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Sample records for atomic absorption technique

  1. Use of Atomic Absorption Technique in Environmental Studies

    International Nuclear Information System (INIS)

    This chapter consists of some points including the process of atomic absorption, historical hint, key basics, the atom ionization and formation of plasma, applications in the device of atomic absorption, quantum analysis with atomic absorption, components of the device of atomic absorption, standardization of this device, atomic absorption in the the graphite furnace, supervising the analytical interventions, spectral interventions, non-spectral interventions, the utmost electric energy for atomization, preparation of standards and samples, the system of acidic digestion, similar analytical techniques.

  2. High sensitivity probe absorption technique for time-of-flight measurements on cold atoms

    Indian Academy of Sciences (India)

    A K Mohapatra; C S Unnikrishnan

    2006-06-01

    We report on a phase-sensitive probe absorption technique with high sensitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms. We demonstrate the high sensitivity and figure of merit of the simple method by measuring the time-of-flight of atoms moving upwards from a magneto-optical trap released in the gravitational field.

  3. Normal blood magnesium levels in volunteers of Rawalpindi by atomic absorption absorption technique

    International Nuclear Information System (INIS)

    Magnesium levels in whole blood samples of 67 healthy volunteers (mean 6.46 -+ 0.221; range 1.345 - 13.163 mg/dL) of Rawalpindi district have been determined by flame atomic absorption spectrophotometric method. Magnesium levels of 41 male and 26 female subjects including doctors, nurses, patients attendees, medical students, sweepers and peons of Rawalpindi Medical College and Rawalpindi General Hospital revealed the normal mean blood levels of 6.088 - + 0.258 mg/dL (range 1.345 - 10.679 mg/dL)and 7.060 -+ 0.375 mg/dL (range 4.495 - 13.163 mg/dL),P<0.05 respectively. Only 10 male volunteers were smokers exhibiting 6.768 -+ 0.558 mg/dL (range 4.466 -10.679 mg/dL). Significant relationship was found in magnesium levels between males and females of poor socio-economic group (P<0.05). No relationship occurred between male smokers and non-smokers and magnesium levels in the age groups of males or females or both, when data was compared by 't' test. (author)

  4. Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    A new method of background correction in atomic absorption spectroscopy has recently been introduced, based on the Zeeman splitting of spectral lines in a magnetic field. A theoretical analysis of the background correction capability observed in such instruments is presented. A Zeeman atomic absorption spectrometer utilizing a 50 Hz sine wave modulated magnetic field is described. (Auth.)

  5. Monitoring heavy metals pollution in Bandar Emam region by using atomic absorption technique

    International Nuclear Information System (INIS)

    The level and distribution of five heavy metals Ni, V, Cr, Pb, and Cd in the sediments waters of three areas Bandar Emam were investigated by the use of atomic absorption technique. Metals have been analyzed for different grain size fractions. These metals levels in sediment are expressed as μgg4+ and metal level in water is expressed as ppm. The concentrations of the elements under investigation is much higher than the concentrations of these elements and these of mean in sediments and waters which were compared with the concentration of these elements in the earth crust and international atomic energy agency and ICRP standards. Significant variations in the level of these metals were considered due to: atmospheric fall out as well as waste waters disposal and anthropogenic inputs, Ni and V were due to non-anthropogenic sources and analysis indicate that the sources of Cr and Cd are mainly oil pollution. High level of lead was considered due to inputs from oil discarded solid waters and the prior high rate petrol combustion lead. Monitoring water and sediments, in other words periodic or continuous determination of the amounts of ionizing radiation in water and sediments is one of the positive steps against the pollution in these regions

  6. Zeeman atomic absorption spectrometry

    International Nuclear Information System (INIS)

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

  7. Comparative studies of method for determining total mercury in fish. Dithizone and flameless atomic absorption spectrophotometry techniques

    International Nuclear Information System (INIS)

    Two methods for determining total mercury in fish were compared: the dithizone and flameless atomic absorption spectrophotometry techniques. The studies involved determination of recovery when 1μg of mercury as solutions of HgCl2 or CH3HgC were added to each sample of herring flesh. Mean recoveries in the dithizone method were found to be 91.4+-7.47% and 90.25+-4.73% for the two solutions respectively, while the recoveries obtained with the flameless atomic absorption spectrophotometry were 95.00+-9.13% and 98.70+-7.14%, respectively. Both techniques were used to determine the mercury content in the same herring flesh sample. The first technique showed the content of 0.050+-0.018μg Hg g-1 while the result obtained with the other one was 0.062+-0.013μg Hg g-1. The statistical treatment of the results obtained showed no difference between the two techniques, the significance level being α=0.05. Therefore, the results obtained with the dithizone method are comparable with those obtained with the flameless atomic absorption spectrophotometry for mercury contents of the magnitude order of 0.050 ug.g-1. (author)

  8. Graphite filter atomizer in atomic absorption spectrometry

    Science.gov (United States)

    Katskov, Dmitri A.

    2007-09-01

    Graphite filter atomizers (GFA) for electrothermal atomic absorption spectrometry (ETAAS) show substantial advantages over commonly employed electrothermal vaporizers and atomizers, tube and platform furnaces, for direct determination of high and medium volatility elements in matrices associated with strong spectral and chemical interferences. Two factors provide lower limits of detection and shorter determination cycles with the GFA: the vaporization area in the GFA is separated from the absorption volume by a porous graphite partition; the sample is distributed over a large surface of a collector in the vaporization area. These factors convert the GFA into an efficient chemical reactor. The research concerning the GFA concept, technique and analytical methodology, carried out mainly in the author's laboratory in Russia and South Africa, is reviewed. Examples of analytical applications of the GFA in AAS for analysis of organic liquids and slurries, bio-samples and food products are given. Future prospects for the GFA are discussed in connection with analyses by fast multi-element AAS.

  9. Determination of metallic elements in water by the combined preconcentration techniques of ion exchange and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Having as an aim the utilization of atomic absorption method with flame's excitement, the limits of detection in water of six metals (Ag, Co, Cr, Cu, Ni, Zn) were determined in synthetical samples through atomic absorption spectroscopy. Techniques to optimize the data have been pointed out and presented their statistical treatment. By means of the routine and the addition methods three 'real' samples have also been analysed in order to determine the contents of Cu and Zn. Aiming a pre-concentration and by utilizing the 60Co obtained activating a sample of cobalt in the CDTN/NUCLEBRAS TRIGA MARK-I reactor, the retainement of this cobalt in ion exchange resin and the variation of the factor of elution within different concentration of HCl in water have been determined. The limits of detection are presented and so are the quantitative ones, with and without pre-concentration in an ion exchanger resin and latter elution. (Author)

  10. Lead and cadmium determinations by atomic absorption technique in biological samples: blood, placenta and umbilical cord

    International Nuclear Information System (INIS)

    In order to determine the possibility contamination of lead and cadmium in pregnant women living in the mining-smelting city of La Oroya in Peru, lead and cadmium concentrations were assessed in maternal blood (pre-birth), umbilical cord blood and placental tissue. Forty deliveries with normal evolution were evaluated between October 2002 and January 2003. Samples were analyzed by atomic absorption on a graphite furnace at the Peruvian Institute of Nuclear Energy (IPEN) laboratories. Results are summarized as follows: a) Mean lead concentrations in maternal blood (MB), umbilical cord blood (UCB) and placental tissue (PT) were 27.23 μg/dL, 18.48 μg/dL and 363.97 μg/100g, respectively; b) Mean cadmium concentrations in MB, UCB and PT were 8.82 μg/dL, 12,0 μg/dL and 104,44 μg/100g, respectively; c) The correlation coefficient between lead concentration in maternal blood and umbilical cord was 0.122; d). The correlation coefficient of cadmium concentration between MB and UCB was 0.223; e). The correlation coefficient of lead concentration between MB and PT was 0.189; f). The correlation coefficient of cadmium concentration between MB and PT was 0.633. Trans-placental transport of lead was 67.84% (27,23 μg/dL in MB vs. 18.48 μg/dL in UCB); whereas in the case of cadmium, the concentration in UC (12,00 μg/dL) was greater than in MB (8.82 μg/dL.). These results could indicate that the placenta acts as a barrier trapping lead and cadmium. This barrier is efficient for lead since the concentration in cord blood is inferior to maternal blood but it is less efficient for cadmium. (author)

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

    International Nuclear Information System (INIS)

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

  12. 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,…

  13. Hot tube atomic absorption spectrochemistry.

    Science.gov (United States)

    Woodriff, R; Stone, R W

    1968-07-01

    A small, commercially available atomic absorption instrument is used with a heated graphite tube for the atomic absorption analysis of liquid and solid silver samples. Operating conditions of the furnace are described and a sensitivity of about 5 ng of silver is reported. PMID:20068797

  14. Evaluation of various techniques for the pretreatment of sewage sludges prior to trace metal analysis by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Six techniques were evaluated for their suitability for the pretreatment of dried sewage sludge prior to trace metal analysis by atomic absorption spectrophotometry. The evaluation comprised analysis of two prepared samples of dried sludge for aluminium, cadmium, chromium, copper, iron, lead, manganese, nickel and zinc, after the following pretreatment: dry ashing at 500 degrees Celsius followed by extraction with dilute hydrochloric acid; dry ashing at 500 degrees Celsius followed by extraction with aqua regia; nitric acid digestion followed by extraction with hydrochloric acid; extraction with aqua regia; ashing with magnesium nitrate solution at 550 degrees Celsius followed by digestion with hydrochloric acid and extraction with nitric acid; extraction with nitric acid. Procedures involving the use of perchloric acid, hydrofluoric acid and hydrogen peroxide were not considered for reasons of safety. Except in the case of aluminium the direct mineral acid digestion and/or extraction methods generally gave higher recoveries than the procedures incorporating an ashing step. Direct extraction of the sample with aqua regia was recommended as a rapid and simple general method of sample pretreatment prior to analysis for all the metals investigated except aluminium. For this metal, more drastic sample pretreatment will be required, for example fusion or hydrofluoric acid digestion

  15. Absorption properties of identical atoms

    Energy Technology Data Exchange (ETDEWEB)

    Sancho, Pedro, E-mail: psanchos@aemet.es

    2013-09-15

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas. -- Highlights: •The absorption rates of a pair of identical atoms in product and (anti)symmetrized states are different. •The modifications of the optical properties are essentially determined by the overlapping between the atoms. •The absorption properties differ, in some cases, for bosons and fermions.

  16. Comparative investigation of sample preparation techniques for atomic-absorption determination of copper, nickel, cadmium in wood flour

    International Nuclear Information System (INIS)

    Comparative study of two methods of sample preparation (acid decomposition and dry calculation) for atomic-absorption content of copper, nickel and cadmium in wood flour, has been conducted. It is shown that for a certain content of copper and nickel (from 6 to 40 μg/g) it is recommended that the method of dry calcination is used, for cadmium determination (its content being 1-2 μg/g) both methods are applicable

  17. Absorption properties of identical atoms

    OpenAIRE

    Sancho, Pedro

    2013-01-01

    Emission rates and other optical properties of multiparticle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas.

  18. Absorption properties of identical atoms

    Science.gov (United States)

    Sancho, Pedro

    2013-09-01

    Emission rates and other optical properties of multi-particle systems in collective and entangled states differ from those in product ones. We show the existence of similar effects in the absorption probabilities for (anti)symmetrized states of two identical atoms. The effects strongly depend on the overlapping between the atoms and differ for bosons and fermions. We propose a viable experimental verification of these ideas.

  19. Assessment of elemental pollution in soil of Islamabad city using instrumental neutron activation analysis and atomic absorption spectrometry techniques

    Energy Technology Data Exchange (ETDEWEB)

    Daud, M.; Wasim, M.; Khalid, N.; Zaidi, J.H. [Pakistan Institute of Nuclear Science and Technology, Islamabad (Pakistan). Chemistry Div.; Iqbal, J. [University of the Punjab, Lahore (Pakistan). Inst. of Chemistry

    2009-07-01

    The soil samples of nine different sites in Islamabad were studied for their elemental composition. Instrumental neutron activation analysis and atomic absorption spectrometry were employed and 33 elements were determined. The acquired data were analyzed using descriptive statistics, principal component analysis, cluster analysis, pollution level index and enrichment factor. A perusal of results shows a distribution of elemental concentration in two major groups, one along the highway and the other in industrial area of Islamabad. The soil along the highway sites was found to be relatively less polluted than at the sites in the industrial area. The enrichment factor indicates the presence of As, Pb, Sb, Se and Sn at higher levels. The method validation was done by analyzing IAEA reference materials SL-1 (lake sediment) and S7 (soil). (orig.)

  20. Atomic absorption analysis of serial titanium alloys

    International Nuclear Information System (INIS)

    Atom-absorption technique is described, which makes it possible to rapidly and precisely determine the following alloying elements and admixtures in titanium alloys: Al (2.0 - 8.5%); Mo (0.5 - 8%); Cr (0.5 - 12%); Si (0.2 - 0.5%); Mn(0.2 - 2.5%); V(0.5 - 6%); Sn(2.0 - 3.0%); Fe(0.1 - 1.0%); Zr(2.0 - 12.0%). The atom absorption method with flame atomization of the sample provides for best results if the alloy is dissolved in a mixture HCl + HBF4 in the ratio 2:1. In order to obtain correct results the standard solutions must contain titanium in concentrations corresponding to the weight of the sample being analyzed. Sensitivity of zirconium determination may be increased approximately twofold by adding 10 mg/ml of FeCl3 into the solution. Being as precise, as the classic analytical methods, the atom absorption technique is about 5 times more efficient

  1. A method optimization study for atomic absorption spectrophotometric determination of total zinc in insulin using direct aspiration technique

    Directory of Open Access Journals (Sweden)

    Sadia Ata

    2015-03-01

    Full Text Available A sensitive, reliable and relative fast method has been developed for the determination of total zinc in insulin by atomic absorption spectrophotometer. This designed study was used to optimize the procedures for the existing methods. Spectrograms of both standard and sample solutions of zinc were recorded by measuring the absorbance at 213.9 nm for determination of total zinc. System suitability parameters were evaluated and were found to be within the limits. Linearity was evaluated through graphical representation of concentration versus absorbance. Repeatability (intra-day and intermediate precision (inter-day were assessed by analyzing working standard solutions. Accuracy and robustness were experimented from the standard procedures. The percentage recovery of zinc was found to be 99.8%, relative standard deviation RSD 1.13%, linearity of determination LOD 0.0032 μg/mL, and limit of quantization LOQ 0.0120 μg/mL. This developed and proposed method was then validated in terms of accuracy, precision, linearity and robustness which can be successfully used for the quantization of zinc in insulin.

  2. 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)

  3. Absorption imaging of a single atom

    OpenAIRE

    Streed, E. W.; Jechow, A.; Norton, B. G.; Kielpinski, D.

    2012-01-01

    Absorption imaging has played a key role in the advancement of science from van Leeuwenhoek's discovery of red blood cells to modern observations of dust clouds in stellar nebulas and Bose-Einstein condensates. Here we show the first absorption imaging of a single atom isolated in vacuum. The optical properties of atoms are thoroughly understood, so a single atom is an ideal system for testing the limits of absorption imaging. A single atomic ion was confined in an RF Paul trap and the absorp...

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

    Science.gov (United States)

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

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. PMID:27260436

  5. Ultrasound-assisted extraction technique for establishing selenium contents in breast cancer biopsies by Zeeman-electrothermal atomic absorption spectrometry using multi-injection

    International Nuclear Information System (INIS)

    A solid-liquid extraction method is developed to establish the contents of selenium in breast cancer biopsies. The method is based on the ultrasound-assisted extraction of selenium from pretreated biopsies prior to Se determination by atomic absorption spectrometry with longitudinal-Zeeman background correction. Fifty-one breast biopsies were collected from the Cies Hospital (Vigo, Spain), 32 of which correspond to tumor tissue and 19 to normal tissue (parenchyma). Difficulties arising from the samples analyzed, i.e. small samples mass (50-100 mg), extremely low Se contents and sample texture modification including tissue hardening due to formaldehyde preservation are addressed and overcome. High intensity sonication using a probe together with addition of hydrogen peroxide succeeded in completely extracting Se from biopsies. The multiple injection technique was useful to tackle the low Se contents present in some biopsies. The detection limit was 25 ng g-1 of Se and the precision, expressed as relative standard deviation, was less than 10%. Se contents ranged from 0.08 to 0.4 μg g-1 for parenchyma samples and from 0.09 to 0.8 μg g-1 for tumor samples. In general, Se levels in tumor biopsies were higher as compared with the adjacent normal tissue in 19 patients by a factor of up to 6. Analytical data confirmed Se accumulation in the breast tumors

  6. 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

  7. Suspended nanoparticles in surfactant media as a microextraction technique for simultaneous separation and preconcentration of cobalt, nickel and copper ions for electrothermal atomic absorption spectrometry determination.

    Science.gov (United States)

    Dadfarnia, Shayessteh; Shakerian, Farid; Shabani, Ali Mohammad Haji

    2013-03-15

    The aim of this study was to describe a new method of microextraction based on the suspension of alumina nanoparticles in the surfactant media for simultaneous separation and preconcentration of the ultra-traces of cobalt, nickel and copper ions. In this technique, the alumina nanoparticles were suspended in the non-ionic surfactant solution of Triton X-114. The analytes in the sample solution were adsorbed onto the nanoparticles. After the phase separation based on the cloud point of the mixture at 40 °C, the nanoparticles settled down in the surfactant rich phase. Then 120 μL of nitric acid (3.0 mol L(-1)) was added to the surfactant rich phase which caused desorption of the analytes. Finally, the liquid phase was separated by centrifugation from the nanoparticles and was used for the quantification of the analytes by the electrothermal atomic absorption spectrometry (ETAAS). The parameters affecting the extraction and detection processes were optimized. Under the optimized experimental conditions (i.e. pH∼8, Triton X-114, 0.05% (v/v); temperature 40 °C), a sample volume of 25 mL resulted in the enhancement factors of 198, 205 and 206 and detection limits (defined as 3Sb/m) of 2.5, 2.8 and 2.6 ng L(-1) for Co(II), Ni(II) and Cu(II) respectively. The sorbent showed high capacity for these metal ions (30-40 mg g(-1) sorbent). The method was successfully applied to the determination of the analytes in natural water samples. PMID:23598108

  8. 原子吸收光谱分析中的绿色萃取富集技术%Green extraction and preconcentration techniques in atomic absorption spectrometry.

    Institute of Scientific and Technical Information of China (English)

    邓勃

    2011-01-01

    Sample pretreatment is an essential condition to obtain exact results in the analysis of complicated samples and trace components. Extraction has been extensively applied to the separation and preconcentra-tion of trace inorganic metallic ions. In recent years, analysts have developed several enviroment-friendly green extraction techniques, including single-drop microextraction, cloud point extraction, dispersive liquid-liquid microextraction, room-temperature ionic liquid extraction, solid-liquid extraction, solid phase microextraction and molecularly imprinted polymer extraction. Their common advantages over conventional liquid-liquid extraction are: (1) using only small quantities of organic solvents; (2) high extraction efficiency and large enrichment factor; (3) less consumption of samples and reagents; (4) fast and simple-to-operate; (5) easy to combine with instrumental analysis methods; and (6) wide application fields. In this paper, the advances of applications of these green extraction techniques in atomic absorption spectrometry during last three years are reviewed with 85 references.%分析复杂样品和测定痕量组分时,样品预处理是获得准确结果的必要条件.萃取是广泛使用的分离富集方法,近年来,分析工作者陆续开发了多种新型绿色微萃取技术,包括单滴微萃取、浊点萃取、分散液-液微萃取、室温离子液体萃取、固-液萃取、固相微萃取、分子印迹聚合物萃取等.他们共同的优点是:有机萃取溶剂用量非常小;萃取效率高,富集倍数大;样品和试剂消耗少;操作简便、快速;便于与其他分析仪器联用;应用范围广等.本文介绍这些新型绿色萃取技术近3年来的进展,引用文献85篇.

  9. 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

  10. Advanced atomic force microscopy techniques

    OpenAIRE

    Thilo Glatzel; Hendrik Hölscher; Thomas Schimmel; Baykara, Mehmet Z; Schwarz, Udo D.; Ricardo Garcia

    2012-01-01

    Although its conceptual approach is as simple as the technique used in record players already introduced in the 19th century, the invention of the atomic force microscope (AFM) in 1986 by Binnig, Quate, and Gerber was a milestone for nanotechnology. The scanning tunneling microscope (STM), introduced some years earlier, had already achieved atomic resolution, but is limited to conductive surfaces. Since its operational principle is based on the detection of the forces acting between tip and s...

  11. Atomic absorption spectroscopy with high temperature flames.

    Science.gov (United States)

    Willis, J B

    1968-07-01

    An account is given of the history of the development of high temperature flames for the atomic absorption measurement of metals forming refractory oxides. The principles governing the design of premix burners for such flames, and the relative merits of different types of nebulizer burner systems are described. After a brief account of the structure and emission characteristics of the premixed oxygen-acetylene and nitrous oxide-acetylene flames, the scope and limitations of the latter flame in chemical analysis are discussed. PMID:20068790

  12. A laboratory manual for the determination of metals in water and wastewater by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    This guide presents, in addition to a brief discussion of the basic principles and practical aspects of atomic absorption spectrophotometry, a scheme of analysis for the determination of 19 metals in water and wastewater, 16 by flame atomic absorption and 3 by vapour generation techniques. Simplicity, speed and accuracy were the main criteria considered in the selection of the various methods

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

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1996-01-01

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

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

    Data.gov (United States)

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

  15. Integração de técnicas analíticas e proposta de experimentos para cursos de graduação em análise instrumental: uso de espectrômetro de absorção atômica para medidas de absorção molecular Integration of analytical techniques and undergraduate laboratory in instrumental analysis: use of an atomic absorption spectrometer for molecular absorption measurements

    Directory of Open Access Journals (Sweden)

    Marcos S. Gomes

    2006-07-01

    Full Text Available Simple experiments are proposed for measuring molecular absorption of chromate and dichromate ions using an atomic absorption spectrometer. The experiments can help undergraduate students in instrumental analysis courses understand important aspects involving conceptual and instrumental similarities and differences between frequently used analytical techniques. Hollow cathode lamps were selected with wavelengths in the region of molecular absorption of chromate and dichromate. Calibration curves were obtained and the linear dynamic range was evaluated. Results were compared with those obtained in a molecular absorption spectrometer. The molar absorptivities obtained were also compared.

  16. Atomic absorption determination of yttrium in matallurgic materials

    International Nuclear Information System (INIS)

    Atomic absorption spectroscopy techniques have been developed for Y determination in Mg-, Cr-, Ni-, Ti base alloys. The lower limit of Y determination is 0.01%. The Sr amount equals 0.07 and 0.035 for the 0.01-0.1 and 0.1-1.0 mas.% ranges of Y concentration, respectively. The presence in solution of 0.5-5 M HCl, H2SO4 and HNO3 as well as of up to 1 mg/ml Fe, Co, Zr, Ce, Sn, Zn, Cu, Mo doesn't affect the analysis results

  17. Determination of metallic impurities in uranium compounds of nuclear purity by atomic absorption spectrophotometry with electrothermal atomization

    International Nuclear Information System (INIS)

    Atomic absorption spectrometry, with electrothermal atomization, has been used for the determination of Al, Cd, Cr, Fe, Mn and Ni in uranium oxide standards. The analysis were performed without sample dissolution and without uranium chemical separation. This technique is adequate for the qualification of uranium of nuclear purity according to the standard specifications. (Author)

  18. Gold analysis by the gamma absorption technique.

    Science.gov (United States)

    Kurtoglu, Arzu; Tugrul, A Beril

    2003-01-01

    Gold (Au) analyses are generally performed using destructive techniques. In this study, the Gamma Absorption Technique has been employed for gold analysis. A series of different gold alloys of known gold content were analysed and a calibration curve was obtained. This curve was then used for the analysis of unknown samples. Gold analyses can be made non-destructively, easily and quickly by the gamma absorption technique. The mass attenuation coefficients of the alloys were measured around the K-shell absorption edge of Au. Theoretical mass attenuation coefficient values were obtained using the WinXCom program and comparison of the experimental results with the theoretical values showed generally good and acceptable agreement. PMID:12485656

  19. Flotation and atomic absorption spectrophotometric investigation of molybdenum

    International Nuclear Information System (INIS)

    The removal of molybdenum from an aqueous solution by the combined use of sodium diethyldithiocarbamate (Na DDTC) and oleic acid γHOL) was studied by flotation technique. The effect of variables such as Na DDTC, HOL concentrations and pH on the floatability were examined. About 98% of the molybdenum could be floated under the optimum conditions. In the investigation of molybdenum by atomic absorption spectrophotometry, Na DDTC was used to eliminate the interference effects of cations by its adding to both the sample and the standard solutions of cations. Also, the mechanism of this elimination was discussed. The interfering effects of some cations in different acid media and the phenomenal interference in presence of heteropoly atoms were explained. Moreover, the effect of multicomponent mixtures of cations was elaborated. 20 refs

  20. 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

  1. Speciesion arsenic and selenium using hydride method atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Hydrides production - atomic absorption spectroscopy system was studied. Hydrides production tool and gas-liquid separator were tested and successfully used in this work. Hydride was produced through natrium borohydride reaction with sample solution. Emitted gas was separated by gas-liquid separator before it is carried by nitrogen gas through T tube which is put in atomic absorption flame spectrophotometer. Efficiency of the system was tested through standard reference sample and seawater / sediment samples which is collected from Negeri Johor water bays

  2. Determination of trace amounts of scandium by atomic absorption spectroscopy.

    Science.gov (United States)

    Chau, Y K

    1968-05-01

    Optimum instrumental conditions were investigated for the determination of trace quantities of scandium by atomic-absorption spectroscopy. Enhancement effects by organic solvents and by complex extractions were also studied. (46)Sc was used to establish the optimum extraction conditions. A sensitivity of 0.06 ppm of Sc was observed when using extraction into oxine-butanol and atomic absorption was measured with an acetylene-nitrous oxide flame. PMID:18960315

  3. Transient x-ray absorption spectroscopy of hydrated halogen atom

    CERN Document Server

    Elles, Christopher G; Crowell, Robert A; Arms, Dohn A; Landahl, Eric C

    2007-01-01

    Time-resolved x-ray absorption spectroscopy monitors the transient species generated by one-photon detachment of an electron from aqueous bromide. Hydrated bromine atoms with a lifetime of ca. 17 ns were observed, nearly half of which react with excess Br- to form Br2-. The K-edge spectra of the Br atom and Br2- anion exhibit distinctive resonant transitions that are absent for the Br- precursor. The absorption spectra indicate that the solvent shell around a Br0 atom is defined primarily by hydrophobic interactions, in agreement with a Monte Carlo simulation of the solvent structure.

  4. Perfect electromagnetic absorption at one-atom-thick scale

    Energy Technology Data Exchange (ETDEWEB)

    Li, Sucheng; Duan, Qian; Li, Shuo; Yin, Qiang; Lu, Weixin; Li, Liang; Hou, Bo, E-mail: houbo@suda.edu.cn [College of Physics, Optoelectronics and Energy and Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006 (China); Gu, Bangming [Institute of Applied Physics, Zhejiang Wanli University, 8 Qianhu South Road, Ningbo 315101 (China); Wen, Weijia [Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2015-11-02

    We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration.

  5. Perfect electromagnetic absorption at one-atom-thick scale

    International Nuclear Information System (INIS)

    We experimentally demonstrate that perfect electromagnetic absorption can be realized in the one-atom thick graphene. Employing coherent illumination in the waveguide system, the absorbance of the unpatterned graphene monolayer is observed to be greater than 94% over the microwave X-band, 7–13 GHz, and to achieve a full absorption, >99% in experiment, at ∼8.3 GHz. In addition, the absorption characteristic manifests equivalently a wide range of incident angle. The experimental results agree very well with the theoretical calculations. Our work accomplishes the broadband, wide-angle, high-performance absorption in the thinnest material with simple configuration

  6. Direct atomic absorption determination of cadmium in solid foodstuffs

    International Nuclear Information System (INIS)

    A procedure is proposed for the direct rapid determination of cadmium in solid foodstuff samples by atomic absorption analysis using a modified Lvov furnace equipped with a graphite partition filter. The use of this furnace eliminates the step of transferring a solid sample to solution, allows calibration solutions to be employed properly in the direct analysis of solid samples, suppresses unselective absorption, and substantially shortens the time of analysis. 12 refs., 3 figs., 2 tabs

  7. 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

  8. Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

    International Nuclear Information System (INIS)

    Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C0, where the change in characteristic mass, m0, can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as Emax, maximum enhancement factor; Et, enhancement for 1.0 minute sampling and Ev, enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps

  9. Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

    Energy Technology Data Exchange (ETDEWEB)

    Ataman, O. Yavuz [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey)], E-mail: ataman@metu.edu.tr

    2008-08-15

    Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C{sub 0}, where the change in characteristic mass, m{sub 0}, can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as E{sub max}, maximum enhancement factor; E{sub t}, enhancement for 1.0 minute sampling and E{sub v}, enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps.

  10. Vapor generation and atom traps: Atomic absorption spectrometry at the ng/L level

    Science.gov (United States)

    Ataman, O. Yavuz

    2008-08-01

    Atom-trapping atomic absorption spectrometry is a technique that allows detection at the ng/L level for several analytes such as As, Se, Sb, Pb, Bi, Cd, In, Tl, Te, Sn and Hg. The principle involves generation of volatile species, usually hydrides, trapping these species on the surface of an atom trap held at an optimized temperature and, finally, revolatilizing the analyte species by rapid heating of the trap and transporting them in a carrier gas to a heated quartz tube, as commonly used with hydride generation AAS systems. A transient signal having, in most cases, a full width at half maximum of less than 1 s is obtained. The atom trap may be a quartz surface or a W-coil; the former is heated externally and the latter is heated resistively. Both collection and revolatilization temperatures are optimized. In some cases, the W-coil itself is used as an electrothermal atomizer and a heated quartz tube is then not needed. The evolution of these traps starts with the well-known Watling's slotted quartz tube (SQT), continues with atom trapping SQT and finally reaches the present traps mentioned above. The analytical figures of merit for these traps need to be standardized. Naturally, enhancement is on characteristic concentration, C0, where the change in characteristic mass, m0, can be related to trapping efficiency. Novel terms are suggested for E, enhancement factor; such as Emax, maximum enhancement factor; Et, enhancement for 1.0 minute sampling and Ev, enhancement for 1.0 mL of sample. These figures will allow easy comparison of results from different laboratories as well as different analytes and/or traps.

  11. Absorption spectrum of Ca atoms attached to 4He nanodroplets

    OpenAIRE

    Hernando, Alberto; Barranco Gómez, Manuel; Mayol Sánchez, Ricardo; Pi Pericay, Martí; Krosnicki, Marek

    2008-01-01

    Within density functional theory, we have obtained the structure of $^4$He droplets doped with neutral calcium atoms. These results have been used, in conjunction with newly determined {\\it ab-initio} $^1\\Sigma$ and $^1\\Pi$ Ca-He pair potentials, to address the $4s4p$ $^1$P$_1 \\leftarrow 4s^2$ $^1$S$_0$ transition of the attached Ca atom, finding a fairly good agreement with absorption experimental data. We have studied the drop structure as a function of the position of the Ca atom with resp...

  12. Electromagnetically induced absorption in metastable 83Kr atoms

    CERN Document Server

    Kale, Y B; Mishra, S R; Singh, S; Rawat, H S

    2015-01-01

    We report electromagnetically induced absorption (EIA) resonances of sub-natural linewidth (FWHM) in metastable noble gas 83Kr* atoms using degenerate two level schemes (DTLSs). This is the first observation of EIA effect in a metastable noble gas atoms. Using these spectrally narrow EIA signals obtained corresponding to the closed hyperfine transition from 4p55s[3/2]2 to 4p55p[5/2]3 hyperfine manifolds of 83Kr* atoms, we have measured the Lande's g-factor (gF) for the lower level (F = 13/2) of the closed transition accurately with small applied magnetic fields of few Gauss.

  13. Developing a Transdisciplinary Teaching Implement for Atomic Absorption Spectroscopy

    Science.gov (United States)

    Drew, John

    2008-01-01

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

  14. 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...

  15. The determination of zirconium by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

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

  16. Advances with tungsten coil atomizers: Continuum source atomic absorption and emission spectrometry

    International Nuclear Information System (INIS)

    Two new tungsten coil spectrometers are described: a continuum source tungsten coil atomic absorption spectrometer and a tungsten coil atomic emission spectrometer. Both devices use a 150 W tungsten coil extracted from a slide projector bulb. The power is provided by a computer-controlled, solid state, constant current 0-10 A supply. The heart of the optical system is a high-resolution spectrometer with a multi-channel detector. The continuum source system employs xenon or deuterium lamps, and is capable of multi-element analyses of complex samples like engine oil, urine, and polluted water. Spiked engine oil samples give mean percent recoveries of 98 ± 9, 104 ± 9, and 93 ± 0.8 for Al, V, and Ni, respectively. Copper, Zn, and Cd are determined in urine samples; while Cd, Co, Yb, and Sr are determined in water samples. Detection limits for Cd, Zn, Cu, Yb, Sr, and Co are: 8, 40, 1, 4, 1, and 4 μg l-1. The technique of tungsten coil atomic emission spectrometry using a 150 W commercial projector bulb is reported for the first time. Calcium, Ba, and Sr are determined with detection limits of 0.01, 0.5, and 0.1 μg l-1. Relative standard deviations are lower than 10% in each case, and Sr is determined in two water standard reference materials

  17. 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.

  18. Determination of cadmium in aluminium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

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

  19. Absorption spectrum of very low pressure atomic hydrogen

    CERN Document Server

    Moret-Bailly, Jacques

    2015-01-01

    Spectra of quasars result primarily from interactions of natural light with atomic hydrogen. A visible absorption of a sharp and saturated spectral line in a gas requires a low pressure, so a long path without blushing as a cosmological redshift. Burbidge and Karlsson observed that redshifts of quasars result from fundamental redshifts, written 3K and 4K, that cause a shift of absorbed beta and gamma lines of H to alpha gas line. Thus absorbed spectrum is shifted until an absorbed line overlaps with Lyman alpha line of gas: redshift only occurs if an alpha absorption pumps atoms to 2P state. Thus, space is divided into spherical shells centered on the quasar, containing or not 2P atoms. Neglecting collisional de-excitations in absorbing shells, more and more atoms are excited until amplification of a beam having a long path in a shell, thus perpendicular to the observed ray, is large enough for a superradiant flash at alpha frequency. Energy is provided by atoms and observed ray, absorbing a line at local Lym...

  20. Novel absorption detection techniques for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Y.

    1994-07-27

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

  1. Study on the application of cold vapor atomic absorption spectrometry and hydride generation atomic absorption spectrometry for the determination of Hg and As traces in sea water samples

    International Nuclear Information System (INIS)

    The trace amount of total mercury (Hg) and arsenic (As) in sea water samples were quantitatively determined by using the Atomic Absorption Spectrometry connected with the hydride generation technique (HG-AAS) for As, and with the cold vapour technique (CV-AAS) for Hg. The experiments were carried out at room temperature on a Hydride System Module (HS55) combined with an Atomic Absorption Spectrometer (VARIO 6, Analytik Jena AG). The effect of reductants concentration, and that of matrix on the absorption intensity of each analyzed element was studied in details. The sea water sample after fitrating through a membrane with 0.45(μm-hole size was pre-treated with an oxidant or an reductant to obtain the identical medium. The absorption intensity of each element was then measured on the VARIO-6 under the optimum parameters for spectrometer such as: maximum wavelength, current of hollow cathode lamp, and that for hydride system such as cell temperature, speed of peristaltic pump, pump time, reaction time and rewash time, ect. The analytical procedures were set-up and applied for the determination of these above mentioned elements in the synthesized sea water sample and in the real sea water samples with high precision and accuracy. (author)

  2. 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

  3. Rare earth aerosol analysis by atomic absorption spectrophotometry using electrothermal atomization

    International Nuclear Information System (INIS)

    Atomic absorption spectrophotometry (AAS) employing electrothermal atomization in a pyrolytic graphite tube is shown to be a precise and accurate method for analysis of 11 rare earth, or rare-earth-like elements in air filter samples taken in a thorium and rare earth refinery. The method is fairly rapid since it involves only fluoric acids. Each element was sequentially analyzed from the same resulting solution by using either the techniques of standard-curve calibration or that of standard additions. The two methods used on the same sample gave essentially identical results (composite ratio for 171 such trials being 0.9996). Matrix effects were negligible and no background correction was necessary. The average percent standard deviation for all duplicate trials (176) was 4.2%. Elements analyzed by this method were La, Nd, Sm, Eu, Gd, Dy, Ho, Tm, Yb, Gd, Sc and Y. Other rare earths such as erbium (Er), lutetium (Lu), and terbium (Tb), with comparable analytical sensitivity by AAS to Dy, Sm, and Nd, respectively, could presumably be analyzed by this method as well

  4. Evaluation of electrochemical generation of volatile zinc hydride by heated quartz tube atomizer atomic absorption spectrometry.

    Science.gov (United States)

    Arbab-Zavar, Mohammad-Hossein; Chamsaz, Mahmoud; Youssefi, Abbas; Aliakbari, Mostafa

    2012-01-01

    Electrochemical hydride generation (EcHG) as a sample introduction system for determination of zinc was developed. It was directly coupled to an electrically heated quartz tube atomizer (QTA) atomic absorption spectrometry (AAS) system. The hydride generator is a laboratory-made semi-batch electrolytic cell that consists of a lead-tin alloy cathode and a platinum anode. The effects of typical parameters on the generation efficiency of the technique, such as types of cathode material and catholyte and anolyte solutions, were studied. The influences of numerical experimental operating parameters on the analytical signal were evaluated in detail and optimum conditions were obtained. The analytical figures of merit for the developed method were determined. The calibration curve was linear up to 300 ng mL(-1) of Zn. A concentration detection limit (3σ, n = 9) of 11 ng mL(-1) Zn and a relative standard deviation of 5.0% (RSD, n = 9) for 200 ng mL(-1) Zn were accessed. In addition, the susceptibility of interference from various ions was evaluated. The accuracy of the method was verified by determination of Zn in a certified reference material and in tap water. The achieved concentrations were found to be in good agreement with both the certified value and the data obtained using flame AAS. PMID:22790376

  5. Rare earth analysis in human biological samples by atomic absorption using electrothermal atomization

    International Nuclear Information System (INIS)

    The determination of Sc and seven rare earth elements, Nd, Sm, Dy, Ho, Eu, Tm, and Yb, in biological samplesby atomic absorption spectrophotometric analysis (AAS) using electrothermal atomization in a pyrolytic graphite tube is shown to be rapid, precise and accurate. The technique utilizes the method of standard additions and linear regression analysis to determine results from peak area data. Inter-elemental interferences are negligible. The elements found sensitive enough for this type of analysis are, in order of decreasing sensitivity, Yb, Eu, Tm, Dy, Sc, Ho, Sm and Nd. The determination in these types of materials of Gd and elements less sensitive to AAS detection than Gd does not appear to be feasible. Results are presented on the concentrations of these elements in 41 samples from human subjects, cows and vegetables with normal environmental exposure to the rare earth elements. The composite percent mean deviation in peak-area readings for all samples and all elements examined was 4%. The mean standard error in the results among samples was about 6.5%

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

    Science.gov (United States)

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

    1981-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    103-104, JAN-FEB (2015), s. 155-163. ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : gold * volatile species generation * quartz atomizers * atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.176, year: 2014

  8. Atomization in graphite-furnace atomic absorption spectrometry. Peak-height method vs. integration method of measuring absorbance: heated graphite atomizer 2100

    International Nuclear Information System (INIS)

    The signal integration technique developed and reported earlier has been used for measuring atomic absorption signals generated by the Heated Graphite Atomizer 2100. Cd, Zn, Al, Sn, Cu, Mo, and V have been selected for this study. In theory, the integration method of measuring absorbance is superior to the conventional peak-height as the measure of absorbance. In practice, integration does offer some advantages over the peak-height method of measurement; absolute sensitivity is increased by a factor of 2- to 8-fold and the linear range of the working curves is increased by a factor of up to 2. This study shows the effect of the better cell geometry of the HGA 2100 (as opposed to the Carbon Rod Atomizer 63) on the integrated absorbance signals. Modifications to the Heated Graphite Atomizer 2100 which would improve the atomization conditions beneficial to the integration method of measuring are suggested. (U.S.)

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

    Science.gov (United States)

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

    2005-05-01

    Two sensitive spectrophotometric and atomic absorption spectrometric procedures have been developed for determination of cinchocaine hydrochloride (Cin.Cl) in pure form and in pharmaceutical formulation. The spectrophotometric method was based on formation of an insoluble colored ion-associate between the cited drug and tetrathiocyanatocobaltate (CoTC) or hexathiocyanatochromate (CrTC) which dissolved and extracted in an organic solvent. The optimal experimental conditions for quantitative extraction such as pH, concentration of the reagents and solvent were studied. Toluene and iso-butyl alcohol proved to be the most suitable solvents for quantitative extraction of Cin-CoTC and Cin-CrTC ion-associates with maximum absorbance at 620 and 555 nm, respectively. The optimum concentration ranges, molar absorptivities, Ringbom ranges and Sandell sensitivities were also evaluated. The atomic absorption spectrometric method is based on measuring of the excess cobalt or chromium in the aqueous solution, after precipitation of the drug, at 240.7 and 357.9 nm, respectively. Linear application ranges, characteristic masses and detection limits were 57.99-361.9, 50.40 and 4.22 microg ml(-1) of Cin.Cl, in case of CoTC, while 37.99-379.9, 18.94 and 0.81 microg ml(-1) in case of CrTC. PMID:15910814

  10. 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.)

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

    Science.gov (United States)

    Gorczyca, T. W.; Bautista, M. A.; Hasoglu, M. F.; Garcia, J.; Gatuzz, E.; Kaastra, J. S.; Kallman, T. R.; Manson, S. T.; Mendoza, C.; Raassen, A. J. J.; de Vries, C. P.; Zatsarinny, O.

    2013-01-01

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

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

    Roč. 111, SEP (2015), s. 57-63. ISSN 0584-8547 Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : dielectric barrier discharge * hydride generation-atomic absorption spectrometry * selenium Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.176, year: 2014

  13. Speciation and determination of inorganic selenium species by a simple and rapid technique using selective separation on mercury coated electrode coupled with electrothermal atomic absorption spectroscopy (ED-ETAAS) in water samples

    International Nuclear Information System (INIS)

    Complete text of publication follows. Speciation analyses are of increasing interest in environmental toxicological and analytical fields, as the toxicity and reactivity of trace elements depend strongly on the chemical forms in which they are involved. A simple electrodeposition-electrothermal atomic absorption spectroscopy (ED-ETAAS) method for speciation analysis of inorganic selenium species in some water samples has been developed. The method is based on the selective reduction of the Se(IV) at uncontrolled applied potential (1.5-2.0 V) on a mercury coated electrode. In acidic media (1.0M HCl solution) only Se(IV) was electrodeposited in mercury electrode surface after removal of the electrode, the separated Se(VI) was remained in solution. The spent electrolyte containing Se(VI) was measured by ETAAS under optimum conditions. Se(IV) was calculated as the difference between the measured total selenium and Se(VI) content. The spiked average recovery value varied between 98 to 103%. An experimental design was developed to investigate the effective parameters on selenium ETAAS measurement. Response surface methodology (RSM) and central composite face centered design (CCF) have been used as a strategy for evaluation of the effects of these parameters. Based on the analysis results, the optimal conditions were predicted as follows: modifier concentration 40(ppm), ashing temperature 500(deg C), atomization temperature 2400(deg C), drying time 20(s), ashing time 15(s) and atomization times 4(s). Under these conditions statistical assessment showed a good agreement between predicted and observed values. The performance of suggested method has been shown by characteristic mass mo=70 pg for Se (IV) and LOD = 0.9 μg L-1 for Se (VI) with RSD of 3.5% for measurement of 100 μg L-1 of Se (IV).

  14. Alternative approaches to correct interferences in the determination of boron in shrimps by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The aim of this study is to propose alternative techniques and methods in combination with the classical chemical modification to correct the major matrix interferences in the determination of boron in shrimps. The performance of an internal standard (Ge) for the determination of boron by the simultaneous multi-element atomic absorption spectrometry was tested. The use of internal standardization increased the recovery from 85.9% to 101% and allowed a simple correction of errors during sampling preparation and heating process. Furthermore, a new preparation procedure based on the use of citric acid during digestion and dilution steps improved the sensitivity of the method and decreased the limit of detection. Finally, a comparative study between the simultaneous multi-element atomic absorption spectrometry with a longitudinal Zeeman-effect background correction system, equipped with a transversely-heated graphite atomizer and the single element atomic absorption spectrometry with a D2 background correction system, equipped with an end-heated graphite atomizer was undertaken to investigate the different behavior of boron in both techniques. Different chemical modifiers for the determination of boron were tested with both techniques. Ni-citric acid and Ca were the optimal chemical modifiers when simultaneous multi-element atomic absorption spectrometry and single-element atomic absorption spectrometry were used, respectively. By using the single-element atomic absorption spectrometry, the calculated characteristic mass was 220 pg and the calculated limit of detection was 370 μg/kg. On the contrary, with simultaneous multi-element atomic absorption spectrometry, the characteristic mass was 2200 pg and the limit of detection was 5.5 mg/kg. - Highlights: • New approaches were developed to cope with interferences of B determination by ETAAS • Ge was used as internal standard for the determination of B by simultaneous ETAAS • Citric acid was used during digestion

  15. Two-photon dichroic atomic vapor laser lock using electromagnetically induced transparency and absorption

    International Nuclear Information System (INIS)

    We demonstrate a technique to lock the frequency of a laser to a transition between two excited states in Rb vapor using a two-photon process in the presence of a weak magnetic field. We use a ladder configuration from specific hyperfine sublevels of the 5S1/2, 5P3/2, and 5D5/2 levels. This atomic configuration can show electromagnetically induced transparency and absorption processes. The error signal comes from the difference in the transparency or absorption felt by the two orthogonal polarizations of the probe beam. A simplified model is in good quantitative agreement with the observed signals for the experimental parameters. We have used this technique to lock the frequency of the laser up to 1.5 GHz off atomic resonance.

  16. Microwave Digestion of Hair Samples in Closed Vessels for the Determinations of Copper and Iron by Derivative Flame Atomic Absorption Spectrometry using Flow-injection Technique%微波溶样-流动注射-导数火焰原子吸收光谱测定人发中的铜和铁

    Institute of Scientific and Technical Information of China (English)

    陈兰菊; 郑连义; 孙汉文

    2002-01-01

      本文以微波消解人发样,利用流动注射-导数火焰原子吸收法测定其中微量铜、铁的含量。微波溶样技术具有快捷、污染小、损失少、消化完全等优点;流动注射进样技术可以克服常规火焰原子吸收法耗样量大和基体干扰严重的缺点;导数技术应用于火焰原子吸收可提高方法的灵敏度和信号的选择性。微波溶样、流动注射与导数技术相结合应用于火焰原子吸收成功地测定了人发中的微量铜和铁。%  A new method was presented for the determinations of copper and iron in hair samples,which was based on the technique of microwave digestion in closed vessels,flow-injection and derivative flame atomic absorption spectrometry. The technique of microwave digestion is convenient, little of pollution, less in loss, and complete digestion. The flaws that sampling is large and matrix interference is serious in conventional flame atomic absorption spectrometry(FAAS) were overcome by flow-injection sampling technique. The sensitivity and signal selectivity were enhanced when derivative technique was used. This new method that derivative flame atomic absorption spectrometry combined with microwave digestion and flow-injection technique is simple and rapid with satisfactory results for determination of copper and iron in hair.

