the measurement of elemental impurities in drug products and according to the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH guidelines). For that purpose, a 4 kW WDXRF spectrometer (S4 Pioneer, Bruker AXS) was used after system calibration. The linearity of the method was demonstrated by correlation coefficients in excess of 0.9 and by appropriate test of lack of fit, except for Cd, Hg, Pd, V and As, which were excluded from analysis. The calculated limits of detection and quantification were in the ranges 0.6-5.4 μg/g and 1.7-16.4 μg/g meeting defined acceptance criteria, except for Pb. The accuracy of the method, determined by the percent recovery (R) of known amounts of each element added to a selected drug, at 3 different concentration levels, was in the acceptance range 70-150% except for Os and Pt, in which case R was marginally outside that range. The repeatability of the method, assessed as the % residual standard deviation (%RSD) of 3 replicate measurements at 3 concentration levels, produced %RSD values lower than 20%, as required. These results show that the WDXRF method complies with the validation requirements defined by the European Pharmacopeia for Cu, Cr, Ir, Mn, Mo, Ni, Os, and Pt, and by the United States Pharmacopeia for Ir, Ni, Os and Pt. Therefore, it may be an alternative to the compendial analytical procedures recommended for such elements. The novelty of the present work is the application of WDXRF to final medicines and not only to active pharmaceutical ingredients and/or excipients.

  13. Determination of trace elements in freshwater rotifers and ciliates by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Woelfl, S.; Óvári, M.; Nimptsch, J.; Neu, T. R.; Mages, M.

    2016-02-01

    Element determination in plankton is important for the assessment of metal contamination of aquatic environments. Until recently, it has been difficult to determine elemental content in rotifers or ciliates derived from natural plankton samples because of the difficulty in handling and separation of these fragile organisms. The aim of this study was to evaluate methods for separation of rotifers and large ciliates from natural plankton samples (μg range dry weight) and subsequent analysis of their elemental content using total-reflection X-ray fluorescence spectrometry (TXRF). Plankton samples were collected from different aquatic environments (three lakes, one river) in Chile, Argentina and Hungary. From one to eighty specimens of five rotifer species (Brachionus calyciflorus, Brachionus falcatus, Asplanchna sieboldii, Asplanchna sp., Philodina sp.) and four to twelve specimens of one large ciliate (Stentor amethystinus) were prepared according to the dry method originally developed for microcrustaceans, and analysed by TRXF following in situ microdigestion. Our results demonstrated that it possible to process these small and fragile organisms (individual dry mass: 0.17-9.39 μg ind- 1) via careful washing and preparation procedures. We found species-dependent differences of the element mass fractions for some of the elements studied (Cr, Mn, Fe, Ni, Cu, Zn, As, Pb), especially for Cu, Fe and Mn. One large rotifer species (A. sieboldii) also showed a negative correlation between individual dry weight and the element content for Pb, Ni and Cr. We conclude that our application of the in situ microdigestion-TRXF method is suitable even for rotifers and ciliates, greatly expanding the possibilities for use of plankton in biomonitoring of metal contamination in aquatic environments.

  14. Zinc and cadmium accumulation in single zebrafish (Danio rerio) embryos - A total reflection X-ray fluorescence spectrometry application

    Energy Technology Data Exchange (ETDEWEB)

    Mages, Margarete [UFZ - Helmholtz Centre for Environmental Research, Dept. River Ecology Brueckstr. 3a/39114 Magdeburg/Germany (Germany); University of Lueneburg, Institute of Ecology and Environmental Chemistry, Department Environmental Chemistry, Scharnhorststrasse 1/21335 Lueneburg/Germany (Germany)], E-mail: margarete.mages@ufz.de; Bandow, Nicole [UFZ - Helmholtz Centre for Environmental Research, Dept. Effect Directed Analysis, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Kuester, Eberhard [UFZ - Helmholtz Centre for Environmental Research, Dept. Bioanalytical Ecotoxicology, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Brack, Werner [UFZ - Helmholtz Centre for Environmental Research, Dept. Effect Directed Analysis, Permoser Strasse 15/ 04318 Leipzig/Germany (Germany); Tuempling, Wolf von [UFZ - Helmholtz Centre for Environmental Research, Dept. River Ecology Brueckstr. 3a/39114 Magdeburg/Germany (Germany)

    2008-12-15

    Trace metals such as Cadmium (Cd) and Zinc (Zn) are known to exhibit adverse effects on many aquatic organisms including early life stages of fish. In contact with contaminated sediment, fish eggs and embryos may be exposed to metals via the water phase as well as via direct contact with contaminated particles. This may result in body burdens that are difficult to predict and may vary according to individual micro scale exposure conditions. The highly sensitive total reflection X-ray fluorescence spectrometry (TXRF) may provide a tool to analyse individual embryos for internal contaminant concentrations and thus helps to develop a better understanding of dose-response relationships. To test this hypothesis, embryos of Danio rerio were exposed to Cd and Zn spiked sediment in different treatments applying an ion exchange resin for modification of bioavailable concentrations. The TXRF analysis indicated individual embryos with dramatically enhanced exposure compared to other individuals despite uniform exposure conditions on a macro scale. Ion exchanger reduced embryo Zn concentrations to values close to control value with a comparably low standard deviation. Cadmium concentrations in embryos were in the range of 4000 to 7000 {mu}g/g with a median of 5740 {mu}g/g. A commercial ion exchanger reduced individual body burdens by a factor 50 to 100. Individual peak body burdens of up to 3160 {mu}g/g were accompanied by reduced weight of the fish eggs due to early death i.e. coagulation. The investigation of exposure and effects on an individual-based scale may significantly help to reduce uncertainty and inconsistencies occurring in conventional analysis of pooled fish embryo samples.

  15. 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.

  16. Improving the analytical performance of hydride generation non-dispersive atomic fluorescence spectrometry. Combined effect of additives and optical filters

    Science.gov (United States)

    D'Ulivo, Alessandro; Bramanti, Emilia; Lampugnani, Leonardo; Zamboni, Roberto

    2001-10-01

    The effects of tetrahydroborate and acid concentration and the presence of L-cysteine and thiourea were investigated in the determination of As, Bi and Sn using continuous flow hydride generation atomic fluorescence spectrometry (HG AFS). The aim was to find conditions allowing the control of those effects exerting negative influence on the analytical performance of the HG AFS apparatus. The effects taken into account were: (i) the radiation scattering generated by carryover of solution from the gas-liquid separator to the atomizer; (ii) the introduction of molecular species generated by tetrahydroborate decomposition into the atomizer; and (iii) interference effects arising from other elements in the sample matrix and from different acids. The effects (i) and (ii) could be controlled using mild reaction conditions in the HG stage. The effect of HG conditions on carryover was studied by radiation scattering experiments without hydride atomization. Compromised HG conditions were found by studying the effects of tetrahydroborate (0.1-20 g l -1) and acid (0.01-7 mol l -1) concentration, and the addition of L-cysteine (10 g l -1) and thiourea (0.1 mol l -1) on the HG AFS signals. The effect of optical filters was investigated with the aim of improving the signal-to-noise ratio. Optical filters with peak wavelengths of 190 and 220 nm provided an improvement of detection limits by factors of approximately 4 and 2 for As and Te, respectively. Under optimized conditions the detection limits were 6, 5, 3, 2, 2 and 9 ng l -1 for As, Sb, Bi, Sn, Se and Te, respectively. Good tolerance to various acid compositions and sample matrices was obtained by using L-cysteine or thiourea as masking agents. Determination of arsenic in sediment and copper certified reference materials, and of bismuth in steel, sediment, soil and ore certified reference material is reported.

  17. Determination of As concentration in earthworm coelomic fluid extracts by total-reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Allegretta, Ignazio; Porfido, Carlo; Panzarino, Onofrio; Fontanella, Maria Chiara; Beone, Gian Maria; Spagnuolo, Matteo; Terzano, Roberto

    2017-04-01

    Earthworms are often used as sentinel organisms to study As bioavailability in polluted soils. Arsenic in earthworms is mainly sequestrated in the coelomic fluids whose As content can therefore be used to asses As bioavalability. In this work, a method for determining As concentration in coelomic fluid extracts using total-reflection X-ray fluorescence spectrometry (TXRF) is presented. For this purpose coelomic fluid extracts from earthworms living in three polluted soils and one non-polluted (control) soil have been collected and analysed. A very simple sample preparation was implemented, consisting of a dilution of the extracts with polyvinyl alcohol (PVA) using a 1:8 ratio and dropwise deposition of the sample on the reflector. A detection limit of 0.2 μg/l and quantification limit of 0.6 μg/l was obtained in the diluted samples, corresponding to 2 μg/l and 6 μg/l in the coelomic fluid extracts, respectively. This allowed to quantify As concentration in coelomic fluids extracted from earthworms living in soils polluted with As at concentrations higher than 20 mg/kg (considered as a pollution threshold for agricultural soils). The TXRF method has been validated by comparison with As concentrations in standards and by analysing the same samples by ICP-MS, after acid digestion of the sample. The low limit of detection, the proven reliability of the method and the little sample preparation make TXRF a suitable, cost-efficient and ;green; technique for the analysis of As in earthworm coelomic fluid extracts for bioavailability studies.

  18. Synthesis and properties of fluorescent hybrid nanocomposites based on copolyacrylates with dansyl semicarbazide units

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Emil C., E-mail: emilbur@icmpp.r [' Petru Poni' Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Chibac, Andreea L.; Buruiana, Tinca; Musteata, Valentina [' Petru Poni' Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2011-07-15

    Our study examined a series of hybrid composites containing copolyacrylate with semicarbazide-dansyl groups prepared by conventional radical polymerization of monomers in the organic montmorillonite modified with alkyl chains of variable length or using the sol-gel technique. The structure and the chemical composition of the copolymers N-methacryloyloxyethylcarbamoyl-5- (dimethylaminonaphtalene-1-sulfonohydrazine)-co-methyl metahacrylate (DnsSA-co-MMA) and N-methacryloyloxyethylcarbamoyl -5-(dimethylaminonaphtalene-1-sulfonohydrazine)-co-dodecylacrylamide (DnsSA-co-DA) as well as their nanocomposites (HC-P1, HC-P2, HC-P3, HC-P4) were confirmed by spectral analysis ({sup 1}H NMR, FTIR, UV/vis), thermal methods and atomic force microscopy. To quantify the effect of the inorganic component compared to pure photopolymers we evaluated the properties of hybrid composites, including dielectric characterization. Additionally, these materials have been tested in experiments of fluorescence quenching by acids (HCl, p-toluenesulfonic acid, 1-S-camphorsulfonic acid), metallic cation (Cu{sup 2+}) and nitrobenzene. The results suggest that such nanocomposites could find applications as fluorescence-based chemosensors in homogeneous organic solutions or thin films. - Highlights: {yields} Dansylated hybrid composites were prepared by polymerization of monomers in organo-MMT or by sol-gel. {yields} Quenching effects by acids, Cu{sup 2+} and nitrobenzene in solution/film were evidenced. {yields} A fluorescence dequenching was observed for the composite with silsesquixane units. {yields} A reversible process occurs in the composite film exposed to nitrobenzene vapors.

  19. Fast direct reconstruction strategy of dynamic fluorescence molecular tomography using graphics processing units

    Science.gov (United States)

    Chen, Maomao; Zhang, Jiulou; Cai, Chuangjian; Gao, Yang; Luo, Jianwen

    2016-06-01

    Dynamic fluorescence molecular tomography (DFMT) is a valuable method to evaluate the metabolic process of contrast agents in different organs in vivo, and direct reconstruction methods can improve the temporal resolution of DFMT. However, challenges still remain due to the large time consumption of the direct reconstruction methods. An acceleration strategy using graphics processing units (GPU) is presented. The procedure of conjugate gradient optimization in the direct reconstruction method is programmed using the compute unified device architecture and then accelerated on GPU. Numerical simulations and in vivo experiments are performed to validate the feasibility of the strategy. The results demonstrate that, compared with the traditional method, the proposed strategy can reduce the time consumption by ˜90% without a degradation of quality.

  20. Acceleration of Early-Photon Fluorescence Molecular Tomography with Graphics Processing Units

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2013-01-01

    Full Text Available Fluorescence molecular tomography (FMT with early-photons can improve the spatial resolution and fidelity of the reconstructed results. However, its computing scale is always large which limits its applications. In this paper, we introduced an acceleration strategy for the early-photon FMT with graphics processing units (GPUs. According to the procedure, the whole solution of FMT was divided into several modules and the time consumption for each module is studied. In this strategy, two most time consuming modules (Gd and W modules were accelerated with GPU, respectively, while the other modules remained coded in the Matlab. Several simulation studies with a heterogeneous digital mouse atlas were performed to confirm the performance of the acceleration strategy. The results confirmed the feasibility of the strategy and showed that the processing speed was improved significantly.

  1. X-Ray Fluorescence Spectrometry. II Determination of Uranium in ores; Espectrometria de fluorescencia de Rayos X. II-Aplicacion a la determinacion de uranio en minerales

    Energy Technology Data Exchange (ETDEWEB)

    Bermudez Polonio, J.; Crus Castillo, F. de la; Fernandez Cellini, R.

    1961-07-01

    A method of analysis of uranium in ores by X-ray spectrometry was developed, using the internal standard technique. Strontium was found to be the most suitable internal standard for general use. A Norelco Philips X-ray fluorescent spectrometer was used in this work, equipped with a lithium fluoride crystal acting as a diffraction grating analyzer. The intensity of the uranium-L {alpha}{sub 1} spectral line is calculated and related to corresponding strontium-K{sub {alpha}} spectral line, both detected with a Scintillation Counter. (Author) 31 refs.

  2. Comparison of High Performance Liquid Chromatography with Fluorescence Detector and with Tandem Mass Spectrometry methods for detection and quantification of Ochratoxin A in green and roasted coffee beans

    Directory of Open Access Journals (Sweden)

    Raquel Duarte da Costa Cunha Bandeira

    2013-12-01

    Full Text Available Two analytical methods for the determination and confirmation of ochratoxin A (OTA in green and roasted coffee samples were compared. Sample extraction and clean-up were based on liquid-liquid phase extraction and immunoaffinity column. The detection of OTA was carried out with the high performance liquid chromatography (HPLC combined either with fluorescence detection (FLD, or positive electrospray ionization (ESI+ coupled with tandem mass spectrometry (MS-MS. The results obtained with the LC-ESI-MS/MS were specific and more sensitive, with the advantages in terms of unambiguous analyte identification, when compared with the HPLC-FLD.

  3. Simultaneous determination of p-arsanilic acid and roxarsone in feed by liquid chromatography-hydride generation online coupled with atomic fluorescence spectrometry.

    Science.gov (United States)

    Liu, Jianjing; Yu, Hongxia; Song, Haibin; Qiu, Jing; Sun, Fengmei; Li, Ping; Yang, Shuming

    2008-08-01

    A novel, simple and sensitive liquid chromatography-hydride generation online coupled with atomic fluorescence spectrometry (LC-HG-AFS) method was developed for simultaneous determination of p-arsanilic acid (p-ASA) and roxarsone in feed. 20% Methanol aqueous was used as extraction reagent, after preprocessing samples by ultrasonic oscillation, then injected into the chromatography Waters symmetry shield RP18 analytical column (150mm x 4.6mm, 5 microm), finally detected by an atomic fluorescence spectrometer. The calibration curves of analyses were linear over a range of concentrations (0.2-4mg L-1 and the correlation coefficients were higher than 0.9990. The limits of detection were 0.2 mg L-1. The method has been validated by linearity, precision and recovery. p-ASA and roxarsone in feed can be successfully and simultaneously determined using the developed method without a tedious pretreatment procedure.

  4. Total Mercury Determination in Petroleum Green Coke and Oily Sludge Samples by Cold Vapor Atomic Fluorescence Spectrometry

    National Research Council Canada - National Science Library

    Camera, Adriana S; Maranhão, Tatiane A; Oliveira, Fernando J. S; Silva, Jessee S. A; Frescura, Vera L. A

    2015-01-01

    ...+ before the atomic vapor formation. Accuracy of the method was evaluated through certified reference material, for green coke, and comparison with cold vapor atomic absorption spectrometry (CV AAS), for oily sludge...

  5. Quantitative fluorescence spectroscopy and flow cytometry analyses of cell-penetrating peptides internalization pathways: optimization, pitfalls, comparison with mass spectrometry quantification

    Science.gov (United States)

    Illien, Françoise; Rodriguez, Nicolas; Amoura, Mehdi; Joliot, Alain; Pallerla, Manjula; Cribier, Sophie; Burlina, Fabienne; Sagan, Sandrine

    2016-11-01

    The mechanism of cell-penetrating peptides entry into cells is unclear, preventing the development of more efficient vectors for biotechnological or therapeutic purposes. Here, we developed a protocol relying on fluorometry to distinguish endocytosis from direct membrane translocation, using Penetratin, TAT and R9. The quantities of internalized CPPs measured by fluorometry in cell lysates converge with those obtained by our previously reported mass spectrometry quantification method. By contrast, flow cytometry quantification faces several limitations due to fluorescence quenching processes that depend on the cell line and occur at peptide/cell ratio >6.108 for CF-Penetratin. The analysis of cellular internalization of a doubly labeled fluorescent and biotinylated Penetratin analogue by the two independent techniques, fluorometry and mass spectrometry, gave consistent results at the quantitative and qualitative levels. Both techniques revealed the use of two alternative translocation and endocytosis pathways, whose relative efficacy depends on cell-surface sugars and peptide concentration. We confirmed that Penetratin translocates at low concentration and uses endocytosis at high μM concentrations. We further demonstrate that the hydrophobic/hydrophilic nature of the N-terminal extremity impacts on the internalization efficiency of CPPs. We expect these results and the associated protocols to help unraveling the translocation pathway to the cytosol of cells.

  6. Non-dispersive atomic-fluorescence spectrometry of trace amounts of bismuth by introduction of its gaseous hydride into a premixed argon (entrained air)-hydrogen flame.

    Science.gov (United States)

    Kobayashi, S; Nakahara, T; Musha, S

    1979-10-01

    A method has been developed for the determination of bismuth by generation of its gaseous hydride and introduction of the hydride into a premixed argon (entrained air)-hydrogen flame, the atomic-fluorescence lines from which are all detected by use of a non-dispersive system. The detection limit is 5 pg/ml, or 0.1 ng of bismuth, but the reagent blank found in a 20-ml sample volume was approximately 2 ng of bismuth. Analytical working curves obtained by measuring peak-heights and integrated peak-areas of the signals are linear over a range of about four orders of magnitude from the detection limit. Perchloric, phosphoric and sulphuric acids up to 2.0M concentration give no interference, but nitric acid gives slight depression of the signal. The presence of silver, gold, nickel, palladium, platinum, selenium and tellurium in 1000-fold ratio to bismuth causes pronounced depression of the signal, whereas mercury and tin slightly enhance the atomic-fluorescence signal. The method has been applied to the determination of bismuth in aluminium-base alloys and sulphide ores with use of the standard additions method. The results are in good agreement with those obtained by flame atomic-absorption spectrometry and optical emission spectrometry with an inductively coupled plasma.

  7. Characterization of flagellar cysteine-rich sperm proteins involved in motility, by the combination of cellular fractionation, fluorescence detection, and mass spectrometry analysis.

    Science.gov (United States)

    Cabrillana, María E; Monclus, María A; Sáez Lancellotti, Tania E; Boarelli, Paola V; Clementi, Marisa A; Vincenti, Amanda E; Yunes, Roberto F M; Fornés, Miguel W

    2011-09-01

    Mammalian sperm proteins undergo thiol group (SH) oxidation to form disulfides bonds (SS) as they travel through the epididymis during cell maturation. Disulfide bonds are involved in chromatin condensation and tail organelle stabilization. In this work, we used a fluorescent thiol-selective labeling agent, monobromobimane (mBBr), to study the protein thiol status of rat sperm during maturation. Fluorescence signal decrease along the epididymal trip, more evidently in the head, but also in the tail, indicates that both sub cellular regions participate in the thiol changes. The sources of the fluorescence signal are sulfhydryls sperm proteins labeled by mBBr (mBBr-spp). Initial attempts to identify the mBBr-spp labeled were detected in the initial-caput, but not in the distal cauda-segment of the epididymis in sodium dodecyl sulfate (SDS)-PAGE analysis. This phenomenon could be due to protein resistance to solubilization. For this reason, disulfide bond reduction was accomplished by sodium dodecyl sulfate plus dithiothreitol treatment to recover the mBBr signal in SDS-PAGE. Under this protocol, a major 27 kDa protein band displays a strong signal. Protein identification by mass spectrometry and sequence database searching correlated this protein with the outer dense fiber 1 (ODF1). The mBBr specifically bound to N-terminal domain cysteine of ODF1. The mBBr reduces rat sperm motility, quantitatively and qualitatively, and the effects are dose dependent, without significantly increasing the percentage of dead sperm. Thus, we found that ODF1 is highly responsible for mBBr fluorescence detection in the sperm tail, and the motility inhibition by the fluorescence marker indicates that ODF1 N-terminal domain are related to sperm motility. © 2011 Wiley-Liss, Inc.

  8. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Khuder, A. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)], E-mail: scientific2@aec.org.sy; Sawan, M.Kh.; Karjou, J. [Department of Chemistry, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic); Razouk, A.K. [Department of Agriculture, Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2009-07-15

    X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white wormwood (Artemisia herba-alba)

  9. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive X-ray fluorescence and total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Khuder, A.; Sawan, M. Kh.; Karjou, J.; Razouk, A. K.

    2009-07-01

    X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise ( Anisum vulgare), licorice root ( Glycyrrhiza glabra), and white wormwood ( Artemisia herba-alba).

  10. Combination of a spinning disc confocal unit with frequency-domain fluorescence lifetime imaging microscopy.

    NARCIS (Netherlands)

    van Munster, E.B.; Goedhart, J.; Kremers, G.J.; Manders, E.M.M.; Gadella, Th.W.J.

    2007-01-01

    BACKGROUND: Wide-field frequency-domain fluorescence lifetime imaging microscopy (FLIM) is an established technique to determine fluorescence lifetimes. Disadvantage of wide-field imaging is that measurements are compromised by out-of-focus blur. Conventional scanning confocal typically means long

  11. 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)

  12. Preliminary validation of handheld X-ray fluorescence spectrometry: distinguishing osseous and dental tissue from nonbone material of similar chemical composition.

    Science.gov (United States)

    Zimmerman, Heather A; Schultz, John J; Sigman, Michael E

    2015-03-01

    One of the tasks of a forensic anthropologist is to sort human bone fragments from other materials, which can be difficult when dealing with highly fragmented and taphonomically modified material. The purpose of this research is to develop a method using handheld X-ray fluorescence (HHXRF) spectrometry to distinguish human and nonhuman bone/teeth from nonbone materials of similar chemical composition using multivariate statistical analyses. The sample materials were derived primarily from previous studies: human bone and teeth, nonhuman bone, nonbiological materials, nonbone biological materials, and taphonomically modified materials. The testing included two phases, testing both the reliability of the instrument and the accuracy of the technique. The results indicate that osseous and dental tissue can be distinguished from nonbone material of similar chemical composition with a high degree of accuracy (94%). While it was not possible to discriminate rock apatite and synthetic hydroxyapatite from bone/teeth, this technique successfully discriminated ivory and octocoral.

  13. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Samantha J Mascuch

    Full Text Available White-nose syndrome (WNS caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  14. Simple method of determination of copper, mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Hołyńska, B.; Ostachowicz, B.; Wȩgrzynek, D.

    1996-06-01

    Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l -1, 60 ng l -1, and 60 ng l -1, respectively.

  15. Analysis of oligomer proanthocyanidins in different barley genotypes using high-performance liquid chromatography-fluorescence detection-mass spectrometry and near-infrared methodologies.

    Science.gov (United States)

    Verardo, Vito; Cevoli, Chiara; Pasini, Federica; Gómez-Caravaca, Ana María; Marconi, Emanuele; Fabbri, Angelo; Caboni, Maria Fiorenza

    2015-04-29

    Proanthocyanidins are a class of polyphenols present in many foodstuffs (i.e., tea, cocoa, berries, etc.) that may reduce the risk of several chronic diseases. Barley, with sorghum, rice, and wheat, are the only cereals that contain these compounds. Because of that, two barley genotypes, named waxy and non-waxy, were analyzed by normal-phase high-performance liquid chromatography-fluorescence detection-mass spectrometry (NP-HPLC-FLD-MS). Total proanthocyanidin content ranged between 293.2 and 652.6 μg/g of flour. Waxy samples reported the highest content (p determination coefficients (R(2)) ranging from 0.92 to 0.97, in test set validation. Because of that, this study highlights that NIR spectroscopy technology with multivariate calibration analysis could be successfully applied as a rapid method to determine proanthocyanidin content in barley.

  16. Application of energy dispersive X-ray fluorescence spectrometry to polychrome terracotta sculptures from the Alcobaça Monastery, Portugal

    Directory of Open Access Journals (Sweden)

    Agnès Le Gac

    2015-02-01

    Full Text Available Portable energy dispersive X-ray fluorescence spectrometry (EDXRF was used in the Alcobaça Monastery, in order to study the chromatic coatings applied to terracotta statues that belong to two seventeenth-century monumental groupings. The main goal of this scientific approach consisted in determining the elemental composition of the constitutive layers and in trying to reconstitute the existing polychromy, taking into account the technical aspects observed at naked eye. The measurements carried out by EDXRF allowed a first material characterization of these artworks. By comparing the results obtained in each statue, it was possible to attest the application of a seventeenth-century coating to each one and at least a subsequent intervention in the form of a refurbishment or a new polychromy. According to the materials employed in their production, it appears that the refurbishment is likely dated from the 19th century while the new polychromy is still dated from the 18th century.

  17. Direct detection of fungal siderophores on bats with white-nose syndrome via fluorescence microscopy-guided ambient ionization mass spectrometry

    Science.gov (United States)

    Mascuch, Samantha J.; Moree, Wilna J.; Cheng-Chih Hsu, Cheng-Chih; Turner, Gregory G.; Cheng, Tina L.; Blehert, David S.; Kilpatrick, A. Marm; Frick, Winifred F.; Meehan, Michael J.; Dorrestein, Pieter C.; Gerwick, Lena

    2015-01-01

    White-nose syndrome (WNS) caused by the pathogenic fungus Pseudogymnoascus destructans is decimating the populations of several hibernating North American bat species. Little is known about the molecular interplay between pathogen and host in this disease. Fluorescence microscopy ambient ionization mass spectrometry was used to generate metabolic profiles from the wings of both healthy and diseased bats of the genus Myotis. Fungal siderophores, molecules that scavenge iron from the environment, were detected on the wings of bats with WNS, but not on healthy bats. This work is among the first examples in which microbial molecules are directly detected from an infected host and highlights the ability of atmospheric ionization methodologies to provide direct molecular insight into infection.

  18. Determination of molybdenum and tungsten at trace levels in rocks and minerals by solvent extraction and X-ray fluorescence spectrometry.

    Science.gov (United States)

    Sen, N; Roy, N K; Das, A K

    1989-06-01

    Separation by solvent extraction followed by X-ray fluorescence spectrometry has been used for determination of molybdenum and tungsten in rocks and minerals. Samples are decomposed either by heating with a mixture of hydrofluoric acid and perchloric acid or by fusion with potassium pyrosulphate, followed by extraction of molybdenum and tungsten with N-benzoylphenylhydroxylamine in toluene from 4-5M sulphuric acid medium. The extract is collected on a mass of cellulose powder, which is dried in vacuum, mixed thoroughly and pressed into a disc for XRF measurements. The method is free from all matrix effects and needs no mathematical corrections for interelement effects. The method is suitable for determination of molybdenum and tungsten in geological materials down to ppm levels, with reasonable precision and accuracy.

  19. Synthesis and Enantioselective Discrimination of Chiral Fluorescence Receptors Bearing Amino Acid Units

    Institute of Scientific and Technical Information of China (English)

    XU Kuo-Xi; HE Yong-Bing; QING Guang-Yan; QIN Hai-duan; LIU Shun-Ying; MENG Ling-Zhi

    2007-01-01

    Two chiral fluorescence receptors (1, 2) were synthesized, and their structures were characterized by IR, 1H NMR, 13C NMR, mass spectra and elemental analysis. The chiral recognition of receptors was studied by 1H NMR and fluorescence spectra. The results demonstrate that receptors and dibenzoyl tartrate anion formed a 1 : 1 complex. The receptor 1 exhibited a good enantioselective recognition ability toward the enantiomers of dibenzoyl tartrate anion.

  20. 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

    by the least-squares method to yield the fractions of La, Ce, Pr, and Nd in the samples. A calibration was established between the fractions of Ce and Nd and their abundances determined by mass spectrometry. Statistical considerations indicated that detection limits are of the order of 10 ppm. An X......-ray spectrometric scan of a longitudinally sliced drill core showed a close correlation between rare-earth abundances and appropriate minerals....

  1. Comparison and characterization of soybean and sunflower lecithins used for chocolate production by high-performance thin-layer chromatography with fluorescence detection and electrospray mass spectrometry.

    Science.gov (United States)

    Krüger, Stephanie; Bürmann, Laura; Morlock, Gertrud E

    2015-03-25

    The scarce availability of nongenetically modified soybeans on the world market represents a growing problem for food manufacturers. Hence, in this study the effects of substituting soybean with sunflower lecithin were investigated with regard to chocolate production. The glycerophospholipid pattern of the different lecithin samples was investigated by high-performance thin-layer chromatography fluorescence detection (HPTLC-FLD) and by HPTLC-positive ion electrospray ionization mass spectrometry (ESI(+)-MS) via the TLC-MS Interface and by scanning HPTLC-matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). Especially, the contents of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were of interest due to the influencing effects of these two glycerophospholipids on the rheological parameters of chocolate production. The lecithin substitution led to only slight differences in the rheological parameters of milk and dark chocolate. Limits of detection (LODs) and limits of quantification (LOQs) of seven glycerophospholipids were studied for three detection modes. Mean LODs ranged from 8 to 40 mg/kg for HPTLC-FLD and, using a single-quadrupole MS, from 10 to 280 mg/kg for HPTLC-ESI(+)-MS as well as from 15 to 310 mg/kg for HPTLC-FLD-ESI(+)-MS recorded after derivatization with the primuline reagent.

  2. Speciation of inorganic arsenic in drinking water by wavelength-dispersive X-ray fluorescence spectrometry after in situ preconcentration with miniature solid-phase extraction disks.

    Science.gov (United States)

    Hagiwara, Kenta; Inui, Tetsuo; Koike, Yuya; Aizawa, Mamoru; Nakamura, Toshihiro

    2015-03-01

    A rapid and simple method using wavelength-dispersive X-ray fluorescence (WDXRF) spectrometry after in situ solid-phase extraction (SPE) was developed for the speciation and evaluation of the concentration of inorganic arsenic (As) in drinking water. The method involves the simultaneous collection of As(III) and As(V) using 13 mm ϕ SPE miniature disks. The removal of Pb(2+) from the sample water was first conducted to avoid the overlapping PbLα and AsKα spectra on the XRF spectrum. To this end, a 50 mL aqueous sample (pH 5-9) was passed through an iminodiacetate chelating disk. The filtrate was adjusted to pH 2-3 with HCl, and then ammonium pyrrolidine dithiocarbamate solution was added. The solution was passed through a hydrophilic polytetrafluoroethylene filter placed on a Zr and Ca loaded cation-exchange disk at a flow rate of 12.5 mL min(-1) to separate As(III)-pyrrolidine dithiocarbamate complex and As(V). Each SPE disk was affixed to an acrylic plate using adhesive cellophane tape, and then examined by WDXRF spectrometry. The detection limits of As(III) and As(V) were 0.8 and 0.6 μg L(-1), respectively. The proposed method was successfully applied to screening for As speciation and concentration evaluation in spring water and well water.

  3. Airborne observations of regional variation in fluorescent aerosol across the United States

    Science.gov (United States)

    Perring, A. E.; Schwarz, J. P.; Baumgardner, D.; Hernandez, M. T.; Spracklen, D. V.; Heald, C. L.; Gao, R. S.; Kok, G.; McMeeking, G. R.; McQuaid, J. B.; Fahey, D. W.

    2015-02-01

    Airborne observations of fluorescent aerosol were made aboard an airship during CloudLab, a series of flights that took place in September and October of 2013 and covered a wideband of longitude across the continental U.S. between Florida and California and between 28 and 37 N latitudes. Sampling occurred from near the surface to 1000 m above the ground. A Wideband Integrated Bioaerosol Sensor (WIBS-4) measured average concentrations of supermicron fluorescent particles aloft (1 µm to 10 µm), revealing number concentrations ranging from 2.1 ± 0.8 to 8.7 ± 2.2 × 104 particles m-3 and representing up to 24% of total supermicron particle number. We observed distinct variations in size distributions and fluorescent characteristics in different regions, and attribute these to geographically diverse bioaerosol. Fluorescent aerosol detected in the east is largely consistent with mold spores observed in a laboratory setting, while a shift to larger sizes associated with different fluorescent patterns is observed in the west. Fluorescent bioaerosol loadings in the desert west were as high as those near the Gulf of Mexico, suggesting that bioaerosol is a substantial component of supermicron aerosol both in humid and arid environments. The observations are compared to model fungal and bacterial loading predictions, and good agreement in both particle size and concentrations is observed in the east. In the west, the model underestimated observed concentrations by a factor between 2 and 4 and the prescribed particle sizes are smaller than the observed fluorescent aerosol. A classification scheme for use with WIBS data is also presented.

  4. Determination of fluorescence-labeled asparaginyl-oligosaccharide in glycoprotein by reversed-phase ultraperformance liquid chromatography with electrospray ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Kurihara, Takamasa; Min, Jun Zhe; Toyo'oka, Toshimasa; Fukushima, Takeshi; Inagaki, Shinsuke

    2007-11-15

    Eight fluorescence reagents, i.e., DBD-F, NBD-F, DNS-Cl, NDA, PSC, FITC, Fmoc-Cl, and DMEQ-COCl, which are reactive to an amino functional group, were tested for the labeling of asparaginyl-oligosaccharides in a glycoprotein. Although the optimal reaction conditions and the fluorescence maximal wavelengths were different for each reagent, the highly sensitive fluorescence detection at the femtomole level of Disialo-Asn (a representative asparaginyl-oligosaccharide) was obtained from the labeling utilizing these reagents. Among them, PSC was the most reliable reagent in terms of detection sensitivity (approximately 3 fmol, signal-to-noise ratio of 5 (S/N = 5) on the chromatogram). However, the structural information could not be obtained from the fluorescence detection. Thus, the on-line determination of a real sample was carried out by UPLC-ESI-TOF-MS. The detection limit of the PSC-labeled Disialo-Asn by selected-ion chromatography was 58 fmol (S/N = 5). When the proposed procedure was applied to the determination of oligosaccharides in ovalbumin, 15 species of PSC-labeled oligosaccharides possessing Man, GlcNAc, and Gal units were identified from the UPLC-ESI-TOF-MS. The number of identified oligosaccharides was relatively greater than the method using Fmoc-Cl. Based on the ovalbumin results, the proposed labeling with PSC followed by UPLC-ESI-TOF-MS detection seems to be useful for the on-line asparaginyl-oligosaccharide analysis.

  5. Analysis of substrate specificity and kinetics of cyclic nucleotide phosphodiesterases with N'-methylanthraniloyl-substituted purine and pyrimidine 3',5'-cyclic nucleotides by fluorescence spectrometry.

    Directory of Open Access Journals (Sweden)

    Daniel Reinecke

    Full Text Available As second messengers, the cyclic purine nucleotides adenosine 3',5'-cyclic monophosphate (cAMP and guanosine 3',5'-cyclic monophosphate (cGMP play an essential role in intracellular signaling. Recent data suggest that the cyclic pyrimidine nucleotides cytidine 3',5'-cyclic monophosphate (cCMP and uridine 3',5'-cyclic monophosphate (cUMP also act as second messengers. Hydrolysis by phosphodiesterases (PDEs is the most important degradation mechanism for cAMP and cGMP. Elimination of cUMP and cCMP is not completely understood, though. We have shown that human PDEs hydrolyze not only cAMP and cGMP but also cyclic pyrimidine nucleotides, indicating that these enzymes may be important for termination of cCMP- and cUMP effects as well. However, these findings were acquired using a rather expensive HPLC/mass spectrometry assay, the technical requirements of which are available only to few laboratories. N'-Methylanthraniloyl-(MANT-labeled nucleotides are endogenously fluorescent and suitable tools to study diverse protein/nucleotide interactions. In the present study, we report the synthesis of new MANT-substituted cyclic purine- and pyrimidine nucleotides that are appropriate to analyze substrate specificity and kinetics of PDEs with more moderate technical requirements. MANT-labeled nucleoside 3',5'-cyclic monophosphates (MANT-cNMPs are shown to be substrates of various human PDEs and to undergo a significant change in fluorescence upon cleavage, thus allowing direct, quantitative and continuous determination of hydrolysis via fluorescence detection. As substrates of several PDEs, MANT-cNMPs show similar kinetics to native nucleotides, with some exceptions. Finally, they are shown to be also appropriate tools for PDE inhibitor studies.

  6. Airborne observations of regional variation in fluorescent aerosol across the United States

    OpenAIRE

    2015-01-01

    Airborne observations of fluorescent aerosol were made aboard an airship during CloudLab, a series of flights that took place in September and October of 2013 and covered a wideband of longitude across the continental U.S. between Florida and California and between 28 and 37-N latitudes. Sampling occurred from near the surface to 1000-m above the ground. A Wideband Integrated Bioaerosol Sensor (WIBS-4) measured average concentrations of supermicron fluorescent particles aloft (1-μm to 10-μm),...

  7. Lead discovery for mammalian elongation of long chain fatty acids family 6 using a combination of high-throughput fluorescent-based assay and RapidFire mass spectrometry assay.

    Science.gov (United States)

    Takamiya, Mari; Sakurai, Masaaki; Teranishi, Fumie; Ikeda, Tomoko; Kamiyama, Tsutomu; Asai, Akira

    2016-11-25

    A high-throughput RapidFire mass spectrometry assay is described for elongation of very long-chain fatty acids family 6 (Elovl6). Elovl6 is a microsomal enzyme that regulates the elongation of C12-16 saturated and monounsaturated fatty acids. Elovl6 may be a new therapeutic target for fat metabolism disorders such as obesity, type 2 diabetes, and nonalcoholic steatohepatitis. To identify new Elovl6 inhibitors, we developed a high-throughput fluorescence screening assay in 1536-well format. However, a number of false positives caused by fluorescent interference have been identified. To pick up the real active compounds among the primary hits from the fluorescence assay, we developed a RapidFire mass spectrometry assay and a conventional radioisotope assay. These assays have the advantage of detecting the main products directly without using fluorescent-labeled substrates. As a result, 276 compounds (30%) of the primary hits (921 compounds) in a fluorescence ultra-high-throughput screening method were identified as common active compounds in these two assays. It is concluded that both methods are very effective to eliminate false positives. Compared with the radioisotope method using an expensive (14)C-labeled substrate, the RapidFire mass spectrometry method using unlabeled substrates is a high-accuracy, high-throughput method. In addition, some of the hit compounds selected from the screening inhibited cellular fatty acid elongation in HEK293 cells expressing Elovl6 transiently. This result suggests that these compounds may be promising lead candidates for therapeutic drugs. Ultra-high-throughput fluorescence screening followed by a RapidFire mass spectrometry assay was a suitable strategy for lead discovery against Elovl6.

  8. Estimation on separation efficiency of aluminum from base-cap of spent fluorescent lamp in hammer crusher unit.

    Science.gov (United States)

    Rhee, Seung-Whee

    2017-09-01

    In order to separate aluminum from the base-cap of spent fluorescent lamp (SFL), the separation efficiency of hammer crusher unit is estimated by introducing a binary separation theory. The base-cap of SFL is composed by glass fragment, binder, ferrous metal, copper and aluminum. The hammer crusher unit to recover aluminum from the base-cap consists of 3stages of hammer crusher, magnetic separator and vibrating screen. The optimal conditions of rotating speed and operating time in the hammer crusher unit are decided at each stage. At the optimal conditions, the aluminum yield and the separation efficiency of hammer crusher unit are estimated by applying a sequential binary separation theory at each stage. And the separation efficiency between hammer crusher unit and roll crush system is compared to show the performance of aluminum recovery from the base-cap of SFL. Since the separation efficiency can be increased to 99% at stage 3, from the experimental results, it is found that aluminum from the base-cap can be sufficiently recovered by the hammer crusher unit. Copyright © 2017. Published by Elsevier Ltd.

  9. Study on Oxidation Pattern of Heated Vegetable Oil Based on Fluorescence Spectrometry%基于荧光光谱法的植物油加热氧化规律

    Institute of Scientific and Technical Information of China (English)

    赵守敬; 陈斌; 陆道礼

    2012-01-01

    To explore the variation pattern between oxidation of heated vegetable oil and its fluorescence spectra , molecular synchronous fluorescence spectrometry and LED - induced fixed wavelength fluorescence spectrometry were employed to determine fluorescence spectra of 5 kinds of edible vegetable oil( soybean oil, peanut blend oil, salad oil,sesame oil and palm oil) after being heated for different durations. The condition for synchronous fluorescence spectrometry was excitation wavelength at 190 ~ 800 nm with wavelength interval of 10 nm, and that for LED - induced fixed wavelength fluorescence spectrometry used 425 nm as the excitation wavelength. It was discovered that both synchronous fluorescence spectra and fixed wavelength excited fluorescence spectra of the edible vegetable oil changed regularly with the increase of heating time. The changes of synchronous fluorescence spectra were more obvious. After heating, all molecular synchronous fluorescence spectra showed a new fluorescence peak at 430 ~ 490 nm. The obtained data indicated that fluorescence spectrometry of vegetable oil can be a novel approach for studying oxidation pattern of edible vegetable oil upon heating, and the synchronous fluorescence spectrometry can be used to qualitatively analyze oxidation degree of the edible vegetable oil and to distinguish the above 5 kinds of edible vegetable oil.%为了探寻食用植物油加热后的氧化现象与荧光光谱之间的变化规律,采用了分子同步荧光法和LED固定波长激发的发射荧光光谱法,其中同步荧光光谱法的检测条件是激发波长190~800 nm、波长间隔10 nm,LED激发的发射荧光光谱法的检测条件是固定激发波长为425 nm,同时检测了5种食用植物油(一级大豆油、花生调和油、色拉油、芝麻油、棕榈油)不同加热时间下的两种荧光光谱,发现食用植物油随着加热时间的延长,其同步荧光光谱和固定波长激发的荧光光谱都呈规律性变化,同

  10. Rapid detection of toxic metals in non-crushed oyster shells by portable X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chou Ju, E-mail: Ju.Chou@selu.ed [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States); Clement, Garret; Bursavich, Bradley; Elbers, Don [Department of Chemistry and Physics, Southeastern Louisiana University, Hammond, LA 70402 (United States); Cao Baobao; Zhou Weilie [Advanced Material Research Institute, University of New Orleans, New Orleans, LA 70148 (United States)

    2010-06-15

    The aim of this study was the multi-elemental detection of toxic metals such as lead (Pb) in non-crushed oyster shells by using a portable X-ray fluorescence (XRF) spectrometer. A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using a portable XRF which provides a quick, quantitative, non-destructive, and cost-effective mean for assessment of oyster shell contamination from Pb. Pb contamination in oyster shells was further confirmed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results indicated that Pb is distributed in-homogeneously in contaminated shells. Oyster shells have a lamellar structure that could contribute to the high accumulation of Pb on oyster shells. - A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using XRF and contamination of lead on oyster shells was confirmed by XRF and SEM-EDS.

  11. Rapid detection of toxic metals in non-crushed oyster shells by portable X-ray fluorescence spectrometry.

    Science.gov (United States)

    Chou, Ju; Clement, Garret; Bursavich, Bradley; Elbers, Don; Cao, Baobao; Zhou, Weilie

    2010-06-01

    The aim of this study was the multi-elemental detection of toxic metals such as lead (Pb) in non-crushed oyster shells by using a portable X-ray fluorescence (XRF) spectrometer. A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using a portable XRF which provides a quick, quantitative, non-destructive, and cost-effective mean for assessment of oyster shell contamination from Pb. Pb contamination in oyster shells was further confirmed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results indicated that Pb is distributed in-homogeneously in contaminated shells. Oyster shells have a lamellar structure that could contribute to the high accumulation of Pb on oyster shells.

  12. 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.

  13. 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.

    Science.gov (United States)

    Musil, Stanislav; Matoušek, Tomáš; Currier, Jenna M; Stýblo, Miroslav; Dědina, Jiří

    2014-10-21

    This work describes the method of a selective hydride generation-cryotrapping (HG-CT) coupled to an extremely sensitive but simple in-house assembled and designed atomic fluorescence spectrometry (AFS) instrument for determination of toxicologically important As species. Here, an advanced flame-in-gas-shield atomizer (FIGS) was interfaced to HG-CT and its performance was compared to a standard miniature diffusion flame (MDF) atomizer. A significant improvement both in sensitivity and baseline noise was found that was reflected in improved (4 times) limits of detection (LODs). The yielded LODs with the FIGS atomizer were 0.44, 0.74, 0.15, 0.17 and 0.67 ng L(-1) for arsenite, total inorganic, mono-, dimethylated As and trimethylarsine oxide, respectively. Moreover, the sensitivities with FIGS and MDF were equal for all As species, allowing for the possibility of single species standardization with arsenate standard for accurate quantification of all other As species. The accuracy of HG-CT-AFS with FIGS was verified by speciation analysis in two samples of bottled drinking water and certified reference materials, NRC CASS-5 (nearshore seawater) and SLRS-5 (river water) that contain traces of methylated As species. As speciation was in agreement with results previously reported and sums of all quantified species corresponded with the certified total As. The feasibility of HG-CT-AFS with FIGS was also demonstrated by the speciation analysis in microsamples of exfoliated bladder epithelial cells isolated from human urine. The results for the sums of trivalent and pentavalent As species corresponded well with the reference results obtained by HG-CT-ICPMS (inductively coupled plasma mass spectrometry).

  14. Influence of the light-curing unit, storage time and shade of a dental composite resin on the fluorescence

    Science.gov (United States)

    Queiroz, R. S.; Bandéca, M. C.; Calixto, L. R.; Gaiao, U.; Cuin, A.; Porto-Neto, S. T.

    2010-07-01

    The aim of this study was to determine the influence of three light-curing units, storage times and colors of the dental composite resin on the fluorescence. The specimens (diameter 10.0 ± 0.1 mm, thickness 1.0 ± 0.1 mm) were made using a stainless steel mold. The mold was filled with the microhybrid composite resin and a polyethylene film covered each side of the mold. After this, a glass slide was placed on the top of the mold. To standardize the top surface of the specimens a circular weight (1 kg) with an orifice to pass the light tip of the LCU was placed on the top surface and photo-activated during 40 s. Five specimens were made for each group. The groups were divided into 9 groups following the LCUs (one QTH and two LEDs), storage times (immediately after curing, 24 hours, 7 and 30 days) and colors (shades: A2E, A2D, and TC) of the composite resin. After photo-activation, the specimens were storage in artificial saliva during the storage times proposed to each group at 37°C and 100% humidity. The analysis of variance (ANOVA) and Tukey’s posthoc tests showed no significant difference between storage times (immediately, 24 hours and 30 days) ( P > 0.05). The means of fluorescence had difference significant to color and light-curing unit used to all period of storage ( P 0.05).

  15. Determination of selenium at trace levels in geologic materials by energy-dispersive X-ray fluorescence spectrometry

    Science.gov (United States)

    Wahlberg, J.S.

    1981-01-01

    Low levels of selenium (0.1-500 ppm) in both organic and inorganic geologic materials can be semiquantitatively measured by isolating Se as a thin film for presentation to an energy-dispersive X-ray fluorescence spectrometer. Suitably pulverized samples are first digested by fusing with a mixture of Na2CO3 and Na2O2. The fusion cake is dissolved in distilled water, buffered with NH4Cl, and filtered to remove Si and the R2O3 group. A carrier solution of Na2TeO4, plus solid KI, hydrazine sulfate and Na2SO3, is added to the filtrate. The solution is then vacuum-filtered through a 0.45-??m pore-size filter disc. The filter, with the thin film of precipitate, is supported between two sheets of Mylar?? film for analysis. Good agreement is shown between data reported in this study and literature values reported by epithermal neutron-activation analysis and spectrofluorimetry. The method can be made quantitative by utilizing a secondary precipitation to assure complete recovery of the Se. The X-ray method offers fast turn-around time and a reasonably high production rate. ?? 1981.

  16. Evaluation on the stability of Hg in ABS disk CRM during measurements by wavelength dispersive X-ray fluorescence spectrometry.

    Science.gov (United States)

    Ohata, Masaki; Kidokoro, Toshihiro; Hioki, Akiharu

    2012-01-01

    The stability of Hg in an acrylonitrile-butadiene-styrene disk certified reference material (ABS disk CRM, NMIJ CRM 8116-a) during measurements by wavelength dispersion X-ray fluorescence (WD-XRF) analysis was evaluated in this study. The XRF intensities of Hg (L(α)) and Pb (L(α)) as well as the XRF intensity ratios of Hg (L(α))/Pb (L(α)) observed under different X-ray tube current conditions as well as their irradiation time were examined to evaluate the stability of Hg in the ABS disk CRM. The observed XRF intensities and the XRF intensity ratios for up to 32 h of measurements under 80 mA of X-ray tube current condition were constant, even though the surface of the ABS disk CRM was charred by the X-ray irradiation with high current for a long time. Moreover, the measurements on Hg and Pb in the charred disks by an energy dispersive XRF (ED-XRF) spectrometer showed constant XRF intensity ratios of Hg (L(α))/Pb (L(α)). From these results, Hg in the ABS disk CRM was evaluated to be sufficiently stable for XRF analysis.

  17. Determination of Te, Bi, Ni, Sb and Au by X-ray fluorescence spectrometry following electroenrichment on a copper cathode

    Science.gov (United States)

    Zawisza, Beata; Sitko, Rafał

    2007-10-01

    The electrodepositons of Te, Bi, Ni, Sb and Au from aqueous solution of pH = 1 on the cathode surface have been studied for X-ray fluorescence analysis (XRF). A special holder for a copper electrode has been constructed to perform the electrodeposition process on only one side of the electrode. After electrolysis, the copper electrode can be easily removed from the holder; after rinsing it with water and drying it can be analyzed by XRF. The proposed method of sample preparation and preconcentration of Te, Bi, Ni, Sb, Au provides suitable samples which are devoid of the negative and undesirable effects of XRF analysis, such as particle size and matrix effects. The influence of time on the deposition yield has been examined. The method of preconcentration is efficient. The inhomogeneity of the prepared specimens has been studied using internal standard method. The calibration is based on using synthetic standards, certified reference materials and standard addition method. The best results are achieved by the standard addition method. The agreement between results obtained with XRF analysis and certified values is satisfactory and indicates the usefulness of the proposed method for determination of Te, Bi, Ni, Sb and Au in anode slime.

  18. 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.

  19. Flow injection on-line solid phase extraction for ultra-trace lead screening with hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Wan, Zhuo; Xu, Zhangrun; Wang, Jianhua

    2006-01-01

    A flow injection (FI) on-line solid phase extraction (SPE) procedure for ultra-trace lead separation and preconcentration was developed, followed by hydride generation and atomic fluorescence spectrometric (AFS) detection. Lead is retained on an iminodiacetate chelating resin packed microcolumn, and is afterward eluted with 2.5% (v/v) hydrochloric acid to facilitate the hydride generation by reaction with alkaline tetrahydroborate solution with 1% (m/v) potassium ferricyanide as an oxidizing (or sensitizing) reagent. The hydride was separated from the reaction medium in the gas-liquid separator and swept into the atomizer for quantification. The chemical variables and the FI flow parameters were carefully optimized. With a sample loading volume of 4.8 ml, quantitative retention of lead was obtained, along with an enrichment factor of 11.3 and a sampling frequency of 50 h(-1). A detection limit of 4 ng l(-1), defined as 3 times the blank standard deviation (3 sigma), was achieved along with a RSD value of 1.6% at the 0.4 microg l(-1) level. The procedure was validated by determining lead contents in two certified reference materials, and its practical applicability was further demonstrated by analysing a variety of biological and environmental samples.

  20. High-throughput and sensitive screening of compounds with deoxyribonucleic acid-binding activity by a high-performance liquid chromatography-tandem mass spectrometry-fluorescence detection technique using palmatine as a fluorescence probe.

    Science.gov (United States)

    Fu, Qingrong; Wang, Hong; Lan, Yuexiang; Li, Sen; Hashi, Yuki; Chen, Shizhong

    2014-01-03

    A high-throughput biochemical detection method based on the combination of high-performance liquid chromatography (HPLC), multiple-stage mass spectrometry (MS(n)) and DNA-binding activity assay was developed and validated for the simultaneous screening and identification of DNA-binding compounds in complex samples. Palmatine was used as a sensitive, nontoxic and environmentally friendly DNA fluorescence probe. HPLC fingerprints, ultraviolet absorption spectra, MS(n) fragments of components, and DNA-binding activity profiles could be simultaneously recorded during real-time analysis. Using the proposed method, 25 compounds were identified from Lophatherum gracile Brongn extracts, of which 18 were novel compounds first identified in these extracts. Nineteen compounds showed DNA-binding activity, most of which were flavone glycosides, with distinct dose-effect and structure-activity relationships. The method was validated and was proven to have a good linearity in the range of concentrations used in the study. The limit of detection was 0.2020nmol. Our study indicated that the proposed method was sensitive, accurate, precise and reliable to be used for simultaneous screening and identification of DNA-binding compounds in complex samples.

  1. [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

  2. Study of interaction of iron and lead during their uptake process in wheat roots by total-reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Varga, Anita; Záray, Gyula; Fodor, Ferenc; Cseh, Edit

    1997-07-01

    Microwave assisted acidic digestion and total-reflection X-ray fluorescence spectrometry (TXRF) was used for the determination of lead and iron in wheat roots cultured in CaSO 4 solution, and treated with Pb(NO 3) 2 and Fe(III)-citrate or Fe(III)-EDTA under controlled conditions, respectively. It was established that lead has a stimulation effect on the iron uptake in the presence of Fe(III)-citrate. The lead uptake, however, is hardly influenced by iron independently from the complex forming agents applied. To check the stability of the accumulated iron and lead constituents, some of the roots were washed with various solutions and the removable iron and lead were also measured by TXRF. These experiments indicate that the presence of lead results in higher stability of iron constituents in the root; however, iron does not have any effect on the lead constituents, the stabilities of which increase in the order Pb-citrate

  3. Characterisation of Phenolic Compounds in South African Plum Fruits (Prunus salicina Lindl. using HPLC Coupled with Diode-Array, Fluorescence, Mass Spectrometry and On-Line Antioxidant Detection

    Directory of Open Access Journals (Sweden)

    Dalene de Beer

    2013-05-01

    Full Text Available Phenolic compounds are abundant secondary metabolites in plums, with potential health benefits believed to be due to their antioxidant activity, amongst others. Phenolic characterisation of South African Prunus salicina Lindl. plums is necessary to fully evaluate their potential health benefits. An HPLC method using diode-array detection (DAD for quantification of phenolic compounds was improved and fluorescence detection (FLD was added for quantification of flavan-3-ols. Validation of the HPLC-DAD-FLD method showed its suitability for quantification of 18 phenolic compounds, including flavan-3-ols using FLD, and phenolic acids, anthocyanins and flavonols using DAD. The method was suitable for characterisation of the phenolic composition of 11 South African plum cultivars and selections, including various types with yellow and red skin and flesh. The method was used in conjunction with mass spectrometry (MS to identify 24 phenolic compounds. Neochlorogenic acid and cyanidin-3-O-glucoside were the major compounds in most of the plums, while cyanidin-3-O-glucoside was absent in Sun Breeze plums with yellow skin and flesh. Post-column on-line coupling of the ABTS•+ scavenging assay with HPLC-DAD enabled qualitative evaluation of the relative contribution of individual phenolic compounds to the antioxidant activity. The flavan-3-ols, neochlorogenic acid and cyanidin-3-O-glucoside displayed the largest antioxidant response peaks.

