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Sample records for atomic fluorescence spectrometric

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

    International Nuclear Information System (INIS)

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

  2. Chemotrapping-atomic fluorescence spectrometric method as a field method for volatile arsenic in natural gas.

    Science.gov (United States)

    Uroic, M Kalle; Krupp, Eva M; Johnson, Charlie; Feldmann, Jörg

    2009-12-01

    Volatile arsenic compounds in natural gas, existing in the form of trimethylarsine (TMAs), have been determined using gas cryo-trapping gas chromatography coupled to inductively coupled plasma-mass spectrometry (CT-GC-ICP-MS). The results from a number of different gas wells revealed a huge concentration spread ranging from below the detection limit of 0.2 up to 1800 microg/m(3) TMAs (as As) in the gas. Due to the toxicity and corrosive nature of these arsines, they need near real time monitoring via a method that can easily be implemented on site, i.e. during gas exploitation. Here, we introduce a novel method which utilises silver nitrate impregnated silica gel tubes for quantitative chemotrapping of trimethylarsine (TMAs) from a natural gas matrix. Subsequent elution with hot nitric acid followed by online photo-oxidation hydride generation atomic fluorescence spectrometry (HG-AFS) is used for the determination of TMAs gas standards in nitrogen and natural gas samples, respectively. The chemotrapping method was validated using CT-GC-ICP-MS as a reference method. The recovery of arsenic from nitrogen or natural gas matrix ranged from 85 to 113% for a range of 20 to 2000 ng As. Trapping efficiency was >98%, from the methods LOD of 20 ng to 4.8 microg (absolute amount As) with sample sizes of 0.02 and 2 L gas. Method performance was established by comparing the results obtained for eight natural gas samples containing between 1 and 140 microg As/m(3) with those achieved by the reference method (CT-GC-ICP-MS). PMID:20024020

  3. Instrumental modification intended to save time, and volumes of sample and reagent solutions, in the atomic fluorescence spectrometric determination of mercury.

    Science.gov (United States)

    Pérez-Sirvent, Carmen; Martínez-Sánchez, María J; García-Lorenzo, Mariluz; López-García, Ignacio; Hernández-Córdoba, Manuel

    2007-05-01

    Use of small membrane pumps, instead of peristaltic pumps, to introduce sample and reagent solutions into the spectrometer has several advantages in atomic fluorescence spectrometric determination of mercury. This simple modification results in a substantial saving in the time required for the measurements and so 90% of reagent solution volumes and 95% of sample solution volumes are saved, with a consequent decrease in the volume of waste generated. The sampling frequency is almost tripled, with no deterioration in sensitivity, which is similar to that obtained by use of peristaltic pumps. The relative standard deviation for ten consecutive measurements of a 1 microg L-1 mercury solution was approximately 2%. PMID:17351707

  4. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    Directory of Open Access Journals (Sweden)

    Hesham Salem

    2005-01-01

    Full Text Available Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate. The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed native fluorescence at 450 nm when excitation was at 290 nm. The calibration graph was rectilinear from 0.3-1.4 μg mL-1 (method I. Cobalt sulphate was used for precipitation of the ion associates formed from the reaction with the cited drugs. The formation and solubility of the solid complexes at the optimum conditions of pH and ionic strength values have been studied. The method depends on direct determination of the ions in the precipitate or indirect determination of the ions in the filtrate by atomic absorption spectroscopy. The optimum conditions for precipitation were carefully studied. Rectilinear calibration graphs were obtained in the range of 3-30 μg mL-1 for each of the investigated drugs. The molar ratios of the formed chelats were determined by Job's method and their association constants were also calculated (method II. Ammonium vanadate was used for the spectrophotometric determination of the selected fluoroquinolones by oxidation in sulphuric acid medium resulting in the development of a greenish blue colour measured at 766 nm which was attributed to the vanadium (IV produced by reduction of vanadium (V by the selected drugs. The optimum conditions for heating time, reagent concentration and sulphuric acid concentration were carefully studied. The accuracy and precision of the proposed method was confirmed by estimating five or six replicates within Beer's law limits were obtained in the range 10-40 μg mL-1 for each of the investigated drugs

  5. System for Gamma an X rays fluorescence spectrometric

    International Nuclear Information System (INIS)

    A system for spectrometry of gamma or fluorescence X rays is presented. It sis composed by a Si(Li) semiconductors detector, a charge sensitive preamplifier, a high voltage power supply, a spectrometric amplifier and a monolithic 1024 channels multichannel analyzers or an IBM compatible 4096 channels add - on- card multichannel analyzer. The system can be configured as a 1024 or 4096 channels gamma or fluorescent X rays spectrometer

  6. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    Science.gov (United States)

    Qin, Deyuan; Gao, Feng; Zhang, Zhaohui; Zhao, Liqian; Liu, Jixin; Ye, Jianping; Li, Junwei; Zheng, Fengxi

    2013-10-01

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3σ) with sample loadings of 10.0 mL was 0.03 ng L- 1 and 0.08 ng L- 1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples.

  7. Use of Ni/NixB Nanoparticles as a Novel Adsorbent for the Preconcentration of Mercury Species prior to Cold Vapor-Atomic Fluorescence Spectrometric Determination.

    Science.gov (United States)

    Yayayürük, Onur; Henden, Emür

    2016-01-01

    A selective matrix separation/enrichment method, utilizing a simple batch procedure with nickel/nickel boride (Ni/NixB) nanoparticles was proposed for the determination of inorganic mercury(II), Hg(2+) and methyl mercury(I), CH3Hg(+) in waters prior to cold vapor-atomic fluorescence spectrometry (CV-AFS). The Ni/NixB nanoparticles, were synthesized by the chemical reduction of Ni(II) to Ni/NixB. The novel adsorbent was selective to Hg(2+) and CH3Hg(+) species between pH values of 4 - 10. Both of the mercury species were recovered from the adsorbent using 1.0 mol L(-1) hot HNO3 with high efficiency. It was observed that the adsorbent selectively removed Hg(2+) and CH3Hg(+) from the bulk solution in the presence of several competitor ions (As(3+), Sb(3+), Pb(2+), Zn(2+), Cu(2+), Cd(2+) and Fe(3+)) with ≥96% adsorption. The limit of detection (3σ above blank) was found to be 1.8 ng L(-1) with a preconcentration factor of 20. The validation of the method was tested through spike recovery experiments with several water samples (tap and seawater) at μg L(-1) concentration levels, and all recovery values were found to vary between 95 and 105%. PMID:27506713

  8. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    International Nuclear Information System (INIS)

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3σ) with sample loadings of 10.0 mL was 0.03 ng L−1 and 0.08 ng L−1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples. - Graphical abstract: An interference free ultraviolet vapor generation based method was applied to determine ultratrace mercury in water sample. - Highlights: • Hg was enriched by on-line solid phase extraction. • Hg was detected by ultraviolet vapor generation AFS. • The interference of some anion and some organics was removed. • The effects of details of UV set were systemically discussed

  9. Speciation and subcellular location of Se-containing proteins in human liver studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and hydride generation-atomic fluorescence spectrometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chunying; Zhao, Jiujiang; Zhang, Peiqun; Chai, Zhifang [Institute of High Energy Physics and Laboratory of Nuclear Analytical Techniques, Chinese Academy of Sciences, Beijing (China)

    2002-02-01

    Speciation of Se-containing proteins in the subcellular fractions of human liver was studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by hydride generation-atomic fluorescence spectrometric (HG-AFS) detection. It was found that about 24 kinds of Se-containing proteins existed in subcellular fractions of normal human liver. The molecular weights (MW) of the subunits were mostly in the range 20-30 kDa and 50-80 kDa. Major Se-containing protein fractions at 61 kDa and 21 kDa are probably selenoprotein P and glutathione peroxidase, respectively. The 54 kDa protein is probably a thioredoxin reductase, which is presented in nuclei, mitochondria, lysosome, microsome and cytosol. We noticed that the Se-containing protein with the lowest MW of 9.3 kDa only existed in lysosome. Most of the proteins have not been identified and would require further investigation to characterize them. The specific subcellular distributions of different Se-containing proteins suggest that they could play important biological roles in each organelle. (orig.)

  10. Spectrofluorimetric, Atomic Absorption Spectrometric and Spectrophotometric Determination of Some Fluoroquinolones

    OpenAIRE

    Hesham Salem

    2005-01-01

    Simple, accurate, sensitive and selective spectrofluorimetric, atomic absorption spectrometric and spectrophotometric methods are described for the quantitative determination of ten fluoroquinolones (amifloxacin, ciprofloxacin hydrochloride, difloxacin hydrochloride, enoxacin, enrofloxacin, lomefloxacin hydrochloride, levofloxacin, norfloxacin, ofloxacin and pefloxacin mesylate). The first method was a spectrofluorimetric method in which samples of the studied drugs in 0.1 N H2SO4 showed nati...

  11. Electrothermal atomization atomic absorption spectrometric determination of trace metals in uranium-plutomium fuel materials

    International Nuclear Information System (INIS)

    Atomic absorption spectrometric methods using the electrothermal mode of atomization developed for the determination of Ag, Be, Ca, Cd, Cr, Co, Cu, Fe, Li, Mn, Na, Ni, Sn and Zn in (U, Pu) solution with 4% plutonium have been described. The carbon rod atomizer has been adapted for glove box operation to enable handling of plutonium containing solution samples. Multielement solution standards with graded concentrations of the analytes and fixed concentration of the matrix are used in the standardization process. Nanogram to sub-nanogram quantities of the analytes have been determined with a precision of better than 9% RSD using 5 μl of the sample aliquots. (orig.)

  12. Atomic absorption spectrometric determination of mineral elements in mammalian bones

    International Nuclear Information System (INIS)

    The phosphorus content of the major bones of male and female selected mammals was determined using the yellow vanadomolybdate colorimetric method. For each animal, the bone with the highest phosphorus content was used as pilot sample. Varying concentrations of strontium were added to solutions of the ashed pilot samples to minimize phosphorus interference in the determination of calcium and magnesium using flame atomic absorption spectrophotometry operated on the air-acetylene mode. At least 6,000 ppm (0.6%) of strontium was required to give optimum results for calcium. The amount of magnesium obtained from the analysis was not affected by the addition of strontium. With the incorporation of strontium in the sample solution, all elements of interest can be determined in the same sample solution. Based on this, a procedure is proposed for the determination of calcium and other elements in bones. Average recoveries of spiked calcium and magnesium were 97.85% and 98.16%, respectively at the 95% confidence level. The coefficients of variation obtained for replicate determinations using one of the samples were 0.00% for calcium, lead and sodium, 2.93% for magnesium, 3.27% for iron and 3.92% for zinc at the concentration levels found in that sample. Results from the proposed procedure compared well with those from classical chemical methods at the 95% confidence level. It is evident that calcium phosphorus, magnesium and sodium which are the most abundant elements in the bones are distributed in varying amounts both in the different types of bones and different animal species, although the general trend is Ca > P > Na > Mg for each bone considered. The calcium - phosphorus ratio is generally 3:1. The work set out to propose an atomic absorption spectrometric method for the multi-element analysis of mammalian bones with a single sample preparation and to study the distribution pattern of these elements in the bones. (Author)

  13. The accuracy of X-ray fluorescence spectrometric determination of Rb and Sr contents in rock sample

    International Nuclear Information System (INIS)

    It is shown that application of the Compton scattering method in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide element contents at an accuracy level +- 1 %

  14. Imaging an atomic beam using fluorescence

    Institute of Scientific and Technical Information of China (English)

    Ming He(何明); Jin Wang(王谨); Mingsheng Zhan(詹明生)

    2003-01-01

    A fluorescence detection scheme is applied to image an atomic beam. Using two laser diodes as the sources of detection light and pumping light respectively, the fluorescence image of the atomic beam is then observed by a commercial CCD-camera, which is corresponding to the atomic state and velocity distribution. The detection scheme has a great utilization in the experiments of cold atoms and atomic optics.

  15. Speciation and detection of arsenic in aqueous samples: A review of recent progress in non-atomic spectrometric methods

    International Nuclear Information System (INIS)

    Highlights: • Compilation of principal official documents and major review articles, including the toxicology and chemistry of As. • Review of non-atomic spectrometric methods for speciation and detection of arsenic in aqueous samples (2005–2013) of the performance of field-usable methods. - Abstract: Inorganic arsenic (As) displays extreme toxicity and is a class A human carcinogen. It is of interest to both analytical chemists and environmental scientists. Facile and sensitive determination of As and knowledge of the speciation of forms of As in aqueous samples are vitally important. Nearly every nation has relevant official regulations on permissible limits of drinking water As content. The size of the literature on As is therefore formidable. The heart of this review consists of two tables: one is a compilation of principal official documents and major review articles, including the toxicology and chemistry of As. This includes comprehensive official compendia on As speciation, sample treatment, recommended procedures for the determination of As in specific sample matrices with specific analytical instrument(s), procedures for multi-element (including As) speciation and analysis, and prior comprehensive reviews on arsenic analysis. The second table focuses on the recent literature (2005–2013, the coverage for 2013 is incomplete) on As measurement in aqueous matrices. Recent As speciation and analysis methods based on spectrometric and electrochemical methods, inductively coupled plasma-mass spectrometry, neutron activation analysis and biosensors are summarized. We have deliberately excluded atomic optical spectrometric techniques (atomic absorption, atomic fluorescence, inductively coupled plasma-optical emission spectrometry) not because they are not important (in fact the majority of arsenic determinations are possibly carried out by one of these techniques) but because these methods are sufficiently mature and little meaningful innovation has been

  16. Accuracy of X-ray fluorescence spectrometric determination of Rb and Sr concentrations in rock samples

    International Nuclear Information System (INIS)

    It is shown that application of the Compton scattering for matrix correction in the X-ray fluorescence spectrometric determination of the trace elements Rb and Sr in rock samples can provide concentrations at a relative accuracy level of 1%. The empirical method applies to rock samples showing differences in mass absorption up to a factor of two. The accuracy of the method has been tested by analysis of 57 samples analysed for Rb and Sr by mass spectrometric isotope dilution. In addition a few of the U.S. Geological Survey reference rock powders, showing significantly different mass absorption, were analysed for Rb and Sr. It is demonstrated that the mica effect, if significant, is smaller than 1% relative. There is no advantage in the use of the LiF(220) analysing crystal as a substitute for the LiF(200). The method appears to be insensitive to the pellet thickness. (author)

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

    Directory of Open Access Journals (Sweden)

    Issa M

    2008-01-01

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

  18. Uranium determination using atomic spectrometric techniques: An overview

    International Nuclear Information System (INIS)

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

  19. Synthesis, purification and mass spectrometric characterisation of a fluorescent Au9@BSA nanocluster and its enzymatic digestion by trypsin

    Science.gov (United States)

    Fernández-Iglesias, Nerea; Bettmer, Jörg

    2013-12-01

    Nanoclusters of noble metals like Ag and Au have attracted great attention as they form a missing link between isolated metal atoms and nanoparticles. Their particular properties like luminescence in the visible range and nontoxicity make them attractive for bioimaging and biolabelling purposes, especially with use of proteins as stabilising agents. In this context, this study intends the synthesis of a specific Au nanocluster covered by bovine serum albumin (BSA). It is shown that size-exclusion chromatography is feasible for the purification and isolation of the nanocluster. A mass spectrometric characterisation, preferably by ESI-MS, indicates the presence of an Au9@BSA nanocluster. Enzymatic digestion of the nanocluster with trypsin results in a significant increase of the fluorescence intensity at 650 and 710 nm, whereas complementary MALDI-MS studies are presented for the identification of generated peptides and show a distinctive pattern in comparison to the pure protein. It can be concluded that Au9@BSA might be, in future, an interesting candidate for in vitro studies of protease activities.Nanoclusters of noble metals like Ag and Au have attracted great attention as they form a missing link between isolated metal atoms and nanoparticles. Their particular properties like luminescence in the visible range and nontoxicity make them attractive for bioimaging and biolabelling purposes, especially with use of proteins as stabilising agents. In this context, this study intends the synthesis of a specific Au nanocluster covered by bovine serum albumin (BSA). It is shown that size-exclusion chromatography is feasible for the purification and isolation of the nanocluster. A mass spectrometric characterisation, preferably by ESI-MS, indicates the presence of an Au9@BSA nanocluster. Enzymatic digestion of the nanocluster with trypsin results in a significant increase of the fluorescence intensity at 650 and 710 nm, whereas complementary MALDI-MS studies are presented

  20. Vapor generation – atomic spectrometric techniques. Expanding frontiers through specific-species preconcentration. A review

    Energy Technology Data Exchange (ETDEWEB)

    Gil, Raúl A.; Pacheco, Pablo H.; Cerutti, Soledad [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Martinez, Luis D., E-mail: ldm@unsl.edu.ar [Área de Química Analítica, Facultad de Química Bioquímica y Farmacia, Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina); Instituto de Química de San Luis, INQUISAL, Centro Científico-Tecnológico de San Luis (CCT-San Luis), Consejo Nacional de Investigaciones Científicas y Universidad Nacional de San Luis, Ciudad de San Luis 5700 (Argentina)

    2015-05-22

    This article reviews 120 articles found in SCOPUS and specific Journal cites corresponding to the terms ‘preconcentration’; ‘speciation’; ‘vapor generation techniques’ and ‘atomic spectrometry techniques’ in the last 5 years. - Highlights: • Recent advances in vapor generation and atomic spectrometry were reviewed. • Species-specific preconcentration strategies after and before VG were discussed. • New preconcentration and speciation analysis were evaluated within this framework. - Abstract: We review recent progress in preconcentration strategies associated to vapor generation techniques coupled to atomic spectrometric (VGT-AS) for specific chemical species detection. This discussion focuses on the central role of different preconcentration approaches, both before and after VG process. The former was based on the classical solid phase and liquid–liquid extraction procedures which, aided by automation and miniaturization strategies, have strengthened the role of VGT-AS in several research fields including environmental, clinical, and others. We then examine some of the new vapor trapping strategies (atom-trapping, hydride trapping, cryotrapping) that entail improvements in selectivity through interference elimination, but also they allow reaching ultra-low detection limits for a large number of chemical species generated in conventional VG systems, including complete separation of several species of the same element. This review covers more than 100 bibliographic references from 2009 up to date, found in SCOPUS database and in individual searches in specific journals. We finally conclude by giving some outlook on future directions of this field.

  1. Ultrasound-assisted emulsification of cosmetic samples prior to elemental analysis by different atomic spectrometric techniques.

    Science.gov (United States)

    Lavilla, I; Cabaleiro, N; Costas, M; de la Calle, I; Bendicho, C

    2009-11-15

    In this work, ultrasound-assisted emulsification with a probe system is proposed as a rapid and simple sample treatment for atomic spectrometric determinations (Electrothermal Atomic Absorption Spectrometry, Inductively Coupled Plasma Optical Emission Spectrometry, Flame Atomic Absorption Spectrometry and Cold Vapour Atomic Absorption Spectrometry) of trace elements (As, Cd, Cr, Cu, Hg, Mg, Mn, Ni, Sr and Zn) in cosmetic samples such as shampoos, gel (hair gel), crèmes (body milk, hair conditioner) and oil (body oil). The type of dispersion medium, the sample mass-to-dispersion medium volume ratio, as well as the parameters related to the ultrasound-assisted emulsification (sonication amplitude and treatment time) were exhaustively studied. Only 1 min of ultrasonic shaking and a dispersion medium containing 0.5% (w/v) of SDS+3% (v/v) of HNO(3) or HCl allows obtaining a stable emulsion at least for 3 months. Thermal programs, nebulization of emulsions, speed of pumps and concentration of reagents used in cold vapour generation were optimized. Calibration using aqueous standards was feasible in all cases. Calibration by the standard addition method and recovery studies was also applied for validation. Microwave-assisted digestion and Inductively Coupled Plasma Mass Spectrometry were used for comparison purposes. Relative standard deviations from analysis of five independent emulsions were less than 9% in all cases. PMID:19782199

  2. On the reliability of methods for the speciation of mercury based on chromatographic separation coupled to atomic spectrometric detection

    OpenAIRE

    Qvarnström, Johanna

    2003-01-01

    This thesis deals with the reliability of methods for the speciation of mercury in environmental and biological samples. Problems with speciation methods that couple chromatography to atomic spectrometric detection and how to overcome the problems are discussed. Analytical techniques primarily studied and evaluated are high performance liquid chromatography-cold vapour-atomic absorption spectrometry (HPLC-CV-AAS), HPLC-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS), capillary elec...

  3. Laser fluorescence spectroscopy of sputtered uranium atoms

    International Nuclear Information System (INIS)

    Laser induced fluorescence (LIF) spectroscopy was used to study the sputtering of 99.8% 238U metal foil when bombarded by normally incident 500 to 3000 eV Ne+, Ar+, Kr+, and O2+. A three-level atom model of the LIF processes is developed to interpret the observed fluorescent emission from the sputtered species. The model shows that close attention must be paid to the conditions under which the experiment is carried out as well as to the details of the collision cascade theory of sputtering. Rigorous analysis shows that when properly applied, LIF can be used to investigate the predictions of sputtering theory as regards energy distributions of sputtered particles and for the determination of sputtering yields. The possibility that thermal emission may occur during sputtering can also be tested using the proposed model. It is shown that the velocity distribution (either the number density or flux density distribution, depending upon the experimental conditions) of the sputtered particles can be determined using the LIF technique and that this information can be used to obtain a description of the basic sputtering mechanisms. These matters are discussed using the U-atom fluorescence measurements as a basis. The relative sputtering yields for various incident ions on uranium were also measured for the first time using the LIF technique. A surprisingly high fraction of the sputtered uranium atoms were found to occupy the low lying metastable energy levels of U(I). The population of the sputtered metastable atoms were found approximately to obey a Boltzman distribution with an effective temperature of 920 +- 1000K. 41 references

  4. Study on Arsenic/Selenium Speciation Analysis by a Modified High Sensitive Atomic Fluorescence Spectrometric System%高灵敏度原子荧光光谱系统应用于砷、硒形态分析的研究

    Institute of Scientific and Technical Information of China (English)

    张硕; 弓振斌

    2014-01-01

    将实验室自制的高灵敏度原子荧光光谱系统与色谱分离、在线紫外光前处理装置联用,实现了元素形态的液相色谱分离、在线紫外消解、蒸气发生及原子荧光光谱测定,并以砷、硒两元素为例对系统的分析性能进行研究。样品通过加热混旋提取、离心、过滤,使用反相色谱柱并以5.0 mmol/L磷酸氢二铵缓冲溶液(pH 5.7)-0.5 mmol/L四丁基溴化铵(TBAB)-1%甲醇为流动相进行分离;三价砷(AsO3-3)、二甲基砷( DMA)、一甲基砷( MMA)、五价砷( AsO3-4)可在7 min内进行分离和测定,硒代胱氨酸( SeCys)、硒代蛋氨酸( SeMet)、四价硒( SeO2-3)、六价硒( SeO2-4)的测定约需11 min。在优化实验条件下,方法检出限( DLs,S/N=3)为0.08~0.74μg/L;相对标准偏差( RSD,n=7)为1.4%~7.9%,实际样品的加标回收率为82.5%~116.5%;砷、硒各形态在0.28~40.0μg/L和0.38~80.0μg/L范围内线性良好。建立的联用系统稳定性好、检出限低,可实现样品中低浓度砷、硒形态的准确测定。%A self-mode labs high sensitive atomic fluorescence spectrometric detection system com-bined with liquid chromatography,online ultraviolet photochemical digesting and vapor generation de-vice was established and evaluated. Arsenic and selenium species in various samples were extracted by heating-shaking and centrifugal filtration. All the analytes were separated on a reversed-phase col-umn using mobile phase of 5. 0 mmol/L phosphate buffer(pH 5. 7)-0. 5 mmol/L tetrabutyl ammonium bromide(TBAB)-1% methanol. The separations of AsO3-3 ,DMA,MMA,AsO3-4 and SeCys,SeMet, SeO2-3 ,SeO2-4 were achieved within 7 min and 11 min,respectively. Under the optimized operating con-ditions,the detection limits(DLs,S/N=3)were in the range of 0. 08-0. 74 μg/L,and the relative standard deviations( RSD,n=7 )were 1. 4% -7. 9%. The standard spiked recoveries for real samples

  5. Separation of trace antimony and arsenic prior to hydride generation atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    A separation method utilizing a synthetic zeolite (mordenite) was developed in order to eliminate the gas phase interference of Sb(III) on As(III) during quartz furnace hydride generation atomic absorption spectrometric (HGAAS) determination. The efficiency of the proposed separation method in the reduction of suppression effects of transition metal ions on As(III) signal was also investigated. Among the volatile hydride-forming elements and their different oxidation states tested (Sb(III), Sb(V), Se(IV), Se(VI), Te(IV), and Te(VI)), only Sb(III) was found to have a signal depression effect even at low (μg l-1) concentrations under the experimental conditions employed. It has been shown that mordenite adsorbs Sb(III) quantitatively, even at a concentration of 1000 μg l-1, at pHs greater than two, and also, it reduces the initial concentrations of the transition metal ions to lower levels which can be tolerated in many studies. The adsorption of Sb(III) on mordenite follows the Freundlich isotherm and is endothermic in nature

  6. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    International Nuclear Information System (INIS)

    Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  7. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  8. Volatile species generation and atomization for atomic absorption and atomic fluorescence: new developments

    Czech Academy of Sciences Publication Activity Database

    Dědina, Jiří; Kratzer, Jan; Musil, Stanislav; Marschner, Karel; Matoušek, Tomáš; Svoboda, Milan; Mester, Z.; Sturgeon, R. E.; Talába, M.; Dvořák, P.

    2015. s. 41-41. [Colloquium Spectroscopicum Internationale /39./. 30.08.2015-03.09.2015, Figueira da Foz] R&D Projects: GA ČR GA14-23532S; GA MŠk LO1411 Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : hydride generation * volatile species generation * atomic absorption * atomic fluorescence Subject RIV: CB - Analytical Chemistry, Separation

  9. Manipulation of the atomic localization via resonance fluorescence

    International Nuclear Information System (INIS)

    The possibility of manipulating the position of atoms dressed in the standing field of the cavity, based on the resonance fluorescence emission, is discussed. Stark dynamics modification and the strong coupling between two undistinguishable radiators situated in non-symmetric positions of the anti-nodes are investigated. The fluorescent spectrum is shown versus the second atom localization and external field parameters. We describe the conditions in which the Rabi frequencies of atoms change their correlations and cooperative emission. (paper)

  10. X-ray fluorescence spectrometric and optical emission spectographic analysis of thoria in thoriated copper metal powder

    International Nuclear Information System (INIS)

    Two methods, one using the X-ray fluorescence (XRF) spectrometric technique and another using optical emission spectrographic (OES) technique are described for the determination of thoria in the concentration range 0.5-10% in thoriated copper metal powder. The precision of XRF method is superior to OES method but when sample quantity is very small, the OES method is useful. For XRF method, 500 mg sample is mixed with boric acid binding material and converted to a tablet for analysis. For OES method, only 200 mg sample is needed which is glued to the flat ends of two graphite electrodes for excitation by AC arc. The precision obtained in XRF is better than +-1% and in OES it is +-23%. (author)

  11. Chromatographic separation and inductively coupled plasma atomic emission spectrometric determination of the rare earth metals contained in terbium

    International Nuclear Information System (INIS)

    The chromatographic separation of rare earth elements (REEs), prior to inductively coupled plasma atomic emission spectrometric (ICP-AES) measurements, using a column packed with 2-ethylexyl hydrogen 2-ethyl-hexylphosphonate (PC-88A)-loaded polymer resin in order to exclude spectral interferences was examined. A favourable separation of trace amounts of metals (La, Nd and Sm) from a large amount of terbium was achieved simply by elution with dilute hydrochloric acid. Trace lanthanum and neodymium in metallic terbium were determined by separation of the analyte ions from the matrix element followed by ICP-AES analysis. (author). 16 refs.; 5 figs.; 2 tabs

  12. Atomic emission and atomic absorption spectrometric analysis of high-purity powders for the production of ceramics

    International Nuclear Information System (INIS)

    Direct analysis methods and multistage combined analytical procedures for the determination of impurities at the μg/g level and the upper ng/g level in high-purity powders of Al2O3, AlN, Si3N4 and SiC are described. Results obtained with a novel direct slurry-atomization technique using a Babington nebulizer and inductively coupled plasma optical emission spectrometry (ICP-OES) are presented. A comparison of analysis results of combined analytical procedures including wet chemical decomposition and determinations with graphite furnace atomic absorption spectrometry (ETAAS) or ICP-OES with those of slurry-atomization ICP-OES show the capabilities of this technique for routine analysis in production control. Detection limits for Al, B, Ca, Co, Cu, Fe, Mg, Mn, Si, Ti, W, V, and Zn in the matrices mentioned are between 0.03 and 2.5 μg/g. For elemental concentrations ≥10 μg/g relative standard deviations of the measurements are generally below 10%. The technique is shown to be a powerful tool for trace determinations in powder samples. This is shown by its use for analysis of a series of the ceramic powders mentioned and comparative results of other direct techniques such as total reflection X-ray fluorescence spectrometry and instrumental neutron activation analysis. (orig.)

  13. Vacuum ultraviolet laser induced fluorescence on a Si atomic beam

    Science.gov (United States)

    O'Brian, T. R.; Lawler, J. E.

    1991-01-01

    A broadly applicable vacuum ultraviolet experiment is described for measuring radiative lifetimes of neutral and singly-ionized atoms in a beam environment to 5-percent accuracy using laser induced fluorescence. First results for neutral Si are reported.

  14. 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

  15. Analyses of Heavy Metal Contents in the Bulk Atmospheric Aerosols Simultaneously Collected at Okinawa Archipelago, Japan by Using X-ray fluorescence spectrometric method (XRF)

    Science.gov (United States)

    Oshiro, Y.; ITOH, A.; Azechi, S.; Somada, Y.; Handa, D.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2012-12-01

    We studied heavy metal contents of bulk atmospheric aerosols using an X-ray fluorescence spectrometric method (XRF). The XRF method enables us to analyze heavy metal contents in the bulk aerosols rapidly without any chemical pretreatments. We used an energy dispersive X-ray fluorescence spectrometer that is compact and portable. We prepared several different amounts of standard reference materials (referred to "SRM", NIES No.28 of Japanese National Institute of Environmental Studies) on quartz filters for calibration curves in two different methods; 1) water-insoluble materials were collected after dispersing SRM in pure water and filtered with the quartz filters ("wet method"), and 2) SRM was dispersed in air in the plastic container and the aerosols were collected by using the low-volume air sampler ("dry method"). Good linear relationships between X-ray intensity and amount of aerosols on the filter were seen in the following 9 metals; Al, K, Ti, V, Fe, Ni, Rb, Ba, and Pb (with wet method) and 12 metals; K, Ti, Fe, Ni, Rb, Ba, Pb, Sr, Ca, Mn, Zn, and Cu (with dry method). Furthermore, we evaluated quantitative responses of XRF method by comparing with the metal contents determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after acid-digestion. We then used XRF method to determine heavy metal contents in authentic atmospheric aerosols collected in Okinawa islands, Japan. We simultaneously collected bulk aerosol samples by using identical high-volume air samplers at 3 islands; Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS). We report and discuss spatial and temporal distribution of heavy metals determined by the XRF method in the bulk atmospheric aerosols collected at the three islands during June 2008 to June 2010, and for CHAAMS during June 2008 to October 2012.

  16. Spectrometric scintillation units for gamma detection based on oxide scintillators with great atomic number

    International Nuclear Information System (INIS)

    Gamma-radiation detecting scintillation spectrometric units based on monocrystals of bismuth germanate (BGO) and cadmium tungstate (CWO) were developed to carry out express control of the environment migration of radionuclides. Detecting unit includes a BGO or CWO detector, FEU-176, supply voltage high-volt converter, amplifier-oscillator and differential discriminator to separate radionuclides. BGO base scintillation detecting unit with 40 x 40 mm dimensions has following parameters as to 137 Cs: amplitude resolution - 12.4%; recording efficiency - 45%; sensitivity - 0.004 pulse/Bq x s. The level of specific background with passive protection - 0.55 pulse/s

  17. Determination of rhenium in molybdenite by X-ray fluorescence. A combined chemical-spectrometric technique

    Science.gov (United States)

    Solt, M.W.; Wahlberg, J.S.; Myers, A.T.

    1969-01-01

    Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 ??g of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. ?? 1969.

  18. Determination of trace elements in Egyptian cane sugar (Deshna Factories) by neutron activation, atomic absorption spectrophotometric and inductively coupled plasma-atomic emission spectrometric analysis

    International Nuclear Information System (INIS)

    Multielement instrumental neutron activation (INAA), inductively coupled plasma-atomic emission spectrometric (ICP-AES) and atomic absorption spectrophotometric (AAS) analyses were utilized for the determination of Ag, Al, As, Au, Ba, Be, Br, Ca, Cd, Ce, Cl, Co, Cr, Cu, Eu, Fe, Ga, Hf, K, La, Li, Lu, Mg, Mn, Na, Nb, Ni, P, Pb, Sb, Sc, Se, Sm, Sn, Sr, Ta, Th, Ti, U, V, W and Zn in sugar cane plant, raw juice, juice in different stages, syrup, deposits, molasses, A, B and C sugar, refinery 1 and 2 sugar, and in soil samples picked up from the immediate vicinity of the cane plant roots at surface, 30 and 60 cm depth, respectively. (author)

  19. 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.

  20. Determination of rhenium in molybdenite by X-ray fluorescence: A combined chemical-spectrometric technique.

    Science.gov (United States)

    Solt, M W; Wahlberg, J S; Myers, A T

    1969-01-01

    Rhenium in molybdenite is separated from molybdenum by distillation of rhenium heptoxide from a perchloric-sulphuric acid mixture. It is concentrated by precipitation of the sulphide and then determined by X-ray fluorescence. From 3 to 1000 microg of rhenium can be measured with a precision generally within 2%. The procedure tolerates larger amounts of molybdenum than the usual colorimetric methods. PMID:18960464

  1. A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

    Directory of Open Access Journals (Sweden)

    Stefanie Wolfram

    2014-10-01

    Full Text Available Molecular probes are widely used tools in chemical biology that allow tracing of bioactive metabolites and selective labeling of proteins and other biomacromolecules. A common structural motif for such probes consists of a reporter that can be attached by copper(I-catalyzed 1,2,3-triazole formation between terminal alkynes and azides to a reactive headgroup. Here we introduce the synthesis and application of the new thiazole-based, azide-tagged reporter 4-(3-azidopropoxy-5-(4-bromophenyl-2-(pyridin-2-ylthiazole for fluorescence, UV and mass spectrometry (MS detection. This small fluorescent reporter bears a bromine functionalization facilitating the automated data mining of electrospray ionization MS runs by monitoring for its characteristic isotope signature. We demonstrate the universal utility of the reporter for the detection of an alkyne-modified small molecule by LC–MS and for the visualization of a model protein by in-gel fluorescence. The novel probe advantageously compares with commercially available azide-modified fluorophores and a brominated one. The ease of synthesis, small size, stability, and the universal detection possibilities make it an ideal reporter for activity-based protein profiling and functional metabolic profiling.

  2. Quantum beats in fluorescence for multi-level atomic system

    International Nuclear Information System (INIS)

    For Λ-type three-level atomic systems we have clarified using diagram that (1) it is impossible to observe quantum beats due to the ground state sublevels by measuring the time dependence of the fluorescence intensity, and (2) why it is physically possible to observe and how we can observe quantum beats in the ground state sublevels by using fluorescence. Generalization of the results shows that we can determine from which state (the ground state or the excited state) the quantum beats are originated. Analytical result is shown for four-level atomic systems.

  3. An atomic beam fluorescence locked magneto-optical trap for krypton atoms

    International Nuclear Information System (INIS)

    We report here an atomic beam loaded magneto-optical trap (MOT) for metastable krypton atoms in which the fluorescence signal from the atomic beam is used to lock the cooling laser frequency. The fluorescence signal is generated by exciting the metastable krypton atomic beam using a probe laser beam (i.e. part of the cooling laser beam) intersecting the atomic beam at an angle. A spectral shift in the fluorescence signal can be achieved by varying the angle between the probe laser beam and the atomic beam to obtain the desired frequency detuning to lock the cooling laser frequency. This has been used to optimize the number of cold atoms in the MOT. The dependence of the peak height and slope of the atomic beam fluorescence (ABF) locking signal on the RF power in the discharge tube and pressure in the observation chamber of the setup has been studied to correlate its effect on the number of atoms in the MOT. (paper)

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

    DEFF Research Database (Denmark)

    Sherson, Jacob; Weitenberg, Christof; Andres, Manuel;

    2010-01-01

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

  5. Characterizing optical dipole trap via fluorescence of trapped cesium atoms

    Institute of Scientific and Technical Information of China (English)

    LIU; Tao; GENG; Tao; YAN; Shubin; LI; Gang; ZHANG; Jing; WANG; Junmin; PENG; Kunchi; ZHANG; Tiancai

    2006-01-01

    Optical dipole trap (ODT) is becoming an important tool of manipulating neutral atoms. In this paper ODT is realized with a far-off resonant laser beam strongly focused in the magneto-optical trap (MOT) of cesium atoms. The light shift is measured by simply monitoring the fluorescence of the atoms in the magneto-optical trap and the optical dipole trap simultaneously. The advantages of our experimental scheme are discussed, and the effect of the beam waist and power on the potential of dipole trap as well as heating rate is analyzed.

  6. Atomic-spectrometric determination of lithium, sodium, potassium and strontium in high-pure scandium

    International Nuclear Information System (INIS)

    Determination of lithium, sodium and potassium in strontium by flame photometry with atomic-absorption spectrophotometer is described. Scandium effect on value of Li, K. Na analytical signal in flame is studied. It is shown, that the base understates analytical signals. Determination of strontium by flame photometry is impossible. Determination of strontium (1x10-13 kg/ml) by atomic-absorption method with electrothermal atomization is possible

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

    International Nuclear Information System (INIS)

    The present paper describes a method developed at Control Laboratory, NFC which includes prior separation of lithium and potassium from uranium matrix before their measurements. Solvent extraction, using Tri-n-Butyl Phosphate (TBP) in CCI4 followed by Tri-n-Octyl Phosphine Oxide (TOPO) in CCI4, is employed for prior separation of Li and K. The resultant aqueous solution was analyzed by Flame-Atomic Emission Spectrometric (AES) method. Solvent extraction conditions are optimized for measurement of Li and K in the same aliquot. Experimental conditions such as instrument calibration, flame condition, fuel flow, sample flow rate through nebulizer, burner height etc. are also optimized. Under the optimal condition the detection limits achieved for lithium is 0.02 ppm and 0.2 ppm for potassium. A RSD of ± 3 % for Li at 0.05 ppm and ± 4% for K at 1 ppm level has been achieved in this method. The results of lithium in the sample are compared with the values obtained by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Similarly, values of potassium are compared with Flame-Atomic Absorption Spectrometry (Flame-AAS) technique. The comparisons are in good agreement. The above method is simple, sensitive, reproducible and can be used for measurement of lithium and potassium in UO2 powder and pellets on regular basis

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

    Science.gov (United States)

    Levent, Abdulkadir; Sentürk, Zühre

    2010-09-01

    Colorimetric and atomic absorption spectrometric methods have been developed for the determination of mucolytic drug Ambroxol. These procedures depend upon the reaction of iron(III) metal ion with the drug in the presence of thiocyanate ion to form stable ion-pair complex which extractable chloroform. The red-coloured complex was determined either colorimetrically at 510 nm or by indirect atomic absorption spectrometry (AAS) via the determination of the iron content in the formed complex. The optimum experimental conditions for pH, concentrations of Fe(3+) and SCN(-), shaking time, phase ratio, and the number of extractions were determined. Under the proposed conditions, linearity was obeyed in the concentration ranges 4.1x10(-6) - 5.7x10(-5) M (1.7-23.6 µg mL(-1)) using both methods, with detection limits of 4.6x10(-7) M (0.19 µg mL(-1)) for colorimetry and 1.1x10(-6) M (0.46 µg mL(-1)) for AAS. The proposed methods were applied for the determination of Ambroxol in tablet dosage forms. The results obtained were statistically analyzed and compared with those obtained by applying the high-performance liquid chromatographic method with diode-array detection. PMID:20426742

  9. Characterization of Heavy Metal Contents in the Bulk Atmospheric Aerosols Simultaneously Collected at Three Islands in Okinawa, Japan by X-ray fluorescence spectrometric method (XRF)

    Science.gov (United States)

    Oshiro, Y.; ITOH, A.; Azechi, S.; Somada, Y.; Handa, D.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

    2011-12-01

    We studied heavy metal contents of atmospheric aerosols using an X-ray fluorescence spectrometric method (XRF). The XRF method enables us to analyze heavy metal contents of bulk aerosols rapidly without any chemical pretreatments. We used an energy dispersive X-ray fluorescence spectrometer that is compact and portable. We prepared several different amounts of standard reference materials (NIES No.28) of Japanese National Institute of Environmental Studies on quartz filters for calibration curves. Then, we evaluated quantitative responses of XRF method by comparing with the metal contents determined by inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS) after acid-digestion. Good linear relationships between X-ray intensity and amount of aerosol on filter were seen in the following 10 metals; Al, K, Ti, V, Fe, Ni, Rb, Ba, Pb and As. We then used XRF method to determine heavy metal contents in authentic atmospheric aerosols collected in Okinawa islands, Japan. Okinawa islands, consisting of many small islands, are situated east of Asian continent, and its location in Asian is well suited for studying long-range transport of air pollutants. Also, in Okinawa islands, maritime air mass prevails during summer, while Asian continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air mass which has been affected by anthropogenic activities such as industries and automobiles. Therefore, Okinawa region is suitable area for studying impacts of air pollutants from East Asia. We simultaneously collected bulk aerosol samples by using identical high-volume air samplers at 3 islands; Cape Hedo Atmospheric Aerosol Monitoring Station (CHAAMS, Okinawa island), Kume island (ca. 160 km south-west of CHAAMS), and Minami-Daitou island (ca. 320 km south-east of CHAAMS). We report and discuss spatial and temporal distribution of heavy metals

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

    International Nuclear Information System (INIS)

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

  11. Development of temperature imaging using two-line atomic fluorescence.

    Science.gov (United States)

    Medwell, Paul R; Chan, Qing N; Kalt, Peter A M; Alwahabi, Zeyad T; Dally, Bassam B; Nathan, Graham J

    2009-02-20

    This work aims to advance understanding of the coupling between temperature and soot. The ability to image temperature using the two-line atomic fluorescence (TLAF) technique is demonstrated. Previous TLAF theory is extended from linear excitation into the nonlinear fluence regime. Nonlinear regime two-line atomic fluorescence (NTLAF) provides superior signal and reduces single-shot uncertainty from 250 K for conventional TLAF down to 100 K. NTLAF is shown to resolve the temperature profile across the stoichiometric envelope for hydrogen, ethylene, and natural gas flames, with deviation from thermocouple measurements not exceeding 100 K, and typically ≲30 K. Measurements in flames containing soot demonstrate good capacity of NTLAF to exclude interferences that hamper most two-dimensional thermometry techniques. PMID:23567586

  12. Solvent effects on two-line atomic fluorescence of indium.

    Science.gov (United States)

    Chan, Qing N; Medwell, Paul R; Kalt, Peter A M; Alwahabi, Zeyad T; Dally, Bassam B; Nathan, Graham J

    2010-03-10

    We aim to investigate the potential of four different organic solvents, namely, acetone, ethanol, methanol, and isopropanol, and the organic-solvent-water mixtures as a seeding medium for the two-line atomic fluorescence technique. Water is used as the reference case. Indium, which has been previously shown to have suitable spectroscopic attributes, is chosen as the thermometry species in the present study. Acetone and methanol are shown to enhance the fluorescence signal intensity the most (approximately threefold to fivefold at stoichiometric conditions) when used. Acetone and methanol are shown to improve the fluorescence emission over the entire stoichiometric envelope of flame, most significantly in the rich combustion region, as well as a twofold enhancement in the signal-to-noise ratio. PMID:20220881

  13. Atomic-absorption spectrometric determination of cobalt, nickel, and copper in geological materials with matrix masking and chelation-extraction

    Science.gov (United States)

    Sanzolone, R.F.; Chao, T.T.; Crenshaw, G.L.

    1979-01-01

    An atomic-absorption spectrometric method is reported for the determination of cobalt, nickel, and copper in a variety of geological materials including iron- and manganese-rich, and calcareous samples. The sample is decomposed with HP-HNO3 and the residue is dissolved in hydrochloric acid. Ammonium fluoride is added to mask iron and 'aluminum. After adjustment to pH 6, cobalt, nickel, and copper are chelated with sodium diethyl-dithiocarbamate and extracted into methyl isobutyl ketone. The sample is set aside for 24 h before analysis to remove interferences from manganese. For a 0.200-g sample, the limits of determination are 5-1000 ppm for Co, Ni, and Cu. As much as 50% Fe, 25% Mn or Ca, 20% Al and 10% Na, K, or Mg in the sample either individually or in various combinations do not interfere. Results obtained on five U.S. Geological Survey rock standards are in general agreement with values reported in the literature. ?? 1979.

  14. Atomic absorbtion spectrometric determination of platinum, palladium and rhodium in catalysts for automotive exhaust

    International Nuclear Information System (INIS)

    Analytical parameters of the electrothermal atomic absorption spectrometry method have been optimized for determination of platinum, palladium and rhodium in ceramic-supported catalysts for automobile exhaust gas treatment. Two chemical sample preparation methods have been proposed. In order to simplify the sample preparation procedure and to prevent the possible losses of platinum group metals the treatment of the previously ground sample with a mixture of mineral acids is recommended. (authors)

  15. Atomic-absorption spectrometric determination of trace metals in zirconium and zircaloy by discrete sample nebulization

    International Nuclear Information System (INIS)

    A discrete sample nebulization technique was employed to determine trace metals in nuclear grade zirconium and Zircaloy by flame atomic-absorption spectrometry. With 10% (w/v) sample solutions, detection limits for Cd, Cu, Mn, Ni and Pb were 0.6, 2, 1, 3, and 10 μg/g. Micro standard-addition procedures and background correction were employed to minimize matrix interferences produced by the high salt content of the aspirated solutions. (author)

  16. Studies in atomic-fluorescence spectroscopy-V The fluorescence characteristics and determination of antimony.

    Science.gov (United States)

    Dagnall, R M; Thompson, K C; West, T S

    1967-10-01

    Atomic-fluorescence of antimony may be generated in an air-propane flame by nebulizing aqueous solutions of antimony salts whilst irradiating the flame by means of a microwave-excited electrode-less discharge tube operating at 30 W. The strongest fluorescence is exhibited by the (4)S(11 2 ) --> (4)P(1 3 ) 2311 A resonance line and weaker signals are observed at the 2068 and 2176 A resonance lines and at four intercombination lines, at 2598, 2671, 2770 and 2878 A. A process of thermally assisted direct-line fluorescence is postulated to account for the otherwise inexplicable intensity of the 2598 A line emission. Atomic-fluorescence spectroscopy at 2176 A permits the determination of antimony in the range 0.1-120 ppm with a detection limit of 0.05 ppm. With the same equipment and source, the range of measurement for atomic-absorption was 6-120 ppm and the detection limit was 1 ppm. No interferences were observed from 100-fold molar amounts of Cd, Co, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, NH(4), Pb and Zn or from arsenate, chloride, nitrate, phosphate and sulphate. PMID:18960212

  17. Atomic Absorption Spectrometric Method for Estimation of Diclofenac sodium and Mefenamic acid in Pharmaceutical Formulations

    Directory of Open Access Journals (Sweden)

    Sunil Jawla

    2010-01-01

    Full Text Available Diclofenac sodium and Mefenamic acid have been quantified in tablet dosage form by atomic absorption spectrometry (AAS. These methods are based on formation of the metal complexes of Diclofenac sodium and Mefenamic acid with cupric chloride and cobaltous chloride. The first method is based on reaction of both the drugs with cupric chloride to give light blue colored metal complexes, which are then extracted with dichloromethane and digested with 0.1 M nitric acid. Both the drugs are indirectly estimated via determination of copper content in the formed complexes by AAS. The second method is based on the formation of pink colored complexes of both the drugs with cobaltous chloride. These metal complexes are extracted with dichloromethane and estimated via determination of cobalt content in the formed complexes after digestion with 0.1 M nitric acid by AAS.

  18. Microwave plasma atomic emission spectrometric determination of Ca, K and Mg in various cheese varieties.

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-02-01

    Microwave plasma-atomic emission spectrometry (MP-AES) was used to determine calcium, magnesium and potassium in various Turkish cheese samples. Cheese samples were dried at 100 °C for 2 days and then digested in a mixture of nitric acid/hydrogen peroxide (3:1). Good linearities (R(2) > 0.999) were obtained up to 10 μg mL(-1) of Ca, Mg and K at 445.478 nm, 285.213 nm and 766.491 nm, respectively. The analytes in a certified reference milk powder sample were determined within the uncertainty limits. Moreover, the analytes added to the cheese samples were recovered quantitatively (>90%). All determinations were performed using aqueous standards for calibration. The LOD values for Ca, Mg and K were 0.036 μg mL(-1), 0.012 μg mL(-1) and 0.190 μg mL(-1), respectively. Concentrations of Ca, K and Mg in various types of cheese samples produced in different regions of Turkey were found between 1.03-3.70, 0.242-0.784 and 0.081-0.303 g kg(-1), respectively. PMID:26304350

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

    Directory of Open Access Journals (Sweden)

    MAHMOUD MOHAMED ISSA

    2008-05-01

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

  20. EFFECT OF PH AND TIME ON CALCIUM RELEASE FROM SOUND ENAMEL: AN ATOMIC SPECTROMETRIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Shetty Shishir

    2013-06-01

    Full Text Available Dental Caries is a disease of great concern which affects people of all races in all places, the exact etiology of caries though unknown; it is well established that the release of calcium and phosphate from hydroxyapatite crystal is due to decreased pH of saliva. However the relationship between calcium release, pH and time is not well documented.The present study was designed to assess the calcium release from intact enamel when subjected to different pH at different time intervals. The enamel samples were subjected to acid challenge using Acetate buffer of pH of 3.5, 4, 4.5, 5, 5.5, 6 and 6.5 and buffer solution were analyzed for calcium release at specific time intervals for each pH using atomic absorption spectrometry. The results show that the rate of calcium release significantly increased from pH 5.0 to 3.5, however the calcium release was very little in pH 5.5 to 6.5. From the observations made from this study we can conclude that sound enamel is resistant to acid attack between pH of 5 to 5.5 and Time plays an important role in the reaction of enamel to acid.

  1. Trace elements in airborne particles in internal industrial environments: spectrometric analysis of x-ray fluorescence (XRF)

    International Nuclear Information System (INIS)

    Fluorescence spectroscopy x-ray, is a technique of non-destructive analysis, that allows quantitative determination of the absolute concentration of chemical elements that make up a given matrix. The detected elements depend on atomic number and energy of the secondary target used for irradiation of samples. X-rays are detected and counted in a spectroscopy system based on a multichannel analyzer, that discriminates by energy and form a spectrum of independent photopeaks, whose energy identifies the element and its intensity is proportional to its concentration. The quantification requires the irradiation and counting of a set of pattern comparators, of the same elements identified in the samples. The x-ray emission shows only during the time that the selected sample is subjected to irradiation by x-ray tube. This irradiation does not change the structure nor the chemical composition of the matrix, so the sample remains unchanged, after irradiation. This condition non-destructive characterizes the fluorescence x-ray. The trace elements present in airborne particles, are determined and collected on a Nuclepore filter. The collection sites selected are: Taller de Mecanica de Precision de la Escuela de Fisica, Universidad de Costa Rica; Taller J. V. G. Precision, San Antonio de Coronado; Taller de Muflas, MUFLASA, Alto de Guadalupe; Industria Silvania S. A., Pavas. In addition, it is attached the service rendered to the enterprise Sellos Generales S. A. The working conditions and physical conditions of facilities were considered. An aerosol sampler with a temporal variation was used. Irradiation of samples and an evaluation of the concentrations have been made. (author)

  2. Fluorescence detection at the atom shot noise limit for atom interferometry

    CERN Document Server

    Rocco, Emanuele; Valenzuela, Tristan; Boyer, Vincent; Freise, Andreas; Bongs, Kai

    2014-01-01

    Atom interferometers are promising tools for precision measurement with applications ranging from geophysical exploration to tests of the equivalence principle of general relativity, or the detection of gravitational waves. Their optimal sensitivity is ultimately limited by their detection noise. We review resonant and near-resonant methods to detect the atom number of the interferometer outputs and we theoretically analyze the relative influence of various scheme dependent noise sources and the technical challenges affecting the detection. We show that for the typical conditions under which an atom interferometer operates, simultaneous fluorescence detection with a CCD sensor is the optimal imaging scheme. We extract the laser beam parameters such as detuning, intensity, and duration, required for reaching the atom shot noise limit.

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

    International Nuclear Information System (INIS)

    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 compared. Under optimum conditions sensitivity obtained with flame-in-gas-shield atomizer was approximately twice higher than with miniature diffusion flame. The additional advantage of flame-in-gas-shield atomizer is significantly lower flame emission resulting in a better signal to noise ratio. The resulting arsenic limits of detection for miniature diffusion flame and flame-in-gas-shield atomizer were 3.8 ng l−1 and 1.0 ng l−1, respectively. - Highlights: • We optimized and compared two hydride atomizers for atomic fluorescence spectrometry. • Miniature diffusion flame and flame-in-gas-shield atomizer were optimized. • The limit of detection for arsenic was 1.0 ng l−1

  4. Titanium atom detection by resonance fluorescence excited with a nitrogen laser

    International Nuclear Information System (INIS)

    Coincidence of wave lengths of nitrogen laser basing lines and resonance transitions in titanium atom is investigated. It is shown that resonance fluorescence excited by nitrogen laser can be used for absolute titanium atom density measurements. Experiments on titanium atom detection in a vapour cloud formed under irradiation of a titanium target in vacuum by dye laser pulse, are conducted. Fluorescence extinguishing is observed under high evaporation power

  5. Laser-induced fluorescence detection strategies for sodium atoms and compounds in high-pressure combustors

    Science.gov (United States)

    Weiland, Karen J. R.; Wise, Michael L.; Smith, Gregory P.

    1993-01-01

    A variety of laser-induced fluorescence schemes were examined experimentally in atmospheric pressure flames to determine their use for sodium atom and salt detection in high-pressure, optically thick environments. Collisional energy transfer plays a large role in fluorescence detection. Optimum sensitivity, at the parts in 10 exp 9 level for a single laser pulse, was obtained with the excitation of the 4p-3s transition at 330 nm and the detection of the 3d-3p fluorescence at 818 nm. Fluorescence loss processes, such as ionization and amplified spontaneous emission, were examined. A new laser-induced atomization/laser-induced fluorescence detection technique was demonstrated for NaOH and NaCl. A 248-nm excimer laser photodissociates the salt molecules present in the seeded flames prior to atom detection by laser-induced fluorescence.