  17. Flame atomic absorption determination of ultra trace zinc after preconcentration

    International Nuclear Information System (INIS)

    Complete text of publication follows. The determination of toxic metal ions is becoming increasingly important because of the increased interest in environmental samples including water, soil, plant, etc. Although flame atomic absorption spectrometry is widely used because of its low cost, its sensitivity is usually insufficient for the low concentrations found in environmental samples. Matrix interferences are another problem in atomic absorption spectrometric determinations of trace elements. Solving these problems requires a preconcentration and a matrix elimination step (A. Uzun et al., Talanta, 54, (2001)197). Zinc is a biologically essential micronutrient, and coordinates with macromolecules as a cofactor to confer catalytic function of structural integrity. Such metalloproteins have been implicated in diverse functions ranging from protein, nucleic acid, carbohydrate, and lipid metabolism, to gene transcription (B.L. Vallee et al., Physio. Revs, 73:1 (1993) 99). Zinc is frequently present at trace level in cadmium and their compounds. Numerous methods have been published for such determination. However, they are not simple and usually require extensive and laborious steps for separation of zinc from cadmium (C.W. McDonald et al., Anal. Chem., 46 (1974) 300). In this work a simple, reliable and rapid method for determination of ultra trace zinc by flame atomic absorption spectrometry is presented. The limit of detection (LOD), of the proposed method for the determination of Zn2+ ion was studied under the optimal experimental conditions. The LOD obtained from CLOD=KbSbm-1 (J.D. Ingle et al., Spectrochemical Analysis, Prentice Hall, Englewood Cliffs, NJ, 1988) for a numerical factor Kb=3 is 120 ng.L-1.The method was successfully applied for the determination of zinc ion in different samples, especially determination of ultra trace amount of zinc in waters and plants.

  18. Differential absorption radar techniques: surface pressure

    Directory of Open Access Journals (Sweden)

    L. Millán

    2014-11-01

    Full Text Available Two radar pulses sent at different frequencies near the 60 GHz O2 absorption band can be used to determine surface pressure by measuring the differential absorption on and off the band. Results of inverting synthetic data assuming an airborne radar are presented. The analysis includes the effects of temperature, water vapor, and hydrometeors, as well as particle size distributions and surface backscatter uncertainties. Results show that an airborne radar (with sensitivity of −20 and 0.05 dBZ speckle and relative calibration uncertainties can estimate surface pressure with a precision of ~ 1.0 hPa and accuracy better than 1.0 hPa for clear-sky and cloudy conditions and better than 3.5 hPa for precipitating conditions. Generally, accuracy would be around 0.5 and 2 hPa for non-precipitating and precipitating conditions, respectively.

  19. 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)

  20. 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)

  1. A heated chamber burner for atomic absorption spectroscopy.

    Science.gov (United States)

    Venghiattis, A A

    1968-07-01

    A new heated chamber burner is described. The burner is of the premixed type, and burner heads of the types conventionally used in atomic absorption may be readily adapted to it. This new sampling system has been tested for Ag, Al, Ca, Cu, Fe, Mg, Mn, Ni, Pb, Si, Ti, and Zn in aqueous solutions. An improvement of the order of ten times has been obtained in sensitivity, and in detection limits as well, for the elements determined. Interferences controllable are somewhat more severe than in conventional burners but are controllable. PMID:20068792

  2. Extraction-atomic-absorption determination of vanadium in salt liquors

    International Nuclear Information System (INIS)

    An extraction-atomic-absorption method to determine 0.1-0.8 mg/l vanadium in salt liquors containing 300 g/l NaCl is developed. To separate the basis extraction concentrating with hydroxyquinoline solution in chloroform with subsequent reextraction of vanadium at pH 9.4 is used. Results of vanadium determination in the salt liquer are as follows: vanadium determined x=0.22 mg/l, n=10, ssub(x)=0.045 mg/l, confidence range (at α=0.95)-(0.22+-0.03) mg/l, relative standard deviation is 0.20

  3. 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

  4. Graphite Furnace Atomic Absorption Elemental Analysis of Ecstasy Tablets

    OpenAIRE

    French, Holly E.; Michael J. Went; Gibson, Stuart J

    2013-01-01

    Abstract: Six metals (Cu, Mg, Ba, Ni, Cr, Pb) were determined in two separate batches of seized ecstasy tablets by graphite furnace atomic absorption spectroscopy (GFAAS) following digestion with nitric acid and hydrogen peroxide. Large intra-batch variations were found as expected for tablets produced in clandestine laboratories. For example, nickel in batch 1 was present in the range 0.47-13.1 ppm and in batch 2 in the range 0.35-9.06 ppm. Although batch 1 had significantly high...

  5. Determination of metals in atmospheric particulates using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Nineteen trace metals in atmospheric samples have been determined by atomic absorption spectrometry, using a graphite furnace for most elements. Paper filters have been used to collect air samples. The sample preparation procedure involves the removal of organic matter and the conversion of the metals to soluble salts by ashing the filters in an oxygen plasma at 125 deg C for 6 h. and by subsequent dissolution in HN03HCl solution. The sensitivities achieved are in the range of 2,5.10-5 and 6,3.10-3 μg/m3, for an air volume of 2000 m3. (author)

  6. Application of atomic absorption in molecular analysis (spectrophotometry)

    International Nuclear Information System (INIS)

    The apparatus of atomic absorption has been considered by all the experts in chemical analysis as one of the most important equipments in actual utilization in such field. Among its several applications one should emphasize direct and indirect metals analyses using flame, graphite furnace, cold vapor generator,... Besides such known applications, the authors have developed at the R and D Center of CSN a patent pendent method for the utilization of such equipment for molecular analysis, in substitution of a sophisticated and specific apparatus. (Author)

  7. Absorption spectrum of very low pressure atomic hydrogen

    OpenAIRE

    Moret-Bailly, Jacques

    2015-01-01

    Spectra of quasars result primarily from interactions of natural light with atomic hydrogen. A visible absorption of a sharp and saturated spectral line in a gas requires a low pressure, so a long path without blushing as a cosmological redshift. Burbidge and Karlsson observed that redshifts of quasars result from fundamental redshifts, written 3K and 4K, that cause a shift of absorbed beta and gamma lines of H to alpha gas line. Thus absorbed spectrum is shifted until an absorbed line overla...

  8. Mercury pollution surveys in Riga by Zeeman atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Practical sessions of mercury pollution measurements in Riga (Latvia) have been performed in several districts using an RA-915+ Zeeman atomic absorption spectrometer coupled with a global positioning system (GPS). The measurements were taken from a driving car and in different days at one particular location (the Institute of Atomic Physics and Spectroscopy) for monitoring the changes in atmospheric mercury concentration. GPS was used to relate the measurement results to particular places, which made it possible to create a digitalized database of pollution for different geographic coordinates in different time spans. The measurements have shown that the background level of mercury concentration in Riga does not exceed 5 ng/m3, although there are several areas of elevated mercury pollution that need particular attention. (Authors)

  9. Determination of lead traces in water and liqueurs by derivative atom trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sun, H. [Department of Chemistry, Hebei University, Baoding, 071002 (China); Yang Lili [Department of Chemistry, Hebei University, Baoding, 071002 (China); Zhang Deqiang [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing (China); Wang Weixiao [Department of Chemistry, Hebei University, Baoding, 071002 (China); Sun Jianmin [Department of Chemistry, Hebei University, Baoding, 071002 (China)

    1997-07-01

    A new method for the direct determination of lead traces using derivative atom trapping flame atomic absorption spectrometry (DAT-FAAS) with an improved water-cooled stainless steel trapping equipment in an air-acetylene flame was investigated. The optimum conditions concerning the sensitivity were studied. For a 1 min collection, the characteristic concentration (given as derivative absorbance of 0.0044) and the detection limit (3s) were 1.4 ng/mL and 0.27 ng/mL, respectively. This is 361 and 74-fold better than those of the conventional flame atomic absorption spectrometry (FAAS) and comparable to those of graphite furnace atomic absorption spectrometry (GFAAS). The detection limit and sensitivity of DAT-FAAS for a 3 min collection time were 2 and 3 orders of magnitude higher than those of conventional FAAS. The present method was applied to the determination of lead in water and liqueur samples with a recovery range of 94-108% and a relative standard deviation of 3.5-5.6%. (orig.). With 5 figs., 5 tabs.

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

    Directory of Open Access Journals (Sweden)

    Sara M. Anis

    2011-09-01

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

  11. Determination of molybdenum in flotation concentrates by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Molybdenum was determined by atomic absorption spectrophotometry in 0.05 N ammoniacal solution after the decomposition of the concentrate with aqua regia. Negros ore from Philippines was used as a flotation feed, which contained chalcopyrites and calcium-magnesium minerals. Among the metals tested copper, iron and the alkaline earths interfered. Less than 50 ppm of copper yielded lower results for molybdenum. Higher results came out with more than 50 ppm of copper. In the presence of iron and citric acid (0.4 g/100 ml) which is a suppressor for hydroxide formation, a lower estimation resulted for molybdenum. Calcium interfered, lower results by 2 and >10% being obtained with respective 2.5 and 20 ppm of calcium. More than 20 ppm of magnesium behaved similarly. Sodium sulfate (0.5 g/100 ml) served as the suppressor for copper, iron and citric acid; 100 ppm each of copper and iron did not interfere in this way. Interferences due to calcium and magnesium (less than 60 ppm) was able to be masked by the addition of sodium silicate (200 ppm as silica). The analysis of flotation products and synthetic samples consisting of molybdenite, chalcopyrite, calcium chloride and magnesium sulfate revealed that the atomic absorption method can be applied to the analysis of the concentrates for molybdenum with an error of about 2%. (auth.)

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

    Science.gov (United States)

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

    2006-05-01

    Interference effects of various organic solvents miscible with water on arsenic determination by hydride generation atomic absorption spectrometry have been studied. Arsine was chemically generated in continuous flow hydride generation system and atomized by using a flame atomizer able to operate in two modes: miniature diffusion flame and flame-in-flame. The effects of experimental variables and atomization mode were investigated: tetrahydroborate and hydrochloric acid concentrations, argon, hydrogen and oxygen supply rates for the microflame, and the distance from the atomization region to the observation zone. The nature of the species formed in the flame due to the pyrolysis of organic solvent vapors entering the flame volume together with arsine is discussed. The observed signal depression in the presence of organic solvents has been mainly attributed to the atomization interference due to heterogeneous gas-solid reaction between the free arsenic atoms and finely dispersed carbon particles formed by carbon radicals recombination. The best tolerance to interferences was obtained by using flame-in-flame atomization (5-10 ml min - 1 of oxygen flow rate), together with higher argon and hydrogen supply rates and elevated observation heights.

  13. Electrochemical preconcentration and hydride generation methods for trace determination of selenium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The use of atomic absorption spectrometry in combination with two different preconcentration/separation techniques for the determination of trace concentrations of selenium is described. Electrochemical preconcentration onto a platinum electrode with a subsequent atomization of selenium is discussed briefly. Several parameters are considered such as the presence of depolarizers, and the temperature of the electrolyzed solutions. Special attention is payed to the efficiency of the atomization step, and a method to improve this is proposed. Applications of the technique to real samples are also reported. Secondly, the separation of the selenium as the volatile selenium hydride from the sample solution is considered. Several papers in this thesis deal with commonly occurring interferants as nickel and copper and with ways of minimizing or avoiding the interferring effects, whereas other papers relate to more theoretical aspects of the hydride generation process. New methods for the determination of selenium in technical samples with high contents of nickel and copper are also presented

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

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

    Science.gov (United States)

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

    2016-04-01

    Potassium (K) is an important element related to ash and fine-particle formation in biomass combustion processes. In situ measurements of gaseous atomic potassium, K(g), using robust optical absorption techniques can provide valuable insight into the K chemistry. However, for typical parts per billion K(g) concentrations in biomass flames and reactor gases, the product of atomic line strength and absorption path length can give rise to such high absorbance that the sample becomes opaque around the transition line center. We present a tunable diode laser atomic absorption spectroscopy (TDLAAS) methodology that enables accurate, calibration-free species quantification even under optically thick conditions, given that Beer-Lambert's law is valid. Analyte concentration and collisional line shape broadening are simultaneously determined by a least-squares fit of simulated to measured absorption profiles. Method validation measurements of K(g) concentrations in saturated potassium hydroxide vapor in the temperature range 950-1200 K showed excellent agreement with equilibrium calculations, and a dynamic range from 40 pptv cm to 40 ppmv cm. The applicability of the compact TDLAAS sensor is demonstrated by real-time detection of K(g) concentrations close to biomass pellets during atmospheric combustion in a laboratory reactor. PMID:26938713

  16. Atmospheric deposition of heavy metals around the lead and copper-zinc smelters in Baia Mare, Romania, studied by the moss biomonitoring technique, neutron activation analysis and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The mosses Pleurozium schreberi, Pseudoscleropodium purum and Rhytidiadelphus squarrosus were used as biomonitors to study the atmospheric deposition of metals around the lead and copper-zinc smelters in Baia Mare. Samples representing the last three years' growth of moss or its green part, collected on the ground at 28 sites located 2-17 km from the source area, were analyzed by instrumental neutron activation analysis using epithermal neutrons (ENAA) and by flame atomic absorption spectrometry (FAAS). A total of 31 elements were determined, including most of the heavy metals characteristic of emissions from this kind of industry. The observed data for Pb, As, Cu, and Cd are all high compared with those observed in other regions of Europe with similar industries, but the concentrations in moss approach regional background levels at a distance of about 8 km from the main source area. Factor analysis of the data distinguishes two industrial components, one characterized by Pb, Cu, As, and Sb, and another one by Zn and Cd. A strong crustal component including five major elements (Na, Mg, Al, Ti, Fe) and an additional number of trace elements (Sc, V, Cr, Cs, Ba, REE, Th) also appears to be derived mainly from industrial sources. The mean I value in the present material is 5 times lower than the corresponding level in moss in Norway, and also consistently lower than elsewhere in Europe, a fact which evidences the endemic character of the examined area due to iodine depletion. (author)

  17. Atmospheric deposition of heavy metals around the lead and copper-zinc smelters in Baia Mare, Romania, studied by the moss biomonitoring technique, neutron activation analysis and flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The mosses Pleurozium schreberi, Pseudoscleropodium purum and Rhytidiadelphus squarrosus were used as biomonitors to study the atmospheric deposition of heavy metals around the lead and copper-zinc smelters in Baia Mare. Samples representing the last three year's growth of moss or its green part, collected on the ground at 28 sites located 2-17 km from the source area, were analyzed by instrumental neutron activation analysis using epithermal neutrons and by flame atomic absorption spectrometry. A total of 31 elements were determined, including most of the heavy metals characteristic of emissions from this kind industry. The observed data for Pb, As, Cu, and Cd are all high compared with those observed in other regions of Europe with similar industries, but the concentrations in moss approach regional background levels at a distance of about 8 km from the main source area. Factor analysis of the data distinguishes two industrial components, one characterized by Pb, Cu, As, and Sb, and another one by Zn and Cd. A strong crustal component including five major elements (Na, Mg, Al, Ti, Fe) and an additional number of trace elements (Sc, V, Cr, Cs, Ba, REE, Th) also appears to be derived mainly from industrial sources. The mean I value in the present material is 5 times lower than the corresponding level in moss in Norway, and also consistently lower than elsewhere in Europe, a fact which evidence the endemic character of the examined area due to iodine depletion

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

    CERN Document Server

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

    2002-01-01

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

  19. Determination of gold by chemical hydride generation atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. The chemical vapour generation (CVG) of transition and noble metals opens a novel route for introduction of these elements into atomic spectrometric sources. It can be accomplished by merging an acidic sample with tetrahydroborate reductant solution (Y. L. Feng et al., J. of Anal. At. Spectrom., 20 (2005) 255-265). There have been some studies for determination of Au; however, only mg L-1 levels of gold have been determined by CVG - Atomic Absorption Spectrometry (AAS) (G. Ertas et al., Applied Spectroscopy, 60 (2006) 423-429). Volatile Au species were generated in flow injection arrangement from acid environment in presence of surfactants. The core of the system is a mixing manifold based on 3 concentric capillaries (T. Matousek et al., J. of Anal. At. Spectrom., 18 (2003) 487-494) protruding into the glass gas-liquid separator (glass, volume 3 ml). Optimum flow rate of Ar as a carrier gas was found at 240 mL/min. The study of generation parameters as well as the use of reaction modifiers-surfactants and dithiocarbamate- will be presented. Quartz tube multiatomizer for AAS was employed for atomization. Atomization conditions including composition of carrier gases and their flow rates and atomization temperature were optimized. 900 deg C was found as the optimum atomization temperature; over 900 deg C, peak area of Au signal decreased; in addition, peak shape was altered. A sharp maximum of 6 mL/min oxygen as the outer gas was observed. Another important point was that hydrogen-rich atmosphere caused signal depression. Analytical performance of this approach to generation and atomization will be discussed and perspectives of its future will be outlined. This work was supported by the GA ASCR (grant No. A400310507 and IAA400310704) and Institute of Analytical Chemistry of the ASCR, v.v.i. (project no. AV0Z40310501). This work also was supported from OYP (Faculty Development Program) from the Middle East Technical University

  20. Preconcentration and Atomization of Arsane in a Dielectric Barrier Discharge with Detection by Atomic Absorption Spectrometry.

    Science.gov (United States)

    Novák, Petr; Dědina, Jiří; Kratzer, Jan

    2016-06-01

    Atomization of arsane in a 17 W planar quartz dielectric barrier discharge (DBD) atomizer was optimized, and its performance was compared to that of a multiple microflame quartz tube atomizer (MMQTA) for atomic absorption spectrometry (AAS). Argon, at a flow rate of 60 mL min(-1), was the best DBD discharge gas. Free As atoms were also observed in the DBD with nitrogen, hydrogen, and helium discharge gases but not in air. A dryer tube filled with NaOH beads placed downstream from the gas-liquid separator to prevent residual aerosol and moisture transport to the atomizer was found to improve the response by 25%. Analytical figures of merit were comparable, reaching an identical sensitivity of 0.48 s ng (-1) As in both atomizers and limits of detection (LOD) of 0.15 ng mL(-1) As in MMQTA and 0.16 ng mL(-1) As in DBD, respectively. Compared to MMQTA, DBD provided 1 order of magnitude better resistance to interference from other hydride-forming elements (Sb, Se, and Bi). Atomization efficiency in DBD was estimated to be 100% of that reached in the MMQTA. A simple procedure of lossless in situ preconcentration of arsane was developed. Addition of 7 mL min(-1) O2 to the Ar plasma discharge resulted in a quantitative retention of arsane in the optical arm of the DBD atomizer. Complete analyte release and atomization was reached as soon as oxygen was switched off. Preconcentration efficiency of 100% was observed, allowing a decrease of the LOD to 0.01 ng mL(-1) As employing a 300 s preconcentration period. PMID:27159266

  1. 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%.

  2. 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.)

  3. Differential absorption radar techniques: water vapor retrievals

    Science.gov (United States)

    Millán, Luis; Lebsock, Matthew; Livesey, Nathaniel; Tanelli, Simone

    2016-06-01

    Two radar pulses sent at different frequencies near the 183 GHz water vapor line can be used to determine total column water vapor and water vapor profiles (within clouds or precipitation) exploiting the differential absorption on and off the line. We assess these water vapor measurements by applying a radar instrument simulator to CloudSat pixels and then running end-to-end retrieval simulations. These end-to-end retrievals enable us to fully characterize not only the expected precision but also their potential biases, allowing us to select radar tones that maximize the water vapor signal minimizing potential errors due to spectral variations in the target extinction properties. A hypothetical CloudSat-like instrument with 500 m by ˜ 1 km vertical and horizontal resolution and a minimum detectable signal and radar precision of -30 and 0.16 dBZ, respectively, can estimate total column water vapor with an expected precision of around 0.03 cm, with potential biases smaller than 0.26 cm most of the time, even under rainy conditions. The expected precision for water vapor profiles was found to be around 89 % on average, with potential biases smaller than 77 % most of the time when the profile is being retrieved close to surface but smaller than 38 % above 3 km. By using either horizontal or vertical averaging, the precision will improve vastly, with the measurements still retaining a considerably high vertical and/or horizontal resolution.

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

    Science.gov (United States)

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

    2004-01-01

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

  5. 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)

  6. Near resonant absorption by atoms in intense fluctuating laser fields

    International Nuclear Information System (INIS)

    The objective of this program was to make quantitative measurements of the effects of higher-order phase/frequency correlations in a laser beam on nonlinear optical absorption processes in atoms. The success of this program was due in large part to a unique experimental capability for modulating the extracavity beam of a stabilized (approx-lt 200 kHz) continuous-wave laser with statistically-well-characterized stochastic phase (or frequency) fluctuations, in order to synthesize laser bandwidths to ∼20 MHz (depending on noise amplitude), with profiles variable between Gaussian and Lorentzian (depending on noise bandwidth). Laser driven processes investigated included the following: (1) the optical Autler-Towns effect in the 3S1/2 (F = 2, MF = 2) → 3P3/2 (F = 3, MF = 3) two- level Na resonance, using a weak probe to the 4D5/2 level; (2) the variance and spectra of fluorescence intensity fluctuations in the two-level Na resonance; (3) the Hanle effect in the 1S0 - 3P1, transition at λ = 555.6 nm in 174 Yb; (4) absorption (and gain) of a weak probe, when the probe is a time-delayed replica of the resonant (with the two-level Na transition) pump laser; and (5) four-wave-mixing in a phase-conjugate geometry, in a sodium cell, and, finally, in a diffuse atomic sodium beam. The experimental results from these several studies have provided important confirmation of advanced theoretical methods

  7. Determination of cadmium in biodiesel using microemulsion and electrothermal atomization atomic absorption spectrometry.

    Science.gov (United States)

    Lima, Adriana S; Silva, Deise G; Teixeira, Leonardo S G

    2015-01-01

    This work aimed to prepare biodiesel microemulsions for the subsequent quantification of cadmium via graphite furnace atomic absorption spectrometry (GFAAS). The biodiesel samples were prepared using n-propanol as an emulsifier, 10% (v/v) nitric acid as the aqueous phase, and biodiesel. Pseudoternary phase diagrams were constructed to determine the microemulsion region with the specified components. The optimized conditions for microemulsion formation were 57.6% (v/v) n-propanol, 21.2% (v/v) biodiesel, and 21.2% (v/v) nitric acid solution. The stability of the microemulsified system was investigated using aqueous and organic standards, and the system was found to be stable for at least 240 min. The applied pyrolysis and atomization temperatures were 800 and 2000 °C, respectively, and 5 μg of aluminum was used as the chemical modifier. The obtained limits of detection and quantification were 0.2 and 0.5 μg kg(-1), respectively, and the characteristic mass was 1.6 pg. The precision, expressed as the relative standard deviation (% R.S.D., n = 10), was 2.5% for a sample with a cadmium concentration of 6.5 μg kg(-1). The accuracy was determined from addition and recovery experiments, with results varying from 93 to 108% recovery. This study demonstrates that the proposed method based on the use of a microemulsion formation in sample preparation can be applied as an efficient alternative for the determination of cadmium in biodiesel by GFAAS. Cadmium determination in biodiesel samples of different origins (soybean, corn, cotton, and sunflower) was evaluated after acid digestion using the inductively coupled plasma-mass spectrometry (ICP-MS) technique, and the obtained results were compared to the results obtained using the proposed method. The paired t test (95% confidence level) did not show significant differences. The concentrations of cadmium found ranged from 5.3 to 8.0 μg kg(-1). PMID:25381584

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

    Science.gov (United States)

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

    1987-01-01

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

  9. Micro-determination of ytterbium with electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This communication reports the use of a pyrolytic graphite coated tube, lined with tantalum-tungsten, and a local made atomic absorption spectrometer (Model WFD-Y3) for the determination of small amount Yb in pure Y2O3 and mixed rare earth oxides. It is found that the method proposed is sensitive, reproducible and simple in manipulation. Even as low as 0.2 μg Yb in one gram sample (n x 10-7) can be determined directly without pre-concentration. It is found experimentally that the optimum condition for drying is at 150 deg C. for 20 sec, ashing at 1000 deg C. for 20 sec and atomization at 2770 deg C. for 12 sec. Within the range 1.0-18ng Yb/ml the calibration curve of Yb is linear. Before injecting into the tube, the acidity of the sample solution should be ajusted to 0.1 to 2 M with nitric or hydrochloric acid. For 5ng Yb/ml, Al(III), Ca(II) and La(III) interference, when their amount present is 50 μg/ml or more. On the other hand, Cu(II), Fe(III), Mg(II), K(I) and Y(III) in amount up to 1 mg/ml do not interfere

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

    International Nuclear Information System (INIS)

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

  11. Rapid, easy multielement analysis of whole coal via slurry-injection atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    In recent years, a few laboratories have reported on the use of flame atomic absorption/emission methods for the analysis of solids directly, bypassing normal ashing and dissolution steps. We have developed an atomic absorption method for the direct analysis of whole coal by injection of powdered coal slurries into either flames or graphite furnaces. This paper greatly expands the preliminary observations of O'Reilly on the slurry-injection approach to flame AA analysis of coal. Our work is oriented toward a comprehensive exploration of the capabilities of this general approach for determining a wide variety of elements in some difficult-to-digest solid matrices such as coal, coal ash, oil shale, limestone, pigments, glasses, and selected ores. That is, solid matrices with relatively constant major component compositions. Most of our work has concerned flame atomization AA procedures, which are generally faster and more convenient than non-flame electrothermal atomization techniques. Ease of sample preparation plus greatly increased speed of analysis using a commonly available instrument are in the main advantages of this slurry injection AA method for coal analysis. Accuracies are certainly good enough for geochemical explorations, and are actually in the range of values reported for conventional AA determinations

  12. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of photon.In the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  13. Time amplifying techniques towards atomic time resolution

    Institute of Scientific and Technical Information of China (English)

    LI JingZhen

    2009-01-01

    High speed imaging technology has opened applications in many fields,such as collision,detonating,high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom shell.In principle,all of the transient processes need to be explained theoretically and,st the same time,the time amplifying technique is required for observations of these processes.The present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying techniques.It is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10~8-5×10~9 fps(frame per second)of the frame imaging.On the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10~7-10~(14) fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polarization and wavelength,and even quantum properties of photon.In the cascaded system of electromagnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite resolution.Then it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

  14. Ionisation of hydrogen-like atoms by a multiphoton absorption process

    International Nuclear Information System (INIS)

    The general expression for the amplitude of the probability of ionisation by a multiphoton absorption process is derived. Its non-relativistic limit is taken and the bipolar approximation is used for calculating the ionisation cross-section of hydrogen-like atoms. This latter involves the summation over intermediate virtual states by means of: a) a recursion relationship concerning angular functions, b) a particular technique which when applied to radial functions makes it possible to solve a system of inhomogeneous first-order differential equations. (authors)

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

    International Nuclear Information System (INIS)

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

  16. Determination of cadmium as pollutant in tobaccos using atomic absorption analysis

    International Nuclear Information System (INIS)

    Atomic absorption spectroscopy has been used for the determination of cadmium in non-aqueous media. It was found that the determination of cadmium in methanol is more accurate and more precise. In this case a concentration of 0.1 ppm was accurately determined with a relative deviation not exceeding 3.2%. Using this technique, the amount of cadmium in Syrian as well as in imported tobacco was determined and found to be in the range 0.64-1.11 ppm. It was also established that the cadmium concentration in imported tobacco is higher than that in Syrian tobacco. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-01

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

  18. Theoretical experimental study of the factors that govern the molybdenum absorption signal by means of electro thermic atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    The formation of molybdenum carbides in the atomizer, used in the electro thermic atomic absorption spectroscopy, is responsible for incomplete analyte removal in its analysis. This generates the apparition of the memory effect and little precision in the results. In this work, different variables that could affect the molybdenum absorption sign were investigated, as well as the influence of hydrochloric acid on the memory effect, by means of studies in the different stages: drying, calcination and atomization, and the samples deposition order in molybdenum solutions, either acidified or not acidified

  19. Optical technique for broadband microwave absorption spectroscopy in aqueous media

    International Nuclear Information System (INIS)

    Precise measurements of microwave absorption over a large range of frequencies in aqueous media are difficult to obtain and can result in conflicting results as a consequences of small differences in instrumentation. Traditional methods of microwave spectroscopy that make use of time-domain spectrometers or network analyzer systems provide only indirect measurement of the microwave absorption coefficient because they measure the real and imaginary parts of the dielectric constant, ε' and ε'', separately. The absorption coefficient must then be calculated from ε' and ε'' taking into account the geometry (e.g., of the waveguide and mode) among other factors. It has been shown that direct measurement of the microwave absorption coefficient α is possible using phase fluctuation optical heterodyne spectroscopy. Taking advantage of this hybrid optical-microwave technique the authors report on a broadband spectrometer with demonstrated accurate operation from 3 to 20 GHz

  20. Determination of antimony by using tungsten trap atomic absorption spectrometry

    International Nuclear Information System (INIS)

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 deg. C. Following the preconcentration step, the trap is heated to 895 deg. C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH4 solutions, H2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l-1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17

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

    Science.gov (United States)

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

    1967-01-01

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

  2. A passive measurement of dissociated atom densities in atmospheric pressure air discharge plasmas using vacuum ultraviolet self-absorption spectroscopy

    International Nuclear Information System (INIS)

    We demonstrate a method for determining the dissociation degree of atmospheric pressure air discharges by measuring the self-absorption characteristics of vacuum ultraviolet radiation from O and N atoms in the plasma. The atom densities are determined by modeling the amount of radiation trapping present in the discharge, without the use of typical optical absorption diagnostic techniques which require external sources of probing radiation into the experiment. For an 8.0 mm spark discharge between needle electrodes at atmospheric pressure, typical peak O atom densities of 8.5 × 1017 cm−3 and peak N atom densities of 9.9 × 1017 cm−3 are observed within the first ∼1.0 mm of plasma near the anode tip by analyzing the OI and NI transitions in the 130.0–132.0 nm band of the vacuum ultraviolet spectrum

  3. Determination of Arsenic in Palm Kernel Expeller using Microwave Digestion and Graphite Furnace Atomic Absorption Spectrometry Method

    OpenAIRE

    Abdul Niefaizal Abdul Hammid; Ainie Kuntom; RazaIi Ismail; Norazilah Pardi

    2013-01-01

    A study on the method to determine arsenic in palm kernel expeller wascarried out. Microwave digestion technique is widely applied in the analytical chemistry field. In comparison to conventional sample digestion method, the microwave technique is simple, reduced contamination, usage of safe reagent and matrix completely digested. A graphite furnace atomic absorption spectrometry method was used for the total determination of arsenic in palm kernel expeller. Arsenic was extracted from palm ke...

  4. Quantitative effective atomic number imaging using simultaneous x-ray absorption and phase shift measurement

    International Nuclear Information System (INIS)

    A scanning type x-ray imaging system which measures the absorption and differential phase shift in a material quantitatively and simultaneously has been developed. The absorption and differential phase are used to obtain the effective atomic number of organic material samples which closely reflects their chemical composition. An effective atomic number map of polymer fibers has been obtained. The experimentally obtained effective atomic numbers of these polymers agree well with the corresponding calculated values.

  5. Optimization of trace molybdenum content determination in human nails by graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The accurate determination of molybdenum (Mo) in biological materials is of considerable importance in medical science because of the essential role played by this element in human metabolism. Molybdenum is a component of enzymes responsible for the initial stages of nitrogen, carbon and sulfur metabolism of plants, animals and humans. This element is usually determined by neutron activation analysis (NAA) in variety of samples, but direct measurement of low levels of molybdenum in biological samples by NAA is difficult. Recently instrumental analysis procedures such as atomic absorption spectrometry (AAS) have been used in clinical measurements for determination of many trace elements in the biological samples. These techniques are much simpler and cheaper than NAA. In this paper we are reporting a method of sample preparation for determining molybdenum by using graphite furnace atomic absorption spectrometry (GF-AAS). This method is the most readily available technique for determination of molybdenum at the ng/g level in biological samples. It can be used for the routine hospital laboratory determination of molybdenum and has appropriate sensitivity and simplicity. The best and reliable results for molybdenum analysis was achieved by digestion of nails in HNO3 2 N and was determined in the range from 0.11 to 5.10 μg/g

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-01

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

  7. Comparison of electrothermal atomization diode laser Zeeman- and wavelength-modulated atomic absorption and coherent forward scattering spectrometry

    International Nuclear Information System (INIS)

    Atomic absorption and coherent forward scattering spectrometry by using a near-infrared diode laser with and without Zeeman and wavelength modulation were carried out with graphite furnace electrothermal atomization. Analytical curves and limits of detection were compared. The magnetic field was modulated with 50 Hz, and the wavelength of the diode laser with 10 kHz. Coherent forward scattering was measured with crossed and slightly uncrossed polarizers. The results show that the detection limits of atomic absorption spectrometry are roughly the same as those of coherent forward scattering spectrometry with crossed polarizers. According to the theory with bright flicker noise limited laser sources the detection limits and linear ranges obtained with coherent forward scattering spectrometry with slightly uncrossed polarizers are significantly better than those obtained with crossed polarizers and with atomic absorption spectrometry. This is due to the fact that employing approaches of polarization spectroscopy reduce laser intensity fluctuations to their signal carried fractions

  8. Gamma absorption technique in elemental analysis of composite materials

    International Nuclear Information System (INIS)

    Highlights: ► Application of gamma-ray absorption technique in elemental analysis. ► Determination of elemental composition of some bronze and gold alloys. ► Determination of some heavy elements in water. - Abstract: Expressions for calculating the elemental concentrations of composite materials based on a gamma absorption technique are derived. These expressions provide quantitative information about elemental concentrations of materials. Calculations are carried out for estimating the concentrations of copper and gold in some alloys of bronze and gold. The method was also applied for estimating the concentrations of some heavy elements in a water matrix highlighting the differences with photon attenuation measurements. Theoretical mass attenuation coefficient values were obtained using the WinXCom program. A high-resolution gamma-ray spectrometry based on high purity germanium detector (HPGe) was employed to measure the attenuation of a strongly collimated monoenergetic gamma beam through samples.

  9. Permanent modification in electrothermal atomic absorption spectrometry — advances, anticipations and reality

    Science.gov (United States)

    Tsalev, Dimiter L.; Slaveykova, Vera I.; Lampugnani, Leonardo; D'Ulivo, Alessandro; Georgieva, Rositsa

    2000-05-01

    Permanent modification is an important recent development in chemical modification techniques which is promising in view of increasing sample throughput with 'fast' programs, reducing reagent blanks, preliminary elimination of unwanted modifier components, compatibility with on-line and in situ enrichment, etc. An overview of this approach based on the authors' recent research and scarce literature data is given, revealing both success and failure in studies with permanently modified surfaces (carbides, non-volatile noble metals, noble metals on carbide coatings, etc.), as demonstrated in examples of direct electrothermal atomic absorption spectrometric (ETAAS) applications to biological and environmental matrices and vapor generation (VG)-ETAAS coupling with in-atomizer trapping of hydrides and other analyte vapors. Permanent modifiers exhibit certain drawbacks and limitations such as: poorly reproducible treatment technologies — eventually resulting in poor tube-to-tube repeatability and double or multiple peaks; impaired efficiency compared with modifier addition to each sample aliquot; relatively short lifetimes; limitations imposed on temperature programs, the pyrolysis, atomization and cleaning temperatures being set somewhat lower to avoid excessive loss of modifier; applicability to relatively simple sample solutions rather than to high-salt matrices and acidic digests; side effects of overstabilization, etc. The most important niches of application appear to be the utilization of permanently modified surfaces in coupled VG-ETAAS techniques, analysis of organic solvents and extracts, concentrates and fractions obtained after enrichment and/or speciation separations and direct ETAAS determinations of highly volatile analytes in relatively simple sample matrices.

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

    International Nuclear Information System (INIS)

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

  11. Direct observation of transient fluorine atoms with 25-μm wavelength-stabilized diode laser absorption

    International Nuclear Information System (INIS)

    Through the use of continuous diode laser absorption, detection of transient fluorine atoms with an initial number density in the range of 1014 cm-3 has been demonstrated. A crucial part of the continuous-detection technique was laser frequency stabilization with a reference cell of atomic fluorine with Zeeman modulation of the absorption lines to generate a feedback signal. Long-term wavelength stability was demonstrated with second-harmonic phase-sensitive detection of the second-derivative signal for periods up to several hours. For determination of the short-term wavelength stability in the range of microseconds to seconds, a transient signal was generated by photolysis of F2 with an excimer laser at 308 nm. The initial diode laser absorption was compared to a calculated value obtained from the measured excimer laser fluence, the known dissociation cross section of F2, and the atomic fluorine absorption cross section, which included a statistical population distribution, the finite bandwidth of the laser diode, and the effects of pressure broadening. The observed absorption was approximately 33% less than the calculated value, possibly because of the diode laser's wavelength instability on the time scale of a few seconds, which is consistent with an observed amplitude instability from pulse to pulse when pulsed at 1--10 Hz

  12. Ionization of hydrogen atom by X-ray absorption in the presence of optical laser field

    International Nuclear Information System (INIS)

    The absorption of X-rays in hydrogen atom considering the irradiation of the target by an intense optical laser of frequency ω is studied. It is found that the terms of the modified scattering amplitude has different dependence on polarization vectors of X-ray fields and laser fields. There is resonance in the differential cross section for absorption at different frequencies when ω (the laser frequency) becomes nearly equal to atomic transition frequency. (author). 21 refs., 2 figs

  13. Vacuum Ultraviolet Absorption Measurements of Atomic Oxygen in a Shock Tube.

    Science.gov (United States)

    Meyer, Scott Andrew

    The absorption of vacuum ultraviolet light by atomic oxygen has been measured in the Electric Arc-driven Shock Tube (EAST) Facility at NASA-Ames Research Center. This investigation demonstrates the instrumentation required to determine atomic oxygen concentrations from absorption measurements in impulse facilities. A shock wave dissociates molecular oxygen, producing a high temperature sample of atomic oxygen in the shock tube. A probe beam is generated with a Raman-shifted ArF excimer laser. By suitable tuning of the laser, absorption is measured over a range of wavelengths in the region of the atomic line at 130.49 nm. The line shape function is determined from measurements at atomic oxygen densities of 3 times 10 ^{17} and 9 times 10^{17} cm ^{-3}. The broadening coefficient for resonance interactions is deduced from this data, and this value is in accord with available theoretical models.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-05

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

  15. Determination of lithium in coloured alcoholic beverages by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. Lithium was first found in ashes from wine in 1878, and its presence was later confirmed by spectroscopy, but its determination in wine and beverages is not well documented, unlike the extensive research reported on other metals. Several methods can be implemented for determination of lithium, involving the use of atomic spectroscopy techniques. This paper reports on an analytical optimization to determine lithium by atomic absorption spectrometry (AAS). Good results in reproducibility, accuracy and precision were obtained. No significant interference was found. The method was applied for determination of lithium in six rum samples, eight brandy samples, four vermouth samples, eight whisky samples and two bourbon samples. The value of lithium content in samples ranges from 0,33 to 1,48 μg/ml. Recovery experiments were carried out in order to evaluate the accuracy of the method in samples determination. The values obtained ranges from 95,71% to 98%. The precision of the method in that samples determination was evaluated through variation coefficients. The values obtained ranges from 7,2% to 2,5%. The results have been statistically compared with those obtained using the Inductively Coupled Plasma Atomic Emission Spectrometry (ICP/AES) and reaches a 95% level of significance.

  16. The use of atomic absorption spectroscopy to measure arsenic, selenium, molybdenum, and vanadium in water and soil samples from uranium mill tailings sites

    Energy Technology Data Exchange (ETDEWEB)

    Hollenbach, M.H.

    1988-01-01

    The Technical Measurements Center (TMC) was established to support the environmental measurement needs of the various DOE remedial action programs. A laboratory intercomparison study conducted by the TMC, using soil and water samples from sites contaminated by uranium mill tailings, indicated large discrepancies in analytical results reported by participating laboratories for arsenic, selenium, molybdenum, and vanadium. The present study was undertaken to investigate the most commonly used analytical techniques for measuring these four elements, ascertain routine and reliable quantification, and assess problems and successes of analysts. Based on a survey of the technical literature, the analytical technique of atomic absorption spectroscopy was selected for detailed study. The application of flame atomic absorption, graphite furnace atomic absorption, and hydride generation atomic absorption to the analysis of tailings-contaminated samples is discussed. Additionally, laboratory sample preparation methods for atomic absorption spectroscopy are presented. The conclusion of this report is that atomic absorption can be used effectively for the determination of arsenic, selenium, molybdenum, and vanadium in water and soil samples if the analyst understands the measurement process and is aware of potential problems. The problem of accurate quantification of arsenic, selenium, molybdenum, and vanadium in water and soil contaminated by waste products from uranium milling operations affects all DOE remedial action programs (Surplus Facilities Management Program (SFMP), Formerly Utilized Site Remedial Action Program (FUSRAP), and Uranium Mill Tailings Remedial Action Program (UMTRAP)), since all include sites where uranium was processed. 96 refs., 9 figs.

  17. Estimation of lead and cadmium in various food commodities by electrothermal atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    The determination of lead and cadmium was carried out in various types of food commodities including poultry farm chicken eggs, integrated diet of winter season for the inhabitants of Rawalpindi/Islamabad area and different brands of baby cereals, employing electrothermal atomic absorption spectrophotometric technique. The results showed that integrated diet contained the highest amount of lead whereas the maximum concentration of cadmium was observed in samples of baby cereals. The effect of mechanical food processing on the concentration levels of these elements was discussed. The results obtained were compared with the reported values for other countries. Intake values of these toxic elements through these food articles were calculated and compared with the tolerance levels of WHO. (author)

  18. Determination of molybdenum in silicates through atomic absorption spectrometry using pre-concentration by active carbon

    International Nuclear Information System (INIS)

    An analytical procedure for molybdenum determination in geological materials through Atomic Absorption Spectrometry, after pre-concentration of the Mo-APDC complex in activated carbon, has been developed, which is needed in order to reduce the dilution effect in the sample decomposition. During the development of this method the influence of pH, the amount of APDC for complexation of Mo and the interference of Fe, Ca, Mn, Al, K, Na, Mg and Ti were tested. It was shown that none of these causes any significant effect on the Mo determination proposed. The results of the analysis at the international geochemical reference samples JB-1 (basalt) and GH (granite) were very accurate and showed that the detection limit in rocks (1,00g) is 0,6 ppm, when using sample dilution of 1 ml and microinjection techniques. (author)

  19. Estimation of lead and zinc in human hair using atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Trace elements analysis in hair can be useful in studying the impact of environmental and dietary factors on human in general for lead and zinc content in hair. Samples of people of different age groups, sex with varied living habits of the individual living in different areas of Sind, urban as well as rural areas were of special interest to be studied to find correlation of socioeconomic factors and the presence of these elements in hair samples. The purpose of this study was to determine whether age, sex and physiological status and environmental pollution affect composition of hair. The method of sample preparation and use of atomic absorption techniques providing unequivocal and direct estimation of metals in ppm/ppb range to arrive upon conclusion. (author)

  20. ANALYSIS OF VARIOUS METAL IONS IN SOME MEDICINAL PLANTS USING ATOMIC ABSORPTION SPECTROPHOTOMETER

    Directory of Open Access Journals (Sweden)

    Y.L. Ramachandra*, C. Ashajyothi and Padmalatha S. Rai

    2012-07-01

    Full Text Available Metal ions such as iron , lead, copper, nickel, cadmium , chromium and zinc were investigated in medicinally important plants Alstonia scholaris, Tabernaemontana coronariae, Asparagus racemosus, Mimosa pudica, Leucas aspera and Adhatoda vasica applying atomic absorption spectrophotometer techniques. The purpose of this study was to standardize various metal ion Contamination in indigenous medicinal plants. Maximum concentration of lead was present in Leucas aspera and Adhatoda vasica followed by Alstonia scholaris, Tabernaemontana coronariae and Asparagus racemosus. The concentration of lead in Mimosa pudica was below the detectable level. The maximum concentration of zinc was detected in Adhatoda vasica followed by Leucas aspera, Asparagus racemosus, Tabernaemontana coronariae, Alstonia scholaris and Mimosa pudica. The concentration of Cadmium, nickel and chromium was below the detectable level.

  1. New cryogenic trap design for speciation analysis of arsenic by hydride generation-atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Milan; Kratzer, Jan; Dědina, Jiří

    Praha, 2014. s. 240-240. 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 : atomic absorption spectrometry * hydride generation * cryogenic trapping Subject RIV: CB - Analytical Chemistry, Separation

  2. Selenium determination in biological material by atomic absorption spectrophotometry in graphite furnace and using vapor generation

    International Nuclear Information System (INIS)

    The applicability of the atomic absorption spectrophotometry to the determination of selenium in biological material using vapor generation and electrothermal atomization in the graphite furnace was investigated. Instrumental parameters and the analytical conditions of the methods were studied. Decomposition methods for the samples were tested, and the combustion in the Wickbold apparatus was chosen. (author)

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Solis A, N. A.

    2015-07-01

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

  5. Absorption of twisted light by a mesoscopic atomic target

    Science.gov (United States)

    Peshkov, A. A.; Serbo, V. G.; Fritzsche, S.; Surzhykov, A.

    2016-06-01

    The excitation of a hydrogen-atom target by a twisted Bessel light beam is investigated. The atoms are assumed to have a Gaussian spatial distribution in the target. Theoretical analysis is performed within a nonrelativistic framework using a first-order perturbation approach and density matrix formalism. By using this theory, we derive the expressions for excitation cross sections and for alignment parameters of the excited atomic state. In particular, we make calculations for the 1s\\to 2p transition caused by the interaction of Bessel beams with the atomic target. For this transition, we analyze the population of magnetic sublevels for the excited 2p state and study how it is affected by the projection of the total angular momentum of incident light. The calculations indicate that the projection of the total angular momentum of the incident Bessel beam affects the alignment of atoms for sufficiently small targets with size less than 200 nm. This can be observed experimentally by measuring the linear polarization of the subsequent fluorescent light.