  4. 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.

  5. Assessment of field portable X-ray fluorescence spectrometry for the in situ determination of heavy metals in soils and plants.

    Science.gov (United States)

    Gutiérrez-Ginés, María Jesús; Pastor, Jesús; Hernández, Ana Jesús

    2013-08-01

    In soil pollution studies, large numbers of soil samples collected at random need to be processed and analyzed to determine their heavy metal contents. This study was designed to assess the use of a field portable X-ray fluorescence (FPXRF) spectrometry system for the in situ determination of heavy metal levels in both soil and plant samples. First, we optimised the method using 84 reference soil standards and soil samples from known polluted sites. The optimised method was then used to determine heavy metals at three abandoned mine sites and two sealed landfills in central Spain. Given that knowledge of heavy metal levels in plants is important for the ecotoxicological study of these sites, the FPXRF device was also used to determine heavy metals in plants. Our results indicate the acceptable to high quality of the data provided by the system especially for soil samples. The cost-benefits and sustainability of this instrument in relation to other techniques were also examined. The use of the FPXRF system for the study of potentially polluted sites was found to save on costs, time and materials. Results indicate its suitable use for the preliminary screening of heavy-metal polluted sites.

  6. Evaluation of hydrodynamic chromatography coupled with UV-visible, fluorescence and inductively coupled plasma mass spectrometry detectors for sizing and quantifying colloids in environmental media.

    Science.gov (United States)

    Philippe, Allan; Schaumann, Gabriele E

    2014-01-01

    In this study, we evaluated hydrodynamic chromatography (HDC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of nanoparticles in environmental samples. Using two commercially available columns (Polymer Labs-PDSA type 1 and 2), a set of well characterised calibrants and a new external time marking method, we showed that flow rate and eluent composition have few influence on the size resolution and, therefore, can be adapted to the sample particularity. Monitoring the agglomeration of polystyrene nanoparticles over time succeeded without observable disagglomeration suggesting that even weak agglomerates can be measured using HDC. Simultaneous determination of gold colloid concentration and size using ICP-MS detection was validated for elemental concentrations in the ppb range. HDC-ICP-MS was successfully applied to samples containing a high organic and ionic background. Indeed, online combination of UV-visible, fluorescence and ICP-MS detectors allowed distinguishing between organic molecules and inorganic colloids during the analysis of Ag nanoparticles in synthetic surface waters and TiO₂ and ZnO nanoparticles in commercial sunscreens. Taken together, our results demonstrate that HDC-ICP-MS is a flexible, sensitive and reliable method to measure the size and the concentration of inorganic colloids in complex media and suggest that there may be a promising future for the application of HDC in environmental science. Nonetheless the rigorous measurements of agglomerates and of matrices containing natural colloids still need to be studied in detail.

  7. Characterization by Total Reflection X-ray Fluorescence Spectrometry of filtered water into the cave under the Sun Pyramid in Teotihuacan City

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, T. [National University of Mexico, Faculty of Chemistry, Building D, CU, O4510, Mexico, D.F. (Mexico)], E-mail: tmc@servidor.unam.mx; Zarazua, G.; Avila-Perez, P. [National Institute of Nuclear Research, Carr. Mexico-Toluca Km 36.5, 52045, Salazar, Ocoyoacac, Edo. de Mexico (Mexico); Juarez, F. [National University of Mexico, Institute of Geophysics, Circuito Institutos, CU, 04510 Mexico, D.F. (Mexico); Cabrera, L. [National University of Mexico, Faculty of Chemistry, Building D, CU, O4510, Mexico, D.F. (Mexico); Martinez, G. [Coordinacion Nacional de Conservacion del Patrimonio Cultural, Xicotencatl y General Anaya s/n., 04120, Mexico, D.F. (Mexico)

    2008-12-15

    Teotihuacan (50 km north-east Mexico City) was the most important ancient city in Mesoamerica and it flourished 200-750 AC. It is situated in the central part of the Valley of Teotihuacan, in Central Mexico. This study was carried out in the 102 m-long cave under the largest single construction, the massive Sun Pyramid, being located on the east side of the 'Avenue of the Dead', in the northern half-part of the city. The study shows the results of Total Reflection X-ray Fluorescence Spectrometry analysis and other techniques of a water sample obtained from the inside of the cave. The inside temperature ranged between 19 and 22 deg. C; relative humidity was between 98 and 99.3%; water-dropping velocity (water de-sorption capability) was 13.5 {mu}L min{sup -1}. Water samples from wells around the site were analyzed too. Metal concentration in all of the water samples matches the characteristics of the sampling site, well's depth, soil and minerals.

  8. On-line continuous generation of zinc chelates in the vapor phase by reaction with sodium dithiocarbamates and determination by atomic fluorescence spectrometry

    Science.gov (United States)

    Duan, Xuchuan; Sun, Rui; Fang, Jinliang

    2017-02-01

    The present study shows for the first time that a volatile zinc chelate species can be generated by the on-line continuous merging of an acidified sample solution with an aqueous sodium diethyldithiocarbamate solution followed by rapid separation using a frit-based bubble gas-liquid separator at room temperature. The operating conditions for the generation of the vaporous zinc chelate were preliminarily investigated by non-dispersive atomic fluorescence spectrometry. The possible mechanism of zinc vapor generation is discussed. The study shows that the volatile species is an intermediate species with very similar properties to diethyldithiocarbamic acid and a very short half-life in the acidic solution. Moreover, this species can only be generated by on-line mixing and rapid separation. The efficiency of generation was 33-85% depending on acidity. Under optimal conditions, the flow rates of the sample and Na-DDTC solution were 1.3 ml min- 1, the carrier argon flow rate was 225 ml min- 1, the acid concentration of the sample solution and the concentration of Na-DDTC were 0.05 M and 0.4% (m/v), respectively, the detection limit of zinc was 0.33 (3σ) ng ml- 1, and the relative standard deviation (RSD) was 1.3%. The accuracy of the method was verified by the determination of zinc in the plant reference materials GBW10015 (spinach) and GBW10045 (rice). The results were in good agreement with the certified reference values.

  9. Chemical characterization of groundwater in the area occupied by the cemetery: use of fluorescence spectrometry X-ray energy dispersive (EDXRF

    Directory of Open Access Journals (Sweden)

    Fernando Ernesto Ucker

    2012-12-01

    Full Text Available Generally, the burial of human corpses can contribute to groundwater pollution by the contact of leachate generated from the decomposition of bodies in the unsaturated zone of the subsoil. This process has been investigated in this work that aimed to determine the overall quality of groundwater in the zone occupied by the cemetery. The fluorescence spectrometry X-ray Energy Dispersive (EDXRF technique was used for groundwater chemical characterization. Five monitoring wells were constructed according to Brazilian norms. The water level fluctuation, the potentiometric surface and the concentrations of the elements calcium, copper, iron, phosphorus and silicon were estimated. The water level appeared quite shallow, ranging between 0.48 to 0.95 m in the dry season. The concentrations range for calcium varied from 4.65 to 17.85 mg L-1, for copper 0.02 ± 0.29 mg L-1, iron 0.57 to 15.96 mg L-1, phosphorus 12.00 to 13.98 mg L-1, and silicon 35.55 to 79.12 mg L-1. It is concluded that the use of EDXRF techniques proved to be rapid and efficient for monitoring the constituents in the groundwater collected in wells under the influence of graveyard in silt-clay soil.

  10. An Energy-Dispersive X-Ray Fluorescence Spectrometry and Monte Carlo simulation study of Iron-Age Nuragic small bronzes ("Navicelle") from Sardinia, Italy

    Science.gov (United States)

    Schiavon, Nick; de Palmas, Anna; Bulla, Claudio; Piga, Giampaolo; Brunetti, Antonio

    2016-09-01

    A spectrometric protocol combining Energy Dispersive X-Ray Fluorescence Spectrometry with Monte Carlo simulations of experimental spectra using the XRMC code package has been applied for the first time to characterize the elemental composition of a series of famous Iron Age small scale archaeological bronze replicas of ships (known as the ;Navicelle;) from the Nuragic civilization in Sardinia, Italy. The proposed protocol is a useful, nondestructive and fast analytical tool for Cultural Heritage sample. In Monte Carlo simulations, each sample was modeled as a multilayered object composed by two or three layers depending on the sample: when all present, the three layers are the original bronze substrate, the surface corrosion patina and an outermost protective layer (Paraloid) applied during past restorations. Monte Carlo simulations were able to account for the presence of the patina/corrosion layer as well as the presence of the Paraloid protective layer. It also accounted for the roughness effect commonly found at the surface of corroded metal archaeological artifacts. In this respect, the Monte Carlo simulation approach adopted here was, to the best of our knowledge, unique and enabled to determine the bronze alloy composition together with the thickness of the surface layers without the need for previously removing the surface patinas, a process potentially threatening preservation of precious archaeological/artistic artifacts for future generations.

  11. Exploring in vivo violacein biosynthesis by application of multivariate curve resolution on fused UV-VIS absorption, fluorescence, and liquid chromatography-mass spectrometry data.

    Science.gov (United States)

    Dantas, Clecio; Tauler, Romà; Ferreira, Márcia Miguel Castro

    2013-02-01

    In this work, the application of multivariate curve resolution-alternating least squares (MCR-ALS) is proposed for extracting information from multitechnique fused multivariate data (UV-VIS absorption, fluorescence, and liquid chromatography-mass spectrometry) gathered during the biosynthesis of violacein pigment. Experimental data sets were pretreated and arranged in a row-wise augmented data matrix before their chemometric investigation. Five different chemical components were resolved. Kinetic and spectral information about these components were obtained and their relationship with violacein biosynthesis was established. Three new chemical compounds with molar masses of 453, 465, and 479 u, until now not reported in the literature, were identified and proposed as intermediates in the biosynthesis of other indolocarbazoles. The precursor (tryptophan), one intermediate (deoxyviolacein), and the final product (violacein) of violacein biosynthesis were identified and characterized using the proposed approach. The chemometric procedure based on the MCR-ALS method has proved to be a powerful tool to investigate violacein biosynthesis and its application can be easily extended to the study of other bioprocesses.

  12. On-line high-performance liquid chromatography-fluorescence detection-electrospray ionization-mass spectrometry profiling of human milk oligosaccharides derivatized with 2-aminoacridone.

    Science.gov (United States)

    Galeotti, Fabio; Coppa, Giovanni V; Zampini, Lucia; Maccari, Francesca; Galeazzi, Tiziana; Padella, Lucia; Santoro, Lucia; Gabrielli, Orazio; Volpi, Nicola

    2012-11-01

    A high-resolution normal-phase high-performance liquid chromatography-fluorescence detection-electrospray ionization-mass spectrometry separation and structural characterization of the main oligosaccharides along with lactose from human milk samples is described. A total of 22 commercially available oligosaccharides were fluorotagged with 2-aminoacridone and separated on an amide column and identified on the basis of their retention times and mass spectra. Derivatized species having mass lower than approximately 800 to 900 exhibited mainly [M-H](-1) anions, oligomers with mass up to approximately 1000 to 1100 were represented by both [M-H](-1) and [M-2H](-2) anions, and oligomers greater than approximately 1200 to 1300 were characterized by a charge state of -3. Furthermore, the retention times were directly related to the glycans' molecular mass. Human milk samples from the four groups of donors (Se±/Le±) were analyzed for their composition and amount of free oligosaccharides after rapid and simple prepurification and derivatization steps also in the presence of lactose in high content. This analytical approach enabled us to perform the determination of species not detected by traditional techniques, such as sialic acid, as well as of species present in low content easily mistaken with other peaks. Finally, labeled human milk oligosaccharides were analyzed without any interference from excess fluorophore or interference from proteins, peptides, salts, and other impurities normally present in this complex biological fluid.

  13. Analysis of total and dissolved heavy metals in surface water of a Mexican polluted river by total reflection X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zarazua, G. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico)]. E-mail: gzo@nuclear.inin.mx; Avila-Perez, P. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Tejeda, S. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Barcelo-Quintal, I. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Mexico, D.F. (Mexico); Martinez, T. [Universidad Nacional Autonoma de Mexico, Facultad de Quimica, Mexico, D.F. (Mexico)

    2006-11-15

    The present area of study is located in the Upper Course of the Lerma River (UCLR). The Lerma is one of the most important rivers of Mexico, where it drains highly populated and industrialized regions. The aim of the present study is to determine the heavy metal concentration of Cr, Mn, Fe, Cu and Pb in dissolved and total phases of the UCLR by means of Total Reflection X-ray Fluorescence Spectrometry (TXRF). The surface water samples were collected at 8 sites distributed following the stream flow direction of the river. Four sampling campaigns were carried out in each site in a 1-year period. A sample preparation method was applied in order to obtain the total and dissolved fraction and to destroy the organic matter. The total heavy metal average concentration decrease in the following order: Fe (2566 {mu}g/L) > Mn (300 {mu}g/L) > Cu (66 {mu}g/L) > Cr (21 {mu}g/L) > Pb (15 {mu}g/L). In general, the heavy metal concentrations in water of the UCLR are below the maximum permissible limits.

  14. Analysis of total and dissolved heavy metals in surface water of a Mexican polluted river by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Zarazua, G.; Ávila-Pérez, P.; Tejeda, S.; Barcelo-Quintal, I.; Martínez, T.

    2006-11-01

    The present area of study is located in the Upper Course of the Lerma River (UCLR). The Lerma is one of the most important rivers of Mexico, where it drains highly populated and industrialized regions. The aim of the present study is to determine the heavy metal concentration of Cr, Mn, Fe, Cu and Pb in dissolved and total phases of the UCLR by means of Total Reflection X-ray Fluorescence Spectrometry (TXRF). The surface water samples were collected at 8 sites distributed following the stream flow direction of the river. Four sampling campaigns were carried out in each site in a 1-year period. A sample preparation method was applied in order to obtain the total and dissolved fraction and to destroy the organic matter. The total heavy metal average concentration decrease in the following order: Fe (2566 μg/L) > Mn (300 μg/L) > Cu (66 μg/L) > Cr (21 μg/L) > Pb (15 μg/L). In general, the heavy metal concentrations in water of the UCLR are below the maximum permissible limits.

  15. 原子荧光光谱法测定环境空气中锑%Antimony Determination by Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    顾志勇

    2014-01-01

    采用过氯乙烯滤膜采集环境空气中锑,盐酸-氢氟酸混酸体系微波消解滤膜,原子荧光光谱法测定锑。方法前处理操作过程简单、省时、酸用量少、环境污染小,方法的灵敏度和准确度都有很大的提高。采样体积为300L时,空气中锑的最低检出质量浓度为0.002mg/m3。%Antimony in air was sampled using perchloroethylene filter.The filter was dipped into hydrochloric acid and hydrofluoric acid system and digested by microwave.Atomic fluorescence spectrometry was used to detect anti-mony after.This process is simple and time-saving with easy pretreatment,less amount of acid,and less negative impacts on environment.In addition,the accuracy and precision of the process is better than previous methods. The detection limit of antimony in air is 0.002mg/m3 when the volume of air sample is 300 liters when this process was applied.

  16. Studies on the metabolism and toxicological detection of the amphetamine-like anorectic mefenorex in human urine by gas chromatography-mass spectrometry and fluorescence polarization immunoassay.

    Science.gov (United States)

    Kraemer, T; Vernaleken, I; Maurer, H H

    1997-11-21

    Studies on the metabolism and on the toxicological analysis of mefenorex [R,S-N-(3-chloropropyl)-alpha-methylphenethylamine, MF] using gas chromatography-mass spectrometry (GC-MS) and fluorescence polarization immunoassay (FPIA) are described. The metabolites were identified in urine samples of volunteers by GC-MS. Besides MF, thirteen metabolites including amphetamine (AM) could be identified and three partially overlapping metabolic pathways could be postulated. For GC-MS detection, the systematic toxicological analysis procedure including acid hydrolysis, extraction at pH 8-9 and acetylation was suitable (detection limits 50 ng/ml for MF and 100 ng/ml for AM). Excretion studies showed, that only AM but neither MF nor its specific metabolites were detectable between 32 and 68 h after ingestion of 80 mg of MF. Therefore, misinterpretation can occur. The Abbott TDx FPIA amphetamine/methamphetamine II gave positive results up to 68 h. All the positive immunoassay results could be confirmed by the described GC-MS procedure.

  17. [Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of Pangxidong Composite Granitoid Pluton and Its Implications for Magmatic Differentiation].

    Science.gov (United States)

    Zeng, Chang-yu; Ding, Ru-xin; Li, Hong-zhong; Zhou, Yong-zhang; Niu, Jia; Zhang, Jie-tang

    2015-11-01

    Pangxidong composite granitoid pluton located in the southwestern margin of Yunkai massif. The metamorphic grade of this pluton increases from outside to inside, that is, banded-augen granitic gneisses, gneissoid granites and granites distribute in order from edge to core. X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry are conducted to study the geochemical characteristics of the three types of rocks. The result shows that all the three types of rocks are peraluminous rocks and their contents of main elements and rare earth elements change gradually. From granitic gneisses to granites, the contents of Al₂O₃, CaO, MgO, TiO₂, total rare earth elements and light rare earth elements increase, but the contents of SiO₂ and heavy rare earth elements decrease. It is suggested that the phylogenetic relationship exists between granitic gneisses, gneissoid granites and granites during the multi-stage tectonic evolution process. Furthermore, the remelting of metamorphosed supracrustal rocks in Yunkai massif is probably an important cause of granitoid rocks forming. The evolutionary mechanism is probably that SiO₂ and heavy rare earth elements were melt out from the protolith and gradually enriched upward, but Al₂O₃, CaO, MgO, TiO₂ and light rare earth elements enriched downward.

  18. Parallel microscope-based fluorescence, absorbance and time-of-flight mass spectrometry detection for high performance liquid chromatography and determination of glucosamine in urine.

    Science.gov (United States)

    Xiong, Bo; Wang, Ling-Ling; Li, Qiong; Nie, Yu-Ting; Cheng, Shuang-Shuang; Zhang, Hui; Sun, Ren-Qiang; Wang, Yu-Jiao; Zhou, Hong-Bin

    2015-11-01

    A parallel microscope-based laser-induced fluorescence (LIF), ultraviolet-visible absorbance (UV) and time-of-flight mass spectrometry (TOF-MS) detection for high performance liquid chromatography (HPLC) was achieved and used to determine glucosamine in urines. First, a reliable and convenient LIF detection was developed based on an inverted microscope and corresponding modulations. Parallel HPLC-LIF/UV/TOF-MS detection was developed by the combination of preceding Microscope-based LIF detection and HPLC coupled with UV and TOF-MS. The proposed setup, due to its parallel scheme, was free of the influence from photo bleaching in LIF detection. Rhodamine B, glutamic acid and glucosamine have been determined to evaluate its performance. Moreover, the proposed strategy was used to determine the glucosamine in urines, and subsequent results suggested that glucosamine, which was widely used in the prevention of the bone arthritis, was metabolized to urines within 4h. Furthermore, its concentration in urines decreased to 5.4mM at 12h. Efficient glucosamine detection was achieved based on a sensitive quantification (LIF), a universal detection (UV) and structural characterizations (TOF-MS). This application indicated that the proposed strategy was sensitive, universal and versatile, and it was capable of improved analysis, especially for analytes with low concentrations in complex samples, compared with conventional HPLC-UV/TOF-MS.

  19. [Determination of arsenic, mercury and selenium in Gynostemma pentaphyllum and rhizospheric soil samples collected from different regions by hydride generation atomic fluorescence spectrometry].

    Science.gov (United States)

    Wang, Jing; Xiao, Ya-ping; Liang, Xiao-qing; Shao, Xian-hui; Zhang, Ke

    2012-03-01

    The contents of arsenic (As), mercury (Hg) and selenium (Se) in Gynostemma pentaphyllum and rhizospheric soil samples collected from seven provinces were determined, through the optimization of the hydride generation atomic fluorescence spectrometry working conditions. The results show that: the contents of As, Hg and Se in Gynostemma pentaphyllum from seven provinces revealed large differences, but compared with the limits of the two kinds of heavy metal element: As and Hg set by the Green Trade Standards of Importing & Exporting Medicinal Plants & Preparations (As Gynostemma pentaphyllum samples are both lower than them. The Se content in Gynostemma pentaphyllum samples and in rhizospheric soil samples revealed significant correlation, and as a result, the Gynostemma pentaphyllum from the Fu Xi area Enshi in Hu Bei province had obviously higher Se content than others in the 6 provinces. From this study, a preliminary conclusion can be drawn that Se in Gynostemma pentaphyllum is mainly from the soil, moreover, the As and Hg show the difference from Se, possibly they are still affected by the dry and wet deposition of atmospheric aerosols.

  20. An evaluation of the bioaccessibility of arsenic in corn and rice samples based on cloud point extraction and hydride generation coupled to atomic fluorescence spectrometry.

    Science.gov (United States)

    Castor, José Martín Rosas; Portugal, Lindomar; Ferrer, Laura; Hinojosa-Reyes, Laura; Guzmán-Mar, Jorge Luis; Hernández-Ramírez, Aracely; Cerdà, Víctor

    2016-08-01

    A simple, inexpensive and rapid method was proposed for the determination of bioaccessible arsenic in corn and rice samples using an in vitro bioaccessibility assay. The method was based on the preconcentration of arsenic by cloud point extraction (CPE) using o,o-diethyldithiophosphate (DDTP) complex, which was generated from an in vitro extract using polyethylene glycol tert-octylphenyl ether (Triton X-114) as a surfactant prior to its detection by atomic fluorescence spectrometry with a hydride generation system (HG-AFS). The CPE method was optimized by a multivariate approach (two-level full factorial and Doehlert designs). A photo-oxidation step of the organic species prior to HG-AFS detection was included for the accurate quantification of the total As. The limit of detection was 1.34μgkg(-1) and 1.90μgkg(-1) for rice and corn samples, respectively. The accuracy of the method was confirmed by analyzing certified reference material ERM BC-211 (rice powder). The corn and rice samples that were analyzed showed a high bioaccessible arsenic content (72-88% and 54-96%, respectively), indicating a potential human health risk.

  1. Comparative Study of Metal Quantification in Neurological Tissue Using Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry Imaging and X-ray Fluorescence Microscopy.

    Science.gov (United States)

    Davies, Katherine M; Hare, Dominic J; Bohic, Sylvain; James, Simon A; Billings, Jessica L; Finkelstein, David I; Doble, Philip A; Double, Kay L

    2015-07-07

    Redox-active metals in the brain mediate numerous biochemical processes and are also implicated in a number of neurodegenerative diseases. A number of different approaches are available for quantitatively measuring the spatial distribution of biometals at an image resolution approaching the subcellular level. Measured biometal levels obtained using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS; spatial resolution 15 μm × 15 μm) were within the range of those obtained using X-ray fluorescence microscopy (XFM; spatial resolution 2 μm × 7 μm) and regional changes in metal concentration across discrete brain regions were replicated to the same degree. Both techniques are well suited to profiling changes in regional biometal distribution between healthy and diseased brain tissues, but absolute quantitation of metal levels varied significantly between methods, depending on the metal of interest. Where all possible variables affect metal levels, independent of a treatment/phenotype are controlled, either method is suitable for examining differences between experimental groups, though, as with any method for imaging post mortem brain tissue, care should be taken when interpreting the total metal levels with regard to physiological concentrations.

  2. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    Science.gov (United States)

    Van Pevenage, J.; Verhaeven, E.; Vekemans, B.; Lauwers, D.; Herremans, D.; De Clercq, W.; Vincze, L.; Moens, L.; Vandenabeele, P.

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661-1722), and the samples of group B produced under emperor Qianlong (1735-1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated.

  3. Speciation analysis of inorganic arsenic in coal samples by microwave-assisted extraction and high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Sun, Mei; Liu, Guijian; Wu, Qianghua; Liu, Wenqi

    2013-03-15

    A new method was developed for the speciation analysis of inorganic arsenic in coal samples by high performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry after microwave-assisted extraction. Effective extract of As(III) and As(V) in coal sample was achieved by 1.0 mol L(-1)H₃PO₄ and 0.1 mol L(-1)ascorbic acid. Under the optimized conditions, the limits of detection (LOD) were 0.01 μg L(-1) and 0.02 μg L(-1), the relative standard deviations (RSD) were 2.4% and 3.3% (c=10.0 μg L(-1), n=7), recoveries were 102.5% and 96.5% for As(III) and As(V). The proposed method was successfully applied for the determination of speciation of inorganic arsenic in coal samples and GBW11117 coal standard reference material with complex matrix. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. 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

    Science.gov (United States)

    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- 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.

  5. 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.

  6. Characterization by Total Reflection X-ray Fluorescence Spectrometry of filtered water into the cave under the Sun Pyramid in Teotihuacan City

    Science.gov (United States)

    Martinez, T.; Zarazua, G.; Avila-Perez, P.; Juarez, F.; Cabrera, L.; Martinez, G.

    2008-12-01

    Teotihuacan (50 km north-east Mexico City) was the most important ancient city in Mesoamerica and it flourished 200-750 AC. It is situated in the central part of the Valley of Teotihuacan, in Central México. This study was carried out in the 102 m-long cave under the largest single construction, the massive Sun Pyramid, being located on the east side of the "Avenue of the Dead", in the northern half-part of the city. The study shows the results of Total Reflection X-ray Fluorescence Spectrometry analysis and other techniques of a water sample obtained from the inside of the cave. The inside temperature ranged between 19 and 22 °C; relative humidity was between 98 and 99.3%; water-dropping velocity (water de-sorption capability) was 13.5 μL min - 1 . Water samples from wells around the site were analyzed too. Metal concentration in all of the water samples matches the characteristics of the sampling site, well's depth, soil and minerals.

  7. Evaluation of hydrodynamic chromatography coupled with UV-visible, fluorescence and inductively coupled plasma mass spectrometry detectors for sizing and quantifying colloids in environmental media.

    Directory of Open Access Journals (Sweden)

    Allan Philippe

    Full Text Available In this study, we evaluated hydrodynamic chromatography (HDC coupled with inductively coupled plasma mass spectrometry (ICP-MS for the analysis of nanoparticles in environmental samples. Using two commercially available columns (Polymer Labs-PDSA type 1 and 2, a set of well characterised calibrants and a new external time marking method, we showed that flow rate and eluent composition have few influence on the size resolution and, therefore, can be adapted to the sample particularity. Monitoring the agglomeration of polystyrene nanoparticles over time succeeded without observable disagglomeration suggesting that even weak agglomerates can be measured using HDC. Simultaneous determination of gold colloid concentration and size using ICP-MS detection was validated for elemental concentrations in the ppb range. HDC-ICP-MS was successfully applied to samples containing a high organic and ionic background. Indeed, online combination of UV-visible, fluorescence and ICP-MS detectors allowed distinguishing between organic molecules and inorganic colloids during the analysis of Ag nanoparticles in synthetic surface waters and TiO₂ and ZnO nanoparticles in commercial sunscreens. Taken together, our results demonstrate that HDC-ICP-MS is a flexible, sensitive and reliable method to measure the size and the concentration of inorganic colloids in complex media and suggest that there may be a promising future for the application of HDC in environmental science. Nonetheless the rigorous measurements of agglomerates and of matrices containing natural colloids still need to be studied in detail.

  8. Enhanced characterization of oil sands acid-extractable organics fractions using electrospray ionization-high-resolution mass spectrometry and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Bauer, Anthony E; Frank, Richard A; Headley, John V; Peru, Kerry M; Hewitt, L Mark; Dixon, D George

    2015-05-01

    The open pit oil sands mining operations north of Fort McMurray, Alberta, Canada, are accumulating tailings waste at a rate approximately equal to 4.9 million m(3) /d. Naphthenic acids are among the most toxic components within tailings to aquatic life, but structural components have largely remained unidentified. In the present study, electrospray ionization high-resolution mass spectrometry (ESI-HRMS) and synchronous fluorescence spectroscopy (SFS) were used to characterize fractions derived from the distillation of an acid-extractable organics (AEO) mixture isolated from oil sands process-affected water (OSPW). Mean molecular weights of each fraction, and their relative proportions to the whole AEO extract, were as follows: fraction 1: 237 Da, 8.3%; fraction 2: 240 Da, 23.8%; fraction 3: 257 Da, 26.7%; fraction 4: 308 Da, 18.9%; fraction 5: 355 Da, 10.0%. With increasing mean molecular weight of the AEO fractions, a concurrent increase occurred in the relative abundance of nitrogen-, sulfur-, and oxygen-containing ions, double-bond equivalents, and degree of aromaticity. Structures present in the higher-molecular-weight fractions (fraction 4 and fraction 5) suggested the presence of heteroatoms, dicarboxyl and dihydroxy groups, and organic acid compounds with the potential to function as estrogens. Because organic acid compositions become dominated by more recalcitrant, higher-molecular-weight acids during natural degradation, these findings are important in the context of oil sands tailings pond water remediation.

  9. Organic solvent-free reversed-phase ion-pairing liquid chromatography coupled to atomic fluorescence spectrometry for organoarsenic species determination in several matrices.

    Science.gov (United States)

    Monasterio, Romina P; Londonio, Juan A; Farias, Silvia S; Smichowski, Patricia; Wuilloud, Rodolfo G

    2011-04-27

    A novel method has been developed to determine As-containing animal feed additives including roxarsone (ROX), p-arsanilic acid (p-ASA) and nitarsone (NIT), as well as other organic As species (dimethylarsonic acid (DMAA) and monomethylarsonic acid (MMAA)) by ion-pairing high-performance liquid chromatography coupled to hydride generation atomic fluorescence spectrometry (IP-HPLC-HG-AFS). A simple isocratic reversed-phase (RP) HPLC method with a mobile phase containing citric acid and sodium hexanesulfonate (pH 2.0) was developed using a C(18) column. The use of an organic solvent free mobile phase turns this methodology into an environmentally friendly alternative. Several ion pair forming agents, such as sodium hexanesulfonate, tetrabutylammonium bisulfate and perfluoroheptanoic acid, were studied. The limits of detection for As species were calculated in standard solution and resulted to be 0.2, 0.5, 0.6, 1.6, and 1.6 μg As L(-1) for MMAA, DMAA, p-ASA, ROX and NIT, respectively. This method exhibited convenient operation, high sensitivity and good repeatability. It was applied to As speciation in different samples including arugula, dog food, dog urine and chicken liver.

  10. Dual-mode chemical vapor generation for simultaneous determination of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry.

    Science.gov (United States)

    Wang, Yu; Xu, Kailai; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-05-21

    A dual-mode chemical vapor generation integrating hydride generation and photochemical vapor generation was developed for simultaneous multi-element analysis of hydride-forming and non-hydride-forming elements by atomic fluorescence spectrometry. Four elements were selected as model elements of hydride-forming (As, Cd) and non-hydride-forming (Ni, Fe) elements to validate this proposed method. Standard or sample solutions were separately pumped to mix with tetrahydroborate, and concentrated formic acid and ammonia, and then directed to a hydride generator and a photochemical reactor to realize simultaneous hydride generation and photochemical vapor generation, respectively. Optimum conditions for dual-mode chemical vapor generation were carefully investigated. Under the optimized conditions, limits of detection of 0.05, 0.008, 0.8 and 0.1 μg L(-1) were obtained for As, Cd, Fe and Ni, respectively. The precisions were 5.0, 5.5, 4.3 and 4.5% (n = 6, RSDs) for 2 μg L(-1) of As, 1 μg L(-1) of Cd, 50 μg L(-1) of Fe and 10 μg L(-1) of Ni, respectively. This method was validated for accuracy with three certified reference water samples and applied to the simultaneous determination of these elements in a tap water sample with spike recoveries in the range of 95-99%.

  11. Quantitative analysis of phenylalanine, tyrosine, tryptophan and kynurenine in rat model for tauopathies by ultra-high performance liquid chromatography with fluorescence and mass spectrometry detection.

    Science.gov (United States)

    Galba, Jaroslav; Michalicova, Alena; Parrak, Vojtech; Novak, Michal; Kovac, Andrej

    2016-01-01

    We developed and validated a simple and sensitive ultra-high performance liquid chromatography (UHPLC) method for the analysis of phenylalanine (Phe), tyrosine (Tyr), tryptophan (Trp) and kynurenine (Kyn) in rat plasma. Analytes were separated on Acquity UPLC HSS T3 column (2.1 mm×50 mm, 1.8 μm particle size) using a 4 min ammonium acetate (pH 5) gradient and detected by fluorescence and positive ESI mass spectrometry. Sample preparation involved dilution of plasma, deproteinization by trichloroacetic acid and centrifugation. The procedure was validated in compliance with the FDA guideline. The limits of quantification (LOQ) were 0.3 μM for Kyn and from 1.5 to 3 μM for Phe, Tyr, Trp. The method showed excellent linearity with regression coefficients higher than 0.99. The accuracy was within the range of 86-108%. The inter-day precision (n=5 days), expressed as % RSD, was in the range 1-13%. The benefit of using UHPLC is a short analysis period and thus, a very good sample throughput. Using this method, we analyzed plasma samples and detected significant changes of Kyn and Phe in transgenic rat model for tauopathies.

  12. 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.)

  13. Masking Agents Evaluation for Lead Determination by Flow Injection-Hydride Generation-Atomic Fluorescence Spectrometry Technique: Effect of KI, L-Cysteine, and 1,10-Phenanthroline.

    Science.gov (United States)

    Beltrán, Blanca G; Leal, Luz O; Ferrer, Laura; Cerdà, Víctor

    2016-01-01

    Hydride generation (HG) of lead technique presents interferences from foreign ions of complex matrix samples. In order to minimize these interferences, the effect of masking agents such as KI, L-cysteine, and 1,10-phenanthroline was studied in the absence and in the presence of selected interfering species (As, Cr, Cu, and Fe). Different modes of addition of masking agents were accomplished, that is, to either sample or KBH4 reducing solution. The lead determinations were performed using a flow injection analysis (FIA) system coupled to HG and atomic fluorescence spectrometry (AFS). The linearity of calibration curves (1-10 μg Pb L(-1)) was not affected by the addition of the masking agents. The use of KI in the reducing solution diminished interferences from concentrations of As and Cu, while 1,10-phenanthroline showed a positive effect on the interference by As. Moreover, Cr and Cu appeared to be the most serious interfering ions for plumbane (PbH4), because they drastically reduced the analytical signal of lead. Fe did not present any interference under the employed experimental conditions, even at high levels. The accuracy was established through the analysis of certified reference material (i.e., BCR-610, groundwater) using KI as masking agent. The detection limit reached by FIA-HG-AFS proposed methodology was 0.03 μg Pb L(-1).

  14. Study of heavy metals in wild edible mushrooms under different pollution conditions by X-ray fluorescence spectrometry.

    Science.gov (United States)

    Carvalho, M L; Pimentel, A C; Fernandes, B

    2005-07-01

    In this work we studied and compared the metal uptake in edible mushrooms (Lepiota procera, Boletus badius, Boletus edulis, Tricholoma equestry, Lactarius deliciosus, Cantarelus tubalformis and Cantarelus edulis), relative to sampling sites submitted to different pollution conditions: car traffic, soil pollution due to pesticides and fertilizers used in old vineyards, and incineration of hospital waste. Soil was also collected in some places, and its content was correlated to the corresponding one in some mushrooms species. All samples, without any chemical treatment, were analyzed by an X-ray fluorescence set-up. This technique is based on a monochromatic X-ray beam ionizing the atoms of the sample. Following this ionization, the emitted radiation is characteristic of the element, allowing its identification and quantification. Vineyards are normally submitted to very high amounts of sulfating, containing high copper concentrations. This metal is accumulated on the soil, and can be up-taken by vegetation. Very high levels of Fe and Cu were found in Lepiota procera species in old vineyards. Zinc was found to be always higher than Cu by factors ranging from 1.5 to 8 in clean wood taken as a reference for the whole analyzed species, while in old vineyards the ratio Zn/Cu reach 0.25 for Lepiota procera. This is correlated to the soil content for both elements. In addition, pollution induced by car traffic was checked in some samples, collected in the proximity of highways. Pb was the main contaminant in these areas, and presenting values 10 times higher than the corresponding ones in sites not submitted to pollution, for some species. Mushrooms contamination due to incineration of hospital waste was also studied, but we did not observe any contamination involving heavy metals in the several analyzed species around these areas. This is in agreement with what was expected, taking into account that hospital waste is mostly organic and, in principle, no heavy metals would

  15. Identifying acetylated lignin units in non-wood fibers using pyrolysis-gas chromatography/mass spectrometry.

    Science.gov (United States)

    del Río, José C; Gutiérrez, Ana; Martínez, Angel T

    2004-01-01

    A series of non-wood plant fibers, namely kenaf, jute, sisal and abaca, have been analyzed upon pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) of the whole material. The pyrolysis products mainly arise from the carbohydrate and lignin moieties of the fibers. The lignin-derived phenols belonged to the p-hydroxyphenylpropanoid (H), guaiacylpropanoid (G) and syringylpropanoid (S) structures, and showed a high S/G ratio of between 2.0 and 5.4, the highest corresponding to kenaf. Among the lignin-derived phenols released, small amounts of sinapyl and coniferyl acetates (in both cis- and trans-forms) were identified for the first time upon Py-GC/MS of lignocellulosic materials. Acetylation of the sinapyl and coniferyl alcohols was at the gamma-position of the side chain. The release of these alcohols derived from intact acetylated lignin units upon pyrolysis seems to indicate that the native lignin in the fibers selected for this study is at least partially acetylated. Sinapyl (and coniferyl) acetates have recently been suggested to be authentic lignin precursors involved in the polymerization of lignin along with the normal sinapyl and coniferyl alcohols. Py-GC/MS will offer a convenient and rapid tool for analyzing naturally acetylated lignins, as well as to screen plant materials for the presence of acetylated units in lignin.

  16. Two novel fluorescent calix[4]arene derivatives with benzoazole units in 1,3-alternate conformation for selective recognition to Fe~(3+) and Cr~(3+)

    Institute of Scientific and Technical Information of China (English)

    He Wen Wang; Ya Qing Feng; Chen Chen; Jin Qiang Xue

    2009-01-01

    Two novel fluorescent calix[4]arene derivatives 1a and 1b with benzoxazole or benzothiazole units in 1,3-alternate conformation have been synthesized and characterized by IR, ~1H NMR, ~(13)C NMR and MS. Their complexation properties to different heavy and transition metal ions have been studied by UV-vis spectroscopy and fluorescence spectrometer. Compounds la and lb show selective recognition to Fe~(3+) and Cr~(3+).

  17. Airborne intercomparison of HOx measurements using laser-induced fluorescence and chemical ionization mass spectrometry during ARCTAS

    Directory of Open Access Journals (Sweden)

    J. H. Crawford

    2012-08-01

    Full Text Available The hydroxyl (OH and hydroperoxyl (HO2 radicals, collectively called HOx, play central roles in tropospheric chemistry. Accurate measurements of OH and HO2 are critical to examine our understanding of atmospheric chemistry. Intercomparisons of different techniques for detecting OH and HO2 are vital to evaluate their measurement capabilities. Three instruments that measured OH and/or HO2 radicals were deployed on the NASA DC-8 aircraft throughout Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS in the spring and summer of 2008. One instrument was the Penn State Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS for OH and HO2 measurements based on Laser-Induced Fluorescence (LIF spectroscopy. A second instrument was the NCAR Selected-Ion Chemical Ionization Mass Spectrometer (SI-CIMS for OH measurement. A third instrument was the NCAR Peroxy Radical Chemical Ionization Mass Spectrometer (PeRCIMS for HO2 measurement. Formal intercomparison of LIF and CIMS was conducted for the first time on a same aircraft platform. The three instruments were calibrated by quantitative photolysis of water vapor by ultraviolet (UV light at 184.9 nm with three different calibration systems. The absolute accuracies were ±32% (2σ for the LIF instrument, ±65% (2σ for the SI-CIMS instrument, and ±50% (2σ for the PeRCIMS instrument. In general, good agreement was obtained between the CIMS and LIF measurements of both OH and HO2 measurements. Linear regression of the entire data set yields [OH]CIMS = 0.89 × [OH]LIF + 2.8 × 104 cm−3 with a correlation coefficient r2 = 0.72 for OH, and [HO2]CIMS = 0.86 × [HO2]LIF + 3.9 parts per trillion by volume (pptv, equivalent to pmol mol−1 with a correlation coefficient r2 = 0.72 for HO2. In general, the difference between CIMS and LIF instruments for OH and HO2 measurements can be explained by their combined measurement uncertainties. Comparison with box model results shows some

  18. Determining the Performance of Fluorescence Molecular Imaging Devices Using Traceable Working Standards With SI Units of Radiance.

    Science.gov (United States)

    Zhu, Banghe; Rasmussen, John C; Litorja, Maritoni; Sevick-Muraca, Eva M

    2016-03-01

    To date, no emerging preclinical or clinical near-infrared fluorescence (NIRF) imaging devices for noninvasive and/or surgical guidance have their performances validated on working standards with SI units of radiance that enable comparison or quantitative quality assurance. In this work, we developed and deployed a methodology to calibrate a stable, solid phantom for emission radiance with International System of Units (SI) units of mW ·sr(-1) ·cm(-2) for use in characterizing the measurement sensitivity of ICCD and IsCMOS detection, signal-to-noise ratio, and contrast. In addition, at calibrated radiances, we assess transverse and lateral resolution of ICCD and IsCMOS camera systems. The methodology allowed demonstration of superior SNR of the ICCD over the IsCMOS technology and superior resolution of the IsCMOS over the ICCD approach. Contrast depended upon the camera settings (binning and integration time) and gain of intensifier. Finally, because the architecture of CMOS and CCD camera systems results in vastly different performance, we comment on the utility of these technologies for small animal imaging as well as clinical applications for noninvasive and surgical guidance.

  19. Monte Carlo-based fluorescence molecular tomography reconstruction method accelerated by a cluster of graphic processing units.

    Science.gov (United States)

    Quan, Guotao; Gong, Hui; Deng, Yong; Fu, Jianwei; Luo, Qingming

    2011-02-01

    High-speed fluorescence molecular tomography (FMT) reconstruction for 3-D heterogeneous media is still one of the most challenging problems in diffusive optical fluorescence imaging. In this paper, we propose a fast FMT reconstruction method that is based on Monte Carlo (MC) simulation and accelerated by a cluster of graphics processing units (GPUs). Based on the Message Passing Interface standard, we modified the MC code for fast FMT reconstruction, and different Green's functions representing the flux distribution in media are calculated simultaneously by different GPUs in the cluster. A load-balancing method was also developed to increase the computational efficiency. By applying the Fréchet derivative, a Jacobian matrix is formed to reconstruct the distribution of the fluorochromes using the calculated Green's functions. Phantom experiments have shown that only 10 min are required to get reconstruction results with a cluster of 6 GPUs, rather than 6 h with a cluster of multiple dual opteron CPU nodes. Because of the advantages of high accuracy and suitability for 3-D heterogeneity media with refractive-index-unmatched boundaries from the MC simulation, the GPU cluster-accelerated method provides a reliable approach to high-speed reconstruction for FMT imaging.

  20. Some aspects of analytical chemistry as applied to water quality assurance techniques for reclaimed water: The potential use of X-ray fluorescence spectrometry for automated on-line fast real-time simultaneous multi-component analysis of inorganic pollutants in reclaimed water

    Science.gov (United States)

    Ling, A. C.; Macpherson, L. H.; Rey, M.

    1981-01-01

    The potential use of isotopically excited energy dispersive X-ray fluorescence (XRF) spectrometry for automated on line fast real time (5 to 15 minutes) simultaneous multicomponent (up to 20) trace (1 to 10 parts per billion) analysis of inorganic pollutants in reclaimed water was examined. Three anionic elements (chromium 6, arsenic and selenium) were studied. The inherent lack of sensitivity of XRF spectrometry for these elements mandates use of a preconcentration technique and various methods were examined, including: several direct and indirect evaporation methods; ion exchange membranes; selective and nonselective precipitation; and complexation processes. It is shown tha XRF spectrometry itself is well suited for automated on line quality assurance, and can provide a nondestructive (and thus sample storage and repeat analysis capabilities) and particularly convenient analytical method. Further, the use of an isotopically excited energy dispersive unit (50 mCi Cd-109 source) coupled with a suitable preconcentration process can provide sufficient sensitivity to achieve the current mandated minimum levels of detection without the need for high power X-ray generating tubes.

  1. Modern aerial gamma-ray spectrometry and regional potassium map of the conterminous United States

    Science.gov (United States)

    Duval, Joseph S.

    1990-01-01

    Aerial gamma-ray surveys of the natural environment measure the flux of gamma rays produced by the radioactive decay of 40K, 214Bi, and 208Tl in the upper 10–20 cm of surface materials. 40K is a radioactive potassium isotope which can be used to estimate the total amount of potassium in the soils and rocks. 214Bi is a decay product of the 238U radioactive decay series and is used to estimate the uranium concentrations, and 208Tl, a decay product of the 232Th radioactive decay series, is used to estimate thorium concentrations. Aerial gamma-ray data covering the 48 contiguous states of the United States have been compiled to produce maps showing the distributions of equivalent uranium, equivalent thorium, and potassium. This compilation involved processing the aerial survey data from about 470 1° × 2° quadrangle maps.

  2. Gold-coated silica as a preconcentration phase for the determination of total dissolved mercury in natural waters using atomic fluorescence spectrometry.

    Science.gov (United States)

    Leopold, Kerstin; Foulkes, Michael; Worsfold, Paul J

    2009-05-01

    A novel solid-phase preconcentration method is reported, using in-house gold-coated silica adsorbent packed in a microcolumn, for the determination of dissolved mercury in natural waters by atomic fluorescence spectrometry (AFS). The adsorbent was prepared by chemical reduction of a Au(III) solution with hydroxylamine in the presence of suspended silica particles. The resulting Au nanoparticles on the silica surface were highly efficient for adsorbing different mercury species from acidified waters without additional reagents. The acidified aqueous samples were passed over the microcolumn, either incorporated in a fully automated flow injection (FI) system directly coupled to the AFS or as part of a portable FI system for in situ preconcentration. After rinsing and drying of the column, Hg(0) was released by heating and directed to the AFS cell for quantification. The method offers significant advantages because no reagents are needed for species conversion, preconcentration, sample storage, or desorption and therefore the risk of contamination is minimized and blank values are lowered. This results in a low detection limit of 180 pg L(-1) using a sample volume of only 7 mL and good reproducibility, with relative standard deviations 90% in spiked river waters (spiked [Hg] = 0, 1, 5, 10 ng L(-1)), and the experimental value for the certified reference material ORMS-4 (elevated mercury in river water) was 22.3 +/- 2.6 ng Hg L(-1) which was in good agreement with the certified value of 22.0 +/- 1.6 ng Hg L(-1) (recovery = 101%). The method was successfully applied to seven different natural waters and wastewaters ([Hg] 0.5-4.6 ng L(-1)) from south west England.

  3. Arsenic fractionation in agricultural soil using an automated three-step sequential extraction method coupled to hydride generation-atomic fluorescence spectrometry.

    Science.gov (United States)

    Rosas-Castor, J M; Portugal, L; Ferrer, L; Guzmán-Mar, J L; Hernández-Ramírez, A; Cerdà, V; Hinojosa-Reyes, L

    2015-05-18

    A fully automated modified three-step BCR flow-through sequential extraction method was developed for the fractionation of the arsenic (As) content from agricultural soil based on a multi-syringe flow injection analysis (MSFIA) system coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS). Critical parameters that affect the performance of the automated system were optimized by exploiting a multivariate approach using a Doehlert design. The validation of the flow-based modified-BCR method was carried out by comparison with the conventional BCR method. Thus, the total As content was determined in the following three fractions: fraction 1 (F1), the acid-soluble or interchangeable fraction; fraction 2 (F2), the reducible fraction; and fraction 3 (F3), the oxidizable fraction. The limits of detection (LOD) were 4.0, 3.4, and 23.6 μg L(-1) for F1, F2, and F3, respectively. A wide working concentration range was obtained for the analysis of each fraction, i.e., 0.013-0.800, 0.011-0.900 and 0.079-1.400 mg L(-1) for F1, F2, and F3, respectively. The precision of the automated MSFIA-HG-AFS system, expressed as the relative standard deviation (RSD), was evaluated for a 200 μg L(-1) As standard solution, and RSD values between 5 and 8% were achieved for the three BCR fractions. The new modified three-step BCR flow-based sequential extraction method was satisfactorily applied for arsenic fractionation in real agricultural soil samples from an arsenic-contaminated mining zone to evaluate its extractability. The frequency of analysis of the proposed method was eight times higher than that of the conventional BCR method (6 vs 48 h), and the kinetics of lixiviation were established for each fraction.

  4. Label-Free and Separation-Free Atomic Fluorescence Spectrometry-Based Bioassay: Sensitive Determination of Single-Strand DNA, Protein, and Double-Strand DNA.

    Science.gov (United States)

    Chen, Piaopiao; Wu, Peng; Chen, Junbo; Yang, Peng; Zhang, Xinfeng; Zheng, Chengbin; Hou, Xiandeng

    2016-02-16

    Based on selective and sensitive determination of Hg(2+) released from mercury complex by cold vapor generation (CVG) atomic fluorescence spectrometry (AFS) using SnCl2 as a reductant, a novel label-free and separation-free strategy was proposed for DNA and protein bioassay. To construct the DNA bioassay platform, an Hg(2+)-mediated molecular beacon (hairpin) without labeling but possessing several thymine (T) bases at both ends was employed as the probe. It is well-known that Hg(2+) could trigger the formation of the hairpin structure through T-Hg(2+)-T connection. In the presence of a specific target, the hairpin structure could be broken and the captured Hg(2+) was released. Interestingly, it was found that SnCl2 could selectively reduce only free Hg(2+) to Hg(0) vapor in the presence of T-Hg(2+)-T complex, which could be separated from sample matrices for sensitive AFS detection. Three different types of analyte, namely, single-strand DNA (ssDNA), protein, and double-strand DNA (dsDNA), were investigated as the target analytes. Under the optimized conditions, this bioassay provided high sensitivity for ssDNA, protein, and dsDNA determination with the limits of detection as low as 0.2, 0.08, and 0.3 nM and the linear dynamic ranges of 10-150, 5-175, and 1-250 nM, respectively. The analytical performance for these analytes compares favorably with those by previously reported methods, demonstrating the potential usefulness and versatility of this new AFS-based bioassay. Moreover, the bioassay retains advantages of simplicity, cost-effectiveness, and sensitivity compared to most of the conventional methods.

  5. Tandem Mass Spectrometry Has a Larger Analytical Range than Fluorescence Assays of Lysosomal Enzymes: Application to Newborn Screening and Diagnosis of Mucopolysaccharidoses Types II, IVA, and VI.

    Science.gov (United States)

    Kumar, Arun Babu; Masi, Sophia; Ghomashchi, Farideh; Chennamaneni, Naveen Kumar; Ito, Makoto; Scott, C Ronald; Turecek, Frantisek; Gelb, Michael H; Spacil, Zdenek

    2015-11-01

    There is interest in newborn screening and diagnosis of lysosomal storage diseases because of the development of treatment options that improve clinical outcome. Assays of lysosomal enzymes with high analytical range (ratio of assay response from the enzymatic reaction divided by the assay response due to nonenzymatic processes) are desirable because they are predicted to lead to a lower rate of false positives in population screening and to more accurate diagnoses. We designed new tandem mass spectrometry (MS/MS) assays that give the largest analytical ranges reported to date for the use of dried blood spots (DBS) for detection of mucopolysaccharidoses type II (MPS-II), MPS-IVA, and MPS-VI. For comparison, we carried out fluorometric assays of 6 lysosomal enzymes using 4-methylumbelliferyl (4MU)-substrate conjugates. The MS/MS assays for MPS-II, -IVA, and -VI displayed analytical ranges that are 1-2 orders of magnitude higher than those for the corresponding fluorometric assays. The relatively small analytical ranges of the 4MU assays are due to the intrinsic fluorescence of the 4MU substrates, which cause high background in the assay response. These highly reproducible MS/MS assays for MPS-II, -IVA, and -VI can support multiplex newborn screening of these lysosomal storage diseases. MS/MS assays of lysosomal enzymes outperform 4MU fluorometric assays in terms of analytical range. Ongoing pilot studies will allow us to gauge the impact of the increased analytical range on newborn screening performance. © 2015 American Association for Clinical Chemistry.

  6. Development and validation of a liquid chromatography-fluorescence-mass spectrometry method to measure glyphosate and aminomethylphosphonic acid in rat plasma.

    Science.gov (United States)

    Bernal, J; Bernal, J L; Martin, M T; Nozal, M J; Anadón, A; Martínez-Larrañaga, M R; Martínez, M A

    2010-12-01

    A simple and fast method has been developed and validated to measure glyphosate (GLYP) and aminomethylphosphonic acid (AMPA) in rat plasma based on reversed-phase high performance liquid chromatography (RP-HPLC) coupled to fluorescence (FLD) and electrospray ionization mass spectrometry (ESI-MS) detection. After protein precipitation with acetonitrile, GLYP and AMPA were derivatized with 9-fluorenylmethylchloroformate (FMOC-Cl) and then separated on a C(12) column (250mm×4.60mm i.d.) using a gradient of an ammonium formate (20mM, pH 8.5) and acetonitrile mobile phase. Selected ion monitoring (SIM) mode of the MS was used to obtain maximum sensitivity when quantifying GLYP and AMPA. The validation shows the method to be consistent and reliable, with an intra- and inter-day precision for GLYP and AMPA>9% for both detectors. For both compounds the accuracy ranged from 2.1% to 7.8% for the intra-day readings, and from 4.1% to 8.6% for the inter-day values. The efficacy of GLYP extraction ranged from 87% to 93% and it was between 76% and 88% for AMPA. Moreover, the limits of quantification (LOQ) for GLYP and AMPA were 5 and 10ng/mL, respectively with FLD, and 0.4 and 2ng/mL with ESI-MS. The method was successfully applied to simultaneously measure both compounds in rat plasma samples several days after oral administration of glyphosate.

