Determination of arsenic in water samples by Total Reflection X-Ray Fluorescence using pre-concentration with alumina

Energy Technology Data Exchange (ETDEWEB)

Barros, Haydn [Laboratorio de Fisica Nuclear, Dpto. De Fisica, Universidad Simon Bolivar, Sartenejas, Baruta (Venezuela, Bolivarian Republic of); Marco Parra, Lue-Meru, E-mail: luemerumarco@yahoo.e [Universidad Centroccidental Lisandro Alvarado, Dpto. Quimica y Suelos, Decanato de Agronomia, Tarabana, Cabudare, Edo.Lara (Venezuela, Bolivarian Republic of); Bennun, Leonardo [Universidad de Concepcion, Concepcion (Chile); Greaves, Eduardo D. [Laboratorio de Fisica Nuclear, Dpto. De Fisica, Universidad Simon Bolivar, Sartenejas, Baruta (Venezuela, Bolivarian Republic of)

2010-06-15

The determination of arsenic in water samples requires techniques of high sensitivity. Total Reflection X-Ray Fluorescence (TXRF) allows the determination but a prior separation and pre-concentration procedure is necessary. Alumina is a suitable substrate for the selective separation of the analytes. A method for separation and pre-concentration in alumina, followed by direct analysis of the alumina is evaluated. Quantification was performed using the Al-K{alpha} and Co-K{alpha} lines as internal standard in samples prepared on an alumina matrix, and compared to a calibration with aqueous standards. Artificial water samples of As (III) and As (V) were analyzed after the treatment. Fifty milliliters of the sample at ppb concentration levels were mixed with 10 mg of alumina. The pH, time and temperature were controlled. The alumina was separated from the slurry by centrifugation, washed with de-ionized water and analyzed directly on the sample holder. A pre-concentration factor of 100 was found, with detection limit of 0.7 {mu}gL{sup -1}. The percentage of recovery was 98% for As (III) and 95% for As (V) demonstrating the suitability of the procedure.

Determination of arsenic in water samples by Total Reflection X-Ray Fluorescence using pre-concentration with alumina

International Nuclear Information System (INIS)

Barros, Haydn; Marco Parra, Lue-Meru; Bennun, Leonardo; Greaves, Eduardo D.

2010-01-01

The determination of arsenic in water samples requires techniques of high sensitivity. Total Reflection X-Ray Fluorescence (TXRF) allows the determination but a prior separation and pre-concentration procedure is necessary. Alumina is a suitable substrate for the selective separation of the analytes. A method for separation and pre-concentration in alumina, followed by direct analysis of the alumina is evaluated. Quantification was performed using the Al-Kα and Co-Kα lines as internal standard in samples prepared on an alumina matrix, and compared to a calibration with aqueous standards. Artificial water samples of As (III) and As (V) were analyzed after the treatment. Fifty milliliters of the sample at ppb concentration levels were mixed with 10 mg of alumina. The pH, time and temperature were controlled. The alumina was separated from the slurry by centrifugation, washed with de-ionized water and analyzed directly on the sample holder. A pre-concentration factor of 100 was found, with detection limit of 0.7 μgL -1 . The percentage of recovery was 98% for As (III) and 95% for As (V) demonstrating the suitability of the procedure.

Synchrotron radiation total reflection for rainwater analysis

International Nuclear Information System (INIS)

Simabuco, Silvana M.; Matsumoto, Edson

1999-01-01

Total reflection X-ray fluorescence analysis excited with synchrotron radiation (SR-TXRF) has been used for rainwater trace element analysis. The samples were collected in four different sites at Campinas City, SP. Standard solutions with gallium as internal standard were prepared for the calibration system. Rainwater samples of 10 μl were putted onto Perspex reflector disk, dried on vacuum and analyzed for 100 s measuring time. The detection limits obtained for K-shell varied from 29 ng.ml -1 for sulfur to 1.3 ng.ml -1 for zinc and copper, while for L-shell the values were 4.5 ng.ml -1 for mercury and 7.0 ng.ml -1 for lead. (author)

Sample preparation for total reflection X-ray fluorescence analysis using resist pattern technique

Science.gov (United States)

Tsuji, K.; Yomogita, N.; Konyuba, Y.

2018-06-01

A circular resist pattern layer with a diameter of 9 mm was prepared on a glass substrate (26 mm × 76 mm; 1.5 mm thick) for total reflection X-ray fluorescence (TXRF) analysis. The parallel cross pattern was designed with a wall thickness of 10 μm, an interval of 20 μm, and a height of 1.4 or 0.8 μm. This additional resist layer did not significantly increase background intensity on the XRF peaks in TXRF spectra. Dotted residue was obtained from a standard solution (10 μL) containing Ti, Cr, Ni, Pb, and Ga, each at a final concentration of 10 ppm, on a normal glass substrate with a silicone coating layer. The height of the residue was more than 100 μm, where self-absorption in the large residue affected TXRF quantification (intensity relative standard deviation (RSD): 12-20%). In contrast, from a droplet composed of a small volume of solution dropped and cast on the resist pattern structure, the obtained residue was not completely film but a film-like residue with a thickness less than 1 μm, where self-absorption was not a serious problem. In the end, this sample preparation was demonstrated to improve TXRF quantification (intensity RSD: 2-4%).

Total reflection x-ray fluorescence - an approach to nanoanalysis

International Nuclear Information System (INIS)

Klockenkaemper, R.

2000-01-01

X-ray fluorescence analysis (XRFA) is a powerful tool used for industrial production, geological prospecting and for environmental control. However, the method suffers from a lack of sensitivity so that analyses are restricted to microanalytical investigations. That means: the sample amount needed for analysis is above some 10 micrograms, concentrations to be determined have to be on the μg/ml level, and thin layers to be characterized must be of micrometer thickness. In contrast to conventional XRFA, total-reflection X-ray fluorescence (TXRF) is extremely sensitive and even allows nano-analytical investigations. Three different ways can be taken: (i) use of minute sample amounts of only 10 nano-grams, (ii) determination of extreme traces below ng/ml and (iii) surface analysis and depth profiling of shallow layers with nano-meter thickness. In this lecture, the basic physical phenomena of total reflection and standing waves are outlined. The experimental equipment for TXRF is sketched out and commercially available instruments of different manufacturers are compared. Furthermore, examples are given for the three kinds of nano-analytical applications: ultra-micro, analysis, ultra trace analysis and mono- and thin-layer analysis. (author)

Quantitative determination of iron, copper, lead, chromium and nickel in electronic waste samples using total reflection x-ray fluorescence spectroscopy

International Nuclear Information System (INIS)

Elaseer, A. S.; Musbah, A. S; Ammar, M. M. G.; Salah, M. A.; Aisha, E. A.

2015-01-01

Total reflection x-ray fluorescence spectroscopy in conjunction with microwave assisted extraction technique was used for the analysis of twenty electronic waste samples. The analysis was limited to the printed circuit boards of electronic devices. Iron, copper, lead, chromium and nickel were quantitatively determined in the samples. The samples were carefully milled to fine powder and 50mg was digested by acid using microwave digestion procedure. The digested samples solution was spread together with gallium as internal standard on the reflection disk and analyzed. The results showed that the cassette recorder boards contain the highest concentration of iron, lead and nickel. The average concentrations of these metals were 78, 73 and 71g/Kg respectively. Computer boards contained the highest copper average concentration 39g/Kg. the highest chromium average concentration 3.6 g/Kg was in mobile phone boards. Measurements were made using PicoTAX portable x-ray device. the instrument was used for quantitative multi-element analysis. An air cooled x-ray tube (40KV, 1 mA) with Mo target and Be window was used as x-ray source. The optics of the device was a multilayer Ni/C, 17.5 keV, 80% reflectivity provides analysis of elements from Si to Zr (K series) and Rh to U (L series). A Si PIN-diode detector (7mm"2, 195eV) was used for the elements detection. In this study heavy metals average concentration in electronic circuit boards in the in the order of iron (35.25g/kg), copper (21.14g/Kg), lead (16.59g/Kg), nickel (16.01g/Kg) and chromium (1.07g/Kg).(author)

Total reflection x-ray fluorescence spectroscopy as a tool for evaluation of iron concentration in ferrofluids and yeast samples

Energy Technology Data Exchange (ETDEWEB)

Kulesh, N.A., E-mail: nikita.kulesh@urfu.ru [Ural Federal University, Mira 19, 620002 Ekaterinburg (Russian Federation); Novoselova, I.P. [Ural Federal University, Mira 19, 620002 Ekaterinburg (Russian Federation); Immanuel Kant Baltic Federal University, 236041 Kaliningrad (Russian Federation); Safronov, A.P. [Ural Federal University, Mira 19, 620002 Ekaterinburg (Russian Federation); Institute of Electrophysics UD RAS, Amundsen 106, 620016 Ekaterinburg (Russian Federation); Beketov, I.V.; Samatov, O.M. [Institute of Electrophysics UD RAS, Amundsen 106, 620016 Ekaterinburg (Russian Federation); Kurlyandskaya, G.V. [Ural Federal University, Mira 19, 620002 Ekaterinburg (Russian Federation); University of the Basque Country UPV-EHU, 48940 Leioa (Spain); Morozova, M. [Ural Federal University, Mira 19, 620002 Ekaterinburg (Russian Federation); Denisova, T.P. [Irkutsk State University, Karl Marks 1, 664003 Irkutsk (Russian Federation)

2016-10-01

In this study, total reflection x-ray fluorescent (TXRF) spectrometry was applied for the evaluation of iron concentration in ferrofluids and biological samples containing iron oxide magnetic nanoparticles obtained by the laser target evaporation technique. Suspensions of maghemite nanoparticles of different concentrations were used to estimate the limitation of the method for the evaluation of nanoparticle concentration in the range of 1–5000 ppm in absence of organic matrix. Samples of single-cell yeasts grown in the nutrient media containing maghemite nanoparticles were used to study the nanoparticle absorption mechanism. The obtained results were analyzed in terms of applicability of TXRF for quantitative analysis in a wide range of iron oxide nanoparticle concentrations for biological samples and ferrofluids with a simple established protocol of specimen preparation. - Highlights: • Ferrofluids and yeasts samples were analysed by TXRF spectroscopy. • Simple protocol for iron quantification by means of TXRF was proposed. • Results were combined with magnetic, structural, and morphological characterization. • Preliminary conclusion on nanoparticles uptake mechanism was made.

Total reflection x-ray fluorescence spectroscopy as a tool for evaluation of iron concentration in ferrofluids and yeast samples

International Nuclear Information System (INIS)

Kulesh, N.A.; Novoselova, I.P.; Safronov, A.P.; Beketov, I.V.; Samatov, O.M.; Kurlyandskaya, G.V.; Morozova, M.; Denisova, T.P.

2016-01-01

In this study, total reflection x-ray fluorescent (TXRF) spectrometry was applied for the evaluation of iron concentration in ferrofluids and biological samples containing iron oxide magnetic nanoparticles obtained by the laser target evaporation technique. Suspensions of maghemite nanoparticles of different concentrations were used to estimate the limitation of the method for the evaluation of nanoparticle concentration in the range of 1–5000 ppm in absence of organic matrix. Samples of single-cell yeasts grown in the nutrient media containing maghemite nanoparticles were used to study the nanoparticle absorption mechanism. The obtained results were analyzed in terms of applicability of TXRF for quantitative analysis in a wide range of iron oxide nanoparticle concentrations for biological samples and ferrofluids with a simple established protocol of specimen preparation. - Highlights: • Ferrofluids and yeasts samples were analysed by TXRF spectroscopy. • Simple protocol for iron quantification by means of TXRF was proposed. • Results were combined with magnetic, structural, and morphological characterization. • Preliminary conclusion on nanoparticles uptake mechanism was made.

Recent results of synchrotron radiation induced total reflection X-ray fluorescence analysis at HASYLAB, beamline L

Energy Technology Data Exchange (ETDEWEB)

Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria)]. E-mail: streli@ati.ac.at; Pepponi, G. [ITC-irst, Povo (Italy); Wobrauschek, P. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Jokubonis, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, A-1020 Vienna (Austria); Falkenberg, G. [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, D-22603 Hamburg (Germany); Zaray, G. [Institute of Inorganic and Applied Chemistry, 3 EOTVOS Univ, Budapest (Hungary); Broekaert, J. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Fittschen, U. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Peschel, B. [Institute of Anorganic and Applied Chemistry, University Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

2006-11-15

At the Hamburger Synchrotronstrahlungslabor (HASYLAB), Beamline L, a vacuum chamber for synchrotron radiation-induced total reflection X-ray fluorescence analysis, is now available which can easily be installed using the adjustment components for microanalysis present at this beamline. The detector is now in the final version of a Vortex silicon drift detector with 50-mm{sup 2} active area from Radiant Detector Technologies. With the Ni/C multilayer monochromator set to 17 keV extrapolated detection limits of 8 fg were obtained using the 50-mm{sup 2} silicon drift detector with 1000 s live time on a sample containing 100 pg of Ni. Various applications are presented, especially of samples which are available in very small amounts: As synchrotron radiation-induced total reflection X-ray fluorescence analysis is much more sensitive than tube-excited total reflection X-ray fluorescence analysis, the sampling time of aerosol samples can be diminished, resulting in a more precise time resolution of atmospheric events. Aerosols, directly sampled on Si reflectors in an impactor were investigated. A further application was the determination of contamination elements in a slurry of high-purity Al{sub 2}O{sub 3}. No digestion is required; the sample is pipetted and dried before analysis. A comparison with laboratory total reflection X-ray fluorescence analysis showed the higher sensitivity of synchrotron radiation-induced total reflection X-ray fluorescence analysis, more contamination elements could be detected. Using the Si-111 crystal monochromator also available at beamline L, XANES measurements to determine the chemical state were performed. This is only possible with lower sensitivity as the flux transmitted by the crystal monochromator is about a factor of 100 lower than that transmitted by the multilayer monochromator. Preliminary results of X-ray absorption near-edge structure measurements for As in xylem sap from cucumber plants fed with As(III) and As(V) are

Recent results of synchrotron radiation induced total reflection X-ray fluorescence analysis at HASYLAB, beamline L

International Nuclear Information System (INIS)

Streli, C.; Pepponi, G.; Wobrauschek, P.; Jokubonis, C.; Falkenberg, G.; Zaray, G.; Broekaert, J.; Fittschen, U.; Peschel, B.

2006-01-01

At the Hamburger Synchrotronstrahlungslabor (HASYLAB), Beamline L, a vacuum chamber for synchrotron radiation-induced total reflection X-ray fluorescence analysis, is now available which can easily be installed using the adjustment components for microanalysis present at this beamline. The detector is now in the final version of a Vortex silicon drift detector with 50-mm 2 active area from Radiant Detector Technologies. With the Ni/C multilayer monochromator set to 17 keV extrapolated detection limits of 8 fg were obtained using the 50-mm 2 silicon drift detector with 1000 s live time on a sample containing 100 pg of Ni. Various applications are presented, especially of samples which are available in very small amounts: As synchrotron radiation-induced total reflection X-ray fluorescence analysis is much more sensitive than tube-excited total reflection X-ray fluorescence analysis, the sampling time of aerosol samples can be diminished, resulting in a more precise time resolution of atmospheric events. Aerosols, directly sampled on Si reflectors in an impactor were investigated. A further application was the determination of contamination elements in a slurry of high-purity Al 2 O 3 . No digestion is required; the sample is pipetted and dried before analysis. A comparison with laboratory total reflection X-ray fluorescence analysis showed the higher sensitivity of synchrotron radiation-induced total reflection X-ray fluorescence analysis, more contamination elements could be detected. Using the Si-111 crystal monochromator also available at beamline L, XANES measurements to determine the chemical state were performed. This is only possible with lower sensitivity as the flux transmitted by the crystal monochromator is about a factor of 100 lower than that transmitted by the multilayer monochromator. Preliminary results of X-ray absorption near-edge structure measurements for As in xylem sap from cucumber plants fed with As(III) and As(V) are reported. Detection

Analysis of low Z elements in various environmental samples with total reflection X-ray fluorescence (TXRF) spectrometry

International Nuclear Information System (INIS)

Hoefler, H.; Streli, C.; Wobrauschek, P.; Ovari, M.; Zaray, Gy.

2006-01-01

Recently there is a growing interest in low Z elements such as carbon, oxygen up to sulphur and phosphorus in biological specimen. Total reflection X-ray fluorescence (TXRF) spectrometry is a suitable technique demanding only very small amounts of sample. On the other side, the detection of low Z elements is a critical point of this analytical technique. Besides other effects, self absorption may occur in the samples, because of the low energy of the fluorescence radiation. The calibration curves might be not linear any longer. To investigate this issue water samples and samples from human cerebrospinal fluid were used to examine absorption effects. The linearity of calibration curves in dependence of sample mass was investigated to verify the validity of the thin film approximation. The special requirements to the experimental setup for low Z energy dispersive fluorescence analysis were met by using the Atominstitute's TXRF vacuum chamber. This spectrometer is equipped with a Cr-anode X-ray tube, a multilayer monochromator and a SiLi detector with 30 mm 2 active area and with an ultrathin entrance window. Other object on this study are biofilms, living on all subaqueous surfaces, consisting of bacteria, algae and fungi embedded in their extracellular polymeric substances (EPS). Many trace elements from the water are bound in the biofilm. Thus, the biofilm is a useful indicator for polluting elements. For biomonitoring purposes not only the polluting elements but also the formation and growth rate of the biofilm are important. Biofilms were directly grown on TXRF reflectors. Their major elements and C-masses correlated to the cultivation time were investigated. These measured masses were related to the area seen by the detector, which was experimentally determined. Homogeneity of the biofilms was checked by measuring various sample positions on the reflectors

Analysis of low Z elements in various environmental samples with total reflection X-ray fluorescence (TXRF) spectrometry

Energy Technology Data Exchange (ETDEWEB)

Hoefler, H. [Atominstitut of the Austrian Universities, TU-Wien, A-1020 Vienna (Austria); Streli, C. [Atominstitut of the Austrian Universities, TU-Wien, A-1020 Vienna (Austria)]. E-mail: streli@ati.ac.at; Wobrauschek, P. [Atominstitut of the Austrian Universities, TU-Wien, A-1020 Vienna (Austria); Ovari, M. [Eoetvoes University, Institute of Chemistry, H-1117, Budapest, Pazmany P. stny 1/a. (Hungary); Zaray, Gy. [Eoetvoes University, Institute of Chemistry, H-1117, Budapest, Pazmany P. stny 1/a. (Hungary)

2006-11-15

Recently there is a growing interest in low Z elements such as carbon, oxygen up to sulphur and phosphorus in biological specimen. Total reflection X-ray fluorescence (TXRF) spectrometry is a suitable technique demanding only very small amounts of sample. On the other side, the detection of low Z elements is a critical point of this analytical technique. Besides other effects, self absorption may occur in the samples, because of the low energy of the fluorescence radiation. The calibration curves might be not linear any longer. To investigate this issue water samples and samples from human cerebrospinal fluid were used to examine absorption effects. The linearity of calibration curves in dependence of sample mass was investigated to verify the validity of the thin film approximation. The special requirements to the experimental setup for low Z energy dispersive fluorescence analysis were met by using the Atominstitute's TXRF vacuum chamber. This spectrometer is equipped with a Cr-anode X-ray tube, a multilayer monochromator and a SiLi detector with 30 mm{sup 2} active area and with an ultrathin entrance window. Other object on this study are biofilms, living on all subaqueous surfaces, consisting of bacteria, algae and fungi embedded in their extracellular polymeric substances (EPS). Many trace elements from the water are bound in the biofilm. Thus, the biofilm is a useful indicator for polluting elements. For biomonitoring purposes not only the polluting elements but also the formation and growth rate of the biofilm are important. Biofilms were directly grown on TXRF reflectors. Their major elements and C-masses correlated to the cultivation time were investigated. These measured masses were related to the area seen by the detector, which was experimentally determined. Homogeneity of the biofilms was checked by measuring various sample positions on the reflectors.

Frustrated Total Internal Reflection: A Simple Application and Demonstration.

Science.gov (United States)

Zanella, F. P.; Magalhaes, D. V.; Oliveira, M. M.; Bianchi, R. F.; Misoguti, L.; Mendonca, C. R.

2003-01-01

Describes the total internal reflection process that occurs when the internal angle of incidence is equal to or greater than the critical angle. Presents a demonstration of the effect of frustrated total internal reflection (FTIR). (YDS)

Total reflection X-ray photoelectron spectroscopy: A review

International Nuclear Information System (INIS)

Kawai, Jun

2010-01-01

Total reflection X-ray photoelectron spectroscopy (TRXPS) is reviewed and all the published papers on TRXPS until the end of 2009 are included. Special emphasis is on the historical development. Applications are also described for each report. The background reduction is the most important effect of total reflection, but interference effect, relation to inelastic mean free path, change of probing depth are also discussed.

Efficient isotope ratio analysis of uranium particles in swipe samples by total-reflection x-ray fluorescence spectrometry and secondary ion mass spectrometry

International Nuclear Information System (INIS)

Esaka, Fumitaka; Watanabe, Kazuo; Fukuyama, Hiroyasu; Onodera, Takashi; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu

2004-01-01

A new particle recovery method and a sensitive screening method were developed for subsequent isotope ratio analysis of uranium particles in safeguards swipe samples. The particles in the swipe sample were recovered onto a carrier by means of vacuum suction-impact collection method. When grease coating was applied to the carrier, the recovery efficiency was improved to 48±9%, which is superior to that of conventionally-used ultrasoneration method. Prior to isotope ratio analysis with secondary ion mass spectrometry (SIMS), total reflection X-ray fluorescence spectrometry (TXRF) was applied to screen the sample for the presence of uranium particles. By the use of Si carriers in TXRF analysis, the detection limit of 22 pg was achieved for uranium. By combining these methods with SIMS, the isotope ratios of 235 U/ 238 U for individual uranium particles were efficiently determined. (author)

Total-reflection X-ray fluorescence analysis of Austrian wine

International Nuclear Information System (INIS)

Gruber, X.; Kregsamer, P.; Wobrauschek, P.; Streli, C.

2006-01-01

The concentration of major, minor and trace elements in Austrian wine was determined by total-reflection X-ray fluorescence using gallium as internal standard. A multi-elemental analysis was possible by pipetting 6 μl of wine directly on the reflector and drying. Total-reflection X-ray fluorescence analysis was performed with Atomika EXTRA II A (Cameca) X-rays from a Mo tube with a high-energy cut-off at 20 keV in total-reflection geometry. The results showed that it was possible to identify only by the elemental analysis as fingerprint the vineyards and year of vintage among 11 different wines

Total-reflection X-ray fluorescence analysis of Austrian wine

Energy Technology Data Exchange (ETDEWEB)

Gruber, X. [Atominstitut der Osterreichischen Universitaeten, 1020 Vienna (Austria); Kregsamer, P. [Atominstitut der Osterreichischen Universitaeten, 1020 Vienna (Austria); Wobrauschek, P. [Atominstitut der Osterreichischen Universitaeten, 1020 Vienna (Austria); Streli, C. [Atominstitut der Osterreichischen Universitaeten, 1020 Vienna (Austria)]. E-mail: streli@ati.ac.at

2006-11-15

The concentration of major, minor and trace elements in Austrian wine was determined by total-reflection X-ray fluorescence using gallium as internal standard. A multi-elemental analysis was possible by pipetting 6 {mu}l of wine directly on the reflector and drying. Total-reflection X-ray fluorescence analysis was performed with Atomika EXTRA II A (Cameca) X-rays from a Mo tube with a high-energy cut-off at 20 keV in total-reflection geometry. The results showed that it was possible to identify only by the elemental analysis as fingerprint the vineyards and year of vintage among 11 different wines.

Total and available metal contents in sediments by synchrotron radiation total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Moreira, Silvana; Sobrinho, Gilmar A.; Jesus, Edgar F.O. de; Lopes, Ricardo T.

2002-01-01

In this work the total and available contents of Al, Si, Cl, K, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Ba, Ce and Pb in sediments from river Atibaia were determined by Synchrotron Radiation Total Reflection X-Ray Fluorescence technique. The detection limits for K series varies from 200 ng.mL -1 for Al to 2 ng.mL -1 for Zn while for L series the value varies from 20 ng.mL -1 for Ba to 10 ng.mL -1 for Pb. The samples were submitted to two different processes, in order to obtain the total and biological available metal contents. The information about metal content is a important parameter for a correct evaluation about the hydrologic cycle in Piracicaba basin. All the measure were carried out at the National Synchrotron Light Laboratory, Campinas, SP, Brazil, using a white beam for excitation. (author)

Total Internal Reflection Fluorescence Microscopy Imaging-Guided Confocal Single-Molecule Fluorescence Spectroscopy

OpenAIRE

Zheng, Desheng; Kaldaras, Leonora; Lu, H. Peter

2013-01-01

We have developed an integrated spectroscopy system combining total internal reflection fluorescence microscopy imaging with confocal single-molecule fluorescence spectroscopy for two-dimensional interfaces. This spectroscopy approach is capable of both multiple molecules simultaneously sampling and in situ confocal fluorescence dynamics analyses of individual molecules of interest. We have demonstrated the calibration with fluorescent microspheres, and carried out single-molecule spectroscop...

Total Reflection X-ray Fluorescence attachment module modified for analysis in vacuum

International Nuclear Information System (INIS)

Wobrauschek, P.; Streli, C.; Kregsamer, P.; Meirer, F.; Jokubonis, C.; Markowicz, A.; Wegrzynek, D.; Chinea-Cano, E.

2008-01-01

Based on the design of the low cost Total Reflection X-Ray Fluorescence attachment module available since 1986 from Atominstitut (WOBRAUSCHEK-module) which can be attached to existing X-ray equipment, a new version was developed which allows the analysis of samples in vacuum. This design was in particular possible as the Peltier cooled light weight Silicon Drift Detector is following all adjustment procedures for total reflection as angle rotation and linear motion. The detector is mounted through a vacuum feed and O-ring tightening to the small vacuum chamber. The standard 30 mm round quartz, Si-wafer or Plexiglas reflectors are used to carry the samples. The reflectors are placed on the reference plane with the dried sample down looking facing in about 0.5 mm distance the up looking detector window. The reflectors are resting on 3 steel balls defining precisely the reference plane for the adjustment procedure. As the rotation axis of the module is in the plane of the reflector surface, angle dependent experiments can be made to distinguish between film and particulate type contamination of samples. Operating with a Mo anode at 50 kV and 40 mA with a closely attached multilayer monochromator and using a 10 mm 2 KETEK silicon drift detector with 8 μm Be window, a sensitivity of 70 cps/ng for Rb was measured and detection limits of 2 pg were obtained

Discrimination of the hard keratins animal horn and chelonian shell using attenuated total reflection-infrared spectroscopy.

Science.gov (United States)

Biscardi, Brianna; Welsh, Wendy; Kennedy, Anthony

2012-05-01

The ability to discriminate between objects manufactured from animal horn and chelonian (turtle, tortoise, or terrapin) shell is important from a cultural and archeological perspective such that it may allow conservators to determine the appropriate treatment and long-term care solution. It would also aid curators in identifying and cataloging items manufactured from these materials. Discrimination and classification is also a valuable tool for those involved in tracking the illegal trade in restricted materials of this nature. Attenuated total reflection infrared (ATR-IR) spectroscopy, using a single reflection diamond internal reflection element (IRE), coupled with discrimination analysis was used to analyze a total of thirty-nine samples (29 calibration samples, 10 validation samples). A discrimination analysis model was constructed using Mahalanobis distances to classify spectra into one of two classes. The model was then subsequently used to successfully classify all validation samples and correctly identify them as animal horn or chelonian shell based on second-derivative spectra of the amide I and II regions. This technique requires minimal to no sample preparation and may be used to nondestructively identify very small samples successfully without performing detailed secondary structural curve-fitting routines. This model should be a valuable resource to museums, conservators, and wildlife management programs for rapidly and reliably discriminating between animal horn and chelonian shell.

Nonimaging light concentration using total internal reflection films.

Science.gov (United States)

Ouellette, G; Waltham, C E; Drees, R M; Poon, A; Schubank, R; Whitehead, L A

1992-05-01

We present a method of fabricating nonimaging light concentrators from total internal reflection film. A prototype has been made and tested and found to operate in agreement with predictions of ray-tracing codes. The performance of the prototype is comparable with that of concentrators made from specular reflecting materials.

Determination of sulphur with total reflection x-ray spectrometry

International Nuclear Information System (INIS)

Steinmeyer, S.; Kolbesen, B.O.

2000-01-01

The potential and limitations of total reflection x-ray spectrometry (TXRF) were tested for the quantitative determination of the light element sulphur in inorganic and biological samples. As representatives of inorganic samples alkali, transition metal, magnesium and aluminum sulphates were investigated. As biological samples the sulphur containing amino acid methionine and the pharmaceutical drug insulin were chosen. All measurements were performed on a TXRF-spectrometer EXTRA IIA (Atomika Instruments, Oberschleissheim/Germany) using tungsten L-radiation as the excitation tube. Various concentrations of all samples ranging from 20 mg/l to 0.5 mg/l were determined. In addition the surface topography and thickness of the dry residue of these samples were investigated with SEM and a thickness profilometer (Alpha-Step). The result show that the reliable determination of sulphur in sulphates depends on the cation involved. Alkali sulphates like Na 2 SO 4 , or K 2 SO 4 form bulky residues resulting in significant deviations of the recovery rate of sulphur. In this case the use of smoothing detergents like 1 % HF, 1 % malic acid and 2 % hydrazinhydrat was found to be necessary for accurate determination. The results for the biological samples agree well with the expected values. The investigations lead to the conclusion that TXRF combined with a proper samples preparation is well suited for the determination of sulphur in different samples with various concentrations and matrices. (author)

Mix ratio measurements of pozzolanic blends by Fourier transform infrared-attenuated total reflectance method

International Nuclear Information System (INIS)

Rebagay, T.V.; Dodd, D.A.

1992-07-01

The disposal of low-level radioactive liquid wastes at the Hanford Site near Richland, Washington, involves mixing the wastes with pozzolanic grout-forming solid blends. Checking the quality of each blend component and its mix ratio will ensure processibility of the blend and the long-term performance of the resulting waste grout. In earlier work at Hanford laboratories, Fourier transform infrared-transmission method (FTIR-TR) using KBr pellet was applied successfully in the analysis of blends consisting of cement, fly ash, and clays. This method involves time-consuming sample preparation resulting in slow turnaround for repetitive sampling. Because reflection methods do not require elaborate sample preparation, they have the potential to reduce turnaround analysis time. Neat samples may be examined making these methods attractive for quality control. This study investigates the capability of Fourier transform infrared-attenuated total reflectance method (FTIR-ATR) to analyze pozzolanic blends

All-optical microscope autofocus based on an electrically tunable lens and a totally internally reflected IR laser.

Science.gov (United States)

Bathe-Peters, M; Annibale, P; Lohse, M J

2018-02-05

Microscopic imaging at high spatial-temporal resolution over long time scales (minutes to hours) requires rapid and precise stabilization of the microscope focus. Conventional and commercial autofocus systems are largely based on piezoelectric stages or mechanical objective actuators. Objective to sample distance is either measured by image analysis approaches or by hardware modules measuring the intensity of reflected infrared light. We propose here a truly all-optical microscope autofocus taking advantage of an electrically tunable lens and a totally internally reflected infrared probe beam. We implement a feedback-loop based on the lateral position of a totally internally reflected infrared laser on a quadrant photodetector, as an indicator of the relative defocus. We show here how to treat the combined contributions due to mechanical defocus and deformation of the tunable lens. As a result, the sample can be kept in focus without any mechanical movement, at rates up to hundreds of Hertz. The device requires only reflective optics and can be implemented at a fraction of the cost required for a comparable piezo-based actuator.

Multielement analysis of environmental samples by total-reflection X-ray fluorescence sprectrometry, neutron activation analysis and inductively coupled plasma optical emission spectroscopy

International Nuclear Information System (INIS)

Michaelis, W.

1986-01-01

In environmental research and protection trace elements have to be determined over a wide range of atomic number, down to very low concentrations, and in quite different matrices. This challenge requires the availability of complementary analytical methods characterized by a high detection power and few sources of systematic errors. Besides, the capacity of multielement detection is often desired since it facilitates the talking of many problems in which numerous trace elements are of direct concern. Total-reflection X-ray fluorescence, neutron activation analysis and inductively coupled plasma optical emission spectroscopy, in principle fulfill these requirements quite well. However, each method has its domain, and the application to certain sample species may be less promising. Under this aspect, the paper summarizes some recent developments and investigations, including intercomparisons as far as possible. Various matrices are considered : rainwater and airborne particulates, soil samples, river sediments and suspended particulate matter, river water filtrates, ozean water, and organic matrices. Capabilities and limitations are discussed. Sample preparation techniques are described if they are new or essential for achieving the results given. (orig.) [de

Preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for samples from Upper and Lower Cretaceous strata, Maverick Basin, south Texas

Science.gov (United States)

Hackley, Paul C.; Dennen, Kristin O.; Gesserman, Rachel M.; Ridgley, Jennie L.

2009-01-01

The Lower Cretaceous Pearsall Formation, a regionally occurring limestone and shale interval of 500-600-ft maximum thickness (Rose, 1986), is being evaluated as part of an ongoing U.S. Geological Survey (USGS) assessment of undiscovered hydrocarbon resources in onshore Lower Cretaceous strata of the northern Gulf of Mexico. The purpose of this report is to release preliminary vitrinite and bitumen reflectance, total organic carbon, and pyrolysis data for Pearsall Formation, Glen Rose Formation, Hosston Formation, Austin Group, and Eagle Ford Group samples from the Maverick Basin in south Texas in order to aid in the characterization of these strata in this area. The preliminary nature of this report and the data contained herein reflect that the assessment and characterization of these samples is a work currently in progress. Pearsall Formation subdivisions are, in ascending stratigraphic order, the Pine Island Shale, James Limestone, and Bexar Shale Members (Loucks, 2002). The Lower Cretaceous Glen Rose Formation is also part of the USGS Lower Cretaceous assessment and produces oil in the Maverick Basin (Loucks and Kerans, 2003). The Hosston Formation was assessed by the USGS for undiscovered oil and gas resources in 2006 (Dyman and Condon, 2006), but not in south Texas. The Upper Cretaceous Austin Group is being assessed as part of the USGS assessment of undiscovered hydrocarbon resources in the Upper Cretaceous strata of the northern Gulf of Mexico and, along with the Upper Cretaceous Eagle Ford Group, is considered to be an important source rock in the Smackover-Austin-Eagleford Total Petroleum System (Condon and Dyman, 2006). Both the Austin Group and the Eagle Ford Group are present in the Maverick Basin in south Texas (Rose, 1986).

Chlorine determination in (U, Pu)C fuel by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Misra, Nand Lal; Dhara, Sangita; Mudher, Khush Dev Singh; Aggarwal, Suresh K.; Thakur, Uday Kumar; Shah, Dipti; Sawant, R.M.; Ramakumar, K.L.

2007-01-01

A Total Reflection X-ray Fluorescence (TXRF) method for the determination of chlorine in (U,Pu)C has been developed. The method involves calibration of the instrument with standard solutions and validation of TXRF determination of chlorine using synthetic standard solutions. Cl K α line excited with W L α source was used for TXRF determinations of chlorine. Chlorine present in trace amounts in (U,Pu)C samples was first separated by pyro hydrolysis. The evolved chlorine, in form of HCl, was collected in 5 mM NaOH solution. This solution was analyzed for chlorine by Total Reflection X-ray Fluorescence Spectrometry using cobalt as an internal standard. The TXRF detection limit of chlorine was found to be 3.6 pg with sample size of 30 μL. In order to assess the applicability of TXRF method for chlorine determinations in other nuclear materials, one U 3 O 8 trace element standard was also analyzed for chlorine in similar way. The precision of the method was found to be 25% (1 σ) at ng level in most of the cases. (author)

Application of the Total Reflection X-ray Fluorescence technique to trace elements determination in tobacco

International Nuclear Information System (INIS)

Martinez, T.; Lartigue, J.; Zarazua, G.; Avila-Perez, P.; Navarrete, M.; Tejeda, S.

2008-01-01

Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples

Application of the Total Reflection X-ray Fluorescence technique to trace elements determination in tobacco

Science.gov (United States)

Martinez, T.; Lartigue, J.; Zarazua, G.; Avila-Perez, P.; Navarrete, M.; Tejeda, S.

2008-12-01

Many studies have identified an important number of toxic elements along with organic carcinogen molecules and radioactive isotopes in tobacco. In this work we have analyzed by Total Reflection X-Ray Fluorescence 9 brands of cigarettes being manufactured and distributed in the Mexican market. Two National Institute of Standards and Technology standards and a blank were equally treated at the same time. Results show the presence of some toxic elements such as Pb and Ni. These results are compared with available data for some foreign brands, while their implications for health are discussed. It can be confirmed that the Total Reflection X-Ray Fluorescence method provides precise (reproducible) and accuracy (trueness) data for 15 elements concentration in tobacco samples.

The capabilities of total reflection X-ray fluorescence in the polymeric analytical field

International Nuclear Information System (INIS)

Vazquez, Cristina

2004-01-01

This paper presents the capabilities of total reflection X-ray fluorescence (TXRF) as analytical technique specially focused in high-viscosity polymer dispersions. Appropriate sample preparation procedures are described taking into account the time stability of these dispersions. Special remarks considering different ways for drying samples in order to obtain the most uniform deposited film are investigated focusing on the behavior of aqueous and viscous systems. Due to the difficulty found for obtaining a homogeneous mixture between sample and internal standard in such systems, the use of Compton incoherent scattering is discussed as an alternative procedure for trace quantification in high viscous systems without any mixing processes

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-11-15

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

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

Science.gov (United States)

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

2006-11-01

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

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

International Nuclear Information System (INIS)

Zarazua, G.; Avila-Perez, P.; Tejeda, S.; Barcelo-Quintal, I.; Martinez, T.

2006-01-01

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

Optimizing total reflection X-ray fluorescence for direct trace element quantification in proteins I: Influence of sample homogeneity and reflector type

Science.gov (United States)

Wellenreuther, G.; Fittschen, U. E. A.; Achard, M. E. S.; Faust, A.; Kreplin, X.; Meyer-Klaucke, W.

2008-12-01

Total reflection X-ray fluorescence (TXRF) is a very promising method for the direct, quick and reliable multi-elemental quantification of trace elements in protein samples. With the introduction of an internal standard consisting of two reference elements, scandium and gallium, a wide range of proteins can be analyzed, regardless of their salt content, buffer composition, additives and amino acid composition. This strategy also enables quantification of matrix effects. Two potential issues associated with drying have been considered in this study: (1) Formation of heterogeneous residues of varying thickness and/or density; and (2) separation of the internal standard and protein during drying (which has to be prevented to allow accurate quantification). These issues were investigated by microbeam X-ray fluorescence (μXRF) with special emphasis on (I) the influence of sample support and (II) the protein / buffer system used. In the first part, a model protein was studied on well established sample supports used in TXRF, PIXE and XRF (Mylar, siliconized quartz, Plexiglas and silicon). In the second part we imaged proteins of different molecular weight, oligomerization state, bound metals and solubility. A partial separation of protein and internal standard was only observed with untreated silicon, suggesting it may not be an adequate support material. Siliconized quartz proved to be the least prone to heterogeneous drying of the sample and yielded the most reliable results.

Optimizing total reflection X-ray fluorescence for direct trace element quantification in proteins I: Influence of sample homogeneity and reflector type

Energy Technology Data Exchange (ETDEWEB)

Wellenreuther, G. [European Molecular Biology Laboratory, Notkestr. 85, 22603 Hamburg (Germany); Fittschen, U.E.A. [Department of Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Achard, M.E.S.; Faust, A.; Kreplin, X. [European Molecular Biology Laboratory, Notkestr. 85, 22603 Hamburg (Germany); Meyer-Klaucke, W. [European Molecular Biology Laboratory, Notkestr. 85, 22603 Hamburg (Germany)], E-mail: Wolfram@embl-hamburg.de

2008-12-15

Total reflection X-ray fluorescence (TXRF) is a very promising method for the direct, quick and reliable multi-elemental quantification of trace elements in protein samples. With the introduction of an internal standard consisting of two reference elements, scandium and gallium, a wide range of proteins can be analyzed, regardless of their salt content, buffer composition, additives and amino acid composition. This strategy also enables quantification of matrix effects. Two potential issues associated with drying have been considered in this study: (1) Formation of heterogeneous residues of varying thickness and/or density; and (2) separation of the internal standard and protein during drying (which has to be prevented to allow accurate quantification). These issues were investigated by microbeam X-ray fluorescence ({mu}XRF) with special emphasis on (I) the influence of sample support and (II) the protein / buffer system used. In the first part, a model protein was studied on well established sample supports used in TXRF, PIXE and XRF (Mylar, siliconized quartz, Plexiglas and silicon). In the second part we imaged proteins of different molecular weight, oligomerization state, bound metals and solubility. A partial separation of protein and internal standard was only observed with untreated silicon, suggesting it may not be an adequate support material. Siliconized quartz proved to be the least prone to heterogeneous drying of the sample and yielded the most reliable results.

Diffuse Reflectance Spectroscopy for Total Carbon Analysis of Hawaiian Soils

Science.gov (United States)

McDowell, M. L.; Bruland, G. L.; Deenik, J. L.; Grunwald, S.; Uchida, R.

2010-12-01

Accurate assessment of total carbon (Ct) content is important for fertility and nutrient management of soils, as well as for carbon sequestration studies. The non-destructive analysis of soils by diffuse reflectance spectroscopy (DRS) is a potential supplement or alternative to the traditional time-consuming and costly combustion method of Ct analysis, especially in spatial or temporal studies where sample numbers are large. We investigate the use of the visible to near-infrared (VNIR) and mid-infrared (MIR) spectra of soils coupled with chemometric analysis to determine their Ct content. Our specific focus is on Hawaiian soils of agricultural importance. Though this technique has been introduced to the soil community, it has yet to be fully tested and used in practical applications for all soil types, and this is especially true for Hawaii. In short, DRS characterizes and differentiates materials based on the variation of the light reflected by a material at certain wavelengths. This spectrum is dependent on the material’s composition, structure, and physical state. Multivariate chemometric analysis unravels the information in a set of spectra that can help predict a property such as Ct. This study benefits from the remarkably diverse soils of Hawaii. Our sample set includes 216 soil samples from 145 pedons from the main Hawaiian Islands archived at the National Soil Survey Center in Lincoln, NE, along with more than 50 newly-collected samples from Kauai, Oahu, Molokai, and Maui. In total, over 90 series from 10 of the 12 soil orders are represented. The Ct values of these samples range from < 1% - 55%. We anticipate that the diverse nature of our sample set will ensure a model with applicability to a wide variety of soils, both in Hawaii and globally. We have measured the VNIR and MIR spectra of these samples and obtained their Ct values by dry combustion. Our initial analyses are conducted using only samples obtained from the Lincoln archive. In this

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

International Nuclear Information System (INIS)

Toelg, G.; Klockenkaemper, R.

1993-01-01

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

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

International Nuclear Information System (INIS)

Amberger, Martin A.; Hoeltig, Michael; Broekaert, Jose A.C.

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2010-02-15

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

Studies and developments for the analysis of products of nuclear reprocessing plants with the help of the X-ray fluorescence analysis on totally reflecting sample holders (TXRF)

International Nuclear Information System (INIS)

Diercks, H.; Eggers, I.; Gibau, F.; Haarich, M.; Hastenteufel, S.; Haurand, M.; Knoechel, A.; Salow, H.

1990-01-01

Studies with inactive and active simulates of products of nuclear reprocessing plants show the suitability of the X-Ray Fluorescence Analysis on Totally Reflecting Sample Holders (TXRF), to detect the available elements simultaneously by direct measurements of specially prepared thin samples. High dilution enables in the most cases, to avoid working in hot cells and to carry out the analysis in glove boxes. The analysis of uranium products and great amounts of matrix elements containing solutions like LAW and MAW demands the separation of the matrix elements before TXRF measurement. Procedures for this task have been developed. The potential of the new analytical procedure was demonstrated by the analysis of two samples of highly diluted high active wastes. (orig.) With 65 refs., 20 tabs., 81 figs [de

On Optimal, Minimal BRDF Sampling for Reflectance Acquisition

DEFF Research Database (Denmark)

Nielsen, Jannik Boll; Jensen, Henrik Wann; Ramamoorthi, Ravi

2015-01-01

The bidirectional reflectance distribution function (BRDF) is critical for rendering, and accurate material representation requires data-driven reflectance models. However, isotropic BRDFs are 3D functions, and measuring the reflectance of a flat sample can require a million incident and outgoing...... direction pairs, making the use of measured BRDFs impractical. In this paper, we address the problem of reconstructing a measured BRDF from a limited number of samples. We present a novel mapping of the BRDF space, allowing for extraction of descriptive principal components from measured databases......, such as the MERL BRDF database. We optimize for the best sampling directions, and explicitly provide the optimal set of incident and outgoing directions in the Rusinkiewicz parameterization for n = {1, 2, 5, 10, 20} samples. Based on the principal components, we describe a method for accurately reconstructing BRDF...

The capabilities of total reflection X-ray fluorescence in the polymeric analytical field*1

Science.gov (United States)

Vázquez, Cristina

2004-08-01

This paper presents the capabilities of total reflection X-ray fluorescence (TXRF) as analytical technique specially focused in high-viscosity polymer dispersions. Appropriate sample preparation procedures are described taking into account the time stability of these dispersions. Special remarks considering different ways for drying samples in order to obtain the most uniform deposited film are investigated focusing on the behavior of aqueous and viscous systems. Due to the difficulty found for obtaining a homogeneous mixture between sample and internal standard in such systems, the use of Compton incoherent scattering is discussed as an alternative procedure for trace quantification in high viscous systems without any mixing processes.

Critical coupling of surface plasmons in graphene attenuated total reflection geometry

Energy Technology Data Exchange (ETDEWEB)

Cuevas, Mauro, E-mail: cuevas@df.uba.ar [Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) and Facultad de Ingeniería y Tecnología Informática, Universidad de Belgrano, Villanueva 1324, C1426BMJ, Buenos Aires (Argentina); Grupo de Electromagnetismo Aplicado, Departamento de Física, FCEN, Universidad de Buenos Aires and IFIBA, Ciudad Universitaria, Pabellón I, C1428EHA, Buenos Aires (Argentina)

2016-12-09

We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.

Critical coupling of surface plasmons in graphene attenuated total reflection geometry

International Nuclear Information System (INIS)

Cuevas, Mauro

2016-01-01

We study the optical response of an attenuated total reflection (ATR) structure in Otto configuration with graphene sheet, paying especial attention to the occurrence of total absorption. Our results show that due to excitation of surface plasmons on the graphene sheet, two different conditions of total absorption may occur. At these conditions, the energy loss of the surface plasmon by radiation is equal to its energy loss by absorption into the graphene sheet. We give necessary conditions on ATR parameters for the existence of total absorption. - Highlights: • Attenuated total reflection (ATR) structure with graphene sheet. • Surface plasmons and power matched condition. • Necessary conditions on ATR parameters for the existence of total absorption.

Refractive Index Imaging of Cells with Variable-Angle Near-Total Internal Reflection (TIR) Microscopy.

Science.gov (United States)

Bohannon, Kevin P; Holz, Ronald W; Axelrod, Daniel

2017-10-01

The refractive index in the interior of single cells affects the evanescent field depth in quantitative studies using total internal reflection (TIR) fluorescence, but often that index is not well known. We here present method to measure and spatially map the absolute index of refraction in a microscopic sample, by imaging a collimated light beam reflected from the substrate/buffer/cell interference at variable angles of incidence. Above the TIR critical angle (which is a strong function of refractive index), the reflection is 100%, but in the immediate sub-critical angle zone, the reflection intensity is a very strong ascending function of incidence angle. By analyzing the angular position of that edge at each location in the field of view, the local refractive index can be estimated. In addition, by analyzing the steepness of the edge, the distance-to-substrate can be determined. We apply the technique to liquid calibration samples, silica beads, cultured Chinese hamster ovary cells, and primary culture chromaffin cells. The optical technique suffers from decremented lateral resolution, scattering, and interference artifacts. However, it still provides reasonable results for both refractive index (~1.38) and for distance-to-substrate (~150 nm) for the cells, as well as a lateral resolution to about 1 µm.

Integrating sphere based reflectance measurements for small-area semiconductor samples

Science.gov (United States)

Saylan, S.; Howells, C. T.; Dahlem, M. S.

2018-05-01

This article describes a method that enables reflectance spectroscopy of small semiconductor samples using an integrating sphere, without the use of additional optical elements. We employed an inexpensive sample holder to measure the reflectance of different samples through 2-, 3-, and 4.5-mm-diameter apertures and applied a mathematical formulation to remove the bias from the measured spectra caused by illumination of the holder. Using the proposed method, the reflectance of samples fabricated using expensive or rare materials and/or low-throughput processes can be measured. It can also be incorporated to infer the internal quantum efficiency of small-area, research-level solar cells. Moreover, small samples that reflect light at large angles and develop scattering may also be measured reliably, by virtue of an integrating sphere insensitive to directionalities.

1. Latin American Workshop on Total Reflection X-Ray Fluorescence (TXRF) and its Applications: TARABANA 99. Programme and Abstracts

International Nuclear Information System (INIS)

Vegas C, Fredy; Greaves N, Eduardo; Marco P, Lue-Meru

1999-01-01

It concerns about the advances in Total Reflection X-Ray Fluorescence (TXRF) instrumentation; structure, characteristic and potential of TXRF equipment used for chemical multielemental survey; TXRF: an approach to nano analysis; microanalytical investigation of environmental samples by TXRF spectrometry; TXRF of low Z elements; assessment of serum selenium levels in 2 month old sucking calves using TXRF: A powerful method to investigate the elemental composition of spheroids; environmental applications of TXRF; use of modifiers for the elimination in situ of chlorides in the analysis of TXRF; experimental methodology and analysis spectra for the determination of mercury by means of TXRF using amalgamation with gold; multielemental analysis of human amniotic fluid by use of Total Reflection X-Ray Fluorescence and rutherford forward scattering; determination of metal in samples of handmade penca; determination of oligo elements, platinum and relationship Zn/Cu in samples of blood serum and urine in oncological pediatric patient [es

Colouration of medieval glass bracelets studied by total reflection x-ray fluorescence analysis

International Nuclear Information System (INIS)

Detcheva, Albena; Velinova, Ralitsa; Ivanova, Elisaveta; Jordanov, Juri; Karadjov, Metody

2014-01-01

The contents of 3d-transition metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu and Zn) in fragments of medieval glass bracelets, found in the necropolis of Stambolovo and the castle of Mezek, Bulgaria, were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The samples were analysed as slurries in Triton X 114. The experimental parameters: grain size of the glass sample, concentrations of glass sample, Triton X114 and internal standard in the slurry, volume of the slurry aliquot taken for analysis, as well as the excitation time, were optimised. For method validation the certified reference material BAM-S005 Type A soda-lime glass was used. It was proven that the elements Co, Mn and Fe are responsible for colour generation in the investigated glass samples. The precision of the determinations is characterised by an RSD in the range 3–11%

Use of total internal reflection Raman (TIR) and attenuated total reflection infrared (ATR-IR) spectroscopy to analyze component separation in thin offset ink films after setting on coated paper surfaces.

Science.gov (United States)

Kivioja, Antti; Hartus, Timo; Vuorinen, Tapani; Gane, Patrick; Jääskeläinen, Anna-Stiina

2013-06-01

The interactive behavior of ink constituents with porous substrates during and after the offset print process has an important effect on the quality of printed products. To help elucidate the distribution of ink components between the retained ink layer and the substrate, a variety of spectroscopic and microscopic analysis techniques have been developed. This paper describes for the first time the use of total internal reflection (TIR) Raman spectroscopy to analyze the penetration behavior of separated offset ink components (linseed oil, solid color pigment) in coated papers providing chemically intrinsic information rapidly, nondestructively, and with minimal sample preparation. In addition, the already widely applied technique of attenuated total reflection infrared spectroscopy (ATR-IR) was evaluated in parallel and compared. The results of the ATR-IR Raman clearly revealed an improvement in uppermost depth resolution compared with values previously published from other nondestructive techniques, and the method is shown to be capable of providing new knowledge of the setting of thin (0.25-2 μm) offset ink films, allowing the spreading and the penetration behavior on physically different paper coating surfaces to be studied.

Impurities determination in uranium eluates by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Vazquez, Cristina; Bellavigna, Horacio J.; Eppis, Maria R.; Ramella, Jose L.

1999-01-01

The chemical control of impurities in nuclear materials is indispensable in order to assure an efficient operation of the reactors. The maximum concentration admitted depends of the elements and in most cases are in the parts per billion range. Conventional analytical methods require a pre-concentration treatment of the sample and a previous separation of the matrix (uranium). This paper investigates the use of the total reflection X-ray fluorescence as an alternative methodology for the determination of impurities in nuclear materials, namely K, Ca, Ti, Cr, Mn, Fe, Ni, Cu and As. The detection limits obtained were in the range of 0.1 to 20 ng/ml for a 1000 seconds counting time. (author)

Development of a total reflection X-ray fluorescence spectrometer for ...

Indian Academy of Sciences (India)

Unknown

design and use of a peltier cooled solid state detector for energy dispersive detection. Alignment and ... X-ray beam at a glancing angle less than the critical angle at which total ... materials is < 1 so that external total reflection takes place at an ...

Fundamental quantification procedure for total reflection X-ray fluorescence spectra analysis and elements determination

International Nuclear Information System (INIS)

Wegrzynek, D.; Holynska, B.

1997-01-01

A method for the determination of the concentrations of elements in particulate-like samples measured in total reflection geometry is proposed. In the proposed method the fundamental parameters are utilized for calculating the sensitivities of elements and an internal standard is used to account for the unknown mass per unit area of a sample and geometrical constant of the spectrometer. The modification of the primary excitation spectrum on its way to a sample has been taken into consideration. The concentrations of the elements to be determined are calculated simultaneously with the spectra deconvolution procedure. In the process of quantitative analysis the intensities of all X-ray peaks corresponding to K and L-series lines present in the analyzed spectrum are taken into account. (Author)

Pigment particles analysis with a total reflection X-ray fluorescence spectrometer: study of influence of instrumental parameters

Energy Technology Data Exchange (ETDEWEB)

Coccato, Alessia; Vandenabeele, Peter [Ghent University, Department of Archaeology, Ghent (Belgium); Vekemans, Bart; Vincze, Laszlo; Moens, Luc [Ghent University, Department of Analytical Chemistry, Ghent (Belgium)

2016-12-15

Total reflection X-ray fluorescence (TXRF) analysis is an excellent tool to determine major, minor and trace elements in minuscule amounts of samples, making this technique very suitable for pigment analysis. Collecting minuscule amounts of pigment material from precious works of art by means of a cotton swab is a well-accepted sampling method, but poses specific challenges when TXRF is to be used for the characterization of the unknown material. (orig.)

Analysis of thin-film polymers using attenuated total internal reflection-Raman microspectroscopy.

Science.gov (United States)

Tran, Willie; Tisinger, Louis G; Lavalle, Luis E; Sommer, André J

2015-01-01

Two methods commonly employed for molecular surface analysis and thin-film analysis of microscopic areas are attenuated total reflection infrared (ATR-IR) microspectroscopy and confocal Raman microspectroscopy. In the former method, the depth of the evanescent probe beam can be controlled by the wavelength of light, the angle of incidence, or the refractive index of the internal reflection element. Because the penetration depth is proportional to the wavelength of light, one could interrogate a smaller film thickness by moving from the mid-infrared region to the visible region employing Raman spectroscopy. The investigation of ATR Raman microspectroscopy, a largely unexplored technique available to Raman microspectroscopy, was carried out. A Renishaw inVia Raman microscope was externally modified and used in conjunction with a solid immersion lens (SIL) to perform ATR Raman experiments. Thin-film polymer samples were analyzed to explore the theoretical sampling depth for experiments conducted without the SIL, with the SIL, and with the SIL using evanescent excitation. The feasibility of micro-ATR Raman was examined by collecting ATR spectra from films whose thickness measured from 200 to 60 nm. Films of these thicknesses were present on a much thicker substrate, and features from the underlying substrate did not become visible until the thin film reached a thickness of 68 nm.

Analysis of archaeological ceramics by total-reflection X-ray fluorescence: Quantitative approaches

International Nuclear Information System (INIS)

Fernandez-Ruiz, R.; Garcia-Heras, M.

2008-01-01

This paper reports the quantitative methodologies developed for the compositional characterization of archaeological ceramics by total-reflection X-ray fluorescence at two levels. A first quantitative level which comprises an acid leaching procedure, and a second selective level, which seeks to increase the number of detectable elements by eliminating the iron present in the acid leaching procedure. Total-reflection X-ray fluorescence spectrometry has been compared, at a quantitative level, with Instrumental Neutron Activation Analysis in order to test its applicability to the study of this kind of materials. The combination of a solid chemical homogenization procedure previously reported with the quantitative methodologies here presented allows the total-reflection X-ray fluorescence to analyze 29 elements with acceptable analytical recoveries and accuracies

Analysis of archaeological ceramics by total-reflection X-ray fluorescence: Quantitative approaches

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Ruiz, R. [Servicio Interdepartamental de Investigacion, Facultad de Ciencias, Universidad Autonoma de Madrid, Modulo C-9, Laboratorio de TXRF, Crta. Colmenar, Km 15, Cantoblanco, E-28049, Madrid (Spain)], E-mail: ramon.fernandez@uam.es; Garcia-Heras, M. [Grupo de Arqueometria de Vidrios y Materiales Ceramicos, Instituto de Historia, Centro de Ciencias Humanas y Sociales, CSIC, C/ Albasanz, 26-28, 28037 Madrid (Spain)

2008-09-15

This paper reports the quantitative methodologies developed for the compositional characterization of archaeological ceramics by total-reflection X-ray fluorescence at two levels. A first quantitative level which comprises an acid leaching procedure, and a second selective level, which seeks to increase the number of detectable elements by eliminating the iron present in the acid leaching procedure. Total-reflection X-ray fluorescence spectrometry has been compared, at a quantitative level, with Instrumental Neutron Activation Analysis in order to test its applicability to the study of this kind of materials. The combination of a solid chemical homogenization procedure previously reported with the quantitative methodologies here presented allows the total-reflection X-ray fluorescence to analyze 29 elements with acceptable analytical recoveries and accuracies.