  6. Determination of tin in biological reference materials by atomic absorption spectrophotometry and neutron activation analysis

    International Nuclear Information System (INIS)

    Because of a lack of reliable analytical techniques for the determination of tin in biological materials, there have been no reference materials certified for this element. However, the authors' experience has shown that it is feasible to use both atomic absorption and nuclear activation techniques at least for selected matrices. Therefore, an investigation was undertaken to determine tin in several biological materials such as non-fat milk powder (NBS-SRM-1549), citrus leaves (NBS-SRM-1572), total diet (NIST-SRM-1548), mixed diet (NBS-RM-8431), and USDIET-I by atomic absorption spectrophotometry (AAS) and neutron activation analysis (NAA). AAS-ashed samples were extracted with MIBK and assayed using a Perkin Elmer model 5000 apparatus. NAA was carried out by irradiating the samples at the NIST reactor in the RT-4 facility and counting with the help of a Ge(Li) detector connected to a multichannel analyzer. The concentration of tin measured by both AAS and NAA agree well for USDIET-I, total diet, citrus leaves and non-fat milk powder (the concentration ranges for tin in these matrices were from 0.0025 to 3.8 micro g/g). However, in the case of mixed diet (RM-8431), the mean values found were 47 ± 5.6 (n = 19) by AAS and 55.5 ± 2.5 (n = 6) by INAA. Since RM-8431 is not certified it is difficult to draw conclusions. For apple and peach leaves, a distillation step was required. The results were apple leaves 0.085 ± 0.015 (n = 10) by AAS and < 0.2 (n = 3) by RNAA; for peach leaves 0.077 ± 0.02 (n = 9) by AAS and < 0.1 (n = 3) by RNAA. All concentrations are expressed in micro g/g dry weight

  7. Optical pumping effect in absorption imaging of F=1 atomic gases

    CERN Document Server

    Kim, Sooshin; Noh, Heung-Ryoul; Shin, Y

    2016-01-01

    We report our study of the optical pumping effect in absorption imaging of $^{23}$Na atoms in the $F=1$ hyperfine spin states. Solving a set of rate equations for the spin populations under a probe beam, we obtain an analytic expression for the optical signal of the $F=1$ absorption imaging. Furthermore, we verify the result by measuring the absorption spectra of $^{23}$Na Bose-Einstein condensates prepared in various spin states with different probe beam pulse durations. The analytic result can be used in quantitative analysis of $F=1$ spinor condensate imaging and readily applied to other alkali atoms with $I=3/2$ nuclear spin such as $^{87}$Rb.

  8. Reduction of interference fringes in absorption imaging of cold atom cloud using eigenface method

    Institute of Scientific and Technical Information of China (English)

    Xiaolin Li; Min Ke; Bo Yan; Yuzhu Wang

    2007-01-01

    Eigenface method used in face recognition is introduced to reduce the pattern of interference fringes appearing in the absorption image of cold rubidium atom cloud trapped by an atom chip. The standard method for processing the absorption image is proposed, and the origin of the interference fringes is analyzed. Compared with the standard processing method which uses only one reference image, we take advantage of fifty reference images and reconstruct a new reference image which is more similar to the absorption image than all of the fifty original reference images. Then obvious reduction of interference fringes can be obtained.

  9. Application of a multi-pass absorption cell for measurement of sputtered tungsten atoms' density

    International Nuclear Information System (INIS)

    A dedicated gas discharge tube equipped with a hollow cathode made of tungsten is setup for sputtering of W atoms. A multi-pass White type absorption cell is designed to increase the sensitivity of the absorption method. The optical system consists of three externally mounted aluminium-coated spherical mirrors with 70 cm radius of curvature. Measurements of the cell relative transmittance in the UV and visible spectral regions are carried out. Time-resolved measurements of sputtered ground-state tungsten atoms' density in 2-pass configuration, as well as assessment of the diffusion coefficient of these atoms in argon at 350 K temperature are made.

  10. Quantum interference in attosecond transient absorption of laser-dressed helium atoms

    CERN Document Server

    Chen, Shaohao; Gaarde, Mette B; Schafer, Kenneth J

    2013-01-01

    We calculate the transient absorption of an isolated attosecond pulse by helium atoms subject to a delayed infrared (\\ir) laser pulse. With the central frequency of the broad attosecond spectrum near the ionization threshold, the absorption spectrum is strongly modulated at the sub-\\ir-cycle level. Given that the absorption spectrum results from a time-integrated measurement, we investigate the extent to which the delay-dependence of the absorption yields information about the attosecond dynamics of the atom-field energy exchange. We find two configurations in which this is possible. The first involves multi photon transitions between bound states that result in interference between different excitation pathways. The other involves the modification of the bound state absorption lines by the IR field, which we find can result in a sub-cycle time dependence only when ionization limits the duration of the strong field interaction.

  11. X-ray absorption spectroscopy: EXAFS and XANES - A versatile tool to study the atomic and electronic structure of materials

    International Nuclear Information System (INIS)

    X-ray absorption spectroscopy (XAS) had been an essential tool to gather spectroscopic information about atomic energy level structure in the early decades of this century. The correct interpretation of the oscillatory structure in the x-ray absorption cross-section above the absorption edge has transformed XAS from a spectroscopic tool to a structural technique. EXAFS (Extended X-ray Absorption Fine Structure) yields information about the interatomic distances, near neighbor coordination numbers, and lattice dynamics. XANES (X-ray Absorption Near Edge Structure), on the other hand, gives information about the valence state, energy bandwidth and bond angles. Today, there are about 50 experimental stations in various synchrotrons around the world dedicated to collecting x-ray absorption data from the bulk and surfaces of solids and liquids. In this chapter, they will give the basic principles of XAS, explain the information content of essentially two different aspects of the absorption process leading to EXAFS and XANES, and discuss the source and sample limitations

  12. Left-handedness without absorption in the four-level Y-type atomic medium

    International Nuclear Information System (INIS)

    In this paper we have investigated three external fields interacting with the four-level Y-type atomic system described by the density-matrix approach. The results show that left-handedness with zero absorption is achieved. The zero absorption property displays the possibility of manipulation by varying the phase and the intensity of the coupling field. Also, the zero absorption property may be used to amplify the evanescent waves that have been lost in imaging by traditional lenses. We propose an approach to obtain a negative refractive medium with zero absorption and the possibility of enhanceing the imaging resolution in realizing 'superlenses'. (classical areas of phenomenology)

  13. Near resonant absorption by atoms in intense fluctuating fields

    International Nuclear Information System (INIS)

    Using an atomic beam apparatus, we have carried out comprehensive measurements of fluorescence intensity, and fluctuations (variance) in the fluorescence intensity, from the 3S1/2 (F = 2, MF = 2) → 3P3/2 (F = 3, MF = 3) transition in atomic sodium, in a laser driving field on which well-characterized synthesized phase fluctuations have been imposed. These data are taken as a function of detuning of the laser from exact resonance with the transition, and for laser fields modulated with characteristically different bandwidths and amplitudes of phase noise. The experimental results are compared in detail with predictions of recently developed theoretical treatments. The methods are being extended to experimental studies of the role of phase fluctuations in four-wave mixing. 4 refs., 1 fig

  14. 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.

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

    International Nuclear Information System (INIS)

    The on-line atomization of gold volatile species was studied and the results were compared with thermodynamic calculations in several quartz atomizers, namely: diffusion flame, flame-in-gas-shield, flame-in-plain-tube, externally heated T-tube and externally heated flame-in-T-tube. Atomization mechanism in the explored devices is proposed, where volatile species are converted to thermodynamically stable AuH at elevated temperature over 500 °C and then atomized by an interaction with a cloud of hydrogen radicals. Because of its inherent simplicity and robustness, diffusion flame was employed as a reference atomizer. It yielded atomization efficiency of 70 to 100% and a very good long time reproducibility of peak area sensitivity: 1.6 to 1.8 s μg−1. Six and eleven times higher sensitivity, respectively, was provided by atomizers with longer light paths in the observation volume, i.e. externally heated T-tube and externally heated flame-in-T-tube. The latter one, offering limit of detection below 0.01 μg ml−1, appeared as the most prospective for on-line atomization. Insight into the mechanism of atomization of gold volatile species, into the fate of free atoms and into subsequent analyte transfer allowed to assess possibilities of in-atomizer preconcentration of gold volatile species: it is unfeasible with quartz atomizers but a sapphire tube atomizer could be useful in this respect. - Highlights: • On-line atomization of gold volatile species for AAS in quartz devices was studied. • Atomization mechanism was proposed and atomization efficiency was estimated. • Possibilities of in-atomizer preconcentration of gold volatile species were assessed

  16. Absorption Spectra of a Three-Level Atom Embedded in a PBG Reservoir

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ke; ZHANG Han-Zhuang

    2007-01-01

    We introduce the 'decay rate' terms into the density matrix equations of an atom embedded in a photonic band gap (PSG)reservoir successfully.By utilizing the master equations,the probe absorption spectra and the refractivity properties of a three-level atom in the PBG reservoir are obtained.The interaction between the atom and the PBG reservoir as well as the effects of the quantum interference on the absorption of the atom has also been taken into account.It is interesting that two different types of the anomalous dispersion relations of refractivity are exhibited in one dispersion line.The methodology used here can be applied to theoretical investigation of quantum interference effects of other atomic models embedded in a PBG reservoir.

  17. Element-selective trace detection of toxic species in environmental samples using chromatographic techniques and derivative diode laser absorption spectrometry

    Science.gov (United States)

    Koch, J.; Zybin, A.; Niemax, K.

    1998-10-01

    Very sensitive laser absorption techniques based on a double-beam scheme with logarithmic processing of the detector signals and wavelength modulation of laser diodes are presented. Detection limits equivalent to 10-7 absorption per square root of detection bandwidth are obtained if sufficient laser power is available and if the absorption is also subject to additional modulation. The analytical versatility of these techniques is demonstrated by quantitative analysis of very low concentrations of (i) Cr(VI) species in tap water and (ii) chlorinated poly-aromatics (chlorophenols) in plant extracts, both after chromatographic separation. The atomic absorption measurements were performed in an air-acetylene flame (Cr) and in a low-pressure microwave-induced plasma (chlorophenols).

  18. Hydrogen atom position in hydrated iodide anion from x-ray absorption near edge structure

    International Nuclear Information System (INIS)

    Hydrogen atom position in the hydrated iodide anion complex is determined from X-ray Absorption Near Edge Structure (XANES) of an aqueous iodide solution at both the K- and L-edges. The spectra are compared with the theoretical ones calculated by using the FEFF method for several model geometries having hydrogen atoms at different positions. Satisfactory agreements are obtained from models with an almost linear alignment of iodine-hydrogen-oxygen atoms, indicating the capability of the XANES analysis when it is combined with the multiple scattering calculations as a method to detect the positions of hydrogen atoms in the first coordination sphere. (author)

  19. Manipulating absorption and diffusion of H atom on graphene by mechanical strain

    OpenAIRE

    Ming Yang; Argo Nurbawono; Chun Zhang; Rongqin Wu; Yuanping Feng; Ariando

    2011-01-01

    Effects of the tensile strain on absorption and diffusion of hydrogen atoms on graphene have been studied by first-principles calculations. Our calculations suggested that there exists a barrier of 0.22 eV for H atom to diffuse from free space to graphene. The barrier originates from the transition of the hybridization of the H-binded carbon atom in graphene from sp2 to sp3, and is robust against the tensile strain. It was also found that, first, the in-plane diffusion of H atoms on graphene ...

  20. Near resonant absorption by atoms in intense fluctuating fields

    International Nuclear Information System (INIS)

    We have completed a comprehensive study of the effects of phase/frequency fluctuations in the incident laser field on the fluorescence intensity from the 3S1/2 (F = 2, MF = 2) to 3P3/2 (F = 3, MF = 3) transition to atomic sodium. The experiments were carried out in an atomic beam apparatus with a laser driving field on which well-characterized synthesized phase-fluctuations were imposed. The mean fluorescence intensity and the fluctuations in the intensity were measured as a function of detuning of the driving field from the resonance frequency of the transition, and for several different laser powers and bandwidths of laser noise. Power spectra of the intensity fluctuations were measured for a wide range of parameters and the effects of correlated amplitude and phase fluctuations were probed. Detailed comparisons between theoretical predictions and experimental measurements were carried out, and a theoretical model was developed to include the effects of residual Doppler broadening and the nonuniform spatial intensity profile of the driving laser. Experimental investigations of effects of laser phase-noise on degenerate four- wave-mixing have been started

  1. Dielectric barrier discharge plasma atomizer for hydride generation atomic absorption spectrometry—Performance evaluation for selenium

    International Nuclear Information System (INIS)

    Atomization of selenium hydride in a quartz dielectric barrier discharge (DBD) atomizer was optimized and its performance was compared to that of the externally heated quartz multiatomizer. Argon was found as the best DBD discharge gas employing a flow rate of 75 ml min−1 Ar while the DBD power was optimized at 14 W. The detection limits reached 0.24 ng ml−1 Se in the DBD and 0.15 ng ml−1 Se in the multiatomizer. The tolerance of DBD to interferences is even better than with the multiatomizer. - Highlights: • SeH2 atomization in a dielectric barrier discharge (DBD) was optimized for AAS. • Atomizer performance was compared for DBD and externally heated quartz atomizer. • Detection limits were quantified and interferences were studied in both atomizers. • Atomization efficiency in the DBD was estimated

  2. Entanglement-preserving absorption of single SPDC photons by a single atom

    CERN Document Server

    Huwer, J; Piro, N; Schug, M; Dubin, F; Eschner, J

    2011-01-01

    We study the controlled interaction between a single trapped Ca40+ ion and single photons belonging to entangled photon pairs. The ion is prepared as a polarization-sensitive single-photon absorber; the absorption of one photon from a pair is marked by a quantum jump of the atomic state and heralded by the coincident detection of the entangled partner photon. For three polarization basis settings of absorption and detection of the herald, we find maximum coincidences always for orthogonal polarizations. Tomographic reconstruction of the biphoton quantum state from the absorption-herald coincidences reveals 93% overlap with the maximally entangled state. This proves that the polarization entanglement shared by the photon pair is preserved in the absorption process and converted to transient photon-atom entanglement.

  3. Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

    Science.gov (United States)

    Jora, M. Z.; Nóbrega, J. A.; Rohwedder, J. J. R.; Pasquini, C.

    2015-01-01

    An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271-453 nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24 μg L- 1, and a relative standard deviation of 3%.

  4. Energy absorption, ionization, and harmonic emission in laser-irradiated atomic clusters

    OpenAIRE

    Kundu, M.

    2007-01-01

    The excellent coupling of laser light to atomic clusters is a known, experimentally established fact. However, the physical mechanism of laser absorption is still controversially discussed. Linear resonance (LR) absorption occurs for sufficiently long laser pulses of optical or longer wavelengths. Here the Mie-plasma frequency initially rises above the laser frequency, then drops due to cluster expansion and therefore meets the laser frequency at some point. Instead, in few-cycle laser pulses...

  5. Pulse nebulization atomic absorption spectrometry after preconcentration from acidic media

    International Nuclear Information System (INIS)

    The possible advantages of the combination: chlorinated solvent extraction - pulse nebulization, abomic absorption spectrometry (AAS), as well as application of this method to multi-element determination of several important trace elements in biological samples is investigated. Hexamethyleneammonium hexamethylenedithiocarbamate (HMA-HMDTC) and ammonium pyrrolidinedithiocarbamate (APDC) as regents and CCl4, CHCl3, butylacetate (BuOAc) and methylisobutyl ketone (MIBK) as organic solvents are utilized. There is a tendency that CCl4 is the best solvent and MIBK - the worst. The study of extraction efficiency versus the ratio of aqueous-to-organic phase also shows the advantages of chlorinated solvents for extraction from acidic media. Better results are obtained with HMA-HMDTC as a reagent for Cu and Pb, whereas, for Cd extraction APDC gave a more efficient extraction. Chloroform shows a higher sensitivity enhancement factor, especially for volatile and/or chloride-forming elements. The extraction is successfully applied to determination of Cd, Cu and Pb in tissues of alfalfa, cabbage, carrots, onions, potatoes and wheat, as well as two standard reference materials. The results are in good agreement with the certified values

  6. Determination of traces of cadmium in zinc by flameless atomic absorption spectrophotometry after extraction

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, A.; Willmann, K.H.; Simon, F.J.

    1985-01-01

    The suitability of dithizone, diethyldithiocarbamate and tetramethylendithiocarbamate as chelating agents for the extraction-photometric cadmium determination by flameless atomic absorption spectrophotometry in the presence of zinc was investigated. It has been found that the extraction of the dithizone chelate by carbon tetrachloride permits an uninfluenced determination of cadmium in the presence of a zinc excess up to 10/sup 5/. Therefore the use of flameless atomic absorption spectrophotometry raises the selectivity as compared to photometry, because photometry only permits a 1000-fold excess of zinc. With this method 2x10/sup -4/% of cadmium in zinc can be determined without further corrections of matrix effects.

  7. Comparison of liposome entrapment parameters by optical and atomic absorption spectrophotometry.

    Science.gov (United States)

    Yoss, N L; Popescu, O; Pop, V I; Porutiu, D; Kummerow, F A; Benga, G

    1985-01-01

    Methods for the complete characterization of liposomes prepared by ether-injection are described in detail. The validity of atomic absorption spectrophotometry for measuring markers of trapped volume was checked by comparative determinations of markers with established optical spectrophotometrical methods. The favorable results using atomic absorption spectrophotometry to quantitate the marker Mn2+ are of particular relevance as manganese ion is also the paramagnetic probe in n.m.r. measurements of water permeability of liposomes; our results indicate that in such measurements no other marker need be incorporated. PMID:3986305

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

    DEFF Research Database (Denmark)

    Sidenius, U; Gammelgaard, Bente

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Carlos Elielton do Espírito Santo

    2014-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Esteban Pérez-López

    2014-11-01

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

  11. Observing random walks of atoms in buffer gas through resonant light absorption

    CERN Document Server

    Aoki, Kenichiro

    2016-01-01

    Using resonant light absorption, random walk motions of rubidium atoms in nitrogen buffer gas are observed directly. The transmitted light intensity through atomic vapor is measured and its spectrum is obtained, down to orders of magnitude below the shot noise level to detect fluctuations caused by atomic motions. To understand the measured spectra, the spectrum for atoms performing random walks in a gaussian light beam is computed and its analytical form is obtained. The spectrum has $1/f^2$ ($f$: frequency) behavior at higher frequencies, crossing over to a different, but well defined behavior at lower frequencies. The properties of this theoretical spectrum agree excellently with the measured spectrum. This understanding also enables us to obtain the diffusion constant, the photon cross section of atoms in buffer gas and the atomic number density, from a single spectral measurement. We further discuss other possible applications of our experimental method and analysis.

  12. Observing random walks of atoms in buffer gas through resonant light absorption

    Science.gov (United States)

    Aoki, Kenichiro; Mitsui, Takahisa

    2016-07-01

    Using resonant light absorption, random-walk motions of rubidium atoms in nitrogen buffer gas are observed directly. The transmitted light intensity through atomic vapor is measured, and its spectrum is obtained, down to orders of magnitude below the shot-noise level to detect fluctuations caused by atomic motions. To understand the measured spectra, the spectrum for atoms performing random walks in a Gaussian light beam is computed, and its analytical form is obtained. The spectrum has 1 /f2 (f is frequency) behavior at higher frequencies, crossing over to a different, but well-defined, behavior at lower frequencies. The properties of this theoretical spectrum agree excellently with the measured spectrum. This understanding also enables us to obtain the diffusion constant, the photon cross section of atoms in buffer gas, and the atomic number density from a single spectral measurement. We further discuss other possible applications of our experimental method and analysis.

  13. Absorption spectroscopy of cold caesium atoms confined in a magneto-optical trap

    Institute of Scientific and Technical Information of China (English)

    Yan Shu-Bin; Liu Tao; Geng Tao; Zhang Tian-Cai; Peng Kun-Chi; Wang Jun-Min

    2004-01-01

    Absorption spectra of cold caesium atoms confined in a magneto-optical trap are measured around D2 line at 852nm with a weak probe beam. Absorption reduction dip due to electromagnetically induced transparency (EIT)effect induced by the cooling/trapping field in a V-type three-level system and a gain peak near the cycling transition are clearly observed. Several mechanisms mixed with EIT effect in a normal V-type three-level system are briefly discussed. A simple theoretical analysis based on a dressed-state model is presented for interpretation of the absorption spectra.

  14. Evaluation of a method for the determination of chromium in urine by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A method for the determination of chromium in urine by atomic absorption spectrometry, using electrothermic atomization with pyrolytic graphite tubes, is proposed. The determinations are performed by standard addition. The method is applicable to biologic monitoring of populations with different degrees of exposition. It is also used in the analysis of chromium in sediments. Results of chromium in urine of a population group non-exposed to the metal are presented. 11 refs

  15. Determination of vanadium in food and traditional Chinese medicine by graphite furnace atomic absorption spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Various experimental conditions were described for the vanadium determination by graphite furnace atomic ab-sorption spectroscopy (GFAAS). The experiments showed that when atomization took place under the conditions where thecombination of a pyrolytic coating graphite tube and fast raising temperature were used and the temperature was stable, thesignal peak shapes could be improved, the sensitivity was enhanced, and the memory effect was removed. The vanadium infood and traditional Chinese medicinal herbs can be accurately determined using the standard curve method.

  16. Recent developments in generation of volatile species and in their atomization for atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Dědina, Jiří; Arslan, Y.; Mester, Z.; Sturgeon, R. E.; Kratzer, Jan; Matoušek, Tomáš; Musil, Stanislav; Svoboda, Milan

    2014. s. 221-221. [Rio Symposium on Atomic Spectrometry /13./. 19.10.2014-24.10.2014, Merida, Yucatan] R&D Projects: GA AV ČR(CZ) M200311202; GA ČR GA14-23532S Institutional support: RVO:68081715 Keywords : Arsenic * speciation analysis * sapphire tube atomizer Subject RIV: CB - Analytical Chemistry, Separation

  17. Padronização interna em espectrometria de absorção atômica Internal standardization in atomic absorption spectrometry

    OpenAIRE

    Kelly G. Fernandes; Mercedes de Moraes; José A. Gomes Neto; Joaquim A. Nóbrega; Pedro V. Oliveira

    2003-01-01

    This paper describes a review on internal standardization in atomic absorption spectrometry with emphasis to the systematic and random errors in atomic absorption spectrometry and applications of internal standardization in flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry. The rules for selecting an element as internal standard, limitations of the method, and some comments about the application of internal standardization in atomic absorption spectrometry...

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

    International Nuclear Information System (INIS)

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

  19. Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

    International Nuclear Information System (INIS)

    An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271–453 nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24 μg L−1, and a relative standard deviation of 3%. - Highlights: • The use of an Acousto-Optic Tunable Filter (AOTF) as monochromator element in WC AAS is presented for the first time. • The system includes the possibility of using one or two parallel coils. • We propose a new atomization cell design, manufactured on PTFE with reduced size. • The temperature of the coils and the atomic clouds of Pb and Cr were observed synchronously with high temporal resolution

  20. Double tungsten coil atomic absorption spectrometer based on an acousto-optic tunable filter

    Energy Technology Data Exchange (ETDEWEB)

    Jora, M.Z. [Chemistry Institute, State University of Campinas, 13083-970, Campinas, SP (Brazil); Nóbrega, J.A. [Chemistry Department, Federal University of São Carlos, 13565-905, São Carlos, SP (Brazil); Rohwedder, J.J.R. [Chemistry Institute, State University of Campinas, 13083-970, Campinas, SP (Brazil); Pasquini, C., E-mail: manasses.jora@gmail.com [Chemistry Institute, State University of Campinas, 13083-970, Campinas, SP (Brazil)

    2015-01-01

    An atomic absorption spectrometer based on a quartz acousto-optic tunable filter (AOTF) monochromator operating in the 271–453 nm range, is described. The instrument was tailored to study the formation and evolution of electrothermal atomic cloud induced either by one or two tungsten coils. The spectrometer also includes a fast response programmable photomultiplier module for data acquisition, and a power supply capable of driving two parallel tungsten coils independently. The atomization cell herein described was manufactured in PTFE and presents a new design with reduced size. Synchronization between the instant of power delivering to start the atomization process and the detection was achieved, allowing for monitoring the atomization and thermal events synchronously and in real time. Absorption signals can be sampled at a rate of a few milliseconds, compatible with the fast phenomena that occur with electrothermal metallic atomizers. The instrument performance was preliminarily evaluated by monitoring the absorption of radiation of atomic clouds produced by standard solutions containing chromium or lead. Its quantitative performance was evaluated by using Cr aqueous solutions, resulting in detection limits as low as 0.24 μg L{sup −1}, and a relative standard deviation of 3%. - Highlights: • The use of an Acousto-Optic Tunable Filter (AOTF) as monochromator element in WC AAS is presented for the first time. • The system includes the possibility of using one or two parallel coils. • We propose a new atomization cell design, manufactured on PTFE with reduced size. • The temperature of the coils and the atomic clouds of Pb and Cr were observed synchronously with high temporal resolution.

  1. Experimental parameters of vanadium determination by atomic-absorption spectroscopy with graphite-furnace atomization

    International Nuclear Information System (INIS)

    It was found that impregnation of a graphite cuvette (HGA-72) with salts of elements which form stable carbides (Ta, Si, Nb, Zr, W, La) decreases the absorbance signal for vanadium. The slope of the atomization curves indicates that formation of vanadium atoms is inhibited, probably by formation of a ternary compound between the impregnating element, vanadium and graphite. On the contrary bigger signals and better repeatability of results may be achieved when the cuvette is coated with pyrolytic graphite and methane is added to the sheath gas. The presence of methane increases the atomization efficiency and compensates for the disadvantageous influence of any air present in the sheath gas. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

  3. Atomic-absorption programmes for the Hewlett Packard H.P. 97S programmable calculator

    International Nuclear Information System (INIS)

    This report outlines the limitations of the atomic-absorption (AA) programmes supplied with the Hewlett Packard H.P.97S programmable calculator, and proposes ways in which these limitations can be overcome. Three new programmes, for AA on-line analysis, off-line analysis and an automatic system, are described

  4. Atomic absorption spectrometer readout and data reduction using the LSI-11 microcomputer

    International Nuclear Information System (INIS)

    Some common instruments found in the chemistry laboratory have analog chart recorder output as their primary data readout media. Data reduction from this medium is slow and relatively inaccurate. This paper describes how to interface a single LSI-11 microcomputer to PERKIN-ELMER models 603 and 303 Atomic Absorption Spectrophotometers

  5. Determination of trace impurities in titanium dioxide by direct solid sampling electrothermal atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Vojtková, Blanka; Dočekal, Bohumil

    2005-01-01

    Roč. 99, S (2005), s489-s491. ISSN 0009-2770. [Meeting on Chemistry and Life /3./. Brno, 20.09.2005-22.09.2005] Institutional research plan: CEZ:AV0Z40310501 Keywords : solid sampling * electrothermal atomic absorption spectrometry * trace analysis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.445, year: 2005

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

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Atomic absorption spectrophotometer for clinical use. 862.2850 Section 862.2850 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... elements and metals (e.g., lead and mercury) in human specimens. The metal elements are...

  7. Direct microcomputer controlled determination of zinc in human serum by flow injection atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Simonsen, Kirsten Wiese; Nielsen, Bent; Jensen, Arne;

    1986-01-01

    A procedure is described for the direct determination of zinc in human serum by fully automated, microcomputer controlled flow injection atomic absorption spectrometry (Fl-AAS). The Fl system is pumpless, using the negative pressure created by the nebuliser. It only consists of a three-way valve...

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

    NARCIS (Netherlands)

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

    1979-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Аntonina Alemasova

    2012-11-01

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

  10. Structural studies using X-ray absorption and scattering techniques

    International Nuclear Information System (INIS)

    The thesis presents extended X-ray absorption fine structure, EXAFS, and large angle X-ray scattering, LAXS, techniques; instrumentation, data collection and reduction, and applications. These techniques have been used to determine the structures of magnesium halides and organomagnesium halides in diethyl ether and tetrahydrofuran solution. The iodides were used for the LAXS measurements and Br K edge EXAFS data were collected for the corresponding bromides. Two different complexes are present in the diethyl ether solution of magnesium iodide; a polymeric chain-type structure where magnesium is tetrahedrally coordinated, as well as dimeric complex with octahedrally coordinated magnesium. Solvated MgI+ is the dominating species in tetrahydrofuran solution. The organomagnesium halides are present in diethyl ether solution as both solvated monomeric and dimeric complexes. Magnesium coordinates a halide ion, an alkyl or aryl group and four solvent molecules octahedrally in the monomeric complex. In the dimeric complex magnesium is octahedrally coordinated by two bridging halide ions, an alkyl or aryl group and three solvent molecules. The distribution of monomeric and dimeric complexes in various solutions are given by a dimerisation constant, Kdl. The results indicate that the Schlenk equilibrium is present in these solutions, however, in an extended form. In diethyl ether solution, where MgX2 does not dissociate, no MgX2 complex and thereby no Schlenk equilibrium has been observed. In tetrahydrofuran solution MgI2 has dissociated into mainly MgI+ and I-. This indicates that the concentration of MgI2 is low and that the Schlenk equilibrium should be expanded even further to include the dissociation equilibrium of the magnesium halide. In the thesis Fe K edge EXAFS data collected for the semireduced form of protein A of methane monooxygenase from Methylococcus capsulatus, are also presented. (139 refs.)

  11. On-Line Preconcentration and Speciation of Chromium by an 8-Hydroxyquinoline Microcolumn Immobilized on Surfactant-Coated Alumina and Flow Injection Atomic Absorption Spectrometry

    OpenAIRE

    AHMADI, Seyyed Hamid; SHABANI, Ali Mohammad HAJI

    2007-01-01

    An on-line technique for the determination of chromium species with atomic absorption spectrometry is described. The method is based on separation and preconcentration of Cr(III) on a microcolumn of immobilized 8-hydroxyquinoline on surfactant-coated alumina. The adsorbed analyte is then eluted with 400 m L of 20% ethanolic solution of 1.5 mol L-1 hydrochloric acid and is transported to a flame atomic absorption spectrometer for quantification. The effects of pH, sample and eluent f...

  12. Nonlocal nonlinear response of thermal Rydberg atoms and modulational instability in absorptive nonlinear media

    CERN Document Server

    Zhang, Lida

    2015-01-01

    Nonlinear and nonlocal effects are discussed in the interaction of laser fields with thermal Rydberg atoms in electromagnetically induced transparency configuration. We show that under the crucial approximation that the time variation in the dipole-dipole interactions due to atomic motions can be neglected in an ensemble average, an analytical form can be obtained for the nonlocal nonlinear atomic response of the thermal medium, and study it for different parameter cases. We further propose a generalized model to describe the modulational instability (MI) in absorptive nonlinear media, in order to understand the propagation dynamics in the thermal Rydberg medium. Interestingly, this model predicts that at short propagation distances, each wave component exhibits the MI effect in absorptive nonlinear media, unlike in the purely dispersive case.

  13. Air quality status in Kinshasa as determined by instrumental neutron activation analysis, atomic absorption spectrometry and ion-exchange chromatography

    International Nuclear Information System (INIS)

    Three independent analytical techniques - instrumental neutron activation analysis. Atomic absorption spectrometry and ion-exchange chromatography - were applied to airborne particulate collected on filters and to atmospheric acid gases collected in carbonate buffer solutions. 20 trace elements and 7 acid gases and acid aerosols were determined. Results were compared with those observed elsewhere and showed that air pollution is low in Kinshasa and does not give rise to anxieties. The main known sources of pollutants are: vehicle exhaust and aeolian process on stripped soils. (author). 13 refs, 2 figs, 6 tabs

  14. X-ray absorption spectroscopy and atomic force microscopy study of bias-enhanced nucleation of diamond films

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.M.; Jimenez, I.; Vazquez, L.; Gomez-Aleixandre, C.; Albella, J.M.; Sanchez, O. [Instituto de Ciencia de Materiales, C.S.I.C., Cantoblanco28049, Madrid (Spain); Terminello, L.J. [Lawrence Livermore National Laboratory, Livermore, California94551 (United States); Himpsel, F.J. [Department of Physics, University of Wisconsin--Madison, Madison, Wisconsin53706 (United States)

    1998-04-01

    The bias-enhanced nucleation of diamond on Si(100) has been studied by x-ray absorption near-edge spectroscopy (XANES) and atomic force microscopy, two techniques well suited to characterize nanometric crystallites. Diamond nuclei of {approximately}15nm are formed after 5 min of bias-enhanced treatment. The number of nuclei and its size increases with the time of application of the bias voltage. A nanocrystalline diamond film is attained after 20 min of bias-enhanced nucleation. At the initial nucleation stages, the Si substrate appears covered with diamond crystallites and graphite, without SiC being detected by XANES. {copyright} {ital 1998 American Institute of Physics.}

  15. Atomic absorption spectrophotometry for the determination of metallic impurities in coal

    International Nuclear Information System (INIS)

    The Brazilian Energetic Alternative Program expects the reduction of our dependence on foreign energy sources, through replacing fuel oil by mineral coal. Its gasification by means of nuclear energy must be also considered. However, the intensive burning of coal leads to serious environmental problems. During its combustion the release, to atmosphere, of toxic elements such as As, Hg, Pb, Sb, Se, Cd, Zn and others is of great concern. Increase in atmospheric pollution will take place by burning increased amounts of coal. In addition, some of those elements are concentrated in fly ashes. The determination of impurities in coal is also important for the Figueiras Project in the Nuclebras Mineral Prospection Program. Hence, it is important to have reliable analytical methods which can monitor inorganic constituents at various stages of coal production and utilization. The atomic absorption spectrophotometry is a suitable analytical technique to determine pollutants in coal because it is sensitive, simple, economic and cover a large range of concentrations. The need of a previous treatment of the sample is overcome by using an acid attack (HNO3 + HClO4 + HF) which has proved to be rapid and efficient. (Author)

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

    International Nuclear Information System (INIS)

    A new software-controlled time-based multisyringe flow injection system for mercury determination by cold-vapor atomic absorption spectrometry is proposed. Precise known volumes of sample, reducing agent (1.1% SnCl2 in 3% HCl) and carrier (3% HCl) are dispensed into a gas-liquid separation cell with a multisyringe burette coupled with one three-way solenoid valve. An argon flow delivers the reduced mercury to the spectrometer. The optimization of the system was carried out testing reaction coils and gas-liquid separators of different design as well as changing parameters, such as sample and reagents volumes, reagent concentrations and carrier gas flow rate, among others. The analytical curves were obtained within the range 50-5000 ng L-1. The detection limit (3σ b/S) achieved is 5 ng L-1. The relative standard deviation (R.S.D.) was 1.4%, evaluated from 16 successive injections of 250 ng L-1 Hg standard solution. The injection and sample throughput per hour were 44 and 11, respectively. This technique was validated by means of solid and water reference materials with good agreement with the certified values and was successfully applied to fish samples

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

    Directory of Open Access Journals (Sweden)

    ROLANDAS KAZLAUSKAS

    2004-05-01

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

  18. Atomic absorption determination, in metal sulphide concentrates, of the elements that form gaseous hydrides

    International Nuclear Information System (INIS)

    An account is given of the investigational work on the determination of trace amounts of arsenic, antimony, bismuth, germanium, selenium, and tellurium by the technique using hydride generation and atomic-absorption spectrophotometry. The gaseous hydride is generated by reduction with sodium borohydride, and is subsequently swept by a flow of nitrogen into an air-entrained hydrogen-nitrogen flame. The generation equipment used is simple and inexpensive, and can be readily assembled in most laboratories. The optimum parameters were determined for each element. The effects of 31 probable interfering elements were investigated, and it was found that, although the majority did not interfere, severe interference was encountered when copper, nickel, and the noble metals were present. Methods for the elimination of copper and nickel were developed to allow the determination of arsenic, antimony, bismuth, selenium, and tellurium at the lower parts-per-million level in metal sulphide concentrates with an acceptable accuracy and precision. The determination of microgram amounts of germanium was found to be unsatisfactory

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

    Science.gov (United States)

    Duben, Ondřej; Boušek, Jaroslav; Dědina, Jiří; Kratzer, Jan

    2015-09-01

    Atomization of selenium hydride in a quartz dielectric barrier discharge (DBD) atomizer was optimized and its performance was compared to that of the externally heated quartz multiatomizer. Argon was found as the best DBD discharge gas employing a flow rate of 75 ml min- 1 Ar while the DBD power was optimized at 14 W. The detection limits reached 0.24 ng ml- 1 Se in the DBD and 0.15 ng ml- 1 Se in the multiatomizer. The tolerance of DBD to interferences is even better than with the multiatomizer.

  20. Analytical control of wollastonite for biomedical applications by use of atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry.

    Science.gov (United States)

    De Aza, P N; Guitián, F; De Aza, S; Valle, F J

    1998-04-01

    Preliminary in vitro experiments revealed that wollastonite (CaSiO3) is a potentially highly bioactive material that forms a hyroxyapatite (HA) surface layer on exposure to simulated body fluid with an ion concentration, pH and temperature virtually identical with those of human blood plasma. The formation of the HA layer is an essential requirement for an artificial material to be used as bioactive bone substitute. This finding opens up a wide field for biomedical applications of wollastonite. Biomaterials used as implants in the human body require strict control of trace elements and of the toxic species specified in American Society for Testing and Materials F-1185-88 (As, Cd, Hg and Pb) in ceramic hydroxyapatite for surgical implantation. In this work, two types of pseudowollastonite, the high temperature form of wollastonite, were analysed by using cold vapour atomic absorption spectrometry and hydride generation atomic absorption spectrometry, in order to determine the elements stated in the above-mentioned norm, and inductively coupled plasma atomic emission spectrometry to establish the SiO2/CaO ratio of the two materials and analyse for all other impurities introduced by the raw materials and by the processes of synthesis, sintering and grinding. Barium and Mg were especially prominent in raw materials, and Zr, Y, Mg, W, Co and Ni come mainly from the processing. PMID:9684401

  1. New diagnostic technique for Zeeman-compensated atomic beam slowing: technique and results

    OpenAIRE

    Molenaar, P.A.; Van Der Straten, P.; Heideman, H.G.M.; Metcalf, H.

    2001-01-01

    We have developed a new diagnostic tool for the study of Zeeman-compensated slowing of an alkali atomic beam. Our time-of-flight technique measures the longitudinal veloc- ity distribution of the slowed atoms with a resolution below the Doppler limit of 30 cm/s. Furthermore, it can map the position and velocity distribution of atoms in either ground hyperfine level inside the solenoid without any devices inside the solenoid. The technique reveals the optical pumping ef- fects, and shows in de...

  2. Three axis vector atomic magnetometer utilizing polarimetric technique

    CERN Document Server

    Pradhan, Swarupananda

    2016-01-01

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

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

    International Nuclear Information System (INIS)

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

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

    CERN Document Server

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

    2002-01-01

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

  5. Effective atomic numbers for photon energy absorption of some low-Z substances of dosimetric interest

    International Nuclear Information System (INIS)

    Effective atomic numbers for photon energy absorption (ZPEAeff) and effective atomic numbers for photon interaction (ZPIeff) of some low-Z substances of dosimetric interest such as A-150 tissue-equivalent plastic (A150TEP), alanine, bakelite, Gafchromic sensor (GS), plastic scintillator (PS), polyethylene, mylar, polystyrene, perspex, radiochromic dye film nylon base (RDF : NB), tissue-equivalent gas-methane based (TEG : MB) and tissue-equivalent gas-propane based (TEG : PB) have been calculated by a direct method in the energy region of 1 keV-20 MeV. Experimental mass attenuation coefficients and ZPIeff of some of these substances at selected photon energies of 26.34, 33.2, and 59.54 keV have been obtained and compared with theoretical values. The ZPEAeff and ZPIeff values steadily increases up to 6-15 keV, and then they steadily decrease up to 600-1500 keV for all the substances studied. From 1.5 MeV, the values increases with increase in energy up to 20 MeV. Significant differences up to 33.68% exist between ZPIeff and the ZPEAeff in the energy region of 10-150 keV. The single effective atomic numbers obtained using the program XMuDat (ZXMUDATeff ) are found to be significantly higher compared to those of ZPEAeff and ZPIeff values in the entire energy of interest for all the substances studied. The directly calculated ZPEAeff and ZPIeff values vary with energy compared to the energy-independent effective atomic numbers predicted by various theoretical expressions. The effects of absorption edges on effective atomic numbers and their variation with photon energy and the possibility of defining two set values of effective atomic numbers below the absorption edges of elements present in the composite substances are discussed

  6. Self-corrected sensors based on atomic absorption spectroscopy for atom flux measurements in molecular beam epitaxy

    International Nuclear Information System (INIS)

    A high sensitivity atom flux sensor based on atomic absorption spectroscopy has been designed and implemented to control electron beam evaporators and effusion cells in a molecular beam epitaxy system. Using a high-resolution spectrometer and a two-dimensional charge coupled device detector in a double-beam configuration, we employ either a non-resonant line or a resonant line with low cross section from the same hollow cathode lamp as the reference for nearly perfect background correction and baseline drift removal. This setup also significantly shortens the warm-up time needed compared to other sensor technologies and drastically reduces the noise coming from the surrounding environment. In addition, the high-resolution spectrometer allows the most sensitive resonant line to be isolated and used to provide excellent signal-to-noise ratio

  7. Three-photon-absorption resonance for all-optical atomic clocks

    International Nuclear Information System (INIS)

    We report an experimental study of an all-optical three-photon-absorption resonance (known as an 'N resonance') and discuss its potential application as an alternative to atomic clocks based on coherent population trapping. We present measurements of the N-resonance contrast, width and light shift for the D1 line of 87Rb with varying buffer gases, and find good agreement with an analytical model of this resonance. The results suggest that N resonances are promising for atomic clock applications

  8. Atomic calculations and search for variation of the fine-structure constant in quasar absorption spectra

    Science.gov (United States)

    Dzuba, V. A.; Flambaum, V. V.

    A brief review of the search for variation of the fine structure constant in quasar absorption spectra is presented. Special consideration is given to the role of atomic calculations in the analysis of the observed data. A range of methods which allow to perform calculations for atoms or ions with different electron structure and which cover practically all periodic table of elements is discussed. Critical compilation of the results of the calculations as well as a review of the most recent results of the analysis are presented.

  9. Atomic calculations and search for variation of the fine structure constant in quasar absorption spectra

    CERN Document Server

    Dzuba, V A

    2008-01-01

    A brief review of the search for variation of the fine structure constant in quasar absorption spectra is presented. Special consideration is given to the role of atomic calculations in the analysis of the observed data. A range of methods which allow to perform calculations for atoms or ions with different electron structure and which cover practically all periodic table of elements is discussed. Critical compilation of the results of the calculations as well as a review of the most recent results of the analysis are presented.

  10. Exploiting flow Injection and sequential injection schemes for trace metal determinations by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    Determination of low or trace-level amounts of metals by electrothermal atomic absorption spectrometry (ETAAS) often requires the use of suitable preconcentration and/or separation procedures in order to attain the necessary sensitivity and selectivity. Such schemes are advantageously executed in...... compensated by superior performance and versatility. In fact, two approaches are conceivable: The analyte-loaded ion-exchange beads might either be transported directly into the graphite tube where they are pyrolized and the measurand is atomized and quantified; or the loaded beads can be eluted and the...

  11. MERCURY QUANTIFICATION IN SOILS USING THERMAL DESORPTION AND ATOMIC ABSORPTION SPECTROMETRY: PROPOSAL FOR AN ALTERNATIVE METHOD OF ANALYSIS

    Directory of Open Access Journals (Sweden)

    Liliane Catone Soares

    2015-08-01

    Full Text Available Despite the considerable environmental importance of mercury (Hg, given its high toxicity and ability to contaminate large areas via atmospheric deposition, little is known about its activity in soils, especially tropical soils, in comparison with other heavy metals. This lack of information about Hg arises because analytical methods for determination of Hg are more laborious and expensive compared to methods for other heavy metals. The situation is even more precarious regarding speciation of Hg in soils since sequential extraction methods are also inefficient for this metal. The aim of this paper is to present a technique of thermal desorption associated with atomic absorption spectrometry, TDAAS, as an efficient tool for quantitative determination of Hg in soils. The method consists of the release of Hg by heating, followed by its quantification by atomic absorption spectrometry. It was developed by constructing calibration curves in different soil samples based on increasing volumes of standard Hg2+ solutions. Performance, accuracy, precision, and quantification and detection limit parameters were evaluated. No matrix interference was detected. Certified reference samples and comparison with a Direct Mercury Analyzer, DMA (another highly recognized technique, were used in validation of the method, which proved to be accurate and precise.

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

    Science.gov (United States)

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

    2014-01-01

    The total selenium (Se) was determined in herbal and pharmaceutical supplements used for liver diseases. The total Se contents were determined in different pharmaceutical and herbal supplements by hydride generation atomic absorption spectrometry (HGAAS) and graphite furnace atomic absorption spectrometry (GFAAS) after microwave-assisted acid digestion. The accuracy of the techniques was evaluated by using certified reference material and the standard addition method. The recoveries of total Se were 99.4 and 99.0% for HGAAS and GFAAS, respectively. The precision of the techniques expressed as RSD were 2.34 and 4.54% for HGAAS and GFAAS measurements, respectively. The LOD values for HGAAS and GFAAS were 0.025 and 0.052 pglg, respectively. The concentrations of Se in pharmaceutical and herbal supplements were found in the range of 19.2-53.8 and 25.0-42.5 pg/g, respectively, corresponding to 35-76% and 45-76% of the total recommended dose of Se for adults. PMID:25632445

  13. Evaluation of quartz tubes as atomization cells for gold determination by thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This work describes the development of a new analytical procedure able to determine gold by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) using nickel tubes (NiT) and quartz tubes (QT) as atomization cells. Experiments involving changes in the flow injection operational parameters, reagent concentrations and sizes of the QT were performed in order to optimize sensitivity. Under the same operational conditions, it was observed that the employment of QT increases the sensitivity of gold determination when compared to the nickel tube. Since solutions of highly concentrated hydrochloric acid showed the best performance as carriers, quartz tubes were also preferred due to its greater tolerance to corrosion by mineral acids in comparison to NiT. In addition, changes in the internal diameter of the QT revealed an important improvement in sensitivity for smaller tubes. Under optimized conditions the main figures of merit showed values close to that of graphite furnace atomic absorption spectrometry with the addition of an excellent improvement of the sample throughput. They are: LOD (3 s): 0.004 μg mL−1, sensitivity: 0.306 (μg mL−1)−1, RSD% (n = 10, 1 μg mL−1): 2.5, linear range: 0.01–4 μg mL−1 and sample throughput: 72 h−1. This new method was employed for the determination of gold in homeopathic medicines with no need of sample digestion. Validation of the analytical results will be shown. A full discussion of the most relevant findings regarding the role of the atomization cell as a strategic key for improving sensitivity will be also provided. - Highlights: ► Quartz tubes as furnaces in TS-FFAAS. ► Small tubes for controlling radial dispersion. ► Improved figures of merit for gold determination. ► Analysis of homeopathic medicines.