  7. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    Energy Technology Data Exchange (ETDEWEB)

    Van Pevenage, J., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Verhaeven, E. [Department of Conservation and Restoration, University College Antwerp, Blindestraat 9, B-2000 Antwerp (Belgium); Vekemans, B. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Lauwers, D., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Herremans, D.; De Clercq, W. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium); Vincze, L. [Department of Analytical Chemistry, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Moens, L., E-mail: Raman@UGent.be [Department of Analytical Chemistry, Raman Spectroscopy Research Group, Ghent University, Krijgslaan 281, S12, B-9000 Ghent (Belgium); Vandenabeele, P. [Department of Archaeology, Ghent University, Sint-Pietersnieuwstraat 35, B-9000 Ghent (Belgium)

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661–1722), and the samples of group B produced under emperor Qianlong (1735–1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated. - Highlights: • Fully described methodology for the analysis of silicate glazes of Chinese porcelain samples • The combination of a semi-quantitative analysis of silicate glazes, multi-variate data and statistical analysis. • The use of Seger formula to understand better the composition of the glazes. • New insights into the glaze composition and structure of Chinese porcelain glazes of different time periods.

  8. Environmental screening of acidic compounds based on capillary zone electrophoresis/laser-induced fluorescence detection with identification by gas chromatography/mass spectrometry and gas chromatography/high-resolution mass spectrometry.

    Science.gov (United States)

    Brumley, W C; Grange, A H; Kelliher, V; Patterson, D B; Montcalm, A; Glassman, J; Farley, J W

    2000-01-01

    This paper describes the application of capillary zone electrophoresis/laser-induced fluorescence detection (CZE/LIF) to the discovery of acidic compounds in environmental matrixes or the screening of extracts for acidic components. Published studies indicate that coal-derived materials contain a significant fraction of acidic compounds relative to materials derived from petroleum and shales. Such compounds may be useful as marker compounds for site assessment and source apportionment issues, and their identification may be important in toxicological and other health issues. We used deep-UV light from the frequency-doubled Ar ion laser at 244 and 257 nm to study extracts of samples. The CZE/LIF technique possesses good sensitivity and therefore overcomes one of the limitations of CZE with UV detection. The present work depends on high pressure/temperature solvent extraction of polynuclear aromatic hydrocarbon (PNA)-contaminated soil, followed by separation using CZE. The anionic analytes were separated by using borate or phosphate buffer (pH 9.2-12.3) after a chemical class separation. Samples were also characterized by gas chromatography/mass spectrometry (GC/MS) using full scans at low resolution, and elemental compositions were determined unequivocally by GC/high-resolution MS (GC/HRMS) using mass peak profiling (MPP). The similarity of low-resolution electron ionization mass spectra for a standard, 1-hydroxypyrene, and for a series of compounds in a contaminated-soil extract suggested that several types of phenolic and hydroxy-PNAs were present, including hydroxylated derivatives of fluorenes, fluoranthenes, and pyrenes. GC/HRMS using MPP confirmed the elemental compositions of the hydroxyfluorenes and hydroxypyrenes (and presumably hydroxyfluoranthenes) as [C13H10O] and [C16H10O], respectively. A new version of the MPP software was written for the Finnigan-MAT 900S-Trap and was similar to that developed previously for the VG 250SE. Inclusion of a calibration

  9. Determination of hydrogen sulfide and volatile thiols in air samples by mercury probe derivatization coupled with liquid chromatography-atomic fluorescence spectrometry.

    Science.gov (United States)

    Bramanti, Emilia; D'Ulivo, Lucia; Lomonte, Cristina; Onor, Massimo; Zamboni, Roberto; Raspi, Giorgio; D'Ulivo, Alessandro

    2006-10-02

    A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C6H4-COO- (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (-20 degrees C). The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 microg L(-1) for H2S, 13.7 microg L(-1) for CH(3)SH, 17.7 microg L(-1) for C2H5SH and 21.7 microg L(-1) for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 microg L(-1). Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071+/-0.154 microg min(-1) of H2S, giving a recovery of 99.8+/-7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil).

  10. Arsenic fractionation in agricultural soil using an automated three-step sequential extraction method coupled to hydride generation-atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rosas-Castor, J.M. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Portugal, L.; Ferrer, L. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Guzmán-Mar, J.L.; Hernández-Ramírez, A. [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico); Cerdà, V. [Group of Analytical Chemistry, Automation and Environment, University of Balearic Islands, Cra. Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Hinojosa-Reyes, L., E-mail: laura.hinojosary@uanl.edu.mx [Universidad Autónoma de Nuevo León, UANL, Facultad de Ciencias Químicas, Cd. Universitaria, San Nicolás de los Garza, Nuevo León, C.P. 66451 Nuevo León (Mexico)

    2015-05-18

    Highlights: • A fully automated flow-based modified-BCR extraction method was developed to evaluate the extractable As of soil. • The MSFIA–HG-AFS system included an UV photo-oxidation step for organic species degradation. • The accuracy and precision of the proposed method were found satisfactory. • The time analysis can be reduced up to eight times by using the proposed flow-based BCR method. • The labile As (F1 + F2) was <50% of total As in soil samples from As-contaminated-mining zones. - Abstract: A fully automated modified three-step BCR flow-through sequential extraction method was developed for the fractionation of the arsenic (As) content from agricultural soil based on a multi-syringe flow injection analysis (MSFIA) system coupled to hydride generation-atomic fluorescence spectrometry (HG-AFS). Critical parameters that affect the performance of the automated system were optimized by exploiting a multivariate approach using a Doehlert design. The validation of the flow-based modified-BCR method was carried out by comparison with the conventional BCR method. Thus, the total As content was determined in the following three fractions: fraction 1 (F1), the acid-soluble or interchangeable fraction; fraction 2 (F2), the reducible fraction; and fraction 3 (F3), the oxidizable fraction. The limits of detection (LOD) were 4.0, 3.4, and 23.6 μg L{sup −1} for F1, F2, and F3, respectively. A wide working concentration range was obtained for the analysis of each fraction, i.e., 0.013–0.800, 0.011–0.900 and 0.079–1.400 mg L{sup −1} for F1, F2, and F3, respectively. The precision of the automated MSFIA–HG-AFS system, expressed as the relative standard deviation (RSD), was evaluated for a 200 μg L{sup −1} As standard solution, and RSD values between 5 and 8% were achieved for the three BCR fractions. The new modified three-step BCR flow-based sequential extraction method was satisfactorily applied for arsenic fractionation in real agricultural

  11. 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.

  12. Determination of hydrogen sulfide and volatile thiols in air samples by mercury probe derivatization coupled with liquid chromatography-atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Bramanti, Emilia [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy)]. E-mail: emilia@ipcf.cnr.it; D' Ulivo, Lucia [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy); Lomonte, Cristina [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy); Ambiente s.c.r.l., Via Frassina 21, 54033, Carrrara, Massa (Italy); Onor, Massimo [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy); Zamboni, Roberto [Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa (Italy); Raspi, Giorgio [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy); D' Ulivo, Alessandro [Italian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa (Italy)

    2006-10-02

    A new procedure is proposed for the sampling and storage of hydrogen sulphide (H{sub 2}S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO-Hg-C{sub 6}H{sub 4}-COO{sup -} (PHMB), where they are derivatized to stable PHMB complexes based on mercury-sulfur covalent bonds. PHMB complexes are separated on a C{sub 18} reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV-vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB){sub 2}CH{sub 3}S-PHMB, C{sub 2}H{sub 5}S-PHMB and C{sub 3}H{sub 7}S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (-20 deg. C). The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 {mu}g L{sup -1} for H{sub 2}S, 13.7 {mu}g L{sup -1} for CH{sub 3}SH, 17.7 {mu}g L{sup -1} for C{sub 2}H{sub 5}SH and 21.7 {mu}g L{sup -1} for C{sub 3}H{sub 7}SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 {mu}g L{sup -1}. Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC-DAD-CVGAFS analysis has been validated, as example, for H{sub 2}S determination by a certified gas permeation tube as a source of 3.071 {+-} 0.154 {mu}g min{sup -1} of H{sub 2}S, giving a recovery of 99.8 {+-} 7% and it has been applied to the determination of

  13. Determination of Fe(II) and Fe(III) in small samples by microbore ion chromatography and photometric, atomic absorption spectrometry and total-reflection X-ray fluorescence detection

    Science.gov (United States)

    Sinner, T.; Hoffmann, P.; Ortner, H. M.

    1993-02-01

    Iron(II) and iron(III) are determined after separation on an ion Chromatographie column by various detection systems. "On-line" detection was achieved by the use of a photometer with a flow cell of 0.8 μl; for "off-line" detection, graphite furnace atomic absorption spectrometry or total-reflection X-ray fluorescence were used. The applicability of the methods is shown for standard solutions and atmospheric samples. As a typical result, 50 μg/l of iron can be determined in a 10 μl sample with a nucrobore ion chromatograph-photometer and atomic absorption system and 40 μg/l of iron in a microbore ion chromatograph-total-reflection X-ray fluorescence combination.

  14. Dual-sensitive probe 1-imidazole-2-(5-benzoacridine)-ethanone for the determination of amines in environmental water using HPLC with fluorescence detection and online atmospheric chemical ionization-mass spectrometry identification.

    Science.gov (United States)

    You, Jinmao; Song, Cuihua; Fu, Yanyan; Sun, Zhiwei; Xia, Lian; Li, Yulin; Suo, Yourui

    2010-01-15

    Dual-sensitive probe of 1-imidazole-2-(5-benzoacridine)-ethanone (IBAE) for the determination of free amines with fluorescence detection and online highly sensitive atmospheric chemical ionization-mass spectrometry identification (APCI-MS) has been developed. 2-(Benzoacridine)-5-acetic acid (BAAA) reacts with coupling agent N,N'-carbonyldiimidazole (CDI) to form a highly activated amide intermediate 1-imidazole-2-(5-benzoacridine)-ethanone (IBAE), which is dual-sensitive probe. The amide intermediate (IBAE) reacts preferably with amines in dimethylformamide (DMF) solvent to give the high yields of derivatives. IBAE-amine derivatives are not only sensitive to fluorescence but also to MS ionizable efficiency. The percent ionization delta values change from 0 to 57.32% in aqueous acetonitrile and from 0 to 62.14% in aqueous methanol. The relative standard deviations of the peak areas with fluorescence detection for each amine are fluorescence detection limits (at a signal-to-noise ratio of 3) are in the range of 0.15-0.50ng/ml. The online APCI-MS detection limits are in the range of 2.07-8.51ng/ml (at a signal-to-noise ratio of 3). Therefore, the facile IBAE intermediate derivatization allowed the development of a highly sensitive and specific method for the quantitative analysis of trace levels of amines in environmental water.

  15. Chemical profile of meta-chlorophenylpiperazine (m-CPP) in ecstasy tablets by easy ambient sonic-spray ionization, X-ray fluorescence, ion mobility mass spectrometry and NMR.

    Science.gov (United States)

    Romão, Wanderson; Lalli, Priscila M; Franco, Marcos F; Sanvido, Gustavo; Schwab, Nicolas V; Lanaro, Rafael; Costa, José Luiz; Sabino, Bruno D; Bueno, Maria Izabel M S; de Sa, Gilberto F; Daroda, Romeu J; de Souza, Vanderlea; Eberlin, Marcos N

    2011-07-01

    Meta-chlorophenylpiperazine (m-CPP) is a new illicit drug that has been sold as ecstasy tablets. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and X-ray fluorescence spectrometry (XRF) are shown to provide relatively simple and selective screening tools to distinguish m-CPP tablets from tablets containing amphetamines (mainly 3,4-methylenedioxymethamphetamine (MDMA)). EASI-MS detects the active ingredients in their protonated forms: [m-CPP + H](+) of m/z 197, [MDMA + H](+) of m/z 194, and [2MDMA + HCl + H](+) of m/z 423 and other ions from excipients directly on the tablet surface, providing distinct chemical fingerprints. XRF identifies Cl, K, Ca, Fe, and Cu as inorganic ingredients present in the m-CPP tablets. In contrast, higher Cl concentrations and a more diverse set of elements (P, Cl, Ca, Fe, Cu, Zn, Pt, V, Hf, Ti, Pt, and Zr) were found in MDMA tablets. Principal component analysis applied to XRF data arranged samples in three groups: m-CPP tablets (four samples), MDMA tablets (twenty three samples), and tablets with no active ingredients (three samples). The EASI-MS and XRF techniques were also evaluated to quantify m-CPP in ecstasy tablets, with concentrations ranging from 4 to 40 mg of m-CPP per tablets. The m-CPP could only be differentiated from its isomers (o-CPP and for the three isomers p-CPP) by traveling wave ion mobility mass spectrometry and NMR measurements.

  16. Dispersive liquid-liquid microextraction using diethyldithiocarbamate as a chelating agent and the dried-spot technique for the determination of Fe, Co, Ni, Cu, Zn, Se and Pb by energy-dispersive X-ray fluorescence spectrometry

    Science.gov (United States)

    Kocot, Karina; Zawisza, Beata; Sitko, Rafal

    2012-07-01

    Dispersive liquid-liquid microextraction (DLLME) using sodium diethyldithiocarbamate (DDTC) as a chelating agent was investigated for the simultaneous determination of iron, cobalt, nickel, copper, zinc, selenium and lead ions in water samples. The procedure was performed using 5 mL of the sample, 100 μL of a 0.5% solution of DDTC, 30 μL of carbon tetrachloride (extraction phase) and 500 μL of methanol (disperser solvent). The experiments showed that Fe, Co, Ni, Cu, Zn and Pb can be simultaneously extracted at a pH of 5 and that Se can be extracted at a pH of 2-3. The results were compared with those obtained using ammonium pyrrolidine dithiocarbamate as a chelating agent. For all analytes, a linear range was observed up to 0.4 μg mL- 1. If Fe and Zn are present in concentrations 10 times higher than those of the other analytes, then the linearity is observed up to 0.2 μg mL- 1. In the present study, the organic phase that contained preconcentrated elements was deposited onto a Millipore filter and measured using energy-dispersive X-ray fluorescence spectrometry. The obtained detection limits were 2.9, 1.5, 2.0, 2.3, 2.5, 2.0 and 3.9 ng mL- 1 for Fe, Co, Ni, Cu, Zn, Se and Pb, respectively. This combination of DLLME and the dried-spot technique is promising for multielement analyses using other spectroscopy techniques, such as laser ablation-inductively coupled plasma-mass spectrometry, laser-induced breakdown spectroscopy or total-reflection X-ray fluorescence spectrometry.

  17. Rhodamine 6G hydrazone bearing thiophene unit: A highly sensitive and selective off-on fluorescent chemosensor for Al3+

    Science.gov (United States)

    Wu, Wei-Na; Mao, Pan-Dong; Wang, Yuan; Zhao, Xiao-Lei; Jia, Lei; Xu, Zhou-Qing

    2016-10-01

    A rhodamine derivative (R1) has been synthesized by a hydrazone formation of rhodamine 6G hydrazide with 3-methylthiophene-2-carbaldehyde, which exhibits high selectivity and sensitivity as an "off-on" fluorescent sensor toward Al3+ in water containing media. The binding process was confirmed by UV-vis absorption, fluorescence measurements, mass spectroscopy and DFT calculation. The probe functions by Al3+ induced hydrolytic cleavage of the imine-bond to produce an intense rhodamine-based emission. To test the practical use of the probe, the determination of Al3+ in real water samples was also evaluated.

  18. Resolution and identification of major peanut allergens using a combination of fluorescence two-dimensional differential gel electrophoresis, western blotting and Q-TOF mass spectrometry.

    Science.gov (United States)

    Peanut allergy is triggered by several proteins known as allergens. The matching resolution and identification of major peanut allergens in 2D protein maps, was accomplished by the use of fluorescence two-dimensional differential gel electrophoresis (2D DIGE), Western blotting and quadrupole time-of...

  19. 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

  20. Molecular recognition: Comparative study of a tunable host-guest system by using a fluorescent model system and collision-induced dissociation mass spectrometry on dendrimers

    DEFF Research Database (Denmark)

    Pittelkow, M.; Nielsen, C.B.; Broeren, A.C.

    2005-01-01

    work we have quantified the binding constants for the host-guest interactions between two different host motifs and six different guest molecules. The host molecules, which resemble the periphery of a poly(propylene imine) dendrimer, have been fitted with an anthracene-based fluorescent probe. The two...

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

    NARCIS (Netherlands)

    Willigen, van 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 constit

  2. High performance liquid chromatography coupled to atomic fluorescence spectrometry for the speciation of the hydride and chemical vapour-forming elements As, Se, Sb and Hg: A critical review

    Energy Technology Data Exchange (ETDEWEB)

    Chen Yuwei [Department of Chemistry and Biochemistry, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada); Belzile, Nelson, E-mail: nbelzile@laurentian.ca [Department of Chemistry and Biochemistry, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada); Cooperative Freshwater Ecology Unit, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6 (Canada)

    2010-06-25

    We present the most recent applications of high performance liquid chromatography (HPLC) hyphenated to hydride generation or chemical vapour generation and atomic fluorescence spectrometry (HG/CVG-AFS), for the determination and speciation of the selected hydride-forming elements arsenic (As), selenium (Se) and antimony (Sb) and the chemical vapour-forming metal Hg. The review focuses on sample preparation, post-column treatments and on the applications of this technique to various liquid and solid samples. This review also intends to discuss some limitations associated to HPLC-HG/CVG-AFS due to the necessity on post-column treatments, including the oxidation of organo-element compounds and the pre-reduction to a suitable valence. Nevertheless, the hyphenated technique HPLC-HG/CVG-AFS remains an efficient, sensitive and affordable approach to perform speciation of the four studied elements as shown by the variety of applications presented and discussed in this review.

  3. Determination of rubidium and strontium in geological materials by X-Ray fluorescence spectrometry; Determinacion de rubidio y estroncio en materiales geologicos mediante espectrometria de fluorescencia de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Roca, M.

    1979-07-01

    In order to determine whole-rock ages by the Rb/Sr procedure, an X-ray fluorescence spectrometry method for the determination of both elements has been developed. The samples are pressed into boric acid backed and ringed pellets with this material as a binding agent. Matrix corrections are made following the determination od the mass absorption coefficients, based on the intensity of the Compton-scattered peak of MoK{alpha}. or MoK{beta}{sub 1}.3. The U. S. Geological Survey granodiorite GSP-1 is used as a reference standard. Spectral-line interferences have been carefully studied and the empirical correction factors determined. A BASIC language program for calculating the Rb and Sr concentrations and the Rb/Sr ratios has been written. (Author) 7 refs.

  4. Application of dot matrix LCD in multi-element portable X-ray fluorescence spectrometry The LCD is stated for Liquid Crystal Display

    CERN Document Server

    Lin Yan Chang; Lai Wan Chang; Zhou Si Chun

    2002-01-01

    Dot matrix LCD based on T6963C is a low power supply module. It needs no complex interface circuits connecting with MCU. Application in text and graphics is easy. Application of this LCD in multi-element portable XRF spectrometry is show. How to use it in Chinese, pull-down menu, spectrum and how to design the interface circuits with embedded computer are shown as well

  5. 应用荧光光谱法检测蓝藻生物量%Detecting Cyanobacterial Biomass by Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王金霞; 罗固源

    2011-01-01

    Anabaena flos-aquae were scanned in vivo by fluorescence spectrum.The estimated optimal excitation and emission wavelength of cyanobacterial phycocyanin fluorescence were 620nm,650nm respectively and a linear relationship between anabaena flos-aquae biomass and the phycocyanin characteristic fluorescence intensity was detected.The results impressed that applying fluorescence spectrum to detect the phycocyanin fluorescence intensity and reflect the anabaena flos-aquae biomass is specific and feasible.The method is characterized by its simplicity,high speed,simple operation and impretreatment.A fresh method is provided to detect cyanobacterial biomass in water.%本研究应用荧光分光光度计,通过对水华鱼腥藻活体荧光光谱的扫描,确定了蓝藻藻蓝蛋白荧光测定的最佳荧光激发波长为620nm,荧光发射波长为650nm,建立了水华鱼腥生物量与藻蓝蛋白特征荧光强度的线性检测关系,表明应用荧光光谱法检测藻蓝蛋白荧光强度反应蓝藻生物量具有特异性和可行性,该方法具有简便、快速、操作简单、样品无需处理等优点。为测定蓝藻生物量提供了新的检测方法。

  6. X-ray fluorescence spectrometry used to assess the dispersion of metals within mining environments; Aplicacion de la tecnica de espectrometria de fluorescencia de rayos-X en el estudio de la dispersion de metales en areas mineras

    Energy Technology Data Exchange (ETDEWEB)

    Margui, E.; Gonzalez-Fernandez, O.; Hidalgo, M.; Pardini, G.; Queralt, I.

    2011-07-01

    One critical factor for success in characterizing metals polluting mining environments so as to be able to eliminate them and subsequently recover these areas depends upon a speedy and correct response in the analysis of samples. Rapid, simultaneous, multi-element analysis can be undertaken using X-ray fluorescence spectrometry, a versatile, non-destructive analytical technique commonly employed to identify both major and minor elements in samples related to environmental studies. An additional advantage of this technique is the possibility of conducting the analysis directly on solid samples, which is extremely convenient when dealing with environmental samples that are difficult to dissolve, such as soils, sediments and mining wastes. Moreover, in recent years the development of spectrometers equipped with digital-signal processors combined with enlarged X-ray production, using better designs for excitation-detection, has contributed to an improvement in instrumental sensitivity, thus allowing us to detect important polluting elements such as Cd and Pb at trace levels. In this paper the authors describe, on the basis of their own experience, some interesting applications of XRF spectrometry for the analysis of several types of environmental samples related to the study of the dispersion of metals within mining environments: (A) analysis of mining wastes, soils and sediments; (B) analysis of samples of vegetation used as bio indicators or related to phyto remediation studies; and (C) analysis of water samples related to mining operations. (Author) 26 refs.

  7. Application Of Some Chemometric Methods To Energy Dispersive X-ray Fluorescence Spectrometry [aplicação De Alguns Modelos Quimiométricos à Espectroscopia De Fluorescência De Raios-x De Energia Dispersiva

    OpenAIRE

    Schimidt F.; Bueno M.I.M.S.; Poppi R.J.

    2002-01-01

    The objective of this work was to accomplish the simultaneous determination of some chemical elements by Energy Dispersive X-ray Fluorescence (EDXRF) Spectroscopy through multivariate calibration in several sample types. The multivariate calibration models were: Back Propagation neural network, Levemberg-Marquardt neural network and Radial Basis Function neural network, fuzzy modeling and Partial Least Squares Regression. The samples were soil standards, plant standards, and mixtures of lead ...

  8. Determination of elements in some lichens growing in Giresun and Ordu province (Turkey) using energy dispersive X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Aslan, A. [Department of Biology, Education Faculty, Atatuerk University, 25240 Erzurum (Turkey); Budak, G. [Department of Physics, Science and Art Faculty, Atatuerk University, 25240 Erzurum (Turkey)]. E-mail: gbudak@atauni.edu.tr; Tirasoglu, E. [Department of Physics, Faculty of Arts and Sciences, Karadeniz Technical University, Trabzon (Turkey); Karabulut, A. [Department of Physics, Science and Art Faculty, Atatuerk University, 25240 Erzurum (Turkey)

    2006-01-15

    The concentration of five different elements in six lichens species of different regions in Giresun and Ordu (Turkey) was determined using the energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied to the elemental analysis of lichens. An annular 50 mCi {sup 241}Am radioactive source and an annular 50 mCi {sup 55}Fe radioactive source were used for excitation of characteristic K X-rays. An Si(Li)detector which has a 147 eV full-width at half-maximum for 5.9 keV photons was used for intensity measurements. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, iron, and barium.

  9. Supercritical fluid extraction for some carbamate insecticides in potatoes samples, with HPLC/fluorescence determination and HPLC/mass spectrometry confirmation

    OpenAIRE

    Gilvanda Silva Nunes; Teresa Cristina R. Santos; Damiá Barceló; Alexandre Santos Pimenta; Maria Lúcia Ribeiro

    2002-01-01

    Six supercritical fluid extraction (SFE) methods were tested, by varying the following operational parameters: CO2 pressure, time and temperature of extraction, type and proportion of static modifier, and Hydromatrix®/sample rate into cell. Firstly, insecticide carbamates were extracted from spiked potatoes samples (fortification level of 0,5 mg.Kg-1) by using SPE procedures, and then final extracts were analyzed HPLC/fluorescence. Good performance was observed with SFE methods that operated ...

  10. [Determining the level of histamine in canned fish by the fluorometric method using the Spekol-10 apparatus with FK device for fluorescence spectrometry].

    Science.gov (United States)

    Fonberg-Broczek, M; Sawilska-Rautenstrauch, D; Windyga, B

    1991-01-01

    The content of histamine in canned fish products was determined by fluorometric method recommended by AOAC with final determination of fluorescence on spectrophotometer Spekol 10 with FKC equipment of wave excitation for maximum of emission: lambda = 365 nm, filter GVK--48). The method makes possible quick, reproducible, and sensitive determination (limit of detection: 1 mg/100 g of product) of histamine in canned fish products, on simple equipment available in every laboratory of count Sanitary Stations.

  11. Elemental ratios for characterization of quantum-dots populations in complex mixtures by asymmetrical flow field-flow fractionation on-line coupled to fluorescence and inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Menendez-Miranda, Mario; Fernandez-Arguelles, Maria T.; Costa-Fernandez, Jose M., E-mail: jcostafe@uniovi.es; Encinar, Jorge Ruiz; Sanz-Medel, Alfredo, E-mail: asm@uniovi.es

    2014-08-11

    Highlights: • The hyphenated system allows unequivocal identification of nanoparticle populations. • AF4 separation permitted detection of unexpected nanosized species in a sample. • ICP-QQQ provides elemental ratios with adequate accuracy in every nanoparticle. • Purity and chemical composition of different quantum dot samples were assessed. - Abstract: Separation and identification of nanoparticles of different composition, with similar particle diameter, coexisting in heterogeneous suspensions of polymer-coated CdSe/ZnS quantum dots (QDs) have been thoroughly assessed by asymmetric flow field-flow fractionation (AF4) coupled on-line to fluorescence and inductively coupled plasma mass spectrometry (ICPMS) detectors. Chemical characterization of any previously on-line separated nanosized species was achieved by the measurement of the elemental molar ratios of every element involved in the synthesis of the QDs, using inorganic standards and external calibration by flow injection analysis (FIA). Such elemental molar ratios, strongly limited so far to pure single nanoparticles suspensions, have been achieved with adequate accuracy by coupling for the first time an ICP-QQQ instrument to an AF4 system. This hyphenation turned out to be instrumental to assess the chemical composition of the different populations of nanoparticles coexisting in the relatively complex mixtures, due to its capabilities to detect the hardly detectable elements involved in the synthesis. Interestingly such information, complementary to that obtained by fluorescence, was very valuable to detect and identify unexpected nanosized species, present at significant level, produced during QDs synthesis and hardly detectable by standard approaches.

  12. 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

    Science.gov (United States)

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

    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 Hg2 + 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 TiO2 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.

  13. Continuous Determination of Heavy Metals in Water by Atomic Fluorescence and Atomic Absorption Spectrometry%原子荧光和原子吸收法连续测定水中的重金属

    Institute of Scientific and Technical Information of China (English)

    谢倩

    2015-01-01

    通过剖析原子荧光和原子吸收法的不同消解体系,优化实验条件,确定了原子荧光和原子吸收法连续测定水中的硒、砷、锌、铜的含量的最佳消解条件和最佳仪器测定条件。经加标回收以及标样分析,连续测定的灵敏度高,回收率在95.9%~109%之间,相对标准误差低于4.41%,操作简便快速,结果精确。%By analyzing the different digestion system of atomic fluorescence and atomic absorption method and optimizing experimental conditions, the optimal digestion conditions and the best measurement conditions of instruments for continuous determination selenium, arsenic, zinc, copper content in water by atomic fluorescence and atomic absorption spectrometry were determined.Spiking recovery and standard analysis result showed that continuous measurement had high sensitivity, and the recoveries was between 95.9% and 109%, relative standard deviation was less than 4.41%, the operation was simple, rapid and accurate.

  14. Determination of nitrofuran metabolites in shrimp by high performance liquid chromatography with fluorescence detection and liquid chromatography-tandem mass spectrometry using a new derivatization reagent.

    Science.gov (United States)

    Du, Na-Na; Chen, Ming-Ming; Sheng, Liang-Quan; Chen, Shui-Sheng; Xu, Hua-Jie; Liu, Zhao-Di; Song, Chong-Fu; Qiao, Rui

    2014-01-31

    A high performance liquid chromatography with fluorescence detection (HPLC-FLD) method for the simultaneous determination of total nitrofuran metabolite residues (furazolidone, furaltadone, nitrofurantoin, and nitrofurazone) in shrimp was developed. The method involves the acid hydrolysis of protein-bound metabolites, followed by the derivatization of the freed metabolites with the new fluorescent derivatization reagent 2-hydroxy-1-naphthaldehyde (HN) and subsequent liquid-liquid extraction (LLE). Separation is achieved on a YMC-Pack Polymer C18 column under alkaline conditions, and the high fluorescence intensity of the derivatives at an emission wavelength Em=463nm (Ex=395nm) enables, for the first time, their simultaneous determination in shrimp at concentrations as low as 1μg/kg by HPLC-FLD. The method was validated using blank shrimp fortified with all four metabolites at 0.5, 1.0 and 2.0μg/kg. Recoveries were >87% with relative standard deviations of HPLC-FLD were in very good agreement with those obtained by LC-MS/MS analysis.

  15. Dispersive liquid-liquid microextraction using diethyldithiocarbamate as a chelating agent and the dried-spot technique for the determination of Fe, Co, Ni, Cu, Zn, Se and Pb by energy-dispersive X-ray fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kocot, Karina; Zawisza, Beata; Sitko, Rafal, E-mail: rafal.sitko@us.edu.pl

    2012-07-15

    Dispersive liquid-liquid microextraction (DLLME) using sodium diethyldithiocarbamate (DDTC) as a chelating agent was investigated for the simultaneous determination of iron, cobalt, nickel, copper, zinc, selenium and lead ions in water samples. The procedure was performed using 5 mL of the sample, 100 {mu}L of a 0.5% solution of DDTC, 30 {mu}L of carbon tetrachloride (extraction phase) and 500 {mu}L of methanol (disperser solvent). The experiments showed that Fe, Co, Ni, Cu, Zn and Pb can be simultaneously extracted at a pH of 5 and that Se can be extracted at a pH of 2-3. The results were compared with those obtained using ammonium pyrrolidine dithiocarbamate as a chelating agent. For all analytes, a linear range was observed up to 0.4 {mu}g mL{sup -1}. If Fe and Zn are present in concentrations 10 times higher than those of the other analytes, then the linearity is observed up to 0.2 {mu}g mL{sup -1}. In the present study, the organic phase that contained preconcentrated elements was deposited onto a Millipore filter and measured using energy-dispersive X-ray fluorescence spectrometry. The obtained detection limits were 2.9, 1.5, 2.0, 2.3, 2.5, 2.0 and 3.9 ng mL{sup -1} for Fe, Co, Ni, Cu, Zn, Se and Pb, respectively. This combination of DLLME and the dried-spot technique is promising for multielement analyses using other spectroscopy techniques, such as laser ablation-inductively coupled plasma-mass spectrometry, laser-induced breakdown spectroscopy or total-reflection X-ray fluorescence spectrometry. - Highlights: Black-Right-Pointing-Pointer Multielement trace analysis using dried-spot technique and dispersive liquid-liquid microextraction. Black-Right-Pointing-Pointer Possibility of combination of LPME with EDXRF, LIBS or LA-ICP-MS. Black-Right-Pointing-Pointer Comparison of APDC and DDTC as chelating agents.

  16. 离子色谱-氢化物发生原子荧光法测定尿中形态砷%Determination of arsenic species in urine by ion chromatography-hydride generation-atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    魏静; 梁琼; 刘俊娓

    2013-01-01

    Objective:To develop a method for the determination of arsenic species in urine by Ion chromatography - hydride Generation - atomic fluorescence spectrometry. Methods; The urine sample was filtered by 0.45 μm membrane. Using ( NH4 ) 2 HPO4 as mobile phase to explore the best ion chromatographic separation condition and the atomic fluorescence determination condition. The content of various forms of arsenic was determined by Ion chromatography - hydride Generation - atomic fluorescence spectrometry. Results; This method had good relativity and good precision(2.60% ~4. 30% ). The detection limits of As( Ⅲ), DMA, MMA and As( V ) were 2. 0 (μg/L, 4.0 μg/L,4.0 μg/L,8.0 μg/L, the average recoveries of samples were 90.48% ~ 102.90%. Conclusion; The method had the advantages of convenience, speediness, high sensitivity, less interference and high practical value without chemical pretreatment.%目的:建立离子色谱-氢化物发生原子荧光法测定尿中形态砷的方法.方法:尿样经0.45 μm滤膜过滤,以(NH4)2HPO4为流动相,采用离子色谱-氢化物发生原子荧光联机测定不同形态砷的含量.结果:实验结果相关性好,线性范围宽,精密度RSD为2.60%~4.30%,方法检出限为As(Ⅲ)2.0 μg/L,DMA4.0 μg/L,MMA4.0 μg/L,As(V)8.0 μg/L,该方法所得回收率为90.48% ~ 102.90%.结论:方法简便、快速、无需化学预处理、干扰少、灵敏度高,有较高的实用价值.

  17. Performance of the wet oxidation unit of the HPLC isotope ratio mass spectrometry system for halogenated compounds.

    Science.gov (United States)

    Gilevska, Tetyana; Gehre, Matthias; Richnow, Hans Hermann

    2014-08-05

    The performance of liquid chromatography-isotope ratio mass spectrometry (LC-IRMS) for polar halogenated compounds was evaluated. Oxidation capacity of the system was tested with halogenated acetic acids and halogenated aromatic compounds. Acetic acid (AA) was selected as a reference compound for complete oxidation and compared on the molar basis to the oxidation of other analytes. The isotope values were proofed with calibrated δ(13)C values obtained with an elemental analyzer (EA). Correct isotope values were obtained for mono- and dichlorinated, fluorinated, and tribrominated acetic acids and also for aniline, phenol, benzene, bromobenzene, chlorobenzene, 1,2-dichlorobenzene, 2,4,6-trichlorophenol, pentafluorophenol, and nitrobenzene. Incomplete oxidation of trichloroacetic acid (TCA) and trifluoroacetic acid (TFA) resulted in lower recovery compared to AA (37% and 24%, respectively) and in isotopic shift compared to values obtained with EA (TCA Δδ(13)C(EA/LC-IRMS) = 8.8‰, TFA Δδ(13)C(EA/LC-IRMS) = 6.0‰). Improvement of oxidation by longer reaction time in the reactor and increase in the concentration of sulfate radicals did not lead to complete combustion of TCA and TFA needed for δ(13)C analysis. To the best of our knowledge, this is the first time such highly chlorinated compounds were studied with the LC-IRMS system. This work provides information for method development of LC-IRMS methods for halogenated contaminants that are known as potential threats to public health and the environment.

  18. Energy-dispersive x-ray fluorescence spectroscopy and inductively coupled plasma emission spectrometry evaluated for multielement analysis in complex biological matrices.

    Science.gov (United States)

    Irons, R D; Schenk, E A; Giauque, R D

    1976-12-01

    Energy-dispersive x-ray spectroscopy and inductively coupled plasma emission spectrometry were evaluated as methods for routine multielement analysis of biological material. Standard samples included Standard Reference Materials (National Bureau of Standards), compounded mixtures, and supplements that provided a wide range of elemental concentrations for analysis. Elements included in this study were Zn, Pb, Ni, Mn, Fe, Mg, Cu, Ca, As, Se, Br, Rb, and Sr. Standards were analyzed as unknowns by participating laboratories. The two methods were evaluated for sensitivity, precision, and accuracy, and the results compared to those obtained for atomic absorption spectrometric analysis of identical standard unknowns. Both methods compared favorably and both were determined to be highly reliable for such an application. Advantages and disadvantages of each method are compared and discussed.

  19. Oligosaccharide mapping of heparinase I-treated heparins by hydrophilic interaction liquid chromatography separation and online fluorescence detection and electrospray ionization-mass spectrometry characterization.

    Science.gov (United States)

    Galeotti, Fabio; Volpi, Nicola

    2016-05-06

    Oligosaccharide mapping based on enzyme cleavage provides a useful molecular fingerprint of the heparin structure revealing detailed structural information regarding its sequence and the content of part of the ATIII-binding region. This approach is performed by strong-anion exchange (SAX)-HPLC separation which is incompatible with MS requiring purification of oligosaccharides for their conclusive identification. We report a novel oligosaccharide mapping strategy based on the HILIC separation of the main heparin disaccharides/oligosaccharides released by heparinase I, fluorotagged with 2-aminoacridone and on-line detected by a fluorescence detector and characterized by ESI-MS. The application of a polar solvent having a high pH with acetonitrile avoided desulfation enabling a simple and accurate structural oligosaccharide assignment. Oligosaccharide mapping, or merely complete disaccharide composition, may be performed on nanogram-scale by the fluorescence detector vs micrograms useful for classical SAX-HPLC. Additionally, only widely commercially available heparin lyase I is necessary, without the use of expensive heparinases II and III. Contrary to SAX-HPLC, this novel HILIC approach is able to separate and identify the saturated trisulfated disaccharide belonging to the non-reducing end of heparin chains. Finally, the content of 3-O-sulfo groups of the ATIII-binding region is determined.

  20. Caracterização dos níveis de elementos químicos em solo, submetido a diferentes sistemas de uso e manejo, utilizando espectrometria de fluorescência de raios-x por energia dispersiva (EDXRF Characterization of chemical elements in soil submitted to different systems use and management by energy dispersive x-ray fluorescence spectrometry (EDXRF

    Directory of Open Access Journals (Sweden)

    Arci Dirceu Wastowski

    2010-01-01

    Full Text Available This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agro forestry (SAF, T2 - Native Field (CN, T3 - Native Forest (NM, T4 - Tillage Forest (PF; T5 - conventional tillage system (SPC and T6 - System tillage (NT. Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm.

  1. Fast method for multielemental analysis of plants and discrimination according to the anatomical part by total reflection X-ray fluorescence spectrometry.

    Science.gov (United States)

    De la Calle, Inmaculada; Costas, Marta; Cabaleiro, Noelia; Lavilla, Isela; Bendicho, Carlos

    2013-05-01

    Fast and reliable analytical methodologies are required for quality control of plants in order to assure human health. Ultrasound-assisted extraction in combination with total reflection X-ray fluorescence is proposed as a fast and simple method for multielemental analysis of plants on a routine basis. For this purpose, five certified reference materials have been analysed for the determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn and Pb. Different extractant media (acids and oxidants) were tried. A mixture of diluted HNO(3)+HCl+HF, was selected as the best option for the achievement of complete extractions. Accurate and precise results can be reached in most cases along with a high sample throughput. Different plants (i.e., herbs, spices and medicinal plants) were analysed. Linear discriminant analysis together with the elemental concentrations allowed the differentiation of commercial preparations corresponding to flower, fruit and leaf.

  2. 不锈钢的 X射线荧光光谱分析%Analysis of Stainless Steel by X _ Ray Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    郝贡章; 卜赛斌; 高新华; 谢荣厚

    2001-01-01

    Contents of Al,Si,P,S,Ti,Cr,Mn,Co,Ni,Cu,As,Mo,W,Fe in stainless steel were determined by high performance philips PW 2400 X _ ray fluorescence spectrometer.Correction factors of interference elements and correction factors for matrix effects were given.The method is senstive,rapid,accurate and repeatable.%用高性能飞利浦PW2400 X射线荧光光谱仪,测定不锈钢中 Al、 Si、 P、 S、 Ti、 Cr、 Mn、 Co、 Ni、 Cu、 As、 Mo、 Sn、 W、 Fe 15个元素。给出了各元素的干扰校正系数和基体效应校正系数。方法准确、灵敏、稳定性好、速度快。

  3. Determination of methyl mercury in fish by toluene extraction and atomic fluorescence spectrometry%甲苯萃取-原子荧光光谱法检测鱼肉中甲基汞

    Institute of Scientific and Technical Information of China (English)

    史永富; 田良良; 黄冬梅; 蔡友琼; 黄宣运; 于慧娟

    2014-01-01

    Objective To establish a method for the determination of methyl mercury in fish by toluene extraction and atomic fluorescence spectrometry (AFS). Methods Samples were digested by HBr(48%, v/v) for 30 min, and methyl mercury was extracted by methylbenzene. The extract was back-extracted into aqueous solution by Na2S2O3. The aqueous solution was ready for the analysis by atomic fluorescence spectrometry (AFS). And the present method was used to determine the concentration of methyl mercury in reference materials. Results The result was in accordance with the assigned value. Recoveries were 96.1%and 97.5% respectively. Conclusion The method is effective to determine methyl mercury in fish for its high sensitivity and reproducibility.%目的:建立甲苯萃取-原子荧光光谱检测鱼肉中甲基汞的方法。方法样品经48%氢溴酸水解、甲苯萃取、0.05 mol/L硫代硫酸钠反萃取后,应用AFS-9230原子荧光光谱法进行测定,同时经此前处理后的样品采用DMA-80直接测汞仪进行测定,与原子荧光光谱法的结果进行对比。结果原子荧光光谱法以及直接测汞仪直接测定的结果与标准物质定值吻合,确证该方法的可靠性,适用于鱼、贝等水产品中甲基汞的测定。采用该方法对鱼肉中总汞与甲基汞成分分析标准物质 GBW10029以及英国食品分析水平评估计划(food analysis performance assessment scheme, FAPAS)的罐装鱼肉样品(样品编号07189)进行了检测,检测结果与参考物定值吻合,回收率分别为96.1%,97.5%。结论该方法操作简单,灵敏度高,重现性好,适用于鱼肉中甲基汞含量的定量检测。

  4. Quantification and micron-scale imaging of spatial distribution of trace beryllium in shrapnel fragments and metallurgic samples with correlative fluorescence detection method and secondary ion mass spectrometry (SIMS).

    Science.gov (United States)

    Abraham, J L; Chandra, S; Agrawal, A

    2014-11-01

    Recently, a report raised the possibility of shrapnel-induced chronic beryllium disease from long-term exposure to the surface of retained aluminum shrapnel fragments in the body. Since the shrapnel fragments contained trace beryllium, methodological developments were needed for beryllium quantification and to study its spatial distribution in relation to other matrix elements, such as aluminum and iron, in metallurgic samples. In this work, we developed methodology for quantification of trace beryllium in samples of shrapnel fragments and other metallurgic sample-types with main matrix of aluminum (aluminum cans from soda, beer, carbonated water and aluminum foil). Sample preparation procedures were developed for dissolving beryllium for its quantification with the fluorescence detection method for homogenized measurements. The spatial distribution of trace beryllium on the sample surface and in 3D was imaged with a dynamic secondary ion mass spectrometry instrument, CAMECA IMS 3f secondary ion mass spectrometry ion microscope. The beryllium content of shrapnel (∼100 ppb) was the same as the trace quantities of beryllium found in aluminum cans. The beryllium content of aluminum foil (∼25 ppb) was significantly lower than cans. SIMS imaging analysis revealed beryllium to be distributed in the form of low micron-sized particles and clusters distributed randomly in X-Y- and Z dimensions, and often in association with iron, in the main aluminum matrix of cans. These observations indicate a plausible formation of Be-Fe or Al-Be alloy in the matrix of cans. Further observations were made on fluids (carbonated water) for understanding if trace beryllium in cans leached out and contaminated the food product. A direct comparison of carbonated water in aluminum cans and plastic bottles revealed that beryllium was below the detection limits of the fluorescence detection method (∼0.01 ppb). These observations indicate that beryllium present in aluminum matrix was either

  5. Rapid and sensitive determination of benzo[a]pyrene in black ginseng using fluorescence detector and high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    Cho, Hyun-jeong; Kim, Hye-jin; Son, Byeong-cheol; Jo, Dong-keun; Cho, Byung-lim

    2013-05-01

    Black ginseng is produced by steaming a ginseng root followed by drying repeatedly 9 times during the process and it is changed to be black color, so it is known that a black ginseng has more contents of saponins than red ginseng. However a fake black ginseng which is produced to be black color at high temperature in a short period of time generate carcinogenic benzo[a]pyrene(BaP) through the process. In this year, maximum residue level(MRL) for BaP was established to 2 ug/kg in black ginseng and more sensitive method was developed to quantitatively analyze the BaP by high performance liquid chromatography (HPLC) coupling with florescence detector and tandem mass spectrometry (atmospheric pressure chemical ionization-MS/MS). Chromatographic separation was performed on a Supelcosil™ LC-PAH column (3 μm, 3 mm x 50 mm). Mobile phase A was water and mobile phase B was acetonitrile. BaP was exactly separated from other 15 polycyclic aromatic hydrocarbons (PAHs) which have been selected as priority pollutants by the US Environmental Protection Agency (EPA). Linearity of detection was in the range of 0.2~20 μg/kg and limit of detection (LOD) for BaP was lower than 0.1 μg/kg, limit of quantification (LOQ) was 0.2 μg/kg. The recovery of Bap was 92.54%+/-6.3% in black ginseng.

  6. Determination of Arsenic in Matricaria chamomilla L.by microwave digestion-atomic fluorescence spectrometry%微波消解-原子荧光光谱法测定洋甘菊中砷的含量

    Institute of Scientific and Technical Information of China (English)

    辛禄德; 李强; 王建玲; 劳斐; 田树革

    2014-01-01

    Objective To develop an atomic fluorescence spectrometric method for the determination of Ar-senic in Matricaria chamomilla L.Methods Sample was digested with microwave digestion system.The Arsenic was directly analyzed by atomic fluorescence spectrometry,and the methodology of the study was investigated.Results The content of arsenic within the range of 0-10.0 μg/L the correlative coefficient of the calibration curves was over 0.999 3,the average recovery was 100.81% with RSD of 2.59% (n =6). Conclusion The method is convenient,stable,less harmful and highly sensitive.%目的:建立洋甘菊中砷含量的原子荧光光谱检测方法。方法采用微波消解样品,通过原子荧光光谱法测定洋甘菊中砷含量,并进行了方法学考察。结果砷在0~10.0μg/L (r =0.9993)范围内峰面积与浓度呈良好线性关系,平均加样回收率为100.81%,RSD=2.59%(n =6)。结论该测量方法简便、稳定、危害小、灵敏度高。

  7. Medieval glass from the Cathedral in Paderborn: a comparative study using X-ray absorption spectroscopy, X-ray fluorescence, and inductively coupled laser ablation mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hormes, J. [University of Saskatchewan, Canadian Light Source Inc., Saskatoon, SK (Canada); Louisiana State University, CAMD, Baton Rouge, LA (United States); Roy, A.; Bovenkamp, G.L. [Louisiana State University, CAMD, Baton Rouge, LA (United States); Simon, K. [University of Goettingen, Geochemistry, Centre for Geosciences, Goettingen (Germany); Kim, C.Y. [University of Saskatchewan, Canadian Light Source Inc., Saskatoon, SK (Canada); Boerste, N. [Faculty for Theology Paderborn, Paderborn (Germany); Gai, S. [LWL - Archaeologie fuer Westfalen, Muenster (Germany)

    2013-04-15

    We have investigated four stained glass samples recovered from an archaeological excavation at the Cathedral in Paderborn (Germany) between 1978 and 1980. On two of the samples there are parts of paintings. Concentrations of major elements were determined using two independent techniques: LA-ICP-MS (a UV laser ablation microsampler combined with an inductively coupled plasma mass spectrometer) and synchrotron radiation X-ray excited X-ray fluorescence (SR-XRF). The SR-XRF data were quantified by using the program package PyMCA developed by the software group of the ESRF in Grenoble. Significant differences were found between the concentrations determined by the two techniques that can be explained by concentration gradients near the surface of the glasses caused, for example, by corrosion/leaching processes and the different surface sensitivities of the applied techniques. For several of the elements that were detected in the glass and in the colour pigments used for the paintings X-ray absorption near edge structure (XANES) spectra were recorded in order to determine the chemical speciation of the elements of interest. As was expected, most elements in the glass were found as oxides in their most stable form. Two notable exceptions were observed: titanium was not found as rutile - the most stable form of TiO{sub 2} - but in the form of anatase, and lead was not found in one defined chemical state but as a complex mixture of oxide, sulphate, and other compounds. (orig.)

  8. Toxicological detection of the designer drug 3,4-methylenedioxyethylamphetamine (MDE, "Eve") and its metabolites in urine by gas chromatography-mass spectrometry and fluorescence polarization immunoassay.

    Science.gov (United States)

    Ensslin, H K; Kovar, K A; Maurer, H H

    1996-08-30

    Studies are presented on the toxicological detection of the designer drug methylenedioxyethylamphetamine [MDE, rac-N-ethyl-(3,4-methylenedioxyphenyl)-propane-2-amine] in urine after a single oral dose of 140 mg of MDE by GC-MS and fluorescence polarization immunoassay (FPIA). After acid hydrolysis, extraction and acetylation MDE and its metabolites could be detected by mass chromatography with the selected ions m/z 72, 86, 114, 150, 162 and 164, followed by identification of the peaks underlying full mass spectra by computer library search. The following metabolites could be detected: unchanged MDE and 3,4-dihydroxyethylamphetamine (DHE) for 33-62 h, 3,4-methylenedioxyamphetamine (MDA) for 32-36 h and 4-hydroxy-3-methoxyethylamphetamine (HME) for 7-8 days. 3,4-Dihydroxyamphetamine (DHA), 4-hydroxy-3-methoxyamphetamine (HMA), piperonyl acetone, 3,4-dihydroxyphenyl acetone and 4-hydroxy-3-methoxyphenyl acetone could only be detected in trace amounts within the first few hours. The Abbott TD x FPIA assay amphetamine/metamphetamine II gave positive results in urine for 33-62 h. Therefore, positive immunoassay results could be confirmed by the GC-MS procedure which also allowed the differentiation of MDE and its homologues 3,4-methylenedioxymethamphetamine (MDMA) and MDA as well as other amphetamine derivatives interfering with the TD x assay. Furthermore, this GC-MS procedure allowed the simultaneous detection of most of the toxicologically relevant drugs.

  9. Studies on the metabolism and toxicological detection of the amphetamine-like anorectic fenproporex in human urine by gas chromatography-mass spectrometry and fluorescence polarization immunoassay.

    Science.gov (United States)

    Kraemer, T; Theis, G A; Weber, A A; Maurer, H H

    2000-01-28

    Studies on the metabolism and the toxicological analysis of fenproporex (R,S-3-[(1-phenyl-2-propyl)-amino]-propionitrile, FP) using GC-MS and fluorescence polarization immunoassay are described. The metabolites were identified in urine samples of volunteers by GC-MS after cleavage of conjugates, extraction and acetylation. Besides unchanged FP, fourteen metabolites, including amphetamine, could be identified. Two partially overlapping metabolic pathways could be postulated: ring degradation by one- and two-fold aromatic hydroxylation followed by methylation and side chain degradation by N-dealkylation to amphetamine (AM). A minor pathway leads via beta-hydroxylation of AM to norephedrine. For GC-MS detection, the systematic toxicological analysis procedure including acid hydrolysis, extraction at pH 8-9 and acetylation was suitable (detection limits 50 ng/ml for FP and 100 ng/ml for AM). Excretion studies showed, that only AM but neither FP nor its specific metabolites were detectable 30-60 h after ingestion of 20 mg of FP. Therefore, misinterpretation can occur. The Abbott TDx FPIA amphetamine/methamphetamine II gave positive results up to 58 h. All the positive immunoassay results could be confirmed by the described GC-MS procedure.

  10. Rapid quantitative determination of major and trace elements in silicate rocks and soils employing fused glass discs using wavelength dispersive X-ray fluorescence spectrometry

    Science.gov (United States)

    Krishna, A. Keshav; Khanna, Tarun C.; Mohan, K. Rama

    2016-08-01

    This paper introduces a calibration procedure and provides the data achieved for accuracy, precision, reproducibility and the detection limits for major (Si, Al, Fe, Mn, Mg, Ca, Na, K, Ti, P) and trace (Ba, Cr, Cu, Hf, La, Nb, Ni, Pb, Rb, Sr, Ta, Th, U, Y, Zn, Zr) elements in the routine analysis of geological and environmental samples. Forty-two rock and soil reference materials were used to calibrate and evaluate the analytical method using a sequential wavelength dispersive X-ray fluorescence spectrometer. Samples were prepared as fused glass discs and analysis performed with a total measuring time of thirty-one minutes. Another set of twelve independent reference materials were analyzed for the evaluation of accuracy. The detection limits and accuracy obtained for the trace elements (1-2 mg/kg) are adequate both for geochemical exploration and environmental studies. The fitness for purpose of the results was also evaluated by the quality criteria test proposed by the International Global Geochemical Mapping Program (IGCP) from which it can be deduced that the method is adequate considering geochemical mapping application and accuracy obtained is within the expected interval of certified values in most cases.

  11. Enantioselective determination of metoprolol and its metabolites in human urine high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and tandem mass spectrometry (MS/MS).

    Science.gov (United States)

    Baranowska, Irena; Adolf, Weronika; Magiera, Sylwia

    2015-11-01

    A sensitive, stereoselective assay using solid phase extraction and high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) was developed and validated for the analysis of enantiomers of metoprolol and its metabolites (α-hydroxymetoprolol, O-desmethylmetoprolol). Chiral separation was achieved using a CHIRALCEL OD-RH column, packed with cellulose tris-(3,5-dimethylphenyl-carbamate) stationary phase, employing a mobile phase composed by a mixture of 0.2% diethylamine in water and acetonitrile in gradient elution mode. Linear calibration curves were obtained over the range of 0.025-2.0μg/mL (R(2)>0.994) in urine for both enantiomers of metoprolol and its metabolites with quantitation limit of 0.025μg/mL. Intra and inter-day precision and accuracy were below 15% for both metoprolol and metabolites enantiomers. The recovery of enantiomer of metoprolol and its metabolite was greater than 68.0%, utilizing a SPE procedure. The method was tested with urine quality control samples and human urine fractions after administration of 50mg rac-metoprolol.

  12. Investigation of the Distribution of Elements in Snail Shell With the use of Synchrotron-Based, Micro-Beam X-ray Fluorescence Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Rao, D.; Swapna, M; Cesareo, R; Brunetti, A; Akatsuka, T; Yuasa, T; Takeda, T; Tromba, G; Gigante, G

    2009-01-01

    In this study, synchrotron-based micro-beam was utilized for elemental mapping of a small animal shell. A thin X-ray spot of the order of {approx}10 em was focused on the sample. With this spatial resolution and high flux throughput, the X-ray fluorescent intensities for Ca, Mn, Fe, Ni, Zn, Cr and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive HpGe detector. The sample is scanned in a estep-and-repeat' mode for fast elemental mapping and generated elemental maps at 8, 10 and 12 keV. All images are of 10 em resolution and the measurement time was 1 s per point. The accumulation of trace elements was investigated from the soft-tissue in small areas. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other trace elements.

  13. TDDFT investigation of the electronic structures and photophysical properties of fluorescent extended styryl push-pull chromophores containing carbazole unit.

    Science.gov (United States)

    Gupta, Vinod D; Tathe, Abhinav B; Padalkar, Vikas S; Patil, Vikas S; Phatangare, Kiran R; Umape, Prashant G; Ramasami, Ponnadurai; Sekar, Nagaiyan

    2013-11-01

    Push-pull chromophores attached to carbazole based π-conjugating spacers bearing N-alkylamino donors, cyanovinyl and carbethoxy acceptors have been studied by the means of UV-Visible measurements. The intramolecular charge transfer (ICT) of these π-conjugated systems has also been tested by investigating the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. Density Functional Theory [B3LYP/6-31G(d)] and Time Dependent Density Functional Theory [TD-B3LYP/6-31G(d)] computations have been used to have more understanding of the structural, molecular, electronic and photophysical parameters of push-pull dyes. The largest wavelength difference between the experimental and computed electronic absorption maxima was 45 nm. For emission, a largest difference of 61 nm was observed. The ground state and excited state dipole moments in different solvents were determined using experimental solvatochromic data and computed Onsager radii. The dipole moments of the molecules in the excited state were observed to be higher than in the ground state.