Small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry.

Science.gov (United States)

Wang, Shinn-Fwu; Chiu, Ming-Hung; Chen, Wei-Wu; Kao, Fu-Hsi; Chang, Rong-Seng

2009-05-01

A small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry is proposed. In this paper, a small displacement can be obtained only by measuring the variation in phase difference between s- and p-polarization states for the total internal reflection effect. In order to improve the sensitivity, we increase the number of total internal reflections by using a parallelogram prism. The theoretical resolution of the method is better than 0.417 nm. The method has some merits, e.g., high resolution, high sensitivity, and real-time measurement. Also, its feasibility is demonstrated.

Fish samples as bioindicator of environmental quality: synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

International Nuclear Information System (INIS)

Vives, Ana Elisa Sirito de; Moreira, Silvana; Brienza, Sandra Maria Boscolo; Zucchi, Orgheda Luiza Araujo Domingues; Nascimento Filho, Virgilio Franco do Centro de Energia Nuclear na Agricultura , Piracicaba, SP; Brazil)

2005-01-01

In this study fish were used as bioindicators of environmental contamination. The species were collected in Piracicaba River, Sao Paulo state, Brazil and the toxic elements concentrations were determined in muscle tissue and viscus (liver, intestine and stomach) by Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SR-TXRF). Were determined the elements Ti, Cr, Mn, Fe, Ni, Cu, Zn and Ba. The results were compared with values established by Brazilian Legislation for general food. The elements concentrations evidenced potential risk to human health and environmental quality alteration of the studied area. The measurements were realized at the 'Laboratorio Nacional de Luz Sincrotron' (LNLS) located in Campinas, Sao Paulo State, Brazil. (author)

Fish samples as bioindicator of environmental quality: synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

Energy Technology Data Exchange (ETDEWEB)

Vives, Ana Elisa Sirito de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Brienza, Sandra Maria Boscolo [Universidade Metodista de Piracicaba (UNIMEP), SP (Brazil). Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Zucchi, Orgheda Luiza Araujo Domingues [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: virgilio@cena.usp.br

2005-07-01

In this study fish were used as bioindicators of environmental contamination. The species were collected in Piracicaba River, Sao Paulo state, Brazil and the toxic elements concentrations were determined in muscle tissue and viscus (liver, intestine and stomach) by Synchrotron Radiation Total Reflection X-Ray Fluorescence Analysis (SR-TXRF). Were determined the elements Ti, Cr, Mn, Fe, Ni, Cu, Zn and Ba. The results were compared with values established by Brazilian Legislation for general food. The elements concentrations evidenced potential risk to human health and environmental quality alteration of the studied area. The measurements were realized at the 'Laboratorio Nacional de Luz Sincrotron' (LNLS) located in Campinas, Sao Paulo State, Brazil. (author)

Total internal reflection second-harmonic generation: probing the alkane water interface

International Nuclear Information System (INIS)

Conboy, J.C.; Daschbach, J.L.; Richmond, G.L.

1994-01-01

Total internal reflection Second-Harmonic Generation (SHG) has been used to study a series of neat n-alkane/water interfaces. Polarization and incident angular-dependent measurements of the SH response show good agreement with theoretical predictions. Analysis of the incident and polarization angular-dependent SH response allows for determination of the nonlinear optical properties of molecules comprising the interfacial region. Based on Kleinman symmetry, the measured surface nonlinear susceptibilities suggest a high degree of interfacial order for octane and decane with less order indicated by the odd carbon n-alkanes examined, heptane and nonane. The SH response in reflection and transmission has been measured under a Total Internal Reflection (TIR) of the fundamental. The measured nonlinear susceptibilities in each case are found to be identical. (orig.)

Quality Control of Valerianae Radix by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) Spectroscopy.

Science.gov (United States)

Nikzad-Langerodi, Ramin; Arth, Katharina; Klatte-Asselmeyer, Valerie; Bressler, Sabine; Saukel, Johannes; Reznicek, Gottfried; Dobeš, Christoph

2018-04-01

(Acetoxy-)valerenic acid and total essential oil content are important quality attributes of pharmacy grade valerian root (Valerianae radix). Traditional analysis of these quantities is time-consuming and necessitates (harmful) solvents. Here we investigated an application of attenuated total reflection Fourier transform infrared spectroscopy for extractionless analysis of these quality attributes on a representative sample comprising 260 wild-crafted individuals covering the Central European taxonomic diversity of the Valeriana officinalis L. s. l. species aggregate with its three major ploidy cytotypes (i.e., di-, tetra- and octoploid). Calibration models were built by orthogonal partial least squares regression for quantitative analysis of (acetoxy-)valerenic acid and total essential oil content. For the latter, we propose a simplistic protocol involving apolar extraction followed by gas chromatography as a reference method for multivariate calibration in order to handle the analysis of samples taken from individual plants. We found good predictive ability of chemometric models for quantification of valerenic acid, acetoxyvalerenic acid, total sesquiterpenoid acid, and essential oil content with a root mean squared error of cross-validation of 0.064, 0.043, and 0.09 and root mean squared error of prediction of 0.066, 0.057, and 0.09 (% content), respectively. Orthogonal partial least squares discriminant analysis revealed good discriminability between the most productive phenotype (i.e., the octoploid cytotype) in terms of sesquiterpenoid acids, and the less productive ones (i.e., di- and tetraploid). All in all, our results demonstrate the application of attenuated total reflection Fourier transform infrared spectroscopy for rapid, extractionless estimation of the most important quality attributes of valerian root and minimally invasive identification of the most productive phenotype in terms of sesquiterpenoid acids. Georg Thieme Verlag KG Stuttgart · New

Precise shape reconstruction by active pattern in total-internal-reflection-based tactile sensor.

Science.gov (United States)

Saga, Satoshi; Taira, Ryosuke; Deguchi, Koichiro

2014-03-01

We are developing a total-internal-reflection-based tactile sensor in which the shape is reconstructed using an optical reflection. This sensor consists of silicone rubber, an image pattern, and a camera. It reconstructs the shape of the sensor surface from an image of a pattern reflected at the inner sensor surface by total internal reflection. In this study, we propose precise real-time reconstruction by employing an optimization method. Furthermore, we propose to use active patterns. Deformation of the reflection image causes reconstruction errors. By controlling the image pattern, the sensor reconstructs the surface deformation more precisely. We implement the proposed optimization and active-pattern-based reconstruction methods in a reflection-based tactile sensor, and perform reconstruction experiments using the system. A precise deformation experiment confirms the linearity and precision of the reconstruction.

Nanograting-based plasmon enhancement for total internal reflection fluorescence microscopy of live cells

International Nuclear Information System (INIS)

Kim, Kyujung; Cho, Eun-Jin; Suh, Jin-Suck; Huh, Yong-Min; Kim, Donghyun; Kim, Dong Jun

2009-01-01

We investigated evanescent field enhancement based on subwavelength nanogratings for improved sensitivity in total internal reflection microscopy of live cells. The field enhancement is associated with subwavelength-grating-coupled plasmon excitation. An optimum sample employed a silver grating on a silver film and an SF10 glass substrate. Field intensity was enhanced by approximately 90% when measured by fluorescent excitation of microbeads relative to that on a bare prism as a control, which is in good agreement with numerical results. The subwavelength-grating-mediated field enhancement was also applied to live cell imaging of quantum dots, which confirmed the sensitivity enhancement qualitatively.

Attenuated total internal reflection infrared microspectroscopic imaging using a large-radius germanium internal reflection element and a linear array detector.

Science.gov (United States)

Patterson, Brian M; Havrilla, George J

2006-11-01

The number of techniques and instruments available for Fourier transform infrared (FT-IR) microspectroscopic imaging has grown significantly over the past few years. Attenuated total internal reflectance (ATR) FT-IR microspectroscopy reduces sample preparation time and has simplified the analysis of many difficult samples. FT-IR imaging has become a powerful analytical tool using either a focal plane array or a linear array detector, especially when coupled with a chemometric analysis package. The field of view of the ATR-IR microspectroscopic imaging area can be greatly increased from 300 x 300 microm to 2500 x 2500 microm using a larger internal reflection element of 12.5 mm radius instead of the typical 1.5 mm radius. This gives an area increase of 70x before aberrant effects become too great. Parameters evaluated include the change in penetration depth as a function of beam displacement, measurements of the active area, magnification factor, and change in spatial resolution over the imaging area. Drawbacks such as large file size will also be discussed. This technique has been successfully applied to the FT-IR imaging of polydimethylsiloxane foam cross-sections, latent human fingerprints, and a model inorganic mixture, which demonstrates the usefulness of the method for pharmaceuticals.

Characterization and classification of spirituous beverages by total reflection x-ray fluorescence

International Nuclear Information System (INIS)

Davila, E.G. de; Lue-Meru, M.P.; Capote, T.; Greaves, E.

2000-01-01

The total reflection x-ray fluorescence (TXRF) technique was applied for the multi-elemental analysis of spirituous beverages like rum, cocuy (typical spirituous beverage in Venezuela), whiskey and wine, in order to classify the samples by product processing and geographical origin by chemometric analysis. Special attention was paid to the cocuy samples, since there is a lack of quality control of this beverage, mainly due to the home-made product processing. The use of the Compton peak information was evaluated for the determination of organic content in samples. In the specifically case of cocuy samples the Compton peak area was correlated to the ash content for detection of adulteration with sugar syrup. Cocuy samples were also analyzed using gas chromatography, for pH, acidity, ash content and refractometry, in order to develop the recognition pattern. The TXRF analysis was carried out in a Canberra spectrometer, using the K α-line of a Motube, by a direct procedure previously developed. The analysis of the data was done by using principal components analysis and a confidence test. The results show that TXRF and chemometric analysis is a useful tool for quality control of spirituous beverages, not only concerning to metal content, but also in the evaluation of sugar and non volatile organic content. (author)

Characterization and classification of spirituous beverages by total reflection x-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Davila, E.G. de [Univerisdad Centroccidental Lisandro Alvarado, Decanato de Agronomia, Dpto. de Quimica y Suelos. Nucleo Tarabana, cabudare, Edo. Lara (Venezuela); Lue-Meru, M P; Capote, T [Univerisdad Centroccidental Lisandro Alvarado, Decanato de Agronomia, Dpto. de Quimica y Suelos. Nucleo Tarabana, Cabudare, Edo. Lara (Venezuela); Universidad Simon Bolivar, Dpto. de Quimica, Lab. Espectroscopia Atomica, Sartenejas, Baruta, Edo. Miranda (Venezuela); Greaves, E [Universidad Simon Bolivar, Dpto. de Fisica, Sartenejas, Baruta, Edo. Miranda (Venezuela)

2000-07-01

The total reflection x-ray fluorescence (TXRF) technique was applied for the multi-elemental analysis of spirituous beverages like rum, cocuy (typical spirituous beverage in Venezuela), whiskey and wine, in order to classify the samples by product processing and geographical origin by chemometric analysis. Special attention was paid to the cocuy samples, since there is a lack of quality control of this beverage, mainly due to the home-made product processing. The use of the Compton peak information was evaluated for the determination of organic content in samples. In the specifically case of cocuy samples the Compton peak area was correlated to the ash content for detection of adulteration with sugar syrup. Cocuy samples were also analyzed using gas chromatography, for pH, acidity, ash content and refractometry, in order to develop the recognition pattern. The TXRF analysis was carried out in a Canberra spectrometer, using the K {alpha}-line of a Motube, by a direct procedure previously developed. The analysis of the data was done by using principal components analysis and a confidence test. The results show that TXRF and chemometric analysis is a useful tool for quality control of spirituous beverages, not only concerning to metal content, but also in the evaluation of sugar and non volatile organic content. (author)

Proposed frustrated-total-reflection acoustic sensing method

International Nuclear Information System (INIS)

Hull, J.R.

1981-01-01

Modulation of electromagnetic energy transmission through a frustrated-total-reflection device by pressure-induced changes in the index of refraction is proposed for use as an acoustic detector. Maximum sensitivity occurs for angles of incidence near the critical angle. The minimum detectable pressure in air is limited by Brownian noise. Acoustic propagation losses and diffraction of the optical beam by the acoustic signal limit the minimum acoustic wavelength to lengths of the order of the spatial extent of the optical beam. The response time of the method is fast enough to follow individual acoustic waves

Total reflection X-ray fluorescence analysis of river waters in its stream across the city of Cordoba, in Argentina

International Nuclear Information System (INIS)

Valentinuzzi, M.C.; Sanchez, H.J.; Abraham, J.

2006-01-01

The aim of this work was to analyze the composition of river waters and to study their quality by detecting possible contaminants. The samples were taken at 32 points of the Suquia River in its stream across the city of Cordoba (in the Province of Cordoba, Argentina). The samples were analyzed with total reflection X-ray fluorescence (TXRF) using beam guides. Beam guides made of two Si plate reflectors were used as sample carriers and to guide the X-ray photons to the sample; the measurements were taken using the characteristic configuration that ensures the best excitation and detection conditions (in TXRF). The analyses were carried out by preconcentration of the water samples and by adding an internal standard (Gallium); small amounts of samples (30 μl) were deposited on the Si reflector plate and they were then analyzed in the total reflection regime. Spectra were analyzed with standard methods using conventional programs. The results show interesting behaviors of the concentration of trace elements along the river: elements of low atomic number (such as Ca, Cl, S, K) present higher concentrations as compared to high Z elements (such as Fe, Zn, Br, Sr); the concentrations of light elements follow a similar behavior along the stream, the same situation is observed in the set of elements with high atomic number. Some samples present high concentrations in certain elements indicating possible sources of contamination

Common-path configuration in total internal reflection digital holography microscopy.

Science.gov (United States)

Calabuig, Alejandro; Matrecano, Marcella; Paturzo, Melania; Ferraro, Pietro

2014-04-15

Total Internal Reflection Digital Holographic Microscopy (TIRDHM) is recognized to be a powerful tool for retrieving quantitative phase images of cell-substrate interfaces, adhesions, and tissue structures close to the prism surface. In this Letter, we develop an improved TIRDHM system, taking advantage of a refractive index mismatch between the prism and the sample substrate, to allow phase-shifting DH with just a single-beam interferometric configuration. Instead of the traditional off-axis method, phase-shift method is used to retrieve amplitude and phase images in coherent light and TIR modality. Essentially, the substrate-prism interface acts like a beam splitter generating a reference beam, where the phase-shift dependence on the incident angle is exploited in this common-path configuration. With the aim to demonstrate the technique's validity, some experiments are performed to establish the advantage of this compact and simple configuration, in which the reference arm in the setup is avoided.

An Arduino-Based Experiment Designed to Clarify the Transition to Total Internal Reflection

Science.gov (United States)

Atkin, Keith

2018-01-01

The topic of refraction and reflection of light at the boundary of transparent media is a fundamentally important one. The special case of total internal reflection is however commonly misrepresented in elementary textbooks. This paper addresses the problem and describes an experimental procedure for measuring and displaying reflected and…

Recent Developments in Solid-Phase Extraction for Near and Attenuated Total Reflection Infrared Spectroscopic Analysis

Directory of Open Access Journals (Sweden)

Christian W. Huck

2016-05-01

Full Text Available A review with more than 100 references on the principles and recent developments in the solid-phase extraction (SPE prior and for in situ near and attenuated total reflection (ATR infrared spectroscopic analysis is presented. New materials, chromatographic modalities, experimental setups and configurations are described. Their advantages for fast sample preparation for distinct classes of compounds containing different functional groups in order to enhance selectivity and sensitivity are discussed and compared. This is the first review highlighting both the fundamentals of SPE, near and ATR spectroscopy with a view to real sample applicability and routine analysis. Most of real sample analyses examples are found in environmental research, followed by food- and bioanalysis. In this contribution a comprehensive overview of the most potent SPE-NIR and SPE-ATR approaches is summarized and provided.

Determination of carbon in natural freshwater biofilms with total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Ovari, M.; Streli, C.; Wobrauschek, P.; Zaray, Gy.

2009-01-01

There is a growing interest in determination of low Z elements, i.e., carbon to phosphorus, in biological samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). Biofilms can be used for biomonioring purposes in the aquatic environment. Besides the trace metals, especially the determination of the carbon content is important for the better understanding of the early stage of biofilm formation. For this, an ATI low Z spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a Si(Li) detector with ultra thin window was used. Biofilms were grown on two different artificial supports (granite and plexiglass), freeze dried, suspended in high purity water and analyzed. As an internal standard the natural titanium content of the biofilms was used. The accuracy of the method was checked by total carbon measurement using a combusting carbon analyzer.

Determination of carbon in natural freshwater biofilms with total reflection X-ray fluorescence spectrometry

Energy Technology Data Exchange (ETDEWEB)

Ovari, M. [Department of Analytical Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary)], E-mail: ovari@chem.elte.hu; Streli, C.; Wobrauschek, P. [Atominstitut of the Austrian Universities, TU-Wien, Stadionallee 2, A-1020, Wien (Austria); Zaray, Gy. [Department of Analytical Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary); Cooperative Research Centre of Environmental Chemistry, Eoetvoes University, Budapest, H-1117, Budapest, Pazmany Peter stny. 1/a. (Hungary)

2009-08-15

There is a growing interest in determination of low Z elements, i.e., carbon to phosphorus, in biological samples. Total reflection X-ray fluorescence spectrometry (TXRF) has been already established as suitable trace element analytical method with low sample demand and quite good quantification limits. Recently, the determinable element range was extended towards Z = 6 (carbon). Biofilms can be used for biomonioring purposes in the aquatic environment. Besides the trace metals, especially the determination of the carbon content is important for the better understanding of the early stage of biofilm formation. For this, an ATI low Z spectrometer equipped with Cr-anode X-ray tube, multilayer monochromator, vacuum chamber, and a Si(Li) detector with ultra thin window was used. Biofilms were grown on two different artificial supports (granite and plexiglass), freeze dried, suspended in high purity water and analyzed. As an internal standard the natural titanium content of the biofilms was used. The accuracy of the method was checked by total carbon measurement using a combusting carbon analyzer.

Characterization of southern yellow pine bark layers by Attenuated Total Reflectance (ATR) and Fourier Transform Infrared (FT-IR) Spectroscopy

Science.gov (United States)

Thomas L. Eberhardt

2009-01-01

The outer bark (rhytidome) of the southern yellow pines is a complex structure comprised of alternating layers of obliterated phloem and periderm tissues, with the latter comprised of three layers, those being phellem, phellogen, and phelloderm. An attenuated total reflectance (ATR) sampling accessory, coupled with a Fourier transform infrared (FTIR) spectrometer,...

Total internal reflection tomography of small objects

International Nuclear Information System (INIS)

Chen Xudong

2008-01-01

The multiple signal classification (MUSIC) imaging method is applied to determine the locations of a collection of small anisotropic spherical scatterers in the framework of the total internal reflection tomography. Multiple scattering between scatterers is considered and the inverse scattering problem is nonlinear, which, however, is solved by the proposed fast analytical approach where no associated forward problem is iteratively evaluated. The paper also discusses the role of the polarization of incidence waves, the incidence angle, the separation of scatterers from the surface of the substrate, and the level of noise on the resolution of imaging.

Simulation of attenuated total reflection infrared absorbance spectra: applications to automotive clear coat forensic analysis.

Science.gov (United States)

Lavine, Barry K; Fasasi, Ayuba; Mirjankar, Nikhil; Nishikida, Koichi; Campbell, Jay

2014-01-01

Attenuated total reflection (ATR) is a widely used sampling technique in infrared (IR) spectroscopy because minimal sample preparation is required. Since the penetration depth of the ATR analysis beam is quite shallow, the outer layers of a laminate or multilayered paint sample can be preferentially analyzed with the entire sample intact. For this reason, forensic laboratories are taking advantage of ATR to collect IR spectra of automotive paint systems that may consist of three or more layers. However, the IR spectrum of a paint sample obtained by ATR will exhibit distortions, e.g., band broadening and lower relative intensities at higher wavenumbers, compared with its transmission counterpart. This hinders library searching because most library spectra are measured in transmission mode. Furthermore, the angle of incidence for the internal reflection element, the refractive index of the clear coat, and surface contamination due to inorganic contaminants can profoundly influence the quality of the ATR spectrum obtained for automotive paints. A correction algorithm to allow ATR spectra to be searched using IR transmission spectra of the paint data query (PDQ) automotive database is presented. The proposed correction algorithm to convert transmission spectra from the PDQ library to ATR spectra is able to address distortion issues such as the relative intensities and broadening of the bands, and the introduction of wavelength shifts at lower frequencies, which prevent library searching of ATR spectra using archived IR transmission data.

Determination of calcium, potassium, manganese, iron, copper and zinc levels in representative samples of two onion cultivars using total reflection X-ray fluorescence and ultrasound extraction procedure

International Nuclear Information System (INIS)

Alvarez, J.; Marco, L.M.; Arroyo, J.; Greaves, E.D.; Rivas, R.

2003-01-01

The chemical characterization of onion cultivar samples is an important tool for the enhancement of their productivity due to the fact that chemical composition is closed related to the quality of the products. A new sample preparation procedure for elemental characterization is proposed, involving the acid extraction of the analytes from crude samples by means of an ultrasonic bath, avoiding the required digestion of samples in vegetable tissue analysis. The technique of total reflection X-ray fluorescence (TXRF) was successfully applied for the simultaneous determination of the elements Ca, K, Mn, Fe, Cu and Zn. The procedure was compared with the wet ashing and dry ashing procedures for all the elements using multivariate analysis and the Scheffe test. The technique of flame atomic absorption spectrometry (FAAS) was employed for comparison purposes and accuracy evaluation of the proposed analysis method. A good agreement between the two techniques was found when using the dry ashing and ultrasound leaching procedures. The levels of each element found for representative samples of two onion cultivars (Yellow Granex PRR 502 and 438 Granex) were also compared by the same method. Levels of K, Mn and Zn were significantly higher in the 438 Granex cultivar, while levels of Ca, Fe and Cu were significantly higher in the Yellow Granex PRR 502 cultivar

Analysis of total oil and fatty acids composition by near infrared reflectance spectroscopy in edible nuts

Science.gov (United States)

Kandala, Chari V.; Sundaram, Jaya

2014-10-01

Near Infrared (NIR) Reflectance spectroscopy has established itself as an important tool in quantifying water and oil present in various food materials. It is rapid and nondestructive, easier to use, and does not require processing the samples with corrosive chemicals that would render them non-edible. Earlier, the samples had to be ground into powder form before making any measurements. With the development of new soft ware packages, NIR techniques could now be used in the analysis of intact grain and nuts. While most of the commercial instruments presently available work well with small grain size materials such as wheat and corn, the method present here is suitable for large kernel size products such as shelled or in-shell peanuts. Absorbance spectra were collected from 400 nm to 2500 nm using a NIR instrument. Average values of total oil contents (TOC) of peanut samples were determined by standard extraction methods, and fatty acids were determined using gas chromatography. Partial least square (PLS) analysis was performed on the calibration set of absorption spectra, and models were developed for prediction of total oil and fatty acids. The best model was selected based on the coefficient of determination (R2), Standard error of prediction (SEP) and residual percent deviation (RPD) values. Peanut samples analyzed showed RPD values greater than 5.0 for both absorbance and reflectance models and thus could be used for quality control and analysis. Ability to rapidly and nondestructively measure the TOC, and analyze the fatty acid composition, will be immensely useful in peanut varietal improvement as well as in the grading process of grain and nuts.

Trace element analysis of mineral and tap water samples using total reflection x-ray fluorescence (TXRF)

International Nuclear Information System (INIS)

Mangala, M.J.; Korir, K.A.; Maina, D.M.; Kinyua, A.M.

2000-01-01

Results of trace element analysis by TXRF of tap water and various brands of bottled mineral water samples which are representative of local and imported brands sold in Nairobi are reported. The variation in elemental concentrations in water samples analyzed were as follows: potassium (K) 0.2 to 28.9 μg/ml; calcium (Ca) 2.2 to 120 μg/ml; titanium (Ti) 11 to 60 μg/l; manganese (Mn) 8 to 670 μg/l; iron (Fe) 31 to 540 μg/l; copper (Cu) 8 to 30 μg/l; zinc (Zn) 8 to 4730 μg/l; bromine (Br) 9 to 248 μg/l; rubidium (Rb) 10 to 40 μg/l and strontium (Sr) 10 to 1000 μg/l. Local mineral water samples contain higher levels of trace elements; manganese (Mn), zinc (Zn), bromine (Br), rubidium (Rb) and strontium (Sr) as compared to the imported brands. Principal component analysis of the results revealed three component loading factors clusters for: rubidium (Rb), strontium (Sr) and calcium (Ca); titanium (Ti), iron (Fe), bromine (Br), and zinc (Zn); zinc (Zn), manganese (Mn) and potassium (K) respectively. The percentage of total variance explained by the components was 31.4, 27.3, and 14.8 respectively. In this study, we also found that a limited spread of 5-6 mm for a 10 μl sample was achieved when the quartz sample carrier was dried in a low pressure (300 mbar) oven at 70 o C for 10 hours. (author)

Neutron reflection effect on total absorption detector method used in SWINPC neutron multiplication experiment for beryllium

International Nuclear Information System (INIS)

Tian Dongfeng; Ho Yukun; Yang Fujia

2001-01-01

The SWINPC integral experiment on neutron multiplication in bulk beryllium showed that there were marked discrepancies between experimental data and calculated values with the ENDF/B-VI data. The calculated values become higher than experimental ones as the sample thickness increases. Several works had been devoted to find problems existing in the experiment. This paper discusses the neutron reflection effect on the total absorption detector method which was used in the experiment to measure the neutron leakage from samples. One systematic correction is suggested to make the experimental values agree with the calculated ones with the ENDF/B-VI data within experimental errors. (author)

Determination of technetium by total reflection x-ray fluorescence

International Nuclear Information System (INIS)

Bermudez, J.I.; Greaves, E.D.; Nemeth, P.

2000-01-01

We describe a technique using total reflection x-ray fluorescence (TXRF) for determination of Technetium produced by elution of chromatography generators with physiological saline solutions. The analysis with the 18.41 keV K α line of Technetium was accomplished with monochromatized K α radiation from a silver anode x-ray tube operated at 45 keV and 20 mA. This radiation at 22.104 keV is efficiently coupled to the 21.054 keV absorption edge of Tc. It is also of advantage in the direct analysis of organic and saline properties of the Tc-bearing samples. Quantification was accomplished by internal standard addition of Ga and using an interpolated value of the sensitivity for Tc between Molybdenum and Rhenium. Data processing was carried out with the QXAS-AXIL software package. System sensitivity was found adequate for direct Tc determination of eluted saline solutions. The interest and advantages of the use of the technique as an auxiliary in the synthesis and characterization of Tc-labeled radiopharmaceuticals used for diagnosis in nuclear medicine are discussed. Detection limits in the matrices analyzed are reported. (author)

Widefield and total internal reflection fluorescent structured illumination microscopy with scanning galvo mirrors

Science.gov (United States)

Chen, Youhua; Cao, Ruizhi; Liu, Wenjie; Zhu, Dazhao; Zhang, Zhiming; Kuang, Cuifang; Liu, Xu

2018-04-01

We present an alternative approach to realize structured illumination microscopy (SIM), which is capable for live cell imaging. The prototype utilizes two sets of scanning galvo mirrors, a polarization converter and a piezo-platform to generate a fast shifted, s-polarization interfered and periodic variable illumination patterns. By changing the angle of the scanning galvanometer, we can change the position of the spots at the pupil plane of the objective lens arbitrarily, making it easy to switch between widefield and total internal reflection fluorescent-SIM mode and adapting the penetration depth in the sample. Also, a twofold resolution improvement is achieved in our experiments. The prototype offers more flexibility of pattern period and illumination orientation changing than previous systems.

Determination of mercury in seawater by total reflection x-ray fluorescence spectrometry after an electrochemical preconcentration method

International Nuclear Information System (INIS)

Ritschel, A.; Chinea Cano, E.; Wobrauschek, P.; Kuntner, C.; Durakbasa, M.N.

2000-01-01

A new combined method of electrodeposition of trace elements on metallic plates with subsequent total-reflection x-ray fluorescence spectrometry (TXRF) is proposed for the determination of trace metals in natural waters. The elements of interest are electroplated on highly polished niobium discs which are used as sample carriers for the TXRF measurement. The electrochemical preconcentration is performed in a flow cell under a controlled working electrode potential. The preconcentration step involves only very little manipulation which minimizes the risk of contamination of the sample. The method was investigated by analyzing inorganic mercury in sea water. A detection limit of 7 ngl -1 could be achieved for mercury in a 40 ml sea water sample. (author)

The effect of surface texture on total reflection of neutrons and X-rays from modified interfaces

DEFF Research Database (Denmark)

Goldar, A.; Roser, S.J.; Hughes, A.

2002-01-01

X-ray and neutron scattering from macroscopically rough surfaces and interfaces is considered and a new method of analysis based on the variation of the shape of the total reflection edge in the reflectivity profile is proposed. It was shown that in the limit that the correlation length and the h......X-ray and neutron scattering from macroscopically rough surfaces and interfaces is considered and a new method of analysis based on the variation of the shape of the total reflection edge in the reflectivity profile is proposed. It was shown that in the limit that the correlation length...... and the height of the surface roughness are larger than the wavelength (at least 100 times bigger) of the incoming beam, the total reflection edge in the reflection profile becomes rounded. This technique allows direct analysis of the variation of the reflectivity pro le in terms of the structure of the surface...

Multielemental analysis in Brazilian cigarettes using total reflection X-ray fluorescence with synchrotron radiation

International Nuclear Information System (INIS)

Serpa, Renata F.B.; Jesus, Edgar F.O. de; Lopes, Ricardo T.; Moreira, Silvana

2005-01-01

In order to identify major and trace elements in conventional and light Brazilian cigarettes, Total Reflection X-Ray Fluorescence with Synchrotron Radiation (SR-TXRF) was used. The fluorescence measurements were carried out at Brazilian Synchrotron Light Laboratory, Campinas - Sao Paulo. This technique enables detection limit is in the ngg -1 range, which is very useful in elemental tobacco smoke analysis, since it presents most of its elements at a trace level. The major elements identified in tobacco samples were: S, Cl, K, Ca, Mn, Fe and Cd, and the trace elements were: Ti, Cr, Ni, Cu, Zn, Br, Rb, Sr and Ba. However in tobacco smoke samples, there were only two major elements: K and Ca, the others were present a trace level. The rate transfer of tobacco to tobacco smoke was about 2.5 % for all elements studied. (author)

Elemental concentration in normal skin and fibroepithelial polip lesions by synchrotron radiation total reflection X-ray fluorescence technique

International Nuclear Information System (INIS)

Soares, Julio C.A.C.R.; Canellas, Catarine G.L.; Lopes, Ricardo T.; Anjos, Marcelino J.

2011-01-01

In this work, the concentrations of trace elements were measured in acrochordon, a skin lesion also known as skin tag or fibroepithelial polyp, as well as in normal skin from the same patient. The samples were analysed by Synchrotron Radiation Total Reflection X- ray Fluorescence (SRTXRF) in the Synchrotron Light National Laboratory (LNLS) in Campinas/Sao Paulo-Brazil. The collection of lesion and healthy skin samples, including papillary dermis and epidermis, has involved 17 patients. It was evaluated the presence of P, S, Cl, K, Ca, Cr, Mn, Fe, Cu, Zn, Br and Rb in the paired samples, which were compared, and significant differences were found in some of them. (author)

Enhanced sensitivity to dielectric function and thickness of absorbing thin films by combining total internal reflection ellipsometry with standard ellipsometry and reflectometry

Science.gov (United States)

Lizana, A.; Foldyna, M.; Stchakovsky, M.; Georges, B.; Nicolas, D.; Garcia-Caurel, E.

2013-03-01

High sensitivity of spectroscopic ellipsometry and reflectometry for the characterization of thin films can strongly decrease when layers, typically metals, absorb a significant fraction of the light. In this paper, we propose a solution to overcome this drawback using total internal reflection ellipsometry (TIRE) and exciting a surface longitudinal wave: a plasmon-polariton. As in the attenuated total reflectance technique, TIRE exploits a minimum in the intensity of reflected transversal magnetic (TM) polarized light and enhances the sensitivity of standard methods to thicknesses of absorbing films. Samples under study were stacks of three films, ZnO : Al/Ag/ZnO : Al, deposited on glass substrates. The thickness of the silver layer varied from sample to sample. We performed measurements with a UV-visible phase-modulated ellipsometer, an IR Mueller ellipsometer and a UV-NIR reflectometer. We used the variance-covariance formalism to evaluate the sensitivity of the ellipsometric data to different parameters of the optical model. Results have shown that using TIRE doubled the sensitivity to the silver layer thickness when compared with the standard ellipsometry. Moreover, the thickness of the ZnO : Al layer below the silver layer can be reliably quantified, unlike for the fit of the standard ellipsometry data, which is limited by the absorption of the silver layer.

Sweeping total reflection X-ray fluorescence optimisation to monitor the metallic contamination into IC manufacturing

International Nuclear Information System (INIS)

Borde, Yannick; Danel, Adrien; Roche, Agnes; Veillerot, Marc

2008-01-01

Among the methods available on the market today to control as metallic contamination in integrated circuit manufacturing, Sweeping Total reflection X-ray Fluorescence mode appears a very good method, providing fast and entire wafer mapping. With the goal of a pertinent use of Sweeping Total reflection X-ray Fluorescence in advanced Integrated Circuit manufacturing this work discusses how acceptable levels of contamination specified by the production (low levels to be detected) can be taken into account. The relation between measurement results (surface coverage, throughput, low limit of detection, limit of quantification, quantification of localized contamination) and Sweeping Total reflection X-ray Fluorescence parameters (number of measurement points and integration time per point) is presented in details. In particular, a model is proposed to explain the mismatch between actual surface contamination in a localized spot on wafer and Total reflection X-ray Fluorescence reading. Both calibration and geometric issues have been taken into account

Characterization of Printing Inks Using DART-Q-TOF-MS and Attenuated Total Reflectance (ATR) FTIR.

Science.gov (United States)

Williamson, Rhett; Raeva, Anna; Almirall, Jose R

2016-05-01

The rise in improved and widely accessible printing technology has resulted in an interest to develop rapid and minimally destructive chemical analytical techniques that can characterize printing inks for forensic document analysis. Chemical characterization of printing inks allows for both discrimination of inks originating from different sources and the association of inks originating from the same source. Direct analysis in real-time mass spectrometry (DART-MS) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used in tandem to analyze four different classes of printing inks: inkjets, toners, offset, and intaglio. A total of 319 samples or ~ 80 samples from each class were analyzed directly on a paper substrate using the two methods. DART-MS was found to characterize the semi-volatile polymeric vehicle components, while ATR-FTIR provided chemical information associated with the bulk components of these inks. Complimentary data results in improved discrimination when both techniques are used in succession resulting in >96% discrimination for all toners, 95% for all inkjets, >92% for all offset, and >54% for all intaglio inks. © 2016 American Academy of Forensic Sciences.

Beer analysis by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF)

International Nuclear Information System (INIS)

Moreira, Silvana; Vives, Ana Elisa S. de; Nascimento Filho, Virgilio F.; Zucchi, Orgheda L.D.A.

2005-01-01

In this work the concentrations of P, S, Cl, K, Ca, Mn, Fe, Zn and Br in twenty-nine brands of national and international beers were determined by Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF). The results were compared with the limits established by the Brazilian Legislation and the nutritive values established by National Agricultural Library (NAL). The measurements were performed at the X-ray Fluorescence Beamline at Synchrotron Light Source Laboratory, in Campinas, Sao Paulo, Brazil, using a polychromatic beam for excitation. A small volume of 5 μL of sample beers containing just an internal standard, used to correct geometry effects, were analyzed without any pre-treatment. The measuring time was 100 s and the detection limits obtained varied from 1μg.L -1 for Mn and Fe to 15μg.L -1 for P. (author)

Intra-Cavity Total Reflection For High Sensitivity Measurement Of Optical Properties

Science.gov (United States)

Pipino, Andrew Charles Rule

1999-11-16

An optical cavity resonator device is provided for conducting sensitive murement of optical absorption by matter in any state with diffraction-limited spatial resolution through utilization of total internal reflection within a high-Q (high quality, low loss) optical cavity. Intracavity total reflection generates an evanescent wave that decays exponentially in space at a point external to the cavity, thereby providing a localized region where absorbing materials can be sensitively probed through alteration of the Q-factor of the otherwise isolated cavity. When a laser pulse is injected into the cavity and passes through the evanescent state, an amplitude loss resulting from absorption is incurred that reduces the lifetime of the pulse in the cavity. By monitoring the decay of the injected pulse, the absorption coefficient of manner within the evanescent wave region is accurately obtained from the decay time measurement.

Use of high-intensity sonication for pre-treatment of biological tissues prior to multielemental analysis by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

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

2012-01-01

In this work, two ultrasound-based procedures are developed for sample preparation prior to determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se and Sr in biological tissues by total reflection X-ray fluorescence spectrometry. Ultrasound-assisted extraction by means of a cup-horn sonoreactor and ultrasonic-probe slurry sampling were compared with a well-established procedure such as magnetic agitation slurry sampling. For that purpose, seven certified reference materials and different real samples of animal tissue were used. Similar accuracy and precision is obtained with the three sample preparation approaches tried. Limits of detection were dependent on both the sample matrix and the sample pre-treatment used, best values being achieved with ultrasound-assisted extraction. Advantages of ultrasound-assisted extraction include reduced sample handling, decreased contamination risks (neither addition of surfactants nor use of foreign objects inside the extraction vial), simpler background (no solid particles onto the sample carrier) and improved recovery for some elements such as P. A mixture of 10% v/v HNO 3 + 20–40% v/v HCl was suitable for extraction from biological tissues. - Highlights: ► We implement high-intensity sonication for pre-treatment of biological tissues. ► Multielemental analysis is performed by total reflection X-ray spectrometry. ► Ultrasound-based procedures are developed and compared to conventional slurry preparation. ► Features such as background, recovery and sample handling are favored by using ultrasonic extraction.

Attenuated total internal reflection infrared microscopy of multilayer plastic packaging foils.

Science.gov (United States)

van Dalen, Gerard; Heussen, Patricia C M; den Adel, Ruud; Hoeve, Robert B J

2007-06-01

Multilayer plastic foils are important packaging materials that are used to extend the shelf life of food products and drinks. Fourier transform infrared (FT-IR) spectroscopic imaging using attenuated total internal reflection (ATR) can be used for the identification and localization of different layers in multilayer foils. A new type of ATR crystal was used in combination with a linear array detector through which large sample areas (400 x 400 microm(2)) could be imaged with a pixel size of 1.6 microm. The method was tested on laminated plastic packing materials containing 5 to 12 layers. The results of the identification of the different materials using ATR-FT-IR were compared with differential scanning calorimetry (DSC) and the layer thickness of the individual layers measured by ATR-FT-IR was compared with polarized light microscopy (LM) and scanning electron microscopy (SEM). It has been demonstrated that individual layers with a thickness of about 3 microm could be identified in multilayer foils with a total thickness ranging from 100 to 150 microm. The results show a spatial resolution of about 4 microm (measured at wavenumbers ranging from 1000 to 1730 cm(-1)), which is about a factor of two better than can be obtained using transmission FT-IR imaging. An additional advantage of ATR is the ease of sample preparation. A good correspondence was found between visible and FT-IR images. The results of ATR-FT-IR imaging were in agreement with those obtained by LM, SEM, and DSC. ATR-FT-IR is superior to the combination of these techniques because it delivers both spatial and chemical information.

Investigation of polyelectrolytes by total reflection x-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Varga, I.; Nagy, M.

2000-01-01

Water soluble polyelectrolyte samples containing mono-, bi- and trivalent metal ions were investigated without any pretreatment. Acid digestion of linear polymers may lead to a product insoluble in water so the digestion has to be avoided. The aim of this paper was the determination of analytical characteristics and limitations of the total reflection x-ray fluorescence (TXRF) analysis for poly (vinylalcohol-vinylsulphate) salts and poly (acrylic acid, acrylamide) copolymers containing the following cations: K + , Cs + , Ba 2+ , Cu 2+ and La 3+ . On the basis of our results efficiency of ion-exchange during preparation of polyelectrolytes and stoichiometry of the end-product were determined. TXRF results were compared with data gained by inductively coupled plasma atomic emission spectrometry (ICP-AES) measurements except in the case of Cs + which has poor sensitivity in ICP-AES. Good agreement was found between the results of the two techniques and calculations from titrimetric data. Concentration of Li + and Mg 2+ in polymer samples was measured by ICP-AES. In majority of cases film-like dry residues of aqueous solutions of polyelectrolytes can be characterized by homogeneous spatial distribution of metal ions within the organic matrix. This is because the migration of the ions is hindered during drying process. Determination of metals in polyelectrolyte films by TXRF is quite ideal as model for analysis of plant, animal or human tissues which is a frequent task in environmental and inorganic biomedical analytical chemistry. (author)

Total-reflection x-ray fluorescence with a brillant undulator x-ray source

International Nuclear Information System (INIS)

Sakurai, K.; Eba, H.; Numako, C.; Suzuki, M.; Inoue, K.; Yagi, N.

2000-01-01

Total-reflection x-ray fluorescence (TXRF) is a highly sensitive technique for analyzing trace elements, because of the very low background from the sample support. Use of third-generation synchrotron x-ray source could further enhance the detection power. However, while such high sensitivity permits the detection of signals from trace elements of interest, it also means that one can observe weak parasitic x-rays as well. If the sample surface becomes even slightly contaminated, owing to air particulates near the beamline, x-ray fluorescence lines of iron, zinc, copper, nickel, chromium, and titanium can be observed even for a blank sample. Another critical problem is the low-energy-side tail of the scattering x-rays, which ultimately restricts the detection capability of the technique using a TXRF spectrometer based on a Si(Li) detector. The present paper describes our experiments with brilliant undulator x-ray beams at BL39XU and BL40XU, at the SPring-8, Harima, Japan. The emphasis is on the development of instruments to analyze a droplet of 0.1 μl containing trace elements of ppb level. Although the beamline is not a clean room, we have employed equipment for preparing a clean sample and also for avoiding contamination during transferring the sample into the spectrometer. We will report on the successful detection of the peak from 0.8 ppb selenium in a droplet (absolute amount 80 fg). We will also present the results of recent experiments obtained from a Johansson spectrometer rather than a Si(Li) detector. (author)

Enhanced sensitivity to dielectric function and thickness of absorbing thin films by combining total internal reflection ellipsometry with standard ellipsometry and reflectometry

International Nuclear Information System (INIS)

Lizana, A; Foldyna, M; Garcia-Caurel, E; Stchakovsky, M; Georges, B; Nicolas, D

2013-01-01

High sensitivity of spectroscopic ellipsometry and reflectometry for the characterization of thin films can strongly decrease when layers, typically metals, absorb a significant fraction of the light. In this paper, we propose a solution to overcome this drawback using total internal reflection ellipsometry (TIRE) and exciting a surface longitudinal wave: a plasmon-polariton. As in the attenuated total reflectance technique, TIRE exploits a minimum in the intensity of reflected transversal magnetic (TM) polarized light and enhances the sensitivity of standard methods to thicknesses of absorbing films. Samples under study were stacks of three films, ZnO : Al/Ag/ZnO : Al, deposited on glass substrates. The thickness of the silver layer varied from sample to sample. We performed measurements with a UV–visible phase-modulated ellipsometer, an IR Mueller ellipsometer and a UV–NIR reflectometer. We used the variance–covariance formalism to evaluate the sensitivity of the ellipsometric data to different parameters of the optical model. Results have shown that using TIRE doubled the sensitivity to the silver layer thickness when compared with the standard ellipsometry. Moreover, the thickness of the ZnO : Al layer below the silver layer can be reliably quantified, unlike for the fit of the standard ellipsometry data, which is limited by the absorption of the silver layer. (paper)

Total reflection X-ray fluorescence and archaeometry: Application in the Argentinean cultural heritage

Energy Technology Data Exchange (ETDEWEB)

Vazquez, Cristina [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina); Laboratorio de Quimica de Sistemas Heterogeneos, Facultad de Ingenieria, Universidad de Buenos Aires, P. Colon 850 (C1063ACU), Buenos Aires (Argentina)], E-mail: Cristina.Vazquez@cnea.gov.ar; Albornoz, Ana [Agencia Rio Negro Cultura, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Hajduk, Adam [CONICET, Museo de la Patagonia F.P.Moreno, Centro Civico s/n Bariloche, Rio Negro (Argentina); Elkin, Dolores [CONICET Instituto Nacional de Antropologia y Pensamiento Latinoamericano, 3 de febrero 1378 (C1426AEL) Buenos Aires (Argentina); Custo, Graciela; Obrustky, Alba [Comision Nacional de Energia Atomica, Av. Gral Paz 1499 (B1650KNA) San Martin, Buenos Aires (Argentina)

2008-12-15

Archaeometry is an interdisciplinary research area involved in the development and use of scientific methods in order to answer questions concerned with the human history. In this way the knowledge of archaeological objects through advanced chemical and physical analyses permits a better preservation and conservation of the cultural heritage and also reveals materials and technologies used in the past. In this sense, analytical techniques play an important role in order to provide chemical information about cultural objects. Considering the non destructive characteristic of this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Taking into account the irreplaceable character of the archaeological and artistic materials considered in this study, analytical techniques must be adequate in order to prevent any alteration or damage and in addition to allow the conservation of their integrity. Total Reflection X-ray Fluorescence Spectrometry as a geometric variant of conventional X-ray fluorescence is a proved microanalytical technique considering the small amount of sample required for the analysis. A few micrograms are enough in order to reveal valuable information about elemental composition and in this context it is highly recommended for artwork studies. In this paper a case study is presented in which Total Reflection X-Ray Fluorescence Spectrometry has been successfully employed in the archaeometry field. Examples from Argentinean cultural heritage sites related with the determination of pigments in paintings on canvas and in rock sites as well as in underwater archaeology research are shown.

Beer analysis by synchrotron radiation total reflection X-ray fluorescence (SR-TXRF)

Energy Technology Data Exchange (ETDEWEB)

Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br; Zucchi, Orgheda L.D.A. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas de Ribeirao Preto]. E-mail: olzucchi@fcfrp.usp.br

2005-07-01

In this work the concentrations of P, S, Cl, K, Ca, Mn, Fe, Zn and Br in twenty-nine brands of national and international beers were determined by Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF). The results were compared with the limits established by the Brazilian Legislation and the nutritive values established by National Agricultural Library (NAL). The measurements were performed at the X-ray Fluorescence Beamline at Synchrotron Light Source Laboratory, in Campinas, Sao Paulo, Brazil, using a polychromatic beam for excitation. A small volume of 5 {mu}L of sample beers containing just an internal standard, used to correct geometry effects, were analyzed without any pre-treatment. The measuring time was 100 s and the detection limits obtained varied from 1{mu}g.L{sup -1} for Mn and Fe to 15{mu}g.L{sup -1} for P. (author)

Analysis of H2O in silicate glass using attenuated total reflectance (ATR) micro-FTIR spectroscopy

Science.gov (United States)

Lowenstern, Jacob B.; Pitcher, Bradley W.

2013-01-01

We present a calibration for attenuated total reflectance (ATR) micro-FTIR for analysis of H2O in hydrous glass. A Ge ATR accessory was used to measure evanescent wave absorption by H2O within hydrous rhyolite and other standards. Absorbance at 3450 cm−1 (representing total H2O or H2Ot) and 1630 cm−1 (molecular H2O or H2Om) showed high correlation with measured H2O in the glasses as determined by transmission FTIR spectroscopy and manometry. For rhyolite, wt%H2O=245(±9)×A3450-0.22(±0.03) and wt%H2Om=235(±11)×A1630-0.20(±0.03) where A3450 and A1630 represent the ATR absorption at the relevant infrared wavelengths. The calibration permits determination of volatiles in singly polished glass samples with spot size down to ~5 μm (for H2O-rich samples) and detection limits of ~0.1 wt% H2O. Basaltic, basaltic andesite and dacitic glasses of known H2O concentrations fall along a density-adjusted calibration, indicating that ATR is relatively insensitive to glass composition, at least for calc-alkaline glasses. The following equation allows quantification of H2O in silicate glasses that range in composition from basalt to rhyolite: wt%H2O=(ω×A3450/ρ)+b where ω = 550 ± 21, b = −0.19 ± 0.03, ρ = density, in g/cm3, and A3450 is the ATR absorbance at 3450 cm−1. The ATR micro-FTIR technique is less sensitive than transmission FTIR, but requires only a singly polished sample for quantitative results, thus minimizing time for sample preparation. Compared with specular reflectance, it is more sensitive and better suited for imaging of H2O variations in heterogeneous samples such as melt inclusions. One drawback is that the technique can damage fragile samples and we therefore recommend mounting of unknowns in epoxy prior to polishing. Our calibration should hold for any Ge ATR crystals with the same incident angle (31°). Use of a different crystal type or geometry would require measurement of several H2O-bearing standards to provide a crystal

Analysis of nutrition-relevant trace elements in human blood and serum by means of total reflection X-ray fluorescence (TXRF) spectroscopy

International Nuclear Information System (INIS)

Stosnach, Hagen; Mages, Margarete

2009-01-01

In clinical service laboratories, one of the most common analytical tasks with regard to inorganic traces is the determination of the nutrition-relevant elements Fe, Cu, Zn, and Se. Because of the high numbers of samples and the commercial character of these analyses, a time-consuming sample preparation must be avoided. In this presentation, the results of total reflection X-ray fluorescence measurements with a low-power system and different sample preparation procedures are compared with those derived from analysis with common methods like Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The results of these investigations indicate that the optimal total reflection X-ray fluorescence analysis of the nutrition-relevant elements Fe, Cu, Zn, and Se can be performed by preparing whole blood and serum samples after dilution with ultrapure water and transferring 10 μl of internally standardized sample to an unsiliconized quartz glass sample carrier with subsequent drying in a laboratory oven. Suitable measurement time was found to be 600 s. The enhanced sample preparation by means of microwave or open digestion, in parts combined with cold plasma ashing, led to an improvement of detection limits by a factor of 2 for serum samples while for whole blood samples an improvement was only observed for samples prepared by means of microwave digestion. As the matrix elements P, S, Cl, and for whole blood Fe have a major influence on the detection limits, most probably a further enhancement of analytical quality requires the removal of the organic matrix. However, for the routine analysis of the nutrition-relevant elements, the dilution preparation was found to be sufficient.

Application of total reflection X-ray fluorescence spectrometry for ...

Indian Academy of Sciences (India)

Applicability of total reflection X-ray fluorescence (TXRF) spectrometry for trace elemental analysis of rainwater samples was studied. The study was used to develop these samples as rainwater standards by the National University of Singapore (NUS). Our laboratory was one of the participants to use TXRF for this study.

Analytical characterization of artists' pigments used in old and modern paintings by total-reflection x-ray fluorescence

International Nuclear Information System (INIS)

Klockenkaemper, R.; Bohlen, A. von; Moens, L.; Devos, W.

1993-01-01

The analytical characterization of artists' pigments is a most helpful tool for art history, conservation and restoration of paintings. A very gentle method of ultra-microsampling was developed that is especially applicable to paintings under restoration. It provides a sample mass of about 1 μg and is virtually non-destructive. This minute amount is sufficient for total-reflection X-ray fluorescence (TXRF) to determine most of those elements building inorganic pigments. The convenient and fast method was applied to oil paintings. Various pigments were identified and their mixing proportion was determined even quantitatively. (author)

Plasticizers in total diet samples, baby food and infant formulae

DEFF Research Database (Denmark)

Petersen, Jens Højslev; Breindahl, T.

2000-01-01

The plasticizers di-n-butylphthalate (DBP), butylbenzylphthalate (BBP), di-2-(ethylhexyl)phthalate (DEHP) and di-2-(ethylhexyl)adipate (DEHA) were analysed in 29 total diet samples, in 11 samples of baby food and in 11 samples of infant formulae. In all of the total diet samples the presence of one...... as in infant formulae. The calculated mean maximum intakes of the individual compounds from the total diet samples were below 10% of the restrictions proposed by the EU Scientific Committee for Food (SCF), and the spread in individual intakes was considerable. DEHP was the plasticizer determined most...

Prediction of purine derivatives, creatinine and total nitrogen concentrations in urine by FT-Near-lnfrared Reflectance spectroscopy (FT-NIR)

International Nuclear Information System (INIS)

Susmel, P.; Piani, B.; Toso, B.; Stefanon, B.

2004-01-01

The objective of this study was to provide an alternative method for the determination of purine derivatives (PD, which include allantoin, uric acid, hypoxanthine and xanthine), creatinine and total nitrogen (N) concentrations in urine. About 180 urine samples from cattle, buffaloes and rabbit were collected and analyzed for PD by HPLC, creatinine by spectrophotometry and N by Kjeldahl method. The urine samples were then analyzed by Fourier Transformed Near Infrared Reflectance Spectroscopy (FT-NIR) to find conformity between this technique and the HPLC and colorimetric methods. FT-NIR can predict allantoin, uric acid, hypoxanthine, xanthine, creatinine, total N and sum of N in both allantoin and uric acid with a satisfactory level of accuracy: the determination coefficient (r 2 ) of validation ranged from 0.888% for uric acid to 0.982% for total N. The coefficients of determination for allantoin, creatinine and sum of N in both allantoin and uric acid were 0.92, 0.894 and 0.90%, respectively. Hypoxanthine and xanthine in urine samples were not detectable by NIRS, probably because of their low concentrations, and therefore they were not considered for instrumental calibration. (author)

Quantitative Analysis of Total Petroleum Hydrocarbons in Soils: Comparison between Reflectance Spectroscopy and Solvent Extraction by 3 Certified Laboratories

Directory of Open Access Journals (Sweden)

Guy Schwartz

2012-01-01

Full Text Available The commonly used analytic method for assessing total petroleum hydrocarbons (TPH in soil, EPA method 418.1, is usually based on extraction with 1,1,2-trichlorotrifluoroethane (Freon 113 and FTIR spectroscopy of the extracted solvent. This method is widely used for initial site investigation, due to the relative low price per sample. It is known that the extraction efficiency varies depending on the extracting solvent and other sample properties. This study’s main goal was to evaluate reflectance spectroscopy as a tool for TPH assessment, as compared with three commercial certified laboratories using traditional methods. Large variations were found between the results of the three commercial laboratories, both internally (average deviation up to 20%, and between laboratories (average deviation up to 103%. Reflectance spectroscopy method was found be as good as the commercial laboratories in terms of accuracy and could be a viable field-screening tool that is rapid, environmental friendly, and cost effective.

Trace elements determination in red and white wines using total-reflection X-ray fluorescence

International Nuclear Information System (INIS)

Anjos, M.J.; Lopes, R.T.; Jesus, E.F.O. de; Moreira, S.; Barroso, R.C.; Castro, C.R.F.

2003-01-01

Several wines produced in different regions from south of Brazil and available in markets in Rio de Janeiro were analyzed for their contents of elements such as: P, S, Cl, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Rb and Sr. Multi-element analysis was possible with simple sample preparation and subsequent analysis by total-reflection X-ray fluorescence using synchrotron radiation. The measurement was carried at the X-ray fluorescence beamline in the Synchrotron Light Source Laboratory in Campinas, Brazil. The levels of the various elements obtained were lower in the Brazilian wines than the values generally found in the literature. The present study indicates the capability of multi-element analysis for determining the contents of various elements present in wines coming from Brazil vineyards by using a simple, sensitive and precise method

Microanalysis of old violin varnishes by total-reflection X-ray fluorescence

Science.gov (United States)

von Bohlen, Alex; Meyer, Friedrich

1997-07-01

Total reflection X-ray fluorescence was used to characterize elements (with Z>13) contained in varnishes applied by prominent violin makers during the last five centuries. Direct analyses of small flakes with masses varnish. Higher amounts of Fe, As and Pb were found in old products, Mn, Co, Cu, Zn and Pb were used in more recent varnishes.

Total and inorganic arsenic in fish samples from Norwegian waters

DEFF Research Database (Denmark)

Julshamn, K.; Nilsen, B. M.; Frantzen, S.

2012-01-01

The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Arctic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast......-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg–1 wet weight. For inorganic arsenic, the concentrations found were very low (...

Abstracts of the 8th Conference on total reflection x-ray fluorescence analysis and related methods

International Nuclear Information System (INIS)

Wobrauschek, P.

2000-01-01

The 8. conference on total reflection x-ray fluorescence analysis and related methods held from 25.9 to 29.9.2000 contains 79 abstracts about x-ray fluorescence analysis (XRFA) as a powerful tool used for industrial production, geological prospecting and for environmental control. Total reflection x-ray fluorescence spectroscopy is also a tool used for chemical analysis in medicine, industry and research. (E.B.)

Total reflection coefficients of low-energy photons presented as universal functions

Directory of Open Access Journals (Sweden)

Ljubenov Vladan

2010-01-01

Full Text Available The possibility of expressing the total particle and energy reflection coefficients of low-energy photons in the form of universal functions valid for different shielding materials is investigated in this paper. The analysis is based on the results of Monte Carlo simulations of photon reflection by using MCNP, FOTELP, and PENELOPE codes. The normal incidence of the narrow monoenergetic photon beam of the unit intensity and of initial energies from 20 keV up to 100 keV is considered, and particle and energy reflection coefficients from the plane homogenous targets of water, aluminum, and iron are determined and compared. The representations of albedo coefficients on the initial photon energy, on the probability of large-angle photon scattering, and on the mean number of photon scatterings are examined. It is found out that only the rescaled albedo coefficients dependent on the mean number of photon scatterings have the form of universal functions and these functions are determined by applying the least square method.