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

    International Nuclear Information System (INIS)

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

  7. Validation of a method to the addition the multiple standard in the analysis of Pb in reservoir waters for atomic absorption spectrometric

    International Nuclear Information System (INIS)

    The evaluation of a method is presented for the analysis of Pb in reservoir waters for atomic spectrometric with direct aspiration. For the validation of the analytic method a level of concentration of 0.05 mg/L was evaluated. The precision of the method was of 9.97% and the bias was 0.6% 8 samples of surface waters they were collected and of bottom of the tributaries of the reservoir Scorpions and the stocking of the concentrations in the tributaries was from 0,052 +- 0.026 inferior mg/L to the established one in the Cuban norm of evaluation of the hydirc objects of fishing use

  8. Influence of angle's ranges for recording an X-ray fluorescence hologram on reconstructed atomic images

    Institute of Scientific and Technical Information of China (English)

    XIE Hong-Lan; CHEN Jian-Wen; GAO Hong-Yi; ZHU Hua-Feng; LI Ru-Xin; XU Zhi-Zhan

    2004-01-01

    X-ray fluorescence holography (XFH) is a novel method for three-dimensional (3D) imaging of atomic structure. Theoretically, in an XFH experiment, one has to measure the fluorescence energy on a spherical surface to get well-resolved 3D images of atoms. But in practice, the experimental system arrangement does not allow the measurement of the fluorescent intensity oscillations in the full sphere. The holographic information losses because of the limited sampling range (less than 4π) will directly result in defective reconstructed atomic images. In this work, the atomic image of a Fe single crystal (001) was reconstructed by numerically simulating X-ray fluorescence holograms of the crystal at different recording angle's ranges and step lengths. Influences of the ranges of azimuth angles and polar angles and the step length of polar angles on the reconstructed atomic images were discussed.

  9. Energy dispersive x-ray fluorescence spectrometric determination of vanadium, nickel, and iron in petroleum and petroleum residua

    International Nuclear Information System (INIS)

    Trace metals such as vanadium, nickel, and iron in fluid catalytic cracking feedstocks deposit on the catalyst and adversely affect catalyst activity and product yields. Vanadium compounds can also cause damage to furnace linings and corrosion of boiler tubes or gas turbine blades. A rapid and sensitive analytical method is need to detect these metals in feedstocks, products, and residual. In this paper such a method using energy dispersive X-ray fluorescence (EDXRF) spectrometry for determination of vanadium, nickel, and iron in petroleum and petroleum residua is described. In order to eliminate matrix effects, samples containing an internal standard (cobalt) were decomposed by heating with concentrated sulfuric acid and the resulting carbonaceous residua were ashed. X-ray fluorescent spectral intensities of V, Ni, Fe, and Co were measured using established instrumental parameters. Since the Fe Kβ and Co Kα lines overlapped, the slope and the intercept of the ratio of Fe Kα to Fe Kβ intensities from the analysis of ash of several iron standards were used for correction of Co spectral intensities. Sample metal concentrations were determined by comparison of spectral ratios to those of ashed calibration standards

  10. Laser-excitation atomic fluorescence spectroscopy in a helium microwave-induced plasma

    Science.gov (United States)

    Schroeder, Timothy S.

    The focus of this dissertation is to report the first documented coupling of helium microwave induced plasmas (MIPs) to laser excitation atomic fluorescence spectroscopy. The ability to effectively produce intense atomic emission from both metal and nonmetal analytes gives helium microwave induced plasmas a greater flexibility than the more commonly utilized argon inductively coupled plasma (ICP). Originally designed as an element selective detector for non-aqueous chromatography applications at low applied powers (plasma has been applied to aqueous sample determinations at higher applied powers (>500 W). The helium MIP has been shown to be a very powerful analytical atomic spectroscopy tool. The development of the pulsed dye laser offered an improved method of excitation in the field of atomic fluorescence. The use of laser excitation for atomic fluorescence was a logical successor to the conventional excitation methods involving hollow cathode lamps and continuum sources. The highly intense, directional, and monochromatic nature of laser radiation results in an increased population of atomic species in excited electronic states where atomic fluorescence can occur. The application of laser excitation atomic fluorescence to the analysis of metals in a helium microwave induced plasma with ultrasonic sample nebulization was the initial focus of this work. Experimental conditions and results are included for the aqueous characterization of manganese, lead, thallium, and iron in the helium MIP- LEAFS system. These results are compared to previous laser excitation atomic fluorescence experimentation. The effect of matrix interferences on the analytical fluorescence signal was also investigated for each element. The advantage of helium MIPs over argon ICPs in the determination of nonmetals in solution indicates that the helium MIP is an excellent candidate for laser excitation atomic fluorescence experiments involving nonmetals such as chlorine, bromine, iodine, and

  11. Investigation of trialkoxysilane hydrolysis kinetics using liquid chromatography with inductively coupled plasma atomic emission spectrometric detection and non-linear regression modeling

    International Nuclear Information System (INIS)

    A novel approach is demonstrated for measuring rates of the consecutive acid-base catalyzed hydrolysis reactions of (3-glycidoxypropyl)trimethoxysilane (GPTMS) and (3-aminopropyl)triethoxysilane (APTES) in dilute aqueous solution using liquid chromatography with inductively coupled plasma atomic emission spectrometric (ICP-AES) detection. The hydrolysis reactions are monitored by sampling kinetic solutions in a timewise manner and performing liquid chromatographic separations of the parent silane and organosilicon hydrolysis products. The column effluent is fed into the ICP through a direct injection nebulizer for online monitoring of silicon atomic emission at 251.611 nm, producing a series of silicon chromatograms for each kinetic run. Reversed phase separations are effected using acetonitrile-water gradients and are complete in 6 min or less. The systematic changes in peak areas provide information from which the rate constants of the consecutive hydrolysis reactions (k1, k2, and k3) are obtained by non-linear regression modeling. Using a quenching scheme, hydrolysis half-lives as brief as 3 min for the parent silane can be monitored. For each compound, a series of rate constants are obtained over a range of pH and buffer concentration, permitting estimation of the catalytic constants kH3O+ and kOH- for the consecutive acid-base catalyzed hydrolysis reactions by multiple regression analysis

  12. Cooperative Fluorescence from a Strongly Driven Dilute Cloud of Atoms

    OpenAIRE

    Ott, Johan Raunkjær; Wubs, Martijn; Lodahl, Peter; Mortensen, N. Asger; Kaiser, R.

    2013-01-01

    We investigate cooperative fluorescence in a dilute cloud of strongly driven two-level emitters. Starting from the Heisenberg equations of motion, we compute the first-order scattering corrections to the saturation of the excited-state population and to the resonance-fluorescence spectrum, which both require going beyond the state-of-the-art linear-optics approach to describe collective phenomena. A dipole blockade is observed due to long-range dipole-dipole coupling that vanishes at stronger...

  13. Quenching-independent fluorescence measurements of atomic hydrogen with photoionization controlled-loss spectroscopy

    International Nuclear Information System (INIS)

    Quenching-independent fluorescence by atomic hydrogen has been measured with photoionization controlled-loss spectroscopy (PICLS) in stoichiometric and fuel-rich premixed H2/O2/N2 flames at a pressure of 20 Torr. These measurements are compared with conventional fluorescence measurements in the same flames. When matched in the postflame zone, the two sets of measurements diverge in the preheat zone between the burner surface and the peak of the fluorescence profiles. This divergence, caused by changes in the local quenching rate coefficient, shows the utility of PICLS for determining the kinetics of atomic hydrogen in the preheat zone

  14. Arsenic speciation analysis by post-separation hydride generation and atomic fluorescence detection

    Czech Academy of Sciences Publication Activity Database

    Marschner, Karel; Musil, Stanislav; Rychlovský, P.; Dědina, Jiří

    2014. s. 133-133. [Rio Symposium on Atomic Spectrometry /13./. 19.10.2014-24.10.2014, Merida, Yucatan] R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : arsenic speciation analysis * hydride generation * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation

  15. Optical resonance shifts in the fluorescence imaging of thermal and cold Rubidium atomic gases

    CERN Document Server

    Jenkins, S D; Javanainen, J; Bourgain, R; Jennewein, S; Sortais, Y R P; Browaeys, A

    2016-01-01

    We show that the resonance shifts in fluorescence of a cold gas of rubidium atoms substantially differ from those of thermal atomic ensembles that obey the standard continuous medium electrodynamics. The analysis is based on large-scale microscopic numerical simulations and experimental measurements of the resonance shifts in a steady-state response in light propagation.

  16. Novel laser atomic fluorescence spectrometer for environmental and biomedical analyses of heavy metals

    Science.gov (United States)

    Dergachev, Alex Y.; Mirov, Sergey B.; Pitt, Robert E.; Parmer, Keith D.

    1997-05-01

    We report on the development of a novel experimental set-up using laser atomic fluorescence for detection and concentration measurements of heavy metal atoms for environmental and biomedical analyses. This spectrometer is based on the application of tunable LiF:F2+** and LiF:F2- color center and alexandrite lasers with nonlinear converters for narrowband excitation of atomic fluorescence and the use of gated multichannel CCD detectors for fluorescence measurements. A standard graphite furnace module was used for sample atomization. The laser sources used provide narrowband selective laser excitation continuously tunable in the 200 - 400 nm range and are therefore suitable for resonant excitation of atomic transitions in practically all known heavy metal atoms. In the first experiments, water samples containing Cu, Pb and Fe impurities were studied and detection levels of less than 1 ppb were observed. Comparison of the results of atomic laser fluorescence analysis and traditional atomic absorption spectrometry showed good qualitative agreement between these two methods. It is projected that full optimization of our experimental set up will allow for improved detection levels of several orders of magnitude. Possible optimization and simplification of the spectrometer are discussed in the context of developing a portable instrument for field use.

  17. Optical Resonance Shifts in the Fluorescence of Thermal and Cold Atomic Gases

    Science.gov (United States)

    Jenkins, S. D.; Ruostekoski, J.; Javanainen, J.; Bourgain, R.; Jennewein, S.; Sortais, Y. R. P.; Browaeys, A.

    2016-05-01

    We show that the resonance shifts in the fluorescence of a cold gas of rubidium atoms substantially differ from those of thermal atomic ensembles that obey the standard continuous medium electrodynamics. The analysis is based on large-scale microscopic numerical simulations and experimental measurements of the resonance shifts in a steady-state response in light propagation.

  18. EPR, FTIR, and FAB mass spectrometric investigation of reaction of H atoms with C 60 in a cyclohexane matrix

    Science.gov (United States)

    Howard, J. A.

    1993-03-01

    Hydrogen atoms have been reacted with C 60 in a cyclohexane matrix at 77 K in a rotating cryostat. Species HC 60, H 2 n + 1 C 60, and H 2 nC 60 have been identified by EPR, FTIR and FAB mass spectrometry. HC 60 has the magnetic parameters aH(1) = 92.9 ± 0.5 MHz and g = 2.00218 ± 0.00004. These values are compared to the deuterium and muonium analogs. Reasons for the isotope effect in the hydrogen and muon hyperfine interactions of HC 60 and MuC 60 are discussed. The narrow line widths of the EPR transitions of H 2 n + 1C 60 may be associated with globe-trotting hydrogen atoms. C 60 acts as a H atom sponge at high atom fluxes and H 2 nC 60s with n as large as 17 have been identified.

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

    Czech Academy of Sciences Publication Activity Database

    Marschner, Karel; Musil, Stanislav; Dědina, Jiří

    2015-01-01

    Roč. 109, JUL (2015), s. 16-23. ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : hydride generation * arsenic * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.176, year: 2014

  20. A double-well atom trap for fluorescence detection at the Heisenberg limit

    CERN Document Server

    Stroescu, Ion; Oberthaler, Markus K

    2014-01-01

    We experimentally demonstrate an atom number detector capable of simultaneous detection of two mesoscopic ensembles with single atom resolution. Such a sensitivity is a prerequisite for going beyond quantum metrology with spin-squeezed states. Our system is based on fluorescence detection of atoms in a novel hybrid trap in which a dipole barrier divides a magneto-optical trap into two separated wells. We introduce a noise model describing the various sources contributing to the measurement error and report a limit of up to 500 atoms for the exact determination of the atom number difference.

  1. Cooperative fluorescence from a strongly driven dilute cloud of atoms

    DEFF Research Database (Denmark)

    Ott, Johan Raunkjær; Wubs, Martijn; Lodahl, Peter;

    2013-01-01

    We investigate cooperative fluorescence in a dilute cloud of strongly driven two-level emitters. Starting from the Heisenberg equations of motion, we compute the first-order scattering corrections to the saturation of the excited-state population and to the resonance-fluorescence spectrum, which...... both require going beyond the state-of-the-art linear-optics approach to describe collective phenomena. A dipole blockade is observed due to long-range dipole-dipole coupling that vanishes at stronger driving fields. Furthermore, we compute the inelastic component of the light scattered by a cloud of...

  2. Graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples stabilized as microemulsion using conventional and permanent modifiers

    International Nuclear Information System (INIS)

    A procedure for the graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples was developed. Sample stabilization was necessary because of evident analyte losses that occurred immediately after sampling. Excellent long-term sample stabilization was observed by mixing different organic solvents with propan-1-ol and 50% vol/vol HNO3 at a 3.3:6.5:1 volume ratio. For Pb, efficient thermal stabilization was obtained using aqueous Pd-Mg modifier as well as for Ir as permanent modifier. The drying temperature and ramp rate influenced the sensitivity obtained for Ni, and had to be carefully optimized. Taking this into account, the same sensitivity was attained in all investigated organic media stabilized as microemulsion. Thus, calibration with microemulsions prepared with a single organic solvent was possible, using aqueous or organic stock solutions. Commercial gasoline and diesel samples were directly analyzed after stabilization as microemulsion and by comparative UOP procedures. n-Hexane microemulsions were used for calibration, and good agreement was obtained between the results using the proposed and comparative procedures. Typical coefficients of variation (n = 6) ranged from 1% to 4%, and from 1% to 3% for Ni and Pb, respectively. Detection limits (k = 3) in the original gasoline or diesel samples, derived from 10 blank measurements, were 4.5 and 3.6 μg l-1 for Ni and Pb, respectively, comfortably below the values found in the analyzed samples

  3. Flame atomic absorption spectrometric determination of trace cadmium in alloys and biological samples after solid-liquid extraction and preconcentration with use of nitroso-S

    International Nuclear Information System (INIS)

    Cadmium is quantitatively retained by 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S) and tetradecyldimethylbenzylammonium chloride (TDBA) on microcrystalline naphthalene in the pH range 5.7-10.5 from a large volumes of aqueous solutions of various samples. After filtration, the solid mass consisting of cadmium complex and naphthalene is dissolved with 5 mL of dimethylformamide and the metal was determined by flame atomic absorption spectrometric. Cadmium complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium-naphthalene adsorbent packed in a column and determined similarly. About 25 ng of cadmium can be concentrated in a column from 500 mL of aqueous sample, where its concentration is as low as 0.05 ng/mL. Eight replicate determinations of 0.1 μg/mL of cadmium in final DMF solution gave a mean absorbance of 0.060 with a relative standard deviation of 1.8 %. The sensitivity for 1 % absorption was 7.3 ng/mL. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of cadmium in various alloys and biological samples. (author)

  4. Flame atomic absorption spectrometric determination of cadmium(II) and lead(II) after their solid phase extraction as dibenzyldithiocarbamate chelates on Dowex Optipore V-493

    International Nuclear Information System (INIS)

    An enrichment procedure for cadmium and lead after their solid phase extraction as dibenzyldithiocarbamate chelates on Dowex Optipore V-493 has been established prior to their flame atomic absorption spectrometric determinations. The analytical parameters including pH, amounts of dibenzyldithiocarbamate, sample volume, etc., were investigated. The effects of alkaline and earth alkaline ions and some metal ions on the retentions of analytes on Dowex Optipore V-493 resin were examined. Under the optimized conditions, the detection limits (3s, n = 21) for cadmium and lead were 0.43 μg L-1 and 0.65 μg L-1, respectively. The relative standard deviation (R.S.D.), and the recoveries of standard addition for this method were lower than 5% (n = 11) and 95-102%, respectively. Three standard reference samples (LGC 6010 Hard drinking water, NIST SRM 2711 Montana soil and GBW 07605 Tea) were introduced for accuracy and precision of analytical data. The proposed solid phase extraction system was successfully applied to the analysis of environmental samples

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

    International Nuclear Information System (INIS)

    Nuclear Fuel Complex (NFC) receives Sodium Di-Uranate (SDU) from Uranium Corporation of India Limited (UCIL) for producing sinterable UO2 pellets for manufacturing fuel sub assemblies. Several impurities present in ore find their way into SDU during its conversion. Stringent specification have been laid down by the reactor designs for achieving the optimum performance of the fuel and several impurity element like Al, Ca, Fe, Mg, Mn, Na among others affects severely performance of UO2 fuel. Most of the impurity including the above mentioned elements are generally analysed by ICP-OES method. However, determination of Al, Ca, Fe, Mg, Mn and Na by ICP-OES requires lot of dilution as they are present at high levels in SDU. Apart from introducing dilution error, dilution process is very tedious and time consuming work and not a preferred choice in an industrial lab like control lab where large analytical load exists and time bound analysis is a requirement. To avoid these difficulties a simple and reliable Flame Atomic absorption spectrometric technique has been developed for regular analysis. Present method involves dissolution of SDU sample in Conc. HNO3 and after the complete dissolution the sample solution has been evaporated to near dryness on a hot plate. Subsequently sample solution has been brought into 4N HNO3 medium

  6. Graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples stabilized as microemulsion using conventional and permanent modifiers

    Science.gov (United States)

    Reyes, Mariela N. Matos; Campos, Reinaldo C.

    2005-06-01

    A procedure for the graphite furnace atomic absorption spectrometric determination of Ni and Pb in diesel and gasoline samples was developed. Sample stabilization was necessary because of evident analyte losses that occurred immediately after sampling. Excellent long-term sample stabilization was observed by mixing different organic solvents with propan-1-ol and 50% vol/vol HNO 3 at a 3.3:6.5:1 volume ratio. For Pb, efficient thermal stabilization was obtained using aqueous Pd-Mg modifier as well as for Ir as permanent modifier. The drying temperature and ramp rate influenced the sensitivity obtained for Ni, and had to be carefully optimized. Taking this into account, the same sensitivity was attained in all investigated organic media stabilized as microemulsion. Thus, calibration with microemulsions prepared with a single organic solvent was possible, using aqueous or organic stock solutions. Commercial gasoline and diesel samples were directly analyzed after stabilization as microemulsion and by comparative UOP procedures. n-Hexane microemulsions were used for calibration, and good agreement was obtained between the results using the proposed and comparative procedures. Typical coefficients of variation ( n = 6) ranged from 1% to 4%, and from 1% to 3% for Ni and Pb, respectively. Detection limits ( k = 3) in the original gasoline or diesel samples, derived from 10 blank measurements, were 4.5 and 3.6 μg l - 1 for Ni and Pb, respectively, comfortably below the values found in the analyzed samples.

  7. Mass spectrometric determination of atomization energies of inorganic molecules and their correlation by empirical models of bonding

    International Nuclear Information System (INIS)

    The application of the Knudsen effusion method combined with mass spectrometry for the measurement of atomization energies of inorganic molecules is described. Recent results with emphasis on molecular metals, intermetallic molecules and metal carbides are presented. The use and limitations of various empirica models of bonding are illustrated by comparing experimental values with those calculated by the various models

  8. Electrothermal atomic absorption spectrometric determination of lithium, sodium, potassium and copper in uranium without preliminary chemical separation

    International Nuclear Information System (INIS)

    Graphite furnace atomization is used for the direct determination of Li (0.25-4 ppm), Na (8-70 ppm), K (20-300 ppm) and Cu (0.5-25 ppm) in uranium dissolved in nitric acid, with relative standard deviations of 4-9%. Only iron seriously depresses the signals from the alkali metals. (Auth.)

  9. Ultimate Statistical Physics: fluorescence of a single atom

    CERN Document Server

    Pomeau, Yves; Ginibre, Jean

    2016-01-01

    We discuss the statistics of emission of photons by a single atom or ion illuminated by a laser beam at the frequency of quasi-resonance between two energy levels, a situation that corresponds to real experiments. We extend this to the case of two laser beams resonant with the energy differences between two excited levels and the ground state (three level atom in V-configuration). We use a novel approach of this type of problem by considering Kolmogorov equation for the probability distribution of the atomic state which takes into account first the deterministic evolution of this state under the effect of the incoming laser beam and the random emission of photons during the spontaneous decay of the excited state(s) to the ground state. This approach yields solvable equations in the two level atom case. For the three level atom case we set the problem and define clearly its frame. The results obtained are valid both in the opposite limits of rare and of frequent spontaneous decay, compared to the period of the...

  10. 微波消解-原子荧光光谱法测定宫瘤消片中的砷、镉%Measuring of arsenic and lead in the Gongliuxiao tablets by microwave digestion and atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    运行; 安迎雪; 尤海丹

    2012-01-01

    Objective: To develop a atomic fluorescence spectrometric method for the determination of heavy metals ( As,Cd) in Gongliuxiao. Method:Sample were digested with microwave system,and the As,Gd were directly analyzed by atomic fluorescence spectrometric. Result:For the analyzed heavy metals,the correlative coefficient of the calibration curves was over0. 9992,the recovery was 91. 5% -97. 8% ,RSD was less 5%. Conclusion:The method is convenient and highly sensitive. The method had been applied to the determination of trace heavy metals in traditional Chinese medicine with satisfactory results.%目的:测定宫瘤消片中的砷、镉.方法:采用微波消解的制样方法,利用原子荧光光谱法测定了宫瘤消片中镉、砷微量元素的含量.结果:测得2种元素,标准曲线的r>0.9992,回收率为91.5%~97.8%,RSD <5%.结论:本法快速、准确且灵敏度高,为宫瘤消片中重金属含量测定提供了较好的方法,结果满意.

  11. Experimental and theoretical comparison of the precision of flame atomic absorption, fluorescence, and emission measurements

    International Nuclear Information System (INIS)

    Theoretical equations and experimental evaluation procedures for the determination of the precision of flame atomic absorption, emission, and fluorescence measurements are presented. These procedures and noise power spectra are used to evaluate the precision and noise characteristics of atomic copper measurements with all three techniques under the same experimental conditions in a H2-air flame. At the detection limit, emission and fluorescence measurements are limited by background emission shot and flicker noise whereas absorption measurements are limited by flame transmission lamp flicker noise. Analyte flicker noise limits precision at higher analyte concentrations for all three techniques. Fluctutations in self-absorption and the inner filter effect are shown to contribute to the noise in atomic emission and fluorescence measurements

  12. In-trap fluorescence detection of atoms in a microscopic dipole trap

    CERN Document Server

    Hilliard, A J; Sompet, P; Carpentier, A V; Andersen, M F

    2015-01-01

    We investigate fluorescence detection using a standing wave of blue-detuned light of one or more atoms held in a deep, microscopic dipole trap. The blue-detuned standing wave realizes a Sisyphus laser cooling mechanism so that an atom can scatter many photons while remaining trapped. When imaging more than one atom, the blue detuning limits loss due to inelastic light-assisted collisions. Using this standing wave probe beam, we demonstrate that we can count from one to the order of 100 atoms in the microtrap with sub-poissonian precision.

  13. Polymerized LB films imaged with a combined atomic force microscope-fluorescence microscope

    OpenAIRE

    Putman, Constant A.J.; Hansma, Helen G.; Gaub, Hermann E.; Hansma, Paul K.

    1992-01-01

    The first results obtained with a new stand-alone atomic force microscope (AFM) integrated with a standard Zeiss optical fluorescence microscope are presented. The optical microscope allows location and selection of objects to be imaged with the high-resolution AFM. Furthermore, the combined microscope enables a direct comparison between features observed in the fluorescence microscope and those observed in the images obtained with the AFM, in air or under liquid. The cracks in polymerized La...

  14. Instantaneous temperature imaging of diffusion flames using two-line atomic fluorescence.

    Science.gov (United States)

    Medwell, Paul R; Chan, Qing N; Kalt, Peter A M; Alwahabi, Zeyad T; Dally, Bassam B; Nathan, Graham J

    2010-02-01

    This work investigates the first demonstration of nonlinear regime two-line atomic fluorescence (NTLAF) thermometry in laminar non-premixed flames. The results show the expediency of the technique in the study of the reaction zone and reveals interesting findings about the indium atomization process. Indium fluorescence is observed to be strongest at the flame-front, where the temperature exceeds 1000 K. The uncertainty in the deduced temperature measurement is approximately 6%. The temperature profile across the reaction zone shows good agreement with laminar flame calculations. The advantages and inherent limitations of the technique are discussed. PMID:20149278

  15. The stationary resonance fluorescence of a two-level atom in a cat-state field

    Science.gov (United States)

    Tomilin, V. A.; Il'ichov, L. V.

    2016-09-01

    We investigate the resonance fluorescence of a two-level atom placed in non-classical field which is a superposition of Glauber coherent states. The source of this superposition known under the common name of 'Schrödinger cat'-states is explicitly incorporated into the model. This let us to explore the stationary regime. In the strong (multiphoton) field limit the steady-state of the atom+photons system is found. We evaluated the spectrum of the resonance fluorescence. It appears to be one-component in contrast to the case with the classical external field.

  16. Nitrogen atom detection in low-pressure flames by two-photon laser-excited fluorescence

    OpenAIRE

    Bittner, Jürgen; Lawitzki, Annette; Meier, Ulrich; Kohse-Höinghaus, Katharina

    1991-01-01

    Nitrogen atoms have been detected in stoichiometric flat premixed H2/O2/N2 flames at 33 and 96 mbar doped with small amounts of NH3, HCN, and (CN)2 using two-photon laser excitation at 211 nm and fluorescence detection around 870 nm. The shape of the fluorescence intensity profiles versus height above the burner surface is markedly different for the different additives. Using measured quenching rate coefficients and calibrating with the aid of known N-atom concentrations in a discharge flow r...

  17. (2+1) laser-induced fluorescence of spin-polarized hydrogen atoms.

    Science.gov (United States)

    Bougas, Lykourgos; Sofikitis, Dimitris; Everest, Michael A; Alexander, Andrew J; Rakitzis, T Peter

    2010-11-01

    We report the measurement of the spin polarization of hydrogen (SPH) atoms by (2+1) laser-induced fluorescence, produced via the photodissociation of thermal HBr molecules with circularly polarized 193 nm light. This scheme, which involves two-photon laser excitation at 205 nm and fluorescence at 656 nm, offers an experimentally simpler polarization-detection method than the previously reported vacuum ultraviolet detection scheme, allowing the detection of SPH atoms to be performed more straightforwardly, from the photodissociation of a wide range of molecules and from a variety of collision experiments. PMID:21054033

  18. Arsenic speciation analysis by hydride generation – cryotrapping – atomic fluorescence spectrometry with flame-in-gas-shield atomizer

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Milan; Musil, Stanislav; Matoušek, Tomáš; Rychlovský, P.; Dědina, Jiří

    Prague: Charles University in Prague, Faculty of Science, 2010 - (Nesměrák, K.), s. 19-22. (1). ISBN 978-80-7444-005-2. [International Students Conference "Modern Analytical Chemistry" /6./. Praha (CZ), 23.09.2010-24.09.2010] R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : arsenic speciation * cryogenic trapping * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation

  19. Arsenic speciation analysis based on selective hydride generation and atomic fluorescence detection

    Czech Academy of Sciences Publication Activity Database

    Marschner, Karel; Rychlovský, P.; Musil, Stanislav; Dědina, Jiří

    Praha, 2014. s. 107-107. ISBN 978-80-905704-1-2. [European Symposium on Atomic Spectrometry ESAS 2014 & Czech-Slovak Spectroscopic Conference /15./. 16.03.2014-21.03.2014, Praha] R&D Projects: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : arsenic speciation analysis * hydride generation * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation

  20. Development of a cloud point extraction and preconcentration method for Cd and Ni prior to flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Manzoori, Jamshid L. [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)]. E-mail: manzoori@tabrizu.ac.ir; Karim-Nezhad, Ghasem [Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2004-09-13

    In this work a new cloud point extraction (CPE) methodology was developed for the separation and preconcentration of cadmium and nickel. The analyte in the initial aqueous solution was complexed with dithizone and Triton X-114 was added as surfactant. After phase separation, based on the cloud point of the mixture, and dilution of the surfactant-rich phase with tetrahydrofuran (THF), the enriched analytes were determined by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions and preconcentration of only 10 ml of sample in the presence of 0.05% Triton X-114, the enhancement factors of 52 and 39 and the detection limits of 0.31 {mu}g l{sup -1} and 1.2 {mu}g l{sup -1} were obtained for cadmium and nickel respectively. The proposed method was applied satisfactorily to the determination of cadmium and nickel in water samples.

  1. Three-phase plasma arc atomic-emission spectrometric analysis of environmental samples using an ultrasonic nebulizer

    Energy Technology Data Exchange (ETDEWEB)

    Ghatass, Zekry F. [Institute of Graduate Studies and Research, Alexandria University, 163 El-Horreya Avenue, P.O. Box 832, Chatby 21526, Alexandria (Egypt); Roston, Gamal D. [Department of Physics, Faculty of Science, Alexandria University, Alexandria (Egypt); Mohamed, Moustafa M. [Medical Research Institute, Alexandria University, Alexandria (Egypt)

    2003-06-01

    Combination of an ultrasonic nebulizer and plasma excitation sources for spectrochemical analysis offers desirable features of low detection limits, high sample throughput, wide dynamic range of operation, acceptable precision and accuracy, and simultaneous quantitative analytical capabilities. Moreover, the ultrasonic nebulizer does not require sample preconcentration. Recently we have developed a three-phase plasma arc (TPPA) for atomic emission spectrochemical analysis. In the present work, to increase the analytical utility of the three-phase plasma system, an ultrasonic nebulizer was used for sample introduction. The effects of the argon gas flow rate, current, excitation temperature have been studied. The analytical calibration curves are obtained for Ca, Cr, Fe, Mg and Mn, and detection limits have been calculated. The present technique is used to determine the concentration of the elements Ca, Cr, Fe, Mg and Mn in airborne samples. (orig.)

  2. Determination of Cr(VI) in welding fumes by anion-exchange fast protein liquid chromatography with electrothermal atomic absorption spectrometric detection.

    Science.gov (United States)

    Milacic, Radmila; Scancar, Janez; Tusek, Janez

    2002-02-01

    The applicability of an anion-exchange fast protein liquid chromatographic-electrothermal atomic absorption spectrometric procedure (FPLC-ETAAS) was investigated for the determination of Cr(VI) in welding fumes after alkaline extraction of aerosols loaded on filters. Gas tungsten arc welding (GTAW) of stainless steel was applied. Samples of welding fumes were collected during regular welding on polycarbonate membrane filters of 8 microm and 0.4 microm pore size (inhalable and respirable aerosols). Alkaline extraction (2% NaOH-3% Na2CO3) of filters in a heated ultrasonic bath was applied to leach Cr from the airborne particulate matter. 0.5 cm3 of sample extract was then injected onto an anion-exchange FPLC column. Tris-HCl buffer (0.005 mol dm(-3), pH 8.0) and the same buffer with NaCl (0.5 mol dm(-3)) were employed in gradient elution (15 min, flow rate 1 cm3 min(-1)). The separated Cr species were determined "off line" by ETAAS in 0.5 cm3 fractions. Cr(VI) was reproducibly and quantitatively eluted from 12.0 to 13.0 min with a maximum peak at 12.5 min. Good repeatability of measurement (+/-3.0%) of alkaline extracts was obtained for Cr(VI). The LOD (3s) was found to be 0.035 microg m(-3) Cr(VI), when 2 m3 of aerosols were collected on the filter. Validation of the procedure was performed by spiking alkaline extracts and by the analysis of standard reference material CRM 545, Cr(VI) in welding dust loaded on a filter. The technique was successfully applied for the determination of Cr(VI) in welding fumes. PMID:11939630

  3. Polymerized LB films imaged with a combined atomic force microscope-fluorescence microscope

    NARCIS (Netherlands)

    Putman, Constant A.J.; Hansma, Helen G.; Gaub, Hermann E.; Hansma, Paul K.

    1992-01-01

    The first results obtained with a new stand-alone atomic force microscope (AFM) integrated with a standard Zeiss optical fluorescence microscope are presented. The optical microscope allows location and selection of objects to be imaged with the high-resolution AFM. Furthermore, the combined microsc

  4. Multi-element coprecipitation for separation and enrichment of heavy metal ions for their flame atomic absorption spectrometric determinations

    International Nuclear Information System (INIS)

    A preconcentration-separation technique for lead(II), cadmium(II), chromium(III), nickel(II) and manganese(II) ions has been established. The procedure is based on coprecipitation of these ions by the aid of Cu(II)-dibenzyldithiocarbamate precipitate. The precipitate was dissolved in 0.5 mL of concentrated HNO3, and made up to 5 mL with distilled water. The heavy metals were determined by flame atomic absorption spectrometer. The effects of analytical parameters like pH, amounts of reagents, sample volume, etc. on the recoveries of heavy metals were investigated. The influences of matrix ions were also examined. The detection limits for the heavy metals based on 3 sigma (N = 21) were found in the range of 0.34-0.87 μg L-1. In order to validate the proposed method, two certified reference materials of NIST SRM 2711 Montana soil and NIST SRM 1515 Apple leaves were analyzed with satisfactory results. The proposed method was applied for the determination of lead, cadmium, chromium, nickel and manganese in environmental samples

  5. Standard test method for graphite furnace atomic absorption spectrometric determination of lead and cadmium extracted from ceramic foodware

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 g/mL and cadmium concentrations greater than 0.0005 to 0.002 g/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination cont...

  6. Cloud Point Extraction and Flame Atomic Absorption Spectrometric Determination of Lead, Cadmium and Palladium in Some Food and Biological Samples

    Directory of Open Access Journals (Sweden)

    M. Soylak

    2011-12-01

    Full Text Available The proposed method is based on the complexation of the Pb2+, Cd2+ and Pd2+ ions with 3-(1-(1-H-Indol-3-Yl-3-phenylallyl-1H-indole (IPAI at pH 8.0 in the presence of Triton X-114. The phase separation occured when micellar solution was heated at 55 ◦C. The surfactant-rich phase, diluted to 0.5 mL via 1.0 mol L−1 nitric acid in methanol was directly introduced into the nebulizer of the flame atomic absorption spectrometry (FAAS. Influence of variables such as pH, amount of ligand and Triton X-114, heating time and temperature were evaluated and optimized. The optimized enhancement factors for Pb2+, Cd2+ and Pd2+ ions were 22, 33 and 23, respectively and the detection limit (DLs was between of 1.6–2.6 µgL−1. The relative standard deviation (RSD of each ion was found to be less than 4.6% at 100 µgL−1. In addition, the calibration graphs were linear in the range of 0.01-0.22 μg mL−1 for Cd2+ ion, 0.018-0.26 μg mL−1 for Pb2+ ion and 0.02-0.27 μg mL−1 for Pd2+ ion with the correlation coefficients in the range of 0.995–0.999.

  7. Far-field resonance fluorescence from a dipole-interacting laser-driven cold atomic gas

    CERN Document Server

    Jones, Ryan; Olmos, Beatriz

    2016-01-01

    We analyze the temporal response of the fluorescence light that is emitted from a dense gas of cold atoms driven by a laser. When the average interatomic distance is smaller than the wavelength of the photons scattered by the atoms, the system exhibits strong dipolar interactions and collective dissipation. We solve the exact dynamics of small systems with different geometries and show how these collective features are manifest in the scattered light properties such as the photon emission rate, the power spectrum and the second-order correlation function. By calculating these quantities beyond the weak driving limit, we make progress in understanding the signatures of collective behavior in these many-body systems. Furthermore, we clarify the role of disorder on the resonance fluorescence, of direct relevance for recent experimental efforts that aim at the exploration of many-body effects in dipole-dipole interacting gases of atoms.

  8. Determination of Ca, Mg, Na, Cd, Cu, Fe, K, Li and Zn in acid mine and reference water samples by inductively coupled plasma atomic fluorescence spectrometry

    Science.gov (United States)

    Sanzolone, R.F.; Meier, A.L.

    1986-01-01

    An inductively coupled plasma atomic fluorescence spectrometric (ICP-AFS) method was used for the determination of nine elements in natural water. Reference and acid mine water samples were analysed by this method to demonstrate its usefulness for hydrogeochemical exploration. The elements were determined in two groups based on the compatibility of operating conditions and consideration of element abundance levels in natural water. Ca, Mg and Na were determined as a group using one set of instrumental conditions and a 1 + 99 dilution of the sample, and Cd, Cu, Fe, K, Li and Zn were determined using another set of conditions and the undiluted sample. The detection limits for the elements are as follows: Ca, 1.4; Mg, 1.7; Na, 2.0; Cd, 1.8; Cu, 6.2; Fe, 15.8; K, 3.5; Li, 0.3; and Zn, 1.2 ng m1-1. Each element has a linear range spanning about four orders of magnitude. The method has good precision and accuracy, as shown by statistics on replicate analyses and by the agreement between values obtained and those recommended for the reference water samples, and also those obtained by atomic absorption spectrometry for the acid mine water samples.

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

    International Nuclear Information System (INIS)

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

  10. 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

  11. On-line sample processing involving microextraction techniques as a front-end to atomic spectrometric detection for trace metal assays: A review

    Energy Technology Data Exchange (ETDEWEB)

    Miró, Manuel, E-mail: manuel.miro@uib.es [FI-TRACE Group, Department of Chemistry, Faculty of Sciences, University of the Balearic Islands, E-07122 Palma de Mallorca, Illes Balears (Spain); Hansen, Elo Harald [Granåsen 93, DK-2800 Kgs. Lyngby (Denmark)

    2013-06-11

    Graphical abstract: -- Highlights: •Role of flow injection in automation of microextraction techniques for metal assays. •On-line coupling of liquid phase microextraction (LPME) to atomic spectrometry. •Critical evaluation of on-line single drop and dispersive LPME. •On-line coupling of micro-solid phase extraction (μSPE) to atomic spectrometry. •Critical appraisal of magnetic/carbon nanoparticles and biomass for on-line μSPE. -- Abstract: Within the last decade, liquid-phase microextraction (LPME) and micro-solid phase extraction (μSPE) approaches have emerged as substitutes for conventional sample processing procedures for trace metal assays within the framework of green chemistry. This review surveys the progress of the state of the art in simplification and automation of microextraction approaches by harnessing to the various generations of flow injection (FI) as a front end to atomic absorption spectrometry (AAS), atomic fluorescence spectrometry (AFS) or inductively coupled plasma atomic emission spectrometry or mass spectrometry (ICP-AES/MS). It highlights the evolution of flow injection analysis and related techniques as vehicles for appropriate sample presentation to the detector and expedient on-line matrix separation and pre-concentration of trace levels of metals in troublesome matrices. Rather than being comprehensive this review is aimed at outlining the pros and cons via representative examples of recent attempts in automating green sample preparation procedures in an FI or sequential injection (SI) mode capitalizing on single-drop microextraction, dispersive liquid-phase microextraction and advanced sorptive materials including carbon and metal oxide nanoparticles, ion imprinted polymers, superparamagnetic nanomaterials and biological/biomass sorbents. Current challenges in the field are identified and the synergetic combination of flow analysis, nanotechnology and metal-tagged biomolecule detection is envisaged.

  12. Fluorescence studies on 20Na and excited neon atoms in proton-induced plasmas

    International Nuclear Information System (INIS)

    In this thesis, an experimental study on the application of the optical fluorescence technique for the detection of excited and ground-state atoms in a neon plasma produced by 20-MeV protons is presented. By making use of a continuous-wave dye laser tuned to the D2-line of sodium, the 20Na atoms, produced via the reaction 20Ne(p,h)20Na, were excited and the intensity of the fluorescence light measured for several positions in the reaction vessel. From the time dependence of the fluorescence signal after a period of production by the proton beam, the diffusion of the 20Na atoms through the reaction vessel could be studied. Using single-mode operation of the dye laser the absorption line shape of the 23Na D-lines and the isotope shift of the 20Na D-lines with respect to the 23Na D-lines were determined. The proton beam was used as a well-defined excitation source to study the kinetic behaviour of neon atoms in the 1S2, 1S4 and 1S5 states. To learn the effect of plasma conditions on the results of the experiments, the electron density and the electron temperature in the plasma were measured

  13. Fluorescence spectra of atomic ensembles in a magneto-optical trap as an optical lattice

    CERN Document Server

    Yoon, Seokchan; Kang, Sungsam; Kim, Wook-Rae; Kim, Jung-Ryul; An, Kyungwon

    2015-01-01

    We present a study on characteristics of a magneto-optical trap (MOT) as an optical lattice. Fluorescence spectra of atoms trapped in a MOT with a passively phase-stabilized beam configuration have been measured by means of the photon-counting heterodyne spectroscopy. We observe a narrow Rayleigh peak and well-resolved Raman sidebands in the fluorescence spectra which clearly show that the MOT itself behaves as a three-dimensional optical lattice. Optical-lattice-like properties of the phase-stabilized MOT such as vibrational frequencies and lineshapes of Rayleigh peak and Raman sidebands are investigated systematically for various trap conditions.

  14. Energy dissipation in matrix-isolated silver atoms: A time-resolved fluorescence study

    Science.gov (United States)

    Wiggenhauser, H.; Schroeder, W.; Kolb, D. M.

    1988-03-01

    The fluorescence from optically excited Ag atoms in Ar, Kr, and Xe matrices has been investigated in a time-resolved synchrotron-radiation study. A detailed energy dissipation model could be established from a systematic analysis of rise and decay times of all the observed fluorescence bands after pulsed excitation into the Ag (4d105p)2P1/2,3/2 levels, and by setting time windows between the excitation pulses in emission and emission-yield spectroscopy. Although the overall wavelength dependence of the decay time follows the λ3 law, the decay time is independent of λ within a given emission band. Finally, the role of energy transfer between Ag atoms and dimers for the evaluation of decay times is briefly addressed.

  15. Arsenic speciation analysis by HPLC postcolumn hydride generation and detection by atomic fluorescence spectrometry

    Czech Academy of Sciences Publication Activity Database

    Marschner, Karel; Musil, Stanislav; Rychlovský, P.; Dědina, Jiří

    Prague: Charles University in Prague, Faculty of Science, 2014 - (Nesměrák, K.), s. 74-77 ISBN 978-80-7444-030-4. [International Students Conference "Modern Analytical Chemistry" /10./. Prague (CZ), 22.09.2014-23.09.2014] R&D Projects: GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : arsenic speciation analysis * hydride generation * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation http://www.natur.cuni.cz/isc-mac/

  16. Elasticity Maps of Living Neurons Measured by Combined Fluorescence and Atomic Force Microscopy

    OpenAIRE

    Spedden, Elise; White, James D.; Naumova, Elena N.; Kaplan, David L.; Staii, Cristian

    2013-01-01

    Detailed knowledge of mechanical parameters such as cell elasticity, stiffness of the growth substrate, or traction stresses generated during axonal extensions is essential for understanding the mechanisms that control neuronal growth. Here, we combine atomic force microscopy-based force spectroscopy with fluorescence microscopy to produce systematic, high-resolution elasticity maps for three different types of live neuronal cells: cortical (embryonic rat), embryonic chick dorsal root ganglio...

  17. New energy levels of atomic niobium by laser induced fluorescence spectroscopy in the near infrared

    International Nuclear Information System (INIS)

    Laser-induced fluorescence spectroscopy was applied in order to find new energy levels of the niobium atom. A continuous wave tuneable titanium–sapphire laser in the wavelength range from 750 to 865 nm and a hollow-cathode lamp were used. We discovered four energy levels of even parity, three lying levels below 19 000 cm−1 and one at much higher energy. Additionally hyperfine structure data of six levels of odd parity were determined. (paper)

  18. Elemental analysis of hair samples using energy dispersive X-ray fluorescence and atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Elemental analysis of hair samples was performed using energy dispersive X-ray fluorescence. The ion exchange preconcentration technique was employed. The capacity of the exchanger used-cellulose hyphan at different pH was investigated to determine the optimum pH for the resin. The capacity of the resin to take up elements of interest from mixed solutions was also analysed using atomic absorption spectroscopy. (author)

  19. Study of a Model Humic Acid-type Polymer by Fluorescence Spectroscopy and Atomic Force Microscopy

    OpenAIRE

    Marcos Antonio Piza; Nelson Consolin-Filho; Sérgio da Costa Saab; Daiana Kotra Deda; Fábio de Lima Leite; Marcilene Ferrari Barriquello; Ladislau Martin-Neto

    2012-01-01

    A model HA-type polymer of para-benzoquinone synthetic humic acid (SHA) and its complexes with copper, iron and manganese metal ions were studied using atomic force microscopy (AFM). Natural humic acids (HA) and synthetic humic acids (SHA) were examined by fluorescence spectroscopy, which indicated similarity of SHA and HA spectra. The AFM images of SHA and its complexes revealed variable morphologies, such as small spheres, aggregates and a sponge-like structure. The SHA complexes displayed ...

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

    International Nuclear Information System (INIS)

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

  1. Plasma jet desorption atomization-atomic fluorescence spectrometry and its application to mercury speciation by coupling with thin layer chromatography.

    Science.gov (United States)

    Liu, Zhifu; Zhu, Zhenli; Zheng, Hongtao; Hu, Shenghong

    2012-12-01

    A novel plasma jet desorption atomization (PJDA) source was developed for atomic fluorescence spectrometry (AFS) and coupled on line with thin layer chromatography (TLC) for mercury speciation. An argon dielectric barrier discharge plasma jet, which is generated inside a 300 μm quartz capillary, interacts directly with the sample being analyzed and is found to desorb and atomize surface mercury species rapidly. The effectiveness of this PJDA surface sampling technique was demonstrated by measuring AFS signals of inorganic Hg(2+), methylmercury (MeHg), and phenylmercury (PhHg) deposited directly on TLC plate. The detection limits of the proposed PJDA-AFS method for inorganic Hg(2+), MeHg, and PhHg were 0.51, 0.29, and 0.34 pg, respectively, and repeatability was 4.7%, 2.2%, and 4.3% for 10 pg Hg(2+), MeHg, and PhHg. The proposed PJDA-AFS was also successfully coupled to TLC for mercury speciation. Under optimized conditions, the measurements of mercury dithizonate (Hg-D), methylmercury dithizonate (MeHg-D), and phenylmercury dithizonate (PhHg-D) could be achieved within 3 min with detection limits as low as 8.7 pg. The combination of TLC with PJDA-AFS provides a simple, cost-effective, relatively high-throughput way for mercury speciation. PMID:23153091

  2. A semiclassical study of laser-induced atomic fluorescence from Na2, K2 and NaK

    Science.gov (United States)

    Yuan, J.-M.; Bhattacharyya, D. K.; George, T. F.

    1982-01-01

    A semiclassical treatment of laser-induced atomic fluorescence for the alkali-dimer systems Na2, K2 and NaK is presented. The variation of the fluorescence intensity with the frequency of the exciting laser photon is studied and a comparison of theoretical results with a set of experimental data is presented.

  3. Photoluminescence Enhancement in Nanotextured Fluorescent SiC Passivated by Atomic Layer Deposited Al2O3 Films

    DEFF Research Database (Denmark)

    Lu, Weifang; Ou, Yiyu; Jokubavicius, Valdas;

    2016-01-01

    The influence of thickness of atomic layer deposited Al2O3 films on nano-textured fluorescent 6H-SiC passivation is investigated. The passivation effect on the light emission has been characterized by photoluminescence and time-resolved photoluminescence at room temperature. The results show that...... passivation in fluorescent SiC based white LEDs applications....

  4. Commercial Applications of X Ray Spectrometric Techniques

    International Nuclear Information System (INIS)

    In the 21st century, the X-ray fluorescence (XRF) technique is widely used in process control, industrial applications and for routine elemental analysis. The technique has a multielement capability capable of detecting elements with Z ≥ 10, with a few instruments capable of detecting also elements with Z ≥ 5. It is characterized by a non-destructive analysis process and relatively good detection limits, typically one part per million, for a wide range of elements. The first commercial XRF instruments were introduced to the market about 50 years ago. They were the wavelength dispersive X ray fluorescence (WDXRF) spectrometers utilizing Bragg’s law and reflection on crystal lattices for sequential elemental analysis of sample composition. The advances made in radiation detector technology, especially the introduction of semiconductor detectors, improvements in signal processing electronics, availability and exponential growth of personal computer market led to invention of energy dispersive X ray fluorescence (EDXRF) technique. The EDXRF is more cost effective as compared to WDXRF. It also allows for designing compact instruments. Such instruments can be easily tailored to the needs of different customers, integrated with industrial installations, and also miniaturized for the purpose of in-situ applications. The versatility of the technique has been confirmed in a spectacular way by using the XRF and X-ray spectrometric techniques, among few others, during the NASA and ESA missions in search for the evidence of life and presence of water on the surface of Mars. The XRF technique has achieved its strong position within the atomic spectroscopy group of analytical techniques not only due to its versatility but also due to relatively low running costs, as compared to the commonly used methods, e.g., atomic absorption spectrometry (AAS) or inductively coupled plasma atomic emission/mass spectrometry (ICP-AES/MS). Presently, the XRF technique together with X ray

  5. PEGylated Fluorescent Nanoparticles from One-Pot Atom Transfer Radical Polymerization and “Click Chemistry”

    Directory of Open Access Journals (Sweden)

    Li Qun Xu

    2015-10-01

    Full Text Available The preparation of PEGylated fluorescent nanoparticles (NPs based on atom transfer radical polymerization (ATRP and “click chemistry” in one-pot synthesis is presented. First, poly(p-chloromethyl styrene-alt-N-propargylmaleimide (P(CMS-alt-NPM copolymer was prepared via reversible addition-fragmentation chain transfer (RAFT polymerization. Subsequently, the azido-containing fluorene-based polymer, poly[(9,9-dihexylfluorene-alt-(9,9-bis-(6-azidohexylfluorene] (PFC6N3, was synthesized via Suzuki coupling polymerization, followed by azidation. Finally, the PEGylated fluorescent NPs were prepared via simultaneous intermolecular “click” cross-linking between P(CMS-alt-NPM and PFC6N3 and the ATRP of poly(ethylene glycol methyl ether methacrylate (PEGMMA using P(CMS-alt-NPM as the macroinitiator. The low cytotoxicity of the PEGylated fluorescent NPs was revealed by incubation with KB cells, a cell line derived from carcinoma of the nasopharynx, in an in vitro experiment. The biocompatible PEGylated fluorescent NPs were further used as a labeling agent for KB cells.

  6. Use of laser-excited atomic fluorescence spectroscopy for characterization of an argon inductively coupled plasma

    International Nuclear Information System (INIS)

    Laser-excited atomic fluorescence spectroscopy (LEAFS) is investigated and employed as a diagnostic technique for study of the argon inductively coupled plasma (ICP). Computer simulations are used to describe the behavior of nonsteady-state laser excited fluorescence (LEF) for multi-level atomic systems under conditions expected to be encountered in the ICP and an atmospheric pressure flame. These simulations are then compared to experimental data collected under similar conditions in the ICP and a flame. These studies show that LEAFS should be a useful tool for characterization of an ICP, with certain limitations. Relatively small changes in saturated LEF signals under changing quenching and mixing conditions are both predicted theoretically and observed experimentally for several atomic systems. This independence from quenching and mixing effects allows one to relate saturated LEF signals directly to relative number densities of species when spatially scanning over an inhomogeneous medium, such as an ICP discharge, where significant changes in quenching can be encountered in a single scan. SSI values are also found to be useful as indicators of relative collisional quenching rates and relative degree of LTE establishment in the ICP, as well as ease of saturation for a given transition

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

    Energy Technology Data Exchange (ETDEWEB)

    Arp, U. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Electron and Optical Physics Div.; LeBrun, T.; Southworth, S.H.; Jung, M. [Argonne National Lab., IL (United States). Physics Div.; MacDonald, M.A. [E.P.S.R.C. Daresbury Lab., Warrington (United Kingdom)

    1996-12-01

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

  8. Mass spectrometric immunoassay

    Science.gov (United States)

    Nelson, Randall W; Williams, Peter; Krone, Jennifer Reeve

    2007-12-04

    Rapid mass spectrometric immunoassay methods for detecting and/or quantifying antibody and antigen analytes utilizing affinity capture to isolate the analytes and internal reference species (for quantification) followed by mass spectrometric analysis of the isolated analyte/internal reference species. Quantification is obtained by normalizing and calibrating obtained mass spectrum against the mass spectrum obtained for an antibody/antigen of known concentration.

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

    International Nuclear Information System (INIS)

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

  10. Two-photon absorption laser-induced fluorescence measurement of atomic oxygen density in an atmospheric pressure air plasma jet

    OpenAIRE

    Conway, Jim; Gogna, G; Gaman, C.; Turner , MM; Daniels, Stephen

    2015-01-01

    Atomic Oxygen density is measured in an air atmospheric jet system using Two-photon Absorption Laser Induced Fluorescence (TALIF). The TALIF system is calibrated using photolysis of molecular oxygen (O2). The RF power coupled into the plasma is varied and the resulting atomic oxygen density in the plasma plume measured.

  11. Fluorescent atom coincidence spectroscopy of extremely neutron-deficient barium isotopes

    International Nuclear Information System (INIS)

    Fluorescent atom coincidence spectroscopy (FACS) has been used to measure the nuclear mean square radii and moments of the extremely neutron-deficient isotopes 120-124Ba. At N=65 an abrupt change in nuclear mean square charge radii is observed which can be understood in terms of the occupation of the spin-orbit partner g7/2 5/2[413] neutron and g9/2 9/2[404] proton orbitals and the consequent enhancement of the n-p interaction. (orig.)

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

    International Nuclear Information System (INIS)

    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 SnH4 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.

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

    Science.gov (United States)

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

    2016-04-01

    A novel dielectric barrier discharge reactor (DBDR) was utilized to trap/release arsenic coupled to hydride generation atomic fluorescence spectrometry (HG-AFS). On the DBD principle, the precise and accurate control of trap/release procedures was fulfilled at ambient temperature, and an analytical method was established for ultratrace arsenic in real samples. Moreover, the effects of voltage, oxygen, hydrogen, and water vapor on trapping and releasing arsenic by DBDR were investigated. For trapping, arsenic could be completely trapped in DBDR at 40 mL/min of O2 input mixed with 600 mL/min Ar carrier gas and 9.2 kV discharge potential; prior to release, the Ar carrier gas input should be changed from the upstream gas liquid separator (GLS) to the downstream GLS and kept for 180 s to eliminate possible water vapor interference; for arsenic release, O2 was replaced by 200 mL/min H2 and discharge potential was adjusted to 9.5 kV. Under optimized conditions, arsenic could be detected as low as 1.0 ng/L with an 8-fold enrichment factor; the linearity of calibration reached R(2) > 0.995 in the 0.05 μg/L-5 μg/L range. The mean spiked recoveries for tap, river, lake, and seawater samples were 98% to 103%; and the measured values of the CRMs including GSB-Z50004-200431, GBW08605, and GBW(E)080390 were in good agreement with the certified values. These findings proved the feasibility of DBDR as an arsenic preconcentration tool for atomic spectrometric instrumentation and arsenic recycling in industrial waste gas discharge. PMID:26976077

  14. Determination of Palladium in Resin by Lead Fire Assaying-Flame Atomic Absorption Spectrometric Method%铅试金富集-火焰原子吸收光谱法测定树脂中钯

    Institute of Scientific and Technical Information of China (English)

    王芳; 陈小兰; 林海山; 李小玲; 肖红新

    2013-01-01

    通过铅试金富集树脂中的钯并用银作钯灰吹保护,得到的银钯合粒用王水溶解,在5%的盐酸介质中,采用原子吸收光谱法测定钯,该法测钯的相对标准偏差RSD为0.53%,加标回收率在99.04%~100.10%之间。%Palladium in resin was enriched by lead assaying, using silver as a protective agent to produce silver-palladium alloy, and then the alloy was dissolved in aqua regia. Air acetylene flame atomic absorption spectrometric method was used to determinate palladium in 5%hydrochloric acid solution. The relative standard deviation (RSD) in determination of palladium is 0.53%and the recovery rate is between 99.04%~100.10%.