  14. The Determination of Arsenic in Food Additive Phosphoric Acid by Atomic Fluorescence Spectrometry%原子荧光光谱法测定食品添加剂磷酸中的砷

    Institute of Scientific and Technical Information of China (English)

    陈泉; 邵青松

    2012-01-01

    This paper established the determination of arsenic in food additive phosphoric acid by Atomic fluorescence spectrometry, and the maximum of the relative standard deviation in arsenic test is 3.07%, the recovery rate was 98.7% - 101.2%, the detection limit is 0.09 μg/L; this method is easy operation, rapid, accurate, high sensitivity, worth popularizing in terms of relatively GB3149 -2004 《food additive phosphoric acid》 national standard method for the determination of arsenic.%建立了测定食品添加剂磷酸中砷的原子荧光光谱法,测试中砷的相对标准偏差最高为3.07%,回收率在98.7%-101.2%之间、检出限为0.09μg/L;本法相对GB3149-200k4《食品添加剂磷酸》国家标准中砷的测定方法而言操作简便、快速、准确、灵敏度高,值得推广。

  15. 血液和尿液中砷的原子荧光光度测定法%Determination of arsenic in blood and urine by atom fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    徐燕

    2012-01-01

    [Objective]To explore the optimal method for determining arsenic in blood and urine. [Methods]The determination of arsenic in blood and urine was performed by microwave digest-hydride generation atom fluorescence spectrometry. [Results] Under the optimum condition, the limit of arsenic detection was 0.076 8 jJLg/L; the recoveries were 89.0-103.7% ; RSD was 2.4-5.1%. [Conclusion]The method is simple, rapid, sensitive with less interference and wide linear range.%目的 探讨血液和尿液中砷的最佳测定方法.方法 采用微波消解氢化物发生原子荧光光度法测定血液和尿液中的砷.结果 在最佳条件下砷的最低检出限为0.076 8μg/L,砷回收率为89.0%~103.7%,RSD为2.4 ~5.1%.结论 该方法具有简便,快速,灵敏度高,干扰少,线性范围宽等优点.

  16. Simultaneous determination of arsenic and mercury in polyaluminum chloride by atomic fluorescence spectrometry method%原子荧光光谱法同时测定聚氯化铝中的砷和汞

    Institute of Scientific and Technical Information of China (English)

    秦晓鹏; 吴锴; 陶福棠; 李凯

    2013-01-01

    Application of hydride generation-atomic fluorescence spectrometry method in the simultaneous determination of arsenic and mercury in polyaluminium chloride used for drinking water was studied.This method is of high sensitivity and good accuracy.Under optimal conditions,the potassium borohydride concentration,detection limit,precision,and recovery rate were investigated.Results showed:the detection limits of arsenic and mercury were 0.007 9 μg/L and 0.002 6 g/L, respectively: the recovery rates of arsenic and mercury were 93.75%~103.83% and 105.00%~108.75%, respectively.%研究了应用氢化物发生-原子荧光光谱法同时测定生活饮用水用聚氯化铝中的砷和汞,方法灵敏度高、准确度好在最佳条件下,对硼氢化钾浓度、检出限、精密度、加标回收率等进行了研究.结果表明:方法的检出限砷为0.007 9 μg/L、汞为0.002 6 μg/L,砷、汞的加标回收率分别为93.75%~103.83%和105.00%~ 108.75%.

  17. On the element dispersion of Oker river sediments (Lower Saxony); investigations by X-ray fluorescence spectrometry. Zur Element-Dispersion an Flusssedimenten der Oker (Niedersachsen); roentgenfluoreszenz-spektrometrische Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Matschullat, J. (Inst. fuer Mineralogie und Mineralische Rohstoffe, TU Clausthal, Clausthal-Zellerfeld (Germany)); Niehoff, N.; Poertge, K.H. (Geographisches Inst., Goettingen Univ. (Germany))

    1991-01-01

    Sediments (< 63 [mu]m) of the partly contaminated Oker river were investigated in a profile from its source in the upper Harz mountains to its mouth in the Aller river by X-ray-fluorescence spectrometry. Two analytical programs for the calculation of XRF-intensities (UniQuant and OxiQuant) are compated and their respective applications are briefly discussed. The results of both programs are generally in good agreement. As (4.100), Ba (6.600), Cu (1.200), Mo (270), Nb (280), Ni (150), Pb (15.000), and Zn (21.000) show variations to two oders of magnitude and distinct local influences (maximum concentrations in mg/kg). Ce (200), Co (150), Cr (180), Ga (90), Sn (120), Sr (200) and Zr (2.300), together with P (5.700), are enriched up to one order of magnitude. Trends or obvious local influences can be distinguished. La, Nd, Pr, Rb, Sc, Sm, Th, U, V, and Y, like all major and most secondary elements do not show trends. The variations of the concentrations are [+-] 30% from the regional background. Data for the regional geogenic background of the stream sediments are presented for the first time. (orig./EF).

  18. Iodine Content and Distribution in Thyroid Specimens from Two Patients with Graves' Disease Pretreated with Either Propylthiouracil or Stable Iodine: Analysis Using X-Ray Fluorescence and Time-of-Flight Secondary Ion Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Marie Hansson

    2012-01-01

    Full Text Available Patients with Graves' disease can be medically prepared before surgery in different ways, which may have various effects on iodine stores. Thyroid specimens were collected at surgery from two patients pretreated with propylthiouracil (PTU and stable iodine, respectively. A quantitative analysis of iodine content was performed using X-ray fluorescence (XRF in frozen tissue and a qualitative analysis of aldehyde-fixed material with Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS. Iodine concentrations were 0.9 mg/mL and 0.5 mg/mL in the thyroid tissue from the patients treated with PTU and stable iodine respectively. TOF-SIMS showed iodine in the follicle lumina in both. However, in the PTU case, iodine was also seen within the thyrocytes indicating accumulation of iodinated compounds from uninhibited hormone release. XRF and TOF-SIMS can be used to follow iodine distribution within the thyroid and the intricate processes following the different medical treatment alternatives in Graves' disease.

  19. Using portable X-ray fluorescence spectrometry and GIS to assess environmental risk and identify sources of trace metals in soils of peri-urban areas in the Yangtze Delta region, China.

    Science.gov (United States)

    Ran, Jing; Wang, Dejian; Wang, Can; Zhang, Gang; Yao, Lipeng

    2014-08-01

    Portable X-ray fluorescence (PXRF) spectrometry may be very suitable for a fast and effective environmental assessment and source identification of trace metals in soils. In this study, topsoils (0-10 cm) at 139 sites were in situ scanned for total trace metals (Cr, Cu, Ni, Pb and Zn) and arsenic concentrations by PXRF in a typical town in Yangtze Delta region of Jiangsu province, China. To validate the utility of PXRF, 53 samples were collected from the scanning sites for the determination of selected trace metals using conventional methods. Based on trace metal concentrations detected by in situ PXRF, the contamination extent and sources of trace metals were studied via geo-accumulation index, multivariate analysis and geostatistics. The trace metal concentrations determined by PXRF were similar to those obtained via conventional chemical analysis. The median concentration of As, Cr, Cu, Ni, Pb and Zn in soils were 10.8, 56.4, 41.5, 43.5, 33.5, and 77.7 mg kg(-1), respectively. The distribution patterns of Cr, Cu, Ni, Pb, and Zn were mostly affected by anthropogenic sources, while As was mainly derived from lithogenic sources. Overall, PXRF has been successfully applied to contamination assessment and source identification of trace metals in soils.

  20. A new technique for the deposition of standard solutions in total reflection X-ray fluorescence spectrometry (TXRF) using pico-droplets generated by inkjet printers and its applicability for aerosol analysis with SR-TXRF

    Energy Technology Data Exchange (ETDEWEB)

    Fittschen, U.E.A. [University of Hamburg, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)]. E-mail: ursula.fittschen@chemie.uni-hamburg.de; Hauschild, S. [University of Hamburg, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Amberger, M.A. [University of Hamburg, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Lammel, G. [Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg (Germany); Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Foerster, S. [University of Hamburg, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Wobrauschek, P. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Jokubonis, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Vienna (Austria); Pepponi, G. [ITC-irst, Via Sommarive 18, 38050 Povo (Trento) (Italy); Falkenberg, G. [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22603 Hamburg (Germany); Broekaert, J.A.C. [University of Hamburg, Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

    2006-11-15

    A new technique for the deposition of standard solutions on particulate aerosol samples using pico-droplets for elemental determinations with total reflection X-ray fluorescence spectrometry (TXRF) is described. It enables short analysis times without influencing the sample structure and avoids time consuming scanning of the sample with the exciting beam in SR-TXRF analysis. Droplets of picoliter volume ({approx} 5-130 pL) were generated with commercially available and slightly modified inkjet printers operated with popular image processing software. The size of the dried droplets on surfaces of different polarity namely silicone coated and untreated quartz reflectors, was determined for five different printer types and ten different cartridge types. The results show that droplets generated by inkjet printers are between 50 and 200 {mu}m in diameter (corresponding to volumes of 5 to 130 pL) depending on the cartridge type, which is smaller than the width of the synchrotron beam used in the experiments (< 1 mm at an energy of 17 keV at the beamline L at HASYLAB, Hamburg). The precision of the printing of a certain amount of a single element standard solution was found to be comparable to aliquoting with micropipettes in TXRF, where for 2.5 ng of cobalt relative standard deviations of 12% are found. However, it could be shown that the printing of simple patterns is possible, which is important when structured samples have to be analysed.

  1. Hot-water and solid-phase extraction of fluorescent whitening agents in paper materials and infant clothes followed by unequivocal determination with ion-pair chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Chen, Hsin-Chang; Ding, Wang-Hsien

    2006-03-10

    A comprehensive method for the determination of four stilbene-type disulfonate and one distyrylbiphenyl-type fluorescent whitening agents (FWAs) in paper materials (napkin and paper tissue) and infant clothes was developed. FWAs were extracted from paper material and cloth samples using a hot-water extraction, and the aqueous extracts were then preconcentrated with the newly developed Oasis WAX (mixed-mode of weak anion exchange and reversed-phase sorbent) solid-phase extraction cartridge. The analytes were unequivocal determined by ion pair chromatography coupled with negative electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS-MS), applying a di-n-hexyl-ammonium acetate (DHAA) as the ion-pairing reagent in mobile phase. Limits of quantitation (LOQ) were established between 0.2 and 0.9 ng/g in 2 g of samples. Recovery of five FWAs in spiked commercial samples was between 42 and 95% and RSD (n = 3) ranging from 2 to 11%. The method was finally applied to commercial samples, showing that two stilbene-type disulfonates were predominant FWAs detected in napkin and infant cloth samples.

  2. 氢化物发生-原子荧光光谱法测定红土镍矿中砷%DETERMINATION OF ARSENIC IN LATERITE NICKEL ORES BY HYDRIDE GENERATION-ATOMIC FLUORESCENCE SPECTROMETRY

    Institute of Scientific and Technical Information of China (English)

    陈殿耿; 袁玉霞; 何飞顶

    2012-01-01

    提出了以硫脲-抗坏血酸作为还原掩蔽剂,氢化物发生-原子荧光光谱法( HG-AFS)直接测定红土镍矿中砷的方法.考察了测定的最佳条件、共存元素对测定的影响及方法的精密度和回收率.方法适用于红土镍矿中0.005%~0.1%砷的测定.%A method for the determination of arsenic in laterite nickel ores by hydride generation-atomic fluorescence spectrometry (HG-AFS) directly with thiourea-ascorbic acid hydrochloride as masking is proposed. The optimum experimental parameters, the effect of coexistent elements on the determination of arsenic, the precision and recovery of the method are investigated. The method can be applied to the determination of 0. 005% ~ 0. 1% arsenic in laterite nickel ores.

  3. A simple and sensitive flow-injection on-line preconcentration coupled with hydride generation atomic fluorescence spectrometry for the determination of ultra-trace lead in water, wine, and rice.

    Science.gov (United States)

    Wu, Hong; Jin, Yan; Luo, Mingbiao; Bi, Shuping

    2007-09-01

    A simple and sensitive flow-injection on-line separation and preconcentration system coupled to hydride generation atomic fluorescence spectrometry (HG-AFS) was developed for ultra-trace lead determination in water, wine, and rice samples, with the salient advantages of its minimization of transition-metal interferences and tolerance to an ethanol matrix. A lead hydroxide precipitate was achieved by the on-line merging of a sample and an ammonium buffer solution and collected onto the inner walls of a knotted reactor (KR). Removal of the residual solution from KR was achieved by air flow, and dissolution of the precipitate was carried out by using 0.2 mol l(-1) HCl. With a sample consumption of 11.7 ml, an enhancement factor of 16 was obtained at a sample throughput of 30 h(-1). The limit of detection (3s) was 16 ng l(-1) and the precision (RSD) for 1.0 microg l(-1) Pb was 3.4%.

  4. Speciation analysis of mercury in sediments, zoobenthos and river water samples by high-performance liquid chromatography hyphenated to atomic fluorescence spectrometry following preconcentration by solid phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Margetinova, Jana; Houserova-Pelcova, Pavlina [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, Brno CZ 613 00 (Czech Republic); Kuban, Vlastimil [Department of Chemistry and Biochemistry, Mendel University of Agriculture and Forestry, Zemedelska 1, Brno CZ 613 00 (Czech Republic)], E-mail: kuban@mendelu.cz

    2008-05-19

    A high-pressure microwave digestion was applied for microwave-assisted extraction (MAE) of mercury species from sediments and zoobenthos samples. A mixture containing 3 mol L{sup -1} HCl, 50% aqueous methanol and 0.2 mol L{sup -1} citric acid (for masking co-extracted Fe{sup 3+}) was selected as the most suitable extraction agent. The efficiency of proposed extraction method was better than 95% with R.S.D. below 6%. A preconcentration method utilizing a 'homemade' C18 solid phase extraction (SPE) microcolumns was developed to enhance sensitivity of the mercury species determination using on-column complex formation of mercury-2-mercaptophenol complexes. Methanol was chosen for counter-current elution of the retained mercury complexes achieving a preconcentration factor as much as 1000. The preconcentration method was applied for the speciation analysis of mercury in river water samples. The high-performance liquid chromatography-cold vapour atomic fluorescence spectrometric (HPLC/CV-AFS) method was used for the speciation analysis of mercury. The complete separation of four mercury species was achieved by an isocratic elution of aqueous methanol (65%/35%) on a Zorbax SB-C18 column (4.6 mm x 150 mm, 5 {mu}m) using the same complexation reagent (2-mercaptophenol). The limits of detection were 4.3 {mu}g L{sup -1} for methylmercury (MeHg{sup +}), 1.4 {mu}g L{sup -1} for ethylmercury (EtHg{sup +}), 0.8 {mu}g L{sup -1} for inorganic mercury (Hg{sup 2+}), 0.8 {mu}g L{sup -1} for phenylmercury (PhHg{sup +})

  5. Investigating Early/Middle Bronze Age copper and bronze axes by micro X-ray fluorescence spectrometry and neutron imaging techniques

    Science.gov (United States)

    Figueiredo, Elin; Pereira, Marco A. Stanojev; Lopes, Filipa; Marques, José G.; Santos, Joana P.; Araújo, M. Fátima; Silva, Rui J. C.; Senna-Martinez, João C.

    2016-08-01

    Micro X-ray fluorescence (micro-XRF) analysis and neutron imaging techniques, namely 2D radiography and 3D tomography, have been applied for the study of four metal axes from the Early/Middle Bronze Age in Western Iberia, a period characterized by a metallurgical change in the use of copper to bronze. Micro-XRF analysis has shown that one of the axes was produced in copper with some arsenic while the other three were produced in a copper-tin alloy (bronze) with variable tin contents and some arsenic and lead. Neutron radiography and tomography were applied to study internal heterogeneities of the axes in a non-invasive way since the specificities of neutron interaction with matter allow a suitable penetration of these relatively thick copper-based objects when compared to the use of a conventional X-ray radiography. Neutron imaging allowed the visualization of internal fissures and pores and the evaluation of their distribution, size and shape. Relevant information for the reconstruction of ancient manufacturing techniques was gathered, revealing that one ax was produced with the mold in an angle of ≈ 25°, probably to facilitate gas escape during metal pouring. Also, information regarding physical weaknesses of the axes was collected, providing relevant data for their conservation. The combination of these non-destructive techniques allowed the evaluation of the metal composition and the internal structure of the axes. Micro-XRF allowed the distinction among copper and bronze axes, and provided data about the composition of early bronzes for which data is scarce. The neutron imaging study allowed for the first time the visualization of internal heterogeneities in early bronze axes, namely pores and large voids, providing relevant information for the reconstruction of ancient manufacturing techniques and raising pertinent information regarding physical weaknesses of these types of objects.

  6. Rapid resolution liquid chromatography-mass spectrometry and high-performance liquid chromatography-fluorescence detection for metabolism and pharmacokinetic studies of ergosta-4,6,8(14),22-tetraen-3-one.

    Science.gov (United States)

    Zhao, Ying-Yong; Qin, Xiang-Yang; Cheng, Xian-Long; Liu, Xue-Ying; Lin, Rui-Chao; Zhang, Yongmin; Li, Xiao-Ye; Sun, Xiao-Li; Sun, Wen-Ji

    2010-08-24

    Ergosta-4,6,8(14),22-tetraen-3-one (ergone) from many medicinal plants has been demonstrated to possess a variety of pharmacological activities in vivo and in vitro, including cytotoxic, diuretic and immunosuppressive activity. Metabolism and pharmacokinetic studies on rat were conducted for ergone. Rapid resolution liquid chromatography with atmospheric pressure chemical ionization tandem multi-stage mass spectrometry (RRLC-APCI-MS(n)) and high-performance liquid chromatography with fluorescence detection (HPLC-FLD) methods were applied for the identification and quantification of ergone and its metabolite from rat plasma, faeces and urine. A metabolite was identified by RRLC-DAD-APCI-MS(n): 22,23-epoxy-ergosta-4,6,8(14)-triaen-3-one (epoxyergone). The concentrations of the analyte with its metabolites were determined by HPLC-FLD at excitation wavelength of 370 nm and emission wavelength of 485 nm. The samples were deproteinized with methanol after addition of camptothecin as internal standard (IS). The analysis was performed on a Diamonsil C18 column (150 mm x 4.6 mm x 5 microm) with a mobile phase gradient consisting of methanol and water at a flow rate of 1 mL min(-1). The assay was linear over the concentration range of 42-1500, 36-7500 and 42-1500 ng mL(-1) for plasma, faecal homogenate and urine respectively. The absolute recoveries were found to be 97.0+/-1.2%, 98.1+/-0.7% and 96.6+/-1.8% for plasma, faecal homogenate and urine respectively. The intra-day and inter-day relative standard deviations (RSD) were less than 10%. The previous HPLC-MS/MS method is not affordable for most laboratories because of the specialty requirement and high equipment cost. However, the HPLC-FLD method is economic and operating simply for quantitative determination of ergone and its metabolite in rat plasma, faeces and urine. In addition, liquid chromatography coupled with ion trap multi-stage mass spectrometry is becoming a useful technique for ergone metabolite identification.

  7. Determination of arsenic and mercury in the rice by microwave digestion-atomic fluorescence spectrometry%大米中砷和汞的微波消解-原子荧光光谱测定法

    Institute of Scientific and Technical Information of China (English)

    李树雄; 张荣

    2012-01-01

    目的 建立双道原子荧光光谱法同时测定大米中的砷和汞的方法.方法 采用微波消解法处理大米样品,以原子荧光光谱法同时测定其中的砷和汞.结果 砷和汞的检出限分别为0.0044、0.039 μg/L;砷、汞标准溶液分别在1.0 ~20.0和0.10 ~1.20 μg/L范围内线性良好,其相关系数分别为0.9995、0.9992;精密度RSD:测定含2.0 μg/L砷和0.4 μg/L汞的混合标准溶液的RSD分别为2.12% 、4.59%.样品加标回收率:砷92.2% ~96.8%,汞90.3% ~92.1%.结论 该方法灵敏度、准确度高,操作方便快速,具有较低的检出限,能满足同时测定大米中砷和汞含量的测定工作.%[Objective ] To establish the method for simultaneous determination of trace arsenic and mercury in rice by dual-channel atomic fluorescence spectrometry. [Methods] The rice samples was digested by microwave, then the trace arsenic and mercury were simultaneously determined by Atomic fluorescence spectrometry. [ Results] The detection limits were 0.004 4 (μg/L for arsenic and 0.039 (μg/L for mercury; there was a linear relationship between 1.0-20.0 μg/L of arsenic standard solution, 0.10-1.20 (μg/L of mercury standard solution. The correlation coefficients were 0.999 5 for arsenic and 0.999 2 for mercury. The precision RSD was 2.12% for 2.0 μg/L arsenic mixed standard solution, and 4.59% for 0.4 μg/L mercury mixed standard solution. The recoveries were 92.2%-96.8% for arsenic and 90.3%-92.1% for mercury. [Conclusion]This method is very sensitive, with high accuracy, easy and fast. It has lower detecting limit, and can determine the content of Arsenic and Mercury in rice simultaneously

  8. Simultaneous Determination of Arsenic and Antimony in Water by Hydride Generation-Atomic Fluorescence Spectrometry%氢化物发生-原子荧光光谱法同时测定水中砷和锑

    Institute of Scientific and Technical Information of China (English)

    黄选忠; 万忠卫; 杜宏山; 郑丽

    2013-01-01

    建立在硝酸介质中用氢化物发生-原子荧光光谱法同时测定水中砷和锑的方法。优化了仪器工作条件、酸度、硼氢化钾及还原剂浓度。砷、锑的线性范围为0~10.0µg/L;检出限分别为0.02,0.01µg/L;测定结果的相对标准偏差分别为1.77%~3.72%,2.95%~4.87%(n=6);加标回收率分别为98%~106%,96%~105%。该法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定。%The method for simultaneous determination of arsenic and antimony in water was established by hydride-generation atomic fluorescence spectrometry in nitric acid medium. Instrument condition,acidity,concentration of potassium borohydride and thiourea-ascorbic acid were selected. The linear relationship of arsenic and antimony was 0-10.0 µg/L. The detection limit of arsenic and antimony was 0.02 µg/L and 0.01 µg/L, the relative standard deviation of arsenic and antimony determination results was 1.77%-3.72%and 2.95%-4.87%(n=6) , the recovery of standard addition of arsenic and antimony was 98%-106%and 96%-105%respectively. This method has the advantages of simple operation and high sensitivity,it is rapid and easy to spread,which is suitable for simultaneous determination of arsenic and antimony in water.

  9. Rapid, sensitive and simultaneous determination of fluorescence-labeled designated substances controlled by the Pharmaceutical Affairs Law in Japan by ultra-performance liquid chromatography coupled with electrospray-ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Min, Jun Zhe; Hatanaka, Suguru; Toyo'oka, Toshimasa; Inagaki, Shinsuke; Kikura-Hanajiri, Ruri; Goda, Yukihiro

    2009-11-01

    A simultaneous determination method based on ultra-performance liquid chromatography (UPLC) with fluorescence (FL) detection and electrospray-ionization time-of-flight mass spectrometry (ESI-TOF-MS) was developed for 16 "designated substances" (Shitei-Yakubutsu) controlled by the Pharmaceutical Affairs Law in Japan. These substances were first labeled with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole at 60 degrees C for 2 h in 0.1 M borax (pH 9.3). The resulting fluorophores were well separated by reversed-phase chromatography using an Acquity UPLC BEH C(18) column (1.7 microm, 100 mm x 2.1 mm i.d.) by isocratic elution with a mixture of water and acetonitrile-methanol (20:80) containing 0.1% formic acid. The separated derivatives were sensitively detected by both FL and TOF-MS. However, the determination of several designated substances by FL detection showed interference from endogenous substances in biological samples. Therefore, the determination in real samples was carried out by a combination of UPLC separation and ESI-TOF-MS detection. The structures of the designated substances were identified from the protonated-molecular ions [M+H](+) obtained from the TOF-MS measurement. The calibration curves obtained from the peak area ratios of the internal standard (I.S.), i.e., 3-phenyl-1-propylamine, and the designated substances versus the injection amounts showed good linearity. The limits of detection (S/N = 3) and the limits of quantification (S/N = 10) in 0.1 mL of human plasma and urine for the present method were 0.30-150 pmol and 1.0-500 pmol, respectively. Good accuracy and precision (according to intraday and interday assays) were also obtained with the present procedure. This method was applied to analyses of human plasma, urine and real products.

  10. Determination of Se in Saffron by Using Hydride Generation Atomic Fluorescence Spectrometry%氢化物发生原子荧光光谱法测定西红花柱头中的硒

    Institute of Scientific and Technical Information of China (English)

    张宏; 张新申; 颜钫; 陈放

    2001-01-01

    A method for determination of Se in saffron using AFS-230 hydride generation atomic fluorescence spectrometry was introduced.Detections were completed made in every possible best condition.The optimal analytical conditions in HClO4-HNO3 were examined.The detection limit is 0.5μg/L.The linear range is 1.5~15.0 μg/L.The correlation coefficient is 0.9999,and the recovery rate is about 90%~97%.Se of saffrons from 4 regions was determined by standard curve method.The experiment results show that this method has low detection limit,high accurate,simple operation,fast and low cost.It's easy to be spread.%应用AFS-230型双道原子荧光光谱计进行了氢化物发生原子荧光光谱法测定西红花柱头中硒的研究,方法中采用硝酸做介质,并对各种最佳分析条件进行了测定。线性范围为1.5~15μg/L,相关系数R=0.9999,回收率为90%~97%。采用标准曲线法对4种不同产地的西红花干燥柱头中硒进行了测定。该方法操作简单、快速,精密度好,准确性高,检出限较低,经济,便于推广应用。

  11. Rapid discrimination of Haemophilus influenzae, H. parainfluenzae, and H. haemolyticus by fluorescence in situ hybridization (FISH and two matrix-assisted laser-desorption-ionization time-of-flight mass spectrometry (MALDI-TOF-MS platforms.

    Directory of Open Access Journals (Sweden)

    Hagen Frickmann

    Full Text Available BACKGROUND: Due to considerable differences in pathogenicity, Haemophilus influenzae, H. parainfluenzae and H. haemolyticus have to be reliably discriminated in routine diagnostics. Retrospective analyses suggest frequent misidentifications of commensal H. haemolyticus as H. influenzae. In a multi-center approach, we assessed the suitability of fluorescence in situ hybridization (FISH and matrix-assisted laser-desorption-ionization time-of-flight mass-spectrometry (MALDI-TOF-MS for the identification of H. influenzae, H. parainfluenzae and H. haemolyticus to species level. METHODOLOGY: A strain collection of 84 Haemophilus spp. comprising 50 H. influenzae, 25 H. parainfluenzae, 7 H. haemolyticus, and 2 H. parahaemolyticus including 77 clinical isolates was analyzed by FISH with newly designed DNA probes, and two different MALDI-TOF-MS systems (Bruker, Shimadzu with and without prior formic acid extraction. PRINCIPAL FINDINGS: Among the 84 Haemophilus strains analyzed, FISH led to 71 correct results (85%, 13 uninterpretable results (15%, and no misidentifications. Shimadzu MALDI-TOF-MS resulted in 59 correct identifications (70%, 19 uninterpretable results (23%, and 6 misidentifications (7%, using colony material applied directly. Bruker MALDI-TOF-MS with prior formic acid extraction led to 74 correct results (88%, 4 uninterpretable results (5% and 6 misidentifications (7%. The Bruker MALDI-TOF-MS misidentifications could be resolved by the addition of a suitable H. haemolyticus reference spectrum to the system's database. In conclusion, no analyzed diagnostic procedure was free of errors. Diagnostic results have to be interpreted carefully and alternative tests should be applied in case of ambiguous test results on isolates from seriously ill patients.

  12. Trace and ultratrace determination of heavy metal ions by energy-dispersive X-ray fluorescence spectrometry using graphene as solid sorbent in dispersive micro solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Kocot, Karina; Sitko, Rafal, E-mail: rafal.sitko@us.edu.pl

    2014-04-01

    In this paper, the adsorptive properties of graphene nanosheets were used for simultaneous preconcentration of cobalt, nickel, copper and lead ions from water samples. The developed methodology is based on dispersive micro-solid phase extraction (DMSPE) which is miniaturized and a simplified version of classical solid phase extraction technique. In proposed procedure only 200 μL of suspension containing graphene (0.2 mg), ammonium pyrrolidine dithiocarbamate (APDC) (0.8 mg) and Triton-X-100 (0.1 mg) is rapidly injected to 50 mL of water sample. Then, graphene nanosheets with adsorbed metal-APDC chelates are collected on membrane filter and measured using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The various parameters including pH, amount of APDC, sample volume, amount of Triton-X-100 and sorption time were optimized in order to obtain the best recoveries. The experiment shows that Co, Ni, Cu and Pb can be simultaneously preconcentrated at pH of 5 with high recoveries (97%, 96%, 99% and 96% for Co, Ni, Cu and Pb, respectively) and very good precision (RSDs within 2.6–3.4%). Due to the excellent enrichment factors ranging from 400 to 2500 the proposed DMSPE–EDXRF procedure offers low detection limits. For optimized measurement conditions (voltage and current of X-ray tube, primary beam filter) the detection limits are even 0.08, 0.07, 0.08 and 0.20 ng mL{sup −1} for Co, Ni, Cu and Pb, respectively. - Highlights: • Excellent detection limits using EDXRF • A new preconcentration procedure combining DMSPE and EDXRF measurement • Graphene as a promising and efficient solid sorbent in DMSPE • Simple, fast, inexpensive and environmental friendly method.

  13. Simultaneous speciation of inorganic arsenic and antimony in water samples by hydride generation-double channel atomic fluorescence spectrometry with on-line solid-phase extraction using single-walled carbon nanotubes micro-column

    Energy Technology Data Exchange (ETDEWEB)

    Wu Hong, E-mail: wuhong1968@hotmail.com; Wang Xuecui; Liu Bing; Liu Yueling; Li Shanshan; Lu Jusheng; Tian Jiuying; Zhao Wenfeng; Yang Zonghui

    2011-01-15

    A new method was developed for the simultaneous speciation of inorganic arsenic and antimony in water by on-line solid-phase extraction coupled with hydride generation-double channel atomic fluorescence spectrometry (HG-DC-AFS). The speciation scheme involved the on-line formation and retention of the ammonium pyrrolidine dithiocarbamate complexes of As(III) and Sb(III) on a single-walled carbon nanotubes packed micro-column, followed by on-line elution and simultaneous detection of As(III) and Sb(III) by HG-DC-AFS; the total As and total Sb were determined by the same protocol after As(V) and Sb(V) were reduced by thiourea, with As(V) and Sb(V) concentrations obtained by subtraction. Various experimental parameters affecting the on-line solid-phase extraction and determination of the analytes species have been investigated in detail. With 180 s preconcentration time, the enrichment factors were found to be 25.4 for As(III) and 24.6 for Sb(III), with the limits of detection (LODs) of 3.8 ng L{sup -1} for As(III) and 2.1 ng L{sup -1} for Sb(III). The precisions (RSD) for five replicate measurements of 0.5 {mu}g L{sup -1} of As(III) and 0.2 {mu}g L{sup -1} of Sb(III) were 4.2 and 4.8%, respectively. The developed method was validated by the analysis of standard reference materials (NIST SRM 1640a), and was applied to the speciation of inorganic As and Sb in natural water samples.

  14. Determination of trace germanium in health protection food by hydride generation atomic fluorescence spectrometry%氢化物-原子荧光光谱法测定保健食品中痕量锗

    Institute of Scientific and Technical Information of China (English)

    宋伟明; 倪刚; 胡奇林; 全晓塞

    2001-01-01

    A new method was introduced for the determination of trace germanium by hydride generation atomic fluorescence spectrometry(HGAFS).The effect of the medium amounts of acid, action of hydride and screening agent of the determination of germanium was investigated. The operating condition of the instrument was optimized. The interference from foreign ions was eliminated by adding phosphoric acid and tartaric acid. This method was applied to the determination of germanium in some health protection and nourishing food. The detection limit (3δ) is 6.2 ng/g with a RSD of 5% .The recovery of standard addition is in 95%~105%.%提出了以氢化物-原子荧光光谱法测定保健食品中锗的新方法,研究了酸介质、氢化物发生、增敏掩蔽剂等因素对测定的影响,并选择出仪器的最佳工作条件;采用磷酸-酒石酸介质进行测定,不但可有效消除共存离子的干扰,而且起到增敏作用,方法的检出限为6.2,ng/g,相对标准偏差(RSD)在5%以内,加标回收率为95%~105%,结果令人满意.

  15. X射线荧光光谱法测定不锈钢中17种元素%Determination of seventeen elements in stainless steel by X-ray fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    陈安源; 李辉; 马洪波; 黄金富

    2012-01-01

    采用X射线荧光光谱法分析不锈钢中的Al、Si、P、Ti、V、Cr、Mn、Co、Ni、W、Cu、Nb、Mo、As、Pb、Sn、Sb等17种元素.研究了仪器分析参数的设置,元素光谱背景的确定,光谱重叠和吸收-增强效应的校正.通过将理论Alpha系数法、基本参数法和经验系数法相结合的校正方法减小了曲线的品质因子K值,提高了检测数据的准确度.方法用于不锈钢标准物质中上述17种元素的测定,测定值与认定值相符,测定结果的相对标准偏差(RSD,n=11)在0.077%~7.6%之间.%Seventeen elements in stainless steel including Al, Si, P, Ti, V, Cr, Mn, Co, Ni, W, Cu, Nb, Mo, As, Pb, Sn and Sb were determined by X-ray fluorescence spectrometry (XRF). The setting of instrumental parameters, the ascertainment of element spectral background, the correction of spectral overlapping and absorption - enhancement effect were studied. The quality factor (K) of curve was reduced by combined correction methods of theoretical Alpha coefficient, basic parameter and empirical coefficient, resulting in improving accuracy of determination results. This method was applied to the determination of seventeen elements in reference materials of stainless steel. The found results were consistent with the certified values. The relative.standard deviations (RSD, n = ll) were 0.077 % - 7. 6 %.

  16. Preliminary results on the determination of ultratrace amounts of cadmium in tea samples using a flow injection on-line solid phase extraction separation and preconcentration technique to couple with a sequential injection hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Duan, Taicheng; Song, Xuejie; Jin, Dan; Li, Hongfei; Xu, Jingwei; Chen, Hangting

    2005-10-31

    In this work, a method was developed for determination of ultra-trace levels of Cd in tea samples by atomic fluorescence spectrometry (AFS). A flow injection solid phase extraction (FI-SPE) separation and preconcentration technique, to on-line couple with a sequential injection hydride generation (SI-HG) technique is employed in this study. Cd was preconcentrated on the SPE column, which was made from a neutral extractant named Cyanex 923, while other matrix ions or interfering ions were completely or mostly separated off. Conditions for the SPE separation and preconcentration, as well as conditions for the HG technique, were studied. Due to the separation of interfering elements, Cd hydride generation efficiency could be greatly enhanced with the sole presence of Co(2+) with a concentration of 200mugL(-1), which is much lower than those in other works previously reported. Interferences on both the Cd separation and preconcentration, and Cd hydride generation (HG) were investigated; it showed that both the separation and preconcentration system, and the HG system had a strong anti-interference ability. The SPE column could be repeatedly used at least 400 times, a R.S.D. of 0.97% was obtained for 6 measurements of Cd with 0.2mugL(-1) and a correlation coefficiency of 1.0000 was obtained for the measurement of a series of solutions with Cd concentrations from 0.1 to 2mugL(-1). The method has a low detection limit of 10.8ngL(-1) for a 25mL solution and was successfully validated by using two tea standard reference materials (GBW08513 and GBW07605).

  17. Analysis of Selenium in Blood of Patients with Lung Cancer by Microwave Digestion-Atomic Fluorescence Spectrometry%微波消解-原子荧光光谱法分析肺癌患者全血中硒

    Institute of Scientific and Technical Information of China (English)

    董琳; 张欣欣; 王继灵; 吴桂平; 杨庆斌

    2014-01-01

    目的:探讨肺癌患者血样中硒含量的变化。方法采集肺癌组和对照组血样,用硝酸、过氧化氢混合液微波消解样品,采用原子荧光光谱法测定血样中硒的含量。结果肺癌组和对照组硒平均质量浓度分别为0.087、0.123 mg/L。结论肺癌患者血样硒含量明显降低,缺硒可能是导致肺癌高发的重要因素。%Objective The paper investigates the change of the selenium content in the blood samples of patients with lung cancer .Methods The writer applies miscible liquids of nitric acid and hydrogen peroxide to the digestion of the collected blood samples from lung cancer group and the control group , using atomic fluorescence spectrometry to determine the content of selenium in blood samples .Results The average content of selenium in the lung cancer group and control group in average content of selenium are 0.087 mg/L and 0.123 mg/L respectively .Conclusion The content of selenium significantly lowered in the blood samples collected from patients with lung cancer .Selenium deficiency may be an important factor leading to high incidence of lung cancer .

  18. Optimize parameters of hydride generation-atomic fluorescence spectrometry for inorganic arsenic determination in grain%氢化物发生-原子荧光法测定粮食中无机砷条件的研究

    Institute of Scientific and Technical Information of China (English)

    杨庆惠

    2012-01-01

    应用氢化物发生—原子荧光分析技术进行粮食中无机砷测定的研究,通过优化酸度、硼氢化钾、载气流量、灯电流以及原子化器高度等分析条件,结果表明,砷浓度在0~30 ng/ml内呈线性关系,相关系数为0.999 9,相对标准偏差为1.6%,检出限为0.054 μg/L,用此方法测定粮食中无机砷,回收率为96.5%~103.5%.该方法简便、快速、灵敏,在实际样品测定中获得到了满意的结果,便于推广应用.%Hydride generation- atomic fluorescence spectrometry was adopted for determine the inorganic arsenic in grain. The experimental parameters such as Ph, KHB4 concentration, flow rate, lamp current and the height of atomizer were optimized. There is linear relation when the arsenic concentration was between 0~30 ng/ml with a correlation coefficient of 0. 999 9. The relative standard deviation was 1. 6%, and the detection limit was 0. 054μg/L. The recovery rate reached to 96. 5%~103. 5%. This method is simple,rapid and sensitive, and got satisfactory results in practicle,it is worth for generalize.

  19. Comparison of peptide nucleic acid fluorescence in situ hybridization assays with culture-based matrix-assisted laser desorption/ionization-time of flight mass spectrometry for the identification of bacteria and yeasts from blood cultures and cerebrospinal fluid cultures.

    Science.gov (United States)

    Calderaro, A; Martinelli, M; Motta, F; Larini, S; Arcangeletti, M C; Medici, M C; Chezzi, C; De Conto, F

    2014-08-01

    Peptide nucleic acid fluorescence in situ hybridization (PNA FISH) is a molecular diagnostic tool for the rapid detection of pathogens directly from liquid media. The aim of this study was to prospectively evaluate PNA FISH assays in comparison with culture-based matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) identification, as a reference method, for both blood and cerebrospinal fluid (CSF) cultures, during a 1-year investigation. On the basis of the Gram stain microscopy results, four different PNA FISH commercially available assays were used ('Staphylococcus aureus/CNS', 'Enterococcus faecalis/OE', 'GNR Traffic Light' and 'Yeasts Traffic Light' PNA FISH assays, AdvanDx). The four PNA FISH assays were applied to 956 positive blood cultures (921 for bacteria and 35 for yeasts) and 11 CSF cultures. Among the 921 blood samples positive for bacteria, PNA FISH gave concordant results with MALDI-TOF MS in 908/921 (98.64%) samples, showing an agreement of 99.4% in the case of monomicrobial infections. As regards yeasts, the PNA FISH assay showed a 100% agreement with the result obtained by MALDI-TOF MS. When PNA FISH assays were tested on the 11 CSF cultures, the results agreed with the reference method in all cases (100%). PNA FISH assays provided species identification at least one work-day before the MALDI-TOF MS culture-based identification. PNA FISH assays showed an excellent efficacy in the prompt identification of main pathogens, yielding a significant reduction in reporting time and leading to more appropriate patient management and therapy in cases of sepsis and severe infections.

  20. Recent Advances in Multidimensional Fluorescence Spectrometry.

    Science.gov (United States)

    1987-08-05

    certain advantages accrue from analysis of these data in a four- dimensional format. A final example in this category is the coupling of fluor - escence...44. Inasaka, T.; Ishibashi, K. and Ishibashi, N. Anal. Chia . Acta., 1982, 142, 1-12. ,% FIGURE CAPTIONS Fig. 1. Time resolved spectra of 2,6p-TNS

  1. Fiber optical asssembly for fluorescence spectrometry

    Science.gov (United States)

    Piltch, Martin S.; Gray, Perry Clayton; Rubenstein, Richard

    2015-08-18

    System is provided for detecting the presence of an analyte of interest in a sample, said system comprising an elongated, transparent container for a sample; an excitation source in optical communication with the sample, wherein radiation from the excitation source is directed along the length of the sample, and wherein the radiation induces a signal which is emitted from the sample; and, at least two linear arrays disposed about the sample holder, each linear array comprising a plurality of optical fibers having a first end and a second end, wherein the first ends of the fibers are disposed along the length of the container and in proximity thereto; the second ends of the fibers of each array are bundled together to form a single end port.

  2. Fluorescence spectroscopy

    DEFF Research Database (Denmark)

    Bagatolli, Luis

    2016-01-01

    Fluorescence spectroscopy is a powerful experimental tool used by scientists from many disciplines. During the last decades there have been important developments on distinct fluorescence methods, particularly those related to the study of biological phenomena. This chapter discusses...

  3. Determination of Arsenic and Mercury in Soil by Atomic Fluorescence Spectrometry with Aquafortis Bath Digestion%王水消解-原子荧光光谱法测定土中砷和汞

    Institute of Scientific and Technical Information of China (English)

    杜英秋

    2013-01-01

    To explore new methods of determinating arsenic and mercury in soil ,through atomic fluorescence spectrometry with aquafortis digestion ,arsenic and mercury in soil samples were determinated .The results showed that good linear relationship when concentrations of arsenic was 0~100 ng·mL-1 and mercury was 0~2 .0 ng·mL-1 ,the correlation coefficient were 0 .999 9 and 0 .999 3 respectively ,the detection limits were 0 .260 and 0 .022 ng·mL-1 ,the method was used for the determination of arsenic and mercury in different soil standard materials ,results were in the standard value range ,RSD was 1 .3% ~3 .5% ,that indicatd that the method had wide linear range ,good stability ,high sensitivity ,high accuracy and it could be widely used for the determina-tion of arsenic and mercury in bulk soil samples .%为探讨检测土壤中砷和汞的新方法,采用王水-水体系进行消解,应用原子荧光光谱法对土壤样品中的砷和汞进行测定。结果表明:当砷的质量浓度处于0~100.0 ng·mL-1,汞的质量浓度处于0~2.0 ng·mL-1时,浓度与荧光强度均能呈良好的线性关系,相关系数分别为0.9999和0.9993,方法的检出限分别为0.260和0.022 ng·mL-1,将该方法用于不同土壤标准物质的测定,测定结果均在标准值允许范围内,RSD处于1.3%~3.5%,说明该方法线性范围宽,稳定性好,灵敏度高,准确度高,可广泛用于批量土样中砷和汞的测定。

  4. High-performance liquid chromatography with fluorescence detection and ultra-performance liquid chromatography with electrospray tandem mass spectrometry method for the determination of indoleamine neurotransmitters and their metabolites in sea lamprey plasma.

    Science.gov (United States)

    Wang, Huiyong; Walaszczyk, Erin J; Li, Ke; Chung-Davidson, Yu-Wen; Li, Weiming

    2012-04-06

    We present a comparison of two sensitive methods, HPLC with fluorescence detector (HPLC/FLD) and UPLC with electrospray tandem mass spectrometry (UPLC/MS/MS), for the determination of indoleamine neurotransmitters (NTs) and their metabolites in sea lamprey plasma samples. Liquid-liquid extraction (LLE) and solid-phase extraction (SPE) were also tested for recovery and matrix effect. The recoveries of SPE determined by HPLC/FLD and UPLC/MS/MS ranged from 75 to 123% and 78 to 105%, respectively, while the recoveries of LLE ranged from 45 to 73% and 48 to 75%, respectively. SPE combined with HPLC/FLD and UPLC/MS/MS to determine the target analytes in plasma samples were validated of the sensitivity, reproducibility, accuracy and precision. Both methods exhibited excellent linearity in the range of 0.2-50 ng mL(-1) for all analytes. The limits of detection (LOD) varied from 0.04 ng mL(-1) to 0.13 ng mL(-1) for HPLC/FLD method and 0.003 ng mL(-1) to 0.02 ng mL(-1) for UPLC/MS/MS method. The inter-day accuracy ranged from 82.5 to 127.0% for HPLC/FLD and 93.0 to 113.0% for UPLC/MS/MS. The inter-day precision ranged from 9.9 to 32.3% for HPLC/FLD and 5.4 to 13.2% for UPLC/MS/MS. These results demonstrated that the values obtained by both methods were within the satisfactory range and the UPLC/MS/MS method provided more accurate and precise measurements than HPLC/FLD method. The comparison is of great importance to determine the available detectors, considering the complexity and expensiveness versus quality parameters. These two methods were applied to the analysis of four important indoleamine neurotransmitter analytes (5-hydroxytryptamine, 5-hydroxyindole-3-acetic acid, tryptamine and melatonin) in sea lamprey plasma samples.

  5. 氢化物发生-原子荧光光谱法测定Inconel 718合金中痕量硒%Determination of trace selenium in 718 alloy by hydride generation-atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    向祥蓉; 刘虹; 王佼

    2012-01-01

    本文采用氢化物发生-原子荧光光谱法测定Inconel718合金中痕量硒.对影响其测定的负高压、灯电流、载气流量、屏蔽气流量、载流酸类酸度、硼氢化钾等因素进行了较为详细的研究,优化了测定条件,考察了Inconel718合金主要组成元素和基体元素对硒测定的影响.结果表明,用氟化氨溶液络合,柠檬酸溶液作干扰抑制剂能基本消除基体元素和主要组成元素的干扰.硒浓度在0~100μg/L与荧光强度有良好的线性关系,方法的检出限为0.0083μg/L.对铁镍基高温合金标准样品和Inconel 718合金样品进行9次测定,相对标准偏差为1.6%~3.5%.%In this paper a simple and fast analytical procedure for the determination of selenium in Inconel 718 alloy by hydride generation atomic fluorescence spectrometry(HG-AFS) was developed. The in fluence of instrument parameters such as voltage of PMT, current of lamp, atomizer height, carrier gas rate,shield gas rate and concentration of HCI and KBH4 on the determination of selenium were studied, and the optimized conditions were obtained. Interference of coexistent elements and methods to eliminate the interference were investigated in detail. The results showed that ammonium fluoride and citric acid mo nohydrate were the best masking. Under the optimized conditions, the linear range of selenium is 0 ~ 100μg/L, and the detection limit is 0. 0083 μg/L. The relative standard deviation is 1. 6%~3. 5%(n=9) for the standard sample and the sample of Inconel 718 alloy.

  6. Determination of major and minor components in zinc concentrates by X-ray fluorescence spectrometry%X射线荧光光谱法测定锌精矿中主次量成分

    Institute of Scientific and Technical Information of China (English)

    唐梦奇; 黎香荣; 罗明贵; 阮贵武; 吕泽娥; 刘国文

    2012-01-01

    采用无水四硼酸锂熔剂熔融法制样,波长色散X射线荧光光谱法测定了锌精矿中的Zn、Pb、Fe、Cu、SiO2、As和Cd等7个主次量成分.采用低温硝酸锂预氧化处理,解决了锌精矿样品对铂黄金坩埚的腐蚀问题.以8个锌精矿标准样品建立校准曲线,用理论α系数法校正基体效应.测定锌精矿样品各成分的相对标准偏差(RSD,n=11)在0.20%~6.8%之间.用标准物质和实际样品验证,测定结果与标准物质认定值和实际样品化学方法测定值相符.%The samples were prepared by fusion method using anhydrous lithium tetraborate as flux. Seven components (including Zn. Pb, Fe, Cu, SiO2, As and Cd) in zinc concentrates were determined by wavelength dispersive X-ray fluorescence spectrometry. Low temperature preoxidation treatment was carried out with LiNO3,and thus the corrosion problem of platinum-gold alloy crucible was resolved. Calibration curve was established by eight zinc concentrates standard materials. The matrix effect was corrected by the theoretical alpha coefficients. The relative standard deviations (RSD, n= 11) of all the components determined in zinc concentrates were between 0. 20 % and 6. 8 %. The method has been applied to the determination of these components in standard materials and practical samples, and the analytical results were in good agreement with certified values of standard materials and values found of practical samples by chemical methods.

  7. Determination of Arsenic and Antimony in Leather by Atomic Fluorescence Spectrometry with Microwave Digestion%微波消解—原子荧光光谱法同时测定皮革中的砷和锑

    Institute of Scientific and Technical Information of China (English)

    吕小园; 陈新焕; 肖家勇; 刘正华; 陈练; 杨万彪; 黄红; 张志荣

    2012-01-01

    建立了皮革及其制品中砷和锑的微波消解-原子荧光光谱测定方法,方法准确、灵敏,快速.在优化的试验条件下,砷浓度在0.5~150 ng/mL范围内成线性关系,相关系数r=0.9995,检出限为0.22 ng/mL,回收率为99.4%~104.2%:锑浓度在0.5~ 120 ng/mL范围内成线性关系,相关系数r=0.9998,检出限为0.16 ng/mL,回收率为101.1%~106.7%.相对标准偏差(n=5)均小于5%.方法应用于皮革及其制品中砷和锑的测定,结果满意.%An accurate, sensitive and quick method for determination of arsenic and antimony in leather by atomic fluorescence spectrometry with microwave digestion was developed in this paper. Under the optimized condition, the result of arsenic showed that the linear range was 0.5 - 150 ng/mL(r =0. 9995), the limit of detection was 0. 22 ng/mL, and the average recoveries in leather ranged form 99. 4% to 104. 2% . The linear range of antimony was 0. 5 ~ 120 ng/mL( r = 0.9998) , the limit of detection was 0. 16 ng/mL, the average recoveries ranged form 101. 1% tol06.7%. TheRSD(n=5) were all lower than 5%. It has been applied to routine determination of arsenic and antimony in leather with satisfactory results.

  8. Application of analysis by spectrometry of X-fluorescence radiation. Determination of P-W-Zr in phospho tungstate, zirconium tungstate, zirconium phosphate, their mixtures, and their degradation products; Application de l'analyse par spectrometrie du rayonnement de fluorescence X. Dosage de P - W - Zr dans les phosphotungstate, tungstate de zirconium, phosphate de zirconium, leurs melanges et leurs produits de degradation

    Energy Technology Data Exchange (ETDEWEB)

    Guillon, A.; Lebrun, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    By chemical methods it is possible to dose accurately the constituents of solid samples containing essentially P, Zr and T. These methods involve prior separation of the elements, an operation which is relatively lengthy and delicate; they are furthermore ill-adapted for large series. In this case, the use of the X-fluorescence technique has many advantages. The process used is the borax-bead method. The fusion eliminates heterogeneity effects such as those dus to the size, the porosity and the composition of the grains, inter-elements effects, however, are not suppressed. These effects have been studied here and corrected for. (author) [French] Les methodes chimiques permettent le dosage precis des constituents d'echantillons solides contenant essentiellement P, Zr, W. Elles necessitent la separation prealable des elements, operation relativement longue et delicate, et se pretent mal a l'analyse de series importantes. dans ce cas, l'utilisation de la technique de fluorscence X ne presente que des avantages. La methode utilisee est celle des perles au borax. La fusion efface les effets d'heterogeneite telles que la taille, la porosite et la composition des grains. Les effets inter-elements, par contre, ne sont pas supprimes. Ce travail les met en evidence et permet leur correction. (auteur)

  9. 氢化物发生原子荧光光谱法测量化妆品中Sb的价态%Valent speciation analysis of antimony in cosmetics by hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    肖融; 张新智; 王昌钊; 冯礼; 秦德元; 刘霁欣

    2012-01-01

    考察了NaF、8-羟基喹啉、柠檬酸对Sb(Ⅲ)和Sb(V)原子荧光信号的掩蔽作用和还原解柠檬酸除掩蔽作用的方法.结果表明,0.10mol/L柠檬酸对Sb(V)掩蔽作用最强,且对Sb(Ⅲ)有增敏作用,最适于作为Sb价态测量的掩蔽剂,而10g/L碘化钾(KI)+ 10g/L硫脲(Tu)可在5h内完全解除柠檬酸对Sb(V)的掩蔽作用.据此建立了化妆品中Sb价态的非色谱氢化物发生原子荧光测量方法.样品经0.10mol/L柠檬酸提取两次后,离心去上清液,合并定容,得到提取液;提取液酸化后直接测得Sb(Ⅲ)含量;提取液酸化并加入KI+Tu,放置5h以上后可测得Sb(V)与Sb(Ⅲ)的含量和,此值减去Sb(Ⅲ)含量可得Sb(V)含量.计算表明,该方法对Sb(Ⅲ)和Sb(V)的检出限(3σ)均为0.32μg/L,定量限(3σ)均为1.0μg/L.对实际化妆品作了测量,Sb(Ⅲ)和Sb(V)的加标回收率在70%~130%之间.实验中存在少量Sb(Ⅲ)到Sb(V)的转化.%The masking effects of NaF, 8-hydroxygquinoline and citric acid on the atomic fluorescence signals of Sb(Ⅲ ) and Sb( V ) And the method for eliminating the masking effect of citric acid were investigated. The results show that 0. 10 mol/L citric acid has the strongest masking effect on Sb(V) and can increase the sensitivity of Sb(Ⅲ) , and l0g/L KI+l0g/L thiourea can completely eliminate the masking effect of citric acid in >5h. Based on this, a method for analyzing the valent speciation of Sb in cosmetics by hydride generation atomic fluorescence spectrometry (HGAFS) was developed. The samples were extracted twice with 0. L0ml/L citric acid. The supernatant was removed by centrifugation and the residues were merged asextract solution. After the acidification of the extract solution, the Sb(Ⅲ) content was determined directly. Then the extract solution was added with KI (10g/L)+ thiourea (l0g/L) and set aside for >5h before the total content of Sb(V) and Sb(Ⅲ) was determined. The Sb( V) content was obtained by subtracting Sb

  10. 氢化物原子荧光光谱法同时测定生活饮用水中砷和硒%Simulatneous Determination of Arsenic and selenium in Drinking Water Samples by Hydride Generation Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    张祥楼

    2014-01-01

    建立了氢化物发生原子荧光光谱法同时测定生活饮用水中砷和硒的方法.测试结果表明砷和硒在质量浓度分别为0.00μg/L~10.00μg/L和0.00μg/L~40.00μg/L范围内呈线性关系,相关系数分别为(砷r=0.9998,硒r=0.9997)。仪器检出限为砷:0.03μg/L硒:0.05μg/L。本方法检出限砷为0.075μg/L;硒为0.125μg/L。水质样品中砷的回收率为92.6%~96.5%,精密度为0.8%~1.4%;硒的回收率为91.2%~97.4%,精密度为1.0%~1.6%。应用本方法测定生活饮用水中的砷和硒方法简便、快速,结果准确可靠,较好地提高了工作效率。%A method for simulatneous determination of Arsenic and selenium in drinking water samples by hydride generation atomic fluorescence spectrometry.As a matter of fact ,the linear range of Arsenic was 0.00μg/L~10.00μg/L and the related coefficient was 0.9998;While the linear range of Selenium was 0.00μg/L~40.00μg/L and the related coefficient was0.9997. Instrument detection limit was 0.03μg/L(arsenic)and 0.05μg/L(selenium).Detection limits of the method was 0.075μg/L (arsenic)and 0.125μg/L(selenium). The rate of arsenic recovery was 92.6%~96.5%and the precision in the drinking water was in the range of 0.8%~1.4%.while the rate of selenium recovery was 92.6%~96.5%and the precision in the drinking water was in the range of 1.0%~1.6%.The experimental results shows that the method is applicable .