Combining total internal reflection sum frequency spectroscopy spectral imaging and confocal fluorescence microscopy.

Science.gov (United States)

Allgeyer, Edward S; Sterling, Sarah M; Gunewardene, Mudalige S; Hess, Samuel T; Neivandt, David J; Mason, Michael D

2015-01-27

Understanding surface and interfacial lateral organization in material and biological systems is critical in nearly every field of science. The continued development of tools and techniques viable for elucidation of interfacial and surface information is therefore necessary to address new questions and further current investigations. Sum frequency spectroscopy (SFS) is a label-free, nonlinear optical technique with inherent surface specificity that can yield critical organizational information on interfacial species. Unfortunately, SFS provides no spatial information on a surface; small scale heterogeneities that may exist are averaged over the large areas typically probed. Over the past decade, this has begun to be addressed with the advent of SFS microscopy. Here we detail the construction and function of a total internal reflection (TIR) SFS spectral and confocal fluorescence imaging microscope directly amenable to surface investigations. This instrument combines, for the first time, sample scanning TIR-SFS imaging with confocal fluorescence microscopy.

A method for thickness determination of thin films of amalgamable metals by total-reflection X-ray fluorescence

International Nuclear Information System (INIS)

Bennun, L.; Greaves, E.D.; Barros, H.; Diaz-Valdes, J.

2009-01-01

A method for thickness determination of thin amalgamable metallic films by total-reflection X-ray fluorescence (TXRF) is presented. The peak's intensity in TXRF spectra are directly related to the surface density of the sample, i.e. to its thickness in a homogeneous film. Performing a traditional TXRF analysis on a thin film of an amalgamated metal, and determining the relative peak intensity of a specific metal line, the layer thickness can be precisely obtained. In the case of gold thickness determination, mercury and gold peaks overlap, hence we have developed a general data processing scheme to achieve the most precise results.

Generation of neutron standing waves at total reflection of polarized neutrons

International Nuclear Information System (INIS)

Aksenov, V.L.; Nikitenko, Yu.V.; Kozhevnikov, S.V.; Radu, F.; Kruijs, R.; Rekveldt, M.Th.

1999-01-01

The regime of neutron standing waves at reflection of polarized thermal neutrons from the structure glass/Cu (1000 A Angstrom)/Ti (2000 A Angstrom)/Co (60 A Angstrom)/Ti (300 A Angstrom) in a magnetic field directed at an angle to the sample plane is realized. The intensity of neutrons with a particular spin projection on the external magnetic field direction appears to be a periodic function of the neutron wavelength and the glancing angle of the reflected beam. It is shown that the neutron standing wave regime can be a very sensitive method for the determination of changes in the spatial position of magnetic noncollinear layers. (author)

Superradiance or total reflection?

CERN Document Server

László, András

2014-01-01

Numerical evolution of massless scalar fields on Kerr background is studied. The initial data specifications are chosen to have compact support separated from the ergoregion and to yield nearly monochromatic incident wave packets. The initial data is also tuned to maximize the effect of superradiance. Evidences are shown indicating that instead of the anticipated energy extraction from black hole the incident radiation fail to reach the ergoregion rather it suffers a nearly perfect reflection.

Total internal reflection and dynamic light scattering microscopy of gels

Science.gov (United States)

Gregor, Brian F.

Two different techniques which apply optical microscopy in novel ways to the study of biological systems and materials were built and applied to several samples. The first is a system for adapting the well-known technique of dynamic light scattering (DLS) to an optical microscope. This can detect and scatter light from very small volumes, as compared to standard DLS which studies light scattering from volumes 1000x larger. The small scattering volume also allows for the observation of nonergodic dynamics in appropriate samples. Porcine gastric mucin (PGM) forms a gel at low pH which lines the epithelial cell layer and acts as a protective barrier against the acidic stomach environment. The dynamics and microscopic viscosity of PGM at different pH levels is studied using polystyrene microspheres as tracer particles. The microscopic viscosity and microrheological properties of the commercial basement membrane Matrigel are also studied with this instrument. Matrigel is frequently used to culture cells and its properties remain poorly determined. Well-characterized and purely synthetic Matrigel substitutes will need to have the correct rheological and morphological characteristics. The second instrument designed and built is a microscope which uses an interferometry technique to achieve an improvement in resolution 2.5x better in one dimension than the Abbe diffraction limit. The technique is based upon the interference of the evanescent field generated on the surface of a prism by a laser in a total internal reflection geometry. The enhanced resolution is demonstrated with fluorescent samples. Additionally. Raman imaging microscopy is demonstrated using the evanescent field in resonant and non-resonant samples, although attempts at applying the enhanced resolution technique to the Raman images were ultimately unsuccessful. Applications of this instrument include high resolution imaging of cell membranes and macroscopic structures in gels and proteins. Finally, a third

Trace metal determinations by total-reflection x-ray fluorescence analysis in the open Atlantic Ocean

International Nuclear Information System (INIS)

Schmidt, D.; Gerwinski, W.; Radke, I.

1993-01-01

The Intergovernmental Oceanographic Commission (IOC), as a major component of its programme ''Global Investigation of Pollution in the Marine Environment'' (GIPME), maintains a long-standing project on ''Open Ocean Baseline Studies of Trace Contaminants''. Initially, the Atlantic Ocean and trace metals were selected. Four deep-water stations in the Cape Basin, Angola Basin, Cape Verde Abyssal Plain and Seine Abyssal Plain were regularly sampled for at least 36 depths. Additional samples were taken between stations. Samples were distributed to participants and a similar number of additional laboratories. As a central part of our own contribution to the project, we determined the trace heavy metals manganese, nickel, copper, zinc and lead and the lighter selenium by total-reflection X-ray fluorescence analysis. For the TXRF, the pre-enrichment of the trace metals and the separation from the salt matrix were performed by complexation with sodium dibenzyldithiocarbamate and reverse-phase chromatography. Generally, very low levels of trace elements were found in filtered and unfiltered water samples from these remote areas of the open Atlantic Ocean. Typical examples of the distributions of trace metal concentrations on depth profiles from the four deep-water stations as well as intercomparisons between the stations are presented. (author)

Elemental concentration analysis in prostate tissues using total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Leitão, R.G.; Palumbo, A.; Souza, P.A.V.R.; Pereira, G.R.; Canellas, C.G.L.; Anjos, M.J.; Nasciutti, L.E.; Lopes, R.T.

2014-01-01

Prostate cancer (PCa) currently represents the second most prevalent malignant neoplasia in men, representing 21% of all cancer cases. Benign Prostate Hyperplasia (BPH) is an illness prevailing in men above the age of 50, close to 90% after the age of 80. The prostate presents a high zinc concentration, about 10-fold higher than any other body tissue. In this work, samples of human prostate tissues with cancer, BPH and normal tissue were analyzed utilizing total reflection X-ray fluorescence spectroscopy using synchrotron radiation technique (SR-TXRF) to investigate the differences in the elemental concentrations in these tissues. SR-TXRF analyses were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, São Paulo. It was possible to determine the concentrations of the following elements: P, S, K, Ca, Fe, Cu, Zn and Rb. By using Mann–Whitney U test it was observed that almost all elements presented concentrations with significant differences (α=0.05) between the groups studied. - Highlights: ► Prostate cancer is the most frequently diagnosed form of cancer in men. ► Intracellular Zn is correlated with proliferation, differentiation, or apoptosis. ► The prostate gland accumulate high concentration of Zn. ► SR-TXRF is a technique widely used in the analysis of low concentration in samples

Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

KAUST Repository

Wu, Ying

2013-05-06

In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

Total reflection and cloaking by zero index metamaterials loaded with rectangular dielectric defects

KAUST Repository

Wu, Ying; Li, Jichun

2013-01-01

In this work, we investigate wave transmission property through a zero index metamaterial (ZIM) waveguide embedded with rectangular dielectric defects. We show that total reflection and total transmission (cloaking) can be achieved by adjusting the geometric sizes and/or permittivities of the defects. Our work provides another possibility of manipulating wave propagation through ZIM in addition to the widely studied dielectric defects with cylindrical geometries.

Hygrothermal degradation of (3-glycidoxypropyl)trimethoxysilane films studied by neutron and X-ray reflectivity and attenuated total reflection infrared spectroscopy

International Nuclear Information System (INIS)

Tallant, David Robert; Garcia, Manuel Joseph; Majewski, Jaroslaw; Kent, Michael Stuart; Yim, Hyun

2005-01-01

Thin films of organosilanes have great technological importance in the areas of adhesion promotion, durability, and corrosion resistance. However, it is well-known that water can degrade organosilane films, particularly at elevated temperatures. In this work, X-ray and neutron reflectivity (XR and NR) were combined with attenuated total reflection infrared (ATR-IR) spectroscopy to study the chemical and structural changes within thin films of (3-glycidoxypropyl)trimethoxysilane (GPS) after exposure for various periods of time to air saturated with either D 2 O or H 2 O at 80 C. For NR and XR, ultrathin (∼100 (angstrom)) films were prepared by spin-coating. Both D 2 O and H 2 O provide neutron scattering contrast with GPS. Variations in the neutron scattering length density (SLD) profiles (a function of mass density and atomic composition) with conditioning time were measured after drying the samples out and also swelled with H 2 O or D 2 O vapor at room temperature. For samples that were dried out prior to measurement, little or no change was observed for H 2 O conditioning up to 3.5 days, but large changes were observed after 30 days of conditioning. The range of conditioning time for this structural change was narrowed to between 4 and 10 days with XR. The SLD profiles indicated that the top portion of the GPS film was transformed into a thick low-density layer after conditioning, but the bottom portion showed little structural change. A previous NR study of as-prepared GPS films involving swelling with deuterated nitrobenzene showed that the central portion of the film has much lower cross-link density than the region nearest the substrate. The present data show that the central portion also swells to a much greater extent with water and hydrolyzes more rapidly. The chemical degradation mechanism was identified by IR as hydrolysis of siloxane bonds. For ATR-IR, GPS films were prepared by dip-coating, which resulted in a greater and more variable thickness than

Superresolution confocal technology for displacement measurements based on total internal reflection

International Nuclear Information System (INIS)

Kuang Cuifang; Hao Xiang; Wang Tingting; Liu Xu; Ali, M. Yakut

2010-01-01

In order to achieve a higher axial resolution for displacement measurement, a novel method is proposed based on total internal reflection filter and confocal microscope principle. A theoretical analysis of the basic measurement principles is presented. The analysis reveals that the proposed confocal detection scheme is effective in enhancing the resolution of nonlinearity of the reflectance curve greatly. In addition, a simple prototype system has been developed based on the theoretical analysis and a series of experiments have been performed under laboratory conditions to verify the system feasibility, accuracy, and stability. The experimental results demonstrate that the axial resolution in displacement measurements is better than 1 nm in a range of 200 nm which is threefold better than that can be achieved using the plane reflector.

Superresolution confocal technology for displacement measurements based on total internal reflection.

Science.gov (United States)

Kuang, Cuifang; Ali, M Yakut; Hao, Xiang; Wang, Tingting; Liu, Xu

2010-10-01

In order to achieve a higher axial resolution for displacement measurement, a novel method is proposed based on total internal reflection filter and confocal microscope principle. A theoretical analysis of the basic measurement principles is presented. The analysis reveals that the proposed confocal detection scheme is effective in enhancing the resolution of nonlinearity of the reflectance curve greatly. In addition, a simple prototype system has been developed based on the theoretical analysis and a series of experiments have been performed under laboratory conditions to verify the system feasibility, accuracy, and stability. The experimental results demonstrate that the axial resolution in displacement measurements is better than 1 nm in a range of 200 nm which is threefold better than that can be achieved using the plane reflector.

Collection of airborne particulate matter for a subsequent analysis by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Klockenkaemper, R.; Bayer, H.; Bohlen, A. von; Schmeling, M.; Klockow, D.

1995-01-01

The collection of airborne particulate matter by filtration and impaction was adapted to total reflection X-ray fluorescence analysis (TXRF). Cellulose nitrate filters were used for collecting in a Berner impactor. Single filter spots were punched out, placed on quartz-glass carriers, dissolved by tetrahydrofuran and re-precipitated prior to element determinations by TXRF. In a Battelle-type impactor, airborne dust was collected on Plexiglass carriers coated with medical Vaseline. The loaded carriers were directly analyzed by TXRF. In both cases, quantification was simply performed by the addition of an internal standard after sampling. Impactors were made of a suitable material in order to investigate high blank values, collection losses and memory effects. It could be shown that stainless steel, even coated with TiN, is less suitable and should be avoided as an impactor material. Although aluminum is partly recommendable, titanium and the polymer Makrolon are quite appropriate. By using an impactor made of these materials, a reliable multielement determination in airborne dust is made possible with low detection limits as low as 1 ng/m 3 and a satisfactory repeatability of a few %. Short sampling times of only 1 h or less can be realized. The total procedure is simple and time-saving, and can be recommended for routine investigations of airborne particulate matter. (author)

Detection of sibutramine in adulterated dietary supplements using attenuated total reflectance-infrared spectroscopy.

Science.gov (United States)

Deconinck, E; Cauwenbergh, T; Bothy, J L; Custers, D; Courselle, P; De Beer, J O

2014-11-01

Sibutramine is one of the most occurring adulterants encountered in dietary supplements with slimming as indication. These adulterated dietary supplements often contain a herbal matrix. When customs intercept these kind of supplements it is almost impossible to discriminate between the legal products and the adulterated ones, due to misleading packaging. Therefore in most cases these products are confiscated and send to laboratories for analysis. This results inherently in the confiscation of legal, non-adulterated products. Therefore there is a need for easy to use equipment and techniques to perform an initial screening of samples. Attenuated total reflectance-infrared (ATR-IR) spectroscopy was evaluated for the detection of sibutramine in adulterated dietary supplements. Data interpretation was performed using different basic chemometric techniques. It was found that the use of ATR-IR combined with the k-Nearest Neighbours (k-NN) was able to detect all adulterated dietary supplements in an external test set and this with a minimum of false positive results. This means that a small amount of legal products will still be confiscated and analyzed in a laboratory to be found negative, but no adulterated samples will pass the initial ATR-IR screening. Copyright © 2014 Elsevier B.V. All rights reserved.

Energy dispersive X-ray fluorescence analysis with multiple total reflection

International Nuclear Information System (INIS)

Freitag, K.

1985-01-01

The development of a total reflection XRF analyzer and the performance data of this instrument are described. The drastic reduction of the scattered radiation is the outstanding property of the method. Detection limits of elements and matrix effects are discussed. The competition with other methods of analysis has proven its advantages in a wide range. In addition to its multi-element features down to the picogram level, particularly its universal calibration function has turned out to be a great help in the analytical practice. (orig./RB)

Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

International Nuclear Information System (INIS)

Mihucz, Victor G.; Moricz, Agnes M.; Kroepfl, Krisztina; Szikora, Szilvia; Tatar, Eniko; Parra, Lue Meru Marco; Zaray, Gyula

2006-01-01

Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods

Development of off-line layer chromatographic and total reflection X-ray fluorescence spectrometric methods for arsenic speciation

Energy Technology Data Exchange (ETDEWEB)

Mihucz, Victor G. [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); Moricz, Agnes M. [L. Eoetvoes University, Department of Chemical Technology and Environmental Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Kroepfl, Krisztina [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Szikora, Szilvia [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary); Tatar, Eniko [Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary); L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary); Parra, Lue Meru Marco [Universidad Centro-occidental Lisandro Alvarado, Decanato de Agronomia, Departamento de Quimica y Suelos Unidad de Analisis Instrumental, Apartado Postal 4076, Cabudare 3023 (Venezuela); Zaray, Gyula [Joint Research Group of Environmental Chemistry of Hungarian Academy of Sciences and L. Eoetvoes University, P. O. Box 32, H-1518 Budapest (Hungary) and Hungarian Satellite Centre of Trace Elements Institute to UNESCO, P. O. Box 32, H-1518 Budapest (Hungary) and L. Eoetvoes University, Department of Inorganic and Analytical Chemistry, P.O. Box 32, H-1518 Budapest (Hungary)]. E-mail: zaray@ludens.elte.hu

2006-11-15

Rapid and low cost off-line thin layer chromatography-total reflection X-ray fluorescence spectrometry and overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods have been developed for separation of 25 ng of each As(III), As(V), monomethyl arsonic acid and dimethylarsinic acid applying a PEI cellulose stationary phase on plastic sheets and a mixture of acetone/acetic acid/water = 2:1:1 (v/v/v) as eluent system. The type of eluent systems, the amounts (25-1000 ng) of As species applied to PEI cellulose plates, injection volume, development distance, and flow rate (in case of overpressured thin layer chromatography) were taken into consideration for the development of the chromatographic separation. Moreover, a microdigestion method employing nitric acid for the As spots containing PEI cellulose scratched from the developed plates divided into segments was developed for the subsequent total reflection X-ray fluorescence spectrometry analysis. The method was applied for analysis of root extracts of cucumber plants grown in As(III) containing modified Hoagland nutrient solution. Both As(III) and As(V) were detected by applying the proposed thin layer chromatography/overpressured thin layer chromatography-total reflection X-ray fluorescence spectrometry methods.

Total and inorganic arsenic in fish samples from Norwegian waters.

Science.gov (United States)

Julshamn, Kaare; Nilsen, Bente M; Frantzen, Sylvia; Valdersnes, Stig; Maage, Amund; Nedreaas, Kjell; Sloth, Jens J

2012-01-01

The contents of total arsenic and inorganic arsenic were determined in fillet samples of Northeast Artic cod, herring, mackerel, Greenland halibut, tusk, saithe and Atlantic halibut. In total, 923 individual fish samples were analysed. The fish were mostly caught in the open sea off the coast of Norway, from 40 positions. The determination of total arsenic was carried out by inductively coupled plasma mass spectrometry following microwave-assisted wet digestion. The determination of inorganic arsenic was carried out by high-performance liquid chromatography-ICP-MS following microwave-assisted dissolution of the samples. The concentrations found for total arsenic varied greatly between fish species, and ranged from 0.3 to 110 mg kg(-1) wet weight. For inorganic arsenic, the concentrations found were very low (fish used in the recent EFSA opinion on arsenic in food.

Use of thermal neutron reflection method for chemical analysis of bulk samples

International Nuclear Information System (INIS)

Papp, A.; Csikai, J.

2014-01-01

Microscopic, σ β , and macroscopic, Σ β , reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σ β values are additive even for bulk samples in the z=0.5–8 cm interval and so the σ βmol (z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ∼1000 cm 3 dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously. - Highlights: • Check the proposed analytical expression for the description of the flux. • Determination of the reflection cross-sections averaged over bulk samples. • Data rendered to estimate the excess counts for various materials

Use of thermal neutron reflection method for chemical analysis of bulk samples

Energy Technology Data Exchange (ETDEWEB)

Papp, A., E-mail: papppa@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Csikai, J. [Institute of Nuclear Research of the Hungarian Academy of Sciences, (ATOMKI), 4001 Debrecen, Pf. 51 (Hungary); Institute of Experimental Physics, University Debrecen (IEP), 4010 Debrecen-10, Pf. 105 (Hungary)

2014-09-11

Microscopic, σ{sub β}, and macroscopic, Σ{sub β}, reflection cross-sections of thermal neutrons averaged over bulk samples as a function of thickness (z) are given. The σ{sub β} values are additive even for bulk samples in the z=0.5–8 cm interval and so the σ{sub βmol}(z) function could be given for hydrogenous substances, including some illicit drugs, explosives and hiding materials of ∼1000 cm{sup 3} dimensions. The calculated excess counts agree with the measured R(z) values. For the identification of concealed objects and chemical analysis of bulky samples, different neutron methods need to be used simultaneously. - Highlights: • Check the proposed analytical expression for the description of the flux. • Determination of the reflection cross-sections averaged over bulk samples. • Data rendered to estimate the excess counts for various materials.

Characterization of urban air pollution by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Schmeling, Martina

2004-01-01

Besides photochemical smog, particulate air pollution is a constantly growing problem in urban areas. The particulate matter present in pollution events contains often toxic or health impacting elements and is responsible for low visibility, might be triggering respiratory diseases like asthma, and can play an important role in formation or duration of smog events. To characterize particulate pollution in two different cities, samples were taken during intensive field campaigns in Chicago, IL, in 2002 and Phoenix, AZ, in 2001. Both cities experience regularly photochemical smog events as well as particulate pollution, but show very different meteorological and topographical conditions. Therefore it is expected that the particulate composition varies significantly, providing information about different pollution forms. Sampling took place in both cases at elevated locations and had a temporal resolution of 1.5 h and 1 h, respectively. The samples were analyzed by total reflection X-ray fluorescence after digestion of the filter matrix. As expected the elemental composition of particulate matter varied between both cities substantially with Phoenix showing a higher abundance of crustal elements, and Chicago enrichment in anthropogenically produced ones. In both cities diurnal patterns were found, exerting maxima in the morning and minima in the early afternoon. The diurnal pattern was much more regularly and also more strongly pronounced in Phoenix. Phoenix's valley location permits for a more stable nocturnal boundary layer to build up during the night thus trapping particulates efficiently during this time, until mixing occurs in the early morning hours and the residual layer lifts. In Chicago, the diurnal variation was less extreme, but another pattern determines the situation with the lake breeze. The lake breeze corresponds to a shift in wind direction towards the east, i.e. from Lake Michigan during the late morning. It was found that certain elemental species

An optimised set-up for total reflection particle induced X-ray emission

International Nuclear Information System (INIS)

Kan, J.A. van; Vis, R.D.

1997-01-01

MeV proton beams at small angles of incidence (0-35 mrad) are used to analyse trace elements on flat surfaces such as Si wafers or quartz substrates. In these experiments, the particle induced X-ray emission (PIXE) signal is used in a new optimized set-up. This set-up is constructed in such a way that the X-ray detector can reach very large solid angles, larger than 1 sr. Use of these large detector solid angles, combined with the reduction of bremsstrahlung background, affords limits of detection (LOD) of the order of 10 10 at cm -2 using total reflection particle induced X-ray emission (TPIXE). The LODs from earlier TPIXE measurements in a non-optimized set-up are used to estimate LODs in the new TPIXE set-up. Si wafers with low surface concentrations of V, Ni, Cu and Ag are used as standards to calibrate the LODs found with this set-up. The metal concentrations are determined by total reflection X-ray fluorescence (TXRF). The TPIXE measurements are compared with TXRF measurements on the same wafers. (Author)

Smooth and rough Proteus mirabilis lipopolysaccharides studied by total internal reflection ellipsometry

International Nuclear Information System (INIS)

Gleńska-Olender, J.; Dworecki, K.; Sęk, S.; Kwinkowski, M.; Kaca, W.

2013-01-01

Total internal reflection ellipsometry (TIRE), a label-free optical detection technique for studying interactions between biomolecules, was used to examine the adsorption of various forms of lipopolysaccharides (LPSs) isolated from Proteus mirabilis S1959, R110, and R45 strains on a gold surface. The thickness of the adsorbed layers was determined by TIRE, with the average values for S1959, R110, and R45 LPS layers being 78 ± 5, 39 ± 3, and 12 ± 2 nm, respectively. The thickness of LPS layers corresponds to the presence and length of O-specific parts in P. mirabilis LPS molecules. Atomic force microscopy was used as a complementary technique for visualizing lipopolysaccharides on the surface. Force measurements seem to confirm the data obtained from TIRE experiments. - Highlights: • Proteus mirabilis lipopolysaccharides were adsorbed on the gold surface. • Thickness of adsorbed layers was determined by total internal reflection ellipsometry. • Atomic force microscopy was used to visualize lipopolysaccharide build-up on gold surface. • Time is important in the evolution of biomolecular film thickness created on gold surface

Smooth and rough Proteus mirabilis lipopolysaccharides studied by total internal reflection ellipsometry

Energy Technology Data Exchange (ETDEWEB)

Gleńska-Olender, J., E-mail: joannaglenska@wp.pl [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland); Świętokrzyski Biobank, Regional Science and Technology Center, 26-060 Chęciny (Poland); Dworecki, K. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Sęk, S. [Department of Chemistry, University of Warsaw, 02-093 Warsaw (Poland); Kwinkowski, M.; Kaca, W. [Institute of Biology, Jan Kochanowski University, 25-406 Kielce (Poland)

2013-12-02

Total internal reflection ellipsometry (TIRE), a label-free optical detection technique for studying interactions between biomolecules, was used to examine the adsorption of various forms of lipopolysaccharides (LPSs) isolated from Proteus mirabilis S1959, R110, and R45 strains on a gold surface. The thickness of the adsorbed layers was determined by TIRE, with the average values for S1959, R110, and R45 LPS layers being 78 ± 5, 39 ± 3, and 12 ± 2 nm, respectively. The thickness of LPS layers corresponds to the presence and length of O-specific parts in P. mirabilis LPS molecules. Atomic force microscopy was used as a complementary technique for visualizing lipopolysaccharides on the surface. Force measurements seem to confirm the data obtained from TIRE experiments. - Highlights: • Proteus mirabilis lipopolysaccharides were adsorbed on the gold surface. • Thickness of adsorbed layers was determined by total internal reflection ellipsometry. • Atomic force microscopy was used to visualize lipopolysaccharide build-up on gold surface. • Time is important in the evolution of biomolecular film thickness created on gold surface.

Excitations of surface plasmon polaritons by attenuated total reflection, revisited

International Nuclear Information System (INIS)

Barchesi, D.; Otto, A.

2013-01-01

Many textbooks and review papers are devoted to plasmonics based on a selection of the numerous bibliography. But none describes the details of the first culmination of plasmonics in 1968, when surface plasmons become a field of optics. The coupling of light with the surface plasmon leads to the surface plasmon polariton (SPP). Therefore, the authors chose to associate historical insight (not avoiding a personal touch), a modern mathematical formulation of the excitation of the SPP by attenuated total reflection (ATR), considered as well understood since decades, and experimental applications since 1969, including recent developments.

Microplate-compatible total internal reflection fluorescence microscopy for receptor pharmacology

Science.gov (United States)

Chen, Minghan; Zaytseva, Natalya V.; Wu, Qi; Li, Min; Fang, Ye

2013-05-01

We report the use of total internal reflection fluorescence (TIRF) microscopy for analyzing receptor pharmacology and the development of a microplate-compatible TIRF imaging system. Using stably expressed green fluorescence protein tagged β2-adrenergic receptor as the reporter, we found that the activation of different receptors results in distinct kinetic signatures of the TIRF intensity of cells. These TIRF signatures closely resemble the characteristics of their respective label-free dynamic mass redistribution signals in the same cells. This suggests that TIRF in microplate can be used for profiling and screening drugs.

Applications of total reflection X-ray fluorescence in multi-element analysis

International Nuclear Information System (INIS)

Michaelis, W.; Prange, A.; Knoth, J.

1985-01-01

Although Total Reflection X-Ray Fluorescence Analysis (TXRF) became available for practical applications and routine measurements only few years ago, the number of programmes that make use of this method is increasing rapidly. The scope of work is widespread over environmental research and monitoring, mineralogy, mineral exploration, oceanography, biology, medicine and biochemistry. The present paper gives a brief survey of these applications and summarizes some of them which are typical for quite different matrices. (orig.)

Effect of surface plasmon polaritons on the sensitivity of refractive index measurement using total internal reflection method

International Nuclear Information System (INIS)

Roshan Entezar, S.

2015-01-01

The phase difference between two p-polarized and s-polarized plane waves which are reflected under total internal reflection from the base of a prism with a thin metal coating is studied. Typically such a quantity can be used to measure the refractive index of a test material using the total internal reflection method. It is shown that due to the excitation of surface plasmon polaritons at the interface between the tested dielectric material and the thin metal layer, the p-polarized light experiences a large phase shift which enlarges the phase difference between the p-polarized and the s-polarized waves. As a result, the sensitivity of refractive index measurement increases and the error in determining the refractive index decreases. - Highlights: • Phase difference of totally internally reflected p and s polarized beams is studied. • Excitation of the surface wave increases the phase shift of the p-polarized light. • The sensitivity of refractive index measurement increases by using a coated prism. • The error in determining the refractive index decreases using the coated prism

Total reflection X-ray spectroscopy as a rapid analytical method for uranium determination in drainage water

International Nuclear Information System (INIS)

Matsuyama, Tsugufumi; Sakai, Yasuhiro; Izumoto, Yukie; Imaseki, Hitoshi; Hamano, Tsuyoshi; Yoshii, Hiroshi

2017-01-01

Uranium concentrations in drainage water are typically determined by α-spectrometry. However, due to the low specific radioactivity of uranium, the evaporation of large volumes of drainage water, followed by several hours of measurements, is required. Thus, the development of a rapid and simple detection method for uranium in drainage water would enhance the operation efficiency of radiation control workers. We herein propose a novel methodology based on total reflection X-ray fluorescence (TXRF) for the measurement of uranium in contaminated water. TXRF is a particularly desirable method for the rapid and simple evaluation of uranium in contaminated water, as chemical pretreatment of the sample solution is not necessary, measurement times are typically several seconds, and the required sample volume is low. We herein employed sample solutions containing several different concentrations of uranyl acetate with yttrium as an internal standard. The solutions were placed onto sample holders, and were dried prior to TXRF measurements. The relative intensity, otherwise defined as the net intensity ratio of the Lα peak of uranium to the Kα peak of yttrium, was directly proportional to the uranium concentration. Using this method, a TXRF detection limit for uranium in contaminated water of 0.30 μg/g was achieved. (author)

Differences in sampling techniques on total post-mortem tryptase.

Science.gov (United States)

Tse, R; Garland, J; Kesha, K; Elstub, H; Cala, A D; Ahn, Y; Stables, S; Palmiere, C

2017-11-20

The measurement of mast cell tryptase is commonly used to support the diagnosis of anaphylaxis. In the post-mortem setting, the literature recommends sampling from peripheral blood sources (femoral blood) but does not specify the exact sampling technique. Sampling techniques vary between pathologists, and it is unclear whether different sampling techniques have any impact on post-mortem tryptase levels. The aim of this study is to compare the difference in femoral total post-mortem tryptase levels between two sampling techniques. A 6-month retrospective study comparing femoral total post-mortem tryptase levels between (1) aspirating femoral vessels with a needle and syringe prior to evisceration and (2) femoral vein cut down during evisceration. Twenty cases were identified, with three cases excluded from analysis. There was a statistically significant difference (paired t test, p sampling methods. The clinical significance of this finding and what factors may contribute to it are unclear. When requesting post-mortem tryptase, the pathologist should consider documenting the exact blood collection site and method used for collection. In addition, blood samples acquired by different techniques should not be mixed together and should be analyzed separately if possible.

Measurement of conjugated linoleic acid (CLA) in CLA-rich soy oil by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR).

Science.gov (United States)

Kadamne, Jeta V; Jain, Vishal P; Saleh, Mohammed; Proctor, Andrew

2009-11-25

Conjugated linoleic acid (CLA) isomers in oils are currently measured as fatty acid methyl esters by a gas chromatography-flame ionization detector (GC-FID) technique, which requires approximately 2 h to complete the analysis. Hence, we aim to develop a method to rapidly determine CLA isomers in CLA-rich soy oil. Soy oil with 0.38-25.11% total CLA was obtained by photo-isomerization of 96 soy oil samples for 24 h. A sample was withdrawn at 30 min intervals with repeated processing using a second batch of oil. Six replicates of GC-FID fatty acid analysis were conducted for each oil sample. The oil samples were scanned using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and the spectrum was collected. Calibration models were developed using partial least-squares (PLS-1) regression using Unscrambler software. Models were validated using a full cross-validation technique and tested using samples that were not included in the calibration sample set. Measured and predicted total CLA, trans,trans CLA isomers, total mono trans CLA isomers, trans-10,cis-12 CLA, trans-9,cis-11 CLA and cis-10,trans-12 CLA, and cis-9,trans-11 CLA had cross-validated coefficients of determinations (R2v) of 0.97, 0.98, 0.97, 0.98, 0.97, and 0.99 and corresponding root-mean-square error of validation (RMSEV) of 1.14, 0.69, 0.27, 0.07, 0.14, and 0.07% CLA, respectively. The ATR-FTIR technique is a rapid and less expensive method for determining CLA isomers in linoleic acid photo-isomerized soy oil than GC-FID.

Noninvasive method for the assessment of dermal uptake of pesticides using attenuated total reflectance infrared spectroscopy.

Science.gov (United States)

Carden, Angela; Yost, Michael G; Fenske, Richard A

2005-03-01

Dermal absorption of pesticides is a primary exposure route for agricultural workers, but is not well characterized. Current measurement techniques are either invasive, such as tape-stripping, or require extensive sample preparation or analysis time, such as urinary metabolite monitoring or wipe sampling followed by gas chromatography analysis. We present the application of a noninvasive, spectroscopic approach for the measurement of pesticide absorption into skin. Attenuated total reflectance infrared spectroscopy (ATR-IR) was used to monitor directly the absorption of two pesticides--captan and azinphos-methyl--in ten volunteers over 20 min under occlusive conditions. We found substantial variability in absorption across subjects. Our results were comparable to those measured by the more traditional method of wipe-sampling followed by extraction and gas chromatography analysis. Multivariate data analysis, in the form of multivariate curve resolution (MCR), is a novel addition to this type of experiment, yielding time-resolved information unachievable by standard methods. These data are potentially more informative than the monitoring of blood or urinary metabolites because they can be acquired in essentially real-time, allowing observations of pesticide absorption on a rapid timescale rather than over hours or days.

AAS determination of total mercury content in environmental samples

International Nuclear Information System (INIS)

Moskalova, M.; Zemberyova, M.

1997-01-01

Two methods for determination of total mercury content in environmental samples soils, and sediments, were compared. Dissolution procedure of soils, sediments, and biological material under elevated pressure followed by determination of mercury by cold vapour atomic absorption spectrometry using a MHS-1 system and direct total mercury determination without any chemical pretreatment from soil samples using a Trace Mercury Analyzer TMA-254 were compared. TMA-254 was also applied for the determination of mercury in various further standard reference materials. Good agreement with certified values of environmental reference materials was obtained. (authors)

Determination of nitrite, nitrate and total nitrogen in vegetable samples

Directory of Open Access Journals (Sweden)

Manas Kanti Deb

2007-04-01

Full Text Available Yellow diazonium cation formed by reaction of nitrite with 6-amino-1-naphthol-3-sulphonic acid is coupled with β-naphthol in strong alkaline medium to yield a pink coloured azo dye. The azo-dyes shows absorption maximum at 510 nm with molar absorptivity of 2.5 ×104 M-1 cm-1. The dye product obeys Beer's law (correlation coefficient = 0.997, in terms of nitrite concentration, up to 2.7 μg NO2 mL-1. The above colour reaction system has been applied successfully for the determination of nitrite, nitrate and total nitrogen in vegetable samples. Unreduced samples give direct measure for nitrite whilst reduction of samples by copperized-cadmium column gives total nitrogen content and their difference shows nitrate content in the samples. Variety of vegetables have been tested for their N-content (NO2-/NO3-/total-N with % RSD ranging between 1.5 to 2.5 % for nitrite determination. The effects of foreign ions in the determination of the nitrite, nitrate, and total nitrogen have been studied. Statistical comparison of the results with those of reported method shows good agreement and indicates no significant difference in precision.

Biomonitoring of environmental pollution using growth tree rings of Tipuana tipu: Quantification by synchrotron radiation total reflection X-ray fluorescence

Science.gov (United States)

Geraldo, S. M.; Canteras, F. B.; Moreira, S.

2014-02-01

Currently, many studies use the bioindicators to qualitatively and/or quantitatively measure pollution. The analyses of tree growth rings represent one such bioindicator as changes in the environment are often recorded as impressions in the wood. The main objective of the present study is to examine the growth rings of Tipuana tipu - a member of the Leguminosae family that is native to Argentina and Bolivia and was introduced in Brazil as an ornamental plant - for potentially toxic elements. T. tipu is one of the most common trees in the urban landscape of Sao Paulo city and would provide an accurate reflection of environment changes. Tree ring samples previously dated using Synchrotron Radiation Total Reflection X-ray Fluorescence were collected from strategic locations in Sao Paulo. These locations include Piracicaba (SP) that has little access and small flow traffic and the campus of the University of São Paulo. Some trace elements present concentrations higher than considered as normal in some periods. In São Paulo city, samples collected from the campus of University of São Paulo (Butantã), showed the highest toxicity, with concentrations above the tolerable limit for the elements: Cr, Cu, and Pb. For the samples collected in Piracicaba city, one sample presented highest concentrations for the majority of the elements when compared to the other four samples collected at the same place, exceeding the toxicity limits for: Cr, Ni, Cu, and Pb.

Versatile microfluidic total internal reflection (TIR)-based devices: application to microbeads velocity measurement and single molecule detection with upright and inverted microscope.

Science.gov (United States)

Le, Nam Cao Hoai; Yokokawa, Ryuji; Dao, Dzung Viet; Nguyen, Thien Duy; Wells, John C; Sugiyama, Susumu

2009-01-21

A poly(dimethylsiloxane) (PDMS) chip for Total Internal Reflection (TIR)-based imaging and detection has been developed using Si bulk micromachining and PDMS casting. In this paper, we report the applications of the chip on both inverted and upright fluorescent microscopes and confirm that two types of sample delivery platforms, PDMS microchannel and glass microchannel, can be easily integrated depending on the magnification of an objective lens needed to visualize a sample. Although any device configuration can be achievable, here we performed two experiments to demonstrate the versatility of the microfluidic TIR-based devices. The first experiment was velocity measurement of Nile red microbeads with nominal diameter of 500 nm in a pressure-driven flow. The time-sequenced fluorescent images of microbeads, illuminated by an evanescent field, were cross-correlated by a Particle Image Velocimetry (PIV) program to obtain near-wall velocity field of the microbeads at various flow rates from 500 nl/min to 3000 nl/min. We then evaluated the capabilities of the device for Single Molecule Detection (SMD) of fluorescently labeled DNA molecules from 30 bp to 48.5 kbp and confirm that DNA molecules as short as 1105 bp were detectable. Our versatile, integrated device could provide low-cost and fast accessibility to Total Internal Reflection Fluorescent Microscopy (TIRFM) on both conventional upright and inverted microscopes. It could also be a useful component in a Micro-Total Analysis System (micro-TAS) to analyze nanoparticles or biomolecules near-wall transport or motion.

Total Reflection X-ray Fluorescence Analysis (TXRF) using the high flux SAXS camera

CERN Document Server

Wobrauschek, P; Pepponi, G; Bergmann, A; Glatter, O

2002-01-01

Combining the high photon flux from a rotating anode X-ray tube with an X-ray optical component to focus and monochromatize the X-ray beam is the most promising instrumentation for best detection limits in the modern XRF laboratory. This is realized by using the design of a high flux SAXS camera in combination with a 4 kW high brilliant rotating Cu anode X-ray tube with a graded elliptically bent multilayer and including a new designed module for excitation in total reflection geometry within the beam path. The system can be evacuated thus reducing absorption and scattering of air and removing the argon peak in the spectra. Another novelty is the use of a Peltier cooled drift detector with an energy resolution of 148 eV at 5.9 keV and 5 mm sup 2 area. For Co detection limits of about 300 fg determined by a single element standard have been achieved. Testing a real sample NIST 1643d led to detection limits in the range of 300 ng/l for the medium Z.

Metal ions diffusion through polymeric matrices: A total reflection X-ray fluorescence study

International Nuclear Information System (INIS)

Boeykens, S.; Caracciolo, N.; D'Angelo, M.V.; Vazquez, C.

2006-01-01

This work proposes the use of X-ray fluorescence with total reflection geometry to explore the metal ions transport in aqueous hydrophilic polymer solutions. It is centered in the study of polymer concentration influence on ion diffusion. This subject is relevant to various and diverse applications, such as drug controlled release, microbiologic corrosion protection and enhanced oil recovery. It is anticipated that diffusion is influenced by various factors in these systems, including those specific to the diffusing species, such as charge, shape, molecular size, and those related to the structural complexity of the matrix as well as any specific interaction between the diffusing species and the matrix. The diffusion of nitrate salts of Ba and Mn (same charge, different hydrodynamic radii) through water-swollen polymeric solutions and gels in the 0.01% to 1% concentration ranges was investigated. The measurements of the metal concentration were performed by TXRF analysis using the scattered radiation by the sample as internal standard. Results are discussed according to different physical models for solute diffusion in polymeric solutions

Minimal BRDF Sampling for Two-Shot Near-Field Reflectance Acquisition

DEFF Research Database (Denmark)

Xu, Zexiang; Nielsen, Jannik Boll; Yu, Jiyang

2016-01-01

We develop a method to acquire the BRDF of a homogeneous flat sample from only two images, taken by a near-field perspective camera, and lit by a directional light source. Our method uses the MERL BRDF database to determine the optimal set of lightview pairs for data-driven reflectance acquisition...

Forensic Hair Differentiation Using Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Spectroscopy.

Science.gov (United States)

Manheim, Jeremy; Doty, Kyle C; McLaughlin, Gregory; Lednev, Igor K

2016-07-01

Hair and fibers are common forms of trace evidence found at crime scenes. The current methodology of microscopic examination of potential hair evidence is absent of statistical measures of performance, and examiner results for identification can be subjective. Here, attenuated total reflection (ATR) Fourier transform-infrared (FT-IR) spectroscopy was used to analyze synthetic fibers and natural hairs of human, cat, and dog origin. Chemometric analysis was used to differentiate hair spectra from the three different species, and to predict unknown hairs to their proper species class, with a high degree of certainty. A species-specific partial least squares discriminant analysis (PLSDA) model was constructed to discriminate human hair from cat and dog hairs. This model was successful in distinguishing between the three classes and, more importantly, all human samples were correctly predicted as human. An external validation resulted in zero false positive and false negative assignments for the human class. From a forensic perspective, this technique would be complementary to microscopic hair examination, and in no way replace it. As such, this methodology is able to provide a statistical measure of confidence to the identification of a sample of human, cat, and dog hair, which was called for in the 2009 National Academy of Sciences report. More importantly, this approach is non-destructive, rapid, can provide reliable results, and requires no sample preparation, making it of ample importance to the field of forensic science. © The Author(s) 2016.

[Application of Fourier transform attenuated total reflection infrared spectroscopy in analysis of pulp and paper industry].

Science.gov (United States)

Zhang, Yong; Cao, Chun-yu; Feng, Wen-ying; Xu, Ming; Su, Zhen-hua; Liu, Xiao-meng; Lü, Wei-jun

2011-03-01

As one of the most powerful tools to investigate the compositions of raw materials and the property of pulp and paper, infrared spectroscopy has played an important role in pulp and paper industry. However, the traditional transmission infrared spectroscopy has not met the requirements of the producing processes because of its disadvantages of time consuming and sample destruction. New technique would be needed to be found. Fourier transform attenuated total reflection infrared spectroscopy (ATR-FTIR) is an advanced spectroscopic tool for nondestructive evaluation and could rapidly, accurately estimate the production properties of each process in pulp and paper industry. The present review describes the application of ATR-FTIR in analysis of pulp and paper industry. The analysis processes will include: pulping, papermaking, environmental protecting, special processing and paper identifying.

Determination of quality parameters of beers by the use of attenuated total reflectance-Fourier transform infrared spectroscopy.

Science.gov (United States)

Llario, Rafael; Iñón, Fernando A; Garrigues, Salvador; de la Guardia, Miguel

2006-04-15

The estimation of important quality parameters of beers, such as original and real extracts and alcohol content, has been evaluated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) using a partial least square (PLS) calibration approach. Two sample populations, one consisting of 24 samples and other of 21 samples, obtained from the Spanish market and covering different types of beer were used. The first set was used for building and validating the model, whereas the second, measured 6 months after, was used for evaluating its robustness. The spectral range and the size of the calibration set and its suitability for building the PLS model have been evaluated. Considering a calibration set comprised of 12 samples, selected via hierarchical cluster analysis, and a validation data set of 11 samples, the absolute mean difference (d(x-y)) and standard deviation of mean differences (s(x-y)) of the real extract, original extract and alcohol content were 0.009 and 0.069% (w/w), -0.021 and 0.20% (w/w) and -0.003 and 0.130% (v/v), respectively. The maximum error for the prediction of any of these three parameters for a new sample did not exceed 2.5%. These values were practically invariant for both tested data sets. The developed methodology favourably compares with the automatic reference methodology in terms of speed and reagent consumption and waste generation.

TruSeq Stranded mRNA and Total RNA Sample Preparation Kits

Science.gov (United States)

Total RNA-Seq enabled by ribosomal RNA (rRNA) reduction is compatible with formalin-fixed paraffin embedded (FFPE) samples, which contain potentially critical biological information. The family of TruSeq Stranded Total RNA sample preparation kits provides a unique combination of unmatched data quality for both mRNA and whole-transcriptome analyses, robust interrogation of both standard and low-quality samples and workflows compatible with a wide range of study designs.

CO Adsorption and Oxidation at the Catalyst-Water Interface: An Investigation by Attenuated Total Reflection Infrared Spectroscopy.

NARCIS (Netherlands)

Ebbesen, S.D.; Mojet, Barbara; Lefferts, Leonardus

2006-01-01

Adsorption of carbon monoxide and oxidation of preadsorbed carbon monoxide from gas and aqueous phases were studied on a platinum catalyst deposited on a ZnSe internal reflection element (IRE) using attenuated total reflection infrared (ATR-IR) spectroscopy. The results of this study convincingly

Surface characterization of selected polymer thin films by total-reflection x-ray fluorescence spectroscopy and x-ray reflectivity

International Nuclear Information System (INIS)

Innis, Vallerie Ann A.

2006-01-01

Development of available x-ray characterizations tools for grazing incidence techniques was done to be able to probe nano-size thin films. Alignment of a Philips x-ray powder diffractometer was improved to let it perform as an x-ray reflectometer. X-ray reflectometry was coupled with total-reflection x-ray fluorescence spectroscopy. Evaluation of the performance of this grazing incidence techniques was done by preparing polymer thin films of carboxymethylcellulose, carrageenan and polyvinylpyrrolidone (PVP). The thickness of the films were varied by varying the process parameters such as concentration, spin speed and spin time. Angle-dispersive total-reflection x-ray fluorescence spectroscopy profiles of three films showed film formation only in carrageenan and PVP. For both carrageenan and PVP, an increase in concentration yielded a corresponding increase in intensity of the fluorescent or scattered peaks. XRR profiles of carrageenan thin films yielded a mean value for the critical angle close to quartz substrate. Thickness measurements of the prepared carrageenan thin films showed that concentration was the main determinant for final film thickness over the other process parameters. Sulfur fluorescent intensity derived from the TXRF measurement showed a linear relationship with the measured thickness by XRR. For PVP, measured critical angle is lower than quartz. Poor adhesion of the polymer onto the substrate yielded a limited number of thickness measurements made from the XRR profiles. (Author)

Fourier transform infrared-attenuated total reflectance (FTIR-ATR spectroscopy and chemometric techniques for the determination of adulteration in petrodiesel/biodiesel blends

Directory of Open Access Journals (Sweden)

Armando Guerrero Peña

2014-06-01

Full Text Available We propose an analytical method based on fourier transform infrared-attenuated total reflectance (FTIR-ATR spectroscopy to detect the adulteration of petrodiesel and petrodiesel/palm biodiesel blends with African crude palm oil. The infrared spectral fingerprints from the sample analysis were used to perform principal components analysis (PCA and to construct a prediction model using partial least squares (PLS regression. The PCA results separated the samples into three groups, allowing identification of those subjected to adulteration with palm oil. The obtained model shows a good predictive capacity for determining the concentration of palm oil in petrodiesel/biodiesel blends. Advantages of the proposed method include cost-effectiveness and speed; it is also environmentally friendly.

TX 2000: total reflection and 45o energy dispersive x-ray fluorescence spectrometer

International Nuclear Information System (INIS)

Pasti, F.; Torboli, A.; Valdes, M.

2000-01-01

This equipment, developed by Ital Structures, combines two kinds of energy dispersive X-ray fluorescence techniques, the first using total reflection geometry and the second conventional 45 o geometry. The equipment is completely controlled by a PC and to reach the condition of total reflection is very easy because it is enough to load the file with the right position for the corresponding energy. In this apparatus we used an x-ray tube with an alloy anode of Mo/W with a long fine focus at 2200 W. To monochromatize the x-ray beam while choosing, for example, the Mo K alpha or W L alpha or a piece of white spectrum of 33 keV, we use a highly reflective multilayer made of Si/W with 2d = 45.5 A o . The detector used in the equipment is a lithium drifted silicon detector (Si(Li)) with an excellent energy resolution of 135 eV at 5.9 keV and 1000 cps. We developed two programs written in Windows 95, 98 and NT for a 32 bit microprocessor. The first one is called TYACQ32 and has the following functions: first, complete control of the hardware, second automatic alignment of the TX 2000 spectrometer and third acquisition of spectra. The second program is EDXRF32. This is a program to accomplish spectrum and quantitative analysis for TXRF and EDXRF 45 o degrees analysis. (author)

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

Science.gov (United States)

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

2017-04-01

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

Attenuated total internal reflection Fourier transform infrared spectroscopy: a quantitative approach for kidney stone analysis.

Science.gov (United States)

Gulley-Stahl, Heather J; Haas, Jennifer A; Schmidt, Katherine A; Evan, Andrew P; Sommer, André J

2009-07-01

The impact of kidney stone disease is significant worldwide, yet methods for quantifying stone components remain limited. A new approach requiring minimal sample preparation for the quantitative analysis of kidney stone components has been investigated utilizing attenuated total internal reflection Fourier transform infrared spectroscopy (ATR-FT-IR). Calcium oxalate monohydrate (COM) and hydroxylapatite (HAP), two of the most common constituents of urinary stones, were used for quantitative analysis. Calibration curves were constructed using integrated band intensities of four infrared absorptions versus concentration (weight %). The correlation coefficients of the calibration curves range from 0.997 to 0.93. The limits of detection range from 0.07 +/- 0.02% COM/HAP where COM is the analyte and HAP is the matrix, to 0.26 +/- 0.07% HAP/COM where HAP is the analyte and COM is the matrix. This study shows that linear calibration curves can be generated for the quantitative analysis of stone mixtures provided the system is well understood especially with respect to particle size.

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) for Rapid Determination of Microbial Cell Lipid Content: Correlation with Gas Chromatography-Mass Spectrometry (GC-MS).

Science.gov (United States)

Millan-Oropeza, Aaron; Rebois, Rolando; David, Michelle; Moussa, Fathi; Dazzi, Alexandre; Bleton, Jean; Virolle, Marie-Joelle; Deniset-Besseau, Ariane

2017-10-01

There is a growing interest worldwide for the production of renewable oil without mobilizing agriculture lands; fast and reliable methods are needed to identify highly oleaginous microorganisms of potential industrial interest. The aim of this study was to demonstrate the relevance of attenuated total reflection (ATR) spectroscopy to achieve this goal. To do so, the total lipid content of lyophilized samples of five Streptomyces strains with varying lipid content was assessed with two classical quantitative but time-consuming methods, gas chromatography-mass spectrometry (GC-MS) and ATR Fourier transform infrared (ATR FT-IR) spectroscopy in transmission mode with KBr pellets and the fast ATR method, often questioned for its lack of reliability. A linear correlation between these three methods was demonstrated allowing the establishment of equations to convert ATR values expressed as CO/amide I ratio, into micrograms of lipid per milligram of biomass. The ATR method proved to be as reliable and quantitative as the classical GC-MS and FT-IR in transmission mode methods but faster and more reproducible than the latter since it involves far less manipulation for sample preparation than the two others. Attenuated total reflection could be regarded as an efficient fast screening method to identify natural or genetically modified oleaginous microorganisms by the scientific community working in the field of bio-lipids.

Total reflection X-ray Fluorescence determination of interfering elements rubidium and uranium by profile fitting

Science.gov (United States)

Dhara, Sangita; Khooha, Ajay; Singh, Ajit Kumar; Tiwari, M. K.; Misra, N. L.

2018-06-01

Systematic studies to assess the analytical parameters obtained in the total reflection X-ray fluorescence (TXRF) determinations of interfering elements Rb and U using profile fitting are reported in the present manuscript. The X-ray lines Rb Kα and U Lα having serious spectral interference (ΔE = 218 eV), have been used as analytical lines. The intensities of these X-ray lines have been assessed using profile fitting. In order to compare the analytical results of Rb determinations in presence of U, with and without U excitation, synchrotron radiation was tuned to energy just above and below the U Labs edge. This approach shall excite both Rb Kα and U Lα simultaneously and Rb Kα selectively. Finally, the samples were also analyzed with a laboratory based TXRF spectrometer. The analytical results obtained in all these conditions were comparable. The authenticity of the results was assessed by analyzing U with respect to Rb in Rb2U(SO4)3, a standard reference material for U. The average precision obtained for TXRF determinations was below 3% (RSD, n = 3, 1σ) and the percent deviation of TXRF values from the expected values calculated on the basis of sample preparation was within 3%.

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Variable-angle total internal reflection fluorescence microscopy of intact cells of Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Kim Myung K

2011-09-01

Full Text Available Abstract Background Total internal reflection fluorescence microscopy (TIRFM is a powerful tool for observing fluorescently labeled molecules on the plasma membrane surface of animal cells. However, the utility of TIRFM in plant cell studies has been limited by the fact that plants have cell walls, thick peripheral layers surrounding the plasma membrane. Recently, a new technique known as variable-angle epifluorescence microscopy (VAEM was developed to circumvent this problem. However, the lack of a detailed analysis of the optical principles underlying VAEM has limited its applications in plant-cell biology. Results Here, we present theoretical and experimental evidence supporting the use of variable-angle TIRFM in observations of intact plant cells. We show that when total internal reflection occurs at the cell wall/cytosol interface with an appropriate angle of incidence, an evanescent wave field of constant depth is produced inside the cytosol. Results of experimental TIRFM observations of the dynamic behaviors of phototropin 1 (a membrane receptor protein and clathrin light chain (a vesicle coat protein support our theoretical analysis. Conclusions These findings demonstrate that variable-angle TIRFM is appropriate for quantitative live imaging of cells in intact tissues of Arabidopsis thaliana.

Attenuated total reflection design for in situ FT-IR spectroelectrochemical studies

International Nuclear Information System (INIS)

Visser, Hendrik; Curtright, Aimee E.; McCusker, James K.; Sauer, Kenneth

2000-01-01

A versatile spectroelectrochemical apparatus is introduced to study the changes in IR spectra of organic and inorganic compounds upon oxidation or reduction. The design is based on an attenuated total reflection (ATR) device, which permits the study of a wide spectral range of 16,700 cm-1 (600 nm) - 250 cm-1 with a small opaque region of 2250 - 1900 cm-1. In addition, an IR data collection protocol is introduced to deal with electrochemically non-reversible background signals. This method is tested with ferrocene in acetonitrile, producing results that agree with those in the literature

Bistable enhanced total reflection in Kretschmann configuration containing a saturable gain medium.

Science.gov (United States)

Zhou, Haichun; Guo, Jie; Xu, Kun; Li, Zhe; Tang, Junqi; Man, Shiqing

2018-03-05

The reflection of a TM-polarized light beam from a Kretschmann configuration with a saturable gain medium is investigated theoretically. Here, the dielectric constant of the gain medium is described by a classical Lorentzian oscillator model. When surface plasmon polaritons are effectively excited in this structure, it is demonstrated that the curves of enhanced total reflection (ETR) show different shaped hysteresis loops associated with optical bistability owing to gain saturation effect. The effects of the angle of incidence, the thickness of metal film, and the value of small-signal gain on bistable ETR are discussed in detail in a homogeneously broadened (HB) gain medium at line center. Analogous results can also be obtained in an inhomogeneously broadened (inHB) gain medium, while the two switch thresholds and the width of optical bistability hysteresis in an inHB gain medium are significantly different from those in a HB gain medium.

Monitoring of the environmental pollution by trace element analysis in tree-rings using synchrotron radiation total reflection X-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Sirito de Vives, Ana Elisa [School of Civil Engineering, Architecture and Urban Design Methodist University of Piracicaba, Rodovia Santa Barbara D' Oeste/Iracemapolis, km 01, 13450-000 Santa Barbara D' Oeste, SP (Brazil)]. E-mail: aesvives@unimep.br; Moreira, Silvana [State University of Campinas - UNICAMP/FEC (Brazil); Brienza, Sandra Maria Boscolo [School of Civil Engineering, Architecture and Urban Design Methodist University of Piracicaba, Rodovia Santa Barbara D' Oeste/Iracemapolis, km 01, 13450-000 Santa Barbara D' Oeste, SP (Brazil); Silva Medeiros, Jean Gabriel [University of Sao Paulo - USP/ ESALQ (Brazil); Tomazello Filho, Mario Tomazello [University of Sao Paulo - USP/ ESALQ (Brazil); Araujo Domingues Zucchi, Orgheda Luiza [University of Sao Paulo - USP/FCFRP (Brazil); Nascimento Filho, Virgilio Franco do [University of Sao Paulo - USP/CENA (Brazil)

2006-11-15

This paper aims to study the environmental pollution in the tree development, in order to evaluate its use as bioindicator in urban and country sides. The sample collection was carried out in Piracicaba city, Sao Paulo State, which presents high level of environmental contamination in water, soil and air, due to industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. The species Caesalpinia peltophoroides ('Sibipiruna') was selected because it is widely used in urban forestation. Synchrotron Radiation Total Reflection X-ray Fluorescence technique (SR-TXRF) was employed to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was performed in the Brazilian Synchrotron Light Source Laboratory, using a white beam for excitation and a Si(Li) detector for X-ray detection. In several samples, P, K, Ca, Ti, Fe, Sr, Ba and Pb were quantified. The K/Ca, K/P and Pb/Ca ratios were found to decrease towards the bark.