  15. Semiconductor Nanomaterials-Based Fluorescence Spectroscopic and Matrix-Assisted Laser Desorption/Ionization (MALDI Mass Spectrometric Approaches to Proteome Analysis

    Directory of Open Access Journals (Sweden)

    Suresh Kumar Kailasa

    2013-12-01

    Full Text Available Semiconductor quantum dots (QDs or nanoparticles (NPs exhibit very unusual physico-chemcial and optical properties. This review article introduces the applications of semiconductor nanomaterials (NMs in fluorescence spectroscopy and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS for biomolecule analysis. Due to their unique physico-chemical and optical properties, semiconductors NMs have created many new platforms for investigating biomolecular structures and information in modern biology. These semiconductor NMs served as effective fluorescent probes for sensing proteins and cells and acted as affinity or concentrating probes for enriching peptides, proteins and bacteria proteins prior to MALDI-MS analysis.

  16. Interactions between fluorescence of atomically layered graphene oxide and metallic nanoparticles

    Science.gov (United States)

    Wang, Yu; Li, Shao-Sian; Yeh, Yun-Chieh; Yu, Chen-Chieh; Chen, Hsuen-Li; Li, Feng-Chieh; Chang, Yu-Ming; Chen, Chun-Wei

    2013-01-01

    Graphene oxide (GO) demonstrates interesting photoluminescence (PL) because of its unique heterogeneous atomic structure, which consists of variable sp2- and sp3-bonded carbons. In this study, we report the interaction between the luminescence of GO ranging from a single atomic layer to few-layered thin films and localized surface plasmon resonance (LSPR) from silver nanoparticles (Ag NPs). The photoluminescence of GO in the vicinity of the Ag NPs is enhanced significantly due to the near-field plasmonic effect by coupling electron-hole pairs of GO with oscillating electrons in Ag NPs, leading to an increased PL intensity and a decreased PL decay lifetime. The maxima 30-fold enhancement in PL intensity is obtained with an optimized film thickness of GO, and the luminescence image from a single atomic layer GO sheet is successfully observed with the assistance of the LSPR effect. The results provide an ideal platform for exploring the interactions between the fluorescence of two-dimensional layered materials and the LSPR effect.Graphene oxide (GO) demonstrates interesting photoluminescence (PL) because of its unique heterogeneous atomic structure, which consists of variable sp2- and sp3-bonded carbons. In this study, we report the interaction between the luminescence of GO ranging from a single atomic layer to few-layered thin films and localized surface plasmon resonance (LSPR) from silver nanoparticles (Ag NPs). The photoluminescence of GO in the vicinity of the Ag NPs is enhanced significantly due to the near-field plasmonic effect by coupling electron-hole pairs of GO with oscillating electrons in Ag NPs, leading to an increased PL intensity and a decreased PL decay lifetime. The maxima 30-fold enhancement in PL intensity is obtained with an optimized film thickness of GO, and the luminescence image from a single atomic layer GO sheet is successfully observed with the assistance of the LSPR effect. The results provide an ideal platform for exploring the

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

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Luis Claudio de; Silva, Adriana Mascarenhas Martins da; Gomide, Ricardo Goncalves; Silva, Ieda de Souza, E-mail: luis.claudio@ctmsp.mar.mil.br, E-mail: adriana@ctmsp.mar.mil.br, E-mail: gomide@ctmsp.mar.mil.br, E-mail: ieda@ctmsp.mar.mil.br [Centro Tecnologico da Marinha em Sao Paulo (CEA/CTMSP), Ipero, SP (Brazil). Centro Experimental Aramar

    2013-07-01

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

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Engstroem, Johan

    2001-01-01

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

  20. Spectrometric techniques 4

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume IV discusses three widely diversified areas of spectrometric techniques. The book focuses on three spectrometric methods. Chapter 1 discusses the phenomenology and applications of Coherent Anti-Stokes Raman Spectroscopy (CARS), the most commonly used optical technique that exploit the Raman effect. The second chapter is concerned with diffraction gratings and mountings for the Vacuum Ultraviolet Spectral Region. Chapter 3 accounts the uses of mass spectrometry, detectors, types of spectrometers, and ion sources. Physicists and chemists will find the book a go

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

    Czech Academy of Sciences Publication Activity Database

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

    2014-01-01

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

  2. Real-Time Near-Field Terahertz Imaging with Atomic Optical Fluorescence

    CERN Document Server

    Wade, Christopher G; de Melo, Natalia R; Kondo, Jorge M; Adams, Charles S; Weatherill, Kevin J

    2016-01-01

    Terahertz (THz) near-field imaging is a flourishing discipline [1], with applications from fundamental studies of beam propagation [2,3] to the characterisation of metameterials [4,5] and waveguides [6,7]. Beating the diffraction limit typically involves rastering structures or detectors with length scale shorter than the radiation wavelength; in the THz domain this has been achieved using a number of techniques including scattering tips [8,9] and apertures [10]. Alternatively, mapping THz fields onto an optical wavelength and imaging the visible light removes the requirement for scanning a local probe, speeding up image collection times [11,12]. Here we report THz to optical conversion using a gas of highly excited `Rydberg' atoms. By collecting THz-induced optical fluorescence we demonstrate a real-time image of a THz standing wave and we use well-known atomic properties to calibrate the THz field strength. The mono-atomic gas does not distort the THz field and offers the potential to immerse structures wit...

  3. Combined atomic force and fluorescence microscopy to study lipid transfer from lipoproteins to biomembranes

    International Nuclear Information System (INIS)

    Biological cells notice there environment via highly sensitive receptor-ligand interactions. The involved receptors reside at the cellular plasma membrane and react along complex molecular processes to the external stimulus. The spatial arrangement of the receptors affect their function strongly. By stimulating specific receptors -molecule by molecule- we can characterize their function. Atomic Force Microscopy (AFM) enables controlled stimulation of single receptor molecules. For this purpose the corresponding ligand is attached via a flexible linker to the cantilever tip. In contrast, fluorescence microscopy allows for measuring the time response of the signal processing, even at the single molecule level. It is the combination of both approaches, however, which paves the way for reaching new levels of understanding of cellular processes, as molecular trigger set by the functionalized AFM tip can be directly correlated to the cellular response measured by fluorescence microscopy. In this thesis, I firstly developed the instrumentation for combined and fully synchronized force and fluorescence microscopy, down to the level of single molecules. Secondly, I applied the new instrumentation to study the transfer of individual lipid molecules out of an HDL-particle into supported lipid bilayers, which serve as well defined model membranes. In particular, the transfer of fluorescently labeled lipids as a function of the receptor for selective cholesterol uptake was of major interest. It is generally assumed that this process is a receptor-mediated transfer of lipid from the particle directly into the cellular plasma membrane. By analyzing the interaction of HDL-particles and a supported lipid bilayer, I could demonstrate that cholesterol can indeed be transferred from an HDL particle to the bilayer without the need for a receptor; for cholesteryl ester, no transfer was observable. The ability to monitor released lipids and to adjust contact times or contact forces let

  4. Time-resolved fluorescence spectroscopy of matrix-isolated silver atoms after pulsed excitation of inner-shell transitions

    Science.gov (United States)

    Hebert, T.; Wiggenhauser, H.; Schriever, U.; Kolb, D. M.

    1990-02-01

    The energy dissipation in matrix-isolated silver atoms after pulsed vacuum ultraviolet (VUV) excitation of 4d-5p transitions has been studied by time-resolved fluorescence spectroscopy. The decay behavior of the various fluorescence bands has been analyzed and a model for the relaxation process proposed within the framework of a two-dimensional configuration-coordinate diagram. If minute quantities of Ag2 are present in the matrix, the analysis requires consideration of energy transfer between silver atoms and dimers.

  5. Velocity and electronic state distributions of sputtered Fe atoms by laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Velocity distributions and relative populations in the fine-structure levels of the a5D/sub J/ ground state of Fe atoms, produced by sputtering with 3 keV argon ions, have been investigated by Doppler shifted laser induced fluorescence. The laser system employs a single-mode, scanning ring dye laser, amplified by a sequence of three excimer-pumped flowing-dye cells. Frequency doubling in a KD*P crystal was used to produce high energy (> .5 mJ) pulses of narrowband tunable UV output near 300 nm. Laser power influence on effective velocity bandwidth was investigated. Favorable light-collection geometry minimized distortion of the velocity spectra from apparatus-averaging effects. In impurity flux diagnostic applications in fusion devices, substantial spatial averaging may occur. In the latter case, the narrow velocity bandwidth (70 m/s, transform limit) of the present laser system is particularly useful

  6. Probing intra-molecular mechanics of single circularly permuted green fluorescent protein with atomic force microscopy

    International Nuclear Information System (INIS)

    We investigated the mechanical unfolding of single circularly permuted green fluorescent protein (cpGFP) with atomic force microscopy (AFM). The molecule was stretched from its N- and C-termini by an external force causing an elongation of the polypeptide chain up to its full length. The features of the force-extension (F-E) curves were found to depend on the stretching speed. At fast speeds, we detected one peak in the F-E curves before final rupture of the extended molecule, which we interpreted as the unfolding of two terminal halves within cpGFP. We observed several more force peaks in a sawtooth pattern at much slower speeds, and explained the appearance of such force peaks as cooperative unfolding of the hidden sub-structures inside each terminal half

  7. Atomic layer deposition to prevent metal transfer from implants: An X-ray fluorescence study

    Science.gov (United States)

    Bilo, Fabjola; Borgese, Laura; Prost, Josef; Rauwolf, Mirjam; Turyanskaya, Anna; Wobrauschek, Peter; Kregsamer, Peter; Streli, Christina; Pazzaglia, Ugo; Depero, Laura E.

    2015-12-01

    We show that Atomic Layer Deposition is a suitable coating technique to prevent metal diffusion from medical implants. The metal distribution in animal bone tissue with inserted bare and coated Co-Cr alloys was evaluated by means of micro X-ray fluorescence mapping. In the uncoated implant, the migration of Co and Cr particles from the bare alloy in the biological tissues is observed just after one month and the number of particles significantly increases after two months. In contrast, no metal diffusion was detected in the implant coated with TiO2. Instead, a gradient distribution of the metals was found, from the alloy surface going into the tissue. No significant change was detected after two months of aging. As expected, the thicker is the TiO2 layer, the lower is the metal migration.

  8. Determination of divalent iron content in igneous rocks of ultrabasic, basic and intermediate compositions by a wavelength-dispersive X-ray fluorescence spectrometric method

    International Nuclear Information System (INIS)

    This paper proposes the quantitative wavelength-dispersive X-ray fluorescence (XRF) technique of divalent iron content determination in igneous rocks and reports specifics of this technique in terms of classifying rocks into ultrabasic, basic, intermediate and acid ones. Unlike the widely used technique of titration, the proposed XRF technique does not require a labor-consuming procedure for sample preparation. In the fields of FeKβ5 line, and FeKβ′ and FeKβ″ satellites relative intensities of XRF emission spectrum lines are dependent on the valence state of iron in minerals. The ratio FeKβ5/FeKβ1,3 is preferred as the analytical parameter. The XRF method allows divalent iron content (expressed as FeO oxide) over 1.5% to be measured in igneous rocks of ultrabasic and basic compositions by the common calibration equation with the error below 10 rel. %, that is comparable with the error of titrimetric analysis. The samples of igneous rocks of intermediate composition and granodiorites should be analyzed using calibration equations obtained with certified reference materials corresponding in composition to the study samples. For the samples of alkaline rocks the errors of FeO content determination might be in excess of 50 rel. %. - Highlights: • The wavelength-dispersive X-ray fluorescence method allows the determination of divalent iron contents. • Separate calibrations should be used for different types of igneous rocks. • Errors of X-ray fluorescence method and titrimetric analysis are comparable

  9. Fluorescence and atomic force microscopy to visualize the interaction of HDL particles with lipid membranes

    International Nuclear Information System (INIS)

    Full text: High density lipoprotein (HDL) plays a key role in cholesterol homeostasis: cholesterol-loaded HDL particles are transported from non-hepatic peripheral tissue to the liver, where they unload their cargo via receptor-mediated selective uptake. It is astonishing that – although blood levels of HDL are broadly used in diagnosis for the prognosis of developing cardiovascular disease – the cholesterol uptake mechanisms are still poorly understood. Particularly, it remains unclear how the amphipathic cholesterol crosses the aqueous phase between the HDL particle and the cell membrane. We applied state-of-the-art high-resolution and ultra-sensitive force and fluorescence microscopy techniques to image directly the interaction of HDL particles with the target membrane. Using highspeed atomic-force microscopy (AFM) we made a surprising discovery: when added to membranes, we observed HDL particles to integrate into the interleaflet core of the bilayer, generating 'nanoblisters' with a size below 10 nm. Amphipathic cargo was able to leave such blisters, whereas hydrophobic cargo such as cholesteryl-ester remained associated with the particles. Using a combined fluorescence and force microscopy system we could directly visualize the transfer of single cargo molecules into supported lipid bilayers. Particularly, we compared the transfer of the fluorescently labelled amphiphilic DiI and Bodipy-labelled cholesterol with the hydrophobic Bodipy-labelled cholesteryl- ester. Our experiments revealed that i) cargo transfer requires contact; ii) only amphiphilic cargo is transferred. Interestingly, membrane elasticity was found to be crucial for the fusion: only highly elastic (and thus cholesterol-poor) membranes facilitate particle fusion, whereas inelastic cholesterol-rich membranes prevented the fusion. Live cell experiments show that the plasma membrane itself regulates a cell’s cholesterol demand: high cholesterol levels act repulsive, low cholesterol levels

  10. Method of trivalent chromium concentration determination by atomic spectrometry

    Science.gov (United States)

    Reheulishvili, Aleksandre N.; Tsibakhashvili, Neli Ya.

    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.

  11. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC system

  12. Construction and performance of a time-multiplex multiple-slit flame atomic fluorescence spectrometer for multi-element analysis

    International Nuclear Information System (INIS)

    The design and performance characteristics of a new multi-element flame atomic fluorescence spectrometer are presented. Radiation from four-hollow-cathode tubes is directed onto an unsheathed air-hydrogen flame. The resulting atomic fluorescence is viewed by a special monochromator with a separate exit slit for each element. The light exiting from all slits is directed onto a single photomultiplier tube. The fluorescence signals from different elements are distinguished by a time multiplex approach. Single-element detection limits for ten elements and multi-element detection limits for four elements are presented. The degradation of detection limits by flame background emission noise and effect of flame composition on performance are discussed. Better than 10% is obtained for moderate analyte concentrations. (Auth.)

  13. Determination of divalent iron content in igneous rocks of ultrabasic, basic and intermediate compositions by a wavelength-dispersive X-ray fluorescence spectrometric method

    Science.gov (United States)

    Chubarov, Victor M.; Finkelshtein, Alexandr L.

    2015-05-01

    This paper proposes the quantitative wavelength-dispersive X-ray fluorescence (XRF) technique of divalent iron content determination in igneous rocks and reports specifics of this technique in terms of classifying rocks into ultrabasic, basic, intermediate and acid ones. Unlike the widely used technique of titration, the proposed XRF technique does not require a labor-consuming procedure for sample preparation. In the fields of FeKβ5 line, and FeKβ‧ and FeKβ″ satellites relative intensities of XRF emission spectrum lines are dependent on the valence state of iron in minerals. The ratio FeKβ5/FeKβ1,3 is preferred as the analytical parameter. The XRF method allows divalent iron content (expressed as FeO oxide) over 1.5% to be measured in igneous rocks of ultrabasic and basic compositions by the common calibration equation with the error below 10 rel. %, that is comparable with the error of titrimetric analysis. The samples of igneous rocks of intermediate composition and granodiorites should be analyzed using calibration equations obtained with certified reference materials corresponding in composition to the study samples. For the samples of alkaline rocks the errors of FeO content determination might be in excess of 50 rel. %.

  14. Spectrometric techniques 3

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume III presents the applications of spectrometric techniques to atmospheric and space studies. This book reviews the spectral data processing and analysis techniques that are of broad applicability.Organized into five chapters, this volume begins with an overview of the instrumentation used for obtaining field data. This text then reviews the contribution that space-borne spectroscopy in the thermal IR has made to the understanding of the planets. Other chapters consider the instruments that have recorded the planetary emission spectra. This book discusses as well

  15. Enrichment of trace amounts of copper(II) ions in water samples using octadecyl silica disks modified by a Schiff base ionophore prior to flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Fathi, S.A.M. [Department of Chemistry, Faculty of Science, Zanjan University, PO Box 45195-313 Zanjan (Iran, Islamic Republic of); Yaftian, M.R. [Department of Chemistry, Faculty of Science, Zanjan University, PO Box 45195-313 Zanjan (Iran, Islamic Republic of)], E-mail: yaftian@znu.ac.ir

    2009-05-15

    Bis(5-bromo-2-hydroxybenzaldehyde)-1,2-propanediimine is synthesized by the reaction of 5-bromo-2-hydroxybenzaldehyde and 1,2-diaminopropane in ethanol. This ligand is used as a modifier of octadecyl silica disks for preconcentration of trace amounts of copper(II) ions, followed by nitric acid elution and flame atomic absorption spectrometric (FAAS) determination. The effect of parameters influencing the extraction efficiency, i.e. pH of the sample solutions, amount of the Schiff base, type and volume of stripping reagent, sample and eluent flow rates were evaluated. Under optimum experimental conditions, the capacity of the membrane disks modified by 4 mg of the ligand was found to be 247.7 ({+-}2.1) {mu}g of copper. The detection limit and the concentration factor of the presented method are 2.4 ng/l and greater than 400, respectively. The method was applied to the extraction, recovery and detection of copper in different synthetic and water samples.

  16. 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)

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

    International Nuclear Information System (INIS)

    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-1 phosphoric acid, 1 mol L-1 nitric acid, aqua regia, 1 mol L-1 sulfuric acid and 6 mol L-1 hydrochloric acid. The extraction with aqua regia showed a clear interconversion of the species during the process, being H2SO4 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-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)

  18. Determination of cadmium in water samples by fast pyrolysis-chemical vapor generation atomic fluorescence spectrometry

    Science.gov (United States)

    Zhang, Jingya; Fang, Jinliang; Duan, Xuchuan

    2016-08-01

    A pyrolysis-vapor generation procedure to determine cadmium by atomic fluorescence spectrometry has been established. Under fast pyrolysis, cadmium ion can be reduced to volatile cadmium species by sodium formate. The presence of thiourea enhanced the efficiency of cadmium vapor generation and eliminated the interference of copper. The possible mechanism of vapor generation of cadmium was discussed. The optimization of the parameters for pyrolysis-chemical vapor generation, including pyrolysis temperature, amount of sodium formate, concentration of hydrochloric acid, and carrier argon flow rate were carried out. Under the optimized conditions, the absolute and concentration detection limits were 0.38 ng and 2.2 ng ml- 1, respectively, assuming that 0.17 ml of sample was injected. The generation efficiency of was 28-37%. The method was successfully applied to determine trace amounts of cadmium in two certified reference materials of Environmental Water (GSB07-1185-2000 and GSBZ 50009-88). The results were in good agreement with the certified reference values.

  19. Elasticity Maps of Living Neurons Measured by Combined Fluorescence and Atomic Force Microscopy

    CERN Document Server

    Spedden, Elise; Naumova, Elena N; Kaplan, David L; Staii, Cristian

    2013-01-01

    Detailed knowledge of mechanical parameters such as cell elasticity, stiffness of the growth substrate, or traction stresses generated during axonal extensions is essential for understanding the mechanisms that control neuronal growth. Here we combine Atomic Force Microscopy based force spectroscopy with Fluorescence Microscopy to produce systematic, high-resolution elasticity maps for three different types of live neuronal cells: cortical (embryonic rat), embryonic chick dorsal root ganglion, and P-19 (mouse embryonic carcinoma stem cells) neurons. We measure how the stiffness of neurons changes both during neurite outgrowth and upon disruption of microtubules of the cell. We find reversible local stiffening of the cell during growth, and show that the increase in local elastic modulus is primarily due to the formation of microtubules. We also report that cortical and P-19 neurons have similar elasticity maps, with elastic moduli in the range 0.1-2 kPa, with typical average values of 0.4 kPa (P-19) and 0.2 k...

  20. Determination of mercury by intermittent flow electrochemical cold vapor generation coupled to atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    A novel method for determination of mercury was developed using an intermittent flow electrochemical cold vapor generation coupled to atomic fluorescence spectrometry (IF-ECVG-AFS). The mercury vapor was generated on the surface of glassy carbon cathode in the flow cell. The operating conditions for the electrochemical generation of mercury vapor were investigated in detail, and the interferences from various ions were evaluated. Under the optimized conditions, no evident memory effects of mercury were observed. The calibration curve was linear up to 5 μg L-1 Hg at 0.54 A cm-2. A detection limit of 1.2 ng L-1 Hg and a relative standard deviation of 1.8% for 1 μg L-1 Hg were obtained. The accuracy of method was verified by the determination of mercury in the certified reference human hair. The ECVG avoided the use of reductants, thereby greatly reducing the contamination sources. In addition, the manifold of IF-ECVG-AFS was simple and amenable to automation

  1. Using laser-induced fluorescence spectroscopy method for investigating iron atom behaviour on the TO-2 tokamak plasma filament periphery

    International Nuclear Information System (INIS)

    Theoretical prerequisites and methods for laser fluorescent spectroscopy (LFS) to measure heavy impurity concentration in a tokamak with TO-2 diverter are described with the purpose of organizing plasma diagnostics in the T-15 tokamak. Results of measuring iron atom absolute concentrations during discharge in the TO-2 tokamak near-the well area by LFS method are presented. Preliminary experiments on detecting channel absolute calibration by the fluorescent signal of a tube with a hollow cathode, pumped by probing laser radiation are conducted

  2. Atomic absorption spectrometric determination of some metal ions after preconcentration by solid phase extraction using amberlite XAD 16 resin loaded with thenoyltrifluoroacetone

    International Nuclear Information System (INIS)

    Complete text of publication follows. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry is often difficult because of insufficient sensitivity and selectivity of the methods used. For this reason, the preliminary separation and preconcentration of trace elements from the matrix are often required. Solid phase extraction shows several major advantages such as simplicity, rapidity and high enrichment factor, the ability of combination with different detection techniques in the form of on-line or off-line mode and finally cost saving (Tokalioglu et al., Microchim Acta 164 (2009) 471-477.). A new solid phase extraction method for the separation and preconcentration of Cu(II), Pb(II), Ni(II), Co(II), Mn(II) and Fe(III) ions was developed. As solid phase material, Amberlite XAD-16 resin loaded with thenoyltrifluoroacetone (TTA) was used. For this purpose, 0.5 g of the resin was saturated with 10 mL of 0.5% (w/v) TTA solution. After preconcentrating, the metals retained on the resin were eluted with 10 mL of 2 mol L-1 HCl and then determined by flame atomic absorption spectrometry. The effect of some parameters for the preconcentration of the metal ions was investigated. The optimum pH was found as 6. Eluent for quantitative elution was 10 mL of 2 mol L-1 HCl.

  3. Two-photon absorption laser induced fluorescence measurement of atomic oxygen density in an atmospheric pressure air plasma jet

    Science.gov (United States)

    Conway, J.; Gogna, G. S.; Gaman, C.; Turner, M. M.; Daniels, S.

    2016-08-01

    Atomic oxygen number density [O] is measured in an air atmospheric pressure plasma jet (APPJ) using two-photon absorption laser induced fluorescence (TALIF). Gas flow is fixed at 8 slpm, the RF power coupled into the plasma jet varied between 5 W and 20 W, and the resulting changes in atomic oxygen density measured. Photolysis of molecular oxygen is employed to allow in situ calibration of the TALIF system. During calibration, O2 photo-dissociation and two-photon excitation of the resulting oxygen atoms are achieved within the same laser pulse. The atomic oxygen density produced by photolysis is time varying and spatially non-uniform which needs to be corrected for to calibrate the TALIF system for measurement of atomic oxygen density in plasma. Knowledge of the laser pulse intensity I 0(t), wavelength, and focal spot size allows correction factors to be determined using a rate equation model. Atomic oxygen is used for calibration and measurement, so the laser intensity can be increased outside the TALIF quadratic laser power dependence region without affecting the calibration reliability as the laser power dependence will still be the same for both. The atomic O density results obtained are not directly benchmarked against other known density measurement techniques. The results show that the plasma jet atomic oxygen content increases as the RF power coupled into the plasma increases.

  4. Atomic oxygen surface loss probability on silica in microwave plasmas studied by a pulsed induced fluorescence technique

    International Nuclear Information System (INIS)

    The aim of this paper is to determine the atomic oxygen surface loss probability on silica under microwave plasma conditions around 133 Pa (1 Torr). A pulsed induced fluorescence technique where a main long pulse creates the plasma and a shorter one re-excites atoms in the time post-discharge was used. The method and its validity under the present experimental conditions are discussed at large. The oxygen surface loss probability on silica is found to be around 3% under plasma conditions, while it is estimated to be two orders of magnitude lower for a surface not submitted to the plasma

  5. Potential of two-line atomic fluorescence for temperature imaging in turbulent indium-oxide-producing flames

    International Nuclear Information System (INIS)

    The applicability of two-line atomic fluorescence (TLAF) for temperature imaging in an indium-based flame spray pyrolysis (FSP) process is demonstrated using a single tunable optical parametric oscillator (OPO) to generate the required excitation wavelengths consecutively. Single-shot images of the detected fluorescence signals demonstrate that the signal levels in the flame are suitable for evaluation of temperature and verify the capability and potential of the measurement technique directly during particle formation without additional indium seeding. Qualitative averaged two-dimensional temperature distributions in the FSP flame are presented, showing the influence of varying sheath gas flow rates on the resulting temperature distribution. With the addition of a second OPO and detection system, the two fluorescence signals acquired consecutively in this work could be obtained simultaneously and enable spatio-temporally resolved single-shot temperature measurements in flame synthesis processes of indium-containing nanoparticles

  6. Potential of two-line atomic fluorescence for temperature imaging in turbulent indium-oxide-producing flames

    Energy Technology Data Exchange (ETDEWEB)

    Münsterjohann, Bettina; Huber, Franz J. T.; Klima, Tobias C.; Holfelder, Sandra; Engel, Sascha R. [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Lehrstuhl für Technische Thermodynamik (LTT) (Germany); Miller, Joseph D. [Aerospace Systems Directorate, Air Force Research Laboratory (United States); Meyer, Terrence R. [Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen Graduate School in Advanced Optical Technologies (SAOT) (Germany); Will, Stefan, E-mail: stefan.will@fau.de [Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), Lehrstuhl für Technische Thermodynamik (LTT) (Germany)

    2015-11-15

    The applicability of two-line atomic fluorescence (TLAF) for temperature imaging in an indium-based flame spray pyrolysis (FSP) process is demonstrated using a single tunable optical parametric oscillator (OPO) to generate the required excitation wavelengths consecutively. Single-shot images of the detected fluorescence signals demonstrate that the signal levels in the flame are suitable for evaluation of temperature and verify the capability and potential of the measurement technique directly during particle formation without additional indium seeding. Qualitative averaged two-dimensional temperature distributions in the FSP flame are presented, showing the influence of varying sheath gas flow rates on the resulting temperature distribution. With the addition of a second OPO and detection system, the two fluorescence signals acquired consecutively in this work could be obtained simultaneously and enable spatio-temporally resolved single-shot temperature measurements in flame synthesis processes of indium-containing nanoparticles.

  7. Speciation analysis of arsenic by hydride generation-cryotrapping-atomic fluorescence spectrometry: achieving extremely low detection limits with inexpensive instrumentation

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš; Svoboda, Milan; Selecká, Anna; Rychlovský, P.; Dědina, Jiří

    Buzios, Rio de Janeiro, 2011. TH43. ISBN 978-85-8006-046-1. [Colloquium Spectroscopicum Internationale /37./. 28.08.2011-02.09.2011, Buzios, Rio de Janeiro] R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : arsenic speciation analysis * hydride generation * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation

  8. Speciation analysis of arsenic by hydride generation-cryotrapping-atomic fluorescence spectrometry: achieving extremely low detection limits with inexpensive instrumentation

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš; Svoboda, Milan; Selecká, Anna; Rychlovský, P.; Dědina, Jiří

    Münster, 2011. FTM 17. [International Symposium on Metallomics /3./. 15.06.2011-18.06.2011, Münster] R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : arsenic speciation analysis * hydride generation * atomic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation http://www.metallomics2011.org/event/Metallomics2011/Scientific_program.html

  9. Ultratrace determination of mercury in water following EN and EPA standards using atomic fluorescence spectrometry.

    Science.gov (United States)

    Labatzke, Thomas; Schlemmer, Gerhard

    2004-02-01

    Chemical vapour generation has been used in combination with atomic fluorescence spectrometry to determine mercury at ultratrace concentrations down to 0.1 ng L(-1). A time-based injection of 1 mL of solution for measurement was sufficient to generate a steady-state detector response in the direct mode of measurement. The detection limit calculated from a ten-point calibration curve according to DIN 32645 was 0.26 ng L(-1). Instrument noise is limited by reflected radiation from the light source rather than by the dark current of the photomultiplier. The detection limit is directly influenced by the reagent blank which was 2 ng L(-1) in the experiments described. Focusing by amalgamation and subsequent thermal desorption generates a detector response which is about eight times higher in peak intensity and about twice as large in integrated intensity. The detection limit under these conditions is 0.09 ng L(-1) which can be further improved by preconcentration of larger volumes of solution for measurement. The cycle time for one individual reading is about 40 s without amalgamation and 125 s with amalgamation. The linear dynamic range of the system is five orders of magnitude with a single photomultiplier gain setting. The carry-over is less than 0.3% in direct measurement mode. Reference water samples and a surface water containing approximately 5 ng L(-1) were used to prove the validity of the method for real samples. Good accuracy and recoveries of 103% were calculated using the fast direct determination technique. PMID:14673566

  10. Atomic-absorption spectrometric, neutron-activation and radioanalytical techniques for the determination of trace metals in environmental, biochemical and toxicological research

    International Nuclear Information System (INIS)

    Radioanalytical techniques and atomic-absorption spectrometry have been used for the micro-determination of vanadium in biological specimens such as human tissues and body fluids in environmental, biochemical and toxicological research. The use of 48V as a radiotracer permitted investigations on the vaporisation and retention mechanisms of vanadium. Higher vanadium oxides are probably converted into lower oxides, decomposing to VO in gaseous form, followed by the dissociation to 'free vanadium' and oxygen. It was found that about 20% of the 48V radioactivity was consistently retained in the graphite tube after 10 repeated introductions and firings of 50 μl of 50 ng ml-148V-labelled vanadium solution. However, the amount retained, probably in the form of carbide, does not vaporise under the conditions used for the analysis. Determinations of vanadium at the parts per billion level in 10 urine samples by neutron-activation analysis and by graphite furnace atomic-absorption spectrometry showed agreement that can be considered satisfactory for practical purposes. (author)

  11. A COMPARATIVE ANALYSIS ON CALCIUM RELEASE FROM ENAMEL AFTER TREATMENT WITH VARIOUS REMINERALIZING AGENTS AT A PH 4.5 : AN ATOMIC ABSORBTION SPECTROMETRIC ANALYSIS

    Directory of Open Access Journals (Sweden)

    Shetty Shishir

    2013-07-01

    Full Text Available Focus of this study was to compare the amount of calcium released from enamel treated with different remineralizing agents at pH 4.5 using atomic spectrophotometric analysis. The present study was designed to assess the calcium release from enamel when subjected to an acid challenge. Enamel samples were divided into four groups of which intact enamel served the purpose of control group and other three groups were based on the remineralizing agents used (CPP-ACP [GC Tooth Mousse], CPP-ACPF [GC Tooth Mousse Plus], 0.044 % Sodium Fluoride [Phosflur]. All the groups of enamel samples were initially demineralized and followed up with remineralisation by adopting the pH cycling model. Acetate buffer was prepared at a specific pH of 4.5. The enamel samples were subjected to acid challenge in presence of a magnetic stirrer and buffer solution were pipetted at specific time intervals for pH 4.5. The solutions collected were transferred into sterile containers and subjected to atomic spectrometry analysis.

  12. 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

  13. Selective cloud point extraction and preconcentration of trace amounts of silver as a dithizone complex prior to flame atomic absorption spectrometric determination

    Energy Technology Data Exchange (ETDEWEB)

    Manzoori, Jamshid L.; Karim-Nezhad, Ghasem

    2003-05-19

    Dithizone (diphenylthiocarbazone) was used as a complexing agent in cloud point extraction for the first time and applied for selective preconcentration of trace amounts of silver. The analyte in the initial aqueous solution was acidified with sulfuric acid (pH<1) and Triton X-114 was added as a surfactant. After phase separation, based on the cloud point separation of the mixture, the surfactant rich phase was diluted with tetrahydrofuran (THF) and the analyte determined in the enriched solution by flame atomic absorption spectrometry. After optimization of the complexation and extraction conditions, a preconcentration factor of 43 was obtained for only 10 ml of sample. The analytical curve was linear in the range of 3-200 ng ml{sup -1} and the limit of detection was 0.56 ng ml{sup -1}. The proposed method was applied to the determination of silver in water samples.

  14. Graphite furnace and hydride generation atomic absorption spectrometric determination of cadmium, lead, and tin traces in natural surface waters: Study of preconcentration technique performance

    International Nuclear Information System (INIS)

    In this study three major types of preconcentration methods based upon different principles (cation exchange, physical absorption and hydrophobic extraction) were evaluated and optimized for the extraction and determination of three highly toxic heavy metals namely Cd, Pb and Sn by graphite furnace and hybrid generation atomic absorption spectrometry in real samples. The optimum analytical conditions were examined and the analytical features of each method were revealed and compared. Detection limits as low as 0.003-0.025 μg L-1 for Cd2+, 0.05-0.10 μg L-1 for Pb2+ and 0.1-0.25 μg L-1 for Sn4+ depending on the extraction method were obtained with RSD values between 3.08% and 6.11%. A preliminary assessment of the pollution status of three important natural ecosystems in Epirus region (NW Greece) was performed and some early conclusions were drawn and discussed

  15. Preconcentration and atomic absorption spectrometric determination of cadmium, cobalt, copper, iron, lead, manganese, nickel and zinc in water samples using 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone

    International Nuclear Information System (INIS)

    The reagent 6-methyl-2-pyridinecarboxaldehyde-4-phenyl-3-thiosemicarbazone (MPAPT) has been examined for the pre-concentration of metal ions and determination using air acetylene flame atomic absorption spectrometer. The method is based on the complexation and extraction of cadmium (II), cobalt(III), copper(II), lead(II), nickel(II), iron(II), iron(II), manganese(II) and zinc(II) in chloroform. The metal iron are back extracted in nitric acid (1:1) or after evaporation of solvent the residue is digested in nitric acid. After necessary adjustment of volume the metal ions were determined in aqueous solution. Pre-concentration is obtained 10-25 times. Metal ions recovery was 95.4-100.8% with coefficient of variation 0.2-7.5%. The method used for the determination of metals in canal and sewerage waters, within 2-6433 mu g/L with C. V 0.-5.2%. (author)

  16. The determination of trace amounts of heavy metals in waters by a flow-injection system including ion-exchange preconcentration and flame atomic absorption spectrometric detection

    International Nuclear Information System (INIS)

    The flow-injection system combines on-line ion-exchange preconcentration with atomic absorption spectrometry (a.a.s.) for the determination of traces (μg l-1) of heavy metals in water samples. A multifunctional rotary sampling valve which incorporated two parallel sampling columns allows sampling, exchange, elution and a.a.s. to be achieved sequentially. The increases in sensitivity for nickel, copper, lead and cadmium were 20-28-fold at a sampling rate of 40 h-1 with 5-ml samples. Relative standard deviations were 1.5-4.1%. The recoveries of these four metals added to tap, sea and polluted waters were generally satisfactory, except for cadmium in polluted water. The effects of column diameter and elution flow rates on sensitivity are discussed. Possible interferences are described. (Auth.)

  17. Characterization of national food agency shrimp and plaice reference materials for trace elements and arsenic species by atomic and mass spectrometric techniques

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Pedersen, Gitte Alsing; McLaren, J. W.

    1997-01-01

    absorption spectrometry, inductively coupled plasma mass spectrometry (ICP-MS) and isotope dilution ICP-MS. The contents of arsenobetaine and the tetramethylarsonium ion were determined by cation exchange high performance liquid chromatography (HPLC) coupled with ICP-MS, or coupled with ion-spray (IS) tandem......, drying, milling and sieving to collect the fraction of particles less than 150 mu m in sizer In this fraction the trace elements were homogeneously distributed using a 400 mg sample intake for analysis, The total track element concentrations were determined by graphite furnace and cold vapour atomic...... mass spectrometry (MS/MS) for qualitative verification, Based on a rigorous statistical analysis of the analytical data using the DANREF software, it was decided to assign certified values for mercury, cadmium and arsenic in the NFA Shrimp, and mercury, selenium and arsenic in the NFA Plaice...

  18. Generation of volatile copper species after in situ ionic liquid formation dispersive liquid-liquid microextraction prior to atomic absorption spectrometric detection.

    Science.gov (United States)

    Stanisz, Ewa; Zgoła-Grześkowiak, Agnieszka; Matusiewicz, Henryk

    2014-11-01

    The new procedure using in situ synthesis of ionic liquid extractant for dispersive liquid-liquid microextraction (in situ IL DLLME) combined with generation of volatile species prior to electrothermal atomic absorption spectrometry (ET AAS) for the determination of copper in soil samples was developed. Analytical signals were obtained without the back-extraction of copper from the IL phase prior to its determination. Under optimal conditions, the extraction in 10 mL of sample solution employing 8 μL of 1-hexyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide (HmimNTf2) (as the extraction solvent) was conducted. The ionic liquid served as two-task reagent: the efficient extractant and enhancement substance for generation step. The chemical generation of volatile species was performed by reduction of acidified copper solution (HCl 0.8 mol L(-1)) with NaBH4 (1.5%). Some essential parameters of the chemical generation such as NaBH4 and HCl concentrations, the kind and concentration of ionic liquid, carrier gas (Ar) flow rate, reaction and trapping time as well as pyrolysis and atomization temperatures were studied. For photogeneration the effect of the parameters such as the kind and concentration of low molecular weight organic acids and ionic liquid, carrier gas (Ar) flow rate, UV irradiation and ultrasonication time on the analytical signals were studied. The detection limit was found as 1.8 ng mL(-1) and the relative standard deviation (RSD) for seven replicate measurements of 100 µg mL(-1) in sample solution was 7%. The accuracy of the proposed method was evaluated by analysis of the certified reference materials. The measured copper contents in the reference materials were in satisfactory agreement with the certified values. The method was successfully applied to analysis of the soil and sediment samples. PMID:25127592

  19. Highly uniform holographic microtrap arrays for single atom trapping using a feedback optimization of in-trap fluorescence measurements.

    Science.gov (United States)

    Tamura, Hikaru; Unakami, Tomoyuki; He, Jun; Miyamoto, Yoko; Nakagawa, Ken'ichi

    2016-04-18

    We report on the novel optimization method to realize highly uniform microtrap arrays for single atom trapping with a spatial light modulator (SLM). This method consists of two iterative feedback loops with the measurements of both diffracted light intensities and in-trap fluorescence intensities from each microtrap. By applying this method to the single 87Rb atom trapping, we can reduce the variance of trap depths from 20.8% to 1.7% for 4 × 4 square arrays and less than 4% for various arrays with up to 62 sites. The detection error of individual single atoms is also reduced from 1.7% to 0.0054% on average. PMID:27137252

  20. Cloud point extraction and flame atomic absorption spectrometric determination of trace lead in freshwater fish%浊点萃取-火焰原子吸收光谱法测定淡水鱼中痕量铅

    Institute of Scientific and Technical Information of China (English)

    王秀峰; 李龙; 张春丽; 林朋; 崔书亚

    2012-01-01

    采用以双硫腙为络合剂、Triton X- 100为表面活性剂的新型浊点萃取体系富集淡水鱼中的痕量铅,并用火焰原子吸收光谱法对其进行测定.探讨了溶液pH、表面活性剂浓度、络合剂用量、平衡温度、平衡时间等对浊点萃取及测定灵敏度的影响,优化了实验条件.在最佳条件下测得铅的检出限为0.090μg/L,校准曲线相关系数为0.9999.该方法已用于淡水鱼中痕量铅的测定.%A new cloud point extraction-flame atomic absorption spectrometric method has been developed to determine trace lead. Dithizone was selected as the complex reagent and Triton X - 100 as the surfactant. Effects of pH, concentrations of surfactant and complex reagent, equilibrium temperature and time on the efficiency and sensitivity of cloud point extraction were investigated. Under optimal conditions, the calibration curve was linear over the concentration range of 0. 1 - 60μg/L with correlation coefficient of 0. 9999 and detection limit of 0. 090 μg/L. The present method was applied to the determination of trace lead in freshwater fish samples with satisfactory results.

  1. Collective resonance fluorescence in small and dense atom clouds: Comparison between theory and experiment

    CERN Document Server

    Jenkins, S D; Javanainen, J; Jennewein, S; Bourgain, R; Pellegrino, J; Sortais, Y R P; Browaeys, A

    2016-01-01

    We study the emergence of a collective optical response of a cold and dense $^{87}$Rb atomic cloud to a near-resonant low-intensity light when the atom number is gradually increased. Experimental observations are compared with microscopic stochastic simulations of recurrent scattering processes between the atoms that incorporate the atomic multilevel structure and the optical measurement setup. We analyze the optical response of an inhomogeneously-broadened gas and find that the experimental observations of the resonance line shifts and the total collected scattered light intensity in cold atom clouds substantially deviate from those of thermal atomic ensembles, indicating strong light-induced resonant dipole-dipole interactions between the atoms. At high densities, the simulations also predict a significantly slower decay of light-induced excitations in cold than in thermal atom clouds. The role of dipole-dipole interactions is discussed in terms of resonant coupling examples and the collective radiative exc...

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

    International Nuclear Information System (INIS)

    The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I). The analytical procedure involved the formation of understudy metals complex with bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation. Methanol acidified with 1 mol L-1 HNO3 was added to the surfactant-rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The concentration of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions, the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL-1 for Cd2+, Pb2+, Pd2+ and Ag+ along with preconcentration factors of 30 and enrichment factors of 48, 39, 32 and 42 for Cd2+, Pb2+, Pd2+ and Ag+, respectively, were obtained. The proposed cloud point extraction has been successfully applied for the determination of metal ions in real samples with complicated matrix such as radiology waste, vegetable, blood and urine samples.

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

    International Nuclear Information System (INIS)

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

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

    International Nuclear Information System (INIS)

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

  5. Flame atomic absorption spectrometric determination of μg amounts of Fe (III) ions after solid phase extraction using modified octadecyl silica membrane disks

    International Nuclear Information System (INIS)

    A simple, rapid and reliable method has been developed to selectively separate and concentrate ultra trace amounts of Fe (III) ions from aqueous samples for the measurement by flame atomic absorption spectrometry (FAAS). By the passage of aqueous samples through an octadecyl silica membrane disk modified by a recently synthesized Schiff base (Bis-(4-nitro phenyl azo) salisilidine-1,3-diamino propane), Fe(III) ions adsorb quantitatively and most of matrix elements will pass through the disk to drain. The retained iron ions are then stripped from the disk by minimal amount of 0.1 mol l-1 sulfuric acid as eluent. Extraction efficiency and the influence of pH, flow rates, amount of ligand, type and least amount of stripping acid as eluent were evaluated. The recovery of the iron from aqueous solution on the membrane disk modified with 3 mg Schiff's base was quantitative over pH 2-4.5. The linear dynamic range of the proposed method for Fe (III) ions was found in a wide concentration range of 0.20 (± 0.05)-680 (± 2) μg l-1. The detection limit and preconcentration factor of this solid phase extraction method were found 20.0 (± 0.7) ng l-1 and 100 respectively. The reproducibility of the procedure is at the most 1.5%

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-15

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

  7. A solid liquid extraction and preconcentration method for the atomic absorption spectrometric determination of trace cobalt in various alloys and biological samples

    International Nuclear Information System (INIS)

    Cobalt is quantitatively retained as cobalt-2-nitroso-4-sulfonic acid (nitros-S)-tetradecyldimethylbenzylammonium (TDBA+) ion-pair complex on microcrystalline naphthalene in the pH range 6.2-9.0 from a large volume of its aqueous solution of various complex samples. After filtration, the solid mass consisting of cobalt complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal is determined by flame atomic absorption spectrometry (FAAS). Cobalt complex can alternatively be quantitatively adsorbed on tetradecyldimethylbenzylammonium chloride-naphthalene adsorbent packed in a column and determined similarly. The calibration curve is linear over the concentration range 0.2-11.5 μg of cobalt in 5 ml of the final DMF solution. In this case, 0.2 μg of cobalt may be concentrated in a column from 250 ml of aqueous sample where its concentration is as low as 0.8 ng/ml. Eight replicate determinations of 3.0 μg of cobalt in the final DMF solution give a mean absorbance of 0.045 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption is 59 ng/ml. The interference of a large number of anions and cations on the determination of cobalt has been studied and the optimum conditions developed utilized for its trace determination in various alloys and biological samples. The method may also be used for the determination of cobalt in some environmental samples

  8. Ultrasound-assisted ionic liquid dispersive liquid-liquid microextraction combined with graphite furnace atomic absorption spectrometric for selenium speciation in foods and beverages.

    Science.gov (United States)

    Tuzen, Mustafa; Pekiner, Ozlem Zeynep

    2015-12-01

    A rapid and environmentally friendly ultrasound assisted ionic liquid dispersive liquid liquid microextraction (USA-IL-DLLME) was developed for the speciation of inorganic selenium in beverages and total selenium in food samples by using graphite furnace atomic absorption spectrometry. Some analytical parameters including pH, amount of complexing agent, extraction time, volume of ionic liquid, sample volume, etc. were optimized. Matrix effects were also investigated. Enhancement factor (EF) and limit of detection (LOD) for Se(IV) were found to be 150 and 12 ng L(-1), respectively. The relative standard deviation (RSD) was found 4.2%. The accuracy of the method was confirmed with analysis of LGC 6010 Hard drinking water and NIST SRM 1573a Tomato leaves standard reference materials. Optimized method was applied to ice tea, soda and mineral water for the speciation of Se(IV) and Se(VI) and some food samples including beer, cow's milk, red wine, mixed fruit juice, date, apple, orange, grapefruit, egg and honey for the determination of total selenium. PMID:26041239

  9. Development of on-line single-drop micro-extraction sequential injection system for electrothermal atomic absorption spectrometric determination of trace metals

    International Nuclear Information System (INIS)

    A novel automatic sequential injection (SI) single-drop micro-extraction (SDME) system is proposed as versatile approach for on-line metal preconcentration and/or separation. Coupled to electrothermal atomic absorption spectrometry (ETAAS) the potentials of this SI scheme are demonstrated for trace cadmium determination in water samples. A non-charged complex of cadmium with ammonium diethyldithiophosphate (DDPA) was produced and extracted on-line into a 60 μL micro-drop of di-isobutyl ketone (DIBK). The extraction procedure was performed into a newly designed flow-through extraction cell coupled on a sequential injection manifold. As the complex Cd(II)-DDPA flowed continuously around the micro-droplet, the analyte was extracting into the solvent micro-drop. All the critical parameters were optimized and offered good performance characteristics and high preconcentration ratios. For 600 s micro-extraction time, the enhancement factor was 10 and the sampling frequency was 6 h-1. The detection limit was 0.01 μg L-1 and the precision (RSD at 0.1 μg L-1 of cadmium) was 3.9%. The proposed method was evaluated by analyzing certified reference material

  10. Selective solid phase extraction of platinum on an ion imprinted polymers for its electrothermal atomic absorption spectrometric determination in environmental samples

    International Nuclear Information System (INIS)

    An ion-imprinted polymer (IIP) was obtained by copolymerization of methacrylic acid (as a functional monomer) and ethylene glycol dimethacrylate (as a crosslinking agent) in the presence of various chelators for Pt(II) ion and using 2,2'-azo-bis-isobutyronitrile as the initiator. Specifically, acetaldehyde thiosemicarbazone (AcTSn) and benzaldehyde thiosemicarbazone (BnTSn) were used as chelators. The IIPs were applied as sorbents for solid-phase extraction of Pt(II) and Pt(IV) ions from aqueous solutions. The effects of acidity and flow rate of the sample, of elution conditions and of potentially interfering ions were investigated. The imprinting effect of analyte is clearly demonstrated by the fact that only the IIP is capable of quantitative retention of Pt(II) and Pt(IV) ions. The method works best in the pH range from 0.5 to 1 and from 3.5 to 9.5. The ions can be recovered with an acidic solution of thiourea. The Pt-AcTSn polymer displays better sorption properties for the separation of analytes. The selectivity coefficients of the Pt-AcTSn and control polymers for Pt(IV) in the presence Pd(II), Rh(III), Ru(III), Al(III) and Cu(II) were calculated, and the sorbent capacity for Pt(IV) was found to be 4.56 μg g-1. The method was successfully applied to the determination of Pt(IV) by electrothermal atomic absorption spectrometry in tap water, tunnel dust and anode slime samples. (author)

  11. On-line sequential injection dispersive liquid-liquid microextraction system for flame atomic absorption spectrometric determination of copper and lead in water samples.

    Science.gov (United States)

    Anthemidis, Aristidis N; Ioannou, Kallirroy-Ioanna G

    2009-06-30

    A simple, sensitive and powerful on-line sequential injection (SI) dispersive liquid-liquid microextraction (DLLME) system was developed as an alternative approach for on-line metal preconcentration and separation, using extraction solvent at microlitre volume. The potentials of this novel schema, coupled to flame atomic absorption spectrometry (FAAS), were demonstrated for trace copper and lead determination in water samples. The stream of methanol (disperser solvent) containing 2.0% (v/v) xylene (extraction solvent) and 0.3% (m/v) ammonium diethyldithiophosphate (chelating agent) was merged on-line with the stream of sample (aqueous phase), resulting a cloudy mixture, which was consisted of fine droplets of the extraction solvent dispersed entirely into the aqueous phase. By this continuous process, metal chelating complexes were formed and extracted into the fine droplets of the extraction solvent. The hydrophobic droplets of organic phase were retained into a microcolumn packed with PTFE-turnings. A portion of 300 microL isobutylmethylketone was used for quantitative elution of the analytes, which transported directly to the nebulizer of FAAS. All the critical parameters of the system such as type of extraction solvent, flow-rate of disperser and sample, extraction time as well as the chemical parameters were studied. Under the optimum conditions the enhancement factor for copper and lead was 560 and 265, respectively. For copper, the detection limit and the precision (R.S.D.) were 0.04 microg L(-1) and 2.1% at 2.0 microg L(-1) Cu(II), respectively, while for lead were 0.54 microg L(-1) and 1.9% at 30.0 microg L(-1) Pb(II), respectively. The developed method was evaluated by analyzing certified reference material and applied successfully to the analysis of environmental water samples. PMID:19376348

  12. Electrothermal atomic absorption spectrometric determination of cadmium and lead in traces in aquatic systems following flotation by two chromium(III) collectors.

    Science.gov (United States)

    Kormusoska, Natasa Bakreska; Cundeva, Katarina; Stafilov, Trajce

    2009-10-01

    A fast flotation method for determination of cadmium and lead in aquatic systems by two chromium(III) collectors is described. The first collector is a colloid precipitate of hydrated chromium(III) oxide, Cr2O3 x xH2O, while the second is a bulk chromium(III) pentamethylenedithiocarbamate, Cr(PMDTC)3. Cadmium and lead present in water are incorporated into the collector mass at pH 7.5 by addition of 20 mg of Cr(III) and 0.4 mmol of pentamethyleneammonium pentamethylenedithiocarbamate, PMA-PMDTC, to 0.5 L water sample. A solid precipitate was separated from the processed water system by air bubbles. After dissolving with strong acid, the solution is tested by electrothermal atomic absorption spectrometry (ETAAS). The limit of detection for Cd by flotation/ETAAS method is 0.002 microg L(-1), while for Pb is 0.04 microg L(-1). The precision of the method is expressed as relative standard deviations ranging of 5.0% for Cd (concentration range from 0.1 to 0.5 microg L(-1)) and 4.25% for Pb (concentration range from 0.5 to 5 microg L(-1)). The characteristic mass (mass that gives an integrated absorbance of 0.0044 s) of 1.06 pg for Cd and 16.7 pg for Pb were obtained. The method was validated by the standard additions and by its application to the reference materials (Surface water-SPS-SW-1, River Thames Water-LGC-6019). PMID:19847715

  13. Separation and flame atomic absorption spectrometric determination of total chromium and chromium (III) in phosphate rock used for production of fertilizer.

    Science.gov (United States)

    El-Sheikh, Amjad H; Al-Degs, Yahya S; Sweileh, Jamal A; Said, Adi J

    2013-11-15

    Due to the commercial value of phosphate rock (PR) as a fertilizer precursor, it is necessary to investigate its heavy metals content. Chromium (Cr) may present as Cr(III) or Cr(VI) in PR; but quantitative differentiation between them is not an easy task. This is due to possible interconversion of Cr species during the digestion/leaching process. In this work, ultrasound digestion (USD) of PR was optimized (300 mg PR, 4.0 mL of 4.0 mol L(-1) nitric acid, 15 min sonication) for the sake of leaching Cr species prior to their determination by flame atomic absorption spectroscopy. Using multi-walled carbon nanotube (MWCNT) as adsorbent, solid phase extraction (SPE) was used to separate Cr(III) from the digestate at pH 9, while total Cr was estimated after reducing Cr(VI) into Cr(III). The optimum USD/SPE method gave LOQ and LOD of Cr(III) of 0.96 mg kg(-1) and 0.288 mg kg(-1), respectively. The method sensitivity was 1.44×10(-3) AU kg mg(-1) within the studied Cr concentration range (5-400 mg kg(-1)). The USD/SPE method was validated by analyzing lake sediments LKSD-4 certified reference material, and by comparison with classical digestion method (CD). Application of USD/SPE on Jordanian PR samples gave total Cr rang 29.1-122.0 mg kg(-1) (±1.4-6.3), while Cr(III) ranged between 23.8 and 101.7 mg kg(-1) (±1.3-5.5). AFPC Rock Check Program samples gave total Cr range 238.9-394.7 mg kg(-1) (±11.5-24.1), while Cr(III) ranged between 202.4 and 335.8 mg kg(-1) (±11.4-18.3). These results were very close to the results obtained by the CD method. PMID:24148433

  14. Spectrometric techniques 2

    CERN Document Server

    Vanasse, George A

    2013-01-01

    Spectrometric Techniques, Volume II provides information pertinent to vacuum ultraviolet techniques to complete the demonstration of the diversity of methods available to the spectroscopist interested in the ultraviolet visible and infrared spectral regions. This book discusses the specific aspects of the technique of Fourier transform spectroscopy.Organized into five chapters, this volume begins with an overview of the large number of systematic effects in the recording of an interferogram. This text then examines the design approach for a Fourier transform spectrometer with focus on optics.