  11. Determination of Microelement in Milk Powder by X-Ray Fluorescence Spectrometry%X射线荧光光谱法测定乳粉中的微量元素

    Institute of Scientific and Technical Information of China (English)

    王谦; 许小丽; 房科腾

    2015-01-01

    采用粉末压片制样波长色散X射线荧光光谱法测定乳粉中的氮、钠、镁、磷、氯、钾、钙。从仪器的X射线光管铍窗厚度、电流大小、测量时间和样品制样压力等方面研究了氮元素的测定。选择不同种类的乳粉,由标准方法定值,然后与标样一起建立校准曲线,校准曲线采用理论α影响系数法校正基体效应。研究发现铍窗厚度是制约氮元素测定的主要因素;样品均质处理必须用手工研磨的方法;X射线可以造成乳粉损伤,随着时间增加,测量结果呈线性增加趋势。结果与标准方法比对,两者相符,氮元素的检出限和精密度RSD(n=9)分别为0.09%和2.9%,其他元素的检出限和精密度RSD(n=9)分别都小于0.001%和3%。%A method has been developed for the determination of N,Na,Mg,P,Cl,K,Ca in milk powder by wavelength dispersive X-ray fluorescence spectrometry method with pressed powder pellets. From the X-ray tube Beryllium window thickness and the current intensity of instrument,measurement times,and sample preparation etc. research for the determination of nitrogen. Milk powder reference materials are scarce,so the different kinds of milk powder samples were chosen and determined firstly by classical methods,then calibration curves were drawn using both the milk powder samples with known contents and reference materials. To eliminate the effect,the variable theoreticalαinfluence coefficient method was used to correct matrix effects. The study found homogenized sample must be hand-grinding method. Thickness of beryllium window is the main factor restricting the nitrogen determination. X-ray irradiation can cause the destruction of milk powder,its multiple interference can make the content of elements according to certain rule changes. The method has been applied to the determination of these elements in milk powder and the results are in agreement with standard methods. For nitrogen

  12. Novel “turn on” fluorescent sensors based on anthracene and carbazone units for Cu (II) ion in CH{sub 3}CN–H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Erdemir, Serkan, E-mail: serdemir82@gmail.com; Malkondu, Sait

    2015-02-15

    Two novel anthracene-based receptors containing Schiff base and urea groups (AOC and ATC) were synthesized in one step and full characterized. The optical properties of receptors AOC and ATC towards metal ions were investigated by UV–visible and fluorescence spectroscopy. It was found that both receptors AOC and ATC show highly selectivity towards Cu{sup 2+} over other 17 metal ions in CH{sub 3}CN–H{sub 2}O (9/1, v/v). - Highlights: • Novel fluorescent sensors based on anthracene and carbazide AOC and ATC were synthesized. • The optical properties of AOC and ATC were observed by UV–visible and fluorescence spectroscopy. • AOC and ATC showed highly selective and sensitive to Cu{sup 2+} over other 17 metal ions.

  13. 高效液相色谱氢化物发生原子荧光光谱联用检测海藻中砷形态%Determination of arsenic speciation in seaweeds using high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation-atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    高鹭; 董伟峰; 彭心婷; 史立娟; 李妍; 庞艳华; 徐静; 曹际娟

    2015-01-01

    目的:测定14种海藻样品中总砷和无机砷的含量,同时分析样品中6种砷形态。方法将海藻样品经过微波消解的前处理方法,通过电感耦合等离子体质谱(inductively coupled plasma mass spectrometry, ICP-MS)测定总砷含量;根据国标方法中无机砷检测的前处理方法,通过原子荧光光谱(atomic fluorescence spectrometry, AFS)测定无机砷含量;最后通过酸提的前处理方法,利用高效液相色谱-氢化物发生-原子荧光光谱法(high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation-atomic fluorescence spectrometry, HPLC-(UV)-HG-AFS)测定海藻样品中6种形态砷含量并与国标无机砷方法比较。结果14种海藻样品中总砷含量为0.038~46.2 mg/kg;无机砷含量为0.006~19.3 mg/kg;对HPLC-(UV)-HG-AFS仪器的优化和方法的摸索后,从海藻样品中主要测得的砷形态为As(III)、As(V)和DMA, MMA含量较少,没有测出AsB和 AsC。结论在砷形态较为复杂的海藻样品检测中,通过 HPLC-(UV)-HG-AFS 检测方法可以有效避免无机砷前处理中可能出现的有机砷向无机砷转变的现象,降低干扰,增加测试的准确性,更为具体地表现海藻样品中主要的砷形态含量。%Objective The content of total arsenic and inorganic arsenic were determined in 14 seaweeds and 6 kinds of arsenic species were determined at the same time. Methods The content of total arsenic was determined by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. According to the pretreatment method of national standard method, the content of inorganic arsenic was determined by atomic fluorescence spectrometry (AFS). The results of 6 arsenic species were studied by high performance liquid chromatography-ultraviolet photo-oxidation-hydride generation-atomic fluorescence spectrometry (HPLC-(UV)-HG-AFS) after acid extraction, which were compared with the national standard method. Results In 14

  14. 液相色谱-串联质谱法分析爆米花桶水浸泡液中的荧光增白剂%Analysis of Fluorescent Substance Migration of Popcorn Cup by Liquid Chromatography-tandem Mass Spectrometry Method

    Institute of Scientific and Technical Information of China (English)

    刘峻; 李军; 李建中; 秦紫明

    2013-01-01

    使用液相色谱-串联质谱(LC-MS)的方法测试了市面的爆米花桶中荧光增白剂的种类和含量,实验选用VBL、APC、SPP、APH 4种荧光增白剂作为目标化合物,在信噪比为10(S/N=10)的条件下,4种荧光增白剂的检出限均小于10 ng/mL,相对标准偏差(RSD) <10%.实验初步表明,本次上海地区含荧光增白剂的爆米花桶中添加的荧光增白剂均为APC,可迁移量从0.653 mg/kg到23.166 mg/kg不等.该方法可以有效分离荧光增白剂,并对其进行定性定量判定.%This experiment use liquid chromatography-tandem mass spectrometry (LC-MS) to test the type and content of the fluorescent substance in the popcorn cups in the market. VBL, APC, SPP, APH four fluorescent brighteners were identified as the target compound. 10 times of the signal-to-noise ratio was used to confirm the detection limit, and all fluorescent brighteners' limits were less than 10 ng /mL, the method precision (RSD) was < 10%. It proved that the fluorescent substances added in the examined popcorn cups were APC. The migration amounts ranged from 0.653 mg/kg to 23.166 mg/kg. The method can effectively separate the fluorescent substance and further be defined qualitatively and quantitatively.

  15. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained r...

  16. Formation of fluorescent polydopamine dots from hydroxyl radical-induced degradation of polydopamine nanoparticles.

    Science.gov (United States)

    Lin, Jia-Hui; Yu, Cheng-Ju; Yang, Ya-Chun; Tseng, Wei-Lung

    2015-06-21

    This study describes the synthesis of fluorescent polydopamine dots (PDs) through hydroxyl radical-induced degradation of polydopamine nanoparticles. The decomposition of polydopamine nanoparticles to fluorescent PDs was confirmed using transmission electron microscopy and dark-field microscopy. The analysis of PDs by using laser desorption/ionization time-of-flight mass spectrometry revealed that the PDs consisted of dopamine, 5,6-dihydroxyindole, and trihydroxyindole units. Oligomerization and self-assembly of these units produced a broad adsorption band, resulting in an excitation-wavelength-dependent emission behavior. The maximal fluorescence of PDs appeared at 440 nm with a quantum yield of 1.2%. The coordination between the catechol groups of PDs and ferric ions (Fe(3+)) quenched the fluorescence of PDs; the limit of detection at a signal-to-noise ratio of 3 for Fe(3+) was determined to be 0.3 μM. The presence of pyrophosphate switched on the fluorescence of the PD-Fe(3+) complexes. Compared to the other reported methods for sensing Fe(3+), PDs provided simple, low-cost, and reusable detection of Fe(3+).

  17. A fluorescence scanning electron microscope

    Directory of Open Access Journals (Sweden)

    Takaaki Kanemaru

    2010-01-01

    Full Text Available Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM and an electron microscope (EM. In the current study, a scanning electron microscope (SEM (JEOL JXA8600 M was combined with a fluorescence digital camera microscope unit and this hybrid instrument was named a fluorescence SEM (FL-SEM. In the labeling of FL-SEM samples, both Fluolid, which is an organic EL dye, and Alexa Fluor, were employed. We successfully demonstrated that the FL-SEM is a simple and practical tool for correlative fluorescence and electron microscopy.

  18. Highly photostable zinc selective molecular marker bearing flexible pivotal unit: opto-fluorescence enhancement effect and imaging applications in living systems.

    Science.gov (United States)

    Sinha, Sougata; Gaur, Pankaj; Dev, Sagarika; Mukherjee, Trinetra; Mathew, Jomon; Mukhopadhyay, Subhrakanti; Ghosh, Subrata

    2015-05-28

    Novel molecular probes for imaging zinc in biological systems are gaining interest as they help in understanding the role of zinc in regulating various bio-events. In this regard, a new C2-symmetric molecular system has been developed and successfully applied as light-up material for signaling divalent zinc with green emission. The fluorescence enhancement was highly zinc specific and this newly developed probe bears a submicromolar detection capability. While probe and the ensemble -Zn(2+) exhibited remarkably high photostability, light-triggered fluorescence enhancement was observed in the case of -Zn(2+). The nature of the -Zn(2+) complex and the associated spectral shift are further supported by theoretical calculations. As the present probe absorbs in the visible region and emits in the green, it was preferred as a potential material for imaging zinc in biological systems including animal and plant cells such as pollen grains and fish egg cells. Such fluorescence imaging of zinc revealed the efficacy of the probe in detection and localization of zinc in various biological systems.

  19. Determination of 22 Elements in Herb Tea by X-Ray Fluorescence Spectrometry%X射线荧光光谱法测定花草茶中22种元素

    Institute of Scientific and Technical Information of China (English)

    李丹; 葛良全; 王广西; 赖万昌; 翟娟; 陈露

    2015-01-01

    采用粉末压片法制样,应用X射线荧光光谱法对花草茶中N ,Na ,Mg ,Al ,Si ,P ,S ,Cl ,K ,Ca , Ti ,Cr ,Mn ,Fe ,Ni ,Cu ,Zn ,Br ,Rb ,Sr ,Ba ,Pb共22种元素进行了分析。讨论了测量条件的选择,对于22种目标元素的分析线,除Ba ,Pb采用L线外,其余都选择Kα线,在对Rh靶Kα线的康普顿散射进行测量时,应适当降低管电压,选择合适的管电流。采用经验系数法和3条散射谱线(Rh靶Lα线的瑞利散射、0.1876nm处的散射线、Rh靶Kα线的康普顿散射)作内标进行基体效应校正,并对 N ,Na ,Ca ,Ti ,Mn , Sr ,Ba等部分元素进行了谱线重叠干扰校正。实验结果表明,该方法对N ,Na ,Mg ,Al ,Si ,P ,S ,Cl ,K , Ca ,Ti ,Cr ,Mn ,Fe ,Ni ,Cu ,Zn ,Br ,Rb ,Sr ,Ba ,Pb各目标元素的检出限较低,且准确度较好,精密度较高。采用该方法对花草茶中元素的种类和含量信息进行分析发现,花草茶元素组成较为丰富,不同种类花草茶元素种类和含量有差异,且同一种类不同来源花草茶略有差异,但元素组成含量特征大体相似。综上可知,该方法操作简单,能够实现花草茶的低成本、快速、准确、多元素测定。%N ,Na ,Mg ,Al ,Si ,P ,S ,Cl ,K ,Ca ,Ti ,Cr ,Mn ,Fe ,Ni ,Cu ,Zn ,Br ,Rb ,Sr ,Ba and Pb in herb tea were deter‐mined by X‐ray fluorescence spectrometry with pressed powder pellets .The measuring conditions of target elements were inves‐tigated ,including how to select its analytical line .In addition to Ba and Pb using L line ,Kα line was selected for the rest .When the Compton scattered radiation of Rh Kα was measured ,The X‐ray tube voltage should be appropriately reduced ,and the appro‐priate tube current should be selected .The matrix effect was corrected by empirical coefficient method and using scattered radia‐tion (the Rayleigh scattered

  20. Integrated sampling and analysis unit for the determination of sexual pheromones in environmental air using fabric phase sorptive extraction and headspace-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Alcudia-León, M Carmen; Lucena, Rafael; Cárdenas, Soledad; Valcárcel, Miguel; Kabir, Abuzar; Furton, Kenneth G

    2017-03-10

    This article presents a novel unit that integrates for the first time air sampling and preconcentration based on the use of fabric phase sorptive extraction principles. The determination of Tuta absoluta sexual pheromone traces in environmental air has been selected as analytical problem. For this aim, a novel laboratory-built unit made up of commercial brass elements as holder of the sol-gel coated fabric extracting phase has been designed and optimized. The performance of the integrated unit was evaluated analyzing environmental air sampled in tomato crops. The unit can work under sampling and analysis mode which eliminates any need for sorptive phase manipulation prior to instrumental analysis. In the sampling mode, the unit can be connected to a sampling pump to pass the air through the sorptive phase at a controlled flow-rate. In the analysis mode, it is placed in the gas chromatograph autosampler without any instrumental modification. It also diminishes the risk of cross contamination between sampling and analysis. The performance of the new unit has been evaluated using the main components of the sexual pheromone of Tuta absoluta [(3E,8Z,11Z)-tetradecatrien-1-yl acetate and (3E,8Z)-tetradecadien-1-yl acetate] as model analytes. The limits of detection for both compounds resulted to be 1.6μg and 0.8μg, respectively, while the precision (expressed as relative standard deviation) was better than 3.7%. Finally, the unit has been deployed in the field to analyze a number of real life samples, some of them were found positive. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Saiz-Jimenez, C.; Gonzalez-Vila, F.J.

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  2. Characterization of chemical elements in soil submitted to different systems use and management by energy dispersive x-ray fluorescence spectrometry (EDXRF); Caracterizacao dos niveis de elementos quimicos em solo, submetido a diferentes sistemasde uso e manejo, utilizando espectrometria de fluorescencia de raios-X por energia dispersiva (EDXRF)

    Energy Technology Data Exchange (ETDEWEB)

    Wastowski, Arci Dirceu; Rosa, Genesio Mario da; Cherubin, Mauricio Roberto; Rigon, Joao Paulo Gonsiorkiewicz, E-mail: wastowski@smail.ufsm.b [Universidade Federal de Santa Maria (UFSM), Frederico Westphalen, RS (Brazil). Centro de Educacao Superior Norte do Rio Grande do Sul

    2010-07-01

    This study aimed to evaluate the chemical elements levels in soil, submitted to different management systems and use by the Energy Dispersive X-Ray Fluorescence Spectrometry - EDXRF. The systems were T1 - agroforestry (SAF), T2 - native field (CN), T3 - native forest (NM), T4 - tillage forest (PF); T5 - conventional tillage system (SPC) and T6 - system tillage (NT). Samples were collected at 0-10 and 10-20 cm, dried and ground for analysis in EDX-720. The soil showed no difference in the average concentrations of chemical elements analyzed in the profiles, but the systems presented different concentrations of metal elements, and T3 had the highest K, Ca and Zn at 0-10 cm and higher contents of K, Ca, Cu, Zn and Mn in the layer of 10-20 cm. (author)

  3. X-ray spectrometry with synchrotron radiation; Roentgenspektrometrie mit Synchrotronstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Matthias [Physikalisch-Technische Bundesanstalt (PTB), Berlin (Germany). Arbeitsgruppe ' Roentgen- und IR-Spektrometrie' ; Gerlach, Martin; Holfelder, Ina; Hoenicke, Philipp; Lubeck, Janin; Nutsch, Andreas; Pollakowski, Beatrix; Streeck, Cornelia; Unterumsberger, Rainer; Weser, Jan; Beckhoff, Burkhard

    2014-12-15

    The X-ray spectrometry of the PTB at the BESSY II storage ring with radiation in the range from 78 eV to 10.5 keV is described. After a description of the instrumentation development reference-sample free X-ray fluorescence analysis, the determination of fundamental atomic parameters, X-ray fluorescence analysis under glance-angle incidence, highly-resolving absorption spectrometry, and emission spectrometry are considered. Finally liquid cells and in-situ measurement techniques are described. (HSI)

  4. Proteome analysis of round-headed and normal spermatozoa by 2-D fluorescence difference gel electrophoresis and mass spectrometry%以荧光差异凝胶双向电泳和质谱技术对圆头精子和正常精子的蛋白质组学分析

    Institute of Scientific and Technical Information of China (English)

    Ting-Ting Liao; Zhen Xiang; Wen-Bing Zhu; Li-Qing Fan

    2009-01-01

    Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round-headed and normal spermatozoa. Two-dimensional (2-D) fluorescence difference gel electrophoresis (DIGE) coupled with mass spectrometry (MS) was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry (MS/MS) exhibited significant changes (paired t-test, P < 0.05) in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.

  5. Fluorescent microspheres

    Science.gov (United States)

    Rembaum, A.

    1978-01-01

    Latex particles with attached antibodies have potential biochemical and environmental applications. Human red blood cells and lymphocytes have been labeled with fluorescent microspheres by either direct or indirect immunological technique. Immunolatex spheres can also be used for detecting and localizing specific cell surface receptors. Hormones and toxins may also be bondable.

  6. Study on determination of lead in aluminium polychlorid by continuous flow-hydride generation atomic fluorescence spectrometry%连续流动-氢化物发生原子荧光光谱法测定聚合氯化铝中铅

    Institute of Scientific and Technical Information of China (English)

    龚胜芳; 高树林; 李志华; 王红柳

    2014-01-01

    采用连续流动-氢化物发生原子荧光光谱法(CF-HGAFS)测定聚合氯化铝中的铅,优化了实验条件,在最佳实验条件下,铅的荧光强度在0~25μg /L范围内与浓度呈良好的线性关系,方法检出限为0.043μg/L ,方法回收率在95.3%~105.6%之间,本法操作简便、快捷,而且具有很好的准确性和精密度,应用前景良好。%A method for the determination of lead in aluminium polychlorid by continuous flow-hydride generation atomic fluorescence spectrometry was established .The effect of experimental conditions on the atomic fluorescence intensity were investigated and optimized .In this condition ,the calibration curve was linear up to 25μg/L ,the detection limit was 0 .043μg/L ,and the recovery was in range of 95 .3%-105.6% . The method is not only simple and rapid but also precise and accurate ,and shows good application pros-pects .

  7. Binding of several benzodiazepines to bovine serum albumin: Fluorescence study

    Science.gov (United States)

    Machicote, Roberta G.; Pacheco, María E.; Bruzzone, Liliana

    2010-10-01

    The interactions of lorazepam, oxazepam and bromazepam with bovine serum albumin (BSA) were studied by fluorescence spectrometry. The Stern-Volmer quenching constants and corresponding thermodynamic parameters Δ H, Δ G and Δ S were calculated. The binding constants and the number of binding sites were also investigated. The distances between the donor (BSA) and the acceptors (benzodiazepines) were obtained according to fluorescence resonance energy transfer and conformational changes of BSA were observed from synchronous fluorescence spectra.

  8. Quantification of β-carotene, retinol, retinyl acetate and retinyl palmitate in enriched fruit juices using dispersive liquid-liquid microextraction coupled to liquid chromatography with fluorescence detection and atmospheric pressure chemical ionization-mass spectrometry.

    Science.gov (United States)

    Viñas, Pilar; Bravo-Bravo, María; López-García, Ignacio; Hernández-Córdoba, Manuel

    2013-02-01

    A detailed optimization of dispersive liquid-liquid microextraction (DLLME) was carried out for developing liquid chromatographic (HPLC) techniques, using both fluorescence and atmospheric pressure chemical ionization mass spectrometric (APCI-MS) detection, for the simultaneous analysis of preforms of vitamin A: retinol (R), retinyl acetate (RA), retinyl palmitate (RP) and β-carotene (β-C). The HPLC analyses were carried out using a mobile phase composed of methanol and water, with gradient elution. The APCI-MS and fluorescence spectra permitted the correct identification of compounds in the analyzed samples. Parameters affecting DLLME were optimized using 2 mL of methanol (disperser solvent) containing 150 μL carbon tetrachloride (extraction solvent). The precision ranged from 6% to 8% (RSD) and the limits of detection were between 0.03 and 1.4 ng mL(-1), depending on the compound. The enrichment factor values were in the 21-44 range. Juice samples were analyzed without saponification and no matrix effect was found when using fluorescence detection, so calibration was possible with aqueous standards. However, a matrix effect appeared with APCI-MS, in which case it was necessary to apply matrix-matched calibration. There was great variability in the forms of vitamin A present in the juices, the most abundant ester being retinyl acetate (0.04 to 3.4 μg mL(-1)), followed by the amount of retinol (0.01 to 0.16 μg mL(-1)), while retinyl palmitate was not detected, except in the milk-containing juice, in which RP was the main form. The representative carotenoid β-carotene was present in the orange, peach, mango and multifruit juices in high amounts. The method was validated using two certified reference materials.

  9. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  10. New fluorescence parameters for monitoring photosynthesis in plants

    NARCIS (Netherlands)

    Force, L.; Critchley, Ch.; Rensen, van J.J.S.

    2003-01-01

    Chlorophyll fluorescence measurements have a wide range of applications from basic understanding of photosynthesis functioning to plant environmental stress responses and direct assessments of plant health. The measured signal is the fluorescence intensity (expressed in relative units) and the most

  11. Determination of 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and -furans at the part per trillion level in United States beef fat using high-resolution gas chromatography/high-resolution mass spectrometry

    Science.gov (United States)

    Ferrario, J.; Byrne, C.; McDaniel, D.; Dupuy, A. Jr; Harless, R.

    1996-01-01

    As part of the U.S. EPA Dioxin Reassessment Program, the 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and furans were measured at part per trillion (ppt) levels in beef fat collected from slaughter facilities in the United States. This is the first statistically designed national survey of these compounds in the U.S. beef supply. Analyte concentrations were determined by high-resolution gas chromatography/high-resolution mass spectrometry, using isotope dilution methodology. Method limits of detection on a whole weight basis were 0.05 ppt for TCDD and 0.10 ppt for TCDF, 0.50 ppt for the pentas (PeCDDs/PeCDFs)/hexas (HxCDDs/HxCDFs)/heptas (HpCDDs/HpCDFs), and 3.00 ppt for the octas (OCDD/OCDF). Method detection and quantitation limits were established on the basis of demonstrated performance criteria utilizing fortified samples rather than by conventional signal-to-noise or variability of response methods. The background subtraction procedures developed for this study minimized the likelihood of false positives and increased the confidence associated with reported values near the detection limits. Mean and median values for each of the 2,3,7,8-Cl-substituted dioxins and furans are reported, along with the supporting information required for their interpretation. The mean toxic equivalence values for the samples are 0.35 ppt (nondetects = 0) and 0.89 ppt (nondetects = 1/2 LOD).

  12. 原子荧光光谱法测定四方金矿生活饮用水中砷含量%Determination of arsenic in drinking water Quartet Gold Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    贾书朝; 冯美云

    2014-01-01

    Arsenic is toxic to humans and other organisms carcinogenic effects, due to the toxicity of arsenic large, so the detection of arsenic in water is necessary. Through AFS-230E atomic fluorescence spectrophotometer for determination of arsenic in drinking water to ensure that our guarantee water security.%砷是对人体及其他生物体有毒害作用的致癌物质,由于砷的毒性很大,因此对水质中砷的检测是必要的。本文通过AFS-230E原子荧光分光光度仪对饮用水中砷含量测定,确保我们的保证用水安全。

  13. 9-fluorenylmethyl chloroformate as a fluorescence-labeling reagent for derivatization of carboxylic acid moiety of sodium valproate using liquid chromatography/tandem mass spectrometry for binding characterization: a human pharmacokinetic study.

    Science.gov (United States)

    Mohammadi, Bahareh; Majnooni, Mohammad Bagher; Khatabi, Pyman Malek; Jalili, Ronak; Bahrami, Gholamreza

    2012-01-01

    In High Performance Liquid Chromatographic (HPLC) determination of chemicals with acidic functions, different labeling agents are used to improve sensitivity of the assay. 9-Fluorenylmethyl chloroformate (FMOC-Cl), on the other hand, is a suitable labeling agent, which reacts with both primary and secondary amines and less readily with hydroxyl groups in alkaline conditions. However, the reagent has not been applied in labeling of chemicals with acidic function yet. In this study which is the first report on application of FMOC-Cl in derivatization and analysis of a drug with acidic function, valproic acid (VPA), one of a series of fatty carboxylic acids with anticonvulsant activity, was derivatized using the reagent and quantified in serum samples by HPLC with fluorescence detection. In addition, to document the reaction between the labeling agent and carboxylic acid moiety of the drug, we developed a liquid chromatography-tandem MS/MS (LC-MS/MS) method. Following liquid-liquid extraction, derivatization of the drug and an internal standard was achieved in alkaline medium. The elute was monitored by a fluorescence detector with respective excitation and emission wavelengths of 265 and 315 nm. The present method is more sensitive comparing with other published HPLC procedures for analysis of VPA. The assay is sensitive enough to measure drug levels obtained in human single dose studies with a limit of quantification of 0.01 μg/mL. Also the method is linear over the concentrations range of 0.01-32 μg/mL of VPA in human serum using 100 μL serum sample and 5 μL injection. The coefficient variation values of both inter and intra day analysis were less than 12% and the percentage error was less than 4%. The method performance was studied and the validated procedure applied in a randomized cross-over bioequivalence study of two different VPA preparations in 24 healthy volunteers.

  14. 氢化物原子荧光光谱法同时测定血液透析用水中的砷和锑%Simultaneous determination of arsenic and antimony in blood dialysis water by hydride atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    汪洋; 邵丽华; 魏滨; 何漪

    2011-01-01

    Objective:To establish a method for the simultaneous determination of arsenic and antimony in blood dialysis water by hydride atomic fluorescence spectrometry. Methods: The working condition of the determination were studied and optimized for the simultaneous determination of arsenic and antimony in blood dialysis water by hydride atomic fluorescence spectrometry.Results: The detection limits of this method were found to be 0.40 μg/L for arsenic and 0.50 μg/L for antimony, and the RSD were in the range of 2.2% ~ 4.2% for arsenic and 3.2% ~ 5.3% for antimony. The recovery tates of standard spiking for arsenic and antimony were in the range of 94.0% ~ 101.2% and 98.9% ~ 103.6%, respectively. Conclusion: The method is sensitive, accurate and rapid. It can be adopted for simultaneous determination of arsenic and antimony in blood dialysis water.%目的:建立一种氢化物原子荧光光谱法同时测定血液透析用水中的砷和锑的方法.方法:优化测定条件,采用氢化物原子荧光光谱法同时测定血液透析用水中的砷和锑.结果:砷和锑的检出限、相对标准偏差、回收率分别为:0.40μg/L和0.50 μg/L;2.2%~4.2%和3.2%~5.3%;94.0%~101.2%和98.9%~103.6%.结论:本方法灵敏度高,准确、快捷,能同时测定血液透析用水中的砷和锑,省时、省力.

  15. Bridging fluorescence microscopy and electron microscopy

    NARCIS (Netherlands)

    Giepmans, Ben N. G.

    Development of new fluorescent probes and fluorescence microscopes has led to new ways to study cell biology. With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community. A major

  16. Bridging fluorescence microscopy and electron microscopy

    NARCIS (Netherlands)

    Giepmans, Ben N. G.

    2008-01-01

    Development of new fluorescent probes and fluorescence microscopes has led to new ways to study cell biology. With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community. A major breakth

  17. Infrared spectra of U.S. automobile original finishes (post - 1989). VIII: In situ identification of bismuth vanadate using extended range FT-IR spectroscopy, Raman spectroscopy, and X-ray fluorescence spectrometry.

    Science.gov (United States)

    Suzuki, Edward M

    2014-03-01

    Chrome Yellow (PbCrO4 ·xPbSO4 ) was a common pigment in U.S. automobile OEM finishes for more than three decades, but in the early 1990s its use was discontinued. One of its main replacements was Bismuth Vanadate (BiVO4 ·nBi2 MoO6 , n = 0-2), which was commercially introduced in 1985, as this inorganic pigment also produces a very bright hue and has excellent outdoor durability. This paper describes the in situ identification of Bismuth Vanadate in automotive finishes using FT-IR and dispersive Raman spectroscopy and XRF spectrometry. Some differentiation of commercial formulations of this pigment is possible based on far-infrared absorptions, Raman data, and elemental analysis. The spectral differences arise from the presence or absence of molybdenum, the use of two crystal polymorphs of BiVO4 , and differences in pigment stabilizers. Bismuth Vanadate is usually not used alone, and it is typically found with Isoindoline Yellow, hydrous ferric oxide, rutile, Isoindolinone Yellow 3R, or various combinations of these.

  18. 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.

  19. Determination of thirteen components in cast iron by X-ray fluorescence spectrometry with power press method%X射线荧光光谱粉末压片法检测合金铸铁中13种成分

    Institute of Scientific and Technical Information of China (English)

    武映梅; 石仕平; 宋武元

    2012-01-01

    本文介绍了粉末压片制样-X射线荧光光谱法对合金铸铁中Si、P、Cu、S、Mn、As、Ti、Sn、V、Cr、Ni、Mo和Al的分析.采用样品低温退火的方式进行样品前处理,并在样品成型过程中于黏结剂层中滴加10d按一定比例配制的松香与丙酮的混合溶液进行样品制备.选用15个国家级、部级标准物质及自制标准物质配制成标准系列绘制校准工作曲线;运用空白试样系数校正法对V、Cr、Mn等各元素的谱线重叠进行校正,同时将理论α系数与经验系数相结合,有效的克服了铸铁中各元素谱线干扰与基体效应.本法测定结果与电感耦合等离子体发射光谱及火花发射光谱法分析结果一致.%This paper reported the method for the determination of Si, P, Cu, S, Mn, As, Ti, Sn, V, Cr, Ni, Mo and Al in cast iron by X-ray fluorescence (XRF) spectrometry with power pressed method. The sample was pretreated with low-temperature annealing method, and during the sample-molding process, ten drops of mixed solution with certain ratio of rosin and acetone in the adhesive layer. The method selected fifteen national/ministerial grade and self-made standard samples to prepare a standard series of sample for establishing the calibration curve. The blank sample coefficient correction method was employed for calibrating the interference resulted from the overlaps of spectrum lines. Theoretical alpha coefficient and empirical coefficient was combined to overcome the sample spectral interference and matrix effect. The results of the proposed method were consistent with those of inductively coupled plasma spectrometry and spark source optical emission spectrometry.

  20. X 射线荧光光谱法测定汽油中的氯含量%DETERMINATION OF CHLORINE CONTENT IN GASOLINE BY X-RAY FLUORESCENCE SPECTROMETRY

    Institute of Scientific and Technical Information of China (English)

    顾海波; 张大华; 雷秦睿; 谢燕红

    2015-01-01

    A method for determining chlorine content in gasoline by X-ray fluorescence analysis is introduced. At the best conditions of 25 kV and 1.0 mA,the chloride concentration in the range of 10—1 000 μg∕g is linear with the fluorescence intensity. The influence of different substrates (mixture of pe-troleum ether and toluene (a volume ratio of 6∶4),isooctane and commercially available chlorine stand-ard sample)on the results of determination is studied,and their standard curves were established, respectively. It is found that the isooctane is the best substrate for the method. Precision and repeat-ability of the method were investigated. The effect of different gasoline and samples with different chlo-rine forms was invested. The results show that the recovery rate is between 95% and 105%,and the relative standard deviation is less than 4.2%.%介绍了一种利用 X 射线荧光光谱法测定汽油中氯含量的方法。在管电压为25 kV、管电流为1.0 mA 的最佳实验条件下,氯质量分数在10~1000μg∕g 范围内与荧光强度呈良好的线性关系。主要考察石油醚与甲苯体积比为6∶4的混合物、异辛烷、市售氯标样3种基体对汽油中氯含量测定结果的影响,确定了最佳基体为异辛烷。对该方法进行了准确性和重复性考察,不同牌号汽油和氯形态样品测试结果的回收率均为95%~105%,方法的相对标准偏差小于4.2%。

  1. Analysis of Silicon, Manganese, Phosphorus in Silicon Manganese Alloy by X Ray Fluorescence Spectrometry%X射线荧光光谱法分析硅锰合金中的硅、锰、磷

    Institute of Scientific and Technical Information of China (English)

    李宗超; 曹兴旺; 马文广; 王刚; 金立宁

    2015-01-01

    T he m elting of silicon m anganese alloy production, the use of X ray fluorescence spectrom eter analysis of silicon m anganese alloy, choose the suitable analysis conditions, to determ ine the optim al param eters of the instrum ent, the establishm ent of calibration curves. T he m ethod of m easuring results is consistent results w ith the classical chem ical m ethods. T ests prove that, this m ethod is fast, accurate, m eet the needs of production.%对硅锰合金进行熔融制片,使用X 射线荧光光谱仪对硅锰合金进行分析,选择合适的分析条件,确定仪器最佳参数,建立校准曲线。试验证明,本方法测量结果与经典化学方法结果相吻合,且本方法分析速度快,结果准确,能够满足实际生产需要,可为相关部门提供参考。

  2. Mechanism of fluorescent cocoon sex identification for silkworms Bombyx mori

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    By using silkworms,Bombyx mori, fluorescent cocoon sex identification (FCSI) as an experimental material, direct fluorescence spectrometry of the cocoon surface indicates that the fluorescent color of silkworm cocoons is made up of two peaks of yellow and blue-purple fluorescence emission. The fluorescent difference between male and female cocoons is attributed to the differential absorption of yellow fluorescent substances by the midgut tissue of 5th instar female silkworms. Thin layer chromatography (TLC) and fluorescent spectra indicate that blue-purple fluorescent substances are composed of at least five blue-purple fluorescent pigments, and yellow fluorescent substances are made up of at least three. UV spectra and AlCl3 color reaction show that the three fluorescent yellow pigments are flavonoids or their glycosides. Silkworm FCSI is due to selective absorption or accumulation of the yellow fluorescent pigments by the posterior midgut cells of female 5th instar larvae. The cells of the FCSI silkworm midgut, especially the cylinder intestinal cells of the posterior midgut have a component which is a yellow fluorescent pigment-specific binding protein that may be vigorously expressed in the 5th instar larvae.

  3. S - and N-alkylating agents diminish the fluorescence of fluorescent dye-stained DNA.

    Science.gov (United States)

    Giesche, Robert; John, Harald; Kehe, Kai; Schmidt, Annette; Popp, Tanja; Balzuweit, Frank; Thiermann, Horst; Gudermann, Thomas; Steinritz, Dirk

    2017-01-25

    Sulfur mustard (SM), a chemical warfare agent, causes DNA alkylation, which is believed to be the main cause of its toxicity. SM DNA adducts are commonly used to verify exposure to this vesicant. However, the required analytical state-of-the-art mass-spectrometry methods are complex, use delicate instruments, are not mobile, and require laboratory infrastructure that is most likely not available in conflict zones. Attempts have thus been made to develop rapid detection methods that can be used in the field. The analysis of SM DNA adducts (HETE-G) by immunodetection is a convenient and suitable method. For a diagnostic assessment, HETE-G levels must be determined in relation to the total DNA in the sample. Total DNA can be easily visualized by the use of fluorescent DNA dyes. This study examines whether SM and related compounds affect total DNA staining, an issue that has not been investigated before. After pure DNA was extracted from human keratinocytes (HaCaT cells), DNA was exposed to different S- and N-alkylating agents. Our experiments revealed a significant, dose-dependent decrease in the fluorescence signal of fluorescent dye-stained DNA after exposure to alkylating agents. After mass spectrometry and additional fluorescence measurements ruled out covalent modifications of ethidium bromide (EthBr) by SM, we assumed that DNA crosslinks caused DNA condensation and thereby impaired access of the fluorescent dyes to the DNA. DNA digestion by restriction enzymes restored fluorescence, a fact that strengthened our hypothesis. However, monofunctional agents, which are unable to crosslink DNA, also decreased the fluorescence signal. In subsequent experiments, we demonstrated that protons produced during DNA alkylation caused a pH decrease that was found responsible for the reduction in fluorescence. The use of an appropriate buffer system eliminated the adverse effect of alkylating agents on DNA staining with fluorescent dyes. An appropriate buffer system is thus

  4. Rapid screening of transferrin-binders in the flowers of Bauhinia blakeana Dunn by on-line high-performance liquid chromatography-diode-array detector-electrospray ionization-ion-trap-time-of-flight-mass spectrometry-transferrin-fluorescence detection system.

    Science.gov (United States)

    Liu, Meixian; Dong, Jing; Lin, Zongtao; Niu, Yanyan; Zhang, Xiaotian; Jiang, Haixiu; Guo, Ning; Li, Wei; Wang, Hong; Chen, Shizhong

    2016-06-10

    Transferrin (Transferrin, TRF, TF) has drawn increasing attention in cancer therapy due to its potential applications in drug delivery. TF receptor, highly expressed in tumor cells, recognizes and transports Fe(3+)-TF into cells to release iron into cytoplasm. Thus, discovering TF-binding compounds has become an active research area and is of great importance for target therapy. In this study, an on-line analysis method was established for screening TF-binding compounds from the flowers of Bauhinia blakeana Dunn using a high-performance liquid chromatography-diode-array detector-multi-stage mass spectrometry-transferrin-fluorescence detector (HPLC-DAD-MS(n)-TF-FLD) method. As a result, 33 of 80 identified or tentatively characterized compounds in the sample were TF-binding active. Twenty-five flavonol glycosides and eight phenolic acids were identified as TF-binders. Twelve of these active compounds together with six standard compounds were used to study the dose-response effects and structure-activity relationships of flavonoids and phenolic acids. The method was validated by vitexin with a good linearity in the range of concentrations used in the study. The limit of detection for vitexin was 0.1596 nmol. Our study indicated that the established method is simple, rapid and sensitive for screening TF-binding active compounds in the extract of Bauhinia blakeana Dunn, and therefore is important for discovering potential anti-cancer ingredients from complex samples for TF related drug delivery.

  5. 氢化物发生-非色散原子荧光光谱法同时测定金精矿中痕量铋和汞%Simultaneous determination of trace bismuth and mercury in gold concentrates by hydride generation-nondispersive atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    马熠罡

    2012-01-01

    The method of simultaneous determination of trace bismuth and mercury in gold concentrates by hydride generation-nondispersive atomic fluorescence spectrometry was proposed. The samples were digested by HNO3/HCI and then some references were marked by potassium thiocyanate and thiourea. Calculated the detection limits are 5.6 mg/L and 0. 7 mg/L. The method detection limits are 0. 13 μg/g and 0.012 μg/g,and the precision were 1.2% and 0.6% ,respectively.%采用HNO3/HCl消解,以硫氰化钾掩蔽金,硫脲掩蔽杂质等手段,建立王水消解-双道氢化物发生原子荧光光谱同时测定金精矿中铋和汞含量的新方法.计算出Bi和Hg的检出限分别为5.6,0.7 mg/L,方法的检出限分别为0.13μg/g和0.012 μg/g,精密度分别为1.2%和0.6%.

  6. Speciation of the immediately mobilisable As(III), As(V), MMA and DMA in river sediments by high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry following ultrasonic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Huerga, A. [Departamento de Quimica Analitica y Alimentaria, Area de Quimica Analitica, Facultad de Ciencias (Quimica), Universidad de Vigo, As Lagoas-Marcosende s/n, 36200 Vigo (Spain); Lavilla, I. [Departamento de Quimica Analitica y Alimentaria, Area de Quimica Analitica, Facultad de Ciencias (Quimica), Universidad de Vigo, As Lagoas-Marcosende s/n, 36200 Vigo (Spain); Bendicho, C. [Departamento de Quimica Analitica y Alimentaria, Area de Quimica Analitica, Facultad de Ciencias (Quimica), Universidad de Vigo, As Lagoas-Marcosende s/n, 36200 Vigo (Spain)]. E-mail: bendicho@uvigo.es

    2005-04-04

    In this work, a fast method is developed for the speciation of As(III), As(V), MMA and DMA in the immediately mobilisable fraction of river sediments (i.e. water-soluble and phosphate-exchangeable) by high performance liquid chromatography-hydride generation-atomic fluorescence detection (HPLC-HG-AFD) after extraction using focused ultrasound. The influence of relevant parameters influencing an ion-pairing chromatographic separation following isocratic elution (i.e. amount of MeOH in the mobile phase, ion pair reagent concentration, pH, flow rate) was studied. Focused ultrasound transmitted from an ultrasonic probe provided the same extractable contents as conventional extraction with no changes in the species distribution. The effect of the drying step over extraction of As species was investigated. The following drying procedures were compared: freeze-, oven-, microwave- and air-drying. No influence of the drying operation on the water-extractable fraction was observed. However, freeze- and air-drying yielded significantly higher phosphate-extractable amounts of As(III) and As(V) as compared to oven and microwaves. Detection limits for the As species were in the range 1.3-4.1 ng/g for the water-soluble fraction and 1.6-4.8 ng/g for the phosphate buffer exchangeable fraction. The method was applied to the speciation of immediately mobilisable As(III), As(V), DMA and MMA in 11 sediment samples collected along the beds of the Louro River (southern Galicia, Spain)

  7. Calibration of the (125)I-induced x-ray fluorescence spectrometry-based system of in vivo bone strontium determinations using hydroxyapatite as a phantom material: a simulation study.

    Science.gov (United States)

    Da Silva, Eric; Pejović-Milić, Ana

    2017-06-01

    The calibration of in vivo x-ray fluorescence systems of bone strontium quantification, based on (125)I excitation, is dependent on a coherent normalization procedure. Application of this procedure with the use of plaster of Paris (poP) as a phantom material requires the application of a coherent conversion factor (CCF) to make the calibration functions transferable between the phantom material and human bone. In this work we evaluate, with the use of Monte Carlo simulation, the potential benefit of employing a newly developed hydroxyapatite phantom material into the calibration protocol. Simulations being performed on bare bone phantoms, as the emission spectrum in this case is equivalent to an emission spectrum of an adequately corrected measurement for soft tissue attenuation of emitted strontium signal. We report that the application of hydroxyapatite phantoms does in fact remove the need for a coherent correction factor (CCF). The newly developed phantoms can thus be used for the calibration of in vivo bone strontium systems removing one step of the calibration protocol. Calibration is, however, limited to cases in which the concentration is relative to the amount of calcium in the specimen, which is, the most useful quantity in a clinical sense. Determining concentrations on a per-mass-of-material basis, that is, a concentration not normalized to the calcium content of the phantom/bone, results in large biases in estimated bone strontium content. The use of an HAp phantom material was found to remove the need for a CCF. It was also found that in the case of an incomplete conversion ratio when preparing the phantom material that there would be little effect on the differential coherent cross-section and thereby the coherent normalization-based calibration protocol.

  8. X 射线荧光光谱法测定灰岩中14种主次量元素%Determination of 14 Elements in Limestone by X-ray Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    黄燕华; 张娜

    2014-01-01

    采用 X 射线荧光光谱法对灰岩中的 Ca,Mg,Si,K,Na,Fe,Al,Ti,P,S,Mn,Sr,Ba,Cl 等14种元素进行同时测定,采用硼酸镶边垫底的粉末压样法,优化了测量条件。对比较轻的元素,采用经验影响系数法校正基体效应,对于较重的元素,采用理论α影响系数法校正基体效应。分析标准参考物质 GBW 07132,各元素的精密度(RSD)为0.1%~5.9%,分析标准参考物质 GBW 07130,各元素的测定值与标准值相符,该方法对各元素的测定范围宽、速度快。%A X-ray fluorescence spectrometer was applied to the determination of 14 elements of Ca,Mg,Si,K, Na,Fe,Al,Ti,P,S,Mn,Sr,Ba,Cl in limestone. The method used pressed powder pellet sample preparation, and the analytical condition was optimized. For the ethereal elements,empirical coefficients was used for the correction of matrix effect. For the heavy elements,the theory alpha method was applied. By analyzing standard reference materials,the preci-sions of the method were 0.1%–5.9%,the measure result were in good agreement with certified values. The method is rapid and has a wide determination range.

  9. Comparison of PCR/Electron spray Ionization-Time-of-Flight-Mass Spectrometry versus Traditional Clinical Microbiology for active surveillance of organisms contaminating high-use surfaces in a burn intensive care unit, an orthopedic ward and healthcare workers

    Directory of Open Access Journals (Sweden)

    Yun Heather C

    2012-10-01

    Full Text Available Abstract Background Understanding nosocomial pathogen transmission is restricted by culture limitations. Novel platforms, such as PCR-based electron spray ionization-time-of-flight-mass spectrometry (ESI-TOF-MS, may be useful as investigational tools. Methods Traditional clinical microbiology (TCM and PCR/ESI-TOF-MS were used to recover and detect microorganisms from the hands and personal protective equipment of 10 burn intensive care unit (ICU healthcare workers providing clinical care at a tertiary care military referral hospital. High-use environmental surfaces were assessed in 9 burn ICU and 10 orthopedic patient rooms. Clinical cultures during the study period were reviewed for pathogen comparison with investigational molecular diagnostic methods. Results From 158 samples, 142 organisms were identified by TCM and 718 by PCR/ESI-TOF-MS. The molecular diagnostic method detected more organisms (4.5 ± 2.1 vs. 0.9 ± 0.8, p S. aureus in 13 samples vs. 21 by PCR/ESI-TOF-MS. Gram-negative organisms were less commonly identified than gram-positive by both methods; especially by TCM. Among all detected bacterial species, similar percentages were typical nosocomial pathogens (18-19% for TCM vs. PCR/ESI-TOF-MS. PCR/ESI-TOF-MS also detected mecA in 112 samples, vanA in 13, and KPC-3 in 2. MecA was associated (p S. aureus. No vanA was codetected with enterococci; one KPC-3 was detected without Klebsiella spp. Conclusions In this pilot study, PCR/ESI-TOF-MS detected more organisms, especially gram-negatives, compared to TCM, but the current assay format is limited by the number of antibiotic resistance determinants it covers. Further large-scale assessments of PCR/ESI-TOF-MS for hospital surveillance are warranted.

  10. Investigation on Effect of Fluorescence Enhancement of Danshensu - BSA System by Synchronous Fluorescence Spectrometry%同步荧光光谱法研究丹参素-牛血清白蛋白体系的光增强效应

    Institute of Scientific and Technical Information of China (English)

    张曦; 寇自农; 石羽佳; 朱靖博

    2011-01-01

    Danshensu is one of the water-soluble salvianolic acids which is extracted fl m Salvia. In this article, the interaction between Danshensu and bovine serum albumin (BSA) in aqueous solution was investigated by ultraviolet spectra and synchronous fluorescence spectra. Ultraviolet spectra showed that Danshensu could interact with BSA to form a stable complex. Fluorescence spectra showed that, with the increased concentration of Danshensu, fluorescence intensity (△λ = 15 nm) increased significantly and the maximum emission wavelength was stable at 285 nm, it is right for calculation the binding parameters of Danshensu - BSA. As △λ = 60 nm, the emission spectrum of Danshensu- BSA system showed a blue shift but the fluorescence intensity increased unobviously. The binding parameters of Danshensu - BSA were calculated based on the data of synchronous fluorescence spectra for the first time. The binding constants at 298,308 and 318 K were 1.43 × 106, 1.25 × 106, 5.00 × l05 L/mol, respectively. The thermodynamic parameters ( △H = - 10. 28 kJ/mol, △S > 0) implied that electrostatic force should be the predominant intermolecular force stabilizing the Danshensu - BSA complex.%采用紫外光谱法和同步荧光光谱法研究了丹参素与牛血清白蛋白的结合特性.体系的紫外光谱显示,丹参素与牛血清白蛋白(BSA)之间发生了相互作用并生成新的复合物,同步荧光光谱则表明,丹参素对BSA存在荧光增强效应.随着丹参素浓度的增加,Δλ=15 nm时体系荧光强度明显增强,最大发射波长为285 nm,且不随浓度增加而发生变化.Δλ=60nm时发射光谱出现蓝移,体系荧光强度无明显增强,说明丹参素的加入改变了BSA酪氨酸残基附近的微环境,BSA腔内疏水环境的极性增大,肽链的伸展程度可能有所增加.该文首次以体系的同步荧光光谱为源数据对小分子药物与血清白蛋白的结合参数进行计算.求得25、35、45℃时丹参素与BSA

  11. Simultaneous determination of arsenic and antimony in water by hydride generation-atomic fluorescence spectrometry%同时测定水中砷和锑的氢化物发生-原子荧光光谱法

    Institute of Scientific and Technical Information of China (English)

    宋岳; 周虹

    2012-01-01

    目的 建立双道原子荧光光度计同时测定饮用水中砷和锑的方法,以提高工作效率.方法 选择最佳的仪器条件,进行样品处理方法及酸度、硼氢化钾浓度、检出限、线性范围、精密度、加标回收率等研究.结果 该方法线性关系:砷为0 ~ 80 μg/L,锑为O~40μg/L.检出限:砷为0.087 μg/L,锑为0.19μg/L.相对标准偏差:砷为1.93% ~ 2.55%;锑为1.97% ~3.02%.平均加标回收率:砷为95.7%;锑为96.5%.结论 该方法操作简便,灵敏度高,快速,便于推广,适用于水中砷和锑的同时测定.%[ Objective]To establish the method for simultaneous determination of arsenic and antimony in drinking water by double channel atomic fluorescence spectrometer, improve work efficiency. [Methods]Choosing optimal instrument condition, the sample treatment method, acidity, concentration of potassium borohydride, detection limit, linear range, precision and the recovery of standard addition were studied. [Results]The linear relationship of arsenic and antimony was 0-80μg/L and 0-40 μg/L respectively. The detection limit of arsenic and antimony was 0.087 μg/L and 0.19 μg/L respectively. The relative standard deviation of arsenic and antimony was 1.93% -2. 55% and 1. 97% -3. 02% respectively. The average recovery of standard addition of arsenic and antimony was 95.7% and 96.5% respectively. [ Conclusion] This method has the advantages of simple operation and high sensitivity , it is rapid and easy to spread, which is suitable for simultaneous determination of arsenic and antimony in water.

  12. Determination of arsenic in urine by wet digestion-hydride generation atomic fluorescence spectrometry%湿法消化-氢化物原子荧光法测定尿中砷

    Institute of Scientific and Technical Information of China (English)

    张克梅; 王文静

    2011-01-01

    Objective: To establish an accurate and simple determination of universal detection of arsenic in urine. Methods:Mixed acid sample digestion in the electric panel heating with thiourea, ascorbic acid to pentavalent arsenic to trivalent arsenic pre -reduction, and then potassium borohydride as reducing agent, to 5% HNO3 as the medium, with the AFS-230E direct determination of atomic fluorescence spectrometer. Results: The optimal experimental conditions, good linearity was presented within the arsenic concentration range of 0.0 μg/L ~ 20.0 μg/L; and the correlation coefficient was 0.9999, the lowest detection limit of the method was 0. 164 μg/L, relative standard deviation (RSD) was 0.4% ~ 1.2%, the recovery was 98.6% ~103.5%. Conclusion: The method is simple, precise, which high recovery rate, which is to determine a reliable method ofurinary arsenic.%目的:建立一种准确简单易于普及的测定尿中砷的检测方法.方法:样品用混合酸在电热板上加热消解后,用硫脉抗坏血酸将五价砷预还原为三价砷,再用硼氢化钾作还原剂,以5% HNO3为介质,用AF5-230E原子荧光光度计直接测定.结果:在最佳实验条件下,砷的浓度在0.0 μg/L~20.0 μg/L之间线性关系良好,相关系数r= 0.9999,方法的最低检出限为0.164 μg/L,RSD为0.4%~1.2%,加标回收率为98.6%~103.5%.结论:该方法操作简单,精密度好,回收率高,是测定尿砷含量的可靠方法.

  13. Determination of Inorganic Arsenic in Atmospheric Particles by Hydride Generation-atomic Fluorescence Spectrometry%氢化物发生-原子荧光光谱法测定大气颗粒物中的砷形态

    Institute of Scientific and Technical Information of China (English)

    梁淑轩; 吴虹; 齐学先; 郑璇; 何晓娇

    2011-01-01

    Concentration of atmospheric particles is one of the atmospheric pollution indicators. Heavy metals in the atmospheric particles can risk for human health in both direct and indirect way. Arsenic is one of the higher metal content in them. The inorganic compounds are far more toxic than their organic metabolites. In this paper, the hydride generation atomic fluorescence spectrometric method was employed to the determination of As ( Ⅲ ) and As (V) in the Atmospheric particles. The amount of reducing agent,acid medium and its acidity, carrier gas and shield gas flow rate and observation height of the fluorescence intensity were investigated, and the interference experiment was carried out for concomitant elements. In the best conditions, the detection limit was 0. 34 μg/L, the recovery ranged from 98.18% ~ 102.54%,and the relative standard deviation was about 0.8%. The method was featured by easy operation, fast speed and it has been applied to the analysis of arsenic in the particles with satisfactory results.%采用氢化物发生原子荧光法直接测定不同粒径大气颗粒物中As(Ⅲ)和As(Ⅴ)的含量.研究了还原剂用量、酸介质及其酸度、载气及屏蔽气流量和观测高度等对荧光强度的影响,探讨了共存离子对砷测定的干扰.在选定的最佳条件下,得到检出限为0.34μg/L,方法检出限为0.21μg/g,加标回收率为98.18%~102.54%,相对标准偏差为0.8%左右.用该方法测定大气颗粒物中不同形态的砷,操作简便,快速,灵敏度高.