  14. Absorptive reduction and width narrowing in λ-type atoms confined between two dielectric walls

    International Nuclear Information System (INIS)

    This paper investigates the absorptive reduction and the width narrowing of electromagnetically induced transparency (EIT) in a thin vapour film of λ-type atoms confined between two dielectric walls whose thickness is comparable with the wavelength of the probe field. The absorptive lines of the weak probe field exhibit strong reductions and very narrow EIT dips, which mainly results from the velocity slow-down effects and transient behaviour of atoms in a confined system. It is also shown that the lines are modified by the strength of the coupling field and the ratio of L/λ, with L the film thickness and λ the wavelength of the probe field. A simple robust recipe for EIT in a thin medium is achievable in experiment. (general)

  15. Determination of iodine in seaweed and table salt by an indirect atomic absorption method

    International Nuclear Information System (INIS)

    Decomposition methods based on fusion with alkali are discussed, with respect to the determination of iodine in biological material. It is shown that sodium hydroxide can be used for the decomposition of seaweed without loss of iodine. In spite of the oxidizing conditions, the iodine will be present as iodide in the final ash. The iodide can be determined by an indirect atomic-absorption method, based on the reaction between iodide and mercury(II), with determination of mercury by cold vapour atomic-absorption spectrometry. The basis of the method is discussed, and it is shown that the use of tin(II) as reductant is essential. The effect of the oxidation state of the iodine on the sensitivity of the method is pointed out. High concentrations of chloride interfere, but it is still possible to determine iodide in iodinated table salt. (author)

  16. Determination of metallic impurities in raw materials for radioisotope production by atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Atomic absorption spectrometry has been used for the determination of traces of calcium in scandium oxide, copper in zinc, iron in cobalt oxide, manganese In ferric oxide, nickel in copper and zinc in gallium oxide. The influences on the sensitivities arising from the hollow cathode currents, the gas pressures and the acid concentrations have been considered. A study of the interferences from the metallic matrices has also been performed, the interference due to the absorption of the manganese radiation by the atoms of iron being the most outstanding . In order to remove the interfering elements and increase sensitivity, pre-concentration methods have been tested. The addition methods has also been used. (Author) 14 refs

  17. Atomic absorption determination of platinum and rhenium in deactivated catalysts based on γ-alumina

    International Nuclear Information System (INIS)

    A flame atomic absorption method has been developed for the determination of Pt and Re in deactivated catalysts based on γ-Al2O3. Hydrofluoric acid is used for catalyst dissolution. The lower determination limits are 1 μg/ml for Pt and 5 μg/ml for Re, RSD are 0.01-0.15 and 0.03-0.25 respectively

  18. Using a digital multimeter to capture spectral information generated by a spectrophotometer broadcast / atomic absorption

    International Nuclear Information System (INIS)

    Spectral analysis capability of the information generated by a spectrophotometer broadcast / shimadzu AA 640-13 atomic absorption has increased, through the capture of data, using a digital multimeter as the interface between the spectrophotometer and a computer. To facilitate the identification of analytes was created Chromulan format files for the 99 chemical elements reported in the literature, and covering the region between 200 nm and 900 nm, the subject of this study. (author)

  19. Atomic Absorption and Spectrophotometeric Determinations of Salicylhydroxamic Acid in Its Pure and Pharmaceutical Dosage Forms

    OpenAIRE

    SALEM, Alaa-Eldin AbdelAziz

    2003-01-01

    A new method for the indirect determination of salicylhydroxamic acid (SHAM) using atomic absorption spectrometry (AAS) was proposed. The method is based on precipitating the ion associate complex of SHAM with [Cu (NH3)4]2+. The excess, unreacted, Cu2+ ions were determined using AAS. Another spectrophotometric method based on measuring the absorbance of the formed [Cu (NH3)4]-SHAM complex in dioxane was proposed. The green color of the complex formed was measured at 330 nm. The two...

  20. Mineral Analysis the Infusion of Black Tea Samples by Atomic Absorption Spectrometry

    OpenAIRE

    Lahiji N.; Tadayon F.; Tamiji F.; Lahiji A. H.

    2013-01-01

    Tea infusion is one of the most popular drinks around the world. Since tea infusion is known to contain several essential nutrients, it is considered a healthy beverage. In this study eight different Iranian brands of tea infusion and eleven brands imported tea infusion samples from another country for Cu, Zn, Mn and Al were determined by flame atomic absorption spectrometry after wet digestion. The results of analysis showed that the extraction rates of minerals from dry black tea to infusio...

  1. High-frequency electrode less lamps for application in atomic absorption analysis

    International Nuclear Information System (INIS)

    Authors measured and optimised main characteristic of different EDL-s, interesting for their use in atomic absorption spectroscopy: working time, main spectral line intensities and spectral widths, as well as limits of detection for respective elements. In the experiment spectrometer MGA-915 was used. In the table the ultimate limits of detection (LOD) are compered for HF ED lamps and HJC lamps. LOD for HF EDL lamps are 1.5 - 8 times lower than ones for HCL-s

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Ladhaf, Bibifatima M.; Pawar, Pravina P.

    2015-04-01

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

  4. Nitride semiconductors studied by atom probe tomography and correlative techniques

    OpenAIRE

    Bennett, Samantha

    2011-01-01

    Optoelectronic devices fabricated from nitride semiconductors include blue and green light emitting diodes (LEDs) and laser diodes (LDs). To design efficient devices, the structure and composition of the constituent materials must be well-characterised. Traditional microscopy techniques used to examine nitride semiconductors include transmission electron microscopy (TEM), and atomic force microscopy (AFM). This thesis describes the study of nitride semiconductor materials using these tradi...

  5. Precision atomic physics techniques for nuclear physics with radioactive beams

    OpenAIRE

    Blaum, Klaus; Dilling, Jens; Nörtershäuser, Wilfried

    2013-01-01

    Atomic physics techniques for the determination of ground-state properties of radioactive isotopes are very sensitive and provide accurate masses, binding energies, Q-values, charge radii, spins, and electromagnetic moments. Many fields in nuclear physics benefit from these highly accurate numbers. They give insight into details of the nuclear structure for a better understanding of the underlying effective interactions, provide important input for studies of fundamental symmetries in physics...

  6. Diagnostic of dense plasmas by infrared schlieren and absorption techniques

    International Nuclear Information System (INIS)

    In dense arc plasmas (T approximately 12 500 K, Nsub(e) approximately 1-6 x 1017 cm -3) the high continuum emission, the strong broadening and self-absorption of the lines, as well as more fundamental problems of non-ideality (Nsub(D) 8/3πNsub(e)lambdasub(D)3 not >> 1) renders the usual diagnostics difficult. Infrared schlieren is shown to be a good alternative. Results are in good agreement for electron density with Stark broadening measurements using Griem's data. Absorption measurements also show that the plasma does not exhibit abnormal behaviour compared to the usual case (Nsub(D) >> 1). (author)

  7. Simultaneous multi-element atomic absorption system using photodiode array detector

    International Nuclear Information System (INIS)

    A photodiode array (PDA) detector-multichannel analyser (MCA) system has been coupled to a flame and a graphite furnace atomiser and tested for simultaneous multielement atomic absorption analysis. Multielement hollow cathode lamps (HCL) are used as light source. Spectral lines are dispersed through a spectrograph with triple gratings and detected by a 25.4 mm PDA detector consisting of 1024 elements. The optical MCA system is capable of recording multiple spectra spanned by the spectrograph/PDA. The transmitted intensity spectra obtained for the standard and analyte solutions during flame or graphite furnace atomisation are converted to absorbance spectra using the MCA software provided. Results from the comparison studies show that the linear range and sensitivities for Ni-Co-Fe and Cu-Cr obtained from the simultaneous measurements are within the same order of magnitudes as those from conventional single element determinations using photomultiplier tube detection. The study also shows that non-atomic absorption can be readily corrected by a two-line method where non-atomic absorption lines can be chosen from the spectra recorded simultaneously. The proposed system has been evaluated for the determination of trace elements using NBS standard reference water SRM 1643b

  8. Atomic-absorption determination of tantalum and niobium in ore concentrates

    International Nuclear Information System (INIS)

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

  9. A comparison of simultaneous plasma, atomic absorption, and iron colorimetric determinations of major and trace constituents in acid mine waters

    Science.gov (United States)

    Ball, J.W.; Nordstrom, D.K.

    1994-01-01

    Sixty-three water samples collected during June to October 1982 from the Leviathan/Bryant Creek drainage basin were originally analyzed by simultaneous multielement direct-current plasma (DCP) atomic-emission spectrometry, flame atomic-absorption spectrometry, graphite-furnace atomic-absorption spectrometry (GFAAS) (thallium only), ultraviolet-visible spectrometry, and hydride-generation atomic-absorption spectrometry.Determinations were made for the following metallic and semi-metallic constituents: AI, As, B, Ba, Be, Bi, Cd, Ca, Cr, Co, Cu, Fe(11), Fe(total), Li, Pb, Mg, Mn, Mo, Ni, K, Sb, Se, Si, Na, Sr, TI, V, and Zn. These samples were re-analyzed later by simultaneous multielement inductively coupled plasma (ICP) atomic-emission spectrometry and Zeeman-corrected GFAAS to determine the concentrations of many of the same constituents with improved accuracy, precision, and sensitivity. The result of this analysis has been the generation of comparative concentration values for a significant subset of the solute constituents. Many of the more recently determined values replace less-than-detection values for the trace metals; others constitute duplicate analyses for the major constituents. The multiple determinations have yielded a more complete, accurate, and precise set of analytical data. They also have resulted in an opportunity to compare the performance of the plasma-emission instruments operated in their respective simultaneous multielement modes. Flame atomic-absorption spectrometry was judged best for Na and K and hydride-generation atomic-absorption spectrometry was judged best for As because of their lower detection limit and relative freedom from interelement spectral effects. Colorimetric determination using ferrozine as the color agent was judged most accurate, precise, and sensitive for Fe. Cadmium, lead, and vanadium concentrations were too low in this set of samples to enable a determination of whether ICP or DCP is a more suitable technique. Of

  10. Zero absorption and a large negative refractive index in a left-handed four-level atomic medium

    International Nuclear Information System (INIS)

    In this paper, we have investigated three external fields interacting with the four-level atomic system described by the density-matrix approach. The atomic system exhibits left-handedness with zero absorption and large negative refractive index. Varying the parameters of the three external fields, the properties of zero absorption and large negative refractive index from the atomic system remain unvarying. Our scheme proposes an approach to obtain a negative refractive medium with zero absorption. The zero absorption property of the atomic system may be used to amplify the evanescent waves that have been lost in the imaging by traditional lenses, and a slab fabricated by the left-handed atomic system may be an ideal candidate for designing perfect lenses.

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

    International Nuclear Information System (INIS)

    A direct sampling graphite furnace atomic absorption spectrometric (DS-GFAAS) method for the determination of Cd, Pb, Cr, Ni, Co and Cu in paints has been developed. Serigraphy, acrylic and tattoo paints were analysed. Approaches like pyrolysis and atomization temperatures, modifiers and sample mass introduced in the atomizer were studied. Quantification was performed using calibration curves measured with aqueous standard solutions pipetted onto the platform. The sample mass introduced in the graphite tube ranged from 0.02 to 8.0 mg. Palladium was used as modifier for Cd, Pb and Cu, while Mg(NO3)2 was used for Co. For Ni determination, the graphite platform was covered with carbon powder. The characteristic masses of Cd, Pb, Cr, Ni, Co and Cu were 1.4, 22.5, 7.9, 11.0, 9.6 and 12.5 pg, while the limits of detection were 0.0004, 0.001, 0.03, 0.22, 0.11 and 0.05 μg g-1 of Cd, Pb, Cr, Ni, Co and Cu, respectively. The accuracy was determined by comparison of the results with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) and graphite furnace atomic absorption spectrometry (GFAAS), using liquid sampling of digests. For matrix characterization, major and minor elements (Al, Mg, Ba, Ca, Cr, Cu, Pb, Sr, Ti and Mg) were determined by inductively coupled plasma optical emission spectrometry (ICP OES)

  12. Laser-excitation technique for the measurement of absolute transition probabilities of weak atomic lines

    Science.gov (United States)

    Kwong, H. S.; Smith, P. L.; Parkinson, W. H.

    1982-01-01

    A new technique is presented for the measurement of transition probabilities for weak allowed, intersystem, and forbidden lines. The method exploits the fact that oscillator strength is proportional to the number of stimulated absorptions and emissions produced by a narrow-band laser pulse of known energy which is in resonance with an atomic transition. The method is tested for a particular transition of Mg I with a known oscillator strength value and of appropriate magnitude. The number densities are measured using a Mach-Zehnder interferometer and the hook method for the lower level population and by measuring an absorption-equivalent width for the other. The apparatus consisted of a high-power tunable laser and a magnesium oven to produce excited Mg vapor, and a laser-plasma background continuum. The results are in good agreement with theoretical and other experimental data.

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

    Directory of Open Access Journals (Sweden)

    JELENA J. SAVOVIC

    2001-08-01

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

  14. Manipulating absorption and diffusion of H atom on graphene by mechanical strain

    Directory of Open Access Journals (Sweden)

    Ming Yang

    2011-09-01

    Full Text Available Effects of the tensile strain on absorption and diffusion of hydrogen atoms on graphene have been studied by first-principles calculations. Our calculations suggested that there exists a barrier of 0.22 eV for H atom to diffuse from free space to graphene. The barrier originates from the transition of the hybridization of the H-binded carbon atom in graphene from sp2 to sp3, and is robust against the tensile strain. It was also found that, first, the in-plane diffusion of H atoms on graphene is unlikely to happen at low temperature due to the high barrier without or with strain, and second, the tensile strain along the armchair direction greatly decreases the out-plane diffusion barrier of H atoms, making it possible at low temperature. In particular, when the armchair strain is moderate (<10%, we found that the out-plane diffusion of H atoms likely to happen by diffusing through C-C bonds, and for relatively large armchair strain around 15%, the out-plane diffusion will happen though the center of the benzene ring.

  15. Slurry sampling procedure for the determination of lead in human hair by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. Human hair is a stable matrix that presents numerous advantages for human biomonitoring, such as easy collection, low cost, easy transport and storage, information about short- and long-term exposure (Angerer J et al., Int. J. Hyg. Environ. Health, 2007, 201-228). The use of the slurry sampling procedure was applied for the determination of lead in human hair by electrothermal atomic absorption spectrometry (ETAAS). This technique presents high sensitivity, low cost and the possibility of direct determination. Hair samples were pulverized using a cryogenic mill. Ten milligrams of the hair powder were transferred into a polyethylene vial and 2 ml of 2.5% HNO3 and 1.5% H2O2 were added. The slurries were maintained homogeneous with air bubbling with an aquarium pump. Niobium and Rhodium were chosen from several potential permanent modifiers by evaluating the background and absorbance signals obtained under the conditions recommended by the manufacturer. A 23 factorial design and a central composite design (CCD) were realized to optimize permanent modifier and pyrolysis and atomization temperatures. The parameters of merit were obtained in the optimized conditions (Tp = 660 deg C, Ta = 1780 deg C and Rh), and they were as follows: linear working range up to 50 μg L-1; limit of detection (0.032 0.002) μg g-1; limit of quantification (0.106 0.005) μg g-1; matrix-matched calibration, with r2 > 0.99 and reproducibility ranged from 2.3 to 4.2 relative standard deviation (RSD). The accuracy was evaluated by recovery tests and comparing slurry sampling and microwave decomposition. The recovery values for different concentrations were in the range between 89 and 101% and non-significant differences were observed (t-test; p = 0.05) when comparing the average of lead values obtained from microwave decomposition method and proposed method. Lead concentrations in different samples ranged between 0.13 and 1.11 μg g-1. The authors kindly

  16. ALCHEMI: a new technique for locating atoms in small crystals

    International Nuclear Information System (INIS)

    Atom Location by Channelling Enhanced Microanalysis (ALCHEMI) is a quantitative technique for identifying the crystallographic sites, distribution and types of substitutional impurities in many crystals. The method involves no adjustable parameters, can be applied to areas as small as a few hundred Angstroms and to impurity concentrations down to about 0.1 atomic per cent. It is capable of distinguishing neighbours in the periodic table. The method uses the incident electron beam orientation dependence of characteristic X-ray emission and uses an energy dispersive X-ray microanalyser fitted to a transmission electron microscope. The method does not require the specimen thickness or precise orientation to be known, and makes few assumptions about the form of the dynamical electron wavefunction, which need not be calculated or predicted. The classical problems of cation ordering in spinels, feldspars and olivine have now been studied by this method. (author)

  17. 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

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

    Science.gov (United States)

    Demirtaş, İlknur; Bakırdere, Sezgin; Ataman, O Yavuz

    2015-06-01

    Flame atomic absorption spectrometry (FAAS) still keeps its importance despite the relatively low sensitivity; because it is a simple and economical technique for determination of metals. In recent years, atom traps have been developed to increase the sensitivity of FAAS. Although the detection limit of FAAS is only at the level of µg/mL, with the use of atom traps it can reach to ng/mL. Slotted quartz tube (SQT) is one of the atom traps used to improve sensitivity. In atom trapping mode of SQT, analyte is trapped on-line in SQT for few minutes using ordinary sample aspiration, followed by the introduction of a small volume of organic solvent to effect the revolatilization and atomization of analyte species resulting in a transient signal. This system is economical, commercially available and easy to use. In this study, a sensitive analytical method was developed for the determination of lead with the help of SQT atom trapping flame atomization (SQT-AT-FAAS). 574 Fold sensitivity enhancement was obtained at a sample suction rate of 3.9 mL/min for 5.0 min trapping period with respect to FAAS. Organic solvent was selected as 40 µL of methyl isobutyl ketone (MIBK). To obtain a further sensitivity enhancement inner surface of SQT was coated with several transition metals. The best sensitivity enhancement, 1650 fold enhancement, was obtained by the Ta-coated SQT-AT-FAAS. In addition, chemical nature of Pb species trapped on quartz and Ta surface, and the chemical nature of Ta on quartz surface were investigated by X-ray photoelectron spectroscopy (XPS) and Raman Spectroscopy. Raman spectrometric results indicate that tantalum is coated on SQT surface in the form of Ta2O5. XPS studies revealed that the oxidation state of Pb in species trapped on both bare and Ta coated SQT surfaces is +2. For the accuracy check, the analyses of standard reference material were performed by use of SCP SCIENCE EnviroMAT Low (EU-L-2) and results for Pb were to be in good agreement with

  19. Handbook of theoretical atomic physics. Data for photon absorption, electron scattering, and vacancies decay

    International Nuclear Information System (INIS)

    The aim of this book is to present highly accurate and extensive theoretical Atomic data and to give a survey of selected calculational methods for atomic physics, used to obtain these data. The book presents the results of calculations of cross sections and probabilities of a broad variety of atomic processes with participation of photons and electrons, namely on photoabsorption, electron scattering and accompanying effects. Included are data for photoabsorption and electron scattering cross-sections and probabilities of vacancy decay formed for a large number of atoms and ions. Attention is also given to photoionization and vacancy decay in endohedrals and to positron-atom scattering. The book is richly illustrated. The methods used are one-electron Hartree-Fock and the technique of Feynman diagrams that permits to include many-electron correlations. This is done in the frames of the Random Phase approximation with exchange and the many-body perturbation theory. Newly obtained and previously collected atomic data are presented. The atomic data are useful for investigating the electronic structure and physical processes in solids and liquids, molecules and clusters, astronomical objects, solar and planet atmospheres and atomic nucleus. Deep understanding of chemical reactions and processes is reached by deep and accurate knowledge of atomic structure and processes with participation of atoms. This book is useful for theorists performing research in different domains of contemporary physics, chemistry and biology, technologists working on production of new materials and for experimentalists performing research in the field of photon and electron interaction with atoms, molecules, solid bodies and liquids.

  20. Handbook of theoretical atomic physics. Data for photon absorption, electron scattering, and vacancies decay

    Energy Technology Data Exchange (ETDEWEB)

    Amusia, Miron [Hebrew Univ., Jerusalem (Israel). Racah Inst. of Physics; Ioffe Physico-Technical Inst., St. Petersburg (Russian Federation); Chernysheva, Larissa [Ioffe Physico-Technical Inst., St. Petersburg (Russian Federation); Yarzhemsky, Victor [Kurnakov Institute of General and Inorganic Chemistry, Moscow (Russian Federation)

    2012-07-01

    The aim of this book is to present highly accurate and extensive theoretical Atomic data and to give a survey of selected calculational methods for atomic physics, used to obtain these data. The book presents the results of calculations of cross sections and probabilities of a broad variety of atomic processes with participation of photons and electrons, namely on photoabsorption, electron scattering and accompanying effects. Included are data for photoabsorption and electron scattering cross-sections and probabilities of vacancy decay formed for a large number of atoms and ions. Attention is also given to photoionization and vacancy decay in endohedrals and to positron-atom scattering. The book is richly illustrated. The methods used are one-electron Hartree-Fock and the technique of Feynman diagrams that permits to include many-electron correlations. This is done in the frames of the Random Phase approximation with exchange and the many-body perturbation theory. Newly obtained and previously collected atomic data are presented. The atomic data are useful for investigating the electronic structure and physical processes in solids and liquids, molecules and clusters, astronomical objects, solar and planet atmospheres and atomic nucleus. Deep understanding of chemical reactions and processes is reached by deep and accurate knowledge of atomic structure and processes with participation of atoms. This book is useful for theorists performing research in different domains of contemporary physics, chemistry and biology, technologists working on production of new materials and for experimentalists performing research in the field of photon and electron interaction with atoms, molecules, solid bodies and liquids.

  1. Determination of trace and minor elements in alloys by atomic-absorption spectroscopy using an induction-heated graphite-well furnace as atom source-II.

    Science.gov (United States)

    Ashy, M A; Headridge, J B; Sowerbutts, A

    1974-06-01

    Results are presented for the atomic-absorption spectrophotometric determination of zinc in aluminium and aluminium-silicon alloys, and aluminium, antimony and tin in steels, by means of solid samples dropped into an induction-heated graphite-well furnace to produce the atomic vapour. PMID:18961510

  2. Study on Differential Optical Absorption Spectroscopy : Technique and its Applications

    OpenAIRE

    Liu, Jianguo

    2002-01-01

    ln the first part of speech, with a description of the principle of DOAS (Differential Optical Absorption Spectroscopy), the design and realization of two different kinds of DOAS systems are nresented. 0ne is using a slotted disc raoid scanning device with a photomultiplier, which is suitable for ambient air quality measurement. It can measure total 16 kinds of pollutants such as SO_2, NO, N02, NH_3, O_3, C_6H_6, C_7H_8 and CH_2O etc., with detection limits of 1-2ppb. The other is using a UV ...

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

    Science.gov (United States)

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

  4. Operating Point Estimation for an Absorption Process using Data Clustering Technique

    OpenAIRE

    Hamdan Mokhtar; Shaharin A. Sulaiman; M. Amin A. Majid; A.L. Tamiru

    2013-01-01

    As part of a tri-generation plant, an absorption process provides the means to recover the energy that otherwise would be lost to the environment. Since the overall efficiency relies on the amount of energy recovered in all subsystems, knowing the current performance of the absorption process is vital to proper management of the resources. This study proposes the use of data clustering technique to estimate the most frequent operating point experienced by the absorption system in a give...

  5. Spectro web: oscillator strength measurements of atomic absorption lines in the sun and procyon

    International Nuclear Information System (INIS)

    We update the online SpectroWeb database of spectral standard reference stars with 1178 oscillator strength values of atomic absorption lines observed in the optical spectrum of the Sun and Procyon (α CMi A). The updated line oscillator strengths are measured with best fits to the disk-integrated KPNO-FTS spectrum of the Sun observed between 4000 A and 6800 A using state-of-the-art detailed spectral synthesis calculations. A subset of 660 line oscillator strengths is validated with synthetic spectrum calculations of Procyon observed with ESO-UVES between 4700 A and 6800 A. The new log(gf)-values in SpectroWeb are improvements upon the values offered in the online Vienna Atomic Line Database (VALD). We find for neutral iron-group elements, such as Fe I, Ni I, Cr I, and Ti I, a statistically significant over-estimation of the VALD log((gf)-values for weak absorption lines with normalized central line depths below 15 %. For abundant lighter elements (e.g. Mg I and Ca I) this trend is statistically not significantly detectable, with the exception of Si I for which the log(gf)-values of 60 weak and medium-strong lines are substantially decreased to best fit the observed spectra. The newly measured log(gf)-values are available in the SpectroWeb database at http://spectra.freeshell.org, which interactively displays the observed and computed stellar spectra, together with corresponding atomic line data.

  6. Nonlinear control techniques for an atomic force microscope system

    Institute of Scientific and Technical Information of China (English)

    Yongchun FANG; Matthew FEEMSTER; Darren DAWSON; Nader M.JALILI

    2005-01-01

    Two nonlinear control techniques are proposed for an atomic force microscope system.Initially,a learning-based control algorithm is developed for the microcantilever-sample system that achieves asymptotic cantilever tip tracking for periodic trajectories.Specifically,the control approach utilizes a learning-based feedforward term to compensate for periodic dynamics and high-gain terms to account for non-periodic dynamics.An adaptive control algorithm is then developed to achieve asymptotic cantilever tip tracking for bounded tip trajectories despite uncertainty throughout the system parameters.Simulation results are provided to illustrate the efficacy and performance of the control strategies.

  7. Radioisotope techniques for the study of protein absorption

    International Nuclear Information System (INIS)

    The earliest attempt to use a labelled protein for the study of intestinal absorption was made in 1952. Researchers were able to show that an oral dose of I131-labelled casein was not absorbed as satisfactorily by patients with fibrocystic disease of the pancreas as by normal subjects. Their method basically consisted of feeding I131-labelled casein with a load of inactive protein and measuring the amount of unabsorbed radioactivity appearing in the faeces. This method was also used in patients with other pancreatic disorders in whom protein malabsorption was also demonstrated. However, this method did not show any malabsorption of protein in patients with coeliac disease, who are known to have a high faecal nitrogen similar to that found in pancreatic disease. One possible cause of this discrepancy could be deiodination of the labelled protein in the lumen of the bowel. To overcome this difficulty, H3-labelled albumin has recently been used to measure absorption in patients with intestinal disease. 2 figs, 1 tab

  8. Possible atomic structures responsible for the sub-bandgap absorption of chalcogen-hyperdoped silicon

    International Nuclear Information System (INIS)

    Single-crystal silicon was hyperdoped with sulfur, selenium, and tellurium using ion implantation and nanosecond laser melting. The hyperdoping of such chalcogen elements led to strong and wide sub-bandgap light absorption. Annealing the hyperdoped silicon, even at low temperatures (such as 200–400 °C), led to attenuation of the sub-bandgap absorption. To explain the attenuation process, we modeled it as chemical decomposition reaction from an optically absorbing structure to a non-absorbing structure. Attenuation of the experimental absorption coefficient was fit using the Arrhenius equation. From the fitted data, we extracted the reaction activation energies of S-, Se-, and T-hyperdoped silicon as 0.338 ± 0.029 eV, 0.471 ± 0.040 eV, and 0.357 ± 0.028 eV, respectively. We discuss these activation energies in terms of the bond energies of chalcogen–Si metastable bonds, and suggest that several high-energy interstitial sites, rather than substitutional sites, are candidates for the atomic structures that are responsible for the strong sub-bandgap absorption of chalcogen hyperdoped silicon

  9. Possible atomic structures responsible for the sub-bandgap absorption of chalcogen-hyperdoped silicon

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ke-Fan [Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Shao, Hezhu [Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201 (China); Liu, Kong; Qu, Shengchun, E-mail: qsc@semi.ac.cn, E-mail: wangyx@henu.edu.cn; Wang, Zhanguo [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Wang, Yuanxu, E-mail: qsc@semi.ac.cn, E-mail: wangyx@henu.edu.cn [Institute for Computational Materials Science, School of Physics and Electronics, Henan University, Kaifeng 475004 (China)

    2015-09-14

    Single-crystal silicon was hyperdoped with sulfur, selenium, and tellurium using ion implantation and nanosecond laser melting. The hyperdoping of such chalcogen elements led to strong and wide sub-bandgap light absorption. Annealing the hyperdoped silicon, even at low temperatures (such as 200–400 °C), led to attenuation of the sub-bandgap absorption. To explain the attenuation process, we modeled it as chemical decomposition reaction from an optically absorbing structure to a non-absorbing structure. Attenuation of the experimental absorption coefficient was fit using the Arrhenius equation. From the fitted data, we extracted the reaction activation energies of S-, Se-, and T-hyperdoped silicon as 0.338 ± 0.029 eV, 0.471 ± 0.040 eV, and 0.357 ± 0.028 eV, respectively. We discuss these activation energies in terms of the bond energies of chalcogen–Si metastable bonds, and suggest that several high-energy interstitial sites, rather than substitutional sites, are candidates for the atomic structures that are responsible for the strong sub-bandgap absorption of chalcogen hyperdoped silicon.

  10. Coherent population trapping on 87Rb atoms in small-size absorption cells with buffer gas

    Science.gov (United States)

    Ermak, S. V.; Petrenko, M. V.; Semenov, V. V.

    2016-02-01

    Coherent population trapping (CPT) on 87Rb atoms in neon atmosphere has been studied in small-size glass absorption cells under conditions of pumping with narrow-band laser radiation at the D2 line of the main doublet. Parameters of the absorption signal have been measured in 3-mm-diameter cells at buffer gas (Ne) pressures varied within 200-400 Torr, cell temperatures within 65-120°C, and pumping radiation power densities within 30-400 μW/cm2. Optimum values of the buffer gas pressures, cell temperature, and pumping power are determined at which the short-term instability of the resonance line is at minimum. Orientational shifts of the CPT resonance signal in gas-filled cells and small-size cells with antirelaxation coating have been compared.

  11. Direct and absolute absorption measurements in optical materials and coatings by laser induced deflection (LID) technique

    Science.gov (United States)

    Mühlig, Ch.

    2012-01-01

    Different strategies of the laser induced deflection (LID) technique for direct and absolute absorption measurements are presented. Besides selected strategies for bulk and coating absorption measurements, respectively, a new strategy is introduced allowing the transfer of the LID technique to very small samples and to significantly increase the sensitivity for materials with a very weak photo-thermal response. Additionally, an emphasis is placed on the importance of the calibration procedure. The electrical calibration of the LID setup is compared to two other approaches that use either doped samples or highly absorptive reference samples in combination with numerical simulations. Applying the LID technique, we report on the characterization of AR coated LBO crystals used in high power NIR/VIS laser applications. The comparison of different LBO crystals shows that there are significant differences in both, the AR coating and the LBO bulk absorption. These differences are much larger at 515 nm than at 1030 nm. Absorption spectroscopy measurements combining LID technique with a high power OPO laser system indicate that the coating process affects the LBO bulk absorption properties. Furthermore, the change of the absorption upon 1030 nm laser irradiation of a Nd:YVO4 laser crystal is investigated and compared to recent results. Finally, Ytterbium doped silica raw materials for high power fiber lasers are characterized with respect to the absorption induced attenuation at 1550 nm in order to compare these data with the total attenuation obtained for the subsequently manufactured laser active fibers.

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

    Energy Technology Data Exchange (ETDEWEB)

    Karadjova, Irina B.; Petrov, Panayot K. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria); Serafimovski, Ivan [Food Institute, Faculty of Veterinary Medicine, Sts. Cyril and Methodius University, P.O. Box 95, MK-1000, Skopje (Macedonia, The Former Yugoslav Republic of); Stafilov, Trajce [Institute of Chemistry, Faculty of Science, Sts. Cyril and Methodius University, P.O. Box 162, MK-1000, Skopje (Macedonia, The Former Yugoslav Republic of); Tsalev, Dimiter L. [Faculty of Chemistry, University of Sofia, 1 James Bourchier Blvd., Sofia 1164 (Bulgaria)], E-mail: tsalev@chem.uni-sofia.bg

    2007-03-15

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

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

    International Nuclear Information System (INIS)

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

  14. Electron--photon coincidence technique for electron impact on atoms

    International Nuclear Information System (INIS)

    A brief introduction is given to the general theory of the electron photon coincidence technique, and the specific application to 1P and 3P excitations in helium is described. The relation between the complex excitation amplitudes which characterize the collision process and the alignment and orientation of the excited atoms is emphasized. The data from the first electron photon angular correlation measurements are presented. These data yield values for the ratio of differential cross sections for exciting the degenerate sublevels and the relative phase of the corresponding amplitudes, or, equivalently, the alignment and orientation parameters. The results are obtained in dimensionless form and are free from absolute calibration or normalization difficulties. They are compared with various theoretical approximations. The application of the coincidence technique to a measurement of threshold polarization is described and results for 31P excitations are discussed

  15. Absorption spectroscopy characterization measurements of a laser-produced Na atomic beam

    Energy Technology Data Exchange (ETDEWEB)

    Ching, C.H.; Bailey, J.E.; Lake, P.W.; Filuk, A.B.; Adams, R.G.; McKenney, J.

    1996-06-01

    This work describes a pulsed Na atomic beam source developed for spectroscopic diagnosis of a high-power ion diode on the Particle Beam Fusion Accelerator II. The goal is to produce a {approximately} 10{sup 12}-cm{sup {minus}3}-density Na atomic beam that can be injected into the diode acceleration gap to measure electric and magnetic fields from the Stark and Zeeman effects through laser-induced-fluorescence or absorption spectroscopy. A {approximately} 10 ns fwhm, 1.06 {micro}m, 0.6 J/cm{sup 2} laser incident through a glass slide heats a Na-bearing thin film, creating a plasma that generates a sodium vapor plume. A {approximately} 1 {micro}sec fwhm dye laser beam tuned to 5,890 {angstrom} is used for absorption measurement of the Na I resonant doublet by viewing parallel to the film surface. The dye laser light is coupled through a fiber to a spectrograph with a time-integrated CCD camera. A two-dimensional mapping of the Na vapor density is obtained through absorption measurements at different spatial locations. Time-of-flight and Doppler broadening of the absorption with {approximately} 0.1 {angstrom} spectral resolution indicate that the Na neutral vapor temperature is about 0.5 to 2 eV. Laser-induced-fluorescence from {approximately} 1 {times} 10{sup 12}-cm{sup {minus}3} Na I 3s-3p lines observed with a streaked spectrograph provides a signal level sufficient for {approximately} 0.06 {angstrom} wavelength shift measurements in a mock-up of an ion diode experiment.

  16. Arsenic and antimony determination in refined and unrefined table salts by means of hydride generation atomic absorption spectrometry--comparison of sample decomposition and determination methods

    OpenAIRE

    AKSUNER, Nur; TİRTOM, Vedia Nüket; HENDEN, Emür

    2011-01-01

    An evaluation was made of different digestion methods for the determination of arsenic and antimony in table salt samples prior to hydride generation atomic absorption spectrometric analysis. Microwave acid digestion, classical wet digestion, dry ashing, and fusion were applied to the decomposition of salt samples and optimum conditions were investigated. Samples were decomposed by changing heating time, digestion techniques, and the amount and composition of acid, and then the concen...

  17. Telecom-heralded single-photon absorption by a single atom

    Science.gov (United States)

    Lenhard, Andreas; Bock, Matthias; Becher, Christoph; Kucera, Stephan; Brito, José; Eich, Pascal; Müller, Philipp; Eschner, Jürgen

    2015-12-01

    We present, characterize, and apply the architecture of a photonic quantum interface between the near infrared and telecom spectral regions. A singly resonant optical parametric oscillator (OPO) operated below threshold, in combination with external filters, generates high-rate (>2.5 ×106s-1 ) narrowband photon pairs (˜7 MHz bandwidth); the signal photons are tuned to resonance with an atomic transition in Ca+, while the idler photons are at telecom wavelength. Interface operation is demonstrated through high-rate absorption of single photons by a single trapped ion (˜670 s-1 ), heralded by coincident telecom photons.

  18. Determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    The determination of Ca, Cu, Fe and Pb in sugarcane raw spirits by atomic absorption spectrophotometry was carried out. For 20 μL injected sample, calibration within the 0,5-25,0 mg. L-1 Ca; 0,25-5,0 mg. L-1 Cu, Pb and Cu intervals were established using the ratios Cu, Ca, Fe and Pb absorbance versus analyte concentration, respectively. Typical linear correlations of r = 0,999 were obtained. The proposed method was applied for the direct determination of Ca, Cu, Fe and Pb in sugar cane spirits, and in samples. The results obtained were in accordance to those obtained at 95% confidence level

  19. Determination of Na and Fe in high level liquid waste by closure atom absorption spectrum

    International Nuclear Information System (INIS)

    A method of measuring Na and Fe in High Level Liquid Waste (HLLW) by gloved fire atom absorption spectrometry was established. High Level Liquid Waste (HLLW) could be directly measured. The stabilization of the method is good. The operation is convenience and fast. The precision (RSD) of Na and Fe is better than 2% and 4% respectively. The precision (RSD) of Na and Fe is better than 2% and 4% respectively. The standard added-recovery for Na and Fe is 98.7% and 96.8% respectively. The results are well agreed with that obtained by other method and passed through F test. (authors)

  20. The determination, by atomic-absorption spectrophotometry, of trace elements in sulphide concentrates

    International Nuclear Information System (INIS)

    The separation, concentration, and determination of trace elements in base-metal and sulphide concentrates are described. After the sample has been dissolved, the trace elements that form insoluble hydroxides are precipitated with lanthanum as the coprecipitant and are separated from those elements that form soluble amines with ammonia. The precipitate is dissolved, and the trace elements selenium, tellurium, arsenic, antimony, bismuth, tin, vanadium, chromium, manganese, and aluminium are determined by atomic-absorption spectrophotometry. Coefficients of variation between 1 and 10 per cent, depending on the amount of the element, were obtained, with limits of determination ranging from 0,1 to 50 p.p.m

  1. Direct determination of sodium and potassium in blood serum by flow injection and atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    A simple and reliable method for the measurement of sodium and potassium in blood serum without any sample dilution by using flow injection and atomic absorption spectrophotometry is described. A sample throughout of 100 measurements per hour is possible. The coefficient of variation for within-run determination was about 1,14 and 2,36% for sodium and potassium, respectively, in serum samples (n=10). The method is easily adaptable to pediatric research, because of the low required sample volume of 5ul. (Author)

  2. Speciation of organometallic compounds by Zeeman atomic absorption spectrometry with liquid chromatography

    International Nuclear Information System (INIS)

    A method for the determination of organometallic compounds in the ppB range includes separation of the desired species with a high pressure liquid chromatograph and determination of the trace element by Zeeman atomic absorption spectrometry. The analysis of a mixture of vitamin B12 and Co(NO3)2 is described as a demonstration of the method. Determination of many enzymes and coenzymes having a metal ion in their functional center and of many toxic metals in environmental samples are other fields for application of this method

  3. Neutral atom beam technique enhances bioactivity of PEEK

    Energy Technology Data Exchange (ETDEWEB)

    Khoury, Joseph, E-mail: jkhoury@exogenesis.us [Exogenesis Corporation, Billerica, MA 01821 (United States); Kirkpatrick, Sean R.; Maxwell, Melissa; Cherian, Raymond E.; Kirkpatrick, Allen; Svrluga, Richard C. [Exogenesis Corporation, Billerica, MA 01821 (United States)

    2013-07-15

    Polyetheretherketone (PEEK) is currently gaining popularity in orthopedic and spinal applications but has potential drawbacks in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent; however, it has been shown to be inert and does not integrate well with bone. Recent efforts have focused on increasing the bioactivity of PEEK by modifying the surface to improve the bone-implant interface. We have employed a novel Accelerated Neutral Atom Beam technique (ANAB) to enhance the bioactivity of PEEK. ANAB employs an intense beam of cluster-like packets of accelerated unbonded neutral argon (Ar) gas atoms. These beams are created by first producing a highly energetic Gas Cluster Ion Beam (GCIB) comprised of van der Waals bonded Ar atoms, then transferring energy to the clusters so as to cause release of most of the interatomic bonds, and finally deflecting away the remaining electrically charged cluster cores of still bonded atoms. We identified that ANAB treatment of PEEK results in nanometer scale surface modifications as well as increased surface hydrophilicity. Human osteoblasts seeded onto the surface of ANAB-treated PEEK exhibited enhanced growth as compared to control PEEK as evidenced by cell proliferation assays and microscopy. This increase in bioactivity resulted in cell proliferation levels comparable to native titanium. An in vivo study using a rat calvarial critical size defect model revealed enhanced osseointegration where bone tissue formation was evident only on the ANAB treated PEEK. Taken together, these data suggest that ANAB treatment of PEEK has the potential to enhance its bioactivity, resulting in bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants.

  4. Neutral atom beam technique enhances bioactivity of PEEK

    International Nuclear Information System (INIS)

    Polyetheretherketone (PEEK) is currently gaining popularity in orthopedic and spinal applications but has potential drawbacks in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent; however, it has been shown to be inert and does not integrate well with bone. Recent efforts have focused on increasing the bioactivity of PEEK by modifying the surface to improve the bone-implant interface. We have employed a novel Accelerated Neutral Atom Beam technique (ANAB) to enhance the bioactivity of PEEK. ANAB employs an intense beam of cluster-like packets of accelerated unbonded neutral argon (Ar) gas atoms. These beams are created by first producing a highly energetic Gas Cluster Ion Beam (GCIB) comprised of van der Waals bonded Ar atoms, then transferring energy to the clusters so as to cause release of most of the interatomic bonds, and finally deflecting away the remaining electrically charged cluster cores of still bonded atoms. We identified that ANAB treatment of PEEK results in nanometer scale surface modifications as well as increased surface hydrophilicity. Human osteoblasts seeded onto the surface of ANAB-treated PEEK exhibited enhanced growth as compared to control PEEK as evidenced by cell proliferation assays and microscopy. This increase in bioactivity resulted in cell proliferation levels comparable to native titanium. An in vivo study using a rat calvarial critical size defect model revealed enhanced osseointegration where bone tissue formation was evident only on the ANAB treated PEEK. Taken together, these data suggest that ANAB treatment of PEEK has the potential to enhance its bioactivity, resulting in bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants

  5. Neutral atom beam technique enhances bioactivity of PEEK

    Science.gov (United States)

    Khoury, Joseph; Kirkpatrick, Sean R.; Maxwell, Melissa; Cherian, Raymond E.; Kirkpatrick, Allen; Svrluga, Richard C.

    2013-07-01

    Polyetheretherketone (PEEK) is currently gaining popularity in orthopedic and spinal applications but has potential drawbacks in use. PEEK is biocompatible, similar in elasticity to bone, and radiolucent; however, it has been shown to be inert and does not integrate well with bone. Recent efforts have focused on increasing the bioactivity of PEEK by modifying the surface to improve the bone-implant interface. We have employed a novel Accelerated Neutral Atom Beam technique (ANAB) to enhance the bioactivity of PEEK. ANAB employs an intense beam of cluster-like packets of accelerated unbonded neutral argon (Ar) gas atoms. These beams are created by first producing a highly energetic Gas Cluster Ion Beam (GCIB) comprised of van der Waals bonded Ar atoms, then transferring energy to the clusters so as to cause release of most of the interatomic bonds, and finally deflecting away the remaining electrically charged cluster cores of still bonded atoms. We identified that ANAB treatment of PEEK results in nanometer scale surface modifications as well as increased surface hydrophilicity. Human osteoblasts seeded onto the surface of ANAB-treated PEEK exhibited enhanced growth as compared to control PEEK as evidenced by cell proliferation assays and microscopy. This increase in bioactivity resulted in cell proliferation levels comparable to native titanium. An in vivo study using a rat calvarial critical size defect model revealed enhanced osseointegration where bone tissue formation was evident only on the ANAB treated PEEK. Taken together, these data suggest that ANAB treatment of PEEK has the potential to enhance its bioactivity, resulting in bone formation and significantly decreasing osseointegration time of orthopedic and spinal implants.

  6. DETERMINATION OF COPPER AND ZINC IN MINERAL WATERS BY ATOMIC ABSORPTION SPECTROPHOTOMETRY

    Directory of Open Access Journals (Sweden)

    Tatiana Mitina

    2011-12-01

    Full Text Available The content of copper and zinc in mineral waters were determined by atomic spectroscopy with preliminary extraction of metals. Validation of the technique was carried out by the method of standard additions and proved the reliability of analytical data.

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

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Nielsen, Steffen

    1998-01-01

    One of the advantages of the flow injection (FI) concept is that it is compatible with virtually all detection techniques. Being a versatile vehicle for enhancing the performance of the individual detection devices, the most spectacular results have possibly been obtained in conjunction with atomic...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-05-01

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

  9. Kaonic mass by critical absorption of kaonic-atom x rays

    Energy Technology Data Exchange (ETDEWEB)

    Lum, G.K.; Wiegand, C.E.; Kessler, E.G. Jr.; Deslattes, R.D.; Jacobs, L.; Schwitz, W.; Seki, R.

    1981-06-01

    The energy of x rays from the transition 6h..-->..5g in kaonic atoms of potassium falls on the K absorption edge of erbium. Measurement of the kaonic-x-ray attenuation in a precisely calibrated set of Er foils yields the x-ray energy 57 458.8 +- 6.3 eV. The kaon mass is related to energy through the Klein-Gordon equation plus corrections for radiative effects, electron screening, and other effects. The negative-kaon mass was found to be 493.640 +- 0.054 MeV/c/sup 2/ in agreement with the currently accepted value 493.669 +- 0.018 MeV/c/sup 2/ which was determined from x rays emitted by high-Z atoms where the corrections were larger than for Z = 19.