  15. Photolytic-interference-free, femtosecond, two-photon laser-induced fluorescence imaging of atomic oxygen in flames

    Science.gov (United States)

    Kulatilaka, Waruna D.; Roy, Sukesh; Jiang, Naibo; Gord, James R.

    2016-02-01

    Ultrashort-pulse lasers are well suited for nonlinear diagnostic techniques such as two-photon laser-induced fluorescence (TPLIF) because the signals generated scale as the laser intensity squared. Furthermore, the broad spectral bandwidths associated with nearly Fourier-transform-limited ultrashort pulses effectively contribute to efficient nonlinear excitation by coupling through a large number of in-phase photon pairs, thereby producing strong fluorescence signals. Additionally, femtosecond (fs)-duration amplified laser systems typically operate at 1-10 kHz repetition rates, enabling high-repetition-rate imaging in dynamic environments. In previous experiments, we have demonstrated utilization of fs pulses for kilohertz (kHz)-rate, interference-free imaging of atomic hydrogen (H) in flames. In the present study, we investigate the utilization of fs-duration pulses to photolytic-interference-free TPLIF imaging of atomic oxygen (O). In TPLIF of O, photodissociation of vibrationally excited carbon dioxide (CO2) is known to be the prominent interference that produces additional O atoms in the medium. We have found that through the use of fs excitation, such interferences can be virtually eliminated in premixed laminar methane flames, which paves the way for two-dimensional imaging of O at kHz data rates. Such measurements can provide critical data for validating complex, multidimensional turbulent-combustion models as well as for investigating flame dynamics in practical combustion devices.

  16. 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).

  17. 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,…

  18. Direct visualization of triplex DNA molecular dynamics by fluorescence resonance energy transfer and atomic force microscopy measurements

    Science.gov (United States)

    Chang, Chia-Ching; Lin, Po-Yen; Chen, Yen-Fu; Chang, Chia-Seng; Kan, Lou-Sing

    2007-11-01

    We have detected the dynamics of 17-mer DNA triplex dissociation mechanism at the molecular level. Fluorescence resonance energy transfer (FRET) was used as an indicator of intermolecular interaction in nanometer range, whereas atomic force microscopy (AFM) was employed to address single molecule with sub-angstrom precision. The maximum rupture force of DNA triplex was found at pH 4.65, consistent with macroscopic observations. These results indicated that the FRET together with an AFM detection system could be used to reveal the DNA triplex interaction in nanometer scale unambiguously.

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

    International Nuclear Information System (INIS)

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

  20. Impact of the Pixel Pitch of the Timepix Chip Integrated to the GAMPIX Gamma Camera for Spectrometric and Imaging Performances

    International Nuclear Information System (INIS)

    Spatial localization and identification of radioactive sources is a main issue interesting Homeland Security. Gamma imaging allows reaching this need. A new gamma camera, GAMPIX, has been designed by the French Atomic Energy Commission (CEA). GAMPIX enables spatial localization of hot spots on a large energy range. Sensitivity, portability (2 kg) and ergonomics were improved in comparison with previous industrial systems. The detection system is based on the 1.4 cm side Timepix pixelated readout chip developed by CERN and hybridized to a 1 mm thick CdTe substrate. Pixel size of the Timepix chip is 55 μm or 110 μm. Ongoing developments concern the addition of a spectrometric capability to the existing system. The challenge is the optimization of spectrometric performances while maintaining imaging performances. Our work intends to assess the impact of pixel pitch by means of simulations and experimental validation. A large range of pixel pitch and energies were tested by MCNPX simulations. Fluorescence impact depending on pixel pitch was demonstrated. Pixel pitch impact on imaging performances was also studied. The purpose is to preserve the angular resolution of the GAMPIX gamma camera, i.e., the ability to separate radioactive sources spatially close. Energy calibration of Timepix detectors is crucial for the optimization of spectrometric performances. The small pixel size compared to the substrate thickness induces charge depositions in several pixels, called clusters, and the shift between spectra due to different cluster sizes degrades the energy resolution. The energy calibration of our Timepix detectors was carried out in the SOLEX tunable monochromatic X-ray source (CEA). Our developments show that the replacement of the 55 μm pixelated Timepix chip currently used in the GAMPIX gamma camera by a 110 μm pixel pitch would lead to a significant improvement in terms of spectrometric performances without degrading imaging abilities. (author)

  1. Oxygen-atom concentrations measured in flames: a method to improve the accuracy of laser-induced fluorescence diagnostics.

    Science.gov (United States)

    Myhr, F H; Driscoll, J F

    2001-10-20

    A procedure is proposed, denoted as the corrected laser-induced fluorescence (LIF) method, that reduces the error associated with the unavoidable photodissociation of O(2) molecules that has limited the measurement of oxygen-atom concentrations in the past. Two different laser intensities are employed, and the two signals that are obtained with two-photon LIF diagnostics are used to correct for the photolysis error. We measured oxygen-atom concentrations using this method at 33 locations in lean and rich flames. Results are compared with values determined by use of two independent techniques: the partial equilibrium method and equilibrium calculations. The measurements also quantify the shot noise, the photolysis errors, and the critical laser intensity required to avoid photolysis errors. PMID:18364818

  2. Analysis of Local Structures around Ni Atoms Doped in ZnO-Based Diluted Magnetic Semiconductors by Fluorescence EXAFS

    Institute of Scientific and Technical Information of China (English)

    LI Bin-Bin; XIU Xiang-Qian; ZHANG Rong; TAO Zhi-Kuo; CHEN Lin; XIE Zi-Li; ZHENG You-Dou; HE Bo

    2006-01-01

    @@ Zn1-xNixO (x = 0.001, 0.01, 0.02, 0.05 and 0.20) powders are prepared by sol-gel method. An extended x-ray absorption fine structure technique (EXAFS) for the Ni K-edge is employed to probe the local structures around Ni atoms doped in ZnO powders by fluorescence mode. The near edge EXAFS of the samples does not change in the range of Ni concentration from x = 0.001 to 0.05, which is consistent with the results of x-ray diffraction of the samples. The simulation results for the first shell EXAFS signals indicated that Ni atoms are substituted in Zn sites.

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

    Science.gov (United States)

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

    2007-10-01

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

  4. Automated sequential injection-microcolumn approach with on-line flame atomic absorption spectrometric detection for implementing metal fractionation schemes of homogeneous and non-homogeneous solid samples of environmental interest

    DEFF Research Database (Denmark)

    Chomchoei, Roongrat; Miró, Manuel; Hansen, Elo Harald;

    2005-01-01

    spectrometric detection and used for the determination of Cu as a model analyte, the potentials of this novel hyphenated approach are demonstrated by the ability of handling up to 300 mg sample of a nonhomogeneous sewage amended soil (viz., CRM 483). The three steps of the endorsed Standards, Measurements, and...

  5. Enhancement reagents for simultaneous vapor generation of zinc and cadmium with intermittent flow system coupled to atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Simultaneous vapor generation of zinc (Zn) and cadmium (Cd) was evaluated by atomic fluorescence spectrometry coupled with an intermittent flow vapor generation system. Some complexing reagents, surfactant and transition metal ions were respectively tested as enhancement reagents. Experiments showed that an appropriate amount of 8-hydroxyquinoline or phenanthroline and nickel ion simultaneously, effectively improved the vapor generation efficiency of Zn and Cd. The volatile species generation was presumed to be a hydrogenation process interpreting how the enhancement reagents played an important role in vapor generation. Additionally, due to the instability of volatile species, reaction temperature, rapid and sufficient mixing of reagents and rapid separation of the volatile species from liquid phase were also crucial. The method of simultaneous determination of Zn and Cd by intermittent flow vapor generation led to the development of atomic fluorescence spectrometry. The detection limits (3σb) were 1.6 μg l-1 for Zn and 0.01 μg l-1 for Cd and the relative standard deviations were 3.6% for Zn (50 μg l-1, n=11) and 1.7% for Cd (2 μg l-1, n=11) respectively. Results for the determination of Zn and Cd have been confirmed by the analysis of CRMs with good agreement between the certified and found values

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

    Science.gov (United States)

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

    2014-01-01

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

  7. Atoms

    Institute of Scientific and Technical Information of China (English)

    刘洪毓

    2007-01-01

    Atoms(原子)are all around us.They are something like the bricks (砖块)of which everything is made. The size of an atom is very,very small.In just one grain of salt are held millions of atoms. Atoms are very important.The way one object acts depends on what

  8. Development of the spectrometric imaging apparatus of laser induced fluorescence from plants and estimation of chlorophyll contents of rice leaves; Laser reiki keiko sokutei sochi no kaihatsu to inehanai no chlorophyll ganryo no suitei

    Energy Technology Data Exchange (ETDEWEB)

    Nakaya, K.; Shoji, K.; Hanyu, H.

    1999-05-01

    Photosynthetic activity of plants is an important factor to assess the micrometeorological effect of plant canopy or to estimate the influence of circumstances such as water stress. Light illumination induces fluorescence from a leaf or suspension of chloroplasts. The red chlorophyll fluorescence had been used to determine the process of the electron transportation in photosynthetic reaction. The fluorescence source other than chlorophyll is not announced sufficiently, but is supposed to be useful to determine the contents of the substance corresponding to physiological response of plants. We developed a fluorescence imaging apparatus to observe spectrum and distribution of laser induced fluorescence from a leaf. Pulsed UV-laser (Nd:YAG) induced blue-green fluorescence and red chlorophyll fluorescence from a green leaf. The pulse modulated measuring light and CCD with image-intensifier (ICCD) enable to detect the fluorescence from plants under illumination. The laser induced fluorescence (LIF) spectra were investigated to estimate the chlorophyll contents in leaves of rice. During the greening course of dark grown etiolated rice leaves, chlorophyll contents were determined using the extraction of leaves and steady state LIF spectra were measured. As a result, the ratio of fluorescent intensity between blue-green and red peaks (F460/F740 and F510/F740) decreased in proportion to alteration of chlorophyll contents respectively. These fluorescence intensity ratios perform more precise estimation of higher chlorophyll contents of leaves than reported red chlorophyll fluorescence intensity ratio (F690/E740). (author)

  9. Fluorescence excitation spectra of jet-cooled complexes of carbazole and mono-atomic alcohols

    International Nuclear Information System (INIS)

    Fluorescence excitation spectra of jet-cooled complexes of carbazole and one molecule of methyl, deuterated methyl, ethyl and propyl (propanol-1 and propanol-2) alcohols are analyzed. Shifts of the fluorescence excitation spectra of complexes relative to the frequency of a pure electron transition of unbound carbazole are determined. They are formed owing to the hydrogen bonds of the N-H groups of carbazole with the OH-group of alcohols. The frequencies of stretching vibrations of hydrogen groups with various alcohols vary within the range 150-157 cm-1, whereas for the deformation ones the frequencies fall in the interval 21-22.9 cm-1. The belonging of complexes to rotational conformers is determined through the shape of the rotational contours of bands of their pure electronic and electron-vibration transitions. Equilibrium configurations of complexes in the ground state are calculated (authors)

  10. Imaging magnetic scalar potentials by laser-induced fluorescence from bright and dark atoms

    Science.gov (United States)

    Fescenko, I.; Weis, A.

    2014-06-01

    We present a spectroscopic method for mapping two-dimensional distributions of magnetic field strengths (magnetic scalar potential lines) using charge-coupled device (CCD) recordings of the fluorescence patterns emitted by spin-polarized Cs vapour in a buffer gas exposed to inhomogeneous magnetic fields. The method relies on the position-selective destruction of spin polarization by magnetic resonances induced by multi-component oscillating magnetic fields, such that magnetic potential lines can be directly detected by the CCD camera. We also present a generic algebraic model allowing for the calculation of the fluorescence patterns and find excellent agreement with the experimental observations for three distinct inhomogeneous field topologies. The spatial resolution obtained with these proof-of-principle experiments is of the order of 1 mm. A substantial increase of spatial and magnetic field resolution is expected by deploying the method in a magnetically shielded environment.

  11. Imaging magnetic scalar potentials by laser-induced fluorescence from bright and dark atoms

    CERN Document Server

    Fescenko, Ilja

    2014-01-01

    We present a spectroscopic method for mapping two-dimensional distributions of magnetic field strengths (magnetic scalar potential lines) using CCD recordings of the fluorescence patterns emitted by spin-polarized Cs vapor in a buffer gas exposed to inhomogeneous magnetic fields. The method relies on the position-selective destruction of spin polarization by magnetic resonances induced by multi-component oscillating magnetic fields, such that magnetic potential lines can directly be detected by the CCD camera. We also present a generic algebraic model allowing the calculation of the fluorescence patterns and find excellent agreement with the experimental observations for three distinct inhomogeneous field topologies. The spatial resolution obtained with these proof-of-principle experiments is on the order of 1 mm. A substantial increase of spatial and magnetic field resolution is expected by deploying the method in a magnetically shielded environment.

  12. Imaging magnetic scalar potentials by laser-induced fluorescence from bright and dark atoms

    OpenAIRE

    Fescenko, Ilja; Weis, Antoine

    2014-01-01

    We present a spectroscopic method for mapping two-dimensional distributions of magnetic field strengths (magnetic scalar potential lines) using charge-coupled device (CCD) recordings of the fluorescence patterns emitted by spin-polarized Cs vapour in a buffer gas exposed to inhomogeneous magnetic fields. The method relies on the position-selective destruction of spin polarization by magnetic resonances induced by multi-component oscillating magnetic fields, such that magnetic potential lines ...

  13. Atoms

    International Nuclear Information System (INIS)

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

  14. Determination of Selenium in Marine Aquatic Products by Hydride Generation-atomic Fluorescence Spectrometry (HG-AFS)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhaohui; GAO Xin; Tashiro Yuri; Hiroo Ogawa

    2005-01-01

    A method for the analysis of selenium in marine aquatic products by HG-AFS has been investigated. The method is based on the reduction of inorganic selenium to volatile SeH2 which is bubbled out by carrier gas of pure argon, and then swept to Ar-H2 flame quarts atomizer to measure its fluorescence intensity. The hydride generation, transportation, atomization and some instrumental parameters were studied by a kind of orthogonal design. The optimum conditions selected are as follows: reactive acidity, 20% HC1; the amount of NaBH4, 4.9mL; gas flow of argon, 600mLmin-1; atomizing temperature, 200 ℃; negative high voltage, -300V; light current, 100 mA; integral time, 7s. The detection limit of the presented method is 0.072μgL-1 for selenium. The calibration curve shows a satisfactory line inthe concentration range from 0.000 to1.000μgL-1 Se. The recovery is 95.8%-102.2%.

  15. Determination of air Stannum in Workplace by L-cysteine and Atomic Fluorescence Spectrometry%工作场所空气中锡的L-半胱氨酸-原子荧光测定法

    Institute of Scientific and Technical Information of China (English)

    牛晓梅

    2011-01-01

    [Objective]To determine the air stannum in workplaces by hydride generation-atomic fluorescence spectrometry, with the existence of L-cysteine. [ Methods ] After digested by hydrochloric acid, the samples were determined by atomic fluorescence spectrometer with 2% hydrochloric acid as carrier liquid. [ Results] The range of measurement was 5. 0 ~ 200.0 μg/L, the RSD was 2.15% ~ 3.40%, the recoveries ranged from 92. 5% ~ 103.5% ,and the detection limits of this method was 0. 71 μg/L [ Conclusion] Due to the presence of L-cysteine, the hydride generation conditions are improved, the spectrometric signal is enhanced, and the acidity of solution is reduced. In addition, the interferences of the metal elements are significantly inhibited. The method is suitable for determination of air stannum in workplace.%目的 利用氢化物发生-原子荧光光谱法,在L-半胱氨酸存在的情况下,测定工作场所空气中的锡.方法 样品经盐酸消解,用2%盐酸溶液做载流,原子荧光分光光度计进行测定.结果 方法的测定范围为5.0~200.0 μg/L,相对标准偏差为2.15%~3.40%,回收率为92.5%~103.5%,检出限为0.71 μg/L.结论 由于L-半胱氨酸的存在,改善了氢化物发生条件,增敏光谱测定信号,降低了溶液的酸度,金属离子的干扰显著地得到了抑制,适用于工作场所空气中锡的测定.

  16. L-半胱氨酸-原子荧光法测定食品中的硒%Determination of selenium in food by L-Cysteine atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    牛晓梅

    2011-01-01

    目的:利用氢化物发生-原子荧光光谱法,在L-半胱氨酸存在下,测定食品中的硒.方法:样品经酸加热消化后,用2%盐酸溶液做载流,原子荧光分光光度计进行测定.结果:方法的测定范围为10.0μg/L~50.0μg/L,相对标准偏差为0.70%~1.90%,回收率为93.0%~101.0%,检出限为0.051μg/L.结论:由于L-半胱氨酸的存在,改善了氢化物发生条件,增敏光谱测定信号,降低了溶液的酸度,金属离子的干扰显著地得到了抑制,适用于食品中硒的测定.%Objective: In this paper, we give a method for determination of selenium in food by hydride generation -atomic fluorescence spectrometry in the presence of L- Cysteine.Methods: Using 2% hydrochloric acid as carrier liquid, the samples were determined by atomic fluorescence spectrometry after been digested by heating in acid.Results: The measurement range of this method was 10.0 μg/L ~ 50.0 μg/L, the RSD 0.7 % ~ 1.9%, the recoveries were in the range of 93.0% ~ 101.0% and the detection limits of this method were found to be 0.051 μg/L.Conclusion: In the presence of L - Cysteine, the hydride generation conditions were improved, the spectrometric signal was enhanced, and the acidity of solution was reduced.In addition, the interferences of the metal elements were significantly inhibited.The method can be used to determine seleium in food.

  17. 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.

  18. Electric field strength measurements in a megavolt vacuum diode using laser induced fluorescence of an atomic beam

    International Nuclear Information System (INIS)

    A combined technique of an atomic beam probing and laser-induced fluorescence spectroscopy (LIFABS) is applied for measuring of local electric field in a 1 MV, 100 kJ, 4 μsec electron diode. Laser-produced lithium beam is stepwise excited by two resonant wide-band laser beams. Stark-splitted spontaneous emission from n=4 level is detected with a polychromator. Time dependence of the electric field was inferred from splitting of the 460.3 nm lithium line. The electric field strength F grows during a pulse from 160 to 260 kV/cm in the center of a 6 cm gap. By comparing calculated and experimental F-values, expansion of the emission boundaries of the cathode and anode plasmas was reconstructed

  19. Determination of mercury by electrochemical cold vapor generation atomic fluorescence spectrometry using polyaniline modified graphite electrode as 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.c [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China); Wan Lingzhong; Zhang Hanchang; He Youzhao [Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2010-02-15

    An electrochemical cold vapor generation system with polyaniline modified graphite electrode as cathode material was developed for Hg (II) determination by coupling with atomic fluorescence spectrometry. This electrochemical cold vapor generation system with polyaniline/graphite electrode exhibited higher sensitivity; excellent stability and lower memory effect compared with graphite electrode electrochemical cold vapor generation system. The relative standard deviation was 2.7% for eleven consecutive measurements of 2 ng mL{sup -1} Hg (II) standard solution and the mercury limit of detection for the sample blank solution was 1.3 rg mL{sup -1} (3sigma). The accuracy of the method was evaluated through analysis of the reference materials (GBW09101) (Human hair) and GBW (08517) (Laminaria Japonica Aresch) and the proposed method was successfully applied to the analysis of human hairs.

  20. Coupling laser ablation and atomic fluorescence spectrophotometry: an example using mercury analysis of small sections of fish scales.

    Science.gov (United States)

    Beaudin, Luc; Johannessen, Sophia C; Macdonald, Robie W

    2010-11-01

    Mercury is a toxic element that exchanges among air, water, and sediments and biomagnifies into high trophic level organisms. Here, we present a novel combination of laser ablation with relatively low-cost cold vapor atomic fluorescence spectrophotometry to analyze Hg vaporized from targeted patches of fish scale 300-500 μm square. This method permits the analysis of multiple samples from the same scale, which is useful, because fish scale growth rings may provide an archive from which spatial and temporal trends in environmental Hg can be inferred at fine resolution. The detection limit of the method is 1.5 pg Hg, with a precision of 0.1 pg/μL. Developed using fish scales, the method could be adapted to other media, such as baleen, shells, nails, hair, teeth, wood and, possibly, varved sediments. PMID:20942426

  1. Surface passivation of nano-textured fluorescent SiC by atomic layer deposited TiO2

    Science.gov (United States)

    Lu, Weifang; Ou, Yiyu; Jokubavicius, Valdas; Fadil, Ahmed; Syväjärvi, Mikael; Petersen, Paul Michael; Ou, Haiyan

    2016-07-01

    Nano-textured surfaces have played a key role in optoelectronic materials to enhance the light extraction efficiency. In this work, morphology and optical properties of nano-textured SiC covered with atomic layer deposited (ALD) TiO2 were investigated. In order to obtain a high quality surface for TiO2 deposition, a three-step cleaning procedure was introduced after RIE etching. The morphology of anatase TiO2 indicates that the nano-textured substrate has a much higher surface nucleated grain density than a flat substrate at the beginning of the deposition process. The corresponding reflectance increases with TiO2 thickness due to increased surface diffuse reflection. The passivation effect of ALD TiO2 thin film on the nano-textured fluorescent 6H-SiC sample was also investigated and a PL intensity improvement of 8.05% was obtained due to the surface passivation.

  2. Fluorescence spectroscopy in the nanosecond range for matrix-isolated Cu atoms and dimers

    Science.gov (United States)

    Wiggenhauser, H.; Kolb, D. M.; Rotermund, H. H.; Schrittenlacher, W.; Schroeder, W.

    1985-11-01

    Synchrotron radiation in the single-bunch mode was employed to study time-resolved emission from Cu atoms and dimers isolated in a Ne matrix. The decay time of the matrix-related emission at 3.5 eV for Cu in Ne after excitation of the 4s → 4p resonance transition was determined as 6.9±0.3 ns, while excitation into higher-lying 3d → 4p transitions resulted in a much slower decay of the 3.5 eV emission. From analysis of rise and decay times, a detailed diagram for energy dissipation in matrix-isolated Cu atoms has been derived. The B → X (Σ u → Σ g) emission of Cu 2 in Ne has a first-order decay time of about 10 ns.

  3. Imaging of the expansion of femtosecond-laser-produced silicon plasma atoms by off-resonant planar laser-induced fluorescence

    International Nuclear Information System (INIS)

    Planar laser-induced fluorescence measurements were used to investigate the expansion dynamics of a femtosecond laser-induced plasma. Temporally and spatially resolved measurements were performed to monitor the atoms that were ablated from a silicon target. A dye laser (λ = 288.16 nm) was used to excite fluorescence signals. The radiation of an off-resonant transition (Si 390.55 nm) was observed at different distances from the target surface. This allowed easy detection of the ablated Si atoms without problems caused by scattered laser light. Abel inversion was applied to obtain the radial distribution of the Si atoms. The atom distribution in the plasma shows some peculiarities, depending on the crater depth

  4. Two-Photon Laser-Induced Fluorescence O and N Atoms for the Study of Heterogeneous Catalysis in a Diffusion Reactor

    Science.gov (United States)

    Pallix, Joan B.; Copeland, Richard A.; Arnold, James O. (Technical Monitor)

    1995-01-01

    Advanced laser-based diagnostics have been developed to examine catalytic effects and atom/surface interactions on thermal protection materials. This study establishes the feasibility of using laser-induced fluorescence for detection of O and N atom loss in a diffusion tube to measure surface catalytic activity. The experimental apparatus is versatile in that it allows fluorescence detection to be used for measuring species selective recombination coefficients as well as diffusion tube and microwave discharge diagnostics. Many of the potential sources of error in measuring atom recombination coefficients by this method have been identified and taken into account. These include scattered light, detector saturation, sample surface cleanliness, reactor design, gas pressure and composition, and selectivity of the laser probe. Recombination coefficients and their associated errors are reported for N and O atoms on a quartz surface at room temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-01-01

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

  6. A new way towards high-efficiency thermally activated delayed fluorescence devices via external heavy-atom effect

    Science.gov (United States)

    Zhang, Wenzhi; Jin, Jiangjiang; Huang, Zhi; Zhuang, Shaoqing; Wang, Lei

    2016-07-01

    Thermally activated delayed fluorescence (TADF) mechanism is a significant method that enables the harvesting of both triplet and singlet excitons for emission. However, up to now most efforts have been devoted to dealing with the relation between singlet-triplet splitting (ΔEST) and fluorescence efficiency, while the significance of spin-orbit coupling (SOC) is usually ignored. In this contribution, a new method is developed to realize high-efficiency TADF-based devices through simple device-structure optimizations. By inserting an ultrathin external heavy-atom (EHA) perturber layer in a desired manner, it provides useful means of accelerating the T1 → S1 reverse intersystem crossing (RISC) in TADF molecules without affecting the corresponding S1 → T1 process heavily. Furthermore, this strategy also promotes the utilization of host triplets through Förster mechanism during host → guest energy transfer (ET) processes, which helps to get rid of the solely dependence upon Dexter mechanism. Based on this strategy, we have successfully raised the external quantum efficiency (EQE) in 4CzPN-based devices by nearly 38% in comparison to control devices. These findings provide keen insights into the role of EHA played in TADF-based devices, offering valuable guidelines for utilizing certain TADF dyes which possess high radiative transition rate but relatively inefficient RISC.

  7. High-Sensitivity In situ Fluorescence Imaging of Ytterbium Atoms in a Two-Dimensional Optical Lattice with Dual Optical Molasses

    Science.gov (United States)

    Shibata, Kosuke; Yamamoto, Ryuta; Takahashi, Yoshiro

    2014-01-01

    We developed a dual molasses technique which enabled us to perform high-sensitivity in situ fluorescence imaging of ytterbium (Yb) atoms in a two-dimensional optical lattice prepared in a thin glass cell. This technique successfully combines two different kinds of optical molasses for Yb atoms, that is, the one using the 1S0-1P1 transition which provides high-resolution in the in situ fluorescence imaging and the other using the 1S0-3P1 transition for cooling the atoms in the optical lattice. We performed in situ imaging of 174Yb atoms and could observe a Moiré pattern with a period of about 6 µm produced by the molasses beam with 556 nm and the optical lattice with 532 nm, which implies that the temperature was kept below the lattice depth during the fluorescence imaging. The number of photons per atom is estimated to be enough for single atom detection with our imaging system. This result is quite promising for the realization of an Yb quantum gas microscope.

  8. Determination of Mercury in Aqueous and Geologic Materials by Continuous Flow-Cold Vapor-Atomic Fluorescence Spectrometry (CVAFS)

    Science.gov (United States)

    Hageman, Philip L.

    2007-01-01

    New methods for the determination of total mercury in geologic materials and dissolved mercury in aqueous samples have been developed that will replace the methods currently (2006) in use. The new methods eliminate the use of sodium dichromate (Na2Cr2O7 ?2H2O) as an oxidizer and preservative and significantly lower the detection limit for geologic and aqueous samples. The new methods also update instrumentation from the traditional use of cold vapor-atomic absorption spectrometry to cold vapor-atomic fluorescence spectrometry. At the same time, the new digestion procedures for geologic materials use the same size test tubes, and the same aluminum heating block and hot plate as required by the current methods. New procedures for collecting and processing of aqueous samples use the same procedures that are currently (2006) in use except that the samples are now preserved with concentrated hydrochloric acid/bromine monochloride instead of sodium dichromate/nitric acid. Both the 'old' and new methods have the same analyst productivity rates. These similarities should permit easy migration to the new methods. Analysis of geologic and aqueous reference standards using the new methods show that these procedures provide mercury recoveries that are as good as or better than the previously used methods.

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

    Science.gov (United States)

    Zu, Wenchuan; Wang, Zhenghao

    2016-03-01

    A homemade electrochemical flow cell was adopted for the determination of methylmercury. The cold vapor of mercury atoms was generated from the surface of glassycarbon cathode through the method of electrolytic reduction and detected by atomic fluorescence spectroscopy subsequently. The operating conditions were optimized with 2 ng mL(-1) methylmercury standard solution. The caliberation curve was favorably linear when the concentrations of standard HgCH3(+) solutions were in the range of 0.2-5 ng mL(-1)(as Hg). Under the optimized conditions, the limit of detection (LOD) for methylmercury was 1.88×10(-3)ng mL(-1) and the precision evaluated by relative standard deviation was 2.0% for six times 2 ng mL(-1) standard solution replicates. The terminal analytical results of seafood samples, available from local market, showed that the methylmercury content ranged within 3.7-45.8 ng g(-1). The recoveries for methylmercury spiked samples were found to be in the range of 87.6-103.6% and the relative standard deviations below 5% (n=6) were acquired, which showed this method was feasible for real sample analysis. PMID:26615576

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

    Energy Technology Data Exchange (ETDEWEB)

    Teramoto, Yoshiyuki; Ono, Ryo [Department of Advanced Energy, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 227-8568 (Japan); Oda, Tetsuji [Department of Electrical Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

    2012-06-01

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

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

    International Nuclear Information System (INIS)

    To study the production mechanism of atomic nitrogen, the temporal profile and spatial distribution of atomic nitrogen are measured in atmospheric pressure pulsed positive corona discharge using two-photon absorption laser-induced fluorescence. The absolute atomic nitrogen density in the streamer filaments is estimated from decay rate of atomic nitrogen in N2 discharge. The results indicate that the absolute atomic nitrogen density is approximately constant against discharge energy. When the discharge voltage is 21.5 kV, production yield of atomic nitrogen produced by an N2 discharge pulse is estimated to be 2.9 - 9.8 × 1013 atoms and the energy efficiency of atomic nitrogen production is estimated to be about 1.8 - 6.1 × 1016 atoms/J. The energy efficiency of atomic nitrogen production in N2 discharge is constant against the discharge energy, while that in N2/O2 discharge increases with discharge energy. In the N2/O2 discharge, two-step process of N2 dissociation plays significant role for atomic nitrogen production.

  12. Rocket observation of atomic oxygen and night airglow: Measurement of concentration with an improved resonance fluorescence technique

    Directory of Open Access Journals (Sweden)

    K. Kita

    Full Text Available An improved resonant fluorescence instrument for measuring atomic oxygen concentration was developed to avoid the Doppler effect and the aerodynamic shock effect due to the supersonic motion of a rocket. The shock effect is reduced by adopting a sharp wedge-shaped housing and by scanning of the detector field of view to change the distance between the scattering volume and the surface of the housing. The scanning enables us to determine absolute values of atomic oxygen concentration from relative variation of the scattered light signal due to the self-absorption. The instrument was calibrated in the laboratory, and the numerical simulation reproduced the calibration result. Using the instrument, the altitude profile of atomic oxygen concentration was observed by a rocket experiment at Uchinoura (31°N on 28 January 1992. The data obtained from the rocket experiment were not perfectly free from the shock effect, but errors due to the effect were reduced by the data analysis procedure. The observed maximum concentration was 3.8× 1011 cm–3 at altitudes around 94 km. The systematic error is estimated to be less than ±0.7×1011 cm–3 and the relative random error is less than±0.07× 1011 cm–3at the same altitudes. The altitude profile of the OI 557.7-nm airglow was also observed in the same rocket experiment. The maximum volume emission rate was found to be 150 photons cm–3 s–1 at 94 km. The observed altitude profiles are compared with the MSIS model and other in situ observations.

  13. Measurement of total angular momentum values of high-lying even-parity atomic states of samarium by spectrally resolved laser-induced fluorescence technique

    Indian Academy of Sciences (India)

    A K Pulhani; M L Shah; G P Gupta; B M Suri

    2010-12-01

    Spectrally resolved laser-induced fluorescence technique was used to uniquely assign total angular momentum () values to high-lying even-parity energy levels of atomic samarium. Unique value assignment was done for seven energy levels in the energy region 34,800–36,200 cm-1 , recently observed and reported in the literature.

  14. Empirical and semi-empirical interpolation of L X-ray fluorescence parameters for elements in the atomic range 50≤Z≤92

    International Nuclear Information System (INIS)

    In this study, interpolations (empirical and semi-empirical) of L sub-shell fluorescence yield and L shell Coster–Kronig transition probability values and the measured L X-ray production cross-sections, intensity ratios and L sub-shell fluorescence yield values of elements have been performed in the range of 50≤Z≤92. In this experimental setup, two sources (50 mCi 55Fe and 50 mCi 241Am) were used. L X-rays emitted by samples were counted by an Ultra-LEGe detector with a resolution of 150 eV at 5.9 keV. - Highlights: • This work was performed for the elements having the atomic numbers between 50 and 92. • Experimental L-shell fluorescence parameters were investigated. • New fit values of L subshell fluorescence and Coster–Kronig yield were presented

  15. Mass Spectrometric Analysis of Water-soluble Gold Nanoclusters

    International Nuclear Information System (INIS)

    Batches of water-soluble gold nanoclusters of nominal 2.0 or 3.5-nm diameter were prepared to evaluate particle size determinations by a number of techniques such as transmission electron microscopy or atomic force microscopy and to validate estimates derived by mass spectrometric analysis using matrix-assisted laser desorption ionization (MALDI). Good agreement was found and MALDI lends itself to analyses even in the presence of aggregates

  16. Two-photon absorption laser-induced fluorescence measurements of atomic nitrogen in a radio-frequency atmospheric-pressure plasma jet

    International Nuclear Information System (INIS)

    The first direct measurements of atomic nitrogen species in a radio-frequency atmospheric-pressure plasma jet (APPJ) are presented. Atomic nitrogen radicals play a key role in new plasma medicine applications of APPJs. The measurements were performed with a two-photon absorption laser-induced fluorescence diagnostic, using 206.65 nm laser photons for the excitation of ground-state N atoms and observing fluorescence light around 744 nm. The APPJ was run with a helium gas flow of 1 slm and varying small admixtures of molecular nitrogen of 0–0.7 vol%. A maximum in the measured N concentration was observed for an admixture of 0.25 vol% N2. (fast track communication)

  17. 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%.

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

    Science.gov (United States)

    Zhou, Qingxiang; Zhao, Na; Xie, Guohong

    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(-1) (r(2) = 0.9990). The precision was 2.12% (RSD, n = 7) and the detection limit was 0.95 ng L(-1). Proposed method was validated with four real environmental samples and the results indicated that the proposed method was excellent for the future use and satisfied spiked recoveries were in the range of 92.9-97.4%. PMID:21398026

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

    International Nuclear Information System (INIS)

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

  20. Determination of trace mercury in environmental samples by cold vapor atomic fluorescence spectrometry after cloud point extraction

    International Nuclear Information System (INIS)

    A sensitive method is presented for the determination of ultra-trace levels of mercury using cold vapor atomic fluorescence spectrometry along with cloud point extraction. Preconcentration is based on the complexation of Hg(II) by dithizone, followed by micelle-mediated extraction of the complex using the surfactant Triton X-114. Foaming, which is always observed when generating vapor mercury in the presence of surfactant, was strongly reduced by using SnCl2 as a reducing reagent, and a homemade gas-liquid separator. Variables that affect the assay were optimized. These included pH value, concentration of chelating reagent, concentration of Triton X-114, equilibration temperature and time. The preconcentration of a 45-mL sample gave an enhancement factor of 29. The calibration graph is linear in the range from 0. 05 to 5. 0 ng mL-1 with a correlation coefficient of 0. 9991. The limit of detection obtained under the optimal conditions is 5 pg mL-1. The relative standard deviation for seven replicate determinations at 0. 5 ng mL-1 level is 5. 2%. The method was successfully applied to the determination of Hg in real samples. (author)

  1. Relationship between cell stiffness and stress fiber amount, assessed by simultaneous atomic force microscopy and live-cell fluorescence imaging.

    Science.gov (United States)

    Gavara, Núria; Chadwick, Richard S

    2016-06-01

    Actomyosin stress fibers, one of the main components of the cell's cytoskeleton, provide mechanical stability to adherent cells by applying and transmitting tensile forces onto the extracellular matrix (ECM) at the sites of cell-ECM adhesion. While it is widely accepted that changes in spatial and temporal distribution of stress fibers affect the cell's mechanical properties, there is no quantitative knowledge on how stress fiber amount and organization directly modulate cell stiffness. We address this key open question by combining atomic force microscopy with simultaneous fluorescence imaging of living cells, and combine for the first time reliable quantitative parameters obtained from both techniques. We show that the amount of myosin and (to a lesser extent) actin assembled in stress fibers directly modulates cell stiffness in adherent mouse fibroblasts (NIH3T3). In addition, the spatial distribution of stress fibers has a second-order modulatory effect. In particular, the presence of either fibers located in the cell periphery, aligned fibers or thicker fibers gives rise to reinforced cell stiffness. Our results provide basic and significant information that will help design optimal protocols to regulate the mechanical properties of adherent cells via pharmacological interventions that alter stress fiber assembly or via micropatterning techniques that restrict stress fiber spatial organization. PMID:26206449

  2. 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. PMID:22970588

  3. UV-assisted Fenton digestion of rice for the determination of trace cadmium by hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Yu, Huimin; Ai, Xi; Xu, Kailai; Zheng, Chengbin; Hou, Xiandeng

    2016-02-21

    A new digestion method using UV-assisted Fe(0) Fenton reaction was developed for the determination of trace Cd in rice by hydride generation atomic fluorescence spectrometry. The proposed method integrated the advantages of simplicity, small dose of reagents, low cost and moderate reaction conditions, and was successfully utilized to analyze a Certified Reference Material (CRM) and real rice samples. A 1 mL mixture of the sample and reagents (0.0500 g rice powder, 0.2% (m/v) Fe(0), 0.75% (v/v) HNO3 and 18% (v/v) H2O2) was irradiated by UV-light for 50 min and then a clear solution was obtained by separating excess Fe(0) with a magnet prior to spectral analysis. The limit of detection (LOD) for Cd was found to be 0.02 mg kg(-1) and the relative standard deviation was better than 5.0% at a concentration level of 0.40 mg kg(-1). The recovery obtained by analyzing the CRM was 103% and spiked recoveries with 0.40 mg kg(-1) Cd in rice samples were 93% and 101%. The t-test proved that there is no significant difference between the certified value and the determined value of the CRM, and between the proposed method and microwave-assisted digestion coupled with inductively coupled plasma mass spectrometry (MWD-ICP-MS) at 95% confidence level. PMID:26759832

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

    Science.gov (United States)

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

    2002-01-01

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

  5. Multielement analysis of Pakistan coal by X-ray fluorescence spectrometry and inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Major, minor and trace element concentration levels are determined for 21 tertiary lignites and sub-bituminous coal samples collected from seven major coal field in Pakistan. Samples are collected as channel samples and/or run of mine samples. All samples are analysed by the x-ray fluorescence spectrometry (XRFS) technique whereas samples from Cherat coal field and the Katha-Pale coal field are analysed by the inductively coupled plasma atomic emission spectrometry (ICP-AES). Significant concentrations of toxic elements such as S, Ce, Cd, Cr, Cu, Mn, Ni, P, Pb, U and V are found in these coal samples. Thus, continuous exposure to dust of these coals (by the mine workers and inhabitants of the nearby settlements) and their extensive use of domestic purpose (cooking/heating), or in brick kilns and in combustion chambers of thermal power plants may cause significant environmental pollution problems as well as health problems. Their use in the industrial and energy sectors will further pose engineering/operational problems in items of requirements of preventive measures against corrosion of the combustion units. (author) 8 tabs

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

    Science.gov (United States)

    Matos Reyes, M. N.; Cervera, M. L.; Campos, R. C.; de la Guardia, M.

    2007-09-01

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

  7. Improvements and application of a modified gas chromatography atomic fluorescence spectroscopy method for routine determination of methylmercury in biota samples.

    Science.gov (United States)

    Gorecki, Jerzy; Díez, Sergi; Macherzynski, Mariusz; Kalisinska, Elżbieta; Golas, Janusz

    2013-10-15

    Improvements to the application of a combined solid-phase microextraction followed by gas chromatography coupled to pyrolysis and atomic fluorescence spectrometry method (SPME-GC-AFS) for methylmercury (MeHg) determination in biota samples are presented. Our new method includes improvements in the methodology of determination and the quantification technique. A shaker instead of a stirrer was used, in order to reduce the possibility of sample contamination and to simplify cleaning procedures. Then, optimal rotation frequency and shaking time were settled at 800 rpm and 10 min, respectively. Moreover, the GC-AFS system was equipped with a valve and an argon heater to eliminate the effect of the decrease in analytical signal caused by the moisture released from SPME fiber. For its determination, MeHg was first extracted from biota samples with a 25% KOH solution (3h) and then it was quantified by two methods, a conventional double standard addition method (AC) and a modified matrix-matched calibration (MQ) which is two times faster than the AC method. Both procedures were successfully tested with certified reference materials, and applied for the first time to the determination of MeHg in muscle samples of goosander (Mergus merganser) and liver samples of white-tailed eagle (Haliaeetus albicilla) with values ranging from 1.19 to 3.84 mg/kg dry weight (dw), and from 0.69 to 6.23 mg kg(-1) dw, respectively. PMID:24054647

  8. Reversed-phase liquid-chromatographic mass spectrometric N-glycan analysis of biopharmaceuticals

    OpenAIRE

    Higel, Fabian; Demelbauer, Uwe; Seidl, Andreas; Friess, Wolfgang; Sörgel, Fritz

    2013-01-01

    N-Glycosylation is a common post-translational modification of monoclonal antibodies with a potential effect on the efficacy and safety of the drugs; detailed knowledge about this glycosylation is therefore crucial. We have developed a reversed-phase liquid chromatographic–mass spectrometric method, with different fluorescent labels, for analysis of N-glycosylation, and compared the sensitivity and selectivity of the methods. Our work demonstrates that anthranilic acid as fluorescent label in...

  9. Single-Laboratory Validation of a High-Performance Liquid Chromatographic-Diode Array Detector-Fluorescence Detector/Mass Spectrometric Method for Simultaneous Determination of Water-Soluble Vitamins in Multivitamin Dietary Tablets

    OpenAIRE

    Chen, Pei; Atkinson, Renata; Wolf, Wayne R.

    2009-01-01

    The purpose of this study was to develop a single-laboratory validated (SLV) method using high-performance liquid chromatography with different detectors [diode array detector (DAD); fluorescence detector (FLD); and mass spectrometry (MS)] for determination of 7 B-complex vitamins (B1-thiamin, B2-riboflavin, B3-nicotinamide, B6-pyridoxine, B9-folic acid, pantothenic acid, and biotin) and vitamin C in multivitamin/multimineral dietary supplements. The method involves the use of a reversed-phas...

  10. 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.

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

    International Nuclear Information System (INIS)

    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

  12. 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.

  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. Development of a MSFIA system for sequential determination of antimony, arsenic and selenium using hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    de Santana, Fernanda A; Portugal, Lindomar A; Serra, Antonio M; Ferrer, Laura; Cerdà, Víctor; Ferreira, Sergio L C

    2016-08-15

    This paper proposed a multisyringe flow injection analysis (MSFIA) system for antimony, arsenic and selenium determination in peanut samples by hydride generation atomic fluorescence spectrometry (HG-AFS). The optimization step of the hydride generation was performed using a two-level full factorial design involving the parameters: hydrochloric acid, sodium tetrahydroborate and potassium iodide concentrations. So, using the chemical conditions optimized, this method allows the determination of these elements employing the external calibration technique using aqueous standards with limits of detection and quantification of 0.04 and 0.14µgL(-1) for antimony, 0.04 and 0.14µgL(-1) for arsenic and 0.14 and 0.37µgL(-1) for selenium, respectively. Additionally, the effect of vanadium, chromium, cobalt, nickel, zinc, copper, iron and molybdenum on the generation of chemical vapour was also studied. The precision expressed as relative standard deviation varied from 1.2 to 3.6% for antimony, 1.8-3.9% for arsenic and 1.8-2% for selenium. The accuracy for arsenic and selenium was confirmed using the certified peach leaves reference material SRM 1547 produced by National Institute of Standard and Technology. The proposed method showed 45 injection throughput (h(-1)) using 1.6mL sample volume for each element, 0.8mL NaBH4 0.5% (w/v) containing NaOH 0.05% (w/v), 0.8mL HCl 5M and 0.4mL KI 14% (w/v) containing L-ascorbic acid 2.5% (w/v). The method was applied to the determination of antimony, arsenic and selenium in peanut samples, which were firstly lyophilized and afterward digested using microwave assisted radiation. Six samples were analyzed and the contents of the elements found were: 28.7-41.3µgkg(-1) for arsenic, 86.4-480.1µgkg(-1) for selenium and 32.6-52.4µgkg(-1) for antimony. Addition/recovery tests were also performed to confirm the method accuracy for the three elements. PMID:27260431

  15. Measurement of radiative lifetime in atomic samarium using simultaneous detection of laser-induced fluorescence and photoionization signals

    Indian Academy of Sciences (India)

    A C Sahoo; M L Shah; P K Mandal; A K Pulhani; G P Gupta; Vas Dev; B M Suri

    2014-02-01

    In this paper, we report the investigations of lifetime measurement of odd-parity energy level 19009.52 cm-1 of Sm I using simultaneous detection of laser-induced fluorescence and laserinduced photoionization signals employing pump–probe technique. To the best of our knowledge, this is for the first time that the results obtained using laser-induced fluorescence and photoionization techniques have been compared with each other. The obtained results match well with those reported in the literature.

  16. Absolute nitrogen atom density measurements by two-photon laser-induced fluorescence spectroscopy in atmospheric pressure dielectric barrier discharges of pure nitrogen

    International Nuclear Information System (INIS)

    In this paper, two-photon absorption laser induced fluorescence spectroscopy is used to follow the nitrogen atom density in flowing dielectric barrier discharges fed with pure nitrogen and operating at atmospheric pressure. Two different dielectric barrier discharge regimes are investigated: the Townsend regime, which is homogeneous although operating at atmospheric pressure, and the more common filamentary regime. In both regimes, densities as high as 3x1014/cm3 are detected. However, the N atoms kinetic formation depends on the discharge regime. The saturation level is reached more rapidly with a filamentary discharge. For a given discharge regime, the N atom density depends strongly on the energy dissipated in the plasma between the gas inlet and the measurement position, whether the energy is varied by varying the position of the measurements, the gas flow, or the dissipated power. Experiments performed in the postdischarge show that the N atom decay cannot be simply attributed to three-body recombination of atomic nitrogen with nitrogen molecules, meaning that other mechanisms such as surface recombination or gas impurities play a role.

  17. Thermal ionization mass spectrometric study of U-Pu-O system

    International Nuclear Information System (INIS)

    First inference from a thermal ionization mass spectrometric study of samples corresponding to the ternary U-Pu-O system, especially if high surface ionization temperatures are employed, is likely to be at variance with that from equilibrium vaporization thermodynamic studies, that the atomic species U and Pu dominate the vapor phase

  18. Spectrometric methods for the determination of chlorine in crude oil and petroleum derivatives — A review

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Adriana [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, Gávea, Rio de Janeiro, RJ 22451-900 (Brazil); Saavedra, Alvaro; Tristão, Maria Luiza B.; Mendes, Luiz A.N. [Leopoldo Américo Miguez de Mello Research Center — Petrobras (CENPES), Cidade Universitária, Quadra 7, Ilha do Fundão, Rio de Janeiro 21949-900 (Brazil); Aucélio, Ricardo Q., E-mail: aucelior@puc-rio.br [Department of Chemistry, Pontifical Catholic University of Rio de Janeiro, Rua Marquês de São Vicente 225, Gávea, Rio de Janeiro, RJ 22451-900 (Brazil)

    2013-08-01

    Chlorine determination in crude oil is made in order to guarantee that the oil does not contain levels of this element that might cause damages in the oil processing equipment. In petroleum products, the determination of chlorine is made, for instance, to evaluate if there are proper concentrations of organochloride compounds, which are used as additives. Such determinations are currently performed following official guidelines from the ASTM International and from the United States Environmental Protection Agency as well as protocols indicated by the Universal Oil Products. X-ray fluorescence spectroscopy plays an important role in many of these official methods. In contrast, other spectrometric methods based on optical and mass detection are plagued by limitations related to both the fundamental characteristics of non-metals and to the complex sample matrices, which reflects in the small number of articles devoted to these applications. In this review, the current status of the spectrometric methods, especially the role played by X-ray fluorescence spectrometry, is evaluated in terms of the determination of chlorine in crude oil and petroleum derivatives. Comparison of the performance of the methods, limitations and potential new approaches to ensure proper spectrometric determinations of chlorine is indicated. - Highlights: • Critical evaluation of spectrometric methods for chlorine in petroleum products. • Reviews on element determination in petroleum have not address the case of chlorine. • Peculiarities of the spectrometric determination of Cl in petroleum are discussed. • The spectrometric approaches are detailed and compared to the official methods. • New trends in chlorine determination in petroleum products are indicated.

  19. Spectrometric methods for the determination of chlorine in crude oil and petroleum derivatives — A review

    International Nuclear Information System (INIS)

    Chlorine determination in crude oil is made in order to guarantee that the oil does not contain levels of this element that might cause damages in the oil processing equipment. In petroleum products, the determination of chlorine is made, for instance, to evaluate if there are proper concentrations of organochloride compounds, which are used as additives. Such determinations are currently performed following official guidelines from the ASTM International and from the United States Environmental Protection Agency as well as protocols indicated by the Universal Oil Products. X-ray fluorescence spectroscopy plays an important role in many of these official methods. In contrast, other spectrometric methods based on optical and mass detection are plagued by limitations related to both the fundamental characteristics of non-metals and to the complex sample matrices, which reflects in the small number of articles devoted to these applications. In this review, the current status of the spectrometric methods, especially the role played by X-ray fluorescence spectrometry, is evaluated in terms of the determination of chlorine in crude oil and petroleum derivatives. Comparison of the performance of the methods, limitations and potential new approaches to ensure proper spectrometric determinations of chlorine is indicated. - Highlights: • Critical evaluation of spectrometric methods for chlorine in petroleum products. • Reviews on element determination in petroleum have not address the case of chlorine. • Peculiarities of the spectrometric determination of Cl in petroleum are discussed. • The spectrometric approaches are detailed and compared to the official methods. • New trends in chlorine determination in petroleum products are indicated

  20. Mass spectrometric investigation of fluorated europium. beta. -diketonates. [Electrons

    Energy Technology Data Exchange (ETDEWEB)

    Khomenko, V.S.; Lozinskij, M.O.; Fialkov, Yu.A.; Rasshinina, T.A.; Suboch, V.P. (AN Belorusskoj SSR, Minsk. Inst. Fiziki; AN Ukrainskoj SSR, Kiev. Inst. Organicheskoj Khimii)

    Ternary complexes of europium with two organic ligands - fluorated ..beta..-diketone and organic base - in the aqueous phase at electron shock are investigated; regroupings that take place in them are established. Mass-spectrometric investigation has shown that complexes with ..beta..-diketones, containing in oxygen atom in a fluorated radical, eliminate stable molecules of difluorophosgen, CoF/sub 2/. For the complexes studied under the above conditions the Co molecule elimination is also typical which is accompanied by the formation of ions with a metal-carbon bond.

  1. Highly selective micro-sequential injection lab-on-valve (μSI-LOV) method for determination of ultra trace concentrations of nickel in saline matrices using detection by electrothermal atomic absorption spectrometr

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Jensen, Rikard;

    2006-01-01

    electrothermal atomic absorption spectrometry (ETAAS). Based on the dimethylglyoxime (DMG) gravimetric procedure used for nickel analysis, the sample, as contained in pH 9.0 buffer, is, after on-line merging with the chelating reagent, transported to a reaction coil attached to one of the external ports of the...

  2. Determination of trace metal ions via on-line separation and preconcentration by means of chelating Sepharose beads in a sequential injection lab-on-valve (SI-LOV) system coupled to electrothermal atomic absorption spectrometric detection

    DEFF Research Database (Denmark)

    Long, Xiangbao; Hansen, Elo Harald; Miró, Manuel

    2005-01-01

    The analytical performance of an on-line sequential injection lab-on-valve (SI-LOV) system using chelating Sepharose beads as sorbent material for the determination of ultra trace levels of Cd(II), Pb(II) and Ni(II) by electrothermal atomic absorption spectrometry (ETAAS) is described and discussed...

  3. Nanodimentional Aggregates In Organic Monolayers Studied With Atomic Force Microscopy (AFM) And Fluorescence Lifetime Imaging Microscopy (FLIM)

    Science.gov (United States)

    Ivanov, George R.; Burov, Julian

    2007-04-01

    Organic monolayers from a fluorescently labeled phospholipid (DPPE-NBD) were deposited on solid supports under special conditions that form stable nanometer wide bilayers cylinders that protrude from the monolayer. This molecule was frequently used in sensor applications due to its sensitivity to environment changes. The proposed configuration should provide both fast response times (ultra thin film) and increased sensitivity (greatly increased surface area). AFM can clearly distinguish between the different phases. The height difference between the solid-expanded and the liquid-expanded phase was measured to be 1.4 nm while the bilayer thickness was 5.6 nm. The solid domains show a 20 % decrease in fluorescence lifetime in comparison to the monolayer as measured by FLIM. This difference in lifetimes is explained in the model of fluorescence self quenching in the solid phase due to the molecules being closer to each other.

  4. Improvement of the signal-to-noise ratio of laser-induced-fluorescence photon-counting signals of single-atoms magneto-optical trap

    International Nuclear Information System (INIS)

    Employing grating extended-cavity diode lasers as the cooling/trapping and repumping lasers for preparing and manipulating single atoms, we have implemented a large-magnetic-gradient caesium magneto-optical trap (MOT). To detect and evaluate single caesium atoms trapped in MOT, laser-induced-fluorescence (LIF) photons of trapped atoms driven by MOT lasers are collected and counted by an avalanched photodiode worked in photon-counting mode. The dependences of LIF photon-counting signals of single atoms on a cooling laser's intensity, frequency detuning and frequency fluctuation are analysed and investigated. Remarkable improvement of the signal-to-noise ratio of LIF photon-counting signals is achieved by optimizing the cooling laser's intensity and frequency detuning and using the modulation-free polarization spectroscopic technique with feedback to both the slow channel (piezoelectric transducer channel with typical bandwidth of ∼2 kHz in the grating extended cavity) and the fast channel (current modulation channel with typical bandwidth of ∼200 kHz in the current driver).