  14. Study on Occurrence Status Characteristics of Trace Elements in Imported Indonesia Coals of Shanghai Port Using Inductively Coupled Plasma-Mass Spectrometry and Atomic Fluorescence Spectrometry%电感耦合等离子体质谱-原子荧光光谱法研究上海口岸进口印度尼西亚煤炭微量元素的赋存形态特征

    Institute of Scientific and Technical Information of China (English)

    刘曙; 沈劼; 周海明; 诸秀芬; 朱志秀; 李晨; 兰超

    2015-01-01

    Indonesia is the largest coal importer of China. In this paper,the concentrations of 12 elements in 31 imported Indonesia coal samples were determined using Inductively Coupled Plasma-Mass Spectrometry( ICP-MS), atomic Fluorescence Spectrometry( AFS ),Direct Mercury Analyzer. The concentrations of trace elements in imported Indonesia coals were compared and evaluated. The statistical methods of correlation analysis,cluster analysis ,factor analysis were used to obtain some useful information about the possible modes of occurrence of these elements. The study shows that imported Indonesian coals containing high mercury coal,three levels of arsenic coal. The average enrichment coefficient of As,Hg is greater than 1,which suggest the migration risk of As,Hg should be concerned. The average concentrations of Be,Cu,Mo,Cd,Sn,Pb in imported Indonesia coals,lower than the Chinese coal and the world coal,which consistent with low ash content of Indonesia coals. The trace elements in this study can be divided into three categories:the first category is summed up as the clay mineral adsorption,including As,Be,Cr,Co,Hi,Cu,Mo,Cd,Sn,Pb,ash;second into the pyrite type,including Hg,total sulfur;third into the carbonate minerals,including Ba. The research of distribution of trace elements in imported Indonesia coals could provide scientific reference for environmental assessment and clean utilization of imported Indonesia coals.%印度尼西亚是我国最大的煤炭进口国,本文应用电感耦合等离子体质谱、原子荧光光谱、直接测汞仪等技术分析了上海口岸31批进口印度尼西亚煤炭中的12种微量元素,结合数理统计方法研究该类煤炭中微量元素的赋存形态。结果表明,进口印尼煤炭中含有高汞煤、三级含砷煤,As、Hg的平均富集系数大于1,其迁移风险值得关注;Be、Cu、Mo、Cd、Sn、Pb含量均低于中国煤和世界煤炭的平均水平,体现出印尼煤

  15. Method of trivalent chromium concentration determination by atomic spectrometry

    Science.gov (United States)

    Reheulishvili, Aleksandre N [Tbilisi, 0183, GE; Tsibakhashvili, Neli Ya [Tbilisi, 0101, GE

    2006-12-12

    A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

  16. 甲基异丁基甲酮萃取—氢化物发生原子荧光光谱法测定锑锭和氧化锑中汞%Determination of mercury in antimony ingot and antimony oxide by methyl isobutyl ketone extraction-hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    陆建平; 谭芳维; 石建荣

    2012-01-01

    After the samples were dissolved in aqua regia/HBr and tartaric acid was added to mask antimony, then mercury in antimony ingot and antimony oxide was extracted into the organic phase with methyl isobutyl ketone (MIBK) and determined by organic phase injection-intermittent flow injection atomic fluorescence spectrometry. Sample dissolution methods and interferences caused by coexisting ions were investigated, and instrument working conditions, extraction conditions, acidity and other factors were optimized. The results showed that under optimal conditions, the mercury content within the range of 0. 02 to 50 μg/L was in good linear relationship, and the detection limit was 0. 013 jxg/L. This method was applied to the actual antimony ingot and antimony oxide sample analysis. It was found that the results were consistent with those obtained by inductive coupled plasma atomic emission spectrometry with relative standard deviations (RSDs, n = 6) of 0. 65%-2. 4% and recoveries of 94 %-99%.%采用王水/HBr溶解样品,酒石酸掩蔽锑,用甲基异丁基甲酮(MIBK)将汞萃取到有机相中,建立了有机相进样—断续流动注射原子荧光光谱法测定锑锭和氧化锑中汞含量的方法.研究了溶样方法和共存离子可能引起的干扰,优化了仪器工作条件、萃取条件、酸度及其他影响因素.结果表明,在最佳条件下,汞含量在0.02~50 μg/L范围内线性关系良好,方法检出限为0.013 μg/L.将方法应用于锑锭和氧化锑实际样品分析,测得结果与电感耦合等离子体原子发射光谱法一致,相对标准偏差(RSD,n=6)在0.65%~2.4%之间,加标回收率为94%~99%.

  17. Quantitative imaging with fluorescent biosensors.

    Science.gov (United States)

    Okumoto, Sakiko; Jones, Alexander; Frommer, Wolf B

    2012-01-01

    Molecular activities are highly dynamic and can occur locally in subcellular domains or compartments. Neighboring cells in the same tissue can exist in different states. Therefore, quantitative information on the cellular and subcellular dynamics of ions, signaling molecules, and metabolites is critical for functional understanding of organisms. Mass spectrometry is generally used for monitoring ions and metabolites; however, its temporal and spatial resolution are limited. Fluorescent proteins have revolutionized many areas of biology-e.g., fluorescent proteins can report on gene expression or protein localization in real time-yet promoter-based reporters are often slow to report physiologically relevant changes such as calcium oscillations. Therefore, novel tools are required that can be deployed in specific cells and targeted to subcellular compartments in order to quantify target molecule dynamics directly. We require tools that can measure enzyme activities, protein dynamics, and biophysical processes (e.g., membrane potential or molecular tension) with subcellular resolution. Today, we have an extensive suite of tools at our disposal to address these challenges, including translocation sensors, fluorescence-intensity sensors, and Förster resonance energy transfer sensors. This review summarizes sensor design principles, provides a database of sensors for more than 70 different analytes/processes, and gives examples of applications in quantitative live cell imaging.

  18. Determination of inorganic arsenic in coal by hydride generation atomic fluorescence spectrometry combined with ultrasonic extraction%超声提取-顺序注射氢化物发生-原子荧光光谱法测定煤中无机砷

    Institute of Scientific and Technical Information of China (English)

    王长芹; 刘贵勤

    2011-01-01

    A determination method of inorganic arsemc in coal was established by sequence injection hydride generation-atomic fluorescence spectrometry ( HG-AFS) , after the ultrasonic extraction with 6 mol/L HCl as extraction reagent. The ultrasonic extraction conditions were optimized, including extraction reagent, time and temperature. Under the optimized experimental condition, arsemc in concentration range of 0. 20-100 μg/L showed linearity to the fluorescence intensity with correlation coefficient of 0. 999 7. The detection limit of arsenic was 0. 025 μg/L. The relative standard deviation (RSD) for 10 μg/L As was 0. 9 % (n=11). The proposed method has been applied to the analysis of coal fly ash component analysis certified reference material (GBW08401) and coal samples with recoveries of 95%-102 %, and the result of GBW08401 was consist with the certified value.%利用6 mol/L盐酸作为提取试剂,样品经超声提取后,用顺序注射氢化物发生-原子荧光光谱法测定煤中无机砷的含量.对超声提取条件(提取试剂浓度、时间、温度)进行了优化.在优化的实验条件下,砷的浓度在0.20~100μg/L范围内与荧光强度呈线性关系,相关系数为0.999 7,砷的检出限为0.025μg/L,对10 μg/L砷标准溶液进行重复11次测量,得出相对标准偏差(RSD)为0.9%.用该法对煤飞灰成分分析标准物质GBW08401和煤样进行分析,测得回收率在95%~102%之间,标准样品的测定值和认定值相符.

  19. 氢化物发生-原子荧光光谱法直接测定土壤水溶态Sb(Ⅲ)和Sb(Ⅴ)%Direct Determination of Water-Soluble Antimony(Ⅲ) and Antimony(Ⅴ) in Soil by Hydride Generation Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    于兆水; 张勤

    2009-01-01

    在HCl介质中,Sb(Ⅲ)和Sb(Ⅴ)在氢化物发生过程中的化学反应效率不同,通过测定经还原剂还原后和还原前Sb的荧光强度,求解联立方程计算出Sb(Ⅲ)和Sb(Ⅴ)的含量,据此建立了氧化物发生-原子荧光光谱法直接测定土壤水溶态Sb(Ⅲ)和Sb(Ⅴ)方法,操作简便,实用性强.考察了 HCl浓度和KBH_4浓度对Sb(Ⅲ)和Sb(Ⅴ)测定灵敏度的影响以及共存元素的干扰情况,并比较了丽种还原剂对Sb(Ⅴ)的还原效果.方法检出限为Sb(Ⅲ)1.11 ng·g~(-1),Sb(Ⅴ)1.57 ng·g~(-1).加标回收试验表明方法准确、可靠.%A simple, rapid and useful method for the determination of water-soluble antimony( Ⅲ ) and antimony(Ⅴ) in soil was established using hydride generation atomic fluorescence spectrometry. The method was based on the different chemical reaction efficiency between Sb( Ⅲ ) and Sb( Ⅴ ) with KBH_4 in the media of HCL The amounts of Sb( Ⅲ) and Sb( Ⅴ ) can be obtained through measuring antimony fluorescence intensities before and after reduction with reductant. The effects of HCI and KBH_4 on the sensitivities of Sb(Ⅲ) and Sb(Ⅴ) were investigated, and the interferences from coexistent elements were studied. The re-duction efficiencies of both reductants were compared. The detection limits of the method were 1.11 ng·g~(-1) for Sb( Ⅲ ) and 1.57 ng·g~(-1) for Sb( Ⅴ ). The accuracy of the method was verified by recovery experiments on spiked real soil samples.

  20. Determination of 23 Elements in Biological Samples by Wavelength Dispersion X-ray Fluorescence Spectrometry with High Pressure Powder Pelleting Preparation%高压粉末制样波长色散 X射线荧光光谱法测定生物样品中23种元素

    Institute of Scientific and Technical Information of China (English)

    于兆水; 张勤; 李小莉; 樊守忠; 潘晏山; 李国会

    2014-01-01

    In the determination of biological samples by X-ray Fluorescence Spectrometry (XRF),sample powder pellets pressed by traditional sample preparation technique at 220-440 MPa are not compact and smooth,so the sample room of XRF instrument becomes contaminated by dropped sample powder,which can then influence long-term stability.Biological sample powder can be pressed into smooth and compact pellets using high pressure of 1 760 MPa,therefore the sample preparation reproducibility is improved to 0.1% -2.6% (RSD,n=5 ). A method for direct determination of 23 major and minor elements (Al,Ca,Cl,K,Mg,Na,P,S,Si,Ba,Br, Co,Cr,Cu,Fe,Mn,Ni,Pb,Rb,Sr,Ti,V and Zn)in biological samples by Wavelength Dispersion X-ray Fluorescence Spectrometry was established on this sample preparation basis.The matrix effects can be corrected by using Rh-Kα(from the X-ray tube target)Compton-scattered radiation and by using the background as the internal standard.The precision of the method is 0.4%-1 1 .3%(RSD)for most elements and the detection limits is 0.08-1 40.96 μg/g.The feasibility of the proposed method was tested by analyzing several national biological standard materials;the results obtained were consistent with the certified values.%应用X射线荧光光谱法(XRF)分析生物样品时,采用传统低压粉末制样方法(压强220~440 MPa)难以将样品压制成符合测定需要的样片,样片表面粗糙,粉末容易脱落,污染XRF仪器样品室,影响仪器的长期稳定性。本文采用高压粉末制样方法在1760 MPa下压制则完全克服了低压制样的弊端,制备的样片表面光滑、致密,大幅改善了制样重现性,5次制样重现性为0.1%~2.6%,且降低了仪器的维护成本。在此基础上,建立了波长色散X射线荧光光谱法直接测定生物样品中23种主次量元素(Al、Ca、Cl、K、Mg、Na、P、S、Si、Ba、Br、Co、Cr、Cu、Fe、Mn、Ni、Pb、Rb、Sr、Ti、V、Zn)的分析方法

  1. 微波消解-氢化物原子荧光光谱法测定粤东地区海产品中砷的研究%Determination of Arsenic in Seafood by Hydride Generation-atomic Fluorescence Spectrometry Combined with Microwave Oven Digestion

    Institute of Scientific and Technical Information of China (English)

    蔡龙飞; 徐春秀; 张应钦; 邱新红

    2011-01-01

    [目的]建立一种测定海产品中微量砷的有效方法.[方法]采用微波消解-氢化物原子荧光光谱法测定了粤东地区海产品中砷的含量.[结果]砷在1.0~50.0μg/L范围内线性关系良好,相关系数为0.995,方法的检出限为0.02107μg/L,相对标准偏差为0.932%.部分海产品的含砷量超过国家标准,其超标原因可能与沿海地区的工业污染有关.[结论]该方法试剂用量少、污染小、简便、快速、准确,适于各类海产品中砷含量的检测.%[Objective] The aim was to establish an effective determination method of arsenic in seafood. [Method] Contents of arsenic in seafood samples from eastern Guangdong area were determined by hydride generation-atomic fluorescence spectrometry combined with microwave oven digestion. [Result] The linear range for detection of arsenic was 1.0- 50.0 μg/L, which showed a good linear relationship,and its correlation coefficient was 0.995. The detection limit and relative standard deviation were 0.021 07 μg/L and 0.932% .respectively. Contents of arsenic in some seafood samples were more than the national standard,which could be caused by industrial pollution in coastal areas. [Conclusion] The method is simple,rapid and accurate,so it is applied to the determination of arsenic in seafood samples.

  2. Determination of As,Hg and Cd in FAPAS Canned Fish in UK by Hydride Generation-Atomic Fluorescence Spectrometry%氢化物-原子荧光光谱法测定英国FAPAS鱼罐头中砷汞镉

    Institute of Scientific and Technical Information of China (English)

    叶海辉; 谢德芳; 谢轶; 吴学进

    2012-01-01

    [Objective] To prove that the determination of As, Hg and Cd by the hydride generation-atomic fluorescence spectrometry (HG-AFS) has reached the international level of advanced detection instrument. [ Method] The parameters and testing methods of the HG-AFS were optimized. Through the testing of samples and the recovery test, a set of methods were established for determining the three elements in FAPAS canned fish. [Result] By comparing the detection report provided by FAPAS with the results of multiple laboratories, the Z value was -0.2 for As, 0. 5 for Hg, and 0.4 for Cd, the evaluation of results was satisfactory. [ Conclusion] It is feasible'to apply the HG-AFS method for the determination of As, Hg and Cd in seafood products.%[目的]证实原子荧光仪对这砷汞镉3种元素的检测已达到国际先进检测仪器的水平.[方法]利用氢化物-原子荧光光谱法,优化仪器条件参数和试验方法,通过测试质控样品与加标回收试验,建立一套测试英国FAPAS鱼罐头中砷汞镉的方法.[结果]根据FAPAS提供回来的检测报告,与全球众多实验室比对的结果为:砷的Z值为-0.2,汞的Z值为0.5,镉的Z值为0.4,对结果的评价为很满意.[结论]应用氢化物-原子荧光光谱法对海产品中砷汞镉进行检测是可行的.

  3. Simultaneous Determination of Major and Minor Components in Dolomite by X-ray Fluorescence Spectrometry%X射线荧光光谱法同时测定白云岩中氧化钙和氧化镁等主次量组分

    Institute of Scientific and Technical Information of China (English)

    袁秀茹; 余宇; 赵峰; 刘江斌; 陈月源

    2009-01-01

    A method for the determination of CaO, MgO, Al2O3, SiO2, P, MnO, TFe2O3 and S in dolomite by X-ray fluorescence spectrometry with fusion and pressed power pellet sample preparation was developed. The interferences from spectral overlap and matrix effect were corrected by experience alpha coefficient and internal standard with scattered radiation. The method has been applied to the determination of these components in national and provincial standard reference materials and the results are in good agreement with the certified values with precision of less than 10%RSD (n = 12).%针对白云岩主次量组分同时测定中存在的问题,采用熔融玻璃片和粉末压片法制样(运用熔片-压片法相结合),选用有关的国家一级标准物质和省二级标准物质,以经验α系数法和散射线内标法校正元素谱线重叠干扰和基体效应,采用X射线荧光光谱法对白云岩样品中的氧化钙、氧化镁、氧化铝、二氧化硅、磷、氧化锰、全三氧化二铁和硫8个组分进行测定,分析结果与标准值或化学值吻合,各组分12次重复测定的相对标准偏差小于10%.方法操作简便、快捷.

  4. The Determination of Major and Minor Components in Iron Ore by Fused Glass X-ray Fluorescence Spectrometry%熔融玻璃片法X射线荧光光谱测定铁矿石中的主次量组分

    Institute of Scientific and Technical Information of China (English)

    陈忠厚; 薛殿鹏

    2014-01-01

    采用四硼酸锂和偏硼酸锂混合熔剂(质量比为67∶33)为助熔剂制备玻璃片,建立了X射线荧光光谱法测定铁矿石中 Fe2O3、SiO2、Al2O3、CaO、MgO、P、Ti、K2O、Mn等组分含量的方法。以12个铁矿石的标准物质建立校准曲线,研究了溶剂、稀释比例、脱模剂以及温度和时间的影响,用理论α系数法进行回归校正。方法准确、快速、简便。%The preparation of sheet glass were carried out by fusion method , other experimental conditions were confirmed as follow :Li2 B4 O7 -LiBO2 ( mass ratio was 67∶ 33) as compound fusing agent ,A method was introduced for determination of components concentration including Fe2 O3 ,SiO2 ,Al2 O3 ,CaO ,MgO ,P , Ti ,K2 O ,M n in iron ore by X -ray fluorescence spectrometry ,In the standard substances of 12 iron ore as calibration sample , the calibration curve of iron ore , effects of solvent , dilution radio , temperature and time of release agent are studied . By using the theoretical alpha coefficient method for regression calibra-tion is carried out . T he method is accurate , fast , simple .

  5. Electrochemical hydride generation atomic fluorescence spectrometry with a polyanline modified electrode for detection of tin%聚苯胺修饰电极-电化学氢化物发生原子荧光光谱法测定食品中锡含量

    Institute of Scientific and Technical Information of China (English)

    姜宪娟; 淦五二

    2012-01-01

    An electrochemical hydride generation (EC-HG) system with a polyaniline modified electrode (Pan-ME) as cathode material was developed for Sn ( Ⅳ) determination by couped with atomic fluorescence spectrometry. The electrochemical hydride generation efficiency for Sn (Ⅳ) was improved evidently as the Pan membrane could obstruct the aggradation of Sn atom on cathode surface and facilitate the hydride generation. The effects of experimental parameters and interferences have been studied. The limit of detection ( LOD) was 1. 2 ng/mL (3σ) and the relative standard deviation (RSD) was 2. 3% for eleven consecutive measurements of 50 ng/mL Sn(IV) standard solution.%运用以聚苯胺修饰的石墨电极为阴极的电化学氢化物发生装置实现了锡元素的电化学氢化物发生.在电极表面聚合一层聚苯胺,能够有效地提高锡元素的电化学氢化物发生效率,通过与原子荧光光谱仪联用,成功地测定了食品中的锡含量.本工作对各种实验参数和干扰情况进行了详细研究.方法对锡的检出限为1.2 ng/mL(3σ);样品分析精密度(RSD)为2.3% (50 ng/mL,n=11).

  6. Calibration of the High Resolution Gamma Spectrometry Detection Systems from the Environmental Radioactivity Unit and Radiological Surveillance (ARU and RV); Calibracion de los Sistemas Detectores de Espectrometria Gamma de Alta Resolucion de la Unidad de Radiactividad Ambiental y Vigilancia Radiologica (URA y VR)

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Navarro, J. A.; Gasco, C.; Arana, M.; Suanez, A.

    2012-11-01

    In accordance with international regulations and with the quality criteria imposed by the internal quality system of the laboratory of gamma spectrometry, which belongs to the Unit of Environmental Radioactivity and Radiation Monitoring (URA y VR), it is necessary to perform a periodic calibration of the measurement systems of gamma spectrometry. The equipment calibration carries with the need for the preparation of the geometries of measurement and calibration in energy and in efficiencies. This report reflects the procedures for the preparation of the wide range of geometries available in the laboratory, as well as the different calibrations performed with those geometries in almost all the laboratory gamma detectors using the CANBERRA software Genie 2k. (Author) 9 refs.

  7. Tomato seeds maturity detection system based on chlorophyll fluorescence

    Science.gov (United States)

    Li, Cuiling; Wang, Xiu; Meng, Zhijun

    2016-10-01

    Chlorophyll fluorescence intensity can be used as seed maturity and quality evaluation indicator. Chlorophyll fluorescence intensity of seed coats is tested to judge the level of chlorophyll content in seeds, and further to judge the maturity and quality of seeds. This research developed a detection system of tomato seeds maturity based on chlorophyll fluorescence spectrum technology, the system included an excitation light source unit, a fluorescent signal acquisition unit and a data processing unit. The excitation light source unit consisted of two high power LEDs, two radiators and two constant current power supplies, and it was designed to excite chlorophyll fluorescence of tomato seeds. The fluorescent signal acquisition unit was made up of a fluorescence spectrometer, an optical fiber, an optical fiber scaffolds and a narrowband filter. The data processing unit mainly included a computer. Tomato fruits of green ripe stage, discoloration stage, firm ripe stage and full ripe stage were harvested, and their seeds were collected directly. In this research, the developed tomato seeds maturity testing system was used to collect fluorescence spectrums of tomato seeds of different maturities. Principal component analysis (PCA) method was utilized to reduce the dimension of spectral data and extract principal components, and PCA was combined with linear discriminant analysis (LDA) to establish discriminant model of tomato seeds maturity, the discriminant accuracy was greater than 90%. Research results show that using chlorophyll fluorescence spectrum technology is feasible for seeds maturity detection, and the developed tomato seeds maturity testing system has high detection accuracy.

  8. Fundamentals of fluorescence and fluorescence microscopy.

    Science.gov (United States)

    Wolf, David E

    2013-01-01

    This chapter discusses the fundamental physics of fluorescence. The application of fluorescence to microscopy represents an important transition in the development of microscopy, particularly as it applies to biology. It enables quantitating the amounts of specific molecules within a cell, determining whether molecules are complexing on a molecular level, measuring changes in ionic concentrations within cells and organelles, and measuring molecular dynamics. This chapter also discusses the issues important to quantitative measurement of fluorescence and focuses on four of quantitative measurements of fluorescence--boxcar-gated detection, streak cameras, photon correlation, and phase modulation. Although quantitative measurement presents many pitfalls to the beginner, it also presents significant opportunities to one skilled in the art. This chapter also examines how fluorescence is measured in the steady state and time domain and how fluorescence is applied in the modern epifluorescence microscope.

  9. 荧光法和液相色谱-质谱联用法测定司莫司汀导致λDNA交联率的比较研究%Comparative Investigations of Deoxyribonucleic Acid Interstrand Crosslinks Induced by Semustine Using Fluorescence and High Performance Liquid Chromatography-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    赵丽娇; 任婷; 白宝清; 张然; 钟儒刚

    2011-01-01

    司莫司汀是重要的抗癌烷化剂,其抗癌机制与导致DNA股间交联有关.使用荧光法和高效液相色谱-电喷雾串联质谱联用(HPLC-ESI-MS/MS)法对司莫司汀导致的λDNA交联率进行了测定.结果表明:药物浓度为2,4,8和16mmol/L时,荧光方法测得的最大交联率分别为8.81%,11.17%,17.61%,和23.39%;HPLC-ESI-MS/MS方法测得的最大交联率为每10个碱基对中分别含138,256,378和433个dG-dC交联.通过比较,荧光法测得的是交联 DNA 双链的含量,而 HPLC-ESI-MS/MS法测得的是实际交联碱基对的个数,后者更能从本质上揭示交联率的变化规律.两种方法均表明交联反应初期存在一段交联率上升缓慢的"诱导期",这为阐明交联机理提供了依据.%Semustine (Me-CCNU) is an important alkylating agent used in the clinical treatment of cancer. The anticancer mechanism of Me-CCNU is associated with the formation of DNA interstrand crosslinks (ICLs). In this study, the ICLs induced by Me-CCNU were investigated using fluorescent assay and high performance liquid chromatography-electronspray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS). The results showed that the maximum of the crosslinking factor (CF)obtained from fluorescent assay was 8.81%, 11.17%, 17.61% and 23.39%, respectively, with the concentration of Me-CCNU of 2, 4, 8 and 16 mmol/L; the maximum of the CF obtained from HPLCESI-MS/MS was 138, 256, 378 and 433 crosslinked dG-dCs per 107 base pairs, respectively, with the concentration of Me-CCNU of 2, 4, 8 and 16 mmol/L. By comparing these two methods for the determination of DNA interstrand crosslinks, the CF obtained from fluorescent assay characterized the crosslinks of the DNA double strands; on the other hand, the CF obtained from HPLC-ESI-MS/MS characterized the content of the crosslinked dG-dC. The latter gave a more essential quantification of the ICLs than the former. An “induction phase” was found by both of the two methods, in

  10. Reviews in fluorescence 2010

    CERN Document Server

    Geddes, Chris D

    2011-01-01

    ""Reviews in Fluorescence 2010"", the seventh volume of the book serial from Springer, serves as a comprehensive collection of current trends and emerging hot topics in the field of fluorescence and closely related disciplines. It summarizes the year's progress in fluorescence and its applications, with authoritative analytical reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. ""Reviews in Fluorescence"" offers an essential reference material for any lab working in the fluoresc

  11. Principles of fluorescence techniques

    CERN Document Server

    2016-01-01

    Fluorescence techniques are being used and applied increasingly in academics and industry. The Principles of Fluorescence Techniques course will outline the basic concepts of fluorescence techniques and the successful utilization of the currently available commercial instrumentation. The course is designed for students who utilize fluorescence techniques and instrumentation and for researchers and industrial scientists who wish to deepen their knowledge of fluorescence applications. Key scientists in the field will deliver theoretical lectures. The lectures will be complemented by the direct utilization of steady-state and lifetime fluorescence instrumentation and confocal microscopy for FLIM and FRET applications provided by leading companies.

  12. Structural study and fluorescent property of a novel organic microporous crystalline material

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Zhao; Yang, Bingqin; Yang, Meipan; Zhang, Binglin, E-mail: yangbq@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, College of Chemistry and Materials Science, Northwest University (China)

    2014-01-15

    A novel microporous organic material [(2-{2-[2-(bis-methoxycarbonylmethylamino)phenoxy] ethoxy}-4-benzimidazole-phenyl)methoxycarbonylmethylamino]acetic acid methyl ester 6 was synthesized and characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR), electron spray ionization-mass spectrometry (ESI-HRMS), X-ray powder diffraction (PXRD), {sup 1}H and {sup 13}C NMR. 6 crystallizes in the centrosymmetric monoclinic space group C2/c, with unit cell parameters a = 35.648(3) Å, b = 14.3240(12) Å, c = 15.3693(13) Å, a = 90.00, ß = 94.8190(10), γ = 90.00, V = 7820.16 Å{sup 3} and Z = 8 at 296(2) K. As indicated by crystal packing, the molecular conjugation planes arrange along the c axis to form micropores due to the hydrogen bonds. In addition, the fluorescent spectrum and luminescence lifetime were studied for 6. (author)

  13. Fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    Hink, M.A.; Verveer, P.J.

    2015-01-01

    Fluorescence fluctuation spectroscopy techniques allow the quantification of fluorescent molecules present at the nanomolar concentration level. After a brief introduction to the technique, this chapter presents a protocol including background information in order to measure and quantify the molecul

  14. Different Algorithms for Improving Detection Power of Atomic Fluorescence Spectrometry

    Directory of Open Access Journals (Sweden)

    Jian Cui

    2012-11-01

    Full Text Available The purpose of detecting trace concentrations of analytes often is hindered by occurring noise in the signal curves of analytical methods. This is also a problem when different arsenic species (organic arsenic species such as arsanilic acid, nitarsone and roxarsone are to be determined in animal meat by HPLC-UV-HG-AFS, which is the basis of this work. In order to improve the detection power, methods of signal treatment may be applied. We show a comparison of convolution with Gaussian distribution curves, Fourier transform, and wavelet transform. It is illustrated how to estimate decisive parameters for these techniques. All methods result in improved limits of detection. Furthermore, applying baselines and evaluating peaks thoroughly is facilitated. However, there are differences. Fourier transform may be applied, but convolution with Gaussian distribution curves shows better results of improvement. The best of the three is wavelet transform, whereby the detection power is improved by factors of about 2.4

  15. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  16. 超声波水浴辅助消解-原子荧光光谱法测定食用菌中硒含量%Determination of Selenium in Edible Mushrooms by Ultrasonic Assisted Water Bath Digestion-Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴庆晖; 黄伯熹; 冉文清; 荀合; 魏强; 李正全; 陈泳

    2012-01-01

    A method to determine selenium in edible mushroom was developed using ultrasonic assisted water bath digestion followed by atomic fluorescence spectrometry (AFS). The optimum instrumental parameters were established using an orthogonal array design. Besides, the effects of digestion methods and digestion in the presence or absence of potassium ferricyanide on the results of AFS were investigated. AFS was used to determine the selenium contents of different edible mushrooms and the causes of selenium enrichment and the food safety were analyzed based on the results obtained. The limit of detection of the AFS method was 0.20 ng/mL. The sample pretreatment was more efficient and the results of AFS obtained using ultrasonic assisted water bath digestion showed no significant differences compared with wet digestion. AFS can provide a rapid and accurate to analyze selenium in edible mushroom.%为提高检测效率,建立超声波水浴辅助消解.原子荧光光谱法测定食用菌中硒含量的方法。对仪器实验条件进行正交试验优化,对样品前处理方法、铁氰化钾的影响和方法选择性等影响因素进行研究,根据样品检测结果进行原因分析及安全性评价。该方法检出限为0.20ng/mL,加标回收率为91.6%-102.7%。与国标方法对照,提高了样品前处理效率且结果无显著性差异,为食用菌中硒的检测与质量控制提供了一种快速、准确的分析方法。

  17. Purge and Trap Gas Chromatography-Cold Vapor Atomic Fluorescence Spectrometry Determination of Methyl Mercury and Ethyl Mercury in Marine Animals%P & T-GC-CVAFS法测定海产动物中的甲基汞和乙基汞

    Institute of Scientific and Technical Information of China (English)

    崔颖; 肖亚兵; 王禹; 高健会

    2016-01-01

    Marine animals sample was extracted with 30%nitric acid solution , and then adjusted the pH with 2 mol/L sodium acetate-acetic acid buffer solution. The eluate obtained was determined and identified by purge and trap gas chromatography-cold vapor atomic fluorescence spectrometry (P&T-GC-CVAFS). The propylation derivatization converted Methyl mercury (MeHg) to the more volatile methyl propyl mercury (MeHgPr), Ethyl mercury(EtHg) to the more volatile ethyl propyl mercury(EtHgPr), which could be concentrated through purge and trap system with a further clean-up of matrix. Tests for recovery were made by addition of standard MeHg and EtHg solutions at 3 different concentration levels to blank marine animals sample matrixes, values of MeHg recovery found were in the range from 80.5%to 103.2%, with RSDs (n=6) in the range from 1.7%to 6.9%;values of EtHg recovery found were in the range from 84.2%to 103.7%, with RSDs(n=6) in the range from 2.3%to 7.0%.%海产动物样品经过30%硝酸溶液提取,用2 mol/L醋酸钠-醋酸缓冲溶液调节pH后,用吹扫捕集-气相色谱-冷原子荧光光谱仪联用系统测定其中的甲基汞和乙基汞的含量。使用衍生试剂,将甲基汞转化为甲基丙基汞,乙基汞转化为乙基丙基汞,吹扫捕集进行富集并进一步消除基体干扰。以空白样品为基体,添加3种浓度水平的甲基汞和乙基汞标准溶液,测得甲基汞的回收率为80.5%~103.2%,相对标准偏差(n=6)为1.7%~6.9%;乙基汞的回收率在84.2%~103.7%,相对标准偏差(n=6)为2.3%~7.0%。

  18. Simultaneous Determination of Major and Minor Components in Vanadium Slag by Wavelength Dispersive X-ray Fluorescence Spectrometry%波长色散X射线荧光光谱法同时测定钒渣中的主次量成分

    Institute of Scientific and Technical Information of China (English)

    黎香荣; 陈永欣; 罗明贵; 马丽方; 韦新红

    2011-01-01

    采用偏硼酸锂和四硼酸锂混合熔剂熔融法制样,波长色散X射线荧光光谱法同时测定钒渣中的Al2O3、SiO2、CaO、TiO2、MnO、P、V2O5、MgO、Fe、S、Cr2O3等11个主、次量成分.研究了熔剂、预氧化条件、熔样温度、脱模剂等对制样的影响.采用理论α系数校正基体效应及谱线重叠干扰的影响.测定钒渣试样各组分的相对标准偏差(RSD,n=10)在0.1%~7.5%.用钒渣行业级有证标准物质及实际样品验证,测定结果与标准值及其他方法的测定值相符.与化学法相比,该方法具有快速、简便,精密度好,准确度高等优点.%A method for simultaneous determination of major and minor components in vanadium slag samples was provided by using lithium metaborate-lithium tetraborate fusion sample and wavelength dispersive X-ray fluorescence spectrometry. The factors affecting the determination such as flux, pre-oxidation, fusion temperature and release agent were studied in details in this paper. The matrix effect is corrected by the theoretical alpha coefficients. This method has been applied to the standard materials with a RSD of 0.1%-7.5% , and the determination results were consistent with the results obtained by other methods. Compared with classical chemical methods, this method has the advantages of higher accuracy , precision, and more efficiency.

  19. Multi Spectral Fluorescence Imager (MSFI)

    Science.gov (United States)

    Caron, Allison

    2016-01-01

    Genetic transformation with in vivo reporter genes for fluorescent proteins can be performed on a variety of organisms to address fundamental biological questions. Model organisms that may utilize an ISS imager include unicellular organisms (Saccharomyces cerevisiae), plants (Arabidopsis thaliana), and invertebrates (Caenorhabditis elegans). The multispectral fluorescence imager (MSFI) will have the capability to accommodate 10 cm x 10 cm Petri plates, various sized multi-well culture plates, and other custom culture containers. Features will include programmable temperature and light cycles, ethylene scrubbing (less than 25 ppb), CO2 control (between 400 ppm and ISS-ambient levels in units of 100 ppm) and sufficient airflow to prevent condensation that would interfere with imaging.

  20. Fluorescent Approaches to High Throughput Crystallography

    Science.gov (United States)

    Pusey, Marc L.; Forsythe, Elizabeth; Achari, Aniruddha

    2006-01-01

    We have shown that by covalently modifying a subpopulation, less than or equal to 1%, of a macromolecule with a fluorescent probe, the labeled material will add to a growing crystal as a microheterogeneous growth unit. Labeling procedures can be readily incorporated into the final stages of purification, and the presence of the probe at low concentrations does not affect the X-ray data quality or the crystallization behavior. The presence of the trace fluorescent label gives a number of advantages when used with high throughput crystallizations. The covalently attached probe will concentrate in the crystal relative to the solution, and under fluorescent illumination crystals show up as bright objects against a dark background. Non-protein structures, such as salt crystals, will not incorporate the probe and will not show up under fluorescent illumination. Brightly fluorescent crystals are readily found against less bright precipitated phases, which under white light illumination may obscure the crystals. Automated image analysis to find crystals should be greatly facilitated, without having to first define crystallization drop boundaries as the protein or protein structures is all that shows up. Fluorescence intensity is a faster search parameter, whether visually or by automated methods, than looking for crystalline features. We are now testing the use of high fluorescence intensity regions, in the absence of clear crystalline features or "hits", as a means for determining potential lead conditions. A working hypothesis is that kinetics leading to non-structured phases may overwhelm and trap more slowly formed ordered assemblies, which subsequently show up as regions of brighter fluorescence intensity. Preliminary experiments with test proteins have resulted in the extraction of a number of crystallization conditions from screening outcomes based solely on the presence of bright fluorescent regions. Subsequent experiments will test this approach using a wider

  1. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  2. Photoactivation and imaging of optical highlighter fluorescent proteins.

    Science.gov (United States)

    Patterson, George H

    2011-07-01

    A major advance in the microscopic study of cells and tissues is the introduction of photoactivatable fluorescent proteins, which can specifically mark proteins of interest within a living cell. Fluorescent proteins are now available that allow a pool of molecules to be "turned on" by photoactivation. This unit discusses technical aspects for the general use of photoactivatable fluorescent proteins and introduces some specific applications in the concluding remarks.

  3. High Fluorescent Porphyrin-PAMAM-Fluorene Dendrimers.

    Science.gov (United States)

    Garfias-Gonzalez, Karla I; Organista-Mateos, Ulises; Borja-Miranda, Andrés; Gomez-Vidales, Virginia; Hernandez-Ortega, Simon; Cortez-Maya, Sandra; Martínez-García, Marcos

    2015-05-13

    Two new classes of dendrimers bearing 8 and 32 fluorene donor groups have been synthesized. The first and second generations of these porphyrin-PAMAM-fluorene dendrimers were characterized by 1H-NMR, 13C-NMR, FTIR, UV-vis spectroscopy, elemental analyses and MALDI-TOF mass spectrometry. The UV-vis spectra showed that the individual properties of donor and acceptor moieties were preserved, indicating that the new dendrimers could be used as photosynthetic antennae. Furthermore, for fluorescent spectroscopy, these dendrimers showed good energy transfer.

  4. Forensic Mass Spectrometry

    Science.gov (United States)

    Hoffmann, William D.; Jackson, Glen P.

    2015-07-01

    Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Examples of techniques having forensic potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact in the forensic community unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques.

  5. Determination of Lead in Tea Garden Soil by Hydride Generation Atomic Fluorescence Spectrometry with Microwave Digestion%微波消解-氢化物发生原子荧光光谱法测定茶园土壤中的铅

    Institute of Scientific and Technical Information of China (English)

    凤海元; 时晓露; 黄勤

    2013-01-01

    样品用王水微波消解浸提,氢化物发生-原子荧光光谱法测定茶园土壤中痕量铅的含量.对样品浸取方法、实验条件、增感剂和共存元素进行了条件实验.结果表明,王水微波消解浸取,铅浸出量最大,减少了试剂用量和环境污染;铁氰化钾-盐酸羟胺体系有显著的增感作用,铁氰化钾在配制溶液时用米糠除去试剂中可能存在的铅,降低了空白;钴、锌、砷、镉等共存离子不干扰铅的测定,通过加入邻菲啰啉-硫氰酸钠消除铁和铜的干扰,提高了铅的回收率.方法检出限为0.65 μg/L,精密度(RSD,n=10)为1.89%,回收率在86.8% ~ 110.4%之间.用土壤标准物质验证,测定值与标准值相符,方法快速准确,适合于大批量样品的分析检测.%The microwave digestion system with aqua regia was developed for the determination of trace lead in tea garden soil using Hydride Generation-Atomic Fluorescence Spectrometry ( HG-AFS). The leaching methods, experimental conditions, booster and coexisting element were optimized. The largest amount of lead was leached out by microwave digestion with aqua regia, which has the advantages of less usage of reagent and less environmental pollution. An appropriate amount of potassium ferricyanide and hydroxylamine hydrochloride improved the hydride generation efficiency of Pb. The lead blank was reduced significantly when Potassium ferricyanide solution was treated with rice husk to remove Pb in the reagent. It was found that Co, Zn, As, and Cd did not interfere with the determination of lead. The addition of 1,10-phenanthroline monohydrate and sodium hydrosulfide could effectively eliminate the interferences from Fe and Cu, which improved the recovery rate of lead. The limit of detection was 0. 65 μg/L and the precision was 1. 89% (n = 10) with recoveries of 86. 8% - 110. 4% for Pb. The reliability of the method has been tested by determination of Pb in the Soils Standard Reference

  6. Simultaneous Determination of Arsenic and Mercury in Compound Danshen Tablets by Double Channel Atomic Fluorescence Spectrometry%双通道原子荧光法同时测定复方丹参片中砷和汞的含量

    Institute of Scientific and Technical Information of China (English)

    莫迎

    2011-01-01

    目的:建立双通道原子荧光法同时测定复方丹参片中砷和汞的含量.方法:样品采用浓硝酸和过氧化氢混合液进行预消化,再采用微波消解仪在3种条件下进行消化.优化的仪器工作参数:光电倍增管负高压为270 V,砷空心阴极灯总电流为60mA,汞空心阴极灯总电流为30 mA,原子化器高度为8 mm,载气流量为400 ml·min-1,屏蔽气流量为800ml·min-1.结果:本方法砷和汞的线性范围分别为0~60ng·ml-1和0~5 ng·ml-1,相关系数分别为r=0.9998(n=6)和r=0.999 5(n=6),检出限分别为1.38μg·kg-1和0.078μg·kg-1,回收率分别为99.34%和98.38%.结论:本法可用于复方丹参片中砷和汞含量的测定.%Objective: To establish a method for the simultaneous determination of arsenic and mercury in compound Danshen tablets by double channel atomic fluorescence spectrometry.Method: The samples were pre-dissolved by nitric acid and hydrogen peroxide, then digested completely using microwave digestion device under 3 different conditions.The measurement conditions were as the follows: the negative high pressure of photomultiplier tubes was 270 v, total current of As hollow cathode lamp was 60 mA and 30 mA for Hg hollow cathode lamp, height of atomizer was 8 mm, carrier gas flow was 400 ml· min -1 and 800 ml· min -1 for shielding gas.Result: The linear range was 0-60 ng·ml-1 and 0-5 ng·ml -1 for arsenic and mercury with the correlation coefficient of 0.999 8( n =6) and 0.9995 ( n = 6 ), respectively.The detection limit of arsenic and mercury was 1.38 μg· kg - 1 and 0.078 μg · kg - 1, and the recovery was 99.34% and 98.38%, respectively.Conclusion: The method can be used for the simultaneous detection of arsenic and mercury in compound Danshen tablets.

  7. Determination of Composition in PM10 Aerosols by High-Energy Polarized Energy-Dispersive X-ray Fluorescence Spectrometry%高能偏振能量色散-X射线荧光光谱法测定PM10大气颗粒物的组成

    Institute of Scientific and Technical Information of China (English)

    吉昂; 郑南; 王河锦; 徐子优; 李国会

    2011-01-01

    In order to coordinate with X-ray Diffractomer (XRD) research on analyzing the crystal phase of inhaled aerosol PM10 qualitatively and quantitatively, a method of using High-Energy Polarized Energy-Dispersive X-ray Fluorescence Spectrometry (HE-P-EDXRF) was developed to quantitatively measure the major and minor elements in aerosol PM10 collected on Whatman glass fiber filters. The study focused on the effect of the blank values of air filter membrane for the measurement compositions of aerosol PM10. The results indicate that the standards with glass fiber membrane filter should be used as carriers if the elemental area density of the blank glass fiber filter is more than 0. 1 μg/cm3, and the nuclepore polycarbonate aerosol membrane filter should be used if the elemental area density is less than 0. 1 μg/cm3. The measurement of heavy trace elements using He-P-EDXRF was also investigated, and extended the scope of the measuring elements to 62. The detection limits of Na, Mg, S, Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu were more than 0. 1 μg/m2, the detection limits of Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br and Rb were less than 0.01 μg/m2, and the detection limits of Cl, Al, Si, P, K, Sc, Ti, V, Ge, As, Br, Se, Sr, Zr, Mo, Pd, Rh, In, Nb, Ag, Cd, Te, Sb, Sn, Ba, Cs, La, Ce, Pr, Au, Pt, W, Tl, Pb, Bi, Th and U were 0. 1 -0.01 μg/cm2.%为配合X射线衍射分析(XRD)方法对可吸入大气颗粒悬浮物(PM10)的结晶物相进行定性和定量分析的研究工作,本文应用高能偏振能量色散X射线荧光光谱(HE- P-EDXRF)对Whatman玻璃纤维滤膜采集的PM10颗粒物中主、次量元素进行定量分析,着重研究了空气滤膜空白值对测定PM10颗粒物中组成的影响.结果表明,当玻璃纤维滤膜空白值中元素的面密度大于0.1μg/cm2时,需使用玻璃纤维滤膜为载体的标准样品;元素的面密度小于0.1μg/cm2时,可用聚碳酸脂膜为载体的标准样品.对HE-P-EDXRF谱仪测定PM10颗粒物中

  8. Determination of Water Soluble As ( Ⅲ ) and As ( Ⅴ ) in Soil by Hydride Generation-Atomic Fluorescence Spectrometry%氢化物发生-原子荧光光谱法测定土壤中水溶态砷(Ⅲ)和砷(Ⅴ)

    Institute of Scientific and Technical Information of China (English)

    于兆水; 张勤; 刘玲

    2012-01-01

    以氢气发生器为氩-氢火焰提供纯净、稳定的氢气,原子荧光光谱法测定土壤中水溶态和可交换态Sb(Ⅲ)和Sb(Ⅴ)已有应用,本研究进一步将此方法用于测定土壤样品中的As(Ⅲ)和As(Ⅴ).在0.3mol/L NaH2PO4 - Na2HPO4缓冲液中,采用氢化物发生-原子荧光光谱法测定土壤中水溶态As(Ⅲ)和总砷的含量,通过差减法计算As(Ⅴ)的含量.实验考察了0.02~0.4 mol/L NaH2PO4 - Na2 HPO4对As(Ⅲ)和As(Ⅴ)测定的影响,结果表明0.3 mol/L NaH2PO4 - Na2HPO4可以有效掩蔽As(Ⅴ).As(Ⅲ)的检出限为2.92 ng/g,总砷的检出限为2.35 ng/g;As(Ⅲ)和As(Ⅴ)的加标回收率分别为96% ~ 104%和101% ~103%.本方法不再依靠化学反应产生氢气来点燃并维持氩氢火焰,可在发生氢化反应的任何介质中测定砷,且不需要考虑酸度问题.方法操作简便,准确度高,能满足大批量样品分析要求.%Based on the determination method of Sb ( HI) and Sb ( V ) in soil, a method for the determination of water soluble As ( M ) and total arsenic in soil has been established by using Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS) in the media of 0. 3 mol/L NaH2PO4-Na2HPO4. An amount of As( V ) was obtained by subtracting As( HI ) from total arsenic. The hydrogen was provided from a hydrogen generator instead of chemical reaction to ignite a H2-Ar flame. Therefore, arsenic in any media was measurable since the arsenic was reduced into AsH3. Effects on the determination of As ( M ) and As ( V ) were investigated for concentrations of NaH2PO4-Na2HPO4 from 0. 02 mol/L to 0. 4 mol/L. The results show As( V ) can be screened by 0. 3 mol/L NaH2PO4-Na2HPO4. The detection limits were 2. 92 ng/g for As( HJ ) and 2. 35 ng/g for total As. The recoveries of As( HI) and As( V ) are 96% - 104% and 101% - 103% , respectively. The method was simple and highly accurate, meeting the requirements for multiple sample analysis.

  9. 水产品中甲基汞测定的液相色谱-原子荧光光谱联用方法的改进%Improvement of the method for methylmercury determination in aquatic products using liquid chromatography online coupled with atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    尚晓虹; 赵云峰; 张磊; 李筱薇; 吴永宁

    2011-01-01

    The improvement method was developed for methylmercury determination using liquid chromatography online coupled with cold vapor atomic fluorescence spectrometry ( LC-CVAFS ). 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 methyl-mercury was 1 - 50 μg/L and the limit of detection ( S/N = 3 ) for methylmercury was 0.3 μg/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 μg/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 methylmer-cury determination in seafood.%对本实验室前期建立的食品中甲基汞的液相色谱-原子荧光光谱联用测定方法进行了改进.采用无毒的半胱氨酸代替有毒试剂巯基乙醇作为流动相中的配位剂,流动相组成为5%(v/v)乙腈-1 g/L半胱氨酸-50 mmol/L乙酸铵水溶液,使汞化合物分离时间缩短至8 min.在优化条件下,甲基汞标准曲线的线性范围为1~50 μg/L,检出限(S/V=3)为0/3

  10. Determination of seven elements in laterite nickel ore by portable energy dispersive X-ray fluorescence spectrometry%便携式能量色散X射线荧光光谱仪测定红土镍矿中7种元素

    Institute of Scientific and Technical Information of China (English)

    屈太原; 李华昌; 冯先进

    2012-01-01

    选取具有代表性的红土镍矿样品为校准样品,建立了便携式能量色散X射线荧光光谱仪直接测定粉末红土镍矿样品中Fe、Ni、Cr、Mn、Ti、Zn、Ca含量的分析方法.实验采用滴定法对校准样品中主量元素铁,电感耦合等离子体原子发射光谱法(ICP-AES)对其它元素进行定值,解决了红土镍矿标准样品短缺的问题.对校准样品的前处理方法及测定条件等进行了探讨,并通过研磨使校准样品与测试样品达到相同颗粒度以降低颗粒效应的干扰,同时利用仪器自带的NDTr软件,以基本参数法(FP法)自动校正元素间相互干扰效应.精密度试验结果表明,各组分相对标准偏差(n=7)在0.16%~8.3%之间.方法用于红土镍矿实际样品分析,测定结果与湿法分析结果吻合,能够满足现场大批量样品主次元素同时快速分析的需要.%A direct determination method of Fe, Ni, Cr, Mn, Ti, Zn and Ca in powdered laterite nickel ore by portable energy dispersion X-ray fluorescence spectrometer was established using representative laterite nickel ore samples as calibration sample. The main element iron in calibration sample was certified by titration, while other elements were certified by inductively coupled plasma atomic emission spectrometry (ICP-AES). This solved the shortage problem of laterite nickel ore certified reference materials. The pretreatment methods of calibration sample and determination conditions were discussed. The particle size of calibration sample and testing sample was ground to the same level to reduce the interference of grain effect. Meanwhile, the mutual interference effect among elements was automatically corrected by fundamental parameter method (FP) with the NDTr software in instrument. The results of precision test indicated that, the relative standard deviations (RSD, n = 7) of testing elements were 0.16 %-8. 3 %. The proposed method was applied to the determination of actual laterite

  11. Analysis of X-Ray Fluorescence Spectroscopy and Plasma Mass Spectrometry of the Guidong Granite Body and Its Implications to Granite Evolution%贵东岩体X荧光光谱、等离子体质谱分析结果及其对岩体演化的指示意义

    Institute of Scientific and Technical Information of China (English)

    李宏卫; 陈国能; 彭卓伦

    2013-01-01

    粤北贵东岩体是由形成于早侏罗世(燕山一期)的粗粒黑云母花岗岩、晚侏罗世(燕山三期)的中细粒二云母或白云母花岗岩、早白垩世(燕山四期)石英正长岩组成的复式岩体.不同期次花岗岩进行X荧光光谱和等离子体质谱测试结果显示:(1)同期岩体自上而下具有硅碱组分降低,铁镁含量组分和LREE,LREE/HREE及(La/Yb),N值总体升高的变化趋势;(2)复式岩体从早期到晚期,岩体的硅碱组分逐渐升高,而∑REE,LREE/HREE,(La/Yb)N及δEu值则逐渐降低,稀土配分曲线由右倾型向海鸥型过渡,表明复式岩体的形成是地壳岩石多次原地熔融(重熔)的结果;(3)微量元素组成同样反映复式岩体形成是地壳岩石多次原地熔融(重熔)的结果;多次熔融(重熔)导致晚期岩体U丰度和U/Th比值升高,故该区铀矿床的形成多与燕山晚期的熔融(重熔)事件有关.%The Guidong composite granite body (CGB) located in the north Guangdong Province consists of numerous rock bodies formed respectively in the early and late Jurassic and early Cretaceous.Analysis of the granites of different period with X ray fluorescence spectroscopy and plasma mass spectrometry indicates:(1) From the top of a granite body downwards,the felsic components of rock decrease,while the mafic and ∑REE,LREE/HREE,(La/Yb)N,as well as δ Eu value increase,suggesting the material differentiation in the in-situ melting of crustal rocks and crystallisation of magma; (2) From old to young of the different period granite-massifs in the Guidong CGB,the felsic compositions totally decrease,and the mafic components,∑REE,LREE/HREE,(La/Yb)N,and δ Eu value increase as well,implying multiple crustal melting (remelting) events in the Mesozoic in this area; and (3) Primitive mantle-normalized spider diagram for trace elements of Guidong CGB suggests high maturity of the crust involved in the in-situ melting.

  12. Determination of arsenic in antimony ingot and antimony trioxide by hydride generation-atomic fluorescence spectrometry%氢化物发生-原子荧光光谱法测定锑锭及三氧化二锑中的砷

    Institute of Scientific and Technical Information of China (English)

    钱光敏; 赵国杏

    2012-01-01

    The antimony slab and antimonous oxide samples were dissolved by sulfuric acid and hydrochloric acid, respectively. The Sb3+ in solution was precipitated with sodium hydroxide to separate trace arsenic from matrix antimony. The thiourea-ascorbic acid was added to reduce As5+ to As3+. Then, the arsenic in antimony slab and antimonous oxide was determined by atomic fluorescence spec-trometry. The hydride generation conditions were investigated: the concentration of reducing agent potassium borohydride was 25 g/L, the determination medium was 20% (V/V) hydrochloric acid, and the dosage of thiourea - ascorbic acid solution was 5 mL. The interference test of coexisting elements showed that, the interference of residual antimony in solution after precipitation could be fully eliminated by adding 1 mL of tartaric acid solution. Other impurity elements in sample did not interfere with the determination of arsenic after adding thiourea-ascorbic acid solution. The detection limit of method was 0. 156 ng/mL. The antimony slab and antimonous oxide samples were analyzed by the proposed method, and the relative standard deviation (RSD) was 0. 95%-1.2%. The determination results were consistent with those obtained by national standard methods.%采用硫酸溶解锑锭样品,盐酸溶解三氧化二锑样品,用氢氧化钠溶液使Sb3+沉淀从而使基体锑与微量砷分离,通过加入硫脲-抗坏血酸将As5+还原成As3+,然后在原子荧光仪上测定锑锭及三氧化二锑中的砷.对氢化物发生条件进行考察,确定还原剂硼氢化钾的浓度为25 g/L、测定介质为20%(V/V)盐酸、硫脲-抗坏血酸溶液用量为5 mL.共存元素干扰试验表明,沉淀后溶液中残留少量锑的干扰在加入1 mL酒石酸溶液后可以完全消除,而样品中其他杂质元素在加入硫脲-抗坏血酸溶液后不干扰砷的测定.方法的检出限为0.156 ng/mL.对锑锭及三氧化二锑样品进行分析,相对标准偏差为0.95%~1.2%,测定

  13. THE DETERMINATION OF ANTIMONY (Ⅲ) AND ANTOMONY (Ⅴ) IN GEOLOGICAL SAMPLES BY HYDRIDE GENERATION-ATOMIC FLUORESCENCE SPECTROMETRY%氢化物发生—原子荧光光谱法测定地质样品中的锑(Ⅲ)和锑(Ⅴ)

    Institute of Scientific and Technical Information of China (English)

    郝志红; 杨帆; 刑夏; 汤志勇; 张勤

    2012-01-01

    A method for the determination of antimony ( Ⅲ ) and antimony ( V ) in geological samples (stream sediments) by hydride generation-atomic fluorescence spectrometry was developed in the paper. 4. 8 mol/L HC1 could be used as the extraclant with ultrasonic-assisted extraction. In the medium of 0. 24 mol/L hydrochloric acid, antimony ( Ⅲ) could be alternatively determined with 6 g/mL sodium citrate as the masking agent for Sb (V). Then antimony ( V ) could be figured out by the subtraction method. The detection limit of the method was 0. 075 × 10 -6 for Sb ( 1) and 0. 097 × 10 -6 for Sb ( V ) , and the relative standard deviation was 1. 1 % and 0. 64% ( n = 11) for 40 ng/mL Sb ( Ⅲ ) and 40 ng/mL Sb( V ) standard solution. The proposed method was applied to the determination of antimony ( Ⅲ) and antimony ( V ) in geological samples, and a comparison between the extraction results and the aqua regia dissolution results shows that the extraction rate of antimony was higher than 80% , the recoveries were in the ranges of 83% - 107% and 98% -114% for Sb ( Ⅲ) and Sb (V) respectively.%提出了一种氢化物发生—原子荧光光谱法测定地质样品(水系沉积物)中Sb(Ⅲ)和Sb(Ⅴ)的方法.选取4.8 mol/L HC1为提取剂,采用超声波辅助提取,以6 g/mL柠檬酸钠作为Sb(Ⅴ)的掩蔽剂,在0.24 mol/L的HC1介质中选择性测定Sb(Ⅲ),用差减法求得Sb(Ⅴ).Sb(Ⅲ)的方法检出限为0.075×10-6,Sb(Ⅴ)的方法检出限为0.097×10-6.对40 ng/mL的Sb(Ⅲ)和Sb(Ⅴ)分别连续测定11次,得到相对标准偏差分别为1.1%和0.64%.应用该方法对地质样品中的Sb(Ⅲ)和Sb(Ⅴ)进行分析测定,并与王水溶解值相比较,该方法测定的总Sb提取率在80%以上,Sb(Ⅲ)和Sb(Ⅴ)的加标回收率分别为83% ~ 107%和98% ~ 114%.