Monitoring of the environmental pollution by trace element analysis in tree-rings using synchrotron radiation total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Sirito de Vives, Ana Elisa; Moreira, Silvana; Brienza, Sandra Maria Boscolo; Silva Medeiros, Jean Gabriel; Tomazello Filho, Mario Tomazello; Araujo Domingues Zucchi, Orgheda Luiza; Nascimento Filho, Virgilio Franco do

2006-01-01

This paper aims to study the environmental pollution in the tree development, in order to evaluate its use as bioindicator in urban and country sides. The sample collection was carried out in Piracicaba city, Sao Paulo State, which presents high level of environmental contamination in water, soil and air, due to industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. The species Caesalpinia peltophoroides ('Sibipiruna') was selected because it is widely used in urban forestation. Synchrotron Radiation Total Reflection X-ray Fluorescence technique (SR-TXRF) was employed to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was performed in the Brazilian Synchrotron Light Source Laboratory, using a white beam for excitation and a Si(Li) detector for X-ray detection. In several samples, P, K, Ca, Ti, Fe, Sr, Ba and Pb were quantified. The K/Ca, K/P and Pb/Ca ratios were found to decrease towards the bark

Censoring: a new approach for detection limits in total-reflection X-ray fluorescence

International Nuclear Information System (INIS)

Pajek, M.; Kubala-Kukus, A.; Braziewicz, J.

2004-01-01

It is shown that the detection limits in the total-reflection X-ray fluorescence (TXRF), which restrict quantification of very low concentrations of trace elements in the samples, can be accounted for using the statistical concept of censoring. We demonstrate that the incomplete TXRF measurements containing the so-called 'nondetects', i.e. the non-measured concentrations falling below the detection limits and represented by the estimated detection limit values, can be viewed as the left random-censored data, which can be further analyzed using the Kaplan-Meier (KM) method correcting for nondetects. Within this approach, which uses the Kaplan-Meier product-limit estimator to obtain the cumulative distribution function corrected for the nondetects, the mean value and median of the detection limit censored concentrations can be estimated in a non-parametric way. The Monte Carlo simulations performed show that the Kaplan-Meier approach yields highly accurate estimates for the mean and median concentrations, being within a few percent with respect to the simulated, uncensored data. This means that the uncertainties of KM estimated mean value and median are limited in fact only by the number of studied samples and not by the applied correction procedure for nondetects itself. On the other hand, it is observed that, in case when the concentration of a given element is not measured in all the samples, simple approaches to estimate a mean concentration value from the data yield erroneous, systematically biased results. The discussed random-left censoring approach was applied to analyze the TXRF detection-limit-censored concentration measurements of trace elements in biomedical samples. We emphasize that the Kaplan-Meier approach allows one to estimate the mean concentrations being substantially below the mean level of detection limits. Consequently, this approach gives a new access to lower the effective detection limits for TXRF method, which is of prime interest for

Total reflection x-ray fluorescence spectrometers for multielemental analysis: status of commercial equipment

International Nuclear Information System (INIS)

Ayala Jimenez, R.E.

2000-01-01

Multi-elemental analysis by total reflection x-ray fluorescence spectrometry has evolved during two decades. At the present there are commercial equipment available for the chemical analysis in all kind of biological and mineral samples. The electronic industry has also been benefited from the scientific and technological developments in the field of TXRF. The basic components of the spectrometers can be summarized as follow: a) excitation source; b) geometric arrangement (optics) for collimation and monochromatization of the primary radiation; c) x-ray detector; d) hardware and software for operation of the instrument, data acquisition and spectral deconvolution to determine the concentrations of the element present in the sample (quantitative analysis). As optional there are manufacturers offering the conventional 45 degrees geometry for direct excitation of bulky liquid or solid samples. Personal communications of the author and the commercial brochures available at the moment of writing this presentation have allowed to list the following type of components used in the TXRF spectrometers for multi-elemental analysis (the devices used in the electronic industry to analyze silicon wafers are excluded). Excitation: high power x-ray tube, output from 1300 to 2000 watts; metal ceramic low power-ray tube, output up to 50 watts. Different anodes are used but molybdenum, tungsten and copper are frequent. The excitation systems can be customized according to the requirements of the laboratory. Detector: Si-Li semi-conductor liquid nitrogen cooled; silicon solid state thermoelectrically cooled (silicon drift detector SDD and Si-PIN diode). Optics: multilayer monochromator of Si-W or Ni-C; double multilayer monochromator. Electronics: spectroscopy amplifier, analog to digital converter adapted to a PC compatible computer with software in Windows environment for the whole operation of the spectrometer and for qualy/quantitative analysis of samples are standards in the

Trajectory method in the theory of Laue diffraction of X rays in crystals: II. Effect of total reflection at bending deformation

International Nuclear Information System (INIS)

Kohn, V. G.

2008-01-01

The effect of total reflection (switching) of a spherical X-ray wave in the case of Laue diffraction in a crystal with bending deformation is analyzed by the trajectory method. Qualitative analytical description and computation of the spatial structure of the reflected beam for large and small distances between the spherical-wave source and the crystal are performed. The mechanism of much more efficient reflection of an X-ray beam by a deformed crystal in comparison with a perfect crystal is clearly demonstrated. It is also shown that the trajectory method is very convenient for description of the total reflection phenomenon.

Trajectory method in the theory of Laue diffraction of X rays in crystals: II. Effect of total reflection at bending deformation

International Nuclear Information System (INIS)

Kohn, V. G.

2008-01-01

The effect of total reflection (switching) of a spherical X-ray wave in the case of Laue diffraction in a crystal with bending deformation is analyzed by the trajectory method. Qualitative analytical description and computation of the spatial structure of the reflected beam for large and small distances between the spherical-wave source and the crystal are performed. The mechanism of much more efficient reflection of an X-ray beam by a deformed crystal in comparison with a perfect crystal is clearly demonstrated. It is also shown that the trajectory method is very convenient for description of the total reflection phenomenon

Parameter study of self-absorption effects in Total Reflection X-ray Fluorescence-X-ray Absorption Near Edge Structure analysis of arsenic

International Nuclear Information System (INIS)

Meirer, F.; Pepponi, G.; Streli, C.; Wobrauschek, P.; Kregsamer, P.; Zoeger, N.; Falkenberg, G.

2008-01-01

Total reflection X-ray Fluorescence (TXRF) analysis in combination with X-ray Absorption Near Edge Structure (XANES) analysis is a powerful method to perform chemical speciation studies at trace element levels. However, when measuring samples with higher concentrations and in particular standards, damping of the oscillations is observed. In this study the influence of self-absorption effects on TXRF-XANES measurements was investigated by comparing measurements with theoretical calculations. As(V) standard solutions were prepared at various concentrations and dried on flat substrates. The measurements showed a correlation between the damping of the oscillations and the As mass deposited. A Monte-Carlo simulation was developed using data of the samples shapes obtained from confocal white light microscopy. The results showed good agreement with the measurements; they confirmed that the key parameters are the density of the investigated atom in the dried residues and the shape of the residue, parameters that combined define the total mass crossed by a certain portion of the incident beam. The study presents a simple approach for an a priori evaluation of the self-absorption in TXRF X-ray absorption studies. The consequences for Extended X-ray Absorption Fine Structure (EXAFS) and XANES measurements under grazing incidence conditions are discussed, leading to the conclusion that the damping of the oscillations seems to make EXAFS of concentrated samples non feasible. For XANES 'fingerprint' analysis samples should be prepared with a deposited mass and sample shape leading to an acceptable absorption for the actual investigation

Method validation to determine total alpha beta emitters in water samples using LSC

International Nuclear Information System (INIS)

Al-Masri, M. S.; Nashawati, A.; Al-akel, B.; Saaid, S.

2006-06-01

In this work a method was validated to determine gross alpha and beta emitters in water samples using liquid scintillation counter. 200 ml of water from each sample were evaporated to 20 ml and 8 ml of them were mixed with 12 ml of the suitable cocktail to be measured by liquid scintillation counter Wallac Winspectral 1414. The lower detection limit by this method (LDL) was 0.33 DPM for total alpha emitters and 1.3 DPM for total beta emitters. and the reproducibility limit was (± 2.32 DPM) and (±1.41 DPM) for total alpha and beta emitters respectively, and the repeatability limit was (±2.19 DPM) and (±1.11 DPM) for total alpha and beta emitters respectively. The method is easy and fast because of the simple preparation steps and the large number of samples that can be measured at the same time. In addition, many real samples and standard samples were analyzed by the method and showed accurate results so it was concluded that the method can be used with various water samples. (author)

Monitoring environmental pollution of trace elements in tree-rings by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

International Nuclear Information System (INIS)

Moreira, Silvana; Vives, Ana Elisa S. de; Brienza, Sandra Maria B.; Medeiros, Jean Gabriel S.; Tomazello Filho, Mario; Zucchi, Orgheda L.A.D.; Nascimento Filho, Virgilio F.

2005-01-01

This paper aims to study the environmental pollution in the tree development, as a manner to evaluate its use as bioindicator in urban and country sides. The sample collecting was carry out in Piracicaba city, Sao Paulo State, that presents high level of environmental contamination of the water, soil and air, due industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. It was selected the Caesalpinia peltophoroides ('Sibipiruna') specie because its very used in urban arborization. It was employed the analytical technique named total reflection X-ray fluorescence (TXRF) to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was done in the Brazilian Synchrotron Light Laboratory, using a white beam for excitation and a Si(Li) detector for characteristic X-ray detection. It was quantified the P, K, Ca, Ti, Fe, Sr, Ba e Pb elements. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-12-15

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

Rapid intra-operative diagnosis of kidney cancer by attenuated total reflection infrared spectroscopy of tissue smears.

Science.gov (United States)

Pucetaite, Milda; Velicka, Martynas; Urboniene, Vidita; Ceponkus, Justinas; Bandzeviciute, Rimante; Jankevicius, Feliksas; Zelvys, Arunas; Sablinskas, Valdas; Steiner, Gerald

2018-01-09

Herein, a technique to analyze air-dried kidney tissue impression smears by means of attenuated total reflection infrared (ATR-IR) spectroscopy is presented. Spectral tumor markers-absorption bands of glycogen-are identified in the ATR-IR spectra of the kidney tissue smear samples. Thin kidney tissue cryo-sections currently used for IR spectroscopic analysis lack such spectral markers as the sample preparation causes irreversible molecular changes in the tissue. In particular, freeze-thaw cycle results in degradation of the glycogen and reduction or complete dissolution of its content. Supervised spectral classification was applied to the recorded spectra of the smears and the test spectra were classified with a high accuracy of 92% for normal tissue and 94% for tumor tissue, respectively. For further development, we propose that combination of the method with optical fiber ATR probes could potentially be used for rapid real-time intra-operative tissue analysis without interfering with either the established protocols of pathological examination or the ordinary workflow of operating surgeon. Such approach could ensure easier transition of the method to clinical applications where it may complement the results of gold standard histopathology examination and aid in more precise resection of kidney tumors. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Apparatus and method for quantitatively evaluating total fissile and total fertile nuclide content in samples

International Nuclear Information System (INIS)

Caldwell, J.T.; Cates, M.R.; Franks, L.A.; Kunz, W.E.

1985-01-01

Simultaneous photon and neutron interrogation of samples for the quantitative determination of total fissile nuclide and total fertile nuclide material present is made possible by the use of an electron accelerator. Prompt and delayed neutrons produced from resulting induced fissions are counted using a single detection system and allow the resolution of the contributions from each interrogating flux leading in turn to the quantitative determination sought. Detection limits for 239 Pu are estimated to be about 3 mg using prompt fission neutrons and about 6 mg using delayed delayed neutrons

Total reflection X-ray fluorescence analysis with synchrotron radiation monochromatized by multilayer structures

International Nuclear Information System (INIS)

Rieder, R.; Wobrauschek, P.; Ladisich, W.; Streli, C.; Aiginger, H.; Garbe, S.; Gaul, G.; Knoechel, A.; Lechtenberg, F.

1995-01-01

To achieve lowest detection limits in total reflection X-ray fluorescence analysis (TXRF) synchrotron radiation has been monochromatized by a multilayer structure to obtain a relative broad energy band compared to Bragg single crystals for an efficient excitation. The energy has been set to 14 keV, 17.5 keV, 31 keV and about 55 keV. Detection limits of 20 fg and 150 fg have been achieved for Sr and Cd, respectively. ((orig.))

Analysis of biological slurry samples by total x-ray fluorescence after in situ microwave digestion

International Nuclear Information System (INIS)

Lue-Meru, M.P.; Capote, T.; Greaves, E.

2000-01-01

Biological slurry samples were analyzed by total reflection x-ray fluorescence (TXRF) after an in situ microwave digestion procedure on the quartz reflector. This method lead to the removal of the matrix by the digestion and permits the enrichment of the analites by using sample amounts higher than those normally used in TXRF for the thin layer requirement since the organic matrix is removed. In consequence, the pre-concentration of sample is performed and the detection capability is increased by a quasi direct method. The samples analyzed were the international IAEA blood standard, the SRM bovine liver 1577-a standard and fresh onion tissues. Slurries were prepared in three ways: a.- weighing a sample amount on the reflector and adding suprapure nitric acid and internal standard followed by microwave digestion, b.-weighing a sample amount and water with an appropriate concentration of the internal standard in an Eppendorf vial, taking then an aliquot to the quartz reflector for microwave digestion with suprapure nitric acid, c.- weighing a sample amount of fresh tissue, homogenising with high speed homegenator to obtain a slurry sample which can be diluted in an ependorf vial with water an the internal standard. Then an aliquot is taken to the reflector for microwave digestion with suprapure nitric acid. Further details of sample preparation procedures will be discussed during presentation. The analysis was carried out in a Canberra spectrometer using the Kalpha lines of the Ag and Mo tubes. The elements Ca, K, Fe, Cu, Zn, Se, Mn, Rb, Br, Sr were determined. The effect of the preparation procedure was evaluated by the accuracy and precision of the results for each element and the percent of recovery. (author)

Total number albedo and average cosine of the polar angle of low-energy photons reflected from water

Directory of Open Access Journals (Sweden)

Marković Srpko

2007-01-01

Full Text Available The total number albedo and average cosine of the polar angle for water and initial photon energy range from 20 keV to 100 keV are presented in this pa per. A water shield in the form of a thick, homogenous plate and per pendicular incidence of the monoenergetic photon beam are assumed. The results were obtained through Monte Carlo simulations of photon reflection by means of the MCNP computer code. Calculated values for the total number albedo were compared with data previously published and good agreement was confirmed. The dependence of the average cosine of the polar angle on energy is studied in detail. It has been found that the total average cosine of the polar angle has values in the narrow interval of 0.66-0.67, approximately corresponding to the reflection angle of 48°, and that it does not depend on the initial photon energy.

Application of CO2 Snow Jet Cleaning in Conjunction with Laboratory Based Total Reflection X-Ray Fluorescence

Science.gov (United States)

Schmeling, M.; Burnett, D. S.; Allton, J. H.; Rodriquez, M.; Tripa, C. E.; Veryovkin, I. V.

2013-01-01

The Genesis mission was the first mission returning solar material to Earth since the Apollo program [1,2]. Unfortunately the return of the space craft on September 8, 2004 resulted in a crash landing, which shattered the samples into small fragments and exposed them to desert soil and other debris. Thus only small fragments of the original collectors are available, each having different degrees of surface contamination. Thorough surface cleaning is required to allow for subsequent analysis of solar wind material embedded within. An initial cleaning procedure was developed in coordination with Johnson Space Center which focused on removing larger sized particulates and a thin film organic contamination acquired during collection in space [3]. However, many of the samples have additional residues and more rigorous and/or innovative cleaning steps might be necessary. These cleaning steps must affect only the surface to avoid leaching and re-distribution of solar wind material from the bulk of the collectors. To aid in development and identification of the most appropriate cleaning procedures each sample has to be thoroughly inspected before and after each cleaning step. Laboratory based total reflection X-ray fluorescence (TXRF) spectrometry lends itself to this task as it is a non-destructive and surface sensitive analytical method permitting analysis of elements from aluminum onward present at and near the surface of a flat substrate [4]. The suitability of TXRF has been demonstrated for several Genesis solar wind samples before and after various cleaning methods including acid treatment, gas cluster ion beam, and CO2 snow jet [5 - 7]. The latter one is non-invasive and did show some promise on one sample [5]. To investigate the feasibility of CO2 snow jet cleaning further, several flown Genesis samples were selected to be characterized before and after CO2 snow application with sample 61052 being discussed below.

Total internal reflection fluorescence (TIRF) microscopy for real-time imaging of nanoparticle-cell plasma membrane interaction

DEFF Research Database (Denmark)

Parhamifar, Ladan; Moghimi, Seyed Moien

2012-01-01

Nanoparticulate systems are widely used for site-specific drug and gene delivery as well as for medical imaging. The mode of nanoparticle-cell interaction may have a significant effect on the pathway of nanoparticle internalization and subsequent intracellular trafficking. Total internal reflection...

Determination of protein concentration in raw milk by mid-infrared fourier transform infrared/attenuated total reflectance spectroscopy.

Science.gov (United States)

Etzion, Y; Linker, R; Cogan, U; Shmulevich, I

2004-09-01

This study investigates the potential use of attenuated total reflectance spectroscopy in the mid-infrared range for determining protein concentration in raw cow milk. The determination of protein concentration is based on the characteristic absorbance of milk proteins, which includes 2 absorbance bands in the 1500 to 1700 cm(-1) range, known as the amide I and amide II bands, and absorbance in the 1060 to 1100 cm(-1) range, which is associated with phosphate groups covalently bound to casein proteins. To minimize the influence of the strong water band (centered around 1640 cm(-1)) that overlaps with the amide I and amide II bands, an optimized automatic procedure for accurate water subtraction was applied. Following water subtraction, the spectra were analyzed by 3 methods, namely simple band integration, partial least squares (PLS) and neural networks. For the neural network models, the spectra were first decomposed by principal component analysis (PCA), and the neural network inputs were the spectra principal components scores. In addition, the concentrations of 2 constituents expected to interact with the protein (i.e., fat and lactose) were also used as inputs. These approaches were tested with 235 spectra of standardized raw milk samples, corresponding to 26 protein concentrations in the 2.47 to 3.90% (weight per volume) range. The simple integration method led to very poor results, whereas PLS resulted in prediction errors of about 0.22% protein. The neural network approach led to prediction errors of 0.20% protein when based on PCA scores only, and 0.08% protein when lactose and fat concentrations were also included in the model. These results indicate the potential usefulness of Fourier transform infrared/attenuated total reflectance spectroscopy for rapid, possibly online, determination of protein concentration in raw milk.

O the Determination of the Complex Refractive Index of Powdered Materials in the 9 TO 11 Micrometer Spectral Region Utilizing AN Attenuated Total Reflectance Technique.

Science.gov (United States)

Gillespie, James Bryce

1982-03-01

A specific method of determining the complex refractive index of powdered materials using attenuated total reflectance (ATR) spectroscopy was investigated. A very precise laser/goniometric ATR system was assembled and applied to powdered samples of carbon blacks, graphite, kaolin clay, quartz, calcite, and sodalime glass beads. The reflectivity data fell into two categories: (1) data representative of a medium having a unique effective refractive index and (2) data representative of a scattering medium having no unique refractive index. Data of the first kind were obtained from all the carbon black, graphite, and kaolin clay samples. The Fahrenfort-Visser solution of the Fresnel equations was applied to the goniometric reflectivity data for these samples to obtain the complex refractive index of these effective media. The complex refractive index obtained in this manner is not that of the bulk material but is instead a value which may be related to the bulk material value through some refractive index mixing rule. A systematic experiment using carbon black of particle size 0.0106 mm diameter was conducted to determine the applicability of several mixture rules for the volume packing fraction range of .2 to .6 which is most often encountered. The Bruggemann effective medium theory produced credible results while the Lorentz-Lorenz rule and the empirical Biot-Arago rule were invalid in this volume packing region. The Bruggemann rule was applied to lampblack, Mogul-L carbon black, graphite, and kaolin clay to obtain the complex refractive indices of these materials from the ATR spectroscopy data. Goniometric reflectivity data representative of an inhomogeneous scattering medium were obtained from all the powdered quartz, powdered calcite, and sodalime glass beads samples. These samples all contained particles with diameters nearly as large as the wavelength. These data demonstrate that the ATR technique, coupled with an effective medium analysis, may be used to obtain

Comparison of Attenuated Total Reflectance Mid-Infrared, Near Infrared, and 1H-Nuclear Magnetic Resonance Spectroscopies for the Determination of Coffee’s Geographical Origin

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Jessica Medina

2017-01-01

Full Text Available The sensorial properties of Colombian coffee are renowned worldwide, which is reflected in its market value. This raises the threat of fraud by adulteration using coffee grains from other countries, thus creating a demand for robust and cost-effective methods for the determination of geographical origin of coffee samples. Spectroscopic techniques such as Nuclear Magnetic Resonance (NMR, near infrared (NIR, and mid-infrared (mIR have arisen as strong candidates for the task. Although a body of work exists that reports on their individual performances, a faithful comparison has not been established yet. We evaluated the performance of 1H-NMR, Attenuated Total Reflectance mIR (ATR-mIR, and NIR applied to fraud detection in Colombian coffee. For each technique, we built classification models for discrimination by species (C. arabica versus C. canephora (or robusta and by origin (Colombia versus other C. arabica using a common set of coffee samples. All techniques successfully discriminated samples by species, as expected. Regarding origin determination, ATR-mIR and 1H-NMR showed comparable capacity to discriminate Colombian coffee samples, while NIR fell short by comparison. In conclusion, ATR-mIR, a less common technique in the field of coffee adulteration and fraud detection, emerges as a strong candidate, faster and with lower cost compared to 1H-NMR and more discriminating compared to NIR.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS.

Science.gov (United States)

Mataveli, Lidiane Raquel Verola; Buzzo, Márcia Liane; de Arauz, Luciana Juncioni; Carvalho, Maria de Fátima Henriques; Arakaki, Edna Emy Kumagai; Matsuzaki, Richard; Tiglea, Paulo

2016-01-01

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled), consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

Directory of Open Access Journals (Sweden)

Lidiane Raquel Verola Mataveli

2016-01-01

Full Text Available This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS. Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD, limit of quantification (LOQ, linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled, consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.

Monitoring environmental pollution of trace elements in tree-rings by synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF)

Energy Technology Data Exchange (ETDEWEB)

Moreira, Silvana [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo]. E-mail: Silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Brienza, Sandra Maria B. [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil) Faculdade de Ciencias Matematicas, da Natureza e de Tecnologia da Informacao]. E-mail: sbrienza@unimep.br; Medeiros, Jean Gabriel S.; Tomazello Filho, Mario [Sao Paulo Univ., Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mail: jeangm@esalq.usp.br; mtomazel@esalq.usp.br; Zucchi, Orgheda L.A.D. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

2005-07-01

This paper aims to study the environmental pollution in the tree development, as a manner to evaluate its use as bioindicator in urban and country sides. The sample collecting was carry out in Piracicaba city, Sao Paulo State, that presents high level of environmental contamination of the water, soil and air, due industrial activities, vehicles combustion, sugar-cane leaves burning in the harvesting, etc. It was selected the Caesalpinia peltophoroides ('Sibipiruna') specie because its very used in urban arborization. It was employed the analytical technique named total reflection X-ray fluorescence (TXRF) to identify and quantify the elements and metals of nutritional and toxicological importance in the wood samples. The analysis was done in the Brazilian Synchrotron Light Laboratory, using a white beam for excitation and a Si(Li) detector for characteristic X-ray detection. It was quantified the P, K, Ca, Ti, Fe, Sr, Ba e Pb elements. (author)

Multielemental analysis in cigarettes using total reflection X-ray fluorescence with synchrotron radiation

International Nuclear Information System (INIS)

Barbosa, R.F.; Anjos, M.J. dos; Jesus, E.F.O. de; Lopes, R.T.; Moreira, S.

2008-01-01

Full text: It is well known that trace elements have important ejects in the life processes. Some of these elements are toxic for the human even at a very low level of intake. It is known that tobacco plant easily absorbs the heavy metals from the soil, especially Cd and Ni, accumulating them in its leaves. Part of these metals are transferred from tobacco to human body where they will be accumulated and damage some organs, mainly kidneys and liver. In this way, cigarettes are responsible for the death of millions of people in the world, about one death every eight seconds. The aim of this work was to determine the elemental concentrations of ten different elements in tobacco of Brazilian cigarettes used Total Reflection X-Ray Fluorescence with Synchrotron Radiation method. The fluorescence measurements were carried out at Brazilian Synchrotron Light Laboratory, Campinas - Sao Paulo. A qualitative analysis of spectral peaks showed that the samples contained potassium, calcium, titanium, chromium, manganese, iron, copper, rubidium and strontium. Among these elements, calcium, potassium and iron presented the highest concentrations. There was a wide range in the elemental concentrations in the tobacco, due various factors, such as agricultural practices, soil characteristics, climatic conditions and plant varieties. Our results are in good concern with the results reported by the scientific literature

On the tunneling of full-vector X-Waves through a slab under frustrated total reflection condition

KAUST Repository

Salem, Mohamed; Bagci, Hakan

2012-01-01

Tunneling of full-vector X-Waves through a dielectric slab under frustrated total reflection condition is investigated. Full-vector X-Waves are obtained by superimposing transverse electric and magnetic polarization components, which are derived from the scalar X-Wave solution. The analysis of reflection and transmission at the dielectric interfaces is carried out analytically in a straightforward fashion using vector Bessel beam expansion. Investigation of the fields propagating away from the farther end of the slab (transmitted fields) shows an advanced (superluminal) transmission of the X-Wave peak. Additionally, a similar advanced reflection is also observed. The apparent tunneling of the peak is shown to be due to the phase shift in the fields' spectra and not to be causally related to the incident peak. © 2012 IEEE.

On the tunneling of full-vector X-Waves through a slab under frustrated total reflection condition

KAUST Repository

Salem, Mohamed

2012-07-01

Tunneling of full-vector X-Waves through a dielectric slab under frustrated total reflection condition is investigated. Full-vector X-Waves are obtained by superimposing transverse electric and magnetic polarization components, which are derived from the scalar X-Wave solution. The analysis of reflection and transmission at the dielectric interfaces is carried out analytically in a straightforward fashion using vector Bessel beam expansion. Investigation of the fields propagating away from the farther end of the slab (transmitted fields) shows an advanced (superluminal) transmission of the X-Wave peak. Additionally, a similar advanced reflection is also observed. The apparent tunneling of the peak is shown to be due to the phase shift in the fields\\' spectra and not to be causally related to the incident peak. © 2012 IEEE.

Terahertz time-domain attenuated total reflection spectroscopy applied to the rapid discrimination of the botanical origin of honeys

Science.gov (United States)

Liu, Wen; Zhang, Yuying; Yang, Si; Han, Donghai

2018-05-01

A new technique to identify the floral resources of honeys is demanded. Terahertz time-domain attenuated total reflection spectroscopy combined with chemometrics methods was applied to discriminate different categorizes (Medlar honey, Vitex honey, and Acacia honey). Principal component analysis (PCA), cluster analysis (CA) and partial least squares-discriminant analysis (PLS-DA) have been used to find information of the botanical origins of honeys. Spectral range also was discussed to increase the precision of PLS-DA model. The accuracy of 88.46% for validation set was obtained, using PLS-DA model in 0.5-1.5 THz. This work indicated terahertz time-domain attenuated total reflection spectroscopy was an available approach to evaluate the quality of honey rapidly.

The conditions for total reflection of low-energy atoms from crystal surfaces

International Nuclear Information System (INIS)

Hou, M.; Robinson, M.T.

1978-01-01

The critical angles for the total reflection of low-energy particles from Cu rows and (001) planes have been investigated, using the binary collision approximation computer simulation code MARLOWE Breakthrough angles were evaluated for H, N, Ne, Ar, Cu, Xe, and Au in the energy range from 0.1 to 7.5 keV. In both the axial and the planar cases, recoiling of the target atoms lowers the energy barrier which the target surface presents to the heavy projectiles. Consequently, the breakthrough angles are reduced for heavy projectiles below the values expected either from observations on light projectiles or from analytical channeling theory. (orig.) [de

Total reflection X-ray fluorescence applied to the chemical elements analysis of the mate tea infusion (Ilex-paraguariensis)

International Nuclear Information System (INIS)

Lopes, Fabio; Appoloni, Carlos R.; Cunha, Richard M. da Silva e; Nascimento Filho, Virgilio Franco do

2002-01-01

The purpose was to evaluate simultaneously the chemical element concentrations from K to Sr (19≤Z≤38) range in six samples of mate tea (Ilex paraguariensis) infusion, commercially available in Paraguay and South of Brazil. The chemical analysis of this beverage has a great nutritional importance for the native people of these areas, due to their large daily consumption. For the determination of these elements the dry-ashing and total reflection X-rays fluorescence (TXRF) were used. The methodology showed limits of detection among 81 ng.mL-1 for K to 10 ng.mL -1 for Zn. Six infusion samples were prepared in triplicate, and the concentration was 3,8 to 10,2 μg.mL -1 for K, Ca and Mn, 0,21 to 1,07 μg. mL -1 for Fe and Zn and 0.03 to 0,17 μg.mL -1 for Ni, Cu, Br, Rb and Sr. The Mn and Ni concentrations are above the maximum permissible values for drinking water established by World Health Organization and Brazilian legislation (these organisms do not regulate the maximum permissible values for chemical elements in mate tea infusion). (author)

Element determination in natural biofilms of mine drainage water by total reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Mages, Margarete; Tuempling, Wolf von Jr.; Veen, Andrea van der; Baborowski, Martina

2006-01-01

Human impacts like mining activities lead to higher element concentration in surface waters. For different pollution levels, the consequences for aquatic organisms are not yet investigated in detail. Therefore, the aim of this investigation is to determine the influence of mining affected surface waters on biofilms. Elements like heavy metals can be absorbed on cell walls and on polymeric substances or enter the cytoplasm of the cells. Thus, they are important for the optimization of industrial biotechnological processes and the environmental biotechnology. Beyond this, biofilms can also play an important role in wastewater treatment processes and serve as bioindicators in the aquatic environment. The presented total reflection X-ray fluorescence spectroscopic investigation was performed to compare the element accumulation behavior of biofilms grown on natural or on artificial materials of drainage water affected by former copper mining activities. A high salt and heavy metal pollution is characteristic for the drainage water. For an assessment of these results, samples from stream Schlenze upstream the confluence with the drainage water, a small tributary of the Saale River in central Germany, were analyzed, too

Total reflection X-ray fluorescence analysis of airborne silver nanoparticles from fabrics.

Science.gov (United States)

Menzel, Magnus; Fittschen, Ursula Elisabeth Adriane

2014-03-18

Ag nanoparticles (NPs) are usually applied to consumer products because of their antimicrobial properties, which are desired in fabrics for sportswear as well as cloth used for cleaning. Hazards to human health from airborne Ag NPs may occur when the NPs are inhaled. NPs are comparable in size to macromolecules and viruses and able to penetrate deep into the lungs, e.g., the alveoli, where they may cause damage to cells and tissue due to their large surface area. In this study, aerosols released form fabrics treated with Ag NPs were collected using a low pressure Berner impactor and analyzed with total reflection X-ray fluorescence (TXRF). We found that the Ag NPs are released primarily in the form of larger particles, mainly 0.13-2 μm, probably attached to fiber material. Using an electron micro probe, single particles could be identified. The detection of backscattered electrons suggests small spots on the particle consist of a heavier element, which most likely is Ag, although the signal in energy-dispersive X-ray spectroscopy (EDX) was below the lower limit of detection (LOD). To achieve LODs necessary for Ag determination, Ar peaks were eliminated by a nitrogen atmosphere provided by the "Picofox-box". This enables linear calibration and quantification of Ag. The LOD was calculated at 0.2 ng (2.0 ppb). Following the TXRF and scanning electron microscopy (SEM)/EDX analysis, the aerosol samples were dissolved in nitric acid and analyzed with ICPMS to successfully confirm the results obtained by the TXRF measurements.

Analysis in crab tissues and in sediment of estuary from Iguape (Sao Paulo, Brazil) by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Salvador, Marcos J.; Sawazaki, David T.A.; Zucchi, Orgheda L.A. Domingues; Vives, Ana Elisa S. de; Hattori, Gustavo Y.

2007-01-01

We report the use of Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF) as a technique for macro, micro and trace elements determination in the tissues of the crab Ulcides cordatus and in the sediments from the Iguape estuary (Sao Paulo, Brazil) for environmental pollution control and toxicological evaluation. The analyses were performed on the U. cordatus (muscles and hepatopancreas) and on sediments from 24 sites of the Iguape estuary (Sao Paulo, Brazil). Tissues and sediments samples were analyzed by SRTXRF after digestion in an open system, using Ga as internal standard. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, and Ba were the elements detected in crab hepatopancreas at concentration ranging from 0.516 (Mn) to 2061 (K) mug/g. Muscles samples presented the elements K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Sr at concentrations ranging from 0.043 (Ni) to 1917 (K) mug/g. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Sn, Ce, and Pb were the elements detected in the sediment samples with concentration between 3.8 (Cu) and 14628 (Fe)mug/g. (author)

Analysis in crab tissues and in sediment of estuary from Iguape (Sao Paulo, Brazil) by total reflection X-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Salvador, Marcos J. [Universidade do Vale do Paraiba (UNIVAP), Sao Jose dos Campos, SP (Brazil)], E-mail: mjsalvador1531@yahoo.com.br; Sawazaki, David T.A.; Zucchi, Orgheda L.A. Domingues [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas], E-mail: david_tatsuo@hotmail.com, E-mail: olzucchi@fcfrp.usp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo], E-mail: aesvives@unimep.br; Hattori, Gustavo Y. [Universidade Federal do Amazonas, Benjamin Constant (Brazil). Faculdade de Ciencias Agrarias], E-mail: hattori@ufam.edu.br

2007-07-01

We report the use of Synchrotron Radiation Total Reflection X-Ray Fluorescence analysis (SR-TXRF) as a technique for macro, micro and trace elements determination in the tissues of the crab Ulcides cordatus and in the sediments from the Iguape estuary (Sao Paulo, Brazil) for environmental pollution control and toxicological evaluation. The analyses were performed on the U. cordatus (muscles and hepatopancreas) and on sediments from 24 sites of the Iguape estuary (Sao Paulo, Brazil). Tissues and sediments samples were analyzed by SRTXRF after digestion in an open system, using Ga as internal standard. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, and Ba were the elements detected in crab hepatopancreas at concentration ranging from 0.516 (Mn) to 2061 (K) mug/g. Muscles samples presented the elements K, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Br and Sr at concentrations ranging from 0.043 (Ni) to 1917 (K) mug/g. Potassium (K), Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Sn, Ce, and Pb were the elements detected in the sediment samples with concentration between 3.8 (Cu) and 14628 (Fe)mug/g. (author)

Association Mapping of Total Carotenoids in Diverse Soybean Genotypes Based on Leaf Extracts and High-Throughput Canopy Spectral Reflectance Measurements.

Directory of Open Access Journals (Sweden)

Arun Prabhu Dhanapal

Full Text Available Carotenoids are organic pigments that are produced predominantly by photosynthetic organisms and provide antioxidant activity to a wide variety of plants, animals, bacteria, and fungi. The carotenoid biosynthetic pathway is highly conserved in plants and occurs mostly in chromoplasts and chloroplasts. Leaf carotenoids play important photoprotective roles and targeted selection for leaf carotenoids may offer avenues to improve abiotic stress tolerance. A collection of 332 soybean [Glycine max (L. Merr.] genotypes was grown in two years and total leaf carotenoid content was determined using three different methods. The first method was based on extraction and spectrophotometric determination of carotenoid content (eCaro in leaf tissue, whereas the other two methods were derived from high-throughput canopy spectral reflectance measurements using wavelet transformed reflectance spectra (tCaro and a spectral reflectance index (iCaro. An association mapping approach was employed using 31,253 single nucleotide polymorphisms (SNPs to identify SNPs associated with total carotenoid content using a mixed linear model based on data from two growing seasons. A total of 28 SNPs showed a significant association with total carotenoid content in at least one of the three approaches. These 28 SNPs likely tagged 14 putative loci for carotenoid content. Six putative loci were identified using eCaro, five loci with tCaro, and nine loci with iCaro. Three of these putative loci were detected by all three carotenoid determination methods. All but four putative loci were located near a known carotenoid-related gene. These results showed that carotenoid markers can be identified in soybean using extract-based as well as by high-throughput canopy spectral reflectance-based approaches, demonstrating the utility of field-based canopy spectral reflectance phenotypes for association mapping.

Library search with regular reflectance IR spectra

International Nuclear Information System (INIS)

Staat, H.; Korte, E.H.; Lampen, P.

1989-01-01

Characterisation in situ for coatings and other surface layers is generally favourable, but a prerequisite for precious items such as art objects. In infrared spectroscopy only reflection techniques are applicable here. However for attenuated total reflection (ATR) it is difficult to obtain the necessary optical contact of the crystal with the sample, when the latter is not perfectly plane or flexible. The measurement of diffuse reflectance demands a scattering sample and usually the reflectance is very poor. Therefore in most cases one is left with regular reflectance. Such spectra consist of dispersion-like feature instead of bands impeding their interpretation in the way the analyst is used to. Furthermore for computer search in common spectral libraries compiled from transmittance or absorbance spectra a transformation of the reflectance spectra is needed. The correct conversion is based on the Kramers-Kronig transformation. This somewhat time - consuming procedure can be speeded up by using appropriate approximations. A coarser conversion may be obtained from the first derivative of the reflectance spectrum which resembles the second derivative of a transmittance spectrum. The resulting distorted spectra can still be used successfully for the search in peak table libraries. Experiences with both transformations are presented. (author)

Observation of neutron standing waves at total reflection by precision gamma spectroscopy

International Nuclear Information System (INIS)

Aksenov, V.L.; Gundorin, N.A.; Nikitenko, Yu.V.; Popov, Yu.P.; Cser, L.

1998-01-01

Total reflection of polarized neutrons from the layered structure glass/Fe (1000 A Angstrom)/Gd (50 A Angstrom) is investigated by registering neutrons and gamma-quanta from thermal neutron capture. The polarization ratio of gamma counts of neutron beams polarized in and opposite the direction of the magnetic field is measured. The polarization ratio is larger than unity for the neutron wavelengths λ 2.2 A Angstrom. Such behaviour of the wavelength dependence of the gamma-quanta polarization ratio points to the fact that over the surface of the Fe Layer a neutron standing wave caused by the interference of the incident neutron wave and the wave refracted from the magnetized Fe layer is formed

Synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) for evaluation of food contamination

International Nuclear Information System (INIS)

Vives, A.E.S.; Brienza, S.M.B.; Moreira, S.; Zucchi, O.L.A.; Nascimento Filho, V.F.

2006-01-01

The objective of this study was to use synchrotron radiation total reflection X-ray fluorescence analysis (SR-TXRF) for the determination of metals and other elements in food available to the population in commercial establishments, in order to evaluate the risks of contamination by these products. The analyzed species were vegetables, leafy vegetables, fruits, cereal and grain. The results indicated that some species were contaminated by Cr, Cu, Zn and Pb with concentrations much higher than the reference values. (author)

Nonpolarizing beam splitter designed by frustrated total internal reflection inside a glass cube.

Science.gov (United States)

Xu, Xueke; Shao, Jianda; Fan, Zhengxiu

2006-06-20

A method for the design of an all-dielectric nonpolarizing prism beam splitter utilizing the principle of frustrated total internal reflection is reported. The nonpolarizing condition for a prism beam splitter is discussed, and some single layer design examples are elaborated. The concept can be applied to a wide range of wavelengths and arbitrary transmittance values, and with the help of a computer design program examples of 400-700 nm, T(p)=T(s)=0.5+/-0.01, with incident angles of 45 degrees and 62 degrees are given. In addition, the sensitivity and application of the design are also discussed.

Secondary cell wall development in cotton fibers as examined with attenuated total reflection Fourier transform infrared spectroscopy

Science.gov (United States)

Cotton fibers harvested at 18, 20, 24, 28, 32, 36 and 40 days after flowering were examined using attenuated total reflection Fourier transform-infrared (ATR FT-IR) spectroscopy. The selected harvesting points coincide with secondary cell wall (SCW) development in the fibers. Progressive but moderat...

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

Science.gov (United States)

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

2016-02-01

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

Potential and limitation of mid-infrared attenuated total reflectance spectroscopy for real time analysis of raw milk in milking lines.

Science.gov (United States)

Linker, Raphael; Etzion, Yael

2009-02-01

Real-time information about milk composition would be very useful for managing the milking process. Mid-infrared spectroscopy, which relies on fundamental modes of molecular vibrations, is routinely used for off-line analysis of milk and the purpose of the present study was to investigate the potential of attenuated total reflectance mid-infrared spectroscopy for real-time analysis of milk in milking lines. The study was conducted with 189 samples from over 70 cows that were collected during an 18 months period. Principal component analysis, wavelets and neural networks were used to develop various models for predicting protein and fat concentration. Although reasonable protein models were obtained for some seasonal sub-datasets (determination errors protein), the models lacked robustness and it was not possible to develop a model suitable for all the data. Determination of fat concentration proved even more problematic and the determination errors remained unacceptably large regardless of the sub-dataset analyzed or of the spectral intervals used. These poor results can be explained by the limited penetration depth of the mid-infrared radiation that causes the spectra to be very sensitive to the presence of fat globules or fat biofilms in the boundary layer that forms at the interface between the milk and the crystal that serves both as radiation waveguide and sensing element. Since manipulations such as homogenisation are not permissible for in-line analysis, these results show that the potential of mid-infrared attenuated total reflectance spectroscopy for in-line milk analysis is indeed quite limited.

The analysis of Th in the Korean total diet sample by RNAA

International Nuclear Information System (INIS)

Chung, Yong Sam; Moon, Jong Hwa; Kang, Sang Hoon; Park, Kwang Won

1999-01-01

In order to estimate the degree of intake of 232 Th through daily diet, a korean total diet sample was collected and made after the investigation of the amount of consumption of daily diet which is dependent on the ages of 20's to 50's. For Th analysis, the RNAA method was applied and NIST SRM 1575, Pine Needle was used as quality control materials. The result of the SRM analysis was compared with a certified value. The relative error was 5%. The determination of the Th in the korean total diet sample was carried out under the same analytical condition and procedure with SRM. As a result of the korean total diet sample, the concentration of Th was in 3.4 ± 0.2 ppb and the amount of daily intake of Th by the diet is found to be 0.67 g per day. Radioactivity by Th intake was estimated to be about 2.7 mBq per person per day and annual dose equivalent was revealed as 0.73 μSv per person

Transmission and total reflection of subhertz electromagnetic waves at the earth-atmosphere interface

International Nuclear Information System (INIS)

Shiozawa, Toshiyuki

2010-01-01

For the purpose of providing for a theoretical background for the study of electromagnetic fields generated by precursory effects of earthquakes, the problem of transmission and total reflection at the earth-atmosphere interface is investigated in detail for a subhertz plane electromagnetic wave incident from the earth's crust. The term ''subhertz'' means 'below 1 Hz'. First, for the special case of normal incidence, the overall power transmission coefficient at the earth-atmosphere interface is found to take a maximum value at a definite frequency f 0 which is inversely proportional to the square of the depth of a virtual hypocenter. A typical value of f 0 falls around 0.01 Hz. For oblique incidence as well, this feature of the overall power transmission coefficient is retained except in the vicinity of the critical angle of incidence for the H-wave. At the critical angle of incidence, the power flow carried by a surface wave along the interface becomes anomalously large for the H-wave. However, over a wide range of angles of incidence greater than the critical angle, the power flow carried by the E-wave exceeds that carried by the H-wave by orders of magnitude. Finally, the energy conservation relations for the incident, reflected, and transmitted waves at the earth-atmosphere interface are discussed. For an incident wave coming from the earth's crust, the interactive power between the incident and reflected waves plays a crucial role for the conservation of energy at the interface.

Direct determination of lycopene content in tomatoes (Lycopersicon esculentum) by attenuated total reflectance infrared spectroscopy and multivariate analysis.

Science.gov (United States)

Halim, Yuwana; Schwartz, Steven J; Francis, David; Baldauf, Nathan A; Rodriguez-Saona, Luis E

2006-01-01

Lycopene is a potent antioxidant that has been shown to play critical roles in disease prevention. Efficient assays for detection and quantification of lycopene are desirable as alternatives to time- and labor-intensive methods. Attenuated total reflectance infrared (ATR-IR) spectroscopy was used for quantification of lycopene in tomato varieties. Calibration models were developed by partial least-squares regression (PLSR) using quantitative measures of lycopene concentration from liquid chromatography as reference method. IR spectra showed a distinct marker band at 957 cm(-1) for trans Carbon-Hydrogen (CH) deformation vibration of lycopene. PLSR models predicted the lycopene content accurately and reproducibly with a correlation coefficient (sigma) of 0.96 and standard error of cross-validation ATR-IR spectroscopy allowed for rapid, simple, and accurate determination of lycopene in tomatoes with minimal sample preparation. Results suggest that the ATR-IR method is applicable for high-throughput quantitative analysis and screening for lycopene in tomatoes.

Optical interrupter based in the internal total reflection of spatial solitons at nonlinear saturable interfaces; Interruptores opticos basados en reflexion interna total de solitones espaciales en interfaces no lineales saturables

Energy Technology Data Exchange (ETDEWEB)

Alvarado-Mendez, E.; Torres-Cisneros, M.; Gutierrez-Hernandez, D. A.; Andrade-Lucio, J. A.; Rojas-Lagunas, R.; Pedraza-Ortega, J. C.; Torres Cisneros, G. E. [Universidad de Guanajuato, Guanajuato (Mexico); Sanchez Mondragon, J. J. [Universidad Autonoma del Estado de Morelos, Morelos (Mexico); Flores-Alvarado, G. [Preparatoria por Cooperacion Domingo Arenas, Tlaxcala (Mexico)

2001-06-01

We study the reflection of one-dimensional spatial soliton at the nonlinear interface between a saturable type medium and linear medium. Our study makes emphasis on determining the physical conditions under which the beam reflected by the interface is still a spatial soliton. Depended the incidence angle we find three critical regions for spatial solitons in the interface. We observed nonlinear Goos- Haechen shift is determined if reflection angle are conserved. Finally, we present preliminary experimental results in SBN61:Ce of the total internal reflection of one dimensional beam. [Spanish] Estudiamos la reflexion de un soliton espacial unidimensional en una interfase formada por un medio no lineal saturable y un medio lineal. Nuestros estudios hacen enfasis en determinar las condiciones fisicas bajo las cuales el haz reflejado por la interfase no lineal sigue siendo soliton. Encontramos tres regiones criticas para un soliton especial en la interfase, dependiendo del valor que tome el angulo de incidencia. Asi mismo observamos corrimiento Goos-Haechen no lineal que es determinante para la conservacion del angulo de reflexion. Finalmente, presentamos resultados preliminares experimentales en SBN61:Ce de la reflexion interna total de un haz unidimensional.

Application of multibounce attenuated total reflectance fourier transform infrared spectroscopy and chemometrics for determination of aspartame in soft drinks.

Science.gov (United States)

Khurana, Harpreet Kaur; Cho, Il Kyu; Shim, Jae Yong; Li, Qing X; Jun, Soojin

2008-02-13

Aspartame is a low-calorie sweetener commonly used in soft drinks; however, the maximum usage dose is limited by the U.S. Food and Drug Administration. Fourier transform infrared (FTIR) spectroscopy with attenuated total reflectance sampling accessory and partial least-squares regression (PLS) was used for rapid determination of aspartame in soft drinks. On the basis of spectral characterization, the highest R2 value, and lowest PRESS value, the spectral region between 1600 and 1900 cm(-1) was selected for quantitative estimation of aspartame. The potential of FTIR spectroscopy for aspartame quantification was examined and validated by the conventional HPLC method. Using the FTIR method, aspartame contents in four selected carbonated diet soft drinks were found to average from 0.43 to 0.50 mg/mL with prediction errors ranging from 2.4 to 5.7% when compared with HPLC measurements. The developed method also showed a high degree of accuracy because real samples were used for calibration, thus minimizing potential interference errors. The FTIR method developed can be suitably used for routine quality control analysis of aspartame in the beverage-manufacturing sector.

Comparative study of radiometric and calorimetric methods for total hemispherical emissivity measurements

Science.gov (United States)

Monchau, Jean-Pierre; Hameury, Jacques; Ausset, Patrick; Hay, Bruno; Ibos, Laurent; Candau, Yves

2018-05-01

Accurate knowledge of infrared emissivity is important in applications such as surface temperature measurements by infrared thermography or thermal balance for building walls. A comparison of total hemispherical emissivity measurement was performed by two laboratories: the Laboratoire National de Métrologie et d'Essais (LNE) and the Centre d'Études et de Recherche en Thermique, Environnement et Systèmes (CERTES). Both laboratories performed emissivity measurements on four samples, chosen to cover a large range of emissivity values and angular reflectance behaviors. The samples were polished aluminum (highly specular, low emissivity), bulk PVC (slightly specular, high emissivity), sandblasted aluminum (diffuse surface, medium emissivity), and aluminum paint (slightly specular surface, medium emissivity). Results obtained using five measurement techniques were compared. LNE used a calorimetric method for direct total hemispherical emissivity measurement [1], an absolute reflectometric measurement method [2], and a relative reflectometric measurement method. CERTES used two total hemispherical directional reflectometric measurement methods [3, 4]. For indirect techniques by reflectance measurements, the total hemispherical emissivity values were calculated from directional hemispherical reflectance measurement results using spectral integration when required and directional to hemispherical extrapolation. Results were compared, taking into account measurement uncertainties; an added uncertainty was introduced to account for heterogeneity over the surfaces of the samples and between samples. All techniques gave large relative uncertainties for a low emissive and very specular material (polished aluminum), and results were quite scattered. All the indirect techniques by reflectance measurement gave results within ±0.01 for a high emissivity material. A commercial aluminum paint appears to be a good candidate for producing samples with medium level of emissivity

Single-Molecule Fluorescence Studies of Membrane Transporters Using Total Internal Reflection Microscopy.

Science.gov (United States)

Goudsmits, Joris M H; van Oijen, Antoine M; Slotboom, Dirk J

2017-01-01

Cells are delineated by a lipid bilayer that physically separates the inside from the outer environment. Most polar, charged, or large molecules require proteins to reduce the energetic barrier for passage across the membrane and to achieve transport rates that are relevant for life. Here, we describe techniques to visualize the functioning of membrane transport proteins with fluorescent probes at the single-molecule level. First, we explain how to produce membrane-reconstituted transporters with fluorescent labels. Next, we detail the construction of a microfluidic flow cell to image immobilized proteoliposomes on a total internal reflection fluorescence microscope. We conclude by describing the methods that are needed to analyze fluorescence movies and obtain useful single-molecule data. © 2017 Elsevier Inc. All rights reserved.

Reflection and Non-Reflection of Particle Wavepackets

Science.gov (United States)

Cox, Timothy; Lekner, John

2008-01-01

Exact closed-form solutions of the time-dependent Schrodinger equation are obtained, describing the propagation of wavepackets in the neighbourhood of a potential. Examples given include zero reflection, total reflection and partial reflection of the wavepacket, for the sech[superscript 2]x/a, 1/x[superscript 2] and delta(x) potentials,…

Total Decomposition of Environmental Radionuclide Samples with a Microwave Oven

International Nuclear Information System (INIS)

Ramon Garcia, Bernd Kahn

1998-01-01

Closed-vessel microwave assisted acid decomposition was investigated as an alternative to traditional methods of sample dissolution/decomposition. This technique, used in analytical chemistry, has some potential advantages over other procedures. It requires less reagents, it is faster, and it has the potential of achieving total dissolution because of higher temperatures and pressures

Single cell adhesion strength assessed with variable-angle total internal reflection fluorescence microscopy

Directory of Open Access Journals (Sweden)

Marcelina Cardoso Dos Santos

2017-06-01

Full Text Available We propose a new strategy to evaluate adhesion strength at the single cell level. This approach involves variable-angle total internal reflection fluorescence microscopy to monitor in real time the topography of cell membranes, i.e. a map of the membrane/substrate separation distance. According to the Boltzmann distribution, both potential energy profile and dissociation energy related to the interactions between the cell membrane and the substrate were determined from the membrane topography. We have highlighted on glass substrates coated with poly-L-lysine and fibronectin, that the dissociation energy is a reliable parameter to quantify the adhesion strength of MDA-MB-231 motile cells.

Determination of heavy metals in Damascus drinking water using total reflection x-ray fluorescence

International Nuclear Information System (INIS)

Bakraji, E. H.; Karajo, J.

2000-01-01

Total reflection x-ray fluorescence spectrometry and chemical preconcentration have applied for multi-elemental analysis of Damascus drinking water. Water was taken directly from taps of several city sectors and analyzed for the following trace elements: Ti, V, Cr, Fe, Co, Ni, Cu, Zn, Se and Pb. The detection limits were found to be in the range of 0.1 to 0.4 μg/l. The mean levels of trace elements in the Damascus drinking water were below the World Health Organization drinking water quality guidelines. (author)

Synchrotron total reflection X-ray fluorescence at BL-16 microfocus beamline of Indus-2

Energy Technology Data Exchange (ETDEWEB)

Tiwari, M. K., E-mail: mktiwari@rrcat.gov.in; Singh, A. K., E-mail: mktiwari@rrcat.gov.in; Das, Gangadhar, E-mail: mktiwari@rrcat.gov.in; Chowdhury, Anupam, E-mail: mktiwari@rrcat.gov.in; Lodha, G. S., E-mail: mktiwari@rrcat.gov.in [Indus Synchrotrons Utilisation Division, Raja Ramanna Centre for Advanced Technology, Indore-452013 (India)

2014-04-24

Determination of ultra trace elements is important in many disciplines both in basic and applied sciences. Numerous applications show their importance in medical science, environmental science, materials science, food processing and semiconductor industries and in maintaining the quality control of ultra pure chemicals and reagents. We report commissioning of a synchrotron based total reflection x-ray fluorescence (TXRF) facility on the BL-16 microfocus beamline of Indus-2. This paper describes the performance of the BL-16 TXRF spectrometer and the detailed description of its capabilities through examples of measured results.

Open focused microwave-assisted sample preparation for rapid total and mercury species determination in environmental solid samples

OpenAIRE

Tseng, C. M.; Garraud, H.; Amouroux, D.; Donard, O. F. X.; de Diego, A.

1998-01-01

This paper describes rapid, simple microwave-assisted leaching/ digestion procedures for total and mercury species determination in sediment samples and biomaterials. An open focused microwave system allowed the sample preparation time to be dramatically reduced to only 24 min when a power of 40-80 W was applied. Quantitative leaching of methylmercury from sediments by HNO3 solution and complete dissolution of biomaterials by an alkaline solution, such as 25% TMAH solution, were obtained. Met...

Exploiting total internal reflection geometry for efficient optical modulation of terahertz light

Directory of Open Access Journals (Sweden)

Xudong Liu

2016-10-01

Full Text Available Efficient methods to modulate terahertz (THz light are essential for realizing rapid THz imaging and communication applications. Here we report a novel THz modulator which utilizes the evanescent wave in a total internal reflection setup coupled with a conductive interface to enhance the attenuation efficiency of THz light. This approach makes it possible to achieve close to 100% modulation with a small interface conductivity of 12 mS. The frequency dependence of this technique is linked to the optical properties of the materials: a material with close to frequency independent conductivity that is also controllable will result in an achromatic modulation response, and the device performance can be optimized further by tuning the internal reflection angle. In this work, we focus on applying the technique in the terahertz frequency range. Using an LED array with a pump intensity of 475 mW/cm2 to produce carriers in a silicon wafer, we have achieved a modulation depth of up to 99.9% in a broad frequency range of 0.1 THz–0.8 THz. The required pumping power for the generation of the required free carriers is low because the sheet conductivity needed is far less than required for traditional transmission techniques. Consequently, the device can be modulated by an LED making it a very practical, low cost, and scalable solution for THz modulation.

On revealing the vertical structure of nanoparticle films with elemental resolution: A total external reflection X-ray standing waves study

Energy Technology Data Exchange (ETDEWEB)

Zargham, Ardalan, E-mail: zargham@ifp.uni-bremen.d [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Schmidt, Thomas; Flege, Jan Ingo; Sauerbrey, Marc; Hildebrand, Radowan [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany); Roehe, Sarah; Baeumer, Marcus [Applied and Physical Chemistry, University of Bremen, Leobener Str. 2, 28359, Bremen (Germany); Falta, Jens [Institute of Solid State Physics, University of Bremen, Otto-Hahn-Allee 1, 28359 Bremen (Germany)

2010-02-15

We present a promising combination of methods to precisely determine the morphology of nanostructures, drawing on the example of monodisperse CoPt{sub 3} nanoparticle films deposited by spin coating and dip coating techniques on functionalized Au substrates. Ex-situ X-ray standing waves in total external reflection combined with X-ray reflectivity measurements were employed to determine element-specific atomic-density distributions in vertical direction.