  5. Speciation analysis of arsenic by hydride generation-cryotrapping-atomic fluorescence spectrometry: achieving extremely low detection limits with inexpensive instrumentation

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš; Svoboda, Milan; Selecká, Anna; Rychlovský, P.; Dědina, Jiří

    Münster, 2011. FTM17. [Internaional Symposium on Metallomics /3./. 15.06.2011-18.06.2011, Münster] R&D Projects: GA ČR GA203/09/1783 Institutional research plan: CEZ:AV0Z40310501 Keywords : arsenic speciation analysis * hydride generation * atonmic fluorescence spectrometry Subject RIV: CB - Analytical Chemistry, Separation

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

    International Nuclear Information System (INIS)

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

  7. Density relaxation and particle motion characteristics in a non-ionic deep eutectic solvent (acetamide + urea): Time-resolved fluorescence measurements and all-atom molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Das, Anuradha; Das, Suman; Biswas, Ranjit, E-mail: ranjit@bose.res.in [Chemical, Biological and Macromolecular Sciences, S. N. Bose National Centre for Basic Sciences, Block-JD, Sector-III, Salt Lake, Kolkata, West Bengal 700098 (India)

    2015-01-21

    Temperature dependent relaxation dynamics, particle motion characteristics, and heterogeneity aspects of deep eutectic solvents (DESs) made of acetamide (CH{sub 3}CONH{sub 2}) and urea (NH{sub 2}CONH{sub 2}) have been investigated by employing time-resolved fluorescence measurements and all-atom molecular dynamics simulations. Three different compositions (f) for the mixture [fCH{sub 3}CONH{sub 2} + (1 − f)NH{sub 2}CONH{sub 2}] have been studied in a temperature range of 328-353 K which is ∼120-145 K above the measured glass transition temperatures (∼207 K) of these DESs but much lower than the individual melting temperature of either of the constituents. Steady state fluorescence emission measurements using probe solutes with sharply different lifetimes do not indicate any dependence on excitation wavelength in these metastable molten systems. Time-resolved fluorescence anisotropy measurements reveal near-hydrodynamic coupling between medium viscosity and rotation of a dissolved dipolar solute. Stokes shift dynamics have been found to be too fast to be detected by the time-resolution (∼70 ps) employed, suggesting extremely rapid medium polarization relaxation. All-atom simulations reveal Gaussian distribution for particle displacements and van Hove correlations, and significant overlap between non-Gaussian (α{sub 2}) and new non-Gaussian (γ) heterogeneity parameters. In addition, no stretched exponential relaxations have been detected in the simulated wavenumber dependent acetamide dynamic structure factors. All these results are in sharp contrast to earlier observations for ionic deep eutectics with acetamide [Guchhait et al., J. Chem. Phys. 140, 104514 (2014)] and suggest a fundamental difference in interaction and dynamics between ionic and non-ionic deep eutectic solvent systems.

  8. Solid phase extraction of cadmium on 2-mercaptobenzothiazole loaded on sulfur powder in the medium of ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate and cold vapor generation-atomic absorption spectrometric determination

    International Nuclear Information System (INIS)

    A novel solid phase extractor for preconcentration of cadmium at ng L-1 levels has been developed. Cadmium ions were retained on a column packed with sulfur powder modified with 2-mercaptobenzothiazole (2-MBT) in the medium of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]+PF6-) ionic liquid. The presence of ionic liquid during modification of sulfur enhanced the retention of cadmium ions on the column. The retained cadmium ions were eluted with 2 mol L-1 solution of HCl and measured by cold vapor generation-atomic absorption spectrometry (CVG-AAS). By using reaction cell-gas liquid separator (RC-GLS), gaseous cadmium vapors were produced and reached the atomic absorption spectrometer, instantaneously. The influence of different variables on both processes of solid phase extraction and CVG-AAS determination of cadmium ions was investigated. The calibration curve was linear in the range of 10-200 ng L-1of cadmium in the initial solution with r = 0.9992 (n = 8) under optimum conditions. The limit of detection based on three times the standard deviation of the blank (3Sb, n = 10) was 4.6 ng L-1. The relative standard deviation (R.S.D.) of 25 and 150 ng L-1 of cadmium was 4.1 and 2.2% (n = 8), respectively. The procedure was validated by the analysis of a certified reference material (DORM-3), water and fish samples.

  9. Electrothermal atomic absorption spectrometric determination of vanadium in extracts of soil and sewage sludge certified reference materials after fractionation by means of the Communities Bureau of Reference modified sequential extraction procedure

    International Nuclear Information System (INIS)

    A modified three-step sequential extraction procedure proposed by the Commission of European Communities Bureau of Reference (BCR) was applied to certified reference materials of three different soil groups (rendzina, luvisol, cambisol) and sewage sludge of different composition originating from a municipal water treatment plant in order to assess potential mobility and the distribution of vanadium in the resulting fractions. Analysis of the extracts was carried out by electrothermal atomic absorption spectrometry with Zeeman background correction using transversely heated graphite atomizers. Extracts showed significant matrix interferences which were overcome by the standard addition technique. The original soil and sludge certified reference materials (CRMs) and the extraction residue from the sequential extraction were decomposed by a mixture of HNO3-HClO4-HF in an open system. The content of V determined after decomposition of the samples was in very good agreement with the certified total values. The accuracy of the sequential extraction procedure was checked by comparing the sum of the vanadium contents in the three fractions and in the extraction residue with the certified total content of V. The amounts of vanadium leached were in good correlation with the certified total contents of V in the CRMs of soils and sewage sludge. In the soils examined, vanadium was present almost entirely in the mineral lattice, while in the sewage sludge samples 9-14% was found in the oxidizable and almost 25% in the reducible fractions. The recovery ranged from 93-106% and the precision (RSD) was below 10%

  10. Aspects of optical fibers and spectrometric sensors in chemical process and industrial environments

    International Nuclear Information System (INIS)

    For on-line control, the two alternatives of automatic sample transfer and in situ remote analysis are discussed. New concepts are emerging from the possibilities offered by optical fibers. Absorption in the visible, UV and IR, fluorescence and Raman spectrometric techniques are examined. The state of the art of optodes and devices in chemical process control are given, with some examples of applications in nuclear plants

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

    International Nuclear Information System (INIS)

    A sensitive and simple solid phase extraction method for the simultaneous determination of trace and toxic metals in food samples has been reported. The method is based on the adsorption of zinc, nickel, iron and lead on sodium dodecyl sulfate (SDS)-coated alumina, which is also chelated with bis (2-hydroxyacetophenone)-1, 3-propanediimine (BHAPN). The retained analyte ions on modified solid phase were eluted using 8 mL of 4 mol L-1 HNO3. The analyte determinations were carried out by flame atomic absorption spectrometry. The influences of some metal ions and anions on the recoveries of understudy analyte ions were investigated. The proposed method has been successfully applied for the evaluation of these trace and toxic metals in some traditional food samples from Iran.

  12. Automated sequential injection-microcolumn approach with on-line flame atomic absorption spectrometric detection for implementing metal fractionation schemes of homogeneous and non-homogeneous solid samples of environmental interest

    DEFF Research Database (Denmark)

    Chomchoei, Roongrat; Miró, Manuel; Hansen, Elo Harald; Shiowatana, Juwadee

    2005-01-01

    An automated sequential injection (SI) system incorporating a dual-conical microcolumn is proposed as a versatile approach for the accommodation of both single and sequential extraction schemes for metal fractionation of solid samples of environmental concern. Coupled to flame atomic absorption...... Testing sequential extraction method have been also performed in a dynamic fashion and critically compared with the conventional batch-wise protocols. The ecotoxicological relevance of the data provided by both methods with different operationally defined conditions is thoroughly discussed. As compared to...... traditional batch systems, the developed SI assembly offers minimum risks of sample contamination, absence of metal re-distribution/re-adsorption, and dramatic saving of operational times (from 16 h to 40-80 min per partitioning step). It readily facilitates the accurate manipulation of the extracting...

  13. Surface passivation of nano-textured fluorescent SiC by atomic layer deposited TiO2

    DEFF Research Database (Denmark)

    Lu, Weifang; Ou, Yiyu; Jokubavicius, Valdas;

    2016-01-01

    Nano-textured surfaces have played a key role in optoelectronic materials to enhance the light extraction efficiency. In this work, morphology and optical properties of nano-textured SiC covered with atomic layer deposited (ALD) TiO2 were investigated. In order to obtain a high quality surface for...

  14. Comparison of nanosecond and picosecond excitation for interference-free two-photon laser-induced fluorescence detection of atomic hydrogen in flames.

    Science.gov (United States)

    Kulatilaka, Waruna D; Patterson, Brian D; Frank, Jonathan H; Settersten, Thomas B

    2008-09-10

    Two-photon laser-induced fluorescence (TP-LIF) line imaging of atomic hydrogen was investigated in a series of premixed CH4/O2/N2, H2/O2, and H2/O2/N2 flames using excitation with either picosecond or nanosecond pulsed lasers operating at 205 nm. Radial TP-LIF profiles were measured for a range of pulse fluences to determine the maximum interference-free signal levels and the corresponding picosecond and nanosecond laser fluences in each of 12 flames. For an interference-free measurement, the shape of the TP-LIF profile is independent of laser fluence. For larger fluences, distortions in the profile are attributed to photodissociation of H2O, CH3, and/or other combustion intermediates, and stimulated emission. In comparison with the nanosecond laser, excitation with the picosecond laser can effectively reduce the photolytic interference and produces approximately an order of magnitude larger interference-free signal in CH4/O2/N2 flames with equivalence ratios in the range of 0.5flames with 0.3flames, stimulated emission, occurring between the laser-excited level, H(n=3), and H(n=2), is the limiting factor for picosecond excitation in the flames with the highest H atom concentration. Nanosecond excitation is advantageous in the richest (Phi=1.64) CH4/O2/N2 flame and in H2/O2/N2 flames. The optimal excitation pulse width for interference-free H atom detection depends on the relative concentrations of hydrogen atoms and photolytic precursors, the flame temperature, and the laser path length within the flame. PMID:18784770

  15. Determination of trace total inorganic arsenic by hydride generation atomic fluorescence spectrometry after solid phase extraction-preconcentration on aluminium hydroxide gel

    International Nuclear Information System (INIS)

    We describe a simple, effective, inexpensive and rapid method for the determination of trace amounts of total inorganic arsenic in water samples by means of a modified solid phase preconcentration procedure using an aluminium hydroxide gel sorbent and hydride generation atomic fluorescence spectrometry (HGAFS). This method avoids the traditional extraction procedures that are time- and solvent-consuming. The effects of quantity of adsorbent, solution pH, adsorption time and potentially interfering ions were studied. Under the optimal conditions, the detection limit is 3 ng.L-1, and the enrichment factor is 167. The calibration plot is linear in the range from 0.05 to 10 μg.L-1, with a correlation coefficient of 0.9992. The relative standard deviation (RSD) was less than 6.1 % (n = 5) and recoveries in spiked environmental water were >100 %. The method was successfully applied to the determination of total inorganic arsenic in natural water samples. (author)

  16. In Situ Synchrotron Based X-ray Fluorescence and Scattering Measurements During Atomic Layer Deposition: Initial Growth of HfO2 on Si and Ge Substrates

    Energy Technology Data Exchange (ETDEWEB)

    K Devloo-Casier; J Dendooven; K Ludwig; G Lekens; J DHaen; C Detavernier

    2011-12-31

    The initial growth of HfO{sub 2} was studied by means of synchrotron based in situ x-ray fluorescence (XRF) and grazing incidence small angle x-ray scattering (GISAXS). HfO{sub 2} was deposited by atomic layer deposition (ALD) using tetrakis(ethylmethylamino)hafnium and H{sub 2}O on both oxidized and H-terminated Si and Ge surfaces. XRF quantifies the amount of deposited material during each ALD cycle and shows an inhibition period on H-terminated substrates. No inhibition period is observed on oxidized substrates. The evolution of film roughness was monitored using GISAXS. A correlation is found between the inhibition period and the onset of surface roughness.

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

    International Nuclear Information System (INIS)

    A new solid-phase extraction sorbent was used for the preconcentration of Pb(II) and Cr(III) ions prior to their determination by flame atomic absorption spectrometry. It was prepared by immobilization of 2,4-dinitrophenylhydrazine on nano-alumina coated with sodium dodecyl sulfate. The sorbent was characterized by scanning electron microscopy, N2 adsorption and Fourier transform infrared spectrometry, and used for preconcentration and separation of Pb(II) and Cr(III) from aqueous solutions. The ions on the sorbent were eluted with a mixture of nitric acid and methanol. The effects of sample pH, flow rates of samples and eluent, type of eluent, breakthrough volume and potentially interfering ions were studied. Linearity is maintained between 1.2 and 350 μg L-1 of Pb(II), and between 2.4 and 520 μg L-1 of Cr(III) for an 800-mL sample. The detection limit (3 s, N=10) for Pb(II) and Cr(III) ions is 0.43 and 0.55 μg L-1, respectively, and the maximum preconcentration factor is 267. The method was successfully applied to the evaluation of these trace and toxic metals in various water, food, industrial effluent and urine samples. (author)

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

    Science.gov (United States)

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

    2006-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-07-15

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

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

    International Nuclear Information System (INIS)

    A novel non-chromatographic approach for direct speciation of mercury, based on the selective retention inorganic mercury and methylmercury on the inner wall of a knotted reactor by using ammonium diethyl dithiophosphate and dithizone as complexing agents respectively, was developed for flow injection on-line sorption preconcentration coupled with chemical vapor generation non-dispersive atomic fluorescence spectrometry. With the sample pH kept at 2.0, the preconcentration of inorganic mercury on the inner walls of the knotted reactor was carried out based on the exclusive retention of Hg-DDP complex in the presence of methylmercury via on-line merging the sample solution with ammonium diethyl dithiophosphate solution, and selective preconcentration methylmercury was achieved with dithizone instead of ammonium diethyl dithiophosphate. A 15% (v/v) HCl was introduced to elute the retained mercury species and merge with KBH4 solution for atomic fluorescence spectrometry detection. Under the optimal experimental conditions, the sample throughputs of inorganic mercury and methylmercury were 30 and 20 h-1 with the enhancement factors of 13 and 24. The detection limits were found to be 3.6 ng l-1 for Hg2+ and 2.0 ng l-1 for CH3Hg+. The precisions (RSD) for the 11 replicate measurements of each 0.2 μg l-1 of Hg2+ and CH3Hg+ were 2.2% and 2.8%, respectively. The developed method was validated by the analysis of certified reference materials (simulated natural water, rice flour and pork) and by recovery measurements on spiked samples, and was applied to the determination of inorganic mercury and methylmercury in biological and environmental water samples

  1. Diagnostics of Carbon Nanotube Formation in a Laser Produced Plume: An Investigation of the Metal Catalyst by Laser Ablation Atomic Fluorescence Spectroscopy

    Science.gov (United States)

    deBoer, Gary; Scott, Carl

    2003-01-01

    Carbon nanotubes, elongated molecular tubes with diameters of nanometers and lengths in microns, hold great promise for material science. Hopes for super strong light-weight material to be used in spacecraft design is the driving force behind nanotube work at JSC. The molecular nature of these materials requires the appropriate tools for investigation of their structure, properties, and formation. The mechanism of nanotube formation is of particular interest because it may hold keys to controlling the formation of different types of nanotubes and allow them to be produced in much greater quantities at less cost than is currently available. This summer's work involved the interpretation of data taken last summer and analyzed over the academic year. The work involved diagnostic studies of carbon nanotube formation processes occurring in a laser-produced plume. Laser ablation of metal doped graphite to produce a plasma plume in which carbon nanotubes self assemble is one method of making carbon nanotube. The laser ablation method is amenable to applying the techniques of laser spectroscopy, a powerful tool for probing the energies and dynamics of atomic and molecular species. The experimental work performed last summer involved probing one of the metal catalysts, nickel, by laser induced fluorescence. The nickel atom was studied as a function of oven temperature, probe laser wavelength, time after ablation, and position in the laser produced plume. This data along with previously obtained data on carbon was analyzed over the academic year. Interpretations of the data were developed this summer along with discussions of future work. The temperature of the oven in which the target is ablated greatly influences the amount of material ablated and the propagation of the plume. The ablation conditions and the time scale of atomic and molecular lifetimes suggest that initial ablation of the metal doped carbon target results in atomic and small molecular species. The metal

  2. Spectrometric analysis of process etching solutions of the photovoltaic industry--determination of HNO3, HF, and H2SiF6 using high-resolution continuum source absorption spectrometry of diatomic molecules and atoms.

    Science.gov (United States)

    Bücker, Stefan; Acker, Jörg

    2012-05-30

    The surface of raw multicrystalline silicon wafers is treated with HF-HNO(3) mixtures in order to remove the saw damage and to obtain a well-like structured surface of low reflectivity, the so-called texture. The industrial production of solar cells requires a consistent level of texturization for tens of thousands of wafers. Therefore, knowing the actual composition of the etch bath is a key element in process control in order to maintain a certain etch rate through replenishment of the consumed acids. The present paper describes a novel approach to quantify nitric acid (HNO(3)), hydrofluoric acid (HF), and hexafluosilicic acid (H(2)SiF(6)) using a high-resolution continuum source graphite furnace absorption spectrometer. The concentrations of Si (via Si atom absorption at the wavelength 251.611 nm, m(0),(Si)=130 pg), of nitrate (via molecular absorption of NO at the wavelength 214.803 nm, [Formula: see text] ), and of total fluoride (via molecular absorption of AlF at the wavelength 227.46 nm, m(0,F)=13 pg) were measured against aqueous standard solutions. The concentrations of H(2)SiF(6) and HNO(3) are directly obtained from the measurements. The HF concentration is calculated from the difference between the total fluoride content, and the amount of fluoride bound as H(2)SiF(6). H(2)SiF(6) and HNO(3) can be determined with a relative uncertainty of less than 5% and recoveries of 97-103% and 96-105%, respectively. With regards to HF, acceptable results in terms of recovery and uncertainty are obtained for HF concentrations that are typical for the photovoltaic industry. The presented procedure has the unique advantage that the concentration of both, acids and metal impurities in etch solutions, can be routinely determined by a single analytical instrument. PMID:22608457

  3. Bovine serum albumin-Cu(II) hybrid nanoflowers: An effective adsorbent for solid phase extraction and slurry sampling flame atomic absorption spectrometric analysis of cadmium and lead in water, hair, food and cigarette samples.

    Science.gov (United States)

    Yilmaz, Erkan; Ocsoy, Ismail; Ozdemir, Nalan; Soylak, Mustafa

    2016-02-01

    Herein, the synthesis of bovine serum albumin-Cu(II) hybrid nanoflowers (BSA-NFs) through the building blocks of bovine serum albumin (BSA) and copper(II) ions in phosphate buffered saline (PBS) and their use as adsorbent for cadmium and lead ions are reported. The BSA-NFs, for the first time, were efficiently utilized as novel adsorbent for solid phase extraction (SPE) of cadmium and lead ions in water, food, cigarette and hair samples. The method is based on the separation and pre-concentration of Cd(II) and Pb(II) by BSA-NFs prior to determination by slurry analysis via flame atomic absorption spectrometry (FAAS). The analytes were adsorbed on BSA-NFs under the vortex mixing and then the ion-loaded slurry was separated and directly introduced into the flame AAS nebulizer by using a hand-made micro sample introduction system to eliminate a number of drawbacks. The effects of analytical key parameters, such as pH, amount of BSA-NFs, vortexing time, sample volume, and matrix effect of foreign ions on adsorbing of Cd(II) and Pb(II) were systematically investigated and optimized. The limits of detection (LODs) for Cd(II) and Pb(II) were calculated as 0.37 μg L(-)(1) and 8.8 μg L(-)(1), respectively. The relative standard deviation percentages (RSDs) (N = 5) for Cd(II) and Pb(II) were 7.2%, and 5.0%, respectively. The accuracy of the developed procedure was validated by the analysis of certified reference materials (TMDA-53.3 Fortified Water, TMDA-70 Fortified Water, SPS-WW2 Waste Water, NCSDC-73349 Bush Branches and Leaves) and by addition/recovery analysis. The quantitative recoveries were obtained for the analysis of certified reference materials and addition/recovery tests. The method was successfully applied to the analysis of cadmium and lead in water, food, cigarette and hair samples. PMID:26772130

  4. Direct analysis of environmental and biological samples for total mercury with comparison of sequential atomic absorption and fluorescence measurements from a single combustion event

    International Nuclear Information System (INIS)

    A Direct Mercury Analyzer (DMA) based on sample combustion, concentration of mercury by amalgamation with gold, and cold vapor atomic absorption spectrometry (CVAAS) was coupled to a mercury-specific cold vapor atomic fluorescence spectrometer (CVAFS). The purpose was to evaluate combustion-AFS, a technique which is not commercially available, for low-level analysis of mercury in environmental and biological samples. The experimental setup allowed for comparison of dual measurements of mercury (AAS followed by AFS) for a single combustion event. The AFS instrument control program was modified to properly time capture of mercury from the DMA, avoiding deleterious combustion products from reaching its gold traps. Calibration was carried out using both aqueous solutions and solid reference materials. The absolute detection limits for mercury were 0.002 ng for AFS and 0.016 ng for AAS. Recoveries for reference materials ranged from 89% to 111%, and the precision was generally found to be <10% relative standard deviation (RSD). The two methods produced similar results for samples of hair, finger nails, coal, soil, leaves and food stuffs. However, for samples with mercury near the AAS detection limit (e.g., filter paper spotted with whole blood and segments of tree rings) the signal was still quantifiable with AFS, demonstrating the lower detection limit and greater sensitivity of AFS. This study shows that combustion-AFS is feasible for the direct analysis of low levels of mercury in solid samples that would otherwise require time-consuming and contamination-prone digestion.

  5. Spectrometric mixture analysis: An unexpected wrinkle

    Indian Academy of Sciences (India)

    Robert De Levie

    2009-09-01

    The spectrometric analysis of a mixture of two chemically and spectroscopically similar compounds is illustrated for the simultaneous spectrometric determination of caffeine and theobromine, the primary stimulants in coffee and tea, based on their ultraviolet absorbances. Their analysis indicates that such measurements may need an unexpectedly high precision to yield accurate answers, because of an artifact of inverse cancellation, in which a small noise or drift signal is misinterpreted in terms of a concentration difference. The computed sum of the concentrations is not affected.

  6. Spatial dynamics of laser-induced fluorescence in an intense laser beam: experiment and theory in alkali metal atoms

    CERN Document Server

    Auzinsh, Marcis; Ferber, Ruvin; Gahbauer, Florian; Kalnins, Uldis

    2015-01-01

    We have shown that it is possible to model accurately optical phenomena in intense laser fields by taking into account the intensity distribution over the laser beam. We developed a theoretical model that divided an intense laser beam into concentric regions, each with a Rabi frequency that corresponds to the intensity in that region, and solved a set of coupled optical Bloch equations for the density matrix in each region. Experimentally obtained magneto-optical resonance curves for the $F_g=2\\longrightarrow F_e=1$ transition of the $D_1$ line of $^{87}$Rb agreed very well with the theoretical model up to a laser intensity of around 200 mW/cm$^2$ for a transition whose saturation intensity is around 4.5 mW/cm$^2$. We have studied the spatial dependence of the fluorescence intensity in an intense laser beam experimentally and theoretically. An experiment was conducted whereby a broad, intense pump laser excited the $F_g=4\\longrightarrow F_e=3$ transition of the $D_2$ line of cesium while a weak, narrow probe ...

  7. Utilization of fluorescence in situ hybridization (FISH) technique for detection of radiation-induced translocations in atomic bomb survivors

    International Nuclear Information System (INIS)

    This paper summarizes recent progress in a collaborative study by Radiation Effects Research Foundation, Hiroshima, Lawrence Livermore National Laboratory and university of California, San Francisco, to investigate the utility of fluorescence in situ hybridization (FISH) with whole-chromosome probes (chromosomes 1, 2 and 4) for measurement of the frequencies of chromosomal translocations that have persisted for decades in the peripheral blood lymphocytes of A-bomb survivors. The frequencies of radiation-induced translocations measured between FISH and G-band/conventional stains for 33 Hiroshima a-bomb survivors (7 distally and 26 proximally exposed survivors with estimated DS86 bone marrow dose ranging from 0-3.0 Sv). Findings showed that, except for a few discrepant cases, translocation frequencies from the same survivors agree reasonably well between FISH and G-banding, provides the assumption that the number of breaks involved in the radiation-induced translocations increases linearly with chromosomal dna content. Present findings have validated that the FISH technique is a useful biological assay system for rapid and accurate detection of persistent translocations for quantification of previous exposures to ionizing radiation. (author). 9 refs

  8. Determination of the electromagnetic dipole strength distribution in medium-heavy atomic nuclei by means of nuclear resonance fluorescence

    International Nuclear Information System (INIS)

    During the last hundred years several models were developed to describe the configuration of nuclei. These models have to make predictions, which should be comparable with experiments. As a standard type of experiment the nuclear resonance fluorescence was established. A nucleus is excited by irradiation with photons. By emitting one or more photons the nucleus decays back to the ground state. With this method it is possible to measure energy levels and to determine the strength of their excitation. A continuum of unresolved peaks gives additional strength. The existing setup at the linear electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf uses bremsstrahlung, produced as a secondary beam in a thin Niobium foil. During the years 2008/09 experiments on the nuclei of 86Kr and 136Ba took place there. In this work they will be analyzed. Photon flux and efficiency determination have been done as well as simulations on detector response and non-nuclear scattered background events. For this purpose the GEANT4 package was used. Finally the resulting cross sections were corrected for branching and feeding.

  9. On the fast response of spectrometric circuits

    International Nuclear Information System (INIS)

    Information capacity of spectrometric circuits obtianed by means of Monte Carlo method modeling is analysed. It is shown that working at high input pulse counting rate is not advisable, dead time of analog-to-digital converter should be compared with the pulse rise time of the amplifier

  10. Gamma spectrometric assessment of nuclear fuel

    Science.gov (United States)

    Krištof, Edvard; Pregl, Gvido

    1990-12-01

    A description is given of a gamma spectrometric technique which has been developed with the aim of determining the amount of a certain radioactive fission product taking into consideration local variations of the linear attenuation coefficient of gamma rays. Also, an experiment using a fuel element of the TRIGA Mark II reactor in Ljubljana is presented.

  11. [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

  12. In situ preparation and fluorescence quenching properties of polythiophene/ZnO nanocrystals hybrids through atom-transfer radical polymerization and hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Peng Xiaoming; Zhang Lin [Department of Chemistry, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Chen Yiwang, E-mail: ywchen@ncu.edu.cn [Department of Chemistry, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Li Fan, E-mail: lfan@ncu.edu.cn [Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China); Zhou Weihua [Institute of Polymers/Institute for Advanced study, Nanchang University, Xuefu Road 999, Nanchang 330031 (China)

    2010-02-15

    In this paper, a new approach for in situ preparing nanocomposites of conjugated polymers (CPs) and semiconductor nanocrystals was developed. Polythiophene grafted poly(zinc methacrylate) (PTh-g-PZMA) copolymer was synthesized by atom-transfer radical polymerization (ATRP) of zinc methacrylate (ZMA) initiated from the macroinitiator poly(2,5-(3-(bromoisopropyl-carbonyl-oxymethylene) thiophene)) (PTh-Br) with pendant initiator groups. Subsequently, the polythiophene grafted poly(methacrylate)/ZnO (PTh-g-PMA/ZnO) hybrid heterojunction nanocomposites were successfully prepared by in situ hydrolysis of PTh-g-PZMA casting films in alkaline aqueous solution. The structures of PTh-Br, PTh-g-PZMA and PTh-g-PMA/ZnO were confirmed by the proton nuclear magnetic resonance ({sup 1}H NMR) spectra, Fourier transform infrared (FTIR) spectra and X-ray photoelectron spectroscopy (XPS). The morphologies of PTh-g-PMA/ZnO films prepared for different hydrolysis time were observed in the cross-sections by scanning electron microscope (SEM). The SEM images revealed that ZnO nanocrystals were uniformly dispersed in polymers without any aggregation and the appearances of ZnO nanocrystals changed from nanoparticles to nanorods with the hydrolysis treatment time increasing. The optical properties of these nanocomposites were studied by ultraviolet-visible (UV-vis) absorption and fluorescence spectroscopy. UV-vis absorption spectroscopy showed that the adsorption band of PTh-g-PMA/ZnO hybrids was broader than that of PTh-Br, implying that the existence of ZnO nanocrystals increased the optical absorption region of hybrids. The photoluminescence (PL) spectra of the hybrids showed that fluorescence quenching occurred in PTh-g-PMA/ZnO blends and a maximum of 85% of the fluorescence intensity quenched in the PTh-g-PMA/ZnO obtained from treatment in NaOH aqueous solution for 2 h, which revealed the existence of photo-induced charge transfer between the polythiophene chains and ZnO. These results

  13. 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.

  14. 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

    International Nuclear Information System (INIS)

    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. - 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

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

    Science.gov (United States)

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

    2011-11-01

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

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

    International Nuclear Information System (INIS)

    In the present work, a novel solid polymer electrolyte hydride generation (SPE-HG) cell was developed. The home-made SPE-HG cell, mainly composed of three components (Nafion®117 membrane for separating and H+ exchanging, a soft graphite felt cathode and a Ti mesh modified by Ir anode), was employed for detecting As by coupling to atomic fluorescence spectrometry (AFS). The H+ generated by electrolysis of pure water in anode chamber transferred to cathode chamber through SPE, and immediately reacted with As3+ to generate AsH3. The relative mechanisms and operation conditions for hydride generation of As were investigated in detail. The developed cell employed water as an alternative of acid anolyte, with virtues of low-cost, more than 6 months lifetime and environment friendly compared with the conventional cell. Under the optimized conditions, the limit of determination of As3+ for sample blank solution was 0.12 μg L−1, the RSD was 2.9% for 10 consecutive measurements of 5 μg L−1 As3+ standard solution. The accuracy of the method was verified by the determination of As in the reference Tea (GBW07605) and the developed method was successfully applied to determine trace amounts of As in tobacco samples with recovery from 97% to 103%.

  17. Determination of As in tobacco by using electrochemical hydride generation at a Nafion Registered-Sign solid polymer electrolyte cell hyphenated with atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang Qinghua; Gan Wuer, E-mail: wgan@ustc.edu.cn; Deng Yun; Sun Huihui

    2011-11-15

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

  18. 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.

  19. Application of Graphene as a Sorbent for the Preconcentration and Determination of Trace Amounts of Mercury in Water Samples by Hydride Generation Atomic Fluorescence Spectrometry

    International Nuclear Information System (INIS)

    The potential of graphene as a solid-phase extraction adsorbent for the separation and preconcentration of mercury (Hg) was investigated. Hg2+ was found to be quantitatively adsorbed onto graphene within pH 6.0-8.0, and then completely eluted with 4.0 mL of nitric acid/methanol (1:1, v/v) solution at a flow rate of 2.0 mL min-1. A new method using a microcolumn packed with graphene as a sorbent was developed for the preconcentration of trace amount of Hg2+ prior to its determination by hydride generation atomic fluorescence spectrometry. Under the optimum experimental conditions, the detection limit of this method for Hg2+ was 5.0 ng L /sup -1/, with an enrichment factor of 15.0, and the relative standard deviation was 3.5 percentage at the 1.0 μg L-1 Hg /sup 2+/ level. The method was then applied for the determination of trace amount of Hg /sup 2/+ in water samples with satisfactory results. (author)

  20. Absolute atomic oxygen density measurements for nanosecond-pulsed atmospheric-pressure plasma jets using two-photon absorption laser-induced fluorescence spectroscopy

    Science.gov (United States)

    Jiang, C.; Carter, C.

    2014-12-01

    Nanosecond-pulsed plasma jets that are generated under ambient air conditions and free from confinement of electrodes have become of great interest in recent years due to their promising applications in medicine and dentistry. Reactive oxygen species that are generated by nanosecond-pulsed, room-temperature non-equilibrium He-O2 plasma jets among others are believed to play an important role during the bactericidal or sterilization processes. We report here absolute measurements of atomic oxygen density in a 1 mm-diameter He/(1%)O2 plasma jet at atmospheric pressure using two-photon absorption laser-induced fluorescence spectroscopy. Oxygen number density on the order of 1013 cm-3 was obtained in a 150 ns, 6 kV single-pulsed plasma jet for an axial distance up to 5 mm above the device nozzle. Temporally resolved O density measurements showed that there are two maxima, separated in time by 60-70 µs, and a total pulse duration of 260-300 µs. Electrostatic modeling indicated that there are high-electric-field regions near the nozzle exit that may be responsible for the observed temporal behavior of the O production. Both the field-distribution-based estimation of the time interval for the O number density profile and a pulse-energy-dependence study confirmed that electric-field-dependent, direct and indirect electron-induced processes play important roles for O production.

  1. 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.)

  2. Interaction analysis of chimeric metal-binding green fluorescent protein and artificial solid-supported lipid membrane by quartz crystal microbalance and atomic force microscopy

    International Nuclear Information System (INIS)

    Non-specific adsorption and specific interaction between a chimeric green fluorescent protein (GFP) carrying metal-binding region and the immobilized zinc ions on artificial solid-supported lipid membranes was investigated using the quartz crystal microbalance technique and the atomic force microscopy (AFM). Supported lipid bilayer, composed of octanethiol and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine/1,2-dioleoyl-sn-glycero-3-[N- (5-amino-1-carboxypentyl iminodiacetic acid)succinyl] (NTA-DOGS)-Zn2+, was formed on the gold electrode of quartz resonator (5 MHz). Binding of the chimeric GFP to zinc ions resulted in a rapid decrease of resonance frequency. Reversibility of the process was demonstrated via the removal of metal ions by EDTA. Nanoscale structural orientation of the chimeric GFP on the membrane was imaged by AFM. Association constant of the specific binding to metal ions was 2- to 3-fold higher than that of the non-specific adsorption, which was caused by the fluidization effect of the metal-chelating lipid molecules as well as the steric hindrance effect. This infers a possibility for a further development of biofunctionalized membrane. However, maximization is needed in order to attain closer advancement to a membrane-based sensor device

  3. Absolute atomic oxygen density measurements for nanosecond-pulsed atmospheric-pressure plasma jets using two-photon absorption laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Nanosecond-pulsed plasma jets that are generated under ambient air conditions and free from confinement of electrodes have become of great interest in recent years due to their promising applications in medicine and dentistry. Reactive oxygen species that are generated by nanosecond-pulsed, room-temperature non-equilibrium He–O2 plasma jets among others are believed to play an important role during the bactericidal or sterilization processes. We report here absolute measurements of atomic oxygen density in a 1 mm-diameter He/(1%)O2 plasma jet at atmospheric pressure using two-photon absorption laser-induced fluorescence spectroscopy. Oxygen number density on the order of 1013 cm−3 was obtained in a 150 ns, 6 kV single-pulsed plasma jet for an axial distance up to 5 mm above the device nozzle. Temporally resolved O density measurements showed that there are two maxima, separated in time by 60–70 µs, and a total pulse duration of 260−300 µs. Electrostatic modeling indicated that there are high-electric-field regions near the nozzle exit that may be responsible for the observed temporal behavior of the O production. Both the field-distribution-based estimation of the time interval for the O number density profile and a pulse-energy-dependence study confirmed that electric-field-dependent, direct and indirect electron-induced processes play important roles for O production. (paper)

  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

    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.

  5. Evaluation of different extraction procedures for determination of organic Mercury species in petroleum by high performance liquid chromatography coupled with cold vapor atomic fluorescence spectrometry.

    Science.gov (United States)

    Yun, Zhaojun; He, Bin; Wang, Zhenhua; Wang, Thanh; Jiang, Guibin

    2013-03-15

    An extraction procedure for extracting organic mercury species including methylmercury (MeHg) and ethylmercury (EtHg) from petroleum samples was developed. Three extraction methods (shaking, ultrasonic and microwave assisted extraction) using different extraction solvents (TMAH, KOH/CH3OH, HCl and acidic CuSO4/KBr) were investigated by comparing the extraction efficiency of the organic mercury species. Microwave assisted extraction at 60 W for 5 min using TMAH (tetramethylammonium hydroxide, 25%, m/v) provided the most satisfactory extraction efficiency for MeHg and EtHg in petroleum at 86.7% ± 3.4% and 70.6% ± 5.9%, respectively. Speciation analysis of mercury was done by on-line coupling of high performance liquid chromatography with cold vapor generation atomic fluorescence spectrometry (HPLC-CV-AFS). The proposed method was successfully applied to analyze several crude oil and light oil samples. The concentrations of MeHg ranged from under detection limit to 0.515 ng g(-1), whereas EtHg was not detected in the samples. This method can be a very useful tool in evaluating the risk of mercury emissions from petroleum. PMID:23598095

  6. Determination of As(III) and As(V) in soils using sequential extraction combined with flow injection hydride generation atomic fluorescence detection

    International Nuclear Information System (INIS)

    An analytical procedure for determination of As(III) and As(V) in soils using sequential extraction combined with flow injection (FI) hydride generation atomic fluorescence spectrometry (HG-AFS) was presented. The soils were sequentially extracted by water, 0.6 mol l-1 KH2PO4 solution, 1% (v/v) HCl solution and 1% (w/v) NaOH solution. The arsenite (As(III)) in extract was analyzed by HG-AFS in the medium of 0.1 mol l-1 citric acid solution, then the total arsenic in extract was determined by HG-AFS using on-line reduction of arsenate with L-cysteine. The concentration of arsenate (As(V)) was calculated by the difference. The optimum conditions of extraction and determination were studied in detail. The detection limit (3σ) for As(III) and As(V) were 0.11 and 0.07 μg l-1, respectively. The relative standard deviation (R.S.D.) was 1.43% (n=11) at the 10 μg l-1 As level. The method was applied in the determination of As(III) and As(V) of real soils and the recoveries of As(III) and As(V) were in the range of 89.3-118 and 80.4-111%, respectively

  7. 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. PMID:26988526

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

    International Nuclear Information System (INIS)

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

  9. The analysis of comet mass spectrometric data

    Science.gov (United States)

    Balm, S. P.; Hare, J. P.; Kroto, H. W.

    1991-04-01

    The mass spectra from the Giotto PICCA experiment have been studied using computer simulations based on tabulated mass spectrometric data. It is shown that random mixtures of organic compounds give rise to mass spectra with peaks at about 45, 60, 75, and 90 amu; i.e., separated by about 15 amu. In particular it is shown that the products of Urey-Miller type experiments give mass spectra which can match the observed Giotto data closely. The analysis indicates that the material consists mainly of C/H/O/N (i.e., it is organic), but that the assignment to any well defined organic material is less certain. It is not clear that mass spectrometric studies of complex mixtures have the prospect of yielding this type of information without some form of preseparation.

  10. 原子荧光分光光度法检测人尿中锡%Detection of tin in human urine by atomic fluorescence spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    郭晓婧; 郭嘉明; 梁嘉斌; 刘移民

    2016-01-01

    Objective To establish a method for determination of urinary tin by atomic fluorescence spectrophotometry . Methods The graphite digestion instrument was used to digest 2.50 mL urinary sample with 1.50 mL concentrated nitric acid, hydrochloric acid (volume fraction 4.00%) was added to a total constant volume of 10.00 mL.After 2.50 mL of thiocarbamide-ascorbic acid (mass concentration 100 g/L) was added, hydrochloric acid (volume fraction 4.00%) was added to a total constant volume of 25.00 mL ( equivalent to urinary sample was diluted 10 times) , 1.00 mL of the sample was collected and detected by atomic fluorescence spectrophotometry .Results The good linear relationship was shown in the range of 4.00-200.00 μg/L with a correlation coefficient of 0.999 5.The limit of detection was 0.20 μg/L.The recovery rates ranged from 100.20%to 100.84%.The within-run relative standard deviation ( RSD) and between-run RSD were 0.11%-2.01%and 1.37%-5.58%, respectively .The samples can be stored for 7 days under the temperature of 4 ℃.Conclusion This method has the advantages of high sensitivity , precision and convenient operation , which is suitable for the daily determination of urinary tin in human .%目的:建立尿中锡的原子荧光分光光度测定方法。方法取2.50 mL尿样加入1.50 mL浓硝酸后,用石墨消解仪消化,以体积分数为4.00%的盐酸溶液定容至10.00 mL,加入质量浓度为100 g/L的硫脲-抗坏血酸2.50 mL,以体积分数为4.00%的盐酸溶液定容至25.00 mL(相当于稀释尿样10倍)后,取1.00 mL样品采用原子荧光光度法进行测定。结果尿中锡在质量浓度为4.00~200.00μg/L 范围内线性关系良好,相关系数为0.9995;方法检出限为0.20μg/L,加标回收率为100.20%~100.84%,批内相对标准偏差( RSD)为0.11%~2.01%,批间RSD为1.37%~5.58%;样品在4℃条件下可保存7 d。结论本方法灵敏

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

    International Nuclear Information System (INIS)

    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−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 (Hg2+, CH3Hg+, C2H5Hg+, and C6H5Hg+). 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−1 for CH3Hg+, 13 ng L−1 for Hg2+, 34 ng L−1 for C2H5Hg+ and 30 ng L−1 for C6H5Hg+ for 24 h DGT accumulation at 25 °C

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Thiomersal was determined on line using FI-MW/UV-CVGAFS. •MW/UV allows a “green” on line oxidation of organic mercury to HgII. •Each measure requires less than 5 min with a LOD of 3 ng mL−1 (as mercury). •Hg concentration in commercial ophthalmic solutions ranges between 7.5 and 59.0 μg mL−1. -- Abstract: We developed a flow injection (FI) method for the determination of thiomersal (sodium ethylmercurithiosalicylate, C9H9HgNaO2S) based on the UV/microwave (MW) photochemical, online oxidation of organic mercury, followed by cold vapor generation atomic fluorescence spectrometry (CVG-AFS) detection. Thiomersal was quantitatively converted in the MW/UV process to Hg(II), with a yield of 97 ± 3%. This reaction was followed by the reduction of Hg(II) to Hg(0) performed in a knotted reaction coil with NaBH4 solution, and AFS detection in an Ar/H2 miniaturized flame. The method was linear in the 0.01–2 μg mL−1 range, with a LOD of 0.003 μg mL−1. This method has been applied to the determination of thiomersal in ophthalmic solutions, with recoveries ranging between 97% and 101%. We found a mercury concentration in commercial ophthalmic solutions ranging between 7.5 and 59.0 μg mL−1

  14. 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. PMID:26781421

  15. Development of a non-chromatographic method for the speciation analysis of inorganic antimony in mushroom samples by hydride generation atomic fluorescence spectrometry

    Science.gov (United States)

    Sousa Ferreira, Hadla; Costa Ferreira, Sergio Luis; Cervera, M. Luisa; de la Guardia, Miguel

    2009-06-01

    A simple and sensitive method has been developed for the direct determination of toxic species of antimony in mushroom samples by hydride generation atomic fluorescence spectrometry (HG AFS). The determination of Sb(III) and Sb(V) was based on the efficiency of hydride generation employing NaBH 4, with and without a previous KI reduction, using proportional equations corresponding to the two different measurement conditions. The extraction efficiency of total antimony and the stability of Sb(III) and Sb(V) in different extraction media (nitric, sulfuric, hydrochloric, acetic acid, methanol and ethanol) were evaluated. Results demonstrated that, based on the extraction yield and the stability of extracts, 0.5 mol L - 1 H 2SO 4 proved to be the best extracting solution for the speciation analysis of antimony in mushroom samples. The limits of detection of the developed methodology were 0.6 and 1.1 ng g - 1 for Sb(III) and Sb(V), respectively. The relative standard derivation was 3.8% (14.7 ng g - 1 ) for Sb(V) and 5.1% (4.6 ng g - 1 ) for Sb(III). The recovery values obtained for Sb(III) and Sb(V) varied from 94 to 106% and from 98 to 105%, respectively. The method has been applied to determine Sb(III), Sb(V) and total Sb in five different mushroom samples; the Sb(III) content varied from 4.6 to 11.4 ng g - 1 and Sb(V) from 14.7 to 21.2 ng g - 1 . The accuracy of the method was confirmed by the analysis of a certified reference material of tomato leaves.

  16. Arsenic speciation in edible alga samples by microwave-assisted extraction and high performance liquid chromatography coupled to atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► Total As and As species were analyzed in edible marine algae. ► A microwave-assisted extraction method with deionized water was applied. ► As compounds identified comprised DMA, As(V) and four arsenosugars ► 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 μg g−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 μg g−1, whereas sulfonate and sulfate sugars were only detected in three of them (0.6-7.2 μg g−1). Regarding arsenic toxic species, low concentration levels of dimethylarsinic acid (DMA) (−1) and generally high arsenate (As(V)) concentrations (up to 77 μg g−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.

  17. Eggshell membrane-based solid-phase extraction combined with hydride generation atomic fluorescence spectrometry for trace arsenic(V) in environmental water samples.

    Science.gov (United States)

    Zhang, Yongjiang; Wang, Weidong; Li, Lu; Huang, Yuming; Cao, Jia

    2010-03-15

    The eggshell membrane (ESM) contains several surface functional groups such as amines, amides and carboxylic groups with potential as SPE adsorbent for the retention of target species of interest. In this paper, the potential use of ESM, a typical biomaterial, as solid-phase extraction (SPE) adsorbent is evaluated for analysis of trace arsenic(V) in environmental water samples in combination with hydride generation atomic fluorescence spectrometry (HG-AFS). In order to obtain the satisfactory recovery of arsenic(V), various parameters including the desorption and enrichment conditions such as pH, the flow rate and the volume of sample solution, the amount of ESM and the content of sodium chloride were systematically optimized and the effects of co-existed ions were also investigated in detail. Under the optimal conditions, arsenic(V) could be easily extracted by the ESM packed cartridge and the breakthrough adsorption capacity was found to be 3.9 microg g(-1). The favorable limit of detection (LOD) for arsenic(V) was found to be 0.001 microg L(-1) with an enrichment factor of 33.3, and the relative standard deviations (R.S.Ds) was 2.1% for 0.6 microg L(-1) arsenic (n=11). The reproducibility among columns was satisfactory (R.S.D. among columns is less than 5%). The proposed method has been successfully applied to analysis of arsenic(V) in aqueous environmental samples, which suggests the ESM can be an excellent SPE adsorbent for arsenic(V) pretreatment and enrichment from real water samples. PMID:20152431

  18. 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.

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    Bismuthine was on-line trapped on tungsten coil and subsequently electrothermally vaporized for the determination by atomic fluorescence spectrometry (AFS). Several noble metals, including Pd, Rh, Pt, and Ir, were explored as permanent chemical modifier for tungsten coil on-line trapping. Investigation showed that Ir gave the best performance, in which bismuthine was on-line trapped on Ir-coated tungsten coil at 560 oC, and then released at 1550 oC for subsequent transfer to AFS by a mixture of Ar and H2. Under optimum instrumental conditions, the trapping efficiency was found to be 73 ± 3%. With 120 s (12 mL sample volume) trapping time, a limit of detection (LOD) of 4 ng L-1 was obtained, compared to conventional hydride generation AFS (0.09 μg L-1); the LOD can be lowered down to 1 ng L-1 by increasing the trapping time to 480 s. The LOD was found to be better or at least comparable to literature levels involving on-line trapping and some other sophisticated instrumental methods such as ICP-MS and GF-AAS. A comprehensive interference study involving conventional hydride-forming elements and some transition metals was carried out, and the result showed that the gas phase interference from other hydride-forming elements was largely reduced, thanks to the use of on-line tungsten coil trapping. Finally, the proposed method was applied to the determination of bismuth in several biological and environmental standard reference materials, and a t-test shows that the analytical results by the proposed method have no significant difference from the certified values at the confidence level of 95%

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-04

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

  2. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1998-01-01

    This volume continues the series'' cutting-edge reviews on developments in this field. Since its invention in the 1920s, electrostatic precipitation has been extensively used in industrial hygiene to remove dust and particulate matter from gases before entering the atmosphere. This combination of electrostatic precipitation is reported upon in the first chapter. Following this, chapter two reviews recent advances in the area of chemical modification in electrothermal atomization. Chapter three consists of a review which deal with advances and uses of electrothermal atomization atomic absorption spectrometry. Flow injection atomic spectroscopy has developed rapidly in recent years and after a general introduction, various aspects of this technique are looked at in chapter four. Finally, in chapter five the use of various spectrometric techniques for the determination of mercury are described.

  3. Mass spectrometric examinations of Hungarian triassic dolomites

    International Nuclear Information System (INIS)

    A limited number of mass spectrometric investigations (viz.:57) of representative rock types were applied both in the research work of geology and the mining for the industry of building materials of Hungary. Tabulated results covering all rock types and all stratigraphic levels of the Hungarian Triassic are given. Sr, Mn, Ti and Cr trace elements had the highest occurrence and Zn, Y or Pb, Ba, V or Cu, depending on the genetical type of the rock studied, has relatively higher concentrations as well. The results of the examinations of Hungarian Triassic dolomites were discussed according to genetical types, all represented by a small level of trace elements. (Sz.J.)

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

    International Nuclear Information System (INIS)

    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−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

  5. Ionic liquid-based zinc oxide nanofluid for vortex assisted liquid liquid microextraction of inorganic mercury in environmental waters prior to cold vapor atomic fluorescence spectroscopic detection.

    Science.gov (United States)

    Amde, Meseret; Liu, Jing-Fu; Tan, Zhi-Qiang; Bekana, Deribachew

    2016-03-01

    Zinc oxide nanofluid (ZnO-NF) based vortex assisted liquid liquid microextraction (ZnO-NF VA-LLME) was developed and employed in extraction of inorganic mercury (Hg(2+)) in environmental water samples, followed by cold vapor atomic fluorescence spectrometry (CV-AFS). Unlike other dispersive liquid liquid microextraction techniques, ZnO-NF VA-LLME is free of volatile organic solvents and dispersive solvent consumption. Analytical signals were obtained without back-extraction from the ZnO-NF phase prior to CV-AFS determination. Some essential parameters of the ZnO-NF VA-LLME and cold vapor generation such as composition and volume of the nanofluid, vortexing time, pH of the sample solution, amount of the chelating agent, ionic strength and matrix interferences have been studied. Under optimal conditions, efficient extraction of 1ng/mL of Hg(2+) in 10mL of sample solution was achieved using 50μL of ZnO-NF. The enrichment factor before dilution, detection limits and limits of quantification of the method were about 190, 0.019 and 0.064ng/mL, respectively. The intra and inter days relative standard deviations (n=8) were found to be 4.6% and 7.8%, respectively, at 1ng/mL spiking level. The accuracy of the current method was also evaluated by the analysis of certified reference materials, and the measured Hg(2+) concentration of GBW08603 (9.6ng/mL) and GBW(E)080392 (8.9ng/mL) agreed well with their certified value (10ng/mL). The method was applied to the analysis of Hg(2+) in effluent, influent, lake and river water samples, with recoveries in the range of 79.8-92.8% and 83.6-106.1% at 1ng/mL and 5ng/mL spiking levels, respectively. Overall, ZnO-NF VA-LLME is fast, simple, cost-effective and environmentally friendly and it can be employed for efficient enrichment of the analyte from various water samples. PMID:26717850

  6. Study of the disulfide reduction of denatured proteins by liquid chromatography coupled with on-line cold-vapor-generation atomic-fluorescence spectrometry (LC-CVGAFS).

    Science.gov (United States)

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

    2004-09-01

    Hydrophobic-interaction chromatography coupled on-line with chemical-vapor-generation atomic-fluorescence spectrometry (HIC-CVGAFS), optimized recently for the analysis of thiol-containing proteins under denaturing conditions, has been used to study the chemical reduction of denatured proteins. Four proteins chosen as models (human serum albumin (HSA), bovine serum albumin (BSA), alpha-lactalbumin (alpha-Lac) from bovine milk, and lysozyme from chicken egg (Lys)) were denatured with urea and reduced with dithiothreitol (DTT), with selenol as catalyst. The method is based on derivatization of the -SH groups of proteins with p-hydroxymercurybenzoate (PHMB), followed by HIC separation and post-column on-line reaction of the derivatized reduced, denatured proteins with bromine generated in situ. HgII, derived from rapid conversion of uncomplexed and protein-complexed PHMB, is selectively detected by AFS in an Ar/H2 miniaturized flame after sodium borohydride (NaBH4) reduction to Hg degrees . The yield of the reduction was studied as a function of reductant concentration, reduction time (tred), and urea concentration. Results showed that the optimum values for DTT and selenol concentrations and for tred were between 1 and 100 mmol L(-1) and between 1 and 20 min, respectively, depending on the protein studied. The percentage disulfide bond reduction increases as the urea concentration used for protein denaturation increases, giving a single-step sigmoid increment for single-domain, low-MW proteins (alpha-Lac and Lys), and a two-step sigmoid increment for multi-domain, high MW proteins (HSA and BSA). The shapes of plots of percentage reduced disulfide against urea concentration are characteristic of each protein and are correlated with the location of S-S in the protein. Under the adopted conditions complete protein denaturation is the conditio sine qua non for obtaining 100% S-S reduction. The detection limit for denatured, reduced proteins examined under the optimized

  7. 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.

  8. Efficient generation of volatile species for cadmium analysis in seafood and rice samples by a modified chemical vapor generation system coupled with atomic fluorescence spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xin-an, E-mail: 13087641@qq.com; Chi, Miao-bin, E-mail: 1161306667@qq.com; Wang, Qing-qing, E-mail: wangqq8812@163.com; Zhang, Wang-bing, E-mail: ahutwbzh@163.com

    2015-04-15

    Highlights: • We develop a modified chemical vapor generation method coupled with AFS for the determination of cadmium. • The response of Cd could be increased at least four-fold compared to conventional thiourea and Co(II) system. • A simple mixing sequences experiment is designed to study the reaction mechanism. • The interference of transition metal ions can be easily eliminated by adding DDTC. • The method is successfully applied in seafood samples and rice samples. - Abstract: A vapor generation procedure to determine Cd by atomic fluorescence spectrometry (AFS) has been established. Volatile species of Cd are generated by following reaction of acidified sample containing Fe(II) and L-cysteine (Cys) with sodium tetrahydroborate (NaBH{sub 4}). The presence of 5 mg L{sup −1} Fe(II) and 0.05% m/v Cys improves the efficiency of Cd vapor generation substantially about four-fold compared with conventional thiourea and Co(II) system. Three experiments with different mixing sequences and reaction times are designed to study the reaction mechanism. The results document that the stability of Cd(II)–Cys complexes is better than Cys–THB complexes (THB means NaBH{sub 4}) while the Cys–THB complexes have more contribution to improve the Cd vapor generation efficiency than Cd(II)–Cys complexes. Meanwhile, the adding of Fe(II) can catalyze the Cd vapor generation. Under the optimized conditions, the detection limit of Cd is 0.012 μg L{sup −1}; relative standard deviations vary between 0.8% and 5.5% for replicate measurements of the standard solution. In the presence of 0.01% DDTC, Cu(II), Pb(II) and Zn(II) have no significant influence up to 5 mg L{sup −1}, 10 mg L{sup −1}and 10 mg L{sup −1}, respectively. The accuracy of the method is verified through analysis of the certificated reference materials and the proposed method has been applied in the determination of Cd in seafood and rice samples.