  10. Expressing self-absorption in the analytical function of inductively coupled plasma atomic emission spectrometry

    Science.gov (United States)

    Kántor, Tibor; Bartha, András

    2015-11-01

    The self-absorption of spectral lines was studied with up to date multi-element inductively coupled plasma atomic emission spectrometry (ICP-AES) instrumentation using radial and axial viewing of the plasma, as well, performing line peak height and line peak area measurements. Two resonance atomic and ionic lines of Cd and Mg were studied, the concentration range was extended up to 2000 mg/L. At the varying analyte concentration, constant matrix concentration of 10,000 mg/L Ca was ensured in the pneumatically nebulized solutions. The physical and the phenomenological formulation of the emission analytical function is overviewed and as the continuity of the earlier results the following equation is offered:

  11. Speciation analysis of thallium using solid phase extraction and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Complete text of publication follows. Thallium is a heavy, very toxic metallic element, which occurs in earth's crust in an estimated abundance from 0.1 to 0.8 mg.kg-1. In the environment, it is mainly combined with other elements (primarily oxygen, sulfur, halogens, potassium and rubidium) in inorganic compounds. During the weathering processes it can be mobilized by aqueous media and accumulated in sediments and soils. The main sources of pollution nowadays come from anthropogenic emissions from refineries, coal-fired power stations, mining activities, metal smelters and the cement industry. Thallium exists in natural waters as either Tl(I) (thallous) or Tl(III) (thallic) species. The oxidation state of Tl affects its complexation and subsequent bioavailability and toxicity in the environment. Thallium content in surface waters is within the range 1-82 ng l-1. Due to this low contents of Tl in water samples, it is necessary to combine the laboratory separation, preconcentration and determination techniques for the purpose of Tl speciation analysis. The scope of the presented work was to use an solid phase extraction (SPE) for the separation and preconcentration of Tl species in water samples followed by the determination using electrothermal atomic absorption spectrometry (ET AAS). In this method, Tl(III) was stabilized by formation of a Tl(III)-DTPA complex. Tl(I) species remained in its original form. These two species were then separated by using a cation exchange resin Amberlite IR120 and nitric acid as the eluent in a batch SPE protocol. The potential interferences of Fe (III), Al, Ca, Mg and other metals were investigated. The optimized experimental conditions for separation/preconcentration step (pH 2-3, time 15 min, temperature 60 deg C) and Zeeman ET AAS determination (chemical modifier Pd + ascorbic acid, atomization temperature 2100 deg C) were used for the speciation analysis of thallium in filtered acid water samples from open quartzite mine in the

  12. Exposure study by determination of blood lead levels using electro-thermal atomic absorption in correlation with basophilic stippling

    International Nuclear Information System (INIS)

    Blood lead levels were determined in fifty traffic police personnel exposed to open traffic deputed at various crossings in Rawalpindi/Islamabad by electro-thermal atomic absorption spectrophotometric technique to monitor the levels. Blood comparison of lead concentration in the blood samples of policemen working at high density area versus those working at low density area was made. The range of the blood lead levels of subjects working in the high density traffic is 7.2 - 19.6 up/dl whereas the blood lead levels of subjects at lean traffic is 0.4 - 6.9 Mu g /dL. The accuracy of the method was checked by analyzing SRM wheat flour, rice flour and bovine liver. The results obtained were compared with reported values of other countries as well as with the exposure limits of WHO. (author)

  13. Determination of total inorganic arsenic in potable water through spectroscopy of atomic absorption with generation of hydride

    International Nuclear Information System (INIS)

    Arsenic is an element that has been studied in the analysis of environmental samples for its toxicity showed in very low concentrations. The objective of this work is the validation of a method for the determination of total inorganic arsenic in drinking water. Through the spectrophotometric technique of atomic absorption an automatic system of flow injection for the generation of hydrides is used. The prereduction of Arsenic was made with potasium iodide 1,5% m/v and ascorbic acid 0.25% m/v dissolved in hydrochloric acid 3,7% m/v. The recuperation percentage of the method was 97 ± 3% in a dynamic range to 30 μg/L. The detection limit was 0,7 μg/L established over 0,5 mL of sample. The samples analyzed were found under the set limits of normative in Costa Rica of 10 μg/L. (author)

  14. Absorption measurement of thin films by using photothermal techniques: The influence of thermal properties

    International Nuclear Information System (INIS)

    Photothermal techniques are widely used for measuring optical absorption of thin film coatings. In these applications the calibration of photothermal signal is typically based on the assumption that the thermal properties of the thin film make very little contribution. In this paper we take mirage technique as an example and present a detailed analysis of the influence of thin film thermal properties on absorption measurements. The results show that the traditional calibration method is not valid on surprisingly many situations

  15. 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.

  16. Improvements in cobalt determination by thermospray flame furnace atomic absorption spectrometry using an on-line derivatization strategy.

    Science.gov (United States)

    Matos, Geraldo Domingues; Arruda, Marco Aurélio Zezzi

    2008-07-15

    An on-line derivatization strategy was developed for improving cobalt sensitivity using thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) as the analytical technique. This strategy involves the generation of a volatile cobalt compound, providing better sample vaporization efficiency. The effect of sodium diethyldithiocarbamate (DDTC) as complexing agent on the integrated absorbance signal was evaluated. Parameters including the pH of complex formation, complex concentration and volume, sample volume, flame gas composition and tube atomization configuration were optimized. A wide linear range (from 23 microg L(-1) to 3 mg L(-1); r(2)=0.9786) was obtained, with the best one (r(2)=0.9992) attained from 23 to 400 microg L(-1) with a sample throughput of 30 h(-1). The improvement in the detection power was 17-fold when compared to FAAS, which provides 7 microg L(-1) as the limit of detection when considered TS-FF-AAS technique. A relative standard deviation (n=10) of 4% for a cobalt solution containing 50 microg L(-1) was attained, and the accuracy of the procedure was evaluated through certified reference materials (IAEA-SL-1, lake sediment; and ISS-MURST-A1, Antarctic marine sediment). Good agreement between the results at the 95% confidence level was observed. PMID:18585309

  17. Determination of cadmium in bovine tissue by spectrophotometry of atomic absorption

    International Nuclear Information System (INIS)

    The present work utilized the suggested method by Food Safety and Inspection Service (FSIS) for the analysis of cadmium in animal tissue, it was adapted by the Toxicology's Laboratory of MAG, where the project was organized. This method consist of a burning of sample and the instrumental analysis by means of the atomic absorption's technique. In the study there were determined parameters of carrying out of the analytical methodology, it was getting the following values: linearity : 0,020 -1,0 mg/L; homogeneity of the model: homoscedastic; limit of detection (LD) : 0,0049 mg/kg (4,9 μg/Kg); limit of quantification (LC): 0,016 μg/L (16 mg/kg); sensibility of calibration: 0,243 A * L/gm; analytical sensibility: 105 L/mg; instrumental repetitively: < 4,3%; repetitively of gauges < 3,5%; reproducibility of methodology: 13,4% (expressed like variation's coefficient); truthfulness: 86,5%; selectivity and specificity: there isn't interferences of matrix, chemical or of ionization when the wavelength utilized is of 228,8 nm. It was made an study to determinate the present cadmium's quantities in three tissues of bovine origin; of an total of 20 animals there were gotten the following averages: muscles: 37,5 μg/kg, liver: 93,7 μg/kg and kidney: 253,4 μg/kg. Additionally, it was determined the correlation that exist among the contents of the metal and other variations, like sex, approximate age, as well as the stock sort: dairy or meat, where there were observed significant differences to a level of confidence of 95%, among the contents of Cadmium in muscle of meat stock and the dairy stock, being major the accumulation to the meat stock and the dairy stock, this like a difference of the other variations where didn't find a significant difference. Besides, it was determined, the metal's accumulation in two different kidney's zones: medullar and cortical, being significantly major in the last one, with a correlation of 99,5%. (Author)

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

    International Nuclear Information System (INIS)

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

  19. On the opportunity of spectroscopic determination of absolute atomic densities in non-equilibrium plasmas from measured relative intensities within resonance multiplets distorted by self-absorption

    CERN Document Server

    Lavrov, B P

    2007-01-01

    The opportunities of the application of the recently proposed approach in optical emission spectroscopy of non-equilibrium plasmas have been studied. The approach consists of several methods of the determination of {\\em absolute} particle densities of atoms from measured {\\em relative} intensities within resonance multiplets distorted by self-absorption. All available spectroscopic data concerning resonance spectral lines of atoms having multiplet ground states from boron up to gallium were analyzed. It is found that in the case of C, O, F, S and Cl atoms an application of the methods needs VUV technique, while densities of B, Al, Si, Sc, Ti, V, Co, Ni, Ga atoms may be obtained by means of the intensity measurements in UV and visible parts of emission spectra suitable for ordinary spectrometers used for optical diagnostics and monitoring of non-equilibrium plasmas including industrial plasma technologies.

  20. New niobium and rhenium halides synthesis routes by atomic vaporization. X-ray absorption spectroscopy characterization

    International Nuclear Information System (INIS)

    New synthetic route as the so called 'chimie douce' or MVS (Metal Vapor Synthesis) has been an increasing field lately to synthesize new kind of solid state structures. Our interest is the assembly of small molecular building blocks of early transition metal halides. We illustrate the use of vaporized rare earth metals to condense NbCls units. We probed the local order around the Nb atom with X-Ray Absorption Spectroscopy, far Infra-Red and XPS in order to better understand the mechanisms involved. A first EXAFS, IR and XPS study on solid state products has shown the evolution of the NbCl5 dimer towards a chain like structure. However, the condensation patterns depends on the rare earth atoms vaporized. These results have been confirmed by X-ray Absorption ab initio calculations. Because our compounds are extremely air sensitive we have developed in situ MVS reactor to take 'snapshots' of the structural intermediates by EXAFS. This study showed the condensation of the initial NbCl5 building blocks by reduction of the Nb oxidation state by rare earth vaporization. This method is a new way of looking at condensation mechanisms via structural evolution observed by EXAFS. (author)

  1. Atomic absorption spectroscopic, conductometric and colorimetric methods for determination of some fluoroquinolone antibacterials using ammonium reineckate

    Science.gov (United States)

    Al-Ghannam, Sheikha M.

    2008-04-01

    Three accurate, rapid and simple atomic absorption spectrometric (AAS), conductometric and colorimetric methods were developed for the determination of gatifloxacin (GTF), moxifloxacin (MXF) and sparfloxacin (SPF). The proposed methods depend upon the reaction of ammonium reineckate with the studied drugs to form stable precipitate of ion-pair complexes, which was dissolved in acetone. The pink coloured complexes were determined either by AAS or colorimetrically at λmax 525 nm directly using the dissolved complex. Using conductometric titration, the studied drugs could be evaluated in 50% (v/v) acetone. The optimizations of various experimental conditions were described. Optimum concentration ranges for the determination of GTF, MXF and SPF were 5.0-150, 40-440 μg mL -1 and 0.10-1.5 mg mL -1 using atomic absorption (AAS), conductometric and colorimetric methods, respectively. Detection and quantification limits are ranges from 1.5 to 2.3 μg mL -1 using AAS method or 30-45 μg mL -1 using colorimetric method. The proposed procedures have been applied successfully to the analysis of these drugs in pharmaceutical formulations and the results are favourably comparable to the reference methods.

  2. Determination of trace elements in ground water by two preconcentration methods using atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This is a comparative study between two different methods of preconcentration done to separate the trace elements cadmium, nickel. chromium, manganese, copper, zinc, and lead in drinking (ground) water samples taken from different locations in Gezira State, central Sudan (the map); these methods are (coprecipitation) with aluminium hydroxide and by Ammonium Pyrrolidine Dithiocarbamate (APDC) using Methyl Isobutyl Ketone (MIBK) as an organic solvent; and subsequent analysis by Atomic Absorption Spectrometry (AAS) for both methods. The result of comparison showed the superiority of the (APDC) coprecipitation method over the aluminium hydroxide coprecipitation method in the total percentage recoveries of the studied trace elements in drinking (ground) water samples, such results confirm previous studies. This study also involves direct analysis of these water samples by atomic absorption spectrometry to determine the concentrations of trace elements Cadmium, Nickel, Chromium, Manganese, Copper, Zinc and Lead and compare it to the corresponding guide line values described by the World Health Organization and the maximum concentrations of trace elements in drinking water permitted by the Sudanese Standards and Metrology Organizations (SSMO), where the concentrations of some elements in some samples were found to be different than the described values by both of the organizations. The study includes a trial to throw light on the effect of the proximity of the water samples sources to the Blue Nile river on its trace elements concentrations; no relation was proved to exist in that respect.(Author)

  3. Determination of Elements by Atomic Absorption Spectrometry in Medicinal Plants Employed to Alleviate Common Cold Symptoms

    Institute of Scientific and Technical Information of China (English)

    F Zehra Küçükbay; Ebru Kuyumcu

    2014-01-01

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

  4. Direct determination of lead in sweet fruit-flavored powder drinks by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Lima, Éder C.; Krug, Francisco José; Arruda, Marco A. Z.

    1998-04-01

    A simplified method for direct determination of lead in sweet fruit-flavored powder drinks, syrups and honeys by electrothermal atomic absorption spectrometry without sample digestion is proposed. Samples were dissolved in water, acidified to 0.2% (v/v) HNO 3, and directly injected into an end-capped transversely heated graphite atomizer (THGA). Building up of carbonaceous residue inside the atomizer was effectively precluded for sugar solutions not exceeding 8.0% (m/v) when a heating program with two pyrolysis steps (600 and 1000°C) was carried out without air-ashing. Under these conditions one atomizer supported about 250 firings. Among various chemical modifiers tested, better recovery and repeatability results were obtained with a 5 μg Pd + 3 μg Mg(NO 3) 2 mixture. Tests carried out with individual concomitants containing up to 1.0 μg Na, K, Ca or Cl, and up to 10.0 μg phosphate or sulphate, and several mixtures of these six concomitants, did not reveal significant interferences on lead atomization. Characteristic mass and detection limit based on integrated absorbance were 15 and 11 pg Pb, respectively. The relative standard deviation based on 10 measurements for typical samples (20-60 ng g -1 Pb) was always lower than 5.5%. The detection limit of 7.0 ng g -1 Pb attained the Codex recommendation for the maximum allowed lead contents in the sugar samples. Application of t-test to the results obtained by the proposed direct analysis, and the official method adopted by Food Chemical Codex, demonstrated that there were no significant differences at the 5% probability level.

  5. Determination of lead in dolomite by Zeeman electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The mineral lorandite (TlAsS2), present in the Alshar deposit (Republic of Macedonia), is a possible solar neutrino detector (Freedman et al., 1976). As a result of nuclear reaction between the isotopes of thallium 205Tl and the solar neutrino, 205 Pb is produced. The aim of the idea is to determine the content of Pb in the lorandite, that could give information for the value of solar neutrino flux over extended time (Pavicevic, 1994). A method for the lead determination in dolomite by Zeeman electrothermal atomic absorption spectrometry, is presented. After the dissolution of samples, lead was extracted with sodium diethyldithio-carbamate. The lead-diethyldithiocarbamate complex was extracted into methylisobutyl ketone from a medium of pH 6.0-10.0. The procedure was verified by method of standard additions and by analyzing referent standard samples. A calibration curve (for organic solutions containing up to 1 ng Pb) was made using the proposed extraction procedure for standard solutions of lead. The standard deviation (SD) for 0.5 ng Pb is 0.01 ng and the relative standard deviation ranges from 2.5 to 3.5%. The detection limit of the method, calculated as 3 SD of the blank, was found to be 1.5 ng.g-1. The operation conditions in electrothermal atomic absorption measurements (temperature and time) were: drying - 90oC, 20 s; charring - 400oC, 20 s; atomizing - 1900oC, 3 s; cleaning - 2650oC, 3 s (Author)

  6. Assessment of cadmium and iron adsorption in sediment, employing a flow injection analysis system with on line filtration and detection by flame atomic absorption spectrometry and thermospray flame furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •A FIA system with on-line filtration for isotherms adsorption studies was proposed. •Isotherms for iron and cadmium elements in bottom lake sediment were done. •Inferences about adsorption/desorption mechanisms were feasible. •The proposed method turns the isotherm studies fast and reliable. -- Abstract: This work presents an evaluation of iron and cadmium adsorption in sediment of the Furnas Hydroelectric Plant Reservatory located in Alfenas, Minas Gerais (Brazil). The metal determination was done employing a flow injection analysis (FIA) with an on-line filtering system. As detection techniques, flame atomic absorption spectrometry (FAAS) for iron and thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) for cadmium determinations were used. The developed methodology presented good limits of detection, being 190 μg L−1 for iron and 1.36 μg L−1 for cadmium, and high sampling frequency for both metals 144 and 60 readings h−1 for iron and cadmium, respectively. Both metals obey the Langmuir model, with maximum adsorptive capacity of 0⋅169 mg g−1 for iron and 7⋅991 mg g−1 for cadmium. For iron, a pseudo-first-order kinetic model was obtained with a theoretical Qe = 9⋅8355 mg g−1 (experimental Qe = 9⋅5432 mg g−1), while for cadmium, a pseudo-second-order kinetic model was obtained, with a theoretical Qe = 0.3123 mg g−1 (experimental Qe = 0⋅3052 mg g−1)

  7. Measurement of the Si atom density in RF silane plasma using absorption spectroscopy

    International Nuclear Information System (INIS)

    Quantitative measurements of various radical species in silane plasma are indispensable for the clarification of the amorphous silicon thin film formation mechanism. Therefore is necessary also to measure the Si atom density as well as the SiH3, SiH2 and SiH radical densities. Although there are few reports about the Si atom density, the measurements were made only at the low silane concentrations of 1--9% in the SiH4/Ar gas mixture for the 3p23P2 ground level. In this work, the authors have measured the Si atom densities at two levels 3p23P2 and 3p21D2 in on-off modulated RF (13.56 MHz) SiH4/Ar plasma using an uv absorption method. The silane concentration was varied in the wide region of 5 to 100% to investigate the behaviors of the two Si densities in the gas mixture

  8. Evaluation on corrosively dissolved gold induced by alkanethiol monolayer with atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    We have monitored a gold corrosive dissolution behavior accompanied in n-alkanethiol like n-dodecanethiol assembled process with in situ quartz crystal microbalance (QCM), and then observed it with atomic force microscopy (AFM) which showed an evident image of corrosive defects or holes produced on gold substrate, corresponding to gold dissolution induced by the alkanethiol molecules in the presence of oxygen. For detection of the dissolved gold defects during alkanethiol assembled process, an atomic absorption spectroscopy (AAS) has been carried out in this paper, and the detection limit for the dissolved gold could be evaluated to be 15.4 ng/mL. The amount of dissolved gold from the substrates of gold plates as functions of immersion time, acid media, solvents and thiol concentration has been examined in the oxygen saturated solutions. In comparison with in situ QCM method, the kinetics behavior of the long-term gold corrosion on the gold plates in 1.0 mmol/L of n-dodecanethiol solution determined with AAS method was a slow process, and its corrosion rate on gold dissolution could be evaluated to be about 4.4 x 10-5 ng.cm-2.s-1, corresponding to 1.3 x 108 Au atoms.cm-2.s-1, that was much smaller than that of initial rate monitored with in situ QCM. Both kinetics equations obtained with QCM and AAS showed a consistent corrosion behavior on gold surfaces.

  9. Determination of heavy metals in imported food for Libyan marketing by using Atomic Absorption Spectrometer (AAS)

    International Nuclear Information System (INIS)

    Nowadays, it becomes difficult to differentiate between essential and toxic elements, since all elements are toxic if their concentration is exceeded the permissible level recommended by the world health organization (WHO). In some instances the recommended and toxicity levels are close, therefore; it is necessary to differentiate between these essential and toxic levels even in very low concentrations. Several thousands of imported food samples (5877), including: canned soft drinks and juices, biscuits, baking powder, canned tomato past, canned hot spice, canned infant milk, canned concentrated milk, chocolates, canned tuna, and canned oil, were collected randomly from different markets around the country. The samples were analyzed for heavy metals: Cu, Zn, Fe, Sn, As, Pb, and Hg, by atomic absorption spectrometer (AAS), using flame atomization for Cu, Zn, and Fe, hydride generation (HG) for Sn and As, cold vapor for Hg and electrothermal atomization for Pb determination. The obtained AAS results were compared with the Libyan and international food specifications. Most of the samples analyzed were within the specification range and only a little have higher heavy metals level. (Authors)

  10. Different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry: Cadmium determination in whole blood as a case study

    International Nuclear Information System (INIS)

    In the present work the performance of different platform and tube geometries and atomization temperatures in graphite furnace atomic absorption spectrometry was investigated, using the determination of Cd in whole blood as an example. Grooved, integrated and fork platforms as well as atomization temperatures between 1200 deg. C and 2200 deg. C were investigated in a longitudinally heated graphite atomizer and compared with the performance of a transversely heated furnace. In the longitudinally heated furnace the increase of the atomization temperature in the studied range resulted in an increase of matrix effects for all platform geometries. The integrated platform exhibited slightly lower sensitivity and increased multiplicative interferences in comparison to the other two platform designs. Interference-free Cd determination was possible with all types of platforms and 1200 deg. C as the atomization temperature as well as with grooved and fork platforms at 1700 deg. C. On the other hand, lower atomization temperatures resulted in poorer limits of detection, due to the longer integration time needed. No matrix effect was observed at any atomization temperature using the transversely heated atomizer; in addition, limits of detection were better than those observed with the longitudinally heated atomizer. Best values were around 0.02 μg L-1 with the latter atomizer compared to values around 0.02 μg L-1 with the former one

  11. Determination of bismuth in environmental samples by slurry sampling graphite furnace atomic absorption spectrometry using combined chemical modifiers.

    Science.gov (United States)

    Dobrowolski, Ryszard; Dobrzyńska, Joanna; Gawrońska, Barbara

    2015-01-01

    Slurry sampling graphite furnace atomic absorption spectrometry technique was applied for the determination of Bi in environmental samples. The study focused on the effect of Zr, Ti, Nb and W carbides, as permanent modifiers, on the Bi signal. Because of its highest thermal and chemical stability and ability to substantially increase Bi signal, NbC was chosen as the most effective modifier. The temperature programme applied for Bi determination was optimized based on the pyrolysis and atomization curves obtained for slurries prepared from certified reference materials (CRMs) of the soil and sediments. To overcome interferences caused by sulfur compounds, Ba(NO₃)₂ was used as a chemical modifier. Calibration was performed using the aqueous standard solutions. The analysis of the CRMs confirmed the reliability of the proposed analytical method. The characteristic mass for Bi was determined to be 16 pg with the detection limit of 50 ng/g for the optimized procedure at the 5% (w/v) slurry concentration. PMID:25384374

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

    Science.gov (United States)

    Dobrowolski, Ryszard; Adamczyk, Agnieszka; Otto, Magdalena

    2013-09-15

    A new analytical procedure for vanadium (V) determination in soils and sediments by the slurry sampling graphite furnace atomic absorption spectrometry (slurry sampling GFAAS) using the mixed permanent modifiers is described. Moreover, the comparison of action of the modifiers based on the iridium (Ir) and carbide-forming elements: tungsten (W) and niobium (Nb) deposited on the graphite tubes is studied, especially in terms of their analytical utility and determination sensitivity. The mechanism of their action was investigated using an X-ray diffraction technique (XRD) and scanning electron microscopy (SEM) equipped with an energy dispersive X-ray detector (EDX). Finally, the mixture of 0.3 μg of Ir and 0.04 μg of Nb was used for the graphite tube permanent modification. The analytical procedure was optimized on the basis of the data from pyrolysis and atomization temperature curves studies. The results obtained for the four certified reference materials (marine sediments: PACS-1 and MESS-1, lake sediment: SL-1, soil: San Joaquin Soil SRM 2709), using the slurry sampling GFAAS and the standard calibration method, were in good agreement with the certified values. The detection and quantification limits and characteristic mass calculated for the proposed procedure were 0.04 µg/g, 0.16 µg/g and 11.9 pg, respectively. The precision (RSD% less than 8%) and the accuracy of vanadium determination in the soil and sediment samples were acceptable. PMID:23708618

  13. Determination of total inorganic arsenic in potable water through spectroscopy of atomic absorption with generation of hydride

    International Nuclear Information System (INIS)

    This study developed a method for the cuantitative analysis of arsenic in potable water , through the spectrophotometric technique of atomic absorption. It used an automatic system of injection of flux for the generation of hydrides. It studied the effect produced by reducer agents, in the prereduction of arsenic in water, obtaining the best result with the use of potasium iodide 1.5% and ascorbic acid 0.25% in hydrochloric acid 3.7%, for the direct determination of total inorganic arsenic. It observed the effect produced by cadmium and selenium to the half of the concentration of arsenic, chromium, lead and silver at the same concentration, and barium at a ten times higher concentration, in the recuperation of total inorganic arsenic. It also used sodium borohydride 0.3% in sodium hydroxide 0.05% (5mL/min), for the formation of the volatile hydrides. It used hydrochloric acid 3.7% (12 mL/min) as disolution of transport; argon as inert gas, and a flame air-acetylene, for the atomization of the hydrides. This method was applied to 19 samples of potable water, and the result was no detectable for all of them. (S. Grainger)

  14. Investigation of lead contents in lipsticks by solid sampling high resolution continuum source electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Gunduz, Sema; Akman, Suleyman

    2013-02-01

    In this study, the lead contents of different kinds of lipsticks were determined by solid sampling high resolution continuum source electrothermal atomic absorption spectrometry (SS-HR-CS ET AAS) and the results were compared with those obtained after microwave-assisted acid digestion of the samples. The experimental parameters for solid sampling such as the maximum amount of sample on the platforms of solid autosampler, graphite furnace program were optimized. Samples were directly loaded on the platforms of solid autosampler between 0.25 and 2.0mg and lead was determined applying 800 °C for pyrolysis and 2100 °C for atomization. Under optimized conditions, interference-free determination could be performed using aqueous standards. The LOD and the characteristic mass were 21.3 and 12.6 pg, respectively. The lead in the same lipstick samples was determined after microwave-assisted acid digestion and compared with those found by solid sampling. Mostly, there was no significant difference between the lead concentrations found by the two techniques. The lead in 25 lipstick samples with different properties were 0.11-4.48 ng mg(-1) which were not significantly different from those (<0.026-7.19 ng mg(-1)) reported by FDA for around 400 samples. PMID:23099440

  15. Analysis of soil reference materials for vanadium(+5) species by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Solid Certified Reference Materials (CRMs) with known vanadium(+5) content are currently not commercially available. Because of this, vanadium species have been determined in solid CRMs of soil, viz. CRM023-50, CRM024-50, CRM049-50, SQC001 and SQC0012. These CRMs are certified with only total vanadium content. Vanadium(+5) was extracted from soil reference materials with 0.1 M Na2CO3. The quantification of V(+5) was carried out by electrothermal atomic absorption spectrometry (ET-AAS). The concentration of V(+5) in the analyzed CRMs was found to be ranging between 3.60 and 86.0 μg g-1. It was also found that SQC001 contains approximately 88% of vanadium as V(+5) species. Statistical evaluation of the results of the two methods by paired t-test was in good agreement at 95% level of confidence.

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

    International Nuclear Information System (INIS)

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

  17. A summary of transition probabilities for atomic absorption lines formed in low-density clouds

    Science.gov (United States)

    Morton, D. C.; Smith, W. H.

    1973-01-01

    A table of wavelengths, statistical weights, and excitation energies is given for 944 atomic spectral lines in 221 multiplets whose lower energy levels lie below 0.275 eV. Oscillator strengths were adopted for 635 lines in 155 multiplets from the available experimental and theoretical determinations. Radiation damping constants also were derived for most of these lines. This table contains the lines most likely to be observed in absorption in interstellar clouds, circumstellar shells, and the clouds in the direction of quasars where neither the particle density nor the radiation density is high enough to populate the higher levels. All ions of all elements from hydrogen to zinc are included which have resonance lines longward of 912 A, although a number of weaker lines of neutrals and first ions have been omitted.

  18. Determination of Trace Selenium in Electrolytic Manganese by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    YAO Jun; ZHOU Fang-qin; MA Cheng-jin; TUO Yong; LIU Jian-ben; WU Zhu-qin; TAN Zhu-zhong

    2003-01-01

    The effects of four types of graphite tube and five matrix modifiers on the determination of selenium by graphite furnace atomic absorption spectrometry were compared.The results show that platform thermolysis coat graphite tube and magnesium nitrate and cobaltco as matrix modifer can get a high sensitivity and a good recovery.The optimized working conditions and interference in the determination were invesigated.This result is consistent with that of XRF.The recovery is from 100.8 % to102.2 %,the relative standard deviation is from 3.47% to 5.56 % (n=9),and the detection limit of selenium is 378 pg (C=44.5μg/g to 97.3μg/g.).The proposed method can be applied to the rapid determination of selenium in electrolytic manganese.

  19. Laser absorption spectroscopy diagnostics of helium metastable atoms generated in dielectric barrier discharge cryoplasmas

    Science.gov (United States)

    Urabe, Keiichiro; Muneoka, Hitoshi; Stauss, Sven; Sakai, Osamu; Terashima, Kazuo

    2015-10-01

    Cryoplasmas, which are plasmas whose gas temperatures are below room temperature (RT), have shown dynamic changes in their physical and chemical characteristics when the gas temperature in the plasmas (Tgp) was decreased from RT. In this study, we measured the temporal behavior of helium metastable (Hem) atoms generated in a parallel-plate dielectric barrier discharge at ambient gas temperatures (Tga) of 300, 100, and 14 K and with a gas density similar to atmospheric conditions by laser absorption spectroscopy. The increments of Tgp to Tga were less than 20 K. We found from the results that the Hem lifetime and maximum density become longer and larger over one order of magnitude for lower Tga. The reasons for the long Hem lifetime at low Tga are decreases in the rate coefficients of three-body Hem quenching reactions and in the amounts of molecular impurities with boiling points higher than that of He.

  20. Removal of iron interferences by solvent extraction for geochemical analysis by atomic-absorption spectrophotometry

    Science.gov (United States)

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

    1985-01-01

    Iron is a common interferent in the determination of many elements in geochemical samples. Two approaches for its removal have been taken. The first involves removal of iron by extraction with methyl isobutyl ketone (MIBK) from hydrochloric acid medium, leaving the analytes in the aqueous phase. The second consists of reduction of iron(III) to iron(II) by ascorbic acid to minimize its extraction into MIBK, so that the analytes may be isolated by extraction. Elements of interest can then be determined using the aqueous solution or the organic extract, as appropriate. Operating factors such as the concentration of hydrochloric acid, amounts of iron present, number of extractions, the presence or absence of a salting-out agent, and the optimum ratio of ascorbic acid to iron have been determined. These factors have general applications in geochemical analysis by atomic-absorption spectrophotometry. ?? 1985.

  1. Indirect determination of trace phenol in water by atomic-absorption spectrophotometry.

    Science.gov (United States)

    Bo-Xing, X; Tong-Ming, X; Ming-Neng, S; Yu-Zhi, F

    1985-03-01

    An indirect method for determination of trace phenol in water by atomic-absorption spectrophotometry (AAS) is described. The phenol is brominated in acidic solution with KBrO(3)-KBr solution at room temperature. The excess of bromine is reacted with KI and the I(2) produced is extracted into cyclohexane and then reduced back to I(-) with ascorbic acid. The I(-) is then complexed with Cd(2+) in sulphuric acid medium and the complex extracted into MIBK. The extract is analysed by flame AAS for Cd (and hence indirectly for phenol). The linear concentration range for determination of phenol is 6 x 10(-7)-0.9 x 10(-5)M in aqueous solution. Several foreign ions and organic substances do not interfere. PMID:18963829

  2. An atomic-absorption method for the determination of gold in large samples of geologic materials

    Science.gov (United States)

    VanSickle, Gordon H.; Lakin, Hubert William

    1968-01-01

    A laboratory method for the determination of gold in large (100-gram) samples has been developed for use in the study of the gold content of placer deposits and of trace amounts of gold in other geologic materials. In this method the sample is digested with bromine and ethyl ether, the gold is extracted into methyl isobutyl ketone, and the determination is made by atomicabsorption spectrophotometry. The lower limit of detection is 0.005 part per million in the sample. The few data obtained so far by this method agree favorably with those obtained by assay and by other atomic-absorption methods. About 25 determinations can be made per man-day.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  4. On mechanism of buffer action of La and Sr in atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    A possible mechanism is considered for eliminating the effect of a number of macrocomponents on the determination of alkali earth elements with the addition of La and Sr salts. It is shown that the macroelements with the strongest effect in atom absorption flame spectroscopy are the basic elements of rocks. It is established that the effect increases in the order: Fe, Al, Si, i.e., as the crystal chemical radii of the cations decreases. It is suggested that the effect of La, Sr, Ba and other buffer element with large cations very probably leads to an increase in the diffusion coe'ficient of a determined element in less ''dense'' structures than the depressing component which are formed by the buffer element

  5. Levels of trace elements in different varieties of wheat determined by Atomic Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Trace elements Ag, Au, Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr and Zn were determined in six wheat samples purchased from the open market in different localities (Egypt, Saudi Arabia, Yemen, Oman, Dubai and Australia). The dried powdered samples were decomposed in HNO3-HClO4 acids mixtures and elements were determined using recording atomic absorption spectrophotometer. The results were within the safety baseline of all the assayed elements. Certified biological standards, Brown's Kale (BK), Orchard Leaves (OL) and tomato leaves (TOML) were used to assure the accuracy of results. However, Co, Pb and Sr were absent from samples except the Egyptian samples. The obtained databases were statistically treated. Several significant and strong positive correlation coefficients (r=0.506-1.00) between the groups of elements were observed. On the other hand, strong negative correlations (r=0.492-0.873) between another group of elements were also shown. (author)

  6. Determination of lanthanides in yttrium and praseodymium oxides by atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    The operational conditions for the graphite furnace, the instrumental parameters and the sensitivity for the determination of Pr, Nd, Sm, Eu, Y, Gd, Dy, Er, Ho, Tm, and Yb in Y2O3 and Pr2O3 by atomic absorption spectrophotometry are presented. The analyses were carried out into a highly pure argon atmosphere and using pyrolytic graphite tube and graphite supporting electrodes. The accuracy and precision of the method were checked through analyses of synthetic lanthanides mixtures. The concentration range of the lanthanides varied from 0,003 to 3,5% in Y2O3 and from 0,001 to 3,5% in Pr2O3. (Author)

  7. The direct determination of HgS by thermal desorption coupled with atomic absorption spectrometry

    Science.gov (United States)

    Coufalík, Pavel; Zvěřina, Ondřej; Komárek, Josef

    2016-04-01

    This research was aimed at the direct determination of HgS in environmental samples by means of thermal desorption coupled with atomic absorption spectrometry. Operating parameters of the apparatus used for thermal desorption (including a prototype desorption unit) are described in this work, as well as the procedure for measuring mercury release curves together with an evaluation of the analytical signal including two methods of peak integration. The results of thermal desorption were compared with HgS contents obtained by sequential extraction. The limits of quantification of the proposed method for the selective determination of the black and red forms of HgS were 4 μg kg- 1 and 5 μg kg- 1, respectively. The limit of quantification of red HgS in soils was 35 μg kg- 1. The developed analytical procedure was applied to soil and sediment samples from historical mining areas.

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

    Science.gov (United States)

    Çiftçi, Tülin Deniz; Henden, Emur

    2016-08-01

    Arsenic in drinking water is a serious problem for human health. Since the toxicity of arsenic species As(III) and As(V) is different, it is important to determine the concentrations separately. Therefore, it is necessary to develop an accurate and sensitive method for the speciation of arsenic. It was intended with this work to determine the concentrations of arsenic species in water samples collected from Izmir, Manisa and nearby areas. A batch type hydride generation atomic absorption spectrometer was used. As(V) gave no signal under the optimal measurement conditions of As(III). A certified reference drinking water was analyzed by the method and the results showed excellent agreement with the reported values. The procedure was applied to 34 water samples. Eleven tap water, two spring water, 19 artesian well water and two thermal water samples were analyzed under the optimal conditions. PMID:27236436

  9. 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.

  10. Influences of the matrix effect in the sensibility of cobalt measurement by atomic absorption

    International Nuclear Information System (INIS)

    The interferences caused by iron, aluminium, calcium, magnesium, manganese, copper, nickel, zinc, sodium and potassium in the determination of cobalt by atomic absorption, were studied. The concentrations of cobalt were varied in the range of 1 to 800 μg/ml and the concentrations of the interferents in the proportions occuring normally in soils, rocks, sediments, geological material in general, alloys, caustic liquors etc. To study the flame composition effect, the flame region effect and also the effect of different interferent concentrations on the cobalt for each selected spectral line, an air-acetilene flame was utilized. As an application of this study the effect was shown of 'simulated soil matrices' with respect to the interference of iron on cobalt

  11. Preconcentration of Vanadium(Ⅴ) on Crosslinked Chitosan and Determination by Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method is proposed for the preconcentration of vanadium(Ⅴ) with crosslinked chitosan (CCTS) and determination by graphite furnace atomic absorption spectrometry (GFAAS). The adsorption rate of vanadium(Ⅴ) by CCTS was 97% at pH 4.0, and vanadium(Ⅴ) was eluted from crosslinked chitosan with 2 mL 2.0 mol*L-1 chlorhydric acid and determined by GFAAS. The detection limit (3σ,n=7) for vanadium(Ⅴ) was 4.8×1 0-12g and the relative standard deviation (R.S.D) at concentration level of 2.6 μg*L-1 is less than 3.6%. The method shows a good selectivity and high sensitivity, and it was applied to determination of vanadium(Ⅴ) in oyster and water samples. The analytic recoveries are (97±5)%.

  12. Elemental investigation of momordica charantia linn. and syzigium jambolana linn. using atomic absorption spectrophotometer

    International Nuclear Information System (INIS)

    Elemental investigation of very important medicinal plant i.e. momordica charantia linn and syzigium jambolana linn, and its decoction has been carried out using flame atomic absorption spectrophotometer. In present study fifteen essential, trace and toxic elements such as Zn, Cr, K, Mg, Ca, Na, Cu, Fe, Pb, Al, Ba, Mn, Co, Ni and Cd were determined in different parts of both plants and in its decoction. The level of essential elements was found high as compared to the level of toxic elements. Both plants are useful in the treatment of diabetes. The validation of the method was checked by employing NBS- 1570 (Spanish) as a standard reference material . The measured values of elements are in close agreement with certified values. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-09-24

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

  14. Simultaneous determination of selenium and tellurium in native sulfur by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    A method for the determination of selenium and tellurium in native sulfur has been investigated by means of atomic absorption spectrophotometry. Native sulfur collected from around fumarole or volcanic crater is ground down into powder, a portion of which weighing 1 g is subjected to analysis. A 2.6% (w/v) sodium hydroxide solution is added by 10 ml to the sample in a teflon beaker, and the mixture is then heated on a hot plate. Sulfur is decomposed and dissolved in the form of disulfide and thiosulfate. A 30% hydrogenperoxide solution is added by 10 ml to oxidize them to sulfate. At the same time selenium and tellurium contained in the sulfur sample are also thought to be oxidized to Se(VI) and Te(VI) states. The solution is neutralized with hydrochloric acid and diluted with distilled water to 100 ml. The sample solution thus prepared is sprayed into the air-acetylene flame of the atomic absorption spectrophotometer. The absorbance is measured at 195.9 nm for selenium and 214.2 nm for tellurium. Calibration curve is prepared by measuring the absorbances of the solutions prepared as follows. One gram portions of pure sulfur (99.9999%) are decomposed as for the samples. After neutralization, standard solutions containing each same amount of selenium and tellurium (0 -- 1000 μg) are added to the sulfur solution and then diluted with water to 100 ml. The standard deviations were estimated to be 50.4 ppm for selenium at 756 ppm and 16.6 ppm for tellurium at 587 ppm. For the check of the reliability of the method, results were compared with those obtained by neutron activation analysis. Results obtained by both methods showed good agreement. (author)

  15. Interference Effects on the Probe Absorption in a Driven Three-Level Atomic System by a Coherent Pumping Field

    International Nuclear Information System (INIS)

    In this work we analyze the properties of weak probe absorption in a closed three-level atomic system driven by a coherent driving field. The effects of quantum interference from spontaneous emission on the refractive properties in a closed three-level atomic system driven by a coherent pumping field are included into the gain modeling. The density-matrix equations of motion are solved by following perturbation approach and the probe response function is constructed. The probe absorption is obtained by solving Maxwell's equation for propagation of the probe field of slowly varying amplitude. Analytical and numerical simulation of quantum interference effect between the spontaneous decay channels on the absorptive response of a weak probe field in a closed three-level atomic system driven by a coherent driving field, as well as the evolution of probe gain under coherent pumping mode is studied in laser-produced carbon and aluminum plasma with laser intensity > 1010W/cm2. (author)

  16. Atomic structure of Mn-rich nanocolumns probed by x-ray absorption spectroscopy

    Science.gov (United States)

    Rovezzi, M.; Devillers, T.; Arras, E.; d'Acapito, F.; Barski, A.; Jamet, M.; Pochet, P.

    2008-06-01

    In this letter, we have used the extended x-ray-absorption fine-structure (EXAFS) technique to investigate the structure of Mn-rich self-organized nanocolumns grown by low temperature molecular beam epitaxy. The EXAFS analysis has shown that Mn-rich nanocolumns exhibit a complex local structure that cannot be described by a simple substitutional model. Additional interatomic distances had to be considered in the EXAFS model which are in excellent agreement with the structure of a Ge-3Mn building block tetrahedron of Ge3Mn5.

  17. Wet sample digestion for quantification of vanadium(V) in serum by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Three types of pressure digestion systems used prior to the determination of the ultratrace element vanadium by electrothermal atomic absorption spectrometry were evaluated: The high-pressure ashing (HPA) system, the DAB III pressure digestion system and the pressurized microwave digestion (PMD) system. Complete sample digestion and no loss of graphite tube sensitivity as well as reliable vanadium values could only be achieved with HPA digests of freeze-dried serum. The mean recovery rate was 98% and no loss of tube sensitivity could be observed. Using non-lyophilized serum the mean recovery rate was 70%. The DAB III digestion system, vicarious for closed pressure digestion in steel bombs with an allowable temperature up to about 200C, cannot be recommended to mineralize human biological material for vanadium determinations, because the remaining not completely decomposed organic compounds extracted together with the vanadium-cupferron complex caused a marked carbon-buildup and formation of carbides in the graphite tube were found to change the shape of the absorption signals distinctly, and to decline the tube sensitivity strongly (about 25%) so that reliable results cannot be achieved. The recovery rate was too low in general (about 50%). In addition, a subsequent treatment of the DAB III digests with perchloric acid was unsuccessful. The PMD system proved to be not suited, because the samples became highly contaminated by vanadium possibly from the titan seal. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  18. Arecibo Multi-Epoch HI Absorption Measurements Against Pulsars: Tiny-Scale Atomic Structure

    CERN Document Server

    Stanimirovic, S; Pei, Z; Tuttle, K; Green, J T

    2010-01-01

    We present results from multi-epoch neutral hydrogen (HI) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10--150 AU/yr, these pulsars have swept across 1--200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their HI absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 10-1000 AU, as previously suggested by some work. In the direction of B1929+10, an...

  19. ARECIBO MULTI-EPOCH H I ABSORPTION MEASUREMENTS AGAINST PULSARS: TINY-SCALE ATOMIC STRUCTURE

    International Nuclear Information System (INIS)

    We present results from multi-epoch neutral hydrogen (H I) absorption observations of six bright pulsars with the Arecibo telescope. Moving through the interstellar medium (ISM) with transverse velocities of 10-150 AU yr-1, these pulsars have swept across 1-200 AU over the course of our experiment, allowing us to probe the existence and properties of the tiny-scale atomic structure (TSAS) in the cold neutral medium (CNM). While most of the observed pulsars show no significant change in their H I absorption spectra, we have identified at least two clear TSAS-induced opacity variations in the direction of B1929+10. These observations require strong spatial inhomogeneities in either the TSAS clouds' physical properties themselves or else in the clouds' galactic distribution. While TSAS is occasionally detected on spatial scales down to 10 AU, it is too rare to be characterized by a spectrum of turbulent CNM fluctuations on scales of 101-103 AU, as previously suggested by some work. In the direction of B1929+10, an apparent correlation between TSAS and interstellar clouds inside the warm Local Bubble (LB) indicates that TSAS may be tracing the fragmentation of the LB wall via hydrodynamic instabilities. While similar fragmentation events occur frequently throughout the ISM, the warm medium surrounding these cold cloudlets induces a natural selection effect wherein small TSAS clouds evaporate quickly and are rare, while large clouds survive longer and become a general property of the ISM.

  20. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction

    Energy Technology Data Exchange (ETDEWEB)

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz [Islamic Azad University, Department of Chemistry, Science and Research Branch, Tehran (Iran)

    2006-11-15

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 {mu}g g{sup -1} and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. (orig.)

  1. The determination, by atomic-absorption spectrophotometry, of impurities in manganese dioxide

    International Nuclear Information System (INIS)

    This report describes various methods for the determination of impurities in electrolytic manganese dioxide by atomic-absorption spectrophotometry (AAS). The sample is dissolved in a mixture of acids, any residue being ignited and retreated with acid. Several AAS methods were applied so that the analysis required to meet the specifications could be attained. These involved conventional flame AAS, AAS with electrothermal atomization (ETA), hydride generation coupled with AAS, and cold-vapour AAS. Of the elements examined, copper, iron, zinc, and lead can be determined direct with confidence with or without corrections based on recoveries obtained from spiked solutions. Nickel can be determined direct by use of the method of standard additions, and copper, nickel, and lead by ETA with the method of standard additions. Arsenic and antimony are determined by hydride generation coupled with AAS, and mercury by cold-vapour AAS. The precision of analysis (relative standard deviation) is generally less than 0,050. Values were obtained for aluminium, molybdenum, magnesium, sodium, copper, chromium, and cadmium, but the accuracy of these determinations has not been fully established

  2. Determination of tellurium in indium antimonide semiconductor material by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Shiue, M Y; Sun, Y C; Yang, M H

    2001-08-01

    A method for the determination of the dopant concentration of tellurium in dissolved indium antimonide semiconductor material by electrothermal atomic absorption spectrometry (ETAAS) was developed. Efforts were made to investigate the optimal conditions of the furnace heating program and the effect of palladium modifier on the variation of tellurium and the background absorbance. According to the results obtained, the presence of palladium chemical modifier in the analysis of indium antimonide allowed the successful retention of tellurium in the graphite tube, and the optimum mass of palladium modifier was found to be dependent on the sample matrix concentration. The absorbance profile of tellurium and the background level were significantly improved when a pyrolysis temperature of 1100 degrees C and an atomization temperature of 2200 degrees C were employed in the optimized heating program. With the use of this method, a detection limit of 0.8 microg g(-1) tellurium in indium antimonide could be achieved. The applicability of the proposed method was evaluated by comparison with two independent methods, i.e. slurry sampling-ETAAS and ICP-MS. From the good agreement between the results, it was demonstrated that the proposed method is suitable for the determination of typical dopant concentrations of tellurium in indium antimonide. PMID:11534624

  3. Determination of cadmium, cobalt, manganese, copper, nickel, and chromium in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A procedure is developed for the direct determination of Cd, Co, Cr, Cu, Mn, and Ni in concentrated solutions of calcium chloride by electrothermal atomic absorption spectrometry. Ascorbic and oxalic acids and magnesium nitrate were examined as chemical modifiers. Oxalic acid was found to be the best modifier. Although an atomic absorption spectrometer with a background correction system of relatively low efficiency (deuterium lamp) was used, elements under study can be reliably determined in the presence of oxalic acid at concentrations of calcium chloride in the solution up to 6%. Because cadmium is evaporated before the major part of the given matrix, it can be determined without modifier

  4. Optimization of conditions for the determination of Eu, Gd and Sm by atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES)

    International Nuclear Information System (INIS)

    The possibilities of the determination of Sm, Eu and Gd by atomic absorption and emission spectrometry were investigated. Measurement parameters on a Varian atomic absorption spectrometer were optimized (the height of the measurement above the nozzle of the burner, stoichiometry of the dinitrogen oxide-acetylene flame by statistical evaluation of the signals). The following optimal conditions were found for the Sm, Eu and Gd determinations: Samarium - measurement under the emission arrangement at 476.1 nm wavelength, slit width 0.05 nm, in reduction flame close to the outlet slit of the flame (at the lowest part of the flame). Europium - measurement under the absorption arrangement at 459.4 nm wavelength, slit width 1 nm, in reduction flame at the lowest part of the flame. Gadolinium - measurement under the emission arrangement at 461.7 nm wavelength, slit width 0.05 nm, at the lowest part of the flame. (author). 2 figs., 3 tabs., 2 refs

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

    Science.gov (United States)

    Salih, Bekir; Celikbiçak, Omür; Döker, Serhat; Doğan, Mehmet

    2007-03-28

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using (60)Co gamma source in the ternary mixture of NHMMA-ATU-H(2)O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L(-1) of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels. PMID:17386783

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

    International Nuclear Information System (INIS)

    Poly(N-(hydroxymethyl)methacrylamide)-1-allyl-2-thiourea) hydrogels, poly(NHMMA-ATU), were synthesized by gamma radiation using 60Co γ source in the ternary mixture of NHMMA-ATU-H2O. These hydrogels were used for the specific gold, silver, platinum and palladium recovery, pre-concentration and matrix elimination from the solutions containing trace amounts of precious metal ions. Elimination of inorganic matrices such as different transition and heavy metal ions, and anions was performed by adjusting the solution pH to 0.5 that was the selective adsorption pH of the precious metal ions. Desorption of the precious metal ions was performed by using 0.8 M thiourea in 3 M HCl as the most efficient desorbing agent with recovery values more than 95%. In the desorption medium, thiourea effect on the atomic signal was eliminated by selecting proper pyrolysis and atomization temperatures for all precious metal ions. Precision and the accuracy of the results were improved in the graphite furnace-atomic absorption spectrometer (GFAAS) measurements by applying the developed matrix elimination method performing the adsorption at pH 0.5. Pre-concentration factors of the studied precious metal ions were found to be at least 1000-fold. Detection limits of the precious metal ions were found to be less than 10 ng L-1 of the all studied precious metal ions by using the proposed pre-concentration method. Determination of trace levels of the precious metals in the sea-water, anode slime, geological samples and photographic fixer solutions were performed using GFAAS clearly after applying the adsorption-desorption cycle onto the poly(NHMMA-UTU) hydrogels

  7. Atomic Transition Frequencies, Isotope Shifts, and Sensitivity to Variation of the Fine Structure Constant for Studies of Quasar Absorption Spectra

    Science.gov (United States)

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.; King, J. A.; Kozlov, M. G.; Murphy, M. T.; Webb, J. K.

    Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, α = {e}2/hslash c , could be detected via shifts in the frequencies of atomic transitions in quasar absorption systems. Recent studies using 140 absorption systems from the Keck telescope and 153 from the Very Large Telescope, suggest that α varies spatially (61). That is, in one direction on the sky α seems to have been smaller at the time of absorption, while in the opposite direction it seems to have been larger.

  8. Spectroscopy of 1S0- 3P1 transition of magnesium atom in an external absorption cell

    Science.gov (United States)

    Bagayev, S. N.; Baraulya, V. I.; Bonert, A. E.; Goncharov, A. N.; Seydaliev, M. R.

    2001-09-01

    The results of saturated absorption spectroscopy of the intercombination 1S0- 3P1 transition of magnesium atoms at 457 nm in an external absorption cell are presented. A laser system based on a Ti:Sa laser with frequency doubling in a LBO nonlinear crystal was used in these experiments. Saturated absorption resonances of magnesium in an external cell at the 1S0- 3P1 transition have been obtained for the first time. Pressure broadening of resonances equal to 12.5±1.5 kHz/mTorr has been measured.

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

    International Nuclear Information System (INIS)

    The introduction of pump-probe techniques to the field of x-ray absorption spectroscopy (XAS) has allowed the monitoring of both structural and electronic dynamics of disordered systems in the condensed phase with unprecedented accuracy, both in time and in space. We present results on the electronically excited high-spin state structure of an Fe(II) molecular species, [FeII(bpy)3]2+, in aqueous solution, resolving the Fe-N bond distance elongation as 0.2 A. In addition an analysis technique using the reduced χ2 goodness of fit between FEFF EXAFS simulations and the experimental transient absorption signal in energy space has been successfully tested as a function of excited state population and chemical shift, demonstrating its applicability in situations where the fractional excited state population cannot be determined through other measurements. Finally by using a novel ultrafast hard x-ray 'slicing' source the question of how the molecule relaxes after optical excitation has been successfully resolved using femtosecond XANES.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-11-15

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

  11. Absorption-amplification response with or without spontaneously generated coherence effect in a four-level atomic system

    Institute of Scientific and Technical Information of China (English)

    李家华; 杨文星; 彭菊村

    2004-01-01

    We discuss and analyze the absorption properties of a weak probe field in a typical four-level atomic system in the presence of a spontaneously generated coherence (SGC) term. The influences of the SGC and a coherent pump field on the probe absorption-amplification are investigated. The results show that the absorption of such a weak probe field can be dramatically enhanced due to the SGC effect. At the same time, the probe-absorption profile exhibits a two-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adjusting the coherent pump field intensity in the absence of the SGC effect.

  12. Absorption-Amplification Response with or Without Spontaneously Generated Coherence in a Coherent Four-Level Atomic Medium

    Institute of Scientific and Technical Information of China (English)

    LI Jia-Hua; YANG Wen-Xing; PENG Ju-Cun

    2004-01-01

    We discuss and analyze the absorption-amplification properties of a weak probe field in a typical four-level atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. Theinfluences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification)are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced dueto the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibitsthe double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On thecontrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved byadjusting the coherent pump field intensity in the absence of the spontaneously generated coherence.

  13. Absorption-Amplification Response with or Without Spontaneously Generated Coherence in a Coherent Four-Level Atomic Medium

    Institute of Scientific and Technical Information of China (English)

    LIJia-Hua; YANGWen-Xing; PENGJu-Cun

    2004-01-01

    We discuss and analyze the absorption-amplification properties of a weak probe field in a typical fourlevel atomic system in the presence of an additional coherence term, the spontaneously generated coherence term. The influences of the spontaneously generated coherence and a coherent pump field on the probe absorption (amplification) are investigated in detail. We show that the absorption of such a weak probe field can be dramatically enhanced due to the presence of the spontaneously generated coherence. At the same time, the probe-absorption profile exhibits the double-peak structure and the probe-absorption peak gradually decreases as the pump intensity increases. On the contrary, the amplification of such a weak probe field near the line center of the probe transition can be achieved by adiusting the coherent Dump field intensity in the absence of the spontaneously generated coherence.

  14. Scattering of low-energy electrons by excited sodium atoms using a photon and electron atomic beam recoil technique

    International Nuclear Information System (INIS)

    A new method for measuring cross sections for the scattering of electrons by laser-excited atoms is described. It is a generalization of the atomic-beam recoil technique, taking advantage of the recoil of atoms during resonant photon interactions to spatially separate excited from nonexcited atoms. A preliminary value for the total cross section for the scattering of electrons by the 32P3/2(m/sub F/=3) state of sodium at 4.4 eV is presented

  15. The use of an in vitro technique to predict the absorption of dietary radiocaesium by sheep

    International Nuclear Information System (INIS)

    The validity of an in vitro extraction technique to predict the availability for absorption of radiocaesium in the sheep gut has been assessed. The technique (a 2-h extraction with caesium chloride) was found to be valid for sources with a low availability for transfer across the gut, but inappropriate for ionic radiocaesium or radiocaesium incorporated internally within herbage. For such radiocaesium sources, which have a high in vitro availability, no correlation was found between in vitro extraction and true absorption measurements. A true absorption value of 0.80 is recommended for these sources, although values for individual sheep in the range 0.60 to 1.00 should be expected. (orig.)

  16. Simultaneous determination of cadmium and lead in wine by electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Freschi, Gian P. G.; Dakuzaku, Carolina S.; de Moraes, Mercedes; Nóbrega, Joaquim A.; Gomes Neto, José A.

    2001-10-01

    A method has been developed for the direct simultaneous determination of Cd and Pb in white and red wine by electrothermal atomic absorption spectrometry (ET-AAS) using a transversely heated graphite tube atomizer (THGA) with longitudinal Zeeman-effect background correction. The thermal behavior of both analytes during pyrolysis and atomization stages were investigated in 0.028 mol l -1 HNO 3 and in 1+1 v/v diluted wine using mixtures of Pd(NO 3) 2+Mg(NO 3) 2 and NH 4H 2PO 4+Mg(NO 3) 2 as chemical modifiers. With 5 μg Pd+3 μg Mg as the modifiers and a two-step pyrolysis (10 s at 400°C and 10 s at 600°C), the formation of carbonaceous residues inside the atomizer was avoided. For 20 μl of sample (wine+0.056 mol l -1 HNO 3, 1+1, v/v) dispensed into the graphite tube, analytical curves in the 0.10-1.0 μg l -1 Cd and 5.0-50 μg l -1 Pb ranges were established. The characteristic mass was approximately 0.6 pg for Cd and 33 pg for Pb, and the lifetime of the tube was approximately 400 firings. The limits of detection (LOD) based on integrated absorbance (0.03 μg l -1 for Cd, 0.8 μg l -1 for Pb) exceeded the requirements of Brazilian Food Regulations (decree #55871 from Health Department), which establish the maximum permissible level for Cd at 200 μg l -1 and for Pb at 500 μg l -1. The relative standard deviations ( n=12) were typically <8% for Cd and <6% for Pb. The recoveries of Cd and Pb added to wine samples varied from 88 to 107% and 93 to 103%, respectively. The accuracy of the direct determination of Cd and Pb was checked for 10 table wines by comparing the results with those obtained for digested wine using single-element ET-AAS, which were in agreement at the 95% confidence level.

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

    Science.gov (United States)

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

    2006-02-01

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

  18. 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.

  19. Ozone measurement techniques: Traditional versus chamber absorption methods with ultraviolet led as

    International Nuclear Information System (INIS)

    This article describes the traditional techniques for measuring ozone in the lower atmosphere, emphasizing the absorption chamber method with UV LEO diode as a light source for high performance; Ends with an analysis of the advantages and disadvantages of each method.

  20. Autler-Townes doublet in the absorption spectra for the transition between excited states of cold cesium atoms

    Institute of Scientific and Technical Information of China (English)

    Liang Qiang-Bing; Yang Bao-Dong; Yang Jian-Feng; Zhang Tian-Cai; Wang Jun-Min

    2010-01-01

    Autler-Townes splitting in absorption spectra of the excited states 6 2P3/2 - 82S1/2 of cold cesium atoms confined in a magneto-optical trap has been observed.Experimental data of the Autler-Townes splitting fit well to the dressedatom theory,by which the fact of the cold atoms dressed by cooling/trapping laser beams is revealed.The results of the theoretical fitting with experiment not only told us the effective Rabi frequency cold atoms experienced,but also could be used for measuring the probability amplitudes of the dressed states.

  1. SPECIATION OF SELENIUM(IV) AND SELENIUM(VI) USING COUPLED ION CHROMATOGRAPHY: HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY

    Science.gov (United States)

    A simple method was developed to speciate inorganic selenium in the microgram per liter range using coupled ion chromatography-hydride generation atomic absorption spectrometry. Because of the differences in toxicity and adsorption behavior, determination of the redox states selenite, Se(IV), and s...

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

    Science.gov (United States)

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

    Engberg, Å

    1973-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

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

    Science.gov (United States)

    Campbell, W.L.

    1981-01-01

    False readings, apparently caused by the presence of high concentrations of manganese dioxide, have been observed in our current flame atomic-absorption procedure for the determination of gold. After a hydrobromic acid (HBr)-bromine (Br2) leach, simply heating the sample to boiling to remove excess Br2 prior to extraction with methyl-isobutyl-ketone (MIBK) eliminates these false readings. ?? 1981.

  6. On the multiphoton emission during U.V. and X-ray absorption by atoms in intense laser fields

    International Nuclear Information System (INIS)

    A discussion of the u.v. and x-ray absorption cross section by a hydrogen atom in the presence of an intense i.r. laser field is presented, taking into account the influence of laser field on the electronic states. (Author)

  7. Semiclassical calculations on one-, two-, three-, and four- photon absorption in truncated models of the hydrogen atom

    International Nuclear Information System (INIS)

    The results of semiclassical calculations on one-, two-, three-, and four-photon absorption in truncated models of the hydrogen atom are presented. The temporal behavior near ''resonance'' is confirmed to be Rabi-like, with a transition probability given by P (t) = ]γ2/[(ω0/N + delta - ω)2 + γ2

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

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Ekelund, J.

    1989-01-01

    -effect background corrected graphite furnace atomic absorption spectrometry. A furnace ashing step at 1100 °C was necessary in order to obtain a total recovery of selenium when present in the organic form. Palladium nitrate-magnesium nitrate was used as a matrix modifier. Independent methods were used to determine...

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-01-01

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

  11. Interference Effects on the Probe Absorption in a Driven Three-Level Atomic System by a Coherent Pumping Field

    International Nuclear Information System (INIS)

    In this work the quantum interference effect on the weak probe absorption in a closed three-level V atomic system driven by a coherent driving field is shown to result from the twoquantum processes, constructive for the amplification channels and destructive for the absorption channel. A fourth state in the atom is coupled incoherently to the V system and acts as both an incoherent pumping reservoir and as a stationary, final state in perturbation theory. The application refers to Be-like carbon ions where non-linear pump process of the 1s22s5s(1Se) - 1s22p5s(1P0) transition is combined with the absorption or emission of a single probe photon corresponding to 1s22s5s(1Se) -1s22p7s(1P0) transition. The system is analyzed within the Rmatrix Floquet theory and codes results. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-01

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

  13. Direct analysis of silica by means of solid sampling graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    This paper reports on the use of solid sampling-graphite furnace atomic absorption spectrometry for the direct analysis of synthetic amorphous silica. In particular, determination of hazardous elements such As, Cd, Cr, Cu, Pb and Sb is investigated, as required by regulations of the food industry. The conclusion of the work is that, after proper optimization of the working conditions, paying particular attention to the atomization temperature and the use of proper modifiers (graphite powder, HNO3 or Pd), it is possible to develop suitable procedures that rely on the use of aqueous standard solutions to construct the calibration curves for all the elements investigated. The proposed method shows important benefits for the cost-effective analysis of such difficult samples in routine labs, permitting fast screening of those elements that are very rarely present in this type of sample, but also accurate quantification of those often found, while offering low limits of detection (always below 0.1 mg g−1) that comply well with legal requirements, and precision levels that are fit for the purpose (approx. 6–9% R.S.D.). - Highlights: ► Solid sampling GFAAS is investigated for the direct analysis of silica samples; ► a fast and simple methodology with aqueous standards for calibration is proposed; ► this method permits accurate determination of As, Cd, Cr, Cu, Pb and Sb in the samples of interest; ► LODs below 100 ng g−1 and precision values in the 6–10% RSD range are achieved.

  14. Sandwich concept: enhancement for direct absorption measurements by laser-induced deflection (LID) technique

    Science.gov (United States)

    Mühlig, Ch.; Bublitz, S.; Paa, W.

    2012-11-01

    The new sandwich concept for absolute photo-thermal absorption measurements using the laser induced deflection (LID) technique is introduced and tested in comparison to the standard LID concept. The sandwich concept's idea is the decoupling of the optical materials for the pump and probe beams by placing a sample of investigation in between two optical (sandwich) plates. The pump beam is guided through the sample whereas the probe beams are deflected within the sandwich plates by the thermal lens that is generated by heat transfer from the irradiated sample. Electrical simulation and laser experiments reveal that using appropriate optical materials for the sandwich plates, the absorption detection limit for photo-thermally insensitive materials can be lowered by up to two orders of magnitude. Another advantage of the sandwich concept, the shrinking of the currently required minimum sample size, was used to investigate the laser induced absorption change in a Nd:YVO4 crystal at 1030nm. It was found that the absorption in Nd:YVO4 lowers due to the laser irradiation but partially recovers during irradiation breaks. Furthermore, absorption spectroscopy has been performed at two LBO crystals in the wavelength range 410...600nm to study the absorption structure around the SHG wavelengths of common high power lasers based on Neodymium doped laser crystals.

  15. Reflection absorption infrared spectroscopy during atomic layer deposition of HfO2 films from tetrakis(ethylmethylamido)hafnium and water

    International Nuclear Information System (INIS)

    Tetrakis(ethylmethylamido)hafnium and water are commonly used precursors for atomic layer deposition of HfO2. Using reflection absorption infrared spectroscopy with a buried-metal-layer substrate, we probe surface species present during typical deposition conditions. We observe evidence for thermal decomposition of alkylamido ligands at 320 deg. C. Additionally, we find that complete saturation of the SiO2 substrate occurs in the first cycle at ∼100 deg. C whereas incomplete coverage is apparent even after many cycles at higher temperatures. The use of this technique as an in situ diagnostic useful for process optimization is demonstrated.

  16. Reflection absorption infrared spectroscopy during atomic layer deposition of HfO{sub 2} films from tetrakis(ethylmethylamido)hafnium and water

    Energy Technology Data Exchange (ETDEWEB)

    Sperling, Brent A., E-mail: brent.sperling@nist.gov [Process Measurements Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8360 (United States); Kimes, William A.; Maslar, James E. [Process Measurements Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8360 (United States)

    2010-06-01

    Tetrakis(ethylmethylamido)hafnium and water are commonly used precursors for atomic layer deposition of HfO{sub 2}. Using reflection absorption infrared spectroscopy with a buried-metal-layer substrate, we probe surface species present during typical deposition conditions. We observe evidence for thermal decomposition of alkylamido ligands at 320 deg. C. Additionally, we find that complete saturation of the SiO{sub 2} substrate occurs in the first cycle at {approx}100 deg. C whereas incomplete coverage is apparent even after many cycles at higher temperatures. The use of this technique as an in situ diagnostic useful for process optimization is demonstrated.

  17. Determination of β-lactam Antibiotics in Pharmaceutical Preparations by Uv-visible Spectrophotometry Atomic Absorption and High Performance Liquid Chromatography

    OpenAIRE

    *A. J. Abdulghani; 1H. H. Jasim; HASSAN, A.S.

    2012-01-01

    The determination amoxicillin, ampicillin and cephalexin was studied by complexation of the antibiotics with Au(III) and Hg(II) ions in bulk and pharmaceutical preparations using uv-visible spectrophotometry, atomic absorption, and HPLC techniques. Optimum conditions for complex formation were fixed at pH 4 and (2-4) for Au(III) and Hg(II)complexes respectively, heating temperature at (60 °C) and heating time for (10 minute). All complexes were extracted from aqueous solution with benzyl alco...

  18. Collisions of metastable Ne*, He* atoms with ground-state He, Ne atoms studied by atomic beam and laser techniques

    International Nuclear Information System (INIS)

    A crossed nozzle-beam experiment is used to investigate thermal energy collisions: Ne* (2p53s, 3P0,2) + He(1s2, 1S0), almost purely elastic, and He*(1s2s, 1,3S + Ne(2p6, 1S0), in which inelastic excitation transfers occur. State and velocity selection of the scattered Ne* atoms is performed using a tunable cw dye laser frequency locked on a definite Zeeman component of the transition 1s5 → 2p6 (λ = 614.3 nm) of 20Ne or 22Ne. In the purely elastic case, this technique allows the selection of one of the two final velocities, and then an unambiguous transformation of the differential cross section at 62 meV tallies on accords with a calculation using a single effective potential. In He* on Ne collisions, the main inelastic processes are endothermic excitation transfers from He*(21S). Experimental results obtained at different energies (62, 95, 109, 124 meV) show that the transfers essentially result in levels 3s and 4d of Ne. (orig.)

  19. X-ray phase imaging using a Gd-based absorption grating fabricated by imprinting technique

    Science.gov (United States)

    Yashiro, Wataru; Kato, Kosuke; Sadeghilaridjani, Maryam; Momose, Atsushi; Shinohara, Takenao; Kato, Hidemi

    2016-04-01

    A high-aspect-ratio absorption grating with a pitch of several µm is a key component of X-ray grating interferometery, which is an X-ray phase imaging technique that allows for highly sensitive X-ray imaging with a compact laboratory X-ray source. Here, we report that X-ray phase imaging was successfully performed at 15 keV by using a 23 ± 1-µm-height, 9-µm-pitch absorption grating (10 × 10 mm2) based on Gd (Gd60Cu25Al15) fabricated by a metallic glass imprinting technique. The imprinting technique is cost-efficient and has a high-production rate, and will be widely used for fabricating gratings not only for X-rays but also neutrons in the near future.

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

    International Nuclear Information System (INIS)

    The absolute number densities of helium atoms in the 2s 3S1 metastable state were determined in four plasma-based ambient desorption/ionization sources by atomic absorption spectroscopy. The plasmas included a high-frequency dielectric barrier discharge (HF-DBD), a low temperature plasma (LTP), and two atmospheric-pressure glow discharges, one with AC excitation and the other with DC excitation. Peak densities in the luminous plumes downstream from the discharge capillaries of the HF-DBD and the LTP were 1.39 × 1012 cm−3 and 0.011 × 1012 cm−3, respectively. Neither glow discharge produced a visible afterglow, and no metastable atoms were detected downstream from the capillary exits. However, densities of 0.58 × 1012 cm−3 and 0.97 × 1012 cm−3 were measured in the interelectrode regions of the AC and DC glow discharges, respectively. Time-resolved measurements of metastable atom densities revealed significant random variations in the timing of pulsed absorption signals with respect to the voltage waveforms applied to the discharges. - Highlights: • We determine He metastable number densities for four plasma types • The highest number densities were observed in a dielectric barrier discharge • No helium metastable atoms were observed downstream from the exits of glow discharges

  1. 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

  2. Determination of nickel in active pharmaceutical ingredients by electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Bubnič, Zoran; Urleb, Uroš; Kreft, Katjuša; Veber, Marjan

    2010-03-01

    An electrothermal atomic absorption spectrometric procedure for the determination of nickel in active pharmaceutical ingredients was developed. Since the recoveries of nickel by the direct dissolution of samples in diluted nitric acid were low and caused errors in the determination of Ni in pharmaceutical samples, different approaches for sample pre-treatment were examined. It was found that the microwave digestion was the most suitable way for sample preparation. Various combinations of digestion agents and different microwave conditions were tested. The combination of nitric acid and hydrogen peroxide was found to be the most appropriate. The validity of the method was evaluated by recovery studies of spiked samples and by the comparison of the results obtained by inductively coupled plasma mass spectrometry (ICP-MS). The recovery ranged from 87.5 to 104.0% and a good agreement was achieved between both methods. The detection limit and the limit of quantification were 0.6 and 2.1 µg g-1 respectively. The precision of the method was confirmed by the determination of Ni in the spiked samples and was below 4%, expressed in terms of a relative standard deviation. The method was applied to the determination of nickel in production samples of active pharmaceutical ingredients and intermediates. PMID:24061653

  3. Studies on atomic absorption spectrophotometric analysis of hexavalent chromium in waste water by solvent extraction

    International Nuclear Information System (INIS)

    Atomic absorption spectrophotometric(AAS) determination of hexavalent chromium [Cr(VI)] in a waste water was studied. Cr(VI) was extracted with p-xylene from the wastewater, in the way of ion pair formation with anion exchanger aliquat-336(tri-caprylmethyl ammonium chloride). 100ml waste water, after organic materials were extracted out with toluene, was acidified with conc. HCl adjusting the medium to pH 0.5 and 20ml of p-xylene containing 0.01M aliguat-336 was used to extract Cr(VI) from the acidified solution. The absorbance of chromium was measured with air-acetylene flame at 357.9nm. Standard addition method was used in the determining concentration of Cr(VI) extracted. No interference has been found in the extraction of Cr(VI) by the Al(III), Fe(III) and Cr(III) ion presented. However, Fe(II) decreased the absorbance of Cr(VI), due to the fact Fe(II) reduces Cr(VI) to Cr(III). The contained organic material was removed prior to extracting process, since it may reduced the absorbance of Cr(VI). The recovery of added Cr(VI) was over 96%, which seems to be promising and the relative standard deviation was 3.95%. (Author)

  4. Determination of chromium and molybdenum in medical foods by graphite furnace atomic absorption spectrophotometry.

    Science.gov (United States)

    Phifer, E C

    1995-01-01

    Graphite furnace atomic absorption spectrophotometry was used to determine chromium and molybdenum in 7 medical foods from 5 manufacturers. Linear standard curves were obtained for both elements for concentrations between 5 and 25 ng/mL. Detection limits were 0.24 ng/mL for Cr and 0.67 ng/mL for Mo. Characteristic masses were 3.1 and 14.7 pg for Cr and Mo, respectively. No difference was detected between wet and dry ashing methods, and dry ashing was used to complete the study. The method was validated by assaying various National Institute of Standards and Technology standard reference materials. Analysis of these products for Cr and Mo were within certified values. One product was evaluated by this method for reproducibility (n = 5). Relative standard deviations were 6.8 and 4.8% for Cr and Mo, respectively. This product contained 0.31 +/= 0.02 micrograms Cr/g and 0.63 +/- 0.03 micrograms Mo/g. The remaining products contained 0.09-1.28 micrograms Cr/g and 0.07-2.3 micrograms Mo/g. Mean recovery values were 98 +/- 14% (n = 14) for Cr at spike levels of 0.20-1.89 micrograms/g and 102 +/- 24% (n = 10) for Mo at spike levels of 0.30-1.89 micrograms/g. PMID:8664588

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

    International Nuclear Information System (INIS)

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

  6. Iron in Alzheimer's and Control Hippocampi - Moessbauer, Atomic Absorption and ELISA Studies

    International Nuclear Information System (INIS)

    Alzheimer disease is a neurodegenerative process of unknown mechanism taking place in a part of the brain - hippocampus. Oxidative stress and the role of iron in it is one of the suggested mechanisms of cells death. In this study several methods were used to assess iron and iron binding compounds in human hippocampus tissues. Moessbauer spectroscopy was used for identification of the iron binding compound and determination of total iron concentration in 12 control and one Alzheimer disease sample of hippocampus. Moessbauer parameters obtained for all samples suggest that most of the iron is ferritin-like iron. The average concentration of iron determined by Moessbauer spectroscopy in control hippocampus was 45 ± 10 ng/mg wet tissue. The average concentration of iron in 10 Alzheimer disease samples determined by atomic absorption was 66 ± 13 ng/mg wet tissue. The concentration of H and L chains of ferritin in 20 control and 10 AD hippocampi was assessed with enzyme-linked immuno-absorbent assay. The concentration of H and L ferritin was higher in Alzheimer disease compared to control (19.36 ± 1.51 vs. 5.84 ± 0.55 ng/μg protein for H, and 1.39 ± 0.25 vs. 0.55 ± 0.10 for L). This 3-fold increase of the concentration of ferritin is accompanied by a small increase of the total iron concentration. (authors)

  7. Use of Atomic Absorption Spectrometry in Assessment of Biomonitor Plants for Lead, Cadmium and Copper Pollution

    Institute of Scientific and Technical Information of China (English)

    Gokce Kaya; Mehmet Yaman

    2012-01-01

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

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

    Science.gov (United States)

    Gokce, Kaya; Mehmet, Yaman

    2012-01-01

    Eleven plant species were collected from the vicinity of lead-battery plant in the city of Gaziantep, Turkey. Lead, cadmium and copper concentrations in the soil and leaves of plants were determined by atomic absorption spectrometry. Lead, Cd and Cu concentrations in the soil samples taken from battery area were found to be in the ranges of 304-602, 0.4-0.44 and 31-37 mg x kg(-1), respectively. Significantly increased lead concentration up to 2 750 mg x kg(-1) was found in the leaves of Eleagnus angustifolia L. plant. The lead concentrations in the other plant leaves taken from 50 m around battery factory followed the order Ailanthus altissima > Morus sp. > Juglans regia L. > Ficus carica L. > Cydonia oblonga Miller > Prunus x domestica L. The plants, Populus nigra L. , Eleagnus angustifolia L. and Salix sp. were found useful for Cd, and the plant, Eleagnus angusti folia L. for Pb, to be considered as potential biomonitor. Especially, leaves of trees and plants taken from the distance of 50 m from battery plant have relatively higher Pb concentrations. Therefore, people who and animals which live in this area and benefit from these soil and plants have vital risks. PMID:22497165

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

    Directory of Open Access Journals (Sweden)

    Hana Zelinková

    2012-01-01

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

  10. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer.

    Science.gov (United States)

    Kazi, T G; Jalbani, N; Arain, M B; Jamali, M K; Afridi, H I; Sarfraz, R A; Shah, A Q

    2009-04-15

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy. PMID:18657905

  11. Toxic metals distribution in different components of Pakistani and imported cigarettes by electrothermal atomic absorption spectrometer

    International Nuclear Information System (INIS)

    It was extensively investigated that a significant flux of toxic metals, along with other toxins, reaches the lungs through smoking. In present study toxic metals (TMs) (Al, Cd, Ni and Pb) were determined in different components of Pakistani local branded and imported cigarettes, including filler tobacco (FT), filter (before and after normal smoking by a single volunteer) and ash by electrothermal atomic absorption spectrometer (ETAAS). Microwave-assisted digestion method was employed. The validity and accuracy of methodology were checked by using certified sample of Virginia tobacco leaves (ICHTJ-cta-VTL-2). The percentages (%) of TMs in different components of cigarette were calculated with respect to their total contents in FT of all branded cigarettes before smoking, while smoke concentration has been calculated by subtracting the filter and ash contents from the filler tobacco content of each branded cigarette. The highest percentage (%) of Al was observed in ash of all cigarettes, with range 97.3-99.0%, while in the case of Cd, a reverse behaviour was observed, as a range of 15.0-31.3% of total contents were left in the ash of all branded cigarettes understudy

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

    Directory of Open Access Journals (Sweden)

    Cristiana Radulescu

    2011-05-01

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

  13. Evaluation for the method for the determination of impurities in uranium products by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Objective: To establish a reliable method for the determination of Al, Ca, Cd, Co, Cr, Cu, Fe, Mn, Mo, Mg, Ni, Pb, V and Zn as impurities in a uranium oxide (U3 O8). Methodology: The sample, generally a solid or a powder, is solubilized by acid digestion with concentrated nitric acid, carrying to dryness for the recover with 6 N Nitric Acid to extract the uranium matrix, try butyl phosphate to 30 % in carbon tetrachloride (C Cl4), the aqueous phase containing the impurities is heat up with perchloric acid (HClO4) in order to eliminate the remainder organic solvent. A Perking Elmer Atomic Absorption spectrophotometer is used for the analysis of the samples which were read for 5 times and the average is reported as final result. The method is considered as valid since it comply with linearity in the concentration for each one of the elements. The accuracy of the method is check with the repeatability of the results. For the evaluation of the accuracy, reference certified standards are used. (Author)

  14. 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.

  15. Speciation Analysis of Serum Copper by Ultrafiltration Com-bined with Graphite Furnace Atomic Absorption Spectrometry

    Institute of Scientific and Technical Information of China (English)

    WANG Zhi-Hua; MA Hui-Min; MA Quan-Li; LIANG Shu-Chuan

    2001-01-01

    UItrafiltration combined with graphite furnace atomic absorp-tion spectrometry(GFAAS)was used to study protein binding and speciation of copper in human serum..UItrafiltration was carried out using a cell unit ultrafiltration membraoes having a nominal cut-off of 10,000Dalton.The effects of var-ious experimental factors including the kind and concentration of electrolyte,sample storge,pH,pressure and the precon-ditioning of the membranes on the speciation analysis of serum copper by ultrafiltration were examined.It was observed that 4.5±2.3% of the total copper in serum was ultrafiltrable and this value did not seem to be influenced by the total serum ele-mental concentration,the PH (6.5——10) adn the pressure(≤1.5kg/cm2).the preconditioning of the ultrafiltration system with 0.1mol/L calcium nitrate can overcome the adsorption loss of copper effectively,and the addition of tris-HCI sohtion (pH 7.4)to serum accelerates the ultrafiltration.The present method was proved to be suitable for speciation analysis for its simplicity,rapidity,small sample reuqirement and easy con-trol.The results obtained with the method are accurate and reliable.

  16. Analysis of the release characteristics of cu-treated antimicrobial implant surfaces using atomic absorption spectrometry.

    Science.gov (United States)

    Zietz, Carmen; Fritsche, Andreas; Finke, Birgit; Stranak, Vitezslav; Haenle, Maximilian; Hippler, Rainer; Mittelmeier, Wolfram; Bader, Rainer

    2012-01-01

    New developments of antimicrobial implant surfaces doped with copper (Cu) ions may minimize the risk of implant-associated infections. However, experimental evaluation of the Cu release is influenced by various test parameters. The aim of our study was to evaluate the Cu release characteristics in vitro according to the storage fluid and surface roughness. Plasma immersion ion implantation of Cu (Cu-PIII) and pulsed magnetron sputtering process of a titanium copper film (Ti-Cu) were applied to titanium alloy (Ti6Al4V) samples with different surface finishing of the implant material (polished, hydroxyapatite and corundum blasted). The samples were submersed into either double-distilled water, human serum, or cell culture medium. Subsequently, the Cu concentration in the supernatant was measured using atomic absorption spectrometry. The test fluid as well as the surface roughness can alter the Cu release significantly, whereby the highest Cu release was determined for samples with corundum-blasted surfaces stored in cell medium. PMID:22162672

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

    Science.gov (United States)

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

    1990-01-01

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

  18. Determination of lead in croatian wines by graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A method has been developed for direct determination of lead in wine by graphite furnace atomic absorption spectrometry (GFAAS) with Zeeman-effect background correction. The thermal behaviour of Pb during pyrolysis and atomisation stages was investigated without matrix modifier and in the presence of Pd(NO3)2, Pd(NO3)2 + Mg(NO3)2 x 6H2O, and NH4H2PO4 + Mg(NO3)2 x 6H2O as matrix modifiers. A simple 1:1 dilution of wine samples with Pd(NO3)2 as a matrix modifier proved optimal for accurate determination of Pb in wine. Mean recoveries were 106 % for red and 114 % for white wine, and the detection limit was 3 μg L-1. Within-run precision of measurements for red and white wine was 2.1 % and 1.8 %, respectively. The proposed method was applied for analysis of 23 Croatian wines. Median Pb concentrations were 33 μg L-1, range (16 to 49) μg L-1 in commercially available wines and 46 μg L-1, range (14 to 559) μg L-1 in home-made wines. There were no statistically significant differences (P<0.05) in Pb concentration between commercial and home-made wines or between red and white wines. (authors)

  19. Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

    2016-01-01

    A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

  20. 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

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

    Science.gov (United States)

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

    2015-08-01

    This study reports minerals and trace elements quantification in raw caprine milk of Beetal breed, reared in Northern India and their feed, fodder & water using flame atomic absorption spectrophotometry and flame photometry. The mineral and trace elements' concentration in the milk was in the order: K > Ca > Na > Fe > Zn > Cu. The results showed that minerals concentration in caprine milk was lesser than reference values. But trace elements concentration (Fe and Zn) was higher than reference values. Multivariate statistical techniques, viz., Pearsons' correlation, Cluster analysis (CA) and Principal component analysis (PCA) were applied to analyze the interdependences within studied variables in caprine milk. Significantly positive correlations were observed between Fe - Zn, Zn - K, Ca - Na and Ca - pH. The results of correlation matrix were further supported by Cluster analysis and Principal component analysis as primary cluster pairs were found for Ca - pH, Ca - Na and Fe - Zn in the raw milk. No correlation was found between mineral & trace elements content of the milk and feed. PMID:26243956

  2. Solid sample graphite furnace atomic absorption spectroscopy for supporting arsenic determination in sediments following a sequential extraction procedure

    International Nuclear Information System (INIS)

    Solid sample graphite furnace atomic absorption spectroscopy (SS-GFAAS) has been proposed since its appearance as a good alternative to wet methods of analysis in many matrices. Here, we examine the use of SS-GFAAS for total and leachable arsenic determination in sediments from distinct origins. Our direct analysis of seven selected sediments was not always free of spectral matrix interference, but the spectroscopic technique gave very good results for (a) direct arsenic measurement in solid residues from a range of leaching processes, (b) total arsenic determination (HNO3 leaching test) and (c) the evaluation of its potential remobilisation (modified BCR three-step sequential extraction scheme). For the optimised instrumental conditions, the analysis limit was 0.44 mg kg-1 and long-term reproducibility was between 10-15%. The sum of leachable arsenic in HNO3 65% and the residual fraction, gave recoveries from 72 to 118% of total arsenic content. These results are a good alternative to other cumbersome wet methods involving HF

  3. Selective determination of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone by atomic-absorption spectrometry with a carbon-tube atomizer.

    Science.gov (United States)

    Kamada, T; Yamamoto, Y

    1977-05-01

    The extraction behaviour of antimony(III) and antimony(V) with ammonium pyrrolidinedithiocarbamate, sodium diethyldithiocarbamate and dithizone in organic solvents has been investigated by means of frameless atomic-absorption spectrophotometry with a carbon-tube atomizer. The selective extraction of antimony(III) and differential determination of antimony(III) and antimony(V) have been developed. With ammonium pyrrolidinedithiocarbamate and methyl isobutyl ketone, when the aqueous phase/solvent volume ratio is 50 ml/10 ml and the injection volume in the carbon tube is 20 mul, the sensitivity for antimony is 0.2 ng/ml for 1% absorption. The relative standard deviations are ca. 2%. Interferences by many metal ions can be prevented by masking with EDTA. The proposed methods have been applied satisfactorily to determination of antimony(III) and antimony(V) in various types of water. PMID:18962096

  4. New techniques for optical absorption measurement of implanted nanoparticles in float glass

    International Nuclear Information System (INIS)

    New techniques are reported for optical absorption and waveguide loss measurement of copper, gold and silver implanted float glass. Implantations were carried out on the tin face of the float glass since this face is an optical waveguide. Specially made triangle shape masks were used during implantation to study the optical loss-implant length relation. Absorption coefficients were extracted as 2.4 and 1 cm-1 for the gold and silver implants at 633 nm, respectively. These values were found to be implant condition dependent. To analyse the shape of nanoparticles a sandwiched structure was used in an optical absorption measurement set-up in which two guiding faces were put in contact. The sandwiched structure places the colloids at the centre of the optical field distribution rather than on the boundary zone. These experiments have revealed that the copper and the gold particles may have non-spherical shapes, whereas for silver, the formation of spherical nanoparticles is more likely

  5. Survey on result promotion of the atomic force technique

    International Nuclear Information System (INIS)

    By change of environment around research and development of atomic force, investigation has been recently executed not only on a theme directing a specific aim, but also on technical development considering some applications to the other field reflected by social needs. Therefore, an effective procedure and program capable of reflecting and promoting results of the atomic fore development to other industrial field were necessary. In this study, methods of evaluation and industrialization on study results of the atomic force were investigated. As a result, in order to promote the study results to other field, it was found to be important that some free reasons and concept engineering to mediate between developing and applying sides were to be present. In addition, it was suggested by some searches that a new atomic industry has a probability to be created by using potential energies such as heat, radiation, pulse, and so on. In this paper, evaluation on industrialization of the atomic force technical resources, and establishment of the industrialization program were described. (G.K.)

  6. Cerium oxide nanoparticles coated by surfactant sodium bis(2-ethylhexyl) sulphosuccinate (AOT): local atomic structures and x-ray absorption spectroscopic studies

    International Nuclear Information System (INIS)

    Cerium oxide nanoparticles coated by sodium bis(2-ethylhexyl) sulphosuccinate (AOT) were prepared by using a microemulsion method. Transmission electron microscopy revealed an average particle size of 2-3 nm. X-ray diffraction showed that the cerium oxide nanoparticles retain the CeF2-type cubic structures like the bulk crystal. The intermediate valence of formally tetravalent compounds had been detected by x-ray-absorption near-edge structure (XANES) spectra of Ce LIII absorption in bulk CeO2 and the cerium oxide nanoparticles. Two well resolved white lines can be assigned to the electron configurations of 4f0L and 4f1L, respectively, where L denotes a ligand hole. At the same time, the cerium oxide nanoparticles also showed the structural features of trivalent compounds, in comparison to the trivalent Ce(NO3)3·6H2O. Four Lorentzian functions and two arctan functions were used to fit the normalized XANES spectra. The extended x-ray-absorption fine-structure (EXAFS) technique was used to probe the local atomic structures around the absorber Ce. The multielectron excitation effect on the EXAFS spectra was eliminated. A core-shell model was used to deduce the near-neighbour structural parameters around cerium. Bulk CeO2 with eight oxygen atoms located at 2.343 A was used as the reference sample to extract the backscattering amplitude and phase shift of the Ce-O bond. One half of the atoms locate at the core part with the CeF2-type cubic structures (eight oxygens at 2.343 A around Ce), the other half of the atoms are amorphous phase located in the shell part (surface of the nanoparticles) with approximately Ce2O3 structural features (averaged seven oxygens at 2.50 A around Ce). (author)

  7. Attosecond transient absorption of argon atoms in the vacuum ultraviolet region: line energy shifts versus coherent population transfer

    Science.gov (United States)

    Cao, Wei; Warrick, Erika R.; Neumark, Daniel M.; Leone, Stephen R.

    2016-01-01

    Using attosecond transient absorption, the dipole response of an argon atom in the vacuum ultraviolet (VUV) region is studied when an external electromagnetic field is present. An isolated attosecond VUV pulse populates Rydberg states lying 15 eV above the argon ground state. A synchronized few-cycle near infrared (NIR) pulse modifies the oscillating dipoles of argon impulsively, leading to alterations in the VUV absorption spectra. As the NIR pulse is delayed with respect to the VUV pulse, multiple features in the absorption profile emerge simultaneously including line broadening, sideband structure, sub-cycle fast modulations, and 5-10 fs slow modulations. These features indicate the coexistence of two general processes of the light-matter interaction: the energy shift of individual atomic levels and coherent population transfer between atomic eigenstates, revealing coherent superpositions. An intuitive formula is derived to treat both effects in a unifying framework, allowing one to identify and quantify the two processes in a single absorption spectrogram.

  8. Determination of a trace amount of cadmium in suspended substances in sea water by atomic absorption spectrophotometry with carbon-tube atomizer

    International Nuclear Information System (INIS)

    Sea water ((4 -- 5)l) was filtered with a 0.45 μm milipore filter and cadmium contained in suspended substances gathered on the filter was dissolved by conc. nitric acid. A sample solution (20 μl) was atomized by passing high electric current through the atomizer. The concentration of cadmium was determined by using of the calibration curves which were made by measuring the absorption peak heights of cadmium at 2288A. Alkali metals which show strong background absorptions near the analytical line of cadmium did not interfere with the determination of cadmium, even in the presence of 100000-fold. This may be due to the difference of volatilities. Background absorptions by substances contained in the milipore filter and by suspended substances were corrected by using of the deuterium lamp. The sensitivity for 1% absorption was 0.2 ppb of cadmium. The coefficient of variations for the repeated analysis of 5 times was found to be within about 6%. (auth.)

  9. Determination of vitamin B12 (cobalamine) absorption by means of a simple double-isotope technique

    International Nuclear Information System (INIS)

    The background, practical instruction and clinical results of a simplified method of determining the absorption of cobalamine (vitamin B12) are presented. The simultaneous administration of 57CO-CN-cobalamine, a non-absorbable marker (51CrCl3), and red carmine tablets enable quantitative assessments of the cobalamine absorption by collection of a small red feaces sample. In contrast to the classical Schilling-test, this vitamin B12 absorption test (B12-ABS-test) or faeces-spot-test is, independent of fasting, flushing dose, renal function and diurnal urinary collection. This is documented in a series of clinical studies. The B12-ABS-test provides accurate and precise results compared to the reference method (whole-body-counting). The Schilling test, on the contrary, gives approximately 50% false low values in a reference group of elderly hospitalized patients. A modification of the B12-ABS-test, has been used to determine the cobalamine absorption in children, and a set of age-related reference intervals have been established, together with quantitative measurements of the cobalamine absorption in children with small bowel diseases. Based on several years of practical experience, we recommend replacement of the Schilling test by this simple double-isotope technique. (author)

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

    International Nuclear Information System (INIS)

    The fecal monitoring technique for measuring the absorption of Mn, Se and Fe was studied in eight piglets using high resolution gamma spectrometry. Four day old piglets were fed a complete liquid diet for five days prior to the administration of an isotope dose (75Se, 54Mn, 59Fe) equilibrated with the milk feeding. 51CrCl3 was used as a fecal marker. Subsequently stool and urine samples were collected daily for 15-21 days. Following counting, the % fecal excretion of the administered dose was calculated. As 0 to 33% of the administered 51CrCl3 was absorbed this fecal marker is inappropriate for piglets. Results indicate that endogenous excretion for each of the isotopes was not constant but decreased exponentially with time. An improved method for calculating the endogenous excretion was therefore developed. This method is based on the pattern of endogenous excretion in comparable piglets injected intravenously with the same isotopes, and on the level of endogenous excretion in the orally fed animals in the post-absorptive phase of excretion. These findings have important implications for the estimation of endogenous excretion in future fecal monitoring absorption studies. Previous results using the latter technique have frequently underestimated true absorption

  11. Sensitivity enhancement of beryllium determination in graphite furnace-atomic absorption spectrometry by use of atomization under pressure

    International Nuclear Information System (INIS)

    Using pressurized atomization both peak height and area sensitivity of beryllium is considerably improved. The enhancement may probably be explained by the fact that the Lorentz broadening and shift is more than compensated for by the lower diffusion rate of atoms with increasing pressures. The alteration of peak shapes and parameters should result in a diminishment of vapor phase interferences with increasing pressure. The relative time resolution of the detection system also improves with increasing pressures, with a consequent improvement of precision and accuracy. In the absorbance domain calibration curves are more linear with pressurized atomization than at atmospheric pressure. (Author)

  12. Equivalent width of copper and potassium resonance lines at 3247.54, 7665 Angst for Voigt profile by atomic absorption measurements

    Energy Technology Data Exchange (ETDEWEB)

    Habib, A.A.M. E-mail: azhabib@yahoo.com

    2004-03-15

    A simple reliable theoretical approach is developed to calculate the equivalent width of copper and potassium resonance lines at 3247.54 and 7665 Angst using atomic absorption techniques. The calculations have been carried out for the two limiting cases of a pure Doppler (Gaussian) and Lorentzian (dispersion) line profiles. The more general case of a Voigt line profile leads to an efficient analytical formula permits a rapid estimate of the equivalent width with sufficient precision. The reliability of the approach has been verified by providing the curves of growth for the given spectral lines to describe the behavior of the equivalent width as the number of absorbing atoms in the ground state is increased. Allowance is made in the analysis for the dependence of the equivalent width for Voigt profile on the damping constant {alpha}, which is a measure of the half width of Lorentz profile relative to the Doppler profile.

  13. Precision of flame atomic absorption measurements of arsenic, cadmium, calcium, copper, iron, magnesium, molybdenum, sodium, and zinc

    International Nuclear Information System (INIS)

    Procedures for evaluating the precision of atomic absorption measurements have been improved and applied to 8 elements. Measurements on a Varian AA-6 spectrophotometer indicate that there are many similarities in the precision characteristics of different elements. For instance, analyte absorption flicker noise limits the measurement precision of most elements at moderate absorbances. The actual value of the measurement precision at a given absorbance and the dependence of measurement precision on absorbance depend upon the calibration curve, the wavelength of analysis, the integration time, and the type of flame employed

  14. Techniques to measure quantum criticality in cold atoms

    International Nuclear Information System (INIS)

    We describe how rescaling experimental data obtained from cold atom density profiles can reveal signatures of quantum criticality. We identify a number of important questions which can be answered by analyzing experimental data in this manner. We show that such experiments can distinguish different universality classes and that the signatures are robust against temperature, noise, and finite system size.