Recent trends in total reflection X-ray fluorescence spectrometry for biological applications

International Nuclear Information System (INIS)

Szoboszlai, Norbert; Polgari, Zsofia; Mihucz, Victor G.; Zaray, Gyula

2009-01-01

This review is focused on the application of total reflection X-ray fluorescence (TXRF) spectrometry in the field of biological research. In the last decade, most papers were published by authors who applied laboratory-scale TXRF equipments. The application of synchrotron radiation as excitation source (SR-TXRF) shows a slowly increasing tendency. In the cited papers the micro-, trace and multielement capability of these TXRF techniques was demonstrated in the clinical and medical laboratory practice, as well as in various plant physiological studies. For speciation of elements in biological matrices, the TXRF was used as element specific detector following an off-line separation step (e.g., thin layer chromatography, high performance liquid chromatography), however, these off-line methods are not competitive with the on-line coupled HPLC-inductively coupled plasma mass spectrometry

Thin film characterization by total reflection x-ray fluorescence

International Nuclear Information System (INIS)

Danel, Adrien; Nolot, Emmanuel; Veillerot, Marc; Olivier, Segolene; Decorps, Tifenn; Calvo-Munoz, Maria-Luisa; Hartmann, Jean-Michel; Lhostis, Sandrine; Kohno, Hiroshi; Yamagami, Motoyuki; Geoffroy, Charles

2008-01-01

Sensitive and accurate characterization of films thinner than a few nm used in nanoelectronics represents a challenge for many conventional production metrology tools. With capabilities in the 10 10 at/cm 2 , methods usually dedicated to contamination analysis appear promising, especially Total-reflection X-Ray Fluorescence (TXRF). This study shows that under usual configuration for contamination analysis, with incident angle smaller than the critical angle of the substrate, TXRF signal saturation occurs very rapidly for dense films (below 0.5 nm for HfO 2 films on Si wafers using a 9.67 keV excitation at 0.5 deg.). Increasing the incident angle, the range of linear results can be extended, but on the other hand, the TXRF sensitivity is degraded because of a strong increase of the measurement dead time. On HfO 2 films grown on Si wafers, an incident angle of 0.32 deg. corresponding to a dead time of 95% was used to achieve linear analysis up to 2 nm. Composition analysis by TXRF, and especially the detection of minor elements into thin films, requires the use of a specific incident angle to optimize sensitivity. Although quantitative analyses might require specific calibration, this work shows on Co-based films that the ratio between minor elements (W, P, Mo) and Co taking into account their relative sensitivity factors is a good direct reading of the composition

Raman scattering and attenuated-total-reflection studies of surface-plasmon polaritons

International Nuclear Information System (INIS)

Kurosawa, K.; Pierce, R.M.; Ushioda, S.; Hemminger, J.C.

1986-01-01

We have made in situ measurements of attenuated total reflection (ATR) and Raman scattering from a layered structure consisting of a glass prism, a thin silver film, an MgF 2 spacer, and a liquid mixture whose refractive index is matched to that of MgF 2 . When the incident angle of the laser beam coincides with the ATR angle, the surface-plasmon polariton (SPP) of the silver film is excited resonantly and the Raman scattering intensity of the liquid shows a maximum. The same effect is observed at the frequency of the Stokes scattered light. By measuring the decrease of the Raman scattering intensity of the liquid with increase of the thickness of the MgF 2 spacer layer, we have determined the decay length (l/sub d/) of the SPP field into the liquid. The measured value of l/sub d/ = 1539 A agrees with the calculated value, 1534 A

Analysis of some chosen elements of cerebrospinal fluid and serum in amyotrophic lateral sclerosis patients by total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Ostachowicz, B.; Lankosz, M.; Tomik, B.; Adamek, D.; Wobrauschek, P.; Streli, C.; Kregsamer, P.

2006-01-01

Trace elements play an important role in the human central nervous system. Significant variations of the concentration of trace elements in body fluids may occur in neurodegenerative diseases. In the present work an investigation of the elemental composition of the serum, and the cerebrospinal fluid in amyotrophic lateral sclerosis patients and a control group was performed. For the analysis of the body fluids Total reflection X-ray Fluorescence (TXRF) spectrometry was used. The samples were taken during routine diagnostic procedures. Na, Mg, Cl, K, Ca, Cu, Zn, and Br were determined in both fluids. In order to validate the results of analysis a serum standard reference material was measured. A t-test was applied to check if the mean concentrations of the elements are different for ALS and the control group. For the serum samples higher values for Br were found in the ALS group, for the cerebrospinal fluid lower values of Na, Mg and Zn as well as higher Ca values were found in the ALS group compared to the control group

Analysis of some chosen elements of cerebrospinal fluid and serum in amyotrophic lateral sclerosis patients by total reflection X-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Ostachowicz, B. [Department of Radiometric Analyses, Faculty of Physic and Applied Computer Science, AGH, University of Science and Technology, Cracow (Poland); Lankosz, M. [Department of Radiometric Analyses, Faculty of Physic and Applied Computer Science, AGH, University of Science and Technology, Cracow (Poland); Tomik, B. [Institute of Neurology, Collegium Medicum, Jagiellonian University, Cracow (Poland); Adamek, D. [Institute of Neurology, Collegium Medicum, Jagiellonian University, Cracow (Poland); Wobrauschek, P. [Atominstitut, Vienna University of Technology, Vienna (Austria); Streli, C. [Atominstitut, Vienna University of Technology, Vienna (Austria)]. E-mail: streli@ati.ac.at; Kregsamer, P. [Atominstitut, Vienna University of Technology, Vienna (Austria)

2006-11-15

Trace elements play an important role in the human central nervous system. Significant variations of the concentration of trace elements in body fluids may occur in neurodegenerative diseases. In the present work an investigation of the elemental composition of the serum, and the cerebrospinal fluid in amyotrophic lateral sclerosis patients and a control group was performed. For the analysis of the body fluids Total reflection X-ray Fluorescence (TXRF) spectrometry was used. The samples were taken during routine diagnostic procedures. Na, Mg, Cl, K, Ca, Cu, Zn, and Br were determined in both fluids. In order to validate the results of analysis a serum standard reference material was measured. A t-test was applied to check if the mean concentrations of the elements are different for ALS and the control group. For the serum samples higher values for Br were found in the ALS group, for the cerebrospinal fluid lower values of Na, Mg and Zn as well as higher Ca values were found in the ALS group compared to the control group.

Application of fiber-optic attenuated total reflection-FT-IR methods for in situ characterization of protein delivery systems in real time.

Science.gov (United States)

McFearin, Cathryn L; Sankaranarayanan, Jagadis; Almutairi, Adah

2011-05-15

A fiber-optic coupled attenuated total reflection (ATR)-FT-IR spectroscopy technique was applied to the study of two different therapeutic delivery systems, acid degradable hydrogels and nanoparticles. Real time exponential release of a model protein, human serum albumin (HSA), was observed from two different polymeric hydrogels formulated with a pH sensitive cross-linker. Spectroscopic examination of nanoparticles formulated with an acid degradable polymer shell and encapsulated HSA exhibited vibrational signatures characteristic of both particle and payload when exposed to lowered pH conditions, demonstrating the ability of this methodology to simultaneously measure phenomena arising from a system with a mixture of components. In addition, thorough characterization of these pH sensitive delivery vehicles without encapsulated protein was also accomplished in order to separate the effects of the payload during degradation. When in situ, real time detection in combination with the ability to specifically identify different components in a mixture without involved sample preparation and minimal sample disturbance is provided, the versatility and suitability of this type of experiment for research in the pharmaceutical field is demonstrated.

Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

Directory of Open Access Journals (Sweden)

Ronald Nguele

2014-11-01

Full Text Available On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long run, cause lubricant degradation while carbonyl oxidation was observed to occur only at a slow rate. Based upon data obtained from infrared spectra and using a curve fitting technique, mathematical equations predicting the theoretical rates of chemical change due to the aforementioned processes were examined. Additive depletions were found to obey exponential regression rather than polynomial. Moreover, breakpoint (breakpoint is used here to denote the initiation of deterioration of additives and critical mileage (critical mileage defines the distance at which the lubricant is chemically unusable of both samples were determined.

Studying flow close to an interface by total internal reflection fluorescence cross-correlation spectroscopy: Quantitative data analysis

Science.gov (United States)

Schmitz, R.; Yordanov, S.; Butt, H. J.; Koynov, K.; Dünweg, B.

2011-12-01

Total internal reflection fluorescence cross-correlation spectroscopy (TIR-FCCS) has recently [S. Yordanov , Optics ExpressOPEXFF1094-408710.1364/OE.17.021149 17, 21149 (2009)] been established as an experimental method to probe hydrodynamic flows near surfaces, on length scales of tens of nanometers. Its main advantage is that fluorescence occurs only for tracer particles close to the surface, thus resulting in high sensitivity. However, the measured correlation functions provide only rather indirect information about the flow parameters of interest, such as the shear rate and the slip length. In the present paper, we show how to combine detailed and fairly realistic theoretical modeling of the phenomena by Brownian dynamics simulations with accurate measurements of the correlation functions, in order to establish a quantitative method to retrieve the flow properties from the experiments. First, Brownian dynamics is used to sample highly accurate correlation functions for a fixed set of model parameters. Second, these parameters are varied systematically by means of an importance-sampling Monte Carlo procedure in order to fit the experiments. This provides the optimum parameter values together with their statistical error bars. The approach is well suited for massively parallel computers, which allows us to do the data analysis within moderate computing times. The method is applied to flow near a hydrophilic surface, where the slip length is observed to be smaller than 10nm, and, within the limitations of the experiments and the model, indistinguishable from zero.

The Advantages of an Attenuated Total Internal Reflection Infrared Microspectroscopic Imaging Technique for the Analysis of Polymer Laminates.

Science.gov (United States)

Ling, Chen; Sommer, André J

2015-06-01

Until recently, the analysis of polymer laminates using infrared microspectroscopy involved the painstaking separation of individual layers by dissection or by obtaining micrometer thin cross-sections. The latter usually requires the expertise of an individual trained in microtomy and even then, the very structure of the laminate could affect the outcome of the spectral results. The recent development of attenuated total internal reflection (ATR) infrared microspectroscopy imaging has provided a new avenue for the analysis of these multilayer structures. This report compares ATR infrared microspectroscopy imaging with conventional transmission infrared microspectroscopy imaging. The results demonstrate that the ATR method offers improved spatial resolution, eliminates a variety of competing optical processes, and requires minimal sample preparation relative to transmission measurements. These advantages were illustrated using a polymer laminate consisting of 11 different layers whose thickness ranged in size from 4-20 μm. The spatial resolution achieved by using an ATR-FTIR (Fourier transform infrared spectroscopy) imaging technique was diffraction limited. Contrast in the ATR images was enhanced by principal component analysis.

Biofilms as bio-indicator for polluted waters? Total reflection X-ray fluorescence analysis of biofilms of the Tisza river (Hungary)

Energy Technology Data Exchange (ETDEWEB)

Mages, Margarete; Ovari, Mihaly; Tuempling, Wolf v. [Department of Inland Water Research Magdeburg, UFZ Centre for Environmental Research Leipzig-Halle, Brueckstrasse 3a, 39114, Magdeburg (Germany); Kroepfl, Krisztina [Department of Chemical Technology and Environmental Chemistry, Eoetvoes University, Pazmany Peter setany 1/A, 1117, Budapest (Hungary)

2004-02-01

The aim of this work was to investigate the heavy metal accumulation by natural biofilms living in the catchment area of the Tisza river in Hungary, as well as in biofilms cultivated in vitro. Laboratory tests have demonstrated that metals can be adsorbed on biofilms, depending on their concentration and on the availability of free sorptive places. Biofilms were cultivated in vitro in natural freshwater from the Saale river, Germany. After reaching the plateau phase, Cu was added to reach a concentration of 100 {mu}g/L. An increase of its mass fraction in the biofilm was observed, which caused the decrease of the concentration in the water phase. Unfortunately, the reactor wall was also found to act as adsorbent for Cu. More detailed results of our in vitro experiments will be published in a forthcoming paper. Naturally grown biofilm samples from exposed as well as background places at the Hungarian rivers Szamos and Tisza were collected in 2000 and 2002 after the cyanide spill, and analysed using total reflection X-ray fluorescence analysis (TXRF). Metal mass fraction differences as high as two orders of magnitude were found between polluted and unpolluted (background) sampling points. Extremely high concentration values, e.g. 5600 {mu}g/g Zn in biofilm, were found at highly polluted sampling points. This means an enrichment factor of ca. 10,000 compared to the water phase. (orig.)

Using mid-Infrared External Reflectance Spectroscopy to Distinguish Between Different Commercially Produced Poly[Methyl MethAcrylate] (PMMA) Samples - A Null Result

Science.gov (United States)

Fajardo, Mario; Neel, Christopher; Lacina, David

2017-06-01

We report (null) results of experiments testing the hypothesis that mid-infrared (mid-IR) spectroscopy can be used to distinguish samples of poly[methyl methacrylate] (PMMA) obtained from different commercial suppliers. This work was motivated by the desire for a simple non-destructive and non-invasive test for pre-sorting PMMA samples prior to use in shock and high-strain-rate experiments, where PMMA is commonly used as a standard material. We discuss: our choice of mid-IR external reflectance spectroscopy, our approach to recording reflectance spectra at near-normal (θ = 0 + / - 5 degree) incidence and for extracting the wavelength-weighted absorption spectrum from the raw reflectance data via a Kramers-Krönig analysis. We employ extensive signal, which necessitates adopting a special experimental protocol to mitigate the effects of instrumental drift. Finally, we report spectra of three PMMA samples with different commercial pedigrees, and show that they are virtually identical (+ / - 1 % error, 95% confidence); obviating the use of mid-IR reflectance spectroscopy to tell the samples apart.

Seasonal determination of trace and ultra-trace content in Macrocystis pyrifera from San Jorge Gulf (Patagonia) by Total Reflection X-ray Fluorescence

Science.gov (United States)

Salomone, Vanesa N.; Riera, Marina; Cerchietti, Luciana; Custo, Graciela; Muniain, Claudia

2017-05-01

Seaweed have a great capacity to accumulate heavy metals in their tissues. The chemical characterization of seaweed is important due to their use in environmental monitoring and human or animal food. The aim of the present study was to evaluate the multi-elemental composition of seaweed from San Jorge Gulf (Patagonia, Argentina) by Total Reflection X-ray Fluorescence (TXRF). The elements As, Br, Cu, Cr, Fe, Mn, Ni, Pb, Rb, Sr, V and Zn were seasonally analyzed and quantified in blades of Macrocystis pyrifera. TXRF showed to be a suitable technique for simultaneous multi-element analysis in this kind of samples. The results revealed seasonal variations in the chemical content for some elements; arsenic content was maximum in summer and autumn, iron concentration increased to the winter and zinc concentration was maximum in autumn. The sum of principal micronutrients (Fe + Zn + Mn + Cu) varied between 114 and 171 mg k- 1 g dw. The total As concentration ranged between 36 and 66 mg kg- 1. Lead, nickel and copper were not detected.

Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy

International Nuclear Information System (INIS)

Zarazua O, G.; Carapia M, L.

2000-01-01

This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

Total reflection x-ray fluorescence (TXRF) - a tool to obtain information about different air masses and air pollution

International Nuclear Information System (INIS)

Schmeling, M.

2000-01-01

Aerosols are solid particles dissolved in the atmosphere and have strong influence in the earth climate. Their solid surfaces are the only atmospheric medium for condensation of water leading to cloud formation and ultimately to precipitation. Besides their role in cloud formation, the elemental composition of aerosols reveals useful information about air masses and their transport patterns as well as air pollution. The elemental composition can be considered like a fingerprint of an air mass telling the story about its origin and fate. The presence of Al, Ti and Fe for instance indicates a source located in a highly exposed soil or often desert region, whereas Ni, V and Pb can be traced back to anthropogenic activities like fuel combustion or industrial processes. Other important source regions are the oceans, which emit the main aerosol constituents Na, Cl, and S. The concentrations of these elements in the atmosphere are extremely low and long sampling times are necessary to gain reliable results with most of the common analysis techniques. In contrast to this total reflection x-ray fluorescence (TXRF), as a technique capable to cope with tiny sample amounts, offers the unique possibility to reduce collection times to a minimum of minutes to hours. Such short sampling times in turn render it possible to monitor different air masses either passing through a ground based station or -in the ideal case- flown into by a small research aircraft. Different aerosol samples were taken by aircraft during the second aerosol characterization experiment (ACE-2) with sampling times ranging from 15 minutes up to one hour. These filter samples were analyzed by TXRF for trace elements subsequently. Together with background information about back trajectories and size distribution covering the time of sampling the presence of different air masses could be detected. In another project, short-term samples in the Chicago/Lake Michigan area are collected to study the air mass

Analysis of Leucaena mimosine, Acacia tannins and total phenols by near infrared reflectance spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Prasad, M N.V. [Hyderabad Univ. (India). Dept. of Plant Sciences

1995-11-01

The mimosine contents of Leucaena foliage, Acacia tannins and total phenols from leaf, bark and pod were analyzed by a near infrared relectance spectrophotometer (Compscan 3000). A calibration equation (linear summation regression) was developed with near infrared spectral analysis software, using 30 spectra from old and young leaves of Leucaena and 23 spectra from different samples of Acacia. The near infrared analyzer calculated that the percentages of mimosine, total phenols and tannins are closely comparable to laboratory results. (author)

Characterization and quantitation of aprepitant drug substance polymorphs by attenuated total reflectance fourier transform infrared spectroscopy.

Science.gov (United States)

Helmy, Roy; Zhou, George X; Chen, Yadan W; Crocker, Louis; Wang, Tao; Wenslow, Robert M; Vailaya, Anant

2003-02-01

In this study, we report the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FT-IR) for the identification and quantitation of two polymorphs of Aprepitant, a substance P antagonist for chemotherapy-induced emesis. Mixtures of the polymorph pair were prepared by weight and ATR-FT-IR spectra of the powdered samples were obtained over the wavelength range of 700-1500 cm(-1). Significant spectral differences between the two polymorphs at 1140 cm(-1) show that ATR-FT-IR can provide definitive identification of the polymorphs. To investigate the feasibility of ATR-FT-IR for quantitation of polymorphic forms of Aprepitant, a calibration plot was constructed with known mixtures of the two polymorphs by plotting the peak ratio of the second derivative of absorbance spectra against the weight percent of form II in the polymorphic mixture. Using this novel approach, 3 wt % of one crystal form could be detected in mixtures of the two polymorphs. The accuracy of ATR-FT-IR in determining polymorph purity of the drug substance was tested by comparing the results with those obtained by X-ray powder diffractometry (XRPD). Indeed, polymorphic purity results obtained by ATR-FT-IR were found to be in good agreement with the predictions made by XRPD and compared favorably with actual values in the known mixtures. The present study clearly demonstrates the potential of ATR-FT-IR as a quick, easy, and inexpensive alternative to XRPD for the determination of polymorphic identity and purity of solid drug substances. The technique is ideally suited for polymorph analysis, because it is precise, accurate, and requires minimal sample preparation.

Assessment of serum selenium levels in 2-month-old sucking calves using total reflection technique

International Nuclear Information System (INIS)

Bernardini, D.; Testoni, S.; Buoso, M.C.; Ceccato, D.; Moschini, G.; Valdes, M.; Torboli, A.

2000-01-01

The assessment of selenium status of livestock is an important aspect of production medicine as evidence for the influence of low Se levels on disease resistance in ruminants is reviewed with emphasis on susceptibility to various pathologies (such as infections, exudative diathesis, pneumonia, pancreatic degeneration). Additional evidence suggests that Se deficiency may cause muscular dystrophy in calves, while, severe deficiency has been associated with cardiomyopathy and even death. Serum Se content is a good indicator of the short term Se status and reflects the recent dietary intake of the element. Since serum Se content is a good indicator of the short term status of the element and reflects the its recent dietary intake, the present work is aimed to determine Se concentration in serum from a group of 2 months old sucking calves suspected to be severely deficient. We used the TX 2000 X-ray spectrometer manufactured by Ital Structures. The energy resolution (FWHM) of the Si(Li) detector was 137 eV for Mn Kα. Among nuclear techniques the TXRF method is the best suitable for trace element analysis in liquid or dissolved samples and can deal much easier with elemental investigation. Physical basis of used analytical method, experimental set up and the sample preparation procedure are described. The concentration data obtained are presented and discussed. (author)

Near IR Scanning Angle Total Internal Reflection Raman Spectroscopy at Smooth Gold Films

Energy Technology Data Exchange (ETDEWEB)

McKee, Kristopher; Meyer, Matthew; Smith, Emily

2012-04-13

Total internal reflection (TIR) Raman and reflectivity spectra were collected for nonresonant analytes as a function of incident angle at sapphire or sapphire/smooth 50 nm gold interfaces using 785 nm excitation. For both interfaces, the Raman signal as a function of incident angle is well-modeled by the calculated interfacial mean square electric field (MSEF) relative to the incident field times the thickness of the layer being probed in the Raman measurement (D{sub RS}). The Raman scatter was reproducibly enhanced at the interface containing a gold film relative to the sapphire interface by a factor of 4.3–4.6 for aqueous pyridine or 2.2–3.7 for neat nitrobenzene, depending on the analyzed vibrational mode. The mechanism for the increased Raman signal is the enhanced MSEF at incident angles where propagating surface plasmons are excited in the metal film. The background from the TIR prism was reduced by 89–95% with the addition of the gold film, and the percent relative uncertainty in peak area was reduced from 15 to 1.7% for the 1347 cm–1 mode of nitrobenzene. Single monolayers of benzenethiol (S/N = 6.8) and 4-mercaptopyridine (S/N = 16.5) on gold films were measured by TIR Raman spectroscopy with 785 nm excitation (210 mW) without resonant enhancement in 1 min.

Detection and identification of multiple adulterants in plant food supplements using attenuated total reflectance-Infrared spectroscopy.

Science.gov (United States)

Deconinck, E; Aouadi, C; Bothy, J L; Courselle, P

2018-04-15

Due to the rising popularity of dietary supplements, especially plant food supplements, and alternative herbal medicines, a whole market developed and these products became freely available through internet. Though several searches revealed that at least a part of these products, especially the ones obtained from websites disclosing their physical identity, are aldulterated with pharmaceutical compounds. This causes a threat for public health, since these compounds are not declared and therefore adverse effects will not immediately be related to the product. The more the adulterants can interfere with other medicinal treatments. Since the present active pharmaceutical ingredients are not declared on the package and the products are sold as 100% natural or herbal in nature, it is very difficult for custom personnel to discriminate between products to be confiscated or not. Therefore easy to apply analytical approaches to discriminate between adulterated and non-adulterated products are necessary. This paper presents an approach based on infrared spectroscopy combined with attenuated total reflectance (ATR) and partial least squares- discriminant analysis (PLS-DA) to easily differentiate between adulterated and non- adulterated plant food supplements and to get a first idea of the nature of the adulterant present. The performance of PLS-DA models based on Mid-IR and NIR data were compared as well as models based on the combined data. Further three preprocessing strategies were compared. The best performance was obtained for a PLS-DA model using Mid-IR data with the second derivative as preprocessing method. This model showed a correct classification rate of 98.3% for an external test set. Also eight real samples were screened using the model and for seven of these samples a correct classification was obtained. Generally it could be concluded that the obtained model and the presented approach could be used at customs to discriminate between adulterated and non

Total reflection X-ray fluorescence measurements of S and P in proteins using a vacuum chamber specially designed for low Z elements

International Nuclear Information System (INIS)

Rauwolf, M.; Vanhoof, C.; Tirez, K.; Maes, E.; Ingerle, D.; Wobrauschek, P.; Streli, C.

2014-01-01

As the ratio of phosphorus and sulfur in proteins allows the determination of the phosphorylation degree in proteins, the absolute determination of phosphorus and sulfur in organic samples is of growing interest. While it takes some effort to quantify phosphorus and sulfur with inductively coupled quadrupole plasma mass spectrometry (ICP-QMS), total reflection X-ray fluorescence analysis (TXRF) allows easy quantification. In the presented work, the low Z TXRF spectrometer at the Atominstitut was used to analyze phosphorus and sulfur in proteins. Although the preparation of the protein samples proved to be more difficult than originally expected, it could be shown that TXRF is well suited for the determination of P and S in proteins. The obtained lower limits of detection (LLD) for P and S in proteins were extrapolated for 1000s and were 34 pg and 19 pg, respectively. The importance of height scans for each sample to exclude heterogeneities was demonstrated. - Highlights: • Low Z TXRF spectrometry was used to analyze phosphorus and sulfur in proteins. • TXRF is well suited for the determination of P and S in proteins. • Good detection limits for P (34 pg) and S (19 pg) were achieved. • Due to the detection limits, we propose that TXRF is a suitable method to analyze protein fractions

Quantification of total aluminium concentrations in food samples at trace levels by INAA and PIGE methods

International Nuclear Information System (INIS)

Nanda, Braja B.; Acharya, R.

2017-01-01

Total aluminium contents in various food samples were determined by Instrumental Neutron Activation Analysis (INAA) and Particle Induced Gamma-ray Emission (PIGE) methods. A total of 16 rice samples, collected from the field, were analyzed by INAA using reactor neutrons from Dhruva reactor. Whereas a total 17 spices collected from market, were analyzed by both INAA and PIGE methods in conjunction with high resolution gamma-ray spectrometry. Aluminium concentration values were found to be in the range of 19-845 mg kg -1 for spices and 15-104 mg kg -1 for rice samples. The methods were validated by analyzing standard reference materials (SRMs) form NIST. (author)

Determination of total concentration of chemically labeled metabolites as a means of metabolome sample normalization and sample loading optimization in mass spectrometry-based metabolomics.

Science.gov (United States)

Wu, Yiman; Li, Liang

2012-12-18

For mass spectrometry (MS)-based metabolomics, it is important to use the same amount of starting materials from each sample to compare the metabolome changes in two or more comparative samples. Unfortunately, for biological samples, the total amount or concentration of metabolites is difficult to determine. In this work, we report a general approach of determining the total concentration of metabolites based on the use of chemical labeling to attach a UV absorbent to the metabolites to be analyzed, followed by rapid step-gradient liquid chromatography (LC) UV detection of the labeled metabolites. It is shown that quantification of the total labeled analytes in a biological sample facilitates the preparation of an appropriate amount of starting materials for MS analysis as well as the optimization of the sample loading amount to a mass spectrometer for achieving optimal detectability. As an example, dansylation chemistry was used to label the amine- and phenol-containing metabolites in human urine samples. LC-UV quantification of the labeled metabolites could be optimally performed at the detection wavelength of 338 nm. A calibration curve established from the analysis of a mixture of 17 labeled amino acid standards was found to have the same slope as that from the analysis of the labeled urinary metabolites, suggesting that the labeled amino acid standard calibration curve could be used to determine the total concentration of the labeled urinary metabolites. A workflow incorporating this LC-UV metabolite quantification strategy was then developed in which all individual urine samples were first labeled with (12)C-dansylation and the concentration of each sample was determined by LC-UV. The volumes of urine samples taken for producing the pooled urine standard were adjusted to ensure an equal amount of labeled urine metabolites from each sample was used for the pooling. The pooled urine standard was then labeled with (13)C-dansylation. Equal amounts of the (12)C

Effect of modulation of the particle size distributions in the direct solid analysis by total-reflection X-ray fluorescence

Science.gov (United States)

Fernández-Ruiz, Ramón; Friedrich K., E. Josue; Redrejo, M. J.

2018-02-01

The main goal of this work was to investigate, in a systematic way, the influence of the controlled modulation of the particle size distribution of a representative solid sample with respect to the more relevant analytical parameters of the Direct Solid Analysis (DSA) by Total-reflection X-Ray Fluorescence (TXRF) quantitative method. In particular, accuracy, uncertainty, linearity and detection limits were correlated with the main parameters of their size distributions for the following elements; Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ba and Pb. In all cases strong correlations were finded. The main conclusion of this work can be resumed as follows; the modulation of particles shape to lower average sizes next to a minimization of the width of particle size distributions, produce a strong increment of accuracy, minimization of uncertainties and limit of detections for DSA-TXRF methodology. These achievements allow the future use of the DSA-TXRF analytical methodology for development of ISO norms and standardized protocols for the direct analysis of solids by mean of TXRF.

High accuracy subwavelength distance measurements: A variable-angle standing-wave total-internal-reflection optical microscope

International Nuclear Information System (INIS)

Haynie, A.; Min, T.-J.; Luan, L.; Mu, W.; Ketterson, J. B.

2009-01-01

We describe an extension of the total-internal-reflection microscopy technique that permits direct in-plane distance measurements with high accuracy (<10 nm) over a wide range of separations. This high position accuracy arises from the creation of a standing evanescent wave and the ability to sweep the nodal positions (intensity minima of the standing wave) in a controlled manner via both the incident angle and the relative phase of the incoming laser beams. Some control over the vertical resolution is available through the ability to scan the incoming angle and with it the evanescent penetration depth.

Mare Crisium - Regional stratigraphy and geologic history. [from spectral reflectivities of Lunik 24 samples

Science.gov (United States)

Adams, J. B.; Head, J. W., III; Mccord, T. B.; Pieters, C.; Zisk, S.

1978-01-01

Spectral reflectance measurements of five Luna 24 samples and new telescopic reflectance spectra of 10-20 km areas of seven sites in Mare Crisium have been used to calibrate multispectral images of mare units. Based on these data, three major mare units are defined in the Crisium basin and their stratigraphy is interpreted. The oldest mare unit is exposed in the ejecta of the craters Picard and Peirce and along the outer edge of the southeastern part of the basin. The next younger unit includes the Luna 24 site and generally follows a topographic annulus along the basin margin. The youngest mare unit occupies the central part of the basin. It is concluded that subsidence occurred throughout the emplacement of mare units, including extensive warping and downfaulting of the inner part of the Crisium basin.

Development of an ultra-compact mid-infrared attenuated total reflectance spectrophotometer

Science.gov (United States)

Kim, Dong Soo; Lee, Tae-Ro; Yoon, Gilwon

2014-07-01

Mid-infrared spectroscopy has been an important tool widely used for qualitative analysis in various fields. However, portable or personal use is size and cost prohibitive for either Fourier transform infrared or attenuated total reflectance (ATR) spectrophotometers. In this study, we developed an ultra-compact ATR spectrophotometer whose frequency band was 5.5-11.0 μm. We used miniature components, such as a light source fabricated by semiconductor technology, a linear variable filter, and a pyro-electric array detector. There were no moving parts. Optimal design based on two light sources, a zippered configuration of the array detector and ATR optics could produce absorption spectra that might be used for qualitative analysis. A microprocessor synchronized the pulsed light sources and detector, and all the signals were processed digitally. The size was 13.5×8.5×3.5 cm3 and the weight was 300 grams. Due to its low cost, our spectrophotometer can replace many online monitoring devices. Another application could be for a u-healthcare system installed in the bathroom or attached to a smartphone for monitoring substances in body fluids.

Determination of platinum group metal catalyst residues in active pharmaceutical ingredients by means of total reflection X-ray spectrometry

International Nuclear Information System (INIS)

Marguí, Eva; Queralt, Ignasi; Hidalgo, Manuela

2013-01-01

The control of metal catalyst residues (i.e., platinum group metals (PGMs)) in different stages of the manufacturing processes of the active pharmaceutical ingredients (APIs) and, especially, in the final product is crucial. For API specimens, there are strict guidelines to limit the levels of metal residues based on their individual levels of safety concern. For PGMs the concentration limit has been established at 10 mg/kg in the API. Therefore great effort is currently being devoted to the development of new and simple procedures to control metals in pharmaceuticals. In the present work, an analytical methodology based on benchtop total reflection X-ray fluorescence spectrometry (TXRF) has been developed for the rapid and simple determination of some PGM catalyst impurities (Rh, Pd, Ir and Pt) in different types of API samples. An evaluation of different sample treatments (dissolution and digestion of the solid pharmaceutical samples) has been carried out and the developed methodologies have been validated according to the analytical parameters to be considered and acceptance criteria for PGM determination according to the United States Pharmacopeia (USP). Limits of quantification obtained for PGM metals were in the range of 2–4 mg/kg which are satisfactory according to current legislation. From the obtained results it is shown that the developed TXRF method can be implemented in the pharmaceutical industries to increase productivity of the laboratory; offering an interesting and complementary analytical tool to other atomic spectroscopic methods. - Highlights: • A TXRF method for PGM catalyst residue determination in API samples is presented. • Analysis can be performed using 10 μL of the internal standardized dissolved API. • The method is rapid, simple and suitable according to the USP requirements

Disposable attenuated total reflection-infrared crystals from silicon wafer: a versatile approach to surface infrared spectroscopy.

Science.gov (United States)

Karabudak, Engin; Kas, Recep; Ogieglo, Wojciech; Rafieian, Damon; Schlautmann, Stefan; Lammertink, R G H; Gardeniers, Han J G E; Mul, Guido

2013-01-02

Attenuated total reflection-infrared (ATR-IR) spectroscopy is increasingly used to characterize solids and liquids as well as (catalytic) chemical conversion. Here we demonstrate that a piece of silicon wafer cut by a dicing machine or cleaved manually can be used as disposable internal reflection element (IRE) without the need for polishing and laborious edge preparation. Technical aspects, fundamental differences, and pros and cons of these novel disposable IREs and commercial IREs are discussed. The use of a crystal (the Si wafer) in a disposable manner enables simultaneous preparation and analysis of substrates and application of ATR spectroscopy in high temperature processes that may lead to irreversible interaction between the crystal and the substrate. As representative application examples, the disposable IREs were used to study high temperature thermal decomposition and chemical changes of polyvinyl alcohol (PVA) in a titania (TiO(2)) matrix and assemblies of 65-450 nm thick polystyrene (PS) films.

Total reflection X-ray fluorescence analysis of oral fluids of women affected by osteoporosis and osteopenia

Science.gov (United States)

Sánchez, Héctor Jorge; Valentinuzzi, María Cecilia; Grenón, Miram; Abraham, José

2008-12-01

Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures; the early stage of decreased bone density is called osteopenia. More than 200 million people are affected and about 50% of post-menopausic women are expected to develop the disease. Osteoporosis, osteopenia and periodontal disease have in common several risk factors, being hyperthyroidism and smoking habits the most important ones. There is scarce information in the literature about the association between periodontal disease and osteoporosis and/or osteopenia. Some works suggest that osteoporotic women are susceptible to a higher loss of periodontal insertion, alveolar bones, and teeth. Thirty adult post-menopausic women were studied; some of them were healthy (control group) and the rest of them were undergoing some stage of osteoporosis or osteopenia. All the subjects were healthy, non-smokers, not having dental implants, and with communitarian periodontal index higher than 1(CPI > 1). Samples of saliva and gingival crevice fluid were extracted with calibrated micro-capillaries and deposited on Si reflectors. Known amounts of Ga were added to the samples in order to act as internal standard for quantification by the total reflection x-ray fluorescence technique. Experimental concentrations of several elements (P, S, Cl, K, Ca, Cr, Fe, NI, Cu, and Zn) were determined. The concentration of some elements in saliva showed different behavior as compared to gingival crevice fluid. Some critical elements of bone composition, such as Ca and Zn, present very distinguishable behavior. Improvements in the statistics are required for a better assessment of a routine method and to establish some correlation with periodontal disease. TXRF seems to be a promising method to evaluate the evolution of osteoporosis.

Total reflection X-ray fluorescence analysis of oral fluids of women affected by osteoporosis and osteopenia

International Nuclear Information System (INIS)

Sanchez, Hector Jorge; Valentinuzzi, Maria Cecilia; Grenon, Miram; Abraham, Jose

2008-01-01

Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures; the early stage of decreased bone density is called osteopenia. More than 200 million people are affected and about 50% of post-menopausic women are expected to develop the disease. Osteoporosis, osteopenia and periodontal disease have in common several risk factors, being hyperthyroidism and smoking habits the most important ones. There is scarce information in the literature about the association between periodontal disease and osteoporosis and/or osteopenia. Some works suggest that osteoporotic women are susceptible to a higher loss of periodontal insertion, alveolar bones, and teeth. Thirty adult post-menopausic women were studied; some of them were healthy (control group) and the rest of them were undergoing some stage of osteoporosis or osteopenia. All the subjects were healthy, non-smokers, not having dental implants, and with communitarian periodontal index higher than 1(CPI > 1). Samples of saliva and gingival crevice fluid were extracted with calibrated micro-capillaries and deposited on Si reflectors. Known amounts of Ga were added to the samples in order to act as internal standard for quantification by the total reflection x-ray fluorescence technique. Experimental concentrations of several elements (P, S, Cl, K, Ca, Cr, Fe, NI, Cu, and Zn) were determined. The concentration of some elements in saliva showed different behavior as compared to gingival crevice fluid. Some critical elements of bone composition, such as Ca and Zn, present very distinguishable behavior. Improvements in the statistics are required for a better assessment of a routine method and to establish some correlation with periodontal disease. TXRF seems to be a promising method to evaluate the evolution of osteoporosis

Total reflection X-ray fluorescence analysis of oral fluids of women affected by osteoporosis and osteopenia

Energy Technology Data Exchange (ETDEWEB)

Sanchez, Hector Jorge [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)], E-mail: jsan@famaf.unc.edu.ar; Valentinuzzi, Maria Cecilia [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Grenon, Miram [Facultad de Odontologia, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina); Abraham, Jose [Facultad de Matematica Astronomia y Fisica, Universidad Nacional de Cordoba, 5000 Cordoba (Argentina)

2008-12-15

Osteoporosis is a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to bone fragility and an increased susceptibility to fractures; the early stage of decreased bone density is called osteopenia. More than 200 million people are affected and about 50% of post-menopausic women are expected to develop the disease. Osteoporosis, osteopenia and periodontal disease have in common several risk factors, being hyperthyroidism and smoking habits the most important ones. There is scarce information in the literature about the association between periodontal disease and osteoporosis and/or osteopenia. Some works suggest that osteoporotic women are susceptible to a higher loss of periodontal insertion, alveolar bones, and teeth. Thirty adult post-menopausic women were studied; some of them were healthy (control group) and the rest of them were undergoing some stage of osteoporosis or osteopenia. All the subjects were healthy, non-smokers, not having dental implants, and with communitarian periodontal index higher than 1(CPI > 1). Samples of saliva and gingival crevice fluid were extracted with calibrated micro-capillaries and deposited on Si reflectors. Known amounts of Ga were added to the samples in order to act as internal standard for quantification by the total reflection x-ray fluorescence technique. Experimental concentrations of several elements (P, S, Cl, K, Ca, Cr, Fe, NI, Cu, and Zn) were determined. The concentration of some elements in saliva showed different behavior as compared to gingival crevice fluid. Some critical elements of bone composition, such as Ca and Zn, present very distinguishable behavior. Improvements in the statistics are required for a better assessment of a routine method and to establish some correlation with periodontal disease. TXRF seems to be a promising method to evaluate the evolution of osteoporosis.

Two different preparation techniques for trace element determination of single Daphnia specimen using total reflection x-ray fluorescence analysis (TXRF)

International Nuclear Information System (INIS)

Woelfl, S.; Mages, M.

2000-01-01

Bio accumulation gives first information about the bio-availability of elements in waters and becomes more and more important for the characterization of the water quality. The use of common analytical techniques like ICP-MS and AAS requires large quantities of biologic sample material. Single preparation for example of Daphnia, a common species for bio-test experiments, are hardly possible with these procedures. Therefore alternatively quantitative TXRF element determination of individually prepared Daphnia was developed. Two preparation techniques for single freshwater crustacean specimen from a eutrophic branch of the river Elbe in the 'Rothehorn Park', Magdeburg (Daphnia: dry weight: 10 - 50 μg individuum -1 ) had been tested: (1) Wet preparation: the single Daphnia specimen had been washed with 0.45 μm filtered lake water and put onto quartz sample carriers. After air drying, the body length were determined in order to calculate the dry weight according to previously established body lengths-dry weight relationships. (2) Dry preparation: after collection specimen were washed with 0.45 μm filtered lake water and frozen in liquid nitrogen. The individual lyophilisated dried Daphnia were weighted using an ultrafine micro-balance and put onto quartz sample carriers. After preparation, addition of some μl Gallium standard solution and air drying the individual Daphnia were digested at the quartz sample carriers with 10 μl HNO 3 on a hot plate and dried once more. Finally the element concentrations were determined using a EXTRA IIA total-reflection x-ray fluorescence spectrometer. As a result of these investigations we can conclude that both, the 'dry' and 'wet' preparation method can be used for the element determination in small single crustaceans using TXRF spectrometry. It seems that the 'dry' method yields more precise results, but the wet method is easier to handle in field when samples cannot be fixed with liquid nitrogen. (author)

Study of air pollution in terms of heavy metals and particulate matter at Ambodin'isotry using the technique of total reflection X-ray fluorescence

International Nuclear Information System (INIS)

AHMED, H.

2011-01-01

The present work is devoted to study the air pollution in terms of particulate matters and heavy metals in Ambodin'isotry in Antananarivo city by the method of total reflection X-ray fluorescence. This work has been done within the Institut National des Sciences et Techniques Nucleaires (Madagascar-INSTN). GENT air sampler has been used for the collections of the aerosol samples. This air sampler is placed at about 7 meters above the ground in order to avoid the contaminations. The samplings were carried out from 14 April to 29 August 2008. The duration of sampling is 24 hours. The results show that the analyzed aerosol samples contain the elements like the titanium , the chromium, the manganese, the iron, the nickel, the copper, the zinc, the bromine, the strontium and the lead. The average concentrations in element lead are lower than the standards ones adopted by the World Health Organization (WHO) (500 ng.m -3 ) and the United States Environmental Protection Agency (US EPA) (1500 ng.m -3 ). The total average concentrations in element lead are lower than the standards ones adopted by the World Health Organization (WHO) (500 ng.m -3 ). The total of average concentrations in lead doesn't present a danger for the population of Ambodin'isotry. The average concentrations of PM10 in the aerosols do not respect the guideline values of 50μg.m -3 adopted by the WHO and the European Union according to the directive 2005 and those of PM 2.5 exceed extensively the guideline values of the WHO (25μg.m -3 ) and of the US EPA (35μg.m -3 ). Consequently, the site of Ambodin'Isotry is polluted in term of airborne particulate matters. The calculation of enrichment factors by Mason's model shows the titanium, the iron, the nickel and the strontium are natural origin while the chromium, the nickel, the copper, the zinc, the bromine and the lead are from anthropogenic sources. [fr

Single particle transfer for quantitative analysis with total-reflection X-ray fluorescence spectrometry

International Nuclear Information System (INIS)

Esaka, Fumitaka; Esaka, Konomi T.; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu; Watanabe, Kazuo

2006-01-01

The technique of single particle transfer was applied to quantitative analysis with total-reflection X-ray fluorescence (TXRF) spectrometry. The technique was evaluated by performing quantitative analysis of individual Cu particles with diameters between 3.9 and 13.2 μm. The direct quantitative analysis of the Cu particle transferred onto a Si carrier gave a discrepancy between measured and calculated Cu amounts due to the absorption effects of incident and fluorescent X-rays within the particle. By the correction for the absorption effects, the Cu amounts in individual particles could be determined with the deviation within 10.5%. When the Cu particles were dissolved with HNO 3 solution prior to the TXRF analysis, the deviation was improved to be within 3.8%. In this case, no correction for the absorption effects was needed for quantification

In Situ Focused Beam Reflectance Measurement (FBRM, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR and Raman Characterization of the Polymorphic Transformation of Carbamazepine

Directory of Open Access Journals (Sweden)

Sohrab Rohani

2012-02-01

Full Text Available The objective of this work was to study the polymorphic transformation of carbamazepine from Form II to Form III in 1-propanol during seeded isothermal batch crystallization. First, the pure Form II and Form III were obtained and characterized. Then their solubilities and metastable zone limits were measured by in-situ attenuated total reflectance Fourier transform infrared (ATR-FTIR spectroscopy and focused beam reflectance measurement (FBRM. A transition temperature at about 34.2 °C was deduced suggesting the enantiotropic nature of this compound over the studied temperature range. To quantify the polymorph ratio during the transformation process, a new in-situ quantitative method was developed to measure the fraction of Form II by Raman spectroscopy. Successful tracking of the nucleation of the stable form and the transformation from Form II to Form III during isothermal crystallization was achieved by Raman spectroscopy and FBRM. The results from these three in-situ techniques, FBRM, FTIR and Raman were consistent with each other. The results showed a strong dependency on the amount of seeds added during isothermal crystallization.

Total internal reflection sum-frequency generation spectroscopy and dense gold nanoparticles monolayer: a route for probing adsorbed molecules

International Nuclear Information System (INIS)

Tourillon, Gerard; Dreesen, Laurent; Volcke, Cedric; Sartenaer, Yannick; Thiry, Paul A; Peremans, Andre

2007-01-01

We show that sum-frequency generation spectroscopy performed in the total internal reflection configuration (TIR-SFG) combined with a dense gold nanoparticles monolayer allows us to study, with an excellent signal to noise ratio and high signal to background ratio, the conformation of adsorbed molecules. Dodecanethiol (DDT) was used as probe molecules in order to assess the potentialities of the approach. An enhancement of more than one order of magnitude of the SFG signals arising from the adsorbed species is observed with the TIR geometry compared to the external reflection one while the SFG non-resonant contribution remains the same for both configurations. Although further work is required to fully understand the origin of the SFG process on nanoparticles, our work opens new possibilities for studying nanostructures

A Comparison of "Total Dust" and Inhalable Personal Sampling for Beryllium Exposure

Energy Technology Data Exchange (ETDEWEB)

Carter, Colleen M. [Tulane Univ., New Orleans, LA (United States). School of Public Health and Tropical Medicine

2012-05-09

In 2009, the American Conference of Governmental Industrial Hygienists (ACGIH) reduced the Beryllium (Be) 8-hr Time Weighted Average Threshold Limit Value (TLV-TWA) from 2.0 μg/m³ to 0.05 μg/m³ with an inhalable 'I' designation in accordance with ACGIH's particle size-selective criterion for inhalable mass. Currently, per the Department of Energy (DOE) requirements, the Lawrence Livermore National Laboratory (LLNL) is following the Occupational Health and Safety Administration (OSHA) Permissible Exposure Limit (PEL) of 2.0 μg/m³ as an 8-hr TWA, which is also the 2005 ACGIH TLV-TWA, and an Action Level (AL) of 0.2 μg/m³ and sampling is performed using the 37mm (total dust) sampling method. Since DOE is considering adopting the newer 2009 TLV guidelines, the goal of this study was to determine if the current method of sampling using the 37mm (total dust) sampler would produce results that are comparable to what would be measured using the IOM (inhalable) sampler specific to the application of high energy explosive work at LLNL's remote experimental test facility at Site 300. Side-by-side personal sampling using the two samplers was performed over an approximately two-week period during chamber re-entry and cleanup procedures following detonation of an explosive assembly containing Beryllium (Be). The average ratio of personal sampling results for the IOM (inhalable) vs. 37-mm (total dust) sampler was 1.1:1 with a P-value of 0.62, indicating that there was no statistically significant difference in the performance of the two samplers. Therefore, for the type of activity monitored during this study, the 37-mm sampling cassette would be considered a suitable alternative to the IOM sampler for collecting inhalable particulate matter, which is important given the many practical and economic advantages that it presents. However, similar comparison studies would be necessary for this conclusion to be

Registration of T-2 mycotoxin with total internal reflection ellipsometry and QCM impedance methods.

Science.gov (United States)

Nabok, A V; Tsargorodskaya, A; Holloway, A; Starodub, N F; Gojster, O

2007-01-15

A sensitive optical method of total internal reflection ellipsometry (TIRE) in conjunction with immune assay approach was exploited for the registration of T-2 mycotoxin in a wide range of concentrations from 100 microg/ml down to 0.15 ng/ml. Association constants of 1.4x10(6) and 1.9x10(7)mol(-1)s for poly- and monoclonal T-2 antibodies, respectively, were evaluated from TIRE kinetic measurements. According to TIRE data fitting, binding of T-2 molecules to antibodies (at saturation) has resulted in the increase in adsorbed layer thickness of 4-5 nm. The QCM impedance measurements data showed anomalously large mass increase and film softening, most likely, due to the binding of large T-2 aggregates to antibodies.

Determination of Cr, Mn, Fe, Co, Ni, Cu, Zn and As in the Rimac River waters by x-ray fluorescence in total reflection; Determinacion de Cr, Mn, Fe, Co, Ni, Cu, Zn y As en aguas del Rio Rimac por fluorescencia de rayos-x en reflexion total

Energy Technology Data Exchange (ETDEWEB)

Tiznado, W [Universidad Nacional Federico Villarreal, Lima (Peru). Facultad de Ciencias Naturales y Matematicas, EP Quimica; Olivera, P [Instituto Peruano de Energia Nuclear, Lima (Peru). Departamento de Quimica

2002-07-01

Samples from thirteen stations of the Rimac River has been analyzed. Samples were performed during one-year-period (september 1998-august 1999), with a frequency of one sample per month. The X-ray fluorescence analysis in total reflection technique has been used in order to determine the Cr, Mn, Fe, Co, Ni, Cu, Zn and As elements on its dissolved phase. The results obtained show: relation of the presence of mining stations with the metal concentration level, specially in the Zn and Fe; As is present in concentrations above those of permissible maximum levels in some of the sampled stations; moreover, Ni and Cr, toxic elements, are found in very low concentrations. On the other hand, it has been proved that the analysis method used is useful as a monitoring tool of superficial water-quality due to its low detection limits and because of the fastness the analysis are made.

Live Imaging of Cellular Internalization of Single Colloidal Particle by Combined Label-Free and Fluorescence Total Internal Reflection Microscopy.

Science.gov (United States)

Byrne, Gerard D; Vllasaliu, Driton; Falcone, Franco H; Somekh, Michael G; Stolnik, Snjezana

2015-11-02

In this work we utilize the combination of label-free total internal reflection microscopy and total internal reflectance fluorescence (TIRM/TIRF) microscopy to achieve a simultaneous, live imaging of single, label-free colloidal particle endocytosis by individual cells. The TIRM arm of the microscope enables label free imaging of the colloid and cell membrane features, while the TIRF arm images the dynamics of fluorescent-labeled clathrin (protein involved in endocytosis via clathrin pathway), expressed in transfected 3T3 fibroblasts cells. Using a model polymeric colloid and cells with a fluorescently tagged clathrin endocytosis pathway, we demonstrate that wide field TIRM/TIRF coimaging enables live visualization of the process of colloidal particle interaction with the labeled cell structure, which is valuable for discerning the membrane events and route of colloid internalization by the cell. We further show that 500 nm in diameter model polystyrene colloid associates with clathrin, prior to and during its cellular internalization. This association is not apparent with larger, 1 μm in diameter colloids, indicating an upper particle size limit for clathrin-mediated endocytosis.

Attenuated total reflection-Fourier transform infrared imaging of large areas using inverted prism crystals and combining imaging and mapping.

Science.gov (United States)

Chan, K L Andrew; Kazarian, Sergei G

2008-10-01

Attenuated total reflection-Fourier transform infrared (ATR-FT-IR) imaging is a very useful tool for capturing chemical images of various materials due to the simple sample preparation and the ability to measure wet samples or samples in an aqueous environment. However, the size of the array detector used for image acquisition is often limited and there is usually a trade off between spatial resolution and the field of view (FOV). The combination of mapping and imaging can be used to acquire images with a larger FOV without sacrificing spatial resolution. Previous attempts have demonstrated this using an infrared microscope and a Germanium hemispherical ATR crystal to achieve images of up to 2.5 mm x 2.5 mm but with varying spatial resolution and depth of penetration across the imaged area. In this paper, we demonstrate a combination of mapping and imaging with a different approach using an external optics housing for large ATR accessories and inverted ATR prisms to achieve ATR-FT-IR images with a large FOV and reasonable spatial resolution. The results have shown that a FOV of 10 mm x 14 mm can be obtained with a spatial resolution of approximately 40-60 microm when using an accessory that gives no magnification. A FOV of 1.3 mm x 1.3 mm can be obtained with spatial resolution of approximately 15-20 microm when using a diamond ATR imaging accessory with 4x magnification. No significant change in image quality such as spatial resolution or depth of penetration has been observed across the whole FOV with this method and the measurement time was approximately 15 minutes for an image consisting of 16 image tiles.

Creation of a reflecting formula to determine a patient's indication for undergoing total knee arthroplasty.

Science.gov (United States)

Chan, Wing P; Hsu, Shu-Mei; Huang, Guo-Shu; Yao, Min-Szu; Chang, Yue-Chune; Ho, Wei-Pin

2010-01-01

The aim of this study was to develop, from patients' characteristics and radiography, a formula reflecting the decision for total knee arthroplasty (TKA) in patients with a painful osteoarthritic knee. We reviewed medical records of 193 consecutive patients who had knee osteoarthritis and underwent primary TKA surgery and 133 consecutive patients with knee osteoarthritis who did not have surgery in one institution during the preceding 5 years. Two skeletal radiologists graded, from 0 to 3, radiographic joint space narrowing (JSN), osteophytes, subchondral sclerosis, and subchondral cysts. The association between the variables and outcome were calculated by the chi-squared test and multivariable logistic regression. Women had more TKAs than men (P = 0.002), and the TKA and non-TKA groups differed in terms of self-care ability (P osteophytes in the medial compartment. The retrospective sensitivity and specificity for patients who underwent TKA surgery were 84% and 83%, respectively. The diagnostic efficacy in retrospect evaluated by a receiver operating characteristic curve was 0.92. A formula reflecting the decision for TKA surgery in patients with a painful osteoarthritic knee has been developed with acceptable diagnostic efficacy obtained retrospectively. The formula should be validated by further study.

Assessing total and volatile solids in municipal solid waste samples.

Science.gov (United States)

Peces, M; Astals, S; Mata-Alvarez, J

2014-01-01

Municipal solid waste is broadly generated in everyday activities and its treatment is a global challenge. Total solids (TS) and volatile solids (VS) are typical control parameters measured in biological treatments. In this study, the TS and VS were determined using the standard methods, as well as introducing some variants: (i) the drying temperature for the TS assays was 105°C, 70°C and 50°C and (ii) the VS were determined using different heating ramps from room tempature to 550°C. TS could be determined at either 105°C or 70°C, but oven residence time was tripled at 70°C, increasing from 48 to 144 h. The VS could be determined by smouldering the sample (where the sample is burnt without a flame), which avoids the release of fumes and odours in the laboratory. However, smouldering can generate undesired pyrolysis products as a consequence of carbonization, which leads to VS being underestimated. Carbonization can be avoided using slow heating ramps to prevent the oxygen limitation. Furthermore, crushing the sample cores decreased the time to reach constant weight and decreased the potential to underestimate VS.

Label free imaging of cell-substrate contacts by holographic total internal reflection microscopy.

Science.gov (United States)

Mandracchia, Biagio; Gennari, Oriella; Marchesano, Valentina; Paturzo, Melania; Ferraro, Pietro

2017-09-01

The study of cell adhesion contacts is pivotal to understand cell mechanics and interaction at substrates or chemical and physical stimuli. We designed and built a HoloTIR microscope for label-free quantitative phase imaging of total internal reflection. Here we show for the first time that HoloTIR is a good choice for label-free study of focal contacts and of cell/substrate interaction as its sensitivity is enhanced in comparison with standard TIR microscopy. Finally, the simplicity of implementation and relative low cost, due to the requirement of less optical components, make HoloTIR a reasonable alternative, or even an addition, to TIRF microscopy for mapping cell/substratum topography. As a proof of concept, we studied the formation of focal contacts of fibroblasts on three substrates with different levels of affinity for cell adhesion. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS

OpenAIRE

Mataveli, Lidiane Raquel Verola; Buzzo, Márcia Liane; Arauz, Luciana Juncioni de; Carvalho, Maria de Fátima Henriques; Arakaki, Edna Emy Kumagai; Matsuzaki, Richard; Tiglea, Paulo

2016-01-01

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and rep...

Determination of metals by total reflection X-ray fluorescence and evaluation of toxicity of a river impacted by coal mining in the south of Brazil.

Science.gov (United States)

Lattuada, R M; Menezes, C T B; Pavei, P T; Peralba, M C R; Dos Santos, J H Z

2009-04-30

Metal (Fe, Mn, Zn, Ni, Cd, and Pb) concentrations in the region of Criciuma (Brazil), a region impacted by coal mining, were determined in water and sediments using total reflection X-ray fluorescence (TXRF) spectroscopy. Samples were collected from the Mãe Luzia River (south Brazil) at five different stations, from the source down to the river mouth (Ararangua estuary). Water and sediment toxicity were also evaluated using bioassays with Daphnia magna as the bioindicator. The metal present in the highest concentrations both in water (1.3-11 mg L(-1)) and in sediments (34-142 mg L(-1)) was iron. Results suggest an influence of coal mining on the aquatic receptors, showing a clear relationship between metal content (mostly Fe) and ecotoxicity.

Porous Silicon Antibody Microarrays for Quantitative Analysis: Measurement of Free and Total PSA in Clinical Plasma Samples

Science.gov (United States)

Tojo, Axel; Malm, Johan; Marko-Varga, György; Lilja, Hans; Laurell, Thomas

2014-01-01

The antibody microarrays have become widespread, but their use for quantitative analyses in clinical samples has not yet been established. We investigated an immunoassay based on nanoporous silicon antibody microarrays for quantification of total prostate-specific-antigen (PSA) in 80 clinical plasma samples, and provide quantitative data from a duplex microarray assay that simultaneously quantifies free and total PSA in plasma. To further develop the assay the porous silicon chips was placed into a standard 96-well microtiter plate for higher throughput analysis. The samples analyzed by this quantitative microarray were 80 plasma samples obtained from men undergoing clinical PSA testing (dynamic range: 0.14-44ng/ml, LOD: 0.14ng/ml). The second dataset, measuring free PSA (dynamic range: 0.40-74.9ng/ml, LOD: 0.47ng/ml) and total PSA (dynamic range: 0.87-295ng/ml, LOD: 0.76ng/ml), was also obtained from the clinical routine. The reference for the quantification was a commercially available assay, the ProStatus PSA Free/Total DELFIA. In an analysis of 80 plasma samples the microarray platform performs well across the range of total PSA levels. This assay might have the potential to substitute for the large-scale microtiter plate format in diagnostic applications. The duplex assay paves the way for a future quantitative multiplex assay, which analyses several prostate cancer biomarkers simultaneously. PMID:22921878

Total reflection X-ray fluorescence as a tool for food screening

Science.gov (United States)

Borgese, Laura; Bilo, Fabjola; Dalipi, Rogerta; Bontempi, Elza; Depero, Laura E.