  9. 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

  10. Efficient generation of volatile species for cadmium analysis in seafood and rice samples by a modified chemical vapor generation system coupled with atomic fluorescence spectrometry

    International Nuclear Information System (INIS)

    Highlights: • We develop a modified chemical vapor generation method coupled with AFS for the determination of cadmium. • The response of Cd could be increased at least four-fold compared to conventional thiourea and Co(II) system. • A simple mixing sequences experiment is designed to study the reaction mechanism. • The interference of transition metal ions can be easily eliminated by adding DDTC. • The method is successfully applied in seafood samples and rice samples. - Abstract: A vapor generation procedure to determine Cd by atomic fluorescence spectrometry (AFS) has been established. Volatile species of Cd are generated by following reaction of acidified sample containing Fe(II) and L-cysteine (Cys) with sodium tetrahydroborate (NaBH4). The presence of 5 mg L−1 Fe(II) and 0.05% m/v Cys improves the efficiency of Cd vapor generation substantially about four-fold compared with conventional thiourea and Co(II) system. Three experiments with different mixing sequences and reaction times are designed to study the reaction mechanism. The results document that the stability of Cd(II)–Cys complexes is better than Cys–THB complexes (THB means NaBH4) while the Cys–THB complexes have more contribution to improve the Cd vapor generation efficiency than Cd(II)–Cys complexes. Meanwhile, the adding of Fe(II) can catalyze the Cd vapor generation. Under the optimized conditions, the detection limit of Cd is 0.012 μg L−1; relative standard deviations vary between 0.8% and 5.5% for replicate measurements of the standard solution. In the presence of 0.01% DDTC, Cu(II), Pb(II) and Zn(II) have no significant influence up to 5 mg L−1, 10 mg L−1and 10 mg L−1, respectively. The accuracy of the method is verified through analysis of the certificated reference materials and the proposed method has been applied in the determination of Cd in seafood and rice samples

  11. Investigation of Al{sub 2}O{sub 3} barrier film properties made by atomic layer deposition onto fluorescent tris-(8-hydroxyquinoline) aluminium molecular films

    Energy Technology Data Exchange (ETDEWEB)

    Maindron, Tony; Aventurier, Bernard [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Ghazouani, Ahlem; Jullien, Tony [LETI/DTSI/SDEP/Laboratoire Dépôt Equipe 2, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Rochat, Névine [LETI/DTSI/Service de Caractérisation des Matériaux et Composants, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Simon, Jean-Yves; Viasnoff, Emilie [LETI/DOPT/SCOOP/Laboratoire des Composants pour la Visualisation, CEA-LETI, MINATEC Campus, 17 rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2013-12-02

    Al{sub 2}O{sub 3} films have been deposited at 85 °C by atomic layer deposition onto single 100 nm thick tris-(8-hydroxyquinoline) aluminium (AlQ{sub 3}) films made onto silicon wafers. It has been found that a thick ALD-deposited Al{sub 2}O{sub 3} layer (> 11 nm) greatly prevents the photo-oxidation of AlQ{sub 3} films when exposed to continuous UV irradiation (350 mW/cm{sup 2}). Thin Al{sub 2}O{sub 3} thicknesses (< 11 nm) on the contrary yield lower barrier performances. Defects in the Al{sub 2}O{sub 3} layer have been easily observed as non-fluorescent AlQ{sub 3} singularities, or black spots, under UV light on the system Si/AlQ{sub 3}/Al{sub 2}O{sub 3} stored into laboratory conditions (22 °C/50% Relative Humidity (RH)) for long time scale (∼ 2000 h). Accelerated aging conditions in a climatic chamber (85 °C/85% RH) also allow faster visualization of the same defects (168 h). The black spot density grows upon time and the black spot density occurrence rates have been calculated to be 0.024 h{sup −1}·cm{sup −2} and 0.243 h{sup −1}·cm{sup −2} respectively for the two testing conditions. A detailed investigation of these defects did show that they cannot be ascribed to the presence of a detectable particle. In that sense they are presumably the consequence of the existence of nanometre-scaled defects which cannot be detected onto fresh samples. Interestingly, an additional overcoating of ebeam-deposited SiO{sub 2} onto the Si/AlQ{sub 3}/Al{sub 2}O{sub 3} sample helps to decrease drastically the black spot density occurrence rates down to 0.004 h{sup −1}·cm{sup −2} and 0.04 h{sup −1}·cm{sup −2} respectively for 22 °C/50% RH and 85 °C/85% RH testing conditions. These observations highlight the moisture sensitivity of low temperature ALD-deposited Al{sub 2}O{sub 3} films and confirm the general idea that a single Al{sub 2}O{sub 3} ALD film performs as an ultra-high barrier but needs to be overprotected from water condensation by an

  12. Fluorescence responses and photosynthetic rates of sunlit and shaded leaves of Italian alpine forest species: Summer 1997 ATOM-LIFT campaign

    Science.gov (United States)

    Kim, Moon S.; Cecchi, Giovanna; Chappelle, Emmett W.; Bazzani, Marco; McMurtrey, James E., III; Corp, Lawrence A.; Sandu, R.; Tirelli, Daniele

    1998-07-01

    Terrestrial vegetation studies were carried out in the Italian Northeastern Alps in Val Visdende. The measurement site was 15 Kilometers Northeast of the town of St. Stefano di Calore (Belluno), Italy. Measurements were acquired on a wooded site at the Italian Department of Forestry Station on species native to the Italian Alps. The species included spruce (Picea abies) and alder (Alnus incana) trees. Characterization was also made of the fluorescence responses of several under-story species such as Dactylorhiza fuchsii of the Orchidaceae family, Caltha palustris and Ranunculus ficaria of the Ranuncolcee family, and Trifolium pratense and Trifolium repens of the Leguminosae family. Terrestrial vegetation monitoring was conducted with the Italian FLIDAR remote sensing instrument mounted in a mobile van, the NASA/USDA Fluorescence Imaging System (FIS), and the Spectron SE-590 for optical properties. Photosynthetic CO2 gas exchange rates we made with LI-COR 6400 infrared gas analyzer. Pigments from the samples were extracted and analyzed with a Perkin Elmer Lamda 7 Spectrometer to determine pigment concentrations. Fluorescence responses were collected from vegetation samples grown under different ambient light regimes of sun-lit versus shaded. The vegetation showed different fluorescence characteristics. A fluorescence algorithm, (F740/F680)/F550, and rate of photosynthesis showed a strong linear relationship.

  13. Methodology using a portable X-ray fluorescence device for on-site and rapid evaluation of heavy-atom contamination in wounds: a model study for application to plutonium contamination.

    Directory of Open Access Journals (Sweden)

    Hiroshi Yoshii

    Full Text Available Workers decommissioning the Fukushima-Daiichi nuclear power plant damaged from the Great East Japan Earthquake and resulting tsunami are at risk of injury with possible contamination from radioactive heavy atoms including actinides, such as plutonium. We propose a new methodology for on-site and rapid evaluation of heavy-atom contamination in wounds using a portable X-ray fluorescence (XRF device. In the present study, stable lead was used as the model contaminant substitute for radioactive heavy atoms. First, the wound model was developed by placing a liquid blood phantom on an epoxy resin wound phantom contaminated with lead. Next, the correlation between the concentration of contaminant and the XRF peak intensity was formulated considering the thickness of blood exiting the wound. Methods to determine the minimum detection limit (MDL of contaminants at any maximal equivalent dose to the wound by XRF measurement were also established. For example, in this system, at a maximal equivalent dose of 16.5 mSv to the wound and blood thickness of 0.5 mm, the MDL value for lead was 1.2 ppm (3.1 nmol. The radioactivity of 239Pu corresponding to 3.1 nmol is 1.7 kBq, which is lower than the radioactivity of 239Pu contaminating puncture wounds in previous severe accidents. In conclusion, the established methodology could be beneficial for future development of a method to evaluate plutonium contamination in wounds. Highlights: Methodology for evaluation of heavy-atom contamination in a wound was established. A portable X-ray fluorescence device enables on-site, rapid and direct evaluation. This method is expected to be used for evaluation of plutonium contamination in wounds.

  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

    We present here a new analytical strategy for identification and characterisation of fluorescent proteins from marine organisms. By applying basic proteomics tools it is possible to screen large sample collections for fluorescent proteins of desired characteristics prior to gene cloning. Our...... methodology which includes isolation, spectral characterisation, stability testing, gel-based separation and mass spectrometric identification was optimised on samples collected during the Danish Galathea 3 expedition. Four corals of the Fungia, Sarcophyton and Acropora species emitting green fluorescence...... were tested. Each of the fluorescent extracts behaves differently under denaturing conditions but complete fluorescence loss was not observed. Optimised electrophoretic conditions yielded effective separation of active fluorescent proteins in both 1DE and 2DE. Mass spectrometric analysis...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    We present here a new analytical strategy for identification and characterisation of fluorescent proteins from marine organisms. By applying basic proteomics tools it is possible to screen large sample collections for fluorescent proteins of desired characteristics prior to gene cloning. Our...... methodology which includes isolation, spectral characterisation, stability testing, gel-based separation and mass spectrometric identification was optimised on samples collected during the Danish Galathea 3 expedition. Four corals of the Fungia, Sarcophyton and Acropora species emitting green fluorescence...... were tested. Each of the fluorescent extracts behaves differently under denaturing conditions but complete fluorescence loss was not observed. Optimised electrophoretic conditions yielded effective separation of active fluorescent proteins in both 1DE and 2DE. Mass spectrometric analysis of the...

  16. Determination of Mercury, Lead and Arsenic in Mainstream Smoke of Cigarette by Atomic Fluorescence Spectroscopy%原子荧光法测定卷烟主流烟气中的汞·砷·铅

    Institute of Scientific and Technical Information of China (English)

    孔维松; 汤丹俞; 曾晓鹰; 者为; 施红林; 张峻松

    2009-01-01

    A new method for the determination of mercury, lead and arsenic in cigarette smoke by using atomic fluorescence spectroscopy was studied.The mainstream cigarette smoke was collected by cambridge filter, and mercury, lead and arsenic were collected with 2% hydrochloric acid ultrasonic leaching filter.The mercury, lead and arsenic in digest were determined by atomic fluorescence spectroscopy.Under the optimum determination conditions, the standard relative standard deviations are 2.8%-3.2% and the recoveries are 91%-95%.%研究了用原子荧光法测定卷烟主流烟气中的汞、砷、铅.结果表明,卷烟主流烟气用剑桥滤片捕集,用2%盐酸超声波浸取滤片上捕集的汞、砷、铅,然后用原子荧光法测定,方法相对标准偏差为2.8%~3.2%,标准回收率为91%~95%.

  17. Pretreatment of oily samples for analysis by flow injection-spectrometric methods.

    Science.gov (United States)

    Burguera, José Luis; Burguera, Marcela

    2011-01-15

    This review presents a critical discussion of selected reports dealing with the pretreatment methods of oily samples and the determination of their organic and inorganic constituents using flow systems and spectrometric methods. Special emphasis is given to the on-line couplings with detection systems based on UV-visible spectrophotometry and spectrofluorimetry, atomic absorption spectrometry either with flame or electrothermal atomization as well as inductively coupled plasma optical emission spectrometry or inductively coupled plasma-mass spectrometry. Simple dilution with organic solvents, digestion with concentrated acids under thermal heating, microwave or ultrasound radiation and emulsification procedures are mostly used. The empirical preparation of certain organized assemblies like micelles, emulsions and specially microemulsions added to the confusion of some of the terms, demand a brief description of their characteristics, the correct formulation and some of their applications to the manipulation and treatment of oily samples. The analytical capabilities of combining flow manifolds with spectrometric methods for the determination of specific parameters in oily samples apparently have not been sufficiently exploited yet. PMID:21147308

  18. Determination of Arsenic, Mercury and Barium in herbarium mount paper using dynamic ultrasound-assisted extraction prior to atomic fluorescence and absorption spectrometry

    OpenAIRE

    Lummas, S.; Ruiz-Jimenez, J.; Luque de Castro, M.D.; Colston, Belinda; Gonzalez-Rodriguez, Jose; B. Chen; W. Corns

    2011-01-01

    A dynamic ultrasound-assisted extraction method using Atomic Absorption and Atomic Flourescence spectrometers as detectors was developed to analyse mercury, arsenic and barium from herbarium mount paper originating from the herbarium collection of the National Museum of Wales. The variables influencing extraction were optimised by a multivariate approach. The optimal conditions were found to be 1% HNO3 extractant solution used at a flow rate of 1 mL min-1. The duty cycle and amplitude of the ...

  19. 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)

  20. 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.

  1. Analysis of the near-resonant fluorescence spectra of a single rubidium atom localized in a three-dimensional optical lattice

    CERN Document Server

    Kim, Wookrae; Kim, Jung-Ryul; Lee, Yea-Lee; Ihm, Jisoon; An, Kyungwon

    2010-01-01

    Supplementary information is presented on the recent work by W. Kim et al. on the matter-wave-tunneling-induced broadening in the near-resonant spectra of a single rubidium atom localized in a three-dimensional optical lattice in a strong Lamb-Dicke regime.

  2. Study on laser atomic spectroscopy

    International Nuclear Information System (INIS)

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

  3. Multisyringe flow injection lab-on-valve systems coupled to hydride generation atomic fluorescence spectrometry for on-line bead-injection preconcentration and determination of total inorganic arsenic in environmental waters

    DEFF Research Database (Denmark)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald;

    and 10% KI. The eluate merges downstream with a defined plug of sodium tetrahydroborate (0.3% w/v) for generation of arsine, which is subsequently quantified by AFS. An oxidation agent, namely 2x10-6 M potassium permanganate, was employed for the quantitative oxidation of As(III) to As(V) in the samples......In this work, the third generation of flow injection analysis, that is, the so-called micro-Lab-on-Valve (LOV) approach, is hyphenated for the first time to atomic fluorescence spectrometry (AFS) for the separation, preconcentration and monitoring of hydride forming elements. A multisyringe flowing...... stream network is assembled for accurate handling of solutions and on-line post column derivatization of the eluate for the generation of the volatile species. The potential of the new hyphenated technique for environmental assays was ascertained via the determination of ultratrace levels of total...

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

    International Nuclear Information System (INIS)

    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. - 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

  5. Determination of trace mercury in surface water by atomic fluorescence spectrometry%原子荧光光度法测定地表水中的痕量汞

    Institute of Scientific and Technical Information of China (English)

    潘腊青; 章维维; 池怡; 周姗

    2013-01-01

    以硫酸-高锰酸钾加热消解水样,低浓度硼氢化钾作为还原剂,运用 A FS -9230双道原子荧光光度计,采用顺序注射-冷蒸气发生-原子荧光光谱法,测定地表水中的痕量汞。检出限为0.012μg/L ,回收率为90%~110%,RSD小于10.0%,该法具有灵敏度高,精密度好,干扰少和操作简单方便等优点,同时对方法的质量控制进行了探讨。%Heating and digestion of water samples by sulfuric acid and potassium permanganate ,low concentration potassium borohydride as the reducing agent ,using AFS-9230 double-channel atomic fluo-rescence spectrometry ,determination of trace mercury in surface water with sequential injection-cold vapor generation-atomic fluorescence spectrometry was carried out. The detection limit is 0.012μg/L ,the rate of recovery is 90%-110% ,RSD<10.0%. The advantages of the method are of high sensitivity ,good preci-sion ,less interference ,simple and convenient operation. At the same time ,the aspect of quality control w as discussed.

  6. The method for evaluation of irradiated fuel performance based on Gamma - Spectrometric analysis of fission products

    International Nuclear Information System (INIS)

    One of the main aims of International Atomic Energy Agency (IAEA) activities is safeguards control related to the nuclear weapons nonproliferation treaty. To solve this problem, IAEA performs the control of nuclear reactors operation regimes independent of the operator's data. In cases where direct control is impossible, the control of reactor operation regimes may be carried out indirectly by means of spent-fuel parameter investigation. Such spent-fuel parameters as the contents of nuclides 235U, 239Pu, initial fuel enrichment, decay cooling time, and average neutron flux are able to characterize the reactor operation regime. Evaluation of the aforementioned parameters may be carried out utilizing gamma-spectrometric analysis of fission products. Existing methods of gamma-spectrometric data interpretation require information about irradiation history and cooling time after fuel withdrawal. For a research reactor, this information may be incorrect or falsified by the reactor operator; therefore, application of these methods for control of reactor operation regimes is not quite correct. This paper describes a method for spent-fuel parameter evaluation that is based only on utilization of experimental information on ratios of fission product concentrations without data on irradiation history and cooling time

  7. Fluorescent silk cocoon creating fluorescent diatom using a “Water glass-fluorophore ferry”

    Science.gov (United States)

    Kusurkar, Tejas S.; Tandon, Ishita; Sethy, Niroj Kumar; Bhargava, Kalpana; Sarkar, Sabyasachi; Singh, Sushil Kumar; Das, Mainak

    2013-11-01

    Fluorophores are ubiquitous in nature. Naturally occurring fluorophores are exceptionally stable and have high quantum yield. Several natural systems have acquired fluorescent signature due to the presence of these fluorophores. Systematic attempt to harvest these fluorophores from natural systems could reap rich commercial benefit to bio-imaging industry. Silk cocoon biomaterial is one such example of natural system, which has acquired a fluorescent signature. The objective of this study is to develop simple, rapid, commercially viable technique to isolate silk cocoon membrane fluorophores and exploring the possibility of using them as fluorescent dye in bio-imaging. Here, we report an innovative water glass (Na2SiO3) based strategy to isolate the silk cocoon fluorophores. Isolated fluorophore is majorly quercetin derivatives and exhibited remarkable photo- and heat stability. Fluorescence and mass spectrometric analysis confirmed presence of a quercetin derivative. We further used this fluorophore to successfully label the silicate shell of diatom species Nitzschia palea.

  8. Mass Spectrometric Immunoassays in Characterization of Clinically Significant Proteoforms

    Directory of Open Access Journals (Sweden)

    Olgica Trenchevska

    2016-03-01

    Full Text Available Proteins can exist as multiple proteoforms in vivo, as a result of alternative splicing and single-nucleotide polymorphisms (SNPs, as well as posttranslational processing. To address their clinical significance in a context of diagnostic information, proteoforms require a more in-depth analysis. Mass spectrometric immunoassays (MSIA have been devised for studying structural diversity in human proteins. MSIA enables protein profiling in a simple and high-throughput manner, by combining the selectivity of targeted immunoassays, with the specificity of mass spectrometric detection. MSIA has been used for qualitative and quantitative analysis of single and multiple proteoforms, distinguishing between normal fluctuations and changes related to clinical conditions. This mini review offers an overview of the development and application of mass spectrometric immunoassays for clinical and population proteomics studies. Provided are examples of some recent developments, and also discussed are the trends and challenges in mass spectrometry-based immunoassays for the next-phase of clinical applications.

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

    International Nuclear Information System (INIS)

    A comparison of trace element determinations of low atomic number (Z) elements Na, Mg, Al, P, K and Ca in air, helium and vacuum atmospheres using W Lβ1, Mo Kα and Cr Kα excitations has been made. For Mo Kα and W Lβ1 excitations a Si (Li) detector with beryllium window was used and measurements were performed in air and helium atmospheres. For Cr Kα excitation, a Si (Li) detector with an ultra thin polymer window (UTW) was used and measurements were made in vacuum and air atmospheres. The sensitivities of the elemental X-ray lines were determined using TXRF spectra of standard solutions and processing them by IAEA QXAS program. The elemental concentrations of the elements in other solutions were determined using their TXRF spectra and pre-determined sensitivity values. The study suggests that, using the above experimental set up, Mo Kα excitation is not suited for trace determination of low atomic number element. Excitation by WLβ1 and helium atmosphere, the spectrometer can be used for the determination of elements with Z = 15 (P) and above with fairly good detection limits whereas Cr Kα excitation with ultra thin polymer window and vacuum atmosphere is good for the elements having Z = 11 (Na) and above. The detection limits using this set up vary from 7048 pg for Na to 83 pg for Ti. - Highlights: • TXRF conditions are optimized for low atomic number (Z) element determinations. • Mo Kα with Be window detector can be used for elements with Z ≥ 20 (K). • W Lβ1 with Be window detector can be used for elements with Z ≥ 15 (P). • Cr Kα, UTW detector and vacuum atmosphere are suitable for elements with Z ≥ 11 (Na). • For the elements with Z ≥ 11 (Na), a separate study is needed

  10. Atomic data from the Iron Project.XLIV. Transition probabilities and line ratios for Fe VI with fluorescent excitation in planetary nebulae

    OpenAIRE

    Chen, Guo Xin; Pradhan, Anil K.

    2000-01-01

    Relativistic atomic structure calculations for electric dipole E1, electric quadrupole E2 and magnetic dipole M1 transition probabilities among the first 80 fine-structure levels of Fe VI, dominated by configurations 3d^3, 3d^24s, and 3d^24p, are carried out using the Breit-Pauli version of the code Superstructure. Experimental energies are used to improve the accuracy of these transition probabilities. Employing the 80-level collision-radiative (CR) model with these dipole and forbidden tran...

  11. THE ATOMIC WEIGHTS COMMISSION AND ISOTOPIC ABUNDANCE RATIO DETERMINATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, N.E.

    2005-08-07

    Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric measurements and only 38% in the first half century. It might be noted that two chemical elements (tellurium and mercury) are still based on chemical measurements, where the atomic weight value calculated from the relative isotopic abundance measurement either agrees with the value from the chemical measurement or the atomic weight value calculated from the relative isotopic abundance measurement falls within the uncertainty of the chemical measurement of the atomic weight. Of the 19 chemical elements, whose atomic weight is based on non-corrected relative isotopic abundance measurements, five of these are two isotope systems (indium, iridium, lanthanum, lutetium and tantalum) and one is a three-isotope system (oxygen).

  12. Aeromagnetic and gamma spectrometric interpretation of the Riacho Queimadas sheet

    International Nuclear Information System (INIS)

    This paper presents the aeromagnetic and gamma-spectrometric interpretation of the Riacho Queimadas Sheet (SC.24-V-A-I), southeastern Piaui State, Brazil, originated from studies as part of the Programa Levantamentos Geologicos Basicos do Brasil-PLGB (basic Geological Surveying Program of Brazil). The interpretation of magnetometric and gamma-spectrometric maps identified mafic-ultramafic and felsic terrains and sedimentary rocks and the utilization of modelling techniques defined the shape and variation in thickness of geologic bodies. It was possible to limit young igneous intrusive rocks and to suggest the hierarchy of structural alignments and shear zones, based on anomalies shape analyses. (author)

  13. Mass spectrometric methods for studying nutrient mineral and trace element absorption and metabolism in humans using stable isotopes: a review

    International Nuclear Information System (INIS)

    Mass spectrometric methods for determining stable isotopes of nutrient minerals and trace elements in human metabolic studies are described and discussed. The advantages and disadvantages of the techniques of electron ionization, fast atom bombardment, thermal ionization, and inductively coupled plasma and gas chromatography mass spectrometry are evaluated with reference to their accuracy, precision, sensitivity, and convenience, and the demands of human nutrition research. Examples of specific applications are described and the significance of current developments in mass spectrometry are discussed with reference to present and probable future research needs. (Author)

  14. Determination of the electromagnetic dipole strength distribution in medium-heavy atomic nuclei by means of nuclear resonance fluorescence; Bestimmung der elektromagnetischen Dipolstaerkeverteilung in mittelschweren Atomkernen mittels Kernresonanzfluoreszenz

    Energy Technology Data Exchange (ETDEWEB)

    Massarczyk, Ralph Jens

    2011-01-17

    During the last hundred years several models were developed to describe the configuration of nuclei. These models have to make predictions, which should be comparable with experiments. As a standard type of experiment the nuclear resonance fluorescence was established. A nucleus is excited by irradiation with photons. By emitting one or more photons the nucleus decays back to the ground state. With this method it is possible to measure energy levels and to determine the strength of their excitation. A continuum of unresolved peaks gives additional strength. The existing setup at the linear electron accelerator ELBE of the Forschungszentrum Dresden-Rossendorf uses bremsstrahlung, produced as a secondary beam in a thin Niobium foil. During the years 2008/09 experiments on the nuclei of {sup 86}Kr and {sup 136}Ba took place there. In this work they will be analyzed. Photon flux and efficiency determination have been done as well as simulations on detector response and non-nuclear scattered background events. For this purpose the GEANT4 package was used. Finally the resulting cross sections were corrected for branching and feeding.

  15. Preparation and spectrometric identification of amide derivatives with antimalaric

    International Nuclear Information System (INIS)

    The structures of polymeric compounds using spectrometric analysis of infrared, ultraviolet and protonic magnetic resonance and 13C nuclear magnetic resonance are studied. Some structural models are used such as antimalaric-sulfones and pyrimidinic derivatives, and non-polymeric derivatives of active compounds. A comparative analysis on structures less complexes is shown. (M.J.C.). Spectrums 186 p

  16. Recent advances in mass spectrometric applications in hydrology

    International Nuclear Information System (INIS)

    The recent advances in mass spectrometric applications in hydrology include 18O of nitrates and sulphates, 37Cl of chlorides for studying origin of groundwater pollution, 3He/4He for geothermal fluids and analysis, 14C, 36Cl and 129I for dating groundwater by Accelerator Mass Spectrometry (AMS)

  17. Gamma-spectrometric definition of natural radionuclide content in soil

    International Nuclear Information System (INIS)

    The method of gamma-spectrometric definition if natural radionuclide content in soil is proposed that takes into account the loosened contribution of natural background constituent in measured spectra. The radioactivity of some territories of Uzbekistan is investigated by the present method. (author)

  18. J Fluorescence

    OpenAIRE

    Resch-Genger, U.; Hoffmann, K.; Nietfeld, W; A. Engel; Neukammer, J.; Nitschke, R.; Ebert, P.; Macdonald, R

    2005-01-01

    The scope of this paper is to illustrate the need for an improved quality assurance in fluorometry. For this purpose, instrumental sources of error and their influences on the reliability and comparability of fluorescence data are highlighted for frequently used photoluminescence techniques ranging from conventional macro- and microfluorometry over fluorescence microscopy and flow cytometry to microarray technology as well as in vivo fluorescence imaging. Particularly, the need for and requir...

  19. Determination of actinides by alpha spectrometric methods

    International Nuclear Information System (INIS)

    attributes of mass activities of radionuclides in oyster mushroom's sporocarps compared to their sub-base. We used two methods to separate the monitored radionuclides in a radiochemical analyse. The first of them was an extraction fluid - fluid with Aliquat-336 to separate Pu and TOPO to separate Am. The second method was a proceeding modified by us and utilizing principles of an extraction chromatography with TRU Resin and DGA Resin sorbents made by Eichrom Company. An effectivity and a suitability of both applied methods were monitored following the attributes of radiochemical extractions used in tracer's radionuclides 242Pu a 243Am in this particular type of environmental samples. The reliability of the modified methodology, in accordance to selected criteria for validation of analytical method, was proved by comparison of both above mentioned methods. material delivered from IAEA, which presented a soil sample with code identification Soil IAEA-375. The obtained values of mass activities of 239+240Pu, 239Pu and 241Am used in reference material, demonstrated a conformity with IAEA values, whereby we fulfilled one of the significant conditions of validate process. At the end of this thesis we applied the modified method of extraction chromatography with UTEVA Resin sorbent to define mass activities of uranium on soil and water samples where we monitored attributes of radiochemical extractions of 232U tracer's radionuclide as the criteria of utilizability. The reliability of our modified method was verified by participation in international interlaboratory comparative proficiency tests and our results were in accordance with results of the reference laboratory. It means also a fulfilment of notable standard of the validate process. The results of all realized experimentations of radionuclides separation whether by extraction fluid - fluid or by extraction chromatography were determined by alpha-spectrometric measurements. (author)

  20. 工作场所空气中锡的氢化物发生-原子荧光光谱测定法%Determination of Tin in the air by hydride generation-atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    陈峰; 谢超

    2012-01-01

    [Objective] To study the method for determination of tin in workplace air by hydride generation-atomic fluorescence spectrometry. [Methods]The electric hot plate was chosen to digest membrane, with aqua regia as digestive juice. Appropriate instrument conditions were chosen for detection. [Results]The calibration curve was linear in the range of 0-100 μg/L {R =0.999 7). The RSD of standard solution with different concentration was 0.82% -3.87 % , the recoveries were 98.0% -102.7% , and the detection limit was 0.090 μg/ml. [ Conclusion] Hydride generation - atomic fluorescence spectrometry has characteristics of high sensitivity, less interference, selectivity, accuracy, etc. And to do it with aqua regia digestion are appropriate fordetennination of tin in various workplaces.%目的 研究氢化物发生一原子荧光光谱法测定工作场所空气中的锡.方法 电热板消化采样滤膜,选择用王水做消化液消解,选择适宜的仪器工作条件进行检测.结果 在0 ~ 100 μg/L线性范围内,相关系数为0.9997,不同浓度标准溶液的相对标准偏差在0.82%~3.87%之间,加标回收率在98.0%一102.7%之间,方法检出限为0.090 μg/ml.结论 氢化物发生一原子荧光光谱法具有灵敏度高、干扰少、选择性好、准确度高等优点,而用王水做消化液适用于各种作业场所中锡的测定.

  1. Study of high efficiency excited helium atom beam production for electric field measurements with high spatial and temporal resolution by laser-induced fluorescence method. JAERI's nuclear research promotion program, H13-013 (Contract research)

    International Nuclear Information System (INIS)

    The objective of this study is to develop a highly efficient method in producing a pulsed supersonic beam of 21S metastable He atoms for the laser induced fluorescence (LIF) diagnostics making use of the Stark effects in forbidden transition of HeI, in order to apply the LIF method to measurements of localized electric fields in a deuterium plasma in an Inertial Electrostatic Confinement (IEC) fusion neutron/proton source. Firstly, we studied numerically the dependence of excitation efficiency on electron temperature and density in a plasma exciter, and found that an efficiency of several times of 10-4 is achievable, which is very encouraging in comparison with the typical efficiency limit of 10-6 by conventional methods. We then investigated a couple of schemes for producing sufficiently dense plasma under an extremely low gas pressure condition in the experiments. As a result, we could have developed successfully a compact magnetron-discharge-based system which can produce a race-track-shaped plasma capable of strong interaction with the injected supersonic beam atoms. Also, we have designed and fabricated an injector of pulsed supersonic He beam, and its performance characteristics were studied. It is found that well collimated beams can be produced with a high repetition rate (> 1 Hz) as expected. The achieved on-axis density is found to be above 1/10 of the target density of 1013 cm-3 initially envisaged for the LIF diagnostics. Further enhanced density is found achievable through the optimization of the configuration. (author)

  2. Speciation analysis of mercury in sediments using ionic-liquid-based vortex-assisted liquid-liquid microextraction combined with high-performance liquid chromatography and cold vapor atomic fluorescence spectrometry.

    Science.gov (United States)

    Leng, Geng; Chen, Wenjin; Wang, Yong

    2015-08-01

    An improved novel method based on ionic liquid vortex-assisted liquid-liquid microextraction has been developed for the extraction of methylmercury, ethylmercury and inorganic mercury in sediment samples prior to analysis by high-performance liquid chromatography with cold vapor atomic fluorescence spectrometry. In this work, mercury species were firstly complexed with dithizone, and the complexes were extracted into 1-hexyl-3-methylimidazolium hexafluorophosphate. Key factors that affect the extraction efficiency of mercury species, such as type and amount of ionic liquid and chelatants, extraction time, sample pH, salt effect and matrix effect were investigated. Under the optimum conditions, linearity was found in the concentration range from 0.1-70 ng/g. Limits of detection ranged from 0.037-0.061 ng/g. Reproducibility and recoveries were assessed by extracting a series of six independent sediment samples that were spiked with different concentration levels. Finally, the proposed method was successfully applied in analysis of real sediment samples. In this work, ionic liquids vortex-assisted liquid-liquid microextraction was for the first time used for the extraction of mercury species in sediment samples. The proposed method was proved to be much simpler and more rapid, as well as more environmentally friendly and efficient compared with the previous methods. PMID:25998155

  3. 原子荧光光谱法测定水中砷的方法比对试验%Comparative Test of Arsenic Determination in Water by Using Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    刘清明

    2011-01-01

    Experimental analysis identifies the conditions of atomic fluorescence spectrometry to determine arsenic in water sam- pie, and performs comparative tests of this method under the optiminum conditions, and the current national standards analysis method GB7485 -87. Results indicates that this method is easy to operate, which can greatly improve the detection efficiency and completely replace current complex national standard analysis operation method.%通过试验分析确定了原子荧光光谱法测定水样中砷的检测条件,并在优化试验条件下与现行砷的国家标准分析方法GB 7485-87进行了样品分析比对实验,试验表明,该方法操作简单方便,历时短,可大大提高检测效率,完全可以代替分析操作复杂繁琐的现行国家标准分析方法。

  4. 液相色谱-原子荧光联用法测定鱼油中的甲基汞%Determination of methylmercury in fish oil by interface technique coupled high performance liquid chromatography with atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    徐君辉; 周向阳; 沈飚; 秦德元

    2011-01-01

    先后采用10% KOH+ 1%硫脲和20% HCl提取鱼油样品,用液相色谱-原子荧光联用技术测定样品中的甲基汞含量.试验结果表明,线性范围在0~ 10 μg/L之间,相关系数为0.999 3,检出限为0.2 μg/L,加标回收率在96.0%~105.0%之间,相对标准偏差小于5%.该方法快速、简便、准确.%Methylmercury was extracted from fish oil sample with 10% potassium hydroxide and 1% thio-urea, then with 20% hydrochloric acid, and then was determined by interface technique coupled high performance liquid chromatography with atomic fluorescence spectrometry. The results showed that the linear range was between 0 and 10 μg/L,the linear coefficient was 0.999 3 ,the detection limit was 0.2 μg/ L,recovery was between 96.0% and 105. 0% ,the relative standard was less than 5%. The method was rapid, simple, and accurate.

  5. Investigation of the Elemental Contents of Some Samples of Soil, Sediments and Fish from the Blue Nile and the White Nile Around Khartoum Using Atomic Absorption and X- Ray Fluorescence Spectrometry

    International Nuclear Information System (INIS)

    This work was performed to evaluate the environmental pollution at the Blue Nile (B.N) and the White Nile (W.N) around Khartoum state. Samples of soil, sediments ( > 63 μm size) and fish were collected from the studied area and analyzed. The concentrations of some elements (K, Ca, Ti, Mn, Fe, Cr, Co, Cu, Ni, Sr, Rb, Zn, Br, Y, Zr, and Pb) were determined using two analytical methods; atomic absorption (AAS) and X- ray fluorescence (XRF) spectrometry. The data was statistically analyzed to compare the results obtained by the two analytical methods. The results of most elements determined by the two methods were significantly similar. Generally, the elemental concentrations of sediments from the BN were higher than the WN. The extent of pollution was determined by calculating the enrichment factors. The enrichment factors in sediments were calculated using both Fe and Ti as reference elements and bulk soil composition as a reference material. Some elements were slightly enriched at some sites but not to a degree to indicate a serious pollution. The elemental concentrations in fish were not that high. We can conclude that the extent of pollution with heavy elements at the B.N and W.N around Khartoum State is not a serious environmental problem so far.(author)

  6. Investigation of the elemental contents of some samples of soil, sediments and fish from the Blue Nile and the White Nile around Khartoum using atomic absorption and x-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    This work was performed to evaluate the environmental pollution at the Blue Nile (B.N) and the White Nile (W.N) around Khartoum State. Samples of soil, sediments (> 63 μm size) and fish were collected from the studied area and analyzed. The concentrations of some elements (K, Ca, Ti, Mn, Fe, Cr, Co, Cu, Ni, Sr, Rb, Zn, Br, Y, Zr, and Pb) were determined using two analytical methods, atomic absorption (AAS) and x-ray fluorescence (XRF) spectrometry. The data was statistically analyzed to compare the results obtained by the two analytical methods. The results of most elements determined by the two methods were significantly similar. Generally, the elemental concentrations of sediments from the B.N were higher than the W N. The extent of pollution was determined by calculating the enrichment factors. The enrichment factors in sediments were calculated using both Fe and Ti as reference elements and bulk soil composition as a reference material. Some elements were slightly enriched at some sites but not to a degree to indicate a serious pollution. The elemental concentrations in fish were not that high. We can conclude that the extent of pollution with heavy elements at the B.N and W.N around Khartoum State is not a serious environmental problem so far. (Author)

  7. Determination of arsenic releases from glass infusion bottles of drug packaging materials by hydride generation-atomic fluorescence spectrometry%玻璃输液瓶中砷浸出量的原子荧光光谱法测定

    Institute of Scientific and Technical Information of China (English)

    周红娇

    2011-01-01

    目的:建立氢化物发生-原子荧光光谱法HG-AFS测定药包材中玻璃输液瓶的砷浸出量方法.方法:样品液直接用原子荧光光谱法测定,并对HG-AFS工作参数及条件进行优化和选择.结果:标准曲线线性良好,相关系数r=0.999 4,检出限0.064 μg/L,回收率为97.80%,RSD为2.04%.结论:原子荧光光谱法简便、快速准确、灵敏度高.%Objective: To establish a method for determination of arsenic release from Glass Infusion bottles of drug packaging materials by hydride generation-atomic fluorescence spectrometer (HG-AFS). Methods: Sample solutions were directly determined by HG-AFS. Operation parameters of HG-AFS and condition were optimized and selected. Results: A good linearity was obtained (r=0.999 4). The detection limit was 0.064 μg/L. The recovery was 97.80%. RSD was 2.04%.Conclusion: The HG-AFS method is simple and fast with high sensitivity.

  8. Inductively coupled plasma atomic spectrometry (ICP-AES) and associated tecgniques

    International Nuclear Information System (INIS)

    Plasma emission spectroscopy is now an established technique for the analysis and quality control of modern inorganic and polymeric materials. The detection limit of < mu g iota /sup -1/ achieved by ICP-MS and atomic fluorescence methods with multielement capability has led to the explosive growth of trends and methodologies in thousands of published articles. The major development has been in the evolution of powerful computer controlled instruments with advanced optics and highly sophisticated detection and data processing systems. The high resolution spectrometers developed by several companies have reduced the inter element and molecular interference relieving the analyst of tedious and time-consuming routines of matrix matching and spectral corrections. The cost of analysis per sample has been drastically reduced due to rapid and reliable results in a short time. However the costs of such systems remains high and require very clean environment for the installation and operation of modern high resolution instruments. Major applications of atomic spectrometric methods are in semiconductor and high purity industrial materials where the purchase of such expensive units can be justified. Applications in pharmaceutical, chemical and material sciences are also on the increase. Assessment of natural resources and environmental and toxic element studies are also justifying the social services provided by modern instrumental techniques. The trend of inter comparison is also growing due to the availability of large number of instruments / techniques. (author)

  9. A single-atom detector integrated on an atom chip: fabrication, characterization and application

    Science.gov (United States)

    Heine, D.; Rohringer, W.; Fischer, D.; Wilzbach, M.; Raub, T.; Loziczky, S.; Liu, XiYuan; Groth, S.; Hessmo, B.; Schmiedmayer, J.

    2010-09-01

    We describe a robust and reliable fluorescence detector for single atoms that is fully integrated on an atom chip. The detector allows spectrally and spatially selective detection of atoms, reaching a single-atom detection efficiency of 66%. It consists of a tapered lensed single-mode fiber for precise delivery of excitation light and a multi-mode fiber to collect the fluorescence. The fibers are mounted in lithographically defined holding structures on the atom chip. Neutral 87Rb atoms propagating freely in a magnetic guide are detected and the noise of their fluorescence emission is analyzed. The variance of the photon distribution allows us to determine the number of detected photons per atom and from there the atom detection efficiency. The second-order intensity correlation function of the fluorescence shows near-perfect photon anti-bunching and signs of damped Rabi oscillations. With simple improvements, one can increase the detection efficiency to 95%.

  10. Characterization of nuclear fuels by ICP mass-spectrometric techniques

    International Nuclear Information System (INIS)

    Isotopic analyses of radioactive materials such as irradiated nuclear fuel are of major importance for the optimization of the nuclear fuel cycle and for safeguard aspects. Among the mass-spectrometric techniques available, inductively coupled plasma mass spectrometry (ICP-MS) and thermal ionization mass spectrometry are the most frequently applied methods for nuclear applications. Because of the low detection limits, the ability to analyze the isotopic composition of the elements and the applicability of the techniques for measuring stable as well as radioactive nuclides with similar sensitivity, both mass-spectrometric techniques are an excellent amendment to classical radioactivity counting methods. The paper describes selected applications of multicollector ICP-MS in combination with chromatographic separation techniques and laser ablation for the isotopic analysis of irradiated nuclear fuels. The advantages and limitations of the selected analytical technique for the characterization of such a heterogeneous sample matrix are discussed. (orig.)

  11. Ultraviolet irradiation-induced substitution of fluorine with hydroxyl radical for mass spectrometric analysis of perfluorooctane sulfonyl fluoride.

    Science.gov (United States)

    Wang, Peng; Tang, Xuemei; Huang, Lulu; Kang, Jie; Zhong, Hongying

    2016-01-28

    A rapid and solvent free substitution reaction of a fluorine atom in perfluorooctane sulfonyl fluoride (PFOSF) with a hydroxyl radical is reported. Under irradiation of ultraviolet laser on semiconductor nanoparticles or metal surfaces, hydroxyl radicals can be generated through hole oxidization. Among all fluorine atoms of PFOSF, highly active hydroxyl radicals specifically substitute the fluorine of sulfonyl fluoride functional group. Resultant perfluorooctane sulfonic acid is further ionized through capture of photo-generated electrons that switch the neutral molecules to negatively charged odd electron hypervalent ions. The unpaired electron subsequently initiates α O-H bond cleavage and produces perfluorooctane sulfonate negative ions. Hydroxyl radical substitution and molecular dissociation of PFOSF have been confirmed by masses with high accuracy and resolution. It has been applied to direct mass spectrometric imaging of PFOSF adsorbed on surfaces of plant leaves. PMID:26755143

  12. Challenges and recent advances in mass spectrometric imaging of neurotransmitters

    OpenAIRE

    Gemperline, Erin; Chen, Bingming; Li, Lingjun

    2014-01-01

    Mass spectrometric imaging (MSI) is a powerful tool that grants the ability to investigate a broad mass range of molecules, from small molecules to large proteins, by creating detailed distribution maps of selected compounds. To date, MSI has demonstrated its versatility in the study of neurotransmitters and neuropeptides of different classes toward investigation of neurobiological functions and diseases. These studies have provided significant insight in neurobiology over the years and curre...

  13. Electrospray Ionization Mass Spectrometric Analysis of Highly Reactive Glycosyl Halides

    Directory of Open Access Journals (Sweden)

    Lajos Kovács

    2012-07-01

    Full Text Available Highly reactive glycosyl chlorides and bromides have been analysed by a routine mass spectrometric method using electrospray ionization and lithium salt adduct-forming agents in anhydrous acetonitrile solution, providing salient lithiated molecular ions [M+Li]+, [2M+Li]+ etc. The role of other adduct-forming salts has also been evaluated. The lithium salt method is useful for accurate mass determination of these highly sensitive compounds.

  14. Systematic development of an enzymatic phosphorylation assay compatible with mass spectrometric detection.

    Science.gov (United States)

    de Boer, A R; Letzel, T; Lingeman, H; Irth, H

    2005-02-01

    The enzymatic peptide phosphorylation by cAMP-dependent protein kinase A (PKA) was optimized and monitored by means of electrospray ionization mass spectrometry (ESI-MS). The direct detection of phosphorylated peptides by MS renders labeling unnecessary, reduces time and labor, due to less initial sample pretreatment. In this study the phosphorylation of the peptide malantide by PKA was performed in batch and reaction compounds were detected by ESI-MS after the incubation time. The subsequent product quantitation was accomplished by using one-point normalization. Applying this set-up, optimum solvent conditions (such as salt and modifier content), concentrations of essential reaction compounds (such as cAMP, Mg2+ and ATP), and the influence of reaction properties (such as pH and reaction time) were determined. The reaction milieu has to be suitable for both, the enzymatic reaction and the mass spectrometric detection. We found that the modifier content and the pH value had to be changed after the enzymatic reaction occurred. Through the addition of methanol and acetic acid, the reaction stopped immediately and a more sensitive mass spectrometric detection could be obtained simultaneously. Furthermore, an inhibitor study was performed, testing the inhibition potency of three protein kinase A inhibitors (PKIs). IC50 values were determined and used to calculate the Ki values, that were 7.4, 19.0 and 340.0 nmol/L for PKI(6-22)amide, PKI(5-24)amide, and PKI(14-24)amide, respectively. These data vary between factor 4.4 (for PKI(6-22)amide) and 8.3 (for PKI(5-24)amide) compared to the Ki values described in literature. However, the Ki values are in good agreement with the data mainly obtained by fluorescence- or radioactivity-based methods. Nevertheless, our results indicate that ESI-MS is a realistic alternative to radioactivity and fluorescence detection in determining enzymatic activity. Furthermore we were able to illustrate its high potential as a quantitative

  15. Mass spectrometric detection, identification, and fragmentation of arseno-phytochelatins.

    Science.gov (United States)

    Schmied-Tobies, Maria I H; Arroyo-Abad, Uriel; Mattusch, Jürgen; Reemtsma, Thorsten

    2014-11-01

    Phytochelatins (PC) are cystein-rich oligopeptides in plants for coordination with toxic metals and metalloids via their thiol groups. The composition, structure, and mass spectrometric fragmentation of arseno-PC (As-PC) with PC of different degree of oligomerization (PC2-PC5) in solution were studied using liquid chromatography coupled in parallel to inductively coupled plasma mass spectrometry and electrospray ionization quadrupole time-of-flight mass spectrometry. As-PC were detected from As(PC2) to As(PC5) with an increasing number of isomers that differ in the position of thiol groups bound to As. Thermodynamic modeling supported the identification process in case of these isomers. Mass spectrometric fragmentation of the As-PC does not follow the established pattern of peptides but is governed by the formation of series of As-containing annular cations, which coordinate to As via S, N, or O. Structure proposals for 30 As-PC fragment ions in the range m/z 147.92 to m/z 1290.18 are elaborated. Many of these fragment ions are characteristic to several As-PC and may be suited for a screening for As-PC in plant extracts. The mass spectrometric data offer the perspective for a future more sensitive determination of As-PC by means of liquid chromatography tandem mass spectrometry with multiple reaction monitoring. PMID:25395130

  16. 原子荧光光谱法测定不同产地郁金中砷和硒含量%Determination of Trace Arsenic and Selenium in Curcuma aromatica with Microwave Decomposition-Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    刘艳清; 汪洪武; 蔡璇

    2014-01-01

    After microwave decomposition, the contents of arsenic and selenium in eleven Curcuma aromatica samples were determined by hydride generation atomic fluorescence spectrometry, and plant standard reference materials were used to verify the accuracy and the precision of the analytical method. The experimental conditions were optimized. Under the optimum conditions, there was a good linear relationship between the fluorescence intensity and the contents of arsenic and selenium in the range of 0-20 μg/L with a correlation coefficient of 0.999 8 and 0.999 3, respectively. The recovery rate of arsenic and selenium were in the range of 97.15%-102.87%and 98.35%-101.76%. The results indicated that the contents of arsenic and selenium in different habits of Curcuma aromatica were significant deviation.%应用AFS-930型双道原子荧光光度计,采用湿法消解方式,在选定仪器工作条件下,建立了原子荧光光谱法测定郁金中砷和硒。以工作曲线法测定了不同产地郁金中砷和硒的含量,并用植物标准参考物质评价了分析方法的准确度。在0~20.0μg/L范围内As及Se的线性良好,线性回归方程为:As:If=48.9908 c+55.2433(r=0.9998);Se:If=49.3717 c+46.5837(r=0.9993),砷和硒的回收率分别为97.15%~102.87%和98.35%~101.76%。研究结果表明不同产地郁金中As和Se的含量存在较大差异。

  17. Determination of Lead Content in Phosphate Rock and Concentrate Rock——Flame Atomic Absorption Spectrometric Method%火焰原子吸收光谱法测定磷矿石和精磷矿中的铅含量

    Institute of Scientific and Technical Information of China (English)

    沈治荣; 梁聪; 甘丽; 何红莲

    2011-01-01

    This article describes determination of trace harmful heavy metal-lead element in phosphate rock and concentrate rock with flame atomic absorption spectrometry method.The relative standard deviation of this method is 3.1~14.2%,recovery rate is 90%~104%,the sample detection limit is 0.0008%.The method is accurate,fast,easy,make up for method of determination lead in phosphate rock.It provides effective control method for production of feed additives and fertilizers and so on.%研究了用火焰原子吸收光谱法测定磷矿石或磷精矿中微量的铅的检测方法。此方法的相对标准偏差为3.1%-14.2%,回收率为90%-104%,样品检测下限为0.0008%。

  18. Fluorescent refrigeration

    Science.gov (United States)

    Epstein, Richard I.; Edwards, Bradley C.; Buchwald, Melvin I.; Gosnell, Timothy R.

    1995-01-01

    Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement.

  19. Chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    Uranium dioxide is used as a nuclear-reactor fuel. In order to be suitable for this purpose, the material must meet certain criteria for uranium content, stoichiometry, isotopic composition, impurity content. The following analytical procedures, which are described in detail, are designed to show whether or not a given material meets specifications: uranium by ferrous sulfate reduction in phosphoric acid and dichromate titration method; uranium and oxygen uranium atomic ratio by the ignition (gravimetric) impurity correction method; oxygen to uranium atomic ratios by the polarographic method; carbon (total) by direct combustion-thermal conductivity method; total chlorine and fluorine by pyrohydrolysis ion-selective electrode method; moisture by the coulometric, electrolytic moisture analyzer method; nitrogen by the Kjeldahl method; total sulfur by distillation-spectrophotometric method; isotopic uranium composition by multiple-filament surface-ionization mass spectrometric method; spectrochemical determination of trace elements in high-purity uranium dioxide; volatile fluoride impurities by spectrochemical method using the rotating-disk spark technique; spectrochemical determination of silver by gallium oxide carrier D-C arc technique; rare earths by copper spark-spectrochemical method; impurity elements by a spark-source mass spectrographic method; surface area by nitrogen absorption method; total gas in reactor-grade uranium dioxide pellets; thorium and rare earth elements by spectroscopy; hydrogen by inert gas fusion; and uranium isotopic analysis by mass spectrometry. (JMT)

  20. Chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets

    International Nuclear Information System (INIS)

    Uranium dioxide is used as a nuclear-reactor fuel. In order to be suitable for this purpose, the material must meet certain criteria for uranium content, stoichiometry, isotopic composition, impurity content. The following analytical procedures, which are described in detail, are designed to show whether or not a given material meets specifications: uranium by ferrous sulfate reduction in phosphoric acid and dichromate titration method; uranium and oxygen uranium atomic ratio by the ignition (gravimetric) impurity correction method; oxygen to uranium atomic ratios by the polarographic method; carbon (total) by direct combustion-thermal conductivity method; total chlorine and fluorine by pyrohydrolysis ion-selective electrode method; moisture by the coulometric, electrolytic moisture analyzer method; nitrogen by the Kjeldahl method; total sulfur by distillation-spectrophotometric method; isotopic uranium composition by multiple-filament surface-ionization mass spectrometric method; spectrochemical determination of trace elements in high-purity uranium dioxide; volatile fluoride impurities by spectrochemical method using the rotating-disk spark technique; spectrochemical determination of silver by gallium oxide carrier D-C arc technique; rare earths by copper spark-spectrochemical method; impurity elements by a spark-source mass spectrographic method; surface area by nitrogen absorption method; total gas in reactor-grade uranium dioxide pellets; thorium and rare earth elements by spectroscopy; hydrogen by inert gas fusion; and uranium isotopic analysis by mass spectrometry

  1. Energy dispersive X-ray fluorescent system and techniques for analyses of ores and geological products

    International Nuclear Information System (INIS)

    Energy dispersive X-ray fluorescent analyzer based on build-in microcomputer MKC-64 (APPLE 2 compatible) was developed. The spectrometric tract comprises the standard units in NIM standard. The data storage was done by direct memory access, which provides treatment of the information in real time. Using above system a technique was developed for analysis of Fe, Cu, Zn, Pb, Ag and other elements in ores, geological and metallurgical products. For simultaneous excitation of elements in such a wide range of atomic numbers a measuring head with Am241 source was constructed. A developed software allows a completely automatic quantitative analysis. The intensity-correction model was used for reduction of the interelement influence. The application of the system and the technique in factory conditions shows the reproducibility of 0.4% rel. for measuring time of 500 s. and source activity 100 mCi. The accuracy of the analysis for 100 samples measured in metallurgical plant was less than 7% rel. (author)

  2. 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

    International Nuclear Information System (INIS)

    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)

  3. 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。

  4. 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.

  5. Determination of Mercury in Peanut by Microwave Digestion Atomic Fluorescence Spectrometry%微波消解原子荧光光度法测定花生样品中的汞

    Institute of Scientific and Technical Information of China (English)

    何超君; 张激光; 卢思桥

    2012-01-01

    Trace Hg in peanut was determined by atomic fluorescence spectrometry(AFS) with microwave digestion. The detection limit of mercury was 0.000 4 μg/g(n=11), the linear range for mercury was 0.001~6 μg/g, the correlation coefficieni was 0.999 95,and relative standard deviation (RSD,n=7) was in the range of 4.84%~S 30%, the recovery of the method was in the range of 91.00%~114.00%, The experiment results show that the concentration of Hg is lower than the maximum allowable level of Hg in our food standard.The proposed method is rapid and convenient, the result is accurate and reliable, and it is suitable for the determination of trace Hg in peanut.%采用微波消解技术—原子荧光光度法测定花生样品中痕量Hg.方法检出限为0.0004μg/g,线性范围:0.0001~6 μg/g,相关系数r=0.999 95,相对标准偏差(RSD,n=7)4.84%~5.30%,加标回收率在91%~114%之间.实验证明:花生中有害元素Hg的含量远低于我国粮食(成品粮)总Hg允许限标准.方法简便、快速,结果准确、可靠,能够满足花生样品中痕量Hg的测定.

  6. Standard test methods for chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solutions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, spectrochemical, nuclear, and radiochemical analysis of nuclear-grade uranyl nitrate solution to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Determination of Uranium 7 Specific Gravity by Pycnometry 15-20 Free Acid by Oxalate Complexation 21-27 Determination of Thorium 28 Determination of Chromium 29 Determination of Molybdenum 30 Halogens Separation by Steam Distillation 31-35 Fluoride by Specific Ion Electrode 36-42 Halogen Distillate Analysis: Chloride, Bromide, and Iodide by Amperometric Microtitrimetry 43 Determination of Chloride and Bromide 44 Determination of Sulfur by X-Ray Fluorescence 45 Sulfate Sulfur by (Photometric) Turbidimetry 46 Phosphorus by the Molybdenum Blue (Photometric) Method 54-61 Silicon by the Molybdenum Blue (Photometric) Method 62-69 Carbon by Persulfate Oxidation-Acid Titrimetry 70 Conversion to U3O8 71-74 Boron by ...

  7. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide.

    Science.gov (United States)

    Pourjavid, Mohammad Reza; Sehat, Ali Akbari; Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L(-1) for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31-355 μg L(-1) for Mn(II) and 0.34-380 μg L(-1) for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. PMID:24411390

  8. Identification and expression of a gfpK79R mutant of green fluorescent protein

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A mutant strain of E.coli showing strong green fluorescence is obtained during the study of cloning and expression of blue fluorescent protein gene bfp. A recombinant plasmid pHN122 has been isolated. It is demonstrated by enzyme digestion, subcloning and sequence analysis that it contains both of bfp and gfpK79R mutant genes. The results of spectrometric analysis show that GFPK79R expressed by pHN122 is the same as the wild type GFP, but its fluorescent intensity is increased 1.25~2.44-fold.