  14. Fluorescence antibunching microscopy

    CERN Document Server

    Schwartz, Osip

    2011-01-01

    Breaking the diffraction limit in microscopy by utilizing quantum properties of light has been the goal of intense research in the recent years. We propose a quantum superresolution technique based on non-classical emission statistics of fluorescent markers, routinely used as contrast labels for bio-imaging. The technique can be readily implemented using standard fluorescence microscopy equipment.

  15. Fluorescence of atopic allergens

    NARCIS (Netherlands)

    Berrens, L.

    1967-01-01

    Purified atopic allergens have been found to emit flue fluorescence upon irradiation with ultraviolet light of 365 mμ wavelength. The maximum of fluorescence is in the region 445–490 mμ and the intensity is of the same order of magnitude for different atopic allergens. Synthetic model compounds, inc

  16. Fluorescent Lamp Replacement Study

    Science.gov (United States)

    2017-07-01

    Light-emitting diode, LED, lighting, fluorescent, waste reduction, energy conservation, net zero , mercury 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...Center (ATC) to assess the benefits of converting fluorescent tube lighting to light-emitting diode (LED) technology. The report documents the waste ...1-15 SECTION 2. SUBTESTS 2.1 HAZARDOUS WASTE REDUCTION

  17. LEDs for fluorescence microscopy

    NARCIS (Netherlands)

    Young, I.T.; Garini, Y.; Dietrich, H.R.C.; Van Oel, W.; Liqui Lung, G.

    2004-01-01

    Traditional light sources for fluorescence microscopy have been mercury lamps, xenon lamps, and lasers. These sources have been essential in the development of fluorescence microscopy but each can have serious disadvantages: lack of near monochromaticity, heat generation, cost, lifetime of the light

  18. Fourier transform mass spectrometry.

    Science.gov (United States)

    Scigelova, Michaela; Hornshaw, Martin; Giannakopulos, Anastassios; Makarov, Alexander

    2011-07-01

    This article provides an introduction to Fourier transform-based mass spectrometry. The key performance characteristics of Fourier transform-based mass spectrometry, mass accuracy and resolution, are presented in the view of how they impact the interpretation of measurements in proteomic applications. The theory and principles of operation of two types of mass analyzer, Fourier transform ion cyclotron resonance and Orbitrap, are described. Major benefits as well as limitations of Fourier transform-based mass spectrometry technology are discussed in the context of practical sample analysis, and illustrated with examples included as figures in this text and in the accompanying slide set. Comparisons highlighting the performance differences between the two mass analyzers are made where deemed useful in assisting the user with choosing the most appropriate technology for an application. Recent developments of these high-performing mass spectrometers are mentioned to provide a future outlook.

  19. Development of Enantioselective Fluorescent Sensors for Chiral Recognition

    Institute of Scientific and Technical Information of China (English)

    Lin Pu

    2004-01-01

    Novel chiral compounds have been synthesized for the enantioselective fluorescent recognition of alpha-hydroxycarboxylic acids and amino acids. By introducing dendritic branches to the chiral receptor units, the fluorescence signals of the receptors are significantly amplified because of the light-harvesting effect of the dendritic structure. This has greatly increased the sensitivity of the sensors in the fluorescent recognition. Highly enantioselective fluorescent responses have also been achieved. These sensors are potentially useful for the high throughput screening of chiral catalysts for asymmetric synthesis.

  20. Temperature-dependent fluorescence lifetime of a fluorescent polymeric thermometer, poly(N-isopropylacrylamide), labeled by polarity and hydrogen bonding sensitive 4-sulfamoyl-7-aminobenzofurazan.

    Science.gov (United States)

    Gota, Chie; Uchiyama, Seiichi; Yoshihara, Toshitada; Tobita, Seiji; Ohwada, Tomohiko

    2008-03-13

    Fluorescent molecular thermometers showing temperature-dependent fluorescence lifetimes enable thermal mapping of small spaces such as a microchannel and a living cell. We report the temperature-dependent fluorescence lifetimes of poly(NIPAM-co-DBD-AA), which is a random copolymer of N-isopropylacrylamide (NIPAM) and an environment-sensitive fluorescent monomer (DBD-AA) containing a 4-sulfamoyl-7-aminobenzofurazan structure. The average fluorescence lifetime of poly(NIPAM-co-DBD-AA) in aqueous solution increased from 4.22 to 14.1 ns with increasing temperature from 30 to 35 degrees C. This drastic change in fluorescence lifetime (27% increase per 1 degrees C) is the sharpest ever reported. Concentration independency, one of the advantages of fluorescence lifetime measurements, was seen in average fluorescence lifetime (13.7 +/- 0.18 ns) of poly(NIPAM-co-DBD-AA) at 33 degrees C over a wide concentration range (0.005-1 w/v%). With increasing temperature, polyNIPAM units in poly(NIPAM-co-DBD-AA) change their structure from an extended form to a globular form, providing apolar and aprotic environments to the fluorescent DBD-AA units. Consequently, the environment-sensitive DBD-AA units translate the local environmental changes into the extension of the fluorescence lifetime. This role of the DBD-AA units was revealed by a study of solvent effects on fluorescence lifetime of a model environment-sensitive fluorophore.

  1. Capillary electrophoresis with laser-induced fluorescence: environmental applications.

    Science.gov (United States)

    Riddick, Lee; Brumley, William C

    2008-01-01

    Capillary electrophoresis (CE), especially free-zone CE, offers a relatively simple separation with moderate selectivity based on the mobility of ions in solution. Laser-induced fluorescence (LIF) detection, an extremely sensitive technique, can be coupled with a variety of separation conditions to achieve sensitive and quantitative results. When these techniques are combined, CE/LIF provides the sensitivity and increased selectivity that makes trace level environmental analysis of fluorescent compounds possible at or below levels typical for gas chromatography (GC)/mass spectrometry (MS). We offer a panoramic review of the role of these tools in solving environmental and related analytical problems before providing a detailed experimental protocol.

  2. 人血和尿中锡的高压微波络合消解氢化物发生-原子荧光测定法%Determination of tin in human blood and urine with high-pressure microwave digestion and complexing ligand and hydride generation-atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    陈峰; 谢超

    2013-01-01

    Objective To establish the hydride generation-atomic fluorescence spectrometric method for the determination of tin in human blood and urine with high-pressure microwave digestion and complexing ligand.Methods Human blood and urine samples were digested by using high-pressure microwave.Then complexing ligand 1% EDTA,5 ml 150 g/L thiourea and ascorbic acid were added to mask the interfering ions such as nickel,iron,arsenic,selenium and etc.Tin concentration was determined with hydride-generation atomic fluorescence spectrometric method with sodium borohydride as the reductant in 2% sulphuric acid media.Results The linear range of tin was 10-100 μg/ml,the regression equations and correlation coefficients in blood and urine were y=9.391 1 x-16.312,r=0.999 7,y=8.244 7x-27.849 6,r=0.998 2,respectively.The limits of detection of tin in blood and urine were 0.090,0.020 μg/L respectively.The relative standard derivation of this method was 1.4%-6.1%.The rates of recovery were between 98.1% and 101.8%.Conclusion This method presents many advantages,such as completed sample digestion,rapid,less matrix disturbance,accurate,sensitive and is applicable to the determination of tin in blood and urine in grass-roots units.%目的 建立人血、尿中锡的高压微波络合消解氢化物发生-原子荧光测定法.方法 利用高压微波络合消解已加入1% EDTA溶液的人血和尿液,在样品测定液中加入150 g/L硫脲-抗坏血酸5ml来掩蔽镍、铁、砷、硒等干扰离子;以2%硫酸作为介质,以2%的硼氢化钠溶液作为还原剂,采用氢化物发生-原子荧光法测定锡浓度.结果 在10~100 μg/ml的线性范围内,血中锡所得回归方程为y=9.391 1x-16.312,r=0.999 7;尿中锡所得回归方程为y=8.244 7x-27.849 6,r=0.998 2.血、尿中锡的检出限分别为0.090、0.020 μg/L.该方法的RSD为1.4%~6.1%,回收率在98.1%~101.8%之间.结论 该方法样品消解完全,测定时间短,待测元素

  3. Fluorescence and Spectral Imaging

    Directory of Open Access Journals (Sweden)

    Ralph S. DaCosta

    2007-01-01

    Full Text Available Early identification of dysplasia remains a critical goal for diagnostic endoscopy since early discovery directly improves patient survival because it allows endoscopic or surgical intervention with disease localized without lymph node involvement. Clinical studies have successfully used tissue autofluorescence with conventional white light endoscopy and biopsy for detecting adenomatous colonic polyps, differentiating benign hyperplastic from adenomas with acceptable sensitivity and specificity. In Barrett's esophagus, the detection of dysplasia remains problematic because of background inflammation, whereas in the squamous esophagus, autofluorescence imaging appears to be more dependable. Point fluorescence spectroscopy, although playing a crucial role in the pioneering mechanistic development of fluorescence endoscopic imaging, does not seem to have a current function in endoscopy because of its nontargeted sampling and suboptimal sensitivity and specificity. Other point spectroscopic modalities, such as Raman spectroscopy and elastic light scattering, continue to be evaluated in clinical studies, but still suffer the significant disadvantages of being random and nonimaging. A recent addition to the fluorescence endoscopic imaging arsenal is the use of confocal fluorescence endomicroscopy, which provides real-time optical biopsy for the first time. To improve detection of dysplasia in the gastrointestinal tract, a new and exciting development has been the use of exogenous fluorescence contrast probes that specifically target a variety of disease-related cellular biomarkers using conventional fluorescent dyes and novel potent fluorescent nanocrystals (i.e., quantum dots. This is an area of great promise, but still in its infancy, and preclinical studies are currently under way.

  4. Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    le Gac, S.; le Gac, Severine; van den Berg, Albert; van den Berg, A.; Unknown, [Unknown

    2009-01-01

    With this book we want to illustrate how two quickly growing fields of instrumentation and technology, both applied to life sciences, mass spectrometry and microfluidics (or microfabrication) naturally came to meet at the end of the last century and how this marriage impacts on several types of appl

  5. Analytical mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  6. Analytical mass spectrometry. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This 43rd Annual Summer Symposium on Analytical Chemistry was held July 24--27, 1990 at Oak Ridge, TN and contained sessions on the following topics: Fundamentals of Analytical Mass Spectrometry (MS), MS in the National Laboratories, Lasers and Fourier Transform Methods, Future of MS, New Ionization and LC/MS Methods, and an extra session. (WET)

  7. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M [Santa Fe, NM; Waldo, Geoffrey S [Santa Fe, NM; Kiss, Csaba [Los Alamos, NM

    2012-05-01

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  8. Highly thermostable fluorescent proteins

    Science.gov (United States)

    Bradbury, Andrew M.; Waldo, Geoffrey S.; Kiss, Csaba

    2011-03-22

    Thermostable fluorescent proteins (TSFPs), methods for generating these and other stability-enhanced proteins, polynucleotides encoding such proteins, and assays and method for using the TSFPs and TSFP-encoding nucleic acid molecules are provided. The TSFPs of the invention show extremely enhanced levels of stability and thermotolerance. In one case, for example, a TSFP of the invention is so stable it can be heated to 99.degree. C. for short periods of time without denaturing, and retains 85% of its fluorescence when heated to 80.degree. C. for several minutes. The invention also provides a method for generating stability-enhanced variants of a protein, including but not limited to fluorescent proteins.

  9. Limitation of fluorescence spectrophotometry in the measurement of naphthenic acids in oil sands process water.

    Science.gov (United States)

    Lu, Weibing; Ewanchuk, Andrea; Perez-Estrada, Leonidas; Sego, Dave; Ulrich, Ania

    2013-01-01

    Fluorescence spectrophotometry has been proposed as a quick screening technique for the measurement of naphthenic acids (NAs). To evaluate the feasibility of this application, the fluorescence emission spectra of NAs extracted from three oil sands process water sources were compared with that of commercial NAs. The NAs resulting from the bitumen extraction process cannot be differentiated because of the similarity of the fluorescence spectra. Separation of the fluorescent species in NAs using high performance liquid chromatography with fluorescence detector proved unsuccessful. The acidic fraction of NAs is fluorescent but the basic fraction of NAs is not fluorescent, implying that aromatic acids in NAs give rise to the fluorescent signals. The concentrations of NAs in oil sands process water were measured by Fourier transform infrared spectroscopy (FTIR), fluorescence spectrophotometry and ultra high performance liquid chromatography-time of flight/mass spectrometry (UPLC-TOF/MS). Commercial Merichem and Kodak NAs are the best standards to use when measuring NAs concentration with FTIR and fluorescence spectrophotometry. In addition, the NAs concentrations measured by fluorescence spectrophotometry are about 30 times higher than those measured by FTIR and UPLC-TOF/MS. The findings in this study underscore the limitation of fluorescence spectrophotometry in the measurement of NAs.

  10. 78 FR 16709 - Certain Cold Cathode Fluorescent Lamp (“CCFL”) Inverter Circuits and Products Containing Same...

    Science.gov (United States)

    2013-03-18

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Cold Cathode Fluorescent Lamp (``CCFL'') Inverter Circuits and Products Containing Same... importation, and the sale within the United States after importation of certain cold cathode fluorescent...

  11. Investigation on the effect of fluorescence quenching of bovine serum albumin by cefoxitin sodium using fluorescence spectroscopy and synchronous fluorescence spectroscopy.

    Science.gov (United States)

    Li, Gaixia; Liu, Bao-Sheng; Zhang, Qiuju; Han, Rong

    2016-08-01

    The reaction mechanism of cefoxitin sodium with bovine serum albumin was investigated using fluorescence spectroscopy and synchronous fluorescence spectroscopy at different temperatures. The results showed that the change of binding constant of the synchronous fluorescence method with increasing temperature could be used to estimate the types of quenching mechanisms of drugs with protein and was consistent with one of fluorescence quenching method. In addition, the number of binding sites, type of interaction force, cooperativity between drug and protein and energy-transfer parameters of cefoxitin sodium and bovine serum albumin obtained from two methods using the same equation were consistent. Electrostatic force played a major role in the conjugation reaction between bovine serum albumin and cefoxitin sodium, and the type of quenching was static quenching. The primary binding site for cefoxitin sodium was sub-hydrophobic domain IIA, and the number of binding sites was 1. The value of Hill's coefficients (nH ) was approximately equal to 1, which suggested no cooperativity in the bovine serum albumin-cefoxitin sodium system. The donor-to-acceptor distance r fluorescence quenching of bovine serum albumin by cefoxitin sodium was also a non-radiation energy-transfer process. The results indicated that synchronous fluorescence spectrometry could be used to study the reaction mechanism between drug and protein, and was a useful supplement to the conventional method. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Comparison of PCR/Electron Spray Ionization-Time-of-Flight-Mass Spectrometry versus Traditional Clinical Microbiology for Active Surveillance of Organisms Contaminating High-Use Surfaces in a Burn Intensive Care Unit, an Orthopedic Ward and Healthcare Workers

    Science.gov (United States)

    2012-10-10

    Enterobacter spp., Streptococcus spp. (68% viridans group), Pseudomonas aeruginosa, and Acinetobacter baumannii -calcoaceticus complex; the proportions of these...Staphylococcus aureus and Acinetobacter baumannii on computer interface surfaces of hospital wards and association with clinical isolates. BMC Infect Dis 2009, 9...Cursino MR, Sinto S: Environmental contamination by multidrug resistant Acinetobacter baumannii in an intensive care unit. Infect Control Hosp Epidemiol

  13. Introduction to fluorescence

    CERN Document Server

    Jameson, David M

    2014-01-01

    "An essential contribution to educating scientists in the principles of fluorescence. It will also be an important addition to the libraries of practitioners applying the principles of molecular fluorescence."-Ken Jacobson, Kenan Distinguished Professor of Cell Biology and Physiology, University of North Carolina at Chapel Hill"An exquisite compendium of fluorescence and its applications in biochemistry enriched by a very exciting historical perspective. This book will become a standard text for graduate students and other scientists."-Drs. Zygmunt (Karol) Gryczynski and Ignacy Gryczynski, University of North Texas Health Science Center"… truly a masterwork, combining clarity, precision, and good humor. The reader, novice or expert, will be pleased with the text and will not stop reading. It is a formidable account of the fluorescence field, which has impacted the life sciences so considerably in the last 60 years."-Jerson L. Silva, M.D., Ph.D., Professor and Director, National Institute of Science and Tech...

  14. Vibratory Reaction Unit for the Rapid Analysis of Proteins and Glycochains

    Directory of Open Access Journals (Sweden)

    Yukie Sasakura

    2007-01-01

    Full Text Available A protein digestion system using immobilized enzymes for protein identification and glycochain analyses has been developed, and a vibration reaction unit for micro-scale sample convection on an enzyme-immobilized solid surface was constructed. BSA as a model substrate was digested by this unit, and was successfully identified by mass spectrometry (MS analyses. Compared to the conventional liquid-phase digestion, the reaction unit increased the number of matched peptides from 9 to 26, protein score from 455 to 1247, and sequence coverage from 21% to 48%. Glycopeptidase F (NGF, an enzyme that cleaves N-glycans from glycoproteins, was also immobilized and used to remove the glycochains from human immunoglobulin G (IgG. Trypsin and NGF were immobilized on the same solid surface and used to remove glycochains from IgG in single-step. Glycochains were labeled with fluorescent reagent and analyzed by HPLC. Several peaks corresponding to the glycochains of IgG were detected. These results suggested that the single-step digestion system, by immobilized multiple enzymes (trypsin and NGF would be effective for the rapid structural analysis of glycoproteins.Abbreviations: BSA: bovine serum albumin; MS: mass spectrometry; NGF: glycopeptidase F; IgG: immunoglobulin G; PTM: post-translational modification; HPLC: high-performance liquid chromatography; PBS: phosphate-buffered saline; EDTA: ethylenediaminetetraacetic acid; DTT: dithiothreitol; RT: retention time; ABOE: p-aminobenzoic acid octyl ester; PDMS: polydimethylsiloxane; ArgC: endoprotease Arginine C.

  15. Functional Fluorescent Organic Nanoparticles

    OpenAIRE

    Campioli, Elisa

    2013-01-01

    This thesis presents an extensive study on fluorescent organic nanoparticles and fluorescent organic binary and ternary nanoassemblies. In particular the attention is focused on the preparation and characterization of organic nanoparticles and new nanocomposites obtained from different types of small organic molecules, their stabilization and the use of these materials for biological and optoelectronics applications. The work deals at the beginning with the description of some methods used...

  16. Hydrogen Exchange Mass Spectrometry.

    Science.gov (United States)

    Mayne, Leland

    2016-01-01

    Hydrogen exchange (HX) methods can reveal much about the structure, energetics, and dynamics of proteins. The addition of mass spectrometry (MS) to an earlier fragmentation-separation HX analysis now extends HX studies to larger proteins at high structural resolution and can provide information not available before. This chapter discusses experimental aspects of HX labeling, especially with respect to the use of MS and the analysis of MS data.

  17. 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

    2016-09-29

    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.

  18. Determination of Major and Minor Components in High-Cr Red Mud by X-ray Fluorescence Spectrometry with Fusion Sample Preparation%熔融制样X射线荧光光谱法测定高铬赤泥中主次量组分

    Institute of Scientific and Technical Information of China (English)

    朱忠平; 曾精华; 王长根; 吕立超

    2014-01-01

    be analyzed by X-ray Fluorescence Spectrometry (XRF).However,a use of sodium flux and a high dilution ratio are not conducive to sodium and low content elements.In this paper,a method of XRF analysis is developed for the determination of the major and minor components (Cr,Si,Al,Fe,Mg,Ca,Na,K,S,P,Ti,Mn and V)in high-Cr red mud by fused bead preparation with Li2B4O7-LiBO2(67∶33)flux,NH4NO3 oxidizer and saturated LiBr solution parting medium.When the dilution ratio of the melting sample is lower than 24∶1 ,the lower dilution ratio,the more serious is the corrosion on the Pt-Au crucible;the RSD (n=1 0)of the sample preparation method is at a minimum when the dilution ratio is 24∶1;the longer the melting time and the higher the melting temperature,the RSD becomes lower.The optimization conditions of fused bead are obtained when the dilution ratio is 24∶1 ,the melting temperature is 1 1 00℃ and the melting time is 1 5 min.The working curve was established by chromite,bauxite,clay,iron ore standards and manual preparation standard materials.The matrix effect and spectrum line overlap interference were corrected by a fundamental parameter method and standard regression.The results are consistent with certified values and the RSD (n=10)is from 0.3% to 3.9%.Compared with domestic and foreign XRF methods for chromium-containing minerals,this method uses no sodium salt,a fuse piece,conventional sample melting temperature (1 1 00℃),low dilution ratio (24 ∶1 )for sample preparation,and the sampling precision and analysis precision are low.The problem with XRF analysis of high-Cr red mud has been solved by this method,which can be used to analyze Cr,Al, Si and Fe in roasting,concentrates and tailings and other ores processed by sodium.

  19. Fluorescent halite from Bochnia salt mine, Poland

    Science.gov (United States)

    Waluś, Edyta; Głąbińska, Dobrochna; Puławska, Aleksandra; Flasza, Michał; Manecki, Maciej

    2016-04-01

    The photoluminescence of selected halite crystals from Bochnia Salt Mine (Bochnia, Poland) were discovered in 2014. This is a result of contemporary precipitation from percolating waters. In most cases the fluorescence is observed in whole crystals or in zones of crystals. Only clear parts of transparent crystals are orange-red fluorescent in short UV light (320 nm). Chemical microanalysis by scanning electron microscopy/energy dispersive spectroscopy SEM/EDS indicates that this is activated by Mn and Pb. The concentration of Mn is similar in fluorescent and inactive salt and equals to 0.13 - 0.27 wt.%. The concentration of Pb, however, averages to 3.8 wt.% in fluorescent parts reaching only 1.9 wt.% elsewhere. There is no difference in the unit cell parameters determined by powder X-ray diffraction. The percolating waters contain some Mn (ca. 3.9 ppm) but the concentration of Pb is below the detection limits. The experiments of precipitation of halite from the solutions containing various concentrations of Mn and Pb were performed to simulate this fenomenon using solutions containing: 1 mg Pb/L and 80 mg Mn/L; 1 mg Pb/L and 0.8 mg Mn/L; 1 mg Pb/L and 0.6 mg Mn/L; and 0 mg Pb/L and 80 mg Mn/L. The results indicate that fluorescence is apparent when halite forms from solutions containing more than 0.8 mg Mn/L and more than 1 mg Pb/L. The presence of lead as co-activator is necessary requirement: Mn alone does not activate the fluorescence of halite. This is in accordance with the results of previous work (Murata et al., 1946; Sidike et al., 2002). Rock salt in the mine does not show fluorescence at all. Fluorescence of contemporary salt in Bochnia salt mine is a result of mining activity and slight, sporadic contamination with traces of Mn and Pb. This work is partially funded by AGH research grant no 11.11.140.319. Murata K. J., Smith R. L., 1946. Manganese and lead as coactivators of red fluorescence in halite, American Mineralogist, Volume 31, pages 527

  20. Mass spectrometry imaging: applications to food science.

    Science.gov (United States)

    Taira, Shu; Uematsu, Kohei; Kaneko, Daisaku; Katano, Hajime

    2014-01-01

    Two-dimensional mass spectrometry (MS) analysis of biological samples by means of what is called MS imaging (MSI) is now being used to analyze analyte distribution because it facilitates determination of the existence (what is it?) and localization (where is it?) of biomolecules. Reconstruction of mass image by target signal is given after two-dimensional MS measurements on a sample section. From only one section, we can understand the existence and localization of many molecules without the need of an antibody or fluorescent reagent. In this review, we introduce the analysis of localization of functional constituents and nutrients in herbal medicine products via MSI. The ginsenosides were mainly distributed in the periderm and the tip region of the root of Panax ginseng. The capsaicin was found to be more dominantly localized in the placenta than the pericarp and seed in Capsicum fruits. We expect MSI will be a useful technique for optical quality assurance.

  1. Fluorescent Bioactive Corrole Grafted-Chitosan Films.

    Science.gov (United States)

    Barata, Joana F B; Pinto, Ricardo J B; Vaz Serra, Vanda I R C; Silvestre, Armando J D; Trindade, Tito; Neves, Maria Graça P M S; Cavaleiro, José A S; Daina, Sara; Sadocco, Patrizia; Freire, Carmen S R

    2016-04-11

    Transparent corrole grafted-chitosan films were prepared by chemical modification of chitosan with a corrole macrocycle, namely, 5,10,15-tris(pentafluorophenyl)corrole (TPFC), followed by solvent casting. The obtained films were characterized in terms of absorption spectra (UV-vis), FLIM (fluorescence lifetime imaging microscopy), structure (FTIR, XPS), thermal stability (TGA), thermomechanical properties (DMA), and antibacterial activity. The results showed that the chemical grafting of chitosan with corrole units did not affect its film-forming ability and that the grafting yield increased with the reaction time. The obtained transparent films presented fluorescence which increases with the amount of grafted corrole units. Additionally, all films showed bacteriostatic effect against S. aureus, as well as good thermomechanical properties and thermal stability. Considering these features, promising applications may be envisaged for these corrole-chitosan films, such as biosensors, bioimaging agents, and bioactive optical devices.

  2. X-Ray fluorescence analysis of trace elements in fruit juice

    Science.gov (United States)

    Bao, Sheng-Xiang; Wang, Zhi-Hong; Liu, Jing-Song

    1999-12-01

    X-Ray fluorescence spectrometry is applied to the determination of trace elements in fruit juice characterized by a high content of sugar and other soluble solid substances. Samples are prepared by evaporation, carbonization and pressing into discs. The synthesis of standards is described in detail. All element concentrations are directly estimated from linear calibration curves obtained without any matrix correction. The results of the analysis are in good agreement with those given by inductively coupled plasma-atomic emission spectrometry and atomic absorption spectrometry techniques.

  3. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  4. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  5. 熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷%Determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese,copper and phosphorus in laterite nickel ores by wavelength dispersive X-ray fluorescence spectrometry with fusion sample preparation

    Institute of Scientific and Technical Information of China (English)

    林忠; 李卫刚; 褚宁; 蒋晓光; 孙涛; 林志伟; 王艳君

    2012-01-01

    A wavelength dispersive X - ray fluorescence spectrometry with fusion sample preparation has been developed for determination of iron, nickel, silicon, aluminum, magnesium, calcium, titanium, manganese, copper and phosphorus in laterite nickel ores. Calibration samples were prepared by adding high pure oxides and standard solutions of pending elements into iron ore standards, which were applied as matrix and ignited in 1000 ℃. The experimental conditions including of fluxing agent, fusion time, dilution ratios, doffing membrane reagent and matrix effects were determined. The analytical results were proposed by loss on ignition calibration, which were agreement with those obtained by wet method analysis, and the relative standard deviation was between 0. 219 % and 2. 817 %. The method was satisfied the request of laterite nickel ores test.%建立了熔融制样-波长色散X射线荧光光谱法测定红土镍矿中铁、镍、硅、铝、镁、钙、钛、锰、铜和磷含量的方法.采用经1000℃灼烧后的铁矿标准样品为基体,添加相关待测元素的高纯氧化物和标准溶液制作校准曲线用的校准样品,确定了助熔剂、熔融时间、稀释比、脱模剂和基体效应校正方式等试验条件.样品分析结果进行烧失量校正,与湿法分析结果的相对标准偏差介于0.219%~2.817%之间,满足红土镍矿检测需要.

  6. Determination of P, K, Ca, Mg, Mn, Fe, Cu, Na, Zn and Al in compound fertilizers by X-ray fluorescence spectrometry with fused glass disc sample preparation%熔融制样-X射线荧光光谱法快速测定复合肥中的磷、钾、钙、镁、锰、铁、铜、钠、锌和铝

    Institute of Scientific and Technical Information of China (English)

    任春生; 廖海平; 鲍惠君; 朱迪琦; 何阳

    2011-01-01

    为实现复合肥样品中多元素的同时分析,采用熔融片法制样,有效地消除了试样的粒度效应,用X射线荧光光谱法测定复合肥样品中磷、钾、钙、镁、锰、铁、铜、钠、锌和铝10个元素,对仪器工作条件进行了试验并选定最佳条件,使各元素测定所要求的灵敏度和准确度得到满足,以8个合成的样品作为校准样品,采用固定理论α影响系数进行回归及基体效应校正,方法精密度(RSD,n=8)≤1.36%,分析结果与化学法进行对照基本一致.%A method for the determination of including P, K, Ca, Mg, Mn, Fe, Cu, Na, Zn and Al in compound fertilizers by X-ray fluorescence spectrometry with fused glass disc sample preparation was reported in this paper.The granularity effect in the analysis was eliminated by the fusion method of sam pie-dissolution.The working conditions of the instrument were also studied and optimized to meet with the requirements of sensitivity and accuracy of determination.Eight composed samples were used as the calibration standards.The matrix effect was corrected with fixed theoretical alpha coefficient method.The precision of the method was RSD≤1.36% (n =8).The results were in agreement with those by chemical methods.

  7. Highly Efficient and Exceptionally Durable CO2 Photoreduction to Methanol over Freestanding Defective Single-Unit-Cell Bismuth Vanadate Layers.

    Science.gov (United States)

    Gao, Shan; Gu, Bingchuan; Jiao, Xingchen; Sun, Yongfu; Zu, Xiaolong; Yang, Fan; Zhu, Wenguang; Wang, Chengming; Feng, Zimou; Ye, Bangjiao; Xie, Yi

    2017-03-08

    Unearthing an ideal model for disclosing the role of defect sites in solar CO2 reduction remains a great challenge. Here, freestanding gram-scale single-unit-cell o-BiVO4 layers are successfully synthesized for the first time. Positron annihilation spectrometry and X-ray fluorescence unveil their distinct vanadium vacancy concentrations. Density functional calculations reveal that the introduction of vanadium vacancies brings a new defect level and higher hole concentration near Fermi level, resulting in increased photoabsorption and superior electronic conductivity. The higher surface photovoltage intensity of single-unit-cell o-BiVO4 layers with rich vanadium vacancies ensures their higher carriers separation efficiency, further confirmed by the increased carriers lifetime from 74.5 to 143.6 ns revealed by time-resolved fluorescence emission decay spectra. As a result, single-unit-cell o-BiVO4 layers with rich vanadium vacancies exhibit a high methanol formation rate up to 398.3 μmol g(-1) h(-1) and an apparent quantum efficiency of 5.96% at 350 nm, much larger than that of single-unit-cell o-BiVO4 layers with poor vanadium vacancies, and also the former's catalytic activity proceeds without deactivation even after 96 h. This highly efficient and spectrally stable CO2 photoconversion performances hold great promise for practical implementation of solar fuel production.

  8. Stroboscopic fluorescence lifetime imaging.

    Science.gov (United States)

    Holton, Mark D; Silvestre, Oscar R; Errington, Rachel J; Smith, Paul J; Matthews, Daniel R; Rees, Paul; Summers, Huw D

    2009-03-30

    We report a fluorescence lifetime imaging technique that uses the time integrated response to a periodic optical excitation, eliminating the need for time resolution in detection. A Dirac pulse train of variable period is used to probe the frequency response of the total fluorescence per pulse leading to a frequency roll-off that is dependent on the relaxation rate of the fluorophores. The technique is validated by demonstrating wide-field, realtime, lifetime imaging of the endocytosis of inorganic quantum dots by a cancer cell line. Surface charging of the dots in the intra-cellular environment produces a switch in the fluorescence lifetime from approximately 40 ns to technique offers lifetime based imaging at video rates with standard CCD cameras and has application in probing millisecond cell dynamics and in high throughput imaging assays.

  9. Fluorescence behaviour and dural infiltration of meningioma analyzed by 5-ALA based fluorescence: Operating microscope versus mini-spectrometer.

    Science.gov (United States)

    Knipps, Johannes; Beseoglu, Kerim; Kamp, Marcel; Fischer, Igor; Felsberg, Joerg; Neumann, Lisa M; Steiger, Hans-Jakob; Cornelius, Jan F

    2017-08-30

    To compare fluorescence intensity of tumor specimens as measured by a FGS-microscope and a spectrometer, 2.) to evaluate tumor infiltration of dura mater around meningiomas with help of these two different 5-ALA based fluorescence tools and 3.) to correlate fluorescence intensity with histopathological data. In a clinical series menigiomas were resected by 5-ALA fluorescence guided surgery. Fluorescence intensity was semi-quantitatively rated by the surgeon at pre-defined points. Biopsies were harvested and fluorescence intensity measured by a spectrometer and histopathologically analysed. Sampling was realized at the level of the dura in a centrifugal direction. 104 biopsies (n= 13 tumors) were analysed. Specificity and sensitivity of the microscope were 0.96 and 0.53 and of the spectrometer 0.95 and 0.93, respectively. Fluorescence intensity as measured by the spectrometer was correlated to histologically confirmed tumor burden. In a centrifugal direction, tumor burden and fluorescence intensity continuously decreased (along the dural tail). Below a threshold value of 639 arbitrary units no tumor was histologically detectable. At the level of the dura the spectrometer was highly sensitive for detection of meningioma cells. The surgical microscope showed false negative results and missed residual tumor cells in more than half of the cases. The complementary use of both fluorescence tools may improve resection quality. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Nanosecond fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Leskovar, B.

    1985-03-01

    This article is a summary of a short course lecture given in conjunction with the 1984 Nuclear Science Symposium. Measuring systems for nanosecond fluorescence spectroscopy using single-photon counting techniques are presented. These involve systems based on relaxation-type spark gap light pulser and synchronously pumped mode-locked dye lasers. Furthermore, typical characteristics and optimization of operating conditions of the critical components responsible for the system time resolution are discussed. A short comparison of the most important deconvolution methods for numerical analysis of experimental data is given particularly with respect to the signal-to-noise ratio of the fluorescence signal. 22 refs., 8 figs.

  11. Photosynthetic membrane development studied using picosecond fluorescence kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Karukstis, K.K.; Sauer, K.

    1983-01-01

    Using measurements of the kinetics of chlorophyll a fluorescence emission, the development of the photosynthetic membrane during etioplast-to-chloroplast differentiation was investigated. Tthe chlorophyll fluorescence decay kinetics of pea chloroplasts from plants grown under intermittent (2 min light-118 min dark) and continuous light regimes were monitored with a single-proton timing system with picosecond resolution. The changes in the fluorescence yields and decay kinetics were associated with known structural and organizational developmental phenomena in the chloroplast. This correlation provides a more detailed assignment of the origins of the fluorescence decay components than has been previously obtained by studying only mature chloroplasts. In particular, the analysis of the variable kinetics and multiexponential character of the fluorescence emission during thylakoid development focuses on the organization of photosynthetic units and the degree of communication between reaction centers in the same photosystem. These results further demonstrate that the age of etiolated tissue is critical to plastid development.

  12. Refractometric Sensing of Heavy Oils in Fluorescent Core Microcapillaries

    Directory of Open Access Journals (Sweden)

    Zamora V.

    2015-03-01

    Full Text Available The refractometric sensing of calibrated heavy oils (density > 1 000 kg/m3 is demonstrated using fluorescent-core microcapillaries. A 25-micron capillary channel was first coated with a high-index layer of fluorescent silicon Quantum Dots (QD. This QD film supports the development of cylindrical Whispering Gallery Mode (WGM resonances inside the capillary. Heavy oils spanning a wide range of refractive index were pumped into the capillary channel, causing large shifts in the fluorescence WGM resonant wavelengths. The sensitivity for heavy oils approached 250 nm per Refractive Index Unit (nm/RIU at the higher oil indices, which is the highest sensitivity so far observed for a refractometric sensor operating in the fluorescence mode. This suggests that fluorescent core microcapillaries may be a viable microfluidic alternative for refractometric or chemical sensing in various stages of oil and gas processing, monitoring and usage.

  13. Integrated optical measurement system for fluorescence spectroscopy in microfluidic channels

    DEFF Research Database (Denmark)

    Hübner, Jörg; Mogensen, Klaus Bo; Jørgensen, Anders Michael

    2001-01-01

    A transportable miniaturized fiber-pigtailed measurement system is presented which allows quantitative fluorescence detection in microliquid handling systems. The microliquid handling chips are made in silica on silicon technology and the optical functionality is monolithically integrated...... with the microfluidic channel system. This results in inherent stability and photolithographic alignment precision. Permanently attached optical fibers provide a rugged connection to the light source, detection, and data processing unit, which potentially allows field use of such systems. Fluorescence measurements...

  14. Fluorescence Experiments with Quinine

    Science.gov (United States)

    O'Reilly, James E.

    1975-01-01

    Describes a series of experiments which illustrate the analytical capabilities of fluorescence, and outlines two straightforward analyses involving real analyses. These experiments are suitable for an undergraduate instrumental analysis course and require approximately six to seven hours of laboratory time. (MLH)

  15. FLEX: fluorescence explorer

    NARCIS (Netherlands)

    Stoll, M.Ph.; Court, A.J.; Smorenburg, C.; Visser, H.; Crocco, L.; Heilimo, J.; Honig, A.

    1999-01-01

    FLEX is a scientifically driven space mission to provide demonstration/validation of the instrumentation and technique for measuring the natural fluorescence of vegetation in the Fraunhofer lines. The payload consists of high spectral resolution (0.1-0.3 nm) CCD imaging grating spectrometer with two

  16. A Novel Molecular Fluorescent Technique for Imaging the Somatostatin Receptor 2, Using a DOTATOC Lanthanide Conjugate

    DEFF Research Database (Denmark)

    Andersen, Rune Wiik; Prakash, Vineet; Stensballe, Allan

    to easily obtain commercial receptor antibodies. We propose an alternative with the novel use of lanthanide fluorescent DOTATOC imaging.Purpose is to prove that it is feasible to combine the fluorescent nuclear imaging of neuroendocrine tumors with histopathological correlates using the same bio......-functional DOTATOC component.                       METHOD AND MATERIALS            The chelation of Europium and Samarium to DOTATOC was proven using MALDI-TOF Mass Spectrometry. The rise in quantum yield between unchelated lanthanides and those bound by DOTATOC was examined using fluorescence spectroscopy...

  17. "Magic" Ionization Mass Spectrometry

    Science.gov (United States)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  18. Physically-based in silico light sheet microscopy for visualizing fluorescent brain models.

    Science.gov (United States)

    Abdellah, Marwan; Bilgili, Ahmet; Eilemann, Stefan; Markram, Henry; Schürmann, Felix

    2015-01-01

    We present a physically-based computational model of the light sheet fluorescence microscope (LSFM). Based on Monte Carlo ray tracing and geometric optics, our method simulates the operational aspects and image formation process of the LSFM. This simulated, in silico LSFM creates synthetic images of digital fluorescent specimens that can resemble those generated by a real LSFM, as opposed to established visualization methods producing visually-plausible images. We also propose an accurate fluorescence rendering model which takes into account the intrinsic characteristics of fluorescent dyes to simulate the light interaction with fluorescent biological specimen. We demonstrate first results of our visualization pipeline to a simplified brain tissue model reconstructed from the somatosensory cortex of a young rat. The modeling aspects of the LSFM units are qualitatively analysed, and the results of the fluorescence model were quantitatively validated against the fluorescence brightness equation and characteristic emission spectra of different fluorescent dyes. Modelling and simulation.

  19. Determination of experimental conditions for the analysis of rare-earth elements by X-ray fluorescence spectrometry. Application to oxalates and potassium sulphate matrices; Establecimiento de varibles experimentales para la determinacion de tierras raras por espectrometria de fluorescencia de rayos X. Aplicacion a los concentrados de oxalatos y sulfatos

    Energy Technology Data Exchange (ETDEWEB)

    Bayon Fuentes, A.; Bermudez Polonio, J.

    1969-07-01

    A previous theoretical and experimental study is carried out in order to analyze the rare earths elements by X-ray florescence spectrometry. All possible spectral interferences are considered. The working conditions for each element were selected, taking into account the peak/background ratio values for the following parameters: tungsten, molybdenum and chromium targets, current and voltage, analyzing crystals, and scintillation and flow proportional counters. Calibration curves were plotted showing the concentration of rare earths elements in oxalates and potassium sulphate matrices, and the theoretical detection limits for each element: are calculated. (Author) 8 refs.

  20. International Mass Spectrometry Society (IMSS).

    Science.gov (United States)

    Cooks, R G; Gelpi, E; Nibbering, N M

    2001-02-01

    This paper gives a brief description of the recently formalized International Mass Spectrometry Society (IMSS). It is presented here in order to increase awareness of the opportunities for collaboration in mass spectrometry in an international context. It also describes the recent 15th International Mass Spectrometry Conference, held August/September 2000, in Barcelona. Each of the authors is associated with the IMSS. The 15th Conference, which covers all of mass spectrometry on a triennial basis, was chaired by Professor Emilio Gelpi of the Instituto de Investigaciones Biomedicas, Barcelona. The outgoing and founding President of the IMSS is Professor Graham Cooks, Purdue University, and the incoming President is Professor Nico Nibbering, University of Amsterdam. Similar material has been provided to the Editors of other journals that cover mass spectrometry.

  1. Synthesis and Fluorescence Spectra of Triazolylcoumarin Fluorescent Dyes

    Institute of Scientific and Technical Information of China (English)

    PENG Xian-fu; LI Hong-qi

    2009-01-01

    Much attention is devoted to fluorescent dyes especially those with potential in versatile applications. Reactions under "click" conditions between nonfluorescent 3 - azidocoumarins and terminal alkynes produced 3 -(1, 2, 3- triazol- 1 - yl)cournarins, a novel type of fluorescent dyes with intense fluorescence. The structures of the new coumarins were characterized by 1H NMR, MS, and IR spectra. Fluorescence spectra measurement demonstrated excellent fluorescence performance of the triazolylcoumarins and this click reaction is a promising candidate for bioconjugation and bioimaging applications since both azide and alkynes are quite inert to biological systems.

  2. Fluorescence nanoscopy. Methods and applications

    OpenAIRE

    Requejo-Isidro, Jose

    2013-01-01

    Fluorescence nanoscopy refers to the experimental techniques and analytical methods used for fluorescence imaging at a resolution higher than conventional, diffraction-limited, microscopy. This review explains the concepts behind fluorescence nanoscopy and focuses on the latest and promising developments in acquisition techniques, labelling strategies to obtain highly detailed super-resolved images and in the quantitative methods to extract meaningful information from them.

  3. Mercury mass measurement in fluorescent lamps via neutron activation analysis

    Science.gov (United States)

    Viererbl, L.; Vinš, M.; Lahodová, Z.; Fuksa, A.; Kučera, J.; Koleška, M.; Voljanskij, A.

    2015-11-01

    Mercury is an essential component of fluorescent lamps. Not all fluorescent lamps are recycled, resulting in contamination of the environment with toxic mercury, making measurement of the mercury mass used in fluorescent lamps important. Mercury mass measurement of lamps via instrumental neutron activation analysis (NAA) was tested under various conditions in the LVR-15 research reactor. Fluorescent lamps were irradiated in different positions in vertical irradiation channels and a horizontal channel in neutron fields with total fluence rates from 3×108 cm-2 s-1 to 1014 cm-2 s-1. The 202Hg(n,γ)203Hg nuclear reaction was used for mercury mass evaluation. Activities of 203Hg and others induced radionuclides were measured via gamma spectrometry with an HPGe detector at various times after irradiation. Standards containing an Hg2Cl2 compound were used to determine mercury mass. Problems arise from the presence of elements with a large effective cross section in luminescent material (europium, antimony and gadolinium) and glass (boron). The paper describes optimization of the NAA procedure in the LVR-15 research reactor with particular attention to influence of neutron self-absorption in fluorescent lamps.

  4. Delayed fluorescence in photosynthesis.

    Science.gov (United States)

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  5. Red fluorescence in reef fish: A novel signalling mechanism?

    Directory of Open Access Journals (Sweden)

    Siebeck Ulrike E

    2008-09-01

    Full Text Available Abstract Background At depths below 10 m, reefs are dominated by blue-green light because seawater selectively absorbs the longer, 'red' wavelengths beyond 600 nm from the downwelling sunlight. Consequently, the visual pigments of many reef fish are matched to shorter wavelengths, which are transmitted better by water. Combining the typically poor long-wavelength sensitivity of fish eyes with the presumed lack of ambient red light, red light is currently considered irrelevant for reef fish. However, previous studies ignore the fact that several marine organisms, including deep sea fish, produce their own red luminescence and are capable of seeing it. Results We here report that at least 32 reef fishes from 16 genera and 5 families show pronounced red fluorescence under natural, daytime conditions at depths where downwelling red light is virtually absent. Fluorescence was confirmed by extensive spectrometry in the laboratory. In most cases peak emission was around 600 nm and fluorescence was associated with guanine crystals, which thus far were known for their light reflecting properties only. Our data indicate that red fluorescence may function in a context of intraspecific communication. Fluorescence patterns were typically associated with the eyes or the head, varying substantially even between species of the same genus. Moreover red fluorescence was particularly strong in fins that are involved in intraspecific signalling. Finally, microspectrometry in one fluorescent goby, Eviota pellucida, showed a long-wave sensitivity that overlapped with its own red fluorescence, indicating that this species is capable of seeing its own fluorescence. Conclusion We show that red fluorescence is widespread among marine fishes. Many features indicate that it is used as a private communication mechanism in small, benthic, pair- or group-living fishes. Many of these species show quite cryptic colouration in other parts of the visible spectrum. High inter

  6. A New Method for Determination of Arsenic and Mercury in Copper Concentrates: By High pressure airproof Microwave Digestion,Sequential Injection,Hydride Generation,and Atomic Fluorescence Spectrometry%一种检测铜精矿中砷和汞含量的新方法——高压密封微波消解-顺序注射-氢化物发生-原子荧光光谱法

    Institute of Scientific and Technical Information of China (English)

    苏明跃; 杨丽飞; 郭芬

    2011-01-01

    利用高压密封微波消解和顺序注射-氢化物发生-原子荧光光谱两项技术建立了检测铜精矿中砷、汞含量的新方法,并通过试验确定了适宜的检测条件.研究结果表明:本方法对砷的检出限为0.02μg/L,对汞的检出限为0.05μg/L;检测铜精矿中砷、汞的含量时,砷、汞的回收率分别为94.3%~107.0%和91.0%~102.0%,检测结果相对标准偏差分别在0.93%~1.97%之间和3.11%~8.07%之间,并且检测结果与认定值和国家标准方法测定值一致.%A new method for the determinations of arsenic content and mercury content in copper concentrates was founded by adopting two processes of high pressure-airproof microwave digestion and the sequential injection-hydride generation -atomic fluorescence spectrometry. Through tests, the optimum conditions for detection were determined. The tests resuits indicated that the detection limit of arsenic was 0.02 μg/L and the detection limit of mercury was 0.05 μg/L by this method. While detecting arsenic and mercury content in copper concentrate, it is found that the arsenic and mercury recovery rates reached 94.3% ~ 107.0% and 91.0% ~ 102.0% respectively with relative standard of deviation between 0.93% ~1.97% for arsenic and 3.11% ~ 8.07% for mercury. Also, these detecting results are in good agreement with the certified values and the values by the national standard method.

  7. 粉末压片制样-波长色散X射线荧光光谱法测定斑岩型钼铜矿中主次量元素钼铜铅锌砷镍硫%Determination of Major and Minor Elements of Mo, Cu, Pb, Zn, As, Ni and S in the Porphyry Type Lindgrenite by Wavelength Dispersive X-ray Fluorescence Spectrometry with Pressed-powder Pellets

    Institute of Scientific and Technical Information of China (English)

    夏鹏超; 李明礼; 王祝; 李代琼; 胡亚燕

    2012-01-01

    A method has been developed for the determination of Mo, Cu, Pb, Zn, Ni, As and S in porphyry type lindgrenite from Tibet by Wavelength Dispersive X-ray Fluorescence Spectrometry with pressed powder pellets. The national standard reference materials of molybdenum ore and copper ore, as well as self-synthesized reference materials were used to build the working curve. Using Compton correction as the internal standard, the matrix effect and particle size effect was corrected by empirical coefficients. According to the verification by the national standard reference materials and self-synthesized reference materials, the analytical results were in good agreement with certified values. The relative standard deviation RSD (n = 12) of this method was less than 2. 18% for all of the elements. Compared with classical chemical methods, this method was simple, fast and highly accurate and provided precision without chemical pretreatment. It is suitable for practical determination of lindgrenite samples. Seven calibration samples were synthesized by the national standard reference materials which solved the problem of lack of calibration samples.%采用粉末压片制样,波长色散X射线荧光光谱法测定西藏某斑岩型钼铜矿中7个主次量元素Mo、Cu、Pb、Zn、As、Ni、S.选择钼矿石、铜矿石国家标准物质及自配标准物质建立工作曲线,使用康普顿散射线作内标,同时采用经验系数法校正基体效应及粒度效应.方法经国家标准物质、自配标准参考物质验证,测定值与标准值吻合,方法分析精密度(RSD,n=12)小于2.18%,与化学法相比,样品不需进行化学前处理,操作简单、快速、准确度高、精密度好,能满足钼铜矿的实际分析需要.利用国家标准物质配制合成了7个校准标准样品,有效地解决了方法建立过程中标准样品种类和数量不足的问题.

  8. Diagnosis of Dentin Caries – Ultraviolet Fluorescence

    Directory of Open Access Journals (Sweden)

    Uzunov Ts.

    2014-12-01

    Full Text Available The technology advance in recent years determines the need of construction of modern appliances for early diagnosis of dental caries, which are categorized by great precision, non-invasiveness, easy usage and wide availability. Such non-invasive and accurate tool for diagnostics of caries is Caries Detector (LED, Bulgarian product by “Optica Laser”. The detector emits a specific wavelength of near ultraviolet light, which causes fluorescence to porphyrins - metabolic products of the life cycle of caries-inducing bacteria. The purpose of the study is piloting a new diagnostic tool for detection and monitoring of caries excavation based on fluorescence - LED UV caries detector of company “Optica laser”. Subjected to examination by caries indicator dye and UV caries detector were sixty permanent teeth with deep dentine caries. Two methods were used to assess the dentin caries - UV fluorescence detector of “Optica Laser” and staining with caries indicator - dye (Sable ™ Seek®. It was found that among all sixty teeth, the fields, closed by margins of carious process overlap. Fifty-four of tested teeth has shown bigger field of images with staining method and six - smaller in comparison to the fluorescent method. Ultraviolet fLuorescence caries detector of “Optica Laser” company is affordable and easy applicable method for controlled excavation of dentine caries. The detector can be used in daily dental practice equally with other methods. The unit has a number of advantages - non-invasiveness, lack of interaction with tooth structures, speed, reliability, efficiency, predictability and repeatability of results.

  9. [Effect of quantum dots CdSe/ZnS's concentration on its fluorescence].

    Science.gov (United States)

    Jin, Min; Huang, Yu-hua; Luo, Ji-xiang

    2015-02-01

    The authors measured the absorption and the fluorescence spectra of the quantum dots CdSe/ZnS with 4 nm in size at different concentration with the use of the UV-Vis absorption spectroscopy and fluorescence spectrometer. The effect of quantum dots CdSe/ZnS's concentration on its fluorescence was especially studied and its physical mechanism was analyzed. It was observed that the optimal concentration of the quantum dots CdSe/ZnS for fluorescence is 2 micromole x L(-1). When the quantum dot's concentration is over 2 micromol x L(-1), the fluorescence is decreased with the increase in the concentration. While the quantum dot's concentration is less than 2 micromol x L(-1), the fluorescence is decreased with the decrease in the concentration. There are two main reasons: (1) fluorescence quenching and 2) the competition between absorption and fluorescence. When the quantum dot's concentration is over 2 micromol x L(-1), the distance between quantum dots is so close that the fluorescence quenching is induced. The closer the distance between quantum dots is, the more serious the fluorescence quenching is induced. Also, in this case, the absorption is so large that some of the quantum dots can not be excited because the incident light can not pass through the whole sample. As a result, the fluorescence is decreased with the increase in the quantum dot's concentration. As the quantum dot's concentration is below 2 micromol x L(-1), the distance between quantum dots is far enough that no more fluorescence quenching is induced. In this case, the fluorescence is determined by the particle number per unit volume. More particle number per unit volume produces more fluorescence. Therefore, the fluorescence is decreased with the decrease in the quantum dot's concentration.

  10. Optical filters for wavelength selection in fluorescence instrumentation.

    Science.gov (United States)

    Erdogan, Turan

    2011-04-01

    Fluorescence imaging and analysis techniques have become ubiquitous in life science research, and they are poised to play an equally vital role in in vitro diagnostics (IVD) in the future. Optical filters are crucial for nearly all fluorescence microscopes and instruments, not only to provide the obvious function of spectral control, but also to ensure the highest possible detection sensitivity and imaging resolution. Filters make it possible for the sample to "see" light within only the absorption band, and the detector to "see" light within only the emission band. Without filters, the detector would not be able to distinguish the desired fluorescence from scattered excitation light and autofluorescence from the sample, substrate, and other optics in the system. Today the vast majority of fluorescence instruments, including the widely popular fluorescence microscope, use thin-film interference filters to control the spectra of the excitation and emission light. Hence, this unit emphasizes thin-film filters. After briefly introducing different types of thin-film filters and how they are made, the unit describes in detail different optical filter configurations in fluorescence instruments, including both single-color and multicolor imaging systems. Several key properties of thin-film filters, which can significantly affect optical system performance, are then described. In the final section, tunable optical filters are also addressed in a relative comparison.

  11. 75 FR 36119 - In the Matter of Certain Cold Cathode Fluorescent Lamp (“CCFL”) Inverter Circuits and Products...

    Science.gov (United States)

    2010-06-24

    ... COMMISSION In the Matter of Certain Cold Cathode Fluorescent Lamp (``CCFL'') Inverter Circuits and Products... United States after importation of certain cold cathode fluorescent lamp inverter circuits and products..., and the sale within the United States after importation of CCFL inverter circuits and...

  12. Mass Spectrometry of Halopyrazolium Salts

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Pande, U. C.;

    1983-01-01

    Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry. Dealkylation was found to be the predominant thermal decomposition. An exchange between covalent and ionic halogen prior...

  13. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  14. Methods for Neutron Spectrometry

    Science.gov (United States)

    Brockhouse, Bertram N.