  15. Determination of arsenic and cadmium in crude oil by direct sampling graphite furnace atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Alexandre de; Zmozinski, Ariane Vanessa [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Damin, Isabel Cristina Ferreira [Faculdade Dom Bosco de Porto Alegre, 90520-280, Porto Alegre, RS (Brazil); Silva, Marcia Messias, E-mail: mmsilva@iq.ufrgs.br [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil); Vale, Maria Goreti Rodrigues [Instituto de Quimica, Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970 Porto Alegre, RS (Brazil); Instituto Nacional de Ciencia e Tecnologia do CNPq, INCT de Energia e Ambiente, Universidade Federal da Bahia, 40170-115 Salvador, BA (Brazil)

    2012-05-15

    In this work, a direct sampling graphite furnace atomic absorption spectrometry method has been developed for the determination of arsenic and cadmium in crude oil samples. The samples were weighed directly on the solid sampling platforms and introduced into the graphite tube for analysis. The chemical modifier used for both analytes was a mixture of 0.1% Pd + 0.06% Mg + 0.06% Triton X-100. Pyrolysis and atomization curves were obtained for both analytes using standards and samples. Calibration curves with aqueous standards could be used for both analytes. The limits of detection obtained were 5.1 {mu}g kg{sup -1} for arsenic and 0.2 {mu}g kg{sup -1} for cadmium, calculated for the maximum amount of sample that can be analyzed (8 mg and 10 mg) for arsenic and cadmium, respectively. Relative standard deviations lower than 20% were obtained. For validation purposes, a calibration curve was constructed with the SRM 1634c and aqueous standards for arsenic and the results obtained for several crude oil samples were in agreement according to paired t-test. The result obtained for the determination of arsenic in the SRM against aqueous standards was also in agreement with the certificate value. As there is no crude oil or similar reference material available with a certified value for cadmium, a digestion in an open vessel under reflux using a 'cold finger' was adopted for validation purposes. The use of paired t-test showed that the results obtained by direct sampling and digestion were in agreement at a 95% confidence level. Recovery tests were carried out with inorganic and organic standards and the results were between 88% and 109%. The proposed method is simple, fast and reliable, being appropriated for routine analysis. - Highlights: Black-Right-Pointing-Pointer A direct sampling GF AAS method to determine As and Cd in crude oil was proposed. Black-Right-Pointing-Pointer The conventional chemical modifier Pd/Mg has been used to stabilize As and Cd. Black

  16. Speciation of mercury in fish samples by flow injection catalytic cold vapour atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► Successful speciation of inorganic and organic Hg with Fe3+, Cu2+ and thiourea as catalysts. ► Best sensitivity enhancement and similar sensitivity for MeHg and Hg2+ with Fe3+. ► Successful use of Hg2+ as the primary standard for quantification of inorganic and total-Hg. ► Quantitative extraction of Hg and MeHg with 2 M HCl which contained thiourea. ► Integration with FIA for rapid analysis with a sample throughput of 180 h−1. - Abstract: A rapid flow injection catalytic cold vapour atomic absorption spectrometric (FI-CCV-AAS) method is described for speciation and determination of mercury in biological samples. Varying concentrations of NaBH4 were employed for mercury vapour generation from inorganic and mixture of inorganic and organic (total) Hg. The presence of Fe3+, Cu2+ and thiourea had catalytic effect on mercury vapour generation from methylmercury (MeHg) and, when together, Cu2+ and thiourea had synergistic catalytic effect on the vapour generation. Of the two metal ions, Fe3+ gave the best sensitivity enhancement, achieving the same sensitivity for MeHg and inorganic Hg2+. Due to similarity of resulting sensitivity, Hg2+ was used successfully as a primary standard for quantification of inorganic and total Hg. The catalysis was homogeneous in nature, and it was assumed that the breaking of the C-Hg bond was facilitated by the delocalization of the 5d electron pairs in Hg atom. The extraction of MeHg and inorganic mercury (In-Hg) in fish samples were achieved quantitatively with hydrochloric acid in the presence of thiourea and determined by FI-CCV-AAS. The application of the method to the quantification of mercury species in a fish liver reference material DOLT-4 gave 91.5% and 102.3% recoveries for total and methyl mercury, respectively. The use of flow injection enabled rapid analysis with a sample throughput of 180 h−1.

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

    Directory of Open Access Journals (Sweden)

    Mariam Nawaz

    2013-02-01

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

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

    Science.gov (United States)

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

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

  19. A simplified technique to determine the self-absorption correction for sediment samples

    International Nuclear Information System (INIS)

    A self-absorption correction factor is required for the determination of the radioactive isotope concentration in sediment samples at the low-energy region. A simplified technique for this correction factor for a well-type HP germanium detector is described. This correction is especially important when the ratio between the sample density and reference sample density (ρsa./ρre) is greater than approximately 1.4

  20. Comparison of coal digestion methods for atomic absorption determination of cadmium in coal

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Ryozo; Kamata, Eijiro; Goto, Kazuo; Shibata, Shozo (Government Industrial Research Inst., Nagoya (Japan))

    1983-08-01

    To determine cadmium in coals, the decomposition method of coal matrix by using nitric-perchloric acid digestion in the sealed PTFE vessel modified in the authors laboratory was compared, in referring the recovery of cadmium, with nitric-hydrofluoric acid digestion followed by perchloric-periodic acid digestion, low temperature ashing method, and ASTM ashing method. The analytical values of NBS 1632a coal using these decomposition methods were all agreed with that of NBS certified. The cadmium quantity over than 1.0 ppm found to be determine by the calibration method with a representative synthesized coal solution containing the same quantities of acids as used in the procedure, without matching the major elements in coal digests. One half a gram of coal samples were treated in the sealed PTFE vessel with 7 ml of 1:1 perchloric-nitric acid mixture, heating at 150/sup 0/C for 7 h followed by hydrofluoric acid digestion, addition of boric acid, aquatic dilution and filtration. The solutions were then nebulized for the atomic absorption measurement. In the cadmium quantity less than 1.0 ppm, both the acid digests and the ashed samples were treated with hydrofluoric acid to expel silicic materials and then with dithizone-CCL/sub 4/ reagent to extract cadmium in the presence of ammonium citrate at pH 9.5--10. The organic layer was back-extracted with 2:100 hydrochloric acid. Eight coals mined in Australia, Canada, China, and Japan were analyzed. The correlation coefficient of concentrations of cadmium upon those of zinc was calculated to be 0.75, which showed cadmium occurred closely with zinc in coal.

  1. Electrochemical and chemical generation of volatile form of cadmium for quartz furnace atomic absorption

    International Nuclear Information System (INIS)

    Complete text of publication follows. The method for generation of a volatile form of cadmium by means of continuous flow / flow injection electrochemical vapor generation from aqueous samples and determination (direct; without trapping) with a quartz furnace atomic absorption spectrometer was developed in this work. A laboratory made thin layer flow-through electrochemical cell with lead or lead/tin alloy cathode served as the vapour generator. Various cathode chamber arrangements with different active surface areas were tested. Experimental set-up was optimized to attain the maximum sensitivity for Cd determination and to minimize the limits of detection and determination. The influence of the experimental parameters on the analytical signal was studied and optimal conditions for electrochemical cadmium vapor generation were found. The optimum experimental parameters for electrochemical generation were: catholyte (0.5 mol x l-1 HCl) / anolyte (2.0 mol x l-1 H2SO4) flow rate 3.0 ml x min-1; applied generation current 1.5 A (for common used thin-layer generation cell) and carrier gas flow rate 25 ml x min-1. Several gas-liquid separator designs were investigated and the effect of several reagents previously reported as sensitivity enhancers (thiourea and cationic surfactant) was observed. The results of electrochemical cadmium vapor generation were compared with the chemical generation using NaBH4 as a reduction agent. The limit of detection (3s criterion, FI mode) was 0.8 ng x ml-1 and repeatability (expressed as relative standard deviation) for concentration of 50 ng x ml-1 Cd was better than 2% for electrochemical cadmium vapor generation. The proposed method was applied to the analysis of Cd content in standard reference material: NIST 1643d (trace elements in water) and in spiked tap water samples. The authors thank to The Grant Agency of the ASCR (Project: A400310507/2005) and to Ministry of Education of Czech Republic (Project: MSM 0021620857) for the

  2. Applications of atomic absorption spectroscopy towards the analysis of scalp hair diagnosing epilepsy

    International Nuclear Information System (INIS)

    In recent years a considerable effort has been directed at the measurement of trace metal levels in various human tissues with the view of correlating these trace metals to human health and disease Scalp hair has been suggested as a potentially valuable tissue in recording changes in the levels of many trace, elements in the body over a long period of time. Levels of fe, Cu, Zn, Cr, Mg and Ca are determined in scalp hair adult epileptic normal male and female subjects by atomic absorption spectroscopy. A total of 85 hair samples for normal male/female subjects and 78 of male/female epileptic subjects were analyzed within the respective age groups of 28 to 30 and 24 to 27 years. The study showed higher average concentration of Zn, Fe and Cu in normal male adults than those found in epileptic subjects. Epileptic females showed higher average concentrations of Zn, Ca and Cu. The correlation coefficient study indicated significant correlation (r>0.589 at p=0.001) between Fe and Cr, Mg. Ca and Cu for epileptic females only. For normal male subjects Ca showed a strong correlation for Zn and Fe and for Cr and Ca. The regression analysis showed the significant role of Zn, Ca, Mg and Cr in scalp hair of normal and epileptic subjects. Accordingly, the metal to metal ratio analysis revealed critical Mg/Zn ratios as indicators of healthy (1) subjects. The ratio date are used for evaluation of the status of epileptic patients based on their ailment history. (author)

  3. Analysis of Cu and Zn elements in human hair using atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Quality and concentration of elements in human hair can reflect health status of the person or the environment where that person resides or work. High concentration of Zn can cause toxic to the human body or deficiency for Cu. Low concentration of Cu can cause cell lack of oxygen and lead to anemia. In this study determination of Cu and Zn were carried out using flame atomic absorption spectrofotometry. The analysis results on 27 hair samples of young people at 16 to 19 years-old from Bandung city indicated that geomean concentrations of Cu = 15.7 ± 45 µg/g and Zn = 20.4 ± 205 µg/g. The geomean data of copper of young Bandung (Indonesian) was lower than that of young Nigerian (11.4 µg/g), whereas two data of copper which caused high standard deviation (45 µg/g) were sample number 13 (110 µg/g) and sample number 18 (218 µg/g) maybe it come from pollutant source around the young Indonesian live. Similar to copper data, standard deviation of Zn is also high (205 µg/g). It is due to sample number 6 (657 µg/g), sample number 7 (356 µg/g), sample number 9 (1058 µg/g), sample number 21 (460 µg/g), and sample number 27 (436 µg/g), If the geomean of Zn (201.4 µg/g) was compared with the geomean of young Nigerian (125.9 µg/g), then concentration of Zn from young Indonesian was higher. The high concentration of Zn maybe become characteristic of young Bandung people or Indonesian, but it still need further study. (author)

  4. Determination of Lead in Human Teeth by Hydride Generation Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Hassan T. Abdulsahib

    2011-01-01

    Full Text Available Problem statement: The determination of lead in human teeth at concentration levels of ìg/ml is proposed using Hydride Generation Atomic Absorption Spectrometry (HG-AAS. To do this, 2% (wv lanthanum chloride solution is employed as matrix modifying reagent to increase sensitivity and remove matrix interferences. Approach: About 100 µL of sample and 100 µL of 3.0% (m/v NaBH4 are simultaneously injected into carrier streams. The detection of limit of 0.46 µg L-1 for Pb was achieved and the relative standard deviation of 3.0% for 10 µg L-1 lead was obtained. The recovery percentage of the method has been found to be (92.8-100.5% for known quantities of lead added to teeth sample which were completely recovered. A comparison of the proposed method with standard addition method showed nearly results in the same samples of teeth and the results compared with other studies in the world. Results: The method was shown to be satisfactory for determination of traces of lead in teeth samples with excellent accuracy. Teeth analysis reveals that intact teeth contained the highest amounts of lead which provide an evidence that lead may reduce the prevalence of dantal caries. Statistically significant differences (pConclusion: Statistically significant difference between age groups were seen in the mean value of lead concentrations in human teeth, the concentration of lead increased with age. The differences may be due to the exposure of lead and others factors such as differences in diet and drinking water.

  5. Simple analysis of total mercury and methylmercury in seafood using heating vaporization atomic absorption spectrometry.

    Science.gov (United States)

    Yoshimoto, Keisuke; Anh, Hoang Thi Van; Yamamoto, Atsushi; Koriyama, Chihaya; Ishibashi, Yasuhiro; Tabata, Masaaki; Nakano, Atsuhiro; Yamamoto, Megumi

    2016-01-01

    This study aimed to develop a simpler method for determining total mercury (T-Hg) and methylmercury (MeHg) in biological samples by using methyl isobutyl ketone (MIBK) in the degreasing step. The fat in the samples was extracted by MIBK to the upper phase. T-Hg transferred into the water phase. This was followed by the extraction of MeHg from the water phase using HBr, CuCl2 and toluene. The MeHg fraction was reverse-extracted into L-cysteine-sodium acetate solution from toluene. The concentrations of T-Hg and MeHg were determined by heating vaporization atomic absorption spectrometry. Certified reference materials for T-Hg and MeHg in hair and fish were accurately measured using this method. This method was then applied to determine T-Hg and MeHg concentrations in the muscle, liver and gonads of seafood for the risk assessment of MeHg exposure. The mean T-Hg and MeHg concentrations in squid eggs were 0.023 and 0.022 µg/g, and in squid nidamental glands 0.052 and 0.049 µg/g, respectively. The MeHg/T-Hg ratios in the eggs and nidamental glands of squid were 94.4% and 96.5%, respectively. The mean T-Hg and MeHg concentrations in the gonads of sea urchins were 0.043 and 0.001 µg/g, respectively, with a MeHg/T-Hg ratio of 3.5%. We developed an efficient analytical method for T-Hg and MeHg using MIBK in the degreasing step. The new information on MeHg concentration and MeHg/T-Hg ratios in the egg or nidamental glands of squid and gonads of sea urchin will also be useful for risk assessment of mercury in seafood. PMID:27432235

  6. Influence of soil and agricultural technique in metal absorption by vegetables

    International Nuclear Information System (INIS)

    The aim of this work is to verify the influence of soil and agricultural techniques in the metal absorption by the vegetables. Metal concentrations were evaluated in soil and vegetable samples from different regions and cultivated by different agricultural techniques. PIXE, 252Cf-PDMS and Radiochemical techniques were applied. Si, Zr, Ce, Th and Pb, identified in soil samples, were not biologically available. Ga, Ge, As and Br, identified in tubercles, show that spray pesticides used on the vegetable leaves were absorbed by them. 232Th and 238U, presented in the soil, were not absorbed by the vegetables. Airborne particles from anthropogenic sources (CFn, VCn) were absorbed by the vegetables. Compounds from mineral sources, presented in soil, (V+, VCO3, HPO4, Cr+, CrOH+ Mn+, FeH, Fe(OH)n) and bioorganic compounds (N+, Ca(CN)n +, CnH+) were identified in the vegetables. Metal absorbed by the vegetables is not dependent on metal concentration in soil. Different tubercles cultivated in the same soil show similar metal absorption. The exogenous contributions, such as the elements presented in water irrigation, pesticides, fertilizers and airborne particles deposited on leaves can be absorbed by the vegetables. Absorption by the roots depends on the chemical compound of the elements. Pesticide sprays and air pollution can cause more contamination in the vegetables than in the soil. The use of this methodology allows the identification of possible sources of metals in soils and in vegetables and metal speciation. (author)

  7. Study of the texture of porous solids using a technique of γ ray absorption

    International Nuclear Information System (INIS)

    A technique, which enables us to measure locally total porosity, open porosity and pore size distribution is developed. The total porosity is calculated from the bulk density. A gamma absorption gauge is set up fitted with a Cs137 source. This enables the determination of the density by layers of carbonaceous samples in a practically automatic way. By taking adequate precautions it is possible to obtain the density with a maximum error Δρ ≤ 0,005 g/cm3. The open porosity is evaluated by the absorption method after impregnation with bromoform. A new mercury porosimeter is developed using the absorption probe for the measurement of mercury infiltrated into the porous sample. Due to the localized character of exploration by this technique, the variations of porous texture in a heterogeneous sample can be studied. Used as a classical porosimeter, in the case of homogeneous samples, this apparatus is capable of exploring the equivalent diameters of pores between 500 μ and 0.14 μ with a maximum error ΔP ≤ 0.002. The possibility of exploration of heterogeneous samples, with the facility of determination of porosities due to macro-pores combined with the non-limiting character of the method in the field of high pressures differentiates this apparatus from all the porosimeters of former conception. Examples of utilization of this technique in the case of graphite-gas reactions are presented. (author)

  8. Development of a methodology for low-energy X-ray absorption correction in biological samples using radiation scattering techniques

    International Nuclear Information System (INIS)

    Non-destructive techniques with X-ray, such as tomography, radiography and X-ray fluorescence are sensitive to the attenuation coefficient and have a large field of applications in medical as well as industrial area. In the case of X-ray fluorescence analysis the knowledge of photon X-ray attenuation coefficients provides important information to obtain the elemental concentration. On the other hand, the mass attenuation coefficient values are determined by transmission methods. So, the use of X-ray scattering can be considered as an alternative to transmission methods. This work proposes a new method for obtain the X-ray absorption curve through superposition peak Rayleigh and Compton scattering of the lines La e Lβ of Tungsten (Tungsten L lines of an X-ray tube with W anode). The absorption curve was obtained using standard samples with effective atomic number in the range from 6 to 16. The method were applied in certified samples of bovine liver (NIST 1577B) , milk powder and V-10. The experimental measurements were obtained using the portable system EDXRF of the Nuclear Instrumentation Laboratory (LIN-COPPE/UFRJ) with Tungsten (W) anode. (author)

  9. Identifying student and teacher difficulties in interpreting atomic spectra using a quantum model of emission and absorption of radiation

    Science.gov (United States)

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

    2016-06-01

    Our study sets out to identify the difficulties that high school students, teachers, and university students encounter when trying to explain atomic spectra. To do so, we identify the key concepts that any quantum model for the emission and absorption of electromagnetic radiation must include to account for the gas spectra and we then design two questionnaires, one for teachers and the other for students. By analyzing the responses, we conclude that (i) teachers lack a quantum model for the emission and absorption of electromagnetic radiation capable of explaining the spectra, (ii) teachers and students share the same difficulties, and (iii) these difficulties concern the model of the atom, the model of radiation, and the model of the interaction between them.

  10. Computer programs in BASIC language for atomic absorption flame spectroscopy. Part 2. Documentation. [SEMIAUTOMATIC, RANDOM, and BRACKET codes

    Energy Technology Data Exchange (ETDEWEB)

    Boyle, W.G. Jr.

    1977-10-28

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

  11. Arsenic speciation analysis by cryogenic trapping – hydride generation – atomic absorption spectrometry; Investigation of water vapour dryers

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Milan; Taurková, Petra; Matoušek, Tomáš; Rychlovský, P.; Dědina, Jiří

    Prague: Charles University in Prague, Faculty of Science, 2010 - (Nesměrák, K.), s. 15-18. (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 absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation

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

    International Nuclear Information System (INIS)

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

  13. Determination of calcium, copper, chromium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The direct determinacao of calcium, copper, chomium, iron, magnesium, manganese, potassium, sodium and zinc in ethanol by atomic absorption spectrometry with, air-acetylene flame is proposed. Effects of fuel/oxidant ratio, burner height and water content in the samples were investigated in detail. The method allows the determition of the elements with good precision (r.s.d. -1 for the elements tested. (author)

  14. Dispersive Liquid-Liquid Microextraction of Bismuth in Various Samples and Determination by Flame Atomic Absorption Spectrometry

    OpenAIRE

    Teslima Daşbaşı; Şenol Kartal; Şerife Saçmacı; Ahmet Ülgen

    2016-01-01

    A dispersive liquid-liquid microextraction method for the determination of bismuth in various samples by flame atomic absorption spectrometry is described. In this method, crystal violet was used as counter positive ion for BiCl4 − complex ion, chloroform as extraction solvent, and ethanol as disperser solvent. The analytical parameters that may affect the extraction efficiency like acidity of sample, type and amount of extraction and disperser solvents, amount of ligand, and extraction time ...

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

    OpenAIRE

    Jelena Milinović; Rada Đurović

    2007-01-01

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

  16. Determination of Trace Silver in Water Samples by Online Column Preconcentration Flame Atomic Absorption Spectrometry Using Termite Digestion Product

    OpenAIRE

    Joyce Nunes Bianchin; Eduardo Carasek; Edmar Martendal

    2011-01-01

    A new method for Ag determination in water samples using solid phase extraction (SPE) coupled to a flow injection system and flame atomic absorption spectrometry was developed. The sorbent used for Ag preconcentration and extraction was the termite digestion product. Flow and chemical variables of the system were optimized through a multivariate procedure. The factors selected were adsorbent mass, buffer type and concentration, sample pH, and sample flow rate. The detection limit and precisio...

  17. Towards broadening thermospray flame furnace atomic absorption spectrometry: Influence of organic solvents on the analytical signal of magnesium

    OpenAIRE

    Ezequiel Morzan; Jorge Stripeikis; Mabel Tudino

    2015-01-01

    This study demonstrates the influence of the solvent when thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is employed for the determination of elements of low volatility, taking magnesium (Mg) as leading case. Several organic solvents/water solutions of different characteristics (density, surface tension, viscosity, etc.) and proportions were employed for the TS-FF-AAS analytical determination. To this end, solutions containing methanol, ethanol and isopropanol in water w...

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

    Science.gov (United States)

    Meier, A.L.

    1982-01-01

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

  19. Distinguishing plasmonic absorption modes by virtue of inversed architectures with tunable atomic-layer-deposited spacer layer

    International Nuclear Information System (INIS)

    We demonstrated the distinguishing between plasmonic absorption modes by exploiting an inversed architecture with tunable atomic-layer-deposited dielectric spacer layer. The dielectric spacer layer was manipulated between the bottom metal–nanoparticle monolayer and the upper metal film to inspect the contributions of metal nanoparticles and dielectric film in a step-by-step manner. The experimental and simulated differences between the two peak absorption positions (Δf) and between the corresponding half width at half maxima (Δw) confirmed the evolutions of gap plasmon and interference-enhanced local surface plasmon resonance absorption modes in the plasmonic metamaterial absorbers (PMAs), which were useful for understanding the underlying mechanism of amorphous PMAs. (paper)

  20. Application of atomic absorption spectrophotometry to determine Cd, Cu, Pb, Zn,...in vegetable samples in Dalat

    International Nuclear Information System (INIS)

    Nowadays atomic absorption spectrometry has become valuable method for trace element analysis because high specificity; low detection litmus, easy to use; easy sample preparation, low investment and running costs... atomic absorption spectrometry is generally accepted as one the most suitable method for single - element analysis of trace elements in various kinds of materiel. In 2003, we applied flame - atomic absorption spectrometry for analyzing Ca, Cd, Cu, Pb, Zn...in vegetables and their extracted juices were collected form 11 locations of Dalat, including two kinds of vegetables (goods and safety) in both the summer and winter. Average concentration of Ca = 240 mg/kg wet, Cd = 0.035 mg/kg wet, Cu = 0.67 mg/kg wet, Mg = 131 mg/kg wet, Fe = 8.1/kg wet, Mn = 3.1/kg wet, Na = 3266 mg/kg wet, Pb = 0.345 mg/kg wet and Zn = 3.3 mg wet. In their extracted juices: Ca = 89 mg/kg wet, Cd = 0.008 mg/kg wet, Cu = 0.19 mg/kg wet, Mg = 43 mg/kg wet, Fe = 2.3 mg/kg wet, Mn = 0.61 mg/kg wet, Na = 971 mg/kg wet, Pb = 0.107 mg/kg wet and Zn = 0.65 mg/kg wet. (author)

  1. Atomic transition frequencies, isotope shifts, and sensitivity to variation of the fine structure constant for studies of quasar absorption spectra

    CERN Document Server

    Berengut, J C; Flambaum, V V; King, J A; Kozlov, M G; Murphy, M T; Webb, J K

    2010-01-01

    Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental "constants" in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic transitions in quasar absorption systems. Recent studies using 140 absorption systems from the Keck telescope and 153 from the Very Large Telescope, suggest that alpha varies spatially. That is, in one direction on the sky alpha seems to have been smaller at the time of absorption, while in the opposite direction it seems to have been larger. To continue this study we need accurate laboratory measurements of atomic transition frequencies. The aim of this paper is to provide a compilation of transitions of importance to the search for alpha variation. They are E1 transitions to the ground state in several different atoms and ions, with wavelengths ranging from around 900 - 6000 A, and require an accuracy of better than 10^{-4} A. We discuss isotope shift measurements that are...

  2. In situ collection of volatile silver species in a new modular quartz tube atomizer for atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Kratzer, Jan; Vobecký, Miloslav; Matoušek, Tomáš

    2012-01-01

    Roč. 27, č. 9 (2012), s. 1382-1390. ISSN 0267-9477 R&D Projects: GA ČR GA203/09/1783 Institutional support: RVO:68081715 Keywords : volatile species generation * in-situ collection * quartz tube atomizer Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.155, year: 2012

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

    Czech Academy of Sciences Publication Activity Database

    Musil, Stanislav; Matoušek, Tomáš; Dědina, Jiří

    2015-01-01

    Roč. 108, JUN (2015), s. 61-67. ISSN 0584-8547 R&D Projects: GA ČR GA14-23532S Grant ostatní: GA AV ČR(CZ) M200311202 Institutional support: RVO:68081715 Keywords : silver * volatile species generation * sapphire tube atomizer Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.176, year: 2014

  4. Species selective preconcentration and quantification of gold nanoparticles using cloud point extraction and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Highlights: ► We optimized cloud point extraction and ET-AAS parameters for Au-NPs measurement. ► A selective ligand (sodium thiosulphate) is introduced for species separation. ► A limit of detection of 5 ng Au-NP per L is achieved for aqueous samples. ► Measurement of samples with high natural organic mater content is possible. ► Real water samples including wastewater treatment plant effluent were analyzed. - Abstract: The determination of metallic nanoparticles in environmental samples requires sample pretreatment that ideally combines pre-concentration and species selectivity. With cloud point extraction (CPE) using the surfactant Triton X-114 we present a simple and cost effective separation technique that meets both criteria. Effective separation of ionic gold species and Au nanoparticles (Au-NPs) is achieved by using sodium thiosulphate as a complexing agent. The extraction efficiency for Au-NP ranged from 1.01 ± 0.06 (particle size 2 nm) to 0.52 ± 0.16 (particle size 150 nm). An enrichment factor of 80 and a low limit of detection of 5 ng L−1 is achieved using electrothermal atomic absorption spectrometry (ET-AAS) for quantification. TEM measurements showed that the particle size is not affected by the CPE process. Natural organic matter (NOM) is tolerated up to a concentration of 10 mg L−1. The precision of the method expressed as the standard deviation of 12 replicates at an Au-NP concentration of 100 ng L−1 is 9.5%. A relation between particle concentration and the extraction efficiency was not observed. Spiking experiments showed a recovery higher than 91% for environmental water samples.

  5. High-Energy X-ray Absorption Diagnostics as an Experimental Combustion Technique

    Science.gov (United States)

    Dunnmon, Jared; Sobhani, Sadaf; Hinshaw, Waldo; Fahrig, Rebecca; Ihme, Matthias

    2015-11-01

    X-ray diagnostics such as X-ray Computed Tomography (XCT) have recently been utilized for measurement of scalar concentration fields in gas-phase flow phenomena. In this study, we apply high-energy X-ray absorption techniques to visualize a laboratory-scale flame via fluoroscopic measurements by using krypton as a radiodense tracer media. Advantages of X-ray absorption diagnostics in a combustion context, including application to optically inaccessible environments and lack of ambient photon interference, are demonstrated. Analysis methods and metrics for extracting physical insights from these data are presented. The accuracy of the diagnostic is assessed via comparison to known results from canonical flame configurations, and the potential for further applications is discussed. Support from the NDSEG fellowship, Bosch, and NASA are gratefully acknolwedged.

  6. Determination of yttrium and rare-earth elements in rocks by graphite-furnace atomic-absorption spectrometry.

    Science.gov (United States)

    Gupta, J G

    1981-01-01

    With use of synthetic solutions and several international standard reference materials a method has been developed for determining traces of Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in rocks by electrothermal atomization in a pyrolytically-coated graphite furnace. Depending on the element, the sensitivity is of the order of 10(-9)-10(-12) g at 2500 degrees . To avoid matrix interferences the lanthanides are separated from the common elements by co-precipitation with calcium and iron as carriers. The data for Canadian reference rock SY-2 (syenite), U.S.G.S. reference rocks W-2 (diabase), DNC-1 (diabase) and BIR-1 (basalt), and South African reference rock NIM-18/69 (carbonatite) obtained by graphite-furnace atomization are compared with the values obtained by flame atomic-absorption. The results are in good agreement with literature values. PMID:18962852

  7. Direct determination of selenium in rat blood plasma by Zeeman atomic absorption spectrometry.

    Science.gov (United States)

    Kabirov, K K; Kapetanovic, I M; Lyubimov, A V

    2008-01-30

    The method was developed to be applied for direct determination of selenium in rat plasma by graphite-furnace atomic absorption spectrometry with Zeeman background correction. Blood was obtained from CD rats of both sexes 2h after dosing in weeks 7 and 13 in order to acquire data on the levels of selenium in these animals during 13-week gavage administration of l-seleno-methylselenocysteine (SeMC), a new candidate chemopreventive agent under development. Application of the commonly used method of standard addition was found to be unsuitable to calculate the selenium content in rat plasma (within-run and between-run accuracy and precision parameters were less than 85%). Therefore, a new analytical method was developed. In this method, samples of rat plasma (50 microL) were diluted 10-fold with a reducing agent containing l-ascorbic acid, a modifier solution containing palladium chloride and Triton X-100. Samples were atomized in pyrolytically coated graphite tubes and peak height signals were measured. Selenium concentrations were determined by linear least squares regression analysis based on the standard curve generated in pooled rat blank plasma. Since selenium is normally present in plasma, a three-step approach was used to calculate selenium plasma levels. Initially selenium levels were determined based on the standard curve with selenium-spiked pool plasma. In the second step, background selenium levels in the pooled plasma were determined based on the same standard curve. In the third step, background level was added to the previously derived number. The relative errors were in the range from -4.6 to 11.4% (intra-day assay) and from -0.4 to 8.8% (inter-day assay) which proved good accuracy. The relative standard deviations were in the range from 1.88 to 4.70% (intra-day precision) and from 3.28 to 5.38% (inter-day precision). In rat plasma, the following dose-dependent selenium levels (mean+/-S.D.) in males and females, respectively, were observed at 13 weeks

  8. Determination of attenuation properties of some petroleum products in Ghana by gamma ray absorption technique

    International Nuclear Information System (INIS)

    The mass attenuation coefficient (µ/ ρ) and the mass energy absorption coefficient (µen⁄ρ) are important parameters to characterise the penetration and the interaction of gamma rays in chemical materials such as hydrocarbons. Accurate determination of values of (µ/ ρ) and (µen⁄ρ) are relevant in estimating certain important physical properties of petroleum products. In this study, gamma – ray absorption technique has been used to determine mass attenuation coefficients and mass energy absorption coefficients of the following petroleum products; Kerosene, Aviation Turbine Kerosene, Gasoline (Petrol) and Gasoil (Diesel). Gamma photon energy of 662 keV from a 30 mCi (137Cs) source was utilised together with NaI (Tl) Scintillation detector and Ludlum ratemeter (Gamma Counter). The Theoretical values of mass attenuation coefficient and the mass energy absorption coefficient of each petroleum products was calculated. Experimental results were compared with theoretical ones showing a good correlation between methods. These attenuation properties can be used to determine some physical parameters of petroleum products such as density and hence check adulterations in petroleum products. The experimental values of (µ/ ρ) of the petroleum samples range from 0. 0855 to 0.0911 (cm2/g), the theoretical values of (µ/ ρ) were between 0.0916 and 0.0932(cm2/g) with error deviation from 3% to 7%. The experimental and theoretical mass energy absorption coefficients (µen⁄ρ) recorded were in the range of 0.0330 to 0.0352(cm2/g) and 0.0336 to 0.0342 (cm2/g) respectively, having an error deviation between 1% and 3%. (au)

  9. Studies on mercury contamination in the Brazilian Amazonic region using neutron activation analysis and atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    technique, atomic absorption spectroscopy, and it was concluded that most of the mercury was present in the hair as the dangerous methylmercury. It is known already that the most probable source of methylmercury for humans is fish ,due to the fact that they can concentrate methylmercury many times. Since the Indians consume fish on a daily basis, this could be the reason for the presence of very high amounts of mercury in their hair and also in their blood, as shown by other studies. (author)

  10. Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6–4.3%), repeatability (4–9%), reproducibility (9–11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as

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

    DEFF Research Database (Denmark)

    Loubet, Bastien; Kopec, Wojciech; Khandelia, Himanshu

    2014-01-01

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

  12. 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

  13. Glove box adaptation, installation and commissioning of an assembled modular type atomic absorption unit with GF atomizer

    International Nuclear Information System (INIS)

    The report describes glove box adaptation of an in-house developed AAS unit with GF as atomization source for determination of trace metallic elements in Pu bearing samples. In order to replace the old Varian Techtron GF-AAS which was utilized for analysis of Pu bearing samples for the last thirty seven years, and as of late was giving too many practical problems, a new GF-AAS was designed and reassembled. The original compact flame AAS unit available with M/s. Thermo Fisher India Pvt. Ltd, Nashik, was converted into separated modular unit viz. Hollow Cathode Lamp unit, Atomizer unit and Monochromator - Detector - Readout unit. In addition, these modular units were modified with respect to their dimensions so as to enable their use with existing glove box facility developed earlier in 1980 for glove box incorporation. These units were separated from each other at their factory site so as to enable us to incorporate atomizer unit alone in the glove box. Glove box adapted GF-AAS is essential for Radiochemistry Division to provide analytical services to Chemical Quality Control of Pu bearing nuclear and related materials and also as an analytical support to the R and D activities of the Radiochemistry Division, BARC. (author)

  14. Determination of various extracted Al species and their fractions by atomic spectrometry techniques

    International Nuclear Information System (INIS)

    Complete text of publication follows. During the last few decades aluminium and its distribution in the environment has attracted much attention because of Al toxic effects to the plants, animals and humans. Its concentration in different environmental samples varies widely. While determination of high Al concentrations can be realized with no serious problem, reliable determination of its trace and ultratrace concentrations requires the development of enrichment techniques capable of improving both, the selectivity and also sensitivity for this analyte. Two extraction methods were used for selective separation and preconcentration of aluminium trace concentrations from model solutions. Solid phase extraction (SPE) using nanometer-sized titanium dioxide as a solid sorbent and cloud point extraction (CPE) using nonionic surfactant octylphenoxypolyethoxyethanol (Triton X-114) were utilized. Spectrometry techniques such as flame (F AAS) and electrothermal (ET AAS) atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry (ICP OES) or inductively coupled plasma mass spectrometry (ICP MS) were applied for the determination of aluminium. Direct TiO2-slurry sampling was used for sample injection into the graphite furnace of ET AAS in SPE. Optimized procedures were used for the determination of trace and ultratrace amounts of total aluminium and various aluminium species and their fractions in speciation analysis and fractionation studies using environmental samples such as natural waters, soils and sediments. The work was supported by Slovak Research and Development Agency under the contracts No. APVT-20-010204, LPP-0038-06, LPP-0146-09 and SK-CZ-0044-07, by Scientific Grant Agency of Ministry of Education of Slovak Republic and the Slovak Academy of Sciences under the contracts No. VEGA 1/4464/07 and VEGA 1/0272/08 and by Ministry of Education, Youth and Sports of Czech Republic under the contract No. MEB 080813.

  15. 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)

  16. Investigation of ion-atom collision dynamics through imaging techniques

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The principle and technique details of recoil ion momentum imaging are discussed and summarized. The recoil ion momentum spectroscopy built at the Institute of Modern Physics (Lanzhou) is presented. The first results obtained at the setup are analyzed. For 30 keV He2+ on He collision, it is found that the capture of single electron occurs dominantly into the first excited states, and the related scattering angle results show that the ground state capture occurs at large impact parameters, while the capture into excited states occurs at small impact parameters. The results manifest the collision dynamics for the sub-femto-second process can be studied through the techniques uniquely. Finally, the future possibilities of applications of the recoil ion momentum spectroscopy in other fields are outlined.

  17. Graphene for Preconcentration of Trace Amounts of Ni in Water and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens Prior to flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    Hanie Arbabi Rashid

    2014-03-01

    Full Text Available A new sensitive and simple method was developed for the preconcentration of trace amounts of Ni using 1-(2-pyridylazo-2-naphthol (PAN as chelating reagent prior to its determination by flame atomic absorption spectrometry. The proposed method is based on the uti- lization of a column packed with graphene as sorbent. Several effective parameters on the extraction and complex formation were selected and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 5.0–240.0 µg L-1 with a detection limit of 0.36 µg L-1. The relative standard deviation for ten replicate measurements of 20.0 and 100.0 µg L-1 of Ni were 3.45 and 3.18%, respectively. Comparative studies showed that graphene is superior to other adsorbents including C18 silica, graphitic carbon, and single- and multi-walled carbon nanotubes for the extraction of Ni. In the present study, we report the application of preconcentration techniques still continues increasingly for trace metal determinations by flame atomic absorption spectrometry (FAAS for quantification of Ni in Formalin-fixed paraffin-embedded (FFPE tissues from Liver loggerhead turtles. The proposed method was successfully applied in the analysis of four real environmental water samples. Good spiked recoveries over the range of 95.8–102.6% were obtained.

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

    International Nuclear Information System (INIS)

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

  19. Development and application of UV-visible and mid-IR differential absorption spectroscopy techniques for pollutant trace gas monitoring

    OpenAIRE

    Jiménez Pizarro, Rodrigo; Calpini, Bertrand

    2005-01-01

    Spatial representativeness is an important quality criterion in trace gas monitoring, especially if measurements are intended for regulatory and model validation purposes. Open-path absorption spectroscopy techniques meet the representativeness requirement by providing concentrations averaged over atmospheric paths ranging from some hundred meters to some kilometers. This research concerns the characterization and application of a UV-visible differential optical absorption spectroscopy (DOAS)...

  20. Development and application of UV-visible and mid-IR differential absorption spectroscopy techniques for pollutant trace gas monitoring

    OpenAIRE

    Jiménez Pizarro, Rodrigo

    2004-01-01

    Spatial representativeness is an important quality criterion in trace gas monitoring, especially if measurements are intended for regulatory and model validation purposes. Open-path absorption spectroscopy techniques meet the representativeness requirement by providing concentrations averaged over atmospheric paths ranging from some hundred meters to some kilometers. This research concerns the characterization and application of a UV-visible differential optical absorption spectroscopy (DOAS)...

  1. Determination of the elemental composition of cyanobacteria cells and cell fractions by atomic emission and atomic absorption spectrometry

    International Nuclear Information System (INIS)

    An approach to studying the elemental composition of cyanobacteria Spirulina platensis and Nostoc commune using a set of complementary analytical methods (ICP-AES, PAAS, and ETAAS) was proposed . The procedures were adapted for the determination of macro- and microelements (Na, K, Mg, Ca, Fe, Mn, Cu, Mo, Zn, B, and Se) in the biomass of cyanobacteria and separated cell fractions (chloroform and water-methanol extracts and precipitates). The conditions for the mineralization of biological materials were optimized for autoclave and microwave sample preparation procedures. The evaporation and atomization of Se and Mo in a graphite furnace in the presence of chloroform and methanol were studied

  2. Studies on atom deceleration process by using the Zeeman-tuned technique

    International Nuclear Information System (INIS)

    The Zeeman-tuned technique to slow an atomic beam of sodium atoms was detailed studied. A new technique to study the deceleration which consists in monitoring the fluorescence along the deceleration path is used. This allows a direct observation of the process and open possibilities to investigate the adiabatic following of atoms in the magnetic field, and others very important aspects of the process. With a single laser and some modification of the magnetic field profile it is possible stop atoms outside the slower solenoid, which make a lot of experiments much simpler. A systematic study of the optical pumping effects and adiabatic following conditions allow to produce a very strong slow motion atomic beam. (author)

  3. Slurry sampling hydride generation-cryotrapping-atomic absorption spectrometry for arsenic speciation analysis in baby food

    Czech Academy of Sciences Publication Activity Database

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

    Hungarian Chemical Society, 2016 - (Mihucz, V.). s. 165 ISBN 978-963-9970-65-6. [European Symposium on Atomic Spectrometry /ESAS 2016/ & Hungarian Spectrochemical Conference /59./. 31.03.2016-02.04.2016, Eger] Institutional support: RVO:68081715 Keywords : arsenic speciation * atomic spectrometry * hydride generation Subject RIV: CB - Analytical Chemistry, Separation

  4. Self-consistent dynamical linear response of atoms in quantum plasmas: photo-absorption and collective effects in dense plasmas

    International Nuclear Information System (INIS)

    In modeling dense and partially ionized matter, the treatment of the free electrons remains an important issue. Compared to bound electrons, the delocalized and non-discrete nature of these electrons is responsible to treat them differently, which is usually adopted in the modeling of radiative properties of plasmas. However, in order to avoid inconsistencies in the calculation of absorption spectra, all the electrons should be described in the same formalism. We use two variational average-atom models: a semi-classical and a quantum model, which allow this common treatment for all the electrons. We calculate the photo-extinction cross-section, by applying the framework of the linear dynamical response theory to each of these models of an atom in a plasma. For this study, we develop and use a self-consistent approach, of random-phase-approximation (RPA) type, which, while going beyond the independent electron response, permits to evaluate the collective effects by the introduction of the dynamical polarization. This approach uses the formalism of the time dependent density functional theory (TDDFT), applied in the case of an atomic system immersed in a plasma. For both models, semi-classical and quantum, we derive and verify in our calculations, a new sum rule, which allows the evaluation of the atomic dipole from a finite volume in the plasma. This sum rule turns out to be a crucial device in the calculation of radiative properties of atoms in dense plasmas. (author)

  5. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    Energy Technology Data Exchange (ETDEWEB)

    Erikat, I. A., E-mail: ihsanas@yahoo.com [Department of Physics, Jerash University, Jerash-26150 (Jordan); Hamad, B. A. [Department of Physics, The University of Jordan, Amman-11942 (Jordan)

    2013-11-07

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

  6. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    International Nuclear Information System (INIS)

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir–C and Ir–Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule

  7. A first principle study for the adsorption and absorption of carbon atom and the CO dissociation on Ir(100) surface

    Science.gov (United States)

    Erikat, I. A.; Hamad, B. A.

    2013-11-01

    We employ density functional theory to examine the adsorption and absorption of carbon atom as well as the dissociation of carbon monoxide on Ir(100) surface. We find that carbon atoms bind strongly with Ir(100) surface and prefer the high coordination hollow site for all coverages. In the case of 0.75 ML coverage of carbon, we obtain a bridging metal structure due to the balance between Ir-C and Ir-Ir interactions. In the subsurface region, the carbon atom prefers the octahedral site of Ir(100) surface. We find large diffusion barrier for carbon atom into Ir(100) surface (2.70 eV) due to the strong bonding between carbon atom and Ir(100) surface, whereas we find a very small segregation barrier (0.22 eV) from subsurface to the surface. The minimum energy path and energy barrier for the dissociation of CO on Ir(100) surface are obtained by using climbing image nudge elastic band. The energy barrier of CO dissociation on Ir(100) surface is found to be 3.01 eV, which is appreciably larger than the association energy (1.61 eV) of this molecule.

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

    Directory of Open Access Journals (Sweden)

    Jan Grzybek

    2014-08-01

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

  9. DETERMINATION OF TRACE AMOUNTS OF SELENIUM IN CORN, LETTUCE, POTATOES, SOYBEANS, AND WHEAT BY HYDRIDE GENERATION/CONDENSATION AND FLAME ATOMIC ABSORPTION SPECTROMETRY

    Science.gov (United States)

    Because of the nutritional and toxicological significance of low selenium concentrations in agricultural crops, a procedure utilizing wet digestion followed by hydride generation/condensation-flame atomic absorption was developed for the routine analysis of selenium in different ...

  10. Exploiting flow injection and sequential injection for trace metal determinations in conjunction with detection by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    Despite their excellent analytical chemical capacities, Electrothermal Atomic Absorption Spectrometry (ETAAS) and Inductively Coupled Plasma Mass Spectrometry (ICPMS), nevertheless, often require suitable pretreatment of the sample material in order to obtain the necessary sensitivity and...

  11. A highly sensitive method for the determination of mercury using vapor generation gold wire microextraction and electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The study introduces a new simple and highly sensitive method for headspace solid phase microextraction (HS-SPME) coupled with electrothermal atomic absorption spectrometric determination of mercury. In the proposed method, a gold wire, mounted in the headspace of a sample solution in a sealed bottle, is used for collection of mercury vapor generated by addition of sodium tetrahydroborate. The gold wire is then simply inserted in the sample introduction hole of a graphite furnace of an electrothermal atomic absorption spectrometry instrument. By applying an atomization temperature of 600 deg. C, mercury is rapidly desorbed from the wire and determined with high sensitivity. Factorial design and response surface analysis methods were used for optimization of the effect of five different variables in order to maximize the mercury signal. By using a 0.75 mm diameter gold wire, a sample volume of about 8 ml and an extraction time of 11 min, the sensitivity of mercury determination was enhanced up to 104 times in comparison to its ordinary ETAAS determination with direct injection of 10 μl sample solutions. A detection limit of 0.006 ng ml-1 and a precision better than 4.6% (relative standard deviation) were obtained. The method was successfully applied to the determination of mercury in industrial wastewaters and tuna fish samples

  12. A highly sensitive method for the determination of mercury using vapor generation gold wire microextraction and electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hashemi, Payman [Department of Chemistry, Lorestan University, Khorram Abad (Iran, Islamic Republic of)], E-mail: payman_hashemi@yahoo.com; Rahimi, Akram [Department of Chemistry, Lorestan University, Khorram Abad (Iran, Islamic Republic of)

    2007-04-15

    The study introduces a new simple and highly sensitive method for headspace solid phase microextraction (HS-SPME) coupled with electrothermal atomic absorption spectrometric determination of mercury. In the proposed method, a gold wire, mounted in the headspace of a sample solution in a sealed bottle, is used for collection of mercury vapor generated by addition of sodium tetrahydroborate. The gold wire is then simply inserted in the sample introduction hole of a graphite furnace of an electrothermal atomic absorption spectrometry instrument. By applying an atomization temperature of 600 deg. C, mercury is rapidly desorbed from the wire and determined with high sensitivity. Factorial design and response surface analysis methods were used for optimization of the effect of five different variables in order to maximize the mercury signal. By using a 0.75 mm diameter gold wire, a sample volume of about 8 ml and an extraction time of 11 min, the sensitivity of mercury determination was enhanced up to 10{sup 4} times in comparison to its ordinary ETAAS determination with direct injection of 10 {mu}l sample solutions. A detection limit of 0.006 ng ml{sup -1} and a precision better than 4.6% (relative standard deviation) were obtained. The method was successfully applied to the determination of mercury in industrial wastewaters and tuna fish samples.