  9. Inductively coupled plasma atomic emission spectrometric determination of acid-soluble metal elements chromium,manganese, zinc and copper in talcum powder%电感耦合等离子体原子发射光谱法测定滑石粉中酸溶金属元素铬锰锌铜

    Institute of Scientific and Technical Information of China (English)

    胡晓静; 曾泽; 王长文; 仇薪越; 牟明仁; 富瑶; 沈桂玲; 刘向宽

    2011-01-01

    After digestion by aqua regia with microwave and selection of corresponding spectral lines at 267. 7, 257. 6, 213. 8 and 324. 7 nm as analytical lines, the acid-dissoluble metal elements including chromium, manganese, zinc and copper in talcum powder were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES) under optimized conditions with radio frequency power of 1 250 W, auxiliary air flow rate of 0. 60 L/min and atomizer pressure of 26 psi. When the concentration of each testing element was 2. 0 μg/mL, the interferences caused by 20. 0 μg/mL of I-ron, magnesium, calcium, aluminum, zinc, nickel and copper were all less than 5 %. Since the contents of these elements in talcum powder were less than 1 %, their influence on the determination could be ignored. The detection limits of chromium, manganese, zinc and copper were 0. 004 8, 0. 003 8, 0. 001 and 0. 002 6 μg/mL, respectively. This proposed method was applied in actual samples, and the determination results were consistent with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) with relative standard deviations (RSD, n = 8) of 1.1%-4. 2% and recoveries of 93 %-107 %.%以王水作溶剂,微波消解法消解样品,选择267.7、257.6、213.8和324.7 nm波长的光谱线分别作为铬、锰、锌和铜的分析线,在发射功率为1 250 W、辅助气流量为0.60 L/min、雾化器压力为26 psi的优化条件下以电感耦合等离子体原子发射光谱法(ICP-AES)测定了滑石粉中酸溶金属元素铬、锰、锌、铜含量.样品中的基体组分硅酸镁在王水中的溶解量很少,对测定没有影响.当测定待测元素浓度均为2.0μg/mL的溶液时,20.0 μg/mL的铁、镁、钙、铝、锌、镍、铜对待测元素的干扰均小于5%.由于滑石粉中这些元素含量小于1%,因此它们对测定的影响可以忽略.铬、锰、锌、铜的检出限分别为0.004 8、0.003 8、0.001、0.002 6μg/mL.滑石粉样品分析

  10. Column solid phase extraction and flame atomic absorption spectrometric determination of manganese(II) and iron(III) ions in water, food and biological samples using 3-(1-methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid on synthesized graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Pourjavid, Mohammad Reza, E-mail: pourjavid@gmail.com [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of); Sehat, Ali Akbari [Department of Analytical Chemistry, Faculty of Chemistry, University College of Science, University of Tehran, P.O. Box 14155-6455, Tehran (Iran, Islamic Republic of); Arabieh, Masoud; Yousefi, Seyed Reza; Hosseini, Majid Haji; Rezaee, Mohammad [NFCRS, Nuclear Science and Technology Research Institute, P.O. Box 11365-8486, Tehran (Iran, Islamic Republic of)

    2014-02-01

    A modified, selective, highly sensitive and accurate procedure for the determination of trace amounts of manganese and iron ions is established in the presented work. 3-(1-Methyl-1H-pyrrol-2-yl)-1H-pyrazole-5-carboxylic acid (MPPC) and graphene oxide (GO) were used in a glass column as chelating reagent and as adsorbent respectively prior to their determination by flame atomic absorption spectrometry. The adsorption mechanism of titled metals complexes on GO was investigated by using computational chemistry approach based on PM6 semi-empirical potential energy surface (PES). The effect of some parameters including pH, flow rate and volume of sample and type, volume and concentration of eluent, as well as the adsorption capacity of matrix ions on the recovery of Mn(II) and Fe(III) was investigated. The limit of detection was 145 and 162 ng L{sup −1} for Mn(II) and Fe(III), respectively. Calibration was linear over the range of 0.31–355 μg L{sup −1} for Mn(II) and 0.34–380 μg L{sup −1} for Fe(III) ions. The method was successfully applied for the determination of understudied ions in water, food and biological samples. - Highlights: • We use synthesized graphene oxide as adsorbent for SPE of Mn(II) and Fe(III) ions. • Adsorption mechanism was investigated by PM6 semi-empirical potential energy surface. • Detection limits were 145 and 162 ng L{sup −1} for Mn and Fe, respectively. • The preconcentration factor was 325 and sample flow rate is 8 mL min{sup −1}. • It was successfully applied to the determination of Mn and Fe ions in real samples.

  11. Microwave Digestion and Continuum Source Atomic Absorption Spectrometric Determination of Six Metal Elements in Medlar(Mespilus germanica L.) Fruit%微波消解-连续光源原子吸收法快速顺序测定枸杞果中的6种金属元素

    Institute of Scientific and Technical Information of China (English)

    高向阳; 王银娟; 卢彬

    2011-01-01

    A new rapid method was established to determine metal elements in medlar fruit by microwave digestion and continuum source atomic absorption spectrometry.Samples were subjected to microwave digestion before simultaneous determination of six metal elements,including iron,zinc,copper,manganese,cadmium and lead.The established method presented a limit of detection ranging from 0.006070 to 0.04975 μg/L.The precision RSDs were between 1.5% and 5.0%(n = 12).The mean spike recoveries for the six metal elements ranged from 86.68% to 111.7%(n = 6).This method has been used to simultaneously determine iron,zinc,copper,manganese,cadmium and lead in medlar fruit with the benefits of rapidity,simplicity and low cost and satisfying results.%建立一种微波消解-连续光源原子吸收法快速测定枸杞果中金属元素的新方法。通过微波消解快速处理样品,用连续光源原子吸收法同时顺序测定枸杞果中的铁、锌、铜、锰、镉、铅6种金属元素,并对仪器使用条件、金属元素含量、精密度、检出限、回收率等进行研究。结果表明:方法检出限为0.006 07 0~0.04975μg/L,RSD为1.5%~5.0%,回收率为86.68%~111.7%。该法用于枸杞中6种金属元素的同时顺序测定,具有快速、简便、成本低廉等特点,分析结果令人满意。

  12. The hydrolysis of aluminium, a mass spectrometric study

    OpenAIRE

    Sarpola, A.

    2007-01-01

    Abstract This thesis is focused on the hydrolysis of aluminium, the polymerisation of the hydrolysis products, and how these can be monitored by mass spectrometric methods. The main aim of this research is to figure out how the aqueous speciation of aluminium changes as a function of pH (3.2–10), concentration (1–100 mM), reaction time (1s–14d), and counter anion (Cl-, SO42-, HCOO-). The method used was electrospray mass spectrometry. The results showed more variable speciation than those ...

  13. Mass spectrometric thermodynamic studies of oxide systems and materials

    Science.gov (United States)

    Stolyarova, V. L.

    2016-01-01

    Progress in methods of synthesis of advanced materials as well as utilization of such materials at high temperatures requires information on the vaporization processes and thermodynamic properties of oxide systems. The optimal experimental method for these purposes is high-temperature mass spectrometry. This review summarizes and classifies experimental results obtained in mass spectrometric studies of the high-temperature thermodynamic properties of oxide systems and materials carried out in the last two decades. Published data on the vaporization processes and thermodynamic properties of oxide materials for high-temperature technologies are discussed from the standpoint of acid-base concept and model approaches including statistical thermodynamic methods. The bibliography includes 248 references.

  14. Time and spectrometric parameters of photomultiplier 85 and photomultiplier 87

    International Nuclear Information System (INIS)

    A light-pulse generator using a type AL102B light-emitting diode has been used to investigate the temporal and spectrometric parameters of the small FEU-85 and FEU-87 photomultipliers. It was found that the time resolution of the FEU-85 and FEU-87 may be improved by 20-50% through suitable choice of the individual voltage divider. It has been shown that the time and amplitude resolution of the FEU-85 is inversely proportional to the square root of the number of photoelectrons over a wide range of illumination intensities

  15. Mass spectrometric imaging of ginsenosides localization in Panax ginseng root

    OpenAIRE

    Taira, Shu; Ikeda, Ryuzo; Yokota, Naohiko; OSAKA, Issey; Sakamoto, Manabu; Kato, Mitsuro; Sahashi, Yuko

    2010-01-01

    We succeeded in performing mass spectrometric imaging (MSI) of the localization of ginsenosides (Rb_1, Rb_2 or R_c, and Rf) in cross-sections of the Panax ginseng root at a resolution of 100 μm using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Tandem mass spectrometry (MS/MS) of alkali metal-adducted ginsenoside ions revealed structural information of the corresponding saccharides and agricones. MALDI-MSI confirmed that localization of ginsenosides in the cortex ...

  16. Photometric and emission-spectrometric determination of boron in steels

    International Nuclear Information System (INIS)

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated. (orig.)

  17. Photometric and emission-spectrometric determination of boron in steels

    Energy Technology Data Exchange (ETDEWEB)

    Thierig, D.

    1982-01-01

    A method for the photometric determination of boron in unalloyed and alloyed steels is described, in which Curcumine is used as reagent. A separation of boron is not necessary. Limit of detection: 0.0003% B. The decomposition of boron nitride in the steel is achieved by heating the whole sample in fuming sulphuric acid/phosphoric acid. For the emission spectrometric investigation of solid steel samples and for the spectrochemical analysis of solutions with plasma excitation working parameters are given and possibilities of interferences are demonstrated.

  18. Solid Phase Extraction of Lead Using Eggshell Membrane in Water Samples Prior to Graphite Furnace Atomic Absorption Spectrometric Determination%鸡蛋膜固相萃取-石墨炉原子吸收光谱法测定水样中的微量铅

    Institute of Scientific and Technical Information of China (English)

    刘金; 彭元; 陈红梅; 程先忠

    2012-01-01

    鸡蛋膜是由蛋白质组成的一种纤维状的生物膜.本研究利用扫描电镜和红外光谱对鸡蛋膜的结构进行分析表征,证实其具有网状结构,表面存在着—OH、—COOH、—NH2等官能团,能与一些金属离子产生吸附和交换作用.在pH =6的条件下,用蛋膜作吸附剂分离富集水样中的微量铅,5 mL 3%的硝酸进行洗脱,然后采用石墨炉原子吸收光谱法进行测定.实验中对吸附分离介质、溶液流速、蛋膜用量、洗脱剂浓度及共存离子的影响等条件进行了优化和讨论.在最佳的实验条件下,蛋膜对铅的富集倍数为30,方法检出限(3σ)为0.017 ng/mL,相对标准偏差(RSD,n=11)为3.45%,加标回收率为96.0% ~ 104.2%.与现行的分离富集方法相比,建立的方法具有简单、无毒、成本低的优点,用于实际水样中铅的分析能够获得满意的结果.%A chicken eggshell membrane (ESM) is composed of many protein fibers, and available in large quantities as a by-product of the food industry. According to a study by Scanning Electron Microscope ( SEM ) and Fourier Transform Infrared ( FTIR) Spectrometry, the ESM with an intricate lattice network of stable and water-insoluble fibers, and special functional groups such as hydroxyl ( —OH) , carboxyl ( —COOH) , aminol ( —NH2 ) , showed an excellent potential for adsorption and exchange of metal ions. In this paper, the ESM was applied to separate and enrich Pb (II) from a water sample under a pH of 6. The trace lead eluted by 5 mL 3% HN03 was determined by using Graphite Furnace Atomic Absorption Spectrometry ( GFAAS ) . Important parameters, such as the sample pH, sample flow rate, concentration and volume of eluent, and interference of coexisting ions were comprehensively studied and optimized. Under the optimized conditions, an enrichment factor of 30 was obtained. The method detection limit for lead was 0.017 ng/mL (3

  19. Nondestructive characterization of municipal-solid-waste-contaminated surface soil by energy-dispersive X-ray fluorescence and low-Z (atomic number) particle electron probe X-ray microanalysis.

    Science.gov (United States)

    Gupta, Dhrubajyoti; Ghosh, Rita; Mitra, Ajoy K; Roy, Subinit; Sarkar, Manoranjan; Chowdhury, Subhajit; Bhowmik, Asit; Mukhopadhyay, Ujjal; Maskey, Shila; Ro, Chul-Un

    2011-11-01

    The long-term environmental impact of municipal solid waste (MSW) landfilling is still under investigation due to the lack of detailed characterization studies. A MSW landfill site, popularly known as Dhapa, in the eastern fringe of the metropolis of Kolkata, India, is the subject of present study. A vast area of Dhapa, adjoining the current core MSW dump site and evolving from the raw MSW dumping in the past, is presently used for the cultivation of vegetables. The inorganic chemical characteristics of the MSW-contaminated Dhapa surface soil (covering a 2-km stretch of the area) along with a natural composite (geogenic) soil sample (from a small countryside farm), for comparison, were investigated using two complementary nondestructive analytical techniques, energy-dispersive X-ray fluorescence (EDXRF) for bulk analysis and low-Z (atomic number) particle electron probe X-ray microanalysis (low-Z particle EPMA) for single-particle analysis. The bulk concentrations of K, Rb, and Zr remain almost unchanged in all the soil samples. The Dhapa soil is found to be polluted with heavy metals such as Cu, Zn, and Pb (highly elevated) and Ti, Cr, Mn, Fe, Ni, and Sr (moderately elevated), compared to the natural countryside soil. These high bulk concentration levels of heavy metals were compared with the Ecological Soil Screening Levels for these elements (U.S. Environment Protection Agency) to assess the potential risk on the immediate biotic environment. Low-Z particle EPMA results showed that the aluminosilicate-containing particles were the most abundant, followed by SiO2, CaCO3-containing, and carbonaceous particles in the Dhapa samples, whereas in the countryside sample only aluminosilicate-containing and SiO2 particles were observed. The mineral particles encountered in the countryside sample are solely of geogenic origin, whereas those from the Dhapa samples seem to have evolved from a mixture of raw dumped MSW, urban dust, and other contributing factors such as wind

  20. 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。

  1. 断续流动原子荧光法测定铅锡合金中的痕量锑%Determination of Trace Amount of Antimony in Lead-tin Alloy by Intermittent Flow Atomic Fluorescence Spectrometry

    Institute of Scientific and Technical Information of China (English)

    马毅红; 尹艺青; 陈玉珍

    2012-01-01

    目的:建立氢化物发生双道原子荧光法测定铅锡合金中锑含量的方法,为测定铅锡合金中锑提供依据。方法:选择了最佳的仪器条件,进行样品处理方法、KBH4浓度、检出限、回收率等研究。结果:本方法的标准曲线方程y=157.56x-2.3962,相关系数γ=0.9999,线性范围为0~40μg/L,精密度为1.3%,检出限为0.0304μg/L,回收率达115%。结论:本方法操作简单、快速、灵敏度高、干扰少,可获得满意的结果。%Purpose: A analytical method is recommended for determination of Trace Amount of Antimony in Lead-Tin Alloy by hydride generation double channel atomic fluorescence spectrometry,which provides basis for its measurement.Methods: Optimum condition for the instrument determination is applied to conduct researches relating to the method of sampling,concentration of KBH4,detection limits and recovery rate.Results: The standard curve of the linear equation was y=157.56x-2.3962 with correlation coefficient γ = 0.9999 and linear range of 0~40 μg/L.The precision and the detection limits were 1.3 % and 0.0304 μg/L respectively while the returns-ratio achieves 115 %.Conclusion: The method is easy,fast,highly sensitive and with no much interference during the operation,which can lead to satisfactory results.

  2. 微波消解氢化物原子荧光法测定食品中的砷和汞%Simultaneous determination of arsenic and mercury in food by microwave digestion and atomic fluorescence spectroscopy

    Institute of Scientific and Technical Information of China (English)

    郭同兵; 黄谦; 刘剑波

    2011-01-01

    A process of closed and high pressure microwave digestion with atomic fluorescence spectrometer for simultaneously determine As and Hg in food was established. Compared with traditional wet digestion method, the microwave digestion features simple operation, fast, little interference and excellent process controllability. After detect rice, meat, mineral water.aquatic product and so on, we find the detection limits for arsenic and mercury were 0. 030 6 μg/L and 0. 005 2 μg/L respectively. The relative standard deviation for As was 2. 40%,while 1. 39% for Hg. The recovery for As was in the rang of 99. 4% - 101. 2% and 94. 5%~ 106. 5% for Hg. And the As correlation coefficient was 0. 999 7, while the Hg was 0. 999 6. The result is fine, and is fit for simultaneously determine As and Hg in food.%采用高压密闭微波消解氢化物原子荧光法对食品中砷、汞进行同时测定,并与传统的湿法消解进行比较.结果表明:该法具有操作简单、快速、干扰少、良好的过程可控性等优点.通过对大米、肉类罐头、矿采水和水产品等样品的检测,发现砷、汞的检出限分别为0.0306,0.0052 μg/L;相对标准偏差(RSD):砷为2.40%,Hg为1.39%;回收率:As为99.4%~101.2%,Hg为94.5%~106.5%;相关系数(r):As为0.999 7,Hg为0.999 6.结果良好,适用于多种食品中砷和采的同时检测.

  3. Targeted quantitative mass spectrometric immunoassay for human protein variants

    Directory of Open Access Journals (Sweden)

    Nedelkov Dobrin

    2011-04-01

    Full Text Available Abstract Background Post-translational modifications and genetic variations give rise to protein variants that significantly increase the complexity of the human proteome. Modified proteins also play an important role in biological processes. While sandwich immunoassays are routinely used to determine protein concentrations, they are oblivious to protein variants that may serve as biomarkers with better sensitivity and specificity than their wild-type proteins. Mass spectrometry, coupled to immunoaffinity separations, can provide an efficient mean for simultaneous detection and quantification of protein variants. Results Presented here is a mass spectrometric immunoassay method for targeted quantitative proteomics analysis of protein modifications. Cystatin C, a cysteine proteinase inhibitor and a potential marker for several pathological processes, was used as a target analyte. An internal reference standard was incorporated into the assay, serving as a normalization point for cystatin C quantification. The precision, linearity, and recovery characteristics of the assay were established. The new assay was also benchmarked against existing cystatin C ELISA. In application, the assay was utilized to determine the individual concentration of several cystatin C variants across a cohort of samples, demonstrating the ability to fully quantify individual forms of post-translationally modified proteins. Conclusions The mass spectrometric immunoassays can find use in quantifying specific protein modifications, either as a part of a specific protein biomarker discovery/rediscovery effort to delineate the role of these variants in the onset of the disease, progression, and response to therapy, or in a more systematic study to delineate and understand human protein diversity.

  4. Standalone multidetector alpha-spectrometric counting and analysis system

    International Nuclear Information System (INIS)

    This document describes the usage and maintenance of a standalone radioactivity counting and analysis system called LOW LEVEL PHA. It was developed for use in multi-sample alpha spectrometric analysis. The LOW LEVEL PHA system is controlled by a MIK-11/2 microcomputer in 28K of memory and utilizes a double density, dual-floppy disk for data storage. Detectors are interfaced to the computer via CAMAC equipment (Computer Automated Measurement and Control). The system supports 32 simultaneously active and independent alpha particle detectors. It operates with collection rates of up to 300 counts per second from all active detectors, using 128 channels per spectrum and a dynamic energy range of 1.5 MeV. The system is not limited, however, to these conditions. In addition to spectral acquisition, the system provides several analysis functions which include peak identification, curve-smoothing, integration, linear and logarithmic scale graphics, and corrections for base-line shift, deadtime, and background counts. These functions can be implemented while other spectra are being collected. The LOW LEVEL PHA system represents a highly cost-effective means of acquiring alpha spectrometric data from a large number of samples simultaneously, with rapid data analysis capability. This is particularly suitable to analytical and environmental research applications where a small number of alpha-emitting radionuclides are measured at a time, e.g., isotopes of Pu or Am. 23 figures

  5. Mass spectrometric detection of radiocarbon for dating applications

    Energy Technology Data Exchange (ETDEWEB)

    Synal, H.-A., E-mail: synal@phys.ethz.ch [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland); Schulze-Koenig, T.; Seiler, M.; Suter, M.; Wacker, L. [ETH Zurich, Laboratory of Ion Beam Physics, Building HPK, 8093 Zurich (Switzerland)

    2013-01-15

    Radiocarbon is still the most important nuclide measured by accelerator mass spectrometry (AMS). The related capabilities for dating and tracer studies are eminent not only in archaeology but also drive important applications in the earth and environmental sciences as well as in biomedical research. So far, standard mass spectrometric systems have not been capable of radiocarbon dating because of interfering molecular isobars which, however, can be completely eliminated in charge changing processes at high ion beam energies (MeV) [1,2]. Here, we present a novel type mass spectrometry system for radiocarbon analyses. Radiocarbon dating was performed using 45 keV {sup 14}C ions from the ion source and a molecule dissociation unit kept at ground potential. This proof-of-principle experiment demonstrates for the first time the feasibility of mass spectrometric radiocarbon dating without an accelerator. The results obtained will be the basis of an optimized design for a radiocarbon dating instrument comparable in size, complexity and cost to standard mass spectrometers.

  6. Electric focusing preconcentration device for element composition monitoring of air aerosols by atomic emission spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dočekal, Bohumil; Mikuška, Pavel; Šikola, T.; Večeřa, Zbyněk; Zlámal, J.

    Hamburg : University of Hamburg, 2006 - (Broekaert, J.). B56 [ISEAC34. International Symposium on Environmental Analytical Chemistry /34./. 04.06.2006-08.06.2006, Hamburg] R&D Projects: GA AV ČR IAA400310505 Keywords : electrostatic pre-concentration * airborne particles * atomic emission spectrometric detection Subject RIV: CB - Analytical Chemistry, Separation

  7. Determination of ash content of coal using nuclear borehole logging spectrometric gamma-gamma technique

    International Nuclear Information System (INIS)

    During the past decade, increasing effort has been given to monitoring coal quality in the search, production and preparation sequence. Considerable research and development has been carried out on nuclear methods for determination of ash in coal. A number of nuclear techniques are now well established for coal analysis. In particular, the spectrometric gamma-gamma technique is based on the existence of a simple correlation between the ash content and the equivalent atomic number of coal. This technique records and uses the count rates of the backscatter spectrum. These count rates describe the changes in spectral shape which are due to ash content variations. This method is presented along with a short review of the physical background. The report includes the simulation of in situ borehole probe readings using a MONTE CARLO tracking program. Simulating the transport through matter of gamma-rays by MONTE CARLO techniques essentially attempts to reproduce the actual statistical nature of the interaction processes. Random numbers are used throughout, along with known nuclear data, to select the parameters which influence a particle's history. Such an approach can deal with complex geometries through which the particles move. Biaising or weightening techniques are applied for variance reduction, so as to minimise the statistical errors. The basic features of biaising as well as the description of the program are given. A semi-theoretical approach is discussed for the determination of ash content of coal seam using the simulated spectrum

  8. Fluorescence Microscopy of Nanoscale Silver Oxide Thin Films

    Institute of Scientific and Technical Information of China (English)

    PAN Xin-Yu; JIANG Hong-Bing; LIU Chun-Ling; GONG Qi-Huang; ZHANG Xi-Yao; ZHANG Qi-Feng; XU Bei-Xue; WU Jin-Lei

    2003-01-01

    The experimental conditions for photoactivated intermittent fluorescence from nanoscale silver oxide were studied with fluorescence microscopy. Strong fluorescence was observed from the Ag?O particles with size of 10-20nm excited with both blue and green light. We observed the saturation of photoexcitation with blue light and explained the experimental results using the model of agglomeration of silver atoms to form small clusters and the fluorescence of Ag2 and Ags clusters.

  9. Atom Chips

    CERN Document Server

    Folman, R; Cassettari, D; Hessmo, B; Maier, T; Schmiedmayer, J; Folman, Ron; Krüger, Peter; Cassettari, Donatella; Hessmo, Björn; Maier, Thomas

    1999-01-01

    Atoms can be trapped and guided using nano-fabricated wires on surfaces, achieving the scales required by quantum information proposals. These Atom Chips form the basis for robust and widespread applications of cold atoms ranging from atom optics to fundamental questions in mesoscopic physics, and possibly quantum information systems.

  10. Electrothermal atomic absorption spectrometric determination of total and hexavalent chromium in atmospheric aerosols

    International Nuclear Information System (INIS)

    A method was developed which allow separate determination of Cr(VI) and total Cr from the same minute sample of atmospheric aerosols. Cr(VI) was leached was with 0.1 M Na2CO3 and the total Cr concentrations were determined after acid digestion. The method was validated by the analysis of certified reference materials, CRM 545, Mess-3 and Pacs-2 with good agreement between certified and found values. Cr concentrations in air samples taken around the chromium smelter show concentrations that exceed the maximum allowed levels in 8 h with higher values closer to the smelter. The limit of detection (LOD) of the method for Cr(VI) determination in air samples was found to be 0.2 ng m-3, i.e. lower than offered by the commonly preferred spectrophotometric and colorimetric techniques

  11. Flame atomic absorption spectrometric determinations of some trace metals after coprecipitation with gold-APDC

    International Nuclear Information System (INIS)

    Complete text of publication follows. For the determination of trace metals in various samples, preconcentration is an inevitable step to overcome interferences. Among various techniques for the separation of trace metals proposed until now, coprecipitation is one of the most useful ones. Many different coprecipitation procedures including use of organic and inorganic collectors have been developed. So far, in the literature, it is reported that APDC, NaDDTC, PAN, TAR, Oxine, etc. as chelating agent for metal-chelate collector have been extensively used for coprecipitation of trace metals. However, metal chelates, especially dithocarbamates, as collectors are ideal for their sensitivities, simplicities and tolerances to interferences.Therefore, in the present work, fundamental studies on the coprecipitation with gold/APDC chelate have been carried out for determination of trace metals in environmental samples by FAAS with microinjection. According to our literature survey, gold/APDC is not used for the coprecipitation of heavy metal ions, until now. In this work, the coprecipitation was carried out in a centrifuge tube. Firstly, the main factors, such as amount of coprecipitant reagent and carrier element, pH of the solution, standing time, sample volume and diverse ions, affecting the coprecipitation of some trace metals were evaluated. Under optimized conditions, the recoveries of Cu, Ni, Pb and Cd were ≥ 95 %. R.S.D. values for ten replicates were lower than 5.0 %. Preconcentration factors were found to be 20. The coprecipitation was applied to various water samples and non-alcoholic beverage.

  12. Advanced miniaturized plasmas as atomic spectrometric detectors for elemental determinations and speciation in environmental sciences

    International Nuclear Information System (INIS)

    Miniaturized plasmas can be well used for determinations of the elements in a wide variety of environmentally relevant samples. All analytes, which can be brought in the gaseous phase can be easily determined with a wide diversity of microplasmas, whereas in liquids glow discharges where the sample solution serves as one of the electrodes is useful. For monitoring metals in gases also possibilities are available. The range of applications of the devices certainly still can be widened considerably when using mass spectrometry detection. By on-line combinations with chromatography the devices certainly also are very useful for metal speciation work.

  13. Mass spectrometric isotope dilution analysis of small calcium concentrations in minerals

    International Nuclear Information System (INIS)

    A mass spectrometric isotope dilution analysis for the determination of small calcium contents is developed. The different steps (decomposition of the mineral including isotope dilution technique, calcium separation and mass spectrometric measurement) of the analytical procedure are described. For a 42Ca spike the optimum spike addition is calculated. The dependence of the analysis error on the mass spectrometric measurements is discussed. Using a chromatographic method with a strong acidic ion exchanger calcium can be completely separated from potassium. The calcium content in the range of 0.15-0.004% of two feldspars and of one lepidolite is determined with external relative standard deviations of 0.9-5.1%. (orig.)

  14. Mass-spectrometric monitoring of the stress reaction during anesthesia

    Science.gov (United States)

    Elizarov, A. Yu.; Levshankov, A. I.; Faizov, I. I.; Shchegolev, A. V.

    2013-10-01

    Clinical testing data for a mass-spectrometric method of estimating the patient's stress reaction to an injury done during anesthesia are presented. The essence of the method is monitoring the respiratory coefficient, which is defined as ratio N of the expiratory mass concentration of CO2 to the inspiratory mass concentration of O2 at each breathing cycle. For on-line monitoring of N, an electron ionization mass spectrometer connected to the breathing circuit of an inhalational anesthesia machine is used. Estimates of the anesthesia adequacy obtained with this method are compared with those obtained with the method that analyzes induced acoustic encephalographic potentials. It is shown that the method suggested is more sensitive to the level of the patient's stress reaction during anesthesia than the induced potential method.

  15. Gamma spectrometric system for measuring low and medium radioactive samples

    International Nuclear Information System (INIS)

    Measuring radioactive samples from environment and animal sub-products which usually have low radioactivity and a mixture of a radionuclides, requires the use of complex spectrometric systems. In our Department such a system was development, currently equipped with scintillation detector. All the electronic modules (High Voltage Supply, Pulse Amplifier, ADC) in the system are fully digitally controlled by the computer via a specialized interface and a special device driver, which is a resident program. The spectrum acquisition is performed in the background by the device driver. Spectrum processing (peak search, background subtraction, radionuclide identification, energy and efficiency calibration, activity and associated error calculation) is done by a special application which has a user friendly graphic interface and includes database and reporting facilities. The next year the system will be equipped with an automatic sample changer for large volume samples. We intend to provide the possibility to use also a HPGe detector. (authors)

  16. Quality assurance of automated gamma-ray spectrometric analysis

    International Nuclear Information System (INIS)

    Fully automatic gamma-ray spectrometric analysis procedures perform complete processing of the spectrum without intervention of the operator. In order to maintain the reliability of the final results the analysis checks the intermediate results automatically. When a disagreement is identified by such a check the uncertainty of the intermediate results is increased in order to accommodate the disagreement. The increased uncertainty is propagated into the uncertainty of the final results in order to take into account the disagreement. This approach was implemented in Canberra's Genie ESP gamma-ray spectrometry package for examining the results of the peak analysis. In addition to this intermediate check also a-posteriori checks of the final results can be performed by statistical analysis. Such analysis shows whether the results are under statistical control and can discover sources of variability which are not taken into account in the uncertainty budget

  17. Gamma-spectrometric results concerning campaign 3. DOMO programme

    Energy Technology Data Exchange (ETDEWEB)

    Willekens, V.

    1996-05-01

    The aim of the DOMO programme is to investigate in three successive campaigns the behaviour of Mixed Oxide (MOX) fuel irradiated up to high burn-up. A fuel rod has been irradiated in the Dodewaard reactor at steady state conditions in order to obtain the required burn-up. The irradiated rods were subjected to a power transient in the PWC-CCD capsule. During the irradiation in the PWC-CCD capsule, the rod power was determined by making the thermal balance of the incoming and outgoing cooling water of the loop. For an independent check of the thermal balance, gamma spectrometry on fission products in the rod was performed after-after irradiation. The gamma spectrometric measurements on the segments U10, X42, J06 of the DOMO programme are described. These measurements were set up in order to determine the power and the burn-up of the segments.

  18. Gamma-spectrometric results concerning campaign 3. DOMO programme

    International Nuclear Information System (INIS)

    The aim of the DOMO programme is to investigate in three successive campaigns the behaviour of Mixed Oxide (MOX) fuel irradiated up to high burn-up. A fuel rod has been irradiated in the Dodewaard reactor at steady state conditions in order to obtain the required burn-up. The irradiated rods were subjected to a power transient in the PWC-CCD capsule. During the irradiation in the PWC-CCD capsule, the rod power was determined by making the thermal balance of the incoming and outgoing cooling water of the loop. For an independent check of the thermal balance, gamma spectrometry on fission products in the rod was performed after-after irradiation. The gamma spectrometric measurements on the segments U10, X42, J06 of the DOMO programme are described. These measurements were set up in order to determine the power and the burn-up of the segments

  19. Reference instruments based on spectrometric measurement with Lucas Cells

    International Nuclear Information System (INIS)

    The Bundesamt fuer Strahlenschutz (Berlin, Germany) and the Paul Scherrer Institute (Villigen, Switzerland) both operate accredited calibration laboratories for radon gas activity concentration. Both the institutions use Lucas Cells as detector in their reference instrumentation due to the low dependence of this detector type on variations in environmental conditions. As a further measure to improve the quality of the reference activity concentration, a spectrometric method of data evaluation has been applied. The electric pulses from the photomultiplier tube coupled to the Lucas Cells are subjected to a pulse height analysis. The stored pulse height spectra are analysed retrospectively to compensate for fluctuations in the electric parameters of the instrumentation during a measurement. The reference instrumentation of both the laboratories is described with the respective spectrum evaluation procedures. The methods of obtaining traceability to the primary calibration laboratories of Germany and Switzerland and data of performance tests are presented. (authors)

  20. Hyphenating multisyringe flow injection lab-on-valve analysis with atomic fluorescence spectrometry for on-line bead injection preconcentration and determination of trace levels of hydride-forming elements in environmental samples.

    Science.gov (United States)

    Long, Xiangbao; Miró, Manuel; Hansen, Elo Harald; Estela, José Manuel; Cerdà, Víctor

    2006-12-15

    In this work the third generation of flow injection analysis, that is, the so-called micro-lab-on-valve (microLOV) approach, is proposed for the first time for the separation, preconcentration, and monitoring of metalloids as hyphenated with atomic fluorescence spectrometry (AFS). This was made feasible by interfacing the micromachined LOV-module with AFS by a multisyringe flowing stream network for on-line postcolumn derivatization of the eluate aimed at generation of hydride species. The potential of this new hyphenated technique for environmental assays was ascertained via determination of ultratrace level concentrations of total inorganic arsenic in freshwater. Employing quantitative preoxidation of As(III) to As(V) in the samples by means of permanganate, the method involves preconcentration of arsenate at pH 10 on a renewable anion exchanger, namely, Q-Sepharose, packed in a LOV microcolumn. The analyte species is afterward stripped out and concurrently prereduced by a 300 microL eluent plug containing 6 mol L(-)1 HCl and 10% KI. The eluate is downstream merged with a metered volume of sodium tetrahydroborate (0.3% w/v) for generation of arsine, which is subsequently quantified by AFS. The flow system facilitates on-column reduction of the retained arsenic with no need for application of programmable stopped flow. Yet, the high concentration of reductant and extreme pH conditions for elution hinder the sorbent to be reused due to gradual deactivation of the functional moieties, so that maximum benefit can be taken from the application of the bead renewable strategy. The proposed procedure is characterized by a high tolerance to metal species and interfering hydride-forming elements. In fact, ratios of Se(IV) to As < or = 5000 and Sb(V) to As < or = 500 are tolerated at the 10% interference level. Under the optimized experimental conditions, a detection limit (3sigma) of 0.02 ng mL(-1) As, a dynamic linear range of 0.05-2.0 ng mL(-1) As (by tailoring the AFS

  1. 氢化物发生原子荧光法测定稻田土中的锑形态%Determination of antimony species in rice paddy soils by hydride generation atomic fluorescence spetrometry

    Institute of Scientific and Technical Information of China (English)

    郎春燕; 周英; 赖晨焕

    2012-01-01

    Antimony species in rice paddy soils in east suburb of Chengdu were determined by hydride generation-atomic fluorescence spectrometry using aqua regia as a digestant and sequential extraction method. The detection limit of Sb was 0. 108 μg/L,and the recoveries of Sb were 96. 9% ~ 104. 8%. The results showed that the interferences from Cu2+ 、Co2+ 、Se4+ 、Sn2 +、Zn2+、Pb2+、As3+ 、As5+ 、Hg2+ which possibly existed in soils could be efficiently eliminated by using the mixture of thiourea and ascorbic acid. The concentrations of antimony were in the range from 0. 92 mg/kg to 2. 52 mg/kg in samples. The average concentration was 1. 76 mg/kg. The results were not much higher than the standard concentrations of Sb in soils in SiChuan( ≈1. 70 mg/kg, 1991). In the horizontal direction, the distribution of antimony species was different due to different soil conditions of rice paddy. The concentration of antimony species in the studied rice paddy soils generally followed the direction of residual phase > organic/sulphidic phase > Fe/Mn hydrous oxides > carbonate fraction > cation exchangeable. There was a very small proportion of cation exchangeable which could be easily absorbed by plants. In the vertical direction, the concentrations of antimony species had a decreasing tendency with the increased depth of soil.%采用王水消解及逐级浸提技术,以氢化物发生-原子荧光法对成都东郊稻田土中的Sb形态进行了分析,方法检出限为0.108 μg/L,回收率为96.9%~104.8%.加入硫脲-抗坏血酸溶液后,土壤样品中可能存在的金属离子Cu2+、Co2+、Se4、Sn2+、Zn2+、pb2+、As3+、As5+、Hg2+对Sb的干扰可以有效地消除;样品Sb含量在0.92 ~2.52 mg/kg之间波动,平均值为1.76 mg/kg,与四川省土壤Sb背景浓度(≈1.70 mg/kg,1991)相比相差不大.水平方向上,各形态Sb的浓度因所处稻田条件的不同而分布各异,大体呈以下规律:残渣态>有机/硫化物结合态>铁/锰

  2. Mass spectrometric determination of early and advanced glycation in biology.

    Science.gov (United States)

    Rabbani, Naila; Ashour, Amal; Thornalley, Paul J

    2016-08-01

    Protein glycation in biological systems occurs predominantly on lysine, arginine and N-terminal residues of proteins. Major quantitative glycation adducts are found at mean extents of modification of 1-5 mol percent of proteins. These are glucose-derived fructosamine on lysine and N-terminal residues of proteins, methylglyoxal-derived hydroimidazolone on arginine residues and N(ε)-carboxymethyl-lysine residues mainly formed by the oxidative degradation of fructosamine. Total glycation adducts of different types are quantified by stable isotopic dilution analysis liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring mode. Metabolism of glycated proteins is followed by LC-MS/MS of glycation free adducts as minor components of the amino acid metabolome. Glycated proteins and sites of modification within them - amino acid residues modified by the glycating agent moiety - are identified and quantified by label-free and stable isotope labelling with amino acids in cell culture (SILAC) high resolution mass spectrometry. Sites of glycation by glucose and methylglyoxal in selected proteins are listed. Key issues in applying proteomics techniques to analysis of glycated proteins are: (i) avoiding compromise of analysis by formation, loss and relocation of glycation adducts in pre-analytic processing; (ii) specificity of immunoaffinity enrichment procedures, (iii) maximizing protein sequence coverage in mass spectrometric analysis for detection of glycation sites, and (iv) development of bioinformatics tools for prediction of protein glycation sites. Protein glycation studies have important applications in biology, ageing and translational medicine - particularly on studies of obesity, diabetes, cardiovascular disease, renal failure, neurological disorders and cancer. Mass spectrometric analysis of glycated proteins has yet to find widespread use clinically. Future use in health screening, disease diagnosis and therapeutic monitoring, and

  3. Characterization of used lubricating oil by spectrometric techniques

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Andressa Moreira de, E-mail: andressa@ctaa.embrapa.br [Embrapa Agroindustria de Alimentos, Guaratiba, Rio de Janeiro, RJ (Brazil); Correa, Sergio Machado [Faculdade de Engenharia. Universidade do Estado do Rio de Janeiro (UERJ), Resende, RJ (Brazil); Silva, Glauco Correa da [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-Elmer{sup R} OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX Shimadzu{sup R} model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100{mu}A, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics

  4. Characterization of used lubricating oil by spectrometric techniques

    International Nuclear Information System (INIS)

    Full text: The engine lubricating oil drags all kinds of impurities generated by wear of internal components. Thus, it is necessary to monitor the physical and chemical properties and concentration of metals in lubricants used to determine the appropriate time to replace them. Moreover, one can monitor the wear of the engines through the levels of metals in oils. To achieve these goals, some detection techniques such as Flame atomic absorption spectrometry (FAAS), Inductively coupled plasma optical emission spectrometry (ICP-OES) and X-ray fluorescence (XRF), have been widely used to determine metals in lubricating oils and also in other oil derivatives. Thus, some of these techniques were used in this study. Also the technique used was Gas chromatography mass spectrometry (GC / MS) for characterization of chromatographic profile of the engine lubricating oil after use. Through the technique of ICP-OES for method of United States Environmental Protection Agency (USEPA) METHOD 6010B - Inductively coupled plasma optical emission spectrometry was performed to characterize metals in lubricating oil motor, using equipment from ICP-OES Perkin-ElmerR OPTIMA 3000 ICP-Winlab and software, obtaining the following identification of metals: barium (Ba), calcium (Ca), lead (Pb), copper (Cu), Chromium (Cr), iron (Fe), magnesium (Mg), molybdenum (Mo) and zinc (Zn). Using the XRF technique, through the equipment EDFRX ShimadzuR model 800HS EDX, Rh tube, applied voltage of 50kV, amperage 100μA, detector Si (Li) cooled with liquid nitrogen and collimator 10mm, we analyzed all the components comprised in the range of Ti to U and Na to SC, identified the following metals: calcium (Ca), zinc (Zn), iron (Fe), copper (Cu), molybdenum (Mo) and nickel (Ni). The characterization was performed by chromatographic methods: USEPA METHOD 5021A - Volatile organic compounds in various sample matrices using equilibrium headspace analysis, USEPA METHOD 8015B - Nonhalogenated Organics Using GC

  5. Fluorescent silver nanoclusters as DNA probes

    Science.gov (United States)

    Obliosca, Judy M.; Liu, Cong; Yeh, Hsin-Chih

    2013-08-01

    Fluorescent silver nanoclusters (few atoms, quantum sized) have attracted much attention as promising substitutes for conventional fluorophores. Due to their unique environmental sensitivities, new fluorescent probes have been developed based on silver nanoclusters for the sensitive and specific detection of DNA. In this review we present the recent discoveries of activatable and color-switchable properties of DNA-templated silver nanoclusters and discuss the strategies to use these new properties in DNA sensing.

  6. Method of double tracer addition for determining uranium in geological samples by mass spectrometric isotope dilution

    International Nuclear Information System (INIS)

    The present work shows the experimental details on the uranium determination in materials by mass spectrometric isotope dilution technique with double tracer (233U + 235U). The mass discrimination phenomenon effect is studied. The uranium concentration values obtained by mass spectrometric isotope dilution technique with double tracer are compared with other techniques. The influence of the sampling in the accurate determination of uranium in the rock sample is discussed. (author)

  7. Fluorescence detection: SPIE volume 743

    International Nuclear Information System (INIS)

    This book contains proceedings arranged into four sessions. They are: Fluorescence spectroscopic techniques; Fluorescence in analysis and materials characterization; Fluorescence in medicine and biochemistry; and Fluorescence in criminalistics

  8. Fluorescence detection: SPIE volume 743

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, E.R.

    1987-01-01

    This book contains proceedings arranged into four sessions. They are: Fluorescence spectroscopic techniques; Fluorescence in analysis and materials characterization; Fluorescence in medicine and biochemistry; and Fluorescence in criminalistics.

  9. Atomic energy

    CERN Multimedia

    1996-01-01

    Interviews following the 1991 co-operation Agreement between the Department of Atomic Energy (DAE) of the Government of India and the European Organization for Nuclear Research (CERN) concerning the participation in the Large Hadron Collider Project (LHC) . With Chidambaram, R, Chairman, Atomic Energy Commission and Secretary, Department of Atomic Energy, Department of Atomic Energy (DAE) of the Government of India and Professor Llewellyn-Smith, Christopher H, Director-General, CERN.

  10. Atom chips

    CERN Document Server

    Reichel, Jakob

    2010-01-01

    This book provides a stimulating and multifaceted picture of a rapidly developing field. The first part reviews fundamentals of atom chip research in tutorial style, while subsequent parts focus on the topics of atom-surface interaction, coherence on atom chips, and possible future directions of atom chip research. The articles are written by leading researchers in the field in their characteristic and individual styles.

  11. The mechanism of 2-furaldehyde formation from D-xylose dehydration in the gas phase. A tandem mass spectrometric study.

    Science.gov (United States)

    Ricci, Andreina; Piccolella, Simona; Pepi, Federico; Garzoli, Stefania; Giacomello, Pierluigi

    2013-07-01

    The mechanism of reactions occurring in solution can be investigated also in the gas phase by suited mass spectrometric techniques, which allow to highlight fundamental mechanistic features independent of the influence of the medium and to clarifying controversial hypotheses proposed in solution studies. In this work, we report a gas-phase study performed by electrospray triple stage quadrupole mass spectrometry (ESI-TSQ/MS) on the dehydration of D-xylose, leading mainly to the formation of 2-furaldehyde (2-FA). It is generally known in carbohydrate chemistry that the thermal acid catalyzed dehydration of pentoses leads to the formation of 2-FA, but several aspects on the solution-phase mechanism are controversial. Here, gaseous reactant ions corresponding to protonated xylose molecules obtained from ESI of a solution containing D-xylose and ammonium acetate as protonating reagent were allowed to undergo collisionally activated decomposition (CAD) into the triple stage quadrupole analyzer. The product ion mass spectra of protonated xylose are characterized by the presence of ionic intermediates arising from xylose dehydration, which were structurally characterized by their fragmentation patterns. As expected, the xylose triple dehydration leads to the formation of the ion at m/z 97, corresponding to protonated 2-FA. On the basis of mass spectrometric evidences, we demonstrated that in the gas phase, the formation of 2-FA involves protonation at the OH group bound to the C1 atom of the sugar, the first ionic intermediate being characterized by a cyclic structure. Finally, energy resolved product ion mass spectra allowed to obtain information on the energetic features of the D-xylose→2-FA conversion. ᅟ PMID:23690250

  12. Atomic polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    Safronova, M. S. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Mitroy, J. [School of Engineering, Charles Darwin University, Darwin NT 0909 (Australia); Clark, Charles W. [Joint Quantum Institute, National Institute of Standards and Technology and the University of Maryland, Gaithersburg, Maryland 20899-8410 (United States); Kozlov, M. G. [Petersburg Nuclear Physics Institute, Gatchina 188300 (Russian Federation)

    2015-01-22

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed.

  13. Atomic Physics

    CERN Document Server

    Foot, Christopher J

    2007-01-01

    This text will thoroughly update the existing literature on atomic physics. Intended to accompany an advanced undergraduate course in atomic physics, the book will lead the students up to the latest advances and the applications to Bose-Einstein Condensation of atoms, matter-wave inter-ferometry and quantum computing with trapped ions. The elementary atomic physics covered in the early chapters should be accessible to undergraduates when they are first introduced to the subject. To complement. the usual quantum mechanical treatment of atomic structure the book strongly emphasizes the experimen

  14. Atomic polarizabilities

    International Nuclear Information System (INIS)

    The atomic dipole polarizability governs the first-order response of an atom to an applied electric field. Atomic polarization phenomena impinge upon a number of areas and processes in physics and have been the subject of considerable interest and heightened importance in recent years. In this paper, we will summarize some of the recent applications of atomic polarizability studies. A summary of results for polarizabilities of noble gases, monovalent, and divalent atoms is given. The development of the CI+all-order method that combines configuration interaction and linearized coupled-cluster approaches is discussed

  15. Atom interferometry

    International Nuclear Information System (INIS)

    We will first present a development of the fundamental principles of atom interferometers. Next we will discuss a few of the various methods now available to split and recombine atomic De Broglie waves, with special emphasis on atom interferometers based on optical pulses. We will also be particularly concerned with high precision interferometers with long measurement times such those made with atomic fountains. The application of atom interferometry to the measurement of the acceleration due to gravity will be detailed. We will also develop the atom interferometry based on adiabatic transfer and we will apply it to the measurement of the photon recoil in the case of the Doppler shift of an atomic resonance caused by the momentum recoil from an absorbed photon. Finally the outlook of future developments will be given. (A.C.)

  16. Collisional and radiative relaxation of the first excited states of rare gases. Energy transfer from argon excited atoms to different molecules and fluorescence of molecular xenon excited by synchrotron radiation

    International Nuclear Information System (INIS)

    In the first section, the measurement of total deexcitation cross sections of the 3P2,1,0 and 1P1 argon states by N2, H2, CO and SF6 using a pulsed gas radiolysis technique and 600 keV electrons is discussed. The energy transfer from the resonant states 3P1 and 1P1 of argon (as excited selectively by synchrotron radiation) to the C3πu state of nitrogen has been studied in more detail. On the basis of these results, the different theoretical models for these reactions have been discussed. In the second section, the fluorescence of the second continuum of molecular xenon at around 1700 A, as excited by synchrotron radiation in the region of the 3P1 1S0 resonance line at 1470 A, is considered. A short lived component of the fluorescence decay has been observed; this is attributed to emission at short interatomic distances from the high vibrational levels of Xe2+ (Ou+). The emissions at the left turning point of the potential curve of the Ou+ state has been observed at λ > 2000 A. From these results, the potential curves for the states Xe2 (Og+) and Xe2* (Ou+) have been estimated and the Franck-Condon factors have also been calculated as a function of the wavelength of the fluorescence. (author)

  17. Highly selective enrichment of phosphopeptides with high-index facets exposed octahedral tin dioxide nanoparticles for mass spectrometric analysis.

    Science.gov (United States)

    Ma, Rongna; Hu, Junjie; Cai, Zongwei; Ju, Huangxian

    2014-02-01

    High-index facets exposed octahedral tin dioxide (SnO2) nanoparticles were successfully synthesized and applied to selectively enrich phosphopeptides for mass spectrometric analysis. The high selectivity and capacity of the octahedral SnO2 nanoparticles were demonstrated by effectively enriching phosphopeptides from digests of phosphoprotein (α- or β-casein), protein mixtures of β-casein and bovine serum albumin, milk, and human serum samples. The unique octahedral SnO2 with abundant unsaturated coordination Sn atoms exhibited enhanced affinity and selective coordination ability with phosphopeptides due to their high chemical activity. The strong affinity led to highly selective capture and enrichment of phosphopeptides for sensitive detection through the bidentate bonds formed between surface atoms and phosphate. The phosphopeptides could be detected in β-casein down to 4 × 10(-9)M or in the mixture of β-casein and BSA with a molar ratio of even 1:100. The performance in selective enrichment of phosphopeptides from drinking milk and human serum showed powerful evidence of high selectivity and efficiency in identifying the low-abundant phosphopeptides from complicated biological samples. This work provided a way to improve the physical and chemical properties of materials by tailoring their exposed facets for selective enrichment of phosphopeptides. PMID:24401440

  18. Mass-spectrometric investigation of thermochemical properties of lanthanide chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Sapegin, A.M.; Baluev, A.V.; Evdokimov, V.I. (AN SSSR, Chernogolovka. Inst. Novykh Khimicheskikh Problem)

    1984-12-01

    Ionization potentials are measured for ions formed during lanthanide chloride molecules ionization by an electron shock with the use of the improved technique of mass-spectral data processing. Energies of atomization and atomic bond scission in molecules of tri-, di-, and monochlorides are defined along with enthalpies of formation of these molecules in a gaseous state.

  19. Mass-spectrometric investigation of thermochemical properties of lanthanide chlorides

    International Nuclear Information System (INIS)

    Ionization potentials are measured for ions formed during lanthanide chloride molecules ionization by an electron shock with the use of the improved technique of mass-spectral data processing. Energies of atomization and atomic bond scission in molecules of tri-, di-, and monochlorides are defined along with enthalpies of formation of these molecules in a gaseous state

  20. Mass spectrometric study of the amipurimycin hexopyranosidic sugar moiety

    Science.gov (United States)

    Almoster Ferreira, M. A.; Borges, C.; Oliveira, M. C.; Pocsfalvi, G.; Rauter, A. P.; Fernandes, A. C.

    1997-11-01

    Amipurimycin is a natural nucleoside that displays a remarkable activity in vitro and in vivo against Pyricularia oryzae, which is responsible for the rice blast disease. Six important precursors for the synthesis of the Amipurimycin sugar moiety were prepared. In order to obtain structural information a mass spectrometric study of these compounds was performed using liquid secondary ion mass spectrometry (LSIMS) with high-energy collision-induced dissociation (CID) experiments on a four-sector instrument. Elimination of methanol is the preferential fragmentation path for five of the six protonated molecules, indicating that protonation plays an important role in the process, whilst for the other protonated molecule loss of water is the main fragmentation. Examination of the [M + Li]+ precursor ion spectra shows that loss of methanol does not occur in three of them, but in the other three gives rise to fairly abundant ions, indicating that in this case methanol elimination implies intramolecular hydrogen transfer, the resulting ion having a very stable structure.

  1. Deep UV imaging by spectrometric full-colour cathodoluminescence microscopy

    International Nuclear Information System (INIS)

    A new deep-UV cathodoluminescence (CL) microscopy is tried on studying design and fabrication of recent solid-state light-emitting (LE) devices that emit near 200 nm light. CL microscopy has enough energy for electronic excitation of deep-UV emitting devices and visualizes distribution map of their electronic structures. The deep-UV imaging system is constructed on our own spectrometric full-colour CL microscope that collects CL spectra at all pixel points of the specimen during regular SEM observation, and at the end of one frame scan, a set of CL spectra is accumulated in the control computer. One frame scan of 512x512 pixels needs 8 to 80 sec, which is unbeatable by any other commercial CL microscopes. Full-colour CL micrograph is constructed using the spectra. The detector, a 32-channel photoelectron multiplier array, has higher sensitivity in UV region than any solidstate linear sensors, and a grating of 300-nm blaze wavelength instead of one at 500-nm blaze wavelength for visible lights, provide CL micrographs of 180-700 nm lights for recent deep-UV LE devices. Some unforeseen light emissions between 200-350 nm regions are observed on various materials and they are discussed correlating with the structure observed in SEM micrographs.

  2. Radio spectrometric survey of un-surveyed areas in Syria

    International Nuclear Information System (INIS)

    The values and distribution of the radioelements e U, e Th, % K and Ur units in the surface geological formations of the west and south sectors of Syrian region, were estimated using carbone gamma ray spectrometric survey. The radiometric maps were prepared, as well as, many geological profiles, cross sections studied in different locations and geochemical samples were analyzed by laboratory gamma ray spectrometry and by x-ray diffractometry, the results of the all sets were compared. In general, the survey shows, low radioelement concentrations in the area, especially on basic rocks (Jabal Al-arab, Hawran) south Syria, and on ultra basic rocks (ophiolitic complex) north-west Syria, but there are some separate anomalous spots were connected with phosphate rocks, detected on cretaceous and Palaeogene age. Some times we noticed high radioelement concentrations haloes associated with fractured zones were already arise from secondary uranium mineralization, as a result of solutions movement through fissures in carbonatic and/or chalk like limestone rocks. finally, the obtained concentrations, represent a background values which has no significant importance for uranium exploration point of view. (author)

  3. Spectrometric measurements of radioisotope activity in the thyroid

    Science.gov (United States)

    Osko, Jakub; Golnik, Natalia

    2008-01-01

    The results of measurements of iodine 131I and technetium 99mTc uptake in human thyroid, performed with scintillation or semiconductor detectors can exhibit a considerable uncertainty due to the differences in the thyroid position in the patient's neck. Basic physical laws of radiation attenuation and scattering show that the final shape of the registered spectrum should depends on the thyroid position in the neck and on the thickness of the tissue between the thyroid and the detector. The use of the spectrometric measuring method is proposed in this work for determination of the iodine gathering effective depth. The performed studies showed that the measurements results can be used for improving the accuracy of the iodine 131I activity in thyroid measurements and for selection of the group of patients for whom the anatomical position of the thyroid or the spatial distribution of the iodine gathering is much different than the standard one, assumed during the calibration of the counters. The results of the measurements were in agreement with Monte-Carlo calculations of the detector response. The method was used in routine monitoring of occupationally exposed persons, using the thyroid counter. A group of six persons with measurable internal contamination was selected and the measurements were performed on consecutive days, so the results could be registered at decreasing iodine activities in the thyroid. Larger series of measurements were performed at Brodno Regional Hospital in Warsaw, for a group of 95 patients after diagnostic administration of iodine 131I.