2015-11-01

This review provides a comprehensive overview of the applications of total reflection X-ray fluorescence (TXRF) in the field of food analysis. Elemental composition of food is of great importance, since food is the main source of essential, major and trace elements for animals and humans. Some potentially toxic elements, dangerous for human health may contaminate food, entering the food chain from the environment, processing, and storage. For this reason the elemental analysis of food is fundamental for safety assessment. Fast and sensitive analytical techniques, able to detect major and trace elements, are required as a result of the increasing demand on multi-elemental information and product screening. TXRF is suitable for elemental analysis of food, since it provides simultaneous multi-elemental identification in a wide dynamic range of concentrations. Several different matrices may be analyzed obtaining results with a good precision and accuracy. In this review, the most recent literature about the use of TXRF for the analysis of food is reported. The focus is placed on the applications within food quality monitoring of drinks, beverages, vegetables, fruits, cereals, animal derivatives and dietary supplements. Furthermore, this paper provides a critical outlook on the developments required to transfer these methods from research to the industrial and analytical laboratories contexts.

Determination of total chromium in tanned leather samples used in car industry.

Science.gov (United States)

Zeiner, Michaela; Rezić, Iva; Ujević, Darko; Steffan, Ilse

2011-03-01

Despite the high competition of synthetic fibers leather is nowadays still widely used for many applications. In order to ensure a sufficient stability of the skin matrix against many factors, such as microbial degradation, heat and sweat, a tanning process is indispensable. Using chromium (III) for this purpose offers a multitude of advantages, thus this way of tanning is widely applied. During the use of chromium tanned leather as clothing material as well as for decoration/covering purposes, chromium is extracted from the leather and may then cause nocuous effects to human skin, e.g. allergic reactions. Thus the knowledge of the total chromium content of leather samples expected to come into prolonged touch with human skin is very important. In car industry leather is used as cover for seats, steering wheel and gearshift lever The chromium contents often chromium tanned leather samples used in car industry were determined. First all samples were dried at 65 degrees C overnight and then cut in small pieces using a ceramic knife, weighed and analyzed by inductively coupled plasma--optical emission spectrometry (ICP-OES) after acidic microwave assisted digestion. The total chromium amounts found were in the range from 19 mg/g up to 32 mg/g. The extraction yield of chromium from leather samples in sweat is approximately 2-7%. Thus especially during long journeys in summer chromium can be extracted in amounts which may cause nocuous effects for example on the palm of the hands or on the back.

Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy on Intact Dried Leaves of Sage (Salvia officinalis L.): Accelerated Chemotaxonomic Discrimination and Analysis of Essential Oil Composition.

Science.gov (United States)

Gudi, Gennadi; Krähmer, Andrea; Krüger, Hans; Schulz, Hartwig

2015-10-07

Sage (Salvia officinalis L.) is cultivated worldwide for its aromatic leaves, which are used as herbal spice, and for phytopharmaceutical applications. Fast analytical strategies for essential oil analysis, performed directly on plant material, would reduce the delay between sampling and analytical results. This would enhance product quality by improving technical control of cultivation. The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) method described here provides a reliable calibration model for quantification of essential oil components [EOCs; R(2) = 0.96; root-mean-square error of cross-validation (RMSECV) = 0.249 mL 100 g(-1) of dry matter (DM); and range = 1.115-5.280 mL 100 g(-1) of DM] and main constituents [e.g., α-thujone/β-thujone; R(2) = 0.97/0.86; RMSECV = 0.0581/0.0856 mL 100 g(-1) of DM; and range = 0.010-1.252/0.005-0.893 mL 100 g(-1) of DM] directly on dried intact leaves of sage. Except for drying, no further sample preparation is required for ATR-FTIR, and the measurement time of less than 5 min per sample contrasts with the most common alternative of hydrodistillation followed by gas chromatography analysis, which can take several hours per sample.

Determination of total and methylmercury compounds in the IAEA human hair intercomparison samples - Experience of the IAEA-MEL

International Nuclear Information System (INIS)

Horvat, M.; Liang, L.; Mandic, V.

1995-01-01

The programme of this CRP is focused on the analyses of human hair samples. There are only two human hair samples certified for total mercury, and no RMs for methylmercury compounds is available. One of the main objectives of this CRP is to produce, through the IAEA AQCS Programme, a human hair intercomparison material for quality assurance requirements in population monitoring programmes for total and methylmercury exposure. Through the reporting period, MESL has introduced a new method for simultaneous determination of total and methylmercury in biological samples. As the laboratory has close collaboration with the CRP's Reference Laboratory in Ljubljana, Slovenia, it has also been actively involved in the quality assurance component of this CRP. This report represents a summary on the results for total and methylmercury in two intercomparison samples, IAEA-085 and IAEA-086 using newly developed method

Sensing cocaine in saliva with attenuated total reflection infrared (ATR-IR) spectroscopy combined with a one-step extraction method

Science.gov (United States)

Hans, Kerstin M.-C.; Gianella, Michele; Sigrist, Markus W.

2012-03-01

On-site drug tests have gained importance, e.g., for protecting the society from impaired drivers. Since today's drug tests are majorly only positive/negative, there is a great need for a reliable, portable and preferentially quantitative drug test. In the project IrSens we aim to bridge this gap with the development of an optical sensor platform based on infrared spectroscopy and focus on cocaine detection in saliva. We combine a one-step extraction method, a sample drying technique and infrared attenuated total reflection (ATR) spectroscopy. As a first step we have developed an extraction technique that allows us to extract cocaine from saliva to an almost infrared-transparent solvent and to record ATR spectra with a commercially available Fourier Transform-infrared spectrometer. To the best of our knowledge this is the first time that such a simple and easy-to-use one-step extraction method is used to transfer cocaine from saliva into an organic solvent and detect it quantitatively. With this new method we are able to reach a current limit of detection around 10 μg/ml. This new extraction method could also be applied to waste water monitoring and controlling caffeine content in beverages.

Detection and quantitative determination of heavy metals in electronic cigarette refill liquids using Total Reflection X-ray Fluorescence Spectrometry.

Science.gov (United States)

Kamilari, Eleni; Farsalinos, Konstantinos; Poulas, Konstantinos; Kontoyannis, Christos G; Orkoula, Malvina G

2018-06-01

Electronic cigarettes are considered healthier alternatives to conventional cigarettes containing tobacco. They produce vapor through heating of the refill liquids (e-liquids) which consist of propylene glycol, vegetable glycerin, nicotine (in various concentrations), water and flavoring agents. Heavy metals may enter the refill liquid during the production, posing a risk for consumer's health due to their toxicity. The objective of the present study was the development of a methodology for the detection and quantitative analysis of cadmium (Cd), lead (Pb), nickel (Ni), copper (Cu), arsenic (As) and chromium (Cr), employing Total Reflection X-Ray Fluorescence Spectroscopy (TXRF) as an alternative technique to ICP-MS or ICP-OES commonly used for this type of analysis. TXRF was chosen due to its advantages, which include short analysis time, promptness, simultaneous multi-element analysis capability and minimum sample preparation, low purchase and operational cost. The proposed methodology was applied to a large number of electronic cigarette liquids commercially available, as well as their constituents, in order to evaluate their safety. TXRF may be a valuable tool for probing heavy metals in electronic cigarette refill liquids to serve for the protection of human health. Copyright © 2018 Elsevier Ltd. All rights reserved.

Evaluation of growth tree rings of Tipuana Tipu as biomonitoring of environmental pollution by synchrotron radiation total reflection X-ray fluorescence

International Nuclear Information System (INIS)

Moreira, Silvana; Geraldo, Simoni Michetti; Canteras, Felippe Benavente

2013-01-01

The bioindicators, plants or animals capable to present qualitative and/or quantitative answers, when exposed to pollutant substances. Trees record and incorporate in their log, developed year after year, the impressions of the environment, becoming possible the study of the different environmental changes, including contamination, that have occurred over the life of these trees. The selected species, Tipuana Tipu, of the Leguminosae family, is native of Argentina and Bolivia and was introduced in Brazil as an ornamental plant. It is one of the most common trees in the urban landscaping in Sao Paulo city. The present project has as main objective the determination of the content of potentially toxic elements in samples of growth the tree rings of Tipuana Tipu, previously dated, collected in strategically locations of Sao Paulo, using Synchrotron Radiation Total Reflection X-Ray Fluorescence. Samples were also collected in the Piracicaba (SP), local of little access and small flow traffic. The SR-TXRF analysis was carried out in the X-ray Fluorescence Beamline at the Brazilian Synchrotron Light Source Laboratory, located in Campinas city, Sao Paulo State, Brazil. Some trace elements present concentrations higher than considered as normal in some periods. In this paper the highest value for Pb was 123.54 μg.g -1 considered as threshold value was observed for the period 1998 to 2000 for University of Sao Paulo, Butanta site. For the same period excessive level was also observed for samples collected in Piracicaba city. In Sao Paulo city, sample collected in the campus of University of Sao Paulo (Butanta), showed the highest toxicity, with concentration above the tolerable limit for Ti, Cr and Cu. For the samples collected in Piracicaba city the concentrations of Cr, Ni, Cu, and Pb exceeding the toxicity limits. (author)

Evaluation of growth tree rings of Tipuana Tipu as biomonitoring of environmental pollution by synchrotron radiation total reflection X-ray fluorescence

Energy Technology Data Exchange (ETDEWEB)

Moreira, Silvana; Geraldo, Simoni Michetti; Canteras, Felippe Benavente, E-mail: silvana@fec.unicamp.br, E-mail: felippe.canteras@gmail.com [Universidade Estadual de Campinas (FEC/UNICAMP), Campinas, SP (Brazil). Dept. de Saneamento e Ambiente

2013-07-01

The bioindicators, plants or animals capable to present qualitative and/or quantitative answers, when exposed to pollutant substances. Trees record and incorporate in their log, developed year after year, the impressions of the environment, becoming possible the study of the different environmental changes, including contamination, that have occurred over the life of these trees. The selected species, Tipuana Tipu, of the Leguminosae family, is native of Argentina and Bolivia and was introduced in Brazil as an ornamental plant. It is one of the most common trees in the urban landscaping in Sao Paulo city. The present project has as main objective the determination of the content of potentially toxic elements in samples of growth the tree rings of Tipuana Tipu, previously dated, collected in strategically locations of Sao Paulo, using Synchrotron Radiation Total Reflection X-Ray Fluorescence. Samples were also collected in the Piracicaba (SP), local of little access and small flow traffic. The SR-TXRF analysis was carried out in the X-ray Fluorescence Beamline at the Brazilian Synchrotron Light Source Laboratory, located in Campinas city, Sao Paulo State, Brazil. Some trace elements present concentrations higher than considered as normal in some periods. In this paper the highest value for Pb was 123.54 μg.g{sup -1} considered as threshold value was observed for the period 1998 to 2000 for University of Sao Paulo, Butanta site. For the same period excessive level was also observed for samples collected in Piracicaba city. In Sao Paulo city, sample collected in the campus of University of Sao Paulo (Butanta), showed the highest toxicity, with concentration above the tolerable limit for Ti, Cr and Cu. For the samples collected in Piracicaba city the concentrations of Cr, Ni, Cu, and Pb exceeding the toxicity limits. (author)

CO 2 Capture Capacity and Swelling Measurements of Liquid-like Nanoparticle Organic Hybrid Materials via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

KAUST Repository

Park, Youngjune; Shin, Dolly; Jang, Young Nam; Park, Ah-Hyung Alissa

2012-01-01

attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy. Simultaneous measurements of CO 2 capture capacity and swelling behaviors of polyetheramine (Jeffamine M-2070) and its corresponding NOHMs (NOHM-I-PE2070) were reported

Imaging Early Steps of Sindbis Virus Infection by Total Internal Reflection Fluorescence Microscopy

Directory of Open Access Journals (Sweden)

Youling Gu

2011-01-01

Full Text Available Sindbis virus (SINV is an alphavirus that has a broad host range and has been widely used as a vector for recombinant gene transduction, DNA-based vaccine production, and oncolytic cancer therapy. The mechanism of SINV entry into host cells has yet to be fully understood. In this paper, we used single virus tracking under total internal reflection fluorescence microscopy (TIRFM to investigate SINV attachment to cell surface. Biotinylated viral particles were labeled with quantum dots, which retained viral viability and infectivity. By time-lapse imaging, we showed that the SINV exhibited a heterogeneous dynamics on the surface of the host cells. Analysis of SINV motility demonstrated a two-step attachment reaction. Moreover, dual color TIRFM of GFP-Rab5 and SINV suggested that the virus was targeted to the early endosomes after endocytosis. These findings demonstrate the utility of quantum dot labeling in studying the early steps and behavior of SINV infection.

Watch your step! A frustrated total internal reflection approach to forensic footwear imaging.

Science.gov (United States)

Needham, J A; Sharp, J S

2016-02-16

Forensic image retrieval and processing are vital tools in the fight against crime e.g. during fingerprint capture. However, despite recent advances in machine vision technology and image processing techniques (and contrary to the claims of popular fiction) forensic image retrieval is still widely being performed using outdated practices involving inkpads and paper. Ongoing changes in government policy, increasing crime rates and the reduction of forensic service budgets increasingly require that evidence be gathered and processed more rapidly and efficiently. A consequence of this is that new, low-cost imaging technologies are required to simultaneously increase the quality and throughput of the processing of evidence. This is particularly true in the burgeoning field of forensic footwear analysis, where images of shoe prints are being used to link individuals to crime scenes. Here we describe one such approach based upon frustrated total internal reflection imaging that can be used to acquire images of regions where shoes contact rigid surfaces.

Watch your step! A frustrated total internal reflection approach to forensic footwear imaging

Science.gov (United States)

Needham, J. A.; Sharp, J. S.

2016-02-01

Forensic image retrieval and processing are vital tools in the fight against crime e.g. during fingerprint capture. However, despite recent advances in machine vision technology and image processing techniques (and contrary to the claims of popular fiction) forensic image retrieval is still widely being performed using outdated practices involving inkpads and paper. Ongoing changes in government policy, increasing crime rates and the reduction of forensic service budgets increasingly require that evidence be gathered and processed more rapidly and efficiently. A consequence of this is that new, low-cost imaging technologies are required to simultaneously increase the quality and throughput of the processing of evidence. This is particularly true in the burgeoning field of forensic footwear analysis, where images of shoe prints are being used to link individuals to crime scenes. Here we describe one such approach based upon frustrated total internal reflection imaging that can be used to acquire images of regions where shoes contact rigid surfaces.

Attenuated total reflection UV spectroscopy for simultaneous analysis of alkali, sulphide and dissolved lignin in pulping liquors

International Nuclear Information System (INIS)

Chai, X.S.; Zhu, J.Y.; Luo, Q.; Li, J.

2003-01-01

This study experimentally demonstrated attenuated total reflection (ATR) ultraviolet (UV) spectroscopy for rapid and simultaneous determination of the concentrations of hydroxide, sulphide and dissolved lignin in kraft pulping liquors. A multivariate partial least squares fitting procedure (using commercially available software) was employed to obtain the species concentrations from the measured absorption spectra of the pulping liquors. Good agreements between ATR-UV measured species concentrations and those obtained by reference methods (titration for hydroxide and sulphide and conventional UV absorption for dissolved lignin) were achieved. (author)

A small-displacement sensor using total internal reflection theory and surface plasmon resonance technology for heterodyne interferometry.

Science.gov (United States)

Wang, Shinn-Fwu

2009-01-01

A small-displacement sensor based on total-internal reflection theory and surface plasmon resonance technology is proposed for use in heterodyne interferometry. A small displacement can be obtained simply by measuring the variation in phase difference between s- and p-polarization states with the small-displacement sensor. The theoretical displacement resolution of the small-displacement sensor can reach 0.45 nm. The sensor has some additional advantages, e.g., a simple optical setup, high resolution, high sensitivity and rapid measurement. Its feasibility is also demonstrated.

Hyperspectral Sensing for Turbid Water Quality Monitoring in Freshwater Rivers: Empirical Relationship between Reflectance and Turbidity and Total Solids

Directory of Open Access Journals (Sweden)

Jiunn-Lin Wu

2014-11-01

Full Text Available Total suspended solid (TSS is an important water quality parameter. This study was conducted to test the feasibility of the band combination of hyperspectral sensing for inland turbid water monitoring in Taiwan. The field spectral reflectance in the Wu river basin of Taiwan was measured with a spectroradiometer; the water samples were collected from the different sites of the Wu river basin and some water quality parameters were analyzed on the sites (in situ as well as brought to the laboratory for further analysis. To obtain the data set for this study, 160 in situ sample observations were carried out during campaigns from August to December, 2005. The water quality results were correlated with the reflectivity to determine the spectral characteristics and their relationship with turbidity and TSS. Furthermore, multiple-regression (MR and artificial neural network (ANN were used to model the transformation function between TSS concentration and turbidity levels of stream water, and the radiance measured by the spectroradiometer. The value of the turbidity and TSS correlation coefficient was 0.766, which implies that turbidity is significantly related to TSS in the Wu river basin. The results indicated that TSS and turbidity are positively correlated in a significant way across the entire spectrum, when TSS concentration and turbidity levels were under 800 mg·L−1 and 600 NTU, respectively. Optimal wavelengths for the measurements of TSS and turbidity are found in the 700 and 900 nm range, respectively. Based on the results, better accuracy was obtained only when the ranges of turbidity and TSS concentration were less than 800 mg·L−1 and less than 600 NTU, respectively and used rather than using whole dataset (R2 = 0.93 versus 0.88 for turbidity and R2 = 0.83 versus 0.58 for TSS. On the other hand, the ANN approach can improve the TSS retrieval using MR. The accuracy of TSS estimation applying ANN (R2 = 0.66 was better than with the MR

Hyperspectral sensing for turbid water quality monitoring in freshwater rivers: Empirical relationship between reflectance and turbidity and total solids.

Science.gov (United States)

Wu, Jiunn-Lin; Ho, Chung-Ru; Huang, Chia-Ching; Srivastav, Arun Lal; Tzeng, Jing-Hua; Lin, Yao-Tung

2014-11-28

Total suspended solid (TSS) is an important water quality parameter. This study was conducted to test the feasibility of the band combination of hyperspectral sensing for inland turbid water monitoring in Taiwan. The field spectral reflectance in the Wu river basin of Taiwan was measured with a spectroradiometer; the water samples were collected from the different sites of the Wu river basin and some water quality parameters were analyzed on the sites (in situ) as well as brought to the laboratory for further analysis. To obtain the data set for this study, 160 in situ sample observations were carried out during campaigns from August to December, 2005. The water quality results were correlated with the reflectivity to determine the spectral characteristics and their relationship with turbidity and TSS. Furthermore, multiple-regression (MR) and artificial neural network (ANN) were used to model the transformation function between TSS concentration and turbidity levels of stream water, and the radiance measured by the spectroradiometer. The value of the turbidity and TSS correlation coefficient was 0.766, which implies that turbidity is significantly related to TSS in the Wu river basin. The results indicated that TSS and turbidity are positively correlated in a significant way across the entire spectrum, when TSS concentration and turbidity levels were under 800 mg·L(-1) and 600 NTU, respectively. Optimal wavelengths for the measurements of TSS and turbidity are found in the 700 and 900 nm range, respectively. Based on the results, better accuracy was obtained only when the ranges of turbidity and TSS concentration were less than 800 mg·L(-1) and less than 600 NTU, respectively and used rather than using whole dataset (R(2) = 0.93 versus 0.88 for turbidity and R(2) = 0.83 versus 0.58 for TSS). On the other hand, the ANN approach can improve the TSS retrieval using MR. The accuracy of TSS estimation applying ANN (R(2) = 0.66) was better than with the MR approach (R

Application of micro-attenuated total reflectance Fourier transform infrared spectroscopy to ink examination in signatures written with ballpoint pen on questioned documents.

Science.gov (United States)

Nam, Yun Sik; Park, Jin Sook; Lee, Yeonhee; Lee, Kang-Bong

2014-05-01

Questioned documents examined in a forensic laboratory sometimes contain signatures written with ballpoint pen inks; these signatures were examined to assess the feasibility of micro-attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy as a forensic tool. Micro-ATR FTIR spectra for signatures written with 63 ballpoint pens available commercially in Korea were obtained and used to construct an FTIR spectral database. A library-searching program was utilized to identify the manufacturer, blend, and model of each black ballpoint pen ink based upon their FTIR peak intensities, positions, and patterns in the spectral database. This FTIR technique was also successfully used in determining the sequence of homogeneous line intersections from the crossing lines of two ballpoint pen signatures. We have demonstrated with a set of sample documents that micro-ATR FTIR is a viable nondestructive analytical method that can be used to identify the origin of the ballpoint pen ink used to mark signatures. © 2014 American Academy of Forensic Sciences.

Mineral elements and essential trace elements in blood of seals of the North Sea measured by total-reflection X-ray fluorescence analysis

International Nuclear Information System (INIS)

Griesel, S.; Mundry, R.; Kakuschke, A.; Fonfara, S.; Siebert, U.; Prange, A.

2006-01-01

Mineral and essential trace elements are involved in numerous physiological processes in mammals. Often, diseases are associated with an imbalance of the electrolyte homeostasis. In this study, the concentrations of mineral elements (P, S, K, Ca) and essential trace elements (Fe, Cu, Zn, Se, Rb, Sr) in whole blood of harbor seals (Phoca vitulina) were determined using total-reflection X-ray fluorescence spectrometry (TXRF). Samples from 81 free-ranging harbor seals from the North Sea and two captive seals were collected during 2003-2005. Reference ranges and element correlations for health status determination were derived for P, S, K, Ca, Fe, Cu, and Zn level in whole blood. Grouping the seals by age, gender and sample location the concentration levels of the elements were compared. The blood from two captive seals with signs of diseases and four free-ranging seals showed reduced element levels of P, S, and Ca and differences in element correlation of electrolytes were ascertained. Thus, simultaneous measurements of several elements in only 500 μL volumes of whole blood provide the possibility to obtain information on both, the electrolyte balance and the hydration status of the seals. The method could therefore serve as an additional biomonitoring tool for the health assessment

Determination of total mercury and methylmercury in biological samples by photochemical vapor generation

Energy Technology Data Exchange (ETDEWEB)

Vieira, Mariana A.; Ribeiro, Anderson S.; Curtius, Adilson J. [Universidade Federal de Santa Catarina, Departamento de Quimica, Florianopolis, SC (Brazil); Sturgeon, Ralph E. [National Research Council Canada, Institute for National Measurement Standards, Ottawa, ON (Canada)

2007-06-15

Cold vapor atomic absorption spectrometry (CV-AAS) based on photochemical reduction by exposure to UV radiation is described for the determination of methylmercury and total mercury in biological samples. Two approaches were investigated: (a) tissues were digested in either formic acid or tetramethylammonium hydroxide (TMAH), and total mercury was determined following reduction of both species by exposure of the solution to UV irradiation; (b) tissues were solubilized in TMAH, diluted to a final concentration of 0.125% m/v TMAH by addition of 10% v/v acetic acid and CH{sub 3}Hg{sup +} was selectively quantitated, or the initial digests were diluted to 0.125% m/v TMAH by addition of deionized water, adjusted to pH 0.3 by addition of HCl and CH{sub 3}Hg{sup +} was selectively quantitated. For each case, the optimum conditions for photochemical vapor generation (photo-CVG) were investigated. The photochemical reduction efficiency was estimated to be {proportional_to}95% by comparing the response with traditional SnCl{sub 2} chemical reduction. The method was validated by analysis of several biological Certified Reference Materials, DORM-1, DORM-2, DOLT-2 and DOLT-3, using calibration against aqueous solutions of Hg{sup 2+}; results showed good agreement with the certified values for total and methylmercury in all cases. Limits of detection of 6 ng/g for total mercury using formic acid, 8 ng/g for total mercury and 10 ng/g for methylmercury using TMAH were obtained. The proposed methodology is sensitive, simple and inexpensive, and promotes ''green'' chemistry. The potential for application to other sample types and analytes is evident. (orig.)

An active one-particle microrheometer: incorporating magnetic tweezers to total internal reflection microscopy.

Science.gov (United States)

Gong, Xiangjun; Hua, Li; Wu, Chi; Ngai, To

2013-03-01

We present a novel microrheometer by incorporating magnetic tweezers in the total internal reflection microscopy (TIRM) that enables measuring of viscoelastic properties of materials near solid surface. An evanescent wave generated by a solid∕liquid interface in the TIRM is used as the incident light source in the microrheometer. When a probe particle (of a few micrometers diameter) moves near the interface, it can interact with the evanescent field and reflect its position with respect to the interface by the scattered light intensity. The exponential distance dependence of the evanescent field, on the one hand, makes this technique extremely sensitive to small changes from z-fluctuations of the probe (with a resolution of several nanometers), and on the other, it does not require imaging of the probe with high lateral resolution. Another distinct advantage is the high sensitivity in determining the z position of the probe in the absence of any labeling. The incorporated magnetic tweezers enable us to effectively manipulate the distance of the embedded particle from the interface either by a constant or an oscillatory force. The force ramp is easy to implement through a coil current ramp. In this way, the local viscous and elastic properties of a given system under different confinements can therefore be measured by resolving the near-surface particle motion. To test the feasibility of applying this microrheology to soft materials, we measured the viscoelastic properties of sucrose and poly(ethylene glycol) solutions and compared the results to bulk rheometry. In addition, we applied this technique in monitoring the structure and properties of deformable microgel particles near the flat surface.

Influence of particle and surface quality on the vitrinite reflectance of dispersed organic matter: Comparative exercise using data from the qualifying system for reflectance analysis working group of ICCP

Science.gov (United States)

Borrego, A.G.; Araujo, C.V.; Balke, A.; Cardott, B.; Cook, A.C.; David, P.; Flores, D.; Hamor-Vido, M.; Hiltmann, W.; Kalkreuth, W.; Koch, J.; Kommeren, C.J.; Kus, J.; Ligouis, B.; Marques, M.; Mendonca, Filho J.G.; Misz, M.; Oliveira, L.; Pickel, W.; Reimer, K.; Ranasinghe, P.; Suarez-Ruiz, I.; Vieth, A.

2006-01-01

The development of a qualifying system for reflectance analysis has been the scope of a working group within the International Committee for Coal and Organic Petrology (ICCP) since 1999, when J. Koch presented a system to qualify vitrinite particles according to their size, proximity to bright components and homogeneity of the surface. After some years of work aimed at improving the classification system using photomicrographs, it was decided to run a round robin exercise on microscopy samples. The classification system tested consists of three qualifiers ranging from excellent to low quality vitrinites with an additional option for unsuitable vitrinites. This paper reports on the results obtained by 22 analysts who were asked to measure random reflectance readings on vitrinite particles assigning to each reading a qualifier. Four samples containing different organic matter types and a variety of vitrinite occurrences have been analysed. Results indicated that the reflectance of particles classified as excellent, good or poor compared to the total average reflectance did not show trends to be systematically lower or higher for the four samples analysed. The differences in reflectance between the qualifiers for any given sample were lower than the scatter of vitrinite reflectance among participants. Overall, satisfactory results were obtained in determining the reflectance of vitrinite in the four samples analysed. This was so for samples having abundant and easy to identify vitrinites (higher plant-derived organic matter) as well as for samples with scarce and difficult to identify particles (samples with dominant marine-derived organic matter). The highest discrepancies were found for the organic-rich oil shales where the selection of the vitrinite population to measure proved to be particularly difficult. Special instructions should be provided for the analysis of this sort of samples. The certainty of identification of the vitrinite associated with the vitrinite

Determination of solid surface composition by the X-ray fluorescence method under total external reflection with angular scanning

International Nuclear Information System (INIS)

Krasnolutskij, V.P.

2000-01-01

Possibilities of determination of composition of surface layers by X-ray fluorescence analysis under total reflection of incident radiation with angular scanning of a target are investigated. For the case of the GaAs target it is shown that the sensibility of this method is sufficient for a control of element composition in layer of thickness 1 nm. A simple method for solution of inverse task of analysis of a two component medium is considered [ru

Dynamical characteristics of an electromagnetic field under conditions of total reflection

Science.gov (United States)

Bekshaev, Aleksandr Ya

2018-04-01

The dynamical characteristics of electromagnetic fields include energy, momentum, angular momentum (spin) and helicity. We analyze their spatial distributions near the planar interface between two transparent and non-dispersive media, when the incident monochromatic plane wave with arbitrary polarization is totally reflected, and an evanescent wave is formed in the medium with lower optical density. Based on the recent arguments in favor of the Minkowski definition of the electromagnetic momentum in a material medium (Philbin 2011 Phys. Rev. A 83 013823; Philbin and Allanson 2012 86 055802; Bliokh et al 2017 Phys. Rev. Lett. 119 073901), we derive the explicit expressions for the dynamical characteristics in both media, with special attention to their behavior at the interface. In particular, the ‘extraordinary’ spin and momentum components orthogonal to the plane of incidence are described, and a canonical (spin-orbital) momentum decomposition is performed that contains no singular terms. The field energy, helicity, the spin momentum and orbital momentum components are everywhere regular but experience discontinuities at the interface; the spin components parallel to the interface appear to be continuous, which testifies to the consistency of the adopted Minkowski picture. The results supply a meaningful example of the electromagnetic momentum decomposition, with separation of spatial and polarization degrees of freedom, in inhomogeneous media, and can be used in engineering the structured fields designed for optical sorting, dispatching and micromanipulation.

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Eltayeb, M. A. H.; Mohammed, A. A.

2003-01-01

In the present work uranium content and total phosphorus were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba Mountains in Sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (Vi) is kept in solution as its carbonate complex. The ion exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of absorbance of the yellow uranium (Vi)-8-hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the total liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples from uro area, which contain 200 ppm uranium in average. (Author)

Quantitative surface topography determination by Nomarski reflection microscopy. 2: Microscope modification, calibration, and planar sample experiments

International Nuclear Information System (INIS)

Hartman, J.S.; Gordon, R.L.; Lessor, D.L.

1980-01-01

The application of reflective Nomarski differential interference contrast microscopy for the determination of quantitative sample topography data is presented. The discussion includes a review of key theoretical results presented previously plus the experimental implementation of the concepts using a commercial Momarski microscope. The experimental work included the modification and characterization of a commercial microscope to allow its use for obtaining quantitative sample topography data. System usage for the measurement of slopes on flat planar samples is also discussed. The discussion has been designed to provide the theoretical basis, a physical insight, and a cookbook procedure for implementation to allow these results to be of value to both those interested in the microscope theory and its practical usage in the metallography laboratory

Study on the relation between uranium content and total phosphorus in some sudanese phosphate ore samples

International Nuclear Information System (INIS)

Mohammed, A.A.; Eltayeb, M.A.H.

2003-01-01

In the present work uranium content and total phosphorous were determined in 30 phosphate ore samples collected from Kurun and Uro areas in Nuba mountains in sudan. Spectrophotometry technique was used for this purpose. Uranium analysis is based on the use of nitrogen (V) acid for leaching the rock, and treatment with ammonium carbonate solution, whereby uranium (VI) is kept in solution as its carbonate complex. The ion-exchange technique was used for the recovery of uranium. Uranium was eluted from the resin with 1 M hydrochloric acid. In the elute, uranium was determined spectrophotometrically by measurement of the absorbance of the yellow uranium (VI) - 8- hydroxyquinolate complex at λ 400 nm. The total phosphorus was measured as (P 2 O 5 %) by treatment of the leach liquor with ammonium molybdate solution. The absorbance of the blue complex was measured at λ 880 nm. The results show that a limited relation is existed between uranium content and total phosphorus in phosphate samples from Kurun area, which contain 58.8 ppm uranium in average, where there are no relation is existed in phosphate samples samples from Uro area, which contain 200 ppm uranium in average

Simple and rapid quantification of total carotenoids in lyophilized apricots (prunus armeniaca L.) by means of reflectance colorimetry and photoacoustic spectrometry spectroscopy

NARCIS (Netherlands)

Doka, O.; Ficzek, G.; Luterotti, S.; Bicanic, D.D.; Spruijt, R.B.; Buijnsters, J.; Vegvari, G.

2013-01-01

Photoacoustic spectroscopy (PAS) and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and

Study on the effects of sample selection on spectral reflectance reconstruction based on the algorithm of compressive sensing

International Nuclear Information System (INIS)

Zhang, Leihong; Liang, Dong

2016-01-01

In order to solve the problem that reconstruction efficiency and precision is not high, in this paper different samples are selected to reconstruct spectral reflectance, and a new kind of spectral reflectance reconstruction method based on the algorithm of compressive sensing is provided. Four different color numbers of matte color cards such as the ColorChecker Color Rendition Chart and Color Checker SG, the copperplate paper spot color card of Panton, and the Munsell colors card are chosen as training samples, the spectral image is reconstructed respectively by the algorithm of compressive sensing and pseudo-inverse and Wiener, and the results are compared. These methods of spectral reconstruction are evaluated by root mean square error and color difference accuracy. The experiments show that the cumulative contribution rate and color difference of the Munsell colors card are better than those of the other three numbers of color cards in the same conditions of reconstruction, and the accuracy of the spectral reconstruction will be affected by the training sample of different numbers of color cards. The key technology of reconstruction means that the uniformity and representation of the training sample selection has important significance upon reconstruction. In this paper, the influence of the sample selection on the spectral image reconstruction is studied. The precision of the spectral reconstruction based on the algorithm of compressive sensing is higher than that of the traditional algorithm of spectral reconstruction. By the MATLAB simulation results, it can be seen that the spectral reconstruction precision and efficiency are affected by the different color numbers of the training sample. (paper)

Controllable transmission and total reflection through an impedance-matched acoustic metasurface

KAUST Repository

Mei, Jun

2014-12-02

A general design paradigm for a novel type of acoustic metasurface is proposed by introducing periodically repeated supercells on a rigid thin plate, where each supercell contains multiple cut-through slits that are filled with materials possessing different refractive indices but the same impedance as that of the host medium. When the wavelength of the incident wave is smaller than the periodicity, the direction of the transmitted wave with nearly unity transmittance can be chosen by engineering the phase discontinuities along the transverse direction. When the wavelength is larger than the periodicity, even though the metasurface is impedance matched to the host medium, most of the incident energy is reflected back and the remaining portion is converted into a surface-bound mode. We show that both the transmitted wave control and the high reflection with the surface mode excitation can be interpreted by a unified analytic model based on mode-coupling theory. Our general design principle not only supplies the functionalities of reflection-type acoustic metasurfaces, but also exhibits unprecedented flexibility and efficiency in various domains of wave manipulation for possible applications in fields like refracting, collimating, focusing or absorbing wave energy.

[Hygienic evaluation of the total mutagenic activity of snow samples from Magnitogorsk].

Science.gov (United States)

Legostaeva, T B; Ingel', F I; Antipanova, N A; Iurchenko, V V; Iuretseva, N A; Kotliar, N N

2010-01-01

The paper gives the results of 4-year monitoring of the total mutagenic activity of snow samples from different Magnitogork areas in a test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster. An association was first found between the rate of DLM and the content of some chemical compounds in the ambient air and snow samples; moreover all the substances present in the samples, which had found genotoxic effects, showed a positive correlation with the rate of DLM. Furthermore, direct correlations were first established between the rate of DLM and the air pollution index and morbidity rates in 5-7-year-old children residing in the areas under study. The findings allow the test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster to be recommended due to its unique informative and prognostic value for monitoring ambient air pollution and for extensive use in the risk assessment system.

Total CMB analysis of streaker aerosol samples by PIXE, PIGE, beta- and optical-absorption analyses

International Nuclear Information System (INIS)

Annegarn, H.J.; Przybylowicz, W.J.

1993-01-01

Multielemental analyses of aerosol samples are widely used in air pollution receptor modelling. Specifically, the chemical mass balance (CMB) model has become a powerful tool in urban air quality studies. Input data required for the CMB includes not only the traditional X-ray fluorescence (and hence PIXE) detected elements, but also total mass, organic and inorganic carbon, and other light elements including Mg, Na and F. The circular streaker sampler, in combination with PIXE analysis, has developed into a powerful tool for obtaining time-resolved, multielemental aerosol data. However, application in CMB modelling has been limited by the absence of total mass and complementary light element data. This study reports on progress in using techniques complementary to PIXE to obtain additional data from circular streaker samples, maintaining the nondestructive, instrumental approach inherent in PIXE: Beta-gauging using a 147 Pm source for total mass; optical absorption for inorganic carbon; and PIGE to measure the lighter elements. (orig.)

Determinação não destrutiva do nitrogênio total em plantas por espectroscopia de reflectância difusa no infravermelho próximo Non-destructive determination of total nitrogen in plants by diffuse reflectance near infrared spectroscopy

Directory of Open Access Journals (Sweden)

Kássio M. G. Lima

2008-01-01

Full Text Available Diffuse reflectance near-infrared (DR-NIR spectroscopy associated with partial least squares (PLS multivariate calibration is proposed for a direct, non-destructive, determination of total nitrogen in wheat leaves. The procedure was developed for an Analytical Instrumental Analysis course, carried out at the Institute of Chemistry of the State University of Campinas. The DR-NIR results are in good agreement with those obtained by the Kjeldhal standard procedure, with a relative error of less than ± 3% and the method may be used for teaching purposes as well as for routine analysis.

Evaluation of retro-reflective coating performance by reflectance and perceived relative brightness measurements

International Nuclear Information System (INIS)

Luse, Kaiva; Pausus, Anete; Karitans, Varis; Ozolins, Maris; Tukisa, Madara

2011-01-01

Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.

Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS)

OpenAIRE

Butler, J.J.; Park, H.; Barnes, P.Y.; Early, E.A.; Eijk-Olij, C. van; Zoutman, A.E.; Buller-Leeuwen, S. van; Groote Schaarsberg, J.

2002-01-01

The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those instruments. To assess the ability of laboratories to provide accurate Ultra Violet (UV) diffuse BRDF measurements, a BRDF measurement comparison was initiated by the NASA Total Ozone Mapping Spectrom...

Accessible biometrics: A frustrated total internal reflection approach to imaging fingerprints.

Science.gov (United States)

Smith, Nathan D; Sharp, James S

2017-05-01

Fingerprints are widely used as a means of identifying persons of interest because of the highly individual nature of the spatial distribution and types of features (or minuta) found on the surface of a finger. This individuality has led to their wide application in the comparison of fingerprints found at crime scenes with those taken from known offenders and suspects in custody. However, despite recent advances in machine vision technology and image processing techniques, fingerprint evidence is still widely being collected using outdated practices involving ink and paper - a process that can be both time consuming and expensive. Reduction of forensic service budgets increasingly requires that evidence be gathered and processed more rapidly and efficiently. However, many of the existing digital fingerprint acquisition devices have proven too expensive to roll out on a large scale. As a result new, low-cost imaging technologies are required to increase the quality and throughput of the processing of fingerprint evidence. Here we describe an inexpensive approach to digital fingerprint acquisition that is based upon frustrated total internal reflection imaging. The quality and resolution of the images produced are shown to be as good as those currently acquired using ink and paper based methods. The same imaging technique is also shown to be capable of imaging powdered fingerprints that have been lifted from a crime scene using adhesive tape or gel lifters. Copyright © 2017 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.

Evaluation of retro-reflective coating performance by reflectance and perceived relative brightness measurements

Energy Technology Data Exchange (ETDEWEB)

Luse, Kaiva; Pausus, Anete; Karitans, Varis; Ozolins, Maris; Tukisa, Madara, E-mail: kaiva.luse@gmail.com [University of Latvia, Optometry and Vision Science Department, Kengaraga street 8, Riga LV-1063 (Latvia)

2011-06-23

Retro-reflective properties of six types and five different colors or retro-reflective materials were discussed in this paper. Reflectance optical indicatrix of samples was determined and compared to obtained psychophyisical data of perceived brightness of human observer. Microscopic structure of the retro-reflective active regions of RR's was studied. Statistically significant differences in reflectivity and brightness of various types and colors of RR's were found.

Total-reflection X-ray fluorescence: An alternative tool for the analysis of magnetic ferrofluids

Energy Technology Data Exchange (ETDEWEB)

Fernandez-Ruiz, R. [Servicio Interdepartamental de Investigacion (SIdI), Facultad de Ciencias, Universidad Autonoma de Madrid, Cantoblanco, E-28049, Madrid (Spain)], E-mail: ramon.fernandez@uam.es; Costo, R.; Morales, M.P.; Bomati-Miguel, O.; Veintemillas-Verdaguer, S. [Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049, Madrid (Spain)

2008-12-15

This work presents the first application of the total-reflection X-ray fluorescence (TXRF) to the compositional study of magnetic ferrofluids. With the aims of validating the best analytical conditions and also, limitations of the TXRF in the compositional study of these materials, an alternative empirical method, based in the use of angle-dependence TXRF (AD-TXRF) measurements, is proposed. Three kinds of ferromagnetic nanoparticles, with different morphologies, have been studied. The techniques of inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) have been used to validate the TXRF results. In contrast with the plasma techniques, the developed TXRF procedure need not of previous chemical acid digestion. Additionally, two procedures of magnetic nanoparticles synthesis, co-precipitation and laser-pyrolysis, have been checked for the contaminants trace metals Zn, Mn and Cr. It has been found that the method of laser-pyrolysis produces nanoparticles of higher purity.

Comparison of ultraviolet Bi-directional Reflectance Distribution Function (BRDF) measurements of diffusers used in the calibration of the Total Ozone Mapping Spectrometer (TOMS)

NARCIS (Netherlands)

Butler, J.J.; Park, H.; Barnes, P.Y.; Early, E.A.; Eijk-Olij, C. van; Zoutman, A.E.; Buller-Leeuwen, S. van; Groote Schaarsberg, J.

2002-01-01

The measurement and long-term monitoring of global total ozone by ultraviolet albedo measuring satellite instruments require accurate and precise determination of the Bi-directional Reflectance Distribution Function (BRDF) of laboratory-based diffusers used in the pre-launch calibration of those

Rapid, nondestructive estimation of surface polymer layer thickness using attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy and synthetic spectra derived from optical principles.

Science.gov (United States)

Weinstock, B André; Guiney, Linda M; Loose, Christopher

2012-11-01

We have developed a rapid, nondestructive analytical method that estimates the thickness of a surface polymer layer with high precision but unknown accuracy using a single attenuated total reflection Fourier transform infrared (ATR FT-IR) measurement. Because the method is rapid, nondestructive, and requires no sample preparation, it is ideal as a process analytical technique. Prior to implementation, the ATR FT-IR spectrum of the substrate layer pure component and the ATR FT-IR and real refractive index spectra of the surface layer pure component must be known. From these three input spectra a synthetic mid-infrared spectral matrix of surface layers 0 nm to 10,000 nm thick on substrate is created de novo. A minimum statistical distance match between a process sample's ATR FT-IR spectrum and the synthetic spectral matrix provides the thickness of that sample. We show that this method can be used to successfully estimate the thickness of polysulfobetaine surface modification, a hydrated polymeric surface layer covalently bonded onto a polyetherurethane substrate. A database of 1850 sample spectra was examined. Spectrochemical matrix-effect unknowns, such as the nonuniform and molecularly novel polysulfobetaine-polyetherurethane interface, were found to be minimal. A partial least squares regression analysis of the database spectra versus their thicknesses as calculated by the method described yielded an estimate of precision of ±52 nm.

Trace elemental analysis of leaching solutions of hijiki seaweeds by a portable total reflection X-ray fluorescence spectrometer

International Nuclear Information System (INIS)

Liu, Ying; Imashuku, Susumu; Kawai, Jun

2014-01-01

A portable total reflection X-ray fluorescence spectrometer (TXRF) was used to analyze leaching solutions of hijiki seaweeds. S, Cl, K, Ca, Ti, Fe, Ni, As and Br were detected in the solutions. Arsenic quantification results were compared to those from ICP-AES. The TXRF quantification results of arsenic were not significantly different from those of ICP-AES, as two-way analysis of variance (ANOVA) method was applied to the significance test. This kind of small and high sensitive TXRF spectrometer can be used in food quality and environmental pollution investigation. (author)

Effects of bleaching agents on human enamel light reflectance.

Science.gov (United States)

Markovic, Ljubisa; Fotouhi, Kasra; Lorenz, Heribert; Jordan, Rainer A; Gaengler, Peter; Zimmer, Stefan

2010-01-01

Tooth whitening has been associated with splitting-up chromogenic molecules by hydrogen peroxides. Though micromorphological alterations are well documented, little is known about optical changes as a function of shifting in wavelengths. Therefore, the aim of the current study was to measure reflectance changes after bleaching in vitro by using a spectrometer. Forty-eight enamel slabs (diameter = 5 mm) were prepared from the sound enamel of extracted human teeth that were: 1) fully impacted, 2) from juveniles ages 10 to 16 years, 3) from adults 35 to 45 years of age and 4) from seniors older than age 65. In all specimens, the baseline total reflectance measurement was performed with a computer-assisted spectrometer (Ocean Optics, Dunedin, FL, USA) within wavelengths (wl) from 430 nm to 800 nm. Four enamel samples of each age group were exposed to either 10% or 15% carbamide peroxide (Illuminé Home, Dentsply, Konstanz, Germany) or 35% hydrogen peroxide (Pola Office, SDI Limited, Victoria, Australia). After surface treatment, all slabs underwent total reflectance measurement again. Statistical analysis was calculated at wl 450, 500 and 750 nm using the Student's paired t-test and one-way variance analysis. Total reflectance significantly increased after bleaching at all enamel maturation stages, irrespective of the bleaching agent concentration, for wl 450 nm (blue) and 500 nm (green) with penamel from adults and seniors (pwhitening of the dental enamel works at different maturation stages, even in impacted teeth. This effect is irrespective of the bleaching protocol used and the bleaching agent concentration.

Controllable transmission and total reflection through an impedance-matched acoustic metasurface

KAUST Repository

Mei, Jun; Wu, Ying

2014-01-01

supplies the functionalities of reflection-type acoustic metasurfaces, but also exhibits unprecedented flexibility and efficiency in various domains of wave manipulation for possible applications in fields like refracting, collimating, focusing or absorbing

Effect of sample thickness on the extracted near-infrared bulk optical properties of Bacillus subtilis in liquid culture.

Science.gov (United States)

Dzhongova, Elitsa; Harwood, Colin R; Thennadil, Suresh N

2011-11-01

In order to determine the bulk optical properties of a Bacillus subtilis culture during growth phase we investigated the effect of sample thickness on measurements taken with different measurement configurations, namely total diffuse reflectance and total diffuse transmittance. The bulk optical properties were extracted by inverting the measurements using the radiative transfer theory. While the relationship between reflectance and biomass changes with sample thickness and the intensity (absorbance) levels vary significantly for both reflectance and transmittance measurements, the extracted optical properties show consistent behavior in terms of both the relationship with biomass and magnitude. This observation indicates the potential of bulk optical properties for building models that could be more easily transferable compared to those built using raw measurements.

Speciation of copper and zinc in size-fractionated atmospheric particulate matter using total reflection mode X-ray absorption near-edge structure spectrometry

International Nuclear Information System (INIS)

Osan, Janos; Meirer, Florian; Groma, Veronika; Toeroek, Szabina; Ingerle, Dieter; Streli, Christina; Pepponi, Giancarlo

2010-01-01

The health effects of aerosol depend on the size distribution and the chemical composition of the particles. Heavy metals of anthropogenic origin are bound to the fine aerosol fraction (PM 2.5 ). The composition and speciation of aerosol particles can be variable in time, due to the time-dependence of anthropogenic sources as well as meteorological conditions. Synchrotron-radiation total reflection X-ray fluorescence (SR-TXRF) provides very high sensitivity for characterization of atmospheric particulate matter. X-ray absorption near-edge structure (XANES) spectrometry in conjunction with TXRF detection can deliver speciation information on heavy metals in aerosol particles collected directly on the reflector surface. The suitability of TXRF-XANES for copper and zinc speciation in size-fractionated atmospheric particulate matter from a short sampling period is presented. For high size resolution analysis, atmospheric aerosol particles were collected at different urban and rural locations using a 7-stage May cascade impactor having adapted for sampling on Si wafers. The thin stripe geometry formed by the particulate matter deposited on the May-impactor plates is ideally suited to SR-TXRF. Capabilities of the combination of the May-impactor sampling and TXRF-XANES measurements at HASYLAB Beamline L to Cu and Zn speciation in size-fractionated atmospheric particulate matter are demonstrated. Information on Cu and Zn speciation could be performed for elemental concentrations as low as 140 pg/m 3 . The Cu and Zn speciation in the different size fraction was found to be very distinctive for samples of different origin. Zn and Cu chemical state typical for soils was detected only in the largest particles studied (2-4 μm fraction). The fine particles, however, contained the metals of interest in the sulfate and nitrate forms.

Iodide-assisted total lead measurement and determination of different lead fractions in drinking water samples.

Science.gov (United States)

Zhang, Yuanyuan; Ng, Ding-Quan; Lin, Yi-Pin

2012-07-01

Lead and its compounds are toxic and can harm human health, especially the intelligence development in children. Accurate measurement of total lead present in drinking water is crucial in determining the extent of lead contamination and human exposure due to drinking water consumption. The USEPA method for total lead measurement (no. 200.8) is often used to analyze lead levels in drinking water. However, in the presence of high concentration of the tetravalent lead corrosion product PbO(2), the USEPA method was not able to fully recover particulate lead due to incomplete dissolution of PbO(2) particles during strong acid digestion. In this study, a new procedure that integrates membrane separation, iodometric PbO(2) measurement, strong acid digestion and ICP-MS measurement was proposed and evaluated for accurate total lead measurement and quantification of different lead fractions including soluble Pb(2+), particulate Pb(II) carbonate and PbO(2) in drinking water samples. The proposed procedure was evaluated using drinking water reconstituted with spiked Pb(2+), spiked particulate Pb(II) carbonate and in situ formed or spiked PbO(2). Recovery tests showed that the proposed procedure and the USEPA method can achieve 93-112% and 86-103% recoveries respectively for samples containing low PbO(2) concentrations (0.018-0.076 mg Pb per L). For samples containing higher concentrations of PbO(2) (0.089-1.316 mg Pb per L), the USEPA method failed to meet the recovery requirement for total lead (85-115%) while the proposed method can achieve satisfactory recoveries (91-111%) and differentiate the soluble Pb(2+), particulate Pb(II) carbonate and PbO(2).

STUDY OF INK LAYER BY METHOD OF ATTENUATED TOTAL REFLECTANCE SPECTROSCOPY

Directory of Open Access Journals (Sweden)

D. G. Fatkhullina

2016-05-01

Full Text Available Subject of Research. Researchresults of thickness distribution of an ink layer smearedon a glass surface are presented. The orange ink which is used as a coloring pigment in writing instrument (highlighter is selectedasan object of study. Method. Researches were carried out by the method of attenuated total reflectance(ATR spectroscopy. The spectral setup fitted up on the basis of monochromator MDR-204 was usedin the experiment. The peculiarity of the measurement scheme is the applicationofhigh-resolution camera as a radiation detector and information storage as an images package. Researches allowed receivingexperimental data in the form of ink ATR spectra arrayfor studied areas of layer surface in a given spectral range. Main Results. The estimation of ink layer thickness was done, that gives the possibilityto visualize its distribution over the surface using three-dimensional modeling capabilities. The thickness of the ink layer is not more than 0.12 microns and arithmetic mean of the thickness is0.06 microns. The local areas are observed in an ink distribution, they have a maximum layer thickness (0.07-0.12 microns or areas with the ink thickness less then 0.03 microns. Variation of the ink layer thicknessbetween the local areas is smooth. Practical Relevance. The proposed measuring scheme, the sequence of registration and processing of experimental data can be used to studyink distribution within the thickness of a surface layer of other materials,for example, in analysis of signs performed by an ink on paper medium in order to identify them in such areas of science as forensic science andstudy of art.

Use of total-reflection x-ray fluorescence in search of a biomonitor for environmental pollution in Vietnam

International Nuclear Information System (INIS)

Boman, J.; Wagner, A.; Brauer, H.; Viet Binh, D.

2000-01-01

The concentration of trace elements in tissues of several animals collected in the Ha Nam province, about 25 km south of Hanoi, Vietnam, has been investigated using total-reflection x-ray fluorescence (TXRF). With this study we wanted to address whether any of the animals were possible candidates for being bio-monitors for the pollution situation in a selected area of Vietnam. We also aim to compare the measured trace element concentrations to those representative to other provinces in Vietnam as well as to other parts of the world. An extensive bio-diversity of animals exists in Vietnam, where many of them play an important economic role in the agricultural breeding and production. The accumulation process of trace elements is still not known for a large number of animals. The parts of the collected animals chosen for analysis were muscle tissue and liver. The specimens were dried under vacuum and kept frozen. Before the TXRF analysis, the solid and dried samples were digested in nitric acid. The analysis was made at the Department of Physics at Chalmers University of Technology and Goeteborg University, Sweden, where a TXRF spectrometer has been developed by the Environmental Physics group. The results show that there could be a large variation in the concentration of trace elements, not only between the different animals but also between tissue parts of the same animal. Obviously, when selecting an organism to be used as a bio-monitor, other factors than the mere concentration of trace elements must be considered. (author)

Application of linear discriminant analysis and Attenuated Total Reflectance Fourier Transform Infrared microspectroscopy for diagnosis of colon cancer.

Science.gov (United States)

Khanmohammadi, Mohammadreza; Bagheri Garmarudi, Amir; Samani, Simin; Ghasemi, Keyvan; Ashuri, Ahmad

2011-06-01

Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) microspectroscopy was applied for detection of colon cancer according to the spectral features of colon tissues. Supervised classification models can be trained to identify the tissue type based on the spectroscopic fingerprint. A total of 78 colon tissues were used in spectroscopy studies. Major spectral differences were observed in 1,740-900 cm(-1) spectral region. Several chemometric methods such as analysis of variance (ANOVA), cluster analysis (CA) and linear discriminate analysis (LDA) were applied for classification of IR spectra. Utilizing the chemometric techniques, clear and reproducible differences were observed between the spectra of normal and cancer cases, suggesting that infrared microspectroscopy in conjunction with spectral data processing would be useful for diagnostic classification. Using LDA technique, the spectra were classified into cancer and normal tissue classes with an accuracy of 95.8%. The sensitivity and specificity was 100 and 93.1%, respectively.

A fiberoptic reflection oximeter.

Science.gov (United States)

Landsman, M L; Knop, N; Kwant, G; Mook, G A; Zijlstra, W G

1978-03-20

A catheter tip oximeter is described consisting of a cardiac catheter containing optical fibers, and incandescent light source, a light detection unit and a processing unit. Half of the optical fibers guide the light to the blood at the tip of the catheter, the other half the backscattered (reflected) light to the detection unit. The detection unit contains a dichroic mirror, transmitting most of the light with lambda less than 800 nm and reflecting most of the light with lambda greater than 900 nm, thus splitting the light into two beams. These pass through interference filters with nominal wavelengths of 640 and 920 nm respectively, and are focused on silicium barrier layer photocells. The photocell signals are amplified and fed into a divider giving the ratio of measuring (R640) and compensating (R920) photocell output. The relationship between log R640/R920 and oxygen saturation is represented by a slightly curved line. The relation may be linearized by subtracting a constant voltage from the divided output before taking the logarithm. The slope of the calibration line is dependent on the total haemoglobin concentration. Nonetheless an average calibration line can be used between 70 and 100% oxygen saturation. For 78 measurements of pig blood samples in this range (haemoglobin concentration between 96 and 161 g.1(-1)), the standard deviation of the difference between the fiberoptic oximeter and a Radiometer OSM1 oxygen saturation meter was 1.9% saturation, for 152 samples over the entire saturation range the standard deviation of the difference was 3.1% saturation. The influence of the flow velocity of blood on the light reflection depends on wavelength as well as on oxygen saturation. Therefore, complete compensation for the flow effect is not possible by simple means.

Determination of total alpha activity index in samples of radioactive wastes

International Nuclear Information System (INIS)

Galicia C, F. J.

2015-01-01

This study aimed to develop a methodology of preparation and quantification of samples containing radionuclides beta and/or alpha emitters, to determine the rates of alpha and beta total activity of radioactive waste samples. For this, a device of planchettes preparer was designed, to assist the planchettes preparation in a controlled environment and free of corrosive vapors. Planchettes were prepared in three means: nitrate, carbonate and sulfate, to different mass thickness, natural uranium (alpha and beta emitter) and in case of Sr-90 (beta emitter pure) only in half nitrate; and these planchettes were quantified in an alpha/beta counter, in order to construct the self-absorption curves for alpha and beta particles. These curves are necessary to determine the rate of alpha-beta activity of any sample because they provide the self-absorption correction factor to be applied in calculating the index. Samples with U were prepared with the help of the device of planchettes preparer and subsequently were analyzed in the proportional counter Mpc-100 Pic brand. Samples with Sr-90 were prepared without the device to see if there was a different behavior with respect to obtaining mass thickness. Similarly they were calcined and carried out count in the Mpc-100. To perform the count, first the parameters of counter operating were determined: operating voltages for alpha and beta particles 630 and 1500 V respectively, a count routine was generated where the time and count type were adjusted, and counting efficiencies for alpha and beta particles, with the aid of calibration sources of 210 Po for alphas and 90 Sr for betas. According to the results, the counts per minute will decrease as increasing the mass thickness of the sample (self-absorption curve), adjusting this behavior to an exponential function in all cases studied. The minor self-absorption of alpha and beta particles in the case of U was obtained in sulfate medium. The self-absorption curves of Sr-90 follow the

Simple and Rapid Quantification of Total Carotenoids in Lyophilized Apricots (Prunus armeniaca L. by Means of Reflectance Colorimetry and Photoacoustic Spectroscopy

Directory of Open Access Journals (Sweden)

Gitta Ficzek

2013-01-01

Full Text Available Photoacoustic spectroscopy (PAS and reflectance colorimetry are suggested as new tools for the analysis of total carotenoids in lyophilized apricot powders. The data obtained by these two techniques from seven apricot cultivars were compared to those acquired by spectrophotometry and high-performance liquid chromatography (HPLC. Best correlations were found between the total carotenoid (TC content (obtained by VIS spectrophotometry: 1.2–3.4 mg per 100 g of fresh mass and colorimetric index a* (a* represents the redness of the investigated sample, as well as either argon-ion laser- or xenon-lamp-based PAS. In all three cases linear correlations were comparable. However, according to the sensitivity and precision data, expressed via limit of detection (LOD and measurement repeatability, the Xe-lamp-based PAS is a preferred approach, followed by colorimetric index a* and Ar-ion laser PAS. Both PAS methods exhibit practically the same Pearson's correlation coefficient (R=0.987 and R=0.991 values. Nevertheless, residual sum of squares (RSS and residual standard deviation of the linear regression (sy/x differ markedly. For Xe-lamp-based PAS these parameters were much lower than in the case of Ar-ion laser PAS. Likewise, analysis imprecision amounted to relative standard deviation (RSD of 1–3 % for Xe-lamp PAS and 2–6 % for Ar-ion laser PAS. On the other hand, as expected, the calibration sensitivity achieved for the PAS signal induced by an Ar-ion laser at 481 nm was substantially higher than that of a Xe-lamp at 470 nm. Nevertheless, according to much lower sy/x, the corresponding LOD for Xe-lamp PAS was still two times lower than that of Ar-ion-based laser PAS (0.59 vs. 1.10 mg per 100 g. Unlike this, Ar-ion laser PAS showed more favourable instrumental precision and standard error of the weighed mean when compared to the Xe-lamp PAS (0.1–0.6 and 0.1–0.3 % vs. 0.5–8.0 and 0.4–1.7 %, respectively. As far as colorimetric indices are

Multielement determination in river-water of Sepetiba Bay tributaries (Brazil) by total reflection X-ray fluorescence using synchrotron radiation

International Nuclear Information System (INIS)

Costa, A.C.M.; Castro, C.R.F.; Lopes, R.T.; Anjos, M.J.; Rio de Janeiro State Univ.