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

    OpenAIRE

    Acar, Orhan

    2012-01-01

    The Cd, Pb, Cu, Fe and Zn contents of some edible vegetable oils (soybean, sunflower, flower, nut, corn and olive) and of olives (olive-1, black, green, black crushed with seeds and green crushed with seeds) were determined and evaluated by an electrothermal atomic absorption spectrometer (ETAAS) using an Sc + Ir + NH4H2PO4 chemical modifier mixture and flame atomic absorption spectrometer (FAAS) after microwave digestion. T...

  14. Determination of cobalt in biological samples by line-source and high-resolution continuum source graphite furnace atomic absorption spectrometry using solid sampling or alkaline treatment

    International Nuclear Information System (INIS)

    Two procedures for the determination of Co in biological samples by graphite furnace atomic absorption spectrometry (GF AAS) were compared: solid sampling (SS) and alkaline treatment with tetramethylammonium hydroxide (TMAH) using two different instruments for the investigation: a conventional line-source (LS) atomic absorption spectrometer and a prototype high-resolution continuum source atomic absorption spectrometer. For the direct introduction of the solid samples, certified reference materials (CRM) were ground to a particle size ≤50 μm. Alkaline treatment was carried out by placing about 250 mg of the sample in polypropylene flasks, adding 2 mL of 25% m/v tetramethylammonium hydroxide and de-ionized water. Due to its unique capacity of providing a 3-D spectral plot, a high-resolution continuum source (HR-CS) graphite furnace atomic absorption spectrometry was used as a tool to evaluate potential spectral interferences, including background absorption for both sample introduction procedures, revealing that a continuous background preceded the atomic signal for pyrolysis temperatures lower than 700 deg. C. Molecular absorption bands with pronounced rotational fine structure appeared for atomization temperatures >1800 deg. C probably as a consequence of the formation of PO. After optimization had been carried out using high resolution continuum source atomic absorption spectrometry, the optimized conditions were adopted also for line-source atomic absorption spectrometry. Six biological certified reference materials were analyzed, with calibration against aqueous standards, resulting in agreement with the certified values (according to the t-test for a 95% confidence level) and in detection limits as low as 5 ng g-1

  15. EVALUATION OF HEAVY METALS IN ETHANOLIC LEAF EXTRACT OF ACACIA CATECHU AS INDICATOR OF POLLUTION BY ATOMIC ABSORPTION SPECTROPHOTOMETRIC (FAAS) ANALYSIS

    OpenAIRE

    Lakshmi T; Rajendran R; Antony silvester

    2013-01-01

    Acacia catechu ethanolic leaf extract were selected to determine their heavy metals content and thereby to assure their safer therapeutic application. The trace and heavy metals were detected through atomic absorption spectrometry analysis. The selected medicinal plant material was procured from green chem herbal extracts, Bangalore, India and was digested with nitric acid and hydrochloric acid as specified. Absorbance was measured through atomic absorption spectrometer (AA 6030) and the conc...

  16. Accurate measurement and physical insight: The X-ray extended range technique for fundamental atomic physics, condensed matter research and biological sciences

    International Nuclear Information System (INIS)

    Research in core physics or atomic and condensed matter science is increasingly relevant for diverse fields and are finding application in chemistry, engineering and biological sciences, linking to experimental research at synchrotrons, reactors and specialised facilities. Over recent synchrotron experiments and publications we have developed methods for measuring the absorption coefficient far from the edge and in the XAFS (X-ray absorption fine structure) region in neutral atoms, simple compounds and organometallics reaching accuracies of below 0.02%. This is 50-500 times more accurate than earlier methods, and 50-250 times more accurate than claimed uncertainties in theoretical computations for these systems. The data and methodology are useful for a wide range of applications, including major synchrotron and laboratory techniques relating to fine structure, near-edge analysis and standard crystallography. Experiments are sensitive to theoretical and computational issues, including correlation between convergence of electronic and atomic orbitals and wavefunctions. Hence, particularly in relation to the popular techniques of XAFS and XANES (X-ray absorption near-edge structure), this development calls for strong theoretical involvement but has great applications in solid state structural determination, catalysis and enzyme environments, active centres of biomolecules and organometallics, phase changes and fluorescence investigations and others. We discuss key features of the X-ray extended range technique (XERT) and illustrate applications.

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

    Science.gov (United States)

    Ozbek, Nil; Akman, Suleyman

    2016-07-20

    Total chlorine in milk was determined via the molecular absorption of diatomic strontium monochloride at 635.862 nm using high-resolution continuum source graphite furnace atomic absorption spectrometry. The effects of coating the graphite furnace, using different modifiers, amount of molecule-forming element, and different calibrants were investigated and optimized. Chlorine concentrations in milk samples were determined in a Zr-coated graphite furnace using 25 μg of Sr as the molecule-forming reagent and applying a pyrolysis temperature of 600 °C and a molecule-forming temperature of 2300 °C. Linearity was maintained up to 500 μg mL(-1) of Cl. The method was tested by analyzing a certified reference wastewater. The results were in the uncertainty limits of the certified value. The limit of detection of the method was 1.76 μg mL(-1). The chlorine concentrations in various cow milk samples taken from the market were found in the range of 588-1472 mg L(-1). PMID:27345208

  18. A theoretical molecular orbital approach to the adsorption and absorption of atomic hydrogen on Ni(111)

    Energy Technology Data Exchange (ETDEWEB)

    Ferullo, R.M. (Planta Piloto de Ingenieria Quimica (UNS-CONICET), Bahia Blanca (Argentina)); Castellani, N.J. (Planta Piloto de Ingenieria Quimica (UNS-CONICET), Bahia Blanca (Argentina))

    1993-02-19

    A semiempirical molecular orbital approach to the H-Ni interaction for a hydrogen atom adsorbed on the (111) surface or immersed in the bulk of Ni is given. The results show that the chemisorptive surface sites are more stable than the subsurface interstitials and that the bulk octahedral sites are more stable than the tetrahedral sites, in agreement with earlier models. The repulsive influence on hydrogen atom adsorption due to other hydrogen atoms residing in the nearer subsurface interstitials is also considered and discussed in terms of electronic arguments. (orig.)

  19. Nonstationary structure of atomic and molecular layers in electrothermal. Atomic absorption spectrometry: formation of atomic and molecular absorbing layers of gallium and indium

    International Nuclear Information System (INIS)

    The dynamics of the formation of absorbing layers of gallium and indium atoms and their compounds in a graphite tubular atomizer was investigated by the shadow spectral filming method. These compounds are localozed in the central part of the furnace over the platform and dissapear ay the hotter walls. It the case of gallium and indium atomization, the effects of chemical reactions between the vapor and the walls of the furnace on the formation of absorbing layers are stronger than that of diffusion and convective mass-transfer processes, which are common to all of the elements. Atom propagation from the center to the stomizer ends proceeds through the cascade mechanism because of its relatively low rate of warming up and strong longitudinal anisothermicity

  20. Absorption and Recurrence Spectra of Sodium Rydberg Atom in a Strong External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    WANGDe-Hua; LINSheng-Lu

    2004-01-01

    Using core-scattered closed-orbit theory, we calculate the photoabsorption and the scaled recurrence spectra of sodium Rydberg atom in strong magnetic fied below ionization threshoM. The non-Coulombic nature of the ionic core have been modified by a model potential, which includes an attractive Coulomb potential and a short-ranged core potential. A family of core-scattered nonhydrogenic closed orbits have also been discovered. The Fourier transformed spectra of sodium atom have allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The new peaks in the recurrence spectra of sodium atom have been considered as effects caused by the core scattering of returning waves at the ionic core. The results are compared with those of hydrogen case, which show that the core-scattered effects play an important role in alkali-metal atoms.

  1. Absorption and Recurrence Spectra of Sodium Rydberg Atom in a Strong External Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    WANG De-Hua; LIN Sheng-Lu

    2004-01-01

    Using core-scattered closed-orbit theory, we calculate the photoabsorption and the scaled recurrence spectra of sodium Rydberg atom in strong magnetic field below ionization threshold. The non-Coulombic nature of the ionic core have been modified by a model potential, which includes an attractive Coulomb potential and a short-ranged core potential. A family of core-scattered nonhydrogenic closed orbits have also been discovered. The Fourier transformed spectra of sodium atom have allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The new peaks in the recurrence spectra of sodium atom have been considered as effects caused by the core scattering of returning waves at the ionic core. The results are compared with those of hydrogen case, which show that the core-scattered effects play an important role in alkali-metal atoms.

  2. Cosmology with intensity mapping techniques using atomic and molecular lines

    CERN Document Server

    Fonseca, José; Santos, Mário G; Cooray, Asantha

    2016-01-01

    We present a systematic study of the intensity mapping technique using updated models for the different emission lines from galaxies and identify which ones are more promising for cosmological studies of the post reionization epoch. We consider the emission of ${\\rm Ly\\alpha}$, ${\\rm H\\alpha}$, H$\\beta$, optical and infrared oxygen lines, nitrogen lines, CII and the CO rotational lines. We then identify that ${\\rm Ly\\alpha}$, ${\\rm H\\alpha}$, OII, CII and the lowest rotational CO lines are the best candidates to be used as IM probes. These lines form a complementary set of probes of the galaxies emission spectra. We then use reasonable experimental setups from current, planned or proposed experiments to access the detectability of the power spectrum of each emission line. Intensity mapping of ${\\rm Ly\\alpha}$ emission from $z=2$ to 3 will be possible in the near future with HETDEX, while far-infrared lines require new dedicated experiments. We also show that the proposed SPHEREx satellite can use OII and ${\\r...

  3. Ultratrace determination of tin by hydride generation in-atomizertrapping atomic absorption spectrometry

    Czech Academy of Sciences Publication Activity Database

    Průša, Libor; Dědina, Jiří; Kratzer, Jan

    2013-01-01

    Roč. 804, DEC (2013), s. 50-58. ISSN 0003-2670 R&D Projects: GA ČR(CZ) GPP206/11/P002 Grant ostatní: GA MŠk(CZ) MSM0021620857 Institutional support: RVO:68081715 Keywords : hydride generation * tin preconcentration * in-atomizer trapping * trap-and-atomizer device * stannane Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.517, year: 2013

  4. Determination of Heavy Metals in Meat, Intestine, Liver, Eggs, and Chicken Using Neutron Activation Analysis and Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    The elements As, Cd, Co, Cr, Fe, Hg, Ni, Pb, Sb, se and Zn in meat, intestine, and liver of cow and goat, as well as in broiler, local breed chicken and eggs have been determined using Neutron Activation Analysis and Atomic Absorption Spectrometry. Mercury was determined after being separated radiochemically. The results showed that concentration of the essential elements studied i.e. Cr, Cu, Fe, Zn, Co, and Ni were higher in liver and intestine than in the meat, but still in the normal range, while toxic elements As, Cd, and Pb were undetectable in all samples. (author). 8 refs., 6 tabs

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

    OpenAIRE

    Mehran M.; Jafari S; Mohammadi Bassir M.

    2009-01-01

    "nBackground and Aim: Black staining after taking iron drops on the primary teeth is always concern of parents. There is not an exact explanation for the mechanism of iron black staining. The purpose of this study was to compare tooth discolorations, atomic absorption and structural changes of primary teeth enamel caused by two kinds of iron drops[ Kharazmi(Iran) and Fer-in-sol(USA)]. "nMaterials and Methods: In this ex-vivo study, 93 sound primary teeth in normal color range were d...

  6. Evaluation of emery dust on the manufacture of abrasives by neutron activation analysis and atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    In this work it is presented an evaluation on the degree of contamination by emery dust in a working area where abrasives are manufactured, in a factory located in the industrial area of Toluca City by neutron activation analysis and atomic absorption spectroscopy. The samples were collected on Whatman filters and attacked with hot concentrated HCl. The elements founded were: Al, Si, V, Mg, Br, Mn, Ni, Zn, Fe, Cr, Ca and Pb. They are a risk for the health of the workers. (Author)

  7. Determination of Hg(II) as a pollutant in Karachi coastal waters by cold vapor atomic absorption spectroscopy

    International Nuclear Information System (INIS)

    Now a days, environmental monitoring has great importance and mercury is well known for its toxicity. Mercury (which is at trace level) is analyzed by cold vapor atomic absorption spectroscopy with amendments that are appropriate to the present laboratory need. The results are consistent with previous analysis, through other methods, two areas namely Ibrahim Hyderi and Fisheries were found to have mercury levels around 0.193 mu/L and 0.110 mu g/L, respectively. Whereas other areas have mercury levels similar to other places reported earlier. (author)

  8. Flow injection sorbent extraction of metals with activated carbon and its application to flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    In the present study activated carbon was used as a sorbent material for the flow injection on-line sorbent extraction of metal ions combined with atomic absorption spectrometry. On-line chelation of zinc was performed with 8-Hydroxyquinoline and the resultant metal chelate was adsorbed on the activated carbon, then adsorbed with zinc acid and on-line detected with flame AAS. Various parameters affecting the zinc enrichment were optimized and the method was applied for the determination of zinc in tap water, natural water, boiled and tea samples. The results obtained with the present method were compared with those obtained by the ICP-AES. (author)

  9. The rapid and precise determination of noble metals in matte-leach residues by atomic-absorption spectrophotometry

    International Nuclear Information System (INIS)

    A method is proposed for the rapid analysis of platinum-group metals and gold in matte-leach residues. So that the precision of the atomic-absorption measurement is ensured, many measurements are taken (a chart recorder being used) and the calculation is done on a computer. The dissolution of samples was investigated and optimized. Iridium, which is usually present as a minor constituent, is treated on a separate aliquot portion that is concentrated before measurement. The precision of the method ranges from 0,5 per cent for platinum to 2,3 per cent for iridium

  10. Determination of Gd, Sm, Eu and Dy in uranium compounds by atomic absorption spectrophotometry using a graphite furnace

    International Nuclear Information System (INIS)

    The separation of Gd, Sm, Eu and Dy from uranium and its determination by graphite furnace atomic absorption spectrophotometry is outlined. The lanthanides were separated by means of the percolation of the uranyl nitrate solution 0,3 M in HF (50-250g of U3O8 perliter) through an Al2O3 column. The lanthanides retained in the column were eluted with 1M HCl. As thorium is also retained into the column under these conditions, its interference was studied. The determination limits of the method range from 0,01 to 0,1 μg of lanthanide per gram of uranium. (Author)

  11. Combination of cloud point extraction and flame atomic absorption spectrometry for preconcentration and determination of nickel and manganese ions in water and food samples

    International Nuclear Information System (INIS)

    A simple, rapid, inexpensive, and nonpolluting cloud point extraction (CPE) technique has been improved for the preconcentration and determination of nickel and manganese. After complexation with p-nitrophenylazoresorcinol (Magneson I), the analytes could be competitively extracted in a surfactant octylphenoxy polyethoxyethanol (Triton X-114), prior to determination by flame atomic absorption spectrometry (FAAS). The effects of experimental conditions such as pH, concentration of chelating agent and surfactant, equilibration temperature and time on CPE were studied. Under the optimum conditions, preconcentration of a 25 mL sample solution permitted the detection of 2.7 ng mL-1 Ni2+ and 2.9 ng mL-1 Mn2+ with enrichment factors of 17 and 19 for Ni2+ and Mn2+, respectively. The developed method was applied to the determination of trace nickel and manganese in water and food samples with satisfactory results.

  12. Application of High Resolution-Continuum Source Flame Atomic Absorption Spectrometry (HR-CS FAAS): determination of trace elements in tea and tisanes.

    Science.gov (United States)

    Paz-Rodríguez, Beatriz; Domínguez-González, María Raquel; Aboal-Somoza, Manuel; Bermejo-Barrera, Pilar

    2015-03-01

    A new application of HR-CS FAAS (High Resolution-Continuum Source Flame Atomic Absorption Spectrometry) has been developed for the determination of several trace elements (Ca, Co, Cu, Fe, Mn, Ni, Na and Zn) in infusions made from tea, rooibos and tea with seaweed samples. The proposed methods are fast, inexpensive and show good performances: the mean analytical recovery was approximately 100%. The mean limit of detection was 29.4 μg/l, and the mean limit of quantification was 98.0 μg/l (both limits refer to the brewed samples). Due to the matrix effect observed, the standard addition method had to be applied. Preliminary classification (based on metal contents) using chemometric techniques such as PCA (Principal Component Analysis) and CA (Cluster Analysis), was successful for infusions made from rooibos and tea with seaweed, but inconclusive for black and green teas. PMID:25306375

  13. Studies on Elemental Contents of Some Biological and Environmental Materials Using Nuclear And Atomic Techniques

    International Nuclear Information System (INIS)

    The elemental concentration values of 31 elements in the fertilizer samples, have been determined by applying a sensitive nondestructive analytical techniques such as INAA. It has also shown enough sensitivity to determine the concentrations of several trace and rare earth elements, The concentration values of elements were compared with the corresponding elements obtained by the ICP-MS and XRF techniques, for the same samples. Phosphorus fertilizers contain varying amounts of heavy metals and other rare earth elements as contaminants from either phosphate rock ores or other ingredients used in the phosphate fertilizer industry. As some heavy metals are potentially harmful to human health, attention is being given to its avenues of entry into the human food chain. Uptake of such elements by plants consumed directly or indirectly by humans is one avenue of entry, so the effects of heavy metal contaminants in phosphate fertilizers are of concern. Commercial fertilizers have been used for decades and will probably continue to be used for many decades to come. Hence, even low annual accumulations may finally build up undesired concentrations in soil, especially where fertilizers with high heavy metal or rare earth element concentrations are used.Thus, a total of three synthetic and natural eye-liner samples of known origin that are commercially available in the Egyptian market were analyzed using Energy Dispersive X-ray (EDX), Atomic Absorption Mass Spectroscopy (AA-MS) and elemental analysis using Thermal Neutron Activation Technique (TNAT) for the natural one in powder form. It was found that lead (>86%) represents the main hazardous element in the natural eye-liner from African sources. Aluminum and Antimony were also found in the later sample in considerable concentration 0.92% and 0.71% respectively. For the synthetic two samples from French and American sources, the major hazardous element found to be Carbon in high concentration 94% and 52% respectively. The

  14. Determination of selected metals in urban runoff and related estuarine sediments by neutron activation and atomic absorption

    International Nuclear Information System (INIS)

    Pollution sources for Newport Bay, California are of a nonpoint nature. To assess the heavy metals loading of the runoff into the Bay, 18 water samples, taken during dry and rainy periods, have been analyzed for Mn, Cu, Zn, and Pb, using atomic absorption spectrometry (AAS). In addition, 7 sediment cores from the Upper Bay and 5 sediment grab samples from the Lower Bay were analyzed for Cr, Mn, Fe, Co, Cu, Zn, and Pb. Instrumental neutron activation analysis (INAA) was used for Cr, Fe, and Co, whereas Mn, Cu, and Pb were determined by AAS. Zinc was determined by both of these techniques. Three major streams pass into Newport Bay carrying: (1) agricultural and to some extent urban and residential runoff (70-90%), (2) urban runoff (10-30%), and (3) residential runoff (<5%). The levels of Zn and Pb are much higher under storm conditions, e.g., 338 μg/l Zn and 425 μg/l Pb, than during dry weather, where typical concentrations are 20 μg/l Zn and 9 μg/l Pb. For Cu there is a moderate increase from about 10 μg/l in dry weather to a maximum of 54 μg/l under storm conditions. Soil erosion appears to be responsible for high Mn values (max. 1230 μg/l) in agricultural storm runoff. The cleansing action of a storm is evidenced by high concentrations in the beginning, and much lower levels towards the end of the storm.Vertical profiles of heavy metals in sediment cores indicate that Zn and Pb are the only metals of those investigated that show clearly increased levels in the uppermost layers. Typical enrichment ratios are 2.0 for Zn and 5.5 for Pb. Maximum concentrations of Zn and Pb in sediments from the Upper Bay were 300 ppm and 132 ppm, respectively. The highest Pb value was found close to the mouth of the urban drainage channel. Dating of selected cores was carried out by the Pb-210 method. Mass injection rates into Upper Newport Bay for Zn and Pb of anthropogenic origin were estimated to be 6.0 and 6.5 tons/yr, respectively

  15. [Carbon monoxide gas detection system based on mid-infrared spectral absorption technique].

    Science.gov (United States)

    Li, Guo-Lin; Dong, Ming; Song, Nan; Song, Fang; Zheng, Chuan-Tao; Wang, Yi-Ding

    2014-10-01

    Based on infrared spectral absorption technique, a carbon monoxide (CO) detection system was developed using the fundamental absorption band at the wavelength of 4.6 μm of CO molecule and adopting pulse-modulated wideband incandescence and dual-channel detector. The detection system consists of pulse-modulated wideband incandescence, open ellipsoid light-collec- tor gas-cell, dual-channel detector, main-control and signal-processing module. By optimizing open ellipsoid light-collector gas- cell, the optical path of the gas absorption reaches 40 cm, and the amplitude of the electrical signal from the detector is 2 to 3 times larger than the original signal. Therefore, by using the ellipsoidal condenser, the signal-to-noise ratio of the system will be to some extent increased to improve performance of the system. With the prepared standard CO gas sample, sensing characteris- tics on CO gas were investigated. Experimental results reveal that, the limit of detection (LOD) is about 10 ppm; the relative er- ror at the LOD point is less than 14%, and that is less than 7. 8% within the low concentration range of 20~180 ppm; the maxi- mum absolute error of 50 min long-term measurement concentration on the 0 ppm gas sample is about 3 ppm, and the standard deviation is as small as 0. 18 ppm. Compared with the CO detection systems utilizing quantum cascaded lasers (QCLs) and dis- tributed feedback lasers (DFBLs), the proposed sensor shows potential applications in CO detection under the circumstances of coal-mine and environmental protection, by virtue of high performance-cost ratio, simple optical-path structure, etc. PMID:25739235

  16. The 21-SPONGE HI Absorption Survey I: Techniques and Initial Results

    CERN Document Server

    Murray, Claire E; Goss, W M; Dickey, John M; Heiles, Carl; Lindner, Robert R; Babler, Brian; Pingel, Nickolas M; Lawrence, Allen; Jencson, Jacob; Hennebelle, Patrick

    2015-01-01

    We present methods and results from "21-cm Spectral Line Observations of Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With the upgraded capabilities of the VLA, we reach median root-mean-square (RMS) noise in optical depth of $\\sigma_{\\tau}=9\\times 10^{-4}$ per $0.42\\rm\\,km\\,s^{-1}$ channel for the 31 sources presented here. Upon completion, 21-SPONGE will be the largest HI absorption survey with this high sensitivity. We discuss the observations and data reduction strategies, as well as line fitting techniques. We prove that the VLA bandpass is stable enough to detect broad, shallow lines associated with warm HI, and show that bandpass observations can be combined in time to reduce spectral noise. In combination with matching HI emission profiles from the Arecibo Observatory ($\\sim3.5'$ angular resolution), we estimate excitation (or spin) temperatures ($\\rm T_s$) and column densities for Gaussian componen...

  17. Green method for ultrasensitive determination of Hg in natural waters by electrothermal-atomic absorption spectrometry following sono-induced cold vapor generation and 'in-atomizer trapping'

    International Nuclear Information System (INIS)

    Sono-induced cold vapor generation (SI-CVG) has been used for the first time in combination with a graphite furnace atomizer for determination of Hg in natural waters by electrothermal-atomic absorption spectrometry after in situ trapping onto a noble metal-pretreated platform (Pd, Pt or Rh) inserted into a graphite tube. The system allows 'in-atomizer trapping' of Hg without the use of conventional reduction reactions based on sodium borohydride or tin chloride in acid medium for cold vapor generation. The sono-induced reaction is accomplished by applying ultrasound irradiation to the sample solution containing Hg(II) in the presence of an organic compound such as formic acid. As this organic acid is partly degraded upon ultrasound irradiation to yield CO, CO2, H2 and H2O, the amount of lab wastes is minimized and a green methodology is achieved. For this purpose, experimental variables influencing the generation/trapping process are fully investigated. The limit of detection for a 10 min trapping time and 10 mL sample volume was 0.03 μg L-1 (Integrated absorbance) and the repeatability expressed as relative standard deviation was about 3%. Carbonates and chlorides at 100 mg L-1 level caused a signal depression by 20-30%. The enhanced trapping efficiency observed with the sono-induced cold vapor generation as compared with 'in-atomizer trapping' methods employing chemical vapor generation is discussed. A reaction pathway for SI-CVG is proposed on the basis of the current knowledge for synthesis of noble metal nanoparticles by ultrasound

  18. Column system using diaion HP-2MG for determination of some metal ions by flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tuzen, Mustafa; Soylak, Mustafa

    2004-02-23

    A column solid-phase extraction method for the preconcentration and determination of cadmium(II), copper(II), cobalt(II), iron(III), lead(II), nickel(II) and zinc(II) dithizone chelates by atomic absorption spectrometry has been described. Diaion HP-2MG was used as adsorbent for column studies. The influences of the various analytical parameters including pH of the aqueous solutions, amounts of ligand and resin were investigated for the retentions of the analyte ions. The recovery values are ranged from 95 to 102%. The influences of alkaline and earth alkaline ions were also discussed. The preconcentration factor was 375, when the sample volume and final volume are 750 and 2 ml, respectively. The detection limits of the analyte ions (k=3, N=21) were varying 0.08 {mu}g/l for cadmium to 0.25 {mu}g/l for lead. The relative standard deviations of the determinations at the concentration range of 1.8x10{sup -4} to 4.5x10{sup -5} mmol for the investigated elements were found to be lower than 9%. The proposed solid-phase extraction procedure were applied to the flame atomic absorption spectrometric determinations of analyte ions in natural waters (sea, tap, river), microwave digested samples (milk, red wine and rice) and two different reference standard materials (SRM1515 apple leaves and NRCC-SLRS-4 riverine water)

  19. The determination of caesium and silver in soil and fungal fruiting bodies by electrothermal atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Methods have been developed for the determination of caesium and silver in soil and fungal samples by microwave-assisted aqua regia digestion, followed by electrothermal atomic absorption spectrometry. The procedure was found to be repeatable (for soil, RSD -1, respectively, and for fungi, RSD -1, respectively) and reasonably efficient. Silver was recovered quantitatively from reference soils, but only about 80-85% of the caesium present could be extracted. Poorer caesium recoveries (< 70%) were obtained if, as part of the sample preparation procedure, solutions were taken to dryness in glass beakers prior to analysis. The detection limits were 0.02 mg Ag and 0.09 mg Cs per gram of dry soil, which are adequate for the determination of the analytes at typical environmental levels. The methods were applied in the analysis of three types of soil, a peaty podzol, a clay loam and a sandy loam and no significant matrix interferences were observed except in the determination of caesium in the sandy loam. For caesium, non-linear response curves, thought to be due to ionisation interference, were encountered using one atomic absorption spectrometer, but were not observed with the other instrument

  20. 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

  1. Determination of U and Impurities Elements in The Uranium Tetra Fluoride by Potentiometric and Atomic Absorption Spectrophotometric Methods

    International Nuclear Information System (INIS)

    The determination of u and impurities contents in the Uranium tetra fluoride (UF4)has been carried out by potentiometric titration using modified 'Davies-Gray' and atomic absorption spectrophotometric methods. Dissolution process of the powder sample using saturated Al2(SO4)3 solution introduced to determine UF4 compound content in the UF4 sample. The uranium Content in the obtained filtrate is analyzed by potentiometric. The impurities content is determined by ato-Mic absorption spectrophotometric using ammonium oxalate powder in introducing of the sample preparation. The experiment covered the observation on influence of stirring time of UF4 sample dissolution in respect to separate UF4 from its impurities in determination of uranium content. Also the effects of Ammonium Oxalate added and agitating time were observed deal with the sample preparation for the determination of Impurities content.The analysis result found that UF4 content was 96.15 ± 0.04% the relative station 0.7%. However the best impurities determination was achieved by addition of ammonium oxalate powder and 15 Minutes of agitation time at temperature of 8000C

  2. A Literature Study of Matrix Element Influenced to the Result of Analysis Using Absorption Atomic Spectroscopy Method (AAS)

    International Nuclear Information System (INIS)

    The gold sample analysis can be deviated more than >10% to those thrue value caused by the matrix element. So that the matrix element character need to be study in order to reduce the deviation. In rock samples, the matrix elements can cause self quenching, self absorption and ionization process, so there is a result analysis error. In the rock geochemical process, the elements of the same group at the periodic system have the tendency to be together because of their same characteristic. In absorption Atomic Spectroscopy analysis, the elements associate can absorb primer energy with similar wave length so that it can cause deviation in the result interpretation. The aim of study is to predict matrix element influences from rock sample with application standard method for reducing deviation. In quantitative way, assessment of primer light intensity that will be absorbed is proportional to the concentration atom in the sample that relationship between photon intensity with concentration in part per million is linier (ppm). These methods for eliminating matrix elements influence consist of three methods : external standard method, internal standard method, and addition standard method. External standard method for all matrix element, internal standard method for elimination matrix element that have similar characteristics, addition standard methods for elimination matrix elements in Au, Pt samples. The third of standard posess here accuracy are about 95-97%. (author)

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

    Science.gov (United States)

    Satija, Aman; Lucht, Robert P.

    2015-06-01

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

  4. Absorption spectrum of the excitons bound on neutral boron atoms in cubic silicon carbide

    International Nuclear Information System (INIS)

    Absorption spectrum of the excitons strongly bound on neutral deep acceptors (boron) is observed for the first time in silicon carbide 3C-SiC:B cubic crystals. The exciton binding energy with EBex acceptor equals 227 meV. The spectrum consists of three absorption lines at photon energies 2.1508; 2.1585 and 2.189 eV and a series of high energy maxima. The spectrum structure is explained by splitting of coupled exciton states by hole-hole exchange interaction in the local acceptor field. It is shown that because of extremely high probability of Auger-processes the decay of excitons bound on neutral boron in 3C-SiC is a radiationless one

  5. Profile of arsenicals in newborn mouse brain by hydride generation- cryotrapping-atomic absorption

    Czech Academy of Sciences Publication Activity Database

    Sánchez-Peña, L. C.; Matoušek, Tomáš; Dědina, Jiří; Gonsebatt, M. E.; Ramos, L.; Del Razo, L. M.

    2014. s. 171-171. [Rio Symposium on Atomic Spectrometry /13./. 19.10.2014-24.10.2014, Merida, Yucatan] R&D Projects: GA AV ČR(CZ) 004MX2011 Institutional support: RVO:68081715 Keywords : Arsenic * speciation * brain Subject RIV: CB - Analytical Chemistry, Separation

  6. Study of the effect of Chinese medicine on calcium absorption with isotopic tracer technique

    International Nuclear Information System (INIS)

    The present work was undertaken to study the effect of Chinese medicine on calcium absorption. Female Wistar rats, 3 months old, weighing 250-275 g, were randomly divided into ten groups of 5 rats each. The rats were individually housed in stainless steel metabolic cages in an environmentally controlled room (temperature, 20 degree C; relative humidity, 30%-60%; reversed light : dark cycle, 12:12 hr). Isotopic tracer technique was conducted to study the absorption of calcium acetate and calcium acetate + Chinese medicine in rats. The two calcium supplements were irradiated in a nuclear reactor for 4.95 d at neutron flux of φ=6.1 x 1013 n/cm2·s. Then they were prepared from concentrated 47Ca solution (10 mg/ml) with cyclodextrin. The animals received oral doses of 25 mg calcium as calcium acetate or calcium acetate + Chinese medicine via an intragastric gavage. The animals were fasted overnight preceding and food was resumed 3 hrs after the gavage. Blood, heart, lung, liver, spleen, stomach, kidney, small intestine, large intestine and femur samples of the rats were taken upon sacrifice at 0.5, 1, 2, 4, 12, 24, 48, 72, 120, 168 hrs after dosing and assayed for 47Ca. Urine and feces samples were collected separately after dosing and assayed for 47Ca. The radioactivity of the samples was counted with a high pure Ge detector and a PC-based Ortec MCA. Its energy resolution was l.85 keV at 1332.5 keV and the relative detection efficiency was 30 %. The dead time was controlled within 10 % to reduce the count loss. Weighed 47CaCO3 was used as reference materials. A big distance between the samples and detector was kept to overcome the geometric effect caused by different shape and size of the samples. The gamma energy spectra were analyzed with a multipurpose gamma ray spectrum analysis software package. The parameters were evaluated by means of general linear model, using analysis of covariance with SAS 6.12 for Windows. The results showed that peroral 47Ca was mainly

  7. X-ray absorption study of the local electronic and atomic structure of the ferrohexacyanide anion Fe(CH)64-

    International Nuclear Information System (INIS)

    The near fine structure of K spectra of nitrogen and carbon atoms and of L2,3 absorption spectra of iron and potassium atoms in a solid-state ferrohexacyanide K4Fe(CN)6 is studied by the method of the quantum yield of the external photoelectric effect with an RSM-500 X-ray spectrometer-monochromator and bremsstrahlung from an X-ray tube with a tungsten cathode. The resonant features of the spectra obtained and and of the FeK spectrum known from the literature are identified within the framework of the extended quasi-molecular approach using a comparative analysis of the absorption NK and CK spectra of the complex Fe(CN)64- anion and free HCN molecule and also general quantum-chemical considerations about the nature of theFe-6(CN) in the complex in order to take into account the effect of this interaction on the formation of a general spectrum of the resonance excited states of the complex. As a result of the analysis performed, all form resonances are identified based on transitions of core electrons to vacant molecular orbitals (MO), the symmetry of these MOs and their energies relative the highest filled MO of the complex are determined, and the region of spatial localization of each resonance is found. It is established that the lowest vacant MO of the complex is mainly formed from the antibonding 2π orbitals of CN- ligands. By treating π and σ resonances strongly localized at ligands as a result of splitting of the 1s → 2p atomic resonance in the absorption K spectra of nitrogen and carbon atoms caused by the anisotropic molecular field of the CN- anion, the interatomic distance d(C-N) = 1.09 Angstrom, which is ambiguously estimated from other experimental methods, is found for the FE(CN)64- complex from the values of splitting ΔE(π-σ) in spectra of HCN and H3CNO2 molecules and this complex. 67 refs., 5 figs., 2 tabs

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

    International Nuclear Information System (INIS)

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

  9. Kinetic and Diagnostic Studies of Molecular Plasmas Using Laser Absorption Techniques

    International Nuclear Information System (INIS)

    Within the last decade mid infrared absorption spectroscopy between 3 and 20 μm, known as Infrared Laser Absorption Spectroscopy (IRLAS) and based on tuneable semiconductor lasers, namely lead salt diode lasers, often called tuneable diode lasers (TDL), and quantum cascade lasers (QCL) has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has lead to further applications of IRLAS because most of these compounds and their decomposition products are infrared active. IRLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetics. Information about gas temperature and population densities can also be derived from IRLAS measurements. A variety of free radicals and molecular ions have been detected, especially using TDLs. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of QCLs offers an attractive new option for the monitoring and control of industrial plasma processes as well as for highly time-resolved studies on the kinetics of plasma processes. The aim of the present article is threefold: (i) to review recent achievements in our understanding of molecular phenomena in plasmas (ii) to report on selected studies of the spectroscopic properties and kinetic behaviour of radicals, and (iii) to describe the current status of advanced instrumentation for TDLAS in the mid infrared

  10. Spectral fluorescence signature techniques and absorption measurements for continuous monitoring of biofuel-producing microalgae cultures

    Science.gov (United States)

    Martín de la Cruz, M. C.; Gonzalez Vilas, L.; Yarovenko, N.; Spyrakos, E.; Torres Palenzuela, J. M.

    2013-08-01

    Biofuel production from microalgae can be both sustainable and economically viable. Particularly in the case of algal growth in wastewater an extra benefit is the removal or biotransformation of pollutants from these types of waters. A continuous monitoring system of the microalgae status and the concentration of different wastewater contaminants could be of great help in the biomass production and the water characterisation. In this study we present a system where spectral fluorescence signature (SFS) techniques are used along with absorption measurements to monitor microalgae cultures in wastewater and other mediums. This system aims to optimise the microalgae production for biofuel applications or other uses and was developed and tested in prototype indoor photo-bioreactors at the University of Vigo. SFS techniques were applied using the fluorescence analyser INSTAND-SCREENER developed by Laser Diagnostic Instruments AS. INSTAND-SCREENER permits wavelength scanning in two modes, one in UV and another in VIS. In parallel, it permits the on-line monitoring and rapid analysis of both water quality and phytoplankton status without prior treatment of the sample. Considering that different contaminants and microalgae features (density, status etc.) have different spectral signatures of fluorescence and absorption properties, it is possible to characterise them developing classification libraries. Several algorithms were used for the classification. The implementation of this system in an outdoor raceway reactor in a Spanish wastewater treatment plant is also discussed. This study was part of the Project EnerBioAlgae (http://www.enerbioalgae.com/), which was funded by the Interreg SUDOE and led by the University of Vigo.

  11. Chemical vapor generation of silver for atomic absorption spectrometry with the multiatomizer: Radiotracer efficiency study and characterization of silver species

    International Nuclear Information System (INIS)

    Volatile Ag species were generated in flow injection arrangement from nitric acid environment in the presence of surfactants (Triton X-100 and Antifoam B) and permanent Pd deposits as the reaction modifiers. Atomic absorption spectrometry (AAS) with multiple microflame quartz tube atomizer heated to 900 deg. C was used for atomization; evidence was found for thermal mechanism of atomization. Relative and absolute limits of detection (3σ, 250 μl sample loop) measured under optimized conditions were: 1.4 μg l-1 and 0.35 ng, respectively. The efficiency of chemical vapor generation (CVG) as well as spatial distribution of residual analyte in the apparatus was studied by 111Ag radioactive indicator (half-life 7.45 days) of high specific activity. It was found out that 23% of analyte was released into the gaseous phase. However, only 8% was found on filters placed at the entrance to the atomizer due to transport losses. About 40% of analyte remained in waste liquid, whereas the rest was found deposited over the CVG system. Presented study follows the hypothesis that the 'volatile' Ag species are actually metallic nanoparticles formed upon reduction in liquid phase and then released with good efficiency to the gaseous phase. Number/charge size distributions of dry aerosol were determined by Scanning Mobility Particle Sizer. Ag was detected in 40-45 nm particles holding 10 times more charge if compared to Boltzmann equilibrium. At the same time, Ag was also present on 150 nm particles, the main size mode of the CVG generator. The increase of Ag in standards was reflected by proportional increase in particle number/charge for 40-45 nm size particles only. Transmission electron microscopy revealed particles of 8 ± 2 nm sampled from the gaseous phase, which were associated in isolated clusters of few to few tens of nanometres. Ag presence in those particles was confirmed by Energy Dispersive X-ray Spectroscopy (EDS) analysis.

  12. A novel analytical system involving hydride generation and gold-coated W-coil trapping atomic absorption spectrometry for selenium determination at ng l-1 level

    International Nuclear Information System (INIS)

    A novel analytical technique was developed where gaseous hydrogen selenide formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated W-coil atom trap for in situ preconcentration. Gold coating on W-coil was prepared by using an organic solution of Au. The atom trap is held at 165 oC during the collection stage and is heated up to 675 deg. C for revolatilization; analyte species formed are transported to an externally heated quartz T-tube where the atomization takes place and the transient signal is obtained. The carrier gas consisted of 112.5 ml min-1 Ar with 75 ml min-1 H2 during the collection step and 112.5 ml min-1 Ar with 450 ml min-1 H2 in the revolatilization step. The half width of the transient signal obtained is less than 0.5 s. The RSD for the measurements was found to be 3.9% (n = 11) for 0.10 μg l-1 Se using peak height measurements. The calibration plot for 27.0 ml of sample collected in 4.0 min using a flow rate of 6.75 ml min-1 was linear between 0.13 and 2.0 μg l-1 of Se. The limit of detection (3 s) is 39 ng l-1. The enhancement factor for the characteristic concentration (Co) was found to be 20.1 when compared to conventional hydride generation atomic absorption spectrometry system without trap. In order to check the accuracy of the method, standard reference material, natural water NIST 1640 was employed; the result was found to be in good agreement with the certified value at the 95% confidence level

  13. Atomic and molecular physics using positron accumulation techniques - Summary and a look to the future

    International Nuclear Information System (INIS)

    An overview is presented of current techniques to accumulate and cool large numbers of positrons from a radioactive 22Na source and neon moderator, and the first operation of a new generation of positron accumulator is described. Experiments are discussed that use these techniques to study the interaction of positrons with atoms and molecules at low energies (i.e., below the threshold for positronium formation), including systematic studies of the dependence of positron annihilation on chemical composition. By measuring the Doppler-broadening of gamma-ray annihilation radiation, the quantum state of the annihilating electrons in atoms and molecules was identified. These experiments indicate that positrons annihilate with approximately equal probability on any valence electron. Annihilation with inner shell electrons is infrequent, but is measurable at the level of a few percent in heavier atoms. Measurements of annihilation rates in molecules as a function of positron temperature revealed a number of interesting trends that are briefly discussed. We have developed a new technique to make a cold, bright positron beam. This technique is now being used for a new generation of scattering experiments in the range of energies ≤1 eV. Other possible experiments to study aspects of atomic and molecular physics using positron accumulation techniques and this cold positron beam are briefly discussed

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

    Science.gov (United States)

    Gökmen, A.; Yalcin, S.

    1992-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-22

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

  16. Graphite furnace atomic absorption spectrometry as a routine method for the quantification of beryllium in blood and serum

    Directory of Open Access Journals (Sweden)

    Brousseau Pauline

    2008-07-01

    Full Text Available Abstract Background A routine method for the quantification of beryllium in biological fluids is essential for the development of a chelation therapy for Chronic Beryllium Disease (CBD. We describe a procedure for the direct determination of beryllium in undigested micro quantities of human blood and serum using graphite furnace atomic absorption spectrometry. Blood and serum samples are prepared respectively by a simple 8-fold and 5-fold dilution with a Nash Reagent. Three experimental setups are compared: using no modifier, using magnesium nitrate and using palladium/citric acid as chemical modifiers. Results In serum, both modifiers did not improve the method sensitivity, the optimal pyrolysis and atomization temperatures are 1000°C and 2900°C, respectively. In blood, 6 μg of magnesium nitrate was found to improve the method sensitivity. The optimal pyrolysis and atomization temperatures were 800°C and 2800°C respectively. Conclusion In serum, the method detection limit was 2 ng l-1, the characteristic mass was 0.22 (± 0.07 pg and the accuracy ranged from 95 to 100%. In blood, the detection limit was 7 ng l-1, the characteristic mass was 0.20 (± 0.02 pg and the accuracy ranged from 99 to 101%.

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

    International Nuclear Information System (INIS)

    In this work, several analytical methods are proposed for cadmium determination in Orujo spirit samples using electrothermal atomic absorption spectrometry (ETAAS). Permanent chemical modifiers thermally coated on the platforms inserted in pyrolytic graphite tubes (such as W, Ir, Ru, W-Ir and W-Ru) were comparatively studied in relation to common chemical modifier mixtures [Pd-Mg(NO3)2 and (NH4)H2PO4-Mg(NO3)2] for cadmium stabilization. Different ETAAS Cd determination methods based on the indicated modifiers have been developed. In each case, pyrolysis and atomization temperatures, atomization shapes, characteristic masses and detection limits as well as other analytical characteristics have been determined. All the assayed modifiers (permanent and conventional) were capable of achieving the appropriate stabilization of the analyte, with the exception of Ru and W-Ru. Moreover, for all developed methods, recoveries (99-102%) and precision (R.S.D. lower than 10%) were acceptable. Taking into account the analytical performance (best detection limit LOD = 0.01 μg L-1), the ETAAS method based on the use of W as a permanent modifier was selected for further direct Cd determinations in Orujo samples from Galicia (NW Spain). The chosen method was applied in the determination of the Cd content in 38 representative Galician samples. The cadmium concentrations ranged -1

  18. [Determination of aluminum in wheat flour food by microwave digestion-high resolution continuum source graphite furnace atomic absorption spectrometry].

    Science.gov (United States)

    Ren, Ting; Zhao, Li-jiao; Zhong, Ru-gang

    2011-12-01

    The contents of aluminum (Al) in four kinds of wheat flour food (noodle, dumpling wrapper, twisted cruller and soda biscuit) were determined by high resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) combined with microwave digestion. The samples were completely digested by the mixture of HNO3 and H2O2 in closed polytetrafluoroethylene (PTFE) vessels. The conditions for microwave digestion, pyrolysis temperature and atomization temperature were optimized. The optimum experimental conditions were determined as follows. The microwave digestion was performed with HNO3/H2O2 7:1 (volume ratio), microwave power 1000 W and 190 degrees C for 40 minutes. The optimum pyrolysis temperature was 1350 degrees C and the optimum atomization temperature was 2400 degrees C. Magnesium nitrate solution with the concentration of 1 g x L(-1) was used as the matrix modifier. The correlation coefficient for the standard curve was 0.9999, the relative standard deviation (RSD) was from 1.7% to 2.4%, and the recovery for the samples was from 98.16% to 102.67%. The assay method for the determination of Al in wheat flour food established in this study has referential importance for the constituent of the correlated food standards. PMID:22295801

  19. Emission, optical--optical double resonance, and excited state absorption spectroscopy of matrix isolated chromium and molybdenum atoms

    International Nuclear Information System (INIS)

    Making use of a combination of time-resolved emission, optical--optical double resonance, and excited state absorption spectroscopy, it has been possible to assign virtually all spectral features with energies below the z7P0 state of matrix isolated Cr atoms. The a5S state located at 7593 cm-1 in the free gaseous Cr atom has lifetimes of 6.32 and 5.1 s in Ar and Kr matrices, respectively. Matrix perturbations on Cr emission lines are small (-1). The dependence of nonradiative decay rates on the local density of states is elucidated. The magnitude of matrix shifts for a particular transition is correlated with the electronic configurations of ground and excited states and it is pointed out that states having only ''s'' electrons in addition to ''d'' electrons maintain their gas phase energy relationships in the matrix environment. Direct fluorescence is observed from the z7P0 level of Mo to the 7s ground state. The spin-orbit splitting of the ''relaxed'' z7P0 state is 690 cm-1, slightly lower than the 707 cm-1 splitting of the free gaseous Mo atom

  20. Direct determination of P in biodiesel by high-resolution continuum source graphite furnace atomic absorption spectrometry

    International Nuclear Information System (INIS)

    The direct determination of P in biodiesel by high-resolution continuum source graphite furnace atomic absorption spectrometry has been investigated. A slow drying stage proved to be essential for good repeatability. Optimization was performed by a D optimal planning. The atomization temperature and modifier composition were the most relevant parameters. Thus, using a mixture of Pd (30 μg) and Mg(NO3)2 (20 μg) as the modifier, previously deposited onto the platform of the graphite tube and dried, a five step drying stage, and pyrolysis and atomization temperatures of 1000 and 2700 deg. C, respectively, a limit of detection of 0.5 μg g-1 was obtained. The analysis of biodiesel of different origins confirmed that external calibration with organic P standard solutions, diluted in P-free biodiesel, could be used. In this way, excellent agreement between the found and expected results was observed in the analysis of an ANP interlaboratorial exercise sample.