  4. Determination of iodine to compliment mass spectrometric measurements

    International Nuclear Information System (INIS)

    The dose of iodine-129 to facility personnel and the general public as a result of past, present, and future activities at DOE sites is of continuing interest, WINCO received about 160 samples annually in a variety of natural matrices, including snow, milk, thyroid tissue, and sagebrush, in which iodine-129 is determined in order to evaluate this dose, Currently, total iodine and the isotopic ratio of iodine-127 to iodine-129 are determined by mass spectrometry. These two measurements determine the concentration of iodine-129 in each sample, These measurements require at least 16 h of mass spectrometer operator time for each sample. A variety of methods are available which concentrate and determine small quantities of iodine. Although useful, these approaches would increase both time and cost. The objective of this effort was to determine total iodine by an alternative method in order to decrease the load on mass spectrometry by 25 to 50%. The preparation of each sample for mass spectrometric analysis involves a common step--collection of iodide on an ion exchange bed. This was the focal point of the effort since the results would be applicable to all samples

  5. Rapid identification of viridans streptococci by mass spectrometric discrimination.

    Science.gov (United States)

    Friedrichs, C; Rodloff, A C; Chhatwal, G S; Schellenberger, W; Eschrich, K

    2007-08-01

    Viridans streptococci (VS) are responsible for several systemic diseases, such as endocarditis, abscesses, and septicemia. Unfortunately, species identification by conventional methods seems to be more difficult than species identification of other groups of bacteria. The aim of the present study was to evaluate the use of cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for the rapid identification of 10 different species of VS. A total of 99 VS clinical isolates, 10 reference strains, and 20 strains from our in-house culture collection were analyzed by MALDI-TOF-MS. To evaluate the mass-spectrometric discrimination results, all strains were identified in parallel by phenotypic and genotypic methods. MALDI-TOF-MS identified 71 isolates as the mitis group, 23 as the anginosus group, and 5 as Streptococcus salivarius. Comparison of the species identification results obtained by the MALDI-TOF-MS analyses and with the phenotypic/genotypic identification systems showed 100% consistency at the species level. Thus, MALDI-TOF-MS seems to be a rapid and reliable method for the identification of species of VS from clinical samples. PMID:17553974

  6. Surface acoustic wave nebulization facilitating lipid mass spectrometric analysis.

    Science.gov (United States)

    Yoon, Sung Hwan; Huang, Yue; Edgar, J Scott; Ting, Ying S; Heron, Scott R; Kao, Yuchieh; Li, Yanyan; Masselon, Christophe D; Ernst, Robert K; Goodlett, David R

    2012-08-01

    Surface acoustic wave nebulization (SAWN) is a novel method to transfer nonvolatile analytes directly from the aqueous phase to the gas phase for mass spectrometric analysis. The lower ion energetics of SAWN and its planar nature make it appealing for analytically challenging lipid samples. This challenge is a result of their amphipathic nature, labile nature, and tendency to form aggregates, which readily precipitate clogging capillaries used for electrospray ionization (ESI). Here, we report the use of SAWN to characterize the complex glycolipid, lipid A, which serves as the membrane anchor component of lipopolysaccharide (LPS) and has a pronounced tendency to clog nano-ESI capillaries. We also show that unlike ESI SAWN is capable of ionizing labile phospholipids without fragmentation. Lastly, we compare the ease of use of SAWN to the more conventional infusion-based ESI methods and demonstrate the ability to generate higher order tandem mass spectral data of lipid A for automated structure assignment using our previously reported hierarchical tandem mass spectrometry (HiTMS) algorithm. The ease of generating SAWN-MS(n) data combined with HiTMS interpretation offers the potential for high throughput lipid A structure analysis. PMID:22742654

  7. Functional proteomics with new mass spectrometric and bioinformatics tools

    International Nuclear Information System (INIS)

    A comprehensive range of mass spectrometric tools is required to investigate todays life science applications and a strong focus is on addressing the needs of functional proteomics. Application examples are given showing the streamlined process of protein identification from low femtomole amounts of digests. Sample preparation is achieved with a convertible robot for automated 2D gel picking, and MALDI target dispensing. MALDI-TOF or ESI-MS subsequent to enzymatic digestion. A choice of mass spectrometers including Q-q-TOF with multipass capability, MALDI-MS/MS with unsegmented PSD, Ion Trap and FT-MS are discussed for their respective strengths and applications. Bioinformatics software that allows both database work and novel peptide mass spectra interpretation is reviewed. The automated database searching uses either entire digest LC-MSn ESI Ion Trap data or MALDI MS and MS/MS spectra. It is shown how post translational modifications are interactively uncovered and de-novo sequencing of peptides is facilitated

  8. Use of mass spectrometric methods for field screening of VOC's

    International Nuclear Information System (INIS)

    While mass spectrometric (MS) methods of chemical analysis, particularly gas chromatography-mass spectrometry (GC/MS), have been the mainstay of environmental organic analytical techniques in the laboratory through the use of EPA and other standard methods, field implementation is relatively rare. Instrumentation and methods now exist for utilizing MS and GC/MS techniques in the field for analysis of VOC's in gas phase, aqueous, and soil media. Examples of field investigations utilizing HP 5971A and Viking SpectraTrak systems for analysis of VOC's in all three media will be presented. Mass spectral methods were found to offer significant advantages in terms of speed of analysis and reliability of compound identification over field gas chromatography (GC) methods while preserving adequate levels of detection sensitivity. The soil method in particular provides a method for rapid in-field analysis of methanol preserved samples thus minimizing the problem of volatiles loss which typically occurs with routine use of the EPA methods and remote analysis. The high cost of MS instrumentation remains a major obstacle to more widespread use

  9. Mass spectrometric searches for superheavy elements in terrestrial matter

    Science.gov (United States)

    Korschinek, Gunther; Kutschera, Walter

    2015-12-01

    Recent searches for traces of long-lived superheavy elements (SHEs) in terrestrial materials by mass spectrometric means are reviewed. Positive evidence for long-lived neutron-deficient Th isotopes in Th and Rg isotopes in Au, and a possible A = 292, Z ∼ 122 nuclide in Th was reported from experiments with Inductively Coupled Plasma Sector Field Mass Spectrometry (ICP-SF-MS). These findings were not confirmed with Accelerator Mass Spectrometry (AMS), with abundance limits lower by several orders of magnitude. In addition, the extensive AMS searches for 42 SHE nuclides (A = 288- 310) around the much discussed "island of stability" (Z = 114, N = 184) in natural Pt, Au, Pb, Bi materials are reviewed. Due to the flatness of the mass distribution and the relatively large bandwidth of the mass acceptance in AMS searches, an effectively much larger number of SHE nuclides was scanned in the respective materials. No positive evidence for the existence of long-lived SHEs (t1/2 >108 yr) with abundance limits of 10-12 to 10-16 was found.

  10. Laser induced fluorescence spectroscopy for FTU

    International Nuclear Information System (INIS)

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

  11. Schroedinger atom

    International Nuclear Information System (INIS)

    Features of an electrodynamical interpretation suggested by Schroedinger for the wave function are discribed. According to this conception electron charges are continuously distributed all over the volume of an atomic system. The proof is given that classical electrodynamics keeps its action inside atom. Schroedinger's atom has been shown to be the only model in which electrones do not lose their energy for emission when they move around nucleus. A significance of the distributed electron charge self-field is estimated. Practical applications of this conception have been noted including the new trend in quantum electrodynamics. Experimental and theoretical corroborations of the atom model with a continuous electron charge are adduced

  12. Atomic physics

    International Nuclear Information System (INIS)

    Research activities in atomic physics at Lawrence Berkeley Laboratory during 1976 are described. Topics covered include: experiments on stored ions; test for parity violation in neutral weak currents; energy conservation and astrophysics; atomic absorption spectroscopy, atomic and molecular detectors; theoretical studies of quantum electrodynamics and high-z ions; atomic beam magnetic resonance; radiative decay from the 23Po,2 levels of helium-like argon; quenching of the metastable 2S/sub 1/2/ state of hydrogen-like argon in an external electric field; and lifetime of the 23Po level of helium-like krypton

  13. Geração eletroquímica do hidreto de selênio em sistema de injeção em fluxo com detecção por espectrometria de absorção atômica com chama Ar-Glp Electrochemical hydride generation for selenium determination in a flow injection system with Air-GLP flame atomic absorption spectrometric detection

    OpenAIRE

    Luís Fernando Rebel Machado; Antonio Octavio Jacintho; Maria Fernanda Giné

    2000-01-01

    This paper presents a system for electrochemical hydride generation using flow-injection and atomic absorption spectrometry to determine selenium in biological materials. The electrolytic cell was constructed by assembling two reservoirs, one for the sample and the other for the electrolytic solution separated by a Nafion membrane. Each compartment had a Pt electrode. The sample and electrolyte flow-rates, acidic media, and applied current were adjusted to attain the best analytical performan...

  14. 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. PMID:23931503

  15. Atomic physics

    CERN Document Server

    Born, Max

    1989-01-01

    The Nobel Laureate's brilliant exposition of the kinetic theory of gases, elementary particles, the nuclear atom, wave-corpuscles, atomic structure and spectral lines, electron spin and Pauli's principle, quantum statistics, molecular structure and nuclear physics. Over 40 appendices, a bibliography, numerous figures and graphs.

  16. High-precision mass spectrometric hydrogen isotope ratio measurements

    International Nuclear Information System (INIS)

    The analytical capabilities of mass spectrometric ion-current measurement systems are described on both a theoretical and a practical basis. From the theoretical standpoint, a signal-to-noise ratio (S/N) model that evaluated the fundamental sources of noise present in ion-current measurement systems was developed. Use of this model accurately predicted the performance (precision) for ion-current ratio measurements made by two isotope ratio mass spectrometers, one designed for carbon isotopic measurements, and the other designed for hydrogen isotopic measurements. Isotope ratio measurements differ from current-ratio measurements in that the observed ion-current ratio must be corrected to reflect the ratio of the ion currents due to the isotopic species of interest, which, for hydrogen isotope ratio mass spectrometry, are HD+ and H2+. Interfaces to these two ion currents are described in detail. To compensate for H3+ three measurement procedures, the two-standard calibration, the one-standard differential measurement with electronic H3+ compensation, and the two-standard differential measurement, are described. The one- and two-standard differential measurements were successfully used for measurement of isotopic abundances. Results of a collaborative investigation to validate the use of 18O in place of D as an isotopic label for total body water measurements are presented. In this research both 18O and D were administered simultaneously to several subjects. The weight of total body water of these subjects as measured by the dilution of D into the body water was in good agreement with the results of the 18O measurements. A brief description of the laboratory computer system is also given

  17. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Science.gov (United States)

    Bugalho, R.; Carriço, B.; Ferreira, C. S.; Frade, M.; Ferreira, M.; Moura, R.; Ortigão, C.; Pinheiro, J. F.; Rodrigues, P.; Rolo, I.; Silva, J. C.; Trindade, A.; Varela, J.

    2009-10-01

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Português de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 × 2 × 20 mm3 LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean CDOI-1 is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  18. Single hair cocaine consumption monitoring by mass spectrometric imaging.

    Science.gov (United States)

    Porta, Tiffany; Grivet, Chantal; Kraemer, Thomas; Varesio, Emmanuel; Hopfgartner, Gérard

    2011-06-01

    Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was used to image the distribution of cocaine and its metabolites in intact single hair samples from chronic users down to a concentration of 5 ng/mg. Acquisitions were performed in rastering mode, at a speed of 1 mm/s and in the selected reaction monitoring (SRM) mode on a MALDI triple quadrupole linear ion trap fitted with a high repetition rate laser (1 kHz). Compared to traditional methods based on LC-MS/MS or GC-MS(/MS) which require to segment the hair to obtain spatial resolution, MALDI-MSI, with a straightforward sample preparation beforehand, allowed obtaining a spatial resolution of 1 mm and thus the chronological information about cocaine consumption contained in a single intact hair over several months could be monitored. The analysis time of an intact single hair sample of 6 cm is approximately of 6 min. Cocaine and its metabolites benzoylecgonine, ethylcocaine, and norcocaine were investigated in nine sets of hair samples for forensic purposes. The analyses were accomplished by spraying α-cyano-4-hydroxycinnamic acid (CHCA), 4-chloro-α-cyano-cinnamic acid (Cl-CCA), or (E)-2-cyano-3-(naphthalen-2-yl)acrylic acid (NpCCA) as MALDI matrices. We also propose a rapid strategy for sensitive confirmatory analyses with both MS/MS and MS(3) experiments performed directly on intact hair samples. Since only part of the hair strand is analyzed, additional analyses are possible at any time on the remaining hair from the strand. PMID:21510611

  19. Advanced x-ray spectrometric techniques for characterization of nuclear materials: An overview of recent laboratory activities

    Science.gov (United States)

    Misra, N. L.

    2014-11-01

    Advancements in x-ray spectrometric techniques at different stages have made this technique suitable for characterization of nuclear materials with respect to trace/major element determinations and compositional uniformity studies. The two important features of total reflection x-ray fluorescence spectrometry: 1) requirement of very small amount of sample in ng level 2) multielement analytical capability, in addition to other features, make this technique very much suitable to nuclear materials characterization as most of the nuclear materials are radioactive and the radioactive waste generated and radiation hazards to the operator are minimum when such low amount of sample is used. Similarly advanced features of energy dispersive x-ray fluorescence e.g. better geometry for high flux, reduction in background due to application of radiation filters have made the measurements of samples sealed inside thin alkathene/PVC covers possible with good sensitivity. This approach avoids putting the instrument inside a glove box for measuring radioactive samples and makes the operation/maintenance of the instrument and analysis of the samples possible in easy and fast manner. This approach has been used for major element determinations in mixed uranium-plutonium samples. Similarly μ-XRF with brilliant and micro-focused excitation sources can be used for compositional uniformity study of reactor fuel pellets. A μ-XRF study using synchrotron light source has been made to assess the compositional uniformity of mixed uranium-thorium oxide pellets produced by different processes. This approach is simple as it does not involve any sample preparation and is non-destructive. A brief summary of such activities carried out in our laboratory in past as well as ongoing and planned for the future have been discussed in the present manuscript.

  20. 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.

  1. Determination of Arsenic in Southern Jiangxi Navel Orange Pulp and Peel by Wet Digestion—Atomic Fluorescence Spectrometry%湿法消解-原子荧光光谱法测定赣南脐橙果皮和果肉中的砷含量

    Institute of Scientific and Technical Information of China (English)

    徐媛; 姚明印; 刘木华; 雷泽剑

    2012-01-01

    With a view to detect the heavy metal element in fruits, the contents of element arsenic in peel and the fruit pulp of Southern Jiangxi navel orange were determined by wet digestion-atomic fluorescence spec-trometry. The fruit pulp and peel were preconditioned by wet digestion and then detected by atomic fluorescence spectrometry. The results showed that trace arsenic was contained in pulp and peel, the average amount of arsenic per kg of Southern Jiangxi navel orange was 0.096 mg(peel) ,0.020 (pulp) respectively, the total arsenic content in Southern Jiangxi navel orange conforms to China' s safety and health indicators. The element arsenic in Southern Jiangxi navel orange mainly rests in the peel.%以检测水果中有害元素(以As为例)含量为目的,实验选用赣南脐橙作为样品,采用湿法消解-原子荧光光谱法测定其果皮和果肉中有害元素砷的含量.实验先用湿法消解的方法预处理赣南脐橙的果皮和果肉,制备好样品,再用原子荧光光谱仪测定样品中痕量砷的含量.结果表明,脐橙果皮和果肉中含有微量砷元素,所检测的脐橙中平均含砷量为0.096 mg/kg(果皮)、0.020 mg/kg(果肉),脐橙样品中元素砷主要累积在果皮.

  2. Dosimetric studies, spectrometric, radiographic, metallographic of a new argentinean seed of 125 I used in brachytherapy

    International Nuclear Information System (INIS)

    A new source of 125 I model BraquibacTM has been developed in Argentina for applications in interstitial brachytherapy. The AAPM Task Group 43 (TG-43) recommends that dosimetric characteristics of new sources of brachytherapy of Iodine-125 have been theoretically and experimentally determined before its clinical use. The objectives outlined in this work were the study of the design of the new seed, the calculation of dosimetric parameters and the photons spectra analysis. Its were carried out radiographic and metallographic studies to determine the physical characteristics of the source. For the realization of the dosimetric calculations it was used the Monte Carlo code MCNP5. Values of the radial dose function, g(r), of the constant of dose rate, Λ, of the function of anisotropy of two dimensions, F(r, θ), of the factor and constant of anisotropy its were obtained simulating the source in water according to the recommended methodology in TG-43. The constant of dose rate is similar to 0,880 ± 0,080 c Gy h-1 U-1. The kerma in air rate of reference, SK, was calculated as 1,036 c Gy cm2h-1 mCi-1 simulating the seed in dry air. Its were carried out spectrometric studies using a semiconductor planar detector of HPGe (high purity germanium). Photons spectra showed characteristic x-rays of 125 I with energies of 27,20 keV, 27,47 keV, 31 keV and 31,70 keV gamma photons of 35,5 keV, and x-ray fluorescent coming from the silver nucleus of 22,10 keV, 24,94 keV and 25,45 keV. The angular dependence of the intensity of photons around the seed and in air it was analyzed with the planar detector. This was carried out to study the anisotropy in the photons flow due to variation in the thickness of the titanium wall and of the welding, movements of the silver tube inside the source and deposition of the radioactive material on the silver tube. (Author)

  3. Characterization of 241Am and Pu content in soil from peaceful nuclear explosions regions by γ/X-spectrometric method

    International Nuclear Information System (INIS)

    The γ/X-spectrometric methodology and apparatus for analysis of the 241Am content in the soil and plant samples from the peaceful nuclear explosions areas in Yakutiya and the Perm region are briefly presented. The conclusion is made on the possibility of applying the γ/X-spectrometric methodology for the wide-scale measurements in the peaceful nuclear explosions regions

  4. Significance of Airborne Gamma-ray spectrometric data of Umm bisilla Area, central Eastern Desert, Egypt

    International Nuclear Information System (INIS)

    Umm bisilla area, located in the Central Eastern Desert of Egypt, consists mainly of basement rocks. The present investigation of the airborne spectrometric data is to define the meaningful anomalies from the raw data by applying the significance factor techniques, by calculating the significant radioactive provinces. Determination of the gross structural pattern and broad variations in composition of the crystalline basement, to define the relationships between the tectonic features of the area as interpreted from aeromagnetic data, with the significant anomalies revealed from spectrometric data was carried out through the application of different magnetic techniques. Five significant uraniferous zones were detected associated with Umm Bisilla granite, amphibolite, and grey granite. The intersection of the structural lineaments interpreted from aeromagnetic data illustrated good correlation with the significant uranium anomalous zones interpreted from spectrometric data, and indicated that the concentration is structurally. 15 figs

  5. 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.

  6. 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

  7. Present status for the determination of metallic impurities in nuclear fuels by atomic emission spectroscopy (review report)

    International Nuclear Information System (INIS)

    Present status for the determination of metallic impurities in nuclear fuels by atomic emission spectroscopy (AES) is reviewed. In the first chapter of introduction, brief progress of the developments of AES is described. In the second chapter, emission spectrograph with direct current arc (DCA) or inductively coupled plasma (ICP) source is shown with the emphasis on the confinement of plutonium. In the third chapter, impurity elements and maximum concentration limits in various nuclear fuels and equivalent boron content factors are given on the base of ASTM (American Society for Testing and Materials) standards in 1987. In the fourth chapter, examples of the analyses of nuclear fuels by DCA-AES and carrier distillation method, and the results of standard uranium oxide analysis conducted by 15 AEC-connected laboratories in U.S.A. are presented. In the fifth chapter, the determination of rare earth elements by DCA-AES after the chemical separation of U and Pu by solvent extraction, ion-exchange and so on. In the sixth and seventh chapters, the determination of U and Pu, and metallic impurities in U and Pu fuels by ICP-AES are described, respectively. In the eighth chapter, the determination of Am by ICP-AES is explained. In the ninth chapter, a comparison of the detection limits in aqueous solutions for various spectrometric techniques including recently developed laser-induced atomic fluorescence spectroscopy (LIF) and laser-enhaned ionization spectroscopy (LEI) are given. In the last chapter, experimental plan using DCA-AES and ICP-AES installed this time at Plutonium Fuel Research Laboratory of Oarai Research Establishment is introduced. (author)

  8. Prospects in Analytical Atomic Spectrometry

    CERN Document Server

    Bolshakov, A A; Nemets, V M

    2006-01-01

    Tendencies in five main branches of atomic spectrometry (absorption, emission, mass, fluorescence and ionization spectrometry) are considered. The first three techniques are the most widespread and universal, with the best sensitivity attributed to atomic mass spectrometry. In the direct elemental analysis of solid samples, the leading roles are now conquered by laser-induced breakdown and laser ablation mass spectrometry, and the related techniques with transfer of the laser ablation products into inductively-coupled plasma. Advances in design of diode lasers and optical parametric oscillators promote developments in fluorescence and ionization spectrometry and also in absorption techniques where uses of optical cavities for increased effective absorption pathlength are expected to expand. Prospects for analytical instrumentation are seen in higher productivity, portability, miniaturization, incorporation of advanced software, automated sample preparation and transition to the multifunctional modular archite...

  9. Radiative lifetimes and atomic transition probabilities

    International Nuclear Information System (INIS)

    Radiative lifetimes and atomic transition probabilities have been measured for over 35 neutral and singly ionized species in the Wisconsin Atomic Transition Probabilities (WATP) Program since it began in 1980. Radiative lifetimes are measured using time-resolved laser-induced fluorescence of a slow atomic/ionic beam. These lifetimes are combined with branching fractions to yield absolute atomic transition probabilities for neutral and singly ionized species. The branching fractions are determined from emission spectra recorded using the 1.0 m Fourier-transform spectrometer at the National Solar Observatory. The current focus of the WATP Program is on the rare-earth elements, in particular Tm, Dy, and Ho

  10. Fluorescent optical position sensor

    Science.gov (United States)

    Weiss, Jonathan D.

    2005-11-15

    A fluorescent optical position sensor and method of operation. A small excitation source side-pumps a localized region of fluorescence at an unknown position along a fluorescent waveguide. As the fluorescent light travels down the waveguide, the intensity of fluorescent light decreases due to absorption. By measuring with one (or two) photodetectors the attenuated intensity of fluorescent light emitted from one (or both) ends of the waveguide, the position of the excitation source relative to the waveguide can be determined by comparing the measured light intensity to a calibrated response curve or mathematical model. Alternatively, excitation light can be pumped into an end of the waveguide, which generates an exponentially-decaying continuous source of fluorescent light along the length of the waveguide. The position of a photodetector oriented to view the side of the waveguide can be uniquely determined by measuring the intensity of the fluorescent light emitted radially at that location.

  11. Fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    M.A. Hink

    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

  12. Design of electric focusing preconcentration devices for in-time monitoring of element composition of air aerosols by atomic emission spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Dočekal, Bohumil; Večeřa, Zbyněk; Mikuška, Pavel; Šikola, T.; Zlámal, J.

    Antverp : University of Antwerp, 2005 - (Van Grieken, R.). s. 393 [Colloquium Spectroscopicum Internationale /34./. 04.09.2005-09.09.2005, Antwerp] R&D Projects: GA AV ČR IAA400310505 Keywords : electrostatic pre-concentration * airborne particles * atomic emission spectrometric detection Subject RIV: CB - Analytical Chemistry, Separation

  13. Direct determination of lead in produced waters from petroleum exploration by electrothermal atomic absorption spectrometry X-ray fluorescence using Ir-W permanent modifier combined with hydrofluoric acid

    International Nuclear Information System (INIS)

    The present work reports the development of a methodology for the direct determination of lead in high saline waters derived from petroleum exploration employing electrothermal atomic absorption spectrometry with permanent Ir-W and HF as modifiers. These waters, so-called produced waters, have complex composition containing several types of organic and inorganic substances. In order to attain best conditions (highest analytical signal besides lowest background) for the methodology studies about the effect of several variables and the convenient calibration strategy were performed. Also, the efficiency of other modification approaches was evaluated. At best conditions, pyrolysis and atomization temperature were 800 and 2200 deg. C, respectively, when the modifiers cited above were utilized. Obtained results indicate that, in this kind of sample, lead can be determined by standard addition method or employing external calibration with standard solutions prepared in 0.8 mol l-1 NaCl medium. In order to evaluate the accuracy of the procedure, a recovery test was performed with six spiked samples of produced waters. The detection limit, quantification limit and the relative standard deviation in 0.8 mol l-1 NaCl were also calculated and the values are 1.5 μg l-1, 5.0 μg l-1 and 5.0% (at 10 μg l-1 level), respectively

  14. Direct determination of lead in produced waters from petroleum exploration by electrothermal atomic absorption spectrometry X-ray fluorescence using Ir-W permanent modifier combined with hydrofluoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Eliane P. [Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil); Santelli, Ricardo E. [Departamento de Geoquimica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil); Cassella, Ricardo J. [Departamento de Quimica Analitica, Universidade Federal Fluminense, Niteroi/RJ 24020-007 (Brazil)]. E-mail: cassella@vm.uff.br

    2005-07-22

    The present work reports the development of a methodology for the direct determination of lead in high saline waters derived from petroleum exploration employing electrothermal atomic absorption spectrometry with permanent Ir-W and HF as modifiers. These waters, so-called produced waters, have complex composition containing several types of organic and inorganic substances. In order to attain best conditions (highest analytical signal besides lowest background) for the methodology studies about the effect of several variables and the convenient calibration strategy were performed. Also, the efficiency of other modification approaches was evaluated. At best conditions, pyrolysis and atomization temperature were 800 and 2200 deg. C, respectively, when the modifiers cited above were utilized. Obtained results indicate that, in this kind of sample, lead can be determined by standard addition method or employing external calibration with standard solutions prepared in 0.8 mol l{sup -1} NaCl medium. In order to evaluate the accuracy of the procedure, a recovery test was performed with six spiked samples of produced waters. The detection limit, quantification limit and the relative standard deviation in 0.8 mol l{sup -1} NaCl were also calculated and the values are 1.5 {mu}g l{sup -1}, 5.0 {mu}g l{sup -1} and 5.0% (at 10 {mu}g l{sup -1} level), respectively.

  15. Standard methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade plutonium dioxide powders and pellets

    International Nuclear Information System (INIS)

    Various methods are described in detail as to procedure, interferences, and limits of detection or applicability for the determination of Pu and various impurities in PuO2 powders and pellets. Methods for the determination of Pu are controlled-potential coulometry, ceric sulfate titration, and amperometric titration with Fe2+. Spectrophotometric methods are given for N and S, and a direct combustion-thermal conductivity method for the determination of total C is described. A pyrohydrolysis method is described for the determination of μg amounts of Cl- and F-. A mass spectrometric determination of the Pu isotopic content of the oxide is included, and general chemical methods are included for the determination of moisture in both powders and pellets and for total gas--exclusive of moisture--in pellets. Spectrochemical methods are described for the determination of rare earths, 36 trace elements whose recommended analytical spectral lines and concentration ranges are tabulated, and impurities occurring in the atom-ppB range

  16. Standard test methods for chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 These test methods cover procedures for the chemical, mass spectrometric, and spectrochemical analysis of nuclear-grade uranium dioxide powders and pellets to determine compliance with specifications. 1.2 This test method covers the determination of uranium and the oxygen to uranium atomic ratio in nuclear-grade uranium dioxide powder and pellets. 1.4 This test method covers the determination of chlorine and fluorine in nuclear-grade uranium dioxide. With a 1 to 10-g sample, concentrations of 5 to 200 g/g of chlorine and 1 to 200 μg/g of fluorine are determined without interference. 1.5 This test method covers the determination of moisture in uranium dioxide samples. Detection limits are as low as 10 μg. 1.6 This test method covers the determination of nitride nitrogen in uranium dioxide in the range from 10 to 250 μg. 1.7 This test method covers the spectrographic analysis of nuclear-grade UO2 for the 26 elements in the ranges indicated in Table 2. 1.8 For simultaneous determination of trace ele...

  17. Aeromagnetic and gamma-ray spectrometric data interpretation for uranium exploration - south eastern margin of the Chattisgarh Basin, India

    International Nuclear Information System (INIS)

    Airborne surveys were conducted along the south-eastern margin of the Chattisgarh Basin - Singhora Basin and Sonakhan greenstone belt by the Atomic Minerals Directorate for Exploration and Research in 2000 with E-W flight lines covering 19800 linekm. Preliminary processed aeromagnetic data were corrected for IGRF, heading and lag and levelled using tie line data. Based on the amplitude, frequency and textural characteristics of enhanced magnetic images, litho-structural information of the area was deciphered. Semi-quantitative interpretation of aeromagnetic data employing Euler's technique facilitated identification of source body locations along with depth estimates. Airborne Gamma Ray Spectrometric (AGRS) data were processed for altitude attenuation, radon interference and stripping corrections. The radiometric ternary image of the processed data shows good correlation with surface geology of the area. Radiometric anomalies were extracted from the derived concentrations based on mean and standard deviation of Uranium, U/Tb and U2/Th data sets. Finally, integrated Geographical Information System (G15) analysis of inferred faults and lineaments from aeromagnetic data and uranium anomalies mapped from AGRS data were used for extracting zones favourable for uranium mineralisation. Qualitative and quantitative analysis of aeromagnetic and AGRS data and integration of the results on a GIS platform thus helped in identifying target areas for further exploration. (author)

  18. Analysis of eight argonne premium coal samples by X-ray fluorescence spectrometry

    Science.gov (United States)

    Evans, J.R.; Sellers, G.A.; Johnson, R.G.; Vivit, D.V.; Kent, J.

    1990-01-01

    X-ray fluorescence spectrometric methods were used in the analysis of eight Argonne Premium Coal Samples. Trace elements (Cr, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Ba, La, and Ce) in coal ash were determined by energy-dispersive X-ray fluorescence spectrometry; major elements (Na, Mg, Al, Si, P, S, K, Ca, Ti, Mn, and Fe) in coal ash and trace elements (Cl and P) in whole coal were determined by wavelength-dispersive X-ray fluorescence spectrometry. The results of this study will be used in a geochemical database compiled for these materials from various analytical techniques. The experimental XRF methods and procedures used to determine these major and trace elements are described.

  19. Nonclassical single-atom radiation generators

    Science.gov (United States)

    Walther, Herbert

    1990-07-01

    In this contribution quantum-effects in the radiation-atom interaction will be reviewed. It is well known that most of the phenomena involving laser light can be described by semi-classical methods however phenomena such as laser noise the spectra and photon statistics of resonance fluorescence and the interaction of atoms in the single-atom maser require a quantization of the radiation field. In this paper we will describe results on the latter two effects. We will start with the discussion of resonance fluorescence. 1. RESONANCE FLUORESCENCE The resonant interaction of laser light with atomic systems has received considerable theoretical and experimental attention over the past decade. Until the advent of the laser light sources for spectroscopy consisted of ordinary spectral lamps excited by DC or RF discharges and produced light having a very broad spectral width and hence very short correlation time and a relatively low intensity. For such fields both the experimental and theoretical results are in general well understood. However the development of the laser made available light sources which are sufficiently intense that an atomic (or molecular) transition can be very easily saturated. In addition the lasers are highly monochromatic having a coherence time much greater than typical natural lifetimes of excited atomic states and finally tunable making it possible to selectively excite particular atomic transitions. The theoretical analysis of this physical situation requires the use of techniques more general than

  20. Monitoring of the gadolinium photoionization process by using fluorescence measurements

    International Nuclear Information System (INIS)

    The population dynamics in a resonant three-photon ionization process of the gadolinium (Gd) atom is experimentally studied by investigating ion signals and fluorescence signals. We detect the ion signals by using a time-of-flight mass spectrometer, and at the same time, we probe the fluorescence coming out of the excited states involved in the ionization process. The number of residual atoms that remain in excited states after the laser beams have passed is estimated by measuring the variation of the fluorescence signal. Since this information is directly related to how many atoms are not ionized, we can use this method for monitoring the ionization process. Using this method, we estimate the ionization efficieny of the Gd atom

  1. Determination of Trace Tin in Multimetal Ore by Hydride Generation Atomic Fluorescence Spectrometry%HG-AFS 法测定多金属矿中的痕量锡

    Institute of Scientific and Technical Information of China (English)

    艾军; 周俊明

    2001-01-01

    研究了酒石酸介质中氢化物发生原子荧光光谱法(HG-AFS)测定多金属矿中痕量锡的方法,考察了不同酸介质和浓度对氢化物发生效率的影响,试验了共存元素的干扰情况。方法的检出限为1.4×10-10g/mL,精密度(n=5)为3.71%~5.38%。%A method for determination of trace Sn by hydride generationatomic fluorescence spectrometry (HG-AFS) was described. The influence of HG-AFS operation conditions,various acidic media and concentration of NaBH4 solution was studied.The detection limit is 1.4×10-10 g/mL. The method was applied to determination of trace Sn in the standard multimetal ore samples. The results were in good agreement with certifid values with precision of 3.7%~5.4% RSD(n=5).

  2. Laser-induced spectrometric techniques to investigate the speciation of Eu in organic media

    International Nuclear Information System (INIS)

    Laser-induced spectrometric techniques provide both selectivity and sensitivity. The extremely low detection limits are ideal for assessing the extraction mechanisms involved in enhanced reprocessing applications through detailed speciation studies. Although time-resolved laser-induced fluorescence spectroscopy (TRLIF) is one of the most sensitive spectroscopy techniques, with the optical spectrum and its lifetime constituting two sources of data, it is limited to a few fluorescing actinides and lanthanides. This drawback warrants the development of an additional, complementary spectroscopic system with greater sensitivity than UV-Visible-near IR absorptiometry, based on measuring the pressure wave caused by the deexcitation of non-fluorescing species. Laser-induced photoacoustic spectroscopy (LIPAS) is based on measuring the characteristics of the pressure wave emitted during non-radiative relaxation of the absorbed energy. This speciation technique should allow investigation of compounds that absorb in the UV-visible range and are present at low concentrations in solution. It provides data on the nature and concentration of the species, including its oxidation, complexation and even colloidal states. The two techniques with a common laser source OPO were recently installed at Marcoule. TRLIF speciation studies are generally based on analyzing modifications in the fluorescence spectrum following a short laser pulse. They are related to the characteristic spectral pattern and relaxation rate of each species in solution. In the particular case of fluorescent decay of trivalent Am, Cm, Sm, Eu, Tb and Dy ions, the metallic cation deexcitation constant is closely related to the number of water molecules in the primary coordination sphere. This property helps to obtain more information on the structure around the metal ion. The first study was an investigation of the complexation of Eu(III) by TEMA (N, N'-tetra-ethyl-malonamide (C2H5)2NCO-CH2CON(C2H5)2) in the aqueous

  3. QuEChERS sample preparation approach for mass spectrometric analysis of pesticide residues in foods

    Science.gov (United States)

    This chapter describes an easy, rapid, and low-cost sample preparation approach for the determination of pesticide residues in foods using gas and/or liquid chromatographic (GC and/or LC) analytical separation and mass spectrometric (MS) detection. The approach is known as QuEChERS, which stands fo...

  4. X-ray spectrometric determination of thorium in bone and other biological materials

    International Nuclear Information System (INIS)

    An x-ray spectrometric method has been developed for the determination of thorium in bone and other biological materials. The limit of detection at the 95% confidence level is 20 ng. This corresponds to a concentration of 2 ppb in a 10-g sample of bone ash

  5. Atomic secrecy

    International Nuclear Information System (INIS)

    An article, The H-Bomb Secret: How We Got It, Why We're Telling It, by Howard Morland was to be published in The Progressive magazine in February, 1979. The government, after learning of the author's and the editors' intention to publish the article and failing to persuade them to voluntarily delete about 20% of the text and all of the diagrams showing how an H-bomb works, requested a court injunction against publication. Acting under the Atomic Energy Act of 1954, US District Court Judge Robert W. Warren granted the government's request on March 26. Events dealing with the case are discussed in this publication. Section 1, Progressive Hydrogen Bomb Case, is discussed under the following: Court Order Blocking Magazine Report; Origins of the Howard Morland Article; Author's Motives, Defense of Publication; and Government Arguments Against Disclosure. Section 2, Access to Atomic Data Since 1939, contains information on need for secrecy during World War II; 1946 Atomic Energy Act and its effects; Soviet A-Bomb and the US H-Bomb; and consequences of 1954 Atomic Energy Act. Section 3, Disputed Need for Atomic Secrecy, contains papers entitled: Lack of Studies on H-Bomb Proliferation; Administration's Position on H-Bombs; and National Security Needs vs Free Press

  6. Continuous magnetic trapping of laser cooled atoms

    International Nuclear Information System (INIS)

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

  7. Atomic theories

    CERN Document Server

    Loring, FH

    2014-01-01

    Summarising the most novel facts and theories which were coming into prominence at the time, particularly those which had not yet been incorporated into standard textbooks, this important work was first published in 1921. The subjects treated cover a wide range of research that was being conducted into the atom, and include Quantum Theory, the Bohr Theory, the Sommerfield extension of Bohr's work, the Octet Theory and Isotopes, as well as Ionisation Potentials and Solar Phenomena. Because much of the material of Atomic Theories lies on the boundary between experimentally verified fact and spec

  8. Analysis of spectrometric optical data from different devices

    Science.gov (United States)

    Borisova, D.; Petkov, D.

    2014-10-01

    following spectrometric systems: SRM, 0.4-0.82 micrometers; SPS-1, 0.55-1.1 micrometers, Thematically Oriented Multi-channel Spectrometer /TOMS/, 0.4-0.9 micrometers, all of them designed and constructed in Remote Sensing Systems /RSS/ Department at SRTI-BAS. The obtained spectral data are compared with similar data from different instruments for Earth observation included in the spectral libraries. They correspond to the shape of the spectral signature in the same spectral range obtained with other spectrometers. Two wavelengths were selected and were applied for the proper comparison between the data obtained by different instruments. The dependence between the reflectance values at the chosen wavelengths and the quantitative content of the rock-forming minerals was established. The achieved results proved that this methodology could be applied for comparing the spectral data from different sources. These promising results encourage us to plan the next campaigns for the field spectroscopy measurements in different regions of Bulgaria.

  9. Analysis of tungsten carbides by X-ray fluorescence spectrometry.

    Science.gov (United States)

    Kinson, K; Knott, A C; Belcher, C B

    Five sample presentation techniques were examined for the X-ray fluorescence spectrometric analysis of tungsten carbide alloys in powder and cemented forms. Powder samples may be oxidized by air at 600 degrees before fusion (I), or preferably by lithium nitrate during fusion (II); the fusion is effected with lithium-lanthanum tetraborate followed by briquetting with graphite. Powder samples may also be blended with wax and briquetted (III). Cemented carbides are surface-prepared with silicon carbide before analysis (V). Briquettes prepared by blending carbide powder, lithium-lanthanum tetraborate and graphite (IV), give poor reproducibility, however, owing to micro-absorption effects the technique is not recommended. The determination of eight common elements in tungsten carbide is discussed and the relative standard deviations are 0.002-0.004 for major and 0.008-0.01 for minor elements. PMID:18961988

  10. Atoms as Qed bound atoms

    International Nuclear Information System (INIS)

    The relevance of Quantum Electrodynamics (Qed) in contemporary atomic structure theory is reviewed. Recent experimental advances allow both the production of heavy ions of high charge as well as the measurement of atomic properties with a precision never achieved before. The description of heavy atoms with few electrons via the successive incorporation of one, two, etcetera photons in a rigorous manner and within the bound state Furry representation of Qed is technically feasible. For many-electron atoms the many-body (correlation) effects are very important and it is practically impossible to evaluate all the relevant Feynman diagrams to the required accuracy. Thus, it is necessary to develop a theoretical scheme in which the radiative and nonradiative effects are taken into account in an effective way making emphasis in electronic correlation. Preserving gauge invariance, and avoiding both continuum dissolution and variational collapse are basic problems that must be solved when using effective potential methods and finite-basis representations of them. In this context, we shall discuss advances and problems in the description of atoms as Qed bound states. (Author)

  11. Microwave Power Standard using Cold Atoms

    CERN Document Server

    Paulusse, D C; Michaud, A; Paulusse, David C; Rowell, Nelson L; Michaud, Alain

    2003-01-01

    We discuss how the observation of Rabi flopping oscillations in a laser cooled atomic sample could be used as a microwave power standard. The rubidium atoms are first trapped in a standard MOT, then optically pumped, and dropped. As they enter the interaction region, a resonant pulsed microwave field is applied. Following the interaction lasting up to 10 ms, a probe laser beam is turned on and the fluorescence measures the population inversion.

  12. Localization of atomic ensembles via superfluorescence

    OpenAIRE

    Macovei, M.; Evers, J.; Keitel, C. H.; Zubairy, M. S.

    2006-01-01

    The sub-wavelength localization of an ensemble of atoms concentrated to a small volume in space is investigated. The localization relies on the interaction of the ensemble with a standing wave laser field. The light scattered in the interaction of standing wave field and atom ensemble depends on the position of the ensemble relative to the standing wave nodes. This relation can be described by a fluorescence intensity profile, which depends on the standing wave field parameters, the ensemble ...

  13. 流动注射在线离子交换分离富集-氢化物发生原子荧光光谱法测定铜合金中痕量锑%Determination of trace antimony in copper alloys by flow injection on-line ion-exchange separation and enrichment-hydride generation atomic fluorescence spectrometry

    Institute of Scientific and Technical Information of China (English)

    吴良俊; 邱海鸥; 郝志红; 袁红战; 郑洪涛

    2009-01-01

    A method for the determination of trace antimony in copper by flow injection on-line ion-exchange separation and enrichment-hydride generation atomic fluorescence spectrometry is suggested. The manifolds and operating program for ftlow injection on-line ion-exchange were designed and chemical conditions were optimized. Antimony complex was absorbed on strongly basic anion exchange resin 717 with 1. 4 mol/L HC1 as absorbent medium and 2. 0 mol/L HNO_3 for elution. The interference of co-existent elements (i-ron, nickel, lead, etc) was eliminated while antimony was enriched and was determined by hydride generation-atomic fluorescence spectrometry. The method is easy to operate and fast, and has lesser pollution to environment. The linear range is 0. 2-120μg/L and the RSD is 3%~5% with detection limit of 0. 05 μg/L. The results for determination of antimony in standard samples of copper alloys are satisfactory.%提出了流动注射离子交换在线分离富集-氢化物发生原子荧光光谱法测定铜合金中痕量锑的分析方法.设计了流动注射在线离子交换的流路和操作程序,优化了各项化学条件.采用717强碱性阴离子交换树脂吸附锑,并能有效消除铁、镍、铅等元素的干扰,也使大量基体元素铜与待测元素分离,锑在1.4 mol/L的HCl介质中上柱,选用2.0 mol/L的HNO_3作为洗脱剂.实现了氢化物发生原子荧光光谱法对铜合金中痕量锑的在线测定.方法操作简便、快速,环境污染小,线性范围为0.15~120 μg/L,相对标准偏差在3%~5%之间,检出限为0.05μg/L.方法应用于铜合金标准样品,结果与推荐值吻合.

  14. Interaction of norfloxacin with bovine serum albumin studied by different spectrometric methods; displacement studies, molecular modeling and chemometrics approaches

    Energy Technology Data Exchange (ETDEWEB)

    Naseri, Abdolhossein, E-mail: a_naseri@tabrizu.ac.ir [Departments of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51666-16471 (Iran, Islamic Republic of); Hosseini, Soheila [Departments of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz 51666-16471 (Iran, Islamic Republic of); Rasoulzadeh, Farzaneh [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz 51644-14766 (Iran, Islamic Republic of); Rashidi, Mohammad-Reza [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz 51644-14766 (Iran, Islamic Republic of); Zakery, Maryam; Khayamian, Taghi [Department of Chemistry, College of Chemistry, Isfahan University of Technology, Isfahan 84154 (Iran, Islamic Republic of)

    2015-01-15

    Serum albumins as major target proteins can bind to other ligands leading to alteration of their pharmacological properties. The mechanism of interaction between norfloxacin (NFLX) with bovine serum albumin (BSA) was investigated. Fuorescence quenching of serum albumin by this drug was found to be a static quenching process. The binding sites number, n, apparent binding constant, K, and thermodynamic parameters were calculated at different temperatures. The distance, r, between donor, BSA, and acceptor, NFLX, was calculated according to the Forster theory of non-radiation energy transfer. Also binding characteristics of NFLX with BSA together with its displacement from its binding site by kanamycin and effect of common metal ions on binding constant were investigated by the spectroscopic methods. The conformational change in the secondary structure of BSA upon interaction with NFLX was investigated qualitatively from synchronous fluorescence spectra, Fourier Transform Infrared (FTIR) and circular dichroism (CD) spectrometric methods. Molecular docking studies were performed to obtain information on the possible residues involved in the interaction process and changes in accessible surface area of the interacting residues. The results showed that the conformation of BSA changed in the presence of NFLX. For the first time, displacement studies were used for this interaction; displacement studies showed that NFLX was displaced by phenylbutazon and ketoprofen but was not displaced by ibuprofen indicating that the binding site of NFLX on albumin was site I. In addition a powerful chemometrics method, multivariate curve resolution-alternating least square, was used for resolution of spectroscopic augmented data obtained in two different titration modes in order to extract spectral information regardless of spectral overlapping of components. - Highlights: • Interaction between norfloxacin and BSA is studied by spectral methods. • Chemometrics methods are used to

  15. Interaction of norfloxacin with bovine serum albumin studied by different spectrometric methods; displacement studies, molecular modeling and chemometrics approaches

    International Nuclear Information System (INIS)

    Serum albumins as major target proteins can bind to other ligands leading to alteration of their pharmacological properties. The mechanism of interaction between norfloxacin (NFLX) with bovine serum albumin (BSA) was investigated. Fuorescence quenching of serum albumin by this drug was found to be a static quenching process. The binding sites number, n, apparent binding constant, K, and thermodynamic parameters were calculated at different temperatures. The distance, r, between donor, BSA, and acceptor, NFLX, was calculated according to the Forster theory of non-radiation energy transfer. Also binding characteristics of NFLX with BSA together with its displacement from its binding site by kanamycin and effect of common metal ions on binding constant were investigated by the spectroscopic methods. The conformational change in the secondary structure of BSA upon interaction with NFLX was investigated qualitatively from synchronous fluorescence spectra, Fourier Transform Infrared (FTIR) and circular dichroism (CD) spectrometric methods. Molecular docking studies were performed to obtain information on the possible residues involved in the interaction process and changes in accessible surface area of the interacting residues. The results showed that the conformation of BSA changed in the presence of NFLX. For the first time, displacement studies were used for this interaction; displacement studies showed that NFLX was displaced by phenylbutazon and ketoprofen but was not displaced by ibuprofen indicating that the binding site of NFLX on albumin was site I. In addition a powerful chemometrics method, multivariate curve resolution-alternating least square, was used for resolution of spectroscopic augmented data obtained in two different titration modes in order to extract spectral information regardless of spectral overlapping of components. - Highlights: • Interaction between norfloxacin and BSA is studied by spectral methods. • Chemometrics methods are used to

  16. Dielectrophoretic immobilization of proteins: Quantification by atomic force microscopy.

    Science.gov (United States)

    Laux, Eva-Maria; Knigge, Xenia; Bier, Frank F; Wenger, Christian; Hölzel, Ralph

    2015-09-01

    The combination of alternating electric fields with nanometer-sized electrodes allows the permanent immobilization of proteins by dielectrophoretic force. Here, atomic force microscopy is introduced as a quantification method, and results are compared with fluorescence microscopy. Experimental parameters, for example the applied voltage and duration of field application, are varied systematically, and the influence on the amount of immobilized proteins is investigated. A linear correlation to the duration of field application was found by atomic force microscopy, and both microscopical methods yield a square dependence of the amount of immobilized proteins on the applied voltage. While fluorescence microscopy allows real-time imaging, atomic force microscopy reveals immobilized proteins obscured in fluorescence images due to low S/N. Furthermore, the higher spatial resolution of the atomic force microscope enables the visualization of the protein distribution on single nanoelectrodes. The electric field distribution is calculated and compared to experimental results with very good agreement to atomic force microscopy measurements. PMID:26010162

  17. Total reflection X-ray fluorescence spectrometric determination of elements in water hyacinth from the Lerma River

    International Nuclear Information System (INIS)

    The Lerma River is one of the most polluted body water in Mexico. For this reason, only the highly resistant organisms such as water hyacinth are able to reproduce in this river. The aim of this work was to evaluate the concentration of K, S, Fe, Ca, Mn, Ti, Zn, Sr, Rb, Cu, Cr, Ni, Pb and Br in roots of water hyacinth (Eichhornia crassipes) from the Lerma River. The samples were collected from five sites in the river and analyzed in triplicate using a TXRF Spectrometer 'TX-2000 Ital Structures' with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα. A Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy was used for a counting time of 500 s. Results show that the average metal concentration in the water hyacinth roots decrease in the following order: K (9698.2 μg/g) > S (7593.3 μg/g) > Fe (4406.6 μg/g) > Ca (2601.8 μg/g) > Mn (604.2 μg/g) > Ti (230.7 μg/g) > Zn (51.65 μg/g) > Sr (43.55 μg/g) > Rb (18.61 μg/g) > Cu (12.78 μg/g) > Cr (6.45 μg/g) > Ni (4.68 μg/g) > Pb (4.32 μg/g) > Br (4.31 μg/g) and the bioconcentration factors in the water hyacinth decrease in the sequence: Ti > Fe > Mn > Cu > Ni > Zn > S > Pb > Rb > K > Cr > Sr > Br > Ca. The concentrations in roots of water hyacinth reflect the high pollution level of the river.

  18. Total reflection X-ray fluorescence spectrometric determination of elements in water hyacinth from the Lerma River

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda, S. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Instituto Tecnologico de Toluca, Division de Estudios de Posgrado e Investigacion, Apartado Postal 890, Metepec, C.P. 52149 (Mexico); Zarazua, G., E-mail: graciela.zarazua@inin.gob.m [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Avila-Perez, P. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Instituto Tecnologico de Toluca, Division de Estudios de Posgrado e Investigacion, Apartado Postal 890, Metepec, C.P. 52149 (Mexico); Carapia-Morales, L. [Instituto Nacional de Investigaciones Nucleares, Gerencia de Ciencias Ambientales, Apartado Postal 18-1027, Mexico D.F., C.P. 11801 (Mexico); Martinez, T. [Universidad Nacional Autonoma de Mexico, Facultad de Quimica, Mexico D.F. (Mexico)

    2010-06-15

    The Lerma River is one of the most polluted body water in Mexico. For this reason, only the highly resistant organisms such as water hyacinth are able to reproduce in this river. The aim of this work was to evaluate the concentration of K, S, Fe, Ca, Mn, Ti, Zn, Sr, Rb, Cu, Cr, Ni, Pb and Br in roots of water hyacinth (Eichhornia crassipes) from the Lerma River. The samples were collected from five sites in the river and analyzed in triplicate using a TXRF Spectrometer 'TX-2000 Ital Structures' with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn K{alpha}. A Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy was used for a counting time of 500 s. Results show that the average metal concentration in the water hyacinth roots decrease in the following order: K (9698.2 {mu}g/g) > S (7593.3 {mu}g/g) > Fe (4406.6 {mu}g/g) > Ca (2601.8 {mu}g/g) > Mn (604.2 {mu}g/g) > Ti (230.7 {mu}g/g) > Zn (51.65 {mu}g/g) > Sr (43.55 {mu}g/g) > Rb (18.61 {mu}g/g) > Cu (12.78 {mu}g/g) > Cr (6.45 {mu}g/g) > Ni (4.68 {mu}g/g) > Pb (4.32 {mu}g/g) > Br (4.31 {mu}g/g) and the bioconcentration factors in the water hyacinth decrease in the sequence: Ti > Fe > Mn > Cu > Ni > Zn > S > Pb > Rb > K > Cr > Sr > Br > Ca. The concentrations in roots of water hyacinth reflect the high pollution level of the river.

  19. Total reflection X-ray fluorescence spectrometric determination of elements in water hyacinth from the Lerma River

    Science.gov (United States)

    Tejeda, S.; Zarazúa, G.; Ávila-Pérez, P.; Carapia-Morales, L.; Martínez, T.

    2010-06-01

    The Lerma River is one of the most polluted body water in Mexico. For this reason, only the highly resistant organisms such as water hyacinth are able to reproduce in this river. The aim of this work was to evaluate the concentration of K, S, Fe, Ca, Mn, Ti, Zn, Sr, Rb, Cu, Cr, Ni, Pb and Br in roots of water hyacinth ( Eichhornia crassipes) from the Lerma River. The samples were collected from five sites in the river and analyzed in triplicate using a TXRF Spectrometer 'TX-2000 Ital Structures' with a Si(Li) detector and a resolution of 140 eV (FWHM) at Mn Kα. A Mo tube (40 kV, 30 mA) with 17.4 KeV excitation energy was used for a counting time of 500 s. Results show that the average metal concentration in the water hyacinth roots decrease in the following order: K (9698.2 µg/g) > S (7593.3 µg/g) > Fe (4406.6 µg/g) > Ca (2601.8 µg/g) > Mn (604.2 µg/g) > Ti (230.7 µg/g) > Zn (51.65 µg/g) > Sr (43.55 µg/g) > Rb (18.61 µg/g) > Cu (12.78 µg/g) > Cr (6.45 µg/g) > Ni (4.68 µg/g) > Pb (4.32 µg/g) > Br (4.31 µg/g) and the bioconcentration factors in the water hyacinth decrease in the sequence: Ti > Fe > Mn > Cu > Ni > Zn > S > Pb > Rb > K > Cr > Sr > Br > Ca. The concentrations in roots of water hyacinth reflect the high pollution level of the river.

  20. Photon-induced fluorescence spectroscopy (PIFS)

    CERN Document Server

    Schmoranzer, H; Vollweiler, F; Müller-Albrecht, R; Ehresmann, A; Schartner, K H; Zimmermann, B

    2001-01-01

    Photon-induced fluorescence spectroscopy (PIFS) using monochromatized synchrotron radiation for exciting the sample selectively and a fluorescence spectrometer with a position-sensitive photon detector for recording its fluorescence spectrum is a very powerful experimental technique especially for the investigation of atomic and molecular photoionization and photodissociation. To reduce the contributions of higher harmonics of the undulator radiation which are also transmitted through the primary monochromator a very compact He absorber was developed. With a He pressure of 30 mbar in the differentially pumped gas cell of the absorber the fraction of the third harmonic of the undulator transmitted through the monochromator was reduced by a factor of 175 for an exciting-photon energy of the first order of 24.18 eV.