2006-01-01

Trace elements were determined in the surface waters of tributaries of the Sepetiba Bay, Brazil (Piraque, Ita, Sao Francisco, Guarda, Guandu Mirim, Vala do Sangue and Engenho Novo rivers) by total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). Eighteen trace elements could be determined in the dissolved and the suspended particulate phases: Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr and Pb. The elemental concentration values were compared to the values recommended by the Brazilian legislation. (author)

Attenuated total reflectance-FT-IR spectroscopy for gunshot residue analysis: potential for ammunition determination.

Science.gov (United States)

Bueno, Justin; Sikirzhytski, Vitali; Lednev, Igor K

2013-08-06

The ability to link a suspect to a particular shooting incident is a principal task for many forensic investigators. Here, we attempt to achieve this goal by analysis of gunshot residue (GSR) through the use of attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR) combined with statistical analysis. The firearm discharge process is analogous to a complex chemical process. Therefore, the products of this process (GSR) will vary based upon numerous factors, including the specific combination of the firearm and ammunition which was discharged. Differentiation of FT-IR data, collected from GSR particles originating from three different firearm-ammunition combinations (0.38 in., 0.40 in., and 9 mm calibers), was achieved using projection to latent structures discriminant analysis (PLS-DA). The technique was cross (leave-one-out), both internally and externally, validated. External validation was achieved via assignment (caliber identification) of unknown FT-IR spectra from unknown GSR particles. The results demonstrate great potential for ATR-FT-IR spectroscopic analysis of GSR for forensic purposes.

The study of genomic DNA adsorption and subsequent interactions using total internal reflection ellipsometry.

Science.gov (United States)

Nabok, Alexei; Tsargorodskaya, Anna; Davis, Frank; Higson, Séamus P J

2007-10-31

The adsorption of genomic DNA and subsequent interactions between adsorbed and solvated DNA was studied using a novel sensitive optical method of total internal reflection ellipsometry (TIRE), which combines spectroscopic ellipsometry with surface plasmon resonance (SPR). Single strands of DNA of two species of fish (herring and salmon) were electrostatically adsorbed on top of polyethylenimine films deposited upon gold coated glass slides. The ellipsometric spectra were recorded and data fitting utilized to extract optical parameters (thickness and refractive index) of adsorbed DNA layers. The further adsorption of single stranded DNA from an identical source, i.e. herring ss-DNA on herring ss-DNA or salmon ss-DNA on salmon ss-DNA, on the surface was observed to give rise to substantial film thickness increases at the surface of about 20-21 nm. Conversely adsorption of DNA from alternate species, i.e. salmon ss-DNA on herring ss-DNA or herring ss-DNA on salmon ss-DNA, yielded much smaller changes in thickness of 3-5 nm. AFM studies of the surface roughness of adsorbed layers were in line with the TIRE data.

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

Science.gov (United States)

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

1999-10-01

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

Reflecting on reflection in interprofessional education: implications for theory and practice.

Science.gov (United States)

Clark, Phillip G

2009-05-01

Interprofessional education (IPE) involves learning, and learning requires reflection. Educators need to "reflect more on reflection" if they are to be effective teachers in ensuring the learning outcomes essential for teamwork and interprofessional practice (IPP), including incorporating both theory and practice into the development of educational interventions. First, this discussion surveys the IPE-relevant literature on reflection, and then defines and refines the multidimensional concept of reflection as it relates to IPE in developing and implementing teamwork learning programs and experiences. Second, specific methods to promote reflection are presented and explored, including self-assessments, journaling, and written papers. Actual samples from student journals and assignments provide examples of the impacts of using these methods on participant reflection and learning. Finally, implications for an expanded understanding and application of reflection for IPE will be discussed, and recommendations made for educational practice and research in this area.

Quantification of SOC and Clay Content Using Visible Near-Infrared Reflectance–Mid-Infrared Reflectance Spectroscopy With Jack-Knifing Partial Least Squares Regression

DEFF Research Database (Denmark)

Peng, Yi; Knadel, Maria; Gislum, René

2014-01-01

A total of 125 soil samples were collected from a Danish field varying in soil texture from sandy to loamy. Visible near-infrared reflectance (Vis-NIR) and mid-infrared reflectance (MIR) spectroscopy combined with chemometric methods were used to predict soil organic carbon (SOC) and clay content...

Near-field reflection backscattering apertureless optical microscopy: Application to spectroscopy experiments on opaque samples, comparison between lock-in and digital photon counting detection techniques

International Nuclear Information System (INIS)

Diziain, S.; Bijeon, J.-L.; Adam, P.-M.; Lamy de la Chapelle, M.; Thomas, B.; Deturche, R.; Royer, P.

2007-01-01

An apertureless scanning near-field optical microscope (ASNOM) in reflection backscattering configuration is designed to conduct spectroscopic experiments on opaque samples constituted of latex beads. The ASNOM proposed takes advantage of the depth-discrimination properties of confocal microscopes to efficiently extract the near-field optical signal. Given their importance in a spectroscopic experiment, we systematically compare the lock-in and synchronous photon counting detection methods. Some results of Rayleigh's scattering in the near field of the test samples are used to illustrate the possibilities of this technique for reflection backscattering spectroscopy

Near-field reflection backscattering apertureless optical microscopy: Application to spectroscopy experiments on opaque samples, comparison between lock-in and digital photon counting detection techniques

Energy Technology Data Exchange (ETDEWEB)

Diziain, S. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Bijeon, J.-L. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France)]. E-mail: bijeon@utt.fr; Adam, P.-M. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Lamy de la Chapelle, M. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Thomas, B. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Deturche, R. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France); Royer, P. [Institut Charles Delaunay, CNRS FRE 2848, Laboratoire de Nanotechnologie et d' Instrumentation Optique, Universite de technologie de Troyes, 12 rue Marie Curie, BP 2060, 10010 Troyes cedex (France)

2007-01-15

An apertureless scanning near-field optical microscope (ASNOM) in reflection backscattering configuration is designed to conduct spectroscopic experiments on opaque samples constituted of latex beads. The ASNOM proposed takes advantage of the depth-discrimination properties of confocal microscopes to efficiently extract the near-field optical signal. Given their importance in a spectroscopic experiment, we systematically compare the lock-in and synchronous photon counting detection methods. Some results of Rayleigh's scattering in the near field of the test samples are used to illustrate the possibilities of this technique for reflection backscattering spectroscopy.

Cow-specific diet digestibility predictions based on near-infrared reflectance spectroscopy scans of faecal samples.

Science.gov (United States)

Mehtiö, T; Rinne, M; Nyholm, L; Mäntysaari, P; Sairanen, A; Mäntysaari, E A; Pitkänen, T; Lidauer, M H

2016-04-01

This study was designed to obtain information on prediction of diet digestibility from near-infrared reflectance spectroscopy (NIRS) scans of faecal spot samples from dairy cows at different stages of lactation and to develop a faecal sampling protocol. NIRS was used to predict diet organic matter digestibility (OMD) and indigestible neutral detergent fibre content (iNDF) from faecal samples, and dry matter digestibility (DMD) using iNDF in feed and faecal samples as an internal marker. Acid-insoluble ash (AIA) as an internal digestibility marker was used as a reference method to evaluate the reliability of NIRS predictions. Feed and composite faecal samples were collected from 44 cows at approximately 50, 150 and 250 days in milk (DIM). The estimated standard deviation for cow-specific organic matter digestibility analysed by AIA was 12.3 g/kg, which is small considering that the average was 724 g/kg. The phenotypic correlation between direct faecal OMD prediction by NIRS and OMD by AIA over the lactation was 0.51. The low repeatability and small variability estimates for direct OMD predictions by NIRS were not accurate enough to quantify small differences in OMD between cows. In contrast to OMD, the repeatability estimates for DMD by iNDF and especially for direct faecal iNDF predictions were 0.32 and 0.46, respectively, indicating that developing of NIRS predictions for cow-specific digestibility is possible. A data subset of 20 cows with daily individual faecal samples was used to develop an on-farm sampling protocol. Based on the assessment of correlations between individual sample combinations and composite samples as well as repeatability estimates for individual sample combinations, we found that collecting up to three individual samples yields a representative composite sample. Collection of samples from all the cows of a herd every third month might be a good choice, because it would yield a better accuracy. © 2015 Blackwell Verlag GmbH.

Artificial Neural Network for Total Laboratory Automation to Improve the Management of Sample Dilution.

Science.gov (United States)

Ialongo, Cristiano; Pieri, Massimo; Bernardini, Sergio

2017-02-01

Diluting a sample to obtain a measure within the analytical range is a common task in clinical laboratories. However, for urgent samples, it can cause delays in test reporting, which can put patients' safety at risk. The aim of this work is to show a simple artificial neural network that can be used to make it unnecessary to predilute a sample using the information available through the laboratory information system. Particularly, the Multilayer Perceptron neural network built on a data set of 16,106 cardiac troponin I test records produced a correct inference rate of 100% for samples not requiring predilution and 86.2% for those requiring predilution. With respect to the inference reliability, the most relevant inputs were the presence of a cardiac event or surgery and the result of the previous assay. Therefore, such an artificial neural network can be easily implemented into a total automation framework to sensibly reduce the turnaround time of critical orders delayed by the operation required to retrieve, dilute, and retest the sample.

Pesticides, selected elements, and other chemicals in adult total diet samples October 1979-September 1980

International Nuclear Information System (INIS)

Gartrell, M.J.; Craun, J.C.; Podrebarac, D.S.; Gunderson, E.L.

1985-01-01

The US Food and Drug Administration (FDA) conducts Total Diet Studies to determine the dietary intake of selected pesticides, industrial chemicals, and elements (including radionuclides). These studies involve the retail purchase and analysis of foods representative of the diets of infants, toddlers, and adults. The individual food items are separated into a number of food groups, each of which is analyzed as a composite. This report summarizes the results for adult Total Diet samples collected in 20 cities between October 1979 and September 1980. The average concentration, range of concentrations, and calculated average daily intake of each chemical found are presented by food group. The average daily intakes of the chemicals are similar to those found in the several preceding years and are within acceptable limits. The results for samples collected during the same period that represent the diets of infants and toddlers are reported separately

Heavy metal analysis in groundwater samples by SR-TXRF

International Nuclear Information System (INIS)

Moreira, Silvana; Ficaris, Maria; Vives, Ana Elisa S. de; Zucchi, Orgheda L.A.D.; Nascimento Filho, Virgilio Franco do Centro de Energia Nuclear na Agricultura , Piracicaba, SP . Lab. Instrumentacao Nuclear.; Brazil)

2005-01-01

In order to obtain information about levels of heavy metals in groundwater, analysis were carried out on samples from monitoring and supplying wells located in Campinas, Sao Paulo State, Southeastern Brazil. The analytical technique used was Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) and all the measurements were performed at Synchrotron Light Source Laboratory, using a white beam and a Si(Li) detector in total reflection condition. The determined elements were Al, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. The results were compared with the maximum allowed values (MPV) established by the Brazilian Health Department. The detection limits obtained varying from 0.10 up to 8 μg.L -1 were in agreement with the values presented by others analytical techniques. (author)

Heavy metal analysis in groundwater samples by SR-TXRF

Energy Technology Data Exchange (ETDEWEB)

Moreira, Silvana; Ficaris, Maria [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo. Dept. de Recursos Hidricos]. E-mail: silvana@fec.unicamp.br; Vives, Ana Elisa S. de [Universidade Metodista de Piracicaba (UNIMEP), Santa Barbara D' Oeste, SP (Brazil). Faculdade de Engenharia, Arquitetura e Urbanismo]. E-mail: aesvives@unimep.br; Zucchi, Orgheda L.A.D. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: olzucchi@fcfrp.usp.br; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. Instrumentacao Nuclear]. E-mail: virgilio@cena.usp.br

2005-07-01

In order to obtain information about levels of heavy metals in groundwater, analysis were carried out on samples from monitoring and supplying wells located in Campinas, Sao Paulo State, Southeastern Brazil. The analytical technique used was Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) and all the measurements were performed at Synchrotron Light Source Laboratory, using a white beam and a Si(Li) detector in total reflection condition. The determined elements were Al, Cr, Mn, Fe, Ni, Cu, Zn, Ba and Pb. The results were compared with the maximum allowed values (MPV) established by the Brazilian Health Department. The detection limits obtained varying from 0.10 up to 8 {mu}g.L{sup -1} were in agreement with the values presented by others analytical techniques. (author)

Occurrence and origin of carbohydrates in peat samples from a red mangrove environment as reflected by abundances of neutral monosaccharides

Science.gov (United States)

Moers, M. E. C.; Baas, M.; De Leeuw, J. W.; Boon, J. J.; Schenck, P. A.

1990-09-01

Acid hydrolysates of fractionated red mangrove peat samples and handpicked roots and rootlets of Rhizophora mangle (red mangrove) from Jewfish Key in the Florida Everglades were analysed for neutral monosaccharides. In the peat samples two major sources of carbohydrates could be determined: (1) vascular plant carbohydrates derived from Rhizophora mangle and (2) microbially derived carbohydrates. Significant correlations exist between the relative contributions of most neutral monosaccharides and the total carbohydrate concentration. The fine-grained peat fractions yielded low total neutral monosaccharides whose distributions indicate contributions of microbial carbohydrates. The coarse-grained peat samples yielded high total neutral monosaccharides with distributions indicating major contributions of vascular plant carbohydrates. It is estimated that a substantial part of the sugars analysed in the finegrained samples originates from microorganisms ([cyano] bacteria, algae).The absence of a trend in total neutral monosaccharide concentrations with depth suggests that microbial degradation is limited to the upper levels of the peat and that the microbial sugars determined at lower peat levels are derived from nonviable or dormant microorganisms. Results from factor analysis may suggest differences in microbial populations in the various peat samples.

Synchrotron radiation total reflection x-ray fluorescence analysis; of polymer coated silicon wafers

International Nuclear Information System (INIS)

Brehm, L.; Kregsamer, P.; Pianetta, P.

2000-01-01

It is well known that total reflection x-ray fluorescence (TXRF) provides an efficient method for analyzing trace metal contamination on silicon wafer surfaces. New polymeric materials used as interlayer dielectrics in microprocessors are applied to the surface of silicon wafers by a spin-coating process. Analysis of these polymer coated wafers present a new challenge for TXRF analysis. Polymer solutions are typically analyzed for bulk metal contamination prior to application on the wafer using inductively coupled plasma mass spectrometry (ICP-MS). Questions have arisen about how to relate results of surface contamination analysis (TXRF) of a polymer coated wafer to bulk trace analysis (ICP-MS) of the polymer solutions. Experiments were done to explore this issue using synchrotron radiation (SR) TXRF. Polymer solutions were spiked with several different concentrations of metals. These solutions were applied to silicon wafers using the normal spin-coating process. The polymer coated wafers were then measured using the SR-TXRF instrument set-up at the Stanford Synchrotron Radiation Laboratory (SSRL). Several methods of quantitation were evaluated. The best results were obtained by developing calibration curves (intensity versus ppb) using the spiked polymer coated wafers as standards. Conversion of SR-TXRF surface analysis results (atoms/cm 2 ) to a volume related concentration was also investigated. (author)

A comparison of the performance of a fundamental parameter method for analysis of total reflection X-ray fluorescence spectra and determination of trace elements, versus an empirical quantification procedure

Science.gov (United States)

W(egrzynek, Dariusz; Hołyńska, Barbara; Ostachowicz, Beata

1998-01-01

The performance has been compared of two different quantification methods — namely, the commonly used empirical quantification procedure and a fundamental parameter approach — for determination of the mass fractions of elements in particulate-like sample residues on a quartz reflector measured in the total reflection geometry. In the empirical quantification procedure, the spectrometer system needs to be calibrated with the use of samples containing known concentrations of the elements. On the basis of intensities of the X-ray peaks and the known concentration or mass fraction of an internal standard element, by using relative sensitivities of the spectrometer system the concentrations or mass fractions of the elements are calculated. The fundamental parameter approach does not require any calibration of the spectrometer system to be carried out. However, in order to account for an unknown mass per unit area of a sample and sample nonuniformity, an internal standard element is added. The concentrations/mass fractions of the elements to be determined are calculated during fitting a modelled X-ray spectrum to the measured one. The two quantification methods were applied to determine the mass fractions of elements in the cross-sections of a peat core, biological standard reference materials and to determine the concentrations of elements in samples prepared from an aqueous multi-element standard solution.

Total reflection X-ray fluorescence applied to the chemical elements analysis of the mate tea infusion (Ilex-paraguariensis); Fluorescencia de raios-X por reflexao total aplicada a analise de elementos quimicos em cha de erva-mate (Ilex-paraguariensis)

Energy Technology Data Exchange (ETDEWEB)

Lopes, Fabio; Appoloni, Carlos R. [Universidade Estadual de Londrina, PR (Brazil). Lab. de Fisica Nuclear Aplicada; Cunha, Richard M. da Silva e; Nascimento Filho, Virgilio Franco do [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear

2002-07-01

The purpose was to evaluate simultaneously the chemical element concentrations from K to Sr (19{<=}Z{<=}38) range in six samples of mate tea (Ilex paraguariensis) infusion, commercially available in Paraguay and South of Brazil. The chemical analysis of this beverage has a great nutritional importance for the native people of these areas, due to their large daily consumption. For the determination of these elements the dry-ashing and total reflection X-rays fluorescence (TXRF) were used. The methodology showed limits of detection among 81 ng.mL-1 for K to 10 ng.mL{sup -1} for Zn. Six infusion samples were prepared in triplicate, and the concentration was 3,8 to 10,2 {mu}g.mL{sup -1} for K, Ca and Mn, 0,21 to 1,07 {mu}g. mL{sup -1} for Fe and Zn and 0.03 to 0,17 {mu}g.mL{sup -1} for Ni, Cu, Br, Rb and Sr. The Mn and Ni concentrations are above the maximum permissible values for drinking water established by World Health Organization and Brazilian legislation (these organisms do not regulate the maximum permissible values for chemical elements in mate tea infusion). (author)

Rapid determination of carbohydrates, ash, and extractives contents of straw using attenuated total reflectance fourier transform mid-infrared spectroscopy.

Science.gov (United States)

Tamaki, Yukihiro; Mazza, Giuseppe

2011-06-22

Analysis of the chemical components of lignocellulosic biomass is essential to understanding its potential for utilization. Mid-infrared spectroscopy and partial least-squares regression were used for rapid measurement of the carbohydrate (total glycans; glucan; xylan; galactan; arabinan; mannan), ash, and extractives content of triticale and wheat straws. Calibration models for total glycans, glucan, and extractives showed good and excellent predictive performance on the basis of slope, r², RPD, and R/SEP criteria. The xylan model showed good and acceptable predictive performance. However, the ash model was evaluated as providing only approximate quantification and screening. The models for galactan, arabinan, and mannan indicated poor and insufficient prediction for application. Most models could predict both triticale and wheat straw samples with the same degree of accuracy. Mid-infrared spectroscopic techniques coupled with partial least-squares regression can be used for rapid prediction of total glycans, glucan, xylan, and extractives in triticale and wheat straw samples.

Quantification of protein based on single-molecule counting by total internal reflection fluorescence microscopy with adsorption equilibrium

International Nuclear Information System (INIS)

Wang Lei; Xu Guang; Shi Zhikun; Jiang Wei; Jin Wenrui

2007-01-01

We developed a sensitive single-molecule imaging method for quantification of protein by total internal reflection fluorescence microscopy with adsorption equilibrium. In this method, the adsorption equilibrium of protein was achieved between solution and glass substrate. Then, fluorescence images of protein molecules in a evanescent wave field were taken by a highly sensitive electron multiplying charge coupled device. Finally, the number of fluorescent spots corresponding to the protein molecules in the images was counted. Alexa Fluor 488-labeled goat anti-rat IgG(H + L) was chosen as the model protein. The spot number showed an excellent linear relationship with protein concentration. The concentration linear range was 5.4 x 10 -11 to 8.1 x 10 -10 mol L -1

Analysis of reflection-peak wavelengths of sampled fiber Bragg gratings with large chirp.

Science.gov (United States)

Zou, Xihua; Pan, Wei; Luo, Bin

2008-09-10

The reflection-peak wavelengths (RPWs) in the spectra of sampled fiber Bragg gratings with large chirp (SFBGs-LC) are theoretically investigated. Such RPWs are divided into two parts, the RPWs of equivalent uniform SFBGs (U-SFBGs) and the wavelength shift caused by the large chirp in the grating period (CGP). We propose a quasi-equivalent transform to deal with the CGP. That is, the CGP is transferred into quasi-equivalent phase shifts to directly derive the Fourier transform of the refractive index modulation. Then, in the case of both the direct and the inverse Talbot effect, the wavelength shift is obtained from the Fourier transform. Finally, the RPWs of SFBGs-LC can be achieved by combining the wavelength shift and the RPWs of equivalent U-SFBGs. Several simulations are shown to numerically confirm these predicted RPWs of SFBGs-LC.

Slow neutron total cross-section, transmission and reflection calculation for poly- and mono-NaCl and PbF2 crystals

Science.gov (United States)

Mansy, Muhammad S.; Adib, M.; Habib, N.; Bashter, I. I.; Morcos, H. N.; El-Mesiry, M. S.

2016-10-01

A detailed study about the calculation of total neutron cross-section, transmission and reflection from crystalline materials was performed. The developed computer code is approved to be sufficient for the required calculations, also an excellent agreement has been shown when comparing the code results with the other calculated and measured values. The optimal monochromator and filter parameters were discussed in terms of crystal orientation, mosaic spread, and thickness. Calculations show that 30 cm thick of PbF2 poly-crystal is an excellent cold neutron filter producing neutron wavelengths longer than 0.66 nm needed for the investigation of magnetic structure experiments. While mono-crystal filter PbF2 cut along its (1 1 1), having mosaic spread (η = 0.5°) and thickness 10 cm can only transmit thermal neutrons of the desired wavelengths and suppress epithermal and γ-rays forming unwanted background, when it is cooled to liquid nitrogen temperature. NaCl (2 0 0) and PbF2 (1 1 1) monochromator crystals having mosaic spread (η = 0.5°) and thickness 10 mm shows high neutron reflectivity for neutron wavelengths (λ = 0.114 nm and λ = 0.43 nm) when they used as a thermal and cold neutron monochromators respectively with very low contamination from higher order reflections.

Three-dimensional particle tracking in concave structures made by ultraviolet nanoimprint via total internal reflection fluorescence microscopy and refractive-index-matching method

Science.gov (United States)

Fujinami, Taku; Kigami, Hiroshi; Unno, Noriyuki; Taniguchi, Jun; Satake, Shin-ichi

2018-03-01

Total internal reflection fluorescence microscopy (TIRFM) is a promising method for measuring fluid flow close to a wall with nanoscale resolution in a process that is termed "multilayer nanoparticle image velocimetry" (MnPIV). TIRFM uses evanescent light that is generated on a substrate (typically a glass slide) by total internal reflection of light. Many researchers have previously studied x-y-z (3D) flows of water close to flat glass slides using MnPIV. On the other hand, a fluid flow close to a structured surface is also important. To measure flows of water near micro-patterns, we previously developed an MnPIV technique that uses a refractive-index-matching method. In previous study, the micropattern is made of a thermoplastic material with a refractive index that closely matches that of water. In this study, ultraviolet nanoimprint lithography was used for fabricating the appropriate micro-patterns because this technique can fabricate a pattern with a high resolution. As a result, we succeeded in performing MnPIV in water with a circular hole array pattern made by ultraviolet nanoimprint using a refractive-index-matching method. We believe that this technique will be helpful in elucidating fluid flows around microstructures.

Application of Terahertz Attenuated Total Reflection Spectroscopy to Detect Changes in the Physical Properties of Lactose during the Lubrication Process Required for Drug Formulation.

Science.gov (United States)

Dohi, Masafumi; Momose, Wataru; Yamashita, Kazunari; Hakomori, Tadashi; Sato, Shusaku; Noguchi, Shuji; Terada, Katsuhide

2017-02-01

Manufacturing the solid dosage form of an orally administered drug requires lubrication to enhance manufacturability, ensuring that critical quality attributes such as disintegration and dissolution of the drug product are maintained during manufacture. Here, to evaluate lubrication performance during manufacture, we used terahertz attenuated total reflection (THz-ATR) spectroscopy to detect differences in the physical characteristics of the lubricated powder. We applied a simple formulation prepared by blending granulated lactose as filler with magnesium stearate as lubricant. A flat tablet was prepared using the lubricated powder to acquire sharp THz-ATR absorption peaks of the samples. First, we investigated the effects of lubricant concentration and compression pressure on preparation of the tablet and then determined the effect of the pressure applied to samples in contact with the ATR prism on sample absorption amplitude. We focused on the differences in the magnitudes of spectra at the lactose-specific frequency. Second, we conducted the dynamic lubrication process using a 120-L mixer to investigate differences in the magnitudes of absorption corresponding to the lactose-specific frequency during lubrication. In both studies, enriching the lubricated powder with a higher concentration of magnesium stearate or prolonging blending time correlated with higher magnitudes of spectra at the lactose-specific frequency. Further, in the dynamic lubrication study, the wettability and disintegration time of the tablets were compared with the absorption spectra amplitudes at the lactose-specific frequency. We conclude that THz-ATR spectroscopy is useful for detecting differences in densities caused by a change in the physical properties of lactose during lubrication.

Rapid determination of free fatty acid content in waste deodorizer distillates using single bounce-attenuated total reflectance-FTIR spectroscopy.

Science.gov (United States)

Naz, Saba; Sherazi, Sayed Tufail Hussain; Talpur, Farah N; Mahesar, Sarfaraz A; Kara, Huseyin

2012-01-01

A simple, rapid, economical, and environmentally friendly analytical method was developed for the quantitative assessment of free fatty acids (FFAs) present in deodorizer distillates and crude oils by single bounce-attenuated total reflectance-FTIR spectroscopy. Partial least squares was applied for the calibration model based on the peak region of the carbonyl group (C=O) from 1726 to 1664 cm(-1) associated with the FFAs. The proposed method totally avoided the use of organic solvents or costly standards and could be applied easily in the oil processing industry. The accuracy of the method was checked by comparison to a conventional standard American Oil Chemists' Society (AOCS) titrimetric procedure, which provided good correlation (R = 0.99980), with an SD of +/- 0.05%. Therefore, the proposed method could be used as an alternate to the AOCS titrimetric method for the quantitative determination of FFAs especially in deodorizer distillates.

Preliminary investigations into macroscopic attenuated total reflection-fourier transform infrared imaging of intact spherical domains: spatial resolution and image distortion.

Science.gov (United States)

Everall, Neil J; Priestnall, Ian M; Clarke, Fiona; Jayes, Linda; Poulter, Graham; Coombs, David; George, Michael W

2009-03-01

This paper describes preliminary investigations into the spatial resolution of macro attenuated total reflection (ATR) Fourier transform infrared (FT-IR) imaging and the distortions that arise when imaging intact, convex domains, using spheres as an extreme example. The competing effects of shallow evanescent wave penetration and blurring due to finite spatial resolution meant that spheres within the range 20-140 microm all appeared to be approximately the same size ( approximately 30-35 microm) when imaged with a numerical aperture (NA) of approximately 0.2. A very simple model was developed that predicted this extreme insensitivity to particle size. On the basis of these studies, it is anticipated that ATR imaging at this NA will be insensitive to the size of intact highly convex objects. A higher numerical aperture device should give a better estimate of the size of small spheres, owing to superior spatial resolution, but large spheres should still appear undersized due to the shallow sampling depth. An estimate of the point spread function (PSF) was required in order to develop and apply the model. The PSF was measured by imaging a sharp interface; assuming an Airy profile, the PSF width (distance from central maximum to first minimum) was estimated to be approximately 20 and 30 microm for IR bands at 1600 and 1000 cm(-1), respectively. This work has two significant limitations. First, underestimation of domain size only arises when imaging intact convex objects; if surfaces are prepared that randomly and representatively section through domains, the images can be analyzed to calculate parameters such as domain size, area, and volume. Second, the model ignores reflection and refraction and assumes weak absorption; hence, the predicted intensity profiles are not expected to be accurate; they merely give a rough estimate of the apparent sphere size. Much further work is required to place the field of quantitative ATR-FT-IR imaging on a sound basis.

Worldwide distribution of Total Reflection X-ray Fluorescence instrumentation and its different fields of application: A survey

Energy Technology Data Exchange (ETDEWEB)

Klockenkämper, Reinhold, E-mail: reinhold.klockenkaemper@isas.de; Bohlen, Alex von

2014-09-01

A survey was carried out with users and manufacturers of Total Reflection X-ray Fluorescence instrumentation in order to demonstrate the worldwide distribution of TXRF equipment and the different fields of applications. In general, TXRF users come from universities and scientific institutes, from working places at synchrotron beam-lines, or laboratories in semiconductor fabs. TXRF instrumentation is distributed in more than 50 countries on six continents and is applied at about 200 institutes and laboratories. The number of running desktop instruments amounts to nearly 300 units. About 60 beamlines run working places dedicated to TXRF. About 300 floor-mounted instruments are estimated to be used in about 150 fabs of the semiconductor industry. In total, 13 different fields of applications could be registered statistically from three different aspects. - Highlights: • According to the survey world maps show the distribution of TXRF equipment. • Nearly 700 individual units are running actually in 57 countries of 6 continents. • Users work at 200 universities, 60 synchrotron-beamlines, and 150 semiconductor fabs. • 13 fields of applications (e.g. environmental, chemical) are evaluated statistically. • Manufacturers, conference members and authors lead to 3 different pie-charts.

The problem of 2,4,6-trichloroanisole in cork planks studied by attenuated total reflection infrared spectroscopy: proof of concept.

Science.gov (United States)

Garcia, Ana R; Lopes, Luís F; Brito de Barros, Ricardo; Ilharco, Laura M

2015-01-14

Attenuated total reflection infrared spectroscopy (ATR-IR) proved to be a promising detection technique for 2,4,6-trichloroanisole (TCA), which confers organoleptic defects to bottled alcoholic beverages, allowing the proposal of a criterion for cork plank acceptance when meant for stopper production. By analysis of a significant number of samples, it was proved that the presence of TCA, even in very low concentrations, imparts subtle changes to the cork spectra, namely, the growth of two new bands at ∼1417 (νC═C of TCA ring) and 1314 cm–1 (a shifted νCC of TCA) and an increase in the relative intensities of the bands at ∼1039 cm–1 (δCO of polysaccharides) and ∼813 cm–1 (τCH of suberin), the latter by overlapping with intense bands of TCA. These relative intensities were evaluated in comparison to a fingerprint of suberin (νasC–O–C), at 1161 cm–1. On the basis of those spectral variables, a multivariate statistics linear analysis (LDA) was performed to obtain a discriminant function that allows classifying the samples according to whether they contain or not TCA. The methodology proposed consists of a demanding acceptance criterion for cork planks destined for stopper production (with the guarantee of nonexistence of TCA) that results from combining the quantitative results with the absence of the two TCA correlated bands. ATR infrared spectroscopy is a nondestructive and easy to apply technique, both on cork planks and on stoppers, and has proven more restrictive than other techniques used in the cork industry that analyze the cleaning solutions. At the level of proof of concept, the method here proposed is appealing for high-value stopper applications.

Principles of neutron reflection

International Nuclear Information System (INIS)

Felcher, G.P.

1988-08-01

Neutron reflection is perhaps the most developed branch of slow neutrons optics, which in itself is a direct consequence of the undulatory nature of the neutron. After reviewing the basic types of interactions (nuclear and magnetic) between neutrons and matter, the formalism is introduced to calculate the reflectivity from a sample composed of stacked flat layers and, inversely, to calculate the stacking from reflectivity measurements. Finally, a brief survey of the applications of neutron reflection is given, both in technology and in fundamental research. 32 refs., 6 figs

Metallic attenuated total reflection infrared hollow fibers for robust optical transmission systems

Energy Technology Data Exchange (ETDEWEB)

Jing, Chengbin; Guo, Hong; Hu, Zhigao; Yang, Pingxiong [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); Chu, Junhao [Key Laboratory of Polar Materials and Devices, Ministry of Education, Department of Electronic Engineering, East China Normal University, 500 Dongchuan Road, Shanghai 200241 (China); National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, 500 Yu-tian Road, Shanghai 200083 (China); Liu, Aiyun [Department of Physics, Shanghai Normal University, 100 Gui Lin Road, Shanghai 200234 (China); Shi, Yiwei [School of Information Science and Engineering, Fudan University, 220 Handan Road, Shanghai 200433 (China)

2014-07-07

A durable metallic attenuated total reflection (ATR) hollow fiber (bore size: 1.45 mm, wall thickness: 50 μm) was designed and fabricated based on a nickel capillary tube and hexagonal germanium dioxide (GeO{sub 2}). The anomalous dispersion of the hexagonal GeO{sub 2} layer grown inside a nickel tube achieves low-loss light transmission at two peak-power wavelengths for CO{sub 2} laser devices (10.2 and 10.6 μm). An 11–28 W, 10.2 or 10.6 μm CO{sub 2} laser power was steadily delivered via a fiber elastically bent from 0° to 90° (radius: 45 cm) for over 40 min (transmission loss: 0.22 to 4.2 dB/m). Theoretically fitting the measured temperatures showed that front-end clipping caused greater thermal loading than the distributed mode absorption. The maximum external temperature of a nickel ATR fiber is much lower than that of a silica glass ATR fiber owing to their different heat dissipation abilities. The HE{sub 11} mode purity of the output beam profiles decreased from 90.3% to 44.7% as the bending angle increased from 0° to 90°. Large core sizes and wall roughnesses (scattering loss 0.04 dB/m) contributed to mode mixing and excess losses that were above the value predicted by the classical Marcatili and Schmeltzer equation (0.024–0.037 dB/m).

Static, Mixed-Array Total Evaporation for Improved Quantitation of Plutonium Minor Isotopes in Small Samples

Science.gov (United States)

Stanley, F. E.; Byerly, Benjamin L.; Thomas, Mariam R.; Spencer, Khalil J.

2016-06-01

Actinide isotope measurements are a critical signature capability in the modern nuclear forensics "toolbox", especially when interrogating anthropogenic constituents in real-world scenarios. Unfortunately, established methodologies, such as traditional total evaporation via thermal ionization mass spectrometry, struggle to confidently measure low abundance isotope ratios (evaporation techniques as a straightforward means of improving plutonium minor isotope measurements, which have been resistant to enhancement in recent years because of elevated radiologic concerns. Results are presented for small sample (~20 ng) applications involving a well-known plutonium isotope reference material, CRM-126a, and compared with traditional total evaporation methods.

Developing a composite weighted quality metric to reflect the total benefit conferred by a health plan.

Science.gov (United States)

Taskler, Glen B; Braithwaite, R Scott

2015-03-01

To improve individual health quality measures, which are associated with varying degrees of health benefit, and composite quality metrics, which weight individual measures identically. We developed a health-weighted composite quality measure reflecting the total health benefit conferred by a health plan annually, using preventive care as a test case. Using national disease prevalence, we simulated a hypothetical insurance panel of individuals aged 25 to 84 years. For each individual, we estimated the gain in life expectancy associated with 1 year of health system exposure to encourage adherence to major preventive care guidelines, controlling for patient characteristics (age, race, gender, comorbidity) and variation in individual adherence rates. This personalized gain in life expectancy was used to proxy for the amount of health benefit conferred by a health plan annually to its members, and formed weights in our health-weighted composite quality measure. We aggregated health benefits across the health insurance membership panel to analyze total health system performance. Our composite quality metric gave the highest weights to health plans that succeeded in implementing tobacco cessation and weight loss. One year of compliance with these goals was associated with 2 to 10 times as much health benefit as compliance with easier-to-follow preventive care services, such as mammography, aspirin, and antihypertensives. For example, for women aged 55 to 64 years, successful interventions to encourage weight loss were associated with 2.1 times the health benefit of blood pressure reduction and 3.9 times the health benefit of increasing adherence with screening mammography. A single health-weighted quality metric may inform measurement of total health system performance.

New light on ion channel imaging by total internal reflection fluorescence (TIRF) microscopy.

Science.gov (United States)

Yamamura, Hisao; Suzuki, Yoshiaki; Imaizumi, Yuji

2015-05-01

Ion channels play pivotal roles in a wide variety of cellular functions; therefore, their physiological characteristics, pharmacological responses, and molecular structures have been extensively investigated. However, the mobility of an ion channel itself in the cell membrane has not been examined in as much detail. A total internal reflection fluorescence (TIRF) microscope allows fluorophores to be imaged in a restricted region within an evanescent field of less than 200 nm from the interface of the coverslip and plasma membrane in living cells. Thus the TIRF microscope is useful for selectively visualizing the plasmalemmal surface and subplasmalemmal zone. In this review, we focused on a single-molecule analysis of the dynamic movement of ion channels in the plasma membrane using TIRF microscopy. We also described two single-molecule imaging techniques under TIRF microscopy: fluorescence resonance energy transfer (FRET) for the identification of molecules that interact with ion channels, and subunit counting for the determination of subunit stoichiometry in a functional channel. TIRF imaging can also be used to analyze spatiotemporal Ca(2+) events in the subplasmalemma. Single-molecule analyses of ion channels and localized Ca(2+) signals based on TIRF imaging provide beneficial pharmacological and physiological information concerning the functions of ion channels. Copyright © 2015 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Microwave-Assisted Sample Treatment in a Fully Automated Flow-Based Instrument: Oxidation of Reduced Technetium Species in the Analysis of Total Technetium-99 in Caustic Aged Nuclear Waste Samples

International Nuclear Information System (INIS)

Egorov, Oleg B.; O'Hara, Matthew J.; Grate, Jay W.

2004-01-01

An automated flow-based instrument for microwave-assisted treatment of liquid samples has been developed and characterized. The instrument utilizes a flow-through reaction vessel design that facilitates the addition of multiple reagents during sample treatment, removal of the gaseous reaction products, and enables quantitative removal of liquids from the reaction vessel for carryover-free operations. Matrix modification and speciation control chemistries that are required for the radiochemical determination of total 99Tc in caustic aged nuclear waste samples have been investigated. A rapid and quantitative oxidation procedure using peroxydisulfate in acidic solution was developed to convert reduced technetium species to pertechnetate in samples with high content of reducing organics. The effectiveness of the automated sample treatment procedures has been validated in the radiochemical analysis of total 99Tc in caustic aged nuclear waste matrixes from the Hanford site

Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy; Determinacion de plomo en esmaltado de barro por Fluorescencia de rayos X en reflexion total y Microscopia Electronica de Barrido

Energy Technology Data Exchange (ETDEWEB)

Zarazua O, G.; Carapia M, L. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

2000-07-01

This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

Science.gov (United States)

Révész, Kinga M.; Doctor, Daniel H.

2014-01-01

The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

Determination of ultra trace contaminants on silicon wafer surfaces using total-reflection X-ray fluorescence TXRF 'state-of-the-art'

Science.gov (United States)

Pahlke, S.; Fabry, L.; Kotz, L.; Mantler, C.; Ehmann, T.

2001-11-01

In a well balanced system of highly motivated, well trained personnel and automated equipment, pure reagents and bulk media, cleanrooms and integrated data management, total-reflection X-ray fluorescence (TXRF) can and must contribute to quality assurance and process stability, support and canalize creative engineering by continuous learning about materials and processes. TXRF has the advantage of controlled one-point calibration, a linear dynamic range of three orders of magnitude, high grade of automation in operation and data management, high up-time, and a simple control of data plausibility.

Determination of total organic phosphorus in samples of mineral soils

Directory of Open Access Journals (Sweden)

Armi Kaila

1962-01-01

Full Text Available In this paper some observations on the estimation of organic phosphorus in mineral soils are reported. The fact is emphasized that the accuracy of all the methods available is relatively poor. Usually, there are no reasons to pay attention to differences less than about 20 ppm. of organic P. Analyses performed on 345 samples of Finnish mineral soils by the extraction method of MEHTA et. al. (10 and by a simple procedure adopted by the author (successive extractions with 4 N H2SO4 and 0.5 N NaOH at room temperature in the ratio of 1 to 100 gave, on the average, equal results. It seemed to be likely that the MEHTA method removed the organic phosphorus more completely than did the less vigorous method, but in the former the partial hydrolysis of organic phosphorus compounds tends to be higher than in the latter. An attempt was made to find out whether the differences between the respective values for organic phosphorus obtained by an ignition method and the simple extraction method could be connected with any characteristics of the soil. No correlation or only a low correlation coefficient could be calculated between the difference in the results of these two methods and e. g. the pH-value, the content of clay, organic carbon, aluminium and iron soluble in Tamm’s acid oxalate, the indicator of the phosphate sorption capacity, or the »Fe-bound» inorganic phosphorus, respectively. The absolute difference tended to increase with an increase in the content of organic phosphorus. For the 250 samples of surface soils analyzed, the ignition method gave values which were, on the average, about 50 ppm. higher than the results obtained by the extraction procedure. The corresponding difference for the 120 samples from deeper layers was about 20 ppm of organic P. The author recommends, for the present, the determination of the total soil organic phosphorus as an average of the results obtained by the ignition method and the extraction method.

Quantitative determination of polyphosphate in sediments using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and partial least squares regression.

Science.gov (United States)

Khoshmanesh, Aazam; Cook, Perran L M; Wood, Bayden R

2012-08-21

Phosphorus (P) is a major cause of eutrophication and subsequent loss of water quality in freshwater ecosystems. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. Despite the broad relevance of polyphosphate (Poly-P) in bioremediation and P release processes in the environment, its quantification is not yet well developed for sediment samples. Current methods possess significant disadvantages because of the difficulties associated with using a single extractant to extract a specific P compound without altering others. A fast and reliable method to estimate the quantitative contribution of microorganisms to sediment P release processes is needed, especially when an excessive P accumulation in the form of polyphosphate (Poly-P) occurs. Development of novel approaches for application of emerging spectroscopic techniques to complex environmental matrices such as sediments significantly contributes to the speciation models of P mobilization, biogeochemical nutrient cycling and development of nutrient models. In this study, for the first time Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy in combination with partial least squares (PLS) was used to quantify Poly-P in sediments. To reduce the high absorption matrix components in sediments such as silica, a physical extraction method was developed to separate sediment biological materials from abiotic particles. The aim was to achieve optimal separation of the biological materials from sediment abiotic particles with minimum chemical change in the sample matrix prior to ATR-FTIR analysis. Using a calibration set of 60 samples for the PLS prediction models in the Poly-P concentration range of 0-1 mg g(-1) d.w. (dry weight of sediment) (R(2) = 0.984 and root mean square error of prediction RMSEP = 0.041 at Factor-1) Poly-P could be detected at less than 50 μg g(-l) d.w. Using this technique, there is no solvent extraction or chemical

On Practical Sampling of Bidirectional Reflectance

DEFF Research Database (Denmark)

Nielsen, Jannik Boll

for reconstructing full and accurate BRDFs from only a few measurements is presented. It is here demonstrated that with as little as 20 point-samples, a BRDF can accurately be reconstructed. Furthermore utilising the field of view of a camera, this may be reduced to as little as two images. With this, the thesis...

Quantifying the Assembly of Multicomponent Molecular Machines by Single-Molecule Total Internal Reflection Fluorescence Microscopy.

Science.gov (United States)

Boehm, E M; Subramanyam, S; Ghoneim, M; Washington, M Todd; Spies, M

2016-01-01

Large, dynamic macromolecular complexes play essential roles in many cellular processes. Knowing how the components of these complexes associate with one another and undergo structural rearrangements is critical to understanding how they function. Single-molecule total internal reflection fluorescence (TIRF) microscopy is a powerful approach for addressing these fundamental issues. In this article, we first discuss single-molecule TIRF microscopes and strategies to immobilize and fluorescently label macromolecules. We then review the use of single-molecule TIRF microscopy to study the formation of binary macromolecular complexes using one-color imaging and inhibitors. We conclude with a discussion of the use of TIRF microscopy to examine the formation of higher-order (i.e., ternary) complexes using multicolor setups. The focus throughout this article is on experimental design, controls, data acquisition, and data analysis. We hope that single-molecule TIRF microscopy, which has largely been the province of specialists, will soon become as common in the tool box of biophysicists and biochemists as structural approaches have become today. © 2016 Elsevier Inc. All rights reserved.

Tailored plasmon-induced transparency in attenuated total reflection response in a metal-insulator-metal structure.

Science.gov (United States)

Matsunaga, Kouki; Hirai, Yusuke; Neo, Yoichiro; Matsumoto, Takahiro; Tomita, Makoto

2017-12-19

We demonstrated tailored plasmon-induced transparency (PIT) in a metal (Au)-insulator (SiO 2 )-metal (Ag) (MIM) structure, where the Fano interference between the MIM waveguide mode and the surface plasmon polariton (SPP) resonance mode induced a transparency window in an otherwise opaque wavenumber (k) region. A series of structures with different thicknesses of the Ag layer were prepared and the attenuated total reflection (ATR) response was examined. The height and width of the transparency window, as well as the relevant k-domain dispersion, were controlled by adjusting the Ag layer thickness. To confirm the dependency of PIT on Ag layer thickness, we performed numerical calculations to determine the electric field amplitude inside the layers. The steep k-domain dispersion in the transparency window is capable of creating a lateral beam shift known as the Goos-Hänchen shift, for optical device and sensor applications. We also discuss the Fano interference profiles in a ω - k two-dimensional domain on the basis of Akaike information criteria.

Diffuse reflectance infrared Fourier-Transform spectra of selected organic compounds

Energy Technology Data Exchange (ETDEWEB)

Harmon, S.H.; Caton, J.E.

1982-05-01

Diffuse reflectance infrared spectra of a variety of different organic compounds have been determined. Profiles of the spectra along with the location and relative intensity of the principal bands have been included for each compound studied. In addition both diffuse reflectance and transmittance infrared spectra were obtained for the same samples, and the spectral results were compared. Although some minor variations are observed between a diffuse reflectance spectrum and the corresponding transmittance spectrum, the diffuse reflectance is quite useful and may be a superior technique for the study of many samples because it possesses an inherently higher signal-to-noise response, requires less sample preparation and allows a very wide range of samples (solids, liquids of low volatility, neat sample, or sample diluted in a reflecting medium) to be studied under very similar conditions.

Infrared reflection properties and modelling of in situ reflection measurements on plasma-facing materials in Tore Supra

International Nuclear Information System (INIS)

Reichle, R; Desgranges, C; Faisse, F; Pocheau, C; Lasserre, J-P; Oelhoffen, F; Eupherte, L; Todeschini, M

2009-01-01

Tore Supra has-like ITER-reflecting internal surfaces, which can perturb the machine protection systems based on infrared (IR) thermography. To ameliorate this situation, we have measured and modelled in the 3-5 μm wavelength range the bi-directional reflection distribution function (BRDF) of wall material samples from Tore Supra and conducted in situ reflection measurements and simulated them with the CEA COSMOS code. BRDF results are presented for B 4 C and carbon fibre composite (CFC) tiles. The hemispherical integrated reflection ranges from 0.12 for the B 4 C sample to 0.39 for a CFC tile from the limiter erosion zone. In situ measurements of the IR reflection of a blackbody source off an ICRH and an LHCD antenna of Tore Supra are well reproduced by the simulation.

Infrared reflection properties and modelling of in situ reflection measurements on plasma-facing materials in Tore Supra

Energy Technology Data Exchange (ETDEWEB)

Reichle, R; Desgranges, C; Faisse, F; Pocheau, C [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Lasserre, J-P; Oelhoffen, F; Eupherte, L; Todeschini, M [CEA, DAM, CESTA, F-33114 Le Barp (France)

2009-12-15

Tore Supra has-like ITER-reflecting internal surfaces, which can perturb the machine protection systems based on infrared (IR) thermography. To ameliorate this situation, we have measured and modelled in the 3-5 {mu}m wavelength range the bi-directional reflection distribution function (BRDF) of wall material samples from Tore Supra and conducted in situ reflection measurements and simulated them with the CEA COSMOS code. BRDF results are presented for B{sub 4}C and carbon fibre composite (CFC) tiles. The hemispherical integrated reflection ranges from 0.12 for the B{sub 4}C sample to 0.39 for a CFC tile from the limiter erosion zone. In situ measurements of the IR reflection of a blackbody source off an ICRH and an LHCD antenna of Tore Supra are well reproduced by the simulation.

Application of laboratory and portable attenuated total reflectance infrared spectroscopic approaches for rapid quantification of alpaca serum immunoglobulin G.

Directory of Open Access Journals (Sweden)

Ibrahim Elsohaby

Full Text Available The objective of this study was to develop and compare the performance of laboratory grade and portable attenuated total reflectance infrared (ATR-IR spectroscopic approaches in combination with partial least squares regression (PLSR for the rapid quantification of alpaca serum IgG concentration, and the identification of low IgG (<1000 mg/dL, which is consistent with the diagnosis of failure of transfer of passive immunity (FTPI in neonates. Serum samples (n = 175 collected from privately owned, healthy alpacas were tested by the reference method of radial immunodiffusion (RID assay, and laboratory grade and portable ATR-IR spectrometers. Various pre-processing strategies were applied to the ATR-IR spectra that were linked to corresponding RID-IgG concentrations, and then randomly split into two sets: calibration (training and test sets. PLSR was applied to the calibration set and calibration models were developed, and the test set was used to assess the accuracy of the analytical method. For the test set, the Pearson correlation coefficients between the IgG measured by RID and predicted by both laboratory grade and portable ATR-IR spectrometers was 0.91. The average differences between reference serum IgG concentrations and the two IR-based methods were 120.5 mg/dL and 71 mg/dL for the laboratory and portable ATR-IR-based assays, respectively. Adopting an IgG concentration <1000 mg/dL as the cut-point for FTPI cases, the sensitivity, specificity, and accuracy for identifying serum samples below this cut point by laboratory ATR-IR assay were 86, 100 and 98%, respectively (within the entire data set. Corresponding values for the portable ATR-IR assay were 95, 99 and 99%, respectively. These results suggest that the two different ATR-IR assays performed similarly for rapid qualitative evaluation of alpaca serum IgG and for diagnosis of IgG <1000 mg/dL, the portable ATR-IR spectrometer performed slightly better, and provides more flexibility for

Evaluation of water and sediment of the Graminha and Aguas da Serra streams in the city of Limeira (Sp-Brazil) by Synchrotron Radiation Total Reflection X-ray Fluorescence

Energy Technology Data Exchange (ETDEWEB)

Moreira, Silvana [University of Campinas, School of Civil Engineering, Architecture and Urban Design, P. O. Box 602, Zip Code 13083-852, Campinas, SP (Brazil)], E-mail: silvana@fec.unicamp.br; Fazza, Elizete Vieira [University of Campinas, School of Civil Engineering, Architecture and Urban Design, P. O. Box 602, Zip Code 13083-852, Campinas, SP (Brazil)], E-mail: fazzaelizete@yahoo.com

2008-12-15

The city of Limeira is located in the state of Sao Paulo, Brazil and has the second largest economy and demographic growth of the state. It comprises an expressive economy with industries in several productive sectors. The source of the Graminha and Aguas da Serra streams is located within the Limeira urban zone. The streams cross part of the rural zone and unite by draining into the Piracicaba River. It is possible that these basins suffer or have already suffered the impacts of environmental pollution caused by anthropogenic factors. Since the city has galvanization industries for the production of precious and semi-precious jewels as well as imitation jewelry, the concentration descriptions and interpretations of heavy metals in waters and sediments indicate anthropogenic influence and the dumping of these compounds into the Piracicaba River. The Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) was used for determining the metals. All measurements were performed using a white beam of synchrotron radiation for excitation and a Ge hyperpure detector. Detection limits for water samples were 0.04 {mu}g L{sup -1} and in sediment samples 0.03 {mu}g g{sup -1} for Cu and Zn elements. In the water samples, concentrations higher than permissible as established by the Brazilian legislation (CONAMA) for Al, Fe, Zn, Cr, Ni, Cu and Pb, were observed. For sediment samples, values higher than quality reference values defined by the Brazilian legislation (CETESB) were verified for Cr, Zn, Cu, Ni and Pb.

Evaluation of water and sediment of the Graminha and Aguas da Serra streams in the city of Limeira (Sp-Brazil) by Synchrotron Radiation Total Reflection X-ray Fluorescence

International Nuclear Information System (INIS)

Moreira, Silvana; Fazza, Elizete Vieira

2008-01-01

The city of Limeira is located in the state of Sao Paulo, Brazil and has the second largest economy and demographic growth of the state. It comprises an expressive economy with industries in several productive sectors. The source of the Graminha and Aguas da Serra streams is located within the Limeira urban zone. The streams cross part of the rural zone and unite by draining into the Piracicaba River. It is possible that these basins suffer or have already suffered the impacts of environmental pollution caused by anthropogenic factors. Since the city has galvanization industries for the production of precious and semi-precious jewels as well as imitation jewelry, the concentration descriptions and interpretations of heavy metals in waters and sediments indicate anthropogenic influence and the dumping of these compounds into the Piracicaba River. The Synchrotron Radiation Total Reflection X-Ray Fluorescence (SR-TXRF) was used for determining the metals. All measurements were performed using a white beam of synchrotron radiation for excitation and a Ge hyperpure detector. Detection limits for water samples were 0.04 μg L -1 and in sediment samples 0.03 μg g -1 for Cu and Zn elements. In the water samples, concentrations higher than permissible as established by the Brazilian legislation (CONAMA) for Al, Fe, Zn, Cr, Ni, Cu and Pb, were observed. For sediment samples, values higher than quality reference values defined by the Brazilian legislation (CETESB) were verified for Cr, Zn, Cu, Ni and Pb

Electrochemical sensing of total antioxidant capacity and polyphenol content in wine samples using amperometry online-coupled with microdialysis.

Science.gov (United States)

Jakubec, Petr; Bancirova, Martina; Halouzka, Vladimir; Lojek, Antonin; Ciz, Milan; Denev, Petko; Cibicek, Norbert; Vacek, Jan; Vostalova, Jitka; Ulrichova, Jitka; Hrbac, Jan

2012-08-15

This work describes the method for total antioxidant capacity (TAC) and/or total content of phenolics (TCP) analysis in wines using microdialysis online-coupled with amperometric detection using a carbon microfiber working electrode. The system was tested on 10 selected wine samples, and the results were compared with total reactive antioxidant potential (TRAP), oxygen radical absorbance capacity (ORAC), and chemiluminescent determination of total antioxidant capacity (CL-TAC) methods using Trolox and catechin as standards. Microdialysis online-coupled with amperometric detection gives similar results to the widely used cyclic voltammetry methodology and closely correlates with ORAC and TRAP. The problem of electrode fouling is overcome by the introduction of an electrochemical cleaning step (1-2 min at the potential of 0 V vs Ag/AgCl). Such a procedure is sufficient to fully regenerate the electrode response for both red and white wine samples as well as catechin/Trolox standards. The appropriate size of microdialysis probes enables easy automation of the electrochemical TAC/TCP measurement using 96-well microtitration plates.

Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

International Nuclear Information System (INIS)

Canellas, Catarine G.L.; Leitao, Roberta G.; Lopes, Ricardo T.; Bellido, Alfredo Victor B.; Anjos, Marcelino J.

2011-01-01

Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly (α = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Canellas, Catarine G.L.; Leitao, Roberta G; Lopes, Ricardo T., E-mail: catarine@lin.ufrj.b, E-mail: ricardo@lin.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear. Lab. de Instrumentaco Nuclear; Carvalho, Silvia M.F., E-mail: silvia@hemorio.rj.gov.b [State Institute of Hematology Arthur de Siqueira Cavalcanti (HEMORIO), Rio de Janeiro, RJ (Brazil); Bellido, Alfredo Victor B., E-mail: alfredo@ien.gov.b [Federal Fluminense University (UFF), Niteroi, RJ (Brazil). Chemistry Inst.; Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.b [State University of Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.

2011-07-01

Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly ({alpha} = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

Confocal total reflection X-ray fluorescence technology based on an elliptical monocapillary and a parallel polycapillary X-ray optics.