    1961-01-09

    The appropriate theories and the general philosophy of methods of measurement and treatment of data neutron spectrometry are discussed. Methods of analysis of results for liquids using the Van Hove formulation, and for crystals using the Born-von Karman theory, are reviewed. The most useful of the available methods of measurement are considered to be the crystal spectrometer methods and the pulsed monoenergetic beam/time-of-flight method. Pulsed-beam spectrometers have the advantage of higher counting rates than crystal spectrometers, especially in view of the fact that simultaneous measurements in several counters at different angles of scattering are possible in pulsed-beam spectrometers. The crystal spectrometer permits several valuable new types of specialized experiments to be performed, especially energy distribution measurements at constant momentum transfer. The Chalk River triple-axis crystal-spectrometer is discussed, with reference to its use in making the specialized experiments. The Chalk River rotating crystal (pulsed-beam) spectrometer is described, and a comparison of this type instrument with other pulsed-beam spectrometers is made. A partial outline of the theory of operation of rotating-crystal spectrometers is presented. The use of quartz-crystal filters for fast neutron elimination and for order elimination is discussed. (auth)

  15. Biomedical accelerator mass spectrometry

    Science.gov (United States)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  16. Synthesis and Spectroscopic Investigation of Diketopyrrolopyrrole - Spiropyran Dyad for Fluorescent Switch Application.

    Science.gov (United States)

    Doddi, Siva; Narayanaswamy, K; Ramakrishna, Bheerappagari; Singh, Surya Prakash; Bangal, Prakriti Ranjan

    2016-11-01

    We report the synthesis and characterization of a new fluorescent dyad SP-DPP-SP(9) via efficient palladium-catalyzed Sonogashira coupling of prop-2-yn-1-yl 3-(3',3'dimethyl-6-nitrospiro[chromene-2,2'-indolin]-1'-yl)propanoatespiropyran, SP(8), a well known photochromic accepter, with 3,6-bis(5-bromothiophen-2-yl)-2,5-bis((R)-2-ethylhexyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione, DPP(4), a highly fluorescent donor. Under visible light exposure the SP unit is in a closed hydrophobic form, whereas under UV irradiation it converts to a polar, hydrophilic open form named Merocyanine (MC), which is responsible for functioning of photo-switch application. The photochemistry pertaining to fluorescence switch, 'on/off' behaviour, of model dyad SP-DPP-SP(9) is experimentally analyzed in solution as well as in solid state in polymer matrices by photoluminescence(PL) and absorption spectroscopy. After absorption of UV light the spiropyran unit of the dyad under goes the rupture of the spiro C-O bond leading to the formation of MC. The absorption band of MC fairly overlaps to the fluorescence of DPP unit resulting quenching of fluorescence via fluorescence resonance energy transfer from exited DPP unit to ground state MC. In contrary, the fluorescence of DPP is fully regained upon transformation of MC to SP by exposure to visible light or thermal stimuli. Hence, the fluorescence intensity of dyad 9 is regulated by reversible conversion among the two states of the photochromic spiropyran units and the fluorescence resonance energy transfer (FRET) between the MC form of SP and the DPP unit. Conversely, these scrutiny of the experiment express that the design of dyad 9 is viable as efficient fluorescent switch molecule in many probable commercial applications, such as, logic gates and photonic and optical communications.

  17. Fluorescence-Based Sensors

    Science.gov (United States)

    Orellana, Guillermo

    The natural luminescent phenomena (from the Latin words "lumen" and "essentia", i.e., "made of light") such as northern lights (aurora borealis), marine brightness, glow-worms, shining putrid fish scales, "bluish"- appearing water when contained in certain wooden cups (quinine fluorescence), some stones heated at high temperatures with reducing agents (BaS phosphorescence), or light emitted while crushing sugar (triboluminescence) already fascinated our ancestors. Nowadays we understand that ultraviolet and visible emission of light originates from a competitive deactivation pathway of the lowest electronic excited state of atoms and molecules that produces the so called luminescence (the sub-terms fluorescence and phosphorescence just designate whether the return of the excited to the ground state is an "allowed" or "forbidden" process, namely it is fast or slow, the loosely-defined border between them being a 1-μs-1 rate constant). Actually, luminescence is the only method to generate light in the known Universe regardless it is powered by the nuclear reactions in the stars, the ohmical heating in bulbs, an electric discharge, the absorption of light or a (bio)chemical reaction (chemiluminescence).

  18. The TALE Fluorescence Detectors

    Science.gov (United States)

    Jui, Charles

    2009-05-01

    The TALE fluorescence detectors are designed to extend the threshold for fluorescence observation by TA down to 3x10^16 eV. It will comprise two main components. The first is a set of 24 telescopes working in stereo, with an existing TA FD station at ˜6 km separation. These will cover between 3-31 degrees in elevation and have azimuthal coverage maximizing the stereo aperture in the 10^18-10^19 eV energy range. The second component consists of 15 telescopes equipped with 4m diameter mirrors and covering the sky between 31 and 73 degrees in elevation. The larger mirror size pushes the physics threshold down to 3x10^16 eV, and provides view of the shower maximum for the lower energy events. The Tower detector will cover one quadrant in azimuth and operate in hybrid mode with the TALE infill array to provide redundant composition measurements from both shower maximum information and muon-to-electron ratio.

  19. A New Fluorescent Sensor for Transition Metal Ions in Aqueous Solution

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new fluorescent sensor consisted of fluorenyl and dioxotetraaza unit, namely, 2,10-dimethyl-6-(9-fluorenyl)-1,4,8,11-tetraazaundencane-5,7-dione (L), was synthesized. It is a fluorescent sensor for transition metal ions in aqueous solution.

  20. Mass spectrometry of pertrimethylsilyl oligosaccharides containing fructose units

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Kamerling, J.P.; Vink, Jan; Ridder, J.J. de

    1972-01-01

    Mass spectra of 6 TMS-disaccharides of type aldohexosyl-(1-> x)-fructose, in which x varies from 1 to 6, were compared and could be divided into two main groups i.e. (1 ar 1), (1 ar 2) disaccharides and (1 ar 3), (1 ar 4), (1 ar 5), (1 ar 6) disaccharides. Within both groups a further differentiatio

  1. Fluorescence of ceramic color standards.

    Science.gov (United States)

    Koo, Annette; Clare, John F; Nield, Kathryn M; Deadman, Andrew; Usadi, Eric

    2010-04-20

    Fluorescence has been found in color standards available for use in calibration and verification of color measuring instruments. The fluorescence is excited at wavelengths below about 600?nm and emitted above 700?nm, within the response range of silicon photodiodes, but at the edge of the response of most photomultipliers and outside the range commonly scanned in commercial colorimeters. The degree of fluorescence on two of a set of 12 glossy ceramic tiles is enough to introduce significant error when those tiles have been calibrated in one mode of measurement and are used in another. We report the nature of the fluorescence and the implications for color measurement.

  2. Probing interaction of a fluorescent ligand with HIV TAR RNA

    Science.gov (United States)

    Qi, Liang; Zhang, Jing; He, Tian; Huo, Yuan; Zhang, Zhi-Qi

    2017-02-01

    Trans-activator of Transcription (Tat) antagonists could block the interaction between Tat protein and its target, trans-activation responsive region (TAR) RNA, to inhibit Tat function and prevent human immunodeficiency virus type 1 (HIV-1) replication. For the first time, a small fluorescence ligand, ICR 191, was found to interact with TAR RNA at the Tat binding site and compete with Tat. It was also observed that the fluorescence of ICR 191 could be quenched when binding to TAR RNA and recovered when discharged via competition with Tat peptide or a well-known Tat inhibitor, neomycin B. The binding parameters of ICR 191 to TAR RNA were determined through theoretical calculations. Mass spectrometry, circular dichroism and molecular docking were used to further confirm the interaction of ICR 191 with TAR RNA. Inspired by these discoveries, a primary fluorescence model for the discovery of Tat antagonists was built using ICR 191 as a fluorescence indicator and the feasibility of this model was evaluated. This ligand-RNA interaction could provide a new strategy for research aimed at discovering Tat antagonists.

  3. Fluorescence dynamics of green fluorescent protein in AOT reversed micelles

    NARCIS (Netherlands)

    Uskova, M.A.; Borst, J.W.; Hink, M.A.; Hoek, van A.; Schots, A.; Klyachko, N.L.; Visser, A.J.W.G.

    2000-01-01

    We have used the enhanced green fluorescent protein (EGFP) to investigate the properties of surfactant-entrapped water pools in organic solvents (reversed micelles) with steady-state and time-resolved fluorescence methods. The surfactant used was sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and the

  4. Fluorescence Spectrometry on the Interaction of 4'-O-(α-L-oleandrosyl) daunorubicin with Calf Thymus DNA%抗癌药物4'-O-(α-L-夹竹桃糖基)柔红霉素与小牛胸腺DNA的相互作用的荧光光谱

    Institute of Scientific and Technical Information of China (English)

    崔凤灵; 霍瑞娜; 张贵生; 邢卫卫

    2012-01-01

    The interaction of 4'-O-(α-L-oleandrosyl)daunorubicin( ODNR) with calf thymus DNA(ctDNA) in Tris-HCl buffer solution (pH =7.4) was studied by fluorescence and ultraviolet absorption spectroscopies. Effects of the ionic strength, KI quenching, and the ODNR binding differences between the single stranded DNA(ssDNA) and the double stranded DNA(dsDNA) were studied. The results showed that the major binding mode between ODNR and ctDNA was intercalation. The intrinsic fluorescence of ODNR was quenched by ctDNA through static quenching procedure. The binding constants ( K) and sites ( n) at different temperatures were obtained by Scatchard equation. The predominant intermolecular forces are likely the hydrophobic and electrostatic interactions according to the thermodynamic parameters.%在pH =7.4的ris-HCl介质中,利用荧光光谱和紫外吸收光谱法,研究了一种新型蒽环类抗癌药物柔红霉素衍生物(4'-O-(α-L-夹竹桃糖基)柔红霉素,ODNR)与小牛胸腺DNA(ctDNA)的相互作用.通过离子强度的影响、KI荧光猝灭实验和单双链ctDNA作用的比较实验,分析了ODNR与ctDNA的相互作用模式.结果表明,ODNR通过嵌插方式与ctDNA发生作用.ctDNA对ODNR的荧光有明显的猝灭作用,其机理属于静态猝灭.通过Scatchard方程求得不同温度下的结合常数和结合位点数,由热力学参数确定分子间作用力为疏水作用,也可能存在静电作用.

  5. Fluxomics: mass spectrometry versus quantitative imaging.

    Science.gov (United States)

    Wiechert, Wolfgang; Schweissgut, Oliver; Takanaga, Hitomi; Frommer, Wolf B

    2007-06-01

    The recent development of analytic high-throughput technologies enables us to take a bird's view of how metabolism is regulated in real time. We have known for a long time that metabolism is highly regulated at all levels, including transcriptional, posttranslational and allosteric controls. Flux through a metabolic or signaling pathway is determined by the activity of its individual components. Fluxomics aims to define the genes involved in regulation by following the flux. Two technologies are used to monitor fluxes. Pulse labeling of the organism or cell with a tracer, such as 13C, followed by mass spectrometric analysis of the partitioning of label into different compounds provides an efficient tool to study flux and to compare the effect of mutations on flux. The second approach is based on the use of flux sensors, proteins that respond with a conformational change to ligand binding. Fluorescence resonance energy transfer (FRET) detects the conformational change and serves as a proxy for ligand concentration. In contrast to the mass spectrometry assays, FRET nanosensors monitor only a single compound. Both methods provide high time resolution. The major advantages of FRET nanosensors are that they yield data with cellular and subcellular resolution and the method is minimally invasive.

  6. Assay of ceftazidime and cefepime based on fluorescence quenching of carbon quantum dots.

    Science.gov (United States)

    Huang, Yu; Zhang, Ying; Yan, Zhengyu; Liao, Shenghua

    2015-11-01

    A novel and sensitive method for the determination of ceftazidime and cefepime in an active pharmaceutical ingredient (API) has been developed based on the fluorescence quenching of poly(ethylene glycol) (PEG)2000-capped carbon quantum dots (CQDs) prepared using a chemical oxidation method. The quenching of fluorescence intensity is proportional to the concentration of ceftazidime and cefepime over the range of 0.33-3.30 and 0.24-2.40 µg/mL, respectively. The mode of interaction between PEG2000-capped CQDs and ceftazidime/cefepime in aqueous solutions was investigated using a fluorescence, UV/Vis and Fourier transform infrared spectrometry (FTIR) at physiological pH. UV/Vis and FTIR spectra demonstrated that ground state compounds were formed through hydrophobic interaction the fluorescence quenching of CQDs caused by ceftazidime and cefepime. The quenching constants decreased with increases in temperature, which was consistent with static quenching.

  7. Analysis of 14 Elements for Jinhua Bergamot by X-Ray Fluorescence Spectrometry and Elemental Analyser%波长色散X射线荧光结合元素分析仪分析金华佛手14种元素

    Institute of Scientific and Technical Information of China (English)

    王志刚; 于红梅

    2012-01-01

    以VarioⅢ元素分析仪分析金华佛手C,H,O,N含量,以PW2400波长色散X射线荧光光谱仪定性扫描佛手样品,采用IQ+分析法分析Mg,Al,P,S,Cl,K,Ca,Mn,Fe,Sr元素含量.结果表明,将C,H,O,N元素含量作为固定项处理,结果较为理想;为防止样品表面脱落而采用Mylar膜将样品包裹技术,通过对膜系数的校准,分析结果比较理想.%The content of the elements C, H, O and N in Jinhua bergamot was analysed by using Vano Ⅲ elemental analyser, the bergamot sample was scanned by using X-ray fluorescence spectrometer with PW2400 wavelength dispersion, and the content of the elements Mg, Al, P, S, Cl, K, Ca, Mn, Fe and Sr was analysed by using IQ+ analytical method. It turned out that the result is more ideal if the content of the elements C, H, O and N is processed as fix phase, and the analytical result is more ideal if, to prevent the sample skin from coming off, the sample is wrapped with mylar film with the film coefficient adjusted.

  8. 波长色散X射线荧光光谱法测定铜精矿中铜铅锌硫镁砷%Determination of Cu, Pb, Zn, S, Mg and As in Copper Concentrates by Wavelength Dispersive X-ray Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    田琼; 黄健; 钟志光; 陈广文; 曲强; 洪武兴

    2009-01-01

    采用偏硼酸锂和四硼酸锂混合熔剂熔融法制样,波长色散X射线荧光光谱法测定铜精矿中铜、铅、锌、硫、镁、砷,考察了熔剂、玻璃化试剂和预氧化条件对制样的影响.采用理论α系数和经验系数相结合的方法校正元素间的效应.测定铜精矿试样各组分的相对标准偏差(RSD,n=12)均小于3%,结果与化学分析法吻合.%A method for direct determination of Cu, Pb, Zn, S, Mg and As in copper sulphide concentrates by Axios PW4400 wavelength dispersive X-ray fluorescence spectrometer using lithium metaborate-lithium tetraborate fusion sample preparation method has been developed. Some parameters affecting the sample preparation such as flux, glassing reagent and pre-oxidation condition were studied. The matrix effect was corrected by combination of the theoretical alpha coefficients and experienced coefficients. The precision of the method is better than 3.0% RSD(n = 12).

  9. 熔融制样X射线荧光光谱法测定海洋沉积物中主次痕量元素%Fusion sample X-ray fluorescence spectrometry major and minor trace elements in marine sediments

    Institute of Scientific and Technical Information of China (English)

    金斌; 吴磊; 刘义博; 吴良英; 董俊

    2013-01-01

      熔融片法制样,用 PW2440 X 射线荧光光谱仪测定海洋沉积物样品中 Na、Mg、Al、Si、P、S、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Ni、Cu、Zn、Ba、Ga、Y、Zr、La、Ce、Nb、Rb、Sr 等26种组分,用国家海洋标准物质和人工合成标样作为校准样品,使用理论α系数和经验系数相结合的方法校正基体效应。方法用海洋沉积物国家一级标准物质验证,测定值与标准值吻合。%  molten film sample preparation, with the PW2440 X-ray testing fluorescence spectrometer marine sediment samples Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ba, Ga, Y, Zr, La, Ce, Nb, Rb, Sr and other 26 kinds of components, with the national Oceanic standard materials and synthetic samples as a calibration standard, using theoretical and empirical coefficients α factor combination the matrix effect correction method. Methods using national marine sediment reference material verification, the measured value consistent with the standard value.

  10. Assessing Photosynthesis by Fluorescence Imaging

    Science.gov (United States)

    Saura, Pedro; Quiles, Maria Jose

    2011-01-01

    This practical paper describes a novel fluorescence imaging experiment to study the three processes of photochemistry, fluorescence and thermal energy dissipation, which compete during the dissipation of excitation energy in photosynthesis. The technique represents a non-invasive tool for revealing and understanding the spatial heterogeneity in…

  11. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  12. [Excitation-Emission Matrix Fluorescence Spectra Characteristics of DOM in Integrated Verical Flow Constructed Wetland for Treating Eutrophic Water].

    Science.gov (United States)

    Li, Shu-juan; Ge, Li-yun; Deng, Huan-huan

    2015-04-01

    Three-dimensional fluorescence parameters can reflect classification, properties and content change of pollutants in wastewater treatment. In the present paper, by using three-dimensional fluorescence characteristic analysis, comparative analysis of conventional organic pollutants such as COD, TN and TP, and three dimensional fluorescence spectrum analysis, the classification and content of dissolved organic pollutants were identified. We studied fluorescence spectra, fluorescence peak (R. U.), fluorescence index (FI), humification index (HIX) of DOM's four components in the entrance and effluent water and interstitial water, as well as the correlation between these four components and COD, TN and TP. The results showed that the position and intensity of the characteristic fluorescence peak center changed significantly before and after sewage treatment, indicating that the relative composition and content of the organic wastewater varied with wastewater treatment. Furthermore, the test results presented that humic-like composition was not degraded significantly, while protein-like composition was degraded significantly. And the protein-like component and COD, TN and TP presented significant positive correlation. This paper analyzed the fluorescence characteristics changes of dissolved organic matter in sewage treatment by using three-dimensional fluorescence spectrometry, and discussed the feasibility of three-dimensional fluorescence technique applied for description of dissolved organic pollutant degradation rule in the wastewater treatment process.

  13. Optical Properties of Fluorescent Dyes

    Institute of Scientific and Technical Information of China (English)

    李戎; 陈东辉

    2001-01-01

    Fluorescent dyes have been widely used these years.Because of the special optical performance, conventional CCM systems seem to be unable to predict the recipes of fabrics dyed with fluorescent dyes. In order to enhance the functions of CCM systems, the optical properties of fluorescent dyes in their absorption region were investigated. It has been found that there was a fixed maximum absorption wavelength for each fluorescent dyes whatever its concentration is. Both absorption region and maximum absorption wavelength of the dyes in solution are the same to those in fabric, and that the absorption is directly proportional to the concentration of the dye. So the optical properties obtained in solutions cna be applied for describing the optics performance of fluorescent dyes in fabrics.

  14. Fluorescent nanoparticle beacon for logic gate operation regulated by strand displacement.

    Science.gov (United States)

    Yang, Jing; Shen, Lingjing; Ma, Jingjing; Schlaberg, H Inaki; Liu, Shi; Xu, Jin; Zhang, Cheng

    2013-06-26

    A mechanism is developed to construct a logic system by employing DNA/gold nanoparticle (AuNP) conjugates as a basic work unit, utilizing a fluorescent beacon probe to detect output signals. To implement the logic circuit, a self-assembly DNA structure is attached onto nanoparticles to form the fluorescent beacon. Moreover, assisted by regulation of multilevel strand displacement, cascaded logic gates are achieved. The computing results are detected by methods using fluorescent signals, gel electrophoresis and transmission electron microscope (TEM). This work is expected to demonstrate the feasibility of the cascaded logic system based on fluorescent nanoparticle beacons, suggesting applications in DNA computation and biotechnology.

  15. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  16. Functional genomics by mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Mann, M

    2000-01-01

    Systematic analysis of the function of genes can take place at the oligonucleotide or protein level. The latter has the advantage of being closest to function, since it is proteins that perform most of the reactions necessary for the cell. For most protein based ('proteomic') approaches to gene...... function, mass spectrometry is the method of choice. Mass spectrometry can now identify proteins with very high sensitivity and medium to high throughput. New instrumentation for the analysis of the proteome has been developed including a MALDI hybrid quadrupole time of flight instrument which combines...... numbers of intact proteins by mass spectrometry directly. Examples from this laboratory illustrate biological problem solving by modern mass spectrometric techniques. These include the analysis of the structure and function of the nucleolus and the analysis of signaling complexes....

  17. Fluorescence calibration method for single-particle aerosol fluorescence instruments

    Science.gov (United States)

    Shipley Robinson, Ellis; Gao, Ru-Shan; Schwarz, Joshua P.; Fahey, David W.; Perring, Anne E.

    2017-05-01

    Real-time, single-particle fluorescence instruments used to detect atmospheric bioaerosol particles are increasingly common, yet no standard fluorescence calibration method exists for this technique. This gap limits the utility of these instruments as quantitative tools and complicates comparisons between different measurement campaigns. To address this need, we have developed a method to produce size-selected particles with a known mass of fluorophore, which we use to calibrate the fluorescence detection of a Wideband Integrated Bioaerosol Sensor (WIBS-4A). We use mixed tryptophan-ammonium sulfate particles to calibrate one detector (FL1; excitation = 280 nm, emission = 310-400 nm) and pure quinine particles to calibrate the other (FL2; excitation = 280 nm, emission = 420-650 nm). The relationship between fluorescence and mass for the mixed tryptophan-ammonium sulfate particles is linear, while that for the pure quinine particles is nonlinear, likely indicating that not all of the quinine mass contributes to the observed fluorescence. Nonetheless, both materials produce a repeatable response between observed fluorescence and particle mass. This procedure allows users to set the detector gains to achieve a known absolute response, calculate the limits of detection for a given instrument, improve the repeatability of the instrumental setup, and facilitate intercomparisons between different instruments. We recommend calibration of single-particle fluorescence instruments using these methods.

  18. Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

    Energy Technology Data Exchange (ETDEWEB)

    Mihucz, Victor G. [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); Moricz, Agnes M. [L. Eoetvoes University, Department of Chemical Technology and Environmental Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Kroepfl, Krisztina [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Szikora, Szilvia [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Tatar, Eniko [Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Parra, Lue Meru Marco [Universidad Centro-occidental Lisandro Alvarado, Decanato de Agronomia, Departamento de Quimica y Suelos Unidad de Analisis Instrumental, Apartado Postal 4076, Cabudare 3023 (Venezuela); Zaray, Gyula [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary) and Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary) and L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary)]. E-mail: zaray@ludens.elte.hu

    2006-11-15

    Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods.

  19. Mass spectrometry for biomarker development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chaochao; Liu, Tao; Baker, Erin Shammel; Rodland, Karin D.; Smith, Richard D.

    2015-06-19

    Biomarkers potentially play a crucial role in early disease diagnosis, prognosis and targeted therapy. In the past decade, mass spectrometry based proteomics has become increasingly important in biomarker development due to large advances in technology and associated methods. This chapter mainly focuses on the application of broad (e.g. shotgun) proteomics in biomarker discovery and the utility of targeted proteomics in biomarker verification and validation. A range of mass spectrometry methodologies are discussed emphasizing their efficacy in the different stages in biomarker development, with a particular emphasis on blood biomarker development.

  20. PT-GC-CAFS联用技术测定污水处理厂外排水中烷基汞残留量%Determination of the Alkyl Mercury Residue in External Drainage of Partial of Sewage Treatment Plants by Purging Capture-Gas Chromatography-Cold Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    高兰兰; 徐浩; 杨琼; 戴刚

    2016-01-01

    建立了吹扫捕集-气相色谱-冷原子荧光( PT-GC-CAFS)联用技术、多功能自动进样器进样测定污水处理厂外排水中烷基汞残留量的方法. 用烷基化试剂直接衍生,吹扫捕集吸附/富集,以PEG20M填充柱为分离柱,用冷原子荧光作为检测器进行测定,整体分析工作在10 min内完成. 在所选实验条件下,方法对所测甲基汞、乙基汞的线性相关系数分别为0.999 9、1.000,最低检出限分别为0.002、0.003 ng/L,相对标准偏差为1.4% ~10.2%,2.3% ~9.7%;在不同质量浓度水平上进行加标回收率实验,甲基汞的回收率为93.7% ~101.7%,乙基汞为94.1% ~103.6%. 该方法用于污水处理厂外排水中烷基汞残留量的分析测定,结果令人满意.%A confirmative method was developed with purge and trap-GC separation-cold atomic fluorescence spectrophotometer ( PT-GC-CAFS) to detect the residues of alkyl mercury in external drainage of sewage treatment plants by multifunctional automatic sampler. Using direct derivative alkyl mercury by Alkylating reagent, adsorption/enrichment by PT, with PEG20M packed column for separation column, and with cold atomic fluorescence spectrophotometer as a detector to detect mercury in environmental water samples, the overall analysis of the work to be done within 10 min. The method showed that good linear correlation coefficient of methyl mercury′s and ethyl mercury′s was 0.999 9 and 1.000, the relative standard deviation was (RSD=1.4%-10.2%) and ( RSD=2.3%-9.7%) , respectively. With different quality levels to Standard addition recovery test sample, the recovery rate of methyl mercury was 93.7%-101.7%, ethyl mercury was 94.1%-103.6%. The method was applied to determine the alkyl mercury residue in external drainage samples of sewage treatment plants. The results were satisfactory.

  1. Multiplex fluorescent immunoassay device based on magnetic nanoparticles

    Science.gov (United States)

    Godjevargova, T. I.; Ivanov, Y. L.; Dinev, D. D.

    2017-02-01

    Immunofluorescent analyzer based compact disc for simultaneous detection of 3 antibiotics in the same milk sample is consisting of two parts: CD-based immunofluorescence kit and optoelectronic fluorometer. Kit consists of 2 parts: Lyophilized immobilized antibodies on supermagnetic nanoparticles in Eppendorf tubes and CD-based microfluidic disk, in which are formed five chamber systems for simultaneous detecting of 5 separate samples. Each system consists of 2 chambers connected by a special micro channel acting as a hydrophobic valve. In the first chamber lyophilised conjugates of 3 antibiotics with accordingly 3 different fluorescent dyes are placed. The second chamber is for detection of fluorescent signal. The optoelectronic fluorometer is comprising of: integrated thermostatic block; mechanical-detecting unit (fluorometer) and block with controlling and visualizing electronics.The disc gets into a second block of the analyzer, where centrifugation is performed and also reporting of the fluorescent signals. This unit comprises a rotor on which the disc is fixed, permanent electromagnet in the form of a ring inserted under the disc and module of 3 LED diodes with emission filters for the relevant wavelengths corresponding to the used fluorescent dyes and 1 integrated photodiode, in front of which is mounted filter with 3 spectral peaks.The signal from the photodiode is detected by the electronic unit which is sensitive "lock-in" amplifier, the engine rotor management, control of thermostatic device and management of periphery of the analyzer, consisting of display and communications with computer.

  2. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging

    NARCIS (Netherlands)

    Kiss, A.; Smith, D.F.; Jungmann, JH; Heeren, R.M.A.

    2013-01-01

    RATIONALE: Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with

  3. X-RAY FLUORESCENCE ANALYSIS OF HANFORD LOW ACTIVITY WASTE SIMULANTS METHOD DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Jurgensen, A; David Missimer, D; Ronny Rutherford, R

    2007-08-08

    The x-ray fluorescence laboratory (XRF) in the Analytical Development Directorate (ADD) of the Savannah River National Laboratory (SRNL) was requested to develop an x-ray fluorescence spectrometry method for elemental characterization of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) pretreated low activity waste (LAW) stream to the LAW Vitrification Plant. The WTP is evaluating the potential for using XRF as a rapid turnaround technique to support LAW product compliance and glass former batching. The overall objective of this task was to develop an XRF analytical method that provides rapid turnaround time (<8 hours), while providing sufficient accuracy and precision to determine variations in waste.

  4. Fluorescence-Based Sensor for Monitoring Activation of Lunar Dust

    Science.gov (United States)

    Wallace, William T.; Jeevarajan, Antony S.

    2012-01-01

    This sensor unit is designed to determine the level of activation of lunar dust or simulant particles using a fluorescent technique. Activation of the surface of a lunar soil sample (for instance, through grinding) should produce a freshly fractured surface. When these reactive surfaces interact with oxygen and water, they produce hydroxyl radicals. These radicals will react with a terephthalate diluted in the aqueous medium to form 2-hydroxyterephthalate. The fluorescence produced by 2-hydroxyterephthalate provides qualitative proof of the activation of the sample. Using a calibration curve produced by synthesized 2-hydroxyterephthalate, the amount of hydroxyl radicals produced as a function of sample concentration can also be determined.

  5. Single Molecule Spectroscopy of Fluorescent Proteins

    NARCIS (Netherlands)

    Blum, Christian; Subramaniam, Vinod

    2009-01-01

    The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject to intense research. Understanding the

  6. FLEX: fluorescence explorer

    Science.gov (United States)

    Stoll, Marc-Ph.; Court, Andrew; Smorenburg, Kees; Visser, Huib; Crocco, Luiggi; Heilimo, Jyro; Honig, Andre

    1999-12-01

    FLEX is a scientifically driven space mission to provide demonstration/validation of the instrumentation and technique for measuring the natural fluorescence of vegetation in the Fraunhofer lines. The payload consists of high spectral resolution (0.1 - 0.3 nm) CCD imaging grating spectrometer with two channels: one in the red (648 - 664 nm) and one in the blue (391 - 438 nm) for working with several Fraunhofer lines. The across track FOV is 8.4 degrees; ground spatial resolution is better than 0.5 X 0.5 km2. To increase the S/N ratio a steering mirror will be used, if necessary, to 'freeze' the image and also to provide plus or minus 4 degrees across track depointing. Calibration is made by viewing the sun via a diffuser plate switched into the telescope field of view. A separate CCD camera will allow cloud detection and scene identification. A TIR radiometer will provide simultaneous surface temperature measurements. The spacecraft, overall mass estimated at 200 kg, is derived from the ASI-MITA bus which provides all the necessary subsystems and stabilized platform. By use of on-board storage, ground requirements for satellite control and data link are minimized; the possibility of local stations for real time reception/distribution is also envisaged. Provisional orbit characteristics are: LEO sun synchronous, 500 - 900 km altitude. Priority will be given to highest revisit frequency on a sufficient number of selected test sites.

  7. Fluorescent blood cell angiography

    Science.gov (United States)

    Ben-nun, Joshua; Constable, Ian J.

    1994-06-01

    Fluorescein angiography is currently the main method for evaluation of the retinal vascular patency. Ashton noted that capillary patency to the small fluorescein molecule may differ from that of the larger red blood cells. He concluded that fluorescein angiography is not able to demonstrate a developing stenosis, that might be the precipitating cause of a later capillary closure in various microvasculopathies. Sarelius et al have shown, in hamster cheek pouch and cremaster muscle, that fluorescently labeled erythrocytes in known concentrations can be used for the direct measurement of capillary flow parameters. The only assumption that this method relies on, is that the labeled cells are rheologically normal and therefore reflect the behavior of the total cell population. We have developed a new method for an in-vivo, real-time demonstration of the blood cell flow in the retinal capillary net. Based on the assumption presented by Sarelius et al, measurement and analysis of the retinal capillary blood cell flow is also possible from the results achieved by the new method.

  8. Fluorescence endoscopy and photodynamic therapy.

    Science.gov (United States)

    Messmann, H; Endlicher, E; Gelbmann, C M; Schölmerich, J

    2002-10-01

    Fluorescence endoscopy is a new technique which allows a better detection of non-visible malignant or premalignant lesions or, those which are difficult to detect. Exogenously applied sensitisers accumulate selectively in malignant lesions and induce fluorescence after illumination with light of adequate wavelength. However, also endogenous fluorophores, different located in malignant or benign lesions, induce a different autofluorescence in these lesions. Tissue fluorescence can be detected by optical sampling of the mucosa using fluorescence spectroscopy or by generating real time fluorescence images with specialised camera systems. Compared to point fluorescence spectroscopy the latter technique enables the screening of large surface areas of mucosa. Meanwhile, fluorescence endoscopy is a widely used technique in urology employing 5-aminolaevulinic acid sensitisation. In gastroenterology, this technique seems promising for the detection of early cancers or dysplasia in patients with Barrett's oesophagus or ulcerative colitis. Using different sensitisers, photodynamic therapy seems to be a promising option for patients with advanced oesophageal cancer and in the palliative treatment of non-resectable bile duct cancer, furthermore for patients with early gastric cancer and dysplasia in Barrett's oesophagus. Probably, by laser light fractionation or a combination of different sensitisers, an enhanced effect can be expected.

  9. Determination of catalyst metal residues in polymers by X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Bichinho, Katia M. [CIENTEC-Fundacao de Ciencia e Tecnologia, Rua Washington Luiz, 675, Porto Alegre, 90010-460 (Brazil); Pires, Gilvan Pozzobon [Instituto de Quimica, Universidade Federal do Rio Grande do Sul (UFRGS) Avenida Bento Goncalves 9500, Porto Alegre, 91501-970 (Brazil); Stedile, Fernanda C. [Instituto de Quimica, Universidade Federal do Rio Grande do Sul (UFRGS) Avenida Bento Goncalves 9500, Porto Alegre, 91501-970 (Brazil); Santos, Joao Henrique Z. dos [Instituto de Quimica, Universidade Federal do Rio Grande do Sul (UFRGS) Avenida Bento Goncalves 9500, Porto Alegre, 91501-970 (Brazil)]. E-mail: jhzds@iq.ufrgs.br; Wolf, Carlos Rodolfo [Ipiranga Petroquimica S.A., Departamento de Desenvolvimento de Produto, Polo Petroquimico do Sul, BR 386, km 419, Triunfo, CEP 95853-000 (Brazil)

    2005-06-30

    Commercial polyethylenes produced by Ziegler-Natta, Philips and metallocene technology were analyzed by X-ray fluorescence spectroscopy. Synthetic standards using wax matrix was shown to be suitable for the calibration curve in comparison to those prepared by milling and grinding virgin polymer mixed with standard metal oxide as matrix. The detection limits obtained for the studied metal in the different polymers were: 12 mg kg{sup -1} for Mg, 0.8 mg kg{sup -1} for Ti, 1.6 mg kg{sup -1} for Cr, 1.2 mg kg{sup -1} for Zr and 1.9 mg kg{sup -1} for V. For comparative reasons, the determination of residual metal content by Rutherford backscattering spectrometry (RBS) and total-reflection X-ray fluorescence spectrometry (TXRF) is also discussed.

  10. Mass Spectrometry Instrumentation in Proteomics

    DEFF Research Database (Denmark)

    Sprenger, Richard Remko; Roepstorff, Peter

    2012-01-01

    Mass spectrometry has evolved into a crucial technology for the field of proteomics, enabling the comprehensive study of proteins in biological systems. Innovative developments have yielded flexible and versatile mass spectrometric tools, including quadrupole time-of-flight, linear ion trap...

  11. An Optic/Proton Dual-Controlled Fluorescence Switch based on Novel Photochromic Bithienylethene Derivatives

    Institute of Scientific and Technical Information of China (English)

    张佳琦; 靳家玉; 张隽佶; 邹雷

    2012-01-01

    A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds (4a, 4b, 4c) have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers (FRET) from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.

  12. pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.

    Science.gov (United States)

    Adachi, Naoya; Kaneko, Yuki; Sekiguchi, Kazuki; Sugiyama, Hiroki; Sugeno, Masafumi

    2015-12-01

    Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing.

  13. Assessing Raw and Treated Water Quality Using Fluorescence Spectroscopy

    Science.gov (United States)

    Bridgeman, J.; Baker, A.

    2006-12-01

    To date, much fluorescence spectroscopy work has focused on the use of techniques to characterize pollution in river water and to fingerprint pollutants such as, inter alia, treated and raw sewage effluent. In the face of tightening water quality standards associated with disinfection byproducts, there exists the need for a surrogate THM parameter which can be measured accurately and quickly at the water treatment works and which will give a satisfactory indication of the THM concentration leaving the water treatment works. In addition, water treatment works and distribution system managers require tools which are simple and quick, yet robust, to monitor plant and unit process performance. We extend the use of fluorescence techniques from raw water quality monitoring to (1) the monitoring of water treatment works intakes and the assessment of water treatment works performance by (2) assessing the removal of dissolved organic matter (DOM) through the unit process stages of various water treatment works treating different raw waters and (3) examining the prevalence of microbiological activity found at service reservoirs in the downstream distribution system. 16 surface water treatment works were selected in the central region of the UK and samples taken at works' intakes, downstream of each unit process, and in the distribution systems. The intakes selected abstract water from a broad range of upland and lowland water sources with varying natural and anthropogenic pollutant inputs and significantly different flows. The treatment works selected offer a range of different, but relatively standard, unit processes. The results demonstrate that raw waters exhibit more fluorescence than (partially) treated waters. However, noticeable differences between each site are observed. Furthermore, differences in unit process performance between works are also identified and quantified. Across all sites, treatment with Granular Activated Carbon is found to yield a significant

  14. Modular generation of fluorescent phycobiliproteins.

    Science.gov (United States)

    Wu, Xian-Jun; Chang, Kun; Luo, Juan; Zhou, Ming; Scheer, Hugo; Zhao, Kai-Hong

    2013-06-01

    Phycobiliproteins are brightly-fluorescent light-harvesting pigments for photosynthesis in cyanobacteria and red algae. They are also of interest as fluorescent biomarkers, but their heterologous generation in vivo has previously required multiple transformations. We report here a modular approach that requires only two DNA segments. The first codes for the apo-protein. The second codes for fusions capable of chromophore biosynthesis and its covalent attachment to the apo-protein; it contains the genes of heme oxygenase, a bilin reductase, and a chromophore lyase. Phycobiliproteins containing phycoerythrobilin (λ(fluor) ~ 560 nm), phycourobilin (λ(fluor) ~ 500 nm), phycocyanobilin (λ(fluor) ~ 630 nm) or phycoviolobilin (λ(fluor) ~ 580 nm) were obtained in high yield in E. coli. This approach facilitates chromophorylation studies of phycobiliproteins, as well as their use for fluorescence labeling based on their high fluorescence.

  15. Fluorescence diagnosis in tissue injury

    Science.gov (United States)

    Maciel, Vitória H.; Ferreira, Juliana; Bagnato, Vanderlei S.

    2009-06-01

    Background and Objectives: The paper aim was to evaluate the efficacy of the fluorescence spectroscopy in the detection of UV-induced skin change of Wistar rats. Study Design/ Materials and Methods: In a group male Wistar rats, the skin damage was produced by an UV-C lamp, periodically monitored using the laser-induced fluorescence, until complete healing process. After determining a characteristic emission band present in the fluorescence spectra of the induced injuries, the amplitude band monitoring allowed the follow up on the injury and the recovery. Results: We observed the appearance of two new emission bands more evident at the injury spectra when compared to the spectrums from normal non-exposed tissue. Following such spectral bands was possible to observe the establishment and recovery. Conclusions: The fluorescence spectroscopy is a promising technique in distinguishing between normal and UV induced skin change helping the evaluation of changes which are irreversible cancer tissue characteristics.

  16. Fluorescent Sensors for Biological Applications

    Directory of Open Access Journals (Sweden)

    Hui-wang Ai

    2014-09-01

    Full Text Available Fluorescence is one of the most important analytical methods used in biological studies. In the past decade or two, instrumentation in this field has greatly advanced, and now it is possible to detect single photons or fluorescent molecules [1,2], or break the Abbe diffraction limit to distinguish two points spaced less than 50 nm apart [3]. Concurrently, the development of improved fluorescent probes, which can be coupled with state-of-the-art instruments, has been equally important. This special issue on “fluorescent biosensors” in Sensors reports recent results from eight research groups in the field of sensor development. It includes three review articles, and six research articles reporting original results. [...

  17. Naphthatimide as Highly Selective Fluorescent Sensor for Ag+ Ions

    Institute of Scientific and Technical Information of China (English)

    XU,Sheng; LI,Wei; CHEN,Kong-Chang

    2007-01-01

    The naphthalimide derivative NA1 was synthesized, which consists of a bis(2-(ethylthio)ethyl)amine group binding cations and naphthalimide unit as chromogenic and fluorogenic signaling subunit. Absorption and emission spectra and the effect of polarity of solvents and pH values were studied. The photo-induced electron transfer (PET) occurred from the donor of bis(2-(ethylthio)ethyl)amine group to the naphthalimide fluorophore. The present study demonstrates that NA1 is a viable candidate as a fluorescent receptor for a new Ag+ ion sensor. This silver ion chemosensor can discriminate Ag+ ion well among heavy metal ions by an enhancement of the fluorescence intensity in ethanol-water (1:9, V:V). And NA1 is also a pH-sensor because the fluorescence of the compound varies with the pH values.

  18. 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)

  19. 地质样品铷锶钇锆元素偏振能量色散X射线荧光光谱分析结果不确定度的评估%The Evaluation of Uncertainty in the Results for Elements Rubidium, Strontium, Yttrium and Zirconium in Silicate Geological Samples by Polarized Energy Dispersive X-Ray Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    王祎亚; 詹秀春; 袁继海; 樊兴涛

    2011-01-01

    建立了一种以相对误差的标准偏差统计不确定度的评估方法.运用镶边压片技术制备样片,用Spectm X-Lab 2000型偏振能量色散X射线荧光光谱(P-EDXRF)仪器分析硅酸盐基体的76个国家一级标准物质和89个地质行业多目标考核样品,研究表明165个样品Rb,Sr,Y和Zr元素测量结果的相对误差符合正态分布(置信度为95%).以此为依据,分段统计相对误差的标准偏差作为对应浓度段被测量结果的总相对不确定度,扩展因子为2.分段统计精密度引起的相对不确定度,剥离出准确度引起的相对不确定度.不同元素准确度引起的相对不确定度在总不确定度中所占比例不同.通过"实验室测量审核结果公式"和"标准值及其扩展不确定度与测试修正值及其扩展不确定度的比较"丽种方式,验证了总相对不确定度统计方式具有合理性.%A method for evaluation of uncertainty was established with standard deviation of relative error. Utilizing a polarized energy dispersive x ray fluorescence spectrometer(P-EDXRF)X-lab 2000 with pressed polyethylene-backed pellets, 76 national reference materials and 89 geological examination samples were analyzed, the results indicated that the relative errors consist with the normal distribution with confidence level 95%. The section standard deviations of relative errors acted as method global relative uncertainty and expanded factor was 2. The section relative uncertainty caused by precision was analyzed and relative uncertainty caused by accuracy based on the error transfer formula was isolated. The ratio of relative uncertainty caused by accuracy to the global relative uncertainty was different with different levels and elements. Two methods validated that the evaluation of global uncertainty is reasonable, with the first method being the formula of audited results in laboratory, and the second being the comparison of standard value with expanded uncertainty and a

  20. Fluorescence lifetimes: fundamentals and interpretations.

    Science.gov (United States)

    Noomnarm, Ulai; Clegg, Robert M

    2009-01-01

    Fluorescence measurements have been an established mainstay of photosynthesis experiments for many decades. Because in the photosynthesis literature the basics of excited states and their fates are not usually described, we have presented here an easily understandable text for biology students in the style of a chapter in a text book. In this review we give an educational overview of fundamental physical principles of fluorescence, with emphasis on the temporal response of emission. Escape from the excited state of a molecule is a dynamic event, and the fluorescence emission is in direct kinetic competition with several other pathways of de-excitation. It is essentially through a kinetic competition between all the pathways of de-excitation that we gain information about the fluorescent sample on the molecular scale. A simple probability allegory is presented that illustrates the basic ideas that are important for understanding and interpreting most fluorescence experiments. We also briefly point out challenges that confront the experimenter when interpreting time-resolved fluorescence responses.

  1. Fluorescence detection of esophageal neoplasia

    Science.gov (United States)

    Borisova, E.; Vladimirov, B.; Avramov, L.

    2008-06-01

    White-light endoscopy is well-established and wide used modality. However, despite the many technological advances that have been occurred, conventional endoscopy is suboptimal and usually detects advanced stage lesions. The limitations of standard endoscopy initiate development of spectroscopic techniques, additional to standard endoscopic equipment. One of the most sensitive approaches is fluorescence spectroscopy of gastrointestinal mucosa for neoplasia detection. In the recent study delta-aminolevulinic acid/Protoporphyrin IX (5-ALA/PpIX) is used as fluorescent marker for dysplasia and tumor detection in esophagus. The 5-ALA is administered per os six hours before measurements at dose 20 mg/kg weight. Excitation source has max of emission at 405 nm and light is delivered by the standard light guide of the endoscopic equipment. Through endoscopic instrumental channel a fiber is applied to return information about fluorescence to microspectrometer. Spectral features observed during endoscopic investigations could be distinct as the next regions: 450-630 nm region, where tissue autofluorescence is observed; 630-710 nm region, where fluorescence of PpIX is clearly pronounced; 530-580 nm region, where minima in the autofluorescence signal are observed, related to reabsorption of blood. The lack of fluorescence peaks in the red spectral area for normal mucosa is an indication for selective accumulation of 5-ALA/PpIX only in abnormal sites Very good correlation between fluorescence signals and histology examination of the lesions investigated is achieved.

  2. A mass spectrometry primer for mass spectrometry imaging.

    Science.gov (United States)

    Rubakhin, Stanislav S; Sweedler, Jonathan V

    2010-01-01

    Mass spectrometry imaging (MSI), a rapidly growing subfield of chemical imaging, employs mass spectrometry (MS) technologies to create single- and multi-dimensional localization maps for a variety of atoms and molecules. Complimentary to other imaging approaches, MSI provides high chemical specificity and broad analyte coverage. This powerful analytical toolset is capable of measuring the distribution of many classes of inorganics, metabolites, proteins, and pharmaceuticals in chemically and structurally complex biological specimens in vivo, in vitro, and in situ. The MSI approaches highlighted in this Methods in Molecular Biology volume provide flexibility of detection, characterization, and identification of multiple known and unknown analytes. The goal of this chapter is to introduce investigators who may be unfamiliar with MS to the basic principles of the mass spectrometric approaches as used in MSI. In addition to guidelines for choosing the most suitable MSI method for specific investigations, cross-references are provided to the chapters in this volume that describe the appropriate experimental protocols.

  3. A modified fluorescent intercalator displacement assay for RNA ligand discovery.

    Science.gov (United States)

    Asare-Okai, Papa Nii; Chow, Christine S

    2011-01-15

    Fluorescent intercalator displacement (FID) is a convenient and practical tool for identifying new nucleic acid-binding ligands. The success of FID is based on the fact that it can be fashioned into a versatile screening assay for assessing the relative binding affinities of compounds to nucleic acids. FID is a tagless approach; the target RNAs and the ligands or small molecules under investigation do not need to be modified in order to be examined. In this study, a modified FID assay for screening RNA-binding ligands was established using 3-methyl-2-((1-(3-(trimethylammonio)propyl)-4-quinolinylidene)methyl)benzothiazolium (TO-PRO) as the fluorescent indicator. Electrospray ionization mass spectrometry (ESI-MS) results provide direct evidence that correlates the reduction in fluorescence intensity observed in the FID assay with displacement of the dye molecule from RNA. The assay was successfully applied to screen a variety of RNA-binding ligands with a set of small hairpin RNAs. Ligands that bind with moderate affinity to the chosen RNA constructs (A-site, TAR [transactivation response element], h31 [helix 31], and H69 [helix 69] were identified. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. Laser-Excited Fluorescence Spectra of Strontium Monoiodide.

    Science.gov (United States)

    Bernard; Effantin; d'incan; Topouzkhanian; Wannous

    1999-05-01

    Fluorescence spectra of strontium monoiodide excited by Ar++ and Kr+ laser lines have been analyzed by Fourier transform spectrometry. Rotational levels have been populated either directly or after collisional relaxation: (i) in D2Sigma+ (v = 0, 1) by ultraviolet lines of Ar++, inducing numerous fluorescence transitions ending in the levels v = 0-3 of the strongly interacting A2Pi and B2Sigma+ states, (ii) in A2Pi3/2 (v = 0-4) by Kr+ line at 676.44 nm, de-exciting into transitions to X2Sigma+ (v = 0-6). Deperturbed constants for A2Pi and B2Sigma+ states and A approximately B interaction parameter are calculated from the numerical treatment of D2Sigma+ (v = 0, 1) --> A2Pi (v = 0-3) approximately B2Sigma+ (v = 0-3) transitions. Rotational constants for D2Sigma+ (v = 0, 1) are obtained for the first time. The wavenumbers of some 670 fluorescence lines are cataloged. Copyright 1999 Academic Press.

  5. Characterization of ambient aerosols at the San Francisco International Airport using BioAerosol Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Steele, P T; McJimpsey, E L; Coffee, K R; Fergenson, D P; Riot, V J; Tobias, H J; Woods, B W; Gard, E E; Frank, M

    2006-03-16

    The BioAerosol Mass Spectrometry (BAMS) system is a rapidly fieldable, fully autonomous instrument that can perform correlated measurements of multiple orthogonal properties of individual aerosol particles. The BAMS front end uses optical techniques to nondestructively measure a particle's aerodynamic diameter and fluorescence properties. Fluorescence can be excited at 266nm or 355nm and is detected in two broad wavelength bands. Individual particles with appropriate size and fluorescence properties can then be analyzed more thoroughly in a dual-polarity time-of-flight mass spectrometer. Over the course of two deployments to the San Francisco International Airport, more than 6.5 million individual aerosol particles were fully analyzed by the system. Analysis of the resulting data has provided a number of important insights relevant to rapid bioaerosol detection, which are described here.

  6. Analysis of Protein O-GlcNAcylation by Mass Spectrometry.

    Science.gov (United States)

    Ma, Junfeng; Hart, Gerald W

    2017-02-02

    O-linked β-D-N-acetyl glucosamine (O-GlcNAc) addition (O-GlcNAcylation), a post-translational modification of serine/threonine residues of proteins, is involved in diverse cellular metabolic and signaling pathways. Aberrant O-GlcNAcylation underlies the initiation and progression of multiple chronic diseases including diabetes, cancer, and neurodegenerative diseases. Numerous methods have been developed for the analysis of protein O-GlcNAcylation, but instead of discussing the classical biochemical techniques, this unit covers O-GlcNAc characterization by combining several enrichment methods and mass spectrometry detection techniques [including collision-induced dissociation (CID), higher energy collision dissociation (HCD), and electron transfer dissociation (ETD) mass spectrometry]. © 2017 by John Wiley & Sons, Inc.

  7. Generating Units

    Data.gov (United States)

    Department of Homeland Security — Generating Units are any combination of physically connected generators, reactors, boilers, combustion turbines, and other prime movers operated together to produce...

  8. Fluorescent sensor for Cu2+ with a tunable emission wavelength.

    Science.gov (United States)

    Mokhir, Andriy; Kiel, Alexander; Herten, Dirk-Peter; Kraemer, Roland

    2005-08-08

    A concept of fluorescent metal ion sensing with an easily tunable emission wavelength is presented and its principle demonstrated by detection of Cu(2+). A fluorescein dye was chemically modified with a metal chelating group and then attached to the terminus of ss-DNA. This was combined with a complementary ss-DNA modified with another fluorescent dye (ATTO 590), emitting at a longer wavelength. In the assembled duplex, fluorescence resonance energy transfer (FRET) between the fluorescein donor (excited at 470 nm) and the ATTO 590 acceptor (emitting at 624 nm) is observed. Proper positioning within the rigid DNA double helix prevents intramolecular contact quenching of the two dyes. Coordination of paramagnetic Cu(2+) ions by the chelating unit of the sensor results in direct fluorescence quenching of the fluorescein dye and indirect (by loss of FRET) quenching of the ATTO 590 emission at 624 nm. As a result, emission of the acceptor dye can be used for monitoring of the concentration of Cu(2+), with a 20 nM detection limit. The emission wavelength is readily tuned by replacement of ATTO-DNA by other commercially available DNA-acceptor dye conjugates. Fluorescent metal ion sensors emitting at >600 nm are very rare. The possibility of tuning the emission wavelength is important with respect to the optimization of this sensor type for application to biological samples, which usually show broad autofluorescence at <550 nm.

  9. Thermosensitive polymer-modified gold nanoparticles with sensitive fluorescent properties

    Science.gov (United States)

    Luo, Chunhua; Dong, Qiujing; Qian, Meijuan; Zhang, Hong

    2016-11-01

    Two types of thermosensitive polymer-modified gold nanoparticles (GNPs), P(DMAM-co-MADMAC)-modified GNPs (GNPs@PDM) and P(NIPAM-co-MADMAC)-modified GNPs (GNPs@PNM), are fabricated by the "grafting through" polymerization technique. The as-prepared GNPs are characterized by UV-vis, TEM, XPS, TGA, FT-IR and 1H NMR spectroscopy. The thermosensitivity and fluorescence of the GNPs are investigated. It is found that all GNPs aqueous solutions but GNPs@PDM1 exhibit thermosensitivity originated from thermosensitive polymer chains and sensitive fluorescence from the dimethylaminochalcone group. The lower critical solution temperature (LCST) of the GNPs decreases with the increasing content of MADMAC unit in the GNPs. The GNPs aqueous solution shows weak fluorescence after the temperature increases from 25 °C to 45 °C, or after β-cyclodextrin (β-CD) is added. Furthermore, it exhibits strong fluorescence when the solvent is changed to ethanol or chloroform, and the fluorescent wavelength undergoes a blue shift from ethanol to chloroform.

  10. Combining fluorescence and bioluminescence microscopy.

    Science.gov (United States)

    Goda, Kazuhito; Hatta-Ohashi, Yoko; Akiyoshi, Ryutaro; Sugiyama, Takashi; Sakai, Ikuko; Takahashi, Takeo; Suzuki, Hirobumi

    2015-08-01

    Bioluminescence microscopy has revealed that gene expression in individual cells can respond differently to the same stimulus. To understand this phenomenon, it is important to sequentially observe the series of events from cellular signal transduction to gene expression regulated by specific transcription factors derived from signaling cascades in individual cells. However, these processes have been separately analyzed with fluorescence and bioluminescence microscopy. Furthermore, in culture medium, the background fluorescence of luciferin-a substrate of luciferase in promoter assays of gene expression in cultured cells-confounds the simultaneous observation of fluorescence and bioluminescence. Therefore, we optimized conditions for optical filter sets based on spectral properties and the luciferin concentration based on cell permeability for fluorescence observation combined with bioluminescence microscopy. An excitation and emission filter set (492-506 nm and 524-578 nm) was suitable for green fluorescent protein and yellow fluorescent protein imaging of cells, and >100 μM luciferin was acceptable in culture medium based on kinetic constants and the estimated intracellular concentration. Using these parameters, we present an example of sequential fluorescence and bioluminescence microscopic observation of signal transduction (translocation of protein kinase C alpha from the cytoplasm to the plasma membrane) coupled with activation of gene expression by nuclear factor of kappa light polypeptide B in individual cells and show that the gene expression response is not completely concordant with upstream signaling following stimulation with phorbol-12-myristate-13-acetate. Our technique is a powerful imaging tool for analysis of heterogeneous gene expression together with upstream signaling in live single cells.

  11. [Integrated Development of Full-automatic Fluorescence Analyzer].

    Science.gov (United States)