Science.gov (United States)

Zhu, Yu; Wang, Yabing; Sun, Tianxi; Sun, Xuepeng; Zhang, Xiaoyun; Liu, Zhiguo; Li, Yufei; Zhang, Fengshou

2018-07-01

A total reflection X-ray fluorescence (TXRF) spectrometer based on an elliptical monocapillary X-ray lens (MXRL) and a parallel polycapillary X-ray lens (PPXRL) was designed. This TXRF instrument has micro focal spot, low divergence and high intensity of incident X-ray beam. The diameter of the focal spot of MXRL was 16.5 µm, and the divergence of the incident X-ray beam was 3.4 mrad. We applied this TXRF instrument to the micro analysis of a single-layer film containing Ni deposited on a Si substrate by metal vapor vacuum arc ion source. Copyright © 2018 Elsevier Ltd. All rights reserved.

Coal rank (vitrinite reflectance) data for Cretaceous/Tertiary coal measures in the Grande Cache and Hinton areas, Alberta

Energy Technology Data Exchange (ETDEWEB)

Kalkreuth, W.D.; Langenberg, W.; McMechan, M.E.; Tomica, M.A.; McDougall, W.; Burchard, K.

1996-07-01

A total of 544 vitrinite reflectance values are reported. The outcrop locations and other pertinent data are listed. Vitrinite reflectances determined in subsurface samples from two coal exploration boreholes and 13 petroleum exploration wells are tabulated. The data have been used (in other studies) to evaluate maturation levels in potential source rocks and to assess methane potential of the coal deposits. A diskette containing the data is included. 18 refs., 1 fig., 2 tabs.

Spectral Mining for Discriminating Blood Origins in the Presence of Substrate Interference via Attenuated Total Reflection Fourier Transform Infrared Spectroscopy: Postmortem or Antemortem Blood?

Science.gov (United States)

Takamura, Ayari; Watanabe, Ken; Akutsu, Tomoko; Ikegaya, Hiroshi; Ozawa, Takeaki

2017-09-19

Often in criminal investigations, discrimination of types of body fluid evidence is crucially important to ascertain how a crime was committed. Compared to current methods using biochemical techniques, vibrational spectroscopic approaches can provide versatile applicability to identify various body fluid types without sample invasion. However, their applicability is limited to pure body fluid samples because important signals from body fluids incorporated in a substrate are affected strongly by interference from substrate signals. Herein, we describe a novel approach to recover body fluid signals that are embedded in strong substrate interferences using attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy and an innovative multivariate spectral processing. This technique supported detection of covert features of body fluid signals, and then identified origins of body fluid stains on substrates. We discriminated between ATR FT-IR spectra of postmortem blood (PB) and those of antemortem blood (AB) by creating a multivariate statistics model. From ATR FT-IR spectra of PB and AB stains on interfering substrates (polyester, cotton, and denim), blood-originated signals were extracted by a weighted linear regression approach we developed originally using principal components of both blood and substrate spectra. The blood-originated signals were finally classified by the discriminant model, demonstrating high discriminant accuracy. The present method can identify body fluid evidence independently of the substrate type, which is expected to promote the application of vibrational spectroscopic techniques in forensic body fluid analysis.

Chemometric analysis of attenuated total reflectance infrared spectra of Proteus mirabilis strains with defined structures of LPS.

Science.gov (United States)

Zarnowiec, Paulina; Mizera, Andrzej; Chrapek, Magdalena; Urbaniak, Mariusz; Kaca, Wieslaw

2016-07-01

Proteus spp. strains are some of the most important pathogens associated with complicated urinary tract infections and bacteremia affecting patients with immunodeficiency and long-term urinary catheterization. For epidemiological purposes, various molecular typing methods have been developed for this pathogen. However, these methods are labor intensive and time consuming. We evaluated a new method of differentiation between strains. A collection of Proteus spp. strains was analyzed by attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy in the mid-infrared region. ATR FT-IR spectroscopy used in conjunction with a diamond ATR accessory directly produced the biochemical profile of the surface chemistry of bacteria. We conclude that a combination of ATR FT-IR spectroscopy and mathematical modeling provides a fast and reliable alternative for discrimination between Proteus isolates, contributing to epidemiological research. © The Author(s) 2016.

Assessing Reflection: Understanding Skill Development through Reflective Learning Journals

Science.gov (United States)

Cathro, Virginia; O'Kane, Paula; Gilbertson, Deb

2017-01-01

Purpose: The purpose of this paper is to suggest ways in which business educators can interact successfully with reflective learning journals (RLJs). Specifically, the research was interested in how students used RLJs and how educators assessed these RLJs. Design/methodology/approach: In total, 31 RLJs, submitted as part of an international…

Assessing total nitrogen in surface-water samples--precision and bias of analytical and computational methods

Science.gov (United States)

Rus, David L.; Patton, Charles J.; Mueller, David K.; Crawford, Charles G.

2013-01-01

The characterization of total-nitrogen (TN) concentrations is an important component of many surface-water-quality programs. However, three widely used methods for the determination of total nitrogen—(1) derived from the alkaline-persulfate digestion of whole-water samples (TN-A); (2) calculated as the sum of total Kjeldahl nitrogen and dissolved nitrate plus nitrite (TN-K); and (3) calculated as the sum of dissolved nitrogen and particulate nitrogen (TN-C)—all include inherent limitations. A digestion process is intended to convert multiple species of nitrogen that are present in the sample into one measureable species, but this process may introduce bias. TN-A results can be negatively biased in the presence of suspended sediment, and TN-K data can be positively biased in the presence of elevated nitrate because some nitrate is reduced to ammonia and is therefore counted twice in the computation of total nitrogen. Furthermore, TN-C may not be subject to bias but is comparatively imprecise. In this study, the effects of suspended-sediment and nitrate concentrations on the performance of these TN methods were assessed using synthetic samples developed in a laboratory as well as a series of stream samples. A 2007 laboratory experiment measured TN-A and TN-K in nutrient-fortified solutions that had been mixed with varying amounts of sediment-reference materials. This experiment identified a connection between suspended sediment and negative bias in TN-A and detected positive bias in TN-K in the presence of elevated nitrate. A 2009–10 synoptic-field study used samples from 77 stream-sampling sites to confirm that these biases were present in the field samples and evaluated the precision and bias of TN methods. The precision of TN-C and TN-K depended on the precision and relative amounts of the TN-component species used in their respective TN computations. Particulate nitrogen had an average variability (as determined by the relative standard deviation) of 13

Comparison of total Hg results in sediment samples from Rio Grande reservoir determine by NAA and CV AAS

International Nuclear Information System (INIS)

Franklin, Robson L.

2011-01-01

The Rio Grande reservoir is located in the Metropolitan area of Sao Paulo and it is used for recreation purposes and as source water for drinking water production. During the last decades has been detected mercury contamination in the sediments of this reservoir, mainly in the eastern part, near the main affluent of the reservoir, in the Rio Grande da Serra and Ribeirao Pires counties. In the present study bottom sediment samples were collected in four different sites into four sampling campaigns during the period of September 2008 to January 2010. The samples were dried at room temperature, ground and passed through a 2 mm sieve. Total Hg determination in the sediment samples was carried out by two different analytical techniques: neutron activation analysis (NAA) and cold vapor atomic absorption spectrometry (CV AAS). The methodology validation, in terms of precision and accuracy, was performed by reference materials, and presented a recovery of 83 to 108%. The total Hg results obtained by both analytical techniques ranged from 3 to 71 mg kg-1 and were considered similar by statistical analysis, even though NAA technique furnishes the total concentration while CV AAS using the 3015 digestion procedure characterizes only the bioavailable Hg. These results confirm that both analytical techniques were suitable to detect the Hg concentration levels in the Rio Grande sediments studied. The Hg levels in the sediment of the Rio Grande reservoir confirm the anthropogenic origin for this element in this ecosystem. (author)

Avoiding Pitfalls and Realising Opportunities: Reflecting on Issues of Sampling and Recruitment for Online Focus Groups.

Science.gov (United States)

Boydell, Nicola; Fergie, Gillian; McDaid, Lisa; Hilton, Shona

2014-02-01

The increasing prominence of the Internet in everyday life has prompted methodological innovations in qualitative research, particularly the adaptation of established methods of data collection for use online. The alternative online context brings with it both opportunities and challenges. To date the literature on online focus groups has focused mainly on the suitability of the method for qualitative data collection, and the development of approaches to facilitation that maximise interaction. By reflecting on our experiences of designing and attempting to recruit participants to online focus groups for two exploratory research projects, we aim to contribute some novel reflections around the less articulated issues of sampling and recruitment for online focus groups. In particular, we highlight potentially problematic issues around offline recruitment for an online method of data collection; the potential of using social media for recruitment; and the uncertainties around offering incentives in online recruitment, issues which have received little attention in the growing literature around online focus groups. More broadly, we recommend continued examination of online social practices and the social media environment to develop appropriate and timely online recruitment strategies and suggest further areas for future research and innovation.

Avoiding Pitfalls and Realising Opportunities: Reflecting on Issues of Sampling and Recruitment for Online Focus Groups

Directory of Open Access Journals (Sweden)

Nicola Boydell MSc

2014-02-01

Full Text Available The increasing prominence of the Internet in everyday life has prompted methodological innovations in qualitative research, particularly the adaptation of established methods of data collection for use online. The alternative online context brings with it both opportunities and challenges. To date the literature on online focus groups has focused mainly on the suitability of the method for qualitative data collection, and the development of approaches to facilitation that maximise interaction. By reflecting on our experiences of designing and attempting to recruit participants to online focus groups for two exploratory research projects, we aim to contribute some novel reflections around the less articulated issues of sampling and recruitment for online focus groups. In particular, we highlight potentially problematic issues around offline recruitment for an online method of data collection; the potential of using social media for recruitment; and the uncertainties around offering incentives in online recruitment, issues which have received little attention in the growing literature around online focus groups. More broadly, we recommend continued examination of online social practices and the social media environment to develop appropriate and timely online recruitment strategies and suggest further areas for future research and innovation.

Quantitative determination on heavy metals in different stages of wine production by Total Reflection X-ray Fluorescence and Energy Dispersive X-ray Fluorescence: Comparison on two vineyards

Energy Technology Data Exchange (ETDEWEB)

Pessanha, Sofia [Centro Fisica Atomica, Departamento de Fisica, Faculdade de Ciencias, Universidade de Lisboa, Av. Prof. Gama Pinto, 2, 1649-003 Lisboa (Portugal); Carvalho, Maria Luisa, E-mail: luisa@cii.fc.ul.p [Centro Fisica Atomica, Departamento de Fisica, Faculdade de Ciencias, Universidade de Lisboa, Av. Prof. Gama Pinto, 2, 1649-003 Lisboa (Portugal); Becker, Maria; Bohlen, Alex von [Institute for analytical Sciences, Bunsen-Kirchhoff-Str. 11, 44139 Dortmund (Germany)

2010-06-15

The purpose of this study is to determine the elemental content, namely heavy metals, of samples of vine-leaves, grapes must and wine. In order to assess the influence of the vineyard age on the elemental content throughout the several stages of wine production, elemental determinations of trace elements were made on products obtained from two vineyards aged 6 and 14 years from Douro region. The elemental content of vine-leaves and grapes was determined by Energy Dispersive X-Ray Fluorescence (EDXRF), while analysis of the must and wine was performed by Total Reflection X-ray Fluorescence (TXRF). Almost all elements present in wine and must samples did not exceed the recommended values found in literature for wine. Bromine was present in the 6 years old wine in a concentration 1 order of magnitude greater than what is usually detected. The Cu content in vine-leaves from the older vineyard was found to be extremely high probably due to excessive use of Cu-based fungicides to control vine downy mildew. Higher Cu content was also detected in grapes although not so pronounced. Concerning the wine a slightly higher level was detected on the older vineyard, even so not exceeding the recommended value.

Quantitative determination on heavy metals in different stages of wine production by Total Reflection X-ray Fluorescence and Energy Dispersive X-ray Fluorescence: Comparison on two vineyards

International Nuclear Information System (INIS)

Pessanha, Sofia; Carvalho, Maria Luisa; Becker, Maria; Bohlen, Alex von

2010-01-01

The purpose of this study is to determine the elemental content, namely heavy metals, of samples of vine-leaves, grapes must and wine. In order to assess the influence of the vineyard age on the elemental content throughout the several stages of wine production, elemental determinations of trace elements were made on products obtained from two vineyards aged 6 and 14 years from Douro region. The elemental content of vine-leaves and grapes was determined by Energy Dispersive X-Ray Fluorescence (EDXRF), while analysis of the must and wine was performed by Total Reflection X-ray Fluorescence (TXRF). Almost all elements present in wine and must samples did not exceed the recommended values found in literature for wine. Bromine was present in the 6 years old wine in a concentration 1 order of magnitude greater than what is usually detected. The Cu content in vine-leaves from the older vineyard was found to be extremely high probably due to excessive use of Cu-based fungicides to control vine downy mildew. Higher Cu content was also detected in grapes although not so pronounced. Concerning the wine a slightly higher level was detected on the older vineyard, even so not exceeding the recommended value.

Spatial distribution and trends of total mercury in waters of the Great Lakes and connecting channels using an improved sampling technique

International Nuclear Information System (INIS)

Dove, A.; Hill, B.; Klawunn, P.; Waltho, J.; Backus, S.; McCrea, R.C.

2012-01-01

Environment Canada recently developed a clean method suitable for sampling trace levels of metals in surface waters. The results of sampling for total mercury in the Laurentian Great Lakes between 2003 and 2009 give a unique basin-wide perspective of concentrations of this important contaminant and represent improved knowledge of mercury in the region. Results indicate that concentrations of total mercury in the offshore regions of the lakes were within a relatively narrow range from about 0.3 to 0.8 ng/L. The highest concentrations were observed in the western basin of Lake Erie and concentrations then declined towards the east. Compared to the offshore, higher levels were observed at some nearshore locations, particularly in lakes Erie and Ontario. The longer-term temporal record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease in equivalent water concentrations since 1986. - Highlights: ► Basin-wide concentrations of total mercury in Great Lakes surface waters are provided for the first time. ► A clean sampling method is described, stressing isolation of the sample from extraneous sources of contamination. ► Sub-ng/L concentrations of total mercury are observed in most Great Lakes offshore areas. ► Concentrations in the western basin of Lake Erie are consistently the highest observed in the basin. ► The longer-term record of mercury in Niagara River suspended sediments indicates an approximate 30% decrease since 1986. - A new, clean sampling method for metals is described and basin-wide measurements of total mercury are provided for Great Lakes surface waters for the first time.

Simultaneous Effects of Total Solids Content, Milk Base, Heat Treatment Temperature and Sample Temperature on the Rheological Properties of Plain Stirred Yogurt

Directory of Open Access Journals (Sweden)

Attilio Converti

2006-01-01

Full Text Available Response surface methodology was used to establish a relationship between total solids content, milk base, heat treatment temperature, and sample temperature, and consistency index, flow behaviour index, and apparent viscosity of plain stirred yogurts. Statistical treatments resulted in developments of mathematical models. All samples presented shear thinning fluid behaviour. The increase of the content of total solids (9.3–22.7 % and milk base heat treatment temperature (81.6–98.4 °C resulted in a significant increase in consistency index and a decrease in flow behaviour index. Increase in the sample temperature (1.6–18.4 °C caused a decrease in consistency index and increase in flow behaviour index. Apparent viscosity was directly related to the content of total solids. Rheological properties of yogurt were highly dependent on the content of total solids in milk.

Quantitative analysis of phosphoinositide 3-kinase (PI3K) signaling using live-cell total internal reflection fluorescence (TIRF) microscopy.

Science.gov (United States)

Johnson, Heath E; Haugh, Jason M

2013-12-02

This unit focuses on the use of total internal reflection fluorescence (TIRF) microscopy and image analysis methods to study the dynamics of signal transduction mediated by class I phosphoinositide 3-kinases (PI3Ks) in mammalian cells. The first four protocols cover live-cell imaging experiments, image acquisition parameters, and basic image processing and segmentation. These methods are generally applicable to live-cell TIRF experiments. The remaining protocols outline more advanced image analysis methods, which were developed in our laboratory for the purpose of characterizing the spatiotemporal dynamics of PI3K signaling. These methods may be extended to analyze other cellular processes monitored using fluorescent biosensors. Copyright © 2013 John Wiley & Sons, Inc.

Non-invasive identification of organic materials in historical stringed musical instruments by reflection infrared spectroscopy: a methodological approach.

Science.gov (United States)

Invernizzi, Claudia; Daveri, Alessia; Vagnini, Manuela; Malagodi, Marco

2017-05-01

The analysis of historical musical instruments is becoming more relevant and the interest is increasingly moving toward the non-invasive reflection FTIR spectroscopy, especially for the analysis of varnishes. In this work, a specific infrared reflectance spectral library of organic compounds was created with the aim of identifying musical instrument materials in a totally non-invasive way. The analyses were carried out on pure organic compounds, as bulk samples and laboratory wooden models, to evaluate the diagnostic reflection mid-infrared (MIR) bands of proteins, polysaccharides, lipids, and resins by comparing reflection spectra before and after the KK correction. This methodological approach was applied to real case studies represented by four Stradivari violins and a Neapolitan mandolin.

Application of attenuated total reflectance Fourier transform infrared spectroscopy for determination of cefixime in oral pharmaceutical formulations.

Science.gov (United States)

Kandhro, Aftab A; Laghari, Abdul Hafeez; Mahesar, Sarfaraz A; Saleem, Rubina; Nelofar, Aisha; Khan, Salman Tariq; Sherazi, S T H

2013-11-01

A quick and reliable analytical method for the quantitative assessment of cefixime in orally administered pharmaceutical formulations is developed by using diamond cell attenuated total reflectance (ATR) Fourier transform infrared (FT-IR) spectroscopy as an easy procedure for quality control laboratories. The standards for calibration were prepared in aqueous medium ranging from 350 to 6000mg/kg. The calibration model was developed based on partial least square (PLS) using finger print region of FT-IR spectrum in the range from 1485 to 887cm(-1). Excellent coefficient of determination (R(2)) was achieved as high as 0.99976 with root mean square error of 44.8 for calibration. The application of diamond cell (smart accessory) ATR FT-IR proves a reliable determination of cefixime in pharmaceutical formulations to assess the quality of the final product. Copyright © 2013 Elsevier B.V. All rights reserved.

Application of a portable total reflection x-ray fluorescence spectrometer to a trace elemental analysis of wines

International Nuclear Information System (INIS)

Kunimura, Shinsuke; Kawai, Jun

2009-01-01

A portable total reflection X-ray fluorescence (TXRF) spectrometer has been applied to a trace elemental analysis of wines. Sulfur, K, Mn, Fe, and Rb were detected. These five elements were quantified by using 1 ppm of Co as an internal standard. The quantified concentrations ranged from sub-ppm to several hundred ppm. Because of organic substances in wines, the scattering of the incident X-rays from the dry residues of wines becomes strong. Therefore, a high spectral background appears in TXRF spectra of wines. Because of this background, relative standard deviations of the quantified concentrations were from 4 to 28%. Although the high spectral background appeared in the TXRF spectra of the wines, a detection limit down to several tens of ppb was achieved. The present portable spectrometer can be applied to screening for trace elements in wines before an accurate and precise analysis using a large elemental analyzer. (author)

Biomonitoring in rivers by total-reflection x-ray fluorescence analysis in macrozoobenthos samples

International Nuclear Information System (INIS)

Miesbauer, H.; Koeck, G.; Fuereder, L.

2000-01-01

A widespread set of analytical methods is used to control the fate of toxic metals in aquatic ecosystems. However, monitoring of water and sediments by metal analysis is not sufficient because of fluctuating metal concentrations in the water and delayed responses of sediments. It also provides little information about metal bioavailability in aquatic ecosystems. Therefore, aquatic organisms are increasingly used for biomonitoring the actual metal load of aquatic biota. Aquatic insects, in particular, satisfy some important criteria established for bioindicators, thus being valuable biomonitoring organisms of metal contamination in freshwater ecosystems. The presented paper describes the investigation of the metal contents of several benthic insect species (e.g. caddisfly larvae) from an Austrian river by using TXRF. Due to it's high sensitivity TXRF allows multi-element analysis of very low metal concentrations even in single individuals of aquatic insect larvae. Our results confirm TXRF to be valuable tool in environmental analysis. (author)

Biomonitoring in rivers by total-reflection x-ray fluorescence analysis in macrozoobenthos samples

International Nuclear Information System (INIS)

Miesbauer, H.; Koeck, G.; Fuereder, L.

2000-01-01

A widespread set of analytical methods is used to control the fate of toxic metals in aquatic ecosystems. However, monitoring of water and sediments by metal analysis is not sufficient because of fluctuating metal concentrations in the water and delayed responses of sediments. It also provides little information about metal bio-availability in aquatic ecosystems. Therefore, aquatic organisms are increasingly used for bio-monitoring the actual metal load of aquatic biota. Aquatic insects, in particular, satisfy some important criteria established for bio-indicators, thus being valuable bio-monitoring organisms of metal contamination in freshwater ecosystems. The presented paper describes the investigation of the metal contents of several benthic insect species (e.g. caddisfly larvae) from an Austrian river by using TXRF. Due to it's high sensitivity TXRF allows multi-element analysis of very low metal concentrations even in single individuals of aquatic insect larvae. Our results confirm TXRF to be valuable tool in environmental analysis. (author)

CERAD Neuropsychological Total Scores Reflect Cortical Thinning in Prodromal Alzheimer's Disease

Directory of Open Access Journals (Sweden)

T. Paajanen

2013-11-01

Full Text Available Background: Sensitive cognitive global scores are beneficial in screening and monitoring for prodromal Alzheimer's disease (AD. Early cortical changes provide a novel opportunity for validating established cognitive total scores against the biological disease markers. Methods: We examined how two different total scores of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD battery and the Mini-Mental State Examination (MMSE are associated with cortical thickness (CTH in mild cognitive impairment (MCI and prodromal AD. Cognitive and magnetic resonance imaging (MRI data of 22 progressive MCI, 78 stable MCI, and 98 control subjects, and MRI data of 103 AD patients of the prospective multicenter study were analyzed. Results: CERAD total scores correlated with mean CTH more strongly (r = 0.34-0.38, p Conclusion: CERAD total scores are sensitive to the CTH signature of prodromal AD, which supports their biological validity in detecting early disease-related cognitive changes.

Simultaneous determination of CRP and D-dimer in human blood plasma samples with White Light Reflectance Spectroscopy.

Science.gov (United States)

Koukouvinos, Georgios; Petrou, Panagiota; Misiakos, Konstantinos; Drygiannakis, Dimitris; Raptis, Ioannis; Stefanitsis, Gerasimos; Martini, Spyridoula; Nikita, Dimitra; Goustouridis, Dimitrios; Moser, Isabella; Jobst, Gerhard; Kakabakos, Sotirios

2016-10-15

A dual-analyte assay for the simultaneous determination of C-reactive protein (CRP) and D-dimer in human blood plasma based on a white light interference spectroscopy sensing platform is presented. Measurement is accomplished in real-time by scanning the sensing surface, on which distinct antibody areas have been created, with a reflection probe used both for illumination of the surface and collection of the reflected interference spectrum. The composition of the transducer, the sensing surface chemical activation and biofunctionalization procedures were optimized with respect to signal magnitude and repeatability. The assay format involved direct detection of CRP whereas for D-dimer a two-site immunoassay employing a biotinylated reporter antibody and reaction with streptavidin was selected. The assays were sensitive with detection limits of 25ng/mL for both analytes, precise with intra- and inter-assay CV values ranging from 3.6% to 7.7%, and from 4.8% to 9.5%, respectively, for both assays, and accurate with recovery values ranging from 88.5% to 108% for both analytes. Moreover, the values determined for the two analytes in 35 human plasma samples were in excellent agreement with those received for the same samples by standard diagnostic laboratory instrumentation employing commercial kits. The excellent agreement of the results supported the validity of the proposed system for clinical application for the detection of multiple analytes since it was demonstrated that up to seven antibody areas can be created on the sensing surface and successfully interrogated with the developed optical set-up. Copyright © 2015. Published by Elsevier B.V.

Slow neutron total cross-section, transmission and reflection calculation for poly- and mono-NaCl and PbF{sub 2} crystals

Energy Technology Data Exchange (ETDEWEB)

Mansy, Muhammad S., E-mail: mmansy88@asrt.sci.eg [Reactor Physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt); Radioactive Waste Management Unit, Hot Labs Centre, Atomic Energy Authority, Cairo (Egypt); Adib, M.; Habib, N. [Reactor Physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt); Bashter, I.I. [Physics Department, Faculty of Science, Zagazig University (Egypt); Morcos, H.N.; El-Mesiry, M.S. [Reactor Physics Department, Nuclear Research Centre, Atomic Energy Authority, Cairo (Egypt)

2016-10-01

Highlights: • Slow neutron cross-section calculation for poly- and mono-crystalline materials. • Monochromatic features of PbF{sub 2} and NaCl mono-crystals. • Characterization of poly- and mono-crystal filters used in neutron diffraction. • Computer code developed calculates neutron cross-section, transmission & reflection. - Abstract: A detailed study about the calculation of total neutron cross-section, transmission and reflection from crystalline materials was performed. The developed computer code is approved to be sufficient for the required calculations, also an excellent agreement has been shown when comparing the code results with the other calculated and measured values. The optimal monochromator and filter parameters were discussed in terms of crystal orientation, mosaic spread, and thickness. Calculations show that 30 cm thick of PbF{sub 2} poly-crystal is an excellent cold neutron filter producing neutron wavelengths longer than 0.66 nm needed for the investigation of magnetic structure experiments. While mono-crystal filter PbF{sub 2} cut along its (1 1 1), having mosaic spread (η = 0.5°) and thickness 10 cm can only transmit thermal neutrons of the desired wavelengths and suppress epithermal and γ-rays forming unwanted background, when it is cooled to liquid nitrogen temperature. NaCl (2 0 0) and PbF{sub 2} (1 1 1) monochromator crystals having mosaic spread (η = 0.5°) and thickness 10 mm shows high neutron reflectivity for neutron wavelengths (λ = 0.114 nm and λ = 0.43 nm) when they used as a thermal and cold neutron monochromators respectively with very low contamination from higher order reflections.

Evaluation of Fe and Zn/Cu ratio in serum of patients with sickle cell anemia by total reflection X-ray fluorescence using synchrotron radiation

Energy Technology Data Exchange (ETDEWEB)

Canellas, Catarine G.L.; Leitao, Roberta G.; Lopes, Ricardo T., E-mail: catarine@lin.ufrj.b, E-mail: ricardo@lin.ufrj.b [Universidade Federal do Rio de Janeiro (PEN/COPPE/UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-Graduacao de Engenharia. Programa de Engenharia Nuclear. Lab. de Instrumentaco Nuclear; Carvalho, Silvia M.F., E-mail: silvia@hemorio.rj.gov.b [State Institute of Hematology Arthur de Siqueira Cavalcanti (HEMORIO), Rio de Janeiro, RJ (Brazil); Bellido, Alfredo Victor B., E-mail: alfredo@ien.gov.b [Federal Fluminense University (UFF), Niteroi, RJ (Brazil). Chemistry Inst.; Anjos, Marcelino J., E-mail: marcelin@lin.ufrj.b [State University of Rio de Janeiro (UERJ), RJ (Brazil). Physics Inst.

2011-07-01

Sickle cell anemia (SCA) is a blood disorder that affects hemoglobin, the protein found in red blood cells that help carry oxygen throughout the body. In this work we have analyzed serum samples from patients with SCA by using total reflection X-ray fluorescence using synchrotron radiation (SRTXRF). The SRTXRF measurements were performed at the X-ray fluorescence beamline at Brazilian National Synchrotron Light Laboratory (LNLS), in Campinas, Sao Paulo using a polychromatic beam. We have studied forty-three patients aged 18-50 years old, suffering from SCA and Sixty healthy volunteers aged 18-60 years old. It was possible to determine the concentrations of the following elements: P, S, Cl, K, Ca, Fe, Cu, Zn, Br and Rb. Student's t-test was applied in order to check whether the two populations (CG x SCA) had the same mean values. It was observed that elemental concentration of P, Cl, K, Fe, Cu, Zn and Br differed significantly ({alpha} = 0.05) between groups of healthy subjects and SCA. The concentrations of K, Fe and Cu in the serum samples of patients with SCA were larger 15%, 120 % and 20 %, respectively, when compared with the CG. On the other hand, the concentrations of P (-20 %), Cl (-6 %), Zn (-25 %) and Br (-22 %) were smaller than the values determined for the control group. The serum level Cu/Zn ratio was significantly higher (60%) in the serum samples of patients with SCA group than the CG. So, the Cu/Zn ratio can be used as an adjuvant index in enhancement for diagnosis of SCA. There are evidences of an association among Fe, Cu, Zn and Cu/Zn in the SCA pathogenesis process. (author)

Development of Total Reflection X-ray fluorescence spectrometry quantitative methodologies for elemental characterization of building materials and their degradation products

Science.gov (United States)

García-Florentino, Cristina; Maguregui, Maite; Marguí, Eva; Torrent, Laura; Queralt, Ignasi; Madariaga, Juan Manuel

2018-05-01

In this work, a Total Reflection X-ray fluorescence (TXRF) spectrometry based quantitative methodology for elemental characterization of liquid extracts and solids belonging to old building materials and their degradation products from a building of the beginning of 20th century with a high historic cultural value in Getxo, (Basque Country, North of Spain) is proposed. This quantification strategy can be considered a faster methodology comparing to traditional Energy or Wavelength Dispersive X-ray fluorescence (ED-XRF and WD-XRF) spectrometry based methodologies or other techniques such as Inductively Coupled Plasma Mass Spectrometry (ICP-MS). In particular, two kinds of liquid extracts were analysed: (i) water soluble extracts from different mortars and (ii) acid extracts from mortars, black crusts, and calcium carbonate formations. In order to try to avoid the acid extraction step of the materials and their degradation products, it was also studied the TXRF direct measurement of the powdered solid suspensions in water. With this aim, different parameters such as the deposition volume and the measuring time were studied for each kind of samples. Depending on the quantified element, the limits of detection achieved with the TXRF quantitative methodologies for liquid extracts and solids were set around 0.01-1.2 and 2-200 mg/L respectively. The quantification of K, Ca, Ti, Mn, Fe, Zn, Rb, Sr, Sn and Pb in the liquid extracts was proved to be a faster alternative to other more classic quantification techniques (i.e. ICP-MS), accurate enough to obtain information about the composition of the acidic soluble part of the materials and their degradation products. Regarding the solid samples measured as suspensions, it was quite difficult to obtain stable and repetitive suspensions affecting in this way the accuracy of the results. To cope with this problem, correction factors based on the quantitative results obtained using ED-XRF were calculated to improve the accuracy of

Modeling Microalgal Biosediment Formation Based on Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) Monitoring.

Science.gov (United States)

Ogburn, Zachary L; Vogt, Frank

2018-03-01

With increasing amounts of anthropogenic pollutants being released into ecosystems, it becomes ever more important to understand their fate and interactions with living organisms. Microalgae play an important ecological role as they are ubiquitous in marine environments and sequester inorganic pollutants which they transform into organic biomass. Of particular interest in this study is their role as a sink for atmospheric CO 2 , a greenhouse gas, and nitrate, one cause of harmful algal blooms. Novel chemometric hard-modeling methodologies have been developed for interpreting phytoplankton's chemical and physiological adaptations to changes in their growing environment. These methodologies will facilitate investigations of environmental impacts of anthropogenic pollutants on chemical and physiological properties of marine microalgae (here: Nannochloropsis oculata). It has been demonstrated that attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy can gain insights into both and this study only focuses on the latter. From time-series of spectra, the rate of microalgal biomass settling on top of a horizontal ATR element is derived which reflects several of phytoplankton's physiological parameters such as growth rate, cell concentrations, cell size, and buoyancy. In order to assess environmental impacts on such parameters, microalgae cultures were grown under 25 different chemical scenarios covering 200-600 ppm atmospheric CO 2 and 0.35-0.75 mM dissolved NO 3 - . After recording time-series of ATR FT-IR spectra, a multivariate curve resolution-alternating least squares (MCR-ALS) algorithm extracted spectroscopic and time profiles from each data set. From the time profiles, it was found that in the considered concentration ranges only NO 3 - has an impact on the cells' physiological properties. In particular, the cultures' growth rate has been influenced by the ambient chemical conditions. Thus, the presented spectroscopic�

Impact of blood sampling in very preterm infants

DEFF Research Database (Denmark)

Madsen, L P; Rasmussen, M K; Bjerregaard, L L

2000-01-01

; the groups were then subdivided into critically ill or not. Diagnostic blood sampling and blood transfusion events were recorded. In total, 1905 blood samples (5,253 analysis) were performed, corresponding to 0.7 samples (1.9 analysis) per day per infant. The highest frequencies were found during the first....../kg. For the extremely preterm infants a significant correlation between sampled and transfused blood volume was found (mean 37.1 and 33.3 ml/kg, respectively, r = + 0.71, p = 0.0003). The most frequently requested analyses were glucose, sodium and potassium. Few blood gas analyses were requested (1.9/ infant). No blood...... losses attributable to excessive generous sampling were detected. The results show an acceptable low frequency of sampling and transfusion events for infants of GA 28-32 weeks. The study emphasizes the necessity of thorough reflection and monitoring of blood losses when ordering blood sampling...

Analysis for reflection peaks of multiple-phase-shift based sampled fiber Bragg gratings and application in high channel-count filter design.

Science.gov (United States)

Wen, Kun Hua; Yan, Lian Shan; Pan, Wei; Luo, Bin; Zou, Xi Hua; Ye, Jia; Ma, Ya Nan

2009-10-10

An analytical expression for calculating the reflection-peak wavelengths (RPWs) of a uniform sampled fiber Bragg grating (SFBG) with the multiple-phase-shift (MPS) technique is derived through Fourier transform of the index modulation. The new expression can accurately depict the RPWs incorporating various parameters such as the duty cycle and the DC index change. The effectiveness of the derived expression is further confirmed by comparing the RPWs estimated from the expression with the simulated reflective spectra using the piecewise uniform method. And the reflective spectrum has been well optimized by introducing the Gaussian apodization function to suppress the sidelobes without any wavelength shift on the RPWs. Then, a high-channel-count comb filter based on MPS is proposed by cascading two or more SFBGs with different Bragg periods but with the same RPWs. Noticeably, the RPWs of the new structured SFBG can also be accurately calculated through the expression. Furthermore, the number of spectral channels can be controlled by choosing gratings with specified difference Bragg periods.

Determination Of Refractive Index And Reflectivity Of Thin Layer With Optical Absorption Method; PENENTUAN INDEKS BIAS DAN REFLEKTIVITAS LAPISAN TIPIS DENGAN METODA SERAPAN OPTIK

Energy Technology Data Exchange (ETDEWEB)

Hariyanto, Sigit; Budianto, Anwar; Subarkah,; Atmono, Trimarji [Yogyakarta Nuclear Research Center, National Nuclear Energy Agency, Yogyakarta (Indonesia)

1996-04-15

. The refractive index and reflectivity of ASi:H and Si Ox thin layer have been observed by optical absorption methods. Measurement has been done after the preparation of optical system which consists of a halogen lamp light source, monochromator, sample and light detector. The Monochromator output showed that measured halogen lamp spectrum light is between 470 nm -750 nm. The maximum voltage of halogen lamp is 220 Volt, the output light increases in intensity while the wave length increases. The inclination of intensity decrease at the wave length of 725 nm. The result of the calculation of refractive index varies in accordance with the wave length. The average refractive index of ASi:H is nf a = 1.753. The total reflectivity of air-thin layer-substrate is Rt a = 0.315. The refractive index of Si Ox sample is nf b2.182 and the total reflectivity is Rt b=O,514.

Development of improved space sampling strategies for ocean chemical properties: Total carbon dioxide and dissolved nitrate

Science.gov (United States)

Goyet, Catherine; Davis, Daniel; Peltzer, Edward T.; Brewer, Peter G.

1995-01-01

Large-scale ocean observing programs such as the Joint Global Ocean Flux Study (JGOFS) and the World Ocean Circulation Experiment (WOCE) today, must face the problem of designing an adequate sampling strategy. For ocean chemical variables, the goals and observing technologies are quite different from ocean physical variables (temperature, salinity, pressure). We have recently acquired data on the ocean CO2 properties on WOCE cruises P16c and P17c that are sufficiently dense to test for sampling redundancy. We use linear and quadratic interpolation methods on the sampled field to investigate what is the minimum number of samples required to define the deep ocean total inorganic carbon (TCO2) field within the limits of experimental accuracy (+/- 4 micromol/kg). Within the limits of current measurements, these lines were oversampled in the deep ocean. Should the precision of the measurement be improved, then a denser sampling pattern may be desirable in the future. This approach rationalizes the efficient use of resources for field work and for estimating gridded (TCO2) fields needed to constrain geochemical models.

Clinical supervision reflected in a Danish DPCCQ sample

DEFF Research Database (Denmark)

Nielsen, Jan; Jacobsen, Claus Haugaard

Core Questionnaire (DPCCQ) has only few questions on supervision. To rectify this limitation, a recent Danish version of the DPCCQ included two new sections on supervision, one focusing on supervisees and another on supervisors and their supervisory training. This paper presents our initial findings...... on giving and receiving clinical supervision as reported by therapists in Denmark. Method: Currently, the Danish sample consists of 350 clinical psychologist doing psychotherapy who completed DPCCQ. Data are currently being prepared for statistical analysis. Results: This paper will focus primarily...... on describing the amount and type of supervision received and given by the sample. Findings from these descriptive statistics will be compared within the sample across demographic parameters such as age and sex, and professional characteristics such as career level, theoretical preferences, type of clients...

Room temperature trapping of stibine and bismuthine onto quartz substrates coated with nanostructured palladium for total reflection X-ray fluorescence analysis

Energy Technology Data Exchange (ETDEWEB)

Romero, Vanesa; Costas-Mora, Isabel; Lavilla, Isela; Bendicho, Carlos, E-mail: bendicho@uvigo.es

2015-05-01

In this work, a novel method for determining Sb and Bi based on the trapping of their covalent hydrides onto quartz reflectors coated with immobilized palladium nanoparticles (Pd NPs) followed by total reflection X-ray fluorescence (TXRF) analysis is proposed. Pd NPs were synthesized by chemical reduction of the metal precursor using a mixture of water:ethanol as mild reducing agent. Silanization using 3-mercaptopropyltrimethoxysilane (MPTMS) was performed for the immobilization of Pd NPs onto the quartz substrates. Volatile hydrides (stibine and bismuthine) generated by means of a continuous flow system were flushed onto the immobilized Pd NPs and retained by catalytic decomposition. As a result of the high catalytic activity of the nanostructured film, trapping can be performed at ambient temperature with good efficiency. Limits of detection (LODs) were 2.3 and 0.70 μg L{sup −1} for Sb and Bi, respectively. Enrichment factors of 534 and 192 were obtained for Sb and Bi, respectively. The new method was applied for the analysis of several matrices (milk, soil, sediment, cutaneous powder). Recoveries were in the range of 98.4–101% for both elements with a relative standard deviation of 2.5% (N = 5). - Highlights: • A novel method for trapping covalent hydrides of antimony and bismuth is proposed. • Emphasis is placed on the application of Pd nanoparticles as trapping surface. • The nanostructured surface provides high catalytic activity at ambient temperature. • Analysis by total reflection X-ray fluorescence is performed. • Determination of Bi and Sb in different matrices is carried out.

Total cross sections for slow-electron (1--20 eV) scattering in solid H2O

International Nuclear Information System (INIS)

Michaud, M.; Sanche, L.

1987-01-01

An analytical method is proposed to determine absolute total cross sections per scatterer and related mean free paths for low-energy electron scattering in disordered molecular solid films. The procedure is based on a two-stream multiple-scattering model of the thickness dependence of the film reflectivity for elastic electrons. The expected analytical behavior and accuracy are tested on a model sample whose scattering properties are generated by a Monte Carlo simulation from initially known parameters. The effects of multiple scattering inside the film and at its interfaces are taken into account and discussed. The thickness dependence of the elastic electron reflectivity of H 2 O film condensed at 14 K is reported between 1 and 20 eV incident energy with a spectrometer resolution of 10 MeV. The proposed method is applied to extract from these measurements the energy dependence of the total effective and total inelastic cross sections for electron scattering in amorphous ice

Method Performance of Total Mercury (Hg) Testing in the Biological Samples by Using Cold Vapour Atomic Absorption Spectrophotometer (CV-AAS)

International Nuclear Information System (INIS)

Susanna TS; Samin

2007-01-01

Method performance (validation) of total mercury (Hg) testing in the biological samples by using cold vapour atomic absorption spectrophotometer (CV-AAS) has been done. The objective of this research is to know the method performance of CV-AAS as one of points for the accreditation testing of laboratory according IS0/IEC 17025-2005. The method performance covering limit of detection (LOD), accuracy, precision and bias. As a standard material used SRM Oyster Tissue 15660 from Winopal Forshung Germany, whereas the biological samples were human hair. In principle of mercury testing for solid samples using CV-AAS is dissolving this sample and standard with 10 mL HNO 3 supra pure into a closed quartz tube and heating at 150 °C for 4 hours. The concentration of mercury in each samples was determined at the condition of operation were stirring time (T 1 ) 70 seconds, delay time (T 2 ) 15 seconds, heating time (T 3 ) 13 seconds and cooling time (T 4 ) of 25 seconds. Mercury ion in samples are reduced with SnCl 2 10 % in H 2 SO 4 20 %, and then the vapour of mercury from reduction is passed in NaOH 20 % solution and aquatridest. The result of method performance were: limit of detection (LOD) = 0.085 ng, accuracy 99.70 %, precision (RSD) = 1.64 % and bias = 0.30 %. From the validation result showed that the content of mercury total was in the range of certified values. The total mercury content (Hg) in human hair were varied from 406.93 - 699.07 ppb. (author)

Fast Focal Point Correction in Prism-Coupled Total Internal Reflection Scanning Imager Using an Electronically Tunable Lens

Directory of Open Access Journals (Sweden)

Chenggang Zhu

2018-02-01

Full Text Available Total internal reflection (TIR is useful for interrogating physical and chemical processes that occur at the interface between two transparent media. Yet prism-coupled TIR imaging microscopes suffer from limited sensing areas due to the fact that the interface (the object plane is not perpendicular to the optical axis of the microscope. In this paper, we show that an electrically tunable lens can be used to rapidly and reproducibly correct the focal length of an oblique-incidence scanning microscope (OI-RD in a prism-coupled TIR geometry. We demonstrate the performance of such a correction by acquiring an image of a protein microarray over a scan area of 4 cm2 with an effective resolution of less than 20 microns. The electronic focal length tuning eliminates the mechanical movement of the illumination lens in the scanning microscope and in turn the noise and background drift associated with the motion.

In-Sample Confidence Bands and Out-of-Sample Forecast Bands for Time-Varying Parameters in Observation Driven Models

NARCIS (Netherlands)

Blasques, F.; Koopman, S.J.; Lasak, K.A.; Lucas, A.

2016-01-01

We study the performances of alternative methods for calculating in-sample confidence and out-of-sample forecast bands for time-varying parameters. The in-sample bands reflect parameter uncertainty, while the out-of-sample bands reflect not only parameter uncertainty, but also innovation

Infrared surface analysis using a newly developed thin-sample preparation system.

Science.gov (United States)

Nagai, Naoto; Nishiyama, Itsuo; Kishima, Yoshio; Iida, Katsuhiko; Mori, Koichi

2009-01-01

We developed a new sampling system, the Nano Catcher, for measuring the surface chemical structure of polymers or industrial products and we evaluated the performance of the system. The system can directly pick up surface species whose depth is on the order of approximately 100 nm and can easily provide a sample for a Fourier transform infrared (FT-IR) system without the necessity of passing it over to a measurement plate. The FT-IR reflection data obtained from the Nano Catcher were compared with those obtained using the attenuated total reflection (ATR) method and sampling by hand. Chemical structural analysis of a depth region from a few tens of nanometers to a few hundred nanometers can be directly performed using this system. Such depths are beyond the scope of conventional X-ray photoelectron spectroscopy (XPS) and ATR methods. We can expect the use of the Nano Catcher system to lead to a great improvement in the detection of signals of surface species in these depth regions.

Frustrated total internal reflection in organic light-emitting diodes employing sphere cavity embedded in polystyrene

International Nuclear Information System (INIS)

Zhu, Peifen

2016-01-01

The light extraction efficiency of top-emitting organic light-emitting diodes (OLEDs) is numerically investigated employing the finite-difference time-domain method. The periodic nanostructures formed by embedding the sphere arrays in polystyrene (PS) are placed on top of OLED to frustrate the total internal reflection at the interface between OLED and free space. These nanostructures serve as an intermediate medium to extract the light out of OLED devices. Efficiently coupling both evanescent waves and propagation waves into spheres and subsequently extracting these light waves out of the sphere is key to achieving high extraction efficiency. By tuning the thickness of PS layer, both of the in-coupling efficiency and out-coupling efficiency are optimized for achieving high light extraction efficiency. Thicker PS layer results in higher in-coupling efficiency in sphere while the thinner PS layer leads to higher out-coupling efficiency. Thus the maximum light extraction is a trade-off between the in-coupling efficiency and out-coupling efficiency. The study shows that light extraction efficiency of 89% can be achieved by embedding 0.90 μm TiO 2 sphere in 0.30 μm PS layer with optimized in-coupling efficiency, out-coupling efficiency and cavity effect. (paper)

Self-rumination, self-reflection, and depression: self-rumination counteracts the adaptive effect of self-reflection.

Science.gov (United States)

Takano, Keisuke; Tanno, Yoshihiko

2009-03-01

Self-focused attention has adaptive and maladaptive aspects: self-reflection and self-rumination [Trapnell, P. D., & Campbell, J. D. (1999). Private self-consciousness and the Five-Factor Model of personality: distinguishing rumination from reflection. Journal of Personality and Social Psychology, 76, 284-304]. Although reflection is thought to be associated with problem solving and the promotion of mental health, previous researches have shown that reflection does not always have an adaptive effect on depression. Authors have examined the causes behind this inconsistency by modeling the relationships among self-reflection, self-rumination, and depression. One hundred and eleven undergraduates (91 men and 20 women) participated in a two-time point assessment with a 3-week interval. Statistical analysis with structural equation modeling showed that self-reflection significantly predicted self-rumination, whereas self-rumination did not predict self-reflection. With regard to depression, self-reflection was associated with a lower level of depression; self-rumination, with a higher level of depression. The total effect of self-reflection on depression was almost zero. This result indicates that self-reflection per se has an adaptive effect, which is canceled out by the maladaptive effect of self-rumination, because reflectors are likely to ruminate and reflect simultaneously.

Concentrations of bisphenol A in the composite food samples from the 2008 Canadian total diet study in Quebec City and dietary intake estimates

OpenAIRE

Cao, X.-L.; Perez-Locas, C.; Dufresne, G.; Clement, G.; Popovic, S.; Beraldin, F.; Dabeka, R.W.; Feeley, M.

2011-01-01

A total of 154 food composite samples from the 2008 total diet study in Quebec City were analysed for bisphenol A (BPA), and BPA was detected in less than half (36%, or 55 samples) of the samples tested. High concentrations of BPA were found mostly in the composite samples containing canned foods, with the highest BPA level being observed in canned fish (106 ng g−1), followed by canned corn (83.7 ng g−1), canned soups (22.2–44.4 ng g−1), canned baked beans (23.5 ng g−1), canned peas (16.8 ng ...

Identification of herbarium whole-leaf samples of Epilobium species by ATR-IR spectroscopy.

Science.gov (United States)

Strgulc Krajsek, Simona; Buh, Primoz; Zega, Anamarija; Kreft, Samo

2008-02-01

A simple, high-accuracy FT-IR method based on attenuated total reflection (ATR) was developed for the rapid determination of leaf samples of Epilobium species. The method is superior to other analytical techniques, since there is no need of laborious sample preparation such as grinding or extraction and solvent removal. A total of 70 herbarium specimens, belonging to all 13 Epilobium and to 2 Chamerion species growing in Slovenia, were analyzed. With the 100 most-informative wavenumbers in the range 700-1800 cm(-1), we obtained over 90% accuracy of species identification, with discriminant multivariate statistical analysis on the measurements made on whole dried leaves.

Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

International Nuclear Information System (INIS)

Brunet, Didier; Woignier, Thierry; Lesueur-Jannoyer, Magalie; Achard, Raphael; Rangon, Luc; Barthes, Bernard G.

2009-01-01

Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q 2 = 0.75, R 2 = 0.82 for the total set), especially for samples with chlordecone content -1 or when the sample set was rather homogeneous (Q 2 = 0.91, R 2 = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg -1 , nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. - Soil content in chlordecone, an organochlorine insecticide, can be determined time- and cost-effectively using near infrared reflectance spectroscopy (NIRS).

Determination of soil content in chlordecone (organochlorine pesticide) using near infrared reflectance spectroscopy (NIRS)

Energy Technology Data Exchange (ETDEWEB)

Brunet, Didier, E-mail: didier.brunet@ird.f [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France); Woignier, Thierry [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); CNRS - Centre National de la Recherche Scientifique, Universite Montpellier 2, place Eugene Bataillon, 34095 Montpellier Cedex 5 (France); Lesueur-Jannoyer, Magalie; Achard, Raphael [CIRAD (Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement), PRAM, BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Rangon, Luc [IRD, UMR Eco and Sols, PRAM (Pole de Recherche Agronomique de la Martinique), BP 213, Petit Morne, 97232 Le Lamentin, Martinique (French West Indies) (France); Barthes, Bernard G. [IRD - Institut de Recherche pour le Developpement, UMR Eco and Sols (Ecologie Fonctionnelle et Biogeochimie des Sols), Montpellier SupAgro, Batiment 12, 2 place Viala, 34060 Montpellier Cedex 1 (France)

2009-11-15

Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography-mass spectrometry could be correctly predicted by NIRS (Q{sup 2} = 0.75, R{sup 2} = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg{sup -1} or when the sample set was rather homogeneous (Q{sup 2} = 0.91, R{sup 2} = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg{sup -1}, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. - Soil content in chlordecone, an organochlorine insecticide, can be determined time- and cost-effectively using near infrared reflectance spectroscopy (NIRS).

Determination of total mercury for marine environmental monitoring studies by solid sampling continuum source high resolution atomic absorption spectrometry

Science.gov (United States)

Mandjukov, Petko; Orani, Anna Maria; Han, Eunmi; Vassileva, Emilia

2015-01-01

The most critical step in almost all commonly used analytical procedures for Hg determination is the sample preparation due to its extreme volatility. One of the possible solutions of this problem is the application of methods for direct analysis of solid samples. The possibilities for solid sampling high resolution continuum source atomic absorption spectrometry (HR CS AAS) determination of total mercury in various marine environmental samples e.g. sediments and biota are object of the present study. The instrumental parameters were optimized in order to obtain reproducible and interference free analytical signal. A calibration technique based on the use of solid standard certified reference materials similar to the nature of the analyzed sample was developed and applied to various CRMs and real samples. This technique allows simple and reliable evaluation of the uncertainty of the result and the metrological characteristics of the method. A validation approach in line with the requirements of ISO 17025 standard and Eurachem guidelines was followed. With this in mind, selectivity, working range (0.06 to 25 ng for biota and 0.025 to 4 ng for sediment samples, expressed as total Hg) linearity (confirmed by Student's t-test), bias (1.6-4.3%), repeatability (4-9%), reproducibility (9-11%), and absolute limit of detection (0.025 ng for sediment, 0.096 ng for marine biota) were systematically assessed using solid CRMs. The relative expanded uncertainty was estimated at 15% for sediment sample and 8.5% for marine biota sample (k = 2). Demonstration of traceability of measurement results is also presented. The potential of the proposed analytical procedure, based on solid sampling HR CS AAS technique was demonstrated by direct analysis of sea sediments form the Caribbean region and various CRMs. Overall, the use of solid sampling HR CS AAS permits obtaining significant advantages for the determination of this complex analyte in marine samples, such as straightforward

Algorithm for preparation of multilayer systems with high critical angle of total reflection

International Nuclear Information System (INIS)

Carron, I.; Ignatovich, V.

2002-01-01

The new development of theory of multilayer systems is presented. It shows precisely how to calculate thickness and number of layers to get reflectivity close to unity for a given, in principle, arbitrary critical angle. Application of the new approach to real systems is demonstrated

Direct determination of sorbitol and sodium glutamate by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) in the thermostabilizer employed in the production of yellow-fever vaccine.

Science.gov (United States)

de Castro, Eduardo da S G; Cassella, Ricardo J

2016-05-15

Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of the hydrogen content of oil samples from Nigeria using an Am-Be neutron source

International Nuclear Information System (INIS)

Jonah, S.A.; Elegba, S.B.; Zakari, I.I.

1998-01-01

A 5 Ci Am-Be neutron source-based facility, which utilises the principles of thermal neutron reflection technique in combination with foil activation method, has been used to determine the total hydrogen content of commercial oil samples from Nigeria. With an established detection limit of 0.25 H w% for oil matrix of volume 600-ml, the total hydrogen contents of the samples were found to be in the range of 11.11-14.22 H w%. The facility is economical and suitable for the determination of moisture in solid samples. A brief description of the ongoing projects and future plans concerning the CRP are enumerated. (author)

Sensitive Electrochemical Determination of Gallic Acid: Application in Estimation of Total Polyphenols in Plant Samples

Directory of Open Access Journals (Sweden)

Mohammad Ali Sheikh-Mohseni

2016-12-01

Full Text Available A modified electrode was prepared by modification of the carbon paste electrode (CPE with graphene nano-sheets. The fabricated modified electrode exhibited an electrocatalytic activity toward gallic acid (GA oxidation because of good conductivity, low electron transfer resistance and catalytic effect. The graphene modified CPE had a lower overvoltage and enhanced electrical current respect to the bare CPE for the oxidation of GA. The oxidation potential of GA decreased more than 210 mV by the modified electrode. The modified electrode responded to the GA in the concentration range of 3.0 × 10-5-1.5 × 10-4 M with high sensitivity by the technique of differential pulse voltammetry. Also, detection limit of 1.1 × 10-7 M was obtained by this modified electrode for GA. This electrode was used for the successful determination of GA in plant samples. Therefore, the content of total polyphenols in plant samples can be determined by the proposed modified electrode based on the concentration of GA in the sample.

Auto-calibrated scanning-angle prism-type total internal reflection microscopy for nanometer-precision axial position determination and optional variable-illumination-depth pseudo total internal reflection microscopy

Science.gov (United States)

Fang, Ning; Sun, Wei

2015-04-21

A method, apparatus, and system for improved VA-TIRFM microscopy. The method comprises automatically controlled calibration of one or more laser sources by precise control of presentation of each laser relative a sample for small incremental changes of incident angle over a range of critical TIR angles. The calibration then allows precise scanning of the sample for any of those calibrated angles for higher and more accurate resolution, and better reconstruction of the scans for super resolution reconstruction of the sample. Optionally the system can be controlled for incident angles of the excitation laser at sub-critical angles for pseudo TIRFM. Optionally both above-critical angle and sub critical angle measurements can be accomplished with the same system.

Reflection as a Learning Tool in Graduate Medical Education: A Systematic Review.

Science.gov (United States)

Winkel, Abigail Ford; Yingling, Sandra; Jones, Aubrie-Ann; Nicholson, Joey

2017-08-01

Graduate medical education programs employ reflection to advance a range of outcomes for physicians in training. However, the most effective applications of this tool have not been fully explored. A systematic review of the literature examined interventions reporting the use of reflection in graduate medical education. The authors searched Medline/PubMed, Embase, Cochrane CENTRAL, and ERIC for studies of reflection as a teaching tool to develop medical trainees' capacities. Key words and subject headings included reflection , narrative , residents/GME , and education / teaching / learning . No language or date limits were applied. The search yielded 1308 citations between inception for each database and June 15, 2015. A total of 16 studies, encompassing 477 residents and fellows, met eligibility criteria. Study quality was assessed using the Critical Appraisal Skills Programme Qualitative Checklist. The authors conducted a thematic analysis of the 16 articles. Outcomes studied encompassed the impact of reflection on empathy, comfort with learning in complex situations, and engagement in the learning process. Reflection increased learning of complex subjects and deepened professional values. It appears to be an effective tool for improving attitudes and comfort when exploring difficult material. Limitations include that most studies had small samples, used volunteers, and did not measure behavioral outcomes. Critical reflection is a tool that can amplify learning in residents and fellows. Added research is needed to understand how reflection can influence growth in professional capacities and patient-level outcomes in ways that can be measured.

The thermal history of the Bowen Basin: a comparison of apatite fission track analysis and vitrinite reflectance

International Nuclear Information System (INIS)

Marshallsea, S.J.

1987-01-01

Vitrinite reflectance and apatite fission-track analysis (AFTA) are two techiques widely used to assess paleotemperatures of the order of 20-120 deg.C. in sedimentary basins. Whereas vitrinite reflectance is essentially a qualitative technique that gives an integrated measure of the entire thermal history, AFTA can reveal information on the variation of paleotemperatures through time because fission-tracks in apatite are continually produced throughout geological time. An apatite fission track study of the Upper Permian units of the Bowen Basin has offered the opportunity to compare the two paleotemperature indicators and place constraints on the timing of maximum paleotemperatures. The regional pattern of apatite fission-track ages closely coincides with the vitrinite reflectance indicating that maximum paleotemperatures have varied across the Basin with the central region of the Bowen Basin experiencing highest paleotemperatures. The reduction in apatite reflectance fission-track age with increasing reflectance represents the progressive annealing at temperatures around 60-120 deg. C. of those fission-tracks formed prior to the time of maximum temperatures. In those samples giving the youngest apatite fission-track ages all tacks were totally annealed at this time, and the fission-track age in these samples, in the range 90-120 Myr, indicate the time of cooling from the thermal maximum in the Early Cretaceous. 1 ref